Auto merge of #2772 - RalfJung:rustup, r=RalfJung

Rustup

1501 files changed, 29958 insertions, 9789 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5f77656e5c1..552680f06f6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -418,14 +418,14 @@ jobs:
             os: windows-latest-xl
           - name: i686-mingw-1
             env:
-              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu"
               SCRIPT: make ci-mingw-subset-1
               NO_DOWNLOAD_CI_LLVM: 1
               CUSTOM_MINGW: 1
             os: windows-latest-xl
           - name: i686-mingw-2
             env:
-              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu"
               SCRIPT: make ci-mingw-subset-2
               NO_DOWNLOAD_CI_LLVM: 1
               CUSTOM_MINGW: 1
@@ -433,21 +433,21 @@ jobs:
           - name: x86_64-mingw-1
             env:
               SCRIPT: make ci-mingw-subset-1
-              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-profiler --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-profiler"
               NO_DOWNLOAD_CI_LLVM: 1
               CUSTOM_MINGW: 1
             os: windows-latest-xl
           - name: x86_64-mingw-2
             env:
               SCRIPT: make ci-mingw-subset-2
-              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-profiler --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-profiler"
               NO_DOWNLOAD_CI_LLVM: 1
               CUSTOM_MINGW: 1
             os: windows-latest-xl
           - name: dist-x86_64-msvc
             env:
               RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-msvc --host=x86_64-pc-windows-msvc --target=x86_64-pc-windows-msvc --enable-full-tools --enable-profiler --set rust.lto=thin"
-              SCRIPT: PGO_HOST=x86_64-pc-windows-msvc src/ci/pgo.sh python x.py dist bootstrap --include-default-paths
+              SCRIPT: PGO_HOST=x86_64-pc-windows-msvc python src/ci/stage-build.py python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             os: windows-latest-xl
           - name: dist-i686-msvc
@@ -465,7 +465,7 @@ jobs:
             os: windows-latest-xl
           - name: dist-i686-mingw
             env:
-              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu --enable-full-tools --enable-profiler --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=i686-pc-windows-gnu --enable-full-tools --enable-profiler"
               NO_DOWNLOAD_CI_LLVM: 1
               SCRIPT: python x.py dist bootstrap --include-default-paths
               CUSTOM_MINGW: 1
@@ -474,7 +474,7 @@ jobs:
           - name: dist-x86_64-mingw
             env:
               SCRIPT: python x.py dist bootstrap --include-default-paths
-              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-full-tools --enable-profiler --set llvm.allow-old-toolchain"
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-gnu --enable-full-tools --enable-profiler"
               NO_DOWNLOAD_CI_LLVM: 1
               CUSTOM_MINGW: 1
               DIST_REQUIRE_ALL_TOOLS: 1
diff --git a/Cargo.lock b/Cargo.lock
index 8e1a3c57f03..b35892ccd52 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -351,7 +351,7 @@ dependencies = [
  "cargo-test-macro",
  "cargo-test-support",
  "cargo-util",
- "clap 4.1.1",
+ "clap 4.1.4",
  "crates-io",
  "curl",
  "curl-sys",
@@ -655,9 +655,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.1.1"
+version = "4.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ec7a4128863c188deefe750ac1d1dfe66c236909f845af04beed823638dc1b2"
+checksum = "f13b9c79b5d1dd500d20ef541215a6423c75829ef43117e1b4d17fd8af0b5d76"
 dependencies = [
  "bitflags",
  "clap_derive 4.1.0",
@@ -675,7 +675,7 @@ version = "4.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "10861370d2ba66b0f5989f83ebf35db6421713fd92351790e7fdd6c36774c56b"
 dependencies = [
- "clap 4.1.1",
+ "clap 4.1.4",
 ]
 
 [[package]]
@@ -724,7 +724,7 @@ dependencies = [
 
 [[package]]
 name = "clippy"
-version = "0.1.68"
+version = "0.1.69"
 dependencies = [
  "clippy_lints",
  "clippy_utils",
@@ -766,7 +766,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_lints"
-version = "0.1.68"
+version = "0.1.69"
 dependencies = [
  "cargo_metadata 0.14.0",
  "clippy_utils",
@@ -789,7 +789,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_utils"
-version = "0.1.68"
+version = "0.1.69"
 dependencies = [
  "arrayvec",
  "if_chain",
@@ -1168,7 +1168,7 @@ checksum = "a0afaad2b26fa326569eb264b1363e8ae3357618c43982b3f285f0774ce76b69"
 
 [[package]]
 name = "declare_clippy_lint"
-version = "0.1.68"
+version = "0.1.69"
 dependencies = [
  "itertools",
  "quote",
@@ -1799,9 +1799,9 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.16.1"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ccf7f68c2995f392c49fffb4f95ae2c873297830eb25c6bc4c114ce8f4562acc"
+checksum = "be36bc9e0546df253c0cc41fd0af34f5e92845ad8509462ec76672fac6997f5b"
 dependencies = [
  "bitflags",
  "libc",
@@ -2294,7 +2294,7 @@ name = "jsondoclint"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "clap 4.1.1",
+ "clap 4.1.4",
  "fs-err",
  "rustdoc-json-types",
  "serde",
@@ -2365,9 +2365,9 @@ dependencies = [
 
 [[package]]
 name = "libgit2-sys"
-version = "0.14.2+1.5.1"
+version = "0.14.1+1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f3d95f6b51075fe9810a7ae22c7095f12b98005ab364d8544797a825ce946a4"
+checksum = "4a07fb2692bc3593bda59de45a502bb3071659f2c515e28c71e728306b038e17"
 dependencies = [
  "cc",
  "libc",
@@ -2557,7 +2557,7 @@ dependencies = [
  "ammonia",
  "anyhow",
  "chrono",
- "clap 4.1.1",
+ "clap 4.1.4",
  "clap_complete",
  "elasticlunr-rs",
  "env_logger 0.10.0",
@@ -3528,7 +3528,7 @@ dependencies = [
 name = "rustbook"
 version = "0.1.0"
 dependencies = [
- "clap 4.1.1",
+ "clap 4.1.4",
  "env_logger 0.7.1",
  "mdbook",
 ]
@@ -3672,6 +3672,7 @@ name = "rustc_ast"
 version = "0.0.0"
 dependencies = [
  "bitflags",
+ "memchr",
  "rustc_data_structures",
  "rustc_index",
  "rustc_lexer",
@@ -3729,6 +3730,7 @@ name = "rustc_ast_pretty"
 version = "0.0.0"
 dependencies = [
  "rustc_ast",
+ "rustc_parse_format",
  "rustc_span",
 ]
 
@@ -4926,7 +4928,7 @@ dependencies = [
 
 [[package]]
 name = "rustfmt-config_proc_macro"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4936,7 +4938,7 @@ dependencies = [
 
 [[package]]
 name = "rustfmt-nightly"
-version = "1.5.1"
+version = "1.5.2"
 dependencies = [
  "annotate-snippets",
  "anyhow",
@@ -5214,9 +5216,9 @@ checksum = "cc88c725d61fc6c3132893370cac4a0200e3fedf5da8331c570664b1987f5ca2"
 
 [[package]]
 name = "snap"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da73c8f77aebc0e40c300b93f0a5f1bece7a248a36eee287d4e095f35c7b7d6e"
+checksum = "5e9f0ab6ef7eb7353d9119c170a436d1bf248eea575ac42d19d12f4e34130831"
 
 [[package]]
 name = "snapbox"
diff --git a/RELEASES.md b/RELEASES.md
index 2901bfcc3e3..a63d4e8a043 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -1,3 +1,106 @@
+Version 1.67.0 (2023-01-26)
+==========================
+
+<a id="1.67.0-Language"></a>
+
+Language
+--------
+
+- [Make `Sized` predicates coinductive, allowing cycles.](https://github.com/rust-lang/rust/pull/100386/)
+- [`#[must_use]` annotations on `async fn` also affect the `Future::Output`.](https://github.com/rust-lang/rust/pull/100633/)
+- [Elaborate supertrait obligations when deducing closure signatures.](https://github.com/rust-lang/rust/pull/101834/)
+- [Invalid literals are no longer an error under `cfg(FALSE)`.](https://github.com/rust-lang/rust/pull/102944/)
+- [Unreserve braced enum variants in value namespace.](https://github.com/rust-lang/rust/pull/103578/)
+
+<a id="1.67.0-Compiler"></a>
+
+Compiler
+--------
+
+- [Enable varargs support for calling conventions other than `C` or `cdecl`.](https://github.com/rust-lang/rust/pull/97971/)
+- [Add new MIR constant propagation based on dataflow analysis.](https://github.com/rust-lang/rust/pull/101168/)
+- [Optimize field ordering by grouping m\*2^n-sized fields with equivalently aligned ones.](https://github.com/rust-lang/rust/pull/102750/)
+- [Stabilize native library modifier `verbatim`.](https://github.com/rust-lang/rust/pull/104360/)
+
+Added and removed targets:
+
+- [Add a tier 3 target for PowerPC on AIX](https://github.com/rust-lang/rust/pull/102293/), `powerpc64-ibm-aix`.
+- [Add a tier 3 target for the Sony PlayStation 1](https://github.com/rust-lang/rust/pull/102689/), `mipsel-sony-psx`.
+- [Add tier 3 `no_std` targets for the QNX Neutrino RTOS](https://github.com/rust-lang/rust/pull/102701/),
+  `aarch64-unknown-nto-qnx710` and `x86_64-pc-nto-qnx710`.
+- [Remove tier 3 `linuxkernel` targets](https://github.com/rust-lang/rust/pull/104015/) (not used by the actual kernel).
+
+Refer to Rust's [platform support page][platform-support-doc]
+for more information on Rust's tiered platform support.
+
+<a id="1.67.0-Libraries"></a>
+
+Libraries
+---------
+
+- [Merge `crossbeam-channel` into `std::sync::mpsc`.](https://github.com/rust-lang/rust/pull/93563/)
+- [Fix inconsistent rounding of 0.5 when formatted to 0 decimal places.](https://github.com/rust-lang/rust/pull/102935/)
+- [Derive `Eq` and `Hash` for `ControlFlow`.](https://github.com/rust-lang/rust/pull/103084/)
+- [Don't build `compiler_builtins` with `-C panic=abort`.](https://github.com/rust-lang/rust/pull/103786/)
+
+<a id="1.67.0-Stabilized-APIs"></a>
+
+Stabilized APIs
+---------------
+
+- [`{integer}::checked_ilog`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog)
+- [`{integer}::checked_ilog2`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog2)
+- [`{integer}::checked_ilog10`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog10)
+- [`{integer}::ilog`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog)
+- [`{integer}::ilog2`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog2)
+- [`{integer}::ilog10`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog10)
+- [`NonZeroU*::ilog2`](https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#method.ilog2)
+- [`NonZeroU*::ilog10`](https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#method.ilog10)
+- [`NonZero*::BITS`](https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#associatedconstant.BITS)
+
+These APIs are now stable in const contexts:
+
+- [`char::from_u32`](https://doc.rust-lang.org/stable/std/primitive.char.html#method.from_u32)
+- [`char::from_digit`](https://doc.rust-lang.org/stable/std/primitive.char.html#method.from_digit)
+- [`char::to_digit`](https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_digit)
+- [`core::char::from_u32`](https://doc.rust-lang.org/stable/core/char/fn.from_u32.html)
+- [`core::char::from_digit`](https://doc.rust-lang.org/stable/core/char/fn.from_digit.html)
+
+<a id="1.67.0-Compatibility-Notes"></a>
+
+Compatibility Notes
+-------------------
+
+- [The layout of `repr(Rust)` types now groups m\*2^n-sized fields with
+  equivalently aligned ones.](https://github.com/rust-lang/rust/pull/102750/)
+  This is intended to be an optimization, but it is also known to increase type
+  sizes in a few cases for the placement of enum tags. As a reminder, the layout
+  of `repr(Rust)` types is an implementation detail, subject to change.
+- [0.5 now rounds to 0 when formatted to 0 decimal places.](https://github.com/rust-lang/rust/pull/102935/)
+  This makes it consistent with the rest of floating point formatting that
+  rounds ties toward even digits.
+- [Chains of `&&` and `||` will now drop temporaries from their sub-expressions in
+  evaluation order, left-to-right.](https://github.com/rust-lang/rust/pull/103293/)
+  Previously, it was "twisted" such that the _first_ expression dropped its
+  temporaries _last_, after all of the other expressions dropped in order.
+- [Underscore suffixes on string literals are now a hard error.](https://github.com/rust-lang/rust/pull/103914/)
+  This has been a future-compatibility warning since 1.20.0.
+- [Stop passing `-export-dynamic` to `wasm-ld`.](https://github.com/rust-lang/rust/pull/105405/)
+- [`main` is now mangled as `__main_void` on `wasm32-wasi`.](https://github.com/rust-lang/rust/pull/105468/)
+- [Cargo now emits an error if there are multiple registries in the configuration
+  with the same index URL.](https://github.com/rust-lang/cargo/pull/10592)
+
+<a id="1.67.0-Internal-Changes"></a>
+
+Internal Changes
+----------------
+
+These changes do not affect any public interfaces of Rust, but they represent
+significant improvements to the performance or internals of rustc and related
+tools.
+
+- [Rewrite LLVM's archive writer in Rust.](https://github.com/rust-lang/rust/pull/97485/)
+
 Version 1.66.1 (2023-01-10)
 ===========================
 
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index f4cb459f32f..fe65ad9c6cb 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -267,6 +267,9 @@ impl TargetDataLayout {
                 ["a", ref a @ ..] => dl.aggregate_align = align(a, "a")?,
                 ["f32", ref a @ ..] => dl.f32_align = align(a, "f32")?,
                 ["f64", ref a @ ..] => dl.f64_align = align(a, "f64")?,
+                // FIXME(erikdesjardins): we should be parsing nonzero address spaces
+                // this will require replacing TargetDataLayout::{pointer_size,pointer_align}
+                // with e.g. `fn pointer_size_in(AddressSpace)`
                 [p @ "p", s, ref a @ ..] | [p @ "p0", s, ref a @ ..] => {
                     dl.pointer_size = size(s, p)?;
                     dl.pointer_align = align(a, p)?;
@@ -861,7 +864,7 @@ pub enum Primitive {
     Int(Integer, bool),
     F32,
     F64,
-    Pointer,
+    Pointer(AddressSpace),
 }
 
 impl Primitive {
@@ -872,7 +875,10 @@ impl Primitive {
             Int(i, _) => i.size(),
             F32 => Size::from_bits(32),
             F64 => Size::from_bits(64),
-            Pointer => dl.pointer_size,
+            // FIXME(erikdesjardins): ignoring address space is technically wrong, pointers in
+            // different address spaces can have different sizes
+            // (but TargetDataLayout doesn't currently parse that part of the DL string)
+            Pointer(_) => dl.pointer_size,
         }
     }
 
@@ -883,26 +889,12 @@ impl Primitive {
             Int(i, _) => i.align(dl),
             F32 => dl.f32_align,
             F64 => dl.f64_align,
-            Pointer => dl.pointer_align,
+            // FIXME(erikdesjardins): ignoring address space is technically wrong, pointers in
+            // different address spaces can have different alignments
+            // (but TargetDataLayout doesn't currently parse that part of the DL string)
+            Pointer(_) => dl.pointer_align,
         }
     }
-
-    // FIXME(eddyb) remove, it's trivial thanks to `matches!`.
-    #[inline]
-    pub fn is_float(self) -> bool {
-        matches!(self, F32 | F64)
-    }
-
-    // FIXME(eddyb) remove, it's completely unused.
-    #[inline]
-    pub fn is_int(self) -> bool {
-        matches!(self, Int(..))
-    }
-
-    #[inline]
-    pub fn is_ptr(self) -> bool {
-        matches!(self, Pointer)
-    }
 }
 
 /// Inclusive wrap-around range of valid values, that is, if
@@ -1188,7 +1180,8 @@ impl FieldsShape {
 /// An identifier that specifies the address space that some operation
 /// should operate on. Special address spaces have an effect on code generation,
 /// depending on the target and the address spaces it implements.
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
 pub struct AddressSpace(pub u32);
 
 impl AddressSpace {
@@ -1468,7 +1461,6 @@ pub struct PointeeInfo {
     pub size: Size,
     pub align: Align,
     pub safe: Option<PointerKind>,
-    pub address_space: AddressSpace,
 }
 
 /// Used in `might_permit_raw_init` to indicate the kind of initialisation
diff --git a/compiler/rustc_ast/Cargo.toml b/compiler/rustc_ast/Cargo.toml
index 9253b7e6891..10d7fa1db60 100644
--- a/compiler/rustc_ast/Cargo.toml
+++ b/compiler/rustc_ast/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 bitflags = "1.2.1"
+memchr = "2.5.0"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_index = { path = "../rustc_index" }
 rustc_lexer = { path = "../rustc_lexer" }
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 9317579f70d..8ad3270c510 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -18,6 +18,7 @@
 //! - [`Attribute`]: Metadata associated with item.
 //! - [`UnOp`], [`BinOp`], and [`BinOpKind`]: Unary and binary operators.
 
+pub use crate::format::*;
 pub use crate::util::parser::ExprPrecedence;
 pub use GenericArgs::*;
 pub use UnsafeSource::*;
@@ -1269,6 +1270,7 @@ impl Expr {
             ExprKind::Try(..) => ExprPrecedence::Try,
             ExprKind::Yield(..) => ExprPrecedence::Yield,
             ExprKind::Yeet(..) => ExprPrecedence::Yeet,
+            ExprKind::FormatArgs(..) => ExprPrecedence::FormatArgs,
             ExprKind::Err => ExprPrecedence::Err,
         }
     }
@@ -1499,6 +1501,9 @@ pub enum ExprKind {
     /// with a `ByteStr` literal.
     IncludedBytes(Lrc<[u8]>),
 
+    /// A `format_args!()` expression.
+    FormatArgs(P<FormatArgs>),
+
     /// Placeholder for an expression that wasn't syntactically well formed in some way.
     Err,
 }
diff --git a/compiler/rustc_builtin_macros/src/format/ast.rs b/compiler/rustc_ast/src/format.rs
index 01dbffa21b8..d021bea5eca 100644
--- a/compiler/rustc_builtin_macros/src/format/ast.rs
+++ b/compiler/rustc_ast/src/format.rs
@@ -1,5 +1,5 @@
-use rustc_ast::ptr::P;
-use rustc_ast::Expr;
+use crate::ptr::P;
+use crate::Expr;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::Span;
@@ -39,7 +39,7 @@ use rustc_span::Span;
 /// Basically the "AST" for a complete `format_args!()`.
 ///
 /// E.g., `format_args!("hello {name}");`.
-#[derive(Clone, Debug)]
+#[derive(Clone, Encodable, Decodable, Debug)]
 pub struct FormatArgs {
     pub span: Span,
     pub template: Vec<FormatArgsPiece>,
@@ -49,7 +49,7 @@ pub struct FormatArgs {
 /// A piece of a format template string.
 ///
 /// E.g. "hello" or "{name}".
-#[derive(Clone, Debug)]
+#[derive(Clone, Encodable, Decodable, Debug)]
 pub enum FormatArgsPiece {
     Literal(Symbol),
     Placeholder(FormatPlaceholder),
@@ -59,7 +59,7 @@ pub enum FormatArgsPiece {
 ///
 /// E.g. `1, 2, name="ferris", n=3`,
 /// but also implicit captured arguments like `x` in `format_args!("{x}")`.
-#[derive(Clone, Debug)]
+#[derive(Clone, Encodable, Decodable, Debug)]
 pub struct FormatArguments {
     arguments: Vec<FormatArgument>,
     num_unnamed_args: usize,
@@ -67,6 +67,12 @@ pub struct FormatArguments {
     names: FxHashMap<Symbol, usize>,
 }
 
+// FIXME: Rustdoc has trouble proving Send/Sync for this. See #106930.
+#[cfg(parallel_compiler)]
+unsafe impl Sync for FormatArguments {}
+#[cfg(parallel_compiler)]
+unsafe impl Send for FormatArguments {}
+
 impl FormatArguments {
     pub fn new() -> Self {
         Self {
@@ -121,18 +127,22 @@ impl FormatArguments {
         &self.arguments[..self.num_explicit_args]
     }
 
-    pub fn into_vec(self) -> Vec<FormatArgument> {
-        self.arguments
+    pub fn all_args(&self) -> &[FormatArgument] {
+        &self.arguments[..]
+    }
+
+    pub fn all_args_mut(&mut self) -> &mut [FormatArgument] {
+        &mut self.arguments[..]
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Encodable, Decodable, Debug)]
 pub struct FormatArgument {
     pub kind: FormatArgumentKind,
     pub expr: P<Expr>,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Encodable, Decodable, Debug)]
 pub enum FormatArgumentKind {
     /// `format_args(…, arg)`
     Normal,
@@ -152,7 +162,7 @@ impl FormatArgumentKind {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
 pub struct FormatPlaceholder {
     /// Index into [`FormatArgs::arguments`].
     pub argument: FormatArgPosition,
@@ -164,7 +174,7 @@ pub struct FormatPlaceholder {
     pub format_options: FormatOptions,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
 pub struct FormatArgPosition {
     /// Which argument this position refers to (Ok),
     /// or would've referred to if it existed (Err).
@@ -175,7 +185,7 @@ pub struct FormatArgPosition {
     pub span: Option<Span>,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
 pub enum FormatArgPositionKind {
     /// `{}` or `{:.*}`
     Implicit,
@@ -185,7 +195,7 @@ pub enum FormatArgPositionKind {
     Named,
 }
 
-#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
+#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq, Hash)]
 pub enum FormatTrait {
     /// `{}`
     Display,
@@ -207,7 +217,7 @@ pub enum FormatTrait {
     UpperHex,
 }
 
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
+#[derive(Clone, Encodable, Decodable, Default, Debug, PartialEq, Eq)]
 pub struct FormatOptions {
     /// The width. E.g. `{:5}` or `{:width$}`.
     pub width: Option<FormatCount>,
@@ -217,11 +227,33 @@ pub struct FormatOptions {
     pub alignment: Option<FormatAlignment>,
     /// The fill character. E.g. the `.` in `{:.>10}`.
     pub fill: Option<char>,
-    /// The `+`, `-`, `0`, `#`, `x?` and `X?` flags.
-    pub flags: u32,
+    /// The `+` or `-` flag.
+    pub sign: Option<FormatSign>,
+    /// The `#` flag.
+    pub alternate: bool,
+    /// The `0` flag. E.g. the `0` in `{:02x}`.
+    pub zero_pad: bool,
+    /// The `x` or `X` flag (for `Debug` only). E.g. the `x` in `{:x?}`.
+    pub debug_hex: Option<FormatDebugHex>,
+}
+
+#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
+pub enum FormatSign {
+    /// The `+` flag.
+    Plus,
+    /// The `-` flag.
+    Minus,
+}
+
+#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
+pub enum FormatDebugHex {
+    /// The `x` flag in `{:x?}`.
+    Lower,
+    /// The `X` flag in `{:X?}`.
+    Upper,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
 pub enum FormatAlignment {
     /// `{:<}`
     Left,
@@ -231,7 +263,7 @@ pub enum FormatAlignment {
     Center,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq)]
 pub enum FormatCount {
     /// `{:5}` or `{:.5}`
     Literal(usize),
diff --git a/compiler/rustc_ast/src/lib.rs b/compiler/rustc_ast/src/lib.rs
index 9c1dfeb1a61..23c32fa96ca 100644
--- a/compiler/rustc_ast/src/lib.rs
+++ b/compiler/rustc_ast/src/lib.rs
@@ -16,7 +16,6 @@
 #![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(negative_impls)]
-#![feature(slice_internals)]
 #![feature(stmt_expr_attributes)]
 #![recursion_limit = "256"]
 #![deny(rustc::untranslatable_diagnostic)]
@@ -42,6 +41,7 @@ pub mod ast_traits;
 pub mod attr;
 pub mod entry;
 pub mod expand;
+pub mod format;
 pub mod mut_visit;
 pub mod node_id;
 pub mod ptr;
@@ -51,6 +51,7 @@ pub mod visit;
 
 pub use self::ast::*;
 pub use self::ast_traits::{AstDeref, AstNodeWrapper, HasAttrs, HasNodeId, HasSpan, HasTokens};
+pub use self::format::*;
 
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 
diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index 77f342d1eb3..1dd62626b8f 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -297,6 +297,10 @@ pub trait MutVisitor: Sized {
     fn visit_inline_asm_sym(&mut self, sym: &mut InlineAsmSym) {
         noop_visit_inline_asm_sym(sym, self)
     }
+
+    fn visit_format_args(&mut self, fmt: &mut FormatArgs) {
+        noop_visit_format_args(fmt, self)
+    }
 }
 
 /// Use a map-style function (`FnOnce(T) -> T`) to overwrite a `&mut T`. Useful
@@ -1284,6 +1288,15 @@ pub fn noop_visit_inline_asm_sym<T: MutVisitor>(
     vis.visit_path(path);
 }
 
+pub fn noop_visit_format_args<T: MutVisitor>(fmt: &mut FormatArgs, vis: &mut T) {
+    for arg in fmt.arguments.all_args_mut() {
+        if let FormatArgumentKind::Named(name) = &mut arg.kind {
+            vis.visit_ident(name);
+        }
+        vis.visit_expr(&mut arg.expr);
+    }
+}
+
 pub fn noop_visit_expr<T: MutVisitor>(
     Expr { kind, id, span, attrs, tokens }: &mut Expr,
     vis: &mut T,
@@ -1425,6 +1438,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
             visit_opt(expr, |expr| vis.visit_expr(expr));
         }
         ExprKind::InlineAsm(asm) => vis.visit_inline_asm(asm),
+        ExprKind::FormatArgs(fmt) => vis.visit_format_args(fmt),
         ExprKind::MacCall(mac) => vis.visit_mac_call(mac),
         ExprKind::Struct(se) => {
             let StructExpr { qself, path, fields, rest } = se.deref_mut();
diff --git a/compiler/rustc_ast/src/util/parser.rs b/compiler/rustc_ast/src/util/parser.rs
index 4f7099c7be8..81efdaa44b3 100644
--- a/compiler/rustc_ast/src/util/parser.rs
+++ b/compiler/rustc_ast/src/util/parser.rs
@@ -271,6 +271,7 @@ pub enum ExprPrecedence {
     Try,
     InlineAsm,
     Mac,
+    FormatArgs,
 
     Array,
     Repeat,
@@ -335,7 +336,8 @@ impl ExprPrecedence {
             | ExprPrecedence::Index
             | ExprPrecedence::Try
             | ExprPrecedence::InlineAsm
-            | ExprPrecedence::Mac => PREC_POSTFIX,
+            | ExprPrecedence::Mac
+            | ExprPrecedence::FormatArgs => PREC_POSTFIX,
 
             // Never need parens
             ExprPrecedence::Array
diff --git a/compiler/rustc_ast/src/util/unicode.rs b/compiler/rustc_ast/src/util/unicode.rs
index 0eae791b25e..6f57d66b227 100644
--- a/compiler/rustc_ast/src/util/unicode.rs
+++ b/compiler/rustc_ast/src/util/unicode.rs
@@ -17,7 +17,7 @@ pub fn contains_text_flow_control_chars(s: &str) -> bool {
     // U+2069 - E2 81 A9
     let mut bytes = s.as_bytes();
     loop {
-        match core::slice::memchr::memchr(0xE2, bytes) {
+        match memchr::memchr(0xE2, bytes) {
             Some(idx) => {
                 // bytes are valid UTF-8 -> E2 must be followed by two bytes
                 let ch = &bytes[idx..idx + 3];
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index e8823eff83a..e7b2e4b1cb4 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -242,6 +242,9 @@ pub trait Visitor<'ast>: Sized {
     fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) {
         walk_inline_asm(self, asm)
     }
+    fn visit_format_args(&mut self, fmt: &'ast FormatArgs) {
+        walk_format_args(self, fmt)
+    }
     fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) {
         walk_inline_asm_sym(self, sym)
     }
@@ -400,8 +403,8 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
             walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Ref);
             visitor.visit_ty(&mutable_type.ty)
         }
-        TyKind::Tup(tuple_element_types) => {
-            walk_list!(visitor, visit_ty, tuple_element_types);
+        TyKind::Tup(tys) => {
+            walk_list!(visitor, visit_ty, tys);
         }
         TyKind::BareFn(function_declaration) => {
             walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
@@ -756,6 +759,15 @@ pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(visitor: &mut V, sym: &'a InlineA
     visitor.visit_path(&sym.path, sym.id);
 }
 
+pub fn walk_format_args<'a, V: Visitor<'a>>(visitor: &mut V, fmt: &'a FormatArgs) {
+    for arg in fmt.arguments.all_args() {
+        if let FormatArgumentKind::Named(name) = arg.kind {
+            visitor.visit_ident(name);
+        }
+        visitor.visit_expr(&arg.expr);
+    }
+}
+
 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
     walk_list!(visitor, visit_attribute, expression.attrs.iter());
 
@@ -896,6 +908,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
         ExprKind::MacCall(mac) => visitor.visit_mac_call(mac),
         ExprKind::Paren(subexpression) => visitor.visit_expr(subexpression),
         ExprKind::InlineAsm(asm) => visitor.visit_inline_asm(asm),
+        ExprKind::FormatArgs(f) => visitor.visit_format_args(f),
         ExprKind::Yield(optional_expression) => {
             walk_list!(visitor, visit_expr, optional_expression);
         }
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index c3611b2f522..cc523fe7d08 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -16,7 +16,7 @@ use rustc_hir::def::Res;
 use rustc_hir::definitions::DefPathData;
 use rustc_session::errors::report_lit_error;
 use rustc_span::source_map::{respan, DesugaringKind, Span, Spanned};
-use rustc_span::symbol::{sym, Ident};
+use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::DUMMY_SP;
 use thin_vec::thin_vec;
 
@@ -294,6 +294,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 ExprKind::InlineAsm(asm) => {
                     hir::ExprKind::InlineAsm(self.lower_inline_asm(e.span, asm))
                 }
+                ExprKind::FormatArgs(fmt) => self.lower_format_args(e.span, fmt),
                 ExprKind::Struct(se) => {
                     let rest = match &se.rest {
                         StructRest::Base(e) => Some(self.lower_expr(e)),
@@ -1735,7 +1736,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.expr(span, hir::ExprKind::DropTemps(expr))
     }
 
-    fn expr_match(
+    pub(super) fn expr_match(
         &mut self,
         span: Span,
         arg: &'hir hir::Expr<'hir>,
@@ -1763,7 +1764,44 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.arena.alloc(self.expr(sp, hir::ExprKind::Tup(&[])))
     }
 
-    fn expr_call_mut(
+    pub(super) fn expr_usize(&mut self, sp: Span, value: usize) -> hir::Expr<'hir> {
+        self.expr(
+            sp,
+            hir::ExprKind::Lit(hir::Lit {
+                span: sp,
+                node: ast::LitKind::Int(
+                    value as u128,
+                    ast::LitIntType::Unsigned(ast::UintTy::Usize),
+                ),
+            }),
+        )
+    }
+
+    pub(super) fn expr_u32(&mut self, sp: Span, value: u32) -> hir::Expr<'hir> {
+        self.expr(
+            sp,
+            hir::ExprKind::Lit(hir::Lit {
+                span: sp,
+                node: ast::LitKind::Int(value.into(), ast::LitIntType::Unsigned(ast::UintTy::U32)),
+            }),
+        )
+    }
+
+    pub(super) fn expr_char(&mut self, sp: Span, value: char) -> hir::Expr<'hir> {
+        self.expr(sp, hir::ExprKind::Lit(hir::Lit { span: sp, node: ast::LitKind::Char(value) }))
+    }
+
+    pub(super) fn expr_str(&mut self, sp: Span, value: Symbol) -> hir::Expr<'hir> {
+        self.expr(
+            sp,
+            hir::ExprKind::Lit(hir::Lit {
+                span: sp,
+                node: ast::LitKind::Str(value, ast::StrStyle::Cooked),
+            }),
+        )
+    }
+
+    pub(super) fn expr_call_mut(
         &mut self,
         span: Span,
         e: &'hir hir::Expr<'hir>,
@@ -1772,7 +1810,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.expr(span, hir::ExprKind::Call(e, args))
     }
 
-    fn expr_call(
+    pub(super) fn expr_call(
         &mut self,
         span: Span,
         e: &'hir hir::Expr<'hir>,
@@ -1814,6 +1852,27 @@ impl<'hir> LoweringContext<'_, 'hir> {
         )
     }
 
+    /// `<LangItem>::name`
+    pub(super) fn expr_lang_item_type_relative(
+        &mut self,
+        span: Span,
+        lang_item: hir::LangItem,
+        name: Symbol,
+    ) -> hir::Expr<'hir> {
+        let path = hir::ExprKind::Path(hir::QPath::TypeRelative(
+            self.arena.alloc(self.ty(
+                span,
+                hir::TyKind::Path(hir::QPath::LangItem(lang_item, self.lower_span(span), None)),
+            )),
+            self.arena.alloc(hir::PathSegment::new(
+                Ident::new(name, span),
+                self.next_id(),
+                Res::Err,
+            )),
+        ));
+        self.expr(span, path)
+    }
+
     pub(super) fn expr_ident(
         &mut self,
         sp: Span,
@@ -1872,12 +1931,25 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.expr(b.span, hir::ExprKind::Block(b, None))
     }
 
+    pub(super) fn expr_array_ref(
+        &mut self,
+        span: Span,
+        elements: &'hir [hir::Expr<'hir>],
+    ) -> hir::Expr<'hir> {
+        let addrof = hir::ExprKind::AddrOf(
+            hir::BorrowKind::Ref,
+            hir::Mutability::Not,
+            self.arena.alloc(self.expr(span, hir::ExprKind::Array(elements))),
+        );
+        self.expr(span, addrof)
+    }
+
     pub(super) fn expr(&mut self, span: Span, kind: hir::ExprKind<'hir>) -> hir::Expr<'hir> {
         let hir_id = self.next_id();
         hir::Expr { hir_id, kind, span: self.lower_span(span) }
     }
 
-    fn expr_field(
+    pub(super) fn expr_field(
         &mut self,
         ident: Ident,
         expr: &'hir hir::Expr<'hir>,
@@ -1892,7 +1964,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    fn arm(&mut self, pat: &'hir hir::Pat<'hir>, expr: &'hir hir::Expr<'hir>) -> hir::Arm<'hir> {
+    pub(super) fn arm(
+        &mut self,
+        pat: &'hir hir::Pat<'hir>,
+        expr: &'hir hir::Expr<'hir>,
+    ) -> hir::Arm<'hir> {
         hir::Arm {
             hir_id: self.next_id(),
             pat,
diff --git a/compiler/rustc_ast_lowering/src/format.rs b/compiler/rustc_ast_lowering/src/format.rs
new file mode 100644
index 00000000000..e7dd0b18a03
--- /dev/null
+++ b/compiler/rustc_ast_lowering/src/format.rs
@@ -0,0 +1,398 @@
+use super::LoweringContext;
+use rustc_ast as ast;
+use rustc_ast::visit::{self, Visitor};
+use rustc_ast::*;
+use rustc_data_structures::fx::FxIndexSet;
+use rustc_hir as hir;
+use rustc_span::{
+    sym,
+    symbol::{kw, Ident},
+    Span,
+};
+
+impl<'hir> LoweringContext<'_, 'hir> {
+    pub(crate) fn lower_format_args(&mut self, sp: Span, fmt: &FormatArgs) -> hir::ExprKind<'hir> {
+        expand_format_args(self, sp, fmt)
+    }
+}
+
+#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
+enum ArgumentType {
+    Format(FormatTrait),
+    Usize,
+}
+
+/// Generate a hir expression representing an argument to a format_args invocation.
+///
+/// Generates:
+///
+/// ```text
+///     <core::fmt::ArgumentV1>::new_…(arg)
+/// ```
+fn make_argument<'hir>(
+    ctx: &mut LoweringContext<'_, 'hir>,
+    sp: Span,
+    arg: &'hir hir::Expr<'hir>,
+    ty: ArgumentType,
+) -> hir::Expr<'hir> {
+    use ArgumentType::*;
+    use FormatTrait::*;
+    let new_fn = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+        sp,
+        hir::LangItem::FormatArgument,
+        match ty {
+            Format(Display) => sym::new_display,
+            Format(Debug) => sym::new_debug,
+            Format(LowerExp) => sym::new_lower_exp,
+            Format(UpperExp) => sym::new_upper_exp,
+            Format(Octal) => sym::new_octal,
+            Format(Pointer) => sym::new_pointer,
+            Format(Binary) => sym::new_binary,
+            Format(LowerHex) => sym::new_lower_hex,
+            Format(UpperHex) => sym::new_upper_hex,
+            Usize => sym::from_usize,
+        },
+    ));
+    ctx.expr_call_mut(sp, new_fn, std::slice::from_ref(arg))
+}
+
+/// Generate a hir expression for a format_args Count.
+///
+/// Generates:
+///
+/// ```text
+///     <core::fmt::rt::v1::Count>::Is(…)
+/// ```
+///
+/// or
+///
+/// ```text
+///     <core::fmt::rt::v1::Count>::Param(…)
+/// ```
+///
+/// or
+///
+/// ```text
+///     <core::fmt::rt::v1::Count>::Implied
+/// ```
+fn make_count<'hir>(
+    ctx: &mut LoweringContext<'_, 'hir>,
+    sp: Span,
+    count: &Option<FormatCount>,
+    argmap: &mut FxIndexSet<(usize, ArgumentType)>,
+) -> hir::Expr<'hir> {
+    match count {
+        Some(FormatCount::Literal(n)) => {
+            let count_is = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+                sp,
+                hir::LangItem::FormatCount,
+                sym::Is,
+            ));
+            let value = ctx.arena.alloc_from_iter([ctx.expr_usize(sp, *n)]);
+            ctx.expr_call_mut(sp, count_is, value)
+        }
+        Some(FormatCount::Argument(arg)) => {
+            if let Ok(arg_index) = arg.index {
+                let (i, _) = argmap.insert_full((arg_index, ArgumentType::Usize));
+                let count_param = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+                    sp,
+                    hir::LangItem::FormatCount,
+                    sym::Param,
+                ));
+                let value = ctx.arena.alloc_from_iter([ctx.expr_usize(sp, i)]);
+                ctx.expr_call_mut(sp, count_param, value)
+            } else {
+                ctx.expr(sp, hir::ExprKind::Err)
+            }
+        }
+        None => ctx.expr_lang_item_type_relative(sp, hir::LangItem::FormatCount, sym::Implied),
+    }
+}
+
+/// Generate a hir expression for a format_args placeholder specification.
+///
+/// Generates
+///
+/// ```text
+///     <core::fmt::rt::v1::Argument::new(
+///         …usize, // position
+///         '…', // fill
+///         <core::fmt::rt::v1::Alignment>::…, // alignment
+///         …u32, // flags
+///         <core::fmt::rt::v1::Count::…>, // width
+///         <core::fmt::rt::v1::Count::…>, // precision
+///     )
+/// ```
+fn make_format_spec<'hir>(
+    ctx: &mut LoweringContext<'_, 'hir>,
+    sp: Span,
+    placeholder: &FormatPlaceholder,
+    argmap: &mut FxIndexSet<(usize, ArgumentType)>,
+) -> hir::Expr<'hir> {
+    let position = match placeholder.argument.index {
+        Ok(arg_index) => {
+            let (i, _) =
+                argmap.insert_full((arg_index, ArgumentType::Format(placeholder.format_trait)));
+            ctx.expr_usize(sp, i)
+        }
+        Err(_) => ctx.expr(sp, hir::ExprKind::Err),
+    };
+    let &FormatOptions {
+        ref width,
+        ref precision,
+        alignment,
+        fill,
+        sign,
+        alternate,
+        zero_pad,
+        debug_hex,
+    } = &placeholder.format_options;
+    let fill = ctx.expr_char(sp, fill.unwrap_or(' '));
+    let align = ctx.expr_lang_item_type_relative(
+        sp,
+        hir::LangItem::FormatAlignment,
+        match alignment {
+            Some(FormatAlignment::Left) => sym::Left,
+            Some(FormatAlignment::Right) => sym::Right,
+            Some(FormatAlignment::Center) => sym::Center,
+            None => sym::Unknown,
+        },
+    );
+    // This needs to match `FlagV1` in library/core/src/fmt/mod.rs.
+    let flags: u32 = ((sign == Some(FormatSign::Plus)) as u32)
+        | ((sign == Some(FormatSign::Minus)) as u32) << 1
+        | (alternate as u32) << 2
+        | (zero_pad as u32) << 3
+        | ((debug_hex == Some(FormatDebugHex::Lower)) as u32) << 4
+        | ((debug_hex == Some(FormatDebugHex::Upper)) as u32) << 5;
+    let flags = ctx.expr_u32(sp, flags);
+    let precision = make_count(ctx, sp, &precision, argmap);
+    let width = make_count(ctx, sp, &width, argmap);
+    let format_placeholder_new = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+        sp,
+        hir::LangItem::FormatPlaceholder,
+        sym::new,
+    ));
+    let args = ctx.arena.alloc_from_iter([position, fill, align, flags, precision, width]);
+    ctx.expr_call_mut(sp, format_placeholder_new, args)
+}
+
+fn expand_format_args<'hir>(
+    ctx: &mut LoweringContext<'_, 'hir>,
+    macsp: Span,
+    fmt: &FormatArgs,
+) -> hir::ExprKind<'hir> {
+    let lit_pieces =
+        ctx.arena.alloc_from_iter(fmt.template.iter().enumerate().filter_map(|(i, piece)| {
+            match piece {
+                &FormatArgsPiece::Literal(s) => Some(ctx.expr_str(fmt.span, s)),
+                &FormatArgsPiece::Placeholder(_) => {
+                    // Inject empty string before placeholders when not already preceded by a literal piece.
+                    if i == 0 || matches!(fmt.template[i - 1], FormatArgsPiece::Placeholder(_)) {
+                        Some(ctx.expr_str(fmt.span, kw::Empty))
+                    } else {
+                        None
+                    }
+                }
+            }
+        }));
+    let lit_pieces = ctx.expr_array_ref(fmt.span, lit_pieces);
+
+    // Whether we'll use the `Arguments::new_v1_formatted` form (true),
+    // or the `Arguments::new_v1` form (false).
+    let mut use_format_options = false;
+
+    // Create a list of all _unique_ (argument, format trait) combinations.
+    // E.g. "{0} {0:x} {0} {1}" -> [(0, Display), (0, LowerHex), (1, Display)]
+    let mut argmap = FxIndexSet::default();
+    for piece in &fmt.template {
+        let FormatArgsPiece::Placeholder(placeholder) = piece else { continue };
+        if placeholder.format_options != Default::default() {
+            // Can't use basic form if there's any formatting options.
+            use_format_options = true;
+        }
+        if let Ok(index) = placeholder.argument.index {
+            if !argmap.insert((index, ArgumentType::Format(placeholder.format_trait))) {
+                // Duplicate (argument, format trait) combination,
+                // which we'll only put once in the args array.
+                use_format_options = true;
+            }
+        }
+    }
+
+    let format_options = use_format_options.then(|| {
+        // Generate:
+        //     &[format_spec_0, format_spec_1, format_spec_2]
+        let elements: Vec<_> = fmt
+            .template
+            .iter()
+            .filter_map(|piece| {
+                let FormatArgsPiece::Placeholder(placeholder) = piece else { return None };
+                Some(make_format_spec(ctx, macsp, placeholder, &mut argmap))
+            })
+            .collect();
+        ctx.expr_array_ref(macsp, ctx.arena.alloc_from_iter(elements))
+    });
+
+    let arguments = fmt.arguments.all_args();
+
+    // If the args array contains exactly all the original arguments once,
+    // in order, we can use a simple array instead of a `match` construction.
+    // However, if there's a yield point in any argument except the first one,
+    // we don't do this, because an ArgumentV1 cannot be kept across yield points.
+    //
+    // This is an optimization, speeding up compilation about 1-2% in some cases.
+    // See https://github.com/rust-lang/rust/pull/106770#issuecomment-1380790609
+    let use_simple_array = argmap.len() == arguments.len()
+        && argmap.iter().enumerate().all(|(i, &(j, _))| i == j)
+        && arguments.iter().skip(1).all(|arg| !may_contain_yield_point(&arg.expr));
+
+    let args = if use_simple_array {
+        // Generate:
+        //     &[
+        //         <core::fmt::ArgumentV1>::new_display(&arg0),
+        //         <core::fmt::ArgumentV1>::new_lower_hex(&arg1),
+        //         <core::fmt::ArgumentV1>::new_debug(&arg2),
+        //         …
+        //     ]
+        let elements: Vec<_> = arguments
+            .iter()
+            .zip(argmap)
+            .map(|(arg, (_, ty))| {
+                let sp = arg.expr.span.with_ctxt(macsp.ctxt());
+                let arg = ctx.lower_expr(&arg.expr);
+                let ref_arg = ctx.arena.alloc(ctx.expr(
+                    sp,
+                    hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, arg),
+                ));
+                make_argument(ctx, sp, ref_arg, ty)
+            })
+            .collect();
+        ctx.expr_array_ref(macsp, ctx.arena.alloc_from_iter(elements))
+    } else {
+        // Generate:
+        //     &match (&arg0, &arg1, &…) {
+        //         args => [
+        //             <core::fmt::ArgumentV1>::new_display(args.0),
+        //             <core::fmt::ArgumentV1>::new_lower_hex(args.1),
+        //             <core::fmt::ArgumentV1>::new_debug(args.0),
+        //             …
+        //         ]
+        //     }
+        let args_ident = Ident::new(sym::args, macsp);
+        let (args_pat, args_hir_id) = ctx.pat_ident(macsp, args_ident);
+        let args = ctx.arena.alloc_from_iter(argmap.iter().map(|&(arg_index, ty)| {
+            if let Some(arg) = arguments.get(arg_index) {
+                let sp = arg.expr.span.with_ctxt(macsp.ctxt());
+                let args_ident_expr = ctx.expr_ident(macsp, args_ident, args_hir_id);
+                let arg = ctx.arena.alloc(ctx.expr(
+                    sp,
+                    hir::ExprKind::Field(
+                        args_ident_expr,
+                        Ident::new(sym::integer(arg_index), macsp),
+                    ),
+                ));
+                make_argument(ctx, sp, arg, ty)
+            } else {
+                ctx.expr(macsp, hir::ExprKind::Err)
+            }
+        }));
+        let elements: Vec<_> = arguments
+            .iter()
+            .map(|arg| {
+                let arg_expr = ctx.lower_expr(&arg.expr);
+                ctx.expr(
+                    arg.expr.span.with_ctxt(macsp.ctxt()),
+                    hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, arg_expr),
+                )
+            })
+            .collect();
+        let args_tuple = ctx
+            .arena
+            .alloc(ctx.expr(macsp, hir::ExprKind::Tup(ctx.arena.alloc_from_iter(elements))));
+        let array = ctx.arena.alloc(ctx.expr(macsp, hir::ExprKind::Array(args)));
+        let match_arms = ctx.arena.alloc_from_iter([ctx.arm(args_pat, array)]);
+        let match_expr = ctx.arena.alloc(ctx.expr_match(
+            macsp,
+            args_tuple,
+            match_arms,
+            hir::MatchSource::FormatArgs,
+        ));
+        ctx.expr(
+            macsp,
+            hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, match_expr),
+        )
+    };
+
+    if let Some(format_options) = format_options {
+        // Generate:
+        //     <core::fmt::Arguments>::new_v1_formatted(
+        //         lit_pieces,
+        //         args,
+        //         format_options,
+        //         unsafe { ::core::fmt::UnsafeArg::new() }
+        //     )
+        let new_v1_formatted = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+            macsp,
+            hir::LangItem::FormatArguments,
+            sym::new_v1_formatted,
+        ));
+        let unsafe_arg_new = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+            macsp,
+            hir::LangItem::FormatUnsafeArg,
+            sym::new,
+        ));
+        let unsafe_arg_new_call = ctx.expr_call(macsp, unsafe_arg_new, &[]);
+        let hir_id = ctx.next_id();
+        let unsafe_arg = ctx.expr_block(ctx.arena.alloc(hir::Block {
+            stmts: &[],
+            expr: Some(unsafe_arg_new_call),
+            hir_id,
+            rules: hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::CompilerGenerated),
+            span: macsp,
+            targeted_by_break: false,
+        }));
+        let args = ctx.arena.alloc_from_iter([lit_pieces, args, format_options, unsafe_arg]);
+        hir::ExprKind::Call(new_v1_formatted, args)
+    } else {
+        // Generate:
+        //     <core::fmt::Arguments>::new_v1(
+        //         lit_pieces,
+        //         args,
+        //     )
+        let new_v1 = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
+            macsp,
+            hir::LangItem::FormatArguments,
+            sym::new_v1,
+        ));
+        let new_args = ctx.arena.alloc_from_iter([lit_pieces, args]);
+        hir::ExprKind::Call(new_v1, new_args)
+    }
+}
+
+fn may_contain_yield_point(e: &ast::Expr) -> bool {
+    struct MayContainYieldPoint(bool);
+
+    impl Visitor<'_> for MayContainYieldPoint {
+        fn visit_expr(&mut self, e: &ast::Expr) {
+            if let ast::ExprKind::Await(_) | ast::ExprKind::Yield(_) = e.kind {
+                self.0 = true;
+            } else {
+                visit::walk_expr(self, e);
+            }
+        }
+
+        fn visit_mac_call(&mut self, _: &ast::MacCall) {
+            // Macros should be expanded at this point.
+            unreachable!("unexpanded macro in ast lowering");
+        }
+
+        fn visit_item(&mut self, _: &ast::Item) {
+            // Do not recurse into nested items.
+        }
+    }
+
+    let mut visitor = MayContainYieldPoint(false);
+    visitor.visit_expr(e);
+    visitor.0
+}
diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index 63033085bec..f7fe0d771a1 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -275,19 +275,6 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
-    fn visit_fn(
-        &mut self,
-        fk: intravisit::FnKind<'hir>,
-        fd: &'hir FnDecl<'hir>,
-        b: BodyId,
-        _: Span,
-        id: HirId,
-    ) {
-        assert_eq!(self.owner, id.owner);
-        assert_eq!(self.parent_node, id.local_id);
-        intravisit::walk_fn(self, fk, fd, b, id);
-    }
-
     fn visit_block(&mut self, block: &'hir Block<'hir>) {
         self.insert(block.span, block.hir_id, Node::Block(block));
         self.with_parent(block.hir_id, |this| {
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index 5d2589cb2b2..2865082bd7a 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -67,7 +67,6 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
             current_hir_id_owner: hir::CRATE_OWNER_ID,
             item_local_id_counter: hir::ItemLocalId::new(0),
             node_id_to_local_id: Default::default(),
-            local_id_to_def_id: SortedMap::new(),
             trait_map: Default::default(),
 
             // Lowering state.
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index bc6d2cf12c7..a04a2595293 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -80,6 +80,7 @@ mod asm;
 mod block;
 mod errors;
 mod expr;
+mod format;
 mod index;
 mod item;
 mod lifetime_collector;
@@ -118,7 +119,6 @@ struct LoweringContext<'a, 'hir> {
 
     current_hir_id_owner: hir::OwnerId,
     item_local_id_counter: hir::ItemLocalId,
-    local_id_to_def_id: SortedMap<ItemLocalId, LocalDefId>,
     trait_map: FxHashMap<ItemLocalId, Box<[TraitCandidate]>>,
 
     impl_trait_defs: Vec<hir::GenericParam<'hir>>,
@@ -416,6 +416,7 @@ fn compute_hir_hash(
 
 pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
     let sess = tcx.sess;
+    tcx.ensure().output_filenames(());
     let (mut resolver, krate) = tcx.resolver_for_lowering(()).steal();
 
     let ast_index = index_crate(&resolver.node_id_to_def_id, &krate);
@@ -565,7 +566,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let current_attrs = std::mem::take(&mut self.attrs);
         let current_bodies = std::mem::take(&mut self.bodies);
         let current_node_ids = std::mem::take(&mut self.node_id_to_local_id);
-        let current_id_to_def_id = std::mem::take(&mut self.local_id_to_def_id);
         let current_trait_map = std::mem::take(&mut self.trait_map);
         let current_owner =
             std::mem::replace(&mut self.current_hir_id_owner, hir::OwnerId { def_id });
@@ -592,7 +592,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.attrs = current_attrs;
         self.bodies = current_bodies;
         self.node_id_to_local_id = current_node_ids;
-        self.local_id_to_def_id = current_id_to_def_id;
         self.trait_map = current_trait_map;
         self.current_hir_id_owner = current_owner;
         self.item_local_id_counter = current_local_counter;
@@ -627,7 +626,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn make_owner_info(&mut self, node: hir::OwnerNode<'hir>) -> &'hir hir::OwnerInfo<'hir> {
         let attrs = std::mem::take(&mut self.attrs);
         let mut bodies = std::mem::take(&mut self.bodies);
-        let local_id_to_def_id = std::mem::take(&mut self.local_id_to_def_id);
         let trait_map = std::mem::take(&mut self.trait_map);
 
         #[cfg(debug_assertions)]
@@ -643,13 +641,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let (hash_including_bodies, hash_without_bodies) = self.hash_owner(node, &bodies);
         let (nodes, parenting) =
             index::index_hir(self.tcx.sess, &*self.tcx.definitions_untracked(), node, &bodies);
-        let nodes = hir::OwnerNodes {
-            hash_including_bodies,
-            hash_without_bodies,
-            nodes,
-            bodies,
-            local_id_to_def_id,
-        };
+        let nodes = hir::OwnerNodes { hash_including_bodies, hash_without_bodies, nodes, bodies };
         let attrs = {
             let hash = self.tcx.with_stable_hashing_context(|mut hcx| {
                 let mut stable_hasher = StableHasher::new();
@@ -708,7 +700,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 assert_ne!(local_id, hir::ItemLocalId::new(0));
                 if let Some(def_id) = self.opt_local_def_id(ast_node_id) {
                     self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id)));
-                    self.local_id_to_def_id.insert(local_id, def_id);
                 }
 
                 if let Some(traits) = self.resolver.trait_map.remove(&ast_node_id) {
diff --git a/compiler/rustc_ast_pretty/Cargo.toml b/compiler/rustc_ast_pretty/Cargo.toml
index a3e3e823b08..b4900dc39a8 100644
--- a/compiler/rustc_ast_pretty/Cargo.toml
+++ b/compiler/rustc_ast_pretty/Cargo.toml
@@ -6,5 +6,6 @@ edition = "2021"
 [lib]
 
 [dependencies]
-rustc_span = { path = "../rustc_span" }
 rustc_ast = { path = "../rustc_ast" }
+rustc_parse_format = { path = "../rustc_parse_format" }
+rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
index 2a18e5164a3..cacfe9eb2f1 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
@@ -6,6 +6,11 @@ use rustc_ast::token;
 use rustc_ast::util::literal::escape_byte_str_symbol;
 use rustc_ast::util::parser::{self, AssocOp, Fixity};
 use rustc_ast::{self as ast, BlockCheckMode};
+use rustc_ast::{
+    FormatAlignment, FormatArgPosition, FormatArgsPiece, FormatCount, FormatDebugHex, FormatSign,
+    FormatTrait,
+};
+use std::fmt::Write;
 
 impl<'a> State<'a> {
     fn print_else(&mut self, els: Option<&ast::Expr>) {
@@ -527,9 +532,23 @@ impl<'a> State<'a> {
                 }
             }
             ast::ExprKind::InlineAsm(a) => {
+                // FIXME: This should have its own syntax, distinct from a macro invocation.
                 self.word("asm!");
                 self.print_inline_asm(a);
             }
+            ast::ExprKind::FormatArgs(fmt) => {
+                // FIXME: This should have its own syntax, distinct from a macro invocation.
+                self.word("format_args!");
+                self.popen();
+                self.rbox(0, Inconsistent);
+                self.word(reconstruct_format_args_template_string(&fmt.template));
+                for arg in fmt.arguments.all_args() {
+                    self.word_space(",");
+                    self.print_expr(&arg.expr);
+                }
+                self.end();
+                self.pclose();
+            }
             ast::ExprKind::MacCall(m) => self.print_mac(m),
             ast::ExprKind::Paren(e) => {
                 self.popen();
@@ -629,3 +648,88 @@ impl<'a> State<'a> {
         }
     }
 }
+
+pub fn reconstruct_format_args_template_string(pieces: &[FormatArgsPiece]) -> String {
+    let mut template = "\"".to_string();
+    for piece in pieces {
+        match piece {
+            FormatArgsPiece::Literal(s) => {
+                for c in s.as_str().escape_debug() {
+                    template.push(c);
+                    if let '{' | '}' = c {
+                        template.push(c);
+                    }
+                }
+            }
+            FormatArgsPiece::Placeholder(p) => {
+                template.push('{');
+                let (Ok(n) | Err(n)) = p.argument.index;
+                write!(template, "{n}").unwrap();
+                if p.format_options != Default::default() || p.format_trait != FormatTrait::Display
+                {
+                    template.push_str(":");
+                }
+                if let Some(fill) = p.format_options.fill {
+                    template.push(fill);
+                }
+                match p.format_options.alignment {
+                    Some(FormatAlignment::Left) => template.push_str("<"),
+                    Some(FormatAlignment::Right) => template.push_str(">"),
+                    Some(FormatAlignment::Center) => template.push_str("^"),
+                    None => {}
+                }
+                match p.format_options.sign {
+                    Some(FormatSign::Plus) => template.push('+'),
+                    Some(FormatSign::Minus) => template.push('-'),
+                    None => {}
+                }
+                if p.format_options.alternate {
+                    template.push('#');
+                }
+                if p.format_options.zero_pad {
+                    template.push('0');
+                }
+                if let Some(width) = &p.format_options.width {
+                    match width {
+                        FormatCount::Literal(n) => write!(template, "{n}").unwrap(),
+                        FormatCount::Argument(FormatArgPosition {
+                            index: Ok(n) | Err(n), ..
+                        }) => {
+                            write!(template, "{n}$").unwrap();
+                        }
+                    }
+                }
+                if let Some(precision) = &p.format_options.precision {
+                    template.push('.');
+                    match precision {
+                        FormatCount::Literal(n) => write!(template, "{n}").unwrap(),
+                        FormatCount::Argument(FormatArgPosition {
+                            index: Ok(n) | Err(n), ..
+                        }) => {
+                            write!(template, "{n}$").unwrap();
+                        }
+                    }
+                }
+                match p.format_options.debug_hex {
+                    Some(FormatDebugHex::Lower) => template.push('x'),
+                    Some(FormatDebugHex::Upper) => template.push('X'),
+                    None => {}
+                }
+                template.push_str(match p.format_trait {
+                    FormatTrait::Display => "",
+                    FormatTrait::Debug => "?",
+                    FormatTrait::LowerExp => "e",
+                    FormatTrait::UpperExp => "E",
+                    FormatTrait::Octal => "o",
+                    FormatTrait::Pointer => "p",
+                    FormatTrait::Binary => "b",
+                    FormatTrait::LowerHex => "x",
+                    FormatTrait::UpperHex => "X",
+                });
+                template.push('}');
+            }
+        }
+    }
+    template.push('"');
+    template
+}
diff --git a/compiler/rustc_borrowck/src/borrowck_errors.rs b/compiler/rustc_borrowck/src/borrowck_errors.rs
index a4943d11204..2bbb9618dbf 100644
--- a/compiler/rustc_borrowck/src/borrowck_errors.rs
+++ b/compiler/rustc_borrowck/src/borrowck_errors.rs
@@ -37,7 +37,7 @@ impl<'cx, 'tcx> crate::MirBorrowckCtxt<'cx, 'tcx> {
             desc,
         );
 
-        err.span_label(borrow_span, format!("borrow of {} occurs here", borrow_desc));
+        err.span_label(borrow_span, format!("{} is borrowed here", borrow_desc));
         err.span_label(span, format!("use of borrowed {}", borrow_desc));
         err
     }
@@ -250,8 +250,8 @@ impl<'cx, 'tcx> crate::MirBorrowckCtxt<'cx, 'tcx> {
             desc,
         );
 
-        err.span_label(borrow_span, format!("borrow of {} occurs here", desc));
-        err.span_label(span, format!("assignment to borrowed {} occurs here", desc));
+        err.span_label(borrow_span, format!("{} is borrowed here", desc));
+        err.span_label(span, format!("{} is assigned to here but it was already borrowed", desc));
         err
     }
 
diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs
index 8c4885770ad..2821677c537 100644
--- a/compiler/rustc_borrowck/src/dataflow.rs
+++ b/compiler/rustc_borrowck/src/dataflow.rs
@@ -393,6 +393,7 @@ impl<'tcx> rustc_mir_dataflow::GenKillAnalysis<'tcx> for Borrows<'_, 'tcx> {
             | mir::StatementKind::AscribeUserType(..)
             | mir::StatementKind::Coverage(..)
             | mir::StatementKind::Intrinsic(..)
+            | mir::StatementKind::ConstEvalCounter
             | mir::StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index e5a36259fa4..50c0faf4597 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -766,7 +766,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let copy_did = infcx.tcx.require_lang_item(LangItem::Copy, Some(span));
         let cause = ObligationCause::new(
             span,
-            self.mir_hir_id(),
+            self.mir_def_id(),
             rustc_infer::traits::ObligationCauseCode::MiscObligation,
         );
         let errors = rustc_trait_selection::traits::fully_solve_bound(
@@ -1736,7 +1736,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 &self.local_names,
                 &mut err,
                 "",
-                None,
+                Some(borrow_span),
                 None,
             );
         }
@@ -2599,7 +2599,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 match ty.kind() {
                     ty::FnDef(_, _) | ty::FnPtr(_) => self.annotate_fn_sig(
                         self.mir_def_id(),
-                        self.infcx.tcx.fn_sig(self.mir_def_id()),
+                        self.infcx.tcx.fn_sig(self.mir_def_id()).subst_identity(),
                     ),
                     _ => None,
                 }
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index 2095747097b..19855075ced 100644
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@@ -1,6 +1,8 @@
 //! Print diagnostics to explain why values are borrowed.
 
 use rustc_errors::{Applicability, Diagnostic};
+use rustc_hir as hir;
+use rustc_hir::intravisit::Visitor;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::NllRegionVariableOrigin;
 use rustc_middle::mir::{
@@ -11,6 +13,7 @@ use rustc_middle::ty::adjustment::PointerCast;
 use rustc_middle::ty::{self, RegionVid, TyCtxt};
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{sym, DesugaringKind, Span};
+use rustc_trait_selection::traits::error_reporting::FindExprBySpan;
 
 use crate::region_infer::{BlameConstraint, ExtraConstraintInfo};
 use crate::{
@@ -63,6 +66,36 @@ impl<'tcx> BorrowExplanation<'tcx> {
         borrow_span: Option<Span>,
         multiple_borrow_span: Option<(Span, Span)>,
     ) {
+        if let Some(span) = borrow_span {
+            let def_id = body.source.def_id();
+            if let Some(node) = tcx.hir().get_if_local(def_id)
+                && let Some(body_id) = node.body_id()
+            {
+                let body = tcx.hir().body(body_id);
+                let mut expr_finder = FindExprBySpan::new(span);
+                expr_finder.visit_expr(body.value);
+                if let Some(mut expr) = expr_finder.result {
+                    while let hir::ExprKind::AddrOf(_, _, inner)
+                        | hir::ExprKind::Unary(hir::UnOp::Deref, inner)
+                        | hir::ExprKind::Field(inner, _)
+                        | hir::ExprKind::MethodCall(_, inner, _, _)
+                        | hir::ExprKind::Index(inner, _) = &expr.kind
+                    {
+                        expr = inner;
+                    }
+                    if let hir::ExprKind::Path(hir::QPath::Resolved(None, p)) = expr.kind
+                        && let [hir::PathSegment { ident, args: None, .. }] = p.segments
+                        && let hir::def::Res::Local(hir_id) = p.res
+                        && let Some(hir::Node::Pat(pat)) = tcx.hir().find(hir_id)
+                    {
+                        err.span_label(
+                            pat.span,
+                            &format!("binding `{ident}` declared here"),
+                        );
+                    }
+                }
+            }
+        }
         match *self {
             BorrowExplanation::UsedLater(later_use_kind, var_or_use_span, path_span) => {
                 let message = match later_use_kind {
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index 1b40b7143cb..8c579bac7e8 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -1064,7 +1064,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         );
                     }
                 }
-                CallKind::Normal { self_arg, desugaring, method_did } => {
+                CallKind::Normal { self_arg, desugaring, method_did, method_substs } => {
                     let self_arg = self_arg.unwrap();
                     let tcx = self.infcx.tcx;
                     if let Some((CallDesugaringKind::ForLoopIntoIter, _)) = desugaring {
@@ -1128,15 +1128,19 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                 "{place_name} {partially_str}moved due to this method call{loop_message}",
                             ),
                         );
+
                         let infcx = tcx.infer_ctxt().build();
+                        // Erase and shadow everything that could be passed to the new infcx.
                         let ty = tcx.erase_regions(moved_place.ty(self.body, tcx).ty);
+                        let method_substs = tcx.erase_regions(method_substs);
+
                         if let ty::Adt(def, substs) = ty.kind()
                             && Some(def.did()) == tcx.lang_items().pin_type()
                             && let ty::Ref(_, _, hir::Mutability::Mut) = substs.type_at(0).kind()
                             && let self_ty = infcx.replace_bound_vars_with_fresh_vars(
                                 fn_call_span,
                                 LateBoundRegionConversionTime::FnCall,
-                                tcx.fn_sig(method_did).input(0),
+                                tcx.fn_sig(method_did).subst(tcx, method_substs).input(0),
                             )
                             && infcx.can_eq(self.param_env, ty, self_ty).is_ok()
                         {
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
index 6db3c858ae7..ea58ad5ae3e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -448,7 +448,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 };
                 self.note_type_does_not_implement_copy(err, &place_desc, place_ty, Some(span), "");
 
-                use_spans.args_span_label(err, format!("move out of {place_desc} occurs here"));
+                use_spans.args_span_label(err, format!("{place_desc} is moved here"));
             }
         }
     }
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 187861ba127..87db08ef5b5 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -813,17 +813,10 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             if *outlived_f != ty::ReStatic {
                 return;
             }
+            let suitable_region = self.infcx.tcx.is_suitable_region(f);
+            let Some(suitable_region) = suitable_region else { return; };
 
-            let fn_returns = self
-                .infcx
-                .tcx
-                .is_suitable_region(f)
-                .map(|r| self.infcx.tcx.return_type_impl_or_dyn_traits(r.def_id))
-                .unwrap_or_default();
-
-            if fn_returns.is_empty() {
-                return;
-            }
+            let fn_returns = self.infcx.tcx.return_type_impl_or_dyn_traits(suitable_region.def_id);
 
             let param = if let Some(param) = find_param_with_region(self.infcx.tcx, f, outlived_f) {
                 param
@@ -839,15 +832,43 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             };
             let captures = format!("captures data from {arg}");
 
-            return nice_region_error::suggest_new_region_bound(
-                self.infcx.tcx,
-                diag,
-                fn_returns,
-                lifetime.to_string(),
-                Some(arg),
-                captures,
-                Some((param.param_ty_span, param.param_ty.to_string())),
-                self.infcx.tcx.is_suitable_region(f).map(|r| r.def_id),
+            if !fn_returns.is_empty() {
+                nice_region_error::suggest_new_region_bound(
+                    self.infcx.tcx,
+                    diag,
+                    fn_returns,
+                    lifetime.to_string(),
+                    Some(arg),
+                    captures,
+                    Some((param.param_ty_span, param.param_ty.to_string())),
+                    Some(suitable_region.def_id),
+                );
+                return;
+            }
+
+            let Some((alias_tys, alias_span)) = self
+                .infcx
+                .tcx
+                .return_type_impl_or_dyn_traits_with_type_alias(suitable_region.def_id) else { return; };
+
+            // in case the return type of the method is a type alias
+            let mut spans_suggs: Vec<_> = Vec::new();
+            for alias_ty in alias_tys {
+                if alias_ty.span.desugaring_kind().is_some() {
+                    // Skip `async` desugaring `impl Future`.
+                    ()
+                }
+                if let TyKind::TraitObject(_, lt, _) = alias_ty.kind {
+                    spans_suggs.push((lt.ident.span.shrink_to_hi(), " + 'a".to_string()));
+                }
+            }
+            spans_suggs.push((alias_span.shrink_to_hi(), "<'a>".to_string()));
+            diag.multipart_suggestion_verbose(
+                &format!(
+                    "to declare that the trait object {captures}, you can add a lifetime parameter `'a` in the type alias"
+                ),
+                spans_suggs,
+                Applicability::MaybeIncorrect,
             );
         }
     }
diff --git a/compiler/rustc_borrowck/src/invalidation.rs b/compiler/rustc_borrowck/src/invalidation.rs
index 6fd9290058c..6217676d5c1 100644
--- a/compiler/rustc_borrowck/src/invalidation.rs
+++ b/compiler/rustc_borrowck/src/invalidation.rs
@@ -91,7 +91,8 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                     LocalMutationIsAllowed::Yes,
                 );
             }
-            StatementKind::Nop
+            StatementKind::ConstEvalCounter
+            | StatementKind::Nop
             | StatementKind::Retag { .. }
             | StatementKind::Deinit(..)
             | StatementKind::SetDiscriminant { .. } => {
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 73ea7314b75..bc81abe4005 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -609,7 +609,8 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
             StatementKind::AscribeUserType(..)
             // Doesn't have any language semantics
             | StatementKind::Coverage(..)
-            // Does not actually affect borrowck
+            // These do not actually affect borrowck
+            | StatementKind::ConstEvalCounter
             | StatementKind::StorageLive(..) => {}
             StatementKind::StorageDead(local) => {
                 self.access_place(
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index 238172ea399..2ae13990a45 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -7,7 +7,6 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::graph::scc::Sccs;
 use rustc_errors::Diagnostic;
 use rustc_hir::def_id::CRATE_DEF_ID;
-use rustc_hir::CRATE_HIR_ID;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::outlives::test_type_match;
 use rustc_infer::infer::region_constraints::{GenericKind, VarInfos, VerifyBound, VerifyIfEq};
@@ -2022,7 +2021,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             .map(|constraint| BlameConstraint {
                 category: constraint.category,
                 from_closure: constraint.from_closure,
-                cause: ObligationCause::new(constraint.span, CRATE_HIR_ID, cause_code.clone()),
+                cause: ObligationCause::new(constraint.span, CRATE_DEF_ID, cause_code.clone()),
                 variance_info: constraint.variance_info,
                 outlives_constraint: *constraint,
             })
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index db5a67a8b44..e0e814cfc0a 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -273,7 +273,6 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         // This logic duplicates most of `check_opaque_meets_bounds`.
         // FIXME(oli-obk): Also do region checks here and then consider removing `check_opaque_meets_bounds` entirely.
         let param_env = self.tcx.param_env(def_id);
-        let body_id = self.tcx.local_def_id_to_hir_id(def_id);
         // HACK This bubble is required for this tests to pass:
         // type-alias-impl-trait/issue-67844-nested-opaque.rs
         let infcx =
@@ -290,7 +289,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         // the bounds that the function supplies.
         let opaque_ty = self.tcx.mk_opaque(def_id.to_def_id(), id_substs);
         if let Err(err) = ocx.eq(
-            &ObligationCause::misc(instantiated_ty.span, body_id),
+            &ObligationCause::misc(instantiated_ty.span, def_id),
             param_env,
             opaque_ty,
             definition_ty,
@@ -298,7 +297,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
             infcx
                 .err_ctxt()
                 .report_mismatched_types(
-                    &ObligationCause::misc(instantiated_ty.span, body_id),
+                    &ObligationCause::misc(instantiated_ty.span, def_id),
                     opaque_ty,
                     definition_ty,
                     err,
@@ -309,7 +308,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         ocx.register_obligation(Obligation::misc(
             infcx.tcx,
             instantiated_ty.span,
-            body_id,
+            def_id,
             param_env,
             predicate,
         ));
@@ -368,18 +367,6 @@ fn check_opaque_type_parameter_valid(
     for (i, arg) in opaque_type_key.substs.iter().enumerate() {
         let arg_is_param = match arg.unpack() {
             GenericArgKind::Type(ty) => matches!(ty.kind(), ty::Param(_)),
-            GenericArgKind::Lifetime(lt) if lt.is_static() => {
-                tcx.sess
-                    .struct_span_err(span, "non-defining opaque type use in defining scope")
-                    .span_label(
-                        tcx.def_span(opaque_generics.param_at(i, tcx).def_id),
-                        "cannot use static lifetime; use a bound lifetime \
-                                    instead or remove the lifetime parameter from the \
-                                    opaque type",
-                    )
-                    .emit();
-                return false;
-            }
             GenericArgKind::Lifetime(lt) => {
                 matches!(*lt, ty::ReEarlyBound(_) | ty::ReFree(_))
             }
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 81bd4c2a783..06087b0c579 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -1258,6 +1258,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             | StatementKind::StorageDead(..)
             | StatementKind::Retag { .. }
             | StatementKind::Coverage(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
             StatementKind::Deinit(..) | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 8bff66f8d5c..5380913f5c8 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -472,7 +472,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         // C-variadic fns also have a `VaList` input that's not listed in the signature
         // (as it's created inside the body itself, not passed in from outside).
         if let DefiningTy::FnDef(def_id, _) = defining_ty {
-            if self.infcx.tcx.fn_sig(def_id).c_variadic() {
+            if self.infcx.tcx.fn_sig(def_id).skip_binder().c_variadic() {
                 let va_list_did = self.infcx.tcx.require_lang_item(
                     LangItem::VaList,
                     Some(self.infcx.tcx.def_span(self.mir_def.did)),
@@ -665,7 +665,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             }
 
             DefiningTy::FnDef(def_id, _) => {
-                let sig = tcx.fn_sig(def_id);
+                let sig = tcx.fn_sig(def_id).subst_identity();
                 let sig = indices.fold_to_region_vids(tcx, sig);
                 sig.inputs_and_output()
             }
diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index 93b07801e03..342b1735661 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -297,6 +297,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
             | ExprKind::Continue(_)
             | ExprKind::Err
             | ExprKind::Field(_, _)
+            | ExprKind::FormatArgs(_)
             | ExprKind::ForLoop(_, _, _, _)
             | ExprKind::If(_, _, _)
             | ExprKind::IncludedBytes(..)
diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
index 240167146e1..0481a118906 100644
--- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs
@@ -17,6 +17,7 @@ pub fn expand_deriving_copy(
         span,
         path: path_std!(marker::Copy),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: false,
         additional_bounds: Vec::new(),
         supports_unions: true,
         methods: Vec::new(),
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index ef5a75f428d..42f50d8ade2 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -73,6 +73,7 @@ pub fn expand_deriving_clone(
         span,
         path: path_std!(clone::Clone),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: bounds,
         supports_unions: true,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
index 3e994f037ad..424719f9795 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
@@ -27,6 +27,7 @@ pub fn expand_deriving_eq(
         span,
         path: path_std!(cmp::Eq),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: true,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
index a926fca4e65..671f32550d2 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
@@ -20,6 +20,7 @@ pub fn expand_deriving_ord(
         span,
         path: path_std!(cmp::Ord),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
index 9051fe0b28a..88d454fbc11 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
@@ -84,6 +84,7 @@ pub fn expand_deriving_partial_eq(
         span,
         path: path_std!(cmp::PartialEq),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods,
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
index c9dc8921262..bcc90442eb7 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
@@ -1,7 +1,7 @@
 use crate::deriving::generic::ty::*;
 use crate::deriving::generic::*;
 use crate::deriving::{path_std, pathvec_std};
-use rustc_ast::MetaItem;
+use rustc_ast::{ExprKind, ItemKind, MetaItem, PatKind};
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
@@ -21,6 +21,27 @@ pub fn expand_deriving_partial_ord(
 
     let attrs = thin_vec![cx.attr_word(sym::inline, span)];
 
+    // Order in which to perform matching
+    let tag_then_data = if let Annotatable::Item(item) = item
+        && let ItemKind::Enum(def, _) = &item.kind {
+            let dataful: Vec<bool> = def.variants.iter().map(|v| !v.data.fields().is_empty()).collect();
+            match dataful.iter().filter(|&&b| b).count() {
+                // No data, placing the tag check first makes codegen simpler
+                0 => true,
+                1..=2 => false,
+                _ => {
+                    (0..dataful.len()-1).any(|i| {
+                        if dataful[i] && let Some(idx) = dataful[i+1..].iter().position(|v| *v) {
+                            idx >= 2
+                        } else {
+                            false
+                        }
+                    })
+                }
+            }
+        } else {
+            true
+        };
     let partial_cmp_def = MethodDef {
         name: sym::partial_cmp,
         generics: Bounds::empty(),
@@ -30,7 +51,7 @@ pub fn expand_deriving_partial_ord(
         attributes: attrs,
         fieldless_variants_strategy: FieldlessVariantsStrategy::Unify,
         combine_substructure: combine_substructure(Box::new(|cx, span, substr| {
-            cs_partial_cmp(cx, span, substr)
+            cs_partial_cmp(cx, span, substr, tag_then_data)
         })),
     };
 
@@ -38,6 +59,7 @@ pub fn expand_deriving_partial_ord(
         span,
         path: path_std!(cmp::PartialOrd),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: vec![],
         supports_unions: false,
         methods: vec![partial_cmp_def],
@@ -47,7 +69,12 @@ pub fn expand_deriving_partial_ord(
     trait_def.expand(cx, mitem, item, push)
 }
 
-pub fn cs_partial_cmp(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>) -> BlockOrExpr {
+fn cs_partial_cmp(
+    cx: &mut ExtCtxt<'_>,
+    span: Span,
+    substr: &Substructure<'_>,
+    tag_then_data: bool,
+) -> BlockOrExpr {
     let test_id = Ident::new(sym::cmp, span);
     let equal_path = cx.path_global(span, cx.std_path(&[sym::cmp, sym::Ordering, sym::Equal]));
     let partial_cmp_path = cx.std_path(&[sym::cmp, sym::PartialOrd, sym::partial_cmp]);
@@ -74,12 +101,50 @@ pub fn cs_partial_cmp(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_
                 let args = vec![field.self_expr.clone(), other_expr.clone()];
                 cx.expr_call_global(field.span, partial_cmp_path.clone(), args)
             }
-            CsFold::Combine(span, expr1, expr2) => {
-                let eq_arm =
-                    cx.arm(span, cx.pat_some(span, cx.pat_path(span, equal_path.clone())), expr1);
-                let neq_arm =
-                    cx.arm(span, cx.pat_ident(span, test_id), cx.expr_ident(span, test_id));
-                cx.expr_match(span, expr2, vec![eq_arm, neq_arm])
+            CsFold::Combine(span, mut expr1, expr2) => {
+                // When the item is an enum, this expands to
+                // ```
+                // match (expr2) {
+                //     Some(Ordering::Equal) => expr1,
+                //     cmp => cmp
+                // }
+                // ```
+                // where `expr2` is `partial_cmp(self_tag, other_tag)`, and `expr1` is a `match`
+                //  against the enum variants. This means that we begin by comparing the enum tags,
+                // before either inspecting their contents (if they match), or returning
+                // the `cmp::Ordering` of comparing the enum tags.
+                // ```
+                // match partial_cmp(self_tag, other_tag) {
+                //     Some(Ordering::Equal) => match (self, other)  {
+                //         (Self::A(self_0), Self::A(other_0)) => partial_cmp(self_0, other_0),
+                //         (Self::B(self_0), Self::B(other_0)) => partial_cmp(self_0, other_0),
+                //         _ => Some(Ordering::Equal)
+                //     }
+                //     cmp => cmp
+                // }
+                // ```
+                // If we have any certain enum layouts, flipping this results in better codegen
+                // ```
+                // match (self, other) {
+                //     (Self::A(self_0), Self::A(other_0)) => partial_cmp(self_0, other_0),
+                //     _ => partial_cmp(self_tag, other_tag)
+                // }
+                // ```
+                // Reference: https://github.com/rust-lang/rust/pull/103659#issuecomment-1328126354
+
+                if !tag_then_data
+                    && let ExprKind::Match(_, arms) = &mut expr1.kind
+                    && let Some(last) = arms.last_mut()
+                    && let PatKind::Wild = last.pat.kind {
+                        last.body = expr2;
+                        expr1
+                } else {
+                    let eq_arm =
+                        cx.arm(span, cx.pat_some(span, cx.pat_path(span, equal_path.clone())), expr1);
+                    let neq_arm =
+                        cx.arm(span, cx.pat_ident(span, test_id), cx.expr_ident(span, test_id));
+                    cx.expr_match(span, expr2, vec![eq_arm, neq_arm])
+                }
             }
             CsFold::Fieldless => cx.expr_some(span, cx.expr_path(equal_path.clone())),
         },
diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs
index e0f487e8648..897048f6421 100644
--- a/compiler/rustc_builtin_macros/src/deriving/debug.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs
@@ -23,6 +23,7 @@ pub fn expand_deriving_debug(
         span,
         path: path_std!(fmt::Debug),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/decodable.rs b/compiler/rustc_builtin_macros/src/deriving/decodable.rs
index 5f9519dad1b..c783e46eda9 100644
--- a/compiler/rustc_builtin_macros/src/deriving/decodable.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/decodable.rs
@@ -25,6 +25,7 @@ pub fn expand_deriving_rustc_decodable(
         span,
         path: Path::new_(vec![krate, sym::Decodable], vec![], PathKind::Global),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index 18270747296..a6c8b111527 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -25,6 +25,7 @@ pub fn expand_deriving_default(
         span,
         path: Path::new(vec![kw::Default, sym::Default]),
         skip_path_as_bound: has_a_default_variant(item),
+        needs_copy_as_bound_if_packed: false,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/encodable.rs b/compiler/rustc_builtin_macros/src/deriving/encodable.rs
index 2afeed927ac..a5e2b599df4 100644
--- a/compiler/rustc_builtin_macros/src/deriving/encodable.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/encodable.rs
@@ -109,6 +109,7 @@ pub fn expand_deriving_rustc_encodable(
         span,
         path: Path::new_(vec![krate, sym::Encodable], vec![], PathKind::Global),
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index 17b7ac0eba1..97de40bac34 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -165,11 +165,12 @@ pub use SubstructureFields::*;
 use crate::deriving;
 use rustc_ast::ptr::P;
 use rustc_ast::{
-    self as ast, BindingAnnotation, ByRef, EnumDef, Expr, Generics, Mutability, PatKind,
+    self as ast, BindingAnnotation, ByRef, EnumDef, Expr, GenericArg, GenericParamKind, Generics,
+    Mutability, PatKind, TyKind, VariantData,
 };
-use rustc_ast::{GenericArg, GenericParamKind, VariantData};
 use rustc_attr as attr;
 use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_session::lint::builtin::BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use std::cell::RefCell;
@@ -191,6 +192,9 @@ pub struct TraitDef<'a> {
     /// Whether to skip adding the current trait as a bound to the type parameters of the type.
     pub skip_path_as_bound: bool,
 
+    /// Whether `Copy` is needed as an additional bound on type parameters in a packed struct.
+    pub needs_copy_as_bound_if_packed: bool,
+
     /// Additional bounds required of any type parameters of the type,
     /// other than the current trait
     pub additional_bounds: Vec<Ty>,
@@ -455,18 +459,6 @@ impl<'a> TraitDef<'a> {
                     }
                     false
                 });
-                let has_no_type_params = match &item.kind {
-                    ast::ItemKind::Struct(_, generics)
-                    | ast::ItemKind::Enum(_, generics)
-                    | ast::ItemKind::Union(_, generics) => !generics
-                        .params
-                        .iter()
-                        .any(|param| matches!(param.kind, ast::GenericParamKind::Type { .. })),
-                    _ => unreachable!(),
-                };
-                let container_id = cx.current_expansion.id.expn_data().parent.expect_local();
-                let copy_fields =
-                    is_packed && has_no_type_params && cx.resolver.has_derive_copy(container_id);
 
                 let newitem = match &item.kind {
                     ast::ItemKind::Struct(struct_def, generics) => self.expand_struct_def(
@@ -475,7 +467,7 @@ impl<'a> TraitDef<'a> {
                         item.ident,
                         generics,
                         from_scratch,
-                        copy_fields,
+                        is_packed,
                     ),
                     ast::ItemKind::Enum(enum_def, generics) => {
                         // We ignore `is_packed` here, because `repr(packed)`
@@ -493,7 +485,7 @@ impl<'a> TraitDef<'a> {
                                 item.ident,
                                 generics,
                                 from_scratch,
-                                copy_fields,
+                                is_packed,
                             )
                         } else {
                             cx.span_err(mitem.span, "this trait cannot be derived for unions");
@@ -565,6 +557,7 @@ impl<'a> TraitDef<'a> {
         generics: &Generics,
         field_tys: Vec<P<ast::Ty>>,
         methods: Vec<P<ast::AssocItem>>,
+        is_packed: bool,
     ) -> P<ast::Item> {
         let trait_path = self.path.to_path(cx, self.span, type_ident, generics);
 
@@ -607,20 +600,32 @@ impl<'a> TraitDef<'a> {
             .map(|param| match &param.kind {
                 GenericParamKind::Lifetime { .. } => param.clone(),
                 GenericParamKind::Type { .. } => {
-                    // I don't think this can be moved out of the loop, since
-                    // a GenericBound requires an ast id
-                    let bounds: Vec<_> =
-                    // extra restrictions on the generics parameters to the
-                    // type being derived upon
-                    self.additional_bounds.iter().map(|p| {
-                        cx.trait_bound(p.to_path(cx, self.span, type_ident, generics))
-                    }).chain(
-                        // require the current trait
-                        self.skip_path_as_bound.not().then(|| cx.trait_bound(trait_path.clone()))
-                    ).chain(
-                        // also add in any bounds from the declaration
-                        param.bounds.iter().cloned()
-                    ).collect();
+                    // Extra restrictions on the generics parameters to the
+                    // type being derived upon.
+                    let bounds: Vec<_> = self
+                        .additional_bounds
+                        .iter()
+                        .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                        .chain(
+                            // Add a bound for the current trait.
+                            self.skip_path_as_bound
+                                .not()
+                                .then(|| cx.trait_bound(trait_path.clone())),
+                        )
+                        .chain({
+                            // Add a `Copy` bound if required.
+                            if is_packed && self.needs_copy_as_bound_if_packed {
+                                let p = deriving::path_std!(marker::Copy);
+                                Some(cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                            } else {
+                                None
+                            }
+                        })
+                        .chain(
+                            // Also add in any bounds from the declaration.
+                            param.bounds.iter().cloned(),
+                        )
+                        .collect();
 
                     cx.typaram(param.ident.span.with_ctxt(ctxt), param.ident, bounds, None)
                 }
@@ -692,9 +697,17 @@ impl<'a> TraitDef<'a> {
                             .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
                             .collect();
 
-                        // require the current trait
+                        // Require the current trait.
                         bounds.push(cx.trait_bound(trait_path.clone()));
 
+                        // Add a `Copy` bound if required.
+                        if is_packed && self.needs_copy_as_bound_if_packed {
+                            let p = deriving::path_std!(marker::Copy);
+                            bounds.push(
+                                cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)),
+                            );
+                        }
+
                         let predicate = ast::WhereBoundPredicate {
                             span: self.span,
                             bound_generic_params: field_ty_param.bound_generic_params,
@@ -762,7 +775,7 @@ impl<'a> TraitDef<'a> {
         type_ident: Ident,
         generics: &Generics,
         from_scratch: bool,
-        copy_fields: bool,
+        is_packed: bool,
     ) -> P<ast::Item> {
         let field_tys: Vec<P<ast::Ty>> =
             struct_def.fields().iter().map(|field| field.ty.clone()).collect();
@@ -790,7 +803,7 @@ impl<'a> TraitDef<'a> {
                         type_ident,
                         &selflike_args,
                         &nonselflike_args,
-                        copy_fields,
+                        is_packed,
                     )
                 };
 
@@ -806,7 +819,7 @@ impl<'a> TraitDef<'a> {
             })
             .collect();
 
-        self.create_derived_impl(cx, type_ident, generics, field_tys, methods)
+        self.create_derived_impl(cx, type_ident, generics, field_tys, methods, is_packed)
     }
 
     fn expand_enum_def(
@@ -861,7 +874,8 @@ impl<'a> TraitDef<'a> {
             })
             .collect();
 
-        self.create_derived_impl(cx, type_ident, generics, field_tys, methods)
+        let is_packed = false; // enums are never packed
+        self.create_derived_impl(cx, type_ident, generics, field_tys, methods, is_packed)
     }
 }
 
@@ -1011,8 +1025,8 @@ impl<'a> MethodDef<'a> {
     /// ```
     /// But if the struct is `repr(packed)`, we can't use something like
     /// `&self.x` because that might cause an unaligned ref. So for any trait
-    /// method that takes a reference, if the struct impls `Copy` then we use a
-    /// local block to force a copy:
+    /// method that takes a reference, we use a local block to force a copy.
+    /// This requires that the field impl `Copy`.
     /// ```
     /// # struct A { x: u8, y: u8 }
     /// impl PartialEq for A {
@@ -1027,10 +1041,6 @@ impl<'a> MethodDef<'a> {
     ///         ::core::hash::Hash::hash(&{ self.y }, state)
     ///     }
     /// }
-    /// ```
-    /// If the struct doesn't impl `Copy`, we use the normal `&self.x`. This
-    /// only works if the fields match the alignment required by the
-    /// `packed(N)` attribute. (We'll get errors later on if not.)
     fn expand_struct_method_body<'b>(
         &self,
         cx: &mut ExtCtxt<'_>,
@@ -1039,12 +1049,12 @@ impl<'a> MethodDef<'a> {
         type_ident: Ident,
         selflike_args: &[P<Expr>],
         nonselflike_args: &[P<Expr>],
-        copy_fields: bool,
+        is_packed: bool,
     ) -> BlockOrExpr {
         assert!(selflike_args.len() == 1 || selflike_args.len() == 2);
 
         let selflike_fields =
-            trait_.create_struct_field_access_fields(cx, selflike_args, struct_def, copy_fields);
+            trait_.create_struct_field_access_fields(cx, selflike_args, struct_def, is_packed);
         self.call_substructure_method(
             cx,
             trait_,
@@ -1514,7 +1524,7 @@ impl<'a> TraitDef<'a> {
         cx: &mut ExtCtxt<'_>,
         selflike_args: &[P<Expr>],
         struct_def: &'a VariantData,
-        copy_fields: bool,
+        is_packed: bool,
     ) -> Vec<FieldInfo> {
         self.create_fields(struct_def, |i, struct_field, sp| {
             selflike_args
@@ -1533,10 +1543,39 @@ impl<'a> TraitDef<'a> {
                             }),
                         ),
                     );
-                    if copy_fields {
-                        field_expr = cx.expr_block(
-                            cx.block(struct_field.span, vec![cx.stmt_expr(field_expr)]),
-                        );
+                    // In general, fields in packed structs are copied via a
+                    // block, e.g. `&{self.0}`. The one exception is `[u8]`
+                    // fields, which cannot be copied and also never cause
+                    // unaligned references. This exception is allowed to
+                    // handle the `FlexZeroSlice` type in the `zerovec` crate
+                    // within `icu4x-0.9.0`.
+                    //
+                    // Once use of `icu4x-0.9.0` has dropped sufficiently, this
+                    // exception should be removed.
+                    let is_u8_slice = if let TyKind::Slice(ty) = &struct_field.ty.kind &&
+                        let TyKind::Path(None, rustc_ast::Path { segments, .. }) = &ty.kind &&
+                        let [seg] = segments.as_slice() &&
+                        seg.ident.name == sym::u8 && seg.args.is_none()
+                    {
+                        true
+                    } else {
+                        false
+                    };
+                    if is_packed {
+                        if is_u8_slice {
+                            cx.sess.parse_sess.buffer_lint_with_diagnostic(
+                                BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
+                                sp,
+                                ast::CRATE_NODE_ID,
+                                "byte slice in a packed struct that derives a built-in trait",
+                                rustc_lint_defs::BuiltinLintDiagnostics::ByteSliceInPackedStructWithDerive
+                            );
+                        } else {
+                            // Wrap the expression in `{...}`, causing a copy.
+                            field_expr = cx.expr_block(
+                                cx.block(struct_field.span, vec![cx.stmt_expr(field_expr)]),
+                            );
+                        }
                     }
                     cx.expr_addr_of(sp, field_expr)
                 })
diff --git a/compiler/rustc_builtin_macros/src/deriving/hash.rs b/compiler/rustc_builtin_macros/src/deriving/hash.rs
index f8570d8f86a..5c2e89c5697 100644
--- a/compiler/rustc_builtin_macros/src/deriving/hash.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/hash.rs
@@ -24,6 +24,7 @@ pub fn expand_deriving_hash(
         span,
         path,
         skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: true,
         additional_bounds: Vec::new(),
         supports_unions: false,
         methods: vec![MethodDef {
diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs
index 9f4bbbc62c8..e93a23394c0 100644
--- a/compiler/rustc_builtin_macros/src/format.rs
+++ b/compiler/rustc_builtin_macros/src/format.rs
@@ -1,7 +1,11 @@
 use rustc_ast::ptr::P;
 use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
-use rustc_ast::Expr;
+use rustc_ast::{
+    Expr, ExprKind, FormatAlignment, FormatArgPosition, FormatArgPositionKind, FormatArgs,
+    FormatArgsPiece, FormatArgument, FormatArgumentKind, FormatArguments, FormatCount,
+    FormatDebugHex, FormatOptions, FormatPlaceholder, FormatSign, FormatTrait,
+};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{pluralize, Applicability, MultiSpan, PResult};
 use rustc_expand::base::{self, *};
@@ -12,21 +16,15 @@ use rustc_span::{BytePos, InnerSpan, Span};
 use rustc_lint_defs::builtin::NAMED_ARGUMENTS_USED_POSITIONALLY;
 use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, LintId};
 
-mod ast;
-use ast::*;
-
-mod expand;
-use expand::expand_parsed_format_args;
-
 // The format_args!() macro is expanded in three steps:
 //  1. First, `parse_args` will parse the `(literal, arg, arg, name=arg, name=arg)` syntax,
 //     but doesn't parse the template (the literal) itself.
 //  2. Second, `make_format_args` will parse the template, the format options, resolve argument references,
-//     produce diagnostics, and turn the whole thing into a `FormatArgs` structure.
-//  3. Finally, `expand_parsed_format_args` will turn that `FormatArgs` structure
-//     into the expression that the macro expands to.
+//     produce diagnostics, and turn the whole thing into a `FormatArgs` AST node.
+//  3. Much later, in AST lowering (rustc_ast_lowering), that `FormatArgs` structure will be turned
+//     into the expression of type `core::fmt::Arguments`.
 
-// See format/ast.rs for the FormatArgs structure and glossary.
+// See rustc_ast/src/format.rs for the FormatArgs structure and glossary.
 
 // Only used in parse_args and report_invalid_references,
 // to indicate how a referred argument was used.
@@ -437,7 +435,16 @@ pub fn make_format_args(
                     format_options: FormatOptions {
                         fill: format.fill,
                         alignment,
-                        flags: format.flags,
+                        sign: format.sign.map(|s| match s {
+                            parse::Sign::Plus => FormatSign::Plus,
+                            parse::Sign::Minus => FormatSign::Minus,
+                        }),
+                        alternate: format.alternate,
+                        zero_pad: format.zero_pad,
+                        debug_hex: format.debug_hex.map(|s| match s {
+                            parse::DebugHex::Lower => FormatDebugHex::Lower,
+                            parse::DebugHex::Upper => FormatDebugHex::Upper,
+                        }),
                         precision,
                         width,
                     },
@@ -850,7 +857,7 @@ fn expand_format_args_impl<'cx>(
     match parse_args(ecx, sp, tts) {
         Ok((efmt, args)) => {
             if let Ok(format_args) = make_format_args(ecx, efmt, args, nl) {
-                MacEager::expr(expand_parsed_format_args(ecx, format_args))
+                MacEager::expr(ecx.expr(sp, ExprKind::FormatArgs(P(format_args))))
             } else {
                 MacEager::expr(DummyResult::raw_expr(sp, true))
             }
diff --git a/compiler/rustc_builtin_macros/src/format/expand.rs b/compiler/rustc_builtin_macros/src/format/expand.rs
deleted file mode 100644
index 9dde5efcb28..00000000000
--- a/compiler/rustc_builtin_macros/src/format/expand.rs
+++ /dev/null
@@ -1,353 +0,0 @@
-use super::*;
-use rustc_ast as ast;
-use rustc_ast::visit::{self, Visitor};
-use rustc_ast::{BlockCheckMode, UnsafeSource};
-use rustc_data_structures::fx::FxIndexSet;
-use rustc_span::{sym, symbol::kw};
-
-#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
-enum ArgumentType {
-    Format(FormatTrait),
-    Usize,
-}
-
-fn make_argument(ecx: &ExtCtxt<'_>, sp: Span, arg: P<ast::Expr>, ty: ArgumentType) -> P<ast::Expr> {
-    // Generate:
-    //     ::core::fmt::ArgumentV1::new_…(arg)
-    use ArgumentType::*;
-    use FormatTrait::*;
-    ecx.expr_call_global(
-        sp,
-        ecx.std_path(&[
-            sym::fmt,
-            sym::ArgumentV1,
-            match ty {
-                Format(Display) => sym::new_display,
-                Format(Debug) => sym::new_debug,
-                Format(LowerExp) => sym::new_lower_exp,
-                Format(UpperExp) => sym::new_upper_exp,
-                Format(Octal) => sym::new_octal,
-                Format(Pointer) => sym::new_pointer,
-                Format(Binary) => sym::new_binary,
-                Format(LowerHex) => sym::new_lower_hex,
-                Format(UpperHex) => sym::new_upper_hex,
-                Usize => sym::from_usize,
-            },
-        ]),
-        vec![arg],
-    )
-}
-
-fn make_count(
-    ecx: &ExtCtxt<'_>,
-    sp: Span,
-    count: &Option<FormatCount>,
-    argmap: &mut FxIndexSet<(usize, ArgumentType)>,
-) -> P<ast::Expr> {
-    // Generate:
-    //     ::core::fmt::rt::v1::Count::…(…)
-    match count {
-        Some(FormatCount::Literal(n)) => ecx.expr_call_global(
-            sp,
-            ecx.std_path(&[sym::fmt, sym::rt, sym::v1, sym::Count, sym::Is]),
-            vec![ecx.expr_usize(sp, *n)],
-        ),
-        Some(FormatCount::Argument(arg)) => {
-            if let Ok(arg_index) = arg.index {
-                let (i, _) = argmap.insert_full((arg_index, ArgumentType::Usize));
-                ecx.expr_call_global(
-                    sp,
-                    ecx.std_path(&[sym::fmt, sym::rt, sym::v1, sym::Count, sym::Param]),
-                    vec![ecx.expr_usize(sp, i)],
-                )
-            } else {
-                DummyResult::raw_expr(sp, true)
-            }
-        }
-        None => ecx.expr_path(ecx.path_global(
-            sp,
-            ecx.std_path(&[sym::fmt, sym::rt, sym::v1, sym::Count, sym::Implied]),
-        )),
-    }
-}
-
-fn make_format_spec(
-    ecx: &ExtCtxt<'_>,
-    sp: Span,
-    placeholder: &FormatPlaceholder,
-    argmap: &mut FxIndexSet<(usize, ArgumentType)>,
-) -> P<ast::Expr> {
-    // Generate:
-    //     ::core::fmt::rt::v1::Argument {
-    //         position: 0usize,
-    //         format: ::core::fmt::rt::v1::FormatSpec {
-    //             fill: ' ',
-    //             align: ::core::fmt::rt::v1::Alignment::Unknown,
-    //             flags: 0u32,
-    //             precision: ::core::fmt::rt::v1::Count::Implied,
-    //             width: ::core::fmt::rt::v1::Count::Implied,
-    //         },
-    //     }
-    let position = match placeholder.argument.index {
-        Ok(arg_index) => {
-            let (i, _) =
-                argmap.insert_full((arg_index, ArgumentType::Format(placeholder.format_trait)));
-            ecx.expr_usize(sp, i)
-        }
-        Err(_) => DummyResult::raw_expr(sp, true),
-    };
-    let fill = ecx.expr_char(sp, placeholder.format_options.fill.unwrap_or(' '));
-    let align = ecx.expr_path(ecx.path_global(
-        sp,
-        ecx.std_path(&[
-            sym::fmt,
-            sym::rt,
-            sym::v1,
-            sym::Alignment,
-            match placeholder.format_options.alignment {
-                Some(FormatAlignment::Left) => sym::Left,
-                Some(FormatAlignment::Right) => sym::Right,
-                Some(FormatAlignment::Center) => sym::Center,
-                None => sym::Unknown,
-            },
-        ]),
-    ));
-    let flags = ecx.expr_u32(sp, placeholder.format_options.flags);
-    let prec = make_count(ecx, sp, &placeholder.format_options.precision, argmap);
-    let width = make_count(ecx, sp, &placeholder.format_options.width, argmap);
-    ecx.expr_struct(
-        sp,
-        ecx.path_global(sp, ecx.std_path(&[sym::fmt, sym::rt, sym::v1, sym::Argument])),
-        vec![
-            ecx.field_imm(sp, Ident::new(sym::position, sp), position),
-            ecx.field_imm(
-                sp,
-                Ident::new(sym::format, sp),
-                ecx.expr_struct(
-                    sp,
-                    ecx.path_global(
-                        sp,
-                        ecx.std_path(&[sym::fmt, sym::rt, sym::v1, sym::FormatSpec]),
-                    ),
-                    vec![
-                        ecx.field_imm(sp, Ident::new(sym::fill, sp), fill),
-                        ecx.field_imm(sp, Ident::new(sym::align, sp), align),
-                        ecx.field_imm(sp, Ident::new(sym::flags, sp), flags),
-                        ecx.field_imm(sp, Ident::new(sym::precision, sp), prec),
-                        ecx.field_imm(sp, Ident::new(sym::width, sp), width),
-                    ],
-                ),
-            ),
-        ],
-    )
-}
-
-pub fn expand_parsed_format_args(ecx: &mut ExtCtxt<'_>, fmt: FormatArgs) -> P<ast::Expr> {
-    let macsp = ecx.with_def_site_ctxt(ecx.call_site());
-
-    let lit_pieces = ecx.expr_array_ref(
-        fmt.span,
-        fmt.template
-            .iter()
-            .enumerate()
-            .filter_map(|(i, piece)| match piece {
-                &FormatArgsPiece::Literal(s) => Some(ecx.expr_str(fmt.span, s)),
-                &FormatArgsPiece::Placeholder(_) => {
-                    // Inject empty string before placeholders when not already preceded by a literal piece.
-                    if i == 0 || matches!(fmt.template[i - 1], FormatArgsPiece::Placeholder(_)) {
-                        Some(ecx.expr_str(fmt.span, kw::Empty))
-                    } else {
-                        None
-                    }
-                }
-            })
-            .collect(),
-    );
-
-    // Whether we'll use the `Arguments::new_v1_formatted` form (true),
-    // or the `Arguments::new_v1` form (false).
-    let mut use_format_options = false;
-
-    // Create a list of all _unique_ (argument, format trait) combinations.
-    // E.g. "{0} {0:x} {0} {1}" -> [(0, Display), (0, LowerHex), (1, Display)]
-    let mut argmap = FxIndexSet::default();
-    for piece in &fmt.template {
-        let FormatArgsPiece::Placeholder(placeholder) = piece else { continue };
-        if placeholder.format_options != Default::default() {
-            // Can't use basic form if there's any formatting options.
-            use_format_options = true;
-        }
-        if let Ok(index) = placeholder.argument.index {
-            if !argmap.insert((index, ArgumentType::Format(placeholder.format_trait))) {
-                // Duplicate (argument, format trait) combination,
-                // which we'll only put once in the args array.
-                use_format_options = true;
-            }
-        }
-    }
-
-    let format_options = use_format_options.then(|| {
-        // Generate:
-        //     &[format_spec_0, format_spec_1, format_spec_2]
-        ecx.expr_array_ref(
-            macsp,
-            fmt.template
-                .iter()
-                .filter_map(|piece| {
-                    let FormatArgsPiece::Placeholder(placeholder) = piece else { return None };
-                    Some(make_format_spec(ecx, macsp, placeholder, &mut argmap))
-                })
-                .collect(),
-        )
-    });
-
-    let arguments = fmt.arguments.into_vec();
-
-    // If the args array contains exactly all the original arguments once,
-    // in order, we can use a simple array instead of a `match` construction.
-    // However, if there's a yield point in any argument except the first one,
-    // we don't do this, because an ArgumentV1 cannot be kept across yield points.
-    let use_simple_array = argmap.len() == arguments.len()
-        && argmap.iter().enumerate().all(|(i, &(j, _))| i == j)
-        && arguments.iter().skip(1).all(|arg| !may_contain_yield_point(&arg.expr));
-
-    let args = if use_simple_array {
-        // Generate:
-        //     &[
-        //         ::core::fmt::ArgumentV1::new_display(&arg0),
-        //         ::core::fmt::ArgumentV1::new_lower_hex(&arg1),
-        //         ::core::fmt::ArgumentV1::new_debug(&arg2),
-        //     ]
-        ecx.expr_array_ref(
-            macsp,
-            arguments
-                .into_iter()
-                .zip(argmap)
-                .map(|(arg, (_, ty))| {
-                    let sp = arg.expr.span.with_ctxt(macsp.ctxt());
-                    make_argument(ecx, sp, ecx.expr_addr_of(sp, arg.expr), ty)
-                })
-                .collect(),
-        )
-    } else {
-        // Generate:
-        //     match (&arg0, &arg1, &arg2) {
-        //         args => &[
-        //             ::core::fmt::ArgumentV1::new_display(args.0),
-        //             ::core::fmt::ArgumentV1::new_lower_hex(args.1),
-        //             ::core::fmt::ArgumentV1::new_debug(args.0),
-        //         ]
-        //     }
-        let args_ident = Ident::new(sym::args, macsp);
-        let args = argmap
-            .iter()
-            .map(|&(arg_index, ty)| {
-                if let Some(arg) = arguments.get(arg_index) {
-                    let sp = arg.expr.span.with_ctxt(macsp.ctxt());
-                    make_argument(
-                        ecx,
-                        sp,
-                        ecx.expr_field(
-                            sp,
-                            ecx.expr_ident(macsp, args_ident),
-                            Ident::new(sym::integer(arg_index), macsp),
-                        ),
-                        ty,
-                    )
-                } else {
-                    DummyResult::raw_expr(macsp, true)
-                }
-            })
-            .collect();
-        ecx.expr_addr_of(
-            macsp,
-            ecx.expr_match(
-                macsp,
-                ecx.expr_tuple(
-                    macsp,
-                    arguments
-                        .into_iter()
-                        .map(|arg| {
-                            ecx.expr_addr_of(arg.expr.span.with_ctxt(macsp.ctxt()), arg.expr)
-                        })
-                        .collect(),
-                ),
-                vec![ecx.arm(macsp, ecx.pat_ident(macsp, args_ident), ecx.expr_array(macsp, args))],
-            ),
-        )
-    };
-
-    if let Some(format_options) = format_options {
-        // Generate:
-        //     ::core::fmt::Arguments::new_v1_formatted(
-        //         lit_pieces,
-        //         args,
-        //         format_options,
-        //         unsafe { ::core::fmt::UnsafeArg::new() }
-        //     )
-        ecx.expr_call_global(
-            macsp,
-            ecx.std_path(&[sym::fmt, sym::Arguments, sym::new_v1_formatted]),
-            vec![
-                lit_pieces,
-                args,
-                format_options,
-                ecx.expr_block(P(ast::Block {
-                    stmts: vec![ecx.stmt_expr(ecx.expr_call_global(
-                        macsp,
-                        ecx.std_path(&[sym::fmt, sym::UnsafeArg, sym::new]),
-                        Vec::new(),
-                    ))],
-                    id: ast::DUMMY_NODE_ID,
-                    rules: BlockCheckMode::Unsafe(UnsafeSource::CompilerGenerated),
-                    span: macsp,
-                    tokens: None,
-                    could_be_bare_literal: false,
-                })),
-            ],
-        )
-    } else {
-        // Generate:
-        //     ::core::fmt::Arguments::new_v1(
-        //         lit_pieces,
-        //         args,
-        //     )
-        ecx.expr_call_global(
-            macsp,
-            ecx.std_path(&[sym::fmt, sym::Arguments, sym::new_v1]),
-            vec![lit_pieces, args],
-        )
-    }
-}
-
-fn may_contain_yield_point(e: &ast::Expr) -> bool {
-    struct MayContainYieldPoint(bool);
-
-    impl Visitor<'_> for MayContainYieldPoint {
-        fn visit_expr(&mut self, e: &ast::Expr) {
-            if let ast::ExprKind::Await(_) | ast::ExprKind::Yield(_) = e.kind {
-                self.0 = true;
-            } else {
-                visit::walk_expr(self, e);
-            }
-        }
-
-        fn visit_mac_call(&mut self, _: &ast::MacCall) {
-            self.0 = true;
-        }
-
-        fn visit_attribute(&mut self, _: &ast::Attribute) {
-            // Conservatively assume this may be a proc macro attribute in
-            // expression position.
-            self.0 = true;
-        }
-
-        fn visit_item(&mut self, _: &ast::Item) {
-            // Do not recurse into nested items.
-        }
-    }
-
-    let mut visitor = MayContainYieldPoint(false);
-    visitor.visit_expr(e);
-    visitor.0
-}
diff --git a/compiler/rustc_codegen_cranelift/.cirrus.yml b/compiler/rustc_codegen_cranelift/.cirrus.yml
index d627c2ee09c..7886cae42a1 100644
--- a/compiler/rustc_codegen_cranelift/.cirrus.yml
+++ b/compiler/rustc_codegen_cranelift/.cirrus.yml
@@ -1,13 +1,11 @@
 task:
   name: freebsd
   freebsd_instance:
-    image: freebsd-12-1-release-amd64
+    image: freebsd-13-1-release-amd64
   setup_rust_script:
     - pkg install -y curl git bash
     - curl https://sh.rustup.rs -sSf --output rustup.sh
     - sh rustup.sh --default-toolchain none -y --profile=minimal
-  cargo_bin_cache:
-    folder: ~/.cargo/bin
   target_cache:
     folder: target
   prepare_script:
@@ -15,9 +13,4 @@ task:
     - ./y.rs prepare
   test_script:
     - . $HOME/.cargo/env
-    - # Enable backtraces for easier debugging
-    - export RUST_BACKTRACE=1
-    - # Reduce amount of benchmark runs as they are slow
-    - export COMPILE_RUNS=2
-    - export RUN_RUNS=2
     - ./y.rs test
diff --git a/compiler/rustc_codegen_cranelift/.github/workflows/main.yml b/compiler/rustc_codegen_cranelift/.github/workflows/main.yml
index a6bb12a66a2..c0daf69e98e 100644
--- a/compiler/rustc_codegen_cranelift/.github/workflows/main.yml
+++ b/compiler/rustc_codegen_cranelift/.github/workflows/main.yml
@@ -25,6 +25,10 @@ jobs:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
 
+    defaults:
+      run:
+        shell: bash
+
     strategy:
       fail-fast: false
       matrix:
@@ -46,36 +50,31 @@ jobs:
           - os: ubuntu-latest
             env:
               TARGET_TRIPLE: s390x-unknown-linux-gnu
+          - os: windows-latest
+            env:
+              TARGET_TRIPLE: x86_64-pc-windows-msvc
+          - os: windows-latest
+            env:
+              TARGET_TRIPLE: x86_64-pc-windows-gnu
 
     steps:
     - uses: actions/checkout@v3
 
-    - name: Cache cargo installed crates
-      uses: actions/cache@v3
-      with:
-        path: ~/.cargo/bin
-        key: ${{ runner.os }}-cargo-installed-crates
-
-    - name: Cache cargo registry and index
-      uses: actions/cache@v3
-      with:
-        path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-        key: ${{ runner.os }}-cargo-registry-and-index-${{ hashFiles('**/Cargo.lock') }}
-
     - name: Cache cargo target dir
       uses: actions/cache@v3
       with:
         path: build/cg_clif
-        key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
+        key: ${{ runner.os }}-${{ matrix.env.TARGET_TRIPLE }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
+
+    - name: Set MinGW as the default toolchain
+      if: matrix.os == 'windows-latest' && matrix.env.TARGET_TRIPLE == 'x86_64-pc-windows-gnu'
+      run: rustup set default-host x86_64-pc-windows-gnu
 
     - name: Install MinGW toolchain and wine
       if: matrix.os == 'ubuntu-latest' && matrix.env.TARGET_TRIPLE == 'x86_64-pc-windows-gnu'
       run: |
         sudo apt-get update
         sudo apt-get install -y gcc-mingw-w64-x86-64 wine-stable
-        rustup target add x86_64-pc-windows-gnu
 
     - name: Install AArch64 toolchain and qemu
       if: matrix.os == 'ubuntu-latest' && matrix.env.TARGET_TRIPLE == 'aarch64-unknown-linux-gnu'
@@ -89,6 +88,13 @@ jobs:
         sudo apt-get update
         sudo apt-get install -y gcc-s390x-linux-gnu qemu-user
 
+    - name: Use sparse cargo registry
+      run: |
+        cat >> ~/.cargo/config.toml <<EOF
+        [unstable]
+        sparse-registry = true
+        EOF
+
     - name: Prepare dependencies
       run: ./y.rs prepare
 
@@ -104,49 +110,47 @@ jobs:
     - name: Test
       env:
         TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
-      run: |
-        # Enable backtraces for easier debugging
-        export RUST_BACKTRACE=1
-
-        # Reduce amount of benchmark runs as they are slow
-        export COMPILE_RUNS=2
-        export RUN_RUNS=2
-
-        # Enable extra checks
-        export CG_CLIF_ENABLE_VERIFIER=1
-
-        ./y.rs test
+      run: ./y.rs test
 
     - name: Package prebuilt cg_clif
       run: tar cvfJ cg_clif.tar.xz dist
 
     - name: Upload prebuilt cg_clif
-      if: matrix.env.TARGET_TRIPLE != 'x86_64-pc-windows-gnu'
-      uses: actions/upload-artifact@v2
+      if: matrix.os == 'windows-latest' || matrix.env.TARGET_TRIPLE != 'x86_64-pc-windows-gnu'
+      uses: actions/upload-artifact@v3
       with:
         name: cg_clif-${{ matrix.env.TARGET_TRIPLE }}
         path: cg_clif.tar.xz
 
     - name: Upload prebuilt cg_clif (cross compile)
-      if: matrix.env.TARGET_TRIPLE == 'x86_64-pc-windows-gnu'
+      if: matrix.os != 'windows-latest' && matrix.env.TARGET_TRIPLE == 'x86_64-pc-windows-gnu'
       uses: actions/upload-artifact@v3
       with:
         name: cg_clif-${{ runner.os }}-cross-x86_64-mingw
         path: cg_clif.tar.xz
 
-  windows:
+
+  abi_cafe:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
 
+    defaults:
+      run:
+        shell: bash
+
     strategy:
-      fail-fast: false
+      fail-fast: true
       matrix:
         include:
-          # Native Windows build with MSVC
+          - os: ubuntu-latest
+            env:
+              TARGET_TRIPLE: x86_64-unknown-linux-gnu
+          - os: macos-latest
+            env:
+              TARGET_TRIPLE: x86_64-apple-darwin
           - os: windows-latest
             env:
               TARGET_TRIPLE: x86_64-pc-windows-msvc
-          # cross-compile from Windows to Windows MinGW
           - os: windows-latest
             env:
               TARGET_TRIPLE: x86_64-pc-windows-gnu
@@ -154,20 +158,6 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
-    - name: Cache cargo installed crates
-      uses: actions/cache@v3
-      with:
-        path: ~/.cargo/bin
-        key: ${{ runner.os }}-${{ matrix.env.TARGET_TRIPLE }}-cargo-installed-crates
-
-    - name: Cache cargo registry and index
-      uses: actions/cache@v3
-      with:
-        path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-        key: ${{ runner.os }}-${{ matrix.env.TARGET_TRIPLE }}-cargo-registry-and-index-${{ hashFiles('**/Cargo.lock') }}
-
     - name: Cache cargo target dir
       uses: actions/cache@v3
       with:
@@ -178,50 +168,20 @@ jobs:
       if: matrix.env.TARGET_TRIPLE == 'x86_64-pc-windows-gnu'
       run: rustup set default-host x86_64-pc-windows-gnu
 
-    - name: Prepare dependencies
+    - name: Use sparse cargo registry
       run: |
-        git config --global core.autocrlf false
-        rustc y.rs -o y.exe -g
-        ./y.exe prepare
+        cat >> ~/.cargo/config.toml <<EOF
+        [unstable]
+        sparse-registry = true
+        EOF
 
-    - name: Build without unstable features
-      env:
-        TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
-      # This is the config rust-lang/rust uses for builds
-      run: ./y.rs build --no-unstable-features
+    - name: Prepare dependencies
+      run: ./y.rs prepare
 
     - name: Build
       run: ./y.rs build --sysroot none
 
-    - name: Test
-      run: |
-        # Enable backtraces for easier debugging
-        $Env:RUST_BACKTRACE=1
-
-        # Reduce amount of benchmark runs as they are slow
-        $Env:COMPILE_RUNS=2
-        $Env:RUN_RUNS=2
-
-        # Enable extra checks
-        $Env:CG_CLIF_ENABLE_VERIFIER=1
-
-        # WIP Disable some tests
-
-        # This fails due to some weird argument handling by hyperfine, not an actual regression
-        # more of a build system issue
-        (Get-Content config.txt) -replace '(bench.simple-raytracer)', '# $1' |  Out-File config.txt
-
-        # This fails with a different output than expected
-        (Get-Content config.txt) -replace '(test.regex-shootout-regex-dna)', '# $1' |  Out-File config.txt
-
-        ./y.exe test
-
-    - name: Package prebuilt cg_clif
-      # don't use compression as xzip isn't supported by tar on windows and bzip2 hangs
-      run: tar cvf cg_clif.tar dist
-
-    - name: Upload prebuilt cg_clif
-      uses: actions/upload-artifact@v3
-      with:
-        name: cg_clif-${{ matrix.env.TARGET_TRIPLE }}
-        path: cg_clif.tar
+    - name: Test abi-cafe
+      env:
+        TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
+      run: ./y.rs abi-cafe
diff --git a/compiler/rustc_codegen_cranelift/.github/workflows/nightly-cranelift.yml b/compiler/rustc_codegen_cranelift/.github/workflows/nightly-cranelift.yml
deleted file mode 100644
index d0d58d2a7ea..00000000000
--- a/compiler/rustc_codegen_cranelift/.github/workflows/nightly-cranelift.yml
+++ /dev/null
@@ -1,59 +0,0 @@
-name: Test nightly Cranelift
-
-on:
-  push:
-  schedule:
-    - cron: '17 1 * * *' # At 01:17 UTC every day.
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    timeout-minutes: 60
-
-    steps:
-    - uses: actions/checkout@v3
-
-    - name: Cache cargo installed crates
-      uses: actions/cache@v3
-      with:
-        path: ~/.cargo/bin
-        key: ubuntu-latest-cargo-installed-crates
-
-    - name: Prepare dependencies
-      run: |
-        git config --global user.email "user@example.com"
-        git config --global user.name "User"
-        ./y.rs prepare
-
-    - name: Patch Cranelift
-      run: |
-        sed -i 's/cranelift-codegen = { version = "\w*.\w*.\w*", features = \["unwind", "all-arch"\] }/cranelift-codegen = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git", features = ["unwind", "all-arch"] }/' Cargo.toml
-        sed -i 's/cranelift-frontend = "\w*.\w*.\w*"/cranelift-frontend = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git" }/' Cargo.toml
-        sed -i 's/cranelift-module = "\w*.\w*.\w*"/cranelift-module = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git" }/' Cargo.toml
-        sed -i 's/cranelift-native = "\w*.\w*.\w*"/cranelift-native = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git" }/' Cargo.toml
-        sed -i 's/cranelift-jit = { version = "\w*.\w*.\w*", optional = true }/cranelift-jit = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git", optional = true }/' Cargo.toml
-        sed -i 's/cranelift-object = "\w*.\w*.\w*"/cranelift-object = { git = "https:\/\/github.com\/bytecodealliance\/wasmtime.git" }/' Cargo.toml
-
-        sed -i 's/object = { version = "0.27.0"/object = { version = "0.28.0"/' Cargo.toml
-
-        cat Cargo.toml
-
-    - name: Build without unstable features
-      # This is the config rust-lang/rust uses for builds
-      run: ./y.rs build --no-unstable-features
-
-    - name: Build
-      run: ./y.rs build --sysroot none
-    - name: Test
-      run: |
-        # Enable backtraces for easier debugging
-        export RUST_BACKTRACE=1
-
-        # Reduce amount of benchmark runs as they are slow
-        export COMPILE_RUNS=2
-        export RUN_RUNS=2
-
-        # Enable extra checks
-        export CG_CLIF_ENABLE_VERIFIER=1
-
-        ./test.sh
diff --git a/compiler/rustc_codegen_cranelift/.github/workflows/rustc.yml b/compiler/rustc_codegen_cranelift/.github/workflows/rustc.yml
index bef806318ef..5faa8f05404 100644
--- a/compiler/rustc_codegen_cranelift/.github/workflows/rustc.yml
+++ b/compiler/rustc_codegen_cranelift/.github/workflows/rustc.yml
@@ -10,73 +10,45 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
-    - name: Cache cargo installed crates
-      uses: actions/cache@v3
-      with:
-        path: ~/.cargo/bin
-        key: ${{ runner.os }}-cargo-installed-crates
-
-    - name: Cache cargo registry and index
-      uses: actions/cache@v3
-      with:
-        path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-        key: ${{ runner.os }}-cargo-registry-and-index-${{ hashFiles('**/Cargo.lock') }}
-
     - name: Cache cargo target dir
       uses: actions/cache@v3
       with:
         path: build/cg_clif
         key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
 
-    - name: Prepare dependencies
+    - name: Use sparse cargo registry
       run: |
-        git config --global user.email "user@example.com"
-        git config --global user.name "User"
-        ./y.rs prepare
+        cat >> ~/.cargo/config.toml <<EOF
+        [unstable]
+        sparse-registry = true
+        EOF
 
-    - name: Test
-      run: |
-        # Enable backtraces for easier debugging
-        export RUST_BACKTRACE=1
+    - name: Prepare dependencies
+      run: ./y.rs prepare
 
-        ./scripts/test_bootstrap.sh
+    - name: Test
+      run: ./scripts/test_bootstrap.sh
   rustc_test_suite:
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
 
-    - name: Cache cargo installed crates
-      uses: actions/cache@v3
-      with:
-        path: ~/.cargo/bin
-        key: ${{ runner.os }}-cargo-installed-crates
-
-    - name: Cache cargo registry and index
-      uses: actions/cache@v3
-      with:
-        path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-        key: ${{ runner.os }}-cargo-registry-and-index-${{ hashFiles('**/Cargo.lock') }}
-
     - name: Cache cargo target dir
       uses: actions/cache@v3
       with:
         path: build/cg_clif
         key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
 
-    - name: Prepare dependencies
+    - name: Use sparse cargo registry
       run: |
-        git config --global user.email "user@example.com"
-        git config --global user.name "User"
-        ./y.rs prepare
+        cat >> ~/.cargo/config.toml <<EOF
+        [unstable]
+        sparse-registry = true
+        EOF
 
-    - name: Test
-      run: |
-        # Enable backtraces for easier debugging
-        export RUST_BACKTRACE=1
+    - name: Prepare dependencies
+      run: ./y.rs prepare
 
-        ./scripts/test_rustc_tests.sh
+    - name: Test
+      run: ./scripts/test_rustc_tests.sh
diff --git a/compiler/rustc_codegen_cranelift/.gitignore b/compiler/rustc_codegen_cranelift/.gitignore
index b443fd58a1b..8012e93f6a9 100644
--- a/compiler/rustc_codegen_cranelift/.gitignore
+++ b/compiler/rustc_codegen_cranelift/.gitignore
@@ -1,4 +1,4 @@
-target
+/target
 **/*.rs.bk
 *.rlib
 *.o
@@ -11,9 +11,6 @@ perf.data.old
 /y.exe
 /y.pdb
 /build
-/build_sysroot/sysroot_src
-/build_sysroot/compiler-builtins
-/build_sysroot/rustc_version
 /dist
 /rust
 /download
diff --git a/compiler/rustc_codegen_cranelift/.vscode/settings.json b/compiler/rustc_codegen_cranelift/.vscode/settings.json
index bc914e37d2b..7c8703cba50 100644
--- a/compiler/rustc_codegen_cranelift/.vscode/settings.json
+++ b/compiler/rustc_codegen_cranelift/.vscode/settings.json
@@ -1,4 +1,6 @@
 {
+    "editor.formatOnSave": true,
+
     // source for rustc_* is not included in the rust-src component; disable the errors about this
     "rust-analyzer.diagnostics.disabled": ["unresolved-extern-crate", "unresolved-macro-call"],
     "rust-analyzer.imports.granularity.enforce": true,
@@ -30,7 +32,7 @@
             ]
         },
         {
-            "sysroot_src": "./build_sysroot/sysroot_src/library",
+            "sysroot_src": "./download/sysroot/sysroot_src/library",
             "crates": [
                 {
                     "root_module": "./example/std_example.rs",
diff --git a/compiler/rustc_codegen_cranelift/Cargo.lock b/compiler/rustc_codegen_cranelift/Cargo.lock
index e4d3e9ca5ae..50249ea1bdb 100644
--- a/compiler/rustc_codegen_cranelift/Cargo.lock
+++ b/compiler/rustc_codegen_cranelift/Cargo.lock
@@ -57,28 +57,28 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "cranelift-bforest"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b62c772976416112fa4484cbd688cb6fb35fd430005c1c586224fc014018abad"
+checksum = "2f3d54eab028f5805ae3b26fd60eca3f3a9cfb76b989d9bab173be3f61356cc3"
 dependencies = [
  "cranelift-entity",
 ]
 
 [[package]]
 name = "cranelift-codegen"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b40ed2dd13c2ac7e24f88a3090c68ad3414eb1d066a95f8f1f7b3b819cb4e46"
+checksum = "2be1d5f2c3cca1efb691844bc1988b89c77291f13f778499a3f3c0cf49c0ed61"
 dependencies = [
  "arrayvec",
  "bumpalo",
  "cranelift-bforest",
  "cranelift-codegen-meta",
  "cranelift-codegen-shared",
- "cranelift-egraph",
  "cranelift-entity",
  "cranelift-isle",
  "gimli",
+ "hashbrown",
  "log",
  "regalloc2",
  "smallvec",
@@ -87,44 +87,30 @@ dependencies = [
 
 [[package]]
 name = "cranelift-codegen-meta"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb927a8f1c27c34ee3759b6b0ffa528d2330405d5cc4511f0cab33fe2279f4b5"
+checksum = "3f9b1b1089750ce4005893af7ee00bb08a2cf1c9779999c0f7164cbc8ad2e0d2"
 dependencies = [
  "cranelift-codegen-shared",
 ]
 
 [[package]]
 name = "cranelift-codegen-shared"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43dfa417b884a9ab488d95fd6b93b25e959321fe7bfd7a0a960ba5d7fb7ab927"
-
-[[package]]
-name = "cranelift-egraph"
-version = "0.90.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0a66b39785efd8513d2cca967ede56d6cc57c8d7986a595c7c47d0c78de8dce"
-dependencies = [
- "cranelift-entity",
- "fxhash",
- "hashbrown",
- "indexmap",
- "log",
- "smallvec",
-]
+checksum = "cc5fbaec51de47297fd7304986fd53c8c0030abbe69728a60d72e1c63559318d"
 
 [[package]]
 name = "cranelift-entity"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0637ffde963cb5d759bc4d454cfa364b6509e6c74cdaa21298add0ed9276f346"
+checksum = "dab984c94593f876090fae92e984bdcc74d9b1acf740ab5f79036001c65cba13"
 
 [[package]]
 name = "cranelift-frontend"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb72b8342685e850cb037350418f62cc4fc55d6c2eb9c7ca01b82f9f1a6f3d56"
+checksum = "6e0cb3102d21a2fe5f3210af608748ddd0cd09825ac12d42dc56ed5ed8725fe0"
 dependencies = [
  "cranelift-codegen",
  "log",
@@ -134,15 +120,15 @@ dependencies = [
 
 [[package]]
 name = "cranelift-isle"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "850579cb9e4b448f7c301f1e6e6cbad99abe3f1f1d878a4994cb66e33c6db8cd"
+checksum = "72101dd1f441d629735143c41e00b3428f9267738176983ef588ff43382af0a0"
 
 [[package]]
 name = "cranelift-jit"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9add822ad66dcbe152b5ab57de10240a2df4505099f2f6c27159acb711890bd4"
+checksum = "6557f8ce44d498777f2495aa58d9692a4a37d6f84aa445750d666cef770b6a5c"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -159,9 +145,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-module"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "406b772626fc2664864cf947f3895a23b619895c7fff635f3622e2d857f4492f"
+checksum = "88807e1c0c47ec02fe433333ccbe56b480425418b1470e333205e11650697d72"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -169,9 +155,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-native"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d0a279e5bcba3e0466c734d8d8eb6bfc1ad29e95c37f3e4955b492b5616335e"
+checksum = "c22b0d9fcbe3fc5a1af9e7021b44ce42b930bcefac446ce22e02e8f9a0d67120"
 dependencies = [
  "cranelift-codegen",
  "libc",
@@ -180,9 +166,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-object"
-version = "0.90.1"
+version = "0.92.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39793c550f0c1d7db96c2fc1324583670c8143befe6edbfbaf1c68aba53be983"
+checksum = "341375758d7c3fedc0b5315f552e6f0feac46baf87c450a15e9455ef47c2b261"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -317,9 +303,9 @@ checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
 
 [[package]]
 name = "regalloc2"
-version = "0.4.2"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91b2eab54204ea0117fe9a060537e0b07a4e72f7c7d182361ecc346cab2240e5"
+checksum = "300d4fbfb40c1c66a78ba3ddd41c1110247cf52f97b87d0f2fc9209bd49b030c"
 dependencies = [
  "fxhash",
  "log",
@@ -347,7 +333,6 @@ dependencies = [
  "cranelift-frontend",
  "cranelift-jit",
  "cranelift-module",
- "cranelift-native",
  "cranelift-object",
  "gimli",
  "indexmap",
@@ -396,9 +381,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasmtime-jit-icache-coherence"
-version = "2.0.1"
+version = "5.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6bbabb309c06cc238ee91b1455b748c45f0bdcab0dda2c2db85b0a1e69fcb66"
+checksum = "08fcba5ebd96da2a9f0747ab6337fe9788adfb3f63fa2c180520d665562d257e"
 dependencies = [
  "cfg-if",
  "libc",
@@ -429,43 +414,57 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "windows-sys"
-version = "0.36.1"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea04155a16a59f9eab786fe12a4a450e75cdb175f9e0d80da1e17db09f55b8d2"
+checksum = "5a3e1820f08b8513f676f7ab6c1f99ff312fb97b553d30ff4dd86f9f15728aa7"
 dependencies = [
+ "windows_aarch64_gnullvm",
  "windows_aarch64_msvc",
  "windows_i686_gnu",
  "windows_i686_msvc",
  "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
  "windows_x86_64_msvc",
 ]
 
 [[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d2aa71f6f0cbe00ae5167d90ef3cfe66527d6f613ca78ac8024c3ccab9a19e"
+
+[[package]]
 name = "windows_aarch64_msvc"
-version = "0.36.1"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9bb8c3fd39ade2d67e9874ac4f3db21f0d710bee00fe7cab16949ec184eeaa47"
+checksum = "dd0f252f5a35cac83d6311b2e795981f5ee6e67eb1f9a7f64eb4500fbc4dcdb4"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.36.1"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "180e6ccf01daf4c426b846dfc66db1fc518f074baa793aa7d9b9aaeffad6a3b6"
+checksum = "fbeae19f6716841636c28d695375df17562ca208b2b7d0dc47635a50ae6c5de7"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.36.1"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2e7917148b2812d1eeafaeb22a97e4813dfa60a3f8f78ebe204bcc88f12f024"
+checksum = "84c12f65daa39dd2babe6e442988fc329d6243fdce47d7d2d155b8d874862246"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.36.1"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf7b1b21b5362cbc318f686150e5bcea75ecedc74dd157d874d754a2ca44b0ed"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4dcd171b8776c41b97521e5da127a2d86ad280114807d0b2ab1e462bc764d9e1"
+checksum = "09d525d2ba30eeb3297665bd434a54297e4170c7f1a44cad4ef58095b4cd2028"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.36.1"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c811ca4a8c853ef420abd8592ba53ddbbac90410fab6903b3e79972a631f7680"
+checksum = "f40009d85759725a34da6d89a94e63d7bdc50a862acf0dbc7c8e488f1edcb6f5"
diff --git a/compiler/rustc_codegen_cranelift/Cargo.toml b/compiler/rustc_codegen_cranelift/Cargo.toml
index 2b216ca072f..34117c2886f 100644
--- a/compiler/rustc_codegen_cranelift/Cargo.toml
+++ b/compiler/rustc_codegen_cranelift/Cargo.toml
@@ -15,12 +15,14 @@ crate-type = ["dylib"]
 
 [dependencies]
 # These have to be in sync with each other
-cranelift-codegen = { version = "0.90.1", features = ["unwind", "all-arch"] }
-cranelift-frontend = "0.90.1"
-cranelift-module = "0.90.1"
-cranelift-native = "0.90.1"
-cranelift-jit = { version = "0.90.1", optional = true }
-cranelift-object = "0.90.1"
+cranelift-codegen = { version = "0.92", features = ["unwind", "all-arch"] }
+cranelift-frontend = { version = "0.92" }
+cranelift-module = { version = "0.92" }
+# NOTE vendored as src/cranelift_native.rs
+# FIXME revert back to the external crate with Cranelift 0.93
+#cranelift-native = { version = "0.92" }
+cranelift-jit = { version = "0.92", optional = true }
+cranelift-object = { version = "0.92" }
 target-lexicon = "0.12.0"
 gimli = { version = "0.26.0", default-features = false, features = ["write"]}
 object = { version = "0.29.0", default-features = false, features = ["std", "read_core", "write", "archive", "coff", "elf", "macho", "pe"] }
diff --git a/compiler/rustc_codegen_cranelift/Readme.md b/compiler/rustc_codegen_cranelift/Readme.md
index 0e9c77244d4..b87a9dc51e8 100644
--- a/compiler/rustc_codegen_cranelift/Readme.md
+++ b/compiler/rustc_codegen_cranelift/Readme.md
@@ -8,9 +8,9 @@ If not please open an issue.
 ## Building and testing
 
 ```bash
-$ git clone https://github.com/bjorn3/rustc_codegen_cranelift.git
+$ git clone https://github.com/bjorn3/rustc_codegen_cranelift
 $ cd rustc_codegen_cranelift
-$ ./y.rs prepare # download and patch sysroot src and install hyperfine for benchmarking
+$ ./y.rs prepare
 $ ./y.rs build
 ```
 
@@ -20,13 +20,12 @@ To run the test suite replace the last command with:
 $ ./test.sh
 ```
 
-This will implicitly build cg_clif too. Both `y.rs build` and `test.sh` accept a `--debug` argument to
-build in debug mode.
+For more docs on how to build and test see [build_system/usage.txt](build_system/usage.txt) or the help message of `./y.rs`.
 
-Alternatively you can download a pre built version from [GHA]. It is listed in the artifacts section
+Alternatively you can download a pre built version from [Github Actions]. It is listed in the artifacts section
 of workflow runs. Unfortunately due to GHA restrictions you need to be logged in to access it.
 
-[GHA]: https://github.com/bjorn3/rustc_codegen_cranelift/actions?query=branch%3Amaster+event%3Apush+is%3Asuccess
+[Github Actions]: https://github.com/bjorn3/rustc_codegen_cranelift/actions?query=branch%3Amaster+event%3Apush+is%3Asuccess
 
 ## Usage
 
@@ -53,7 +52,8 @@ configuration options.
 
 * Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041))
     * On UNIX there is support for invoking an external assembler for `global_asm!` and `asm!`.
-* SIMD ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/171), some basic things work)
+* SIMD ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/171), `std::simd` fully works, `std::arch` is partially supported)
+* Unwinding on panics ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1677), `-Cpanic=abort` is enabled by default)
 
 ## License
 
diff --git a/compiler/rustc_codegen_cranelift/build_sysroot/Cargo.lock b/compiler/rustc_codegen_cranelift/build_sysroot/Cargo.lock
index bba3210536e..24f15fc8521 100644
--- a/compiler/rustc_codegen_cranelift/build_sysroot/Cargo.lock
+++ b/compiler/rustc_codegen_cranelift/build_sysroot/Cargo.lock
@@ -34,9 +34,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.0.77"
+version = "1.0.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9f73505338f7d905b19d18738976aae232eb46b8efc15554ffc56deb5d9ebe4"
+checksum = "a20104e2335ce8a659d6dd92a51a767a0c062599c73b343fd152cb401e828c3d"
 
 [[package]]
 name = "cfg-if"
@@ -50,9 +50,9 @@ dependencies = [
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.85"
+version = "0.1.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13e81c6cd7ab79f51a0c927d22858d61ad12bd0b3865f0b13ece02a4486aeabb"
+checksum = "5dae98c88e576098d7ab13ebcb40cc43e5114b2beafe61a87cda9200649ff205"
 dependencies = [
  "rustc-std-workspace-core",
 ]
@@ -129,9 +129,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.138"
+version = "0.2.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db6d7e329c562c5dfab7a46a2afabc8b987ab9a4834c9d1ca04dc54c1546cef8"
+checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
 dependencies = [
  "rustc-std-workspace-core",
 ]
diff --git a/compiler/rustc_codegen_cranelift/build_system/abi_cafe.rs b/compiler/rustc_codegen_cranelift/build_system/abi_cafe.rs
index a081fdaa1c7..dbee9be04ee 100644
--- a/compiler/rustc_codegen_cranelift/build_system/abi_cafe.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/abi_cafe.rs
@@ -1,7 +1,6 @@
 use std::path::Path;
 
 use super::build_sysroot;
-use super::config;
 use super::path::Dirs;
 use super::prepare::GitRepo;
 use super::utils::{spawn_and_wait, CargoProject, Compiler};
@@ -10,41 +9,31 @@ use super::SysrootKind;
 pub(crate) static ABI_CAFE_REPO: GitRepo =
     GitRepo::github("Gankra", "abi-cafe", "4c6dc8c9c687e2b3a760ff2176ce236872b37212", "abi-cafe");
 
-static ABI_CAFE: CargoProject = CargoProject::new(&ABI_CAFE_REPO.source_dir(), "abi_cafe");
+pub(crate) static ABI_CAFE: CargoProject =
+    CargoProject::new(&ABI_CAFE_REPO.source_dir(), "abi_cafe");
 
 pub(crate) fn run(
     channel: &str,
     sysroot_kind: SysrootKind,
     dirs: &Dirs,
     cg_clif_dylib: &Path,
-    host_triple: &str,
-    target_triple: &str,
+    bootstrap_host_compiler: &Compiler,
 ) {
-    if !config::get_bool("testsuite.abi-cafe") {
-        eprintln!("[SKIP] abi-cafe");
-        return;
-    }
-
-    if host_triple != target_triple {
-        eprintln!("[SKIP] abi-cafe (cross-compilation not supported)");
-        return;
-    }
-
     eprintln!("Building sysroot for abi-cafe");
     build_sysroot::build_sysroot(
         dirs,
         channel,
         sysroot_kind,
         cg_clif_dylib,
-        host_triple,
-        target_triple,
+        bootstrap_host_compiler,
+        bootstrap_host_compiler.triple.clone(),
     );
 
     eprintln!("Running abi-cafe");
 
     let pairs = ["rustc_calls_cgclif", "cgclif_calls_rustc", "cgclif_calls_cc", "cc_calls_cgclif"];
 
-    let mut cmd = ABI_CAFE.run(&Compiler::host(), dirs);
+    let mut cmd = ABI_CAFE.run(bootstrap_host_compiler, dirs);
     cmd.arg("--");
     cmd.arg("--pairs");
     cmd.args(pairs);
diff --git a/compiler/rustc_codegen_cranelift/build_system/bench.rs b/compiler/rustc_codegen_cranelift/build_system/bench.rs
new file mode 100644
index 00000000000..01d44dafbdd
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/build_system/bench.rs
@@ -0,0 +1,97 @@
+use std::env;
+use std::fs;
+use std::path::Path;
+
+use super::path::{Dirs, RelPath};
+use super::prepare::GitRepo;
+use super::rustc_info::get_file_name;
+use super::utils::{hyperfine_command, is_ci, spawn_and_wait, CargoProject, Compiler};
+
+pub(crate) static SIMPLE_RAYTRACER_REPO: GitRepo = GitRepo::github(
+    "ebobby",
+    "simple-raytracer",
+    "804a7a21b9e673a482797aa289a18ed480e4d813",
+    "<none>",
+);
+
+// Use a separate target dir for the initial LLVM build to reduce unnecessary recompiles
+pub(crate) static SIMPLE_RAYTRACER_LLVM: CargoProject =
+    CargoProject::new(&SIMPLE_RAYTRACER_REPO.source_dir(), "simple_raytracer_llvm");
+
+pub(crate) static SIMPLE_RAYTRACER: CargoProject =
+    CargoProject::new(&SIMPLE_RAYTRACER_REPO.source_dir(), "simple_raytracer");
+
+pub(crate) fn benchmark(dirs: &Dirs, bootstrap_host_compiler: &Compiler) {
+    benchmark_simple_raytracer(dirs, bootstrap_host_compiler);
+}
+
+fn benchmark_simple_raytracer(dirs: &Dirs, bootstrap_host_compiler: &Compiler) {
+    if std::process::Command::new("hyperfine").output().is_err() {
+        eprintln!("Hyperfine not installed");
+        eprintln!("Hint: Try `cargo install hyperfine` to install hyperfine");
+        std::process::exit(1);
+    }
+
+    eprintln!("[LLVM BUILD] simple-raytracer");
+    let build_cmd = SIMPLE_RAYTRACER_LLVM.build(bootstrap_host_compiler, dirs);
+    spawn_and_wait(build_cmd);
+    fs::copy(
+        SIMPLE_RAYTRACER_LLVM
+            .target_dir(dirs)
+            .join(&bootstrap_host_compiler.triple)
+            .join("debug")
+            .join(get_file_name("main", "bin")),
+        RelPath::BUILD.to_path(dirs).join(get_file_name("raytracer_cg_llvm", "bin")),
+    )
+    .unwrap();
+
+    let run_runs = env::var("RUN_RUNS")
+        .unwrap_or(if is_ci() { "2" } else { "10" }.to_string())
+        .parse()
+        .unwrap();
+
+    eprintln!("[BENCH COMPILE] ebobby/simple-raytracer");
+    let cargo_clif =
+        RelPath::DIST.to_path(dirs).join(get_file_name("cargo_clif", "bin").replace('_', "-"));
+    let manifest_path = SIMPLE_RAYTRACER.manifest_path(dirs);
+    let target_dir = SIMPLE_RAYTRACER.target_dir(dirs);
+
+    let clean_cmd = format!(
+        "cargo clean --manifest-path {manifest_path} --target-dir {target_dir}",
+        manifest_path = manifest_path.display(),
+        target_dir = target_dir.display(),
+    );
+    let llvm_build_cmd = format!(
+        "cargo build --manifest-path {manifest_path} --target-dir {target_dir}",
+        manifest_path = manifest_path.display(),
+        target_dir = target_dir.display(),
+    );
+    let clif_build_cmd = format!(
+        "{cargo_clif} build --manifest-path {manifest_path} --target-dir {target_dir}",
+        cargo_clif = cargo_clif.display(),
+        manifest_path = manifest_path.display(),
+        target_dir = target_dir.display(),
+    );
+
+    let bench_compile =
+        hyperfine_command(1, run_runs, Some(&clean_cmd), &llvm_build_cmd, &clif_build_cmd);
+
+    spawn_and_wait(bench_compile);
+
+    eprintln!("[BENCH RUN] ebobby/simple-raytracer");
+    fs::copy(
+        target_dir.join("debug").join(get_file_name("main", "bin")),
+        RelPath::BUILD.to_path(dirs).join(get_file_name("raytracer_cg_clif", "bin")),
+    )
+    .unwrap();
+
+    let mut bench_run = hyperfine_command(
+        0,
+        run_runs,
+        None,
+        Path::new(".").join(get_file_name("raytracer_cg_llvm", "bin")).to_str().unwrap(),
+        Path::new(".").join(get_file_name("raytracer_cg_clif", "bin")).to_str().unwrap(),
+    );
+    bench_run.current_dir(RelPath::BUILD.to_path(dirs));
+    spawn_and_wait(bench_run);
+}
diff --git a/compiler/rustc_codegen_cranelift/build_system/build_backend.rs b/compiler/rustc_codegen_cranelift/build_system/build_backend.rs
index fde8ef424cc..514404305a3 100644
--- a/compiler/rustc_codegen_cranelift/build_system/build_backend.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/build_backend.rs
@@ -5,15 +5,15 @@ use super::path::{Dirs, RelPath};
 use super::rustc_info::get_file_name;
 use super::utils::{is_ci, CargoProject, Compiler};
 
-static CG_CLIF: CargoProject = CargoProject::new(&RelPath::SOURCE, "cg_clif");
+pub(crate) static CG_CLIF: CargoProject = CargoProject::new(&RelPath::SOURCE, "cg_clif");
 
 pub(crate) fn build_backend(
     dirs: &Dirs,
     channel: &str,
-    host_triple: &str,
+    bootstrap_host_compiler: &Compiler,
     use_unstable_features: bool,
 ) -> PathBuf {
-    let mut cmd = CG_CLIF.build(&Compiler::host(), dirs);
+    let mut cmd = CG_CLIF.build(&bootstrap_host_compiler, dirs);
 
     cmd.env("CARGO_BUILD_INCREMENTAL", "true"); // Force incr comp even in release mode
 
@@ -25,6 +25,8 @@ pub(crate) fn build_backend(
 
         // Disabling incr comp reduces cache size and incr comp doesn't save as much on CI anyway
         cmd.env("CARGO_BUILD_INCREMENTAL", "false");
+
+        cmd.env("CARGO_PROFILE_RELEASE_DEBUG_ASSERTIONS", "true");
     }
 
     if use_unstable_features {
@@ -46,7 +48,7 @@ pub(crate) fn build_backend(
 
     CG_CLIF
         .target_dir(dirs)
-        .join(host_triple)
+        .join(&bootstrap_host_compiler.triple)
         .join(channel)
         .join(get_file_name("rustc_codegen_cranelift", "dylib"))
 }
diff --git a/compiler/rustc_codegen_cranelift/build_system/build_sysroot.rs b/compiler/rustc_codegen_cranelift/build_system/build_sysroot.rs
index cbbf09b9b97..bd04fdbe304 100644
--- a/compiler/rustc_codegen_cranelift/build_system/build_sysroot.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/build_sysroot.rs
@@ -1,31 +1,32 @@
 use std::fs;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::process::{self, Command};
 
 use super::path::{Dirs, RelPath};
-use super::rustc_info::{get_file_name, get_rustc_version, get_wrapper_file_name};
-use super::utils::{spawn_and_wait, try_hard_link, CargoProject, Compiler};
+use super::rustc_info::{get_file_name, get_rustc_version, get_toolchain_name};
+use super::utils::{remove_dir_if_exists, spawn_and_wait, try_hard_link, CargoProject, Compiler};
 use super::SysrootKind;
 
 static DIST_DIR: RelPath = RelPath::DIST;
 static BIN_DIR: RelPath = RelPath::DIST.join("bin");
 static LIB_DIR: RelPath = RelPath::DIST.join("lib");
-static RUSTLIB_DIR: RelPath = LIB_DIR.join("rustlib");
 
 pub(crate) fn build_sysroot(
     dirs: &Dirs,
     channel: &str,
     sysroot_kind: SysrootKind,
     cg_clif_dylib_src: &Path,
-    host_triple: &str,
-    target_triple: &str,
-) {
+    bootstrap_host_compiler: &Compiler,
+    target_triple: String,
+) -> Compiler {
     eprintln!("[BUILD] sysroot {:?}", sysroot_kind);
 
     DIST_DIR.ensure_fresh(dirs);
     BIN_DIR.ensure_exists(dirs);
     LIB_DIR.ensure_exists(dirs);
 
+    let is_native = bootstrap_host_compiler.triple == target_triple;
+
     // Copy the backend
     let cg_clif_dylib_path = if cfg!(windows) {
         // Windows doesn't have rpath support, so the cg_clif dylib needs to be next to the
@@ -35,129 +36,169 @@ pub(crate) fn build_sysroot(
         LIB_DIR
     }
     .to_path(dirs)
-    .join(get_file_name("rustc_codegen_cranelift", "dylib"));
+    .join(cg_clif_dylib_src.file_name().unwrap());
     try_hard_link(cg_clif_dylib_src, &cg_clif_dylib_path);
 
     // Build and copy rustc and cargo wrappers
+    let wrapper_base_name = get_file_name("____", "bin");
+    let toolchain_name = get_toolchain_name();
     for wrapper in ["rustc-clif", "rustdoc-clif", "cargo-clif"] {
-        let wrapper_name = get_wrapper_file_name(wrapper, "bin");
+        let wrapper_name = wrapper_base_name.replace("____", wrapper);
 
-        let mut build_cargo_wrapper_cmd = Command::new("rustc");
+        let mut build_cargo_wrapper_cmd = Command::new(&bootstrap_host_compiler.rustc);
         build_cargo_wrapper_cmd
+            .env("TOOLCHAIN_NAME", toolchain_name.clone())
             .arg(RelPath::SCRIPTS.to_path(dirs).join(&format!("{wrapper}.rs")))
             .arg("-o")
             .arg(DIST_DIR.to_path(dirs).join(wrapper_name))
-            .arg("-g");
+            .arg("-Cstrip=debuginfo");
         spawn_and_wait(build_cargo_wrapper_cmd);
     }
 
-    let default_sysroot = super::rustc_info::get_default_sysroot();
+    let host = build_sysroot_for_triple(
+        dirs,
+        channel,
+        bootstrap_host_compiler.clone(),
+        &cg_clif_dylib_path,
+        sysroot_kind,
+    );
+    host.install_into_sysroot(&DIST_DIR.to_path(dirs));
 
-    let host_rustlib_lib = RUSTLIB_DIR.to_path(dirs).join(host_triple).join("lib");
-    let target_rustlib_lib = RUSTLIB_DIR.to_path(dirs).join(target_triple).join("lib");
-    fs::create_dir_all(&host_rustlib_lib).unwrap();
-    fs::create_dir_all(&target_rustlib_lib).unwrap();
+    if !is_native {
+        build_sysroot_for_triple(
+            dirs,
+            channel,
+            {
+                let mut bootstrap_target_compiler = bootstrap_host_compiler.clone();
+                bootstrap_target_compiler.triple = target_triple.clone();
+                bootstrap_target_compiler.set_cross_linker_and_runner();
+                bootstrap_target_compiler
+            },
+            &cg_clif_dylib_path,
+            sysroot_kind,
+        )
+        .install_into_sysroot(&DIST_DIR.to_path(dirs));
+    }
 
-    if target_triple == "x86_64-pc-windows-gnu" {
-        if !default_sysroot.join("lib").join("rustlib").join(target_triple).join("lib").exists() {
-            eprintln!(
-                "The x86_64-pc-windows-gnu target needs to be installed first before it is possible \
-                to compile a sysroot for it.",
-            );
-            process::exit(1);
+    // Copy std for the host to the lib dir. This is necessary for the jit mode to find
+    // libstd.
+    for lib in host.libs {
+        let filename = lib.file_name().unwrap().to_str().unwrap();
+        if filename.contains("std-") && !filename.contains(".rlib") {
+            try_hard_link(&lib, LIB_DIR.to_path(dirs).join(lib.file_name().unwrap()));
         }
-        for file in fs::read_dir(
-            default_sysroot.join("lib").join("rustlib").join(target_triple).join("lib"),
-        )
-        .unwrap()
-        {
-            let file = file.unwrap().path();
-            if file.extension().map_or(true, |ext| ext.to_str().unwrap() != "o") {
-                continue; // only copy object files
-            }
-            try_hard_link(&file, target_rustlib_lib.join(file.file_name().unwrap()));
+    }
+
+    let mut target_compiler = {
+        let dirs: &Dirs = &dirs;
+        let rustc_clif =
+            RelPath::DIST.to_path(&dirs).join(wrapper_base_name.replace("____", "rustc-clif"));
+        let rustdoc_clif =
+            RelPath::DIST.to_path(&dirs).join(wrapper_base_name.replace("____", "rustdoc-clif"));
+
+        Compiler {
+            cargo: bootstrap_host_compiler.cargo.clone(),
+            rustc: rustc_clif.clone(),
+            rustdoc: rustdoc_clif.clone(),
+            rustflags: String::new(),
+            rustdocflags: String::new(),
+            triple: target_triple,
+            runner: vec![],
         }
+    };
+    if !is_native {
+        target_compiler.set_cross_linker_and_runner();
     }
+    target_compiler
+}
 
-    match sysroot_kind {
-        SysrootKind::None => {} // Nothing to do
-        SysrootKind::Llvm => {
-            for file in fs::read_dir(
-                default_sysroot.join("lib").join("rustlib").join(host_triple).join("lib"),
-            )
-            .unwrap()
-            {
-                let file = file.unwrap().path();
-                let file_name_str = file.file_name().unwrap().to_str().unwrap();
-                if (file_name_str.contains("rustc_")
-                    && !file_name_str.contains("rustc_std_workspace_")
-                    && !file_name_str.contains("rustc_demangle"))
-                    || file_name_str.contains("chalk")
-                    || file_name_str.contains("tracing")
-                    || file_name_str.contains("regex")
-                {
-                    // These are large crates that are part of the rustc-dev component and are not
-                    // necessary to run regular programs.
-                    continue;
-                }
-                try_hard_link(&file, host_rustlib_lib.join(file.file_name().unwrap()));
-            }
+struct SysrootTarget {
+    triple: String,
+    libs: Vec<PathBuf>,
+}
 
-            if target_triple != host_triple {
-                for file in fs::read_dir(
-                    default_sysroot.join("lib").join("rustlib").join(target_triple).join("lib"),
-                )
-                .unwrap()
-                {
-                    let file = file.unwrap().path();
-                    try_hard_link(&file, target_rustlib_lib.join(file.file_name().unwrap()));
-                }
-            }
+impl SysrootTarget {
+    fn install_into_sysroot(&self, sysroot: &Path) {
+        if self.libs.is_empty() {
+            return;
         }
-        SysrootKind::Clif => {
-            build_clif_sysroot_for_triple(dirs, channel, host_triple, &cg_clif_dylib_path, None);
-
-            if host_triple != target_triple {
-                // When cross-compiling it is often necessary to manually pick the right linker
-                let linker = match target_triple {
-                    "aarch64-unknown-linux-gnu" => Some("aarch64-linux-gnu-gcc"),
-                    "s390x-unknown-linux-gnu" => Some("s390x-linux-gnu-gcc"),
-                    _ => None,
-                };
-                build_clif_sysroot_for_triple(
-                    dirs,
-                    channel,
-                    target_triple,
-                    &cg_clif_dylib_path,
-                    linker,
-                );
-            }
 
-            // Copy std for the host to the lib dir. This is necessary for the jit mode to find
-            // libstd.
-            for file in fs::read_dir(host_rustlib_lib).unwrap() {
-                let file = file.unwrap().path();
-                let filename = file.file_name().unwrap().to_str().unwrap();
-                if filename.contains("std-") && !filename.contains(".rlib") {
-                    try_hard_link(&file, LIB_DIR.to_path(dirs).join(file.file_name().unwrap()));
-                }
-            }
+        let target_rustlib_lib = sysroot.join("lib").join("rustlib").join(&self.triple).join("lib");
+        fs::create_dir_all(&target_rustlib_lib).unwrap();
+
+        for lib in &self.libs {
+            try_hard_link(lib, target_rustlib_lib.join(lib.file_name().unwrap()));
         }
     }
 }
 
-// FIXME move to download/ or dist/
-pub(crate) static SYSROOT_RUSTC_VERSION: RelPath = RelPath::BUILD_SYSROOT.join("rustc_version");
-pub(crate) static SYSROOT_SRC: RelPath = RelPath::BUILD_SYSROOT.join("sysroot_src");
-static STANDARD_LIBRARY: CargoProject = CargoProject::new(&RelPath::BUILD_SYSROOT, "build_sysroot");
+pub(crate) static ORIG_BUILD_SYSROOT: RelPath = RelPath::SOURCE.join("build_sysroot");
+pub(crate) static BUILD_SYSROOT: RelPath = RelPath::DOWNLOAD.join("sysroot");
+pub(crate) static SYSROOT_RUSTC_VERSION: RelPath = BUILD_SYSROOT.join("rustc_version");
+pub(crate) static SYSROOT_SRC: RelPath = BUILD_SYSROOT.join("sysroot_src");
+pub(crate) static STANDARD_LIBRARY: CargoProject =
+    CargoProject::new(&BUILD_SYSROOT, "build_sysroot");
+pub(crate) static RTSTARTUP_SYSROOT: RelPath = RelPath::BUILD.join("rtstartup");
 
+#[must_use]
+fn build_sysroot_for_triple(
+    dirs: &Dirs,
+    channel: &str,
+    compiler: Compiler,
+    cg_clif_dylib_path: &Path,
+    sysroot_kind: SysrootKind,
+) -> SysrootTarget {
+    match sysroot_kind {
+        SysrootKind::None => build_rtstartup(dirs, &compiler)
+            .unwrap_or(SysrootTarget { triple: compiler.triple, libs: vec![] }),
+        SysrootKind::Llvm => build_llvm_sysroot_for_triple(compiler),
+        SysrootKind::Clif => {
+            build_clif_sysroot_for_triple(dirs, channel, compiler, &cg_clif_dylib_path)
+        }
+    }
+}
+
+#[must_use]
+fn build_llvm_sysroot_for_triple(compiler: Compiler) -> SysrootTarget {
+    let default_sysroot = super::rustc_info::get_default_sysroot(&compiler.rustc);
+
+    let mut target_libs = SysrootTarget { triple: compiler.triple, libs: vec![] };
+
+    for entry in fs::read_dir(
+        default_sysroot.join("lib").join("rustlib").join(&target_libs.triple).join("lib"),
+    )
+    .unwrap()
+    {
+        let entry = entry.unwrap();
+        if entry.file_type().unwrap().is_dir() {
+            continue;
+        }
+        let file = entry.path();
+        let file_name_str = file.file_name().unwrap().to_str().unwrap();
+        if (file_name_str.contains("rustc_")
+            && !file_name_str.contains("rustc_std_workspace_")
+            && !file_name_str.contains("rustc_demangle"))
+            || file_name_str.contains("chalk")
+            || file_name_str.contains("tracing")
+            || file_name_str.contains("regex")
+        {
+            // These are large crates that are part of the rustc-dev component and are not
+            // necessary to run regular programs.
+            continue;
+        }
+        target_libs.libs.push(file);
+    }
+
+    target_libs
+}
+
+#[must_use]
 fn build_clif_sysroot_for_triple(
     dirs: &Dirs,
     channel: &str,
-    triple: &str,
+    mut compiler: Compiler,
     cg_clif_dylib_path: &Path,
-    linker: Option<&str>,
-) {
+) -> SysrootTarget {
     match fs::read_to_string(SYSROOT_RUSTC_VERSION.to_path(dirs)) {
         Err(e) => {
             eprintln!("Failed to get rustc version for patched sysroot source: {}", e);
@@ -165,7 +206,7 @@ fn build_clif_sysroot_for_triple(
             process::exit(1);
         }
         Ok(source_version) => {
-            let rustc_version = get_rustc_version();
+            let rustc_version = get_rustc_version(&compiler.rustc);
             if source_version != rustc_version {
                 eprintln!("The patched sysroot source is outdated");
                 eprintln!("Source version: {}", source_version.trim());
@@ -176,29 +217,32 @@ fn build_clif_sysroot_for_triple(
         }
     }
 
-    let build_dir = STANDARD_LIBRARY.target_dir(dirs).join(triple).join(channel);
+    let mut target_libs = SysrootTarget { triple: compiler.triple.clone(), libs: vec![] };
+
+    if let Some(rtstartup_target_libs) = build_rtstartup(dirs, &compiler) {
+        rtstartup_target_libs.install_into_sysroot(&RTSTARTUP_SYSROOT.to_path(dirs));
+
+        target_libs.libs.extend(rtstartup_target_libs.libs);
+    }
+
+    let build_dir = STANDARD_LIBRARY.target_dir(dirs).join(&compiler.triple).join(channel);
 
     if !super::config::get_bool("keep_sysroot") {
         // Cleanup the deps dir, but keep build scripts and the incremental cache for faster
         // recompilation as they are not affected by changes in cg_clif.
-        if build_dir.join("deps").exists() {
-            fs::remove_dir_all(build_dir.join("deps")).unwrap();
-        }
+        remove_dir_if_exists(&build_dir.join("deps"));
     }
 
     // Build sysroot
-    let mut rustflags = "-Zforce-unstable-if-unmarked -Cpanic=abort".to_string();
+    let mut rustflags = " -Zforce-unstable-if-unmarked -Cpanic=abort".to_string();
     rustflags.push_str(&format!(" -Zcodegen-backend={}", cg_clif_dylib_path.to_str().unwrap()));
-    rustflags.push_str(&format!(" --sysroot={}", DIST_DIR.to_path(dirs).to_str().unwrap()));
+    // Necessary for MinGW to find rsbegin.o and rsend.o
+    rustflags
+        .push_str(&format!(" --sysroot={}", RTSTARTUP_SYSROOT.to_path(dirs).to_str().unwrap()));
     if channel == "release" {
         rustflags.push_str(" -Zmir-opt-level=3");
     }
-    if let Some(linker) = linker {
-        use std::fmt::Write;
-        write!(rustflags, " -Clinker={}", linker).unwrap();
-    }
-    let mut compiler = Compiler::with_triple(triple.to_owned());
-    compiler.rustflags = rustflags;
+    compiler.rustflags += &rustflags;
     let mut build_cmd = STANDARD_LIBRARY.build(&compiler, dirs);
     if channel == "release" {
         build_cmd.arg("--release");
@@ -206,7 +250,6 @@ fn build_clif_sysroot_for_triple(
     build_cmd.env("__CARGO_DEFAULT_LIB_METADATA", "cg_clif");
     spawn_and_wait(build_cmd);
 
-    // Copy all relevant files to the sysroot
     for entry in fs::read_dir(build_dir.join("deps")).unwrap() {
         let entry = entry.unwrap();
         if let Some(ext) = entry.path().extension() {
@@ -216,9 +259,35 @@ fn build_clif_sysroot_for_triple(
         } else {
             continue;
         };
-        try_hard_link(
-            entry.path(),
-            RUSTLIB_DIR.to_path(dirs).join(triple).join("lib").join(entry.file_name()),
-        );
+        target_libs.libs.push(entry.path());
+    }
+
+    target_libs
+}
+
+fn build_rtstartup(dirs: &Dirs, compiler: &Compiler) -> Option<SysrootTarget> {
+    if !compiler.triple.ends_with("windows-gnu") {
+        return None;
     }
+
+    RTSTARTUP_SYSROOT.ensure_fresh(dirs);
+
+    let rtstartup_src = SYSROOT_SRC.to_path(dirs).join("library").join("rtstartup");
+    let mut target_libs = SysrootTarget { triple: compiler.triple.clone(), libs: vec![] };
+
+    for file in ["rsbegin", "rsend"] {
+        let obj = RTSTARTUP_SYSROOT.to_path(dirs).join(format!("{file}.o"));
+        let mut build_rtstartup_cmd = Command::new(&compiler.rustc);
+        build_rtstartup_cmd
+            .arg("--target")
+            .arg(&compiler.triple)
+            .arg("--emit=obj")
+            .arg("-o")
+            .arg(&obj)
+            .arg(rtstartup_src.join(format!("{file}.rs")));
+        spawn_and_wait(build_rtstartup_cmd);
+        target_libs.libs.push(obj.clone());
+    }
+
+    Some(target_libs)
 }
diff --git a/compiler/rustc_codegen_cranelift/build_system/mod.rs b/compiler/rustc_codegen_cranelift/build_system/mod.rs
index 1afc9a55c73..8dcbe8de189 100644
--- a/compiler/rustc_codegen_cranelift/build_system/mod.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/mod.rs
@@ -2,9 +2,10 @@ use std::env;
 use std::path::PathBuf;
 use std::process;
 
-use self::utils::is_ci;
+use self::utils::{is_ci, Compiler};
 
 mod abi_cafe;
+mod bench;
 mod build_backend;
 mod build_sysroot;
 mod config;
@@ -14,31 +15,8 @@ mod rustc_info;
 mod tests;
 mod utils;
 
-const USAGE: &str = r#"The build system of cg_clif.
-
-USAGE:
-    ./y.rs prepare [--out-dir DIR]
-    ./y.rs build [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
-    ./y.rs test [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
-
-OPTIONS:
-    --sysroot none|clif|llvm
-            Which sysroot libraries to use:
-            `none` will not include any standard library in the sysroot.
-            `clif` will build the standard library using Cranelift.
-            `llvm` will use the pre-compiled standard library of rustc which is compiled with LLVM.
-
-    --out-dir DIR
-            Specify the directory in which the download, build and dist directories are stored.
-            By default this is the working directory.
-
-    --no-unstable-features
-            fSome features are not yet ready for production usage. This option will disable these
-            features. This includes the JIT mode and inline assembly support.
-"#;
-
 fn usage() {
-    eprintln!("{USAGE}");
+    eprintln!("{}", include_str!("usage.txt"));
 }
 
 macro_rules! arg_error {
@@ -54,6 +32,8 @@ enum Command {
     Prepare,
     Build,
     Test,
+    AbiCafe,
+    Bench,
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -64,12 +44,17 @@ pub(crate) enum SysrootKind {
 }
 
 pub fn main() {
-    env::set_var("CG_CLIF_DISPLAY_CG_TIME", "1");
+    if env::var("RUST_BACKTRACE").is_err() {
+        env::set_var("RUST_BACKTRACE", "1");
+    }
     env::set_var("CG_CLIF_DISABLE_INCR_CACHE", "1");
 
     if is_ci() {
         // Disabling incr comp reduces cache size and incr comp doesn't save as much on CI anyway
         env::set_var("CARGO_BUILD_INCREMENTAL", "false");
+
+        // Enable the Cranelift verifier
+        env::set_var("CG_CLIF_ENABLE_VERIFIER", "1");
     }
 
     let mut args = env::args().skip(1);
@@ -77,6 +62,8 @@ pub fn main() {
         Some("prepare") => Command::Prepare,
         Some("build") => Command::Build,
         Some("test") => Command::Test,
+        Some("abi-cafe") => Command::AbiCafe,
+        Some("bench") => Command::Bench,
         Some(flag) if flag.starts_with('-') => arg_error!("Expected command found flag {}", flag),
         Some(command) => arg_error!("Unknown command {}", command),
         None => {
@@ -112,24 +99,16 @@ pub fn main() {
         }
     }
 
-    let host_triple = if let Ok(host_triple) = std::env::var("HOST_TRIPLE") {
-        host_triple
-    } else if let Some(host_triple) = config::get_value("host") {
-        host_triple
-    } else {
-        rustc_info::get_host_triple()
-    };
-    let target_triple = if let Ok(target_triple) = std::env::var("TARGET_TRIPLE") {
-        if target_triple != "" {
-            target_triple
-        } else {
-            host_triple.clone() // Empty target triple can happen on GHA
-        }
-    } else if let Some(target_triple) = config::get_value("target") {
-        target_triple
-    } else {
-        host_triple.clone()
-    };
+    let bootstrap_host_compiler = Compiler::bootstrap_with_triple(
+        std::env::var("HOST_TRIPLE")
+            .ok()
+            .or_else(|| config::get_value("host"))
+            .unwrap_or_else(|| rustc_info::get_host_triple()),
+    );
+    let target_triple = std::env::var("TARGET_TRIPLE")
+        .ok()
+        .or_else(|| config::get_value("target"))
+        .unwrap_or_else(|| bootstrap_host_compiler.triple.clone());
 
     // FIXME allow changing the location of these dirs using cli arguments
     let current_dir = std::env::current_dir().unwrap();
@@ -157,8 +136,15 @@ pub fn main() {
         process::exit(0);
     }
 
-    let cg_clif_dylib =
-        build_backend::build_backend(&dirs, channel, &host_triple, use_unstable_features);
+    env::set_var("RUSTC", "rustc_should_be_set_explicitly");
+    env::set_var("RUSTDOC", "rustdoc_should_be_set_explicitly");
+
+    let cg_clif_dylib = build_backend::build_backend(
+        &dirs,
+        channel,
+        &bootstrap_host_compiler,
+        use_unstable_features,
+    );
     match command {
         Command::Prepare => {
             // Handled above
@@ -169,28 +155,37 @@ pub fn main() {
                 channel,
                 sysroot_kind,
                 &cg_clif_dylib,
-                &host_triple,
-                &target_triple,
+                &bootstrap_host_compiler,
+                target_triple.clone(),
             );
-
-            abi_cafe::run(
+        }
+        Command::AbiCafe => {
+            if bootstrap_host_compiler.triple != target_triple {
+                eprintln!("Abi-cafe doesn't support cross-compilation");
+                process::exit(1);
+            }
+            abi_cafe::run(channel, sysroot_kind, &dirs, &cg_clif_dylib, &bootstrap_host_compiler);
+        }
+        Command::Build => {
+            build_sysroot::build_sysroot(
+                &dirs,
                 channel,
                 sysroot_kind,
-                &dirs,
                 &cg_clif_dylib,
-                &host_triple,
-                &target_triple,
+                &bootstrap_host_compiler,
+                target_triple,
             );
         }
-        Command::Build => {
+        Command::Bench => {
             build_sysroot::build_sysroot(
                 &dirs,
                 channel,
                 sysroot_kind,
                 &cg_clif_dylib,
-                &host_triple,
-                &target_triple,
+                &bootstrap_host_compiler,
+                target_triple,
             );
+            bench::benchmark(&dirs, &bootstrap_host_compiler);
         }
     }
 }
diff --git a/compiler/rustc_codegen_cranelift/build_system/path.rs b/compiler/rustc_codegen_cranelift/build_system/path.rs
index e93981f1d64..3290723005d 100644
--- a/compiler/rustc_codegen_cranelift/build_system/path.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/path.rs
@@ -1,6 +1,8 @@
 use std::fs;
 use std::path::PathBuf;
 
+use super::utils::remove_dir_if_exists;
+
 #[derive(Debug, Clone)]
 pub(crate) struct Dirs {
     pub(crate) source_dir: PathBuf,
@@ -42,7 +44,6 @@ impl RelPath {
     pub(crate) const DIST: RelPath = RelPath::Base(PathBase::Dist);
 
     pub(crate) const SCRIPTS: RelPath = RelPath::SOURCE.join("scripts");
-    pub(crate) const BUILD_SYSROOT: RelPath = RelPath::SOURCE.join("build_sysroot");
     pub(crate) const PATCHES: RelPath = RelPath::SOURCE.join("patches");
 
     pub(crate) const fn join(&'static self, suffix: &'static str) -> RelPath {
@@ -62,9 +63,7 @@ impl RelPath {
 
     pub(crate) fn ensure_fresh(&self, dirs: &Dirs) {
         let path = self.to_path(dirs);
-        if path.exists() {
-            fs::remove_dir_all(&path).unwrap();
-        }
+        remove_dir_if_exists(&path);
         fs::create_dir_all(path).unwrap();
     }
 }
diff --git a/compiler/rustc_codegen_cranelift/build_system/prepare.rs b/compiler/rustc_codegen_cranelift/build_system/prepare.rs
index 8ac67e8f942..f25a81dc234 100644
--- a/compiler/rustc_codegen_cranelift/build_system/prepare.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/prepare.rs
@@ -3,73 +3,55 @@ use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use super::build_sysroot::{SYSROOT_RUSTC_VERSION, SYSROOT_SRC};
+use super::build_sysroot::{BUILD_SYSROOT, ORIG_BUILD_SYSROOT, SYSROOT_RUSTC_VERSION, SYSROOT_SRC};
 use super::path::{Dirs, RelPath};
-use super::rustc_info::{get_file_name, get_rustc_path, get_rustc_version};
-use super::utils::{copy_dir_recursively, spawn_and_wait, Compiler};
+use super::rustc_info::{get_default_sysroot, get_rustc_version};
+use super::utils::{copy_dir_recursively, git_command, retry_spawn_and_wait, spawn_and_wait};
 
 pub(crate) fn prepare(dirs: &Dirs) {
-    if RelPath::DOWNLOAD.to_path(dirs).exists() {
-        std::fs::remove_dir_all(RelPath::DOWNLOAD.to_path(dirs)).unwrap();
-    }
-    std::fs::create_dir_all(RelPath::DOWNLOAD.to_path(dirs)).unwrap();
+    RelPath::DOWNLOAD.ensure_fresh(dirs);
 
-    prepare_sysroot(dirs);
+    spawn_and_wait(super::build_backend::CG_CLIF.fetch("cargo", dirs));
 
-    // FIXME maybe install this only locally?
-    eprintln!("[INSTALL] hyperfine");
-    Command::new("cargo")
-        .arg("install")
-        .arg("hyperfine")
-        .env_remove("CARGO_TARGET_DIR")
-        .spawn()
-        .unwrap()
-        .wait()
-        .unwrap();
+    prepare_sysroot(dirs);
+    spawn_and_wait(super::build_sysroot::STANDARD_LIBRARY.fetch("cargo", dirs));
+    spawn_and_wait(super::tests::LIBCORE_TESTS.fetch("cargo", dirs));
 
     super::abi_cafe::ABI_CAFE_REPO.fetch(dirs);
+    spawn_and_wait(super::abi_cafe::ABI_CAFE.fetch("cargo", dirs));
     super::tests::RAND_REPO.fetch(dirs);
+    spawn_and_wait(super::tests::RAND.fetch("cargo", dirs));
     super::tests::REGEX_REPO.fetch(dirs);
+    spawn_and_wait(super::tests::REGEX.fetch("cargo", dirs));
     super::tests::PORTABLE_SIMD_REPO.fetch(dirs);
-    super::tests::SIMPLE_RAYTRACER_REPO.fetch(dirs);
-
-    eprintln!("[LLVM BUILD] simple-raytracer");
-    let host_compiler = Compiler::host();
-    let build_cmd = super::tests::SIMPLE_RAYTRACER.build(&host_compiler, dirs);
-    spawn_and_wait(build_cmd);
-    fs::copy(
-        super::tests::SIMPLE_RAYTRACER
-            .target_dir(dirs)
-            .join(&host_compiler.triple)
-            .join("debug")
-            .join(get_file_name("main", "bin")),
-        RelPath::BUILD.to_path(dirs).join(get_file_name("raytracer_cg_llvm", "bin")),
-    )
-    .unwrap();
+    spawn_and_wait(super::tests::PORTABLE_SIMD.fetch("cargo", dirs));
+    super::bench::SIMPLE_RAYTRACER_REPO.fetch(dirs);
+    spawn_and_wait(super::bench::SIMPLE_RAYTRACER.fetch("cargo", dirs));
 }
 
 fn prepare_sysroot(dirs: &Dirs) {
-    let rustc_path = get_rustc_path();
-    let sysroot_src_orig = rustc_path.parent().unwrap().join("../lib/rustlib/src/rust");
-    let sysroot_src = SYSROOT_SRC;
-
+    let sysroot_src_orig = get_default_sysroot(Path::new("rustc")).join("lib/rustlib/src/rust");
     assert!(sysroot_src_orig.exists());
 
-    sysroot_src.ensure_fresh(dirs);
-    fs::create_dir_all(sysroot_src.to_path(dirs).join("library")).unwrap();
     eprintln!("[COPY] sysroot src");
+
+    // FIXME ensure builds error out or update the copy if any of the files copied here change
+    BUILD_SYSROOT.ensure_fresh(dirs);
+    copy_dir_recursively(&ORIG_BUILD_SYSROOT.to_path(dirs), &BUILD_SYSROOT.to_path(dirs));
+
+    fs::create_dir_all(SYSROOT_SRC.to_path(dirs).join("library")).unwrap();
     copy_dir_recursively(
         &sysroot_src_orig.join("library"),
-        &sysroot_src.to_path(dirs).join("library"),
+        &SYSROOT_SRC.to_path(dirs).join("library"),
     );
 
-    let rustc_version = get_rustc_version();
+    let rustc_version = get_rustc_version(Path::new("rustc"));
     fs::write(SYSROOT_RUSTC_VERSION.to_path(dirs), &rustc_version).unwrap();
 
     eprintln!("[GIT] init");
-    init_git_repo(&sysroot_src.to_path(dirs));
+    init_git_repo(&SYSROOT_SRC.to_path(dirs));
 
-    apply_patches(dirs, "sysroot", &sysroot_src.to_path(dirs));
+    apply_patches(dirs, "sysroot", &SYSROOT_SRC.to_path(dirs));
 }
 
 pub(crate) struct GitRepo {
@@ -118,14 +100,14 @@ impl GitRepo {
 fn clone_repo(download_dir: &Path, repo: &str, rev: &str) {
     eprintln!("[CLONE] {}", repo);
     // Ignore exit code as the repo may already have been checked out
-    Command::new("git").arg("clone").arg(repo).arg(&download_dir).spawn().unwrap().wait().unwrap();
+    git_command(None, "clone").arg(repo).arg(download_dir).spawn().unwrap().wait().unwrap();
 
-    let mut clean_cmd = Command::new("git");
-    clean_cmd.arg("checkout").arg("--").arg(".").current_dir(&download_dir);
+    let mut clean_cmd = git_command(download_dir, "checkout");
+    clean_cmd.arg("--").arg(".");
     spawn_and_wait(clean_cmd);
 
-    let mut checkout_cmd = Command::new("git");
-    checkout_cmd.arg("checkout").arg("-q").arg(rev).current_dir(download_dir);
+    let mut checkout_cmd = git_command(download_dir, "checkout");
+    checkout_cmd.arg("-q").arg(rev);
     spawn_and_wait(checkout_cmd);
 }
 
@@ -149,8 +131,22 @@ fn clone_repo_shallow_github(dirs: &Dirs, download_dir: &Path, user: &str, repo:
 
     // Download zip archive
     let mut download_cmd = Command::new("curl");
-    download_cmd.arg("--location").arg("--output").arg(&archive_file).arg(archive_url);
-    spawn_and_wait(download_cmd);
+    download_cmd
+        .arg("--max-time")
+        .arg("600")
+        .arg("-y")
+        .arg("30")
+        .arg("-Y")
+        .arg("10")
+        .arg("--connect-timeout")
+        .arg("30")
+        .arg("--continue-at")
+        .arg("-")
+        .arg("--location")
+        .arg("--output")
+        .arg(&archive_file)
+        .arg(archive_url);
+    retry_spawn_and_wait(5, download_cmd);
 
     // Unpack tar archive
     let mut unpack_cmd = Command::new("tar");
@@ -167,25 +163,16 @@ fn clone_repo_shallow_github(dirs: &Dirs, download_dir: &Path, user: &str, repo:
 }
 
 fn init_git_repo(repo_dir: &Path) {
-    let mut git_init_cmd = Command::new("git");
-    git_init_cmd.arg("init").arg("-q").current_dir(repo_dir);
+    let mut git_init_cmd = git_command(repo_dir, "init");
+    git_init_cmd.arg("-q");
     spawn_and_wait(git_init_cmd);
 
-    let mut git_add_cmd = Command::new("git");
-    git_add_cmd.arg("add").arg(".").current_dir(repo_dir);
+    let mut git_add_cmd = git_command(repo_dir, "add");
+    git_add_cmd.arg(".");
     spawn_and_wait(git_add_cmd);
 
-    let mut git_commit_cmd = Command::new("git");
-    git_commit_cmd
-        .arg("-c")
-        .arg("user.name=Dummy")
-        .arg("-c")
-        .arg("user.email=dummy@example.com")
-        .arg("commit")
-        .arg("-m")
-        .arg("Initial commit")
-        .arg("-q")
-        .current_dir(repo_dir);
+    let mut git_commit_cmd = git_command(repo_dir, "commit");
+    git_commit_cmd.arg("-m").arg("Initial commit").arg("-q");
     spawn_and_wait(git_commit_cmd);
 }
 
@@ -220,16 +207,8 @@ fn apply_patches(dirs: &Dirs, crate_name: &str, target_dir: &Path) {
             target_dir.file_name().unwrap(),
             patch.file_name().unwrap()
         );
-        let mut apply_patch_cmd = Command::new("git");
-        apply_patch_cmd
-            .arg("-c")
-            .arg("user.name=Dummy")
-            .arg("-c")
-            .arg("user.email=dummy@example.com")
-            .arg("am")
-            .arg(patch)
-            .arg("-q")
-            .current_dir(target_dir);
+        let mut apply_patch_cmd = git_command(target_dir, "am");
+        apply_patch_cmd.arg(patch).arg("-q");
         spawn_and_wait(apply_patch_cmd);
     }
 }
diff --git a/compiler/rustc_codegen_cranelift/build_system/rustc_info.rs b/compiler/rustc_codegen_cranelift/build_system/rustc_info.rs
index 8e5ab688e13..a70453b4422 100644
--- a/compiler/rustc_codegen_cranelift/build_system/rustc_info.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/rustc_info.rs
@@ -1,9 +1,9 @@
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 
-pub(crate) fn get_rustc_version() -> String {
+pub(crate) fn get_rustc_version(rustc: &Path) -> String {
     let version_info =
-        Command::new("rustc").stderr(Stdio::inherit()).args(&["-V"]).output().unwrap().stdout;
+        Command::new(rustc).stderr(Stdio::inherit()).args(&["-V"]).output().unwrap().stdout;
     String::from_utf8(version_info).unwrap()
 }
 
@@ -23,6 +23,16 @@ pub(crate) fn get_host_triple() -> String {
         .to_owned()
 }
 
+pub(crate) fn get_toolchain_name() -> String {
+    let active_toolchain = Command::new("rustup")
+        .stderr(Stdio::inherit())
+        .args(&["show", "active-toolchain"])
+        .output()
+        .unwrap()
+        .stdout;
+    String::from_utf8(active_toolchain).unwrap().trim().split_once(' ').unwrap().0.to_owned()
+}
+
 pub(crate) fn get_cargo_path() -> PathBuf {
     let cargo_path = Command::new("rustup")
         .stderr(Stdio::inherit())
@@ -53,8 +63,8 @@ pub(crate) fn get_rustdoc_path() -> PathBuf {
     Path::new(String::from_utf8(rustc_path).unwrap().trim()).to_owned()
 }
 
-pub(crate) fn get_default_sysroot() -> PathBuf {
-    let default_sysroot = Command::new("rustc")
+pub(crate) fn get_default_sysroot(rustc: &Path) -> PathBuf {
+    let default_sysroot = Command::new(rustc)
         .stderr(Stdio::inherit())
         .args(&["--print", "sysroot"])
         .output()
@@ -83,12 +93,3 @@ pub(crate) fn get_file_name(crate_name: &str, crate_type: &str) -> String {
     assert!(file_name.contains(crate_name));
     file_name
 }
-
-/// Similar to `get_file_name`, but converts any dashes (`-`) in the `crate_name` to
-/// underscores (`_`). This is specially made for the rustc and cargo wrappers
-/// which have a dash in the name, and that is not allowed in a crate name.
-pub(crate) fn get_wrapper_file_name(crate_name: &str, crate_type: &str) -> String {
-    let crate_name = crate_name.replace('-', "_");
-    let wrapper_name = get_file_name(&crate_name, crate_type);
-    wrapper_name.replace('_', "-")
-}
diff --git a/compiler/rustc_codegen_cranelift/build_system/tests.rs b/compiler/rustc_codegen_cranelift/build_system/tests.rs
index 1c372736ed6..dcfadd73756 100644
--- a/compiler/rustc_codegen_cranelift/build_system/tests.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/tests.rs
@@ -1,11 +1,10 @@
-use super::build_sysroot;
+use super::bench::SIMPLE_RAYTRACER;
+use super::build_sysroot::{self, SYSROOT_SRC};
 use super::config;
 use super::path::{Dirs, RelPath};
 use super::prepare::GitRepo;
-use super::rustc_info::{get_cargo_path, get_wrapper_file_name};
-use super::utils::{
-    hyperfine_command, spawn_and_wait, spawn_and_wait_with_input, CargoProject, Compiler,
-};
+use super::rustc_info::get_host_triple;
+use super::utils::{spawn_and_wait, spawn_and_wait_with_input, CargoProject, Compiler};
 use super::SysrootKind;
 use std::env;
 use std::ffi::OsStr;
@@ -17,256 +16,111 @@ static BUILD_EXAMPLE_OUT_DIR: RelPath = RelPath::BUILD.join("example");
 
 struct TestCase {
     config: &'static str,
-    func: &'static dyn Fn(&TestRunner),
+    cmd: TestCaseCmd,
+}
+
+enum TestCaseCmd {
+    Custom { func: &'static dyn Fn(&TestRunner) },
+    BuildLib { source: &'static str, crate_types: &'static str },
+    BuildBinAndRun { source: &'static str, args: &'static [&'static str] },
+    JitBin { source: &'static str, args: &'static str },
 }
 
 impl TestCase {
-    const fn new(config: &'static str, func: &'static dyn Fn(&TestRunner)) -> Self {
-        Self { config, func }
+    // FIXME reduce usage of custom test case commands
+    const fn custom(config: &'static str, func: &'static dyn Fn(&TestRunner)) -> Self {
+        Self { config, cmd: TestCaseCmd::Custom { func } }
+    }
+
+    const fn build_lib(
+        config: &'static str,
+        source: &'static str,
+        crate_types: &'static str,
+    ) -> Self {
+        Self { config, cmd: TestCaseCmd::BuildLib { source, crate_types } }
+    }
+
+    const fn build_bin_and_run(
+        config: &'static str,
+        source: &'static str,
+        args: &'static [&'static str],
+    ) -> Self {
+        Self { config, cmd: TestCaseCmd::BuildBinAndRun { source, args } }
+    }
+
+    const fn jit_bin(config: &'static str, source: &'static str, args: &'static str) -> Self {
+        Self { config, cmd: TestCaseCmd::JitBin { source, args } }
     }
 }
 
 const NO_SYSROOT_SUITE: &[TestCase] = &[
-    TestCase::new("build.mini_core", &|runner| {
-        runner.run_rustc([
-            "example/mini_core.rs",
-            "--crate-name",
-            "mini_core",
-            "--crate-type",
-            "lib,dylib",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-    }),
-    TestCase::new("build.example", &|runner| {
-        runner.run_rustc([
-            "example/example.rs",
-            "--crate-type",
-            "lib",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-    }),
-    TestCase::new("jit.mini_core_hello_world", &|runner| {
-        let mut jit_cmd = runner.rustc_command([
-            "-Zunstable-options",
-            "-Cllvm-args=mode=jit",
-            "-Cprefer-dynamic",
-            "example/mini_core_hello_world.rs",
-            "--cfg",
-            "jit",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        jit_cmd.env("CG_CLIF_JIT_ARGS", "abc bcd");
-        spawn_and_wait(jit_cmd);
-
-        eprintln!("[JIT-lazy] mini_core_hello_world");
-        let mut jit_cmd = runner.rustc_command([
-            "-Zunstable-options",
-            "-Cllvm-args=mode=jit-lazy",
-            "-Cprefer-dynamic",
-            "example/mini_core_hello_world.rs",
-            "--cfg",
-            "jit",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        jit_cmd.env("CG_CLIF_JIT_ARGS", "abc bcd");
-        spawn_and_wait(jit_cmd);
-    }),
-    TestCase::new("aot.mini_core_hello_world", &|runner| {
-        runner.run_rustc([
-            "example/mini_core_hello_world.rs",
-            "--crate-name",
-            "mini_core_hello_world",
-            "--crate-type",
-            "bin",
-            "-g",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("mini_core_hello_world", ["abc", "bcd"]);
-    }),
+    TestCase::build_lib("build.mini_core", "example/mini_core.rs", "lib,dylib"),
+    TestCase::build_lib("build.example", "example/example.rs", "lib"),
+    TestCase::jit_bin("jit.mini_core_hello_world", "example/mini_core_hello_world.rs", "abc bcd"),
+    TestCase::build_bin_and_run(
+        "aot.mini_core_hello_world",
+        "example/mini_core_hello_world.rs",
+        &["abc", "bcd"],
+    ),
 ];
 
 const BASE_SYSROOT_SUITE: &[TestCase] = &[
-    TestCase::new("aot.arbitrary_self_types_pointers_and_wrappers", &|runner| {
-        runner.run_rustc([
-            "example/arbitrary_self_types_pointers_and_wrappers.rs",
-            "--crate-name",
-            "arbitrary_self_types_pointers_and_wrappers",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("arbitrary_self_types_pointers_and_wrappers", []);
-    }),
-    TestCase::new("aot.issue_91827_extern_types", &|runner| {
-        runner.run_rustc([
-            "example/issue-91827-extern-types.rs",
-            "--crate-name",
-            "issue_91827_extern_types",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("issue_91827_extern_types", []);
-    }),
-    TestCase::new("build.alloc_system", &|runner| {
-        runner.run_rustc([
-            "example/alloc_system.rs",
-            "--crate-type",
-            "lib",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-    }),
-    TestCase::new("aot.alloc_example", &|runner| {
-        runner.run_rustc([
-            "example/alloc_example.rs",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("alloc_example", []);
-    }),
-    TestCase::new("jit.std_example", &|runner| {
-        runner.run_rustc([
-            "-Zunstable-options",
-            "-Cllvm-args=mode=jit",
-            "-Cprefer-dynamic",
-            "example/std_example.rs",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-
-        eprintln!("[JIT-lazy] std_example");
-        runner.run_rustc([
-            "-Zunstable-options",
-            "-Cllvm-args=mode=jit-lazy",
-            "-Cprefer-dynamic",
-            "example/std_example.rs",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-    }),
-    TestCase::new("aot.std_example", &|runner| {
-        runner.run_rustc([
-            "example/std_example.rs",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("std_example", ["arg"]);
-    }),
-    TestCase::new("aot.dst_field_align", &|runner| {
-        runner.run_rustc([
-            "example/dst-field-align.rs",
-            "--crate-name",
-            "dst_field_align",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("dst_field_align", []);
-    }),
-    TestCase::new("aot.subslice-patterns-const-eval", &|runner| {
-        runner.run_rustc([
-            "example/subslice-patterns-const-eval.rs",
-            "--crate-type",
-            "bin",
-            "-Cpanic=abort",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("subslice-patterns-const-eval", []);
-    }),
-    TestCase::new("aot.track-caller-attribute", &|runner| {
-        runner.run_rustc([
-            "example/track-caller-attribute.rs",
-            "--crate-type",
-            "bin",
-            "-Cpanic=abort",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("track-caller-attribute", []);
-    }),
-    TestCase::new("aot.float-minmax-pass", &|runner| {
-        runner.run_rustc([
-            "example/float-minmax-pass.rs",
-            "--crate-type",
-            "bin",
-            "-Cpanic=abort",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("float-minmax-pass", []);
-    }),
-    TestCase::new("aot.mod_bench", &|runner| {
-        runner.run_rustc([
-            "example/mod_bench.rs",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("mod_bench", []);
-    }),
-    TestCase::new("aot.issue-72793", &|runner| {
-        runner.run_rustc([
-            "example/issue-72793.rs",
-            "--crate-type",
-            "bin",
-            "--target",
-            &runner.target_compiler.triple,
-        ]);
-        runner.run_out_command("issue-72793", []);
-    }),
+    TestCase::build_bin_and_run(
+        "aot.arbitrary_self_types_pointers_and_wrappers",
+        "example/arbitrary_self_types_pointers_and_wrappers.rs",
+        &[],
+    ),
+    TestCase::build_bin_and_run(
+        "aot.issue_91827_extern_types",
+        "example/issue-91827-extern-types.rs",
+        &[],
+    ),
+    TestCase::build_lib("build.alloc_system", "example/alloc_system.rs", "lib"),
+    TestCase::build_bin_and_run("aot.alloc_example", "example/alloc_example.rs", &[]),
+    TestCase::jit_bin("jit.std_example", "example/std_example.rs", ""),
+    TestCase::build_bin_and_run("aot.std_example", "example/std_example.rs", &["arg"]),
+    TestCase::build_bin_and_run("aot.dst_field_align", "example/dst-field-align.rs", &[]),
+    TestCase::build_bin_and_run(
+        "aot.subslice-patterns-const-eval",
+        "example/subslice-patterns-const-eval.rs",
+        &[],
+    ),
+    TestCase::build_bin_and_run(
+        "aot.track-caller-attribute",
+        "example/track-caller-attribute.rs",
+        &[],
+    ),
+    TestCase::build_bin_and_run("aot.float-minmax-pass", "example/float-minmax-pass.rs", &[]),
+    TestCase::build_bin_and_run("aot.mod_bench", "example/mod_bench.rs", &[]),
+    TestCase::build_bin_and_run("aot.issue-72793", "example/issue-72793.rs", &[]),
 ];
 
 pub(crate) static RAND_REPO: GitRepo =
     GitRepo::github("rust-random", "rand", "0f933f9c7176e53b2a3c7952ded484e1783f0bf1", "rand");
 
-static RAND: CargoProject = CargoProject::new(&RAND_REPO.source_dir(), "rand");
+pub(crate) static RAND: CargoProject = CargoProject::new(&RAND_REPO.source_dir(), "rand");
 
 pub(crate) static REGEX_REPO: GitRepo =
     GitRepo::github("rust-lang", "regex", "341f207c1071f7290e3f228c710817c280c8dca1", "regex");
 
-static REGEX: CargoProject = CargoProject::new(&REGEX_REPO.source_dir(), "regex");
+pub(crate) static REGEX: CargoProject = CargoProject::new(&REGEX_REPO.source_dir(), "regex");
 
 pub(crate) static PORTABLE_SIMD_REPO: GitRepo = GitRepo::github(
     "rust-lang",
     "portable-simd",
-    "d5cd4a8112d958bd3a252327e0d069a6363249bd",
+    "582239ac3b32007613df04d7ffa78dc30f4c5645",
     "portable-simd",
 );
 
-static PORTABLE_SIMD: CargoProject =
+pub(crate) static PORTABLE_SIMD: CargoProject =
     CargoProject::new(&PORTABLE_SIMD_REPO.source_dir(), "portable_simd");
 
-pub(crate) static SIMPLE_RAYTRACER_REPO: GitRepo = GitRepo::github(
-    "ebobby",
-    "simple-raytracer",
-    "804a7a21b9e673a482797aa289a18ed480e4d813",
-    "<none>",
-);
-
-pub(crate) static SIMPLE_RAYTRACER: CargoProject =
-    CargoProject::new(&SIMPLE_RAYTRACER_REPO.source_dir(), "simple_raytracer");
-
-static LIBCORE_TESTS: CargoProject =
-    CargoProject::new(&RelPath::BUILD_SYSROOT.join("sysroot_src/library/core/tests"), "core_tests");
+pub(crate) static LIBCORE_TESTS: CargoProject =
+    CargoProject::new(&SYSROOT_SRC.join("library/core/tests"), "core_tests");
 
 const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
-    TestCase::new("test.rust-random/rand", &|runner| {
-        spawn_and_wait(RAND.clean(&runner.target_compiler.cargo, &runner.dirs));
+    TestCase::custom("test.rust-random/rand", &|runner| {
+        RAND.clean(&runner.dirs);
 
         if runner.is_native {
             eprintln!("[TEST] rust-random/rand");
@@ -280,60 +134,12 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
             spawn_and_wait(build_cmd);
         }
     }),
-    TestCase::new("bench.simple-raytracer", &|runner| {
-        let run_runs = env::var("RUN_RUNS").unwrap_or("10".to_string()).parse().unwrap();
-
-        if runner.is_native {
-            eprintln!("[BENCH COMPILE] ebobby/simple-raytracer");
-            let cargo_clif = RelPath::DIST
-                .to_path(&runner.dirs)
-                .join(get_wrapper_file_name("cargo-clif", "bin"));
-            let manifest_path = SIMPLE_RAYTRACER.manifest_path(&runner.dirs);
-            let target_dir = SIMPLE_RAYTRACER.target_dir(&runner.dirs);
-
-            let clean_cmd = format!(
-                "cargo clean --manifest-path {manifest_path} --target-dir {target_dir}",
-                manifest_path = manifest_path.display(),
-                target_dir = target_dir.display(),
-            );
-            let llvm_build_cmd = format!(
-                "cargo build --manifest-path {manifest_path} --target-dir {target_dir}",
-                manifest_path = manifest_path.display(),
-                target_dir = target_dir.display(),
-            );
-            let clif_build_cmd = format!(
-                "{cargo_clif} build --manifest-path {manifest_path} --target-dir {target_dir}",
-                cargo_clif = cargo_clif.display(),
-                manifest_path = manifest_path.display(),
-                target_dir = target_dir.display(),
-            );
-
-            let bench_compile =
-                hyperfine_command(1, run_runs, Some(&clean_cmd), &llvm_build_cmd, &clif_build_cmd);
-
-            spawn_and_wait(bench_compile);
-
-            eprintln!("[BENCH RUN] ebobby/simple-raytracer");
-            fs::copy(
-                target_dir.join("debug").join("main"),
-                RelPath::BUILD.to_path(&runner.dirs).join("raytracer_cg_clif"),
-            )
-            .unwrap();
-
-            let mut bench_run =
-                hyperfine_command(0, run_runs, None, "./raytracer_cg_llvm", "./raytracer_cg_clif");
-            bench_run.current_dir(RelPath::BUILD.to_path(&runner.dirs));
-            spawn_and_wait(bench_run);
-        } else {
-            spawn_and_wait(SIMPLE_RAYTRACER.clean(&runner.target_compiler.cargo, &runner.dirs));
-            eprintln!("[BENCH COMPILE] ebobby/simple-raytracer (skipped)");
-            eprintln!("[COMPILE] ebobby/simple-raytracer");
-            spawn_and_wait(SIMPLE_RAYTRACER.build(&runner.target_compiler, &runner.dirs));
-            eprintln!("[BENCH RUN] ebobby/simple-raytracer (skipped)");
-        }
+    TestCase::custom("test.simple-raytracer", &|runner| {
+        SIMPLE_RAYTRACER.clean(&runner.dirs);
+        spawn_and_wait(SIMPLE_RAYTRACER.build(&runner.target_compiler, &runner.dirs));
     }),
-    TestCase::new("test.libcore", &|runner| {
-        spawn_and_wait(LIBCORE_TESTS.clean(&runner.host_compiler.cargo, &runner.dirs));
+    TestCase::custom("test.libcore", &|runner| {
+        LIBCORE_TESTS.clean(&runner.dirs);
 
         if runner.is_native {
             spawn_and_wait(LIBCORE_TESTS.test(&runner.target_compiler, &runner.dirs));
@@ -344,8 +150,8 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
             spawn_and_wait(build_cmd);
         }
     }),
-    TestCase::new("test.regex-shootout-regex-dna", &|runner| {
-        spawn_and_wait(REGEX.clean(&runner.target_compiler.cargo, &runner.dirs));
+    TestCase::custom("test.regex-shootout-regex-dna", &|runner| {
+        REGEX.clean(&runner.dirs);
 
         // newer aho_corasick versions throw a deprecation warning
         let lint_rust_flags = format!("{} --cap-lints warn", runner.target_compiler.rustflags);
@@ -364,9 +170,10 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
                 REGEX.source_dir(&runner.dirs).join("examples").join("regexdna-input.txt"),
             )
             .unwrap();
-            let expected_path =
-                REGEX.source_dir(&runner.dirs).join("examples").join("regexdna-output.txt");
-            let expected = fs::read_to_string(&expected_path).unwrap();
+            let expected = fs::read_to_string(
+                REGEX.source_dir(&runner.dirs).join("examples").join("regexdna-output.txt"),
+            )
+            .unwrap();
 
             let output = spawn_and_wait_with_input(run_cmd, input);
             // Make sure `[codegen mono items] start` doesn't poison the diff
@@ -379,27 +186,16 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
 
             let output_matches = expected.lines().eq(output.lines());
             if !output_matches {
-                let res_path = REGEX.source_dir(&runner.dirs).join("res.txt");
-                fs::write(&res_path, &output).unwrap();
-
-                if cfg!(windows) {
-                    println!("Output files don't match!");
-                    println!("Expected Output:\n{}", expected);
-                    println!("Actual Output:\n{}", output);
-                } else {
-                    let mut diff = Command::new("diff");
-                    diff.arg("-u");
-                    diff.arg(res_path);
-                    diff.arg(expected_path);
-                    spawn_and_wait(diff);
-                }
+                println!("Output files don't match!");
+                println!("Expected Output:\n{}", expected);
+                println!("Actual Output:\n{}", output);
 
                 std::process::exit(1);
             }
         }
     }),
-    TestCase::new("test.regex", &|runner| {
-        spawn_and_wait(REGEX.clean(&runner.host_compiler.cargo, &runner.dirs));
+    TestCase::custom("test.regex", &|runner| {
+        REGEX.clean(&runner.dirs);
 
         // newer aho_corasick versions throw a deprecation warning
         let lint_rust_flags = format!("{} --cap-lints warn", runner.target_compiler.rustflags);
@@ -425,8 +221,8 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
             spawn_and_wait(build_cmd);
         }
     }),
-    TestCase::new("test.portable-simd", &|runner| {
-        spawn_and_wait(PORTABLE_SIMD.clean(&runner.host_compiler.cargo, &runner.dirs));
+    TestCase::custom("test.portable-simd", &|runner| {
+        PORTABLE_SIMD.clean(&runner.dirs);
 
         let mut build_cmd = PORTABLE_SIMD.build(&runner.target_compiler, &runner.dirs);
         build_cmd.arg("--all-targets");
@@ -445,21 +241,22 @@ pub(crate) fn run_tests(
     channel: &str,
     sysroot_kind: SysrootKind,
     cg_clif_dylib: &Path,
-    host_triple: &str,
-    target_triple: &str,
+    bootstrap_host_compiler: &Compiler,
+    target_triple: String,
 ) {
-    let runner = TestRunner::new(dirs.clone(), host_triple.to_string(), target_triple.to_string());
-
     if config::get_bool("testsuite.no_sysroot") {
-        build_sysroot::build_sysroot(
+        let target_compiler = build_sysroot::build_sysroot(
             dirs,
             channel,
             SysrootKind::None,
             cg_clif_dylib,
-            &host_triple,
-            &target_triple,
+            bootstrap_host_compiler,
+            target_triple.clone(),
         );
 
+        let runner =
+            TestRunner::new(dirs.clone(), target_compiler, get_host_triple() == target_triple);
+
         BUILD_EXAMPLE_OUT_DIR.ensure_fresh(dirs);
         runner.run_testsuite(NO_SYSROOT_SUITE);
     } else {
@@ -470,26 +267,29 @@ pub(crate) fn run_tests(
     let run_extended_sysroot = config::get_bool("testsuite.extended_sysroot");
 
     if run_base_sysroot || run_extended_sysroot {
-        build_sysroot::build_sysroot(
+        let target_compiler = build_sysroot::build_sysroot(
             dirs,
             channel,
             sysroot_kind,
             cg_clif_dylib,
-            &host_triple,
-            &target_triple,
+            bootstrap_host_compiler,
+            target_triple.clone(),
         );
-    }
 
-    if run_base_sysroot {
-        runner.run_testsuite(BASE_SYSROOT_SUITE);
-    } else {
-        eprintln!("[SKIP] base_sysroot tests");
-    }
+        let runner =
+            TestRunner::new(dirs.clone(), target_compiler, get_host_triple() == target_triple);
 
-    if run_extended_sysroot {
-        runner.run_testsuite(EXTENDED_SYSROOT_SUITE);
-    } else {
-        eprintln!("[SKIP] extended_sysroot tests");
+        if run_base_sysroot {
+            runner.run_testsuite(BASE_SYSROOT_SUITE);
+        } else {
+            eprintln!("[SKIP] base_sysroot tests");
+        }
+
+        if run_extended_sysroot {
+            runner.run_testsuite(EXTENDED_SYSROOT_SUITE);
+        } else {
+            eprintln!("[SKIP] extended_sysroot tests");
+        }
     }
 }
 
@@ -497,84 +297,34 @@ struct TestRunner {
     is_native: bool,
     jit_supported: bool,
     dirs: Dirs,
-    host_compiler: Compiler,
     target_compiler: Compiler,
 }
 
 impl TestRunner {
-    pub fn new(dirs: Dirs, host_triple: String, target_triple: String) -> Self {
-        let is_native = host_triple == target_triple;
-        let jit_supported =
-            target_triple.contains("x86_64") && is_native && !host_triple.contains("windows");
-
-        let rustc_clif =
-            RelPath::DIST.to_path(&dirs).join(get_wrapper_file_name("rustc-clif", "bin"));
-        let rustdoc_clif =
-            RelPath::DIST.to_path(&dirs).join(get_wrapper_file_name("rustdoc-clif", "bin"));
-
-        let mut rustflags = env::var("RUSTFLAGS").ok().unwrap_or("".to_string());
-        let mut runner = vec![];
-
-        if !is_native {
-            match target_triple.as_str() {
-                "aarch64-unknown-linux-gnu" => {
-                    // We are cross-compiling for aarch64. Use the correct linker and run tests in qemu.
-                    rustflags = format!("-Clinker=aarch64-linux-gnu-gcc{}", rustflags);
-                    runner = vec![
-                        "qemu-aarch64".to_owned(),
-                        "-L".to_owned(),
-                        "/usr/aarch64-linux-gnu".to_owned(),
-                    ];
-                }
-                "s390x-unknown-linux-gnu" => {
-                    // We are cross-compiling for s390x. Use the correct linker and run tests in qemu.
-                    rustflags = format!("-Clinker=s390x-linux-gnu-gcc{}", rustflags);
-                    runner = vec![
-                        "qemu-s390x".to_owned(),
-                        "-L".to_owned(),
-                        "/usr/s390x-linux-gnu".to_owned(),
-                    ];
-                }
-                "x86_64-pc-windows-gnu" => {
-                    // We are cross-compiling for Windows. Run tests in wine.
-                    runner = vec!["wine".to_owned()];
-                }
-                _ => {
-                    println!("Unknown non-native platform");
-                }
-            }
+    pub fn new(dirs: Dirs, mut target_compiler: Compiler, is_native: bool) -> Self {
+        if let Ok(rustflags) = env::var("RUSTFLAGS") {
+            target_compiler.rustflags.push(' ');
+            target_compiler.rustflags.push_str(&rustflags);
+        }
+        if let Ok(rustdocflags) = env::var("RUSTDOCFLAGS") {
+            target_compiler.rustdocflags.push(' ');
+            target_compiler.rustdocflags.push_str(&rustdocflags);
         }
 
         // FIXME fix `#[linkage = "extern_weak"]` without this
-        if target_triple.contains("darwin") {
-            rustflags = format!("{} -Clink-arg=-undefined -Clink-arg=dynamic_lookup", rustflags);
+        if target_compiler.triple.contains("darwin") {
+            target_compiler.rustflags.push_str(" -Clink-arg=-undefined -Clink-arg=dynamic_lookup");
         }
 
-        let host_compiler = Compiler {
-            cargo: get_cargo_path(),
-            rustc: rustc_clif.clone(),
-            rustdoc: rustdoc_clif.clone(),
-            rustflags: String::new(),
-            rustdocflags: String::new(),
-            triple: host_triple,
-            runner: vec![],
-        };
-
-        let target_compiler = Compiler {
-            cargo: get_cargo_path(),
-            rustc: rustc_clif,
-            rustdoc: rustdoc_clif,
-            rustflags: rustflags.clone(),
-            rustdocflags: rustflags,
-            triple: target_triple,
-            runner,
-        };
-
-        Self { is_native, jit_supported, dirs, host_compiler, target_compiler }
+        let jit_supported = is_native
+            && target_compiler.triple.contains("x86_64")
+            && !target_compiler.triple.contains("windows");
+
+        Self { is_native, jit_supported, dirs, target_compiler }
     }
 
     pub fn run_testsuite(&self, tests: &[TestCase]) {
-        for &TestCase { config, func } in tests {
+        for TestCase { config, cmd } in tests {
             let (tag, testname) = config.split_once('.').unwrap();
             let tag = tag.to_uppercase();
             let is_jit_test = tag == "JIT";
@@ -586,7 +336,47 @@ impl TestRunner {
                 eprintln!("[{tag}] {testname}");
             }
 
-            func(self);
+            match *cmd {
+                TestCaseCmd::Custom { func } => func(self),
+                TestCaseCmd::BuildLib { source, crate_types } => {
+                    self.run_rustc([source, "--crate-type", crate_types]);
+                }
+                TestCaseCmd::BuildBinAndRun { source, args } => {
+                    self.run_rustc([source]);
+                    self.run_out_command(
+                        source.split('/').last().unwrap().split('.').next().unwrap(),
+                        args,
+                    );
+                }
+                TestCaseCmd::JitBin { source, args } => {
+                    let mut jit_cmd = self.rustc_command([
+                        "-Zunstable-options",
+                        "-Cllvm-args=mode=jit",
+                        "-Cprefer-dynamic",
+                        source,
+                        "--cfg",
+                        "jit",
+                    ]);
+                    if !args.is_empty() {
+                        jit_cmd.env("CG_CLIF_JIT_ARGS", args);
+                    }
+                    spawn_and_wait(jit_cmd);
+
+                    eprintln!("[JIT-lazy] {testname}");
+                    let mut jit_cmd = self.rustc_command([
+                        "-Zunstable-options",
+                        "-Cllvm-args=mode=jit-lazy",
+                        "-Cprefer-dynamic",
+                        source,
+                        "--cfg",
+                        "jit",
+                    ]);
+                    if !args.is_empty() {
+                        jit_cmd.env("CG_CLIF_JIT_ARGS", args);
+                    }
+                    spawn_and_wait(jit_cmd);
+                }
+            }
         }
     }
 
@@ -603,6 +393,9 @@ impl TestRunner {
         cmd.arg("--out-dir");
         cmd.arg(format!("{}", BUILD_EXAMPLE_OUT_DIR.to_path(&self.dirs).display()));
         cmd.arg("-Cdebuginfo=2");
+        cmd.arg("--target");
+        cmd.arg(&self.target_compiler.triple);
+        cmd.arg("-Cpanic=abort");
         cmd.args(args);
         cmd
     }
@@ -615,10 +408,7 @@ impl TestRunner {
         spawn_and_wait(self.rustc_command(args));
     }
 
-    fn run_out_command<'a, I>(&self, name: &str, args: I)
-    where
-        I: IntoIterator<Item = &'a str>,
-    {
+    fn run_out_command<'a>(&self, name: &str, args: &[&str]) {
         let mut full_cmd = vec![];
 
         // Prepend the RUN_WRAPPER's
@@ -630,7 +420,7 @@ impl TestRunner {
             BUILD_EXAMPLE_OUT_DIR.to_path(&self.dirs).join(name).to_str().unwrap().to_string(),
         );
 
-        for arg in args.into_iter() {
+        for arg in args {
             full_cmd.push(arg.to_string());
         }
 
diff --git a/compiler/rustc_codegen_cranelift/build_system/usage.txt b/compiler/rustc_codegen_cranelift/build_system/usage.txt
new file mode 100644
index 00000000000..ab98ccc35a5
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/build_system/usage.txt
@@ -0,0 +1,35 @@
+The build system of cg_clif.
+
+USAGE:
+    ./y.rs prepare [--out-dir DIR]
+    ./y.rs build [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
+    ./y.rs test [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
+    ./y.rs abi-cafe [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
+    ./y.rs bench [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--no-unstable-features]
+
+OPTIONS:
+    --debug
+            Build cg_clif and the standard library in debug mode rather than release mode.
+            Warning: An unoptimized cg_clif is very slow.
+
+    --sysroot none|clif|llvm
+            Which sysroot libraries to use:
+            `none` will not include any standard library in the sysroot.
+            `clif` will build the standard library using Cranelift.
+            `llvm` will use the pre-compiled standard library of rustc which is compiled with LLVM.
+
+    --out-dir DIR
+            Specify the directory in which the download, build and dist directories are stored.
+            By default this is the working directory.
+
+    --no-unstable-features
+            Some features are not yet ready for production usage. This option will disable these
+            features. This includes the JIT mode and inline assembly support.
+
+REQUIREMENTS:
+    * Rustup: The build system has a hard coded dependency on rustup to install the right nightly
+      version and make sure it is used where necessary.
+    * Git: `./y.rs prepare` uses git for applying patches and on Windows for downloading test repos.
+    * Curl and tar (non-Windows only): Used by `./y.rs prepare` to download a single commit for
+      repos. Git will be used to clone the whole repo when using Windows.
+    * [Hyperfine](https://github.com/sharkdp/hyperfine/): Used for benchmarking with `./y.rs bench`.
diff --git a/compiler/rustc_codegen_cranelift/build_system/utils.rs b/compiler/rustc_codegen_cranelift/build_system/utils.rs
index 2be70e8e421..da2a94a0a4f 100644
--- a/compiler/rustc_codegen_cranelift/build_system/utils.rs
+++ b/compiler/rustc_codegen_cranelift/build_system/utils.rs
@@ -1,12 +1,13 @@
 use std::env;
 use std::fs;
-use std::io::Write;
+use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 use std::process::{self, Command, Stdio};
 
 use super::path::{Dirs, RelPath};
-use super::rustc_info::{get_cargo_path, get_host_triple, get_rustc_path, get_rustdoc_path};
+use super::rustc_info::{get_cargo_path, get_rustc_path, get_rustdoc_path};
 
+#[derive(Clone, Debug)]
 pub(crate) struct Compiler {
     pub(crate) cargo: PathBuf,
     pub(crate) rustc: PathBuf,
@@ -18,27 +19,47 @@ pub(crate) struct Compiler {
 }
 
 impl Compiler {
-    pub(crate) fn host() -> Compiler {
+    pub(crate) fn bootstrap_with_triple(triple: String) -> Compiler {
         Compiler {
             cargo: get_cargo_path(),
             rustc: get_rustc_path(),
             rustdoc: get_rustdoc_path(),
             rustflags: String::new(),
             rustdocflags: String::new(),
-            triple: get_host_triple(),
+            triple,
             runner: vec![],
         }
     }
 
-    pub(crate) fn with_triple(triple: String) -> Compiler {
-        Compiler {
-            cargo: get_cargo_path(),
-            rustc: get_rustc_path(),
-            rustdoc: get_rustdoc_path(),
-            rustflags: String::new(),
-            rustdocflags: String::new(),
-            triple,
-            runner: vec![],
+    pub(crate) fn set_cross_linker_and_runner(&mut self) {
+        match self.triple.as_str() {
+            "aarch64-unknown-linux-gnu" => {
+                // We are cross-compiling for aarch64. Use the correct linker and run tests in qemu.
+                self.rustflags += " -Clinker=aarch64-linux-gnu-gcc";
+                self.rustdocflags += " -Clinker=aarch64-linux-gnu-gcc";
+                self.runner = vec![
+                    "qemu-aarch64".to_owned(),
+                    "-L".to_owned(),
+                    "/usr/aarch64-linux-gnu".to_owned(),
+                ];
+            }
+            "s390x-unknown-linux-gnu" => {
+                // We are cross-compiling for s390x. Use the correct linker and run tests in qemu.
+                self.rustflags += " -Clinker=s390x-linux-gnu-gcc";
+                self.rustdocflags += " -Clinker=s390x-linux-gnu-gcc";
+                self.runner = vec![
+                    "qemu-s390x".to_owned(),
+                    "-L".to_owned(),
+                    "/usr/s390x-linux-gnu".to_owned(),
+                ];
+            }
+            "x86_64-pc-windows-gnu" => {
+                // We are cross-compiling for Windows. Run tests in wine.
+                self.runner = vec!["wine".to_owned()];
+            }
+            _ => {
+                println!("Unknown non-native platform");
+            }
         }
     }
 }
@@ -65,6 +86,7 @@ impl CargoProject {
         RelPath::BUILD.join(self.target).to_path(dirs)
     }
 
+    #[must_use]
     fn base_cmd(&self, command: &str, cargo: &Path, dirs: &Dirs) -> Command {
         let mut cmd = Command::new(cargo);
 
@@ -72,11 +94,13 @@ impl CargoProject {
             .arg("--manifest-path")
             .arg(self.manifest_path(dirs))
             .arg("--target-dir")
-            .arg(self.target_dir(dirs));
+            .arg(self.target_dir(dirs))
+            .arg("--frozen");
 
         cmd
     }
 
+    #[must_use]
     fn build_cmd(&self, command: &str, compiler: &Compiler, dirs: &Dirs) -> Command {
         let mut cmd = self.base_cmd(command, &compiler.cargo, dirs);
 
@@ -105,9 +129,8 @@ impl CargoProject {
         cmd
     }
 
-    #[must_use]
-    pub(crate) fn clean(&self, cargo: &Path, dirs: &Dirs) -> Command {
-        self.base_cmd("clean", cargo, dirs)
+    pub(crate) fn clean(&self, dirs: &Dirs) {
+        let _ = fs::remove_dir_all(self.target_dir(dirs));
     }
 
     #[must_use]
@@ -153,6 +176,23 @@ pub(crate) fn hyperfine_command(
     bench
 }
 
+#[must_use]
+pub(crate) fn git_command<'a>(repo_dir: impl Into<Option<&'a Path>>, cmd: &str) -> Command {
+    let mut git_cmd = Command::new("git");
+    git_cmd
+        .arg("-c")
+        .arg("user.name=Dummy")
+        .arg("-c")
+        .arg("user.email=dummy@example.com")
+        .arg("-c")
+        .arg("core.autocrlf=false")
+        .arg(cmd);
+    if let Some(repo_dir) = repo_dir.into() {
+        git_cmd.current_dir(repo_dir);
+    }
+    git_cmd
+}
+
 #[track_caller]
 pub(crate) fn try_hard_link(src: impl AsRef<Path>, dst: impl AsRef<Path>) {
     let src = src.as_ref();
@@ -169,6 +209,22 @@ pub(crate) fn spawn_and_wait(mut cmd: Command) {
     }
 }
 
+// Based on the retry function in rust's src/ci/shared.sh
+#[track_caller]
+pub(crate) fn retry_spawn_and_wait(tries: u64, mut cmd: Command) {
+    for i in 1..tries + 1 {
+        if i != 1 {
+            println!("Command failed. Attempt {i}/{tries}:");
+        }
+        if cmd.spawn().unwrap().wait().unwrap().success() {
+            return;
+        }
+        std::thread::sleep(std::time::Duration::from_secs(i * 5));
+    }
+    println!("The command has failed after {tries} attempts.");
+    process::exit(1);
+}
+
 #[track_caller]
 pub(crate) fn spawn_and_wait_with_input(mut cmd: Command, input: String) -> String {
     let mut child = cmd
@@ -190,6 +246,14 @@ pub(crate) fn spawn_and_wait_with_input(mut cmd: Command, input: String) -> Stri
     String::from_utf8(output.stdout).unwrap()
 }
 
+pub(crate) fn remove_dir_if_exists(path: &Path) {
+    match fs::remove_dir_all(&path) {
+        Ok(()) => {}
+        Err(err) if err.kind() == io::ErrorKind::NotFound => {}
+        Err(err) => panic!("Failed to remove {path}: {err}", path = path.display()),
+    }
+}
+
 pub(crate) fn copy_dir_recursively(from: &Path, to: &Path) {
     for entry in fs::read_dir(from).unwrap() {
         let entry = entry.unwrap();
diff --git a/compiler/rustc_codegen_cranelift/clean_all.sh b/compiler/rustc_codegen_cranelift/clean_all.sh
index 1760e5836ec..cdfc2e143e6 100755
--- a/compiler/rustc_codegen_cranelift/clean_all.sh
+++ b/compiler/rustc_codegen_cranelift/clean_all.sh
@@ -1,10 +1,9 @@
 #!/usr/bin/env bash
 set -e
 
-rm -rf build_sysroot/{sysroot_src/,target/,compiler-builtins/,rustc_version}
-rm -rf target/ build/ dist/ perf.data{,.old} y.bin
-rm -rf download/
+rm -rf target/ download/ build/ dist/ y.bin y.bin.dSYM y.exe y.pdb
 
 # Kept for now in case someone updates their checkout of cg_clif before running clean_all.sh
 # FIXME remove at some point in the future
 rm -rf rand/ regex/ simple-raytracer/ portable-simd/ abi-checker/ abi-cafe/
+rm -rf build_sysroot/{sysroot_src/,target/,compiler-builtins/,rustc_version}
diff --git a/compiler/rustc_codegen_cranelift/config.txt b/compiler/rustc_codegen_cranelift/config.txt
index 258b67e9314..d49cc90791a 100644
--- a/compiler/rustc_codegen_cranelift/config.txt
+++ b/compiler/rustc_codegen_cranelift/config.txt
@@ -44,10 +44,8 @@ aot.issue-72793
 
 testsuite.extended_sysroot
 test.rust-random/rand
-bench.simple-raytracer
+test.simple-raytracer
 test.libcore
 test.regex-shootout-regex-dna
 test.regex
 test.portable-simd
-
-testsuite.abi-cafe
diff --git a/compiler/rustc_codegen_cranelift/patches/0001-portable-simd-Disable-unsupported-tests.patch b/compiler/rustc_codegen_cranelift/patches/0001-portable-simd-Disable-unsupported-tests.patch
deleted file mode 100644
index 89e2b61c1fc..00000000000
--- a/compiler/rustc_codegen_cranelift/patches/0001-portable-simd-Disable-unsupported-tests.patch
+++ /dev/null
@@ -1,35 +0,0 @@
-From b742f03694b920cc14400727d54424e8e1b60928 Mon Sep 17 00:00:00 2001
-From: bjorn3 <bjorn3@users.noreply.github.com>
-Date: Thu, 18 Nov 2021 19:28:40 +0100
-Subject: [PATCH] Disable unsupported tests
-
----
- crates/core_simd/src/elements/int.rs     | 8 ++++++++
- crates/core_simd/src/elements/uint.rs    | 4 ++++
- crates/core_simd/src/masks/full_masks.rs | 6 ++++++
- crates/core_simd/src/vector.rs           | 2 ++
- crates/core_simd/tests/masks.rs          | 3 ---
- 5 files changed, 20 insertions(+), 3 deletions(-)
-
-diff --git a/crates/core_simd/src/vector.rs b/crates/core_simd/src/vector.rs
-index e8e8f68..7173c24 100644
---- a/crates/core_simd/src/vector.rs
-+++ b/crates/core_simd/src/vector.rs
-@@ -250,6 +250,7 @@ where
-         unsafe { intrinsics::simd_cast(self) }
-     }
- 
-+    /*
-     /// Reads from potentially discontiguous indices in `slice` to construct a SIMD vector.
-     /// If an index is out-of-bounds, the lane is instead selected from the `or` vector.
-     ///
-@@ -473,6 +474,7 @@ where
-             // Cleared ☢️ *mut T Zone
-         }
-     }
-+    */
- }
- 
- impl<T, const LANES: usize> Copy for Simd<T, LANES>
--- 
-2.25.1
diff --git a/compiler/rustc_codegen_cranelift/patches/0022-sysroot-Disable-not-compiling-tests.patch b/compiler/rustc_codegen_cranelift/patches/0022-sysroot-Disable-not-compiling-tests.patch
index 8d9ee3f25c4..865aa833a5e 100644
--- a/compiler/rustc_codegen_cranelift/patches/0022-sysroot-Disable-not-compiling-tests.patch
+++ b/compiler/rustc_codegen_cranelift/patches/0022-sysroot-Disable-not-compiling-tests.patch
@@ -18,7 +18,7 @@ new file mode 100644
 index 0000000..46fd999
 --- /dev/null
 +++ b/library/core/tests/Cargo.toml
-@@ -0,0 +1,11 @@
+@@ -0,0 +1,12 @@
 +[package]
 +name = "core"
 +version = "0.0.0"
@@ -29,6 +29,7 @@ index 0000000..46fd999
 +path = "lib.rs"
 +
 +[dependencies]
-+rand = "0.7"
++rand = { version = "0.8.5", default-features = false }
++rand_xorshift = { version = "0.3.0", default-features = false }
 --
 2.21.0 (Apple Git-122)
diff --git a/compiler/rustc_codegen_cranelift/rust-toolchain b/compiler/rustc_codegen_cranelift/rust-toolchain
index d8f28dbcc15..77345b9a17c 100644
--- a/compiler/rustc_codegen_cranelift/rust-toolchain
+++ b/compiler/rustc_codegen_cranelift/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2022-12-13"
+channel = "nightly-2023-01-20"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
diff --git a/compiler/rustc_codegen_cranelift/scripts/cargo-clif.rs b/compiler/rustc_codegen_cranelift/scripts/cargo-clif.rs
index 9362b47fa6d..c993430b830 100644
--- a/compiler/rustc_codegen_cranelift/scripts/cargo-clif.rs
+++ b/compiler/rustc_codegen_cranelift/scripts/cargo-clif.rs
@@ -26,7 +26,7 @@ fn main() {
     env::set_var("RUSTDOCFLAGS", env::var("RUSTDOCFLAGS").unwrap_or(String::new()) + &rustflags);
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     let args: Vec<_> = match env::args().nth(1).as_deref() {
         Some("jit") => {
diff --git a/compiler/rustc_codegen_cranelift/scripts/rustc-clif.rs b/compiler/rustc_codegen_cranelift/scripts/rustc-clif.rs
index 3abfcd8ddc8..c187f54a60e 100644
--- a/compiler/rustc_codegen_cranelift/scripts/rustc-clif.rs
+++ b/compiler/rustc_codegen_cranelift/scripts/rustc-clif.rs
@@ -24,7 +24,7 @@ fn main() {
     }
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     #[cfg(unix)]
     Command::new("rustc").args(args).exec();
diff --git a/compiler/rustc_codegen_cranelift/scripts/rustdoc-clif.rs b/compiler/rustc_codegen_cranelift/scripts/rustdoc-clif.rs
index a19d72acfa8..a6528ac41ae 100644
--- a/compiler/rustc_codegen_cranelift/scripts/rustdoc-clif.rs
+++ b/compiler/rustc_codegen_cranelift/scripts/rustdoc-clif.rs
@@ -24,7 +24,7 @@ fn main() {
     }
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     #[cfg(unix)]
     Command::new("rustdoc").args(args).exec();
diff --git a/compiler/rustc_codegen_cranelift/scripts/rustup.sh b/compiler/rustc_codegen_cranelift/scripts/rustup.sh
index bc4c06ed7d2..34e3981b538 100755
--- a/compiler/rustc_codegen_cranelift/scripts/rustup.sh
+++ b/compiler/rustc_codegen_cranelift/scripts/rustup.sh
@@ -17,10 +17,10 @@ case $1 in
         done
 
         ./clean_all.sh
-        ./y.rs prepare
 
-        (cd build_sysroot && cargo update)
+        ./y.rs prepare
 
+        (cd download/sysroot && cargo update && cargo fetch && cp Cargo.lock ../../build_sysroot/)
         ;;
     "commit")
         git add rust-toolchain build_sysroot/Cargo.lock
diff --git a/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh b/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
index 6c64b7de7da..a08e80dd19a 100644
--- a/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
+++ b/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
@@ -10,7 +10,7 @@ git fetch
 git checkout -- .
 git checkout "$(rustc -V | cut -d' ' -f3 | tr -d '(')"
 
-git am ../patches/*-sysroot-*.patch
+git -c user.name=Dummy -c user.email=dummy@example.com am ../patches/*-sysroot-*.patch
 
 git apply - <<EOF
 diff --git a/library/alloc/Cargo.toml b/library/alloc/Cargo.toml
@@ -25,8 +25,8 @@ index d95b5b7f17f..00b6f0e3635 100644
 +compiler_builtins = { version = "0.1.66", features = ['rustc-dep-of-std', 'no-asm'] }
 
  [dev-dependencies]
- rand = "0.7"
- rand_xorshift = "0.2"
+ rand = { version = "0.8.5", default-features = false, features = ["alloc"] }
+ rand_xorshift = "0.3.0"
 EOF
 
 cat > config.toml <<EOF
@@ -51,7 +51,7 @@ popd
 # FIXME remove once inline asm is fully supported
 export RUSTFLAGS="$RUSTFLAGS --cfg=rustix_use_libc"
 
-export CFG_VIRTUAL_RUST_SOURCE_BASE_DIR="$(cd build_sysroot/sysroot_src; pwd)"
+export CFG_VIRTUAL_RUST_SOURCE_BASE_DIR="$(cd download/sysroot/sysroot_src; pwd)"
 
 # Allow the testsuite to use llvm tools
 host_triple=$(rustc -vV | grep host | cut -d: -f2 | tr -d " ")
diff --git a/compiler/rustc_codegen_cranelift/scripts/test_rustc_tests.sh b/compiler/rustc_codegen_cranelift/scripts/test_rustc_tests.sh
index 12ecb8cf4e1..07c9ae6ee9f 100755
--- a/compiler/rustc_codegen_cranelift/scripts/test_rustc_tests.sh
+++ b/compiler/rustc_codegen_cranelift/scripts/test_rustc_tests.sh
@@ -11,7 +11,7 @@ pushd rust
 command -v rg >/dev/null 2>&1 || cargo install ripgrep
 
 rm -r tests/ui/{extern/,unsized-locals/,lto/,linkage*} || true
-for test in $(rg --files-with-matches "lto|// needs-asm-support|// needs-unwind" tests/{ui,incremental}); do
+for test in $(rg --files-with-matches "lto|// needs-asm-support|// needs-unwind" tests/{codegen-units,ui,incremental}); do
   rm $test
 done
 
@@ -32,20 +32,13 @@ rm tests/incremental/issue-80691-bad-eval-cache.rs # -Cpanic=abort causes abort
 # requires compiling with -Cpanic=unwind
 rm -r tests/ui/macros/rfc-2011-nicer-assert-messages/
 rm -r tests/run-make/test-benches
+rm tests/ui/test-attrs/test-type.rs
 
 # vendor intrinsics
 rm tests/ui/sse2.rs # cpuid not supported, so sse2 not detected
 rm tests/ui/intrinsics/const-eval-select-x86_64.rs # requires x86_64 vendor intrinsics
 rm tests/ui/simd/array-type.rs # "Index argument for `simd_insert` is not a constant"
-rm tests/ui/simd/intrinsic/generic-bitmask-pass.rs # simd_bitmask unimplemented
-rm tests/ui/simd/intrinsic/generic-as.rs # simd_as unimplemented
-rm tests/ui/simd/intrinsic/generic-arithmetic-saturating-pass.rs # simd_saturating_add unimplemented
 rm tests/ui/simd/intrinsic/float-math-pass.rs # simd_fcos unimplemented
-rm tests/ui/simd/intrinsic/generic-gather-pass.rs # simd_gather unimplemented
-rm tests/ui/simd/intrinsic/generic-select-pass.rs # simd_select_bitmask unimplemented
-rm tests/ui/simd/issue-85915-simd-ptrs.rs # simd_gather unimplemented
-rm tests/ui/simd/issue-89193.rs # simd_gather unimplemented
-rm tests/ui/simd/simd-bitmask.rs # simd_bitmask unimplemented
 
 # exotic linkages
 rm tests/ui/issues/issue-33992.rs # unsupported linkages
@@ -64,10 +57,7 @@ rm tests/ui/intrinsics/intrinsic-nearby.rs # unimplemented nearbyintf32 and near
 rm tests/ui/target-feature/missing-plusminus.rs # error not implemented
 rm tests/ui/fn/dyn-fn-alignment.rs # wants a 256 byte alignment
 rm -r tests/run-make/emit-named-files # requires full --emit support
-rm tests/ui/abi/stack-probes.rs # stack probes not yet implemented
-rm tests/ui/simd/intrinsic/ptr-cast.rs # simd_expose_addr intrinsic unimplemented
 rm -r tests/run-make/repr128-dwarf # debuginfo test
-rm tests/codegen-units/item-collection/asm-sym.rs # requires support for sym in asm!()
 
 # optimization tests
 # ==================
@@ -88,6 +78,20 @@ rm tests/ui/mir/mir_raw_fat_ptr.rs # same
 rm tests/ui/consts/issue-33537.rs # same
 rm tests/ui/layout/valid_range_oob.rs # different ICE message
 
+rm tests/ui/consts/issue-miri-1910.rs # different error message
+rm tests/ui/consts/offset_ub.rs # same
+rm tests/ui/intrinsics/panic-uninitialized-zeroed.rs # same
+rm tests/ui/lint/lint-const-item-mutation.rs # same
+rm tests/ui/pattern/usefulness/doc-hidden-non-exhaustive.rs # same
+rm tests/ui/suggestions/derive-trait-for-method-call.rs # same
+rm tests/ui/typeck/issue-46112.rs # same
+
+rm tests/ui/proc-macro/crt-static.rs # extra warning about -Cpanic=abort for proc macros
+rm tests/ui/proc-macro/proc-macro-deprecated-attr.rs # same
+rm tests/ui/proc-macro/quote-debug.rs # same
+rm tests/ui/proc-macro/no-missing-docs.rs # same
+rm tests/ui/rust-2018/proc-macro-crate-in-paths.rs # same
+
 # doesn't work due to the way the rustc test suite is invoked.
 # should work when using ./x.py test the way it is intended
 # ============================================================
@@ -102,23 +106,20 @@ rm -r tests/ui/consts/missing_span_in_backtrace.rs # expects sysroot source to b
 # ============
 rm tests/incremental/spike-neg1.rs # errors out for some reason
 rm tests/incremental/spike-neg2.rs # same
-rm tests/ui/issues/issue-74564-if-expr-stack-overflow.rs # gives a stackoverflow before the backend runs
-rm tests/ui/mir/ssa-analysis-regression-50041.rs # produces ICE
-rm tests/ui/type-alias-impl-trait/assoc-projection-ice.rs # produces ICE
 
 rm tests/ui/simd/intrinsic/generic-reduction-pass.rs # simd_reduce_add_unordered doesn't accept an accumulator for integer vectors
 
-rm tests/ui/runtime/out-of-stack.rs # SIGSEGV instead of SIGABRT for some reason (#1301)
+rm tests/ui/simd/intrinsic/generic-as.rs # crash when accessing vector type filed (#1318)
+rm tests/ui/simd/simd-bitmask.rs # crash
+
+rm tests/ui/dyn-star/dyn-star-to-dyn.rs
+rm tests/ui/dyn-star/dispatch-on-pin-mut.rs
 
 # bugs in the test suite
 # ======================
 rm tests/ui/backtrace.rs # TODO warning
 rm tests/ui/simple_global_asm.rs # TODO add needs-asm-support
-rm tests/ui/test-attrs/test-type.rs # TODO panic message on stderr. correct stdout
-# not sure if this is actually a bug in the test suite, but the symbol list shows the function without leading _ for some reason
-rm -r tests/run-make/native-link-modifier-bundle
 rm tests/ui/process/nofile-limit.rs # TODO some AArch64 linking issue
-rm tests/ui/dyn-star/dispatch-on-pin-mut.rs # TODO failed assertion in vtable::get_ptr_and_method_ref
 
 rm tests/ui/stdio-is-blocking.rs # really slow with unoptimized libstd
 
diff --git a/compiler/rustc_codegen_cranelift/src/abi/mod.rs b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
index 65cc6b43767..3c34585d419 100644
--- a/compiler/rustc_codegen_cranelift/src/abi/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
@@ -7,6 +7,7 @@ mod returning;
 use cranelift_module::ModuleError;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::ty::layout::FnAbiOf;
+use rustc_session::Session;
 use rustc_target::abi::call::{Conv, FnAbi};
 use rustc_target::spec::abi::Abi;
 
@@ -22,7 +23,7 @@ fn clif_sig_from_fn_abi<'tcx>(
     default_call_conv: CallConv,
     fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
 ) -> Signature {
-    let call_conv = conv_to_call_conv(fn_abi.conv, default_call_conv);
+    let call_conv = conv_to_call_conv(tcx.sess, fn_abi.conv, default_call_conv);
 
     let inputs = fn_abi.args.iter().map(|arg_abi| arg_abi.get_abi_param(tcx).into_iter()).flatten();
 
@@ -33,24 +34,32 @@ fn clif_sig_from_fn_abi<'tcx>(
     Signature { params, returns, call_conv }
 }
 
-pub(crate) fn conv_to_call_conv(c: Conv, default_call_conv: CallConv) -> CallConv {
+pub(crate) fn conv_to_call_conv(sess: &Session, c: Conv, default_call_conv: CallConv) -> CallConv {
     match c {
         Conv::Rust | Conv::C => default_call_conv,
         Conv::RustCold => CallConv::Cold,
         Conv::X86_64SysV => CallConv::SystemV,
         Conv::X86_64Win64 => CallConv::WindowsFastcall,
-        Conv::ArmAapcs
-        | Conv::CCmseNonSecureCall
-        | Conv::Msp430Intr
+
+        // Should already get a back compat warning
+        Conv::X86Fastcall | Conv::X86Stdcall | Conv::X86ThisCall | Conv::X86VectorCall => {
+            default_call_conv
+        }
+
+        Conv::X86Intr => sess.fatal("x86-interrupt call conv not yet implemented"),
+
+        Conv::ArmAapcs => sess.fatal("aapcs call conv not yet implemented"),
+        Conv::CCmseNonSecureCall => {
+            sess.fatal("C-cmse-nonsecure-call call conv is not yet implemented");
+        }
+
+        Conv::Msp430Intr
         | Conv::PtxKernel
-        | Conv::X86Fastcall
-        | Conv::X86Intr
-        | Conv::X86Stdcall
-        | Conv::X86ThisCall
-        | Conv::X86VectorCall
         | Conv::AmdGpuKernel
         | Conv::AvrInterrupt
-        | Conv::AvrNonBlockingInterrupt => todo!("{:?}", c),
+        | Conv::AvrNonBlockingInterrupt => {
+            unreachable!("tried to use {c:?} call conv which only exists on an unsupported target");
+        }
     }
 }
 
@@ -161,6 +170,12 @@ fn make_local_place<'tcx>(
     layout: TyAndLayout<'tcx>,
     is_ssa: bool,
 ) -> CPlace<'tcx> {
+    if layout.is_unsized() {
+        fx.tcx.sess.span_fatal(
+            fx.mir.local_decls[local].source_info.span,
+            "unsized locals are not yet supported",
+        );
+    }
     let place = if is_ssa {
         if let rustc_target::abi::Abi::ScalarPair(_, _) = layout.abi {
             CPlace::new_var_pair(fx, local, layout)
diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
index 89d955e8bf2..dffb2ed8f4f 100644
--- a/compiler/rustc_codegen_cranelift/src/base.rs
+++ b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -113,6 +113,8 @@ pub(crate) fn codegen_fn<'tcx>(
     };
 
     tcx.sess.time("codegen clif ir", || codegen_fn_body(&mut fx, start_block));
+    fx.bcx.seal_all_blocks();
+    fx.bcx.finalize();
 
     // Recover all necessary data from fx, before accessing func will prevent future access to it.
     let symbol_name = fx.symbol_name;
@@ -303,6 +305,9 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
         let source_info = bb_data.terminator().source_info;
         fx.set_debug_loc(source_info);
 
+        let _print_guard =
+            crate::PrintOnPanic(|| format!("terminator {:?}", bb_data.terminator().kind));
+
         match &bb_data.terminator().kind {
             TerminatorKind::Goto { target } => {
                 if let TerminatorKind::Return = fx.mir[*target].terminator().kind {
@@ -464,7 +469,10 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
                     *destination,
                 );
             }
-            TerminatorKind::Resume | TerminatorKind::Abort => {
+            TerminatorKind::Abort => {
+                codegen_panic_cannot_unwind(fx, source_info);
+            }
+            TerminatorKind::Resume => {
                 // FIXME implement unwinding
                 fx.bcx.ins().trap(TrapCode::UnreachableCodeReached);
             }
@@ -487,9 +495,6 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
             }
         };
     }
-
-    fx.bcx.seal_all_blocks();
-    fx.bcx.finalize();
 }
 
 fn codegen_stmt<'tcx>(
@@ -789,6 +794,7 @@ fn codegen_stmt<'tcx>(
         StatementKind::StorageLive(_)
         | StatementKind::StorageDead(_)
         | StatementKind::Deinit(_)
+        | StatementKind::ConstEvalCounter
         | StatementKind::Nop
         | StatementKind::FakeRead(..)
         | StatementKind::Retag { .. }
@@ -932,7 +938,28 @@ pub(crate) fn codegen_panic<'tcx>(
     codegen_panic_inner(fx, rustc_hir::LangItem::Panic, &args, source_info.span);
 }
 
-pub(crate) fn codegen_panic_inner<'tcx>(
+pub(crate) fn codegen_panic_nounwind<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    msg_str: &str,
+    source_info: mir::SourceInfo,
+) {
+    let msg_ptr = fx.anonymous_str(msg_str);
+    let msg_len = fx.bcx.ins().iconst(fx.pointer_type, i64::try_from(msg_str.len()).unwrap());
+    let args = [msg_ptr, msg_len];
+
+    codegen_panic_inner(fx, rustc_hir::LangItem::PanicNounwind, &args, source_info.span);
+}
+
+pub(crate) fn codegen_panic_cannot_unwind<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    source_info: mir::SourceInfo,
+) {
+    let args = [];
+
+    codegen_panic_inner(fx, rustc_hir::LangItem::PanicCannotUnwind, &args, source_info.span);
+}
+
+fn codegen_panic_inner<'tcx>(
     fx: &mut FunctionCx<'_, '_, 'tcx>,
     lang_item: rustc_hir::LangItem,
     args: &[Value],
@@ -949,11 +976,7 @@ pub(crate) fn codegen_panic_inner<'tcx>(
 
     fx.lib_call(
         &*symbol_name,
-        vec![
-            AbiParam::new(fx.pointer_type),
-            AbiParam::new(fx.pointer_type),
-            AbiParam::new(fx.pointer_type),
-        ],
+        args.iter().map(|&arg| AbiParam::new(fx.bcx.func.dfg.value_type(arg))).collect(),
         vec![],
         args,
     );
diff --git a/compiler/rustc_codegen_cranelift/src/common.rs b/compiler/rustc_codegen_cranelift/src/common.rs
index 2dcd42fbd8f..f41af3a9e63 100644
--- a/compiler/rustc_codegen_cranelift/src/common.rs
+++ b/compiler/rustc_codegen_cranelift/src/common.rs
@@ -35,7 +35,8 @@ pub(crate) fn scalar_to_clif_type(tcx: TyCtxt<'_>, scalar: Scalar) -> Type {
         },
         Primitive::F32 => types::F32,
         Primitive::F64 => types::F64,
-        Primitive::Pointer => pointer_ty(tcx),
+        // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+        Primitive::Pointer(_) => pointer_ty(tcx),
     }
 }
 
@@ -167,6 +168,15 @@ pub(crate) fn codegen_icmp_imm(
     }
 }
 
+pub(crate) fn codegen_bitcast(fx: &mut FunctionCx<'_, '_, '_>, dst_ty: Type, val: Value) -> Value {
+    let mut flags = MemFlags::new();
+    flags.set_endianness(match fx.tcx.data_layout.endian {
+        rustc_target::abi::Endian::Big => cranelift_codegen::ir::Endianness::Big,
+        rustc_target::abi::Endian::Little => cranelift_codegen::ir::Endianness::Little,
+    });
+    fx.bcx.ins().bitcast(dst_ty, flags, val)
+}
+
 pub(crate) fn type_zero_value(bcx: &mut FunctionBuilder<'_>, ty: Type) -> Value {
     if ty == types::I128 {
         let zero = bcx.ins().iconst(types::I64, 0);
diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs
index 51450897bfc..49c4f1aaaef 100644
--- a/compiler/rustc_codegen_cranelift/src/constant.rs
+++ b/compiler/rustc_codegen_cranelift/src/constant.rs
@@ -530,6 +530,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
                         | StatementKind::Retag(_, _)
                         | StatementKind::AscribeUserType(_, _)
                         | StatementKind::Coverage(_)
+                        | StatementKind::ConstEvalCounter
                         | StatementKind::Nop => {}
                     }
                 }
diff --git a/compiler/rustc_codegen_cranelift/src/cranelift_native.rs b/compiler/rustc_codegen_cranelift/src/cranelift_native.rs
new file mode 100644
index 00000000000..6c4efca4424
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/src/cranelift_native.rs
@@ -0,0 +1,248 @@
+// Vendored from https://github.com/bytecodealliance/wasmtime/blob/b58a197d33f044193c3d608010f5e6ec394ac07e/cranelift/native/src/lib.rs
+// which is licensed as
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+// unlike rustc_codegen_cranelift itself. Also applies a small change to remove #![cfg_attr] that
+// rust's CI complains about and to fix formatting to match rustc.
+// FIXME revert back to the external crate with Cranelift 0.93
+#![allow(warnings)]
+
+//! Performs autodetection of the host for the purposes of running
+//! Cranelift to generate code to run on the same machine.
+
+#![deny(missing_docs, trivial_numeric_casts, unused_extern_crates, unstable_features)]
+#![warn(unused_import_braces)]
+
+use cranelift_codegen::isa;
+use target_lexicon::Triple;
+
+/// Return an `isa` builder configured for the current host
+/// machine, or `Err(())` if the host machine is not supported
+/// in the current configuration.
+pub fn builder() -> Result<isa::Builder, &'static str> {
+    builder_with_options(true)
+}
+
+/// Return an `isa` builder configured for the current host
+/// machine, or `Err(())` if the host machine is not supported
+/// in the current configuration.
+///
+/// Selects the given backend variant specifically; this is
+/// useful when more than oen backend exists for a given target
+/// (e.g., on x86-64).
+pub fn builder_with_options(infer_native_flags: bool) -> Result<isa::Builder, &'static str> {
+    let mut isa_builder = isa::lookup(Triple::host()).map_err(|err| match err {
+        isa::LookupError::SupportDisabled => "support for architecture disabled at compile time",
+        isa::LookupError::Unsupported => "unsupported architecture",
+    })?;
+
+    #[cfg(target_arch = "x86_64")]
+    {
+        use cranelift_codegen::settings::Configurable;
+
+        if !std::is_x86_feature_detected!("sse2") {
+            return Err("x86 support requires SSE2");
+        }
+
+        if !infer_native_flags {
+            return Ok(isa_builder);
+        }
+
+        // These are temporarily enabled by default (see #3810 for
+        // more) so that a default-constructed `Flags` can work with
+        // default Wasmtime features. Otherwise, the user must
+        // explicitly use native flags or turn these on when on x86-64
+        // platforms to avoid a configuration panic. In order for the
+        // "enable if detected" logic below to work, we must turn them
+        // *off* (differing from the default) and then re-enable below
+        // if present.
+        isa_builder.set("has_sse3", "false").unwrap();
+        isa_builder.set("has_ssse3", "false").unwrap();
+        isa_builder.set("has_sse41", "false").unwrap();
+        isa_builder.set("has_sse42", "false").unwrap();
+
+        if std::is_x86_feature_detected!("sse3") {
+            isa_builder.enable("has_sse3").unwrap();
+        }
+        if std::is_x86_feature_detected!("ssse3") {
+            isa_builder.enable("has_ssse3").unwrap();
+        }
+        if std::is_x86_feature_detected!("sse4.1") {
+            isa_builder.enable("has_sse41").unwrap();
+        }
+        if std::is_x86_feature_detected!("sse4.2") {
+            isa_builder.enable("has_sse42").unwrap();
+        }
+        if std::is_x86_feature_detected!("popcnt") {
+            isa_builder.enable("has_popcnt").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx") {
+            isa_builder.enable("has_avx").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx2") {
+            isa_builder.enable("has_avx2").unwrap();
+        }
+        if std::is_x86_feature_detected!("fma") {
+            isa_builder.enable("has_fma").unwrap();
+        }
+        if std::is_x86_feature_detected!("bmi1") {
+            isa_builder.enable("has_bmi1").unwrap();
+        }
+        if std::is_x86_feature_detected!("bmi2") {
+            isa_builder.enable("has_bmi2").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx512bitalg") {
+            isa_builder.enable("has_avx512bitalg").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx512dq") {
+            isa_builder.enable("has_avx512dq").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx512f") {
+            isa_builder.enable("has_avx512f").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx512vl") {
+            isa_builder.enable("has_avx512vl").unwrap();
+        }
+        if std::is_x86_feature_detected!("avx512vbmi") {
+            isa_builder.enable("has_avx512vbmi").unwrap();
+        }
+        if std::is_x86_feature_detected!("lzcnt") {
+            isa_builder.enable("has_lzcnt").unwrap();
+        }
+    }
+
+    #[cfg(target_arch = "aarch64")]
+    {
+        use cranelift_codegen::settings::Configurable;
+
+        if !infer_native_flags {
+            return Ok(isa_builder);
+        }
+
+        if std::arch::is_aarch64_feature_detected!("lse") {
+            isa_builder.enable("has_lse").unwrap();
+        }
+
+        if std::arch::is_aarch64_feature_detected!("paca") {
+            isa_builder.enable("has_pauth").unwrap();
+        }
+
+        if cfg!(target_os = "macos") {
+            // Pointer authentication is always available on Apple Silicon.
+            isa_builder.enable("sign_return_address").unwrap();
+            // macOS enforces the use of the B key for return addresses.
+            isa_builder.enable("sign_return_address_with_bkey").unwrap();
+        }
+    }
+
+    // There is no is_s390x_feature_detected macro yet, so for now
+    // we use getauxval from the libc crate directly.
+    #[cfg(all(target_arch = "s390x", target_os = "linux"))]
+    {
+        use cranelift_codegen::settings::Configurable;
+
+        if !infer_native_flags {
+            return Ok(isa_builder);
+        }
+
+        let v = unsafe { libc::getauxval(libc::AT_HWCAP) };
+        const HWCAP_S390X_VXRS_EXT2: libc::c_ulong = 32768;
+        if (v & HWCAP_S390X_VXRS_EXT2) != 0 {
+            isa_builder.enable("has_vxrs_ext2").unwrap();
+            // There is no separate HWCAP bit for mie2, so assume
+            // that any machine with vxrs_ext2 also has mie2.
+            isa_builder.enable("has_mie2").unwrap();
+        }
+    }
+
+    // `is_riscv_feature_detected` is nightly only for now, use
+    // getauxval from the libc crate directly as a temporary measure.
+    #[cfg(all(target_arch = "riscv64", target_os = "linux"))]
+    {
+        use cranelift_codegen::settings::Configurable;
+
+        if !infer_native_flags {
+            return Ok(isa_builder);
+        }
+
+        let v = unsafe { libc::getauxval(libc::AT_HWCAP) };
+
+        const HWCAP_RISCV_EXT_A: libc::c_ulong = 1 << (b'a' - b'a');
+        const HWCAP_RISCV_EXT_C: libc::c_ulong = 1 << (b'c' - b'a');
+        const HWCAP_RISCV_EXT_D: libc::c_ulong = 1 << (b'd' - b'a');
+        const HWCAP_RISCV_EXT_F: libc::c_ulong = 1 << (b'f' - b'a');
+        const HWCAP_RISCV_EXT_M: libc::c_ulong = 1 << (b'm' - b'a');
+        const HWCAP_RISCV_EXT_V: libc::c_ulong = 1 << (b'v' - b'a');
+
+        if (v & HWCAP_RISCV_EXT_A) != 0 {
+            isa_builder.enable("has_a").unwrap();
+        }
+
+        if (v & HWCAP_RISCV_EXT_C) != 0 {
+            isa_builder.enable("has_c").unwrap();
+        }
+
+        if (v & HWCAP_RISCV_EXT_D) != 0 {
+            isa_builder.enable("has_d").unwrap();
+        }
+
+        if (v & HWCAP_RISCV_EXT_F) != 0 {
+            isa_builder.enable("has_f").unwrap();
+
+            // TODO: There doesn't seem to be a bit associated with this extension
+            // rust enables it with the `f` extension:
+            // https://github.com/rust-lang/stdarch/blob/790411f93c4b5eada3c23abb4c9a063fb0b24d99/crates/std_detect/src/detect/os/linux/riscv.rs#L43
+            isa_builder.enable("has_zicsr").unwrap();
+        }
+
+        if (v & HWCAP_RISCV_EXT_M) != 0 {
+            isa_builder.enable("has_m").unwrap();
+        }
+
+        if (v & HWCAP_RISCV_EXT_V) != 0 {
+            isa_builder.enable("has_v").unwrap();
+        }
+
+        // TODO: ZiFencei does not have a bit associated with it
+        // TODO: Zbkb does not have a bit associated with it
+    }
+
+    // squelch warnings about unused mut/variables on some platforms.
+    drop(&mut isa_builder);
+    drop(infer_native_flags);
+
+    Ok(isa_builder)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::builder;
+    use cranelift_codegen::isa::CallConv;
+    use cranelift_codegen::settings;
+
+    #[test]
+    fn test() {
+        if let Ok(isa_builder) = builder() {
+            let flag_builder = settings::builder();
+            let isa = isa_builder.finish(settings::Flags::new(flag_builder)).unwrap();
+
+            if cfg!(all(target_os = "macos", target_arch = "aarch64")) {
+                assert_eq!(isa.default_call_conv(), CallConv::AppleAarch64);
+            } else if cfg!(any(unix, target_os = "nebulet")) {
+                assert_eq!(isa.default_call_conv(), CallConv::SystemV);
+            } else if cfg!(windows) {
+                assert_eq!(isa.default_call_conv(), CallConv::WindowsFastcall);
+            }
+
+            if cfg!(target_pointer_width = "64") {
+                assert_eq!(isa.pointer_bits(), 64);
+            } else if cfg!(target_pointer_width = "32") {
+                assert_eq!(isa.pointer_bits(), 32);
+            } else if cfg!(target_pointer_width = "16") {
+                assert_eq!(isa.pointer_bits(), 16);
+            }
+        }
+    }
+}
+
+/// Version number of this crate.
+pub const VERSION: &str = env!("CARGO_PKG_VERSION");
diff --git a/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs b/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs
index 28fbcb15b2b..3a7421d8b30 100644
--- a/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs
@@ -20,6 +20,14 @@ use indexmap::IndexSet;
 pub(crate) use emit::{DebugReloc, DebugRelocName};
 pub(crate) use unwind::UnwindContext;
 
+pub(crate) fn producer() -> String {
+    format!(
+        "cg_clif (rustc {}, cranelift {})",
+        rustc_interface::util::rustc_version_str().unwrap_or("unknown version"),
+        cranelift_codegen::VERSION,
+    )
+}
+
 pub(crate) struct DebugContext {
     endian: RunTimeEndian,
 
@@ -57,11 +65,7 @@ impl DebugContext {
 
         let mut dwarf = DwarfUnit::new(encoding);
 
-        let producer = format!(
-            "cg_clif (rustc {}, cranelift {})",
-            rustc_interface::util::rustc_version_str().unwrap_or("unknown version"),
-            cranelift_codegen::VERSION,
-        );
+        let producer = producer();
         let comp_dir = tcx
             .sess
             .opts
diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
index f873561c171..d4494a9e45d 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/aot.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
@@ -108,6 +108,8 @@ impl OngoingCodegen {
 
         self.concurrency_limiter.finished();
 
+        sess.abort_if_errors();
+
         (
             CodegenResults {
                 modules,
@@ -169,10 +171,22 @@ fn emit_cgu(
 fn emit_module(
     output_filenames: &OutputFilenames,
     prof: &SelfProfilerRef,
-    object: cranelift_object::object::write::Object<'_>,
+    mut object: cranelift_object::object::write::Object<'_>,
     kind: ModuleKind,
     name: String,
 ) -> Result<CompiledModule, String> {
+    if object.format() == cranelift_object::object::BinaryFormat::Elf {
+        let comment_section = object.add_section(
+            Vec::new(),
+            b".comment".to_vec(),
+            cranelift_object::object::SectionKind::OtherString,
+        );
+        let mut producer = vec![0];
+        producer.extend(crate::debuginfo::producer().as_bytes());
+        producer.push(0);
+        object.set_section_data(comment_section, producer, 1);
+    }
+
     let tmp_file = output_filenames.temp_path(OutputType::Object, Some(&name));
     let mut file = match File::create(&tmp_file) {
         Ok(file) => file,
@@ -399,8 +413,6 @@ pub(crate) fn run_aot(
             .collect::<Vec<_>>()
     });
 
-    tcx.sess.abort_if_errors();
-
     let mut allocator_module = make_module(tcx.sess, &backend_config, "allocator_shim".to_string());
     let mut allocator_unwind_context = UnwindContext::new(allocator_module.isa(), true);
     let created_alloc_shim =
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/llvm_x86.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/llvm_x86.rs
index 7bc161fbe55..d2ae6978ca2 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/llvm_x86.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/llvm_x86.rs
@@ -33,8 +33,8 @@ pub(crate) fn codegen_x86_llvm_intrinsic_call<'tcx>(
 
                 // cast float to int
                 let a_lane = match lane_ty {
-                    types::F32 => fx.bcx.ins().bitcast(types::I32, a_lane),
-                    types::F64 => fx.bcx.ins().bitcast(types::I64, a_lane),
+                    types::F32 => codegen_bitcast(fx, types::I32, a_lane),
+                    types::F64 => codegen_bitcast(fx, types::I64, a_lane),
                     _ => a_lane,
                 };
 
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
index e4ac89a7bec..d561cf139b6 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
@@ -21,6 +21,7 @@ mod simd;
 pub(crate) use cpuid::codegen_cpuid_call;
 pub(crate) use llvm::codegen_llvm_intrinsic_call;
 
+use rustc_middle::ty::layout::HasParamEnv;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_span::symbol::{kw, sym, Symbol};
@@ -200,7 +201,7 @@ fn bool_to_zero_or_max_uint<'tcx>(
     let mut res = fx.bcx.ins().bmask(int_ty, val);
 
     if ty.is_float() {
-        res = fx.bcx.ins().bitcast(ty, res);
+        res = codegen_bitcast(fx, ty, res);
     }
 
     res
@@ -240,10 +241,9 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
             substs,
             args,
             destination,
+            target,
             source_info.span,
         );
-        let ret_block = fx.get_block(target);
-        fx.bcx.ins().jump(ret_block, &[]);
     } else if codegen_float_intrinsic_call(fx, intrinsic, args, destination) {
         let ret_block = fx.get_block(target);
         fx.bcx.ins().jump(ret_block, &[]);
@@ -650,7 +650,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
             let layout = fx.layout_of(substs.type_at(0));
             if layout.abi.is_uninhabited() {
                 with_no_trimmed_paths!({
-                    crate::base::codegen_panic(
+                    crate::base::codegen_panic_nounwind(
                         fx,
                         &format!("attempted to instantiate uninhabited type `{}`", layout.ty),
                         source_info,
@@ -659,9 +659,11 @@ fn codegen_regular_intrinsic_call<'tcx>(
                 return;
             }
 
-            if intrinsic == sym::assert_zero_valid && !fx.tcx.permits_zero_init(layout) {
+            if intrinsic == sym::assert_zero_valid
+                && !fx.tcx.permits_zero_init(fx.param_env().and(layout))
+            {
                 with_no_trimmed_paths!({
-                    crate::base::codegen_panic(
+                    crate::base::codegen_panic_nounwind(
                         fx,
                         &format!(
                             "attempted to zero-initialize type `{}`, which is invalid",
@@ -674,10 +676,10 @@ fn codegen_regular_intrinsic_call<'tcx>(
             }
 
             if intrinsic == sym::assert_mem_uninitialized_valid
-                && !fx.tcx.permits_uninit_init(layout)
+                && !fx.tcx.permits_uninit_init(fx.param_env().and(layout))
             {
                 with_no_trimmed_paths!({
-                    crate::base::codegen_panic(
+                    crate::base::codegen_panic_nounwind(
                         fx,
                         &format!(
                             "attempted to leave type `{}` uninitialized, which is invalid",
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs
index 14f5e918739..b33eb29754a 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs
@@ -24,6 +24,7 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
     _substs: SubstsRef<'tcx>,
     args: &[mir::Operand<'tcx>],
     ret: CPlace<'tcx>,
+    target: BasicBlock,
     span: Span,
 ) {
     match intrinsic {
@@ -277,16 +278,15 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
             } else {
                 fx.tcx.sess.span_warn(span, "Index argument for `simd_extract` is not a constant");
                 let trap_block = fx.bcx.create_block();
-                let dummy_block = fx.bcx.create_block();
                 let true_ = fx.bcx.ins().iconst(types::I8, 1);
                 fx.bcx.ins().brnz(true_, trap_block, &[]);
-                fx.bcx.ins().jump(dummy_block, &[]);
+                let ret_block = fx.get_block(target);
+                fx.bcx.ins().jump(ret_block, &[]);
                 fx.bcx.switch_to_block(trap_block);
                 crate::trap::trap_unimplemented(
                     fx,
                     "Index argument for `simd_extract` is not a constant",
                 );
-                fx.bcx.switch_to_block(dummy_block);
                 return;
             };
 
@@ -770,11 +770,119 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
             });
         }
 
-        // simd_arith_offset
-        // simd_scatter
-        // simd_gather
+        sym::simd_expose_addr | sym::simd_from_exposed_addr | sym::simd_cast_ptr => {
+            intrinsic_args!(fx, args => (arg); intrinsic);
+            ret.write_cvalue_transmute(fx, arg);
+        }
+
+        sym::simd_arith_offset => {
+            intrinsic_args!(fx, args => (ptr, offset); intrinsic);
+
+            let (lane_count, ptr_lane_ty) = ptr.layout().ty.simd_size_and_type(fx.tcx);
+            let pointee_ty = ptr_lane_ty.builtin_deref(true).unwrap().ty;
+            let pointee_size = fx.layout_of(pointee_ty).size.bytes();
+            let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
+            let ret_lane_layout = fx.layout_of(ret_lane_ty);
+            assert_eq!(lane_count, ret_lane_count);
+
+            for lane_idx in 0..lane_count {
+                let ptr_lane = ptr.value_lane(fx, lane_idx).load_scalar(fx);
+                let offset_lane = offset.value_lane(fx, lane_idx).load_scalar(fx);
+
+                let ptr_diff = if pointee_size != 1 {
+                    fx.bcx.ins().imul_imm(offset_lane, pointee_size as i64)
+                } else {
+                    offset_lane
+                };
+                let res_lane = fx.bcx.ins().iadd(ptr_lane, ptr_diff);
+                let res_lane = CValue::by_val(res_lane, ret_lane_layout);
+
+                ret.place_lane(fx, lane_idx).write_cvalue(fx, res_lane);
+            }
+        }
+
+        sym::simd_gather => {
+            intrinsic_args!(fx, args => (val, ptr, mask); intrinsic);
+
+            let (val_lane_count, val_lane_ty) = val.layout().ty.simd_size_and_type(fx.tcx);
+            let (ptr_lane_count, _ptr_lane_ty) = ptr.layout().ty.simd_size_and_type(fx.tcx);
+            let (mask_lane_count, _mask_lane_ty) = mask.layout().ty.simd_size_and_type(fx.tcx);
+            let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
+            assert_eq!(val_lane_count, ptr_lane_count);
+            assert_eq!(val_lane_count, mask_lane_count);
+            assert_eq!(val_lane_count, ret_lane_count);
+
+            let lane_clif_ty = fx.clif_type(val_lane_ty).unwrap();
+            let ret_lane_layout = fx.layout_of(ret_lane_ty);
+
+            for lane_idx in 0..ptr_lane_count {
+                let val_lane = val.value_lane(fx, lane_idx).load_scalar(fx);
+                let ptr_lane = ptr.value_lane(fx, lane_idx).load_scalar(fx);
+                let mask_lane = mask.value_lane(fx, lane_idx).load_scalar(fx);
+
+                let if_enabled = fx.bcx.create_block();
+                let if_disabled = fx.bcx.create_block();
+                let next = fx.bcx.create_block();
+                let res_lane = fx.bcx.append_block_param(next, lane_clif_ty);
+
+                fx.bcx.ins().brnz(mask_lane, if_enabled, &[]);
+                fx.bcx.ins().jump(if_disabled, &[]);
+                fx.bcx.seal_block(if_enabled);
+                fx.bcx.seal_block(if_disabled);
+
+                fx.bcx.switch_to_block(if_enabled);
+                let res = fx.bcx.ins().load(lane_clif_ty, MemFlags::trusted(), ptr_lane, 0);
+                fx.bcx.ins().jump(next, &[res]);
+
+                fx.bcx.switch_to_block(if_disabled);
+                fx.bcx.ins().jump(next, &[val_lane]);
+
+                fx.bcx.seal_block(next);
+                fx.bcx.switch_to_block(next);
+
+                fx.bcx.ins().nop();
+
+                ret.place_lane(fx, lane_idx)
+                    .write_cvalue(fx, CValue::by_val(res_lane, ret_lane_layout));
+            }
+        }
+
+        sym::simd_scatter => {
+            intrinsic_args!(fx, args => (val, ptr, mask); intrinsic);
+
+            let (val_lane_count, _val_lane_ty) = val.layout().ty.simd_size_and_type(fx.tcx);
+            let (ptr_lane_count, _ptr_lane_ty) = ptr.layout().ty.simd_size_and_type(fx.tcx);
+            let (mask_lane_count, _mask_lane_ty) = mask.layout().ty.simd_size_and_type(fx.tcx);
+            assert_eq!(val_lane_count, ptr_lane_count);
+            assert_eq!(val_lane_count, mask_lane_count);
+
+            for lane_idx in 0..ptr_lane_count {
+                let val_lane = val.value_lane(fx, lane_idx).load_scalar(fx);
+                let ptr_lane = ptr.value_lane(fx, lane_idx).load_scalar(fx);
+                let mask_lane = mask.value_lane(fx, lane_idx).load_scalar(fx);
+
+                let if_enabled = fx.bcx.create_block();
+                let next = fx.bcx.create_block();
+
+                fx.bcx.ins().brnz(mask_lane, if_enabled, &[]);
+                fx.bcx.ins().jump(next, &[]);
+                fx.bcx.seal_block(if_enabled);
+
+                fx.bcx.switch_to_block(if_enabled);
+                fx.bcx.ins().store(MemFlags::trusted(), val_lane, ptr_lane, 0);
+                fx.bcx.ins().jump(next, &[]);
+
+                fx.bcx.seal_block(next);
+                fx.bcx.switch_to_block(next);
+            }
+        }
+
         _ => {
-            fx.tcx.sess.span_fatal(span, &format!("Unknown SIMD intrinsic {}", intrinsic));
+            fx.tcx.sess.span_err(span, &format!("Unknown SIMD intrinsic {}", intrinsic));
+            // Prevent verifier error
+            fx.bcx.ins().trap(TrapCode::UnreachableCodeReached);
         }
     }
+    let ret_block = fx.get_block(target);
+    fx.bcx.ins().jump(ret_block, &[]);
 }
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index 629d79d5012..d3868730557 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -57,6 +57,8 @@ mod compiler_builtins;
 mod concurrency_limiter;
 mod config;
 mod constant;
+// FIXME revert back to the external crate with Cranelift 0.93
+mod cranelift_native;
 mod debuginfo;
 mod discriminant;
 mod driver;
@@ -278,12 +280,14 @@ fn build_isa(sess: &Session, backend_config: &BackendConfig) -> Box<dyn isa::Tar
         }
     }
 
-    if target_triple.architecture == target_lexicon::Architecture::X86_64 {
+    if let target_lexicon::Architecture::Aarch64(_) | target_lexicon::Architecture::X86_64 =
+        target_triple.architecture
+    {
         // Windows depends on stack probes to grow the committed part of the stack
         flags_builder.enable("enable_probestack").unwrap();
         flags_builder.set("probestack_strategy", "inline").unwrap();
     } else {
-        // __cranelift_probestack is not provided and inline stack probes are only supported on x86_64
+        // __cranelift_probestack is not provided and inline stack probes are only supported on AArch64 and x86_64
         flags_builder.set("enable_probestack", "false").unwrap();
     }
 
diff --git a/compiler/rustc_codegen_cranelift/src/main_shim.rs b/compiler/rustc_codegen_cranelift/src/main_shim.rs
index c10054e7f0d..3e3b6857134 100644
--- a/compiler/rustc_codegen_cranelift/src/main_shim.rs
+++ b/compiler/rustc_codegen_cranelift/src/main_shim.rs
@@ -46,7 +46,7 @@ pub(crate) fn maybe_create_entry_wrapper(
         is_main_fn: bool,
         sigpipe: u8,
     ) {
-        let main_ret_ty = tcx.fn_sig(rust_main_def_id).output();
+        let main_ret_ty = tcx.fn_sig(rust_main_def_id).no_bound_vars().unwrap().output();
         // Given that `main()` has no arguments,
         // then its return type cannot have
         // late-bound regions, since late-bound
@@ -64,13 +64,20 @@ pub(crate) fn maybe_create_entry_wrapper(
             ],
             returns: vec![AbiParam::new(m.target_config().pointer_type() /*isize*/)],
             call_conv: crate::conv_to_call_conv(
+                tcx.sess,
                 tcx.sess.target.options.entry_abi,
                 m.target_config().default_call_conv,
             ),
         };
 
         let entry_name = tcx.sess.target.options.entry_name.as_ref();
-        let cmain_func_id = m.declare_function(entry_name, Linkage::Export, &cmain_sig).unwrap();
+        let cmain_func_id = match m.declare_function(entry_name, Linkage::Export, &cmain_sig) {
+            Ok(func_id) => func_id,
+            Err(err) => {
+                tcx.sess
+                    .fatal(&format!("entry symbol `{entry_name}` declared multiple times: {err}"));
+            }
+        };
 
         let instance = Instance::mono(tcx, rust_main_def_id).polymorphize(tcx);
 
@@ -162,7 +169,11 @@ pub(crate) fn maybe_create_entry_wrapper(
             bcx.seal_all_blocks();
             bcx.finalize();
         }
-        m.define_function(cmain_func_id, &mut ctx).unwrap();
+
+        if let Err(err) = m.define_function(cmain_func_id, &mut ctx) {
+            tcx.sess.fatal(&format!("entry symbol `{entry_name}` defined multiple times: {err}"));
+        }
+
         unwind_context.add_function(cmain_func_id, &ctx, m.isa());
     }
 }
diff --git a/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs b/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs
index 7f45bbd8f28..26327dca299 100644
--- a/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs
+++ b/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs
@@ -7,7 +7,7 @@ use cranelift_frontend::FunctionBuilder;
 /// otherwise return the given value and false.
 pub(crate) fn maybe_unwrap_bool_not(bcx: &mut FunctionBuilder<'_>, arg: Value) -> (Value, bool) {
     if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
-        match bcx.func.dfg[arg_inst] {
+        match bcx.func.dfg.insts[arg_inst] {
             // This is the lowering of `Rvalue::Not`
             InstructionData::IntCompareImm {
                 opcode: Opcode::IcmpImm,
@@ -34,7 +34,7 @@ pub(crate) fn maybe_known_branch_taken(
         return None;
     };
 
-    match bcx.func.dfg[arg_inst] {
+    match bcx.func.dfg.insts[arg_inst] {
         InstructionData::UnaryImm { opcode: Opcode::Iconst, imm } => {
             if test_zero {
                 Some(imm.bits() == 0)
diff --git a/compiler/rustc_codegen_cranelift/src/value_and_place.rs b/compiler/rustc_codegen_cranelift/src/value_and_place.rs
index fe8af21ac6d..fa06d6c3ba7 100644
--- a/compiler/rustc_codegen_cranelift/src/value_and_place.rs
+++ b/compiler/rustc_codegen_cranelift/src/value_and_place.rs
@@ -514,8 +514,8 @@ impl<'tcx> CPlace<'tcx> {
                 (types::I32, types::F32)
                 | (types::F32, types::I32)
                 | (types::I64, types::F64)
-                | (types::F64, types::I64) => fx.bcx.ins().bitcast(dst_ty, data),
-                _ if src_ty.is_vector() && dst_ty.is_vector() => fx.bcx.ins().bitcast(dst_ty, data),
+                | (types::F64, types::I64) => codegen_bitcast(fx, dst_ty, data),
+                _ if src_ty.is_vector() && dst_ty.is_vector() => codegen_bitcast(fx, dst_ty, data),
                 _ if src_ty.is_vector() || dst_ty.is_vector() => {
                     // FIXME do something more efficient for transmutes between vectors and integers.
                     let stack_slot = fx.bcx.create_sized_stack_slot(StackSlotData {
diff --git a/compiler/rustc_codegen_cranelift/y.rs b/compiler/rustc_codegen_cranelift/y.rs
index 02e1e21ade1..fd825d02e35 100755
--- a/compiler/rustc_codegen_cranelift/y.rs
+++ b/compiler/rustc_codegen_cranelift/y.rs
@@ -3,7 +3,7 @@
 # This block is ignored by rustc
 set -e
 echo "[BUILD] y.rs" 1>&2
-rustc $0 -o ${0/.rs/.bin} -Cdebuginfo=1 --edition 2021
+rustc $0 -o ${0/.rs/.bin} -Cdebuginfo=1 --edition 2021 -Cpanic=abort
 exec ${0/.rs/.bin} $@
 */
 
diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs
index a92242b2615..e88c12716ec 100644
--- a/compiler/rustc_codegen_gcc/src/builder.rs
+++ b/compiler/rustc_codegen_gcc/src/builder.rs
@@ -709,7 +709,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
                         bx.range_metadata(load, vr);
                     }
                 }
-                abi::Pointer if vr.start < vr.end && !vr.contains(0) => {
+                abi::Pointer(_) if vr.start < vr.end && !vr.contains(0) => {
                     bx.nonnull_metadata(load);
                 }
                 _ => {}
diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs
index 0afc56b4494..c939da9cec3 100644
--- a/compiler/rustc_codegen_gcc/src/common.rs
+++ b/compiler/rustc_codegen_gcc/src/common.rs
@@ -211,7 +211,7 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                 let base_addr = self.const_bitcast(base_addr, self.usize_type);
                 let offset = self.context.new_rvalue_from_long(self.usize_type, offset.bytes() as i64);
                 let ptr = self.const_bitcast(base_addr + offset, ptr_type);
-                if layout.primitive() != Pointer {
+                if !matches!(layout.primitive(), Pointer(_)) {
                     self.const_bitcast(ptr.dereference(None).to_rvalue(), ty)
                 }
                 else {
diff --git a/compiler/rustc_codegen_gcc/src/consts.rs b/compiler/rustc_codegen_gcc/src/consts.rs
index ea8ab761146..dc41cb761b5 100644
--- a/compiler/rustc_codegen_gcc/src/consts.rs
+++ b/compiler/rustc_codegen_gcc/src/consts.rs
@@ -322,13 +322,16 @@ pub fn const_alloc_to_gcc<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, alloc: ConstAl
             )
             .expect("const_alloc_to_llvm: could not read relocation pointer")
             as u64;
+
+        let address_space = cx.tcx.global_alloc(alloc_id).address_space(cx);
+
         llvals.push(cx.scalar_to_backend(
             InterpScalar::from_pointer(
                 interpret::Pointer::new(alloc_id, Size::from_bytes(ptr_offset)),
                 &cx.tcx,
             ),
-            abi::Scalar::Initialized { value: Primitive::Pointer, valid_range: WrappingRange::full(dl.pointer_size) },
-            cx.type_i8p(),
+            abi::Scalar::Initialized { value: Primitive::Pointer(address_space), valid_range: WrappingRange::full(dl.pointer_size) },
+            cx.type_i8p_ext(address_space),
         ));
         next_offset = offset + pointer_size;
     }
diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs
index 524d10fb5e2..1326af670cd 100644
--- a/compiler/rustc_codegen_gcc/src/type_of.rs
+++ b/compiler/rustc_codegen_gcc/src/type_of.rs
@@ -253,7 +253,7 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
             Int(i, false) => cx.type_from_unsigned_integer(i),
             F32 => cx.type_f32(),
             F64 => cx.type_f64(),
-            Pointer => {
+            Pointer(address_space) => {
                 // If we know the alignment, pick something better than i8.
                 let pointee =
                     if let Some(pointee) = self.pointee_info_at(cx, offset) {
@@ -262,7 +262,7 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
                     else {
                         cx.type_i8()
                     };
-                cx.type_ptr_to(pointee)
+                cx.type_ptr_to_ext(pointee, address_space)
             }
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index 52c8b51796c..d9f8170a3cf 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -849,6 +849,7 @@ fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &'
 /// Helper function to get the LLVM type for a Scalar. Pointers are returned as
 /// the equivalent integer type.
 fn llvm_asm_scalar_type<'ll>(cx: &CodegenCx<'ll, '_>, scalar: Scalar) -> &'ll Type {
+    let dl = &cx.tcx.data_layout;
     match scalar.primitive() {
         Primitive::Int(Integer::I8, _) => cx.type_i8(),
         Primitive::Int(Integer::I16, _) => cx.type_i16(),
@@ -856,7 +857,8 @@ fn llvm_asm_scalar_type<'ll>(cx: &CodegenCx<'ll, '_>, scalar: Scalar) -> &'ll Ty
         Primitive::Int(Integer::I64, _) => cx.type_i64(),
         Primitive::F32 => cx.type_f32(),
         Primitive::F64 => cx.type_f64(),
-        Primitive::Pointer => cx.type_isize(),
+        // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+        Primitive::Pointer(_) => cx.type_from_integer(dl.ptr_sized_integer()),
         _ => unreachable!(),
     }
 }
@@ -868,6 +870,7 @@ fn llvm_fixup_input<'ll, 'tcx>(
     reg: InlineAsmRegClass,
     layout: &TyAndLayout<'tcx>,
 ) -> &'ll Value {
+    let dl = &bx.tcx.data_layout;
     match (reg, layout.abi) {
         (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg), Abi::Scalar(s)) => {
             if let Primitive::Int(Integer::I8, _) = s.primitive() {
@@ -881,8 +884,10 @@ fn llvm_fixup_input<'ll, 'tcx>(
             let elem_ty = llvm_asm_scalar_type(bx.cx, s);
             let count = 16 / layout.size.bytes();
             let vec_ty = bx.cx.type_vector(elem_ty, count);
-            if let Primitive::Pointer = s.primitive() {
-                value = bx.ptrtoint(value, bx.cx.type_isize());
+            // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+            if let Primitive::Pointer(_) = s.primitive() {
+                let t = bx.type_from_integer(dl.ptr_sized_integer());
+                value = bx.ptrtoint(value, t);
             }
             bx.insert_element(bx.const_undef(vec_ty), value, bx.const_i32(0))
         }
@@ -958,7 +963,7 @@ fn llvm_fixup_output<'ll, 'tcx>(
         }
         (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), Abi::Scalar(s)) => {
             value = bx.extract_element(value, bx.const_i32(0));
-            if let Primitive::Pointer = s.primitive() {
+            if let Primitive::Pointer(_) = s.primitive() {
                 value = bx.inttoptr(value, layout.llvm_type(bx.cx));
             }
             value
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 95baa95b021..54ac7a46cf2 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -441,7 +441,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // the WebAssembly specification, which has this feature. This won't be
         // needed when LLVM enables this `multivalue` feature by default.
         if !cx.tcx.is_closure(instance.def_id()) {
-            let abi = cx.tcx.fn_sig(instance.def_id()).abi();
+            let abi = cx.tcx.fn_sig(instance.def_id()).skip_binder().abi();
             if abi == Abi::Wasm {
                 function_features.push("+multivalue".to_string());
             }
diff --git a/compiler/rustc_codegen_llvm/src/back/archive.rs b/compiler/rustc_codegen_llvm/src/back/archive.rs
index 426f57c0608..58ca87524de 100644
--- a/compiler/rustc_codegen_llvm/src/back/archive.rs
+++ b/compiler/rustc_codegen_llvm/src/back/archive.rs
@@ -15,8 +15,8 @@ use crate::errors::{
 use crate::llvm::archive_ro::{ArchiveRO, Child};
 use crate::llvm::{self, ArchiveKind, LLVMMachineType, LLVMRustCOFFShortExport};
 use rustc_codegen_ssa::back::archive::{
-    get_native_object_symbols, ArArchiveBuilder, ArchiveBuildFailure, ArchiveBuilder,
-    ArchiveBuilderBuilder, UnknownArchiveKind,
+    get_native_object_symbols, try_extract_macho_fat_archive, ArArchiveBuilder,
+    ArchiveBuildFailure, ArchiveBuilder, ArchiveBuilderBuilder, UnknownArchiveKind,
 };
 
 use rustc_session::cstore::DllImport;
@@ -66,7 +66,13 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
         archive: &Path,
         skip: Box<dyn FnMut(&str) -> bool + 'static>,
     ) -> io::Result<()> {
-        let archive_ro = match ArchiveRO::open(archive) {
+        let mut archive = archive.to_path_buf();
+        if self.sess.target.llvm_target.contains("-apple-macosx") {
+            if let Some(new_archive) = try_extract_macho_fat_archive(&self.sess, &archive)? {
+                archive = new_archive
+            }
+        }
+        let archive_ro = match ArchiveRO::open(&archive) {
             Ok(ar) => ar,
             Err(e) => return Err(io::Error::new(io::ErrorKind::Other, e)),
         };
@@ -74,7 +80,7 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
             return Ok(());
         }
         self.additions.push(Addition::Archive {
-            path: archive.to_path_buf(),
+            path: archive,
             archive: archive_ro,
             skip: Box::new(skip),
         });
@@ -102,7 +108,9 @@ pub struct LlvmArchiveBuilderBuilder;
 
 impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder<'a> + 'a> {
-        if sess.target.arch == "wasm32" || sess.target.arch == "wasm64" {
+        // FIXME use ArArchiveBuilder on most targets again once reading thin archives is
+        // implemented
+        if true || sess.target.arch == "wasm32" || sess.target.arch == "wasm64" {
             Box::new(LlvmArchiveBuilder { sess, additions: Vec::new() })
         } else {
             Box::new(ArArchiveBuilder::new(sess, get_llvm_object_symbols))
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 5e98deae48a..0f33b985489 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -511,7 +511,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
                         bx.range_metadata(load, scalar.valid_range(bx));
                     }
                 }
-                abi::Pointer => {
+                abi::Pointer(_) => {
                     if !scalar.valid_range(bx).contains(0) {
                         bx.nonnull_metadata(load);
                     }
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index acee9134fb9..edb1c160626 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -236,7 +236,7 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             Scalar::Int(int) => {
                 let data = int.assert_bits(layout.size(self));
                 let llval = self.const_uint_big(self.type_ix(bitsize), data);
-                if layout.primitive() == Pointer {
+                if matches!(layout.primitive(), Pointer(_)) {
                     unsafe { llvm::LLVMConstIntToPtr(llval, llty) }
                 } else {
                     self.const_bitcast(llval, llty)
@@ -284,7 +284,7 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                         1,
                     )
                 };
-                if layout.primitive() != Pointer {
+                if !matches!(layout.primitive(), Pointer(_)) {
                     unsafe { llvm::LLVMConstPtrToInt(llval, llty) }
                 } else {
                     self.const_bitcast(llval, llty)
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index 16467b614fe..cad3c5d87b7 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -13,7 +13,7 @@ use rustc_codegen_ssa::traits::*;
 use rustc_hir::def_id::DefId;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::mir::interpret::{
-    read_target_uint, Allocation, ConstAllocation, ErrorHandled, GlobalAlloc, InitChunk, Pointer,
+    read_target_uint, Allocation, ConstAllocation, ErrorHandled, InitChunk, Pointer,
     Scalar as InterpScalar,
 };
 use rustc_middle::mir::mono::MonoItem;
@@ -21,9 +21,7 @@ use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::{self, Instance, Ty};
 use rustc_middle::{bug, span_bug};
 use rustc_session::config::Lto;
-use rustc_target::abi::{
-    AddressSpace, Align, HasDataLayout, Primitive, Scalar, Size, WrappingRange,
-};
+use rustc_target::abi::{Align, HasDataLayout, Primitive, Scalar, Size, WrappingRange};
 use std::ops::Range;
 
 pub fn const_alloc_to_llvm<'ll>(cx: &CodegenCx<'ll, '_>, alloc: ConstAllocation<'_>) -> &'ll Value {
@@ -98,12 +96,7 @@ pub fn const_alloc_to_llvm<'ll>(cx: &CodegenCx<'ll, '_>, alloc: ConstAllocation<
         .expect("const_alloc_to_llvm: could not read relocation pointer")
             as u64;
 
-        let address_space = match cx.tcx.global_alloc(alloc_id) {
-            GlobalAlloc::Function(..) => cx.data_layout().instruction_address_space,
-            GlobalAlloc::Static(..) | GlobalAlloc::Memory(..) | GlobalAlloc::VTable(..) => {
-                AddressSpace::DATA
-            }
-        };
+        let address_space = cx.tcx.global_alloc(alloc_id).address_space(cx);
 
         llvals.push(cx.scalar_to_backend(
             InterpScalar::from_pointer(
@@ -111,7 +104,7 @@ pub fn const_alloc_to_llvm<'ll>(cx: &CodegenCx<'ll, '_>, alloc: ConstAllocation<
                 &cx.tcx,
             ),
             Scalar::Initialized {
-                value: Primitive::Pointer,
+                value: Primitive::Pointer(address_space),
                 valid_range: WrappingRange::full(dl.pointer_size),
             },
             cx.type_i8p_ext(address_space),
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index d9ccba07a34..32cd3a4efa2 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -191,7 +191,7 @@ pub unsafe fn create_module<'ll>(
         //
         // FIXME(#34960)
         let cfg_llvm_root = option_env!("CFG_LLVM_ROOT").unwrap_or("");
-        let custom_llvm_used = cfg_llvm_root.trim() != "";
+        let custom_llvm_used = !cfg_llvm_root.trim().is_empty();
 
         if !custom_llvm_used && target_data_layout != llvm_data_layout {
             bug!(
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index 22c61248b7d..240a9d2f371 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -1,6 +1,5 @@
 use crate::common::CodegenCx;
 use crate::coverageinfo;
-use crate::errors::InstrumentCoverageRequiresLLVM12;
 use crate::llvm;
 
 use llvm::coverageinfo::CounterMappingRegion;
@@ -19,8 +18,8 @@ use std::ffi::CString;
 
 /// Generates and exports the Coverage Map.
 ///
-/// Rust Coverage Map generation supports LLVM Coverage Mapping Format versions
-/// 5 (LLVM 12, only) and 6 (zero-based encoded as 4 and 5, respectively), as defined at
+/// Rust Coverage Map generation supports LLVM Coverage Mapping Format version
+/// 6 (zero-based encoded as 5), as defined at
 /// [LLVM Code Coverage Mapping Format](https://github.com/rust-lang/llvm-project/blob/rustc/13.0-2021-09-30/llvm/docs/CoverageMappingFormat.rst#llvm-code-coverage-mapping-format).
 /// These versions are supported by the LLVM coverage tools (`llvm-profdata` and `llvm-cov`)
 /// bundled with Rust's fork of LLVM.
@@ -33,13 +32,10 @@ use std::ffi::CString;
 pub fn finalize(cx: &CodegenCx<'_, '_>) {
     let tcx = cx.tcx;
 
-    // Ensure the installed version of LLVM supports at least Coverage Map
-    // Version 5 (encoded as a zero-based value: 4), which was introduced with
-    // LLVM 12.
+    // Ensure the installed version of LLVM supports Coverage Map Version 6
+    // (encoded as a zero-based value: 5), which was introduced with LLVM 13.
     let version = coverageinfo::mapping_version();
-    if version < 4 {
-        tcx.sess.emit_fatal(InstrumentCoverageRequiresLLVM12);
-    }
+    assert_eq!(version, 5, "The `CoverageMappingVersion` exposed by `llvm-wrapper` is out of sync");
 
     debug!("Generating coverage map for CodegenUnit: `{}`", cx.codegen_unit.name());
 
@@ -61,7 +57,7 @@ pub fn finalize(cx: &CodegenCx<'_, '_>) {
         return;
     }
 
-    let mut mapgen = CoverageMapGenerator::new(tcx, version);
+    let mut mapgen = CoverageMapGenerator::new(tcx);
 
     // Encode coverage mappings and generate function records
     let mut function_data = Vec::new();
@@ -124,25 +120,18 @@ struct CoverageMapGenerator {
 }
 
 impl CoverageMapGenerator {
-    fn new(tcx: TyCtxt<'_>, version: u32) -> Self {
+    fn new(tcx: TyCtxt<'_>) -> Self {
         let mut filenames = FxIndexSet::default();
-        if version >= 5 {
-            // LLVM Coverage Mapping Format version 6 (zero-based encoded as 5)
-            // requires setting the first filename to the compilation directory.
-            // Since rustc generates coverage maps with relative paths, the
-            // compilation directory can be combined with the relative paths
-            // to get absolute paths, if needed.
-            let working_dir = tcx
-                .sess
-                .opts
-                .working_dir
-                .remapped_path_if_available()
-                .to_string_lossy()
-                .to_string();
-            let c_filename =
-                CString::new(working_dir).expect("null error converting filename to C string");
-            filenames.insert(c_filename);
-        }
+        // LLVM Coverage Mapping Format version 6 (zero-based encoded as 5)
+        // requires setting the first filename to the compilation directory.
+        // Since rustc generates coverage maps with relative paths, the
+        // compilation directory can be combined with the relative paths
+        // to get absolute paths, if needed.
+        let working_dir =
+            tcx.sess.opts.working_dir.remapped_path_if_available().to_string_lossy().to_string();
+        let c_filename =
+            CString::new(working_dir).expect("null error converting filename to C string");
+        filenames.insert(c_filename);
         Self { filenames }
     }
 
@@ -306,9 +295,8 @@ fn add_unused_functions(cx: &CodegenCx<'_, '_>) {
                 DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Generator
             ) {
                 return None;
-            } else if ignore_unused_generics
-                && tcx.generics_of(def_id).requires_monomorphization(tcx)
-            {
+            }
+            if ignore_unused_generics && tcx.generics_of(def_id).requires_monomorphization(tcx) {
                 return None;
             }
             Some(local_def_id.to_def_id())
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index b6eb5ee183f..f73bbf3d22b 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1499,6 +1499,11 @@ pub fn create_vtable_di_node<'ll, 'tcx>(
         return;
     }
 
+    // When full debuginfo is enabled, we want to try and prevent vtables from being
+    // merged. Otherwise debuggers will have a hard time mapping from dyn pointer
+    // to concrete type.
+    llvm::SetUnnamedAddress(vtable, llvm::UnnamedAddr::No);
+
     let vtable_name =
         compute_debuginfo_vtable_name(cx.tcx, ty, poly_trait_ref, VTableNameKind::GlobalVariable);
     let vtable_type_di_node = build_vtable_type_di_node(cx, ty, poly_trait_ref);
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
index 564ab351bd4..54e850f2599 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
@@ -122,7 +122,8 @@ fn tag_base_type<'ll, 'tcx>(
                 Primitive::Int(t, _) => t,
                 Primitive::F32 => Integer::I32,
                 Primitive::F64 => Integer::I64,
-                Primitive::Pointer => {
+                // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+                Primitive::Pointer(_) => {
                     // If the niche is the NULL value of a reference, then `discr_enum_ty` will be
                     // a RawPtr. CodeView doesn't know what to do with enums whose base type is a
                     // pointer so we fix this up to just be `usize`.
diff --git a/compiler/rustc_codegen_llvm/src/errors.rs b/compiler/rustc_codegen_llvm/src/errors.rs
index b4620997242..001d1ce93d8 100644
--- a/compiler/rustc_codegen_llvm/src/errors.rs
+++ b/compiler/rustc_codegen_llvm/src/errors.rs
@@ -40,10 +40,6 @@ pub(crate) struct ErrorCreatingImportLibrary<'a> {
 }
 
 #[derive(Diagnostic)]
-#[diag(codegen_llvm_instrument_coverage_requires_llvm_12)]
-pub(crate) struct InstrumentCoverageRequiresLLVM12;
-
-#[derive(Diagnostic)]
 #[diag(codegen_llvm_symbol_already_defined)]
 pub(crate) struct SymbolAlreadyDefined<'a> {
     #[primary_span]
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index a6a75eff9a3..dd89c4c59c1 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -149,7 +149,7 @@ impl<'ll, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                                     emit_va_arg(self, args[0], ret_ty)
                                 }
                             }
-                            Primitive::F64 | Primitive::Pointer => {
+                            Primitive::F64 | Primitive::Pointer(_) => {
                                 emit_va_arg(self, args[0], ret_ty)
                             }
                             // `va_arg` should never be used with the return type f32.
diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs
index 75cd5df9723..c73d233b767 100644
--- a/compiler/rustc_codegen_llvm/src/type_of.rs
+++ b/compiler/rustc_codegen_llvm/src/type_of.rs
@@ -7,7 +7,7 @@ use rustc_middle::bug;
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
 use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
 use rustc_middle::ty::{self, Ty, TypeVisitable};
-use rustc_target::abi::{Abi, AddressSpace, Align, FieldsShape};
+use rustc_target::abi::{Abi, Align, FieldsShape};
 use rustc_target::abi::{Int, Pointer, F32, F64};
 use rustc_target::abi::{PointeeInfo, Scalar, Size, TyAbiInterface, Variants};
 use smallvec::{smallvec, SmallVec};
@@ -312,14 +312,13 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
             Int(i, _) => cx.type_from_integer(i),
             F32 => cx.type_f32(),
             F64 => cx.type_f64(),
-            Pointer => {
+            Pointer(address_space) => {
                 // If we know the alignment, pick something better than i8.
-                let (pointee, address_space) =
-                    if let Some(pointee) = self.pointee_info_at(cx, offset) {
-                        (cx.type_pointee_for_align(pointee.align), pointee.address_space)
-                    } else {
-                        (cx.type_i8(), AddressSpace::DATA)
-                    };
+                let pointee = if let Some(pointee) = self.pointee_info_at(cx, offset) {
+                    cx.type_pointee_for_align(pointee.align)
+                } else {
+                    cx.type_i8()
+                };
                 cx.type_ptr_to_ext(pointee, address_space)
             }
         }
diff --git a/compiler/rustc_codegen_ssa/src/back/archive.rs b/compiler/rustc_codegen_ssa/src/back/archive.rs
index 6eb120157da..d3cd085cfb6 100644
--- a/compiler/rustc_codegen_ssa/src/back/archive.rs
+++ b/compiler/rustc_codegen_ssa/src/back/archive.rs
@@ -14,7 +14,7 @@ use tempfile::Builder as TempFileBuilder;
 
 use std::error::Error;
 use std::fs::File;
-use std::io;
+use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 
 // Re-exporting for rustc_codegen_llvm::back::archive
@@ -116,11 +116,12 @@ impl<'a> ArArchiveBuilder<'a> {
     }
 }
 
-fn try_filter_fat_archs<'a>(
+fn try_filter_fat_archs(
     archs: object::read::Result<&[impl FatArch]>,
     target_arch: object::Architecture,
-    archive_map_data: &'a [u8],
-) -> io::Result<Option<(&'a [u8], u64)>> {
+    archive_path: &Path,
+    archive_map_data: &[u8],
+) -> io::Result<Option<PathBuf>> {
     let archs = archs.map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
 
     let desired = match archs.iter().find(|a| a.architecture() == target_arch) {
@@ -128,30 +129,38 @@ fn try_filter_fat_archs<'a>(
         None => return Ok(None),
     };
 
-    Ok(Some((
+    let (mut new_f, extracted_path) = tempfile::Builder::new()
+        .suffix(archive_path.file_name().unwrap())
+        .tempfile()?
+        .keep()
+        .unwrap();
+
+    new_f.write_all(
         desired.data(archive_map_data).map_err(|e| io::Error::new(io::ErrorKind::Other, e))?,
-        desired.offset().into(),
-    )))
+    )?;
+
+    Ok(Some(extracted_path))
 }
 
-pub fn try_extract_macho_fat_archive<'a>(
+pub fn try_extract_macho_fat_archive(
     sess: &Session,
-    archive_bytes: &'a [u8],
-) -> io::Result<Option<(&'a [u8], u64)>> {
+    archive_path: &Path,
+) -> io::Result<Option<PathBuf>> {
+    let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
     let target_arch = match sess.target.arch.as_ref() {
         "aarch64" => object::Architecture::Aarch64,
         "x86_64" => object::Architecture::X86_64,
         _ => return Ok(None),
     };
 
-    match object::macho::FatHeader::parse(archive_bytes) {
+    match object::macho::FatHeader::parse(&*archive_map) {
         Ok(h) if h.magic.get(object::endian::BigEndian) == object::macho::FAT_MAGIC => {
-            let archs = object::macho::FatHeader::parse_arch32(archive_bytes);
-            try_filter_fat_archs(archs, target_arch, archive_bytes)
+            let archs = object::macho::FatHeader::parse_arch32(&*archive_map);
+            try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
         }
         Ok(h) if h.magic.get(object::endian::BigEndian) == object::macho::FAT_MAGIC_64 => {
-            let archs = object::macho::FatHeader::parse_arch64(archive_bytes);
-            try_filter_fat_archs(archs, target_arch, archive_bytes)
+            let archs = object::macho::FatHeader::parse_arch64(&*archive_map);
+            try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
         }
         // Not a FatHeader at all, just return None.
         _ => Ok(None),
@@ -164,24 +173,21 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
         archive_path: &Path,
         mut skip: Box<dyn FnMut(&str) -> bool + 'static>,
     ) -> io::Result<()> {
-        let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
+        let mut archive_path = archive_path.to_path_buf();
+        if self.sess.target.llvm_target.contains("-apple-macosx") {
+            if let Some(new_archive_path) =
+                try_extract_macho_fat_archive(&self.sess, &archive_path)?
+            {
+                archive_path = new_archive_path
+            }
+        }
+
         if self.src_archives.iter().any(|archive| archive.0 == archive_path) {
             return Ok(());
         }
 
-        let (archive_bytes, offset) = if self.sess.target.llvm_target.contains("-apple-macosx") {
-            if let Some((sub_archive, archive_offset)) =
-                try_extract_macho_fat_archive(&self.sess, &*archive_map)?
-            {
-                (sub_archive, Some(archive_offset))
-            } else {
-                (&*archive_map, None)
-            }
-        } else {
-            (&*archive_map, None)
-        };
-
-        let archive = ArchiveFile::parse(&*archive_bytes)
+        let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
+        let archive = ArchiveFile::parse(&*archive_map)
             .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
         let archive_index = self.src_archives.len();
 
@@ -190,13 +196,9 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
             let file_name = String::from_utf8(entry.name().to_vec())
                 .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
             if !skip(&file_name) {
-                let mut range = entry.file_range();
-                if let Some(offset) = offset {
-                    range.0 += offset;
-                }
                 self.entries.push((
                     file_name.into_bytes(),
-                    ArchiveEntry::FromArchive { archive_index, file_range: range },
+                    ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
                 ));
             }
         }
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index b148e4185a6..4ac7bea03eb 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -599,7 +599,8 @@ fn link_dwarf_object<'a>(
     cg_results: &CodegenResults,
     executable_out_filename: &Path,
 ) {
-    let dwp_out_filename = executable_out_filename.with_extension("dwp");
+    let mut dwp_out_filename = executable_out_filename.to_path_buf().into_os_string();
+    dwp_out_filename.push(".dwp");
     debug!(?dwp_out_filename, ?executable_out_filename);
 
     #[derive(Default)]
@@ -1300,12 +1301,6 @@ fn preserve_objects_for_their_debuginfo(sess: &Session) -> (bool, bool) {
         return (false, false);
     }
 
-    // If we're only producing artifacts that are archives, no need to preserve
-    // the objects as they're losslessly contained inside the archives.
-    if sess.crate_types().iter().all(|&x| x.is_archive()) {
-        return (false, false);
-    }
-
     match (sess.split_debuginfo(), sess.opts.unstable_opts.split_dwarf_kind) {
         // If there is no split debuginfo then do not preserve objects.
         (SplitDebuginfo::Off, _) => (false, false),
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 32d3cfe6fc6..02b502d948c 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -436,7 +436,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             cx.type_func(&[], cx.type_int())
         };
 
-        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
+        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).no_bound_vars().unwrap().output();
         // Given that `main()` has no arguments,
         // then its return type cannot have
         // late-bound regions, since late-bound
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 8808ad2dcd1..87b819ebc98 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -214,7 +214,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
             }
         } else if attr.has_name(sym::cmse_nonsecure_entry) {
             if validate_fn_only_attr(attr.span)
-                && !matches!(tcx.fn_sig(did).abi(), abi::Abi::C { .. })
+                && !matches!(tcx.fn_sig(did).skip_binder().abi(), abi::Abi::C { .. })
             {
                 struct_span_err!(
                     tcx.sess,
@@ -234,7 +234,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
         } else if attr.has_name(sym::track_caller) {
             if !tcx.is_closure(did.to_def_id())
                 && validate_fn_only_attr(attr.span)
-                && tcx.fn_sig(did).abi() != abi::Abi::Rust
+                && tcx.fn_sig(did).skip_binder().abi() != abi::Abi::Rust
             {
                 struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI")
                     .emit();
@@ -266,7 +266,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
             }
         } else if attr.has_name(sym::target_feature) {
             if !tcx.is_closure(did.to_def_id())
-                && tcx.fn_sig(did).unsafety() == hir::Unsafety::Normal
+                && tcx.fn_sig(did).skip_binder().unsafety() == hir::Unsafety::Normal
             {
                 if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc {
                     // The `#[target_feature]` attribute is allowed on
diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
index 1599ccbb259..b0e007ce009 100644
--- a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
+++ b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -414,6 +414,7 @@ fn push_debuginfo_type_name<'tcx>(
         | ty::Placeholder(..)
         | ty::Alias(..)
         | ty::Bound(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::GeneratorWitness(..) => {
             bug!(
                 "debuginfo: Trying to create type name for \
diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
index dd1ac2c74ae..95aad10fdb0 100644
--- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
@@ -36,7 +36,7 @@ pub fn non_ssa_locals<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
     // Arguments get assigned to by means of the function being called
     for arg in mir.args_iter() {
-        analyzer.assign(arg, mir::START_BLOCK.start_location());
+        analyzer.assign(arg, DefLocation::Argument);
     }
 
     // If there exists a local definition that dominates all uses of that local,
@@ -64,7 +64,22 @@ enum LocalKind {
     /// A scalar or a scalar pair local that is neither defined nor used.
     Unused,
     /// A scalar or a scalar pair local with a single definition that dominates all uses.
-    SSA(mir::Location),
+    SSA(DefLocation),
+}
+
+#[derive(Copy, Clone, PartialEq, Eq)]
+enum DefLocation {
+    Argument,
+    Body(Location),
+}
+
+impl DefLocation {
+    fn dominates(self, location: Location, dominators: &Dominators<mir::BasicBlock>) -> bool {
+        match self {
+            DefLocation::Argument => true,
+            DefLocation::Body(def) => def.successor_within_block().dominates(location, dominators),
+        }
+    }
 }
 
 struct LocalAnalyzer<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> {
@@ -74,17 +89,13 @@ struct LocalAnalyzer<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> {
 }
 
 impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> LocalAnalyzer<'mir, 'a, 'tcx, Bx> {
-    fn assign(&mut self, local: mir::Local, location: Location) {
+    fn assign(&mut self, local: mir::Local, location: DefLocation) {
         let kind = &mut self.locals[local];
         match *kind {
             LocalKind::ZST => {}
             LocalKind::Memory => {}
-            LocalKind::Unused => {
-                *kind = LocalKind::SSA(location);
-            }
-            LocalKind::SSA(_) => {
-                *kind = LocalKind::Memory;
-            }
+            LocalKind::Unused => *kind = LocalKind::SSA(location),
+            LocalKind::SSA(_) => *kind = LocalKind::Memory,
         }
     }
 
@@ -166,7 +177,7 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
         debug!("visit_assign(place={:?}, rvalue={:?})", place, rvalue);
 
         if let Some(local) = place.as_local() {
-            self.assign(local, location);
+            self.assign(local, DefLocation::Body(location));
             if self.locals[local] != LocalKind::Memory {
                 let decl_span = self.fx.mir.local_decls[local].source_info.span;
                 if !self.fx.rvalue_creates_operand(rvalue, decl_span) {
@@ -189,7 +200,7 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
         match context {
             PlaceContext::MutatingUse(MutatingUseContext::Call)
             | PlaceContext::MutatingUse(MutatingUseContext::Yield) => {
-                self.assign(local, location);
+                self.assign(local, DefLocation::Body(location));
             }
 
             PlaceContext::NonUse(_) | PlaceContext::MutatingUse(MutatingUseContext::Retag) => {}
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 978aff511bf..2623a650e07 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -39,7 +39,6 @@ enum MergingSucc {
 struct TerminatorCodegenHelper<'tcx> {
     bb: mir::BasicBlock,
     terminator: &'tcx mir::Terminator<'tcx>,
-    funclet_bb: Option<mir::BasicBlock>,
 }
 
 impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
@@ -49,28 +48,24 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         &self,
         fx: &'b mut FunctionCx<'a, 'tcx, Bx>,
     ) -> Option<&'b Bx::Funclet> {
-        let funclet_bb = self.funclet_bb?;
-        if base::wants_msvc_seh(fx.cx.tcx().sess) {
-            // If `landing_pad_for` hasn't been called yet to create the `Funclet`,
-            // it has to be now. This may not seem necessary, as RPO should lead
-            // to all the unwind edges being visited (and so to `landing_pad_for`
-            // getting called for them), before building any of the blocks inside
-            // the funclet itself - however, if MIR contains edges that end up not
-            // being needed in the LLVM IR after monomorphization, the funclet may
-            // be unreachable, and we don't have yet a way to skip building it in
-            // such an eventuality (which may be a better solution than this).
-            if fx.funclets[funclet_bb].is_none() {
-                fx.landing_pad_for(funclet_bb);
-            }
-
-            Some(
-                fx.funclets[funclet_bb]
-                    .as_ref()
-                    .expect("landing_pad_for didn't also create funclets entry"),
-            )
-        } else {
-            None
+        let cleanup_kinds = (&fx.cleanup_kinds).as_ref()?;
+        let funclet_bb = cleanup_kinds[self.bb].funclet_bb(self.bb)?;
+        // If `landing_pad_for` hasn't been called yet to create the `Funclet`,
+        // it has to be now. This may not seem necessary, as RPO should lead
+        // to all the unwind edges being visited (and so to `landing_pad_for`
+        // getting called for them), before building any of the blocks inside
+        // the funclet itself - however, if MIR contains edges that end up not
+        // being needed in the LLVM IR after monomorphization, the funclet may
+        // be unreachable, and we don't have yet a way to skip building it in
+        // such an eventuality (which may be a better solution than this).
+        if fx.funclets[funclet_bb].is_none() {
+            fx.landing_pad_for(funclet_bb);
         }
+        Some(
+            fx.funclets[funclet_bb]
+                .as_ref()
+                .expect("landing_pad_for didn't also create funclets entry"),
+        )
     }
 
     /// Get a basic block (creating it if necessary), possibly with cleanup
@@ -104,23 +99,24 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         fx: &mut FunctionCx<'a, 'tcx, Bx>,
         target: mir::BasicBlock,
     ) -> (bool, bool) {
-        let target_funclet = fx.cleanup_kinds[target].funclet_bb(target);
-        let (needs_landing_pad, is_cleanupret) = match (self.funclet_bb, target_funclet) {
-            (None, None) => (false, false),
-            (None, Some(_)) => (true, false),
-            (Some(_), None) => {
-                let span = self.terminator.source_info.span;
-                span_bug!(span, "{:?} - jump out of cleanup?", self.terminator);
-            }
-            (Some(f), Some(t_f)) => {
-                if f == t_f || !base::wants_msvc_seh(fx.cx.tcx().sess) {
-                    (false, false)
-                } else {
-                    (true, true)
+        if let Some(ref cleanup_kinds) = fx.cleanup_kinds {
+            let funclet_bb = cleanup_kinds[self.bb].funclet_bb(self.bb);
+            let target_funclet = cleanup_kinds[target].funclet_bb(target);
+            let (needs_landing_pad, is_cleanupret) = match (funclet_bb, target_funclet) {
+                (None, None) => (false, false),
+                (None, Some(_)) => (true, false),
+                (Some(f), Some(t_f)) => (f != t_f, f != t_f),
+                (Some(_), None) => {
+                    let span = self.terminator.source_info.span;
+                    span_bug!(span, "{:?} - jump out of cleanup?", self.terminator);
                 }
-            }
-        };
-        (needs_landing_pad, is_cleanupret)
+            };
+            (needs_landing_pad, is_cleanupret)
+        } else {
+            let needs_landing_pad = !fx.mir[self.bb].is_cleanup && fx.mir[target].is_cleanup;
+            let is_cleanupret = false;
+            (needs_landing_pad, is_cleanupret)
+        }
     }
 
     fn funclet_br<Bx: BuilderMethods<'a, 'tcx>>(
@@ -678,8 +674,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             let layout = bx.layout_of(ty);
             let do_panic = match intrinsic {
                 Inhabited => layout.abi.is_uninhabited(),
-                ZeroValid => !bx.tcx().permits_zero_init(layout),
-                MemUninitializedValid => !bx.tcx().permits_uninit_init(layout),
+                ZeroValid => !bx.tcx().permits_zero_init(bx.param_env().and(layout)),
+                MemUninitializedValid => !bx.tcx().permits_uninit_init(bx.param_env().and(layout)),
             };
             Some(if do_panic {
                 let msg_str = with_no_visible_paths!({
@@ -1253,9 +1249,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     ) -> MergingSucc {
         debug!("codegen_terminator: {:?}", terminator);
 
-        // Create the cleanup bundle, if needed.
-        let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb);
-        let helper = TerminatorCodegenHelper { bb, terminator, funclet_bb };
+        let helper = TerminatorCodegenHelper { bb, terminator };
 
         let mergeable_succ = || {
             // Note: any call to `switch_to_block` will invalidate a `true` value
@@ -1801,8 +1795,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         match (src.layout.abi, dst.layout.abi) {
             (abi::Abi::Scalar(src_scalar), abi::Abi::Scalar(dst_scalar)) => {
                 // HACK(eddyb) LLVM doesn't like `bitcast`s between pointers and non-pointers.
-                let src_is_ptr = src_scalar.primitive() == abi::Pointer;
-                let dst_is_ptr = dst_scalar.primitive() == abi::Pointer;
+                let src_is_ptr = matches!(src_scalar.primitive(), abi::Pointer(_));
+                let dst_is_ptr = matches!(dst_scalar.primitive(), abi::Pointer(_));
                 if src_is_ptr == dst_is_ptr {
                     assert_eq!(src.layout.size, dst.layout.size);
 
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index 79c66a955e7..bb265b8289e 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -1,3 +1,4 @@
+use crate::base;
 use crate::traits::*;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ErrorHandled;
@@ -58,7 +59,7 @@ pub struct FunctionCx<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> {
     cached_llbbs: IndexVec<mir::BasicBlock, CachedLlbb<Bx::BasicBlock>>,
 
     /// The funclet status of each basic block
-    cleanup_kinds: IndexVec<mir::BasicBlock, analyze::CleanupKind>,
+    cleanup_kinds: Option<IndexVec<mir::BasicBlock, analyze::CleanupKind>>,
 
     /// When targeting MSVC, this stores the cleanup info for each funclet BB.
     /// This is initialized at the same time as the `landing_pads` entry for the
@@ -166,7 +167,9 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         start_bx.set_personality_fn(cx.eh_personality());
     }
 
-    let cleanup_kinds = analyze::cleanup_kinds(&mir);
+    let cleanup_kinds =
+        if base::wants_msvc_seh(cx.tcx().sess) { Some(analyze::cleanup_kinds(&mir)) } else { None };
+
     let cached_llbbs: IndexVec<mir::BasicBlock, CachedLlbb<Bx::BasicBlock>> =
         mir.basic_blocks
             .indices()
diff --git a/compiler/rustc_codegen_ssa/src/mir/place.rs b/compiler/rustc_codegen_ssa/src/mir/place.rs
index fbe30154a7c..cf02f59f67b 100644
--- a/compiler/rustc_codegen_ssa/src/mir/place.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/place.rs
@@ -9,7 +9,7 @@ use rustc_middle::mir;
 use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Ty};
-use rustc_target::abi::{Abi, Align, FieldsShape, Int, TagEncoding};
+use rustc_target::abi::{Abi, Align, FieldsShape, Int, Pointer, TagEncoding};
 use rustc_target::abi::{VariantIdx, Variants};
 
 #[derive(Copy, Clone, Debug)]
@@ -209,6 +209,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         bx: &mut Bx,
         cast_to: Ty<'tcx>,
     ) -> V {
+        let dl = &bx.tcx().data_layout;
         let cast_to_layout = bx.cx().layout_of(cast_to);
         let cast_to_size = cast_to_layout.layout.size();
         let cast_to = bx.cx().immediate_backend_type(cast_to_layout);
@@ -250,12 +251,14 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
             TagEncoding::Niche { untagged_variant, ref niche_variants, niche_start } => {
                 // Cast to an integer so we don't have to treat a pointer as a
                 // special case.
-                let (tag, tag_llty) = if tag_scalar.primitive().is_ptr() {
-                    let t = bx.type_isize();
-                    let tag = bx.ptrtoint(tag_imm, t);
-                    (tag, t)
-                } else {
-                    (tag_imm, bx.cx().immediate_backend_type(tag_op.layout))
+                let (tag, tag_llty) = match tag_scalar.primitive() {
+                    // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+                    Pointer(_) => {
+                        let t = bx.type_from_integer(dl.ptr_sized_integer());
+                        let tag = bx.ptrtoint(tag_imm, t);
+                        (tag, t)
+                    }
+                    _ => (tag_imm, bx.cx().immediate_backend_type(tag_op.layout)),
                 };
 
                 let tag_size = tag_scalar.size(bx.cx());
diff --git a/compiler/rustc_codegen_ssa/src/mir/statement.rs b/compiler/rustc_codegen_ssa/src/mir/statement.rs
index 19452c8cdc8..60fbceb344d 100644
--- a/compiler/rustc_codegen_ssa/src/mir/statement.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/statement.rs
@@ -91,6 +91,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::StatementKind::FakeRead(..)
             | mir::StatementKind::Retag { .. }
             | mir::StatementKind::AscribeUserType(..)
+            | mir::StatementKind::ConstEvalCounter
             | mir::StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_const_eval/src/const_eval/fn_queries.rs b/compiler/rustc_const_eval/src/const_eval/fn_queries.rs
index 351c701305a..f92277b1113 100644
--- a/compiler/rustc_const_eval/src/const_eval/fn_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/fn_queries.rs
@@ -66,7 +66,7 @@ fn is_promotable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
                 if cfg!(debug_assertions) && stab.promotable {
                     let sig = tcx.fn_sig(def_id);
                     assert_eq!(
-                        sig.unsafety(),
+                        sig.skip_binder().unsafety(),
                         hir::Unsafety::Normal,
                         "don't mark const unsafe fns as promotable",
                         // https://github.com/rust-lang/rust/pull/53851#issuecomment-418760682
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index 4709514c82e..a5bc121485d 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -561,8 +561,8 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         throw_unsup_format!("pointer arithmetic or comparison is not supported at compile-time");
     }
 
-    fn before_terminator(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
-        // The step limit has already been hit in a previous call to `before_terminator`.
+    fn increment_const_eval_counter(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
+        // The step limit has already been hit in a previous call to `increment_const_eval_counter`.
         if ecx.machine.steps_remaining == 0 {
             return Ok(());
         }
diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
index 498c0087387..c52886b77e6 100644
--- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs
+++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
@@ -151,7 +151,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
         // FIXME(oli-obk): we can probably encode closures just like structs
         | ty::Closure(..)
         | ty::Generator(..)
-        | ty::GeneratorWitness(..) => Err(ValTreeCreationError::NonSupportedType),
+        | ty::GeneratorWitness(..) |ty::GeneratorWitnessMIR(..)=> Err(ValTreeCreationError::NonSupportedType),
     }
 }
 
@@ -314,6 +314,7 @@ pub fn valtree_to_const_value<'tcx>(
         | ty::Closure(..)
         | ty::Generator(..)
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::FnPtr(_)
         | ty::RawPtr(_)
         | ty::Str
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index cc7b6c91b60..907f014dfb5 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -101,6 +101,7 @@ pub(crate) fn eval_nullary_intrinsic<'tcx>(
             | ty::Closure(_, _)
             | ty::Generator(_, _, _)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(_, _)
             | ty::Never
             | ty::Tuple(_)
             | ty::Error(_) => ConstValue::from_machine_usize(0u64, &tcx),
@@ -447,7 +448,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 }
 
                 if intrinsic_name == sym::assert_zero_valid {
-                    let should_panic = !self.tcx.permits_zero_init(layout);
+                    let should_panic = !self.tcx.permits_zero_init(self.param_env.and(layout));
 
                     if should_panic {
                         M::abort(
@@ -461,7 +462,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 }
 
                 if intrinsic_name == sym::assert_mem_uninitialized_valid {
-                    let should_panic = !self.tcx.permits_uninit_init(layout);
+                    let should_panic = !self.tcx.permits_uninit_init(self.param_env.and(layout));
 
                     if should_panic {
                         M::abort(
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs
index 248953de867..76ed7b80f8d 100644
--- a/compiler/rustc_const_eval/src/interpret/machine.rs
+++ b/compiler/rustc_const_eval/src/interpret/machine.rs
@@ -244,12 +244,18 @@ pub trait Machine<'mir, 'tcx>: Sized {
     }
 
     /// Called before a basic block terminator is executed.
-    /// You can use this to detect endlessly running programs.
     #[inline]
     fn before_terminator(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
         Ok(())
     }
 
+    /// Called when the interpreter encounters a `StatementKind::ConstEvalCounter` instruction.
+    /// You can use this to detect long or endlessly running programs.
+    #[inline]
+    fn increment_const_eval_counter(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
+        Ok(())
+    }
+
     /// Called before a global allocation is accessed.
     /// `def_id` is `Some` if this is the "lazy" allocation of a static.
     #[inline]
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index befc0928f3d..a1b3985dce4 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/compiler/rustc_const_eval/src/interpret/operand.rs
@@ -319,7 +319,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 assert_eq!(size, mplace.layout.size, "abi::Scalar size does not match layout size");
                 let scalar = alloc.read_scalar(
                     alloc_range(Size::ZERO, size),
-                    /*read_provenance*/ s.is_ptr(),
+                    /*read_provenance*/ matches!(s, abi::Pointer(_)),
                 )?;
                 Some(ImmTy { imm: scalar.into(), layout: mplace.layout })
             }
@@ -335,11 +335,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 assert!(b_offset.bytes() > 0); // in `operand_field` we use the offset to tell apart the fields
                 let a_val = alloc.read_scalar(
                     alloc_range(Size::ZERO, a_size),
-                    /*read_provenance*/ a.is_ptr(),
+                    /*read_provenance*/ matches!(a, abi::Pointer(_)),
                 )?;
                 let b_val = alloc.read_scalar(
                     alloc_range(b_offset, b_size),
-                    /*read_provenance*/ b.is_ptr(),
+                    /*read_provenance*/ matches!(b, abi::Pointer(_)),
                 )?;
                 Some(ImmTy { imm: Immediate::ScalarPair(a_val, b_val), layout: mplace.layout })
             }
diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
index fad4cb06cd6..d101937fd74 100644
--- a/compiler/rustc_const_eval/src/interpret/step.rs
+++ b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -129,6 +129,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // FIXME(#73156): Handle source code coverage in const eval
             Coverage(..) => {}
 
+            ConstEvalCounter => {
+                M::increment_const_eval_counter(self)?;
+            }
+
             // Defined to do nothing. These are added by optimization passes, to avoid changing the
             // size of MIR constantly.
             Nop => {}
diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 19e359986a1..aa539516d5e 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -602,6 +602,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
             | ty::Bound(..)
             | ty::Param(..)
             | ty::Alias(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::GeneratorWitness(..) => bug!("Encountered invalid type {:?}", ty),
         }
     }
diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs
index 57b91df2d07..51624a0c6c8 100644
--- a/compiler/rustc_const_eval/src/lib.rs
+++ b/compiler/rustc_const_eval/src/lib.rs
@@ -58,7 +58,12 @@ pub fn provide(providers: &mut Providers) {
         let (param_env, value) = param_env_and_value.into_parts();
         const_eval::deref_mir_constant(tcx, param_env, value)
     };
-    providers.permits_uninit_init =
-        |tcx, ty| util::might_permit_raw_init(tcx, ty, InitKind::UninitMitigated0x01Fill);
-    providers.permits_zero_init = |tcx, ty| util::might_permit_raw_init(tcx, ty, InitKind::Zero);
+    providers.permits_uninit_init = |tcx, param_env_and_ty| {
+        let (param_env, ty) = param_env_and_ty.into_parts();
+        util::might_permit_raw_init(tcx, param_env, ty, InitKind::UninitMitigated0x01Fill)
+    };
+    providers.permits_zero_init = |tcx, param_env_and_ty| {
+        let (param_env, ty) = param_env_and_ty.into_parts();
+        util::might_permit_raw_init(tcx, param_env, ty, InitKind::Zero)
+    };
 }
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
index 79f1737e32b..f47e3e86ebe 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
@@ -693,6 +693,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             | StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
         }
     }
@@ -754,12 +755,9 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                         let ocx = ObligationCtxt::new(&infcx);
 
                         let predicates = tcx.predicates_of(callee).instantiate(tcx, substs);
-                        let hir_id = tcx
-                            .hir()
-                            .local_def_id_to_hir_id(self.body.source.def_id().expect_local());
                         let cause = ObligationCause::new(
                             terminator.source_info.span,
-                            hir_id,
+                            self.body.source.def_id().expect_local(),
                             ObligationCauseCode::ItemObligation(callee),
                         );
                         let normalized_predicates = ocx.normalize(&cause, param_env, predicates);
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/mod.rs b/compiler/rustc_const_eval/src/transform/check_consts/mod.rs
index 54868e418c4..e841500bf3e 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/mod.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/mod.rs
@@ -72,7 +72,7 @@ impl<'mir, 'tcx> ConstCx<'mir, 'tcx> {
             let ty::Closure(_, substs) = ty.kind() else { bug!("type_of closure not ty::Closure") };
             substs.as_closure().sig()
         } else {
-            self.tcx.fn_sig(did)
+            self.tcx.fn_sig(did).subst_identity()
         }
     }
 }
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index dd168a9ac3c..a2f2457487a 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -13,7 +13,7 @@ use rustc_middle::mir::{
     ProjectionElem, RetagKind, RuntimePhase, Rvalue, SourceScope, Statement, StatementKind,
     Terminator, TerminatorKind, UnOp, START_BLOCK,
 };
-use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt};
 use rustc_mir_dataflow::impls::MaybeStorageLive;
 use rustc_mir_dataflow::storage::always_storage_live_locals;
 use rustc_mir_dataflow::{Analysis, ResultsCursor};
@@ -230,11 +230,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             // Equal types, all is good.
             return true;
         }
-        // Normalization reveals opaque types, but we may be validating MIR while computing
-        // said opaque types, causing cycles.
-        if (src, dest).has_opaque_types() {
-            return true;
-        }
 
         crate::util::is_subtype(self.tcx, self.param_env, src, dest)
     }
@@ -377,12 +372,12 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                                 return;
                             };
 
-                            let Some(&f_ty) = layout.field_tys.get(local) else {
+                            let Some(f_ty) = layout.field_tys.get(local) else {
                                 self.fail(location, format!("Out of bounds local {:?} for {:?}", local, parent_ty));
                                 return;
                             };
 
-                            f_ty
+                            f_ty.ty
                         } else {
                             let Some(f_ty) = substs.as_generator().prefix_tys().nth(f.index()) else {
                                 fail_out_of_bounds(self, location);
@@ -766,6 +761,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             StatementKind::StorageLive(..)
             | StatementKind::StorageDead(..)
             | StatementKind::Coverage(_)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
         }
 
diff --git a/compiler/rustc_const_eval/src/util/call_kind.rs b/compiler/rustc_const_eval/src/util/call_kind.rs
index 38d9b044981..995363c0edd 100644
--- a/compiler/rustc_const_eval/src/util/call_kind.rs
+++ b/compiler/rustc_const_eval/src/util/call_kind.rs
@@ -40,6 +40,7 @@ pub enum CallKind<'tcx> {
         self_arg: Option<Ident>,
         desugaring: Option<(CallDesugaringKind, Ty<'tcx>)>,
         method_did: DefId,
+        method_substs: SubstsRef<'tcx>,
     },
     /// A call to `Fn(..)::call(..)`, desugared from `my_closure(a, b, c)`
     FnCall { fn_trait_id: DefId, self_ty: Ty<'tcx> },
@@ -131,6 +132,6 @@ pub fn call_kind<'tcx>(
         } else {
             None
         };
-        CallKind::Normal { self_arg, desugaring, method_did }
+        CallKind::Normal { self_arg, desugaring, method_did, method_substs }
     })
 }
diff --git a/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs b/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs
index 4ce107ea68d..48961b7aac6 100644
--- a/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs
+++ b/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs
@@ -20,13 +20,14 @@ use crate::interpret::{InterpCx, MemoryKind, OpTy};
 /// to the full uninit check).
 pub fn might_permit_raw_init<'tcx>(
     tcx: TyCtxt<'tcx>,
+    param_env: ParamEnv<'tcx>,
     ty: TyAndLayout<'tcx>,
     kind: InitKind,
 ) -> bool {
     if tcx.sess.opts.unstable_opts.strict_init_checks {
         might_permit_raw_init_strict(ty, tcx, kind)
     } else {
-        let layout_cx = LayoutCx { tcx, param_env: ParamEnv::reveal_all() };
+        let layout_cx = LayoutCx { tcx, param_env };
         might_permit_raw_init_lax(ty, &layout_cx, kind)
     }
 }
diff --git a/compiler/rustc_const_eval/src/util/type_name.rs b/compiler/rustc_const_eval/src/util/type_name.rs
index c4122f66498..4e80a285186 100644
--- a/compiler/rustc_const_eval/src/util/type_name.rs
+++ b/compiler/rustc_const_eval/src/util/type_name.rs
@@ -64,6 +64,7 @@ impl<'tcx> Printer<'tcx> for AbsolutePathPrinter<'tcx> {
             ty::Foreign(def_id) => self.print_def_path(def_id, &[]),
 
             ty::GeneratorWitness(_) => bug!("type_name: unexpected `GeneratorWitness`"),
+            ty::GeneratorWitnessMIR(..) => bug!("type_name: unexpected `GeneratorWitnessMIR`"),
         }
     }
 
diff --git a/compiler/rustc_data_structures/src/graph/dominators/mod.rs b/compiler/rustc_data_structures/src/graph/dominators/mod.rs
index 471457f61b2..0a21a4249c8 100644
--- a/compiler/rustc_data_structures/src/graph/dominators/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/dominators/mod.rs
@@ -135,7 +135,47 @@ pub fn dominators<G: ControlFlowGraph>(graph: G) -> Dominators<G::Node> {
         // This loop computes the semi[w] for w.
         semi[w] = w;
         for v in graph.predecessors(pre_order_to_real[w]) {
-            // Reachable vertices may have unreachable predecessors, so ignore any of them
+            // TL;DR: Reachable vertices may have unreachable predecessors, so ignore any of them.
+            //
+            // Ignore blocks which are not connected to the entry block.
+            //
+            // The algorithm that was used to traverse the graph and build the
+            // `pre_order_to_real` and `real_to_pre_order` vectors does so by
+            // starting from the entry block and following the successors.
+            // Therefore, any blocks not reachable from the entry block will be
+            // set to `None` in the `pre_order_to_real` vector.
+            //
+            // For example, in this graph, A and B should be skipped:
+            //
+            //           ┌─────┐
+            //           │     │
+            //           └──┬──┘
+            //              │
+            //           ┌──▼──┐              ┌─────┐
+            //           │     │              │  A  │
+            //           └──┬──┘              └──┬──┘
+            //              │                    │
+            //      ┌───────┴───────┐            │
+            //      │               │            │
+            //   ┌──▼──┐         ┌──▼──┐      ┌──▼──┐
+            //   │     │         │     │      │  B  │
+            //   └──┬──┘         └──┬──┘      └──┬──┘
+            //      │               └──────┬─────┘
+            //   ┌──▼──┐                   │
+            //   │     │                   │
+            //   └──┬──┘                ┌──▼──┐
+            //      │                   │     │
+            //      │                   └─────┘
+            //   ┌──▼──┐
+            //   │     │
+            //   └──┬──┘
+            //      │
+            //   ┌──▼──┐
+            //   │     │
+            //   └─────┘
+            //
+            // ...this may be the case if a MirPass modifies the CFG to remove
+            // or rearrange certain blocks/edges.
             let Some(v) = real_to_pre_order[v] else {
                 continue
             };
@@ -264,13 +304,18 @@ fn compress(
     }
 }
 
+/// Tracks the list of dominators for each node.
 #[derive(Clone, Debug)]
 pub struct Dominators<N: Idx> {
     post_order_rank: IndexVec<N, usize>,
+    // Even though we track only the immediate dominator of each node, it's
+    // possible to get its full list of dominators by looking up the dominator
+    // of each dominator. (See the `impl Iterator for Iter` definition).
     immediate_dominators: IndexVec<N, Option<N>>,
 }
 
 impl<Node: Idx> Dominators<Node> {
+    /// Whether the given Node has an immediate dominator.
     pub fn is_reachable(&self, node: Node) -> bool {
         self.immediate_dominators[node].is_some()
     }
@@ -280,12 +325,14 @@ impl<Node: Idx> Dominators<Node> {
         self.immediate_dominators[node].unwrap()
     }
 
+    /// Provides an iterator over each dominator up the CFG, for the given Node.
+    /// See the `impl Iterator for Iter` definition to understand how this works.
     pub fn dominators(&self, node: Node) -> Iter<'_, Node> {
         assert!(self.is_reachable(node), "node {node:?} is not reachable");
         Iter { dominators: self, node: Some(node) }
     }
 
-    pub fn is_dominated_by(&self, node: Node, dom: Node) -> bool {
+    pub fn dominates(&self, dom: Node, node: Node) -> bool {
         // FIXME -- could be optimized by using post-order-rank
         self.dominators(node).any(|n| n == dom)
     }
diff --git a/compiler/rustc_data_structures/src/obligation_forest/mod.rs b/compiler/rustc_data_structures/src/obligation_forest/mod.rs
index 10e673cd929..dda422c6dd0 100644
--- a/compiler/rustc_data_structures/src/obligation_forest/mod.rs
+++ b/compiler/rustc_data_structures/src/obligation_forest/mod.rs
@@ -139,8 +139,7 @@ pub enum ProcessResult<O, E> {
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 struct ObligationTreeId(usize);
 
-type ObligationTreeIdGenerator =
-    std::iter::Map<std::ops::RangeFrom<usize>, fn(usize) -> ObligationTreeId>;
+type ObligationTreeIdGenerator = impl Iterator<Item = ObligationTreeId>;
 
 pub struct ObligationForest<O: ForestObligation> {
     /// The list of obligations. In between calls to [Self::process_obligations],
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
index f50ad0137b8..ccefd6adaf1 100644
--- a/compiler/rustc_driver/src/lib.rs
+++ b/compiler/rustc_driver/src/lib.rs
@@ -296,9 +296,8 @@ fn run_compiler(
 
             if let Some(ppm) = &sess.opts.pretty {
                 if ppm.needs_ast_map() {
-                    let expanded_crate = queries.expansion()?.borrow().0.clone();
                     queries.global_ctxt()?.enter(|tcx| {
-                        pretty::print_after_hir_lowering(tcx, &*expanded_crate, *ppm);
+                        pretty::print_after_hir_lowering(tcx, *ppm);
                         Ok(())
                     })?;
                 } else {
@@ -328,11 +327,15 @@ fn run_compiler(
                 }
             }
 
-            queries.global_ctxt()?;
+            let mut gctxt = queries.global_ctxt()?;
             if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
                 return early_exit();
             }
 
+            // Make sure the `output_filenames` query is run for its side
+            // effects of writing the dep-info and reporting errors.
+            gctxt.enter(|tcx| tcx.output_filenames(()));
+
             if sess.opts.output_types.contains_key(&OutputType::DepInfo)
                 && sess.opts.output_types.len() == 1
             {
@@ -343,7 +346,7 @@ fn run_compiler(
                 return early_exit();
             }
 
-            queries.global_ctxt()?.enter(|tcx| {
+            gctxt.enter(|tcx| {
                 let result = tcx.analysis(());
                 if sess.opts.unstable_opts.save_analysis {
                     let crate_name = tcx.crate_name(LOCAL_CRATE);
@@ -360,6 +363,8 @@ fn run_compiler(
                 result
             })?;
 
+            drop(gctxt);
+
             if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
                 return early_exit();
             }
diff --git a/compiler/rustc_driver/src/pretty.rs b/compiler/rustc_driver/src/pretty.rs
index ae3ac8625b1..446c6832cb7 100644
--- a/compiler/rustc_driver/src/pretty.rs
+++ b/compiler/rustc_driver/src/pretty.rs
@@ -403,7 +403,7 @@ pub fn print_after_parsing(sess: &Session, krate: &ast::Crate, ppm: PpMode) {
     write_or_print(&out, sess);
 }
 
-pub fn print_after_hir_lowering<'tcx>(tcx: TyCtxt<'tcx>, krate: &ast::Crate, ppm: PpMode) {
+pub fn print_after_hir_lowering<'tcx>(tcx: TyCtxt<'tcx>, ppm: PpMode) {
     if ppm.needs_analysis() {
         abort_on_err(print_with_analysis(tcx, ppm), tcx.sess);
         return;
@@ -420,7 +420,7 @@ pub fn print_after_hir_lowering<'tcx>(tcx: TyCtxt<'tcx>, krate: &ast::Crate, ppm
                 let parse = &sess.parse_sess;
                 pprust::print_crate(
                     sess.source_map(),
-                    krate,
+                    &tcx.resolver_for_lowering(()).borrow().1,
                     src_name,
                     src,
                     annotation.pp_ann(),
@@ -433,7 +433,7 @@ pub fn print_after_hir_lowering<'tcx>(tcx: TyCtxt<'tcx>, krate: &ast::Crate, ppm
 
         AstTree(PpAstTreeMode::Expanded) => {
             debug!("pretty-printing expanded AST");
-            format!("{krate:#?}")
+            format!("{:#?}", tcx.resolver_for_lowering(()).borrow().1)
         }
 
         Hir(s) => call_with_pp_support_hir(&s, tcx, move |annotation, hir_map| {
@@ -498,6 +498,21 @@ fn print_with_analysis(tcx: TyCtxt<'_>, ppm: PpMode) -> Result<(), ErrorGuarante
             out
         }
 
+        ThirFlat => {
+            let mut out = String::new();
+            abort_on_err(rustc_hir_analysis::check_crate(tcx), tcx.sess);
+            debug!("pretty printing THIR flat");
+            for did in tcx.hir().body_owners() {
+                let _ = writeln!(
+                    out,
+                    "{:?}:\n{}\n",
+                    did,
+                    tcx.thir_flat(ty::WithOptConstParam::unknown(did))
+                );
+            }
+            out
+        }
+
         _ => unreachable!(),
     };
 
diff --git a/compiler/rustc_error_codes/src/error_codes.rs b/compiler/rustc_error_codes/src/error_codes.rs
index 9d5f4ad7520..4ae372bb904 100644
--- a/compiler/rustc_error_codes/src/error_codes.rs
+++ b/compiler/rustc_error_codes/src/error_codes.rs
@@ -506,6 +506,7 @@ E0785: include_str!("./error_codes/E0785.md"),
 E0786: include_str!("./error_codes/E0786.md"),
 E0787: include_str!("./error_codes/E0787.md"),
 E0788: include_str!("./error_codes/E0788.md"),
+E0789: include_str!("./error_codes/E0789.md"),
 E0790: include_str!("./error_codes/E0790.md"),
 E0791: include_str!("./error_codes/E0791.md"),
 E0792: include_str!("./error_codes/E0792.md"),
@@ -645,5 +646,4 @@ E0792: include_str!("./error_codes/E0792.md"),
 //  E0721, // `await` keyword
 //  E0723, // unstable feature in `const` context
 //  E0738, // Removed; errored on `#[track_caller] fn`s in `extern "Rust" { ... }`.
-    E0789, // rustc_allowed_through_unstable_modules without stability attribute
 }
diff --git a/compiler/rustc_error_codes/src/error_codes/E0587.md b/compiler/rustc_error_codes/src/error_codes/E0587.md
index ee9031dc379..d7998af85b9 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0587.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0587.md
@@ -11,6 +11,6 @@ You cannot use `packed` and `align` hints on a same type. If you want to pack a
 type to a given size, you should provide a size to packed:
 
 ```
-#[repr(packed)] // ok!
+#[repr(packed(8))] // ok!
 struct Umbrella(i32);
 ```
diff --git a/compiler/rustc_error_codes/src/error_codes/E0789.md b/compiler/rustc_error_codes/src/error_codes/E0789.md
new file mode 100644
index 00000000000..89b7cd422fe
--- /dev/null
+++ b/compiler/rustc_error_codes/src/error_codes/E0789.md
@@ -0,0 +1,30 @@
+#### This error code is internal to the compiler and will not be emitted with normal Rust code.
+
+The internal `rustc_allowed_through_unstable_modules` attribute must be used
+on an item with a `stable` attribute.
+
+Erroneous code example:
+
+```compile_fail,E0789
+// NOTE: both of these attributes are perma-unstable and should *never* be
+//       used outside of the compiler and standard library.
+#![feature(rustc_attrs)]
+#![feature(staged_api)]
+
+#![unstable(feature = "foo_module", reason = "...", issue = "123")]
+
+#[rustc_allowed_through_unstable_modules]
+// #[stable(feature = "foo", since = "1.0")]
+struct Foo;
+// ^^^ error: `rustc_allowed_through_unstable_modules` attribute must be
+//            paired with a `stable` attribute
+```
+
+Typically when an item is marked with a `stable` attribute, the modules that
+enclose the item must also be marked with `stable` attributes, otherwise the
+item becomes *de facto* unstable. `#[rustc_allowed_through_unstable_modules]`
+is a workaround which allows an item to "escape" its unstable parent modules.
+This error occurs when an item is marked with
+`#[rustc_allowed_through_unstable_modules]` but no supplementary `stable`
+attribute exists. See [#99288](https://github.com/rust-lang/rust/pull/99288)
+for an example of `#[rustc_allowed_through_unstable_modules]` in use.
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 9e4332c4283..0021638c102 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -123,4 +123,7 @@ borrowck_cannot_move_when_borrowed =
 
 borrowck_opaque_type_non_generic_param =
     expected generic {$kind} parameter, found `{$ty}`
-    .label = this generic parameter must be used with a generic {$kind} parameter
+    .label = {STREQ($ty, "'static") ->
+        [true] cannot use static lifetime; use a bound lifetime instead or remove the lifetime parameter from the opaque type
+        *[other] this generic parameter must be used with a generic {$kind} parameter
+    }
diff --git a/compiler/rustc_error_messages/locales/en-US/codegen_gcc.ftl b/compiler/rustc_error_messages/locales/en-US/codegen_gcc.ftl
index 08ce5172574..6101b28ab0c 100644
--- a/compiler/rustc_error_messages/locales/en-US/codegen_gcc.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/codegen_gcc.ftl
@@ -23,7 +23,7 @@ codegen_gcc_invalid_monomorphization_unsupported_element =
     invalid monomorphization of `{$name}` intrinsic: unsupported {$name} from `{$in_ty}` with element `{$elem_ty}` to `{$ret_ty}`
 
 codegen_gcc_invalid_monomorphization_invalid_bitmask =
-    invalid monomorphization of `{$name}` intrinsic: invalid bitmask `{ty}`, expected `u{$expected_int_bits}` or `[u8; {$expected_bytes}]`
+    invalid monomorphization of `{$name}` intrinsic: invalid bitmask `{$ty}`, expected `u{$expected_int_bits}` or `[u8; {$expected_bytes}]`
 
 codegen_gcc_invalid_monomorphization_simd_shuffle =
     invalid monomorphization of `{$name}` intrinsic: simd_shuffle index must be an array of `u32`, got `{$ty}`
diff --git a/compiler/rustc_error_messages/locales/en-US/codegen_llvm.ftl b/compiler/rustc_error_messages/locales/en-US/codegen_llvm.ftl
index 860212b051f..b82c903290b 100644
--- a/compiler/rustc_error_messages/locales/en-US/codegen_llvm.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/codegen_llvm.ftl
@@ -11,9 +11,6 @@ codegen_llvm_unknown_ctarget_feature_prefix =
 codegen_llvm_error_creating_import_library =
     Error creating import library for {$lib_name}: {$error}
 
-codegen_llvm_instrument_coverage_requires_llvm_12 =
-    rustc option `-C instrument-coverage` requires LLVM 12 or higher.
-
 codegen_llvm_symbol_already_defined =
     symbol `{$symbol_name}` is already defined
 
diff --git a/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl b/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl
index c8c7afb5f91..4924105128d 100644
--- a/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl
@@ -179,9 +179,9 @@ codegen_ssa_extract_bundled_libs_write_file = failed to write file '{$rlib}': {$
 
 codegen_ssa_unsupported_arch = unsupported arch `{$arch}` for os `{$os}`
 
-codegen_ssa_apple_sdk_error_sdk_path = failed to get {$sdk_name} SDK path: {error}
+codegen_ssa_apple_sdk_error_sdk_path = failed to get {$sdk_name} SDK path: {$error}
 
-codegen_ssa_read_file = failed to read file: {message}
+codegen_ssa_read_file = failed to read file: {$message}
 
 codegen_ssa_unsupported_link_self_contained = option `-C link-self-contained` is not supported on this target
 
diff --git a/compiler/rustc_error_messages/locales/en-US/infer.ftl b/compiler/rustc_error_messages/locales/en-US/infer.ftl
index 164d6d26d23..bcc1d9002df 100644
--- a/compiler/rustc_error_messages/locales/en-US/infer.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/infer.ftl
@@ -147,8 +147,6 @@ infer_region_explanation = {$pref_kind ->
 }{$desc_kind ->
     *[should_not_happen] [{$desc_kind}]
     [restatic] the static lifetime
-    [reempty] the empty lifetime
-    [reemptyuni] the empty lifetime in universe {$desc_arg}
     [revar] lifetime {$desc_arg}
 
     [as_defined] the lifetime `{$desc_arg}` as defined here
diff --git a/compiler/rustc_error_messages/locales/en-US/lint.ftl b/compiler/rustc_error_messages/locales/en-US/lint.ftl
index d63ff77d8e2..dca678dff7a 100644
--- a/compiler/rustc_error_messages/locales/en-US/lint.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/lint.ftl
@@ -100,6 +100,8 @@ lint_cstring_ptr = getting the inner pointer of a temporary `CString`
     .note = pointers do not have a lifetime; when calling `as_ptr` the `CString` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
     .help = for more information, see https://doc.rust-lang.org/reference/destructors.html
 
+lint_multple_supertrait_upcastable = `{$ident}` is object-safe and has multiple supertraits
+
 lint_identifier_non_ascii_char = identifier contains non-ASCII characters
 
 lint_identifier_uncommon_codepoints = identifier contains uncommon Unicode codepoints
diff --git a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
index 224855fff8b..f9bda721df3 100644
--- a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
@@ -299,10 +299,18 @@ mir_build_borrow_of_moved_value = borrow of moved value
     .suggestion = borrow this binding in the pattern to avoid moving the value
 
 mir_build_multiple_mut_borrows = cannot borrow value as mutable more than once at a time
-    .label = first mutable borrow, by `{$name}`, occurs here
-    .mutable_borrow = another mutable borrow, by `{$name_mut}`, occurs here
-    .immutable_borrow = also borrowed as immutable, by `{$name_immut}`, here
-    .moved = also moved into `{$name_moved}` here
+
+mir_build_already_borrowed = cannot borrow value as mutable because it is also borrowed as immutable
+
+mir_build_already_mut_borrowed = cannot borrow value as immutable because it is also borrowed as mutable
+
+mir_build_moved_while_borrowed = cannot move out of value because it is borrowed
+
+mir_build_mutable_borrow = value is mutably borrowed by `{$name}` here
+
+mir_build_borrow = value is borrowed by `{$name}` here
+
+mir_build_moved = value is moved into `{$name}` here
 
 mir_build_union_pattern = cannot use unions in constant patterns
 
diff --git a/compiler/rustc_error_messages/locales/en-US/parse.ftl b/compiler/rustc_error_messages/locales/en-US/parse.ftl
index 8f063f5082c..1728ef70cba 100644
--- a/compiler/rustc_error_messages/locales/en-US/parse.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/parse.ftl
@@ -199,6 +199,17 @@ parse_match_arm_body_without_braces = `match` arm body without braces
         } with a body
     .suggestion_use_comma_not_semicolon = use a comma to end a `match` arm expression
 
+parse_inclusive_range_extra_equals = unexpected `=` after inclusive range
+    .suggestion_remove_eq = use `..=` instead
+    .note = inclusive ranges end with a single equals sign (`..=`)
+
+parse_inclusive_range_match_arrow = unexpected `=>` after open range
+    .suggestion_add_space = add a space between the pattern and `=>`
+
+parse_inclusive_range_no_end = inclusive range with no end
+    .suggestion_open_range = use `..` instead
+    .note = inclusive ranges must be bounded at the end (`..=b` or `a..=b`)
+
 parse_struct_literal_not_allowed_here = struct literals are not allowed here
     .suggestion = surround the struct literal with parentheses
 
@@ -238,6 +249,7 @@ parse_const_let_mutually_exclusive = `const` and `let` are mutually exclusive
 
 parse_invalid_expression_in_let_else = a `{$operator}` expression cannot be directly assigned in `let...else`
 parse_invalid_curly_in_let_else = right curly brace `{"}"}` before `else` in a `let...else` statement not allowed
+parse_extra_if_in_let_else = remove the `if` if you meant to write a `let...else` statement
 
 parse_compound_assignment_expression_in_let = can't reassign to an uninitialized variable
     .suggestion = initialize the variable
diff --git a/compiler/rustc_error_messages/locales/en-US/passes.ftl b/compiler/rustc_error_messages/locales/en-US/passes.ftl
index 91857dd227d..0c2ab3d08f9 100644
--- a/compiler/rustc_error_messages/locales/en-US/passes.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/passes.ftl
@@ -710,3 +710,24 @@ passes_ignored_derived_impls =
       [one] trait {$trait_list}, but this is
      *[other] traits {$trait_list}, but these are
     } intentionally ignored during dead code analysis
+
+passes_proc_macro_typeerror = mismatched {$kind} signature
+    .label = found {$found}, expected type `proc_macro::TokenStream`
+    .note = {$kind}s must have a signature of `{$expected_signature}`
+
+passes_proc_macro_diff_arg_count = mismatched {$kind} signature
+    .label = found unexpected {$count ->
+      [one] argument
+     *[other] arguments
+    }
+    .note = {$kind}s must have a signature of `{$expected_signature}`
+
+passes_proc_macro_missing_args = mismatched {$kind} signature
+    .label = {$kind} must have {$expected_input_count ->
+      [one] one argument
+     *[other] two arguments
+    } of type `proc_macro::TokenStream`
+
+passes_proc_macro_invalid_abi = proc macro functions may not be `extern "{$abi}"`
+
+passes_proc_macro_unsafe = proc macro functions may not be `unsafe`
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index 37a51980a08..f053bdc3809 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -182,6 +182,9 @@ pub fn fluent_bundle(
     trace!(?locale);
     let mut bundle = new_bundle(vec![locale]);
 
+    // Add convenience functions available to ftl authors.
+    register_functions(&mut bundle);
+
     // Fluent diagnostics can insert directionality isolation markers around interpolated variables
     // indicating that there may be a shift from right-to-left to left-to-right text (or
     // vice-versa). These are disabled because they are sometimes visible in the error output, but
@@ -244,6 +247,15 @@ pub fn fluent_bundle(
     Ok(Some(bundle))
 }
 
+fn register_functions(bundle: &mut FluentBundle) {
+    bundle
+        .add_function("STREQ", |positional, _named| match positional {
+            [FluentValue::String(a), FluentValue::String(b)] => format!("{}", (a == b)).into(),
+            _ => FluentValue::Error,
+        })
+        .expect("Failed to add a function to the bundle.");
+}
+
 /// Type alias for the result of `fallback_fluent_bundle` - a reference-counted pointer to a lazily
 /// evaluated fluent bundle.
 pub type LazyFallbackBundle = Lrc<Lazy<FluentBundle, impl FnOnce() -> FluentBundle>>;
@@ -256,6 +268,9 @@ pub fn fallback_fluent_bundle(
 ) -> LazyFallbackBundle {
     Lrc::new(Lazy::new(move || {
         let mut fallback_bundle = new_bundle(vec![langid!("en-US")]);
+
+        register_functions(&mut fallback_bundle);
+
         // See comment in `fluent_bundle`.
         fallback_bundle.set_use_isolating(with_directionality_markers);
 
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 51b2ff6a003..4ad24c1400d 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -629,19 +629,27 @@ impl Diagnostic {
         applicability: Applicability,
         style: SuggestionStyle,
     ) -> &mut Self {
-        assert!(!suggestion.is_empty());
-        debug_assert!(
-            !(suggestion.iter().any(|(sp, text)| sp.is_empty() && text.is_empty())),
-            "Span must not be empty and have no suggestion"
+        let mut parts = suggestion
+            .into_iter()
+            .map(|(span, snippet)| SubstitutionPart { snippet, span })
+            .collect::<Vec<_>>();
+
+        parts.sort_unstable_by_key(|part| part.span);
+
+        assert!(!parts.is_empty());
+        debug_assert_eq!(
+            parts.iter().find(|part| part.span.is_empty() && part.snippet.is_empty()),
+            None,
+            "Span must not be empty and have no suggestion",
+        );
+        debug_assert_eq!(
+            parts.array_windows().find(|[a, b]| a.span.overlaps(b.span)),
+            None,
+            "suggestion must not have overlapping parts",
         );
 
         self.push_suggestion(CodeSuggestion {
-            substitutions: vec![Substitution {
-                parts: suggestion
-                    .into_iter()
-                    .map(|(span, snippet)| SubstitutionPart { snippet, span })
-                    .collect(),
-            }],
+            substitutions: vec![Substitution { parts }],
             msg: self.subdiagnostic_message_to_diagnostic_message(msg),
             style,
             applicability,
@@ -802,25 +810,34 @@ impl Diagnostic {
         suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self {
-        let suggestions: Vec<_> = suggestions.into_iter().collect();
-        debug_assert!(
-            !(suggestions
-                .iter()
-                .flatten()
-                .any(|(sp, suggestion)| sp.is_empty() && suggestion.is_empty())),
-            "Span must not be empty and have no suggestion"
-        );
+        let substitutions = suggestions
+            .into_iter()
+            .map(|sugg| {
+                let mut parts = sugg
+                    .into_iter()
+                    .map(|(span, snippet)| SubstitutionPart { snippet, span })
+                    .collect::<Vec<_>>();
+
+                parts.sort_unstable_by_key(|part| part.span);
+
+                assert!(!parts.is_empty());
+                debug_assert_eq!(
+                    parts.iter().find(|part| part.span.is_empty() && part.snippet.is_empty()),
+                    None,
+                    "Span must not be empty and have no suggestion",
+                );
+                debug_assert_eq!(
+                    parts.array_windows().find(|[a, b]| a.span.overlaps(b.span)),
+                    None,
+                    "suggestion must not have overlapping parts",
+                );
+
+                Substitution { parts }
+            })
+            .collect();
 
         self.push_suggestion(CodeSuggestion {
-            substitutions: suggestions
-                .into_iter()
-                .map(|sugg| Substitution {
-                    parts: sugg
-                        .into_iter()
-                        .map(|(span, snippet)| SubstitutionPart { snippet, span })
-                        .collect(),
-                })
-                .collect(),
+            substitutions,
             msg: self.subdiagnostic_message_to_diagnostic_message(msg),
             style: SuggestionStyle::ShowCode,
             applicability,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 535812fb0e2..d076fc08b0e 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -3,6 +3,7 @@
 //! This module contains the code for creating and emitting diagnostics.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(array_windows)]
 #![feature(drain_filter)]
 #![feature(if_let_guard)]
 #![feature(is_terminal)]
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index 4ebd75f0185..cd431f57019 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -10,7 +10,7 @@ use crate::mbe::transcribe::transcribe;
 
 use rustc_ast as ast;
 use rustc_ast::token::{self, Delimiter, NonterminalKind, Token, TokenKind, TokenKind::*};
-use rustc_ast::tokenstream::{DelimSpan, TokenStream};
+use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree};
 use rustc_ast::{NodeId, DUMMY_NODE_ID};
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, TransparencyError};
@@ -212,7 +212,6 @@ fn expand_macro<'cx>(
             };
             let arm_span = rhses[i].span();
 
-            let rhs_spans = rhs.tts.iter().map(|t| t.span()).collect::<Vec<_>>();
             // rhs has holes ( `$id` and `$(...)` that need filled)
             let mut tts = match transcribe(cx, &named_matches, &rhs, rhs_span, transparency) {
                 Ok(tts) => tts,
@@ -224,12 +223,25 @@ fn expand_macro<'cx>(
 
             // Replace all the tokens for the corresponding positions in the macro, to maintain
             // proper positions in error reporting, while maintaining the macro_backtrace.
-            if rhs_spans.len() == tts.len() {
+            if tts.len() == rhs.tts.len() {
                 tts = tts.map_enumerated(|i, tt| {
                     let mut tt = tt.clone();
-                    let mut sp = rhs_spans[i];
-                    sp = sp.with_ctxt(tt.span().ctxt());
-                    tt.set_span(sp);
+                    let rhs_tt = &rhs.tts[i];
+                    let ctxt = tt.span().ctxt();
+                    match (&mut tt, rhs_tt) {
+                        // preserve the delim spans if able
+                        (
+                            TokenTree::Delimited(target_sp, ..),
+                            mbe::TokenTree::Delimited(source_sp, ..),
+                        ) => {
+                            target_sp.open = source_sp.open.with_ctxt(ctxt);
+                            target_sp.close = source_sp.close.with_ctxt(ctxt);
+                        }
+                        _ => {
+                            let sp = rhs_tt.span().with_ctxt(ctxt);
+                            tt.set_span(sp);
+                        }
+                    }
                     tt
                 });
             }
diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index 196c31302a0..af9c40a3ba5 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -160,6 +160,8 @@ declare_features! (
     (active, intrinsics, "1.0.0", None, None),
     /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
     (active, lang_items, "1.0.0", None, None),
+    /// Allows the `multiple_supertrait_upcastable` lint.
+    (active, multiple_supertrait_upcastable, "CURRENT_RUSTC_VERSION", None, None),
     /// Allows using `#[omit_gdb_pretty_printer_section]`.
     (active, omit_gdb_pretty_printer_section, "1.5.0", None, None),
     /// Allows using `#[prelude_import]` on glob `use` items.
diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs
index 8e2a13a6c0a..93d16716346 100644
--- a/compiler/rustc_feature/src/lib.rs
+++ b/compiler/rustc_feature/src/lib.rs
@@ -83,7 +83,8 @@ impl UnstableFeatures {
     /// Otherwise, only `RUSTC_BOOTSTRAP=1` will work.
     pub fn from_environment(krate: Option<&str>) -> Self {
         // `true` if this is a feature-staged build, i.e., on the beta or stable channel.
-        let disable_unstable_features = option_env!("CFG_DISABLE_UNSTABLE_FEATURES").is_some();
+        let disable_unstable_features =
+            option_env!("CFG_DISABLE_UNSTABLE_FEATURES").map(|s| s != "0").unwrap_or(false);
         // Returns whether `krate` should be counted as unstable
         let is_unstable_crate = |var: &str| {
             krate.map_or(false, |name| var.split(',').any(|new_krate| new_krate == name))
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index d6566860f81..a063307af0c 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -831,8 +831,6 @@ pub struct OwnerNodes<'tcx> {
     pub nodes: IndexVec<ItemLocalId, Option<ParentedNode<'tcx>>>,
     /// Content of local bodies.
     pub bodies: SortedMap<ItemLocalId, &'tcx Body<'tcx>>,
-    /// Non-owning definitions contained in this owner.
-    pub local_id_to_def_id: SortedMap<ItemLocalId, LocalDefId>,
 }
 
 impl<'tcx> OwnerNodes<'tcx> {
@@ -862,7 +860,6 @@ impl fmt::Debug for OwnerNodes<'_> {
                     .collect::<Vec<_>>(),
             )
             .field("bodies", &self.bodies)
-            .field("local_id_to_def_id", &self.local_id_to_def_id)
             .field("hash_without_bodies", &self.hash_without_bodies)
             .field("hash_including_bodies", &self.hash_including_bodies)
             .finish()
@@ -2106,8 +2103,8 @@ pub enum LocalSource {
 }
 
 /// Hints at the original code for a `match _ { .. }`.
-#[derive(Copy, Clone, PartialEq, Eq, Encodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(HashStable_Generic, Encodable, Decodable)]
 pub enum MatchSource {
     /// A `match _ { .. }`.
     Normal,
@@ -2117,6 +2114,8 @@ pub enum MatchSource {
     TryDesugar,
     /// A desugared `<expr>.await`.
     AwaitDesugar,
+    /// A desugared `format_args!()`.
+    FormatArgs,
 }
 
 impl MatchSource {
@@ -2128,6 +2127,7 @@ impl MatchSource {
             ForLoopDesugar => "for",
             TryDesugar => "?",
             AwaitDesugar => ".await",
+            FormatArgs => "format_args!()",
         }
     }
 }
@@ -2263,7 +2263,7 @@ pub struct TraitItem<'hir> {
     pub defaultness: Defaultness,
 }
 
-impl TraitItem<'_> {
+impl<'hir> TraitItem<'hir> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
@@ -2273,6 +2273,32 @@ impl TraitItem<'_> {
     pub fn trait_item_id(&self) -> TraitItemId {
         TraitItemId { owner_id: self.owner_id }
     }
+
+    /// Expect an [`TraitItemKind::Const`] or panic.
+    #[track_caller]
+    pub fn expect_const(&self) -> (&'hir Ty<'hir>, Option<BodyId>) {
+        let TraitItemKind::Const(ty, body) = self.kind else { self.expect_failed("a constant") };
+        (ty, body)
+    }
+
+    /// Expect an [`TraitItemKind::Fn`] or panic.
+    #[track_caller]
+    pub fn expect_fn(&self) -> (&FnSig<'hir>, &TraitFn<'hir>) {
+        let TraitItemKind::Fn(ty, trfn) = &self.kind else { self.expect_failed("a function") };
+        (ty, trfn)
+    }
+
+    /// Expect an [`TraitItemKind::Type`] or panic.
+    #[track_caller]
+    pub fn expect_type(&self) -> (GenericBounds<'hir>, Option<&'hir Ty<'hir>>) {
+        let TraitItemKind::Type(bounds, ty) = self.kind else { self.expect_failed("a type") };
+        (bounds, ty)
+    }
+
+    #[track_caller]
+    fn expect_failed(&self, expected: &'static str) -> ! {
+        panic!("expected {expected} item, found {self:?}")
+    }
 }
 
 /// Represents a trait method's body (or just argument names).
@@ -2325,7 +2351,7 @@ pub struct ImplItem<'hir> {
     pub vis_span: Span,
 }
 
-impl ImplItem<'_> {
+impl<'hir> ImplItem<'hir> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
@@ -2335,6 +2361,32 @@ impl ImplItem<'_> {
     pub fn impl_item_id(&self) -> ImplItemId {
         ImplItemId { owner_id: self.owner_id }
     }
+
+    /// Expect an [`ImplItemKind::Const`] or panic.
+    #[track_caller]
+    pub fn expect_const(&self) -> (&'hir Ty<'hir>, BodyId) {
+        let ImplItemKind::Const(ty, body) = self.kind else { self.expect_failed("a constant") };
+        (ty, body)
+    }
+
+    /// Expect an [`ImplItemKind::Fn`] or panic.
+    #[track_caller]
+    pub fn expect_fn(&self) -> (&FnSig<'hir>, BodyId) {
+        let ImplItemKind::Fn(ty, body) = &self.kind else { self.expect_failed("a function") };
+        (ty, *body)
+    }
+
+    /// Expect an [`ImplItemKind::Type`] or panic.
+    #[track_caller]
+    pub fn expect_type(&self) -> &'hir Ty<'hir> {
+        let ImplItemKind::Type(ty) = self.kind else { self.expect_failed("a type") };
+        ty
+    }
+
+    #[track_caller]
+    fn expect_failed(&self, expected: &'static str) -> ! {
+        panic!("expected {expected} item, found {self:?}")
+    }
 }
 
 /// Represents various kinds of content within an `impl`.
@@ -2995,7 +3047,7 @@ pub struct Item<'hir> {
     pub vis_span: Span,
 }
 
-impl Item<'_> {
+impl<'hir> Item<'hir> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
@@ -3005,6 +3057,132 @@ impl Item<'_> {
     pub fn item_id(&self) -> ItemId {
         ItemId { owner_id: self.owner_id }
     }
+
+    /// Expect an [`ItemKind::ExternCrate`] or panic.
+    #[track_caller]
+    pub fn expect_extern_crate(&self) -> Option<Symbol> {
+        let ItemKind::ExternCrate(s) = self.kind else { self.expect_failed("an extern crate") };
+        s
+    }
+
+    /// Expect an [`ItemKind::Use`] or panic.
+    #[track_caller]
+    pub fn expect_use(&self) -> (&'hir UsePath<'hir>, UseKind) {
+        let ItemKind::Use(p, uk) = self.kind else { self.expect_failed("a use") };
+        (p, uk)
+    }
+
+    /// Expect an [`ItemKind::Static`] or panic.
+    #[track_caller]
+    pub fn expect_static(&self) -> (&'hir Ty<'hir>, Mutability, BodyId) {
+        let ItemKind::Static(ty, mutbl, body) = self.kind else { self.expect_failed("a static") };
+        (ty, mutbl, body)
+    }
+    /// Expect an [`ItemKind::Const`] or panic.
+    #[track_caller]
+    pub fn expect_const(&self) -> (&'hir Ty<'hir>, BodyId) {
+        let ItemKind::Const(ty, body) = self.kind else { self.expect_failed("a constant") };
+        (ty, body)
+    }
+    /// Expect an [`ItemKind::Fn`] or panic.
+    #[track_caller]
+    pub fn expect_fn(&self) -> (&FnSig<'hir>, &'hir Generics<'hir>, BodyId) {
+        let ItemKind::Fn(sig, gen, body) = &self.kind else { self.expect_failed("a function") };
+        (sig, gen, *body)
+    }
+
+    /// Expect an [`ItemKind::Macro`] or panic.
+    #[track_caller]
+    pub fn expect_macro(&self) -> (&ast::MacroDef, MacroKind) {
+        let ItemKind::Macro(def, mk) = &self.kind else { self.expect_failed("a macro") };
+        (def, *mk)
+    }
+
+    /// Expect an [`ItemKind::Mod`] or panic.
+    #[track_caller]
+    pub fn expect_mod(&self) -> &'hir Mod<'hir> {
+        let ItemKind::Mod(m) = self.kind else { self.expect_failed("a module") };
+        m
+    }
+
+    /// Expect an [`ItemKind::ForeignMod`] or panic.
+    #[track_caller]
+    pub fn expect_foreign_mod(&self) -> (Abi, &'hir [ForeignItemRef]) {
+        let ItemKind::ForeignMod { abi, items } = self.kind else { self.expect_failed("a foreign module") };
+        (abi, items)
+    }
+
+    /// Expect an [`ItemKind::GlobalAsm`] or panic.
+    #[track_caller]
+    pub fn expect_global_asm(&self) -> &'hir InlineAsm<'hir> {
+        let ItemKind::GlobalAsm(asm) = self.kind else { self.expect_failed("a global asm") };
+        asm
+    }
+
+    /// Expect an [`ItemKind::TyAlias`] or panic.
+    #[track_caller]
+    pub fn expect_ty_alias(&self) -> (&'hir Ty<'hir>, &'hir Generics<'hir>) {
+        let ItemKind::TyAlias(ty, gen) = self.kind else { self.expect_failed("a type alias") };
+        (ty, gen)
+    }
+
+    /// An opaque `impl Trait` type alias, e.g., `type Foo = impl Bar;`.
+    /// Expect an [`ItemKind::OpaqueTy`] or panic.
+    #[track_caller]
+    pub fn expect_opaque_ty(&self) -> &OpaqueTy<'hir> {
+        let ItemKind::OpaqueTy(ty) = &self.kind else { self.expect_failed("an opaque type") };
+        ty
+    }
+
+    /// Expect an [`ItemKind::Enum`] or panic.
+    #[track_caller]
+    pub fn expect_enum(&self) -> (&EnumDef<'hir>, &'hir Generics<'hir>) {
+        let ItemKind::Enum(def, gen) = &self.kind else { self.expect_failed("an enum") };
+        (def, gen)
+    }
+
+    /// Expect an [`ItemKind::Struct`] or panic.
+    #[track_caller]
+    pub fn expect_struct(&self) -> (&VariantData<'hir>, &'hir Generics<'hir>) {
+        let ItemKind::Struct(data, gen) = &self.kind else { self.expect_failed("a struct") };
+        (data, gen)
+    }
+
+    /// A union definition, e.g., `union Foo<A, B> {x: A, y: B}`.
+    /// Expect an [`ItemKind::Union`] or panic.
+    #[track_caller]
+    pub fn expect_union(&self) -> (&VariantData<'hir>, &'hir Generics<'hir>) {
+        let ItemKind::Union(data, gen) = &self.kind else { self.expect_failed("a union") };
+        (data, gen)
+    }
+
+    /// Expect an [`ItemKind::Trait`] or panic.
+    #[track_caller]
+    pub fn expect_trait(
+        self,
+    ) -> (IsAuto, Unsafety, &'hir Generics<'hir>, GenericBounds<'hir>, &'hir [TraitItemRef]) {
+        let ItemKind::Trait(is_auto, unsafety, gen, bounds, items) = self.kind else { self.expect_failed("a trait") };
+        (is_auto, unsafety, gen, bounds, items)
+    }
+
+    /// Expect an [`ItemKind::TraitAlias`] or panic.
+    #[track_caller]
+    pub fn expect_trait_alias(&self) -> (&'hir Generics<'hir>, GenericBounds<'hir>) {
+        let ItemKind::TraitAlias(gen, bounds) = self.kind else { self.expect_failed("a trait alias") };
+        (gen, bounds)
+    }
+
+    /// Expect an [`ItemKind::Impl`] or panic.
+    #[track_caller]
+    pub fn expect_impl(&self) -> &'hir Impl<'hir> {
+        let ItemKind::Impl(imp) = self.kind else { self.expect_failed("an impl") };
+        imp
+    }
+
+    #[track_caller]
+    fn expect_failed(&self, expected: &'static str) -> ! {
+        panic!("expected {expected} item, found {self:?}")
+    }
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
@@ -3524,6 +3702,13 @@ impl<'hir> Node<'hir> {
         }
     }
 
+    pub fn alias_ty(self) -> Option<&'hir Ty<'hir>> {
+        match self {
+            Node::Item(Item { kind: ItemKind::TyAlias(ty, ..), .. }) => Some(ty),
+            _ => None,
+        }
+    }
+
     pub fn body_id(&self) -> Option<BodyId> {
         match self {
             Node::TraitItem(TraitItem {
@@ -3590,6 +3775,185 @@ impl<'hir> Node<'hir> {
     pub fn tuple_fields(&self) -> Option<&'hir [FieldDef<'hir>]> {
         if let Node::Ctor(&VariantData::Tuple(fields, _, _)) = self { Some(fields) } else { None }
     }
+
+    /// Expect a [`Node::Param`] or panic.
+    #[track_caller]
+    pub fn expect_param(self) -> &'hir Param<'hir> {
+        let Node::Param(this) = self else { self.expect_failed("a parameter") };
+        this
+    }
+
+    /// Expect a [`Node::Item`] or panic.
+    #[track_caller]
+    pub fn expect_item(self) -> &'hir Item<'hir> {
+        let Node::Item(this) = self else { self.expect_failed("a item") };
+        this
+    }
+
+    /// Expect a [`Node::ForeignItem`] or panic.
+    #[track_caller]
+    pub fn expect_foreign_item(self) -> &'hir ForeignItem<'hir> {
+        let Node::ForeignItem(this) = self else { self.expect_failed("a foreign item") };
+        this
+    }
+
+    /// Expect a [`Node::TraitItem`] or panic.
+    #[track_caller]
+    pub fn expect_trait_item(self) -> &'hir TraitItem<'hir> {
+        let Node::TraitItem(this) = self else { self.expect_failed("a trait item") };
+        this
+    }
+
+    /// Expect a [`Node::ImplItem`] or panic.
+    #[track_caller]
+    pub fn expect_impl_item(self) -> &'hir ImplItem<'hir> {
+        let Node::ImplItem(this) = self else { self.expect_failed("an implementation item") };
+        this
+    }
+
+    /// Expect a [`Node::Variant`] or panic.
+    #[track_caller]
+    pub fn expect_variant(self) -> &'hir Variant<'hir> {
+        let Node::Variant(this) = self else { self.expect_failed("a variant") };
+        this
+    }
+
+    /// Expect a [`Node::Field`] or panic.
+    #[track_caller]
+    pub fn expect_field(self) -> &'hir FieldDef<'hir> {
+        let Node::Field(this) = self else { self.expect_failed("a field definition") };
+        this
+    }
+
+    /// Expect a [`Node::AnonConst`] or panic.
+    #[track_caller]
+    pub fn expect_anon_const(self) -> &'hir AnonConst {
+        let Node::AnonConst(this) = self else { self.expect_failed("an anonymous constant") };
+        this
+    }
+
+    /// Expect a [`Node::Expr`] or panic.
+    #[track_caller]
+    pub fn expect_expr(self) -> &'hir Expr<'hir> {
+        let Node::Expr(this) = self else { self.expect_failed("an expression") };
+        this
+    }
+    /// Expect a [`Node::ExprField`] or panic.
+    #[track_caller]
+    pub fn expect_expr_field(self) -> &'hir ExprField<'hir> {
+        let Node::ExprField(this) = self else { self.expect_failed("an expression field") };
+        this
+    }
+
+    /// Expect a [`Node::Stmt`] or panic.
+    #[track_caller]
+    pub fn expect_stmt(self) -> &'hir Stmt<'hir> {
+        let Node::Stmt(this) = self else { self.expect_failed("a statement") };
+        this
+    }
+
+    /// Expect a [`Node::PathSegment`] or panic.
+    #[track_caller]
+    pub fn expect_path_segment(self) -> &'hir PathSegment<'hir> {
+        let Node::PathSegment(this) = self else { self.expect_failed("a path segment") };
+        this
+    }
+
+    /// Expect a [`Node::Ty`] or panic.
+    #[track_caller]
+    pub fn expect_ty(self) -> &'hir Ty<'hir> {
+        let Node::Ty(this) = self else { self.expect_failed("a type") };
+        this
+    }
+
+    /// Expect a [`Node::TypeBinding`] or panic.
+    #[track_caller]
+    pub fn expect_type_binding(self) -> &'hir TypeBinding<'hir> {
+        let Node::TypeBinding(this) = self else { self.expect_failed("a type binding") };
+        this
+    }
+
+    /// Expect a [`Node::TraitRef`] or panic.
+    #[track_caller]
+    pub fn expect_trait_ref(self) -> &'hir TraitRef<'hir> {
+        let Node::TraitRef(this) = self else { self.expect_failed("a trait reference") };
+        this
+    }
+
+    /// Expect a [`Node::Pat`] or panic.
+    #[track_caller]
+    pub fn expect_pat(self) -> &'hir Pat<'hir> {
+        let Node::Pat(this) = self else { self.expect_failed("a pattern") };
+        this
+    }
+
+    /// Expect a [`Node::PatField`] or panic.
+    #[track_caller]
+    pub fn expect_pat_field(self) -> &'hir PatField<'hir> {
+        let Node::PatField(this) = self else { self.expect_failed("a pattern field") };
+        this
+    }
+
+    /// Expect a [`Node::Arm`] or panic.
+    #[track_caller]
+    pub fn expect_arm(self) -> &'hir Arm<'hir> {
+        let Node::Arm(this) = self else { self.expect_failed("an arm") };
+        this
+    }
+
+    /// Expect a [`Node::Block`] or panic.
+    #[track_caller]
+    pub fn expect_block(self) -> &'hir Block<'hir> {
+        let Node::Block(this) = self else { self.expect_failed("a block") };
+        this
+    }
+
+    /// Expect a [`Node::Local`] or panic.
+    #[track_caller]
+    pub fn expect_local(self) -> &'hir Local<'hir> {
+        let Node::Local(this) = self else { self.expect_failed("a local") };
+        this
+    }
+
+    /// Expect a [`Node::Ctor`] or panic.
+    #[track_caller]
+    pub fn expect_ctor(self) -> &'hir VariantData<'hir> {
+        let Node::Ctor(this) = self else { self.expect_failed("a constructor") };
+        this
+    }
+
+    /// Expect a [`Node::Lifetime`] or panic.
+    #[track_caller]
+    pub fn expect_lifetime(self) -> &'hir Lifetime {
+        let Node::Lifetime(this) = self else { self.expect_failed("a lifetime") };
+        this
+    }
+
+    /// Expect a [`Node::GenericParam`] or panic.
+    #[track_caller]
+    pub fn expect_generic_param(self) -> &'hir GenericParam<'hir> {
+        let Node::GenericParam(this) = self else { self.expect_failed("a generic parameter") };
+        this
+    }
+
+    /// Expect a [`Node::Crate`] or panic.
+    #[track_caller]
+    pub fn expect_crate(self) -> &'hir Mod<'hir> {
+        let Node::Crate(this) = self else { self.expect_failed("a crate") };
+        this
+    }
+
+    /// Expect a [`Node::Infer`] or panic.
+    #[track_caller]
+    pub fn expect_infer(self) -> &'hir InferArg {
+        let Node::Infer(this) = self else { self.expect_failed("an infer") };
+        this
+    }
+
+    #[track_caller]
+    fn expect_failed(&self, expected: &'static str) -> ! {
+        panic!("expected {expected} node, found {self:?}")
+    }
 }
 
 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index 02641b7cf8f..f632babab0b 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -67,6 +67,7 @@
 use crate::hir::*;
 use rustc_ast::walk_list;
 use rustc_ast::{Attribute, Label};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::Span;
 
@@ -364,7 +365,7 @@ pub trait Visitor<'v>: Sized {
     fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
         walk_fn_decl(self, fd)
     }
-    fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, _: Span, id: HirId) {
+    fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, _: Span, id: LocalDefId) {
         walk_fn(self, fk, fd, b, id)
     }
     fn visit_use(&mut self, path: &'v UsePath<'v>, hir_id: HirId) {
@@ -468,13 +469,16 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
             visitor.visit_ty(typ);
             visitor.visit_nested_body(body);
         }
-        ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
-            FnKind::ItemFn(item.ident, generics, sig.header),
-            sig.decl,
-            body_id,
-            item.span,
-            item.hir_id(),
-        ),
+        ItemKind::Fn(ref sig, ref generics, body_id) => {
+            visitor.visit_id(item.hir_id());
+            visitor.visit_fn(
+                FnKind::ItemFn(item.ident, generics, sig.header),
+                sig.decl,
+                body_id,
+                item.span,
+                item.owner_id.def_id,
+            )
+        }
         ItemKind::Macro(..) => {
             visitor.visit_id(item.hir_id());
         }
@@ -733,7 +737,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
             walk_list!(visitor, visit_arm, arms);
         }
         ExprKind::Closure(&Closure {
-            def_id: _,
+            def_id,
             binder: _,
             bound_generic_params,
             fn_decl,
@@ -745,7 +749,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
             constness: _,
         }) => {
             walk_list!(visitor, visit_generic_param, bound_generic_params);
-            visitor.visit_fn(FnKind::Closure, fn_decl, body, expression.span, expression.hir_id)
+            visitor.visit_fn(FnKind::Closure, fn_decl, body, expression.span, def_id)
         }
         ExprKind::Block(ref block, ref opt_label) => {
             walk_list!(visitor, visit_label, opt_label);
@@ -923,9 +927,8 @@ pub fn walk_fn<'v, V: Visitor<'v>>(
     function_kind: FnKind<'v>,
     function_declaration: &'v FnDecl<'v>,
     body_id: BodyId,
-    id: HirId,
+    _: LocalDefId,
 ) {
-    visitor.visit_id(id);
     visitor.visit_fn_decl(function_declaration);
     walk_fn_kind(visitor, function_kind);
     visitor.visit_nested_body(body_id)
@@ -953,26 +956,30 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v Trai
     let TraitItem { ident, generics, ref defaultness, ref kind, span, owner_id: _ } = *trait_item;
     let hir_id = trait_item.hir_id();
     visitor.visit_ident(ident);
-    visitor.visit_generics(generics);
-    visitor.visit_defaultness(defaultness);
+    visitor.visit_generics(&generics);
+    visitor.visit_defaultness(&defaultness);
+    visitor.visit_id(hir_id);
     match *kind {
         TraitItemKind::Const(ref ty, default) => {
-            visitor.visit_id(hir_id);
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_nested_body, default);
         }
         TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
-            visitor.visit_id(hir_id);
             visitor.visit_fn_decl(sig.decl);
             for &param_name in param_names {
                 visitor.visit_ident(param_name);
             }
         }
         TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
-            visitor.visit_fn(FnKind::Method(ident, sig), sig.decl, body_id, span, hir_id);
+            visitor.visit_fn(
+                FnKind::Method(ident, sig),
+                sig.decl,
+                body_id,
+                span,
+                trait_item.owner_id.def_id,
+            );
         }
         TraitItemKind::Type(bounds, ref default) => {
-            visitor.visit_id(hir_id);
             walk_list!(visitor, visit_param_bound, bounds);
             walk_list!(visitor, visit_ty, default);
         }
@@ -1002,9 +1009,9 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
     visitor.visit_ident(ident);
     visitor.visit_generics(generics);
     visitor.visit_defaultness(defaultness);
+    visitor.visit_id(impl_item.hir_id());
     match *kind {
         ImplItemKind::Const(ref ty, body) => {
-            visitor.visit_id(impl_item.hir_id());
             visitor.visit_ty(ty);
             visitor.visit_nested_body(body);
         }
@@ -1014,11 +1021,10 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
                 sig.decl,
                 body_id,
                 impl_item.span,
-                impl_item.hir_id(),
+                impl_item.owner_id.def_id,
             );
         }
         ImplItemKind::Type(ref ty) => {
-            visitor.visit_id(impl_item.hir_id());
             visitor.visit_ty(ty);
         }
     }
diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs
index 54fa5702fbc..9158fc08247 100644
--- a/compiler/rustc_hir/src/lang_items.rs
+++ b/compiler/rustc_hir/src/lang_items.rs
@@ -244,6 +244,14 @@ language_item_table! {
     /// libstd panic entry point. Necessary for const eval to be able to catch it
     BeginPanic,              sym::begin_panic,         begin_panic_fn,             Target::Fn,             GenericRequirement::None;
 
+    // Lang items needed for `format_args!()`.
+    FormatAlignment,         sym::format_alignment,    format_alignment,           Target::Enum,           GenericRequirement::None;
+    FormatArgument,          sym::format_argument,     format_argument,            Target::Struct,         GenericRequirement::None;
+    FormatArguments,         sym::format_arguments,    format_arguments,           Target::Struct,         GenericRequirement::None;
+    FormatCount,             sym::format_count,        format_count,               Target::Enum,           GenericRequirement::None;
+    FormatPlaceholder,       sym::format_placeholder,  format_placeholder,         Target::Struct,         GenericRequirement::None;
+    FormatUnsafeArg,         sym::format_unsafe_arg,   format_unsafe_arg,          Target::Struct,         GenericRequirement::None;
+
     ExchangeMalloc,          sym::exchange_malloc,     exchange_malloc_fn,         Target::Fn,             GenericRequirement::None;
     BoxFree,                 sym::box_free,            box_free_fn,                Target::Fn,             GenericRequirement::Minimum(1);
     DropInPlace,             sym::drop_in_place,       drop_in_place_fn,           Target::Fn,             GenericRequirement::Minimum(1);
diff --git a/compiler/rustc_hir/src/stable_hash_impls.rs b/compiler/rustc_hir/src/stable_hash_impls.rs
index 23423e8f3b3..85d0e02d0b6 100644
--- a/compiler/rustc_hir/src/stable_hash_impls.rs
+++ b/compiler/rustc_hir/src/stable_hash_impls.rs
@@ -100,13 +100,8 @@ impl<'tcx, HirCtx: crate::HashStableContext> HashStable<HirCtx> for OwnerNodes<'
         // `local_id_to_def_id` is also ignored because is dependent on the body, then just hashing
         // the body satisfies the condition of two nodes being different have different
         // `hash_stable` results.
-        let OwnerNodes {
-            hash_including_bodies,
-            hash_without_bodies: _,
-            nodes: _,
-            bodies: _,
-            local_id_to_def_id: _,
-        } = *self;
+        let OwnerNodes { hash_including_bodies, hash_without_bodies: _, nodes: _, bodies: _ } =
+            *self;
         hash_including_bodies.hash_stable(hcx, hasher);
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 6435b05cef8..bec9f0ff077 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -27,7 +27,7 @@ use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{walk_generics, Visitor as _};
 use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
-use rustc_infer::infer::TyCtxtInferExt;
+use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
 use rustc_middle::ty::GenericParamDefKind;
@@ -37,7 +37,7 @@ use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECT
 use rustc_span::edition::Edition;
 use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, Ident, Symbol};
-use rustc_span::{sym, Span};
+use rustc_span::{sym, Span, DUMMY_SP};
 use rustc_target::spec::abi;
 use rustc_trait_selection::traits;
 use rustc_trait_selection::traits::astconv_object_safety_violations;
@@ -54,7 +54,7 @@ use std::slice;
 pub struct PathSeg(pub DefId, pub usize);
 
 pub trait AstConv<'tcx> {
-    fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
+    fn tcx(&self) -> TyCtxt<'tcx>;
 
     fn item_def_id(&self) -> DefId;
 
@@ -131,6 +131,8 @@ pub trait AstConv<'tcx> {
     {
         self
     }
+
+    fn infcx(&self) -> Option<&InferCtxt<'tcx>>;
 }
 
 #[derive(Debug)]
@@ -2132,48 +2134,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     )
                     .emit() // Already reported in an earlier stage.
                 } else {
-                    // Find all the `impl`s that `qself_ty` has for any trait that has the
-                    // associated type, so that we suggest the right one.
-                    let infcx = tcx.infer_ctxt().build();
-                    // We create a fresh `ty::ParamEnv` instead of the one for `self.item_def_id()`
-                    // to avoid a cycle error in `src/test/ui/resolve/issue-102946.rs`.
-                    let param_env = ty::ParamEnv::empty();
-                    let traits: Vec<_> = self
-                        .tcx()
-                        .all_traits()
-                        .filter(|trait_def_id| {
-                            // Consider only traits with the associated type
-                            tcx.associated_items(*trait_def_id)
-                                .in_definition_order()
-                                .any(|i| {
-                                    i.kind.namespace() == Namespace::TypeNS
-                                        && i.ident(tcx).normalize_to_macros_2_0() == assoc_ident
-                                        && matches!(i.kind, ty::AssocKind::Type)
-                                })
-                            // Consider only accessible traits
-                            && tcx.visibility(*trait_def_id)
-                                .is_accessible_from(self.item_def_id(), tcx)
-                            && tcx.all_impls(*trait_def_id)
-                                .any(|impl_def_id| {
-                                    let trait_ref = tcx.impl_trait_ref(impl_def_id);
-                                    trait_ref.map_or(false, |trait_ref| {
-                                        let impl_ = trait_ref.subst(
-                                            tcx,
-                                            infcx.fresh_substs_for_item(span, impl_def_id),
-                                        );
-                                        infcx
-                                            .can_eq(
-                                                param_env,
-                                                tcx.erase_regions(impl_.self_ty()),
-                                                tcx.erase_regions(qself_ty),
-                                            )
-                                            .is_ok()
-                                    })
-                                    && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
-                                })
-                        })
-                        .map(|trait_def_id| tcx.def_path_str(trait_def_id))
-                        .collect();
+                    let traits: Vec<_> =
+                        self.probe_traits_that_match_assoc_ty(qself_ty, assoc_ident);
 
                     // Don't print `TyErr` to the user.
                     self.report_ambiguous_associated_type(
@@ -2232,6 +2194,60 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         Ok((ty, DefKind::AssocTy, assoc_ty_did))
     }
 
+    fn probe_traits_that_match_assoc_ty(
+        &self,
+        qself_ty: Ty<'tcx>,
+        assoc_ident: Ident,
+    ) -> Vec<String> {
+        let tcx = self.tcx();
+
+        // In contexts that have no inference context, just make a new one.
+        // We do need a local variable to store it, though.
+        let infcx_;
+        let infcx = if let Some(infcx) = self.infcx() {
+            infcx
+        } else {
+            assert!(!qself_ty.needs_infer());
+            infcx_ = tcx.infer_ctxt().build();
+            &infcx_
+        };
+
+        tcx.all_traits()
+            .filter(|trait_def_id| {
+                // Consider only traits with the associated type
+                tcx.associated_items(*trait_def_id)
+                        .in_definition_order()
+                        .any(|i| {
+                            i.kind.namespace() == Namespace::TypeNS
+                                && i.ident(tcx).normalize_to_macros_2_0() == assoc_ident
+                                && matches!(i.kind, ty::AssocKind::Type)
+                        })
+                    // Consider only accessible traits
+                    && tcx.visibility(*trait_def_id)
+                        .is_accessible_from(self.item_def_id(), tcx)
+                    && tcx.all_impls(*trait_def_id)
+                        .any(|impl_def_id| {
+                            let trait_ref = tcx.impl_trait_ref(impl_def_id);
+                            trait_ref.map_or(false, |trait_ref| {
+                                let impl_ = trait_ref.subst(
+                                    tcx,
+                                    infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id),
+                                );
+                                infcx
+                                    .can_eq(
+                                        ty::ParamEnv::empty(),
+                                        tcx.erase_regions(impl_.self_ty()),
+                                        tcx.erase_regions(qself_ty),
+                                    )
+                                    .is_ok()
+                            })
+                            && tcx.impl_polarity(impl_def_id) != ty::ImplPolarity::Negative
+                        })
+            })
+            .map(|trait_def_id| tcx.def_path_str(trait_def_id))
+            .collect()
+    }
+
     fn lookup_assoc_ty(
         &self,
         ident: Ident,
@@ -3124,8 +3140,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
         let hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), ident, .. }) =
             hir.get(fn_hir_id) else { return None };
-        let hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(i), .. }) =
-                hir.get_parent(fn_hir_id) else { bug!("ImplItem should have Impl parent") };
+        let i = hir.get_parent(fn_hir_id).expect_item().expect_impl();
 
         let trait_ref = self.instantiate_mono_trait_ref(
             i.of_trait.as_ref()?,
@@ -3140,7 +3155,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             trait_ref.def_id,
         )?;
 
-        let fn_sig = tcx.bound_fn_sig(assoc.def_id).subst(
+        let fn_sig = tcx.fn_sig(assoc.def_id).subst(
             tcx,
             trait_ref.substs.extend_to(tcx, assoc.def_id, |param, _| tcx.mk_param_from_def(param)),
         );
diff --git a/compiler/rustc_hir_analysis/src/autoderef.rs b/compiler/rustc_hir_analysis/src/autoderef.rs
index 730560cc686..a5c96a8b016 100644
--- a/compiler/rustc_hir_analysis/src/autoderef.rs
+++ b/compiler/rustc_hir_analysis/src/autoderef.rs
@@ -2,11 +2,11 @@ use crate::errors::AutoDerefReachedRecursionLimit;
 use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::NormalizeExt;
 use crate::traits::{self, TraitEngine, TraitEngineExt};
-use rustc_hir as hir;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::ty::TypeVisitable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::Limit;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::Span;
 
@@ -28,7 +28,7 @@ pub struct Autoderef<'a, 'tcx> {
     // Meta infos:
     infcx: &'a InferCtxt<'tcx>,
     span: Span,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
 
     // Current state:
@@ -96,14 +96,14 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
     pub fn new(
         infcx: &'a InferCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_def_id: LocalDefId,
         span: Span,
         base_ty: Ty<'tcx>,
     ) -> Autoderef<'a, 'tcx> {
         Autoderef {
             infcx,
             span,
-            body_id,
+            body_id: body_def_id,
             param_env,
             state: AutoderefSnapshot {
                 steps: vec![],
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index abc1c2d7b8d..6f4ebc987e6 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -14,7 +14,7 @@ use rustc_hir::{ItemKind, Node, PathSegment};
 use rustc_infer::infer::opaque_types::ConstrainOpaqueTypeRegionVisitor;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::{DefiningAnchor, RegionVariableOrigin, TyCtxtInferExt};
-use rustc_infer::traits::Obligation;
+use rustc_infer::traits::{Obligation, TraitEngineExt as _};
 use rustc_lint::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::stability::EvalResult;
@@ -28,7 +28,7 @@ use rustc_span::{self, Span};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::OnUnimplementedDirective;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
-use rustc_trait_selection::traits::{self, ObligationCtxt};
+use rustc_trait_selection::traits::{self, ObligationCtxt, TraitEngine, TraitEngineExt as _};
 
 use std::ops::ControlFlow;
 
@@ -412,7 +412,6 @@ fn check_opaque_meets_bounds<'tcx>(
     span: Span,
     origin: &hir::OpaqueTyOrigin,
 ) {
-    let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
     let defining_use_anchor = match *origin {
         hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did,
         hir::OpaqueTyOrigin::TyAlias => def_id,
@@ -438,7 +437,7 @@ fn check_opaque_meets_bounds<'tcx>(
         _ => re,
     });
 
-    let misc_cause = traits::ObligationCause::misc(span, hir_id);
+    let misc_cause = traits::ObligationCause::misc(span, def_id);
 
     match ocx.eq(&misc_cause, param_env, opaque_ty, hidden_ty) {
         Ok(()) => {}
@@ -666,7 +665,7 @@ fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
         DefKind::GlobalAsm => {
             let it = tcx.hir().item(id);
             let hir::ItemKind::GlobalAsm(asm) = it.kind else { span_bug!(it.span, "DefKind::GlobalAsm but got {:#?}", it) };
-            InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, id.hir_id());
+            InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, id.owner_id.def_id);
         }
         _ => {}
     }
@@ -1461,7 +1460,8 @@ fn opaque_type_cycle_error(
                 for def_id in visitor.opaques {
                     let ty_span = tcx.def_span(def_id);
                     if !seen.contains(&ty_span) {
-                        err.span_label(ty_span, &format!("returning this opaque type `{ty}`"));
+                        let descr = if ty.is_impl_trait() { "opaque " } else { "" };
+                        err.span_label(ty_span, &format!("returning this {descr}type `{ty}`"));
                         seen.insert(ty_span);
                     }
                     err.span_label(sp, &format!("returning here with type `{ty}`"));
@@ -1508,3 +1508,34 @@ fn opaque_type_cycle_error(
     }
     err.emit()
 }
+
+pub(super) fn check_generator_obligations(tcx: TyCtxt<'_>, def_id: LocalDefId) {
+    debug_assert!(tcx.sess.opts.unstable_opts.drop_tracking_mir);
+    debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Generator));
+
+    let typeck = tcx.typeck(def_id);
+    let param_env = tcx.param_env(def_id);
+
+    let generator_interior_predicates = &typeck.generator_interior_predicates[&def_id];
+    debug!(?generator_interior_predicates);
+
+    let infcx = tcx
+        .infer_ctxt()
+        // typeck writeback gives us predicates with their regions erased.
+        // As borrowck already has checked lifetimes, we do not need to do it again.
+        .ignoring_regions()
+        // Bind opaque types to `def_id` as they should have been checked by borrowck.
+        .with_opaque_type_inference(DefiningAnchor::Bind(def_id))
+        .build();
+
+    let mut fulfillment_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
+    for (predicate, cause) in generator_interior_predicates {
+        let obligation = Obligation::new(tcx, cause.clone(), param_env, *predicate);
+        fulfillment_cx.register_predicate_obligation(&infcx, obligation);
+    }
+    let errors = fulfillment_cx.select_all_or_error(&infcx);
+    debug!(?errors);
+    if !errors.is_empty() {
+        infcx.err_ctxt().report_fulfillment_errors(&errors, None);
+    }
+}
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index cfebcceef3c..3115f5f464a 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -8,7 +8,7 @@ use rustc_errors::{
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit;
-use rustc_hir::{GenericParamKind, ImplItemKind, TraitItemKind};
+use rustc_hir::{GenericParamKind, ImplItemKind};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
@@ -147,12 +147,12 @@ fn compare_method_predicate_entailment<'tcx>(
     //
     // FIXME(@lcnr): remove that after removing `cause.body_id` from
     // obligations.
-    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m.def_id.expect_local());
+    let impl_m_def_id = impl_m.def_id.expect_local();
     let cause = ObligationCause::new(
         impl_m_span,
-        impl_m_hir_id,
+        impl_m_def_id,
         ObligationCauseCode::CompareImplItemObligation {
-            impl_item_def_id: impl_m.def_id.expect_local(),
+            impl_item_def_id: impl_m_def_id,
             trait_item_def_id: trait_m.def_id,
             kind: impl_m.kind,
         },
@@ -198,7 +198,7 @@ fn compare_method_predicate_entailment<'tcx>(
     // Construct trait parameter environment and then shift it into the placeholder viewpoint.
     // The key step here is to update the caller_bounds's predicates to be
     // the new hybrid bounds we computed.
-    let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_hir_id);
+    let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_def_id);
     let param_env = ty::ParamEnv::new(
         tcx.intern_predicates(&hybrid_preds.predicates),
         Reveal::UserFacing,
@@ -213,14 +213,14 @@ fn compare_method_predicate_entailment<'tcx>(
 
     let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_placeholder_substs);
     for (predicate, span) in impl_m_own_bounds {
-        let normalize_cause = traits::ObligationCause::misc(span, impl_m_hir_id);
+        let normalize_cause = traits::ObligationCause::misc(span, impl_m_def_id);
         let predicate = ocx.normalize(&normalize_cause, param_env, predicate);
 
         let cause = ObligationCause::new(
             span,
-            impl_m_hir_id,
+            impl_m_def_id,
             ObligationCauseCode::CompareImplItemObligation {
-                impl_item_def_id: impl_m.def_id.expect_local(),
+                impl_item_def_id: impl_m_def_id,
                 trait_item_def_id: trait_m.def_id,
                 kind: impl_m.kind,
             },
@@ -249,15 +249,15 @@ fn compare_method_predicate_entailment<'tcx>(
     let unnormalized_impl_sig = infcx.replace_bound_vars_with_fresh_vars(
         impl_m_span,
         infer::HigherRankedType,
-        tcx.fn_sig(impl_m.def_id),
+        tcx.fn_sig(impl_m.def_id).subst_identity(),
     );
     let unnormalized_impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(unnormalized_impl_sig));
 
-    let norm_cause = ObligationCause::misc(impl_m_span, impl_m_hir_id);
+    let norm_cause = ObligationCause::misc(impl_m_span, impl_m_def_id);
     let impl_sig = ocx.normalize(&norm_cause, param_env, unnormalized_impl_sig);
     debug!("compare_impl_method: impl_fty={:?}", impl_sig);
 
-    let trait_sig = tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
+    let trait_sig = tcx.fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
     let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, trait_sig);
 
     // Next, add all inputs and output as well-formed tys. Importantly,
@@ -311,6 +311,7 @@ fn compare_method_predicate_entailment<'tcx>(
     if !errors.is_empty() {
         match check_implied_wf {
             CheckImpliedWfMode::Check => {
+                let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
                 return compare_method_predicate_entailment(
                     tcx,
                     impl_m,
@@ -336,7 +337,7 @@ fn compare_method_predicate_entailment<'tcx>(
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
         Some(infcx),
-        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys.clone()),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, wf_tys.clone()),
     );
     infcx.process_registered_region_obligations(
         outlives_env.region_bound_pairs(),
@@ -346,6 +347,7 @@ fn compare_method_predicate_entailment<'tcx>(
     if !errors.is_empty() {
         // FIXME(compiler-errors): This can be simplified when IMPLIED_BOUNDS_ENTAILMENT
         // becomes a hard error (i.e. ideally we'd just call `resolve_regions_and_report_errors`
+        let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
         match check_implied_wf {
             CheckImpliedWfMode::Check => {
                 return compare_method_predicate_entailment(
@@ -371,7 +373,7 @@ fn compare_method_predicate_entailment<'tcx>(
             }
             CheckImpliedWfMode::Skip => {
                 if infcx.tainted_by_errors().is_none() {
-                    infcx.err_ctxt().report_region_errors(impl_m.def_id.expect_local(), &errors);
+                    infcx.err_ctxt().report_region_errors(impl_m_def_id, &errors);
                 }
                 return Err(tcx
                     .sess
@@ -420,8 +422,8 @@ fn extract_bad_args_for_implies_lint<'tcx>(
 
     // Map late-bound regions from trait to impl, so the names are right.
     let mapping = std::iter::zip(
-        tcx.fn_sig(trait_m.def_id).bound_vars(),
-        tcx.fn_sig(impl_m.def_id).bound_vars(),
+        tcx.fn_sig(trait_m.def_id).skip_binder().bound_vars(),
+        tcx.fn_sig(impl_m.def_id).skip_binder().bound_vars(),
     )
     .filter_map(|(impl_bv, trait_bv)| {
         if let ty::BoundVariableKind::Region(impl_bv) = impl_bv
@@ -538,7 +540,7 @@ fn compare_asyncness<'tcx>(
     trait_item_span: Option<Span>,
 ) -> Result<(), ErrorGuaranteed> {
     if tcx.asyncness(trait_m.def_id) == hir::IsAsync::Async {
-        match tcx.fn_sig(impl_m.def_id).skip_binder().output().kind() {
+        match tcx.fn_sig(impl_m.def_id).skip_binder().skip_binder().output().kind() {
             ty::Alias(ty::Opaque, ..) => {
                 // allow both `async fn foo()` and `fn foo() -> impl Future`
             }
@@ -610,13 +612,14 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
 
     let trait_to_impl_substs = impl_trait_ref.substs;
 
-    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m.def_id.expect_local());
+    let impl_m_def_id = impl_m.def_id.expect_local();
+    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
     let return_span = tcx.hir().fn_decl_by_hir_id(impl_m_hir_id).unwrap().output.span();
     let cause = ObligationCause::new(
         return_span,
-        impl_m_hir_id,
+        impl_m_def_id,
         ObligationCauseCode::CompareImplItemObligation {
-            impl_item_def_id: impl_m.def_id.expect_local(),
+            impl_item_def_id: impl_m_def_id,
             trait_item_def_id: trait_m.def_id,
             kind: impl_m.kind,
         },
@@ -633,14 +636,14 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let ocx = ObligationCtxt::new(infcx);
 
     // Normalize the impl signature with fresh variables for lifetime inference.
-    let norm_cause = ObligationCause::misc(return_span, impl_m_hir_id);
+    let norm_cause = ObligationCause::misc(return_span, impl_m_def_id);
     let impl_sig = ocx.normalize(
         &norm_cause,
         param_env,
         infcx.replace_bound_vars_with_fresh_vars(
             return_span,
             infer::HigherRankedType,
-            tcx.fn_sig(impl_m.def_id),
+            tcx.fn_sig(impl_m.def_id).subst_identity(),
         ),
     );
     impl_sig.error_reported()?;
@@ -650,11 +653,11 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     // the ImplTraitInTraitCollector, which gathers all of the RPITITs and replaces
     // them with inference variables.
     // We will use these inference variables to collect the hidden types of RPITITs.
-    let mut collector = ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_hir_id);
+    let mut collector = ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_def_id);
     let unnormalized_trait_sig = tcx
         .liberate_late_bound_regions(
             impl_m.def_id,
-            tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
+            tcx.fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
         )
         .fold_with(&mut collector);
     let trait_sig = ocx.normalize(&norm_cause, param_env, unnormalized_trait_sig);
@@ -732,12 +735,11 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let outlives_environment = OutlivesEnvironment::with_bounds(
         param_env,
         Some(infcx),
-        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, wf_tys),
     );
-    infcx.err_ctxt().check_region_obligations_and_report_errors(
-        impl_m.def_id.expect_local(),
-        &outlives_environment,
-    )?;
+    infcx
+        .err_ctxt()
+        .check_region_obligations_and_report_errors(impl_m_def_id, &outlives_environment)?;
 
     let mut collected_tys = FxHashMap::default();
     for (def_id, (ty, substs)) in collector.types {
@@ -819,7 +821,7 @@ struct ImplTraitInTraitCollector<'a, 'tcx> {
     types: FxHashMap<DefId, (Ty<'tcx>, ty::SubstsRef<'tcx>)>,
     span: Span,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
 }
 
 impl<'a, 'tcx> ImplTraitInTraitCollector<'a, 'tcx> {
@@ -827,7 +829,7 @@ impl<'a, 'tcx> ImplTraitInTraitCollector<'a, 'tcx> {
         ocx: &'a ObligationCtxt<'a, 'tcx>,
         span: Span,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     ) -> Self {
         ImplTraitInTraitCollector { ocx, types: FxHashMap::default(), span, param_env, body_id }
     }
@@ -916,7 +918,7 @@ fn report_trait_method_mismatch<'tcx>(
             // When the `impl` receiver is an arbitrary self type, like `self: Box<Self>`, the
             // span points only at the type `Box<Self`>, but we want to cover the whole
             // argument pattern and type.
-            let ImplItemKind::Fn(ref sig, body) = tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind else { bug!("{impl_m:?} is not a method") };
+            let (sig, body) = tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).expect_fn();
             let span = tcx
                 .hir()
                 .body_param_names(body)
@@ -1078,12 +1080,12 @@ fn extract_spans_for_error_reporting<'tcx>(
 ) -> (Span, Option<Span>) {
     let tcx = infcx.tcx;
     let mut impl_args = {
-        let ImplItemKind::Fn(sig, _) = &tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind else { bug!("{:?} is not a method", impl_m) };
+        let (sig, _) = tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).expect_fn();
         sig.decl.inputs.iter().map(|t| t.span).chain(iter::once(sig.decl.output.span()))
     };
 
     let trait_args = trait_m.def_id.as_local().map(|def_id| {
-        let TraitItemKind::Fn(sig, _) = &tcx.hir().expect_trait_item(def_id).kind else { bug!("{:?} is not a TraitItemKind::Fn", trait_m) };
+        let (sig, _) = tcx.hir().expect_trait_item(def_id).expect_fn();
         sig.decl.inputs.iter().map(|t| t.span).chain(iter::once(sig.decl.output.span()))
     });
 
@@ -1115,7 +1117,7 @@ fn compare_self_type<'tcx>(
             ty::ImplContainer => impl_trait_ref.self_ty(),
             ty::TraitContainer => tcx.types.self_param,
         };
-        let self_arg_ty = tcx.fn_sig(method.def_id).input(0);
+        let self_arg_ty = tcx.fn_sig(method.def_id).subst_identity().input(0);
         let param_env = ty::ParamEnv::reveal_all();
 
         let infcx = tcx.infer_ctxt().build();
@@ -1348,15 +1350,15 @@ fn compare_number_of_method_arguments<'tcx>(
 ) -> Result<(), ErrorGuaranteed> {
     let impl_m_fty = tcx.fn_sig(impl_m.def_id);
     let trait_m_fty = tcx.fn_sig(trait_m.def_id);
-    let trait_number_args = trait_m_fty.inputs().skip_binder().len();
-    let impl_number_args = impl_m_fty.inputs().skip_binder().len();
+    let trait_number_args = trait_m_fty.skip_binder().inputs().skip_binder().len();
+    let impl_number_args = impl_m_fty.skip_binder().inputs().skip_binder().len();
 
     if trait_number_args != impl_number_args {
         let trait_span = trait_m
             .def_id
             .as_local()
             .and_then(|def_id| {
-                let TraitItemKind::Fn(trait_m_sig, _) = &tcx.hir().expect_trait_item(def_id).kind else { bug!("{:?} is not a method", impl_m) };
+                let (trait_m_sig, _) = &tcx.hir().expect_trait_item(def_id).expect_fn();
                 let pos = trait_number_args.saturating_sub(1);
                 trait_m_sig.decl.inputs.get(pos).map(|arg| {
                     if pos == 0 {
@@ -1368,7 +1370,7 @@ fn compare_number_of_method_arguments<'tcx>(
             })
             .or(trait_item_span);
 
-        let ImplItemKind::Fn(impl_m_sig, _) = &tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind else { bug!("{:?} is not a method", impl_m) };
+        let (impl_m_sig, _) = &tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).expect_fn();
         let pos = impl_number_args.saturating_sub(1);
         let impl_span = impl_m_sig
             .decl
@@ -1504,7 +1506,7 @@ fn compare_synthetic_generics<'tcx>(
                     let _: Option<_> = try {
                         let impl_m = impl_m.def_id.as_local()?;
                         let impl_m = tcx.hir().expect_impl_item(impl_m);
-                        let hir::ImplItemKind::Fn(sig, _) = &impl_m.kind else { unreachable!() };
+                        let (sig, _) = impl_m.expect_fn();
                         let input_tys = sig.decl.inputs;
 
                         struct Visitor(Option<Span>, hir::def_id::LocalDefId);
@@ -1671,14 +1673,12 @@ pub(super) fn compare_impl_const_raw(
 
     // Create a parameter environment that represents the implementation's
     // method.
-    let impl_c_hir_id = tcx.hir().local_def_id_to_hir_id(impl_const_item_def);
-
     // Compute placeholder form of impl and trait const tys.
     let impl_ty = tcx.type_of(impl_const_item_def.to_def_id());
     let trait_ty = tcx.bound_type_of(trait_const_item_def).subst(tcx, trait_to_impl_substs);
     let mut cause = ObligationCause::new(
         impl_c_span,
-        impl_c_hir_id,
+        impl_const_item_def,
         ObligationCauseCode::CompareImplItemObligation {
             impl_item_def_id: impl_const_item_def,
             trait_item_def_id: trait_const_item_def,
@@ -1704,7 +1704,7 @@ pub(super) fn compare_impl_const_raw(
         );
 
         // Locate the Span containing just the type of the offending impl
-        let ImplItemKind::Const(ty, _) = tcx.hir().expect_impl_item(impl_const_item_def).kind else { bug!("{impl_const_item:?} is not a impl const") };
+        let (ty, _) = tcx.hir().expect_impl_item(impl_const_item_def).expect_const();
         cause.span = ty.span;
 
         let mut diag = struct_span_err!(
@@ -1717,7 +1717,7 @@ pub(super) fn compare_impl_const_raw(
 
         let trait_c_span = trait_const_item_def.as_local().map(|trait_c_def_id| {
             // Add a label to the Span containing just the type of the const
-            let TraitItemKind::Const(ty, _) = tcx.hir().expect_trait_item(trait_c_def_id).kind else { bug!("{trait_const_item:?} is not a trait const") };
+            let (ty, _) = tcx.hir().expect_trait_item(trait_c_def_id).expect_const();
             ty.span
         });
 
@@ -1799,7 +1799,7 @@ fn compare_type_predicate_entailment<'tcx>(
     // This `HirId` should be used for the `body_id` field on each
     // `ObligationCause` (and the `FnCtxt`). This is what
     // `regionck_item` expects.
-    let impl_ty_hir_id = tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local());
+    let impl_ty_def_id = impl_ty.def_id.expect_local();
     debug!("compare_type_predicate_entailment: trait_to_impl_substs={:?}", trait_to_impl_substs);
 
     // The predicates declared by the impl definition, the trait and the
@@ -1814,7 +1814,7 @@ fn compare_type_predicate_entailment<'tcx>(
 
     debug!("compare_type_predicate_entailment: bounds={:?}", hybrid_preds);
 
-    let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_hir_id);
+    let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_def_id);
     let param_env = ty::ParamEnv::new(
         tcx.intern_predicates(&hybrid_preds.predicates),
         Reveal::UserFacing,
@@ -1827,12 +1827,12 @@ fn compare_type_predicate_entailment<'tcx>(
     debug!("compare_type_predicate_entailment: caller_bounds={:?}", param_env.caller_bounds());
 
     for (predicate, span) in impl_ty_own_bounds {
-        let cause = ObligationCause::misc(span, impl_ty_hir_id);
+        let cause = ObligationCause::misc(span, impl_ty_def_id);
         let predicate = ocx.normalize(&cause, param_env, predicate);
 
         let cause = ObligationCause::new(
             span,
-            impl_ty_hir_id,
+            impl_ty_def_id,
             ObligationCauseCode::CompareImplItemObligation {
                 impl_item_def_id: impl_ty.def_id.expect_local(),
                 trait_item_def_id: trait_ty.def_id,
@@ -2008,7 +2008,7 @@ pub(super) fn check_type_bounds<'tcx>(
     };
     debug!(?normalize_param_env);
 
-    let impl_ty_hir_id = tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local());
+    let impl_ty_def_id = impl_ty.def_id.expect_local();
     let impl_ty_substs = InternalSubsts::identity_for_item(tcx, impl_ty.def_id);
     let rebased_substs = impl_ty_substs.rebase_onto(tcx, container_id, impl_trait_ref.substs);
 
@@ -2020,7 +2020,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     let normalize_cause = ObligationCause::new(
         impl_ty_span,
-        impl_ty_hir_id,
+        impl_ty_def_id,
         ObligationCauseCode::CheckAssociatedTypeBounds {
             impl_item_def_id: impl_ty.def_id.expect_local(),
             trait_item_def_id: trait_ty.def_id,
@@ -2032,7 +2032,7 @@ pub(super) fn check_type_bounds<'tcx>(
         } else {
             traits::BindingObligation(trait_ty.def_id, span)
         };
-        ObligationCause::new(impl_ty_span, impl_ty_hir_id, code)
+        ObligationCause::new(impl_ty_span, impl_ty_def_id, code)
     };
 
     let obligations = tcx
@@ -2063,7 +2063,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     // Finally, resolve all regions. This catches wily misuses of
     // lifetime parameters.
-    let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_hir_id, assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_def_id, assumed_wf_types);
     let outlives_environment =
         OutlivesEnvironment::with_bounds(param_env, Some(&infcx), implied_bounds);
 
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
index 598dc2dca5c..955cacf03b1 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
@@ -56,8 +56,14 @@ fn equate_intrinsic_type<'tcx>(
         && gen_count_ok(own_counts.consts, 0, "const")
     {
         let fty = tcx.mk_fn_ptr(sig);
-        let cause = ObligationCause::new(it.span, it.hir_id(), ObligationCauseCode::IntrinsicType);
-        require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.fn_sig(it.owner_id)), fty);
+        let it_def_id = it.owner_id.def_id;
+        let cause = ObligationCause::new(it.span, it_def_id, ObligationCauseCode::IntrinsicType);
+        require_same_types(
+            tcx,
+            &cause,
+            tcx.mk_fn_ptr(tcx.fn_sig(it.owner_id).subst_identity()),
+            fty,
+        );
     }
 }
 
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
index 82030d82f57..122b6ead8e9 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
@@ -3,6 +3,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_middle::ty::{self, Article, FloatTy, IntTy, Ty, TyCtxt, TypeVisitable, UintTy};
 use rustc_session::lint;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{Symbol, DUMMY_SP};
 use rustc_target::asm::{InlineAsmReg, InlineAsmRegClass, InlineAsmRegOrRegClass, InlineAsmType};
 
@@ -253,10 +254,8 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
         Some(asm_ty)
     }
 
-    pub fn check_asm(&self, asm: &hir::InlineAsm<'tcx>, enclosing_id: hir::HirId) {
-        let hir = self.tcx.hir();
-        let enclosing_def_id = hir.local_def_id(enclosing_id).to_def_id();
-        let target_features = self.tcx.asm_target_features(enclosing_def_id);
+    pub fn check_asm(&self, asm: &hir::InlineAsm<'tcx>, enclosing_id: LocalDefId) {
+        let target_features = self.tcx.asm_target_features(enclosing_id.to_def_id());
         let Some(asm_arch) = self.tcx.sess.asm_arch else {
             self.tcx.sess.delay_span_bug(DUMMY_SP, "target architecture does not support asm");
             return;
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 14bca34b77b..bec693439a4 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -105,6 +105,7 @@ pub fn provide(providers: &mut Providers) {
         region_scope_tree,
         collect_return_position_impl_trait_in_trait_tys,
         compare_impl_const: compare_impl_item::compare_impl_const_raw,
+        check_generator_obligations: check::check_generator_obligations,
         ..*providers
     };
 }
@@ -445,7 +446,7 @@ fn suggestion_signature(assoc: &ty::AssocItem, tcx: TyCtxt<'_>) -> String {
             // regions just fine, showing `fn(&MyType)`.
             fn_sig_suggestion(
                 tcx,
-                tcx.fn_sig(assoc.def_id).skip_binder(),
+                tcx.fn_sig(assoc.def_id).subst_identity().skip_binder(),
                 assoc.ident(tcx),
                 tcx.predicates_of(assoc.def_id),
                 assoc,
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 11237afe8a0..5b9b57da382 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -37,7 +37,7 @@ use std::ops::{ControlFlow, Deref};
 pub(super) struct WfCheckingCtxt<'a, 'tcx> {
     pub(super) ocx: ObligationCtxt<'a, 'tcx>,
     span: Span,
-    body_id: hir::HirId,
+    body_def_id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
 }
 impl<'a, 'tcx> Deref for WfCheckingCtxt<'a, 'tcx> {
@@ -59,7 +59,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         T: TypeFoldable<'tcx>,
     {
         self.ocx.normalize(
-            &ObligationCause::new(span, self.body_id, ObligationCauseCode::WellFormed(loc)),
+            &ObligationCause::new(span, self.body_def_id, ObligationCauseCode::WellFormed(loc)),
             self.param_env,
             value,
         )
@@ -71,8 +71,11 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         loc: Option<WellFormedLoc>,
         arg: ty::GenericArg<'tcx>,
     ) {
-        let cause =
-            traits::ObligationCause::new(span, self.body_id, ObligationCauseCode::WellFormed(loc));
+        let cause = traits::ObligationCause::new(
+            span,
+            self.body_def_id,
+            ObligationCauseCode::WellFormed(loc),
+        );
         // for a type to be WF, we do not need to check if const trait predicates satisfy.
         let param_env = self.param_env.without_const();
         self.ocx.register_obligation(traits::Obligation::new(
@@ -93,11 +96,10 @@ pub(super) fn enter_wf_checking_ctxt<'tcx, F>(
     F: for<'a> FnOnce(&WfCheckingCtxt<'a, 'tcx>),
 {
     let param_env = tcx.param_env(body_def_id);
-    let body_id = tcx.hir().local_def_id_to_hir_id(body_def_id);
     let infcx = &tcx.infer_ctxt().build();
     let ocx = ObligationCtxt::new(infcx);
 
-    let mut wfcx = WfCheckingCtxt { ocx, span, body_id, param_env };
+    let mut wfcx = WfCheckingCtxt { ocx, span, body_def_id, param_env };
 
     if !tcx.features().trivial_bounds {
         wfcx.check_false_global_bounds()
@@ -105,7 +107,7 @@ pub(super) fn enter_wf_checking_ctxt<'tcx, F>(
     f(&mut wfcx);
 
     let assumed_wf_types = wfcx.ocx.assumed_wf_types(param_env, span, body_def_id);
-    let implied_bounds = infcx.implied_bounds_tys(param_env, body_id, assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, body_def_id, assumed_wf_types);
 
     let errors = wfcx.select_all_or_error();
     if !errors.is_empty() {
@@ -374,7 +376,6 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                     continue;
                 }
 
-                let item_hir_id = item.id.hir_id();
                 let param_env = tcx.param_env(item_def_id);
 
                 let item_required_bounds = match item.kind {
@@ -385,12 +386,12 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                         // `Self::Iter<'a>` is a GAT we want to gather any potential missing bounds from.
                         let sig: ty::FnSig<'_> = tcx.liberate_late_bound_regions(
                             item_def_id.to_def_id(),
-                            tcx.fn_sig(item_def_id),
+                            tcx.fn_sig(item_def_id).subst_identity(),
                         );
                         gather_gat_bounds(
                             tcx,
                             param_env,
-                            item_hir_id,
+                            item_def_id,
                             sig.inputs_and_output,
                             // We also assume that all of the function signature's parameter types
                             // are well formed.
@@ -412,7 +413,7 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                         gather_gat_bounds(
                             tcx,
                             param_env,
-                            item_hir_id,
+                            item_def_id,
                             tcx.explicit_item_bounds(item_def_id).to_vec(),
                             &FxIndexSet::default(),
                             gat_def_id.def_id,
@@ -458,7 +459,6 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
         let gat_item_hir = tcx.hir().expect_trait_item(gat_def_id.def_id);
         debug!(?required_bounds);
         let param_env = tcx.param_env(gat_def_id);
-        let gat_hir = gat_item_hir.hir_id();
 
         let mut unsatisfied_bounds: Vec<_> = required_bounds
             .into_iter()
@@ -466,13 +466,25 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                 ty::PredicateKind::Clause(ty::Clause::RegionOutlives(ty::OutlivesPredicate(
                     a,
                     b,
-                ))) => {
-                    !region_known_to_outlive(tcx, gat_hir, param_env, &FxIndexSet::default(), a, b)
-                }
+                ))) => !region_known_to_outlive(
+                    tcx,
+                    gat_def_id.def_id,
+                    param_env,
+                    &FxIndexSet::default(),
+                    a,
+                    b,
+                ),
                 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
                     a,
                     b,
-                ))) => !ty_known_to_outlive(tcx, gat_hir, param_env, &FxIndexSet::default(), a, b),
+                ))) => !ty_known_to_outlive(
+                    tcx,
+                    gat_def_id.def_id,
+                    param_env,
+                    &FxIndexSet::default(),
+                    a,
+                    b,
+                ),
                 _ => bug!("Unexpected PredicateKind"),
             })
             .map(|clause| clause.to_string())
@@ -551,7 +563,7 @@ fn augment_param_env<'tcx>(
 fn gather_gat_bounds<'tcx, T: TypeFoldable<'tcx>>(
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    item_hir: hir::HirId,
+    item_def_id: hir::OwnerId,
     to_check: T,
     wf_tys: &FxIndexSet<Ty<'tcx>>,
     gat_def_id: LocalDefId,
@@ -584,7 +596,7 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<'tcx>>(
         // reflected in a where clause on the GAT itself.
         for (ty, ty_idx) in &types {
             // In our example, requires that `Self: 'a`
-            if ty_known_to_outlive(tcx, item_hir, param_env, &wf_tys, *ty, *region_a) {
+            if ty_known_to_outlive(tcx, item_def_id.def_id, param_env, &wf_tys, *ty, *region_a) {
                 debug!(?ty_idx, ?region_a_idx);
                 debug!("required clause: {ty} must outlive {region_a}");
                 // Translate into the generic parameters of the GAT. In
@@ -622,7 +634,14 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<'tcx>>(
             if ty::ReStatic == **region_b || region_a == region_b {
                 continue;
             }
-            if region_known_to_outlive(tcx, item_hir, param_env, &wf_tys, *region_a, *region_b) {
+            if region_known_to_outlive(
+                tcx,
+                item_def_id.def_id,
+                param_env,
+                &wf_tys,
+                *region_a,
+                *region_b,
+            ) {
                 debug!(?region_a_idx, ?region_b_idx);
                 debug!("required clause: {region_a} must outlive {region_b}");
                 // Translate into the generic parameters of the GAT.
@@ -658,7 +677,7 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<'tcx>>(
 /// `ty` outlives `region`.
 fn ty_known_to_outlive<'tcx>(
     tcx: TyCtxt<'tcx>,
-    id: hir::HirId,
+    id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
     wf_tys: &FxIndexSet<Ty<'tcx>>,
     ty: Ty<'tcx>,
@@ -675,7 +694,7 @@ fn ty_known_to_outlive<'tcx>(
 /// `region_a` outlives `region_b`
 fn region_known_to_outlive<'tcx>(
     tcx: TyCtxt<'tcx>,
-    id: hir::HirId,
+    id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
     wf_tys: &FxIndexSet<Ty<'tcx>>,
     region_a: ty::Region<'tcx>,
@@ -699,7 +718,7 @@ fn region_known_to_outlive<'tcx>(
 /// to be tested), then resolve region and return errors
 fn resolve_regions_with_wf_tys<'tcx>(
     tcx: TyCtxt<'tcx>,
-    id: hir::HirId,
+    id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
     wf_tys: &FxIndexSet<Ty<'tcx>>,
     add_constraints: impl for<'a> FnOnce(&'a InferCtxt<'tcx>, &'a RegionBoundPairs<'tcx>),
@@ -822,7 +841,7 @@ fn check_object_unsafe_self_trait_by_name(tcx: TyCtxt<'_>, item: &hir::TraitItem
         _ => {}
     }
     if !trait_should_be_self.is_empty() {
-        if tcx.object_safety_violations(trait_def_id).is_empty() {
+        if tcx.check_is_object_safe(trait_def_id) {
             return;
         }
         let sugg = trait_should_be_self.iter().map(|span| (*span, "Self".to_string())).collect();
@@ -1006,7 +1025,7 @@ fn check_associated_item(
                 wfcx.register_wf_obligation(span, loc, ty.into());
             }
             ty::AssocKind::Fn => {
-                let sig = tcx.fn_sig(item.def_id);
+                let sig = tcx.fn_sig(item.def_id).subst_identity();
                 let hir_sig = sig_if_method.expect("bad signature for method");
                 check_fn_or_method(
                     wfcx,
@@ -1053,8 +1072,8 @@ fn check_type_defn<'tcx>(tcx: TyCtxt<'tcx>, item: &hir::Item<'tcx>, all_sized: b
             // All field types must be well-formed.
             for field in &variant.fields {
                 let field_id = field.did.expect_local();
-                let hir::Node::Field(hir::FieldDef { ty: hir_ty, .. }) = tcx.hir().get_by_def_id(field_id)
-                else { bug!() };
+                let hir::FieldDef { ty: hir_ty, .. } =
+                    tcx.hir().get_by_def_id(field_id).expect_field();
                 let ty = wfcx.normalize(hir_ty.span, None, tcx.type_of(field.did));
                 wfcx.register_wf_obligation(
                     hir_ty.span,
@@ -1087,13 +1106,13 @@ fn check_type_defn<'tcx>(tcx: TyCtxt<'tcx>, item: &hir::Item<'tcx>, all_sized: b
             {
                 let last = idx == variant.fields.len() - 1;
                 let field_id = field.did.expect_local();
-                let hir::Node::Field(hir::FieldDef { ty: hir_ty, .. }) = tcx.hir().get_by_def_id(field_id)
-                else { bug!() };
+                let hir::FieldDef { ty: hir_ty, .. } =
+                    tcx.hir().get_by_def_id(field_id).expect_field();
                 let ty = wfcx.normalize(hir_ty.span, None, tcx.type_of(field.did));
                 wfcx.register_bound(
                     traits::ObligationCause::new(
                         hir_ty.span,
-                        wfcx.body_id,
+                        wfcx.body_def_id,
                         traits::FieldSized {
                             adt_kind: match item_adt_kind(&item.kind) {
                                 Some(i) => i,
@@ -1113,7 +1132,7 @@ fn check_type_defn<'tcx>(tcx: TyCtxt<'tcx>, item: &hir::Item<'tcx>, all_sized: b
             if let ty::VariantDiscr::Explicit(discr_def_id) = variant.discr {
                 let cause = traits::ObligationCause::new(
                     tcx.def_span(discr_def_id),
-                    wfcx.body_id,
+                    wfcx.body_def_id,
                     traits::MiscObligation,
                 );
                 wfcx.register_obligation(traits::Obligation::new(
@@ -1174,7 +1193,7 @@ fn check_associated_type_bounds(wfcx: &WfCheckingCtxt<'_, '_>, item: &ty::AssocI
         traits::wf::predicate_obligations(
             wfcx.infcx,
             wfcx.param_env,
-            wfcx.body_id,
+            wfcx.body_def_id,
             normalized_bound,
             bound_span,
         )
@@ -1191,7 +1210,7 @@ fn check_item_fn(
     decl: &hir::FnDecl<'_>,
 ) {
     enter_wf_checking_ctxt(tcx, span, def_id, |wfcx| {
-        let sig = tcx.fn_sig(def_id);
+        let sig = tcx.fn_sig(def_id).subst_identity();
         check_fn_or_method(wfcx, ident.span, sig, decl, def_id);
     })
 }
@@ -1214,7 +1233,7 @@ fn check_item_type(tcx: TyCtxt<'_>, item_id: LocalDefId, ty_span: Span, allow_fo
         wfcx.register_wf_obligation(ty_span, Some(WellFormedLoc::Ty(item_id)), item_ty.into());
         if forbid_unsized {
             wfcx.register_bound(
-                traits::ObligationCause::new(ty_span, wfcx.body_id, traits::WellFormed(None)),
+                traits::ObligationCause::new(ty_span, wfcx.body_def_id, traits::WellFormed(None)),
                 wfcx.param_env,
                 item_ty,
                 tcx.require_lang_item(LangItem::Sized, None),
@@ -1229,7 +1248,7 @@ fn check_item_type(tcx: TyCtxt<'_>, item_id: LocalDefId, ty_span: Span, allow_fo
 
         if should_check_for_sync {
             wfcx.register_bound(
-                traits::ObligationCause::new(ty_span, wfcx.body_id, traits::SharedStatic),
+                traits::ObligationCause::new(ty_span, wfcx.body_def_id, traits::SharedStatic),
                 wfcx.param_env,
                 item_ty,
                 tcx.require_lang_item(LangItem::Sync, Some(ty_span)),
@@ -1269,7 +1288,7 @@ fn check_impl<'tcx>(
                 let mut obligations = traits::wf::trait_obligations(
                     wfcx.infcx,
                     wfcx.param_env,
-                    wfcx.body_id,
+                    wfcx.body_def_id,
                     &trait_pred,
                     ast_trait_ref.path.span,
                     item,
@@ -1466,7 +1485,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             let pred = wfcx.normalize(sp, None, pred);
             let cause = traits::ObligationCause::new(
                 sp,
-                wfcx.body_id,
+                wfcx.body_def_id,
                 traits::ItemObligation(def_id.to_def_id()),
             );
             traits::Obligation::new(tcx, cause, wfcx.param_env, pred)
@@ -1482,12 +1501,11 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
         traits::wf::predicate_obligations(
             infcx,
             wfcx.param_env.without_const(),
-            wfcx.body_id,
+            wfcx.body_def_id,
             p,
             sp,
         )
     });
-
     let obligations: Vec<_> = wf_obligations.chain(default_obligations).collect();
     wfcx.register_obligations(obligations);
 }
@@ -1549,7 +1567,7 @@ fn check_fn_or_method<'tcx>(
         // Check that the argument is a tuple
         if let Some(ty) = inputs.next() {
             wfcx.register_bound(
-                ObligationCause::new(span, wfcx.body_id, ObligationCauseCode::RustCall),
+                ObligationCause::new(span, wfcx.body_def_id, ObligationCauseCode::RustCall),
                 wfcx.param_env,
                 *ty,
                 tcx.require_lang_item(hir::LangItem::Tuple, Some(span)),
@@ -1597,7 +1615,7 @@ fn check_return_position_impl_trait_in_trait_bounds<'tcx>(
                     traits::wf::predicate_obligations(
                         wfcx.infcx,
                         wfcx.param_env,
-                        wfcx.body_id,
+                        wfcx.body_def_id,
                         normalized_bound,
                         bound_span,
                     )
@@ -1627,7 +1645,7 @@ fn check_method_receiver<'tcx>(
 
     let span = fn_sig.decl.inputs[0].span;
 
-    let sig = tcx.fn_sig(method.def_id);
+    let sig = tcx.fn_sig(method.def_id).subst_identity();
     let sig = tcx.liberate_late_bound_regions(method.def_id, sig);
     let sig = wfcx.normalize(span, None, sig);
 
@@ -1697,7 +1715,7 @@ fn receiver_is_valid<'tcx>(
     let infcx = wfcx.infcx;
     let tcx = wfcx.tcx();
     let cause =
-        ObligationCause::new(span, wfcx.body_id, traits::ObligationCauseCode::MethodReceiver);
+        ObligationCause::new(span, wfcx.body_def_id, traits::ObligationCauseCode::MethodReceiver);
 
     let can_eq_self = |ty| infcx.can_eq(wfcx.param_env, self_ty, ty).is_ok();
 
@@ -1709,7 +1727,7 @@ fn receiver_is_valid<'tcx>(
         return true;
     }
 
-    let mut autoderef = Autoderef::new(infcx, wfcx.param_env, wfcx.body_id, span, receiver_ty);
+    let mut autoderef = Autoderef::new(infcx, wfcx.param_env, wfcx.body_def_id, span, receiver_ty);
 
     // The `arbitrary_self_types` feature allows raw pointer receivers like `self: *const Self`.
     if arbitrary_self_types_enabled {
@@ -1894,8 +1912,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         let mut span = self.span;
         let empty_env = ty::ParamEnv::empty();
 
-        let def_id = tcx.hir().local_def_id(self.body_id);
-        let predicates_with_span = tcx.predicates_of(def_id).predicates.iter().copied();
+        let predicates_with_span = tcx.predicates_of(self.body_def_id).predicates.iter().copied();
         // Check elaborated bounds.
         let implied_obligations = traits::elaborate_predicates_with_span(tcx, predicates_with_span);
 
@@ -1910,7 +1927,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
             // Match the existing behavior.
             if pred.is_global() && !pred.has_late_bound_vars() {
                 let pred = self.normalize(span, None, pred);
-                let hir_node = tcx.hir().find(self.body_id);
+                let hir_node = tcx.hir().find_by_def_id(self.body_def_id);
 
                 // only use the span of the predicate clause (#90869)
 
@@ -1929,7 +1946,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
 
                 let obligation = traits::Obligation::new(
                     tcx,
-                    traits::ObligationCause::new(span, self.body_id, traits::TrivialBound),
+                    traits::ObligationCause::new(span, self.body_def_id, traits::TrivialBound),
                     empty_env,
                     pred,
                 );
diff --git a/compiler/rustc_hir_analysis/src/check_unused.rs b/compiler/rustc_hir_analysis/src/check_unused.rs
index ebb78213a63..5716be4f1a9 100644
--- a/compiler/rustc_hir_analysis/src/check_unused.rs
+++ b/compiler/rustc_hir_analysis/src/check_unused.rs
@@ -29,7 +29,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         if item.span.is_dummy() {
             continue;
         }
-        let hir::ItemKind::Use(path, _) = item.kind else { unreachable!() };
+        let (path, _) = item.expect_use();
         let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) {
             format!("unused import: `{}`", snippet)
         } else {
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 28c04087868..6600e4216bd 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -56,7 +56,7 @@ fn visit_implementation_of_drop(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
         _ => {}
     }
 
-    let ItemKind::Impl(impl_) = tcx.hir().expect_item(impl_did).kind else { bug!("expected Drop impl item") };
+    let impl_ = tcx.hir().expect_item(impl_did).expect_impl();
 
     tcx.sess.emit_err(DropImplOnWrongItem { span: impl_.self_ty.span });
 }
@@ -64,8 +64,6 @@ fn visit_implementation_of_drop(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
 fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
     debug!("visit_implementation_of_copy: impl_did={:?}", impl_did);
 
-    let impl_hir_id = tcx.hir().local_def_id_to_hir_id(impl_did);
-
     let self_type = tcx.type_of(impl_did);
     debug!("visit_implementation_of_copy: self_type={:?} (bound)", self_type);
 
@@ -80,7 +78,7 @@ fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
         _ => bug!("expected Copy impl item"),
     };
 
-    let cause = traits::ObligationCause::misc(span, impl_hir_id);
+    let cause = traits::ObligationCause::misc(span, impl_did);
     match type_allowed_to_implement_copy(tcx, param_env, self_type, cause) {
         Ok(()) => {}
         Err(CopyImplementationError::InfrigingFields(fields)) => {
@@ -224,7 +222,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
     let create_err = |msg: &str| struct_span_err!(tcx.sess, span, E0378, "{}", msg);
 
     let infcx = tcx.infer_ctxt().build();
-    let cause = ObligationCause::misc(span, impl_hir_id);
+    let cause = ObligationCause::misc(span, impl_did);
 
     use rustc_type_ir::sty::TyKind::*;
     match (source.kind(), target.kind()) {
@@ -386,8 +384,7 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUn
     debug!("visit_implementation_of_coerce_unsized: {:?} -> {:?} (free)", source, target);
 
     let infcx = tcx.infer_ctxt().build();
-    let impl_hir_id = tcx.hir().local_def_id_to_hir_id(impl_did);
-    let cause = ObligationCause::misc(span, impl_hir_id);
+    let cause = ObligationCause::misc(span, impl_did);
     let check_mutbl = |mt_a: ty::TypeAndMut<'tcx>,
                        mt_b: ty::TypeAndMut<'tcx>,
                        mk_ptr: &dyn Fn(Ty<'tcx>) -> Ty<'tcx>| {
@@ -575,7 +572,7 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUn
     };
 
     // Register an obligation for `A: Trait<B>`.
-    let cause = traits::ObligationCause::misc(span, impl_hir_id);
+    let cause = traits::ObligationCause::misc(span, impl_did);
     let predicate =
         predicate_for_trait_def(tcx, param_env, cause, trait_def_id, 0, [source, target]);
     let errors = traits::fully_solve_obligation(&infcx, predicate);
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
index dfb98240943..c1b0237b2d1 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
@@ -240,6 +240,7 @@ impl<'tcx> InherentCollect<'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Bound(..)
             | ty::Placeholder(_)
             | ty::Infer(_) => {
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs
index d3b5778ba3b..bbde59c953a 100644
--- a/compiler/rustc_hir_analysis/src/coherence/mod.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs
@@ -169,7 +169,7 @@ fn check_object_overlap<'tcx>(
         });
 
         for component_def_id in component_def_ids {
-            if !tcx.is_object_safe(component_def_id) {
+            if !tcx.check_is_object_safe(component_def_id) {
                 // Without the 'object_safe_for_dispatch' feature this is an error
                 // which will be reported by wfcheck. Ignore it here.
                 // This is tested by `coherence-impl-trait-for-trait-object-safe.rs`.
diff --git a/compiler/rustc_hir_analysis/src/coherence/unsafety.rs b/compiler/rustc_hir_analysis/src/coherence/unsafety.rs
index fe6119dce87..c6b16171311 100644
--- a/compiler/rustc_hir_analysis/src/coherence/unsafety.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/unsafety.rs
@@ -3,15 +3,13 @@
 
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
-use rustc_hir::def::DefKind;
 use rustc_hir::Unsafety;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::LocalDefId;
 
 pub(super) fn check_item(tcx: TyCtxt<'_>, def_id: LocalDefId) {
-    debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Impl));
     let item = tcx.hir().expect_item(def_id);
-    let hir::ItemKind::Impl(impl_) = item.kind else { bug!() };
+    let impl_ = item.expect_impl();
 
     if let Some(trait_ref) = tcx.impl_trait_ref(item.owner_id) {
         let trait_ref = trait_ref.subst_identity();
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index c17778ce8bc..cc7235a61c0 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -25,7 +25,7 @@ use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{GenericParamKind, Node};
-use rustc_infer::infer::TyCtxtInferExt;
+use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::query::Providers;
@@ -517,6 +517,10 @@ impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> {
     fn record_ty(&self, _hir_id: hir::HirId, _ty: Ty<'tcx>, _span: Span) {
         // There's no place to record types from signatures?
     }
+
+    fn infcx(&self) -> Option<&InferCtxt<'tcx>> {
+        None
+    }
 }
 
 /// Synthesize a new lifetime name that doesn't clash with any of the lifetimes already present.
@@ -1087,7 +1091,7 @@ pub fn get_infer_ret_ty<'hir>(output: &'hir hir::FnRetTy<'hir>) -> Option<&'hir
 }
 
 #[instrument(level = "debug", skip(tcx))]
-fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
+fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'_>> {
     use rustc_hir::Node::*;
     use rustc_hir::*;
 
@@ -1096,7 +1100,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
 
     let icx = ItemCtxt::new(tcx, def_id.to_def_id());
 
-    match tcx.hir().get(hir_id) {
+    let output = match tcx.hir().get(hir_id) {
         TraitItem(hir::TraitItem {
             kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)),
             generics,
@@ -1169,7 +1173,8 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
         x => {
             bug!("unexpected sort of node in fn_sig(): {:?}", x);
         }
-    }
+    };
+    ty::EarlyBinder(output)
 }
 
 fn infer_return_ty_for_fn_sig<'tcx>(
@@ -1248,11 +1253,12 @@ fn infer_return_ty_for_fn_sig<'tcx>(
     }
 }
 
+// FIXME(vincenzopalazzo): remove the hir item when the refactoring is stable
 fn suggest_impl_trait<'tcx>(
     tcx: TyCtxt<'tcx>,
     ret_ty: Ty<'tcx>,
     span: Span,
-    hir_id: hir::HirId,
+    _hir_id: hir::HirId,
     def_id: LocalDefId,
 ) -> Option<String> {
     let format_as_assoc: fn(_, _, _, _, _) -> _ =
@@ -1324,7 +1330,7 @@ fn suggest_impl_trait<'tcx>(
         }
         let ocx = ObligationCtxt::new_in_snapshot(&infcx);
         let item_ty = ocx.normalize(
-            &ObligationCause::misc(span, hir_id),
+            &ObligationCause::misc(span, def_id),
             param_env,
             tcx.mk_projection(assoc_item_def_id, substs),
         );
@@ -1342,8 +1348,7 @@ fn suggest_impl_trait<'tcx>(
 
 fn impl_trait_ref(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::EarlyBinder<ty::TraitRef<'_>>> {
     let icx = ItemCtxt::new(tcx, def_id);
-    let item = tcx.hir().expect_item(def_id.expect_local());
-    let hir::ItemKind::Impl(impl_) = item.kind else { bug!() };
+    let impl_ = tcx.hir().expect_item(def_id.expect_local()).expect_impl();
     impl_
         .of_trait
         .as_ref()
diff --git a/compiler/rustc_hir_analysis/src/collect/lifetimes.rs b/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
index 359122d4e16..3c67722b637 100644
--- a/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
+++ b/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
@@ -829,7 +829,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         fd: &'tcx hir::FnDecl<'tcx>,
         body_id: hir::BodyId,
         _: Span,
-        _: hir::HirId,
+        _: LocalDefId,
     ) {
         let output = match fd.output {
             hir::FnRetTy::DefaultReturn(_) => None,
@@ -1264,14 +1264,21 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             } else if let Some(body_id) = outermost_body {
                 let fn_id = self.tcx.hir().body_owner(body_id);
                 match self.tcx.hir().get(fn_id) {
-                    Node::Item(hir::Item { kind: hir::ItemKind::Fn(..), .. })
+                    Node::Item(hir::Item { owner_id, kind: hir::ItemKind::Fn(..), .. })
                     | Node::TraitItem(hir::TraitItem {
-                        kind: hir::TraitItemKind::Fn(..), ..
+                        owner_id,
+                        kind: hir::TraitItemKind::Fn(..),
+                        ..
                     })
-                    | Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. })
-                    | Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => {
-                        let scope = self.tcx.hir().local_def_id(fn_id);
-                        def = Region::Free(scope.to_def_id(), def.id().unwrap());
+                    | Node::ImplItem(hir::ImplItem {
+                        owner_id,
+                        kind: hir::ImplItemKind::Fn(..),
+                        ..
+                    }) => {
+                        def = Region::Free(owner_id.to_def_id(), def.id().unwrap());
+                    }
+                    Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(closure), .. }) => {
+                        def = Region::Free(closure.def_id.to_def_id(), def.id().unwrap());
                     }
                     _ => {}
                 }
@@ -1658,10 +1665,12 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
 /// "Constrained" basically means that it appears in any type but
 /// not amongst the inputs to a projection. In other words, `<&'a
 /// T as Trait<''b>>::Foo` does not constrain `'a` or `'b`.
-fn is_late_bound_map(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<&FxIndexSet<LocalDefId>> {
-    let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-    let decl = tcx.hir().fn_decl_by_hir_id(hir_id)?;
-    let generics = tcx.hir().get_generics(def_id)?;
+fn is_late_bound_map(
+    tcx: TyCtxt<'_>,
+    owner_id: hir::OwnerId,
+) -> Option<&FxIndexSet<hir::ItemLocalId>> {
+    let decl = tcx.hir().fn_decl_by_hir_id(owner_id.into())?;
+    let generics = tcx.hir().get_generics(owner_id.def_id)?;
 
     let mut late_bound = FxIndexSet::default();
 
@@ -1695,24 +1704,22 @@ fn is_late_bound_map(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<&FxIndexSet<
             hir::GenericParamKind::Type { .. } | hir::GenericParamKind::Const { .. } => continue,
         }
 
-        let param_def_id = tcx.hir().local_def_id(param.hir_id);
-
         // appears in the where clauses? early-bound.
-        if appears_in_where_clause.regions.contains(&param_def_id) {
+        if appears_in_where_clause.regions.contains(&param.def_id) {
             continue;
         }
 
         // does not appear in the inputs, but appears in the return type? early-bound.
-        if !constrained_by_input.regions.contains(&param_def_id)
-            && appears_in_output.regions.contains(&param_def_id)
+        if !constrained_by_input.regions.contains(&param.def_id)
+            && appears_in_output.regions.contains(&param.def_id)
         {
             continue;
         }
 
-        debug!("lifetime {:?} with id {:?} is late-bound", param.name.ident(), param.hir_id);
+        debug!("lifetime {:?} with id {:?} is late-bound", param.name.ident(), param.def_id);
 
-        let inserted = late_bound.insert(param_def_id);
-        assert!(inserted, "visited lifetime {:?} twice", param.hir_id);
+        let inserted = late_bound.insert(param.hir_id.local_id);
+        assert!(inserted, "visited lifetime {:?} twice", param.def_id);
     }
 
     debug!(?late_bound);
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 46b277d9803..d0d67ae9257 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -280,7 +280,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
             }
 
             let hir::GenericParamKind::Lifetime { .. } = duplicate.kind else { continue };
-            let dup_def = tcx.hir().local_def_id(duplicate.hir_id).to_def_id();
+            let dup_def = duplicate.def_id.to_def_id();
 
             let Some(dup_index) = generics.param_def_id_to_index(tcx, dup_def) else { bug!() };
 
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs
index 5e388a2f2ba..e7b0846e103 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of.rs
@@ -54,15 +54,14 @@ pub(super) fn opt_const_param_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<
             // ty which is a fully resolved projection.
             // For the code example above, this would mean converting Self::Assoc<3>
             // into a ty::Alias(ty::Projection, <Self as Foo>::Assoc<3>)
-            let item_hir_id = tcx
+            let item_def_id = tcx
                 .hir()
-                .parent_iter(hir_id)
-                .filter(|(_, node)| matches!(node, Node::Item(_)))
-                .map(|(id, _)| id)
-                .next()
-                .unwrap();
-            let item_did = tcx.hir().local_def_id(item_hir_id).to_def_id();
-            let item_ctxt = &ItemCtxt::new(tcx, item_did) as &dyn crate::astconv::AstConv<'_>;
+                .parent_owner_iter(hir_id)
+                .find(|(_, node)| matches!(node, OwnerNode::Item(_)))
+                .unwrap()
+                .0
+                .to_def_id();
+            let item_ctxt = &ItemCtxt::new(tcx, item_def_id) as &dyn crate::astconv::AstConv<'_>;
             let ty = item_ctxt.ast_ty_to_ty(hir_ty);
 
             // Iterate through the generics of the projection to find the one that corresponds to
@@ -867,7 +866,9 @@ fn infer_placeholder_type<'a>(
             }
 
             match ty.kind() {
-                ty::FnDef(def_id, _) => self.tcx.mk_fn_ptr(self.tcx.fn_sig(*def_id)),
+                ty::FnDef(def_id, substs) => {
+                    self.tcx.mk_fn_ptr(self.tcx.fn_sig(*def_id).subst(self.tcx, substs))
+                }
                 // FIXME: non-capturing closures should also suggest a function pointer
                 ty::Closure(..) | ty::Generator(..) => {
                     self.success = false;
diff --git a/compiler/rustc_hir_analysis/src/hir_wf_check.rs b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
index 17dbb126bd1..9cf82b39ec9 100644
--- a/compiler/rustc_hir_analysis/src/hir_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
@@ -1,11 +1,12 @@
 use crate::collect::ItemCtxt;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{ForeignItem, ForeignItemKind, HirId};
+use rustc_hir::{ForeignItem, ForeignItemKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{ObligationCause, WellFormedLoc};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Region, TyCtxt, TypeFoldable, TypeFolder};
+use rustc_span::def_id::LocalDefId;
 use rustc_trait_selection::traits;
 
 pub fn provide(providers: &mut Providers) {
@@ -57,7 +58,7 @@ fn diagnostic_hir_wf_check<'tcx>(
         cause: Option<ObligationCause<'tcx>>,
         cause_depth: usize,
         icx: ItemCtxt<'tcx>,
-        hir_id: HirId,
+        def_id: LocalDefId,
         param_env: ty::ParamEnv<'tcx>,
         depth: usize,
     }
@@ -68,7 +69,7 @@ fn diagnostic_hir_wf_check<'tcx>(
             let tcx_ty = self.icx.to_ty(ty).fold_with(&mut EraseAllBoundRegions { tcx: self.tcx });
             let cause = traits::ObligationCause::new(
                 ty.span,
-                self.hir_id,
+                self.def_id,
                 traits::ObligationCauseCode::WellFormed(None),
             );
             let errors = traits::fully_solve_obligation(
@@ -106,7 +107,7 @@ fn diagnostic_hir_wf_check<'tcx>(
         cause: None,
         cause_depth: 0,
         icx,
-        hir_id,
+        def_id,
         param_env: tcx.param_env(def_id.to_def_id()),
         depth: 0,
     };
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index bcda26c4cc8..a5dcfab9be8 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -164,7 +164,6 @@ fn get_impl_substs(
     let infcx = &tcx.infer_ctxt().build();
     let ocx = ObligationCtxt::new(infcx);
     let param_env = tcx.param_env(impl1_def_id);
-    let impl1_hir_id = tcx.hir().local_def_id_to_hir_id(impl1_def_id);
 
     let assumed_wf_types =
         ocx.assumed_wf_types(param_env, tcx.def_span(impl1_def_id), impl1_def_id);
@@ -179,7 +178,7 @@ fn get_impl_substs(
         return None;
     }
 
-    let implied_bounds = infcx.implied_bounds_tys(param_env, impl1_hir_id, assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, impl1_def_id, assumed_wf_types);
     let outlives_env = OutlivesEnvironment::with_bounds(param_env, Some(infcx), implied_bounds);
     let _ =
         infcx.err_ctxt().check_region_obligations_and_report_errors(impl1_def_id, &outlives_env);
@@ -372,15 +371,9 @@ fn check_predicates<'tcx>(
     // Include the well-formed predicates of the type parameters of the impl.
     for arg in tcx.impl_trait_ref(impl1_def_id).unwrap().subst_identity().substs {
         let infcx = &tcx.infer_ctxt().build();
-        let obligations = wf::obligations(
-            infcx,
-            tcx.param_env(impl1_def_id),
-            tcx.hir().local_def_id_to_hir_id(impl1_def_id),
-            0,
-            arg,
-            span,
-        )
-        .unwrap();
+        let obligations =
+            wf::obligations(infcx, tcx.param_env(impl1_def_id), impl1_def_id, 0, arg, span)
+                .unwrap();
 
         assert!(!obligations.needs_infer());
         impl2_predicates.extend(
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 02548ae893f..c2fa46e563e 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -100,14 +100,14 @@ mod variance;
 
 use rustc_errors::{struct_span_err, ErrorGuaranteed};
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
-use rustc_hir::{Node, CRATE_HIR_ID};
+use rustc_hir::Node;
 use rustc_infer::infer::{InferOk, TyCtxtInferExt};
 use rustc_middle::middle;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::util;
 use rustc_session::{config::EntryFnType, parse::feature_err};
+use rustc_span::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_span::{symbol::sym, Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
@@ -182,19 +182,18 @@ fn require_same_types<'tcx>(
 }
 
 fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
-    let main_fnsig = tcx.fn_sig(main_def_id);
+    let main_fnsig = tcx.fn_sig(main_def_id).subst_identity();
     let main_span = tcx.def_span(main_def_id);
 
-    fn main_fn_diagnostics_hir_id(tcx: TyCtxt<'_>, def_id: DefId, sp: Span) -> hir::HirId {
+    fn main_fn_diagnostics_def_id(tcx: TyCtxt<'_>, def_id: DefId, sp: Span) -> LocalDefId {
         if let Some(local_def_id) = def_id.as_local() {
-            let hir_id = tcx.hir().local_def_id_to_hir_id(local_def_id);
             let hir_type = tcx.type_of(local_def_id);
             if !matches!(hir_type.kind(), ty::FnDef(..)) {
                 span_bug!(sp, "main has a non-function type: found `{}`", hir_type);
             }
-            hir_id
+            local_def_id
         } else {
-            CRATE_HIR_ID
+            CRATE_DEF_ID
         }
     }
 
@@ -251,7 +250,7 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
     }
 
     let mut error = false;
-    let main_diagnostics_hir_id = main_fn_diagnostics_hir_id(tcx, main_def_id, main_span);
+    let main_diagnostics_def_id = main_fn_diagnostics_def_id(tcx, main_def_id, main_span);
     let main_fn_generics = tcx.generics_of(main_def_id);
     let main_fn_predicates = tcx.predicates_of(main_def_id);
     if main_fn_generics.count() != 0 || !main_fnsig.bound_vars().is_empty() {
@@ -326,7 +325,7 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
         let param_env = ty::ParamEnv::empty();
         let cause = traits::ObligationCause::new(
             return_ty_span,
-            main_diagnostics_hir_id,
+            main_diagnostics_def_id,
             ObligationCauseCode::MainFunctionType,
         );
         let ocx = traits::ObligationCtxt::new(&infcx);
@@ -356,7 +355,7 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
         tcx,
         &ObligationCause::new(
             main_span,
-            main_diagnostics_hir_id,
+            main_diagnostics_def_id,
             ObligationCauseCode::MainFunctionType,
         ),
         se_ty,
@@ -444,9 +443,13 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: DefId) {
 
             require_same_types(
                 tcx,
-                &ObligationCause::new(start_span, start_id, ObligationCauseCode::StartFunctionType),
+                &ObligationCause::new(
+                    start_span,
+                    start_def_id,
+                    ObligationCauseCode::StartFunctionType,
+                ),
                 se_ty,
-                tcx.mk_fn_ptr(tcx.fn_sig(start_def_id)),
+                tcx.mk_fn_ptr(tcx.fn_sig(start_def_id).subst_identity()),
             );
         }
         _ => {
diff --git a/compiler/rustc_hir_analysis/src/variance/constraints.rs b/compiler/rustc_hir_analysis/src/variance/constraints.rs
index 5e4d82b6fd5..165782f209a 100644
--- a/compiler/rustc_hir_analysis/src/variance/constraints.rs
+++ b/compiler/rustc_hir_analysis/src/variance/constraints.rs
@@ -119,7 +119,11 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
             }
 
             ty::FnDef(..) => {
-                self.add_constraints_from_sig(current_item, tcx.fn_sig(def_id), self.covariant);
+                self.add_constraints_from_sig(
+                    current_item,
+                    tcx.fn_sig(def_id).subst_identity(),
+                    self.covariant,
+                );
             }
 
             ty::Error(_) => {}
@@ -221,8 +225,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
             }
 
             ty::Ref(region, ty, mutbl) => {
-                let contra = self.contravariant(variance);
-                self.add_constraints_from_region(current, region, contra);
+                self.add_constraints_from_region(current, region, variance);
                 self.add_constraints_from_mt(current, &ty::TypeAndMut { ty, mutbl }, variance);
             }
 
@@ -254,9 +257,8 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
             }
 
             ty::Dynamic(data, r, _) => {
-                // The type `Foo<T+'a>` is contravariant w/r/t `'a`:
-                let contra = self.contravariant(variance);
-                self.add_constraints_from_region(current, r, contra);
+                // The type `dyn Trait<T> +'a` is covariant w/r/t `'a`:
+                self.add_constraints_from_region(current, r, variance);
 
                 if let Some(poly_trait_ref) = data.principal() {
                     self.add_constraints_from_invariant_substs(
@@ -291,12 +293,12 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
                 // types, where we use Error as the Self type
             }
 
-            ty::Placeholder(..) | ty::GeneratorWitness(..) | ty::Bound(..) | ty::Infer(..) => {
-                bug!(
-                    "unexpected type encountered in \
-                      variance inference: {}",
-                    ty
-                );
+            ty::Placeholder(..)
+            | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
+            | ty::Bound(..)
+            | ty::Infer(..) => {
+                bug!("unexpected type encountered in variance inference: {}", ty);
             }
         }
     }
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index b6f19d3cc68..88fb2653586 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -188,8 +188,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let hir = self.tcx.hir();
 
         // First, check that we're actually in the tail of a function.
-        let hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Block(block, _), .. }) =
-            hir.get(self.body_id) else { return; };
+        let Some(body_id) = hir.maybe_body_owned_by(self.body_id) else { return; };
+        let body = hir.body(body_id);
+        let hir::ExprKind::Block(block, _) = body.value.kind else { return; };
         let Some(hir::Stmt { kind: hir::StmtKind::Semi(last_expr), .. })
             = block.innermost_block().stmts.last() else {  return; };
         if last_expr.hir_id != expr.hir_id {
@@ -198,7 +199,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Next, make sure that we have no type expectation.
         let Some(ret) = hir
-            .find_by_def_id(self.body_id.owner.def_id)
+            .find_by_def_id(self.body_id)
             .and_then(|owner| owner.fn_decl())
             .map(|decl| decl.output.span()) else { return; };
         let Expectation::IsLast(stmt) = expectation else {
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index b617821fbd6..c220956a201 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -367,7 +367,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> Ty<'tcx> {
         let (fn_sig, def_id) = match *callee_ty.kind() {
             ty::FnDef(def_id, subst) => {
-                let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, subst);
+                let fn_sig = self.tcx.fn_sig(def_id).subst(self.tcx, subst);
 
                 // Unit testing: function items annotated with
                 // `#[rustc_evaluate_where_clauses]` trigger special output
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index 712f9b87aed..8e21c084841 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -130,6 +130,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             | ty::Float(_)
             | ty::Array(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::RawPtr(_)
             | ty::Ref(..)
             | ty::FnDef(..)
diff --git a/compiler/rustc_hir_typeck/src/check.rs b/compiler/rustc_hir_typeck/src/check.rs
index 57feefbcab6..1c70c1b71e7 100644
--- a/compiler/rustc_hir_typeck/src/check.rs
+++ b/compiler/rustc_hir_typeck/src/check.rs
@@ -43,7 +43,7 @@ pub(super) fn check_fn<'a, 'tcx>(
     let ret_ty =
         fcx.register_infer_ok_obligations(fcx.infcx.replace_opaque_types_with_inference_vars(
             declared_ret_ty,
-            body.value.hir_id,
+            fn_def_id,
             decl.output.span(),
             fcx.param_env,
         ));
@@ -130,7 +130,12 @@ pub(super) fn check_fn<'a, 'tcx>(
     let gen_ty = if let (Some(_), Some(gen_kind)) = (can_be_generator, body.generator_kind) {
         let interior = fcx
             .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::MiscVariable, span });
-        fcx.deferred_generator_interiors.borrow_mut().push((body.id(), interior, gen_kind));
+        fcx.deferred_generator_interiors.borrow_mut().push((
+            fn_def_id,
+            body.id(),
+            interior,
+            gen_kind,
+        ));
 
         let (resume_ty, yield_ty) = fcx.resume_yield_tys.unwrap();
         Some(GeneratorTypes {
@@ -167,12 +172,12 @@ pub(super) fn check_fn<'a, 'tcx>(
 
     // Check that a function marked as `#[panic_handler]` has signature `fn(&PanicInfo) -> !`
     if let Some(panic_impl_did) = tcx.lang_items().panic_impl()
-        && panic_impl_did == hir.local_def_id(fn_id).to_def_id()
+        && panic_impl_did == fn_def_id.to_def_id()
     {
         check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig, decl, declared_ret_ty);
     }
 
-    if let Some(lang_start_defid) = tcx.lang_items().start_fn() && lang_start_defid == hir.local_def_id(fn_id).to_def_id() {
+    if let Some(lang_start_defid) = tcx.lang_items().start_fn() && lang_start_defid == fn_def_id.to_def_id() {
         check_lang_start_fn(tcx, fn_sig, decl, fn_def_id);
     }
 
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index 12a2abfa76a..329b69eff54 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -4,7 +4,6 @@ use super::{check_fn, Expectation, FnCtxt, GeneratorTypes};
 
 use hir::def::DefKind;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir_analysis::astconv::AstConv;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
@@ -14,6 +13,7 @@ use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, Ty, TypeSuperVisitable, TypeVisitor};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
@@ -80,7 +80,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         debug!(?bound_sig, ?liberated_sig);
 
-        let mut fcx = FnCtxt::new(self, self.param_env.without_const(), body.value.hir_id);
+        let mut fcx = FnCtxt::new(self, self.param_env.without_const(), closure.def_id);
         let generator_types = check_fn(
             &mut fcx,
             liberated_sig,
@@ -620,8 +620,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // function.
                 Some(hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Fn)) => {
                     debug!("closure is async fn body");
-                    self.deduce_future_output_from_obligations(expr_def_id, body.id().hir_id)
-                        .unwrap_or_else(|| {
+                    let def_id = self.tcx.hir().body_owner_def_id(body.id());
+                    self.deduce_future_output_from_obligations(expr_def_id, def_id).unwrap_or_else(
+                        || {
                             // AFAIK, deducing the future output
                             // always succeeds *except* in error cases
                             // like #65159. I'd like to return Error
@@ -630,7 +631,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             // *have* reported an
                             // error. --nikomatsakis
                             astconv.ty_infer(None, decl.output.span())
-                        })
+                        },
+                    )
                 }
 
                 _ => astconv.ty_infer(None, decl.output.span()),
@@ -665,7 +667,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     fn deduce_future_output_from_obligations(
         &self,
         expr_def_id: LocalDefId,
-        body_id: hir::HirId,
+        body_def_id: LocalDefId,
     ) -> Option<Ty<'tcx>> {
         let ret_coercion = self.ret_coercion.as_ref().unwrap_or_else(|| {
             span_bug!(self.tcx.def_span(expr_def_id), "async fn generator outside of a fn")
@@ -725,7 +727,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let InferOk { value: output_ty, obligations } = self
             .replace_opaque_types_with_inference_vars(
                 output_ty,
-                body_id,
+                body_def_id,
                 self.tcx.def_span(expr_def_id),
                 self.param_env,
             );
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index bbf7b81a2cc..ade9c037c51 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1613,12 +1613,14 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 if visitor.ret_exprs.len() > 0 && let Some(expr) = expression {
                     self.note_unreachable_loop_return(&mut err, &expr, &visitor.ret_exprs);
                 }
+
                 let reported = err.emit_unless(unsized_return);
 
                 self.final_ty = Some(fcx.tcx.ty_error_with_guaranteed(reported));
             }
         }
     }
+
     fn note_unreachable_loop_return(
         &self,
         err: &mut Diagnostic,
@@ -1821,7 +1823,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                         .trait_ref()
                         .and_then(|t| t.trait_def_id())
                         .map_or(false, |def_id| {
-                            fcx.tcx.object_safety_violations(def_id).is_empty()
+                            fcx.tcx.check_is_object_safe(def_id)
                         })
                 })
             }
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index bd1626dff79..19b8fb96cde 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -59,9 +59,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             || self.suggest_copied_or_cloned(err, expr, expr_ty, expected)
             || self.suggest_clone_for_ref(err, expr, expr_ty, expected)
             || self.suggest_into(err, expr, expr_ty, expected)
-            || self.suggest_floating_point_literal(err, expr, expected);
+            || self.suggest_floating_point_literal(err, expr, expected)
+            || self.note_result_coercion(err, expr, expected, expr_ty);
         if !suggested {
-            self.point_at_expr_source_of_inferred_type(err, expr, expr_ty, expected);
+            self.point_at_expr_source_of_inferred_type(err, expr, expr_ty, expected, expr.span);
         }
     }
 
@@ -81,7 +82,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.annotate_expected_due_to_let_ty(err, expr, error);
         self.emit_type_mismatch_suggestions(err, expr, expr_ty, expected, expected_ty_expr, error);
         self.note_type_is_not_clone(err, expected, expr_ty, expr);
-        self.note_need_for_fn_pointer(err, expected, expr_ty);
         self.note_internal_mutation_in_method(err, expr, expected, expr_ty);
         self.check_for_range_as_method_call(err, expr, expr_ty, expected);
         self.check_for_binding_assigned_block_without_tail_expression(err, expr, expr_ty, expected);
@@ -222,6 +222,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expr: &hir::Expr<'_>,
         found: Ty<'tcx>,
         expected: Ty<'tcx>,
+        mismatch_span: Span,
     ) -> bool {
         let map = self.tcx.hir();
 
@@ -270,7 +271,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             lt_op: |_| self.tcx.lifetimes.re_erased,
             ct_op: |c| c,
             ty_op: |t| match *t.kind() {
-                ty::Infer(ty::TyVar(vid)) => self.tcx.mk_ty_infer(ty::TyVar(self.root_var(vid))),
+                ty::Infer(ty::TyVar(_)) => self.tcx.mk_ty_var(ty::TyVid::from_u32(0)),
                 ty::Infer(ty::IntVar(_)) => {
                     self.tcx.mk_ty_infer(ty::IntVar(ty::IntVid { index: 0 }))
                 }
@@ -281,7 +282,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             },
         };
         let mut prev = eraser.fold_ty(ty);
-        let mut prev_span = None;
+        let mut prev_span: Option<Span> = None;
 
         for binding in expr_finder.uses {
             // In every expression where the binding is referenced, we will look at that
@@ -298,7 +299,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             {
                 // We special case methods, because they can influence inference through the
                 // call's arguments and we can provide a more explicit span.
-                let sig = self.tcx.fn_sig(def_id);
+                let sig = self.tcx.fn_sig(def_id).subst_identity();
                 let def_self_ty = sig.input(0).skip_binder();
                 let rcvr_ty = self.node_ty(rcvr.hir_id);
                 // Get the evaluated type *after* calling the method call, so that the influence
@@ -333,13 +334,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             // inferred in this method call.
                             let arg = &args[i];
                             let arg_ty = self.node_ty(arg.hir_id);
-                            err.span_label(
-                                arg.span,
-                                &format!(
-                                    "this is of type `{arg_ty}`, which causes `{ident}` to be \
-                                     inferred as `{ty}`",
-                                ),
-                            );
+                            if !arg.span.overlaps(mismatch_span) {
+                                err.span_label(
+                                    arg.span,
+                                    &format!(
+                                        "this is of type `{arg_ty}`, which causes `{ident}` to be \
+                                        inferred as `{ty}`",
+                                    ),
+                                );
+                            }
                             param_args.insert(param_ty, (arg, arg_ty));
                         }
                     }
@@ -382,12 +385,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     && self.can_eq(self.param_env, ty, found).is_ok()
                 {
                     // We only point at the first place where the found type was inferred.
+                    if !segment.ident.span.overlaps(mismatch_span) {
                     err.span_label(
                         segment.ident.span,
                         with_forced_trimmed_paths!(format!(
                             "here the type of `{ident}` is inferred to be `{ty}`",
                         )),
-                    );
+                    );}
                     break;
                 } else if !param_args.is_empty() {
                     break;
@@ -406,12 +410,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // We use the *previous* span because if the type is known *here* it means
                     // it was *evaluated earlier*. We don't do this for method calls because we
                     // evaluate the method's self type eagerly, but not in any other case.
-                    err.span_label(
-                        span,
-                        with_forced_trimmed_paths!(format!(
-                            "here the type of `{ident}` is inferred to be `{ty}`",
-                        )),
-                    );
+                    if !span.overlaps(mismatch_span) {
+                        err.span_label(
+                            span,
+                            with_forced_trimmed_paths!(format!(
+                                "here the type of `{ident}` is inferred to be `{ty}`",
+                            )),
+                        );
+                    }
                     break;
                 }
                 prev = ty;
@@ -597,6 +603,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let substs = ty::InternalSubsts::for_item(self.tcx, m.def_id, |param, _| {
                     self.var_for_def(deref.span, param)
                 });
+                let mutability =
+                    match self.tcx.fn_sig(m.def_id).skip_binder().input(0).skip_binder().kind() {
+                        ty::Ref(_, _, hir::Mutability::Mut) => "&mut ",
+                        ty::Ref(_, _, _) => "&",
+                        _ => "",
+                    };
                 vec![
                     (
                         deref.span.until(base.span),
@@ -605,11 +617,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             with_no_trimmed_paths!(
                                 self.tcx.def_path_str_with_substs(m.def_id, substs,)
                             ),
-                            match self.tcx.fn_sig(m.def_id).input(0).skip_binder().kind() {
-                                ty::Ref(_, _, hir::Mutability::Mut) => "&mut ",
-                                ty::Ref(_, _, _) => "&",
-                                _ => "",
-                            },
+                            mutability,
                         ),
                     ),
                     match &args[..] {
@@ -697,6 +705,56 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
     }
 
+    pub(crate) fn note_result_coercion(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'tcx>,
+        expected: Ty<'tcx>,
+        found: Ty<'tcx>,
+    ) -> bool {
+        let ty::Adt(e, substs_e) = expected.kind() else { return false; };
+        let ty::Adt(f, substs_f) = found.kind() else { return false; };
+        if e.did() != f.did() {
+            return false;
+        }
+        if Some(e.did()) != self.tcx.get_diagnostic_item(sym::Result) {
+            return false;
+        }
+        let map = self.tcx.hir();
+        if let Some(hir::Node::Expr(expr)) = map.find_parent(expr.hir_id)
+            && let hir::ExprKind::Ret(_) = expr.kind
+        {
+            // `return foo;`
+        } else if map.get_return_block(expr.hir_id).is_some() {
+            // Function's tail expression.
+        } else {
+            return false;
+        }
+        let e = substs_e.type_at(1);
+        let f = substs_f.type_at(1);
+        if self
+            .infcx
+            .type_implements_trait(
+                self.tcx.get_diagnostic_item(sym::Into).unwrap(),
+                [f, e],
+                self.param_env,
+            )
+            .must_apply_modulo_regions()
+        {
+            err.multipart_suggestion(
+                "use `?` to coerce and return an appropriate `Err`, and wrap the resulting value \
+                 in `Ok` so the expression remains of type `Result`",
+                vec![
+                    (expr.span.shrink_to_lo(), "Ok(".to_string()),
+                    (expr.span.shrink_to_hi(), "?)".to_string()),
+                ],
+                Applicability::MaybeIncorrect,
+            );
+            return true;
+        }
+        false
+    }
+
     /// If the expected type is an enum (Issue #55250) with any variants whose
     /// sole field is of the found type, suggest such variants. (Issue #42764)
     fn suggest_compatible_variants(
@@ -980,7 +1038,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         match method.kind {
             ty::AssocKind::Fn => {
                 method.fn_has_self_parameter
-                    && self.tcx.fn_sig(method.def_id).inputs().skip_binder().len() == 1
+                    && self.tcx.fn_sig(method.def_id).skip_binder().inputs().skip_binder().len()
+                        == 1
             }
             _ => false,
         }
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index bc7474cdfcf..74913bac724 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -542,7 +542,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         if let ty::FnDef(did, ..) = *ty.kind() {
             let fn_sig = ty.fn_sig(tcx);
-            if tcx.fn_sig(did).abi() == RustIntrinsic && tcx.item_name(did) == sym::transmute {
+            if tcx.fn_sig(did).skip_binder().abi() == RustIntrinsic
+                && tcx.item_name(did) == sym::transmute
+            {
                 let from = fn_sig.inputs().skip_binder()[0];
                 let to = fn_sig.output().skip_binder();
                 // We defer the transmute to the end of typeck, once all inference vars have
@@ -852,7 +854,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Point any obligations that were registered due to opaque type
             // inference at the return expression.
             self.select_obligations_where_possible(|errors| {
-                self.point_at_return_for_opaque_ty_error(errors, span, return_expr_ty);
+                self.point_at_return_for_opaque_ty_error(errors, span, return_expr_ty, return_expr.span);
             });
         }
     }
@@ -862,9 +864,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         errors: &mut Vec<traits::FulfillmentError<'tcx>>,
         span: Span,
         return_expr_ty: Ty<'tcx>,
+        return_span: Span,
     ) {
         // Don't point at the whole block if it's empty
-        if span == self.tcx.hir().span(self.body_id) {
+        if span == return_span {
             return;
         }
         for err in errors {
@@ -1374,7 +1377,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let body = self.tcx.hir().body(anon_const.body);
 
         // Create a new function context.
-        let fcx = FnCtxt::new(self, self.param_env.with_const(), body.value.hir_id);
+        let def_id = anon_const.def_id;
+        let fcx = FnCtxt::new(self, self.param_env.with_const(), def_id);
         crate::GatherLocalsVisitor::new(&fcx).visit_body(body);
 
         let ty = fcx.check_expr_with_expectation(&body.value, expected);
@@ -2151,13 +2155,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         variant: &'tcx ty::VariantDef,
         access_span: Span,
     ) -> Vec<Symbol> {
+        let body_owner_hir_id = self.tcx.hir().local_def_id_to_hir_id(self.body_id);
         variant
             .fields
             .iter()
             .filter(|field| {
                 let def_scope = self
                     .tcx
-                    .adjust_ident_and_get_scope(field.ident(self.tcx), variant.def_id, self.body_id)
+                    .adjust_ident_and_get_scope(
+                        field.ident(self.tcx),
+                        variant.def_id,
+                        body_owner_hir_id,
+                    )
                     .1;
                 field.vis.is_accessible_from(def_scope, self.tcx)
                     && !matches!(
@@ -2199,8 +2208,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             match deref_base_ty.kind() {
                 ty::Adt(base_def, substs) if !base_def.is_enum() => {
                     debug!("struct named {:?}", deref_base_ty);
+                    let body_hir_id = self.tcx.hir().local_def_id_to_hir_id(self.body_id);
                     let (ident, def_scope) =
-                        self.tcx.adjust_ident_and_get_scope(field, base_def.did(), self.body_id);
+                        self.tcx.adjust_ident_and_get_scope(field, base_def.did(), body_hir_id);
                     let fields = &base_def.non_enum_variant().fields;
                     if let Some(index) = fields
                         .iter()
@@ -2538,7 +2548,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     fn point_at_param_definition(&self, err: &mut Diagnostic, param: ty::ParamTy) {
-        let generics = self.tcx.generics_of(self.body_id.owner.to_def_id());
+        let generics = self.tcx.generics_of(self.body_id);
         let generic_param = generics.type_param(&param, self.tcx);
         if let ty::GenericParamDefKind::Type { synthetic: true, .. } = generic_param.kind {
             return;
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 6ed8adb4742..a355a54d695 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -517,16 +517,72 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     pub(in super::super) fn resolve_generator_interiors(&self, def_id: DefId) {
+        if self.tcx.sess.opts.unstable_opts.drop_tracking_mir {
+            self.save_generator_interior_predicates(def_id);
+            return;
+        }
+
+        self.select_obligations_where_possible(|_| {});
+
         let mut generators = self.deferred_generator_interiors.borrow_mut();
-        for (body_id, interior, kind) in generators.drain(..) {
-            self.select_obligations_where_possible(|_| {});
+        for (_, body_id, interior, kind) in generators.drain(..) {
             crate::generator_interior::resolve_interior(self, def_id, body_id, interior, kind);
+            self.select_obligations_where_possible(|_| {});
+        }
+    }
+
+    /// Unify the inference variables corresponding to generator witnesses, and save all the
+    /// predicates that were stalled on those inference variables.
+    ///
+    /// This process allows to conservatively save all predicates that do depend on the generator
+    /// interior types, for later processing by `check_generator_obligations`.
+    ///
+    /// We must not attempt to select obligations after this method has run, or risk query cycle
+    /// ICE.
+    #[instrument(level = "debug", skip(self))]
+    fn save_generator_interior_predicates(&self, def_id: DefId) {
+        // Try selecting all obligations that are not blocked on inference variables.
+        // Once we start unifying generator witnesses, trying to select obligations on them will
+        // trigger query cycle ICEs, as doing so requires MIR.
+        self.select_obligations_where_possible(|_| {});
+
+        let generators = std::mem::take(&mut *self.deferred_generator_interiors.borrow_mut());
+        debug!(?generators);
+
+        for &(expr_def_id, body_id, interior, _) in generators.iter() {
+            debug!(?expr_def_id);
+
+            // Create the `GeneratorWitness` type that we will unify with `interior`.
+            let substs = ty::InternalSubsts::identity_for_item(
+                self.tcx,
+                self.tcx.typeck_root_def_id(expr_def_id.to_def_id()),
+            );
+            let witness = self.tcx.mk_generator_witness_mir(expr_def_id.to_def_id(), substs);
+
+            // Unify `interior` with `witness` and collect all the resulting obligations.
+            let span = self.tcx.hir().body(body_id).value.span;
+            let ok = self
+                .at(&self.misc(span), self.param_env)
+                .eq(interior, witness)
+                .expect("Failed to unify generator interior type");
+            let mut obligations = ok.obligations;
+
+            // Also collect the obligations that were unstalled by this unification.
+            obligations
+                .extend(self.fulfillment_cx.borrow_mut().drain_unstalled_obligations(&self.infcx));
+
+            let obligations = obligations.into_iter().map(|o| (o.predicate, o.cause)).collect();
+            debug!(?obligations);
+            self.typeck_results
+                .borrow_mut()
+                .generator_interior_predicates
+                .insert(expr_def_id, obligations);
         }
     }
 
     #[instrument(skip(self), level = "debug")]
-    pub(in super::super) fn select_all_obligations_or_error(&self) {
-        let mut errors = self.fulfillment_cx.borrow_mut().select_all_or_error(&self);
+    pub(in super::super) fn report_ambiguity_errors(&self) {
+        let mut errors = self.fulfillment_cx.borrow_mut().collect_remaining_errors();
 
         if !errors.is_empty() {
             self.adjust_fulfillment_errors_for_expr_obligation(&mut errors);
@@ -926,43 +982,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub(in super::super) fn note_need_for_fn_pointer(
-        &self,
-        err: &mut Diagnostic,
-        expected: Ty<'tcx>,
-        found: Ty<'tcx>,
-    ) {
-        let (sig, did, substs) = match (&expected.kind(), &found.kind()) {
-            (ty::FnDef(did1, substs1), ty::FnDef(did2, substs2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did1).subst(self.tcx, substs1);
-                let sig2 = self.tcx.bound_fn_sig(*did2).subst(self.tcx, substs2);
-                if sig1 != sig2 {
-                    return;
-                }
-                err.note(
-                    "different `fn` items always have unique types, even if their signatures are \
-                     the same",
-                );
-                (sig1, *did1, substs1)
-            }
-            (ty::FnDef(did, substs), ty::FnPtr(sig2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did).subst(self.tcx, substs);
-                if sig1 != *sig2 {
-                    return;
-                }
-                (sig1, *did, substs)
-            }
-            _ => return,
-        };
-        err.help(&format!("change the expected type to be function pointer `{}`", sig));
-        err.help(&format!(
-            "if the expected type is due to type inference, cast the expected `fn` to a function \
-             pointer: `{} as {}`",
-            self.tcx.def_path_str_with_substs(did, substs),
-            sig
-        ));
-    }
-
     // Instantiates the given path, which must refer to an item with the given
     // number of type parameters and type.
     #[instrument(skip(self, span), level = "debug")]
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index c9609e69439..47ef106e750 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -79,7 +79,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             };
             InlineAsmCtxt::new_in_fn(self.tcx, self.param_env, get_operand_ty)
-                .check_asm(asm, self.tcx.hir().local_def_id_to_hir_id(enclosing_id));
+                .check_asm(asm, enclosing_id);
         }
     }
 
@@ -808,7 +808,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     kind: TypeVariableOriginKind::MiscVariable,
                     span: full_call_span,
                 });
-                self.point_at_expr_source_of_inferred_type(&mut err, rcvr, expected, callee_ty);
+                self.point_at_expr_source_of_inferred_type(
+                    &mut err,
+                    rcvr,
+                    expected,
+                    callee_ty,
+                    provided_arg_span,
+                );
             }
             // Call out where the function is defined
             self.label_fn_like(
@@ -2126,7 +2132,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             match *callee_ty.kind() {
                 ty::Param(param) => {
                     let param =
-                        self.tcx.generics_of(self.body_id.owner).type_param(&param, self.tcx);
+                        self.tcx.generics_of(self.body_id).type_param(&param, self.tcx);
                     if param.kind.is_synthetic() {
                         // if it's `impl Fn() -> ..` then just fall down to the def-id based logic
                         def_id = param.def_id;
@@ -2135,7 +2141,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // and point at that.
                         let instantiated = self
                             .tcx
-                            .explicit_predicates_of(self.body_id.owner)
+                            .explicit_predicates_of(self.body_id)
                             .instantiate_identity(self.tcx);
                         // FIXME(compiler-errors): This could be problematic if something has two
                         // fn-like predicates with different args, but callable types really never
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index 428fde642bc..4940015ddd5 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -10,7 +10,7 @@ pub use suggestions::*;
 use crate::coercion::DynamicCoerceMany;
 use crate::{Diverges, EnclosingBreakables, Inherited};
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir_analysis::astconv::AstConv;
 use rustc_infer::infer;
 use rustc_infer::infer::error_reporting::TypeErrCtxt;
@@ -38,7 +38,7 @@ use std::ops::Deref;
 /// [`ItemCtxt`]: rustc_hir_analysis::collect::ItemCtxt
 /// [`InferCtxt`]: infer::InferCtxt
 pub struct FnCtxt<'a, 'tcx> {
-    pub(super) body_id: hir::HirId,
+    pub(super) body_id: LocalDefId,
 
     /// The parameter environment used for proving trait obligations
     /// in this function. This can change when we descend into
@@ -117,7 +117,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub fn new(
         inh: &'a Inherited<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     ) -> FnCtxt<'a, 'tcx> {
         FnCtxt {
             body_id,
@@ -204,7 +204,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
     }
 
     fn item_def_id(&self) -> DefId {
-        self.body_id.owner.to_def_id()
+        self.body_id.to_def_id()
     }
 
     fn get_type_parameter_bounds(
@@ -324,6 +324,10 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
         let ty = if !ty.has_escaping_bound_vars() { self.normalize(span, ty) } else { ty };
         self.write_ty(hir_id, ty)
     }
+
+    fn infcx(&self) -> Option<&infer::InferCtxt<'tcx>> {
+        Some(&self.infcx)
+    }
 }
 
 /// Represents a user-provided type in the raw form (never normalized).
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 4d673ac9147..6046e55c65c 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -31,7 +31,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.typeck_results
             .borrow()
             .liberated_fn_sigs()
-            .get(self.tcx.hir().parent_id(self.body_id))
+            .get(self.tcx.hir().local_def_id_to_hir_id(self.body_id))
             .copied()
     }
 
@@ -164,7 +164,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         ty: Ty<'tcx>,
     ) -> Option<(DefIdOrName, Ty<'tcx>, Vec<Ty<'tcx>>)> {
-        self.err_ctxt().extract_callable_info(self.body_id, self.param_env, ty)
+        let body_hir_id = self.tcx.hir().local_def_id_to_hir_id(self.body_id);
+        self.err_ctxt().extract_callable_info(body_hir_id, self.param_env, ty)
     }
 
     pub fn suggest_two_fn_call(
diff --git a/compiler/rustc_hir_typeck/src/gather_locals.rs b/compiler/rustc_hir_typeck/src/gather_locals.rs
index 15dd3412c34..38445f28440 100644
--- a/compiler/rustc_hir_typeck/src/gather_locals.rs
+++ b/compiler/rustc_hir_typeck/src/gather_locals.rs
@@ -5,6 +5,7 @@ use rustc_hir::PatKind;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::UserType;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 use rustc_trait_selection::traits;
 
@@ -156,7 +157,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
         _: &'tcx hir::FnDecl<'tcx>,
         _: hir::BodyId,
         _: Span,
-        _: hir::HirId,
+        _: LocalDefId,
     ) {
     }
 }
diff --git a/compiler/rustc_hir_typeck/src/inherited.rs b/compiler/rustc_hir_typeck/src/inherited.rs
index ba34f299453..87e54025330 100644
--- a/compiler/rustc_hir_typeck/src/inherited.rs
+++ b/compiler/rustc_hir_typeck/src/inherited.rs
@@ -56,7 +56,7 @@ pub struct Inherited<'tcx> {
     pub(super) deferred_asm_checks: RefCell<Vec<(&'tcx hir::InlineAsm<'tcx>, hir::HirId)>>,
 
     pub(super) deferred_generator_interiors:
-        RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>,
+        RefCell<Vec<(LocalDefId, hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>,
 
     pub(super) body_id: Option<hir::BodyId>,
 
diff --git a/compiler/rustc_hir_typeck/src/intrinsicck.rs b/compiler/rustc_hir_typeck/src/intrinsicck.rs
index 3c873024c92..2c76582f2ec 100644
--- a/compiler/rustc_hir_typeck/src/intrinsicck.rs
+++ b/compiler/rustc_hir_typeck/src/intrinsicck.rs
@@ -38,6 +38,7 @@ fn unpack_option_like<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub fn check_transmute(&self, from: Ty<'tcx>, to: Ty<'tcx>, hir_id: HirId) {
         let tcx = self.tcx;
+        let dl = &tcx.data_layout;
         let span = tcx.hir().span(hir_id);
         let normalize = |ty| {
             let ty = self.resolve_vars_if_possible(ty);
@@ -69,7 +70,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Special-case transmuting from `typeof(function)` and
             // `Option<typeof(function)>` to present a clearer error.
             let from = unpack_option_like(tcx, from);
-            if let (&ty::FnDef(..), SizeSkeleton::Known(size_to)) = (from.kind(), sk_to) && size_to == Pointer.size(&tcx) {
+            if let (&ty::FnDef(..), SizeSkeleton::Known(size_to)) = (from.kind(), sk_to) && size_to == Pointer(dl.instruction_address_space).size(&tcx) {
                 struct_span_err!(tcx.sess, span, E0591, "can't transmute zero-sized type")
                     .note(&format!("source type: {from}"))
                     .note(&format!("target type: {to}"))
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 7ddf9eaa4d8..323bacf70ab 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -201,13 +201,13 @@ fn typeck_with_fallback<'tcx>(
 
     let typeck_results = Inherited::build(tcx, def_id).enter(|inh| {
         let param_env = tcx.param_env(def_id);
-        let mut fcx = FnCtxt::new(&inh, param_env, body.value.hir_id);
+        let mut fcx = FnCtxt::new(&inh, param_env, def_id);
 
         if let Some(hir::FnSig { header, decl, .. }) = fn_sig {
             let fn_sig = if rustc_hir_analysis::collect::get_infer_ret_ty(&decl.output).is_some() {
                 fcx.astconv().ty_of_fn(id, header.unsafety, header.abi, decl, None, None)
             } else {
-                tcx.fn_sig(def_id)
+                tcx.fn_sig(def_id).subst_identity()
             };
 
             check_abi(tcx, id, span, fn_sig.abi());
@@ -294,14 +294,24 @@ fn typeck_with_fallback<'tcx>(
         // Before the generator analysis, temporary scopes shall be marked to provide more
         // precise information on types to be captured.
         fcx.resolve_rvalue_scopes(def_id.to_def_id());
-        fcx.resolve_generator_interiors(def_id.to_def_id());
 
         for (ty, span, code) in fcx.deferred_sized_obligations.borrow_mut().drain(..) {
             let ty = fcx.normalize(span, ty);
             fcx.require_type_is_sized(ty, span, code);
         }
 
-        fcx.select_all_obligations_or_error();
+        fcx.select_obligations_where_possible(|_| {});
+
+        debug!(pending_obligations = ?fcx.fulfillment_cx.borrow().pending_obligations());
+
+        // This must be the last thing before `report_ambiguity_errors`.
+        fcx.resolve_generator_interiors(def_id.to_def_id());
+
+        debug!(pending_obligations = ?fcx.fulfillment_cx.borrow().pending_obligations());
+
+        if let None = fcx.infcx.tainted_by_errors() {
+            fcx.report_ambiguity_errors();
+        }
 
         if let None = fcx.infcx.tainted_by_errors() {
             fcx.check_transmutes();
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index 372ea30ebd0..65ca47bfe53 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -503,9 +503,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
 
         debug!("method_predicates after subst = {:?}", method_predicates);
 
-        let sig = self.tcx.bound_fn_sig(def_id);
-
-        let sig = sig.subst(self.tcx, all_substs);
+        let sig = self.tcx.fn_sig(def_id).subst(self.tcx, all_substs);
         debug!("type scheme substituted, sig={:?}", sig);
 
         let sig = self.replace_bound_vars_with_fresh_vars(sig);
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
index 47396204b14..60d4dc326ee 100644
--- a/compiler/rustc_hir_typeck/src/method/mod.rs
+++ b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -145,7 +145,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             )
             .map(|pick| {
                 let sig = self.tcx.fn_sig(pick.item.def_id);
-                sig.inputs().skip_binder().len().saturating_sub(1)
+                sig.skip_binder().inputs().skip_binder().len().saturating_sub(1)
             })
             .unwrap_or(0);
 
@@ -399,8 +399,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // N.B., instantiate late-bound regions before normalizing the
         // function signature so that normalization does not need to deal
         // with bound regions.
-        let fn_sig = tcx.bound_fn_sig(def_id);
-        let fn_sig = fn_sig.subst(self.tcx, substs);
+        let fn_sig = tcx.fn_sig(def_id).subst(self.tcx, substs);
         let fn_sig =
             self.replace_bound_vars_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig);
 
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 9c06a22315b..9fc4c16fb07 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -508,9 +508,10 @@ fn method_autoderef_steps<'tcx>(
     let (ref infcx, goal, inference_vars) = tcx.infer_ctxt().build_with_canonical(DUMMY_SP, &goal);
     let ParamEnvAnd { param_env, value: self_ty } = goal;
 
-    let mut autoderef = Autoderef::new(infcx, param_env, hir::CRATE_HIR_ID, DUMMY_SP, self_ty)
-        .include_raw_pointers()
-        .silence_errors();
+    let mut autoderef =
+        Autoderef::new(infcx, param_env, hir::def_id::CRATE_DEF_ID, DUMMY_SP, self_ty)
+            .include_raw_pointers()
+            .silence_errors();
     let mut reached_raw_pointer = false;
     let mut steps: Vec<_> = autoderef
         .by_ref()
@@ -610,10 +611,9 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     fn push_candidate(&mut self, candidate: Candidate<'tcx>, is_inherent: bool) {
         let is_accessible = if let Some(name) = self.method_name {
             let item = candidate.item;
-            let def_scope = self
-                .tcx
-                .adjust_ident_and_get_scope(name, item.container_id(self.tcx), self.body_id)
-                .1;
+            let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.body_id);
+            let def_scope =
+                self.tcx.adjust_ident_and_get_scope(name, item.container_id(self.tcx), hir_id).1;
             item.visibility(self.tcx).is_accessible_from(def_scope, self.tcx)
         } else {
             true
@@ -921,26 +921,22 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         expected: Ty<'tcx>,
     ) -> bool {
         match method.kind {
-            ty::AssocKind::Fn => {
-                let fty = self.tcx.bound_fn_sig(method.def_id);
-                self.probe(|_| {
-                    let substs = self.fresh_substs_for_item(self.span, method.def_id);
-                    let fty = fty.subst(self.tcx, substs);
-                    let fty =
-                        self.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, fty);
-
-                    if let Some(self_ty) = self_ty {
-                        if self
-                            .at(&ObligationCause::dummy(), self.param_env)
-                            .sup(fty.inputs()[0], self_ty)
-                            .is_err()
-                        {
-                            return false;
-                        }
+            ty::AssocKind::Fn => self.probe(|_| {
+                let substs = self.fresh_substs_for_item(self.span, method.def_id);
+                let fty = self.tcx.fn_sig(method.def_id).subst(self.tcx, substs);
+                let fty = self.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, fty);
+
+                if let Some(self_ty) = self_ty {
+                    if self
+                        .at(&ObligationCause::dummy(), self.param_env)
+                        .sup(fty.inputs()[0], self_ty)
+                        .is_err()
+                    {
+                        return false;
                     }
-                    self.can_sub(self.param_env, fty.output(), expected).is_ok()
-                })
-            }
+                }
+                self.can_sub(self.param_env, fty.output(), expected).is_ok()
+            }),
             _ => false,
         }
     }
@@ -1887,7 +1883,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
     #[instrument(level = "debug", skip(self))]
     fn xform_method_sig(&self, method: DefId, substs: SubstsRef<'tcx>) -> ty::FnSig<'tcx> {
-        let fn_sig = self.tcx.bound_fn_sig(method);
+        let fn_sig = self.tcx.fn_sig(method);
         debug!(?fn_sig);
 
         assert!(!substs.has_escaping_bound_vars());
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 8c54e9bdb5f..31d55a41d8a 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -352,7 +352,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let ty_span = match rcvr_ty.kind() {
             ty::Param(param_type) => {
-                Some(param_type.span_from_generics(self.tcx, self.body_id.owner.to_def_id()))
+                Some(param_type.span_from_generics(self.tcx, self.body_id.to_def_id()))
             }
             ty::Adt(def, _) if def.did().is_local() => Some(tcx.def_span(def.did())),
             _ => None,
@@ -403,7 +403,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 args,
                 sugg_span,
             );
-
             self.note_candidates_on_method_error(
                 rcvr_ty,
                 item_name,
@@ -496,9 +495,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             ty::Param(_) => {
                                 // Account for `fn` items like in `issue-35677.rs` to
                                 // suggest restricting its type params.
-                                let parent_body =
-                                    hir.body_owner(hir::BodyId { hir_id: self.body_id });
-                                Some(hir.get(parent_body))
+                                Some(hir.get_by_def_id(self.body_id))
                             }
                             ty::Adt(def, _) => {
                                 def.did().as_local().map(|def_id| hir.get_by_def_id(def_id))
@@ -1131,6 +1128,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             ty::AssocKind::Fn => self
                                 .tcx
                                 .fn_sig(item.def_id)
+                                .subst_identity()
                                 .inputs()
                                 .skip_binder()
                                 .get(0)
@@ -1267,7 +1265,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 && let Some(assoc) = self.associated_value(*impl_did, item_name)
                 && assoc.kind == ty::AssocKind::Fn
             {
-                let sig = self.tcx.fn_sig(assoc.def_id);
+                let sig = self.tcx.fn_sig(assoc.def_id).subst_identity();
                 sig.inputs().skip_binder().get(0).and_then(|first| if first.peel_refs() == rcvr_ty.peel_refs() {
                     None
                 } else {
@@ -1343,7 +1341,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => None,
         });
         if let Some((field, field_ty)) = field_receiver {
-            let scope = tcx.parent_module(self.body_id);
+            let scope = tcx.parent_module_from_def_id(self.body_id);
             let is_accessible = field.vis.is_accessible_from(scope, tcx);
 
             if is_accessible {
@@ -1593,7 +1591,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 else { return };
 
         let map = self.infcx.tcx.hir();
-        let body = map.body(rustc_hir::BodyId { hir_id: self.body_id });
+        let body_id = self.tcx.hir().body_owned_by(self.body_id);
+        let body = map.body(body_id);
         struct LetVisitor<'a> {
             result: Option<&'a hir::Expr<'a>>,
             ident_name: Symbol,
@@ -2100,7 +2099,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // just changing the path.
                     && pick.item.fn_has_self_parameter
                     && let Some(self_ty) =
-                        self.tcx.fn_sig(pick.item.def_id).inputs().skip_binder().get(0)
+                        self.tcx.fn_sig(pick.item.def_id).subst_identity().inputs().skip_binder().get(0)
                     && self_ty.is_ref()
                 {
                     let suggested_path = match deref_ty.kind() {
@@ -2195,7 +2194,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             true
         });
 
-        let module_did = self.tcx.parent_module(self.body_id);
+        let module_did = self.tcx.parent_module_from_def_id(self.body_id);
         let (module, _, _) = self.tcx.hir().get_module(module_did);
         let span = module.spans.inject_use_span;
 
@@ -2353,7 +2352,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // implement the `AsRef` trait.
                         let skip = skippable.contains(&did)
                             || (("Pin::new" == *pre) && (sym::as_ref == item_name.name))
-                            || inputs_len.map_or(false, |inputs_len| pick.item.kind == ty::AssocKind::Fn && self.tcx.fn_sig(pick.item.def_id).skip_binder().inputs().len() != inputs_len);
+                            || inputs_len.map_or(false, |inputs_len| pick.item.kind == ty::AssocKind::Fn && self.tcx.fn_sig(pick.item.def_id).skip_binder().skip_binder().inputs().len() != inputs_len);
                         // Make sure the method is defined for the *actual* receiver: we don't
                         // want to treat `Box<Self>` as a receiver if it only works because of
                         // an autoderef to `&self`
@@ -2517,7 +2516,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             };
             // Obtain the span for `param` and use it for a structured suggestion.
             if let Some(param) = param_type {
-                let generics = self.tcx.generics_of(self.body_id.owner.to_def_id());
+                let generics = self.tcx.generics_of(self.body_id.to_def_id());
                 let type_param = generics.type_param(param, self.tcx);
                 let hir = self.tcx.hir();
                 if let Some(def_id) = type_param.def_id.as_local() {
@@ -2733,7 +2732,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // check the method arguments number
             if let Ok(pick) = probe &&
                 let fn_sig = self.tcx.fn_sig(pick.item.def_id) &&
-                let fn_args = fn_sig.skip_binder().inputs() &&
+                let fn_args = fn_sig.skip_binder().skip_binder().inputs() &&
                 fn_args.len() == args.len() + 1 {
                 err.span_suggestion_verbose(
                     method_name.span.shrink_to_hi(),
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 250f4cd3f65..0aa34f9dd70 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -40,8 +40,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         body: &'tcx hir::Body<'tcx>,
     ) -> &'tcx ty::TypeckResults<'tcx> {
-        let item_id = self.tcx.hir().body_owner(body.id());
-        let item_def_id = self.tcx.hir().local_def_id(item_id);
+        let item_def_id = self.tcx.hir().body_owner_def_id(body.id());
 
         // This attribute causes us to dump some writeback information
         // in the form of errors, which is used for unit tests.
@@ -55,7 +54,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Type only exists for constants and statics, not functions.
         match self.tcx.hir().body_owner_kind(item_def_id) {
             hir::BodyOwnerKind::Const | hir::BodyOwnerKind::Static(_) => {
-                wbcx.visit_node_id(body.value.span, item_id);
+                let item_hir_id = self.tcx.hir().local_def_id_to_hir_id(item_def_id);
+                wbcx.visit_node_id(body.value.span, item_hir_id);
             }
             hir::BodyOwnerKind::Closure | hir::BodyOwnerKind::Fn => (),
         }
@@ -545,6 +545,10 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
         self.typeck_results.generator_interior_types =
             fcx_typeck_results.generator_interior_types.clone();
+        for (&expr_def_id, predicates) in fcx_typeck_results.generator_interior_predicates.iter() {
+            let predicates = self.resolve(predicates.clone(), &self.fcx.tcx.def_span(expr_def_id));
+            self.typeck_results.generator_interior_predicates.insert(expr_def_id, predicates);
+        }
     }
 
     #[instrument(skip(self), level = "debug")]
diff --git a/compiler/rustc_incremental/src/assert_dep_graph.rs b/compiler/rustc_incremental/src/assert_dep_graph.rs
index 33a9a0cabb9..6703d53f380 100644
--- a/compiler/rustc_incremental/src/assert_dep_graph.rs
+++ b/compiler/rustc_incremental/src/assert_dep_graph.rs
@@ -38,7 +38,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::graph::implementation::{Direction, NodeIndex, INCOMING, OUTGOING};
 use rustc_graphviz as dot;
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_middle::dep_graph::{
     DepGraphQuery, DepKind, DepNode, DepNodeExt, DepNodeFilter, EdgeFilter,
@@ -74,7 +74,7 @@ pub fn assert_dep_graph(tcx: TyCtxt<'_>) {
         let (if_this_changed, then_this_would_need) = {
             let mut visitor =
                 IfThisChanged { tcx, if_this_changed: vec![], then_this_would_need: vec![] };
-            visitor.process_attrs(hir::CRATE_HIR_ID);
+            visitor.process_attrs(CRATE_DEF_ID);
             tcx.hir().visit_all_item_likes_in_crate(&mut visitor);
             (visitor.if_this_changed, visitor.then_this_would_need)
         };
@@ -119,9 +119,9 @@ impl<'tcx> IfThisChanged<'tcx> {
         value
     }
 
-    fn process_attrs(&mut self, hir_id: hir::HirId) {
-        let def_id = self.tcx.hir().local_def_id(hir_id);
+    fn process_attrs(&mut self, def_id: LocalDefId) {
         let def_path_hash = self.tcx.def_path_hash(def_id.to_def_id());
+        let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
         let attrs = self.tcx.hir().attrs(hir_id);
         for attr in attrs {
             if attr.has_name(sym::rustc_if_this_changed) {
@@ -180,22 +180,22 @@ impl<'tcx> Visitor<'tcx> for IfThisChanged<'tcx> {
     }
 
     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
-        self.process_attrs(item.hir_id());
+        self.process_attrs(item.owner_id.def_id);
         intravisit::walk_item(self, item);
     }
 
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
-        self.process_attrs(trait_item.hir_id());
+        self.process_attrs(trait_item.owner_id.def_id);
         intravisit::walk_trait_item(self, trait_item);
     }
 
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
-        self.process_attrs(impl_item.hir_id());
+        self.process_attrs(impl_item.owner_id.def_id);
         intravisit::walk_impl_item(self, impl_item);
     }
 
     fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
-        self.process_attrs(s.hir_id);
+        self.process_attrs(s.def_id);
         intravisit::walk_field_def(self, s);
     }
 }
diff --git a/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs b/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
index 091635e6c73..87c6dfad5fa 100644
--- a/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
+++ b/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
@@ -435,6 +435,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
             ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Bool
             | ty::Char
             | ty::Int(..)
diff --git a/compiler/rustc_infer/src/infer/canonical/mod.rs b/compiler/rustc_infer/src/infer/canonical/mod.rs
index e59715b706b..f7e3e4a1cc0 100644
--- a/compiler/rustc_infer/src/infer/canonical/mod.rs
+++ b/compiler/rustc_infer/src/infer/canonical/mod.rs
@@ -26,7 +26,7 @@ use crate::infer::{InferCtxt, RegionVariableOrigin, TypeVariableOrigin, TypeVari
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::GenericArg;
-use rustc_middle::ty::{self, BoundVar, List};
+use rustc_middle::ty::{self, List};
 use rustc_span::source_map::Span;
 
 pub use rustc_middle::infer::canonical::*;
@@ -87,12 +87,13 @@ impl<'tcx> InferCtxt<'tcx> {
         variables: &List<CanonicalVarInfo<'tcx>>,
         universe_map: impl Fn(ty::UniverseIndex) -> ty::UniverseIndex,
     ) -> CanonicalVarValues<'tcx> {
-        let var_values: IndexVec<BoundVar, GenericArg<'tcx>> = variables
-            .iter()
-            .map(|info| self.instantiate_canonical_var(span, info, &universe_map))
-            .collect();
-
-        CanonicalVarValues { var_values }
+        CanonicalVarValues {
+            var_values: self.tcx.mk_substs(
+                variables
+                    .iter()
+                    .map(|info| self.instantiate_canonical_var(span, info, &universe_map)),
+            ),
+        }
     }
 
     /// Given the "info" about a canonical variable, creates a fresh
diff --git a/compiler/rustc_infer/src/infer/canonical/query_response.rs b/compiler/rustc_infer/src/infer/canonical/query_response.rs
index 3d49182f0b8..3e8e7734a5a 100644
--- a/compiler/rustc_infer/src/infer/canonical/query_response.rs
+++ b/compiler/rustc_infer/src/infer/canonical/query_response.rs
@@ -17,7 +17,7 @@ use crate::infer::region_constraints::{Constraint, RegionConstraintData};
 use crate::infer::{InferCtxt, InferOk, InferResult, NllRegionVariableOrigin};
 use crate::traits::query::{Fallible, NoSolution};
 use crate::traits::{Obligation, ObligationCause, PredicateObligation};
-use crate::traits::{PredicateObligations, TraitEngine};
+use crate::traits::{PredicateObligations, TraitEngine, TraitEngineExt};
 use rustc_data_structures::captures::Captures;
 use rustc_index::vec::Idx;
 use rustc_index::vec::IndexVec;
@@ -482,11 +482,8 @@ impl<'tcx> InferCtxt<'tcx> {
         // given variable in the loop above, use that. Otherwise, use
         // a fresh inference variable.
         let result_subst = CanonicalVarValues {
-            var_values: query_response
-                .variables
-                .iter()
-                .enumerate()
-                .map(|(index, info)| {
+            var_values: self.tcx.mk_substs(query_response.variables.iter().enumerate().map(
+                |(index, info)| {
                     if info.is_existential() {
                         match opt_values[BoundVar::new(index)] {
                             Some(k) => k,
@@ -499,8 +496,8 @@ impl<'tcx> InferCtxt<'tcx> {
                             universe_map[u.as_usize()]
                         })
                     }
-                })
-                .collect(),
+                },
+            )),
         };
 
         let mut obligations = vec![];
diff --git a/compiler/rustc_infer/src/infer/canonical/substitute.rs b/compiler/rustc_infer/src/infer/canonical/substitute.rs
index 389afe22eb7..e77f2d37b7d 100644
--- a/compiler/rustc_infer/src/infer/canonical/substitute.rs
+++ b/compiler/rustc_infer/src/infer/canonical/substitute.rs
@@ -72,16 +72,15 @@ where
         value
     } else {
         let delegate = FnMutDelegate {
-            regions: &mut |br: ty::BoundRegion| match var_values.var_values[br.var].unpack() {
+            regions: &mut |br: ty::BoundRegion| match var_values[br.var].unpack() {
                 GenericArgKind::Lifetime(l) => l,
                 r => bug!("{:?} is a region but value is {:?}", br, r),
             },
-            types: &mut |bound_ty: ty::BoundTy| match var_values.var_values[bound_ty.var].unpack() {
+            types: &mut |bound_ty: ty::BoundTy| match var_values[bound_ty.var].unpack() {
                 GenericArgKind::Type(ty) => ty,
                 r => bug!("{:?} is a type but value is {:?}", bound_ty, r),
             },
-            consts: &mut |bound_ct: ty::BoundVar, _| match var_values.var_values[bound_ct].unpack()
-            {
+            consts: &mut |bound_ct: ty::BoundVar, _| match var_values[bound_ct].unpack() {
                 GenericArgKind::Const(ct) => ct,
                 c => bug!("{:?} is a const but value is {:?}", bound_ct, c),
             },
diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
index 72676b718fa..a567b6acdbe 100644
--- a/compiler/rustc_infer/src/infer/combine.rs
+++ b/compiler/rustc_infer/src/infer/combine.rs
@@ -37,7 +37,10 @@ use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, InferConst, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{
+    self, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
+    TypeVisitable,
+};
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::{Span, DUMMY_SP};
 
@@ -140,8 +143,6 @@ impl<'tcx> InferCtxt<'tcx> {
         let a = self.shallow_resolve(a);
         let b = self.shallow_resolve(b);
 
-        let a_is_expected = relation.a_is_expected();
-
         match (a.kind(), b.kind()) {
             (
                 ty::ConstKind::Infer(InferConst::Var(a_vid)),
@@ -158,11 +159,11 @@ impl<'tcx> InferCtxt<'tcx> {
             }
 
             (ty::ConstKind::Infer(InferConst::Var(vid)), _) => {
-                return self.unify_const_variable(relation.param_env(), vid, b, a_is_expected);
+                return self.unify_const_variable(vid, b);
             }
 
             (_, ty::ConstKind::Infer(InferConst::Var(vid))) => {
-                return self.unify_const_variable(relation.param_env(), vid, a, !a_is_expected);
+                return self.unify_const_variable(vid, a);
             }
             (ty::ConstKind::Unevaluated(..), _) if self.tcx.lazy_normalization() => {
                 // FIXME(#59490): Need to remove the leak check to accommodate
@@ -223,10 +224,8 @@ impl<'tcx> InferCtxt<'tcx> {
     #[instrument(level = "debug", skip(self))]
     fn unify_const_variable(
         &self,
-        param_env: ty::ParamEnv<'tcx>,
         target_vid: ty::ConstVid<'tcx>,
         ct: ty::Const<'tcx>,
-        vid_is_expected: bool,
     ) -> RelateResult<'tcx, ty::Const<'tcx>> {
         let (for_universe, span) = {
             let mut inner = self.inner.borrow_mut();
@@ -239,8 +238,12 @@ impl<'tcx> InferCtxt<'tcx> {
                 ConstVariableValue::Unknown { universe } => (universe, var_value.origin.span),
             }
         };
-        let value = ConstInferUnifier { infcx: self, span, param_env, for_universe, target_vid }
-            .relate(ct, ct)?;
+        let value = ct.try_fold_with(&mut ConstInferUnifier {
+            infcx: self,
+            span,
+            for_universe,
+            target_vid,
+        })?;
 
         self.inner.borrow_mut().const_unification_table().union_value(
             target_vid,
@@ -800,8 +803,6 @@ struct ConstInferUnifier<'cx, 'tcx> {
 
     span: Span,
 
-    param_env: ty::ParamEnv<'tcx>,
-
     for_universe: ty::UniverseIndex,
 
     /// The vid of the const variable that is in the process of being
@@ -810,61 +811,15 @@ struct ConstInferUnifier<'cx, 'tcx> {
     target_vid: ty::ConstVid<'tcx>,
 }
 
-// We use `TypeRelation` here to propagate `RelateResult` upwards.
-//
-// Both inputs are expected to be the same.
-impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.infcx.tcx
-    }
-
-    fn intercrate(&self) -> bool {
-        assert!(!self.infcx.intercrate);
-        false
-    }
-
-    fn param_env(&self) -> ty::ParamEnv<'tcx> {
-        self.param_env
-    }
-
-    fn tag(&self) -> &'static str {
-        "ConstInferUnifier"
-    }
-
-    fn a_is_expected(&self) -> bool {
-        true
-    }
-
-    fn mark_ambiguous(&mut self) {
-        bug!()
-    }
-
-    fn relate_with_variance<T: Relate<'tcx>>(
-        &mut self,
-        _variance: ty::Variance,
-        _info: ty::VarianceDiagInfo<'tcx>,
-        a: T,
-        b: T,
-    ) -> RelateResult<'tcx, T> {
-        // We don't care about variance here.
-        self.relate(a, b)
-    }
+impl<'tcx> FallibleTypeFolder<'tcx> for ConstInferUnifier<'_, 'tcx> {
+    type Error = TypeError<'tcx>;
 
-    fn binders<T>(
-        &mut self,
-        a: ty::Binder<'tcx, T>,
-        b: ty::Binder<'tcx, T>,
-    ) -> RelateResult<'tcx, ty::Binder<'tcx, T>>
-    where
-        T: Relate<'tcx>,
-    {
-        Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?))
+    fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
+        self.infcx.tcx
     }
 
     #[instrument(level = "debug", skip(self), ret)]
-    fn tys(&mut self, t: Ty<'tcx>, _t: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
-        debug_assert_eq!(t, _t);
-
+    fn try_fold_ty(&mut self, t: Ty<'tcx>) -> Result<Ty<'tcx>, TypeError<'tcx>> {
         match t.kind() {
             &ty::Infer(ty::TyVar(vid)) => {
                 let vid = self.infcx.inner.borrow_mut().type_variables().root_var(vid);
@@ -872,7 +827,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                 match probe {
                     TypeVariableValue::Known { value: u } => {
                         debug!("ConstOccursChecker: known value {:?}", u);
-                        self.tys(u, u)
+                        u.try_fold_with(self)
                     }
                     TypeVariableValue::Unknown { universe } => {
                         if self.for_universe.can_name(universe) {
@@ -892,16 +847,15 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                 }
             }
             ty::Infer(ty::IntVar(_) | ty::FloatVar(_)) => Ok(t),
-            _ => relate::super_relate_tys(self, t, t),
+            _ => t.try_super_fold_with(self),
         }
     }
 
-    fn regions(
+    #[instrument(level = "debug", skip(self), ret)]
+    fn try_fold_region(
         &mut self,
         r: ty::Region<'tcx>,
-        _r: ty::Region<'tcx>,
-    ) -> RelateResult<'tcx, ty::Region<'tcx>> {
-        debug_assert_eq!(r, _r);
+    ) -> Result<ty::Region<'tcx>, TypeError<'tcx>> {
         debug!("ConstInferUnifier: r={:?}", r);
 
         match *r {
@@ -930,14 +884,8 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         }
     }
 
-    #[instrument(level = "debug", skip(self))]
-    fn consts(
-        &mut self,
-        c: ty::Const<'tcx>,
-        _c: ty::Const<'tcx>,
-    ) -> RelateResult<'tcx, ty::Const<'tcx>> {
-        debug_assert_eq!(c, _c);
-
+    #[instrument(level = "debug", skip(self), ret)]
+    fn try_fold_const(&mut self, c: ty::Const<'tcx>) -> Result<ty::Const<'tcx>, TypeError<'tcx>> {
         match c.kind() {
             ty::ConstKind::Infer(InferConst::Var(vid)) => {
                 // Check if the current unification would end up
@@ -958,7 +906,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                 let var_value =
                     self.infcx.inner.borrow_mut().const_unification_table().probe_value(vid);
                 match var_value.val {
-                    ConstVariableValue::Known { value: u } => self.consts(u, u),
+                    ConstVariableValue::Known { value: u } => u.try_fold_with(self),
                     ConstVariableValue::Unknown { universe } => {
                         if self.for_universe.can_name(universe) {
                             Ok(c)
@@ -977,17 +925,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                     }
                 }
             }
-            ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs }) => {
-                let substs = self.relate_with_variance(
-                    ty::Variance::Invariant,
-                    ty::VarianceDiagInfo::default(),
-                    substs,
-                    substs,
-                )?;
-
-                Ok(self.tcx().mk_const(ty::UnevaluatedConst { def, substs }, c.ty()))
-            }
-            _ => relate::super_relate_consts(self, c, c),
+            _ => c.try_super_fold_with(self),
         }
     }
 }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 28fd03b878b..b11db8396c9 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -79,6 +79,7 @@ use std::path::PathBuf;
 use std::{cmp, fmt, iter};
 
 mod note;
+mod note_and_explain;
 mod suggest;
 
 pub(crate) mod need_type_info;
@@ -1344,8 +1345,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnDef(did1, substs1), ty::FnDef(did2, substs2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did1).subst(self.tcx, substs1);
-                let sig2 = self.tcx.bound_fn_sig(*did2).subst(self.tcx, substs2);
+                let sig1 = self.tcx.fn_sig(*did1).subst(self.tcx, substs1);
+                let sig2 = self.tcx.fn_sig(*did2).subst(self.tcx, substs2);
                 let mut values = self.cmp_fn_sig(&sig1, &sig2);
                 let path1 = format!(" {{{}}}", self.tcx.def_path_str_with_substs(*did1, substs1));
                 let path2 = format!(" {{{}}}", self.tcx.def_path_str_with_substs(*did2, substs2));
@@ -1356,7 +1357,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnDef(did1, substs1), ty::FnPtr(sig2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did1).subst(self.tcx, substs1);
+                let sig1 = self.tcx.fn_sig(*did1).subst(self.tcx, substs1);
                 let mut values = self.cmp_fn_sig(&sig1, sig2);
                 values.0.push_highlighted(format!(
                     " {{{}}}",
@@ -1366,7 +1367,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnPtr(sig1), ty::FnDef(did2, substs2)) => {
-                let sig2 = self.tcx.bound_fn_sig(*did2).subst(self.tcx, substs2);
+                let sig2 = self.tcx.fn_sig(*did2).subst(self.tcx, substs2);
                 let mut values = self.cmp_fn_sig(sig1, &sig2);
                 values.1.push_normal(format!(
                     " {{{}}}",
@@ -1841,19 +1842,13 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 self.suggest_as_ref_where_appropriate(span, &exp_found, diag);
                 self.suggest_accessing_field_where_appropriate(cause, &exp_found, diag);
                 self.suggest_await_on_expect_found(cause, span, &exp_found, diag);
+                self.suggest_function_pointers(cause, span, &exp_found, diag);
             }
         }
 
-        // In some (most?) cases cause.body_id points to actual body, but in some cases
-        // it's an actual definition. According to the comments (e.g. in
-        // rustc_hir_analysis/check/compare_impl_item.rs:compare_predicate_entailment) the latter
-        // is relied upon by some other code. This might (or might not) need cleanup.
-        let body_owner_def_id =
-            self.tcx.hir().opt_local_def_id(cause.body_id).unwrap_or_else(|| {
-                self.tcx.hir().body_owner_def_id(hir::BodyId { hir_id: cause.body_id })
-            });
         self.check_and_note_conflicting_crates(diag, terr);
-        self.tcx.note_and_explain_type_err(diag, terr, cause, span, body_owner_def_id.to_def_id());
+
+        self.note_and_explain_type_err(diag, terr, cause, span, cause.body_id.to_def_id());
 
         if let Some(ValuePairs::PolyTraitRefs(exp_found)) = values
             && let ty::Closure(def_id, _) = exp_found.expected.skip_binder().self_ty().kind()
@@ -2585,7 +2580,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
     /// with the other type. A TyVar inference type is compatible with any type, and an IntVar or
     /// FloatVar inference type are compatible with themselves or their concrete types (Int and
     /// Float types, respectively). When comparing two ADTs, these rules apply recursively.
-    pub fn same_type_modulo_infer(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
+    pub fn same_type_modulo_infer<T: relate::Relate<'tcx>>(&self, a: T, b: T) -> bool {
         let (a, b) = self.resolve_vars_if_possible((a, b));
         SameTypeModuloInfer(self).relate(a, b).is_ok()
     }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
index fd26d7d29c5..4c0f457b46a 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
@@ -65,7 +65,7 @@ pub fn find_param_with_region<'tcx>(
 
     let owner_id = hir.body_owner(body_id);
     let fn_decl = hir.fn_decl_by_hir_id(owner_id).unwrap();
-    let poly_fn_sig = tcx.fn_sig(id);
+    let poly_fn_sig = tcx.fn_sig(id).subst_identity();
 
     let fn_sig = tcx.liberate_late_bound_regions(id, poly_fn_sig);
     let body = hir.body(body_id);
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs
new file mode 100644
index 00000000000..34e8edd6140
--- /dev/null
+++ b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs
@@ -0,0 +1,654 @@
+use super::TypeErrCtxt;
+use rustc_errors::Applicability::{MachineApplicable, MaybeIncorrect};
+use rustc_errors::{pluralize, Diagnostic, MultiSpan};
+use rustc_hir::{self as hir, def::DefKind};
+use rustc_middle::traits::ObligationCauseCode;
+use rustc_middle::ty::error::ExpectedFound;
+use rustc_middle::ty::print::Printer;
+use rustc_middle::{
+    traits::ObligationCause,
+    ty::{self, error::TypeError, print::FmtPrinter, suggest_constraining_type_param, Ty},
+};
+use rustc_span::{def_id::DefId, sym, BytePos, Span, Symbol};
+
+impl<'tcx> TypeErrCtxt<'_, 'tcx> {
+    pub fn note_and_explain_type_err(
+        &self,
+        diag: &mut Diagnostic,
+        err: TypeError<'tcx>,
+        cause: &ObligationCause<'tcx>,
+        sp: Span,
+        body_owner_def_id: DefId,
+    ) {
+        use ty::error::TypeError::*;
+        debug!("note_and_explain_type_err err={:?} cause={:?}", err, cause);
+
+        let tcx = self.tcx;
+
+        match err {
+            ArgumentSorts(values, _) | Sorts(values) => {
+                match (values.expected.kind(), values.found.kind()) {
+                    (ty::Closure(..), ty::Closure(..)) => {
+                        diag.note("no two closures, even if identical, have the same type");
+                        diag.help("consider boxing your closure and/or using it as a trait object");
+                    }
+                    (ty::Alias(ty::Opaque, ..), ty::Alias(ty::Opaque, ..)) => {
+                        // Issue #63167
+                        diag.note("distinct uses of `impl Trait` result in different opaque types");
+                    }
+                    (ty::Float(_), ty::Infer(ty::IntVar(_)))
+                        if let Ok(
+                            // Issue #53280
+                            snippet,
+                        ) = tcx.sess.source_map().span_to_snippet(sp) =>
+                    {
+                        if snippet.chars().all(|c| c.is_digit(10) || c == '-' || c == '_') {
+                            diag.span_suggestion(
+                                sp,
+                                "use a float literal",
+                                format!("{}.0", snippet),
+                                MachineApplicable,
+                            );
+                        }
+                    }
+                    (ty::Param(expected), ty::Param(found)) => {
+                        let generics = tcx.generics_of(body_owner_def_id);
+                        let e_span = tcx.def_span(generics.type_param(expected, tcx).def_id);
+                        if !sp.contains(e_span) {
+                            diag.span_label(e_span, "expected type parameter");
+                        }
+                        let f_span = tcx.def_span(generics.type_param(found, tcx).def_id);
+                        if !sp.contains(f_span) {
+                            diag.span_label(f_span, "found type parameter");
+                        }
+                        diag.note(
+                            "a type parameter was expected, but a different one was found; \
+                             you might be missing a type parameter or trait bound",
+                        );
+                        diag.note(
+                            "for more information, visit \
+                             https://doc.rust-lang.org/book/ch10-02-traits.html\
+                             #traits-as-parameters",
+                        );
+                    }
+                    (ty::Alias(ty::Projection, _), ty::Alias(ty::Projection, _)) => {
+                        diag.note("an associated type was expected, but a different one was found");
+                    }
+                    (ty::Param(p), ty::Alias(ty::Projection, proj)) | (ty::Alias(ty::Projection, proj), ty::Param(p))
+                        if tcx.def_kind(proj.def_id) != DefKind::ImplTraitPlaceholder =>
+                    {
+                        let generics = tcx.generics_of(body_owner_def_id);
+                        let p_span = tcx.def_span(generics.type_param(p, tcx).def_id);
+                        if !sp.contains(p_span) {
+                            diag.span_label(p_span, "this type parameter");
+                        }
+                        let hir = tcx.hir();
+                        let mut note = true;
+                        if let Some(generics) = generics
+                            .type_param(p, tcx)
+                            .def_id
+                            .as_local()
+                            .map(|id| hir.local_def_id_to_hir_id(id))
+                            .and_then(|id| tcx.hir().find_parent(id))
+                            .as_ref()
+                            .and_then(|node| node.generics())
+                        {
+                            // Synthesize the associated type restriction `Add<Output = Expected>`.
+                            // FIXME: extract this logic for use in other diagnostics.
+                            let (trait_ref, assoc_substs) = proj.trait_ref_and_own_substs(tcx);
+                            let path =
+                                tcx.def_path_str_with_substs(trait_ref.def_id, trait_ref.substs);
+                            let item_name = tcx.item_name(proj.def_id);
+                            let item_args = self.format_generic_args(assoc_substs);
+
+                            let path = if path.ends_with('>') {
+                                format!(
+                                    "{}, {}{} = {}>",
+                                    &path[..path.len() - 1],
+                                    item_name,
+                                    item_args,
+                                    p
+                                )
+                            } else {
+                                format!("{}<{}{} = {}>", path, item_name, item_args, p)
+                            };
+                            note = !suggest_constraining_type_param(
+                                tcx,
+                                generics,
+                                diag,
+                                &format!("{}", proj.self_ty()),
+                                &path,
+                                None,
+                            );
+                        }
+                        if note {
+                            diag.note("you might be missing a type parameter or trait bound");
+                        }
+                    }
+                    (ty::Param(p), ty::Dynamic(..) | ty::Alias(ty::Opaque, ..))
+                    | (ty::Dynamic(..) | ty::Alias(ty::Opaque, ..), ty::Param(p)) => {
+                        let generics = tcx.generics_of(body_owner_def_id);
+                        let p_span = tcx.def_span(generics.type_param(p, tcx).def_id);
+                        if !sp.contains(p_span) {
+                            diag.span_label(p_span, "this type parameter");
+                        }
+                        diag.help("type parameters must be constrained to match other types");
+                        if tcx.sess.teach(&diag.get_code().unwrap()) {
+                            diag.help(
+                                "given a type parameter `T` and a method `foo`:
+```
+trait Trait<T> { fn foo(&tcx) -> T; }
+```
+the only ways to implement method `foo` are:
+- constrain `T` with an explicit type:
+```
+impl Trait<String> for X {
+    fn foo(&tcx) -> String { String::new() }
+}
+```
+- add a trait bound to `T` and call a method on that trait that returns `Self`:
+```
+impl<T: std::default::Default> Trait<T> for X {
+    fn foo(&tcx) -> T { <T as std::default::Default>::default() }
+}
+```
+- change `foo` to return an argument of type `T`:
+```
+impl<T> Trait<T> for X {
+    fn foo(&tcx, x: T) -> T { x }
+}
+```",
+                            );
+                        }
+                        diag.note(
+                            "for more information, visit \
+                             https://doc.rust-lang.org/book/ch10-02-traits.html\
+                             #traits-as-parameters",
+                        );
+                    }
+                    (ty::Param(p), ty::Closure(..) | ty::Generator(..)) => {
+                        let generics = tcx.generics_of(body_owner_def_id);
+                        let p_span = tcx.def_span(generics.type_param(p, tcx).def_id);
+                        if !sp.contains(p_span) {
+                            diag.span_label(p_span, "this type parameter");
+                        }
+                        diag.help(&format!(
+                            "every closure has a distinct type and so could not always match the \
+                             caller-chosen type of parameter `{}`",
+                            p
+                        ));
+                    }
+                    (ty::Param(p), _) | (_, ty::Param(p)) => {
+                        let generics = tcx.generics_of(body_owner_def_id);
+                        let p_span = tcx.def_span(generics.type_param(p, tcx).def_id);
+                        if !sp.contains(p_span) {
+                            diag.span_label(p_span, "this type parameter");
+                        }
+                    }
+                    (ty::Alias(ty::Projection, proj_ty), _) if tcx.def_kind(proj_ty.def_id) != DefKind::ImplTraitPlaceholder => {
+                        self.expected_projection(
+                            diag,
+                            proj_ty,
+                            values,
+                            body_owner_def_id,
+                            cause.code(),
+                        );
+                    }
+                    (_, ty::Alias(ty::Projection, proj_ty)) if tcx.def_kind(proj_ty.def_id) != DefKind::ImplTraitPlaceholder => {
+                        let msg = format!(
+                            "consider constraining the associated type `{}` to `{}`",
+                            values.found, values.expected,
+                        );
+                        if !(self.suggest_constraining_opaque_associated_type(
+                            diag,
+                            &msg,
+                            proj_ty,
+                            values.expected,
+                        ) || self.suggest_constraint(
+                            diag,
+                            &msg,
+                            body_owner_def_id,
+                            proj_ty,
+                            values.expected,
+                        )) {
+                            diag.help(&msg);
+                            diag.note(
+                                "for more information, visit \
+                                https://doc.rust-lang.org/book/ch19-03-advanced-traits.html",
+                            );
+                        }
+                    }
+                    _ => {}
+                }
+                debug!(
+                    "note_and_explain_type_err expected={:?} ({:?}) found={:?} ({:?})",
+                    values.expected,
+                    values.expected.kind(),
+                    values.found,
+                    values.found.kind(),
+                );
+            }
+            CyclicTy(ty) => {
+                // Watch out for various cases of cyclic types and try to explain.
+                if ty.is_closure() || ty.is_generator() {
+                    diag.note(
+                        "closures cannot capture themselves or take themselves as argument;\n\
+                         this error may be the result of a recent compiler bug-fix,\n\
+                         see issue #46062 <https://github.com/rust-lang/rust/issues/46062>\n\
+                         for more information",
+                    );
+                }
+            }
+            TargetFeatureCast(def_id) => {
+                let target_spans = tcx.get_attrs(def_id, sym::target_feature).map(|attr| attr.span);
+                diag.note(
+                    "functions with `#[target_feature]` can only be coerced to `unsafe` function pointers"
+                );
+                diag.span_labels(target_spans, "`#[target_feature]` added here");
+            }
+            _ => {}
+        }
+    }
+
+    fn suggest_constraint(
+        &self,
+        diag: &mut Diagnostic,
+        msg: &str,
+        body_owner_def_id: DefId,
+        proj_ty: &ty::AliasTy<'tcx>,
+        ty: Ty<'tcx>,
+    ) -> bool {
+        let tcx = self.tcx;
+        let assoc = tcx.associated_item(proj_ty.def_id);
+        let (trait_ref, assoc_substs) = proj_ty.trait_ref_and_own_substs(tcx);
+        if let Some(item) = tcx.hir().get_if_local(body_owner_def_id) {
+            if let Some(hir_generics) = item.generics() {
+                // Get the `DefId` for the type parameter corresponding to `A` in `<A as T>::Foo`.
+                // This will also work for `impl Trait`.
+                let def_id = if let ty::Param(param_ty) = proj_ty.self_ty().kind() {
+                    let generics = tcx.generics_of(body_owner_def_id);
+                    generics.type_param(param_ty, tcx).def_id
+                } else {
+                    return false;
+                };
+                let Some(def_id) = def_id.as_local() else {
+                    return false;
+                };
+
+                // First look in the `where` clause, as this might be
+                // `fn foo<T>(x: T) where T: Trait`.
+                for pred in hir_generics.bounds_for_param(def_id) {
+                    if self.constrain_generic_bound_associated_type_structured_suggestion(
+                        diag,
+                        &trait_ref,
+                        pred.bounds,
+                        &assoc,
+                        assoc_substs,
+                        ty,
+                        msg,
+                        false,
+                    ) {
+                        return true;
+                    }
+                }
+            }
+        }
+        false
+    }
+
+    /// An associated type was expected and a different type was found.
+    ///
+    /// We perform a few different checks to see what we can suggest:
+    ///
+    ///  - In the current item, look for associated functions that return the expected type and
+    ///    suggest calling them. (Not a structured suggestion.)
+    ///  - If any of the item's generic bounds can be constrained, we suggest constraining the
+    ///    associated type to the found type.
+    ///  - If the associated type has a default type and was expected inside of a `trait`, we
+    ///    mention that this is disallowed.
+    ///  - If all other things fail, and the error is not because of a mismatch between the `trait`
+    ///    and the `impl`, we provide a generic `help` to constrain the assoc type or call an assoc
+    ///    fn that returns the type.
+    fn expected_projection(
+        &self,
+        diag: &mut Diagnostic,
+        proj_ty: &ty::AliasTy<'tcx>,
+        values: ExpectedFound<Ty<'tcx>>,
+        body_owner_def_id: DefId,
+        cause_code: &ObligationCauseCode<'_>,
+    ) {
+        let tcx = self.tcx;
+
+        let msg = format!(
+            "consider constraining the associated type `{}` to `{}`",
+            values.expected, values.found
+        );
+        let body_owner = tcx.hir().get_if_local(body_owner_def_id);
+        let current_method_ident = body_owner.and_then(|n| n.ident()).map(|i| i.name);
+
+        // We don't want to suggest calling an assoc fn in a scope where that isn't feasible.
+        let callable_scope = matches!(
+            body_owner,
+            Some(
+                hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(..), .. })
+                    | hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
+                    | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }),
+            )
+        );
+        let impl_comparison =
+            matches!(cause_code, ObligationCauseCode::CompareImplItemObligation { .. });
+        let assoc = tcx.associated_item(proj_ty.def_id);
+        if !callable_scope || impl_comparison {
+            // We do not want to suggest calling functions when the reason of the
+            // type error is a comparison of an `impl` with its `trait` or when the
+            // scope is outside of a `Body`.
+        } else {
+            // If we find a suitable associated function that returns the expected type, we don't
+            // want the more general suggestion later in this method about "consider constraining
+            // the associated type or calling a method that returns the associated type".
+            let point_at_assoc_fn = self.point_at_methods_that_satisfy_associated_type(
+                diag,
+                assoc.container_id(tcx),
+                current_method_ident,
+                proj_ty.def_id,
+                values.expected,
+            );
+            // Possibly suggest constraining the associated type to conform to the
+            // found type.
+            if self.suggest_constraint(diag, &msg, body_owner_def_id, proj_ty, values.found)
+                || point_at_assoc_fn
+            {
+                return;
+            }
+        }
+
+        self.suggest_constraining_opaque_associated_type(diag, &msg, proj_ty, values.found);
+
+        if self.point_at_associated_type(diag, body_owner_def_id, values.found) {
+            return;
+        }
+
+        if !impl_comparison {
+            // Generic suggestion when we can't be more specific.
+            if callable_scope {
+                diag.help(&format!(
+                    "{} or calling a method that returns `{}`",
+                    msg, values.expected
+                ));
+            } else {
+                diag.help(&msg);
+            }
+            diag.note(
+                "for more information, visit \
+                 https://doc.rust-lang.org/book/ch19-03-advanced-traits.html",
+            );
+        }
+        if tcx.sess.teach(&diag.get_code().unwrap()) {
+            diag.help(
+                "given an associated type `T` and a method `foo`:
+```
+trait Trait {
+type T;
+fn foo(&tcx) -> Self::T;
+}
+```
+the only way of implementing method `foo` is to constrain `T` with an explicit associated type:
+```
+impl Trait for X {
+type T = String;
+fn foo(&tcx) -> Self::T { String::new() }
+}
+```",
+            );
+        }
+    }
+
+    /// When the expected `impl Trait` is not defined in the current item, it will come from
+    /// a return type. This can occur when dealing with `TryStream` (#71035).
+    fn suggest_constraining_opaque_associated_type(
+        &self,
+        diag: &mut Diagnostic,
+        msg: &str,
+        proj_ty: &ty::AliasTy<'tcx>,
+        ty: Ty<'tcx>,
+    ) -> bool {
+        let tcx = self.tcx;
+
+        let assoc = tcx.associated_item(proj_ty.def_id);
+        if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *proj_ty.self_ty().kind() {
+            let opaque_local_def_id = def_id.as_local();
+            let opaque_hir_ty = if let Some(opaque_local_def_id) = opaque_local_def_id {
+                match &tcx.hir().expect_item(opaque_local_def_id).kind {
+                    hir::ItemKind::OpaqueTy(opaque_hir_ty) => opaque_hir_ty,
+                    _ => bug!("The HirId comes from a `ty::Opaque`"),
+                }
+            } else {
+                return false;
+            };
+
+            let (trait_ref, assoc_substs) = proj_ty.trait_ref_and_own_substs(tcx);
+
+            self.constrain_generic_bound_associated_type_structured_suggestion(
+                diag,
+                &trait_ref,
+                opaque_hir_ty.bounds,
+                assoc,
+                assoc_substs,
+                ty,
+                msg,
+                true,
+            )
+        } else {
+            false
+        }
+    }
+
+    fn point_at_methods_that_satisfy_associated_type(
+        &self,
+        diag: &mut Diagnostic,
+        assoc_container_id: DefId,
+        current_method_ident: Option<Symbol>,
+        proj_ty_item_def_id: DefId,
+        expected: Ty<'tcx>,
+    ) -> bool {
+        let tcx = self.tcx;
+
+        let items = tcx.associated_items(assoc_container_id);
+        // Find all the methods in the trait that could be called to construct the
+        // expected associated type.
+        // FIXME: consider suggesting the use of associated `const`s.
+        let methods: Vec<(Span, String)> = items
+            .in_definition_order()
+            .filter(|item| {
+                ty::AssocKind::Fn == item.kind && Some(item.name) != current_method_ident
+            })
+            .filter_map(|item| {
+                let method = tcx.fn_sig(item.def_id).subst_identity();
+                match *method.output().skip_binder().kind() {
+                    ty::Alias(ty::Projection, ty::AliasTy { def_id: item_def_id, .. })
+                        if item_def_id == proj_ty_item_def_id =>
+                    {
+                        Some((
+                            tcx.def_span(item.def_id),
+                            format!("consider calling `{}`", tcx.def_path_str(item.def_id)),
+                        ))
+                    }
+                    _ => None,
+                }
+            })
+            .collect();
+        if !methods.is_empty() {
+            // Use a single `help:` to show all the methods in the trait that can
+            // be used to construct the expected associated type.
+            let mut span: MultiSpan =
+                methods.iter().map(|(sp, _)| *sp).collect::<Vec<Span>>().into();
+            let msg = format!(
+                "{some} method{s} {are} available that return{r} `{ty}`",
+                some = if methods.len() == 1 { "a" } else { "some" },
+                s = pluralize!(methods.len()),
+                are = pluralize!("is", methods.len()),
+                r = if methods.len() == 1 { "s" } else { "" },
+                ty = expected
+            );
+            for (sp, label) in methods.into_iter() {
+                span.push_span_label(sp, label);
+            }
+            diag.span_help(span, &msg);
+            return true;
+        }
+        false
+    }
+
+    fn point_at_associated_type(
+        &self,
+        diag: &mut Diagnostic,
+        body_owner_def_id: DefId,
+        found: Ty<'tcx>,
+    ) -> bool {
+        let tcx = self.tcx;
+
+        let Some(hir_id) = body_owner_def_id.as_local() else {
+            return false;
+        };
+        let hir_id = tcx.hir().local_def_id_to_hir_id(hir_id);
+        // When `body_owner` is an `impl` or `trait` item, look in its associated types for
+        // `expected` and point at it.
+        let parent_id = tcx.hir().get_parent_item(hir_id);
+        let item = tcx.hir().find_by_def_id(parent_id.def_id);
+
+        debug!("expected_projection parent item {:?}", item);
+
+        let param_env = tcx.param_env(body_owner_def_id);
+
+        match item {
+            Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Trait(.., items), .. })) => {
+                // FIXME: account for `#![feature(specialization)]`
+                for item in &items[..] {
+                    match item.kind {
+                        hir::AssocItemKind::Type => {
+                            // FIXME: account for returning some type in a trait fn impl that has
+                            // an assoc type as a return type (#72076).
+                            if let hir::Defaultness::Default { has_value: true } =
+                                tcx.impl_defaultness(item.id.owner_id)
+                            {
+                                let assoc_ty = tcx.bound_type_of(item.id.owner_id).subst_identity();
+                                if self.infcx.can_eq(param_env, assoc_ty, found).is_ok() {
+                                    diag.span_label(
+                                        item.span,
+                                        "associated type defaults can't be assumed inside the \
+                                            trait defining them",
+                                    );
+                                    return true;
+                                }
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            Some(hir::Node::Item(hir::Item {
+                kind: hir::ItemKind::Impl(hir::Impl { items, .. }),
+                ..
+            })) => {
+                for item in &items[..] {
+                    if let hir::AssocItemKind::Type = item.kind {
+                        let assoc_ty = tcx.bound_type_of(item.id.owner_id).subst_identity();
+
+                        if self.infcx.can_eq(param_env, assoc_ty, found).is_ok() {
+                            diag.span_label(item.span, "expected this associated type");
+                            return true;
+                        }
+                    }
+                }
+            }
+            _ => {}
+        }
+        false
+    }
+
+    /// Given a slice of `hir::GenericBound`s, if any of them corresponds to the `trait_ref`
+    /// requirement, provide a structured suggestion to constrain it to a given type `ty`.
+    ///
+    /// `is_bound_surely_present` indicates whether we know the bound we're looking for is
+    /// inside `bounds`. If that's the case then we can consider `bounds` containing only one
+    /// trait bound as the one we're looking for. This can help in cases where the associated
+    /// type is defined on a supertrait of the one present in the bounds.
+    fn constrain_generic_bound_associated_type_structured_suggestion(
+        &self,
+        diag: &mut Diagnostic,
+        trait_ref: &ty::TraitRef<'tcx>,
+        bounds: hir::GenericBounds<'_>,
+        assoc: &ty::AssocItem,
+        assoc_substs: &[ty::GenericArg<'tcx>],
+        ty: Ty<'tcx>,
+        msg: &str,
+        is_bound_surely_present: bool,
+    ) -> bool {
+        // FIXME: we would want to call `resolve_vars_if_possible` on `ty` before suggesting.
+
+        let trait_bounds = bounds.iter().filter_map(|bound| match bound {
+            hir::GenericBound::Trait(ptr, hir::TraitBoundModifier::None) => Some(ptr),
+            _ => None,
+        });
+
+        let matching_trait_bounds = trait_bounds
+            .clone()
+            .filter(|ptr| ptr.trait_ref.trait_def_id() == Some(trait_ref.def_id))
+            .collect::<Vec<_>>();
+
+        let span = match &matching_trait_bounds[..] {
+            &[ptr] => ptr.span,
+            &[] if is_bound_surely_present => match &trait_bounds.collect::<Vec<_>>()[..] {
+                &[ptr] => ptr.span,
+                _ => return false,
+            },
+            _ => return false,
+        };
+
+        self.constrain_associated_type_structured_suggestion(
+            diag,
+            span,
+            assoc,
+            assoc_substs,
+            ty,
+            msg,
+        )
+    }
+
+    /// Given a span corresponding to a bound, provide a structured suggestion to set an
+    /// associated type to a given type `ty`.
+    fn constrain_associated_type_structured_suggestion(
+        &self,
+        diag: &mut Diagnostic,
+        span: Span,
+        assoc: &ty::AssocItem,
+        assoc_substs: &[ty::GenericArg<'tcx>],
+        ty: Ty<'tcx>,
+        msg: &str,
+    ) -> bool {
+        let tcx = self.tcx;
+
+        if let Ok(has_params) =
+            tcx.sess.source_map().span_to_snippet(span).map(|snippet| snippet.ends_with('>'))
+        {
+            let (span, sugg) = if has_params {
+                let pos = span.hi() - BytePos(1);
+                let span = Span::new(pos, pos, span.ctxt(), span.parent());
+                (span, format!(", {} = {}", assoc.ident(tcx), ty))
+            } else {
+                let item_args = self.format_generic_args(assoc_substs);
+                (span.shrink_to_hi(), format!("<{}{} = {}>", assoc.ident(tcx), item_args, ty))
+            };
+            diag.span_suggestion_verbose(span, msg, sugg, MaybeIncorrect);
+            return true;
+        }
+        false
+    }
+
+    pub fn format_generic_args(&self, args: &[ty::GenericArg<'tcx>]) -> String {
+        FmtPrinter::new(self.tcx, hir::def::Namespace::TypeNS)
+            .path_generic_args(Ok, args)
+            .expect("could not write to `String`.")
+            .into_buffer()
+    }
+}
diff --git a/compiler/rustc_infer/src/infer/error_reporting/suggest.rs b/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
index 5b02956a106..23063e80b05 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
@@ -8,7 +8,7 @@ use rustc_middle::traits::{
     StatementAsExpression,
 };
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self as ty, Ty, TypeVisitable};
+use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TypeVisitable};
 use rustc_span::{sym, BytePos, Span};
 
 use crate::errors::SuggAddLetForLetChains;
@@ -351,6 +351,118 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         }
     }
 
+    pub(super) fn suggest_function_pointers(
+        &self,
+        cause: &ObligationCause<'tcx>,
+        span: Span,
+        exp_found: &ty::error::ExpectedFound<Ty<'tcx>>,
+        diag: &mut Diagnostic,
+    ) {
+        debug!("suggest_function_pointers(cause={:?}, exp_found={:?})", cause, exp_found);
+        let ty::error::ExpectedFound { expected, found } = exp_found;
+        let expected_inner = expected.peel_refs();
+        let found_inner = found.peel_refs();
+        if !expected_inner.is_fn() || !found_inner.is_fn() {
+            return;
+        }
+        match (&expected_inner.kind(), &found_inner.kind()) {
+            (ty::FnPtr(sig), ty::FnDef(did, substs)) => {
+                let expected_sig = &(self.normalize_fn_sig)(*sig);
+                let found_sig =
+                    &(self.normalize_fn_sig)(self.tcx.fn_sig(*did).subst(self.tcx, substs));
+
+                let fn_name = self.tcx.def_path_str_with_substs(*did, substs);
+
+                if !self.same_type_modulo_infer(*found_sig, *expected_sig)
+                    || !sig.is_suggestable(self.tcx, true)
+                    || ty::util::is_intrinsic(self.tcx, *did)
+                {
+                    return;
+                }
+
+                let (msg, sug) = match (expected.is_ref(), found.is_ref()) {
+                    (true, false) => {
+                        let msg = "consider using a reference";
+                        let sug = format!("&{fn_name}");
+                        (msg, sug)
+                    }
+                    (false, true) => {
+                        let msg = "consider removing the reference";
+                        let sug = format!("{fn_name}");
+                        (msg, sug)
+                    }
+                    (true, true) => {
+                        diag.note("fn items are distinct from fn pointers");
+                        let msg = "consider casting to a fn pointer";
+                        let sug = format!("&({fn_name} as {sig})");
+                        (msg, sug)
+                    }
+                    (false, false) => {
+                        diag.note("fn items are distinct from fn pointers");
+                        let msg = "consider casting to a fn pointer";
+                        let sug = format!("{fn_name} as {sig}");
+                        (msg, sug)
+                    }
+                };
+                diag.span_suggestion(span, msg, sug, Applicability::MaybeIncorrect);
+            }
+            (ty::FnDef(did1, substs1), ty::FnDef(did2, substs2)) => {
+                let expected_sig =
+                    &(self.normalize_fn_sig)(self.tcx.fn_sig(*did1).subst(self.tcx, substs1));
+                let found_sig =
+                    &(self.normalize_fn_sig)(self.tcx.fn_sig(*did2).subst(self.tcx, substs2));
+
+                if self.same_type_modulo_infer(*expected_sig, *found_sig) {
+                    diag.note("different fn items have unique types, even if their signatures are the same");
+                }
+
+                if !self.same_type_modulo_infer(*found_sig, *expected_sig)
+                    || !found_sig.is_suggestable(self.tcx, true)
+                    || !expected_sig.is_suggestable(self.tcx, true)
+                    || ty::util::is_intrinsic(self.tcx, *did1)
+                    || ty::util::is_intrinsic(self.tcx, *did2)
+                {
+                    return;
+                }
+
+                let fn_name = self.tcx.def_path_str_with_substs(*did2, substs2);
+                let sug = if found.is_ref() {
+                    format!("&({fn_name} as {found_sig})")
+                } else {
+                    format!("{fn_name} as {found_sig}")
+                };
+
+                let msg = format!(
+                    "consider casting both fn items to fn pointers using `as {expected_sig}`"
+                );
+
+                diag.span_suggestion_hidden(span, msg, sug, Applicability::MaybeIncorrect);
+            }
+            (ty::FnDef(did, substs), ty::FnPtr(sig)) => {
+                let expected_sig =
+                    &(self.normalize_fn_sig)(self.tcx.fn_sig(*did).subst(self.tcx, substs));
+                let found_sig = &(self.normalize_fn_sig)(*sig);
+
+                if !self.same_type_modulo_infer(*found_sig, *expected_sig) {
+                    return;
+                }
+
+                let fn_name = self.tcx.def_path_str_with_substs(*did, substs);
+
+                let casting = if expected.is_ref() {
+                    format!("&({fn_name} as {found_sig})")
+                } else {
+                    format!("{fn_name} as {found_sig}")
+                };
+
+                diag.help(&format!("consider casting the fn item to a fn pointer: `{}`", casting));
+            }
+            _ => {
+                return;
+            }
+        };
+    }
+
     pub fn should_suggest_as_ref(&self, expected: Ty<'tcx>, found: Ty<'tcx>) -> Option<&str> {
         if let (ty::Adt(exp_def, exp_substs), ty::Ref(_, found_ty, _)) =
             (expected.kind(), found.kind())
@@ -411,8 +523,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         span: Span,
     ) {
         let hir = self.tcx.hir();
-        let fn_hir_id = hir.parent_id(cause.body_id);
-        if let Some(node) = self.tcx.hir().find(fn_hir_id) &&
+        if let Some(node) = self.tcx.hir().find_by_def_id(cause.body_id) &&
             let hir::Node::Item(hir::Item {
                     kind: hir::ItemKind::Fn(_sig, _, body_id), ..
                 }) = node {
diff --git a/compiler/rustc_infer/src/infer/freshen.rs b/compiler/rustc_infer/src/infer/freshen.rs
index 8f53b1ccdf4..83d71edc2ab 100644
--- a/compiler/rustc_infer/src/infer/freshen.rs
+++ b/compiler/rustc_infer/src/infer/freshen.rs
@@ -209,6 +209,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> {
             | ty::Foreign(..)
             | ty::Param(..)
             | ty::Closure(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::GeneratorWitness(..) => t.super_fold_with(self),
 
             ty::Placeholder(..) | ty::Bound(..) => bug!("unexpected type {:?}", t),
diff --git a/compiler/rustc_infer/src/infer/glb.rs b/compiler/rustc_infer/src/infer/glb.rs
index 21b68ce9989..b92b162a978 100644
--- a/compiler/rustc_infer/src/infer/glb.rs
+++ b/compiler/rustc_infer/src/infer/glb.rs
@@ -79,7 +79,8 @@ impl<'tcx> TypeRelation<'tcx> for Glb<'_, '_, 'tcx> {
         debug!("{}.regions({:?}, {:?})", self.tag(), a, b);
 
         let origin = Subtype(Box::new(self.fields.trace.clone()));
-        Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().glb_regions(
+        // GLB(&'static u8, &'a u8) == &RegionLUB('static, 'a) u8 == &'static u8
+        Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().lub_regions(
             self.tcx(),
             origin,
             a,
diff --git a/compiler/rustc_infer/src/infer/lub.rs b/compiler/rustc_infer/src/infer/lub.rs
index c07ac1d3ace..f6e0554fd1f 100644
--- a/compiler/rustc_infer/src/infer/lub.rs
+++ b/compiler/rustc_infer/src/infer/lub.rs
@@ -79,7 +79,8 @@ impl<'tcx> TypeRelation<'tcx> for Lub<'_, '_, 'tcx> {
         debug!("{}.regions({:?}, {:?})", self.tag(), a, b);
 
         let origin = Subtype(Box::new(self.fields.trace.clone()));
-        Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().lub_regions(
+        // LUB(&'static u8, &'a u8) == &RegionGLB('static, 'a) u8 == &'a u8
+        Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().glb_regions(
             self.tcx(),
             origin,
             a,
diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
index f235cb5ab45..f83219b8ee2 100644
--- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs
+++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
@@ -663,13 +663,13 @@ where
         debug!(?v_b);
 
         if self.ambient_covariance() {
-            // Covariance: a <= b. Hence, `b: a`.
-            self.push_outlives(v_b, v_a, self.ambient_variance_info);
+            // Covariant: &'a u8 <: &'b u8. Hence, `'a: 'b`.
+            self.push_outlives(v_a, v_b, self.ambient_variance_info);
         }
 
         if self.ambient_contravariance() {
-            // Contravariant: b <= a. Hence, `a: b`.
-            self.push_outlives(v_a, v_b, self.ambient_variance_info);
+            // Contravariant: &'b u8 <: &'a u8. Hence, `'b: 'a`.
+            self.push_outlives(v_b, v_a, self.ambient_variance_info);
         }
 
         Ok(a)
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index c54c66eab27..b68b0baaa40 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -3,7 +3,7 @@ use crate::infer::{DefiningAnchor, InferCtxt, InferOk};
 use crate::traits;
 use hir::def::DefKind;
 use hir::def_id::{DefId, LocalDefId};
-use hir::{HirId, OpaqueTyOrigin};
+use hir::OpaqueTyOrigin;
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::vec_map::VecMap;
 use rustc_hir as hir;
@@ -48,7 +48,7 @@ impl<'tcx> InferCtxt<'tcx> {
     pub fn replace_opaque_types_with_inference_vars<T: TypeFoldable<'tcx>>(
         &self,
         value: T,
-        body_id: HirId,
+        body_id: LocalDefId,
         span: Span,
         param_env: ty::ParamEnv<'tcx>,
     ) -> InferOk<'tcx, T> {
diff --git a/compiler/rustc_infer/src/infer/outlives/components.rs b/compiler/rustc_infer/src/infer/outlives/components.rs
index 3d86279b03c..e3d95669171 100644
--- a/compiler/rustc_infer/src/infer/outlives/components.rs
+++ b/compiler/rustc_infer/src/infer/outlives/components.rs
@@ -112,7 +112,7 @@ fn compute_components<'tcx>(
             }
 
             // All regions are bound inside a witness
-            ty::GeneratorWitness(..) => (),
+            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => (),
 
             // OutlivesTypeParameterEnv -- the actual checking that `X:'a`
             // is implied by the environment is done in regionck.
diff --git a/compiler/rustc_infer/src/infer/sub.rs b/compiler/rustc_infer/src/infer/sub.rs
index bd38b52ba34..51c34f0d55f 100644
--- a/compiler/rustc_infer/src/infer/sub.rs
+++ b/compiler/rustc_infer/src/infer/sub.rs
@@ -191,12 +191,13 @@ impl<'tcx> TypeRelation<'tcx> for Sub<'_, '_, 'tcx> {
         // from the "cause" field, we could perhaps give more tailored
         // error messages.
         let origin = SubregionOrigin::Subtype(Box::new(self.fields.trace.clone()));
+        // Subtype(&'a u8, &'b u8) => Outlives('a: 'b) => SubRegion('b, 'a)
         self.fields
             .infcx
             .inner
             .borrow_mut()
             .unwrap_region_constraints()
-            .make_subregion(origin, a, b);
+            .make_subregion(origin, b, a);
 
         Ok(a)
     }
diff --git a/compiler/rustc_infer/src/traits/engine.rs b/compiler/rustc_infer/src/traits/engine.rs
index fcde00056cb..f75344f20b6 100644
--- a/compiler/rustc_infer/src/traits/engine.rs
+++ b/compiler/rustc_infer/src/traits/engine.rs
@@ -36,11 +36,19 @@ pub trait TraitEngine<'tcx>: 'tcx {
         obligation: PredicateObligation<'tcx>,
     );
 
-    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
-
     fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 
+    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>>;
+
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>>;
+
+    /// Among all pending obligations, collect those are stalled on a inference variable which has
+    /// changed since the last call to `select_where_possible`. Those obligations are marked as
+    /// successful and returned.
+    fn drain_unstalled_obligations(
+        &mut self,
+        infcx: &InferCtxt<'tcx>,
+    ) -> Vec<PredicateObligation<'tcx>>;
 }
 
 pub trait TraitEngineExt<'tcx> {
@@ -49,6 +57,8 @@ pub trait TraitEngineExt<'tcx> {
         infcx: &InferCtxt<'tcx>,
         obligations: impl IntoIterator<Item = PredicateObligation<'tcx>>,
     );
+
+    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 }
 
 impl<'tcx, T: ?Sized + TraitEngine<'tcx>> TraitEngineExt<'tcx> for T {
@@ -61,4 +71,13 @@ impl<'tcx, T: ?Sized + TraitEngine<'tcx>> TraitEngineExt<'tcx> for T {
             self.register_predicate_obligation(infcx, obligation);
         }
     }
+
+    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {
+        let errors = self.select_where_possible(infcx);
+        if !errors.is_empty() {
+            return errors;
+        }
+
+        self.collect_remaining_errors()
+    }
 }
diff --git a/compiler/rustc_infer/src/traits/mod.rs b/compiler/rustc_infer/src/traits/mod.rs
index 026713b6a28..3a82899660b 100644
--- a/compiler/rustc_infer/src/traits/mod.rs
+++ b/compiler/rustc_infer/src/traits/mod.rs
@@ -8,6 +8,7 @@ mod project;
 mod structural_impls;
 pub mod util;
 
+use hir::def_id::LocalDefId;
 use rustc_hir as hir;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{self, Const, ToPredicate, Ty, TyCtxt};
@@ -146,7 +147,7 @@ impl<'tcx, O> Obligation<'tcx, O> {
     pub fn misc(
         tcx: TyCtxt<'tcx>,
         span: Span,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         param_env: ty::ParamEnv<'tcx>,
         trait_ref: impl ToPredicate<'tcx, O>,
     ) -> Obligation<'tcx, O> {
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 379a76528f3..60b60edd2c8 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -16,7 +16,7 @@ use rustc_data_structures::parallel;
 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
 use rustc_errors::{ErrorGuaranteed, PResult};
 use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand};
-use rustc_hir::def_id::StableCrateId;
+use rustc_hir::def_id::{StableCrateId, LOCAL_CRATE};
 use rustc_lint::{BufferedEarlyLint, EarlyCheckNode, LintStore};
 use rustc_metadata::creader::CStore;
 use rustc_middle::arena::Arena;
@@ -30,7 +30,7 @@ use rustc_plugin_impl as plugin;
 use rustc_query_impl::{OnDiskCache, Queries as TcxQueries};
 use rustc_resolve::{Resolver, ResolverArenas};
 use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType};
-use rustc_session::cstore::{MetadataLoader, MetadataLoaderDyn, Untracked};
+use rustc_session::cstore::{CrateStoreDyn, MetadataLoader, MetadataLoaderDyn, Untracked};
 use rustc_session::output::filename_for_input;
 use rustc_session::search_paths::PathKind;
 use rustc_session::{Limit, Session};
@@ -47,7 +47,7 @@ use std::marker::PhantomPinned;
 use std::path::{Path, PathBuf};
 use std::pin::Pin;
 use std::rc::Rc;
-use std::sync::LazyLock;
+use std::sync::{Arc, LazyLock};
 use std::{env, fs, iter};
 
 pub fn parse<'a>(sess: &'a Session) -> PResult<'a, ast::Crate> {
@@ -548,7 +548,7 @@ fn escape_dep_env(symbol: Symbol) -> String {
 
 fn write_out_deps(
     sess: &Session,
-    boxed_resolver: &RefCell<BoxedResolver>,
+    cstore: &CrateStoreDyn,
     outputs: &OutputFilenames,
     out_filenames: &[PathBuf],
 ) {
@@ -600,20 +600,19 @@ fn write_out_deps(
                 }
             }
 
-            boxed_resolver.borrow_mut().access(|resolver| {
-                for cnum in resolver.cstore().crates_untracked() {
-                    let source = resolver.cstore().crate_source_untracked(cnum);
-                    if let Some((path, _)) = &source.dylib {
-                        files.push(escape_dep_filename(&path.display().to_string()));
-                    }
-                    if let Some((path, _)) = &source.rlib {
-                        files.push(escape_dep_filename(&path.display().to_string()));
-                    }
-                    if let Some((path, _)) = &source.rmeta {
-                        files.push(escape_dep_filename(&path.display().to_string()));
-                    }
+            let cstore = cstore.as_any().downcast_ref::<CStore>().unwrap();
+            for cnum in cstore.crates_untracked() {
+                let source = cstore.crate_source_untracked(cnum);
+                if let Some((path, _)) = &source.dylib {
+                    files.push(escape_dep_filename(&path.display().to_string()));
                 }
-            });
+                if let Some((path, _)) = &source.rlib {
+                    files.push(escape_dep_filename(&path.display().to_string()));
+                }
+                if let Some((path, _)) = &source.rmeta {
+                    files.push(escape_dep_filename(&path.display().to_string()));
+                }
+            }
         }
 
         let mut file = BufWriter::new(fs::File::create(&deps_filename)?);
@@ -661,13 +660,11 @@ fn write_out_deps(
     }
 }
 
-pub fn prepare_outputs(
-    sess: &Session,
-    krate: &ast::Crate,
-    boxed_resolver: &RefCell<BoxedResolver>,
-    crate_name: Symbol,
-) -> Result<OutputFilenames> {
+fn output_filenames(tcx: TyCtxt<'_>, (): ()) -> Arc<OutputFilenames> {
+    let sess = tcx.sess;
     let _timer = sess.timer("prepare_outputs");
+    let (_, krate) = &*tcx.resolver_for_lowering(()).borrow();
+    let crate_name = tcx.crate_name(LOCAL_CRATE);
 
     // FIXME: rustdoc passes &[] instead of &krate.attrs here
     let outputs = util::build_output_filenames(&krate.attrs, sess);
@@ -679,25 +676,21 @@ pub fn prepare_outputs(
     if let Some(ref input_path) = sess.io.input.opt_path() {
         if sess.opts.will_create_output_file() {
             if output_contains_path(&output_paths, input_path) {
-                let reported = sess.emit_err(InputFileWouldBeOverWritten { path: input_path });
-                return Err(reported);
+                sess.emit_fatal(InputFileWouldBeOverWritten { path: input_path });
             }
             if let Some(ref dir_path) = output_conflicts_with_dir(&output_paths) {
-                let reported =
-                    sess.emit_err(GeneratedFileConflictsWithDirectory { input_path, dir_path });
-                return Err(reported);
+                sess.emit_fatal(GeneratedFileConflictsWithDirectory { input_path, dir_path });
             }
         }
     }
 
     if let Some(ref dir) = sess.io.temps_dir {
         if fs::create_dir_all(dir).is_err() {
-            let reported = sess.emit_err(TempsDirError);
-            return Err(reported);
+            sess.emit_fatal(TempsDirError);
         }
     }
 
-    write_out_deps(sess, boxed_resolver, &outputs, &output_paths);
+    write_out_deps(sess, tcx.cstore_untracked(), &outputs, &output_paths);
 
     let only_dep_info = sess.opts.output_types.contains_key(&OutputType::DepInfo)
         && sess.opts.output_types.len() == 1;
@@ -705,19 +698,19 @@ pub fn prepare_outputs(
     if !only_dep_info {
         if let Some(ref dir) = sess.io.output_dir {
             if fs::create_dir_all(dir).is_err() {
-                let reported = sess.emit_err(OutDirError);
-                return Err(reported);
+                sess.emit_fatal(OutDirError);
             }
         }
     }
 
-    Ok(outputs)
+    outputs.into()
 }
 
 pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
     let providers = &mut Providers::default();
     providers.analysis = analysis;
     providers.hir_crate = rustc_ast_lowering::lower_to_hir;
+    providers.output_filenames = output_filenames;
     proc_macro_decls::provide(providers);
     rustc_const_eval::provide(providers);
     rustc_middle::hir::provide(providers);
@@ -900,6 +893,15 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
         }
     });
 
+    if tcx.sess.opts.unstable_opts.drop_tracking_mir {
+        tcx.hir().par_body_owners(|def_id| {
+            if let rustc_hir::def::DefKind::Generator = tcx.def_kind(def_id) {
+                tcx.ensure().mir_generator_witnesses(def_id);
+                tcx.ensure().check_generator_obligations(def_id);
+            }
+        });
+    }
+
     sess.time("layout_testing", || layout_test::test_layout(tcx));
 
     // Avoid overwhelming user with errors if borrow checking failed.
diff --git a/compiler/rustc_interface/src/queries.rs b/compiler/rustc_interface/src/queries.rs
index d5a49dd75be..4b0180741c1 100644
--- a/compiler/rustc_interface/src/queries.rs
+++ b/compiler/rustc_interface/src/queries.rs
@@ -65,7 +65,7 @@ impl<'a, T> std::ops::DerefMut for QueryResult<'a, T> {
 }
 
 impl<'a, 'tcx> QueryResult<'a, QueryContext<'tcx>> {
-    pub fn enter<T>(mut self, f: impl FnOnce(TyCtxt<'tcx>) -> T) -> T {
+    pub fn enter<T>(&mut self, f: impl FnOnce(TyCtxt<'tcx>) -> T) -> T {
         (*self.0).get_mut().enter(f)
     }
 }
@@ -212,8 +212,6 @@ impl<'tcx> Queries<'tcx> {
             let crate_name = *self.crate_name()?.borrow();
             let (krate, resolver, lint_store) = self.expansion()?.steal();
 
-            let outputs = passes::prepare_outputs(self.session(), &krate, &resolver, crate_name)?;
-
             let ty::ResolverOutputs {
                 untracked,
                 global_ctxt: untracked_resolutions,
@@ -237,7 +235,6 @@ impl<'tcx> Queries<'tcx> {
                     tcx.arena.alloc(Steal::new((untracked_resolver_for_lowering, krate))),
                 );
                 feed.resolutions(tcx.arena.alloc(untracked_resolutions));
-                feed.output_filenames(tcx.arena.alloc(std::sync::Arc::new(outputs)));
                 feed.features_query(tcx.sess.features_untracked());
                 let feed = tcx.feed_local_crate();
                 feed.crate_name(crate_name);
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index f94bc4d4c66..52a4e0e7418 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -802,6 +802,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(teach, true);
     tracked!(thinlto, Some(true));
     tracked!(thir_unsafeck, true);
+    tracked!(tiny_const_eval_limit, true);
     tracked!(tls_model, Some(TlsModel::GeneralDynamic));
     tracked!(trait_solver, TraitSolver::Chalk);
     tracked!(translate_remapped_path_to_local_path, false);
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index fe188162cf8..8361c81f0ef 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -56,9 +56,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
 use rustc_hir::intravisit::FnKind as HirFnKind;
-use rustc_hir::{
-    Body, FnDecl, ForeignItemKind, GenericParamKind, HirId, Node, PatKind, PredicateOrigin,
-};
+use rustc_hir::{Body, FnDecl, ForeignItemKind, GenericParamKind, Node, PatKind, PredicateOrigin};
 use rustc_index::vec::Idx;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::layout::{LayoutError, LayoutOf};
@@ -583,12 +581,13 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
 
     fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
         // If the method is an impl for a trait, don't doc.
-        if method_context(cx, impl_item.hir_id()) == MethodLateContext::TraitImpl {
+        let context = method_context(cx, impl_item.owner_id.def_id);
+        if context == MethodLateContext::TraitImpl {
             return;
         }
 
         // If the method is an impl for an item with docs_hidden, don't doc.
-        if method_context(cx, impl_item.hir_id()) == MethodLateContext::PlainImpl {
+        if context == MethodLateContext::PlainImpl {
             let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id());
             let impl_ty = cx.tcx.type_of(parent);
             let outerdef = match impl_ty.kind() {
@@ -732,7 +731,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
             cx.tcx,
             param_env,
             ty,
-            traits::ObligationCause::misc(item.span, item.hir_id()),
+            traits::ObligationCause::misc(item.span, item.owner_id.def_id),
         )
         .is_ok()
         {
@@ -1296,19 +1295,18 @@ impl<'tcx> LateLintPass<'tcx> for UngatedAsyncFnTrackCaller {
         _: &'tcx FnDecl<'_>,
         _: &'tcx Body<'_>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
         if fn_kind.asyncness() == IsAsync::Async
             && !cx.tcx.features().closure_track_caller
-            && let attrs = cx.tcx.hir().attrs(hir_id)
             // Now, check if the function has the `#[track_caller]` attribute
-            && let Some(attr) = attrs.iter().find(|attr| attr.has_name(sym::track_caller))
-            {
-                cx.emit_spanned_lint(UNGATED_ASYNC_FN_TRACK_CALLER, attr.span, BuiltinUngatedAsyncFnTrackCaller {
-                    label: span,
-                    parse_sess: &cx.tcx.sess.parse_sess,
-                });
-            }
+            && let Some(attr) = cx.tcx.get_attr(def_id.to_def_id(), sym::track_caller)
+        {
+            cx.emit_spanned_lint(UNGATED_ASYNC_FN_TRACK_CALLER, attr.span, BuiltinUngatedAsyncFnTrackCaller {
+                label: span,
+                parse_sess: &cx.tcx.sess.parse_sess,
+            });
+        }
     }
 }
 
@@ -2175,13 +2173,31 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
                     dropped_predicate_count += 1;
                 }
 
-                if drop_predicate && !in_where_clause {
-                    lint_spans.push(predicate_span);
-                } else if drop_predicate && i + 1 < num_predicates {
-                    // If all the bounds on a predicate were inferable and there are
-                    // further predicates, we want to eat the trailing comma.
-                    let next_predicate_span = hir_generics.predicates[i + 1].span();
-                    where_lint_spans.push(predicate_span.to(next_predicate_span.shrink_to_lo()));
+                if drop_predicate {
+                    if !in_where_clause {
+                        lint_spans.push(predicate_span);
+                    } else if predicate_span.from_expansion() {
+                        // Don't try to extend the span if it comes from a macro expansion.
+                        where_lint_spans.push(predicate_span);
+                    } else if i + 1 < num_predicates {
+                        // If all the bounds on a predicate were inferable and there are
+                        // further predicates, we want to eat the trailing comma.
+                        let next_predicate_span = hir_generics.predicates[i + 1].span();
+                        if next_predicate_span.from_expansion() {
+                            where_lint_spans.push(predicate_span);
+                        } else {
+                            where_lint_spans
+                                .push(predicate_span.to(next_predicate_span.shrink_to_lo()));
+                        }
+                    } else {
+                        // Eat the optional trailing comma after the last predicate.
+                        let where_span = hir_generics.where_clause_span;
+                        if where_span.from_expansion() {
+                            where_lint_spans.push(predicate_span);
+                        } else {
+                            where_lint_spans.push(predicate_span.to(where_span.shrink_to_hi()));
+                        }
+                    }
                 } else {
                     where_lint_spans.extend(self.consolidate_outlives_bound_spans(
                         predicate_span.shrink_to_lo(),
@@ -2225,6 +2241,11 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
                     Applicability::MaybeIncorrect
                 };
 
+                // Due to macros, there might be several predicates with the same span
+                // and we only want to suggest removing them once.
+                lint_spans.sort_unstable();
+                lint_spans.dedup();
+
                 cx.emit_spanned_lint(
                     EXPLICIT_OUTLIVES_REQUIREMENTS,
                     lint_spans.clone(),
@@ -2661,7 +2682,7 @@ pub struct ClashingExternDeclarations {
     /// the symbol should be reported as a clashing declaration.
     // FIXME: Technically, we could just store a &'tcx str here without issue; however, the
     // `impl_lint_pass` macro doesn't currently support lints parametric over a lifetime.
-    seen_decls: FxHashMap<Symbol, HirId>,
+    seen_decls: FxHashMap<Symbol, hir::OwnerId>,
 }
 
 /// Differentiate between whether the name for an extern decl came from the link_name attribute or
@@ -2687,19 +2708,20 @@ impl ClashingExternDeclarations {
     pub(crate) fn new() -> Self {
         ClashingExternDeclarations { seen_decls: FxHashMap::default() }
     }
+
     /// Insert a new foreign item into the seen set. If a symbol with the same name already exists
     /// for the item, return its HirId without updating the set.
-    fn insert(&mut self, tcx: TyCtxt<'_>, fi: &hir::ForeignItem<'_>) -> Option<HirId> {
+    fn insert(&mut self, tcx: TyCtxt<'_>, fi: &hir::ForeignItem<'_>) -> Option<hir::OwnerId> {
         let did = fi.owner_id.to_def_id();
         let instance = Instance::new(did, ty::List::identity_for_item(tcx, did));
         let name = Symbol::intern(tcx.symbol_name(instance).name);
-        if let Some(&hir_id) = self.seen_decls.get(&name) {
+        if let Some(&existing_id) = self.seen_decls.get(&name) {
             // Avoid updating the map with the new entry when we do find a collision. We want to
             // make sure we're always pointing to the first definition as the previous declaration.
             // This lets us avoid emitting "knock-on" diagnostics.
-            Some(hir_id)
+            Some(existing_id)
         } else {
-            self.seen_decls.insert(name, fi.hir_id())
+            self.seen_decls.insert(name, fi.owner_id)
         }
     }
 
@@ -2926,16 +2948,16 @@ impl ClashingExternDeclarations {
 impl_lint_pass!(ClashingExternDeclarations => [CLASHING_EXTERN_DECLARATIONS]);
 
 impl<'tcx> LateLintPass<'tcx> for ClashingExternDeclarations {
+    #[instrument(level = "trace", skip(self, cx))]
     fn check_foreign_item(&mut self, cx: &LateContext<'tcx>, this_fi: &hir::ForeignItem<'_>) {
-        trace!("ClashingExternDeclarations: check_foreign_item: {:?}", this_fi);
         if let ForeignItemKind::Fn(..) = this_fi.kind {
             let tcx = cx.tcx;
-            if let Some(existing_hid) = self.insert(tcx, this_fi) {
-                let existing_decl_ty = tcx.type_of(tcx.hir().local_def_id(existing_hid));
+            if let Some(existing_did) = self.insert(tcx, this_fi) {
+                let existing_decl_ty = tcx.type_of(existing_did);
                 let this_decl_ty = tcx.type_of(this_fi.owner_id);
                 debug!(
                     "ClashingExternDeclarations: Comparing existing {:?}: {:?} to this {:?}: {:?}",
-                    existing_hid, existing_decl_ty, this_fi.owner_id, this_decl_ty
+                    existing_did, existing_decl_ty, this_fi.owner_id, this_decl_ty
                 );
                 // Check that the declarations match.
                 if !Self::structurally_same_type(
@@ -2944,7 +2966,7 @@ impl<'tcx> LateLintPass<'tcx> for ClashingExternDeclarations {
                     this_decl_ty,
                     CItemKind::Declaration,
                 ) {
-                    let orig_fi = tcx.hir().expect_foreign_item(existing_hid.expect_owner());
+                    let orig_fi = tcx.hir().expect_foreign_item(existing_did);
                     let orig = Self::name_of_extern_decl(tcx, orig_fi);
 
                     // We want to ensure that we use spans for both decls that include where the
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index 8046cc21cea..d1d4bb37528 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -882,6 +882,9 @@ pub trait LintContext: Sized {
                         );
                     }
                 }
+                BuiltinLintDiagnostics::ByteSliceInPackedStructWithDerive => {
+                    db.help("consider implementing the trait by hand, or remove the `packed` attribute");
+                }
             }
             // Rewrap `db`, and pass control to the user.
             decorate(db)
diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
index 5219992ee94..1add352e0c4 100644
--- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs
+++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
@@ -139,9 +139,10 @@ fn suggest_question_mark<'tcx>(
 
     let ty = substs.type_at(0);
     let infcx = cx.tcx.infer_ctxt().build();
+    let body_def_id = cx.tcx.hir().body_owner_def_id(body_id);
     let cause = ObligationCause::new(
         span,
-        body_id.hir_id,
+        body_def_id,
         rustc_infer::traits::ObligationCauseCode::MiscObligation,
     );
     let errors = rustc_trait_selection::traits::fully_solve_bound(
diff --git a/compiler/rustc_lint/src/late.rs b/compiler/rustc_lint/src/late.rs
index b2a2656746e..b42878a02ee 100644
--- a/compiler/rustc_lint/src/late.rs
+++ b/compiler/rustc_lint/src/late.rs
@@ -66,13 +66,12 @@ impl<'tcx, T: LateLintPass<'tcx>> LateContextAndPass<'tcx, T> {
         self.context.last_node_with_lint_attrs = prev;
     }
 
-    fn with_param_env<F>(&mut self, id: hir::HirId, f: F)
+    fn with_param_env<F>(&mut self, id: hir::OwnerId, f: F)
     where
         F: FnOnce(&mut Self),
     {
         let old_param_env = self.context.param_env;
-        self.context.param_env =
-            self.context.tcx.param_env(self.context.tcx.hir().local_def_id(id));
+        self.context.param_env = self.context.tcx.param_env(id);
         f(self);
         self.context.param_env = old_param_env;
     }
@@ -132,7 +131,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         let old_cached_typeck_results = self.context.cached_typeck_results.take();
         let old_enclosing_body = self.context.enclosing_body.take();
         self.with_lint_attrs(it.hir_id(), |cx| {
-            cx.with_param_env(it.hir_id(), |cx| {
+            cx.with_param_env(it.owner_id, |cx| {
                 lint_callback!(cx, check_item, it);
                 hir_visit::walk_item(cx, it);
                 lint_callback!(cx, check_item_post, it);
@@ -145,7 +144,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
 
     fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem<'tcx>) {
         self.with_lint_attrs(it.hir_id(), |cx| {
-            cx.with_param_env(it.hir_id(), |cx| {
+            cx.with_param_env(it.owner_id, |cx| {
                 lint_callback!(cx, check_foreign_item, it);
                 hir_visit::walk_foreign_item(cx, it);
             });
@@ -180,7 +179,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         decl: &'tcx hir::FnDecl<'tcx>,
         body_id: hir::BodyId,
         span: Span,
-        id: hir::HirId,
+        id: LocalDefId,
     ) {
         // Wrap in typeck results here, not just in visit_nested_body,
         // in order for `check_fn` to be able to use them.
@@ -268,7 +267,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         let generics = self.context.generics.take();
         self.context.generics = Some(&trait_item.generics);
         self.with_lint_attrs(trait_item.hir_id(), |cx| {
-            cx.with_param_env(trait_item.hir_id(), |cx| {
+            cx.with_param_env(trait_item.owner_id, |cx| {
                 lint_callback!(cx, check_trait_item, trait_item);
                 hir_visit::walk_trait_item(cx, trait_item);
             });
@@ -280,7 +279,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         let generics = self.context.generics.take();
         self.context.generics = Some(&impl_item.generics);
         self.with_lint_attrs(impl_item.hir_id(), |cx| {
-            cx.with_param_env(impl_item.hir_id(), |cx| {
+            cx.with_param_env(impl_item.owner_id, |cx| {
                 lint_callback!(cx, check_impl_item, impl_item);
                 hir_visit::walk_impl_item(cx, impl_item);
                 lint_callback!(cx, check_impl_item_post, impl_item);
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index d6be4da0328..ba15dbd86cf 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -64,6 +64,7 @@ mod let_underscore;
 mod levels;
 mod lints;
 mod methods;
+mod multiple_supertrait_upcastable;
 mod non_ascii_idents;
 mod non_fmt_panic;
 mod nonstandard_style;
@@ -98,6 +99,7 @@ use hidden_unicode_codepoints::*;
 use internal::*;
 use let_underscore::*;
 use methods::*;
+use multiple_supertrait_upcastable::*;
 use non_ascii_idents::*;
 use non_fmt_panic::NonPanicFmt;
 use nonstandard_style::*;
@@ -232,6 +234,7 @@ late_lint_methods!(
             InvalidAtomicOrdering: InvalidAtomicOrdering,
             NamedAsmLabels: NamedAsmLabels,
             OpaqueHiddenInferredBound: OpaqueHiddenInferredBound,
+            MultipleSupertraitUpcastable: MultipleSupertraitUpcastable,
         ]
     ]
 );
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index c997d8945d1..0c1019545f3 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -917,6 +917,13 @@ pub struct CStringPtr {
     pub unwrap: Span,
 }
 
+// multiple_supertrait_upcastable.rs
+#[derive(LintDiagnostic)]
+#[diag(lint_multple_supertrait_upcastable)]
+pub struct MultipleSupertraitUpcastable {
+    pub ident: Ident,
+}
+
 // non_ascii_idents.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_identifier_non_ascii_char)]
diff --git a/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs b/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs
new file mode 100644
index 00000000000..c2ed0e19f40
--- /dev/null
+++ b/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs
@@ -0,0 +1,60 @@
+use crate::{LateContext, LateLintPass, LintContext};
+
+use rustc_hir as hir;
+use rustc_span::sym;
+
+declare_lint! {
+    /// The `multiple_supertrait_upcastable` lint detects when an object-safe trait has multiple
+    /// supertraits.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// trait A {}
+    /// trait B {}
+    ///
+    /// #[warn(multiple_supertrait_upcastable)]
+    /// trait C: A + B {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// To support upcasting with multiple supertraits, we need to store multiple vtables and this
+    /// can result in extra space overhead, even if no code actually uses upcasting.
+    /// This lint allows users to identify when such scenarios occur and to decide whether the
+    /// additional overhead is justified.
+    pub MULTIPLE_SUPERTRAIT_UPCASTABLE,
+    Allow,
+    "detect when an object-safe trait has multiple supertraits",
+    @feature_gate = sym::multiple_supertrait_upcastable;
+}
+
+declare_lint_pass!(MultipleSupertraitUpcastable => [MULTIPLE_SUPERTRAIT_UPCASTABLE]);
+
+impl<'tcx> LateLintPass<'tcx> for MultipleSupertraitUpcastable {
+    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
+        let def_id = item.owner_id.to_def_id();
+        // NOTE(nbdd0121): use `object_safety_violations` instead of `check_is_object_safe` because
+        // the latter will report `where_clause_object_safety` lint.
+        if let hir::ItemKind::Trait(_, _, _, _, _) = item.kind
+            && cx.tcx.object_safety_violations(def_id).is_empty()
+        {
+            let direct_super_traits_iter = cx.tcx
+                    .super_predicates_of(def_id)
+                    .predicates
+                    .into_iter()
+                    .filter_map(|(pred, _)| pred.to_opt_poly_trait_pred());
+            if direct_super_traits_iter.count() > 1 {
+                cx.emit_spanned_lint(
+                    MULTIPLE_SUPERTRAIT_UPCASTABLE,
+                    cx.tcx.def_span(def_id),
+                    crate::lints::MultipleSupertraitUpcastable {
+                        ident: item.ident
+                    },
+                );
+            }
+        }
+    }
+}
diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs
index 74d234fabea..71e2e66bdeb 100644
--- a/compiler/rustc_lint/src/nonstandard_style.rs
+++ b/compiler/rustc_lint/src/nonstandard_style.rs
@@ -10,8 +10,9 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{GenericParamKind, PatKind};
 use rustc_middle::ty;
-use rustc_span::symbol::sym;
-use rustc_span::{symbol::Ident, BytePos, Span};
+use rustc_span::def_id::LocalDefId;
+use rustc_span::symbol::{sym, Ident};
+use rustc_span::{BytePos, Span};
 use rustc_target::spec::abi::Abi;
 
 #[derive(PartialEq)]
@@ -21,9 +22,8 @@ pub enum MethodLateContext {
     PlainImpl,
 }
 
-pub fn method_context(cx: &LateContext<'_>, id: hir::HirId) -> MethodLateContext {
-    let def_id = cx.tcx.hir().local_def_id(id);
-    let item = cx.tcx.associated_item(def_id);
+pub fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext {
+    let item = cx.tcx.associated_item(id);
     match item.container {
         ty::TraitContainer => MethodLateContext::TraitAutoImpl,
         ty::ImplContainer => match cx.tcx.impl_trait_ref(item.container_id(cx.tcx)) {
@@ -379,13 +379,13 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
         _: &hir::FnDecl<'_>,
         _: &hir::Body<'_>,
         _: Span,
-        id: hir::HirId,
+        id: LocalDefId,
     ) {
-        let attrs = cx.tcx.hir().attrs(id);
         match &fk {
             FnKind::Method(ident, sig, ..) => match method_context(cx, id) {
                 MethodLateContext::PlainImpl => {
-                    if sig.header.abi != Abi::Rust && cx.sess().contains_name(attrs, sym::no_mangle)
+                    if sig.header.abi != Abi::Rust
+                        && cx.tcx.has_attr(id.to_def_id(), sym::no_mangle)
                     {
                         return;
                     }
@@ -398,7 +398,7 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
             },
             FnKind::ItemFn(ident, _, header) => {
                 // Skip foreign-ABI #[no_mangle] functions (Issue #31924)
-                if header.abi != Abi::Rust && cx.sess().contains_name(attrs, sym::no_mangle) {
+                if header.abi != Abi::Rust && cx.tcx.has_attr(id.to_def_id(), sym::no_mangle) {
                     return;
                 }
                 self.check_snake_case(cx, "function", ident);
diff --git a/compiler/rustc_lint/src/passes.rs b/compiler/rustc_lint/src/passes.rs
index 0bf01c4e567..16964565b01 100644
--- a/compiler/rustc_lint/src/passes.rs
+++ b/compiler/rustc_lint/src/passes.rs
@@ -4,6 +4,7 @@ use rustc_ast as ast;
 use rustc_hir as hir;
 use rustc_session::lint::builtin::HardwiredLints;
 use rustc_session::lint::LintPass;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
 
@@ -36,7 +37,7 @@ macro_rules! late_lint_methods {
                 b: &'tcx hir::FnDecl<'tcx>,
                 c: &'tcx hir::Body<'tcx>,
                 d: Span,
-                e: hir::HirId);
+                e: LocalDefId);
             fn check_trait_item(a: &'tcx hir::TraitItem<'tcx>);
             fn check_impl_item(a: &'tcx hir::ImplItem<'tcx>);
             fn check_impl_item_post(a: &'tcx hir::ImplItem<'tcx>);
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index be47a3e238c..b0a5d3674ad 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -14,6 +14,7 @@ use rustc_hir::{is_range_literal, Expr, ExprKind, Node};
 use rustc_middle::ty::layout::{IntegerExt, LayoutOf, SizeSkeleton};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AdtKind, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map;
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
@@ -1107,6 +1108,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Placeholder(..)
             | ty::FnDef(..) => bug!("unexpected type in foreign function: {:?}", ty),
         }
@@ -1223,9 +1225,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
         }
     }
 
-    fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl<'_>) {
-        let def_id = self.cx.tcx.hir().local_def_id(id);
-        let sig = self.cx.tcx.fn_sig(def_id);
+    fn check_foreign_fn(&mut self, def_id: LocalDefId, decl: &hir::FnDecl<'_>) {
+        let sig = self.cx.tcx.fn_sig(def_id).subst_identity();
         let sig = self.cx.tcx.erase_late_bound_regions(sig);
 
         for (input_ty, input_hir) in iter::zip(sig.inputs(), decl.inputs) {
@@ -1238,9 +1239,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
         }
     }
 
-    fn check_foreign_static(&mut self, id: hir::HirId, span: Span) {
-        let def_id = self.cx.tcx.hir().local_def_id(id);
-        let ty = self.cx.tcx.type_of(def_id);
+    fn check_foreign_static(&mut self, id: hir::OwnerId, span: Span) {
+        let ty = self.cx.tcx.type_of(id);
         self.check_type_for_ffi_and_report_errors(span, ty, true, false);
     }
 
@@ -1260,10 +1260,10 @@ impl<'tcx> LateLintPass<'tcx> for ImproperCTypesDeclarations {
         if !vis.is_internal_abi(abi) {
             match it.kind {
                 hir::ForeignItemKind::Fn(ref decl, _, _) => {
-                    vis.check_foreign_fn(it.hir_id(), decl);
+                    vis.check_foreign_fn(it.owner_id.def_id, decl);
                 }
                 hir::ForeignItemKind::Static(ref ty, _) => {
-                    vis.check_foreign_static(it.hir_id(), ty.span);
+                    vis.check_foreign_static(it.owner_id, ty.span);
                 }
                 hir::ForeignItemKind::Type => (),
             }
@@ -1279,7 +1279,7 @@ impl<'tcx> LateLintPass<'tcx> for ImproperCTypesDefinitions {
         decl: &'tcx hir::FnDecl<'_>,
         _: &'tcx hir::Body<'_>,
         _: Span,
-        hir_id: hir::HirId,
+        id: LocalDefId,
     ) {
         use hir::intravisit::FnKind;
 
@@ -1291,7 +1291,7 @@ impl<'tcx> LateLintPass<'tcx> for ImproperCTypesDefinitions {
 
         let mut vis = ImproperCTypesVisitor { cx, mode: CItemKind::Definition };
         if !vis.is_internal_abi(abi) {
-            vis.check_foreign_fn(hir_id, decl);
+            vis.check_foreign_fn(id, decl);
         }
     }
 }
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index b6481d70bc8..d731c10f46e 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -3381,6 +3381,7 @@ declare_lint_pass! {
         REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS,
         NAMED_ARGUMENTS_USED_POSITIONALLY,
         IMPLIED_BOUNDS_ENTAILMENT,
+        BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
     ]
 }
 
@@ -3531,9 +3532,15 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// Previously, there were very like checks being performed on `#[doc(..)]`
-    /// unlike the other attributes. It'll now catch all the issues that it
-    /// silently ignored previously.
+    /// Previously, incorrect usage of the `#[doc(..)]` attribute was not
+    /// being validated. Usually these should be rejected as a hard error,
+    /// but this lint was introduced to avoid breaking any existing
+    /// crates which included them.
+    ///
+    /// This is a [future-incompatible] lint to transition this to a hard
+    /// error in the future. See [issue #82730] for more details.
+    ///
+    /// [issue #82730]: https://github.com/rust-lang/rust/issues/82730
     pub INVALID_DOC_ATTRIBUTES,
     Warn,
     "detects invalid `#[doc(...)]` attributes",
@@ -4109,3 +4116,35 @@ declare_lint! {
         reason: FutureIncompatibilityReason::FutureReleaseErrorReportNow,
     };
 }
+
+declare_lint! {
+    /// The `byte_slice_in_packed_struct_with_derive` lint detects cases where a byte slice field
+    /// (`[u8]`) is used in a `packed` struct that derives one or more built-in traits.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// #[repr(packed)]
+    /// #[derive(Hash)]
+    /// struct FlexZeroSlice {
+    ///     width: u8,
+    ///     data: [u8],
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// This was previously accepted but is being phased out, because fields in packed structs are
+    /// now required to implement `Copy` for `derive` to work. Byte slices are a temporary
+    /// exception because certain crates depended on them.
+    pub BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
+    Warn,
+    "`[u8]` slice used in a packed struct with `derive`",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #107457 <https://github.com/rust-lang/rust/issues/107457>",
+        reason: FutureIncompatibilityReason::FutureReleaseErrorReportNow,
+    };
+    report_in_external_macro
+}
diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs
index 7054d1e9f10..6efbf5ce9ee 100644
--- a/compiler/rustc_lint_defs/src/lib.rs
+++ b/compiler/rustc_lint_defs/src/lib.rs
@@ -521,6 +521,7 @@ pub enum BuiltinLintDiagnostics {
         /// Indicates if the named argument is used as a width/precision for formatting
         is_formatting_arg: bool,
     },
+    ByteSliceInPackedStructWithDerive,
 }
 
 /// Lints that are buffered up early on in the `Session` before the
diff --git a/compiler/rustc_macros/src/diagnostics/fluent.rs b/compiler/rustc_macros/src/diagnostics/fluent.rs
index 32338f9dfc5..08098c9bb2a 100644
--- a/compiler/rustc_macros/src/diagnostics/fluent.rs
+++ b/compiler/rustc_macros/src/diagnostics/fluent.rs
@@ -4,7 +4,10 @@ use annotate_snippets::{
 };
 use fluent_bundle::{FluentBundle, FluentError, FluentResource};
 use fluent_syntax::{
-    ast::{Attribute, Entry, Identifier, Message},
+    ast::{
+        Attribute, Entry, Expression, Identifier, InlineExpression, Message, Pattern,
+        PatternElement,
+    },
     parser::ParserError,
 };
 use proc_macro::{Diagnostic, Level, Span};
@@ -185,9 +188,12 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
         };
 
         let mut constants = TokenStream::new();
+        let mut messagerefs = Vec::new();
         for entry in resource.entries() {
             let span = res.krate.span();
-            if let Entry::Message(Message { id: Identifier { name }, attributes, .. }) = entry {
+            if let Entry::Message(Message { id: Identifier { name }, attributes, value, .. }) =
+                entry
+            {
                 let _ = previous_defns.entry(name.to_string()).or_insert(path_span);
 
                 if name.contains('-') {
@@ -200,6 +206,18 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                     .emit();
                 }
 
+                if let Some(Pattern { elements }) = value {
+                    for elt in elements {
+                        if let PatternElement::Placeable {
+                            expression:
+                                Expression::Inline(InlineExpression::MessageReference { id, .. }),
+                        } = elt
+                        {
+                            messagerefs.push((id.name, *name));
+                        }
+                    }
+                }
+
                 // Require that the message name starts with the crate name
                 // `hir_typeck_foo_bar` (in `hir_typeck.ftl`)
                 // `const_eval_baz` (in `const_eval.ftl`)
@@ -258,6 +276,18 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
             }
         }
 
+        for (mref, name) in messagerefs.into_iter() {
+            if !previous_defns.contains_key(mref) {
+                Diagnostic::spanned(
+                    path_span,
+                    Level::Error,
+                    format!("referenced message `{mref}` does not exist (in message `{name}`)"),
+                )
+                .help(&format!("you may have meant to use a variable reference (`{{${mref}}}`)"))
+                .emit();
+            }
+        }
+
         if let Err(errs) = bundle.add_resource(resource) {
             for e in errs {
                 match e {
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 44da3fbe300..bb2dd290c6d 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -985,7 +985,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         let vis = self.get_visibility(id);
         let span = self.get_span(id, sess);
         let macro_rules = match kind {
-            DefKind::Macro(..) => self.root.tables.macro_rules.get(self, id).is_some(),
+            DefKind::Macro(..) => self.root.tables.is_macro_rules.get(self, id),
             _ => false,
         };
 
@@ -1283,7 +1283,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     fn get_macro(self, id: DefIndex, sess: &Session) -> ast::MacroDef {
         match self.def_kind(id) {
             DefKind::Macro(_) => {
-                let macro_rules = self.root.tables.macro_rules.get(self, id).is_some();
+                let macro_rules = self.root.tables.is_macro_rules.get(self, id);
                 let body =
                     self.root.tables.macro_definition.get(self, id).unwrap().decode((self, sess));
                 ast::MacroDef { macro_rules, body: ast::ptr::P(body) }
@@ -1595,11 +1595,11 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     fn get_attr_flags(self, index: DefIndex) -> AttrFlags {
-        self.root.tables.attr_flags.get(self, index).unwrap_or(AttrFlags::empty())
+        self.root.tables.attr_flags.get(self, index)
     }
 
     fn get_is_intrinsic(self, index: DefIndex) -> bool {
-        self.root.tables.is_intrinsic.get(self, index).is_some()
+        self.root.tables.is_intrinsic.get(self, index)
     }
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 2fa645cd9e3..9b1401f4a44 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -202,6 +202,7 @@ provide! { tcx, def_id, other, cdata,
     thir_abstract_const => { table }
     optimized_mir => { table }
     mir_for_ctfe => { table }
+    mir_generator_witnesses => { table }
     promoted_mir => { table }
     def_span => { table }
     def_ident_span => { table }
@@ -226,12 +227,7 @@ provide! { tcx, def_id, other, cdata,
     deduced_param_attrs => { table }
     is_type_alias_impl_trait => {
         debug_assert_eq!(tcx.def_kind(def_id), DefKind::OpaqueTy);
-        cdata
-            .root
-            .tables
-            .is_type_alias_impl_trait
-            .get(cdata, def_id.index)
-            .is_some()
+        cdata.root.tables.is_type_alias_impl_trait.get(cdata, def_id.index)
     }
     collect_return_position_impl_trait_in_trait_tys => {
         Ok(cdata
@@ -637,6 +633,12 @@ impl CStore {
             .get_attr_flags(def_id.index)
             .contains(AttrFlags::MAY_HAVE_DOC_LINKS)
     }
+
+    pub fn is_doc_hidden_untracked(&self, def_id: DefId) -> bool {
+        self.get_crate_data(def_id.krate)
+            .get_attr_flags(def_id.index)
+            .contains(AttrFlags::IS_DOC_HIDDEN)
+    }
 }
 
 impl CrateStore for CStore {
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 2ecaa33d4d3..29507ff3a86 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -3,6 +3,7 @@ use crate::rmeta::def_path_hash_map::DefPathHashMapRef;
 use crate::rmeta::table::TableBuilder;
 use crate::rmeta::*;
 
+use rustc_ast::util::comments;
 use rustc_ast::Attribute;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
@@ -38,7 +39,6 @@ use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{
     self, DebuggerVisualizerFile, ExternalSource, FileName, SourceFile, Span, SyntaxContext,
 };
-use rustc_target::abi::VariantIdx;
 use std::borrow::Borrow;
 use std::collections::hash_map::Entry;
 use std::hash::Hash;
@@ -483,7 +483,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         self.lazy(DefPathHashMapRef::BorrowedFromTcx(self.tcx.def_path_hash_to_def_index_map()))
     }
 
-    fn encode_source_map(&mut self) -> LazyTable<u32, LazyValue<rustc_span::SourceFile>> {
+    fn encode_source_map(&mut self) -> LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>> {
         let source_map = self.tcx.sess.source_map();
         let all_source_files = source_map.files();
 
@@ -760,36 +760,54 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     }
 }
 
+struct AnalyzeAttrState {
+    is_exported: bool,
+    may_have_doc_links: bool,
+    is_doc_hidden: bool,
+}
+
 /// Returns whether an attribute needs to be recorded in metadata, that is, if it's usable and
 /// useful in downstream crates. Local-only attributes are an obvious example, but some
 /// rustdoc-specific attributes can equally be of use while documenting the current crate only.
 ///
 /// Removing these superfluous attributes speeds up compilation by making the metadata smaller.
 ///
-/// Note: the `is_def_id_public` parameter is used to cache whether the given `DefId` has a public
+/// Note: the `is_exported` parameter is used to cache whether the given `DefId` has a public
 /// visibility: this is a piece of data that can be computed once per defid, and not once per
 /// attribute. Some attributes would only be usable downstream if they are public.
 #[inline]
-fn should_encode_attr(
-    tcx: TyCtxt<'_>,
-    attr: &Attribute,
-    def_id: LocalDefId,
-    is_def_id_public: &mut Option<bool>,
-) -> bool {
+fn analyze_attr(attr: &Attribute, state: &mut AnalyzeAttrState) -> bool {
+    let mut should_encode = false;
     if rustc_feature::is_builtin_only_local(attr.name_or_empty()) {
         // Attributes marked local-only don't need to be encoded for downstream crates.
-        false
-    } else if attr.doc_str().is_some() {
-        // We keep all public doc comments because they might be "imported" into downstream crates
-        // if they use `#[doc(inline)]` to copy an item's documentation into their own.
-        *is_def_id_public.get_or_insert_with(|| tcx.effective_visibilities(()).is_exported(def_id))
+    } else if let Some(s) = attr.doc_str() {
+        // We keep all doc comments reachable to rustdoc because they might be "imported" into
+        // downstream crates if they use `#[doc(inline)]` to copy an item's documentation into
+        // their own.
+        if state.is_exported {
+            should_encode = true;
+            if comments::may_have_doc_links(s.as_str()) {
+                state.may_have_doc_links = true;
+            }
+        }
     } else if attr.has_name(sym::doc) {
-        // If this is a `doc` attribute, and it's marked `inline` (as in `#[doc(inline)]`), we can
-        // remove it. It won't be inlinable in downstream crates.
-        attr.meta_item_list().map(|l| l.iter().any(|l| !l.has_name(sym::inline))).unwrap_or(false)
+        // If this is a `doc` attribute that doesn't have anything except maybe `inline` (as in
+        // `#[doc(inline)]`), then we can remove it. It won't be inlinable in downstream crates.
+        if let Some(item_list) = attr.meta_item_list() {
+            for item in item_list {
+                if !item.has_name(sym::inline) {
+                    should_encode = true;
+                    if item.has_name(sym::hidden) {
+                        state.is_doc_hidden = true;
+                        break;
+                    }
+                }
+            }
+        }
     } else {
-        true
+        should_encode = true;
     }
+    should_encode
 }
 
 fn should_encode_visibility(def_kind: DefKind) -> bool {
@@ -1094,7 +1112,7 @@ fn should_encode_trait_impl_trait_tys(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     // of the trait fn to look for any RPITITs, but that's kinda doing a lot
     // of work. We can probably remove this when we refactor RPITITs to be
     // associated types.
-    tcx.fn_sig(trait_item_def_id).skip_binder().output().walk().any(|arg| {
+    tcx.fn_sig(trait_item_def_id).subst_identity().skip_binder().output().walk().any(|arg| {
         if let ty::GenericArgKind::Type(ty) = arg.unpack()
             && let ty::Alias(ty::Projection, data) = ty.kind()
             && tcx.def_kind(data.def_id) == DefKind::ImplTraitPlaceholder
@@ -1109,28 +1127,28 @@ fn should_encode_trait_impl_trait_tys(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     fn encode_attrs(&mut self, def_id: LocalDefId) {
         let tcx = self.tcx;
-        let mut is_public: Option<bool> = None;
-
-        let hir_attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(def_id));
-        let mut attrs = hir_attrs
+        let mut state = AnalyzeAttrState {
+            is_exported: tcx.effective_visibilities(()).is_exported(def_id),
+            may_have_doc_links: false,
+            is_doc_hidden: false,
+        };
+        let attr_iter = tcx
+            .hir()
+            .attrs(tcx.hir().local_def_id_to_hir_id(def_id))
             .iter()
-            .filter(move |attr| should_encode_attr(tcx, attr, def_id, &mut is_public));
+            .filter(|attr| analyze_attr(attr, &mut state));
+
+        record_array!(self.tables.attributes[def_id.to_def_id()] <- attr_iter);
 
-        record_array!(self.tables.attributes[def_id.to_def_id()] <- attrs.clone());
         let mut attr_flags = AttrFlags::empty();
-        if attrs.any(|attr| attr.may_have_doc_links()) {
+        if state.may_have_doc_links {
             attr_flags |= AttrFlags::MAY_HAVE_DOC_LINKS;
         }
-        if hir_attrs
-            .iter()
-            .filter(|attr| attr.has_name(sym::doc))
-            .filter_map(|attr| attr.meta_item_list())
-            .any(|items| items.iter().any(|item| item.has_name(sym::hidden)))
-        {
+        if state.is_doc_hidden {
             attr_flags |= AttrFlags::IS_DOC_HIDDEN;
         }
         if !attr_flags.is_empty() {
-            self.tables.attr_flags.set(def_id.local_def_index, attr_flags);
+            self.tables.attr_flags.set_nullable(def_id.local_def_index, attr_flags);
         }
     }
 
@@ -1189,8 +1207,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.super_predicates_of[def_id] <- self.tcx.super_predicates_of(def_id));
             }
             if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {
-                let params_in_repr = self.tcx.params_in_repr(def_id);
-                record!(self.tables.params_in_repr[def_id] <- params_in_repr);
+                self.encode_info_for_adt(def_id);
             }
             if should_encode_trait_impl_trait_tys(tcx, def_id)
                 && let Ok(table) = self.tcx.collect_return_position_impl_trait_in_trait_tys(def_id)
@@ -1213,46 +1230,53 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
     }
 
-    fn encode_enum_variant_info(&mut self, def: ty::AdtDef<'tcx>, index: VariantIdx) {
+    #[instrument(level = "trace", skip(self))]
+    fn encode_info_for_adt(&mut self, def_id: DefId) {
         let tcx = self.tcx;
-        let variant = &def.variant(index);
-        let def_id = variant.def_id;
-        debug!("EncodeContext::encode_enum_variant_info({:?})", def_id);
-
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
+        let adt_def = tcx.adt_def(def_id);
+        record!(self.tables.repr_options[def_id] <- adt_def.repr());
+
+        let params_in_repr = self.tcx.params_in_repr(def_id);
+        record!(self.tables.params_in_repr[def_id] <- params_in_repr);
 
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        record_array!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
-            assert!(f.did.is_local());
-            f.did.index
-        }));
-        if let Some((CtorKind::Fn, ctor_def_id)) = variant.ctor {
-            // FIXME(eddyb) encode signature only in `encode_enum_variant_ctor`.
-            record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(ctor_def_id));
+        if adt_def.is_enum() {
+            record_array!(self.tables.children[def_id] <- iter::from_generator(||
+                for variant in tcx.adt_def(def_id).variants() {
+                    yield variant.def_id.index;
+                    // Encode constructors which take a separate slot in value namespace.
+                    if let Some(ctor_def_id) = variant.ctor_def_id() {
+                        yield ctor_def_id.index;
+                    }
+                }
+            ));
+        } else {
+            // For non-enum, there is only one variant, and its def_id is the adt's.
+            debug_assert_eq!(adt_def.variants().len(), 1);
+            debug_assert_eq!(adt_def.non_enum_variant().def_id, def_id);
+            // Therefore, the loop over variants will encode its fields as the adt's children.
         }
-    }
 
-    fn encode_enum_variant_ctor(&mut self, def: ty::AdtDef<'tcx>, index: VariantIdx) {
-        let variant = &def.variant(index);
-        let Some((ctor_kind, def_id)) = variant.ctor else { return };
-        debug!("EncodeContext::encode_enum_variant_ctor({:?})", def_id);
+        for variant in adt_def.variants().iter() {
+            let data = VariantData {
+                discr: variant.discr,
+                ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
+                is_non_exhaustive: variant.is_field_list_non_exhaustive(),
+            };
+            record!(self.tables.variant_data[variant.def_id] <- data);
 
-        // FIXME(eddyb) encode only the `CtorKind` for constructors.
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: Some((ctor_kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
+            self.tables.constness.set(variant.def_id.index, hir::Constness::Const);
+            record_array!(self.tables.children[variant.def_id] <- variant.fields.iter().map(|f| {
+                assert!(f.did.is_local());
+                f.did.index
+            }));
 
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        if ctor_kind == CtorKind::Fn {
-            record!(self.tables.fn_sig[def_id] <- self.tcx.fn_sig(def_id));
+            if let Some((CtorKind::Fn, ctor_def_id)) = variant.ctor {
+                self.tables.constness.set(ctor_def_id.index, hir::Constness::Const);
+                let fn_sig = tcx.fn_sig(ctor_def_id);
+                record!(self.tables.fn_sig[ctor_def_id] <- fn_sig);
+                // FIXME only encode signature for ctor_def_id
+                record!(self.tables.fn_sig[variant.def_id] <- fn_sig);
+            }
         }
     }
 
@@ -1286,8 +1310,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                         hir::ItemKind::Struct(ref vdata, _) => {
                             yield item_id.owner_id.def_id.local_def_index;
                             // Encode constructors which take a separate slot in value namespace.
-                            if let Some(ctor_hir_id) = vdata.ctor_hir_id() {
-                                yield tcx.hir().local_def_id(ctor_hir_id).local_def_index;
+                            if let Some(ctor_def_id) = vdata.ctor_def_id() {
+                                yield ctor_def_id.local_def_index;
                             }
                         }
                         _ if tcx.def_key(item_id.owner_id.to_def_id()).get_opt_name().is_some() => {
@@ -1305,25 +1329,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
     }
 
-    fn encode_struct_ctor(&mut self, adt_def: ty::AdtDef<'tcx>) {
-        let variant = adt_def.non_enum_variant();
-        let Some((ctor_kind, def_id)) = variant.ctor else { return };
-        debug!("EncodeContext::encode_struct_ctor({:?})", def_id);
-
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: Some((ctor_kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
-
-        record!(self.tables.repr_options[def_id] <- adt_def.repr());
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        if ctor_kind == CtorKind::Fn {
-            record!(self.tables.fn_sig[def_id] <- self.tcx.fn_sig(def_id));
-        }
-    }
-
     fn encode_explicit_item_bounds(&mut self, def_id: DefId) {
         debug!("EncodeContext::encode_explicit_item_bounds({:?})", def_id);
         let bounds = self.tcx.explicit_item_bounds(def_id);
@@ -1387,7 +1392,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         if impl_item.kind == ty::AssocKind::Fn {
             record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
             if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
+                self.tables.is_intrinsic.set_nullable(def_id.index, true);
             }
         }
     }
@@ -1409,6 +1414,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             debug!("EntryBuilder::encode_mir({:?})", def_id);
             if encode_opt {
                 record!(self.tables.optimized_mir[def_id.to_def_id()] <- tcx.optimized_mir(def_id));
+
+                if let DefKind::Generator = self.tcx.def_kind(def_id) && tcx.sess.opts.unstable_opts.drop_tracking_mir {
+                    record!(self.tables.mir_generator_witnesses[def_id.to_def_id()] <- tcx.mir_generator_witnesses(def_id));
+                }
             }
             if encode_const {
                 record!(self.tables.mir_for_ctfe[def_id.to_def_id()] <- tcx.mir_for_ctfe(def_id));
@@ -1519,7 +1528,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             hir::ItemKind::Macro(ref macro_def, _) => {
                 if macro_def.macro_rules {
-                    self.tables.macro_rules.set(def_id.index, ());
+                    self.tables.is_macro_rules.set_nullable(def_id.index, true);
                 }
                 record!(self.tables.macro_definition[def_id] <- &*macro_def.body);
             }
@@ -1529,36 +1538,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             hir::ItemKind::OpaqueTy(ref opaque) => {
                 self.encode_explicit_item_bounds(def_id);
                 if matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias) {
-                    self.tables.is_type_alias_impl_trait.set(def_id.index, ());
+                    self.tables.is_type_alias_impl_trait.set_nullable(def_id.index, true);
                 }
             }
-            hir::ItemKind::Enum(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-            }
-            hir::ItemKind::Struct(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-                self.tables.constness.set(def_id.index, hir::Constness::Const);
-
-                let variant = adt_def.non_enum_variant();
-                record!(self.tables.variant_data[def_id] <- VariantData {
-                    discr: variant.discr,
-                    ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-                    is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-                });
-            }
-            hir::ItemKind::Union(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-
-                let variant = adt_def.non_enum_variant();
-                record!(self.tables.variant_data[def_id] <- VariantData {
-                    discr: variant.discr,
-                    ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-                    is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-                });
-            }
             hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => {
                 self.tables.impl_defaultness.set(def_id.index, *defaultness);
                 self.tables.constness.set(def_id.index, *constness);
@@ -1597,31 +1579,15 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             hir::ItemKind::Static(..)
             | hir::ItemKind::Const(..)
+            | hir::ItemKind::Enum(..)
+            | hir::ItemKind::Struct(..)
+            | hir::ItemKind::Union(..)
             | hir::ItemKind::ForeignMod { .. }
             | hir::ItemKind::GlobalAsm(..)
             | hir::ItemKind::TyAlias(..) => {}
         };
         // FIXME(eddyb) there should be a nicer way to do this.
         match item.kind {
-            hir::ItemKind::Enum(..) => {
-                record_array!(self.tables.children[def_id] <- iter::from_generator(||
-                    for variant in tcx.adt_def(def_id).variants() {
-                        yield variant.def_id.index;
-                        // Encode constructors which take a separate slot in value namespace.
-                        if let Some(ctor_def_id) = variant.ctor_def_id() {
-                            yield ctor_def_id.index;
-                        }
-                    }
-                ))
-            }
-            hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
-                record_array!(self.tables.children[def_id] <-
-                    self.tcx.adt_def(def_id).non_enum_variant().fields.iter().map(|f| {
-                        assert!(f.did.is_local());
-                        f.did.index
-                    })
-                )
-            }
             hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
                 let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
                 record_array!(self.tables.children[def_id] <-
@@ -1636,7 +1602,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         if let hir::ItemKind::Fn(..) = item.kind {
             record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
             if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
+                self.tables.is_intrinsic.set_nullable(def_id.index, true);
             }
         }
         if let hir::ItemKind::Impl { .. } = item.kind {
@@ -1649,17 +1615,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         // so it's easier to do that here then to wait until we would encounter
         // normally in the visitor walk.
         match item.kind {
-            hir::ItemKind::Enum(..) => {
-                let def = self.tcx.adt_def(item.owner_id.to_def_id());
-                for (i, _) in def.variants().iter_enumerated() {
-                    self.encode_enum_variant_info(def, i);
-                    self.encode_enum_variant_ctor(def, i);
-                }
-            }
-            hir::ItemKind::Struct(..) => {
-                let def = self.tcx.adt_def(item.owner_id.to_def_id());
-                self.encode_struct_ctor(def);
-            }
             hir::ItemKind::Impl { .. } => {
                 for &trait_item_def_id in
                     self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
@@ -1696,7 +1651,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             ty::Closure(_, substs) => {
                 let constness = self.tcx.constness(def_id.to_def_id());
                 self.tables.constness.set(def_id.to_def_id().index, constness);
-                record!(self.tables.fn_sig[def_id.to_def_id()] <- substs.as_closure().sig());
+                record!(self.tables.fn_sig[def_id.to_def_id()] <- ty::EarlyBinder(substs.as_closure().sig()));
             }
 
             _ => bug!("closure that is neither generator nor closure"),
@@ -2038,7 +1993,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
         if let hir::ForeignItemKind::Fn(..) = nitem.kind {
             if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
+                self.tables.is_intrinsic.set_nullable(def_id.index, true);
             }
         }
     }
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 69690264ae4..37af9e64e9a 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -185,9 +185,9 @@ enum LazyState {
     Previous(NonZeroUsize),
 }
 
-type SyntaxContextTable = LazyTable<u32, LazyValue<SyntaxContextData>>;
-type ExpnDataTable = LazyTable<ExpnIndex, LazyValue<ExpnData>>;
-type ExpnHashTable = LazyTable<ExpnIndex, LazyValue<ExpnHash>>;
+type SyntaxContextTable = LazyTable<u32, Option<LazyValue<SyntaxContextData>>>;
+type ExpnDataTable = LazyTable<ExpnIndex, Option<LazyValue<ExpnData>>>;
+type ExpnHashTable = LazyTable<ExpnIndex, Option<LazyValue<ExpnHash>>>;
 
 #[derive(MetadataEncodable, MetadataDecodable)]
 pub(crate) struct ProcMacroData {
@@ -253,7 +253,7 @@ pub(crate) struct CrateRoot {
 
     def_path_hash_map: LazyValue<DefPathHashMapRef<'static>>,
 
-    source_map: LazyTable<u32, LazyValue<rustc_span::SourceFile>>,
+    source_map: LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>>,
 
     compiler_builtins: bool,
     needs_allocator: bool,
@@ -315,21 +315,27 @@ pub(crate) struct IncoherentImpls {
 
 /// Define `LazyTables` and `TableBuilders` at the same time.
 macro_rules! define_tables {
-    ($($name:ident: Table<$IDX:ty, $T:ty>),+ $(,)?) => {
+    (
+        - nullable: $($name1:ident: Table<$IDX1:ty, $T1:ty>,)+
+        - optional: $($name2:ident: Table<$IDX2:ty, $T2:ty>,)+
+    ) => {
         #[derive(MetadataEncodable, MetadataDecodable)]
         pub(crate) struct LazyTables {
-            $($name: LazyTable<$IDX, $T>),+
+            $($name1: LazyTable<$IDX1, $T1>,)+
+            $($name2: LazyTable<$IDX2, Option<$T2>>,)+
         }
 
         #[derive(Default)]
         struct TableBuilders {
-            $($name: TableBuilder<$IDX, $T>),+
+            $($name1: TableBuilder<$IDX1, $T1>,)+
+            $($name2: TableBuilder<$IDX2, Option<$T2>>,)+
         }
 
         impl TableBuilders {
             fn encode(&self, buf: &mut FileEncoder) -> LazyTables {
                 LazyTables {
-                    $($name: self.$name.encode(buf)),+
+                    $($name1: self.$name1.encode(buf),)+
+                    $($name2: self.$name2.encode(buf),)+
                 }
             }
         }
@@ -337,9 +343,15 @@ macro_rules! define_tables {
 }
 
 define_tables! {
+- nullable:
+    is_intrinsic: Table<DefIndex, bool>,
+    is_macro_rules: Table<DefIndex, bool>,
+    is_type_alias_impl_trait: Table<DefIndex, bool>,
+    attr_flags: Table<DefIndex, AttrFlags>,
+
+- optional:
     attributes: Table<DefIndex, LazyArray<ast::Attribute>>,
     children: Table<DefIndex, LazyArray<DefIndex>>,
-
     opt_def_kind: Table<DefIndex, DefKind>,
     visibility: Table<DefIndex, LazyValue<ty::Visibility<DefIndex>>>,
     def_span: Table<DefIndex, LazyValue<Span>>,
@@ -357,20 +369,20 @@ define_tables! {
     super_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
     type_of: Table<DefIndex, LazyValue<Ty<'static>>>,
     variances_of: Table<DefIndex, LazyArray<ty::Variance>>,
-    fn_sig: Table<DefIndex, LazyValue<ty::PolyFnSig<'static>>>,
+    fn_sig: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::PolyFnSig<'static>>>>,
     codegen_fn_attrs: Table<DefIndex, LazyValue<CodegenFnAttrs>>,
     impl_trait_ref: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::TraitRef<'static>>>>,
     const_param_default: Table<DefIndex, LazyValue<ty::EarlyBinder<rustc_middle::ty::Const<'static>>>>,
     object_lifetime_default: Table<DefIndex, LazyValue<ObjectLifetimeDefault>>,
     optimized_mir: Table<DefIndex, LazyValue<mir::Body<'static>>>,
     mir_for_ctfe: Table<DefIndex, LazyValue<mir::Body<'static>>>,
+    mir_generator_witnesses: Table<DefIndex, LazyValue<mir::GeneratorLayout<'static>>>,
     promoted_mir: Table<DefIndex, LazyValue<IndexVec<mir::Promoted, mir::Body<'static>>>>,
     // FIXME(compiler-errors): Why isn't this a LazyArray?
     thir_abstract_const: Table<DefIndex, LazyValue<ty::Const<'static>>>,
     impl_parent: Table<DefIndex, RawDefId>,
     impl_polarity: Table<DefIndex, ty::ImplPolarity>,
     constness: Table<DefIndex, hir::Constness>,
-    is_intrinsic: Table<DefIndex, ()>,
     impl_defaultness: Table<DefIndex, hir::Defaultness>,
     // FIXME(eddyb) perhaps compute this on the fly if cheap enough?
     coerce_unsized_info: Table<DefIndex, LazyValue<ty::adjustment::CoerceUnsizedInfo>>,
@@ -380,7 +392,6 @@ define_tables! {
     fn_arg_names: Table<DefIndex, LazyArray<Ident>>,
     generator_kind: Table<DefIndex, LazyValue<hir::GeneratorKind>>,
     trait_def: Table<DefIndex, LazyValue<ty::TraitDef>>,
-
     trait_item_def_id: Table<DefIndex, RawDefId>,
     inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
     expn_that_defined: Table<DefIndex, LazyValue<ExpnId>>,
@@ -395,18 +406,12 @@ define_tables! {
     def_path_hashes: Table<DefIndex, DefPathHash>,
     proc_macro_quoted_spans: Table<usize, LazyValue<Span>>,
     generator_diagnostic_data: Table<DefIndex, LazyValue<GeneratorDiagnosticData<'static>>>,
-    attr_flags: Table<DefIndex, AttrFlags>,
     variant_data: Table<DefIndex, LazyValue<VariantData>>,
     assoc_container: Table<DefIndex, ty::AssocItemContainer>,
-    // Slot is full when macro is macro_rules.
-    macro_rules: Table<DefIndex, ()>,
     macro_definition: Table<DefIndex, LazyValue<ast::DelimArgs>>,
     proc_macro: Table<DefIndex, MacroKind>,
     module_reexports: Table<DefIndex, LazyArray<ModChild>>,
     deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
-    // Slot is full when opaque is TAIT.
-    is_type_alias_impl_trait: Table<DefIndex, ()>,
-
     trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, Ty<'static>>>>,
 }
 
@@ -419,6 +424,7 @@ struct VariantData {
 }
 
 bitflags::bitflags! {
+    #[derive(Default)]
     pub struct AttrFlags: u8 {
         const MAY_HAVE_DOC_LINKS = 1 << 0;
         const IS_DOC_HIDDEN      = 1 << 1;
diff --git a/compiler/rustc_metadata/src/rmeta/table.rs b/compiler/rustc_metadata/src/rmeta/table.rs
index dc003227d40..70dbf6476e2 100644
--- a/compiler/rustc_metadata/src/rmeta/table.rs
+++ b/compiler/rustc_metadata/src/rmeta/table.rs
@@ -16,6 +16,7 @@ use std::num::NonZeroUsize;
 /// but this has no impact on safety.
 pub(super) trait FixedSizeEncoding: Default {
     /// This should be `[u8; BYTE_LEN]`;
+    /// Cannot use an associated `const BYTE_LEN: usize` instead due to const eval limitations.
     type ByteArray;
 
     fn from_bytes(b: &Self::ByteArray) -> Self;
@@ -199,31 +200,31 @@ impl FixedSizeEncoding for Option<RawDefId> {
     }
 }
 
-impl FixedSizeEncoding for Option<AttrFlags> {
+impl FixedSizeEncoding for AttrFlags {
     type ByteArray = [u8; 1];
 
     #[inline]
     fn from_bytes(b: &[u8; 1]) -> Self {
-        (b[0] != 0).then(|| AttrFlags::from_bits_truncate(b[0]))
+        AttrFlags::from_bits_truncate(b[0])
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 1]) {
-        b[0] = self.map_or(0, |flags| flags.bits())
+        b[0] = self.bits();
     }
 }
 
-impl FixedSizeEncoding for Option<()> {
+impl FixedSizeEncoding for bool {
     type ByteArray = [u8; 1];
 
     #[inline]
     fn from_bytes(b: &[u8; 1]) -> Self {
-        (b[0] != 0).then(|| ())
+        b[0] != 0
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 1]) {
-        b[0] = self.is_some() as u8
+        b[0] = self as u8
     }
 }
 
@@ -273,44 +274,38 @@ impl<T> FixedSizeEncoding for Option<LazyArray<T>> {
 }
 
 /// Helper for constructing a table's serialization (also see `Table`).
-pub(super) struct TableBuilder<I: Idx, T>
-where
-    Option<T>: FixedSizeEncoding,
-{
-    blocks: IndexVec<I, <Option<T> as FixedSizeEncoding>::ByteArray>,
+pub(super) struct TableBuilder<I: Idx, T: FixedSizeEncoding> {
+    blocks: IndexVec<I, T::ByteArray>,
     _marker: PhantomData<T>,
 }
 
-impl<I: Idx, T> Default for TableBuilder<I, T>
-where
-    Option<T>: FixedSizeEncoding,
-{
+impl<I: Idx, T: FixedSizeEncoding> Default for TableBuilder<I, T> {
     fn default() -> Self {
         TableBuilder { blocks: Default::default(), _marker: PhantomData }
     }
 }
 
-impl<I: Idx, T> TableBuilder<I, T>
+impl<I: Idx, const N: usize, T> TableBuilder<I, Option<T>>
 where
-    Option<T>: FixedSizeEncoding,
+    Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
 {
-    pub(crate) fn set<const N: usize>(&mut self, i: I, value: T)
-    where
-        Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(crate) fn set(&mut self, i: I, value: T) {
+        self.set_nullable(i, Some(value))
+    }
+}
+
+impl<I: Idx, const N: usize, T: FixedSizeEncoding<ByteArray = [u8; N]>> TableBuilder<I, T> {
+    pub(crate) fn set_nullable(&mut self, i: I, value: T) {
         // FIXME(eddyb) investigate more compact encodings for sparse tables.
         // On the PR @michaelwoerister mentioned:
         // > Space requirements could perhaps be optimized by using the HAMT `popcnt`
         // > trick (i.e. divide things into buckets of 32 or 64 items and then
         // > store bit-masks of which item in each bucket is actually serialized).
         self.blocks.ensure_contains_elem(i, || [0; N]);
-        Some(value).write_to_bytes(&mut self.blocks[i]);
+        value.write_to_bytes(&mut self.blocks[i]);
     }
 
-    pub(crate) fn encode<const N: usize>(&self, buf: &mut FileEncoder) -> LazyTable<I, T>
-    where
-        Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(crate) fn encode(&self, buf: &mut FileEncoder) -> LazyTable<I, T> {
         let pos = buf.position();
         for block in &self.blocks {
             buf.emit_raw_bytes(block);
@@ -323,34 +318,27 @@ where
     }
 }
 
-impl<I: Idx, T: ParameterizedOverTcx> LazyTable<I, T>
+impl<I: Idx, const N: usize, T: FixedSizeEncoding<ByteArray = [u8; N]> + ParameterizedOverTcx>
+    LazyTable<I, T>
 where
-    Option<T>: FixedSizeEncoding,
+    for<'tcx> T::Value<'tcx>: FixedSizeEncoding<ByteArray = [u8; N]>,
 {
     /// Given the metadata, extract out the value at a particular index (if any).
     #[inline(never)]
-    pub(super) fn get<'a, 'tcx, M: Metadata<'a, 'tcx>, const N: usize>(
-        &self,
-        metadata: M,
-        i: I,
-    ) -> Option<T::Value<'tcx>>
-    where
-        Option<T::Value<'tcx>>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(super) fn get<'a, 'tcx, M: Metadata<'a, 'tcx>>(&self, metadata: M, i: I) -> T::Value<'tcx> {
         debug!("LazyTable::lookup: index={:?} len={:?}", i, self.encoded_size);
 
         let start = self.position.get();
         let bytes = &metadata.blob()[start..start + self.encoded_size];
         let (bytes, []) = bytes.as_chunks::<N>() else { panic!() };
-        let bytes = bytes.get(i.index())?;
-        FixedSizeEncoding::from_bytes(bytes)
+        match bytes.get(i.index()) {
+            Some(bytes) => FixedSizeEncoding::from_bytes(bytes),
+            None => FixedSizeEncoding::from_bytes(&[0; N]),
+        }
     }
 
     /// Size of the table in entries, including possible gaps.
-    pub(super) fn size<const N: usize>(&self) -> usize
-    where
-        for<'tcx> Option<T::Value<'tcx>>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(super) fn size(&self) -> usize {
         self.encoded_size / N
     }
 }
diff --git a/compiler/rustc_middle/src/arena.rs b/compiler/rustc_middle/src/arena.rs
index f816d614500..72f4f6e649b 100644
--- a/compiler/rustc_middle/src/arena.rs
+++ b/compiler/rustc_middle/src/arena.rs
@@ -105,7 +105,7 @@ macro_rules! arena_types {
             // (during lowering) and the `librustc_middle` arena (for decoding MIR)
             [decode] asm_template: rustc_ast::InlineAsmTemplatePiece,
             [decode] used_trait_imports: rustc_data_structures::unord::UnordSet<rustc_hir::def_id::LocalDefId>,
-            [decode] is_late_bound_map: rustc_data_structures::fx::FxIndexSet<rustc_hir::def_id::LocalDefId>,
+            [decode] is_late_bound_map: rustc_data_structures::fx::FxIndexSet<rustc_hir::ItemLocalId>,
             [decode] impl_source: rustc_middle::traits::ImplSource<'tcx, ()>,
 
             [] dep_kind: rustc_middle::dep_graph::DepKindStruct<'tcx>,
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 9e63c2bd221..5bd6b070442 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -18,24 +18,30 @@ use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 
 #[inline]
-pub fn associated_body(node: Node<'_>) -> Option<BodyId> {
+pub fn associated_body(node: Node<'_>) -> Option<(LocalDefId, BodyId)> {
     match node {
         Node::Item(Item {
+            owner_id,
             kind: ItemKind::Const(_, body) | ItemKind::Static(.., body) | ItemKind::Fn(.., body),
             ..
         })
         | Node::TraitItem(TraitItem {
+            owner_id,
             kind:
                 TraitItemKind::Const(_, Some(body)) | TraitItemKind::Fn(_, TraitFn::Provided(body)),
             ..
         })
         | Node::ImplItem(ImplItem {
+            owner_id,
             kind: ImplItemKind::Const(_, body) | ImplItemKind::Fn(_, body),
             ..
-        })
-        | Node::Expr(Expr { kind: ExprKind::Closure(Closure { body, .. }), .. }) => Some(*body),
+        }) => Some((owner_id.def_id, *body)),
+
+        Node::Expr(Expr { kind: ExprKind::Closure(Closure { def_id, body, .. }), .. }) => {
+            Some((*def_id, *body))
+        }
 
-        Node::AnonConst(constant) => Some(constant.body),
+        Node::AnonConst(constant) => Some((constant.def_id, constant.body)),
 
         _ => None,
     }
@@ -43,7 +49,7 @@ pub fn associated_body(node: Node<'_>) -> Option<BodyId> {
 
 fn is_body_owner(node: Node<'_>, hir_id: HirId) -> bool {
     match associated_body(node) {
-        Some(b) => b.hir_id == hir_id,
+        Some((_, b)) => b.hir_id == hir_id,
         None => false,
     }
 }
@@ -154,10 +160,6 @@ impl<'hir> Map<'hir> {
         self.tcx.definitions_untracked().def_key(def_id)
     }
 
-    pub fn def_path_from_hir_id(self, id: HirId) -> Option<DefPath> {
-        self.opt_local_def_id(id).map(|def_id| self.def_path(def_id))
-    }
-
     pub fn def_path(self, def_id: LocalDefId) -> DefPath {
         // Accessing the DefPath is ok, since it is part of DefPathHash.
         self.tcx.definitions_untracked().def_path(def_id)
@@ -170,32 +172,6 @@ impl<'hir> Map<'hir> {
     }
 
     #[inline]
-    #[track_caller]
-    pub fn local_def_id(self, hir_id: HirId) -> LocalDefId {
-        self.opt_local_def_id(hir_id).unwrap_or_else(|| {
-            bug!(
-                "local_def_id: no entry for `{:?}`, which has a map of `{:?}`",
-                hir_id,
-                self.find(hir_id)
-            )
-        })
-    }
-
-    #[inline]
-    pub fn opt_local_def_id(self, hir_id: HirId) -> Option<LocalDefId> {
-        if hir_id.local_id == ItemLocalId::new(0) {
-            Some(hir_id.owner.def_id)
-        } else {
-            self.tcx
-                .hir_owner_nodes(hir_id.owner)
-                .as_owner()?
-                .local_id_to_def_id
-                .get(&hir_id.local_id)
-                .copied()
-        }
-    }
-
-    #[inline]
     pub fn local_def_id_to_hir_id(self, def_id: LocalDefId) -> HirId {
         self.tcx.local_def_id_to_hir_id(def_id)
     }
@@ -410,8 +386,8 @@ impl<'hir> Map<'hir> {
     #[track_caller]
     pub fn enclosing_body_owner(self, hir_id: HirId) -> LocalDefId {
         for (_, node) in self.parent_iter(hir_id) {
-            if let Some(body) = associated_body(node) {
-                return self.body_owner_def_id(body);
+            if let Some((def_id, _)) = associated_body(node) {
+                return def_id;
             }
         }
 
@@ -427,14 +403,17 @@ impl<'hir> Map<'hir> {
         parent
     }
 
-    pub fn body_owner_def_id(self, id: BodyId) -> LocalDefId {
-        self.local_def_id(self.body_owner(id))
+    pub fn body_owner_def_id(self, BodyId { hir_id }: BodyId) -> LocalDefId {
+        let parent = self.parent_id(hir_id);
+        associated_body(self.get(parent)).unwrap().0
     }
 
     /// Given a `LocalDefId`, returns the `BodyId` associated with it,
     /// if the node is a body owner, otherwise returns `None`.
     pub fn maybe_body_owned_by(self, id: LocalDefId) -> Option<BodyId> {
-        self.find_by_def_id(id).and_then(associated_body)
+        let node = self.find_by_def_id(id)?;
+        let (_, body_id) = associated_body(node)?;
+        Some(body_id)
     }
 
     /// Given a body owner's id, returns the `BodyId` associated with it.
diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index 43583b5723e..6e130bbf7d8 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -25,10 +25,8 @@ use crate::infer::MemberConstraint;
 use crate::mir::ConstraintCategory;
 use crate::ty::subst::GenericArg;
 use crate::ty::{self, BoundVar, List, Region, Ty, TyCtxt};
-use rustc_index::vec::IndexVec;
 use rustc_macros::HashStable;
 use smallvec::SmallVec;
-use std::iter;
 use std::ops::Index;
 
 /// A "canonicalized" type `V` is one where all free inference
@@ -62,23 +60,23 @@ impl<'tcx> ty::TypeFoldable<'tcx> for CanonicalVarInfos<'tcx> {
 /// vectors with the original values that were replaced by canonical
 /// variables. You will need to supply it later to instantiate the
 /// canonicalized query response.
-#[derive(Clone, Debug, PartialEq, Eq, Hash, TyDecodable, TyEncodable)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyDecodable, TyEncodable)]
 #[derive(HashStable, TypeFoldable, TypeVisitable, Lift)]
 pub struct CanonicalVarValues<'tcx> {
-    pub var_values: IndexVec<BoundVar, GenericArg<'tcx>>,
+    pub var_values: ty::SubstsRef<'tcx>,
 }
 
 impl CanonicalVarValues<'_> {
     pub fn is_identity(&self) -> bool {
-        self.var_values.iter_enumerated().all(|(bv, arg)| match arg.unpack() {
+        self.var_values.iter().enumerate().all(|(bv, arg)| match arg.unpack() {
             ty::GenericArgKind::Lifetime(r) => {
-                matches!(*r, ty::ReLateBound(ty::INNERMOST, br) if br.var == bv)
+                matches!(*r, ty::ReLateBound(ty::INNERMOST, br) if br.var.as_usize() == bv)
             }
             ty::GenericArgKind::Type(ty) => {
-                matches!(*ty.kind(), ty::Bound(ty::INNERMOST, bt) if bt.var == bv)
+                matches!(*ty.kind(), ty::Bound(ty::INNERMOST, bt) if bt.var.as_usize() == bv)
             }
             ty::GenericArgKind::Const(ct) => {
-                matches!(ct.kind(), ty::ConstKind::Bound(ty::INNERMOST, bc) if bc == bv)
+                matches!(ct.kind(), ty::ConstKind::Bound(ty::INNERMOST, bc) if bc.as_usize() == bv)
             }
         })
     }
@@ -339,57 +337,57 @@ TrivialTypeTraversalAndLiftImpls! {
 }
 
 impl<'tcx> CanonicalVarValues<'tcx> {
+    // Given a list of canonical variables, construct a set of values which are
+    // the identity response.
+    pub fn make_identity(
+        tcx: TyCtxt<'tcx>,
+        infos: CanonicalVarInfos<'tcx>,
+    ) -> CanonicalVarValues<'tcx> {
+        CanonicalVarValues {
+            var_values: tcx.mk_substs(infos.iter().enumerate().map(
+                |(i, info)| -> ty::GenericArg<'tcx> {
+                    match info.kind {
+                        CanonicalVarKind::Ty(_) | CanonicalVarKind::PlaceholderTy(_) => tcx
+                            .mk_ty(ty::Bound(ty::INNERMOST, ty::BoundVar::from_usize(i).into()))
+                            .into(),
+                        CanonicalVarKind::Region(_) | CanonicalVarKind::PlaceholderRegion(_) => {
+                            let br = ty::BoundRegion {
+                                var: ty::BoundVar::from_usize(i),
+                                kind: ty::BrAnon(i as u32, None),
+                            };
+                            tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)).into()
+                        }
+                        CanonicalVarKind::Const(_, ty)
+                        | CanonicalVarKind::PlaceholderConst(_, ty) => tcx
+                            .mk_const(
+                                ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from_usize(i)),
+                                ty,
+                            )
+                            .into(),
+                    }
+                },
+            )),
+        }
+    }
+
     /// Creates dummy var values which should not be used in a
     /// canonical response.
     pub fn dummy() -> CanonicalVarValues<'tcx> {
-        CanonicalVarValues { var_values: Default::default() }
+        CanonicalVarValues { var_values: ty::List::empty() }
     }
 
     #[inline]
     pub fn len(&self) -> usize {
         self.var_values.len()
     }
-
-    /// Makes an identity substitution from this one: each bound var
-    /// is matched to the same bound var, preserving the original kinds.
-    /// For example, if we have:
-    /// `self.var_values == [Type(u32), Lifetime('a), Type(u64)]`
-    /// we'll return a substitution `subst` with:
-    /// `subst.var_values == [Type(^0), Lifetime(^1), Type(^2)]`.
-    pub fn make_identity(&self, tcx: TyCtxt<'tcx>) -> Self {
-        use crate::ty::subst::GenericArgKind;
-
-        CanonicalVarValues {
-            var_values: iter::zip(&self.var_values, 0..)
-                .map(|(kind, i)| match kind.unpack() {
-                    GenericArgKind::Type(..) => {
-                        tcx.mk_ty(ty::Bound(ty::INNERMOST, ty::BoundVar::from_u32(i).into())).into()
-                    }
-                    GenericArgKind::Lifetime(..) => {
-                        let br = ty::BoundRegion {
-                            var: ty::BoundVar::from_u32(i),
-                            kind: ty::BrAnon(i, None),
-                        };
-                        tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)).into()
-                    }
-                    GenericArgKind::Const(ct) => tcx
-                        .mk_const(
-                            ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from_u32(i)),
-                            ct.ty(),
-                        )
-                        .into(),
-                })
-                .collect(),
-        }
-    }
 }
 
 impl<'a, 'tcx> IntoIterator for &'a CanonicalVarValues<'tcx> {
     type Item = GenericArg<'tcx>;
-    type IntoIter = ::std::iter::Cloned<::std::slice::Iter<'a, GenericArg<'tcx>>>;
+    type IntoIter = ::std::iter::Copied<::std::slice::Iter<'a, GenericArg<'tcx>>>;
 
     fn into_iter(self) -> Self::IntoIter {
-        self.var_values.iter().cloned()
+        self.var_values.iter()
     }
 }
 
@@ -397,6 +395,6 @@ impl<'tcx> Index<BoundVar> for CanonicalVarValues<'tcx> {
     type Output = GenericArg<'tcx>;
 
     fn index(&self, value: BoundVar) -> &GenericArg<'tcx> {
-        &self.var_values[value]
+        &self.var_values[value.as_usize()]
     }
 }
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 7e4063c2ffd..95148de2518 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -43,6 +43,7 @@
 #![feature(min_specialization)]
 #![feature(trusted_len)]
 #![feature(type_alias_impl_trait)]
+#![feature(strict_provenance)]
 #![feature(associated_type_bounds)]
 #![feature(rustc_attrs)]
 #![feature(control_flow_enum)]
diff --git a/compiler/rustc_middle/src/mir/basic_blocks.rs b/compiler/rustc_middle/src/mir/basic_blocks.rs
index b3354e6e9d2..b93871769b7 100644
--- a/compiler/rustc_middle/src/mir/basic_blocks.rs
+++ b/compiler/rustc_middle/src/mir/basic_blocks.rs
@@ -41,7 +41,6 @@ impl<'tcx> BasicBlocks<'tcx> {
         *self.cache.is_cyclic.get_or_init(|| graph::is_cyclic(self))
     }
 
-    #[inline]
     pub fn dominators(&self) -> Dominators<BasicBlock> {
         dominators(&self)
     }
diff --git a/compiler/rustc_middle/src/mir/interpret/mod.rs b/compiler/rustc_middle/src/mir/interpret/mod.rs
index 5f425a28768..b0975616b61 100644
--- a/compiler/rustc_middle/src/mir/interpret/mod.rs
+++ b/compiler/rustc_middle/src/mir/interpret/mod.rs
@@ -110,7 +110,7 @@ use rustc_hir::def_id::DefId;
 use rustc_macros::HashStable;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_serialize::{Decodable, Encodable};
-use rustc_target::abi::Endian;
+use rustc_target::abi::{AddressSpace, Endian, HasDataLayout};
 
 use crate::mir;
 use crate::ty::codec::{TyDecoder, TyEncoder};
@@ -438,6 +438,17 @@ impl<'tcx> GlobalAlloc<'tcx> {
             _ => bug!("expected vtable, got {:?}", self),
         }
     }
+
+    /// The address space that this `GlobalAlloc` should be placed in.
+    #[inline]
+    pub fn address_space(&self, cx: &impl HasDataLayout) -> AddressSpace {
+        match self {
+            GlobalAlloc::Function(..) => cx.data_layout().instruction_address_space,
+            GlobalAlloc::Static(..) | GlobalAlloc::Memory(..) | GlobalAlloc::VTable(..) => {
+                AddressSpace::DATA
+            }
+        }
+    }
 }
 
 pub(crate) struct AllocMap<'tcx> {
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index d833286dc33..552af589bec 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -902,6 +902,8 @@ pub enum LocalInfo<'tcx> {
     AggregateTemp,
     /// A temporary created during the pass `Derefer` to avoid it's retagging
     DerefTemp,
+    /// A temporary created for borrow checking.
+    FakeBorrow,
 }
 
 impl<'tcx> LocalDecl<'tcx> {
@@ -1461,6 +1463,7 @@ impl Debug for Statement<'_> {
             }
             Coverage(box ref coverage) => write!(fmt, "Coverage::{:?}", coverage.kind),
             Intrinsic(box ref intrinsic) => write!(fmt, "{intrinsic}"),
+            ConstEvalCounter => write!(fmt, "ConstEvalCounter"),
             Nop => write!(fmt, "nop"),
         }
     }
@@ -2504,7 +2507,7 @@ impl<'tcx> ConstantKind<'tcx> {
 
         let hir_id = tcx.hir().local_def_id_to_hir_id(def.did);
         let parent_substs = if let Some(parent_hir_id) = tcx.hir().opt_parent_id(hir_id) {
-            if let Some(parent_did) = tcx.hir().opt_local_def_id(parent_hir_id) {
+            if let Some(parent_did) = parent_hir_id.as_owner() {
                 InternalSubsts::identity_for_item(tcx, parent_did.to_def_id())
             } else {
                 tcx.mk_substs(Vec::<GenericArg<'tcx>>::new().into_iter())
@@ -3046,7 +3049,7 @@ impl Location {
         if self.block == other.block {
             self.statement_index <= other.statement_index
         } else {
-            dominators.is_dominated_by(other.block, self.block)
+            dominators.dominates(self.block, other.block)
         }
     }
 }
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 1e8d5f7eae8..7a05ee2ff37 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -318,16 +318,19 @@ impl<'tcx> CodegenUnit<'tcx> {
         base_n::encode(hash, base_n::CASE_INSENSITIVE)
     }
 
-    pub fn estimate_size(&mut self, tcx: TyCtxt<'tcx>) {
+    pub fn create_size_estimate(&mut self, tcx: TyCtxt<'tcx>) {
         // Estimate the size of a codegen unit as (approximately) the number of MIR
         // statements it corresponds to.
         self.size_estimate = Some(self.items.keys().map(|mi| mi.size_estimate(tcx)).sum());
     }
 
     #[inline]
+    /// Should only be called if [`create_size_estimate`] has previously been called.
+    ///
+    /// [`create_size_estimate`]: Self::create_size_estimate
     pub fn size_estimate(&self) -> usize {
-        // Should only be called if `estimate_size` has previously been called.
-        self.size_estimate.expect("estimate_size must be called before getting a size_estimate")
+        self.size_estimate
+            .expect("create_size_estimate must be called before getting a size_estimate")
     }
 
     pub fn modify_size_estimate(&mut self, delta: usize) {
diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs
index a8a4532223c..6155f2bb56c 100644
--- a/compiler/rustc_middle/src/mir/query.rs
+++ b/compiler/rustc_middle/src/mir/query.rs
@@ -135,11 +135,20 @@ rustc_index::newtype_index! {
     pub struct GeneratorSavedLocal {}
 }
 
+#[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable, TypeFoldable, TypeVisitable)]
+pub struct GeneratorSavedTy<'tcx> {
+    pub ty: Ty<'tcx>,
+    /// Source info corresponding to the local in the original MIR body.
+    pub source_info: SourceInfo,
+    /// Whether the local should be ignored for trait bound computations.
+    pub ignore_for_traits: bool,
+}
+
 /// The layout of generator state.
 #[derive(Clone, TyEncodable, TyDecodable, HashStable, TypeFoldable, TypeVisitable)]
 pub struct GeneratorLayout<'tcx> {
     /// The type of every local stored inside the generator.
-    pub field_tys: IndexVec<GeneratorSavedLocal, Ty<'tcx>>,
+    pub field_tys: IndexVec<GeneratorSavedLocal, GeneratorSavedTy<'tcx>>,
 
     /// Which of the above fields are in each variant. Note that one field may
     /// be stored in multiple variants.
diff --git a/compiler/rustc_middle/src/mir/spanview.rs b/compiler/rustc_middle/src/mir/spanview.rs
index 887ee571575..1610ae1ce14 100644
--- a/compiler/rustc_middle/src/mir/spanview.rs
+++ b/compiler/rustc_middle/src/mir/spanview.rs
@@ -250,6 +250,7 @@ pub fn statement_kind_name(statement: &Statement<'_>) -> &'static str {
         AscribeUserType(..) => "AscribeUserType",
         Coverage(..) => "Coverage",
         Intrinsic(..) => "Intrinsic",
+        ConstEvalCounter => "ConstEvalCounter",
         Nop => "Nop",
     }
 }
@@ -670,7 +671,7 @@ fn fn_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span {
 
 fn hir_body(tcx: TyCtxt<'_>, def_id: DefId) -> Option<&rustc_hir::Body<'_>> {
     let hir_node = tcx.hir().get_if_local(def_id).expect("expected DefId is local");
-    hir::map::associated_body(hir_node).map(|fn_body_id| tcx.hir().body(fn_body_id))
+    hir::map::associated_body(hir_node).map(|(_, fn_body_id)| tcx.hir().body(fn_body_id))
 }
 
 fn escape_html(s: &str) -> String {
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index 52c2b10cbbe..549bc65d6d7 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -355,6 +355,12 @@ pub enum StatementKind<'tcx> {
     /// This avoids adding a new block and a terminator for simple intrinsics.
     Intrinsic(Box<NonDivergingIntrinsic<'tcx>>),
 
+    /// Instructs the const eval interpreter to increment a counter; this counter is used to track
+    /// how many steps the interpreter has taken. It is used to prevent the user from writing const
+    /// code that runs for too long or infinitely. Other than in the const eval interpreter, this
+    /// is a no-op.
+    ConstEvalCounter,
+
     /// No-op. Useful for deleting instructions without affecting statement indices.
     Nop,
 }
diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs
index 1a264d2d5af..3ddac5e11fb 100644
--- a/compiler/rustc_middle/src/mir/visit.rs
+++ b/compiler/rustc_middle/src/mir/visit.rs
@@ -427,6 +427,7 @@ macro_rules! make_mir_visitor {
                             }
                         }
                     }
+                    StatementKind::ConstEvalCounter => {}
                     StatementKind::Nop => {}
                 }
             }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 7db86c8d0d4..4cebe416354 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -183,6 +183,15 @@ rustc_queries! {
         separate_provide_extern
     }
 
+    query unsizing_params_for_adt(key: DefId) -> rustc_index::bit_set::BitSet<u32>
+    {
+        arena_cache
+        desc { |tcx|
+            "determining what parameters of `{}` can participate in unsizing",
+            tcx.def_path_str(key),
+        }
+    }
+
     query analysis(key: ()) -> Result<(), ErrorGuaranteed> {
         eval_always
         desc { "running analysis passes on this crate" }
@@ -361,6 +370,13 @@ rustc_queries! {
         desc { |tcx| "constructing THIR tree for `{}`", tcx.def_path_str(key.did.to_def_id()) }
     }
 
+    /// Create a list-like THIR representation for debugging.
+    query thir_flat(key: ty::WithOptConstParam<LocalDefId>) -> String {
+        no_hash
+        arena_cache
+        desc { |tcx| "constructing flat THIR representation for `{}`", tcx.def_path_str(key.did.to_def_id()) }
+    }
+
     /// Set of all the `DefId`s in this crate that have MIR associated with
     /// them. This includes all the body owners, but also things like struct
     /// constructors.
@@ -471,6 +487,17 @@ rustc_queries! {
         }
     }
 
+    query mir_generator_witnesses(key: DefId) -> mir::GeneratorLayout<'tcx> {
+        arena_cache
+        desc { |tcx| "generator witness types for `{}`", tcx.def_path_str(key) }
+        cache_on_disk_if { key.is_local() }
+        separate_provide_extern
+    }
+
+    query check_generator_obligations(key: LocalDefId) {
+        desc { |tcx| "verify auto trait bounds for generator interior type `{}`", tcx.def_path_str(key.to_def_id()) }
+    }
+
     /// MIR after our optimization passes have run. This is MIR that is ready
     /// for codegen. This is also the only query that can fetch non-local MIR, at present.
     query optimized_mir(key: DefId) -> &'tcx mir::Body<'tcx> {
@@ -796,15 +823,6 @@ rustc_queries! {
         }
     }
 
-    /// HACK: when evaluated, this reports an "unsafe derive on repr(packed)" error.
-    ///
-    /// Unsafety checking is executed for each method separately, but we only want
-    /// to emit this error once per derive. As there are some impls with multiple
-    /// methods, we use a query for deduplication.
-    query unsafe_derive_on_repr_packed(key: LocalDefId) -> () {
-        desc { |tcx| "processing `{}`", tcx.def_path_str(key.to_def_id()) }
-    }
-
     /// Returns the types assumed to be well formed while "inside" of the given item.
     ///
     /// Note that we've liberated the late bound regions of function signatures, so
@@ -814,7 +832,7 @@ rustc_queries! {
     }
 
     /// Computes the signature of the function.
-    query fn_sig(key: DefId) -> ty::PolyFnSig<'tcx> {
+    query fn_sig(key: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'tcx>> {
         desc { |tcx| "computing function signature of `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }
         separate_provide_extern
@@ -1263,6 +1281,9 @@ rustc_queries! {
     query object_safety_violations(trait_id: DefId) -> &'tcx [traits::ObjectSafetyViolation] {
         desc { |tcx| "determining object safety of trait `{}`", tcx.def_path_str(trait_id) }
     }
+    query check_is_object_safe(trait_id: DefId) -> bool {
+        desc { |tcx| "checking if trait `{}` is object safe", tcx.def_path_str(trait_id) }
+    }
 
     /// Gets the ParameterEnvironment for a given item; this environment
     /// will be in "user-facing" mode, meaning that it is suitable for
@@ -1629,7 +1650,7 @@ rustc_queries! {
         Option<&'tcx FxHashMap<ItemLocalId, Region>> {
         desc { "looking up a named region" }
     }
-    query is_late_bound_map(_: LocalDefId) -> Option<&'tcx FxIndexSet<LocalDefId>> {
+    query is_late_bound_map(_: hir::OwnerId) -> Option<&'tcx FxIndexSet<ItemLocalId>> {
         desc { "testing if a region is late bound" }
     }
     /// For a given item's generic parameter, gets the default lifetimes to be used
@@ -1863,9 +1884,10 @@ rustc_queries! {
     ///
     /// This query returns an `&Arc` because codegen backends need the value even after the `TyCtxt`
     /// has been destroyed.
-    query output_filenames(_: ()) -> &'tcx Arc<OutputFilenames> {
+    query output_filenames(_: ()) -> Arc<OutputFilenames> {
         feedable
         desc { "getting output filenames" }
+        arena_cache
     }
 
     /// Do not call this query directly: invoke `normalize` instead.
@@ -2116,12 +2138,12 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query permits_uninit_init(key: TyAndLayout<'tcx>) -> bool {
-        desc { "checking to see if `{}` permits being left uninit", key.ty }
+    query permits_uninit_init(key: ty::ParamEnvAnd<'tcx, TyAndLayout<'tcx>>) -> bool {
+        desc { "checking to see if `{}` permits being left uninit", key.value.ty }
     }
 
-    query permits_zero_init(key: TyAndLayout<'tcx>) -> bool {
-        desc { "checking to see if `{}` permits being left zeroed", key.ty }
+    query permits_zero_init(key: ty::ParamEnvAnd<'tcx, TyAndLayout<'tcx>>) -> bool {
+        desc { "checking to see if `{}` permits being left zeroed", key.value.ty }
     }
 
     query compare_impl_const(
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index 5f320708c84..6f2dac46753 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -29,6 +29,7 @@ use rustc_target::asm::InlineAsmRegOrRegClass;
 use std::fmt;
 use std::ops::Index;
 
+pub mod print;
 pub mod visit;
 
 macro_rules! thir_with_elements {
diff --git a/compiler/rustc_middle/src/thir/print.rs b/compiler/rustc_middle/src/thir/print.rs
new file mode 100644
index 00000000000..60b903e9906
--- /dev/null
+++ b/compiler/rustc_middle/src/thir/print.rs
@@ -0,0 +1,881 @@
+use crate::thir::*;
+use crate::ty::{self, TyCtxt};
+
+use std::fmt::{self, Write};
+
+impl<'tcx> TyCtxt<'tcx> {
+    pub fn thir_tree_representation<'a>(self, thir: &'a Thir<'tcx>) -> String {
+        let mut printer = ThirPrinter::new(thir);
+        printer.print();
+        printer.into_buffer()
+    }
+}
+
+struct ThirPrinter<'a, 'tcx> {
+    thir: &'a Thir<'tcx>,
+    fmt: String,
+}
+
+const INDENT: &str = "    ";
+
+macro_rules! print_indented {
+    ($writer:ident, $s:expr, $indent_lvl:expr) => {
+        let indent = (0..$indent_lvl).map(|_| INDENT).collect::<Vec<_>>().concat();
+        writeln!($writer, "{}{}", indent, $s).expect("unable to write to ThirPrinter");
+    };
+}
+
+impl<'a, 'tcx> Write for ThirPrinter<'a, 'tcx> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.fmt.push_str(s);
+        Ok(())
+    }
+}
+
+impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
+    fn new(thir: &'a Thir<'tcx>) -> Self {
+        Self { thir, fmt: String::new() }
+    }
+
+    fn print(&mut self) {
+        print_indented!(self, "params: [", 0);
+        for param in self.thir.params.iter() {
+            self.print_param(param, 1);
+        }
+        print_indented!(self, "]", 0);
+
+        print_indented!(self, "body:", 0);
+        let expr = ExprId::from_usize(self.thir.exprs.len() - 1);
+        self.print_expr(expr, 1);
+    }
+
+    fn into_buffer(self) -> String {
+        self.fmt
+    }
+
+    fn print_param(&mut self, param: &Param<'tcx>, depth_lvl: usize) {
+        let Param { pat, ty, ty_span, self_kind, hir_id } = param;
+
+        print_indented!(self, "Param {", depth_lvl);
+        print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 1);
+        print_indented!(self, format!("ty_span: {:?}", ty_span), depth_lvl + 1);
+        print_indented!(self, format!("self_kind: {:?}", self_kind), depth_lvl + 1);
+        print_indented!(self, format!("hir_id: {:?}", hir_id), depth_lvl + 1);
+
+        if let Some(pat) = pat {
+            print_indented!(self, "param: Some( ", depth_lvl + 1);
+            self.print_pat(pat, depth_lvl + 2);
+            print_indented!(self, ")", depth_lvl + 1);
+        } else {
+            print_indented!(self, "param: None", depth_lvl + 1);
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_block(&mut self, block_id: BlockId, depth_lvl: usize) {
+        let Block {
+            targeted_by_break,
+            opt_destruction_scope,
+            span,
+            region_scope,
+            stmts,
+            expr,
+            safety_mode,
+        } = &self.thir.blocks[block_id];
+
+        print_indented!(self, "Block {", depth_lvl);
+        print_indented!(self, format!("targeted_by_break: {}", targeted_by_break), depth_lvl + 1);
+        print_indented!(
+            self,
+            format!("opt_destruction_scope: {:?}", opt_destruction_scope),
+            depth_lvl + 1
+        );
+        print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+        print_indented!(self, format!("region_scope: {:?}", region_scope), depth_lvl + 1);
+        print_indented!(self, format!("safety_mode: {:?}", safety_mode), depth_lvl + 1);
+
+        if stmts.len() > 0 {
+            print_indented!(self, "stmts: [", depth_lvl + 1);
+            for stmt in stmts.iter() {
+                self.print_stmt(*stmt, depth_lvl + 2);
+            }
+            print_indented!(self, "]", depth_lvl + 1);
+        } else {
+            print_indented!(self, "stmts: []", depth_lvl + 1);
+        }
+
+        if let Some(expr_id) = expr {
+            print_indented!(self, "expr:", depth_lvl + 1);
+            self.print_expr(*expr_id, depth_lvl + 2);
+        } else {
+            print_indented!(self, "expr: []", depth_lvl + 1);
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_stmt(&mut self, stmt_id: StmtId, depth_lvl: usize) {
+        let Stmt { kind, opt_destruction_scope } = &self.thir.stmts[stmt_id];
+
+        print_indented!(self, "Stmt {", depth_lvl);
+        print_indented!(
+            self,
+            format!("opt_destruction_scope: {:?}", opt_destruction_scope),
+            depth_lvl + 1
+        );
+
+        match kind {
+            StmtKind::Expr { scope, expr } => {
+                print_indented!(self, "kind: Expr {", depth_lvl + 1);
+                print_indented!(self, format!("scope: {:?}", scope), depth_lvl + 2);
+                print_indented!(self, "expr:", depth_lvl + 2);
+                self.print_expr(*expr, depth_lvl + 3);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            StmtKind::Let {
+                remainder_scope,
+                init_scope,
+                pattern,
+                initializer,
+                else_block,
+                lint_level,
+            } => {
+                print_indented!(self, "kind: Let {", depth_lvl + 1);
+                print_indented!(
+                    self,
+                    format!("remainder_scope: {:?}", remainder_scope),
+                    depth_lvl + 2
+                );
+                print_indented!(self, format!("init_scope: {:?}", init_scope), depth_lvl + 2);
+
+                print_indented!(self, "pattern: ", depth_lvl + 2);
+                self.print_pat(pattern, depth_lvl + 3);
+                print_indented!(self, ",", depth_lvl + 2);
+
+                if let Some(init) = initializer {
+                    print_indented!(self, "initializer: Some(", depth_lvl + 2);
+                    self.print_expr(*init, depth_lvl + 3);
+                    print_indented!(self, ")", depth_lvl + 2);
+                } else {
+                    print_indented!(self, "initializer: None", depth_lvl + 2);
+                }
+
+                if let Some(else_block) = else_block {
+                    print_indented!(self, "else_block: Some(", depth_lvl + 2);
+                    self.print_block(*else_block, depth_lvl + 3);
+                    print_indented!(self, ")", depth_lvl + 2);
+                } else {
+                    print_indented!(self, "else_block: None", depth_lvl + 2);
+                }
+
+                print_indented!(self, format!("lint_level: {:?}", lint_level), depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_expr(&mut self, expr: ExprId, depth_lvl: usize) {
+        let Expr { ty, temp_lifetime, span, kind } = &self.thir[expr];
+        print_indented!(self, "Expr {", depth_lvl);
+        print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 1);
+        print_indented!(self, format!("temp_lifetime: {:?}", temp_lifetime), depth_lvl + 1);
+        print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+        print_indented!(self, "kind: ", depth_lvl + 1);
+        self.print_expr_kind(kind, depth_lvl + 2);
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_expr_kind(&mut self, expr_kind: &ExprKind<'tcx>, depth_lvl: usize) {
+        use rustc_middle::thir::ExprKind::*;
+
+        match expr_kind {
+            Scope { region_scope, value, lint_level } => {
+                print_indented!(self, "Scope {", depth_lvl);
+                print_indented!(self, format!("region_scope: {:?}", region_scope), depth_lvl + 1);
+                print_indented!(self, format!("lint_level: {:?}", lint_level), depth_lvl + 1);
+                print_indented!(self, "value:", depth_lvl + 1);
+                self.print_expr(*value, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Box { value } => {
+                print_indented!(self, "Box {", depth_lvl);
+                self.print_expr(*value, depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            If { if_then_scope, cond, then, else_opt } => {
+                print_indented!(self, "If {", depth_lvl);
+                print_indented!(self, format!("if_then_scope: {:?}", if_then_scope), depth_lvl + 1);
+                print_indented!(self, "cond:", depth_lvl + 1);
+                self.print_expr(*cond, depth_lvl + 2);
+                print_indented!(self, "then:", depth_lvl + 1);
+                self.print_expr(*then, depth_lvl + 2);
+
+                if let Some(else_expr) = else_opt {
+                    print_indented!(self, "else:", depth_lvl + 1);
+                    self.print_expr(*else_expr, depth_lvl + 2);
+                }
+
+                print_indented!(self, "}", depth_lvl);
+            }
+            Call { fun, args, ty, from_hir_call, fn_span } => {
+                print_indented!(self, "Call {", depth_lvl);
+                print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 1);
+                print_indented!(self, format!("from_hir_call: {}", from_hir_call), depth_lvl + 1);
+                print_indented!(self, format!("fn_span: {:?}", fn_span), depth_lvl + 1);
+                print_indented!(self, "fun:", depth_lvl + 1);
+                self.print_expr(*fun, depth_lvl + 2);
+
+                if args.len() > 0 {
+                    print_indented!(self, "args: [", depth_lvl + 1);
+                    for arg in args.iter() {
+                        self.print_expr(*arg, depth_lvl + 2);
+                    }
+                    print_indented!(self, "]", depth_lvl + 1);
+                } else {
+                    print_indented!(self, "args: []", depth_lvl + 1);
+                }
+
+                print_indented!(self, "}", depth_lvl);
+            }
+            Deref { arg } => {
+                print_indented!(self, "Deref {", depth_lvl);
+                self.print_expr(*arg, depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Binary { op, lhs, rhs } => {
+                print_indented!(self, "Binary {", depth_lvl);
+                print_indented!(self, format!("op: {:?}", op), depth_lvl + 1);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "rhs:", depth_lvl + 1);
+                self.print_expr(*rhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            LogicalOp { op, lhs, rhs } => {
+                print_indented!(self, "LogicalOp {", depth_lvl);
+                print_indented!(self, format!("op: {:?}", op), depth_lvl + 1);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "rhs:", depth_lvl + 1);
+                self.print_expr(*rhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Unary { op, arg } => {
+                print_indented!(self, "Unary {", depth_lvl);
+                print_indented!(self, format!("op: {:?}", op), depth_lvl + 1);
+                print_indented!(self, "arg:", depth_lvl + 1);
+                self.print_expr(*arg, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Cast { source } => {
+                print_indented!(self, "Cast {", depth_lvl);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Use { source } => {
+                print_indented!(self, "Use {", depth_lvl);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            NeverToAny { source } => {
+                print_indented!(self, "NeverToAny {", depth_lvl);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Pointer { cast, source } => {
+                print_indented!(self, "Pointer {", depth_lvl);
+                print_indented!(self, format!("cast: {:?}", cast), depth_lvl + 1);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Loop { body } => {
+                print_indented!(self, "Loop (", depth_lvl);
+                print_indented!(self, "body:", depth_lvl + 1);
+                self.print_expr(*body, depth_lvl + 2);
+                print_indented!(self, ")", depth_lvl);
+            }
+            Let { expr, pat } => {
+                print_indented!(self, "Let {", depth_lvl);
+                print_indented!(self, "expr:", depth_lvl + 1);
+                self.print_expr(*expr, depth_lvl + 2);
+                print_indented!(self, format!("pat: {:?}", pat), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Match { scrutinee, arms } => {
+                print_indented!(self, "Match {", depth_lvl);
+                print_indented!(self, "scrutinee:", depth_lvl + 1);
+                self.print_expr(*scrutinee, depth_lvl + 2);
+
+                print_indented!(self, "arms: [", depth_lvl + 1);
+                for arm_id in arms.iter() {
+                    self.print_arm(*arm_id, depth_lvl + 2);
+                }
+                print_indented!(self, "]", depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Block { block } => self.print_block(*block, depth_lvl),
+            Assign { lhs, rhs } => {
+                print_indented!(self, "Assign {", depth_lvl);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "rhs:", depth_lvl + 1);
+                self.print_expr(*rhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            AssignOp { op, lhs, rhs } => {
+                print_indented!(self, "AssignOp {", depth_lvl);
+                print_indented!(self, format!("op: {:?}", op), depth_lvl + 1);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "rhs:", depth_lvl + 1);
+                self.print_expr(*rhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Field { lhs, variant_index, name } => {
+                print_indented!(self, "Field {", depth_lvl);
+                print_indented!(self, format!("variant_index: {:?}", variant_index), depth_lvl + 1);
+                print_indented!(self, format!("name: {:?}", name), depth_lvl + 1);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Index { lhs, index } => {
+                print_indented!(self, "Index {", depth_lvl);
+                print_indented!(self, format!("index: {:?}", index), depth_lvl + 1);
+                print_indented!(self, "lhs:", depth_lvl + 1);
+                self.print_expr(*lhs, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            VarRef { id } => {
+                print_indented!(self, "VarRef {", depth_lvl);
+                print_indented!(self, format!("id: {:?}", id), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            UpvarRef { closure_def_id, var_hir_id } => {
+                print_indented!(self, "UpvarRef {", depth_lvl);
+                print_indented!(
+                    self,
+                    format!("closure_def_id: {:?}", closure_def_id),
+                    depth_lvl + 1
+                );
+                print_indented!(self, format!("var_hir_id: {:?}", var_hir_id), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Borrow { borrow_kind, arg } => {
+                print_indented!(self, "Borrow (", depth_lvl);
+                print_indented!(self, format!("borrow_kind: {:?}", borrow_kind), depth_lvl + 1);
+                print_indented!(self, "arg:", depth_lvl + 1);
+                self.print_expr(*arg, depth_lvl + 2);
+                print_indented!(self, ")", depth_lvl);
+            }
+            AddressOf { mutability, arg } => {
+                print_indented!(self, "AddressOf {", depth_lvl);
+                print_indented!(self, format!("mutability: {:?}", mutability), depth_lvl + 1);
+                print_indented!(self, "arg:", depth_lvl + 1);
+                self.print_expr(*arg, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Break { label, value } => {
+                print_indented!(self, "Break (", depth_lvl);
+                print_indented!(self, format!("label: {:?}", label), depth_lvl + 1);
+
+                if let Some(value) = value {
+                    print_indented!(self, "value:", depth_lvl + 1);
+                    self.print_expr(*value, depth_lvl + 2);
+                }
+
+                print_indented!(self, ")", depth_lvl);
+            }
+            Continue { label } => {
+                print_indented!(self, "Continue {", depth_lvl);
+                print_indented!(self, format!("label: {:?}", label), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Return { value } => {
+                print_indented!(self, "Return {", depth_lvl);
+                print_indented!(self, "value:", depth_lvl + 1);
+
+                if let Some(value) = value {
+                    self.print_expr(*value, depth_lvl + 2);
+                }
+
+                print_indented!(self, "}", depth_lvl);
+            }
+            ConstBlock { did, substs } => {
+                print_indented!(self, "ConstBlock {", depth_lvl);
+                print_indented!(self, format!("did: {:?}", did), depth_lvl + 1);
+                print_indented!(self, format!("substs: {:?}", substs), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Repeat { value, count } => {
+                print_indented!(self, "Repeat {", depth_lvl);
+                print_indented!(self, format!("count: {:?}", count), depth_lvl + 1);
+                print_indented!(self, "value:", depth_lvl + 1);
+                self.print_expr(*value, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Array { fields } => {
+                print_indented!(self, "Array {", depth_lvl);
+                print_indented!(self, "fields: [", depth_lvl + 1);
+                for field_id in fields.iter() {
+                    self.print_expr(*field_id, depth_lvl + 2);
+                }
+                print_indented!(self, "]", depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Tuple { fields } => {
+                print_indented!(self, "Tuple {", depth_lvl);
+                print_indented!(self, "fields: [", depth_lvl + 1);
+                for field_id in fields.iter() {
+                    self.print_expr(*field_id, depth_lvl + 2);
+                }
+                print_indented!(self, "]", depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Adt(adt_expr) => {
+                print_indented!(self, "Adt {", depth_lvl);
+                self.print_adt_expr(&**adt_expr, depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            PlaceTypeAscription { source, user_ty } => {
+                print_indented!(self, "PlaceTypeAscription {", depth_lvl);
+                print_indented!(self, format!("user_ty: {:?}", user_ty), depth_lvl + 1);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            ValueTypeAscription { source, user_ty } => {
+                print_indented!(self, "ValueTypeAscription {", depth_lvl);
+                print_indented!(self, format!("user_ty: {:?}", user_ty), depth_lvl + 1);
+                print_indented!(self, "source:", depth_lvl + 1);
+                self.print_expr(*source, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Closure(closure_expr) => {
+                print_indented!(self, "Closure {", depth_lvl);
+                print_indented!(self, "closure_expr:", depth_lvl + 1);
+                self.print_closure_expr(&**closure_expr, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Literal { lit, neg } => {
+                print_indented!(
+                    self,
+                    format!("Literal( lit: {:?}, neg: {:?})\n", lit, neg),
+                    depth_lvl
+                );
+            }
+            NonHirLiteral { lit, user_ty } => {
+                print_indented!(self, "NonHirLiteral {", depth_lvl);
+                print_indented!(self, format!("lit: {:?}", lit), depth_lvl + 1);
+                print_indented!(self, format!("user_ty: {:?}", user_ty), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            ZstLiteral { user_ty } => {
+                print_indented!(self, format!("ZstLiteral(user_ty: {:?})", user_ty), depth_lvl);
+            }
+            NamedConst { def_id, substs, user_ty } => {
+                print_indented!(self, "NamedConst {", depth_lvl);
+                print_indented!(self, format!("def_id: {:?}", def_id), depth_lvl + 1);
+                print_indented!(self, format!("user_ty: {:?}", user_ty), depth_lvl + 1);
+                print_indented!(self, format!("substs: {:?}", substs), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            ConstParam { param, def_id } => {
+                print_indented!(self, "ConstParam {", depth_lvl);
+                print_indented!(self, format!("def_id: {:?}", def_id), depth_lvl + 1);
+                print_indented!(self, format!("param: {:?}", param), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            StaticRef { alloc_id, ty, def_id } => {
+                print_indented!(self, "StaticRef {", depth_lvl);
+                print_indented!(self, format!("def_id: {:?}", def_id), depth_lvl + 1);
+                print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 1);
+                print_indented!(self, format!("alloc_id: {:?}", alloc_id), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            InlineAsm(expr) => {
+                print_indented!(self, "InlineAsm {", depth_lvl);
+                print_indented!(self, "expr:", depth_lvl + 1);
+                self.print_inline_asm_expr(&**expr, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+            ThreadLocalRef(def_id) => {
+                print_indented!(self, "ThreadLocalRef {", depth_lvl);
+                print_indented!(self, format!("def_id: {:?}", def_id), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl);
+            }
+            Yield { value } => {
+                print_indented!(self, "Yield {", depth_lvl);
+                print_indented!(self, "value:", depth_lvl + 1);
+                self.print_expr(*value, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl);
+            }
+        }
+    }
+
+    fn print_adt_expr(&mut self, adt_expr: &AdtExpr<'tcx>, depth_lvl: usize) {
+        print_indented!(self, "adt_def:", depth_lvl);
+        self.print_adt_def(adt_expr.adt_def, depth_lvl + 1);
+        print_indented!(
+            self,
+            format!("variant_index: {:?}", adt_expr.variant_index),
+            depth_lvl + 1
+        );
+        print_indented!(self, format!("substs: {:?}", adt_expr.substs), depth_lvl + 1);
+        print_indented!(self, format!("user_ty: {:?}", adt_expr.user_ty), depth_lvl + 1);
+
+        for (i, field_expr) in adt_expr.fields.iter().enumerate() {
+            print_indented!(self, format!("field {}:", i), depth_lvl + 1);
+            self.print_expr(field_expr.expr, depth_lvl + 2);
+        }
+
+        if let Some(ref base) = adt_expr.base {
+            print_indented!(self, "base:", depth_lvl + 1);
+            self.print_fru_info(base, depth_lvl + 2);
+        } else {
+            print_indented!(self, "base: None", depth_lvl + 1);
+        }
+    }
+
+    fn print_adt_def(&mut self, adt_def: ty::AdtDef<'tcx>, depth_lvl: usize) {
+        print_indented!(self, "AdtDef {", depth_lvl);
+        print_indented!(self, format!("did: {:?}", adt_def.did()), depth_lvl + 1);
+        print_indented!(self, format!("variants: {:?}", adt_def.variants()), depth_lvl + 1);
+        print_indented!(self, format!("flags: {:?}", adt_def.flags()), depth_lvl + 1);
+        print_indented!(self, format!("repr: {:?}", adt_def.repr()), depth_lvl + 1);
+    }
+
+    fn print_fru_info(&mut self, fru_info: &FruInfo<'tcx>, depth_lvl: usize) {
+        print_indented!(self, "FruInfo {", depth_lvl);
+        print_indented!(self, "base: ", depth_lvl + 1);
+        self.print_expr(fru_info.base, depth_lvl + 2);
+        print_indented!(self, "field_types: [", depth_lvl + 1);
+        for ty in fru_info.field_types.iter() {
+            print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 2);
+        }
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_arm(&mut self, arm_id: ArmId, depth_lvl: usize) {
+        print_indented!(self, "Arm {", depth_lvl);
+
+        let arm = &self.thir.arms[arm_id];
+        let Arm { pattern, guard, body, lint_level, scope, span } = arm;
+
+        print_indented!(self, "pattern: ", depth_lvl + 1);
+        self.print_pat(pattern, depth_lvl + 2);
+
+        if let Some(guard) = guard {
+            print_indented!(self, "guard: ", depth_lvl + 1);
+            self.print_guard(guard, depth_lvl + 2);
+        } else {
+            print_indented!(self, "guard: None", depth_lvl + 1);
+        }
+
+        print_indented!(self, "body: ", depth_lvl + 1);
+        self.print_expr(*body, depth_lvl + 2);
+        print_indented!(self, format!("lint_level: {:?}", lint_level), depth_lvl + 1);
+        print_indented!(self, format!("scope: {:?}", scope), depth_lvl + 1);
+        print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_pat(&mut self, pat: &Box<Pat<'tcx>>, depth_lvl: usize) {
+        let Pat { ty, span, kind } = &**pat;
+
+        print_indented!(self, "Pat: {", depth_lvl);
+        print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 1);
+        print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+        self.print_pat_kind(kind, depth_lvl + 1);
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_pat_kind(&mut self, pat_kind: &PatKind<'tcx>, depth_lvl: usize) {
+        print_indented!(self, "kind: PatKind {", depth_lvl);
+
+        match pat_kind {
+            PatKind::Wild => {
+                print_indented!(self, "Wild", depth_lvl + 1);
+            }
+            PatKind::AscribeUserType { ascription, subpattern } => {
+                print_indented!(self, "AscribeUserType: {", depth_lvl + 1);
+                print_indented!(self, format!("ascription: {:?}", ascription), depth_lvl + 2);
+                print_indented!(self, "subpattern: ", depth_lvl + 2);
+                self.print_pat(subpattern, depth_lvl + 3);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Binding { mutability, name, mode, var, ty, subpattern, is_primary } => {
+                print_indented!(self, "Binding {", depth_lvl + 1);
+                print_indented!(self, format!("mutability: {:?}", mutability), depth_lvl + 2);
+                print_indented!(self, format!("name: {:?}", name), depth_lvl + 2);
+                print_indented!(self, format!("mode: {:?}", mode), depth_lvl + 2);
+                print_indented!(self, format!("var: {:?}", var), depth_lvl + 2);
+                print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 2);
+                print_indented!(self, format!("is_primary: {:?}", is_primary), depth_lvl + 2);
+
+                if let Some(subpattern) = subpattern {
+                    print_indented!(self, "subpattern: Some( ", depth_lvl + 2);
+                    self.print_pat(subpattern, depth_lvl + 3);
+                    print_indented!(self, ")", depth_lvl + 2);
+                } else {
+                    print_indented!(self, "subpattern: None", depth_lvl + 2);
+                }
+
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Variant { adt_def, substs, variant_index, subpatterns } => {
+                print_indented!(self, "Variant {", depth_lvl + 1);
+                print_indented!(self, "adt_def: ", depth_lvl + 2);
+                self.print_adt_def(*adt_def, depth_lvl + 3);
+                print_indented!(self, format!("substs: {:?}", substs), depth_lvl + 2);
+                print_indented!(self, format!("variant_index: {:?}", variant_index), depth_lvl + 2);
+
+                if subpatterns.len() > 0 {
+                    print_indented!(self, "subpatterns: [", depth_lvl + 2);
+                    for field_pat in subpatterns.iter() {
+                        self.print_pat(&field_pat.pattern, depth_lvl + 3);
+                    }
+                    print_indented!(self, "]", depth_lvl + 2);
+                } else {
+                    print_indented!(self, "subpatterns: []", depth_lvl + 2);
+                }
+
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Leaf { subpatterns } => {
+                print_indented!(self, "Leaf { ", depth_lvl + 1);
+                print_indented!(self, "subpatterns: [", depth_lvl + 2);
+                for field_pat in subpatterns.iter() {
+                    self.print_pat(&field_pat.pattern, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Deref { subpattern } => {
+                print_indented!(self, "Deref { ", depth_lvl + 1);
+                print_indented!(self, "subpattern: ", depth_lvl + 2);
+                self.print_pat(subpattern, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Constant { value } => {
+                print_indented!(self, "Constant {", depth_lvl + 1);
+                print_indented!(self, format!("value: {:?}", value), depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Range(pat_range) => {
+                print_indented!(self, format!("Range ( {:?} )", pat_range), depth_lvl + 1);
+            }
+            PatKind::Slice { prefix, slice, suffix } => {
+                print_indented!(self, "Slice {", depth_lvl + 1);
+
+                print_indented!(self, "prefix: [", depth_lvl + 2);
+                for prefix_pat in prefix.iter() {
+                    self.print_pat(prefix_pat, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+
+                if let Some(slice) = slice {
+                    print_indented!(self, "slice: ", depth_lvl + 2);
+                    self.print_pat(slice, depth_lvl + 3);
+                }
+
+                print_indented!(self, "suffix: [", depth_lvl + 2);
+                for suffix_pat in suffix.iter() {
+                    self.print_pat(suffix_pat, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Array { prefix, slice, suffix } => {
+                print_indented!(self, "Array {", depth_lvl + 1);
+
+                print_indented!(self, "prefix: [", depth_lvl + 2);
+                for prefix_pat in prefix.iter() {
+                    self.print_pat(prefix_pat, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+
+                if let Some(slice) = slice {
+                    print_indented!(self, "slice: ", depth_lvl + 2);
+                    self.print_pat(slice, depth_lvl + 3);
+                }
+
+                print_indented!(self, "suffix: [", depth_lvl + 2);
+                for suffix_pat in suffix.iter() {
+                    self.print_pat(suffix_pat, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            PatKind::Or { pats } => {
+                print_indented!(self, "Or {", depth_lvl + 1);
+                print_indented!(self, "pats: [", depth_lvl + 2);
+                for pat in pats.iter() {
+                    self.print_pat(pat, depth_lvl + 3);
+                }
+                print_indented!(self, "]", depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_guard(&mut self, guard: &Guard<'tcx>, depth_lvl: usize) {
+        print_indented!(self, "Guard {", depth_lvl);
+
+        match guard {
+            Guard::If(expr_id) => {
+                print_indented!(self, "If (", depth_lvl + 1);
+                self.print_expr(*expr_id, depth_lvl + 2);
+                print_indented!(self, ")", depth_lvl + 1);
+            }
+            Guard::IfLet(pat, expr_id) => {
+                print_indented!(self, "IfLet (", depth_lvl + 1);
+                self.print_pat(pat, depth_lvl + 2);
+                print_indented!(self, ",", depth_lvl + 1);
+                self.print_expr(*expr_id, depth_lvl + 2);
+                print_indented!(self, ")", depth_lvl + 1);
+            }
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_closure_expr(&mut self, expr: &ClosureExpr<'tcx>, depth_lvl: usize) {
+        let ClosureExpr { closure_id, substs, upvars, movability, fake_reads } = expr;
+
+        print_indented!(self, "ClosureExpr {", depth_lvl);
+        print_indented!(self, format!("closure_id: {:?}", closure_id), depth_lvl + 1);
+        print_indented!(self, format!("substs: {:?}", substs), depth_lvl + 1);
+
+        if upvars.len() > 0 {
+            print_indented!(self, "upvars: [", depth_lvl + 1);
+            for upvar in upvars.iter() {
+                self.print_expr(*upvar, depth_lvl + 2);
+                print_indented!(self, ",", depth_lvl + 1);
+            }
+            print_indented!(self, "]", depth_lvl + 1);
+        } else {
+            print_indented!(self, "upvars: []", depth_lvl + 1);
+        }
+
+        print_indented!(self, format!("movability: {:?}", movability), depth_lvl + 1);
+
+        if fake_reads.len() > 0 {
+            print_indented!(self, "fake_reads: [", depth_lvl + 1);
+            for (fake_read_expr, cause, hir_id) in fake_reads.iter() {
+                print_indented!(self, "(", depth_lvl + 2);
+                self.print_expr(*fake_read_expr, depth_lvl + 3);
+                print_indented!(self, ",", depth_lvl + 2);
+                print_indented!(self, format!("cause: {:?}", cause), depth_lvl + 3);
+                print_indented!(self, ",", depth_lvl + 2);
+                print_indented!(self, format!("hir_id: {:?}", hir_id), depth_lvl + 3);
+                print_indented!(self, "),", depth_lvl + 2);
+            }
+            print_indented!(self, "]", depth_lvl + 1);
+        } else {
+            print_indented!(self, "fake_reads: []", depth_lvl + 1);
+        }
+
+        print_indented!(self, "}", depth_lvl);
+    }
+
+    fn print_inline_asm_expr(&mut self, expr: &InlineAsmExpr<'tcx>, depth_lvl: usize) {
+        let InlineAsmExpr { template, operands, options, line_spans } = expr;
+
+        print_indented!(self, "InlineAsmExpr {", depth_lvl);
+
+        print_indented!(self, "template: [", depth_lvl + 1);
+        for template_piece in template.iter() {
+            print_indented!(self, format!("{:?}", template_piece), depth_lvl + 2);
+        }
+        print_indented!(self, "]", depth_lvl + 1);
+
+        print_indented!(self, "operands: [", depth_lvl + 1);
+        for operand in operands.iter() {
+            self.print_inline_operand(operand, depth_lvl + 2);
+        }
+        print_indented!(self, "]", depth_lvl + 1);
+
+        print_indented!(self, format!("options: {:?}", options), depth_lvl + 1);
+        print_indented!(self, format!("line_spans: {:?}", line_spans), depth_lvl + 1);
+    }
+
+    fn print_inline_operand(&mut self, operand: &InlineAsmOperand<'tcx>, depth_lvl: usize) {
+        match operand {
+            InlineAsmOperand::In { reg, expr } => {
+                print_indented!(self, "InlineAsmOperand::In {", depth_lvl);
+                print_indented!(self, format!("reg: {:?}", reg), depth_lvl + 1);
+                print_indented!(self, "expr: ", depth_lvl + 1);
+                self.print_expr(*expr, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::Out { reg, late, expr } => {
+                print_indented!(self, "InlineAsmOperand::Out {", depth_lvl);
+                print_indented!(self, format!("reg: {:?}", reg), depth_lvl + 1);
+                print_indented!(self, format!("late: {:?}", late), depth_lvl + 1);
+
+                if let Some(out) = expr {
+                    print_indented!(self, "place: Some( ", depth_lvl + 1);
+                    self.print_expr(*out, depth_lvl + 2);
+                    print_indented!(self, ")", depth_lvl + 1);
+                } else {
+                    print_indented!(self, "place: None", depth_lvl + 1);
+                }
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::InOut { reg, late, expr } => {
+                print_indented!(self, "InlineAsmOperand::InOut {", depth_lvl);
+                print_indented!(self, format!("reg: {:?}", reg), depth_lvl + 1);
+                print_indented!(self, format!("late: {:?}", late), depth_lvl + 1);
+                print_indented!(self, "expr: ", depth_lvl + 1);
+                self.print_expr(*expr, depth_lvl + 2);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::SplitInOut { reg, late, in_expr, out_expr } => {
+                print_indented!(self, "InlineAsmOperand::SplitInOut {", depth_lvl);
+                print_indented!(self, format!("reg: {:?}", reg), depth_lvl + 1);
+                print_indented!(self, format!("late: {:?}", late), depth_lvl + 1);
+                print_indented!(self, "in_expr: ", depth_lvl + 1);
+                self.print_expr(*in_expr, depth_lvl + 2);
+
+                if let Some(out_expr) = out_expr {
+                    print_indented!(self, "out_expr: Some( ", depth_lvl + 1);
+                    self.print_expr(*out_expr, depth_lvl + 2);
+                    print_indented!(self, ")", depth_lvl + 1);
+                } else {
+                    print_indented!(self, "out_expr: None", depth_lvl + 1);
+                }
+
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::Const { value, span } => {
+                print_indented!(self, "InlineAsmOperand::Const {", depth_lvl);
+                print_indented!(self, format!("value: {:?}", value), depth_lvl + 1);
+                print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::SymFn { value, span } => {
+                print_indented!(self, "InlineAsmOperand::SymFn {", depth_lvl);
+                print_indented!(self, format!("value: {:?}", *value), depth_lvl + 1);
+                print_indented!(self, format!("span: {:?}", span), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+            InlineAsmOperand::SymStatic { def_id } => {
+                print_indented!(self, "InlineAsmOperand::SymStatic {", depth_lvl);
+                print_indented!(self, format!("def_id: {:?}", def_id), depth_lvl + 1);
+                print_indented!(self, "}", depth_lvl + 1);
+            }
+        }
+    }
+}
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index d00b26a5a3d..cf3dce48064 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -18,7 +18,8 @@ use crate::ty::{self, AdtKind, Ty, TyCtxt};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
+use rustc_span::def_id::{LocalDefId, CRATE_DEF_ID};
 use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 use smallvec::SmallVec;
@@ -36,7 +37,7 @@ pub use self::chalk::{ChalkEnvironmentAndGoal, RustInterner as ChalkRustInterner
 
 /// Depending on the stage of compilation, we want projection to be
 /// more or less conservative.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, HashStable)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, HashStable, Encodable, Decodable)]
 pub enum Reveal {
     /// At type-checking time, we refuse to project any associated
     /// type that is marked `default`. Non-`default` ("final") types
@@ -89,7 +90,8 @@ pub enum Reveal {
 ///
 /// We do not want to intern this as there are a lot of obligation causes which
 /// only live for a short period of time.
-#[derive(Clone, Debug, PartialEq, Eq, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub struct ObligationCause<'tcx> {
     pub span: Span,
 
@@ -99,7 +101,7 @@ pub struct ObligationCause<'tcx> {
     /// (in particular, closures can add new assumptions). See the
     /// field `region_obligations` of the `FulfillmentContext` for more
     /// information.
-    pub body_id: hir::HirId,
+    pub body_id: LocalDefId,
 
     code: InternedObligationCauseCode<'tcx>,
 }
@@ -120,13 +122,13 @@ impl<'tcx> ObligationCause<'tcx> {
     #[inline]
     pub fn new(
         span: Span,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         code: ObligationCauseCode<'tcx>,
     ) -> ObligationCause<'tcx> {
         ObligationCause { span, body_id, code: code.into() }
     }
 
-    pub fn misc(span: Span, body_id: hir::HirId) -> ObligationCause<'tcx> {
+    pub fn misc(span: Span, body_id: LocalDefId) -> ObligationCause<'tcx> {
         ObligationCause::new(span, body_id, MiscObligation)
     }
 
@@ -137,7 +139,7 @@ impl<'tcx> ObligationCause<'tcx> {
 
     #[inline(always)]
     pub fn dummy_with_span(span: Span) -> ObligationCause<'tcx> {
-        ObligationCause { span, body_id: hir::CRATE_HIR_ID, code: Default::default() }
+        ObligationCause { span, body_id: CRATE_DEF_ID, code: Default::default() }
     }
 
     pub fn span(&self) -> Span {
@@ -196,14 +198,16 @@ impl<'tcx> ObligationCause<'tcx> {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub struct UnifyReceiverContext<'tcx> {
     pub assoc_item: ty::AssocItem,
     pub param_env: ty::ParamEnv<'tcx>,
     pub substs: SubstsRef<'tcx>,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash, Lift, Default)]
+#[derive(Clone, PartialEq, Eq, Hash, Lift, Default, HashStable)]
+#[derive(TypeVisitable, TypeFoldable, TyEncodable, TyDecodable)]
 pub struct InternedObligationCauseCode<'tcx> {
     /// `None` for `ObligationCauseCode::MiscObligation` (a common case, occurs ~60% of
     /// the time). `Some` otherwise.
@@ -238,7 +242,8 @@ impl<'tcx> std::ops::Deref for InternedObligationCauseCode<'tcx> {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub enum ObligationCauseCode<'tcx> {
     /// Not well classified or should be obvious from the span.
     MiscObligation,
@@ -446,7 +451,8 @@ pub enum ObligationCauseCode<'tcx> {
 /// This information is used to obtain an `hir::Ty`, which
 /// we can walk in order to obtain precise spans for any
 /// 'nested' types (e.g. `Foo` in `Option<Foo>`).
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, Encodable, Decodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub enum WellFormedLoc {
     /// Use the type of the provided definition.
     Ty(LocalDefId),
@@ -463,7 +469,8 @@ pub enum WellFormedLoc {
     },
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub struct ImplDerivedObligationCause<'tcx> {
     pub derived: DerivedObligationCause<'tcx>,
     pub impl_def_id: DefId,
@@ -517,7 +524,8 @@ impl<'tcx> ty::Lift<'tcx> for StatementAsExpression {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub struct MatchExpressionArmCause<'tcx> {
     pub arm_block_id: Option<hir::HirId>,
     pub arm_ty: Ty<'tcx>,
@@ -533,7 +541,7 @@ pub struct MatchExpressionArmCause<'tcx> {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-#[derive(Lift, TypeFoldable, TypeVisitable)]
+#[derive(Lift, TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)]
 pub struct IfExpressionCause<'tcx> {
     pub then_id: hir::HirId,
     pub else_id: hir::HirId,
@@ -543,7 +551,8 @@ pub struct IfExpressionCause<'tcx> {
     pub opt_suggest_box_span: Option<Span>,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Lift, HashStable, TyEncodable, TyDecodable)]
+#[derive(TypeVisitable, TypeFoldable)]
 pub struct DerivedObligationCause<'tcx> {
     /// The trait predicate of the parent obligation that led to the
     /// current obligation. Note that only trait obligations lead to
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index d3d667f6840..099a7845118 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -188,7 +188,7 @@ impl<'tcx> AdtDef<'tcx> {
     }
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, TyEncodable, TyDecodable)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, HashStable, TyEncodable, TyDecodable)]
 pub enum AdtKind {
     Struct,
     Union,
diff --git a/compiler/rustc_middle/src/ty/assoc.rs b/compiler/rustc_middle/src/ty/assoc.rs
index bb7fba3ee71..71cecfb558f 100644
--- a/compiler/rustc_middle/src/ty/assoc.rs
+++ b/compiler/rustc_middle/src/ty/assoc.rs
@@ -79,7 +79,7 @@ impl AssocItem {
                 // late-bound regions, and we don't want method signatures to show up
                 // `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
                 // regions just fine, showing `fn(&MyType)`.
-                tcx.fn_sig(self.def_id).skip_binder().to_string()
+                tcx.fn_sig(self.def_id).subst_identity().skip_binder().to_string()
             }
             ty::AssocKind::Type => format!("type {};", self.name),
             ty::AssocKind::Const => {
@@ -130,7 +130,7 @@ impl std::fmt::Display for AssocKind {
 /// done only on items with the same name.
 #[derive(Debug, Clone, PartialEq, HashStable)]
 pub struct AssocItems<'tcx> {
-    pub(super) items: SortedIndexMultiMap<u32, Symbol, &'tcx ty::AssocItem>,
+    items: SortedIndexMultiMap<u32, Symbol, &'tcx ty::AssocItem>,
 }
 
 impl<'tcx> AssocItems<'tcx> {
diff --git a/compiler/rustc_middle/src/ty/codec.rs b/compiler/rustc_middle/src/ty/codec.rs
index 8cc8286c1db..b9a1e23879c 100644
--- a/compiler/rustc_middle/src/ty/codec.rs
+++ b/compiler/rustc_middle/src/ty/codec.rs
@@ -157,6 +157,14 @@ impl<'tcx, E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<E> for AllocId {
     }
 }
 
+impl<'tcx, E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<E> for ty::ParamEnv<'tcx> {
+    fn encode(&self, e: &mut E) {
+        self.caller_bounds().encode(e);
+        self.reveal().encode(e);
+        self.constness().encode(e);
+    }
+}
+
 #[inline]
 fn decode_arena_allocable<
     'tcx,
@@ -280,8 +288,17 @@ impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for ty::SymbolName<'tcx>
     }
 }
 
+impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for ty::ParamEnv<'tcx> {
+    fn decode(d: &mut D) -> Self {
+        let caller_bounds = Decodable::decode(d);
+        let reveal = Decodable::decode(d);
+        let constness = Decodable::decode(d);
+        ty::ParamEnv::new(caller_bounds, reveal, constness)
+    }
+}
+
 macro_rules! impl_decodable_via_ref {
-    ($($t:ty),+) => {
+    ($($t:ty,)+) => {
         $(impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for $t {
             fn decode(decoder: &mut D) -> Self {
                 RefDecodable::decode(decoder)
@@ -373,6 +390,15 @@ impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> RefDecodable<'tcx, D> for ty::List<ty
     }
 }
 
+impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> RefDecodable<'tcx, D> for ty::List<ty::Predicate<'tcx>> {
+    fn decode(decoder: &mut D) -> &'tcx Self {
+        let len = decoder.read_usize();
+        let predicates: Vec<_> =
+            (0..len).map::<ty::Predicate<'tcx>, _>(|_| Decodable::decode(decoder)).collect();
+        decoder.interner().intern_predicates(&predicates)
+    }
+}
+
 impl_decodable_via_ref! {
     &'tcx ty::TypeckResults<'tcx>,
     &'tcx ty::List<Ty<'tcx>>,
@@ -382,7 +408,8 @@ impl_decodable_via_ref! {
     &'tcx mir::UnsafetyCheckResult,
     &'tcx mir::BorrowCheckResult<'tcx>,
     &'tcx mir::coverage::CodeRegion,
-    &'tcx ty::List<ty::BoundVariableKind>
+    &'tcx ty::List<ty::BoundVariableKind>,
+    &'tcx ty::List<ty::Predicate<'tcx>>,
 }
 
 #[macro_export]
@@ -519,6 +546,8 @@ macro_rules! impl_binder_encode_decode {
 impl_binder_encode_decode! {
     &'tcx ty::List<Ty<'tcx>>,
     ty::FnSig<'tcx>,
+    ty::Predicate<'tcx>,
+    ty::TraitPredicate<'tcx>,
     ty::ExistentialPredicate<'tcx>,
     ty::TraitRef<'tcx>,
     Vec<ty::GeneratorInteriorTypeCause<'tcx>>,
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index ce04d8d21f4..b63b9e754cf 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2,6 +2,8 @@
 
 #![allow(rustc::usage_of_ty_tykind)]
 
+pub mod tls;
+
 use crate::arena::Arena;
 use crate::dep_graph::{DepGraph, DepKindStruct};
 use crate::infer::canonical::{CanonicalVarInfo, CanonicalVarInfos};
@@ -75,6 +77,8 @@ use std::iter;
 use std::mem;
 use std::ops::{Bound, Deref};
 
+const TINY_CONST_EVAL_LIMIT: Limit = Limit(20);
+
 pub trait OnDiskCache<'tcx>: rustc_data_structures::sync::Sync {
     /// Creates a new `OnDiskCache` instance from the serialized data in `data`.
     fn new(sess: &'tcx Session, data: Mmap, start_pos: usize) -> Self
@@ -997,6 +1001,30 @@ impl<'tcx> TyCtxt<'tcx> {
         v.0
     }
 
+    /// Given a `DefId` for an `fn`, return all the `dyn` and `impl` traits in its return type and associated alias span when type alias is used
+    pub fn return_type_impl_or_dyn_traits_with_type_alias(
+        self,
+        scope_def_id: LocalDefId,
+    ) -> Option<(Vec<&'tcx hir::Ty<'tcx>>, Span)> {
+        let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id);
+        let mut v = TraitObjectVisitor(vec![], self.hir());
+        // when the return type is a type alias
+        if let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) = self.hir().fn_decl_by_hir_id(hir_id)
+            && let hir::TyKind::Path(hir::QPath::Resolved(
+                None,
+                hir::Path { res: hir::def::Res::Def(DefKind::TyAlias, def_id), .. }, )) = hir_output.kind
+            && let Some(local_id) = def_id.as_local()
+            && let Some(alias_ty) = self.hir().get_by_def_id(local_id).alias_ty() // it is type alias
+            && let Some(alias_generics) = self.hir().get_by_def_id(local_id).generics()
+        {
+            v.visit_ty(alias_ty);
+            if !v.0.is_empty() {
+                return Some((v.0, alias_generics.span));
+            }
+        }
+        return None;
+    }
+
     pub fn return_type_impl_trait(self, scope_def_id: LocalDefId) -> Option<(Ty<'tcx>, Span)> {
         // `type_of()` will fail on these (#55796, #86483), so only allow `fn`s or closures.
         match self.hir().get_by_def_id(scope_def_id) {
@@ -1078,7 +1106,11 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn const_eval_limit(self) -> Limit {
-        self.limits(()).const_eval_limit
+        if self.sess.opts.unstable_opts.tiny_const_eval_limit {
+            TINY_CONST_EVAL_LIMIT
+        } else {
+            self.limits(()).const_eval_limit
+        }
     }
 
     pub fn all_traits(self) -> impl Iterator<Item = DefId> + 'tcx {
@@ -1188,178 +1220,6 @@ CloneLiftImpls! { for<'tcx> {
     Constness, traits::WellFormedLoc, ImplPolarity, crate::mir::ReturnConstraint,
 } }
 
-pub mod tls {
-    use super::{ptr_eq, GlobalCtxt, TyCtxt};
-
-    use crate::dep_graph::TaskDepsRef;
-    use crate::ty::query;
-    use rustc_data_structures::sync::{self, Lock};
-    use rustc_errors::Diagnostic;
-    use std::mem;
-    use thin_vec::ThinVec;
-
-    #[cfg(not(parallel_compiler))]
-    use std::cell::Cell;
-
-    #[cfg(parallel_compiler)]
-    use rustc_rayon_core as rayon_core;
-
-    /// This is the implicit state of rustc. It contains the current
-    /// `TyCtxt` and query. It is updated when creating a local interner or
-    /// executing a new query. Whenever there's a `TyCtxt` value available
-    /// you should also have access to an `ImplicitCtxt` through the functions
-    /// in this module.
-    #[derive(Clone)]
-    pub struct ImplicitCtxt<'a, 'tcx> {
-        /// The current `TyCtxt`.
-        pub tcx: TyCtxt<'tcx>,
-
-        /// The current query job, if any. This is updated by `JobOwner::start` in
-        /// `ty::query::plumbing` when executing a query.
-        pub query: Option<query::QueryJobId>,
-
-        /// Where to store diagnostics for the current query job, if any.
-        /// This is updated by `JobOwner::start` in `ty::query::plumbing` when executing a query.
-        pub diagnostics: Option<&'a Lock<ThinVec<Diagnostic>>>,
-
-        /// Used to prevent queries from calling too deeply.
-        pub query_depth: usize,
-
-        /// The current dep graph task. This is used to add dependencies to queries
-        /// when executing them.
-        pub task_deps: TaskDepsRef<'a>,
-    }
-
-    impl<'a, 'tcx> ImplicitCtxt<'a, 'tcx> {
-        pub fn new(gcx: &'tcx GlobalCtxt<'tcx>) -> Self {
-            let tcx = TyCtxt { gcx };
-            ImplicitCtxt {
-                tcx,
-                query: None,
-                diagnostics: None,
-                query_depth: 0,
-                task_deps: TaskDepsRef::Ignore,
-            }
-        }
-    }
-
-    /// Sets Rayon's thread-local variable, which is preserved for Rayon jobs
-    /// to `value` during the call to `f`. It is restored to its previous value after.
-    /// This is used to set the pointer to the new `ImplicitCtxt`.
-    #[cfg(parallel_compiler)]
-    #[inline]
-    fn set_tlv<F: FnOnce() -> R, R>(value: usize, f: F) -> R {
-        rayon_core::tlv::with(value, f)
-    }
-
-    /// Gets Rayon's thread-local variable, which is preserved for Rayon jobs.
-    /// This is used to get the pointer to the current `ImplicitCtxt`.
-    #[cfg(parallel_compiler)]
-    #[inline]
-    pub fn get_tlv() -> usize {
-        rayon_core::tlv::get()
-    }
-
-    #[cfg(not(parallel_compiler))]
-    thread_local! {
-        /// A thread local variable that stores a pointer to the current `ImplicitCtxt`.
-        static TLV: Cell<usize> = const { Cell::new(0) };
-    }
-
-    /// Sets TLV to `value` during the call to `f`.
-    /// It is restored to its previous value after.
-    /// This is used to set the pointer to the new `ImplicitCtxt`.
-    #[cfg(not(parallel_compiler))]
-    #[inline]
-    fn set_tlv<F: FnOnce() -> R, R>(value: usize, f: F) -> R {
-        let old = get_tlv();
-        let _reset = rustc_data_structures::OnDrop(move || TLV.with(|tlv| tlv.set(old)));
-        TLV.with(|tlv| tlv.set(value));
-        f()
-    }
-
-    /// Gets the pointer to the current `ImplicitCtxt`.
-    #[cfg(not(parallel_compiler))]
-    #[inline]
-    fn get_tlv() -> usize {
-        TLV.with(|tlv| tlv.get())
-    }
-
-    /// Sets `context` as the new current `ImplicitCtxt` for the duration of the function `f`.
-    #[inline]
-    pub fn enter_context<'a, 'tcx, F, R>(context: &ImplicitCtxt<'a, 'tcx>, f: F) -> R
-    where
-        F: FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
-    {
-        set_tlv(context as *const _ as usize, || f(&context))
-    }
-
-    /// Allows access to the current `ImplicitCtxt` in a closure if one is available.
-    #[inline]
-    pub fn with_context_opt<F, R>(f: F) -> R
-    where
-        F: for<'a, 'tcx> FnOnce(Option<&ImplicitCtxt<'a, 'tcx>>) -> R,
-    {
-        let context = get_tlv();
-        if context == 0 {
-            f(None)
-        } else {
-            // We could get an `ImplicitCtxt` pointer from another thread.
-            // Ensure that `ImplicitCtxt` is `Sync`.
-            sync::assert_sync::<ImplicitCtxt<'_, '_>>();
-
-            unsafe { f(Some(&*(context as *const ImplicitCtxt<'_, '_>))) }
-        }
-    }
-
-    /// Allows access to the current `ImplicitCtxt`.
-    /// Panics if there is no `ImplicitCtxt` available.
-    #[inline]
-    pub fn with_context<F, R>(f: F) -> R
-    where
-        F: for<'a, 'tcx> FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
-    {
-        with_context_opt(|opt_context| f(opt_context.expect("no ImplicitCtxt stored in tls")))
-    }
-
-    /// Allows access to the current `ImplicitCtxt` whose tcx field is the same as the tcx argument
-    /// passed in. This means the closure is given an `ImplicitCtxt` with the same `'tcx` lifetime
-    /// as the `TyCtxt` passed in.
-    /// This will panic if you pass it a `TyCtxt` which is different from the current
-    /// `ImplicitCtxt`'s `tcx` field.
-    #[inline]
-    pub fn with_related_context<'tcx, F, R>(tcx: TyCtxt<'tcx>, f: F) -> R
-    where
-        F: FnOnce(&ImplicitCtxt<'_, 'tcx>) -> R,
-    {
-        with_context(|context| unsafe {
-            assert!(ptr_eq(context.tcx.gcx, tcx.gcx));
-            let context: &ImplicitCtxt<'_, '_> = mem::transmute(context);
-            f(context)
-        })
-    }
-
-    /// Allows access to the `TyCtxt` in the current `ImplicitCtxt`.
-    /// Panics if there is no `ImplicitCtxt` available.
-    #[inline]
-    pub fn with<F, R>(f: F) -> R
-    where
-        F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> R,
-    {
-        with_context(|context| f(context.tcx))
-    }
-
-    /// Allows access to the `TyCtxt` in the current `ImplicitCtxt`.
-    /// The closure is passed None if there is no `ImplicitCtxt` available.
-    #[inline]
-    pub fn with_opt<F, R>(f: F) -> R
-    where
-        F: for<'tcx> FnOnce(Option<TyCtxt<'tcx>>) -> R,
-    {
-        with_context_opt(|opt_context| f(opt_context.map(|context| context.tcx)))
-    }
-}
-
 macro_rules! sty_debug_print {
     ($fmt: expr, $ctxt: expr, $($variant: ident),*) => {{
         // Curious inner module to allow variant names to be used as
@@ -1452,6 +1312,7 @@ impl<'tcx> TyCtxt<'tcx> {
                     Placeholder,
                     Generator,
                     GeneratorWitness,
+                    GeneratorWitnessMIR,
                     Dynamic,
                     Closure,
                     Tuple,
@@ -1962,6 +1823,11 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     #[inline]
+    pub fn mk_generator_witness_mir(self, id: DefId, substs: SubstsRef<'tcx>) -> Ty<'tcx> {
+        self.mk_ty(GeneratorWitnessMIR(id, substs))
+    }
+
+    #[inline]
     pub fn mk_ty_var(self, v: TyVid) -> Ty<'tcx> {
         self.mk_ty_infer(TyVar(v))
     }
@@ -2297,10 +2163,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn is_late_bound(self, id: HirId) -> bool {
-        self.is_late_bound_map(id.owner.def_id).map_or(false, |set| {
-            let def_id = self.hir().local_def_id(id);
-            set.contains(&def_id)
-        })
+        self.is_late_bound_map(id.owner).map_or(false, |set| set.contains(&id.local_id))
     }
 
     pub fn late_bound_vars(self, id: HirId) -> &'tcx List<ty::BoundVariableKind> {
@@ -2392,12 +2255,6 @@ pub struct DeducedParamAttrs {
     pub read_only: bool,
 }
 
-// We are comparing types with different invariant lifetimes, so `ptr::eq`
-// won't work for us.
-fn ptr_eq<T, U>(t: *const T, u: *const U) -> bool {
-    t as *const () == u as *const ()
-}
-
 pub fn provide(providers: &mut ty::query::Providers) {
     providers.module_reexports =
         |tcx, id| tcx.resolutions(()).reexport_map.get(&id).map(|v| &v[..]);
diff --git a/compiler/rustc_middle/src/ty/context/tls.rs b/compiler/rustc_middle/src/ty/context/tls.rs
new file mode 100644
index 00000000000..71b025dc1be
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/context/tls.rs
@@ -0,0 +1,187 @@
+use super::{GlobalCtxt, TyCtxt};
+
+use crate::dep_graph::TaskDepsRef;
+use crate::ty::query;
+use rustc_data_structures::sync::{self, Lock};
+use rustc_errors::Diagnostic;
+use std::mem;
+use std::ptr;
+use thin_vec::ThinVec;
+
+/// This is the implicit state of rustc. It contains the current
+/// `TyCtxt` and query. It is updated when creating a local interner or
+/// executing a new query. Whenever there's a `TyCtxt` value available
+/// you should also have access to an `ImplicitCtxt` through the functions
+/// in this module.
+#[derive(Clone)]
+pub struct ImplicitCtxt<'a, 'tcx> {
+    /// The current `TyCtxt`.
+    pub tcx: TyCtxt<'tcx>,
+
+    /// The current query job, if any. This is updated by `JobOwner::start` in
+    /// `ty::query::plumbing` when executing a query.
+    pub query: Option<query::QueryJobId>,
+
+    /// Where to store diagnostics for the current query job, if any.
+    /// This is updated by `JobOwner::start` in `ty::query::plumbing` when executing a query.
+    pub diagnostics: Option<&'a Lock<ThinVec<Diagnostic>>>,
+
+    /// Used to prevent queries from calling too deeply.
+    pub query_depth: usize,
+
+    /// The current dep graph task. This is used to add dependencies to queries
+    /// when executing them.
+    pub task_deps: TaskDepsRef<'a>,
+}
+
+impl<'a, 'tcx> ImplicitCtxt<'a, 'tcx> {
+    pub fn new(gcx: &'tcx GlobalCtxt<'tcx>) -> Self {
+        let tcx = TyCtxt { gcx };
+        ImplicitCtxt {
+            tcx,
+            query: None,
+            diagnostics: None,
+            query_depth: 0,
+            task_deps: TaskDepsRef::Ignore,
+        }
+    }
+}
+
+#[cfg(parallel_compiler)]
+mod tlv {
+    use rustc_rayon_core as rayon_core;
+    use std::ptr;
+
+    /// Gets Rayon's thread-local variable, which is preserved for Rayon jobs.
+    /// This is used to get the pointer to the current `ImplicitCtxt`.
+    #[inline]
+    pub(super) fn get_tlv() -> *const () {
+        ptr::from_exposed_addr(rayon_core::tlv::get())
+    }
+
+    /// Sets Rayon's thread-local variable, which is preserved for Rayon jobs
+    /// to `value` during the call to `f`. It is restored to its previous value after.
+    /// This is used to set the pointer to the new `ImplicitCtxt`.
+    #[inline]
+    pub(super) fn with_tlv<F: FnOnce() -> R, R>(value: *const (), f: F) -> R {
+        rayon_core::tlv::with(value.expose_addr(), f)
+    }
+}
+
+#[cfg(not(parallel_compiler))]
+mod tlv {
+    use std::cell::Cell;
+    use std::ptr;
+
+    thread_local! {
+        /// A thread local variable that stores a pointer to the current `ImplicitCtxt`.
+        static TLV: Cell<*const ()> = const { Cell::new(ptr::null()) };
+    }
+
+    /// Gets the pointer to the current `ImplicitCtxt`.
+    #[inline]
+    pub(super) fn get_tlv() -> *const () {
+        TLV.with(|tlv| tlv.get())
+    }
+
+    /// Sets TLV to `value` during the call to `f`.
+    /// It is restored to its previous value after.
+    /// This is used to set the pointer to the new `ImplicitCtxt`.
+    #[inline]
+    pub(super) fn with_tlv<F: FnOnce() -> R, R>(value: *const (), f: F) -> R {
+        let old = get_tlv();
+        let _reset = rustc_data_structures::OnDrop(move || TLV.with(|tlv| tlv.set(old)));
+        TLV.with(|tlv| tlv.set(value));
+        f()
+    }
+}
+
+#[inline]
+fn erase(context: &ImplicitCtxt<'_, '_>) -> *const () {
+    context as *const _ as *const ()
+}
+
+#[inline]
+unsafe fn downcast<'a, 'tcx>(context: *const ()) -> &'a ImplicitCtxt<'a, 'tcx> {
+    &*(context as *const ImplicitCtxt<'a, 'tcx>)
+}
+
+/// Sets `context` as the new current `ImplicitCtxt` for the duration of the function `f`.
+#[inline]
+pub fn enter_context<'a, 'tcx, F, R>(context: &ImplicitCtxt<'a, 'tcx>, f: F) -> R
+where
+    F: FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
+{
+    tlv::with_tlv(erase(context), || f(&context))
+}
+
+/// Allows access to the current `ImplicitCtxt` in a closure if one is available.
+#[inline]
+pub fn with_context_opt<F, R>(f: F) -> R
+where
+    F: for<'a, 'tcx> FnOnce(Option<&ImplicitCtxt<'a, 'tcx>>) -> R,
+{
+    let context = tlv::get_tlv();
+    if context.is_null() {
+        f(None)
+    } else {
+        // We could get an `ImplicitCtxt` pointer from another thread.
+        // Ensure that `ImplicitCtxt` is `Sync`.
+        sync::assert_sync::<ImplicitCtxt<'_, '_>>();
+
+        unsafe { f(Some(downcast(context))) }
+    }
+}
+
+/// Allows access to the current `ImplicitCtxt`.
+/// Panics if there is no `ImplicitCtxt` available.
+#[inline]
+pub fn with_context<F, R>(f: F) -> R
+where
+    F: for<'a, 'tcx> FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
+{
+    with_context_opt(|opt_context| f(opt_context.expect("no ImplicitCtxt stored in tls")))
+}
+
+/// Allows access to the current `ImplicitCtxt` whose tcx field is the same as the tcx argument
+/// passed in. This means the closure is given an `ImplicitCtxt` with the same `'tcx` lifetime
+/// as the `TyCtxt` passed in.
+/// This will panic if you pass it a `TyCtxt` which is different from the current
+/// `ImplicitCtxt`'s `tcx` field.
+#[inline]
+pub fn with_related_context<'tcx, F, R>(tcx: TyCtxt<'tcx>, f: F) -> R
+where
+    F: FnOnce(&ImplicitCtxt<'_, 'tcx>) -> R,
+{
+    with_context(|context| {
+        // The two gcx have different invariant lifetimes, so we need to erase them for the comparison.
+        assert!(ptr::eq(
+            context.tcx.gcx as *const _ as *const (),
+            tcx.gcx as *const _ as *const ()
+        ));
+
+        let context: &ImplicitCtxt<'_, '_> = unsafe { mem::transmute(context) };
+
+        f(context)
+    })
+}
+
+/// Allows access to the `TyCtxt` in the current `ImplicitCtxt`.
+/// Panics if there is no `ImplicitCtxt` available.
+#[inline]
+pub fn with<F, R>(f: F) -> R
+where
+    F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> R,
+{
+    with_context(|context| f(context.tcx))
+}
+
+/// Allows access to the `TyCtxt` in the current `ImplicitCtxt`.
+/// The closure is passed None if there is no `ImplicitCtxt` available.
+#[inline]
+pub fn with_opt<F, R>(f: F) -> R
+where
+    F: for<'tcx> FnOnce(Option<TyCtxt<'tcx>>) -> R,
+{
+    with_context_opt(|opt_context| f(opt_context.map(|context| context.tcx)))
+}
diff --git a/compiler/rustc_middle/src/ty/error.rs b/compiler/rustc_middle/src/ty/error.rs
index 5d394f71f0d..d83fc95ac4e 100644
--- a/compiler/rustc_middle/src/ty/error.rs
+++ b/compiler/rustc_middle/src/ty/error.rs
@@ -1,24 +1,18 @@
-use crate::traits::{ObligationCause, ObligationCauseCode};
-use crate::ty::diagnostics::suggest_constraining_type_param;
-use crate::ty::print::{with_forced_trimmed_paths, FmtPrinter, Printer};
+use crate::ty::print::{with_forced_trimmed_paths, FmtPrinter, PrettyPrinter};
 use crate::ty::{self, BoundRegionKind, Region, Ty, TyCtxt};
-use rustc_errors::Applicability::{MachineApplicable, MaybeIncorrect};
-use rustc_errors::{pluralize, Diagnostic, MultiSpan};
+use rustc_errors::pluralize;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind};
 use rustc_hir::def_id::DefId;
-use rustc_span::symbol::{sym, Symbol};
-use rustc_span::{BytePos, Span};
+use rustc_span::symbol::Symbol;
 use rustc_target::spec::abi;
-
 use std::borrow::Cow;
 use std::collections::hash_map::DefaultHasher;
 use std::fmt;
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
+use std::hash::Hasher;
 use std::path::PathBuf;
 
-use super::print::PrettyPrinter;
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq, TypeFoldable, TypeVisitable, Lift)]
 pub struct ExpectedFound<T> {
     pub expected: T,
@@ -331,7 +325,8 @@ impl<'tcx> Ty<'tcx> {
             ty::Dynamic(..) => "trait object".into(),
             ty::Closure(..) => "closure".into(),
             ty::Generator(def_id, ..) => tcx.generator_kind(def_id).unwrap().descr().into(),
-            ty::GeneratorWitness(..) => "generator witness".into(),
+            ty::GeneratorWitness(..) |
+            ty::GeneratorWitnessMIR(..) => "generator witness".into(),
             ty::Tuple(..) => "tuple".into(),
             ty::Infer(ty::TyVar(_)) => "inferred type".into(),
             ty::Infer(ty::IntVar(_)) => "integer".into(),
@@ -379,7 +374,7 @@ impl<'tcx> Ty<'tcx> {
             ty::Dynamic(..) => "trait object".into(),
             ty::Closure(..) => "closure".into(),
             ty::Generator(def_id, ..) => tcx.generator_kind(def_id).unwrap().descr().into(),
-            ty::GeneratorWitness(..) => "generator witness".into(),
+            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => "generator witness".into(),
             ty::Tuple(..) => "tuple".into(),
             ty::Placeholder(..) => "higher-ranked type".into(),
             ty::Bound(..) => "bound type variable".into(),
@@ -391,620 +386,6 @@ impl<'tcx> Ty<'tcx> {
 }
 
 impl<'tcx> TyCtxt<'tcx> {
-    pub fn note_and_explain_type_err(
-        self,
-        diag: &mut Diagnostic,
-        err: TypeError<'tcx>,
-        cause: &ObligationCause<'tcx>,
-        sp: Span,
-        body_owner_def_id: DefId,
-    ) {
-        use self::TypeError::*;
-        debug!("note_and_explain_type_err err={:?} cause={:?}", err, cause);
-        match err {
-            ArgumentSorts(values, _) | Sorts(values) => {
-                match (values.expected.kind(), values.found.kind()) {
-                    (ty::Closure(..), ty::Closure(..)) => {
-                        diag.note("no two closures, even if identical, have the same type");
-                        diag.help("consider boxing your closure and/or using it as a trait object");
-                    }
-                    (ty::Alias(ty::Opaque, ..), ty::Alias(ty::Opaque, ..)) => {
-                        // Issue #63167
-                        diag.note("distinct uses of `impl Trait` result in different opaque types");
-                    }
-                    (ty::Float(_), ty::Infer(ty::IntVar(_)))
-                        if let Ok(
-                            // Issue #53280
-                            snippet,
-                        ) = self.sess.source_map().span_to_snippet(sp) =>
-                    {
-                        if snippet.chars().all(|c| c.is_digit(10) || c == '-' || c == '_') {
-                            diag.span_suggestion(
-                                sp,
-                                "use a float literal",
-                                format!("{}.0", snippet),
-                                MachineApplicable,
-                            );
-                        }
-                    }
-                    (ty::Param(expected), ty::Param(found)) => {
-                        let generics = self.generics_of(body_owner_def_id);
-                        let e_span = self.def_span(generics.type_param(expected, self).def_id);
-                        if !sp.contains(e_span) {
-                            diag.span_label(e_span, "expected type parameter");
-                        }
-                        let f_span = self.def_span(generics.type_param(found, self).def_id);
-                        if !sp.contains(f_span) {
-                            diag.span_label(f_span, "found type parameter");
-                        }
-                        diag.note(
-                            "a type parameter was expected, but a different one was found; \
-                             you might be missing a type parameter or trait bound",
-                        );
-                        diag.note(
-                            "for more information, visit \
-                             https://doc.rust-lang.org/book/ch10-02-traits.html\
-                             #traits-as-parameters",
-                        );
-                    }
-                    (ty::Alias(ty::Projection, _), ty::Alias(ty::Projection, _)) => {
-                        diag.note("an associated type was expected, but a different one was found");
-                    }
-                    (ty::Param(p), ty::Alias(ty::Projection, proj)) | (ty::Alias(ty::Projection, proj), ty::Param(p))
-                        if self.def_kind(proj.def_id) != DefKind::ImplTraitPlaceholder =>
-                    {
-                        let generics = self.generics_of(body_owner_def_id);
-                        let p_span = self.def_span(generics.type_param(p, self).def_id);
-                        if !sp.contains(p_span) {
-                            diag.span_label(p_span, "this type parameter");
-                        }
-                        let hir = self.hir();
-                        let mut note = true;
-                        if let Some(generics) = generics
-                            .type_param(p, self)
-                            .def_id
-                            .as_local()
-                            .map(|id| hir.local_def_id_to_hir_id(id))
-                            .and_then(|id| self.hir().find_parent(id))
-                            .as_ref()
-                            .and_then(|node| node.generics())
-                        {
-                            // Synthesize the associated type restriction `Add<Output = Expected>`.
-                            // FIXME: extract this logic for use in other diagnostics.
-                            let (trait_ref, assoc_substs) = proj.trait_ref_and_own_substs(self);
-                            let path =
-                                self.def_path_str_with_substs(trait_ref.def_id, trait_ref.substs);
-                            let item_name = self.item_name(proj.def_id);
-                            let item_args = self.format_generic_args(assoc_substs);
-
-                            let path = if path.ends_with('>') {
-                                format!(
-                                    "{}, {}{} = {}>",
-                                    &path[..path.len() - 1],
-                                    item_name,
-                                    item_args,
-                                    p
-                                )
-                            } else {
-                                format!("{}<{}{} = {}>", path, item_name, item_args, p)
-                            };
-                            note = !suggest_constraining_type_param(
-                                self,
-                                generics,
-                                diag,
-                                &format!("{}", proj.self_ty()),
-                                &path,
-                                None,
-                            );
-                        }
-                        if note {
-                            diag.note("you might be missing a type parameter or trait bound");
-                        }
-                    }
-                    (ty::Param(p), ty::Dynamic(..) | ty::Alias(ty::Opaque, ..))
-                    | (ty::Dynamic(..) | ty::Alias(ty::Opaque, ..), ty::Param(p)) => {
-                        let generics = self.generics_of(body_owner_def_id);
-                        let p_span = self.def_span(generics.type_param(p, self).def_id);
-                        if !sp.contains(p_span) {
-                            diag.span_label(p_span, "this type parameter");
-                        }
-                        diag.help("type parameters must be constrained to match other types");
-                        if self.sess.teach(&diag.get_code().unwrap()) {
-                            diag.help(
-                                "given a type parameter `T` and a method `foo`:
-```
-trait Trait<T> { fn foo(&self) -> T; }
-```
-the only ways to implement method `foo` are:
-- constrain `T` with an explicit type:
-```
-impl Trait<String> for X {
-    fn foo(&self) -> String { String::new() }
-}
-```
-- add a trait bound to `T` and call a method on that trait that returns `Self`:
-```
-impl<T: std::default::Default> Trait<T> for X {
-    fn foo(&self) -> T { <T as std::default::Default>::default() }
-}
-```
-- change `foo` to return an argument of type `T`:
-```
-impl<T> Trait<T> for X {
-    fn foo(&self, x: T) -> T { x }
-}
-```",
-                            );
-                        }
-                        diag.note(
-                            "for more information, visit \
-                             https://doc.rust-lang.org/book/ch10-02-traits.html\
-                             #traits-as-parameters",
-                        );
-                    }
-                    (ty::Param(p), ty::Closure(..) | ty::Generator(..)) => {
-                        let generics = self.generics_of(body_owner_def_id);
-                        let p_span = self.def_span(generics.type_param(p, self).def_id);
-                        if !sp.contains(p_span) {
-                            diag.span_label(p_span, "this type parameter");
-                        }
-                        diag.help(&format!(
-                            "every closure has a distinct type and so could not always match the \
-                             caller-chosen type of parameter `{}`",
-                            p
-                        ));
-                    }
-                    (ty::Param(p), _) | (_, ty::Param(p)) => {
-                        let generics = self.generics_of(body_owner_def_id);
-                        let p_span = self.def_span(generics.type_param(p, self).def_id);
-                        if !sp.contains(p_span) {
-                            diag.span_label(p_span, "this type parameter");
-                        }
-                    }
-                    (ty::Alias(ty::Projection, proj_ty), _) if self.def_kind(proj_ty.def_id) != DefKind::ImplTraitPlaceholder => {
-                        self.expected_projection(
-                            diag,
-                            proj_ty,
-                            values,
-                            body_owner_def_id,
-                            cause.code(),
-                        );
-                    }
-                    (_, ty::Alias(ty::Projection, proj_ty)) if self.def_kind(proj_ty.def_id) != DefKind::ImplTraitPlaceholder => {
-                        let msg = format!(
-                            "consider constraining the associated type `{}` to `{}`",
-                            values.found, values.expected,
-                        );
-                        if !(self.suggest_constraining_opaque_associated_type(
-                            diag,
-                            &msg,
-                            proj_ty,
-                            values.expected,
-                        ) || self.suggest_constraint(
-                            diag,
-                            &msg,
-                            body_owner_def_id,
-                            proj_ty,
-                            values.expected,
-                        )) {
-                            diag.help(&msg);
-                            diag.note(
-                                "for more information, visit \
-                                https://doc.rust-lang.org/book/ch19-03-advanced-traits.html",
-                            );
-                        }
-                    }
-                    _ => {}
-                }
-                debug!(
-                    "note_and_explain_type_err expected={:?} ({:?}) found={:?} ({:?})",
-                    values.expected,
-                    values.expected.kind(),
-                    values.found,
-                    values.found.kind(),
-                );
-            }
-            CyclicTy(ty) => {
-                // Watch out for various cases of cyclic types and try to explain.
-                if ty.is_closure() || ty.is_generator() {
-                    diag.note(
-                        "closures cannot capture themselves or take themselves as argument;\n\
-                         this error may be the result of a recent compiler bug-fix,\n\
-                         see issue #46062 <https://github.com/rust-lang/rust/issues/46062>\n\
-                         for more information",
-                    );
-                }
-            }
-            TargetFeatureCast(def_id) => {
-                let target_spans =
-                    self.get_attrs(def_id, sym::target_feature).map(|attr| attr.span);
-                diag.note(
-                    "functions with `#[target_feature]` can only be coerced to `unsafe` function pointers"
-                );
-                diag.span_labels(target_spans, "`#[target_feature]` added here");
-            }
-            _ => {}
-        }
-    }
-
-    fn suggest_constraint(
-        self,
-        diag: &mut Diagnostic,
-        msg: &str,
-        body_owner_def_id: DefId,
-        proj_ty: &ty::AliasTy<'tcx>,
-        ty: Ty<'tcx>,
-    ) -> bool {
-        let assoc = self.associated_item(proj_ty.def_id);
-        let (trait_ref, assoc_substs) = proj_ty.trait_ref_and_own_substs(self);
-        if let Some(item) = self.hir().get_if_local(body_owner_def_id) {
-            if let Some(hir_generics) = item.generics() {
-                // Get the `DefId` for the type parameter corresponding to `A` in `<A as T>::Foo`.
-                // This will also work for `impl Trait`.
-                let def_id = if let ty::Param(param_ty) = proj_ty.self_ty().kind() {
-                    let generics = self.generics_of(body_owner_def_id);
-                    generics.type_param(param_ty, self).def_id
-                } else {
-                    return false;
-                };
-                let Some(def_id) = def_id.as_local() else {
-                    return false;
-                };
-
-                // First look in the `where` clause, as this might be
-                // `fn foo<T>(x: T) where T: Trait`.
-                for pred in hir_generics.bounds_for_param(def_id) {
-                    if self.constrain_generic_bound_associated_type_structured_suggestion(
-                        diag,
-                        &trait_ref,
-                        pred.bounds,
-                        &assoc,
-                        assoc_substs,
-                        ty,
-                        msg,
-                        false,
-                    ) {
-                        return true;
-                    }
-                }
-            }
-        }
-        false
-    }
-
-    /// An associated type was expected and a different type was found.
-    ///
-    /// We perform a few different checks to see what we can suggest:
-    ///
-    ///  - In the current item, look for associated functions that return the expected type and
-    ///    suggest calling them. (Not a structured suggestion.)
-    ///  - If any of the item's generic bounds can be constrained, we suggest constraining the
-    ///    associated type to the found type.
-    ///  - If the associated type has a default type and was expected inside of a `trait`, we
-    ///    mention that this is disallowed.
-    ///  - If all other things fail, and the error is not because of a mismatch between the `trait`
-    ///    and the `impl`, we provide a generic `help` to constrain the assoc type or call an assoc
-    ///    fn that returns the type.
-    fn expected_projection(
-        self,
-        diag: &mut Diagnostic,
-        proj_ty: &ty::AliasTy<'tcx>,
-        values: ExpectedFound<Ty<'tcx>>,
-        body_owner_def_id: DefId,
-        cause_code: &ObligationCauseCode<'_>,
-    ) {
-        let msg = format!(
-            "consider constraining the associated type `{}` to `{}`",
-            values.expected, values.found
-        );
-        let body_owner = self.hir().get_if_local(body_owner_def_id);
-        let current_method_ident = body_owner.and_then(|n| n.ident()).map(|i| i.name);
-
-        // We don't want to suggest calling an assoc fn in a scope where that isn't feasible.
-        let callable_scope = matches!(
-            body_owner,
-            Some(
-                hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(..), .. })
-                    | hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
-                    | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }),
-            )
-        );
-        let impl_comparison =
-            matches!(cause_code, ObligationCauseCode::CompareImplItemObligation { .. });
-        let assoc = self.associated_item(proj_ty.def_id);
-        if !callable_scope || impl_comparison {
-            // We do not want to suggest calling functions when the reason of the
-            // type error is a comparison of an `impl` with its `trait` or when the
-            // scope is outside of a `Body`.
-        } else {
-            // If we find a suitable associated function that returns the expected type, we don't
-            // want the more general suggestion later in this method about "consider constraining
-            // the associated type or calling a method that returns the associated type".
-            let point_at_assoc_fn = self.point_at_methods_that_satisfy_associated_type(
-                diag,
-                assoc.container_id(self),
-                current_method_ident,
-                proj_ty.def_id,
-                values.expected,
-            );
-            // Possibly suggest constraining the associated type to conform to the
-            // found type.
-            if self.suggest_constraint(diag, &msg, body_owner_def_id, proj_ty, values.found)
-                || point_at_assoc_fn
-            {
-                return;
-            }
-        }
-
-        self.suggest_constraining_opaque_associated_type(diag, &msg, proj_ty, values.found);
-
-        if self.point_at_associated_type(diag, body_owner_def_id, values.found) {
-            return;
-        }
-
-        if !impl_comparison {
-            // Generic suggestion when we can't be more specific.
-            if callable_scope {
-                diag.help(&format!(
-                    "{} or calling a method that returns `{}`",
-                    msg, values.expected
-                ));
-            } else {
-                diag.help(&msg);
-            }
-            diag.note(
-                "for more information, visit \
-                 https://doc.rust-lang.org/book/ch19-03-advanced-traits.html",
-            );
-        }
-        if self.sess.teach(&diag.get_code().unwrap()) {
-            diag.help(
-                "given an associated type `T` and a method `foo`:
-```
-trait Trait {
-type T;
-fn foo(&self) -> Self::T;
-}
-```
-the only way of implementing method `foo` is to constrain `T` with an explicit associated type:
-```
-impl Trait for X {
-type T = String;
-fn foo(&self) -> Self::T { String::new() }
-}
-```",
-            );
-        }
-    }
-
-    /// When the expected `impl Trait` is not defined in the current item, it will come from
-    /// a return type. This can occur when dealing with `TryStream` (#71035).
-    fn suggest_constraining_opaque_associated_type(
-        self,
-        diag: &mut Diagnostic,
-        msg: &str,
-        proj_ty: &ty::AliasTy<'tcx>,
-        ty: Ty<'tcx>,
-    ) -> bool {
-        let assoc = self.associated_item(proj_ty.def_id);
-        if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *proj_ty.self_ty().kind() {
-            let opaque_local_def_id = def_id.as_local();
-            let opaque_hir_ty = if let Some(opaque_local_def_id) = opaque_local_def_id {
-                match &self.hir().expect_item(opaque_local_def_id).kind {
-                    hir::ItemKind::OpaqueTy(opaque_hir_ty) => opaque_hir_ty,
-                    _ => bug!("The HirId comes from a `ty::Opaque`"),
-                }
-            } else {
-                return false;
-            };
-
-            let (trait_ref, assoc_substs) = proj_ty.trait_ref_and_own_substs(self);
-
-            self.constrain_generic_bound_associated_type_structured_suggestion(
-                diag,
-                &trait_ref,
-                opaque_hir_ty.bounds,
-                assoc,
-                assoc_substs,
-                ty,
-                msg,
-                true,
-            )
-        } else {
-            false
-        }
-    }
-
-    fn point_at_methods_that_satisfy_associated_type(
-        self,
-        diag: &mut Diagnostic,
-        assoc_container_id: DefId,
-        current_method_ident: Option<Symbol>,
-        proj_ty_item_def_id: DefId,
-        expected: Ty<'tcx>,
-    ) -> bool {
-        let items = self.associated_items(assoc_container_id);
-        // Find all the methods in the trait that could be called to construct the
-        // expected associated type.
-        // FIXME: consider suggesting the use of associated `const`s.
-        let methods: Vec<(Span, String)> = items
-            .items
-            .iter()
-            .filter(|(name, item)| {
-                ty::AssocKind::Fn == item.kind && Some(**name) != current_method_ident
-            })
-            .filter_map(|(_, item)| {
-                let method = self.fn_sig(item.def_id);
-                match *method.output().skip_binder().kind() {
-                    ty::Alias(ty::Projection, ty::AliasTy { def_id: item_def_id, .. })
-                        if item_def_id == proj_ty_item_def_id =>
-                    {
-                        Some((
-                            self.def_span(item.def_id),
-                            format!("consider calling `{}`", self.def_path_str(item.def_id)),
-                        ))
-                    }
-                    _ => None,
-                }
-            })
-            .collect();
-        if !methods.is_empty() {
-            // Use a single `help:` to show all the methods in the trait that can
-            // be used to construct the expected associated type.
-            let mut span: MultiSpan =
-                methods.iter().map(|(sp, _)| *sp).collect::<Vec<Span>>().into();
-            let msg = format!(
-                "{some} method{s} {are} available that return{r} `{ty}`",
-                some = if methods.len() == 1 { "a" } else { "some" },
-                s = pluralize!(methods.len()),
-                are = pluralize!("is", methods.len()),
-                r = if methods.len() == 1 { "s" } else { "" },
-                ty = expected
-            );
-            for (sp, label) in methods.into_iter() {
-                span.push_span_label(sp, label);
-            }
-            diag.span_help(span, &msg);
-            return true;
-        }
-        false
-    }
-
-    fn point_at_associated_type(
-        self,
-        diag: &mut Diagnostic,
-        body_owner_def_id: DefId,
-        found: Ty<'tcx>,
-    ) -> bool {
-        let Some(hir_id) = body_owner_def_id.as_local() else {
-            return false;
-        };
-        let hir_id = self.hir().local_def_id_to_hir_id(hir_id);
-        // When `body_owner` is an `impl` or `trait` item, look in its associated types for
-        // `expected` and point at it.
-        let parent_id = self.hir().get_parent_item(hir_id);
-        let item = self.hir().find_by_def_id(parent_id.def_id);
-        debug!("expected_projection parent item {:?}", item);
-        match item {
-            Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Trait(.., items), .. })) => {
-                // FIXME: account for `#![feature(specialization)]`
-                for item in &items[..] {
-                    match item.kind {
-                        hir::AssocItemKind::Type => {
-                            // FIXME: account for returning some type in a trait fn impl that has
-                            // an assoc type as a return type (#72076).
-                            if let hir::Defaultness::Default { has_value: true } =
-                                self.impl_defaultness(item.id.owner_id)
-                            {
-                                if self.type_of(item.id.owner_id) == found {
-                                    diag.span_label(
-                                        item.span,
-                                        "associated type defaults can't be assumed inside the \
-                                            trait defining them",
-                                    );
-                                    return true;
-                                }
-                            }
-                        }
-                        _ => {}
-                    }
-                }
-            }
-            Some(hir::Node::Item(hir::Item {
-                kind: hir::ItemKind::Impl(hir::Impl { items, .. }),
-                ..
-            })) => {
-                for item in &items[..] {
-                    if let hir::AssocItemKind::Type = item.kind {
-                        if self.type_of(item.id.owner_id) == found {
-                            diag.span_label(item.span, "expected this associated type");
-                            return true;
-                        }
-                    }
-                }
-            }
-            _ => {}
-        }
-        false
-    }
-
-    /// Given a slice of `hir::GenericBound`s, if any of them corresponds to the `trait_ref`
-    /// requirement, provide a structured suggestion to constrain it to a given type `ty`.
-    ///
-    /// `is_bound_surely_present` indicates whether we know the bound we're looking for is
-    /// inside `bounds`. If that's the case then we can consider `bounds` containing only one
-    /// trait bound as the one we're looking for. This can help in cases where the associated
-    /// type is defined on a supertrait of the one present in the bounds.
-    fn constrain_generic_bound_associated_type_structured_suggestion(
-        self,
-        diag: &mut Diagnostic,
-        trait_ref: &ty::TraitRef<'tcx>,
-        bounds: hir::GenericBounds<'_>,
-        assoc: &ty::AssocItem,
-        assoc_substs: &[ty::GenericArg<'tcx>],
-        ty: Ty<'tcx>,
-        msg: &str,
-        is_bound_surely_present: bool,
-    ) -> bool {
-        // FIXME: we would want to call `resolve_vars_if_possible` on `ty` before suggesting.
-
-        let trait_bounds = bounds.iter().filter_map(|bound| match bound {
-            hir::GenericBound::Trait(ptr, hir::TraitBoundModifier::None) => Some(ptr),
-            _ => None,
-        });
-
-        let matching_trait_bounds = trait_bounds
-            .clone()
-            .filter(|ptr| ptr.trait_ref.trait_def_id() == Some(trait_ref.def_id))
-            .collect::<Vec<_>>();
-
-        let span = match &matching_trait_bounds[..] {
-            &[ptr] => ptr.span,
-            &[] if is_bound_surely_present => match &trait_bounds.collect::<Vec<_>>()[..] {
-                &[ptr] => ptr.span,
-                _ => return false,
-            },
-            _ => return false,
-        };
-
-        self.constrain_associated_type_structured_suggestion(
-            diag,
-            span,
-            assoc,
-            assoc_substs,
-            ty,
-            msg,
-        )
-    }
-
-    /// Given a span corresponding to a bound, provide a structured suggestion to set an
-    /// associated type to a given type `ty`.
-    fn constrain_associated_type_structured_suggestion(
-        self,
-        diag: &mut Diagnostic,
-        span: Span,
-        assoc: &ty::AssocItem,
-        assoc_substs: &[ty::GenericArg<'tcx>],
-        ty: Ty<'tcx>,
-        msg: &str,
-    ) -> bool {
-        if let Ok(has_params) =
-            self.sess.source_map().span_to_snippet(span).map(|snippet| snippet.ends_with('>'))
-        {
-            let (span, sugg) = if has_params {
-                let pos = span.hi() - BytePos(1);
-                let span = Span::new(pos, pos, span.ctxt(), span.parent());
-                (span, format!(", {} = {}", assoc.ident(self), ty))
-            } else {
-                let item_args = self.format_generic_args(assoc_substs);
-                (span.shrink_to_hi(), format!("<{}{} = {}>", assoc.ident(self), item_args, ty))
-            };
-            diag.span_suggestion_verbose(span, msg, sugg, MaybeIncorrect);
-            return true;
-        }
-        false
-    }
-
     pub fn short_ty_string(self, ty: Ty<'tcx>) -> (String, Option<PathBuf>) {
         let width = self.sess.diagnostic_width();
         let length_limit = width.saturating_sub(30);
@@ -1047,11 +428,4 @@ fn foo(&self) -> Self::T { String::new() }
             Err(_) => (regular, None),
         }
     }
-
-    fn format_generic_args(self, args: &[ty::GenericArg<'tcx>]) -> String {
-        FmtPrinter::new(self, hir::def::Namespace::TypeNS)
-            .path_generic_args(Ok, args)
-            .expect("could not write to `String`.")
-            .into_buffer()
-    }
 }
diff --git a/compiler/rustc_middle/src/ty/fast_reject.rs b/compiler/rustc_middle/src/ty/fast_reject.rs
index f785fb5c4b9..9afa37e9ef3 100644
--- a/compiler/rustc_middle/src/ty/fast_reject.rs
+++ b/compiler/rustc_middle/src/ty/fast_reject.rs
@@ -32,6 +32,7 @@ pub enum SimplifiedType {
     ClosureSimplifiedType(DefId),
     GeneratorSimplifiedType(DefId),
     GeneratorWitnessSimplifiedType(usize),
+    GeneratorWitnessMIRSimplifiedType(DefId),
     FunctionSimplifiedType(usize),
     PlaceholderSimplifiedType,
 }
@@ -108,6 +109,7 @@ pub fn simplify_type<'tcx>(
         ty::FnDef(def_id, _) | ty::Closure(def_id, _) => Some(ClosureSimplifiedType(def_id)),
         ty::Generator(def_id, _, _) => Some(GeneratorSimplifiedType(def_id)),
         ty::GeneratorWitness(tys) => Some(GeneratorWitnessSimplifiedType(tys.skip_binder().len())),
+        ty::GeneratorWitnessMIR(def_id, _) => Some(GeneratorWitnessMIRSimplifiedType(def_id)),
         ty::Never => Some(NeverSimplifiedType),
         ty::Tuple(tys) => Some(TupleSimplifiedType(tys.len())),
         ty::FnPtr(f) => Some(FunctionSimplifiedType(f.skip_binder().inputs().len())),
@@ -139,7 +141,8 @@ impl SimplifiedType {
             | ForeignSimplifiedType(d)
             | TraitSimplifiedType(d)
             | ClosureSimplifiedType(d)
-            | GeneratorSimplifiedType(d) => Some(d),
+            | GeneratorSimplifiedType(d)
+            | GeneratorWitnessMIRSimplifiedType(d) => Some(d),
             _ => None,
         }
     }
@@ -208,6 +211,7 @@ impl DeepRejectCtxt {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Placeholder(..)
             | ty::Bound(..)
             | ty::Infer(_) => bug!("unexpected impl_ty: {impl_ty}"),
@@ -306,7 +310,7 @@ impl DeepRejectCtxt {
 
             ty::Error(_) => true,
 
-            ty::GeneratorWitness(..) | ty::Bound(..) => {
+            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) | ty::Bound(..) => {
                 bug!("unexpected obligation type: {:?}", obligation_ty)
             }
         }
diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs
index b7eafc4b437..dc6f5851b7d 100644
--- a/compiler/rustc_middle/src/ty/flags.rs
+++ b/compiler/rustc_middle/src/ty/flags.rs
@@ -125,6 +125,16 @@ impl FlagComputation {
                 self.bound_computation(ts, |flags, ts| flags.add_tys(ts));
             }
 
+            &ty::GeneratorWitnessMIR(_, ref substs) => {
+                let should_remove_further_specializable =
+                    !self.flags.contains(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+                self.add_substs(substs);
+                if should_remove_further_specializable {
+                    self.flags -= TypeFlags::STILL_FURTHER_SPECIALIZABLE;
+                }
+                self.add_flags(TypeFlags::HAS_TY_GENERATOR);
+            }
+
             &ty::Closure(_, substs) => {
                 let substs = substs.as_closure();
                 let should_remove_further_specializable =
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index 6ac00d16c53..8b4fccc58bd 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -459,7 +459,7 @@ impl<'tcx> Instance<'tcx> {
         substs: SubstsRef<'tcx>,
     ) -> Option<Instance<'tcx>> {
         debug!("resolve_for_vtable(def_id={:?}, substs={:?})", def_id, substs);
-        let fn_sig = tcx.fn_sig(def_id);
+        let fn_sig = tcx.fn_sig(def_id).subst_identity();
         let is_vtable_shim = !fn_sig.inputs().skip_binder().is_empty()
             && fn_sig.input(0).skip_binder().is_param(0)
             && tcx.generics_of(def_id).has_self;
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index dfd016569c2..cdcd6281f20 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -128,7 +128,8 @@ impl PrimitiveExt for Primitive {
             Int(i, signed) => i.to_ty(tcx, signed),
             F32 => tcx.types.f32,
             F64 => tcx.types.f64,
-            Pointer => tcx.mk_mut_ptr(tcx.mk_unit()),
+            // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+            Pointer(_) => tcx.mk_mut_ptr(tcx.mk_unit()),
         }
     }
 
@@ -138,7 +139,11 @@ impl PrimitiveExt for Primitive {
     fn to_int_ty<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
         match *self {
             Int(i, signed) => i.to_ty(tcx, signed),
-            Pointer => tcx.types.usize,
+            // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+            Pointer(_) => {
+                let signed = false;
+                tcx.data_layout().ptr_sized_integer().to_ty(tcx, signed)
+            }
             F32 | F64 => bug!("floats do not have an int type"),
         }
     }
@@ -640,6 +645,7 @@ where
                 | ty::Never
                 | ty::FnDef(..)
                 | ty::GeneratorWitness(..)
+                | ty::GeneratorWitnessMIR(..)
                 | ty::Foreign(..)
                 | ty::Dynamic(_, _, ty::Dyn) => {
                     bug!("TyAndLayout::field({:?}): not applicable", this)
@@ -812,132 +818,125 @@ where
         let tcx = cx.tcx();
         let param_env = cx.param_env();
 
-        let addr_space_of_ty = |ty: Ty<'tcx>| {
-            if ty.is_fn() { cx.data_layout().instruction_address_space } else { AddressSpace::DATA }
-        };
-
-        let pointee_info = match *this.ty.kind() {
-            ty::RawPtr(mt) if offset.bytes() == 0 => {
-                tcx.layout_of(param_env.and(mt.ty)).ok().map(|layout| PointeeInfo {
-                    size: layout.size,
-                    align: layout.align.abi,
-                    safe: None,
-                    address_space: addr_space_of_ty(mt.ty),
-                })
-            }
-            ty::FnPtr(fn_sig) if offset.bytes() == 0 => {
-                tcx.layout_of(param_env.and(tcx.mk_fn_ptr(fn_sig))).ok().map(|layout| PointeeInfo {
-                    size: layout.size,
-                    align: layout.align.abi,
-                    safe: None,
-                    address_space: cx.data_layout().instruction_address_space,
-                })
-            }
-            ty::Ref(_, ty, mt) if offset.bytes() == 0 => {
-                let address_space = addr_space_of_ty(ty);
-                let kind = if tcx.sess.opts.optimize == OptLevel::No {
-                    // Use conservative pointer kind if not optimizing. This saves us the
-                    // Freeze/Unpin queries, and can save time in the codegen backend (noalias
-                    // attributes in LLVM have compile-time cost even in unoptimized builds).
-                    PointerKind::SharedMutable
-                } else {
-                    match mt {
-                        hir::Mutability::Not => {
-                            if ty.is_freeze(tcx, cx.param_env()) {
-                                PointerKind::Frozen
-                            } else {
-                                PointerKind::SharedMutable
+        let pointee_info =
+            match *this.ty.kind() {
+                ty::RawPtr(mt) if offset.bytes() == 0 => {
+                    tcx.layout_of(param_env.and(mt.ty)).ok().map(|layout| PointeeInfo {
+                        size: layout.size,
+                        align: layout.align.abi,
+                        safe: None,
+                    })
+                }
+                ty::FnPtr(fn_sig) if offset.bytes() == 0 => {
+                    tcx.layout_of(param_env.and(tcx.mk_fn_ptr(fn_sig))).ok().map(|layout| {
+                        PointeeInfo { size: layout.size, align: layout.align.abi, safe: None }
+                    })
+                }
+                ty::Ref(_, ty, mt) if offset.bytes() == 0 => {
+                    let kind = if tcx.sess.opts.optimize == OptLevel::No {
+                        // Use conservative pointer kind if not optimizing. This saves us the
+                        // Freeze/Unpin queries, and can save time in the codegen backend (noalias
+                        // attributes in LLVM have compile-time cost even in unoptimized builds).
+                        PointerKind::SharedMutable
+                    } else {
+                        match mt {
+                            hir::Mutability::Not => {
+                                if ty.is_freeze(tcx, cx.param_env()) {
+                                    PointerKind::Frozen
+                                } else {
+                                    PointerKind::SharedMutable
+                                }
                             }
-                        }
-                        hir::Mutability::Mut => {
-                            // References to self-referential structures should not be considered
-                            // noalias, as another pointer to the structure can be obtained, that
-                            // is not based-on the original reference. We consider all !Unpin
-                            // types to be potentially self-referential here.
-                            if ty.is_unpin(tcx, cx.param_env()) {
-                                PointerKind::UniqueBorrowed
-                            } else {
-                                PointerKind::UniqueBorrowedPinned
+                            hir::Mutability::Mut => {
+                                // References to self-referential structures should not be considered
+                                // noalias, as another pointer to the structure can be obtained, that
+                                // is not based-on the original reference. We consider all !Unpin
+                                // types to be potentially self-referential here.
+                                if ty.is_unpin(tcx, cx.param_env()) {
+                                    PointerKind::UniqueBorrowed
+                                } else {
+                                    PointerKind::UniqueBorrowedPinned
+                                }
                             }
                         }
-                    }
-                };
+                    };
 
-                tcx.layout_of(param_env.and(ty)).ok().map(|layout| PointeeInfo {
-                    size: layout.size,
-                    align: layout.align.abi,
-                    safe: Some(kind),
-                    address_space,
-                })
-            }
+                    tcx.layout_of(param_env.and(ty)).ok().map(|layout| PointeeInfo {
+                        size: layout.size,
+                        align: layout.align.abi,
+                        safe: Some(kind),
+                    })
+                }
 
-            _ => {
-                let mut data_variant = match this.variants {
-                    // Within the discriminant field, only the niche itself is
-                    // always initialized, so we only check for a pointer at its
-                    // offset.
-                    //
-                    // If the niche is a pointer, it's either valid (according
-                    // to its type), or null (which the niche field's scalar
-                    // validity range encodes). This allows using
-                    // `dereferenceable_or_null` for e.g., `Option<&T>`, and
-                    // this will continue to work as long as we don't start
-                    // using more niches than just null (e.g., the first page of
-                    // the address space, or unaligned pointers).
-                    Variants::Multiple {
-                        tag_encoding: TagEncoding::Niche { untagged_variant, .. },
-                        tag_field,
-                        ..
-                    } if this.fields.offset(tag_field) == offset => {
-                        Some(this.for_variant(cx, untagged_variant))
-                    }
-                    _ => Some(this),
-                };
+                _ => {
+                    let mut data_variant = match this.variants {
+                        // Within the discriminant field, only the niche itself is
+                        // always initialized, so we only check for a pointer at its
+                        // offset.
+                        //
+                        // If the niche is a pointer, it's either valid (according
+                        // to its type), or null (which the niche field's scalar
+                        // validity range encodes). This allows using
+                        // `dereferenceable_or_null` for e.g., `Option<&T>`, and
+                        // this will continue to work as long as we don't start
+                        // using more niches than just null (e.g., the first page of
+                        // the address space, or unaligned pointers).
+                        Variants::Multiple {
+                            tag_encoding: TagEncoding::Niche { untagged_variant, .. },
+                            tag_field,
+                            ..
+                        } if this.fields.offset(tag_field) == offset => {
+                            Some(this.for_variant(cx, untagged_variant))
+                        }
+                        _ => Some(this),
+                    };
 
-                if let Some(variant) = data_variant {
-                    // We're not interested in any unions.
-                    if let FieldsShape::Union(_) = variant.fields {
-                        data_variant = None;
+                    if let Some(variant) = data_variant {
+                        // We're not interested in any unions.
+                        if let FieldsShape::Union(_) = variant.fields {
+                            data_variant = None;
+                        }
                     }
-                }
 
-                let mut result = None;
-
-                if let Some(variant) = data_variant {
-                    let ptr_end = offset + Pointer.size(cx);
-                    for i in 0..variant.fields.count() {
-                        let field_start = variant.fields.offset(i);
-                        if field_start <= offset {
-                            let field = variant.field(cx, i);
-                            result = field.to_result().ok().and_then(|field| {
-                                if ptr_end <= field_start + field.size {
-                                    // We found the right field, look inside it.
-                                    let field_info =
-                                        field.pointee_info_at(cx, offset - field_start);
-                                    field_info
-                                } else {
-                                    None
+                    let mut result = None;
+
+                    if let Some(variant) = data_variant {
+                        // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
+                        // (requires passing in the expected address space from the caller)
+                        let ptr_end = offset + Pointer(AddressSpace::DATA).size(cx);
+                        for i in 0..variant.fields.count() {
+                            let field_start = variant.fields.offset(i);
+                            if field_start <= offset {
+                                let field = variant.field(cx, i);
+                                result = field.to_result().ok().and_then(|field| {
+                                    if ptr_end <= field_start + field.size {
+                                        // We found the right field, look inside it.
+                                        let field_info =
+                                            field.pointee_info_at(cx, offset - field_start);
+                                        field_info
+                                    } else {
+                                        None
+                                    }
+                                });
+                                if result.is_some() {
+                                    break;
                                 }
-                            });
-                            if result.is_some() {
-                                break;
                             }
                         }
                     }
-                }
 
-                // FIXME(eddyb) This should be for `ptr::Unique<T>`, not `Box<T>`.
-                if let Some(ref mut pointee) = result {
-                    if let ty::Adt(def, _) = this.ty.kind() {
-                        if def.is_box() && offset.bytes() == 0 {
-                            pointee.safe = Some(PointerKind::UniqueOwned);
+                    // FIXME(eddyb) This should be for `ptr::Unique<T>`, not `Box<T>`.
+                    if let Some(ref mut pointee) = result {
+                        if let ty::Adt(def, _) = this.ty.kind() {
+                            if def.is_box() && offset.bytes() == 0 {
+                                pointee.safe = Some(PointerKind::UniqueOwned);
+                            }
                         }
                     }
-                }
 
-                result
-            }
-        };
+                    result
+                }
+            };
 
         debug!(
             "pointee_info_at (offset={:?}, type kind: {:?}) => {:?}",
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index f83bceca3b5..25c6777a14c 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -31,7 +31,6 @@ pub use generics::*;
 use rustc_ast as ast;
 use rustc_ast::node_id::NodeMap;
 use rustc_attr as attr;
-use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::intern::Interned;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -453,18 +452,6 @@ pub struct CReaderCacheKey {
 #[rustc_pass_by_value]
 pub struct Ty<'tcx>(Interned<'tcx, WithCachedTypeInfo<TyKind<'tcx>>>);
 
-impl<'tcx> TyCtxt<'tcx> {
-    /// A "bool" type used in rustc_mir_transform unit tests when we
-    /// have not spun up a TyCtxt.
-    pub const BOOL_TY_FOR_UNIT_TESTING: Ty<'tcx> =
-        Ty(Interned::new_unchecked(&WithCachedTypeInfo {
-            internee: ty::Bool,
-            stable_hash: Fingerprint::ZERO,
-            flags: TypeFlags::empty(),
-            outer_exclusive_binder: DebruijnIndex::from_usize(0),
-        }));
-}
-
 impl ty::EarlyBoundRegion {
     /// Does this early bound region have a name? Early bound regions normally
     /// always have names except when using anonymous lifetimes (`'_`).
@@ -2437,6 +2424,7 @@ impl<'tcx> TyCtxt<'tcx> {
         ident
     }
 
+    // FIXME(vincenzoapalzzo): move the HirId to a LocalDefId
     pub fn adjust_ident_and_get_scope(
         self,
         mut ident: Ident,
@@ -2470,10 +2458,6 @@ impl<'tcx> TyCtxt<'tcx> {
             }
     }
 
-    pub fn is_object_safe(self, key: DefId) -> bool {
-        self.object_safety_violations(key).is_empty()
-    }
-
     #[inline]
     pub fn is_const_fn_raw(self, def_id: DefId) -> bool {
         matches!(
diff --git a/compiler/rustc_middle/src/ty/opaque_types.rs b/compiler/rustc_middle/src/ty/opaque_types.rs
index 98cd92007c2..7ff58f02623 100644
--- a/compiler/rustc_middle/src/ty/opaque_types.rs
+++ b/compiler/rustc_middle/src/ty/opaque_types.rs
@@ -3,6 +3,7 @@ use crate::ty::fold::{TypeFolder, TypeSuperFoldable};
 use crate::ty::subst::{GenericArg, GenericArgKind};
 use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_data_structures::fx::FxHashMap;
+use rustc_span::def_id::DefId;
 use rustc_span::Span;
 
 /// Converts generic params of a TypeFoldable from one
@@ -47,6 +48,47 @@ impl<'tcx> ReverseMapper<'tcx> {
         assert!(!self.do_not_error);
         kind.fold_with(self)
     }
+
+    fn fold_closure_substs(
+        &mut self,
+        def_id: DefId,
+        substs: ty::SubstsRef<'tcx>,
+    ) -> ty::SubstsRef<'tcx> {
+        // I am a horrible monster and I pray for death. When
+        // we encounter a closure here, it is always a closure
+        // from within the function that we are currently
+        // type-checking -- one that is now being encapsulated
+        // in an opaque type. Ideally, we would
+        // go through the types/lifetimes that it references
+        // and treat them just like we would any other type,
+        // which means we would error out if we find any
+        // reference to a type/region that is not in the
+        // "reverse map".
+        //
+        // **However,** in the case of closures, there is a
+        // somewhat subtle (read: hacky) consideration. The
+        // problem is that our closure types currently include
+        // all the lifetime parameters declared on the
+        // enclosing function, even if they are unused by the
+        // closure itself. We can't readily filter them out,
+        // so here we replace those values with `'empty`. This
+        // can't really make a difference to the rest of the
+        // compiler; those regions are ignored for the
+        // outlives relation, and hence don't affect trait
+        // selection or auto traits, and they are erased
+        // during codegen.
+
+        let generics = self.tcx.generics_of(def_id);
+        self.tcx.mk_substs(substs.iter().enumerate().map(|(index, kind)| {
+            if index < generics.parent_count {
+                // Accommodate missing regions in the parent kinds...
+                self.fold_kind_no_missing_regions_error(kind)
+            } else {
+                // ...but not elsewhere.
+                self.fold_kind_normally(kind)
+            }
+        }))
+    }
 }
 
 impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> {
@@ -104,59 +146,20 @@ impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> {
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
         match *ty.kind() {
             ty::Closure(def_id, substs) => {
-                // I am a horrible monster and I pray for death. When
-                // we encounter a closure here, it is always a closure
-                // from within the function that we are currently
-                // type-checking -- one that is now being encapsulated
-                // in an opaque type. Ideally, we would
-                // go through the types/lifetimes that it references
-                // and treat them just like we would any other type,
-                // which means we would error out if we find any
-                // reference to a type/region that is not in the
-                // "reverse map".
-                //
-                // **However,** in the case of closures, there is a
-                // somewhat subtle (read: hacky) consideration. The
-                // problem is that our closure types currently include
-                // all the lifetime parameters declared on the
-                // enclosing function, even if they are unused by the
-                // closure itself. We can't readily filter them out,
-                // so here we replace those values with `'empty`. This
-                // can't really make a difference to the rest of the
-                // compiler; those regions are ignored for the
-                // outlives relation, and hence don't affect trait
-                // selection or auto traits, and they are erased
-                // during codegen.
-
-                let generics = self.tcx.generics_of(def_id);
-                let substs = self.tcx.mk_substs(substs.iter().enumerate().map(|(index, kind)| {
-                    if index < generics.parent_count {
-                        // Accommodate missing regions in the parent kinds...
-                        self.fold_kind_no_missing_regions_error(kind)
-                    } else {
-                        // ...but not elsewhere.
-                        self.fold_kind_normally(kind)
-                    }
-                }));
-
+                let substs = self.fold_closure_substs(def_id, substs);
                 self.tcx.mk_closure(def_id, substs)
             }
 
             ty::Generator(def_id, substs, movability) => {
-                let generics = self.tcx.generics_of(def_id);
-                let substs = self.tcx.mk_substs(substs.iter().enumerate().map(|(index, kind)| {
-                    if index < generics.parent_count {
-                        // Accommodate missing regions in the parent kinds...
-                        self.fold_kind_no_missing_regions_error(kind)
-                    } else {
-                        // ...but not elsewhere.
-                        self.fold_kind_normally(kind)
-                    }
-                }));
-
+                let substs = self.fold_closure_substs(def_id, substs);
                 self.tcx.mk_generator(def_id, substs, movability)
             }
 
+            ty::GeneratorWitnessMIR(def_id, substs) => {
+                let substs = self.fold_closure_substs(def_id, substs);
+                self.tcx.mk_generator_witness_mir(def_id, substs)
+            }
+
             ty::Param(param) => {
                 // Look it up in the substitution list.
                 match self.map.get(&ty.into()).map(|k| k.unpack()) {
diff --git a/compiler/rustc_middle/src/ty/parameterized.rs b/compiler/rustc_middle/src/ty/parameterized.rs
index 24f3d1acff1..84edb5f2a42 100644
--- a/compiler/rustc_middle/src/ty/parameterized.rs
+++ b/compiler/rustc_middle/src/ty/parameterized.rs
@@ -117,6 +117,7 @@ macro_rules! parameterized_over_tcx {
 parameterized_over_tcx! {
     crate::middle::exported_symbols::ExportedSymbol,
     crate::mir::Body,
+    crate::mir::GeneratorLayout,
     ty::Ty,
     ty::FnSig,
     ty::GenericPredicates,
diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
index c302c461195..90bf3288ccf 100644
--- a/compiler/rustc_middle/src/ty/print/mod.rs
+++ b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -265,6 +265,7 @@ fn characteristic_def_id_of_type_cached<'a>(
         ty::FnDef(def_id, _)
         | ty::Closure(def_id, _)
         | ty::Generator(def_id, _, _)
+        | ty::GeneratorWitnessMIR(def_id, _)
         | ty::Foreign(def_id) => Some(def_id),
 
         ty::Bool
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index ae7c20fff0c..f2abec216b7 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -675,7 +675,7 @@ pub trait PrettyPrinter<'tcx>:
                 p!(")")
             }
             ty::FnDef(def_id, substs) => {
-                let sig = self.tcx().bound_fn_sig(def_id).subst(self.tcx(), substs);
+                let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
                 p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
             }
             ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),
@@ -811,6 +811,28 @@ pub trait PrettyPrinter<'tcx>:
             ty::GeneratorWitness(types) => {
                 p!(in_binder(&types));
             }
+            ty::GeneratorWitnessMIR(did, substs) => {
+                p!(write("["));
+                if !self.tcx().sess.verbose() {
+                    p!("generator witness");
+                    // FIXME(eddyb) should use `def_span`.
+                    if let Some(did) = did.as_local() {
+                        let span = self.tcx().def_span(did);
+                        p!(write(
+                            "@{}",
+                            // This may end up in stderr diagnostics but it may also be emitted
+                            // into MIR. Hence we use the remapped path if available
+                            self.tcx().sess.source_map().span_to_embeddable_string(span)
+                        ));
+                    } else {
+                        p!(write("@"), print_def_path(did, substs));
+                    }
+                } else {
+                    p!(print_def_path(did, substs));
+                }
+
+                p!("]")
+            }
             ty::Closure(did, substs) => {
                 p!(write("["));
                 if !self.should_print_verbose() {
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index 9d4ee22a727..1be819ca610 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -118,6 +118,7 @@ fn copy<T: Copy>(x: &T) -> T {
 
 macro_rules! query_helper_param_ty {
     (DefId) => { impl IntoQueryParam<DefId> };
+    (LocalDefId) => { impl IntoQueryParam<LocalDefId> };
     ($K:ty) => { $K };
 }
 
@@ -418,6 +419,13 @@ mod sealed {
         }
     }
 
+    impl IntoQueryParam<LocalDefId> for OwnerId {
+        #[inline(always)]
+        fn into_query_param(self) -> LocalDefId {
+            self.def_id
+        }
+    }
+
     impl IntoQueryParam<DefId> for LocalDefId {
         #[inline(always)]
         fn into_query_param(self) -> DefId {
@@ -441,6 +449,10 @@ impl<'tcx> TyCtxt<'tcx> {
         self.opt_def_kind(def_id)
             .unwrap_or_else(|| bug!("def_kind: unsupported node: {:?}", def_id))
     }
+
+    pub fn bound_type_of(self, def_id: impl IntoQueryParam<DefId>) -> ty::EarlyBinder<Ty<'tcx>> {
+        ty::EarlyBinder(self.type_of(def_id))
+    }
 }
 
 impl<'tcx> TyCtxtAt<'tcx> {
@@ -449,4 +461,8 @@ impl<'tcx> TyCtxtAt<'tcx> {
         self.opt_def_kind(def_id)
             .unwrap_or_else(|| bug!("def_kind: unsupported node: {:?}", def_id))
     }
+
+    pub fn bound_type_of(self, def_id: impl IntoQueryParam<DefId>) -> ty::EarlyBinder<Ty<'tcx>> {
+        ty::EarlyBinder(self.type_of(def_id))
+    }
 }
diff --git a/compiler/rustc_middle/src/ty/relate.rs b/compiler/rustc_middle/src/ty/relate.rs
index 65fd8d9753d..fa87301df7e 100644
--- a/compiler/rustc_middle/src/ty/relate.rs
+++ b/compiler/rustc_middle/src/ty/relate.rs
@@ -443,12 +443,7 @@ pub fn super_relate_tys<'tcx, R: TypeRelation<'tcx>>(
             if a_repr == b_repr =>
         {
             let region_bound = relation.with_cause(Cause::ExistentialRegionBound, |relation| {
-                relation.relate_with_variance(
-                    ty::Contravariant,
-                    ty::VarianceDiagInfo::default(),
-                    a_region,
-                    b_region,
-                )
+                relation.relate(a_region, b_region)
             })?;
             Ok(tcx.mk_dynamic(relation.relate(a_obj, b_obj)?, region_bound, a_repr))
         }
@@ -473,6 +468,16 @@ pub fn super_relate_tys<'tcx, R: TypeRelation<'tcx>>(
             Ok(tcx.mk_generator_witness(types))
         }
 
+        (&ty::GeneratorWitnessMIR(a_id, a_substs), &ty::GeneratorWitnessMIR(b_id, b_substs))
+            if a_id == b_id =>
+        {
+            // All GeneratorWitness types with the same id represent
+            // the (anonymous) type of the same generator expression. So
+            // all of their regions should be equated.
+            let substs = relation.relate(a_substs, b_substs)?;
+            Ok(tcx.mk_generator_witness_mir(a_id, substs))
+        }
+
         (&ty::Closure(a_id, a_substs), &ty::Closure(b_id, b_substs)) if a_id == b_id => {
             // All Closure types with the same id represent
             // the (anonymous) type of the same closure expression. So
@@ -487,12 +492,7 @@ pub fn super_relate_tys<'tcx, R: TypeRelation<'tcx>>(
         }
 
         (&ty::Ref(a_r, a_ty, a_mutbl), &ty::Ref(b_r, b_ty, b_mutbl)) => {
-            let r = relation.relate_with_variance(
-                ty::Contravariant,
-                ty::VarianceDiagInfo::default(),
-                a_r,
-                b_r,
-            )?;
+            let r = relation.relate(a_r, b_r)?;
             let a_mt = ty::TypeAndMut { ty: a_ty, mutbl: a_mutbl };
             let b_mt = ty::TypeAndMut { ty: b_ty, mutbl: b_mutbl };
             let mt = relate_type_and_mut(relation, a_mt, b_mt, a)?;
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 7d4d35b7fdf..034aab0c38e 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -11,6 +11,7 @@ use crate::ty::{self, AliasTy, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
 use rustc_data_structures::functor::IdFunctor;
 use rustc_hir::def::Namespace;
 use rustc_index::vec::{Idx, IndexVec};
+use rustc_target::abi::TyAndLayout;
 
 use std::fmt;
 use std::mem::ManuallyDrop;
@@ -200,6 +201,7 @@ TrivialTypeTraversalAndLiftImpls! {
     bool,
     usize,
     ::rustc_target::abi::VariantIdx,
+    u16,
     u32,
     u64,
     String,
@@ -654,6 +656,9 @@ impl<'tcx> TypeSuperFoldable<'tcx> for Ty<'tcx> {
                 ty::Generator(did, substs.try_fold_with(folder)?, movability)
             }
             ty::GeneratorWitness(types) => ty::GeneratorWitness(types.try_fold_with(folder)?),
+            ty::GeneratorWitnessMIR(did, substs) => {
+                ty::GeneratorWitnessMIR(did, substs.try_fold_with(folder)?)
+            }
             ty::Closure(did, substs) => ty::Closure(did, substs.try_fold_with(folder)?),
             ty::Alias(kind, data) => ty::Alias(kind, data.try_fold_with(folder)?),
 
@@ -699,6 +704,7 @@ impl<'tcx> TypeSuperVisitable<'tcx> for Ty<'tcx> {
             }
             ty::Generator(_did, ref substs, _) => substs.visit_with(visitor),
             ty::GeneratorWitness(ref types) => types.visit_with(visitor),
+            ty::GeneratorWitnessMIR(_did, ref substs) => substs.visit_with(visitor),
             ty::Closure(_did, ref substs) => substs.visit_with(visitor),
             ty::Alias(_, ref data) => data.visit_with(visitor),
 
@@ -853,3 +859,9 @@ impl<'tcx> TypeSuperVisitable<'tcx> for ty::UnevaluatedConst<'tcx> {
         self.substs.visit_with(visitor)
     }
 }
+
+impl<'tcx> TypeVisitable<'tcx> for TyAndLayout<'tcx, Ty<'tcx>> {
+    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+        visitor.visit_ty(self.ty)
+    }
+}
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 6a7b23e40a7..f97d2e753a3 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -571,9 +571,9 @@ impl<'tcx> GeneratorSubsts<'tcx> {
     ) -> impl Iterator<Item = impl Iterator<Item = Ty<'tcx>> + Captures<'tcx>> {
         let layout = tcx.generator_layout(def_id).unwrap();
         layout.variant_fields.iter().map(move |variant| {
-            variant
-                .iter()
-                .map(move |field| ty::EarlyBinder(layout.field_tys[*field]).subst(tcx, self.substs))
+            variant.iter().map(move |field| {
+                ty::EarlyBinder(layout.field_tys[*field].ty).subst(tcx, self.substs)
+            })
         })
     }
 
@@ -2059,7 +2059,7 @@ impl<'tcx> Ty<'tcx> {
 
     pub fn fn_sig(self, tcx: TyCtxt<'tcx>) -> PolyFnSig<'tcx> {
         match self.kind() {
-            FnDef(def_id, substs) => tcx.bound_fn_sig(*def_id).subst(tcx, substs),
+            FnDef(def_id, substs) => tcx.fn_sig(*def_id).subst(tcx, substs),
             FnPtr(f) => *f,
             Error(_) => {
                 // ignore errors (#54954)
@@ -2175,6 +2175,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Dynamic(..)
             | ty::Closure(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Error(_)
@@ -2210,6 +2211,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Ref(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Array(..)
             | ty::Closure(..)
             | ty::Never
@@ -2296,6 +2298,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Ref(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Array(..)
             | ty::Closure(..)
             | ty::Never
@@ -2360,7 +2363,7 @@ impl<'tcx> Ty<'tcx> {
             // anything with custom metadata it might be more complicated.
             ty::Ref(_, _, hir::Mutability::Not) | ty::RawPtr(..) => false,
 
-            ty::Generator(..) | ty::GeneratorWitness(..) => false,
+            ty::Generator(..) | ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => false,
 
             // Might be, but not "trivial" so just giving the safe answer.
             ty::Adt(..) | ty::Closure(..) => false,
diff --git a/compiler/rustc_middle/src/ty/subst.rs b/compiler/rustc_middle/src/ty/subst.rs
index a07582fc8ff..cf1bb5f8ac8 100644
--- a/compiler/rustc_middle/src/ty/subst.rs
+++ b/compiler/rustc_middle/src/ty/subst.rs
@@ -758,6 +758,11 @@ impl<'tcx, T: TypeFoldable<'tcx>> ty::EarlyBinder<T> {
     pub fn subst_identity(self) -> T {
         self.0
     }
+
+    /// Returns the inner value, but only if it contains no bound vars.
+    pub fn no_bound_vars(self) -> Option<T> {
+        if !self.0.needs_subst() { Some(self.0) } else { None }
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////
diff --git a/compiler/rustc_middle/src/ty/typeck_results.rs b/compiler/rustc_middle/src/ty/typeck_results.rs
index 2902c6dc556..79a6c730d71 100644
--- a/compiler/rustc_middle/src/ty/typeck_results.rs
+++ b/compiler/rustc_middle/src/ty/typeck_results.rs
@@ -1,6 +1,7 @@
 use crate::{
     hir::place::Place as HirPlace,
     infer::canonical::Canonical,
+    traits::ObligationCause,
     ty::{
         self, tls, BindingMode, BoundVar, CanonicalPolyFnSig, ClosureSizeProfileData,
         GenericArgKind, InternalSubsts, SubstsRef, Ty, UserSubsts,
@@ -193,6 +194,11 @@ pub struct TypeckResults<'tcx> {
     /// that are live across the yield of this generator (if a generator).
     pub generator_interior_types: ty::Binder<'tcx, Vec<GeneratorInteriorTypeCause<'tcx>>>,
 
+    /// Stores the predicates that apply on generator witness types.
+    /// formatting modified file tests/ui/generator/retain-resume-ref.rs
+    pub generator_interior_predicates:
+        FxHashMap<LocalDefId, Vec<(ty::Predicate<'tcx>, ObligationCause<'tcx>)>>,
+
     /// We sometimes treat byte string literals (which are of type `&[u8; N]`)
     /// as `&[u8]`, depending on the pattern in which they are used.
     /// This hashset records all instances where we behave
@@ -271,6 +277,7 @@ impl<'tcx> TypeckResults<'tcx> {
             closure_fake_reads: Default::default(),
             rvalue_scopes: Default::default(),
             generator_interior_types: ty::Binder::dummy(Default::default()),
+            generator_interior_predicates: Default::default(),
             treat_byte_string_as_slice: Default::default(),
             closure_size_eval: Default::default(),
         }
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 60076c8cb5f..796164b0d6a 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -3,7 +3,6 @@
 use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::mir;
 use crate::ty::layout::IntegerExt;
-use crate::ty::query::TyCtxtAt;
 use crate::ty::{
     self, DefIdTree, FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable,
     TypeVisitable,
@@ -616,6 +615,36 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    /// Return the set of types that should be taken into accound when checking
+    /// trait bounds on a generator's internal state.
+    pub fn generator_hidden_types(
+        self,
+        def_id: DefId,
+    ) -> impl Iterator<Item = ty::EarlyBinder<Ty<'tcx>>> {
+        let generator_layout = &self.mir_generator_witnesses(def_id);
+        generator_layout
+            .field_tys
+            .iter()
+            .filter(|decl| !decl.ignore_for_traits)
+            .map(|decl| ty::EarlyBinder(decl.ty))
+    }
+
+    /// Normalizes all opaque types in the given value, replacing them
+    /// with their underlying types.
+    pub fn expand_opaque_types(self, val: Ty<'tcx>) -> Ty<'tcx> {
+        let mut visitor = OpaqueTypeExpander {
+            seen_opaque_tys: FxHashSet::default(),
+            expanded_cache: FxHashMap::default(),
+            primary_def_id: None,
+            found_recursion: false,
+            found_any_recursion: false,
+            check_recursion: false,
+            expand_generators: false,
+            tcx: self,
+        };
+        val.fold_with(&mut visitor)
+    }
+
     /// Expands the given impl trait type, stopping if the type is recursive.
     #[instrument(skip(self), level = "debug", ret)]
     pub fn try_expand_impl_trait_type(
@@ -630,6 +659,7 @@ impl<'tcx> TyCtxt<'tcx> {
             found_recursion: false,
             found_any_recursion: false,
             check_recursion: true,
+            expand_generators: true,
             tcx: self,
         };
 
@@ -637,10 +667,6 @@ impl<'tcx> TyCtxt<'tcx> {
         if visitor.found_recursion { Err(expanded_type) } else { Ok(expanded_type) }
     }
 
-    pub fn bound_type_of(self, def_id: DefId) -> ty::EarlyBinder<Ty<'tcx>> {
-        ty::EarlyBinder(self.type_of(def_id))
-    }
-
     pub fn bound_return_position_impl_trait_in_trait_tys(
         self,
         def_id: DefId,
@@ -648,10 +674,6 @@ impl<'tcx> TyCtxt<'tcx> {
         ty::EarlyBinder(self.collect_return_position_impl_trait_in_trait_tys(def_id))
     }
 
-    pub fn bound_fn_sig(self, def_id: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'tcx>> {
-        ty::EarlyBinder(self.fn_sig(def_id))
-    }
-
     pub fn bound_explicit_item_bounds(
         self,
         def_id: DefId,
@@ -738,12 +760,6 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-impl<'tcx> TyCtxtAt<'tcx> {
-    pub fn bound_type_of(self, def_id: DefId) -> ty::EarlyBinder<Ty<'tcx>> {
-        ty::EarlyBinder(self.type_of(def_id))
-    }
-}
-
 struct OpaqueTypeExpander<'tcx> {
     // Contains the DefIds of the opaque types that are currently being
     // expanded. When we expand an opaque type we insert the DefId of
@@ -756,6 +772,7 @@ struct OpaqueTypeExpander<'tcx> {
     primary_def_id: Option<DefId>,
     found_recursion: bool,
     found_any_recursion: bool,
+    expand_generators: bool,
     /// Whether or not to check for recursive opaque types.
     /// This is `true` when we're explicitly checking for opaque type
     /// recursion, and 'false' otherwise to avoid unnecessary work.
@@ -792,6 +809,37 @@ impl<'tcx> OpaqueTypeExpander<'tcx> {
             None
         }
     }
+
+    fn expand_generator(&mut self, def_id: DefId, substs: SubstsRef<'tcx>) -> Option<Ty<'tcx>> {
+        if self.found_any_recursion {
+            return None;
+        }
+        let substs = substs.fold_with(self);
+        if !self.check_recursion || self.seen_opaque_tys.insert(def_id) {
+            let expanded_ty = match self.expanded_cache.get(&(def_id, substs)) {
+                Some(expanded_ty) => *expanded_ty,
+                None => {
+                    for bty in self.tcx.generator_hidden_types(def_id) {
+                        let hidden_ty = bty.subst(self.tcx, substs);
+                        self.fold_ty(hidden_ty);
+                    }
+                    let expanded_ty = self.tcx.mk_generator_witness_mir(def_id, substs);
+                    self.expanded_cache.insert((def_id, substs), expanded_ty);
+                    expanded_ty
+                }
+            };
+            if self.check_recursion {
+                self.seen_opaque_tys.remove(&def_id);
+            }
+            Some(expanded_ty)
+        } else {
+            // If another opaque type that we contain is recursive, then it
+            // will report the error, so we don't have to.
+            self.found_any_recursion = true;
+            self.found_recursion = def_id == *self.primary_def_id.as_ref().unwrap();
+            None
+        }
+    }
 }
 
 impl<'tcx> TypeFolder<'tcx> for OpaqueTypeExpander<'tcx> {
@@ -800,13 +848,19 @@ impl<'tcx> TypeFolder<'tcx> for OpaqueTypeExpander<'tcx> {
     }
 
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
-        if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) = *t.kind() {
+        let mut t = if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) = *t.kind() {
             self.expand_opaque_ty(def_id, substs).unwrap_or(t)
-        } else if t.has_opaque_types() {
+        } else if t.has_opaque_types() || t.has_generators() {
             t.super_fold_with(self)
         } else {
             t
+        };
+        if self.expand_generators {
+            if let ty::GeneratorWitnessMIR(def_id, substs) = *t.kind() {
+                t = self.expand_generator(def_id, substs).unwrap_or(t);
+            }
         }
+        t
     }
 }
 
@@ -911,6 +965,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Foreign(_)
             | ty::Generator(..)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Infer(_)
             | ty::Alias(..)
             | ty::Param(_)
@@ -950,6 +1005,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Foreign(_)
             | ty::Generator(..)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Infer(_)
             | ty::Alias(..)
             | ty::Param(_)
@@ -1077,7 +1133,10 @@ impl<'tcx> Ty<'tcx> {
                 false
             }
 
-            ty::Foreign(_) | ty::GeneratorWitness(..) | ty::Error(_) => false,
+            ty::Foreign(_)
+            | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
+            | ty::Error(_) => false,
         }
     }
 
@@ -1173,6 +1232,7 @@ pub fn needs_drop_components<'tcx>(
         | ty::FnPtr(_)
         | ty::Char
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::RawPtr(_)
         | ty::Ref(..)
         | ty::Str => Ok(SmallVec::new()),
@@ -1243,7 +1303,11 @@ pub fn is_trivially_const_drop(ty: Ty<'_>) -> bool {
 
         // Not trivial because they have components, and instead of looking inside,
         // we'll just perform trait selection.
-        ty::Closure(..) | ty::Generator(..) | ty::GeneratorWitness(_) | ty::Adt(..) => false,
+        ty::Closure(..)
+        | ty::Generator(..)
+        | ty::GeneratorWitness(_)
+        | ty::GeneratorWitnessMIR(..)
+        | ty::Adt(..) => false,
 
         ty::Array(ty, _) | ty::Slice(ty) => is_trivially_const_drop(ty),
 
@@ -1304,6 +1368,7 @@ pub fn reveal_opaque_types_in_bounds<'tcx>(
         found_recursion: false,
         found_any_recursion: false,
         check_recursion: false,
+        expand_generators: false,
         tcx,
     };
     val.fold_with(&mut visitor)
@@ -1326,7 +1391,7 @@ pub fn is_doc_notable_trait(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 
 /// Determines whether an item is an intrinsic by Abi.
 pub fn is_intrinsic(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-    matches!(tcx.fn_sig(def_id).abi(), Abi::RustIntrinsic | Abi::PlatformIntrinsic)
+    matches!(tcx.fn_sig(def_id).skip_binder().abi(), Abi::RustIntrinsic | Abi::PlatformIntrinsic)
 }
 
 pub fn provide(providers: &mut ty::query::Providers) {
diff --git a/compiler/rustc_middle/src/ty/visit.rs b/compiler/rustc_middle/src/ty/visit.rs
index bee3cc4d7cb..d7b7a094737 100644
--- a/compiler/rustc_middle/src/ty/visit.rs
+++ b/compiler/rustc_middle/src/ty/visit.rs
@@ -100,6 +100,9 @@ pub trait TypeVisitable<'tcx>: fmt::Debug + Clone {
     fn has_opaque_types(&self) -> bool {
         self.has_type_flags(TypeFlags::HAS_TY_OPAQUE)
     }
+    fn has_generators(&self) -> bool {
+        self.has_type_flags(TypeFlags::HAS_TY_GENERATOR)
+    }
     fn references_error(&self) -> bool {
         self.has_type_flags(TypeFlags::HAS_ERROR)
     }
diff --git a/compiler/rustc_middle/src/ty/walk.rs b/compiler/rustc_middle/src/ty/walk.rs
index 708a5e4d059..182945b9c3d 100644
--- a/compiler/rustc_middle/src/ty/walk.rs
+++ b/compiler/rustc_middle/src/ty/walk.rs
@@ -190,6 +190,7 @@ fn push_inner<'tcx>(stack: &mut TypeWalkerStack<'tcx>, parent: GenericArg<'tcx>)
             ty::Adt(_, substs)
             | ty::Closure(_, substs)
             | ty::Generator(_, substs, _)
+            | ty::GeneratorWitnessMIR(_, substs)
             | ty::FnDef(_, substs) => {
                 stack.extend(substs.iter().rev());
             }
diff --git a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
index 0bca02589bc..dbba529aef7 100644
--- a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
+++ b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
@@ -18,6 +18,9 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> {
             @call("mir_storage_dead", args) => {
                 Ok(StatementKind::StorageDead(self.parse_local(args[0])?))
             },
+            @call("mir_deinit", args) => {
+                Ok(StatementKind::Deinit(Box::new(self.parse_place(args[0])?)))
+            },
             @call("mir_retag", args) => {
                 Ok(StatementKind::Retag(RetagKind::Default, Box::new(self.parse_place(args[0])?)))
             },
@@ -141,12 +144,29 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> {
     fn parse_rvalue(&self, expr_id: ExprId) -> PResult<Rvalue<'tcx>> {
         parse_by_kind!(self, expr_id, _, "rvalue",
             @call("mir_discriminant", args) => self.parse_place(args[0]).map(Rvalue::Discriminant),
+            @call("mir_checked", args) => {
+                parse_by_kind!(self, args[0], _, "binary op",
+                    ExprKind::Binary { op, lhs, rhs } => Ok(Rvalue::CheckedBinaryOp(
+                        *op, Box::new((self.parse_operand(*lhs)?, self.parse_operand(*rhs)?))
+                    )),
+                )
+            },
+            @call("mir_len", args) => Ok(Rvalue::Len(self.parse_place(args[0])?)),
             ExprKind::Borrow { borrow_kind, arg } => Ok(
                 Rvalue::Ref(self.tcx.lifetimes.re_erased, *borrow_kind, self.parse_place(*arg)?)
             ),
             ExprKind::AddressOf { mutability, arg } => Ok(
                 Rvalue::AddressOf(*mutability, self.parse_place(*arg)?)
             ),
+            ExprKind::Binary { op, lhs, rhs } =>  Ok(
+                Rvalue::BinaryOp(*op, Box::new((self.parse_operand(*lhs)?, self.parse_operand(*rhs)?)))
+            ),
+            ExprKind::Unary { op, arg } => Ok(
+                Rvalue::UnaryOp(*op, self.parse_operand(*arg)?)
+            ),
+            ExprKind::Repeat { value, count } => Ok(
+                Rvalue::Repeat(self.parse_operand(*value)?, *count)
+            ),
             _ => self.parse_operand(expr_id).map(Rvalue::Use),
         )
     }
diff --git a/compiler/rustc_mir_build/src/build/matches/mod.rs b/compiler/rustc_mir_build/src/build/matches/mod.rs
index 0961ce11e2f..6b960ebdb16 100644
--- a/compiler/rustc_mir_build/src/build/matches/mod.rs
+++ b/compiler/rustc_mir_build/src/build/matches/mod.rs
@@ -1747,8 +1747,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 };
                 let fake_borrow_deref_ty = matched_place.ty(&self.local_decls, tcx).ty;
                 let fake_borrow_ty = tcx.mk_imm_ref(tcx.lifetimes.re_erased, fake_borrow_deref_ty);
-                let fake_borrow_temp =
-                    self.local_decls.push(LocalDecl::new(fake_borrow_ty, temp_span));
+                let mut fake_borrow_temp = LocalDecl::new(fake_borrow_ty, temp_span);
+                fake_borrow_temp.internal = self.local_decls[matched_place.local].internal;
+                fake_borrow_temp.local_info = Some(Box::new(LocalInfo::FakeBorrow));
+                let fake_borrow_temp = self.local_decls.push(fake_borrow_temp);
 
                 (matched_place, fake_borrow_temp)
             })
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index 9daf68a15f4..1655e224ddb 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -439,6 +439,10 @@ fn construct_fn<'tcx>(
     let fn_id = tcx.hir().local_def_id_to_hir_id(fn_def.did);
     let generator_kind = tcx.generator_kind(fn_def.did);
 
+    // The representation of thir for `-Zunpretty=thir-tree` relies on
+    // the entry expression being the last element of `thir.exprs`.
+    assert_eq!(expr.as_usize(), thir.exprs.len() - 1);
+
     // Figure out what primary body this item has.
     let body_id = tcx.hir().body_owned_by(fn_def.did);
     let span_with_body = tcx.hir().span_with_body(fn_id);
@@ -637,7 +641,7 @@ fn construct_error(
 
     let ty = tcx.ty_error();
     let num_params = match body_owner_kind {
-        hir::BodyOwnerKind::Fn => tcx.fn_sig(def).inputs().skip_binder().len(),
+        hir::BodyOwnerKind::Fn => tcx.fn_sig(def).skip_binder().inputs().skip_binder().len(),
         hir::BodyOwnerKind::Closure => {
             let ty = tcx.type_of(def);
             match ty.kind() {
diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs
index 7f81aef1c73..ced251267d3 100644
--- a/compiler/rustc_mir_build/src/errors.rs
+++ b/compiler/rustc_mir_build/src/errors.rs
@@ -600,32 +600,56 @@ pub struct BorrowOfMovedValue<'tcx> {
 pub struct MultipleMutBorrows {
     #[primary_span]
     pub span: Span,
-    #[label]
-    pub binding_span: Span,
     #[subdiagnostic]
-    pub occurences: Vec<MultipleMutBorrowOccurence>,
-    pub name: Ident,
+    pub occurences: Vec<Conflict>,
+}
+
+#[derive(Diagnostic)]
+#[diag(mir_build_already_borrowed)]
+pub struct AlreadyBorrowed {
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub occurences: Vec<Conflict>,
+}
+
+#[derive(Diagnostic)]
+#[diag(mir_build_already_mut_borrowed)]
+pub struct AlreadyMutBorrowed {
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub occurences: Vec<Conflict>,
+}
+
+#[derive(Diagnostic)]
+#[diag(mir_build_moved_while_borrowed)]
+pub struct MovedWhileBorrowed {
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub occurences: Vec<Conflict>,
 }
 
 #[derive(Subdiagnostic)]
-pub enum MultipleMutBorrowOccurence {
-    #[label(mutable_borrow)]
-    Mutable {
+pub enum Conflict {
+    #[label(mir_build_mutable_borrow)]
+    Mut {
         #[primary_span]
         span: Span,
-        name_mut: Ident,
+        name: Ident,
     },
-    #[label(immutable_borrow)]
-    Immutable {
+    #[label(mir_build_borrow)]
+    Ref {
         #[primary_span]
         span: Span,
-        name_immut: Ident,
+        name: Ident,
     },
-    #[label(moved)]
+    #[label(mir_build_moved)]
     Moved {
         #[primary_span]
         span: Span,
-        name_moved: Ident,
+        name: Ident,
     },
 }
 
diff --git a/compiler/rustc_mir_build/src/lib.rs b/compiler/rustc_mir_build/src/lib.rs
index a428180a4fa..94dae36154c 100644
--- a/compiler/rustc_mir_build/src/lib.rs
+++ b/compiler/rustc_mir_build/src/lib.rs
@@ -34,4 +34,5 @@ pub fn provide(providers: &mut Providers) {
     providers.thir_check_unsafety_for_const_arg = check_unsafety::thir_check_unsafety_for_const_arg;
     providers.thir_body = thir::cx::thir_body;
     providers.thir_tree = thir::cx::thir_tree;
+    providers.thir_flat = thir::cx::thir_flat;
 }
diff --git a/compiler/rustc_mir_build/src/thir/cx/mod.rs b/compiler/rustc_mir_build/src/thir/cx/mod.rs
index a355e1bdab5..10df4b22952 100644
--- a/compiler/rustc_mir_build/src/thir/cx/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/mod.rs
@@ -54,6 +54,16 @@ pub(crate) fn thir_body(
 
 pub(crate) fn thir_tree(tcx: TyCtxt<'_>, owner_def: ty::WithOptConstParam<LocalDefId>) -> String {
     match thir_body(tcx, owner_def) {
+        Ok((thir, _)) => {
+            let thir = thir.steal();
+            tcx.thir_tree_representation(&thir)
+        }
+        Err(_) => "error".into(),
+    }
+}
+
+pub(crate) fn thir_flat(tcx: TyCtxt<'_>, owner_def: ty::WithOptConstParam<LocalDefId>) -> String {
+    match thir_body(tcx, owner_def) {
         Ok((thir, _)) => format!("{:#?}", thir.steal()),
         Err(_) => "error".into(),
     }
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index 34e637f5948..2640ca56b00 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -208,9 +208,9 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
             // Don't report arm reachability of desugared `match $iter.into_iter() { iter => .. }`
             // when the iterator is an uninhabited type. unreachable_code will trigger instead.
             hir::MatchSource::ForLoopDesugar if arms.len() == 1 => {}
-            hir::MatchSource::ForLoopDesugar | hir::MatchSource::Normal => {
-                report_arm_reachability(&cx, &report)
-            }
+            hir::MatchSource::ForLoopDesugar
+            | hir::MatchSource::Normal
+            | hir::MatchSource::FormatArgs => report_arm_reachability(&cx, &report),
             // Unreachable patterns in try and await expressions occur when one of
             // the arms are an uninhabited type. Which is OK.
             hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar => {}
@@ -926,58 +926,55 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pa
     sub.each_binding(|_, hir_id, span, name| {
         match typeck_results.extract_binding_mode(sess, hir_id, span) {
             Some(ty::BindByReference(mut_inner)) => match (mut_outer, mut_inner) {
-                (Mutability::Not, Mutability::Not) => {} // Both sides are `ref`.
-                (Mutability::Mut, Mutability::Mut) => conflicts_mut_mut.push((span, name)), // 2x `ref mut`.
-                _ => conflicts_mut_ref.push((span, name)), // `ref` + `ref mut` in either direction.
+                // Both sides are `ref`.
+                (Mutability::Not, Mutability::Not) => {}
+                // 2x `ref mut`.
+                (Mutability::Mut, Mutability::Mut) => {
+                    conflicts_mut_mut.push(Conflict::Mut { span, name })
+                }
+                (Mutability::Not, Mutability::Mut) => {
+                    conflicts_mut_ref.push(Conflict::Mut { span, name })
+                }
+                (Mutability::Mut, Mutability::Not) => {
+                    conflicts_mut_ref.push(Conflict::Ref { span, name })
+                }
             },
             Some(ty::BindByValue(_)) if is_binding_by_move(cx, hir_id) => {
-                conflicts_move.push((span, name)) // `ref mut?` + by-move conflict.
+                conflicts_move.push(Conflict::Moved { span, name }) // `ref mut?` + by-move conflict.
             }
             Some(ty::BindByValue(_)) | None => {} // `ref mut?` + by-copy is fine.
         }
     });
 
+    let report_mut_mut = !conflicts_mut_mut.is_empty();
+    let report_mut_ref = !conflicts_mut_ref.is_empty();
+    let report_move_conflict = !conflicts_move.is_empty();
+
+    let mut occurences = match mut_outer {
+        Mutability::Mut => vec![Conflict::Mut { span: binding_span, name }],
+        Mutability::Not => vec![Conflict::Ref { span: binding_span, name }],
+    };
+    occurences.extend(conflicts_mut_mut);
+    occurences.extend(conflicts_mut_ref);
+    occurences.extend(conflicts_move);
+
     // Report errors if any.
-    if !conflicts_mut_mut.is_empty() {
+    if report_mut_mut {
         // Report mutability conflicts for e.g. `ref mut x @ Some(ref mut y)`.
-        let mut occurences = vec![];
-
-        for (span, name_mut) in conflicts_mut_mut {
-            occurences.push(MultipleMutBorrowOccurence::Mutable { span, name_mut });
-        }
-        for (span, name_immut) in conflicts_mut_ref {
-            occurences.push(MultipleMutBorrowOccurence::Immutable { span, name_immut });
-        }
-        for (span, name_moved) in conflicts_move {
-            occurences.push(MultipleMutBorrowOccurence::Moved { span, name_moved });
-        }
-        sess.emit_err(MultipleMutBorrows { span: pat.span, binding_span, occurences, name });
-    } else if !conflicts_mut_ref.is_empty() {
+        sess.emit_err(MultipleMutBorrows { span: pat.span, occurences });
+    } else if report_mut_ref {
         // Report mutability conflicts for e.g. `ref x @ Some(ref mut y)` or the converse.
-        let (primary, also) = match mut_outer {
-            Mutability::Mut => ("mutable", "immutable"),
-            Mutability::Not => ("immutable", "mutable"),
+        match mut_outer {
+            Mutability::Mut => {
+                sess.emit_err(AlreadyMutBorrowed { span: pat.span, occurences });
+            }
+            Mutability::Not => {
+                sess.emit_err(AlreadyBorrowed { span: pat.span, occurences });
+            }
         };
-        let msg =
-            format!("cannot borrow value as {} because it is also borrowed as {}", also, primary);
-        let mut err = sess.struct_span_err(pat.span, &msg);
-        err.span_label(binding_span, format!("{} borrow, by `{}`, occurs here", primary, name));
-        for (span, name) in conflicts_mut_ref {
-            err.span_label(span, format!("{} borrow, by `{}`, occurs here", also, name));
-        }
-        for (span, name) in conflicts_move {
-            err.span_label(span, format!("also moved into `{}` here", name));
-        }
-        err.emit();
-    } else if !conflicts_move.is_empty() {
+    } else if report_move_conflict {
         // Report by-ref and by-move conflicts, e.g. `ref x @ y`.
-        let mut err =
-            sess.struct_span_err(pat.span, "cannot move out of value because it is borrowed");
-        err.span_label(binding_span, format!("value borrowed, by `{}`, here", name));
-        for (span, name) in conflicts_move {
-            err.span_label(span, format!("value moved into `{}` here", name));
-        }
-        err.emit();
+        sess.emit_err(MovedWhileBorrowed { span: pat.span, occurences });
     }
 }
 
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
index 7f3519945c3..ff88d001351 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
@@ -192,7 +192,7 @@ impl<'tcx> ConstToPat<'tcx> {
         let obligation: PredicateObligation<'_> = predicate_for_trait_def(
             self.tcx(),
             self.param_env,
-            ObligationCause::misc(self.span, self.id),
+            ObligationCause::misc(self.span, self.id.owner.def_id),
             partial_eq_trait_id,
             0,
             [ty, ty],
diff --git a/compiler/rustc_mir_dataflow/src/impls/liveness.rs b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
index 923dc16c11b..2890fa32cc9 100644
--- a/compiler/rustc_mir_dataflow/src/impls/liveness.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
@@ -271,6 +271,7 @@ impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a> {
             | StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => None,
         };
         if let Some(destination) = destination {
diff --git a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
index 8d379b90a86..fcf0ce9d821 100644
--- a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
@@ -141,6 +141,7 @@ impl<'mir, 'tcx> crate::GenKillAnalysis<'tcx> for MaybeRequiresStorage<'mir, 'tc
             StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::FakeRead(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop
             | StatementKind::Retag(..)
             | StatementKind::Intrinsic(..)
diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
index f46fd118bde..0195693a7cb 100644
--- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
+++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
@@ -331,6 +331,7 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
             | StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs
index 0522c657939..6bdbda909d7 100644
--- a/compiler/rustc_mir_dataflow/src/value_analysis.rs
+++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs
@@ -84,7 +84,8 @@ pub trait ValueAnalysis<'tcx> {
             StatementKind::Retag(..) => {
                 // We don't track references.
             }
-            StatementKind::Nop
+            StatementKind::ConstEvalCounter
+            | StatementKind::Nop
             | StatementKind::FakeRead(..)
             | StatementKind::Coverage(..)
             | StatementKind::AscribeUserType(..) => (),
diff --git a/compiler/rustc_mir_transform/src/check_packed_ref.rs b/compiler/rustc_mir_transform/src/check_packed_ref.rs
index 51abcf51189..3e7571aa7a2 100644
--- a/compiler/rustc_mir_transform/src/check_packed_ref.rs
+++ b/compiler/rustc_mir_transform/src/check_packed_ref.rs
@@ -1,17 +1,11 @@
-use rustc_hir::def_id::LocalDefId;
 use rustc_middle::mir::visit::{PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::lint::builtin::UNALIGNED_REFERENCES;
 
 use crate::util;
 use crate::MirLint;
 
-pub(crate) fn provide(providers: &mut Providers) {
-    *providers = Providers { unsafe_derive_on_repr_packed, ..*providers };
-}
-
 pub struct CheckPackedRef;
 
 impl<'tcx> MirLint<'tcx> for CheckPackedRef {
@@ -30,32 +24,6 @@ struct PackedRefChecker<'a, 'tcx> {
     source_info: SourceInfo,
 }
 
-fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
-    let lint_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-
-    // FIXME: when we make this a hard error, this should have its
-    // own error code.
-
-    let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
-        "with type or const parameters"
-    } else {
-        "that does not derive `Copy`"
-    };
-    let message = format!(
-        "`{}` can't be derived on this `#[repr(packed)]` struct {}",
-        tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
-        extra
-    );
-
-    tcx.struct_span_lint_hir(
-        UNALIGNED_REFERENCES,
-        lint_hir_id,
-        tcx.def_span(def_id),
-        message,
-        |lint| lint,
-    );
-}
-
 impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         // Make sure we know where in the MIR we are.
@@ -73,14 +41,13 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
         if context.is_borrow() {
             if util::is_disaligned(self.tcx, self.body, self.param_env, *place) {
                 let def_id = self.body.source.instance.def_id();
-                if let Some(impl_def_id) = self
-                    .tcx
-                    .impl_of_method(def_id)
-                    .filter(|&def_id| self.tcx.is_builtin_derive(def_id))
+                if let Some(impl_def_id) = self.tcx.impl_of_method(def_id)
+                    && self.tcx.is_builtin_derive(impl_def_id)
                 {
-                    // If a method is defined in the local crate,
-                    // the impl containing that method should also be.
-                    self.tcx.ensure().unsafe_derive_on_repr_packed(impl_def_id.expect_local());
+                    // If we ever reach here it means that the generated derive
+                    // code is somehow doing an unaligned reference, which it
+                    // shouldn't do.
+                    unreachable!();
                 } else {
                     let source_info = self.source_info;
                     let lint_root = self.body.source_scopes[source_info.scope]
diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs
index adf6ae4c727..8afa53313fc 100644
--- a/compiler/rustc_mir_transform/src/check_unsafety.rs
+++ b/compiler/rustc_mir_transform/src/check_unsafety.rs
@@ -104,6 +104,7 @@ impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> {
             | StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {
                 // safe (at least as emitted during MIR construction)
             }
@@ -445,7 +446,7 @@ impl<'tcx> intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'_, 'tcx> {
         _fd: &'tcx hir::FnDecl<'tcx>,
         b: hir::BodyId,
         _s: rustc_span::Span,
-        _id: HirId,
+        _id: LocalDefId,
     ) {
         if matches!(fk, intravisit::FnKind::Closure) {
             self.visit_body(self.tcx.hir().body(b))
diff --git a/compiler/rustc_mir_transform/src/const_goto.rs b/compiler/rustc_mir_transform/src/const_goto.rs
index 40eefda4f07..da101ca7ad2 100644
--- a/compiler/rustc_mir_transform/src/const_goto.rs
+++ b/compiler/rustc_mir_transform/src/const_goto.rs
@@ -57,6 +57,15 @@ impl<'tcx> MirPass<'tcx> for ConstGoto {
 }
 
 impl<'tcx> Visitor<'tcx> for ConstGotoOptimizationFinder<'_, 'tcx> {
+    fn visit_basic_block_data(&mut self, block: BasicBlock, data: &BasicBlockData<'tcx>) {
+        if data.is_cleanup {
+            // Because of the restrictions around control flow in cleanup blocks, we don't perform
+            // this optimization at all in such blocks.
+            return;
+        }
+        self.super_basic_block_data(block, data);
+    }
+
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         let _: Option<_> = try {
             let target = terminator.kind.as_goto()?;
diff --git a/compiler/rustc_mir_transform/src/copy_prop.rs b/compiler/rustc_mir_transform/src/copy_prop.rs
new file mode 100644
index 00000000000..182b3015dd7
--- /dev/null
+++ b/compiler/rustc_mir_transform/src/copy_prop.rs
@@ -0,0 +1,178 @@
+use rustc_index::bit_set::BitSet;
+use rustc_index::vec::IndexVec;
+use rustc_middle::mir::visit::*;
+use rustc_middle::mir::*;
+use rustc_middle::ty::TyCtxt;
+use rustc_mir_dataflow::impls::borrowed_locals;
+
+use crate::ssa::SsaLocals;
+use crate::MirPass;
+
+/// Unify locals that copy each other.
+///
+/// We consider patterns of the form
+///   _a = rvalue
+///   _b = move? _a
+///   _c = move? _a
+///   _d = move? _c
+/// where each of the locals is only assigned once.
+///
+/// We want to replace all those locals by `_a`, either copied or moved.
+pub struct CopyProp;
+
+impl<'tcx> MirPass<'tcx> for CopyProp {
+    fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
+        sess.mir_opt_level() >= 4
+    }
+
+    #[instrument(level = "trace", skip(self, tcx, body))]
+    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+        debug!(def_id = ?body.source.def_id());
+        propagate_ssa(tcx, body);
+    }
+}
+
+fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
+    let borrowed_locals = borrowed_locals(body);
+    let ssa = SsaLocals::new(tcx, param_env, body, &borrowed_locals);
+
+    let fully_moved = fully_moved_locals(&ssa, body);
+    debug!(?fully_moved);
+
+    let mut storage_to_remove = BitSet::new_empty(fully_moved.domain_size());
+    for (local, &head) in ssa.copy_classes().iter_enumerated() {
+        if local != head {
+            storage_to_remove.insert(head);
+        }
+    }
+
+    let any_replacement = ssa.copy_classes().iter_enumerated().any(|(l, &h)| l != h);
+
+    Replacer {
+        tcx,
+        copy_classes: &ssa.copy_classes(),
+        fully_moved,
+        borrowed_locals,
+        storage_to_remove,
+    }
+    .visit_body_preserves_cfg(body);
+
+    if any_replacement {
+        crate::simplify::remove_unused_definitions(body);
+    }
+}
+
+/// `SsaLocals` computed equivalence classes between locals considering copy/move assignments.
+///
+/// This function also returns whether all the `move?` in the pattern are `move` and not copies.
+/// A local which is in the bitset can be replaced by `move _a`. Otherwise, it must be
+/// replaced by `copy _a`, as we cannot move multiple times from `_a`.
+///
+/// If an operand copies `_c`, it must happen before the assignment `_d = _c`, otherwise it is UB.
+/// This means that replacing it by a copy of `_a` if ok, since this copy happens before `_c` is
+/// moved, and therefore that `_d` is moved.
+#[instrument(level = "trace", skip(ssa, body))]
+fn fully_moved_locals(ssa: &SsaLocals, body: &Body<'_>) -> BitSet<Local> {
+    let mut fully_moved = BitSet::new_filled(body.local_decls.len());
+
+    for (_, rvalue) in ssa.assignments(body) {
+        let (Rvalue::Use(Operand::Copy(place) | Operand::Move(place)) | Rvalue::CopyForDeref(place))
+            = rvalue
+        else { continue };
+
+        let Some(rhs) = place.as_local() else { continue };
+        if !ssa.is_ssa(rhs) {
+            continue;
+        }
+
+        if let Rvalue::Use(Operand::Copy(_)) | Rvalue::CopyForDeref(_) = rvalue {
+            fully_moved.remove(rhs);
+        }
+    }
+
+    ssa.meet_copy_equivalence(&mut fully_moved);
+
+    fully_moved
+}
+
+/// Utility to help performing subtitution of `*pattern` by `target`.
+struct Replacer<'a, 'tcx> {
+    tcx: TyCtxt<'tcx>,
+    fully_moved: BitSet<Local>,
+    storage_to_remove: BitSet<Local>,
+    borrowed_locals: BitSet<Local>,
+    copy_classes: &'a IndexVec<Local, Local>,
+}
+
+impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
+    fn tcx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
+
+    fn visit_local(&mut self, local: &mut Local, ctxt: PlaceContext, _: Location) {
+        let new_local = self.copy_classes[*local];
+        match ctxt {
+            // Do not modify the local in storage statements.
+            PlaceContext::NonUse(NonUseContext::StorageLive | NonUseContext::StorageDead) => {}
+            // The local should have been marked as non-SSA.
+            PlaceContext::MutatingUse(_) => assert_eq!(*local, new_local),
+            // We access the value.
+            _ => *local = new_local,
+        }
+    }
+
+    fn visit_place(&mut self, place: &mut Place<'tcx>, ctxt: PlaceContext, loc: Location) {
+        if let Some(new_projection) = self.process_projection(&place.projection, loc) {
+            place.projection = self.tcx().intern_place_elems(&new_projection);
+        }
+
+        let observes_address = match ctxt {
+            PlaceContext::NonMutatingUse(
+                NonMutatingUseContext::SharedBorrow
+                | NonMutatingUseContext::ShallowBorrow
+                | NonMutatingUseContext::UniqueBorrow
+                | NonMutatingUseContext::AddressOf,
+            ) => true,
+            // For debuginfo, merging locals is ok.
+            PlaceContext::NonUse(NonUseContext::VarDebugInfo) => {
+                self.borrowed_locals.contains(place.local)
+            }
+            _ => false,
+        };
+        if observes_address && !place.is_indirect() {
+            // We observe the address of `place.local`. Do not replace it.
+        } else {
+            self.visit_local(
+                &mut place.local,
+                PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
+                loc,
+            )
+        }
+    }
+
+    fn visit_operand(&mut self, operand: &mut Operand<'tcx>, loc: Location) {
+        if let Operand::Move(place) = *operand
+            && let Some(local) = place.as_local()
+            && !self.fully_moved.contains(local)
+        {
+            *operand = Operand::Copy(place);
+        }
+        self.super_operand(operand, loc);
+    }
+
+    fn visit_statement(&mut self, stmt: &mut Statement<'tcx>, loc: Location) {
+        if let StatementKind::StorageDead(l) = stmt.kind
+            && self.storage_to_remove.contains(l)
+        {
+            stmt.make_nop();
+        } else if let StatementKind::Assign(box (ref place, ref mut rvalue)) = stmt.kind
+            && place.as_local().is_some()
+        {
+            // Do not replace assignments.
+            self.visit_rvalue(rvalue, loc)
+        } else {
+            self.super_statement(stmt, loc);
+        }
+    }
+}
diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs
index 45de0c28035..658e01d9310 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters.rs
@@ -520,7 +520,7 @@ impl<'a> BcbCounters<'a> {
                 let mut found_loop_exit = false;
                 for &branch in branches.iter() {
                     if backedge_from_bcbs.iter().any(|&backedge_from_bcb| {
-                        self.bcb_is_dominated_by(backedge_from_bcb, branch.target_bcb)
+                        self.bcb_dominates(branch.target_bcb, backedge_from_bcb)
                     }) {
                         if let Some(reloop_branch) = some_reloop_branch {
                             if reloop_branch.counter(&self.basic_coverage_blocks).is_none() {
@@ -603,8 +603,8 @@ impl<'a> BcbCounters<'a> {
     }
 
     #[inline]
-    fn bcb_is_dominated_by(&self, node: BasicCoverageBlock, dom: BasicCoverageBlock) -> bool {
-        self.basic_coverage_blocks.is_dominated_by(node, dom)
+    fn bcb_dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
+        self.basic_coverage_blocks.dominates(dom, node)
     }
 
     #[inline]
diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs
index 78d28f1ebab..a2671eef2e9 100644
--- a/compiler/rustc_mir_transform/src/coverage/graph.rs
+++ b/compiler/rustc_mir_transform/src/coverage/graph.rs
@@ -209,8 +209,8 @@ impl CoverageGraph {
     }
 
     #[inline(always)]
-    pub fn is_dominated_by(&self, node: BasicCoverageBlock, dom: BasicCoverageBlock) -> bool {
-        self.dominators.as_ref().unwrap().is_dominated_by(node, dom)
+    pub fn dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
+        self.dominators.as_ref().unwrap().dominates(dom, node)
     }
 
     #[inline(always)]
@@ -312,7 +312,7 @@ rustc_index::newtype_index! {
 /// to the BCB's primary counter or expression).
 ///
 /// The BCB CFG is critical to simplifying the coverage analysis by ensuring graph path-based
-/// queries (`is_dominated_by()`, `predecessors`, `successors`, etc.) have branch (control flow)
+/// queries (`dominates()`, `predecessors`, `successors`, etc.) have branch (control flow)
 /// significance.
 #[derive(Debug, Clone)]
 pub(super) struct BasicCoverageBlockData {
@@ -594,7 +594,7 @@ impl TraverseCoverageGraphWithLoops {
                 // branching block would have given an `Expression` (or vice versa).
                 let (some_successor_to_add, some_loop_header) =
                     if let Some((_, loop_header)) = context.loop_backedges {
-                        if basic_coverage_blocks.is_dominated_by(successor, loop_header) {
+                        if basic_coverage_blocks.dominates(loop_header, successor) {
                             (Some(successor), Some(loop_header))
                         } else {
                             (None, None)
@@ -666,15 +666,15 @@ pub(super) fn find_loop_backedges(
     //
     // The overall complexity appears to be comparable to many other MIR transform algorithms, and I
     // don't expect that this function is creating a performance hot spot, but if this becomes an
-    // issue, there may be ways to optimize the `is_dominated_by` algorithm (as indicated by an
+    // issue, there may be ways to optimize the `dominates` algorithm (as indicated by an
     // existing `FIXME` comment in that code), or possibly ways to optimize it's usage here, perhaps
     // by keeping track of results for visited `BasicCoverageBlock`s if they can be used to short
-    // circuit downstream `is_dominated_by` checks.
+    // circuit downstream `dominates` checks.
     //
     // For now, that kind of optimization seems unnecessarily complicated.
     for (bcb, _) in basic_coverage_blocks.iter_enumerated() {
         for &successor in &basic_coverage_blocks.successors[bcb] {
-            if basic_coverage_blocks.is_dominated_by(bcb, successor) {
+            if basic_coverage_blocks.dominates(successor, bcb) {
                 let loop_header = successor;
                 let backedge_from_bcb = bcb;
                 debug!(
diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs
index 1468afc6456..9a617159813 100644
--- a/compiler/rustc_mir_transform/src/coverage/mod.rs
+++ b/compiler/rustc_mir_transform/src/coverage/mod.rs
@@ -540,7 +540,8 @@ fn fn_sig_and_body(
     // FIXME(#79625): Consider improving MIR to provide the information needed, to avoid going back
     // to HIR for it.
     let hir_node = tcx.hir().get_if_local(def_id).expect("expected DefId is local");
-    let fn_body_id = hir::map::associated_body(hir_node).expect("HIR node is a function with body");
+    let (_, fn_body_id) =
+        hir::map::associated_body(hir_node).expect("HIR node is a function with body");
     (hir_node.fn_sig(), tcx.hir().body(fn_body_id))
 }
 
diff --git a/compiler/rustc_mir_transform/src/coverage/spans.rs b/compiler/rustc_mir_transform/src/coverage/spans.rs
index c5434840453..f973c1ed28f 100644
--- a/compiler/rustc_mir_transform/src/coverage/spans.rs
+++ b/compiler/rustc_mir_transform/src/coverage/spans.rs
@@ -63,7 +63,7 @@ impl CoverageStatement {
 /// Note: A `CoverageStatement` merged into another CoverageSpan may come from a `BasicBlock` that
 /// is not part of the `CoverageSpan` bcb if the statement was included because it's `Span` matches
 /// or is subsumed by the `Span` associated with this `CoverageSpan`, and it's `BasicBlock`
-/// `is_dominated_by()` the `BasicBlock`s in this `CoverageSpan`.
+/// `dominates()` the `BasicBlock`s in this `CoverageSpan`.
 #[derive(Debug, Clone)]
 pub(super) struct CoverageSpan {
     pub span: Span,
@@ -705,12 +705,12 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
     fn hold_pending_dups_unless_dominated(&mut self) {
         // Equal coverage spans are ordered by dominators before dominated (if any), so it should be
         // impossible for `curr` to dominate any previous `CoverageSpan`.
-        debug_assert!(!self.span_bcb_is_dominated_by(self.prev(), self.curr()));
+        debug_assert!(!self.span_bcb_dominates(self.curr(), self.prev()));
 
         let initial_pending_count = self.pending_dups.len();
         if initial_pending_count > 0 {
             let mut pending_dups = self.pending_dups.split_off(0);
-            pending_dups.retain(|dup| !self.span_bcb_is_dominated_by(self.curr(), dup));
+            pending_dups.retain(|dup| !self.span_bcb_dominates(dup, self.curr()));
             self.pending_dups.append(&mut pending_dups);
             if self.pending_dups.len() < initial_pending_count {
                 debug!(
@@ -721,7 +721,7 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
             }
         }
 
-        if self.span_bcb_is_dominated_by(self.curr(), self.prev()) {
+        if self.span_bcb_dominates(self.prev(), self.curr()) {
             debug!(
                 "  different bcbs but SAME spans, and prev dominates curr. Discard prev={:?}",
                 self.prev()
@@ -787,8 +787,8 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
         }
     }
 
-    fn span_bcb_is_dominated_by(&self, covspan: &CoverageSpan, dom_covspan: &CoverageSpan) -> bool {
-        self.basic_coverage_blocks.is_dominated_by(covspan.bcb, dom_covspan.bcb)
+    fn span_bcb_dominates(&self, dom_covspan: &CoverageSpan, covspan: &CoverageSpan) -> bool {
+        self.basic_coverage_blocks.dominates(dom_covspan.bcb, covspan.bcb)
     }
 }
 
@@ -802,6 +802,8 @@ pub(super) fn filtered_statement_span(statement: &Statement<'_>) -> Option<Span>
         | StatementKind::StorageDead(_)
         // Coverage should not be encountered, but don't inject coverage coverage
         | StatementKind::Coverage(_)
+        // Ignore `ConstEvalCounter`s
+        | StatementKind::ConstEvalCounter
         // Ignore `Nop`s
         | StatementKind::Nop => None,
 
diff --git a/compiler/rustc_mir_transform/src/ctfe_limit.rs b/compiler/rustc_mir_transform/src/ctfe_limit.rs
new file mode 100644
index 00000000000..7d127032179
--- /dev/null
+++ b/compiler/rustc_mir_transform/src/ctfe_limit.rs
@@ -0,0 +1,59 @@
+//! A pass that inserts the `ConstEvalCounter` instruction into any blocks that have a back edge
+//! (thus indicating there is a loop in the CFG), or whose terminator is a function call.
+use crate::MirPass;
+
+use rustc_data_structures::graph::dominators::Dominators;
+use rustc_middle::mir::{
+    BasicBlock, BasicBlockData, Body, Statement, StatementKind, TerminatorKind,
+};
+use rustc_middle::ty::TyCtxt;
+
+pub struct CtfeLimit;
+
+impl<'tcx> MirPass<'tcx> for CtfeLimit {
+    #[instrument(skip(self, _tcx, body))]
+    fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+        let doms = body.basic_blocks.dominators();
+        let indices: Vec<BasicBlock> = body
+            .basic_blocks
+            .iter_enumerated()
+            .filter_map(|(node, node_data)| {
+                if matches!(node_data.terminator().kind, TerminatorKind::Call { .. })
+                    // Back edges in a CFG indicate loops
+                    || has_back_edge(&doms, node, &node_data)
+                {
+                    Some(node)
+                } else {
+                    None
+                }
+            })
+            .collect();
+        for index in indices {
+            insert_counter(
+                body.basic_blocks_mut()
+                    .get_mut(index)
+                    .expect("basic_blocks index {index} should exist"),
+            );
+        }
+    }
+}
+
+fn has_back_edge(
+    doms: &Dominators<BasicBlock>,
+    node: BasicBlock,
+    node_data: &BasicBlockData<'_>,
+) -> bool {
+    if !doms.is_reachable(node) {
+        return false;
+    }
+    // Check if any of the dominators of the node are also the node's successor.
+    doms.dominators(node)
+        .any(|dom| node_data.terminator().successors().into_iter().any(|succ| succ == dom))
+}
+
+fn insert_counter(basic_block_data: &mut BasicBlockData<'_>) {
+    basic_block_data.statements.push(Statement {
+        source_info: basic_block_data.terminator().source_info,
+        kind: StatementKind::ConstEvalCounter,
+    });
+}
diff --git a/compiler/rustc_mir_transform/src/dead_store_elimination.rs b/compiler/rustc_mir_transform/src/dead_store_elimination.rs
index 09546330cec..9dbfb089dc6 100644
--- a/compiler/rustc_mir_transform/src/dead_store_elimination.rs
+++ b/compiler/rustc_mir_transform/src/dead_store_elimination.rs
@@ -53,6 +53,7 @@ pub fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>, borrowed: &BitS
                 | StatementKind::StorageDead(_)
                 | StatementKind::Coverage(_)
                 | StatementKind::Intrinsic(_)
+                | StatementKind::ConstEvalCounter
                 | StatementKind::Nop => (),
 
                 StatementKind::FakeRead(_) | StatementKind::AscribeUserType(_, _) => {
diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs
index 08e296a8371..5c5baa68e58 100644
--- a/compiler/rustc_mir_transform/src/dest_prop.rs
+++ b/compiler/rustc_mir_transform/src/dest_prop.rs
@@ -328,7 +328,8 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Merger<'a, 'tcx> {
         match &statement.kind {
             StatementKind::Assign(box (dest, rvalue)) => {
                 match rvalue {
-                    Rvalue::Use(Operand::Copy(place) | Operand::Move(place)) => {
+                    Rvalue::CopyForDeref(place)
+                    | Rvalue::Use(Operand::Copy(place) | Operand::Move(place)) => {
                         // These might've been turned into self-assignments by the replacement
                         // (this includes the original statement we wanted to eliminate).
                         if dest == place {
@@ -577,6 +578,7 @@ impl WriteInfo {
                 self.add_place(**place);
             }
             StatementKind::Intrinsic(_)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop
             | StatementKind::Coverage(_)
             | StatementKind::StorageLive(_)
@@ -754,7 +756,7 @@ impl<'tcx> Visitor<'tcx> for FindAssignments<'_, '_, 'tcx> {
     fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) {
         if let StatementKind::Assign(box (
             lhs,
-            Rvalue::Use(Operand::Copy(rhs) | Operand::Move(rhs)),
+            Rvalue::CopyForDeref(rhs) | Rvalue::Use(Operand::Copy(rhs) | Operand::Move(rhs)),
         )) = &statement.kind
         {
             let Some((src, dest)) = places_to_candidate_pair(*lhs, *rhs, self.body) else {
diff --git a/compiler/rustc_mir_transform/src/function_item_references.rs b/compiler/rustc_mir_transform/src/function_item_references.rs
index b708d780b70..aa19b1fdb5e 100644
--- a/compiler/rustc_mir_transform/src/function_item_references.rs
+++ b/compiler/rustc_mir_transform/src/function_item_references.rs
@@ -79,7 +79,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
         for bound in bounds {
             if let Some(bound_ty) = self.is_pointer_trait(&bound.kind().skip_binder()) {
                 // Get the argument types as they appear in the function signature.
-                let arg_defs = self.tcx.fn_sig(def_id).skip_binder().inputs();
+                let arg_defs = self.tcx.fn_sig(def_id).subst_identity().skip_binder().inputs();
                 for (arg_num, arg_def) in arg_defs.iter().enumerate() {
                     // For all types reachable from the argument type in the fn sig
                     for generic_inner_ty in arg_def.walk() {
@@ -161,7 +161,8 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
             .as_ref()
             .assert_crate_local()
             .lint_root;
-        let fn_sig = self.tcx.fn_sig(fn_id);
+        // FIXME: use existing printing routines to print the function signature
+        let fn_sig = self.tcx.fn_sig(fn_id).subst(self.tcx, fn_substs);
         let unsafety = fn_sig.unsafety().prefix_str();
         let abi = match fn_sig.abi() {
             Abi::Rust => String::from(""),
diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs
index 39c61a34afc..5624e312da1 100644
--- a/compiler/rustc_mir_transform/src/generator.rs
+++ b/compiler/rustc_mir_transform/src/generator.rs
@@ -54,7 +54,8 @@ use crate::deref_separator::deref_finder;
 use crate::simplify;
 use crate::util::expand_aggregate;
 use crate::MirPass;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::pluralize;
 use rustc_hir as hir;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::GeneratorKind;
@@ -70,6 +71,9 @@ use rustc_mir_dataflow::impls::{
 };
 use rustc_mir_dataflow::storage::always_storage_live_locals;
 use rustc_mir_dataflow::{self, Analysis};
+use rustc_span::def_id::DefId;
+use rustc_span::symbol::sym;
+use rustc_span::Span;
 use rustc_target::abi::VariantIdx;
 use rustc_target::spec::PanicStrategy;
 use std::{iter, ops};
@@ -854,7 +858,7 @@ fn sanitize_witness<'tcx>(
     body: &Body<'tcx>,
     witness: Ty<'tcx>,
     upvars: Vec<Ty<'tcx>>,
-    saved_locals: &GeneratorSavedLocals,
+    layout: &GeneratorLayout<'tcx>,
 ) {
     let did = body.source.def_id();
     let param_env = tcx.param_env(did);
@@ -873,31 +877,36 @@ fn sanitize_witness<'tcx>(
         }
     };
 
-    for (local, decl) in body.local_decls.iter_enumerated() {
-        // Ignore locals which are internal or not saved between yields.
-        if !saved_locals.contains(local) || decl.internal {
+    let mut mismatches = Vec::new();
+    for fty in &layout.field_tys {
+        if fty.ignore_for_traits {
             continue;
         }
-        let decl_ty = tcx.normalize_erasing_regions(param_env, decl.ty);
+        let decl_ty = tcx.normalize_erasing_regions(param_env, fty.ty);
 
         // Sanity check that typeck knows about the type of locals which are
         // live across a suspension point
         if !allowed.contains(&decl_ty) && !allowed_upvars.contains(&decl_ty) {
-            span_bug!(
-                body.span,
-                "Broken MIR: generator contains type {} in MIR, \
-                       but typeck only knows about {} and {:?}",
-                decl_ty,
-                allowed,
-                allowed_upvars
-            );
+            mismatches.push(decl_ty);
         }
     }
+
+    if !mismatches.is_empty() {
+        span_bug!(
+            body.span,
+            "Broken MIR: generator contains type {:?} in MIR, \
+                       but typeck only knows about {} and {:?}",
+            mismatches,
+            allowed,
+            allowed_upvars
+        );
+    }
 }
 
 fn compute_layout<'tcx>(
+    tcx: TyCtxt<'tcx>,
     liveness: LivenessInfo,
-    body: &mut Body<'tcx>,
+    body: &Body<'tcx>,
 ) -> (
     FxHashMap<Local, (Ty<'tcx>, VariantIdx, usize)>,
     GeneratorLayout<'tcx>,
@@ -915,9 +924,33 @@ fn compute_layout<'tcx>(
     let mut locals = IndexVec::<GeneratorSavedLocal, _>::new();
     let mut tys = IndexVec::<GeneratorSavedLocal, _>::new();
     for (saved_local, local) in saved_locals.iter_enumerated() {
-        locals.push(local);
-        tys.push(body.local_decls[local].ty);
         debug!("generator saved local {:?} => {:?}", saved_local, local);
+
+        locals.push(local);
+        let decl = &body.local_decls[local];
+        debug!(?decl);
+
+        let ignore_for_traits = if tcx.sess.opts.unstable_opts.drop_tracking_mir {
+            match decl.local_info {
+                // Do not include raw pointers created from accessing `static` items, as those could
+                // well be re-created by another access to the same static.
+                Some(box LocalInfo::StaticRef { is_thread_local, .. }) => !is_thread_local,
+                // Fake borrows are only read by fake reads, so do not have any reality in
+                // post-analysis MIR.
+                Some(box LocalInfo::FakeBorrow) => true,
+                _ => false,
+            }
+        } else {
+            // FIXME(#105084) HIR-based drop tracking does not account for all the temporaries that
+            // MIR building may introduce. This leads to wrongly ignored types, but this is
+            // necessary for internal consistency and to avoid ICEs.
+            decl.internal
+        };
+        let decl =
+            GeneratorSavedTy { ty: decl.ty, source_info: decl.source_info, ignore_for_traits };
+        debug!(?decl);
+
+        tys.push(decl);
     }
 
     // Leave empty variants for the UNRESUMED, RETURNED, and POISONED states.
@@ -947,7 +980,7 @@ fn compute_layout<'tcx>(
             // just use the first one here. That's fine; fields do not move
             // around inside generators, so it doesn't matter which variant
             // index we access them by.
-            remap.entry(locals[saved_local]).or_insert((tys[saved_local], variant_index, idx));
+            remap.entry(locals[saved_local]).or_insert((tys[saved_local].ty, variant_index, idx));
         }
         variant_fields.push(fields);
         variant_source_info.push(source_info_at_suspension_points[suspension_point_idx]);
@@ -957,6 +990,7 @@ fn compute_layout<'tcx>(
 
     let layout =
         GeneratorLayout { field_tys: tys, variant_fields, variant_source_info, storage_conflicts };
+    debug!(?layout);
 
     (remap, layout, storage_liveness)
 }
@@ -1351,6 +1385,42 @@ fn create_cases<'tcx>(
         .collect()
 }
 
+#[instrument(level = "debug", skip(tcx), ret)]
+pub(crate) fn mir_generator_witnesses<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def_id: DefId,
+) -> GeneratorLayout<'tcx> {
+    assert!(tcx.sess.opts.unstable_opts.drop_tracking_mir);
+    let def_id = def_id.expect_local();
+
+    let (body, _) = tcx.mir_promoted(ty::WithOptConstParam::unknown(def_id));
+    let body = body.borrow();
+    let body = &*body;
+
+    // The first argument is the generator type passed by value
+    let gen_ty = body.local_decls[ty::CAPTURE_STRUCT_LOCAL].ty;
+
+    // Get the interior types and substs which typeck computed
+    let movable = match *gen_ty.kind() {
+        ty::Generator(_, _, movability) => movability == hir::Movability::Movable,
+        _ => span_bug!(body.span, "unexpected generator type {}", gen_ty),
+    };
+
+    // When first entering the generator, move the resume argument into its new local.
+    let always_live_locals = always_storage_live_locals(&body);
+
+    let liveness_info = locals_live_across_suspend_points(tcx, body, &always_live_locals, movable);
+
+    // Extract locals which are live across suspension point into `layout`
+    // `remap` gives a mapping from local indices onto generator struct indices
+    // `storage_liveness` tells us which locals have live storage at suspension points
+    let (_, generator_layout, _) = compute_layout(tcx, liveness_info, body);
+
+    check_suspend_tys(tcx, &generator_layout, &body);
+
+    generator_layout
+}
+
 impl<'tcx> MirPass<'tcx> for StateTransform {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let Some(yield_ty) = body.yield_ty() else {
@@ -1363,14 +1433,14 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
         // The first argument is the generator type passed by value
         let gen_ty = body.local_decls.raw[1].ty;
 
-        // Get the interior types and substs which typeck computed
-        let (upvars, interior, discr_ty, movable) = match *gen_ty.kind() {
+        // Get the discriminant type and substs which typeck computed
+        let (discr_ty, upvars, interior, movable) = match *gen_ty.kind() {
             ty::Generator(_, substs, movability) => {
                 let substs = substs.as_generator();
                 (
-                    substs.upvar_tys().collect(),
-                    substs.witness(),
                     substs.discr_ty(tcx),
+                    substs.upvar_tys().collect::<Vec<_>>(),
+                    substs.witness(),
                     movability == hir::Movability::Movable,
                 )
             }
@@ -1434,8 +1504,6 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
         let liveness_info =
             locals_live_across_suspend_points(tcx, body, &always_live_locals, movable);
 
-        sanitize_witness(tcx, body, interior, upvars, &liveness_info.saved_locals);
-
         if tcx.sess.opts.unstable_opts.validate_mir {
             let mut vis = EnsureGeneratorFieldAssignmentsNeverAlias {
                 assigned_local: None,
@@ -1449,7 +1517,13 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
         // Extract locals which are live across suspension point into `layout`
         // `remap` gives a mapping from local indices onto generator struct indices
         // `storage_liveness` tells us which locals have live storage at suspension points
-        let (remap, layout, storage_liveness) = compute_layout(liveness_info, body);
+        let (remap, layout, storage_liveness) = compute_layout(tcx, liveness_info, body);
+
+        if tcx.sess.opts.unstable_opts.validate_mir
+            && !tcx.sess.opts.unstable_opts.drop_tracking_mir
+        {
+            sanitize_witness(tcx, body, interior, upvars, &layout);
+        }
 
         let can_return = can_return(tcx, body, tcx.param_env(body.source.def_id()));
 
@@ -1583,6 +1657,7 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> {
             | StatementKind::AscribeUserType(..)
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
         }
     }
@@ -1631,3 +1706,212 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> {
         }
     }
 }
+
+fn check_suspend_tys<'tcx>(tcx: TyCtxt<'tcx>, layout: &GeneratorLayout<'tcx>, body: &Body<'tcx>) {
+    let mut linted_tys = FxHashSet::default();
+
+    // We want a user-facing param-env.
+    let param_env = tcx.param_env(body.source.def_id());
+
+    for (variant, yield_source_info) in
+        layout.variant_fields.iter().zip(&layout.variant_source_info)
+    {
+        debug!(?variant);
+        for &local in variant {
+            let decl = &layout.field_tys[local];
+            debug!(?decl);
+
+            if !decl.ignore_for_traits && linted_tys.insert(decl.ty) {
+                let Some(hir_id) = decl.source_info.scope.lint_root(&body.source_scopes) else { continue };
+
+                check_must_not_suspend_ty(
+                    tcx,
+                    decl.ty,
+                    hir_id,
+                    param_env,
+                    SuspendCheckData {
+                        source_span: decl.source_info.span,
+                        yield_span: yield_source_info.span,
+                        plural_len: 1,
+                        ..Default::default()
+                    },
+                );
+            }
+        }
+    }
+}
+
+#[derive(Default)]
+struct SuspendCheckData<'a> {
+    source_span: Span,
+    yield_span: Span,
+    descr_pre: &'a str,
+    descr_post: &'a str,
+    plural_len: usize,
+}
+
+// Returns whether it emitted a diagnostic or not
+// Note that this fn and the proceeding one are based on the code
+// for creating must_use diagnostics
+//
+// Note that this technique was chosen over things like a `Suspend` marker trait
+// as it is simpler and has precedent in the compiler
+fn check_must_not_suspend_ty<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ty: Ty<'tcx>,
+    hir_id: hir::HirId,
+    param_env: ty::ParamEnv<'tcx>,
+    data: SuspendCheckData<'_>,
+) -> bool {
+    if ty.is_unit() {
+        return false;
+    }
+
+    let plural_suffix = pluralize!(data.plural_len);
+
+    debug!("Checking must_not_suspend for {}", ty);
+
+    match *ty.kind() {
+        ty::Adt(..) if ty.is_box() => {
+            let boxed_ty = ty.boxed_ty();
+            let descr_pre = &format!("{}boxed ", data.descr_pre);
+            check_must_not_suspend_ty(
+                tcx,
+                boxed_ty,
+                hir_id,
+                param_env,
+                SuspendCheckData { descr_pre, ..data },
+            )
+        }
+        ty::Adt(def, _) => check_must_not_suspend_def(tcx, def.did(), hir_id, data),
+        // FIXME: support adding the attribute to TAITs
+        ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
+            let mut has_emitted = false;
+            for &(predicate, _) in tcx.explicit_item_bounds(def) {
+                // We only look at the `DefId`, so it is safe to skip the binder here.
+                if let ty::PredicateKind::Clause(ty::Clause::Trait(ref poly_trait_predicate)) =
+                    predicate.kind().skip_binder()
+                {
+                    let def_id = poly_trait_predicate.trait_ref.def_id;
+                    let descr_pre = &format!("{}implementer{} of ", data.descr_pre, plural_suffix);
+                    if check_must_not_suspend_def(
+                        tcx,
+                        def_id,
+                        hir_id,
+                        SuspendCheckData { descr_pre, ..data },
+                    ) {
+                        has_emitted = true;
+                        break;
+                    }
+                }
+            }
+            has_emitted
+        }
+        ty::Dynamic(binder, _, _) => {
+            let mut has_emitted = false;
+            for predicate in binder.iter() {
+                if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() {
+                    let def_id = trait_ref.def_id;
+                    let descr_post = &format!(" trait object{}{}", plural_suffix, data.descr_post);
+                    if check_must_not_suspend_def(
+                        tcx,
+                        def_id,
+                        hir_id,
+                        SuspendCheckData { descr_post, ..data },
+                    ) {
+                        has_emitted = true;
+                        break;
+                    }
+                }
+            }
+            has_emitted
+        }
+        ty::Tuple(fields) => {
+            let mut has_emitted = false;
+            for (i, ty) in fields.iter().enumerate() {
+                let descr_post = &format!(" in tuple element {i}");
+                if check_must_not_suspend_ty(
+                    tcx,
+                    ty,
+                    hir_id,
+                    param_env,
+                    SuspendCheckData { descr_post, ..data },
+                ) {
+                    has_emitted = true;
+                }
+            }
+            has_emitted
+        }
+        ty::Array(ty, len) => {
+            let descr_pre = &format!("{}array{} of ", data.descr_pre, plural_suffix);
+            check_must_not_suspend_ty(
+                tcx,
+                ty,
+                hir_id,
+                param_env,
+                SuspendCheckData {
+                    descr_pre,
+                    plural_len: len.try_eval_usize(tcx, param_env).unwrap_or(0) as usize + 1,
+                    ..data
+                },
+            )
+        }
+        // If drop tracking is enabled, we want to look through references, since the referrent
+        // may not be considered live across the await point.
+        ty::Ref(_region, ty, _mutability) => {
+            let descr_pre = &format!("{}reference{} to ", data.descr_pre, plural_suffix);
+            check_must_not_suspend_ty(
+                tcx,
+                ty,
+                hir_id,
+                param_env,
+                SuspendCheckData { descr_pre, ..data },
+            )
+        }
+        _ => false,
+    }
+}
+
+fn check_must_not_suspend_def(
+    tcx: TyCtxt<'_>,
+    def_id: DefId,
+    hir_id: hir::HirId,
+    data: SuspendCheckData<'_>,
+) -> bool {
+    if let Some(attr) = tcx.get_attr(def_id, sym::must_not_suspend) {
+        let msg = format!(
+            "{}`{}`{} held across a suspend point, but should not be",
+            data.descr_pre,
+            tcx.def_path_str(def_id),
+            data.descr_post,
+        );
+        tcx.struct_span_lint_hir(
+            rustc_session::lint::builtin::MUST_NOT_SUSPEND,
+            hir_id,
+            data.source_span,
+            msg,
+            |lint| {
+                // add span pointing to the offending yield/await
+                lint.span_label(data.yield_span, "the value is held across this suspend point");
+
+                // Add optional reason note
+                if let Some(note) = attr.value_str() {
+                    // FIXME(guswynn): consider formatting this better
+                    lint.span_note(data.source_span, note.as_str());
+                }
+
+                // Add some quick suggestions on what to do
+                // FIXME: can `drop` work as a suggestion here as well?
+                lint.span_help(
+                    data.source_span,
+                    "consider using a block (`{ ... }`) \
+                    to shrink the value's scope, ending before the suspend point",
+                )
+            },
+        );
+
+        true
+    } else {
+        false
+    }
+}
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index 28c9080d38d..84640b703c8 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -331,7 +331,7 @@ impl<'tcx> Inliner<'tcx> {
                     return None;
                 }
 
-                let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, substs);
+                let fn_sig = self.tcx.fn_sig(def_id).subst(self.tcx, substs);
                 let source_info = SourceInfo { span: fn_span, ..terminator.source_info };
 
                 return Some(CallSite { callee, fn_sig, block: bb, target, source_info });
@@ -947,12 +947,12 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
                             return;
                         };
 
-                        let Some(&f_ty) = layout.field_tys.get(local) else {
+                        let Some(f_ty) = layout.field_tys.get(local) else {
                             self.validation = Err("malformed MIR");
                             return;
                         };
 
-                        f_ty
+                        f_ty.ty
                     } else {
                         let Some(f_ty) = substs.as_generator().prefix_tys().nth(f.index()) else {
                             self.validation = Err("malformed MIR");
diff --git a/compiler/rustc_mir_transform/src/instcombine.rs b/compiler/rustc_mir_transform/src/instcombine.rs
index 2f3c65869ef..e1faa7a08d9 100644
--- a/compiler/rustc_mir_transform/src/instcombine.rs
+++ b/compiler/rustc_mir_transform/src/instcombine.rs
@@ -6,7 +6,8 @@ use rustc_middle::mir::{
     BinOp, Body, Constant, ConstantKind, LocalDecls, Operand, Place, ProjectionElem, Rvalue,
     SourceInfo, Statement, StatementKind, Terminator, TerminatorKind, UnOp,
 };
-use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty::{self, layout::TyAndLayout, ParamEnv, ParamEnvAnd, SubstsRef, Ty, TyCtxt};
+use rustc_span::symbol::{sym, Symbol};
 
 pub struct InstCombine;
 
@@ -16,7 +17,11 @@ impl<'tcx> MirPass<'tcx> for InstCombine {
     }
 
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        let ctx = InstCombineContext { tcx, local_decls: &body.local_decls };
+        let ctx = InstCombineContext {
+            tcx,
+            local_decls: &body.local_decls,
+            param_env: tcx.param_env_reveal_all_normalized(body.source.def_id()),
+        };
         for block in body.basic_blocks.as_mut() {
             for statement in block.statements.iter_mut() {
                 match statement.kind {
@@ -33,6 +38,10 @@ impl<'tcx> MirPass<'tcx> for InstCombine {
                 &mut block.terminator.as_mut().unwrap(),
                 &mut block.statements,
             );
+            ctx.combine_intrinsic_assert(
+                &mut block.terminator.as_mut().unwrap(),
+                &mut block.statements,
+            );
         }
     }
 }
@@ -40,6 +49,7 @@ impl<'tcx> MirPass<'tcx> for InstCombine {
 struct InstCombineContext<'tcx, 'a> {
     tcx: TyCtxt<'tcx>,
     local_decls: &'a LocalDecls<'tcx>,
+    param_env: ParamEnv<'tcx>,
 }
 
 impl<'tcx> InstCombineContext<'tcx, '_> {
@@ -200,4 +210,76 @@ impl<'tcx> InstCombineContext<'tcx, '_> {
         });
         terminator.kind = TerminatorKind::Goto { target: destination_block };
     }
+
+    fn combine_intrinsic_assert(
+        &self,
+        terminator: &mut Terminator<'tcx>,
+        _statements: &mut Vec<Statement<'tcx>>,
+    ) {
+        let TerminatorKind::Call { func, target, .. } = &mut terminator.kind  else { return; };
+        let Some(target_block) = target else { return; };
+        let func_ty = func.ty(self.local_decls, self.tcx);
+        let Some((intrinsic_name, substs)) = resolve_rust_intrinsic(self.tcx, func_ty) else {
+            return;
+        };
+        // The intrinsics we are interested in have one generic parameter
+        if substs.is_empty() {
+            return;
+        }
+        let ty = substs.type_at(0);
+
+        // Check this is a foldable intrinsic before we query the layout of our generic parameter
+        let Some(assert_panics) = intrinsic_assert_panics(intrinsic_name) else { return; };
+        let Ok(layout) = self.tcx.layout_of(self.param_env.and(ty)) else { return; };
+        if assert_panics(self.tcx, self.param_env.and(layout)) {
+            // If we know the assert panics, indicate to later opts that the call diverges
+            *target = None;
+        } else {
+            // If we know the assert does not panic, turn the call into a Goto
+            terminator.kind = TerminatorKind::Goto { target: *target_block };
+        }
+    }
+}
+
+fn intrinsic_assert_panics<'tcx>(
+    intrinsic_name: Symbol,
+) -> Option<fn(TyCtxt<'tcx>, ParamEnvAnd<'tcx, TyAndLayout<'tcx>>) -> bool> {
+    fn inhabited_predicate<'tcx>(
+        _tcx: TyCtxt<'tcx>,
+        param_env_and_layout: ParamEnvAnd<'tcx, TyAndLayout<'tcx>>,
+    ) -> bool {
+        let (_param_env, layout) = param_env_and_layout.into_parts();
+        layout.abi.is_uninhabited()
+    }
+    fn zero_valid_predicate<'tcx>(
+        tcx: TyCtxt<'tcx>,
+        param_env_and_layout: ParamEnvAnd<'tcx, TyAndLayout<'tcx>>,
+    ) -> bool {
+        !tcx.permits_zero_init(param_env_and_layout)
+    }
+    fn mem_uninitialized_valid_predicate<'tcx>(
+        tcx: TyCtxt<'tcx>,
+        param_env_and_layout: ParamEnvAnd<'tcx, TyAndLayout<'tcx>>,
+    ) -> bool {
+        !tcx.permits_uninit_init(param_env_and_layout)
+    }
+
+    match intrinsic_name {
+        sym::assert_inhabited => Some(inhabited_predicate),
+        sym::assert_zero_valid => Some(zero_valid_predicate),
+        sym::assert_mem_uninitialized_valid => Some(mem_uninitialized_valid_predicate),
+        _ => None,
+    }
+}
+
+fn resolve_rust_intrinsic<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    func_ty: Ty<'tcx>,
+) -> Option<(Symbol, SubstsRef<'tcx>)> {
+    if let ty::FnDef(def_id, substs) = *func_ty.kind() {
+        if tcx.is_intrinsic(def_id) {
+            return Some((tcx.item_name(def_id), substs));
+        }
+    }
+    None
 }
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 20b7fdcfe6d..cbebca15483 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -54,7 +54,9 @@ mod const_debuginfo;
 mod const_goto;
 mod const_prop;
 mod const_prop_lint;
+mod copy_prop;
 mod coverage;
+mod ctfe_limit;
 mod dataflow_const_prop;
 mod dead_store_elimination;
 mod deaggregator;
@@ -86,11 +88,11 @@ mod required_consts;
 mod reveal_all;
 mod separate_const_switch;
 mod shim;
+mod ssa;
 // This pass is public to allow external drivers to perform MIR cleanup
 pub mod simplify;
 mod simplify_branches;
 mod simplify_comparison_integral;
-mod simplify_try;
 mod sroa;
 mod uninhabited_enum_branching;
 mod unreachable_prop;
@@ -102,7 +104,6 @@ use rustc_mir_dataflow::rustc_peek;
 
 pub fn provide(providers: &mut Providers) {
     check_unsafety::provide(providers);
-    check_packed_ref::provide(providers);
     coverage::query::provide(providers);
     ffi_unwind_calls::provide(providers);
     shim::provide(providers);
@@ -124,6 +125,7 @@ pub fn provide(providers: &mut Providers) {
         mir_drops_elaborated_and_const_checked,
         mir_for_ctfe,
         mir_for_ctfe_of_const_arg,
+        mir_generator_witnesses: generator::mir_generator_witnesses,
         optimized_mir,
         is_mir_available,
         is_ctfe_mir_available: |tcx, did| is_mir_available(tcx, did),
@@ -410,6 +412,8 @@ fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -
         }
     }
 
+    pm::run_passes(tcx, &mut body, &[&ctfe_limit::CtfeLimit], None);
+
     debug_assert!(!body.has_free_regions(), "Free regions in MIR for CTFE");
 
     body
@@ -426,6 +430,9 @@ fn mir_drops_elaborated_and_const_checked(
         return tcx.mir_drops_elaborated_and_const_checked(def);
     }
 
+    if tcx.generator_kind(def.did).is_some() && tcx.sess.opts.unstable_opts.drop_tracking_mir {
+        tcx.ensure().mir_generator_witnesses(def.did);
+    }
     let mir_borrowck = tcx.mir_borrowck_opt_const_arg(def);
 
     let is_fn_like = tcx.def_kind(def.did).is_fn_like();
@@ -541,13 +548,13 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         &[
             &reveal_all::RevealAll, // has to be done before inlining, since inlined code is in RevealAll mode.
             &lower_slice_len::LowerSliceLenCalls, // has to be done before inlining, otherwise actual call will be almost always inlined. Also simple, so can just do first
-            &normalize_array_len::NormalizeArrayLen, // has to run after `slice::len` lowering
             &unreachable_prop::UnreachablePropagation,
             &uninhabited_enum_branching::UninhabitedEnumBranching,
             &o1(simplify::SimplifyCfg::new("after-uninhabited-enum-branching")),
             &inline::Inline,
             &remove_storage_markers::RemoveStorageMarkers,
             &remove_zsts::RemoveZsts,
+            &normalize_array_len::NormalizeArrayLen, // has to run after `slice::len` lowering
             &const_goto::ConstGoto,
             &remove_unneeded_drops::RemoveUnneededDrops,
             &sroa::ScalarReplacementOfAggregates,
@@ -557,6 +564,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &instcombine::InstCombine,
             &separate_const_switch::SeparateConstSwitch,
             &simplify::SimplifyLocals::new("before-const-prop"),
+            &copy_prop::CopyProp,
             //
             // FIXME(#70073): This pass is responsible for both optimization as well as some lints.
             &const_prop::ConstProp,
@@ -567,8 +575,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &o1(simplify_branches::SimplifyConstCondition::new("after-const-prop")),
             &early_otherwise_branch::EarlyOtherwiseBranch,
             &simplify_comparison_integral::SimplifyComparisonIntegral,
-            &simplify_try::SimplifyArmIdentity,
-            &simplify_try::SimplifyBranchSame,
             &dead_store_elimination::DeadStoreElimination,
             &dest_prop::DestinationPropagation,
             &o1(simplify_branches::SimplifyConstCondition::new("final")),
diff --git a/compiler/rustc_mir_transform/src/normalize_array_len.rs b/compiler/rustc_mir_transform/src/normalize_array_len.rs
index 1708b287e56..b36c8a0bd53 100644
--- a/compiler/rustc_mir_transform/src/normalize_array_len.rs
+++ b/compiler/rustc_mir_transform/src/normalize_array_len.rs
@@ -1,288 +1,104 @@
 //! This pass eliminates casting of arrays into slices when their length
 //! is taken using `.len()` method. Handy to preserve information in MIR for const prop
 
+use crate::ssa::SsaLocals;
 use crate::MirPass;
-use rustc_data_structures::fx::FxIndexMap;
-use rustc_data_structures::intern::Interned;
-use rustc_index::bit_set::BitSet;
 use rustc_index::vec::IndexVec;
+use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
-use rustc_middle::ty::{self, ReErased, Region, TyCtxt};
-
-const MAX_NUM_BLOCKS: usize = 800;
-const MAX_NUM_LOCALS: usize = 3000;
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_mir_dataflow::impls::borrowed_locals;
 
 pub struct NormalizeArrayLen;
 
 impl<'tcx> MirPass<'tcx> for NormalizeArrayLen {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        // See #105929
-        sess.mir_opt_level() >= 4 && sess.opts.unstable_opts.unsound_mir_opts
+        sess.mir_opt_level() >= 3
     }
 
+    #[instrument(level = "trace", skip(self, tcx, body))]
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        // early returns for edge cases of highly unrolled functions
-        if body.basic_blocks.len() > MAX_NUM_BLOCKS {
-            return;
-        }
-        if body.local_decls.len() > MAX_NUM_LOCALS {
-            return;
-        }
+        debug!(def_id = ?body.source.def_id());
         normalize_array_len_calls(tcx, body)
     }
 }
 
-pub fn normalize_array_len_calls<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-    // We don't ever touch terminators, so no need to invalidate the CFG cache
-    let basic_blocks = body.basic_blocks.as_mut_preserves_cfg();
-    let local_decls = &mut body.local_decls;
+fn normalize_array_len_calls<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
+    let borrowed_locals = borrowed_locals(body);
+    let ssa = SsaLocals::new(tcx, param_env, body, &borrowed_locals);
 
-    // do a preliminary analysis to see if we ever have locals of type `[T;N]` or `&[T;N]`
-    let mut interesting_locals = BitSet::new_empty(local_decls.len());
-    for (local, decl) in local_decls.iter_enumerated() {
-        match decl.ty.kind() {
-            ty::Array(..) => {
-                interesting_locals.insert(local);
-            }
-            ty::Ref(.., ty, Mutability::Not) => match ty.kind() {
-                ty::Array(..) => {
-                    interesting_locals.insert(local);
-                }
-                _ => {}
-            },
-            _ => {}
-        }
-    }
-    if interesting_locals.is_empty() {
-        // we have found nothing to analyze
-        return;
-    }
-    let num_intesting_locals = interesting_locals.count();
-    let mut state = FxIndexMap::with_capacity_and_hasher(num_intesting_locals, Default::default());
-    let mut patches_scratchpad =
-        FxIndexMap::with_capacity_and_hasher(num_intesting_locals, Default::default());
-    let mut replacements_scratchpad =
-        FxIndexMap::with_capacity_and_hasher(num_intesting_locals, Default::default());
-    for block in basic_blocks {
-        // make length calls for arrays [T; N] not to decay into length calls for &[T]
-        // that forbids constant propagation
-        normalize_array_len_call(
-            tcx,
-            block,
-            local_decls,
-            &interesting_locals,
-            &mut state,
-            &mut patches_scratchpad,
-            &mut replacements_scratchpad,
-        );
-        state.clear();
-        patches_scratchpad.clear();
-        replacements_scratchpad.clear();
-    }
-}
+    let slice_lengths = compute_slice_length(tcx, &ssa, body);
+    debug!(?slice_lengths);
 
-struct Patcher<'a, 'tcx> {
-    tcx: TyCtxt<'tcx>,
-    patches_scratchpad: &'a FxIndexMap<usize, usize>,
-    replacements_scratchpad: &'a mut FxIndexMap<usize, Local>,
-    local_decls: &'a mut IndexVec<Local, LocalDecl<'tcx>>,
-    statement_idx: usize,
+    Replacer { tcx, slice_lengths }.visit_body_preserves_cfg(body);
 }
 
-impl<'tcx> Patcher<'_, 'tcx> {
-    fn patch_expand_statement(
-        &mut self,
-        statement: &mut Statement<'tcx>,
-    ) -> Option<std::vec::IntoIter<Statement<'tcx>>> {
-        let idx = self.statement_idx;
-        if let Some(len_statemnt_idx) = self.patches_scratchpad.get(&idx).copied() {
-            let mut statements = Vec::with_capacity(2);
-
-            // we are at statement that performs a cast. The only sound way is
-            // to create another local that performs a similar copy without a cast and then
-            // use this copy in the Len operation
-
-            match &statement.kind {
-                StatementKind::Assign(box (
-                    ..,
-                    Rvalue::Cast(
-                        CastKind::Pointer(ty::adjustment::PointerCast::Unsize),
-                        operand,
-                        _,
-                    ),
-                )) => {
-                    match operand {
-                        Operand::Copy(place) | Operand::Move(place) => {
-                            // create new local
-                            let ty = operand.ty(self.local_decls, self.tcx);
-                            let local_decl = LocalDecl::with_source_info(ty, statement.source_info);
-                            let local = self.local_decls.push(local_decl);
-                            // make it live
-                            let mut make_live_statement = statement.clone();
-                            make_live_statement.kind = StatementKind::StorageLive(local);
-                            statements.push(make_live_statement);
-                            // copy into it
-
-                            let operand = Operand::Copy(*place);
-                            let mut make_copy_statement = statement.clone();
-                            let assign_to = Place::from(local);
-                            let rvalue = Rvalue::Use(operand);
-                            make_copy_statement.kind =
-                                StatementKind::Assign(Box::new((assign_to, rvalue)));
-                            statements.push(make_copy_statement);
-
-                            // to reorder we have to copy and make NOP
-                            statements.push(statement.clone());
-                            statement.make_nop();
-
-                            self.replacements_scratchpad.insert(len_statemnt_idx, local);
-                        }
-                        _ => {
-                            unreachable!("it's a bug in the implementation")
-                        }
-                    }
-                }
-                _ => {
-                    unreachable!("it's a bug in the implementation")
+fn compute_slice_length<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ssa: &SsaLocals,
+    body: &Body<'tcx>,
+) -> IndexVec<Local, Option<ty::Const<'tcx>>> {
+    let mut slice_lengths = IndexVec::from_elem(None, &body.local_decls);
+
+    for (local, rvalue) in ssa.assignments(body) {
+        match rvalue {
+            Rvalue::Cast(
+                CastKind::Pointer(ty::adjustment::PointerCast::Unsize),
+                operand,
+                cast_ty,
+            ) => {
+                let operand_ty = operand.ty(body, tcx);
+                debug!(?operand_ty);
+                if let Some(operand_ty) = operand_ty.builtin_deref(true)
+                    && let ty::Array(_, len) = operand_ty.ty.kind()
+                    && let Some(cast_ty) = cast_ty.builtin_deref(true)
+                    && let ty::Slice(..) = cast_ty.ty.kind()
+                {
+                    slice_lengths[local] = Some(*len);
                 }
             }
-
-            self.statement_idx += 1;
-
-            Some(statements.into_iter())
-        } else if let Some(local) = self.replacements_scratchpad.get(&idx).copied() {
-            let mut statements = Vec::with_capacity(2);
-
-            match &statement.kind {
-                StatementKind::Assign(box (into, Rvalue::Len(place))) => {
-                    let add_deref = if let Some(..) = place.as_local() {
-                        false
-                    } else if let Some(..) = place.local_or_deref_local() {
-                        true
-                    } else {
-                        unreachable!("it's a bug in the implementation")
-                    };
-                    // replace len statement
-                    let mut len_statement = statement.clone();
-                    let mut place = Place::from(local);
-                    if add_deref {
-                        place = self.tcx.mk_place_deref(place);
-                    }
-                    len_statement.kind =
-                        StatementKind::Assign(Box::new((*into, Rvalue::Len(place))));
-                    statements.push(len_statement);
-
-                    // make temporary dead
-                    let mut make_dead_statement = statement.clone();
-                    make_dead_statement.kind = StatementKind::StorageDead(local);
-                    statements.push(make_dead_statement);
-
-                    // make original statement NOP
-                    statement.make_nop();
+            // The length information is stored in the fat pointer, so we treat `operand` as a value.
+            Rvalue::Use(operand) => {
+                if let Some(rhs) = operand.place() && let Some(rhs) = rhs.as_local() {
+                    slice_lengths[local] = slice_lengths[rhs];
                 }
-                _ => {
-                    unreachable!("it's a bug in the implementation")
+            }
+            // The length information is stored in the fat pointer.
+            // Reborrowing copies length information from one pointer to the other.
+            Rvalue::Ref(_, _, rhs) | Rvalue::AddressOf(_, rhs) => {
+                if let [PlaceElem::Deref] = rhs.projection[..] {
+                    slice_lengths[local] = slice_lengths[rhs.local];
                 }
             }
-
-            self.statement_idx += 1;
-
-            Some(statements.into_iter())
-        } else {
-            self.statement_idx += 1;
-            None
+            _ => {}
         }
     }
+
+    slice_lengths
 }
 
-fn normalize_array_len_call<'tcx>(
+struct Replacer<'tcx> {
     tcx: TyCtxt<'tcx>,
-    block: &mut BasicBlockData<'tcx>,
-    local_decls: &mut IndexVec<Local, LocalDecl<'tcx>>,
-    interesting_locals: &BitSet<Local>,
-    state: &mut FxIndexMap<Local, usize>,
-    patches_scratchpad: &mut FxIndexMap<usize, usize>,
-    replacements_scratchpad: &mut FxIndexMap<usize, Local>,
-) {
-    for (statement_idx, statement) in block.statements.iter_mut().enumerate() {
-        match &mut statement.kind {
-            StatementKind::Assign(box (place, rvalue)) => {
-                match rvalue {
-                    Rvalue::Cast(
-                        CastKind::Pointer(ty::adjustment::PointerCast::Unsize),
-                        operand,
-                        cast_ty,
-                    ) => {
-                        let Some(local) = place.as_local() else { return };
-                        match operand {
-                            Operand::Copy(place) | Operand::Move(place) => {
-                                let Some(operand_local) = place.local_or_deref_local() else { return; };
-                                if !interesting_locals.contains(operand_local) {
-                                    return;
-                                }
-                                let operand_ty = local_decls[operand_local].ty;
-                                match (operand_ty.kind(), cast_ty.kind()) {
-                                    (ty::Array(of_ty_src, ..), ty::Slice(of_ty_dst)) => {
-                                        if of_ty_src == of_ty_dst {
-                                            // this is a cast from [T; N] into [T], so we are good
-                                            state.insert(local, statement_idx);
-                                        }
-                                    }
-                                    // current way of patching doesn't allow to work with `mut`
-                                    (
-                                        ty::Ref(
-                                            Region(Interned(ReErased, _)),
-                                            operand_ty,
-                                            Mutability::Not,
-                                        ),
-                                        ty::Ref(
-                                            Region(Interned(ReErased, _)),
-                                            cast_ty,
-                                            Mutability::Not,
-                                        ),
-                                    ) => {
-                                        match (operand_ty.kind(), cast_ty.kind()) {
-                                            // current way of patching doesn't allow to work with `mut`
-                                            (ty::Array(of_ty_src, ..), ty::Slice(of_ty_dst)) => {
-                                                if of_ty_src == of_ty_dst {
-                                                    // this is a cast from [T; N] into [T], so we are good
-                                                    state.insert(local, statement_idx);
-                                                }
-                                            }
-                                            _ => {}
-                                        }
-                                    }
-                                    _ => {}
-                                }
-                            }
-                            _ => {}
-                        }
-                    }
-                    Rvalue::Len(place) => {
-                        let Some(local) = place.local_or_deref_local() else {
-                            return;
-                        };
-                        if let Some(cast_statement_idx) = state.get(&local).copied() {
-                            patches_scratchpad.insert(cast_statement_idx, statement_idx);
-                        }
-                    }
-                    _ => {
-                        // invalidate
-                        state.remove(&place.local);
-                    }
-                }
-            }
-            _ => {}
-        }
-    }
+    slice_lengths: IndexVec<Local, Option<ty::Const<'tcx>>>,
+}
 
-    let mut patcher = Patcher {
-        tcx,
-        patches_scratchpad: &*patches_scratchpad,
-        replacements_scratchpad,
-        local_decls,
-        statement_idx: 0,
-    };
+impl<'tcx> MutVisitor<'tcx> for Replacer<'tcx> {
+    fn tcx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
 
-    block.expand_statements(|st| patcher.patch_expand_statement(st));
+    fn visit_rvalue(&mut self, rvalue: &mut Rvalue<'tcx>, loc: Location) {
+        if let Rvalue::Len(place) = rvalue
+            && let [PlaceElem::Deref] = &place.projection[..]
+            && let Some(len) = self.slice_lengths[place.local]
+        {
+            *rvalue = Rvalue::Use(Operand::Constant(Box::new(Constant {
+                span: rustc_span::DUMMY_SP,
+                user_ty: None,
+                literal: ConstantKind::from_const(len, self.tcx),
+            })));
+        }
+        self.super_rvalue(rvalue, loc);
+    }
 }
diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
index f1bbf2ea7e8..e3a03aa08af 100644
--- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
+++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
@@ -35,6 +35,7 @@ impl RemoveNoopLandingPads {
                 | StatementKind::StorageDead(_)
                 | StatementKind::AscribeUserType(..)
                 | StatementKind::Coverage(..)
+                | StatementKind::ConstEvalCounter
                 | StatementKind::Nop => {
                     // These are all noops in a landing pad
                 }
diff --git a/compiler/rustc_mir_transform/src/separate_const_switch.rs b/compiler/rustc_mir_transform/src/separate_const_switch.rs
index 2f116aaa958..a24d2d34d79 100644
--- a/compiler/rustc_mir_transform/src/separate_const_switch.rs
+++ b/compiler/rustc_mir_transform/src/separate_const_switch.rs
@@ -250,6 +250,7 @@ fn is_likely_const<'tcx>(mut tracked_place: Place<'tcx>, block: &BasicBlockData<
             | StatementKind::Coverage(_)
             | StatementKind::StorageDead(_)
             | StatementKind::Intrinsic(_)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
         }
     }
@@ -318,6 +319,7 @@ fn find_determining_place<'tcx>(
             | StatementKind::AscribeUserType(_, _)
             | StatementKind::Coverage(_)
             | StatementKind::Intrinsic(_)
+            | StatementKind::ConstEvalCounter
             | StatementKind::Nop => {}
 
             // If the discriminant is set, it is always set
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index dace540fa29..8d4fe74e7d3 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -152,7 +152,7 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>)
     } else {
         InternalSubsts::identity_for_item(tcx, def_id)
     };
-    let sig = tcx.bound_fn_sig(def_id).subst(tcx, substs);
+    let sig = tcx.fn_sig(def_id).subst(tcx, substs);
     let sig = tcx.erase_late_bound_regions(sig);
     let span = tcx.def_span(def_id);
 
@@ -363,7 +363,7 @@ impl<'tcx> CloneShimBuilder<'tcx> {
         // we must subst the self_ty because it's
         // otherwise going to be TySelf and we can't index
         // or access fields of a Place of type TySelf.
-        let sig = tcx.bound_fn_sig(def_id).subst(tcx, &[self_ty.into()]);
+        let sig = tcx.fn_sig(def_id).subst(tcx, &[self_ty.into()]);
         let sig = tcx.erase_late_bound_regions(sig);
         let span = tcx.def_span(def_id);
 
@@ -606,7 +606,7 @@ fn build_call_shim<'tcx>(
     };
 
     let def_id = instance.def_id();
-    let sig = tcx.bound_fn_sig(def_id);
+    let sig = tcx.fn_sig(def_id);
     let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig));
 
     assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body());
@@ -798,7 +798,11 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
     let param_env = tcx.param_env(ctor_id);
 
     // Normalize the sig.
-    let sig = tcx.fn_sig(ctor_id).no_bound_vars().expect("LBR in ADT constructor signature");
+    let sig = tcx
+        .fn_sig(ctor_id)
+        .subst_identity()
+        .no_bound_vars()
+        .expect("LBR in ADT constructor signature");
     let sig = tcx.normalize_erasing_regions(param_env, sig);
 
     let ty::Adt(adt_def, substs) = sig.output().kind() else {
diff --git a/compiler/rustc_mir_transform/src/simplify.rs b/compiler/rustc_mir_transform/src/simplify.rs
index 8f6abe7a912..ced97b2c788 100644
--- a/compiler/rustc_mir_transform/src/simplify.rs
+++ b/compiler/rustc_mir_transform/src/simplify.rs
@@ -404,6 +404,18 @@ impl<'tcx> MirPass<'tcx> for SimplifyLocals {
     }
 }
 
+pub fn remove_unused_definitions<'tcx>(body: &mut Body<'tcx>) {
+    // First, we're going to get a count of *actual* uses for every `Local`.
+    let mut used_locals = UsedLocals::new(body);
+
+    // Next, we're going to remove any `Local` with zero actual uses. When we remove those
+    // `Locals`, we're also going to subtract any uses of other `Locals` from the `used_locals`
+    // count. For example, if we removed `_2 = discriminant(_1)`, then we'll subtract one from
+    // `use_counts[_1]`. That in turn might make `_1` unused, so we loop until we hit a
+    // fixedpoint where there are no more unused locals.
+    remove_unused_definitions_helper(&mut used_locals, body);
+}
+
 pub fn simplify_locals<'tcx>(body: &mut Body<'tcx>, tcx: TyCtxt<'tcx>) {
     // First, we're going to get a count of *actual* uses for every `Local`.
     let mut used_locals = UsedLocals::new(body);
@@ -413,7 +425,7 @@ pub fn simplify_locals<'tcx>(body: &mut Body<'tcx>, tcx: TyCtxt<'tcx>) {
     // count. For example, if we removed `_2 = discriminant(_1)`, then we'll subtract one from
     // `use_counts[_1]`. That in turn might make `_1` unused, so we loop until we hit a
     // fixedpoint where there are no more unused locals.
-    remove_unused_definitions(&mut used_locals, body);
+    remove_unused_definitions_helper(&mut used_locals, body);
 
     // Finally, we'll actually do the work of shrinking `body.local_decls` and remapping the `Local`s.
     let map = make_local_map(&mut body.local_decls, &used_locals);
@@ -517,7 +529,7 @@ impl<'tcx> Visitor<'tcx> for UsedLocals {
                 self.super_statement(statement, location);
             }
 
-            StatementKind::Nop => {}
+            StatementKind::ConstEvalCounter | StatementKind::Nop => {}
 
             StatementKind::StorageLive(_local) | StatementKind::StorageDead(_local) => {}
 
@@ -548,7 +560,7 @@ impl<'tcx> Visitor<'tcx> for UsedLocals {
 }
 
 /// Removes unused definitions. Updates the used locals to reflect the changes made.
-fn remove_unused_definitions(used_locals: &mut UsedLocals, body: &mut Body<'_>) {
+fn remove_unused_definitions_helper(used_locals: &mut UsedLocals, body: &mut Body<'_>) {
     // The use counts are updated as we remove the statements. A local might become unused
     // during the retain operation, leading to a temporary inconsistency (storage statements or
     // definitions referencing the local might remain). For correctness it is crucial that this
diff --git a/compiler/rustc_mir_transform/src/simplify_try.rs b/compiler/rustc_mir_transform/src/simplify_try.rs
deleted file mode 100644
index e4f3ace9a93..00000000000
--- a/compiler/rustc_mir_transform/src/simplify_try.rs
+++ /dev/null
@@ -1,822 +0,0 @@
-//! The general point of the optimizations provided here is to simplify something like:
-//!
-//! ```rust
-//! # fn foo<T, E>(x: Result<T, E>) -> Result<T, E> {
-//! match x {
-//!     Ok(x) => Ok(x),
-//!     Err(x) => Err(x)
-//! }
-//! # }
-//! ```
-//!
-//! into just `x`.
-
-use crate::{simplify, MirPass};
-use itertools::Itertools as _;
-use rustc_index::{bit_set::BitSet, vec::IndexVec};
-use rustc_middle::mir::visit::{NonUseContext, PlaceContext, Visitor};
-use rustc_middle::mir::*;
-use rustc_middle::ty::{self, List, Ty, TyCtxt};
-use rustc_target::abi::VariantIdx;
-use std::iter::{once, Enumerate, Peekable};
-use std::slice::Iter;
-
-/// Simplifies arms of form `Variant(x) => Variant(x)` to just a move.
-///
-/// This is done by transforming basic blocks where the statements match:
-///
-/// ```ignore (MIR)
-/// _LOCAL_TMP = ((_LOCAL_1 as Variant ).FIELD: TY );
-/// _TMP_2 = _LOCAL_TMP;
-/// ((_LOCAL_0 as Variant).FIELD: TY) = move _TMP_2;
-/// discriminant(_LOCAL_0) = VAR_IDX;
-/// ```
-///
-/// into:
-///
-/// ```ignore (MIR)
-/// _LOCAL_0 = move _LOCAL_1
-/// ```
-pub struct SimplifyArmIdentity;
-
-#[derive(Debug)]
-struct ArmIdentityInfo<'tcx> {
-    /// Storage location for the variant's field
-    local_temp_0: Local,
-    /// Storage location holding the variant being read from
-    local_1: Local,
-    /// The variant field being read from
-    vf_s0: VarField<'tcx>,
-    /// Index of the statement which loads the variant being read
-    get_variant_field_stmt: usize,
-
-    /// Tracks each assignment to a temporary of the variant's field
-    field_tmp_assignments: Vec<(Local, Local)>,
-
-    /// Storage location holding the variant's field that was read from
-    local_tmp_s1: Local,
-    /// Storage location holding the enum that we are writing to
-    local_0: Local,
-    /// The variant field being written to
-    vf_s1: VarField<'tcx>,
-
-    /// Storage location that the discriminant is being written to
-    set_discr_local: Local,
-    /// The variant being written
-    set_discr_var_idx: VariantIdx,
-
-    /// Index of the statement that should be overwritten as a move
-    stmt_to_overwrite: usize,
-    /// SourceInfo for the new move
-    source_info: SourceInfo,
-
-    /// Indices of matching Storage{Live,Dead} statements encountered.
-    /// (StorageLive index,, StorageDead index, Local)
-    storage_stmts: Vec<(usize, usize, Local)>,
-
-    /// The statements that should be removed (turned into nops)
-    stmts_to_remove: Vec<usize>,
-
-    /// Indices of debug variables that need to be adjusted to point to
-    // `{local_0}.{dbg_projection}`.
-    dbg_info_to_adjust: Vec<usize>,
-
-    /// The projection used to rewrite debug info.
-    dbg_projection: &'tcx List<PlaceElem<'tcx>>,
-}
-
-fn get_arm_identity_info<'a, 'tcx>(
-    stmts: &'a [Statement<'tcx>],
-    locals_count: usize,
-    debug_info: &'a [VarDebugInfo<'tcx>],
-) -> Option<ArmIdentityInfo<'tcx>> {
-    // This can't possibly match unless there are at least 3 statements in the block
-    // so fail fast on tiny blocks.
-    if stmts.len() < 3 {
-        return None;
-    }
-
-    let mut tmp_assigns = Vec::new();
-    let mut nop_stmts = Vec::new();
-    let mut storage_stmts = Vec::new();
-    let mut storage_live_stmts = Vec::new();
-    let mut storage_dead_stmts = Vec::new();
-
-    type StmtIter<'a, 'tcx> = Peekable<Enumerate<Iter<'a, Statement<'tcx>>>>;
-
-    fn is_storage_stmt(stmt: &Statement<'_>) -> bool {
-        matches!(stmt.kind, StatementKind::StorageLive(_) | StatementKind::StorageDead(_))
-    }
-
-    /// Eats consecutive Statements which match `test`, performing the specified `action` for each.
-    /// The iterator `stmt_iter` is not advanced if none were matched.
-    fn try_eat<'a, 'tcx>(
-        stmt_iter: &mut StmtIter<'a, 'tcx>,
-        test: impl Fn(&'a Statement<'tcx>) -> bool,
-        mut action: impl FnMut(usize, &'a Statement<'tcx>),
-    ) {
-        while stmt_iter.peek().map_or(false, |(_, stmt)| test(stmt)) {
-            let (idx, stmt) = stmt_iter.next().unwrap();
-
-            action(idx, stmt);
-        }
-    }
-
-    /// Eats consecutive `StorageLive` and `StorageDead` Statements.
-    /// The iterator `stmt_iter` is not advanced if none were found.
-    fn try_eat_storage_stmts(
-        stmt_iter: &mut StmtIter<'_, '_>,
-        storage_live_stmts: &mut Vec<(usize, Local)>,
-        storage_dead_stmts: &mut Vec<(usize, Local)>,
-    ) {
-        try_eat(stmt_iter, is_storage_stmt, |idx, stmt| {
-            if let StatementKind::StorageLive(l) = stmt.kind {
-                storage_live_stmts.push((idx, l));
-            } else if let StatementKind::StorageDead(l) = stmt.kind {
-                storage_dead_stmts.push((idx, l));
-            }
-        })
-    }
-
-    fn is_tmp_storage_stmt(stmt: &Statement<'_>) -> bool {
-        use rustc_middle::mir::StatementKind::Assign;
-        if let Assign(box (place, Rvalue::Use(Operand::Copy(p) | Operand::Move(p)))) = &stmt.kind {
-            place.as_local().is_some() && p.as_local().is_some()
-        } else {
-            false
-        }
-    }
-
-    /// Eats consecutive `Assign` Statements.
-    // The iterator `stmt_iter` is not advanced if none were found.
-    fn try_eat_assign_tmp_stmts(
-        stmt_iter: &mut StmtIter<'_, '_>,
-        tmp_assigns: &mut Vec<(Local, Local)>,
-        nop_stmts: &mut Vec<usize>,
-    ) {
-        try_eat(stmt_iter, is_tmp_storage_stmt, |idx, stmt| {
-            use rustc_middle::mir::StatementKind::Assign;
-            if let Assign(box (place, Rvalue::Use(Operand::Copy(p) | Operand::Move(p)))) =
-                &stmt.kind
-            {
-                tmp_assigns.push((place.as_local().unwrap(), p.as_local().unwrap()));
-                nop_stmts.push(idx);
-            }
-        })
-    }
-
-    fn find_storage_live_dead_stmts_for_local(
-        local: Local,
-        stmts: &[Statement<'_>],
-    ) -> Option<(usize, usize)> {
-        trace!("looking for {:?}", local);
-        let mut storage_live_stmt = None;
-        let mut storage_dead_stmt = None;
-        for (idx, stmt) in stmts.iter().enumerate() {
-            if stmt.kind == StatementKind::StorageLive(local) {
-                storage_live_stmt = Some(idx);
-            } else if stmt.kind == StatementKind::StorageDead(local) {
-                storage_dead_stmt = Some(idx);
-            }
-        }
-
-        Some((storage_live_stmt?, storage_dead_stmt.unwrap_or(usize::MAX)))
-    }
-
-    // Try to match the expected MIR structure with the basic block we're processing.
-    // We want to see something that looks like:
-    // ```
-    // (StorageLive(_) | StorageDead(_));*
-    // _LOCAL_INTO = ((_LOCAL_FROM as Variant).FIELD: TY);
-    // (StorageLive(_) | StorageDead(_));*
-    // (tmp_n+1 = tmp_n);*
-    // (StorageLive(_) | StorageDead(_));*
-    // (tmp_n+1 = tmp_n);*
-    // ((LOCAL_FROM as Variant).FIELD: TY) = move tmp;
-    // discriminant(LOCAL_FROM) = VariantIdx;
-    // (StorageLive(_) | StorageDead(_));*
-    // ```
-    let mut stmt_iter = stmts.iter().enumerate().peekable();
-
-    try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
-
-    let (get_variant_field_stmt, stmt) = stmt_iter.next()?;
-    let (local_tmp_s0, local_1, vf_s0, dbg_projection) = match_get_variant_field(stmt)?;
-
-    try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
-
-    try_eat_assign_tmp_stmts(&mut stmt_iter, &mut tmp_assigns, &mut nop_stmts);
-
-    try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
-
-    try_eat_assign_tmp_stmts(&mut stmt_iter, &mut tmp_assigns, &mut nop_stmts);
-
-    let (idx, stmt) = stmt_iter.next()?;
-    let (local_tmp_s1, local_0, vf_s1) = match_set_variant_field(stmt)?;
-    nop_stmts.push(idx);
-
-    let (idx, stmt) = stmt_iter.next()?;
-    let (set_discr_local, set_discr_var_idx) = match_set_discr(stmt)?;
-    let discr_stmt_source_info = stmt.source_info;
-    nop_stmts.push(idx);
-
-    try_eat_storage_stmts(&mut stmt_iter, &mut storage_live_stmts, &mut storage_dead_stmts);
-
-    for (live_idx, live_local) in storage_live_stmts {
-        if let Some(i) = storage_dead_stmts.iter().rposition(|(_, l)| *l == live_local) {
-            let (dead_idx, _) = storage_dead_stmts.swap_remove(i);
-            storage_stmts.push((live_idx, dead_idx, live_local));
-
-            if live_local == local_tmp_s0 {
-                nop_stmts.push(get_variant_field_stmt);
-            }
-        }
-    }
-    // We sort primitive usize here so we can use unstable sort
-    nop_stmts.sort_unstable();
-
-    // Use one of the statements we're going to discard between the point
-    // where the storage location for the variant field becomes live and
-    // is killed.
-    let (live_idx, dead_idx) = find_storage_live_dead_stmts_for_local(local_tmp_s0, stmts)?;
-    let stmt_to_overwrite =
-        nop_stmts.iter().find(|stmt_idx| live_idx < **stmt_idx && **stmt_idx < dead_idx);
-
-    let mut tmp_assigned_vars = BitSet::new_empty(locals_count);
-    for (l, r) in &tmp_assigns {
-        tmp_assigned_vars.insert(*l);
-        tmp_assigned_vars.insert(*r);
-    }
-
-    let dbg_info_to_adjust: Vec<_> = debug_info
-        .iter()
-        .enumerate()
-        .filter_map(|(i, var_info)| {
-            if let VarDebugInfoContents::Place(p) = var_info.value {
-                if tmp_assigned_vars.contains(p.local) {
-                    return Some(i);
-                }
-            }
-
-            None
-        })
-        .collect();
-
-    Some(ArmIdentityInfo {
-        local_temp_0: local_tmp_s0,
-        local_1,
-        vf_s0,
-        get_variant_field_stmt,
-        field_tmp_assignments: tmp_assigns,
-        local_tmp_s1,
-        local_0,
-        vf_s1,
-        set_discr_local,
-        set_discr_var_idx,
-        stmt_to_overwrite: *stmt_to_overwrite?,
-        source_info: discr_stmt_source_info,
-        storage_stmts,
-        stmts_to_remove: nop_stmts,
-        dbg_info_to_adjust,
-        dbg_projection,
-    })
-}
-
-fn optimization_applies<'tcx>(
-    opt_info: &ArmIdentityInfo<'tcx>,
-    local_decls: &IndexVec<Local, LocalDecl<'tcx>>,
-    local_uses: &IndexVec<Local, usize>,
-    var_debug_info: &[VarDebugInfo<'tcx>],
-) -> bool {
-    trace!("testing if optimization applies...");
-
-    // FIXME(wesleywiser): possibly relax this restriction?
-    if opt_info.local_0 == opt_info.local_1 {
-        trace!("NO: moving into ourselves");
-        return false;
-    } else if opt_info.vf_s0 != opt_info.vf_s1 {
-        trace!("NO: the field-and-variant information do not match");
-        return false;
-    } else if local_decls[opt_info.local_0].ty != local_decls[opt_info.local_1].ty {
-        // FIXME(Centril,oli-obk): possibly relax to same layout?
-        trace!("NO: source and target locals have different types");
-        return false;
-    } else if (opt_info.local_0, opt_info.vf_s0.var_idx)
-        != (opt_info.set_discr_local, opt_info.set_discr_var_idx)
-    {
-        trace!("NO: the discriminants do not match");
-        return false;
-    }
-
-    // Verify the assignment chain consists of the form b = a; c = b; d = c; etc...
-    if opt_info.field_tmp_assignments.is_empty() {
-        trace!("NO: no assignments found");
-        return false;
-    }
-    let mut last_assigned_to = opt_info.field_tmp_assignments[0].1;
-    let source_local = last_assigned_to;
-    for (l, r) in &opt_info.field_tmp_assignments {
-        if *r != last_assigned_to {
-            trace!("NO: found unexpected assignment {:?} = {:?}", l, r);
-            return false;
-        }
-
-        last_assigned_to = *l;
-    }
-
-    // Check that the first and last used locals are only used twice
-    // since they are of the form:
-    //
-    // ```
-    // _first = ((_x as Variant).n: ty);
-    // _n = _first;
-    // ...
-    // ((_y as Variant).n: ty) = _n;
-    // discriminant(_y) = z;
-    // ```
-    for (l, r) in &opt_info.field_tmp_assignments {
-        if local_uses[*l] != 2 {
-            warn!("NO: FAILED assignment chain local {:?} was used more than twice", l);
-            return false;
-        } else if local_uses[*r] != 2 {
-            warn!("NO: FAILED assignment chain local {:?} was used more than twice", r);
-            return false;
-        }
-    }
-
-    // Check that debug info only points to full Locals and not projections.
-    for dbg_idx in &opt_info.dbg_info_to_adjust {
-        let dbg_info = &var_debug_info[*dbg_idx];
-        if let VarDebugInfoContents::Place(p) = dbg_info.value {
-            if !p.projection.is_empty() {
-                trace!("NO: debug info for {:?} had a projection {:?}", dbg_info.name, p);
-                return false;
-            }
-        }
-    }
-
-    if source_local != opt_info.local_temp_0 {
-        trace!(
-            "NO: start of assignment chain does not match enum variant temp: {:?} != {:?}",
-            source_local,
-            opt_info.local_temp_0
-        );
-        return false;
-    } else if last_assigned_to != opt_info.local_tmp_s1 {
-        trace!(
-            "NO: end of assignment chain does not match written enum temp: {:?} != {:?}",
-            last_assigned_to,
-            opt_info.local_tmp_s1
-        );
-        return false;
-    }
-
-    trace!("SUCCESS: optimization applies!");
-    true
-}
-
-impl<'tcx> MirPass<'tcx> for SimplifyArmIdentity {
-    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        // FIXME(77359): This optimization can result in unsoundness.
-        if !tcx.sess.opts.unstable_opts.unsound_mir_opts {
-            return;
-        }
-
-        let source = body.source;
-        trace!("running SimplifyArmIdentity on {:?}", source);
-
-        let local_uses = LocalUseCounter::get_local_uses(body);
-        for bb in body.basic_blocks.as_mut() {
-            if let Some(opt_info) =
-                get_arm_identity_info(&bb.statements, body.local_decls.len(), &body.var_debug_info)
-            {
-                trace!("got opt_info = {:#?}", opt_info);
-                if !optimization_applies(
-                    &opt_info,
-                    &body.local_decls,
-                    &local_uses,
-                    &body.var_debug_info,
-                ) {
-                    debug!("optimization skipped for {:?}", source);
-                    continue;
-                }
-
-                // Also remove unused Storage{Live,Dead} statements which correspond
-                // to temps used previously.
-                for (live_idx, dead_idx, local) in &opt_info.storage_stmts {
-                    // The temporary that we've read the variant field into is scoped to this block,
-                    // so we can remove the assignment.
-                    if *local == opt_info.local_temp_0 {
-                        bb.statements[opt_info.get_variant_field_stmt].make_nop();
-                    }
-
-                    for (left, right) in &opt_info.field_tmp_assignments {
-                        if local == left || local == right {
-                            bb.statements[*live_idx].make_nop();
-                            bb.statements[*dead_idx].make_nop();
-                        }
-                    }
-                }
-
-                // Right shape; transform
-                for stmt_idx in opt_info.stmts_to_remove {
-                    bb.statements[stmt_idx].make_nop();
-                }
-
-                let stmt = &mut bb.statements[opt_info.stmt_to_overwrite];
-                stmt.source_info = opt_info.source_info;
-                stmt.kind = StatementKind::Assign(Box::new((
-                    opt_info.local_0.into(),
-                    Rvalue::Use(Operand::Move(opt_info.local_1.into())),
-                )));
-
-                bb.statements.retain(|stmt| stmt.kind != StatementKind::Nop);
-
-                // Fix the debug info to point to the right local
-                for dbg_index in opt_info.dbg_info_to_adjust {
-                    let dbg_info = &mut body.var_debug_info[dbg_index];
-                    assert!(
-                        matches!(dbg_info.value, VarDebugInfoContents::Place(_)),
-                        "value was not a Place"
-                    );
-                    if let VarDebugInfoContents::Place(p) = &mut dbg_info.value {
-                        assert!(p.projection.is_empty());
-                        p.local = opt_info.local_0;
-                        p.projection = opt_info.dbg_projection;
-                    }
-                }
-
-                trace!("block is now {:?}", bb.statements);
-            }
-        }
-    }
-}
-
-struct LocalUseCounter {
-    local_uses: IndexVec<Local, usize>,
-}
-
-impl LocalUseCounter {
-    fn get_local_uses(body: &Body<'_>) -> IndexVec<Local, usize> {
-        let mut counter = LocalUseCounter { local_uses: IndexVec::from_elem(0, &body.local_decls) };
-        counter.visit_body(body);
-        counter.local_uses
-    }
-}
-
-impl Visitor<'_> for LocalUseCounter {
-    fn visit_local(&mut self, local: Local, context: PlaceContext, _location: Location) {
-        if context.is_storage_marker()
-            || context == PlaceContext::NonUse(NonUseContext::VarDebugInfo)
-        {
-            return;
-        }
-
-        self.local_uses[local] += 1;
-    }
-}
-
-/// Match on:
-/// ```ignore (MIR)
-/// _LOCAL_INTO = ((_LOCAL_FROM as Variant).FIELD: TY);
-/// ```
-fn match_get_variant_field<'tcx>(
-    stmt: &Statement<'tcx>,
-) -> Option<(Local, Local, VarField<'tcx>, &'tcx List<PlaceElem<'tcx>>)> {
-    match &stmt.kind {
-        StatementKind::Assign(box (
-            place_into,
-            Rvalue::Use(Operand::Copy(pf) | Operand::Move(pf)),
-        )) => {
-            let local_into = place_into.as_local()?;
-            let (local_from, vf) = match_variant_field_place(*pf)?;
-            Some((local_into, local_from, vf, pf.projection))
-        }
-        _ => None,
-    }
-}
-
-/// Match on:
-/// ```ignore (MIR)
-/// ((_LOCAL_FROM as Variant).FIELD: TY) = move _LOCAL_INTO;
-/// ```
-fn match_set_variant_field<'tcx>(stmt: &Statement<'tcx>) -> Option<(Local, Local, VarField<'tcx>)> {
-    match &stmt.kind {
-        StatementKind::Assign(box (place_from, Rvalue::Use(Operand::Move(place_into)))) => {
-            let local_into = place_into.as_local()?;
-            let (local_from, vf) = match_variant_field_place(*place_from)?;
-            Some((local_into, local_from, vf))
-        }
-        _ => None,
-    }
-}
-
-/// Match on:
-/// ```ignore (MIR)
-/// discriminant(_LOCAL_TO_SET) = VAR_IDX;
-/// ```
-fn match_set_discr(stmt: &Statement<'_>) -> Option<(Local, VariantIdx)> {
-    match &stmt.kind {
-        StatementKind::SetDiscriminant { place, variant_index } => {
-            Some((place.as_local()?, *variant_index))
-        }
-        _ => None,
-    }
-}
-
-#[derive(PartialEq, Debug)]
-struct VarField<'tcx> {
-    field: Field,
-    field_ty: Ty<'tcx>,
-    var_idx: VariantIdx,
-}
-
-/// Match on `((_LOCAL as Variant).FIELD: TY)`.
-fn match_variant_field_place(place: Place<'_>) -> Option<(Local, VarField<'_>)> {
-    match place.as_ref() {
-        PlaceRef {
-            local,
-            projection: &[ProjectionElem::Downcast(_, var_idx), ProjectionElem::Field(field, ty)],
-        } => Some((local, VarField { field, field_ty: ty, var_idx })),
-        _ => None,
-    }
-}
-
-/// Simplifies `SwitchInt(_) -> [targets]`,
-/// where all the `targets` have the same form,
-/// into `goto -> target_first`.
-pub struct SimplifyBranchSame;
-
-impl<'tcx> MirPass<'tcx> for SimplifyBranchSame {
-    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        // This optimization is disabled by default for now due to
-        // soundness concerns; see issue #89485 and PR #89489.
-        if !tcx.sess.opts.unstable_opts.unsound_mir_opts {
-            return;
-        }
-
-        trace!("Running SimplifyBranchSame on {:?}", body.source);
-        let finder = SimplifyBranchSameOptimizationFinder { body, tcx };
-        let opts = finder.find();
-
-        let did_remove_blocks = opts.len() > 0;
-        for opt in opts.iter() {
-            trace!("SUCCESS: Applying optimization {:?}", opt);
-            // Replace `SwitchInt(..) -> [bb_first, ..];` with a `goto -> bb_first;`.
-            body.basic_blocks_mut()[opt.bb_to_opt_terminator].terminator_mut().kind =
-                TerminatorKind::Goto { target: opt.bb_to_goto };
-        }
-
-        if did_remove_blocks {
-            // We have dead blocks now, so remove those.
-            simplify::remove_dead_blocks(tcx, body);
-        }
-    }
-}
-
-#[derive(Debug)]
-struct SimplifyBranchSameOptimization {
-    /// All basic blocks are equal so go to this one
-    bb_to_goto: BasicBlock,
-    /// Basic block where the terminator can be simplified to a goto
-    bb_to_opt_terminator: BasicBlock,
-}
-
-struct SwitchTargetAndValue {
-    target: BasicBlock,
-    // None in case of the `otherwise` case
-    value: Option<u128>,
-}
-
-struct SimplifyBranchSameOptimizationFinder<'a, 'tcx> {
-    body: &'a Body<'tcx>,
-    tcx: TyCtxt<'tcx>,
-}
-
-impl<'tcx> SimplifyBranchSameOptimizationFinder<'_, 'tcx> {
-    fn find(&self) -> Vec<SimplifyBranchSameOptimization> {
-        self.body
-            .basic_blocks
-            .iter_enumerated()
-            .filter_map(|(bb_idx, bb)| {
-                let (discr_switched_on, targets_and_values) = match &bb.terminator().kind {
-                    TerminatorKind::SwitchInt { targets, discr, .. } => {
-                        let targets_and_values: Vec<_> = targets.iter()
-                            .map(|(val, target)| SwitchTargetAndValue { target, value: Some(val) })
-                            .chain(once(SwitchTargetAndValue { target: targets.otherwise(), value: None }))
-                            .collect();
-                        (discr, targets_and_values)
-                    },
-                    _ => return None,
-                };
-
-                // find the adt that has its discriminant read
-                // assuming this must be the last statement of the block
-                let adt_matched_on = match &bb.statements.last()?.kind {
-                    StatementKind::Assign(box (place, rhs))
-                        if Some(*place) == discr_switched_on.place() =>
-                    {
-                        match rhs {
-                            Rvalue::Discriminant(adt_place) if adt_place.ty(self.body, self.tcx).ty.is_enum() => adt_place,
-                            _ => {
-                                trace!("NO: expected a discriminant read of an enum instead of: {:?}", rhs);
-                                return None;
-                            }
-                        }
-                    }
-                    other => {
-                        trace!("NO: expected an assignment of a discriminant read to a place. Found: {:?}", other);
-                        return None
-                    },
-                };
-
-                let mut iter_bbs_reachable = targets_and_values
-                    .iter()
-                    .map(|target_and_value| (target_and_value, &self.body.basic_blocks[target_and_value.target]))
-                    .filter(|(_, bb)| {
-                        // Reaching `unreachable` is UB so assume it doesn't happen.
-                        bb.terminator().kind != TerminatorKind::Unreachable
-                    })
-                    .peekable();
-
-                let bb_first = iter_bbs_reachable.peek().map_or(&targets_and_values[0], |(idx, _)| *idx);
-                let mut all_successors_equivalent = StatementEquality::TrivialEqual;
-
-                // All successor basic blocks must be equal or contain statements that are pairwise considered equal.
-                for ((target_and_value_l,bb_l), (target_and_value_r,bb_r)) in iter_bbs_reachable.tuple_windows() {
-                    let trivial_checks = bb_l.is_cleanup == bb_r.is_cleanup
-                                            && bb_l.terminator().kind == bb_r.terminator().kind
-                                            && bb_l.statements.len() == bb_r.statements.len();
-                    let statement_check = || {
-                        bb_l.statements.iter().zip(&bb_r.statements).try_fold(StatementEquality::TrivialEqual, |acc,(l,r)| {
-                            let stmt_equality = self.statement_equality(*adt_matched_on, &l, target_and_value_l, &r, target_and_value_r);
-                            if matches!(stmt_equality, StatementEquality::NotEqual) {
-                                // short circuit
-                                None
-                            } else {
-                                Some(acc.combine(&stmt_equality))
-                            }
-                        })
-                        .unwrap_or(StatementEquality::NotEqual)
-                    };
-                    if !trivial_checks {
-                        all_successors_equivalent = StatementEquality::NotEqual;
-                        break;
-                    }
-                    all_successors_equivalent = all_successors_equivalent.combine(&statement_check());
-                };
-
-                match all_successors_equivalent{
-                    StatementEquality::TrivialEqual => {
-                        // statements are trivially equal, so just take first
-                        trace!("Statements are trivially equal");
-                        Some(SimplifyBranchSameOptimization {
-                            bb_to_goto: bb_first.target,
-                            bb_to_opt_terminator: bb_idx,
-                        })
-                    }
-                    StatementEquality::ConsideredEqual(bb_to_choose) => {
-                        trace!("Statements are considered equal");
-                        Some(SimplifyBranchSameOptimization {
-                            bb_to_goto: bb_to_choose,
-                            bb_to_opt_terminator: bb_idx,
-                        })
-                    }
-                    StatementEquality::NotEqual => {
-                        trace!("NO: not all successors of basic block {:?} were equivalent", bb_idx);
-                        None
-                    }
-                }
-            })
-            .collect()
-    }
-
-    /// Tests if two statements can be considered equal
-    ///
-    /// Statements can be trivially equal if the kinds match.
-    /// But they can also be considered equal in the following case A:
-    /// ```ignore (MIR)
-    /// discriminant(_0) = 0;   // bb1
-    /// _0 = move _1;           // bb2
-    /// ```
-    /// In this case the two statements are equal iff
-    /// - `_0` is an enum where the variant index 0 is fieldless, and
-    /// -  bb1 was targeted by a switch where the discriminant of `_1` was switched on
-    fn statement_equality(
-        &self,
-        adt_matched_on: Place<'tcx>,
-        x: &Statement<'tcx>,
-        x_target_and_value: &SwitchTargetAndValue,
-        y: &Statement<'tcx>,
-        y_target_and_value: &SwitchTargetAndValue,
-    ) -> StatementEquality {
-        let helper = |rhs: &Rvalue<'tcx>,
-                      place: &Place<'tcx>,
-                      variant_index: VariantIdx,
-                      switch_value: u128,
-                      side_to_choose| {
-            let place_type = place.ty(self.body, self.tcx).ty;
-            let adt = match *place_type.kind() {
-                ty::Adt(adt, _) if adt.is_enum() => adt,
-                _ => return StatementEquality::NotEqual,
-            };
-            // We need to make sure that the switch value that targets the bb with
-            // SetDiscriminant is the same as the variant discriminant.
-            let variant_discr = adt.discriminant_for_variant(self.tcx, variant_index).val;
-            if variant_discr != switch_value {
-                trace!(
-                    "NO: variant discriminant {} does not equal switch value {}",
-                    variant_discr,
-                    switch_value
-                );
-                return StatementEquality::NotEqual;
-            }
-            let variant_is_fieldless = adt.variant(variant_index).fields.is_empty();
-            if !variant_is_fieldless {
-                trace!("NO: variant {:?} was not fieldless", variant_index);
-                return StatementEquality::NotEqual;
-            }
-
-            match rhs {
-                Rvalue::Use(operand) if operand.place() == Some(adt_matched_on) => {
-                    StatementEquality::ConsideredEqual(side_to_choose)
-                }
-                _ => {
-                    trace!(
-                        "NO: RHS of assignment was {:?}, but expected it to match the adt being matched on in the switch, which is {:?}",
-                        rhs,
-                        adt_matched_on
-                    );
-                    StatementEquality::NotEqual
-                }
-            }
-        };
-        match (&x.kind, &y.kind) {
-            // trivial case
-            (x, y) if x == y => StatementEquality::TrivialEqual,
-
-            // check for case A
-            (
-                StatementKind::Assign(box (_, rhs)),
-                &StatementKind::SetDiscriminant { ref place, variant_index },
-            ) if y_target_and_value.value.is_some() => {
-                // choose basic block of x, as that has the assign
-                helper(
-                    rhs,
-                    place,
-                    variant_index,
-                    y_target_and_value.value.unwrap(),
-                    x_target_and_value.target,
-                )
-            }
-            (
-                &StatementKind::SetDiscriminant { ref place, variant_index },
-                &StatementKind::Assign(box (_, ref rhs)),
-            ) if x_target_and_value.value.is_some() => {
-                // choose basic block of y, as that has the assign
-                helper(
-                    rhs,
-                    place,
-                    variant_index,
-                    x_target_and_value.value.unwrap(),
-                    y_target_and_value.target,
-                )
-            }
-            _ => {
-                trace!("NO: statements `{:?}` and `{:?}` not considered equal", x, y);
-                StatementEquality::NotEqual
-            }
-        }
-    }
-}
-
-#[derive(Copy, Clone, Eq, PartialEq)]
-enum StatementEquality {
-    /// The two statements are trivially equal; same kind
-    TrivialEqual,
-    /// The two statements are considered equal, but may be of different kinds. The BasicBlock field is the basic block to jump to when performing the branch-same optimization.
-    /// For example, `_0 = _1` and `discriminant(_0) = discriminant(0)` are considered equal if 0 is a fieldless variant of an enum. But we don't want to jump to the basic block with the SetDiscriminant, as that is not legal if _1 is not the 0 variant index
-    ConsideredEqual(BasicBlock),
-    /// The two statements are not equal
-    NotEqual,
-}
-
-impl StatementEquality {
-    fn combine(&self, other: &StatementEquality) -> StatementEquality {
-        use StatementEquality::*;
-        match (self, other) {
-            (TrivialEqual, TrivialEqual) => TrivialEqual,
-            (TrivialEqual, ConsideredEqual(b)) | (ConsideredEqual(b), TrivialEqual) => {
-                ConsideredEqual(*b)
-            }
-            (ConsideredEqual(b1), ConsideredEqual(b2)) => {
-                if b1 == b2 {
-                    ConsideredEqual(*b1)
-                } else {
-                    NotEqual
-                }
-            }
-            (_, NotEqual) | (NotEqual, _) => NotEqual,
-        }
-    }
-}
diff --git a/compiler/rustc_mir_transform/src/ssa.rs b/compiler/rustc_mir_transform/src/ssa.rs
new file mode 100644
index 00000000000..bc3fe65cf6c
--- /dev/null
+++ b/compiler/rustc_mir_transform/src/ssa.rs
@@ -0,0 +1,222 @@
+use either::Either;
+use rustc_data_structures::graph::dominators::Dominators;
+use rustc_index::bit_set::BitSet;
+use rustc_index::vec::IndexVec;
+use rustc_middle::middle::resolve_lifetime::Set1;
+use rustc_middle::mir::visit::*;
+use rustc_middle::mir::*;
+use rustc_middle::ty::{ParamEnv, TyCtxt};
+
+#[derive(Debug)]
+pub struct SsaLocals {
+    /// Assignments to each local. This defines whether the local is SSA.
+    assignments: IndexVec<Local, Set1<LocationExtended>>,
+    /// We visit the body in reverse postorder, to ensure each local is assigned before it is used.
+    /// We remember the order in which we saw the assignments to compute the SSA values in a single
+    /// pass.
+    assignment_order: Vec<Local>,
+    /// Copy equivalence classes between locals. See `copy_classes` for documentation.
+    copy_classes: IndexVec<Local, Local>,
+}
+
+impl SsaLocals {
+    pub fn new<'tcx>(
+        tcx: TyCtxt<'tcx>,
+        param_env: ParamEnv<'tcx>,
+        body: &Body<'tcx>,
+        borrowed_locals: &BitSet<Local>,
+    ) -> SsaLocals {
+        let assignment_order = Vec::new();
+
+        let assignments = IndexVec::from_elem(Set1::Empty, &body.local_decls);
+        let dominators = body.basic_blocks.dominators();
+        let mut visitor = SsaVisitor { assignments, assignment_order, dominators };
+
+        for (local, decl) in body.local_decls.iter_enumerated() {
+            if matches!(body.local_kind(local), LocalKind::Arg) {
+                visitor.assignments[local] = Set1::One(LocationExtended::Arg);
+            }
+            if borrowed_locals.contains(local) && !decl.ty.is_freeze(tcx, param_env) {
+                visitor.assignments[local] = Set1::Many;
+            }
+        }
+
+        for (bb, data) in traversal::reverse_postorder(body) {
+            visitor.visit_basic_block_data(bb, data);
+        }
+
+        for var_debug_info in &body.var_debug_info {
+            visitor.visit_var_debug_info(var_debug_info);
+        }
+
+        debug!(?visitor.assignments);
+
+        visitor
+            .assignment_order
+            .retain(|&local| matches!(visitor.assignments[local], Set1::One(_)));
+        debug!(?visitor.assignment_order);
+
+        let copy_classes = compute_copy_classes(&visitor, body);
+
+        SsaLocals {
+            assignments: visitor.assignments,
+            assignment_order: visitor.assignment_order,
+            copy_classes,
+        }
+    }
+
+    pub fn is_ssa(&self, local: Local) -> bool {
+        matches!(self.assignments[local], Set1::One(_))
+    }
+
+    pub fn assignments<'a, 'tcx>(
+        &'a self,
+        body: &'a Body<'tcx>,
+    ) -> impl Iterator<Item = (Local, &'a Rvalue<'tcx>)> + 'a {
+        self.assignment_order.iter().filter_map(|&local| {
+            if let Set1::One(LocationExtended::Plain(loc)) = self.assignments[local] {
+                // `loc` must point to a direct assignment to `local`.
+                let Either::Left(stmt) = body.stmt_at(loc) else { bug!() };
+                let Some((target, rvalue)) = stmt.kind.as_assign() else { bug!() };
+                assert_eq!(target.as_local(), Some(local));
+                Some((local, rvalue))
+            } else {
+                None
+            }
+        })
+    }
+
+    /// Compute the equivalence classes for locals, based on copy statements.
+    ///
+    /// The returned vector maps each local to the one it copies. In the following case:
+    ///   _a = &mut _0
+    ///   _b = move? _a
+    ///   _c = move? _a
+    ///   _d = move? _c
+    /// We return the mapping
+    ///   _a => _a // not a copy so, represented by itself
+    ///   _b => _a
+    ///   _c => _a
+    ///   _d => _a // transitively through _c
+    ///
+    /// Exception: we do not see through the return place, as it cannot be substituted.
+    pub fn copy_classes(&self) -> &IndexVec<Local, Local> {
+        &self.copy_classes
+    }
+
+    /// Make a property uniform on a copy equivalence class by removing elements.
+    pub fn meet_copy_equivalence(&self, property: &mut BitSet<Local>) {
+        // Consolidate to have a local iff all its copies are.
+        //
+        // `copy_classes` defines equivalence classes between locals. The `local`s that recursively
+        // move/copy the same local all have the same `head`.
+        for (local, &head) in self.copy_classes.iter_enumerated() {
+            // If any copy does not have `property`, then the head is not.
+            if !property.contains(local) {
+                property.remove(head);
+            }
+        }
+        for (local, &head) in self.copy_classes.iter_enumerated() {
+            // If any copy does not have `property`, then the head doesn't either,
+            // then no copy has `property`.
+            if !property.contains(head) {
+                property.remove(local);
+            }
+        }
+
+        // Verify that we correctly computed equivalence classes.
+        #[cfg(debug_assertions)]
+        for (local, &head) in self.copy_classes.iter_enumerated() {
+            assert_eq!(property.contains(local), property.contains(head));
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum LocationExtended {
+    Plain(Location),
+    Arg,
+}
+
+struct SsaVisitor {
+    dominators: Dominators<BasicBlock>,
+    assignments: IndexVec<Local, Set1<LocationExtended>>,
+    assignment_order: Vec<Local>,
+}
+
+impl<'tcx> Visitor<'tcx> for SsaVisitor {
+    fn visit_local(&mut self, local: Local, ctxt: PlaceContext, loc: Location) {
+        match ctxt {
+            PlaceContext::MutatingUse(MutatingUseContext::Store) => {
+                self.assignments[local].insert(LocationExtended::Plain(loc));
+                self.assignment_order.push(local);
+            }
+            // Anything can happen with raw pointers, so remove them.
+            PlaceContext::NonMutatingUse(NonMutatingUseContext::AddressOf)
+            | PlaceContext::MutatingUse(_) => self.assignments[local] = Set1::Many,
+            // Immutable borrows are taken into account in `SsaLocals::new` by
+            // removing non-freeze locals.
+            PlaceContext::NonMutatingUse(_) => {
+                let set = &mut self.assignments[local];
+                let assign_dominates = match *set {
+                    Set1::Empty | Set1::Many => false,
+                    Set1::One(LocationExtended::Arg) => true,
+                    Set1::One(LocationExtended::Plain(assign)) => {
+                        assign.successor_within_block().dominates(loc, &self.dominators)
+                    }
+                };
+                // We are visiting a use that is not dominated by an assignment.
+                // Either there is a cycle involved, or we are reading for uninitialized local.
+                // Bail out.
+                if !assign_dominates {
+                    *set = Set1::Many;
+                }
+            }
+            PlaceContext::NonUse(_) => {}
+        }
+    }
+}
+
+#[instrument(level = "trace", skip(ssa, body))]
+fn compute_copy_classes(ssa: &SsaVisitor, body: &Body<'_>) -> IndexVec<Local, Local> {
+    let mut copies = IndexVec::from_fn_n(|l| l, body.local_decls.len());
+
+    for &local in &ssa.assignment_order {
+        debug!(?local);
+
+        if local == RETURN_PLACE {
+            // `_0` is special, we cannot rename it.
+            continue;
+        }
+
+        // This is not SSA: mark that we don't know the value.
+        debug!(assignments = ?ssa.assignments[local]);
+        let Set1::One(LocationExtended::Plain(loc)) = ssa.assignments[local] else { continue };
+
+        // `loc` must point to a direct assignment to `local`.
+        let Either::Left(stmt) = body.stmt_at(loc) else { bug!() };
+        let Some((_target, rvalue)) = stmt.kind.as_assign() else { bug!() };
+        assert_eq!(_target.as_local(), Some(local));
+
+        let (Rvalue::Use(Operand::Copy(place) | Operand::Move(place)) | Rvalue::CopyForDeref(place))
+            = rvalue
+        else { continue };
+
+        let Some(rhs) = place.as_local() else { continue };
+        let Set1::One(_) = ssa.assignments[rhs] else { continue };
+
+        // We visit in `assignment_order`, ie. reverse post-order, so `rhs` has been
+        // visited before `local`, and we just have to copy the representing local.
+        copies[local] = copies[rhs];
+    }
+
+    debug!(?copies);
+
+    // Invariant: `copies` must point to the head of an equivalence class.
+    #[cfg(debug_assertions)]
+    for &head in copies.iter() {
+        assert_eq!(copies[head], head);
+    }
+
+    copies
+}
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index ec1de305687..305f0427e50 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1296,7 +1296,7 @@ impl<'v> RootCollector<'_, 'v> {
         };
 
         let start_def_id = self.tcx.require_lang_item(LangItem::Start, None);
-        let main_ret_ty = self.tcx.fn_sig(main_def_id).output();
+        let main_ret_ty = self.tcx.fn_sig(main_def_id).no_bound_vars().unwrap().output();
 
         // Given that `main()` has no arguments,
         // then its return type cannot have
diff --git a/compiler/rustc_monomorphize/src/partitioning/mod.rs b/compiler/rustc_monomorphize/src/partitioning/mod.rs
index fd6bcad1898..615126e8b58 100644
--- a/compiler/rustc_monomorphize/src/partitioning/mod.rs
+++ b/compiler/rustc_monomorphize/src/partitioning/mod.rs
@@ -180,7 +180,7 @@ pub fn partition<'tcx>(
         partitioner.place_root_mono_items(cx, mono_items)
     };
 
-    initial_partitioning.codegen_units.iter_mut().for_each(|cgu| cgu.estimate_size(tcx));
+    initial_partitioning.codegen_units.iter_mut().for_each(|cgu| cgu.create_size_estimate(tcx));
 
     debug_dump(tcx, "INITIAL PARTITIONING:", initial_partitioning.codegen_units.iter());
 
@@ -200,7 +200,7 @@ pub fn partition<'tcx>(
         partitioner.place_inlined_mono_items(cx, initial_partitioning)
     };
 
-    post_inlining.codegen_units.iter_mut().for_each(|cgu| cgu.estimate_size(tcx));
+    post_inlining.codegen_units.iter_mut().for_each(|cgu| cgu.create_size_estimate(tcx));
 
     debug_dump(tcx, "POST INLINING:", post_inlining.codegen_units.iter());
 
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 06b970ad979..054b41b478d 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -337,7 +337,9 @@ pub(crate) struct IfExpressionMissingThenBlock {
     #[primary_span]
     pub if_span: Span,
     #[subdiagnostic]
-    pub sub: IfExpressionMissingThenBlockSub,
+    pub missing_then_block_sub: IfExpressionMissingThenBlockSub,
+    #[subdiagnostic]
+    pub let_else_sub: Option<IfExpressionLetSomeSub>,
 }
 
 #[derive(Subdiagnostic)]
@@ -348,6 +350,13 @@ pub(crate) enum IfExpressionMissingThenBlockSub {
     AddThenBlock(#[primary_span] Span),
 }
 
+#[derive(Subdiagnostic)]
+#[help(parse_extra_if_in_let_else)]
+pub(crate) struct IfExpressionLetSomeSub {
+    #[primary_span]
+    pub if_span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(parse_if_expression_missing_condition)]
 pub(crate) struct IfExpressionMissingCondition {
@@ -640,6 +649,48 @@ pub(crate) struct MatchArmBodyWithoutBraces {
     pub sub: MatchArmBodyWithoutBracesSugg,
 }
 
+#[derive(Diagnostic)]
+#[diag(parse_inclusive_range_extra_equals)]
+#[note]
+pub(crate) struct InclusiveRangeExtraEquals {
+    #[primary_span]
+    #[suggestion(
+        suggestion_remove_eq,
+        style = "short",
+        code = "..=",
+        applicability = "maybe-incorrect"
+    )]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(parse_inclusive_range_match_arrow)]
+pub(crate) struct InclusiveRangeMatchArrow {
+    #[primary_span]
+    pub span: Span,
+    #[suggestion(
+        suggestion_add_space,
+        style = "verbose",
+        code = " ",
+        applicability = "machine-applicable"
+    )]
+    pub after_pat: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(parse_inclusive_range_no_end, code = "E0586")]
+#[note]
+pub(crate) struct InclusiveRangeNoEnd {
+    #[primary_span]
+    #[suggestion(
+        suggestion_open_range,
+        code = "..",
+        applicability = "machine-applicable",
+        style = "short"
+    )]
+    pub span: Span,
+}
+
 #[derive(Subdiagnostic)]
 pub(crate) enum MatchArmBodyWithoutBracesSugg {
     #[multipart_suggestion(suggestion_add_braces, applicability = "machine-applicable")]
diff --git a/compiler/rustc_parse/src/lexer/diagnostics.rs b/compiler/rustc_parse/src/lexer/diagnostics.rs
new file mode 100644
index 00000000000..386bf026bb4
--- /dev/null
+++ b/compiler/rustc_parse/src/lexer/diagnostics.rs
@@ -0,0 +1,119 @@
+use super::UnmatchedBrace;
+use rustc_ast::token::Delimiter;
+use rustc_errors::Diagnostic;
+use rustc_span::source_map::SourceMap;
+use rustc_span::Span;
+
+#[derive(Default)]
+pub struct TokenTreeDiagInfo {
+    /// Stack of open delimiters and their spans. Used for error message.
+    pub open_braces: Vec<(Delimiter, Span)>,
+    pub unmatched_braces: Vec<UnmatchedBrace>,
+
+    /// Used only for error recovery when arriving to EOF with mismatched braces.
+    pub last_unclosed_found_span: Option<Span>,
+
+    /// Collect empty block spans that might have been auto-inserted by editors.
+    pub empty_block_spans: Vec<Span>,
+
+    /// Collect the spans of braces (Open, Close). Used only
+    /// for detecting if blocks are empty and only braces.
+    pub matching_block_spans: Vec<(Span, Span)>,
+}
+
+pub fn same_identation_level(sm: &SourceMap, open_sp: Span, close_sp: Span) -> bool {
+    match (sm.span_to_margin(open_sp), sm.span_to_margin(close_sp)) {
+        (Some(open_padding), Some(close_padding)) => open_padding == close_padding,
+        _ => false,
+    }
+}
+
+// When we get a `)` or `]` for `{`, we should emit help message here
+// it's more friendly compared to report `unmatched error` in later phase
+pub fn report_missing_open_delim(
+    err: &mut Diagnostic,
+    unmatched_braces: &[UnmatchedBrace],
+) -> bool {
+    let mut reported_missing_open = false;
+    for unmatch_brace in unmatched_braces.iter() {
+        if let Some(delim) = unmatch_brace.found_delim
+            && matches!(delim, Delimiter::Parenthesis | Delimiter::Bracket)
+        {
+            let missed_open = match delim {
+                Delimiter::Parenthesis => "(",
+                Delimiter::Bracket => "[",
+                _ => unreachable!(),
+            };
+            err.span_label(
+                unmatch_brace.found_span.shrink_to_lo(),
+                format!("missing open `{}` for this delimiter", missed_open),
+            );
+            reported_missing_open = true;
+        }
+    }
+    reported_missing_open
+}
+
+pub fn report_suspicious_mismatch_block(
+    err: &mut Diagnostic,
+    diag_info: &TokenTreeDiagInfo,
+    sm: &SourceMap,
+    delim: Delimiter,
+) {
+    if report_missing_open_delim(err, &diag_info.unmatched_braces) {
+        return;
+    }
+
+    let mut matched_spans: Vec<(Span, bool)> = diag_info
+        .matching_block_spans
+        .iter()
+        .map(|&(open, close)| (open.with_hi(close.lo()), same_identation_level(sm, open, close)))
+        .collect();
+
+    // sort by `lo`, so the large block spans in the front
+    matched_spans.sort_by(|a, b| a.0.lo().cmp(&b.0.lo()));
+
+    // We use larger block whose identation is well to cover those inner mismatched blocks
+    // O(N^2) here, but we are on error reporting path, so it is fine
+    for i in 0..matched_spans.len() {
+        let (block_span, same_ident) = matched_spans[i];
+        if same_ident {
+            for j in i + 1..matched_spans.len() {
+                let (inner_block, inner_same_ident) = matched_spans[j];
+                if block_span.contains(inner_block) && !inner_same_ident {
+                    matched_spans[j] = (inner_block, true);
+                }
+            }
+        }
+    }
+
+    // Find the inner-most span candidate for final report
+    let candidate_span =
+        matched_spans.into_iter().rev().find(|&(_, same_ident)| !same_ident).map(|(span, _)| span);
+
+    if let Some(block_span) = candidate_span {
+        err.span_label(block_span.shrink_to_lo(), "this delimiter might not be properly closed...");
+        err.span_label(
+            block_span.shrink_to_hi(),
+            "...as it matches this but it has different indentation",
+        );
+
+        // If there is a empty block in the mismatched span, note it
+        if delim == Delimiter::Brace {
+            for span in diag_info.empty_block_spans.iter() {
+                if block_span.contains(*span) {
+                    err.span_label(*span, "block is empty, you might have not meant to close it");
+                    break;
+                }
+            }
+        }
+    } else {
+        // If there is no suspicious span, give the last properly closed block may help
+        if let Some(parent) = diag_info.matching_block_spans.last()
+            && diag_info.open_braces.last().is_none()
+            && diag_info.empty_block_spans.iter().all(|&sp| sp != parent.0.to(parent.1)) {
+                err.span_label(parent.0, "this opening brace...");
+                err.span_label(parent.1, "...matches this closing brace");
+        }
+    }
+}
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 9fe8d9836ba..e957224a033 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -17,6 +17,7 @@ use rustc_session::parse::ParseSess;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{edition::Edition, BytePos, Pos, Span};
 
+mod diagnostics;
 mod tokentrees;
 mod unescape_error_reporting;
 mod unicode_chars;
diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs
index b2701817d48..0de8f79112c 100644
--- a/compiler/rustc_parse/src/lexer/tokentrees.rs
+++ b/compiler/rustc_parse/src/lexer/tokentrees.rs
@@ -1,29 +1,18 @@
+use super::diagnostics::report_suspicious_mismatch_block;
+use super::diagnostics::same_identation_level;
+use super::diagnostics::TokenTreeDiagInfo;
 use super::{StringReader, UnmatchedBrace};
 use rustc_ast::token::{self, Delimiter, Token};
 use rustc_ast::tokenstream::{DelimSpan, Spacing, TokenStream, TokenTree};
 use rustc_ast_pretty::pprust::token_to_string;
-use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{PErr, PResult};
-use rustc_span::Span;
 
 pub(super) struct TokenTreesReader<'a> {
     string_reader: StringReader<'a>,
     /// The "next" token, which has been obtained from the `StringReader` but
     /// not yet handled by the `TokenTreesReader`.
     token: Token,
-    /// Stack of open delimiters and their spans. Used for error message.
-    open_braces: Vec<(Delimiter, Span)>,
-    unmatched_braces: Vec<UnmatchedBrace>,
-    /// The type and spans for all braces
-    ///
-    /// Used only for error recovery when arriving to EOF with mismatched braces.
-    matching_delim_spans: Vec<(Delimiter, Span, Span)>,
-    last_unclosed_found_span: Option<Span>,
-    /// Collect empty block spans that might have been auto-inserted by editors.
-    last_delim_empty_block_spans: FxHashMap<Delimiter, Span>,
-    /// Collect the spans of braces (Open, Close). Used only
-    /// for detecting if blocks are empty and only braces.
-    matching_block_spans: Vec<(Span, Span)>,
+    diag_info: TokenTreeDiagInfo,
 }
 
 impl<'a> TokenTreesReader<'a> {
@@ -33,15 +22,10 @@ impl<'a> TokenTreesReader<'a> {
         let mut tt_reader = TokenTreesReader {
             string_reader,
             token: Token::dummy(),
-            open_braces: Vec::new(),
-            unmatched_braces: Vec::new(),
-            matching_delim_spans: Vec::new(),
-            last_unclosed_found_span: None,
-            last_delim_empty_block_spans: FxHashMap::default(),
-            matching_block_spans: Vec::new(),
+            diag_info: TokenTreeDiagInfo::default(),
         };
         let res = tt_reader.parse_token_trees(/* is_delimited */ false);
-        (res, tt_reader.unmatched_braces)
+        (res, tt_reader.diag_info.unmatched_braces)
     }
 
     // Parse a stream of tokens into a list of `TokenTree`s.
@@ -92,9 +76,9 @@ impl<'a> TokenTreesReader<'a> {
     fn eof_err(&mut self) -> PErr<'a> {
         let msg = "this file contains an unclosed delimiter";
         let mut err = self.string_reader.sess.span_diagnostic.struct_span_err(self.token.span, msg);
-        for &(_, sp) in &self.open_braces {
+        for &(_, sp) in &self.diag_info.open_braces {
             err.span_label(sp, "unclosed delimiter");
-            self.unmatched_braces.push(UnmatchedBrace {
+            self.diag_info.unmatched_braces.push(UnmatchedBrace {
                 expected_delim: Delimiter::Brace,
                 found_delim: None,
                 found_span: self.token.span,
@@ -103,23 +87,13 @@ impl<'a> TokenTreesReader<'a> {
             });
         }
 
-        if let Some((delim, _)) = self.open_braces.last() {
-            if let Some((_, open_sp, close_sp)) =
-                self.matching_delim_spans.iter().find(|(d, open_sp, close_sp)| {
-                    let sm = self.string_reader.sess.source_map();
-                    if let Some(close_padding) = sm.span_to_margin(*close_sp) {
-                        if let Some(open_padding) = sm.span_to_margin(*open_sp) {
-                            return delim == d && close_padding != open_padding;
-                        }
-                    }
-                    false
-                })
-            // these are in reverse order as they get inserted on close, but
-            {
-                // we want the last open/first close
-                err.span_label(*open_sp, "this delimiter might not be properly closed...");
-                err.span_label(*close_sp, "...as it matches this but it has different indentation");
-            }
+        if let Some((delim, _)) = self.diag_info.open_braces.last() {
+            report_suspicious_mismatch_block(
+                &mut err,
+                &self.diag_info,
+                &self.string_reader.sess.source_map(),
+                *delim,
+            )
         }
         err
     }
@@ -128,7 +102,7 @@ impl<'a> TokenTreesReader<'a> {
         // The span for beginning of the delimited section
         let pre_span = self.token.span;
 
-        self.open_braces.push((open_delim, self.token.span));
+        self.diag_info.open_braces.push((open_delim, self.token.span));
 
         // Parse the token trees within the delimiters.
         // We stop at any delimiter so we can try to recover if the user
@@ -137,35 +111,29 @@ impl<'a> TokenTreesReader<'a> {
 
         // Expand to cover the entire delimited token tree
         let delim_span = DelimSpan::from_pair(pre_span, self.token.span);
+        let sm = self.string_reader.sess.source_map();
 
         match self.token.kind {
             // Correct delimiter.
             token::CloseDelim(close_delim) if close_delim == open_delim => {
-                let (open_brace, open_brace_span) = self.open_braces.pop().unwrap();
+                let (open_brace, open_brace_span) = self.diag_info.open_braces.pop().unwrap();
                 let close_brace_span = self.token.span;
 
-                if tts.is_empty() {
+                if tts.is_empty() && close_delim == Delimiter::Brace {
                     let empty_block_span = open_brace_span.to(close_brace_span);
-                    let sm = self.string_reader.sess.source_map();
                     if !sm.is_multiline(empty_block_span) {
                         // Only track if the block is in the form of `{}`, otherwise it is
                         // likely that it was written on purpose.
-                        self.last_delim_empty_block_spans.insert(open_delim, empty_block_span);
+                        self.diag_info.empty_block_spans.push(empty_block_span);
                     }
                 }
 
-                //only add braces
+                // only add braces
                 if let (Delimiter::Brace, Delimiter::Brace) = (open_brace, open_delim) {
-                    self.matching_block_spans.push((open_brace_span, close_brace_span));
+                    // Add all the matching spans, we will sort by span later
+                    self.diag_info.matching_block_spans.push((open_brace_span, close_brace_span));
                 }
 
-                if self.open_braces.is_empty() {
-                    // Clear up these spans to avoid suggesting them as we've found
-                    // properly matched delimiters so far for an entire block.
-                    self.matching_delim_spans.clear();
-                } else {
-                    self.matching_delim_spans.push((open_brace, open_brace_span, close_brace_span));
-                }
                 // Move past the closing delimiter.
                 self.token = self.string_reader.next_token().0;
             }
@@ -174,28 +142,25 @@ impl<'a> TokenTreesReader<'a> {
                 let mut unclosed_delimiter = None;
                 let mut candidate = None;
 
-                if self.last_unclosed_found_span != Some(self.token.span) {
+                if self.diag_info.last_unclosed_found_span != Some(self.token.span) {
                     // do not complain about the same unclosed delimiter multiple times
-                    self.last_unclosed_found_span = Some(self.token.span);
+                    self.diag_info.last_unclosed_found_span = Some(self.token.span);
                     // This is a conservative error: only report the last unclosed
                     // delimiter. The previous unclosed delimiters could actually be
                     // closed! The parser just hasn't gotten to them yet.
-                    if let Some(&(_, sp)) = self.open_braces.last() {
+                    if let Some(&(_, sp)) = self.diag_info.open_braces.last() {
                         unclosed_delimiter = Some(sp);
                     };
-                    let sm = self.string_reader.sess.source_map();
-                    if let Some(current_padding) = sm.span_to_margin(self.token.span) {
-                        for (brace, brace_span) in &self.open_braces {
-                            if let Some(padding) = sm.span_to_margin(*brace_span) {
-                                // high likelihood of these two corresponding
-                                if current_padding == padding && brace == &close_delim {
-                                    candidate = Some(*brace_span);
-                                }
-                            }
+                    for (brace, brace_span) in &self.diag_info.open_braces {
+                        if same_identation_level(&sm, self.token.span, *brace_span)
+                            && brace == &close_delim
+                        {
+                            // high likelihood of these two corresponding
+                            candidate = Some(*brace_span);
                         }
                     }
-                    let (tok, _) = self.open_braces.pop().unwrap();
-                    self.unmatched_braces.push(UnmatchedBrace {
+                    let (tok, _) = self.diag_info.open_braces.pop().unwrap();
+                    self.diag_info.unmatched_braces.push(UnmatchedBrace {
                         expected_delim: tok,
                         found_delim: Some(close_delim),
                         found_span: self.token.span,
@@ -203,7 +168,7 @@ impl<'a> TokenTreesReader<'a> {
                         candidate_span: candidate,
                     });
                 } else {
-                    self.open_braces.pop();
+                    self.diag_info.open_braces.pop();
                 }
 
                 // If the incorrect delimiter matches an earlier opening
@@ -213,7 +178,7 @@ impl<'a> TokenTreesReader<'a> {
                 // fn foo() {
                 //     bar(baz(
                 // }  // Incorrect delimiter but matches the earlier `{`
-                if !self.open_braces.iter().any(|&(b, _)| b == close_delim) {
+                if !self.diag_info.open_braces.iter().any(|&(b, _)| b == close_delim) {
                     self.token = self.string_reader.next_token().0;
                 }
             }
@@ -236,22 +201,12 @@ impl<'a> TokenTreesReader<'a> {
         let mut err =
             self.string_reader.sess.span_diagnostic.struct_span_err(self.token.span, &msg);
 
-        // Braces are added at the end, so the last element is the biggest block
-        if let Some(parent) = self.matching_block_spans.last() {
-            if let Some(span) = self.last_delim_empty_block_spans.remove(&delim) {
-                // Check if the (empty block) is in the last properly closed block
-                if (parent.0.to(parent.1)).contains(span) {
-                    err.span_label(span, "block is empty, you might have not meant to close it");
-                } else {
-                    err.span_label(parent.0, "this opening brace...");
-                    err.span_label(parent.1, "...matches this closing brace");
-                }
-            } else {
-                err.span_label(parent.0, "this opening brace...");
-                err.span_label(parent.1, "...matches this closing brace");
-            }
-        }
-
+        report_suspicious_mismatch_block(
+            &mut err,
+            &self.diag_info,
+            &self.string_reader.sess.source_map(),
+            delim,
+        );
         err.span_label(self.token.span, "unexpected closing delimiter");
         err
     }
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 4c918c6702e..f4c08031bcc 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -2353,6 +2353,28 @@ impl<'a> Parser<'a> {
         Err(err)
     }
 
+    /// Try to recover from an unbraced const argument whose first token [could begin a type][ty].
+    ///
+    /// [ty]: token::Token::can_begin_type
+    pub(crate) fn recover_unbraced_const_arg_that_can_begin_ty(
+        &mut self,
+        mut snapshot: SnapshotParser<'a>,
+    ) -> Option<P<ast::Expr>> {
+        match snapshot.parse_expr_res(Restrictions::CONST_EXPR, None) {
+            // Since we don't know the exact reason why we failed to parse the type or the
+            // expression, employ a simple heuristic to weed out some pathological cases.
+            Ok(expr) if let token::Comma | token::Gt = snapshot.token.kind => {
+                self.restore_snapshot(snapshot);
+                Some(expr)
+            }
+            Ok(_) => None,
+            Err(err) => {
+                err.cancel();
+                None
+            }
+        }
+    }
+
     /// Creates a dummy const argument, and reports that the expression must be enclosed in braces
     pub fn dummy_const_arg_needs_braces(
         &self,
@@ -2372,7 +2394,7 @@ impl<'a> Parser<'a> {
 
     /// Some special error handling for the "top-level" patterns in a match arm,
     /// `for` loop, `let`, &c. (in contrast to subpatterns within such).
-    pub(crate) fn maybe_recover_colon_colon_in_pat_typo(
+    pub(crate) fn maybe_recover_colon_colon_in_pat_typo_or_anon_enum(
         &mut self,
         mut first_pat: P<Pat>,
         expected: Expected,
@@ -2383,26 +2405,41 @@ impl<'a> Parser<'a> {
         if !matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..))
             || !self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident())
         {
+            let mut snapshot_type = self.create_snapshot_for_diagnostic();
+            snapshot_type.bump(); // `:`
+            match snapshot_type.parse_ty() {
+                Err(inner_err) => {
+                    inner_err.cancel();
+                }
+                Ok(ty) => {
+                    let Err(mut err) = self.expected_one_of_not_found(&[], &[]) else {
+                        return first_pat;
+                    };
+                    err.span_label(ty.span, "specifying the type of a pattern isn't supported");
+                    self.restore_snapshot(snapshot_type);
+                    let span = first_pat.span.to(ty.span);
+                    first_pat = self.mk_pat(span, PatKind::Wild);
+                    err.emit();
+                }
+            }
             return first_pat;
         }
         // The pattern looks like it might be a path with a `::` -> `:` typo:
         // `match foo { bar:baz => {} }`
-        let span = self.token.span;
+        let colon_span = self.token.span;
         // We only emit "unexpected `:`" error here if we can successfully parse the
         // whole pattern correctly in that case.
-        let snapshot = self.create_snapshot_for_diagnostic();
+        let mut snapshot_pat = self.create_snapshot_for_diagnostic();
+        let mut snapshot_type = self.create_snapshot_for_diagnostic();
 
         // Create error for "unexpected `:`".
         match self.expected_one_of_not_found(&[], &[]) {
             Err(mut err) => {
-                self.bump(); // Skip the `:`.
-                match self.parse_pat_no_top_alt(expected) {
+                snapshot_pat.bump(); // Skip the `:`.
+                snapshot_type.bump(); // Skip the `:`.
+                match snapshot_pat.parse_pat_no_top_alt(expected) {
                     Err(inner_err) => {
-                        // Carry on as if we had not done anything, callers will emit a
-                        // reasonable error.
                         inner_err.cancel();
-                        err.cancel();
-                        self.restore_snapshot(snapshot);
                     }
                     Ok(mut pat) => {
                         // We've parsed the rest of the pattern.
@@ -2466,8 +2503,8 @@ impl<'a> Parser<'a> {
                             _ => {}
                         }
                         if show_sugg {
-                            err.span_suggestion(
-                                span,
+                            err.span_suggestion_verbose(
+                                colon_span.until(self.look_ahead(1, |t| t.span)),
                                 "maybe write a path separator here",
                                 "::",
                                 Applicability::MaybeIncorrect,
@@ -2475,13 +2512,24 @@ impl<'a> Parser<'a> {
                         } else {
                             first_pat = self.mk_pat(new_span, PatKind::Wild);
                         }
-                        err.emit();
+                        self.restore_snapshot(snapshot_pat);
                     }
                 }
+                match snapshot_type.parse_ty() {
+                    Err(inner_err) => {
+                        inner_err.cancel();
+                    }
+                    Ok(ty) => {
+                        err.span_label(ty.span, "specifying the type of a pattern isn't supported");
+                        self.restore_snapshot(snapshot_type);
+                        let new_span = first_pat.span.to(ty.span);
+                        first_pat = self.mk_pat(new_span, PatKind::Wild);
+                    }
+                }
+                err.emit();
             }
             _ => {
                 // Carry on as if we had not done anything. This should be unreachable.
-                self.restore_snapshot(snapshot);
             }
         };
         first_pat
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index bf93a89f065..17d1e200b41 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -11,15 +11,15 @@ use crate::errors::{
     ComparisonOrShiftInterpretedAsGenericSugg, DoCatchSyntaxRemoved, DotDotDot, EqFieldInit,
     ExpectedElseBlock, ExpectedEqForLetExpr, ExpectedExpressionFoundLet,
     FieldExpressionWithGeneric, FloatLiteralRequiresIntegerPart, FoundExprWouldBeStmt,
-    IfExpressionMissingCondition, IfExpressionMissingThenBlock, IfExpressionMissingThenBlockSub,
-    InvalidBlockMacroSegment, InvalidComparisonOperator, InvalidComparisonOperatorSub,
-    InvalidInterpolatedExpression, InvalidLiteralSuffixOnTupleIndex, InvalidLogicalOperator,
-    InvalidLogicalOperatorSub, LabeledLoopInBreak, LeadingPlusNotSupported, LeftArrowOperator,
-    LifetimeInBorrowExpression, MacroInvocationWithQualifiedPath, MalformedLoopLabel,
-    MatchArmBodyWithoutBraces, MatchArmBodyWithoutBracesSugg, MissingCommaAfterMatchArm,
-    MissingDotDot, MissingInInForLoop, MissingInInForLoopSub, MissingSemicolonBeforeArray,
-    NoFieldsForFnCall, NotAsNegationOperator, NotAsNegationOperatorSub,
-    OuterAttributeNotAllowedOnIfElse, ParenthesesWithStructFields,
+    IfExpressionLetSomeSub, IfExpressionMissingCondition, IfExpressionMissingThenBlock,
+    IfExpressionMissingThenBlockSub, InvalidBlockMacroSegment, InvalidComparisonOperator,
+    InvalidComparisonOperatorSub, InvalidInterpolatedExpression, InvalidLiteralSuffixOnTupleIndex,
+    InvalidLogicalOperator, InvalidLogicalOperatorSub, LabeledLoopInBreak, LeadingPlusNotSupported,
+    LeftArrowOperator, LifetimeInBorrowExpression, MacroInvocationWithQualifiedPath,
+    MalformedLoopLabel, MatchArmBodyWithoutBraces, MatchArmBodyWithoutBracesSugg,
+    MissingCommaAfterMatchArm, MissingDotDot, MissingInInForLoop, MissingInInForLoopSub,
+    MissingSemicolonBeforeArray, NoFieldsForFnCall, NotAsNegationOperator,
+    NotAsNegationOperatorSub, OuterAttributeNotAllowedOnIfElse, ParenthesesWithStructFields,
     RequireColonAfterLabeledExpression, ShiftInterpretedAsGeneric, StructLiteralNotAllowedHere,
     StructLiteralNotAllowedHereSugg, TildeAsUnaryOperator, UnexpectedIfWithIf,
     UnexpectedTokenAfterLabel, UnexpectedTokenAfterLabelSugg, WrapExpressionInParentheses,
@@ -2251,9 +2251,10 @@ impl<'a> Parser<'a> {
                     if let ExprKind::Block(_, None) = right.kind => {
                         self.sess.emit_err(IfExpressionMissingThenBlock {
                             if_span: lo,
-                            sub: IfExpressionMissingThenBlockSub::UnfinishedCondition(
-                                cond_span.shrink_to_lo().to(*binop_span)
-                            ),
+                            missing_then_block_sub:
+                                IfExpressionMissingThenBlockSub::UnfinishedCondition(cond_span.shrink_to_lo().to(*binop_span)),
+                                let_else_sub: None,
+
                         });
                         std::mem::replace(right, this.mk_expr_err(binop_span.shrink_to_hi()))
                     },
@@ -2279,9 +2280,15 @@ impl<'a> Parser<'a> {
             if let Some(block) = recover_block_from_condition(self) {
                 block
             } else {
+                let let_else_sub = matches!(cond.kind, ExprKind::Let(..))
+                    .then(|| IfExpressionLetSomeSub { if_span: lo });
+
                 self.sess.emit_err(IfExpressionMissingThenBlock {
                     if_span: lo,
-                    sub: IfExpressionMissingThenBlockSub::AddThenBlock(cond_span.shrink_to_hi()),
+                    missing_then_block_sub: IfExpressionMissingThenBlockSub::AddThenBlock(
+                        cond_span.shrink_to_hi(),
+                    ),
+                    let_else_sub,
                 });
                 self.mk_block_err(cond_span.shrink_to_hi())
             }
@@ -3161,7 +3168,7 @@ impl<'a> Parser<'a> {
         limits: RangeLimits,
     ) -> ExprKind {
         if end.is_none() && limits == RangeLimits::Closed {
-            self.inclusive_range_with_incorrect_end(self.prev_token.span);
+            self.inclusive_range_with_incorrect_end();
             ExprKind::Err
         } else {
             ExprKind::Range(start, end, limits)
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index e73a17ced7d..912f7cc14f6 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -1,5 +1,7 @@
 use super::{ForceCollect, Parser, PathStyle, TrailingToken};
-use crate::errors::RemoveLet;
+use crate::errors::{
+    InclusiveRangeExtraEquals, InclusiveRangeMatchArrow, InclusiveRangeNoEnd, RemoveLet,
+};
 use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole};
 use rustc_ast::mut_visit::{noop_visit_pat, MutVisitor};
 use rustc_ast::ptr::P;
@@ -9,7 +11,7 @@ use rustc_ast::{
     PatField, PatKind, Path, QSelf, RangeEnd, RangeSyntax,
 };
 use rustc_ast_pretty::pprust;
-use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
+use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::{respan, Span, Spanned};
 use rustc_span::symbol::{kw, sym, Ident};
@@ -116,7 +118,8 @@ impl<'a> Parser<'a> {
 
             // Check if the user wrote `foo:bar` instead of `foo::bar`.
             if ra == RecoverColon::Yes {
-                first_pat = self.maybe_recover_colon_colon_in_pat_typo(first_pat, expected);
+                first_pat =
+                    self.maybe_recover_colon_colon_in_pat_typo_or_anon_enum(first_pat, expected);
             }
 
             if let Some(leading_vert_span) = leading_vert_span {
@@ -745,47 +748,52 @@ impl<'a> Parser<'a> {
             // Parsing e.g. `X..`.
             if let RangeEnd::Included(_) = re.node {
                 // FIXME(Centril): Consider semantic errors instead in `ast_validation`.
-                self.inclusive_range_with_incorrect_end(re.span);
+                self.inclusive_range_with_incorrect_end();
             }
             None
         };
         Ok(PatKind::Range(Some(begin), end, re))
     }
 
-    pub(super) fn inclusive_range_with_incorrect_end(&mut self, span: Span) {
+    pub(super) fn inclusive_range_with_incorrect_end(&mut self) {
         let tok = &self.token;
-
+        let span = self.prev_token.span;
         // If the user typed "..==" instead of "..=", we want to give them
         // a specific error message telling them to use "..=".
+        // If they typed "..=>", suggest they use ".. =>".
         // Otherwise, we assume that they meant to type a half open exclusive
         // range and give them an error telling them to do that instead.
-        if matches!(tok.kind, token::Eq) && tok.span.lo() == span.hi() {
-            let span_with_eq = span.to(tok.span);
+        let no_space = tok.span.lo() == span.hi();
+        match tok.kind {
+            token::Eq if no_space => {
+                let span_with_eq = span.to(tok.span);
 
-            // Ensure the user doesn't receive unhelpful unexpected token errors
-            self.bump();
-            if self.is_pat_range_end_start(0) {
-                let _ = self.parse_pat_range_end().map_err(|e| e.cancel());
-            }
+                // Ensure the user doesn't receive unhelpful unexpected token errors
+                self.bump();
+                if self.is_pat_range_end_start(0) {
+                    let _ = self.parse_pat_range_end().map_err(|e| e.cancel());
+                }
 
-            self.error_inclusive_range_with_extra_equals(span_with_eq);
-        } else {
-            self.error_inclusive_range_with_no_end(span);
+                self.error_inclusive_range_with_extra_equals(span_with_eq);
+            }
+            token::Gt if no_space => {
+                self.error_inclusive_range_match_arrow(span);
+            }
+            _ => self.error_inclusive_range_with_no_end(span),
         }
     }
 
     fn error_inclusive_range_with_extra_equals(&self, span: Span) {
-        self.struct_span_err(span, "unexpected `=` after inclusive range")
-            .span_suggestion_short(span, "use `..=` instead", "..=", Applicability::MaybeIncorrect)
-            .note("inclusive ranges end with a single equals sign (`..=`)")
-            .emit();
+        self.sess.emit_err(InclusiveRangeExtraEquals { span });
+    }
+
+    fn error_inclusive_range_match_arrow(&self, span: Span) {
+        let after_pat = span.with_hi(span.hi() - rustc_span::BytePos(1)).shrink_to_hi();
+        self.sess.emit_err(InclusiveRangeMatchArrow { span, after_pat });
     }
 
     fn error_inclusive_range_with_no_end(&self, span: Span) {
-        struct_span_err!(self.sess.span_diagnostic, span, E0586, "inclusive range with no end")
-            .span_suggestion_short(span, "use `..` instead", "..", Applicability::MachineApplicable)
-            .note("inclusive ranges must be bounded at the end (`..=b` or `a..=b`)")
-            .emit();
+        self.sess.emit_err(InclusiveRangeNoEnd { span });
     }
 
     /// Parse a range-to pattern, `..X` or `..=X` where `X` remains to be parsed.
diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs
index 5333d3b8587..2e706a00cf7 100644
--- a/compiler/rustc_parse/src/parser/path.rs
+++ b/compiler/rustc_parse/src/parser/path.rs
@@ -675,22 +675,42 @@ impl<'a> Parser<'a> {
             GenericArg::Const(self.parse_const_arg()?)
         } else if self.check_type() {
             // Parse type argument.
-            let is_const_fn =
-                self.look_ahead(1, |t| t.kind == token::OpenDelim(Delimiter::Parenthesis));
-            let mut snapshot = self.create_snapshot_for_diagnostic();
+
+            // Proactively create a parser snapshot enabling us to rewind and try to reparse the
+            // input as a const expression in case we fail to parse a type. If we successfully
+            // do so, we will report an error that it needs to be wrapped in braces.
+            let mut snapshot = None;
+            if self.may_recover() && self.token.can_begin_expr() {
+                snapshot = Some(self.create_snapshot_for_diagnostic());
+            }
+
             match self.parse_ty() {
-                Ok(ty) => GenericArg::Type(ty),
+                Ok(ty) => {
+                    // Since the type parser recovers from some malformed slice and array types and
+                    // successfully returns a type, we need to look for `TyKind::Err`s in the
+                    // type to determine if error recovery has occurred and if the input is not a
+                    // syntactically valid type after all.
+                    if let ast::TyKind::Slice(inner_ty) | ast::TyKind::Array(inner_ty, _) = &ty.kind
+                        && let ast::TyKind::Err = inner_ty.kind
+                        && let Some(snapshot) = snapshot
+                        && let Some(expr) = self.recover_unbraced_const_arg_that_can_begin_ty(snapshot)
+                    {
+                        return Ok(Some(self.dummy_const_arg_needs_braces(
+                            self.struct_span_err(expr.span, "invalid const generic expression"),
+                            expr.span,
+                        )));
+                    }
+
+                    GenericArg::Type(ty)
+                }
                 Err(err) => {
-                    if is_const_fn {
-                        match (*snapshot).parse_expr_res(Restrictions::CONST_EXPR, None) {
-                            Ok(expr) => {
-                                self.restore_snapshot(snapshot);
-                                return Ok(Some(self.dummy_const_arg_needs_braces(err, expr.span)));
-                            }
-                            Err(err) => {
-                                err.cancel();
-                            }
-                        }
+                    if let Some(snapshot) = snapshot
+                        && let Some(expr) = self.recover_unbraced_const_arg_that_can_begin_ty(snapshot)
+                    {
+                        return Ok(Some(self.dummy_const_arg_needs_braces(
+                            err,
+                            expr.span,
+                        )));
                     }
                     // Try to recover from possible `const` arg without braces.
                     return self.recover_const_arg(start, err).map(Some);
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
index 1766b0293de..82d9138c7a3 100644
--- a/compiler/rustc_parse/src/parser/ty.rs
+++ b/compiler/rustc_parse/src/parser/ty.rs
@@ -11,6 +11,7 @@ use rustc_ast::{
     self as ast, BareFnTy, FnRetTy, GenericBound, GenericBounds, GenericParam, Generics, Lifetime,
     MacCall, MutTy, Mutability, PolyTraitRef, TraitBoundModifier, TraitObjectSyntax, Ty, TyKind,
 };
+use rustc_ast_pretty::pprust;
 use rustc_errors::{pluralize, struct_span_err, Applicability, PResult};
 use rustc_span::source_map::Span;
 use rustc_span::symbol::{kw, sym, Ident};
@@ -43,17 +44,24 @@ pub(super) enum AllowPlus {
     No,
 }
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone, Copy)]
 pub(super) enum RecoverQPath {
     Yes,
     No,
 }
 
+#[derive(PartialEq, Clone, Copy)]
 pub(super) enum RecoverQuestionMark {
     Yes,
     No,
 }
 
+#[derive(PartialEq, Clone, Copy)]
+pub(super) enum RecoverAnonEnum {
+    Yes,
+    No,
+}
+
 /// Signals whether parsing a type should recover `->`.
 ///
 /// More specifically, when parsing a function like:
@@ -86,7 +94,7 @@ impl RecoverReturnSign {
 }
 
 // Is `...` (`CVarArgs`) legal at this level of type parsing?
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone, Copy)]
 enum AllowCVariadic {
     Yes,
     No,
@@ -111,6 +119,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             None,
             RecoverQuestionMark::Yes,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -125,6 +134,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             Some(ty_params),
             RecoverQuestionMark::Yes,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -139,6 +149,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             None,
             RecoverQuestionMark::Yes,
+            RecoverAnonEnum::Yes,
         )
     }
 
@@ -156,6 +167,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             None,
             RecoverQuestionMark::Yes,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -169,6 +181,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             None,
             RecoverQuestionMark::No,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -180,6 +193,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::Yes,
             None,
             RecoverQuestionMark::No,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -192,6 +206,7 @@ impl<'a> Parser<'a> {
             RecoverReturnSign::OnlyFatArrow,
             None,
             RecoverQuestionMark::Yes,
+            RecoverAnonEnum::No,
         )
     }
 
@@ -211,6 +226,7 @@ impl<'a> Parser<'a> {
                 recover_return_sign,
                 None,
                 RecoverQuestionMark::Yes,
+                RecoverAnonEnum::Yes,
             )?;
             FnRetTy::Ty(ty)
         } else if recover_return_sign.can_recover(&self.token.kind) {
@@ -232,6 +248,7 @@ impl<'a> Parser<'a> {
                 recover_return_sign,
                 None,
                 RecoverQuestionMark::Yes,
+                RecoverAnonEnum::Yes,
             )?;
             FnRetTy::Ty(ty)
         } else {
@@ -247,6 +264,7 @@ impl<'a> Parser<'a> {
         recover_return_sign: RecoverReturnSign,
         ty_generics: Option<&Generics>,
         recover_question_mark: RecoverQuestionMark,
+        recover_anon_enum: RecoverAnonEnum,
     ) -> PResult<'a, P<Ty>> {
         let allow_qpath_recovery = recover_qpath == RecoverQPath::Yes;
         maybe_recover_from_interpolated_ty_qpath!(self, allow_qpath_recovery);
@@ -325,14 +343,55 @@ impl<'a> Parser<'a> {
         let mut ty = self.mk_ty(span, kind);
 
         // Try to recover from use of `+` with incorrect priority.
-        if matches!(allow_plus, AllowPlus::Yes) {
+        if allow_plus == AllowPlus::Yes {
             self.maybe_recover_from_bad_type_plus(&ty)?;
         } else {
             self.maybe_report_ambiguous_plus(impl_dyn_multi, &ty);
         }
-        if let RecoverQuestionMark::Yes = recover_question_mark {
+        if RecoverQuestionMark::Yes == recover_question_mark {
             ty = self.maybe_recover_from_question_mark(ty);
         }
+        if recover_anon_enum == RecoverAnonEnum::Yes
+            && self.check_noexpect(&token::BinOp(token::Or))
+            && self.look_ahead(1, |t| t.can_begin_type())
+        {
+            let mut pipes = vec![self.token.span];
+            let mut types = vec![ty];
+            loop {
+                if !self.eat(&token::BinOp(token::Or)) {
+                    break;
+                }
+                pipes.push(self.prev_token.span);
+                types.push(self.parse_ty_common(
+                    allow_plus,
+                    allow_c_variadic,
+                    recover_qpath,
+                    recover_return_sign,
+                    ty_generics,
+                    recover_question_mark,
+                    RecoverAnonEnum::No,
+                )?);
+            }
+            let mut err = self.struct_span_err(pipes, "anonymous enums are not supported");
+            for ty in &types {
+                err.span_label(ty.span, "");
+            }
+            err.help(&format!(
+                "create a named `enum` and use it here instead:\nenum Name {{\n{}\n}}",
+                types
+                    .iter()
+                    .enumerate()
+                    .map(|(i, t)| format!(
+                        "    Variant{}({}),",
+                        i + 1, // Lets not confuse people with zero-indexing :)
+                        pprust::to_string(|s| s.print_type(&t)),
+                    ))
+                    .collect::<Vec<_>>()
+                    .join("\n"),
+            ));
+            err.emit();
+            return Ok(self.mk_ty(lo.to(self.prev_token.span), TyKind::Err));
+        }
         if allow_qpath_recovery { self.maybe_recover_from_bad_qpath(ty) } else { Ok(ty) }
     }
 
@@ -989,7 +1048,7 @@ impl<'a> Parser<'a> {
                 self.parse_remaining_bounds(bounds, true)?;
                 self.expect(&token::CloseDelim(Delimiter::Parenthesis))?;
                 let sp = vec![lo, self.prev_token.span];
-                let sugg: Vec<_> = sp.iter().map(|sp| (*sp, String::new())).collect();
+                let sugg = vec![(lo, String::from(" ")), (self.prev_token.span, String::new())];
                 self.struct_span_err(sp, "incorrect braces around trait bounds")
                     .multipart_suggestion(
                         "remove the parentheses",
diff --git a/compiler/rustc_parse_format/src/lib.rs b/compiler/rustc_parse_format/src/lib.rs
index 7b016cadac3..a6dfcd29762 100644
--- a/compiler/rustc_parse_format/src/lib.rs
+++ b/compiler/rustc_parse_format/src/lib.rs
@@ -16,7 +16,6 @@
 
 pub use Alignment::*;
 pub use Count::*;
-pub use Flag::*;
 pub use Piece::*;
 pub use Position::*;
 
@@ -111,8 +110,14 @@ pub struct FormatSpec<'a> {
     pub fill: Option<char>,
     /// Optionally specified alignment.
     pub align: Alignment,
-    /// Packed version of various flags provided.
-    pub flags: u32,
+    /// The `+` or `-` flag.
+    pub sign: Option<Sign>,
+    /// The `#` flag.
+    pub alternate: bool,
+    /// The `0` flag.
+    pub zero_pad: bool,
+    /// The `x` or `X` flag. (Only for `Debug`.)
+    pub debug_hex: Option<DebugHex>,
     /// The integer precision to use.
     pub precision: Count<'a>,
     /// The span of the precision formatting flag (for diagnostics).
@@ -162,24 +167,22 @@ pub enum Alignment {
     AlignUnknown,
 }
 
-/// Various flags which can be applied to format strings. The meaning of these
-/// flags is defined by the formatters themselves.
+/// Enum for the sign flags.
 #[derive(Copy, Clone, Debug, PartialEq)]
-pub enum Flag {
-    /// A `+` will be used to denote positive numbers.
-    FlagSignPlus,
-    /// A `-` will be used to denote negative numbers. This is the default.
-    FlagSignMinus,
-    /// An alternate form will be used for the value. In the case of numbers,
-    /// this means that the number will be prefixed with the supplied string.
-    FlagAlternate,
-    /// For numbers, this means that the number will be padded with zeroes,
-    /// and the sign (`+` or `-`) will precede them.
-    FlagSignAwareZeroPad,
-    /// For Debug / `?`, format integers in lower-case hexadecimal.
-    FlagDebugLowerHex,
-    /// For Debug / `?`, format integers in upper-case hexadecimal.
-    FlagDebugUpperHex,
+pub enum Sign {
+    /// The `+` flag.
+    Plus,
+    /// The `-` flag.
+    Minus,
+}
+
+/// Enum for the debug hex flags.
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum DebugHex {
+    /// The `x` flag in `{:x?}`.
+    Lower,
+    /// The `X` flag in `{:X?}`.
+    Upper,
 }
 
 /// A count is used for the precision and width parameters of an integer, and
@@ -597,7 +600,10 @@ impl<'a> Parser<'a> {
         let mut spec = FormatSpec {
             fill: None,
             align: AlignUnknown,
-            flags: 0,
+            sign: None,
+            alternate: false,
+            zero_pad: false,
+            debug_hex: None,
             precision: CountImplied,
             precision_span: None,
             width: CountImplied,
@@ -626,13 +632,13 @@ impl<'a> Parser<'a> {
         }
         // Sign flags
         if self.consume('+') {
-            spec.flags |= 1 << (FlagSignPlus as u32);
+            spec.sign = Some(Sign::Plus);
         } else if self.consume('-') {
-            spec.flags |= 1 << (FlagSignMinus as u32);
+            spec.sign = Some(Sign::Minus);
         }
         // Alternate marker
         if self.consume('#') {
-            spec.flags |= 1 << (FlagAlternate as u32);
+            spec.alternate = true;
         }
         // Width and precision
         let mut havewidth = false;
@@ -647,7 +653,7 @@ impl<'a> Parser<'a> {
                 spec.width_span = Some(self.span(end - 1, end + 1));
                 havewidth = true;
             } else {
-                spec.flags |= 1 << (FlagSignAwareZeroPad as u32);
+                spec.zero_pad = true;
             }
         }
 
@@ -678,14 +684,14 @@ impl<'a> Parser<'a> {
         // Optional radix followed by the actual format specifier
         if self.consume('x') {
             if self.consume('?') {
-                spec.flags |= 1 << (FlagDebugLowerHex as u32);
+                spec.debug_hex = Some(DebugHex::Lower);
                 spec.ty = "?";
             } else {
                 spec.ty = "x";
             }
         } else if self.consume('X') {
             if self.consume('?') {
-                spec.flags |= 1 << (FlagDebugUpperHex as u32);
+                spec.debug_hex = Some(DebugHex::Upper);
                 spec.ty = "?";
             } else {
                 spec.ty = "X";
@@ -708,7 +714,10 @@ impl<'a> Parser<'a> {
         let mut spec = FormatSpec {
             fill: None,
             align: AlignUnknown,
-            flags: 0,
+            sign: None,
+            alternate: false,
+            zero_pad: false,
+            debug_hex: None,
             precision: CountImplied,
             precision_span: None,
             width: CountImplied,
diff --git a/compiler/rustc_parse_format/src/tests.rs b/compiler/rustc_parse_format/src/tests.rs
index 2992ba845ab..45314e2fb55 100644
--- a/compiler/rustc_parse_format/src/tests.rs
+++ b/compiler/rustc_parse_format/src/tests.rs
@@ -10,7 +10,10 @@ fn fmtdflt() -> FormatSpec<'static> {
     return FormatSpec {
         fill: None,
         align: AlignUnknown,
-        flags: 0,
+        sign: None,
+        alternate: false,
+        zero_pad: false,
+        debug_hex: None,
         precision: CountImplied,
         width: CountImplied,
         precision_span: None,
@@ -126,7 +129,10 @@ fn format_type() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -147,7 +153,10 @@ fn format_align_fill() {
             format: FormatSpec {
                 fill: None,
                 align: AlignRight,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -165,7 +174,10 @@ fn format_align_fill() {
             format: FormatSpec {
                 fill: Some('0'),
                 align: AlignLeft,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -183,7 +195,10 @@ fn format_align_fill() {
             format: FormatSpec {
                 fill: Some('*'),
                 align: AlignLeft,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -204,7 +219,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 precision_span: None,
                 width: CountIs(10),
@@ -222,7 +240,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIs(10),
                 precision_span: Some(InnerSpan { start: 6, end: 9 }),
                 width: CountIsParam(10),
@@ -240,7 +261,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIs(10),
                 precision_span: Some(InnerSpan { start: 6, end: 9 }),
                 width: CountIsParam(0),
@@ -258,7 +282,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIsStar(0),
                 precision_span: Some(InnerSpan { start: 3, end: 5 }),
                 width: CountImplied,
@@ -276,7 +303,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIsParam(10),
                 width: CountImplied,
                 precision_span: Some(InnerSpan::new(3, 7)),
@@ -294,7 +324,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIsName("b", InnerSpan { start: 6, end: 7 }),
                 precision_span: Some(InnerSpan { start: 5, end: 8 }),
                 width: CountIsName("a", InnerSpan { start: 3, end: 4 }),
@@ -312,7 +345,10 @@ fn format_counts() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: 0,
+                sign: None,
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountIs(4),
                 precision_span: Some(InnerSpan { start: 3, end: 5 }),
                 width: CountImplied,
@@ -333,7 +369,10 @@ fn format_flags() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: (1 << FlagSignMinus as u32),
+                sign: Some(Sign::Minus),
+                alternate: false,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -351,7 +390,10 @@ fn format_flags() {
             format: FormatSpec {
                 fill: None,
                 align: AlignUnknown,
-                flags: (1 << FlagSignPlus as u32) | (1 << FlagAlternate as u32),
+                sign: Some(Sign::Plus),
+                alternate: true,
+                zero_pad: false,
+                debug_hex: None,
                 precision: CountImplied,
                 width: CountImplied,
                 precision_span: None,
@@ -374,7 +416,10 @@ fn format_mixture() {
                 format: FormatSpec {
                     fill: None,
                     align: AlignUnknown,
-                    flags: 0,
+                    sign: None,
+                    alternate: false,
+                    zero_pad: false,
+                    debug_hex: None,
                     precision: CountImplied,
                     width: CountImplied,
                     precision_span: None,
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index f9f9799d3e4..25cc65ba04c 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -6,11 +6,12 @@
 
 use crate::errors::{
     self, AttrApplication, DebugVisualizerUnreadable, InvalidAttrAtCrateLevel, ObjectLifetimeErr,
-    OnlyHasEffectOn, TransparentIncompatible, UnrecognizedReprHint,
+    OnlyHasEffectOn, ProcMacroDiffArguments, ProcMacroInvalidAbi, ProcMacroMissingArguments,
+    ProcMacroTypeError, ProcMacroUnsafe, TransparentIncompatible, UnrecognizedReprHint,
 };
 use rustc_ast::{ast, AttrStyle, Attribute, LitKind, MetaItemKind, MetaItemLit, NestedMetaItem};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_errors::{fluent, Applicability, MultiSpan};
+use rustc_errors::{fluent, Applicability, IntoDiagnosticArg, MultiSpan};
 use rustc_expand::base::resolve_path;
 use rustc_feature::{AttributeDuplicates, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_hir as hir;
@@ -19,11 +20,12 @@ use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{
     self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID, CRATE_OWNER_ID,
 };
-use rustc_hir::{MethodKind, Target};
+use rustc_hir::{MethodKind, Target, Unsafety};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
+use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::TyCtxt;
+use rustc_middle::ty::{ParamEnv, TyCtxt};
 use rustc_session::lint::builtin::{
     CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, UNUSED_ATTRIBUTES,
 };
@@ -31,6 +33,7 @@ use rustc_session::parse::feature_err;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
+use std::cell::Cell;
 use std::collections::hash_map::Entry;
 
 pub(crate) fn target_from_impl_item<'tcx>(
@@ -62,8 +65,29 @@ enum ItemLike<'tcx> {
     ForeignItem,
 }
 
+#[derive(Copy, Clone)]
+pub(crate) enum ProcMacroKind {
+    FunctionLike,
+    Derive,
+    Attribute,
+}
+
+impl IntoDiagnosticArg for ProcMacroKind {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+        match self {
+            ProcMacroKind::Attribute => "attribute proc macro",
+            ProcMacroKind::Derive => "derive proc macro",
+            ProcMacroKind::FunctionLike => "function-like proc macro",
+        }
+        .into_diagnostic_arg()
+    }
+}
+
 struct CheckAttrVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
+
+    // Whether or not this visitor should abort after finding errors
+    abort: Cell<bool>,
 }
 
 impl CheckAttrVisitor<'_> {
@@ -173,7 +197,7 @@ impl CheckAttrVisitor<'_> {
                 sym::path => self.check_generic_attr(hir_id, attr, target, Target::Mod),
                 sym::plugin_registrar => self.check_plugin_registrar(hir_id, attr, target),
                 sym::macro_export => self.check_macro_export(hir_id, attr, target),
-                sym::ignore | sym::should_panic | sym::proc_macro_derive => {
+                sym::ignore | sym::should_panic => {
                     self.check_generic_attr(hir_id, attr, target, Target::Fn)
                 }
                 sym::automatically_derived => {
@@ -183,6 +207,16 @@ impl CheckAttrVisitor<'_> {
                     self.check_generic_attr(hir_id, attr, target, Target::Mod)
                 }
                 sym::rustc_object_lifetime_default => self.check_object_lifetime_default(hir_id),
+                sym::proc_macro => {
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike)
+                }
+                sym::proc_macro_attribute => {
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::Attribute);
+                }
+                sym::proc_macro_derive => {
+                    self.check_generic_attr(hir_id, attr, target, Target::Fn);
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::Derive)
+                }
                 _ => {}
             }
 
@@ -419,7 +453,9 @@ impl CheckAttrVisitor<'_> {
     /// Debugging aid for `object_lifetime_default` query.
     fn check_object_lifetime_default(&self, hir_id: HirId) {
         let tcx = self.tcx;
-        if let Some(generics) = tcx.hir().get_generics(tcx.hir().local_def_id(hir_id)) {
+        if let Some(owner_id) = hir_id.as_owner()
+            && let Some(generics) = tcx.hir().get_generics(owner_id.def_id)
+        {
             for p in generics.params {
                 let hir::GenericParamKind::Type { .. } = p.kind else { continue };
                 let default = tcx.object_lifetime_default(p.def_id);
@@ -1909,7 +1945,7 @@ impl CheckAttrVisitor<'_> {
     ) -> bool {
         match target {
             Target::Fn | Target::Method(_)
-                if self.tcx.is_const_fn_raw(self.tcx.hir().local_def_id(hir_id).to_def_id()) =>
+                if self.tcx.is_const_fn_raw(hir_id.expect_owner().to_def_id()) =>
             {
                 true
             }
@@ -2063,6 +2099,104 @@ impl CheckAttrVisitor<'_> {
             errors::Unused { attr_span: attr.span, note },
         );
     }
+
+    /// A best effort attempt to create an error for a mismatching proc macro signature.
+    ///
+    /// If this best effort goes wrong, it will just emit a worse error later (see #102923)
+    fn check_proc_macro(&self, hir_id: HirId, target: Target, kind: ProcMacroKind) {
+        let expected_input_count = match kind {
+            ProcMacroKind::Attribute => 2,
+            ProcMacroKind::Derive | ProcMacroKind::FunctionLike => 1,
+        };
+
+        let expected_signature = match kind {
+            ProcMacroKind::Attribute => "fn(TokenStream, TokenStream) -> TokenStream",
+            ProcMacroKind::Derive | ProcMacroKind::FunctionLike => "fn(TokenStream) -> TokenStream",
+        };
+
+        let tcx = self.tcx;
+        if target == Target::Fn {
+            let Some(tokenstream) = tcx.get_diagnostic_item(sym::TokenStream) else {return};
+            let tokenstream = tcx.type_of(tokenstream);
+
+            let id = hir_id.expect_owner();
+            let hir_sig = tcx.hir().fn_sig_by_hir_id(hir_id).unwrap();
+
+            let sig =
+                tcx.liberate_late_bound_regions(id.to_def_id(), tcx.fn_sig(id).subst_identity());
+            let sig = tcx.normalize_erasing_regions(ParamEnv::empty(), sig);
+
+            // We don't currently require that the function signature is equal to
+            // `fn(TokenStream) -> TokenStream`, but instead monomorphizes to
+            // `fn(TokenStream) -> TokenStream` after some substitution of generic arguments.
+            //
+            // Properly checking this means pulling in additional `rustc` crates, so we don't.
+            let drcx = DeepRejectCtxt { treat_obligation_params: TreatParams::AsInfer };
+
+            if sig.abi != Abi::Rust {
+                tcx.sess.emit_err(ProcMacroInvalidAbi { span: hir_sig.span, abi: sig.abi.name() });
+                self.abort.set(true);
+            }
+
+            if sig.unsafety == Unsafety::Unsafe {
+                tcx.sess.emit_err(ProcMacroUnsafe { span: hir_sig.span });
+                self.abort.set(true);
+            }
+
+            let output = sig.output();
+
+            // Typecheck the output
+            if !drcx.types_may_unify(output, tokenstream) {
+                tcx.sess.emit_err(ProcMacroTypeError {
+                    span: hir_sig.decl.output.span(),
+                    found: output,
+                    kind,
+                    expected_signature,
+                });
+                self.abort.set(true);
+            }
+
+            if sig.inputs().len() < expected_input_count {
+                tcx.sess.emit_err(ProcMacroMissingArguments {
+                    expected_input_count,
+                    span: hir_sig.span,
+                    kind,
+                    expected_signature,
+                });
+                self.abort.set(true);
+            }
+
+            // Check that the inputs are correct, if there are enough.
+            if sig.inputs().len() >= expected_input_count {
+                for (arg, input) in
+                    sig.inputs().iter().zip(hir_sig.decl.inputs).take(expected_input_count)
+                {
+                    if !drcx.types_may_unify(*arg, tokenstream) {
+                        tcx.sess.emit_err(ProcMacroTypeError {
+                            span: input.span,
+                            found: *arg,
+                            kind,
+                            expected_signature,
+                        });
+                        self.abort.set(true);
+                    }
+                }
+            }
+
+            // Check that there are not too many arguments
+            let body_id = tcx.hir().body_owned_by(id.def_id);
+            let excess = tcx.hir().body(body_id).params.get(expected_input_count..);
+            if let Some(excess @ [begin @ end] | excess @ [begin, .., end]) = excess {
+                tcx.sess.emit_err(ProcMacroDiffArguments {
+                    span: begin.span.to(end.span),
+                    count: excess.len(),
+                    kind,
+                    expected_signature,
+                });
+                self.abort.set(true);
+            }
+        }
+    }
 }
 
 impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
@@ -2225,12 +2359,15 @@ fn check_non_exported_macro_for_invalid_attrs(tcx: TyCtxt<'_>, item: &Item<'_>)
 }
 
 fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
-    let check_attr_visitor = &mut CheckAttrVisitor { tcx };
+    let check_attr_visitor = &mut CheckAttrVisitor { tcx, abort: Cell::new(false) };
     tcx.hir().visit_item_likes_in_module(module_def_id, check_attr_visitor);
     if module_def_id.is_top_level_module() {
         check_attr_visitor.check_attributes(CRATE_HIR_ID, DUMMY_SP, Target::Mod, None);
         check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs());
     }
+    if check_attr_visitor.abort.get() {
+        tcx.sess.abort_if_errors()
+    }
 }
 
 pub(crate) fn provide(providers: &mut Providers) {
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index aa726d6cd92..dd8c646a43c 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -48,7 +48,7 @@ impl NonConstExpr {
             Self::Match(TryDesugar) => &[sym::const_try],
 
             // All other expressions are allowed.
-            Self::Loop(Loop | While) | Self::Match(Normal) => &[],
+            Self::Loop(Loop | While) | Self::Match(Normal | FormatArgs) => &[],
         };
 
         Some(gates)
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 94171b4b0c8..83adfeb6b10 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -451,47 +451,40 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
         // referenced by it should be considered as used.
         let in_pat = mem::replace(&mut self.in_pat, false);
 
-        self.live_symbols.insert(self.tcx.hir().local_def_id(c.hir_id));
+        self.live_symbols.insert(c.def_id);
         intravisit::walk_anon_const(self, c);
 
         self.in_pat = in_pat;
     }
 }
 
-fn has_allow_dead_code_or_lang_attr_helper(
-    tcx: TyCtxt<'_>,
-    id: hir::HirId,
-    lint: &'static lint::Lint,
-) -> bool {
-    let attrs = tcx.hir().attrs(id);
-    if tcx.sess.contains_name(attrs, sym::lang) {
-        return true;
+fn has_allow_dead_code_or_lang_attr(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
+    fn has_lang_attr(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
+        tcx.has_attr(def_id.to_def_id(), sym::lang)
+            // Stable attribute for #[lang = "panic_impl"]
+            || tcx.has_attr(def_id.to_def_id(), sym::panic_handler)
     }
 
-    // Stable attribute for #[lang = "panic_impl"]
-    if tcx.sess.contains_name(attrs, sym::panic_handler) {
-        return true;
+    fn has_allow_dead_code(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
+        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
+        tcx.lint_level_at_node(lint::builtin::DEAD_CODE, hir_id).0 == lint::Allow
     }
 
-    let def_id = tcx.hir().local_def_id(id);
-    if tcx.def_kind(def_id).has_codegen_attrs() {
-        let cg_attrs = tcx.codegen_fn_attrs(def_id);
+    fn has_used_like_attr(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
+        tcx.def_kind(def_id).has_codegen_attrs() && {
+            let cg_attrs = tcx.codegen_fn_attrs(def_id);
 
-        // #[used], #[no_mangle], #[export_name], etc also keeps the item alive
-        // forcefully, e.g., for placing it in a specific section.
-        if cg_attrs.contains_extern_indicator()
-            || cg_attrs.flags.contains(CodegenFnAttrFlags::USED)
-            || cg_attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)
-        {
-            return true;
+            // #[used], #[no_mangle], #[export_name], etc also keeps the item alive
+            // forcefully, e.g., for placing it in a specific section.
+            cg_attrs.contains_extern_indicator()
+                || cg_attrs.flags.contains(CodegenFnAttrFlags::USED)
+                || cg_attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)
         }
     }
 
-    tcx.lint_level_at_node(lint, id).0 == lint::Allow
-}
-
-fn has_allow_dead_code_or_lang_attr(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
-    has_allow_dead_code_or_lang_attr_helper(tcx, id, lint::builtin::DEAD_CODE)
+    has_allow_dead_code(tcx, def_id)
+        || has_used_like_attr(tcx, def_id)
+        || has_lang_attr(tcx, def_id)
 }
 
 // These check_* functions seeds items that
@@ -513,7 +506,7 @@ fn check_item<'tcx>(
     struct_constructors: &mut FxHashMap<LocalDefId, LocalDefId>,
     id: hir::ItemId,
 ) {
-    let allow_dead_code = has_allow_dead_code_or_lang_attr(tcx, id.hir_id());
+    let allow_dead_code = has_allow_dead_code_or_lang_attr(tcx, id.owner_id.def_id);
     if allow_dead_code {
         worklist.push(id.owner_id.def_id);
     }
@@ -548,9 +541,7 @@ fn check_item<'tcx>(
 
             // And we access the Map here to get HirId from LocalDefId
             for id in local_def_ids {
-                if of_trait.is_some()
-                    || has_allow_dead_code_or_lang_attr(tcx, tcx.hir().local_def_id_to_hir_id(id))
-                {
+                if of_trait.is_some() || has_allow_dead_code_or_lang_attr(tcx, id) {
                     worklist.push(id);
                 }
             }
@@ -558,9 +549,9 @@ fn check_item<'tcx>(
         DefKind::Struct => {
             let item = tcx.hir().item(id);
             if let hir::ItemKind::Struct(ref variant_data, _) = item.kind
-                && let Some(ctor_hir_id) = variant_data.ctor_hir_id()
+                && let Some(ctor_def_id) = variant_data.ctor_def_id()
             {
-                struct_constructors.insert(tcx.hir().local_def_id(ctor_hir_id), item.owner_id.def_id);
+                struct_constructors.insert(ctor_def_id, item.owner_id.def_id);
             }
         }
         DefKind::GlobalAsm => {
@@ -576,7 +567,7 @@ fn check_trait_item(tcx: TyCtxt<'_>, worklist: &mut Vec<LocalDefId>, id: hir::Tr
     if matches!(tcx.def_kind(id.owner_id), DefKind::AssocConst | DefKind::AssocFn) {
         let trait_item = tcx.hir().trait_item(id);
         if matches!(trait_item.kind, Const(_, Some(_)) | Fn(_, hir::TraitFn::Provided(_)))
-            && has_allow_dead_code_or_lang_attr(tcx, trait_item.hir_id())
+            && has_allow_dead_code_or_lang_attr(tcx, trait_item.owner_id.def_id)
         {
             worklist.push(trait_item.owner_id.def_id);
         }
@@ -585,7 +576,7 @@ fn check_trait_item(tcx: TyCtxt<'_>, worklist: &mut Vec<LocalDefId>, id: hir::Tr
 
 fn check_foreign_item(tcx: TyCtxt<'_>, worklist: &mut Vec<LocalDefId>, id: hir::ForeignItemId) {
     if matches!(tcx.def_kind(id.owner_id), DefKind::Static(_) | DefKind::Fn)
-        && has_allow_dead_code_or_lang_attr(tcx, id.hir_id())
+        && has_allow_dead_code_or_lang_attr(tcx, id.owner_id.def_id)
     {
         worklist.push(id.owner_id.def_id);
     }
@@ -806,8 +797,7 @@ impl<'tcx> DeadVisitor<'tcx> {
         if self.live_symbols.contains(&def_id) {
             return;
         }
-        let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
-        if has_allow_dead_code_or_lang_attr(self.tcx, hir_id) {
+        if has_allow_dead_code_or_lang_attr(self.tcx, def_id) {
             return;
         }
         let Some(name) = self.tcx.opt_item_name(def_id.to_def_id()) else {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 9c6519ea4bb..9e05ad22e62 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -12,6 +12,7 @@ use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::{MainDefinition, Ty};
 use rustc_span::{Span, Symbol, DUMMY_SP};
 
+use crate::check_attr::ProcMacroKind;
 use crate::lang_items::Duplicate;
 
 #[derive(Diagnostic)]
@@ -1515,3 +1516,52 @@ pub struct ChangeFieldsToBeOfUnitType {
     #[suggestion_part(code = "()")]
     pub spans: Vec<Span>,
 }
+
+#[derive(Diagnostic)]
+#[diag(passes_proc_macro_typeerror)]
+#[note]
+pub(crate) struct ProcMacroTypeError<'tcx> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub found: Ty<'tcx>,
+    pub kind: ProcMacroKind,
+    pub expected_signature: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_proc_macro_diff_arg_count)]
+pub(crate) struct ProcMacroDiffArguments {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub count: usize,
+    pub kind: ProcMacroKind,
+    pub expected_signature: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_proc_macro_missing_args)]
+pub(crate) struct ProcMacroMissingArguments {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub expected_input_count: usize,
+    pub kind: ProcMacroKind,
+    pub expected_signature: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_proc_macro_invalid_abi)]
+pub(crate) struct ProcMacroInvalidAbi {
+    #[primary_span]
+    pub span: Span,
+    pub abi: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_proc_macro_unsafe)]
+pub(crate) struct ProcMacroUnsafe {
+    #[primary_span]
+    pub span: Span,
+}
diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index b86d2316820..51a19c8e3c0 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -12,6 +12,7 @@ use rustc_hir::HirId;
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::util::common::to_readable_str;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
@@ -363,7 +364,7 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
         fd: &'v hir::FnDecl<'v>,
         b: hir::BodyId,
         _: Span,
-        id: hir::HirId,
+        id: LocalDefId,
     ) {
         self.record("FnDecl", Id::None, fd);
         hir_visit::walk_fn(self, fk, fd, b, id)
@@ -567,7 +568,7 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
                 Box, Array, ConstBlock, Call, MethodCall, Tup, Binary, Unary, Lit, Cast, Type, Let,
                 If, While, ForLoop, Loop, Match, Closure, Block, Async, Await, TryBlock, Assign,
                 AssignOp, Field, Index, Range, Underscore, Path, AddrOf, Break, Continue, Ret,
-                InlineAsm, MacCall, Struct, Repeat, Paren, Try, Yield, Yeet, IncludedBytes, Err
+                InlineAsm, FormatArgs, MacCall, Struct, Repeat, Paren, Try, Yield, Yeet, IncludedBytes, Err
             ]
         );
         ast_visit::walk_expr(self, e)
diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs
index 9a40b847d85..fdd0e5dab70 100644
--- a/compiler/rustc_passes/src/lang_items.rs
+++ b/compiler/rustc_passes/src/lang_items.rs
@@ -15,9 +15,9 @@ use crate::weak_lang_items;
 
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::{extract, GenericRequirement};
-use rustc_hir::{HirId, LangItem, LanguageItems, Target};
+use rustc_hir::{LangItem, LanguageItems, Target};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::cstore::ExternCrate;
 use rustc_span::{symbol::kw::Empty, Span};
@@ -40,13 +40,13 @@ impl<'tcx> LanguageItemCollector<'tcx> {
         LanguageItemCollector { tcx, items: LanguageItems::new() }
     }
 
-    fn check_for_lang(&mut self, actual_target: Target, hir_id: HirId) {
-        let attrs = self.tcx.hir().attrs(hir_id);
+    fn check_for_lang(&mut self, actual_target: Target, def_id: LocalDefId) {
+        let attrs = self.tcx.hir().attrs(self.tcx.hir().local_def_id_to_hir_id(def_id));
         if let Some((name, span)) = extract(&attrs) {
             match LangItem::from_name(name) {
                 // Known lang item with attribute on correct target.
                 Some(lang_item) if actual_target == lang_item.target() => {
-                    self.collect_item_extended(lang_item, hir_id, span);
+                    self.collect_item_extended(lang_item, def_id, span);
                 }
                 // Known lang item with attribute on incorrect target.
                 Some(lang_item) => {
@@ -142,8 +142,7 @@ impl<'tcx> LanguageItemCollector<'tcx> {
 
     // Like collect_item() above, but also checks whether the lang item is declared
     // with the right number of generic arguments.
-    fn collect_item_extended(&mut self, lang_item: LangItem, hir_id: HirId, span: Span) {
-        let item_def_id = self.tcx.hir().local_def_id(hir_id).to_def_id();
+    fn collect_item_extended(&mut self, lang_item: LangItem, item_def_id: LocalDefId, span: Span) {
         let name = lang_item.name();
 
         // Now check whether the lang_item has the expected number of generic
@@ -154,7 +153,8 @@ impl<'tcx> LanguageItemCollector<'tcx> {
         // Some other types like Box and various functions like drop_in_place
         // have minimum requirements.
 
-        if let hir::Node::Item(hir::Item { kind, span: item_span, .. }) = self.tcx.hir().get(hir_id)
+        if let hir::Node::Item(hir::Item { kind, span: item_span, .. }) =
+            self.tcx.hir().get_by_def_id(item_def_id)
         {
             let (actual_num, generics_span) = match kind.generics() {
                 Some(generics) => (generics.params.len(), generics.span),
@@ -191,7 +191,7 @@ impl<'tcx> LanguageItemCollector<'tcx> {
             }
         }
 
-        self.collect_item(lang_item, item_def_id);
+        self.collect_item(lang_item, item_def_id.to_def_id());
     }
 }
 
@@ -211,13 +211,14 @@ fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
     let crate_items = tcx.hir_crate_items(());
 
     for id in crate_items.items() {
-        collector.check_for_lang(Target::from_def_kind(tcx.def_kind(id.owner_id)), id.hir_id());
+        collector
+            .check_for_lang(Target::from_def_kind(tcx.def_kind(id.owner_id)), id.owner_id.def_id);
 
         if matches!(tcx.def_kind(id.owner_id), DefKind::Enum) {
             let item = tcx.hir().item(id);
             if let hir::ItemKind::Enum(def, ..) = &item.kind {
                 for variant in def.variants {
-                    collector.check_for_lang(Target::Variant, variant.hir_id);
+                    collector.check_for_lang(Target::Variant, variant.def_id);
                 }
             }
         }
@@ -226,13 +227,13 @@ fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
     // FIXME: avoid calling trait_item() when possible
     for id in crate_items.trait_items() {
         let item = tcx.hir().trait_item(id);
-        collector.check_for_lang(Target::from_trait_item(item), item.hir_id())
+        collector.check_for_lang(Target::from_trait_item(item), item.owner_id.def_id)
     }
 
     // FIXME: avoid calling impl_item() when possible
     for id in crate_items.impl_items() {
         let item = tcx.hir().impl_item(id);
-        collector.check_for_lang(target_from_impl_item(tcx, item), item.hir_id())
+        collector.check_for_lang(target_from_impl_item(tcx, item), item.owner_id.def_id)
     }
 
     // Extract out the found lang items.
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index 34e1abb78b2..0bde7502e39 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -855,7 +855,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
 /// See issue #94972 for details on why this is a special case
 fn is_unstable_reexport(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
     // Get the LocalDefId so we can lookup the item to check the kind.
-    let Some(def_id) = tcx.hir().opt_local_def_id(id) else { return false; };
+    let Some(owner) = id.as_owner() else { return false; };
+    let def_id = owner.def_id;
 
     let Some(stab) = tcx.stability().local_stability(def_id) else {
         return false;
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 9a5d3cceb91..43552861532 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -18,7 +18,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::intern::Interned;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
+use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{AssocItemKind, HirIdSet, ItemId, Node, PatKind};
 use rustc_middle::bug;
@@ -198,7 +198,8 @@ where
                 // Something like `fn() -> Priv {my_func}` is considered a private type even if
                 // `my_func` is public, so we need to visit signatures.
                 if let ty::FnDef(..) = ty.kind() {
-                    tcx.fn_sig(def_id).visit_with(self)?;
+                    // FIXME: this should probably use `substs` from `FnDef`
+                    tcx.fn_sig(def_id).subst_identity().visit_with(self)?;
                 }
                 // Inherent static methods don't have self type in substs.
                 // Something like `fn() {my_method}` type of the method
@@ -270,7 +271,8 @@ where
             | ty::FnPtr(..)
             | ty::Param(..)
             | ty::Error(_)
-            | ty::GeneratorWitness(..) => {}
+            | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..) => {}
             ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
                 bug!("unexpected type: {:?}", ty)
             }
@@ -1877,7 +1879,7 @@ impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
 
 struct PrivateItemsInPublicInterfacesChecker<'tcx> {
     tcx: TyCtxt<'tcx>,
-    old_error_set_ancestry: LocalDefIdSet,
+    old_error_set_ancestry: HirIdSet,
 }
 
 impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx> {
@@ -1890,7 +1892,9 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx> {
             tcx: self.tcx,
             item_def_id: def_id,
             required_visibility,
-            has_old_errors: self.old_error_set_ancestry.contains(&def_id),
+            has_old_errors: self
+                .old_error_set_ancestry
+                .contains(&self.tcx.hir().local_def_id_to_hir_id(def_id)),
             in_assoc_ty: false,
         }
     }
@@ -2156,15 +2160,7 @@ fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
     }
 
     // Check for private types and traits in public interfaces.
-    let mut checker = PrivateItemsInPublicInterfacesChecker {
-        tcx,
-        // Only definition IDs are ever searched in `old_error_set_ancestry`,
-        // so we can filter away all non-definition IDs at this point.
-        old_error_set_ancestry: old_error_set_ancestry
-            .into_iter()
-            .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
-            .collect(),
-    };
+    let mut checker = PrivateItemsInPublicInterfacesChecker { tcx, old_error_set_ancestry };
 
     for id in tcx.hir().items() {
         checker.check_item(id);
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 6d448433ee6..37beff37c1f 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -227,20 +227,27 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                     && let Some(FnCtxt::Assoc(_)) = fn_kind.ctxt()
                     && let Some(items) = self.diagnostic_metadata.current_impl_items
                     && let Some(item) = items.iter().find(|i| {
-                        if let AssocItemKind::Fn(_) = &i.kind && i.ident.name == item_str.name
+                        if let AssocItemKind::Fn(..) | AssocItemKind::Const(..) = &i.kind
+                            && i.ident.name == item_str.name
                         {
                             debug!(?item_str.name);
                             return true
                         }
                         false
                     })
-                    && let AssocItemKind::Fn(fn_) = &item.kind
                 {
-                    debug!(?fn_);
-                    let self_sugg = if fn_.sig.decl.has_self() { "self." } else { "Self::" };
+                    let self_sugg = match &item.kind {
+                        AssocItemKind::Fn(fn_) if fn_.sig.decl.has_self() => "self.",
+                        _ => "Self::",
+                    };
+
                     Some((
                         item_span.shrink_to_lo(),
-                        "consider using the associated function",
+                        match &item.kind {
+                            AssocItemKind::Fn(..) => "consider using the associated function",
+                            AssocItemKind::Const(..) => "consider using the associated constant",
+                            _ => unreachable!("item kind was filtered above"),
+                        },
                         self_sugg.to_string()
                     ))
                 } else {
diff --git a/compiler/rustc_save_analysis/src/dump_visitor.rs b/compiler/rustc_save_analysis/src/dump_visitor.rs
index a5f09de1c40..3982111e38e 100644
--- a/compiler/rustc_save_analysis/src/dump_visitor.rs
+++ b/compiler/rustc_save_analysis/src/dump_visitor.rs
@@ -211,7 +211,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     None => continue,
                 };
                 if !self.span.filter_generated(ident.span) {
-                    let id = id_from_hir_id(hir_id, &self.save_ctxt);
+                    let id = id_from_hir_id(hir_id);
                     let span = self.span_from_span(ident.span);
 
                     self.dumper.dump_def(
@@ -240,17 +240,17 @@ impl<'tcx> DumpVisitor<'tcx> {
         &mut self,
         sig: &'tcx hir::FnSig<'tcx>,
         body: Option<hir::BodyId>,
-        def_id: LocalDefId,
+        owner_id: hir::OwnerId,
         ident: Ident,
         generics: &'tcx hir::Generics<'tcx>,
         span: Span,
     ) {
-        debug!("process_method: {:?}:{}", def_id, ident);
+        debug!("process_method: {:?}:{}", owner_id, ident);
 
         let map = self.tcx.hir();
-        let hir_id = map.local_def_id_to_hir_id(def_id);
-        self.nest_typeck_results(def_id, |v| {
-            if let Some(mut method_data) = v.save_ctxt.get_method_data(hir_id, ident, span) {
+        let hir_id: hir::HirId = owner_id.into();
+        self.nest_typeck_results(owner_id.def_id, |v| {
+            if let Some(mut method_data) = v.save_ctxt.get_method_data(owner_id, ident, span) {
                 if let Some(body) = body {
                     v.process_formals(map.body(body).params, &method_data.qualname);
                 }
@@ -258,9 +258,10 @@ impl<'tcx> DumpVisitor<'tcx> {
 
                 method_data.value =
                     fn_to_string(sig.decl, sig.header, Some(ident.name), generics, &[], None);
-                method_data.sig = sig::method_signature(hir_id, ident, generics, sig, &v.save_ctxt);
+                method_data.sig =
+                    sig::method_signature(owner_id, ident, generics, sig, &v.save_ctxt);
 
-                v.dumper.dump_def(&access_from!(v.save_ctxt, def_id), method_data);
+                v.dumper.dump_def(&access_from!(v.save_ctxt, owner_id.def_id), method_data);
             }
 
             // walk arg and return types
@@ -282,14 +283,11 @@ impl<'tcx> DumpVisitor<'tcx> {
     fn process_struct_field_def(
         &mut self,
         field: &'tcx hir::FieldDef<'tcx>,
-        parent_id: hir::HirId,
+        parent_id: LocalDefId,
     ) {
         let field_data = self.save_ctxt.get_field_data(field, parent_id);
         if let Some(field_data) = field_data {
-            self.dumper.dump_def(
-                &access_from!(self.save_ctxt, self.tcx.hir().local_def_id(field.hir_id)),
-                field_data,
-            );
+            self.dumper.dump_def(&access_from!(self.save_ctxt, field.def_id), field_data);
         }
     }
 
@@ -309,7 +307,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     // Append $id to name to make sure each one is unique.
                     let qualname = format!("{}::{}${}", prefix, name, id);
                     if !self.span.filter_generated(param_ss) {
-                        let id = id_from_hir_id(param.hir_id, &self.save_ctxt);
+                        let id = id_from_def_id(param.def_id.to_def_id());
                         let span = self.span_from_span(param_ss);
 
                         self.dumper.dump_def(
@@ -387,25 +385,24 @@ impl<'tcx> DumpVisitor<'tcx> {
 
     fn process_assoc_const(
         &mut self,
-        def_id: LocalDefId,
+        owner_id: hir::OwnerId,
         ident: Ident,
         typ: &'tcx hir::Ty<'tcx>,
         expr: Option<&'tcx hir::Expr<'tcx>>,
         parent_id: DefId,
         attrs: &'tcx [ast::Attribute],
     ) {
-        let qualname = format!("::{}", self.tcx.def_path_str(def_id.to_def_id()));
+        let qualname = format!("::{}", self.tcx.def_path_str(owner_id.to_def_id()));
 
         if !self.span.filter_generated(ident.span) {
-            let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
-            let sig = sig::assoc_const_signature(hir_id, ident.name, typ, expr, &self.save_ctxt);
+            let sig = sig::assoc_const_signature(owner_id, ident.name, typ, expr, &self.save_ctxt);
             let span = self.span_from_span(ident.span);
 
             self.dumper.dump_def(
-                &access_from!(self.save_ctxt, def_id),
+                &access_from!(self.save_ctxt, owner_id.def_id),
                 Def {
                     kind: DefKind::Const,
-                    id: id_from_hir_id(hir_id, &self.save_ctxt),
+                    id: id_from_def_id(owner_id.to_def_id()),
                     span,
                     name: ident.name.to_string(),
                     qualname,
@@ -421,7 +418,7 @@ impl<'tcx> DumpVisitor<'tcx> {
         }
 
         // walk type and init value
-        self.nest_typeck_results(def_id, |v| {
+        self.nest_typeck_results(owner_id.def_id, |v| {
             v.visit_ty(typ);
             if let Some(expr) = expr {
                 v.visit_expr(expr);
@@ -456,8 +453,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                         if include_priv_fields {
                             return Some(f.ident.to_string());
                         }
-                        let def_id = self.save_ctxt.tcx.hir().local_def_id(f.hir_id);
-                        if self.save_ctxt.tcx.visibility(def_id).is_public() {
+                        if self.save_ctxt.tcx.visibility(f.def_id).is_public() {
                             Some(f.ident.to_string())
                         } else {
                             None
@@ -466,7 +462,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     .collect::<Vec<_>>()
                     .join(", ");
                 let value = format!("{} {{ {} }}", name, fields_str);
-                (value, fields.iter().map(|f| id_from_hir_id(f.hir_id, &self.save_ctxt)).collect())
+                (value, fields.iter().map(|f| id_from_def_id(f.def_id.to_def_id())).collect())
             }
             _ => (String::new(), vec![]),
         };
@@ -495,7 +491,7 @@ impl<'tcx> DumpVisitor<'tcx> {
 
         self.nest_typeck_results(item.owner_id.def_id, |v| {
             for field in def.fields() {
-                v.process_struct_field_def(field, item.hir_id());
+                v.process_struct_field_def(field, item.owner_id.def_id);
                 v.visit_ty(&field.ty);
             }
 
@@ -529,7 +525,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     let value = format!("{}::{} {{ {} }}", enum_data.name, name, fields_str);
                     if !self.span.filter_generated(name_span) {
                         let span = self.span_from_span(name_span);
-                        let id = id_from_hir_id(variant.hir_id, &self.save_ctxt);
+                        let id = id_from_def_id(variant.def_id.to_def_id());
                         let parent = Some(id_from_def_id(item.owner_id.to_def_id()));
                         let attrs = self.tcx.hir().attrs(variant.hir_id);
 
@@ -567,7 +563,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     }
                     if !self.span.filter_generated(name_span) {
                         let span = self.span_from_span(name_span);
-                        let id = id_from_hir_id(variant.hir_id, &self.save_ctxt);
+                        let id = id_from_def_id(variant.def_id.to_def_id());
                         let parent = Some(id_from_def_id(item.owner_id.to_def_id()));
                         let attrs = self.tcx.hir().attrs(variant.hir_id);
 
@@ -593,7 +589,7 @@ impl<'tcx> DumpVisitor<'tcx> {
             }
 
             for field in variant.data.fields() {
-                self.process_struct_field_def(field, variant.hir_id);
+                self.process_struct_field_def(field, variant.def_id);
                 self.visit_ty(field.ty);
             }
         }
@@ -883,7 +879,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                     // Rust uses the id of the pattern for var lookups, so we'll use it too.
                     if !self.span.filter_generated(ident.span) {
                         let qualname = format!("{}${}", ident, hir_id);
-                        let id = id_from_hir_id(hir_id, &self.save_ctxt);
+                        let id = id_from_hir_id(hir_id);
                         let span = self.span_from_span(ident.span);
 
                         self.dumper.dump_def(
@@ -983,7 +979,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                 let body = body.map(|b| self.tcx.hir().body(b).value);
                 let attrs = self.tcx.hir().attrs(trait_item.hir_id());
                 self.process_assoc_const(
-                    trait_item.owner_id.def_id,
+                    trait_item.owner_id,
                     trait_item.ident,
                     &ty,
                     body,
@@ -997,7 +993,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                 self.process_method(
                     sig,
                     body,
-                    trait_item.owner_id.def_id,
+                    trait_item.owner_id,
                     trait_item.ident,
                     &trait_item.generics,
                     trait_item.span,
@@ -1028,7 +1024,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                             decl_id: None,
                             docs: self.save_ctxt.docs_for_attrs(attrs),
                             sig: sig::assoc_type_signature(
-                                trait_item.hir_id(),
+                                trait_item.owner_id,
                                 trait_item.ident,
                                 Some(bounds),
                                 default_ty.as_deref(),
@@ -1053,7 +1049,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                 let body = self.tcx.hir().body(body);
                 let attrs = self.tcx.hir().attrs(impl_item.hir_id());
                 self.process_assoc_const(
-                    impl_item.owner_id.def_id,
+                    impl_item.owner_id,
                     impl_item.ident,
                     &ty,
                     Some(&body.value),
@@ -1065,7 +1061,7 @@ impl<'tcx> DumpVisitor<'tcx> {
                 self.process_method(
                     sig,
                     Some(body),
-                    impl_item.owner_id.def_id,
+                    impl_item.owner_id,
                     impl_item.ident,
                     &impl_item.generics,
                     impl_item.span,
@@ -1081,18 +1077,16 @@ impl<'tcx> DumpVisitor<'tcx> {
     }
 
     pub(crate) fn process_crate(&mut self) {
-        let id = hir::CRATE_HIR_ID;
-        let qualname =
-            format!("::{}", self.tcx.def_path_str(self.tcx.hir().local_def_id(id).to_def_id()));
+        let qualname = format!("::{}", self.tcx.def_path_str(CRATE_DEF_ID.to_def_id()));
 
         let sm = self.tcx.sess.source_map();
         let krate_mod = self.tcx.hir().root_module();
         let filename = sm.span_to_filename(krate_mod.spans.inner_span);
-        let data_id = id_from_hir_id(id, &self.save_ctxt);
+        let data_id = id_from_def_id(CRATE_DEF_ID.to_def_id());
         let children =
             krate_mod.item_ids.iter().map(|i| id_from_def_id(i.owner_id.to_def_id())).collect();
         let span = self.span_from_span(krate_mod.spans.inner_span);
-        let attrs = self.tcx.hir().attrs(id);
+        let attrs = self.tcx.hir().attrs(hir::CRATE_HIR_ID);
 
         self.dumper.dump_def(
             &Access { public: true, reachable: true },
@@ -1319,7 +1313,7 @@ impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
                     // output the inferred type here? :shrug:
                     hir::ArrayLen::Infer(..) => {}
                     hir::ArrayLen::Body(anon_const) => self
-                        .nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
+                        .nest_typeck_results(anon_const.def_id, |v| {
                             v.visit_expr(&map.body(anon_const.body).value)
                         }),
                 }
@@ -1361,7 +1355,7 @@ impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
                     }
                 }
             }
-            hir::ExprKind::Closure(&hir::Closure { ref fn_decl, body, .. }) => {
+            hir::ExprKind::Closure(&hir::Closure { ref fn_decl, body, def_id, .. }) => {
                 let id = format!("${}", ex.hir_id);
 
                 // walk arg and return types
@@ -1375,7 +1369,7 @@ impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
 
                 // walk the body
                 let map = self.tcx.hir();
-                self.nest_typeck_results(self.tcx.hir().local_def_id(ex.hir_id), |v| {
+                self.nest_typeck_results(def_id, |v| {
                     let body = map.body(body);
                     v.process_formals(body.params, &id);
                     v.visit_expr(&body.value)
@@ -1389,7 +1383,7 @@ impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
                     // output the inferred type here? :shrug:
                     hir::ArrayLen::Infer(..) => {}
                     hir::ArrayLen::Body(anon_const) => self
-                        .nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
+                        .nest_typeck_results(anon_const.def_id, |v| {
                             v.visit_expr(&map.body(anon_const.body).value)
                         }),
                 }
diff --git a/compiler/rustc_save_analysis/src/lib.rs b/compiler/rustc_save_analysis/src/lib.rs
index a8d82de02b7..a9a92cc4f62 100644
--- a/compiler/rustc_save_analysis/src/lib.rs
+++ b/compiler/rustc_save_analysis/src/lib.rs
@@ -21,7 +21,7 @@ use rustc_ast::util::comments::beautify_doc_string;
 use rustc_ast_pretty::pprust::attribute_to_string;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind as HirDefKind, Res};
-use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::Node;
 use rustc_hir_pretty::{enum_def_to_string, fn_to_string, ty_to_string};
@@ -318,7 +318,7 @@ impl<'tcx> SaveContext<'tcx> {
                     qualname,
                     value,
                     parent: None,
-                    children: def.variants.iter().map(|v| id_from_hir_id(v.hir_id, self)).collect(),
+                    children: def.variants.iter().map(|v| id_from_def_id(v.def_id.to_def_id())).collect(),
                     decl_id: None,
                     docs: self.docs_for_attrs(attrs),
                     sig: sig::item_signature(item, self),
@@ -379,12 +379,11 @@ impl<'tcx> SaveContext<'tcx> {
         }
     }
 
-    pub fn get_field_data(&self, field: &hir::FieldDef<'_>, scope: hir::HirId) -> Option<Def> {
+    pub fn get_field_data(&self, field: &hir::FieldDef<'_>, scope: LocalDefId) -> Option<Def> {
         let name = field.ident.to_string();
-        let scope_def_id = self.tcx.hir().local_def_id(scope).to_def_id();
-        let qualname = format!("::{}::{}", self.tcx.def_path_str(scope_def_id), field.ident);
+        let qualname = format!("::{}::{}", self.tcx.def_path_str(scope.to_def_id()), field.ident);
         filter!(self.span_utils, field.ident.span);
-        let field_def_id = self.tcx.hir().local_def_id(field.hir_id).to_def_id();
+        let field_def_id = field.def_id.to_def_id();
         let typ = self.tcx.type_of(field_def_id).to_string();
 
         let id = id_from_def_id(field_def_id);
@@ -398,7 +397,7 @@ impl<'tcx> SaveContext<'tcx> {
             name,
             qualname,
             value: typ,
-            parent: Some(id_from_def_id(scope_def_id)),
+            parent: Some(id_from_def_id(scope.to_def_id())),
             children: vec![],
             decl_id: None,
             docs: self.docs_for_attrs(attrs),
@@ -409,12 +408,11 @@ impl<'tcx> SaveContext<'tcx> {
 
     // FIXME would be nice to take a MethodItem here, but the ast provides both
     // trait and impl flavours, so the caller must do the disassembly.
-    pub fn get_method_data(&self, hir_id: hir::HirId, ident: Ident, span: Span) -> Option<Def> {
+    pub fn get_method_data(&self, owner_id: hir::OwnerId, ident: Ident, span: Span) -> Option<Def> {
         // The qualname for a method is the trait name or name of the struct in an impl in
         // which the method is declared in, followed by the method's name.
-        let def_id = self.tcx.hir().local_def_id(hir_id).to_def_id();
         let (qualname, parent_scope, decl_id, docs, attributes) =
-            match self.tcx.impl_of_method(def_id) {
+            match self.tcx.impl_of_method(owner_id.to_def_id()) {
                 Some(impl_id) => match self.tcx.hir().get_if_local(impl_id) {
                     Some(Node::Item(item)) => match item.kind {
                         hir::ItemKind::Impl(hir::Impl { ref self_ty, .. }) => {
@@ -427,8 +425,8 @@ impl<'tcx> SaveContext<'tcx> {
                             let trait_id = self.tcx.trait_id_of_impl(impl_id);
                             let mut docs = String::new();
                             let mut attrs = vec![];
-                            if let Some(Node::ImplItem(_)) = hir.find(hir_id) {
-                                attrs = self.tcx.hir().attrs(hir_id).to_vec();
+                            if let Some(Node::ImplItem(_)) = hir.find(owner_id.into()) {
+                                attrs = self.tcx.hir().attrs(owner_id.into()).to_vec();
                                 docs = self.docs_for_attrs(&attrs);
                             }
 
@@ -452,29 +450,29 @@ impl<'tcx> SaveContext<'tcx> {
                         _ => {
                             span_bug!(
                                 span,
-                                "Container {:?} for method {} not an impl?",
+                                "Container {:?} for method {:?} not an impl?",
                                 impl_id,
-                                hir_id
+                                owner_id,
                             );
                         }
                     },
                     r => {
                         span_bug!(
                             span,
-                            "Container {:?} for method {} is not a node item {:?}",
+                            "Container {:?} for method {:?} is not a node item {:?}",
                             impl_id,
-                            hir_id,
+                            owner_id,
                             r
                         );
                     }
                 },
-                None => match self.tcx.trait_of_item(def_id) {
+                None => match self.tcx.trait_of_item(owner_id.to_def_id()) {
                     Some(def_id) => {
                         let mut docs = String::new();
                         let mut attrs = vec![];
 
-                        if let Some(Node::TraitItem(_)) = self.tcx.hir().find(hir_id) {
-                            attrs = self.tcx.hir().attrs(hir_id).to_vec();
+                        if let Some(Node::TraitItem(_)) = self.tcx.hir().find(owner_id.into()) {
+                            attrs = self.tcx.hir().attrs(owner_id.into()).to_vec();
                             docs = self.docs_for_attrs(&attrs);
                         }
 
@@ -487,7 +485,7 @@ impl<'tcx> SaveContext<'tcx> {
                         )
                     }
                     None => {
-                        debug!("could not find container for method {} at {:?}", hir_id, span);
+                        debug!("could not find container for method {:?} at {:?}", owner_id, span);
                         // This is not necessarily a bug, if there was a compilation error,
                         // the typeck results we need might not exist.
                         return None;
@@ -501,7 +499,7 @@ impl<'tcx> SaveContext<'tcx> {
 
         Some(Def {
             kind: DefKind::Method,
-            id: id_from_def_id(def_id),
+            id: id_from_def_id(owner_id.to_def_id()),
             span: self.span_from_span(ident.span),
             name: ident.name.to_string(),
             qualname,
@@ -669,7 +667,7 @@ impl<'tcx> SaveContext<'tcx> {
 
         match res {
             Res::Local(id) => {
-                Some(Ref { kind: RefKind::Variable, span, ref_id: id_from_hir_id(id, self) })
+                Some(Ref { kind: RefKind::Variable, span, ref_id: id_from_hir_id(id) })
             }
             Res::Def(HirDefKind::Trait, def_id) if fn_type(path_seg) => {
                 Some(Ref { kind: RefKind::Type, span, ref_id: id_from_def_id(def_id) })
@@ -1033,18 +1031,15 @@ fn id_from_def_id(id: DefId) -> rls_data::Id {
     rls_data::Id { krate: id.krate.as_u32(), index: id.index.as_u32() }
 }
 
-fn id_from_hir_id(id: hir::HirId, scx: &SaveContext<'_>) -> rls_data::Id {
-    let def_id = scx.tcx.hir().opt_local_def_id(id);
-    def_id.map(|id| id_from_def_id(id.to_def_id())).unwrap_or_else(|| {
-        // Create a *fake* `DefId` out of a `HirId` by combining the owner
-        // `local_def_index` and the `local_id`.
-        // This will work unless you have *billions* of definitions in a single
-        // crate (very unlikely to actually happen).
-        rls_data::Id {
-            krate: LOCAL_CRATE.as_u32(),
-            index: id.owner.def_id.local_def_index.as_u32() | id.local_id.as_u32().reverse_bits(),
-        }
-    })
+fn id_from_hir_id(id: hir::HirId) -> rls_data::Id {
+    // Create a *fake* `DefId` out of a `HirId` by combining the owner
+    // `local_def_index` and the `local_id`.
+    // This will work unless you have *billions* of definitions in a single
+    // crate (very unlikely to actually happen).
+    rls_data::Id {
+        krate: LOCAL_CRATE.as_u32(),
+        index: id.owner.def_id.local_def_index.as_u32() | id.local_id.as_u32().reverse_bits(),
+    }
 }
 
 fn null_id() -> rls_data::Id {
diff --git a/compiler/rustc_save_analysis/src/sig.rs b/compiler/rustc_save_analysis/src/sig.rs
index 5a1bcb8fdc8..979305547c1 100644
--- a/compiler/rustc_save_analysis/src/sig.rs
+++ b/compiler/rustc_save_analysis/src/sig.rs
@@ -25,7 +25,7 @@
 //
 // FIXME where clauses need implementing, defs/refs in generics are mostly missing.
 
-use crate::{id_from_def_id, id_from_hir_id, SaveContext};
+use crate::{id_from_def_id, SaveContext};
 
 use rls_data::{SigElement, Signature};
 
@@ -34,6 +34,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir_pretty::id_to_string;
 use rustc_hir_pretty::{bounds_to_string, path_segment_to_string, path_to_string, ty_to_string};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{Ident, Symbol};
 
 pub fn item_signature(item: &hir::Item<'_>, scx: &SaveContext<'_>) -> Option<Signature> {
@@ -71,7 +72,7 @@ pub fn variant_signature(variant: &hir::Variant<'_>, scx: &SaveContext<'_>) -> O
 }
 
 pub fn method_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Ident,
     generics: &hir::Generics<'_>,
     m: &hir::FnSig<'_>,
@@ -84,7 +85,7 @@ pub fn method_signature(
 }
 
 pub fn assoc_const_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Symbol,
     ty: &hir::Ty<'_>,
     default: Option<&hir::Expr<'_>>,
@@ -97,7 +98,7 @@ pub fn assoc_const_signature(
 }
 
 pub fn assoc_type_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Ident,
     bounds: Option<hir::GenericBounds<'_>>,
     default: Option<&hir::Ty<'_>>,
@@ -112,7 +113,8 @@ pub fn assoc_type_signature(
 type Result = std::result::Result<Signature, &'static str>;
 
 trait Sig {
-    fn make(&self, offset: usize, id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result;
+    type Parent;
+    fn make(&self, offset: usize, id: Option<Self::Parent>, scx: &SaveContext<'_>) -> Result;
 }
 
 fn extend_sig(
@@ -148,6 +150,7 @@ fn text_sig(text: String) -> Signature {
 }
 
 impl<'hir> Sig for hir::Ty<'hir> {
+    type Parent = hir::HirId;
     fn make(&self, offset: usize, _parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
         let id = Some(self.hir_id);
         match self.kind {
@@ -326,6 +329,7 @@ impl<'hir> Sig for hir::Ty<'hir> {
 }
 
 impl<'hir> Sig for hir::Item<'hir> {
+    type Parent = hir::HirId;
     fn make(&self, offset: usize, _parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
         let id = Some(self.hir_id());
 
@@ -391,7 +395,7 @@ impl<'hir> Sig for hir::Item<'hir> {
                 text.push_str("fn ");
 
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
 
                 sig.text.push('(');
                 for i in decl.inputs {
@@ -441,7 +445,7 @@ impl<'hir> Sig for hir::Item<'hir> {
             hir::ItemKind::TyAlias(ref ty, ref generics) => {
                 let text = "type ".to_owned();
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
 
                 sig.text.push_str(" = ");
                 let ty = ty.make(offset + sig.text.len(), id, scx)?;
@@ -453,21 +457,21 @@ impl<'hir> Sig for hir::Item<'hir> {
             hir::ItemKind::Enum(_, ref generics) => {
                 let text = "enum ".to_owned();
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
                 sig.text.push_str(" {}");
                 Ok(sig)
             }
             hir::ItemKind::Struct(_, ref generics) => {
                 let text = "struct ".to_owned();
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
                 sig.text.push_str(" {}");
                 Ok(sig)
             }
             hir::ItemKind::Union(_, ref generics) => {
                 let text = "union ".to_owned();
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
                 sig.text.push_str(" {}");
                 Ok(sig)
             }
@@ -483,7 +487,7 @@ impl<'hir> Sig for hir::Item<'hir> {
                 }
                 text.push_str("trait ");
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
 
                 if !bounds.is_empty() {
                     sig.text.push_str(": ");
@@ -498,7 +502,7 @@ impl<'hir> Sig for hir::Item<'hir> {
                 let mut text = String::new();
                 text.push_str("trait ");
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
 
                 if !bounds.is_empty() {
                     sig.text.push_str(" = ");
@@ -532,7 +536,8 @@ impl<'hir> Sig for hir::Item<'hir> {
                     text.push_str(" const");
                 }
 
-                let generics_sig = generics.make(offset + text.len(), id, scx)?;
+                let generics_sig =
+                    generics.make(offset + text.len(), Some(self.owner_id.def_id), scx)?;
                 text.push_str(&generics_sig.text);
 
                 text.push(' ');
@@ -575,6 +580,7 @@ impl<'hir> Sig for hir::Item<'hir> {
 }
 
 impl<'hir> Sig for hir::Path<'hir> {
+    type Parent = hir::HirId;
     fn make(&self, offset: usize, id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
         let res = scx.get_path_res(id.ok_or("Missing id for Path")?);
 
@@ -609,7 +615,8 @@ impl<'hir> Sig for hir::Path<'hir> {
 
 // This does not cover the where clause, which must be processed separately.
 impl<'hir> Sig for hir::Generics<'hir> {
-    fn make(&self, offset: usize, _parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
+    type Parent = LocalDefId;
+    fn make(&self, offset: usize, _parent_id: Option<LocalDefId>, scx: &SaveContext<'_>) -> Result {
         if self.params.is_empty() {
             return Ok(text_sig(String::new()));
         }
@@ -624,7 +631,7 @@ impl<'hir> Sig for hir::Generics<'hir> {
             }
             param_text.push_str(param.name.ident().as_str());
             defs.push(SigElement {
-                id: id_from_hir_id(param.hir_id, scx),
+                id: id_from_def_id(param.def_id.to_def_id()),
                 start: offset + text.len(),
                 end: offset + text.len() + param_text.as_str().len(),
             });
@@ -646,12 +653,13 @@ impl<'hir> Sig for hir::Generics<'hir> {
 }
 
 impl<'hir> Sig for hir::FieldDef<'hir> {
-    fn make(&self, offset: usize, _parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
+    type Parent = LocalDefId;
+    fn make(&self, offset: usize, _parent_id: Option<LocalDefId>, scx: &SaveContext<'_>) -> Result {
         let mut text = String::new();
 
         text.push_str(&self.ident.to_string());
         let defs = Some(SigElement {
-            id: id_from_hir_id(self.hir_id, scx),
+            id: id_from_def_id(self.def_id.to_def_id()),
             start: offset,
             end: offset + text.len(),
         });
@@ -666,13 +674,14 @@ impl<'hir> Sig for hir::FieldDef<'hir> {
 }
 
 impl<'hir> Sig for hir::Variant<'hir> {
-    fn make(&self, offset: usize, parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
+    type Parent = LocalDefId;
+    fn make(&self, offset: usize, parent_id: Option<LocalDefId>, scx: &SaveContext<'_>) -> Result {
         let mut text = self.ident.to_string();
         match self.data {
             hir::VariantData::Struct(fields, r) => {
                 let id = parent_id.ok_or("Missing id for Variant's parent")?;
                 let name_def = SigElement {
-                    id: id_from_hir_id(id, scx),
+                    id: id_from_def_id(id.to_def_id()),
                     start: offset,
                     end: offset + text.len(),
                 };
@@ -693,9 +702,9 @@ impl<'hir> Sig for hir::Variant<'hir> {
                 text.push('}');
                 Ok(Signature { text, defs, refs })
             }
-            hir::VariantData::Tuple(fields, id, _) => {
+            hir::VariantData::Tuple(fields, _, def_id) => {
                 let name_def = SigElement {
-                    id: id_from_hir_id(id, scx),
+                    id: id_from_def_id(def_id.to_def_id()),
                     start: offset,
                     end: offset + text.len(),
                 };
@@ -703,7 +712,7 @@ impl<'hir> Sig for hir::Variant<'hir> {
                 let mut defs = vec![name_def];
                 let mut refs = vec![];
                 for f in fields {
-                    let field_sig = f.make(offset + text.len(), Some(id), scx)?;
+                    let field_sig = f.make(offset + text.len(), Some(def_id), scx)?;
                     text.push_str(&field_sig.text);
                     text.push_str(", ");
                     defs.extend(field_sig.defs.into_iter());
@@ -712,9 +721,9 @@ impl<'hir> Sig for hir::Variant<'hir> {
                 text.push(')');
                 Ok(Signature { text, defs, refs })
             }
-            hir::VariantData::Unit(id, _) => {
+            hir::VariantData::Unit(_, def_id) => {
                 let name_def = SigElement {
-                    id: id_from_hir_id(id, scx),
+                    id: id_from_def_id(def_id.to_def_id()),
                     start: offset,
                     end: offset + text.len(),
                 };
@@ -725,6 +734,7 @@ impl<'hir> Sig for hir::Variant<'hir> {
 }
 
 impl<'hir> Sig for hir::ForeignItem<'hir> {
+    type Parent = hir::HirId;
     fn make(&self, offset: usize, _parent_id: Option<hir::HirId>, scx: &SaveContext<'_>) -> Result {
         let id = Some(self.hir_id());
         match self.kind {
@@ -733,7 +743,7 @@ impl<'hir> Sig for hir::ForeignItem<'hir> {
                 text.push_str("fn ");
 
                 let mut sig =
-                    name_and_generics(text, offset, generics, self.hir_id(), self.ident, scx)?;
+                    name_and_generics(text, offset, generics, self.owner_id, self.ident, scx)?;
 
                 sig.text.push('(');
                 for i in decl.inputs {
@@ -797,25 +807,25 @@ fn name_and_generics(
     mut text: String,
     offset: usize,
     generics: &hir::Generics<'_>,
-    id: hir::HirId,
+    id: hir::OwnerId,
     name: Ident,
     scx: &SaveContext<'_>,
 ) -> Result {
     let name = name.to_string();
     let def = SigElement {
-        id: id_from_hir_id(id, scx),
+        id: id_from_def_id(id.to_def_id()),
         start: offset + text.len(),
         end: offset + text.len() + name.len(),
     };
     text.push_str(&name);
-    let generics: Signature = generics.make(offset + text.len(), Some(id), scx)?;
+    let generics: Signature = generics.make(offset + text.len(), Some(id.def_id), scx)?;
     // FIXME where clause
     let text = format!("{}{}", text, generics.text);
     Ok(extend_sig(generics, text, vec![def], vec![]))
 }
 
 fn make_assoc_type_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Ident,
     bounds: Option<hir::GenericBounds<'_>>,
     default: Option<&hir::Ty<'_>>,
@@ -824,7 +834,7 @@ fn make_assoc_type_signature(
     let mut text = "type ".to_owned();
     let name = ident.to_string();
     let mut defs = vec![SigElement {
-        id: id_from_hir_id(id, scx),
+        id: id_from_def_id(id.to_def_id()),
         start: text.len(),
         end: text.len() + name.len(),
     }];
@@ -837,7 +847,7 @@ fn make_assoc_type_signature(
     }
     if let Some(default) = default {
         text.push_str(" = ");
-        let ty_sig = default.make(text.len(), Some(id), scx)?;
+        let ty_sig = default.make(text.len(), Some(id.into()), scx)?;
         text.push_str(&ty_sig.text);
         defs.extend(ty_sig.defs.into_iter());
         refs.extend(ty_sig.refs.into_iter());
@@ -847,7 +857,7 @@ fn make_assoc_type_signature(
 }
 
 fn make_assoc_const_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Symbol,
     ty: &hir::Ty<'_>,
     default: Option<&hir::Expr<'_>>,
@@ -856,7 +866,7 @@ fn make_assoc_const_signature(
     let mut text = "const ".to_owned();
     let name = ident.to_string();
     let mut defs = vec![SigElement {
-        id: id_from_hir_id(id, scx),
+        id: id_from_def_id(id.to_def_id()),
         start: text.len(),
         end: text.len() + name.len(),
     }];
@@ -864,7 +874,7 @@ fn make_assoc_const_signature(
     text.push_str(&name);
     text.push_str(": ");
 
-    let ty_sig = ty.make(text.len(), Some(id), scx)?;
+    let ty_sig = ty.make(text.len(), Some(id.into()), scx)?;
     text.push_str(&ty_sig.text);
     defs.extend(ty_sig.defs.into_iter());
     refs.extend(ty_sig.refs.into_iter());
@@ -878,7 +888,7 @@ fn make_assoc_const_signature(
 }
 
 fn make_method_signature(
-    id: hir::HirId,
+    id: hir::OwnerId,
     ident: Ident,
     generics: &hir::Generics<'_>,
     m: &hir::FnSig<'_>,
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 586454f7657..c49c5fa9904 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -864,18 +864,6 @@ pub enum CrateType {
     ProcMacro,
 }
 
-impl CrateType {
-    /// When generated, is this crate type an archive?
-    pub fn is_archive(&self) -> bool {
-        match *self {
-            CrateType::Rlib | CrateType::Staticlib => true,
-            CrateType::Executable | CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro => {
-                false
-            }
-        }
-    }
-}
-
 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
 pub enum Passes {
     Some(Vec<String>),
@@ -957,6 +945,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
     if sess.target.has_thread_local {
         ret.insert((sym::target_thread_local, None));
     }
+    let mut has_atomic = false;
     for (i, align) in [
         (8, layout.i8_align.abi),
         (16, layout.i16_align.abi),
@@ -965,6 +954,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
         (128, layout.i128_align.abi),
     ] {
         if i >= min_atomic_width && i <= max_atomic_width {
+            has_atomic = true;
             let mut insert_atomic = |s, align: Align| {
                 ret.insert((sym::target_has_atomic_load_store, Some(Symbol::intern(s))));
                 if atomic_cas {
@@ -981,6 +971,12 @@ fn default_configuration(sess: &Session) -> CrateConfig {
             }
         }
     }
+    if sess.is_nightly_build() && has_atomic {
+        ret.insert((sym::target_has_atomic_load_store, None));
+        if atomic_cas {
+            ret.insert((sym::target_has_atomic, None));
+        }
+    }
 
     let panic_strategy = sess.panic_strategy();
     ret.insert((sym::panic, Some(panic_strategy.desc_symbol())));
@@ -2577,6 +2573,7 @@ fn parse_pretty(unstable_opts: &UnstableOptions, efmt: ErrorOutputType) -> Optio
         "hir,typed" => Hir(PpHirMode::Typed),
         "hir-tree" => HirTree,
         "thir-tree" => ThirTree,
+        "thir-flat" => ThirFlat,
         "mir" => Mir,
         "mir-cfg" => MirCFG,
         name => early_error(
@@ -2585,7 +2582,8 @@ fn parse_pretty(unstable_opts: &UnstableOptions, efmt: ErrorOutputType) -> Optio
                 "argument to `unpretty` must be one of `normal`, `identified`, \
                             `expanded`, `expanded,identified`, `expanded,hygiene`, \
                             `ast-tree`, `ast-tree,expanded`, `hir`, `hir,identified`, \
-                            `hir,typed`, `hir-tree`, `thir-tree`, `mir` or `mir-cfg`; got {name}"
+                            `hir,typed`, `hir-tree`, `thir-tree`, `thir-flat`, `mir` or \
+                            `mir-cfg`; got {name}"
             ),
         ),
     };
@@ -2740,6 +2738,8 @@ pub enum PpMode {
     HirTree,
     /// `-Zunpretty=thir-tree`
     ThirTree,
+    /// `-Zunpretty=`thir-flat`
+    ThirFlat,
     /// `-Zunpretty=mir`
     Mir,
     /// `-Zunpretty=mir-cfg`
@@ -2758,6 +2758,7 @@ impl PpMode {
             | Hir(_)
             | HirTree
             | ThirTree
+            | ThirFlat
             | Mir
             | MirCFG => true,
         }
@@ -2767,13 +2768,13 @@ impl PpMode {
         match *self {
             Source(_) | AstTree(_) => false,
 
-            Hir(_) | HirTree | ThirTree | Mir | MirCFG => true,
+            Hir(_) | HirTree | ThirTree | ThirFlat | Mir | MirCFG => true,
         }
     }
 
     pub fn needs_analysis(&self) -> bool {
         use PpMode::*;
-        matches!(*self, Mir | MirCFG | ThirTree)
+        matches!(*self, Mir | MirCFG | ThirTree | ThirFlat)
     }
 }
 
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 7b5fd6cc2a8..0db4d85ff4b 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1290,6 +1290,8 @@ options! {
         (default: no)"),
     drop_tracking: bool = (false, parse_bool, [TRACKED],
         "enables drop tracking in generators (default: no)"),
+    drop_tracking_mir: bool = (false, parse_bool, [TRACKED],
+        "enables drop tracking on MIR in generators (default: no)"),
     dual_proc_macros: bool = (false, parse_bool, [TRACKED],
         "load proc macros for both target and host, but only link to the target (default: no)"),
     dump_dep_graph: bool = (false, parse_bool, [UNTRACKED],
@@ -1616,6 +1618,8 @@ options! {
         "measure time of each LLVM pass (default: no)"),
     time_passes: bool = (false, parse_bool, [UNTRACKED],
         "measure time of each rustc pass (default: no)"),
+    tiny_const_eval_limit: bool = (false, parse_bool, [TRACKED],
+        "sets a tiny, non-configurable limit for const eval; useful for compiler tests"),
     #[rustc_lint_opt_deny_field_access("use `Session::tls_model` instead of this field")]
     tls_model: Option<TlsModel> = (None, parse_tls_model, [TRACKED],
         "choose the TLS model to use (`rustc --print tls-models` for details)"),
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 7597b8d126a..f1119214be4 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -288,6 +288,7 @@ symbols! {
         Target,
         ToOwned,
         ToString,
+        TokenStream,
         Try,
         TryCaptureGeneric,
         TryCapturePrintable,
@@ -723,11 +724,17 @@ symbols! {
         forbid,
         forget,
         format,
+        format_alignment,
         format_args,
         format_args_capture,
         format_args_macro,
         format_args_nl,
+        format_argument,
+        format_arguments,
+        format_count,
         format_macro,
+        format_placeholder,
+        format_unsafe_arg,
         freeze,
         freg,
         frem_fast,
@@ -948,6 +955,7 @@ symbols! {
         mul,
         mul_assign,
         mul_with_overflow,
+        multiple_supertrait_upcastable,
         must_not_suspend,
         must_use,
         naked,
diff --git a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
index 0759b95bd94..c9b4ab0a38d 100644
--- a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
+++ b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
@@ -640,6 +640,7 @@ fn encode_ty<'tcx>(
         ty::Bound(..)
         | ty::Error(..)
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::Infer(..)
         | ty::Alias(..)
         | ty::Param(..)
@@ -793,6 +794,7 @@ fn transform_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, options: TransformTyOptio
         ty::Bound(..)
         | ty::Error(..)
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::Infer(..)
         | ty::Alias(..)
         | ty::Param(..)
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index 0d446d654dc..00d1ff5ceed 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -490,6 +490,7 @@ impl<'tcx> Printer<'tcx> for &mut SymbolMangler<'tcx> {
             }
 
             ty::GeneratorWitness(_) => bug!("symbol_names: unexpected `GeneratorWitness`"),
+            ty::GeneratorWitnessMIR(..) => bug!("symbol_names: unexpected `GeneratorWitnessMIR`"),
         }
 
         // Only cache types that do not refer to an enclosing
diff --git a/compiler/rustc_target/src/abi/call/loongarch.rs b/compiler/rustc_target/src/abi/call/loongarch.rs
index 4a2d39cc700..247256f076b 100644
--- a/compiler/rustc_target/src/abi/call/loongarch.rs
+++ b/compiler/rustc_target/src/abi/call/loongarch.rs
@@ -39,7 +39,7 @@ where
 {
     match arg_layout.abi {
         Abi::Scalar(scalar) => match scalar.primitive() {
-            abi::Int(..) | abi::Pointer => {
+            abi::Int(..) | abi::Pointer(_) => {
                 if arg_layout.size.bits() > xlen {
                     return Err(CannotUseFpConv);
                 }
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index 3b8c867d35b..a0730fbb650 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -346,7 +346,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
             // The primitive for this algorithm.
             Abi::Scalar(scalar) => {
                 let kind = match scalar.primitive() {
-                    abi::Int(..) | abi::Pointer => RegKind::Integer,
+                    abi::Int(..) | abi::Pointer(_) => RegKind::Integer,
                     abi::F32 | abi::F64 => RegKind::Float,
                 };
                 Ok(HomogeneousAggregate::Homogeneous(Reg { kind, size: self.size }))
diff --git a/compiler/rustc_target/src/abi/call/riscv.rs b/compiler/rustc_target/src/abi/call/riscv.rs
index 34280d38e34..d90dce2a087 100644
--- a/compiler/rustc_target/src/abi/call/riscv.rs
+++ b/compiler/rustc_target/src/abi/call/riscv.rs
@@ -45,7 +45,7 @@ where
 {
     match arg_layout.abi {
         Abi::Scalar(scalar) => match scalar.primitive() {
-            abi::Int(..) | abi::Pointer => {
+            abi::Int(..) | abi::Pointer(_) => {
                 if arg_layout.size.bits() > xlen {
                     return Err(CannotUseFpConv);
                 }
diff --git a/compiler/rustc_target/src/abi/call/sparc64.rs b/compiler/rustc_target/src/abi/call/sparc64.rs
index c8b6ac5ae25..cbed5b4afc1 100644
--- a/compiler/rustc_target/src/abi/call/sparc64.rs
+++ b/compiler/rustc_target/src/abi/call/sparc64.rs
@@ -20,7 +20,7 @@ where
 {
     let dl = cx.data_layout();
 
-    if !scalar.primitive().is_float() {
+    if !matches!(scalar.primitive(), abi::F32 | abi::F64) {
         return data;
     }
 
@@ -83,11 +83,11 @@ where
         (abi::F32, _) => offset += Reg::f32().size,
         (_, abi::F64) => offset += Reg::f64().size,
         (abi::Int(i, _signed), _) => offset += i.size(),
-        (abi::Pointer, _) => offset += Reg::i64().size,
+        (abi::Pointer(_), _) => offset += Reg::i64().size,
         _ => {}
     }
 
-    if (offset.bytes() % 4) != 0 && scalar2.primitive().is_float() {
+    if (offset.bytes() % 4) != 0 && matches!(scalar2.primitive(), abi::F32 | abi::F64) {
         offset += Size::from_bytes(4 - (offset.bytes() % 4));
     }
     data = arg_scalar(cx, scalar2, offset, data);
diff --git a/compiler/rustc_target/src/abi/call/x86_64.rs b/compiler/rustc_target/src/abi/call/x86_64.rs
index c0c071a614f..9427f27d1b7 100644
--- a/compiler/rustc_target/src/abi/call/x86_64.rs
+++ b/compiler/rustc_target/src/abi/call/x86_64.rs
@@ -50,7 +50,7 @@ where
             Abi::Uninhabited => return Ok(()),
 
             Abi::Scalar(scalar) => match scalar.primitive() {
-                abi::Int(..) | abi::Pointer => Class::Int,
+                abi::Int(..) | abi::Pointer(_) => Class::Int,
                 abi::F32 | abi::F64 => Class::Sse,
             },
 
diff --git a/compiler/rustc_target/src/abi/mod.rs b/compiler/rustc_target/src/abi/mod.rs
index 88a0a1f8ecf..39761baf1bc 100644
--- a/compiler/rustc_target/src/abi/mod.rs
+++ b/compiler/rustc_target/src/abi/mod.rs
@@ -129,7 +129,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
         C: HasDataLayout,
     {
         match self.abi {
-            Abi::Scalar(scalar) => scalar.primitive().is_float(),
+            Abi::Scalar(scalar) => matches!(scalar.primitive(), F32 | F64),
             Abi::Aggregate { .. } => {
                 if self.fields.count() == 1 && self.fields.offset(0).bytes() == 0 {
                     self.field(cx, 0).is_single_fp_element(cx)
diff --git a/compiler/rustc_target/src/spec/bpf_base.rs b/compiler/rustc_target/src/spec/bpf_base.rs
index 2b00cda44b5..4d03747d016 100644
--- a/compiler/rustc_target/src/spec/bpf_base.rs
+++ b/compiler/rustc_target/src/spec/bpf_base.rs
@@ -6,7 +6,7 @@ pub fn opts(endian: Endian) -> TargetOptions {
         allow_asm: true,
         endian,
         linker_flavor: LinkerFlavor::Bpf,
-        atomic_cas: true,
+        atomic_cas: false,
         dynamic_linking: true,
         no_builtins: true,
         panic_strategy: PanicStrategy::Abort,
diff --git a/compiler/rustc_trait_selection/src/solve/assembly.rs b/compiler/rustc_trait_selection/src/solve/assembly.rs
index cdb72d49834..e44fd82ba22 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly.rs
@@ -1,6 +1,8 @@
 //! Code shared by trait and projection goals for candidate assembly.
 
 use super::infcx_ext::InferCtxtExt;
+#[cfg(doc)]
+use super::trait_goals::structural_traits::*;
 use super::{CanonicalResponse, Certainty, EvalCtxt, Goal, QueryResult};
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::query::NoSolution;
@@ -76,7 +78,7 @@ pub(super) enum CandidateSource {
     ///     let _y = x.clone();
     /// }
     /// ```
-    AliasBound(usize),
+    AliasBound,
 }
 
 pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy + Eq {
@@ -98,41 +100,79 @@ pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy + Eq {
         assumption: ty::Predicate<'tcx>,
     ) -> QueryResult<'tcx>;
 
+    // A type implements an `auto trait` if its components do as well. These components
+    // are given by built-in rules from [`instantiate_constituent_tys_for_auto_trait`].
     fn consider_auto_trait_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
+    // A trait alias holds if the RHS traits and `where` clauses hold.
     fn consider_trait_alias_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
+    // A type is `Copy` or `Clone` if its components are `Sized`. These components
+    // are given by built-in rules from [`instantiate_constituent_tys_for_sized_trait`].
     fn consider_builtin_sized_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
+    // A type is `Copy` or `Clone` if its components are `Copy` or `Clone`. These
+    // components are given by built-in rules from [`instantiate_constituent_tys_for_copy_clone_trait`].
     fn consider_builtin_copy_clone_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
+    // A type is `PointerSized` if we can compute its layout, and that layout
+    // matches the layout of `usize`.
     fn consider_builtin_pointer_sized_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
+    // A callable type (a closure, fn def, or fn ptr) is known to implement the `Fn<A>`
+    // family of traits where `A` is given by the signature of the type.
     fn consider_builtin_fn_trait_candidates(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
         kind: ty::ClosureKind,
     ) -> QueryResult<'tcx>;
 
+    // `Tuple` is implemented if the `Self` type is a tuple.
     fn consider_builtin_tuple_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
+
+    // `Pointee` is always implemented.
+    //
+    // See the projection implementation for the `Metadata` types for all of
+    // the built-in types. For structs, the metadata type is given by the struct
+    // tail.
+    fn consider_builtin_pointee_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
+
+    // A generator (that comes from an `async` desugaring) is known to implement
+    // `Future<Output = O>`, where `O` is given by the generator's return type
+    // that was computed during type-checking.
+    fn consider_builtin_future_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
+
+    // A generator (that doesn't come from an `async` desugaring) is known to
+    // implement `Generator<R, Yield = Y, Return = O>`, given the resume, yield,
+    // and return types of the generator computed during type-checking.
+    fn consider_builtin_generator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
@@ -202,8 +242,6 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             // NOTE: Alternatively we could call `evaluate_goal` here and only have a `Normalized` candidate.
             // This doesn't work as long as we use `CandidateSource` in winnowing.
             let goal = goal.with(tcx, goal.predicate.with_self_ty(tcx, normalized_ty));
-            // FIXME: This is broken if we care about the `usize` of `AliasBound` because the self type
-            // could be normalized to yet another projection with different item bounds.
             let normalized_candidates = self.assemble_and_evaluate_candidates(goal);
             for mut normalized_candidate in normalized_candidates {
                 normalized_candidate.result =
@@ -259,6 +297,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             G::consider_builtin_fn_trait_candidates(self, goal, kind)
         } else if lang_items.tuple_trait() == Some(trait_def_id) {
             G::consider_builtin_tuple_candidate(self, goal)
+        } else if lang_items.pointee_trait() == Some(trait_def_id) {
+            G::consider_builtin_pointee_candidate(self, goal)
+        } else if lang_items.future_trait() == Some(trait_def_id) {
+            G::consider_builtin_future_candidate(self, goal)
+        } else if lang_items.gen_trait() == Some(trait_def_id) {
+            G::consider_builtin_generator_candidate(self, goal)
         } else {
             Err(NoSolution)
         };
@@ -310,25 +354,26 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Param(_)
             | ty::Placeholder(..)
-            | ty::Infer(_)
+            | ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
             | ty::Error(_) => return,
-            ty::Bound(..) => bug!("unexpected bound type: {goal:?}"),
+            ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_))
+            | ty::Bound(..) => bug!("unexpected self type for `{goal:?}`"),
             ty::Alias(_, alias_ty) => alias_ty,
         };
 
-        for (i, (assumption, _)) in self
+        for (assumption, _) in self
             .tcx()
             .bound_explicit_item_bounds(alias_ty.def_id)
             .subst_iter_copied(self.tcx(), alias_ty.substs)
-            .enumerate()
         {
             match G::consider_assumption(self, goal, assumption) {
                 Ok(result) => {
-                    candidates.push(Candidate { source: CandidateSource::AliasBound(i), result })
+                    candidates.push(Candidate { source: CandidateSource::AliasBound, result })
                 }
                 Err(NoSolution) => (),
             }
@@ -360,13 +405,15 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Param(_)
             | ty::Placeholder(..)
-            | ty::Infer(_)
+            | ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
             | ty::Error(_) => return,
-            ty::Bound(..) => bug!("unexpected bound type: {goal:?}"),
+            ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_))
+            | ty::Bound(..) => bug!("unexpected self type for `{goal:?}`"),
             ty::Dynamic(bounds, ..) => bounds,
         };
 
diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index 40b9bedc84f..a2c15123b4f 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -1,14 +1,14 @@
 use std::mem;
 
-use rustc_infer::{
-    infer::InferCtxt,
-    traits::{
-        query::NoSolution, FulfillmentError, FulfillmentErrorCode, PredicateObligation,
-        SelectionError, TraitEngine,
-    },
+use rustc_infer::infer::InferCtxt;
+use rustc_infer::traits::{
+    query::NoSolution, FulfillmentError, FulfillmentErrorCode, MismatchedProjectionTypes,
+    PredicateObligation, SelectionError, TraitEngine,
 };
+use rustc_middle::ty;
+use rustc_middle::ty::error::{ExpectedFound, TypeError};
 
-use super::{search_graph, Certainty, EvalCtxt};
+use super::{Certainty, InferCtxtEvalExt};
 
 /// A trait engine using the new trait solver.
 ///
@@ -40,12 +40,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
         self.obligations.push(obligation);
     }
 
-    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {
-        let errors = self.select_where_possible(infcx);
-        if !errors.is_empty() {
-            return errors;
-        }
-
+    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
         self.obligations
             .drain(..)
             .map(|obligation| FulfillmentError {
@@ -66,16 +61,60 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
             let mut has_changed = false;
             for obligation in mem::take(&mut self.obligations) {
                 let goal = obligation.clone().into();
-                let search_graph = &mut search_graph::SearchGraph::new(infcx.tcx);
-                let mut ecx = EvalCtxt::new_outside_solver(infcx, search_graph);
-                let (changed, certainty) = match ecx.evaluate_goal(goal) {
+                let (changed, certainty) = match infcx.evaluate_root_goal(goal) {
                     Ok(result) => result,
                     Err(NoSolution) => {
                         errors.push(FulfillmentError {
                             obligation: obligation.clone(),
-                            code: FulfillmentErrorCode::CodeSelectionError(
-                                SelectionError::Unimplemented,
-                            ),
+                            code: match goal.predicate.kind().skip_binder() {
+                                ty::PredicateKind::Clause(ty::Clause::Projection(_)) => {
+                                    FulfillmentErrorCode::CodeProjectionError(
+                                        // FIXME: This could be a `Sorts` if the term is a type
+                                        MismatchedProjectionTypes { err: TypeError::Mismatch },
+                                    )
+                                }
+                                ty::PredicateKind::Subtype(pred) => {
+                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                        goal.predicate.kind().rebind((pred.a, pred.b)),
+                                    );
+                                    let expected_found = ExpectedFound::new(true, a, b);
+                                    FulfillmentErrorCode::CodeSubtypeError(
+                                        expected_found,
+                                        TypeError::Sorts(expected_found),
+                                    )
+                                }
+                                ty::PredicateKind::Coerce(pred) => {
+                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                        goal.predicate.kind().rebind((pred.a, pred.b)),
+                                    );
+                                    let expected_found = ExpectedFound::new(false, a, b);
+                                    FulfillmentErrorCode::CodeSubtypeError(
+                                        expected_found,
+                                        TypeError::Sorts(expected_found),
+                                    )
+                                }
+                                ty::PredicateKind::ConstEquate(a, b) => {
+                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                        goal.predicate.kind().rebind((a, b)),
+                                    );
+                                    let expected_found = ExpectedFound::new(true, a, b);
+                                    FulfillmentErrorCode::CodeConstEquateError(
+                                        expected_found,
+                                        TypeError::ConstMismatch(expected_found),
+                                    )
+                                }
+                                ty::PredicateKind::Clause(_)
+                                | ty::PredicateKind::WellFormed(_)
+                                | ty::PredicateKind::ObjectSafe(_)
+                                | ty::PredicateKind::ClosureKind(_, _, _)
+                                | ty::PredicateKind::ConstEvaluatable(_)
+                                | ty::PredicateKind::TypeWellFormedFromEnv(_)
+                                | ty::PredicateKind::Ambiguous => {
+                                    FulfillmentErrorCode::CodeSelectionError(
+                                        SelectionError::Unimplemented,
+                                    )
+                                }
+                            },
                             root_obligation: obligation,
                         });
                         continue;
@@ -100,4 +139,11 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.obligations.clone()
     }
+
+    fn drain_unstalled_obligations(
+        &mut self,
+        _: &InferCtxt<'tcx>,
+    ) -> Vec<PredicateObligation<'tcx>> {
+        unimplemented!()
+    }
 }
diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs
index da2a1a19957..dd16672cc7a 100644
--- a/compiler/rustc_trait_selection/src/solve/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/mod.rs
@@ -13,14 +13,12 @@
 // preserves universes and creates a unique var (in the highest universe) for each
 // appearance of a region.
 
-// FIXME: `CanonicalVarValues` should be interned and `Copy`.
-
 // FIXME: uses of `infcx.at` need to enable deferred projection equality once that's implemented.
 
 use std::mem;
 
 use rustc_hir::def_id::DefId;
-use rustc_infer::infer::canonical::{Canonical, CanonicalVarKind, CanonicalVarValues};
+use rustc_infer::infer::canonical::{Canonical, CanonicalVarValues};
 use rustc_infer::infer::canonical::{OriginalQueryValues, QueryRegionConstraints, QueryResponse};
 use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt};
 use rustc_infer::traits::query::NoSolution;
@@ -141,14 +139,33 @@ type CanonicalResponse<'tcx> = Canonical<'tcx, Response<'tcx>>;
 /// solver, merge the two responses again.
 pub type QueryResult<'tcx> = Result<CanonicalResponse<'tcx>, NoSolution>;
 
-pub trait TyCtxtExt<'tcx> {
-    fn evaluate_goal(self, goal: CanonicalGoal<'tcx>) -> QueryResult<'tcx>;
+pub trait InferCtxtEvalExt<'tcx> {
+    /// Evaluates a goal from **outside** of the trait solver.
+    ///
+    /// Using this while inside of the solver is wrong as it uses a new
+    /// search graph which would break cycle detection.
+    fn evaluate_root_goal(
+        &self,
+        goal: Goal<'tcx, ty::Predicate<'tcx>>,
+    ) -> Result<(bool, Certainty), NoSolution>;
 }
 
-impl<'tcx> TyCtxtExt<'tcx> for TyCtxt<'tcx> {
-    fn evaluate_goal(self, goal: CanonicalGoal<'tcx>) -> QueryResult<'tcx> {
-        let mut search_graph = search_graph::SearchGraph::new(self);
-        EvalCtxt::evaluate_canonical_goal(self, &mut search_graph, goal)
+impl<'tcx> InferCtxtEvalExt<'tcx> for InferCtxt<'tcx> {
+    fn evaluate_root_goal(
+        &self,
+        goal: Goal<'tcx, ty::Predicate<'tcx>>,
+    ) -> Result<(bool, Certainty), NoSolution> {
+        let mut search_graph = search_graph::SearchGraph::new(self.tcx);
+
+        let result = EvalCtxt {
+            search_graph: &mut search_graph,
+            infcx: self,
+            var_values: CanonicalVarValues::dummy(),
+        }
+        .evaluate_goal(goal);
+
+        assert!(search_graph.is_empty());
+        result
     }
 }
 
@@ -164,18 +181,15 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
         self.infcx.tcx
     }
 
-    /// Creates a new evaluation context outside of the trait solver.
+    /// The entry point of the solver.
     ///
-    /// With this solver making a canonical response doesn't make much sense.
-    /// The `search_graph` for this solver has to be completely empty.
-    fn new_outside_solver(
-        infcx: &'a InferCtxt<'tcx>,
-        search_graph: &'a mut search_graph::SearchGraph<'tcx>,
-    ) -> EvalCtxt<'a, 'tcx> {
-        assert!(search_graph.is_empty());
-        EvalCtxt { infcx, var_values: CanonicalVarValues::dummy(), search_graph }
-    }
-
+    /// This function deals with (coinductive) cycles, overflow, and caching
+    /// and then calls [`EvalCtxt::compute_goal`] which contains the actual
+    /// logic of the solver.
+    ///
+    /// Instead of calling this function directly, use either [EvalCtxt::evaluate_goal]
+    /// if you're inside of the solver or [InferCtxtEvalExt::evaluate_root_goal] if you're
+    /// outside of it.
     #[instrument(level = "debug", skip(tcx, search_graph), ret)]
     fn evaluate_canonical_goal(
         tcx: TyCtxt<'tcx>,
@@ -209,7 +223,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
         let external_constraints = take_external_constraints(self.infcx)?;
 
         Ok(self.infcx.canonicalize_response(Response {
-            var_values: self.var_values.clone(),
+            var_values: self.var_values,
             external_constraints,
             certainty,
         }))
@@ -259,12 +273,15 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
                         param_env,
                         predicate: (def_id, substs, kind),
                     }),
+                ty::PredicateKind::ObjectSafe(trait_def_id) => {
+                    self.compute_object_safe_goal(trait_def_id)
+                }
+                ty::PredicateKind::WellFormed(arg) => {
+                    self.compute_well_formed_goal(Goal { param_env, predicate: arg })
+                }
                 ty::PredicateKind::Ambiguous => self.make_canonical_response(Certainty::AMBIGUOUS),
                 // FIXME: implement these predicates :)
-                ty::PredicateKind::WellFormed(_)
-                | ty::PredicateKind::ObjectSafe(_)
-                | ty::PredicateKind::ConstEvaluatable(_)
-                | ty::PredicateKind::ConstEquate(_, _) => {
+                ty::PredicateKind::ConstEvaluatable(_) | ty::PredicateKind::ConstEquate(_, _) => {
                     self.make_canonical_response(Certainty::Yes)
                 }
                 ty::PredicateKind::TypeWellFormedFromEnv(..) => {
@@ -316,15 +333,13 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
             // That won't actually reflect in the query response, so it seems moot.
             self.make_canonical_response(Certainty::AMBIGUOUS)
         } else {
-            self.infcx.probe(|_| {
-                let InferOk { value: (), obligations } = self
-                    .infcx
-                    .at(&ObligationCause::dummy(), goal.param_env)
-                    .sub(goal.predicate.a, goal.predicate.b)?;
-                self.evaluate_all_and_make_canonical_response(
-                    obligations.into_iter().map(|pred| pred.into()).collect(),
-                )
-            })
+            let InferOk { value: (), obligations } = self
+                .infcx
+                .at(&ObligationCause::dummy(), goal.param_env)
+                .sub(goal.predicate.a, goal.predicate.b)?;
+            self.evaluate_all_and_make_canonical_response(
+                obligations.into_iter().map(|pred| pred.into()).collect(),
+            )
         }
     }
 
@@ -344,9 +359,35 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
             Err(NoSolution)
         }
     }
+
+    fn compute_object_safe_goal(&mut self, trait_def_id: DefId) -> QueryResult<'tcx> {
+        if self.tcx().check_is_object_safe(trait_def_id) {
+            self.make_canonical_response(Certainty::Yes)
+        } else {
+            Err(NoSolution)
+        }
+    }
+
+    fn compute_well_formed_goal(
+        &mut self,
+        goal: Goal<'tcx, ty::GenericArg<'tcx>>,
+    ) -> QueryResult<'tcx> {
+        match crate::traits::wf::unnormalized_obligations(
+            self.infcx,
+            goal.param_env,
+            goal.predicate,
+        ) {
+            Some(obligations) => self.evaluate_all_and_make_canonical_response(
+                obligations.into_iter().map(|o| o.into()).collect(),
+            ),
+            None => self.make_canonical_response(Certainty::AMBIGUOUS),
+        }
+    }
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
+    // Recursively evaluates a list of goals to completion, returning the certainty
+    // of all of the goals.
     fn evaluate_all(
         &mut self,
         mut goals: Vec<Goal<'tcx, ty::Predicate<'tcx>>>,
@@ -383,6 +424,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         })
     }
 
+    // Recursively evaluates a list of goals to completion, making a query response.
+    //
+    // This is just a convenient way of calling [`EvalCtxt::evaluate_all`],
+    // then [`EvalCtxt::make_canonical_response`].
     fn evaluate_all_and_make_canonical_response(
         &mut self,
         goals: Vec<Goal<'tcx, ty::Predicate<'tcx>>>,
@@ -436,32 +481,11 @@ pub(super) fn response_no_constraints<'tcx>(
     goal: Canonical<'tcx, impl Sized>,
     certainty: Certainty,
 ) -> QueryResult<'tcx> {
-    let var_values = goal
-        .variables
-        .iter()
-        .enumerate()
-        .map(|(i, info)| match info.kind {
-            CanonicalVarKind::Ty(_) | CanonicalVarKind::PlaceholderTy(_) => {
-                tcx.mk_ty(ty::Bound(ty::INNERMOST, ty::BoundVar::from_usize(i).into())).into()
-            }
-            CanonicalVarKind::Region(_) | CanonicalVarKind::PlaceholderRegion(_) => {
-                let br = ty::BoundRegion {
-                    var: ty::BoundVar::from_usize(i),
-                    kind: ty::BrAnon(i as u32, None),
-                };
-                tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)).into()
-            }
-            CanonicalVarKind::Const(_, ty) | CanonicalVarKind::PlaceholderConst(_, ty) => tcx
-                .mk_const(ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from_usize(i)), ty)
-                .into(),
-        })
-        .collect();
-
     Ok(Canonical {
         max_universe: goal.max_universe,
         variables: goal.variables,
         value: Response {
-            var_values: CanonicalVarValues { var_values },
+            var_values: CanonicalVarValues::make_identity(tcx, goal.variables),
             external_constraints: Default::default(),
             certainty,
         },
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index 32e15f03998..b175a6dde17 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -7,6 +7,7 @@ use super::{Certainty, EvalCtxt, Goal, QueryResult};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
+use rustc_hir::LangItem;
 use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::specialization_graph::LeafDef;
@@ -15,7 +16,7 @@ use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::ty::{ProjectionPredicate, TypeSuperVisitable, TypeVisitor};
 use rustc_middle::ty::{ToPredicate, TypeVisitable};
-use rustc_span::DUMMY_SP;
+use rustc_span::{sym, DUMMY_SP};
 use std::iter;
 use std::ops::ControlFlow;
 
@@ -27,8 +28,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         // To only compute normalization once for each projection we only
         // normalize if the expected term is an unconstrained inference variable.
         //
-        // E.g. for `<T as Trait>::Assoc = u32` we recursively compute the goal
-        // `exists<U> <T as Trait>::Assoc = U` and then take the resulting type for
+        // E.g. for `<T as Trait>::Assoc == u32` we recursively compute the goal
+        // `exists<U> <T as Trait>::Assoc == U` and then take the resulting type for
         // `U` and equate it with `u32`. This means that we don't need a separate
         // projection cache in the solver.
         if self.term_is_fully_unconstrained(goal) {
@@ -92,24 +93,24 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if t.needs_infer() {
                     if ty::Term::from(t) == self.term {
-                        ControlFlow::BREAK
+                        ControlFlow::Break(())
                     } else {
                         t.super_visit_with(self)
                     }
                 } else {
-                    ControlFlow::CONTINUE
+                    ControlFlow::Continue(())
                 }
             }
 
             fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if c.needs_infer() {
                     if ty::Term::from(c) == self.term {
-                        ControlFlow::BREAK
+                        ControlFlow::Break(())
                     } else {
                         c.super_visit_with(self)
                     }
                 } else {
-                    ControlFlow::CONTINUE
+                    ControlFlow::Continue(())
                 }
             }
         }
@@ -170,7 +171,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             (CandidateSource::Impl(_), _)
             | (CandidateSource::ParamEnv(_), _)
             | (CandidateSource::BuiltinImpl, _)
-            | (CandidateSource::AliasBound(_), _) => unimplemented!(),
+            | (CandidateSource::AliasBound, _) => unimplemented!(),
         }
     }
 }
@@ -295,7 +296,9 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
         goal: Goal<'tcx, Self>,
         assumption: ty::Predicate<'tcx>,
     ) -> QueryResult<'tcx> {
-        if let Some(poly_projection_pred) = assumption.to_opt_poly_projection_pred() {
+        if let Some(poly_projection_pred) = assumption.to_opt_poly_projection_pred()
+            && poly_projection_pred.projection_def_id() == goal.predicate.def_id()
+        {
             ecx.infcx.probe(|_| {
                 let assumption_projection_pred =
                     ecx.infcx.instantiate_bound_vars_with_infer(poly_projection_pred);
@@ -391,6 +394,166 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
     ) -> QueryResult<'tcx> {
         bug!("`Tuple` does not have an associated type: {:?}", goal);
     }
+
+    fn consider_builtin_pointee_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let tcx = ecx.tcx();
+        ecx.infcx.probe(|_| {
+            let metadata_ty = match goal.predicate.self_ty().kind() {
+                ty::Bool
+                | ty::Char
+                | ty::Int(..)
+                | ty::Uint(..)
+                | ty::Float(..)
+                | ty::Array(..)
+                | ty::RawPtr(..)
+                | ty::Ref(..)
+                | ty::FnDef(..)
+                | ty::FnPtr(..)
+                | ty::Closure(..)
+                | ty::Infer(ty::IntVar(..) | ty::FloatVar(..))
+                | ty::Generator(..)
+                | ty::GeneratorWitness(..)
+                | ty::GeneratorWitnessMIR(..)
+                | ty::Never
+                | ty::Foreign(..) => tcx.types.unit,
+
+                ty::Error(e) => tcx.ty_error_with_guaranteed(*e),
+
+                ty::Str | ty::Slice(_) => tcx.types.usize,
+
+                ty::Dynamic(_, _, _) => {
+                    let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, None);
+                    tcx.bound_type_of(dyn_metadata)
+                        .subst(tcx, &[ty::GenericArg::from(goal.predicate.self_ty())])
+                }
+
+                ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => {
+                    // FIXME(ptr_metadata): It would also be possible to return a `Ok(Ambig)` with no constraints.
+                    let sized_predicate = ty::Binder::dummy(tcx.at(DUMMY_SP).mk_trait_ref(
+                        LangItem::Sized,
+                        [ty::GenericArg::from(goal.predicate.self_ty())],
+                    ));
+
+                    let mut nested_goals = ecx.infcx.eq(
+                        goal.param_env,
+                        goal.predicate.term.ty().unwrap(),
+                        tcx.types.unit,
+                    )?;
+                    nested_goals.push(goal.with(tcx, sized_predicate));
+
+                    return ecx.evaluate_all_and_make_canonical_response(nested_goals);
+                }
+
+                ty::Adt(def, substs) if def.is_struct() => {
+                    match def.non_enum_variant().fields.last() {
+                        None => tcx.types.unit,
+                        Some(field_def) => {
+                            let self_ty = field_def.ty(tcx, substs);
+                            let new_goal = goal.with(
+                                tcx,
+                                ty::Binder::dummy(goal.predicate.with_self_ty(tcx, self_ty)),
+                            );
+                            return ecx.evaluate_all_and_make_canonical_response(vec![new_goal]);
+                        }
+                    }
+                }
+                ty::Adt(_, _) => tcx.types.unit,
+
+                ty::Tuple(elements) => match elements.last() {
+                    None => tcx.types.unit,
+                    Some(&self_ty) => {
+                        let new_goal = goal.with(
+                            tcx,
+                            ty::Binder::dummy(goal.predicate.with_self_ty(tcx, self_ty)),
+                        );
+                        return ecx.evaluate_all_and_make_canonical_response(vec![new_goal]);
+                    }
+                },
+
+                ty::Infer(
+                    ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_),
+                )
+                | ty::Bound(..) => bug!(
+                    "unexpected self ty `{:?}` when normalizing `<T as Pointee>::Metadata`",
+                    goal.predicate.self_ty()
+                ),
+            };
+
+            let nested_goals =
+                ecx.infcx.eq(goal.param_env, goal.predicate.term.ty().unwrap(), metadata_ty)?;
+            ecx.evaluate_all_and_make_canonical_response(nested_goals)
+        })
+    }
+
+    fn consider_builtin_future_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let self_ty = goal.predicate.self_ty();
+        let ty::Generator(def_id, substs, _) = *self_ty.kind() else {
+            return Err(NoSolution);
+        };
+
+        // Generators are not futures unless they come from `async` desugaring
+        let tcx = ecx.tcx();
+        if !tcx.generator_is_async(def_id) {
+            return Err(NoSolution);
+        }
+
+        let term = substs.as_generator().return_ty().into();
+
+        Self::consider_assumption(
+            ecx,
+            goal,
+            ty::Binder::dummy(ty::ProjectionPredicate {
+                projection_ty: ecx.tcx().mk_alias_ty(goal.predicate.def_id(), [self_ty]),
+                term,
+            })
+            .to_predicate(tcx),
+        )
+    }
+
+    fn consider_builtin_generator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let self_ty = goal.predicate.self_ty();
+        let ty::Generator(def_id, substs, _) = *self_ty.kind() else {
+            return Err(NoSolution);
+        };
+
+        // `async`-desugared generators do not implement the generator trait
+        let tcx = ecx.tcx();
+        if tcx.generator_is_async(def_id) {
+            return Err(NoSolution);
+        }
+
+        let generator = substs.as_generator();
+
+        let name = tcx.associated_item(goal.predicate.def_id()).name;
+        let term = if name == sym::Return {
+            generator.return_ty().into()
+        } else if name == sym::Yield {
+            generator.yield_ty().into()
+        } else {
+            bug!("unexpected associated item `<{self_ty} as Generator>::{name}`")
+        };
+
+        Self::consider_assumption(
+            ecx,
+            goal,
+            ty::Binder::dummy(ty::ProjectionPredicate {
+                projection_ty: ecx
+                    .tcx()
+                    .mk_alias_ty(goal.predicate.def_id(), [self_ty, generator.resume_ty()]),
+                term,
+            })
+            .to_predicate(tcx),
+        )
+    }
 }
 
 /// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code.
diff --git a/compiler/rustc_trait_selection/src/solve/search_graph/cache.rs b/compiler/rustc_trait_selection/src/solve/search_graph/cache.rs
index 730a8e61258..80a388b8498 100644
--- a/compiler/rustc_trait_selection/src/solve/search_graph/cache.rs
+++ b/compiler/rustc_trait_selection/src/solve/search_graph/cache.rs
@@ -95,6 +95,7 @@ impl<'tcx> ProvisionalCache<'tcx> {
     }
 
     pub(super) fn provisional_result(&self, entry_index: EntryIndex) -> QueryResult<'tcx> {
+        // FIXME: Responses should probably be `Copy` as well
         self.entries[entry_index].response.clone()
     }
 }
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 4b6d673c999..1ea8fb8fd3d 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -65,7 +65,9 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         goal: Goal<'tcx, Self>,
         assumption: ty::Predicate<'tcx>,
     ) -> QueryResult<'tcx> {
-        if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred() {
+        if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred()
+            && poly_trait_pred.def_id() == goal.predicate.def_id()
+        {
             // FIXME: Constness and polarity
             ecx.infcx.probe(|_| {
                 let assumption_trait_pred =
@@ -185,6 +187,57 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
             Err(NoSolution)
         }
     }
+
+    fn consider_builtin_pointee_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        _goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        ecx.make_canonical_response(Certainty::Yes)
+    }
+
+    fn consider_builtin_future_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let ty::Generator(def_id, _, _) = *goal.predicate.self_ty().kind() else {
+            return Err(NoSolution);
+        };
+
+        // Generators are not futures unless they come from `async` desugaring
+        let tcx = ecx.tcx();
+        if !tcx.generator_is_async(def_id) {
+            return Err(NoSolution);
+        }
+
+        // Async generator unconditionally implement `Future`
+        ecx.make_canonical_response(Certainty::Yes)
+    }
+
+    fn consider_builtin_generator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let self_ty = goal.predicate.self_ty();
+        let ty::Generator(def_id, substs, _) = *self_ty.kind() else {
+            return Err(NoSolution);
+        };
+
+        // `async`-desugared generators do not implement the generator trait
+        let tcx = ecx.tcx();
+        if tcx.generator_is_async(def_id) {
+            return Err(NoSolution);
+        }
+
+        let generator = substs.as_generator();
+        Self::consider_assumption(
+            ecx,
+            goal,
+            ty::Binder::dummy(
+                tcx.mk_trait_ref(goal.predicate.def_id(), [self_ty, generator.resume_ty()]),
+            )
+            .to_predicate(tcx),
+        )
+    }
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
@@ -269,7 +322,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         match (candidate.source, other.source) {
             (CandidateSource::Impl(_), _)
             | (CandidateSource::ParamEnv(_), _)
-            | (CandidateSource::AliasBound(_), _)
+            | (CandidateSource::AliasBound, _)
             | (CandidateSource::BuiltinImpl, _) => unimplemented!(),
         }
     }
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
index a11cd13cb08..5007a019e18 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
@@ -24,15 +24,16 @@ pub(super) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
         | ty::Never
         | ty::Char => Ok(vec![]),
 
-        ty::Placeholder(..)
-        | ty::Dynamic(..)
+        ty::Dynamic(..)
         | ty::Param(..)
         | ty::Foreign(..)
         | ty::Alias(ty::Projection, ..)
-        | ty::Bound(..)
-        | ty::Infer(ty::TyVar(_)) => Err(NoSolution),
+        | ty::Placeholder(..) => Err(NoSolution),
 
-        ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => bug!(),
+        ty::Bound(..)
+        | ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+            bug!("unexpected type `{ty}`")
+        }
 
         ty::RawPtr(ty::TypeAndMut { ty: element_ty, .. }) | ty::Ref(_, element_ty, _) => {
             Ok(vec![element_ty])
@@ -56,6 +57,8 @@ pub(super) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
             Ok(infcx.replace_bound_vars_with_placeholders(types).to_vec())
         }
 
+        ty::GeneratorWitnessMIR(..) => todo!(),
+
         // For `PhantomData<T>`, we pass `T`.
         ty::Adt(def, substs) if def.is_phantom_data() => Ok(vec![substs.type_at(0)]),
 
@@ -87,6 +90,7 @@ pub(super) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
         | ty::Ref(..)
         | ty::Generator(..)
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::Array(..)
         | ty::Closure(..)
         | ty::Never
@@ -99,11 +103,12 @@ pub(super) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
         | ty::Foreign(..)
         | ty::Alias(..)
         | ty::Param(_)
-        | ty::Infer(ty::TyVar(_)) => Err(NoSolution),
+        | ty::Placeholder(..) => Err(NoSolution),
 
-        ty::Placeholder(..)
-        | ty::Bound(..)
-        | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => bug!(),
+        ty::Bound(..)
+        | ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+            bug!("unexpected type `{ty}`")
+        }
 
         ty::Tuple(tys) => Ok(tys.to_vec()),
 
@@ -148,11 +153,12 @@ pub(super) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
         | ty::Adt(_, _)
         | ty::Alias(_, _)
         | ty::Param(_)
-        | ty::Infer(ty::TyVar(_)) => Err(NoSolution),
+        | ty::Placeholder(..) => Err(NoSolution),
 
-        ty::Placeholder(..)
-        | ty::Bound(..)
-        | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => bug!(),
+        ty::Bound(..)
+        | ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+            bug!("unexpected type `{ty}`")
+        }
 
         ty::Tuple(tys) => Ok(tys.to_vec()),
 
@@ -170,9 +176,12 @@ pub(super) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
         ty::GeneratorWitness(types) => {
             Ok(infcx.replace_bound_vars_with_placeholders(types).to_vec())
         }
+
+        ty::GeneratorWitnessMIR(..) => todo!(),
     }
 }
 
+// Returns a binder of the tupled inputs types and output type from a builtin callable type.
 pub(crate) fn extract_tupled_inputs_and_output_from_callable<'tcx>(
     tcx: TyCtxt<'tcx>,
     self_ty: Ty<'tcx>,
@@ -180,7 +189,7 @@ pub(crate) fn extract_tupled_inputs_and_output_from_callable<'tcx>(
 ) -> Result<Option<ty::Binder<'tcx, (Ty<'tcx>, Ty<'tcx>)>>, NoSolution> {
     match *self_ty.kind() {
         ty::FnDef(def_id, substs) => Ok(Some(
-            tcx.bound_fn_sig(def_id)
+            tcx.fn_sig(def_id)
                 .subst(tcx, substs)
                 .map_bound(|sig| (tcx.mk_tup(sig.inputs().iter()), sig.output())),
         )),
@@ -211,13 +220,18 @@ pub(crate) fn extract_tupled_inputs_and_output_from_callable<'tcx>(
         | ty::Dynamic(_, _, _)
         | ty::Generator(_, _, _)
         | ty::GeneratorWitness(_)
+        | ty::GeneratorWitnessMIR(..)
         | ty::Never
         | ty::Tuple(_)
         | ty::Alias(_, _)
         | ty::Param(_)
-        | ty::Placeholder(_)
-        | ty::Bound(_, _)
-        | ty::Infer(_)
+        | ty::Placeholder(..)
+        | ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
         | ty::Error(_) => Err(NoSolution),
+
+        ty::Bound(..)
+        | ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+            bug!("unexpected type `{self_ty}`")
+        }
     }
 }
diff --git a/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs b/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
index 61d09189798..e26bef0b8b7 100644
--- a/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
@@ -40,15 +40,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         self.obligations.insert(obligation);
     }
 
-    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {
-        {
-            let errors = self.select_where_possible(infcx);
-
-            if !errors.is_empty() {
-                return errors;
-            }
-        }
-
+    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
         // any remaining obligations are errors
         self.obligations
             .iter()
@@ -143,6 +135,13 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         errors
     }
 
+    fn drain_unstalled_obligations(
+        &mut self,
+        _: &InferCtxt<'tcx>,
+    ) -> Vec<PredicateObligation<'tcx>> {
+        unimplemented!()
+    }
+
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.obligations.iter().cloned().collect()
     }
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index 225c1050c7c..61f508a7a07 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -17,7 +17,6 @@ use crate::traits::{
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::Diagnostic;
 use rustc_hir::def_id::{DefId, CRATE_DEF_ID, LOCAL_CRATE};
-use rustc_hir::CRATE_HIR_ID;
 use rustc_infer::infer::{DefiningAnchor, InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::util;
 use rustc_middle::traits::specialization_graph::OverlapMode;
@@ -382,18 +381,14 @@ fn resolve_negative_obligation<'tcx>(
         return false;
     }
 
-    let (body_id, body_def_id) = if let Some(body_def_id) = body_def_id.as_local() {
-        (tcx.hir().local_def_id_to_hir_id(body_def_id), body_def_id)
-    } else {
-        (CRATE_HIR_ID, CRATE_DEF_ID)
-    };
+    let body_def_id = body_def_id.as_local().unwrap_or(CRATE_DEF_ID);
 
     let ocx = ObligationCtxt::new(&infcx);
     let wf_tys = ocx.assumed_wf_types(param_env, DUMMY_SP, body_def_id);
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
         Some(&infcx),
-        infcx.implied_bounds_tys(param_env, body_id, wf_tys),
+        infcx.implied_bounds_tys(param_env, body_def_id, wf_tys),
     );
 
     infcx.process_registered_region_obligations(outlives_env.region_bound_pairs(), param_env);
@@ -701,7 +696,9 @@ impl<'tcx> TypeVisitor<'tcx> for OrphanChecker<'tcx> {
             // This should only be created when checking whether we have to check whether some
             // auto trait impl applies. There will never be multiple impls, so we can just
             // act as if it were a local type here.
-            ty::GeneratorWitness(_) => ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty)),
+            ty::GeneratorWitness(_) | ty::GeneratorWitnessMIR(..) => {
+                ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
+            }
             ty::Alias(ty::Opaque, ..) => {
                 // This merits some explanation.
                 // Normally, opaque types are not involved when performing
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 369f80139a8..a2ddd91546c 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -190,8 +190,7 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         let tcx = self.infcx.tcx;
         let assumed_wf_types = tcx.assumed_wf_types(def_id);
         let mut implied_bounds = FxIndexSet::default();
-        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-        let cause = ObligationCause::misc(span, hir_id);
+        let cause = ObligationCause::misc(span, def_id);
         for ty in assumed_wf_types {
             // FIXME(@lcnr): rustc currently does not check wf for types
             // pre-normalization, meaning that implied bounds are sometimes
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
index 0419bb3f724..6bf453c3ff0 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
@@ -81,7 +81,7 @@ pub fn recompute_applicable_impls<'tcx>(
     );
 
     let predicates =
-        tcx.predicates_of(obligation.cause.body_id.owner.to_def_id()).instantiate_identity(tcx);
+        tcx.predicates_of(obligation.cause.body_id.to_def_id()).instantiate_identity(tcx);
     for obligation in elaborate_predicates_with_span(tcx, predicates.into_iter()) {
         let kind = obligation.predicate.kind();
         if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = kind.skip_binder()
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 52971486c55..e9842b2cba5 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -101,6 +101,18 @@ pub trait InferCtxtExt<'tcx> {
 }
 
 pub trait TypeErrCtxtExt<'tcx> {
+    fn build_overflow_error<T>(
+        &self,
+        predicate: &T,
+        span: Span,
+        suggest_increasing_limit: bool,
+    ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>
+    where
+        T: fmt::Display
+            + TypeFoldable<'tcx>
+            + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
+        <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
+
     fn report_overflow_error<T>(
         &self,
         predicate: &T,
@@ -484,6 +496,26 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
     {
+        let mut err = self.build_overflow_error(predicate, span, suggest_increasing_limit);
+        mutate(&mut err);
+        err.emit();
+
+        self.tcx.sess.abort_if_errors();
+        bug!();
+    }
+
+    fn build_overflow_error<T>(
+        &self,
+        predicate: &T,
+        span: Span,
+        suggest_increasing_limit: bool,
+    ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>
+    where
+        T: fmt::Display
+            + TypeFoldable<'tcx>
+            + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
+        <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
+    {
         let predicate = self.resolve_vars_if_possible(predicate.clone());
         let mut pred_str = predicate.to_string();
 
@@ -511,11 +543,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             self.suggest_new_overflow_limit(&mut err);
         }
 
-        mutate(&mut err);
-
-        err.emit();
-        self.tcx.sess.abort_if_errors();
-        bug!();
+        err
     }
 
     /// Reports that an overflow has occurred and halts compilation. We
@@ -839,14 +867,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             err.note(s.as_str());
                         }
                         if let Some(ref s) = parent_label {
-                            let body = tcx
-                                .hir()
-                                .opt_local_def_id(obligation.cause.body_id)
-                                .unwrap_or_else(|| {
-                                    tcx.hir().body_owner_def_id(hir::BodyId {
-                                        hir_id: obligation.cause.body_id,
-                                    })
-                                });
+                            let body = obligation.cause.body_id;
                             err.span_label(tcx.def_span(body), s);
                         }
 
@@ -934,6 +955,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             );
                         }
 
+                        let body_hir_id =
+                            self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
                         // Try to report a help message
                         if is_fn_trait
                             && let Ok((implemented_kind, params)) = self.type_implements_fn_trait(
@@ -1014,7 +1037,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             if !self.report_similar_impl_candidates(
                                 impl_candidates,
                                 trait_ref,
-                                obligation.cause.body_id,
+                                body_hir_id,
                                 &mut err,
                                 true,
                             ) {
@@ -1050,7 +1073,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                     self.report_similar_impl_candidates(
                                         impl_candidates,
                                         trait_ref,
-                                        obligation.cause.body_id,
+                                        body_hir_id,
                                         &mut err,
                                         true,
                                     );
@@ -1896,6 +1919,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 ty::Generator(..) => Some(16),
                 ty::Foreign(..) => Some(17),
                 ty::GeneratorWitness(..) => Some(18),
+                ty::GeneratorWitnessMIR(..) => Some(19),
                 ty::Placeholder(..) | ty::Bound(..) | ty::Infer(..) | ty::Error(_) => None,
             }
         }
@@ -2305,10 +2329,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                 predicate.to_opt_poly_trait_pred().unwrap(),
                             );
                             if impl_candidates.len() < 10 {
+                                let hir =
+                                    self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
                                 self.report_similar_impl_candidates(
                                     impl_candidates,
                                     trait_ref,
-                                    body_id.map(|id| id.hir_id).unwrap_or(obligation.cause.body_id),
+                                    body_id.map(|id| id.hir_id).unwrap_or(hir),
                                     &mut err,
                                     false,
                                 );
@@ -2828,7 +2854,7 @@ pub struct FindExprBySpan<'hir> {
 }
 
 impl<'hir> FindExprBySpan<'hir> {
-    fn new(span: Span) -> Self {
+    pub fn new(span: Span) -> Self {
         Self { span, result: None, ty_result: None }
     }
 }
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
index 18d308f7123..a3209d35e58 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
@@ -149,10 +149,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             .unwrap_or_else(|| (trait_ref.def_id(), trait_ref.skip_binder().substs));
         let trait_ref = trait_ref.skip_binder();
 
-        let mut flags = vec![(
-            sym::ItemContext,
-            self.describe_enclosure(obligation.cause.body_id).map(|s| s.to_owned()),
-        )];
+        let body_hir = self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
+        let mut flags =
+            vec![(sym::ItemContext, self.describe_enclosure(body_hir).map(|s| s.to_owned()))];
 
         match obligation.cause.code() {
             ObligationCauseCode::BuiltinDerivedObligation(..)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 39e50b2accf..b35b9d62759 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -9,7 +9,6 @@ use crate::infer::InferCtxt;
 use crate::traits::{NormalizeExt, ObligationCtxt};
 
 use hir::def::CtorOf;
-use hir::{Expr, HirId};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{
@@ -22,6 +21,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{AsyncGeneratorKind, GeneratorKind, Node};
+use rustc_hir::{Expr, HirId};
 use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{InferOk, LateBoundRegionConversionTime};
@@ -34,6 +34,7 @@ use rustc_middle::ty::{
     IsSuggestable, ToPredicate, Ty, TyCtxt, TypeAndMut, TypeFoldable, TypeFolder,
     TypeSuperFoldable, TypeVisitable, TypeckResults,
 };
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{BytePos, DesugaringKind, ExpnKind, MacroKind, Span, DUMMY_SP};
 use rustc_target::spec::abi;
@@ -179,7 +180,7 @@ pub trait TypeErrCtxtExt<'tcx> {
         err: &mut Diagnostic,
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         associated_item: Option<(&'static str, Ty<'tcx>)>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     );
 
     fn suggest_dereferences(
@@ -398,7 +399,7 @@ fn predicate_constraint(generics: &hir::Generics<'_>, pred: ty::Predicate<'_>) -
 /// param for cleaner code.
 fn suggest_restriction<'tcx>(
     tcx: TyCtxt<'tcx>,
-    hir_id: HirId,
+    item_id: LocalDefId,
     hir_generics: &hir::Generics<'tcx>,
     msg: &str,
     err: &mut Diagnostic,
@@ -417,7 +418,6 @@ fn suggest_restriction<'tcx>(
     {
         return;
     }
-    let Some(item_id) = hir_id.as_owner() else { return; };
     let generics = tcx.generics_of(item_id);
     // Given `fn foo(t: impl Trait)` where `Trait` requires assoc type `A`...
     if let Some((param, bound_str, fn_sig)) =
@@ -522,7 +522,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         mut err: &mut Diagnostic,
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         associated_ty: Option<(&'static str, Ty<'tcx>)>,
-        body_id: hir::HirId,
+        mut body_id: LocalDefId,
     ) {
         let trait_pred = self.resolve_numeric_literals_with_default(trait_pred);
 
@@ -535,8 +535,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
         // FIXME: Add check for trait bound that is already present, particularly `?Sized` so we
         //        don't suggest `T: Sized + ?Sized`.
-        let mut hir_id = body_id;
-        while let Some(node) = self.tcx.hir().find(hir_id) {
+        while let Some(node) = self.tcx.hir().find_by_def_id(body_id) {
             match node {
                 hir::Node::Item(hir::Item {
                     ident,
@@ -547,7 +546,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     // Restricting `Self` for a single method.
                     suggest_restriction(
                         self.tcx,
-                        hir_id,
+                        body_id,
                         &generics,
                         "`Self`",
                         err,
@@ -567,7 +566,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     assert!(param_ty);
                     // Restricting `Self` for a single method.
                     suggest_restriction(
-                        self.tcx, hir_id, &generics, "`Self`", err, None, projection, trait_pred,
+                        self.tcx, body_id, &generics, "`Self`", err, None, projection, trait_pred,
                         None,
                     );
                     return;
@@ -589,7 +588,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     // Missing restriction on associated type of type parameter (unmet projection).
                     suggest_restriction(
                         self.tcx,
-                        hir_id,
+                        body_id,
                         &generics,
                         "the associated type",
                         err,
@@ -609,7 +608,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     // Missing restriction on associated type of type parameter (unmet projection).
                     suggest_restriction(
                         self.tcx,
-                        hir_id,
+                        body_id,
                         &generics,
                         "the associated type",
                         err,
@@ -713,8 +712,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
                 _ => {}
             }
-
-            hir_id = self.tcx.hir().get_parent_item(hir_id).into();
+            body_id = self.tcx.local_parent(body_id);
         }
     }
 
@@ -905,8 +903,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             trait_pred.self_ty(),
         );
 
+        let body_hir_id = self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
         let Some((def_id_or_name, output, inputs)) = self.extract_callable_info(
-            obligation.cause.body_id,
+            body_hir_id,
             obligation.param_env,
             self_ty,
         ) else { return false; };
@@ -1004,8 +1003,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             span.remove_mark();
         }
         let mut expr_finder = FindExprBySpan::new(span);
-        let Some(hir::Node::Expr(body)) = self.tcx.hir().find(obligation.cause.body_id) else { return; };
-        expr_finder.visit_expr(&body);
+        let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) else { return; };
+        let body = self.tcx.hir().body(body_id);
+        expr_finder.visit_expr(body.value);
         let Some(expr) = expr_finder.result else { return; };
         let Some(typeck) = &self.typeck_results else { return; };
         let Some(ty) = typeck.expr_ty_adjusted_opt(expr) else { return; };
@@ -1060,8 +1060,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> bool {
         let self_ty = self.resolve_vars_if_possible(trait_pred.self_ty());
         let ty = self.tcx.erase_late_bound_regions(self_ty);
-        let owner = self.tcx.hir().get_parent_item(obligation.cause.body_id);
-        let Some(generics) = self.tcx.hir().get_generics(owner.def_id) else { return false };
+        let Some(generics) = self.tcx.hir().get_generics(obligation.cause.body_id) else { return false };
         let ty::Ref(_, inner_ty, hir::Mutability::Not) = ty.kind() else { return false };
         let ty::Param(param) = inner_ty.kind() else { return false };
         let ObligationCauseCode::FunctionArgumentObligation { arg_hir_id, .. } = obligation.cause.code() else { return false };
@@ -1104,6 +1103,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     /// Extracts information about a callable type for diagnostics. This is a
     /// heuristic -- it doesn't necessarily mean that a type is always callable,
     /// because the callable type must also be well-formed to be called.
+    // FIXME(vincenzopalazzo): move the HirId to a LocalDefId
     fn extract_callable_info(
         &self,
         hir_id: HirId,
@@ -1429,10 +1429,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             span.remove_mark();
         }
         let mut expr_finder = super::FindExprBySpan::new(span);
-        let Some(hir::Node::Expr(body)) = self.tcx.hir().find(obligation.cause.body_id) else {
+        let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) else {
             return false;
         };
-        expr_finder.visit_expr(&body);
+        let body = self.tcx.hir().body(body_id);
+        expr_finder.visit_expr(body.value);
         let mut maybe_suggest = |suggested_ty, count, suggestions| {
             // Remapping bound vars here
             let trait_pred_and_suggested_ty =
@@ -1670,8 +1671,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
     ) -> bool {
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(parent_node);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         if let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, _, body_id), .. })) = node
             && let hir::ExprKind::Block(blk, _) = &hir.body(*body_id).value.kind
             && sig.decl.output.span().overlaps(span)
@@ -1707,8 +1707,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
     fn return_type_span(&self, obligation: &PredicateObligation<'tcx>) -> Option<Span> {
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, ..), .. })) = hir.find(parent_node) else {
+        let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, ..), .. })) = hir.find_by_def_id(obligation.cause.body_id) else {
             return None;
         };
 
@@ -1732,8 +1731,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         }
 
         let hir = self.tcx.hir();
-        let fn_hir_id = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(fn_hir_id);
+        let fn_hir_id = hir.local_def_id_to_hir_id(obligation.cause.body_id);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         let Some(hir::Node::Item(hir::Item {
             kind: hir::ItemKind::Fn(sig, _, body_id),
             ..
@@ -1749,7 +1748,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 // If the `dyn Trait` is not object safe, do not suggest `Box<dyn Trait>`.
                 predicates
                     .principal_def_id()
-                    .map_or(true, |def_id| self.tcx.object_safety_violations(def_id).is_empty())
+                    .map_or(true, |def_id| self.tcx.check_is_object_safe(def_id))
             }
             // We only want to suggest `impl Trait` to `dyn Trait`s.
             // For example, `fn foo() -> str` needs to be filtered out.
@@ -1806,7 +1805,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
         match liberated_sig.output().kind() {
             ty::Dynamic(predicates, _, ty::Dyn) => {
-                let cause = ObligationCause::misc(ret_ty.span, fn_hir_id);
+                let cause = ObligationCause::misc(ret_ty.span, obligation.cause.body_id);
                 let param_env = ty::ParamEnv::empty();
 
                 if !only_never_return {
@@ -1944,8 +1943,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         }
 
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(parent_node);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         if let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(_, _, body_id), .. })) =
             node
         {
@@ -2225,7 +2223,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     );
 
                     match *ty.kind() {
-                        ty::Generator(did, ..) => {
+                        ty::Generator(did, ..) | ty::GeneratorWitnessMIR(did, _) => {
                             generator = generator.or(Some(did));
                             outer_generator = Some(did);
                         }
@@ -2255,7 +2253,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     );
 
                     match *ty.kind() {
-                        ty::Generator(did, ..) => {
+                        ty::Generator(did, ..) | ty::GeneratorWitnessMIR(did, ..) => {
                             generator = generator.or(Some(did));
                             outer_generator = Some(did);
                         }
@@ -2344,6 +2342,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             _ => return false,
         };
 
+        let generator_within_in_progress_typeck = match &self.typeck_results {
+            Some(t) => t.hir_owner.to_def_id() == generator_did_root,
+            _ => false,
+        };
+
         let mut interior_or_upvar_span = None;
 
         let from_awaited_ty = generator_data.get_from_await_ty(visitor, hir, ty_matches);
@@ -2363,6 +2366,35 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 *span,
                 Some((*scope_span, *yield_span, *expr, from_awaited_ty)),
             ));
+
+            if interior_or_upvar_span.is_none() && generator_data.is_foreign() {
+                interior_or_upvar_span = Some(GeneratorInteriorOrUpvar::Interior(*span, None));
+            }
+        } else if self.tcx.sess.opts.unstable_opts.drop_tracking_mir
+            // Avoid disclosing internal information to downstream crates.
+            && generator_did.is_local()
+            // Try to avoid cycles.
+            && !generator_within_in_progress_typeck
+        {
+            let generator_info = &self.tcx.mir_generator_witnesses(generator_did);
+            debug!(?generator_info);
+
+            'find_source: for (variant, source_info) in
+                generator_info.variant_fields.iter().zip(&generator_info.variant_source_info)
+            {
+                debug!(?variant);
+                for &local in variant {
+                    let decl = &generator_info.field_tys[local];
+                    debug!(?decl);
+                    if ty_matches(ty::Binder::dummy(decl.ty)) && !decl.ignore_for_traits {
+                        interior_or_upvar_span = Some(GeneratorInteriorOrUpvar::Interior(
+                            decl.source_info.span,
+                            Some((None, source_info.span, None, from_awaited_ty)),
+                        ));
+                        break 'find_source;
+                    }
+                }
+            }
         }
 
         if interior_or_upvar_span.is_none() {
@@ -3011,6 +3043,20 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                 }
                                 err.note(msg.trim_end_matches(", "))
                             }
+                            ty::GeneratorWitnessMIR(def_id, substs) => {
+                                use std::fmt::Write;
+
+                                // FIXME: this is kind of an unusual format for rustc, can we make it more clear?
+                                // Maybe we should just remove this note altogether?
+                                // FIXME: only print types which don't meet the trait requirement
+                                let mut msg =
+                                    "required because it captures the following types: ".to_owned();
+                                for bty in tcx.generator_hidden_types(*def_id) {
+                                    let ty = bty.subst(tcx, substs);
+                                    write!(msg, "`{}`, ", ty).unwrap();
+                                }
+                                err.note(msg.trim_end_matches(", "))
+                            }
                             ty::Generator(def_id, _, _) => {
                                 let sp = self.tcx.def_span(def_id);
 
@@ -3283,12 +3329,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         span: Span,
     ) {
-        let body_hir_id = obligation.cause.body_id;
-        let item_id = self.tcx.hir().parent_id(body_hir_id);
-
-        if let Some(body_id) =
-            self.tcx.hir().maybe_body_owned_by(self.tcx.hir().local_def_id(item_id))
-        {
+        if let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) {
             let body = self.tcx.hir().body(body_id);
             if let Some(hir::GeneratorKind::Async(_)) = body.generator_kind {
                 let future_trait = self.tcx.require_lang_item(LangItem::Future, None);
@@ -3727,9 +3768,14 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     term: ty_var.into(),
                 },
             )));
+            let body_def_id = self.tcx.hir().enclosing_body_owner(body_id);
             // Add `<ExprTy as Iterator>::Item = _` obligation.
             ocx.register_obligation(Obligation::misc(
-                self.tcx, span, body_id, param_env, projection,
+                self.tcx,
+                span,
+                body_def_id,
+                param_env,
+                projection,
             ));
             if ocx.select_where_possible().is_empty() {
                 // `ty_var` now holds the type that `Item` is for `ExprTy`.
@@ -3758,13 +3804,13 @@ fn hint_missing_borrow<'tcx>(
     err: &mut Diagnostic,
 ) {
     let found_args = match found.kind() {
-        ty::FnPtr(f) => f.inputs().skip_binder().iter(),
+        ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
         kind => {
             span_bug!(span, "found was converted to a FnPtr above but is now {:?}", kind)
         }
     };
     let expected_args = match expected.kind() {
-        ty::FnPtr(f) => f.inputs().skip_binder().iter(),
+        ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
         kind => {
             span_bug!(span, "expected was converted to a FnPtr above but is now {:?}", kind)
         }
@@ -3775,12 +3821,12 @@ fn hint_missing_borrow<'tcx>(
 
     let args = fn_decl.inputs.iter().map(|ty| ty);
 
-    fn get_deref_type_and_refs(mut ty: Ty<'_>) -> (Ty<'_>, usize) {
-        let mut refs = 0;
+    fn get_deref_type_and_refs(mut ty: Ty<'_>) -> (Ty<'_>, Vec<hir::Mutability>) {
+        let mut refs = vec![];
 
-        while let ty::Ref(_, new_ty, _) = ty.kind() {
+        while let ty::Ref(_, new_ty, mutbl) = ty.kind() {
             ty = *new_ty;
-            refs += 1;
+            refs.push(*mutbl);
         }
 
         (ty, refs)
@@ -3794,11 +3840,21 @@ fn hint_missing_borrow<'tcx>(
         let (expected_ty, expected_refs) = get_deref_type_and_refs(*expected_arg);
 
         if infcx.can_eq(param_env, found_ty, expected_ty).is_ok() {
-            if found_refs < expected_refs {
-                to_borrow.push((arg.span.shrink_to_lo(), "&".repeat(expected_refs - found_refs)));
-            } else if found_refs > expected_refs {
+            // FIXME: This could handle more exotic cases like mutability mismatches too!
+            if found_refs.len() < expected_refs.len()
+                && found_refs[..] == expected_refs[expected_refs.len() - found_refs.len()..]
+            {
+                to_borrow.push((
+                    arg.span.shrink_to_lo(),
+                    expected_refs[..expected_refs.len() - found_refs.len()]
+                        .iter()
+                        .map(|mutbl| format!("&{}", mutbl.prefix_str()))
+                        .collect::<Vec<_>>()
+                        .join(""),
+                ));
+            } else if found_refs.len() > expected_refs.len() {
                 let mut span = arg.span.shrink_to_lo();
-                let mut left = found_refs - expected_refs;
+                let mut left = found_refs.len() - expected_refs.len();
                 let mut ty = arg;
                 while let hir::TyKind::Ref(_, mut_ty) = &ty.kind && left > 0 {
                     span = span.with_hi(mut_ty.ty.span.lo());
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index 5a58d37e183..18d30771035 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -132,14 +132,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
             .register_obligation(PendingPredicateObligation { obligation, stalled_on: vec![] });
     }
 
-    fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {
-        {
-            let errors = self.select_where_possible(infcx);
-            if !errors.is_empty() {
-                return errors;
-            }
-        }
-
+    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
         self.predicates.to_errors(CodeAmbiguity).into_iter().map(to_fulfillment_error).collect()
     }
 
@@ -148,6 +141,55 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         self.select(selcx)
     }
 
+    fn drain_unstalled_obligations(
+        &mut self,
+        infcx: &InferCtxt<'tcx>,
+    ) -> Vec<PredicateObligation<'tcx>> {
+        let mut processor = DrainProcessor { removed_predicates: Vec::new(), infcx };
+        let outcome: Outcome<_, _> = self.predicates.process_obligations(&mut processor);
+        assert!(outcome.errors.is_empty());
+        return processor.removed_predicates;
+
+        struct DrainProcessor<'a, 'tcx> {
+            infcx: &'a InferCtxt<'tcx>,
+            removed_predicates: Vec<PredicateObligation<'tcx>>,
+        }
+
+        impl<'tcx> ObligationProcessor for DrainProcessor<'_, 'tcx> {
+            type Obligation = PendingPredicateObligation<'tcx>;
+            type Error = !;
+            type OUT = Outcome<Self::Obligation, Self::Error>;
+
+            fn needs_process_obligation(&self, pending_obligation: &Self::Obligation) -> bool {
+                pending_obligation
+                    .stalled_on
+                    .iter()
+                    .any(|&var| self.infcx.ty_or_const_infer_var_changed(var))
+            }
+
+            fn process_obligation(
+                &mut self,
+                pending_obligation: &mut PendingPredicateObligation<'tcx>,
+            ) -> ProcessResult<PendingPredicateObligation<'tcx>, !> {
+                assert!(self.needs_process_obligation(pending_obligation));
+                self.removed_predicates.push(pending_obligation.obligation.clone());
+                ProcessResult::Changed(vec![])
+            }
+
+            fn process_backedge<'c, I>(
+                &mut self,
+                cycle: I,
+                _marker: PhantomData<&'c PendingPredicateObligation<'tcx>>,
+            ) -> Result<(), !>
+            where
+                I: Clone + Iterator<Item = &'c PendingPredicateObligation<'tcx>>,
+            {
+                self.removed_predicates.extend(cycle.map(|c| c.obligation.clone()));
+                Ok(())
+            }
+        }
+    }
+
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.predicates.map_pending_obligations(|o| o.obligation.clone())
     }
@@ -327,7 +369,7 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                 }
 
                 ty::PredicateKind::ObjectSafe(trait_def_id) => {
-                    if !self.selcx.tcx().is_object_safe(trait_def_id) {
+                    if !self.selcx.tcx().check_is_object_safe(trait_def_id) {
                         ProcessResult::Error(CodeSelectionError(Unimplemented))
                     } else {
                         ProcessResult::Changed(vec![])
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 3c640cdc503..83458017e00 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -26,12 +26,11 @@ use crate::infer::{InferCtxt, TyCtxtInferExt};
 use crate::traits::error_reporting::TypeErrCtxtExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_errors::ErrorGuaranteed;
-use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeSuperVisitable};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
+use rustc_span::def_id::{DefId, CRATE_DEF_ID};
 use rustc_span::Span;
 
 use std::fmt::Debug;
@@ -151,7 +150,7 @@ fn pred_known_to_hold_modulo_regions<'tcx>(
         // We can use a dummy node-id here because we won't pay any mind
         // to region obligations that arise (there shouldn't really be any
         // anyhow).
-        cause: ObligationCause::misc(span, hir::CRATE_HIR_ID),
+        cause: ObligationCause::misc(span, CRATE_DEF_ID),
         recursion_depth: 0,
         predicate: pred.to_predicate(infcx.tcx),
     };
@@ -166,14 +165,12 @@ fn pred_known_to_hold_modulo_regions<'tcx>(
         // that guess. While imperfect, I believe this is sound.
 
         // FIXME(@lcnr): this function doesn't seem right.
+        //
         // The handling of regions in this area of the code is terrible,
         // see issue #29149. We should be able to improve on this with
         // NLL.
         let errors = fully_solve_obligation(infcx, obligation);
 
-        // Note: we only assume something is `Copy` if we can
-        // *definitively* show that it implements `Copy`. Otherwise,
-        // assume it is move; linear is always ok.
         match &errors[..] {
             [] => true,
             errors => {
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index c9121212cd8..565cfca9090 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -62,6 +62,37 @@ fn object_safety_violations(tcx: TyCtxt<'_>, trait_def_id: DefId) -> &'_ [Object
     )
 }
 
+fn check_is_object_safe(tcx: TyCtxt<'_>, trait_def_id: DefId) -> bool {
+    let violations = tcx.object_safety_violations(trait_def_id);
+
+    if violations.is_empty() {
+        return true;
+    }
+
+    // If the trait contains any other violations, then let the error reporting path
+    // report it instead of emitting a warning here.
+    if violations.iter().all(|violation| {
+        matches!(
+            violation,
+            ObjectSafetyViolation::Method(_, MethodViolationCode::WhereClauseReferencesSelf, _)
+        )
+    }) {
+        for violation in violations {
+            if let ObjectSafetyViolation::Method(
+                _,
+                MethodViolationCode::WhereClauseReferencesSelf,
+                span,
+            ) = violation
+            {
+                lint_object_unsafe_trait(tcx, *span, trait_def_id, &violation);
+            }
+        }
+        return true;
+    }
+
+    false
+}
+
 /// We say a method is *vtable safe* if it can be invoked on a trait
 /// object. Note that object-safe traits can have some
 /// non-vtable-safe methods, so long as they require `Self: Sized` or
@@ -93,19 +124,6 @@ fn object_safety_violations_for_trait(
             object_safety_violation_for_method(tcx, trait_def_id, &item)
                 .map(|(code, span)| ObjectSafetyViolation::Method(item.name, code, span))
         })
-        .filter(|violation| {
-            if let ObjectSafetyViolation::Method(
-                _,
-                MethodViolationCode::WhereClauseReferencesSelf,
-                span,
-            ) = violation
-            {
-                lint_object_unsafe_trait(tcx, *span, trait_def_id, &violation);
-                false
-            } else {
-                true
-            }
-        })
         .collect();
 
     // Check the trait itself.
@@ -395,7 +413,7 @@ fn virtual_call_violation_for_method<'tcx>(
     trait_def_id: DefId,
     method: &ty::AssocItem,
 ) -> Option<MethodViolationCode> {
-    let sig = tcx.fn_sig(method.def_id);
+    let sig = tcx.fn_sig(method.def_id).subst_identity();
 
     // The method's first parameter must be named `self`
     if !method.fn_has_self_parameter {
@@ -866,5 +884,6 @@ pub fn contains_illegal_impl_trait_in_trait<'tcx>(
 }
 
 pub fn provide(providers: &mut ty::query::Providers) {
-    *providers = ty::query::Providers { object_safety_violations, ..*providers };
+    *providers =
+        ty::query::Providers { object_safety_violations, check_is_object_safe, ..*providers };
 }
diff --git a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
index f2c5f730b31..6cb64ad574f 100644
--- a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
+++ b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
@@ -3,9 +3,8 @@ use crate::traits::query::type_op::{self, TypeOp, TypeOpOutput};
 use crate::traits::query::NoSolution;
 use crate::traits::ObligationCause;
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_hir as hir;
-use rustc_hir::HirId;
 use rustc_middle::ty::{self, ParamEnv, Ty};
+use rustc_span::def_id::LocalDefId;
 
 pub use rustc_middle::traits::query::OutlivesBound;
 
@@ -14,14 +13,14 @@ pub trait InferCtxtExt<'a, 'tcx> {
     fn implied_outlives_bounds(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         ty: Ty<'tcx>,
     ) -> Vec<OutlivesBound<'tcx>>;
 
     fn implied_bounds_tys(
         &'a self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         tys: FxIndexSet<Ty<'tcx>>,
     ) -> Bounds<'a, 'tcx>;
 }
@@ -50,10 +49,10 @@ impl<'a, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'tcx> {
     fn implied_outlives_bounds(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         ty: Ty<'tcx>,
     ) -> Vec<OutlivesBound<'tcx>> {
-        let span = self.tcx.hir().span(body_id);
+        let span = self.tcx.def_span(body_id);
         let result = param_env
             .and(type_op::implied_outlives_bounds::ImpliedOutlivesBounds { ty })
             .fully_perform(self);
@@ -102,7 +101,7 @@ impl<'a, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'tcx> {
     fn implied_bounds_tys(
         &'a self,
         param_env: ParamEnv<'tcx>,
-        body_id: HirId,
+        body_id: LocalDefId,
         tys: FxIndexSet<Ty<'tcx>>,
     ) -> Bounds<'a, 'tcx> {
         tys.into_iter()
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index fbc7eccedc8..a11c5e81969 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1605,6 +1605,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                         | ty::Closure(..)
                         | ty::Generator(..)
                         | ty::GeneratorWitness(..)
+                        | ty::GeneratorWitnessMIR(..)
                         | ty::Never
                         | ty::Tuple(..)
                         // Integers and floats always have `u8` as their discriminant.
@@ -1654,6 +1655,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                         | ty::Closure(..)
                         | ty::Generator(..)
                         | ty::GeneratorWitness(..)
+                        | ty::GeneratorWitnessMIR(..)
                         | ty::Never
                         // Extern types have unit metadata, according to RFC 2850
                         | ty::Foreign(_)
diff --git a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs
index 0f21813bc40..455b53bfb7d 100644
--- a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs
@@ -31,6 +31,7 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
         | ty::FnPtr(_)
         | ty::Char
         | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
         | ty::RawPtr(_)
         | ty::Ref(..)
         | ty::Str
diff --git a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
index 09b58894d30..f183248f2d0 100644
--- a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
@@ -1,7 +1,9 @@
 use rustc_middle::ty;
+use rustc_session::config::TraitSolver;
 
 use crate::infer::canonical::OriginalQueryValues;
 use crate::infer::InferCtxt;
+use crate::solve::{Certainty, Goal, InferCtxtEvalExt, MaybeCause};
 use crate::traits::{EvaluationResult, OverflowError, PredicateObligation, SelectionContext};
 
 pub trait InferCtxtExt<'tcx> {
@@ -77,12 +79,38 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
             _ => obligation.param_env.without_const(),
         };
 
-        let c_pred = self
-            .canonicalize_query_keep_static(param_env.and(obligation.predicate), &mut _orig_values);
-        // Run canonical query. If overflow occurs, rerun from scratch but this time
-        // in standard trait query mode so that overflow is handled appropriately
-        // within `SelectionContext`.
-        self.tcx.at(obligation.cause.span()).evaluate_obligation(c_pred)
+        if self.tcx.sess.opts.unstable_opts.trait_solver != TraitSolver::Next {
+            let c_pred = self.canonicalize_query_keep_static(
+                param_env.and(obligation.predicate),
+                &mut _orig_values,
+            );
+            self.tcx.at(obligation.cause.span()).evaluate_obligation(c_pred)
+        } else {
+            self.probe(|snapshot| {
+                if let Ok((_, certainty)) =
+                    self.evaluate_root_goal(Goal::new(self.tcx, param_env, obligation.predicate))
+                {
+                    match certainty {
+                        Certainty::Yes => {
+                            if self.opaque_types_added_in_snapshot(snapshot) {
+                                Ok(EvaluationResult::EvaluatedToOkModuloOpaqueTypes)
+                            } else if self.region_constraints_added_in_snapshot(snapshot).is_some()
+                            {
+                                Ok(EvaluationResult::EvaluatedToOkModuloRegions)
+                            } else {
+                                Ok(EvaluationResult::EvaluatedToOk)
+                            }
+                        }
+                        Certainty::Maybe(MaybeCause::Ambiguity) => {
+                            Ok(EvaluationResult::EvaluatedToAmbig)
+                        }
+                        Certainty::Maybe(MaybeCause::Overflow) => Err(OverflowError::Canonical),
+                    }
+                } else {
+                    Ok(EvaluationResult::EvaluatedToErr)
+                }
+            })
+        }
     }
 
     // Helper function that canonicalizes and runs the query. If an
@@ -92,6 +120,9 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         &self,
         obligation: &PredicateObligation<'tcx>,
     ) -> EvaluationResult {
+        // Run canonical query. If overflow occurs, rerun from scratch but this time
+        // in standard trait query mode so that overflow is handled appropriately
+        // within `SelectionContext`.
         match self.evaluate_obligation(obligation) {
             Ok(result) => result,
             Err(OverflowError::Canonical) => {
diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
index 27247271d1f..1b2533a5cf6 100644
--- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
@@ -216,12 +216,16 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
                         let substs = substs.try_fold_with(self)?;
                         let recursion_limit = self.tcx().recursion_limit();
                         if !recursion_limit.value_within_limit(self.anon_depth) {
-                            self.infcx.err_ctxt().report_overflow_error(
-                                &ty,
-                                self.cause.span,
-                                true,
-                                |_| {},
-                            );
+                            // A closure or generator may have itself as in its upvars.
+                            // This should be checked handled by the recursion check for opaque
+                            // types, but we may end up here before that check can happen.
+                            // In that case, we delay a bug to mark the trip, and continue without
+                            // revealing the opaque.
+                            self.infcx
+                                .err_ctxt()
+                                .build_overflow_error(&ty, self.cause.span, true)
+                                .delay_as_bug();
+                            return ty.try_super_fold_with(self);
                         }
 
                         let generic_ty = self.tcx().bound_type_of(def_id);
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index 2733d9643fd..7b7abcf552a 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -174,8 +174,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             .param_env
             .caller_bounds()
             .iter()
-            .filter_map(|p| p.to_opt_poly_trait_pred())
-            .filter(|p| !p.references_error());
+            .filter(|p| !p.references_error())
+            .filter_map(|p| p.to_opt_poly_trait_pred());
 
         // Micro-optimization: filter out predicates relating to different traits.
         let matching_bounds =
@@ -466,7 +466,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     if let Some(principal) = data.principal() {
                         if !self.infcx.tcx.features().object_safe_for_dispatch {
                             principal.with_self_ty(self.tcx(), self_ty)
-                        } else if self.tcx().is_object_safe(principal.def_id()) {
+                        } else if self.tcx().check_is_object_safe(principal.def_id()) {
                             principal.with_self_ty(self.tcx(), self_ty)
                         } else {
                             return;
@@ -765,7 +765,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::Tuple(_)
-            | ty::GeneratorWitness(_) => {
+            | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..) => {
                 // These are built-in, and cannot have a custom `impl const Destruct`.
                 candidates.vec.push(ConstDestructCandidate(None));
             }
@@ -826,6 +827,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Closure(_, _)
             | ty::Generator(_, _, _)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Never
             | ty::Alias(..)
             | ty::Param(_)
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 82a59831be3..89a8fdbac1c 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -8,12 +8,11 @@
 //! https://rustc-dev-guide.rust-lang.org/traits/resolution.html#confirmation
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::lang_items::LangItem;
-use rustc_index::bit_set::GrowableBitSet;
 use rustc_infer::infer::InferOk;
 use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
 use rustc_middle::ty::{
-    self, Binder, GenericArg, GenericArgKind, GenericParamDefKind, InternalSubsts, SubstsRef,
-    ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt,
+    self, Binder, GenericParamDefKind, InternalSubsts, SubstsRef, ToPolyTraitRef, ToPredicate,
+    TraitRef, Ty, TyCtxt, TypeVisitable,
 };
 use rustc_session::config::TraitSolver;
 use rustc_span::def_id::DefId;
@@ -1009,7 +1008,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             // `T` -> `Trait`
             (_, &ty::Dynamic(ref data, r, ty::Dyn)) => {
                 let mut object_dids = data.auto_traits().chain(data.principal_def_id());
-                if let Some(did) = object_dids.find(|did| !tcx.is_object_safe(*did)) {
+                if let Some(did) = object_dids.find(|did| !tcx.check_is_object_safe(*did)) {
                     return Err(TraitNotObjectSafe(did));
                 }
 
@@ -1064,51 +1063,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
             // `Struct<T>` -> `Struct<U>`
             (&ty::Adt(def, substs_a), &ty::Adt(_, substs_b)) => {
-                let maybe_unsizing_param_idx = |arg: GenericArg<'tcx>| match arg.unpack() {
-                    GenericArgKind::Type(ty) => match ty.kind() {
-                        ty::Param(p) => Some(p.index),
-                        _ => None,
-                    },
-
-                    // Lifetimes aren't allowed to change during unsizing.
-                    GenericArgKind::Lifetime(_) => None,
-
-                    GenericArgKind::Const(ct) => match ct.kind() {
-                        ty::ConstKind::Param(p) => Some(p.index),
-                        _ => None,
-                    },
-                };
-
-                // FIXME(eddyb) cache this (including computing `unsizing_params`)
-                // by putting it in a query; it would only need the `DefId` as it
-                // looks at declared field types, not anything substituted.
-
-                // The last field of the structure has to exist and contain type/const parameters.
-                let (tail_field, prefix_fields) =
-                    def.non_enum_variant().fields.split_last().ok_or(Unimplemented)?;
-                let tail_field_ty = tcx.bound_type_of(tail_field.did);
-
-                let mut unsizing_params = GrowableBitSet::new_empty();
-                for arg in tail_field_ty.0.walk() {
-                    if let Some(i) = maybe_unsizing_param_idx(arg) {
-                        unsizing_params.insert(i);
-                    }
-                }
-
-                // Ensure none of the other fields mention the parameters used
-                // in unsizing.
-                for field in prefix_fields {
-                    for arg in tcx.type_of(field.did).walk() {
-                        if let Some(i) = maybe_unsizing_param_idx(arg) {
-                            unsizing_params.remove(i);
-                        }
-                    }
-                }
-
+                let unsizing_params = tcx.unsizing_params_for_adt(def.did());
                 if unsizing_params.is_empty() {
                     return Err(Unimplemented);
                 }
 
+                let tail_field = def
+                    .non_enum_variant()
+                    .fields
+                    .last()
+                    .expect("expected unsized ADT to have a tail field");
+                let tail_field_ty = tcx.bound_type_of(tail_field.did);
+
                 // Extract `TailField<T>` and `TailField<U>` from `Struct<T>` and `Struct<U>`,
                 // normalizing in the process, since `type_of` returns something directly from
                 // astconv (which means it's un-normalized).
@@ -1285,6 +1251,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 ty::GeneratorWitness(tys) => {
                     stack.extend(tcx.erase_late_bound_regions(tys).to_vec());
                 }
+                ty::GeneratorWitnessMIR(def_id, substs) => {
+                    let tcx = self.tcx();
+                    stack.extend(tcx.generator_hidden_types(def_id).map(|bty| {
+                        let ty = bty.subst(tcx, substs);
+                        debug_assert!(!ty.has_late_bound_regions());
+                        ty
+                    }))
+                }
 
                 // If we have a projection type, make sure to normalize it so we replace it
                 // with a fresh infer variable
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index f90da95d516..b8f5aeee2d5 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -38,6 +38,8 @@ use rustc_errors::Diagnostic;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::LateBoundRegionConversionTime;
+use rustc_infer::traits::TraitEngine;
+use rustc_infer::traits::TraitEngineExt;
 use rustc_middle::dep_graph::{DepKind, DepNodeIndex};
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
@@ -47,6 +49,7 @@ use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::SubstsRef;
 use rustc_middle::ty::{self, EarlyBinder, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate};
 use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_session::config::TraitSolver;
 use rustc_span::symbol::sym;
 
 use std::cell::{Cell, RefCell};
@@ -544,10 +547,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &PredicateObligation<'tcx>,
     ) -> Result<EvaluationResult, OverflowError> {
         self.evaluation_probe(|this| {
-            this.evaluate_predicate_recursively(
-                TraitObligationStackList::empty(&ProvisionalEvaluationCache::default()),
-                obligation.clone(),
-            )
+            if this.tcx().sess.opts.unstable_opts.trait_solver != TraitSolver::Next {
+                this.evaluate_predicate_recursively(
+                    TraitObligationStackList::empty(&ProvisionalEvaluationCache::default()),
+                    obligation.clone(),
+                )
+            } else {
+                this.evaluate_predicates_recursively_in_new_solver([obligation.clone()])
+            }
         })
     }
 
@@ -586,18 +593,40 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     where
         I: IntoIterator<Item = PredicateObligation<'tcx>> + std::fmt::Debug,
     {
-        let mut result = EvaluatedToOk;
-        for obligation in predicates {
-            let eval = self.evaluate_predicate_recursively(stack, obligation.clone())?;
-            if let EvaluatedToErr = eval {
-                // fast-path - EvaluatedToErr is the top of the lattice,
-                // so we don't need to look on the other predicates.
-                return Ok(EvaluatedToErr);
-            } else {
-                result = cmp::max(result, eval);
+        if self.tcx().sess.opts.unstable_opts.trait_solver != TraitSolver::Next {
+            let mut result = EvaluatedToOk;
+            for obligation in predicates {
+                let eval = self.evaluate_predicate_recursively(stack, obligation.clone())?;
+                if let EvaluatedToErr = eval {
+                    // fast-path - EvaluatedToErr is the top of the lattice,
+                    // so we don't need to look on the other predicates.
+                    return Ok(EvaluatedToErr);
+                } else {
+                    result = cmp::max(result, eval);
+                }
             }
+            Ok(result)
+        } else {
+            self.evaluate_predicates_recursively_in_new_solver(predicates)
         }
-        Ok(result)
+    }
+
+    /// Evaluates the predicates using the new solver when `-Ztrait-solver=next` is enabled
+    fn evaluate_predicates_recursively_in_new_solver(
+        &mut self,
+        predicates: impl IntoIterator<Item = PredicateObligation<'tcx>>,
+    ) -> Result<EvaluationResult, OverflowError> {
+        let mut fulfill_cx = crate::solve::FulfillmentCtxt::new();
+        fulfill_cx.register_predicate_obligations(self.infcx, predicates);
+        // True errors
+        if !fulfill_cx.select_where_possible(self.infcx).is_empty() {
+            return Ok(EvaluatedToErr);
+        }
+        if !fulfill_cx.select_all_or_error(self.infcx).is_empty() {
+            return Ok(EvaluatedToAmbig);
+        }
+        // Regions and opaques are handled in the `evaluation_probe` by looking at the snapshot
+        Ok(EvaluatedToOk)
     }
 
     #[instrument(
@@ -768,7 +797,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 }
 
                 ty::PredicateKind::ObjectSafe(trait_def_id) => {
-                    if self.tcx().is_object_safe(trait_def_id) {
+                    if self.tcx().check_is_object_safe(trait_def_id) {
                         Ok(EvaluatedToOk)
                     } else {
                         Ok(EvaluatedToErr)
@@ -2037,6 +2066,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Ref(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Array(..)
             | ty::Closure(..)
             | ty::Never
@@ -2153,6 +2183,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Where(ty::Binder::bind_with_vars(witness_tys.to_vec(), all_vars))
             }
 
+            ty::GeneratorWitnessMIR(def_id, ref substs) => {
+                let hidden_types = bind_generator_hidden_types_above(
+                    self.infcx,
+                    def_id,
+                    substs,
+                    obligation.predicate.bound_vars(),
+                );
+                Where(hidden_types)
+            }
+
             ty::Closure(_, substs) => {
                 // (*) binder moved here
                 let ty = self.infcx.shallow_resolve(substs.as_closure().tupled_upvars_ty());
@@ -2250,6 +2290,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 types.map_bound(|types| types.to_vec())
             }
 
+            ty::GeneratorWitnessMIR(def_id, ref substs) => {
+                bind_generator_hidden_types_above(self.infcx, def_id, substs, t.bound_vars())
+            }
+
             // For `PhantomData<T>`, we pass `T`.
             ty::Adt(def, substs) if def.is_phantom_data() => t.rebind(substs.types().collect()),
 
@@ -2892,3 +2936,56 @@ pub enum ProjectionMatchesProjection {
     Ambiguous,
     No,
 }
+
+/// Replace all regions inside the generator interior with late bound regions.
+/// Note that each region slot in the types gets a new fresh late bound region, which means that
+/// none of the regions inside relate to any other, even if typeck had previously found constraints
+/// that would cause them to be related.
+#[instrument(level = "trace", skip(infcx), ret)]
+fn bind_generator_hidden_types_above<'tcx>(
+    infcx: &InferCtxt<'tcx>,
+    def_id: DefId,
+    substs: ty::SubstsRef<'tcx>,
+    bound_vars: &ty::List<ty::BoundVariableKind>,
+) -> ty::Binder<'tcx, Vec<Ty<'tcx>>> {
+    let tcx = infcx.tcx;
+    let mut seen_tys = FxHashSet::default();
+
+    let considering_regions = infcx.considering_regions;
+
+    let num_bound_variables = bound_vars.len() as u32;
+    let mut counter = num_bound_variables;
+
+    let hidden_types: Vec<_> = tcx
+        .generator_hidden_types(def_id)
+        // Deduplicate tys to avoid repeated work.
+        .filter(|bty| seen_tys.insert(*bty))
+        .map(|bty| {
+            let mut ty = bty.subst(tcx, substs);
+
+            // Only remap erased regions if we use them.
+            if considering_regions {
+                ty = tcx.fold_regions(ty, |mut r, current_depth| {
+                    if let ty::ReErased = r.kind() {
+                        let br = ty::BoundRegion {
+                            var: ty::BoundVar::from_u32(counter),
+                            kind: ty::BrAnon(counter, None),
+                        };
+                        counter += 1;
+                        r = tcx.mk_region(ty::ReLateBound(current_depth, br));
+                    }
+                    r
+                })
+            }
+
+            ty
+        })
+        .collect();
+    if considering_regions {
+        debug_assert!(!hidden_types.has_erased_regions());
+    }
+    let bound_vars = tcx.mk_bound_variable_kinds(bound_vars.iter().chain(
+        (num_bound_variables..counter).map(|i| ty::BoundVariableKind::Region(ty::BrAnon(i, None))),
+    ));
+    ty::Binder::bind_with_vars(hidden_types, bound_vars)
+}
diff --git a/compiler/rustc_trait_selection/src/traits/structural_match.rs b/compiler/rustc_trait_selection/src/traits/structural_match.rs
index f398fb06c18..69b965f3a38 100644
--- a/compiler/rustc_trait_selection/src/traits/structural_match.rs
+++ b/compiler/rustc_trait_selection/src/traits/structural_match.rs
@@ -101,7 +101,7 @@ impl<'tcx> TypeVisitor<'tcx> for Search<'tcx> {
             ty::Closure(..) => {
                 return ControlFlow::Break(ty);
             }
-            ty::Generator(..) | ty::GeneratorWitness(..) => {
+            ty::Generator(..) | ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => {
                 return ControlFlow::Break(ty);
             }
             ty::FnDef(..) => {
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 12d4cb4fc69..7c5e147a950 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -1,11 +1,11 @@
 use crate::infer::InferCtxt;
 use crate::traits;
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
-use rustc_span::Span;
+use rustc_span::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
+use rustc_span::{Span, DUMMY_SP};
 
 use std::iter;
 /// Returns the set of obligations needed to make `arg` well-formed.
@@ -17,7 +17,7 @@ use std::iter;
 pub fn obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     recursion_depth: usize,
     arg: GenericArg<'tcx>,
     span: Span,
@@ -75,6 +75,34 @@ pub fn obligations<'tcx>(
     Some(result)
 }
 
+/// Compute the predicates that are required for a type to be well-formed.
+///
+/// This is only intended to be used in the new solver, since it does not
+/// take into account recursion depth or proper error-reporting spans.
+pub fn unnormalized_obligations<'tcx>(
+    infcx: &InferCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    arg: GenericArg<'tcx>,
+) -> Option<Vec<traits::PredicateObligation<'tcx>>> {
+    if let ty::GenericArgKind::Lifetime(..) = arg.unpack() {
+        return Some(vec![]);
+    }
+
+    debug_assert_eq!(arg, infcx.resolve_vars_if_possible(arg));
+
+    let mut wf = WfPredicates {
+        tcx: infcx.tcx,
+        param_env,
+        body_id: CRATE_DEF_ID,
+        span: DUMMY_SP,
+        out: vec![],
+        recursion_depth: 0,
+        item: None,
+    };
+    wf.compute(arg);
+    Some(wf.out)
+}
+
 /// Returns the obligations that make this trait reference
 /// well-formed. For example, if there is a trait `Set` defined like
 /// `trait Set<K:Eq>`, then the trait reference `Foo: Set<Bar>` is WF
@@ -82,7 +110,7 @@ pub fn obligations<'tcx>(
 pub fn trait_obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     trait_pred: &ty::TraitPredicate<'tcx>,
     span: Span,
     item: &'tcx hir::Item<'tcx>,
@@ -105,7 +133,7 @@ pub fn trait_obligations<'tcx>(
 pub fn predicate_obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     predicate: ty::Predicate<'tcx>,
     span: Span,
 ) -> Vec<traits::PredicateObligation<'tcx>> {
@@ -167,7 +195,7 @@ pub fn predicate_obligations<'tcx>(
 struct WfPredicates<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     span: Span,
     out: Vec<traits::PredicateObligation<'tcx>>,
     recursion_depth: usize,
@@ -523,6 +551,7 @@ impl<'tcx> WfPredicates<'tcx> {
                 | ty::Error(_)
                 | ty::Str
                 | ty::GeneratorWitness(..)
+                | ty::GeneratorWitnessMIR(..)
                 | ty::Never
                 | ty::Param(_)
                 | ty::Bound(..)
diff --git a/compiler/rustc_traits/src/chalk/db.rs b/compiler/rustc_traits/src/chalk/db.rs
index f146de3966b..84f7e836208 100644
--- a/compiler/rustc_traits/src/chalk/db.rs
+++ b/compiler/rustc_traits/src/chalk/db.rs
@@ -269,7 +269,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
 
         let where_clauses = self.where_clauses_for(def_id, bound_vars);
 
-        let sig = self.interner.tcx.bound_fn_sig(def_id);
+        let sig = self.interner.tcx.fn_sig(def_id);
         let (inputs_and_output, iobinders, _) = crate::chalk::lowering::collect_bound_vars(
             self.interner,
             self.interner.tcx,
@@ -580,7 +580,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
     }
 
     fn is_object_safe(&self, trait_id: chalk_ir::TraitId<RustInterner<'tcx>>) -> bool {
-        self.interner.tcx.is_object_safe(trait_id.0)
+        self.interner.tcx.check_is_object_safe(trait_id.0)
     }
 
     fn hidden_opaque_type(
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 9712abb708f..3a254105162 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -343,6 +343,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Ty<RustInterner<'tcx>>> for Ty<'tcx> {
                 substs.lower_into(interner),
             ),
             ty::GeneratorWitness(_) => unimplemented!(),
+            ty::GeneratorWitnessMIR(..) => unimplemented!(),
             ty::Never => chalk_ir::TyKind::Never,
             ty::Tuple(types) => {
                 chalk_ir::TyKind::Tuple(types.len(), types.as_substs().lower_into(interner))
diff --git a/compiler/rustc_traits/src/chalk/mod.rs b/compiler/rustc_traits/src/chalk/mod.rs
index f76386fa720..13d83b92689 100644
--- a/compiler/rustc_traits/src/chalk/mod.rs
+++ b/compiler/rustc_traits/src/chalk/mod.rs
@@ -8,13 +8,10 @@ pub(crate) mod lowering;
 
 use rustc_data_structures::fx::FxHashMap;
 
-use rustc_index::vec::IndexVec;
-
 use rustc_middle::infer::canonical::{CanonicalTyVarKind, CanonicalVarKind};
 use rustc_middle::traits::ChalkRustInterner;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::subst::GenericArg;
-use rustc_middle::ty::{self, BoundVar, ParamTy, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{self, ParamTy, TyCtxt, TypeFoldable, TypeVisitable};
 
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalVarValues, Certainty, QueryRegionConstraints, QueryResponse,
@@ -100,11 +97,13 @@ pub(crate) fn evaluate_goal<'tcx>(
                          binders: chalk_ir::CanonicalVarKinds<_>| {
         use rustc_middle::infer::canonical::CanonicalVarInfo;
 
-        let mut var_values: IndexVec<BoundVar, GenericArg<'tcx>> = IndexVec::new();
         let mut reverse_param_substitutor = ReverseParamsSubstitutor::new(tcx, params);
-        subst.as_slice(interner).iter().for_each(|p| {
-            var_values.push(p.lower_into(interner).fold_with(&mut reverse_param_substitutor));
-        });
+        let var_values = tcx.mk_substs(
+            subst
+                .as_slice(interner)
+                .iter()
+                .map(|p| p.lower_into(interner).fold_with(&mut reverse_param_substitutor)),
+        );
         let variables: Vec<_> = binders
             .iter(interner)
             .map(|var| {
@@ -159,8 +158,7 @@ pub(crate) fn evaluate_goal<'tcx>(
                             max_universe: ty::UniverseIndex::from_usize(0),
                             variables: obligation.variables,
                             value: QueryResponse {
-                                var_values: CanonicalVarValues { var_values: IndexVec::new() }
-                                    .make_identity(tcx),
+                                var_values: CanonicalVarValues::dummy(),
                                 region_constraints: QueryRegionConstraints::default(),
                                 certainty: Certainty::Ambiguous,
                                 opaque_types: vec![],
diff --git a/compiler/rustc_traits/src/codegen.rs b/compiler/rustc_traits/src/codegen.rs
index c0da8a8169e..6f81d343e0f 100644
--- a/compiler/rustc_traits/src/codegen.rs
+++ b/compiler/rustc_traits/src/codegen.rs
@@ -4,7 +4,7 @@
 // general routines.
 
 use rustc_infer::infer::{DefiningAnchor, TyCtxtInferExt};
-use rustc_infer::traits::FulfillmentErrorCode;
+use rustc_infer::traits::{FulfillmentErrorCode, TraitEngineExt as _};
 use rustc_middle::traits::CodegenObligationError;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
diff --git a/compiler/rustc_traits/src/dropck_outlives.rs b/compiler/rustc_traits/src/dropck_outlives.rs
index 481b56e111e..8b7f8033bfa 100644
--- a/compiler/rustc_traits/src/dropck_outlives.rs
+++ b/compiler/rustc_traits/src/dropck_outlives.rs
@@ -164,7 +164,8 @@ fn dtorck_constraint_for_ty<'tcx>(
         | ty::Ref(..)
         | ty::FnDef(..)
         | ty::FnPtr(_)
-        | ty::GeneratorWitness(..) => {
+        | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..) => {
             // these types never have a destructor
         }
 
diff --git a/compiler/rustc_traits/src/implied_outlives_bounds.rs b/compiler/rustc_traits/src/implied_outlives_bounds.rs
index 7d2d8433c93..fe633d687d9 100644
--- a/compiler/rustc_traits/src/implied_outlives_bounds.rs
+++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs
@@ -2,13 +2,13 @@
 //! Do not call this query directory. See
 //! [`rustc_trait_selection::traits::query::type_op::implied_outlives_bounds`].
 
-use rustc_hir as hir;
 use rustc_infer::infer::canonical::{self, Canonical};
 use rustc_infer::infer::outlives::components::{push_outlives_components, Component};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::query::OutlivesBound;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_span::def_id::CRATE_DEF_ID;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
 use rustc_trait_selection::traits::query::{CanonicalTyGoal, Fallible, NoSolution};
@@ -67,9 +67,8 @@ fn compute_implied_outlives_bounds<'tcx>(
         // FIXME(@lcnr): It's not really "always fine", having fewer implied
         // bounds can be backward incompatible, e.g. #101951 was caused by
         // us not dealing with inference vars in `TypeOutlives` predicates.
-        let obligations =
-            wf::obligations(ocx.infcx, param_env, hir::CRATE_HIR_ID, 0, arg, DUMMY_SP)
-                .unwrap_or_default();
+        let obligations = wf::obligations(ocx.infcx, param_env, CRATE_DEF_ID, 0, arg, DUMMY_SP)
+            .unwrap_or_default();
 
         // While these predicates should all be implied by other parts of
         // the program, they are still relevant as they may constrain
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index f35c5e44882..27dc1625992 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -6,6 +6,7 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, FnSig, Lift, PolyFnSig, Ty, TyCtxt, TypeFoldable};
 use rustc_middle::ty::{ParamEnvAnd, Predicate};
 use rustc_middle::ty::{UserSelfTy, UserSubsts, UserType};
+use rustc_span::def_id::CRATE_DEF_ID;
 use rustc_span::{Span, DUMMY_SP};
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
 use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
@@ -76,7 +77,6 @@ fn relate_mir_and_user_ty<'tcx>(
     // FIXME(#104764): We should check well-formedness before normalization.
     let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(user_ty.into()));
     ocx.register_obligation(Obligation::new(ocx.infcx.tcx, cause, param_env, predicate));
-
     Ok(())
 }
 
@@ -111,7 +111,7 @@ fn relate_mir_and_user_substs<'tcx>(
         let span = if span == DUMMY_SP { predicate_span } else { span };
         let cause = ObligationCause::new(
             span,
-            hir::CRATE_HIR_ID,
+            CRATE_DEF_ID,
             ObligationCauseCode::AscribeUserTypeProvePredicate(predicate_span),
         );
         let instantiated_predicate =
@@ -126,7 +126,6 @@ fn relate_mir_and_user_substs<'tcx>(
         let impl_self_ty = ocx.normalize(&cause, param_env, impl_self_ty);
 
         ocx.eq(&cause, param_env, self_ty, impl_self_ty)?;
-
         let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(impl_self_ty.into()));
         ocx.register_obligation(Obligation::new(tcx, cause.clone(), param_env, predicate));
     }
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index 91a505a72fa..1c74aeca5ab 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -41,7 +41,7 @@ fn fn_sig_for_fn_abi<'tcx>(
             // We normalize the `fn_sig` again after substituting at a later point.
             let mut sig = match *ty.kind() {
                 ty::FnDef(def_id, substs) => tcx
-                    .bound_fn_sig(def_id)
+                    .fn_sig(def_id)
                     .map_bound(|fn_sig| {
                         tcx.normalize_erasing_regions(tcx.param_env(def_id), fn_sig)
                     })
@@ -244,7 +244,7 @@ fn adjust_for_rust_scalar<'tcx>(
     }
 
     // Only pointer types handled below.
-    let Scalar::Initialized { value: Pointer, valid_range} = scalar else { return };
+    let Scalar::Initialized { value: Pointer(_), valid_range} = scalar else { return };
 
     if !valid_range.contains(0) {
         attrs.set(ArgAttribute::NonNull);
@@ -479,7 +479,7 @@ fn fn_abi_adjust_for_abi<'tcx>(
             }
 
             let size = arg.layout.size;
-            if arg.layout.is_unsized() || size > Pointer.size(cx) {
+            if arg.layout.is_unsized() || size > Pointer(AddressSpace::DATA).size(cx) {
                 arg.make_indirect();
             } else {
                 // We want to pass small aggregates as immediates, but using
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs
index 7a24645803c..961c04974e5 100644
--- a/compiler/rustc_ty_utils/src/implied_bounds.rs
+++ b/compiler/rustc_ty_utils/src/implied_bounds.rs
@@ -9,12 +9,12 @@ pub fn provide(providers: &mut ty::query::Providers) {
 fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Ty<'_>> {
     match tcx.def_kind(def_id) {
         DefKind::Fn => {
-            let sig = tcx.fn_sig(def_id);
+            let sig = tcx.fn_sig(def_id).subst_identity();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id, sig);
             liberated_sig.inputs_and_output
         }
         DefKind::AssocFn => {
-            let sig = tcx.fn_sig(def_id);
+            let sig = tcx.fn_sig(def_id).subst_identity();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id, sig);
             let mut assumed_wf_types: Vec<_> =
                 tcx.assumed_wf_types(tcx.parent(def_id)).as_slice().into();
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 6aa016133ca..378cd5a99ed 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -134,7 +134,7 @@ fn layout_of_uncached<'tcx>(
             ty::FloatTy::F64 => F64,
         }),
         ty::FnPtr(_) => {
-            let mut ptr = scalar_unit(Pointer);
+            let mut ptr = scalar_unit(Pointer(dl.instruction_address_space));
             ptr.valid_range_mut().start = 1;
             tcx.intern_layout(LayoutS::scalar(cx, ptr))
         }
@@ -144,7 +144,7 @@ fn layout_of_uncached<'tcx>(
 
         // Potentially-wide pointers.
         ty::Ref(_, pointee, _) | ty::RawPtr(ty::TypeAndMut { ty: pointee, .. }) => {
-            let mut data_ptr = scalar_unit(Pointer);
+            let mut data_ptr = scalar_unit(Pointer(AddressSpace::DATA));
             if !ty.is_unsafe_ptr() {
                 data_ptr.valid_range_mut().start = 1;
             }
@@ -178,7 +178,7 @@ fn layout_of_uncached<'tcx>(
                     }
                     ty::Slice(_) | ty::Str => scalar_unit(Int(dl.ptr_sized_integer(), false)),
                     ty::Dynamic(..) => {
-                        let mut vtable = scalar_unit(Pointer);
+                        let mut vtable = scalar_unit(Pointer(AddressSpace::DATA));
                         vtable.valid_range_mut().start = 1;
                         vtable
                     }
@@ -195,7 +195,7 @@ fn layout_of_uncached<'tcx>(
         ty::Dynamic(_, _, ty::DynStar) => {
             let mut data = scalar_unit(Int(dl.ptr_sized_integer(), false));
             data.valid_range_mut().start = 0;
-            let mut vtable = scalar_unit(Pointer);
+            let mut vtable = scalar_unit(Pointer(AddressSpace::DATA));
             vtable.valid_range_mut().start = 1;
             tcx.intern_layout(cx.scalar_pair(data, vtable))
         }
@@ -470,7 +470,10 @@ fn layout_of_uncached<'tcx>(
             return Err(LayoutError::Unknown(ty));
         }
 
-        ty::Placeholder(..) | ty::GeneratorWitness(..) | ty::Infer(_) => {
+        ty::Placeholder(..)
+        | ty::GeneratorWitness(..)
+        | ty::GeneratorWitnessMIR(..)
+        | ty::Infer(_) => {
             bug!("Layout::compute: unexpected type `{}`", ty)
         }
 
@@ -640,7 +643,7 @@ fn generator_layout<'tcx>(
 
     let promoted_layouts = ineligible_locals
         .iter()
-        .map(|local| subst_field(info.field_tys[local]))
+        .map(|local| subst_field(info.field_tys[local].ty))
         .map(|ty| tcx.mk_maybe_uninit(ty))
         .map(|ty| cx.layout_of(ty));
     let prefix_layouts = substs
@@ -710,7 +713,7 @@ fn generator_layout<'tcx>(
                     Assigned(_) => bug!("assignment does not match variant"),
                     Ineligible(_) => false,
                 })
-                .map(|local| subst_field(info.field_tys[*local]));
+                .map(|local| subst_field(info.field_tys[*local].ty));
 
             let mut variant = univariant_uninterned(
                 cx,
diff --git a/compiler/rustc_ty_utils/src/needs_drop.rs b/compiler/rustc_ty_utils/src/needs_drop.rs
index 0df060fc5fb..cd1475391a4 100644
--- a/compiler/rustc_ty_utils/src/needs_drop.rs
+++ b/compiler/rustc_ty_utils/src/needs_drop.rs
@@ -109,6 +109,13 @@ where
 
             for component in components {
                 match *component.kind() {
+                    // The information required to determine whether a generator has drop is
+                    // computed on MIR, while this very method is used to build MIR.
+                    // To avoid cycles, we consider that generators always require drop.
+                    ty::Generator(..) if tcx.sess.opts.unstable_opts.drop_tracking_mir => {
+                        return Some(Err(AlwaysRequiresDrop));
+                    }
+
                     _ if component.is_copy_modulo_regions(tcx, self.param_env) => (),
 
                     ty::Closure(_, substs) => {
diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs
index eb5454bf263..b5005c1d8d8 100644
--- a/compiler/rustc_ty_utils/src/ty.rs
+++ b/compiler/rustc_ty_utils/src/ty.rs
@@ -1,8 +1,9 @@
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
+use rustc_index::bit_set::BitSet;
 use rustc_middle::ty::{self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt};
 use rustc_session::config::TraitSolver;
+use rustc_span::def_id::{DefId, CRATE_DEF_ID};
 use rustc_trait_selection::traits;
 
 fn sized_constraint_for_ty<'tcx>(
@@ -16,7 +17,13 @@ fn sized_constraint_for_ty<'tcx>(
         Bool | Char | Int(..) | Uint(..) | Float(..) | RawPtr(..) | Ref(..) | FnDef(..)
         | FnPtr(_) | Array(..) | Closure(..) | Generator(..) | Never => vec![],
 
-        Str | Dynamic(..) | Slice(_) | Foreign(..) | Error(_) | GeneratorWitness(..) => {
+        Str
+        | Dynamic(..)
+        | Slice(_)
+        | Foreign(..)
+        | Error(_)
+        | GeneratorWitness(..)
+        | GeneratorWitnessMIR(..) => {
             // these are never sized - return the target type
             vec![ty]
         }
@@ -208,14 +215,7 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
         constness,
     );
 
-    let body_id =
-        local_did.and_then(|id| tcx.hir().maybe_body_owned_by(id).map(|body| body.hir_id));
-    let body_id = match body_id {
-        Some(id) => id,
-        None if hir_id.is_some() => hir_id.unwrap(),
-        _ => hir::CRATE_HIR_ID,
-    };
-
+    let body_id = local_did.unwrap_or(CRATE_DEF_ID);
     let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
     traits::normalize_param_env_or_error(tcx, unnormalized_env, cause)
 }
@@ -306,7 +306,7 @@ fn well_formed_types_in_env(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Predica
         // In an fn, we assume that the arguments and all their constituents are
         // well-formed.
         NodeKind::Fn => {
-            let fn_sig = tcx.fn_sig(def_id);
+            let fn_sig = tcx.fn_sig(def_id).subst_identity();
             let fn_sig = tcx.liberate_late_bound_regions(def_id, fn_sig);
 
             inputs.extend(fn_sig.inputs().iter().flat_map(|ty| ty.walk()));
@@ -407,6 +407,56 @@ fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
     node.fn_sig().map_or(hir::IsAsync::NotAsync, |sig| sig.header.asyncness)
 }
 
+fn unsizing_params_for_adt<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> BitSet<u32> {
+    let def = tcx.adt_def(def_id);
+    let num_params = tcx.generics_of(def_id).count();
+
+    let maybe_unsizing_param_idx = |arg: ty::GenericArg<'tcx>| match arg.unpack() {
+        ty::GenericArgKind::Type(ty) => match ty.kind() {
+            ty::Param(p) => Some(p.index),
+            _ => None,
+        },
+
+        // We can't unsize a lifetime
+        ty::GenericArgKind::Lifetime(_) => None,
+
+        ty::GenericArgKind::Const(ct) => match ct.kind() {
+            ty::ConstKind::Param(p) => Some(p.index),
+            _ => None,
+        },
+    };
+
+    // FIXME(eddyb) cache this (including computing `unsizing_params`)
+    // by putting it in a query; it would only need the `DefId` as it
+    // looks at declared field types, not anything substituted.
+
+    // The last field of the structure has to exist and contain type/const parameters.
+    let Some((tail_field, prefix_fields)) =
+        def.non_enum_variant().fields.split_last() else
+    {
+        return BitSet::new_empty(num_params);
+    };
+
+    let mut unsizing_params = BitSet::new_empty(num_params);
+    for arg in tcx.bound_type_of(tail_field.did).subst_identity().walk() {
+        if let Some(i) = maybe_unsizing_param_idx(arg) {
+            unsizing_params.insert(i);
+        }
+    }
+
+    // Ensure none of the other fields mention the parameters used
+    // in unsizing.
+    for field in prefix_fields {
+        for arg in tcx.bound_type_of(field.did).subst_identity().walk() {
+            if let Some(i) = maybe_unsizing_param_idx(arg) {
+                unsizing_params.remove(i);
+            }
+        }
+    }
+
+    unsizing_params
+}
+
 pub fn provide(providers: &mut ty::query::Providers) {
     *providers = ty::query::Providers {
         asyncness,
@@ -416,6 +466,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
         instance_def_size_estimate,
         issue33140_self_ty,
         impl_defaultness,
+        unsizing_params_for_adt,
         ..*providers
     };
 }
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index 44004cb0be1..d5de457a82c 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -265,6 +265,9 @@ bitflags! {
 
         /// Does this value have `InferConst::Fresh`?
         const HAS_CT_FRESH                = 1 << 21;
+
+        /// Does this have `Generator` or `GeneratorWitness`?
+        const HAS_TY_GENERATOR            = 1 << 22;
     }
 }
 
diff --git a/compiler/rustc_type_ir/src/sty.rs b/compiler/rustc_type_ir/src/sty.rs
index 5f29588ae4d..e7bb3055373 100644
--- a/compiler/rustc_type_ir/src/sty.rs
+++ b/compiler/rustc_type_ir/src/sty.rs
@@ -160,6 +160,32 @@ pub enum TyKind<I: Interner> {
     /// ```
     GeneratorWitness(I::BinderListTy),
 
+    /// A type representing the types stored inside a generator.
+    /// This should only appear as part of the `GeneratorSubsts`.
+    ///
+    /// Unlike upvars, the witness can reference lifetimes from
+    /// inside of the generator itself. To deal with them in
+    /// the type of the generator, we convert them to higher ranked
+    /// lifetimes bound by the witness itself.
+    ///
+    /// This variant is only using when `drop_tracking_mir` is set.
+    /// This contains the `DefId` and the `SubstRef` of the generator.
+    /// The actual witness types are computed on MIR by the `mir_generator_witnesses` query.
+    ///
+    /// Looking at the following example, the witness for this generator
+    /// may end up as something like `for<'a> [Vec<i32>, &'a Vec<i32>]`:
+    ///
+    /// ```ignore UNSOLVED (ask @compiler-errors, should this error? can we just swap the yields?)
+    /// #![feature(generators)]
+    /// |a| {
+    ///     let x = &vec![3];
+    ///     yield a;
+    ///     yield x[0];
+    /// }
+    /// # ;
+    /// ```
+    GeneratorWitnessMIR(I::DefId, I::SubstsRef),
+
     /// The never type `!`.
     Never,
 
@@ -241,6 +267,7 @@ const fn tykind_discriminant<I: Interner>(value: &TyKind<I>) -> usize {
         Placeholder(_) => 23,
         Infer(_) => 24,
         Error(_) => 25,
+        GeneratorWitnessMIR(_, _) => 26,
     }
 }
 
@@ -266,6 +293,7 @@ impl<I: Interner> Clone for TyKind<I> {
             Closure(d, s) => Closure(d.clone(), s.clone()),
             Generator(d, s, m) => Generator(d.clone(), s.clone(), m.clone()),
             GeneratorWitness(g) => GeneratorWitness(g.clone()),
+            GeneratorWitnessMIR(d, s) => GeneratorWitnessMIR(d.clone(), s.clone()),
             Never => Never,
             Tuple(t) => Tuple(t.clone()),
             Alias(k, p) => Alias(*k, p.clone()),
@@ -303,6 +331,10 @@ impl<I: Interner> PartialEq for TyKind<I> {
                     a_d == b_d && a_s == b_s && a_m == b_m
                 }
                 (GeneratorWitness(a_g), GeneratorWitness(b_g)) => a_g == b_g,
+                (
+                    &GeneratorWitnessMIR(ref a_d, ref a_s),
+                    &GeneratorWitnessMIR(ref b_d, ref b_s),
+                ) => a_d == b_d && a_s == b_s,
                 (Tuple(a_t), Tuple(b_t)) => a_t == b_t,
                 (Alias(a_i, a_p), Alias(b_i, b_p)) => a_i == b_i && a_p == b_p,
                 (Param(a_p), Param(b_p)) => a_p == b_p,
@@ -360,6 +392,13 @@ impl<I: Interner> Ord for TyKind<I> {
                     a_d.cmp(b_d).then_with(|| a_s.cmp(b_s).then_with(|| a_m.cmp(b_m)))
                 }
                 (GeneratorWitness(a_g), GeneratorWitness(b_g)) => a_g.cmp(b_g),
+                (
+                    &GeneratorWitnessMIR(ref a_d, ref a_s),
+                    &GeneratorWitnessMIR(ref b_d, ref b_s),
+                ) => match Ord::cmp(a_d, b_d) {
+                    Ordering::Equal => Ord::cmp(a_s, b_s),
+                    cmp => cmp,
+                },
                 (Tuple(a_t), Tuple(b_t)) => a_t.cmp(b_t),
                 (Alias(a_i, a_p), Alias(b_i, b_p)) => a_i.cmp(b_i).then_with(|| a_p.cmp(b_p)),
                 (Param(a_p), Param(b_p)) => a_p.cmp(b_p),
@@ -421,6 +460,10 @@ impl<I: Interner> hash::Hash for TyKind<I> {
                 m.hash(state)
             }
             GeneratorWitness(g) => g.hash(state),
+            GeneratorWitnessMIR(d, s) => {
+                d.hash(state);
+                s.hash(state);
+            }
             Tuple(t) => t.hash(state),
             Alias(i, p) => {
                 i.hash(state);
@@ -461,6 +504,7 @@ impl<I: Interner> fmt::Debug for TyKind<I> {
             Closure(d, s) => f.debug_tuple_field2_finish("Closure", d, s),
             Generator(d, s, m) => f.debug_tuple_field3_finish("Generator", d, s, m),
             GeneratorWitness(g) => f.debug_tuple_field1_finish("GeneratorWitness", g),
+            GeneratorWitnessMIR(d, s) => f.debug_tuple_field2_finish("GeneratorWitnessMIR", d, s),
             Never => f.write_str("Never"),
             Tuple(t) => f.debug_tuple_field1_finish("Tuple", t),
             Alias(i, a) => f.debug_tuple_field2_finish("Alias", i, a),
@@ -559,6 +603,10 @@ where
             GeneratorWitness(b) => e.emit_enum_variant(disc, |e| {
                 b.encode(e);
             }),
+            GeneratorWitnessMIR(def_id, substs) => e.emit_enum_variant(disc, |e| {
+                def_id.encode(e);
+                substs.encode(e);
+            }),
             Never => e.emit_enum_variant(disc, |_| {}),
             Tuple(substs) => e.emit_enum_variant(disc, |e| {
                 substs.encode(e);
@@ -641,6 +689,7 @@ where
             23 => Placeholder(Decodable::decode(d)),
             24 => Infer(Decodable::decode(d)),
             25 => Error(Decodable::decode(d)),
+            26 => GeneratorWitnessMIR(Decodable::decode(d), Decodable::decode(d)),
             _ => panic!(
                 "{}",
                 format!(
@@ -742,6 +791,10 @@ where
             GeneratorWitness(b) => {
                 b.hash_stable(__hcx, __hasher);
             }
+            GeneratorWitnessMIR(def_id, substs) => {
+                def_id.hash_stable(__hcx, __hasher);
+                substs.hash_stable(__hcx, __hasher);
+            }
             Never => {}
             Tuple(substs) => {
                 substs.hash_stable(__hcx, __hasher);
diff --git a/config.toml.example b/config.toml.example
index 5e1d2f2e314..85f058f3664 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -233,6 +233,9 @@ changelog-seen = 2
 # and generated in already-minified form from the beginning.
 #docs-minification = true
 
+# Flag to specify whether private items should be included in the library docs.
+#library-docs-private-items = false
+
 # Indicate whether the compiler should be documented in addition to the standard
 # library and facade crates.
 #compiler-docs = false
@@ -285,11 +288,24 @@ changelog-seen = 2
 # be built if `extended = true`.
 #extended = false
 
-# Installs chosen set of extended tools if `extended = true`. By default builds
-# all extended tools except `rust-demangler`, unless the target is also being
-# built with `profiler = true`. If chosen tool failed to build the installation
-# fails. If `extended = false`, this option is ignored.
-#tools = ["cargo", "rls", "clippy", "rustfmt", "analysis", "src"] # + "rust-demangler" if `profiler`
+# Set of tools to be included in the installation.
+#
+# If `extended = false`, the only one of these built by default is rustdoc.
+#
+# If `extended = true`, they're all included, with the exception of
+# rust-demangler which additionally requires `profiler = true` to be set.
+#
+# If any enabled tool fails to build, the installation fails.
+#tools = [
+#    "cargo",
+#    "clippy",
+#    "rustdoc",
+#    "rustfmt",
+#    "rust-analyzer",
+#    "analysis",
+#    "src",
+#    "rust-demangler",  # if profiler = true
+#]
 
 # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose
 #verbose = 0
diff --git a/library/alloc/src/boxed/thin.rs b/library/alloc/src/boxed/thin.rs
index c1a82e452f6..ad48315fd70 100644
--- a/library/alloc/src/boxed/thin.rs
+++ b/library/alloc/src/boxed/thin.rs
@@ -48,7 +48,7 @@ unsafe impl<T: ?Sized + Sync> Sync for ThinBox<T> {}
 
 #[unstable(feature = "thin_box", issue = "92791")]
 impl<T> ThinBox<T> {
-    /// Moves a type to the heap with its `Metadata` stored in the heap allocation instead of on
+    /// Moves a type to the heap with its [`Metadata`] stored in the heap allocation instead of on
     /// the stack.
     ///
     /// # Examples
@@ -59,6 +59,8 @@ impl<T> ThinBox<T> {
     ///
     /// let five = ThinBox::new(5);
     /// ```
+    ///
+    /// [`Metadata`]: core::ptr::Pointee::Metadata
     #[cfg(not(no_global_oom_handling))]
     pub fn new(value: T) -> Self {
         let meta = ptr::metadata(&value);
@@ -69,7 +71,7 @@ impl<T> ThinBox<T> {
 
 #[unstable(feature = "thin_box", issue = "92791")]
 impl<Dyn: ?Sized> ThinBox<Dyn> {
-    /// Moves a type to the heap with its `Metadata` stored in the heap allocation instead of on
+    /// Moves a type to the heap with its [`Metadata`] stored in the heap allocation instead of on
     /// the stack.
     ///
     /// # Examples
@@ -80,6 +82,8 @@ impl<Dyn: ?Sized> ThinBox<Dyn> {
     ///
     /// let thin_slice = ThinBox::<[i32]>::new_unsize([1, 2, 3, 4]);
     /// ```
+    ///
+    /// [`Metadata`]: core::ptr::Pointee::Metadata
     #[cfg(not(no_global_oom_handling))]
     pub fn new_unsize<T>(value: T) -> Self
     where
diff --git a/library/alloc/src/collections/btree/borrow.rs b/library/alloc/src/collections/btree/borrow.rs
index 016f139a501..000b9bd0fab 100644
--- a/library/alloc/src/collections/btree/borrow.rs
+++ b/library/alloc/src/collections/btree/borrow.rs
@@ -41,6 +41,28 @@ impl<'a, T> DormantMutRef<'a, T> {
         // SAFETY: our own safety conditions imply this reference is again unique.
         unsafe { &mut *self.ptr.as_ptr() }
     }
+
+    /// Borrows a new mutable reference from the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn reborrow(&mut self) -> &'a mut T {
+        // SAFETY: our own safety conditions imply this reference is again unique.
+        unsafe { &mut *self.ptr.as_ptr() }
+    }
+
+    /// Borrows a new shared reference from the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn reborrow_shared(&self) -> &'a T {
+        // SAFETY: our own safety conditions imply this reference is again unique.
+        unsafe { &*self.ptr.as_ptr() }
+    }
 }
 
 #[cfg(test)]
diff --git a/library/alloc/src/collections/btree/map.rs b/library/alloc/src/collections/btree/map.rs
index 1d9c4460ec9..386cd1a1657 100644
--- a/library/alloc/src/collections/btree/map.rs
+++ b/library/alloc/src/collections/btree/map.rs
@@ -6,7 +6,7 @@ use core::hash::{Hash, Hasher};
 use core::iter::{FromIterator, FusedIterator};
 use core::marker::PhantomData;
 use core::mem::{self, ManuallyDrop};
-use core::ops::{Index, RangeBounds};
+use core::ops::{Bound, Index, RangeBounds};
 use core::ptr;
 
 use crate::alloc::{Allocator, Global};
@@ -15,7 +15,7 @@ use super::borrow::DormantMutRef;
 use super::dedup_sorted_iter::DedupSortedIter;
 use super::navigate::{LazyLeafRange, LeafRange};
 use super::node::{self, marker, ForceResult::*, Handle, NodeRef, Root};
-use super::search::SearchResult::*;
+use super::search::{SearchBound, SearchResult::*};
 use super::set_val::SetValZST;
 
 mod entry;
@@ -2422,6 +2422,732 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     pub const fn is_empty(&self) -> bool {
         self.len() == 0
     }
+
+    /// Returns a [`Cursor`] pointing at the first element that is above the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the first
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.lower_bound(Bound::Excluded(&2));
+    /// assert_eq!(cursor.key(), Some(&3));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let root_node = match self.root.as_ref() {
+            None => return Cursor { current: None, root: None },
+            Some(root) => root.reborrow(),
+        };
+        let edge = root_node.lower_bound(SearchBound::from_range(bound));
+        Cursor { current: edge.next_kv().ok(), root: self.root.as_ref() }
+    }
+
+    /// Returns a [`CursorMut`] pointing at the first element that is above the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the first
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.lower_bound_mut(Bound::Excluded(&2));
+    /// assert_eq!(cursor.key(), Some(&3));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let (root, dormant_root) = DormantMutRef::new(&mut self.root);
+        let root_node = match root.as_mut() {
+            None => {
+                return CursorMut {
+                    current: None,
+                    root: dormant_root,
+                    length: &mut self.length,
+                    alloc: &mut *self.alloc,
+                };
+            }
+            Some(root) => root.borrow_mut(),
+        };
+        let edge = root_node.lower_bound(SearchBound::from_range(bound));
+        CursorMut {
+            current: edge.next_kv().ok(),
+            root: dormant_root,
+            length: &mut self.length,
+            alloc: &mut *self.alloc,
+        }
+    }
+
+    /// Returns a [`Cursor`] pointing at the last element that is below the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the last
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.upper_bound(Bound::Excluded(&3));
+    /// assert_eq!(cursor.key(), Some(&2));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let root_node = match self.root.as_ref() {
+            None => return Cursor { current: None, root: None },
+            Some(root) => root.reborrow(),
+        };
+        let edge = root_node.upper_bound(SearchBound::from_range(bound));
+        Cursor { current: edge.next_back_kv().ok(), root: self.root.as_ref() }
+    }
+
+    /// Returns a [`CursorMut`] pointing at the last element that is below the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the last
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.upper_bound_mut(Bound::Excluded(&3));
+    /// assert_eq!(cursor.key(), Some(&2));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let (root, dormant_root) = DormantMutRef::new(&mut self.root);
+        let root_node = match root.as_mut() {
+            None => {
+                return CursorMut {
+                    current: None,
+                    root: dormant_root,
+                    length: &mut self.length,
+                    alloc: &mut *self.alloc,
+                };
+            }
+            Some(root) => root.borrow_mut(),
+        };
+        let edge = root_node.upper_bound(SearchBound::from_range(bound));
+        CursorMut {
+            current: edge.next_back_kv().ok(),
+            root: dormant_root,
+            length: &mut self.length,
+            alloc: &mut *self.alloc,
+        }
+    }
+}
+
+/// A cursor over a `BTreeMap`.
+///
+/// A `Cursor` is like an iterator, except that it can freely seek back-and-forth.
+///
+/// Cursors always point to an element in the tree, and index in a logically circular way.
+/// To accommodate this, there is a "ghost" non-element that yields `None` between the last and
+/// first elements of the tree.
+///
+/// A `Cursor` is created with the [`BTreeMap::lower_bound`] and [`BTreeMap::upper_bound`] methods.
+#[unstable(feature = "btree_cursors", issue = "107540")]
+pub struct Cursor<'a, K: 'a, V: 'a> {
+    current: Option<Handle<NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal>, marker::KV>>,
+    root: Option<&'a node::Root<K, V>>,
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K, V> Clone for Cursor<'_, K, V> {
+    fn clone(&self) -> Self {
+        let Cursor { current, root } = *self;
+        Cursor { current, root }
+    }
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K: Debug, V: Debug> Debug for Cursor<'_, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("Cursor").field(&self.key_value()).finish()
+    }
+}
+
+/// A cursor over a `BTreeMap` with editing operations.
+///
+/// A `Cursor` is like an iterator, except that it can freely seek back-and-forth, and can
+/// safely mutate the tree during iteration. This is because the lifetime of its yielded
+/// references is tied to its own lifetime, instead of just the underlying tree. This means
+/// cursors cannot yield multiple elements at once.
+///
+/// Cursors always point to an element in the tree, and index in a logically circular way.
+/// To accommodate this, there is a "ghost" non-element that yields `None` between the last and
+/// first elements of the tree.
+///
+/// A `Cursor` is created with the [`BTreeMap::lower_bound_mut`] and [`BTreeMap::upper_bound_mut`]
+/// methods.
+#[unstable(feature = "btree_cursors", issue = "107540")]
+pub struct CursorMut<
+    'a,
+    K: 'a,
+    V: 'a,
+    #[unstable(feature = "allocator_api", issue = "32838")] A = Global,
+> {
+    current: Option<Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>>,
+    root: DormantMutRef<'a, Option<node::Root<K, V>>>,
+    length: &'a mut usize,
+    alloc: &'a mut A,
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K: Debug, V: Debug, A> Debug for CursorMut<'_, K, V, A> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("CursorMut").field(&self.key_value()).finish()
+    }
+}
+
+impl<'a, K, V> Cursor<'a, K, V> {
+    /// Moves the cursor to the next element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_next(&mut self) {
+        match self.current.take() {
+            None => {
+                self.current = self.root.and_then(|root| {
+                    root.reborrow().first_leaf_edge().forget_node_type().right_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_leaf_edge().next_kv().ok();
+            }
+        }
+    }
+
+    /// Moves the cursor to the previous element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_prev(&mut self) {
+        match self.current.take() {
+            None => {
+                self.current = self.root.and_then(|root| {
+                    root.reborrow().last_leaf_edge().forget_node_type().left_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_back_leaf_edge().next_back_kv().ok();
+            }
+        }
+    }
+
+    /// Returns a reference to the key of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key(&self) -> Option<&'a K> {
+        self.current.as_ref().map(|current| current.into_kv().0)
+    }
+
+    /// Returns a reference to the value of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value(&self) -> Option<&'a V> {
+        self.current.as_ref().map(|current| current.into_kv().1)
+    }
+
+    /// Returns a reference to the key and value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value(&self) -> Option<(&'a K, &'a V)> {
+        self.current.as_ref().map(|current| current.into_kv())
+    }
+
+    /// Returns a reference to the next element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_next(&self) -> Option<(&'a K, &'a V)> {
+        let mut next = self.clone();
+        next.move_next();
+        next.current.as_ref().map(|current| current.into_kv())
+    }
+
+    /// Returns a reference to the previous element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_prev(&self) -> Option<(&'a K, &'a V)> {
+        let mut prev = self.clone();
+        prev.move_prev();
+        prev.current.as_ref().map(|current| current.into_kv())
+    }
+}
+
+impl<'a, K, V, A> CursorMut<'a, K, V, A> {
+    /// Moves the cursor to the next element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_next(&mut self) {
+        match self.current.take() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                self.current = unsafe { self.root.reborrow() }.as_mut().and_then(|root| {
+                    root.borrow_mut().first_leaf_edge().forget_node_type().right_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_leaf_edge().next_kv().ok();
+            }
+        }
+    }
+
+    /// Moves the cursor to the previous element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_prev(&mut self) {
+        match self.current.take() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                self.current = unsafe { self.root.reborrow() }.as_mut().and_then(|root| {
+                    root.borrow_mut().last_leaf_edge().forget_node_type().left_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_back_leaf_edge().next_back_kv().ok();
+            }
+        }
+    }
+
+    /// Returns a reference to the key of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key(&self) -> Option<&K> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv().0)
+    }
+
+    /// Returns a reference to the value of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value(&self) -> Option<&V> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv().1)
+    }
+
+    /// Returns a reference to the key and value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value(&self) -> Option<(&K, &V)> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv())
+    }
+
+    /// Returns a mutable reference to the value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value_mut(&mut self) -> Option<&mut V> {
+        self.current.as_mut().map(|current| current.kv_mut().1)
+    }
+
+    /// Returns a reference to the key and mutable reference to the value of the
+    /// element that the cursor is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value_mut(&mut self) -> Option<(&K, &mut V)> {
+        self.current.as_mut().map(|current| {
+            let (k, v) = current.kv_mut();
+            (&*k, v)
+        })
+    }
+
+    /// Returns a mutable reference to the of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    ///
+    /// # Safety
+    ///
+    /// This can be used to modify the key, but you must ensure that the
+    /// `BTreeMap` invariants are maintained. Specifically:
+    ///
+    /// * The key must remain unique within the tree.
+    /// * The key must remain in sorted order with regards to other elements in
+    ///   the tree.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn key_mut_unchecked(&mut self) -> Option<&mut K> {
+        self.current.as_mut().map(|current| current.kv_mut().0)
+    }
+
+    /// Returns a reference to the key and value of the next element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_next(&mut self) -> Option<(&K, &mut V)> {
+        let (k, v) = match self.current {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                unsafe { self.root.reborrow() }
+                    .as_mut()?
+                    .borrow_mut()
+                    .first_leaf_edge()
+                    .next_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+            // SAFETY: We're not using this to mutate the tree.
+            Some(ref mut current) => {
+                unsafe { current.reborrow_mut() }.next_leaf_edge().next_kv().ok()?.into_kv_valmut()
+            }
+        };
+        Some((k, v))
+    }
+
+    /// Returns a reference to the key and value of the previous element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_prev(&mut self) -> Option<(&K, &mut V)> {
+        let (k, v) = match self.current.as_mut() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                unsafe { self.root.reborrow() }
+                    .as_mut()?
+                    .borrow_mut()
+                    .first_leaf_edge()
+                    .next_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+            Some(current) => {
+                // SAFETY: We're not using this to mutate the tree.
+                unsafe { current.reborrow_mut() }
+                    .next_back_leaf_edge()
+                    .next_back_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+        };
+        Some((k, v))
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorMut`, which means it cannot outlive the `CursorMut` and that the
+    /// `CursorMut` is frozen for the lifetime of the `Cursor`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn as_cursor(&self) -> Cursor<'_, K, V> {
+        Cursor {
+            // SAFETY: The tree is immutable while the cursor exists.
+            root: unsafe { self.root.reborrow_shared().as_ref() },
+            current: self.current.as_ref().map(|current| current.reborrow()),
+        }
+    }
+}
+
+// Now the tree editing operations
+impl<'a, K: Ord, V, A: Allocator + Clone> CursorMut<'a, K, V, A> {
+    /// Inserts a new element into the `BTreeMap` after the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the front of the `BTreeMap`.
+    ///
+    /// # Safety
+    ///
+    /// You must ensure that the `BTreeMap` invariants are maintained.
+    /// Specifically:
+    ///
+    /// * The key of the newly inserted element must be unique in the tree.
+    /// * All keys in the tree must remain in sorted order.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn insert_after_unchecked(&mut self, key: K, value: V) {
+        let edge = match self.current.take() {
+            None => {
+                // SAFETY: We have no other reference to the tree.
+                match unsafe { self.root.reborrow() } {
+                    root @ None => {
+                        // Tree is empty, allocate a new root.
+                        let mut node = NodeRef::new_leaf(self.alloc.clone());
+                        node.borrow_mut().push(key, value);
+                        *root = Some(node.forget_type());
+                        *self.length += 1;
+                        return;
+                    }
+                    Some(root) => root.borrow_mut().first_leaf_edge(),
+                }
+            }
+            Some(current) => current.next_leaf_edge(),
+        };
+
+        let handle = edge.insert_recursing(key, value, self.alloc.clone(), |ins| {
+            drop(ins.left);
+            // SAFETY: The handle to the newly inserted value is always on a
+            // leaf node, so adding a new root node doesn't invalidate it.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.push_internal_level(self.alloc.clone()).push(ins.kv.0, ins.kv.1, ins.right)
+        });
+        self.current = handle.left_edge().next_back_kv().ok();
+        *self.length += 1;
+    }
+
+    /// Inserts a new element into the `BTreeMap` before the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the end of the `BTreeMap`.
+    ///
+    /// # Safety
+    ///
+    /// You must ensure that the `BTreeMap` invariants are maintained.
+    /// Specifically:
+    ///
+    /// * The key of the newly inserted element must be unique in the tree.
+    /// * All keys in the tree must remain in sorted order.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn insert_before_unchecked(&mut self, key: K, value: V) {
+        let edge = match self.current.take() {
+            None => {
+                // SAFETY: We have no other reference to the tree.
+                match unsafe { self.root.reborrow() } {
+                    root @ None => {
+                        // Tree is empty, allocate a new root.
+                        let mut node = NodeRef::new_leaf(self.alloc.clone());
+                        node.borrow_mut().push(key, value);
+                        *root = Some(node.forget_type());
+                        *self.length += 1;
+                        return;
+                    }
+                    Some(root) => root.borrow_mut().last_leaf_edge(),
+                }
+            }
+            Some(current) => current.next_back_leaf_edge(),
+        };
+
+        let handle = edge.insert_recursing(key, value, self.alloc.clone(), |ins| {
+            drop(ins.left);
+            // SAFETY: The handle to the newly inserted value is always on a
+            // leaf node, so adding a new root node doesn't invalidate it.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.push_internal_level(self.alloc.clone()).push(ins.kv.0, ins.kv.1, ins.right)
+        });
+        self.current = handle.right_edge().next_kv().ok();
+        *self.length += 1;
+    }
+
+    /// Inserts a new element into the `BTreeMap` after the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the front of the `BTreeMap`.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if:
+    /// - the given key compares less than or equal to the current element (if
+    ///   any).
+    /// - the given key compares greater than or equal to the next element (if
+    ///   any).
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn insert_after(&mut self, key: K, value: V) {
+        if let Some(current) = self.key() {
+            if &key <= current {
+                panic!("key must be ordered above the current element");
+            }
+        }
+        if let Some((next, _)) = self.peek_prev() {
+            if &key >= next {
+                panic!("key must be ordered below the next element");
+            }
+        }
+        unsafe {
+            self.insert_after_unchecked(key, value);
+        }
+    }
+
+    /// Inserts a new element into the `BTreeMap` before the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the end of the `BTreeMap`.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if:
+    /// - the given key compares greater than or equal to the current element
+    ///   (if any).
+    /// - the given key compares less than or equal to the previous element (if
+    ///   any).
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn insert_before(&mut self, key: K, value: V) {
+        if let Some(current) = self.key() {
+            if &key >= current {
+                panic!("key must be ordered below the current element");
+            }
+        }
+        if let Some((prev, _)) = self.peek_prev() {
+            if &key <= prev {
+                panic!("key must be ordered above the previous element");
+            }
+        }
+        unsafe {
+            self.insert_before_unchecked(key, value);
+        }
+    }
+
+    /// Removes the current element from the `BTreeMap`.
+    ///
+    /// The element that was removed is returned, and the cursor is
+    /// moved to point to the next element in the `BTreeMap`.
+    ///
+    /// If the cursor is currently pointing to the "ghost" non-element then no element
+    /// is removed and `None` is returned. The cursor is not moved in this case.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn remove_current(&mut self) -> Option<(K, V)> {
+        let current = self.current.take()?;
+        let mut emptied_internal_root = false;
+        let (kv, pos) =
+            current.remove_kv_tracking(|| emptied_internal_root = true, self.alloc.clone());
+        self.current = pos.next_kv().ok();
+        *self.length -= 1;
+        if emptied_internal_root {
+            // SAFETY: This is safe since current does not point within the now
+            // empty root node.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.pop_internal_level(self.alloc.clone());
+        }
+        Some(kv)
+    }
+
+    /// Removes the current element from the `BTreeMap`.
+    ///
+    /// The element that was removed is returned, and the cursor is
+    /// moved to point to the previous element in the `BTreeMap`.
+    ///
+    /// If the cursor is currently pointing to the "ghost" non-element then no element
+    /// is removed and `None` is returned. The cursor is not moved in this case.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn remove_current_and_move_back(&mut self) -> Option<(K, V)> {
+        let current = self.current.take()?;
+        let mut emptied_internal_root = false;
+        let (kv, pos) =
+            current.remove_kv_tracking(|| emptied_internal_root = true, self.alloc.clone());
+        self.current = pos.next_back_kv().ok();
+        *self.length -= 1;
+        if emptied_internal_root {
+            // SAFETY: This is safe since current does not point within the now
+            // empty root node.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.pop_internal_level(self.alloc.clone());
+        }
+        Some(kv)
+    }
 }
 
 #[cfg(test)]
diff --git a/library/alloc/src/collections/btree/map/entry.rs b/library/alloc/src/collections/btree/map/entry.rs
index 370b58864af..e9366eec9ce 100644
--- a/library/alloc/src/collections/btree/map/entry.rs
+++ b/library/alloc/src/collections/btree/map/entry.rs
@@ -347,7 +347,7 @@ impl<'a, K: Ord, V, A: Allocator + Clone> VacantEntry<'a, K, V, A> {
     /// assert_eq!(map["poneyland"], 37);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn insert(self, value: V) -> &'a mut V {
+    pub fn insert(mut self, value: V) -> &'a mut V {
         let out_ptr = match self.handle {
             None => {
                 // SAFETY: There is no tree yet so no reference to it exists.
@@ -358,25 +358,27 @@ impl<'a, K: Ord, V, A: Allocator + Clone> VacantEntry<'a, K, V, A> {
                 map.length = 1;
                 val_ptr
             }
-            Some(handle) => match handle.insert_recursing(self.key, value, self.alloc.clone()) {
-                (None, val_ptr) => {
-                    // SAFETY: We have consumed self.handle.
-                    let map = unsafe { self.dormant_map.awaken() };
-                    map.length += 1;
-                    val_ptr
-                }
-                (Some(ins), val_ptr) => {
-                    drop(ins.left);
-                    // SAFETY: We have consumed self.handle and dropped the
-                    // remaining reference to the tree, ins.left.
-                    let map = unsafe { self.dormant_map.awaken() };
-                    let root = map.root.as_mut().unwrap(); // same as ins.left
-                    root.push_internal_level(self.alloc).push(ins.kv.0, ins.kv.1, ins.right);
-                    map.length += 1;
-                    val_ptr
-                }
-            },
+            Some(handle) => {
+                let new_handle =
+                    handle.insert_recursing(self.key, value, self.alloc.clone(), |ins| {
+                        drop(ins.left);
+                        // SAFETY: Pushing a new root node doesn't invalidate
+                        // handles to existing nodes.
+                        let map = unsafe { self.dormant_map.reborrow() };
+                        let root = map.root.as_mut().unwrap(); // same as ins.left
+                        root.push_internal_level(self.alloc).push(ins.kv.0, ins.kv.1, ins.right)
+                    });
+
+                // Get the pointer to the value
+                let val_ptr = new_handle.into_val_mut();
+
+                // SAFETY: We have consumed self.handle.
+                let map = unsafe { self.dormant_map.awaken() };
+                map.length += 1;
+                val_ptr
+            }
         };
+
         // Now that we have finished growing the tree using borrowed references,
         // dereference the pointer to a part of it, that we picked up along the way.
         unsafe { &mut *out_ptr }
diff --git a/library/alloc/src/collections/btree/map/tests.rs b/library/alloc/src/collections/btree/map/tests.rs
index 700b1463bfd..76c2f27b466 100644
--- a/library/alloc/src/collections/btree/map/tests.rs
+++ b/library/alloc/src/collections/btree/map/tests.rs
@@ -2336,3 +2336,52 @@ fn from_array() {
     let unordered_duplicates = BTreeMap::from([(3, 4), (1, 2), (1, 2)]);
     assert_eq!(map, unordered_duplicates);
 }
+
+#[test]
+fn test_cursor() {
+    let map = BTreeMap::from([(1, 'a'), (2, 'b'), (3, 'c')]);
+
+    let mut cur = map.lower_bound(Bound::Unbounded);
+    assert_eq!(cur.key(), Some(&1));
+    cur.move_next();
+    assert_eq!(cur.key(), Some(&2));
+    assert_eq!(cur.peek_next(), Some((&3, &'c')));
+    cur.move_prev();
+    assert_eq!(cur.key(), Some(&1));
+    assert_eq!(cur.peek_prev(), None);
+
+    let mut cur = map.upper_bound(Bound::Excluded(&1));
+    assert_eq!(cur.key(), None);
+    cur.move_next();
+    assert_eq!(cur.key(), Some(&1));
+    cur.move_prev();
+    assert_eq!(cur.key(), None);
+    assert_eq!(cur.peek_prev(), Some((&3, &'c')));
+}
+
+#[test]
+fn test_cursor_mut() {
+    let mut map = BTreeMap::from([(1, 'a'), (3, 'c'), (5, 'e')]);
+    let mut cur = map.lower_bound_mut(Bound::Excluded(&3));
+    assert_eq!(cur.key(), Some(&5));
+    cur.insert_before(4, 'd');
+    assert_eq!(cur.key(), Some(&5));
+    assert_eq!(cur.peek_prev(), Some((&4, &mut 'd')));
+    cur.move_next();
+    assert_eq!(cur.key(), None);
+    cur.insert_before(6, 'f');
+    assert_eq!(cur.key(), None);
+    assert_eq!(cur.remove_current(), None);
+    assert_eq!(cur.key(), None);
+    cur.insert_after(0, '?');
+    assert_eq!(cur.key(), None);
+    assert_eq!(map, BTreeMap::from([(0, '?'), (1, 'a'), (3, 'c'), (4, 'd'), (5, 'e'), (6, 'f')]));
+
+    let mut cur = map.upper_bound_mut(Bound::Included(&5));
+    assert_eq!(cur.key(), Some(&5));
+    assert_eq!(cur.remove_current(), Some((5, 'e')));
+    assert_eq!(cur.key(), Some(&6));
+    assert_eq!(cur.remove_current_and_move_back(), Some((6, 'f')));
+    assert_eq!(cur.key(), Some(&4));
+    assert_eq!(map, BTreeMap::from([(0, '?'), (1, 'a'), (3, 'c'), (4, 'd')]));
+}
diff --git a/library/alloc/src/collections/btree/navigate.rs b/library/alloc/src/collections/btree/navigate.rs
index 1e33c1e64d6..b890717e50b 100644
--- a/library/alloc/src/collections/btree/navigate.rs
+++ b/library/alloc/src/collections/btree/navigate.rs
@@ -4,6 +4,7 @@ use core::ops::RangeBounds;
 use core::ptr;
 
 use super::node::{marker, ForceResult::*, Handle, NodeRef};
+use super::search::SearchBound;
 
 use crate::alloc::Allocator;
 // `front` and `back` are always both `None` or both `Some`.
@@ -386,7 +387,7 @@ impl<BorrowType: marker::BorrowType, K, V>
     /// Given a leaf edge handle, returns [`Result::Ok`] with a handle to the neighboring KV
     /// on the left side, which is either in the same leaf node or in an ancestor node.
     /// If the leaf edge is the first one in the tree, returns [`Result::Err`] with the root node.
-    fn next_back_kv(
+    pub fn next_back_kv(
         self,
     ) -> Result<
         Handle<NodeRef<BorrowType, K, V, marker::LeafOrInternal>, marker::KV>,
@@ -707,7 +708,9 @@ impl<BorrowType: marker::BorrowType, K, V>
     }
 
     /// Returns the leaf edge closest to a KV for backward navigation.
-    fn next_back_leaf_edge(self) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> {
+    pub fn next_back_leaf_edge(
+        self,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> {
         match self.force() {
             Leaf(leaf_kv) => leaf_kv.left_edge(),
             Internal(internal_kv) => {
@@ -717,3 +720,51 @@ impl<BorrowType: marker::BorrowType, K, V>
         }
     }
 }
+
+impl<BorrowType: marker::BorrowType, K, V> NodeRef<BorrowType, K, V, marker::LeafOrInternal> {
+    /// Returns the leaf edge corresponding to the first point at which the
+    /// given bound is true.
+    pub fn lower_bound<Q: ?Sized>(
+        self,
+        mut bound: SearchBound<&Q>,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>
+    where
+        Q: Ord,
+        K: Borrow<Q>,
+    {
+        let mut node = self;
+        loop {
+            let (edge, new_bound) = node.find_lower_bound_edge(bound);
+            match edge.force() {
+                Leaf(edge) => return edge,
+                Internal(edge) => {
+                    node = edge.descend();
+                    bound = new_bound;
+                }
+            }
+        }
+    }
+
+    /// Returns the leaf edge corresponding to the last point at which the
+    /// given bound is true.
+    pub fn upper_bound<Q: ?Sized>(
+        self,
+        mut bound: SearchBound<&Q>,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>
+    where
+        Q: Ord,
+        K: Borrow<Q>,
+    {
+        let mut node = self;
+        loop {
+            let (edge, new_bound) = node.find_upper_bound_edge(bound);
+            match edge.force() {
+                Leaf(edge) => return edge,
+                Internal(edge) => {
+                    node = edge.descend();
+                    bound = new_bound;
+                }
+            }
+        }
+    }
+}
diff --git a/library/alloc/src/collections/btree/node.rs b/library/alloc/src/collections/btree/node.rs
index 6912466448f..3233a575ecf 100644
--- a/library/alloc/src/collections/btree/node.rs
+++ b/library/alloc/src/collections/btree/node.rs
@@ -442,6 +442,24 @@ impl<'a, K, V, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
         // SAFETY: we have exclusive access to the entire node.
         unsafe { &mut *ptr }
     }
+
+    /// Returns a dormant copy of this node with its lifetime erased which can
+    /// be reawakened later.
+    pub fn dormant(&self) -> NodeRef<marker::DormantMut, K, V, Type> {
+        NodeRef { height: self.height, node: self.node, _marker: PhantomData }
+    }
+}
+
+impl<K, V, Type> NodeRef<marker::DormantMut, K, V, Type> {
+    /// Revert to the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn awaken<'a>(self) -> NodeRef<marker::Mut<'a>, K, V, Type> {
+        NodeRef { height: self.height, node: self.node, _marker: PhantomData }
+    }
 }
 
 impl<K, V, Type> NodeRef<marker::Dying, K, V, Type> {
@@ -798,6 +816,25 @@ impl<'a, K, V, NodeType, HandleType> Handle<NodeRef<marker::Mut<'a>, K, V, NodeT
         // We can't use Handle::new_kv or Handle::new_edge because we don't know our type
         Handle { node: unsafe { self.node.reborrow_mut() }, idx: self.idx, _marker: PhantomData }
     }
+
+    /// Returns a dormant copy of this handle which can be reawakened later.
+    ///
+    /// See `DormantMutRef` for more details.
+    pub fn dormant(&self) -> Handle<NodeRef<marker::DormantMut, K, V, NodeType>, HandleType> {
+        Handle { node: self.node.dormant(), idx: self.idx, _marker: PhantomData }
+    }
+}
+
+impl<K, V, NodeType, HandleType> Handle<NodeRef<marker::DormantMut, K, V, NodeType>, HandleType> {
+    /// Revert to the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn awaken<'a>(self) -> Handle<NodeRef<marker::Mut<'a>, K, V, NodeType>, HandleType> {
+        Handle { node: unsafe { self.node.awaken() }, idx: self.idx, _marker: PhantomData }
+    }
 }
 
 impl<BorrowType, K, V, NodeType> Handle<NodeRef<BorrowType, K, V, NodeType>, marker::Edge> {
@@ -851,9 +888,11 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
     /// Inserts a new key-value pair between the key-value pairs to the right and left of
     /// this edge. This method assumes that there is enough space in the node for the new
     /// pair to fit.
-    ///
-    /// The returned pointer points to the inserted value.
-    fn insert_fit(&mut self, key: K, val: V) -> *mut V {
+    unsafe fn insert_fit(
+        mut self,
+        key: K,
+        val: V,
+    ) -> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::KV> {
         debug_assert!(self.node.len() < CAPACITY);
         let new_len = self.node.len() + 1;
 
@@ -862,7 +901,7 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
             slice_insert(self.node.val_area_mut(..new_len), self.idx, val);
             *self.node.len_mut() = new_len as u16;
 
-            self.node.val_area_mut(self.idx).assume_init_mut()
+            Handle::new_kv(self.node, self.idx)
         }
     }
 }
@@ -871,21 +910,26 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
     /// Inserts a new key-value pair between the key-value pairs to the right and left of
     /// this edge. This method splits the node if there isn't enough room.
     ///
-    /// The returned pointer points to the inserted value.
+    /// Returns a dormant handle to the inserted node which can be reawakened
+    /// once splitting is complete.
     fn insert<A: Allocator + Clone>(
-        mut self,
+        self,
         key: K,
         val: V,
         alloc: A,
-    ) -> (Option<SplitResult<'a, K, V, marker::Leaf>>, *mut V) {
+    ) -> (
+        Option<SplitResult<'a, K, V, marker::Leaf>>,
+        Handle<NodeRef<marker::DormantMut, K, V, marker::Leaf>, marker::KV>,
+    ) {
         if self.node.len() < CAPACITY {
-            let val_ptr = self.insert_fit(key, val);
-            (None, val_ptr)
+            // SAFETY: There is enough space in the node for insertion.
+            let handle = unsafe { self.insert_fit(key, val) };
+            (None, handle.dormant())
         } else {
             let (middle_kv_idx, insertion) = splitpoint(self.idx);
             let middle = unsafe { Handle::new_kv(self.node, middle_kv_idx) };
             let mut result = middle.split(alloc);
-            let mut insertion_edge = match insertion {
+            let insertion_edge = match insertion {
                 LeftOrRight::Left(insert_idx) => unsafe {
                     Handle::new_edge(result.left.reborrow_mut(), insert_idx)
                 },
@@ -893,8 +937,10 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
                     Handle::new_edge(result.right.borrow_mut(), insert_idx)
                 },
             };
-            let val_ptr = insertion_edge.insert_fit(key, val);
-            (Some(result), val_ptr)
+            // SAFETY: We just split the node, so there is enough space for
+            // insertion.
+            let handle = unsafe { insertion_edge.insert_fit(key, val).dormant() };
+            (Some(result), handle)
         }
     }
 }
@@ -976,21 +1022,31 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
         key: K,
         value: V,
         alloc: A,
-    ) -> (Option<SplitResult<'a, K, V, marker::LeafOrInternal>>, *mut V) {
-        let (mut split, val_ptr) = match self.insert(key, value, alloc.clone()) {
-            (None, val_ptr) => return (None, val_ptr),
-            (Some(split), val_ptr) => (split.forget_node_type(), val_ptr),
+        split_root: impl FnOnce(SplitResult<'a, K, V, marker::LeafOrInternal>),
+    ) -> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::KV> {
+        let (mut split, handle) = match self.insert(key, value, alloc.clone()) {
+            // SAFETY: we have finished splitting and can now re-awaken the
+            // handle to the inserted element.
+            (None, handle) => return unsafe { handle.awaken() },
+            (Some(split), handle) => (split.forget_node_type(), handle),
         };
 
         loop {
             split = match split.left.ascend() {
                 Ok(parent) => {
                     match parent.insert(split.kv.0, split.kv.1, split.right, alloc.clone()) {
-                        None => return (None, val_ptr),
+                        // SAFETY: we have finished splitting and can now re-awaken the
+                        // handle to the inserted element.
+                        None => return unsafe { handle.awaken() },
                         Some(split) => split.forget_node_type(),
                     }
                 }
-                Err(root) => return (Some(SplitResult { left: root, ..split }), val_ptr),
+                Err(root) => {
+                    split_root(SplitResult { left: root, ..split });
+                    // SAFETY: we have finished splitting and can now re-awaken the
+                    // handle to the inserted element.
+                    return unsafe { handle.awaken() };
+                }
             };
         }
     }
@@ -1043,6 +1099,14 @@ impl<'a, K: 'a, V: 'a, NodeType> Handle<NodeRef<marker::Mut<'a>, K, V, NodeType>
         let leaf = self.node.into_leaf_mut();
         unsafe { leaf.vals.get_unchecked_mut(self.idx).assume_init_mut() }
     }
+
+    pub fn into_kv_valmut(self) -> (&'a K, &'a mut V) {
+        debug_assert!(self.idx < self.node.len());
+        let leaf = self.node.into_leaf_mut();
+        let k = unsafe { leaf.keys.get_unchecked(self.idx).assume_init_ref() };
+        let v = unsafe { leaf.vals.get_unchecked_mut(self.idx).assume_init_mut() };
+        (k, v)
+    }
 }
 
 impl<'a, K, V, NodeType> Handle<NodeRef<marker::ValMut<'a>, K, V, NodeType>, marker::KV> {
@@ -1667,6 +1731,7 @@ pub mod marker {
 
     pub enum Owned {}
     pub enum Dying {}
+    pub enum DormantMut {}
     pub struct Immut<'a>(PhantomData<&'a ()>);
     pub struct Mut<'a>(PhantomData<&'a mut ()>);
     pub struct ValMut<'a>(PhantomData<&'a mut ()>);
@@ -1688,6 +1753,7 @@ pub mod marker {
     impl<'a> BorrowType for Immut<'a> {}
     impl<'a> BorrowType for Mut<'a> {}
     impl<'a> BorrowType for ValMut<'a> {}
+    impl BorrowType for DormantMut {}
 
     pub enum KV {}
     pub enum Edge {}
diff --git a/library/alloc/src/fmt.rs b/library/alloc/src/fmt.rs
index eadb35cb96d..1da86e1a46a 100644
--- a/library/alloc/src/fmt.rs
+++ b/library/alloc/src/fmt.rs
@@ -558,7 +558,7 @@ pub use core::fmt::Alignment;
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::fmt::Error;
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use core::fmt::{write, ArgumentV1, Arguments};
+pub use core::fmt::{write, Arguments};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::fmt::{Binary, Octal};
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index ca75c3895f4..76dabfb429d 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -87,6 +87,7 @@
 #![warn(missing_debug_implementations)]
 #![warn(missing_docs)]
 #![allow(explicit_outlives_requirements)]
+#![cfg_attr(not(bootstrap), warn(multiple_supertrait_upcastable))]
 //
 // Library features:
 #![feature(alloc_layout_extra)]
@@ -195,6 +196,7 @@
 #![feature(c_unwind)]
 #![feature(with_negative_coherence)]
 #![cfg_attr(test, feature(panic_update_hook))]
+#![cfg_attr(not(bootstrap), feature(multiple_supertrait_upcastable))]
 //
 // Rustdoc features:
 #![feature(doc_cfg)]
diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index c9aa23fc4af..fd1e3e0f75b 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -1092,7 +1092,7 @@ impl<T: ?Sized> Rc<T> {
     /// # Safety
     ///
     /// If any other `Rc` or [`Weak`] pointers to the same allocation exist, then
-    /// they must be must not be dereferenced or have active borrows for the duration
+    /// they must not be dereferenced or have active borrows for the duration
     /// of the returned borrow, and their inner type must be exactly the same as the
     /// inner type of this Rc (including lifetimes). This is trivially the case if no
     /// such pointers exist, for example immediately after `Rc::new`.
diff --git a/library/alloc/src/slice.rs b/library/alloc/src/slice.rs
index fecacc2bb63..093dcbbe8bf 100644
--- a/library/alloc/src/slice.rs
+++ b/library/alloc/src/slice.rs
@@ -782,6 +782,38 @@ impl<T, A: Allocator> BorrowMut<[T]> for Vec<T, A> {
     }
 }
 
+// Specializable trait for implementing ToOwned::clone_into. This is
+// public in the crate and has the Allocator parameter so that
+// vec::clone_from use it too.
+#[cfg(not(no_global_oom_handling))]
+pub(crate) trait SpecCloneIntoVec<T, A: Allocator> {
+    fn clone_into(&self, target: &mut Vec<T, A>);
+}
+
+#[cfg(not(no_global_oom_handling))]
+impl<T: Clone, A: Allocator> SpecCloneIntoVec<T, A> for [T] {
+    default fn clone_into(&self, target: &mut Vec<T, A>) {
+        // drop anything in target that will not be overwritten
+        target.truncate(self.len());
+
+        // target.len <= self.len due to the truncate above, so the
+        // slices here are always in-bounds.
+        let (init, tail) = self.split_at(target.len());
+
+        // reuse the contained values' allocations/resources.
+        target.clone_from_slice(init);
+        target.extend_from_slice(tail);
+    }
+}
+
+#[cfg(not(no_global_oom_handling))]
+impl<T: Copy, A: Allocator> SpecCloneIntoVec<T, A> for [T] {
+    fn clone_into(&self, target: &mut Vec<T, A>) {
+        target.clear();
+        target.extend_from_slice(self);
+    }
+}
+
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Clone> ToOwned for [T] {
@@ -797,16 +829,7 @@ impl<T: Clone> ToOwned for [T] {
     }
 
     fn clone_into(&self, target: &mut Vec<T>) {
-        // drop anything in target that will not be overwritten
-        target.truncate(self.len());
-
-        // target.len <= self.len due to the truncate above, so the
-        // slices here are always in-bounds.
-        let (init, tail) = self.split_at(target.len());
-
-        // reuse the contained values' allocations/resources.
-        target.clone_from_slice(init);
-        target.extend_from_slice(tail);
+        SpecCloneIntoVec::clone_into(self, target);
     }
 }
 
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index 9bc9182f7b5..f20486ca9e4 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -1733,7 +1733,7 @@ impl<T: ?Sized> Arc<T> {
     /// # Safety
     ///
     /// If any other `Arc` or [`Weak`] pointers to the same allocation exist, then
-    /// they must be must not be dereferenced or have active borrows for the duration
+    /// they must not be dereferenced or have active borrows for the duration
     /// of the returned borrow, and their inner type must be exactly the same as the
     /// inner type of this Rc (including lifetimes). This is trivially the case if no
     /// such pointers exist, for example immediately after `Arc::new`.
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 36b0b3c9e7c..a07f3da78d3 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -2647,35 +2647,6 @@ impl<T, A: Allocator> ops::DerefMut for Vec<T, A> {
 }
 
 #[cfg(not(no_global_oom_handling))]
-trait SpecCloneFrom {
-    fn clone_from(this: &mut Self, other: &Self);
-}
-
-#[cfg(not(no_global_oom_handling))]
-impl<T: Clone, A: Allocator> SpecCloneFrom for Vec<T, A> {
-    default fn clone_from(this: &mut Self, other: &Self) {
-        // drop anything that will not be overwritten
-        this.truncate(other.len());
-
-        // self.len <= other.len due to the truncate above, so the
-        // slices here are always in-bounds.
-        let (init, tail) = other.split_at(this.len());
-
-        // reuse the contained values' allocations/resources.
-        this.clone_from_slice(init);
-        this.extend_from_slice(tail);
-    }
-}
-
-#[cfg(not(no_global_oom_handling))]
-impl<T: Copy, A: Allocator> SpecCloneFrom for Vec<T, A> {
-    fn clone_from(this: &mut Self, other: &Self) {
-        this.clear();
-        this.extend_from_slice(other);
-    }
-}
-
-#[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Clone, A: Allocator + Clone> Clone for Vec<T, A> {
     #[cfg(not(test))]
@@ -2695,7 +2666,7 @@ impl<T: Clone, A: Allocator + Clone> Clone for Vec<T, A> {
     }
 
     fn clone_from(&mut self, other: &Self) {
-        SpecCloneFrom::clone_from(self, other)
+        crate::slice::SpecCloneIntoVec::clone_into(other.as_slice(), self);
     }
 }
 
diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
index 129213fde74..7f109491350 100644
--- a/library/core/src/cell.rs
+++ b/library/core/src/cell.rs
@@ -196,7 +196,7 @@ use crate::cmp::Ordering;
 use crate::fmt::{self, Debug, Display};
 use crate::marker::{PhantomData, Unsize};
 use crate::mem;
-use crate::ops::{CoerceUnsized, Deref, DerefMut};
+use crate::ops::{CoerceUnsized, Deref, DerefMut, DispatchFromDyn};
 use crate::ptr::{self, NonNull};
 
 mod lazy;
@@ -571,6 +571,16 @@ impl<T: Default> Cell<T> {
 #[unstable(feature = "coerce_unsized", issue = "18598")]
 impl<T: CoerceUnsized<U>, U> CoerceUnsized<Cell<U>> for Cell<T> {}
 
+// Allow types that wrap `Cell` to also implement `DispatchFromDyn`
+// and become object safe method receivers.
+// Note that currently `Cell` itself cannot be a method receiver
+// because it does not implement Deref.
+// In other words:
+// `self: Cell<&Self>` won't work
+// `self: CellWrapper<Self>` becomes possible
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
+impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<Cell<U>> for Cell<T> {}
+
 impl<T> Cell<[T]> {
     /// Returns a `&[Cell<T>]` from a `&Cell<[T]>`
     ///
@@ -2078,6 +2088,16 @@ impl<T> const From<T> for UnsafeCell<T> {
 #[unstable(feature = "coerce_unsized", issue = "18598")]
 impl<T: CoerceUnsized<U>, U> CoerceUnsized<UnsafeCell<U>> for UnsafeCell<T> {}
 
+// Allow types that wrap `UnsafeCell` to also implement `DispatchFromDyn`
+// and become object safe method receivers.
+// Note that currently `UnsafeCell` itself cannot be a method receiver
+// because it does not implement Deref.
+// In other words:
+// `self: UnsafeCell<&Self>` won't work
+// `self: UnsafeCellWrapper<Self>` becomes possible
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
+impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<UnsafeCell<U>> for UnsafeCell<T> {}
+
 /// [`UnsafeCell`], but [`Sync`].
 ///
 /// This is just an `UnsafeCell`, except it implements `Sync`
@@ -2169,6 +2189,17 @@ impl<T> const From<T> for SyncUnsafeCell<T> {
 //#[unstable(feature = "sync_unsafe_cell", issue = "95439")]
 impl<T: CoerceUnsized<U>, U> CoerceUnsized<SyncUnsafeCell<U>> for SyncUnsafeCell<T> {}
 
+// Allow types that wrap `SyncUnsafeCell` to also implement `DispatchFromDyn`
+// and become object safe method receivers.
+// Note that currently `SyncUnsafeCell` itself cannot be a method receiver
+// because it does not implement Deref.
+// In other words:
+// `self: SyncUnsafeCell<&Self>` won't work
+// `self: SyncUnsafeCellWrapper<Self>` becomes possible
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
+//#[unstable(feature = "sync_unsafe_cell", issue = "95439")]
+impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<SyncUnsafeCell<U>> for SyncUnsafeCell<T> {}
+
 #[allow(unused)]
 fn assert_coerce_unsized(
     a: UnsafeCell<&i32>,
diff --git a/library/core/src/cell/once.rs b/library/core/src/cell/once.rs
index 7757068a4f2..f74e563f1b9 100644
--- a/library/core/src/cell/once.rs
+++ b/library/core/src/cell/once.rs
@@ -298,3 +298,7 @@ impl<T> const From<T> for OnceCell<T> {
         OnceCell { inner: UnsafeCell::new(Some(value)) }
     }
 }
+
+// Just like for `Cell<T>` this isn't needed, but results in nicer error messages.
+#[unstable(feature = "once_cell", issue = "74465")]
+impl<T> !Sync for OnceCell<T> {}
diff --git a/library/core/src/error.rs b/library/core/src/error.rs
index 7152300abcb..d2fac23ff18 100644
--- a/library/core/src/error.rs
+++ b/library/core/src/error.rs
@@ -28,6 +28,7 @@ use crate::fmt::{Debug, Display};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[cfg_attr(not(test), rustc_diagnostic_item = "Error")]
 #[rustc_has_incoherent_inherent_impls]
+#[cfg_attr(not(bootstrap), allow(multiple_supertrait_upcastable))]
 pub trait Error: Debug + Display {
     /// The lower-level source of this error, if any.
     ///
diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs
index 2a7ec544f9e..c9821bf8109 100644
--- a/library/core/src/fmt/mod.rs
+++ b/library/core/src/fmt/mod.rs
@@ -267,6 +267,7 @@ extern "C" {
 /// family of functions. It contains a function to format the given value. At
 /// compile time it is ensured that the function and the value have the correct
 /// types, and then this struct is used to canonicalize arguments to one type.
+#[cfg_attr(not(bootstrap), lang = "format_argument")]
 #[derive(Copy, Clone)]
 #[allow(missing_debug_implementations)]
 #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
@@ -279,6 +280,7 @@ pub struct ArgumentV1<'a> {
 /// This struct represents the unsafety of constructing an `Arguments`.
 /// It exists, rather than an unsafe function, in order to simplify the expansion
 /// of `format_args!(..)` and reduce the scope of the `unsafe` block.
+#[cfg_attr(not(bootstrap), lang = "format_unsafe_arg")]
 #[allow(missing_debug_implementations)]
 #[doc(hidden)]
 #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
@@ -473,8 +475,8 @@ impl<'a> Arguments<'a> {
 /// ```
 ///
 /// [`format()`]: ../../std/fmt/fn.format.html
+#[cfg_attr(not(bootstrap), lang = "format_arguments")]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(not(test), rustc_diagnostic_item = "Arguments")]
 #[derive(Copy, Clone)]
 pub struct Arguments<'a> {
     // Format string pieces to print.
@@ -489,9 +491,26 @@ pub struct Arguments<'a> {
 }
 
 impl<'a> Arguments<'a> {
-    /// Get the formatted string, if it has no arguments to be formatted.
+    /// Get the formatted string, if it has no arguments to be formatted at runtime.
     ///
-    /// This can be used to avoid allocations in the most trivial case.
+    /// This can be used to avoid allocations in some cases.
+    ///
+    /// # Guarantees
+    ///
+    /// For `format_args!("just a literal")`, this function is guaranteed to
+    /// return `Some("just a literal")`.
+    ///
+    /// For most cases with placeholders, this function will return `None`.
+    ///
+    /// However, the compiler may perform optimizations that can cause this
+    /// function to return `Some(_)` even if the format string contains
+    /// placeholders. For example, `format_args!("Hello, {}!", "world")` may be
+    /// optimized to `format_args!("Hello, world!")`, such that `as_str()`
+    /// returns `Some("Hello, world!")`.
+    ///
+    /// The behavior for anything but the trivial case (without placeholders)
+    /// is not guaranteed, and should not be relied upon for anything other
+    /// than optimization.
     ///
     /// # Examples
     ///
@@ -512,7 +531,7 @@ impl<'a> Arguments<'a> {
     /// ```rust
     /// assert_eq!(format_args!("hello").as_str(), Some("hello"));
     /// assert_eq!(format_args!("").as_str(), Some(""));
-    /// assert_eq!(format_args!("{}", 1).as_str(), None);
+    /// assert_eq!(format_args!("{:?}", std::env::current_dir()).as_str(), None);
     /// ```
     #[stable(feature = "fmt_as_str", since = "1.52.0")]
     #[rustc_const_unstable(feature = "const_arguments_as_str", issue = "103900")]
diff --git a/library/core/src/fmt/rt/v1.rs b/library/core/src/fmt/rt/v1.rs
index 37202b2774d..11a50951a75 100644
--- a/library/core/src/fmt/rt/v1.rs
+++ b/library/core/src/fmt/rt/v1.rs
@@ -5,7 +5,9 @@
 //! these can be statically allocated and are slightly optimized for the runtime
 #![allow(missing_debug_implementations)]
 
+#[cfg_attr(not(bootstrap), lang = "format_placeholder")]
 #[derive(Copy, Clone)]
+// FIXME: Rename this to Placeholder
 pub struct Argument {
     pub position: usize,
     pub format: FormatSpec,
@@ -20,7 +22,22 @@ pub struct FormatSpec {
     pub width: Count,
 }
 
+impl Argument {
+    #[inline(always)]
+    pub const fn new(
+        position: usize,
+        fill: char,
+        align: Alignment,
+        flags: u32,
+        precision: Count,
+        width: Count,
+    ) -> Self {
+        Self { position, format: FormatSpec { fill, align, flags, precision, width } }
+    }
+}
+
 /// Possible alignments that can be requested as part of a formatting directive.
+#[cfg_attr(not(bootstrap), lang = "format_alignment")]
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub enum Alignment {
     /// Indication that contents should be left-aligned.
@@ -34,6 +51,7 @@ pub enum Alignment {
 }
 
 /// Used by [width](https://doc.rust-lang.org/std/fmt/#width) and [precision](https://doc.rust-lang.org/std/fmt/#precision) specifiers.
+#[cfg_attr(not(bootstrap), lang = "format_count")]
 #[derive(Copy, Clone)]
 pub enum Count {
     /// Specified with a literal number, stores the value
diff --git a/library/core/src/intrinsics/mir.rs b/library/core/src/intrinsics/mir.rs
index e3157b66902..3d7ccffa173 100644
--- a/library/core/src/intrinsics/mir.rs
+++ b/library/core/src/intrinsics/mir.rs
@@ -211,13 +211,16 @@
 //!
 //! #### Statements
 //!  - Assign statements work via normal Rust assignment.
-//!  - [`Retag`] statements have an associated function.
+//!  - [`Retag`], [`StorageLive`], [`StorageDead`], [`Deinit`] statements have an associated function.
 //!
 //! #### Rvalues
 //!
 //!  - Operands implicitly convert to `Use` rvalues.
 //!  - `&`, `&mut`, `addr_of!`, and `addr_of_mut!` all work to create their associated rvalue.
-//!  - [`Discriminant`] has an associated function.
+//!  - [`Discriminant`] and [`Len`] have associated functions.
+//!  - Unary and binary operations use their normal Rust syntax - `a * b`, `!c`, etc.
+//!  - Checked binary operations are represented by wrapping the associated binop in [`Checked`].
+//!  - Array repetition syntax (`[foo; 10]`) creates the associated rvalue.
 //!
 //! #### Terminators
 //!
@@ -261,6 +264,9 @@ define!("mir_drop_and_replace", fn DropAndReplace<T>(place: T, value: T, goto: B
 define!("mir_call", fn Call<T>(place: T, goto: BasicBlock, call: T));
 define!("mir_storage_live", fn StorageLive<T>(local: T));
 define!("mir_storage_dead", fn StorageDead<T>(local: T));
+define!("mir_deinit", fn Deinit<T>(place: T));
+define!("mir_checked", fn Checked<T>(binop: T) -> (T, bool));
+define!("mir_len", fn Len<T>(place: T) -> usize);
 define!("mir_retag", fn Retag<T>(place: T));
 define!("mir_move", fn Move<T>(place: T) -> T);
 define!("mir_static", fn Static<T>(s: T) -> &'static T);
diff --git a/library/core/src/iter/adapters/filter_map.rs b/library/core/src/iter/adapters/filter_map.rs
index e0d665c9e12..6bdf53f7fc9 100644
--- a/library/core/src/iter/adapters/filter_map.rs
+++ b/library/core/src/iter/adapters/filter_map.rs
@@ -99,7 +99,7 @@ where
         ) -> impl FnMut((), T) -> ControlFlow<B> + '_ {
             move |(), x| match f(x) {
                 Some(x) => ControlFlow::Break(x),
-                None => ControlFlow::CONTINUE,
+                None => ControlFlow::Continue(()),
             }
         }
 
diff --git a/library/core/src/iter/adapters/flatten.rs b/library/core/src/iter/adapters/flatten.rs
index 307016c2690..b040a0ea901 100644
--- a/library/core/src/iter/adapters/flatten.rs
+++ b/library/core/src/iter/adapters/flatten.rs
@@ -539,7 +539,7 @@ where
         #[rustc_inherit_overflow_checks]
         fn advance<U: Iterator>(n: usize, iter: &mut U) -> ControlFlow<(), usize> {
             match iter.advance_by(n) {
-                Ok(()) => ControlFlow::BREAK,
+                Ok(()) => ControlFlow::Break(()),
                 Err(advanced) => ControlFlow::Continue(n - advanced),
             }
         }
@@ -629,7 +629,7 @@ where
         #[rustc_inherit_overflow_checks]
         fn advance<U: DoubleEndedIterator>(n: usize, iter: &mut U) -> ControlFlow<(), usize> {
             match iter.advance_back_by(n) {
-                Ok(()) => ControlFlow::BREAK,
+                Ok(()) => ControlFlow::Break(()),
                 Err(advanced) => ControlFlow::Continue(n - advanced),
             }
         }
diff --git a/library/core/src/iter/traits/double_ended.rs b/library/core/src/iter/traits/double_ended.rs
index bdf94c792c2..ed23873cdde 100644
--- a/library/core/src/iter/traits/double_ended.rs
+++ b/library/core/src/iter/traits/double_ended.rs
@@ -352,7 +352,7 @@ pub trait DoubleEndedIterator: Iterator {
         #[inline]
         fn check<T>(mut predicate: impl FnMut(&T) -> bool) -> impl FnMut((), T) -> ControlFlow<T> {
             move |(), x| {
-                if predicate(&x) { ControlFlow::Break(x) } else { ControlFlow::CONTINUE }
+                if predicate(&x) { ControlFlow::Break(x) } else { ControlFlow::Continue(()) }
             }
         }
 
diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs
index a4a665d48d5..5a0b8594104 100644
--- a/library/core/src/iter/traits/iterator.rs
+++ b/library/core/src/iter/traits/iterator.rs
@@ -2601,10 +2601,10 @@ pub trait Iterator {
         #[inline]
         fn check<T>(mut f: impl FnMut(T) -> bool) -> impl FnMut((), T) -> ControlFlow<()> {
             move |(), x| {
-                if f(x) { ControlFlow::CONTINUE } else { ControlFlow::BREAK }
+                if f(x) { ControlFlow::Continue(()) } else { ControlFlow::Break(()) }
             }
         }
-        self.try_fold((), check(f)) == ControlFlow::CONTINUE
+        self.try_fold((), check(f)) == ControlFlow::Continue(())
     }
 
     /// Tests if any element of the iterator matches a predicate.
@@ -2654,11 +2654,11 @@ pub trait Iterator {
         #[inline]
         fn check<T>(mut f: impl FnMut(T) -> bool) -> impl FnMut((), T) -> ControlFlow<()> {
             move |(), x| {
-                if f(x) { ControlFlow::BREAK } else { ControlFlow::CONTINUE }
+                if f(x) { ControlFlow::Break(()) } else { ControlFlow::Continue(()) }
             }
         }
 
-        self.try_fold((), check(f)) == ControlFlow::BREAK
+        self.try_fold((), check(f)) == ControlFlow::Break(())
     }
 
     /// Searches for an element of an iterator that satisfies a predicate.
@@ -2717,7 +2717,7 @@ pub trait Iterator {
         #[inline]
         fn check<T>(mut predicate: impl FnMut(&T) -> bool) -> impl FnMut((), T) -> ControlFlow<T> {
             move |(), x| {
-                if predicate(&x) { ControlFlow::Break(x) } else { ControlFlow::CONTINUE }
+                if predicate(&x) { ControlFlow::Break(x) } else { ControlFlow::Continue(()) }
             }
         }
 
@@ -2749,7 +2749,7 @@ pub trait Iterator {
         fn check<T, B>(mut f: impl FnMut(T) -> Option<B>) -> impl FnMut((), T) -> ControlFlow<B> {
             move |(), x| match f(x) {
                 Some(x) => ControlFlow::Break(x),
-                None => ControlFlow::CONTINUE,
+                None => ControlFlow::Continue(()),
             }
         }
 
@@ -2812,7 +2812,7 @@ pub trait Iterator {
             R: Residual<Option<I>>,
         {
             move |(), x| match f(&x).branch() {
-                ControlFlow::Continue(false) => ControlFlow::CONTINUE,
+                ControlFlow::Continue(false) => ControlFlow::Continue(()),
                 ControlFlow::Continue(true) => ControlFlow::Break(Try::from_output(Some(x))),
                 ControlFlow::Break(r) => ControlFlow::Break(FromResidual::from_residual(r)),
             }
@@ -3491,7 +3491,7 @@ pub trait Iterator {
             F: FnMut(X, Y) -> Ordering,
         {
             move |x, y| match cmp(x, y) {
-                Ordering::Equal => ControlFlow::CONTINUE,
+                Ordering::Equal => ControlFlow::Continue(()),
                 non_eq => ControlFlow::Break(non_eq),
             }
         }
@@ -3567,7 +3567,7 @@ pub trait Iterator {
             F: FnMut(X, Y) -> Option<Ordering>,
         {
             move |x, y| match partial_cmp(x, y) {
-                Some(Ordering::Equal) => ControlFlow::CONTINUE,
+                Some(Ordering::Equal) => ControlFlow::Continue(()),
                 non_eq => ControlFlow::Break(non_eq),
             }
         }
@@ -3625,7 +3625,7 @@ pub trait Iterator {
             F: FnMut(X, Y) -> bool,
         {
             move |x, y| {
-                if eq(x, y) { ControlFlow::CONTINUE } else { ControlFlow::BREAK }
+                if eq(x, y) { ControlFlow::Continue(()) } else { ControlFlow::Break(()) }
             }
         }
 
@@ -3859,7 +3859,7 @@ pub trait Iterator {
 
 /// Compares two iterators element-wise using the given function.
 ///
-/// If `ControlFlow::CONTINUE` is returned from the function, the comparison moves on to the next
+/// If `ControlFlow::Continue(())` is returned from the function, the comparison moves on to the next
 /// elements of both iterators. Returning `ControlFlow::Break(x)` short-circuits the iteration and
 /// returns `ControlFlow::Break(x)`. If one of the iterators runs out of elements,
 /// `ControlFlow::Continue(ord)` is returned where `ord` is the result of comparing the lengths of
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 8790649abe6..6dfe36e6926 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -95,6 +95,7 @@
 #![warn(missing_docs)]
 #![allow(explicit_outlives_requirements)]
 #![allow(incomplete_features)]
+#![cfg_attr(not(bootstrap), warn(multiple_supertrait_upcastable))]
 //
 // Library features:
 #![feature(const_align_offset)]
@@ -235,6 +236,7 @@
 #![feature(unsized_fn_params)]
 #![feature(asm_const)]
 #![feature(const_transmute_copy)]
+#![cfg_attr(not(bootstrap), feature(multiple_supertrait_upcastable))]
 //
 // Target features:
 #![feature(arm_target_feature)]
diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index 1326fc9ab09..74055602ec2 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -469,6 +469,62 @@ pub macro Copy($item:item) {
 #[cfg_attr(not(test), rustc_diagnostic_item = "Sync")]
 #[lang = "sync"]
 #[rustc_on_unimplemented(
+    on(
+        _Self = "std::cell::OnceCell<T>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::OnceLock` instead"
+    ),
+    on(
+        _Self = "std::cell::Cell<u8>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU8` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<u16>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU16` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<u32>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<u64>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU64` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<usize>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicUsize` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<i8>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI8` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<i16>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI16` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<i32>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<i64>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI64` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<isize>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicIsize` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<bool>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicBool` instead",
+    ),
+    on(
+        _Self = "std::cell::Cell<T>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock`",
+    ),
+    on(
+        _Self = "std::cell::RefCell<T>",
+        note = "if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead",
+    ),
     message = "`{Self}` cannot be shared between threads safely",
     label = "`{Self}` cannot be shared between threads safely"
 )]
diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs
index 2cae98b8e49..b59f28193e2 100644
--- a/library/core/src/num/int_macros.rs
+++ b/library/core/src/num/int_macros.rs
@@ -5,7 +5,7 @@ macro_rules! int_impl {
      $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr,
      $bound_condition:expr) => {
         /// The smallest value that can be represented by this integer type
-        #[doc = concat!("(&minus;2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ")")]
+        #[doc = concat!("(&minus;2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ").")]
         ///
         /// # Examples
         ///
@@ -18,7 +18,7 @@ macro_rules! int_impl {
         pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
 
         /// The largest value that can be represented by this integer type
-        #[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1", $bound_condition, ")")]
+        #[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1", $bound_condition, ").")]
         ///
         /// # Examples
         ///
@@ -2574,12 +2574,13 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
+        #[rustc_allow_const_fn_unstable(const_cmp)]
         pub const fn signum(self) -> Self {
-            match self {
-                n if n > 0 =>  1,
-                0          =>  0,
-                _          => -1,
-            }
+            // Picking the right way to phrase this is complicated
+            // (<https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>)
+            // so delegate it to `Ord` which is already producing -1/0/+1
+            // exactly like we need and can be the place to deal with the complexity.
+            self.cmp(&0) as _
         }
 
         /// Returns `true` if `self` is positive and `false` if the number is zero or
diff --git a/library/core/src/ops/control_flow.rs b/library/core/src/ops/control_flow.rs
index cd183540cd5..117706fb4b2 100644
--- a/library/core/src/ops/control_flow.rs
+++ b/library/core/src/ops/control_flow.rs
@@ -259,46 +259,3 @@ impl<R: ops::Try> ControlFlow<R, R::Output> {
         }
     }
 }
-
-impl<B> ControlFlow<B, ()> {
-    /// It's frequently the case that there's no value needed with `Continue`,
-    /// so this provides a way to avoid typing `(())`, if you prefer it.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(control_flow_enum)]
-    /// use std::ops::ControlFlow;
-    ///
-    /// let mut partial_sum = 0;
-    /// let last_used = (1..10).chain(20..25).try_for_each(|x| {
-    ///     partial_sum += x;
-    ///     if partial_sum > 100 { ControlFlow::Break(x) }
-    ///     else { ControlFlow::CONTINUE }
-    /// });
-    /// assert_eq!(last_used.break_value(), Some(22));
-    /// ```
-    #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
-    pub const CONTINUE: Self = ControlFlow::Continue(());
-}
-
-impl<C> ControlFlow<(), C> {
-    /// APIs like `try_for_each` don't need values with `Break`,
-    /// so this provides a way to avoid typing `(())`, if you prefer it.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(control_flow_enum)]
-    /// use std::ops::ControlFlow;
-    ///
-    /// let mut partial_sum = 0;
-    /// (1..10).chain(20..25).try_for_each(|x| {
-    ///     if partial_sum > 100 { ControlFlow::BREAK }
-    ///     else { partial_sum += x; ControlFlow::CONTINUE }
-    /// });
-    /// assert_eq!(partial_sum, 108);
-    /// ```
-    #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
-    pub const BREAK: Self = ControlFlow::Break(());
-}
diff --git a/library/core/src/option.rs b/library/core/src/option.rs
index 7cc00e3f8d1..c43b728022d 100644
--- a/library/core/src/option.rs
+++ b/library/core/src/option.rs
@@ -551,7 +551,7 @@ use crate::marker::Destruct;
 use crate::panicking::{panic, panic_str};
 use crate::pin::Pin;
 use crate::{
-    convert, hint, mem,
+    cmp, convert, hint, mem,
     ops::{self, ControlFlow, Deref, DerefMut},
 };
 
@@ -2090,6 +2090,12 @@ impl<T: PartialEq> PartialEq for Option<T> {
     }
 }
 
+/// This specialization trait is a workaround for LLVM not currently (2023-01)
+/// being able to optimize this itself, even though Alive confirms that it would
+/// be legal to do so: <https://github.com/llvm/llvm-project/issues/52622>
+///
+/// Once that's fixed, `Option` should go back to deriving `PartialEq`, as
+/// it used to do before <https://github.com/rust-lang/rust/pull/103556>.
 #[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]
 #[doc(hidden)]
 pub trait SpecOptionPartialEq: Sized {
@@ -2146,6 +2152,14 @@ impl<T> SpecOptionPartialEq for crate::ptr::NonNull<T> {
     }
 }
 
+#[stable(feature = "rust1", since = "1.0.0")]
+impl SpecOptionPartialEq for cmp::Ordering {
+    #[inline]
+    fn eq(l: &Option<Self>, r: &Option<Self>) -> bool {
+        l.map_or(2, |x| x as i8) == r.map_or(2, |x| x as i8)
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // The Option Iterators
 /////////////////////////////////////////////////////////////////////////////
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs
index 7b1cb5488bc..16eb726f6f6 100644
--- a/library/core/src/ptr/const_ptr.rs
+++ b/library/core/src/ptr/const_ptr.rs
@@ -731,7 +731,7 @@ impl<T: ?Sized> *const T {
     /// This computes the same value that [`offset_from`](#method.offset_from)
     /// would compute, but with the added precondition that the offset is
     /// guaranteed to be non-negative.  This method is equivalent to
-    /// `usize::from(self.offset_from(origin)).unwrap_unchecked()`,
+    /// `usize::try_from(self.offset_from(origin)).unwrap_unchecked()`,
     /// but it provides slightly more information to the optimizer, which can
     /// sometimes allow it to optimize slightly better with some backends.
     ///
diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
index ed1e3bd4812..0a2f63e3ec6 100644
--- a/library/core/src/ptr/mut_ptr.rs
+++ b/library/core/src/ptr/mut_ptr.rs
@@ -904,7 +904,7 @@ impl<T: ?Sized> *mut T {
     /// This computes the same value that [`offset_from`](#method.offset_from)
     /// would compute, but with the added precondition that the offset is
     /// guaranteed to be non-negative.  This method is equivalent to
-    /// `usize::from(self.offset_from(origin)).unwrap_unchecked()`,
+    /// `usize::try_from(self.offset_from(origin)).unwrap_unchecked()`,
     /// but it provides slightly more information to the optimizer, which can
     /// sometimes allow it to optimize slightly better with some backends.
     ///
diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
index 14367eb09bc..818721062d7 100644
--- a/library/core/src/sync/atomic.rs
+++ b/library/core/src/sync/atomic.rs
@@ -1861,7 +1861,8 @@ macro_rules! if_not_8_bit {
     ($_:ident, $($tt:tt)*) => { $($tt)* };
 }
 
-#[cfg(target_has_atomic_load_store = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic_load_store))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic_load_store = "8"))]
 macro_rules! atomic_int {
     ($cfg_cas:meta,
      $cfg_align:meta,
@@ -2988,7 +2989,8 @@ atomic_int_ptr_sized! {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 fn strongest_failure_ordering(order: Ordering) -> Ordering {
     match order {
         Release => Relaxed,
@@ -3030,7 +3032,8 @@ unsafe fn atomic_load<T: Copy>(dst: *const T, order: Ordering) -> T {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_swap<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_swap`.
@@ -3047,7 +3050,8 @@ unsafe fn atomic_swap<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// Returns the previous value (like __sync_fetch_and_add).
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_add<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_add`.
@@ -3064,7 +3068,8 @@ unsafe fn atomic_add<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// Returns the previous value (like __sync_fetch_and_sub).
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_sub<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_sub`.
@@ -3080,7 +3085,8 @@ unsafe fn atomic_sub<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_compare_exchange<T: Copy>(
     dst: *mut T,
@@ -3115,7 +3121,8 @@ unsafe fn atomic_compare_exchange<T: Copy>(
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_compare_exchange_weak<T: Copy>(
     dst: *mut T,
@@ -3150,7 +3157,8 @@ unsafe fn atomic_compare_exchange_weak<T: Copy>(
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_and<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_and`
@@ -3166,7 +3174,8 @@ unsafe fn atomic_and<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_nand<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_nand`
@@ -3182,7 +3191,8 @@ unsafe fn atomic_nand<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_or<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_or`
@@ -3198,7 +3208,8 @@ unsafe fn atomic_or<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 }
 
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_xor<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_xor`
@@ -3215,7 +3226,8 @@ unsafe fn atomic_xor<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// returns the max value (signed comparison)
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_max<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_max`
@@ -3232,7 +3244,8 @@ unsafe fn atomic_max<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// returns the min value (signed comparison)
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_min<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_min`
@@ -3249,7 +3262,8 @@ unsafe fn atomic_min<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// returns the max value (unsigned comparison)
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_umax<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_umax`
@@ -3266,7 +3280,8 @@ unsafe fn atomic_umax<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 
 /// returns the min value (unsigned comparison)
 #[inline]
-#[cfg(target_has_atomic = "8")]
+#[cfg_attr(not(bootstrap), cfg(target_has_atomic))]
+#[cfg_attr(bootstrap, cfg(target_has_atomic = "8"))]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 unsafe fn atomic_umin<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
     // SAFETY: the caller must uphold the safety contract for `atomic_umin`
diff --git a/library/proc_macro/src/lib.rs b/library/proc_macro/src/lib.rs
index f0e4f5d8a80..938935771d6 100644
--- a/library/proc_macro/src/lib.rs
+++ b/library/proc_macro/src/lib.rs
@@ -74,6 +74,7 @@ pub fn is_available() -> bool {
 ///
 /// This is both the input and output of `#[proc_macro]`, `#[proc_macro_attribute]`
 /// and `#[proc_macro_derive]` definitions.
+#[rustc_diagnostic_item = "TokenStream"]
 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
 #[derive(Clone)]
 pub struct TokenStream(Option<bridge::client::TokenStream>);
@@ -581,7 +582,7 @@ impl fmt::Debug for Span {
 
 /// A line-column pair representing the start or end of a `Span`.
 #[unstable(feature = "proc_macro_span", issue = "54725")]
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
 pub struct LineColumn {
     /// The 1-indexed line in the source file on which the span starts or ends (inclusive).
     #[unstable(feature = "proc_macro_span", issue = "54725")]
diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs
index eb582be012b..839fdc96632 100644
--- a/library/std/src/fs/tests.rs
+++ b/library/std/src/fs/tests.rs
@@ -12,6 +12,8 @@ use crate::time::{Duration, Instant};
 
 use rand::RngCore;
 
+#[cfg(target_os = "macos")]
+use crate::ffi::{c_char, c_int};
 #[cfg(unix)]
 use crate::os::unix::fs::symlink as symlink_dir;
 #[cfg(unix)]
@@ -24,8 +26,6 @@ use crate::os::windows::fs::{symlink_dir, symlink_file};
 use crate::sys::fs::symlink_junction;
 #[cfg(target_os = "macos")]
 use crate::sys::weak::weak;
-#[cfg(target_os = "macos")]
-use libc::{c_char, c_int};
 
 macro_rules! check {
     ($e:expr) => {
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 99cc0186310..762f7a7c9a1 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -358,7 +358,6 @@
 #![feature(const_ip)]
 #![feature(const_ipv4)]
 #![feature(const_ipv6)]
-#![feature(const_socketaddr)]
 #![feature(thread_local_internals)]
 //
 #![default_lib_allocator]
diff --git a/library/std/src/net/socket_addr.rs b/library/std/src/net/socket_addr.rs
index 33b0dfa03e0..1264bae809b 100644
--- a/library/std/src/net/socket_addr.rs
+++ b/library/std/src/net/socket_addr.rs
@@ -133,7 +133,7 @@ impl SocketAddr {
     /// ```
     #[stable(feature = "ip_addr", since = "1.7.0")]
     #[must_use]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn new(ip: IpAddr, port: u16) -> SocketAddr {
         match ip {
             IpAddr::V4(a) => SocketAddr::V4(SocketAddrV4::new(a, port)),
@@ -153,7 +153,7 @@ impl SocketAddr {
     /// ```
     #[must_use]
     #[stable(feature = "ip_addr", since = "1.7.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn ip(&self) -> IpAddr {
         match *self {
             SocketAddr::V4(ref a) => IpAddr::V4(*a.ip()),
@@ -194,7 +194,7 @@ impl SocketAddr {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn port(&self) -> u16 {
         match *self {
             SocketAddr::V4(ref a) => a.port(),
@@ -238,7 +238,7 @@ impl SocketAddr {
     /// ```
     #[must_use]
     #[stable(feature = "sockaddr_checker", since = "1.16.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn is_ipv4(&self) -> bool {
         matches!(*self, SocketAddr::V4(_))
     }
@@ -260,7 +260,7 @@ impl SocketAddr {
     /// ```
     #[must_use]
     #[stable(feature = "sockaddr_checker", since = "1.16.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn is_ipv6(&self) -> bool {
         matches!(*self, SocketAddr::V6(_))
     }
@@ -280,7 +280,7 @@ impl SocketAddrV4 {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[must_use]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn new(ip: Ipv4Addr, port: u16) -> SocketAddrV4 {
         SocketAddrV4 { ip, port }
     }
@@ -297,7 +297,7 @@ impl SocketAddrV4 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn ip(&self) -> &Ipv4Addr {
         &self.ip
     }
@@ -330,7 +330,7 @@ impl SocketAddrV4 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn port(&self) -> u16 {
         self.port
     }
@@ -371,7 +371,7 @@ impl SocketAddrV6 {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[must_use]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn new(ip: Ipv6Addr, port: u16, flowinfo: u32, scope_id: u32) -> SocketAddrV6 {
         SocketAddrV6 { ip, port, flowinfo, scope_id }
     }
@@ -388,7 +388,7 @@ impl SocketAddrV6 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn ip(&self) -> &Ipv6Addr {
         &self.ip
     }
@@ -421,7 +421,7 @@ impl SocketAddrV6 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn port(&self) -> u16 {
         self.port
     }
@@ -464,7 +464,7 @@ impl SocketAddrV6 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn flowinfo(&self) -> u32 {
         self.flowinfo
     }
@@ -504,7 +504,7 @@ impl SocketAddrV6 {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+    #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
     pub const fn scope_id(&self) -> u32 {
         self.scope_id
     }
diff --git a/library/std/src/os/fuchsia/raw.rs b/library/std/src/os/fuchsia/raw.rs
index 060d6e86b6c..ea6b94f2f13 100644
--- a/library/std/src/os/fuchsia/raw.rs
+++ b/library/std/src/os/fuchsia/raw.rs
@@ -24,12 +24,7 @@ pub type pthread_t = c_ulong;
 #[stable(feature = "raw_ext", since = "1.1.0")]
 pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
 
-#[cfg(any(
-    target_arch = "x86",
-    target_arch = "le32",
-    target_arch = "powerpc",
-    target_arch = "arm"
-))]
+#[cfg(any(target_arch = "x86", target_arch = "powerpc", target_arch = "arm"))]
 mod arch {
     use crate::os::raw::{c_long, c_short, c_uint};
 
diff --git a/library/std/src/os/l4re/raw.rs b/library/std/src/os/l4re/raw.rs
index 699e8be33c8..b3f7439f8cd 100644
--- a/library/std/src/os/l4re/raw.rs
+++ b/library/std/src/os/l4re/raw.rs
@@ -26,7 +26,6 @@ pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
 
 #[cfg(any(
     target_arch = "x86",
-    target_arch = "le32",
     target_arch = "m68k",
     target_arch = "powerpc",
     target_arch = "sparc",
diff --git a/library/std/src/os/linux/raw.rs b/library/std/src/os/linux/raw.rs
index c73791d1452..f46028c3a96 100644
--- a/library/std/src/os/linux/raw.rs
+++ b/library/std/src/os/linux/raw.rs
@@ -26,7 +26,6 @@ pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
 
 #[cfg(any(
     target_arch = "x86",
-    target_arch = "le32",
     target_arch = "m68k",
     target_arch = "powerpc",
     target_arch = "sparc",
diff --git a/library/std/src/os/net/mod.rs b/library/std/src/os/net/mod.rs
index 5ec267c41e9..b7046dd7c59 100644
--- a/library/std/src/os/net/mod.rs
+++ b/library/std/src/os/net/mod.rs
@@ -1,4 +1,13 @@
 //! OS-specific networking functionality.
 
+// See cfg macros in `library/std/src/os/mod.rs` for why these platforms must
+// be special-cased during rustdoc generation.
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
 #[cfg(any(target_os = "linux", target_os = "android", doc))]
 pub(super) mod linux_ext;
diff --git a/library/std/src/personality/emcc.rs b/library/std/src/personality/emcc.rs
index f942bdf18c1..cb52ae89b19 100644
--- a/library/std/src/personality/emcc.rs
+++ b/library/std/src/personality/emcc.rs
@@ -1,7 +1,7 @@
 //! On Emscripten Rust panics are wrapped in C++ exceptions, so we just forward
 //! to `__gxx_personality_v0` which is provided by Emscripten.
 
-use libc::c_int;
+use crate::ffi::c_int;
 use unwind as uw;
 
 // This is required by the compiler to exist (e.g., it's a lang item), but it's
diff --git a/library/std/src/personality/gcc.rs b/library/std/src/personality/gcc.rs
index 5fc1b91a1c3..41c0fe725a5 100644
--- a/library/std/src/personality/gcc.rs
+++ b/library/std/src/personality/gcc.rs
@@ -37,7 +37,8 @@
 //! and the last personality routine transfers control to the catch block.
 
 use super::dwarf::eh::{self, EHAction, EHContext};
-use libc::{c_int, uintptr_t};
+use crate::ffi::c_int;
+use libc::uintptr_t;
 use unwind as uw;
 
 // Register ids were lifted from LLVM's TargetLowering::getExceptionPointerRegister()
diff --git a/library/std/src/sync/mpmc/array.rs b/library/std/src/sync/mpmc/array.rs
index c1e3e48b044..c6bb09b0417 100644
--- a/library/std/src/sync/mpmc/array.rs
+++ b/library/std/src/sync/mpmc/array.rs
@@ -319,19 +319,10 @@ impl<T> Channel<T> {
     ) -> Result<(), SendTimeoutError<T>> {
         let token = &mut Token::default();
         loop {
-            // Try sending a message several times.
-            let backoff = Backoff::new();
-            loop {
-                if self.start_send(token) {
-                    let res = unsafe { self.write(token, msg) };
-                    return res.map_err(SendTimeoutError::Disconnected);
-                }
-
-                if backoff.is_completed() {
-                    break;
-                } else {
-                    backoff.spin_light();
-                }
+            // Try sending a message.
+            if self.start_send(token) {
+                let res = unsafe { self.write(token, msg) };
+                return res.map_err(SendTimeoutError::Disconnected);
             }
 
             if let Some(d) = deadline {
@@ -379,6 +370,7 @@ impl<T> Channel<T> {
     pub(crate) fn recv(&self, deadline: Option<Instant>) -> Result<T, RecvTimeoutError> {
         let token = &mut Token::default();
         loop {
+            // Try receiving a message.
             if self.start_recv(token) {
                 let res = unsafe { self.read(token) };
                 return res.map_err(|_| RecvTimeoutError::Disconnected);
diff --git a/library/std/src/sync/mpmc/utils.rs b/library/std/src/sync/mpmc/utils.rs
index cfe42750d52..d053d69e26e 100644
--- a/library/std/src/sync/mpmc/utils.rs
+++ b/library/std/src/sync/mpmc/utils.rs
@@ -105,10 +105,8 @@ impl Backoff {
 
     /// Backs off using lightweight spinning.
     ///
-    /// This method should be used for:
-    ///     - Retrying an operation because another thread made progress. i.e. on CAS failure.
-    ///     - Waiting for an operation to complete by spinning optimistically for a few iterations
-    ///     before falling back to parking the thread (see `Backoff::is_completed`).
+    /// This method should be used for retrying an operation because another thread made
+    /// progress. i.e. on CAS failure.
     #[inline]
     pub fn spin_light(&self) {
         let step = self.step.get().min(SPIN_LIMIT);
@@ -134,10 +132,4 @@ impl Backoff {
 
         self.step.set(self.step.get() + 1);
     }
-
-    /// Returns `true` if quadratic backoff has completed and parking the thread is advised.
-    #[inline]
-    pub fn is_completed(&self) -> bool {
-        self.step.get() > SPIN_LIMIT
-    }
 }
diff --git a/library/std/src/sys/common/alloc.rs b/library/std/src/sys/common/alloc.rs
index 3edbe728077..403a5e627f1 100644
--- a/library/std/src/sys/common/alloc.rs
+++ b/library/std/src/sys/common/alloc.rs
@@ -7,6 +7,7 @@ use crate::ptr;
 #[cfg(any(
     target_arch = "x86",
     target_arch = "arm",
+    target_arch = "m68k",
     target_arch = "mips",
     target_arch = "powerpc",
     target_arch = "powerpc64",
diff --git a/library/std/src/sys/unix/thread_local_dtor.rs b/library/std/src/sys/unix/thread_local_dtor.rs
index c31fb3a48da..236d2f2ee29 100644
--- a/library/std/src/sys/unix/thread_local_dtor.rs
+++ b/library/std/src/sys/unix/thread_local_dtor.rs
@@ -11,13 +11,7 @@
 // Note, however, that we run on lots older linuxes, as well as cross
 // compiling from a newer linux to an older linux, so we also have a
 // fallback implementation to use as well.
-#[cfg(any(
-    target_os = "linux",
-    target_os = "fuchsia",
-    target_os = "redox",
-    target_os = "emscripten"
-))]
-#[cfg_attr(target_family = "wasm", allow(unused))] // might remain unused depending on target details (e.g. wasm32-unknown-emscripten)
+#[cfg(any(target_os = "linux", target_os = "fuchsia", target_os = "redox"))]
 pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
     use crate::mem;
     use crate::sys_common::thread_local_dtor::register_dtor_fallback;
@@ -89,7 +83,8 @@ pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
     }
 }
 
-#[cfg(any(target_os = "vxworks", target_os = "horizon"))]
+#[cfg(any(target_os = "vxworks", target_os = "horizon", target_os = "emscripten"))]
+#[cfg_attr(target_family = "wasm", allow(unused))] // might remain unused depending on target details (e.g. wasm32-unknown-emscripten)
 pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
     use crate::sys_common::thread_local_dtor::register_dtor_fallback;
     register_dtor_fallback(t, dtor);
diff --git a/library/std/src/sys/windows/thread_parking.rs b/library/std/src/sys/windows/thread_parking.rs
index 5d43676adbb..eb9167cd855 100644
--- a/library/std/src/sys/windows/thread_parking.rs
+++ b/library/std/src/sys/windows/thread_parking.rs
@@ -221,7 +221,7 @@ impl Parker {
 
 fn keyed_event_handle() -> c::HANDLE {
     const INVALID: c::HANDLE = ptr::invalid_mut(!0);
-    static HANDLE: AtomicPtr<libc::c_void> = AtomicPtr::new(INVALID);
+    static HANDLE: AtomicPtr<crate::ffi::c_void> = AtomicPtr::new(INVALID);
     match HANDLE.load(Relaxed) {
         INVALID => {
             let mut handle = c::INVALID_HANDLE_VALUE;
diff --git a/library/std/src/sys_common/net.rs b/library/std/src/sys_common/net.rs
index fad4a63331b..2c38dfecf97 100644
--- a/library/std/src/sys_common/net.rs
+++ b/library/std/src/sys_common/net.rs
@@ -14,7 +14,7 @@ use crate::sys::net::{cvt, cvt_gai, cvt_r, init, wrlen_t, Socket};
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 use crate::time::Duration;
 
-use libc::{c_int, c_void};
+use crate::ffi::{c_int, c_void};
 
 cfg_if::cfg_if! {
     if #[cfg(any(
@@ -47,7 +47,7 @@ cfg_if::cfg_if! {
         target_os = "dragonfly", target_os = "freebsd",
         target_os = "openbsd", target_os = "netbsd",
         target_os = "solaris", target_os = "illumos"))] {
-        use libc::c_uchar;
+        use crate::ffi::c_uchar;
         type IpV4MultiCastType = c_uchar;
     } else {
         type IpV4MultiCastType = c_int;
@@ -127,8 +127,8 @@ fn to_ipv6mr_interface(value: u32) -> c_int {
 }
 
 #[cfg(not(target_os = "android"))]
-fn to_ipv6mr_interface(value: u32) -> libc::c_uint {
-    value as libc::c_uint
+fn to_ipv6mr_interface(value: u32) -> crate::ffi::c_uint {
+    value as crate::ffi::c_uint
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/library/std/src/time.rs b/library/std/src/time.rs
index ecd06ebf743..acf9c29083f 100644
--- a/library/std/src/time.rs
+++ b/library/std/src/time.rs
@@ -1,6 +1,6 @@
 //! Temporal quantification.
 //!
-//! # Examples:
+//! # Examples
 //!
 //! There are multiple ways to create a new [`Duration`]:
 //!
diff --git a/library/std/tests/run-time-detect.rs b/library/std/tests/run-time-detect.rs
index 1a2c1255661..bf3c81fcc98 100644
--- a/library/std/tests/run-time-detect.rs
+++ b/library/std/tests/run-time-detect.rs
@@ -120,16 +120,13 @@ fn x86_all() {
     println!("avx512dq: {:?}", is_x86_feature_detected!("avx512dq"));
     println!("avx512er: {:?}", is_x86_feature_detected!("avx512er"));
     println!("avx512f: {:?}", is_x86_feature_detected!("avx512f"));
-    println!("avx512gfni: {:?}", is_x86_feature_detected!("avx512gfni"));
     println!("avx512ifma: {:?}", is_x86_feature_detected!("avx512ifma"));
     println!("avx512pf: {:?}", is_x86_feature_detected!("avx512pf"));
-    println!("avx512vaes: {:?}", is_x86_feature_detected!("avx512vaes"));
     println!("avx512vbmi2: {:?}", is_x86_feature_detected!("avx512vbmi2"));
     println!("avx512vbmi: {:?}", is_x86_feature_detected!("avx512vbmi"));
     println!("avx512vl: {:?}", is_x86_feature_detected!("avx512vl"));
     println!("avx512vnni: {:?}", is_x86_feature_detected!("avx512vnni"));
     println!("avx512vp2intersect: {:?}", is_x86_feature_detected!("avx512vp2intersect"));
-    println!("avx512vpclmulqdq: {:?}", is_x86_feature_detected!("avx512vpclmulqdq"));
     println!("avx512vpopcntdq: {:?}", is_x86_feature_detected!("avx512vpopcntdq"));
     println!("avx: {:?}", is_x86_feature_detected!("avx"));
     println!("bmi1: {:?}", is_x86_feature_detected!("bmi1"));
@@ -138,6 +135,7 @@ fn x86_all() {
     println!("f16c: {:?}", is_x86_feature_detected!("f16c"));
     println!("fma: {:?}", is_x86_feature_detected!("fma"));
     println!("fxsr: {:?}", is_x86_feature_detected!("fxsr"));
+    println!("gfni: {:?}", is_x86_feature_detected!("gfni"));
     println!("lzcnt: {:?}", is_x86_feature_detected!("lzcnt"));
     //println!("movbe: {:?}", is_x86_feature_detected!("movbe")); // movbe is unsupported as a target feature
     println!("pclmulqdq: {:?}", is_x86_feature_detected!("pclmulqdq"));
@@ -154,6 +152,8 @@ fn x86_all() {
     println!("sse: {:?}", is_x86_feature_detected!("sse"));
     println!("ssse3: {:?}", is_x86_feature_detected!("ssse3"));
     println!("tbm: {:?}", is_x86_feature_detected!("tbm"));
+    println!("vaes: {:?}", is_x86_feature_detected!("vaes"));
+    println!("vpclmulqdq: {:?}", is_x86_feature_detected!("vpclmulqdq"));
     println!("xsave: {:?}", is_x86_feature_detected!("xsave"));
     println!("xsavec: {:?}", is_x86_feature_detected!("xsavec"));
     println!("xsaveopt: {:?}", is_x86_feature_detected!("xsaveopt"));
diff --git a/library/stdarch b/library/stdarch
-Subproject 790411f93c4b5eada3c23abb4c9a063fb0b24d9
+Subproject a0c30f3e3c75adcd6ee7efc94014ebcead61c50
diff --git a/library/test/src/cli.rs b/library/test/src/cli.rs
index 796796e07a9..9d22ebbee87 100644
--- a/library/test/src/cli.rs
+++ b/library/test/src/cli.rs
@@ -309,7 +309,8 @@ fn parse_opts_impl(matches: getopts::Matches) -> OptRes {
 // FIXME: Copied from librustc_ast until linkage errors are resolved. Issue #47566
 fn is_nightly() -> bool {
     // Whether this is a feature-staged build, i.e., on the beta or stable channel
-    let disable_unstable_features = option_env!("CFG_DISABLE_UNSTABLE_FEATURES").is_some();
+    let disable_unstable_features =
+        option_env!("CFG_DISABLE_UNSTABLE_FEATURES").map(|s| s != "0").unwrap_or(false);
     // Whether we should enable unstable features for bootstrapping
     let bootstrap = env::var("RUSTC_BOOTSTRAP").is_ok();
 
diff --git a/library/test/src/console.rs b/library/test/src/console.rs
index 24cbe035f2f..1ee68c8540b 100644
--- a/library/test/src/console.rs
+++ b/library/test/src/console.rs
@@ -53,6 +53,7 @@ pub struct ConsoleTestState {
     pub metrics: MetricMap,
     pub failures: Vec<(TestDesc, Vec<u8>)>,
     pub not_failures: Vec<(TestDesc, Vec<u8>)>,
+    pub ignores: Vec<(TestDesc, Vec<u8>)>,
     pub time_failures: Vec<(TestDesc, Vec<u8>)>,
     pub options: Options,
 }
@@ -76,6 +77,7 @@ impl ConsoleTestState {
             metrics: MetricMap::new(),
             failures: Vec::new(),
             not_failures: Vec::new(),
+            ignores: Vec::new(),
             time_failures: Vec::new(),
             options: opts.options,
         })
@@ -194,7 +196,10 @@ fn handle_test_result(st: &mut ConsoleTestState, completed_test: CompletedTest)
             st.passed += 1;
             st.not_failures.push((test, stdout));
         }
-        TestResult::TrIgnored => st.ignored += 1,
+        TestResult::TrIgnored => {
+            st.ignored += 1;
+            st.ignores.push((test, stdout));
+        }
         TestResult::TrBench(bs) => {
             st.metrics.insert_metric(
                 test.name.as_slice(),
diff --git a/library/test/src/formatters/terse.rs b/library/test/src/formatters/terse.rs
index 0837ab16905..a431acfbc27 100644
--- a/library/test/src/formatters/terse.rs
+++ b/library/test/src/formatters/terse.rs
@@ -254,6 +254,15 @@ impl<T: Write> OutputFormatter for TerseFormatter<T> {
 
         self.write_plain("\n\n")?;
 
+        // Custom handling of cases where there is only 1 test to execute and that test was ignored.
+        // We want to show more detailed information(why was the test ignored) for investigation purposes.
+        if self.total_test_count == 1 && state.ignores.len() == 1 {
+            let test_desc = &state.ignores[0].0;
+            if let Some(im) = test_desc.ignore_message {
+                self.write_plain(format!("test: {}, ignore_message: {}\n\n", test_desc.name, im))?;
+            }
+        }
+
         Ok(success)
     }
 }
diff --git a/library/test/src/tests.rs b/library/test/src/tests.rs
index 3a0260f86cf..44776fb0a31 100644
--- a/library/test/src/tests.rs
+++ b/library/test/src/tests.rs
@@ -790,6 +790,7 @@ fn should_sort_failures_before_printing_them() {
         failures: vec![(test_b, Vec::new()), (test_a, Vec::new())],
         options: Options::new(),
         not_failures: Vec::new(),
+        ignores: Vec::new(),
         time_failures: Vec::new(),
     };
 
diff --git a/src/bootstrap/bin/main.rs b/src/bootstrap/bin/main.rs
index be69f819c64..3856bb64fb3 100644
--- a/src/bootstrap/bin/main.rs
+++ b/src/bootstrap/bin/main.rs
@@ -16,12 +16,17 @@ fn main() {
     let mut build_lock;
     let _build_lock_guard;
     if cfg!(any(unix, windows)) {
-        build_lock = fd_lock::RwLock::new(t!(std::fs::File::create(config.out.join("lock"))));
+        let path = config.out.join("lock");
+        build_lock = fd_lock::RwLock::new(t!(std::fs::File::create(&path)));
         _build_lock_guard = match build_lock.try_write() {
             Ok(lock) => lock,
             err => {
-                println!("warning: build directory locked, waiting for lock");
                 drop(err);
+                if let Some(pid) = get_lock_owner(&path) {
+                    println!("warning: build directory locked by process {pid}, waiting for lock");
+                } else {
+                    println!("warning: build directory locked, waiting for lock");
+                }
                 t!(build_lock.write())
             }
         };
@@ -98,3 +103,30 @@ fn check_version(config: &Config) -> Option<String> {
 
     Some(msg)
 }
+
+/// Get the PID of the process which took the write lock by
+/// parsing `/proc/locks`.
+#[cfg(target_os = "linux")]
+fn get_lock_owner(f: &std::path::Path) -> Option<u64> {
+    use std::fs::File;
+    use std::io::{BufRead, BufReader};
+    use std::os::unix::fs::MetadataExt;
+
+    let lock_inode = std::fs::metadata(f).ok()?.ino();
+    let lockfile = File::open("/proc/locks").ok()?;
+    BufReader::new(lockfile).lines().find_map(|line| {
+        //                       pid--vvvvvv       vvvvvvv--- inode
+        // 21: FLOCK  ADVISORY  WRITE 359238 08:02:3719774 0 EOF
+        let line = line.ok()?;
+        let parts = line.split_whitespace().collect::<Vec<_>>();
+        let (pid, inode) = (parts[4].parse::<u64>().ok()?, &parts[5]);
+        let inode = inode.rsplit_once(':')?.1.parse::<u64>().ok()?;
+        if inode == lock_inode { Some(pid) } else { None }
+    })
+}
+
+#[cfg(not(target_os = "linux"))]
+fn get_lock_owner(_: &std::path::Path) -> Option<u64> {
+    // FIXME: Implement on other OS's
+    None
+}
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 9cf43fc7a21..abdd12127d3 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -712,7 +712,7 @@ class RustBuild(object):
 
     def build_bootstrap(self, color):
         """Build bootstrap"""
-        print("Building rustbuild")
+        print("Building bootstrap")
         build_dir = os.path.join(self.build_dir, "bootstrap")
         if self.clean and os.path.exists(build_dir):
             shutil.rmtree(build_dir)
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index b41d60d51a8..165502b0a41 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -65,6 +65,7 @@ pub struct Config {
     pub verbose: usize,
     pub submodules: Option<bool>,
     pub compiler_docs: bool,
+    pub library_docs_private_items: bool,
     pub docs_minification: bool,
     pub docs: bool,
     pub locked_deps: bool,
@@ -606,6 +607,7 @@ define_config! {
         rustfmt: Option<PathBuf> = "rustfmt",
         docs: Option<bool> = "docs",
         compiler_docs: Option<bool> = "compiler-docs",
+        library_docs_private_items: Option<bool> = "library-docs-private-items",
         docs_minification: Option<bool> = "docs-minification",
         submodules: Option<bool> = "submodules",
         gdb: Option<String> = "gdb",
@@ -965,6 +967,9 @@ impl Config {
         config.changelog_seen = toml.changelog_seen;
 
         let build = toml.build.unwrap_or_default();
+        if let Some(file_build) = build.build {
+            config.build = TargetSelection::from_user(&file_build);
+        };
 
         set(&mut config.out, flags.build_dir.or_else(|| build.build_dir.map(PathBuf::from)));
         // NOTE: Bootstrap spawns various commands with different working directories.
@@ -1015,6 +1020,7 @@ impl Config {
         config.submodules = build.submodules;
         set(&mut config.low_priority, build.low_priority);
         set(&mut config.compiler_docs, build.compiler_docs);
+        set(&mut config.library_docs_private_items, build.library_docs_private_items);
         set(&mut config.docs_minification, build.docs_minification);
         set(&mut config.docs, build.docs);
         set(&mut config.locked_deps, build.locked_deps);
diff --git a/src/bootstrap/config/tests.rs b/src/bootstrap/config/tests.rs
index c30c9131745..681ecbfeb5b 100644
--- a/src/bootstrap/config/tests.rs
+++ b/src/bootstrap/config/tests.rs
@@ -19,6 +19,13 @@ fn download_ci_llvm() {
     assert_eq!(parse_llvm(""), if_available);
     assert_eq!(parse_llvm("rust.channel = \"dev\""), if_available);
     assert!(!parse_llvm("rust.channel = \"stable\""));
+    assert!(parse_llvm("build.build = \"x86_64-unknown-linux-gnu\""));
+    assert!(parse_llvm(
+        "llvm.assertions = true \r\n build.build = \"x86_64-unknown-linux-gnu\" \r\n llvm.download-ci-llvm = \"if-available\""
+    ));
+    assert!(!parse_llvm(
+        "llvm.assertions = true \r\n build.build = \"aarch64-apple-darwin\" \r\n llvm.download-ci-llvm = \"if-available\""
+    ));
 }
 
 // FIXME: add test for detecting `src` and `out`
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 2e4f753965d..02e35d2436e 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -392,19 +392,29 @@ impl Step for Rustc {
             t!(fs::create_dir_all(image.join("bin")));
             builder.cp_r(&src.join("bin"), &image.join("bin"));
 
-            builder.install(&builder.rustdoc(compiler), &image.join("bin"), 0o755);
+            if builder
+                .config
+                .tools
+                .as_ref()
+                .map_or(true, |tools| tools.iter().any(|tool| tool == "rustdoc"))
+            {
+                let rustdoc = builder.rustdoc(compiler);
+                builder.install(&rustdoc, &image.join("bin"), 0o755);
+            }
 
-            let ra_proc_macro_srv = builder
-                .ensure(tool::RustAnalyzerProcMacroSrv {
+            if let Some(ra_proc_macro_srv) = builder.ensure_if_default(
+                tool::RustAnalyzerProcMacroSrv {
                     compiler: builder.compiler_for(
                         compiler.stage,
                         builder.config.build,
                         compiler.host,
                     ),
                     target: compiler.host,
-                })
-                .expect("rust-analyzer-proc-macro-server always builds");
-            builder.install(&ra_proc_macro_srv, &image.join("libexec"), 0o755);
+                },
+                builder.kind,
+            ) {
+                builder.install(&ra_proc_macro_srv, &image.join("libexec"), 0o755);
+            }
 
             let libdir_relative = builder.libdir_relative(compiler);
 
@@ -952,7 +962,7 @@ impl Step for PlainSourceTarball {
             "Cargo.toml",
             "Cargo.lock",
         ];
-        let src_dirs = ["src", "compiler", "library"];
+        let src_dirs = ["src", "compiler", "library", "tests"];
 
         copy_src_dirs(builder, &builder.src, &src_dirs, &[], &plain_dst_src);
 
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index 9bad9046ecc..7f8aa2573dd 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -597,6 +597,9 @@ fn doc_std(
             .arg("--resource-suffix")
             .arg(&builder.version)
             .args(extra_args);
+        if builder.config.library_docs_private_items {
+            cargo.arg("--document-private-items").arg("--document-hidden-items");
+        }
         builder.run(&mut cargo.into());
     };
 
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index d44b96cfb99..267aa3278d8 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -110,7 +110,7 @@ use std::fs::{self, File};
 use std::io;
 use std::io::ErrorKind;
 use std::path::{Path, PathBuf};
-use std::process::Command;
+use std::process::{Command, Stdio};
 use std::str;
 
 use build_helper::ci::CiEnv;
@@ -203,7 +203,6 @@ const EXTRA_CHECK_CFGS: &[(Option<Mode>, &'static str, Option<&[&'static str]>)]
     (None, "bootstrap", None),
     (Some(Mode::Rustc), "parallel_compiler", None),
     (Some(Mode::ToolRustc), "parallel_compiler", None),
-    (Some(Mode::ToolRustc), "emulate_second_only_system", None),
     (Some(Mode::Codegen), "parallel_compiler", None),
     (Some(Mode::Std), "stdarch_intel_sde", None),
     (Some(Mode::Std), "no_fp_fmt_parse", None),
@@ -214,18 +213,9 @@ const EXTRA_CHECK_CFGS: &[(Option<Mode>, &'static str, Option<&[&'static str]>)]
     (Some(Mode::Std), "backtrace_in_libstd", None),
     /* Extra values not defined in the built-in targets yet, but used in std */
     (Some(Mode::Std), "target_env", Some(&["libnx"])),
-    (Some(Mode::Std), "target_os", Some(&["watchos"])),
-    (
-        Some(Mode::Std),
-        "target_arch",
-        Some(&["asmjs", "spirv", "nvptx", "nvptx64", "le32", "xtensa"]),
-    ),
+    // (Some(Mode::Std), "target_os", Some(&[])),
+    (Some(Mode::Std), "target_arch", Some(&["asmjs", "spirv", "nvptx", "xtensa"])),
     /* Extra names used by dependencies */
-    // FIXME: Used by rustfmt is their test but is invalid (neither cargo nor bootstrap ever set
-    // this config) should probably by removed or use a allow attribute.
-    (Some(Mode::ToolRustc), "release", None),
-    // FIXME: Used by stdarch in their test, should use a allow attribute instead.
-    (Some(Mode::Std), "dont_compile_me", None),
     // FIXME: Used by serde_json, but we should not be triggering on external dependencies.
     (Some(Mode::Rustc), "no_btreemap_remove_entry", None),
     (Some(Mode::ToolRustc), "no_btreemap_remove_entry", None),
@@ -235,8 +225,12 @@ const EXTRA_CHECK_CFGS: &[(Option<Mode>, &'static str, Option<&[&'static str]>)]
     // FIXME: Used by proc-macro2, but we should not be triggering on external dependencies.
     (Some(Mode::Rustc), "span_locations", None),
     (Some(Mode::ToolRustc), "span_locations", None),
-    // Can be passed in RUSTFLAGS to prevent direct syscalls in rustix.
-    (None, "rustix_use_libc", None),
+    // FIXME: Used by rustix, but we should not be triggering on external dependencies.
+    (Some(Mode::Rustc), "rustix_use_libc", None),
+    (Some(Mode::ToolRustc), "rustix_use_libc", None),
+    // FIXME: Used by filetime, but we should not be triggering on external dependencies.
+    (Some(Mode::Rustc), "emulate_second_only_system", None),
+    (Some(Mode::ToolRustc), "emulate_second_only_system", None),
 ];
 
 /// A structure representing a Rust compiler.
@@ -662,12 +656,32 @@ impl Build {
 
         // Try passing `--progress` to start, then run git again without if that fails.
         let update = |progress: bool| {
-            let mut git = Command::new("git");
+            // Git is buggy and will try to fetch submodules from the tracking branch for *this* repository,
+            // even though that has no relation to the upstream for the submodule.
+            let current_branch = {
+                let output = self
+                    .config
+                    .git()
+                    .args(["symbolic-ref", "--short", "HEAD"])
+                    .stderr(Stdio::inherit())
+                    .output();
+                let output = t!(output);
+                if output.status.success() {
+                    Some(String::from_utf8(output.stdout).unwrap().trim().to_owned())
+                } else {
+                    None
+                }
+            };
+
+            let mut git = self.config.git();
+            if let Some(branch) = current_branch {
+                git.arg("-c").arg(format!("branch.{branch}.remote=origin"));
+            }
             git.args(&["submodule", "update", "--init", "--recursive", "--depth=1"]);
             if progress {
                 git.arg("--progress");
             }
-            git.arg(relative_path).current_dir(&self.config.src);
+            git.arg(relative_path);
             git
         };
         // NOTE: doesn't use `try_run` because this shouldn't print an error if it fails.
@@ -1431,6 +1445,14 @@ impl Build {
             return Vec::new();
         }
 
+        if !stamp.exists() {
+            eprintln!(
+                "Error: Unable to find the stamp file {}, did you try to keep a nonexistent build stage?",
+                stamp.display()
+            );
+            crate::detail_exit(1);
+        }
+
         let mut paths = Vec::new();
         let contents = t!(fs::read(stamp), &stamp);
         // This is the method we use for extracting paths from the stamp file passed to us. See
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index cb5706ca0a6..3acc2d4b5c4 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -180,43 +180,40 @@ pub(crate) fn is_ci_llvm_available(config: &Config, asserts: bool) -> bool {
     // https://doc.rust-lang.org/rustc/platform-support.html#tier-1
     let supported_platforms = [
         // tier 1
-        "aarch64-unknown-linux-gnu",
-        "i686-pc-windows-gnu",
-        "i686-pc-windows-msvc",
-        "i686-unknown-linux-gnu",
-        "x86_64-unknown-linux-gnu",
-        "x86_64-apple-darwin",
-        "x86_64-pc-windows-gnu",
-        "x86_64-pc-windows-msvc",
+        ("aarch64-unknown-linux-gnu", false),
+        ("i686-pc-windows-gnu", false),
+        ("i686-pc-windows-msvc", false),
+        ("i686-unknown-linux-gnu", false),
+        ("x86_64-unknown-linux-gnu", true),
+        ("x86_64-apple-darwin", true),
+        ("x86_64-pc-windows-gnu", true),
+        ("x86_64-pc-windows-msvc", true),
         // tier 2 with host tools
-        "aarch64-apple-darwin",
-        "aarch64-pc-windows-msvc",
-        "aarch64-unknown-linux-musl",
-        "arm-unknown-linux-gnueabi",
-        "arm-unknown-linux-gnueabihf",
-        "armv7-unknown-linux-gnueabihf",
-        "mips-unknown-linux-gnu",
-        "mips64-unknown-linux-gnuabi64",
-        "mips64el-unknown-linux-gnuabi64",
-        "mipsel-unknown-linux-gnu",
-        "powerpc-unknown-linux-gnu",
-        "powerpc64-unknown-linux-gnu",
-        "powerpc64le-unknown-linux-gnu",
-        "riscv64gc-unknown-linux-gnu",
-        "s390x-unknown-linux-gnu",
-        "x86_64-unknown-freebsd",
-        "x86_64-unknown-illumos",
-        "x86_64-unknown-linux-musl",
-        "x86_64-unknown-netbsd",
+        ("aarch64-apple-darwin", false),
+        ("aarch64-pc-windows-msvc", false),
+        ("aarch64-unknown-linux-musl", false),
+        ("arm-unknown-linux-gnueabi", false),
+        ("arm-unknown-linux-gnueabihf", false),
+        ("armv7-unknown-linux-gnueabihf", false),
+        ("mips-unknown-linux-gnu", false),
+        ("mips64-unknown-linux-gnuabi64", false),
+        ("mips64el-unknown-linux-gnuabi64", false),
+        ("mipsel-unknown-linux-gnu", false),
+        ("powerpc-unknown-linux-gnu", false),
+        ("powerpc64-unknown-linux-gnu", false),
+        ("powerpc64le-unknown-linux-gnu", false),
+        ("riscv64gc-unknown-linux-gnu", false),
+        ("s390x-unknown-linux-gnu", false),
+        ("x86_64-unknown-freebsd", false),
+        ("x86_64-unknown-illumos", false),
+        ("x86_64-unknown-linux-musl", false),
+        ("x86_64-unknown-netbsd", false),
     ];
-    if !supported_platforms.contains(&&*config.build.triple) {
-        return false;
-    }
 
-    let triple = &*config.build.triple;
-    if (triple == "aarch64-unknown-linux-gnu" || triple.contains("i686")) && asserts {
-        // No alt builder for aarch64-unknown-linux-gnu today.
-        return false;
+    if !supported_platforms.contains(&(&*config.build.triple, asserts)) {
+        if asserts == true || !supported_platforms.contains(&(&*config.build.triple, true)) {
+            return false;
+        }
     }
 
     if CiEnv::is_ci() {
diff --git a/src/bootstrap/tool.rs b/src/bootstrap/tool.rs
index 9a2100c2fb7..ca5f500f93b 100644
--- a/src/bootstrap/tool.rs
+++ b/src/bootstrap/tool.rs
@@ -765,9 +765,15 @@ impl Step for RustAnalyzerProcMacroSrv {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        let builder = run.builder;
         // Allow building `rust-analyzer-proc-macro-srv` both as part of the `rust-analyzer` and as a stand-alone tool.
         run.path("src/tools/rust-analyzer")
             .path("src/tools/rust-analyzer/crates/proc-macro-srv-cli")
+            .default_condition(builder.config.tools.as_ref().map_or(true, |tools| {
+                tools
+                    .iter()
+                    .any(|tool| tool == "rust-analyzer" || tool == "rust-analyzer-proc-macro-srv")
+            }))
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
index 6bdc88e18f5..5feba4e0605 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
@@ -81,7 +81,7 @@ ENV RUST_CONFIGURE_ARGS \
       --set rust.jemalloc \
       --set rust.use-lld=true \
       --set rust.lto=thin
-ENV SCRIPT ../src/ci/pgo.sh python3 ../x.py dist \
+ENV SCRIPT python3 ../src/ci/stage-build.py python3 ../x.py dist \
     --host $HOSTS --target $HOSTS \
     --include-default-paths \
     build-manifest bootstrap
diff --git a/src/ci/docker/host-x86_64/mingw-check/validate-toolstate.sh b/src/ci/docker/host-x86_64/mingw-check/validate-toolstate.sh
index c6d728eb80d..0b06f5e3623 100755
--- a/src/ci/docker/host-x86_64/mingw-check/validate-toolstate.sh
+++ b/src/ci/docker/host-x86_64/mingw-check/validate-toolstate.sh
@@ -9,11 +9,5 @@ git clone --depth=1 https://github.com/rust-lang-nursery/rust-toolstate.git
 cd rust-toolstate
 python3 "../../src/tools/publish_toolstate.py" "$(git rev-parse HEAD)" \
     "$(git log --format=%s -n1 HEAD)" "" ""
-# Only check maintainers if this build is supposed to publish toolstate.
-# Builds that are not supposed to publish don't have the access token.
-if [ -n "${TOOLSTATE_PUBLISH+is_set}" ]; then
-  TOOLSTATE_VALIDATE_MAINTAINERS_REPO=rust-lang/rust python3 \
-      "../../src/tools/publish_toolstate.py"
-fi
 cd ..
 rm -rf rust-toolstate
diff --git a/src/ci/github-actions/ci.yml b/src/ci/github-actions/ci.yml
index a466777dd46..5e676a470a0 100644
--- a/src/ci/github-actions/ci.yml
+++ b/src/ci/github-actions/ci.yml
@@ -629,9 +629,7 @@ jobs:
 
           - name: i686-mingw-1
             env:
-              RUST_CONFIGURE_ARGS: >-
-                --build=i686-pc-windows-gnu
-                --set llvm.allow-old-toolchain
+              RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
               SCRIPT: make ci-mingw-subset-1
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
@@ -641,9 +639,7 @@ jobs:
 
           - name: i686-mingw-2
             env:
-              RUST_CONFIGURE_ARGS: >-
-                --build=i686-pc-windows-gnu
-                --set llvm.allow-old-toolchain
+              RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
               SCRIPT: make ci-mingw-subset-2
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
@@ -657,7 +653,6 @@ jobs:
               RUST_CONFIGURE_ARGS: >-
                 --build=x86_64-pc-windows-gnu
                 --enable-profiler
-                --set llvm.allow-old-toolchain
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
               NO_DOWNLOAD_CI_LLVM: 1
@@ -670,7 +665,6 @@ jobs:
               RUST_CONFIGURE_ARGS: >-
                 --build=x86_64-pc-windows-gnu
                 --enable-profiler
-                --set llvm.allow-old-toolchain
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
               NO_DOWNLOAD_CI_LLVM: 1
@@ -686,7 +680,7 @@ jobs:
                 --enable-full-tools
                 --enable-profiler
                 --set rust.lto=thin
-              SCRIPT: PGO_HOST=x86_64-pc-windows-msvc src/ci/pgo.sh python x.py dist bootstrap --include-default-paths
+              SCRIPT: PGO_HOST=x86_64-pc-windows-msvc python src/ci/stage-build.py python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             <<: *job-windows-xl
 
@@ -722,7 +716,6 @@ jobs:
                 --build=i686-pc-windows-gnu
                 --enable-full-tools
                 --enable-profiler
-                --set llvm.allow-old-toolchain
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
               NO_DOWNLOAD_CI_LLVM: 1
@@ -738,7 +731,6 @@ jobs:
                 --build=x86_64-pc-windows-gnu
                 --enable-full-tools
                 --enable-profiler
-                --set llvm.allow-old-toolchain
               # We are intentionally allowing an old toolchain on this builder (and that's
               # incompatible with LLVM downloads today).
               NO_DOWNLOAD_CI_LLVM: 1
diff --git a/src/ci/scripts/install-mingw.sh b/src/ci/scripts/install-mingw.sh
index 1685fbbbbba..7eccb9b8650 100755
--- a/src/ci/scripts/install-mingw.sh
+++ b/src/ci/scripts/install-mingw.sh
@@ -2,24 +2,6 @@
 # If we need to download a custom MinGW, do so here and set the path
 # appropriately.
 #
-# Here we also do a pretty heinous thing which is to mangle the MinGW
-# installation we just downloaded. Currently, as of this writing, we're using
-# MinGW-w64 builds of gcc, and that's currently at 6.3.0. We use 6.3.0 as it
-# appears to be the first version which contains a fix for #40546, builds
-# randomly failing during LLVM due to ar.exe/ranlib.exe failures.
-#
-# Unfortunately, though, 6.3.0 *also* is the first version of MinGW-w64 builds
-# to contain a regression in gdb (#40184). As a result if we were to use the
-# gdb provided (7.11.1) then we would fail all debuginfo tests.
-#
-# In order to fix spurious failures (pretty high priority) we use 6.3.0. To
-# avoid disabling gdb tests we download an *old* version of gdb, specifically
-# that found inside the 6.2.0 distribution. We then overwrite the 6.3.0 gdb
-# with the 6.2.0 gdb to get tests passing.
-#
-# Note that we don't literally overwrite the gdb.exe binary because it appears
-# to just use gdborig.exe, so that's the binary we deal with instead.
-#
 # Otherwise install MinGW through `pacman`
 
 set -euo pipefail
@@ -27,8 +9,8 @@ IFS=$'\n\t'
 
 source "$(cd "$(dirname "$0")" && pwd)/../shared.sh"
 
-MINGW_ARCHIVE_32="i686-6.3.0-release-posix-dwarf-rt_v5-rev2.7z"
-MINGW_ARCHIVE_64="x86_64-6.3.0-release-posix-seh-rt_v5-rev2.7z"
+MINGW_ARCHIVE_32="i686-12.2.0-release-posix-dwarf-rt_v10-rev0.7z"
+MINGW_ARCHIVE_64="x86_64-12.2.0-release-posix-seh-rt_v10-rev0.7z"
 
 if isWindows; then
     case "${CI_JOB_NAME}" in
@@ -66,7 +48,6 @@ if isWindows; then
 
         curl -o mingw.7z "${MIRRORS_BASE}/${mingw_archive}"
         7z x -y mingw.7z > /dev/null
-        curl -o "${mingw_dir}/bin/gdborig.exe" "${MIRRORS_BASE}/2017-04-20-${bits}bit-gdborig.exe"
         ciCommandAddPath "$(pwd)/${mingw_dir}/bin"
     fi
 fi
diff --git a/src/ci/stage-build.py b/src/ci/stage-build.py
new file mode 100644
index 00000000000..c373edfcf46
--- /dev/null
+++ b/src/ci/stage-build.py
@@ -0,0 +1,663 @@
+#!/usr/bin/env python3
+# ignore-tidy-linelength
+
+# Compatible with Python 3.6+
+
+import contextlib
+import getpass
+import glob
+import logging
+import os
+import pprint
+import shutil
+import subprocess
+import sys
+import time
+import traceback
+import urllib.request
+from collections import OrderedDict
+from io import StringIO
+from pathlib import Path
+from typing import Callable, Dict, Iterable, List, Optional, Union
+
+PGO_HOST = os.environ["PGO_HOST"]
+
+LOGGER = logging.getLogger("stage-build")
+
+LLVM_PGO_CRATES = [
+    "syn-1.0.89",
+    "cargo-0.60.0",
+    "serde-1.0.136",
+    "ripgrep-13.0.0",
+    "regex-1.5.5",
+    "clap-3.1.6",
+    "hyper-0.14.18"
+]
+
+RUSTC_PGO_CRATES = [
+    "externs",
+    "ctfe-stress-5",
+    "cargo-0.60.0",
+    "token-stream-stress",
+    "match-stress",
+    "tuple-stress",
+    "diesel-1.4.8",
+    "bitmaps-3.1.0"
+]
+
+LLVM_BOLT_CRATES = LLVM_PGO_CRATES
+
+
+class Pipeline:
+    # Paths
+    def checkout_path(self) -> Path:
+        """
+        The root checkout, where the source is located.
+        """
+        raise NotImplementedError
+
+    def downloaded_llvm_dir(self) -> Path:
+        """
+        Directory where the host LLVM is located.
+        """
+        raise NotImplementedError
+
+    def build_root(self) -> Path:
+        """
+        The main directory where the build occurs.
+        """
+        raise NotImplementedError
+
+    def build_artifacts(self) -> Path:
+        return self.build_root() / "build" / PGO_HOST
+
+    def rustc_stage_0(self) -> Path:
+        return self.build_artifacts() / "stage0" / "bin" / "rustc"
+
+    def cargo_stage_0(self) -> Path:
+        return self.build_artifacts() / "stage0" / "bin" / "cargo"
+
+    def rustc_stage_2(self) -> Path:
+        return self.build_artifacts() / "stage2" / "bin" / "rustc"
+
+    def opt_artifacts(self) -> Path:
+        raise NotImplementedError
+
+    def llvm_profile_dir_root(self) -> Path:
+        return self.opt_artifacts() / "llvm-pgo"
+
+    def llvm_profile_merged_file(self) -> Path:
+        return self.opt_artifacts() / "llvm-pgo.profdata"
+
+    def rustc_perf_dir(self) -> Path:
+        return self.opt_artifacts() / "rustc-perf"
+
+    def build_rustc_perf(self):
+        raise NotImplementedError()
+
+    def rustc_profile_dir_root(self) -> Path:
+        return self.opt_artifacts() / "rustc-pgo"
+
+    def rustc_profile_merged_file(self) -> Path:
+        return self.opt_artifacts() / "rustc-pgo.profdata"
+
+    def rustc_profile_template_path(self) -> Path:
+        """
+        The profile data is written into a single filepath that is being repeatedly merged when each
+        rustc invocation ends. Empirically, this can result in some profiling data being lost. That's
+        why we override the profile path to include the PID. This will produce many more profiling
+        files, but the resulting profile will produce a slightly faster rustc binary.
+        """
+        return self.rustc_profile_dir_root() / "default_%m_%p.profraw"
+
+    def supports_bolt(self) -> bool:
+        raise NotImplementedError
+
+    def llvm_bolt_profile_merged_file(self) -> Path:
+        return self.opt_artifacts() / "bolt.profdata"
+
+
+class LinuxPipeline(Pipeline):
+    def checkout_path(self) -> Path:
+        return Path("/checkout")
+
+    def downloaded_llvm_dir(self) -> Path:
+        return Path("/rustroot")
+
+    def build_root(self) -> Path:
+        return self.checkout_path() / "obj"
+
+    def opt_artifacts(self) -> Path:
+        return Path("/tmp/tmp-multistage/opt-artifacts")
+
+    def build_rustc_perf(self):
+        # /tmp/rustc-perf comes from the Dockerfile
+        shutil.copytree("/tmp/rustc-perf", self.rustc_perf_dir())
+        cmd(["chown", "-R", f"{getpass.getuser()}:", self.rustc_perf_dir()])
+
+        with change_cwd(self.rustc_perf_dir()):
+            cmd([self.cargo_stage_0(), "build", "-p", "collector"], env=dict(
+                RUSTC=str(self.rustc_stage_0()),
+                RUSTC_BOOTSTRAP="1"
+            ))
+
+    def supports_bolt(self) -> bool:
+        return True
+
+
+class WindowsPipeline(Pipeline):
+    def __init__(self):
+        self.checkout_dir = Path(os.getcwd())
+
+    def checkout_path(self) -> Path:
+        return self.checkout_dir
+
+    def downloaded_llvm_dir(self) -> Path:
+        return self.checkout_path() / "citools" / "clang-rust"
+
+    def build_root(self) -> Path:
+        return self.checkout_path()
+
+    def opt_artifacts(self) -> Path:
+        return self.checkout_path() / "opt-artifacts"
+
+    def rustc_stage_0(self) -> Path:
+        return super().rustc_stage_0().with_suffix(".exe")
+
+    def cargo_stage_0(self) -> Path:
+        return super().cargo_stage_0().with_suffix(".exe")
+
+    def rustc_stage_2(self) -> Path:
+        return super().rustc_stage_2().with_suffix(".exe")
+
+    def build_rustc_perf(self):
+        # rustc-perf version from 2022-07-22
+        perf_commit = "3c253134664fdcba862c539d37f0de18557a9a4c"
+        rustc_perf_zip_path = self.opt_artifacts() / "perf.zip"
+
+        def download_rustc_perf():
+            download_file(
+                f"https://github.com/rust-lang/rustc-perf/archive/{perf_commit}.zip",
+                rustc_perf_zip_path
+            )
+            with change_cwd(self.opt_artifacts()):
+                unpack_archive(rustc_perf_zip_path)
+                move_path(Path(f"rustc-perf-{perf_commit}"), self.rustc_perf_dir())
+                delete_file(rustc_perf_zip_path)
+
+        retry_action(download_rustc_perf, "Download rustc-perf")
+
+        with change_cwd(self.rustc_perf_dir()):
+            cmd([self.cargo_stage_0(), "build", "-p", "collector"], env=dict(
+                RUSTC=str(self.rustc_stage_0()),
+                RUSTC_BOOTSTRAP="1"
+            ))
+
+    def rustc_profile_template_path(self) -> Path:
+        """
+        On Windows, we don't have enough space to use separate files for each rustc invocation.
+        Therefore, we use a single file for the generated profiles.
+        """
+        return self.rustc_profile_dir_root() / "default_%m.profraw"
+
+    def supports_bolt(self) -> bool:
+        return False
+
+
+class Timer:
+    def __init__(self):
+        # We want this dictionary to be ordered by insertion.
+        # We use `OrderedDict` for compatibility with older Python versions.
+        self.stages = OrderedDict()
+
+    @contextlib.contextmanager
+    def stage(self, name: str):
+        assert name not in self.stages
+
+        start = time.time()
+        exc = None
+        try:
+            LOGGER.info(f"Stage `{name}` starts")
+            yield
+        except BaseException as exception:
+            exc = exception
+            raise
+        finally:
+            end = time.time()
+            duration = end - start
+            self.stages[name] = duration
+            if exc is None:
+                LOGGER.info(f"Stage `{name}` ended: OK ({duration:.2f}s)")
+            else:
+                LOGGER.info(f"Stage `{name}` ended: FAIL ({duration:.2f}s)")
+
+    def print_stats(self):
+        total_duration = sum(self.stages.values())
+
+        # 57 is the width of the whole table
+        divider = "-" * 57
+
+        with StringIO() as output:
+            print(divider, file=output)
+            for (name, duration) in self.stages.items():
+                pct = (duration / total_duration) * 100
+                name_str = f"{name}:"
+                print(f"{name_str:<34} {duration:>12.2f}s ({pct:>5.2f}%)", file=output)
+
+            total_duration_label = "Total duration:"
+            print(f"{total_duration_label:<34} {total_duration:>12.2f}s", file=output)
+            print(divider, file=output, end="")
+            LOGGER.info(f"Timer results\n{output.getvalue()}")
+
+
+@contextlib.contextmanager
+def change_cwd(dir: Path):
+    """
+    Temporarily change working directory to `dir`.
+    """
+    cwd = os.getcwd()
+    LOGGER.debug(f"Changing working dir from `{cwd}` to `{dir}`")
+    os.chdir(dir)
+    try:
+        yield
+    finally:
+        LOGGER.debug(f"Reverting working dir to `{cwd}`")
+        os.chdir(cwd)
+
+
+def move_path(src: Path, dst: Path):
+    LOGGER.info(f"Moving `{src}` to `{dst}`")
+    shutil.move(src, dst)
+
+
+def delete_file(path: Path):
+    LOGGER.info(f"Deleting file `{path}`")
+    os.unlink(path)
+
+
+def delete_directory(path: Path):
+    LOGGER.info(f"Deleting directory `{path}`")
+    shutil.rmtree(path)
+
+
+def unpack_archive(archive: Path):
+    LOGGER.info(f"Unpacking archive `{archive}`")
+    shutil.unpack_archive(archive)
+
+
+def download_file(src: str, target: Path):
+    LOGGER.info(f"Downloading `{src}` into `{target}`")
+    urllib.request.urlretrieve(src, str(target))
+
+
+def retry_action(action, name: str, max_fails: int = 5):
+    LOGGER.info(f"Attempting to perform action `{name}` with retry")
+    for iteration in range(max_fails):
+        LOGGER.info(f"Attempt {iteration + 1}/{max_fails}")
+        try:
+            action()
+            return
+        except:
+            LOGGER.error(f"Action `{name}` has failed\n{traceback.format_exc()}")
+
+    raise Exception(f"Action `{name}` has failed after {max_fails} attempts")
+
+
+def cmd(
+        args: List[Union[str, Path]],
+        env: Optional[Dict[str, str]] = None,
+        output_path: Optional[Path] = None
+):
+    args = [str(arg) for arg in args]
+
+    environment = os.environ.copy()
+
+    cmd_str = ""
+    if env is not None:
+        environment.update(env)
+        cmd_str += " ".join(f"{k}={v}" for (k, v) in (env or {}).items())
+        cmd_str += " "
+    cmd_str += " ".join(args)
+    if output_path is not None:
+        cmd_str += f" > {output_path}"
+    LOGGER.info(f"Executing `{cmd_str}`")
+
+    if output_path is not None:
+        with open(output_path, "w") as f:
+            return subprocess.run(
+                args,
+                env=environment,
+                check=True,
+                stdout=f
+            )
+    return subprocess.run(args, env=environment, check=True)
+
+
+def run_compiler_benchmarks(
+        pipeline: Pipeline,
+        profiles: List[str],
+        scenarios: List[str],
+        crates: List[str],
+        env: Optional[Dict[str, str]] = None
+):
+    env = env if env is not None else {}
+
+    # Compile libcore, both in opt-level=0 and opt-level=3
+    with change_cwd(pipeline.build_root()):
+        cmd([
+            pipeline.rustc_stage_2(),
+            "--edition", "2021",
+            "--crate-type", "lib",
+            str(pipeline.checkout_path() / "library/core/src/lib.rs"),
+            "--out-dir", pipeline.opt_artifacts()
+        ], env=dict(RUSTC_BOOTSTRAP="1", **env))
+
+        cmd([
+            pipeline.rustc_stage_2(),
+            "--edition", "2021",
+            "--crate-type", "lib",
+            "-Copt-level=3",
+            str(pipeline.checkout_path() / "library/core/src/lib.rs"),
+            "--out-dir", pipeline.opt_artifacts()
+        ], env=dict(RUSTC_BOOTSTRAP="1", **env))
+
+    # Run rustc-perf benchmarks
+    # Benchmark using profile_local with eprintln, which essentially just means
+    # don't actually benchmark -- just make sure we run rustc a bunch of times.
+    with change_cwd(pipeline.rustc_perf_dir()):
+        cmd([
+            pipeline.cargo_stage_0(),
+            "run",
+            "-p", "collector", "--bin", "collector", "--",
+            "profile_local", "eprintln",
+            pipeline.rustc_stage_2(),
+            "--id", "Test",
+            "--cargo", pipeline.cargo_stage_0(),
+            "--profiles", ",".join(profiles),
+            "--scenarios", ",".join(scenarios),
+            "--include", ",".join(crates)
+        ], env=dict(
+            RUST_LOG="collector=debug",
+            RUSTC=str(pipeline.rustc_stage_0()),
+            RUSTC_BOOTSTRAP="1",
+            **env
+        ))
+
+
+# https://stackoverflow.com/a/31631711/1107768
+def format_bytes(size: int) -> str:
+    """Return the given bytes as a human friendly KiB, MiB or GiB string."""
+    KB = 1024
+    MB = KB ** 2  # 1,048,576
+    GB = KB ** 3  # 1,073,741,824
+    TB = KB ** 4  # 1,099,511,627,776
+
+    if size < KB:
+        return f"{size} B"
+    elif KB <= size < MB:
+        return f"{size / KB:.2f} KiB"
+    elif MB <= size < GB:
+        return f"{size / MB:.2f} MiB"
+    elif GB <= size < TB:
+        return f"{size / GB:.2f} GiB"
+    else:
+        return str(size)
+
+
+# https://stackoverflow.com/a/63307131/1107768
+def count_files(path: Path) -> int:
+    return sum(1 for p in path.rglob("*") if p.is_file())
+
+
+def count_files_with_prefix(path: Path) -> int:
+    return sum(1 for p in glob.glob(f"{path}*") if Path(p).is_file())
+
+
+# https://stackoverflow.com/a/55659577/1107768
+def get_path_size(path: Path) -> int:
+    if path.is_dir():
+        return sum(p.stat().st_size for p in path.rglob("*"))
+    return path.stat().st_size
+
+
+def get_path_prefix_size(path: Path) -> int:
+    """
+    Get size of all files beginning with the prefix `path`.
+    Alternative to shell `du -sh <path>*`.
+    """
+    return sum(Path(p).stat().st_size for p in glob.glob(f"{path}*"))
+
+
+def get_files(directory: Path, filter: Optional[Callable[[Path], bool]] = None) -> Iterable[Path]:
+    for file in os.listdir(directory):
+        path = directory / file
+        if filter is None or filter(path):
+            yield path
+
+
+def build_rustc(
+        pipeline: Pipeline,
+        args: List[str],
+        env: Optional[Dict[str, str]] = None
+):
+    arguments = [
+                    sys.executable,
+                    pipeline.checkout_path() / "x.py",
+                    "build",
+                    "--target", PGO_HOST,
+                    "--host", PGO_HOST,
+                    "--stage", "2",
+                    "library/std"
+                ] + args
+    cmd(arguments, env=env)
+
+
+def create_pipeline() -> Pipeline:
+    if sys.platform == "linux":
+        return LinuxPipeline()
+    elif sys.platform in ("cygwin", "win32"):
+        return WindowsPipeline()
+    else:
+        raise Exception(f"Optimized build is not supported for platform {sys.platform}")
+
+
+def gather_llvm_profiles(pipeline: Pipeline):
+    LOGGER.info("Running benchmarks with PGO instrumented LLVM")
+    run_compiler_benchmarks(
+        pipeline,
+        profiles=["Debug", "Opt"],
+        scenarios=["Full"],
+        crates=LLVM_PGO_CRATES
+    )
+
+    profile_path = pipeline.llvm_profile_merged_file()
+    LOGGER.info(f"Merging LLVM PGO profiles to {profile_path}")
+    cmd([
+        pipeline.downloaded_llvm_dir() / "bin" / "llvm-profdata",
+        "merge",
+        "-o", profile_path,
+        pipeline.llvm_profile_dir_root()
+    ])
+
+    LOGGER.info("LLVM PGO statistics")
+    LOGGER.info(f"{profile_path}: {format_bytes(get_path_size(profile_path))}")
+    LOGGER.info(
+        f"{pipeline.llvm_profile_dir_root()}: {format_bytes(get_path_size(pipeline.llvm_profile_dir_root()))}")
+    LOGGER.info(f"Profile file count: {count_files(pipeline.llvm_profile_dir_root())}")
+
+    # We don't need the individual .profraw files now that they have been merged
+    # into a final .profdata
+    delete_directory(pipeline.llvm_profile_dir_root())
+
+
+def gather_rustc_profiles(pipeline: Pipeline):
+    LOGGER.info("Running benchmarks with PGO instrumented rustc")
+
+    # Here we're profiling the `rustc` frontend, so we also include `Check`.
+    # The benchmark set includes various stress tests that put the frontend under pressure.
+    run_compiler_benchmarks(
+        pipeline,
+        profiles=["Check", "Debug", "Opt"],
+        scenarios=["All"],
+        crates=RUSTC_PGO_CRATES,
+        env=dict(
+            LLVM_PROFILE_FILE=str(pipeline.rustc_profile_template_path())
+        )
+    )
+
+    profile_path = pipeline.rustc_profile_merged_file()
+    LOGGER.info(f"Merging Rustc PGO profiles to {profile_path}")
+    cmd([
+        pipeline.build_artifacts() / "llvm" / "bin" / "llvm-profdata",
+        "merge",
+        "-o", profile_path,
+        pipeline.rustc_profile_dir_root()
+    ])
+
+    LOGGER.info("Rustc PGO statistics")
+    LOGGER.info(f"{profile_path}: {format_bytes(get_path_size(profile_path))}")
+    LOGGER.info(
+        f"{pipeline.rustc_profile_dir_root()}: {format_bytes(get_path_size(pipeline.rustc_profile_dir_root()))}")
+    LOGGER.info(f"Profile file count: {count_files(pipeline.rustc_profile_dir_root())}")
+
+    # We don't need the individual .profraw files now that they have been merged
+    # into a final .profdata
+    delete_directory(pipeline.rustc_profile_dir_root())
+
+
+def gather_llvm_bolt_profiles(pipeline: Pipeline):
+    LOGGER.info("Running benchmarks with BOLT instrumented LLVM")
+    run_compiler_benchmarks(
+        pipeline,
+        profiles=["Check", "Debug", "Opt"],
+        scenarios=["Full"],
+        crates=LLVM_BOLT_CRATES
+    )
+
+    merged_profile_path = pipeline.llvm_bolt_profile_merged_file()
+    profile_files_path = Path("/tmp/prof.fdata")
+    LOGGER.info(f"Merging LLVM BOLT profiles to {merged_profile_path}")
+
+    profile_files = sorted(glob.glob(f"{profile_files_path}*"))
+    cmd([
+        "merge-fdata",
+        *profile_files,
+    ], output_path=merged_profile_path)
+
+    LOGGER.info("LLVM BOLT statistics")
+    LOGGER.info(f"{merged_profile_path}: {format_bytes(get_path_size(merged_profile_path))}")
+    LOGGER.info(
+        f"{profile_files_path}: {format_bytes(get_path_prefix_size(profile_files_path))}")
+    LOGGER.info(f"Profile file count: {count_files_with_prefix(profile_files_path)}")
+
+
+def clear_llvm_files(pipeline: Pipeline):
+    """
+    Rustbuild currently doesn't support rebuilding LLVM when PGO options
+    change (or any other llvm-related options); so just clear out the relevant
+    directories ourselves.
+    """
+    LOGGER.info("Clearing LLVM build files")
+    delete_directory(pipeline.build_artifacts() / "llvm")
+    delete_directory(pipeline.build_artifacts() / "lld")
+
+
+def print_binary_sizes(pipeline: Pipeline):
+    bin_dir = pipeline.build_artifacts() / "stage2" / "bin"
+    binaries = get_files(bin_dir)
+
+    lib_dir = pipeline.build_artifacts() / "stage2" / "lib"
+    libraries = get_files(lib_dir, lambda p: p.suffix == ".so")
+
+    paths = sorted(binaries) + sorted(libraries)
+    with StringIO() as output:
+        for path in paths:
+            path_str = f"{path.name}:"
+            print(f"{path_str:<30}{format_bytes(path.stat().st_size):>14}", file=output)
+        LOGGER.info(f"Rustc binary size\n{output.getvalue()}")
+
+
+def execute_build_pipeline(timer: Timer, pipeline: Pipeline, final_build_args: List[str]):
+    # Clear and prepare tmp directory
+    shutil.rmtree(pipeline.opt_artifacts(), ignore_errors=True)
+    os.makedirs(pipeline.opt_artifacts(), exist_ok=True)
+
+    pipeline.build_rustc_perf()
+
+    # Stage 1: Build rustc + PGO instrumented LLVM
+    with timer.stage("Build rustc (LLVM PGO)"):
+        build_rustc(pipeline, args=[
+            "--llvm-profile-generate"
+        ], env=dict(
+            LLVM_PROFILE_DIR=str(pipeline.llvm_profile_dir_root() / "prof-%p")
+        ))
+
+    with timer.stage("Gather profiles (LLVM PGO)"):
+        gather_llvm_profiles(pipeline)
+
+    clear_llvm_files(pipeline)
+    final_build_args += [
+        "--llvm-profile-use",
+        pipeline.llvm_profile_merged_file()
+    ]
+
+    # Stage 2: Build PGO instrumented rustc + LLVM
+    with timer.stage("Build rustc (rustc PGO)"):
+        build_rustc(pipeline, args=[
+            "--rust-profile-generate",
+            pipeline.rustc_profile_dir_root()
+        ])
+
+    with timer.stage("Gather profiles (rustc PGO)"):
+        gather_rustc_profiles(pipeline)
+
+    clear_llvm_files(pipeline)
+    final_build_args += [
+        "--rust-profile-use",
+        pipeline.rustc_profile_merged_file()
+    ]
+
+    # Stage 3: Build rustc + BOLT instrumented LLVM
+    if pipeline.supports_bolt():
+        with timer.stage("Build rustc (LLVM BOLT)"):
+            build_rustc(pipeline, args=[
+                "--llvm-profile-use",
+                pipeline.llvm_profile_merged_file(),
+                "--llvm-bolt-profile-generate",
+            ])
+        with timer.stage("Gather profiles (LLVM BOLT)"):
+            gather_llvm_bolt_profiles(pipeline)
+
+        clear_llvm_files(pipeline)
+        final_build_args += [
+            "--llvm-bolt-profile-use",
+            pipeline.llvm_bolt_profile_merged_file()
+        ]
+
+    # Stage 4: Build PGO optimized rustc + PGO/BOLT optimized LLVM
+    with timer.stage("Final build"):
+        cmd(final_build_args)
+
+
+if __name__ == "__main__":
+    logging.basicConfig(
+        level=logging.DEBUG,
+        format="%(name)s %(levelname)-4s: %(message)s",
+    )
+
+    LOGGER.info(f"Running multi-stage build using Python {sys.version}")
+    LOGGER.info(f"Environment values\n{pprint.pformat(dict(os.environ), indent=2)}")
+
+    build_args = sys.argv[1:]
+
+    timer = Timer()
+    pipeline = create_pipeline()
+    try:
+        execute_build_pipeline(timer, pipeline, build_args)
+    except BaseException as e:
+        LOGGER.error("The multi-stage build has failed")
+        raise e
+    finally:
+        timer.print_stats()
+
+    print_binary_sizes(pipeline)
diff --git a/src/doc/unstable-book/src/compiler-flags/tiny-const-eval-limit.md b/src/doc/unstable-book/src/compiler-flags/tiny-const-eval-limit.md
new file mode 100644
index 00000000000..51c5fd69c63
--- /dev/null
+++ b/src/doc/unstable-book/src/compiler-flags/tiny-const-eval-limit.md
@@ -0,0 +1,6 @@
+# `tiny-const-eval-limit`
+
+--------------------
+
+The `-Ztiny-const-eval-limit` compiler flag sets a tiny, non-configurable limit for const eval.
+This flag should only be used by const eval tests in the rustc test suite.
diff --git a/src/etc/pre-push.sh b/src/etc/pre-push.sh
index 7a846d44ad6..ff17931115c 100755
--- a/src/etc/pre-push.sh
+++ b/src/etc/pre-push.sh
@@ -14,4 +14,4 @@ ROOT_DIR="$(git rev-parse --show-toplevel)"
 echo "Running pre-push script $ROOT_DIR/x test tidy"
 
 cd "$ROOT_DIR"
-./x test tidy
+CARGOFLAGS="--locked" ./x test tidy
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index da300b89a4e..6592692d8b2 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -251,7 +251,7 @@ pub(crate) fn build_external_trait(cx: &mut DocContext<'_>, did: DefId) -> clean
 }
 
 fn build_external_function<'tcx>(cx: &mut DocContext<'tcx>, did: DefId) -> Box<clean::Function> {
-    let sig = cx.tcx.fn_sig(did);
+    let sig = cx.tcx.fn_sig(did).subst_identity();
 
     let late_bound_regions = sig.bound_vars().into_iter().filter_map(|var| match var {
         ty::BoundVariableKind::Region(ty::BrNamed(_, name)) if name != kw::UnderscoreLifetime => {
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 34a7068e5da..e2ced191a00 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -15,7 +15,7 @@ use rustc_attr as attr;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet, IndexEntry};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
-use rustc_hir::def_id::{DefId, DefIdMap, DefIdSet, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
 use rustc_hir::PredicateOrigin;
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
@@ -116,7 +116,8 @@ pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<
         }
     });
 
-    Item::from_hir_id_and_parts(doc.id, Some(doc.name), ModuleItem(Module { items, span }), cx)
+    let kind = ModuleItem(Module { items, span });
+    Item::from_def_id_and_parts(doc.def_id.to_def_id(), Some(doc.name), kind, cx)
 }
 
 fn clean_generic_bound<'tcx>(
@@ -382,13 +383,10 @@ fn clean_middle_term<'tcx>(
 fn clean_hir_term<'tcx>(term: &hir::Term<'tcx>, cx: &mut DocContext<'tcx>) -> Term {
     match term {
         hir::Term::Ty(ty) => Term::Type(clean_ty(ty, cx)),
-        hir::Term::Const(c) => {
-            let def_id = cx.tcx.hir().local_def_id(c.hir_id);
-            Term::Constant(clean_middle_const(
-                ty::Binder::dummy(ty::Const::from_anon_const(cx.tcx, def_id)),
-                cx,
-            ))
-        }
+        hir::Term::Const(c) => Term::Constant(clean_middle_const(
+            ty::Binder::dummy(ty::Const::from_anon_const(cx.tcx, c.def_id)),
+            cx,
+        )),
     }
 }
 
@@ -523,12 +521,11 @@ fn clean_generic_param<'tcx>(
     generics: Option<&hir::Generics<'tcx>>,
     param: &hir::GenericParam<'tcx>,
 ) -> GenericParamDef {
-    let did = cx.tcx.hir().local_def_id(param.hir_id);
     let (name, kind) = match param.kind {
         hir::GenericParamKind::Lifetime { .. } => {
             let outlives = if let Some(generics) = generics {
                 generics
-                    .outlives_for_param(did)
+                    .outlives_for_param(param.def_id)
                     .filter(|bp| !bp.in_where_clause)
                     .flat_map(|bp| bp.bounds)
                     .map(|bound| match bound {
@@ -544,7 +541,7 @@ fn clean_generic_param<'tcx>(
         hir::GenericParamKind::Type { ref default, synthetic } => {
             let bounds = if let Some(generics) = generics {
                 generics
-                    .bounds_for_param(did)
+                    .bounds_for_param(param.def_id)
                     .filter(|bp| bp.origin != PredicateOrigin::WhereClause)
                     .flat_map(|bp| bp.bounds)
                     .filter_map(|x| clean_generic_bound(x, cx))
@@ -555,7 +552,7 @@ fn clean_generic_param<'tcx>(
             (
                 param.name.ident().name,
                 GenericParamDefKind::Type {
-                    did: did.to_def_id(),
+                    did: param.def_id.to_def_id(),
                     bounds,
                     default: default.map(|t| clean_ty(t, cx)).map(Box::new),
                     synthetic,
@@ -565,12 +562,10 @@ fn clean_generic_param<'tcx>(
         hir::GenericParamKind::Const { ty, default } => (
             param.name.ident().name,
             GenericParamDefKind::Const {
-                did: did.to_def_id(),
+                did: param.def_id.to_def_id(),
                 ty: Box::new(clean_ty(ty, cx)),
-                default: default.map(|ct| {
-                    let def_id = cx.tcx.hir().local_def_id(ct.hir_id);
-                    Box::new(ty::Const::from_anon_const(cx.tcx, def_id).to_string())
-                }),
+                default: default
+                    .map(|ct| Box::new(ty::Const::from_anon_const(cx.tcx, ct.def_id).to_string())),
             },
         ),
     };
@@ -1230,7 +1225,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
             }
         }
         ty::AssocKind::Fn => {
-            let sig = tcx.fn_sig(assoc_item.def_id);
+            let sig = tcx.fn_sig(assoc_item.def_id).subst_identity();
 
             let late_bound_regions = sig.bound_vars().into_iter().filter_map(|var| match var {
                 ty::BoundVariableKind::Region(ty::BrNamed(_, name))
@@ -1547,18 +1542,16 @@ fn maybe_expand_private_type_alias<'tcx>(
                     _ => None,
                 });
                 if let Some(lt) = lifetime {
-                    let lt_def_id = cx.tcx.hir().local_def_id(param.hir_id);
                     let cleaned = if !lt.is_anonymous() {
                         clean_lifetime(lt, cx)
                     } else {
                         Lifetime::elided()
                     };
-                    substs.insert(lt_def_id.to_def_id(), SubstParam::Lifetime(cleaned));
+                    substs.insert(param.def_id.to_def_id(), SubstParam::Lifetime(cleaned));
                 }
                 indices.lifetimes += 1;
             }
             hir::GenericParamKind::Type { ref default, .. } => {
-                let ty_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
                 let mut j = 0;
                 let type_ = generic_args.args.iter().find_map(|arg| match arg {
                     hir::GenericArg::Type(ty) => {
@@ -1571,17 +1564,14 @@ fn maybe_expand_private_type_alias<'tcx>(
                     _ => None,
                 });
                 if let Some(ty) = type_ {
-                    substs.insert(ty_param_def_id.to_def_id(), SubstParam::Type(clean_ty(ty, cx)));
+                    substs.insert(param.def_id.to_def_id(), SubstParam::Type(clean_ty(ty, cx)));
                 } else if let Some(default) = *default {
-                    substs.insert(
-                        ty_param_def_id.to_def_id(),
-                        SubstParam::Type(clean_ty(default, cx)),
-                    );
+                    substs
+                        .insert(param.def_id.to_def_id(), SubstParam::Type(clean_ty(default, cx)));
                 }
                 indices.types += 1;
             }
             hir::GenericParamKind::Const { .. } => {
-                let const_param_def_id = cx.tcx.hir().local_def_id(param.hir_id);
                 let mut j = 0;
                 let const_ = generic_args.args.iter().find_map(|arg| match arg {
                     hir::GenericArg::Const(ct) => {
@@ -1595,7 +1585,7 @@ fn maybe_expand_private_type_alias<'tcx>(
                 });
                 if let Some(ct) = const_ {
                     substs.insert(
-                        const_param_def_id.to_def_id(),
+                        param.def_id.to_def_id(),
                         SubstParam::Constant(clean_const(ct, cx)),
                     );
                 }
@@ -1623,7 +1613,6 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
             let length = match length {
                 hir::ArrayLen::Infer(_, _) => "_".to_string(),
                 hir::ArrayLen::Body(anon_const) => {
-                    let def_id = cx.tcx.hir().local_def_id(anon_const.hir_id);
                     // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
                     // as we currently do not supply the parent generics to anonymous constants
                     // but do allow `ConstKind::Param`.
@@ -1631,8 +1620,8 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
                     // `const_eval_poly` tries to first substitute generic parameters which
                     // results in an ICE while manually constructing the constant and using `eval`
                     // does nothing for `ConstKind::Param`.
-                    let ct = ty::Const::from_anon_const(cx.tcx, def_id);
-                    let param_env = cx.tcx.param_env(def_id);
+                    let ct = ty::Const::from_anon_const(cx.tcx, anon_const.def_id);
+                    let param_env = cx.tcx.param_env(anon_const.def_id);
                     print_const(cx, ct.eval(cx.tcx, param_env))
                 }
             };
@@ -1854,6 +1843,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
         ty::Bound(..) => panic!("Bound"),
         ty::Placeholder(..) => panic!("Placeholder"),
         ty::GeneratorWitness(..) => panic!("GeneratorWitness"),
+        ty::GeneratorWitnessMIR(..) => panic!("GeneratorWitnessMIR"),
         ty::Infer(..) => panic!("Infer"),
         ty::Error(_) => rustc_errors::FatalError.raise(),
     }
@@ -1928,8 +1918,7 @@ fn clean_middle_opaque_bounds<'tcx>(
 }
 
 pub(crate) fn clean_field<'tcx>(field: &hir::FieldDef<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
-    let def_id = cx.tcx.hir().local_def_id(field.hir_id).to_def_id();
-    clean_field_with_def_id(def_id, field.ident.name, clean_ty(field.ty, cx), cx)
+    clean_field_with_def_id(field.def_id.to_def_id(), field.ident.name, clean_ty(field.ty, cx), cx)
 }
 
 pub(crate) fn clean_middle_field<'tcx>(field: &ty::FieldDef, cx: &mut DocContext<'tcx>) -> Item {
@@ -1979,10 +1968,8 @@ fn clean_variant_data<'tcx>(
     disr_expr: &Option<hir::AnonConst>,
     cx: &mut DocContext<'tcx>,
 ) -> Variant {
-    let discriminant = disr_expr.map(|disr| Discriminant {
-        expr: Some(disr.body),
-        value: cx.tcx.hir().local_def_id(disr.hir_id).to_def_id(),
-    });
+    let discriminant = disr_expr
+        .map(|disr| Discriminant { expr: Some(disr.body), value: disr.def_id.to_def_id() });
 
     let kind = match variant {
         hir::VariantData::Struct(..) => VariantKind::Struct(VariantStruct {
@@ -2067,12 +2054,12 @@ struct OneLevelVisitor<'hir> {
     map: rustc_middle::hir::map::Map<'hir>,
     item: Option<&'hir hir::Item<'hir>>,
     looking_for: Ident,
-    target_hir_id: hir::HirId,
+    target_def_id: LocalDefId,
 }
 
 impl<'hir> OneLevelVisitor<'hir> {
-    fn new(map: rustc_middle::hir::map::Map<'hir>, target_hir_id: hir::HirId) -> Self {
-        Self { map, item: None, looking_for: Ident::empty(), target_hir_id }
+    fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
+        Self { map, item: None, looking_for: Ident::empty(), target_def_id }
     }
 
     fn reset(&mut self, looking_for: Ident) {
@@ -2092,7 +2079,7 @@ impl<'hir> hir::intravisit::Visitor<'hir> for OneLevelVisitor<'hir> {
         if self.item.is_none()
             && item.ident == self.looking_for
             && matches!(item.kind, hir::ItemKind::Use(_, _))
-            || item.hir_id() == self.target_hir_id
+            || item.owner_id.def_id == self.target_def_id
         {
             self.item = Some(item);
         }
@@ -2106,15 +2093,17 @@ impl<'hir> hir::intravisit::Visitor<'hir> for OneLevelVisitor<'hir> {
 fn get_all_import_attributes<'hir>(
     mut item: &hir::Item<'hir>,
     tcx: TyCtxt<'hir>,
-    target_hir_id: hir::HirId,
+    target_def_id: LocalDefId,
     attributes: &mut Vec<ast::Attribute>,
 ) {
     let hir_map = tcx.hir();
-    let mut visitor = OneLevelVisitor::new(hir_map, target_hir_id);
+    let mut visitor = OneLevelVisitor::new(hir_map, target_def_id);
+    let mut visited = FxHashSet::default();
     // If the item is an import and has at least a path with two parts, we go into it.
     while let hir::ItemKind::Use(path, _) = item.kind &&
         path.segments.len() > 1 &&
-        let hir::def::Res::Def(_, def_id) = path.segments[path.segments.len() - 2].res
+        let hir::def::Res::Def(_, def_id) = path.segments[path.segments.len() - 2].res &&
+        visited.insert(def_id)
     {
         if let Some(hir::Node::Item(parent_item)) = hir_map.get_if_local(def_id) {
             // We add the attributes from this import into the list.
@@ -2138,7 +2127,7 @@ fn clean_maybe_renamed_item<'tcx>(
     cx: &mut DocContext<'tcx>,
     item: &hir::Item<'tcx>,
     renamed: Option<Symbol>,
-    import_id: Option<hir::HirId>,
+    import_id: Option<LocalDefId>,
 ) -> Vec<Item> {
     use hir::ItemKind;
 
@@ -2183,7 +2172,7 @@ fn clean_maybe_renamed_item<'tcx>(
                 generics: clean_generics(generics, cx),
                 fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
             }),
-            ItemKind::Impl(impl_) => return clean_impl(impl_, item.hir_id(), cx),
+            ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx),
             // proc macros can have a name set by attributes
             ItemKind::Fn(ref sig, generics, body_id) => {
                 clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
@@ -2218,10 +2207,10 @@ fn clean_maybe_renamed_item<'tcx>(
 
         let mut extra_attrs = Vec::new();
         if let Some(hir::Node::Item(use_node)) =
-            import_id.and_then(|hir_id| cx.tcx.hir().find(hir_id))
+            import_id.and_then(|def_id| cx.tcx.hir().find_by_def_id(def_id))
         {
             // We get all the various imports' attributes.
-            get_all_import_attributes(use_node, cx.tcx, item.hir_id(), &mut extra_attrs);
+            get_all_import_attributes(use_node, cx.tcx, item.owner_id.def_id, &mut extra_attrs);
         }
 
         if !extra_attrs.is_empty() {
@@ -2244,12 +2233,12 @@ fn clean_maybe_renamed_item<'tcx>(
 
 fn clean_variant<'tcx>(variant: &hir::Variant<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
     let kind = VariantItem(clean_variant_data(&variant.data, &variant.disr_expr, cx));
-    Item::from_hir_id_and_parts(variant.hir_id, Some(variant.ident.name), kind, cx)
+    Item::from_def_id_and_parts(variant.def_id.to_def_id(), Some(variant.ident.name), kind, cx)
 }
 
 fn clean_impl<'tcx>(
     impl_: &hir::Impl<'tcx>,
-    hir_id: hir::HirId,
+    def_id: LocalDefId,
     cx: &mut DocContext<'tcx>,
 ) -> Vec<Item> {
     let tcx = cx.tcx;
@@ -2260,7 +2249,6 @@ fn clean_impl<'tcx>(
         .iter()
         .map(|ii| clean_impl_item(tcx.hir().impl_item(ii.id), cx))
         .collect::<Vec<_>>();
-    let def_id = tcx.hir().local_def_id(hir_id);
 
     // If this impl block is an implementation of the Deref trait, then we
     // need to try inlining the target's inherent impl blocks as well.
@@ -2289,7 +2277,7 @@ fn clean_impl<'tcx>(
                 ImplKind::Normal
             },
         }));
-        Item::from_hir_id_and_parts(hir_id, None, kind, cx)
+        Item::from_def_id_and_parts(def_id.to_def_id(), None, kind, cx)
     };
     if let Some(type_alias) = type_alias {
         ret.push(make_item(trait_.clone(), type_alias, items.clone()));
@@ -2510,8 +2498,8 @@ fn clean_maybe_renamed_foreign_item<'tcx>(
             hir::ForeignItemKind::Type => ForeignTypeItem,
         };
 
-        Item::from_hir_id_and_parts(
-            item.hir_id(),
+        Item::from_def_id_and_parts(
+            item.owner_id.def_id.to_def_id(),
             Some(renamed.unwrap_or(item.ident.name)),
             kind,
             cx,
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index a020ccd53b8..85dd3881593 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -439,17 +439,6 @@ impl Item {
         self.attrs.doc_value()
     }
 
-    /// Convenience wrapper around [`Self::from_def_id_and_parts`] which converts
-    /// `hir_id` to a [`DefId`]
-    pub(crate) fn from_hir_id_and_parts(
-        hir_id: hir::HirId,
-        name: Option<Symbol>,
-        kind: ItemKind,
-        cx: &mut DocContext<'_>,
-    ) -> Item {
-        Item::from_def_id_and_parts(cx.tcx.hir().local_def_id(hir_id).to_def_id(), name, kind, cx)
-    }
-
     pub(crate) fn from_def_id_and_parts(
         def_id: DefId,
         name: Option<Symbol>,
@@ -665,7 +654,7 @@ impl Item {
             tcx: TyCtxt<'_>,
             asyncness: hir::IsAsync,
         ) -> hir::FnHeader {
-            let sig = tcx.fn_sig(def_id);
+            let sig = tcx.fn_sig(def_id).skip_binder();
             let constness =
                 if tcx.is_const_fn(def_id) && is_unstable_const_fn(tcx, def_id).is_none() {
                     hir::Constness::Const
@@ -677,7 +666,7 @@ impl Item {
         let header = match *self.kind {
             ItemKind::ForeignFunctionItem(_) => {
                 let def_id = self.item_id.as_def_id().unwrap();
-                let abi = tcx.fn_sig(def_id).abi();
+                let abi = tcx.fn_sig(def_id).skip_binder().abi();
                 hir::FnHeader {
                     unsafety: if abi == Abi::RustIntrinsic {
                         intrinsic_operation_unsafety(tcx, self.item_id.as_def_id().unwrap())
@@ -2416,10 +2405,7 @@ impl ConstantKind {
 
     pub(crate) fn is_literal(&self, tcx: TyCtxt<'_>) -> bool {
         match *self {
-            ConstantKind::TyConst { .. } => false,
-            ConstantKind::Extern { def_id } => def_id.as_local().map_or(false, |def_id| {
-                is_literal_expr(tcx, tcx.hir().local_def_id_to_hir_id(def_id))
-            }),
+            ConstantKind::TyConst { .. } | ConstantKind::Extern { .. } => false,
             ConstantKind::Local { body, .. } | ConstantKind::Anonymous { body } => {
                 is_literal_expr(tcx, body.hir_id)
             }
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index a12f764fa8e..ca3a70c7236 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -29,11 +29,6 @@ mod tests;
 pub(crate) fn krate(cx: &mut DocContext<'_>) -> Crate {
     let module = crate::visit_ast::RustdocVisitor::new(cx).visit();
 
-    for &cnum in cx.tcx.crates(()) {
-        // Analyze doc-reachability for extern items
-        crate::visit_lib::lib_embargo_visit_item(cx, cnum.as_def_id());
-    }
-
     // Clean the crate, translating the entire librustc_ast AST to one that is
     // understood by rustdoc.
     let mut module = clean_doc_module(&module, cx);
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 56b40d8c66b..2c514a0c826 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -509,7 +509,7 @@ impl Options {
                 // these values up both in `dataset` and in the storage API, so it needs to be able
                 // to convert the names back and forth.  Despite doing this kebab-case to
                 // StudlyCaps transformation automatically, the JS DOM API does not provide a
-                // mechanism for doing the just transformation on a string.  So we want to avoid
+                // mechanism for doing just the transformation on a string.  So we want to avoid
                 // the StudlyCaps representation in the `dataset` property.
                 //
                 // We solve this by replacing all the `-`s with `_`s.  We do that here, when we
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 10b606f425e..0ce43f7db8e 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -41,6 +41,7 @@ pub(crate) struct ResolverCaches {
     pub(crate) traits_in_scope: DefIdMap<Vec<TraitCandidate>>,
     pub(crate) all_trait_impls: Option<Vec<DefId>>,
     pub(crate) all_macro_rules: FxHashMap<Symbol, Res<NodeId>>,
+    pub(crate) extern_doc_reachable: DefIdSet,
 }
 
 pub(crate) struct DocContext<'tcx> {
@@ -363,6 +364,10 @@ pub(crate) fn run_global_ctxt(
         show_coverage,
     };
 
+    ctxt.cache
+        .effective_visibilities
+        .init(mem::take(&mut ctxt.resolver_caches.extern_doc_reachable));
+
     // Small hack to force the Sized trait to be present.
     //
     // Note that in case of `#![no_core]`, the trait is not available.
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index c1a652c75f4..37a1005cba1 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -2,10 +2,8 @@ use rustc_ast as ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{ColorConfig, ErrorGuaranteed, FatalError};
-use rustc_hir as hir;
-use rustc_hir::def_id::LOCAL_CRATE;
-use rustc_hir::intravisit;
-use rustc_hir::{HirId, CRATE_HIR_ID};
+use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::{self as hir, intravisit, CRATE_HIR_ID};
 use rustc_interface::interface;
 use rustc_middle::hir::map::Map;
 use rustc_middle::hir::nested_filter;
@@ -140,7 +138,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
                     };
                     hir_collector.visit_testable(
                         "".to_string(),
-                        CRATE_HIR_ID,
+                        CRATE_DEF_ID,
                         tcx.hir().span(CRATE_HIR_ID),
                         |this| tcx.hir().walk_toplevel_module(this),
                     );
@@ -1214,11 +1212,11 @@ impl<'a, 'hir, 'tcx> HirCollector<'a, 'hir, 'tcx> {
     fn visit_testable<F: FnOnce(&mut Self)>(
         &mut self,
         name: String,
-        hir_id: HirId,
+        def_id: LocalDefId,
         sp: Span,
         nested: F,
     ) {
-        let ast_attrs = self.tcx.hir().attrs(hir_id);
+        let ast_attrs = self.tcx.hir().attrs(self.tcx.hir().local_def_id_to_hir_id(def_id));
         if let Some(ref cfg) = ast_attrs.cfg(self.tcx, &FxHashSet::default()) {
             if !cfg.matches(&self.sess.parse_sess, Some(self.tcx.features())) {
                 return;
@@ -1247,7 +1245,7 @@ impl<'a, 'hir, 'tcx> HirCollector<'a, 'hir, 'tcx> {
                 self.collector.enable_per_target_ignores,
                 Some(&crate::html::markdown::ExtraInfo::new(
                     self.tcx,
-                    hir_id,
+                    def_id.to_def_id(),
                     span_of_attrs(&attrs).unwrap_or(sp),
                 )),
             );
@@ -1276,37 +1274,37 @@ impl<'a, 'hir, 'tcx> intravisit::Visitor<'hir> for HirCollector<'a, 'hir, 'tcx>
             _ => item.ident.to_string(),
         };
 
-        self.visit_testable(name, item.hir_id(), item.span, |this| {
+        self.visit_testable(name, item.owner_id.def_id, item.span, |this| {
             intravisit::walk_item(this, item);
         });
     }
 
     fn visit_trait_item(&mut self, item: &'hir hir::TraitItem<'_>) {
-        self.visit_testable(item.ident.to_string(), item.hir_id(), item.span, |this| {
+        self.visit_testable(item.ident.to_string(), item.owner_id.def_id, item.span, |this| {
             intravisit::walk_trait_item(this, item);
         });
     }
 
     fn visit_impl_item(&mut self, item: &'hir hir::ImplItem<'_>) {
-        self.visit_testable(item.ident.to_string(), item.hir_id(), item.span, |this| {
+        self.visit_testable(item.ident.to_string(), item.owner_id.def_id, item.span, |this| {
             intravisit::walk_impl_item(this, item);
         });
     }
 
     fn visit_foreign_item(&mut self, item: &'hir hir::ForeignItem<'_>) {
-        self.visit_testable(item.ident.to_string(), item.hir_id(), item.span, |this| {
+        self.visit_testable(item.ident.to_string(), item.owner_id.def_id, item.span, |this| {
             intravisit::walk_foreign_item(this, item);
         });
     }
 
     fn visit_variant(&mut self, v: &'hir hir::Variant<'_>) {
-        self.visit_testable(v.ident.to_string(), v.hir_id, v.span, |this| {
+        self.visit_testable(v.ident.to_string(), v.def_id, v.span, |this| {
             intravisit::walk_variant(this, v);
         });
     }
 
     fn visit_field_def(&mut self, f: &'hir hir::FieldDef<'_>) {
-        self.visit_testable(f.ident.to_string(), f.hir_id, f.span, |this| {
+        self.visit_testable(f.ident.to_string(), f.def_id, f.span, |this| {
             intravisit::walk_field_def(this, f);
         });
     }
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index d3dc4065dfc..33404a76835 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -1064,14 +1064,8 @@ fn fmt_type<'cx>(
                     fmt_type(ty, f, use_absolute, cx)?;
                     write!(f, ")")
                 }
-                clean::Generic(..) => {
-                    primitive_link(
-                        f,
-                        PrimitiveType::Reference,
-                        &format!("{}{}{}", amp, lt, m),
-                        cx,
-                    )?;
-                    fmt_type(ty, f, use_absolute, cx)
+                clean::Generic(name) => {
+                    primitive_link(f, PrimitiveType::Reference, &format!("{amp}{lt}{m}{name}"), cx)
                 }
                 _ => {
                     write!(f, "{}{}{}", amp, lt, m)?;
diff --git a/src/librustdoc/html/length_limit.rs b/src/librustdoc/html/length_limit.rs
index bbdc91c8d2e..4c8db2c6784 100644
--- a/src/librustdoc/html/length_limit.rs
+++ b/src/librustdoc/html/length_limit.rs
@@ -61,14 +61,14 @@ impl HtmlWithLimit {
     /// and returns [`ControlFlow::Break`].
     pub(super) fn push(&mut self, text: &str) -> ControlFlow<(), ()> {
         if self.len + text.len() > self.limit {
-            return ControlFlow::BREAK;
+            return ControlFlow::Break(());
         }
 
         self.flush_queue();
         write!(self.buf, "{}", Escape(text)).unwrap();
         self.len += text.len();
 
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     /// Open an HTML tag.
diff --git a/src/librustdoc/html/length_limit/tests.rs b/src/librustdoc/html/length_limit/tests.rs
index 2d02b8a16da..2185c034890 100644
--- a/src/librustdoc/html/length_limit/tests.rs
+++ b/src/librustdoc/html/length_limit/tests.rs
@@ -83,7 +83,7 @@ fn past_the_limit() {
         buf.push("word#")?;
         buf.push(&n.to_string())?;
         buf.close_tag();
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     });
     buf.close_tag();
     assert_eq!(
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 4ff67fe1551..00e3f859bfc 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -27,7 +27,6 @@
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def_id::DefId;
-use rustc_hir::HirId;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::edition::Edition;
 use rustc_span::{Span, Symbol};
@@ -296,7 +295,9 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
             let channel = if test.contains("#![feature(") { "&amp;version=nightly" } else { "" };
 
             // These characters don't need to be escaped in a URI.
-            // FIXME: use a library function for percent encoding.
+            // See https://url.spec.whatwg.org/#query-percent-encode-set
+            // and https://url.spec.whatwg.org/#urlencoded-parsing
+            // and https://url.spec.whatwg.org/#url-code-points
             fn dont_escape(c: u8) -> bool {
                 (b'a' <= c && c <= b'z')
                     || (b'A' <= c && c <= b'Z')
@@ -304,17 +305,32 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
                     || c == b'-'
                     || c == b'_'
                     || c == b'.'
+                    || c == b','
                     || c == b'~'
                     || c == b'!'
                     || c == b'\''
                     || c == b'('
                     || c == b')'
                     || c == b'*'
+                    || c == b'/'
+                    || c == b';'
+                    || c == b':'
+                    || c == b'?'
+                    // As described in urlencoded-parsing, the
+                    // first `=` is the one that separates key from
+                    // value. Following `=`s are part of the value.
+                    || c == b'='
             }
             let mut test_escaped = String::new();
             for b in test.bytes() {
                 if dont_escape(b) {
                     test_escaped.push(char::from(b));
+                } else if b == b' ' {
+                    // URL queries are decoded with + replaced with SP
+                    test_escaped.push('+');
+                } else if b == b'%' {
+                    test_escaped.push('%');
+                    test_escaped.push('%');
                 } else {
                     write!(test_escaped, "%{:02X}", b).unwrap();
                 }
@@ -784,45 +800,26 @@ pub(crate) fn find_testable_code<T: doctest::Tester>(
 }
 
 pub(crate) struct ExtraInfo<'tcx> {
-    id: ExtraInfoId,
+    def_id: DefId,
     sp: Span,
     tcx: TyCtxt<'tcx>,
 }
 
-enum ExtraInfoId {
-    Hir(HirId),
-    Def(DefId),
-}
-
 impl<'tcx> ExtraInfo<'tcx> {
-    pub(crate) fn new(tcx: TyCtxt<'tcx>, hir_id: HirId, sp: Span) -> ExtraInfo<'tcx> {
-        ExtraInfo { id: ExtraInfoId::Hir(hir_id), sp, tcx }
-    }
-
-    pub(crate) fn new_did(tcx: TyCtxt<'tcx>, did: DefId, sp: Span) -> ExtraInfo<'tcx> {
-        ExtraInfo { id: ExtraInfoId::Def(did), sp, tcx }
+    pub(crate) fn new(tcx: TyCtxt<'tcx>, def_id: DefId, sp: Span) -> ExtraInfo<'tcx> {
+        ExtraInfo { def_id, sp, tcx }
     }
 
     fn error_invalid_codeblock_attr(&self, msg: &str, help: &str) {
-        let hir_id = match self.id {
-            ExtraInfoId::Hir(hir_id) => hir_id,
-            ExtraInfoId::Def(item_did) => {
-                match item_did.as_local() {
-                    Some(item_did) => self.tcx.hir().local_def_id_to_hir_id(item_did),
-                    None => {
-                        // If non-local, no need to check anything.
-                        return;
-                    }
-                }
-            }
-        };
-        self.tcx.struct_span_lint_hir(
-            crate::lint::INVALID_CODEBLOCK_ATTRIBUTES,
-            hir_id,
-            self.sp,
-            msg,
-            |lint| lint.help(help),
-        );
+        if let Some(def_id) = self.def_id.as_local() {
+            self.tcx.struct_span_lint_hir(
+                crate::lint::INVALID_CODEBLOCK_ATTRIBUTES,
+                self.tcx.hir().local_def_id_to_hir_id(def_id),
+                self.sp,
+                msg,
+                |lint| lint.help(help),
+            );
+        }
     }
 }
 
@@ -1191,18 +1188,18 @@ fn markdown_summary_with_limit(
             Event::Start(tag) => match tag {
                 Tag::Emphasis => buf.open_tag("em"),
                 Tag::Strong => buf.open_tag("strong"),
-                Tag::CodeBlock(..) => return ControlFlow::BREAK,
+                Tag::CodeBlock(..) => return ControlFlow::Break(()),
                 _ => {}
             },
             Event::End(tag) => match tag {
                 Tag::Emphasis | Tag::Strong => buf.close_tag(),
-                Tag::Paragraph | Tag::Heading(..) => return ControlFlow::BREAK,
+                Tag::Paragraph | Tag::Heading(..) => return ControlFlow::Break(()),
                 _ => {}
             },
             Event::HardBreak | Event::SoftBreak => buf.push(" ")?,
             _ => {}
         };
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     });
 
     (buf.finish(), stopped_early)
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index d644293d3ef..be6de231854 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -1528,11 +1528,7 @@ fn render_impl(
                             })
                         })
                         .map(|item| format!("{}.{}", item.type_(), name));
-                    write!(
-                        w,
-                        "<section id=\"{}\" class=\"{}{} has-srclink\">",
-                        id, item_type, in_trait_class,
-                    );
+                    write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class,);
                     render_rightside(w, cx, item, containing_item, render_mode);
                     if trait_.is_some() {
                         // Anchors are only used on trait impls.
@@ -1554,11 +1550,7 @@ fn render_impl(
             kind @ (clean::TyAssocConstItem(ty) | clean::AssocConstItem(ty, _)) => {
                 let source_id = format!("{}.{}", item_type, name);
                 let id = cx.derive_id(source_id.clone());
-                write!(
-                    w,
-                    "<section id=\"{}\" class=\"{}{} has-srclink\">",
-                    id, item_type, in_trait_class
-                );
+                write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
                 render_rightside(w, cx, item, containing_item, render_mode);
                 if trait_.is_some() {
                     // Anchors are only used on trait impls.
@@ -1606,11 +1598,7 @@ fn render_impl(
             clean::AssocTypeItem(tydef, _bounds) => {
                 let source_id = format!("{}.{}", item_type, name);
                 let id = cx.derive_id(source_id.clone());
-                write!(
-                    w,
-                    "<section id=\"{}\" class=\"{}{} has-srclink\">",
-                    id, item_type, in_trait_class
-                );
+                write!(w, "<section id=\"{}\" class=\"{}{}\">", id, item_type, in_trait_class);
                 if trait_.is_some() {
                     // Anchors are only used on trait impls.
                     write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
@@ -1844,7 +1832,7 @@ pub(crate) fn render_impl_summary(
     } else {
         format!(" data-aliases=\"{}\"", aliases.join(","))
     };
-    write!(w, "<section id=\"{}\" class=\"impl has-srclink\"{}>", id, aliases);
+    write!(w, "<section id=\"{}\" class=\"impl\"{}>", id, aliases);
     render_rightside(w, cx, &i.impl_item, containing_item, RenderMode::Normal);
     write!(w, "<a href=\"#{}\" class=\"anchor\">§</a>", id);
     write!(w, "<h3 class=\"code-header\">");
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index f824c9e3ad2..b0288d55c25 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -391,7 +391,7 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
                 };
                 write!(
                     w,
-                    "<div class=\"item-left {stab}{add}import-item\"{id}>\
+                    "<div class=\"item-left{add}{stab}\"{id}>\
                          <code>{vis}{imp}</code>\
                      </div>\
                      {stab_tags_before}{stab_tags}{stab_tags_after}",
@@ -437,7 +437,7 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
                 };
                 write!(
                     w,
-                    "<div class=\"item-left {stab}{add}module-item\">\
+                    "<div class=\"item-left{add}{stab}\">\
                         <a class=\"{class}\" href=\"{href}\" title=\"{title}\">{name}</a>\
                         {visibility_emoji}\
                         {unsafety_flag}\
@@ -452,7 +452,7 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
                     stab = stab.unwrap_or_default(),
                     unsafety_flag = unsafety_flag,
                     href = item_path(myitem.type_(), myitem.name.unwrap().as_str()),
-                    title = [full_path(cx, myitem), myitem.type_().to_string()]
+                    title = [myitem.type_().to_string(), full_path(cx, myitem)]
                         .iter()
                         .filter_map(|s| if !s.is_empty() { Some(s.as_str()) } else { None })
                         .collect::<Vec<_>>()
@@ -735,7 +735,7 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
             let method_toggle_class = if item_type.is_method() { " method-toggle" } else { "" };
             write!(w, "<details class=\"toggle{method_toggle_class}\" open><summary>");
         }
-        write!(w, "<section id=\"{}\" class=\"method has-srclink\">", id);
+        write!(w, "<section id=\"{}\" class=\"method\">", id);
         render_rightside(w, cx, m, t, RenderMode::Normal);
         write!(w, "<h4 class=\"code-header\">");
         render_assoc_item(
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 424bbb0ec42..8699508e439 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -533,7 +533,7 @@ ul.block, .block li {
 .rustdoc .example-wrap > pre {
 	margin: 0;
 	flex-grow: 1;
-	overflow-x: auto;
+	overflow: auto hidden;
 }
 
 .rustdoc .example-wrap > pre.example-line-numbers,
@@ -977,8 +977,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 		0 -1px 0 black;
 }
 
-.module-item.unstable,
-.import-item.unstable {
+.item-left.unstable {
 	opacity: 0.65;
 }
 
diff --git a/src/librustdoc/html/static/css/settings.css b/src/librustdoc/html/static/css/settings.css
index 4e9803fe236..c28cefebc8b 100644
--- a/src/librustdoc/html/static/css/settings.css
+++ b/src/librustdoc/html/static/css/settings.css
@@ -3,8 +3,7 @@
 	position: relative;
 }
 
-.setting-line .radio-line input,
-.setting-line .settings-toggle input {
+.setting-radio input, .setting-check input {
 	margin-right: 0.3em;
 	height: 1.2rem;
 	width: 1.2rem;
@@ -14,21 +13,20 @@
 	-webkit-appearance: none;
 	cursor: pointer;
 }
-.setting-line .radio-line input {
+.setting-radio input {
 	border-radius: 50%;
 }
-.setting-line .settings-toggle input:checked {
+.setting-check input:checked {
 	content: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40">\
 		<path d="M7,25L17,32L33,12" fill="none" stroke="black" stroke-width="5"/>\
 		<path d="M7,23L17,30L33,10" fill="none" stroke="white" stroke-width="5"/></svg>');
 }
 
-.setting-line .radio-line input + span,
-.setting-line .settings-toggle span {
+.setting-radio span, .setting-check span {
 	padding-bottom: 1px;
 }
 
-.radio-line .choice {
+.setting-radio {
 	margin-top: 0.1em;
 	margin-bottom: 0.1em;
 	min-width: 3.8em;
@@ -37,11 +35,11 @@
 	align-items: center;
 	cursor: pointer;
 }
-.radio-line .choice + .choice {
+.setting-radio + .setting-radio {
 	margin-left: 0.5em;
 }
 
-.settings-toggle {
+.setting-check {
 	position: relative;
 	width: 100%;
 	margin-right: 20px;
@@ -50,23 +48,21 @@
 	cursor: pointer;
 }
 
-.setting-line .radio-line input:checked {
+.setting-radio input:checked {
 	box-shadow: inset 0 0 0 3px var(--main-background-color);
 	background-color: var(--settings-input-color);
 }
-.setting-line .settings-toggle input:checked {
+.setting-check input:checked {
 	background-color: var(--settings-input-color);
 }
-.setting-line .radio-line input:focus,
-.setting-line .settings-toggle input:focus {
+.setting-radio input:focus, .setting-check input:focus {
 	box-shadow: 0 0 1px 1px var(--settings-input-color);
 }
 /* In here we combine both `:focus` and `:checked` properties. */
-.setting-line .radio-line input:checked:focus {
+.setting-radio input:checked:focus {
 	box-shadow: inset 0 0 0 3px var(--main-background-color),
 		0 0 2px 2px var(--settings-input-color);
 }
-.setting-line .radio-line input:hover,
-.setting-line .settings-toggle input:hover {
+.setting-radio input:hover, .setting-check input:hover {
 	border-color: var(--settings-input-color) !important;
 }
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 604ab147f6a..b9ad8ef70e9 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -1142,7 +1142,11 @@ function loadCss(cssUrl) {
 (function() {
     let reset_button_timeout = null;
 
-    window.copy_path = but => {
+    const but = document.getElementById("copy-path");
+    if (!but) {
+        return;
+    }
+    but.onclick = () => {
         const parent = but.parentElement;
         const path = [];
 
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 84df1b7d391..1cd552e7f25 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -1,5 +1,5 @@
 // Local js definitions:
-/* global getSettingValue, getVirtualKey, updateLocalStorage, updateSystemTheme */
+/* global getSettingValue, getVirtualKey, updateLocalStorage, updateTheme */
 /* global addClass, removeClass, onEach, onEachLazy, blurHandler, elemIsInParent */
 /* global MAIN_ID, getVar, getSettingsButton */
 
@@ -19,7 +19,7 @@
             case "theme":
             case "preferred-dark-theme":
             case "preferred-light-theme":
-                updateSystemTheme();
+                updateTheme();
                 updateLightAndDark();
                 break;
             case "line-numbers":
@@ -48,13 +48,13 @@
     }
 
     function showLightAndDark() {
-        removeClass(document.getElementById("preferred-light-theme").parentElement, "hidden");
-        removeClass(document.getElementById("preferred-dark-theme").parentElement, "hidden");
+        removeClass(document.getElementById("preferred-light-theme"), "hidden");
+        removeClass(document.getElementById("preferred-dark-theme"), "hidden");
     }
 
     function hideLightAndDark() {
-        addClass(document.getElementById("preferred-light-theme").parentElement, "hidden");
-        addClass(document.getElementById("preferred-dark-theme").parentElement, "hidden");
+        addClass(document.getElementById("preferred-light-theme"), "hidden");
+        addClass(document.getElementById("preferred-dark-theme"), "hidden");
     }
 
     function updateLightAndDark() {
@@ -80,17 +80,6 @@
             toggle.onkeyup = handleKey;
             toggle.onkeyrelease = handleKey;
         });
-        onEachLazy(settingsElement.getElementsByClassName("select-wrapper"), elem => {
-            const select = elem.getElementsByTagName("select")[0];
-            const settingId = select.id;
-            const settingValue = getSettingValue(settingId);
-            if (settingValue !== null) {
-                select.value = settingValue;
-            }
-            select.onchange = function() {
-                changeSetting(this.id, this.value);
-            };
-        });
         onEachLazy(settingsElement.querySelectorAll("input[type=\"radio\"]"), elem => {
             const settingId = elem.name;
             let settingValue = getSettingValue(settingId);
@@ -127,38 +116,40 @@
         let output = "";
 
         for (const setting of settings) {
-            output += "<div class=\"setting-line\">";
             const js_data_name = setting["js_name"];
             const setting_name = setting["name"];
 
             if (setting["options"] !== undefined) {
                 // This is a select setting.
                 output += `\
-<div class="radio-line" id="${js_data_name}">
-    <div class="setting-name">${setting_name}</div>
-<div class="choices">`;
+<div class="setting-line" id="${js_data_name}">
+    <div class="setting-radio-name">${setting_name}</div>
+    <div class="setting-radio-choices">`;
                 onEach(setting["options"], option => {
                     const checked = option === setting["default"] ? " checked" : "";
                     const full = `${js_data_name}-${option.replace(/ /g,"-")}`;
 
                     output += `\
-<label for="${full}" class="choice">
-    <input type="radio" name="${js_data_name}"
-        id="${full}" value="${option}"${checked}>
-    <span>${option}</span>
-</label>`;
+        <label for="${full}" class="setting-radio">
+            <input type="radio" name="${js_data_name}"
+                id="${full}" value="${option}"${checked}>
+            <span>${option}</span>
+        </label>`;
                 });
-                output += "</div></div>";
+                output += `\
+    </div>
+</div>`;
             } else {
                 // This is a checkbox toggle.
                 const checked = setting["default"] === true ? " checked" : "";
                 output += `\
-<label class="settings-toggle">\
-    <input type="checkbox" id="${js_data_name}"${checked}>\
-    <span class="label">${setting_name}</span>\
-</label>`;
+<div class="setting-line">\
+    <label class="setting-check">\
+        <input type="checkbox" id="${js_data_name}"${checked}>\
+        <span>${setting_name}</span>\
+    </label>\
+</div>`;
             }
-            output += "</div>";
         }
         return output;
     }
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index db2db83ca63..8836d1b2e46 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -153,79 +153,74 @@ function switchTheme(styleElem, mainStyleElem, newThemeName, saveTheme) {
     }
 }
 
-// This function is called from "main.js".
-// eslint-disable-next-line no-unused-vars
-function useSystemTheme(value) {
-    if (value === undefined) {
-        value = true;
-    }
-
-    updateLocalStorage("use-system-theme", value);
-
-    // update the toggle if we're on the settings page
-    const toggle = document.getElementById("use-system-theme");
-    if (toggle && toggle instanceof HTMLInputElement) {
-        toggle.checked = value;
-    }
-}
-
-const updateSystemTheme = (function() {
-    if (!window.matchMedia) {
-        // fallback to the CSS computed value
-        return () => {
-            const cssTheme = getComputedStyle(document.documentElement)
-                .getPropertyValue("content");
-
-            switchTheme(
-                window.currentTheme,
-                window.mainTheme,
-                JSON.parse(cssTheme) || "light",
-                true
-            );
+const updateTheme = (function() {
+    /**
+     * Update the current theme to match whatever the current combination of
+     * * the preference for using the system theme
+     *   (if this is the case, the value of preferred-light-theme, if the
+     *   system theme is light, otherwise if dark, the value of
+     *   preferred-dark-theme.)
+     * * the preferred theme
+     * … dictates that it should be.
+     */
+    function updateTheme() {
+        const use = (theme, saveTheme) => {
+            switchTheme(window.currentTheme, window.mainTheme, theme, saveTheme);
         };
-    }
-
-    // only listen to (prefers-color-scheme: dark) because light is the default
-    const mql = window.matchMedia("(prefers-color-scheme: dark)");
 
-    function handlePreferenceChange(mql) {
-        const use = theme => {
-            switchTheme(window.currentTheme, window.mainTheme, theme, true);
-        };
         // maybe the user has disabled the setting in the meantime!
         if (getSettingValue("use-system-theme") !== "false") {
             const lightTheme = getSettingValue("preferred-light-theme") || "light";
             const darkTheme = getSettingValue("preferred-dark-theme") || "dark";
 
-            if (mql.matches) {
-                use(darkTheme);
+            if (isDarkMode()) {
+                use(darkTheme, true);
             } else {
                 // prefers a light theme, or has no preference
-                use(lightTheme);
+                use(lightTheme, true);
             }
             // note: we save the theme so that it doesn't suddenly change when
             // the user disables "use-system-theme" and reloads the page or
             // navigates to another page
         } else {
-            use(getSettingValue("theme"));
+            use(getSettingValue("theme"), false);
         }
     }
 
-    mql.addListener(handlePreferenceChange);
+    // This is always updated below to a function () => bool.
+    let isDarkMode;
 
-    return () => {
-        handlePreferenceChange(mql);
-    };
-})();
+    // Determine the function for isDarkMode, and if we have
+    // `window.matchMedia`, set up an event listener on the preferred color
+    // scheme.
+    //
+    // Otherwise, fall back to the prefers-color-scheme value CSS captured in
+    // the "content" property.
+    if (window.matchMedia) {
+        // only listen to (prefers-color-scheme: dark) because light is the default
+        const mql = window.matchMedia("(prefers-color-scheme: dark)");
 
-function switchToSavedTheme() {
-    switchTheme(
-        window.currentTheme,
-        window.mainTheme,
-        getSettingValue("theme") || "light",
-        false
-    );
-}
+        isDarkMode = () => mql.matches;
+
+        if (mql.addEventListener) {
+            mql.addEventListener("change", updateTheme);
+        } else {
+            // This is deprecated, see:
+            // https://developer.mozilla.org/en-US/docs/Web/API/MediaQueryList/addListener
+            mql.addListener(updateTheme);
+        }
+    } else {
+        // fallback to the CSS computed value
+        const cssContent = getComputedStyle(document.documentElement)
+            .getPropertyValue("content");
+        // (Note: the double-quotes come from that this is a CSS value, which
+        // might be a length, string, etc.)
+        const cssColorScheme = cssContent || "\"light\"";
+        isDarkMode = () => (cssColorScheme === "\"dark\"");
+    }
+
+    return updateTheme;
+})();
 
 if (getSettingValue("use-system-theme") !== "false" && window.matchMedia) {
     // update the preferred dark theme if the user is already using a dark theme
@@ -235,13 +230,10 @@ if (getSettingValue("use-system-theme") !== "false" && window.matchMedia) {
         && darkThemes.indexOf(localStoredTheme) >= 0) {
         updateLocalStorage("preferred-dark-theme", localStoredTheme);
     }
-
-    // call the function to initialize the theme at least once!
-    updateSystemTheme();
-} else {
-    switchToSavedTheme();
 }
 
+updateTheme();
+
 if (getSettingValue("source-sidebar-show") === "true") {
     // At this point in page load, `document.body` is not available yet.
     // Set a class on the `<html>` element instead.
@@ -259,6 +251,6 @@ if (getSettingValue("source-sidebar-show") === "true") {
 // specifically when talking to a remote website with no caching.
 window.addEventListener("pageshow", ev => {
     if (ev.persisted) {
-        setTimeout(switchToSavedTheme, 0);
+        setTimeout(updateTheme, 0);
     }
 });
diff --git a/src/librustdoc/html/templates/print_item.html b/src/librustdoc/html/templates/print_item.html
index ee2880bf6d1..3a1867b7feb 100644
--- a/src/librustdoc/html/templates/print_item.html
+++ b/src/librustdoc/html/templates/print_item.html
@@ -6,7 +6,7 @@
         <a href="{{component.path|safe}}index.html">{{component.name}}</a>::<wbr>
         {%- endfor -%}
         <a class="{{item_type}}" href="#">{{name}}</a> {#- -#}
-        <button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"> {#- -#}
+        <button id="copy-path" title="Copy item path to clipboard"> {#- -#}
         <img src="{{static_root_path|safe}}{{clipboard_svg}}" {# -#}
                 width="19" height="18" {# -#}
                 alt="Copy item path"> {#- -#}
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 86454e1f2eb..64108c88285 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -6,7 +6,6 @@
 #![feature(array_methods)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(drain_filter)]
 #![feature(is_terminal)]
 #![feature(let_chains)]
@@ -815,7 +814,7 @@ fn main_args(at_args: &[String]) -> MainResult {
                 sess.fatal("Compilation failed, aborting rustdoc");
             }
 
-            let global_ctxt = abort_on_err(queries.global_ctxt(), sess);
+            let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess);
 
             global_ctxt.enter(|tcx| {
                 let (krate, render_opts, mut cache) = sess.time("run_global_ctxt", || {
diff --git a/src/librustdoc/passes/calculate_doc_coverage.rs b/src/librustdoc/passes/calculate_doc_coverage.rs
index 02b22789608..0b22f943dab 100644
--- a/src/librustdoc/passes/calculate_doc_coverage.rs
+++ b/src/librustdoc/passes/calculate_doc_coverage.rs
@@ -216,13 +216,7 @@ impl<'a, 'b> DocVisitor for CoverageCalculator<'a, 'b> {
                 );
 
                 let has_doc_example = tests.found_tests != 0;
-                // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
-                // would presumably panic if a fake `DefIndex` were passed.
-                let hir_id = self
-                    .ctx
-                    .tcx
-                    .hir()
-                    .local_def_id_to_hir_id(i.item_id.expect_def_id().expect_local());
+                let hir_id = DocContext::as_local_hir_id(self.ctx.tcx, i.item_id).unwrap();
                 let (level, source) = self.ctx.tcx.lint_level_at_node(MISSING_DOCS, hir_id);
 
                 // In case we have:
diff --git a/src/librustdoc/passes/check_doc_test_visibility.rs b/src/librustdoc/passes/check_doc_test_visibility.rs
index 6aa2dda980c..f3961d5017e 100644
--- a/src/librustdoc/passes/check_doc_test_visibility.rs
+++ b/src/librustdoc/passes/check_doc_test_visibility.rs
@@ -14,8 +14,8 @@ use crate::visit::DocVisitor;
 use crate::visit_ast::inherits_doc_hidden;
 use rustc_hir as hir;
 use rustc_middle::lint::LintLevelSource;
+use rustc_middle::ty::DefIdTree;
 use rustc_session::lint;
-use rustc_span::symbol::sym;
 
 pub(crate) const CHECK_DOC_TEST_VISIBILITY: Pass = Pass {
     name: "check_doc_test_visibility",
@@ -79,11 +79,11 @@ pub(crate) fn should_have_doc_example(cx: &DocContext<'_>, item: &clean::Item) -
 
     // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
     // would presumably panic if a fake `DefIndex` were passed.
-    let hir_id = cx.tcx.hir().local_def_id_to_hir_id(item.item_id.expect_def_id().expect_local());
+    let def_id = item.item_id.expect_def_id().expect_local();
 
     // check if parent is trait impl
-    if let Some(parent_hir_id) = cx.tcx.hir().opt_parent_id(hir_id) {
-        if let Some(parent_node) = cx.tcx.hir().find(parent_hir_id) {
+    if let Some(parent_def_id) = cx.tcx.opt_local_parent(def_id) {
+        if let Some(parent_node) = cx.tcx.hir().find_by_def_id(parent_def_id) {
             if matches!(
                 parent_node,
                 hir::Node::Item(hir::Item {
@@ -96,13 +96,16 @@ pub(crate) fn should_have_doc_example(cx: &DocContext<'_>, item: &clean::Item) -
         }
     }
 
-    if cx.tcx.hir().attrs(hir_id).lists(sym::doc).has_word(sym::hidden)
-        || inherits_doc_hidden(cx.tcx, hir_id)
-        || cx.tcx.hir().span(hir_id).in_derive_expansion()
+    if cx.tcx.is_doc_hidden(def_id.to_def_id())
+        || inherits_doc_hidden(cx.tcx, def_id)
+        || cx.tcx.def_span(def_id.to_def_id()).in_derive_expansion()
     {
         return false;
     }
-    let (level, source) = cx.tcx.lint_level_at_node(crate::lint::MISSING_DOC_CODE_EXAMPLES, hir_id);
+    let (level, source) = cx.tcx.lint_level_at_node(
+        crate::lint::MISSING_DOC_CODE_EXAMPLES,
+        cx.tcx.hir().local_def_id_to_hir_id(def_id),
+    );
     level != lint::Level::Allow || matches!(source, LintLevelSource::Default)
 }
 
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 075951312a6..8435972bb11 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -542,6 +542,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(_)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Dynamic(..)
             | ty::Param(_)
             | ty::Bound(..)
@@ -1194,14 +1195,9 @@ impl LinkCollector<'_, '_> {
             }
 
         // item can be non-local e.g. when using #[doc(primitive = "pointer")]
-        if let Some((src_id, dst_id)) = id
-            .as_local()
-            // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
-            // would presumably panic if a fake `DefIndex` were passed.
-            .and_then(|dst_id| {
-                item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
-            })
-        {
+        if let Some((src_id, dst_id)) = id.as_local().and_then(|dst_id| {
+            item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
+        }) {
             if self.cx.tcx.effective_visibilities(()).is_exported(src_id)
                 && !self.cx.tcx.effective_visibilities(()).is_exported(dst_id)
             {
diff --git a/src/librustdoc/passes/collect_intra_doc_links/early.rs b/src/librustdoc/passes/collect_intra_doc_links/early.rs
index 42677bd8497..f690c49005d 100644
--- a/src/librustdoc/passes/collect_intra_doc_links/early.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links/early.rs
@@ -2,6 +2,7 @@ use crate::clean::Attributes;
 use crate::core::ResolverCaches;
 use crate::passes::collect_intra_doc_links::preprocessed_markdown_links;
 use crate::passes::collect_intra_doc_links::{Disambiguator, PreprocessedMarkdownLink};
+use crate::visit_lib::early_lib_embargo_visit_item;
 
 use rustc_ast::visit::{self, AssocCtxt, Visitor};
 use rustc_ast::{self as ast, ItemKind};
@@ -34,6 +35,8 @@ pub(crate) fn early_resolve_intra_doc_links(
         traits_in_scope: Default::default(),
         all_trait_impls: Default::default(),
         all_macro_rules: Default::default(),
+        extern_doc_reachable: Default::default(),
+        local_doc_reachable: Default::default(),
         document_private_items,
     };
 
@@ -61,6 +64,7 @@ pub(crate) fn early_resolve_intra_doc_links(
         traits_in_scope: link_resolver.traits_in_scope,
         all_trait_impls: Some(link_resolver.all_trait_impls),
         all_macro_rules: link_resolver.all_macro_rules,
+        extern_doc_reachable: link_resolver.extern_doc_reachable,
     }
 }
 
@@ -77,6 +81,15 @@ struct EarlyDocLinkResolver<'r, 'ra> {
     traits_in_scope: DefIdMap<Vec<TraitCandidate>>,
     all_trait_impls: Vec<DefId>,
     all_macro_rules: FxHashMap<Symbol, Res<ast::NodeId>>,
+    /// This set is used as a seed for `effective_visibilities`, which are then extended by some
+    /// more items using `lib_embargo_visit_item` during doc inlining.
+    extern_doc_reachable: DefIdSet,
+    /// This is an easily identifiable superset of items added to `effective_visibilities`
+    /// using `lib_embargo_visit_item` during doc inlining.
+    /// The union of `(extern,local)_doc_reachable` is therefore a superset of
+    /// `effective_visibilities` and can be used for pruning extern impls here
+    /// in early doc link resolution.
+    local_doc_reachable: DefIdSet,
     document_private_items: bool,
 }
 
@@ -105,6 +118,10 @@ impl<'ra> EarlyDocLinkResolver<'_, 'ra> {
         }
     }
 
+    fn is_doc_reachable(&self, def_id: DefId) -> bool {
+        self.extern_doc_reachable.contains(&def_id) || self.local_doc_reachable.contains(&def_id)
+    }
+
     /// Add traits in scope for links in impls collected by the `collect-intra-doc-links` pass.
     /// That pass filters impls using type-based information, but we don't yet have such
     /// information here, so we just conservatively calculate traits in scope for *all* modules
@@ -114,6 +131,14 @@ impl<'ra> EarlyDocLinkResolver<'_, 'ra> {
         let mut start_cnum = 0;
         loop {
             let crates = Vec::from_iter(self.resolver.cstore().crates_untracked());
+            for cnum in &crates[start_cnum..] {
+                early_lib_embargo_visit_item(
+                    self.resolver,
+                    &mut self.extern_doc_reachable,
+                    cnum.as_def_id(),
+                    true,
+                );
+            }
             for &cnum in &crates[start_cnum..] {
                 let all_trait_impls =
                     Vec::from_iter(self.resolver.cstore().trait_impls_in_crate_untracked(cnum));
@@ -127,28 +152,26 @@ impl<'ra> EarlyDocLinkResolver<'_, 'ra> {
                 // privacy, private traits and impls from other crates are never documented in
                 // the current crate, and links in their doc comments are not resolved.
                 for &(trait_def_id, impl_def_id, simplified_self_ty) in &all_trait_impls {
-                    if self.resolver.cstore().visibility_untracked(trait_def_id).is_public()
-                        && simplified_self_ty.and_then(|ty| ty.def()).map_or(true, |ty_def_id| {
-                            self.resolver.cstore().visibility_untracked(ty_def_id).is_public()
-                        })
+                    if self.is_doc_reachable(trait_def_id)
+                        && simplified_self_ty
+                            .and_then(|ty| ty.def())
+                            .map_or(true, |ty_def_id| self.is_doc_reachable(ty_def_id))
                     {
                         if self.visited_mods.insert(trait_def_id) {
                             self.resolve_doc_links_extern_impl(trait_def_id, false);
                         }
                         self.resolve_doc_links_extern_impl(impl_def_id, false);
                     }
+                    self.all_trait_impls.push(impl_def_id);
                 }
                 for (ty_def_id, impl_def_id) in all_inherent_impls {
-                    if self.resolver.cstore().visibility_untracked(ty_def_id).is_public() {
+                    if self.is_doc_reachable(ty_def_id) {
                         self.resolve_doc_links_extern_impl(impl_def_id, true);
                     }
                 }
                 for impl_def_id in all_incoherent_impls {
                     self.resolve_doc_links_extern_impl(impl_def_id, true);
                 }
-
-                self.all_trait_impls
-                    .extend(all_trait_impls.into_iter().map(|(_, def_id, _)| def_id));
             }
 
             if crates.len() > start_cnum {
@@ -298,6 +321,7 @@ impl<'ra> EarlyDocLinkResolver<'_, 'ra> {
                     && module_id.is_local()
             {
                 if let Some(def_id) = child.res.opt_def_id() && !def_id.is_local() {
+                    self.local_doc_reachable.insert(def_id);
                     let scope_id = match child.res {
                         Res::Def(
                             DefKind::Variant
diff --git a/src/librustdoc/passes/lint/check_code_block_syntax.rs b/src/librustdoc/passes/lint/check_code_block_syntax.rs
index 7158355ffda..03be5e79971 100644
--- a/src/librustdoc/passes/lint/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/lint/check_code_block_syntax.rs
@@ -19,8 +19,7 @@ use crate::passes::source_span_for_markdown_range;
 pub(crate) fn visit_item(cx: &DocContext<'_>, item: &clean::Item) {
     if let Some(dox) = &item.attrs.collapsed_doc_value() {
         let sp = item.attr_span(cx.tcx);
-        let extra =
-            crate::html::markdown::ExtraInfo::new_did(cx.tcx, item.item_id.expect_def_id(), sp);
+        let extra = crate::html::markdown::ExtraInfo::new(cx.tcx, item.item_id.expect_def_id(), sp);
         for code_block in markdown::rust_code_blocks(dox, &extra) {
             check_rust_syntax(cx, item, dox, code_block);
         }
@@ -73,7 +72,6 @@ fn check_rust_syntax(
             return;
         };
 
-    let hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_id);
     let empty_block = code_block.lang_string == Default::default() && code_block.is_fenced;
     let is_ignore = code_block.lang_string.ignore != markdown::Ignore::None;
 
@@ -93,6 +91,7 @@ fn check_rust_syntax(
     // Finally build and emit the completed diagnostic.
     // All points of divergence have been handled earlier so this can be
     // done the same way whether the span is precise or not.
+    let hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_id);
     cx.tcx.struct_span_lint_hir(crate::lint::INVALID_RUST_CODEBLOCKS, hir_id, sp, msg, |lint| {
         let explanation = if is_ignore {
             "`ignore` code blocks require valid Rust code for syntax highlighting; \
diff --git a/src/librustdoc/passes/propagate_doc_cfg.rs b/src/librustdoc/passes/propagate_doc_cfg.rs
index de3a4b33905..a4bc486900b 100644
--- a/src/librustdoc/passes/propagate_doc_cfg.rs
+++ b/src/librustdoc/passes/propagate_doc_cfg.rs
@@ -9,6 +9,7 @@ use crate::fold::DocFolder;
 use crate::passes::Pass;
 
 use rustc_hir::def_id::LocalDefId;
+use rustc_middle::ty::DefIdTree;
 
 pub(crate) const PROPAGATE_DOC_CFG: Pass = Pass {
     name: "propagate-doc-cfg",
@@ -41,24 +42,22 @@ impl<'a, 'tcx> CfgPropagator<'a, 'tcx> {
         let Some(def_id) = item.item_id.as_def_id().and_then(|def_id| def_id.as_local())
             else { return };
 
-        let hir = self.cx.tcx.hir();
-        let hir_id = hir.local_def_id_to_hir_id(def_id);
-
         if check_parent {
-            let expected_parent = hir.get_parent_item(hir_id);
+            let expected_parent = self.cx.tcx.opt_local_parent(def_id);
             // If parents are different, it means that `item` is a reexport and we need
             // to compute the actual `cfg` by iterating through its "real" parents.
-            if self.parent == Some(expected_parent.def_id) {
+            if self.parent.is_some() && self.parent == expected_parent {
                 return;
             }
         }
 
         let mut attrs = Vec::new();
-        for (parent_hir_id, _) in hir.parent_iter(hir_id) {
-            if let Some(def_id) = hir.opt_local_def_id(parent_hir_id) {
-                attrs.extend_from_slice(load_attrs(self.cx, def_id.to_def_id()));
-            }
+        let mut next_def_id = def_id;
+        while let Some(parent_def_id) = self.cx.tcx.opt_local_parent(next_def_id) {
+            attrs.extend_from_slice(load_attrs(self.cx, parent_def_id.to_def_id()));
+            next_def_id = parent_def_id;
         }
+
         let (_, cfg) = merge_attrs(self.cx, None, item.attrs.other_attrs.as_slice(), Some(&attrs));
         item.cfg = cfg;
     }
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 00ea6ca4152..a89d6fa8398 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -4,9 +4,9 @@
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, DefIdMap};
-use rustc_hir::{HirIdSet, Node, CRATE_HIR_ID};
-use rustc_middle::ty::TyCtxt;
+use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId, LocalDefIdSet};
+use rustc_hir::{Node, CRATE_HIR_ID};
+use rustc_middle::ty::{DefIdTree, TyCtxt};
 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
@@ -23,19 +23,26 @@ pub(crate) struct Module<'hir> {
     pub(crate) name: Symbol,
     pub(crate) where_inner: Span,
     pub(crate) mods: Vec<Module<'hir>>,
-    pub(crate) id: hir::HirId,
+    pub(crate) def_id: LocalDefId,
     // (item, renamed, import_id)
-    pub(crate) items: Vec<(&'hir hir::Item<'hir>, Option<Symbol>, Option<hir::HirId>)>,
+    pub(crate) items: Vec<(&'hir hir::Item<'hir>, Option<Symbol>, Option<LocalDefId>)>,
     pub(crate) foreigns: Vec<(&'hir hir::ForeignItem<'hir>, Option<Symbol>)>,
 }
 
 impl Module<'_> {
-    pub(crate) fn new(name: Symbol, id: hir::HirId, where_inner: Span) -> Self {
-        Module { name, id, where_inner, mods: Vec::new(), items: Vec::new(), foreigns: Vec::new() }
+    pub(crate) fn new(name: Symbol, def_id: LocalDefId, where_inner: Span) -> Self {
+        Module {
+            name,
+            def_id,
+            where_inner,
+            mods: Vec::new(),
+            items: Vec::new(),
+            foreigns: Vec::new(),
+        }
     }
 
     pub(crate) fn where_outer(&self, tcx: TyCtxt<'_>) -> Span {
-        tcx.hir().span(self.id)
+        tcx.def_span(self.def_id)
     }
 }
 
@@ -46,10 +53,10 @@ fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<Symbol> {
     std::iter::once(crate_name).chain(relative).collect()
 }
 
-pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool {
-    while let Some(id) = tcx.hir().get_enclosing_scope(node) {
+pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: LocalDefId) -> bool {
+    while let Some(id) = tcx.opt_local_parent(node) {
         node = id;
-        if tcx.hir().attrs(node).lists(sym::doc).has_word(sym::hidden) {
+        if tcx.is_doc_hidden(node.to_def_id()) {
             return true;
         }
     }
@@ -61,7 +68,7 @@ pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: hir::HirId) -> bool
 
 pub(crate) struct RustdocVisitor<'a, 'tcx> {
     cx: &'a mut core::DocContext<'tcx>,
-    view_item_stack: HirIdSet,
+    view_item_stack: LocalDefIdSet,
     inlining: bool,
     /// Are the current module and all of its parents public?
     inside_public_path: bool,
@@ -71,8 +78,8 @@ pub(crate) struct RustdocVisitor<'a, 'tcx> {
 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
     pub(crate) fn new(cx: &'a mut core::DocContext<'tcx>) -> RustdocVisitor<'a, 'tcx> {
         // If the root is re-exported, terminate all recursion.
-        let mut stack = HirIdSet::default();
-        stack.insert(hir::CRATE_HIR_ID);
+        let mut stack = LocalDefIdSet::default();
+        stack.insert(CRATE_DEF_ID);
         RustdocVisitor {
             cx,
             view_item_stack: stack,
@@ -89,7 +96,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
 
     pub(crate) fn visit(mut self) -> Module<'tcx> {
         let mut top_level_module = self.visit_mod_contents(
-            hir::CRATE_HIR_ID,
+            CRATE_DEF_ID,
             self.cx.tcx.hir().root_module(),
             self.cx.tcx.crate_name(LOCAL_CRATE),
             None,
@@ -152,16 +159,15 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
 
     fn visit_mod_contents(
         &mut self,
-        id: hir::HirId,
+        def_id: LocalDefId,
         m: &'tcx hir::Mod<'tcx>,
         name: Symbol,
-        parent_id: Option<hir::HirId>,
+        parent_id: Option<LocalDefId>,
     ) -> Module<'tcx> {
-        let mut om = Module::new(name, id, m.spans.inner_span);
-        let def_id = self.cx.tcx.hir().local_def_id(id).to_def_id();
+        let mut om = Module::new(name, def_id, m.spans.inner_span);
         // Keep track of if there were any private modules in the path.
         let orig_inside_public_path = self.inside_public_path;
-        self.inside_public_path &= self.cx.tcx.visibility(def_id).is_public();
+        self.inside_public_path &= self.cx.tcx.local_visibility(def_id).is_public();
         for &i in m.item_ids {
             let item = self.cx.tcx.hir().item(i);
             if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
@@ -193,7 +199,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
     /// Returns `true` if the target has been inlined.
     fn maybe_inline_local(
         &mut self,
-        id: hir::HirId,
+        def_id: LocalDefId,
         res: Res,
         renamed: Option<Symbol>,
         glob: bool,
@@ -211,10 +217,10 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             return false;
         };
 
-        let use_attrs = tcx.hir().attrs(id);
+        let use_attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(def_id));
         // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
         let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
-            || use_attrs.lists(sym::doc).has_word(sym::hidden);
+            || tcx.is_doc_hidden(def_id.to_def_id());
 
         // For cross-crate impl inlining we need to know whether items are
         // reachable in documentation -- a previously unreachable item can be
@@ -225,37 +231,39 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             return false;
         }
 
-        let res_hir_id = match res_did.as_local() {
-            Some(n) => tcx.hir().local_def_id_to_hir_id(n),
-            None => return false,
+        let Some(res_did) = res_did.as_local() else {
+            return false;
         };
 
-        let is_private =
-            !self.cx.cache.effective_visibilities.is_directly_public(self.cx.tcx, res_did);
-        let is_hidden = inherits_doc_hidden(self.cx.tcx, res_hir_id);
+        let is_private = !self
+            .cx
+            .cache
+            .effective_visibilities
+            .is_directly_public(self.cx.tcx, res_did.to_def_id());
+        let is_hidden = inherits_doc_hidden(self.cx.tcx, res_did);
 
         // Only inline if requested or if the item would otherwise be stripped.
         if (!please_inline && !is_private && !is_hidden) || is_no_inline {
             return false;
         }
 
-        if !self.view_item_stack.insert(res_hir_id) {
+        if !self.view_item_stack.insert(res_did) {
             return false;
         }
 
-        let ret = match tcx.hir().get(res_hir_id) {
+        let ret = match tcx.hir().get_by_def_id(res_did) {
             Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
                 let prev = mem::replace(&mut self.inlining, true);
                 for &i in m.item_ids {
                     let i = self.cx.tcx.hir().item(i);
-                    self.visit_item(i, None, om, Some(id));
+                    self.visit_item(i, None, om, Some(def_id));
                 }
                 self.inlining = prev;
                 true
             }
             Node::Item(it) if !glob => {
                 let prev = mem::replace(&mut self.inlining, true);
-                self.visit_item(it, renamed, om, Some(id));
+                self.visit_item(it, renamed, om, Some(def_id));
                 self.inlining = prev;
                 true
             }
@@ -267,7 +275,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             }
             _ => false,
         };
-        self.view_item_stack.remove(&res_hir_id);
+        self.view_item_stack.remove(&res_did);
         ret
     }
 
@@ -276,7 +284,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         item: &'tcx hir::Item<'_>,
         renamed: Option<Symbol>,
         om: &mut Module<'tcx>,
-        parent_id: Option<hir::HirId>,
+        parent_id: Option<LocalDefId>,
     ) {
         debug!("visiting item {:?}", item);
         let name = renamed.unwrap_or(item.ident.name);
@@ -321,7 +329,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                         let is_glob = kind == hir::UseKind::Glob;
                         let ident = if is_glob { None } else { Some(name) };
                         if self.maybe_inline_local(
-                            item.hir_id(),
+                            item.owner_id.def_id,
                             res,
                             ident,
                             is_glob,
@@ -356,7 +364,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 }
             }
             hir::ItemKind::Mod(ref m) => {
-                om.mods.push(self.visit_mod_contents(item.hir_id(), m, name, parent_id));
+                om.mods.push(self.visit_mod_contents(item.owner_id.def_id, m, name, parent_id));
             }
             hir::ItemKind::Fn(..)
             | hir::ItemKind::ExternCrate(..)
diff --git a/src/librustdoc/visit_lib.rs b/src/librustdoc/visit_lib.rs
index fd4f9254107..07d8b78d767 100644
--- a/src/librustdoc/visit_lib.rs
+++ b/src/librustdoc/visit_lib.rs
@@ -1,7 +1,8 @@
 use crate::core::DocContext;
-use rustc_hir::def::DefKind;
+use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_middle::ty::TyCtxt;
+use rustc_resolve::Resolver;
 
 // FIXME: this may not be exhaustive, but is sufficient for rustdocs current uses
 
@@ -25,6 +26,10 @@ impl RustdocEffectiveVisibilities {
     define_method!(is_directly_public);
     define_method!(is_exported);
     define_method!(is_reachable);
+
+    pub(crate) fn init(&mut self, extern_public: DefIdSet) {
+        self.extern_public = extern_public;
+    }
 }
 
 pub(crate) fn lib_embargo_visit_item(cx: &mut DocContext<'_>, def_id: DefId) {
@@ -37,6 +42,17 @@ pub(crate) fn lib_embargo_visit_item(cx: &mut DocContext<'_>, def_id: DefId) {
     .visit_item(def_id)
 }
 
+pub(crate) fn early_lib_embargo_visit_item(
+    resolver: &Resolver<'_>,
+    extern_public: &mut DefIdSet,
+    def_id: DefId,
+    is_mod: bool,
+) {
+    assert!(!def_id.is_local());
+    EarlyLibEmbargoVisitor { resolver, extern_public, visited_mods: Default::default() }
+        .visit_item(def_id, is_mod)
+}
+
 /// Similar to `librustc_privacy::EmbargoVisitor`, but also takes
 /// specific rustdoc annotations into account (i.e., `doc(hidden)`)
 struct LibEmbargoVisitor<'a, 'tcx> {
@@ -47,6 +63,14 @@ struct LibEmbargoVisitor<'a, 'tcx> {
     visited_mods: DefIdSet,
 }
 
+struct EarlyLibEmbargoVisitor<'r, 'ra> {
+    resolver: &'r Resolver<'ra>,
+    // Effective visibilities for reachable nodes
+    extern_public: &'r mut DefIdSet,
+    // Keeps track of already visited modules, in case a module re-exports its parent
+    visited_mods: DefIdSet,
+}
+
 impl LibEmbargoVisitor<'_, '_> {
     fn visit_mod(&mut self, def_id: DefId) {
         if !self.visited_mods.insert(def_id) {
@@ -71,3 +95,28 @@ impl LibEmbargoVisitor<'_, '_> {
         }
     }
 }
+
+impl EarlyLibEmbargoVisitor<'_, '_> {
+    fn visit_mod(&mut self, def_id: DefId) {
+        if !self.visited_mods.insert(def_id) {
+            return;
+        }
+
+        for item in self.resolver.cstore().module_children_untracked(def_id, self.resolver.sess()) {
+            if let Some(def_id) = item.res.opt_def_id() {
+                if item.vis.is_public() {
+                    self.visit_item(def_id, matches!(item.res, Res::Def(DefKind::Mod, _)));
+                }
+            }
+        }
+    }
+
+    fn visit_item(&mut self, def_id: DefId, is_mod: bool) {
+        if !self.resolver.cstore().is_doc_hidden_untracked(def_id) {
+            self.extern_public.insert(def_id);
+            if is_mod {
+                self.visit_mod(def_id);
+            }
+        }
+    }
+}
diff --git a/src/tools/cargo b/src/tools/cargo
-Subproject 985d561f0bb9b76ec043a2b12511790ec7a2b95
+Subproject 3c5af6bed9a1a243a693e8e22ee2486bd5b82a6
diff --git a/src/tools/clippy/.github/workflows/clippy_bors.yml b/src/tools/clippy/.github/workflows/clippy_bors.yml
index 1bc457a9479..24e677ce8e1 100644
--- a/src/tools/clippy/.github/workflows/clippy_bors.yml
+++ b/src/tools/clippy/.github/workflows/clippy_bors.yml
@@ -157,6 +157,11 @@ jobs:
     - name: Test metadata collection
       run: cargo collect-metadata
 
+    - name: Test lint_configuration.md is up-to-date
+      run: |
+        echo "run \`cargo collect-metadata\` if this fails"
+        git update-index --refresh
+
   integration_build:
     needs: changelog
     runs-on: ubuntu-latest
diff --git a/src/tools/clippy/CHANGELOG.md b/src/tools/clippy/CHANGELOG.md
index 8e31e8f0d98..e2cde09776f 100644
--- a/src/tools/clippy/CHANGELOG.md
+++ b/src/tools/clippy/CHANGELOG.md
@@ -6,11 +6,204 @@ document.
 
 ## Unreleased / Beta / In Rust Nightly
 
-[4f142aa1...master](https://github.com/rust-lang/rust-clippy/compare/4f142aa1...master)
+[d822110d...master](https://github.com/rust-lang/rust-clippy/compare/d822110d...master)
+
+## Rust 1.67
+
+Current stable, released 2023-01-26
+
+[4f142aa1...d822110d](https://github.com/rust-lang/rust-clippy/compare/4f142aa1...d822110d)
+
+### New Lints
+
+* [`seek_from_current`]
+  [#9681](https://github.com/rust-lang/rust-clippy/pull/9681)
+* [`from_raw_with_void_ptr`]
+  [#9690](https://github.com/rust-lang/rust-clippy/pull/9690)
+* [`misnamed_getters`]
+  [#9770](https://github.com/rust-lang/rust-clippy/pull/9770)
+* [`seek_to_start_instead_of_rewind`]
+  [#9667](https://github.com/rust-lang/rust-clippy/pull/9667)
+* [`suspicious_xor_used_as_pow`]
+  [#9506](https://github.com/rust-lang/rust-clippy/pull/9506)
+* [`unnecessary_safety_doc`]
+  [#9822](https://github.com/rust-lang/rust-clippy/pull/9822)
+* [`unchecked_duration_subtraction`]
+  [#9570](https://github.com/rust-lang/rust-clippy/pull/9570)
+* [`manual_is_ascii_check`]
+  [#9765](https://github.com/rust-lang/rust-clippy/pull/9765)
+* [`unnecessary_safety_comment`]
+  [#9851](https://github.com/rust-lang/rust-clippy/pull/9851)
+* [`let_underscore_future`]
+  [#9760](https://github.com/rust-lang/rust-clippy/pull/9760)
+* [`manual_let_else`]
+  [#8437](https://github.com/rust-lang/rust-clippy/pull/8437)
+
+### Moves and Deprecations
+
+* Moved [`uninlined_format_args`] to `style` (Now warn-by-default)
+  [#9865](https://github.com/rust-lang/rust-clippy/pull/9865)
+* Moved [`needless_collect`] to `nursery` (Now allow-by-default)
+  [#9705](https://github.com/rust-lang/rust-clippy/pull/9705)
+* Moved [`or_fun_call`] to `nursery` (Now allow-by-default)
+  [#9829](https://github.com/rust-lang/rust-clippy/pull/9829)
+* Uplifted [`let_underscore_lock`] into rustc
+  [#9697](https://github.com/rust-lang/rust-clippy/pull/9697)
+* Uplifted [`let_underscore_drop`] into rustc
+  [#9697](https://github.com/rust-lang/rust-clippy/pull/9697)
+* Moved [`bool_to_int_with_if`] to `pedantic` (Now allow-by-default)
+  [#9830](https://github.com/rust-lang/rust-clippy/pull/9830)
+* Move `index_refutable_slice` to `pedantic` (Now warn-by-default)
+  [#9975](https://github.com/rust-lang/rust-clippy/pull/9975)
+* Moved [`manual_clamp`] to `nursery` (Now allow-by-default)
+  [#10101](https://github.com/rust-lang/rust-clippy/pull/10101)
+
+### Enhancements
+
+* The scope of `#![clippy::msrv]` is now tracked correctly
+  [#9924](https://github.com/rust-lang/rust-clippy/pull/9924)
+* `#[clippy::msrv]` can now be used as an outer attribute
+  [#9860](https://github.com/rust-lang/rust-clippy/pull/9860)
+* Clippy will now avoid Cargo's cache, if `Cargo.toml` or `clippy.toml` have changed
+  [#9707](https://github.com/rust-lang/rust-clippy/pull/9707)
+* [`uninlined_format_args`]: Added a new config `allow-mixed-uninlined-format-args` to allow the
+  lint, if only some arguments can be inlined
+  [#9865](https://github.com/rust-lang/rust-clippy/pull/9865)
+* [`needless_lifetimes`]: Now provides suggests for individual lifetimes
+  [#9743](https://github.com/rust-lang/rust-clippy/pull/9743)
+* [`needless_collect`]: Now detects needless `is_empty` and `contains` calls
+  [#8744](https://github.com/rust-lang/rust-clippy/pull/8744)
+* [`blanket_clippy_restriction_lints`]: Now lints, if `clippy::restriction` is enabled via the
+  command line arguments
+  [#9755](https://github.com/rust-lang/rust-clippy/pull/9755)
+* [`mutable_key_type`]: Now has the `ignore-interior-mutability` configuration, to add types which
+  should be ignored by the lint
+  [#9692](https://github.com/rust-lang/rust-clippy/pull/9692)
+* [`uninlined_format_args`]: Now works for multiline `format!` expressions
+  [#9945](https://github.com/rust-lang/rust-clippy/pull/9945)
+* [`cognitive_complexity`]: Now works for async functions
+  [#9828](https://github.com/rust-lang/rust-clippy/pull/9828)
+  [#9836](https://github.com/rust-lang/rust-clippy/pull/9836)
+* [`vec_box`]: Now avoids an off-by-one error when using the `vec-box-size-threshold` configuration
+  [#9848](https://github.com/rust-lang/rust-clippy/pull/9848)
+* [`never_loop`]: Now correctly handles breaks in nested labeled blocks
+  [#9858](https://github.com/rust-lang/rust-clippy/pull/9858)
+  [#9837](https://github.com/rust-lang/rust-clippy/pull/9837)
+* [`disallowed_methods`], [`disallowed_types`], [`disallowed_macros`]: Now correctly resolve
+  paths, if a crate is used multiple times with different versions
+  [#9800](https://github.com/rust-lang/rust-clippy/pull/9800)
+* [`disallowed_methods`]: Can now be used for local methods
+  [#9800](https://github.com/rust-lang/rust-clippy/pull/9800)
+* [`print_stdout`], [`print_stderr`]: Can now be enabled in test with the `allow-print-in-tests`
+  config value
+  [#9797](https://github.com/rust-lang/rust-clippy/pull/9797)
+* [`from_raw_with_void_ptr`]: Now works for `Rc`, `Arc`, `alloc::rc::Weak` and
+  `alloc::sync::Weak` types.
+  [#9700](https://github.com/rust-lang/rust-clippy/pull/9700)
+* [`needless_borrowed_reference`]: Now works for struct and tuple patterns with wildcards
+  [#9855](https://github.com/rust-lang/rust-clippy/pull/9855)
+* [`or_fun_call`]: Now supports `map_or` methods
+  [#9689](https://github.com/rust-lang/rust-clippy/pull/9689)
+* [`unwrap_used`], [`expect_used`]: No longer lints in test code
+  [#9686](https://github.com/rust-lang/rust-clippy/pull/9686)
+* [`fn_params_excessive_bools`]: Is now emitted with the lint level at the linted function
+  [#9698](https://github.com/rust-lang/rust-clippy/pull/9698)
+
+### False Positive Fixes
+
+* [`new_ret_no_self`]: No longer lints when `impl Trait<Self>` is returned
+  [#9733](https://github.com/rust-lang/rust-clippy/pull/9733)
+* [`unnecessary_lazy_evaluations`]: No longer lints, if the type has a significant drop
+  [#9750](https://github.com/rust-lang/rust-clippy/pull/9750)
+* [`option_if_let_else`]: No longer lints, if any arm has guard
+  [#9747](https://github.com/rust-lang/rust-clippy/pull/9747)
+* [`explicit_auto_deref`]: No longer lints, if the target type is a projection with generic
+  arguments
+  [#9813](https://github.com/rust-lang/rust-clippy/pull/9813)
+* [`unnecessary_to_owned`]: No longer lints, if the suggestion effects types
+  [#9796](https://github.com/rust-lang/rust-clippy/pull/9796)
+* [`needless_borrow`]: No longer lints, if the suggestion is affected by `Deref`
+  [#9674](https://github.com/rust-lang/rust-clippy/pull/9674)
+* [`unused_unit`]: No longer lints, if lifetimes are bound to the return type
+  [#9849](https://github.com/rust-lang/rust-clippy/pull/9849)
+* [`mut_mut`]: No longer lints cases with unsized mutable references
+  [#9835](https://github.com/rust-lang/rust-clippy/pull/9835)
+* [`bool_to_int_with_if`]: No longer lints in const context
+  [#9738](https://github.com/rust-lang/rust-clippy/pull/9738)
+* [`use_self`]: No longer lints in macros
+  [#9704](https://github.com/rust-lang/rust-clippy/pull/9704)
+* [`unnecessary_operation`]: No longer lints, if multiple macros are involved
+  [#9981](https://github.com/rust-lang/rust-clippy/pull/9981)
+* [`allow_attributes_without_reason`]: No longer lints inside external macros
+  [#9630](https://github.com/rust-lang/rust-clippy/pull/9630)
+* [`question_mark`]: No longer lints for `if let Err()` with an `else` branch
+  [#9722](https://github.com/rust-lang/rust-clippy/pull/9722)
+* [`unnecessary_cast`]: No longer lints if the identifier and cast originate from different macros
+  [#9980](https://github.com/rust-lang/rust-clippy/pull/9980)
+* [`arithmetic_side_effects`]: Now detects operations with associated constants
+  [#9592](https://github.com/rust-lang/rust-clippy/pull/9592)
+* [`explicit_auto_deref`]: No longer lints, if the initial value is not a reference or reference
+  receiver
+  [#9997](https://github.com/rust-lang/rust-clippy/pull/9997)
+* [`module_name_repetitions`], [`single_component_path_imports`]: Now handle `#[allow]`
+  attributes correctly
+  [#9879](https://github.com/rust-lang/rust-clippy/pull/9879)
+* [`bool_to_int_with_if`]: No longer lints `if let` statements
+  [#9714](https://github.com/rust-lang/rust-clippy/pull/9714)
+* [`needless_borrow`]: No longer lints, `if`-`else`-statements that require the borrow
+  [#9791](https://github.com/rust-lang/rust-clippy/pull/9791)
+* [`needless_borrow`]: No longer lints borrows, if moves were illegal
+  [#9711](https://github.com/rust-lang/rust-clippy/pull/9711)
+* [`manual_swap`]: No longer lints in const context
+  [#9871](https://github.com/rust-lang/rust-clippy/pull/9871)
+
+### Suggestion Fixes/Improvements
+
+* [`missing_safety_doc`], [`missing_errors_doc`], [`missing_panics_doc`]: No longer show the
+  entire item in the lint emission.
+  [#9772](https://github.com/rust-lang/rust-clippy/pull/9772)
+* [`needless_lifetimes`]: Only suggests `'_` when it's applicable
+  [#9743](https://github.com/rust-lang/rust-clippy/pull/9743)
+* [`use_self`]: Now suggests full paths correctly
+  [#9726](https://github.com/rust-lang/rust-clippy/pull/9726)
+* [`redundant_closure_call`]: Now correctly deals with macros during suggestion creation
+  [#9987](https://github.com/rust-lang/rust-clippy/pull/9987)
+* [`unnecessary_cast`]: Suggestions now correctly deal with references
+  [#9996](https://github.com/rust-lang/rust-clippy/pull/9996)
+* [`unnecessary_join`]: Suggestions now correctly use [turbofish] operators
+  [#9779](https://github.com/rust-lang/rust-clippy/pull/9779)
+* [`equatable_if_let`]: Can now suggest `matches!` replacements
+  [#9368](https://github.com/rust-lang/rust-clippy/pull/9368)
+* [`string_extend_chars`]: Suggestions now correctly work for `str` slices
+  [#9741](https://github.com/rust-lang/rust-clippy/pull/9741)
+* [`redundant_closure_for_method_calls`]: Suggestions now include angle brackets and generic
+  arguments if needed
+  [#9745](https://github.com/rust-lang/rust-clippy/pull/9745)
+* [`manual_let_else`]: Suggestions no longer expand macro calls
+  [#9943](https://github.com/rust-lang/rust-clippy/pull/9943)
+* [`infallible_destructuring_match`]: Suggestions now preserve references
+  [#9850](https://github.com/rust-lang/rust-clippy/pull/9850)
+* [`result_large_err`]: The error now shows the largest enum variant
+  [#9662](https://github.com/rust-lang/rust-clippy/pull/9662)
+* [`needless_return`]: Suggestions are now formatted better
+  [#9967](https://github.com/rust-lang/rust-clippy/pull/9967)
+* [`unused_rounding`]: The suggestion now preserves the original float literal notation
+  [#9870](https://github.com/rust-lang/rust-clippy/pull/9870)
+
+[turbofish]: https://turbo.fish/::%3CClippy%3E
+
+### ICE Fixes
+
+* [`result_large_err`]: Fixed ICE for empty enums
+  [#10007](https://github.com/rust-lang/rust-clippy/pull/10007)
+* [`redundant_allocation`]: Fixed ICE for types with bounded variables
+  [#9773](https://github.com/rust-lang/rust-clippy/pull/9773)
+* [`unused_rounding`]: Fixed ICE, if `_` was used as a separator
+  [#10001](https://github.com/rust-lang/rust-clippy/pull/10001)
 
 ## Rust 1.66
 
-Current stable, released 2022-12-15
+Released 2022-12-15
 
 [b52fb523...4f142aa1](https://github.com/rust-lang/rust-clippy/compare/b52fb523...4f142aa1)
 
@@ -166,6 +359,7 @@ Current stable, released 2022-12-15
 
 * [`unnecessary_to_owned`]: Avoid ICEs in favor of false negatives if information is missing
   [#9505](https://github.com/rust-lang/rust-clippy/pull/9505)
+  [#10027](https://github.com/rust-lang/rust-clippy/pull/10027)
 * [`manual_range_contains`]: No longer ICEs on values behind references
   [#9627](https://github.com/rust-lang/rust-clippy/pull/9627)
 * [`needless_pass_by_value`]: No longer ICEs on unsized `dyn Fn` arguments
@@ -4383,6 +4577,7 @@ Released 2018-09-13
 [`multi_assignments`]: https://rust-lang.github.io/rust-clippy/master/index.html#multi_assignments
 [`multiple_crate_versions`]: https://rust-lang.github.io/rust-clippy/master/index.html#multiple_crate_versions
 [`multiple_inherent_impl`]: https://rust-lang.github.io/rust-clippy/master/index.html#multiple_inherent_impl
+[`multiple_unsafe_ops_per_block`]: https://rust-lang.github.io/rust-clippy/master/index.html#multiple_unsafe_ops_per_block
 [`must_use_candidate`]: https://rust-lang.github.io/rust-clippy/master/index.html#must_use_candidate
 [`must_use_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#must_use_unit
 [`mut_from_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_from_ref
diff --git a/src/tools/clippy/Cargo.toml b/src/tools/clippy/Cargo.toml
index f8cb4b7219c..2cfb47dd758 100644
--- a/src/tools/clippy/Cargo.toml
+++ b/src/tools/clippy/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy"
-version = "0.1.68"
+version = "0.1.69"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"
diff --git a/src/tools/clippy/README.md b/src/tools/clippy/README.md
index 81254ba8b8b..ab44db69483 100644
--- a/src/tools/clippy/README.md
+++ b/src/tools/clippy/README.md
@@ -194,11 +194,21 @@ value` mapping e.g.
 ```toml
 avoid-breaking-exported-api = false
 disallowed-names = ["toto", "tata", "titi"]
-cognitive-complexity-threshold = 30
 ```
 
-See the [list of configurable lints](https://rust-lang.github.io/rust-clippy/master/index.html#Configuration),
-the lint descriptions contain the names and meanings of these configuration variables.
+The [table of configurations](https://doc.rust-lang.org/nightly/clippy/lint_configuration.html)
+contains all config values, their default, and a list of lints they affect.
+Each [configurable lint](https://rust-lang.github.io/rust-clippy/master/index.html#Configuration)
+, also contains information about these values.
+
+For configurations that are a list type with default values such as
+[disallowed-names](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_names),
+you can use the unique value `".."` to extend the default values instead of replacing them.
+
+```toml
+# default of disallowed-names is ["foo", "baz", "quux"]
+disallowed-names = ["bar", ".."] # -> ["bar", "foo", "baz", "quux"]
+```
 
 > **Note**
 >
diff --git a/src/tools/clippy/book/src/SUMMARY.md b/src/tools/clippy/book/src/SUMMARY.md
index 1f0b8db28a1..0649f7a631d 100644
--- a/src/tools/clippy/book/src/SUMMARY.md
+++ b/src/tools/clippy/book/src/SUMMARY.md
@@ -5,6 +5,7 @@
 - [Installation](installation.md)
 - [Usage](usage.md)
 - [Configuration](configuration.md)
+    - [Lint Configuration](lint_configuration.md)
 - [Clippy's Lints](lints.md)
 - [Continuous Integration](continuous_integration/README.md)
     - [GitHub Actions](continuous_integration/github_actions.md)
diff --git a/src/tools/clippy/book/src/configuration.md b/src/tools/clippy/book/src/configuration.md
index 430ff8b739a..87f4a697af9 100644
--- a/src/tools/clippy/book/src/configuration.md
+++ b/src/tools/clippy/book/src/configuration.md
@@ -8,11 +8,21 @@ basic `variable = value` mapping eg.
 ```toml
 avoid-breaking-exported-api = false
 disallowed-names = ["toto", "tata", "titi"]
-cognitive-complexity-threshold = 30
 ```
 
-See the [list of configurable lints](https://rust-lang.github.io/rust-clippy/master/index.html#Configuration),
-the lint descriptions contain the names and meanings of these configuration variables.
+The [table of configurations](./lint_configuration.md)
+contains all config values, their default, and a list of lints they affect.
+Each [configurable lint](https://rust-lang.github.io/rust-clippy/master/index.html#Configuration)
+, also contains information about these values.
+
+For configurations that are a list type with default values such as
+[disallowed-names](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_names),
+you can use the unique value `".."` to extend the default values instead of replacing them.
+
+```toml
+# default of disallowed-names is ["foo", "baz", "quux"]
+disallowed-names = ["bar", ".."] # -> ["bar", "foo", "baz", "quux"]
+```
 
 To deactivate the "for further information visit *lint-link*" message you can define the `CLIPPY_DISABLE_DOCS_LINKS`
 environment variable.
diff --git a/src/tools/clippy/book/src/development/adding_lints.md b/src/tools/clippy/book/src/development/adding_lints.md
index 8b4eee8c9d9..f57dc627dce 100644
--- a/src/tools/clippy/book/src/development/adding_lints.md
+++ b/src/tools/clippy/book/src/development/adding_lints.md
@@ -146,7 +146,8 @@ For cargo lints, the process of testing differs in that we are interested in the
 manifest.
 
 If our new lint is named e.g. `foo_categories`, after running `cargo dev
-new_lint` we will find by default two new crates, each with its manifest file:
+new_lint --name=foo_categories --type=cargo --category=cargo` we will find by
+default two new crates, each with its manifest file:
 
 * `tests/ui-cargo/foo_categories/fail/Cargo.toml`: this file should cause the
   new lint to raise an error.
@@ -699,6 +700,10 @@ for some users. Adding a configuration is done in the following steps:
        `clippy.toml` file with the configuration value and a rust file that
        should be linted by Clippy. The test can otherwise be written as usual.
 
+5. Update [Lint Configuration](../lint_configuration.md)
+
+   Run `cargo collect-metadata` to generate documentation changes for the book.
+
 [`clippy_lints::utils::conf`]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_lints/src/utils/conf.rs
 [`clippy_lints` lib file]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_lints/src/lib.rs
 [`tests/ui`]: https://github.com/rust-lang/rust-clippy/blob/master/tests/ui
diff --git a/src/tools/clippy/book/src/development/infrastructure/book.md b/src/tools/clippy/book/src/development/infrastructure/book.md
index a4874219185..dbd624ecd73 100644
--- a/src/tools/clippy/book/src/development/infrastructure/book.md
+++ b/src/tools/clippy/book/src/development/infrastructure/book.md
@@ -3,15 +3,15 @@
 This document explains how to make additions and changes to the Clippy book, the
 guide to Clippy that you're reading right now. The Clippy book is formatted with
 [Markdown](https://www.markdownguide.org) and generated by
-[mdbook](https://github.com/rust-lang/mdBook).
+[mdBook](https://github.com/rust-lang/mdBook).
 
-- [Get mdbook](#get-mdbook)
+- [Get mdBook](#get-mdbook)
 - [Make changes](#make-changes)
 
-## Get mdbook
+## Get mdBook
 
 While not strictly necessary since the book source is simply Markdown text
-files, having mdbook locally will allow you to build, test and serve the book
+files, having mdBook locally will allow you to build, test and serve the book
 locally to view changes before you commit them to the repository. You likely
 already have `cargo` installed, so the easiest option is to simply:
 
@@ -19,7 +19,7 @@ already have `cargo` installed, so the easiest option is to simply:
 cargo install mdbook
 ```
 
-See the mdbook [installation](https://github.com/rust-lang/mdBook#installation)
+See the mdBook [installation](https://github.com/rust-lang/mdBook#installation)
 instructions for other options.
 
 ## Make changes
@@ -27,7 +27,7 @@ instructions for other options.
 The book's
 [src](https://github.com/rust-lang/rust-clippy/tree/master/book/src)
 directory contains all of the markdown files used to generate the book. If you
-want to see your changes in real time, you can use the mdbook `serve` command to
+want to see your changes in real time, you can use the mdBook `serve` command to
 run a web server locally that will automatically update changes as they are
 made. From the top level of your `rust-clippy` directory:
 
@@ -38,5 +38,5 @@ mdbook serve book --open
 Then navigate to `http://localhost:3000` to see the generated book. While the
 server is running, changes you make will automatically be updated.
 
-For more information, see the mdbook
+For more information, see the mdBook
 [guide](https://rust-lang.github.io/mdBook/).
diff --git a/src/tools/clippy/book/src/development/infrastructure/changelog_update.md b/src/tools/clippy/book/src/development/infrastructure/changelog_update.md
index 80a47affe30..d1ac7237b5e 100644
--- a/src/tools/clippy/book/src/development/infrastructure/changelog_update.md
+++ b/src/tools/clippy/book/src/development/infrastructure/changelog_update.md
@@ -95,11 +95,23 @@ As section headers, we use:
 Please also be sure to update the Beta/Unreleased sections at the top with the
 relevant commit ranges.
 
-If you have the time, it would be appreciated if you double-check, that the
-`#[clippy::version]` attributes for the added lints contains the correct version.
+#### 3.1 Include `beta-accepted` PRs
+
+Look for the [`beta-accepted`] label and make sure to also include the PRs with
+that label in the changelog. If you can, remove the `beta-accepted` labels
+**after** the changelog PR was merged.
+
+> _Note:_ Some of those PRs might even got backported to the previous `beta`.
+> Those have to be included in the changelog of the _previous_ release.
+
+### 4. Update `clippy::version` attributes
+
+Next, make sure to check that the `#[clippy::version]` attributes for the added
+lints contain the correct version.
 
 [changelog]: https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md
 [forge]: https://forge.rust-lang.org/
 [rust_master_tools]: https://github.com/rust-lang/rust/tree/master/src/tools/clippy
 [rust_beta_tools]: https://github.com/rust-lang/rust/tree/beta/src/tools/clippy
 [rust_stable_tools]: https://github.com/rust-lang/rust/releases
+[`beta-accepted`]: https://github.com/rust-lang/rust-clippy/issues?q=label%3Abeta-accepted+
diff --git a/src/tools/clippy/book/src/lint_configuration.md b/src/tools/clippy/book/src/lint_configuration.md
new file mode 100644
index 00000000000..f79dbb50ff4
--- /dev/null
+++ b/src/tools/clippy/book/src/lint_configuration.md
@@ -0,0 +1,523 @@
+<!--
+This file is generated by `cargo collect-metadata`.
+Please use that command to update the file and do not edit it by hand.
+-->
+
+## Lint Configuration Options
+| <div style="width:290px">Option</div> | Default Value |
+|--|--|
+| [arithmetic-side-effects-allowed](#arithmetic-side-effects-allowed) | `{}` |
+| [arithmetic-side-effects-allowed-binary](#arithmetic-side-effects-allowed-binary) | `[]` |
+| [arithmetic-side-effects-allowed-unary](#arithmetic-side-effects-allowed-unary) | `{}` |
+| [avoid-breaking-exported-api](#avoid-breaking-exported-api) | `true` |
+| [msrv](#msrv) | `None` |
+| [cognitive-complexity-threshold](#cognitive-complexity-threshold) | `25` |
+| [disallowed-names](#disallowed-names) | `["foo", "baz", "quux"]` |
+| [doc-valid-idents](#doc-valid-idents) | `["KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "DirectX", "ECMAScript", "GPLv2", "GPLv3", "GitHub", "GitLab", "IPv4", "IPv6", "ClojureScript", "CoffeeScript", "JavaScript", "PureScript", "TypeScript", "NaN", "NaNs", "OAuth", "GraphQL", "OCaml", "OpenGL", "OpenMP", "OpenSSH", "OpenSSL", "OpenStreetMap", "OpenDNS", "WebGL", "TensorFlow", "TrueType", "iOS", "macOS", "FreeBSD", "TeX", "LaTeX", "BibTeX", "BibLaTeX", "MinGW", "CamelCase"]` |
+| [too-many-arguments-threshold](#too-many-arguments-threshold) | `7` |
+| [type-complexity-threshold](#type-complexity-threshold) | `250` |
+| [single-char-binding-names-threshold](#single-char-binding-names-threshold) | `4` |
+| [too-large-for-stack](#too-large-for-stack) | `200` |
+| [enum-variant-name-threshold](#enum-variant-name-threshold) | `3` |
+| [enum-variant-size-threshold](#enum-variant-size-threshold) | `200` |
+| [verbose-bit-mask-threshold](#verbose-bit-mask-threshold) | `1` |
+| [literal-representation-threshold](#literal-representation-threshold) | `16384` |
+| [trivial-copy-size-limit](#trivial-copy-size-limit) | `None` |
+| [pass-by-value-size-limit](#pass-by-value-size-limit) | `256` |
+| [too-many-lines-threshold](#too-many-lines-threshold) | `100` |
+| [array-size-threshold](#array-size-threshold) | `512000` |
+| [vec-box-size-threshold](#vec-box-size-threshold) | `4096` |
+| [max-trait-bounds](#max-trait-bounds) | `3` |
+| [max-struct-bools](#max-struct-bools) | `3` |
+| [max-fn-params-bools](#max-fn-params-bools) | `3` |
+| [warn-on-all-wildcard-imports](#warn-on-all-wildcard-imports) | `false` |
+| [disallowed-macros](#disallowed-macros) | `[]` |
+| [disallowed-methods](#disallowed-methods) | `[]` |
+| [disallowed-types](#disallowed-types) | `[]` |
+| [unreadable-literal-lint-fractions](#unreadable-literal-lint-fractions) | `true` |
+| [upper-case-acronyms-aggressive](#upper-case-acronyms-aggressive) | `false` |
+| [matches-for-let-else](#matches-for-let-else) | `WellKnownTypes` |
+| [cargo-ignore-publish](#cargo-ignore-publish) | `false` |
+| [standard-macro-braces](#standard-macro-braces) | `[]` |
+| [enforced-import-renames](#enforced-import-renames) | `[]` |
+| [allowed-scripts](#allowed-scripts) | `["Latin"]` |
+| [enable-raw-pointer-heuristic-for-send](#enable-raw-pointer-heuristic-for-send) | `true` |
+| [max-suggested-slice-pattern-length](#max-suggested-slice-pattern-length) | `3` |
+| [max-include-file-size](#max-include-file-size) | `1000000` |
+| [allow-expect-in-tests](#allow-expect-in-tests) | `false` |
+| [allow-unwrap-in-tests](#allow-unwrap-in-tests) | `false` |
+| [allow-dbg-in-tests](#allow-dbg-in-tests) | `false` |
+| [allow-print-in-tests](#allow-print-in-tests) | `false` |
+| [large-error-threshold](#large-error-threshold) | `128` |
+| [ignore-interior-mutability](#ignore-interior-mutability) | `["bytes::Bytes"]` |
+| [allow-mixed-uninlined-format-args](#allow-mixed-uninlined-format-args) | `true` |
+| [suppress-restriction-lint-in-const](#suppress-restriction-lint-in-const) | `false` |
+
+### arithmetic-side-effects-allowed
+Suppress checking of the passed type names in all types of operations.
+
+If a specific operation is desired, consider using `arithmetic_side_effects_allowed_binary` or `arithmetic_side_effects_allowed_unary` instead.
+
+#### Example
+
+```toml
+arithmetic-side-effects-allowed = ["SomeType", "AnotherType"]
+```
+
+#### Noteworthy
+
+A type, say `SomeType`, listed in this configuration has the same behavior of
+`["SomeType" , "*"], ["*", "SomeType"]` in `arithmetic_side_effects_allowed_binary`.
+
+**Default Value:** `{}` (`rustc_data_structures::fx::FxHashSet<String>`)
+
+* [arithmetic_side_effects](https://rust-lang.github.io/rust-clippy/master/index.html#arithmetic_side_effects)
+
+
+### arithmetic-side-effects-allowed-binary
+Suppress checking of the passed type pair names in binary operations like addition or
+multiplication.
+
+Supports the "*" wildcard to indicate that a certain type won't trigger the lint regardless
+of the involved counterpart. For example, `["SomeType", "*"]` or `["*", "AnotherType"]`.
+
+Pairs are asymmetric, which means that `["SomeType", "AnotherType"]` is not the same as
+`["AnotherType", "SomeType"]`.
+
+#### Example
+
+```toml
+arithmetic-side-effects-allowed-binary = [["SomeType" , "f32"], ["AnotherType", "*"]]
+```
+
+**Default Value:** `[]` (`Vec<[String; 2]>`)
+
+* [arithmetic_side_effects](https://rust-lang.github.io/rust-clippy/master/index.html#arithmetic_side_effects)
+
+
+### arithmetic-side-effects-allowed-unary
+Suppress checking of the passed type names in unary operations like "negation" (`-`).
+
+#### Example
+
+```toml
+arithmetic-side-effects-allowed-unary = ["SomeType", "AnotherType"]
+```
+
+**Default Value:** `{}` (`rustc_data_structures::fx::FxHashSet<String>`)
+
+* [arithmetic_side_effects](https://rust-lang.github.io/rust-clippy/master/index.html#arithmetic_side_effects)
+
+
+### avoid-breaking-exported-api
+Suppress lints whenever the suggested change would cause breakage for other crates.
+
+**Default Value:** `true` (`bool`)
+
+* [enum_variant_names](https://rust-lang.github.io/rust-clippy/master/index.html#enum_variant_names)
+* [large_types_passed_by_value](https://rust-lang.github.io/rust-clippy/master/index.html#large_types_passed_by_value)
+* [trivially_copy_pass_by_ref](https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref)
+* [unnecessary_wraps](https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps)
+* [unused_self](https://rust-lang.github.io/rust-clippy/master/index.html#unused_self)
+* [upper_case_acronyms](https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms)
+* [wrong_self_convention](https://rust-lang.github.io/rust-clippy/master/index.html#wrong_self_convention)
+* [box_collection](https://rust-lang.github.io/rust-clippy/master/index.html#box_collection)
+* [redundant_allocation](https://rust-lang.github.io/rust-clippy/master/index.html#redundant_allocation)
+* [rc_buffer](https://rust-lang.github.io/rust-clippy/master/index.html#rc_buffer)
+* [vec_box](https://rust-lang.github.io/rust-clippy/master/index.html#vec_box)
+* [option_option](https://rust-lang.github.io/rust-clippy/master/index.html#option_option)
+* [linkedlist](https://rust-lang.github.io/rust-clippy/master/index.html#linkedlist)
+* [rc_mutex](https://rust-lang.github.io/rust-clippy/master/index.html#rc_mutex)
+
+
+### msrv
+The minimum rust version that the project supports
+
+**Default Value:** `None` (`Option<String>`)
+
+* [manual_split_once](https://rust-lang.github.io/rust-clippy/master/index.html#manual_split_once)
+* [manual_str_repeat](https://rust-lang.github.io/rust-clippy/master/index.html#manual_str_repeat)
+* [cloned_instead_of_copied](https://rust-lang.github.io/rust-clippy/master/index.html#cloned_instead_of_copied)
+* [redundant_field_names](https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names)
+* [redundant_static_lifetimes](https://rust-lang.github.io/rust-clippy/master/index.html#redundant_static_lifetimes)
+* [filter_map_next](https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_next)
+* [checked_conversions](https://rust-lang.github.io/rust-clippy/master/index.html#checked_conversions)
+* [manual_range_contains](https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains)
+* [use_self](https://rust-lang.github.io/rust-clippy/master/index.html#use_self)
+* [mem_replace_with_default](https://rust-lang.github.io/rust-clippy/master/index.html#mem_replace_with_default)
+* [manual_non_exhaustive](https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive)
+* [option_as_ref_deref](https://rust-lang.github.io/rust-clippy/master/index.html#option_as_ref_deref)
+* [map_unwrap_or](https://rust-lang.github.io/rust-clippy/master/index.html#map_unwrap_or)
+* [match_like_matches_macro](https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro)
+* [manual_strip](https://rust-lang.github.io/rust-clippy/master/index.html#manual_strip)
+* [missing_const_for_fn](https://rust-lang.github.io/rust-clippy/master/index.html#missing_const_for_fn)
+* [unnested_or_patterns](https://rust-lang.github.io/rust-clippy/master/index.html#unnested_or_patterns)
+* [from_over_into](https://rust-lang.github.io/rust-clippy/master/index.html#from_over_into)
+* [ptr_as_ptr](https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr)
+* [if_then_some_else_none](https://rust-lang.github.io/rust-clippy/master/index.html#if_then_some_else_none)
+* [approx_constant](https://rust-lang.github.io/rust-clippy/master/index.html#approx_constant)
+* [deprecated_cfg_attr](https://rust-lang.github.io/rust-clippy/master/index.html#deprecated_cfg_attr)
+* [index_refutable_slice](https://rust-lang.github.io/rust-clippy/master/index.html#index_refutable_slice)
+* [map_clone](https://rust-lang.github.io/rust-clippy/master/index.html#map_clone)
+* [borrow_as_ptr](https://rust-lang.github.io/rust-clippy/master/index.html#borrow_as_ptr)
+* [manual_bits](https://rust-lang.github.io/rust-clippy/master/index.html#manual_bits)
+* [err_expect](https://rust-lang.github.io/rust-clippy/master/index.html#err_expect)
+* [cast_abs_to_unsigned](https://rust-lang.github.io/rust-clippy/master/index.html#cast_abs_to_unsigned)
+* [uninlined_format_args](https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args)
+* [manual_clamp](https://rust-lang.github.io/rust-clippy/master/index.html#manual_clamp)
+* [manual_let_else](https://rust-lang.github.io/rust-clippy/master/index.html#manual_let_else)
+* [unchecked_duration_subtraction](https://rust-lang.github.io/rust-clippy/master/index.html#unchecked_duration_subtraction)
+
+
+### cognitive-complexity-threshold
+The maximum cognitive complexity a function can have
+
+**Default Value:** `25` (`u64`)
+
+* [cognitive_complexity](https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity)
+
+
+### disallowed-names
+The list of disallowed names to lint about. NB: `bar` is not here since it has legitimate uses. The value
+`".."` can be used as part of the list to indicate, that the configured values should be appended to the
+default configuration of Clippy. By default any configuration will replace the default value.
+
+**Default Value:** `["foo", "baz", "quux"]` (`Vec<String>`)
+
+* [disallowed_names](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_names)
+
+
+### doc-valid-idents
+The list of words this lint should not consider as identifiers needing ticks. The value
+`".."` can be used as part of the list to indicate, that the configured values should be appended to the
+default configuration of Clippy. By default any configuraction will replace the default value. For example:
+* `doc-valid-idents = ["ClipPy"]` would replace the default list with `["ClipPy"]`.
+* `doc-valid-idents = ["ClipPy", ".."]` would append `ClipPy` to the default list.
+
+Default list:
+
+**Default Value:** `["KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "DirectX", "ECMAScript", "GPLv2", "GPLv3", "GitHub", "GitLab", "IPv4", "IPv6", "ClojureScript", "CoffeeScript", "JavaScript", "PureScript", "TypeScript", "NaN", "NaNs", "OAuth", "GraphQL", "OCaml", "OpenGL", "OpenMP", "OpenSSH", "OpenSSL", "OpenStreetMap", "OpenDNS", "WebGL", "TensorFlow", "TrueType", "iOS", "macOS", "FreeBSD", "TeX", "LaTeX", "BibTeX", "BibLaTeX", "MinGW", "CamelCase"]` (`Vec<String>`)
+
+* [doc_markdown](https://rust-lang.github.io/rust-clippy/master/index.html#doc_markdown)
+
+
+### too-many-arguments-threshold
+The maximum number of argument a function or method can have
+
+**Default Value:** `7` (`u64`)
+
+* [too_many_arguments](https://rust-lang.github.io/rust-clippy/master/index.html#too_many_arguments)
+
+
+### type-complexity-threshold
+The maximum complexity a type can have
+
+**Default Value:** `250` (`u64`)
+
+* [type_complexity](https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity)
+
+
+### single-char-binding-names-threshold
+The maximum number of single char bindings a scope may have
+
+**Default Value:** `4` (`u64`)
+
+* [many_single_char_names](https://rust-lang.github.io/rust-clippy/master/index.html#many_single_char_names)
+
+
+### too-large-for-stack
+The maximum size of objects (in bytes) that will be linted. Larger objects are ok on the heap
+
+**Default Value:** `200` (`u64`)
+
+* [boxed_local](https://rust-lang.github.io/rust-clippy/master/index.html#boxed_local)
+* [useless_vec](https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec)
+
+
+### enum-variant-name-threshold
+The minimum number of enum variants for the lints about variant names to trigger
+
+**Default Value:** `3` (`u64`)
+
+* [enum_variant_names](https://rust-lang.github.io/rust-clippy/master/index.html#enum_variant_names)
+
+
+### enum-variant-size-threshold
+The maximum size of an enum's variant to avoid box suggestion
+
+**Default Value:** `200` (`u64`)
+
+* [large_enum_variant](https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant)
+
+
+### verbose-bit-mask-threshold
+The maximum allowed size of a bit mask before suggesting to use 'trailing_zeros'
+
+**Default Value:** `1` (`u64`)
+
+* [verbose_bit_mask](https://rust-lang.github.io/rust-clippy/master/index.html#verbose_bit_mask)
+
+
+### literal-representation-threshold
+The lower bound for linting decimal literals
+
+**Default Value:** `16384` (`u64`)
+
+* [decimal_literal_representation](https://rust-lang.github.io/rust-clippy/master/index.html#decimal_literal_representation)
+
+
+### trivial-copy-size-limit
+The maximum size (in bytes) to consider a `Copy` type for passing by value instead of by reference.
+
+**Default Value:** `None` (`Option<u64>`)
+
+* [trivially_copy_pass_by_ref](https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref)
+
+
+### pass-by-value-size-limit
+The minimum size (in bytes) to consider a type for passing by reference instead of by value.
+
+**Default Value:** `256` (`u64`)
+
+* [large_type_pass_by_move](https://rust-lang.github.io/rust-clippy/master/index.html#large_type_pass_by_move)
+
+
+### too-many-lines-threshold
+The maximum number of lines a function or method can have
+
+**Default Value:** `100` (`u64`)
+
+* [too_many_lines](https://rust-lang.github.io/rust-clippy/master/index.html#too_many_lines)
+
+
+### array-size-threshold
+The maximum allowed size for arrays on the stack
+
+**Default Value:** `512000` (`u128`)
+
+* [large_stack_arrays](https://rust-lang.github.io/rust-clippy/master/index.html#large_stack_arrays)
+* [large_const_arrays](https://rust-lang.github.io/rust-clippy/master/index.html#large_const_arrays)
+
+
+### vec-box-size-threshold
+The size of the boxed type in bytes, where boxing in a `Vec` is allowed
+
+**Default Value:** `4096` (`u64`)
+
+* [vec_box](https://rust-lang.github.io/rust-clippy/master/index.html#vec_box)
+
+
+### max-trait-bounds
+The maximum number of bounds a trait can have to be linted
+
+**Default Value:** `3` (`u64`)
+
+* [type_repetition_in_bounds](https://rust-lang.github.io/rust-clippy/master/index.html#type_repetition_in_bounds)
+
+
+### max-struct-bools
+The maximum number of bool fields a struct can have
+
+**Default Value:** `3` (`u64`)
+
+* [struct_excessive_bools](https://rust-lang.github.io/rust-clippy/master/index.html#struct_excessive_bools)
+
+
+### max-fn-params-bools
+The maximum number of bool parameters a function can have
+
+**Default Value:** `3` (`u64`)
+
+* [fn_params_excessive_bools](https://rust-lang.github.io/rust-clippy/master/index.html#fn_params_excessive_bools)
+
+
+### warn-on-all-wildcard-imports
+Whether to allow certain wildcard imports (prelude, super in tests).
+
+**Default Value:** `false` (`bool`)
+
+* [wildcard_imports](https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports)
+
+
+### disallowed-macros
+The list of disallowed macros, written as fully qualified paths.
+
+**Default Value:** `[]` (`Vec<crate::utils::conf::DisallowedPath>`)
+
+* [disallowed_macros](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_macros)
+
+
+### disallowed-methods
+The list of disallowed methods, written as fully qualified paths.
+
+**Default Value:** `[]` (`Vec<crate::utils::conf::DisallowedPath>`)
+
+* [disallowed_methods](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_methods)
+
+
+### disallowed-types
+The list of disallowed types, written as fully qualified paths.
+
+**Default Value:** `[]` (`Vec<crate::utils::conf::DisallowedPath>`)
+
+* [disallowed_types](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_types)
+
+
+### unreadable-literal-lint-fractions
+Should the fraction of a decimal be linted to include separators.
+
+**Default Value:** `true` (`bool`)
+
+* [unreadable_literal](https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal)
+
+
+### upper-case-acronyms-aggressive
+Enables verbose mode. Triggers if there is more than one uppercase char next to each other
+
+**Default Value:** `false` (`bool`)
+
+* [upper_case_acronyms](https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms)
+
+
+### matches-for-let-else
+Whether the matches should be considered by the lint, and whether there should
+be filtering for common types.
+
+**Default Value:** `WellKnownTypes` (`crate::manual_let_else::MatchLintBehaviour`)
+
+* [manual_let_else](https://rust-lang.github.io/rust-clippy/master/index.html#manual_let_else)
+
+
+### cargo-ignore-publish
+For internal testing only, ignores the current `publish` settings in the Cargo manifest.
+
+**Default Value:** `false` (`bool`)
+
+* [_cargo_common_metadata](https://rust-lang.github.io/rust-clippy/master/index.html#_cargo_common_metadata)
+
+
+### standard-macro-braces
+Enforce the named macros always use the braces specified.
+
+A `MacroMatcher` can be added like so `{ name = "macro_name", brace = "(" }`. If the macro
+is could be used with a full path two `MacroMatcher`s have to be added one with the full path
+`crate_name::macro_name` and one with just the macro name.
+
+**Default Value:** `[]` (`Vec<crate::nonstandard_macro_braces::MacroMatcher>`)
+
+* [nonstandard_macro_braces](https://rust-lang.github.io/rust-clippy/master/index.html#nonstandard_macro_braces)
+
+
+### enforced-import-renames
+The list of imports to always rename, a fully qualified path followed by the rename.
+
+**Default Value:** `[]` (`Vec<crate::utils::conf::Rename>`)
+
+* [missing_enforced_import_renames](https://rust-lang.github.io/rust-clippy/master/index.html#missing_enforced_import_renames)
+
+
+### allowed-scripts
+The list of unicode scripts allowed to be used in the scope.
+
+**Default Value:** `["Latin"]` (`Vec<String>`)
+
+* [disallowed_script_idents](https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_script_idents)
+
+
+### enable-raw-pointer-heuristic-for-send
+Whether to apply the raw pointer heuristic to determine if a type is `Send`.
+
+**Default Value:** `true` (`bool`)
+
+* [non_send_fields_in_send_ty](https://rust-lang.github.io/rust-clippy/master/index.html#non_send_fields_in_send_ty)
+
+
+### max-suggested-slice-pattern-length
+When Clippy suggests using a slice pattern, this is the maximum number of elements allowed in
+the slice pattern that is suggested. If more elements would be necessary, the lint is suppressed.
+For example, `[_, _, _, e, ..]` is a slice pattern with 4 elements.
+
+**Default Value:** `3` (`u64`)
+
+* [index_refutable_slice](https://rust-lang.github.io/rust-clippy/master/index.html#index_refutable_slice)
+
+
+### max-include-file-size
+The maximum size of a file included via `include_bytes!()` or `include_str!()`, in bytes
+
+**Default Value:** `1000000` (`u64`)
+
+* [large_include_file](https://rust-lang.github.io/rust-clippy/master/index.html#large_include_file)
+
+
+### allow-expect-in-tests
+Whether `expect` should be allowed within `#[cfg(test)]`
+
+**Default Value:** `false` (`bool`)
+
+* [expect_used](https://rust-lang.github.io/rust-clippy/master/index.html#expect_used)
+
+
+### allow-unwrap-in-tests
+Whether `unwrap` should be allowed in test cfg
+
+**Default Value:** `false` (`bool`)
+
+* [unwrap_used](https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_used)
+
+
+### allow-dbg-in-tests
+Whether `dbg!` should be allowed in test functions
+
+**Default Value:** `false` (`bool`)
+
+* [dbg_macro](https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro)
+
+
+### allow-print-in-tests
+Whether print macros (ex. `println!`) should be allowed in test functions
+
+**Default Value:** `false` (`bool`)
+
+* [print_stdout](https://rust-lang.github.io/rust-clippy/master/index.html#print_stdout)
+* [print_stderr](https://rust-lang.github.io/rust-clippy/master/index.html#print_stderr)
+
+
+### large-error-threshold
+The maximum size of the `Err`-variant in a `Result` returned from a function
+
+**Default Value:** `128` (`u64`)
+
+* [result_large_err](https://rust-lang.github.io/rust-clippy/master/index.html#result_large_err)
+
+
+### ignore-interior-mutability
+A list of paths to types that should be treated like `Arc`, i.e. ignored but
+for the generic parameters for determining interior mutability
+
+**Default Value:** `["bytes::Bytes"]` (`Vec<String>`)
+
+* [mutable_key](https://rust-lang.github.io/rust-clippy/master/index.html#mutable_key)
+
+
+### allow-mixed-uninlined-format-args
+Whether to allow mixed uninlined format args, e.g. `format!("{} {}", a, foo.bar)`
+
+**Default Value:** `true` (`bool`)
+
+* [uninlined_format_args](https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args)
+
+
+### suppress-restriction-lint-in-const
+In same
+cases the restructured operation might not be unavoidable, as the
+suggested counterparts are unavailable in constant code. This
+configuration will cause restriction lints to trigger even
+if no suggestion can be made.
+
+**Default Value:** `false` (`bool`)
+
+* [indexing_slicing](https://rust-lang.github.io/rust-clippy/master/index.html#indexing_slicing)
+
+
+
diff --git a/src/tools/clippy/clippy_lints/Cargo.toml b/src/tools/clippy/clippy_lints/Cargo.toml
index a9f69b1ba63..4c40483e3ec 100644
--- a/src/tools/clippy/clippy_lints/Cargo.toml
+++ b/src/tools/clippy/clippy_lints/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy_lints"
-version = "0.1.68"
+version = "0.1.69"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"
diff --git a/src/tools/clippy/clippy_lints/src/bool_assert_comparison.rs b/src/tools/clippy/clippy_lints/src/bool_assert_comparison.rs
index 82d368bb8bc..556fa579000 100644
--- a/src/tools/clippy/clippy_lints/src/bool_assert_comparison.rs
+++ b/src/tools/clippy/clippy_lints/src/bool_assert_comparison.rs
@@ -1,10 +1,11 @@
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::macros::{find_assert_eq_args, root_macro_call_first_node};
-use clippy_utils::{diagnostics::span_lint_and_sugg, ty::implements_trait};
+use clippy_utils::ty::{implements_trait, is_copy};
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, Lit};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::Ident;
 
@@ -43,9 +44,7 @@ fn is_bool_lit(e: &Expr<'_>) -> bool {
     ) && !e.span.from_expansion()
 }
 
-fn is_impl_not_trait_with_bool_out(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
-    let ty = cx.typeck_results().expr_ty(e);
-
+fn is_impl_not_trait_with_bool_out<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
     cx.tcx
         .lang_items()
         .not_trait()
@@ -77,31 +76,57 @@ impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
             return;
         }
         let Some ((a, b, _)) = find_assert_eq_args(cx, expr, macro_call.expn) else { return };
-        if !(is_bool_lit(a) ^ is_bool_lit(b)) {
+
+        let a_span = a.span.source_callsite();
+        let b_span = b.span.source_callsite();
+
+        let (lit_span, non_lit_expr) = match (is_bool_lit(a), is_bool_lit(b)) {
+            // assert_eq!(true, b)
+            //            ^^^^^^
+            (true, false) => (a_span.until(b_span), b),
+            // assert_eq!(a, true)
+            //             ^^^^^^
+            (false, true) => (b_span.with_lo(a_span.hi()), a),
             // If there are two boolean arguments, we definitely don't understand
             // what's going on, so better leave things as is...
             //
             // Or there is simply no boolean and then we can leave things as is!
-            return;
-        }
+            _ => return,
+        };
 
-        if !is_impl_not_trait_with_bool_out(cx, a) || !is_impl_not_trait_with_bool_out(cx, b) {
+        let non_lit_ty = cx.typeck_results().expr_ty(non_lit_expr);
+
+        if !is_impl_not_trait_with_bool_out(cx, non_lit_ty) {
             // At this point the expression which is not a boolean
             // literal does not implement Not trait with a bool output,
             // so we cannot suggest to rewrite our code
             return;
         }
 
+        if !is_copy(cx, non_lit_ty) {
+            // Only lint with types that are `Copy` because `assert!(x)` takes
+            // ownership of `x` whereas `assert_eq(x, true)` does not
+            return;
+        }
+
         let macro_name = macro_name.as_str();
         let non_eq_mac = &macro_name[..macro_name.len() - 3];
-        span_lint_and_sugg(
+        span_lint_and_then(
             cx,
             BOOL_ASSERT_COMPARISON,
             macro_call.span,
             &format!("used `{macro_name}!` with a literal bool"),
-            "replace it with",
-            format!("{non_eq_mac}!(..)"),
-            Applicability::MaybeIncorrect,
+            |diag| {
+                // assert_eq!(...)
+                // ^^^^^^^^^
+                let name_span = cx.sess().source_map().span_until_char(macro_call.span, '!');
+
+                diag.multipart_suggestion(
+                    format!("replace it with `{non_eq_mac}!(..)`"),
+                    vec![(name_span, non_eq_mac.to_string()), (lit_span, String::new())],
+                    Applicability::MachineApplicable,
+                );
+            },
         );
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/booleans.rs b/src/tools/clippy/clippy_lints/src/booleans.rs
index 939bdbcdc7c..e8106beec37 100644
--- a/src/tools/clippy/clippy_lints/src/booleans.rs
+++ b/src/tools/clippy/clippy_lints/src/booleans.rs
@@ -6,9 +6,10 @@ use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
-use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, UnOp};
+use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::sym;
 
@@ -82,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for NonminimalBool {
         _: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         _: Span,
-        _: HirId,
+        _: LocalDefId,
     ) {
         NonminimalBoolVisitor { cx }.visit_body(body);
     }
diff --git a/src/tools/clippy/clippy_lints/src/casts/as_ptr_cast_mut.rs b/src/tools/clippy/clippy_lints/src/casts/as_ptr_cast_mut.rs
index 9409f4844f5..1633ffd589c 100644
--- a/src/tools/clippy/clippy_lints/src/casts/as_ptr_cast_mut.rs
+++ b/src/tools/clippy/clippy_lints/src/casts/as_ptr_cast_mut.rs
@@ -17,7 +17,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
         && let ExprKind::MethodCall(method_name, receiver, [], _) = cast_expr.peel_blocks().kind
         && method_name.ident.name == rustc_span::sym::as_ptr
         && let Some(as_ptr_did) = cx.typeck_results().type_dependent_def_id(cast_expr.peel_blocks().hir_id)
-        && let as_ptr_sig = cx.tcx.fn_sig(as_ptr_did)
+        && let as_ptr_sig = cx.tcx.fn_sig(as_ptr_did).subst_identity()
         && let Some(first_param_ty) = as_ptr_sig.skip_binder().inputs().iter().next()
         && let ty::Ref(_, _, Mutability::Not) = first_param_ty.kind()
         && let Some(recv) = snippet_opt(cx, receiver.span)
diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs b/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs
index a6376484914..f3f8b8d8798 100644
--- a/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs
+++ b/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs
@@ -1,11 +1,14 @@
 use clippy_utils::consts::{constant, Constant};
-use clippy_utils::diagnostics::span_lint;
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
 use clippy_utils::expr_or_init;
+use clippy_utils::source::snippet;
 use clippy_utils::ty::{get_discriminant_value, is_isize_or_usize};
+use rustc_errors::{Applicability, SuggestionStyle};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, FloatTy, Ty};
+use rustc_span::Span;
 use rustc_target::abi::IntegerType;
 
 use super::{utils, CAST_ENUM_TRUNCATION, CAST_POSSIBLE_TRUNCATION};
@@ -74,7 +77,14 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b
     }
 }
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>) {
+pub(super) fn check(
+    cx: &LateContext<'_>,
+    expr: &Expr<'_>,
+    cast_expr: &Expr<'_>,
+    cast_from: Ty<'_>,
+    cast_to: Ty<'_>,
+    cast_to_span: Span,
+) {
     let msg = match (cast_from.kind(), cast_to.is_integral()) {
         (ty::Int(_) | ty::Uint(_), true) => {
             let from_nbits = apply_reductions(
@@ -139,7 +149,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                 );
                 return;
             }
-            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}",)
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}")
         },
 
         (ty::Float(_), true) => {
@@ -153,5 +163,19 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
         _ => return,
     };
 
-    span_lint(cx, CAST_POSSIBLE_TRUNCATION, expr.span, &msg);
+    let name_of_cast_from = snippet(cx, cast_expr.span, "..");
+    let cast_to_snip = snippet(cx, cast_to_span, "..");
+    let suggestion = format!("{cast_to_snip}::try_from({name_of_cast_from})");
+
+    span_lint_and_then(cx, CAST_POSSIBLE_TRUNCATION, expr.span, &msg, |diag| {
+        diag.help("if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...");
+        diag.span_suggestion_with_style(
+            expr.span,
+            "... or use `try_from` and handle the error accordingly",
+            suggestion,
+            Applicability::Unspecified,
+            // always show the suggestion in a separate line
+            SuggestionStyle::ShowAlways,
+        );
+    });
 }
diff --git a/src/tools/clippy/clippy_lints/src/casts/mod.rs b/src/tools/clippy/clippy_lints/src/casts/mod.rs
index 161e3a698e9..362f70d12d1 100644
--- a/src/tools/clippy/clippy_lints/src/casts/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/casts/mod.rs
@@ -80,7 +80,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for casts between numerical types that may
     /// truncate large values. This is expected behavior, so the cast is `Allow` by
-    /// default.
+    /// default. It suggests user either explicitly ignore the lint,
+    /// or use `try_from()` and handle the truncation, default, or panic explicitly.
     ///
     /// ### Why is this bad?
     /// In some problem domains, it is good practice to avoid
@@ -93,6 +94,21 @@ declare_clippy_lint! {
     ///     x as u8
     /// }
     /// ```
+    /// Use instead:
+    /// ```
+    /// fn as_u8(x: u64) -> u8 {
+    ///     if let Ok(x) = u8::try_from(x) {
+    ///         x
+    ///     } else {
+    ///         todo!();
+    ///     }
+    /// }
+    /// // Or
+    /// #[allow(clippy::cast_possible_truncation)]
+    /// fn as_u16(x: u64) -> u16 {
+    ///     x as u16
+    /// }
+    /// ```
     #[clippy::version = "pre 1.29.0"]
     pub CAST_POSSIBLE_TRUNCATION,
     pedantic,
@@ -712,7 +728,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts {
             fn_to_numeric_cast_with_truncation::check(cx, expr, cast_expr, cast_from, cast_to);
 
             if cast_to.is_numeric() && !in_external_macro(cx.sess(), expr.span) {
-                cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to);
+                cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to, cast_to_hir.span);
                 if cast_from.is_numeric() {
                     cast_possible_wrap::check(cx, expr, cast_from, cast_to);
                     cast_precision_loss::check(cx, expr, cast_from, cast_to);
diff --git a/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs b/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs
index 1c3a89a9782..e8531157e0f 100644
--- a/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs
+++ b/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs
@@ -8,9 +8,10 @@ use clippy_utils::{get_async_fn_body, is_async_fn, LimitStack};
 use core::ops::ControlFlow;
 use rustc_ast::ast::Attribute;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::{sym, BytePos};
 
@@ -140,9 +141,8 @@ impl<'tcx> LateLintPass<'tcx> for CognitiveComplexity {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
-        let def_id = cx.tcx.hir().local_def_id(hir_id);
         if !cx.tcx.has_attr(def_id.to_def_id(), sym::test) {
             let expr = if is_async_fn(kind) {
                 match get_async_fn_body(cx.tcx, body) {
diff --git a/src/tools/clippy/clippy_lints/src/declared_lints.rs b/src/tools/clippy/clippy_lints/src/declared_lints.rs
index 91ca73633f0..36a366fc974 100644
--- a/src/tools/clippy/clippy_lints/src/declared_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/declared_lints.rs
@@ -422,6 +422,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::module_style::MOD_MODULE_FILES_INFO,
     crate::module_style::SELF_NAMED_MODULE_FILES_INFO,
     crate::multi_assignments::MULTI_ASSIGNMENTS_INFO,
+    crate::multiple_unsafe_ops_per_block::MULTIPLE_UNSAFE_OPS_PER_BLOCK_INFO,
     crate::mut_key::MUTABLE_KEY_TYPE_INFO,
     crate::mut_mut::MUT_MUT_INFO,
     crate::mut_reference::UNNECESSARY_MUT_PASSED_INFO,
diff --git a/src/tools/clippy/clippy_lints/src/default_numeric_fallback.rs b/src/tools/clippy/clippy_lints/src/default_numeric_fallback.rs
index 03460689e19..f806ba238c7 100644
--- a/src/tools/clippy/clippy_lints/src/default_numeric_fallback.rs
+++ b/src/tools/clippy/clippy_lints/src/default_numeric_fallback.rs
@@ -141,7 +141,7 @@ impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
 
             ExprKind::MethodCall(_, receiver, args, _) => {
                 if let Some(def_id) = self.cx.typeck_results().type_dependent_def_id(expr.hir_id) {
-                    let fn_sig = self.cx.tcx.fn_sig(def_id).skip_binder();
+                    let fn_sig = self.cx.tcx.fn_sig(def_id).subst_identity().skip_binder();
                     for (expr, bound) in iter::zip(std::iter::once(*receiver).chain(args.iter()), fn_sig.inputs()) {
                         self.ty_bounds.push((*bound).into());
                         self.visit_expr(expr);
@@ -215,7 +215,7 @@ fn fn_sig_opt<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<PolyFnSig<'
     let node_ty = cx.typeck_results().node_type_opt(hir_id)?;
     // We can't use `Ty::fn_sig` because it automatically performs substs, this may result in FNs.
     match node_ty.kind() {
-        ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id)),
+        ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id).subst_identity()),
         ty::FnPtr(fn_sig) => Some(*fn_sig),
         _ => None,
     }
diff --git a/src/tools/clippy/clippy_lints/src/dereference.rs b/src/tools/clippy/clippy_lints/src/dereference.rs
index 05f2b92c037..6c333afacc6 100644
--- a/src/tools/clippy/clippy_lints/src/dereference.rs
+++ b/src/tools/clippy/clippy_lints/src/dereference.rs
@@ -759,7 +759,7 @@ fn walk_parents<'tcx>(
             }) if span.ctxt() == ctxt => {
                 let output = cx
                     .tcx
-                    .erase_late_bound_regions(cx.tcx.fn_sig(owner_id.to_def_id()).output());
+                    .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output());
                 Some(ty_auto_deref_stability(cx, output, precedence).position_for_result(cx))
             },
 
@@ -778,20 +778,20 @@ fn walk_parents<'tcx>(
 
             Node::Expr(parent) if parent.span.ctxt() == ctxt => match parent.kind {
                 ExprKind::Ret(_) => {
-                    let owner_id = cx.tcx.hir().body_owner(cx.enclosing_body.unwrap());
+                    let owner_id = cx.tcx.hir().body_owner_def_id(cx.enclosing_body.unwrap());
                     Some(
                         if let Node::Expr(
                             closure_expr @ Expr {
                                 kind: ExprKind::Closure(closure),
                                 ..
                             },
-                        ) = cx.tcx.hir().get(owner_id)
+                        ) = cx.tcx.hir().get_by_def_id(owner_id)
                         {
                             closure_result_position(cx, closure, cx.typeck_results().expr_ty(closure_expr), precedence)
                         } else {
                             let output = cx
                                 .tcx
-                                .erase_late_bound_regions(cx.tcx.fn_sig(cx.tcx.hir().local_def_id(owner_id)).output());
+                                .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output());
                             ty_auto_deref_stability(cx, output, precedence).position_for_result(cx)
                         },
                     )
@@ -858,7 +858,7 @@ fn walk_parents<'tcx>(
                             && let subs = cx
                                 .typeck_results()
                                 .node_substs_opt(parent.hir_id).map(|subs| &subs[1..]).unwrap_or_default()
-                            && let impl_ty = if cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref() {
+                            && let impl_ty = if cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[0].is_ref() {
                                 // Trait methods taking `&self`
                                 sub_ty
                             } else {
@@ -879,7 +879,7 @@ fn walk_parents<'tcx>(
                         return Some(Position::MethodReceiver);
                     }
                     args.iter().position(|arg| arg.hir_id == child_id).map(|i| {
-                        let ty = cx.tcx.fn_sig(id).skip_binder().inputs()[i + 1];
+                        let ty = cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i + 1];
                         // `e.hir_id == child_id` for https://github.com/rust-lang/rust-clippy/issues/9739
                         // `method.args.is_none()` for https://github.com/rust-lang/rust-clippy/issues/9782
                         if e.hir_id == child_id && method.args.is_none() && let ty::Param(param_ty) = ty.kind() {
@@ -896,7 +896,7 @@ fn walk_parents<'tcx>(
                         } else {
                             ty_auto_deref_stability(
                                 cx,
-                                cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).input(i + 1)),
+                                cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).subst_identity().input(i + 1)),
                                 precedence,
                             )
                             .position_for_arg()
@@ -1093,7 +1093,7 @@ fn needless_borrow_impl_arg_position<'tcx>(
     let sized_trait_def_id = cx.tcx.lang_items().sized_trait();
 
     let Some(callee_def_id) = fn_def_id(cx, parent) else { return Position::Other(precedence) };
-    let fn_sig = cx.tcx.fn_sig(callee_def_id).skip_binder();
+    let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
     let substs_with_expr_ty = cx
         .typeck_results()
         .node_substs(if let ExprKind::Call(callee, _) = parent.kind {
@@ -1221,7 +1221,7 @@ fn has_ref_mut_self_method(cx: &LateContext<'_>, trait_def_id: DefId) -> bool {
         .in_definition_order()
         .any(|assoc_item| {
             if assoc_item.fn_has_self_parameter {
-                let self_ty = cx.tcx.fn_sig(assoc_item.def_id).skip_binder().inputs()[0];
+                let self_ty = cx.tcx.fn_sig(assoc_item.def_id).subst_identity().skip_binder().inputs()[0];
                 matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Mut))
             } else {
                 false
@@ -1419,6 +1419,7 @@ fn ty_auto_deref_stability<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, precedenc
             | ty::FnDef(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Closure(..)
             | ty::Never
             | ty::Tuple(_)
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
index 248d7388410..f8fc726d603 100644
--- a/src/tools/clippy/clippy_lints/src/derive.rs
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -7,7 +7,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
 use rustc_hir::{
-    self as hir, BlockCheckMode, BodyId, Constness, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, UnsafeSource,
+    self as hir, BlockCheckMode, BodyId, Constness, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, UnsafeSource,
     Unsafety,
 };
 use rustc_lint::{LateContext, LateLintPass};
@@ -18,6 +18,7 @@ use rustc_middle::ty::{
     TraitPredicate, Ty, TyCtxt,
 };
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::sym;
 
@@ -425,7 +426,7 @@ struct UnsafeVisitor<'a, 'tcx> {
 impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
     type NestedFilter = nested_filter::All;
 
-    fn visit_fn(&mut self, kind: FnKind<'tcx>, decl: &'tcx FnDecl<'_>, body_id: BodyId, _: Span, id: HirId) {
+    fn visit_fn(&mut self, kind: FnKind<'tcx>, decl: &'tcx FnDecl<'_>, body_id: BodyId, _: Span, id: LocalDefId) {
         if self.has_unsafe {
             return;
         }
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
index cdc23a4d227..127201b72e2 100644
--- a/src/tools/clippy/clippy_lints/src/doc.rs
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -23,7 +23,6 @@ use rustc_parse::maybe_new_parser_from_source_str;
 use rustc_parse::parser::ForceCollect;
 use rustc_session::parse::ParseSess;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::def_id::LocalDefId;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::{BytePos, FilePathMapping, SourceMap, Span};
 use rustc_span::{sym, FileName, Pos};
@@ -251,7 +250,7 @@ declare_clippy_lint! {
     ///     unimplemented!();
     /// }
     /// ```
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub UNNECESSARY_SAFETY_DOC,
     restriction,
     "`pub fn` or `pub trait` with `# Safety` docs"
@@ -302,7 +301,7 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
                         panic_span: None,
                     };
                     fpu.visit_expr(body.value);
-                    lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, Some(body_id), fpu.panic_span);
+                    lint_for_missing_headers(cx, item.owner_id, sig, headers, Some(body_id), fpu.panic_span);
                 }
             },
             hir::ItemKind::Impl(impl_) => {
@@ -338,7 +337,7 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
         let Some(headers) = check_attrs(cx, &self.valid_idents, attrs) else { return };
         if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
             if !in_external_macro(cx.tcx.sess, item.span) {
-                lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, None, None);
+                lint_for_missing_headers(cx, item.owner_id, sig, headers, None, None);
             }
         }
     }
@@ -357,20 +356,20 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
                 panic_span: None,
             };
             fpu.visit_expr(body.value);
-            lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, Some(body_id), fpu.panic_span);
+            lint_for_missing_headers(cx, item.owner_id, sig, headers, Some(body_id), fpu.panic_span);
         }
     }
 }
 
 fn lint_for_missing_headers(
     cx: &LateContext<'_>,
-    def_id: LocalDefId,
+    owner_id: hir::OwnerId,
     sig: &hir::FnSig<'_>,
     headers: DocHeaders,
     body_id: Option<hir::BodyId>,
     panic_span: Option<Span>,
 ) {
-    if !cx.effective_visibilities.is_exported(def_id) {
+    if !cx.effective_visibilities.is_exported(owner_id.def_id) {
         return; // Private functions do not require doc comments
     }
 
@@ -378,13 +377,13 @@ fn lint_for_missing_headers(
     if cx
         .tcx
         .hir()
-        .parent_iter(cx.tcx.hir().local_def_id_to_hir_id(def_id))
+        .parent_iter(owner_id.into())
         .any(|(id, _node)| is_doc_hidden(cx.tcx.hir().attrs(id)))
     {
         return;
     }
 
-    let span = cx.tcx.def_span(def_id);
+    let span = cx.tcx.def_span(owner_id);
     match (headers.safety, sig.header.unsafety) {
         (false, hir::Unsafety::Unsafe) => span_lint(
             cx,
@@ -411,8 +410,7 @@ fn lint_for_missing_headers(
         );
     }
     if !headers.errors {
-        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
-        if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
+        if is_type_diagnostic_item(cx, return_ty(cx, owner_id), sym::Result) {
             span_lint(
                 cx,
                 MISSING_ERRORS_DOC,
diff --git a/src/tools/clippy/clippy_lints/src/enum_variants.rs b/src/tools/clippy/clippy_lints/src/enum_variants.rs
index b77b5621b4c..4c69dacf381 100644
--- a/src/tools/clippy/clippy_lints/src/enum_variants.rs
+++ b/src/tools/clippy/clippy_lints/src/enum_variants.rs
@@ -277,7 +277,7 @@ impl LateLintPass<'_> for EnumVariantNames {
                                 Some(c) if is_word_beginning(c) => span_lint(
                                     cx,
                                     MODULE_NAME_REPETITIONS,
-                                    item.span,
+                                    item.ident.span,
                                     "item name starts with its containing module's name",
                                 ),
                                 _ => (),
@@ -287,7 +287,7 @@ impl LateLintPass<'_> for EnumVariantNames {
                             span_lint(
                                 cx,
                                 MODULE_NAME_REPETITIONS,
-                                item.span,
+                                item.ident.span,
                                 "item name ends with its containing module's name",
                             );
                         }
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index dfb43893326..d6ab4c25e83 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -8,6 +8,7 @@ use rustc_middle::mir::FakeReadCause;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::{self, TraitRef, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::kw;
 use rustc_target::spec::abi::Abi;
@@ -63,7 +64,7 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
         _: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         _: Span,
-        hir_id: HirId,
+        fn_def_id: LocalDefId,
     ) {
         if let Some(header) = fn_kind.header() {
             if header.abi != Abi::Rust {
@@ -71,7 +72,11 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
             }
         }
 
-        let parent_id = cx.tcx.hir().get_parent_item(hir_id).def_id;
+        let parent_id = cx
+            .tcx
+            .hir()
+            .get_parent_item(cx.tcx.hir().local_def_id_to_hir_id(fn_def_id))
+            .def_id;
         let parent_node = cx.tcx.hir().find_by_def_id(parent_id);
 
         let mut trait_self_ty = None;
@@ -84,7 +89,7 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
             // find `self` ty for this trait if relevant
             if let ItemKind::Trait(_, _, _, _, items) = item.kind {
                 for trait_item in items {
-                    if trait_item.id.hir_id() == hir_id {
+                    if trait_item.id.owner_id.def_id == fn_def_id {
                         // be sure we have `self` parameter in this function
                         if trait_item.kind == (AssocItemKind::Fn { has_self: true }) {
                             trait_self_ty = Some(
@@ -105,7 +110,6 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
             too_large_for_stack: self.too_large_for_stack,
         };
 
-        let fn_def_id = cx.tcx.hir().local_def_id(hir_id);
         let infcx = cx.tcx.infer_ctxt().build();
         ExprUseVisitor::new(&mut v, &infcx, fn_def_id, cx.param_env, cx.typeck_results()).consume_body(body);
 
diff --git a/src/tools/clippy/clippy_lints/src/excessive_bools.rs b/src/tools/clippy/clippy_lints/src/excessive_bools.rs
index fc2912f696e..9d089fcad70 100644
--- a/src/tools/clippy/clippy_lints/src/excessive_bools.rs
+++ b/src/tools/clippy/clippy_lints/src/excessive_bools.rs
@@ -1,10 +1,11 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::{get_parent_as_impl, has_repr_attr, is_bool};
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, FnDecl, HirId, Item, ItemKind, TraitFn, TraitItem, TraitItemKind, Ty};
+use rustc_hir::{Body, FnDecl, Item, ItemKind, TraitFn, TraitItem, TraitItemKind, Ty};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::Span;
+use rustc_span::def_id::LocalDefId;
 use rustc_target::spec::abi::Abi;
 
 declare_clippy_lint! {
@@ -168,8 +169,9 @@ impl<'tcx> LateLintPass<'tcx> for ExcessiveBools {
         fn_decl: &'tcx FnDecl<'tcx>,
         _: &'tcx Body<'tcx>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
         if let Some(fn_header) = fn_kind.header()
             && fn_header.abi == Abi::Rust
             && get_parent_as_impl(cx.tcx, hir_id)
diff --git a/src/tools/clippy/clippy_lints/src/exhaustive_items.rs b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
index 1fece5d1c48..9fd13084dc9 100644
--- a/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
+++ b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
@@ -79,8 +79,7 @@ impl LateLintPass<'_> for ExhaustiveItems {
             then {
                 let (lint, msg) = if let ItemKind::Struct(ref v, ..) = item.kind {
                     if v.fields().iter().any(|f| {
-                        let def_id = cx.tcx.hir().local_def_id(f.hir_id);
-                        !cx.tcx.visibility(def_id).is_public()
+                        !cx.tcx.visibility(f.def_id).is_public()
                     }) {
                         // skip structs with private fields
                         return;
diff --git a/src/tools/clippy/clippy_lints/src/format_args.rs b/src/tools/clippy/clippy_lints/src/format_args.rs
index 043112bbc95..d376ad3bfe3 100644
--- a/src/tools/clippy/clippy_lints/src/format_args.rs
+++ b/src/tools/clippy/clippy_lints/src/format_args.rs
@@ -7,14 +7,14 @@ use clippy_utils::macros::{
 };
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::snippet_opt;
-use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::ty::{implements_trait, is_type_lang_item};
 use if_chain::if_chain;
 use itertools::Itertools;
 use rustc_errors::{
     Applicability,
     SuggestionStyle::{CompletelyHidden, ShowCode},
 };
-use rustc_hir::{Expr, ExprKind, HirId, QPath};
+use rustc_hir::{Expr, ExprKind, HirId, LangItem, QPath};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment};
 use rustc_middle::ty::Ty;
@@ -237,7 +237,7 @@ fn check_unused_format_specifier(cx: &LateContext<'_>, arg: &FormatArg<'_>) {
         );
     }
 
-    if is_type_diagnostic_item(cx, param_ty, sym::Arguments) && !arg.format.is_default_for_trait() {
+    if is_type_lang_item(cx, param_ty, LangItem::FormatArguments) && !arg.format.is_default_for_trait() {
         span_lint_and_then(
             cx,
             UNUSED_FORMAT_SPECS,
@@ -311,6 +311,10 @@ fn check_uninlined_args(
     // in those cases, make the code suggestion hidden
     let multiline_fix = fixes.iter().any(|(span, _)| cx.sess().source_map().is_multiline(*span));
 
+    // Suggest removing each argument only once, for example in `format!("{0} {0}", arg)`.
+    fixes.sort_unstable_by_key(|(span, _)| *span);
+    fixes.dedup_by_key(|(span, _)| *span);
+
     span_lint_and_then(
         cx,
         UNINLINED_FORMAT_ARGS,
diff --git a/src/tools/clippy/clippy_lints/src/from_raw_with_void_ptr.rs b/src/tools/clippy/clippy_lints/src/from_raw_with_void_ptr.rs
index 00f5ba56496..096508dc4f1 100644
--- a/src/tools/clippy/clippy_lints/src/from_raw_with_void_ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/from_raw_with_void_ptr.rs
@@ -31,7 +31,7 @@ declare_clippy_lint! {
     /// let _ = unsafe { Box::from_raw(ptr as *mut usize) };
     /// ```
     ///
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub FROM_RAW_WITH_VOID_PTR,
     suspicious,
     "creating a `Box` from a void raw pointer"
diff --git a/src/tools/clippy/clippy_lints/src/functions/misnamed_getters.rs b/src/tools/clippy/clippy_lints/src/functions/misnamed_getters.rs
index 27acad45ccf..d6b50537c2e 100644
--- a/src/tools/clippy/clippy_lints/src/functions/misnamed_getters.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/misnamed_getters.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use rustc_errors::Applicability;
-use rustc_hir::{intravisit::FnKind, Body, ExprKind, FnDecl, HirId, ImplicitSelfKind, Unsafety};
+use rustc_hir::{intravisit::FnKind, Body, ExprKind, FnDecl, ImplicitSelfKind, Unsafety};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::Span;
@@ -16,7 +16,6 @@ pub fn check_fn(
     decl: &FnDecl<'_>,
     body: &Body<'_>,
     span: Span,
-    _hir_id: HirId,
 ) {
     let FnKind::Method(ref ident, sig) = kind else {
             return;
diff --git a/src/tools/clippy/clippy_lints/src/functions/mod.rs b/src/tools/clippy/clippy_lints/src/functions/mod.rs
index 9dbce3f889b..4399c68e130 100644
--- a/src/tools/clippy/clippy_lints/src/functions/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/mod.rs
@@ -9,6 +9,7 @@ use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 
 declare_clippy_lint! {
@@ -363,12 +364,13 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
         decl: &'tcx hir::FnDecl<'_>,
         body: &'tcx hir::Body<'_>,
         span: Span,
-        hir_id: hir::HirId,
+        def_id: LocalDefId,
     ) {
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
         too_many_arguments::check_fn(cx, kind, decl, span, hir_id, self.too_many_arguments_threshold);
         too_many_lines::check_fn(cx, kind, span, body, self.too_many_lines_threshold);
-        not_unsafe_ptr_arg_deref::check_fn(cx, kind, decl, body, hir_id);
-        misnamed_getters::check_fn(cx, kind, decl, body, span, hir_id);
+        not_unsafe_ptr_arg_deref::check_fn(cx, kind, decl, body, def_id);
+        misnamed_getters::check_fn(cx, kind, decl, body, span);
     }
 
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
diff --git a/src/tools/clippy/clippy_lints/src/functions/must_use.rs b/src/tools/clippy/clippy_lints/src/functions/must_use.rs
index d22bede36b4..29bdc46b647 100644
--- a/src/tools/clippy/clippy_lints/src/functions/must_use.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/must_use.rs
@@ -1,6 +1,6 @@
 use rustc_ast::ast::Attribute;
 use rustc_errors::Applicability;
-use rustc_hir::def_id::{DefIdSet, LocalDefId};
+use rustc_hir::def_id::DefIdSet;
 use rustc_hir::{self as hir, def::Res, QPath};
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::{
@@ -27,14 +27,14 @@ pub(super) fn check_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>
         let is_public = cx.effective_visibilities.is_exported(item.owner_id.def_id);
         let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
         if let Some(attr) = attr {
-            check_needless_must_use(cx, sig.decl, item.hir_id(), item.span, fn_header_span, attr);
+            check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr);
         } else if is_public && !is_proc_macro(cx.sess(), attrs) && !attrs.iter().any(|a| a.has_name(sym::no_mangle)) {
             check_must_use_candidate(
                 cx,
                 sig.decl,
                 cx.tcx.hir().body(*body_id),
                 item.span,
-                item.owner_id.def_id,
+                item.owner_id,
                 item.span.with_hi(sig.decl.output.span().hi()),
                 "this function could have a `#[must_use]` attribute",
             );
@@ -49,7 +49,7 @@ pub(super) fn check_impl_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Imp
         let attrs = cx.tcx.hir().attrs(item.hir_id());
         let attr = cx.tcx.get_attr(item.owner_id.to_def_id(), sym::must_use);
         if let Some(attr) = attr {
-            check_needless_must_use(cx, sig.decl, item.hir_id(), item.span, fn_header_span, attr);
+            check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr);
         } else if is_public
             && !is_proc_macro(cx.sess(), attrs)
             && trait_ref_of_method(cx, item.owner_id.def_id).is_none()
@@ -59,7 +59,7 @@ pub(super) fn check_impl_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Imp
                 sig.decl,
                 cx.tcx.hir().body(*body_id),
                 item.span,
-                item.owner_id.def_id,
+                item.owner_id,
                 item.span.with_hi(sig.decl.output.span().hi()),
                 "this method could have a `#[must_use]` attribute",
             );
@@ -75,7 +75,7 @@ pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Tr
         let attrs = cx.tcx.hir().attrs(item.hir_id());
         let attr = cx.tcx.get_attr(item.owner_id.to_def_id(), sym::must_use);
         if let Some(attr) = attr {
-            check_needless_must_use(cx, sig.decl, item.hir_id(), item.span, fn_header_span, attr);
+            check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr);
         } else if let hir::TraitFn::Provided(eid) = *eid {
             let body = cx.tcx.hir().body(eid);
             if attr.is_none() && is_public && !is_proc_macro(cx.sess(), attrs) {
@@ -84,7 +84,7 @@ pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Tr
                     sig.decl,
                     body,
                     item.span,
-                    item.owner_id.def_id,
+                    item.owner_id,
                     item.span.with_hi(sig.decl.output.span().hi()),
                     "this method could have a `#[must_use]` attribute",
                 );
@@ -96,7 +96,7 @@ pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Tr
 fn check_needless_must_use(
     cx: &LateContext<'_>,
     decl: &hir::FnDecl<'_>,
-    item_id: hir::HirId,
+    item_id: hir::OwnerId,
     item_span: Span,
     fn_header_span: Span,
     attr: &Attribute,
@@ -131,7 +131,7 @@ fn check_must_use_candidate<'tcx>(
     decl: &'tcx hir::FnDecl<'_>,
     body: &'tcx hir::Body<'_>,
     item_span: Span,
-    item_id: LocalDefId,
+    item_id: hir::OwnerId,
     fn_span: Span,
     msg: &str,
 ) {
@@ -139,8 +139,8 @@ fn check_must_use_candidate<'tcx>(
         || mutates_static(cx, body)
         || in_external_macro(cx.sess(), item_span)
         || returns_unit(decl)
-        || !cx.effective_visibilities.is_exported(item_id)
-        || is_must_use_ty(cx, return_ty(cx, cx.tcx.hir().local_def_id_to_hir_id(item_id)))
+        || !cx.effective_visibilities.is_exported(item_id.def_id)
+        || is_must_use_ty(cx, return_ty(cx, item_id))
     {
         return;
     }
diff --git a/src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs b/src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs
index 2c0bf551fd7..a13909a2cdb 100644
--- a/src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs
@@ -17,7 +17,7 @@ pub(super) fn check_fn<'tcx>(
     kind: intravisit::FnKind<'tcx>,
     decl: &'tcx hir::FnDecl<'tcx>,
     body: &'tcx hir::Body<'tcx>,
-    hir_id: hir::HirId,
+    def_id: LocalDefId,
 ) {
     let unsafety = match kind {
         intravisit::FnKind::ItemFn(_, _, hir::FnHeader { unsafety, .. }) => unsafety,
@@ -25,7 +25,7 @@ pub(super) fn check_fn<'tcx>(
         intravisit::FnKind::Closure => return,
     };
 
-    check_raw_ptr(cx, unsafety, decl, body, cx.tcx.hir().local_def_id(hir_id));
+    check_raw_ptr(cx, unsafety, decl, body, def_id)
 }
 
 pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
@@ -58,7 +58,7 @@ fn check_raw_ptr<'tcx>(
                     },
                     hir::ExprKind::MethodCall(_, recv, args, _) => {
                         let def_id = typeck.type_dependent_def_id(e.hir_id).unwrap();
-                        if cx.tcx.fn_sig(def_id).skip_binder().unsafety == hir::Unsafety::Unsafe {
+                        if cx.tcx.fn_sig(def_id).skip_binder().skip_binder().unsafety == hir::Unsafety::Unsafe {
                             check_arg(cx, &raw_ptrs, recv);
                             for arg in args {
                                 check_arg(cx, &raw_ptrs, arg);
diff --git a/src/tools/clippy/clippy_lints/src/functions/result.rs b/src/tools/clippy/clippy_lints/src/functions/result.rs
index 23da145d038..fa2a9b30c05 100644
--- a/src/tools/clippy/clippy_lints/src/functions/result.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/result.rs
@@ -21,7 +21,7 @@ fn result_err_ty<'tcx>(
 ) -> Option<(&'tcx hir::Ty<'tcx>, Ty<'tcx>)> {
     if !in_external_macro(cx.sess(), item_span)
         && let hir::FnRetTy::Return(hir_ty) = decl.output
-        && let ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).output())
+        && let ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).subst_identity().output())
         && is_type_diagnostic_item(cx, ty, sym::Result)
         && let ty::Adt(_, substs) = ty.kind()
     {
diff --git a/src/tools/clippy/clippy_lints/src/future_not_send.rs b/src/tools/clippy/clippy_lints/src/future_not_send.rs
index 989f83cf80d..9fb73a371b8 100644
--- a/src/tools/clippy/clippy_lints/src/future_not_send.rs
+++ b/src/tools/clippy/clippy_lints/src/future_not_send.rs
@@ -1,11 +1,12 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::return_ty;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, FnDecl, HirId};
+use rustc_hir::{Body, FnDecl};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, AliasTy, Clause, EarlyBinder, PredicateKind};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{sym, Span};
 use rustc_trait_selection::traits::error_reporting::suggestions::TypeErrCtxtExt;
 use rustc_trait_selection::traits::{self, FulfillmentError};
@@ -56,12 +57,12 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
         decl: &'tcx FnDecl<'tcx>,
         _: &'tcx Body<'tcx>,
         _: Span,
-        hir_id: HirId,
+        fn_def_id: LocalDefId,
     ) {
         if let FnKind::Closure = kind {
             return;
         }
-        let ret_ty = return_ty(cx, hir_id);
+        let ret_ty = return_ty(cx, cx.tcx.hir().local_def_id_to_hir_id(fn_def_id).expect_owner());
         if let ty::Alias(ty::Opaque, AliasTy { def_id, substs, .. }) = *ret_ty.kind() {
             let preds = cx.tcx.explicit_item_bounds(def_id);
             let mut is_future = false;
@@ -78,7 +79,7 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
                 let send_trait = cx.tcx.get_diagnostic_item(sym::Send).unwrap();
                 let span = decl.output.span();
                 let infcx = cx.tcx.infer_ctxt().build();
-                let cause = traits::ObligationCause::misc(span, hir_id);
+                let cause = traits::ObligationCause::misc(span, fn_def_id);
                 let send_errors = traits::fully_solve_bound(&infcx, cause, cx.param_env, ret_ty, send_trait);
                 if !send_errors.is_empty() {
                     span_lint_and_then(
diff --git a/src/tools/clippy/clippy_lints/src/implicit_return.rs b/src/tools/clippy/clippy_lints/src/implicit_return.rs
index 946d04eff6f..372b6ead3fe 100644
--- a/src/tools/clippy/clippy_lints/src/implicit_return.rs
+++ b/src/tools/clippy/clippy_lints/src/implicit_return.rs
@@ -11,6 +11,7 @@ use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, FnRetTy, HirId};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{Span, SyntaxContext};
 
 declare_clippy_lint! {
@@ -223,7 +224,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitReturn {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        _: HirId,
+        _: LocalDefId,
     ) {
         if (!matches!(kind, FnKind::Closure) && matches!(decl.output, FnRetTy::DefaultReturn(_)))
             || span.ctxt() != body.value.span.ctxt()
diff --git a/src/tools/clippy/clippy_lints/src/inherent_to_string.rs b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
index aaecc4fa8f2..d43e5cc9b2c 100644
--- a/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
+++ b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
@@ -105,7 +105,7 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
             if impl_item.generics.params.iter().all(|p| matches!(p.kind, GenericParamKind::Lifetime { .. }));
 
             // Check if return type is String
-            if is_type_lang_item(cx, return_ty(cx, impl_item.hir_id()), LangItem::String);
+            if is_type_lang_item(cx, return_ty(cx, impl_item.owner_id), LangItem::String);
 
             // Filters instances of to_string which are required by a trait
             if trait_ref_of_method(cx, impl_item.owner_id.def_id).is_none();
@@ -124,7 +124,7 @@ fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
         .expect("Failed to get trait ID of `Display`!");
 
     // Get the real type of 'self'
-    let self_type = cx.tcx.fn_sig(item.owner_id).input(0);
+    let self_type = cx.tcx.fn_sig(item.owner_id).skip_binder().input(0);
     let self_type = self_type.skip_binder().peel_refs();
 
     // Emit either a warning or an error
diff --git a/src/tools/clippy/clippy_lints/src/instant_subtraction.rs b/src/tools/clippy/clippy_lints/src/instant_subtraction.rs
index 9f6e8940571..668110c7cc0 100644
--- a/src/tools/clippy/clippy_lints/src/instant_subtraction.rs
+++ b/src/tools/clippy/clippy_lints/src/instant_subtraction.rs
@@ -59,7 +59,7 @@ declare_clippy_lint! {
     ///
     /// [`Duration`]: std::time::Duration
     /// [`Instant::now()`]: std::time::Instant::now;
-    #[clippy::version = "1.65.0"]
+    #[clippy::version = "1.67.0"]
     pub UNCHECKED_DURATION_SUBTRACTION,
     pedantic,
     "finds unchecked subtraction of a 'Duration' from an 'Instant'"
diff --git a/src/tools/clippy/clippy_lints/src/iter_not_returning_iterator.rs b/src/tools/clippy/clippy_lints/src/iter_not_returning_iterator.rs
index e76de77f195..7557a9ce13f 100644
--- a/src/tools/clippy/clippy_lints/src/iter_not_returning_iterator.rs
+++ b/src/tools/clippy/clippy_lints/src/iter_not_returning_iterator.rs
@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for IterNotReturningIterator {
 
 fn check_sig(cx: &LateContext<'_>, name: &str, sig: &FnSig<'_>, fn_id: LocalDefId) {
     if sig.decl.implicit_self.has_implicit_self() {
-        let ret_ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(fn_id).output());
+        let ret_ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(fn_id).subst_identity().output());
         let ret_ty = cx
             .tcx
             .try_normalize_erasing_regions(cx.param_env, ret_ty)
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index 3c70c9cf19a..80ed2862a41 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -144,7 +144,7 @@ impl<'tcx> LateLintPass<'tcx> for LenZero {
             if let Some(local_id) = ty_id.as_local();
             let ty_hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_id);
             if !is_lint_allowed(cx, LEN_WITHOUT_IS_EMPTY, ty_hir_id);
-            if let Some(output) = parse_len_output(cx, cx.tcx.fn_sig(item.owner_id).skip_binder());
+            if let Some(output) = parse_len_output(cx, cx.tcx.fn_sig(item.owner_id).subst_identity().skip_binder());
             then {
                 let (name, kind) = match cx.tcx.hir().find(ty_hir_id) {
                     Some(Node::ForeignItem(x)) => (x.ident.name, "extern type"),
@@ -196,7 +196,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
     fn is_named_self(cx: &LateContext<'_>, item: &TraitItemRef, name: Symbol) -> bool {
         item.ident.name == name
             && if let AssocItemKind::Fn { has_self } = item.kind {
-                has_self && { cx.tcx.fn_sig(item.id.owner_id).inputs().skip_binder().len() == 1 }
+                has_self && { cx.tcx.fn_sig(item.id.owner_id).skip_binder().inputs().skip_binder().len() == 1 }
             } else {
                 false
             }
@@ -224,7 +224,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
             .any(|i| {
                 i.kind == ty::AssocKind::Fn
                     && i.fn_has_self_parameter
-                    && cx.tcx.fn_sig(i.def_id).inputs().skip_binder().len() == 1
+                    && cx.tcx.fn_sig(i.def_id).skip_binder().inputs().skip_binder().len() == 1
             });
 
         if !is_empty_method_found {
@@ -342,7 +342,7 @@ fn check_for_is_empty<'tcx>(
         ),
         Some(is_empty)
             if !(is_empty.fn_has_self_parameter
-                && check_is_empty_sig(cx.tcx.fn_sig(is_empty.def_id).skip_binder(), self_kind, output)) =>
+                && check_is_empty_sig(cx.tcx.fn_sig(is_empty.def_id).subst_identity().skip_binder(), self_kind, output)) =>
         {
             (
                 format!(
@@ -473,7 +473,7 @@ fn has_is_empty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     /// Gets an `AssocItem` and return true if it matches `is_empty(self)`.
     fn is_is_empty(cx: &LateContext<'_>, item: &ty::AssocItem) -> bool {
         if item.kind == ty::AssocKind::Fn {
-            let sig = cx.tcx.fn_sig(item.def_id);
+            let sig = cx.tcx.fn_sig(item.def_id).skip_binder();
             let ty = sig.skip_binder();
             ty.inputs().len() == 1
         } else {
diff --git a/src/tools/clippy/clippy_lints/src/let_underscore.rs b/src/tools/clippy/clippy_lints/src/let_underscore.rs
index 61f87b91400..f8e35950980 100644
--- a/src/tools/clippy/clippy_lints/src/let_underscore.rs
+++ b/src/tools/clippy/clippy_lints/src/let_underscore.rs
@@ -84,7 +84,7 @@ declare_clippy_lint! {
     /// let _ = foo().await;
     /// # }
     /// ```
-    #[clippy::version = "1.66"]
+    #[clippy::version = "1.67.0"]
     pub LET_UNDERSCORE_FUTURE,
     suspicious,
     "non-binding `let` on a future"
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
index d8e2ae02c5a..d0683039776 100644
--- a/src/tools/clippy/clippy_lints/src/lib.rs
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -1,7 +1,6 @@
 #![feature(array_windows)]
 #![feature(binary_heap_into_iter_sorted)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(drain_filter)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
@@ -198,6 +197,7 @@ mod missing_trait_methods;
 mod mixed_read_write_in_expression;
 mod module_style;
 mod multi_assignments;
+mod multiple_unsafe_ops_per_block;
 mod mut_key;
 mod mut_mut;
 mod mut_reference;
@@ -908,6 +908,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(fn_null_check::FnNullCheck));
     store.register_late_pass(|_| Box::new(permissions_set_readonly_false::PermissionsSetReadonlyFalse));
     store.register_late_pass(|_| Box::new(size_of_ref::SizeOfRef));
+    store.register_late_pass(|_| Box::new(multiple_unsafe_ops_per_block::MultipleUnsafeOpsPerBlock));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 
diff --git a/src/tools/clippy/clippy_lints/src/lifetimes.rs b/src/tools/clippy/clippy_lints/src/lifetimes.rs
index 7cf1a6b8084..747a94ba5a6 100644
--- a/src/tools/clippy/clippy_lints/src/lifetimes.rs
+++ b/src/tools/clippy/clippy_lints/src/lifetimes.rs
@@ -15,7 +15,6 @@ use rustc_hir::{
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter as middle_nested_filter;
-use rustc_middle::ty::TyCtxt;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
@@ -154,7 +153,7 @@ fn check_fn_inner<'tcx>(
         .filter(|param| matches!(param.kind, GenericParamKind::Type { .. }));
 
     for typ in types {
-        for pred in generics.bounds_for_param(cx.tcx.hir().local_def_id(typ.hir_id)) {
+        for pred in generics.bounds_for_param(typ.def_id) {
             if pred.origin == PredicateOrigin::WhereClause {
                 // has_where_lifetimes checked that this predicate contains no lifetime.
                 continue;
@@ -251,7 +250,7 @@ fn could_use_elision<'tcx>(
     // level of the current item.
 
     // check named LTs
-    let allowed_lts = allowed_lts_from(cx.tcx, named_generics);
+    let allowed_lts = allowed_lts_from(named_generics);
 
     // these will collect all the lifetimes for references in arg/return types
     let mut input_visitor = RefVisitor::new(cx);
@@ -360,11 +359,11 @@ fn could_use_elision<'tcx>(
     }
 }
 
-fn allowed_lts_from(tcx: TyCtxt<'_>, named_generics: &[GenericParam<'_>]) -> FxHashSet<RefLt> {
+fn allowed_lts_from(named_generics: &[GenericParam<'_>]) -> FxHashSet<RefLt> {
     let mut allowed_lts = FxHashSet::default();
     for par in named_generics.iter() {
         if let GenericParamKind::Lifetime { .. } = par.kind {
-            allowed_lts.insert(RefLt::Named(tcx.hir().local_def_id(par.hir_id)));
+            allowed_lts.insert(RefLt::Named(par.def_id));
         }
     }
     allowed_lts.insert(RefLt::Unnamed);
@@ -516,7 +515,7 @@ fn has_where_lifetimes<'tcx>(cx: &LateContext<'tcx>, generics: &'tcx Generics<'_
                     return true;
                 }
                 // if the bounds define new lifetimes, they are fine to occur
-                let allowed_lts = allowed_lts_from(cx.tcx, pred.bound_generic_params);
+                let allowed_lts = allowed_lts_from(pred.bound_generic_params);
                 // now walk the bounds
                 for bound in pred.bounds.iter() {
                     walk_param_bound(&mut visitor, bound);
diff --git a/src/tools/clippy/clippy_lints/src/loops/needless_range_loop.rs b/src/tools/clippy/clippy_lints/src/loops/needless_range_loop.rs
index 3bca93d80aa..e6ed4ea7a5d 100644
--- a/src/tools/clippy/clippy_lints/src/loops/needless_range_loop.rs
+++ b/src/tools/clippy/clippy_lints/src/loops/needless_range_loop.rs
@@ -370,7 +370,7 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
             ExprKind::MethodCall(_, receiver, args, _) => {
                 let def_id = self.cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
                 for (ty, expr) in iter::zip(
-                    self.cx.tcx.fn_sig(def_id).inputs().skip_binder(),
+                    self.cx.tcx.fn_sig(def_id).subst_identity().inputs().skip_binder(),
                     std::iter::once(receiver).chain(args.iter()),
                 ) {
                     self.prefer_mutable = false;
diff --git a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
index 63212beaa63..3778eb4c732 100644
--- a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
@@ -6,10 +6,11 @@ use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
     AsyncGeneratorKind, Block, Body, Closure, Expr, ExprKind, FnDecl, FnRetTy, GeneratorKind, GenericArg, GenericBound,
-    HirId, ItemKind, LifetimeName, Term, TraitRef, Ty, TyKind, TypeBindingKind,
+    ItemKind, LifetimeName, Term, TraitRef, Ty, TyKind, TypeBindingKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
@@ -45,7 +46,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualAsyncFn {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        _: HirId,
+        _: LocalDefId,
     ) {
         if_chain! {
             if let Some(header) = kind.header();
diff --git a/src/tools/clippy/clippy_lints/src/manual_is_ascii_check.rs b/src/tools/clippy/clippy_lints/src/manual_is_ascii_check.rs
index d9ef7dffa02..2fd32c009ea 100644
--- a/src/tools/clippy/clippy_lints/src/manual_is_ascii_check.rs
+++ b/src/tools/clippy/clippy_lints/src/manual_is_ascii_check.rs
@@ -43,7 +43,7 @@ declare_clippy_lint! {
     ///     'A'.is_ascii_uppercase();
     /// }
     /// ```
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub MANUAL_IS_ASCII_CHECK,
     style,
     "use dedicated method to check ascii range"
diff --git a/src/tools/clippy/clippy_lints/src/manual_non_exhaustive.rs b/src/tools/clippy/clippy_lints/src/manual_non_exhaustive.rs
index bca193be9e7..9a84068d448 100644
--- a/src/tools/clippy/clippy_lints/src/manual_non_exhaustive.rs
+++ b/src/tools/clippy/clippy_lints/src/manual_non_exhaustive.rs
@@ -157,11 +157,10 @@ impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
             && def.variants.len() > 1
         {
             let mut iter = def.variants.iter().filter_map(|v| {
-                let id = cx.tcx.hir().local_def_id(v.hir_id);
-                (matches!(v.data, hir::VariantData::Unit(..))
+                (matches!(v.data, hir::VariantData::Unit(_, _))
                     && v.ident.as_str().starts_with('_')
                     && is_doc_hidden(cx.tcx.hir().attrs(v.hir_id)))
-                .then_some((id, v.span))
+                .then_some((v.def_id, v.span))
             });
             if let Some((id, span)) = iter.next()
                 && iter.next().is_none()
diff --git a/src/tools/clippy/clippy_lints/src/map_unit_fn.rs b/src/tools/clippy/clippy_lints/src/map_unit_fn.rs
index 59195d1ae4e..edcab6968cb 100644
--- a/src/tools/clippy/clippy_lints/src/map_unit_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/map_unit_fn.rs
@@ -104,7 +104,7 @@ fn is_unit_function(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
     let ty = cx.typeck_results().expr_ty(expr);
 
     if let ty::FnDef(id, _) = *ty.kind() {
-        if let Some(fn_type) = cx.tcx.fn_sig(id).no_bound_vars() {
+        if let Some(fn_type) = cx.tcx.fn_sig(id).subst_identity().no_bound_vars() {
             return is_unit_type(fn_type.output());
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/methods/collapsible_str_replace.rs b/src/tools/clippy/clippy_lints/src/methods/collapsible_str_replace.rs
index ac61b437788..5e01ed90ff0 100644
--- a/src/tools/clippy/clippy_lints/src/methods/collapsible_str_replace.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/collapsible_str_replace.rs
@@ -54,7 +54,7 @@ fn collect_replace_calls<'tcx>(
                 from_args.push_front(from);
                 ControlFlow::Continue(())
             } else {
-                ControlFlow::BREAK
+                ControlFlow::Break(())
             }
         } else {
             ControlFlow::Continue(())
diff --git a/src/tools/clippy/clippy_lints/src/methods/expect_fun_call.rs b/src/tools/clippy/clippy_lints/src/methods/expect_fun_call.rs
index a9189b31c57..aed0ad5d9b5 100644
--- a/src/tools/clippy/clippy_lints/src/methods/expect_fun_call.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/expect_fun_call.rs
@@ -70,7 +70,7 @@ pub(super) fn check<'tcx>(
                 if let hir::ExprKind::Path(ref p) = fun.kind {
                     match cx.qpath_res(p, fun.hir_id) {
                         hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!(
-                            cx.tcx.fn_sig(def_id).output().skip_binder().kind(),
+                            cx.tcx.fn_sig(def_id).subst_identity().output().skip_binder().kind(),
                             ty::Ref(re, ..) if re.is_static(),
                         ),
                         _ => false,
@@ -84,7 +84,7 @@ pub(super) fn check<'tcx>(
                     .type_dependent_def_id(arg.hir_id)
                     .map_or(false, |method_id| {
                         matches!(
-                            cx.tcx.fn_sig(method_id).output().skip_binder().kind(),
+                            cx.tcx.fn_sig(method_id).subst_identity().output().skip_binder().kind(),
                             ty::Ref(re, ..) if re.is_static()
                         )
                     })
diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs
index 77be61b4793..fb94dfa5980 100644
--- a/src/tools/clippy/clippy_lints/src/methods/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs
@@ -3102,7 +3102,7 @@ declare_clippy_lint! {
     ///     Ok(())
     /// }
     /// ```
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub SEEK_FROM_CURRENT,
     complexity,
     "use dedicated method for seek from current position"
@@ -3133,7 +3133,7 @@ declare_clippy_lint! {
     ///     t.rewind();
     /// }
     /// ```
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub SEEK_TO_START_INSTEAD_OF_REWIND,
     complexity,
     "jumping to the start of stream using `seek` method"
@@ -3352,7 +3352,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
 
         let implements_trait = matches!(item.kind, hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }));
         if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind {
-            let method_sig = cx.tcx.fn_sig(impl_item.owner_id);
+            let method_sig = cx.tcx.fn_sig(impl_item.owner_id).subst_identity();
             let method_sig = cx.tcx.erase_late_bound_regions(method_sig);
             let first_arg_ty_opt = method_sig.inputs().iter().next().copied();
             // if this impl block implements a trait, lint in trait definition instead
@@ -3412,7 +3412,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         }
 
         if let hir::ImplItemKind::Fn(_, _) = impl_item.kind {
-            let ret_ty = return_ty(cx, impl_item.hir_id());
+            let ret_ty = return_ty(cx, impl_item.owner_id);
 
             if contains_ty_adt_constructor_opaque(cx, ret_ty, self_ty) {
                 return;
@@ -3460,7 +3460,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         if_chain! {
             if item.ident.name == sym::new;
             if let TraitItemKind::Fn(_, _) = item.kind;
-            let ret_ty = return_ty(cx, item.hir_id());
+            let ret_ty = return_ty(cx, item.owner_id);
             let self_ty = TraitRef::identity(cx.tcx, item.owner_id.to_def_id())
                 .self_ty()
                 .skip_binder();
diff --git a/src/tools/clippy/clippy_lints/src/methods/needless_collect.rs b/src/tools/clippy/clippy_lints/src/methods/needless_collect.rs
index f4d3ef3b742..82d3b830d4f 100644
--- a/src/tools/clippy/clippy_lints/src/methods/needless_collect.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/needless_collect.rs
@@ -137,7 +137,7 @@ pub(super) fn check<'tcx>(
 /// Checks if the given method call matches the expected signature of `([&[mut]] self) -> bool`
 fn is_is_empty_sig(cx: &LateContext<'_>, call_id: HirId) -> bool {
     cx.typeck_results().type_dependent_def_id(call_id).map_or(false, |id| {
-        let sig = cx.tcx.fn_sig(id).skip_binder();
+        let sig = cx.tcx.fn_sig(id).subst_identity().skip_binder();
         sig.inputs().len() == 1 && sig.output().is_bool()
     })
 }
@@ -165,7 +165,7 @@ fn iterates_same_ty<'tcx>(cx: &LateContext<'tcx>, iter_ty: Ty<'tcx>, collect_ty:
 fn is_contains_sig(cx: &LateContext<'_>, call_id: HirId, iter_expr: &Expr<'_>) -> bool {
     let typeck = cx.typeck_results();
     if let Some(id) = typeck.type_dependent_def_id(call_id)
-        && let sig = cx.tcx.fn_sig(id)
+        && let sig = cx.tcx.fn_sig(id).subst_identity()
         && sig.skip_binder().output().is_bool()
         && let [_, search_ty] = *sig.skip_binder().inputs()
         && let ty::Ref(_, search_ty, Mutability::Not) = *cx.tcx.erase_late_bound_regions(sig.rebind(search_ty)).kind()
diff --git a/src/tools/clippy/clippy_lints/src/methods/suspicious_map.rs b/src/tools/clippy/clippy_lints/src/methods/suspicious_map.rs
index 2ac0786b37b..0dc7fe2a2c5 100644
--- a/src/tools/clippy/clippy_lints/src/methods/suspicious_map.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/suspicious_map.rs
@@ -11,10 +11,8 @@ use super::SUSPICIOUS_MAP;
 pub fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, count_recv: &hir::Expr<'_>, map_arg: &hir::Expr<'_>) {
     if_chain! {
         if is_trait_method(cx, count_recv, sym::Iterator);
-        let closure = expr_or_init(cx, map_arg);
-        if let Some(def_id) = cx.tcx.hir().opt_local_def_id(closure.hir_id);
-        if let Some(body_id) = cx.tcx.hir().maybe_body_owned_by(def_id);
-        let closure_body = cx.tcx.hir().body(body_id);
+        if let hir::ExprKind::Closure(closure) = expr_or_init(cx, map_arg).kind;
+        let closure_body = cx.tcx.hir().body(closure.body);
         if !cx.typeck_results().expr_ty(closure_body.value).is_unit();
         then {
             if let Some(map_mutated_vars) = mutated_variables(closure_body.value, cx) {
diff --git a/src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs b/src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs
index 9263f051972..4e5af1c7c71 100644
--- a/src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs
@@ -246,7 +246,7 @@ fn check_other_call_arg<'tcx>(
     if_chain! {
         if let Some((maybe_call, maybe_arg)) = skip_addr_of_ancestors(cx, expr);
         if let Some((callee_def_id, _, recv, call_args)) = get_callee_substs_and_args(cx, maybe_call);
-        let fn_sig = cx.tcx.fn_sig(callee_def_id).skip_binder();
+        let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
         if let Some(i) = recv.into_iter().chain(call_args).position(|arg| arg.hir_id == maybe_arg.hir_id);
         if let Some(input) = fn_sig.inputs().get(i);
         let (input, n_refs) = peel_mid_ty_refs(*input);
@@ -368,10 +368,9 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
             Node::Block(..) => continue,
             Node::Item(item) => {
                 if let ItemKind::Fn(_, _, body_id) = &item.kind
-                && let output_ty = return_ty(cx, item.hir_id())
-                && let local_def_id = cx.tcx.hir().local_def_id(item.hir_id())
-                && Inherited::build(cx.tcx, local_def_id).enter(|inherited| {
-                    let fn_ctxt = FnCtxt::new(inherited, cx.param_env, item.hir_id());
+                && let output_ty = return_ty(cx, item.owner_id)
+                && Inherited::build(cx.tcx, item.owner_id.def_id).enter(|inherited| {
+                    let fn_ctxt = FnCtxt::new(inherited, cx.param_env, item.owner_id.def_id);
                     fn_ctxt.can_coerce(ty, output_ty)
                 }) {
                     if has_lifetime(output_ty) && has_lifetime(ty) {
@@ -386,7 +385,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
             Node::Expr(parent_expr) => {
                 if let Some((callee_def_id, call_substs, recv, call_args)) = get_callee_substs_and_args(cx, parent_expr)
                 {
-                    let fn_sig = cx.tcx.fn_sig(callee_def_id).skip_binder();
+                    let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
                     if let Some(arg_index) = recv.into_iter().chain(call_args).position(|arg| arg.hir_id == expr.hir_id)
                         && let Some(param_ty) = fn_sig.inputs().get(arg_index)
                         && let ty::Param(ParamTy { index: param_index , ..}) = param_ty.kind()
diff --git a/src/tools/clippy/clippy_lints/src/misc.rs b/src/tools/clippy/clippy_lints/src/misc.rs
index 9f4beb92b9d..0705029a613 100644
--- a/src/tools/clippy/clippy_lints/src/misc.rs
+++ b/src/tools/clippy/clippy_lints/src/misc.rs
@@ -4,12 +4,13 @@ use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
-    self as hir, def, BinOpKind, BindingAnnotation, Body, ByRef, Expr, ExprKind, FnDecl, HirId, Mutability, PatKind,
-    Stmt, StmtKind, TyKind,
+    self as hir, def, BinOpKind, BindingAnnotation, Body, ByRef, Expr, ExprKind, FnDecl, Mutability, PatKind, Stmt,
+    StmtKind, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
 use rustc_span::source_map::{ExpnKind, Span};
 
@@ -151,7 +152,7 @@ impl<'tcx> LateLintPass<'tcx> for LintPass {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        _: HirId,
+        _: LocalDefId,
     ) {
         if let FnKind::Closure = k {
             // Does not apply to closures
diff --git a/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs b/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
index 5bc04bc17fb..87bd007a26a 100644
--- a/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
@@ -6,11 +6,12 @@ use clippy_utils::{fn_has_unsatisfiable_preds, is_entrypoint_fn, is_from_proc_ma
 use rustc_hir as hir;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, Constness, FnDecl, GenericParamKind, HirId};
+use rustc_hir::{Body, Constness, FnDecl, GenericParamKind};
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 
 declare_clippy_lint! {
@@ -91,14 +92,12 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
         _: &FnDecl<'_>,
         body: &Body<'tcx>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
         if !self.msrv.meets(msrvs::CONST_IF_MATCH) {
             return;
         }
 
-        let def_id = cx.tcx.hir().local_def_id(hir_id);
-
         if in_external_macro(cx.tcx.sess, span) || is_entrypoint_fn(cx, def_id.to_def_id()) {
             return;
         }
@@ -132,6 +131,8 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
             FnKind::Closure => return,
         }
 
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
+
         // Const fns are not allowed as methods in a trait.
         {
             let parent = cx.tcx.hir().get_parent_item(hir_id).def_id;
diff --git a/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs b/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
index 3371b4cce32..e99081ad062 100644
--- a/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
@@ -94,7 +94,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingTraitMethods {
                         "implement the method",
                     );
                 }
-            })
+            });
         }
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/multiple_unsafe_ops_per_block.rs b/src/tools/clippy/clippy_lints/src/multiple_unsafe_ops_per_block.rs
new file mode 100644
index 00000000000..2814c92e67a
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/multiple_unsafe_ops_per_block.rs
@@ -0,0 +1,185 @@
+use clippy_utils::{
+    diagnostics::span_lint_and_then,
+    visitors::{for_each_expr_with_closures, Descend, Visitable},
+};
+use core::ops::ControlFlow::Continue;
+use hir::{
+    def::{DefKind, Res},
+    BlockCheckMode, ExprKind, QPath, UnOp, Unsafety,
+};
+use rustc_ast::Mutability;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for `unsafe` blocks that contain more than one unsafe operation.
+    ///
+    /// ### Why is this bad?
+    /// Combined with `undocumented_unsafe_blocks`,
+    /// this lint ensures that each unsafe operation must be independently justified.
+    /// Combined with `unused_unsafe`, this lint also ensures
+    /// elimination of unnecessary unsafe blocks through refactoring.
+    ///
+    /// ### Example
+    /// ```rust
+    /// /// Reads a `char` from the given pointer.
+    /// ///
+    /// /// # Safety
+    /// ///
+    /// /// `ptr` must point to four consecutive, initialized bytes which
+    /// /// form a valid `char` when interpreted in the native byte order.
+    /// fn read_char(ptr: *const u8) -> char {
+    ///     // SAFETY: The caller has guaranteed that the value pointed
+    ///     // to by `bytes` is a valid `char`.
+    ///     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// /// Reads a `char` from the given pointer.
+    /// ///
+    /// /// # Safety
+    /// ///
+    /// /// - `ptr` must be 4-byte aligned, point to four consecutive
+    /// ///   initialized bytes, and be valid for reads of 4 bytes.
+    /// /// - The bytes pointed to by `ptr` must represent a valid
+    /// ///   `char` when interpreted in the native byte order.
+    /// fn read_char(ptr: *const u8) -> char {
+    ///     // SAFETY: `ptr` is 4-byte aligned, points to four consecutive
+    ///     // initialized bytes, and is valid for reads of 4 bytes.
+    ///     let int_value = unsafe { *ptr.cast::<u32>() };
+    ///
+    ///     // SAFETY: The caller has guaranteed that the four bytes
+    ///     // pointed to by `bytes` represent a valid `char`.
+    ///     unsafe { char::from_u32_unchecked(int_value) }
+    /// }
+    /// ```
+    #[clippy::version = "1.68.0"]
+    pub MULTIPLE_UNSAFE_OPS_PER_BLOCK,
+    restriction,
+    "more than one unsafe operation per `unsafe` block"
+}
+declare_lint_pass!(MultipleUnsafeOpsPerBlock => [MULTIPLE_UNSAFE_OPS_PER_BLOCK]);
+
+impl<'tcx> LateLintPass<'tcx> for MultipleUnsafeOpsPerBlock {
+    fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
+        if !matches!(block.rules, BlockCheckMode::UnsafeBlock(_)) {
+            return;
+        }
+        let mut unsafe_ops = vec![];
+        collect_unsafe_exprs(cx, block, &mut unsafe_ops);
+        if unsafe_ops.len() > 1 {
+            span_lint_and_then(
+                cx,
+                MULTIPLE_UNSAFE_OPS_PER_BLOCK,
+                block.span,
+                &format!(
+                    "this `unsafe` block contains {} unsafe operations, expected only one",
+                    unsafe_ops.len()
+                ),
+                |diag| {
+                    for (msg, span) in unsafe_ops {
+                        diag.span_note(span, msg);
+                    }
+                },
+            );
+        }
+    }
+}
+
+fn collect_unsafe_exprs<'tcx>(
+    cx: &LateContext<'tcx>,
+    node: impl Visitable<'tcx>,
+    unsafe_ops: &mut Vec<(&'static str, Span)>,
+) {
+    for_each_expr_with_closures(cx, node, |expr| {
+        match expr.kind {
+            ExprKind::InlineAsm(_) => unsafe_ops.push(("inline assembly used here", expr.span)),
+
+            ExprKind::Field(e, _) => {
+                if cx.typeck_results().expr_ty(e).is_union() {
+                    unsafe_ops.push(("union field access occurs here", expr.span));
+                }
+            },
+
+            ExprKind::Path(QPath::Resolved(
+                _,
+                hir::Path {
+                    res: Res::Def(DefKind::Static(Mutability::Mut), _),
+                    ..
+                },
+            )) => {
+                unsafe_ops.push(("access of a mutable static occurs here", expr.span));
+            },
+
+            ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty_adjusted(e).is_unsafe_ptr() => {
+                unsafe_ops.push(("raw pointer dereference occurs here", expr.span));
+            },
+
+            ExprKind::Call(path_expr, _) => match path_expr.kind {
+                ExprKind::Path(QPath::Resolved(
+                    _,
+                    hir::Path {
+                        res: Res::Def(kind, def_id),
+                        ..
+                    },
+                )) if kind.is_fn_like() => {
+                    let sig = cx.tcx.fn_sig(*def_id);
+                    if sig.0.unsafety() == Unsafety::Unsafe {
+                        unsafe_ops.push(("unsafe function call occurs here", expr.span));
+                    }
+                },
+
+                ExprKind::Path(QPath::TypeRelative(..)) => {
+                    if let Some(sig) = cx
+                        .typeck_results()
+                        .type_dependent_def_id(path_expr.hir_id)
+                        .map(|def_id| cx.tcx.fn_sig(def_id))
+                    {
+                        if sig.0.unsafety() == Unsafety::Unsafe {
+                            unsafe_ops.push(("unsafe function call occurs here", expr.span));
+                        }
+                    }
+                },
+
+                _ => {},
+            },
+
+            ExprKind::MethodCall(..) => {
+                if let Some(sig) = cx
+                    .typeck_results()
+                    .type_dependent_def_id(expr.hir_id)
+                    .map(|def_id| cx.tcx.fn_sig(def_id))
+                {
+                    if sig.0.unsafety() == Unsafety::Unsafe {
+                        unsafe_ops.push(("unsafe method call occurs here", expr.span));
+                    }
+                }
+            },
+
+            ExprKind::AssignOp(_, lhs, rhs) | ExprKind::Assign(lhs, rhs, _) => {
+                if matches!(
+                    lhs.kind,
+                    ExprKind::Path(QPath::Resolved(
+                        _,
+                        hir::Path {
+                            res: Res::Def(DefKind::Static(Mutability::Mut), _),
+                            ..
+                        }
+                    ))
+                ) {
+                    unsafe_ops.push(("modification of a mutable static occurs here", expr.span));
+                    collect_unsafe_exprs(cx, rhs, unsafe_ops);
+                    return Continue(Descend::No);
+                }
+            },
+
+            _ => {},
+        };
+
+        Continue::<(), _>(Descend::Yes)
+    });
+}
diff --git a/src/tools/clippy/clippy_lints/src/mut_key.rs b/src/tools/clippy/clippy_lints/src/mut_key.rs
index a651020ca65..5f7aac21e6e 100644
--- a/src/tools/clippy/clippy_lints/src/mut_key.rs
+++ b/src/tools/clippy/clippy_lints/src/mut_key.rs
@@ -6,6 +6,7 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::TypeVisitable;
 use rustc_middle::ty::{Adt, Array, Ref, Slice, Tuple, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::sym;
 use std::iter;
@@ -102,21 +103,21 @@ impl<'tcx> LateLintPass<'tcx> for MutableKeyType {
 
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
         if let hir::ItemKind::Fn(ref sig, ..) = item.kind {
-            self.check_sig(cx, item.hir_id(), sig.decl);
+            self.check_sig(cx, item.owner_id.def_id, sig.decl);
         }
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'tcx>) {
         if let hir::ImplItemKind::Fn(ref sig, ..) = item.kind {
             if trait_ref_of_method(cx, item.owner_id.def_id).is_none() {
-                self.check_sig(cx, item.hir_id(), sig.decl);
+                self.check_sig(cx, item.owner_id.def_id, sig.decl);
             }
         }
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'tcx>) {
         if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
-            self.check_sig(cx, item.hir_id(), sig.decl);
+            self.check_sig(cx, item.owner_id.def_id, sig.decl);
         }
     }
 
@@ -136,9 +137,8 @@ impl MutableKeyType {
         }
     }
 
-    fn check_sig(&self, cx: &LateContext<'_>, item_hir_id: hir::HirId, decl: &hir::FnDecl<'_>) {
-        let fn_def_id = cx.tcx.hir().local_def_id(item_hir_id);
-        let fn_sig = cx.tcx.fn_sig(fn_def_id);
+    fn check_sig(&self, cx: &LateContext<'_>, fn_def_id: LocalDefId, decl: &hir::FnDecl<'_>) {
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
         for (hir_ty, ty) in iter::zip(decl.inputs, fn_sig.inputs().skip_binder()) {
             self.check_ty_(cx, hir_ty.span, *ty);
         }
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 8c9d4c5cfe6..996ea6ed723 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -20,6 +20,7 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::mir::FakeReadCause;
 use rustc_middle::ty::{self, TypeVisitable};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::kw;
 use rustc_span::{sym, Span};
 use rustc_target::spec::abi::Abi;
@@ -82,12 +83,14 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        hir_id: HirId,
+        fn_def_id: LocalDefId,
     ) {
         if span.from_expansion() {
             return;
         }
 
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(fn_def_id);
+
         match kind {
             FnKind::ItemFn(.., header) => {
                 let attrs = cx.tcx.hir().attrs(hir_id);
@@ -119,8 +122,6 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
 
         let sized_trait = need!(cx.tcx.lang_items().sized_trait());
 
-        let fn_def_id = cx.tcx.hir().local_def_id(hir_id);
-
         let preds = traits::elaborate_predicates(cx.tcx, cx.param_env.caller_bounds().iter())
             .filter(|p| !p.is_global())
             .filter_map(|obligation| {
@@ -147,7 +148,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
             ctx
         };
 
-        let fn_sig = cx.tcx.fn_sig(fn_def_id);
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
         let fn_sig = cx.tcx.erase_late_bound_regions(fn_sig);
 
         for (idx, ((input, &ty), arg)) in decl.inputs.iter().zip(fn_sig.inputs()).zip(body.params).enumerate() {
diff --git a/src/tools/clippy/clippy_lints/src/new_without_default.rs b/src/tools/clippy/clippy_lints/src/new_without_default.rs
index 54a3c82b713..faf9ec61ec5 100644
--- a/src/tools/clippy/clippy_lints/src/new_without_default.rs
+++ b/src/tools/clippy/clippy_lints/src/new_without_default.rs
@@ -75,7 +75,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                     }
                     if let hir::ImplItemKind::Fn(ref sig, _) = impl_item.kind {
                         let name = impl_item.ident.name;
-                        let id = impl_item.hir_id();
+                        let id = impl_item.owner_id;
                         if sig.header.constness == hir::Constness::Const {
                             // can't be implemented by default
                             return;
@@ -97,7 +97,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                             if sig.decl.inputs.is_empty();
                             if name == sym::new;
                             if cx.effective_visibilities.is_reachable(impl_item.owner_id.def_id);
-                            let self_def_id = cx.tcx.hir().get_parent_item(id);
+                            let self_def_id = cx.tcx.hir().get_parent_item(id.into());
                             let self_ty = cx.tcx.type_of(self_def_id);
                             if self_ty == return_ty(cx, id);
                             if let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default);
@@ -133,7 +133,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                                 span_lint_hir_and_then(
                                     cx,
                                     NEW_WITHOUT_DEFAULT,
-                                    id,
+                                    id.into(),
                                     impl_item.span,
                                     &format!(
                                         "you should consider adding a `Default` implementation for `{self_type_snip}`"
diff --git a/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs b/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
index 7b1d974f2f8..8b77a5c99f7 100644
--- a/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
+++ b/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
@@ -7,7 +7,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::hir_id::HirIdMap;
 use rustc_hir::{Body, Expr, ExprKind, HirId, ImplItem, ImplItemKind, Node, PatKind, TraitItem, TraitItemKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
+use rustc_middle::ty::subst::{EarlyBinder, GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, ConstKind};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::symbol::{kw, Ident};
@@ -244,7 +244,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
             })) => {
                 #[allow(trivial_casts)]
                 if let Some(Node::Item(item)) = get_parent_node(cx.tcx, owner_id.into())
-                    && let Some(trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(|t| t.subst_identity())
+                    && let Some(trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(EarlyBinder::subst_identity)
                     && let Some(trait_item_id) = cx.tcx.associated_item(owner_id).trait_item_def_id
                 {
                     (
diff --git a/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs b/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
index cff82b875f1..d592f6e814c 100644
--- a/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
+++ b/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
@@ -209,7 +209,8 @@ impl<'tcx> LateLintPass<'tcx> for ArithmeticSideEffects {
 
     fn check_body(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
         let body_owner = cx.tcx.hir().body_owner(body.id());
-        let body_owner_def_id = cx.tcx.hir().local_def_id(body_owner);
+        let body_owner_def_id = cx.tcx.hir().body_owner_def_id(body.id());
+
         let body_owner_kind = cx.tcx.hir().body_owner_kind(body_owner_def_id);
         if let hir::BodyOwnerKind::Const | hir::BodyOwnerKind::Static(_) = body_owner_kind {
             let body_span = cx.tcx.hir().span_with_body(body_owner);
diff --git a/src/tools/clippy/clippy_lints/src/operators/numeric_arithmetic.rs b/src/tools/clippy/clippy_lints/src/operators/numeric_arithmetic.rs
index 0830a106f55..777395f452c 100644
--- a/src/tools/clippy/clippy_lints/src/operators/numeric_arithmetic.rs
+++ b/src/tools/clippy/clippy_lints/src/operators/numeric_arithmetic.rs
@@ -96,7 +96,7 @@ impl Context {
 
     pub fn enter_body(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
         let body_owner = cx.tcx.hir().body_owner(body.id());
-        let body_owner_def_id = cx.tcx.hir().local_def_id(body_owner);
+        let body_owner_def_id = cx.tcx.hir().body_owner_def_id(body.id());
 
         match cx.tcx.hir().body_owner_kind(body_owner_def_id) {
             hir::BodyOwnerKind::Static(_) | hir::BodyOwnerKind::Const => {
diff --git a/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs b/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs
index efec12489a9..849cd03dd7b 100644
--- a/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/panic_in_result_fn.rs
@@ -8,6 +8,7 @@ use rustc_hir as hir;
 use rustc_hir::intravisit::FnKind;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
@@ -49,9 +50,13 @@ impl<'tcx> LateLintPass<'tcx> for PanicInResultFn {
         _: &'tcx hir::FnDecl<'tcx>,
         body: &'tcx hir::Body<'tcx>,
         span: Span,
-        hir_id: hir::HirId,
+        def_id: LocalDefId,
     ) {
-        if !matches!(fn_kind, FnKind::Closure) && is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
+        if matches!(fn_kind, FnKind::Closure) {
+            return;
+        }
+        let owner = cx.tcx.hir().local_def_id_to_hir_id(def_id).expect_owner();
+        if is_type_diagnostic_item(cx, return_ty(cx, owner), sym::Result) {
             lint_impl_body(cx, span, body);
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs b/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
index 2d21aaa4f7f..0d78c3048ba 100644
--- a/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
+++ b/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
@@ -12,7 +12,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, Impl, ItemKind, MutTy, Mutability, Node, PatKind};
+use rustc_hir::{BindingAnnotation, Body, FnDecl, Impl, ItemKind, MutTy, Mutability, Node, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, PointerCast};
 use rustc_middle::ty::layout::LayoutOf;
@@ -143,7 +143,7 @@ impl<'tcx> PassByRefOrValue {
             return;
         }
 
-        let fn_sig = cx.tcx.fn_sig(def_id);
+        let fn_sig = cx.tcx.fn_sig(def_id).subst_identity();
         let fn_body = cx.enclosing_body.map(|id| cx.tcx.hir().body(id));
 
         // Gather all the lifetimes found in the output type which may affect whether
@@ -272,12 +272,13 @@ impl<'tcx> LateLintPass<'tcx> for PassByRefOrValue {
         decl: &'tcx FnDecl<'_>,
         _body: &'tcx Body<'_>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
         if span.from_expansion() {
             return;
         }
 
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
         match kind {
             FnKind::ItemFn(.., header) => {
                 if header.abi != Abi::Rust {
@@ -308,6 +309,6 @@ impl<'tcx> LateLintPass<'tcx> for PassByRefOrValue {
             }
         }
 
-        self.check_poly_fn(cx, cx.tcx.hir().local_def_id(hir_id), decl, Some(span));
+        self.check_poly_fn(cx, def_id, decl, Some(span));
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/pattern_type_mismatch.rs b/src/tools/clippy/clippy_lints/src/pattern_type_mismatch.rs
index 97b5a4ce364..9f98195d311 100644
--- a/src/tools/clippy/clippy_lints/src/pattern_type_mismatch.rs
+++ b/src/tools/clippy/clippy_lints/src/pattern_type_mismatch.rs
@@ -1,11 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use rustc_hir::{
-    intravisit, Body, Expr, ExprKind, FnDecl, HirId, Let, LocalSource, Mutability, Pat, PatKind, Stmt, StmtKind,
-};
+use rustc_hir::{intravisit, Body, Expr, ExprKind, FnDecl, Let, LocalSource, Mutability, Pat, PatKind, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 
 declare_clippy_lint! {
@@ -116,7 +115,7 @@ impl<'tcx> LateLintPass<'tcx> for PatternTypeMismatch {
         _: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         _: Span,
-        _: HirId,
+        _: LocalDefId,
     ) {
         for param in body.params {
             apply_lint(cx, param.pat, DerefPossible::Impossible);
diff --git a/src/tools/clippy/clippy_lints/src/ptr.rs b/src/tools/clippy/clippy_lints/src/ptr.rs
index 26295304258..8afe286fbd5 100644
--- a/src/tools/clippy/clippy_lints/src/ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/ptr.rs
@@ -164,7 +164,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
             check_mut_from_ref(cx, sig, None);
             for arg in check_fn_args(
                 cx,
-                cx.tcx.fn_sig(item.owner_id).skip_binder().inputs(),
+                cx.tcx.fn_sig(item.owner_id).subst_identity().skip_binder().inputs(),
                 sig.decl.inputs,
                 &[],
             )
@@ -217,7 +217,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
 
         check_mut_from_ref(cx, sig, Some(body));
         let decl = sig.decl;
-        let sig = cx.tcx.fn_sig(item_id).skip_binder();
+        let sig = cx.tcx.fn_sig(item_id).subst_identity().skip_binder();
         let lint_args: Vec<_> = check_fn_args(cx, sig.inputs(), decl.inputs, body.params)
             .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not)
             .collect();
@@ -624,7 +624,7 @@ fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &'tcx Body<'_>, args:
                             return;
                         };
 
-                        match *self.cx.tcx.fn_sig(id).skip_binder().inputs()[i].peel_refs().kind() {
+                        match *self.cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i].peel_refs().kind() {
                             ty::Dynamic(preds, _, _) if !matches_preds(self.cx, args.deref_ty.ty(self.cx), preds) => {
                                 set_skip_flag();
                             },
diff --git a/src/tools/clippy/clippy_lints/src/redundant_clone.rs b/src/tools/clippy/clippy_lints/src/redundant_clone.rs
index c1677fb3da1..944a33cc3e5 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_clone.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_clone.rs
@@ -6,11 +6,12 @@ use clippy_utils::{fn_has_unsatisfiable_preds, match_def_path, paths};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{def_id, Body, FnDecl, HirId, LangItem};
+use rustc_hir::{def_id, Body, FnDecl, LangItem};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::mir;
 use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::{BytePos, Span};
 use rustc_span::sym;
 
@@ -69,12 +70,10 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
         cx: &LateContext<'tcx>,
         _: FnKind<'tcx>,
         _: &'tcx FnDecl<'_>,
-        body: &'tcx Body<'_>,
+        _: &'tcx Body<'_>,
         _: Span,
-        _: HirId,
+        def_id: LocalDefId,
     ) {
-        let def_id = cx.tcx.hir().body_owner_def_id(body.id());
-
         // Building MIR for `fn`s with unsatisfiable preds results in ICE.
         if fn_has_unsatisfiable_preds(cx, def_id.to_def_id()) {
             return;
diff --git a/src/tools/clippy/clippy_lints/src/return_self_not_must_use.rs b/src/tools/clippy/clippy_lints/src/return_self_not_must_use.rs
index b77faf7322b..8c39b4fc569 100644
--- a/src/tools/clippy/clippy_lints/src/return_self_not_must_use.rs
+++ b/src/tools/clippy/clippy_lints/src/return_self_not_must_use.rs
@@ -3,7 +3,7 @@ use clippy_utils::ty::is_must_use_ty;
 use clippy_utils::{nth_arg, return_ty};
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, FnDecl, HirId, TraitItem, TraitItemKind};
+use rustc_hir::{Body, FnDecl, OwnerId, TraitItem, TraitItemKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -68,7 +68,7 @@ declare_clippy_lint! {
 
 declare_lint_pass!(ReturnSelfNotMustUse => [RETURN_SELF_NOT_MUST_USE]);
 
-fn check_method(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_def: LocalDefId, span: Span, hir_id: HirId) {
+fn check_method(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_def: LocalDefId, span: Span, owner_id: OwnerId) {
     if_chain! {
         // If it comes from an external macro, better ignore it.
         if !in_external_macro(cx.sess(), span);
@@ -76,10 +76,10 @@ fn check_method(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_def: LocalDefId, spa
         // We only show this warning for public exported methods.
         if cx.effective_visibilities.is_exported(fn_def);
         // We don't want to emit this lint if the `#[must_use]` attribute is already there.
-        if !cx.tcx.hir().attrs(hir_id).iter().any(|attr| attr.has_name(sym::must_use));
+        if !cx.tcx.hir().attrs(owner_id.into()).iter().any(|attr| attr.has_name(sym::must_use));
         if cx.tcx.visibility(fn_def.to_def_id()).is_public();
-        let ret_ty = return_ty(cx, hir_id);
-        let self_arg = nth_arg(cx, hir_id, 0);
+        let ret_ty = return_ty(cx, owner_id.into());
+        let self_arg = nth_arg(cx, owner_id.into(), 0);
         // If `Self` has the same type as the returned type, then we want to warn.
         //
         // For this check, we don't want to remove the reference on the returned type because if
@@ -109,26 +109,26 @@ impl<'tcx> LateLintPass<'tcx> for ReturnSelfNotMustUse {
         decl: &'tcx FnDecl<'tcx>,
         _: &'tcx Body<'tcx>,
         span: Span,
-        hir_id: HirId,
+        fn_def: LocalDefId,
     ) {
         if_chain! {
             // We are only interested in methods, not in functions or associated functions.
             if matches!(kind, FnKind::Method(_, _));
-            if let Some(fn_def) = cx.tcx.hir().opt_local_def_id(hir_id);
             if let Some(impl_def) = cx.tcx.impl_of_method(fn_def.to_def_id());
             // We don't want this method to be te implementation of a trait because the
             // `#[must_use]` should be put on the trait definition directly.
             if cx.tcx.trait_id_of_impl(impl_def).is_none();
 
             then {
-                check_method(cx, decl, fn_def, span, hir_id);
+                let hir_id = cx.tcx.hir().local_def_id_to_hir_id(fn_def);
+                check_method(cx, decl, fn_def, span, hir_id.expect_owner());
             }
         }
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'tcx>) {
         if let TraitItemKind::Fn(ref sig, _) = item.kind {
-            check_method(cx, sig.decl, item.owner_id.def_id, item.span, item.hir_id());
+            check_method(cx, sig.decl, item.owner_id.def_id, item.span, item.owner_id);
         }
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/returns.rs b/src/tools/clippy/clippy_lints/src/returns.rs
index bbbd9e4989e..84a0c6b9558 100644
--- a/src/tools/clippy/clippy_lints/src/returns.rs
+++ b/src/tools/clippy/clippy_lints/src/returns.rs
@@ -1,16 +1,17 @@
 use clippy_utils::diagnostics::{span_lint_and_then, span_lint_hir_and_then};
 use clippy_utils::source::{snippet_opt, snippet_with_context};
 use clippy_utils::visitors::{for_each_expr, Descend};
-use clippy_utils::{fn_def_id, path_to_local_id};
+use clippy_utils::{fn_def_id, path_to_local_id, span_find_starting_semi};
 use core::ops::ControlFlow;
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, HirId, LangItem, MatchSource, PatKind, QPath, StmtKind};
+use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, LangItem, MatchSource, PatKind, QPath, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::{BytePos, Pos};
 
@@ -151,8 +152,8 @@ impl<'tcx> LateLintPass<'tcx> for Return {
         kind: FnKind<'tcx>,
         _: &'tcx FnDecl<'tcx>,
         body: &'tcx Body<'tcx>,
-        _: Span,
-        _: HirId,
+        sp: Span,
+        _: LocalDefId,
     ) {
         match kind {
             FnKind::Closure => {
@@ -166,14 +167,14 @@ impl<'tcx> LateLintPass<'tcx> for Return {
                 check_final_expr(cx, body.value, vec![], replacement);
             },
             FnKind::ItemFn(..) | FnKind::Method(..) => {
-                check_block_return(cx, &body.value.kind, vec![]);
+                check_block_return(cx, &body.value.kind, sp, vec![]);
             },
         }
     }
 }
 
 // if `expr` is a block, check if there are needless returns in it
-fn check_block_return<'tcx>(cx: &LateContext<'tcx>, expr_kind: &ExprKind<'tcx>, semi_spans: Vec<Span>) {
+fn check_block_return<'tcx>(cx: &LateContext<'tcx>, expr_kind: &ExprKind<'tcx>, sp: Span, mut semi_spans: Vec<Span>) {
     if let ExprKind::Block(block, _) = expr_kind {
         if let Some(block_expr) = block.expr {
             check_final_expr(cx, block_expr, semi_spans, RetReplacement::Empty);
@@ -183,12 +184,14 @@ fn check_block_return<'tcx>(cx: &LateContext<'tcx>, expr_kind: &ExprKind<'tcx>,
                     check_final_expr(cx, expr, semi_spans, RetReplacement::Empty);
                 },
                 StmtKind::Semi(semi_expr) => {
-                    let mut semi_spans_and_this_one = semi_spans;
-                    // we only want the span containing the semicolon so we can remove it later. From `entry.rs:382`
-                    if let Some(semicolon_span) = stmt.span.trim_start(semi_expr.span) {
-                        semi_spans_and_this_one.push(semicolon_span);
-                        check_final_expr(cx, semi_expr, semi_spans_and_this_one, RetReplacement::Empty);
+                    // Remove ending semicolons and any whitespace ' ' in between.
+                    // Without `return`, the suggestion might not compile if the semicolon is retained
+                    if let Some(semi_span) = stmt.span.trim_start(semi_expr.span) {
+                        let semi_span_to_remove =
+                            span_find_starting_semi(cx.sess().source_map(), semi_span.with_hi(sp.hi()));
+                        semi_spans.push(semi_span_to_remove);
                     }
+                    check_final_expr(cx, semi_expr, semi_spans, RetReplacement::Empty);
                 },
                 _ => (),
             }
@@ -231,9 +234,9 @@ fn check_final_expr<'tcx>(
             emit_return_lint(cx, ret_span, semi_spans, inner.as_ref().map(|i| i.span), replacement);
         },
         ExprKind::If(_, then, else_clause_opt) => {
-            check_block_return(cx, &then.kind, semi_spans.clone());
+            check_block_return(cx, &then.kind, peeled_drop_expr.span, semi_spans.clone());
             if let Some(else_clause) = else_clause_opt {
-                check_block_return(cx, &else_clause.kind, semi_spans);
+                check_block_return(cx, &else_clause.kind, peeled_drop_expr.span, semi_spans);
             }
         },
         // a match expr, check all arms
@@ -246,7 +249,7 @@ fn check_final_expr<'tcx>(
             }
         },
         // if it's a whole block, check it
-        other_expr_kind => check_block_return(cx, other_expr_kind, semi_spans),
+        other_expr_kind => check_block_return(cx, other_expr_kind, peeled_drop_expr.span, semi_spans),
     }
 }
 
@@ -288,6 +291,7 @@ fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>)
             && cx
                 .tcx
                 .fn_sig(def_id)
+                .subst_identity()
                 .skip_binder()
                 .output()
                 .walk()
diff --git a/src/tools/clippy/clippy_lints/src/self_named_constructors.rs b/src/tools/clippy/clippy_lints/src/self_named_constructors.rs
index 71b387c66a3..3ce030cd721 100644
--- a/src/tools/clippy/clippy_lints/src/self_named_constructors.rs
+++ b/src/tools/clippy/clippy_lints/src/self_named_constructors.rs
@@ -54,7 +54,7 @@ impl<'tcx> LateLintPass<'tcx> for SelfNamedConstructors {
         let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id()).def_id;
         let item = cx.tcx.hir().expect_item(parent);
         let self_ty = cx.tcx.type_of(item.owner_id);
-        let ret_ty = return_ty(cx, impl_item.hir_id());
+        let ret_ty = return_ty(cx, impl_item.owner_id);
 
         // Do not check trait impls
         if matches!(item.kind, ItemKind::Impl(Impl { of_trait: Some(_), .. })) {
diff --git a/src/tools/clippy/clippy_lints/src/suspicious_xor_used_as_pow.rs b/src/tools/clippy/clippy_lints/src/suspicious_xor_used_as_pow.rs
index 301aa5798bf..9c0dc8096d0 100644
--- a/src/tools/clippy/clippy_lints/src/suspicious_xor_used_as_pow.rs
+++ b/src/tools/clippy/clippy_lints/src/suspicious_xor_used_as_pow.rs
@@ -9,7 +9,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Warns for a Bitwise XOR (`^`) operator being probably confused as a powering. It will not trigger if any of the numbers are not in decimal.
     /// ### Why is this bad?
-    ///	It's most probably a typo and may lead to unexpected behaviours.
+    /// It's most probably a typo and may lead to unexpected behaviours.
     /// ### Example
     /// ```rust
     /// let x = 3_i32 ^ 4_i32;
@@ -18,7 +18,7 @@ declare_clippy_lint! {
     /// ```rust
     /// let x = 3_i32.pow(4);
     /// ```
-    #[clippy::version = "1.66.0"]
+    #[clippy::version = "1.67.0"]
     pub SUSPICIOUS_XOR_USED_AS_POW,
     restriction,
     "XOR (`^`) operator possibly used as exponentiation operator"
diff --git a/src/tools/clippy/clippy_lints/src/trailing_empty_array.rs b/src/tools/clippy/clippy_lints/src/trailing_empty_array.rs
index 63b326048a4..de0c5d56e41 100644
--- a/src/tools/clippy/clippy_lints/src/trailing_empty_array.rs
+++ b/src/tools/clippy/clippy_lints/src/trailing_empty_array.rs
@@ -61,8 +61,7 @@ fn is_struct_with_trailing_zero_sized_array(cx: &LateContext<'_>, item: &Item<'_
         if let rustc_hir::TyKind::Array(_, rustc_hir::ArrayLen::Body(length)) = last_field.ty.kind;
 
         // Then check if that that array zero-sized
-        let length_ldid = cx.tcx.hir().local_def_id(length.hir_id);
-        let length = Const::from_anon_const(cx.tcx, length_ldid);
+        let length = Const::from_anon_const(cx.tcx, length.def_id);
         let length = length.try_eval_usize(cx.tcx, cx.param_env);
         if let Some(length) = length;
         then {
diff --git a/src/tools/clippy/clippy_lints/src/transmute/mod.rs b/src/tools/clippy/clippy_lints/src/transmute/mod.rs
index 691d759d773..c0d290b5adc 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/mod.rs
@@ -479,7 +479,10 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                 // - char conversions (https://github.com/rust-lang/rust/issues/89259)
                 let const_context = in_constant(cx, e.hir_id);
 
-                let from_ty = cx.typeck_results().expr_ty_adjusted(arg);
+                let (from_ty, from_ty_adjusted) = match cx.typeck_results().expr_adjustments(arg) {
+                    [] => (cx.typeck_results().expr_ty(arg), false),
+                    [.., a] => (a.target, true),
+                };
                 // Adjustments for `to_ty` happen after the call to `transmute`, so don't use them.
                 let to_ty = cx.typeck_results().expr_ty(e);
 
@@ -506,7 +509,7 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                     );
 
                 if !linted {
-                    transmutes_expressible_as_ptr_casts::check(cx, e, from_ty, to_ty, arg);
+                    transmutes_expressible_as_ptr_casts::check(cx, e, from_ty, from_ty_adjusted, to_ty, arg);
                 }
             }
         }
diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs b/src/tools/clippy/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs
index b79d4e915a2..8530b43243f 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs
@@ -1,11 +1,11 @@
-use super::utils::can_be_expressed_as_pointer_cast;
+use super::utils::check_cast;
 use super::TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS;
-use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::sugg;
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::sugg::Sugg;
 use rustc_errors::Applicability;
 use rustc_hir::Expr;
 use rustc_lint::LateContext;
-use rustc_middle::ty::Ty;
+use rustc_middle::ty::{cast::CastKind, Ty};
 
 /// Checks for `transmutes_expressible_as_ptr_casts` lint.
 /// Returns `true` if it's triggered, otherwise returns `false`.
@@ -13,24 +13,40 @@ pub(super) fn check<'tcx>(
     cx: &LateContext<'tcx>,
     e: &'tcx Expr<'_>,
     from_ty: Ty<'tcx>,
+    from_ty_adjusted: bool,
     to_ty: Ty<'tcx>,
     arg: &'tcx Expr<'_>,
 ) -> bool {
-    if can_be_expressed_as_pointer_cast(cx, e, from_ty, to_ty) {
-        span_lint_and_then(
-            cx,
-            TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS,
-            e.span,
-            &format!("transmute from `{from_ty}` to `{to_ty}` which could be expressed as a pointer cast instead"),
-            |diag| {
-                if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
-                    let sugg = arg.as_ty(to_ty.to_string()).to_string();
-                    diag.span_suggestion(e.span, "try", sugg, Applicability::MachineApplicable);
-                }
-            },
-        );
-        true
-    } else {
-        false
-    }
+    use CastKind::{AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast};
+    let mut app = Applicability::MachineApplicable;
+    let sugg = match check_cast(cx, e, from_ty, to_ty) {
+        Some(PtrPtrCast | AddrPtrCast | ArrayPtrCast | FnPtrPtrCast | FnPtrAddrCast) => {
+            Sugg::hir_with_context(cx, arg, e.span.ctxt(), "..", &mut app)
+                .as_ty(to_ty.to_string())
+                .to_string()
+        },
+        Some(PtrAddrCast) if !from_ty_adjusted => Sugg::hir_with_context(cx, arg, e.span.ctxt(), "..", &mut app)
+            .as_ty(to_ty.to_string())
+            .to_string(),
+
+        // The only adjustments here would be ref-to-ptr and unsize coercions. The result of an unsize coercions can't
+        // be transmuted to a usize. For ref-to-ptr coercions, borrows need to be cast to a pointer before being cast to
+        // a usize.
+        Some(PtrAddrCast) => format!(
+            "{} as {to_ty}",
+            Sugg::hir_with_context(cx, arg, e.span.ctxt(), "..", &mut app).as_ty(from_ty)
+        ),
+        _ => return false,
+    };
+
+    span_lint_and_sugg(
+        cx,
+        TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS,
+        e.span,
+        &format!("transmute from `{from_ty}` to `{to_ty}` which could be expressed as a pointer cast instead"),
+        "try",
+        sugg,
+        app,
+    );
+    true
 }
diff --git a/src/tools/clippy/clippy_lints/src/transmute/utils.rs b/src/tools/clippy/clippy_lints/src/transmute/utils.rs
index 49d863ec03f..cddaf9450ea 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/utils.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/utils.rs
@@ -20,33 +20,21 @@ pub(super) fn is_layout_incompatible<'tcx>(cx: &LateContext<'tcx>, from: Ty<'tcx
     }
 }
 
-/// Check if the type conversion can be expressed as a pointer cast, instead of
-/// a transmute. In certain cases, including some invalid casts from array
-/// references to pointers, this may cause additional errors to be emitted and/or
-/// ICE error messages. This function will panic if that occurs.
-pub(super) fn can_be_expressed_as_pointer_cast<'tcx>(
-    cx: &LateContext<'tcx>,
-    e: &'tcx Expr<'_>,
-    from_ty: Ty<'tcx>,
-    to_ty: Ty<'tcx>,
-) -> bool {
-    use CastKind::{AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast};
-    matches!(
-        check_cast(cx, e, from_ty, to_ty),
-        Some(PtrPtrCast | PtrAddrCast | AddrPtrCast | ArrayPtrCast | FnPtrPtrCast | FnPtrAddrCast)
-    )
-}
-
 /// If a cast from `from_ty` to `to_ty` is valid, returns an Ok containing the kind of
 /// the cast. In certain cases, including some invalid casts from array references
 /// to pointers, this may cause additional errors to be emitted and/or ICE error
 /// messages. This function will panic if that occurs.
-fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> Option<CastKind> {
+pub(super) fn check_cast<'tcx>(
+    cx: &LateContext<'tcx>,
+    e: &'tcx Expr<'_>,
+    from_ty: Ty<'tcx>,
+    to_ty: Ty<'tcx>,
+) -> Option<CastKind> {
     let hir_id = e.hir_id;
     let local_def_id = hir_id.owner.def_id;
 
     Inherited::build(cx.tcx, local_def_id).enter(|inherited| {
-        let fn_ctxt = FnCtxt::new(inherited, cx.param_env, hir_id);
+        let fn_ctxt = FnCtxt::new(inherited, cx.param_env, local_def_id);
 
         // If we already have errors, we can't be sure we can pointer cast.
         assert!(
diff --git a/src/tools/clippy/clippy_lints/src/types/mod.rs b/src/tools/clippy/clippy_lints/src/types/mod.rs
index 229478b7ce3..585e2075fa9 100644
--- a/src/tools/clippy/clippy_lints/src/types/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/types/mod.rs
@@ -12,11 +12,12 @@ mod vec_box;
 use rustc_hir as hir;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
-    Body, FnDecl, FnRetTy, GenericArg, HirId, ImplItem, ImplItemKind, Item, ItemKind, Local, MutTy, QPath, TraitItem,
+    Body, FnDecl, FnRetTy, GenericArg, ImplItem, ImplItemKind, Item, ItemKind, Local, MutTy, QPath, TraitItem,
     TraitItemKind, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 
 declare_clippy_lint! {
@@ -311,15 +312,27 @@ pub struct Types {
 impl_lint_pass!(Types => [BOX_COLLECTION, VEC_BOX, OPTION_OPTION, LINKEDLIST, BORROWED_BOX, REDUNDANT_ALLOCATION, RC_BUFFER, RC_MUTEX, TYPE_COMPLEXITY]);
 
 impl<'tcx> LateLintPass<'tcx> for Types {
-    fn check_fn(&mut self, cx: &LateContext<'_>, _: FnKind<'_>, decl: &FnDecl<'_>, _: &Body<'_>, _: Span, id: HirId) {
-        let is_in_trait_impl =
-            if let Some(hir::Node::Item(item)) = cx.tcx.hir().find_by_def_id(cx.tcx.hir().get_parent_item(id).def_id) {
-                matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
-            } else {
-                false
-            };
+    fn check_fn(
+        &mut self,
+        cx: &LateContext<'_>,
+        _: FnKind<'_>,
+        decl: &FnDecl<'_>,
+        _: &Body<'_>,
+        _: Span,
+        def_id: LocalDefId,
+    ) {
+        let is_in_trait_impl = if let Some(hir::Node::Item(item)) = cx.tcx.hir().find_by_def_id(
+            cx.tcx
+                .hir()
+                .get_parent_item(cx.tcx.hir().local_def_id_to_hir_id(def_id))
+                .def_id,
+        ) {
+            matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
+        } else {
+            false
+        };
 
-        let is_exported = cx.effective_visibilities.is_exported(cx.tcx.hir().local_def_id(id));
+        let is_exported = cx.effective_visibilities.is_exported(def_id);
 
         self.check_fn_decl(
             cx,
@@ -381,7 +394,7 @@ impl<'tcx> LateLintPass<'tcx> for Types {
     fn check_field_def(&mut self, cx: &LateContext<'_>, field: &hir::FieldDef<'_>) {
         let is_exported = cx
             .effective_visibilities
-            .is_exported(cx.tcx.hir().local_def_id(field.hir_id));
+            .is_exported(field.def_id);
 
         self.check_ty(
             cx,
diff --git a/src/tools/clippy/clippy_lints/src/undocumented_unsafe_blocks.rs b/src/tools/clippy/clippy_lints/src/undocumented_unsafe_blocks.rs
index 2e1b6d8d4ea..2920684ade3 100644
--- a/src/tools/clippy/clippy_lints/src/undocumented_unsafe_blocks.rs
+++ b/src/tools/clippy/clippy_lints/src/undocumented_unsafe_blocks.rs
@@ -263,6 +263,18 @@ fn expr_has_unnecessary_safety_comment<'tcx>(
     expr: &'tcx hir::Expr<'tcx>,
     comment_pos: BytePos,
 ) -> Option<Span> {
+    if cx.tcx.hir().parent_iter(expr.hir_id).any(|(_, ref node)| {
+        matches!(
+            node,
+            Node::Block(&Block {
+                rules: BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
+                ..
+            }),
+        )
+    }) {
+        return None;
+    }
+
     // this should roughly be the reverse of `block_parents_have_safety_comment`
     if for_each_expr_with_closures(cx, expr, |expr| match expr.kind {
         hir::ExprKind::Block(
diff --git a/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs b/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
index a138a4baa9b..289ca4e9bed 100644
--- a/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
+++ b/src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
@@ -76,7 +76,7 @@ fn get_projection_pred<'tcx>(
 fn get_args_to_check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Vec<(usize, String)> {
     let mut args_to_check = Vec::new();
     if let Some(def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) {
-        let fn_sig = cx.tcx.fn_sig(def_id);
+        let fn_sig = cx.tcx.fn_sig(def_id).subst_identity();
         let generics = cx.tcx.predicates_of(def_id);
         let fn_mut_preds = get_trait_predicates_for_trait_id(cx, generics, cx.tcx.lang_items().fn_mut_trait());
         let ord_preds = get_trait_predicates_for_trait_id(cx, generics, cx.tcx.get_diagnostic_item(sym::Ord));
diff --git a/src/tools/clippy/clippy_lints/src/unit_types/let_unit_value.rs b/src/tools/clippy/clippy_lints/src/unit_types/let_unit_value.rs
index ce9ebad8c89..d6167a62169 100644
--- a/src/tools/clippy/clippy_lints/src/unit_types/let_unit_value.rs
+++ b/src/tools/clippy/clippy_lints/src/unit_types/let_unit_value.rs
@@ -156,7 +156,7 @@ fn needs_inferred_result_ty(
         },
         _ => return false,
     };
-    let sig = cx.tcx.fn_sig(id).skip_binder();
+    let sig = cx.tcx.fn_sig(id).subst_identity().skip_binder();
     if let ty::Param(output_ty) = *sig.output().kind() {
         let args: Vec<&Expr<'_>> = if let Some(receiver) = receiver {
             std::iter::once(receiver).chain(args.iter()).collect()
diff --git a/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs b/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
index 84ec0d0fb1c..8b0e0ce5a30 100644
--- a/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
+++ b/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
@@ -5,10 +5,11 @@ use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::LangItem::{OptionSome, ResultOk};
-use rustc_hir::{Body, ExprKind, FnDecl, HirId, Impl, ItemKind, Node};
+use rustc_hir::{Body, ExprKind, FnDecl, Impl, ItemKind, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 
@@ -77,12 +78,11 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWraps {
         fn_decl: &FnDecl<'tcx>,
         body: &Body<'tcx>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
         // Abort if public function/method or closure.
         match fn_kind {
             FnKind::ItemFn(..) | FnKind::Method(..) => {
-                let def_id = cx.tcx.hir().local_def_id(hir_id);
                 if self.avoid_breaking_exported_api && cx.effective_visibilities.is_exported(def_id) {
                     return;
                 }
@@ -91,6 +91,7 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWraps {
         }
 
         // Abort if the method is implementing a trait or of it a trait method.
+        let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
         if let Some(Node::Item(item)) = cx.tcx.hir().find_parent(hir_id) {
             if matches!(
                 item.kind,
@@ -101,17 +102,18 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWraps {
         }
 
         // Get the wrapper and inner types, if can't, abort.
-        let (return_type_label, lang_item, inner_type) = if let ty::Adt(adt_def, subst) = return_ty(cx, hir_id).kind() {
-            if cx.tcx.is_diagnostic_item(sym::Option, adt_def.did()) {
-                ("Option", OptionSome, subst.type_at(0))
-            } else if cx.tcx.is_diagnostic_item(sym::Result, adt_def.did()) {
-                ("Result", ResultOk, subst.type_at(0))
+        let (return_type_label, lang_item, inner_type) =
+            if let ty::Adt(adt_def, subst) = return_ty(cx, hir_id.expect_owner()).kind() {
+                if cx.tcx.is_diagnostic_item(sym::Option, adt_def.did()) {
+                    ("Option", OptionSome, subst.type_at(0))
+                } else if cx.tcx.is_diagnostic_item(sym::Result, adt_def.did()) {
+                    ("Result", ResultOk, subst.type_at(0))
+                } else {
+                    return;
+                }
             } else {
                 return;
-            }
-        } else {
-            return;
-        };
+            };
 
         // Check if all return expression respect the following condition and collect them.
         let mut suggs = Vec::new();
diff --git a/src/tools/clippy/clippy_lints/src/unused_async.rs b/src/tools/clippy/clippy_lints/src/unused_async.rs
index 3538bef6e06..55651a28be9 100644
--- a/src/tools/clippy/clippy_lints/src/unused_async.rs
+++ b/src/tools/clippy/clippy_lints/src/unused_async.rs
@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use rustc_hir::intravisit::{walk_expr, walk_fn, FnKind, Visitor};
-use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId, YieldSource};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, YieldSource};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 
 declare_clippy_lint! {
@@ -66,11 +67,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedAsync {
         fn_decl: &'tcx FnDecl<'tcx>,
         body: &Body<'tcx>,
         span: Span,
-        hir_id: HirId,
+        def_id: LocalDefId,
     ) {
         if !span.from_expansion() && fn_kind.asyncness().is_async() {
             let mut visitor = AsyncFnVisitor { cx, found_await: false };
-            walk_fn(&mut visitor, fn_kind, fn_decl, body.id(), hir_id);
+            walk_fn(&mut visitor, fn_kind, fn_decl, body.id(), def_id);
             if !visitor.found_await {
                 span_lint_and_help(
                     cx,
diff --git a/src/tools/clippy/clippy_lints/src/unwrap.rs b/src/tools/clippy/clippy_lints/src/unwrap.rs
index ea878043c04..377d3fb6f4e 100644
--- a/src/tools/clippy/clippy_lints/src/unwrap.rs
+++ b/src/tools/clippy/clippy_lints/src/unwrap.rs
@@ -11,6 +11,7 @@ use rustc_middle::hir::nested_filter;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::Ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::sym;
 
@@ -312,7 +313,7 @@ impl<'tcx> LateLintPass<'tcx> for Unwrap {
         decl: &'tcx FnDecl<'_>,
         body: &'tcx Body<'_>,
         span: Span,
-        fn_id: HirId,
+        fn_id: LocalDefId,
     ) {
         if span.from_expansion() {
             return;
diff --git a/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs b/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
index f3611d17434..3a1845425a2 100644
--- a/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
+++ b/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
@@ -64,8 +64,8 @@ impl<'tcx> LateLintPass<'tcx> for UnwrapInResult {
             // first check if it's a method or function
             if let hir::ImplItemKind::Fn(ref _signature, _) = impl_item.kind;
             // checking if its return type is `result` or `option`
-            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::Result)
-                || is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::Option);
+            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.owner_id), sym::Result)
+                || is_type_diagnostic_item(cx, return_ty(cx, impl_item.owner_id), sym::Option);
             then {
                 lint_impl_body(cx, impl_item.span, impl_item);
             }
diff --git a/src/tools/clippy/clippy_lints/src/use_self.rs b/src/tools/clippy/clippy_lints/src/use_self.rs
index 6ae9d9d6353..3cd35838961 100644
--- a/src/tools/clippy/clippy_lints/src/use_self.rs
+++ b/src/tools/clippy/clippy_lints/src/use_self.rs
@@ -146,7 +146,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                     .associated_item(impl_item.owner_id)
                     .trait_item_def_id
                     .expect("impl method matches a trait method");
-                let trait_method_sig = cx.tcx.fn_sig(trait_method);
+                let trait_method_sig = cx.tcx.fn_sig(trait_method).subst_identity();
                 let trait_method_sig = cx.tcx.erase_late_bound_regions(trait_method_sig);
 
                 // `impl_inputs_outputs` is an iterator over the types (`hir::Ty`) declared in the
diff --git a/src/tools/clippy/clippy_lints/src/utils/conf.rs b/src/tools/clippy/clippy_lints/src/utils/conf.rs
index c1589c771c4..f48be27592b 100644
--- a/src/tools/clippy/clippy_lints/src/utils/conf.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/conf.rs
@@ -219,7 +219,8 @@ define_Conf! {
     ///
     /// #### Noteworthy
     ///
-    /// A type, say `SomeType`, listed in this configuration has the same behavior of `["SomeType" , "*"], ["*", "SomeType"]` in `arithmetic_side_effects_allowed_binary`.
+    /// A type, say `SomeType`, listed in this configuration has the same behavior of
+    /// `["SomeType" , "*"], ["*", "SomeType"]` in `arithmetic_side_effects_allowed_binary`.
     (arithmetic_side_effects_allowed: rustc_data_structures::fx::FxHashSet<String> = <_>::default()),
     /// Lint: ARITHMETIC_SIDE_EFFECTS.
     ///
diff --git a/src/tools/clippy/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/src/tools/clippy/clippy_lints/src/utils/internal_lints/metadata_collector.rs
index c4d8c28f060..b1b5164ffb3 100644
--- a/src/tools/clippy/clippy_lints/src/utils/internal_lints/metadata_collector.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -14,6 +14,7 @@ use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
 use clippy_utils::{last_path_segment, match_def_path, match_function_call, match_path, paths};
 use if_chain::if_chain;
+use itertools::Itertools;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::{
@@ -34,8 +35,10 @@ use std::path::Path;
 use std::path::PathBuf;
 use std::process::Command;
 
-/// This is the output file of the lint collector.
-const OUTPUT_FILE: &str = "../util/gh-pages/lints.json";
+/// This is the json output file of the lint collector.
+const JSON_OUTPUT_FILE: &str = "../util/gh-pages/lints.json";
+/// This is the markdown output file of the lint collector.
+const MARKDOWN_OUTPUT_FILE: &str = "../book/src/lint_configuration.md";
 /// These lints are excluded from the export.
 const BLACK_LISTED_LINTS: &[&str] = &["lint_author", "dump_hir", "internal_metadata_collector"];
 /// These groups will be ignored by the lint group matcher. This is useful for collections like
@@ -176,6 +179,23 @@ This lint has the following configuration variables:
                 )
             })
     }
+
+    fn configs_to_markdown(&self, map_fn: fn(&ClippyConfiguration) -> String) -> String {
+        self.config
+            .iter()
+            .filter(|config| config.deprecation_reason.is_none())
+            .filter(|config| !config.lints.is_empty())
+            .map(map_fn)
+            .join("\n")
+    }
+
+    fn get_markdown_docs(&self) -> String {
+        format!(
+            "## Lint Configuration Options\n| <div style=\"width:290px\">Option</div> | Default Value |\n|--|--|\n{}\n\n{}\n",
+            self.configs_to_markdown(ClippyConfiguration::to_markdown_table_entry),
+            self.configs_to_markdown(ClippyConfiguration::to_markdown_paragraph),
+        )
+    }
 }
 
 impl Drop for MetadataCollector {
@@ -199,12 +219,37 @@ impl Drop for MetadataCollector {
 
         collect_renames(&mut lints);
 
-        // Outputting
-        if Path::new(OUTPUT_FILE).exists() {
-            fs::remove_file(OUTPUT_FILE).unwrap();
+        // Outputting json
+        if Path::new(JSON_OUTPUT_FILE).exists() {
+            fs::remove_file(JSON_OUTPUT_FILE).unwrap();
         }
-        let mut file = OpenOptions::new().write(true).create(true).open(OUTPUT_FILE).unwrap();
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create(true)
+            .open(JSON_OUTPUT_FILE)
+            .unwrap();
         writeln!(file, "{}", serde_json::to_string_pretty(&lints).unwrap()).unwrap();
+
+        // Outputting markdown
+        if Path::new(MARKDOWN_OUTPUT_FILE).exists() {
+            fs::remove_file(MARKDOWN_OUTPUT_FILE).unwrap();
+        }
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create(true)
+            .open(MARKDOWN_OUTPUT_FILE)
+            .unwrap();
+        writeln!(
+            file,
+            "<!--
+This file is generated by `cargo collect-metadata`.
+Please use that command to update the file and do not edit it by hand.
+-->
+
+{}",
+            self.get_markdown_docs(),
+        )
+        .unwrap();
     }
 }
 
@@ -505,6 +550,28 @@ impl ClippyConfiguration {
             deprecation_reason,
         }
     }
+
+    fn to_markdown_paragraph(&self) -> String {
+        format!(
+            "### {}\n{}\n\n**Default Value:** `{}` (`{}`)\n\n{}\n\n",
+            self.name,
+            self.doc
+                .lines()
+                .map(|line| line.strip_prefix("    ").unwrap_or(line))
+                .join("\n"),
+            self.default,
+            self.config_type,
+            self.lints
+                .iter()
+                .map(|name| name.to_string().split_whitespace().next().unwrap().to_string())
+                .map(|name| format!("* [{name}](https://rust-lang.github.io/rust-clippy/master/index.html#{name})"))
+                .join("\n"),
+        )
+    }
+
+    fn to_markdown_table_entry(&self) -> String {
+        format!("| [{}](#{}) | `{}` |", self.name, self.name, self.default)
+    }
 }
 
 fn collect_configs() -> Vec<ClippyConfiguration> {
diff --git a/src/tools/clippy/clippy_utils/Cargo.toml b/src/tools/clippy/clippy_utils/Cargo.toml
index ac6a566b9cd..173469f6cdc 100644
--- a/src/tools/clippy/clippy_utils/Cargo.toml
+++ b/src/tools/clippy/clippy_utils/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy_utils"
-version = "0.1.68"
+version = "0.1.69"
 edition = "2021"
 publish = false
 
diff --git a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
index 96711936968..5c89dd3e49f 100644
--- a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
+++ b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
@@ -79,7 +79,7 @@ fn fn_eagerness(cx: &LateContext<'_>, fn_id: DefId, name: Symbol, have_one_arg:
             && subs.types().all(|x| matches!(x.peel_refs().kind(), ty::Param(_)))
         {
             // Limit the function to either `(self) -> bool` or `(&self) -> bool`
-            match &**cx.tcx.fn_sig(fn_id).skip_binder().inputs_and_output {
+            match &**cx.tcx.fn_sig(fn_id).subst_identity().skip_binder().inputs_and_output {
                 [arg, res] if !arg.is_mutable_ptr() && arg.peel_refs() == ty && res.is_bool() => NoChange,
                 _ => Lazy,
             }
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 7a4a9036dd3..26f279f5585 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -1,6 +1,5 @@
 #![feature(array_chunks)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(let_chains)]
 #![feature(lint_reasons)]
 #![feature(never_type)]
@@ -1119,9 +1118,8 @@ pub fn can_move_expr_to_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'
                         self.captures.entry(l).and_modify(|e| *e |= cap).or_insert(cap);
                     }
                 },
-                ExprKind::Closure { .. } => {
-                    let closure_id = self.cx.tcx.hir().local_def_id(e.hir_id);
-                    for capture in self.cx.typeck_results().closure_min_captures_flattened(closure_id) {
+                ExprKind::Closure(closure) => {
+                    for capture in self.cx.typeck_results().closure_min_captures_flattened(closure.def_id) {
                         let local_id = match capture.place.base {
                             PlaceBase::Local(id) => id,
                             PlaceBase::Upvar(var) => var.var_path.hir_id,
@@ -1379,7 +1377,7 @@ pub fn get_enclosing_loop_or_multi_call_closure<'tcx>(
                                     .chain(args.iter())
                                     .position(|arg| arg.hir_id == id)?;
                                 let id = cx.typeck_results().type_dependent_def_id(e.hir_id)?;
-                                let ty = cx.tcx.fn_sig(id).skip_binder().inputs()[i];
+                                let ty = cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i];
                                 ty_is_fn_once_param(cx.tcx, ty, cx.tcx.param_env(id).caller_bounds()).then_some(())
                             },
                             _ => None,
@@ -1578,16 +1576,14 @@ pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> {
 }
 
 /// Convenience function to get the return type of a function.
-pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> {
-    let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
-    let ret_ty = cx.tcx.fn_sig(fn_def_id).output();
+pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_def_id: hir::OwnerId) -> Ty<'tcx> {
+    let ret_ty = cx.tcx.fn_sig(fn_def_id).subst_identity().output();
     cx.tcx.erase_late_bound_regions(ret_ty)
 }
 
 /// Convenience function to get the nth argument type of a function.
-pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId, nth: usize) -> Ty<'tcx> {
-    let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
-    let arg = cx.tcx.fn_sig(fn_def_id).input(nth);
+pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_def_id: hir::OwnerId, nth: usize) -> Ty<'tcx> {
+    let arg = cx.tcx.fn_sig(fn_def_id).subst_identity().input(nth);
     cx.tcx.erase_late_bound_regions(arg)
 }
 
@@ -2491,6 +2487,10 @@ pub fn span_extract_comment(sm: &SourceMap, span: Span) -> String {
     comments_buf.join("\n")
 }
 
+pub fn span_find_starting_semi(sm: &SourceMap, span: Span) -> Span {
+    sm.span_take_while(span, |&ch| ch == ' ' || ch == ';')
+}
+
 macro_rules! op_utils {
     ($($name:ident $assign:ident)*) => {
         /// Binary operation traits like `LangItem::Add`
diff --git a/src/tools/clippy/clippy_utils/src/macros.rs b/src/tools/clippy/clippy_utils/src/macros.rs
index 77c5f115542..d7f466c1976 100644
--- a/src/tools/clippy/clippy_utils/src/macros.rs
+++ b/src/tools/clippy/clippy_utils/src/macros.rs
@@ -1,6 +1,5 @@
 #![allow(clippy::similar_names)] // `expr` and `expn`
 
-use crate::is_path_diagnostic_item;
 use crate::source::snippet_opt;
 use crate::visitors::{for_each_expr, Descend};
 
@@ -8,7 +7,7 @@ use arrayvec::ArrayVec;
 use itertools::{izip, Either, Itertools};
 use rustc_ast::ast::LitKind;
 use rustc_hir::intravisit::{walk_expr, Visitor};
-use rustc_hir::{self as hir, Expr, ExprField, ExprKind, HirId, Node, QPath};
+use rustc_hir::{self as hir, Expr, ExprField, ExprKind, HirId, LangItem, Node, QPath, TyKind};
 use rustc_lexer::unescape::unescape_literal;
 use rustc_lexer::{tokenize, unescape, LiteralKind, TokenKind};
 use rustc_lint::LateContext;
@@ -328,7 +327,7 @@ fn is_assert_arg(cx: &LateContext<'_>, expr: &Expr<'_>, assert_expn: ExpnId) ->
         } else {
             match cx.tcx.item_name(macro_call.def_id) {
                 // `cfg!(debug_assertions)` in `debug_assert!`
-                sym::cfg => ControlFlow::CONTINUE,
+                sym::cfg => ControlFlow::Continue(()),
                 // assert!(other_macro!(..))
                 _ => ControlFlow::Break(true),
             }
@@ -439,8 +438,7 @@ impl<'tcx> FormatArgsValues<'tcx> {
                 // ArgumentV1::from_usize(<val>)
                 if let ExprKind::Call(callee, [val]) = expr.kind
                     && let ExprKind::Path(QPath::TypeRelative(ty, _)) = callee.kind
-                    && let hir::TyKind::Path(QPath::Resolved(_, path)) = ty.kind
-                    && path.segments.last().unwrap().ident.name == sym::ArgumentV1
+                    && let TyKind::Path(QPath::LangItem(LangItem::FormatArgument, _, _)) = ty.kind
                 {
                     let val_idx = if val.span.ctxt() == expr.span.ctxt()
                         && let ExprKind::Field(_, field) = val.kind
@@ -486,20 +484,6 @@ struct ParamPosition {
 
 impl<'tcx> Visitor<'tcx> for ParamPosition {
     fn visit_expr_field(&mut self, field: &'tcx ExprField<'tcx>) {
-        fn parse_count(expr: &Expr<'_>) -> Option<usize> {
-            // ::core::fmt::rt::v1::Count::Param(1usize),
-            if let ExprKind::Call(ctor, [val]) = expr.kind
-                && let ExprKind::Path(QPath::Resolved(_, path)) = ctor.kind
-                && path.segments.last()?.ident.name == sym::Param
-                && let ExprKind::Lit(lit) = &val.kind
-                && let LitKind::Int(pos, _) = lit.node
-            {
-                Some(pos as usize)
-            } else {
-                None
-            }
-        }
-
         match field.ident.name {
             sym::position => {
                 if let ExprKind::Lit(lit) = &field.expr.kind
@@ -519,15 +503,41 @@ impl<'tcx> Visitor<'tcx> for ParamPosition {
     }
 }
 
+fn parse_count(expr: &Expr<'_>) -> Option<usize> {
+    // <::core::fmt::rt::v1::Count>::Param(1usize),
+    if let ExprKind::Call(ctor, [val]) = expr.kind
+        && let ExprKind::Path(QPath::TypeRelative(_, path)) = ctor.kind
+            && path.ident.name == sym::Param
+            && let ExprKind::Lit(lit) = &val.kind
+            && let LitKind::Int(pos, _) = lit.node
+    {
+        Some(pos as usize)
+    } else {
+        None
+    }
+}
+
 /// Parses the `fmt` arg of `Arguments::new_v1_formatted(pieces, args, fmt, _)`
 fn parse_rt_fmt<'tcx>(fmt_arg: &'tcx Expr<'tcx>) -> Option<impl Iterator<Item = ParamPosition> + 'tcx> {
     if let ExprKind::AddrOf(.., array) = fmt_arg.kind
         && let ExprKind::Array(specs) = array.kind
     {
         Some(specs.iter().map(|spec| {
-            let mut position = ParamPosition::default();
-            position.visit_expr(spec);
-            position
+            if let ExprKind::Call(f, args) = spec.kind
+                && let ExprKind::Path(QPath::TypeRelative(ty, f)) = f.kind
+                && let TyKind::Path(QPath::LangItem(LangItem::FormatPlaceholder, _, _)) = ty.kind
+                && f.ident.name == sym::new
+                && let [position, _fill, _align, _flags, precision, width] = args
+                && let ExprKind::Lit(position) = &position.kind
+                && let LitKind::Int(position, _) = position.node {
+                    ParamPosition {
+                        value: position as usize,
+                        width: parse_count(width),
+                        precision: parse_count(precision),
+                    }
+            } else {
+                ParamPosition::default()
+            }
         }))
     } else {
         None
@@ -701,8 +711,8 @@ pub struct FormatSpec<'tcx> {
     pub fill: Option<char>,
     /// Optionally specified alignment.
     pub align: Alignment,
-    /// Packed version of various flags provided, see [`rustc_parse_format::Flag`].
-    pub flags: u32,
+    /// Whether all flag options are set to default (no flags specified).
+    pub no_flags: bool,
     /// Represents either the maximum width or the integer precision.
     pub precision: Count<'tcx>,
     /// The minimum width, will be padded according to `width`/`align`
@@ -718,7 +728,7 @@ impl<'tcx> FormatSpec<'tcx> {
         Some(Self {
             fill: spec.fill,
             align: spec.align,
-            flags: spec.flags,
+            no_flags: spec.sign.is_none() && !spec.alternate && !spec.zero_pad && spec.debug_hex.is_none(),
             precision: Count::new(
                 FormatParamUsage::Precision,
                 spec.precision,
@@ -763,7 +773,7 @@ impl<'tcx> FormatSpec<'tcx> {
         self.width.is_implied()
             && self.precision.is_implied()
             && self.align == Alignment::AlignUnknown
-            && self.flags == 0
+            && self.no_flags
     }
 }
 
@@ -890,7 +900,7 @@ impl<'tcx> FormatArgsExpn<'tcx> {
         // ::core::fmt::Arguments::new_v1_formatted(pieces, args, fmt, _unsafe_arg)
         if let ExprKind::Call(callee, [pieces, args, rest @ ..]) = expr.kind
             && let ExprKind::Path(QPath::TypeRelative(ty, seg)) = callee.kind
-            && is_path_diagnostic_item(cx, ty, sym::Arguments)
+            && let TyKind::Path(QPath::LangItem(LangItem::FormatArguments, _, _)) = ty.kind
             && matches!(seg.ident.as_str(), "new_v1" | "new_v1_formatted")
         {
             let format_string = FormatString::new(cx, pieces)?;
diff --git a/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs b/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
index 9adae773389..5836eb73bd9 100644
--- a/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
+++ b/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
@@ -140,7 +140,7 @@ impl TypeVisitor<'_> for ContainsRegion {
     type BreakTy = ();
 
     fn visit_region(&mut self, _: ty::Region<'_>) -> ControlFlow<Self::BreakTy> {
-        ControlFlow::BREAK
+        ControlFlow::Break(())
     }
 }
 
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index e5d7da68281..72705878075 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -55,7 +55,7 @@ pub fn is_min_const_fn<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, msrv: &Msrv)
     // impl trait is gone in MIR, so check the return type manually
     check_ty(
         tcx,
-        tcx.fn_sig(def_id).output().skip_binder(),
+        tcx.fn_sig(def_id).subst_identity().output().skip_binder(),
         body.local_decls.iter().next().unwrap().source_info.span,
     )?;
 
@@ -240,6 +240,7 @@ fn check_statement<'tcx>(
         | StatementKind::Retag { .. }
         | StatementKind::AscribeUserType(..)
         | StatementKind::Coverage(..)
+        | StatementKind::ConstEvalCounter
         | StatementKind::Nop => Ok(()),
     }
 }
diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs
index e7879bb196e..b8c87aa5e1e 100644
--- a/src/tools/clippy/clippy_utils/src/sugg.rs
+++ b/src/tools/clippy/clippy_utils/src/sugg.rs
@@ -219,6 +219,7 @@ impl<'a> Sugg<'a> {
             | ast::ExprKind::Repeat(..)
             | ast::ExprKind::Ret(..)
             | ast::ExprKind::Yeet(..)
+            | ast::ExprKind::FormatArgs(..)
             | ast::ExprKind::Struct(..)
             | ast::ExprKind::Try(..)
             | ast::ExprKind::TryBlock(..)
@@ -808,7 +809,7 @@ pub struct DerefClosure {
 ///
 /// note: this only works on single line immutable closures with exactly one input parameter.
 pub fn deref_closure_args(cx: &LateContext<'_>, closure: &hir::Expr<'_>) -> Option<DerefClosure> {
-    if let hir::ExprKind::Closure(&Closure { fn_decl, body, .. }) = closure.kind {
+    if let hir::ExprKind::Closure(&Closure { fn_decl, def_id, body, .. }) = closure.kind {
         let closure_body = cx.tcx.hir().body(body);
         // is closure arg a type annotated double reference (i.e.: `|x: &&i32| ...`)
         // a type annotation is present if param `kind` is different from `TyKind::Infer`
@@ -828,10 +829,8 @@ pub fn deref_closure_args(cx: &LateContext<'_>, closure: &hir::Expr<'_>) -> Opti
             applicability: Applicability::MachineApplicable,
         };
 
-        let fn_def_id = cx.tcx.hir().local_def_id(closure.hir_id);
         let infcx = cx.tcx.infer_ctxt().build();
-        ExprUseVisitor::new(&mut visitor, &infcx, fn_def_id, cx.param_env, cx.typeck_results())
-            .consume_body(closure_body);
+        ExprUseVisitor::new(&mut visitor, &infcx, def_id, cx.param_env, cx.typeck_results()).consume_body(closure_body);
 
         if !visitor.suggestion_start.is_empty() {
             return Some(DerefClosure {
@@ -884,7 +883,7 @@ impl<'tcx> DerefDelegate<'_, 'tcx> {
                     .cx
                     .typeck_results()
                     .type_dependent_def_id(parent_expr.hir_id)
-                    .map(|did| self.cx.tcx.fn_sig(did).skip_binder())
+                    .map(|did| self.cx.tcx.fn_sig(did).subst_identity().skip_binder())
                 {
                     std::iter::once(receiver)
                         .chain(call_args.iter())
diff --git a/src/tools/clippy/clippy_utils/src/ty.rs b/src/tools/clippy/clippy_utils/src/ty.rs
index 99fba4fe741..c48d27b05f0 100644
--- a/src/tools/clippy/clippy_utils/src/ty.rs
+++ b/src/tools/clippy/clippy_utils/src/ty.rs
@@ -628,7 +628,7 @@ impl<'tcx> ExprFnSig<'tcx> {
 /// If the expression is function like, get the signature for it.
 pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnSig<'tcx>> {
     if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
-        Some(ExprFnSig::Sig(cx.tcx.fn_sig(id), Some(id)))
+        Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).subst_identity(), Some(id)))
     } else {
         ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
     }
@@ -646,10 +646,13 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
                 .and_then(|id| cx.tcx.hir().fn_decl_by_hir_id(cx.tcx.hir().local_def_id_to_hir_id(id)));
             Some(ExprFnSig::Closure(decl, subs.as_closure().sig()))
         },
-        ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs), Some(id))),
-        ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => {
-            sig_from_bounds(cx, ty, cx.tcx.item_bounds(def_id).subst(cx.tcx, substs), cx.tcx.opt_parent(def_id))
-        },
+        ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).subst(cx.tcx, subs), Some(id))),
+        ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => sig_from_bounds(
+            cx,
+            ty,
+            cx.tcx.item_bounds(def_id).subst(cx.tcx, substs),
+            cx.tcx.opt_parent(def_id),
+        ),
         ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig, None)),
         ty::Dynamic(bounds, _, _) => {
             let lang_items = cx.tcx.lang_items();
diff --git a/src/tools/clippy/clippy_utils/src/visitors.rs b/src/tools/clippy/clippy_utils/src/visitors.rs
index 14c01a60b4c..d18b62d1bf1 100644
--- a/src/tools/clippy/clippy_utils/src/visitors.rs
+++ b/src/tools/clippy/clippy_utils/src/visitors.rs
@@ -392,12 +392,12 @@ pub fn is_expr_unsafe<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
                         .cx
                         .typeck_results()
                         .type_dependent_def_id(e.hir_id)
-                        .map_or(false, |id| self.cx.tcx.fn_sig(id).unsafety() == Unsafety::Unsafe) =>
+                        .map_or(false, |id| self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe) =>
                 {
                     self.is_unsafe = true;
                 },
                 ExprKind::Call(func, _) => match *self.cx.typeck_results().expr_ty(func).peel_refs().kind() {
-                    ty::FnDef(id, _) if self.cx.tcx.fn_sig(id).unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
+                    ty::FnDef(id, _) if self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
                     ty::FnPtr(sig) if sig.unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
                     _ => walk_expr(self, e),
                 },
diff --git a/src/tools/clippy/declare_clippy_lint/Cargo.toml b/src/tools/clippy/declare_clippy_lint/Cargo.toml
index c01e1062cb5..80eee368178 100644
--- a/src/tools/clippy/declare_clippy_lint/Cargo.toml
+++ b/src/tools/clippy/declare_clippy_lint/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "declare_clippy_lint"
-version = "0.1.68"
+version = "0.1.69"
 edition = "2021"
 publish = false
 
diff --git a/src/tools/clippy/rust-toolchain b/src/tools/clippy/rust-toolchain
index 40a6f47095e..4e7fc565a32 100644
--- a/src/tools/clippy/rust-toolchain
+++ b/src/tools/clippy/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2023-01-12"
+channel = "nightly-2023-01-27"
 components = ["cargo", "llvm-tools", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]
diff --git a/src/tools/clippy/src/main.rs b/src/tools/clippy/src/main.rs
index 7a78b32620d..82147eba33f 100644
--- a/src/tools/clippy/src/main.rs
+++ b/src/tools/clippy/src/main.rs
@@ -28,7 +28,7 @@ with:
     -D --deny OPT       Set lint denied
     -F --forbid OPT     Set lint forbidden
 
-You can use tool lints to allow or deny lints from your code, eg.:
+You can use tool lints to allow or deny lints from your code, e.g.:
 
     #[allow(clippy::needless_lifetimes)]
 "#;
diff --git a/src/tools/clippy/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr b/src/tools/clippy/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr
index 3ca45404e44..2a240cc249b 100644
--- a/src/tools/clippy/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr
+++ b/src/tools/clippy/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr
@@ -7,14 +7,6 @@ LL |     const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"];
    = help: convert all references to use `sym::Deref`
    = note: `-D clippy::unnecessary-def-path` implied by `-D warnings`
 
-error: hardcoded path to a language item
-  --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40
-   |
-LL |     const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"];
-   |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: convert all references to use `LangItem::DerefMut`
-
 error: hardcoded path to a diagnostic item
   --> $DIR/unnecessary_def_path_hardcoded_path.rs:12:43
    |
@@ -23,5 +15,13 @@ LL |     const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref",
    |
    = help: convert all references to use `sym::deref_method`
 
+error: hardcoded path to a language item
+  --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40
+   |
+LL |     const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"];
+   |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: convert all references to use `LangItem::DerefMut`
+
 error: aborting due to 3 previous errors
 
diff --git a/src/tools/clippy/tests/ui/bool_assert_comparison.fixed b/src/tools/clippy/tests/ui/bool_assert_comparison.fixed
new file mode 100644
index 00000000000..95f35a61bb2
--- /dev/null
+++ b/src/tools/clippy/tests/ui/bool_assert_comparison.fixed
@@ -0,0 +1,161 @@
+// run-rustfix
+
+#![allow(unused, clippy::assertions_on_constants)]
+#![warn(clippy::bool_assert_comparison)]
+
+use std::ops::Not;
+
+macro_rules! a {
+    () => {
+        true
+    };
+}
+macro_rules! b {
+    () => {
+        true
+    };
+}
+
+// Implements the Not trait but with an output type
+// that's not bool. Should not suggest a rewrite
+#[derive(Debug, Clone, Copy)]
+enum ImplNotTraitWithoutBool {
+    VariantX(bool),
+    VariantY(u32),
+}
+
+impl PartialEq<bool> for ImplNotTraitWithoutBool {
+    fn eq(&self, other: &bool) -> bool {
+        match *self {
+            ImplNotTraitWithoutBool::VariantX(b) => b == *other,
+            _ => false,
+        }
+    }
+}
+
+impl Not for ImplNotTraitWithoutBool {
+    type Output = Self;
+
+    fn not(self) -> Self::Output {
+        match self {
+            ImplNotTraitWithoutBool::VariantX(b) => ImplNotTraitWithoutBool::VariantX(!b),
+            ImplNotTraitWithoutBool::VariantY(0) => ImplNotTraitWithoutBool::VariantY(1),
+            ImplNotTraitWithoutBool::VariantY(_) => ImplNotTraitWithoutBool::VariantY(0),
+        }
+    }
+}
+
+// This type implements the Not trait with an Output of
+// type bool. Using assert!(..) must be suggested
+#[derive(Debug, Clone, Copy)]
+struct ImplNotTraitWithBool;
+
+impl PartialEq<bool> for ImplNotTraitWithBool {
+    fn eq(&self, other: &bool) -> bool {
+        false
+    }
+}
+
+impl Not for ImplNotTraitWithBool {
+    type Output = bool;
+
+    fn not(self) -> Self::Output {
+        true
+    }
+}
+
+#[derive(Debug)]
+struct NonCopy;
+
+impl PartialEq<bool> for NonCopy {
+    fn eq(&self, other: &bool) -> bool {
+        false
+    }
+}
+
+impl Not for NonCopy {
+    type Output = bool;
+
+    fn not(self) -> Self::Output {
+        true
+    }
+}
+
+fn main() {
+    let a = ImplNotTraitWithoutBool::VariantX(true);
+    let b = ImplNotTraitWithBool;
+
+    assert_eq!("a".len(), 1);
+    assert!("a".is_empty());
+    assert!("".is_empty());
+    assert!("".is_empty());
+    assert_eq!(a!(), b!());
+    assert_eq!(a!(), "".is_empty());
+    assert_eq!("".is_empty(), b!());
+    assert_eq!(a, true);
+    assert!(b);
+
+    assert_ne!("a".len(), 1);
+    assert!("a".is_empty());
+    assert!("".is_empty());
+    assert!("".is_empty());
+    assert_ne!(a!(), b!());
+    assert_ne!(a!(), "".is_empty());
+    assert_ne!("".is_empty(), b!());
+    assert_ne!(a, true);
+    assert!(b);
+
+    debug_assert_eq!("a".len(), 1);
+    debug_assert!("a".is_empty());
+    debug_assert!("".is_empty());
+    debug_assert!("".is_empty());
+    debug_assert_eq!(a!(), b!());
+    debug_assert_eq!(a!(), "".is_empty());
+    debug_assert_eq!("".is_empty(), b!());
+    debug_assert_eq!(a, true);
+    debug_assert!(b);
+
+    debug_assert_ne!("a".len(), 1);
+    debug_assert!("a".is_empty());
+    debug_assert!("".is_empty());
+    debug_assert!("".is_empty());
+    debug_assert_ne!(a!(), b!());
+    debug_assert_ne!(a!(), "".is_empty());
+    debug_assert_ne!("".is_empty(), b!());
+    debug_assert_ne!(a, true);
+    debug_assert!(b);
+
+    // assert with error messages
+    assert_eq!("a".len(), 1, "tadam {}", 1);
+    assert_eq!("a".len(), 1, "tadam {}", true);
+    assert!("a".is_empty(), "tadam {}", 1);
+    assert!("a".is_empty(), "tadam {}", true);
+    assert!("a".is_empty(), "tadam {}", true);
+    assert_eq!(a, true, "tadam {}", false);
+
+    debug_assert_eq!("a".len(), 1, "tadam {}", 1);
+    debug_assert_eq!("a".len(), 1, "tadam {}", true);
+    debug_assert!("a".is_empty(), "tadam {}", 1);
+    debug_assert!("a".is_empty(), "tadam {}", true);
+    debug_assert!("a".is_empty(), "tadam {}", true);
+    debug_assert_eq!(a, true, "tadam {}", false);
+
+    assert!(a!());
+    assert!(b!());
+
+    use debug_assert_eq as renamed;
+    renamed!(a, true);
+    debug_assert!(b);
+
+    let non_copy = NonCopy;
+    assert_eq!(non_copy, true);
+    // changing the above to `assert!(non_copy)` would cause a `borrow of moved value`
+    println!("{non_copy:?}");
+
+    macro_rules! in_macro {
+        ($v:expr) => {{
+            assert_eq!($v, true);
+        }};
+    }
+    in_macro!(a);
+}
diff --git a/src/tools/clippy/tests/ui/bool_assert_comparison.rs b/src/tools/clippy/tests/ui/bool_assert_comparison.rs
index ec4d6f3ff84..88e7560b4f9 100644
--- a/src/tools/clippy/tests/ui/bool_assert_comparison.rs
+++ b/src/tools/clippy/tests/ui/bool_assert_comparison.rs
@@ -1,3 +1,6 @@
+// run-rustfix
+
+#![allow(unused, clippy::assertions_on_constants)]
 #![warn(clippy::bool_assert_comparison)]
 
 use std::ops::Not;
@@ -15,7 +18,7 @@ macro_rules! b {
 
 // Implements the Not trait but with an output type
 // that's not bool. Should not suggest a rewrite
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 enum ImplNotTraitWithoutBool {
     VariantX(bool),
     VariantY(u32),
@@ -44,7 +47,7 @@ impl Not for ImplNotTraitWithoutBool {
 
 // This type implements the Not trait with an Output of
 // type bool. Using assert!(..) must be suggested
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 struct ImplNotTraitWithBool;
 
 impl PartialEq<bool> for ImplNotTraitWithBool {
@@ -61,6 +64,23 @@ impl Not for ImplNotTraitWithBool {
     }
 }
 
+#[derive(Debug)]
+struct NonCopy;
+
+impl PartialEq<bool> for NonCopy {
+    fn eq(&self, other: &bool) -> bool {
+        false
+    }
+}
+
+impl Not for NonCopy {
+    type Output = bool;
+
+    fn not(self) -> Self::Output {
+        true
+    }
+}
+
 fn main() {
     let a = ImplNotTraitWithoutBool::VariantX(true);
     let b = ImplNotTraitWithBool;
@@ -119,4 +139,23 @@ fn main() {
     debug_assert_eq!("a".is_empty(), false, "tadam {}", true);
     debug_assert_eq!(false, "a".is_empty(), "tadam {}", true);
     debug_assert_eq!(a, true, "tadam {}", false);
+
+    assert_eq!(a!(), true);
+    assert_eq!(true, b!());
+
+    use debug_assert_eq as renamed;
+    renamed!(a, true);
+    renamed!(b, true);
+
+    let non_copy = NonCopy;
+    assert_eq!(non_copy, true);
+    // changing the above to `assert!(non_copy)` would cause a `borrow of moved value`
+    println!("{non_copy:?}");
+
+    macro_rules! in_macro {
+        ($v:expr) => {{
+            assert_eq!($v, true);
+        }};
+    }
+    in_macro!(a);
 }
diff --git a/src/tools/clippy/tests/ui/bool_assert_comparison.stderr b/src/tools/clippy/tests/ui/bool_assert_comparison.stderr
index 377d51be4cd..3d9f8573e61 100644
--- a/src/tools/clippy/tests/ui/bool_assert_comparison.stderr
+++ b/src/tools/clippy/tests/ui/bool_assert_comparison.stderr
@@ -1,136 +1,303 @@
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:69:5
+  --> $DIR/bool_assert_comparison.rs:89:5
    |
 LL |     assert_eq!("a".is_empty(), false);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::bool-assert-comparison` implied by `-D warnings`
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!("a".is_empty(), false);
+LL +     assert!("a".is_empty());
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:70:5
+  --> $DIR/bool_assert_comparison.rs:90:5
    |
 LL |     assert_eq!("".is_empty(), true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!("".is_empty(), true);
+LL +     assert!("".is_empty());
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:71:5
+  --> $DIR/bool_assert_comparison.rs:91:5
    |
 LL |     assert_eq!(true, "".is_empty());
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!(true, "".is_empty());
+LL +     assert!("".is_empty());
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:76:5
+  --> $DIR/bool_assert_comparison.rs:96:5
    |
 LL |     assert_eq!(b, true);
-   |     ^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!(b, true);
+LL +     assert!(b);
+   |
 
 error: used `assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:79:5
+  --> $DIR/bool_assert_comparison.rs:99:5
    |
 LL |     assert_ne!("a".is_empty(), false);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_ne!("a".is_empty(), false);
+LL +     assert!("a".is_empty());
+   |
 
 error: used `assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:80:5
+  --> $DIR/bool_assert_comparison.rs:100:5
    |
 LL |     assert_ne!("".is_empty(), true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_ne!("".is_empty(), true);
+LL +     assert!("".is_empty());
+   |
 
 error: used `assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:81:5
+  --> $DIR/bool_assert_comparison.rs:101:5
    |
 LL |     assert_ne!(true, "".is_empty());
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_ne!(true, "".is_empty());
+LL +     assert!("".is_empty());
+   |
 
 error: used `assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:86:5
+  --> $DIR/bool_assert_comparison.rs:106:5
    |
 LL |     assert_ne!(b, true);
-   |     ^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_ne!(b, true);
+LL +     assert!(b);
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:89:5
+  --> $DIR/bool_assert_comparison.rs:109:5
    |
 LL |     debug_assert_eq!("a".is_empty(), false);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!("a".is_empty(), false);
+LL +     debug_assert!("a".is_empty());
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:90:5
+  --> $DIR/bool_assert_comparison.rs:110:5
    |
 LL |     debug_assert_eq!("".is_empty(), true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!("".is_empty(), true);
+LL +     debug_assert!("".is_empty());
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:91:5
+  --> $DIR/bool_assert_comparison.rs:111:5
    |
 LL |     debug_assert_eq!(true, "".is_empty());
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!(true, "".is_empty());
+LL +     debug_assert!("".is_empty());
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:96:5
+  --> $DIR/bool_assert_comparison.rs:116:5
    |
 LL |     debug_assert_eq!(b, true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!(b, true);
+LL +     debug_assert!(b);
+   |
 
 error: used `debug_assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:99:5
+  --> $DIR/bool_assert_comparison.rs:119:5
    |
 LL |     debug_assert_ne!("a".is_empty(), false);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_ne!("a".is_empty(), false);
+LL +     debug_assert!("a".is_empty());
+   |
 
 error: used `debug_assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:100:5
+  --> $DIR/bool_assert_comparison.rs:120:5
    |
 LL |     debug_assert_ne!("".is_empty(), true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_ne!("".is_empty(), true);
+LL +     debug_assert!("".is_empty());
+   |
 
 error: used `debug_assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:101:5
+  --> $DIR/bool_assert_comparison.rs:121:5
    |
 LL |     debug_assert_ne!(true, "".is_empty());
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_ne!(true, "".is_empty());
+LL +     debug_assert!("".is_empty());
+   |
 
 error: used `debug_assert_ne!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:106:5
+  --> $DIR/bool_assert_comparison.rs:126:5
    |
 LL |     debug_assert_ne!(b, true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_ne!(b, true);
+LL +     debug_assert!(b);
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:111:5
+  --> $DIR/bool_assert_comparison.rs:131:5
    |
 LL |     assert_eq!("a".is_empty(), false, "tadam {}", 1);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!("a".is_empty(), false, "tadam {}", 1);
+LL +     assert!("a".is_empty(), "tadam {}", 1);
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:112:5
+  --> $DIR/bool_assert_comparison.rs:132:5
    |
 LL |     assert_eq!("a".is_empty(), false, "tadam {}", true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!("a".is_empty(), false, "tadam {}", true);
+LL +     assert!("a".is_empty(), "tadam {}", true);
+   |
 
 error: used `assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:113:5
+  --> $DIR/bool_assert_comparison.rs:133:5
    |
 LL |     assert_eq!(false, "a".is_empty(), "tadam {}", true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!(false, "a".is_empty(), "tadam {}", true);
+LL +     assert!("a".is_empty(), "tadam {}", true);
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:118:5
+  --> $DIR/bool_assert_comparison.rs:138:5
    |
 LL |     debug_assert_eq!("a".is_empty(), false, "tadam {}", 1);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!("a".is_empty(), false, "tadam {}", 1);
+LL +     debug_assert!("a".is_empty(), "tadam {}", 1);
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:119:5
+  --> $DIR/bool_assert_comparison.rs:139:5
    |
 LL |     debug_assert_eq!("a".is_empty(), false, "tadam {}", true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!("a".is_empty(), false, "tadam {}", true);
+LL +     debug_assert!("a".is_empty(), "tadam {}", true);
+   |
 
 error: used `debug_assert_eq!` with a literal bool
-  --> $DIR/bool_assert_comparison.rs:120:5
+  --> $DIR/bool_assert_comparison.rs:140:5
    |
 LL |     debug_assert_eq!(false, "a".is_empty(), "tadam {}", true);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `debug_assert!(..)`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     debug_assert_eq!(false, "a".is_empty(), "tadam {}", true);
+LL +     debug_assert!("a".is_empty(), "tadam {}", true);
+   |
+
+error: used `assert_eq!` with a literal bool
+  --> $DIR/bool_assert_comparison.rs:143:5
+   |
+LL |     assert_eq!(a!(), true);
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!(a!(), true);
+LL +     assert!(a!());
+   |
+
+error: used `assert_eq!` with a literal bool
+  --> $DIR/bool_assert_comparison.rs:144:5
+   |
+LL |     assert_eq!(true, b!());
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `assert!(..)`
+   |
+LL -     assert_eq!(true, b!());
+LL +     assert!(b!());
+   |
+
+error: used `debug_assert_eq!` with a literal bool
+  --> $DIR/bool_assert_comparison.rs:148:5
+   |
+LL |     renamed!(b, true);
+   |     ^^^^^^^^^^^^^^^^^
+   |
+help: replace it with `debug_assert!(..)`
+   |
+LL -     renamed!(b, true);
+LL +     debug_assert!(b);
+   |
 
-error: aborting due to 22 previous errors
+error: aborting due to 25 previous errors
 
diff --git a/src/tools/clippy/tests/ui/cast.rs b/src/tools/clippy/tests/ui/cast.rs
index e6031e9adae..8b2673c2a7f 100644
--- a/src/tools/clippy/tests/ui/cast.rs
+++ b/src/tools/clippy/tests/ui/cast.rs
@@ -28,6 +28,7 @@ fn main() {
     1i32 as u8;
     1f64 as isize;
     1f64 as usize;
+    1f32 as u32 as u16;
     // Test clippy::cast_possible_wrap
     1u8 as i8;
     1u16 as i16;
diff --git a/src/tools/clippy/tests/ui/cast.stderr b/src/tools/clippy/tests/ui/cast.stderr
index 0c63b4af308..4af1de9aa38 100644
--- a/src/tools/clippy/tests/ui/cast.stderr
+++ b/src/tools/clippy/tests/ui/cast.stderr
@@ -42,13 +42,24 @@ error: casting `f32` to `i32` may truncate the value
 LL |     1f32 as i32;
    |     ^^^^^^^^^^^
    |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
    = note: `-D clippy::cast-possible-truncation` implied by `-D warnings`
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i32::try_from(1f32);
+   |     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `f32` to `u32` may truncate the value
   --> $DIR/cast.rs:25:5
    |
 LL |     1f32 as u32;
    |     ^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u32::try_from(1f32);
+   |     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `f32` to `u32` may lose the sign of the value
   --> $DIR/cast.rs:25:5
@@ -63,30 +74,60 @@ error: casting `f64` to `f32` may truncate the value
    |
 LL |     1f64 as f32;
    |     ^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     f32::try_from(1f64);
+   |     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `i32` to `i8` may truncate the value
   --> $DIR/cast.rs:27:5
    |
 LL |     1i32 as i8;
    |     ^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i8::try_from(1i32);
+   |     ~~~~~~~~~~~~~~~~~~
 
 error: casting `i32` to `u8` may truncate the value
   --> $DIR/cast.rs:28:5
    |
 LL |     1i32 as u8;
    |     ^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u8::try_from(1i32);
+   |     ~~~~~~~~~~~~~~~~~~
 
 error: casting `f64` to `isize` may truncate the value
   --> $DIR/cast.rs:29:5
    |
 LL |     1f64 as isize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     isize::try_from(1f64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `f64` to `usize` may truncate the value
   --> $DIR/cast.rs:30:5
    |
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     usize::try_from(1f64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `f64` to `usize` may lose the sign of the value
   --> $DIR/cast.rs:30:5
@@ -94,8 +135,38 @@ error: casting `f64` to `usize` may lose the sign of the value
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
 
+error: casting `u32` to `u16` may truncate the value
+  --> $DIR/cast.rs:31:5
+   |
+LL |     1f32 as u32 as u16;
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u16::try_from(1f32 as u32);
+   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: casting `f32` to `u32` may truncate the value
+  --> $DIR/cast.rs:31:5
+   |
+LL |     1f32 as u32 as u16;
+   |     ^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u32::try_from(1f32) as u16;
+   |     ~~~~~~~~~~~~~~~~~~~
+
+error: casting `f32` to `u32` may lose the sign of the value
+  --> $DIR/cast.rs:31:5
+   |
+LL |     1f32 as u32 as u16;
+   |     ^^^^^^^^^^^
+
 error: casting `u8` to `i8` may wrap around the value
-  --> $DIR/cast.rs:32:5
+  --> $DIR/cast.rs:33:5
    |
 LL |     1u8 as i8;
    |     ^^^^^^^^^
@@ -103,61 +174,79 @@ LL |     1u8 as i8;
    = note: `-D clippy::cast-possible-wrap` implied by `-D warnings`
 
 error: casting `u16` to `i16` may wrap around the value
-  --> $DIR/cast.rs:33:5
+  --> $DIR/cast.rs:34:5
    |
 LL |     1u16 as i16;
    |     ^^^^^^^^^^^
 
 error: casting `u32` to `i32` may wrap around the value
-  --> $DIR/cast.rs:34:5
+  --> $DIR/cast.rs:35:5
    |
 LL |     1u32 as i32;
    |     ^^^^^^^^^^^
 
 error: casting `u64` to `i64` may wrap around the value
-  --> $DIR/cast.rs:35:5
+  --> $DIR/cast.rs:36:5
    |
 LL |     1u64 as i64;
    |     ^^^^^^^^^^^
 
 error: casting `usize` to `isize` may wrap around the value
-  --> $DIR/cast.rs:36:5
+  --> $DIR/cast.rs:37:5
    |
 LL |     1usize as isize;
    |     ^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> $DIR/cast.rs:39:5
+  --> $DIR/cast.rs:40:5
    |
 LL |     -1i32 as u32;
    |     ^^^^^^^^^^^^
 
 error: casting `isize` to `usize` may lose the sign of the value
-  --> $DIR/cast.rs:41:5
+  --> $DIR/cast.rs:42:5
    |
 LL |     -1isize as usize;
    |     ^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `i8` may truncate the value
-  --> $DIR/cast.rs:108:5
+  --> $DIR/cast.rs:109:5
    |
 LL |     (-99999999999i64).min(1) as i8; // should be linted because signed
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i8::try_from((-99999999999i64).min(1)); // should be linted because signed
+   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u64` to `u8` may truncate the value
-  --> $DIR/cast.rs:120:5
+  --> $DIR/cast.rs:121:5
    |
 LL |     999999u64.clamp(0, 256) as u8; // should still be linted
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u8::try_from(999999u64.clamp(0, 256)); // should still be linted
+   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E2` to `u8` may truncate the value
-  --> $DIR/cast.rs:141:21
+  --> $DIR/cast.rs:142:21
    |
 LL |             let _ = self as u8;
    |                     ^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |             let _ = u8::try_from(self);
+   |                     ~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E2::B` to `u8` will truncate the value
-  --> $DIR/cast.rs:142:21
+  --> $DIR/cast.rs:143:21
    |
 LL |             let _ = Self::B as u8;
    |                     ^^^^^^^^^^^^^
@@ -165,46 +254,82 @@ LL |             let _ = Self::B as u8;
    = note: `-D clippy::cast-enum-truncation` implied by `-D warnings`
 
 error: casting `main::E5` to `i8` may truncate the value
-  --> $DIR/cast.rs:178:21
+  --> $DIR/cast.rs:179:21
    |
 LL |             let _ = self as i8;
    |                     ^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |             let _ = i8::try_from(self);
+   |                     ~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E5::A` to `i8` will truncate the value
-  --> $DIR/cast.rs:179:21
+  --> $DIR/cast.rs:180:21
    |
 LL |             let _ = Self::A as i8;
    |                     ^^^^^^^^^^^^^
 
 error: casting `main::E6` to `i16` may truncate the value
-  --> $DIR/cast.rs:193:21
+  --> $DIR/cast.rs:194:21
    |
 LL |             let _ = self as i16;
    |                     ^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |             let _ = i16::try_from(self);
+   |                     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E7` to `usize` may truncate the value on targets with 32-bit wide pointers
-  --> $DIR/cast.rs:208:21
+  --> $DIR/cast.rs:209:21
    |
 LL |             let _ = self as usize;
    |                     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |             let _ = usize::try_from(self);
+   |                     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E10` to `u16` may truncate the value
-  --> $DIR/cast.rs:249:21
+  --> $DIR/cast.rs:250:21
    |
 LL |             let _ = self as u16;
    |                     ^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |             let _ = u16::try_from(self);
+   |                     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `u32` to `u8` may truncate the value
-  --> $DIR/cast.rs:257:13
+  --> $DIR/cast.rs:258:13
    |
 LL |     let c = (q >> 16) as u8;
    |             ^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     let c = u8::try_from((q >> 16));
+   |             ~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u32` to `u8` may truncate the value
-  --> $DIR/cast.rs:260:13
+  --> $DIR/cast.rs:261:13
    |
 LL |     let c = (q / 1000) as u8;
    |             ^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     let c = u8::try_from((q / 1000));
+   |             ~~~~~~~~~~~~~~~~~~~~~~~~
 
-error: aborting due to 33 previous errors
+error: aborting due to 36 previous errors
 
diff --git a/src/tools/clippy/tests/ui/cast_size.stderr b/src/tools/clippy/tests/ui/cast_size.stderr
index 95552f2e285..8acf26049f4 100644
--- a/src/tools/clippy/tests/ui/cast_size.stderr
+++ b/src/tools/clippy/tests/ui/cast_size.stderr
@@ -4,7 +4,12 @@ error: casting `isize` to `i8` may truncate the value
 LL |     1isize as i8;
    |     ^^^^^^^^^^^^
    |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
    = note: `-D clippy::cast-possible-truncation` implied by `-D warnings`
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i8::try_from(1isize);
+   |     ~~~~~~~~~~~~~~~~~~~~
 
 error: casting `isize` to `f64` causes a loss of precision on targets with 64-bit wide pointers (`isize` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide)
   --> $DIR/cast_size.rs:15:5
@@ -37,24 +42,48 @@ error: casting `isize` to `i32` may truncate the value on targets with 64-bit wi
    |
 LL |     1isize as i32;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i32::try_from(1isize);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `isize` to `u32` may truncate the value on targets with 64-bit wide pointers
   --> $DIR/cast_size.rs:20:5
    |
 LL |     1isize as u32;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u32::try_from(1isize);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `u32` may truncate the value on targets with 64-bit wide pointers
   --> $DIR/cast_size.rs:21:5
    |
 LL |     1usize as u32;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u32::try_from(1usize);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `i32` may truncate the value on targets with 64-bit wide pointers
   --> $DIR/cast_size.rs:22:5
    |
 LL |     1usize as i32;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     i32::try_from(1usize);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `i32` may wrap around the value on targets with 32-bit wide pointers
   --> $DIR/cast_size.rs:22:5
@@ -69,18 +98,36 @@ error: casting `i64` to `isize` may truncate the value on targets with 32-bit wi
    |
 LL |     1i64 as isize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     isize::try_from(1i64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `i64` to `usize` may truncate the value on targets with 32-bit wide pointers
   --> $DIR/cast_size.rs:25:5
    |
 LL |     1i64 as usize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     usize::try_from(1i64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u64` to `isize` may truncate the value on targets with 32-bit wide pointers
   --> $DIR/cast_size.rs:26:5
    |
 LL |     1u64 as isize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     isize::try_from(1u64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u64` to `isize` may wrap around the value on targets with 64-bit wide pointers
   --> $DIR/cast_size.rs:26:5
@@ -93,6 +140,12 @@ error: casting `u64` to `usize` may truncate the value on targets with 32-bit wi
    |
 LL |     1u64 as usize;
    |     ^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     usize::try_from(1u64);
+   |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u32` to `isize` may wrap around the value on targets with 32-bit wide pointers
   --> $DIR/cast_size.rs:28:5
diff --git a/src/tools/clippy/tests/ui/module_name_repetitions.stderr b/src/tools/clippy/tests/ui/module_name_repetitions.stderr
index 3f343a3e430..277801194a1 100644
--- a/src/tools/clippy/tests/ui/module_name_repetitions.stderr
+++ b/src/tools/clippy/tests/ui/module_name_repetitions.stderr
@@ -1,34 +1,34 @@
 error: item name starts with its containing module's name
-  --> $DIR/module_name_repetitions.rs:8:5
+  --> $DIR/module_name_repetitions.rs:8:12
    |
 LL |     pub fn foo_bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^
+   |            ^^^^^^^
    |
    = note: `-D clippy::module-name-repetitions` implied by `-D warnings`
 
 error: item name ends with its containing module's name
-  --> $DIR/module_name_repetitions.rs:9:5
+  --> $DIR/module_name_repetitions.rs:9:12
    |
 LL |     pub fn bar_foo() {}
-   |     ^^^^^^^^^^^^^^^^^^^
+   |            ^^^^^^^
 
 error: item name starts with its containing module's name
-  --> $DIR/module_name_repetitions.rs:10:5
+  --> $DIR/module_name_repetitions.rs:10:16
    |
 LL |     pub struct FooCake;
-   |     ^^^^^^^^^^^^^^^^^^^
+   |                ^^^^^^^
 
 error: item name ends with its containing module's name
-  --> $DIR/module_name_repetitions.rs:11:5
+  --> $DIR/module_name_repetitions.rs:11:14
    |
 LL |     pub enum CakeFoo {}
-   |     ^^^^^^^^^^^^^^^^^^^
+   |              ^^^^^^^
 
 error: item name starts with its containing module's name
-  --> $DIR/module_name_repetitions.rs:12:5
+  --> $DIR/module_name_repetitions.rs:12:16
    |
 LL |     pub struct Foo7Bar;
-   |     ^^^^^^^^^^^^^^^^^^^
+   |                ^^^^^^^
 
 error: aborting due to 5 previous errors
 
diff --git a/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.rs b/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.rs
new file mode 100644
index 00000000000..41263535df6
--- /dev/null
+++ b/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.rs
@@ -0,0 +1,110 @@
+#![allow(unused)]
+#![allow(deref_nullptr)]
+#![allow(clippy::unnecessary_operation)]
+#![allow(clippy::drop_copy)]
+#![warn(clippy::multiple_unsafe_ops_per_block)]
+
+use core::arch::asm;
+
+fn raw_ptr() -> *const () {
+    core::ptr::null()
+}
+
+unsafe fn not_very_safe() {}
+
+struct Sample;
+
+impl Sample {
+    unsafe fn not_very_safe(&self) {}
+}
+
+#[allow(non_upper_case_globals)]
+const sample: Sample = Sample;
+
+union U {
+    i: i32,
+    u: u32,
+}
+
+static mut STATIC: i32 = 0;
+
+fn test1() {
+    unsafe {
+        STATIC += 1;
+        not_very_safe();
+    }
+}
+
+fn test2() {
+    let u = U { i: 0 };
+
+    unsafe {
+        drop(u.u);
+        *raw_ptr();
+    }
+}
+
+fn test3() {
+    unsafe {
+        asm!("nop");
+        sample.not_very_safe();
+        STATIC = 0;
+    }
+}
+
+fn test_all() {
+    let u = U { i: 0 };
+    unsafe {
+        drop(u.u);
+        drop(STATIC);
+        sample.not_very_safe();
+        not_very_safe();
+        *raw_ptr();
+        asm!("nop");
+    }
+}
+
+// no lint
+fn correct1() {
+    unsafe {
+        STATIC += 1;
+    }
+}
+
+// no lint
+fn correct2() {
+    unsafe {
+        STATIC += 1;
+    }
+
+    unsafe {
+        *raw_ptr();
+    }
+}
+
+// no lint
+fn correct3() {
+    let u = U { u: 0 };
+
+    unsafe {
+        not_very_safe();
+    }
+
+    unsafe {
+        drop(u.i);
+    }
+}
+
+// tests from the issue (https://github.com/rust-lang/rust-clippy/issues/10064)
+
+unsafe fn read_char_bad(ptr: *const u8) -> char {
+    unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
+}
+
+// no lint
+unsafe fn read_char_good(ptr: *const u8) -> char {
+    let int_value = unsafe { *ptr.cast::<u32>() };
+    unsafe { core::char::from_u32_unchecked(int_value) }
+}
+
+fn main() {}
diff --git a/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.stderr b/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.stderr
new file mode 100644
index 00000000000..f6b8341795d
--- /dev/null
+++ b/src/tools/clippy/tests/ui/multiple_unsafe_ops_per_block.stderr
@@ -0,0 +1,129 @@
+error: this `unsafe` block contains 2 unsafe operations, expected only one
+  --> $DIR/multiple_unsafe_ops_per_block.rs:32:5
+   |
+LL | /     unsafe {
+LL | |         STATIC += 1;
+LL | |         not_very_safe();
+LL | |     }
+   | |_____^
+   |
+note: modification of a mutable static occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:33:9
+   |
+LL |         STATIC += 1;
+   |         ^^^^^^^^^^^
+note: unsafe function call occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:34:9
+   |
+LL |         not_very_safe();
+   |         ^^^^^^^^^^^^^^^
+   = note: `-D clippy::multiple-unsafe-ops-per-block` implied by `-D warnings`
+
+error: this `unsafe` block contains 2 unsafe operations, expected only one
+  --> $DIR/multiple_unsafe_ops_per_block.rs:41:5
+   |
+LL | /     unsafe {
+LL | |         drop(u.u);
+LL | |         *raw_ptr();
+LL | |     }
+   | |_____^
+   |
+note: union field access occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:42:14
+   |
+LL |         drop(u.u);
+   |              ^^^
+note: raw pointer dereference occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:43:9
+   |
+LL |         *raw_ptr();
+   |         ^^^^^^^^^^
+
+error: this `unsafe` block contains 3 unsafe operations, expected only one
+  --> $DIR/multiple_unsafe_ops_per_block.rs:48:5
+   |
+LL | /     unsafe {
+LL | |         asm!("nop");
+LL | |         sample.not_very_safe();
+LL | |         STATIC = 0;
+LL | |     }
+   | |_____^
+   |
+note: inline assembly used here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:49:9
+   |
+LL |         asm!("nop");
+   |         ^^^^^^^^^^^
+note: unsafe method call occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:50:9
+   |
+LL |         sample.not_very_safe();
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+note: modification of a mutable static occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:51:9
+   |
+LL |         STATIC = 0;
+   |         ^^^^^^^^^^
+
+error: this `unsafe` block contains 6 unsafe operations, expected only one
+  --> $DIR/multiple_unsafe_ops_per_block.rs:57:5
+   |
+LL | /     unsafe {
+LL | |         drop(u.u);
+LL | |         drop(STATIC);
+LL | |         sample.not_very_safe();
+...  |
+LL | |         asm!("nop");
+LL | |     }
+   | |_____^
+   |
+note: union field access occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:58:14
+   |
+LL |         drop(u.u);
+   |              ^^^
+note: access of a mutable static occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:59:14
+   |
+LL |         drop(STATIC);
+   |              ^^^^^^
+note: unsafe method call occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:60:9
+   |
+LL |         sample.not_very_safe();
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+note: unsafe function call occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:61:9
+   |
+LL |         not_very_safe();
+   |         ^^^^^^^^^^^^^^^
+note: raw pointer dereference occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:62:9
+   |
+LL |         *raw_ptr();
+   |         ^^^^^^^^^^
+note: inline assembly used here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:63:9
+   |
+LL |         asm!("nop");
+   |         ^^^^^^^^^^^
+
+error: this `unsafe` block contains 2 unsafe operations, expected only one
+  --> $DIR/multiple_unsafe_ops_per_block.rs:101:5
+   |
+LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: unsafe function call occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:101:14
+   |
+LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: raw pointer dereference occurs here
+  --> $DIR/multiple_unsafe_ops_per_block.rs:101:39
+   |
+LL |     unsafe { char::from_u32_unchecked(*ptr.cast::<u32>()) }
+   |                                       ^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
+
diff --git a/src/tools/clippy/tests/ui/needless_return.fixed b/src/tools/clippy/tests/ui/needless_return.fixed
index ab1c0e590bb..079e3531def 100644
--- a/src/tools/clippy/tests/ui/needless_return.fixed
+++ b/src/tools/clippy/tests/ui/needless_return.fixed
@@ -31,6 +31,16 @@ fn test_no_semicolon() -> bool {
     true
 }
 
+#[rustfmt::skip]
+fn test_multiple_semicolon() -> bool {
+    true
+}
+
+#[rustfmt::skip]
+fn test_multiple_semicolon_with_spaces() -> bool {
+    true
+}
+
 fn test_if_block() -> bool {
     if true {
         true
diff --git a/src/tools/clippy/tests/ui/needless_return.rs b/src/tools/clippy/tests/ui/needless_return.rs
index abed338bb9b..c1c48284f08 100644
--- a/src/tools/clippy/tests/ui/needless_return.rs
+++ b/src/tools/clippy/tests/ui/needless_return.rs
@@ -31,6 +31,16 @@ fn test_no_semicolon() -> bool {
     return true;
 }
 
+#[rustfmt::skip]
+fn test_multiple_semicolon() -> bool {
+    return true;;;
+}
+
+#[rustfmt::skip]
+fn test_multiple_semicolon_with_spaces() -> bool {
+    return true;; ; ;
+}
+
 fn test_if_block() -> bool {
     if true {
         return true;
diff --git a/src/tools/clippy/tests/ui/needless_return.stderr b/src/tools/clippy/tests/ui/needless_return.stderr
index 52eabf6e137..08b04bfe9d8 100644
--- a/src/tools/clippy/tests/ui/needless_return.stderr
+++ b/src/tools/clippy/tests/ui/needless_return.stderr
@@ -16,7 +16,23 @@ LL |     return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:36:9
+  --> $DIR/needless_return.rs:36:5
+   |
+LL |     return true;;;
+   |     ^^^^^^^^^^^
+   |
+   = help: remove `return`
+
+error: unneeded `return` statement
+  --> $DIR/needless_return.rs:41:5
+   |
+LL |     return true;; ; ;
+   |     ^^^^^^^^^^^
+   |
+   = help: remove `return`
+
+error: unneeded `return` statement
+  --> $DIR/needless_return.rs:46:9
    |
 LL |         return true;
    |         ^^^^^^^^^^^
@@ -24,7 +40,7 @@ LL |         return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:38:9
+  --> $DIR/needless_return.rs:48:9
    |
 LL |         return false;
    |         ^^^^^^^^^^^^
@@ -32,7 +48,7 @@ LL |         return false;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:44:17
+  --> $DIR/needless_return.rs:54:17
    |
 LL |         true => return false,
    |                 ^^^^^^^^^^^^
@@ -40,7 +56,7 @@ LL |         true => return false,
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:46:13
+  --> $DIR/needless_return.rs:56:13
    |
 LL |             return true;
    |             ^^^^^^^^^^^
@@ -48,7 +64,7 @@ LL |             return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:53:9
+  --> $DIR/needless_return.rs:63:9
    |
 LL |         return true;
    |         ^^^^^^^^^^^
@@ -56,7 +72,7 @@ LL |         return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:55:16
+  --> $DIR/needless_return.rs:65:16
    |
 LL |     let _ = || return true;
    |                ^^^^^^^^^^^
@@ -64,7 +80,7 @@ LL |     let _ = || return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:59:5
+  --> $DIR/needless_return.rs:69:5
    |
 LL |     return the_answer!();
    |     ^^^^^^^^^^^^^^^^^^^^
@@ -72,7 +88,7 @@ LL |     return the_answer!();
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:62:21
+  --> $DIR/needless_return.rs:72:21
    |
 LL |   fn test_void_fun() {
    |  _____________________^
@@ -82,7 +98,7 @@ LL | |     return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:67:11
+  --> $DIR/needless_return.rs:77:11
    |
 LL |       if b {
    |  ___________^
@@ -92,7 +108,7 @@ LL | |         return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:69:13
+  --> $DIR/needless_return.rs:79:13
    |
 LL |       } else {
    |  _____________^
@@ -102,7 +118,7 @@ LL | |         return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:77:14
+  --> $DIR/needless_return.rs:87:14
    |
 LL |         _ => return,
    |              ^^^^^^
@@ -110,7 +126,7 @@ LL |         _ => return,
    = help: replace `return` with a unit value
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:85:24
+  --> $DIR/needless_return.rs:95:24
    |
 LL |               let _ = 42;
    |  ________________________^
@@ -120,7 +136,7 @@ LL | |             return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:88:14
+  --> $DIR/needless_return.rs:98:14
    |
 LL |         _ => return,
    |              ^^^^^^
@@ -128,7 +144,7 @@ LL |         _ => return,
    = help: replace `return` with a unit value
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:101:9
+  --> $DIR/needless_return.rs:111:9
    |
 LL |         return String::from("test");
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -136,7 +152,7 @@ LL |         return String::from("test");
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:103:9
+  --> $DIR/needless_return.rs:113:9
    |
 LL |         return String::new();
    |         ^^^^^^^^^^^^^^^^^^^^
@@ -144,7 +160,7 @@ LL |         return String::new();
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:125:32
+  --> $DIR/needless_return.rs:135:32
    |
 LL |         bar.unwrap_or_else(|_| return)
    |                                ^^^^^^
@@ -152,7 +168,7 @@ LL |         bar.unwrap_or_else(|_| return)
    = help: replace `return` with an empty block
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:129:21
+  --> $DIR/needless_return.rs:139:21
    |
 LL |           let _ = || {
    |  _____________________^
@@ -162,7 +178,7 @@ LL | |             return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:132:20
+  --> $DIR/needless_return.rs:142:20
    |
 LL |         let _ = || return;
    |                    ^^^^^^
@@ -170,7 +186,7 @@ LL |         let _ = || return;
    = help: replace `return` with an empty block
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:138:32
+  --> $DIR/needless_return.rs:148:32
    |
 LL |         res.unwrap_or_else(|_| return Foo)
    |                                ^^^^^^^^^^
@@ -178,7 +194,7 @@ LL |         res.unwrap_or_else(|_| return Foo)
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:147:5
+  --> $DIR/needless_return.rs:157:5
    |
 LL |     return true;
    |     ^^^^^^^^^^^
@@ -186,7 +202,7 @@ LL |     return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:151:5
+  --> $DIR/needless_return.rs:161:5
    |
 LL |     return true;
    |     ^^^^^^^^^^^
@@ -194,7 +210,7 @@ LL |     return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:156:9
+  --> $DIR/needless_return.rs:166:9
    |
 LL |         return true;
    |         ^^^^^^^^^^^
@@ -202,7 +218,7 @@ LL |         return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:158:9
+  --> $DIR/needless_return.rs:168:9
    |
 LL |         return false;
    |         ^^^^^^^^^^^^
@@ -210,7 +226,7 @@ LL |         return false;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:164:17
+  --> $DIR/needless_return.rs:174:17
    |
 LL |         true => return false,
    |                 ^^^^^^^^^^^^
@@ -218,7 +234,7 @@ LL |         true => return false,
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:166:13
+  --> $DIR/needless_return.rs:176:13
    |
 LL |             return true;
    |             ^^^^^^^^^^^
@@ -226,7 +242,7 @@ LL |             return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:173:9
+  --> $DIR/needless_return.rs:183:9
    |
 LL |         return true;
    |         ^^^^^^^^^^^
@@ -234,7 +250,7 @@ LL |         return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:175:16
+  --> $DIR/needless_return.rs:185:16
    |
 LL |     let _ = || return true;
    |                ^^^^^^^^^^^
@@ -242,7 +258,7 @@ LL |     let _ = || return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:179:5
+  --> $DIR/needless_return.rs:189:5
    |
 LL |     return the_answer!();
    |     ^^^^^^^^^^^^^^^^^^^^
@@ -250,7 +266,7 @@ LL |     return the_answer!();
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:182:33
+  --> $DIR/needless_return.rs:192:33
    |
 LL |   async fn async_test_void_fun() {
    |  _________________________________^
@@ -260,7 +276,7 @@ LL | |     return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:187:11
+  --> $DIR/needless_return.rs:197:11
    |
 LL |       if b {
    |  ___________^
@@ -270,7 +286,7 @@ LL | |         return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:189:13
+  --> $DIR/needless_return.rs:199:13
    |
 LL |       } else {
    |  _____________^
@@ -280,7 +296,7 @@ LL | |         return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:197:14
+  --> $DIR/needless_return.rs:207:14
    |
 LL |         _ => return,
    |              ^^^^^^
@@ -288,7 +304,7 @@ LL |         _ => return,
    = help: replace `return` with a unit value
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:210:9
+  --> $DIR/needless_return.rs:220:9
    |
 LL |         return String::from("test");
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -296,7 +312,7 @@ LL |         return String::from("test");
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:212:9
+  --> $DIR/needless_return.rs:222:9
    |
 LL |         return String::new();
    |         ^^^^^^^^^^^^^^^^^^^^
@@ -304,7 +320,7 @@ LL |         return String::new();
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:228:5
+  --> $DIR/needless_return.rs:238:5
    |
 LL |     return format!("Hello {}", "world!");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -312,7 +328,7 @@ LL |     return format!("Hello {}", "world!");
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:239:9
+  --> $DIR/needless_return.rs:249:9
    |
 LL |         return true;
    |         ^^^^^^^^^^^
@@ -320,7 +336,7 @@ LL |         return true;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:241:9
+  --> $DIR/needless_return.rs:251:9
    |
 LL |         return false;
    |         ^^^^^^^^^^^^
@@ -328,7 +344,7 @@ LL |         return false;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:248:13
+  --> $DIR/needless_return.rs:258:13
    |
 LL |             return 10;
    |             ^^^^^^^^^
@@ -336,7 +352,7 @@ LL |             return 10;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:251:13
+  --> $DIR/needless_return.rs:261:13
    |
 LL |             return 100;
    |             ^^^^^^^^^^
@@ -344,7 +360,7 @@ LL |             return 100;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:259:9
+  --> $DIR/needless_return.rs:269:9
    |
 LL |         return 0;
    |         ^^^^^^^^
@@ -352,7 +368,7 @@ LL |         return 0;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:266:13
+  --> $DIR/needless_return.rs:276:13
    |
 LL |             return *(x as *const isize);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -360,7 +376,7 @@ LL |             return *(x as *const isize);
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:268:13
+  --> $DIR/needless_return.rs:278:13
    |
 LL |             return !*(x as *const isize);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -368,7 +384,7 @@ LL |             return !*(x as *const isize);
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:275:20
+  --> $DIR/needless_return.rs:285:20
    |
 LL |           let _ = 42;
    |  ____________________^
@@ -379,7 +395,7 @@ LL | |         return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:282:20
+  --> $DIR/needless_return.rs:292:20
    |
 LL |         let _ = 42; return;
    |                    ^^^^^^^
@@ -387,7 +403,7 @@ LL |         let _ = 42; return;
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:294:9
+  --> $DIR/needless_return.rs:304:9
    |
 LL |         return Ok(format!("ok!"));
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -395,12 +411,12 @@ LL |         return Ok(format!("ok!"));
    = help: remove `return`
 
 error: unneeded `return` statement
-  --> $DIR/needless_return.rs:296:9
+  --> $DIR/needless_return.rs:306:9
    |
 LL |         return Err(format!("err!"));
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: remove `return`
 
-error: aborting due to 48 previous errors
+error: aborting due to 50 previous errors
 
diff --git a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.fixed b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.fixed
index 7263abac15d..55307506eb3 100644
--- a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.fixed
+++ b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.fixed
@@ -51,6 +51,8 @@ fn main() {
     // e is a function pointer type and U is an integer; fptr-addr-cast
     let _usize_from_fn_ptr_transmute = unsafe { foo as usize };
     let _usize_from_fn_ptr = foo as *const usize;
+
+    let _usize_from_ref = unsafe { &1u32 as *const u32 as usize };
 }
 
 // If a ref-to-ptr cast of this form where the pointer type points to a type other
diff --git a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.rs b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.rs
index d8e4421d4c1..e7360f3f9dc 100644
--- a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.rs
+++ b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.rs
@@ -51,6 +51,8 @@ fn main() {
     // e is a function pointer type and U is an integer; fptr-addr-cast
     let _usize_from_fn_ptr_transmute = unsafe { transmute::<fn(usize) -> u8, usize>(foo) };
     let _usize_from_fn_ptr = foo as *const usize;
+
+    let _usize_from_ref = unsafe { transmute::<*const u32, usize>(&1u32) };
 }
 
 // If a ref-to-ptr cast of this form where the pointer type points to a type other
diff --git a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.stderr b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.stderr
index de9418c8d1a..e862fcb67a4 100644
--- a/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.stderr
+++ b/src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.stderr
@@ -46,11 +46,17 @@ error: transmute from `fn(usize) -> u8` to `usize` which could be expressed as a
 LL |     let _usize_from_fn_ptr_transmute = unsafe { transmute::<fn(usize) -> u8, usize>(foo) };
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `foo as usize`
 
+error: transmute from `*const u32` to `usize` which could be expressed as a pointer cast instead
+  --> $DIR/transmutes_expressible_as_ptr_casts.rs:55:36
+   |
+LL |     let _usize_from_ref = unsafe { transmute::<*const u32, usize>(&1u32) };
+   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&1u32 as *const u32 as usize`
+
 error: transmute from a reference to a pointer
-  --> $DIR/transmutes_expressible_as_ptr_casts.rs:64:14
+  --> $DIR/transmutes_expressible_as_ptr_casts.rs:66:14
    |
 LL |     unsafe { transmute::<&[i32; 1], *const u8>(in_param) }
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `in_param as *const [i32; 1] as *const u8`
 
-error: aborting due to 8 previous errors
+error: aborting due to 9 previous errors
 
diff --git a/src/tools/clippy/tests/ui/unnecessary_safety_comment.rs b/src/tools/clippy/tests/ui/unnecessary_safety_comment.rs
index 7fefea7051d..89fedb145f8 100644
--- a/src/tools/clippy/tests/ui/unnecessary_safety_comment.rs
+++ b/src/tools/clippy/tests/ui/unnecessary_safety_comment.rs
@@ -48,4 +48,21 @@ fn unnecessary_on_stmt_and_expr() -> u32 {
     24
 }
 
+mod issue_10084 {
+    unsafe fn bar() -> i32 {
+        42
+    }
+
+    macro_rules! foo {
+        () => {
+            // SAFETY: This is necessary
+            unsafe { bar() }
+        };
+    }
+
+    fn main() {
+        foo!();
+    }
+}
+
 fn main() {}
diff --git a/src/tools/miri/ci.sh b/src/tools/miri/ci.sh
index e01bfbc74d9..db9f180a5e5 100755
--- a/src/tools/miri/ci.sh
+++ b/src/tools/miri/ci.sh
@@ -43,7 +43,8 @@ function run_tests {
     # optimizations up all the way, too).
     # Optimizations change diagnostics (mostly backtraces), so we don't check
     # them. Also error locations change so we don't run the failing tests.
-    MIRIFLAGS="${MIRIFLAGS:-} -O -Zmir-opt-level=4" MIRI_SKIP_UI_CHECKS=1 ./miri test -- tests/{pass,panic}
+    #FIXME: temporarily disabled due to <https://github.com/rust-lang/rust/issues/107511>.
+    #MIRIFLAGS="${MIRIFLAGS:-} -O -Zmir-opt-level=4" MIRI_SKIP_UI_CHECKS=1 ./miri test -- tests/{pass,panic}
 
     # Also run some many-seeds tests. 64 seeds means this takes around a minute per test.
     for FILE in tests/many-seeds/*.rs; do
diff --git a/src/tools/miri/rust-version b/src/tools/miri/rust-version
index 0f7f4851c7a..f1f26e4e310 100644
--- a/src/tools/miri/rust-version
+++ b/src/tools/miri/rust-version
@@ -1 +1 @@
-ad48c109815a2e9441a7ad7796e55b8771fe01a5
+a322848c6b0e037c1f0209387558ecb6ab763714
diff --git a/src/tools/miri/src/eval.rs b/src/tools/miri/src/eval.rs
index 6c87dad1f1f..96ab8b0d98e 100644
--- a/src/tools/miri/src/eval.rs
+++ b/src/tools/miri/src/eval.rs
@@ -357,7 +357,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
     match entry_type {
         EntryFnType::Main { .. } => {
             let start_id = tcx.lang_items().start_fn().unwrap();
-            let main_ret_ty = tcx.fn_sig(entry_id).output();
+            let main_ret_ty = tcx.fn_sig(entry_id).no_bound_vars().unwrap().output();
             let main_ret_ty = main_ret_ty.no_bound_vars().unwrap();
             let start_instance = ty::Instance::resolve(
                 tcx,
diff --git a/src/tools/publish_toolstate.py b/src/tools/publish_toolstate.py
index 9c16ef2cbec..395bcc745f8 100755
--- a/src/tools/publish_toolstate.py
+++ b/src/tools/publish_toolstate.py
@@ -68,52 +68,6 @@ def load_json_from_response(resp):
         print("Refusing to decode " + str(type(content)) + " to str")
     return json.loads(content_str)
 
-def validate_maintainers(repo, github_token):
-    # type: (str, str) -> None
-    '''Ensure all maintainers are assignable on a GitHub repo'''
-    next_link_re = re.compile(r'<([^>]+)>; rel="next"')
-
-    # Load the list of assignable people in the GitHub repo
-    assignable = [] # type: typing.List[str]
-    url = 'https://api.github.com/repos/' \
-        + '%s/collaborators?per_page=100' % repo # type: typing.Optional[str]
-    while url is not None:
-        response = urllib2.urlopen(urllib2.Request(url, headers={
-            'Authorization': 'token ' + github_token,
-            # Properly load nested teams.
-            'Accept': 'application/vnd.github.hellcat-preview+json',
-        }))
-        assignable.extend(user['login'] for user in load_json_from_response(response))
-        # Load the next page if available
-        url = None
-        link_header = response.headers.get('Link')
-        if link_header:
-            matches = next_link_re.match(link_header)
-            if matches is not None:
-                url = matches.group(1)
-
-    errors = False
-    for tool, maintainers in MAINTAINERS.items():
-        for maintainer in maintainers:
-            if maintainer not in assignable:
-                errors = True
-                print(
-                    "error: %s maintainer @%s is not assignable in the %s repo"
-                    % (tool, maintainer, repo),
-                )
-
-    if errors:
-        print()
-        print("  To be assignable, a person needs to be explicitly listed as a")
-        print("  collaborator in the repository settings. The simple way to")
-        print("  fix this is to ask someone with 'admin' privileges on the repo")
-        print("  to add the person or whole team as a collaborator with 'read'")
-        print("  privileges. Those privileges don't grant any extra permissions")
-        print("  so it's safe to apply them.")
-        print()
-        print("The build will fail due to this.")
-        exit(1)
-
 
 def read_current_status(current_commit, path):
     # type: (str, str) -> typing.Mapping[str, typing.Any]
@@ -280,21 +234,6 @@ def update_latest(
 try:
     if __name__ != '__main__':
         exit(0)
-    repo = os.environ.get('TOOLSTATE_VALIDATE_MAINTAINERS_REPO')
-    if repo:
-        github_token = os.environ.get('TOOLSTATE_REPO_ACCESS_TOKEN')
-        if github_token:
-            # FIXME: This is currently broken. Starting on 2021-09-15, GitHub
-            # seems to have changed it so that to list the collaborators
-            # requires admin permissions. I think this will probably just need
-            # to be removed since we are probably not going to use an admin
-            # token, and I don't see another way to do this.
-            print('maintainer validation disabled')
-            # validate_maintainers(repo, github_token)
-        else:
-            print('skipping toolstate maintainers validation since no GitHub token is present')
-        # When validating maintainers don't run the full script.
-        exit(0)
 
     cur_commit = sys.argv[1]
     cur_datetime = datetime.datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%SZ')
diff --git a/src/tools/rustfmt/.github/workflows/check_diff.yml b/src/tools/rustfmt/.github/workflows/check_diff.yml
new file mode 100644
index 00000000000..8bfb5834519
--- /dev/null
+++ b/src/tools/rustfmt/.github/workflows/check_diff.yml
@@ -0,0 +1,33 @@
+name: Diff Check
+on:
+  workflow_dispatch:
+    inputs:
+      clone_url:
+        description: 'Git url of a rustfmt fork to compare against the latest master rustfmt'
+        required: true
+      branch_name:
+        description: 'Name of the feature branch on the forked repo'
+        required: true
+      commit_hash:
+        description: 'Optional commit hash from the feature branch'
+        required: false
+      rustfmt_configs:
+        description: 'Optional comma separated list of rustfmt config options to pass when running the feature branch'
+        required: false
+
+jobs:
+  diff_check:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: checkout
+      uses: actions/checkout@v3
+
+    - name: install rustup
+      run: |
+        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs > rustup-init.sh
+        sh rustup-init.sh -y --default-toolchain none
+        rustup target add x86_64-unknown-linux-gnu
+
+    - name: check diff
+      run: bash ${GITHUB_WORKSPACE}/ci/check_diff.sh ${{ github.event.inputs.clone_url }} ${{ github.event.inputs.branch_name }} ${{ github.event.inputs.commit_hash }} ${{ github.event.inputs.rustfmt_configs }}
diff --git a/src/tools/rustfmt/.github/workflows/integration.yml b/src/tools/rustfmt/.github/workflows/integration.yml
index 4d8899b434b..314ce0e84c6 100644
--- a/src/tools/rustfmt/.github/workflows/integration.yml
+++ b/src/tools/rustfmt/.github/workflows/integration.yml
@@ -27,7 +27,6 @@ jobs:
           tempdir,
           futures-rs,
           rust-clippy,
-          failure,
         ]
         include:
           # Allowed Failures
@@ -63,9 +62,6 @@ jobs:
           # Original comment was: temporal build failure due to breaking changes in the nightly compiler
           - integration: rust-semverver
             allow-failure: true
-          # Can be moved back to include section after https://github.com/rust-lang-nursery/failure/pull/298 is merged
-          - integration: failure
-            allow-failure: true
 
     steps:
     - name: checkout
diff --git a/src/tools/rustfmt/CHANGELOG.md b/src/tools/rustfmt/CHANGELOG.md
index 0c1893bf8c3..60f961fa12a 100644
--- a/src/tools/rustfmt/CHANGELOG.md
+++ b/src/tools/rustfmt/CHANGELOG.md
@@ -2,6 +2,32 @@
 
 ## [Unreleased]
 
+## [1.5.2] 2023-01-24
+
+### Fixed
+
+- Resolve issue when comments are found within const generic defaults in unit structs [#5668](https://github.com/rust-lang/rustfmt/issues/5668)
+- Resolve issue when block comments are found within trait generics [#5358](https://github.com/rust-lang/rustfmt/issues/5358)
+- Correctly handle alignment of comments containing unicode characters [#5504](https://github.com/rust-lang/rustfmt/issues/5504)
+- Properly indent a single generic bound that requires being written across multiple lines [#4689](https://github.com/rust-lang/rustfmt/issues/4689) (n.b. this change is version gated and will only appear when the `version` configuration option is set to `Two`)
+
+### Changed
+
+- Renamed `fn_args_layout` configuration option to `fn_params_layout` [#4149](https://github.com/rust-lang/rustfmt/issues/4149). Note that `fn_args_layout` has only been soft deprecated: `fn_args_layout` will continue to work without issue, but rustfmt will display a warning to encourage users to switch to the new name
+
+### Added
+
+- New configuration option (`skip_macro_invocations`)[https://rust-lang.github.io/rustfmt/?version=master&search=#skip_macro_invocations] [#5347](https://github.com/rust-lang/rustfmt/pull/5347) that can be used to globally define a single enumerated list of macro calls that rustfmt should skip formatting. rustfmt [currently also supports this via a custom tool attribute](https://github.com/rust-lang/rustfmt#tips), however, these cannot be used in all contexts because [custom inner attributes are unstable](https://github.com/rust-lang/rust/issues/54726)
+
+### Misc
+
+- rustfmt now internally supports the ability to have both stable and unstable variants of a configuration option [#5378](https://github.com/rust-lang/rustfmt/issues/5378). This ability will allow the rustfmt team to make certain configuration options available on stable toolchains more quickly because we no longer have to wait for _every_ variant to be stable-ready before stabilizing _any_ variant. 
+
+### Install/Download Options
+- **rustup (nightly)** - nightly-2023-01-24
+- **GitHub Release Binaries** - [Release v1.5.2](https://github.com/rust-lang/rustfmt/releases/tag/v1.5.2)
+- **Build from source** - [Tag v1.5.2](https://github.com/rust-lang/rustfmt/tree/v1.5.2), see instructions for how to [install rustfmt from source][install-from-source]
+
 ## [1.5.1] 2022-06-24
 
 **N.B** A bug was introduced in v1.5.0/nightly-2022-06-15 which modified formatting. If you happened to run rustfmt over your code with one of those ~10 nightlies it's possible you may have seen formatting changes, and you may see additional changes after this fix since that bug has now been reverted.
@@ -840,7 +866,7 @@ from formatting an attribute #3665
 - Fix formatting of raw string literals #2983
 - Handle chain with try operators with spaces #2986
 - Use correct shape in Visual tuple rewriting #2987
-- Impove formatting of arguments with `visual_style = "Visual"` option #2988
+- Improve formatting of arguments with `visual_style = "Visual"` option #2988
 - Change `print_diff` to output the correct line number 992b179
 - Propagate errors about failing to rewrite a macro 6f318e3
 - Handle formatting of long function signature #3010
diff --git a/src/tools/rustfmt/Cargo.lock b/src/tools/rustfmt/Cargo.lock
index 311df226da1..24166d51c51 100644
--- a/src/tools/rustfmt/Cargo.lock
+++ b/src/tools/rustfmt/Cargo.lock
@@ -476,7 +476,7 @@ checksum = "fc71d2faa173b74b232dedc235e3ee1696581bb132fc116fa3626d6151a1a8fb"
 
 [[package]]
 name = "rustfmt-config_proc_macro"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -485,7 +485,7 @@ dependencies = [
 
 [[package]]
 name = "rustfmt-nightly"
-version = "1.5.1"
+version = "1.5.2"
 dependencies = [
  "annotate-snippets",
  "anyhow",
diff --git a/src/tools/rustfmt/Cargo.toml b/src/tools/rustfmt/Cargo.toml
index 7a4e02d69ed..87ce59d0217 100644
--- a/src/tools/rustfmt/Cargo.toml
+++ b/src/tools/rustfmt/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 
 name = "rustfmt-nightly"
-version = "1.5.1"
+version = "1.5.2"
 description = "Tool to find and fix Rust formatting issues"
 repository = "https://github.com/rust-lang/rustfmt"
 readme = "README.md"
@@ -57,7 +57,7 @@ unicode-segmentation = "1.9"
 unicode-width = "0.1"
 unicode_categories = "0.1"
 
-rustfmt-config_proc_macro = { version = "0.2", path = "config_proc_macro" }
+rustfmt-config_proc_macro = { version = "0.3", path = "config_proc_macro" }
 
 # A noop dependency that changes in the Rust repository, it's a bit of a hack.
 # See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`
diff --git a/src/tools/rustfmt/Configurations.md b/src/tools/rustfmt/Configurations.md
index 8b96b9d3689..49e7e4e6489 100644
--- a/src/tools/rustfmt/Configurations.md
+++ b/src/tools/rustfmt/Configurations.md
@@ -1,6 +1,6 @@
 # Configuring Rustfmt
 
-Rustfmt is designed to be very configurable. You can create a TOML file called `rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent directory and it will apply the options in that file. If none of these directories contain such a file, both your home directory and a directory called `rustfmt` in your [global config directory](https://docs.rs/dirs/1.0.4/dirs/fn.config_dir.html) (e.g. `.config/rustfmt/`) are checked as well.
+Rustfmt is designed to be very configurable. You can create a TOML file called `rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent directory and it will apply the options in that file. If none of these directories contain such a file, both your home directory and a directory called `rustfmt` in your [global config directory](https://docs.rs/dirs/4.0.0/dirs/fn.config_dir.html) (e.g. `.config/rustfmt/`) are checked as well.
 
 A possible content of `rustfmt.toml` or `.rustfmt.toml` might look like this:
 
@@ -425,7 +425,7 @@ fn example() {
 
 ## `comment_width`
 
-Maximum length of comments. No effect unless`wrap_comments = true`.
+Maximum length of comments. No effect unless `wrap_comments = true`.
 
 - **Default value**: `80`
 - **Possible values**: any positive integer
@@ -589,7 +589,7 @@ doesn't get ignored when aligning.
 #### `0` (default):
 
 ```rust
-enum Bar {
+enum Foo {
     A = 0,
     Bb = 1,
     RandomLongVariantGoesHere = 10,
@@ -645,7 +645,8 @@ trailing whitespaces.
 
 ## `fn_args_layout`
 
-Control the layout of arguments in a function
+This option is deprecated and has been renamed to `fn_params_layout` to better communicate that
+it affects the layout of parameters in function signatures.
 
 - **Default value**: `"Tall"`
 - **Possible values**: `"Compressed"`, `"Tall"`, `"Vertical"`
@@ -753,6 +754,8 @@ trait Lorem {
 }
 ```
 
+See also [`fn_params_layout`](#fn_params_layout)
+
 ## `fn_call_width`
 
 Maximum width of the args of a function call before falling back to vertical formatting.
@@ -765,6 +768,117 @@ By default this option is set as a percentage of [`max_width`](#max_width) provi
 
 See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
 
+## `fn_params_layout`
+
+Control the layout of parameters in function signatures.
+
+- **Default value**: `"Tall"`
+- **Possible values**: `"Compressed"`, `"Tall"`, `"Vertical"`
+- **Stable**: Yes
+
+#### `"Tall"` (default):
+
+```rust
+trait Lorem {
+    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);
+
+    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
+        // body
+    }
+
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+        consectetur: Consectetur,
+        adipiscing: Adipiscing,
+        elit: Elit,
+    );
+
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+        consectetur: Consectetur,
+        adipiscing: Adipiscing,
+        elit: Elit,
+    ) {
+        // body
+    }
+}
+```
+
+#### `"Compressed"`:
+
+```rust
+trait Lorem {
+    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);
+
+    fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
+        // body
+    }
+
+    fn lorem(
+        ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
+        adipiscing: Adipiscing, elit: Elit,
+    );
+
+    fn lorem(
+        ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
+        adipiscing: Adipiscing, elit: Elit,
+    ) {
+        // body
+    }
+}
+```
+
+#### `"Vertical"`:
+
+```rust
+trait Lorem {
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+    );
+
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+    ) {
+        // body
+    }
+
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+        consectetur: Consectetur,
+        adipiscing: Adipiscing,
+        elit: Elit,
+    );
+
+    fn lorem(
+        ipsum: Ipsum,
+        dolor: Dolor,
+        sit: Sit,
+        amet: Amet,
+        consectetur: Consectetur,
+        adipiscing: Adipiscing,
+        elit: Elit,
+    ) {
+        // body
+    }
+}
+```
+
+
 ## `fn_single_line`
 
 Put single-expression functions on a single line
@@ -1014,6 +1128,62 @@ macro_rules! foo {
 
 See also [`format_macro_matchers`](#format_macro_matchers).
 
+## `skip_macro_invocations`
+
+Skip formatting the bodies of macro invocations with the following names.
+
+rustfmt will not format any macro invocation for macros with names set in this list.
+Including the special value "*" will prevent any macro invocations from being formatted.
+
+Note: This option does not have any impact on how rustfmt formats macro definitions.
+
+- **Default value**: `[]`
+- **Possible values**: a list of macro name idents, `["name_0", "name_1", ..., "*"]`
+- **Stable**: No (tracking issue: [#5346](https://github.com/rust-lang/rustfmt/issues/5346))
+
+#### `[]` (default):
+
+rustfmt will follow its standard approach to formatting macro invocations.
+
+No macro invocations will be skipped based on their name. More information about rustfmt's standard macro invocation formatting behavior can be found in [#5437](https://github.com/rust-lang/rustfmt/discussions/5437).
+
+```rust
+lorem!(
+    const _: u8 = 0;
+);
+
+ipsum!(
+    const _: u8 = 0;
+);
+```
+
+#### `["lorem"]`:
+
+The named macro invocations will be skipped.
+
+```rust
+lorem!(
+        const _: u8 = 0;
+);
+
+ipsum!(
+    const _: u8 = 0;
+);
+```
+
+#### `["*"]`:
+
+The special selector `*` will skip all macro invocations.
+
+```rust
+lorem!(
+        const _: u8 = 0;
+);
+
+ipsum!(
+        const _: u8 = 0;
+);
+```
 
 ## `format_strings`
 
@@ -1687,13 +1857,16 @@ pub enum Foo {}
 
 ## `imports_granularity`
 
-How imports should be grouped into `use` statements. Imports will be merged or split to the configured level of granularity.
+Controls how imports are structured in `use` statements. Imports will be merged or split to the configured level of granularity.
+
+Similar to other `import` related configuration options, this option operates within the bounds of user-defined groups of imports. See [`group_imports`](#group_imports) for more information on import groups.
+
+Note that rustfmt will not modify the granularity of imports containing comments if doing so could potentially lose or misplace said comments.
 
 - **Default value**: `Preserve`
 - **Possible values**: `Preserve`, `Crate`, `Module`, `Item`, `One`
 - **Stable**: No (tracking issue: [#4991](https://github.com/rust-lang/rustfmt/issues/4991))
 
-Note that rustfmt will not modify the granularity of imports containing comments if doing so could potentially lose or misplace said comments.
 
 #### `Preserve` (default):
 
diff --git a/src/tools/rustfmt/Processes.md b/src/tools/rustfmt/Processes.md
index f763b5714ce..61abc87eec9 100644
--- a/src/tools/rustfmt/Processes.md
+++ b/src/tools/rustfmt/Processes.md
@@ -2,7 +2,7 @@ This document outlines processes regarding management of rustfmt.
 
 # Stabilising an Option
 
-In this Section, we describe how to stabilise an option of the rustfmt's configration.
+In this Section, we describe how to stabilise an option of the rustfmt's configuration.
 
 ## Conditions
 
diff --git a/src/tools/rustfmt/ci/build_and_test.bat b/src/tools/rustfmt/ci/build_and_test.bat
index ef41017783f..69dae1fff7b 100755
--- a/src/tools/rustfmt/ci/build_and_test.bat
+++ b/src/tools/rustfmt/ci/build_and_test.bat
@@ -1,4 +1,5 @@
 set "RUSTFLAGS=-D warnings"
+set "RUSTFMT_CI=1"
 
 :: Print version information
 rustc -Vv || exit /b 1
diff --git a/src/tools/rustfmt/ci/build_and_test.sh b/src/tools/rustfmt/ci/build_and_test.sh
index 8fa0f67b0d0..94991853263 100755
--- a/src/tools/rustfmt/ci/build_and_test.sh
+++ b/src/tools/rustfmt/ci/build_and_test.sh
@@ -3,6 +3,7 @@
 set -euo pipefail
 
 export RUSTFLAGS="-D warnings"
+export RUSTFMT_CI=1
 
 # Print version information
 rustc -Vv
diff --git a/src/tools/rustfmt/ci/check_diff.sh b/src/tools/rustfmt/ci/check_diff.sh
new file mode 100755
index 00000000000..062c2dd8673
--- /dev/null
+++ b/src/tools/rustfmt/ci/check_diff.sh
@@ -0,0 +1,199 @@
+#!/bin/bash
+
+function print_usage() {
+    echo "usage check_diff REMOTE_REPO FEATURE_BRANCH [COMMIT_HASH] [OPTIONAL_RUSTFMT_CONFIGS]"
+}
+
+if [ $# -le 1 ]; then
+    print_usage
+    exit 1
+fi
+
+REMOTE_REPO=$1
+FEATURE_BRANCH=$2
+OPTIONAL_COMMIT_HASH=$3
+OPTIONAL_RUSTFMT_CONFIGS=$4
+
+# OUTPUT array used to collect all the status of running diffs on various repos
+STATUSES=()
+
+# Clone a git repository and cd into it.
+#
+# Parameters:
+# $1: git clone url
+# $2: directory where the repo should be cloned
+function clone_repo() {
+    GIT_TERMINAL_PROMPT=0 git clone --quiet $1 --depth 1 $2 && cd $2
+}
+
+# Initialize Git submoduels for the repo.
+#
+# Parameters
+# $1: list of directories to initialize
+function init_submodules() {
+    git submodule update --init $1
+}
+
+# Run rusfmt with the --check flag to see if a diff is produced.
+#
+# Parameters:
+# $1: Path to a rustfmt binary
+# $2: Output file path for the diff
+# $3: Any additional configuration options to pass to rustfmt
+#
+# Globlas:
+# $OPTIONAL_RUSTFMT_CONFIGS: Optional configs passed to the script from $4
+function create_diff() {
+    local config;
+    if [ -z "$3" ]; then
+        config="--config=error_on_line_overflow=false,error_on_unformatted=false"
+    else
+        config="--config=error_on_line_overflow=false,error_on_unformatted=false,$OPTIONAL_RUSTFMT_CONFIGS"
+    fi
+
+    for i in `find . | grep "\.rs$"`
+    do
+        $1 --unstable-features --skip-children --check --color=always $config $i >> $2 2>/dev/null
+    done
+}
+
+# Run the master rustfmt binary and the feature branch binary in the current directory and compare the diffs
+#
+# Parameters
+# $1: Name of the repository (used for logging)
+#
+# Globlas:
+# $RUSFMT_BIN: Path to the rustfmt master binary. Created when running `compile_rustfmt`
+# $FEATURE_BIN: Path to the rustfmt feature binary. Created when running `compile_rustfmt`
+# $OPTIONAL_RUSTFMT_CONFIGS: Optional configs passed to the script from $4
+function check_diff() {
+    echo "running rustfmt (master) on $1"
+    create_diff $RUSFMT_BIN rustfmt_diff.txt
+
+    echo "running rustfmt (feature) on $1"
+    create_diff $FEATURE_BIN feature_diff.txt $OPTIONAL_RUSTFMT_CONFIGS
+
+    echo "checking diff"
+    local diff;
+    # we don't add color to the diff since we added color when running rustfmt --check.
+    # tail -n + 6 removes the git diff header info
+    # cut -c 2- removes the leading diff characters("+","-"," ") from running git diff.
+    # Again, the diff output we care about was already added when we ran rustfmt --check
+    diff=$(
+        git --no-pager diff --color=never \
+        --unified=0 --no-index rustfmt_diff.txt feature_diff.txt 2>&1 | tail -n +6 | cut -c 2-
+    )
+
+    if [ -z "$diff" ]; then
+        echo "no diff detected between rustfmt and the feture branch"
+        return 0
+    else
+        echo "$diff"
+        return 1
+    fi
+}
+
+# Compiles and produces two rustfmt binaries.
+# One for the current master, and another for the feature branch
+#
+# Parameters:
+# $1: Directory where rustfmt will be cloned
+#
+# Globlas:
+# $REMOTE_REPO: Clone URL to the rustfmt fork that we want to test
+# $FEATURE_BRANCH: Name of the feature branch
+# $OPTIONAL_COMMIT_HASH: Optional commit hash that will be checked out if provided
+function compile_rustfmt() {
+    RUSTFMT_REPO="https://github.com/rust-lang/rustfmt.git"
+    clone_repo $RUSTFMT_REPO $1
+    git remote add feature $REMOTE_REPO
+    git fetch feature $FEATURE_BRANCH
+
+    cargo build --release --bin rustfmt && cp target/release/rustfmt $1/rustfmt
+    if [ -z "$OPTIONAL_COMMIT_HASH" ]; then
+        git switch $FEATURE_BRANCH
+    else
+        git switch $OPTIONAL_COMMIT_HASH --detach
+    fi
+    cargo build --release --bin rustfmt && cp target/release/rustfmt $1/feature_rustfmt
+    RUSFMT_BIN=$1/rustfmt
+    FEATURE_BIN=$1/feature_rustfmt
+}
+
+# Check the diff for running rustfmt and the feature branch on all the .rs files in the repo.
+#
+# Parameters
+# $1: Clone URL for the repo
+# $2: Name of the repo (mostly used for logging)
+# $3: Path to any submodules that should be initialized
+function check_repo() {
+    WORKDIR=$(pwd)
+    REPO_URL=$1
+    REPO_NAME=$2
+    SUBMODULES=$3
+
+    local tmp_dir;
+    tmp_dir=$(mktemp -d -t $REPO_NAME-XXXXXXXX)
+    clone_repo $REPO_URL $tmp_dir
+
+    if [ ! -z "$SUBMODULES" ]; then
+        init_submodules $SUBMODULES
+    fi
+
+    check_diff $REPO_NAME
+    # append the status of running `check_diff` to the STATUSES array
+    STATUSES+=($?)
+
+    echo "removing tmp_dir $tmp_dir"
+    rm -rf $tmp_dir
+    cd $WORKDIR
+}
+
+function main() {
+    tmp_dir=$(mktemp -d -t rustfmt-XXXXXXXX)
+    echo Created tmp_dir $tmp_dir
+
+    compile_rustfmt $tmp_dir
+
+    # run checks
+    check_repo "https://github.com/rust-lang/rust.git" rust-lang-rust
+    check_repo "https://github.com/rust-lang/cargo.git" cargo
+    check_repo "https://github.com/rust-lang/miri.git" miri
+    check_repo "https://github.com/rust-lang/rust-analyzer.git" rust-analyzer
+    check_repo "https://github.com/bitflags/bitflags.git" bitflags
+    check_repo "https://github.com/rust-lang/log.git" log
+    check_repo "https://github.com/rust-lang/mdBook.git" mdBook
+    check_repo "https://github.com/rust-lang/packed_simd.git" packed_simd
+    check_repo "https://github.com/rust-lang/rust-semverver.git" check_repo
+    check_repo "https://github.com/Stebalien/tempfile.git" tempfile
+    check_repo "https://github.com/rust-lang/futures-rs.git" futures-rs
+    check_repo "https://github.com/dtolnay/anyhow.git" anyhow
+    check_repo "https://github.com/dtolnay/thiserror.git" thiserror
+    check_repo "https://github.com/dtolnay/syn.git" syn
+    check_repo "https://github.com/serde-rs/serde.git" serde
+    check_repo "https://github.com/rust-lang/rustlings.git" rustlings
+    check_repo "https://github.com/rust-lang/rustup.git" rustup
+    check_repo "https://github.com/SergioBenitez/Rocket.git" Rocket
+    check_repo "https://github.com/rustls/rustls.git" rustls
+    check_repo "https://github.com/rust-lang/rust-bindgen.git" rust-bindgen
+    check_repo "https://github.com/hyperium/hyper.git" hyper
+    check_repo "https://github.com/actix/actix.git" actix
+    check_repo "https://github.com/denoland/deno.git" denoland_deno
+
+    # cleanup temp dir
+    echo removing tmp_dir $tmp_dir
+    rm -rf $tmp_dir
+
+    # figure out the exit code
+    for status in ${STATUSES[@]}
+    do
+        if [ $status -eq 1 ]; then
+            echo "formatting diff found 💔"
+            return 1
+        fi
+    done
+
+    echo "no diff found 😊"
+}
+
+main
diff --git a/src/tools/rustfmt/ci/integration.sh b/src/tools/rustfmt/ci/integration.sh
index 562d5d70c70..19d502bc5c7 100755
--- a/src/tools/rustfmt/ci/integration.sh
+++ b/src/tools/rustfmt/ci/integration.sh
@@ -91,14 +91,28 @@ case ${INTEGRATION} in
         cd -
         ;;
     crater)
-        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git
+        git clone --depth=1 https://github.com/rust-lang/${INTEGRATION}.git
         cd ${INTEGRATION}
         show_head
         check_fmt_with_lib_tests
         cd -
         ;;
+    bitflags)
+        git clone --depth=1 https://github.com/bitflags/${INTEGRATION}.git
+        cd ${INTEGRATION}
+        show_head
+        check_fmt_with_all_tests
+        cd -
+        ;;
+    error-chain | tempdir)
+        git clone --depth=1 https://github.com/rust-lang-deprecated/${INTEGRATION}.git
+        cd ${INTEGRATION}
+        show_head
+        check_fmt_with_all_tests
+        cd -
+        ;;
     *)
-        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git
+        git clone --depth=1 https://github.com/rust-lang/${INTEGRATION}.git
         cd ${INTEGRATION}
         show_head
         check_fmt_with_all_tests
diff --git a/src/tools/rustfmt/config_proc_macro/Cargo.lock b/src/tools/rustfmt/config_proc_macro/Cargo.lock
index ecf561f28fb..49f2f72a8d2 100644
--- a/src/tools/rustfmt/config_proc_macro/Cargo.lock
+++ b/src/tools/rustfmt/config_proc_macro/Cargo.lock
@@ -22,7 +22,7 @@ dependencies = [
 
 [[package]]
 name = "rustfmt-config_proc_macro"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/src/tools/rustfmt/config_proc_macro/Cargo.toml b/src/tools/rustfmt/config_proc_macro/Cargo.toml
index a41b3a5e6bf..d10d0469cc4 100644
--- a/src/tools/rustfmt/config_proc_macro/Cargo.toml
+++ b/src/tools/rustfmt/config_proc_macro/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rustfmt-config_proc_macro"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2018"
 description = "A collection of procedural macros for rustfmt"
 license = "Apache-2.0/MIT"
diff --git a/src/tools/rustfmt/config_proc_macro/src/attrs.rs b/src/tools/rustfmt/config_proc_macro/src/attrs.rs
index 0baba046f9e..dd18ff572cb 100644
--- a/src/tools/rustfmt/config_proc_macro/src/attrs.rs
+++ b/src/tools/rustfmt/config_proc_macro/src/attrs.rs
@@ -1,8 +1,10 @@
 //! This module provides utilities for handling attributes on variants
-//! of `config_type` enum. Currently there are two types of attributes
-//! that could appear on the variants of `config_type` enum: `doc_hint`
-//! and `value`. Both comes in the form of name-value pair whose value
-//! is string literal.
+//! of `config_type` enum. Currently there are the following attributes
+//! that could appear on the variants of `config_type` enum:
+//!
+//! - `doc_hint`: name-value pair whose value is string literal
+//! - `value`: name-value pair whose value is string literal
+//! - `unstable_variant`: name only
 
 /// Returns the value of the first `doc_hint` attribute in the given slice or
 /// `None` if `doc_hint` attribute is not available.
@@ -27,6 +29,11 @@ pub fn find_config_value(attrs: &[syn::Attribute]) -> Option<String> {
     attrs.iter().filter_map(config_value).next()
 }
 
+/// Returns `true` if the there is at least one `unstable` attribute in the given slice.
+pub fn any_unstable_variant(attrs: &[syn::Attribute]) -> bool {
+    attrs.iter().any(is_unstable_variant)
+}
+
 /// Returns a string literal value if the given attribute is `value`
 /// attribute or `None` otherwise.
 pub fn config_value(attr: &syn::Attribute) -> Option<String> {
@@ -38,6 +45,11 @@ pub fn is_config_value(attr: &syn::Attribute) -> bool {
     is_attr_name_value(attr, "value")
 }
 
+/// Returns `true` if the given attribute is an `unstable` attribute.
+pub fn is_unstable_variant(attr: &syn::Attribute) -> bool {
+    is_attr_path(attr, "unstable_variant")
+}
+
 fn is_attr_name_value(attr: &syn::Attribute, name: &str) -> bool {
     attr.parse_meta().ok().map_or(false, |meta| match meta {
         syn::Meta::NameValue(syn::MetaNameValue { ref path, .. }) if path.is_ident(name) => true,
@@ -45,6 +57,13 @@ fn is_attr_name_value(attr: &syn::Attribute, name: &str) -> bool {
     })
 }
 
+fn is_attr_path(attr: &syn::Attribute, name: &str) -> bool {
+    attr.parse_meta().ok().map_or(false, |meta| match meta {
+        syn::Meta::Path(path) if path.is_ident(name) => true,
+        _ => false,
+    })
+}
+
 fn get_name_value_str_lit(attr: &syn::Attribute, name: &str) -> Option<String> {
     attr.parse_meta().ok().and_then(|meta| match meta {
         syn::Meta::NameValue(syn::MetaNameValue {
diff --git a/src/tools/rustfmt/config_proc_macro/src/item_enum.rs b/src/tools/rustfmt/config_proc_macro/src/item_enum.rs
index dcee77a8549..731a7ea0607 100644
--- a/src/tools/rustfmt/config_proc_macro/src/item_enum.rs
+++ b/src/tools/rustfmt/config_proc_macro/src/item_enum.rs
@@ -1,5 +1,6 @@
 use proc_macro2::TokenStream;
-use quote::quote;
+use quote::{quote, quote_spanned};
+use syn::spanned::Spanned;
 
 use crate::attrs::*;
 use crate::utils::*;
@@ -47,12 +48,23 @@ fn process_variant(variant: &syn::Variant) -> TokenStream {
     let metas = variant
         .attrs
         .iter()
-        .filter(|attr| !is_doc_hint(attr) && !is_config_value(attr));
+        .filter(|attr| !is_doc_hint(attr) && !is_config_value(attr) && !is_unstable_variant(attr));
     let attrs = fold_quote(metas, |meta| quote!(#meta));
     let syn::Variant { ident, fields, .. } = variant;
     quote!(#attrs #ident #fields)
 }
 
+/// Return the correct syntax to pattern match on the enum variant, discarding all
+/// internal field data.
+fn fields_in_variant(variant: &syn::Variant) -> TokenStream {
+    // With thanks to https://stackoverflow.com/a/65182902
+    match &variant.fields {
+        syn::Fields::Unnamed(_) => quote_spanned! { variant.span() => (..) },
+        syn::Fields::Unit => quote_spanned! { variant.span() => },
+        syn::Fields::Named(_) => quote_spanned! { variant.span() => {..} },
+    }
+}
+
 fn impl_doc_hint(ident: &syn::Ident, variants: &Variants) -> TokenStream {
     let doc_hint = variants
         .iter()
@@ -60,12 +72,26 @@ fn impl_doc_hint(ident: &syn::Ident, variants: &Variants) -> TokenStream {
         .collect::<Vec<_>>()
         .join("|");
     let doc_hint = format!("[{}]", doc_hint);
+
+    let variant_stables = variants
+        .iter()
+        .map(|v| (&v.ident, fields_in_variant(&v), !unstable_of_variant(v)));
+    let match_patterns = fold_quote(variant_stables, |(v, fields, stable)| {
+        quote! {
+            #ident::#v #fields => #stable,
+        }
+    });
     quote! {
         use crate::config::ConfigType;
         impl ConfigType for #ident {
             fn doc_hint() -> String {
                 #doc_hint.to_owned()
             }
+            fn stable_variant(&self) -> bool {
+                match self {
+                    #match_patterns
+                }
+            }
         }
     }
 }
@@ -123,13 +149,21 @@ fn impl_from_str(ident: &syn::Ident, variants: &Variants) -> TokenStream {
 }
 
 fn doc_hint_of_variant(variant: &syn::Variant) -> String {
-    find_doc_hint(&variant.attrs).unwrap_or(variant.ident.to_string())
+    let mut text = find_doc_hint(&variant.attrs).unwrap_or(variant.ident.to_string());
+    if unstable_of_variant(&variant) {
+        text.push_str(" (unstable)")
+    };
+    text
 }
 
 fn config_value_of_variant(variant: &syn::Variant) -> String {
     find_config_value(&variant.attrs).unwrap_or(variant.ident.to_string())
 }
 
+fn unstable_of_variant(variant: &syn::Variant) -> bool {
+    any_unstable_variant(&variant.attrs)
+}
+
 fn impl_serde(ident: &syn::Ident, variants: &Variants) -> TokenStream {
     let arms = fold_quote(variants.iter(), |v| {
         let v_ident = &v.ident;
diff --git a/src/tools/rustfmt/config_proc_macro/src/lib.rs b/src/tools/rustfmt/config_proc_macro/src/lib.rs
index e772c53f423..0c54c132c97 100644
--- a/src/tools/rustfmt/config_proc_macro/src/lib.rs
+++ b/src/tools/rustfmt/config_proc_macro/src/lib.rs
@@ -69,3 +69,16 @@ pub fn stable_only_test(_args: TokenStream, input: TokenStream) -> TokenStream {
         TokenStream::from_str("").unwrap()
     }
 }
+
+/// Used to conditionally output the TokenStream for tests that should be run as part of rustfmts
+/// test suite, but should be ignored when running in the rust-lang/rust test suite.
+#[proc_macro_attribute]
+pub fn rustfmt_only_ci_test(_args: TokenStream, input: TokenStream) -> TokenStream {
+    if option_env!("RUSTFMT_CI").is_some() {
+        input
+    } else {
+        let mut token_stream = TokenStream::from_str("#[ignore]").unwrap();
+        token_stream.extend(input);
+        token_stream
+    }
+}
diff --git a/src/tools/rustfmt/config_proc_macro/tests/smoke.rs b/src/tools/rustfmt/config_proc_macro/tests/smoke.rs
index 940a8a0c251..c8a83e39c9e 100644
--- a/src/tools/rustfmt/config_proc_macro/tests/smoke.rs
+++ b/src/tools/rustfmt/config_proc_macro/tests/smoke.rs
@@ -1,6 +1,7 @@
 pub mod config {
     pub trait ConfigType: Sized {
         fn doc_hint() -> String;
+        fn stable_variant(&self) -> bool;
     }
 }
 
diff --git a/src/tools/rustfmt/rust-toolchain b/src/tools/rustfmt/rust-toolchain
index 2640a9e0ecc..22283b3d620 100644
--- a/src/tools/rustfmt/rust-toolchain
+++ b/src/tools/rustfmt/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2022-06-21"
-components = ["rustc-dev"]
+channel = "nightly-2023-01-24"
+components = ["llvm-tools", "rustc-dev"]
diff --git a/src/tools/rustfmt/src/attr.rs b/src/tools/rustfmt/src/attr.rs
index c503eeeb9b3..5648e1254ed 100644
--- a/src/tools/rustfmt/src/attr.rs
+++ b/src/tools/rustfmt/src/attr.rs
@@ -336,7 +336,7 @@ impl Rewrite for ast::Attribute {
         } else {
             let should_skip = self
                 .ident()
-                .map(|s| context.skip_context.skip_attribute(s.name.as_str()))
+                .map(|s| context.skip_context.attributes.skip(s.name.as_str()))
                 .unwrap_or(false);
             let prefix = attr_prefix(self);
 
@@ -390,7 +390,7 @@ impl Rewrite for [ast::Attribute] {
 
         // Determine if the source text is annotated with `#[rustfmt::skip::attributes(derive)]`
         // or `#![rustfmt::skip::attributes(derive)]`
-        let skip_derives = context.skip_context.skip_attribute("derive");
+        let skip_derives = context.skip_context.attributes.skip("derive");
 
         // This is not just a simple map because we need to handle doc comments
         // (where we take as many doc comment attributes as possible) and possibly
diff --git a/src/tools/rustfmt/src/bin/main.rs b/src/tools/rustfmt/src/bin/main.rs
index 8e871e61f26..be64559e877 100644
--- a/src/tools/rustfmt/src/bin/main.rs
+++ b/src/tools/rustfmt/src/bin/main.rs
@@ -136,7 +136,7 @@ fn make_opts() -> Options {
         "l",
         "files-with-diff",
         "Prints the names of mismatched files that were formatted. Prints the names of \
-         files that would be formated when used with `--check` mode. ",
+         files that would be formatted when used with `--check` mode. ",
     );
     opts.optmulti(
         "",
diff --git a/src/tools/rustfmt/src/cargo-fmt/main.rs b/src/tools/rustfmt/src/cargo-fmt/main.rs
index 9031d29b45f..2b714b68df0 100644
--- a/src/tools/rustfmt/src/cargo-fmt/main.rs
+++ b/src/tools/rustfmt/src/cargo-fmt/main.rs
@@ -198,12 +198,10 @@ fn convert_message_format_to_rustfmt_args(
             Ok(())
         }
         "human" => Ok(()),
-        _ => {
-            return Err(format!(
-                "invalid --message-format value: {}. Allowed values are: short|json|human",
-                message_format
-            ));
-        }
+        _ => Err(format!(
+            "invalid --message-format value: {}. Allowed values are: short|json|human",
+            message_format
+        )),
     }
 }
 
@@ -215,7 +213,7 @@ fn print_usage_to_stderr(reason: &str) {
         .expect("failed to write to stderr");
 }
 
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Verbosity {
     Verbose,
     Normal,
diff --git a/src/tools/rustfmt/src/cargo-fmt/test/mod.rs b/src/tools/rustfmt/src/cargo-fmt/test/mod.rs
index 56e52fbabb6..696326e4f94 100644
--- a/src/tools/rustfmt/src/cargo-fmt/test/mod.rs
+++ b/src/tools/rustfmt/src/cargo-fmt/test/mod.rs
@@ -70,9 +70,9 @@ fn mandatory_separator() {
             .is_err()
     );
     assert!(
-        !Opts::command()
+        Opts::command()
             .try_get_matches_from(&["test", "--", "--emit"])
-            .is_err()
+            .is_ok()
     );
 }
 
diff --git a/src/tools/rustfmt/src/chains.rs b/src/tools/rustfmt/src/chains.rs
index a1a73cf4bd5..39b8d687809 100644
--- a/src/tools/rustfmt/src/chains.rs
+++ b/src/tools/rustfmt/src/chains.rs
@@ -70,10 +70,64 @@ use crate::rewrite::{Rewrite, RewriteContext};
 use crate::shape::Shape;
 use crate::source_map::SpanUtils;
 use crate::utils::{
-    self, first_line_width, last_line_extendable, last_line_width, mk_sp, rewrite_ident,
-    trimmed_last_line_width, wrap_str,
+    self, filtered_str_fits, first_line_width, last_line_extendable, last_line_width, mk_sp,
+    rewrite_ident, trimmed_last_line_width, wrap_str,
 };
 
+/// Provides the original input contents from the span
+/// of a chain element with trailing spaces trimmed.
+fn format_overflow_style(span: Span, context: &RewriteContext<'_>) -> Option<String> {
+    context.snippet_provider.span_to_snippet(span).map(|s| {
+        s.lines()
+            .map(|l| l.trim_end())
+            .collect::<Vec<_>>()
+            .join("\n")
+    })
+}
+
+fn format_chain_item(
+    item: &ChainItem,
+    context: &RewriteContext<'_>,
+    rewrite_shape: Shape,
+    allow_overflow: bool,
+) -> Option<String> {
+    if allow_overflow {
+        item.rewrite(context, rewrite_shape)
+            .or_else(|| format_overflow_style(item.span, context))
+    } else {
+        item.rewrite(context, rewrite_shape)
+    }
+}
+
+fn get_block_child_shape(
+    prev_ends_with_block: bool,
+    context: &RewriteContext<'_>,
+    shape: Shape,
+) -> Shape {
+    if prev_ends_with_block {
+        shape.block_indent(0)
+    } else {
+        shape.block_indent(context.config.tab_spaces())
+    }
+    .with_max_width(context.config)
+}
+
+fn get_visual_style_child_shape(
+    context: &RewriteContext<'_>,
+    shape: Shape,
+    offset: usize,
+    parent_overflowing: bool,
+) -> Option<Shape> {
+    if !parent_overflowing {
+        shape
+            .with_max_width(context.config)
+            .offset_left(offset)
+            .map(|s| s.visual_indent(0))
+    } else {
+        Some(shape.visual_indent(offset))
+    }
+}
+
 pub(crate) fn rewrite_chain(
     expr: &ast::Expr,
     context: &RewriteContext<'_>,
@@ -496,6 +550,8 @@ struct ChainFormatterShared<'a> {
     // The number of children in the chain. This is not equal to `self.children.len()`
     // because `self.children` will change size as we process the chain.
     child_count: usize,
+    // Whether elements are allowed to overflow past the max_width limit
+    allow_overflow: bool,
 }
 
 impl<'a> ChainFormatterShared<'a> {
@@ -505,6 +561,8 @@ impl<'a> ChainFormatterShared<'a> {
             rewrites: Vec::with_capacity(chain.children.len() + 1),
             fits_single_line: false,
             child_count: chain.children.len(),
+            // TODO(calebcartwright)
+            allow_overflow: false,
         }
     }
 
@@ -517,6 +575,14 @@ impl<'a> ChainFormatterShared<'a> {
         }
     }
 
+    fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
+        for item in &self.children[..self.children.len() - 1] {
+            let rewrite = format_chain_item(item, context, child_shape, self.allow_overflow)?;
+            self.rewrites.push(rewrite);
+        }
+        Some(())
+    }
+
     // Rewrite the last child. The last child of a chain requires special treatment. We need to
     // know whether 'overflowing' the last child make a better formatting:
     //
@@ -729,22 +795,12 @@ impl<'a> ChainFormatter for ChainFormatterBlock<'a> {
     }
 
     fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
-        Some(
-            if self.root_ends_with_block {
-                shape.block_indent(0)
-            } else {
-                shape.block_indent(context.config.tab_spaces())
-            }
-            .with_max_width(context.config),
-        )
+        let block_end = self.root_ends_with_block;
+        Some(get_block_child_shape(block_end, context, shape))
     }
 
     fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
-        for item in &self.shared.children[..self.shared.children.len() - 1] {
-            let rewrite = item.rewrite(context, child_shape)?;
-            self.shared.rewrites.push(rewrite);
-        }
-        Some(())
+        self.shared.format_children(context, child_shape)
     }
 
     fn format_last_child(
@@ -808,15 +864,14 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
                 .visual_indent(self.offset)
                 .sub_width(self.offset)?;
             let rewrite = item.rewrite(context, child_shape)?;
-            match wrap_str(rewrite, context.config.max_width(), shape) {
-                Some(rewrite) => root_rewrite.push_str(&rewrite),
-                None => {
-                    // We couldn't fit in at the visual indent, try the last
-                    // indent.
-                    let rewrite = item.rewrite(context, parent_shape)?;
-                    root_rewrite.push_str(&rewrite);
-                    self.offset = 0;
-                }
+            if filtered_str_fits(&rewrite, context.config.max_width(), shape) {
+                root_rewrite.push_str(&rewrite);
+            } else {
+                // We couldn't fit in at the visual indent, try the last
+                // indent.
+                let rewrite = item.rewrite(context, parent_shape)?;
+                root_rewrite.push_str(&rewrite);
+                self.offset = 0;
             }
 
             self.shared.children = &self.shared.children[1..];
@@ -827,18 +882,17 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
     }
 
     fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
-        shape
-            .with_max_width(context.config)
-            .offset_left(self.offset)
-            .map(|s| s.visual_indent(0))
+        get_visual_style_child_shape(
+            context,
+            shape,
+            self.offset,
+            // TODO(calebcartwright): self.shared.permissibly_overflowing_parent,
+            false,
+        )
     }
 
     fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()> {
-        for item in &self.shared.children[..self.shared.children.len() - 1] {
-            let rewrite = item.rewrite(context, child_shape)?;
-            self.shared.rewrites.push(rewrite);
-        }
-        Some(())
+        self.shared.format_children(context, child_shape)
     }
 
     fn format_last_child(
diff --git a/src/tools/rustfmt/src/config/config_type.rs b/src/tools/rustfmt/src/config/config_type.rs
index c5e61658ad1..54ca7676dfc 100644
--- a/src/tools/rustfmt/src/config/config_type.rs
+++ b/src/tools/rustfmt/src/config/config_type.rs
@@ -1,4 +1,5 @@
 use crate::config::file_lines::FileLines;
+use crate::config::macro_names::MacroSelectors;
 use crate::config::options::{IgnoreList, WidthHeuristics};
 
 /// Trait for types that can be used in `Config`.
@@ -6,6 +7,14 @@ pub(crate) trait ConfigType: Sized {
     /// Returns hint text for use in `Config::print_docs()`. For enum types, this is a
     /// pipe-separated list of variants; for other types it returns `<type>`.
     fn doc_hint() -> String;
+
+    /// Return `true` if the variant (i.e. value of this type) is stable.
+    ///
+    /// By default, return true for all values. Enums annotated with `#[config_type]`
+    /// are automatically implemented, based on the `#[unstable_variant]` annotation.
+    fn stable_variant(&self) -> bool {
+        true
+    }
 }
 
 impl ConfigType for bool {
@@ -38,6 +47,12 @@ impl ConfigType for FileLines {
     }
 }
 
+impl ConfigType for MacroSelectors {
+    fn doc_hint() -> String {
+        String::from("[<string>, ...]")
+    }
+}
+
 impl ConfigType for WidthHeuristics {
     fn doc_hint() -> String {
         String::new()
@@ -51,6 +66,13 @@ impl ConfigType for IgnoreList {
 }
 
 macro_rules! create_config {
+    // Options passed in to the macro.
+    //
+    // - $i: the ident name of the option
+    // - $ty: the type of the option value
+    // - $def: the default value of the option
+    // - $stb: true if the option is stable
+    // - $dstring: description of the option
     ($($i:ident: $ty:ty, $def:expr, $stb:expr, $( $dstring:expr ),+ );+ $(;)*) => (
         #[cfg(test)]
         use std::collections::HashSet;
@@ -61,9 +83,12 @@ macro_rules! create_config {
         #[derive(Clone)]
         #[allow(unreachable_pub)]
         pub struct Config {
-            // For each config item, we store a bool indicating whether it has
-            // been accessed and the value, and a bool whether the option was
-            // manually initialised, or taken from the default,
+            // For each config item, we store:
+            //
+            // - 0: true if the value has been access
+            // - 1: true if the option was manually initialized
+            // - 2: the option value
+            // - 3: true if the option is unstable
             $($i: (Cell<bool>, bool, $ty, bool)),+
         }
 
@@ -102,6 +127,7 @@ macro_rules! create_config {
                     | "array_width"
                     | "chain_width" => self.0.set_heuristics(),
                     "merge_imports" => self.0.set_merge_imports(),
+                    "fn_args_layout" => self.0.set_fn_args_layout(),
                     &_ => (),
                 }
             }
@@ -143,24 +169,20 @@ macro_rules! create_config {
 
             fn fill_from_parsed_config(mut self, parsed: PartialConfig, dir: &Path) -> Config {
             $(
-                if let Some(val) = parsed.$i {
-                    if self.$i.3 {
+                if let Some(option_value) = parsed.$i {
+                    let option_stable = self.$i.3;
+                    if $crate::config::config_type::is_stable_option_and_value(
+                        stringify!($i), option_stable, &option_value
+                    ) {
                         self.$i.1 = true;
-                        self.$i.2 = val;
-                    } else {
-                        if crate::is_nightly_channel!() {
-                            self.$i.1 = true;
-                            self.$i.2 = val;
-                        } else {
-                            eprintln!("Warning: can't set `{} = {:?}`, unstable features are only \
-                                       available in nightly channel.", stringify!($i), val);
-                        }
+                        self.$i.2 = option_value;
                     }
                 }
             )+
                 self.set_heuristics();
                 self.set_ignore(dir);
                 self.set_merge_imports();
+                self.set_fn_args_layout();
                 self
             }
 
@@ -221,12 +243,22 @@ macro_rules! create_config {
                 match key {
                     $(
                         stringify!($i) => {
-                            self.$i.1 = true;
-                            self.$i.2 = val.parse::<$ty>()
+                            let option_value = val.parse::<$ty>()
                                 .expect(&format!("Failed to parse override for {} (\"{}\") as a {}",
                                                  stringify!($i),
                                                  val,
                                                  stringify!($ty)));
+
+                            // Users are currently allowed to set unstable
+                            // options/variants via the `--config` options override.
+                            //
+                            // There is ongoing discussion about how to move forward here:
+                            // https://github.com/rust-lang/rustfmt/pull/5379
+                            //
+                            // For now, do not validate whether the option or value is stable,
+                            // just always set it.
+                            self.$i.1 = true;
+                            self.$i.2 = option_value;
                         }
                     )+
                     _ => panic!("Unknown config key in override: {}", key)
@@ -243,14 +275,21 @@ macro_rules! create_config {
                     | "array_width"
                     | "chain_width" => self.set_heuristics(),
                     "merge_imports" => self.set_merge_imports(),
+                    "fn_args_layout" => self.set_fn_args_layout(),
                     &_ => (),
                 }
             }
 
             #[allow(unreachable_pub)]
             pub fn is_hidden_option(name: &str) -> bool {
-                const HIDE_OPTIONS: [&str; 5] =
-                    ["verbose", "verbose_diff", "file_lines", "width_heuristics", "merge_imports"];
+                const HIDE_OPTIONS: [&str; 6] = [
+                    "verbose",
+                    "verbose_diff",
+                    "file_lines",
+                    "width_heuristics",
+                    "merge_imports",
+                    "fn_args_layout"
+                ];
                 HIDE_OPTIONS.contains(&name)
             }
 
@@ -400,6 +439,18 @@ macro_rules! create_config {
                 }
             }
 
+            fn set_fn_args_layout(&mut self) {
+                if self.was_set().fn_args_layout() {
+                    eprintln!(
+                        "Warning: the `fn_args_layout` option is deprecated. \
+                        Use `fn_params_layout`. instead"
+                    );
+                    if !self.was_set().fn_params_layout() {
+                        self.fn_params_layout.2 = self.fn_args_layout();
+                    }
+                }
+            }
+
             #[allow(unreachable_pub)]
             /// Returns `true` if the config key was explicitly set and is the default value.
             pub fn is_default(&self, key: &str) -> bool {
@@ -424,3 +475,38 @@ macro_rules! create_config {
         }
     )
 }
+
+pub(crate) fn is_stable_option_and_value<T>(
+    option_name: &str,
+    option_stable: bool,
+    option_value: &T,
+) -> bool
+where
+    T: PartialEq + std::fmt::Debug + ConfigType,
+{
+    let nightly = crate::is_nightly_channel!();
+    let variant_stable = option_value.stable_variant();
+    match (nightly, option_stable, variant_stable) {
+        // Stable with an unstable option
+        (false, false, _) => {
+            eprintln!(
+                "Warning: can't set `{} = {:?}`, unstable features are only \
+                       available in nightly channel.",
+                option_name, option_value
+            );
+            false
+        }
+        // Stable with a stable option, but an unstable variant
+        (false, true, false) => {
+            eprintln!(
+                "Warning: can't set `{} = {:?}`, unstable variants are only \
+                       available in nightly channel.",
+                option_name, option_value
+            );
+            false
+        }
+        // Nightly: everything allowed
+        // Stable with stable option and variant: allowed
+        (true, _, _) | (false, true, true) => true,
+    }
+}
diff --git a/src/tools/rustfmt/src/config/macro_names.rs b/src/tools/rustfmt/src/config/macro_names.rs
new file mode 100644
index 00000000000..26ad78d6dca
--- /dev/null
+++ b/src/tools/rustfmt/src/config/macro_names.rs
@@ -0,0 +1,118 @@
+//! This module contains types and functions to support formatting specific macros.
+
+use itertools::Itertools;
+use std::{fmt, str};
+
+use serde::{Deserialize, Serialize};
+use serde_json as json;
+use thiserror::Error;
+
+/// Defines the name of a macro.
+#[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
+pub struct MacroName(String);
+
+impl MacroName {
+    pub fn new(other: String) -> Self {
+        Self(other)
+    }
+}
+
+impl fmt::Display for MacroName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl From<MacroName> for String {
+    fn from(other: MacroName) -> Self {
+        other.0
+    }
+}
+
+/// Defines a selector to match against a macro.
+#[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
+pub enum MacroSelector {
+    Name(MacroName),
+    All,
+}
+
+impl fmt::Display for MacroSelector {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Name(name) => name.fmt(f),
+            Self::All => write!(f, "*"),
+        }
+    }
+}
+
+impl str::FromStr for MacroSelector {
+    type Err = std::convert::Infallible;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "*" => MacroSelector::All,
+            name => MacroSelector::Name(MacroName(name.to_owned())),
+        })
+    }
+}
+
+/// A set of macro selectors.
+#[derive(Clone, Debug, Default, PartialEq, Deserialize, Serialize)]
+pub struct MacroSelectors(pub Vec<MacroSelector>);
+
+impl fmt::Display for MacroSelectors {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0.iter().format(", "))
+    }
+}
+
+#[derive(Error, Debug)]
+pub enum MacroSelectorsError {
+    #[error("{0}")]
+    Json(json::Error),
+}
+
+// This impl is needed for `Config::override_value` to work for use in tests.
+impl str::FromStr for MacroSelectors {
+    type Err = MacroSelectorsError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let raw: Vec<&str> = json::from_str(s).map_err(MacroSelectorsError::Json)?;
+        Ok(Self(
+            raw.into_iter()
+                .map(|raw| {
+                    MacroSelector::from_str(raw).expect("MacroSelector from_str is infallible")
+                })
+                .collect(),
+        ))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use std::str::FromStr;
+
+    #[test]
+    fn macro_names_from_str() {
+        let macro_names = MacroSelectors::from_str(r#"["foo", "*", "bar"]"#).unwrap();
+        assert_eq!(
+            macro_names,
+            MacroSelectors(
+                [
+                    MacroSelector::Name(MacroName("foo".to_owned())),
+                    MacroSelector::All,
+                    MacroSelector::Name(MacroName("bar".to_owned()))
+                ]
+                .into_iter()
+                .collect()
+            )
+        );
+    }
+
+    #[test]
+    fn macro_names_display() {
+        let macro_names = MacroSelectors::from_str(r#"["foo", "*", "bar"]"#).unwrap();
+        assert_eq!(format!("{}", macro_names), "foo, *, bar");
+    }
+}
diff --git a/src/tools/rustfmt/src/config/mod.rs b/src/tools/rustfmt/src/config/mod.rs
index f49c18d3a46..14f27f3f8b6 100644
--- a/src/tools/rustfmt/src/config/mod.rs
+++ b/src/tools/rustfmt/src/config/mod.rs
@@ -13,15 +13,20 @@ pub use crate::config::file_lines::{FileLines, FileName, Range};
 #[allow(unreachable_pub)]
 pub use crate::config::lists::*;
 #[allow(unreachable_pub)]
+pub use crate::config::macro_names::{MacroSelector, MacroSelectors};
+#[allow(unreachable_pub)]
 pub use crate::config::options::*;
 
 #[macro_use]
 pub(crate) mod config_type;
 #[macro_use]
+#[allow(unreachable_pub)]
 pub(crate) mod options;
 
 pub(crate) mod file_lines;
+#[allow(unreachable_pub)]
 pub(crate) mod lists;
+pub(crate) mod macro_names;
 
 // This macro defines configuration options used in rustfmt. Each option
 // is defined as follows:
@@ -67,6 +72,8 @@ create_config! {
     format_macro_matchers: bool, false, false,
         "Format the metavariable matching patterns in macros";
     format_macro_bodies: bool, true, false, "Format the bodies of macros";
+    skip_macro_invocations: MacroSelectors, MacroSelectors::default(), false,
+        "Skip formatting the bodies of macros invoked with the following names.";
     hex_literal_case: HexLiteralCase, HexLiteralCase::Preserve, false,
         "Format hexadecimal integer literals";
 
@@ -119,7 +126,9 @@ create_config! {
     force_multiline_blocks: bool, false, false,
         "Force multiline closure bodies and match arms to be wrapped in a block";
     fn_args_layout: Density, Density::Tall, true,
-        "Control the layout of arguments in a function";
+        "(deprecated: use fn_params_layout instead)";
+    fn_params_layout: Density, Density::Tall, true,
+        "Control the layout of parameters in function signatures.";
     brace_style: BraceStyle, BraceStyle::SameLineWhere, false, "Brace style for items";
     control_brace_style: ControlBraceStyle, ControlBraceStyle::AlwaysSameLine, false,
         "Brace style for control flow constructs";
@@ -175,7 +184,7 @@ create_config! {
     make_backup: bool, false, false, "Backup changed files";
     print_misformatted_file_names: bool, false, true,
         "Prints the names of mismatched files that were formatted. Prints the names of \
-         files that would be formated when used with `--check` mode. ";
+         files that would be formatted when used with `--check` mode. ";
 }
 
 #[derive(Error, Debug)]
@@ -191,6 +200,7 @@ impl PartialConfig {
         cloned.width_heuristics = None;
         cloned.print_misformatted_file_names = None;
         cloned.merge_imports = None;
+        cloned.fn_args_layout = None;
 
         ::toml::to_string(&cloned).map_err(ToTomlError)
     }
@@ -403,11 +413,21 @@ mod test {
     use super::*;
     use std::str;
 
+    use crate::config::macro_names::MacroName;
     use rustfmt_config_proc_macro::{nightly_only_test, stable_only_test};
 
     #[allow(dead_code)]
     mod mock {
         use super::super::*;
+        use rustfmt_config_proc_macro::config_type;
+
+        #[config_type]
+        pub(crate) enum PartiallyUnstableOption {
+            V1,
+            V2,
+            #[unstable_variant]
+            V3,
+        }
 
         create_config! {
             // Options that are used by the generated functions
@@ -427,6 +447,12 @@ mod test {
                 "Merge imports";
             merge_imports: bool, false, false, "(deprecated: use imports_granularity instead)";
 
+            // fn_args_layout renamed to fn_params_layout
+            fn_args_layout: Density, Density::Tall, true,
+                "(deprecated: use fn_params_layout instead)";
+            fn_params_layout: Density, Density::Tall, true,
+                "Control the layout of parameters in a function signatures.";
+
             // Width Heuristics
             use_small_heuristics: Heuristics, Heuristics::Default, true,
                 "Whether to use different formatting for items and \
@@ -451,6 +477,63 @@ mod test {
             // Options that are used by the tests
             stable_option: bool, false, true, "A stable option";
             unstable_option: bool, false, false, "An unstable option";
+            partially_unstable_option: PartiallyUnstableOption, PartiallyUnstableOption::V1, true,
+                "A partially unstable option";
+        }
+
+        #[cfg(test)]
+        mod partially_unstable_option {
+            use super::{Config, PartialConfig, PartiallyUnstableOption};
+            use rustfmt_config_proc_macro::{nightly_only_test, stable_only_test};
+            use std::path::Path;
+
+            /// From the config file, we can fill with a stable variant
+            #[test]
+            fn test_from_toml_stable_value() {
+                let toml = r#"
+                    partially_unstable_option = "V2"
+                "#;
+                let partial_config: PartialConfig = toml::from_str(toml).unwrap();
+                let config = Config::default();
+                let config = config.fill_from_parsed_config(partial_config, Path::new(""));
+                assert_eq!(
+                    config.partially_unstable_option(),
+                    PartiallyUnstableOption::V2
+                );
+            }
+
+            /// From the config file, we cannot fill with an unstable variant (stable only)
+            #[stable_only_test]
+            #[test]
+            fn test_from_toml_unstable_value_on_stable() {
+                let toml = r#"
+                    partially_unstable_option = "V3"
+                "#;
+                let partial_config: PartialConfig = toml::from_str(toml).unwrap();
+                let config = Config::default();
+                let config = config.fill_from_parsed_config(partial_config, Path::new(""));
+                assert_eq!(
+                    config.partially_unstable_option(),
+                    // default value from config, i.e. fill failed
+                    PartiallyUnstableOption::V1
+                );
+            }
+
+            /// From the config file, we can fill with an unstable variant (nightly only)
+            #[nightly_only_test]
+            #[test]
+            fn test_from_toml_unstable_value_on_nightly() {
+                let toml = r#"
+                    partially_unstable_option = "V3"
+                "#;
+                let partial_config: PartialConfig = toml::from_str(toml).unwrap();
+                let config = Config::default();
+                let config = config.fill_from_parsed_config(partial_config, Path::new(""));
+                assert_eq!(
+                    config.partially_unstable_option(),
+                    PartiallyUnstableOption::V3
+                );
+            }
         }
     }
 
@@ -489,6 +572,11 @@ mod test {
         assert_eq!(config.was_set().verbose(), false);
     }
 
+    const PRINT_DOCS_STABLE_OPTION: &str = "stable_option <boolean> Default: false";
+    const PRINT_DOCS_UNSTABLE_OPTION: &str = "unstable_option <boolean> Default: false (unstable)";
+    const PRINT_DOCS_PARTIALLY_UNSTABLE_OPTION: &str =
+        "partially_unstable_option [V1|V2|V3 (unstable)] Default: V1";
+
     #[test]
     fn test_print_docs_exclude_unstable() {
         use self::mock::Config;
@@ -497,10 +585,9 @@ mod test {
         Config::print_docs(&mut output, false);
 
         let s = str::from_utf8(&output).unwrap();
-
-        assert_eq!(s.contains("stable_option"), true);
-        assert_eq!(s.contains("unstable_option"), false);
-        assert_eq!(s.contains("(unstable)"), false);
+        assert_eq!(s.contains(PRINT_DOCS_STABLE_OPTION), true);
+        assert_eq!(s.contains(PRINT_DOCS_UNSTABLE_OPTION), false);
+        assert_eq!(s.contains(PRINT_DOCS_PARTIALLY_UNSTABLE_OPTION), true);
     }
 
     #[test]
@@ -511,9 +598,9 @@ mod test {
         Config::print_docs(&mut output, true);
 
         let s = str::from_utf8(&output).unwrap();
-        assert_eq!(s.contains("stable_option"), true);
-        assert_eq!(s.contains("unstable_option"), true);
-        assert_eq!(s.contains("(unstable)"), true);
+        assert_eq!(s.contains(PRINT_DOCS_STABLE_OPTION), true);
+        assert_eq!(s.contains(PRINT_DOCS_UNSTABLE_OPTION), true);
+        assert_eq!(s.contains(PRINT_DOCS_PARTIALLY_UNSTABLE_OPTION), true);
     }
 
     #[test]
@@ -541,6 +628,7 @@ normalize_doc_attributes = false
 format_strings = false
 format_macro_matchers = false
 format_macro_bodies = true
+skip_macro_invocations = []
 hex_literal_case = "Preserve"
 empty_item_single_line = true
 struct_lit_single_line = true
@@ -567,7 +655,7 @@ enum_discrim_align_threshold = 0
 match_arm_blocks = true
 match_arm_leading_pipes = "Never"
 force_multiline_blocks = false
-fn_args_layout = "Tall"
+fn_params_layout = "Tall"
 brace_style = "SameLineWhere"
 control_brace_style = "AlwaysSameLine"
 trailing_semicolon = true
@@ -921,4 +1009,45 @@ make_backup = false
             assert_eq!(config.single_line_if_else_max_width(), 100);
         }
     }
+
+    #[cfg(test)]
+    mod partially_unstable_option {
+        use super::mock::{Config, PartiallyUnstableOption};
+        use super::*;
+
+        /// From the command line, we can override with a stable variant.
+        #[test]
+        fn test_override_stable_value() {
+            let mut config = Config::default();
+            config.override_value("partially_unstable_option", "V2");
+            assert_eq!(
+                config.partially_unstable_option(),
+                PartiallyUnstableOption::V2
+            );
+        }
+
+        /// From the command line, we can override with an unstable variant.
+        #[test]
+        fn test_override_unstable_value() {
+            let mut config = Config::default();
+            config.override_value("partially_unstable_option", "V3");
+            assert_eq!(
+                config.partially_unstable_option(),
+                PartiallyUnstableOption::V3
+            );
+        }
+    }
+
+    #[test]
+    fn test_override_skip_macro_invocations() {
+        let mut config = Config::default();
+        config.override_value("skip_macro_invocations", r#"["*", "println"]"#);
+        assert_eq!(
+            config.skip_macro_invocations(),
+            MacroSelectors(vec![
+                MacroSelector::All,
+                MacroSelector::Name(MacroName::new("println".to_owned()))
+            ])
+        );
+    }
 }
diff --git a/src/tools/rustfmt/src/expr.rs b/src/tools/rustfmt/src/expr.rs
index 868ff045ab7..3f0f217f890 100644
--- a/src/tools/rustfmt/src/expr.rs
+++ b/src/tools/rustfmt/src/expr.rs
@@ -29,9 +29,9 @@ use crate::spanned::Spanned;
 use crate::string::{rewrite_string, StringFormat};
 use crate::types::{rewrite_path, PathContext};
 use crate::utils::{
-    colon_spaces, contains_skip, count_newlines, first_line_ends_with, inner_attributes,
-    last_line_extendable, last_line_width, mk_sp, outer_attributes, semicolon_for_expr,
-    unicode_str_width, wrap_str,
+    colon_spaces, contains_skip, count_newlines, filtered_str_fits, first_line_ends_with,
+    inner_attributes, last_line_extendable, last_line_width, mk_sp, outer_attributes,
+    semicolon_for_expr, unicode_str_width, wrap_str,
 };
 use crate::vertical::rewrite_with_alignment;
 use crate::visitor::FmtVisitor;
@@ -400,7 +400,10 @@ pub(crate) fn format_expr(
             }
         }
         ast::ExprKind::Underscore => Some("_".to_owned()),
-        ast::ExprKind::IncludedBytes(..) => unreachable!(),
+        ast::ExprKind::FormatArgs(..) | ast::ExprKind::IncludedBytes(..) => {
+            // These do not occur in the AST because macros aren't expanded.
+            unreachable!()
+        }
         ast::ExprKind::Err => None,
     };
 
@@ -2050,8 +2053,7 @@ fn choose_rhs<R: Rewrite>(
 
             match (orig_rhs, new_rhs) {
                 (Some(ref orig_rhs), Some(ref new_rhs))
-                    if wrap_str(new_rhs.clone(), context.config.max_width(), new_shape)
-                        .is_none() =>
+                    if !filtered_str_fits(&new_rhs, context.config.max_width(), new_shape) =>
                 {
                     Some(format!("{}{}", before_space_str, orig_rhs))
                 }
diff --git a/src/tools/rustfmt/src/imports.rs b/src/tools/rustfmt/src/imports.rs
index d9dc8d004af..339e5cef5af 100644
--- a/src/tools/rustfmt/src/imports.rs
+++ b/src/tools/rustfmt/src/imports.rs
@@ -251,8 +251,8 @@ fn flatten_use_trees(
     use_trees: Vec<UseTree>,
     import_granularity: ImportGranularity,
 ) -> Vec<UseTree> {
-    // Return non-sorted single occurance of the use-trees text string;
-    // order is by first occurance of the use-tree.
+    // Return non-sorted single occurrence of the use-trees text string;
+    // order is by first occurrence of the use-tree.
     use_trees
         .into_iter()
         .flat_map(|tree| tree.flatten(import_granularity))
diff --git a/src/tools/rustfmt/src/items.rs b/src/tools/rustfmt/src/items.rs
index a2a73f0a5fb..25e8a024857 100644
--- a/src/tools/rustfmt/src/items.rs
+++ b/src/tools/rustfmt/src/items.rs
@@ -1084,7 +1084,11 @@ pub(crate) fn format_trait(
             let item_snippet = context.snippet(item.span);
             if let Some(lo) = item_snippet.find('/') {
                 // 1 = `{`
-                let comment_hi = body_lo - BytePos(1);
+                let comment_hi = if generics.params.len() > 0 {
+                    generics.span.lo() - BytePos(1)
+                } else {
+                    body_lo - BytePos(1)
+                };
                 let comment_lo = item.span.lo() + BytePos(lo as u32);
                 if comment_lo < comment_hi {
                     match recover_missing_comment_in_span(
@@ -1241,7 +1245,7 @@ fn format_unit_struct(
 ) -> Option<String> {
     let header_str = format_header(context, p.prefix, p.ident, p.vis, offset);
     let generics_str = if let Some(generics) = p.generics {
-        let hi = context.snippet_provider.span_before(p.span, ";");
+        let hi = context.snippet_provider.span_before_last(p.span, ";");
         format_generics(
             context,
             generics,
@@ -2602,7 +2606,7 @@ fn rewrite_params(
         &param_items,
         context
             .config
-            .fn_args_layout()
+            .fn_params_layout()
             .to_list_tactic(param_items.len()),
         Separator::Comma,
         one_line_budget,
diff --git a/src/tools/rustfmt/src/lists.rs b/src/tools/rustfmt/src/lists.rs
index e8785050782..a878e6cf9b2 100644
--- a/src/tools/rustfmt/src/lists.rs
+++ b/src/tools/rustfmt/src/lists.rs
@@ -297,9 +297,9 @@ where
         } else {
             inner_item.as_ref()
         };
-        let mut item_last_line_width = item_last_line.len() + item_sep_len;
+        let mut item_last_line_width = unicode_str_width(item_last_line) + item_sep_len;
         if item_last_line.starts_with(&**indent_str) {
-            item_last_line_width -= indent_str.len();
+            item_last_line_width -= unicode_str_width(indent_str);
         }
 
         if !item.is_substantial() {
@@ -449,7 +449,7 @@ where
                 } else if starts_with_newline(comment) {
                     false
                 } else {
-                    comment.trim().contains('\n') || comment.trim().len() > width
+                    comment.trim().contains('\n') || unicode_str_width(comment.trim()) > width
                 };
 
                 rewrite_comment(
@@ -465,7 +465,7 @@ where
             if !starts_with_newline(comment) {
                 if formatting.align_comments {
                     let mut comment_alignment =
-                        post_comment_alignment(item_max_width, inner_item.len());
+                        post_comment_alignment(item_max_width, unicode_str_width(inner_item));
                     if first_line_width(&formatted_comment)
                         + last_line_width(&result)
                         + comment_alignment
@@ -475,7 +475,7 @@ where
                         item_max_width = None;
                         formatted_comment = rewrite_post_comment(&mut item_max_width)?;
                         comment_alignment =
-                            post_comment_alignment(item_max_width, inner_item.len());
+                            post_comment_alignment(item_max_width, unicode_str_width(inner_item));
                     }
                     for _ in 0..=comment_alignment {
                         result.push(' ');
@@ -533,7 +533,7 @@ where
     let mut first = true;
     for item in items.clone().into_iter().skip(i) {
         let item = item.as_ref();
-        let inner_item_width = item.inner_as_ref().len();
+        let inner_item_width = unicode_str_width(item.inner_as_ref());
         if !first
             && (item.is_different_group()
                 || item.post_comment.is_none()
@@ -552,8 +552,8 @@ where
     max_width
 }
 
-fn post_comment_alignment(item_max_width: Option<usize>, inner_item_len: usize) -> usize {
-    item_max_width.unwrap_or(0).saturating_sub(inner_item_len)
+fn post_comment_alignment(item_max_width: Option<usize>, inner_item_width: usize) -> usize {
+    item_max_width.unwrap_or(0).saturating_sub(inner_item_width)
 }
 
 pub(crate) struct ListItems<'a, I, F1, F2, F3>
diff --git a/src/tools/rustfmt/src/macros.rs b/src/tools/rustfmt/src/macros.rs
index df949388037..d58f7547fef 100644
--- a/src/tools/rustfmt/src/macros.rs
+++ b/src/tools/rustfmt/src/macros.rs
@@ -35,8 +35,8 @@ use crate::shape::{Indent, Shape};
 use crate::source_map::SpanUtils;
 use crate::spanned::Spanned;
 use crate::utils::{
-    format_visibility, indent_next_line, is_empty_line, mk_sp, remove_trailing_white_spaces,
-    rewrite_ident, trim_left_preserve_layout, wrap_str, NodeIdExt,
+    filtered_str_fits, format_visibility, indent_next_line, is_empty_line, mk_sp,
+    remove_trailing_white_spaces, rewrite_ident, trim_left_preserve_layout, NodeIdExt,
 };
 use crate::visitor::FmtVisitor;
 
@@ -157,7 +157,8 @@ pub(crate) fn rewrite_macro(
 ) -> Option<String> {
     let should_skip = context
         .skip_context
-        .skip_macro(context.snippet(mac.path.span));
+        .macros
+        .skip(context.snippet(mac.path.span));
     if should_skip {
         None
     } else {
@@ -1265,15 +1266,14 @@ impl MacroBranch {
                 }
             }
         };
-        let new_body = wrap_str(
-            new_body_snippet.snippet.to_string(),
-            config.max_width(),
-            shape,
-        )?;
+
+        if !filtered_str_fits(&new_body_snippet.snippet, config.max_width(), shape) {
+            return None;
+        }
 
         // Indent the body since it is in a block.
         let indent_str = body_indent.to_string(&config);
-        let mut new_body = LineClasses::new(new_body.trim_end())
+        let mut new_body = LineClasses::new(new_body_snippet.snippet.trim_end())
             .enumerate()
             .fold(
                 (String::new(), true),
diff --git a/src/tools/rustfmt/src/skip.rs b/src/tools/rustfmt/src/skip.rs
index 032922d421d..68f85b2ade4 100644
--- a/src/tools/rustfmt/src/skip.rs
+++ b/src/tools/rustfmt/src/skip.rs
@@ -2,33 +2,84 @@
 
 use rustc_ast::ast;
 use rustc_ast_pretty::pprust;
+use std::collections::HashSet;
 
-/// Take care of skip name stack. You can update it by attributes slice or
-/// by other context. Query this context to know if you need skip a block.
+/// Track which blocks of code are to be skipped when formatting.
+///
+/// You can update it by:
+///
+/// - attributes slice
+/// - manually feeding values into the underlying contexts
+///
+/// Query this context to know if you need to skip a block.
 #[derive(Default, Clone)]
 pub(crate) struct SkipContext {
-    macros: Vec<String>,
-    attributes: Vec<String>,
+    pub(crate) macros: SkipNameContext,
+    pub(crate) attributes: SkipNameContext,
 }
 
 impl SkipContext {
     pub(crate) fn update_with_attrs(&mut self, attrs: &[ast::Attribute]) {
-        self.macros.append(&mut get_skip_names("macros", attrs));
-        self.attributes
-            .append(&mut get_skip_names("attributes", attrs));
+        self.macros.extend(get_skip_names("macros", attrs));
+        self.attributes.extend(get_skip_names("attributes", attrs));
     }
 
-    pub(crate) fn update(&mut self, mut other: SkipContext) {
-        self.macros.append(&mut other.macros);
-        self.attributes.append(&mut other.attributes);
+    pub(crate) fn update(&mut self, other: SkipContext) {
+        let SkipContext { macros, attributes } = other;
+        self.macros.update(macros);
+        self.attributes.update(attributes);
+    }
+}
+
+/// Track which names to skip.
+///
+/// Query this context with a string to know whether to skip it.
+#[derive(Clone)]
+pub(crate) enum SkipNameContext {
+    All,
+    Values(HashSet<String>),
+}
+
+impl Default for SkipNameContext {
+    fn default() -> Self {
+        Self::Values(Default::default())
+    }
+}
+
+impl Extend<String> for SkipNameContext {
+    fn extend<T: IntoIterator<Item = String>>(&mut self, iter: T) {
+        match self {
+            Self::All => {}
+            Self::Values(values) => values.extend(iter),
+        }
+    }
+}
+
+impl SkipNameContext {
+    pub(crate) fn update(&mut self, other: Self) {
+        match (self, other) {
+            // If we're already skipping everything, nothing more can be added
+            (Self::All, _) => {}
+            // If we want to skip all, set it
+            (this, Self::All) => {
+                *this = Self::All;
+            }
+            // If we have some new values to skip, add them
+            (Self::Values(existing_values), Self::Values(new_values)) => {
+                existing_values.extend(new_values)
+            }
+        }
     }
 
-    pub(crate) fn skip_macro(&self, name: &str) -> bool {
-        self.macros.iter().any(|n| n == name)
+    pub(crate) fn skip(&self, name: &str) -> bool {
+        match self {
+            Self::All => true,
+            Self::Values(values) => values.contains(name),
+        }
     }
 
-    pub(crate) fn skip_attribute(&self, name: &str) -> bool {
-        self.attributes.iter().any(|n| n == name)
+    pub(crate) fn skip_all(&mut self) {
+        *self = Self::All;
     }
 }
 
diff --git a/src/tools/rustfmt/src/test/configuration_snippet.rs b/src/tools/rustfmt/src/test/configuration_snippet.rs
index c8fda7c8556..c70b3c5facd 100644
--- a/src/tools/rustfmt/src/test/configuration_snippet.rs
+++ b/src/tools/rustfmt/src/test/configuration_snippet.rs
@@ -27,8 +27,13 @@ impl ConfigurationSection {
         lazy_static! {
             static ref CONFIG_NAME_REGEX: regex::Regex =
                 regex::Regex::new(r"^## `([^`]+)`").expect("failed creating configuration pattern");
+            // Configuration values, which will be passed to `from_str`:
+            //
+            // - must be prefixed with `####`
+            // - must be wrapped in backticks
+            // - may by wrapped in double quotes (which will be stripped)
             static ref CONFIG_VALUE_REGEX: regex::Regex =
-                regex::Regex::new(r#"^#### `"?([^`"]+)"?`"#)
+                regex::Regex::new(r#"^#### `"?([^`]+?)"?`"#)
                     .expect("failed creating configuration value pattern");
         }
 
diff --git a/src/tools/rustfmt/src/test/mod.rs b/src/tools/rustfmt/src/test/mod.rs
index 6b5bc2b30dd..cfad4a8ed0e 100644
--- a/src/tools/rustfmt/src/test/mod.rs
+++ b/src/tools/rustfmt/src/test/mod.rs
@@ -982,11 +982,7 @@ fn rustfmt() -> PathBuf {
     assert!(
         me.is_file() || me.with_extension("exe").is_file(),
         "{}",
-        if cfg!(release) {
-            "no rustfmt bin, try running `cargo build --release` before testing"
-        } else {
-            "no rustfmt bin, try running `cargo build` before testing"
-        }
+        "no rustfmt bin, try running `cargo build` or `cargo build --release` before testing"
     );
     me
 }
diff --git a/src/tools/rustfmt/src/types.rs b/src/tools/rustfmt/src/types.rs
index c1991e8d2c8..01e2fb6e61e 100644
--- a/src/tools/rustfmt/src/types.rs
+++ b/src/tools/rustfmt/src/types.rs
@@ -941,6 +941,28 @@ fn join_bounds_inner(
         ast::GenericBound::Trait(..) => last_line_extendable(s),
     };
 
+    // Whether a GenericBound item is a PathSegment segment that includes internal array
+    // that contains more than one item
+    let is_item_with_multi_items_array = |item: &ast::GenericBound| match item {
+        ast::GenericBound::Trait(ref poly_trait_ref, ..) => {
+            let segments = &poly_trait_ref.trait_ref.path.segments;
+            if segments.len() > 1 {
+                true
+            } else {
+                if let Some(args_in) = &segments[0].args {
+                    matches!(
+                        args_in.deref(),
+                        ast::GenericArgs::AngleBracketed(bracket_args)
+                            if bracket_args.args.len() > 1
+                    )
+                } else {
+                    false
+                }
+            }
+        }
+        _ => false,
+    };
+
     let result = items.iter().enumerate().try_fold(
         (String::new(), None, false),
         |(strs, prev_trailing_span, prev_extendable), (i, item)| {
@@ -1035,10 +1057,24 @@ fn join_bounds_inner(
         },
     )?;
 
-    if !force_newline
-        && items.len() > 1
-        && (result.0.contains('\n') || result.0.len() > shape.width)
-    {
+    // Whether to retry with a forced newline:
+    //   Only if result is not already multiline and did not exceed line width,
+    //   and either there is more than one item;
+    //       or the single item is of type `Trait`,
+    //          and any of the internal arrays contains more than one item;
+    let retry_with_force_newline = match context.config.version() {
+        Version::One => {
+            !force_newline
+                && items.len() > 1
+                && (result.0.contains('\n') || result.0.len() > shape.width)
+        }
+        Version::Two if force_newline => false,
+        Version::Two if (!result.0.contains('\n') && result.0.len() <= shape.width) => false,
+        Version::Two if items.len() > 1 => true,
+        Version::Two => is_item_with_multi_items_array(&items[0]),
+    };
+
+    if retry_with_force_newline {
         join_bounds_inner(context, shape, items, need_indent, true)
     } else {
         Some(result.0)
diff --git a/src/tools/rustfmt/src/utils.rs b/src/tools/rustfmt/src/utils.rs
index 3e884419f1a..1e89f3ae75f 100644
--- a/src/tools/rustfmt/src/utils.rs
+++ b/src/tools/rustfmt/src/utils.rs
@@ -384,14 +384,15 @@ macro_rules! skip_out_of_file_lines_range_visitor {
 // Wraps String in an Option. Returns Some when the string adheres to the
 // Rewrite constraints defined for the Rewrite trait and None otherwise.
 pub(crate) fn wrap_str(s: String, max_width: usize, shape: Shape) -> Option<String> {
-    if is_valid_str(&filter_normal_code(&s), max_width, shape) {
+    if filtered_str_fits(&s, max_width, shape) {
         Some(s)
     } else {
         None
     }
 }
 
-fn is_valid_str(snippet: &str, max_width: usize, shape: Shape) -> bool {
+pub(crate) fn filtered_str_fits(snippet: &str, max_width: usize, shape: Shape) -> bool {
+    let snippet = &filter_normal_code(snippet);
     if !snippet.is_empty() {
         // First line must fits with `shape.width`.
         if first_line_width(snippet) > shape.width {
@@ -462,6 +463,7 @@ pub(crate) fn first_line_ends_with(s: &str, c: char) -> bool {
 pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr: &str) -> bool {
     match expr.kind {
         ast::ExprKind::MacCall(..)
+        | ast::ExprKind::FormatArgs(..)
         | ast::ExprKind::Call(..)
         | ast::ExprKind::MethodCall(..)
         | ast::ExprKind::Array(..)
diff --git a/src/tools/rustfmt/src/visitor.rs b/src/tools/rustfmt/src/visitor.rs
index 9c3cc7820d2..f4d84d1381f 100644
--- a/src/tools/rustfmt/src/visitor.rs
+++ b/src/tools/rustfmt/src/visitor.rs
@@ -8,7 +8,7 @@ use rustc_span::{symbol, BytePos, Pos, Span};
 use crate::attr::*;
 use crate::comment::{contains_comment, rewrite_comment, CodeCharKind, CommentCodeSlices};
 use crate::config::Version;
-use crate::config::{BraceStyle, Config};
+use crate::config::{BraceStyle, Config, MacroSelector};
 use crate::coverage::transform_missing_snippet;
 use crate::items::{
     format_impl, format_trait, format_trait_alias, is_mod_decl, is_use_item, rewrite_extern_crate,
@@ -770,6 +770,15 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         snippet_provider: &'a SnippetProvider,
         report: FormatReport,
     ) -> FmtVisitor<'a> {
+        let mut skip_context = SkipContext::default();
+        let mut macro_names = Vec::new();
+        for macro_selector in config.skip_macro_invocations().0 {
+            match macro_selector {
+                MacroSelector::Name(name) => macro_names.push(name.to_string()),
+                MacroSelector::All => skip_context.macros.skip_all(),
+            }
+        }
+        skip_context.macros.extend(macro_names);
         FmtVisitor {
             parent_context: None,
             parse_sess: parse_session,
@@ -784,7 +793,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
             is_macro_def: false,
             macro_rewrite_failure: false,
             report,
-            skip_context: Default::default(),
+            skip_context,
         }
     }
 
diff --git a/src/tools/rustfmt/tests/cargo-fmt/main.rs b/src/tools/rustfmt/tests/cargo-fmt/main.rs
index 348876cd264..701c36fadea 100644
--- a/src/tools/rustfmt/tests/cargo-fmt/main.rs
+++ b/src/tools/rustfmt/tests/cargo-fmt/main.rs
@@ -4,6 +4,8 @@ use std::env;
 use std::path::Path;
 use std::process::Command;
 
+use rustfmt_config_proc_macro::rustfmt_only_ci_test;
+
 /// Run the cargo-fmt executable and return its output.
 fn cargo_fmt(args: &[&str]) -> (String, String) {
     let mut bin_dir = env::current_exe().unwrap();
@@ -47,7 +49,7 @@ macro_rules! assert_that {
     };
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn version() {
     assert_that!(&["--version"], starts_with("rustfmt "));
@@ -56,7 +58,7 @@ fn version() {
     assert_that!(&["--", "--version"], starts_with("rustfmt "));
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn print_config() {
     assert_that!(
@@ -65,7 +67,7 @@ fn print_config() {
     );
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn rustfmt_help() {
     assert_that!(&["--", "--help"], contains("Format Rust code"));
@@ -73,7 +75,7 @@ fn rustfmt_help() {
     assert_that!(&["--", "--help=config"], contains("Configuration Options:"));
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn cargo_fmt_out_of_line_test_modules() {
     // See also https://github.com/rust-lang/rustfmt/issues/5119
@@ -96,3 +98,22 @@ fn cargo_fmt_out_of_line_test_modules() {
         assert!(stdout.contains(&format!("Diff in {}", path.display())))
     }
 }
+
+#[rustfmt_only_ci_test]
+#[test]
+fn cargo_fmt_emits_error_on_line_overflow_true() {
+    // See also https://github.com/rust-lang/rustfmt/issues/3164
+    let args = [
+        "--check",
+        "--manifest-path",
+        "tests/cargo-fmt/source/issue_3164/Cargo.toml",
+        "--",
+        "--config",
+        "error_on_line_overflow=true",
+    ];
+
+    let (_stdout, stderr) = cargo_fmt(&args);
+    assert!(stderr.contains(
+        "line formatted, but exceeded maximum width (maximum: 100 (see `max_width` option)"
+    ))
+}
diff --git a/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/Cargo.toml b/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/Cargo.toml
new file mode 100644
index 00000000000..580ef7e6e24
--- /dev/null
+++ b/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "issue_3164"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/src/main.rs b/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/src/main.rs
new file mode 100644
index 00000000000..9330107ac8d
--- /dev/null
+++ b/src/tools/rustfmt/tests/cargo-fmt/source/issue_3164/src/main.rs
@@ -0,0 +1,13 @@
+#[allow(unused_macros)]
+macro_rules! foo {
+    ($id:ident) => {
+        macro_rules! bar {
+            ($id2:tt) => {
+                #[cfg(any(target_feature = $id2, target_feature = $id2, target_feature = $id2, target_feature = $id2, target_feature = $id2))]
+                fn $id() {}
+            };
+        }
+    };
+}
+
+fn main() {}
diff --git a/src/tools/rustfmt/tests/config/small_tabs.toml b/src/tools/rustfmt/tests/config/small_tabs.toml
index c3cfd34317a..4c37100894f 100644
--- a/src/tools/rustfmt/tests/config/small_tabs.toml
+++ b/src/tools/rustfmt/tests/config/small_tabs.toml
@@ -3,7 +3,7 @@ comment_width = 80
 tab_spaces = 2
 newline_style = "Unix"
 brace_style = "SameLineWhere"
-fn_args_layout = "Tall"
+fn_params_layout = "Tall"
 trailing_comma = "Vertical"
 indent_style = "Block"
 reorder_imports = false
diff --git a/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/c/d/explanation.txt b/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/c/d/explanation.txt
index 92c9e302143..254102ebabd 100644
--- a/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/c/d/explanation.txt
+++ b/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/c/d/explanation.txt
@@ -9,7 +9,7 @@ The directory name './lib/c/d/' conflicts with the './lib/c/d.rs' file name.
     * mod g;
 
 Module resolution will fail if we look for './lib/c/d/e.rs' or './lib/c/d/e/mod.rs',
-so we should fall back to looking for './lib/c/e.rs', which correctly finds the modlue, that
+so we should fall back to looking for './lib/c/e.rs', which correctly finds the module, that
 rustfmt should format.
 
 './lib/c/d/f.rs' and './lib/c/d/g/mod.rs' exist at the default submodule paths so we should be able
diff --git a/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/explanation.txt b/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/explanation.txt
index d436a8076cd..90464def8eb 100644
--- a/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/explanation.txt
+++ b/src/tools/rustfmt/tests/mod-resolver/issue-5198/lib/explanation.txt
@@ -9,7 +9,7 @@ The directory name './lib' conflicts with the './lib.rs' file name.
     * mod c;
 
 Module resolution will fail if we look for './lib/a.rs' or './lib/a/mod.rs',
-so we should fall back to looking for './a.rs', which correctly finds the modlue that
+so we should fall back to looking for './a.rs', which correctly finds the module that
 rustfmt should format.
 
 './lib/b.rs' and './lib/c/mod.rs' exist at the default submodule paths so we should be able
diff --git a/src/tools/rustfmt/tests/rustfmt/main.rs b/src/tools/rustfmt/tests/rustfmt/main.rs
index 4c6d52726f3..7ff301e8019 100644
--- a/src/tools/rustfmt/tests/rustfmt/main.rs
+++ b/src/tools/rustfmt/tests/rustfmt/main.rs
@@ -5,6 +5,8 @@ use std::fs::remove_file;
 use std::path::Path;
 use std::process::Command;
 
+use rustfmt_config_proc_macro::rustfmt_only_ci_test;
+
 /// Run the rustfmt executable and return its output.
 fn rustfmt(args: &[&str]) -> (String, String) {
     let mut bin_dir = env::current_exe().unwrap();
@@ -47,7 +49,7 @@ macro_rules! assert_that {
     };
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn print_config() {
     assert_that!(
@@ -76,7 +78,7 @@ fn print_config() {
     remove_file("minimal-config").unwrap();
 }
 
-#[ignore]
+#[rustfmt_only_ci_test]
 #[test]
 fn inline_config() {
     // single invocation
@@ -157,3 +159,18 @@ fn mod_resolution_error_path_attribute_does_not_exist() {
     // The path attribute points to a file that does not exist
     assert!(stderr.contains("does_not_exist.rs does not exist"));
 }
+
+#[test]
+fn rustfmt_emits_error_on_line_overflow_true() {
+    // See also https://github.com/rust-lang/rustfmt/issues/3164
+    let args = [
+        "--config",
+        "error_on_line_overflow=true",
+        "tests/cargo-fmt/source/issue_3164/src/main.rs",
+    ];
+
+    let (_stdout, stderr) = rustfmt(&args);
+    assert!(stderr.contains(
+        "line formatted, but exceeded maximum width (maximum: 100 (see `max_width` option)"
+    ))
+}
diff --git a/src/tools/rustfmt/tests/source/cfg_if/detect/arch/x86.rs b/src/tools/rustfmt/tests/source/cfg_if/detect/arch/x86.rs
index d26f4ee894f..131cbb855f1 100644
--- a/src/tools/rustfmt/tests/source/cfg_if/detect/arch/x86.rs
+++ b/src/tools/rustfmt/tests/source/cfg_if/detect/arch/x86.rs
@@ -329,7 +329,7 @@ pub enum Feature {
     tbm,
     /// POPCNT (Population Count)
     popcnt,
-    /// FXSR (Floating-point context fast save and restor)
+    /// FXSR (Floating-point context fast save and restore)
     fxsr,
     /// XSAVE (Save Processor Extended States)
     xsave,
diff --git a/src/tools/rustfmt/tests/source/comments_unicode.rs b/src/tools/rustfmt/tests/source/comments_unicode.rs
new file mode 100644
index 00000000000..e65a245ba93
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/comments_unicode.rs
@@ -0,0 +1,140 @@
+impl Default for WhitespaceCharacters {
+    fn default() -> Self {
+        Self {
+            space: '·',    // U+00B7
+            nbsp: '⍽',    // U+237D
+            tab: '→',     // U+2192
+            newline: '⏎', // U+23CE
+        }
+    }
+}
+
+const RAINBOWS: &[&str] = &[
+    "rаinЬοѡ",    // hue: 0
+    "raіnЬοw",     // hue: 2
+    "rаіɴЬow",    // hue: 2
+    "raіɴЬoѡ",    // hue: 8
+    "ʀainЬow",      // hue: 8
+    "ʀaіɴboѡ",    // hue: 8
+    "ʀаіnbοw",    // hue: 11
+    "rainЬoѡ",      // hue: 14
+    "raіɴbow",      // hue: 14
+    "rаiɴЬow",     // hue: 20
+    "raіnЬow",      // hue: 26
+    "ʀaiɴbοw",     // hue: 32
+    "raіɴboѡ",     // hue: 35
+    "rаiɴbow",      // hue: 35
+    "rаіnbοw",     // hue: 38
+    "rаinЬow",      // hue: 47
+    "ʀaіnboѡ",     // hue: 47
+    "ʀaіnЬoѡ",    // hue: 47
+    "ʀаіɴbοw",   // hue: 53
+    "ʀaіnЬοѡ",   // hue: 57
+    "raiɴЬoѡ",     // hue: 68
+    "ʀainbοѡ",     // hue: 68
+    "ʀаinboѡ",     // hue: 68
+    "ʀаiɴbοw",    // hue: 68
+    "ʀаіnbow",     // hue: 68
+    "rаіnЬοѡ",   // hue: 69
+    "ʀainЬοw",     // hue: 71
+    "raiɴbow",       // hue: 73
+    "raіnЬoѡ",     // hue: 74
+    "rаіɴbοw",    // hue: 77
+    "raіnЬοѡ",    // hue: 81
+    "raiɴЬow",      // hue: 83
+    "ʀainbοw",      // hue: 83
+    "ʀаinbow",      // hue: 83
+    "ʀаiɴbοѡ",   // hue: 83
+    "ʀаіnboѡ",    // hue: 83
+    "ʀаіɴЬοѡ", // hue: 84
+    "rainЬow",       // hue: 85
+    "ʀаiɴЬοw",   // hue: 86
+    "ʀаіnbοѡ",   // hue: 89
+    "ʀаіnЬοw",   // hue: 92
+    "rаiɴbοw",     // hue: 95
+    "ʀаіɴbοѡ",  // hue: 98
+    "ʀаiɴЬοѡ",  // hue: 99
+    "raіnbοw",      // hue: 101
+    "ʀаіɴЬοw",  // hue: 101
+    "ʀaiɴboѡ",     // hue: 104
+    "ʀаinbοѡ",    // hue: 104
+    "rаiɴbοѡ",    // hue: 107
+    "ʀаinЬοw",    // hue: 107
+    "rаiɴЬοw",    // hue: 110
+    "rаіnboѡ",     // hue: 110
+    "rаіnbοѡ",    // hue: 113
+    "ʀainЬοѡ",    // hue: 114
+    "rаіnЬοw",    // hue: 116
+    "ʀaіɴЬow",    // hue: 116
+    "rаinbοw",      // hue: 122
+    "ʀаіɴboѡ",   // hue: 125
+    "rаinbοѡ",     // hue: 131
+    "rainbow",        // hue: 134
+    "rаinЬοw",     // hue: 134
+    "ʀаiɴboѡ",    // hue: 140
+    "rainЬοѡ",     // hue: 141
+    "raіɴЬow",     // hue: 143
+    "ʀainЬoѡ",     // hue: 143
+    "ʀaіɴbow",     // hue: 143
+    "ʀainbow",       // hue: 148
+    "rаіɴboѡ",    // hue: 149
+    "ʀainboѡ",      // hue: 155
+    "ʀaіnbow",      // hue: 155
+    "ʀaіnЬow",     // hue: 155
+    "raiɴbοw",      // hue: 158
+    "ʀаiɴЬoѡ",   // hue: 158
+    "rainbοw",       // hue: 160
+    "rаinbow",       // hue: 160
+    "ʀaіɴbοѡ",   // hue: 164
+    "ʀаiɴbow",     // hue: 164
+    "ʀаіnЬoѡ",   // hue: 164
+    "ʀaiɴЬοѡ",   // hue: 165
+    "rаiɴboѡ",     // hue: 167
+    "ʀaіɴЬοw",   // hue: 167
+    "ʀaіɴЬοѡ",  // hue: 171
+    "raіnboѡ",      // hue: 173
+    "ʀаіɴЬoѡ",  // hue: 173
+    "rаіɴbοѡ",   // hue: 176
+    "ʀаinЬow",     // hue: 176
+    "rаiɴЬοѡ",   // hue: 177
+    "rаіɴЬοw",   // hue: 179
+    "ʀаinЬoѡ",    // hue: 179
+    "ʀаіɴbow",    // hue: 179
+    "rаiɴЬoѡ",    // hue: 182
+    "raіɴbοѡ",    // hue: 188
+    "rаіnЬoѡ",    // hue: 188
+    "raiɴЬοѡ",    // hue: 189
+    "raіɴЬοw",    // hue: 191
+    "ʀaіɴbοw",    // hue: 191
+    "ʀаіnЬow",    // hue: 191
+    "rainbοѡ",      // hue: 194
+    "rаinboѡ",      // hue: 194
+    "rаіnbow",      // hue: 194
+    "rainЬοw",      // hue: 197
+    "rаinЬoѡ",     // hue: 206
+    "rаіɴbow",     // hue: 206
+    "rаіɴЬοѡ",  // hue: 210
+    "ʀaiɴЬow",     // hue: 212
+    "raіɴbοw",     // hue: 218
+    "rаіnЬow",     // hue: 218
+    "ʀaiɴbοѡ",    // hue: 221
+    "ʀaiɴЬοw",    // hue: 224
+    "ʀaіnbοѡ",    // hue: 227
+    "raiɴboѡ",      // hue: 230
+    "ʀaіnbοw",     // hue: 230
+    "ʀaіnЬοw",    // hue: 230
+    "ʀаinЬοѡ",   // hue: 231
+    "rainboѡ",       // hue: 232
+    "raіnbow",       // hue: 232
+    "ʀаіɴЬow",   // hue: 233
+    "ʀaіɴЬoѡ",   // hue: 239
+    "ʀаіnЬοѡ",  // hue: 246
+    "raiɴbοѡ",     // hue: 248
+    "ʀаiɴЬow",    // hue: 248
+    "raіɴЬοѡ",   // hue: 249
+    "raiɴЬοw",     // hue: 251
+    "rаіɴЬoѡ",   // hue: 251
+    "ʀaiɴbow",      // hue: 251
+    "ʀаinbοw",     // hue: 251
+    "raіnbοѡ",     // hue: 254
+];
diff --git a/src/tools/rustfmt/tests/source/configs/fn_args_layout/compressed.rs b/src/tools/rustfmt/tests/source/configs/fn_params_layout/compressed.rs
index 66a371c259f..eb573d3121f 100644
--- a/src/tools/rustfmt/tests/source/configs/fn_args_layout/compressed.rs
+++ b/src/tools/rustfmt/tests/source/configs/fn_params_layout/compressed.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Compressed
+// rustfmt-fn_params_layout: Compressed
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/source/configs/fn_args_layout/tall.rs b/src/tools/rustfmt/tests/source/configs/fn_params_layout/tall.rs
index f11e86fd313..4be34f0fe4a 100644
--- a/src/tools/rustfmt/tests/source/configs/fn_args_layout/tall.rs
+++ b/src/tools/rustfmt/tests/source/configs/fn_params_layout/tall.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Tall
+// rustfmt-fn_params_layout: Tall
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/source/configs/fn_args_layout/vertical.rs b/src/tools/rustfmt/tests/source/configs/fn_params_layout/vertical.rs
index a23cc025225..674968023f9 100644
--- a/src/tools/rustfmt/tests/source/configs/fn_args_layout/vertical.rs
+++ b/src/tools/rustfmt/tests/source/configs/fn_params_layout/vertical.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/source/enum.rs b/src/tools/rustfmt/tests/source/enum.rs
index 0ed9651abe7..a7b9616929c 100644
--- a/src/tools/rustfmt/tests/source/enum.rs
+++ b/src/tools/rustfmt/tests/source/enum.rs
@@ -36,7 +36,7 @@ enum StructLikeVariants {
     Normal(u32, String, ),
     StructLike { x: i32, // Test comment
         // Pre-comment
-        #[Attr50] y: SomeType, // Aanother Comment
+        #[Attr50] y: SomeType, // Another Comment
     }, SL { a: A }
 }
 
diff --git a/src/tools/rustfmt/tests/source/fn-custom-7.rs b/src/tools/rustfmt/tests/source/fn-custom-7.rs
index d5330196bf7..3ecd8701727 100644
--- a/src/tools/rustfmt/tests/source/fn-custom-7.rs
+++ b/src/tools/rustfmt/tests/source/fn-custom-7.rs
@@ -1,5 +1,5 @@
 // rustfmt-normalize_comments: true
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 // rustfmt-brace_style: AlwaysNextLine
 
 // Case with only one variable.
diff --git a/src/tools/rustfmt/tests/source/fn-custom.rs b/src/tools/rustfmt/tests/source/fn-custom.rs
index 77ced4c5e0e..64ef0ecfaae 100644
--- a/src/tools/rustfmt/tests/source/fn-custom.rs
+++ b/src/tools/rustfmt/tests/source/fn-custom.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Compressed
+// rustfmt-fn_params_layout: Compressed
 // Test some of the ways function signatures can be customised.
 
 // Test compressed layout of args.
diff --git a/src/tools/rustfmt/tests/source/fn_args_layout-vertical.rs b/src/tools/rustfmt/tests/source/fn_args_layout-vertical.rs
index 759bc83d015..fd6e3f0442e 100644
--- a/src/tools/rustfmt/tests/source/fn_args_layout-vertical.rs
+++ b/src/tools/rustfmt/tests/source/fn_args_layout-vertical.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 
 // Empty list should stay on one line.
 fn do_bar(
diff --git a/src/tools/rustfmt/tests/source/issue-3987/format_macro_bodies_true.rs b/src/tools/rustfmt/tests/source/issue-3987/format_macro_bodies_true.rs
new file mode 100644
index 00000000000..9af114fbe57
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue-3987/format_macro_bodies_true.rs
@@ -0,0 +1,26 @@
+// rustfmt-format_macro_bodies: true
+
+// with comments
+macro_rules! macros {
+    () => {{
+        Struct {
+            field: (
+                42 + //comment 1
+                42
+                //comment 2
+            ),
+        };
+    }};
+}
+
+// without comments
+macro_rules! macros {
+    () => {{
+        Struct {
+            field: (
+                42 +
+                42
+            ),
+        };
+    }};
+}
diff --git a/src/tools/rustfmt/tests/source/issue-4643.rs b/src/tools/rustfmt/tests/source/issue-4643.rs
new file mode 100644
index 00000000000..382072d9004
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue-4643.rs
@@ -0,0 +1,23 @@
+// output doesn't get corrupted when using comments within generic type parameters of a trait
+
+pub trait Something<
+    A,
+    // some comment
+    B,
+    C
+> {
+    fn a(&self, x: A) -> i32;
+    fn b(&self, x: B) -> i32;
+    fn c(&self, x: C) -> i32;
+}
+
+pub trait SomethingElse<
+    A,
+    /* some comment */
+    B,
+    C
+> {
+    fn a(&self, x: A) -> i32;
+    fn b(&self, x: B) -> i32;
+    fn c(&self, x: C) -> i32;
+}
diff --git a/src/tools/rustfmt/tests/source/issue-4689/one.rs b/src/tools/rustfmt/tests/source/issue-4689/one.rs
new file mode 100644
index 00000000000..d048eb10fb1
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue-4689/one.rs
@@ -0,0 +1,149 @@
+// rustfmt-version: One
+
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write1 + fmt::Write2
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer1<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + Printer2<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+>,
+> {
+}
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+> + fmt::Write1
++ fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+)
+{
+}
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+) + fmt::Write
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+mut entries: entryyyyyyyy,
+) -> (
+impl Fn(
+AlphabeticalTraversal,
+Seconddddddddddddddddddddddddddddddddddd
+) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
++ Sendddddddddddddddddddddddddddddddddddddddddddd
+) {
+}
+    
+pub trait SomeTrait:
+Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+for<'b> &'b Self: Send
++ Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
diff --git a/src/tools/rustfmt/tests/source/issue-4689/two.rs b/src/tools/rustfmt/tests/source/issue-4689/two.rs
new file mode 100644
index 00000000000..ea7feda825d
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue-4689/two.rs
@@ -0,0 +1,149 @@
+// rustfmt-version: Two
+
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write1 + fmt::Write2
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer1<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + Printer2<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+>,
+> {
+}
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+> + fmt::Write1
++ fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+)
+{
+}
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+) + fmt::Write
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+mut entries: entryyyyyyyy,
+) -> (
+impl Fn(
+AlphabeticalTraversal,
+Seconddddddddddddddddddddddddddddddddddd
+) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
++ Sendddddddddddddddddddddddddddddddddddddddddddd
+) {
+}
+    
+pub trait SomeTrait:
+Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+for<'b> &'b Self: Send
++ Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
diff --git a/src/tools/rustfmt/tests/source/issue_1306.rs b/src/tools/rustfmt/tests/source/issue_1306.rs
new file mode 100644
index 00000000000..03b78e34108
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue_1306.rs
@@ -0,0 +1,29 @@
+// rustfmt-max_width: 160
+// rustfmt-fn_call_width: 96
+// rustfmt-fn_args_layout: Compressed
+// rustfmt-trailing_comma: Always
+// rustfmt-wrap_comments: true
+
+fn foo() {
+    for elem in try!(gen_epub_book::ops::parse_descriptor_file(&mut try!(File::open(&opts.source_file.1).map_err(|_| {
+        gen_epub_book::Error::Io {
+            desc: "input file",
+            op: "open",
+            more: None,
+        }
+    })),
+                                                               "input file")) {
+        println!("{}", elem);
+    }
+}
+
+fn write_content() {
+    io::copy(try!(File::open(in_f).map_err(|_| {
+        Error::Io {
+            desc: "Content",
+            op: "open",
+            more: None,
+        }
+    })),
+             w);
+}
diff --git a/src/tools/rustfmt/tests/source/issue_3245.rs b/src/tools/rustfmt/tests/source/issue_3245.rs
new file mode 100644
index 00000000000..0279246ed6a
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue_3245.rs
@@ -0,0 +1,4 @@
+fn main() {
+    let x = 1;
+    ;let y = 3;
+}
diff --git a/src/tools/rustfmt/tests/source/issue_3561.rs b/src/tools/rustfmt/tests/source/issue_3561.rs
new file mode 100644
index 00000000000..8f6cd8f9fbc
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/issue_3561.rs
@@ -0,0 +1,6 @@
+fn main() {;7
+}
+
+fn main() {
+    ;7
+}
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/all.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/all.rs
new file mode 100644
index 00000000000..d0437ee10fd
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/all.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["*"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should skip this invocation
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/all_and_name.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/all_and_name.rs
new file mode 100644
index 00000000000..1f6722344fe
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/all_and_name.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["*","items"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should also skip this invocation, as the wildcard covers it
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/empty.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/empty.rs
new file mode 100644
index 00000000000..f3dd89dc4db
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/empty.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: []
+
+// Should not skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should not skip this invocation
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/name.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/name.rs
new file mode 100644
index 00000000000..7fa5d3a6f71
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/name.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["items"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should not skip this invocation
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/name_unknown.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/name_unknown.rs
new file mode 100644
index 00000000000..d5669532524
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/name_unknown.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["unknown"]
+
+// Should not skip this invocation
+items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/names.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/names.rs
new file mode 100644
index 00000000000..a920381a455
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/names.rs
@@ -0,0 +1,16 @@
+// rustfmt-skip_macro_invocations: ["foo","bar"]
+
+// Should skip this invocation
+foo!(
+        const _: u8 = 0;
+);
+
+// Should skip this invocation
+bar!(
+        const _: u8 = 0;
+);
+
+// Should not skip this invocation
+baz!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_invocation_mismatch.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_invocation_mismatch.rs
new file mode 100644
index 00000000000..61296869a50
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_invocation_mismatch.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["items"]
+
+// Should not skip this invocation
+self::items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_match.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_match.rs
new file mode 100644
index 00000000000..9398918a9e1
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_match.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["self::items"]
+
+// Should skip this invocation
+self::items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_name_mismatch.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_name_mismatch.rs
new file mode 100644
index 00000000000..4e3eb542dbe
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/path_qualified_name_mismatch.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["self::items"]
+
+// Should not skip this invocation
+items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/skip_macro_invocations/use_alias_examples.rs b/src/tools/rustfmt/tests/source/skip_macro_invocations/use_alias_examples.rs
new file mode 100644
index 00000000000..43cb8015de5
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/skip_macro_invocations/use_alias_examples.rs
@@ -0,0 +1,32 @@
+// rustfmt-skip_macro_invocations: ["aaa","ccc"]
+
+// These tests demonstrate a realistic use case with use aliases.
+// The use statements should not impact functionality in any way.
+
+use crate::{aaa, bbb, ddd};
+
+// No use alias, invocation in list
+// Should skip this invocation
+aaa!(
+        const _: u8 = 0;
+);
+
+// Use alias, invocation in list
+// Should skip this invocation
+use crate::bbb as ccc;
+ccc!(
+        const _: u8 = 0;
+);
+
+// Use alias, invocation not in list
+// Should not skip this invocation
+use crate::ddd as eee;
+eee!(
+        const _: u8 = 0;
+);
+
+// No use alias, invocation not in list
+// Should not skip this invocation
+fff!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/source/tuple.rs b/src/tools/rustfmt/tests/source/tuple.rs
index 9a0f979fbca..5189a7454f3 100644
--- a/src/tools/rustfmt/tests/source/tuple.rs
+++ b/src/tools/rustfmt/tests/source/tuple.rs
@@ -1,4 +1,4 @@
-// Test tuple litterals
+// Test tuple literals
 
 fn foo() {
     let a = (a, a, a, a, a);
diff --git a/src/tools/rustfmt/tests/source/wrap_comments_should_not_imply_format_doc_comments.rs b/src/tools/rustfmt/tests/source/wrap_comments_should_not_imply_format_doc_comments.rs
index 78b3ce146f2..56064e4a4cc 100644
--- a/src/tools/rustfmt/tests/source/wrap_comments_should_not_imply_format_doc_comments.rs
+++ b/src/tools/rustfmt/tests/source/wrap_comments_should_not_imply_format_doc_comments.rs
@@ -11,6 +11,6 @@
 ///
 fn foo() {}
 
-/// A long commment for wrapping
+/// A long comment for wrapping
 /// This is a long long long long long long long long long long long long long long long long long long long long sentence.
 fn bar() {}
diff --git a/src/tools/rustfmt/tests/target/cfg_if/detect/arch/x86.rs b/src/tools/rustfmt/tests/target/cfg_if/detect/arch/x86.rs
index 02d5eed1c29..47210cae2aa 100644
--- a/src/tools/rustfmt/tests/target/cfg_if/detect/arch/x86.rs
+++ b/src/tools/rustfmt/tests/target/cfg_if/detect/arch/x86.rs
@@ -314,7 +314,7 @@ pub enum Feature {
     tbm,
     /// POPCNT (Population Count)
     popcnt,
-    /// FXSR (Floating-point context fast save and restor)
+    /// FXSR (Floating-point context fast save and restore)
     fxsr,
     /// XSAVE (Save Processor Extended States)
     xsave,
diff --git a/src/tools/rustfmt/tests/target/comments_unicode.rs b/src/tools/rustfmt/tests/target/comments_unicode.rs
new file mode 100644
index 00000000000..3e1b6b0a28f
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/comments_unicode.rs
@@ -0,0 +1,140 @@
+impl Default for WhitespaceCharacters {
+    fn default() -> Self {
+        Self {
+            space: '·',   // U+00B7
+            nbsp: '⍽',    // U+237D
+            tab: '→',     // U+2192
+            newline: '⏎', // U+23CE
+        }
+    }
+}
+
+const RAINBOWS: &[&str] = &[
+    "rаinЬοѡ", // hue: 0
+    "raіnЬοw", // hue: 2
+    "rаіɴЬow", // hue: 2
+    "raіɴЬoѡ", // hue: 8
+    "ʀainЬow", // hue: 8
+    "ʀaіɴboѡ", // hue: 8
+    "ʀаіnbοw", // hue: 11
+    "rainЬoѡ", // hue: 14
+    "raіɴbow", // hue: 14
+    "rаiɴЬow", // hue: 20
+    "raіnЬow", // hue: 26
+    "ʀaiɴbοw", // hue: 32
+    "raіɴboѡ", // hue: 35
+    "rаiɴbow", // hue: 35
+    "rаіnbοw", // hue: 38
+    "rаinЬow", // hue: 47
+    "ʀaіnboѡ", // hue: 47
+    "ʀaіnЬoѡ", // hue: 47
+    "ʀаіɴbοw", // hue: 53
+    "ʀaіnЬοѡ", // hue: 57
+    "raiɴЬoѡ", // hue: 68
+    "ʀainbοѡ", // hue: 68
+    "ʀаinboѡ", // hue: 68
+    "ʀаiɴbοw", // hue: 68
+    "ʀаіnbow", // hue: 68
+    "rаіnЬοѡ", // hue: 69
+    "ʀainЬοw", // hue: 71
+    "raiɴbow", // hue: 73
+    "raіnЬoѡ", // hue: 74
+    "rаіɴbοw", // hue: 77
+    "raіnЬοѡ", // hue: 81
+    "raiɴЬow", // hue: 83
+    "ʀainbοw", // hue: 83
+    "ʀаinbow", // hue: 83
+    "ʀаiɴbοѡ", // hue: 83
+    "ʀаіnboѡ", // hue: 83
+    "ʀаіɴЬοѡ", // hue: 84
+    "rainЬow", // hue: 85
+    "ʀаiɴЬοw", // hue: 86
+    "ʀаіnbοѡ", // hue: 89
+    "ʀаіnЬοw", // hue: 92
+    "rаiɴbοw", // hue: 95
+    "ʀаіɴbοѡ", // hue: 98
+    "ʀаiɴЬοѡ", // hue: 99
+    "raіnbοw", // hue: 101
+    "ʀаіɴЬοw", // hue: 101
+    "ʀaiɴboѡ", // hue: 104
+    "ʀаinbοѡ", // hue: 104
+    "rаiɴbοѡ", // hue: 107
+    "ʀаinЬοw", // hue: 107
+    "rаiɴЬοw", // hue: 110
+    "rаіnboѡ", // hue: 110
+    "rаіnbοѡ", // hue: 113
+    "ʀainЬοѡ", // hue: 114
+    "rаіnЬοw", // hue: 116
+    "ʀaіɴЬow", // hue: 116
+    "rаinbοw", // hue: 122
+    "ʀаіɴboѡ", // hue: 125
+    "rаinbοѡ", // hue: 131
+    "rainbow", // hue: 134
+    "rаinЬοw", // hue: 134
+    "ʀаiɴboѡ", // hue: 140
+    "rainЬοѡ", // hue: 141
+    "raіɴЬow", // hue: 143
+    "ʀainЬoѡ", // hue: 143
+    "ʀaіɴbow", // hue: 143
+    "ʀainbow", // hue: 148
+    "rаіɴboѡ", // hue: 149
+    "ʀainboѡ", // hue: 155
+    "ʀaіnbow", // hue: 155
+    "ʀaіnЬow", // hue: 155
+    "raiɴbοw", // hue: 158
+    "ʀаiɴЬoѡ", // hue: 158
+    "rainbοw", // hue: 160
+    "rаinbow", // hue: 160
+    "ʀaіɴbοѡ", // hue: 164
+    "ʀаiɴbow", // hue: 164
+    "ʀаіnЬoѡ", // hue: 164
+    "ʀaiɴЬοѡ", // hue: 165
+    "rаiɴboѡ", // hue: 167
+    "ʀaіɴЬοw", // hue: 167
+    "ʀaіɴЬοѡ", // hue: 171
+    "raіnboѡ", // hue: 173
+    "ʀаіɴЬoѡ", // hue: 173
+    "rаіɴbοѡ", // hue: 176
+    "ʀаinЬow", // hue: 176
+    "rаiɴЬοѡ", // hue: 177
+    "rаіɴЬοw", // hue: 179
+    "ʀаinЬoѡ", // hue: 179
+    "ʀаіɴbow", // hue: 179
+    "rаiɴЬoѡ", // hue: 182
+    "raіɴbοѡ", // hue: 188
+    "rаіnЬoѡ", // hue: 188
+    "raiɴЬοѡ", // hue: 189
+    "raіɴЬοw", // hue: 191
+    "ʀaіɴbοw", // hue: 191
+    "ʀаіnЬow", // hue: 191
+    "rainbοѡ", // hue: 194
+    "rаinboѡ", // hue: 194
+    "rаіnbow", // hue: 194
+    "rainЬοw", // hue: 197
+    "rаinЬoѡ", // hue: 206
+    "rаіɴbow", // hue: 206
+    "rаіɴЬοѡ", // hue: 210
+    "ʀaiɴЬow", // hue: 212
+    "raіɴbοw", // hue: 218
+    "rаіnЬow", // hue: 218
+    "ʀaiɴbοѡ", // hue: 221
+    "ʀaiɴЬοw", // hue: 224
+    "ʀaіnbοѡ", // hue: 227
+    "raiɴboѡ", // hue: 230
+    "ʀaіnbοw", // hue: 230
+    "ʀaіnЬοw", // hue: 230
+    "ʀаinЬοѡ", // hue: 231
+    "rainboѡ", // hue: 232
+    "raіnbow", // hue: 232
+    "ʀаіɴЬow", // hue: 233
+    "ʀaіɴЬoѡ", // hue: 239
+    "ʀаіnЬοѡ", // hue: 246
+    "raiɴbοѡ", // hue: 248
+    "ʀаiɴЬow", // hue: 248
+    "raіɴЬοѡ", // hue: 249
+    "raiɴЬοw", // hue: 251
+    "rаіɴЬoѡ", // hue: 251
+    "ʀaiɴbow", // hue: 251
+    "ʀаinbοw", // hue: 251
+    "raіnbοѡ", // hue: 254
+];
diff --git a/src/tools/rustfmt/tests/target/configs/fn_args_layout/compressed.rs b/src/tools/rustfmt/tests/target/configs/fn_params_layout/compressed.rs
index f189446e25d..ff32f0f1d58 100644
--- a/src/tools/rustfmt/tests/target/configs/fn_args_layout/compressed.rs
+++ b/src/tools/rustfmt/tests/target/configs/fn_params_layout/compressed.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Compressed
+// rustfmt-fn_params_layout: Compressed
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/target/configs/fn_args_layout/tall.rs b/src/tools/rustfmt/tests/target/configs/fn_params_layout/tall.rs
index 20f308973ac..25a86799af0 100644
--- a/src/tools/rustfmt/tests/target/configs/fn_args_layout/tall.rs
+++ b/src/tools/rustfmt/tests/target/configs/fn_params_layout/tall.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Tall
+// rustfmt-fn_params_layout: Tall
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/target/configs/fn_args_layout/vertical.rs b/src/tools/rustfmt/tests/target/configs/fn_params_layout/vertical.rs
index 6c695a75df9..7a0e42415f3 100644
--- a/src/tools/rustfmt/tests/target/configs/fn_args_layout/vertical.rs
+++ b/src/tools/rustfmt/tests/target/configs/fn_params_layout/vertical.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 // Function arguments density
 
 trait Lorem {
diff --git a/src/tools/rustfmt/tests/target/enum.rs b/src/tools/rustfmt/tests/target/enum.rs
index 9a25126b44e..70fc8ab376c 100644
--- a/src/tools/rustfmt/tests/target/enum.rs
+++ b/src/tools/rustfmt/tests/target/enum.rs
@@ -43,7 +43,7 @@ enum StructLikeVariants {
         x: i32, // Test comment
         // Pre-comment
         #[Attr50]
-        y: SomeType, // Aanother Comment
+        y: SomeType, // Another Comment
     },
     SL {
         a: A,
diff --git a/src/tools/rustfmt/tests/target/fn-custom-7.rs b/src/tools/rustfmt/tests/target/fn-custom-7.rs
index 2c20ac5a752..f6a1a90c3fc 100644
--- a/src/tools/rustfmt/tests/target/fn-custom-7.rs
+++ b/src/tools/rustfmt/tests/target/fn-custom-7.rs
@@ -1,5 +1,5 @@
 // rustfmt-normalize_comments: true
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 // rustfmt-brace_style: AlwaysNextLine
 
 // Case with only one variable.
diff --git a/src/tools/rustfmt/tests/target/fn-custom.rs b/src/tools/rustfmt/tests/target/fn-custom.rs
index 2eb2a973d24..506d9de3437 100644
--- a/src/tools/rustfmt/tests/target/fn-custom.rs
+++ b/src/tools/rustfmt/tests/target/fn-custom.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Compressed
+// rustfmt-fn_params_layout: Compressed
 // Test some of the ways function signatures can be customised.
 
 // Test compressed layout of args.
diff --git a/src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs b/src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs
index da0ac981d87..bfeca15c967 100644
--- a/src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs
+++ b/src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs
@@ -1,4 +1,4 @@
-// rustfmt-fn_args_layout: Vertical
+// rustfmt-fn_params_layout: Vertical
 
 // Empty list should stay on one line.
 fn do_bar() -> u8 {
diff --git a/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_false.rs b/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_false.rs
new file mode 100644
index 00000000000..2038ed7f1d0
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_false.rs
@@ -0,0 +1,6 @@
+// rustfmt-format_macro_matchers: false
+
+macro_rules! foo {
+    ($a:ident : $b:ty) => {};
+    ($a:ident $b:ident $c:ident) => {};
+}
diff --git a/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_true.rs b/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_true.rs
new file mode 100644
index 00000000000..01d939add4d
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-2534/format_macro_matchers_true.rs
@@ -0,0 +1,6 @@
+// rustfmt-format_macro_matchers: true
+
+macro_rules! foo {
+    ($a:ident : $b:ty) => {};
+    ($a:ident $b:ident $c:ident) => {};
+}
diff --git a/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_false.rs b/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_false.rs
new file mode 100644
index 00000000000..1352b762e45
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_false.rs
@@ -0,0 +1,26 @@
+// rustfmt-format_macro_bodies: false
+
+// with comments
+macro_rules! macros {
+    () => {{
+        Struct {
+            field: (
+                42 + //comment 1
+                42
+                //comment 2
+            ),
+        };
+    }};
+}
+
+// without comments
+macro_rules! macros {
+    () => {{
+        Struct {
+            field: (
+                42 +
+                42
+            ),
+        };
+    }};
+}
diff --git a/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_true.rs b/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_true.rs
new file mode 100644
index 00000000000..88d57159c85
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-3987/format_macro_bodies_true.rs
@@ -0,0 +1,21 @@
+// rustfmt-format_macro_bodies: true
+
+// with comments
+macro_rules! macros {
+    () => {{
+        Struct {
+            field: (
+                42 + //comment 1
+                42
+                //comment 2
+            ),
+        };
+    }};
+}
+
+// without comments
+macro_rules! macros {
+    () => {{
+        Struct { field: (42 + 42) };
+    }};
+}
diff --git a/src/tools/rustfmt/tests/target/issue-4643.rs b/src/tools/rustfmt/tests/target/issue-4643.rs
new file mode 100644
index 00000000000..ef99e4db382
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-4643.rs
@@ -0,0 +1,19 @@
+// output doesn't get corrupted when using comments within generic type parameters of a trait
+
+pub trait Something<
+    A,
+    // some comment
+    B,
+    C,
+>
+{
+    fn a(&self, x: A) -> i32;
+    fn b(&self, x: B) -> i32;
+    fn c(&self, x: C) -> i32;
+}
+
+pub trait SomethingElse<A, /* some comment */ B, C> {
+    fn a(&self, x: A) -> i32;
+    fn b(&self, x: B) -> i32;
+    fn c(&self, x: C) -> i32;
+}
diff --git a/src/tools/rustfmt/tests/target/issue-4689/one.rs b/src/tools/rustfmt/tests/target/issue-4689/one.rs
new file mode 100644
index 00000000000..7735e34f3b5
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-4689/one.rs
@@ -0,0 +1,150 @@
+// rustfmt-version: One
+
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+    'tcx,
+    Error = fmt::Error,
+    Path = Self,
+    Region = Self,
+    Type = Self,
+    DynExistential = Self,
+    Const = Self,
+>
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + fmt::Write
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + fmt::Write1
+    + fmt::Write2
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    fmt::Write
+    + Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    >
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    fmt::Write
+    + Printer1<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + Printer2<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    >
+{
+    //
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+    FnMut() -> Thing<
+        WithType = LongItemName,
+        Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+    >,
+> {
+}
+fn f() -> Box<
+    FnMut() -> Thing<
+            WithType = LongItemName,
+            Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+        > + fmt::Write1
+        + fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+    F: Fn(
+        // this comment is deleted
+    ),
+{
+}
+fn foo<F>(foo2: F)
+where
+    F: Fn(
+            // this comment is deleted
+        ) + fmt::Write,
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+    F: FnMut(
+        &mut ProbeContext,
+        ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+        tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+    ),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+    F: FnMut(
+            &mut ProbeContext,
+            ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+            tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+        ) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+    mut entries: entryyyyyyyy,
+) -> (impl Fn(
+    AlphabeticalTraversal,
+    Seconddddddddddddddddddddddddddddddddddd,
+) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
+        + Sendddddddddddddddddddddddddddddddddddddddddddd) {
+}
+
+pub trait SomeTrait:
+    Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+    + Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+    for<'b> &'b Self: Send
+        + Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+        + Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
diff --git a/src/tools/rustfmt/tests/target/issue-4689/two.rs b/src/tools/rustfmt/tests/target/issue-4689/two.rs
new file mode 100644
index 00000000000..e3b5cd22810
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-4689/two.rs
@@ -0,0 +1,152 @@
+// rustfmt-version: Two
+
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    >
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + fmt::Write
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + fmt::Write1
+    + fmt::Write2
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    fmt::Write
+    + Printer<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    >
+{
+    //
+}
+pub trait PrettyPrinter<'tcx>:
+    fmt::Write
+    + Printer1<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    > + Printer2<
+        'tcx,
+        Error = fmt::Error,
+        Path = Self,
+        Region = Self,
+        Type = Self,
+        DynExistential = Self,
+        Const = Self,
+    >
+{
+    //
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+    FnMut() -> Thing<
+        WithType = LongItemName,
+        Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+    >,
+> {
+}
+fn f() -> Box<
+    FnMut() -> Thing<
+            WithType = LongItemName,
+            Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+        > + fmt::Write1
+        + fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+    F: Fn(
+        // this comment is deleted
+    ),
+{
+}
+fn foo<F>(foo2: F)
+where
+    F: Fn(
+            // this comment is deleted
+        ) + fmt::Write,
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+    F: FnMut(
+        &mut ProbeContext,
+        ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+        tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+    ),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+    F: FnMut(
+            &mut ProbeContext,
+            ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+            tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+        ) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+    mut entries: entryyyyyyyy,
+) -> (
+    impl Fn(
+        AlphabeticalTraversal,
+        Seconddddddddddddddddddddddddddddddddddd,
+    ) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
+    + Sendddddddddddddddddddddddddddddddddddddddddddd
+) {
+}
+
+pub trait SomeTrait:
+    Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+    + Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+    for<'b> &'b Self: Send
+        + Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+        + Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
diff --git a/src/tools/rustfmt/tests/target/issue-4791/issue_4928.rs b/src/tools/rustfmt/tests/target/issue-4791/issue_4928.rs
index 588656b535f..29f6bda9063 100644
--- a/src/tools/rustfmt/tests/target/issue-4791/issue_4928.rs
+++ b/src/tools/rustfmt/tests/target/issue-4791/issue_4928.rs
@@ -1,7 +1,7 @@
 // rustfmt-brace_style: SameLineWhere
 // rustfmt-comment_width: 100
 // rustfmt-edition: 2018
-// rustfmt-fn_args_layout: Compressed
+// rustfmt-fn_params_layout: Compressed
 // rustfmt-hard_tabs: false
 // rustfmt-match_block_trailing_comma: true
 // rustfmt-max_width: 100
diff --git a/src/tools/rustfmt/tests/target/issue-5358.rs b/src/tools/rustfmt/tests/target/issue-5358.rs
new file mode 100644
index 00000000000..d4bf4909ad7
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue-5358.rs
@@ -0,0 +1,4 @@
+// Test /* comment */ inside trait generics does not get duplicated.
+trait Test</* comment */ T> {}
+
+trait TestTwo</* comment */ T, /* comment */ V> {}
diff --git a/src/tools/rustfmt/tests/target/issue_1306.rs b/src/tools/rustfmt/tests/target/issue_1306.rs
new file mode 100644
index 00000000000..6bb514cdfe5
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_1306.rs
@@ -0,0 +1,33 @@
+// rustfmt-max_width: 160
+// rustfmt-fn_call_width: 96
+// rustfmt-fn_args_layout: Compressed
+// rustfmt-trailing_comma: Always
+// rustfmt-wrap_comments: true
+
+fn foo() {
+    for elem in try!(gen_epub_book::ops::parse_descriptor_file(
+        &mut try!(File::open(&opts.source_file.1).map_err(|_| {
+            gen_epub_book::Error::Io {
+                desc: "input file",
+                op: "open",
+                more: None,
+            }
+        })),
+        "input file"
+    )) {
+        println!("{}", elem);
+    }
+}
+
+fn write_content() {
+    io::copy(
+        try!(File::open(in_f).map_err(|_| {
+            Error::Io {
+                desc: "Content",
+                op: "open",
+                more: None,
+            }
+        })),
+        w,
+    );
+}
diff --git a/src/tools/rustfmt/tests/target/issue_3033.rs b/src/tools/rustfmt/tests/target/issue_3033.rs
new file mode 100644
index 00000000000..e12249a6da6
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_3033.rs
@@ -0,0 +1,2 @@
+use dom::bindings::codegen::Bindings::BluetoothRemoteGATTServerBinding::BluetoothRemoteGATTServerBinding::
+    BluetoothRemoteGATTServerMethods;
diff --git a/src/tools/rustfmt/tests/target/issue_3245.rs b/src/tools/rustfmt/tests/target/issue_3245.rs
new file mode 100644
index 00000000000..8f442f1181a
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_3245.rs
@@ -0,0 +1,4 @@
+fn main() {
+    let x = 1;
+    let y = 3;
+}
diff --git a/src/tools/rustfmt/tests/target/issue_3561.rs b/src/tools/rustfmt/tests/target/issue_3561.rs
new file mode 100644
index 00000000000..846a14d86a5
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_3561.rs
@@ -0,0 +1,7 @@
+fn main() {
+    7
+}
+
+fn main() {
+    7
+}
diff --git a/src/tools/rustfmt/tests/target/issue_4350.rs b/src/tools/rustfmt/tests/target/issue_4350.rs
new file mode 100644
index 00000000000..a94c5c32188
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_4350.rs
@@ -0,0 +1,13 @@
+//rustfmt-format_macro_bodies: true
+
+macro_rules! mto_text_left {
+    ($buf:ident, $n:ident, $pos:ident, $state:ident) => {{
+        let cursor = loop {
+            state = match iter.next() {
+                None if $pos == DP::Start => break last_char_idx($buf),
+                None /*some comment */ => break 0,
+            };
+        };
+        Ok(saturate_cursor($buf, cursor))
+    }};
+}
diff --git a/src/tools/rustfmt/tests/target/issue_5668.rs b/src/tools/rustfmt/tests/target/issue_5668.rs
new file mode 100644
index 00000000000..bbd9a530b81
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_5668.rs
@@ -0,0 +1,8 @@
+type Foo = impl Send;
+struct Struct<
+    const C: usize = {
+        let _: Foo = ();
+        //~^ ERROR: mismatched types
+        0
+    },
+>;
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/all.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/all.rs
new file mode 100644
index 00000000000..d0437ee10fd
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/all.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["*"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should skip this invocation
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/all_and_name.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/all_and_name.rs
new file mode 100644
index 00000000000..1f6722344fe
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/all_and_name.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["*","items"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should also skip this invocation, as the wildcard covers it
+renamed_items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/empty.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/empty.rs
new file mode 100644
index 00000000000..4a398cc59c6
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/empty.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: []
+
+// Should not skip this invocation
+items!(
+    const _: u8 = 0;
+);
+
+// Should not skip this invocation
+renamed_items!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/name.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/name.rs
new file mode 100644
index 00000000000..c4d577269c6
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/name.rs
@@ -0,0 +1,11 @@
+// rustfmt-skip_macro_invocations: ["items"]
+
+// Should skip this invocation
+items!(
+        const _: u8 = 0;
+);
+
+// Should not skip this invocation
+renamed_items!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/name_unknown.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/name_unknown.rs
new file mode 100644
index 00000000000..7ab1440395c
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/name_unknown.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["unknown"]
+
+// Should not skip this invocation
+items!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/names.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/names.rs
new file mode 100644
index 00000000000..c6b41ff93d7
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/names.rs
@@ -0,0 +1,16 @@
+// rustfmt-skip_macro_invocations: ["foo","bar"]
+
+// Should skip this invocation
+foo!(
+        const _: u8 = 0;
+);
+
+// Should skip this invocation
+bar!(
+        const _: u8 = 0;
+);
+
+// Should not skip this invocation
+baz!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_invocation_mismatch.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_invocation_mismatch.rs
new file mode 100644
index 00000000000..6e372c72695
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_invocation_mismatch.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["items"]
+
+// Should not skip this invocation
+self::items!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_match.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_match.rs
new file mode 100644
index 00000000000..9398918a9e1
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_match.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["self::items"]
+
+// Should skip this invocation
+self::items!(
+        const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_name_mismatch.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_name_mismatch.rs
new file mode 100644
index 00000000000..aa57a2a655c
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/path_qualified_name_mismatch.rs
@@ -0,0 +1,6 @@
+// rustfmt-skip_macro_invocations: ["self::items"]
+
+// Should not skip this invocation
+items!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/skip_macro_invocations/use_alias_examples.rs b/src/tools/rustfmt/tests/target/skip_macro_invocations/use_alias_examples.rs
new file mode 100644
index 00000000000..799dd8c08af
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/skip_macro_invocations/use_alias_examples.rs
@@ -0,0 +1,32 @@
+// rustfmt-skip_macro_invocations: ["aaa","ccc"]
+
+// These tests demonstrate a realistic use case with use aliases.
+// The use statements should not impact functionality in any way.
+
+use crate::{aaa, bbb, ddd};
+
+// No use alias, invocation in list
+// Should skip this invocation
+aaa!(
+        const _: u8 = 0;
+);
+
+// Use alias, invocation in list
+// Should skip this invocation
+use crate::bbb as ccc;
+ccc!(
+        const _: u8 = 0;
+);
+
+// Use alias, invocation not in list
+// Should not skip this invocation
+use crate::ddd as eee;
+eee!(
+    const _: u8 = 0;
+);
+
+// No use alias, invocation not in list
+// Should not skip this invocation
+fff!(
+    const _: u8 = 0;
+);
diff --git a/src/tools/rustfmt/tests/target/tuple.rs b/src/tools/rustfmt/tests/target/tuple.rs
index 68bb2f3bc28..24fcf8cfd7c 100644
--- a/src/tools/rustfmt/tests/target/tuple.rs
+++ b/src/tools/rustfmt/tests/target/tuple.rs
@@ -1,4 +1,4 @@
-// Test tuple litterals
+// Test tuple literals
 
 fn foo() {
     let a = (a, a, a, a, a);
diff --git a/src/tools/rustfmt/tests/target/wrap_comments_should_not_imply_format_doc_comments.rs b/src/tools/rustfmt/tests/target/wrap_comments_should_not_imply_format_doc_comments.rs
index d61d4d7c216..6ccecc7e0bb 100644
--- a/src/tools/rustfmt/tests/target/wrap_comments_should_not_imply_format_doc_comments.rs
+++ b/src/tools/rustfmt/tests/target/wrap_comments_should_not_imply_format_doc_comments.rs
@@ -10,7 +10,7 @@
 /// ```
 fn foo() {}
 
-/// A long commment for wrapping
+/// A long comment for wrapping
 /// This is a long long long long long long long long long long long long long
 /// long long long long long long long sentence.
 fn bar() {}
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index bc2edf634de..8ce19c8b514 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -59,7 +59,6 @@ const EXCEPTIONS_CRANELIFT: &[(&str, &str)] = &[
     ("cranelift-codegen", "Apache-2.0 WITH LLVM-exception"),
     ("cranelift-codegen-meta", "Apache-2.0 WITH LLVM-exception"),
     ("cranelift-codegen-shared", "Apache-2.0 WITH LLVM-exception"),
-    ("cranelift-egraph", "Apache-2.0 WITH LLVM-exception"),
     ("cranelift-entity", "Apache-2.0 WITH LLVM-exception"),
     ("cranelift-frontend", "Apache-2.0 WITH LLVM-exception"),
     ("cranelift-isle", "Apache-2.0 WITH LLVM-exception"),
@@ -286,7 +285,6 @@ const PERMITTED_CRANELIFT_DEPENDENCIES: &[&str] = &[
     "cranelift-codegen",
     "cranelift-codegen-meta",
     "cranelift-codegen-shared",
-    "cranelift-egraph",
     "cranelift-entity",
     "cranelift-frontend",
     "cranelift-isle",
@@ -321,10 +319,12 @@ const PERMITTED_CRANELIFT_DEPENDENCIES: &[&str] = &[
     "winapi-i686-pc-windows-gnu",
     "winapi-x86_64-pc-windows-gnu",
     "windows-sys",
+    "windows_aarch64_gnullvm",
     "windows_aarch64_msvc",
     "windows_i686_gnu",
     "windows_i686_msvc",
     "windows_x86_64_gnu",
+    "windows_x86_64_gnullvm",
     "windows_x86_64_msvc",
 ];
 
diff --git a/src/tools/tidy/src/error_codes.rs b/src/tools/tidy/src/error_codes.rs
index 5b84b51a035..6bb4d32f87d 100644
--- a/src/tools/tidy/src/error_codes.rs
+++ b/src/tools/tidy/src/error_codes.rs
@@ -31,7 +31,7 @@ const IGNORE_DOCTEST_CHECK: &[&str] = &["E0464", "E0570", "E0601", "E0602", "E06
 
 // Error codes that don't yet have a UI test. This list will eventually be removed.
 const IGNORE_UI_TEST_CHECK: &[&str] =
-    &["E0461", "E0465", "E0476", "E0514", "E0523", "E0554", "E0640", "E0717", "E0729", "E0789"];
+    &["E0461", "E0465", "E0476", "E0514", "E0523", "E0554", "E0640", "E0717", "E0729"];
 
 macro_rules! verbose_print {
     ($verbose:expr, $($fmt:tt)*) => {
diff --git a/tests/codegen/avr/avr-func-addrspace.rs b/tests/codegen/avr/avr-func-addrspace.rs
index e9740e30da4..bc11e108124 100644
--- a/tests/codegen/avr/avr-func-addrspace.rs
+++ b/tests/codegen/avr/avr-func-addrspace.rs
@@ -109,3 +109,28 @@ pub unsafe fn transmute_fn_ptr_to_data(x: fn()) -> *const () {
     // as long as it doesn't cause a verifier error by using `bitcast`.
     transmute(x)
 }
+
+pub enum Either<T, U> { A(T), B(U) }
+
+// Previously, we would codegen this as passing/returning a scalar pair of `{ i8, ptr }`,
+// with the `ptr` field representing both `&i32` and `fn()` depending on the variant.
+// This is incorrect, because `fn()` should be `ptr addrspace(1)`, not `ptr`.
+
+// CHECK: define{{.+}}void @should_not_combine_addrspace({{.+\*|ptr}}{{.+}}sret{{.+}}%0, {{.+\*|ptr}}{{.+}}%x)
+#[no_mangle]
+#[inline(never)]
+pub fn should_not_combine_addrspace(x: Either<&i32, fn()>) -> Either<&i32, fn()> {
+    x
+}
+
+// The incorrectness described above would result in us producing (after optimizations)
+// a `ptrtoint`/`inttoptr` roundtrip to convert from `ptr` to `ptr addrspace(1)`.
+
+// CHECK-LABEL: @call_with_fn_ptr
+#[no_mangle]
+pub fn call_with_fn_ptr<'a>(f: fn()) -> Either<&'a i32, fn()> {
+    // CHECK-NOT: ptrtoint
+    // CHECK-NOT: inttoptr
+    // CHECK: call addrspace(1) void @should_not_combine_addrspace
+    should_not_combine_addrspace(Either::B(f))
+}
diff --git a/tests/codegen/debug-vtable.rs b/tests/codegen/debug-vtable.rs
index bdd312878ec..d82b737de0b 100644
--- a/tests/codegen/debug-vtable.rs
+++ b/tests/codegen/debug-vtable.rs
@@ -9,6 +9,14 @@
 // compile-flags: -Cdebuginfo=2 -Copt-level=0 -Csymbol-mangling-version=v0
 // ignore-tidy-linelength
 
+// Make sure that vtables don't have the unnamed_addr attribute when debuginfo is enabled.
+// This helps debuggers more reliably map from dyn pointer to concrete type.
+// CHECK: @vtable.0 = private constant <{
+// CHECK: @vtable.1 = private constant <{
+// CHECK: @vtable.2 = private constant <{
+// CHECK: @vtable.3 = private constant <{
+// CHECK: @vtable.4 = private constant <{
+
 // NONMSVC: ![[USIZE:[0-9]+]] = !DIBasicType(name: "usize"
 // MSVC: ![[USIZE:[0-9]+]] = !DIDerivedType(tag: DW_TAG_typedef, name: "usize"
 // NONMSVC: ![[PTR:[0-9]+]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "*const ()"
diff --git a/tests/codegen/option-nonzero-eq.rs b/tests/codegen/option-nonzero-eq.rs
index 598dcc19b49..835decd3e5f 100644
--- a/tests/codegen/option-nonzero-eq.rs
+++ b/tests/codegen/option-nonzero-eq.rs
@@ -3,6 +3,7 @@
 #![crate_type = "lib"]
 
 extern crate core;
+use core::cmp::Ordering;
 use core::num::{NonZeroU32, NonZeroI64};
 use core::ptr::NonNull;
 
@@ -32,3 +33,12 @@ pub fn non_null_eq(l: Option<NonNull<u8>>, r: Option<NonNull<u8>>) -> bool {
     // CHECK-NEXT: ret i1
     l == r
 }
+
+// CHECK-lABEL: @ordering_eq
+#[no_mangle]
+pub fn ordering_eq(l: Option<Ordering>, r: Option<Ordering>) -> bool {
+    // CHECK: start:
+    // CHECK-NEXT: icmp eq i8
+    // CHECK-NEXT: ret i1
+    l == r
+}
diff --git a/tests/debuginfo/embedded-visualizer.rs b/tests/debuginfo/embedded-visualizer.rs
index 0269015b466..2898e75e0ee 100644
--- a/tests/debuginfo/embedded-visualizer.rs
+++ b/tests/debuginfo/embedded-visualizer.rs
@@ -1,6 +1,7 @@
 // compile-flags:-g
 // min-gdb-version: 8.1
 // ignore-lldb
+// ignore-windows-gnu // emit_debug_gdb_scripts is disabled on Windows
 
 // === CDB TESTS ==================================================================================
 
diff --git a/tests/debuginfo/numeric-types.rs b/tests/debuginfo/numeric-types.rs
index c41c9ee21df..c122112e6c7 100644
--- a/tests/debuginfo/numeric-types.rs
+++ b/tests/debuginfo/numeric-types.rs
@@ -1,6 +1,7 @@
 // compile-flags:-g
 
 // min-gdb-version: 8.1
+// ignore-windows-gnu // emit_debug_gdb_scripts is disabled on Windows
 
 // Tests the visualizations for `NonZero{I,U}{8,16,32,64,128,size}`, `Wrapping<T>` and
 // `Atomic{Bool,I8,I16,I32,I64,Isize,U8,U16,U32,U64,Usize}` located in `libcore.natvis`.
diff --git a/tests/debuginfo/vec-slices.rs b/tests/debuginfo/vec-slices.rs
index 7d88e45caf2..de4099a7f50 100644
--- a/tests/debuginfo/vec-slices.rs
+++ b/tests/debuginfo/vec-slices.rs
@@ -1,4 +1,3 @@
-// ignore-windows
 // min-lldb-version: 310
 
 // compile-flags:-g
diff --git a/tests/mir-opt/76803_regression.encode.SimplifyBranchSame.diff b/tests/mir-opt/76803_regression.encode.SimplifyBranchSame.diff
deleted file mode 100644
index 9780332d8bf..00000000000
--- a/tests/mir-opt/76803_regression.encode.SimplifyBranchSame.diff
+++ /dev/null
@@ -1,29 +0,0 @@
-- // MIR for `encode` before SimplifyBranchSame
-+ // MIR for `encode` after SimplifyBranchSame
-  
-  fn encode(_1: Type) -> Type {
-      debug v => _1;                       // in scope 0 at $DIR/76803_regression.rs:+0:15: +0:16
-      let mut _0: Type;                    // return place in scope 0 at $DIR/76803_regression.rs:+0:27: +0:31
-      let mut _2: isize;                   // in scope 0 at $DIR/76803_regression.rs:+2:9: +2:16
-  
-      bb0: {
-          _2 = discriminant(_1);           // scope 0 at $DIR/76803_regression.rs:+1:11: +1:12
-          switchInt(move _2) -> [0: bb2, otherwise: bb1]; // scope 0 at $DIR/76803_regression.rs:+1:5: +1:12
-      }
-  
-      bb1: {
-          _0 = move _1;                    // scope 0 at $DIR/76803_regression.rs:+3:14: +3:15
-          goto -> bb3;                     // scope 0 at $DIR/76803_regression.rs:+3:14: +3:15
-      }
-  
-      bb2: {
-          Deinit(_0);                      // scope 0 at $DIR/76803_regression.rs:+2:20: +2:27
-          discriminant(_0) = 1;            // scope 0 at $DIR/76803_regression.rs:+2:20: +2:27
-          goto -> bb3;                     // scope 0 at $DIR/76803_regression.rs:+2:20: +2:27
-      }
-  
-      bb3: {
-          return;                          // scope 0 at $DIR/76803_regression.rs:+5:2: +5:2
-      }
-  }
-  
diff --git a/tests/mir-opt/76803_regression.rs b/tests/mir-opt/76803_regression.rs
deleted file mode 100644
index 05dc3c97841..00000000000
--- a/tests/mir-opt/76803_regression.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-// compile-flags: -Z mir-opt-level=1
-// EMIT_MIR 76803_regression.encode.SimplifyBranchSame.diff
-
-#[derive(Debug, Eq, PartialEq)]
-pub enum Type {
-    A,
-    B,
-}
-
-pub fn encode(v: Type) -> Type {
-    match v {
-        Type::A => Type::B,
-        _ => v,
-    }
-}
-
-fn main() {
-    assert_eq!(Type::B, encode(Type::A));
-}
diff --git a/tests/mir-opt/building/async_await.b-{closure#0}.generator_resume.0.mir b/tests/mir-opt/building/async_await.b-{closure#0}.generator_resume.0.mir
index 05edc4797d4..1449247aeda 100644
--- a/tests/mir-opt/building/async_await.b-{closure#0}.generator_resume.0.mir
+++ b/tests/mir-opt/building/async_await.b-{closure#0}.generator_resume.0.mir
@@ -1,8 +1,22 @@
 // MIR for `b::{closure#0}` 0 generator_resume
 /* generator_layout = GeneratorLayout {
     field_tys: {
-        _0: impl std::future::Future<Output = ()>,
-        _1: impl std::future::Future<Output = ()>,
+        _0: GeneratorSavedTy {
+            ty: impl std::future::Future<Output = ()>,
+            source_info: SourceInfo {
+                span: $DIR/async_await.rs:15:8: 15:14 (#9),
+                scope: scope[0],
+            },
+            ignore_for_traits: false,
+        },
+        _1: GeneratorSavedTy {
+            ty: impl std::future::Future<Output = ()>,
+            source_info: SourceInfo {
+                span: $DIR/async_await.rs:16:8: 16:14 (#12),
+                scope: scope[0],
+            },
+            ignore_for_traits: false,
+        },
     },
     variant_fields: {
         Unresumed(0): [],
diff --git a/tests/mir-opt/building/custom/arrays.arrays.built.after.mir b/tests/mir-opt/building/custom/arrays.arrays.built.after.mir
new file mode 100644
index 00000000000..4c921272885
--- /dev/null
+++ b/tests/mir-opt/building/custom/arrays.arrays.built.after.mir
@@ -0,0 +1,14 @@
+// MIR for `arrays` after built
+
+fn arrays() -> usize {
+    let mut _0: usize;                   // return place in scope 0 at $DIR/arrays.rs:+0:32: +0:37
+    let mut _1: [i32; C];                // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+    let mut _2: usize;                   // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+
+    bb0: {
+        _1 = [const 5_i32; C];           // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+        _2 = Len(_1);                    // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+        _0 = _2;                         // scope 0 at $DIR/arrays.rs:+4:9: +4:16
+        return;                          // scope 0 at $DIR/arrays.rs:+5:9: +5:17
+    }
+}
diff --git a/tests/mir-opt/building/custom/arrays.rs b/tests/mir-opt/building/custom/arrays.rs
new file mode 100644
index 00000000000..8e0a1fd7a43
--- /dev/null
+++ b/tests/mir-opt/building/custom/arrays.rs
@@ -0,0 +1,19 @@
+#![feature(custom_mir, core_intrinsics, inline_const)]
+
+extern crate core;
+use core::intrinsics::mir::*;
+
+// EMIT_MIR arrays.arrays.built.after.mir
+#[custom_mir(dialect = "built")]
+fn arrays<const C: usize>() -> usize {
+    mir!({
+        let x = [5_i32; C];
+        let c = Len(x);
+        RET = c;
+        Return()
+    })
+}
+
+fn main() {
+    assert_eq!(arrays::<20>(), 20);
+}
diff --git a/tests/mir-opt/building/custom/enums.rs b/tests/mir-opt/building/custom/enums.rs
index e5cd4563778..eca5b792ec0 100644
--- a/tests/mir-opt/building/custom/enums.rs
+++ b/tests/mir-opt/building/custom/enums.rs
@@ -86,6 +86,7 @@ fn switch_option_repr(option: Bool) -> bool {
 #[custom_mir(dialect = "runtime", phase = "initial")]
 fn set_discr(option: &mut Option<()>) {
     mir!({
+        Deinit(*option);
         SetDiscriminant(*option, 0);
         Return()
     })
diff --git a/tests/mir-opt/building/custom/enums.set_discr.built.after.mir b/tests/mir-opt/building/custom/enums.set_discr.built.after.mir
index 7de9ed0983f..6d07473658a 100644
--- a/tests/mir-opt/building/custom/enums.set_discr.built.after.mir
+++ b/tests/mir-opt/building/custom/enums.set_discr.built.after.mir
@@ -4,7 +4,8 @@ fn set_discr(_1: &mut Option<()>) -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/enums.rs:+0:39: +0:39
 
     bb0: {
-        discriminant((*_1)) = 0;         // scope 0 at $DIR/enums.rs:+2:9: +2:36
-        return;                          // scope 0 at $DIR/enums.rs:+3:9: +3:17
+        Deinit((*_1));                   // scope 0 at $DIR/enums.rs:+2:9: +2:24
+        discriminant((*_1)) = 0;         // scope 0 at $DIR/enums.rs:+3:9: +3:36
+        return;                          // scope 0 at $DIR/enums.rs:+4:9: +4:17
     }
 }
diff --git a/tests/mir-opt/building/custom/operators.f.built.after.mir b/tests/mir-opt/building/custom/operators.f.built.after.mir
new file mode 100644
index 00000000000..cb43d5e6ed7
--- /dev/null
+++ b/tests/mir-opt/building/custom/operators.f.built.after.mir
@@ -0,0 +1,30 @@
+// MIR for `f` after built
+
+fn f(_1: i32, _2: bool) -> i32 {
+    let mut _0: i32;                     // return place in scope 0 at $DIR/operators.rs:+0:30: +0:33
+    let mut _3: (i32, bool);             // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+
+    bb0: {
+        _1 = Neg(_1);                    // scope 0 at $DIR/operators.rs:+2:9: +2:15
+        _2 = Not(_2);                    // scope 0 at $DIR/operators.rs:+3:9: +3:15
+        _1 = Add(_1, _1);                // scope 0 at $DIR/operators.rs:+4:9: +4:18
+        _1 = Sub(_1, _1);                // scope 0 at $DIR/operators.rs:+5:9: +5:18
+        _1 = Mul(_1, _1);                // scope 0 at $DIR/operators.rs:+6:9: +6:18
+        _1 = Div(_1, _1);                // scope 0 at $DIR/operators.rs:+7:9: +7:18
+        _1 = Rem(_1, _1);                // scope 0 at $DIR/operators.rs:+8:9: +8:18
+        _1 = BitXor(_1, _1);             // scope 0 at $DIR/operators.rs:+9:9: +9:18
+        _1 = BitAnd(_1, _1);             // scope 0 at $DIR/operators.rs:+10:9: +10:18
+        _1 = Shl(_1, _1);                // scope 0 at $DIR/operators.rs:+11:9: +11:19
+        _1 = Shr(_1, _1);                // scope 0 at $DIR/operators.rs:+12:9: +12:19
+        _2 = Eq(_1, _1);                 // scope 0 at $DIR/operators.rs:+13:9: +13:19
+        _2 = Lt(_1, _1);                 // scope 0 at $DIR/operators.rs:+14:9: +14:18
+        _2 = Le(_1, _1);                 // scope 0 at $DIR/operators.rs:+15:9: +15:19
+        _2 = Ge(_1, _1);                 // scope 0 at $DIR/operators.rs:+16:9: +16:19
+        _2 = Gt(_1, _1);                 // scope 0 at $DIR/operators.rs:+17:9: +17:18
+        _3 = CheckedAdd(_1, _1);         // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+        _2 = (_3.1: bool);               // scope 0 at $DIR/operators.rs:+19:9: +19:18
+        _1 = (_3.0: i32);                // scope 0 at $DIR/operators.rs:+20:9: +20:18
+        _0 = _1;                         // scope 0 at $DIR/operators.rs:+21:9: +21:16
+        return;                          // scope 0 at $DIR/operators.rs:+22:9: +22:17
+    }
+}
diff --git a/tests/mir-opt/building/custom/operators.rs b/tests/mir-opt/building/custom/operators.rs
new file mode 100644
index 00000000000..db7a48317d9
--- /dev/null
+++ b/tests/mir-opt/building/custom/operators.rs
@@ -0,0 +1,31 @@
+// compile-flags: --crate-type=lib
+#![feature(custom_mir, core_intrinsics, inline_const)]
+use std::intrinsics::mir::*;
+
+// EMIT_MIR operators.f.built.after.mir
+#[custom_mir(dialect = "built")]
+pub fn f(a: i32, b: bool) -> i32 {
+    mir!({
+        a = -a;
+        b = !b;
+        a = a + a;
+        a = a - a;
+        a = a * a;
+        a = a / a;
+        a = a % a;
+        a = a ^ a;
+        a = a & a;
+        a = a << a;
+        a = a >> a;
+        b = a == a;
+        b = a < a;
+        b = a <= a;
+        b = a >= a;
+        b = a > a;
+        let res = Checked(a + a);
+        b = res.1;
+        a = res.0;
+        RET = a;
+        Return()
+    })
+}
diff --git a/tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff b/tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff
index dd548adde7e..5e587be1f16 100644
--- a/tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff
+++ b/tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff
@@ -64,17 +64,8 @@
           _3 = const 3_u8;                 // scope 2 at $DIR/const_debuginfo.rs:+3:13: +3:16
           StorageLive(_4);                 // scope 3 at $DIR/const_debuginfo.rs:+4:9: +4:12
           StorageLive(_5);                 // scope 3 at $DIR/const_debuginfo.rs:+4:15: +4:20
-          StorageLive(_6);                 // scope 3 at $DIR/const_debuginfo.rs:+4:15: +4:16
-          _6 = const 1_u8;                 // scope 3 at $DIR/const_debuginfo.rs:+4:15: +4:16
-          StorageLive(_7);                 // scope 3 at $DIR/const_debuginfo.rs:+4:19: +4:20
-          _7 = const 2_u8;                 // scope 3 at $DIR/const_debuginfo.rs:+4:19: +4:20
           _5 = const 3_u8;                 // scope 3 at $DIR/const_debuginfo.rs:+4:15: +4:20
-          StorageDead(_7);                 // scope 3 at $DIR/const_debuginfo.rs:+4:19: +4:20
-          StorageDead(_6);                 // scope 3 at $DIR/const_debuginfo.rs:+4:19: +4:20
-          StorageLive(_8);                 // scope 3 at $DIR/const_debuginfo.rs:+4:23: +4:24
-          _8 = const 3_u8;                 // scope 3 at $DIR/const_debuginfo.rs:+4:23: +4:24
           _4 = const 6_u8;                 // scope 3 at $DIR/const_debuginfo.rs:+4:15: +4:24
-          StorageDead(_8);                 // scope 3 at $DIR/const_debuginfo.rs:+4:23: +4:24
           StorageDead(_5);                 // scope 3 at $DIR/const_debuginfo.rs:+4:23: +4:24
           StorageLive(_9);                 // scope 4 at $DIR/const_debuginfo.rs:+6:9: +6:10
           _9 = const "hello, world!";      // scope 4 at $DIR/const_debuginfo.rs:+6:13: +6:28
@@ -117,9 +108,6 @@
           StorageDead(_16);                // scope 5 at $DIR/const_debuginfo.rs:+14:1: +14:2
           StorageDead(_9);                 // scope 4 at $DIR/const_debuginfo.rs:+14:1: +14:2
           StorageDead(_4);                 // scope 3 at $DIR/const_debuginfo.rs:+14:1: +14:2
-          StorageDead(_3);                 // scope 2 at $DIR/const_debuginfo.rs:+14:1: +14:2
-          StorageDead(_2);                 // scope 1 at $DIR/const_debuginfo.rs:+14:1: +14:2
-          StorageDead(_1);                 // scope 0 at $DIR/const_debuginfo.rs:+14:1: +14:2
           return;                          // scope 0 at $DIR/const_debuginfo.rs:+14:2: +14:2
       }
   }
diff --git a/tests/mir-opt/const_prop/bad_op_mod_by_zero.main.ConstProp.diff b/tests/mir-opt/const_prop/bad_op_mod_by_zero.main.ConstProp.diff
index 8485703e39f..e085a88b2da 100644
--- a/tests/mir-opt/const_prop/bad_op_mod_by_zero.main.ConstProp.diff
+++ b/tests/mir-opt/const_prop/bad_op_mod_by_zero.main.ConstProp.diff
@@ -21,32 +21,25 @@
           StorageLive(_1);                 // scope 0 at $DIR/bad_op_mod_by_zero.rs:+1:9: +1:10
           _1 = const 0_i32;                // scope 0 at $DIR/bad_op_mod_by_zero.rs:+1:13: +1:14
           StorageLive(_2);                 // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:9: +2:11
-          StorageLive(_3);                 // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:18: +2:19
--         _3 = _1;                         // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:18: +2:19
--         _4 = Eq(_3, const 0_i32);        // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
+-         _4 = Eq(_1, const 0_i32);        // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 -         assert(!move _4, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> bb1; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
-+         _3 = const 0_i32;                // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:18: +2:19
 +         _4 = const true;                 // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 +         assert(!const true, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> bb1; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
       }
   
       bb1: {
--         _5 = Eq(_3, const -1_i32);       // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
+          _5 = Eq(_1, const -1_i32);       // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 -         _6 = Eq(const 1_i32, const i32::MIN); // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 -         _7 = BitAnd(move _5, move _6);   // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
--         assert(!move _7, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _3) -> bb2; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
-+         _5 = const false;                // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
+-         assert(!move _7, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _1) -> bb2; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 +         _6 = const false;                // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
 +         _7 = const false;                // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
-+         assert(!const false, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, const 0_i32) -> bb2; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
++         assert(!const false, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _1) -> bb2; // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
       }
   
       bb2: {
--         _2 = Rem(const 1_i32, move _3);  // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
-+         _2 = Rem(const 1_i32, const 0_i32); // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
-          StorageDead(_3);                 // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:18: +2:19
+          _2 = Rem(const 1_i32, _1);       // scope 1 at $DIR/bad_op_mod_by_zero.rs:+2:14: +2:19
           StorageDead(_2);                 // scope 1 at $DIR/bad_op_mod_by_zero.rs:+3:1: +3:2
-          StorageDead(_1);                 // scope 0 at $DIR/bad_op_mod_by_zero.rs:+3:1: +3:2
           return;                          // scope 0 at $DIR/bad_op_mod_by_zero.rs:+3:2: +3:2
       }
   }
diff --git a/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.32bit.diff b/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.32bit.diff
index 27e41d4869d..38d402b8f21 100644
--- a/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.32bit.diff
@@ -23,24 +23,21 @@
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:9: +1:10
           StorageLive(_2);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
-          StorageLive(_3);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           _8 = const _;                    // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
                                            // mir::Constant
                                            // + span: $DIR/bad_op_unsafe_oob_for_slices.rs:5:25: 5:35
                                            // + literal: Const { ty: &[i32; 3], val: Unevaluated(main, [], Some(promoted[0])) }
-          _3 = _8;                         // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
-          _2 = &raw const (*_3);           // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
+          _2 = &raw const (*_8);           // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           _1 = move _2 as *const [i32] (Pointer(Unsize)); // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           StorageDead(_2);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:34: +1:35
-          StorageDead(_3);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:35: +1:36
           StorageLive(_4);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:13: +3:15
           StorageLive(_5);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:23: +3:24
           _5 = const 3_usize;              // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:23: +3:24
-          _6 = Len((*_1));                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
+          _6 = const 3_usize;              // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
 -         _7 = Lt(_5, _6);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
 -         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
-+         _7 = Lt(const 3_usize, _6);      // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
-+         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, const 3_usize) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
++         _7 = const false;                // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
       }
   
       bb1: {
diff --git a/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.64bit.diff b/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.64bit.diff
index 27e41d4869d..38d402b8f21 100644
--- a/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.64bit.diff
@@ -23,24 +23,21 @@
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:9: +1:10
           StorageLive(_2);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
-          StorageLive(_3);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           _8 = const _;                    // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
                                            // mir::Constant
                                            // + span: $DIR/bad_op_unsafe_oob_for_slices.rs:5:25: 5:35
                                            // + literal: Const { ty: &[i32; 3], val: Unevaluated(main, [], Some(promoted[0])) }
-          _3 = _8;                         // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
-          _2 = &raw const (*_3);           // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
+          _2 = &raw const (*_8);           // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           _1 = move _2 as *const [i32] (Pointer(Unsize)); // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:25: +1:35
           StorageDead(_2);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:34: +1:35
-          StorageDead(_3);                 // scope 0 at $DIR/bad_op_unsafe_oob_for_slices.rs:+1:35: +1:36
           StorageLive(_4);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:13: +3:15
           StorageLive(_5);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:23: +3:24
           _5 = const 3_usize;              // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:23: +3:24
-          _6 = Len((*_1));                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
+          _6 = const 3_usize;              // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
 -         _7 = Lt(_5, _6);                 // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
 -         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
-+         _7 = Lt(const 3_usize, _6);      // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
-+         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, const 3_usize) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
++         _7 = const false;                // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> bb1; // scope 2 at $DIR/bad_op_unsafe_oob_for_slices.rs:+3:18: +3:25
       }
   
       bb1: {
diff --git a/tests/mir-opt/const_prop/boolean_identities.test.ConstProp.diff b/tests/mir-opt/const_prop/boolean_identities.test.ConstProp.diff
index 0de80091753..549b4711e87 100644
--- a/tests/mir-opt/const_prop/boolean_identities.test.ConstProp.diff
+++ b/tests/mir-opt/const_prop/boolean_identities.test.ConstProp.diff
@@ -12,18 +12,12 @@
   
       bb0: {
           StorageLive(_3);                 // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:15
-          StorageLive(_4);                 // scope 0 at $DIR/boolean_identities.rs:+1:6: +1:7
-          _4 = _2;                         // scope 0 at $DIR/boolean_identities.rs:+1:6: +1:7
--         _3 = BitOr(move _4, const true); // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:15
+-         _3 = BitOr(_2, const true);      // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:15
 +         _3 = const true;                 // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:15
-          StorageDead(_4);                 // scope 0 at $DIR/boolean_identities.rs:+1:14: +1:15
           StorageLive(_5);                 // scope 0 at $DIR/boolean_identities.rs:+1:18: +1:29
-          StorageLive(_6);                 // scope 0 at $DIR/boolean_identities.rs:+1:19: +1:20
-          _6 = _1;                         // scope 0 at $DIR/boolean_identities.rs:+1:19: +1:20
--         _5 = BitAnd(move _6, const false); // scope 0 at $DIR/boolean_identities.rs:+1:18: +1:29
-+         _5 = const false;                // scope 0 at $DIR/boolean_identities.rs:+1:18: +1:29
-          StorageDead(_6);                 // scope 0 at $DIR/boolean_identities.rs:+1:28: +1:29
+-         _5 = BitAnd(_1, const false);    // scope 0 at $DIR/boolean_identities.rs:+1:18: +1:29
 -         _0 = BitAnd(move _3, move _5);   // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:29
++         _5 = const false;                // scope 0 at $DIR/boolean_identities.rs:+1:18: +1:29
 +         _0 = const false;                // scope 0 at $DIR/boolean_identities.rs:+1:5: +1:29
           StorageDead(_5);                 // scope 0 at $DIR/boolean_identities.rs:+1:28: +1:29
           StorageDead(_3);                 // scope 0 at $DIR/boolean_identities.rs:+1:28: +1:29
diff --git a/tests/mir-opt/const_prop/mult_by_zero.test.ConstProp.diff b/tests/mir-opt/const_prop/mult_by_zero.test.ConstProp.diff
index 629c8e60148..1cfe47d0a86 100644
--- a/tests/mir-opt/const_prop/mult_by_zero.test.ConstProp.diff
+++ b/tests/mir-opt/const_prop/mult_by_zero.test.ConstProp.diff
@@ -7,11 +7,8 @@
       let mut _2: i32;                     // in scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:4
   
       bb0: {
-          StorageLive(_2);                 // scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:4
-          _2 = _1;                         // scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:4
--         _0 = Mul(move _2, const 0_i32);  // scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:8
+-         _0 = Mul(_1, const 0_i32);       // scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:8
 +         _0 = const 0_i32;                // scope 0 at $DIR/mult_by_zero.rs:+1:3: +1:8
-          StorageDead(_2);                 // scope 0 at $DIR/mult_by_zero.rs:+1:7: +1:8
           return;                          // scope 0 at $DIR/mult_by_zero.rs:+2:2: +2:2
       }
   }
diff --git a/tests/mir-opt/const_prop/ref_deref.main.ConstProp.diff b/tests/mir-opt/const_prop/ref_deref.main.ConstProp.diff
index 8a73f0390e1..924a267f3d8 100644
--- a/tests/mir-opt/const_prop/ref_deref.main.ConstProp.diff
+++ b/tests/mir-opt/const_prop/ref_deref.main.ConstProp.diff
@@ -13,14 +13,13 @@
           StorageLive(_2);                 // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
           _4 = const _;                    // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
                                            // mir::Constant
-                                           // + span: $DIR/ref_deref.rs:6:6: 6:10
+                                           // + span: $DIR/ref_deref.rs:5:6: 5:10
                                            // + literal: Const { ty: &i32, val: Unevaluated(main, [], Some(promoted[0])) }
-          _2 = _4;                         // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
--         _1 = (*_2);                      // scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
-+         _1 = const 4_i32;                // scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
+          _2 = &(*_4);                     // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
+          _1 = (*_2);                      // scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
           StorageDead(_2);                 // scope 0 at $DIR/ref_deref.rs:+1:10: +1:11
           StorageDead(_1);                 // scope 0 at $DIR/ref_deref.rs:+1:10: +1:11
-          nop;                             // scope 0 at $DIR/ref_deref.rs:+0:11: +2:2
+          _0 = const ();                   // scope 0 at $DIR/ref_deref.rs:+0:11: +2:2
           return;                          // scope 0 at $DIR/ref_deref.rs:+2:2: +2:2
       }
   }
diff --git a/tests/mir-opt/const_prop/ref_deref.main.PromoteTemps.diff b/tests/mir-opt/const_prop/ref_deref.main.PromoteTemps.diff
deleted file mode 100644
index 015ec4d078c..00000000000
--- a/tests/mir-opt/const_prop/ref_deref.main.PromoteTemps.diff
+++ /dev/null
@@ -1,30 +0,0 @@
-- // MIR for `main` before PromoteTemps
-+ // MIR for `main` after PromoteTemps
-  
-  fn main() -> () {
-      let mut _0: ();                      // return place in scope 0 at $DIR/ref_deref.rs:+0:11: +0:11
-      let _1: i32;                         // in scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
-      let mut _2: &i32;                    // in scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
-      let _3: i32;                         // in scope 0 at $DIR/ref_deref.rs:+1:8: +1:9
-+     let mut _4: &i32;                    // in scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
-  
-      bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
-          StorageLive(_2);                 // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
--         StorageLive(_3);                 // scope 0 at $DIR/ref_deref.rs:+1:8: +1:9
--         _3 = const 4_i32;                // scope 0 at $DIR/ref_deref.rs:+1:8: +1:9
--         _2 = &_3;                        // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
-+         _4 = const _;                    // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
-+                                          // mir::Constant
-+                                          // + span: $DIR/ref_deref.rs:6:6: 6:10
-+                                          // + literal: Const { ty: &i32, val: Unevaluated(main, [], Some(promoted[0])) }
-+         _2 = &(*_4);                     // scope 0 at $DIR/ref_deref.rs:+1:6: +1:10
-          _1 = (*_2);                      // scope 0 at $DIR/ref_deref.rs:+1:5: +1:10
--         StorageDead(_3);                 // scope 0 at $DIR/ref_deref.rs:+1:10: +1:11
-          StorageDead(_2);                 // scope 0 at $DIR/ref_deref.rs:+1:10: +1:11
-          StorageDead(_1);                 // scope 0 at $DIR/ref_deref.rs:+1:10: +1:11
-          _0 = const ();                   // scope 0 at $DIR/ref_deref.rs:+0:11: +2:2
-          return;                          // scope 0 at $DIR/ref_deref.rs:+2:2: +2:2
-      }
-  }
-  
diff --git a/tests/mir-opt/const_prop/ref_deref.rs b/tests/mir-opt/const_prop/ref_deref.rs
index d2549c8b6aa..76e56916af0 100644
--- a/tests/mir-opt/const_prop/ref_deref.rs
+++ b/tests/mir-opt/const_prop/ref_deref.rs
@@ -1,5 +1,4 @@
-// compile-flags: -Zmir-enable-passes=-SimplifyLocals-before-const-prop
-// EMIT_MIR ref_deref.main.PromoteTemps.diff
+// unit-test: ConstProp
 // EMIT_MIR ref_deref.main.ConstProp.diff
 
 fn main() {
diff --git a/tests/mir-opt/const_prop/ref_deref_project.main.ConstProp.diff b/tests/mir-opt/const_prop/ref_deref_project.main.ConstProp.diff
index ec3d9043315..59095b44837 100644
--- a/tests/mir-opt/const_prop/ref_deref_project.main.ConstProp.diff
+++ b/tests/mir-opt/const_prop/ref_deref_project.main.ConstProp.diff
@@ -13,13 +13,13 @@
           StorageLive(_2);                 // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
           _4 = const _;                    // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
                                            // mir::Constant
-                                           // + span: $DIR/ref_deref_project.rs:6:6: 6:17
+                                           // + span: $DIR/ref_deref_project.rs:5:6: 5:17
                                            // + literal: Const { ty: &(i32, i32), val: Unevaluated(main, [], Some(promoted[0])) }
           _2 = &((*_4).1: i32);            // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
           _1 = (*_2);                      // scope 0 at $DIR/ref_deref_project.rs:+1:5: +1:17
           StorageDead(_2);                 // scope 0 at $DIR/ref_deref_project.rs:+1:17: +1:18
           StorageDead(_1);                 // scope 0 at $DIR/ref_deref_project.rs:+1:17: +1:18
-          nop;                             // scope 0 at $DIR/ref_deref_project.rs:+0:11: +2:2
+          _0 = const ();                   // scope 0 at $DIR/ref_deref_project.rs:+0:11: +2:2
           return;                          // scope 0 at $DIR/ref_deref_project.rs:+2:2: +2:2
       }
   }
diff --git a/tests/mir-opt/const_prop/ref_deref_project.main.PromoteTemps.diff b/tests/mir-opt/const_prop/ref_deref_project.main.PromoteTemps.diff
deleted file mode 100644
index cd0616e65ba..00000000000
--- a/tests/mir-opt/const_prop/ref_deref_project.main.PromoteTemps.diff
+++ /dev/null
@@ -1,30 +0,0 @@
-- // MIR for `main` before PromoteTemps
-+ // MIR for `main` after PromoteTemps
-  
-  fn main() -> () {
-      let mut _0: ();                      // return place in scope 0 at $DIR/ref_deref_project.rs:+0:11: +0:11
-      let _1: i32;                         // in scope 0 at $DIR/ref_deref_project.rs:+1:5: +1:17
-      let mut _2: &i32;                    // in scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
-      let _3: (i32, i32);                  // in scope 0 at $DIR/ref_deref_project.rs:+1:8: +1:14
-+     let mut _4: &(i32, i32);             // in scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
-  
-      bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/ref_deref_project.rs:+1:5: +1:17
-          StorageLive(_2);                 // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
--         StorageLive(_3);                 // scope 0 at $DIR/ref_deref_project.rs:+1:8: +1:14
--         _3 = (const 4_i32, const 5_i32); // scope 0 at $DIR/ref_deref_project.rs:+1:8: +1:14
--         _2 = &(_3.1: i32);               // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
-+         _4 = const _;                    // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
-+                                          // mir::Constant
-+                                          // + span: $DIR/ref_deref_project.rs:6:6: 6:17
-+                                          // + literal: Const { ty: &(i32, i32), val: Unevaluated(main, [], Some(promoted[0])) }
-+         _2 = &((*_4).1: i32);            // scope 0 at $DIR/ref_deref_project.rs:+1:6: +1:17
-          _1 = (*_2);                      // scope 0 at $DIR/ref_deref_project.rs:+1:5: +1:17
--         StorageDead(_3);                 // scope 0 at $DIR/ref_deref_project.rs:+1:17: +1:18
-          StorageDead(_2);                 // scope 0 at $DIR/ref_deref_project.rs:+1:17: +1:18
-          StorageDead(_1);                 // scope 0 at $DIR/ref_deref_project.rs:+1:17: +1:18
-          _0 = const ();                   // scope 0 at $DIR/ref_deref_project.rs:+0:11: +2:2
-          return;                          // scope 0 at $DIR/ref_deref_project.rs:+2:2: +2:2
-      }
-  }
-  
diff --git a/tests/mir-opt/const_prop/ref_deref_project.rs b/tests/mir-opt/const_prop/ref_deref_project.rs
index 2fdd4e15319..04fc7f8daa1 100644
--- a/tests/mir-opt/const_prop/ref_deref_project.rs
+++ b/tests/mir-opt/const_prop/ref_deref_project.rs
@@ -1,5 +1,4 @@
-// compile-flags: -Zmir-enable-passes=-SimplifyLocals-before-const-prop
-// EMIT_MIR ref_deref_project.main.PromoteTemps.diff
+// unit-test: ConstProp
 // EMIT_MIR ref_deref_project.main.ConstProp.diff
 
 fn main() {
diff --git a/tests/mir-opt/const_prop/scalar_literal_propagation.main.ConstProp.diff b/tests/mir-opt/const_prop/scalar_literal_propagation.main.ConstProp.diff
index d518eff04eb..e3f5b120a32 100644
--- a/tests/mir-opt/const_prop/scalar_literal_propagation.main.ConstProp.diff
+++ b/tests/mir-opt/const_prop/scalar_literal_propagation.main.ConstProp.diff
@@ -14,10 +14,7 @@
           StorageLive(_1);                 // scope 0 at $DIR/scalar_literal_propagation.rs:+1:9: +1:10
           _1 = const 1_u32;                // scope 0 at $DIR/scalar_literal_propagation.rs:+1:13: +1:14
           StorageLive(_2);                 // scope 1 at $DIR/scalar_literal_propagation.rs:+2:5: +2:15
-          StorageLive(_3);                 // scope 1 at $DIR/scalar_literal_propagation.rs:+2:13: +2:14
--         _3 = _1;                         // scope 1 at $DIR/scalar_literal_propagation.rs:+2:13: +2:14
--         _2 = consume(move _3) -> bb1;    // scope 1 at $DIR/scalar_literal_propagation.rs:+2:5: +2:15
-+         _3 = const 1_u32;                // scope 1 at $DIR/scalar_literal_propagation.rs:+2:13: +2:14
+-         _2 = consume(_1) -> bb1;         // scope 1 at $DIR/scalar_literal_propagation.rs:+2:5: +2:15
 +         _2 = consume(const 1_u32) -> bb1; // scope 1 at $DIR/scalar_literal_propagation.rs:+2:5: +2:15
                                            // mir::Constant
                                            // + span: $DIR/scalar_literal_propagation.rs:4:5: 4:12
@@ -25,9 +22,7 @@
       }
   
       bb1: {
-          StorageDead(_3);                 // scope 1 at $DIR/scalar_literal_propagation.rs:+2:14: +2:15
           StorageDead(_2);                 // scope 1 at $DIR/scalar_literal_propagation.rs:+2:15: +2:16
-          StorageDead(_1);                 // scope 0 at $DIR/scalar_literal_propagation.rs:+3:1: +3:2
           return;                          // scope 0 at $DIR/scalar_literal_propagation.rs:+3:2: +3:2
       }
   }
diff --git a/tests/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff b/tests/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
index 9017fd18e48..b99b83b0cba 100644
--- a/tests/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.ConstProp.32bit.diff
@@ -20,7 +20,7 @@
           StorageLive(_4);                 // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
           _9 = const _;                    // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
                                            // mir::Constant
-                                           // + span: $DIR/slice_len.rs:6:6: 6:19
+                                           // + span: $DIR/slice_len.rs:7:6: 7:19
                                            // + literal: Const { ty: &[u32; 3], val: Unevaluated(main, [], Some(promoted[0])) }
           _4 = _9;                         // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
           _3 = _4;                         // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
@@ -33,7 +33,7 @@
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
 +         _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
 +         _8 = const true;                 // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
       }
   
       bb1: {
@@ -43,7 +43,7 @@
           StorageDead(_4);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
           StorageDead(_2);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
           StorageDead(_1);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
-          nop;                             // scope 0 at $DIR/slice_len.rs:+0:11: +2:2
+          _0 = const ();                   // scope 0 at $DIR/slice_len.rs:+0:11: +2:2
           return;                          // scope 0 at $DIR/slice_len.rs:+2:2: +2:2
       }
   }
diff --git a/tests/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff b/tests/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
index 9017fd18e48..b99b83b0cba 100644
--- a/tests/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.ConstProp.64bit.diff
@@ -20,7 +20,7 @@
           StorageLive(_4);                 // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
           _9 = const _;                    // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
                                            // mir::Constant
-                                           // + span: $DIR/slice_len.rs:6:6: 6:19
+                                           // + span: $DIR/slice_len.rs:7:6: 7:19
                                            // + literal: Const { ty: &[u32; 3], val: Unevaluated(main, [], Some(promoted[0])) }
           _4 = _9;                         // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
           _3 = _4;                         // scope 0 at $DIR/slice_len.rs:+1:6: +1:19
@@ -33,7 +33,7 @@
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
 +         _7 = const 3_usize;              // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
 +         _8 = const true;                 // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1; // scope 0 at $DIR/slice_len.rs:+1:5: +1:33
       }
   
       bb1: {
@@ -43,7 +43,7 @@
           StorageDead(_4);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
           StorageDead(_2);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
           StorageDead(_1);                 // scope 0 at $DIR/slice_len.rs:+1:33: +1:34
-          nop;                             // scope 0 at $DIR/slice_len.rs:+0:11: +2:2
+          _0 = const ();                   // scope 0 at $DIR/slice_len.rs:+0:11: +2:2
           return;                          // scope 0 at $DIR/slice_len.rs:+2:2: +2:2
       }
   }
diff --git a/tests/mir-opt/const_prop/slice_len.rs b/tests/mir-opt/const_prop/slice_len.rs
index eaaf34b960e..8183def0c63 100644
--- a/tests/mir-opt/const_prop/slice_len.rs
+++ b/tests/mir-opt/const_prop/slice_len.rs
@@ -1,4 +1,5 @@
-// compile-flags: -Zmir-enable-passes=-SimplifyLocals-before-const-prop
+// unit-test: ConstProp
+// compile-flags: -Zmir-enable-passes=+InstCombine
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 
 // EMIT_MIR slice_len.main.ConstProp.diff
diff --git a/tests/mir-opt/const_prop_miscompile.bar.ConstProp.diff b/tests/mir-opt/const_prop_miscompile.bar.ConstProp.diff
index ea9fec0aa15..b6b542fb794 100644
--- a/tests/mir-opt/const_prop_miscompile.bar.ConstProp.diff
+++ b/tests/mir-opt/const_prop_miscompile.bar.ConstProp.diff
@@ -4,15 +4,16 @@
   fn bar() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/const_prop_miscompile.rs:+0:10: +0:10
       let mut _1: (i32,);                  // in scope 0 at $DIR/const_prop_miscompile.rs:+1:9: +1:14
-      let mut _2: *mut i32;                // in scope 0 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
-      let mut _4: i32;                     // in scope 0 at $DIR/const_prop_miscompile.rs:+5:13: +5:20
+      let _2: ();                          // in scope 0 at $DIR/const_prop_miscompile.rs:+2:5: +4:6
+      let mut _3: *mut i32;                // in scope 0 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
+      let mut _5: i32;                     // in scope 0 at $DIR/const_prop_miscompile.rs:+5:13: +5:20
       scope 1 {
           debug v => _1;                   // in scope 1 at $DIR/const_prop_miscompile.rs:+1:9: +1:14
-          let _3: bool;                    // in scope 1 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
+          let _4: bool;                    // in scope 1 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
           scope 2 {
           }
           scope 3 {
-              debug y => _3;               // in scope 3 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
+              debug y => _4;               // in scope 3 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
           }
       }
   
@@ -20,16 +21,20 @@
           StorageLive(_1);                 // scope 0 at $DIR/const_prop_miscompile.rs:+1:9: +1:14
           Deinit(_1);                      // scope 0 at $DIR/const_prop_miscompile.rs:+1:17: +1:21
           (_1.0: i32) = const 1_i32;       // scope 0 at $DIR/const_prop_miscompile.rs:+1:17: +1:21
-          StorageLive(_2);                 // scope 2 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
-          _2 = &raw mut (_1.0: i32);       // scope 2 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
-          (*_2) = const 5_i32;             // scope 2 at $DIR/const_prop_miscompile.rs:+3:9: +3:26
-          StorageDead(_2);                 // scope 2 at $DIR/const_prop_miscompile.rs:+3:26: +3:27
-          StorageLive(_3);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
-          StorageLive(_4);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:13: +5:20
-          _4 = (_1.0: i32);                // scope 1 at $DIR/const_prop_miscompile.rs:+5:15: +5:18
-          _3 = Eq(move _4, const 5_i32);   // scope 1 at $DIR/const_prop_miscompile.rs:+5:13: +5:25
-          StorageDead(_4);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:24: +5:25
-          StorageDead(_3);                 // scope 1 at $DIR/const_prop_miscompile.rs:+6:1: +6:2
+          StorageLive(_2);                 // scope 1 at $DIR/const_prop_miscompile.rs:+2:5: +4:6
+          StorageLive(_3);                 // scope 2 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
+          _3 = &raw mut (_1.0: i32);       // scope 2 at $DIR/const_prop_miscompile.rs:+3:10: +3:22
+          (*_3) = const 5_i32;             // scope 2 at $DIR/const_prop_miscompile.rs:+3:9: +3:26
+          StorageDead(_3);                 // scope 2 at $DIR/const_prop_miscompile.rs:+3:26: +3:27
+          _2 = const ();                   // scope 2 at $DIR/const_prop_miscompile.rs:+2:5: +4:6
+          StorageDead(_2);                 // scope 1 at $DIR/const_prop_miscompile.rs:+4:5: +4:6
+          StorageLive(_4);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:9: +5:10
+          StorageLive(_5);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:13: +5:20
+          _5 = (_1.0: i32);                // scope 1 at $DIR/const_prop_miscompile.rs:+5:15: +5:18
+          _4 = Eq(move _5, const 5_i32);   // scope 1 at $DIR/const_prop_miscompile.rs:+5:13: +5:25
+          StorageDead(_5);                 // scope 1 at $DIR/const_prop_miscompile.rs:+5:24: +5:25
+          _0 = const ();                   // scope 0 at $DIR/const_prop_miscompile.rs:+0:10: +6:2
+          StorageDead(_4);                 // scope 1 at $DIR/const_prop_miscompile.rs:+6:1: +6:2
           StorageDead(_1);                 // scope 0 at $DIR/const_prop_miscompile.rs:+6:1: +6:2
           return;                          // scope 0 at $DIR/const_prop_miscompile.rs:+6:2: +6:2
       }
diff --git a/tests/mir-opt/const_prop_miscompile.foo.ConstProp.diff b/tests/mir-opt/const_prop_miscompile.foo.ConstProp.diff
index 043f4047417..e43735fd9e1 100644
--- a/tests/mir-opt/const_prop_miscompile.foo.ConstProp.diff
+++ b/tests/mir-opt/const_prop_miscompile.foo.ConstProp.diff
@@ -27,6 +27,7 @@
           _4 = (_1.0: i32);                // scope 1 at $DIR/const_prop_miscompile.rs:+3:15: +3:18
           _3 = Eq(move _4, const 5_i32);   // scope 1 at $DIR/const_prop_miscompile.rs:+3:13: +3:25
           StorageDead(_4);                 // scope 1 at $DIR/const_prop_miscompile.rs:+3:24: +3:25
+          _0 = const ();                   // scope 0 at $DIR/const_prop_miscompile.rs:+0:10: +4:2
           StorageDead(_3);                 // scope 1 at $DIR/const_prop_miscompile.rs:+4:1: +4:2
           StorageDead(_1);                 // scope 0 at $DIR/const_prop_miscompile.rs:+4:1: +4:2
           return;                          // scope 0 at $DIR/const_prop_miscompile.rs:+4:2: +4:2
diff --git a/tests/mir-opt/const_prop_miscompile.rs b/tests/mir-opt/const_prop_miscompile.rs
index bc54556b349..dbbe5ee0840 100644
--- a/tests/mir-opt/const_prop_miscompile.rs
+++ b/tests/mir-opt/const_prop_miscompile.rs
@@ -1,3 +1,4 @@
+// unit-test: ConstProp
 #![feature(raw_ref_op)]
 
 // EMIT_MIR const_prop_miscompile.foo.ConstProp.diff
diff --git a/tests/mir-opt/copy-prop/borrowed_local.f.CopyProp.diff b/tests/mir-opt/copy-prop/borrowed_local.f.CopyProp.diff
new file mode 100644
index 00000000000..b183865a9bc
--- /dev/null
+++ b/tests/mir-opt/copy-prop/borrowed_local.f.CopyProp.diff
@@ -0,0 +1,34 @@
+- // MIR for `f` before CopyProp
++ // MIR for `f` after CopyProp
+  
+  fn f() -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/borrowed_local.rs:+0:11: +0:15
+      let mut _1: u8;                      // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _2: &u8;                     // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _3: u8;                      // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _4: &u8;                     // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+  
+      bb0: {
+          _1 = const 5_u8;                 // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _2 = &_1;                        // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _3 = _1;                         // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _4 = &_3;                        // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _0 = cmp_ref(_2, _4) -> bb1;     // scope 0 at $DIR/borrowed_local.rs:+8:13: +8:45
+                                           // mir::Constant
+                                           // + span: $DIR/borrowed_local.rs:23:29: 23:36
+                                           // + literal: Const { ty: for<'a, 'b> fn(&'a u8, &'b u8) -> bool {cmp_ref}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+-         _0 = opaque::<u8>(_3) -> bb2;    // scope 0 at $DIR/borrowed_local.rs:+12:13: +12:38
++         _0 = opaque::<u8>(_1) -> bb2;    // scope 0 at $DIR/borrowed_local.rs:+12:13: +12:38
+                                           // mir::Constant
+                                           // + span: $DIR/borrowed_local.rs:27:28: 27:34
+                                           // + literal: Const { ty: fn(u8) -> bool {opaque::<u8>}, val: Value(<ZST>) }
+      }
+  
+      bb2: {
+          return;                          // scope 0 at $DIR/borrowed_local.rs:+15:13: +15:21
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/borrowed_local.rs b/tests/mir-opt/copy-prop/borrowed_local.rs
new file mode 100644
index 00000000000..c4b980e2b35
--- /dev/null
+++ b/tests/mir-opt/copy-prop/borrowed_local.rs
@@ -0,0 +1,39 @@
+// unit-test: CopyProp
+
+#![feature(custom_mir, core_intrinsics)]
+#![allow(unused_assignments)]
+extern crate core;
+use core::intrinsics::mir::*;
+
+fn opaque(_: impl Sized) -> bool { true }
+
+fn cmp_ref(a: &u8, b: &u8) -> bool {
+    std::ptr::eq(a as *const u8, b as *const u8)
+}
+
+#[custom_mir(dialect = "analysis", phase = "post-cleanup")]
+fn f() -> bool {
+    mir!(
+        {
+            let a = 5_u8;
+            let r1 = &a;
+            let b = a;
+            // We cannot propagate the place `a`.
+            let r2 = &b;
+            Call(RET, next, cmp_ref(r1, r2))
+        }
+        next = {
+            // But we can propagate the value `a`.
+            Call(RET, ret, opaque(b))
+        }
+        ret = {
+            Return()
+        }
+    )
+}
+
+fn main() {
+    assert!(!f());
+}
+
+// EMIT_MIR borrowed_local.f.CopyProp.diff
diff --git a/tests/mir-opt/copy-prop/branch.foo.CopyProp.diff b/tests/mir-opt/copy-prop/branch.foo.CopyProp.diff
new file mode 100644
index 00000000000..8b116532d9f
--- /dev/null
+++ b/tests/mir-opt/copy-prop/branch.foo.CopyProp.diff
@@ -0,0 +1,65 @@
+- // MIR for `foo` before CopyProp
++ // MIR for `foo` after CopyProp
+  
+  fn foo() -> i32 {
+      let mut _0: i32;                     // return place in scope 0 at $DIR/branch.rs:+0:13: +0:16
+      let _1: i32;                         // in scope 0 at $DIR/branch.rs:+1:9: +1:10
+      let mut _3: bool;                    // in scope 0 at $DIR/branch.rs:+3:16: +3:22
+      let _4: i32;                         // in scope 0 at $DIR/branch.rs:+6:9: +6:14
+      scope 1 {
+          debug x => _1;                   // in scope 1 at $DIR/branch.rs:+1:9: +1:10
+          let _2: i32;                     // in scope 1 at $DIR/branch.rs:+3:9: +3:10
+          scope 2 {
+              debug y => _2;               // in scope 2 at $DIR/branch.rs:+3:9: +3:10
+          }
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/branch.rs:+1:9: +1:10
+          _1 = val() -> bb1;               // scope 0 at $DIR/branch.rs:+1:13: +1:18
+                                           // mir::Constant
+                                           // + span: $DIR/branch.rs:13:13: 13:16
+                                           // + literal: Const { ty: fn() -> i32 {val}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageLive(_2);                 // scope 1 at $DIR/branch.rs:+3:9: +3:10
+          StorageLive(_3);                 // scope 1 at $DIR/branch.rs:+3:16: +3:22
+          _3 = cond() -> bb2;              // scope 1 at $DIR/branch.rs:+3:16: +3:22
+                                           // mir::Constant
+                                           // + span: $DIR/branch.rs:15:16: 15:20
+                                           // + literal: Const { ty: fn() -> bool {cond}, val: Value(<ZST>) }
+      }
+  
+      bb2: {
+          switchInt(move _3) -> [0: bb4, otherwise: bb3]; // scope 1 at $DIR/branch.rs:+3:16: +3:22
+      }
+  
+      bb3: {
+          _2 = _1;                         // scope 1 at $DIR/branch.rs:+4:9: +4:10
+          goto -> bb6;                     // scope 1 at $DIR/branch.rs:+3:13: +8:6
+      }
+  
+      bb4: {
+          StorageLive(_4);                 // scope 1 at $DIR/branch.rs:+6:9: +6:14
+          _4 = val() -> bb5;               // scope 1 at $DIR/branch.rs:+6:9: +6:14
+                                           // mir::Constant
+                                           // + span: $DIR/branch.rs:18:9: 18:12
+                                           // + literal: Const { ty: fn() -> i32 {val}, val: Value(<ZST>) }
+      }
+  
+      bb5: {
+          StorageDead(_4);                 // scope 1 at $DIR/branch.rs:+6:14: +6:15
+          _2 = _1;                         // scope 1 at $DIR/branch.rs:+7:9: +7:10
+          goto -> bb6;                     // scope 1 at $DIR/branch.rs:+3:13: +8:6
+      }
+  
+      bb6: {
+          StorageDead(_3);                 // scope 1 at $DIR/branch.rs:+8:5: +8:6
+          _0 = _2;                         // scope 2 at $DIR/branch.rs:+10:5: +10:6
+          StorageDead(_2);                 // scope 1 at $DIR/branch.rs:+11:1: +11:2
+          StorageDead(_1);                 // scope 0 at $DIR/branch.rs:+11:1: +11:2
+          return;                          // scope 0 at $DIR/branch.rs:+11:2: +11:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/branch.rs b/tests/mir-opt/copy-prop/branch.rs
new file mode 100644
index 00000000000..50b1e00fad4
--- /dev/null
+++ b/tests/mir-opt/copy-prop/branch.rs
@@ -0,0 +1,27 @@
+//! Tests that we bail out when there are multiple assignments to the same local.
+// unit-test: CopyProp
+fn val() -> i32 {
+    1
+}
+
+fn cond() -> bool {
+    true
+}
+
+// EMIT_MIR branch.foo.CopyProp.diff
+fn foo() -> i32 {
+    let x = val();
+
+    let y = if cond() {
+        x
+    } else {
+        val();
+        x
+    };
+
+    y
+}
+
+fn main() {
+    foo();
+}
diff --git a/tests/mir-opt/copy-prop/copy_propagation_arg.arg_src.CopyProp.diff b/tests/mir-opt/copy-prop/copy_propagation_arg.arg_src.CopyProp.diff
new file mode 100644
index 00000000000..69acebf7642
--- /dev/null
+++ b/tests/mir-opt/copy-prop/copy_propagation_arg.arg_src.CopyProp.diff
@@ -0,0 +1,21 @@
+- // MIR for `arg_src` before CopyProp
++ // MIR for `arg_src` after CopyProp
+  
+  fn arg_src(_1: i32) -> i32 {
+      debug x => _1;                       // in scope 0 at $DIR/copy_propagation_arg.rs:+0:12: +0:17
+      let mut _0: i32;                     // return place in scope 0 at $DIR/copy_propagation_arg.rs:+0:27: +0:30
+      let _2: i32;                         // in scope 0 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
+      scope 1 {
+          debug y => _2;                   // in scope 1 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
+      }
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
+          _2 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+1:13: +1:14
+          _1 = const 123_i32;              // scope 1 at $DIR/copy_propagation_arg.rs:+2:5: +2:12
+          _0 = _2;                         // scope 1 at $DIR/copy_propagation_arg.rs:+3:5: +3:6
+          StorageDead(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+4:1: +4:2
+          return;                          // scope 0 at $DIR/copy_propagation_arg.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/copy_propagation_arg.bar.CopyProp.diff b/tests/mir-opt/copy-prop/copy_propagation_arg.bar.CopyProp.diff
new file mode 100644
index 00000000000..ac4e9a2bfa7
--- /dev/null
+++ b/tests/mir-opt/copy-prop/copy_propagation_arg.bar.CopyProp.diff
@@ -0,0 +1,28 @@
+- // MIR for `bar` before CopyProp
++ // MIR for `bar` after CopyProp
+  
+  fn bar(_1: u8) -> () {
+      debug x => _1;                       // in scope 0 at $DIR/copy_propagation_arg.rs:+0:8: +0:13
+      let mut _0: ();                      // return place in scope 0 at $DIR/copy_propagation_arg.rs:+0:19: +0:19
+      let _2: u8;                          // in scope 0 at $DIR/copy_propagation_arg.rs:+1:5: +1:13
+      let mut _3: u8;                      // in scope 0 at $DIR/copy_propagation_arg.rs:+1:11: +1:12
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:5: +1:13
+          StorageLive(_3);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:11: +1:12
+          _3 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+1:11: +1:12
+          _2 = dummy(move _3) -> bb1;      // scope 0 at $DIR/copy_propagation_arg.rs:+1:5: +1:13
+                                           // mir::Constant
+                                           // + span: $DIR/copy_propagation_arg.rs:16:5: 16:10
+                                           // + literal: Const { ty: fn(u8) -> u8 {dummy}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageDead(_3);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:12: +1:13
+          StorageDead(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:13: +1:14
+          _1 = const 5_u8;                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:5: +2:10
+          _0 = const ();                   // scope 0 at $DIR/copy_propagation_arg.rs:+0:19: +3:2
+          return;                          // scope 0 at $DIR/copy_propagation_arg.rs:+3:2: +3:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/copy_propagation_arg.baz.CopyProp.diff b/tests/mir-opt/copy-prop/copy_propagation_arg.baz.CopyProp.diff
new file mode 100644
index 00000000000..7ab6ebb7d53
--- /dev/null
+++ b/tests/mir-opt/copy-prop/copy_propagation_arg.baz.CopyProp.diff
@@ -0,0 +1,18 @@
+- // MIR for `baz` before CopyProp
++ // MIR for `baz` after CopyProp
+  
+  fn baz(_1: i32) -> i32 {
+      debug x => _1;                       // in scope 0 at $DIR/copy_propagation_arg.rs:+0:8: +0:13
+      let mut _0: i32;                     // return place in scope 0 at $DIR/copy_propagation_arg.rs:+0:23: +0:26
+      let mut _2: i32;                     // in scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:10
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:10
+          _2 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:10
+          _1 = move _2;                    // scope 0 at $DIR/copy_propagation_arg.rs:+2:5: +2:10
+          StorageDead(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:10
+          _0 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+3:5: +3:6
+          return;                          // scope 0 at $DIR/copy_propagation_arg.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/copy_propagation_arg.foo.CopyProp.diff b/tests/mir-opt/copy-prop/copy_propagation_arg.foo.CopyProp.diff
new file mode 100644
index 00000000000..0a3e985e7c2
--- /dev/null
+++ b/tests/mir-opt/copy-prop/copy_propagation_arg.foo.CopyProp.diff
@@ -0,0 +1,28 @@
+- // MIR for `foo` before CopyProp
++ // MIR for `foo` after CopyProp
+  
+  fn foo(_1: u8) -> () {
+      debug x => _1;                       // in scope 0 at $DIR/copy_propagation_arg.rs:+0:8: +0:13
+      let mut _0: ();                      // return place in scope 0 at $DIR/copy_propagation_arg.rs:+0:19: +0:19
+      let mut _2: u8;                      // in scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:17
+      let mut _3: u8;                      // in scope 0 at $DIR/copy_propagation_arg.rs:+2:15: +2:16
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:17
+          StorageLive(_3);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:15: +2:16
+          _3 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+2:15: +2:16
+          _2 = dummy(move _3) -> bb1;      // scope 0 at $DIR/copy_propagation_arg.rs:+2:9: +2:17
+                                           // mir::Constant
+                                           // + span: $DIR/copy_propagation_arg.rs:11:9: 11:14
+                                           // + literal: Const { ty: fn(u8) -> u8 {dummy}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageDead(_3);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:16: +2:17
+          _1 = move _2;                    // scope 0 at $DIR/copy_propagation_arg.rs:+2:5: +2:17
+          StorageDead(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+2:16: +2:17
+          _0 = const ();                   // scope 0 at $DIR/copy_propagation_arg.rs:+0:19: +3:2
+          return;                          // scope 0 at $DIR/copy_propagation_arg.rs:+3:2: +3:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/copy_propagation_arg.rs b/tests/mir-opt/copy-prop/copy_propagation_arg.rs
new file mode 100644
index 00000000000..cc98985f1fd
--- /dev/null
+++ b/tests/mir-opt/copy-prop/copy_propagation_arg.rs
@@ -0,0 +1,40 @@
+// Check that CopyProp does not propagate an assignment to a function argument
+// (doing so can break usages of the original argument value)
+// unit-test: CopyProp
+fn dummy(x: u8) -> u8 {
+    x
+}
+
+// EMIT_MIR copy_propagation_arg.foo.CopyProp.diff
+fn foo(mut x: u8) {
+    // calling `dummy` to make a use of `x` that copyprop cannot eliminate
+    x = dummy(x); // this will assign a local to `x`
+}
+
+// EMIT_MIR copy_propagation_arg.bar.CopyProp.diff
+fn bar(mut x: u8) {
+    dummy(x);
+    x = 5;
+}
+
+// EMIT_MIR copy_propagation_arg.baz.CopyProp.diff
+fn baz(mut x: i32) -> i32 {
+    // self-assignment to a function argument should be eliminated
+    x = x;
+    x
+}
+
+// EMIT_MIR copy_propagation_arg.arg_src.CopyProp.diff
+fn arg_src(mut x: i32) -> i32 {
+    let y = x;
+    x = 123; // Don't propagate this assignment to `y`
+    y
+}
+
+fn main() {
+    // Make sure the function actually gets instantiated.
+    foo(0);
+    bar(0);
+    baz(0);
+    arg_src(0);
+}
diff --git a/tests/mir-opt/copy-prop/cycle.main.CopyProp.diff b/tests/mir-opt/copy-prop/cycle.main.CopyProp.diff
new file mode 100644
index 00000000000..bc5083e1ad0
--- /dev/null
+++ b/tests/mir-opt/copy-prop/cycle.main.CopyProp.diff
@@ -0,0 +1,60 @@
+- // MIR for `main` before CopyProp
++ // MIR for `main` after CopyProp
+  
+  fn main() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/cycle.rs:+0:11: +0:11
+      let mut _1: i32;                     // in scope 0 at $DIR/cycle.rs:+1:9: +1:14
+      let mut _4: i32;                     // in scope 0 at $DIR/cycle.rs:+4:9: +4:10
+      let _5: ();                          // in scope 0 at $DIR/cycle.rs:+6:5: +6:12
+      let mut _6: i32;                     // in scope 0 at $DIR/cycle.rs:+6:10: +6:11
+      scope 1 {
+          debug x => _1;                   // in scope 1 at $DIR/cycle.rs:+1:9: +1:14
+          let _2: i32;                     // in scope 1 at $DIR/cycle.rs:+2:9: +2:10
+          scope 2 {
+              debug y => _2;               // in scope 2 at $DIR/cycle.rs:+2:9: +2:10
+              let _3: i32;                 // in scope 2 at $DIR/cycle.rs:+3:9: +3:10
+              scope 3 {
+-                 debug z => _3;           // in scope 3 at $DIR/cycle.rs:+3:9: +3:10
++                 debug z => _2;           // in scope 3 at $DIR/cycle.rs:+3:9: +3:10
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/cycle.rs:+1:9: +1:14
+          _1 = val() -> bb1;               // scope 0 at $DIR/cycle.rs:+1:17: +1:22
+                                           // mir::Constant
+                                           // + span: $DIR/cycle.rs:9:17: 9:20
+                                           // + literal: Const { ty: fn() -> i32 {val}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageLive(_2);                 // scope 1 at $DIR/cycle.rs:+2:9: +2:10
+          _2 = _1;                         // scope 1 at $DIR/cycle.rs:+2:13: +2:14
+-         StorageLive(_3);                 // scope 2 at $DIR/cycle.rs:+3:9: +3:10
+-         _3 = _2;                         // scope 2 at $DIR/cycle.rs:+3:13: +3:14
+-         StorageLive(_4);                 // scope 3 at $DIR/cycle.rs:+4:9: +4:10
+-         _4 = _3;                         // scope 3 at $DIR/cycle.rs:+4:9: +4:10
+-         _1 = move _4;                    // scope 3 at $DIR/cycle.rs:+4:5: +4:10
+-         StorageDead(_4);                 // scope 3 at $DIR/cycle.rs:+4:9: +4:10
++         _1 = _2;                         // scope 3 at $DIR/cycle.rs:+4:5: +4:10
+          StorageLive(_5);                 // scope 3 at $DIR/cycle.rs:+6:5: +6:12
+          StorageLive(_6);                 // scope 3 at $DIR/cycle.rs:+6:10: +6:11
+          _6 = _1;                         // scope 3 at $DIR/cycle.rs:+6:10: +6:11
+          _5 = std::mem::drop::<i32>(move _6) -> bb2; // scope 3 at $DIR/cycle.rs:+6:5: +6:12
+                                           // mir::Constant
+                                           // + span: $DIR/cycle.rs:14:5: 14:9
+                                           // + literal: Const { ty: fn(i32) {std::mem::drop::<i32>}, val: Value(<ZST>) }
+      }
+  
+      bb2: {
+          StorageDead(_6);                 // scope 3 at $DIR/cycle.rs:+6:11: +6:12
+          StorageDead(_5);                 // scope 3 at $DIR/cycle.rs:+6:12: +6:13
+          _0 = const ();                   // scope 0 at $DIR/cycle.rs:+0:11: +7:2
+-         StorageDead(_3);                 // scope 2 at $DIR/cycle.rs:+7:1: +7:2
+-         StorageDead(_2);                 // scope 1 at $DIR/cycle.rs:+7:1: +7:2
+          StorageDead(_1);                 // scope 0 at $DIR/cycle.rs:+7:1: +7:2
+          return;                          // scope 0 at $DIR/cycle.rs:+7:2: +7:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/cycle.rs b/tests/mir-opt/copy-prop/cycle.rs
new file mode 100644
index 00000000000..b74c397269d
--- /dev/null
+++ b/tests/mir-opt/copy-prop/cycle.rs
@@ -0,0 +1,15 @@
+//! Tests that cyclic assignments don't hang CopyProp, and result in reasonable code.
+// unit-test: CopyProp
+fn val() -> i32 {
+    1
+}
+
+// EMIT_MIR cycle.main.CopyProp.diff
+fn main() {
+    let mut x = val();
+    let y = x;
+    let z = y;
+    x = z;
+
+    drop(x);
+}
diff --git a/tests/mir-opt/copy-prop/dead_stores_79191.f.CopyProp.after.mir b/tests/mir-opt/copy-prop/dead_stores_79191.f.CopyProp.after.mir
new file mode 100644
index 00000000000..918817da56c
--- /dev/null
+++ b/tests/mir-opt/copy-prop/dead_stores_79191.f.CopyProp.after.mir
@@ -0,0 +1,30 @@
+// MIR for `f` after CopyProp
+
+fn f(_1: usize) -> usize {
+    debug a => _1;                       // in scope 0 at $DIR/dead_stores_79191.rs:+0:6: +0:11
+    let mut _0: usize;                   // return place in scope 0 at $DIR/dead_stores_79191.rs:+0:23: +0:28
+    let _2: usize;                       // in scope 0 at $DIR/dead_stores_79191.rs:+1:9: +1:10
+    let mut _3: usize;                   // in scope 0 at $DIR/dead_stores_79191.rs:+3:9: +3:10
+    let mut _4: usize;                   // in scope 0 at $DIR/dead_stores_79191.rs:+4:8: +4:9
+    scope 1 {
+        debug b => _2;                   // in scope 1 at $DIR/dead_stores_79191.rs:+1:9: +1:10
+    }
+
+    bb0: {
+        StorageLive(_2);                 // scope 0 at $DIR/dead_stores_79191.rs:+1:9: +1:10
+        _2 = _1;                         // scope 0 at $DIR/dead_stores_79191.rs:+1:13: +1:14
+        _1 = const 5_usize;              // scope 1 at $DIR/dead_stores_79191.rs:+2:5: +2:10
+        _1 = _2;                         // scope 1 at $DIR/dead_stores_79191.rs:+3:5: +3:10
+        StorageLive(_4);                 // scope 1 at $DIR/dead_stores_79191.rs:+4:8: +4:9
+        _4 = _1;                         // scope 1 at $DIR/dead_stores_79191.rs:+4:8: +4:9
+        _0 = id::<usize>(move _4) -> bb1; // scope 1 at $DIR/dead_stores_79191.rs:+4:5: +4:10
+                                         // mir::Constant
+                                         // + span: $DIR/dead_stores_79191.rs:12:5: 12:7
+                                         // + literal: Const { ty: fn(usize) -> usize {id::<usize>}, val: Value(<ZST>) }
+    }
+
+    bb1: {
+        StorageDead(_4);                 // scope 1 at $DIR/dead_stores_79191.rs:+4:9: +4:10
+        return;                          // scope 0 at $DIR/dead_stores_79191.rs:+5:2: +5:2
+    }
+}
diff --git a/tests/mir-opt/copy-prop/dead_stores_79191.rs b/tests/mir-opt/copy-prop/dead_stores_79191.rs
new file mode 100644
index 00000000000..e3493b8b7a1
--- /dev/null
+++ b/tests/mir-opt/copy-prop/dead_stores_79191.rs
@@ -0,0 +1,17 @@
+// unit-test: CopyProp
+
+fn id<T>(x: T) -> T {
+    x
+}
+
+// EMIT_MIR dead_stores_79191.f.CopyProp.after.mir
+fn f(mut a: usize) -> usize {
+    let b = a;
+    a = 5;
+    a = b;
+    id(a)
+}
+
+fn main() {
+    f(0);
+}
diff --git a/tests/mir-opt/copy-prop/dead_stores_better.f.CopyProp.after.mir b/tests/mir-opt/copy-prop/dead_stores_better.f.CopyProp.after.mir
new file mode 100644
index 00000000000..cf21fadd437
--- /dev/null
+++ b/tests/mir-opt/copy-prop/dead_stores_better.f.CopyProp.after.mir
@@ -0,0 +1,30 @@
+// MIR for `f` after CopyProp
+
+fn f(_1: usize) -> usize {
+    debug a => _1;                       // in scope 0 at $DIR/dead_stores_better.rs:+0:10: +0:15
+    let mut _0: usize;                   // return place in scope 0 at $DIR/dead_stores_better.rs:+0:27: +0:32
+    let _2: usize;                       // in scope 0 at $DIR/dead_stores_better.rs:+1:9: +1:10
+    let mut _3: usize;                   // in scope 0 at $DIR/dead_stores_better.rs:+3:9: +3:10
+    let mut _4: usize;                   // in scope 0 at $DIR/dead_stores_better.rs:+4:8: +4:9
+    scope 1 {
+        debug b => _2;                   // in scope 1 at $DIR/dead_stores_better.rs:+1:9: +1:10
+    }
+
+    bb0: {
+        StorageLive(_2);                 // scope 0 at $DIR/dead_stores_better.rs:+1:9: +1:10
+        _2 = _1;                         // scope 0 at $DIR/dead_stores_better.rs:+1:13: +1:14
+        _1 = const 5_usize;              // scope 1 at $DIR/dead_stores_better.rs:+2:5: +2:10
+        _1 = _2;                         // scope 1 at $DIR/dead_stores_better.rs:+3:5: +3:10
+        StorageLive(_4);                 // scope 1 at $DIR/dead_stores_better.rs:+4:8: +4:9
+        _4 = _1;                         // scope 1 at $DIR/dead_stores_better.rs:+4:8: +4:9
+        _0 = id::<usize>(move _4) -> bb1; // scope 1 at $DIR/dead_stores_better.rs:+4:5: +4:10
+                                         // mir::Constant
+                                         // + span: $DIR/dead_stores_better.rs:16:5: 16:7
+                                         // + literal: Const { ty: fn(usize) -> usize {id::<usize>}, val: Value(<ZST>) }
+    }
+
+    bb1: {
+        StorageDead(_4);                 // scope 1 at $DIR/dead_stores_better.rs:+4:9: +4:10
+        return;                          // scope 0 at $DIR/dead_stores_better.rs:+5:2: +5:2
+    }
+}
diff --git a/tests/mir-opt/copy-prop/dead_stores_better.rs b/tests/mir-opt/copy-prop/dead_stores_better.rs
new file mode 100644
index 00000000000..8465b3c9853
--- /dev/null
+++ b/tests/mir-opt/copy-prop/dead_stores_better.rs
@@ -0,0 +1,21 @@
+// This is a copy of the `dead_stores_79191` test, except that we turn on DSE. This demonstrates
+// that that pass enables this one to do more optimizations.
+
+// unit-test: CopyProp
+// compile-flags: -Zmir-enable-passes=+DeadStoreElimination
+
+fn id<T>(x: T) -> T {
+    x
+}
+
+// EMIT_MIR dead_stores_better.f.CopyProp.after.mir
+pub fn f(mut a: usize) -> usize {
+    let b = a;
+    a = 5;
+    a = b;
+    id(a)
+}
+
+fn main() {
+    f(0);
+}
diff --git a/tests/mir-opt/copy-prop/move_arg.f.CopyProp.diff b/tests/mir-opt/copy-prop/move_arg.f.CopyProp.diff
new file mode 100644
index 00000000000..d76bf1cfe7e
--- /dev/null
+++ b/tests/mir-opt/copy-prop/move_arg.f.CopyProp.diff
@@ -0,0 +1,40 @@
+- // MIR for `f` before CopyProp
++ // MIR for `f` after CopyProp
+  
+  fn f(_1: T) -> () {
+      debug a => _1;                       // in scope 0 at $DIR/move_arg.rs:+0:19: +0:20
+      let mut _0: ();                      // return place in scope 0 at $DIR/move_arg.rs:+0:25: +0:25
+      let _2: T;                           // in scope 0 at $DIR/move_arg.rs:+1:9: +1:10
+      let _3: ();                          // in scope 0 at $DIR/move_arg.rs:+2:5: +2:12
+      let mut _4: T;                       // in scope 0 at $DIR/move_arg.rs:+2:7: +2:8
+      let mut _5: T;                       // in scope 0 at $DIR/move_arg.rs:+2:10: +2:11
+      scope 1 {
+-         debug b => _2;                   // in scope 1 at $DIR/move_arg.rs:+1:9: +1:10
++         debug b => _1;                   // in scope 1 at $DIR/move_arg.rs:+1:9: +1:10
+      }
+  
+      bb0: {
+-         StorageLive(_2);                 // scope 0 at $DIR/move_arg.rs:+1:9: +1:10
+-         _2 = _1;                         // scope 0 at $DIR/move_arg.rs:+1:13: +1:14
+          StorageLive(_3);                 // scope 1 at $DIR/move_arg.rs:+2:5: +2:12
+-         StorageLive(_4);                 // scope 1 at $DIR/move_arg.rs:+2:7: +2:8
+-         _4 = _1;                         // scope 1 at $DIR/move_arg.rs:+2:7: +2:8
+-         StorageLive(_5);                 // scope 1 at $DIR/move_arg.rs:+2:10: +2:11
+-         _5 = _2;                         // scope 1 at $DIR/move_arg.rs:+2:10: +2:11
+-         _3 = g::<T>(move _4, move _5) -> bb1; // scope 1 at $DIR/move_arg.rs:+2:5: +2:12
++         _3 = g::<T>(_1, _1) -> bb1;      // scope 1 at $DIR/move_arg.rs:+2:5: +2:12
+                                           // mir::Constant
+                                           // + span: $DIR/move_arg.rs:7:5: 7:6
+                                           // + literal: Const { ty: fn(T, T) {g::<T>}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+-         StorageDead(_5);                 // scope 1 at $DIR/move_arg.rs:+2:11: +2:12
+-         StorageDead(_4);                 // scope 1 at $DIR/move_arg.rs:+2:11: +2:12
+          StorageDead(_3);                 // scope 1 at $DIR/move_arg.rs:+2:12: +2:13
+          _0 = const ();                   // scope 0 at $DIR/move_arg.rs:+0:25: +3:2
+-         StorageDead(_2);                 // scope 0 at $DIR/move_arg.rs:+3:1: +3:2
+          return;                          // scope 0 at $DIR/move_arg.rs:+3:2: +3:2
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/move_arg.rs b/tests/mir-opt/copy-prop/move_arg.rs
new file mode 100644
index 00000000000..40ae1d8f466
--- /dev/null
+++ b/tests/mir-opt/copy-prop/move_arg.rs
@@ -0,0 +1,15 @@
+// Test that we do not move multiple times from the same local.
+// unit-test: CopyProp
+
+// EMIT_MIR move_arg.f.CopyProp.diff
+pub fn f<T: Copy>(a: T) {
+    let b = a;
+    g(a, b);
+}
+
+#[inline(never)]
+pub fn g<T: Copy>(_: T, _: T) {}
+
+fn main() {
+    f(5)
+}
diff --git a/tests/mir-opt/copy-prop/mutate_through_pointer.f.CopyProp.diff b/tests/mir-opt/copy-prop/mutate_through_pointer.f.CopyProp.diff
new file mode 100644
index 00000000000..61fdd6f8c05
--- /dev/null
+++ b/tests/mir-opt/copy-prop/mutate_through_pointer.f.CopyProp.diff
@@ -0,0 +1,19 @@
+- // MIR for `f` before CopyProp
++ // MIR for `f` after CopyProp
+  
+  fn f(_1: bool) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/mutate_through_pointer.rs:+0:18: +0:22
+      let mut _2: bool;                    // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _3: *const bool;             // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _4: *mut bool;               // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+  
+      bb0: {
+          _2 = _1;                         // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _3 = &raw const _2;              // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          _4 = &raw mut (*_3);             // scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+          (*_4) = const false;             // scope 0 at $DIR/mutate_through_pointer.rs:+5:9: +5:20
+          _0 = _1;                         // scope 0 at $DIR/mutate_through_pointer.rs:+6:9: +6:16
+          return;                          // scope 0 at $DIR/mutate_through_pointer.rs:+7:9: +7:17
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/mutate_through_pointer.rs b/tests/mir-opt/copy-prop/mutate_through_pointer.rs
new file mode 100644
index 00000000000..609e49d6bc9
--- /dev/null
+++ b/tests/mir-opt/copy-prop/mutate_through_pointer.rs
@@ -0,0 +1,22 @@
+#![feature(custom_mir, core_intrinsics)]
+#![allow(unused_assignments)]
+extern crate core;
+use core::intrinsics::mir::*;
+
+#[custom_mir(dialect = "analysis", phase = "post-cleanup")]
+fn f(c: bool) -> bool {
+    mir!({
+        let a = c;
+        let p = core::ptr::addr_of!(a);
+        let p2 = core::ptr::addr_of_mut!(*p);
+        *p2 = false;
+        RET = c;
+        Return()
+    })
+}
+
+fn main() {
+    assert_eq!(true, f(true));
+}
+
+// EMIT_MIR mutate_through_pointer.f.CopyProp.diff
diff --git a/tests/mir-opt/copy-prop/non_dominate.f.CopyProp.diff b/tests/mir-opt/copy-prop/non_dominate.f.CopyProp.diff
new file mode 100644
index 00000000000..9760fd3740f
--- /dev/null
+++ b/tests/mir-opt/copy-prop/non_dominate.f.CopyProp.diff
@@ -0,0 +1,29 @@
+- // MIR for `f` before CopyProp
++ // MIR for `f` after CopyProp
+  
+  fn f(_1: bool) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/non_dominate.rs:+0:18: +0:22
+      let mut _2: bool;                    // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+      let mut _3: bool;                    // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+  
+      bb0: {
+          goto -> bb1;                     // scope 0 at $DIR/non_dominate.rs:+4:11: +4:20
+      }
+  
+      bb1: {
+          _3 = _1;                         // scope 0 at $DIR/non_dominate.rs:+5:17: +5:22
+          switchInt(_3) -> [0: bb3, otherwise: bb2]; // scope 0 at $DIR/non_dominate.rs:+5:24: +5:58
+      }
+  
+      bb2: {
+          _2 = _3;                         // scope 0 at $DIR/non_dominate.rs:+8:17: +8:22
+          _1 = const false;                // scope 0 at $DIR/non_dominate.rs:+8:24: +8:33
+          goto -> bb1;                     // scope 0 at $DIR/non_dominate.rs:+8:35: +8:44
+      }
+  
+      bb3: {
+          _0 = _2;                         // scope 0 at $DIR/non_dominate.rs:+9:17: +9:24
+          return;                          // scope 0 at $DIR/non_dominate.rs:+9:26: +9:34
+      }
+  }
+  
diff --git a/tests/mir-opt/copy-prop/non_dominate.rs b/tests/mir-opt/copy-prop/non_dominate.rs
new file mode 100644
index 00000000000..c0ea838e1c8
--- /dev/null
+++ b/tests/mir-opt/copy-prop/non_dominate.rs
@@ -0,0 +1,26 @@
+// unit-test: CopyProp
+
+#![feature(custom_mir, core_intrinsics)]
+#![allow(unused_assignments)]
+extern crate core;
+use core::intrinsics::mir::*;
+
+#[custom_mir(dialect = "analysis", phase = "post-cleanup")]
+fn f(c: bool) -> bool {
+    mir!(
+        let a: bool;
+        let b: bool;
+        { Goto(bb1) }
+        bb1 = { b = c; match b { false => bb3, _ => bb2 }}
+        // This assignment to `a` does not dominate the use in `bb3`.
+        // It should not be replaced by `b`.
+        bb2 = { a = b; c = false; Goto(bb1) }
+        bb3 = { RET = a; Return() }
+    )
+}
+
+fn main() {
+    assert_eq!(true, f(true));
+}
+
+// EMIT_MIR non_dominate.f.CopyProp.diff
diff --git a/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff b/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
index 02aafd7acc4..6870d7d6c45 100644
--- a/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
+++ b/tests/mir-opt/dataflow-const-prop/inherit_overflow.main.DataflowConstProp.diff
@@ -20,19 +20,11 @@
           _1 = const u8::MAX;              // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
           StorageLive(_2);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
           _2 = const 1_u8;                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          StorageLive(_3);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          _3 = const u8::MAX;              // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          StorageLive(_4);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          _4 = const 1_u8;                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
           _5 = CheckedAdd(const u8::MAX, const 1_u8); // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
           assert(!move (_5.1: bool), "attempt to compute `{} + {}`, which would overflow", const u8::MAX, const 1_u8) -> bb1; // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
       }
   
       bb1: {
-          StorageDead(_4);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          StorageDead(_3);                 // scope 2 at $SRC_DIR/core/src/ops/arith.rs:LL:COL
-          StorageDead(_2);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
-          StorageDead(_1);                 // scope 0 at $DIR/inherit_overflow.rs:+3:13: +3:47
           return;                          // scope 0 at $DIR/inherit_overflow.rs:+4:2: +4:2
       }
   }
diff --git a/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir b/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir
index d7f66a6bf4d..1a7fb916e56 100644
--- a/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir
+++ b/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir
@@ -11,7 +11,7 @@ fn const_dividend(_1: i32) -> i32 {
     }
 
     bb1: {
-        _0 = Div(const 256_i32, move _1); // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
+        _0 = Div(const 256_i32, _1);     // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
         return;                          // scope 0 at $DIR/div_overflow.rs:+2:2: +2:2
     }
 }
diff --git a/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir b/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir
index 7b7ab197825..5526a194be5 100644
--- a/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir
+++ b/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir
@@ -5,7 +5,7 @@ fn const_divisor(_1: i32) -> i32 {
     let mut _0: i32;                     // return place in scope 0 at $DIR/div_overflow.rs:+0:33: +0:36
 
     bb0: {
-        _0 = Div(move _1, const 256_i32); // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
+        _0 = Div(_1, const 256_i32);     // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
         return;                          // scope 0 at $DIR/div_overflow.rs:+2:2: +2:2
     }
 }
diff --git a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff
index c1c2cde71ab..df9f8dcf1a4 100644
--- a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff
+++ b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff
@@ -83,55 +83,39 @@
           _10 = ((_7 as Some).0: usize);   // scope 3 at $DIR/funky_arms.rs:+13:17: +13:26
           StorageLive(_11);                // scope 3 at $DIR/funky_arms.rs:+15:43: +15:46
           _11 = &mut (*_1);                // scope 3 at $DIR/funky_arms.rs:+15:43: +15:46
-          StorageLive(_12);                // scope 3 at $DIR/funky_arms.rs:+15:48: +15:51
-          _12 = _2;                        // scope 3 at $DIR/funky_arms.rs:+15:48: +15:51
           StorageLive(_13);                // scope 3 at $DIR/funky_arms.rs:+15:53: +15:57
           _13 = _6;                        // scope 3 at $DIR/funky_arms.rs:+15:53: +15:57
           StorageLive(_14);                // scope 3 at $DIR/funky_arms.rs:+15:59: +15:79
           StorageLive(_15);                // scope 3 at $DIR/funky_arms.rs:+15:59: +15:75
-          StorageLive(_16);                // scope 3 at $DIR/funky_arms.rs:+15:59: +15:68
-          _16 = _10;                       // scope 3 at $DIR/funky_arms.rs:+15:59: +15:68
-          _15 = move _16 as u32 (IntToInt); // scope 3 at $DIR/funky_arms.rs:+15:59: +15:75
-          StorageDead(_16);                // scope 3 at $DIR/funky_arms.rs:+15:74: +15:75
+          _15 = _10 as u32 (IntToInt);     // scope 3 at $DIR/funky_arms.rs:+15:59: +15:75
           _14 = Add(move _15, const 1_u32); // scope 3 at $DIR/funky_arms.rs:+15:59: +15:79
           StorageDead(_15);                // scope 3 at $DIR/funky_arms.rs:+15:78: +15:79
-          StorageLive(_17);                // scope 3 at $DIR/funky_arms.rs:+15:81: +15:86
-          _17 = _3;                        // scope 3 at $DIR/funky_arms.rs:+15:81: +15:86
-          _0 = float_to_exponential_common_exact::<T>(move _11, move _12, move _13, move _14, move _17) -> bb7; // scope 3 at $DIR/funky_arms.rs:+15:9: +15:87
+          _0 = float_to_exponential_common_exact::<T>(move _11, _2, move _13, move _14, _3) -> bb7; // scope 3 at $DIR/funky_arms.rs:+15:9: +15:87
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:26:9: 26:42
                                            // + literal: Const { ty: for<'a, 'b, 'c> fn(&'a mut Formatter<'b>, &'c T, Sign, u32, bool) -> Result<(), std::fmt::Error> {float_to_exponential_common_exact::<T>}, val: Value(<ZST>) }
       }
   
       bb7: {
-          StorageDead(_17);                // scope 3 at $DIR/funky_arms.rs:+15:86: +15:87
           StorageDead(_14);                // scope 3 at $DIR/funky_arms.rs:+15:86: +15:87
           StorageDead(_13);                // scope 3 at $DIR/funky_arms.rs:+15:86: +15:87
-          StorageDead(_12);                // scope 3 at $DIR/funky_arms.rs:+15:86: +15:87
           StorageDead(_11);                // scope 3 at $DIR/funky_arms.rs:+15:86: +15:87
-          StorageDead(_10);                // scope 2 at $DIR/funky_arms.rs:+16:5: +16:6
           goto -> bb10;                    // scope 2 at $DIR/funky_arms.rs:+13:5: +18:6
       }
   
       bb8: {
           StorageLive(_18);                // scope 2 at $DIR/funky_arms.rs:+17:46: +17:49
           _18 = &mut (*_1);                // scope 2 at $DIR/funky_arms.rs:+17:46: +17:49
-          StorageLive(_19);                // scope 2 at $DIR/funky_arms.rs:+17:51: +17:54
-          _19 = _2;                        // scope 2 at $DIR/funky_arms.rs:+17:51: +17:54
           StorageLive(_20);                // scope 2 at $DIR/funky_arms.rs:+17:56: +17:60
           _20 = _6;                        // scope 2 at $DIR/funky_arms.rs:+17:56: +17:60
-          StorageLive(_21);                // scope 2 at $DIR/funky_arms.rs:+17:62: +17:67
-          _21 = _3;                        // scope 2 at $DIR/funky_arms.rs:+17:62: +17:67
-          _0 = float_to_exponential_common_shortest::<T>(move _18, move _19, move _20, move _21) -> bb9; // scope 2 at $DIR/funky_arms.rs:+17:9: +17:68
+          _0 = float_to_exponential_common_shortest::<T>(move _18, _2, move _20, _3) -> bb9; // scope 2 at $DIR/funky_arms.rs:+17:9: +17:68
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:28:9: 28:45
                                            // + literal: Const { ty: for<'a, 'b, 'c> fn(&'a mut Formatter<'b>, &'c T, Sign, bool) -> Result<(), std::fmt::Error> {float_to_exponential_common_shortest::<T>}, val: Value(<ZST>) }
       }
   
       bb9: {
-          StorageDead(_21);                // scope 2 at $DIR/funky_arms.rs:+17:67: +17:68
           StorageDead(_20);                // scope 2 at $DIR/funky_arms.rs:+17:67: +17:68
-          StorageDead(_19);                // scope 2 at $DIR/funky_arms.rs:+17:67: +17:68
           StorageDead(_18);                // scope 2 at $DIR/funky_arms.rs:+17:67: +17:68
           goto -> bb10;                    // scope 2 at $DIR/funky_arms.rs:+13:5: +18:6
       }
diff --git a/tests/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir b/tests/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir
index a8e090020c3..afe51864214 100644
--- a/tests/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir
+++ b/tests/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir
@@ -1,7 +1,14 @@
 // MIR for `main::{closure#0}` 0 generator_drop
 /* generator_layout = GeneratorLayout {
     field_tys: {
-        _0: std::string::String,
+        _0: GeneratorSavedTy {
+            ty: std::string::String,
+            source_info: SourceInfo {
+                span: $DIR/generator_drop_cleanup.rs:11:13: 11:15 (#0),
+                scope: scope[0],
+            },
+            ignore_for_traits: false,
+        },
     },
     variant_fields: {
         Unresumed(0): [],
diff --git a/tests/mir-opt/generator_tiny.main-{closure#0}.generator_resume.0.mir b/tests/mir-opt/generator_tiny.main-{closure#0}.generator_resume.0.mir
index b3d3c768a5d..2f096c3e0a1 100644
--- a/tests/mir-opt/generator_tiny.main-{closure#0}.generator_resume.0.mir
+++ b/tests/mir-opt/generator_tiny.main-{closure#0}.generator_resume.0.mir
@@ -1,7 +1,14 @@
 // MIR for `main::{closure#0}` 0 generator_resume
 /* generator_layout = GeneratorLayout {
     field_tys: {
-        _0: HasDrop,
+        _0: GeneratorSavedTy {
+            ty: HasDrop,
+            source_info: SourceInfo {
+                span: $DIR/generator_tiny.rs:20:13: 20:15 (#0),
+                scope: scope[0],
+            },
+            ignore_for_traits: false,
+        },
     },
     variant_fields: {
         Unresumed(0): [],
diff --git a/tests/mir-opt/inline/dyn_trait.get_query.Inline.diff b/tests/mir-opt/inline/dyn_trait.get_query.Inline.diff
index 8ea1a0757f2..64c3e47ff46 100644
--- a/tests/mir-opt/inline/dyn_trait.get_query.Inline.diff
+++ b/tests/mir-opt/inline/dyn_trait.get_query.Inline.diff
@@ -35,8 +35,8 @@
           _4 = &(*_2);                     // scope 1 at $DIR/dyn_trait.rs:+2:23: +2:24
 -         _0 = try_execute_query::<<Q as Query>::C>(move _4) -> bb2; // scope 1 at $DIR/dyn_trait.rs:+2:5: +2:25
 +         StorageLive(_5);                 // scope 2 at $DIR/dyn_trait.rs:27:14: 27:15
-+         _5 = move _4 as &dyn Cache<V = <Q as Query>::V> (Pointer(Unsize)); // scope 2 at $DIR/dyn_trait.rs:27:14: 27:15
-+         _0 = <dyn Cache<V = <Q as Query>::V> as Cache>::store_nocache(move _5) -> bb2; // scope 3 at $DIR/dyn_trait.rs:21:5: 21:22
++         _5 = _4 as &dyn Cache<V = <Q as Query>::V> (Pointer(Unsize)); // scope 2 at $DIR/dyn_trait.rs:27:14: 27:15
++         _0 = <dyn Cache<V = <Q as Query>::V> as Cache>::store_nocache(_5) -> bb2; // scope 3 at $DIR/dyn_trait.rs:21:5: 21:22
                                            // mir::Constant
 -                                          // + span: $DIR/dyn_trait.rs:34:5: 34:22
 -                                          // + literal: Const { ty: for<'a> fn(&'a <Q as Query>::C) {try_execute_query::<<Q as Query>::C>}, val: Value(<ZST>) }
diff --git a/tests/mir-opt/inline/dyn_trait.try_execute_query.Inline.diff b/tests/mir-opt/inline/dyn_trait.try_execute_query.Inline.diff
index a71d73b7453..3fa9c3e88f6 100644
--- a/tests/mir-opt/inline/dyn_trait.try_execute_query.Inline.diff
+++ b/tests/mir-opt/inline/dyn_trait.try_execute_query.Inline.diff
@@ -17,7 +17,7 @@
           _2 = move _3 as &dyn Cache<V = <C as Cache>::V> (Pointer(Unsize)); // scope 0 at $DIR/dyn_trait.rs:+1:14: +1:15
           StorageDead(_3);                 // scope 0 at $DIR/dyn_trait.rs:+1:14: +1:15
 -         _0 = mk_cycle::<<C as Cache>::V>(move _2) -> bb1; // scope 0 at $DIR/dyn_trait.rs:+1:5: +1:16
-+         _0 = <dyn Cache<V = <C as Cache>::V> as Cache>::store_nocache(move _2) -> bb1; // scope 1 at $DIR/dyn_trait.rs:21:5: 21:22
++         _0 = <dyn Cache<V = <C as Cache>::V> as Cache>::store_nocache(_2) -> bb1; // scope 1 at $DIR/dyn_trait.rs:21:5: 21:22
                                            // mir::Constant
 -                                          // + span: $DIR/dyn_trait.rs:27:5: 27:13
 -                                          // + literal: Const { ty: for<'a> fn(&'a (dyn Cache<V = <C as Cache>::V> + 'a)) {mk_cycle::<<C as Cache>::V>}, val: Value(<ZST>) }
diff --git a/tests/mir-opt/inline/inline_any_operand.bar.Inline.after.mir b/tests/mir-opt/inline/inline_any_operand.bar.Inline.after.mir
index 3502c25864b..20f737cc29f 100644
--- a/tests/mir-opt/inline/inline_any_operand.bar.Inline.after.mir
+++ b/tests/mir-opt/inline/inline_any_operand.bar.Inline.after.mir
@@ -26,7 +26,7 @@ fn bar() -> bool {
         _3 = const 1_i32;                // scope 1 at $DIR/inline_any_operand.rs:+2:5: +2:13
         StorageLive(_4);                 // scope 1 at $DIR/inline_any_operand.rs:+2:5: +2:13
         _4 = const -1_i32;               // scope 1 at $DIR/inline_any_operand.rs:+2:5: +2:13
-        _0 = Eq(move _3, move _4);       // scope 2 at $DIR/inline_any_operand.rs:17:5: 17:11
+        _0 = Eq(_3, _4);                 // scope 2 at $DIR/inline_any_operand.rs:17:5: 17:11
         StorageDead(_4);                 // scope 1 at $DIR/inline_any_operand.rs:+2:5: +2:13
         StorageDead(_3);                 // scope 1 at $DIR/inline_any_operand.rs:+2:5: +2:13
         StorageDead(_2);                 // scope 1 at $DIR/inline_any_operand.rs:+2:12: +2:13
diff --git a/tests/mir-opt/inline/inline_generator.main.Inline.diff b/tests/mir-opt/inline/inline_generator.main.Inline.diff
index f27b64c3054..57574acf923 100644
--- a/tests/mir-opt/inline/inline_generator.main.Inline.diff
+++ b/tests/mir-opt/inline/inline_generator.main.Inline.diff
@@ -92,7 +92,7 @@
 + 
 +     bb3: {
 +         StorageLive(_8);                 // scope 6 at $DIR/inline_generator.rs:15:17: 15:39
-+         switchInt(move _7) -> [0: bb5, otherwise: bb4]; // scope 6 at $DIR/inline_generator.rs:15:20: 15:21
++         switchInt(_7) -> [0: bb5, otherwise: bb4]; // scope 6 at $DIR/inline_generator.rs:15:20: 15:21
 +     }
 + 
 +     bb4: {
@@ -118,7 +118,7 @@
 +         StorageLive(_8);                 // scope 6 at $DIR/inline_generator.rs:15:5: 15:41
 +         StorageDead(_8);                 // scope 6 at $DIR/inline_generator.rs:15:38: 15:39
 +         Deinit(_1);                      // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
-+         ((_1 as Complete).0: bool) = move _7; // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
++         ((_1 as Complete).0: bool) = _7; // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
 +         discriminant(_1) = 1;            // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
 +         _12 = deref_copy (_2.0: &mut [generator@$DIR/inline_generator.rs:15:5: 15:8]); // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
 +         discriminant((*_12)) = 1;        // scope 6 at $DIR/inline_generator.rs:15:41: 15:41
diff --git a/tests/mir-opt/inline/inline_trait_method_2.test2.Inline.after.mir b/tests/mir-opt/inline/inline_trait_method_2.test2.Inline.after.mir
index 73aea719eed..b7c5bbecb68 100644
--- a/tests/mir-opt/inline/inline_trait_method_2.test2.Inline.after.mir
+++ b/tests/mir-opt/inline/inline_trait_method_2.test2.Inline.after.mir
@@ -15,7 +15,7 @@ fn test2(_1: &dyn X) -> bool {
         _3 = &(*_1);                     // scope 0 at $DIR/inline_trait_method_2.rs:+1:10: +1:11
         _2 = move _3 as &dyn X (Pointer(Unsize)); // scope 0 at $DIR/inline_trait_method_2.rs:+1:10: +1:11
         StorageDead(_3);                 // scope 0 at $DIR/inline_trait_method_2.rs:+1:10: +1:11
-        _0 = <dyn X as X>::y(move _2) -> bb1; // scope 1 at $DIR/inline_trait_method_2.rs:10:5: 10:10
+        _0 = <dyn X as X>::y(_2) -> bb1; // scope 1 at $DIR/inline_trait_method_2.rs:10:5: 10:10
                                          // mir::Constant
                                          // + span: $DIR/inline_trait_method_2.rs:10:7: 10:8
                                          // + literal: Const { ty: for<'a> fn(&'a dyn X) -> bool {<dyn X as X>::y}, val: Value(<ZST>) }
diff --git a/tests/mir-opt/intrinsic_asserts.generic.InstCombine.diff b/tests/mir-opt/intrinsic_asserts.generic.InstCombine.diff
new file mode 100644
index 00000000000..8ff64c1ea15
--- /dev/null
+++ b/tests/mir-opt/intrinsic_asserts.generic.InstCombine.diff
@@ -0,0 +1,42 @@
+- // MIR for `generic` before InstCombine
++ // MIR for `generic` after InstCombine
+  
+  fn generic() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/intrinsic_asserts.rs:+0:21: +0:21
+      let _1: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:46
+      let _2: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:47
+      let _3: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:60
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:46
+          _1 = assert_inhabited::<T>() -> bb1; // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:46
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:25:5: 25:44
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_inhabited::<T>}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageDead(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:46: +1:47
+          StorageLive(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:47
+          _2 = assert_zero_valid::<T>() -> bb2; // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:47
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:26:5: 26:45
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_zero_valid::<T>}, val: Value(<ZST>) }
+      }
+  
+      bb2: {
+          StorageDead(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:47: +2:48
+          StorageLive(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:60
+          _3 = assert_mem_uninitialized_valid::<T>() -> bb3; // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:60
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:27:5: 27:58
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_mem_uninitialized_valid::<T>}, val: Value(<ZST>) }
+      }
+  
+      bb3: {
+          StorageDead(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:60: +3:61
+          nop;                             // scope 0 at $DIR/intrinsic_asserts.rs:+0:21: +4:2
+          return;                          // scope 0 at $DIR/intrinsic_asserts.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/intrinsic_asserts.panics.InstCombine.diff b/tests/mir-opt/intrinsic_asserts.panics.InstCombine.diff
new file mode 100644
index 00000000000..ddc01590315
--- /dev/null
+++ b/tests/mir-opt/intrinsic_asserts.panics.InstCombine.diff
@@ -0,0 +1,47 @@
+- // MIR for `panics` before InstCombine
++ // MIR for `panics` after InstCombine
+  
+  fn panics() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/intrinsic_asserts.rs:+0:17: +0:17
+      let _1: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:50
+      let _2: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:49
+      let _3: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:62
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:50
+-         _1 = assert_inhabited::<Never>() -> bb1; // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:50
++         _1 = assert_inhabited::<Never>(); // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:50
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:17:5: 17:48
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_inhabited::<Never>}, val: Value(<ZST>) }
+      }
+  
+      bb1: {
+          StorageDead(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:50: +1:51
+          StorageLive(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:49
+-         _2 = assert_zero_valid::<&u8>() -> bb2; // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:49
++         _2 = assert_zero_valid::<&u8>(); // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:49
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:18:5: 18:47
+                                           // + user_ty: UserType(0)
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_zero_valid::<&u8>}, val: Value(<ZST>) }
+      }
+  
+      bb2: {
+          StorageDead(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:49: +2:50
+          StorageLive(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:62
+-         _3 = assert_mem_uninitialized_valid::<&u8>() -> bb3; // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:62
++         _3 = assert_mem_uninitialized_valid::<&u8>(); // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:62
+                                           // mir::Constant
+                                           // + span: $DIR/intrinsic_asserts.rs:19:5: 19:60
+                                           // + user_ty: UserType(1)
+                                           // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_mem_uninitialized_valid::<&u8>}, val: Value(<ZST>) }
+      }
+  
+      bb3: {
+          StorageDead(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:62: +3:63
+          nop;                             // scope 0 at $DIR/intrinsic_asserts.rs:+0:17: +4:2
+          return;                          // scope 0 at $DIR/intrinsic_asserts.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/intrinsic_asserts.removable.InstCombine.diff b/tests/mir-opt/intrinsic_asserts.removable.InstCombine.diff
new file mode 100644
index 00000000000..568fbf1a0d6
--- /dev/null
+++ b/tests/mir-opt/intrinsic_asserts.removable.InstCombine.diff
@@ -0,0 +1,45 @@
+- // MIR for `removable` before InstCombine
++ // MIR for `removable` after InstCombine
+  
+  fn removable() -> () {
+      let mut _0: ();                      // return place in scope 0 at $DIR/intrinsic_asserts.rs:+0:20: +0:20
+      let _1: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:47
+      let _2: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:48
+      let _3: ();                          // in scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:61
+  
+      bb0: {
+          StorageLive(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:47
+-         _1 = assert_inhabited::<()>() -> bb1; // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:47
+-                                          // mir::Constant
+-                                          // + span: $DIR/intrinsic_asserts.rs:7:5: 7:45
+-                                          // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_inhabited::<()>}, val: Value(<ZST>) }
++         goto -> bb1;                     // scope 0 at $DIR/intrinsic_asserts.rs:+1:5: +1:47
+      }
+  
+      bb1: {
+          StorageDead(_1);                 // scope 0 at $DIR/intrinsic_asserts.rs:+1:47: +1:48
+          StorageLive(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:48
+-         _2 = assert_zero_valid::<u8>() -> bb2; // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:48
+-                                          // mir::Constant
+-                                          // + span: $DIR/intrinsic_asserts.rs:8:5: 8:46
+-                                          // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_zero_valid::<u8>}, val: Value(<ZST>) }
++         goto -> bb2;                     // scope 0 at $DIR/intrinsic_asserts.rs:+2:5: +2:48
+      }
+  
+      bb2: {
+          StorageDead(_2);                 // scope 0 at $DIR/intrinsic_asserts.rs:+2:48: +2:49
+          StorageLive(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:61
+-         _3 = assert_mem_uninitialized_valid::<u8>() -> bb3; // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:61
+-                                          // mir::Constant
+-                                          // + span: $DIR/intrinsic_asserts.rs:9:5: 9:59
+-                                          // + literal: Const { ty: extern "rust-intrinsic" fn() {assert_mem_uninitialized_valid::<u8>}, val: Value(<ZST>) }
++         goto -> bb3;                     // scope 0 at $DIR/intrinsic_asserts.rs:+3:5: +3:61
+      }
+  
+      bb3: {
+          StorageDead(_3);                 // scope 0 at $DIR/intrinsic_asserts.rs:+3:61: +3:62
+          nop;                             // scope 0 at $DIR/intrinsic_asserts.rs:+0:20: +4:2
+          return;                          // scope 0 at $DIR/intrinsic_asserts.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/intrinsic_asserts.rs b/tests/mir-opt/intrinsic_asserts.rs
new file mode 100644
index 00000000000..8fb99cdf6e0
--- /dev/null
+++ b/tests/mir-opt/intrinsic_asserts.rs
@@ -0,0 +1,28 @@
+#![crate_type = "lib"]
+#![feature(core_intrinsics)]
+
+// All these assertions pass, so all the intrinsic calls should be deleted.
+// EMIT_MIR intrinsic_asserts.removable.InstCombine.diff
+pub fn removable() {
+    core::intrinsics::assert_inhabited::<()>();
+    core::intrinsics::assert_zero_valid::<u8>();
+    core::intrinsics::assert_mem_uninitialized_valid::<u8>();
+}
+
+enum Never {}
+
+// These assertions all diverge, so their target blocks should become None.
+// EMIT_MIR intrinsic_asserts.panics.InstCombine.diff
+pub fn panics() {
+    core::intrinsics::assert_inhabited::<Never>();
+    core::intrinsics::assert_zero_valid::<&u8>();
+    core::intrinsics::assert_mem_uninitialized_valid::<&u8>();
+}
+
+// Whether or not these asserts pass isn't known, so they shouldn't be modified.
+// EMIT_MIR intrinsic_asserts.generic.InstCombine.diff
+pub fn generic<T>() {
+    core::intrinsics::assert_inhabited::<T>();
+    core::intrinsics::assert_zero_valid::<T>();
+    core::intrinsics::assert_mem_uninitialized_valid::<T>();
+}
diff --git a/tests/mir-opt/issue_101973.inner.ConstProp.diff b/tests/mir-opt/issue_101973.inner.ConstProp.diff
index b2706e5a436..30bf2c0684e 100644
--- a/tests/mir-opt/issue_101973.inner.ConstProp.diff
+++ b/tests/mir-opt/issue_101973.inner.ConstProp.diff
@@ -15,7 +15,7 @@
       let mut _10: (u32, bool);            // in scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
       let mut _11: (u32, bool);            // in scope 0 at $DIR/issue_101973.rs:+1:31: +1:57
       scope 1 (inlined imm8) {             // at $DIR/issue_101973.rs:14:5: 14:17
-          debug x => _5;                   // in scope 1 at $DIR/issue_101973.rs:5:13: 5:14
+          debug x => _1;                   // in scope 1 at $DIR/issue_101973.rs:5:13: 5:14
           let mut _12: u32;                // in scope 1 at $DIR/issue_101973.rs:7:12: 7:27
           let mut _13: u32;                // in scope 1 at $DIR/issue_101973.rs:7:12: 7:20
           let mut _14: (u32, bool);        // in scope 1 at $DIR/issue_101973.rs:7:12: 7:20
@@ -34,17 +34,14 @@
           StorageLive(_2);                 // scope 0 at $DIR/issue_101973.rs:+1:5: +1:65
           StorageLive(_3);                 // scope 0 at $DIR/issue_101973.rs:+1:5: +1:58
           StorageLive(_4);                 // scope 0 at $DIR/issue_101973.rs:+1:5: +1:17
-          StorageLive(_5);                 // scope 0 at $DIR/issue_101973.rs:+1:10: +1:16
-          _5 = _1;                         // scope 0 at $DIR/issue_101973.rs:+1:10: +1:16
           StorageLive(_12);                // scope 2 at $DIR/issue_101973.rs:7:12: 7:27
           StorageLive(_13);                // scope 2 at $DIR/issue_101973.rs:7:12: 7:20
-          _14 = CheckedShr(_5, const 0_i32); // scope 2 at $DIR/issue_101973.rs:7:12: 7:20
+          _14 = CheckedShr(_1, const 0_i32); // scope 2 at $DIR/issue_101973.rs:7:12: 7:20
           assert(!move (_14.1: bool), "attempt to shift right by `{}`, which would overflow", const 0_i32) -> bb3; // scope 2 at $DIR/issue_101973.rs:7:12: 7:20
       }
   
       bb1: {
           _8 = move (_10.0: u32);          // scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
-          StorageDead(_9);                 // scope 0 at $DIR/issue_101973.rs:+1:44: +1:45
           _7 = BitAnd(move _8, const 15_u32); // scope 0 at $DIR/issue_101973.rs:+1:31: +1:52
           StorageDead(_8);                 // scope 0 at $DIR/issue_101973.rs:+1:51: +1:52
           _11 = CheckedShl(_7, const 1_i32); // scope 0 at $DIR/issue_101973.rs:+1:31: +1:57
@@ -54,11 +51,7 @@
       bb2: {
           _6 = move (_11.0: u32);          // scope 0 at $DIR/issue_101973.rs:+1:31: +1:57
           StorageDead(_7);                 // scope 0 at $DIR/issue_101973.rs:+1:56: +1:57
-          StorageLive(_15);                // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          _15 = _4;                        // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          StorageLive(_16);                // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          _16 = _6;                        // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          _3 = rotate_right::<u32>(move _15, move _16) -> bb4; // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
+          _3 = rotate_right::<u32>(_4, _6) -> bb4; // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
                                            // mir::Constant
                                            // + span: $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
                                            // + literal: Const { ty: extern "rust-intrinsic" fn(u32, u32) -> u32 {rotate_right::<u32>}, val: Value(<ZST>) }
@@ -70,21 +63,14 @@
           StorageDead(_13);                // scope 2 at $DIR/issue_101973.rs:7:26: 7:27
           _4 = BitOr(const 0_u32, move _12); // scope 2 at $DIR/issue_101973.rs:7:5: 7:27
           StorageDead(_12);                // scope 2 at $DIR/issue_101973.rs:7:26: 7:27
-          StorageDead(_5);                 // scope 0 at $DIR/issue_101973.rs:+1:16: +1:17
           StorageLive(_6);                 // scope 0 at $DIR/issue_101973.rs:+1:31: +1:57
           StorageLive(_7);                 // scope 0 at $DIR/issue_101973.rs:+1:31: +1:52
           StorageLive(_8);                 // scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
-          StorageLive(_9);                 // scope 0 at $DIR/issue_101973.rs:+1:33: +1:39
-          _9 = _1;                         // scope 0 at $DIR/issue_101973.rs:+1:33: +1:39
-          _10 = CheckedShr(_9, const 8_i32); // scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
+          _10 = CheckedShr(_1, const 8_i32); // scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
           assert(!move (_10.1: bool), "attempt to shift right by `{}`, which would overflow", const 8_i32) -> bb1; // scope 0 at $DIR/issue_101973.rs:+1:32: +1:45
       }
   
       bb4: {
-          StorageDead(_16);                // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          StorageDead(_15);                // scope 3 at $SRC_DIR/core/src/num/uint_macros.rs:LL:COL
-          StorageDead(_6);                 // scope 0 at $DIR/issue_101973.rs:+1:57: +1:58
-          StorageDead(_4);                 // scope 0 at $DIR/issue_101973.rs:+1:57: +1:58
           _2 = move _3 as i32 (IntToInt);  // scope 0 at $DIR/issue_101973.rs:+1:5: +1:65
           StorageDead(_3);                 // scope 0 at $DIR/issue_101973.rs:+1:64: +1:65
           _0 = move _2 as i64 (IntToInt);  // scope 0 at $DIR/issue_101973.rs:+1:5: +1:72
diff --git a/tests/mir-opt/issue_73223.main.SimplifyArmIdentity.diff b/tests/mir-opt/issue_73223.main.SimplifyArmIdentity.diff
deleted file mode 100644
index bf3bcfdb594..00000000000
--- a/tests/mir-opt/issue_73223.main.SimplifyArmIdentity.diff
+++ /dev/null
@@ -1,156 +0,0 @@
-- // MIR for `main` before SimplifyArmIdentity
-+ // MIR for `main` after SimplifyArmIdentity
-  
-  fn main() -> () {
-      let mut _0: ();                      // return place in scope 0 at $DIR/issue_73223.rs:+0:11: +0:11
-      let _1: i32;                         // in scope 0 at $DIR/issue_73223.rs:+1:9: +1:14
-      let mut _2: std::option::Option<i32>; // in scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-      let mut _3: isize;                   // in scope 0 at $DIR/issue_73223.rs:+2:9: +2:16
-      let _4: i32;                         // in scope 0 at $DIR/issue_73223.rs:+2:14: +2:15
-      let mut _6: i32;                     // in scope 0 at $DIR/issue_73223.rs:+6:22: +6:27
-      let mut _7: &i32;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _8: &i32;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _11: bool;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _12: bool;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _13: i32;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _14: i32;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let _16: !;                          // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _17: core::panicking::AssertKind; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _18: &i32;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let _19: &i32;                       // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _20: &i32;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let _21: &i32;                       // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _22: std::option::Option<std::fmt::Arguments<'_>>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _24: &i32;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _25: &i32;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      scope 1 {
-          debug split => _1;               // in scope 1 at $DIR/issue_73223.rs:+1:9: +1:14
-          let _5: std::option::Option<i32>; // in scope 1 at $DIR/issue_73223.rs:+6:9: +6:14
-          scope 3 {
-              debug _prev => _5;           // in scope 3 at $DIR/issue_73223.rs:+6:9: +6:14
-              let _9: &i32;                // in scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-              let _10: &i32;               // in scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-              let mut _23: &i32;           // in scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-              scope 4 {
-                  debug left_val => _9;    // in scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                  debug right_val => _10;  // in scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                  let _15: core::panicking::AssertKind; // in scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                  scope 5 {
-                      debug kind => _15;   // in scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                  }
-              }
-          }
-      }
-      scope 2 {
-          debug v => _4;                   // in scope 2 at $DIR/issue_73223.rs:+2:14: +2:15
-      }
-  
-      bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/issue_73223.rs:+1:9: +1:14
-          StorageLive(_2);                 // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-          Deinit(_2);                      // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-          ((_2 as Some).0: i32) = const 1_i32; // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-          discriminant(_2) = 1;            // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-          _3 = const 1_isize;              // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-          goto -> bb3;                     // scope 0 at $DIR/issue_73223.rs:+1:17: +1:30
-      }
-  
-      bb1: {
-          StorageDead(_2);                 // scope 0 at $DIR/issue_73223.rs:+4:6: +4:7
-          StorageDead(_1);                 // scope 0 at $DIR/issue_73223.rs:+8:1: +8:2
-          return;                          // scope 0 at $DIR/issue_73223.rs:+8:2: +8:2
-      }
-  
-      bb2: {
-          unreachable;                     // scope 0 at $DIR/issue_73223.rs:+1:23: +1:30
-      }
-  
-      bb3: {
-          StorageLive(_4);                 // scope 0 at $DIR/issue_73223.rs:+2:14: +2:15
-          _4 = ((_2 as Some).0: i32);      // scope 0 at $DIR/issue_73223.rs:+2:14: +2:15
-          _1 = _4;                         // scope 2 at $DIR/issue_73223.rs:+2:20: +2:21
-          StorageDead(_4);                 // scope 0 at $DIR/issue_73223.rs:+2:20: +2:21
-          StorageDead(_2);                 // scope 0 at $DIR/issue_73223.rs:+4:6: +4:7
-          StorageLive(_5);                 // scope 1 at $DIR/issue_73223.rs:+6:9: +6:14
-          StorageLive(_6);                 // scope 1 at $DIR/issue_73223.rs:+6:22: +6:27
-          _6 = _1;                         // scope 1 at $DIR/issue_73223.rs:+6:22: +6:27
-          Deinit(_5);                      // scope 1 at $DIR/issue_73223.rs:+6:17: +6:28
-          ((_5 as Some).0: i32) = move _6; // scope 1 at $DIR/issue_73223.rs:+6:17: +6:28
-          discriminant(_5) = 1;            // scope 1 at $DIR/issue_73223.rs:+6:17: +6:28
-          StorageDead(_6);                 // scope 1 at $DIR/issue_73223.rs:+6:27: +6:28
-          StorageLive(_24);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_25);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_7);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _7 = &_1;                        // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_8);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _23 = const _;                   // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // mir::Constant
-                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // + literal: Const { ty: &i32, val: Unevaluated(main, [], Some(promoted[0])) }
-          _8 = _23;                        // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          Deinit(_24);                     // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          Deinit(_25);                     // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _24 = move _7;                   // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _25 = move _8;                   // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_8);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_7);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_9);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _9 = _24;                        // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_10);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _10 = _25;                       // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_11);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_12);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_13);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _13 = (*_9);                     // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_14);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _14 = const 1_i32;               // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _12 = Eq(move _13, const 1_i32); // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_14);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_13);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _11 = Not(move _12);             // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_12);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          switchInt(move _11) -> [0: bb5, otherwise: bb4]; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      }
-  
-      bb4: {
-          StorageLive(_15);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          Deinit(_15);                     // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          discriminant(_15) = 0;           // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_16);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_17);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _17 = const core::panicking::AssertKind::Eq; // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // mir::Constant
-                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // + literal: Const { ty: core::panicking::AssertKind, val: Value(Scalar(0x00)) }
-          StorageLive(_18);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_19);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _19 = _9;                        // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _18 = _19;                       // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_20);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_21);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _21 = _10;                       // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _20 = _21;                       // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageLive(_22);                // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          Deinit(_22);                     // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          discriminant(_22) = 0;           // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _16 = core::panicking::assert_failed::<i32, i32>(const core::panicking::AssertKind::Eq, move _18, move _20, move _22); // scope 5 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // mir::Constant
-                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // + literal: Const { ty: for<'a, 'b, 'c> fn(core::panicking::AssertKind, &'a i32, &'b i32, Option<Arguments<'c>>) -> ! {core::panicking::assert_failed::<i32, i32>}, val: Value(<ZST>) }
-                                           // mir::Constant
-                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
-                                           // + literal: Const { ty: core::panicking::AssertKind, val: Value(Scalar(0x00)) }
-      }
-  
-      bb5: {
-          StorageDead(_11);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_10);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_9);                 // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_24);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_25);                // scope 3 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          StorageDead(_5);                 // scope 1 at $DIR/issue_73223.rs:+8:1: +8:2
-          StorageDead(_1);                 // scope 0 at $DIR/issue_73223.rs:+8:1: +8:2
-          return;                          // scope 0 at $DIR/issue_73223.rs:+8:2: +8:2
-      }
-  }
-  
diff --git a/tests/mir-opt/issue_73223.rs b/tests/mir-opt/issue_73223.rs
deleted file mode 100644
index be114cab719..00000000000
--- a/tests/mir-opt/issue_73223.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-fn main() {
-    let split = match Some(1) {
-        Some(v) => v,
-        None => return,
-    };
-
-    let _prev = Some(split);
-    assert_eq!(split, 1);
-}
-
-
-// EMIT_MIR issue_73223.main.SimplifyArmIdentity.diff
diff --git a/tests/mir-opt/issue_76432.rs b/tests/mir-opt/issue_76432.rs
index c8b405ca8ea..fbbfd4ceb11 100644
--- a/tests/mir-opt/issue_76432.rs
+++ b/tests/mir-opt/issue_76432.rs
@@ -1,3 +1,4 @@
+// compile-flags: -Zmir-enable-passes=-NormalizeArrayLen
 // Check that we do not insert StorageDead at each target if StorageDead was never seen
 
 // EMIT_MIR issue_76432.test.SimplifyComparisonIntegral.diff
diff --git a/tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff b/tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
index c24543daeac..c14780052fb 100644
--- a/tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
+++ b/tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
@@ -29,24 +29,11 @@
   
       bb0: {
           StorageLive(_2);                 // scope 0 at $DIR/issue_76432.rs:+1:9: +1:10
-          StorageLive(_3);                 // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
           StorageLive(_4);                 // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
           StorageLive(_5);                 // scope 0 at $DIR/issue_76432.rs:+1:20: +1:29
-          StorageLive(_6);                 // scope 0 at $DIR/issue_76432.rs:+1:21: +1:22
-          _6 = _1;                         // scope 0 at $DIR/issue_76432.rs:+1:21: +1:22
-          StorageLive(_7);                 // scope 0 at $DIR/issue_76432.rs:+1:24: +1:25
-          _7 = _1;                         // scope 0 at $DIR/issue_76432.rs:+1:24: +1:25
-          StorageLive(_8);                 // scope 0 at $DIR/issue_76432.rs:+1:27: +1:28
-          _8 = _1;                         // scope 0 at $DIR/issue_76432.rs:+1:27: +1:28
-          _5 = [move _6, move _7, move _8]; // scope 0 at $DIR/issue_76432.rs:+1:20: +1:29
-          StorageDead(_8);                 // scope 0 at $DIR/issue_76432.rs:+1:28: +1:29
-          StorageDead(_7);                 // scope 0 at $DIR/issue_76432.rs:+1:28: +1:29
-          StorageDead(_6);                 // scope 0 at $DIR/issue_76432.rs:+1:28: +1:29
+          _5 = [_1, _1, _1];               // scope 0 at $DIR/issue_76432.rs:+1:20: +1:29
           _4 = &_5;                        // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
-          _3 = _4;                         // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
-          _2 = move _3 as &[T] (Pointer(Unsize)); // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
-          StorageDead(_3);                 // scope 0 at $DIR/issue_76432.rs:+1:28: +1:29
-          StorageDead(_4);                 // scope 0 at $DIR/issue_76432.rs:+1:29: +1:30
+          _2 = _4 as &[T] (Pointer(Unsize)); // scope 0 at $DIR/issue_76432.rs:+1:19: +1:29
           _9 = Len((*_2));                 // scope 1 at $DIR/issue_76432.rs:+3:9: +3:33
           _10 = const 3_usize;             // scope 1 at $DIR/issue_76432.rs:+3:9: +3:33
 -         _11 = Eq(move _9, const 3_usize); // scope 1 at $DIR/issue_76432.rs:+3:9: +3:33
diff --git a/tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff
index 9bc7060e958..59de067f4a4 100644
--- a/tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff
+++ b/tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff
@@ -13,7 +13,6 @@
       let _8: usize;                       // in scope 0 at $DIR/lower_array_len.rs:+2:15: +2:20
       let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len.rs:+2:9: +2:21
       let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len.rs:+2:9: +2:21
-+     let mut _11: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
   
       bb0: {
           StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:8: +1:27
@@ -23,13 +22,10 @@
           StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         StorageLive(_11);                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         _11 = _7;                        // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:+1:20: +1:21
 -         _5 = Len((*_6));                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         _5 = Len((*_11));                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         StorageDead(_11);                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
++         _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
       }
   
diff --git a/tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff
index cf427cfd1e6..17574b1b635 100644
--- a/tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff
+++ b/tests/mir-opt/lower_array_len.array_bound_mut.NormalizeArrayLen.diff
@@ -16,7 +16,6 @@
       let _11: usize;                      // in scope 0 at $DIR/lower_array_len.rs:+4:15: +4:16
       let mut _12: usize;                  // in scope 0 at $DIR/lower_array_len.rs:+4:9: +4:17
       let mut _13: bool;                   // in scope 0 at $DIR/lower_array_len.rs:+4:9: +4:17
-+     let mut _14: &[u8; N];               // in scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
   
       bb0: {
           StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:8: +1:27
@@ -26,13 +25,10 @@
           StorageLive(_6);                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           StorageLive(_7);                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         StorageLive(_14);                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         _14 = _7;                        // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:+1:20: +1:21
 -         _5 = Len((*_6));                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         _5 = Len((*_14));                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-+         StorageDead(_14);                // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
++         _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
           goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
       }
   
diff --git a/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
index 3ed68f5f725..66feff62f42 100644
--- a/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
+++ b/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
@@ -6,19 +6,15 @@
       let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:+0:52: +0:57
       let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
       let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
   
       bb0: {
           StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           _3 = &(*_1);                     // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:7: +1:8
 -         _0 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
       }
   
diff --git a/tests/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff
index f0e0cdcfdc0..c0a277edc46 100644
--- a/tests/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff
+++ b/tests/mir-opt/lower_array_len.array_len_by_value.NormalizeArrayLen.diff
@@ -6,19 +6,15 @@
       let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:+0:60: +0:65
       let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
       let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
   
       bb0: {
           StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           _3 = &_1;                        // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:7: +1:8
 -         _0 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
-+         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         _0 = const N;                    // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
           goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
       }
   
diff --git a/tests/mir-opt/lower_array_len.array_len_raw.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_len_raw.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..8b35fd57fa0
--- /dev/null
+++ b/tests/mir-opt/lower_array_len.array_len_raw.NormalizeArrayLen.diff
@@ -0,0 +1,50 @@
+- // MIR for `array_len_raw` before NormalizeArrayLen
++ // MIR for `array_len_raw` after NormalizeArrayLen
+  
+  fn array_len_raw(_1: [u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:+0:38: +0:41
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:+0:55: +0:60
+      let _2: &[u8];                       // in scope 0 at $DIR/lower_array_len.rs:+1:9: +1:12
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+      let _4: &[u8; N];                    // in scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:+3:5: +3:27
+      let _7: &[u8];                       // in scope 0 at $DIR/lower_array_len.rs:+3:14: +3:19
+      scope 1 {
+          debug arr => _2;                 // in scope 1 at $DIR/lower_array_len.rs:+1:9: +1:12
+          let _5: *const [u8];             // in scope 1 at $DIR/lower_array_len.rs:+2:9: +2:12
+          scope 2 {
+              debug arr => _5;             // in scope 2 at $DIR/lower_array_len.rs:+2:9: +2:12
+              scope 3 {
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:9: +1:12
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+          _4 = &_1;                        // scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+          _3 = &(*_4);                     // scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:21: +1:25
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:24: +1:25
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:26
+          StorageLive(_5);                 // scope 1 at $DIR/lower_array_len.rs:+2:9: +2:12
+          _5 = &raw const (*_2);           // scope 1 at $SRC_DIR/core/src/ptr/mod.rs:LL:COL
+          StorageLive(_6);                 // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:27
+          StorageLive(_7);                 // scope 2 at $DIR/lower_array_len.rs:+3:14: +3:19
+          _7 = &(*_5);                     // scope 3 at $DIR/lower_array_len.rs:+3:14: +3:19
+          _6 = &(*_7);                     // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:27
+-         _0 = Len((*_6));                 // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:27
++         _0 = const N;                    // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:27
+          goto -> bb1;                     // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:27
+      }
+  
+      bb1: {
+          StorageDead(_6);                 // scope 2 at $DIR/lower_array_len.rs:+3:26: +3:27
+          StorageDead(_5);                 // scope 1 at $DIR/lower_array_len.rs:+4:1: +4:2
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:+4:1: +4:2
+          StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:+4:1: +4:2
+          return;                          // scope 0 at $DIR/lower_array_len.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/lower_array_len.array_len_reborrow.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_len_reborrow.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..8bdd2ede6bc
--- /dev/null
+++ b/tests/mir-opt/lower_array_len.array_len_reborrow.NormalizeArrayLen.diff
@@ -0,0 +1,44 @@
+- // MIR for `array_len_reborrow` before NormalizeArrayLen
++ // MIR for `array_len_reborrow` after NormalizeArrayLen
+  
+  fn array_len_reborrow(_1: [u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:+0:43: +0:50
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:+0:64: +0:69
+      let _2: &mut [u8];                   // in scope 0 at $DIR/lower_array_len.rs:+1:9: +1:12
+      let mut _3: &mut [u8; N];            // in scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+      let mut _4: &mut [u8; N];            // in scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+      let mut _6: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:+3:5: +3:14
+      scope 1 {
+          debug arr => _2;                 // in scope 1 at $DIR/lower_array_len.rs:+1:9: +1:12
+          let _5: &[u8];                   // in scope 1 at $DIR/lower_array_len.rs:+2:9: +2:12
+          scope 2 {
+              debug arr => _5;             // in scope 2 at $DIR/lower_array_len.rs:+2:9: +2:12
+          }
+      }
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:9: +1:12
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+          StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+          _4 = &mut _1;                    // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+          _3 = &mut (*_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+          _2 = move _3 as &mut [u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:25: +1:33
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:32: +1:33
+          StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:33: +1:34
+          StorageLive(_5);                 // scope 1 at $DIR/lower_array_len.rs:+2:9: +2:12
+          _5 = &(*_2);                     // scope 1 at $DIR/lower_array_len.rs:+2:15: +2:20
+          StorageLive(_6);                 // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:14
+          _6 = &(*_5);                     // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:14
+-         _0 = Len((*_6));                 // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:14
++         _0 = const N;                    // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:14
+          goto -> bb1;                     // scope 2 at $DIR/lower_array_len.rs:+3:5: +3:14
+      }
+  
+      bb1: {
+          StorageDead(_6);                 // scope 2 at $DIR/lower_array_len.rs:+3:13: +3:14
+          StorageDead(_5);                 // scope 1 at $DIR/lower_array_len.rs:+4:1: +4:2
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:+4:1: +4:2
+          return;                          // scope 0 at $DIR/lower_array_len.rs:+4:2: +4:2
+      }
+  }
+  
diff --git a/tests/mir-opt/lower_array_len.rs b/tests/mir-opt/lower_array_len.rs
index ea0224b21d7..972d46cb8e2 100644
--- a/tests/mir-opt/lower_array_len.rs
+++ b/tests/mir-opt/lower_array_len.rs
@@ -31,10 +31,26 @@ pub fn array_len_by_value<const N: usize>(arr: [u8; N]) -> usize {
     arr.len()
 }
 
+// EMIT_MIR lower_array_len.array_len_reborrow.NormalizeArrayLen.diff
+pub fn array_len_reborrow<const N: usize>(mut arr: [u8; N]) -> usize {
+    let arr: &mut [_] = &mut arr;
+    let arr = &*arr;
+    arr.len()
+}
+
+// EMIT_MIR lower_array_len.array_len_raw.NormalizeArrayLen.diff
+pub fn array_len_raw<const N: usize>(arr: [u8; N]) -> usize {
+    let arr: &[_] = &arr;
+    let arr = std::ptr::addr_of!(*arr);
+    unsafe { &*arr }.len()
+}
+
 fn main() {
     let _ = array_bound(3, &[0, 1, 2, 3]);
     let mut tmp = [0, 1, 2, 3, 4];
     let _ = array_bound_mut(3, &mut [0, 1, 2, 3]);
     let _ = array_len(&[0]);
     let _ = array_len_by_value([0, 2]);
+    let _ = array_len_reborrow([0, 2]);
+    let _ = array_len_raw([0, 2]);
 }
diff --git a/tests/mir-opt/lower_array_len_e2e.array_bound.PreCodegen.after.mir b/tests/mir-opt/lower_array_len_e2e.array_bound.PreCodegen.after.mir
deleted file mode 100644
index 701c2ad705a..00000000000
--- a/tests/mir-opt/lower_array_len_e2e.array_bound.PreCodegen.after.mir
+++ /dev/null
@@ -1,45 +0,0 @@
-// MIR for `array_bound` after PreCodegen
-
-fn array_bound(_1: usize, _2: &[u8; N]) -> u8 {
-    debug index => _1;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:36: +0:41
-    debug slice => _2;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:50: +0:55
-    let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len_e2e.rs:+0:70: +0:72
-    let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-    let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-    let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-    let mut _6: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-    let mut _7: bool;                    // in scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-
-    bb0: {
-        StorageLive(_3);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-        StorageLive(_4);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-        _4 = _1;                         // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-        StorageLive(_5);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-        _5 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-        _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-        StorageDead(_5);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:26: +1:27
-        StorageDead(_4);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:26: +1:27
-        switchInt(move _3) -> [0: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-    }
-
-    bb1: {
-        _6 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        _7 = Lt(_1, _6);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _1) -> bb2; // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-    }
-
-    bb2: {
-        _0 = (*_2)[_1];                  // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        goto -> bb4;                     // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +5:6
-    }
-
-    bb3: {
-        _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:11
-        goto -> bb4;                     // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +5:6
-    }
-
-    bb4: {
-        StorageDead(_3);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+5:5: +5:6
-        return;                          // scope 0 at $DIR/lower_array_len_e2e.rs:+6:2: +6:2
-    }
-}
diff --git a/tests/mir-opt/lower_array_len_e2e.array_bound_mut.PreCodegen.after.mir b/tests/mir-opt/lower_array_len_e2e.array_bound_mut.PreCodegen.after.mir
deleted file mode 100644
index 0440cfce289..00000000000
--- a/tests/mir-opt/lower_array_len_e2e.array_bound_mut.PreCodegen.after.mir
+++ /dev/null
@@ -1,58 +0,0 @@
-// MIR for `array_bound_mut` after PreCodegen
-
-fn array_bound_mut(_1: usize, _2: &mut [u8; N]) -> u8 {
-    debug index => _1;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:40: +0:45
-    debug slice => _2;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:54: +0:59
-    let mut _0: u8;                      // return place in scope 0 at $DIR/lower_array_len_e2e.rs:+0:78: +0:80
-    let mut _3: bool;                    // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-    let mut _4: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-    let mut _5: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-    let mut _6: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-    let mut _7: bool;                    // in scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-    let _8: usize;                       // in scope 0 at $DIR/lower_array_len_e2e.rs:+4:15: +4:16
-    let mut _9: usize;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:17
-    let mut _10: bool;                   // in scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:17
-
-    bb0: {
-        StorageLive(_3);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-        StorageLive(_4);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-        _4 = _1;                         // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:13
-        StorageLive(_5);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-        _5 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+1:16: +1:27
-        _3 = Lt(move _4, move _5);       // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-        StorageDead(_5);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:26: +1:27
-        StorageDead(_4);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+1:26: +1:27
-        switchInt(move _3) -> [0: bb3, otherwise: bb1]; // scope 0 at $DIR/lower_array_len_e2e.rs:+1:8: +1:27
-    }
-
-    bb1: {
-        _6 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        _7 = Lt(_1, _6);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _1) -> bb2; // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-    }
-
-    bb2: {
-        _0 = (*_2)[_1];                  // scope 0 at $DIR/lower_array_len_e2e.rs:+2:9: +2:21
-        goto -> bb5;                     // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +7:6
-    }
-
-    bb3: {
-        StorageLive(_8);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+4:15: +4:16
-        _8 = const 0_usize;              // scope 0 at $DIR/lower_array_len_e2e.rs:+4:15: +4:16
-        _9 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:17
-        _10 = Lt(const 0_usize, _9);     // scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:17
-        assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, const 0_usize) -> bb4; // scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:17
-    }
-
-    bb4: {
-        (*_2)[_8] = const 42_u8;         // scope 0 at $DIR/lower_array_len_e2e.rs:+4:9: +4:22
-        StorageDead(_8);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+4:22: +4:23
-        _0 = const 42_u8;                // scope 0 at $DIR/lower_array_len_e2e.rs:+6:9: +6:11
-        goto -> bb5;                     // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +7:6
-    }
-
-    bb5: {
-        StorageDead(_3);                 // scope 0 at $DIR/lower_array_len_e2e.rs:+7:5: +7:6
-        return;                          // scope 0 at $DIR/lower_array_len_e2e.rs:+8:2: +8:2
-    }
-}
diff --git a/tests/mir-opt/lower_array_len_e2e.array_len.PreCodegen.after.mir b/tests/mir-opt/lower_array_len_e2e.array_len.PreCodegen.after.mir
deleted file mode 100644
index 4b19f679558..00000000000
--- a/tests/mir-opt/lower_array_len_e2e.array_len.PreCodegen.after.mir
+++ /dev/null
@@ -1,11 +0,0 @@
-// MIR for `array_len` after PreCodegen
-
-fn array_len(_1: &[u8; N]) -> usize {
-    debug arr => _1;                     // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:34: +0:37
-    let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len_e2e.rs:+0:52: +0:57
-
-    bb0: {
-        _0 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +1:14
-        return;                          // scope 0 at $DIR/lower_array_len_e2e.rs:+2:2: +2:2
-    }
-}
diff --git a/tests/mir-opt/lower_array_len_e2e.array_len_by_value.PreCodegen.after.mir b/tests/mir-opt/lower_array_len_e2e.array_len_by_value.PreCodegen.after.mir
deleted file mode 100644
index 4dc0ba9a268..00000000000
--- a/tests/mir-opt/lower_array_len_e2e.array_len_by_value.PreCodegen.after.mir
+++ /dev/null
@@ -1,11 +0,0 @@
-// MIR for `array_len_by_value` after PreCodegen
-
-fn array_len_by_value(_1: [u8; N]) -> usize {
-    debug arr => _1;                     // in scope 0 at $DIR/lower_array_len_e2e.rs:+0:43: +0:46
-    let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len_e2e.rs:+0:60: +0:65
-
-    bb0: {
-        _0 = const N;                    // scope 0 at $DIR/lower_array_len_e2e.rs:+1:5: +1:14
-        return;                          // scope 0 at $DIR/lower_array_len_e2e.rs:+2:2: +2:2
-    }
-}
diff --git a/tests/mir-opt/lower_array_len_e2e.rs b/tests/mir-opt/lower_array_len_e2e.rs
deleted file mode 100644
index d8e4e521ee6..00000000000
--- a/tests/mir-opt/lower_array_len_e2e.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-// compile-flags: -Z mir-opt-level=4 -Zunsound-mir-opts
-
-// EMIT_MIR lower_array_len_e2e.array_bound.PreCodegen.after.mir
-pub fn array_bound<const N: usize>(index: usize, slice: &[u8; N]) -> u8 {
-    if index < slice.len() {
-        slice[index]
-    } else {
-        42
-    }
-}
-
-// EMIT_MIR lower_array_len_e2e.array_bound_mut.PreCodegen.after.mir
-pub fn array_bound_mut<const N: usize>(index: usize, slice: &mut [u8; N]) -> u8 {
-    if index < slice.len() {
-        slice[index]
-    } else {
-        slice[0] = 42;
-
-        42
-    }
-}
-
-// EMIT_MIR lower_array_len_e2e.array_len.PreCodegen.after.mir
-pub fn array_len<const N: usize>(arr: &[u8; N]) -> usize {
-    arr.len()
-}
-
-// EMIT_MIR lower_array_len_e2e.array_len_by_value.PreCodegen.after.mir
-pub fn array_len_by_value<const N: usize>(arr: [u8; N]) -> usize {
-    arr.len()
-}
-
-fn main() {
-    let _ = array_bound(3, &[0, 1, 2, 3]);
-    let mut tmp = [0, 1, 2, 3, 4];
-    let _ = array_bound_mut(3, &mut [0, 1, 2, 3]);
-    let _ = array_len(&[0]);
-    let _ = array_len_by_value([0, 2]);
-}
diff --git a/tests/mir-opt/simple_option_map_e2e.ezmap.PreCodegen.after.mir b/tests/mir-opt/simple_option_map_e2e.ezmap.PreCodegen.after.mir
index 916f99049c6..760f48d956d 100644
--- a/tests/mir-opt/simple_option_map_e2e.ezmap.PreCodegen.after.mir
+++ b/tests/mir-opt/simple_option_map_e2e.ezmap.PreCodegen.after.mir
@@ -37,7 +37,7 @@ fn ezmap(_1: Option<i32>) -> Option<i32> {
     bb3: {
         _5 = move ((_1 as Some).0: i32); // scope 1 at $DIR/simple_option_map_e2e.rs:7:14: 7:15
         StorageLive(_4);                 // scope 2 at $DIR/simple_option_map_e2e.rs:7:25: 7:29
-        _4 = Add(move _5, const 1_i32);  // scope 3 at $DIR/simple_option_map_e2e.rs:+1:16: +1:21
+        _4 = Add(_5, const 1_i32);       // scope 3 at $DIR/simple_option_map_e2e.rs:+1:16: +1:21
         Deinit(_0);                      // scope 2 at $DIR/simple_option_map_e2e.rs:7:20: 7:30
         ((_0 as Some).0: i32) = move _4; // scope 2 at $DIR/simple_option_map_e2e.rs:7:20: 7:30
         discriminant(_0) = 1;            // scope 2 at $DIR/simple_option_map_e2e.rs:7:20: 7:30
diff --git a/tests/mir-opt/simplify_match.main.ConstProp.diff b/tests/mir-opt/simplify_match.main.ConstProp.diff
index 70bfbf1b3e3..35ffc4963cb 100644
--- a/tests/mir-opt/simplify_match.main.ConstProp.diff
+++ b/tests/mir-opt/simplify_match.main.ConstProp.diff
@@ -10,13 +10,9 @@
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/simplify_match.rs:+1:11: +1:31
           StorageLive(_2);                 // scope 0 at $DIR/simplify_match.rs:+1:17: +1:18
           _2 = const false;                // scope 0 at $DIR/simplify_match.rs:+1:21: +1:26
--         _1 = _2;                         // scope 1 at $DIR/simplify_match.rs:+1:28: +1:29
-+         _1 = const false;                // scope 1 at $DIR/simplify_match.rs:+1:28: +1:29
-          StorageDead(_2);                 // scope 0 at $DIR/simplify_match.rs:+1:30: +1:31
--         switchInt(_1) -> [0: bb1, otherwise: bb2]; // scope 0 at $DIR/simplify_match.rs:+1:5: +1:31
+-         switchInt(_2) -> [0: bb1, otherwise: bb2]; // scope 0 at $DIR/simplify_match.rs:+1:5: +1:31
 +         switchInt(const false) -> [0: bb1, otherwise: bb2]; // scope 0 at $DIR/simplify_match.rs:+1:5: +1:31
       }
   
@@ -32,7 +28,6 @@
       }
   
       bb3: {
-          StorageDead(_1);                 // scope 0 at $DIR/simplify_match.rs:+5:1: +5:2
           return;                          // scope 0 at $DIR/simplify_match.rs:+5:2: +5:2
       }
   }
diff --git a/tests/mir-opt/slice_filter.rs b/tests/mir-opt/slice_filter.rs
new file mode 100644
index 00000000000..97c18af31de
--- /dev/null
+++ b/tests/mir-opt/slice_filter.rs
@@ -0,0 +1,18 @@
+fn main() {
+    let input = vec![];
+    let _variant_a_result = variant_a(&input);
+    let _variant_b_result = variant_b(&input);
+}
+
+pub fn variant_a(input: &[(usize, usize, usize, usize)]) -> usize {
+    input.iter().filter(|(a, b, c, d)| a <= c && d <= b || c <= a && b <= d).count()
+}
+
+pub fn variant_b(input: &[(usize, usize, usize, usize)]) -> usize {
+    input.iter().filter(|&&(a, b, c, d)| a <= c && d <= b || c <= a && b <= d).count()
+}
+
+// EMIT_MIR slice_filter.variant_a-{closure#0}.CopyProp.diff
+// EMIT_MIR slice_filter.variant_a-{closure#0}.DestinationPropagation.diff
+// EMIT_MIR slice_filter.variant_b-{closure#0}.CopyProp.diff
+// EMIT_MIR slice_filter.variant_b-{closure#0}.DestinationPropagation.diff
diff --git a/tests/mir-opt/slice_filter.variant_a-{closure#0}.CopyProp.diff b/tests/mir-opt/slice_filter.variant_a-{closure#0}.CopyProp.diff
new file mode 100644
index 00000000000..d1f6fd97dc7
--- /dev/null
+++ b/tests/mir-opt/slice_filter.variant_a-{closure#0}.CopyProp.diff
@@ -0,0 +1,279 @@
+- // MIR for `variant_a::{closure#0}` before CopyProp
++ // MIR for `variant_a::{closure#0}` after CopyProp
+  
+  fn variant_a::{closure#0}(_1: &mut [closure@$DIR/slice_filter.rs:8:25: 8:39], _2: &&(usize, usize, usize, usize)) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/slice_filter.rs:+0:40: +0:40
+      let _3: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+      let _4: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+      let _5: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+      let _6: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+      let mut _7: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:56
+      let mut _8: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:46
+      let mut _9: &&usize;                 // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:41
+      let mut _10: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:45: +0:46
+      let _11: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:45: +0:46
+      let mut _12: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:50: +0:56
+      let mut _13: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:50: +0:51
+      let mut _14: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:55: +0:56
+      let _15: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:55: +0:56
+      let mut _16: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:76
+      let mut _17: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:66
+      let mut _18: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:61
+      let mut _19: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:65: +0:66
+      let _20: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:65: +0:66
+      let mut _21: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:70: +0:76
+      let mut _22: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:70: +0:71
+      let mut _23: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+      let _24: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+      let mut _25: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _26: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _27: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _28: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      scope 1 {
+          debug a => _3;                   // in scope 1 at $DIR/slice_filter.rs:+0:27: +0:28
+          debug b => _4;                   // in scope 1 at $DIR/slice_filter.rs:+0:30: +0:31
+          debug c => _5;                   // in scope 1 at $DIR/slice_filter.rs:+0:33: +0:34
+          debug d => _6;                   // in scope 1 at $DIR/slice_filter.rs:+0:36: +0:37
+          scope 2 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:40: 8:46
+              debug self => _9;            // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _10;          // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _29: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _30: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _31: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _32: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 3 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug self => _29;       // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug other => _30;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug self => _31;       // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug other => _32;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _33: usize;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _34: usize;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 4 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:60: 8:66
+              debug self => _18;           // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _19;          // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _35: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _36: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _37: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _38: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 5 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug self => _35;       // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug other => _36;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug self => _37;       // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug other => _38;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _39: usize;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _40: usize;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 6 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:50: 8:56
+              debug self => _13;           // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _14;          // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _41: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _42: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _43: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _44: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 7 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug self => _41;       // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug other => _42;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug self => _43;       // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug other => _44;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _45: usize;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _46: usize;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 8 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:70: 8:76
+              debug self => _22;           // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _23;          // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _47: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _48: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _49: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _50: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 9 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug self => _47;       // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-                 debug other => _48;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug self => _49;       // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
++                 debug other => _50;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _51: usize;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _52: usize;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          _25 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          _3 = &((*_25).0: usize);         // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          StorageLive(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          _26 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          _4 = &((*_26).1: usize);         // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          StorageLive(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          _27 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          _5 = &((*_27).2: usize);         // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          StorageLive(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+          _28 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+          _6 = &((*_28).3: usize);         // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+          StorageLive(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+          StorageLive(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:46
+          StorageLive(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:41
+          _9 = &_3;                        // scope 1 at $DIR/slice_filter.rs:+0:40: +0:41
+          StorageLive(_10);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageLive(_11);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          _11 = _5;                        // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          _10 = &_11;                      // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+-         StorageLive(_29);                // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _31 = deref_copy (*_9);          // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _29 = _31;                       // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageLive(_30);                // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _32 = deref_copy (*_10);         // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _30 = _32;                       // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_33);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _33 = (*_29);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _33 = (*_31);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_34);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _34 = (*_30);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _34 = (*_32);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _8 = Le(move _33, move _34);     // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_34);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_33);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_30);                // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_29);                // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_11);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageDead(_10);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageDead(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          switchInt(move _8) -> [0: bb4, otherwise: bb5]; // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+      }
+  
+      bb1: {
+          _0 = const true;                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  
+      bb2: {
+          StorageLive(_16);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          StorageLive(_17);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:66
+          StorageLive(_18);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:61
+          _18 = &_5;                       // scope 1 at $DIR/slice_filter.rs:+0:60: +0:61
+          StorageLive(_19);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageLive(_20);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          _20 = _3;                        // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          _19 = &_20;                      // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+-         StorageLive(_35);                // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _37 = deref_copy (*_18);         // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _35 = _37;                       // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageLive(_36);                // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _38 = deref_copy (*_19);         // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _36 = _38;                       // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_39);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _39 = (*_35);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _39 = (*_37);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_40);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _40 = (*_36);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _40 = (*_38);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _17 = Le(move _39, move _40);    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_40);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_39);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_36);                // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_35);                // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_20);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageDead(_19);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageDead(_18);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          switchInt(move _17) -> [0: bb6, otherwise: bb7]; // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb3: {
+          StorageDead(_16);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageDead(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageDead(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageDead(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageDead(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+          return;                          // scope 0 at $DIR/slice_filter.rs:+0:76: +0:76
+      }
+  
+      bb4: {
+          _7 = const false;                // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+          StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          goto -> bb2;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+      }
+  
+      bb5: {
+          StorageLive(_12);                // scope 1 at $DIR/slice_filter.rs:+0:50: +0:56
+          StorageLive(_13);                // scope 1 at $DIR/slice_filter.rs:+0:50: +0:51
+          _13 = &_6;                       // scope 1 at $DIR/slice_filter.rs:+0:50: +0:51
+          StorageLive(_14);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageLive(_15);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _15 = _4;                        // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _14 = &_15;                      // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+-         StorageLive(_41);                // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _43 = deref_copy (*_13);         // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _41 = _43;                       // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageLive(_42);                // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _44 = deref_copy (*_14);         // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _42 = _44;                       // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_45);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _45 = (*_41);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _45 = (*_43);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_46);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _46 = (*_42);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _46 = (*_44);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _12 = Le(move _45, move _46);    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_46);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_45);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_42);                // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_41);                // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_15);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_14);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_13);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _7 = move _12;                   // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+          StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          switchInt(move _7) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  
+      bb6: {
+          _16 = const false;               // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb7: {
+          StorageLive(_21);                // scope 1 at $DIR/slice_filter.rs:+0:70: +0:76
+          StorageLive(_22);                // scope 1 at $DIR/slice_filter.rs:+0:70: +0:71
+          _22 = &_4;                       // scope 1 at $DIR/slice_filter.rs:+0:70: +0:71
+          StorageLive(_23);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageLive(_24);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _24 = _6;                        // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _23 = &_24;                      // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageLive(_47);                // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _49 = deref_copy (*_22);         // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _47 = _49;                       // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageLive(_48);                // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _50 = deref_copy (*_23);         // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _48 = _50;                       // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_51);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _51 = (*_47);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _51 = (*_49);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_52);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _52 = (*_48);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _52 = (*_50);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _21 = Le(move _51, move _52);    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_52);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_51);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_48);                // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         StorageDead(_47);                // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_24);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_23);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_22);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _16 = move _21;                  // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb8: {
+          StorageDead(_21);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_17);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _0 = move _16;                   // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  }
+  
diff --git a/tests/mir-opt/slice_filter.variant_a-{closure#0}.DestinationPropagation.diff b/tests/mir-opt/slice_filter.variant_a-{closure#0}.DestinationPropagation.diff
new file mode 100644
index 00000000000..259cd411896
--- /dev/null
+++ b/tests/mir-opt/slice_filter.variant_a-{closure#0}.DestinationPropagation.diff
@@ -0,0 +1,241 @@
+- // MIR for `variant_a::{closure#0}` before DestinationPropagation
++ // MIR for `variant_a::{closure#0}` after DestinationPropagation
+  
+  fn variant_a::{closure#0}(_1: &mut [closure@$DIR/slice_filter.rs:8:25: 8:39], _2: &&(usize, usize, usize, usize)) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/slice_filter.rs:+0:40: +0:40
+      let _3: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+      let _4: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+      let _5: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+      let _6: &usize;                      // in scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+      let mut _7: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:56
+      let mut _8: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:46
+      let mut _9: &&usize;                 // in scope 0 at $DIR/slice_filter.rs:+0:40: +0:41
+      let mut _10: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:45: +0:46
+      let _11: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:45: +0:46
+      let mut _12: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:50: +0:56
+      let mut _13: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:50: +0:51
+      let mut _14: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:55: +0:56
+      let _15: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:55: +0:56
+      let mut _16: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:76
+      let mut _17: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:66
+      let mut _18: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:60: +0:61
+      let mut _19: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:65: +0:66
+      let _20: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:65: +0:66
+      let mut _21: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:70: +0:76
+      let mut _22: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:70: +0:71
+      let mut _23: &&usize;                // in scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+      let _24: &usize;                     // in scope 0 at $DIR/slice_filter.rs:+0:75: +0:76
+      let mut _25: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _26: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _27: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      let mut _28: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:38
+      scope 1 {
+          debug a => _3;                   // in scope 1 at $DIR/slice_filter.rs:+0:27: +0:28
+          debug b => _4;                   // in scope 1 at $DIR/slice_filter.rs:+0:30: +0:31
+          debug c => _5;                   // in scope 1 at $DIR/slice_filter.rs:+0:33: +0:34
+          debug d => _6;                   // in scope 1 at $DIR/slice_filter.rs:+0:36: +0:37
+          scope 2 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:40: 8:46
+              debug self => _9;            // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _10;          // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _29: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _30: &usize;         // in scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 3 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug self => _29;       // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug other => _30;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _31: usize;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _32: usize;      // in scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 4 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:60: 8:66
+              debug self => _18;           // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _19;          // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _33: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _34: &usize;         // in scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 5 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug self => _33;       // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug other => _34;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _35: usize;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _36: usize;      // in scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 6 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:50: 8:56
+              debug self => _13;           // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _14;          // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _37: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _38: &usize;         // in scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 7 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug self => _37;       // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug other => _38;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _39: usize;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _40: usize;      // in scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+          scope 8 (inlined cmp::impls::<impl PartialOrd for &usize>::le) { // at $DIR/slice_filter.rs:8:70: 8:76
+              debug self => _22;           // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              debug other => _23;          // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _41: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              let mut _42: &usize;         // in scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              scope 9 (inlined cmp::impls::<impl PartialOrd for usize>::le) { // at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug self => _41;       // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  debug other => _42;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _43: usize;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+                  let mut _44: usize;      // in scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          _25 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          _3 = &((*_25).0: usize);         // scope 0 at $DIR/slice_filter.rs:+0:27: +0:28
+          StorageLive(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          _26 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          _4 = &((*_26).1: usize);         // scope 0 at $DIR/slice_filter.rs:+0:30: +0:31
+          StorageLive(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          _27 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          _5 = &((*_27).2: usize);         // scope 0 at $DIR/slice_filter.rs:+0:33: +0:34
+          StorageLive(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+          _28 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+          _6 = &((*_28).3: usize);         // scope 0 at $DIR/slice_filter.rs:+0:36: +0:37
+-         StorageLive(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+          StorageLive(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:46
+          StorageLive(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:41
+          _9 = &_3;                        // scope 1 at $DIR/slice_filter.rs:+0:40: +0:41
+          StorageLive(_10);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageLive(_11);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          _11 = _5;                        // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          _10 = &_11;                      // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          _29 = deref_copy (*_9);          // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _30 = deref_copy (*_10);         // scope 2 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_31);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _31 = (*_29);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_32);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _32 = (*_30);                    // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _8 = Le(move _31, move _32);     // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_32);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_31);                // scope 3 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_11);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageDead(_10);                // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          StorageDead(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:45: +0:46
+          switchInt(move _8) -> [0: bb4, otherwise: bb5]; // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+      }
+  
+      bb1: {
+          _0 = const true;                 // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  
+      bb2: {
+-         StorageLive(_16);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          StorageLive(_17);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:66
+          StorageLive(_18);                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:61
+          _18 = &_5;                       // scope 1 at $DIR/slice_filter.rs:+0:60: +0:61
+          StorageLive(_19);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageLive(_20);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          _20 = _3;                        // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          _19 = &_20;                      // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          _33 = deref_copy (*_18);         // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _34 = deref_copy (*_19);         // scope 4 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_35);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _35 = (*_33);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_36);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _36 = (*_34);                    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _17 = Le(move _35, move _36);    // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_36);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_35);                // scope 5 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_20);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageDead(_19);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          StorageDead(_18);                // scope 1 at $DIR/slice_filter.rs:+0:65: +0:66
+          switchInt(move _17) -> [0: bb6, otherwise: bb7]; // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb3: {
+-         StorageDead(_16);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+-         StorageDead(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          return;                          // scope 0 at $DIR/slice_filter.rs:+0:76: +0:76
+      }
+  
+      bb4: {
+-         StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          goto -> bb2;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+      }
+  
+      bb5: {
+-         StorageLive(_12);                // scope 1 at $DIR/slice_filter.rs:+0:50: +0:56
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:50: +0:56
+          StorageLive(_13);                // scope 1 at $DIR/slice_filter.rs:+0:50: +0:51
+          _13 = &_6;                       // scope 1 at $DIR/slice_filter.rs:+0:50: +0:51
+          StorageLive(_14);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageLive(_15);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _15 = _4;                        // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _14 = &_15;                      // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          _37 = deref_copy (*_13);         // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _38 = deref_copy (*_14);         // scope 6 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_39);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _39 = (*_37);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_40);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _40 = (*_38);                    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _12 = Le(move _39, move _40);    // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_40);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_39);                // scope 7 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_15);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_14);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_13);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+-         _7 = move _12;                   // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
+-         StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:40: +0:56
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:55: +0:56
+-         switchInt(move _7) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
++         switchInt(move _12) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  
+      bb6: {
+-         _16 = const false;               // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
++         _0 = const false;                // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb7: {
+-         StorageLive(_21);                // scope 1 at $DIR/slice_filter.rs:+0:70: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:70: +0:76
+          StorageLive(_22);                // scope 1 at $DIR/slice_filter.rs:+0:70: +0:71
+          _22 = &_4;                       // scope 1 at $DIR/slice_filter.rs:+0:70: +0:71
+          StorageLive(_23);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageLive(_24);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _24 = _6;                        // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _23 = &_24;                      // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          _41 = deref_copy (*_22);         // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _42 = deref_copy (*_23);         // scope 8 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_43);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _43 = (*_41);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageLive(_44);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          _44 = (*_42);                    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+-         _21 = Le(move _43, move _44);    // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
++         _0 = Le(move _43, move _44);     // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_44);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_43);                // scope 9 at $SRC_DIR/core/src/cmp.rs:LL:COL
+          StorageDead(_24);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_23);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_22);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+-         _16 = move _21;                  // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:60: +0:76
+      }
+  
+      bb8: {
+-         StorageDead(_21);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+          StorageDead(_17);                // scope 1 at $DIR/slice_filter.rs:+0:75: +0:76
+-         _0 = move _16;                   // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:40: +0:76
+      }
+  }
+  
diff --git a/tests/mir-opt/slice_filter.variant_b-{closure#0}.CopyProp.diff b/tests/mir-opt/slice_filter.variant_b-{closure#0}.CopyProp.diff
new file mode 100644
index 00000000000..c3b8e7d2eba
--- /dev/null
+++ b/tests/mir-opt/slice_filter.variant_b-{closure#0}.CopyProp.diff
@@ -0,0 +1,139 @@
+- // MIR for `variant_b::{closure#0}` before CopyProp
++ // MIR for `variant_b::{closure#0}` after CopyProp
+  
+  fn variant_b::{closure#0}(_1: &mut [closure@$DIR/slice_filter.rs:12:25: 12:41], _2: &&(usize, usize, usize, usize)) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/slice_filter.rs:+0:42: +0:42
+      let _3: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+      let _4: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+      let _5: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+      let _6: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+      let mut _7: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:42: +0:58
+      let mut _8: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:42: +0:48
+      let mut _9: usize;                   // in scope 0 at $DIR/slice_filter.rs:+0:42: +0:43
+      let mut _10: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:47: +0:48
+      let mut _11: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:52: +0:58
+      let mut _12: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:52: +0:53
+      let mut _13: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:57: +0:58
+      let mut _14: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:62: +0:78
+      let mut _15: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:62: +0:68
+      let mut _16: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:62: +0:63
+      let mut _17: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:67: +0:68
+      let mut _18: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:72: +0:78
+      let mut _19: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:72: +0:73
+      let mut _20: usize;                  // in scope 0 at $DIR/slice_filter.rs:+0:77: +0:78
+      let mut _21: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _22: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _23: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _24: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      scope 1 {
+          debug a => _3;                   // in scope 1 at $DIR/slice_filter.rs:+0:29: +0:30
+          debug b => _4;                   // in scope 1 at $DIR/slice_filter.rs:+0:32: +0:33
+          debug c => _5;                   // in scope 1 at $DIR/slice_filter.rs:+0:35: +0:36
+          debug d => _6;                   // in scope 1 at $DIR/slice_filter.rs:+0:38: +0:39
+      }
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          _21 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          _3 = ((*_21).0: usize);          // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          StorageLive(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          _22 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          _4 = ((*_22).1: usize);          // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          StorageLive(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          _23 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          _5 = ((*_23).2: usize);          // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          StorageLive(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+          _24 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+          _6 = ((*_24).3: usize);          // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+          StorageLive(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+          StorageLive(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:48
+-         StorageLive(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:43
+-         _9 = _3;                         // scope 1 at $DIR/slice_filter.rs:+0:42: +0:43
+-         StorageLive(_10);                // scope 1 at $DIR/slice_filter.rs:+0:47: +0:48
+-         _10 = _5;                        // scope 1 at $DIR/slice_filter.rs:+0:47: +0:48
+-         _8 = Le(move _9, move _10);      // scope 1 at $DIR/slice_filter.rs:+0:42: +0:48
+-         StorageDead(_10);                // scope 1 at $DIR/slice_filter.rs:+0:47: +0:48
+-         StorageDead(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:47: +0:48
++         _8 = Le(_3, _5);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:48
+          switchInt(move _8) -> [0: bb4, otherwise: bb5]; // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+      }
+  
+      bb1: {
+          _0 = const true;                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  
+      bb2: {
+          StorageLive(_14);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          StorageLive(_15);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:68
+-         StorageLive(_16);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:63
+-         _16 = _5;                        // scope 1 at $DIR/slice_filter.rs:+0:62: +0:63
+-         StorageLive(_17);                // scope 1 at $DIR/slice_filter.rs:+0:67: +0:68
+-         _17 = _3;                        // scope 1 at $DIR/slice_filter.rs:+0:67: +0:68
+-         _15 = Le(move _16, move _17);    // scope 1 at $DIR/slice_filter.rs:+0:62: +0:68
+-         StorageDead(_17);                // scope 1 at $DIR/slice_filter.rs:+0:67: +0:68
+-         StorageDead(_16);                // scope 1 at $DIR/slice_filter.rs:+0:67: +0:68
++         _15 = Le(_5, _3);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:68
+          switchInt(move _15) -> [0: bb6, otherwise: bb7]; // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb3: {
+          StorageDead(_14);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+          StorageDead(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:77: +0:78
+          return;                          // scope 0 at $DIR/slice_filter.rs:+0:78: +0:78
+      }
+  
+      bb4: {
+          _7 = const false;                // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+          StorageDead(_11);                // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          goto -> bb2;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+      }
+  
+      bb5: {
+          StorageLive(_11);                // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
+-         StorageLive(_12);                // scope 1 at $DIR/slice_filter.rs:+0:52: +0:53
+-         _12 = _6;                        // scope 1 at $DIR/slice_filter.rs:+0:52: +0:53
+-         StorageLive(_13);                // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+-         _13 = _4;                        // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+-         _11 = Le(move _12, move _13);    // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
+-         StorageDead(_13);                // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+-         StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
++         _11 = Le(_6, _4);                // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
+          _7 = move _11;                   // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+          StorageDead(_11);                // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          switchInt(move _7) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  
+      bb6: {
+          _14 = const false;               // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb7: {
+          StorageLive(_18);                // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
+-         StorageLive(_19);                // scope 1 at $DIR/slice_filter.rs:+0:72: +0:73
+-         _19 = _4;                        // scope 1 at $DIR/slice_filter.rs:+0:72: +0:73
+-         StorageLive(_20);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         _20 = _6;                        // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         _18 = Le(move _19, move _20);    // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
+-         StorageDead(_20);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_19);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
++         _18 = Le(_4, _6);                // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
+          _14 = move _18;                  // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb8: {
+          StorageDead(_18);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+          StorageDead(_15);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+          _0 = move _14;                   // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  }
+  
diff --git a/tests/mir-opt/slice_filter.variant_b-{closure#0}.DestinationPropagation.diff b/tests/mir-opt/slice_filter.variant_b-{closure#0}.DestinationPropagation.diff
new file mode 100644
index 00000000000..a43e84d29c7
--- /dev/null
+++ b/tests/mir-opt/slice_filter.variant_b-{closure#0}.DestinationPropagation.diff
@@ -0,0 +1,113 @@
+- // MIR for `variant_b::{closure#0}` before DestinationPropagation
++ // MIR for `variant_b::{closure#0}` after DestinationPropagation
+  
+  fn variant_b::{closure#0}(_1: &mut [closure@$DIR/slice_filter.rs:12:25: 12:41], _2: &&(usize, usize, usize, usize)) -> bool {
+      let mut _0: bool;                    // return place in scope 0 at $DIR/slice_filter.rs:+0:42: +0:42
+      let _3: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+      let _4: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+      let _5: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+      let _6: usize;                       // in scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+      let mut _7: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:42: +0:58
+      let mut _8: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:42: +0:48
+      let mut _9: bool;                    // in scope 0 at $DIR/slice_filter.rs:+0:52: +0:58
+      let mut _10: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:62: +0:78
+      let mut _11: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:62: +0:68
+      let mut _12: bool;                   // in scope 0 at $DIR/slice_filter.rs:+0:72: +0:78
+      let mut _13: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _14: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _15: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      let mut _16: &(usize, usize, usize, usize); // in scope 0 at $DIR/slice_filter.rs:+0:26: +0:40
+      scope 1 {
+          debug a => _3;                   // in scope 1 at $DIR/slice_filter.rs:+0:29: +0:30
+          debug b => _4;                   // in scope 1 at $DIR/slice_filter.rs:+0:32: +0:33
+          debug c => _5;                   // in scope 1 at $DIR/slice_filter.rs:+0:35: +0:36
+          debug d => _6;                   // in scope 1 at $DIR/slice_filter.rs:+0:38: +0:39
+      }
+  
+      bb0: {
+          StorageLive(_3);                 // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          _13 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          _3 = ((*_13).0: usize);          // scope 0 at $DIR/slice_filter.rs:+0:29: +0:30
+          StorageLive(_4);                 // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          _14 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          _4 = ((*_14).1: usize);          // scope 0 at $DIR/slice_filter.rs:+0:32: +0:33
+          StorageLive(_5);                 // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          _15 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          _5 = ((*_15).2: usize);          // scope 0 at $DIR/slice_filter.rs:+0:35: +0:36
+          StorageLive(_6);                 // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+          _16 = deref_copy (*_2);          // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+          _6 = ((*_16).3: usize);          // scope 0 at $DIR/slice_filter.rs:+0:38: +0:39
+-         StorageLive(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+          StorageLive(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:48
+          _8 = Le(_3, _5);                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:48
+          switchInt(move _8) -> [0: bb4, otherwise: bb5]; // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+      }
+  
+      bb1: {
+          _0 = const true;                 // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  
+      bb2: {
+-         StorageLive(_10);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          StorageLive(_11);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:68
+          _11 = Le(_5, _3);                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:68
+          switchInt(move _11) -> [0: bb6, otherwise: bb7]; // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb3: {
+-         StorageDead(_10);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         StorageDead(_7);                 // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+          return;                          // scope 0 at $DIR/slice_filter.rs:+0:78: +0:78
+      }
+  
+      bb4: {
+-         StorageDead(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          goto -> bb2;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+      }
+  
+      bb5: {
+-         StorageLive(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
+          _9 = Le(_6, _4);                 // scope 1 at $DIR/slice_filter.rs:+0:52: +0:58
+-         _7 = move _9;                    // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
+-         StorageDead(_9);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:42: +0:58
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+          StorageDead(_8);                 // scope 1 at $DIR/slice_filter.rs:+0:57: +0:58
+-         switchInt(move _7) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
++         switchInt(move _9) -> [0: bb2, otherwise: bb1]; // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  
+      bb6: {
+-         _10 = const false;               // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
++         _0 = const false;                // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb7: {
+-         StorageLive(_12);                // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
+-         _12 = Le(_4, _6);                // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
+-         _10 = move _12;                  // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
++         _0 = Le(_4, _6);                 // scope 1 at $DIR/slice_filter.rs:+0:72: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+          goto -> bb8;                     // scope 1 at $DIR/slice_filter.rs:+0:62: +0:78
+      }
+  
+      bb8: {
+-         StorageDead(_12);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+          StorageDead(_11);                // scope 1 at $DIR/slice_filter.rs:+0:77: +0:78
+-         _0 = move _10;                   // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
++         nop;                             // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+          goto -> bb3;                     // scope 1 at $DIR/slice_filter.rs:+0:42: +0:78
+      }
+  }
+  
diff --git a/tests/mir-opt/try_identity_e2e.new.PreCodegen.after.mir b/tests/mir-opt/try_identity_e2e.new.PreCodegen.after.mir
index b254bfeb7c9..7c67d2abcf7 100644
--- a/tests/mir-opt/try_identity_e2e.new.PreCodegen.after.mir
+++ b/tests/mir-opt/try_identity_e2e.new.PreCodegen.after.mir
@@ -5,11 +5,11 @@ fn new(_1: Result<T, E>) -> Result<T, E> {
     let mut _0: std::result::Result<T, E>; // return place in scope 0 at $DIR/try_identity_e2e.rs:+0:34: +0:46
     let mut _2: std::ops::ControlFlow<E, T>; // in scope 0 at $DIR/try_identity_e2e.rs:+2:15: +7:10
     let mut _3: isize;                   // in scope 0 at $DIR/try_identity_e2e.rs:+4:17: +4:22
-    let mut _4: T;                       // in scope 0 at $DIR/try_identity_e2e.rs:+4:48: +4:49
-    let mut _5: E;                       // in scope 0 at $DIR/try_identity_e2e.rs:+5:46: +5:47
+    let _4: T;                           // in scope 0 at $DIR/try_identity_e2e.rs:+4:20: +4:21
+    let _5: E;                           // in scope 0 at $DIR/try_identity_e2e.rs:+5:21: +5:22
     let mut _6: isize;                   // in scope 0 at $DIR/try_identity_e2e.rs:+8:13: +8:37
     let _7: T;                           // in scope 0 at $DIR/try_identity_e2e.rs:+8:35: +8:36
-    let mut _8: E;                       // in scope 0 at $DIR/try_identity_e2e.rs:+9:49: +9:50
+    let _8: E;                           // in scope 0 at $DIR/try_identity_e2e.rs:+9:32: +9:33
     scope 1 {
         debug v => _4;                   // in scope 1 at $DIR/try_identity_e2e.rs:+4:20: +4:21
     }
@@ -30,6 +30,7 @@ fn new(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb1: {
+        StorageLive(_5);                 // scope 0 at $DIR/try_identity_e2e.rs:+5:21: +5:22
         _5 = move ((_1 as Err).0: E);    // scope 0 at $DIR/try_identity_e2e.rs:+5:21: +5:22
         Deinit(_2);                      // scope 2 at $DIR/try_identity_e2e.rs:+5:27: +5:48
         ((_2 as Break).0: E) = move _5;  // scope 2 at $DIR/try_identity_e2e.rs:+5:27: +5:48
@@ -39,6 +40,7 @@ fn new(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb2: {
+        StorageLive(_4);                 // scope 0 at $DIR/try_identity_e2e.rs:+4:20: +4:21
         _4 = move ((_1 as Ok).0: T);     // scope 0 at $DIR/try_identity_e2e.rs:+4:20: +4:21
         Deinit(_2);                      // scope 1 at $DIR/try_identity_e2e.rs:+4:26: +4:50
         ((_2 as Continue).0: T) = move _4; // scope 1 at $DIR/try_identity_e2e.rs:+4:26: +4:50
@@ -48,6 +50,7 @@ fn new(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb3: {
+        StorageLive(_8);                 // scope 0 at $DIR/try_identity_e2e.rs:+9:32: +9:33
         _8 = move ((_2 as Break).0: E);  // scope 0 at $DIR/try_identity_e2e.rs:+9:32: +9:33
         Deinit(_0);                      // scope 4 at $DIR/try_identity_e2e.rs:+9:45: +9:51
         ((_0 as Err).0: E) = move _8;    // scope 4 at $DIR/try_identity_e2e.rs:+9:45: +9:51
@@ -61,6 +64,7 @@ fn new(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb5: {
+        StorageLive(_7);                 // scope 0 at $DIR/try_identity_e2e.rs:+8:35: +8:36
         _7 = move ((_2 as Continue).0: T); // scope 0 at $DIR/try_identity_e2e.rs:+8:35: +8:36
         Deinit(_0);                      // scope 0 at $DIR/try_identity_e2e.rs:+1:5: +11:6
         ((_0 as Ok).0: T) = move _7;     // scope 0 at $DIR/try_identity_e2e.rs:+1:5: +11:6
diff --git a/tests/mir-opt/try_identity_e2e.old.PreCodegen.after.mir b/tests/mir-opt/try_identity_e2e.old.PreCodegen.after.mir
index cdbc0681cb8..4a838e14026 100644
--- a/tests/mir-opt/try_identity_e2e.old.PreCodegen.after.mir
+++ b/tests/mir-opt/try_identity_e2e.old.PreCodegen.after.mir
@@ -5,7 +5,7 @@ fn old(_1: Result<T, E>) -> Result<T, E> {
     let mut _0: std::result::Result<T, E>; // return place in scope 0 at $DIR/try_identity_e2e.rs:+0:34: +0:46
     let mut _2: isize;                   // in scope 0 at $DIR/try_identity_e2e.rs:+3:13: +3:18
     let _3: T;                           // in scope 0 at $DIR/try_identity_e2e.rs:+3:16: +3:17
-    let mut _4: E;                       // in scope 0 at $DIR/try_identity_e2e.rs:+4:34: +4:35
+    let _4: E;                           // in scope 0 at $DIR/try_identity_e2e.rs:+4:17: +4:18
     scope 1 {
         debug v => _3;                   // in scope 1 at $DIR/try_identity_e2e.rs:+3:16: +3:17
     }
@@ -19,6 +19,7 @@ fn old(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb1: {
+        StorageLive(_4);                 // scope 0 at $DIR/try_identity_e2e.rs:+4:17: +4:18
         _4 = move ((_1 as Err).0: E);    // scope 0 at $DIR/try_identity_e2e.rs:+4:17: +4:18
         Deinit(_0);                      // scope 2 at $DIR/try_identity_e2e.rs:+4:30: +4:36
         ((_0 as Err).0: E) = move _4;    // scope 2 at $DIR/try_identity_e2e.rs:+4:30: +4:36
@@ -31,6 +32,7 @@ fn old(_1: Result<T, E>) -> Result<T, E> {
     }
 
     bb3: {
+        StorageLive(_3);                 // scope 0 at $DIR/try_identity_e2e.rs:+3:16: +3:17
         _3 = move ((_1 as Ok).0: T);     // scope 0 at $DIR/try_identity_e2e.rs:+3:16: +3:17
         Deinit(_0);                      // scope 0 at $DIR/try_identity_e2e.rs:+1:5: +6:6
         ((_0 as Ok).0: T) = move _3;     // scope 0 at $DIR/try_identity_e2e.rs:+1:5: +6:6
diff --git a/tests/mir-opt/while_storage.while_loop.PreCodegen.after.mir b/tests/mir-opt/while_storage.while_loop.PreCodegen.after.mir
index b95d91b13dd..318119bd477 100644
--- a/tests/mir-opt/while_storage.while_loop.PreCodegen.after.mir
+++ b/tests/mir-opt/while_storage.while_loop.PreCodegen.after.mir
@@ -4,9 +4,7 @@ fn while_loop(_1: bool) -> () {
     debug c => _1;                       // in scope 0 at $DIR/while_storage.rs:+0:15: +0:16
     let mut _0: ();                      // return place in scope 0 at $DIR/while_storage.rs:+0:24: +0:24
     let mut _2: bool;                    // in scope 0 at $DIR/while_storage.rs:+1:11: +1:22
-    let mut _3: bool;                    // in scope 0 at $DIR/while_storage.rs:+1:20: +1:21
-    let mut _4: bool;                    // in scope 0 at $DIR/while_storage.rs:+2:12: +2:23
-    let mut _5: bool;                    // in scope 0 at $DIR/while_storage.rs:+2:21: +2:22
+    let mut _3: bool;                    // in scope 0 at $DIR/while_storage.rs:+2:12: +2:23
 
     bb0: {
         goto -> bb1;                     // scope 0 at $DIR/while_storage.rs:+1:5: +5:6
@@ -14,41 +12,35 @@ fn while_loop(_1: bool) -> () {
 
     bb1: {
         StorageLive(_2);                 // scope 0 at $DIR/while_storage.rs:+1:11: +1:22
-        StorageLive(_3);                 // scope 0 at $DIR/while_storage.rs:+1:20: +1:21
-        _3 = _1;                         // scope 0 at $DIR/while_storage.rs:+1:20: +1:21
-        _2 = get_bool(move _3) -> bb2;   // scope 0 at $DIR/while_storage.rs:+1:11: +1:22
+        _2 = get_bool(_1) -> bb2;        // scope 0 at $DIR/while_storage.rs:+1:11: +1:22
                                          // mir::Constant
                                          // + span: $DIR/while_storage.rs:10:11: 10:19
                                          // + literal: Const { ty: fn(bool) -> bool {get_bool}, val: Value(<ZST>) }
     }
 
     bb2: {
-        StorageDead(_3);                 // scope 0 at $DIR/while_storage.rs:+1:21: +1:22
         switchInt(move _2) -> [0: bb7, otherwise: bb3]; // scope 0 at $DIR/while_storage.rs:+1:11: +1:22
     }
 
     bb3: {
-        StorageLive(_4);                 // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
-        StorageLive(_5);                 // scope 0 at $DIR/while_storage.rs:+2:21: +2:22
-        _5 = _1;                         // scope 0 at $DIR/while_storage.rs:+2:21: +2:22
-        _4 = get_bool(move _5) -> bb4;   // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
+        StorageLive(_3);                 // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
+        _3 = get_bool(_1) -> bb4;        // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
                                          // mir::Constant
                                          // + span: $DIR/while_storage.rs:11:12: 11:20
                                          // + literal: Const { ty: fn(bool) -> bool {get_bool}, val: Value(<ZST>) }
     }
 
     bb4: {
-        StorageDead(_5);                 // scope 0 at $DIR/while_storage.rs:+2:22: +2:23
-        switchInt(move _4) -> [0: bb6, otherwise: bb5]; // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
+        switchInt(move _3) -> [0: bb6, otherwise: bb5]; // scope 0 at $DIR/while_storage.rs:+2:12: +2:23
     }
 
     bb5: {
-        StorageDead(_4);                 // scope 0 at $DIR/while_storage.rs:+4:9: +4:10
+        StorageDead(_3);                 // scope 0 at $DIR/while_storage.rs:+4:9: +4:10
         goto -> bb7;                     // scope 0 at no-location
     }
 
     bb6: {
-        StorageDead(_4);                 // scope 0 at $DIR/while_storage.rs:+4:9: +4:10
+        StorageDead(_3);                 // scope 0 at $DIR/while_storage.rs:+4:9: +4:10
         StorageDead(_2);                 // scope 0 at $DIR/while_storage.rs:+5:5: +5:6
         goto -> bb1;                     // scope 0 at $DIR/while_storage.rs:+1:5: +5:6
     }
diff --git a/tests/pretty/dollar-crate.pp b/tests/pretty/dollar-crate.pp
index 3af37955f23..60fddb630d9 100644
--- a/tests/pretty/dollar-crate.pp
+++ b/tests/pretty/dollar-crate.pp
@@ -8,6 +8,4 @@ extern crate std;
 // pretty-mode:expanded
 // pp-exact:dollar-crate.pp
 
-fn main() {
-    { ::std::io::_print(::core::fmt::Arguments::new_v1(&["rust\n"], &[])); };
-}
+fn main() { { ::std::io::_print(format_args!("rust\n")); }; }
diff --git a/tests/pretty/issue-4264.pp b/tests/pretty/issue-4264.pp
index 18e6d75b1d5..e0fa1fe2824 100644
--- a/tests/pretty/issue-4264.pp
+++ b/tests/pretty/issue-4264.pp
@@ -32,12 +32,13 @@ fn bar() ({
         ({
                 let res =
                     ((::alloc::fmt::format as
-                            for<'a> fn(Arguments<'a>) -> String {format})(((::core::fmt::Arguments::new_v1
+                            for<'a> fn(Arguments<'a>) -> String {format})(((<#[lang = "format_arguments"]>::new_v1
                                 as
-                                fn(&[&'static str], &[ArgumentV1<'_>]) -> Arguments<'_> {Arguments::<'_>::new_v1})((&([("test"
+                                fn(&[&'static str], &[core::fmt::ArgumentV1<'_>]) -> Arguments<'_> {Arguments::<'_>::new_v1})((&([("test"
                                             as &str)] as [&str; 1]) as &[&str; 1]),
-                            (&([] as [ArgumentV1<'_>; 0]) as &[ArgumentV1<'_>; 0])) as
-                            Arguments<'_>)) as String);
+                            (&([] as [core::fmt::ArgumentV1<'_>; 0]) as
+                                &[core::fmt::ArgumentV1<'_>; 0])) as Arguments<'_>)) as
+                        String);
                 (res as String)
             } as String);
     } as ())
diff --git a/tests/run-make-fulldeps/split-debuginfo/Makefile b/tests/run-make-fulldeps/split-debuginfo/Makefile
index 1831ab38fab..44cda0d3d11 100644
--- a/tests/run-make-fulldeps/split-debuginfo/Makefile
+++ b/tests/run-make-fulldeps/split-debuginfo/Makefile
@@ -254,12 +254,12 @@ unpacked-remapped-single:
 	$(RUSTC) $(UNSTABLEOPTS) -C split-debuginfo=unpacked -C debuginfo=2 \
 		-Z split-dwarf-kind=single --remap-path-prefix $(TMPDIR)=/a foo.rs -g
 	objdump -Wi $(TMPDIR)/foo | grep DW_AT_GNU_dwo_name | (! grep $(TMPDIR)) || exit 1
-	ls $(TMPDIR)/*.o
+	rm $(TMPDIR)/*.o
 	ls $(TMPDIR)/*.dwo && exit 1 || exit 0
 	ls $(TMPDIR)/*.dwp && exit 1 || exit 0
 	rm $(TMPDIR)/$(call BIN,foo)
 
-unpacked-crosscrate: packed-crosscrate-split packed-crosscrate-single
+unpacked-crosscrate: unpacked-crosscrate-split unpacked-crosscrate-single
 
 # - Debuginfo in `.dwo` files
 # - (bar) `.rlib` file created, contains `.dwo`
diff --git a/tests/run-make/native-link-modifier-bundle/Makefile b/tests/run-make/native-link-modifier-bundle/Makefile
index 7c78d7783e0..e8a1121bfcd 100644
--- a/tests/run-make/native-link-modifier-bundle/Makefile
+++ b/tests/run-make/native-link-modifier-bundle/Makefile
@@ -5,7 +5,12 @@ include ../../run-make-fulldeps/tools.mk
 
 # We're using the llvm-nm instead of the system nm to ensure it is compatible
 # with the LLVM bitcode generated by rustc.
+# Except on Windows where piping/IO redirection under MSYS2 is wonky with llvm-nm.
+ifndef IS_WINDOWS
 NM = "$(LLVM_BIN_DIR)"/llvm-nm
+else
+NM = nm
+endif
 
 all: $(call NATIVE_STATICLIB,native-staticlib)
 	# Build a staticlib and a rlib, the `native_func` symbol will be bundled into them
diff --git a/tests/run-make/overwrite-input/Makefile b/tests/run-make/overwrite-input/Makefile
new file mode 100644
index 00000000000..03b03eb147d
--- /dev/null
+++ b/tests/run-make/overwrite-input/Makefile
@@ -0,0 +1,13 @@
+include ../../run-make-fulldeps/tools.mk
+
+all:
+	$(RUSTC) main.rs -o main.rs 2> $(TMPDIR)/file.stderr || echo "failed successfully"
+	$(RUSTC) main.rs -o . 2> $(TMPDIR)/folder.stderr || echo "failed successfully"
+
+ifdef RUSTC_BLESS_TEST
+	cp "$(TMPDIR)"/file.stderr file.stderr
+	cp "$(TMPDIR)"/folder.stderr folder.stderr
+else
+	$(DIFF) file.stderr "$(TMPDIR)"/file.stderr
+	$(DIFF) folder.stderr "$(TMPDIR)"/folder.stderr
+endif
diff --git a/tests/run-make/overwrite-input/file.stderr b/tests/run-make/overwrite-input/file.stderr
new file mode 100644
index 00000000000..9936962b4ee
--- /dev/null
+++ b/tests/run-make/overwrite-input/file.stderr
@@ -0,0 +1,6 @@
+warning: ignoring --out-dir flag due to -o flag
+
+error: the input file "main.rs" would be overwritten by the generated executable
+
+error: aborting due to previous error; 1 warning emitted
+
diff --git a/tests/run-make/overwrite-input/folder.stderr b/tests/run-make/overwrite-input/folder.stderr
new file mode 100644
index 00000000000..81b1e7367c7
--- /dev/null
+++ b/tests/run-make/overwrite-input/folder.stderr
@@ -0,0 +1,6 @@
+warning: ignoring --out-dir flag due to -o flag
+
+error: the generated executable for the input file "main.rs" conflicts with the existing directory "."
+
+error: aborting due to previous error; 1 warning emitted
+
diff --git a/tests/run-make/overwrite-input/main.rs b/tests/run-make/overwrite-input/main.rs
new file mode 100644
index 00000000000..f328e4d9d04
--- /dev/null
+++ b/tests/run-make/overwrite-input/main.rs
@@ -0,0 +1 @@
+fn main() {}
diff --git a/tests/run-make/overwrite-input/main.stderr b/tests/run-make/overwrite-input/main.stderr
new file mode 100644
index 00000000000..9936962b4ee
--- /dev/null
+++ b/tests/run-make/overwrite-input/main.stderr
@@ -0,0 +1,6 @@
+warning: ignoring --out-dir flag due to -o flag
+
+error: the input file "main.rs" would be overwritten by the generated executable
+
+error: aborting due to previous error; 1 warning emitted
+
diff --git a/tests/run-make/raw-dylib-inline-cross-dylib/Makefile b/tests/run-make/raw-dylib-inline-cross-dylib/Makefile
index 9e603f95835..722a49b02cb 100644
--- a/tests/run-make/raw-dylib-inline-cross-dylib/Makefile
+++ b/tests/run-make/raw-dylib-inline-cross-dylib/Makefile
@@ -4,15 +4,19 @@
 
 include ../../run-make-fulldeps/tools.mk
 
+# We'd be using the llvm-objdump instead of the system objdump to ensure compatibility
+# with the LLVM bitcode generated by rustc but on Windows  piping/IO redirection under MSYS2 is wonky with llvm-objdump.
+OBJDUMP = objdump
+
 all:
 	$(RUSTC) --crate-type dylib --crate-name raw_dylib_test lib.rs -C prefer-dynamic
 	$(RUSTC) --crate-type dylib --crate-name raw_dylib_test_wrapper lib_wrapper.rs -C prefer-dynamic
 	$(RUSTC) --crate-type bin driver.rs -L "$(TMPDIR)" -C prefer-dynamic
 	# Make sure we don't find an import to the functions we expect to be inlined.
-	"$(LLVM_BIN_DIR)"/llvm-objdump -p $(TMPDIR)/driver.exe | $(CGREP) -v -e "inline_library_function"
-	"$(LLVM_BIN_DIR)"/llvm-objdump -p $(TMPDIR)/driver.exe | $(CGREP) -v -e "inline_library_function_calls_inline"
+	$(OBJDUMP) -p $(TMPDIR)/driver.exe | $(CGREP) -v -e "inline_library_function"
+	$(OBJDUMP) -p $(TMPDIR)/driver.exe | $(CGREP) -v -e "inline_library_function_calls_inline"
 	# Make sure we do find an import to the functions we expect to be imported.
-	"$(LLVM_BIN_DIR)"/llvm-objdump -p $(TMPDIR)/driver.exe | $(CGREP) -e "library_function"
+	$(OBJDUMP) -p $(TMPDIR)/driver.exe | $(CGREP) -e "library_function"
 	$(call COMPILE_OBJ,"$(TMPDIR)"/extern_1.obj,extern_1.c)
 	$(call COMPILE_OBJ,"$(TMPDIR)"/extern_2.obj,extern_2.c)
 ifdef IS_MSVC
diff --git a/tests/run-make/rlib-format-packed-bundled-libs-2/Makefile b/tests/run-make/rlib-format-packed-bundled-libs-2/Makefile
index 4574cf17f0e..37b8d809a27 100644
--- a/tests/run-make/rlib-format-packed-bundled-libs-2/Makefile
+++ b/tests/run-make/rlib-format-packed-bundled-libs-2/Makefile
@@ -6,7 +6,12 @@
 
 # We're using the llvm-nm instead of the system nm to ensure it is compatible
 # with the LLVM bitcode generated by rustc.
+# Except on Windows where piping/IO redirection under MSYS2 is wonky with llvm-nm.
+ifndef IS_WINDOWS
 NM = "$(LLVM_BIN_DIR)"/llvm-nm
+else
+NM = nm
+endif
 
 all:
 	# Build strange-named dep.
diff --git a/tests/run-make/rlib-format-packed-bundled-libs/Makefile b/tests/run-make/rlib-format-packed-bundled-libs/Makefile
index 0b991ac42e3..7fb6ce8d1e4 100644
--- a/tests/run-make/rlib-format-packed-bundled-libs/Makefile
+++ b/tests/run-make/rlib-format-packed-bundled-libs/Makefile
@@ -6,7 +6,12 @@
 
 # We're using the llvm-nm instead of the system nm to ensure it is compatible
 # with the LLVM bitcode generated by rustc.
+# Except on Windows where piping/IO redirection under MSYS2 is wonky with llvm-nm.
+ifndef IS_WINDOWS
 NM = "$(LLVM_BIN_DIR)"/llvm-nm
+else
+NM = nm
+endif
 
 all: $(call NATIVE_STATICLIB,native_dep_1) $(call NATIVE_STATICLIB,native_dep_2) $(call NATIVE_STATICLIB,native_dep_3)
 	$(RUSTC) rust_dep_up.rs --crate-type=rlib -Zpacked_bundled_libs
diff --git a/tests/rustdoc-gui/label-next-to-symbol.goml b/tests/rustdoc-gui/label-next-to-symbol.goml
index 05f8ddc716e..3f4f65890b4 100644
--- a/tests/rustdoc-gui/label-next-to-symbol.goml
+++ b/tests/rustdoc-gui/label-next-to-symbol.goml
@@ -20,7 +20,7 @@ assert-css: (
 // table like view
 assert-css: (".item-right.docblock-short", { "padding-left": "0px" })
 compare-elements-position-near: (
-    "//*[@class='item-left module-item']//a[text()='replaced_function']",
+    "//*[@class='item-left']//a[text()='replaced_function']",
     ".item-left .stab.deprecated",
     {"y": 2},
 )
@@ -32,7 +32,7 @@ compare-elements-position: (
 
 // Ensure no wrap
 compare-elements-position: (
-    "//*[@class='item-left module-item']//a[text()='replaced_function']/..",
+    "//*[@class='item-left']//a[text()='replaced_function']/..",
     "//*[@class='item-right docblock-short'][text()='a thing with a label']",
     ("y"),
 )
@@ -43,7 +43,7 @@ size: (600, 600)
 // staggered layout with 2em spacing
 assert-css: (".item-right.docblock-short", { "padding-left": "32px" })
 compare-elements-position-near: (
-    "//*[@class='item-left module-item']//a[text()='replaced_function']",
+    "//*[@class='item-left']//a[text()='replaced_function']",
     ".item-left .stab.deprecated",
     {"y": 2},
 )
@@ -55,7 +55,7 @@ compare-elements-position: (
 
 // Ensure wrap
 compare-elements-position-false: (
-    "//*[@class='item-left module-item']//a[text()='replaced_function']/..",
+    "//*[@class='item-left']//a[text()='replaced_function']/..",
     "//*[@class='item-right docblock-short'][text()='a thing with a label']",
     ("y"),
 )
diff --git a/tests/rustdoc-gui/mobile.goml b/tests/rustdoc-gui/mobile.goml
index 895864d8944..3e444cbd6dc 100644
--- a/tests/rustdoc-gui/mobile.goml
+++ b/tests/rustdoc-gui/mobile.goml
@@ -28,7 +28,7 @@ goto: "file://" + |DOC_PATH| + "/settings.html"
 size: (400, 600)
 // Ignored for now https://github.com/rust-lang/rust/issues/93784.
 // compare-elements-position-near-false: (
-//     "#preferred-light-theme .setting-name",
-//     "#preferred-light-theme .choice",
+//     "#preferred-light-theme .setting-radio-name",
+//     "#preferred-light-theme .setting-radio",
 //     {"y": 16},
 // )
diff --git a/tests/rustdoc-gui/module-items-font.goml b/tests/rustdoc-gui/module-items-font.goml
index cd3676a9871..5940962a8dd 100644
--- a/tests/rustdoc-gui/module-items-font.goml
+++ b/tests/rustdoc-gui/module-items-font.goml
@@ -1,7 +1,7 @@
 // This test checks that the correct font is used on module items (in index.html pages).
 goto: "file://" + |DOC_PATH| + "/test_docs/index.html"
 assert-css: (
-    ".item-table .module-item a",
+    ".item-table .item-left > a",
     {"font-family": '"Fira Sans", Arial, NanumBarunGothic, sans-serif'},
     ALL,
 )
diff --git a/tests/rustdoc-gui/settings.goml b/tests/rustdoc-gui/settings.goml
index 419cc5ebac3..a8417288578 100644
--- a/tests/rustdoc-gui/settings.goml
+++ b/tests/rustdoc-gui/settings.goml
@@ -43,12 +43,12 @@ wait-for: "#settings"
 // We check that the "Use system theme" is disabled.
 assert-property: ("#theme-system-preference", {"checked": "false"})
 // Meaning that only the "theme" menu is showing up.
-assert: ".setting-line:not(.hidden) #theme"
-assert: ".setting-line.hidden #preferred-dark-theme"
-assert: ".setting-line.hidden #preferred-light-theme"
+assert: "#theme.setting-line:not(.hidden)"
+assert: "#preferred-dark-theme.setting-line.hidden"
+assert: "#preferred-light-theme.setting-line.hidden"
 
 // We check that the correct theme is selected.
-assert-property: ("#theme .choices #theme-dark", {"checked": "true"})
+assert-property: ("#theme .setting-radio-choices #theme-dark", {"checked": "true"})
 
 // Some style checks...
 move-cursor-to: "#settings-menu > a"
@@ -109,31 +109,31 @@ assert-css: (
         "box-shadow": "rgb(33, 150, 243) 0px 0px 1px 1px",
     },
 )
-// Now we check the setting-name for radio buttons is on a different line than the label.
+// Now we check the setting-radio-name is on a different line than the label.
 compare-elements-position-near: (
-    "#theme .setting-name",
-    "#theme .choices",
+    "#theme .setting-radio-name",
+    "#theme .setting-radio-choices",
     {"x": 1}
 )
 compare-elements-position-near-false: (
-    "#theme .setting-name",
-    "#theme .choices",
+    "#theme .setting-radio-name",
+    "#theme .setting-radio-choices",
     {"y": 1}
 )
 // Now we check that the label positions are all on the same line.
 compare-elements-position-near: (
-    "#theme .choices #theme-light",
-    "#theme .choices #theme-dark",
+    "#theme .setting-radio-choices #theme-light",
+    "#theme .setting-radio-choices #theme-dark",
     {"y": 1}
 )
 compare-elements-position-near: (
-    "#theme .choices #theme-dark",
-    "#theme .choices #theme-ayu",
+    "#theme .setting-radio-choices #theme-dark",
+    "#theme .setting-radio-choices #theme-ayu",
     {"y": 1}
 )
 compare-elements-position-near: (
-    "#theme .choices #theme-ayu",
-    "#theme .choices #theme-system-preference",
+    "#theme .setting-radio-choices #theme-ayu",
+    "#theme .setting-radio-choices #theme-system-preference",
     {"y": 1}
 )
 
@@ -180,17 +180,17 @@ assert-css: (
 // We now switch the display.
 click: "#theme-system-preference"
 // Wait for the hidden element to show up.
-wait-for: ".setting-line:not(.hidden) #preferred-dark-theme"
-assert: ".setting-line:not(.hidden) #preferred-light-theme"
+wait-for: "#preferred-dark-theme.setting-line:not(.hidden)"
+assert: "#preferred-light-theme.setting-line:not(.hidden)"
 
 // We check their text as well.
-assert-text: ("#preferred-dark-theme .setting-name", "Preferred dark theme")
-assert-text: ("#preferred-light-theme .setting-name", "Preferred light theme")
+assert-text: ("#preferred-dark-theme .setting-radio-name", "Preferred dark theme")
+assert-text: ("#preferred-light-theme .setting-radio-name", "Preferred light theme")
 
 // We now check that clicking on the toggles' text is like clicking on the checkbox.
 // To test it, we use the "Disable keyboard shortcuts".
 local-storage: {"rustdoc-disable-shortcuts": "false"}
-click: ".setting-line:last-child .settings-toggle .label"
+click: ".setting-line:last-child .setting-check span"
 assert-local-storage: {"rustdoc-disable-shortcuts": "true"}
 
 // Make sure that "Disable keyboard shortcuts" actually took effect.
@@ -200,7 +200,7 @@ assert-false: "#help-button .popover"
 wait-for-css: ("#settings-menu .popover", {"display": "block"})
 
 // Now turn keyboard shortcuts back on, and see if they work.
-click: ".setting-line:last-child .settings-toggle .label"
+click: ".setting-line:last-child .setting-check span"
 assert-local-storage: {"rustdoc-disable-shortcuts": "false"}
 press-key: "Escape"
 press-key: "?"
diff --git a/tests/rustdoc-gui/src-font-size.goml b/tests/rustdoc-gui/src-font-size.goml
index 9233f37444b..bab66dae70c 100644
--- a/tests/rustdoc-gui/src-font-size.goml
+++ b/tests/rustdoc-gui/src-font-size.goml
@@ -4,13 +4,13 @@
 goto: "file://" + |DOC_PATH| + "/test_docs/struct.Foo.html"
 show-text: true
 // Check the impl headers.
-assert-css: (".impl.has-srclink .srclink", {"font-size": "16px", "font-weight": 400}, ALL)
-assert-css: (".impl.has-srclink .code-header", {"font-size": "18px", "font-weight": 600}, ALL)
+assert-css: (".impl .srclink", {"font-size": "16px", "font-weight": 400}, ALL)
+assert-css: (".impl .code-header", {"font-size": "18px", "font-weight": 600}, ALL)
 // Check the impl items.
-assert-css: (".impl-items .has-srclink .srclink", {"font-size": "16px", "font-weight": 400}, ALL)
-assert-css: (".impl-items .has-srclink .code-header", {"font-size": "16px", "font-weight": 600}, ALL)
+assert-css: (".impl-items .srclink", {"font-size": "16px", "font-weight": 400}, ALL)
+assert-css: (".impl-items .code-header", {"font-size": "16px", "font-weight": 600}, ALL)
 
 // Check that we can click on source link
 store-document-property: (url, "URL")
-click: ".impl-items .has-srclink .srclink"
+click: ".impl-items .srclink"
 assert-document-property-false: {"URL": |url|}
diff --git a/tests/rustdoc-gui/theme-change.goml b/tests/rustdoc-gui/theme-change.goml
index cc47f1f450c..31c9d99aa83 100644
--- a/tests/rustdoc-gui/theme-change.goml
+++ b/tests/rustdoc-gui/theme-change.goml
@@ -43,7 +43,7 @@ assert-local-storage: { "rustdoc-theme": "ayu" }
 
 assert-local-storage-false: { "rustdoc-use-system-theme": "true" }
 click: "#theme-system-preference"
-wait-for: ".setting-line:not(.hidden) #preferred-light-theme"
+wait-for: "#preferred-light-theme.setting-line:not(.hidden)"
 assert-local-storage: { "rustdoc-use-system-theme": "true" }
 // We click on both preferred light and dark themes to be sure that there is a change.
 click: "#preferred-light-theme-dark"
@@ -52,16 +52,16 @@ wait-for-css: ("body", { "background-color": |background_dark| })
 
 reload:
 // Ensure that the "preferred themes" are still displayed.
-wait-for: ".setting-line:not(.hidden) #preferred-light-theme"
+wait-for: "#preferred-light-theme.setting-line:not(.hidden)"
 click: "#theme-light"
 wait-for-css: ("body", { "background-color": |background_light| })
 assert-local-storage: { "rustdoc-theme": "light" }
 // Ensure it's now hidden again
-wait-for: ".setting-line.hidden #preferred-light-theme"
+wait-for: "#preferred-light-theme.setting-line.hidden"
 // And ensure the theme was rightly set.
 wait-for-css: ("body", { "background-color": |background_light| })
 assert-local-storage: { "rustdoc-theme": "light" }
 
 reload:
 wait-for: "#settings"
-assert: ".setting-line.hidden #preferred-light-theme"
+assert: "#preferred-light-theme.setting-line.hidden"
diff --git a/tests/rustdoc-gui/unsafe-fn.goml b/tests/rustdoc-gui/unsafe-fn.goml
index d3a672ddde6..3ecb25c82a4 100644
--- a/tests/rustdoc-gui/unsafe-fn.goml
+++ b/tests/rustdoc-gui/unsafe-fn.goml
@@ -4,8 +4,8 @@ goto: "file://" + |DOC_PATH| + "/test_docs/index.html"
 show-text: true
 
 compare-elements-property: (
-    "//a[@title='test_docs::safe_fn fn']/..",
-    "//a[@title='test_docs::unsafe_fn fn']/..",
+    "//a[@title='fn test_docs::safe_fn']/..",
+    "//a[@title='fn test_docs::unsafe_fn']/..",
     ["clientHeight"]
 )
 
diff --git a/tests/rustdoc-ui/z-help.stdout b/tests/rustdoc-ui/z-help.stdout
index 4bdecdc1b79..4f07fca82d1 100644
--- a/tests/rustdoc-ui/z-help.stdout
+++ b/tests/rustdoc-ui/z-help.stdout
@@ -20,6 +20,7 @@
     -Z                                 dlltool=val -- import library generation tool (windows-gnu only)
     -Z                 dont-buffer-diagnostics=val -- emit diagnostics rather than buffering (breaks NLL error downgrading, sorting) (default: no)
     -Z                           drop-tracking=val -- enables drop tracking in generators (default: no)
+    -Z                       drop-tracking-mir=val -- enables drop tracking on MIR in generators (default: no)
     -Z                        dual-proc-macros=val -- load proc macros for both target and host, but only link to the target (default: no)
     -Z                          dump-dep-graph=val -- dump the dependency graph to $RUST_DEP_GRAPH (default: /tmp/dep_graph.gv) (default: no)
     -Z                  dump-drop-tracking-cfg=val -- dump drop-tracking control-flow graph as a `.dot` file (default: no)
@@ -172,6 +173,7 @@
     -Z                                 threads=val -- use a thread pool with N threads
     -Z                        time-llvm-passes=val -- measure time of each LLVM pass (default: no)
     -Z                             time-passes=val -- measure time of each rustc pass (default: no)
+    -Z                   tiny-const-eval-limit=val -- sets a tiny, non-configurable limit for const eval; useful for compiler tests
     -Z                               tls-model=val -- choose the TLS model to use (`rustc --print tls-models` for details)
     -Z                            trace-macros=val -- for every macro invocation, print its name and arguments (default: no)
     -Z                       track-diagnostics=val -- tracks where in rustc a diagnostic was emitted
diff --git a/tests/rustdoc/anchors.no_const_anchor.html b/tests/rustdoc/anchors.no_const_anchor.html
index 75e67330a3e..a8587829d3e 100644
--- a/tests/rustdoc/anchors.no_const_anchor.html
+++ b/tests/rustdoc/anchors.no_const_anchor.html
@@ -1 +1 @@
-<section id="associatedconstant.YOLO" class="method has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#16">source</a><h4 class="code-header">const <a href="#associatedconstant.YOLO" class="constant">YOLO</a>: <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a></h4></section>
\ No newline at end of file
+<section id="associatedconstant.YOLO" class="method"><a class="srclink rightside" href="../src/foo/anchors.rs.html#16">source</a><h4 class="code-header">const <a href="#associatedconstant.YOLO" class="constant">YOLO</a>: <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a></h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_const_anchor2.html b/tests/rustdoc/anchors.no_const_anchor2.html
index c0025197602..4c5e45fea2d 100644
--- a/tests/rustdoc/anchors.no_const_anchor2.html
+++ b/tests/rustdoc/anchors.no_const_anchor2.html
@@ -1 +1 @@
-<section id="associatedconstant.X" class="associatedconstant has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#42">source</a><h4 class="code-header">pub const <a href="#associatedconstant.X" class="constant">X</a>: <a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a> = 0i32</h4></section>
\ No newline at end of file
+<section id="associatedconstant.X" class="associatedconstant"><a class="srclink rightside" href="../src/foo/anchors.rs.html#42">source</a><h4 class="code-header">pub const <a href="#associatedconstant.X" class="constant">X</a>: <a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a> = 0i32</h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_method_anchor.html b/tests/rustdoc/anchors.no_method_anchor.html
index b9ec8bf4c09..44957a5b71a 100644
--- a/tests/rustdoc/anchors.no_method_anchor.html
+++ b/tests/rustdoc/anchors.no_method_anchor.html
@@ -1 +1 @@
-<section id="method.new" class="method has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#48">source</a><h4 class="code-header">pub fn <a href="#method.new" class="fn">new</a>() -&gt; Self</h4></section>
\ No newline at end of file
+<section id="method.new" class="method"><a class="srclink rightside" href="../src/foo/anchors.rs.html#48">source</a><h4 class="code-header">pub fn <a href="#method.new" class="fn">new</a>() -&gt; Self</h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_trait_method_anchor.html b/tests/rustdoc/anchors.no_trait_method_anchor.html
index 4308ddad412..75c2caf87a8 100644
--- a/tests/rustdoc/anchors.no_trait_method_anchor.html
+++ b/tests/rustdoc/anchors.no_trait_method_anchor.html
@@ -1 +1 @@
-<section id="method.bar" class="method has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#23">source</a><h4 class="code-header">fn <a href="#method.bar" class="fn">bar</a>()</h4></section>
\ No newline at end of file
+<section id="method.bar" class="method"><a class="srclink rightside" href="../src/foo/anchors.rs.html#23">source</a><h4 class="code-header">fn <a href="#method.bar" class="fn">bar</a>()</h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_tymethod_anchor.html b/tests/rustdoc/anchors.no_tymethod_anchor.html
index 91eed8a3742..38575eadfa9 100644
--- a/tests/rustdoc/anchors.no_tymethod_anchor.html
+++ b/tests/rustdoc/anchors.no_tymethod_anchor.html
@@ -1 +1 @@
-<section id="tymethod.foo" class="method has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#20">source</a><h4 class="code-header">fn <a href="#tymethod.foo" class="fn">foo</a>()</h4></section>
\ No newline at end of file
+<section id="tymethod.foo" class="method"><a class="srclink rightside" href="../src/foo/anchors.rs.html#20">source</a><h4 class="code-header">fn <a href="#tymethod.foo" class="fn">foo</a>()</h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_type_anchor.html b/tests/rustdoc/anchors.no_type_anchor.html
index 2c66d5aa315..dd65d98fee6 100644
--- a/tests/rustdoc/anchors.no_type_anchor.html
+++ b/tests/rustdoc/anchors.no_type_anchor.html
@@ -1 +1 @@
-<section id="associatedtype.T" class="method has-srclink"><a class="srclink rightside" href="../src/foo/anchors.rs.html#13">source</a><h4 class="code-header">type <a href="#associatedtype.T" class="associatedtype">T</a></h4></section>
\ No newline at end of file
+<section id="associatedtype.T" class="method"><a class="srclink rightside" href="../src/foo/anchors.rs.html#13">source</a><h4 class="code-header">type <a href="#associatedtype.T" class="associatedtype">T</a></h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/anchors.no_type_anchor2.html b/tests/rustdoc/anchors.no_type_anchor2.html
index 72a1186bf7e..f8b59160f15 100644
--- a/tests/rustdoc/anchors.no_type_anchor2.html
+++ b/tests/rustdoc/anchors.no_type_anchor2.html
@@ -1 +1 @@
-<section id="associatedtype.Y" class="associatedtype has-srclink"><h4 class="code-header">type <a href="#associatedtype.Y" class="associatedtype">Y</a> = <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a></h4></section>
+<section id="associatedtype.Y" class="associatedtype"><h4 class="code-header">type <a href="#associatedtype.Y" class="associatedtype">Y</a> = <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a></h4></section>
\ No newline at end of file
diff --git a/tests/rustdoc/async-fn.rs b/tests/rustdoc/async-fn.rs
index fb7ebb5f822..8cafb5a2497 100644
--- a/tests/rustdoc/async-fn.rs
+++ b/tests/rustdoc/async-fn.rs
@@ -77,12 +77,12 @@ struct AsyncFdReadyGuard<'a, T> { x: &'a T }
 
 impl Foo {
     // @has async_fn/struct.Foo.html
-    // @has - '//*[@class="method has-srclink"]' 'pub async fn complicated_lifetimes( &self, context: &impl Bar) -> impl Iterator<Item = &usize>'
+    // @has - '//*[@class="method"]' 'pub async fn complicated_lifetimes( &self, context: &impl Bar) -> impl Iterator<Item = &usize>'
     pub async fn complicated_lifetimes(&self, context: &impl Bar) -> impl Iterator<Item = &usize> {}
     // taken from `tokio` as an example of a method that was particularly bad before
-    // @has - '//*[@class="method has-srclink"]' "pub async fn readable<T>(&self) -> Result<AsyncFdReadyGuard<'_, T>, ()>"
+    // @has - '//*[@class="method"]' "pub async fn readable<T>(&self) -> Result<AsyncFdReadyGuard<'_, T>, ()>"
     pub async fn readable<T>(&self) -> Result<AsyncFdReadyGuard<'_, T>, ()> {}
-    // @has - '//*[@class="method has-srclink"]' "pub async fn mut_self(&mut self)"
+    // @has - '//*[@class="method"]' "pub async fn mut_self(&mut self)"
     pub async fn mut_self(&mut self) {}
 }
 
diff --git a/tests/rustdoc/cfg_doc_reexport.rs b/tests/rustdoc/cfg_doc_reexport.rs
index addb6709db1..89c7f0a6f34 100644
--- a/tests/rustdoc/cfg_doc_reexport.rs
+++ b/tests/rustdoc/cfg_doc_reexport.rs
@@ -5,8 +5,8 @@
 #![no_core]
 
 // @has 'foo/index.html'
-// @has - '//*[@class="item-left module-item"]/*[@class="stab portability"]' 'foobar'
-// @has - '//*[@class="item-left module-item"]/*[@class="stab portability"]' 'bar'
+// @has - '//*[@class="item-left"]/*[@class="stab portability"]' 'foobar'
+// @has - '//*[@class="item-left"]/*[@class="stab portability"]' 'bar'
 
 #[doc(cfg(feature = "foobar"))]
 mod imp_priv {
diff --git a/tests/rustdoc/const-fn.rs b/tests/rustdoc/const-fn.rs
index 4366ad4d0ad..18863abaeac 100644
--- a/tests/rustdoc/const-fn.rs
+++ b/tests/rustdoc/const-fn.rs
@@ -8,7 +8,7 @@ pub const fn bar() -> usize {
 }
 
 // @has foo/struct.Foo.html
-// @has - '//*[@class="method has-srclink"]' 'const fn new()'
+// @has - '//*[@class="method"]' 'const fn new()'
 pub struct Foo(usize);
 
 impl Foo {
diff --git a/tests/rustdoc/const-generics/const-generic-slice.rs b/tests/rustdoc/const-generics/const-generic-slice.rs
index 4279de91f56..80a9ab3f12e 100644
--- a/tests/rustdoc/const-generics/const-generic-slice.rs
+++ b/tests/rustdoc/const-generics/const-generic-slice.rs
@@ -5,7 +5,7 @@ pub trait Array {
 }
 
 // @has foo/trait.Array.html
-// @has - '//*[@class="impl has-srclink"]' 'impl<T, const N: usize> Array for [T; N]'
+// @has - '//*[@class="impl"]' 'impl<T, const N: usize> Array for [T; N]'
 impl<T, const N: usize> Array for [T; N] {
     type Item = T;
 }
diff --git a/tests/rustdoc/deprecated.rs b/tests/rustdoc/deprecated.rs
index b3178da98ee..5cbe4d59108 100644
--- a/tests/rustdoc/deprecated.rs
+++ b/tests/rustdoc/deprecated.rs
@@ -1,4 +1,4 @@
-// @has deprecated/index.html '//*[@class="item-left module-item"]/span[@class="stab deprecated"]' \
+// @has deprecated/index.html '//*[@class="item-left"]/span[@class="stab deprecated"]' \
 //      'Deprecated'
 // @has - '//*[@class="item-right docblock-short"]' 'Deprecated docs'
 
diff --git a/tests/rustdoc/doc-assoc-item.rs b/tests/rustdoc/doc-assoc-item.rs
index 4f15418650c..4d5c9f83e1e 100644
--- a/tests/rustdoc/doc-assoc-item.rs
+++ b/tests/rustdoc/doc-assoc-item.rs
@@ -8,7 +8,7 @@ pub trait Bar {
     fn foo(foo: Self::Fuu);
 }
 
-// @has doc_assoc_item/struct.Foo.html '//*[@class="impl has-srclink"]' 'impl<T: Bar<Fuu = u32>> Foo<T>'
+// @has doc_assoc_item/struct.Foo.html '//*[@class="impl"]' 'impl<T: Bar<Fuu = u32>> Foo<T>'
 impl<T: Bar<Fuu = u32>> Foo<T> {
     pub fn new(t: T) -> Foo<T> {
         Foo {
diff --git a/tests/rustdoc/doc-cfg.rs b/tests/rustdoc/doc-cfg.rs
index 4cddb0b76d4..1cfbfec6fcd 100644
--- a/tests/rustdoc/doc-cfg.rs
+++ b/tests/rustdoc/doc-cfg.rs
@@ -12,7 +12,7 @@ pub struct Portable;
 // @has doc_cfg/unix_only/index.html \
 //  '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
 //  'Available on Unix only.'
-// @matches - '//*[@class="item-left module-item"]//*[@class="stab portability"]' '\AARM\Z'
+// @matches - '//*[@class="item-left"]//*[@class="stab portability"]' '\AARM\Z'
 // @count - '//*[@class="stab portability"]' 2
 #[doc(cfg(unix))]
 pub mod unix_only {
@@ -42,7 +42,7 @@ pub mod unix_only {
 // @has doc_cfg/wasi_only/index.html \
 //  '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
 //  'Available on WASI only.'
-// @matches - '//*[@class="item-left module-item"]//*[@class="stab portability"]' '\AWebAssembly\Z'
+// @matches - '//*[@class="item-left"]//*[@class="stab portability"]' '\AWebAssembly\Z'
 // @count - '//*[@class="stab portability"]' 2
 #[doc(cfg(target_os = "wasi"))]
 pub mod wasi_only {
@@ -74,7 +74,7 @@ pub mod wasi_only {
 
 // the portability header is different on the module view versus the full view
 // @has doc_cfg/index.html
-// @matches - '//*[@class="item-left module-item"]//*[@class="stab portability"]' '\Aavx\Z'
+// @matches - '//*[@class="item-left"]//*[@class="stab portability"]' '\Aavx\Z'
 
 // @has doc_cfg/fn.uses_target_feature.html
 // @has - '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
diff --git a/tests/rustdoc/duplicate-cfg.rs b/tests/rustdoc/duplicate-cfg.rs
index 18f3900b263..1ac2e523249 100644
--- a/tests/rustdoc/duplicate-cfg.rs
+++ b/tests/rustdoc/duplicate-cfg.rs
@@ -2,8 +2,8 @@
 #![feature(doc_cfg)]
 
 // @has 'foo/index.html'
-// @matches '-' '//*[@class="item-left module-item"]//*[@class="stab portability"]' '^sync$'
-// @has '-' '//*[@class="item-left module-item"]//*[@class="stab portability"]/@title' 'Available on crate feature `sync` only'
+// @matches '-' '//*[@class="item-left"]//*[@class="stab portability"]' '^sync$'
+// @has '-' '//*[@class="item-left"]//*[@class="stab portability"]/@title' 'Available on crate feature `sync` only'
 
 // @has 'foo/struct.Foo.html'
 // @has '-' '//*[@class="stab portability"]' 'sync'
diff --git a/tests/rustdoc/duplicate_impls/issue-33054.rs b/tests/rustdoc/duplicate_impls/issue-33054.rs
index c1f95ac91c3..4c2071b8322 100644
--- a/tests/rustdoc/duplicate_impls/issue-33054.rs
+++ b/tests/rustdoc/duplicate_impls/issue-33054.rs
@@ -3,8 +3,8 @@
 // @has issue_33054/impls/struct.Foo.html
 // @has - '//h3[@class="code-header"]' 'impl Foo'
 // @has - '//h3[@class="code-header"]' 'impl Bar for Foo'
-// @count - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]' 1
-// @count - '//*[@id="main-content"]/div[@id="implementations-list"]/details/summary/*[@class="impl has-srclink"]' 1
+// @count - '//*[@id="trait-implementations-list"]//*[@class="impl"]' 1
+// @count - '//*[@id="main-content"]/div[@id="implementations-list"]/details/summary/*[@class="impl"]' 1
 // @has issue_33054/impls/bar/trait.Bar.html
 // @has - '//h3[@class="code-header"]' 'impl Bar for Foo'
 // @count - '//*[@class="struct"]' 1
diff --git a/tests/rustdoc/duplicated_impl.rs b/tests/rustdoc/duplicated_impl.rs
index 4e901b31c90..f32cf310055 100644
--- a/tests/rustdoc/duplicated_impl.rs
+++ b/tests/rustdoc/duplicated_impl.rs
@@ -7,7 +7,7 @@
 // blanket implementations.
 
 // @has 'foo/struct.Whatever.html'
-// @count - '//*[@id="blanket-implementations-list"]/section[@class="impl has-srclink"]' 1
+// @count - '//*[@id="blanket-implementations-list"]/section[@class="impl"]' 1
 
 pub trait Something<T> { }
 pub struct Whatever;
diff --git a/tests/rustdoc/empty-impl-block-private-with-doc.rs b/tests/rustdoc/empty-impl-block-private-with-doc.rs
index 43971996163..e6cff97b184 100644
--- a/tests/rustdoc/empty-impl-block-private-with-doc.rs
+++ b/tests/rustdoc/empty-impl-block-private-with-doc.rs
@@ -10,7 +10,7 @@ pub struct Foo;
 // There are 3 impl blocks with public item and one that should not be displayed
 // by default because it only contains private items (but not in this case because
 // we used `--document-private-items`).
-// @count - '//*[@class="impl has-srclink"]' 'impl Foo' 4
+// @count - '//*[@class="impl"]' 'impl Foo' 4
 
 // Impl block only containing private items should not be displayed unless the
 // `--document-private-items` flag is used.
diff --git a/tests/rustdoc/empty-impl-block-private.rs b/tests/rustdoc/empty-impl-block-private.rs
index 5caf020658c..d44b4a47cee 100644
--- a/tests/rustdoc/empty-impl-block-private.rs
+++ b/tests/rustdoc/empty-impl-block-private.rs
@@ -7,7 +7,7 @@ pub struct Foo;
 
 // There are 3 impl blocks with public item and one that should not be displayed
 // because it only contains private items.
-// @count - '//*[@class="impl has-srclink"]' 'impl Foo' 3
+// @count - '//*[@class="impl"]' 'impl Foo' 3
 
 // Impl block only containing private items should not be displayed.
 /// Private
diff --git a/tests/rustdoc/empty-impl-block.rs b/tests/rustdoc/empty-impl-block.rs
index 95d4db06b31..da780580bd0 100644
--- a/tests/rustdoc/empty-impl-block.rs
+++ b/tests/rustdoc/empty-impl-block.rs
@@ -8,7 +8,7 @@ pub struct Foo;
 /// Hello empty impl block!
 impl Foo {}
 // We ensure that this empty impl block without doc isn't rendered.
-// @count - '//*[@class="impl has-srclink"]' 'impl Foo' 1
+// @count - '//*[@class="impl"]' 'impl Foo' 1
 impl Foo {}
 
 // Just to ensure that empty trait impl blocks are rendered.
diff --git a/tests/rustdoc/glob-shadowing.rs b/tests/rustdoc/glob-shadowing.rs
index 66a31c42bcf..2668b333497 100644
--- a/tests/rustdoc/glob-shadowing.rs
+++ b/tests/rustdoc/glob-shadowing.rs
@@ -1,5 +1,5 @@
 // @has 'glob_shadowing/index.html'
-// @count - '//div[@class="item-left module-item"]' 6
+// @count - '//div[@class="item-left"]' 6
 // @!has - '//div[@class="item-right docblock-short"]' 'sub1::describe'
 // @has - '//div[@class="item-right docblock-short"]' 'sub2::describe'
 
diff --git a/tests/rustdoc/impl-parts.rs b/tests/rustdoc/impl-parts.rs
index 90cbb77cb6b..f7738060e99 100644
--- a/tests/rustdoc/impl-parts.rs
+++ b/tests/rustdoc/impl-parts.rs
@@ -5,7 +5,7 @@ pub auto trait AnAutoTrait {}
 
 pub struct Foo<T> { field: T }
 
-// @has impl_parts/struct.Foo.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has impl_parts/struct.Foo.html '//*[@class="impl"]//h3[@class="code-header"]' \
 //     "impl<T> !AnAutoTrait for Foo<T>where T: Sync + Clone,"
 // @has impl_parts/trait.AnAutoTrait.html '//*[@id="implementors-list"]//h3[@class="code-header"]' \
 //     "impl<T> !AnAutoTrait for Foo<T>where T: Sync + Clone,"
diff --git a/tests/rustdoc/inline_cross/issue-31948-1.rs b/tests/rustdoc/inline_cross/issue-31948-1.rs
index 6e89167b3a4..571eaf6be96 100644
--- a/tests/rustdoc/inline_cross/issue-31948-1.rs
+++ b/tests/rustdoc/inline_cross/issue-31948-1.rs
@@ -5,8 +5,8 @@
 extern crate rustdoc_nonreachable_impls;
 
 // @has issue_31948_1/struct.Wobble.html
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Bark for'
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Woof for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bark for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Woof for'
 // @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bar for'
 // @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'Qux for'
 pub use rustdoc_nonreachable_impls::hidden::Wobble;
diff --git a/tests/rustdoc/inline_cross/issue-31948-2.rs b/tests/rustdoc/inline_cross/issue-31948-2.rs
index 141e07656a0..7eae21046cc 100644
--- a/tests/rustdoc/inline_cross/issue-31948-2.rs
+++ b/tests/rustdoc/inline_cross/issue-31948-2.rs
@@ -5,9 +5,9 @@
 extern crate rustdoc_nonreachable_impls;
 
 // @has issue_31948_2/struct.Wobble.html
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Qux for'
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Bark for'
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Woof for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Qux for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bark for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Woof for'
 // @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bar for'
 pub use rustdoc_nonreachable_impls::hidden::Wobble;
 
diff --git a/tests/rustdoc/inline_cross/issue-31948.rs b/tests/rustdoc/inline_cross/issue-31948.rs
index 96fc6ca47e7..9c271bf4ad4 100644
--- a/tests/rustdoc/inline_cross/issue-31948.rs
+++ b/tests/rustdoc/inline_cross/issue-31948.rs
@@ -5,9 +5,9 @@
 extern crate rustdoc_nonreachable_impls;
 
 // @has issue_31948/struct.Foo.html
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Bark for'
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Woof for'
-// @!has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'Bar for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bark for'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'Woof for'
+// @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'Bar for'
 // @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'Qux for'
 pub use rustdoc_nonreachable_impls::Foo;
 
diff --git a/tests/rustdoc/inline_cross/macros.rs b/tests/rustdoc/inline_cross/macros.rs
index 5daa0d4baad..d5b0de5725b 100644
--- a/tests/rustdoc/inline_cross/macros.rs
+++ b/tests/rustdoc/inline_cross/macros.rs
@@ -6,9 +6,9 @@
 
 extern crate macros;
 
-// @has foo/index.html '//*[@class="item-left unstable deprecated module-item"]/span[@class="stab deprecated"]' \
+// @has foo/index.html '//*[@class="item-left unstable deprecated"]/span[@class="stab deprecated"]' \
 //         Deprecated
-// @has - '//*[@class="item-left unstable deprecated module-item"]/span[@class="stab unstable"]' \
+// @has - '//*[@class="item-left unstable deprecated"]/span[@class="stab unstable"]' \
 //         Experimental
 
 // @has foo/macro.my_macro.html
diff --git a/tests/rustdoc/issue-107350.rs b/tests/rustdoc/issue-107350.rs
new file mode 100644
index 00000000000..75f378ed249
--- /dev/null
+++ b/tests/rustdoc/issue-107350.rs
@@ -0,0 +1,18 @@
+// This is a regression test for <https://github.com/rust-lang/rust/issues/107350>.
+// It shouldn't loop indefinitely.
+
+#![crate_name = "foo"]
+
+// @has 'foo/oops/enum.OhNo.html'
+
+pub mod oops {
+    pub use crate::oops::OhNo;
+
+    mod inner {
+        pub enum OhNo {
+            Item = 1,
+        }
+    }
+
+    pub use self::inner::*;
+}
diff --git a/tests/rustdoc/issue-21474.rs b/tests/rustdoc/issue-21474.rs
index 43ce13fd9b1..5de26abace6 100644
--- a/tests/rustdoc/issue-21474.rs
+++ b/tests/rustdoc/issue-21474.rs
@@ -7,5 +7,5 @@ mod inner {
 pub trait Blah { }
 
 // @count issue_21474/struct.What.html \
-//        '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]' 1
+//        '//*[@id="trait-implementations-list"]//*[@class="impl"]' 1
 pub struct What;
diff --git a/tests/rustdoc/issue-32374.rs b/tests/rustdoc/issue-32374.rs
index 8d2c27cf3d7..8296d7a81f2 100644
--- a/tests/rustdoc/issue-32374.rs
+++ b/tests/rustdoc/issue-32374.rs
@@ -2,9 +2,9 @@
 #![doc(issue_tracker_base_url = "https://issue_url/")]
 #![unstable(feature = "test", issue = "32374")]
 
-// @matches issue_32374/index.html '//*[@class="item-left unstable deprecated module-item"]/span[@class="stab deprecated"]' \
+// @matches issue_32374/index.html '//*[@class="item-left unstable deprecated"]/span[@class="stab deprecated"]' \
 //      'Deprecated'
-// @matches issue_32374/index.html '//*[@class="item-left unstable deprecated module-item"]/span[@class="stab unstable"]' \
+// @matches issue_32374/index.html '//*[@class="item-left unstable deprecated"]/span[@class="stab unstable"]' \
 //      'Experimental'
 // @matches issue_32374/index.html '//*[@class="item-right docblock-short"]/text()' 'Docs'
 
diff --git a/tests/rustdoc/issue-33302.rs b/tests/rustdoc/issue-33302.rs
index b4c52e2f17a..7af00c77836 100644
--- a/tests/rustdoc/issue-33302.rs
+++ b/tests/rustdoc/issue-33302.rs
@@ -22,7 +22,7 @@ macro_rules! make {
         }
 
         // @has issue_33302/struct.S.html \
-        //        '//*[@class="impl has-srclink"]' 'impl T<[i32; 16]> for S'
+        //        '//*[@class="impl"]' 'impl T<[i32; 16]> for S'
         // @has - '//*[@id="associatedconstant.C"]' 'const C: [i32; 16]'
         // @has - '//*[@id="associatedconstant.D"]' 'const D: i32'
         impl T<[i32; ($n * $n)]> for S {
@@ -30,7 +30,7 @@ macro_rules! make {
         }
 
         // @has issue_33302/struct.S.html \
-        //        '//*[@class="impl has-srclink"]' 'impl T<[i32; 16]> for S'
+        //        '//*[@class="impl"]' 'impl T<[i32; 16]> for S'
         // @has - '//*[@id="associatedconstant.C-1"]' 'const C: (i32,)'
         // @has - '//*[@id="associatedconstant.D-1"]' 'const D: i32'
         impl T<(i32,)> for S {
@@ -38,7 +38,7 @@ macro_rules! make {
         }
 
         // @has issue_33302/struct.S.html \
-        //        '//*[@class="impl has-srclink"]' 'impl T<(i32, i32)> for S'
+        //        '//*[@class="impl"]' 'impl T<(i32, i32)> for S'
         // @has - '//*[@id="associatedconstant.C-2"]' 'const C: (i32, i32)'
         // @has - '//*[@id="associatedconstant.D-2"]' 'const D: i32'
         impl T<(i32, i32)> for S {
diff --git a/tests/rustdoc/issue-45584.rs b/tests/rustdoc/issue-45584.rs
index 86479e6fb2e..8a5f0413826 100644
--- a/tests/rustdoc/issue-45584.rs
+++ b/tests/rustdoc/issue-45584.rs
@@ -4,12 +4,12 @@ pub trait Bar<T, U> {}
 
 // @has 'foo/struct.Foo1.html'
 pub struct Foo1;
-// @count - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]' 1
-// @has - '//*[@class="impl has-srclink"]' "impl Bar<Foo1, &'static Foo1> for Foo1"
+// @count - '//*[@id="trait-implementations-list"]//*[@class="impl"]' 1
+// @has - '//*[@class="impl"]' "impl Bar<Foo1, &'static Foo1> for Foo1"
 impl Bar<Foo1, &'static Foo1> for Foo1 {}
 
 // @has 'foo/struct.Foo2.html'
 pub struct Foo2;
-// @count - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]' 1
-// @has - '//*[@class="impl has-srclink"]' "impl Bar<&'static Foo2, Foo2> for u8"
+// @count - '//*[@id="trait-implementations-list"]//*[@class="impl"]' 1
+// @has - '//*[@class="impl"]' "impl Bar<&'static Foo2, Foo2> for u8"
 impl Bar<&'static Foo2, Foo2> for u8 {}
diff --git a/tests/rustdoc/issue-50159.rs b/tests/rustdoc/issue-50159.rs
index 04bc4f304d6..13bedd5dbb0 100644
--- a/tests/rustdoc/issue-50159.rs
+++ b/tests/rustdoc/issue-50159.rs
@@ -14,7 +14,7 @@ impl<B, C> Signal2 for B where B: Signal<Item = C> {
 // @has - '//h3[@class="code-header"]' 'impl<B> Send for Switch<B>where <B as Signal>::Item: Send'
 // @has - '//h3[@class="code-header"]' 'impl<B> Sync for Switch<B>where <B as Signal>::Item: Sync'
 // @count - '//*[@id="implementations-list"]//*[@class="impl"]' 0
-// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]' 5
+// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]' 5
 pub struct Switch<B: Signal> {
     pub inner: <B as Signal2>::Item2,
 }
diff --git a/tests/rustdoc/issue-51236.rs b/tests/rustdoc/issue-51236.rs
index 1c7aa9c7eef..04664805a88 100644
--- a/tests/rustdoc/issue-51236.rs
+++ b/tests/rustdoc/issue-51236.rs
@@ -7,7 +7,7 @@ pub mod traits {
 }
 
 // @has issue_51236/struct.Owned.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> Send for Owned<T>where <T as Owned<'static>>::Reader: Send"
 pub struct Owned<T> where T: for<'a> ::traits::Owned<'a> {
     marker: PhantomData<<T as ::traits::Owned<'static>>::Reader>,
diff --git a/tests/rustdoc/issue-53812.rs b/tests/rustdoc/issue-53812.rs
index c68ffd52186..dc1eb304c3d 100644
--- a/tests/rustdoc/issue-53812.rs
+++ b/tests/rustdoc/issue-53812.rs
@@ -12,9 +12,9 @@ macro_rules! array_impls {
 }
 
 // @has issue_53812/trait.MyIterator.html
-// @has - '//*[@id="implementors-list"]/*[@class="impl has-srclink"][1]' 'MyStruct<[T; 0]>'
-// @has - '//*[@id="implementors-list"]/*[@class="impl has-srclink"][2]' 'MyStruct<[T; 1]>'
-// @has - '//*[@id="implementors-list"]/*[@class="impl has-srclink"][3]' 'MyStruct<[T; 2]>'
-// @has - '//*[@id="implementors-list"]/*[@class="impl has-srclink"][4]' 'MyStruct<[T; 3]>'
-// @has - '//*[@id="implementors-list"]/*[@class="impl has-srclink"][5]' 'MyStruct<[T; 10]>'
+// @has - '//*[@id="implementors-list"]/*[@class="impl"][1]' 'MyStruct<[T; 0]>'
+// @has - '//*[@id="implementors-list"]/*[@class="impl"][2]' 'MyStruct<[T; 1]>'
+// @has - '//*[@id="implementors-list"]/*[@class="impl"][3]' 'MyStruct<[T; 2]>'
+// @has - '//*[@id="implementors-list"]/*[@class="impl"][4]' 'MyStruct<[T; 3]>'
+// @has - '//*[@id="implementors-list"]/*[@class="impl"][5]' 'MyStruct<[T; 10]>'
 array_impls! { 10 3 2 1 0 }
diff --git a/tests/rustdoc/issue-54705.rs b/tests/rustdoc/issue-54705.rs
index 7b7290ab4b7..a886eb0de24 100644
--- a/tests/rustdoc/issue-54705.rs
+++ b/tests/rustdoc/issue-54705.rs
@@ -1,10 +1,10 @@
 pub trait ScopeHandle<'scope> {}
 
 // @has issue_54705/struct.ScopeFutureContents.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'scope, S> Send for ScopeFutureContents<'scope, S>where S: Sync"
 //
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'scope, S> Sync for ScopeFutureContents<'scope, S>where S: Sync"
 pub struct ScopeFutureContents<'scope, S>
     where S: ScopeHandle<'scope>,
diff --git a/tests/rustdoc/issue-55321.rs b/tests/rustdoc/issue-55321.rs
index 22a18ef90e1..d3c2070d915 100644
--- a/tests/rustdoc/issue-55321.rs
+++ b/tests/rustdoc/issue-55321.rs
@@ -1,9 +1,9 @@
 #![feature(negative_impls)]
 
 // @has issue_55321/struct.A.html
-// @has - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="trait-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl !Send for A"
-// @has - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="trait-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl !Sync for A"
 pub struct A();
 
@@ -11,8 +11,8 @@ impl !Send for A {}
 impl !Sync for A {}
 
 // @has issue_55321/struct.B.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Send for B<T>"
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Sync for B<T>"
 pub struct B<T: ?Sized>(A, Box<T>);
diff --git a/tests/rustdoc/issue-55364.rs b/tests/rustdoc/issue-55364.rs
index 14a6f5041f2..b987da30ed2 100644
--- a/tests/rustdoc/issue-55364.rs
+++ b/tests/rustdoc/issue-55364.rs
@@ -29,8 +29,8 @@ pub mod subone {
 // @has - '//section[@id="main-content"]/details/div[@class="docblock"]//a[@href="../fn.foo.html"]' 'foo'
 // @has - '//section[@id="main-content"]/details/div[@class="docblock"]//a[@href="../fn.bar.html"]' 'bar'
 // Though there should be such links later
-// @has - '//section[@id="main-content"]/div[@class="item-table"]//div[@class="item-left module-item"]/a[@class="fn"][@href="fn.foo.html"]' 'foo'
-// @has - '//section[@id="main-content"]/div[@class="item-table"]//div[@class="item-left module-item"]/a[@class="fn"][@href="fn.bar.html"]' 'bar'
+// @has - '//section[@id="main-content"]/div[@class="item-table"]//div[@class="item-left"]/a[@class="fn"][@href="fn.foo.html"]' 'foo'
+// @has - '//section[@id="main-content"]/div[@class="item-table"]//div[@class="item-left"]/a[@class="fn"][@href="fn.bar.html"]' 'bar'
 /// See either [foo] or [bar].
 pub mod subtwo {
 
diff --git a/tests/rustdoc/issue-56822.rs b/tests/rustdoc/issue-56822.rs
index b4eef344b5f..c9a74335702 100644
--- a/tests/rustdoc/issue-56822.rs
+++ b/tests/rustdoc/issue-56822.rs
@@ -17,7 +17,7 @@ impl<'a, T> MyTrait for Inner<'a, T> {
 }
 
 // @has issue_56822/struct.Parser.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'a> Send for Parser<'a>"
 pub struct Parser<'a> {
     field: <Wrapper<Inner<'a, u8>> as MyTrait>::Output
diff --git a/tests/rustdoc/issue-60726.rs b/tests/rustdoc/issue-60726.rs
index fbb0f82ae39..e337e4a4f7a 100644
--- a/tests/rustdoc/issue-60726.rs
+++ b/tests/rustdoc/issue-60726.rs
@@ -26,9 +26,9 @@ where
 {}
 
 // @has issue_60726/struct.IntoIter.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Send for IntoIter<T>"
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Sync for IntoIter<T>"
 pub struct IntoIter<T>{
     hello:DynTrait<FooInterface<T>>,
diff --git a/tests/rustdoc/issue-76501.rs b/tests/rustdoc/issue-76501.rs
index a90e0fea092..5caea0ec992 100644
--- a/tests/rustdoc/issue-76501.rs
+++ b/tests/rustdoc/issue-76501.rs
@@ -8,7 +8,7 @@ pub const fn bloop() -> i32 {
 pub struct Struct {}
 
 impl Struct {
-    // @has 'issue_76501/struct.Struct.html' '//*[@class="method has-srclink"]' \
+    // @has 'issue_76501/struct.Struct.html' '//*[@class="method"]' \
     // 'pub const fn blurp() -> i32'
     /// A useless function that always returns 1.
     pub const fn blurp() -> i32 {
diff --git a/tests/rustdoc/issue-78673.rs b/tests/rustdoc/issue-78673.rs
index 2e4bec2544c..d09141c3204 100644
--- a/tests/rustdoc/issue-78673.rs
+++ b/tests/rustdoc/issue-78673.rs
@@ -7,8 +7,8 @@ pub trait AnAmazingTrait {}
 impl<T: Something> AnAmazingTrait for T {}
 
 // @has 'issue_78673/struct.MyStruct.html'
-// @has  - '//*[@class="impl has-srclink"]' 'AnAmazingTrait for MyStruct'
-// @!has - '//*[@class="impl has-srclink"]' 'AnAmazingTrait for T'
+// @has  - '//*[@class="impl"]' 'AnAmazingTrait for MyStruct'
+// @!has - '//*[@class="impl"]' 'AnAmazingTrait for T'
 pub struct MyStruct;
 
 impl AnAmazingTrait for MyStruct {}
@@ -16,8 +16,8 @@ impl AnAmazingTrait for MyStruct {}
 // generic structs may have _both_ specific and blanket impls that apply
 
 // @has 'issue_78673/struct.AnotherStruct.html'
-// @has - '//*[@class="impl has-srclink"]' 'AnAmazingTrait for AnotherStruct<()>'
-// @has - '//*[@class="impl has-srclink"]' 'AnAmazingTrait for T'
+// @has - '//*[@class="impl"]' 'AnAmazingTrait for AnotherStruct<()>'
+// @has - '//*[@class="impl"]' 'AnAmazingTrait for T'
 pub struct AnotherStruct<T>(T);
 
 impl<T: Something> Something for AnotherStruct<T> {}
diff --git a/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline-last-item.rs b/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline-last-item.rs
index d3a7a870b58..9bce25846d8 100644
--- a/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline-last-item.rs
+++ b/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline-last-item.rs
@@ -11,6 +11,6 @@ pub mod sub {
 #[doc(inline)]
 pub use sub::*;
 
-// @count foo/index.html '//a[@class="mod"][@title="foo::prelude mod"]' 1
+// @count foo/index.html '//a[@class="mod"][@title="mod foo::prelude"]' 1
 // @count foo/prelude/index.html '//div[@class="item-row"]' 0
 pub mod prelude {}
diff --git a/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline.rs b/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline.rs
index b8369250993..d0960dfef43 100644
--- a/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline.rs
+++ b/tests/rustdoc/issue-83375-multiple-mods-w-same-name-doc-inline.rs
@@ -8,7 +8,7 @@ pub mod sub {
     }
 }
 
-// @count foo/index.html '//a[@class="mod"][@title="foo::prelude mod"]' 1
+// @count foo/index.html '//a[@class="mod"][@title="mod foo::prelude"]' 1
 // @count foo/prelude/index.html '//div[@class="item-row"]' 0
 pub mod prelude {}
 
diff --git a/tests/rustdoc/issue-95873.rs b/tests/rustdoc/issue-95873.rs
index ff33fb63a0b..3df93eb7cf1 100644
--- a/tests/rustdoc/issue-95873.rs
+++ b/tests/rustdoc/issue-95873.rs
@@ -1,2 +1,2 @@
-// @has issue_95873/index.html "//*[@class='item-left import-item']" "pub use ::std as x;"
+// @has issue_95873/index.html "//*[@class='item-left']" "pub use ::std as x;"
 pub use ::std as x;
diff --git a/tests/rustdoc/issue-99221-multiple-structs-w-same-name.rs b/tests/rustdoc/issue-99221-multiple-structs-w-same-name.rs
index 41e64726a32..ba29a77ebdf 100644
--- a/tests/rustdoc/issue-99221-multiple-structs-w-same-name.rs
+++ b/tests/rustdoc/issue-99221-multiple-structs-w-same-name.rs
@@ -9,6 +9,6 @@ extern crate issue_99221_aux;
 
 pub use issue_99221_aux::*;
 
-// @count foo/index.html '//a[@class="struct"][@title="foo::Print struct"]' 1
+// @count foo/index.html '//a[@class="struct"][@title="struct foo::Print"]' 1
 
 pub struct Print;
diff --git a/tests/rustdoc/issue-99734-multiple-foreigns-w-same-name.rs b/tests/rustdoc/issue-99734-multiple-foreigns-w-same-name.rs
index 3208fea05b3..b56ec6e11ea 100644
--- a/tests/rustdoc/issue-99734-multiple-foreigns-w-same-name.rs
+++ b/tests/rustdoc/issue-99734-multiple-foreigns-w-same-name.rs
@@ -9,7 +9,7 @@ extern crate issue_99734_aux;
 
 pub use issue_99734_aux::*;
 
-// @count foo/index.html '//a[@class="fn"][@title="foo::main fn"]' 1
+// @count foo/index.html '//a[@class="fn"][@title="fn foo::main"]' 1
 
 extern "C" {
     pub fn main() -> std::ffi::c_int;
diff --git a/tests/rustdoc/issue-99734-multiple-mods-w-same-name.rs b/tests/rustdoc/issue-99734-multiple-mods-w-same-name.rs
index b2f9b8b4657..8f5d6fa3d56 100644
--- a/tests/rustdoc/issue-99734-multiple-mods-w-same-name.rs
+++ b/tests/rustdoc/issue-99734-multiple-mods-w-same-name.rs
@@ -9,6 +9,6 @@ extern crate issue_99734_aux;
 
 pub use issue_99734_aux::*;
 
-// @count foo/index.html '//a[@class="mod"][@title="foo::task mod"]' 1
+// @count foo/index.html '//a[@class="mod"][@title="mod foo::task"]' 1
 
 pub mod task {}
diff --git a/tests/rustdoc/mut-params.rs b/tests/rustdoc/mut-params.rs
index 3b862e651c9..431db51d95f 100644
--- a/tests/rustdoc/mut-params.rs
+++ b/tests/rustdoc/mut-params.rs
@@ -5,7 +5,7 @@
 
 pub struct Foo;
 
-// @count foo/struct.Foo.html '//*[@class="impl-items"]//*[@class="method has-srclink"]' 2
+// @count foo/struct.Foo.html '//*[@class="impl-items"]//*[@class="method"]' 2
 // @!has - '//*[@class="impl-items"]//*[@class="method"]' 'mut'
 impl Foo {
     pub fn foo(mut self) {}
diff --git a/tests/rustdoc/negative-impl.rs b/tests/rustdoc/negative-impl.rs
index af19c784d6d..51223af6737 100644
--- a/tests/rustdoc/negative-impl.rs
+++ b/tests/rustdoc/negative-impl.rs
@@ -5,10 +5,10 @@ pub struct Alpha;
 // @matches negative_impl/struct.Bravo.html '//pre' "pub struct Bravo<B>"
 pub struct Bravo<B>(B);
 
-// @matches negative_impl/struct.Alpha.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @matches negative_impl/struct.Alpha.html '//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl !Send for Alpha"
 impl !Send for Alpha {}
 
-// @matches negative_impl/struct.Bravo.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' "\
+// @matches negative_impl/struct.Bravo.html '//*[@class="impl"]//h3[@class="code-header"]' "\
 // impl<B> !Send for Bravo<B>"
 impl<B> !Send for Bravo<B> {}
diff --git a/tests/rustdoc/playground-arg.rs b/tests/rustdoc/playground-arg.rs
index 69c89626539..f3811fe0b0a 100644
--- a/tests/rustdoc/playground-arg.rs
+++ b/tests/rustdoc/playground-arg.rs
@@ -10,4 +10,4 @@
 pub fn dummy() {}
 
 // ensure that `extern crate foo;` was inserted into code snips automatically:
-// @matches foo/index.html '//a[@class="test-arrow"][@href="https://example.com/?code=%23!%5Ballow(unused)%5D%0Aextern%20crate%20r%23foo%3B%0Afn%20main()%20%7B%0Ause%20foo%3A%3Adummy%3B%0Adummy()%3B%0A%7D&edition=2015"]' "Run"
+// @matches foo/index.html '//a[@class="test-arrow"][@href="https://example.com/?code=%23!%5Ballow(unused)%5D%0Aextern+crate+r%23foo;%0Afn+main()+%7B%0Ause+foo::dummy;%0Adummy();%0A%7D&edition=2015"]' "Run"
diff --git a/tests/rustdoc/playground.rs b/tests/rustdoc/playground.rs
index 877ea1cfba1..5c7fa33efc5 100644
--- a/tests/rustdoc/playground.rs
+++ b/tests/rustdoc/playground.rs
@@ -22,6 +22,6 @@
 //! }
 //! ```
 
-// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22Hello%2C%20world!%22)%3B%0A%7D&edition=2015"]' "Run"
-// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Aprintln!(%22Hello%2C%20world!%22)%3B%0A%7D&edition=2015"]' "Run"
-// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0A%23!%5Bfeature(something)%5D%0A%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22Hello%2C%20world!%22)%3B%0A%7D&version=nightly&edition=2015"]' "Run"
+// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0Afn+main()+%7B%0Aprintln!(%22Hello,+world!%22);%0A%7D&edition=2015"]' "Run"
+// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0Afn+main()+%7B%0A++++println!(%22Hello,+world!%22);%0A%7D&edition=2015"]' "Run"
+// @matches foo/index.html '//a[@class="test-arrow"][@href="https://www.example.com/?code=%23!%5Ballow(unused)%5D%0A%23!%5Bfeature(something)%5D%0A%0Afn+main()+%7B%0A++++println!(%22Hello,+world!%22);%0A%7D&version=nightly&edition=2015"]' "Run"
diff --git a/tests/rustdoc/primitive-reference.rs b/tests/rustdoc/primitive-reference.rs
index c3a5eb6d324..10efbefd2b1 100644
--- a/tests/rustdoc/primitive-reference.rs
+++ b/tests/rustdoc/primitive-reference.rs
@@ -13,7 +13,7 @@
 // @has - '//section[@id="main-content"]//div[@class="docblock"]//p' 'this is a test!'
 
 // There should be only one implementation listed.
-// @count - '//*[@class="impl has-srclink"]' 1
+// @count - '//*[@class="impl"]' 1
 // @has - '//*[@id="impl-Foo%3C%26A%3E-for-%26B"]/*[@class="code-header"]' \
 //        'impl<A, B> Foo<&A> for &B'
 #[doc(primitive = "reference")]
diff --git a/tests/rustdoc/pub-method.rs b/tests/rustdoc/pub-method.rs
index 0dca3f672cd..7115a01d079 100644
--- a/tests/rustdoc/pub-method.rs
+++ b/tests/rustdoc/pub-method.rs
@@ -10,8 +10,8 @@ pub fn bar() -> usize {
 }
 
 // @has foo/struct.Foo.html
-// @has - '//*[@class="method has-srclink"]' 'pub fn new()'
-// @has - '//*[@class="method has-srclink"]' 'fn not_pub()'
+// @has - '//*[@class="method"]' 'pub fn new()'
+// @has - '//*[@class="method"]' 'fn not_pub()'
 pub struct Foo(usize);
 
 impl Foo {
diff --git a/tests/rustdoc/reexport-check.rs b/tests/rustdoc/reexport-check.rs
index db1f90c6999..acac0c99197 100644
--- a/tests/rustdoc/reexport-check.rs
+++ b/tests/rustdoc/reexport-check.rs
@@ -4,12 +4,12 @@
 extern crate reexport_check;
 
 // @!has 'foo/index.html' '//code' 'pub use self::i32;'
-// @has 'foo/index.html' '//div[@class="item-left deprecated module-item"]' 'i32'
+// @has 'foo/index.html' '//div[@class="item-left deprecated"]' 'i32'
 // @has 'foo/i32/index.html'
 #[allow(deprecated, deprecated_in_future)]
 pub use std::i32;
 // @!has 'foo/index.html' '//code' 'pub use self::string::String;'
-// @has 'foo/index.html' '//div[@class="item-left module-item"]' 'String'
+// @has 'foo/index.html' '//div[@class="item-left"]' 'String'
 pub use std::string::String;
 
 // @has 'foo/index.html' '//div[@class="item-right docblock-short"]' 'Docs in original'
diff --git a/tests/rustdoc/synthetic_auto/basic.rs b/tests/rustdoc/synthetic_auto/basic.rs
index 7c6a388653c..043ac241488 100644
--- a/tests/rustdoc/synthetic_auto/basic.rs
+++ b/tests/rustdoc/synthetic_auto/basic.rs
@@ -1,8 +1,8 @@
 // @has basic/struct.Foo.html
 // @has - '//h3[@class="code-header"]' 'impl<T> Send for Foo<T>where T: Send'
 // @has - '//h3[@class="code-header"]' 'impl<T> Sync for Foo<T>where T: Sync'
-// @count - '//*[@id="implementations-list"]//*[@class="impl has-srclink"]' 0
-// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]' 5
+// @count - '//*[@id="implementations-list"]//*[@class="impl"]' 0
+// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]' 5
 pub struct Foo<T> {
     field: T,
 }
diff --git a/tests/rustdoc/synthetic_auto/complex.rs b/tests/rustdoc/synthetic_auto/complex.rs
index 43393c21fdd..4c39f0bf1e0 100644
--- a/tests/rustdoc/synthetic_auto/complex.rs
+++ b/tests/rustdoc/synthetic_auto/complex.rs
@@ -20,7 +20,7 @@ mod foo {
 }
 
 // @has complex/struct.NotOuter.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'a, T, K: ?Sized> Send for Outer<'a, T, K>where K: for<'b> Fn((&'b bool, &'a u8)) \
 // -> &'b i8, T: MyTrait<'a>, <T as MyTrait<'a>>::MyItem: Copy, 'a: 'static"
 
diff --git a/tests/rustdoc/synthetic_auto/lifetimes.rs b/tests/rustdoc/synthetic_auto/lifetimes.rs
index 33170a84435..71265b3078a 100644
--- a/tests/rustdoc/synthetic_auto/lifetimes.rs
+++ b/tests/rustdoc/synthetic_auto/lifetimes.rs
@@ -9,10 +9,10 @@ where
 {}
 
 // @has lifetimes/struct.Foo.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'c, K> Send for Foo<'c, K>where K: for<'b> Fn(&'b bool) -> &'c u8, 'c: 'static"
 //
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'c, K> Sync for Foo<'c, K>where K: Sync"
 pub struct Foo<'c, K: 'c> {
     inner_field: Inner<'c, K>,
diff --git a/tests/rustdoc/synthetic_auto/manual.rs b/tests/rustdoc/synthetic_auto/manual.rs
index 77c04ad2ad9..7fc8447df3e 100644
--- a/tests/rustdoc/synthetic_auto/manual.rs
+++ b/tests/rustdoc/synthetic_auto/manual.rs
@@ -1,12 +1,12 @@
 // @has manual/struct.Foo.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // 'impl<T> Sync for Foo<T>where T: Sync'
 //
-// @has - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="trait-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // 'impl<T> Send for Foo<T>'
 //
-// @count - '//*[@id="trait-implementations-list"]//*[@class="impl has-srclink"]' 1
-// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]' 4
+// @count - '//*[@id="trait-implementations-list"]//*[@class="impl"]' 1
+// @count - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]' 4
 pub struct Foo<T> {
     field: T,
 }
diff --git a/tests/rustdoc/synthetic_auto/negative.rs b/tests/rustdoc/synthetic_auto/negative.rs
index 2c2c848a5e0..97da2d57424 100644
--- a/tests/rustdoc/synthetic_auto/negative.rs
+++ b/tests/rustdoc/synthetic_auto/negative.rs
@@ -3,10 +3,10 @@ pub struct Inner<T: Copy> {
 }
 
 // @has negative/struct.Outer.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Send for Outer<T>"
 //
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Sync for Outer<T>"
 pub struct Outer<T: Copy> {
     inner_field: Inner<T>,
diff --git a/tests/rustdoc/synthetic_auto/nested.rs b/tests/rustdoc/synthetic_auto/nested.rs
index 423bf115ab1..e4aead71bf2 100644
--- a/tests/rustdoc/synthetic_auto/nested.rs
+++ b/tests/rustdoc/synthetic_auto/nested.rs
@@ -9,10 +9,10 @@ where
 }
 
 // @has nested/struct.Foo.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // 'impl<T> Send for Foo<T>where T: Copy'
 //
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // 'impl<T> Sync for Foo<T>where T: Sync'
 pub struct Foo<T> {
     inner_field: Inner<T>,
diff --git a/tests/rustdoc/synthetic_auto/no-redundancy.rs b/tests/rustdoc/synthetic_auto/no-redundancy.rs
index 59f33623322..ea57d7388b8 100644
--- a/tests/rustdoc/synthetic_auto/no-redundancy.rs
+++ b/tests/rustdoc/synthetic_auto/no-redundancy.rs
@@ -9,7 +9,7 @@ where
 }
 
 // @has no_redundancy/struct.Outer.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> Send for Outer<T>where T: Send + Copy"
 pub struct Outer<T> {
     inner_field: Inner<T>,
diff --git a/tests/rustdoc/synthetic_auto/project.rs b/tests/rustdoc/synthetic_auto/project.rs
index 558ff2add40..7c9412ae962 100644
--- a/tests/rustdoc/synthetic_auto/project.rs
+++ b/tests/rustdoc/synthetic_auto/project.rs
@@ -23,10 +23,10 @@ where
 }
 
 // @has project/struct.Foo.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'c, K> Send for Foo<'c, K>where K: MyTrait<MyItem = bool>, 'c: 'static"
 //
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'c, K> Sync for Foo<'c, K>where K: MyTrait, <K as MyTrait>::MyItem: OtherTrait, \
 // 'c: 'static,"
 pub struct Foo<'c, K: 'c> {
diff --git a/tests/rustdoc/synthetic_auto/self-referential.rs b/tests/rustdoc/synthetic_auto/self-referential.rs
index c6ae96de776..145a2b7e00c 100644
--- a/tests/rustdoc/synthetic_auto/self-referential.rs
+++ b/tests/rustdoc/synthetic_auto/self-referential.rs
@@ -23,7 +23,7 @@ impl<T> Pattern for Wrapper<T> {
 
 
 // @has self_referential/struct.WriteAndThen.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<P1> Send for WriteAndThen<P1>where    <P1 as Pattern>::Value: Send"
 pub struct WriteAndThen<P1>(pub P1::Value,pub <Constrain<P1, Wrapper<P1::Value>> as Pattern>::Value)
     where P1: Pattern;
diff --git a/tests/rustdoc/synthetic_auto/static-region.rs b/tests/rustdoc/synthetic_auto/static-region.rs
index 1a76cb919c2..9dc6211ec20 100644
--- a/tests/rustdoc/synthetic_auto/static-region.rs
+++ b/tests/rustdoc/synthetic_auto/static-region.rs
@@ -3,7 +3,7 @@ pub trait OwnedTrait<'a> {
 }
 
 // @has static_region/struct.Owned.html
-// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> Send for Owned<T>where <T as OwnedTrait<'static>>::Reader: Send"
 pub struct Owned<T> where T: OwnedTrait<'static> {
     marker: <T as OwnedTrait<'static>>::Reader,
diff --git a/tests/rustdoc/typedef.rs b/tests/rustdoc/typedef.rs
index d5dfa948489..63e2973c759 100644
--- a/tests/rustdoc/typedef.rs
+++ b/tests/rustdoc/typedef.rs
@@ -9,8 +9,8 @@ impl MyStruct {
 }
 
 // @has typedef/type.MyAlias.html
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'impl MyAlias'
-// @has - '//*[@class="impl has-srclink"]//h3[@class="code-header"]' 'impl MyTrait for MyAlias'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'impl MyAlias'
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'impl MyTrait for MyAlias'
 // @hasraw - 'Alias docstring'
 // @has - '//*[@class="sidebar"]//*[@class="location"]' 'MyAlias'
 // @has - '//*[@class="sidebar"]//a[@href="#implementations"]' 'Methods'
diff --git a/tests/rustdoc/where.rs b/tests/rustdoc/where.rs
index 3ac0c6872a8..644a0058244 100644
--- a/tests/rustdoc/where.rs
+++ b/tests/rustdoc/where.rs
@@ -13,7 +13,7 @@ pub fn charlie<C>() where C: MyTrait {}
 
 pub struct Delta<D>(D);
 
-// @has foo/struct.Delta.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has foo/struct.Delta.html '//*[@class="impl"]//h3[@class="code-header"]' \
 //          "impl<D> Delta<D>where D: MyTrait"
 impl<D> Delta<D> where D: MyTrait {
     pub fn delta() {}
@@ -43,7 +43,7 @@ pub trait TraitWhere {
     { todo!() }
 }
 
-// @has foo/struct.Echo.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has foo/struct.Echo.html '//*[@class="impl"]//h3[@class="code-header"]' \
 //          "impl<E> MyTrait for Echo<E>where E: MyTrait"
 // @has foo/trait.MyTrait.html '//*[@id="implementors-list"]//h3[@class="code-header"]' \
 //          "impl<E> MyTrait for Echo<E>where E: MyTrait"
@@ -51,7 +51,7 @@ impl<E> MyTrait for Echo<E>where E: MyTrait {}
 
 pub enum Foxtrot<F> { Foxtrot1(F) }
 
-// @has foo/enum.Foxtrot.html '//*[@class="impl has-srclink"]//h3[@class="code-header"]' \
+// @has foo/enum.Foxtrot.html '//*[@class="impl"]//h3[@class="code-header"]' \
 //          "impl<F> MyTrait for Foxtrot<F>where F: MyTrait"
 // @has foo/trait.MyTrait.html '//*[@id="implementors-list"]//h3[@class="code-header"]' \
 //          "impl<F> MyTrait for Foxtrot<F>where F: MyTrait"
diff --git a/tests/rustdoc/whitespace-after-where-clause.enum.html b/tests/rustdoc/whitespace-after-where-clause.enum.html
index 20bde549a03..eeb22878f3c 100644
--- a/tests/rustdoc/whitespace-after-where-clause.enum.html
+++ b/tests/rustdoc/whitespace-after-where-clause.enum.html
@@ -1,4 +1,4 @@
 <div class="item-decl"><pre class="rust"><code>pub enum Cow&lt;'a, B&gt;<span class="where fmt-newline">where<br />&#160;&#160;&#160;&#160;B: <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a>&lt;dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>&gt; + ?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + 'a,</span>{
-    Borrowed(<a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a </a>B),
+    Borrowed(<a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a B</a>),
     Whatever(<a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>),
 }</code></pre></div>
\ No newline at end of file
diff --git a/tests/rustdoc/whitespace-after-where-clause.enum2.html b/tests/rustdoc/whitespace-after-where-clause.enum2.html
index d9fc0c22309..c8037c2a8df 100644
--- a/tests/rustdoc/whitespace-after-where-clause.enum2.html
+++ b/tests/rustdoc/whitespace-after-where-clause.enum2.html
@@ -1,4 +1,4 @@
 <div class="item-decl"><pre class="rust"><code>pub enum Cow2&lt;'a, B:&#160;?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a>&lt;dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>&gt; + 'a&gt; {
-    Borrowed(<a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a </a>B),
+    Borrowed(<a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a B</a>),
     Whatever(<a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>),
 }</code></pre></div>
\ No newline at end of file
diff --git a/tests/rustdoc/whitespace-after-where-clause.struct.html b/tests/rustdoc/whitespace-after-where-clause.struct.html
index f375265d7c1..5892270b2f9 100644
--- a/tests/rustdoc/whitespace-after-where-clause.struct.html
+++ b/tests/rustdoc/whitespace-after-where-clause.struct.html
@@ -1,4 +1,4 @@
 <div class="item-decl"><pre class="rust"><code>pub struct Struct&lt;'a, B&gt;<span class="where fmt-newline">where<br />&#160;&#160;&#160;&#160;B: <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a>&lt;dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>&gt; + ?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + 'a,</span>{
-    pub a: <a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a </a>B,
+    pub a: <a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a B</a>,
     pub b: <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>,
 }</code></pre></div>
\ No newline at end of file
diff --git a/tests/rustdoc/whitespace-after-where-clause.struct2.html b/tests/rustdoc/whitespace-after-where-clause.struct2.html
index 1c59962eb1c..d3952b0c566 100644
--- a/tests/rustdoc/whitespace-after-where-clause.struct2.html
+++ b/tests/rustdoc/whitespace-after-where-clause.struct2.html
@@ -1,4 +1,4 @@
 <div class="item-decl"><pre class="rust"><code>pub struct Struct2&lt;'a, B:&#160;?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a>&lt;dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>&gt; + 'a&gt; {
-    pub a: <a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a </a>B,
+    pub a: <a class="primitive" href="{{channel}}/std/primitive.reference.html">&amp;'a B</a>,
     pub b: <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>,
 }</code></pre></div>
\ No newline at end of file
diff --git a/tests/ui-fulldeps/auxiliary/issue-40001-plugin.rs b/tests/ui-fulldeps/auxiliary/issue-40001-plugin.rs
index c05443488c3..3f6caecaa5a 100644
--- a/tests/ui-fulldeps/auxiliary/issue-40001-plugin.rs
+++ b/tests/ui-fulldeps/auxiliary/issue-40001-plugin.rs
@@ -16,6 +16,7 @@ use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_hir::Node;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map;
 
 #[no_mangle]
@@ -40,8 +41,9 @@ impl<'tcx> LateLintPass<'tcx> for MissingAllowedAttrPass {
         _: &'tcx hir::FnDecl,
         _: &'tcx hir::Body,
         span: source_map::Span,
-        id: hir::HirId,
+        def_id: LocalDefId,
     ) {
+        let id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
         let item = match cx.tcx.hir().get(id) {
             Node::Item(item) => item,
             _ => cx.tcx.hir().expect_item(cx.tcx.hir().get_parent_item(id).def_id),
diff --git a/tests/ui-fulldeps/dropck-tarena-cycle-checked.stderr b/tests/ui-fulldeps/dropck-tarena-cycle-checked.stderr
index 4299688221a..47897dc003a 100644
--- a/tests/ui-fulldeps/dropck-tarena-cycle-checked.stderr
+++ b/tests/ui-fulldeps/dropck-tarena-cycle-checked.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `arena` does not live long enough
   --> $DIR/dropck-tarena-cycle-checked.rs:116:7
    |
+LL |     let arena = TypedArena::default();
+   |         ----- binding `arena` declared here
 LL |     f(&arena);
    |       ^^^^^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui-fulldeps/dropck-tarena-unsound-drop.stderr b/tests/ui-fulldeps/dropck-tarena-unsound-drop.stderr
index ccffee9cdbd..493d74b0bde 100644
--- a/tests/ui-fulldeps/dropck-tarena-unsound-drop.stderr
+++ b/tests/ui-fulldeps/dropck-tarena-unsound-drop.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `arena` does not live long enough
   --> $DIR/dropck-tarena-unsound-drop.rs:41:7
    |
+LL |     let arena: TypedArena<C> = TypedArena::default();
+   |         ----- binding `arena` declared here
 LL |     f(&arena);
    |       ^^^^^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui-fulldeps/fluent-messages/missing-message-ref.ftl b/tests/ui-fulldeps/fluent-messages/missing-message-ref.ftl
new file mode 100644
index 00000000000..0cd8229b230
--- /dev/null
+++ b/tests/ui-fulldeps/fluent-messages/missing-message-ref.ftl
@@ -0,0 +1 @@
+missing_message_ref = {message}
diff --git a/tests/ui-fulldeps/fluent-messages/test.rs b/tests/ui-fulldeps/fluent-messages/test.rs
index 4e8147e2b76..74303e97dba 100644
--- a/tests/ui-fulldeps/fluent-messages/test.rs
+++ b/tests/ui-fulldeps/fluent-messages/test.rs
@@ -96,3 +96,12 @@ mod missing_crate_name {
 
     use self::fluent_generated::{DEFAULT_LOCALE_RESOURCES, test_crate_foo, with_hyphens};
 }
+
+mod missing_message_ref {
+    use super::fluent_messages;
+
+    fluent_messages! {
+        missing => "./missing-message-ref.ftl"
+//~^ ERROR referenced message `message` does not exist
+    }
+}
diff --git a/tests/ui-fulldeps/fluent-messages/test.stderr b/tests/ui-fulldeps/fluent-messages/test.stderr
index d1cd4fe26da..2631b0a6232 100644
--- a/tests/ui-fulldeps/fluent-messages/test.stderr
+++ b/tests/ui-fulldeps/fluent-messages/test.stderr
@@ -93,6 +93,14 @@ LL |         test_crate => "./missing-crate-name.ftl",
    |
    = help: replace any '-'s with '_'s
 
-error: aborting due to 10 previous errors
+error: referenced message `message` does not exist (in message `missing_message_ref`)
+  --> $DIR/test.rs:104:20
+   |
+LL |         missing => "./missing-message-ref.ftl"
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: you may have meant to use a variable reference (`{$message}`)
+
+error: aborting due to 11 previous errors
 
 For more information about this error, try `rustc --explain E0428`.
diff --git a/tests/ui-fulldeps/internal-lints/ty_tykind_usage.rs b/tests/ui-fulldeps/internal-lints/ty_tykind_usage.rs
index 3f7429a5fcc..bf655510a5a 100644
--- a/tests/ui-fulldeps/internal-lints/ty_tykind_usage.rs
+++ b/tests/ui-fulldeps/internal-lints/ty_tykind_usage.rs
@@ -31,6 +31,7 @@ fn main() {
         TyKind::Closure(..) => (),          //~ ERROR usage of `ty::TyKind::<kind>`
         TyKind::Generator(..) => (),        //~ ERROR usage of `ty::TyKind::<kind>`
         TyKind::GeneratorWitness(..) => (), //~ ERROR usage of `ty::TyKind::<kind>`
+        TyKind::GeneratorWitnessMIR(..) => (), //~ ERROR usage of `ty::TyKind::<kind>`
         TyKind::Never => (),                //~ ERROR usage of `ty::TyKind::<kind>`
         TyKind::Tuple(..) => (),            //~ ERROR usage of `ty::TyKind::<kind>`
         TyKind::Alias(..) => (),            //~ ERROR usage of `ty::TyKind::<kind>`
diff --git a/tests/ui-fulldeps/internal-lints/ty_tykind_usage.stderr b/tests/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
index 1f49d6b6464..9f8c0bea0ee 100644
--- a/tests/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
+++ b/tests/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
@@ -121,59 +121,65 @@ LL |         TyKind::GeneratorWitness(..) => (),
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:34:9
    |
-LL |         TyKind::Never => (),
+LL |         TyKind::GeneratorWitnessMIR(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:35:9
    |
-LL |         TyKind::Tuple(..) => (),
+LL |         TyKind::Never => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:36:9
    |
-LL |         TyKind::Alias(..) => (),
+LL |         TyKind::Tuple(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:37:9
    |
-LL |         TyKind::Param(..) => (),
+LL |         TyKind::Alias(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:38:9
    |
-LL |         TyKind::Bound(..) => (),
+LL |         TyKind::Param(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:39:9
    |
-LL |         TyKind::Placeholder(..) => (),
+LL |         TyKind::Bound(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:40:9
    |
-LL |         TyKind::Infer(..) => (),
+LL |         TyKind::Placeholder(..) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
   --> $DIR/ty_tykind_usage.rs:41:9
    |
+LL |         TyKind::Infer(..) => (),
+   |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
+
+error: usage of `ty::TyKind::<kind>`
+  --> $DIR/ty_tykind_usage.rs:42:9
+   |
 LL |         TyKind::Error(_) => (),
    |         ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind::<kind>`
-  --> $DIR/ty_tykind_usage.rs:46:12
+  --> $DIR/ty_tykind_usage.rs:47:12
    |
 LL |     if let TyKind::Int(int_ty) = kind {}
    |            ^^^^^^ help: try using `ty::<kind>` directly: `ty`
 
 error: usage of `ty::TyKind`
-  --> $DIR/ty_tykind_usage.rs:48:24
+  --> $DIR/ty_tykind_usage.rs:49:24
    |
 LL |     fn ty_kind(ty_bad: TyKind<'_>, ty_good: Ty<'_>) {}
    |                        ^^^^^^^^^^
@@ -181,7 +187,7 @@ LL |     fn ty_kind(ty_bad: TyKind<'_>, ty_good: Ty<'_>) {}
    = help: try using `Ty` instead
 
 error: usage of `ty::TyKind`
-  --> $DIR/ty_tykind_usage.rs:50:37
+  --> $DIR/ty_tykind_usage.rs:51:37
    |
 LL |     fn ir_ty_kind<I: Interner>(bad: IrTyKind<I>) -> IrTyKind<I> {
    |                                     ^^^^^^^^^^^
@@ -189,7 +195,7 @@ LL |     fn ir_ty_kind<I: Interner>(bad: IrTyKind<I>) -> IrTyKind<I> {
    = help: try using `Ty` instead
 
 error: usage of `ty::TyKind`
-  --> $DIR/ty_tykind_usage.rs:50:53
+  --> $DIR/ty_tykind_usage.rs:51:53
    |
 LL |     fn ir_ty_kind<I: Interner>(bad: IrTyKind<I>) -> IrTyKind<I> {
    |                                                     ^^^^^^^^^^^
@@ -197,12 +203,12 @@ LL |     fn ir_ty_kind<I: Interner>(bad: IrTyKind<I>) -> IrTyKind<I> {
    = help: try using `Ty` instead
 
 error: usage of `ty::TyKind::<kind>`
-  --> $DIR/ty_tykind_usage.rs:53:9
+  --> $DIR/ty_tykind_usage.rs:54:9
    |
 LL |         IrTyKind::Bool
    |         --------^^^^^^
    |         |
    |         help: try using `ty::<kind>` directly: `ty`
 
-error: aborting due to 32 previous errors
+error: aborting due to 33 previous errors
 
diff --git a/tests/ui/asm/type-check-4.stderr b/tests/ui/asm/type-check-4.stderr
index c97cd171b1e..b5ecb3e1b56 100644
--- a/tests/ui/asm/type-check-4.stderr
+++ b/tests/ui/asm/type-check-4.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `a` because it is borrowed
   --> $DIR/type-check-4.rs:14:9
    |
 LL |         let p = &a;
-   |                 -- borrow of `a` occurs here
+   |                 -- `a` is borrowed here
 LL |         asm!("{}", out(reg) a);
-   |         ^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `a` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^ `a` is assigned to here but it was already borrowed
 LL |
 LL |         println!("{}", p);
    |                        - borrow later used here
@@ -13,7 +13,7 @@ error[E0503]: cannot use `a` because it was mutably borrowed
   --> $DIR/type-check-4.rs:22:28
    |
 LL |         let p = &mut a;
-   |                 ------ borrow of `a` occurs here
+   |                 ------ `a` is borrowed here
 LL |         asm!("{}", in(reg) a);
    |                            ^ use of borrowed `a`
 LL |
diff --git a/tests/ui/associated-types/associated-types-outlives.stderr b/tests/ui/associated-types/associated-types-outlives.stderr
index 840e33b4b8a..2fe3f2d4a02 100644
--- a/tests/ui/associated-types/associated-types-outlives.stderr
+++ b/tests/ui/associated-types/associated-types-outlives.stderr
@@ -1,6 +1,9 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/associated-types-outlives.rs:22:14
    |
+LL |                     F: for<'a> FnOnce(<T as Foo<'a>>::Bar)>(x: T, f: F) {
+   |                                                             - binding `x` declared here
+...
 LL |         's: loop { y = denormalise(&x); break }
    |                                    -- borrow of `x` occurs here
 LL |         drop(x);
diff --git a/tests/ui/associated-types/defaults-in-other-trait-items.rs b/tests/ui/associated-types/defaults-in-other-trait-items.rs
index 505751969b6..f263809552f 100644
--- a/tests/ui/associated-types/defaults-in-other-trait-items.rs
+++ b/tests/ui/associated-types/defaults-in-other-trait-items.rs
@@ -44,4 +44,18 @@ impl AssocConst for () {
     const C: Self::Ty = 0u8;
 }
 
+pub trait Trait {
+    type Res = isize; //~ NOTE associated type defaults can't be assumed inside the trait defining them
+
+    fn infer_me_correctly() -> Self::Res {
+        //~^ NOTE expected `<Self as Trait>::Res` because of return type
+
+        // {integer} == isize
+        2
+        //~^ ERROR mismatched types
+        //~| NOTE expected associated type, found integer
+        //~| NOTE expected associated type `<Self as Trait>::Res`
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/associated-types/defaults-in-other-trait-items.stderr b/tests/ui/associated-types/defaults-in-other-trait-items.stderr
index 71d421926e7..bdcfadd3955 100644
--- a/tests/ui/associated-types/defaults-in-other-trait-items.stderr
+++ b/tests/ui/associated-types/defaults-in-other-trait-items.stderr
@@ -24,6 +24,21 @@ LL |     const C: Self::Ty = 0u8;
    = note: expected associated type `<Self as AssocConst>::Ty`
                          found type `u8`
 
-error: aborting due to 2 previous errors
+error[E0308]: mismatched types
+  --> $DIR/defaults-in-other-trait-items.rs:54:9
+   |
+LL |     type Res = isize;
+   |     ----------------- associated type defaults can't be assumed inside the trait defining them
+LL |
+LL |     fn infer_me_correctly() -> Self::Res {
+   |                                --------- expected `<Self as Trait>::Res` because of return type
+...
+LL |         2
+   |         ^ expected associated type, found integer
+   |
+   = note: expected associated type `<Self as Trait>::Res`
+                         found type `{integer}`
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/associated-types/issue-26681.stderr b/tests/ui/associated-types/issue-26681.stderr
index 74411008c9d..977620d9052 100644
--- a/tests/ui/associated-types/issue-26681.stderr
+++ b/tests/ui/associated-types/issue-26681.stderr
@@ -1,13 +1,13 @@
 error[E0308]: mismatched types
   --> $DIR/issue-26681.rs:17:39
    |
+LL |     type Fv: Foo = u8;
+   |     ------------------ associated type defaults can't be assumed inside the trait defining them
 LL |     const C: <Self::Fv as Foo>::Bar = 6665;
    |                                       ^^^^ expected associated type, found integer
    |
    = note: expected associated type `<<Self as Baz>::Fv as Foo>::Bar`
                          found type `{integer}`
-   = help: consider constraining the associated type `<<Self as Baz>::Fv as Foo>::Bar` to `{integer}`
-   = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error: aborting due to previous error
 
diff --git a/tests/ui/async-await/async-await-let-else.drop_tracking.stderr b/tests/ui/async-await/async-await-let-else.drop_tracking.stderr
new file mode 100644
index 00000000000..fb83ca90a37
--- /dev/null
+++ b/tests/ui/async-await/async-await-let-else.drop_tracking.stderr
@@ -0,0 +1,106 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:48:13
+   |
+LL |     is_send(foo(Some(true)));
+   |             ^^^^^^^^^^^^^^^ future returned by `foo` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:11:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+LL |     };
+   |     - `r` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error[E0277]: `Rc<()>` cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:50:13
+   |
+LL | async fn foo2(x: Option<bool>) {
+   |                                - within this `impl Future<Output = ()>`
+...
+LL |     is_send(foo2(Some(true)));
+   |     ------- ^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: required because it's used within this `async fn` body
+  --> $DIR/async-await-let-else.rs:27:29
+   |
+LL |   async fn bar2<T>(_: T) -> ! {
+   |  _____________________________^
+LL | |     panic!()
+LL | | }
+   | |_^
+   = note: required because it captures the following types: `ResumeTy`, `Option<bool>`, `impl Future<Output = !>`, `()`
+note: required because it's used within this `async fn` body
+  --> $DIR/async-await-let-else.rs:21:32
+   |
+LL |   async fn foo2(x: Option<bool>) {
+   |  ________________________________^
+LL | |     let Some(_) = x else {
+LL | |         bar2(Rc::new(())).await
+LL | |     };
+LL | | }
+   | |_^
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:52:13
+   |
+LL |     is_send(foo3(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo3` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:33:28
+   |
+LL |         (Rc::new(()), bar().await);
+   |          -----------       ^^^^^^ - `Rc::new(())` is later dropped here
+   |          |                 |
+   |          |                 await occurs here, with `Rc::new(())` maybe used later
+   |          has type `Rc<()>` which is not `Send`
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:54:13
+   |
+LL |     is_send(foo4(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo4` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:41:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await;
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+...
+LL |     };
+   |     - `r` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/async-await-let-else.drop_tracking_mir.stderr b/tests/ui/async-await/async-await-let-else.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..c284bbfb1cc
--- /dev/null
+++ b/tests/ui/async-await/async-await-let-else.drop_tracking_mir.stderr
@@ -0,0 +1,100 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:48:13
+   |
+LL |     is_send(foo(Some(true)));
+   |             ^^^^^^^^^^^^^^^ future returned by `foo` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:11:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error[E0277]: `Rc<()>` cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:50:13
+   |
+LL | async fn foo2(x: Option<bool>) {
+   |                                - within this `impl Future<Output = ()>`
+...
+LL |     is_send(foo2(Some(true)));
+   |     ------- ^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: required because it's used within this `async fn` body
+  --> $DIR/async-await-let-else.rs:27:29
+   |
+LL |   async fn bar2<T>(_: T) -> ! {
+   |  _____________________________^
+LL | |     panic!()
+LL | | }
+   | |_^
+   = note: required because it captures the following types: `impl Future<Output = !>`
+note: required because it's used within this `async fn` body
+  --> $DIR/async-await-let-else.rs:21:32
+   |
+LL |   async fn foo2(x: Option<bool>) {
+   |  ________________________________^
+LL | |     let Some(_) = x else {
+LL | |         bar2(Rc::new(())).await
+LL | |     };
+LL | | }
+   | |_^
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:52:13
+   |
+LL |     is_send(foo3(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo3` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:33:28
+   |
+LL |         (Rc::new(()), bar().await);
+   |          -----------       ^^^^^^ await occurs here, with `Rc::new(())` maybe used later
+   |          |
+   |          has type `Rc<()>` which is not `Send`
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:54:13
+   |
+LL |     is_send(foo4(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo4` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:41:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await;
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/async-await-let-else.no_drop_tracking.stderr b/tests/ui/async-await/async-await-let-else.no_drop_tracking.stderr
new file mode 100644
index 00000000000..d3c5e80a30d
--- /dev/null
+++ b/tests/ui/async-await/async-await-let-else.no_drop_tracking.stderr
@@ -0,0 +1,90 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:48:13
+   |
+LL |     is_send(foo(Some(true)));
+   |             ^^^^^^^^^^^^^^^ future returned by `foo` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:11:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+LL |     };
+   |     - `r` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:50:13
+   |
+LL |     is_send(foo2(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo2` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:23:26
+   |
+LL |         bar2(Rc::new(())).await
+   |              ----------- ^^^^^^ await occurs here, with `Rc::new(())` maybe used later
+   |              |
+   |              has type `Rc<()>` which is not `Send`
+LL |     };
+   |     - `Rc::new(())` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:52:13
+   |
+LL |     is_send(foo3(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo3` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:33:28
+   |
+LL |         (Rc::new(()), bar().await);
+   |          -----------       ^^^^^^ - `Rc::new(())` is later dropped here
+   |          |                 |
+   |          |                 await occurs here, with `Rc::new(())` maybe used later
+   |          has type `Rc<()>` which is not `Send`
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-await-let-else.rs:54:13
+   |
+LL |     is_send(foo4(Some(true)));
+   |             ^^^^^^^^^^^^^^^^ future returned by `foo4` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-await-let-else.rs:41:14
+   |
+LL |         let r = Rc::new(());
+   |             - has type `Rc<()>` which is not `Send`
+LL |         bar().await;
+   |              ^^^^^^ await occurs here, with `r` maybe used later
+...
+LL |     };
+   |     - `r` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/async-await-let-else.rs:19:15
+   |
+LL | fn is_send<T: Send>(_: T) {}
+   |               ^^^^ required by this bound in `is_send`
+
+error: aborting due to 4 previous errors
+
diff --git a/tests/ui/async-await/async-await-let-else.rs b/tests/ui/async-await/async-await-let-else.rs
index 3fb2142b9e5..113d576b5e7 100644
--- a/tests/ui/async-await/async-await-let-else.rs
+++ b/tests/ui/async-await/async-await-let-else.rs
@@ -1,7 +1,7 @@
 // edition:2021
-// revisions: drop-tracking no-drop-tracking
-// [drop-tracking] compile-flags: -Zdrop-tracking=yes
-// [no-drop-tracking] compile-flags: -Zdrop-tracking=no
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 
 use std::rc::Rc;
 
diff --git a/tests/ui/async-await/async-error-span.stderr b/tests/ui/async-await/async-error-span.drop_tracking.stderr
index 7d4447b6d55..c6257cb324d 100644
--- a/tests/ui/async-await/async-error-span.stderr
+++ b/tests/ui/async-await/async-error-span.drop_tracking.stderr
@@ -1,5 +1,5 @@
 error[E0277]: `()` is not a future
-  --> $DIR/async-error-span.rs:7:20
+  --> $DIR/async-error-span.rs:10:20
    |
 LL | fn get_future() -> impl Future<Output = ()> {
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^ `()` is not a future
@@ -8,13 +8,13 @@ LL | fn get_future() -> impl Future<Output = ()> {
    = note: () must be a future or must implement `IntoFuture` to be awaited
 
 error[E0698]: type inside `async fn` body must be known in this context
-  --> $DIR/async-error-span.rs:13:9
+  --> $DIR/async-error-span.rs:16:9
    |
 LL |     let a;
    |         ^ cannot infer type
    |
 note: the type is part of the `async fn` body because of this `await`
-  --> $DIR/async-error-span.rs:14:17
+  --> $DIR/async-error-span.rs:19:17
    |
 LL |     get_future().await;
    |                 ^^^^^^
diff --git a/tests/ui/async-await/async-error-span.drop_tracking_mir.stderr b/tests/ui/async-await/async-error-span.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..2f29ee6cdb0
--- /dev/null
+++ b/tests/ui/async-await/async-error-span.drop_tracking_mir.stderr
@@ -0,0 +1,24 @@
+error[E0277]: `()` is not a future
+  --> $DIR/async-error-span.rs:10:20
+   |
+LL | fn get_future() -> impl Future<Output = ()> {
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^ `()` is not a future
+   |
+   = help: the trait `Future` is not implemented for `()`
+   = note: () must be a future or must implement `IntoFuture` to be awaited
+
+error[E0282]: type annotations needed
+  --> $DIR/async-error-span.rs:16:9
+   |
+LL |     let a;
+   |         ^
+   |
+help: consider giving `a` an explicit type
+   |
+LL |     let a: /* Type */;
+   |          ++++++++++++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0282.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/async-error-span.no_drop_tracking.stderr b/tests/ui/async-await/async-error-span.no_drop_tracking.stderr
new file mode 100644
index 00000000000..c6257cb324d
--- /dev/null
+++ b/tests/ui/async-await/async-error-span.no_drop_tracking.stderr
@@ -0,0 +1,25 @@
+error[E0277]: `()` is not a future
+  --> $DIR/async-error-span.rs:10:20
+   |
+LL | fn get_future() -> impl Future<Output = ()> {
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^ `()` is not a future
+   |
+   = help: the trait `Future` is not implemented for `()`
+   = note: () must be a future or must implement `IntoFuture` to be awaited
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/async-error-span.rs:16:9
+   |
+LL |     let a;
+   |         ^ cannot infer type
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/async-error-span.rs:19:17
+   |
+LL |     get_future().await;
+   |                 ^^^^^^
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0698.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/async-error-span.rs b/tests/ui/async-await/async-error-span.rs
index 86d459bf084..c9ecf359e3d 100644
--- a/tests/ui/async-await/async-error-span.rs
+++ b/tests/ui/async-await/async-error-span.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 
 // Regression test for issue #62382.
@@ -10,7 +13,9 @@ fn get_future() -> impl Future<Output = ()> {
 }
 
 async fn foo() {
-    let a; //~ ERROR type inside `async fn` body must be known in this context
+    let a;
+    //[no_drop_tracking,drop_tracking]~^ ERROR type inside `async fn` body must be known in this context
+    //[drop_tracking_mir]~^^ ERROR type annotations needed
     get_future().await;
 }
 
diff --git a/tests/ui/async-await/async-fn-nonsend.drop_tracking.stderr b/tests/ui/async-await/async-fn-nonsend.drop_tracking.stderr
new file mode 100644
index 00000000000..0f0dc335e7f
--- /dev/null
+++ b/tests/ui/async-await/async-fn-nonsend.drop_tracking.stderr
@@ -0,0 +1,49 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:72:17
+   |
+LL |     assert_send(non_send_temporary_in_match());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:36:25
+   |
+LL |     match Some(non_send()) {
+   |           ---------------- has type `Option<impl Debug>` which is not `Send`
+LL |         Some(_) => fut().await,
+   |                         ^^^^^^ await occurs here, with `Some(non_send())` maybe used later
+...
+LL | }
+   | - `Some(non_send())` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:74:17
+   |
+LL |     assert_send(non_sync_with_method_call());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:49:14
+   |
+LL |     let f: &mut std::fmt::Formatter = &mut get_formatter();
+   |                                            --------------- has type `Formatter<'_>` which is not `Send`
+...
+LL |         fut().await;
+   |              ^^^^^^ await occurs here, with `get_formatter()` maybe used later
+LL |     }
+LL | }
+   | - `get_formatter()` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/async-await/async-fn-nonsend.drop_tracking_mir.stderr b/tests/ui/async-await/async-fn-nonsend.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..57a01280145
--- /dev/null
+++ b/tests/ui/async-await/async-fn-nonsend.drop_tracking_mir.stderr
@@ -0,0 +1,43 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:72:17
+   |
+LL |     assert_send(non_send_temporary_in_match());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:36:25
+   |
+LL |     match Some(non_send()) {
+   |           ---------------- has type `Option<impl Debug>` which is not `Send`
+LL |         Some(_) => fut().await,
+   |                         ^^^^^^ await occurs here, with `Some(non_send())` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:74:17
+   |
+LL |     assert_send(non_sync_with_method_call());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:49:14
+   |
+LL |     let f: &mut std::fmt::Formatter = &mut get_formatter();
+   |                                            --------------- has type `Formatter<'_>` which is not `Send`
+...
+LL |         fut().await;
+   |              ^^^^^^ await occurs here, with `get_formatter()` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/async-await/async-fn-nonsend.no_drop_tracking.stderr b/tests/ui/async-await/async-fn-nonsend.no_drop_tracking.stderr
new file mode 100644
index 00000000000..5cec21d890e
--- /dev/null
+++ b/tests/ui/async-await/async-fn-nonsend.no_drop_tracking.stderr
@@ -0,0 +1,120 @@
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:70:17
+   |
+LL |     assert_send(local_dropped_before_await());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `local_dropped_before_await` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:27:10
+   |
+LL |     let x = non_send();
+   |         - has type `impl Debug` which is not `Send`
+LL |     drop(x);
+LL |     fut().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:72:17
+   |
+LL |     assert_send(non_send_temporary_in_match());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:36:25
+   |
+LL |     match Some(non_send()) {
+   |                ---------- has type `impl Debug` which is not `Send`
+LL |         Some(_) => fut().await,
+   |                         ^^^^^^ await occurs here, with `non_send()` maybe used later
+...
+LL | }
+   | - `non_send()` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:74:17
+   |
+LL |     assert_send(non_sync_with_method_call());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:49:14
+   |
+LL |     let f: &mut std::fmt::Formatter = &mut get_formatter();
+   |                                            --------------- has type `Formatter<'_>` which is not `Send`
+...
+LL |         fut().await;
+   |              ^^^^^^ await occurs here, with `get_formatter()` maybe used later
+LL |     }
+LL | }
+   | - `get_formatter()` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:76:17
+   |
+LL |     assert_send(non_sync_with_method_call_panic());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call_panic` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:56:14
+   |
+LL |     let f: &mut std::fmt::Formatter = panic!();
+   |         - has type `&mut Formatter<'_>` which is not `Send`
+LL |     if non_sync().fmt(f).unwrap() == () {
+LL |         fut().await;
+   |              ^^^^^^ await occurs here, with `f` maybe used later
+LL |     }
+LL | }
+   | - `f` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/async-fn-nonsend.rs:78:17
+   |
+LL |     assert_send(non_sync_with_method_call_infinite_loop());
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call_infinite_loop` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/async-fn-nonsend.rs:63:14
+   |
+LL |     let f: &mut std::fmt::Formatter = loop {};
+   |         - has type `&mut Formatter<'_>` which is not `Send`
+LL |     if non_sync().fmt(f).unwrap() == () {
+LL |         fut().await;
+   |              ^^^^^^ await occurs here, with `f` maybe used later
+LL |     }
+LL | }
+   | - `f` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/async-fn-nonsend.rs:67:24
+   |
+LL | fn assert_send(_: impl Send) {}
+   |                        ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 5 previous errors
+
diff --git a/tests/ui/async-await/async-fn-nonsend.rs b/tests/ui/async-await/async-fn-nonsend.rs
index d7f8d7ac546..ed440bd0182 100644
--- a/tests/ui/async-await/async-fn-nonsend.rs
+++ b/tests/ui/async-await/async-fn-nonsend.rs
@@ -1,5 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
-// compile-flags: --crate-type lib -Zdrop-tracking
+// compile-flags: --crate-type lib
 
 use std::{cell::RefCell, fmt::Debug, rc::Rc};
 
@@ -65,10 +68,13 @@ fn assert_send(_: impl Send) {}
 
 pub fn pass_assert() {
     assert_send(local_dropped_before_await());
+    //[no_drop_tracking]~^ ERROR future cannot be sent between threads safely
     assert_send(non_send_temporary_in_match());
     //~^ ERROR future cannot be sent between threads safely
     assert_send(non_sync_with_method_call());
     //~^ ERROR future cannot be sent between threads safely
     assert_send(non_sync_with_method_call_panic());
+    //[no_drop_tracking]~^ ERROR future cannot be sent between threads safely
     assert_send(non_sync_with_method_call_infinite_loop());
+    //[no_drop_tracking]~^ ERROR future cannot be sent between threads safely
 }
diff --git a/tests/ui/async-await/async-fn-nonsend.stderr b/tests/ui/async-await/async-fn-nonsend.stderr
index a7b872fe444..0f0dc335e7f 100644
--- a/tests/ui/async-await/async-fn-nonsend.stderr
+++ b/tests/ui/async-await/async-fn-nonsend.stderr
@@ -1,12 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/async-fn-nonsend.rs:68:17
+  --> $DIR/async-fn-nonsend.rs:72:17
    |
 LL |     assert_send(non_send_temporary_in_match());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/async-fn-nonsend.rs:33:25
+  --> $DIR/async-fn-nonsend.rs:36:25
    |
 LL |     match Some(non_send()) {
    |           ---------------- has type `Option<impl Debug>` which is not `Send`
@@ -16,20 +16,20 @@ LL |         Some(_) => fut().await,
 LL | }
    | - `Some(non_send())` is later dropped here
 note: required by a bound in `assert_send`
-  --> $DIR/async-fn-nonsend.rs:64:24
+  --> $DIR/async-fn-nonsend.rs:67:24
    |
 LL | fn assert_send(_: impl Send) {}
    |                        ^^^^ required by this bound in `assert_send`
 
 error: future cannot be sent between threads safely
-  --> $DIR/async-fn-nonsend.rs:70:17
+  --> $DIR/async-fn-nonsend.rs:74:17
    |
 LL |     assert_send(non_sync_with_method_call());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/async-fn-nonsend.rs:46:14
+  --> $DIR/async-fn-nonsend.rs:49:14
    |
 LL |     let f: &mut std::fmt::Formatter = &mut get_formatter();
    |                                            --------------- has type `Formatter<'_>` which is not `Send`
@@ -40,7 +40,7 @@ LL |     }
 LL | }
    | - `get_formatter()` is later dropped here
 note: required by a bound in `assert_send`
-  --> $DIR/async-fn-nonsend.rs:64:24
+  --> $DIR/async-fn-nonsend.rs:67:24
    |
 LL | fn assert_send(_: impl Send) {}
    |                        ^^^^ required by this bound in `assert_send`
diff --git a/tests/ui/async-await/default-struct-update.rs b/tests/ui/async-await/default-struct-update.rs
index 64fb6280dd7..daee8469a14 100644
--- a/tests/ui/async-await/default-struct-update.rs
+++ b/tests/ui/async-await/default-struct-update.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // build-pass
 // edition:2018
-// compile-flags: -Zdrop-tracking=y
 
 fn main() {
     let _ = foo();
diff --git a/tests/ui/async-await/drop-and-assign.rs b/tests/ui/async-await/drop-and-assign.rs
index fa3f3303677..e520dfbdcce 100644
--- a/tests/ui/async-await/drop-and-assign.rs
+++ b/tests/ui/async-await/drop-and-assign.rs
@@ -1,5 +1,7 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2021
-// compile-flags: -Zdrop-tracking
 // build-pass
 
 struct A;
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr b/tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking.stderr
index d95483c8119..e2bba812d05 100644
--- a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
+++ b/tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking.stderr
@@ -1,12 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/drop-track-field-assign-nonsend.rs:43:17
+  --> $DIR/drop-track-field-assign-nonsend.rs:45:17
    |
 LL |     assert_send(agent.handle());
    |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/drop-track-field-assign-nonsend.rs:21:38
+  --> $DIR/drop-track-field-assign-nonsend.rs:23:38
    |
 LL |         let mut info = self.info_result.clone();
    |             -------- has type `InfoResult` which is not `Send`
@@ -16,7 +16,7 @@ LL |         let _ = send_element(element).await;
 LL |     }
    |     - `mut info` is later dropped here
 note: required by a bound in `assert_send`
-  --> $DIR/drop-track-field-assign-nonsend.rs:38:19
+  --> $DIR/drop-track-field-assign-nonsend.rs:40:19
    |
 LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking_mir.stderr b/tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..b89d8680407
--- /dev/null
+++ b/tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking_mir.stderr
@@ -0,0 +1,23 @@
+error: future cannot be sent between threads safely
+  --> $DIR/drop-track-field-assign-nonsend.rs:45:17
+   |
+LL |     assert_send(agent.handle());
+   |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/drop-track-field-assign-nonsend.rs:23:38
+   |
+LL |         let mut info = self.info_result.clone();
+   |             -------- has type `InfoResult` which is not `Send`
+...
+LL |         let _ = send_element(element).await;
+   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/drop-track-field-assign-nonsend.rs:40:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.no_drop_tracking.stderr b/tests/ui/async-await/drop-track-field-assign-nonsend.no_drop_tracking.stderr
new file mode 100644
index 00000000000..e2bba812d05
--- /dev/null
+++ b/tests/ui/async-await/drop-track-field-assign-nonsend.no_drop_tracking.stderr
@@ -0,0 +1,25 @@
+error: future cannot be sent between threads safely
+  --> $DIR/drop-track-field-assign-nonsend.rs:45:17
+   |
+LL |     assert_send(agent.handle());
+   |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/drop-track-field-assign-nonsend.rs:23:38
+   |
+LL |         let mut info = self.info_result.clone();
+   |             -------- has type `InfoResult` which is not `Send`
+...
+LL |         let _ = send_element(element).await;
+   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+LL |     }
+   |     - `mut info` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/drop-track-field-assign-nonsend.rs:40:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.rs b/tests/ui/async-await/drop-track-field-assign-nonsend.rs
index b6c0fda1521..3e22280008f 100644
--- a/tests/ui/async-await/drop-track-field-assign-nonsend.rs
+++ b/tests/ui/async-await/drop-track-field-assign-nonsend.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // Derived from an ICE found in tokio-xmpp during a crater run.
 // edition:2021
-// compile-flags: -Zdrop-tracking
 
 #![allow(dead_code)]
 
diff --git a/tests/ui/async-await/drop-track-field-assign.rs b/tests/ui/async-await/drop-track-field-assign.rs
index 3a393cd164b..dd0e3f11ccc 100644
--- a/tests/ui/async-await/drop-track-field-assign.rs
+++ b/tests/ui/async-await/drop-track-field-assign.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // Derived from an ICE found in tokio-xmpp during a crater run.
 // edition:2021
-// compile-flags: -Zdrop-tracking
 // build-pass
 
 #![allow(dead_code)]
diff --git a/tests/ui/async-await/field-assign-nonsend.drop_tracking.stderr b/tests/ui/async-await/field-assign-nonsend.drop_tracking.stderr
new file mode 100644
index 00000000000..ac461a671a8
--- /dev/null
+++ b/tests/ui/async-await/field-assign-nonsend.drop_tracking.stderr
@@ -0,0 +1,25 @@
+error: future cannot be sent between threads safely
+  --> $DIR/field-assign-nonsend.rs:45:17
+   |
+LL |     assert_send(agent.handle());
+   |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/field-assign-nonsend.rs:23:38
+   |
+LL |         let mut info = self.info_result.clone();
+   |             -------- has type `InfoResult` which is not `Send`
+...
+LL |         let _ = send_element(element).await;
+   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+LL |     }
+   |     - `mut info` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/field-assign-nonsend.rs:40:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/field-assign-nonsend.drop_tracking_mir.stderr b/tests/ui/async-await/field-assign-nonsend.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..8c9d14d624c
--- /dev/null
+++ b/tests/ui/async-await/field-assign-nonsend.drop_tracking_mir.stderr
@@ -0,0 +1,23 @@
+error: future cannot be sent between threads safely
+  --> $DIR/field-assign-nonsend.rs:45:17
+   |
+LL |     assert_send(agent.handle());
+   |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/field-assign-nonsend.rs:23:38
+   |
+LL |         let mut info = self.info_result.clone();
+   |             -------- has type `InfoResult` which is not `Send`
+...
+LL |         let _ = send_element(element).await;
+   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/field-assign-nonsend.rs:40:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/field-assign-nonsend.no_drop_tracking.stderr b/tests/ui/async-await/field-assign-nonsend.no_drop_tracking.stderr
new file mode 100644
index 00000000000..ac461a671a8
--- /dev/null
+++ b/tests/ui/async-await/field-assign-nonsend.no_drop_tracking.stderr
@@ -0,0 +1,25 @@
+error: future cannot be sent between threads safely
+  --> $DIR/field-assign-nonsend.rs:45:17
+   |
+LL |     assert_send(agent.handle());
+   |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/field-assign-nonsend.rs:23:38
+   |
+LL |         let mut info = self.info_result.clone();
+   |             -------- has type `InfoResult` which is not `Send`
+...
+LL |         let _ = send_element(element).await;
+   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+LL |     }
+   |     - `mut info` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/field-assign-nonsend.rs:40:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/field-assign-nonsend.rs b/tests/ui/async-await/field-assign-nonsend.rs
new file mode 100644
index 00000000000..3e22280008f
--- /dev/null
+++ b/tests/ui/async-await/field-assign-nonsend.rs
@@ -0,0 +1,47 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// Derived from an ICE found in tokio-xmpp during a crater run.
+// edition:2021
+
+#![allow(dead_code)]
+
+#[derive(Clone)]
+struct InfoResult {
+    node: Option<std::rc::Rc<String>>
+}
+
+struct Agent {
+    info_result: InfoResult
+}
+
+impl Agent {
+    async fn handle(&mut self) {
+        let mut info = self.info_result.clone();
+        info.node = None;
+        let element = parse_info(info);
+        let _ = send_element(element).await;
+    }
+}
+
+struct Element {
+}
+
+async fn send_element(_: Element) {}
+
+fn parse(_: &[u8]) -> Result<(), ()> {
+    Ok(())
+}
+
+fn parse_info(_: InfoResult) -> Element {
+    Element { }
+}
+
+fn assert_send<T: Send>(_: T) {}
+
+fn main() {
+    let agent = Agent { info_result: InfoResult { node: None } };
+    // FIXME: It would be nice for this to work. See #94067.
+    assert_send(agent.handle());
+    //~^ cannot be sent between threads safely
+}
diff --git a/tests/ui/async-await/field-assign.rs b/tests/ui/async-await/field-assign.rs
new file mode 100644
index 00000000000..dd0e3f11ccc
--- /dev/null
+++ b/tests/ui/async-await/field-assign.rs
@@ -0,0 +1,46 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// Derived from an ICE found in tokio-xmpp during a crater run.
+// edition:2021
+// build-pass
+
+#![allow(dead_code)]
+
+#[derive(Clone)]
+struct InfoResult {
+    node: Option<String>
+}
+
+struct Agent {
+    info_result: InfoResult
+}
+
+impl Agent {
+    async fn handle(&mut self) {
+        let mut info = self.info_result.clone();
+        info.node = Some("bar".into());
+        let element = parse_info(info);
+        let _ = send_element(element).await;
+    }
+}
+
+struct Element {
+}
+
+async fn send_element(_: Element) {}
+
+fn parse(_: &[u8]) -> Result<(), ()> {
+    Ok(())
+}
+
+fn parse_info(_: InfoResult) -> Element {
+    Element { }
+}
+
+fn main() {
+    let mut agent = Agent {
+        info_result: InfoResult { node: None }
+    };
+    let _ = agent.handle();
+}
diff --git a/tests/ui/async-await/issue-64130-1-sync.drop_tracking.stderr b/tests/ui/async-await/issue-64130-1-sync.drop_tracking.stderr
new file mode 100644
index 00000000000..c4c7f26c7c7
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-1-sync.drop_tracking.stderr
@@ -0,0 +1,25 @@
+error: future cannot be shared between threads safely
+  --> $DIR/issue-64130-1-sync.rs:25:13
+   |
+LL |     is_sync(bar());
+   |             ^^^^^ future returned by `bar` is not `Sync`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`
+note: future is not `Sync` as this value is used across an await
+  --> $DIR/issue-64130-1-sync.rs:18:10
+   |
+LL |     let x = Foo;
+   |         - has type `Foo` which is not `Sync`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL |     drop(x);
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_sync`
+  --> $DIR/issue-64130-1-sync.rs:14:15
+   |
+LL | fn is_sync<T: Sync>(t: T) { }
+   |               ^^^^ required by this bound in `is_sync`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-1-sync.drop_tracking_mir.stderr b/tests/ui/async-await/issue-64130-1-sync.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..6f43b568a7a
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-1-sync.drop_tracking_mir.stderr
@@ -0,0 +1,22 @@
+error: future cannot be shared between threads safely
+  --> $DIR/issue-64130-1-sync.rs:25:13
+   |
+LL |     is_sync(bar());
+   |             ^^^^^ future returned by `bar` is not `Sync`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`
+note: future is not `Sync` as this value is used across an await
+  --> $DIR/issue-64130-1-sync.rs:18:10
+   |
+LL |     let x = Foo;
+   |         - has type `Foo` which is not `Sync`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+note: required by a bound in `is_sync`
+  --> $DIR/issue-64130-1-sync.rs:14:15
+   |
+LL | fn is_sync<T: Sync>(t: T) { }
+   |               ^^^^ required by this bound in `is_sync`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-1-sync.no_drop_tracking.stderr b/tests/ui/async-await/issue-64130-1-sync.no_drop_tracking.stderr
new file mode 100644
index 00000000000..c4c7f26c7c7
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-1-sync.no_drop_tracking.stderr
@@ -0,0 +1,25 @@
+error: future cannot be shared between threads safely
+  --> $DIR/issue-64130-1-sync.rs:25:13
+   |
+LL |     is_sync(bar());
+   |             ^^^^^ future returned by `bar` is not `Sync`
+   |
+   = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`
+note: future is not `Sync` as this value is used across an await
+  --> $DIR/issue-64130-1-sync.rs:18:10
+   |
+LL |     let x = Foo;
+   |         - has type `Foo` which is not `Sync`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL |     drop(x);
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_sync`
+  --> $DIR/issue-64130-1-sync.rs:14:15
+   |
+LL | fn is_sync<T: Sync>(t: T) { }
+   |               ^^^^ required by this bound in `is_sync`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-1-sync.rs b/tests/ui/async-await/issue-64130-1-sync.rs
index 1714cec5221..44646e0e5f2 100644
--- a/tests/ui/async-await/issue-64130-1-sync.rs
+++ b/tests/ui/async-await/issue-64130-1-sync.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(negative_impls)]
 // edition:2018
 
@@ -13,6 +16,7 @@ fn is_sync<T: Sync>(t: T) { }
 async fn bar() {
     let x = Foo;
     baz().await;
+    drop(x);
 }
 
 async fn baz() { }
diff --git a/tests/ui/async-await/issue-64130-1-sync.stderr b/tests/ui/async-await/issue-64130-1-sync.stderr
index e205de4738f..8d5169a6302 100644
--- a/tests/ui/async-await/issue-64130-1-sync.stderr
+++ b/tests/ui/async-await/issue-64130-1-sync.stderr
@@ -1,12 +1,12 @@
 error: future cannot be shared between threads safely
-  --> $DIR/issue-64130-1-sync.rs:21:13
+  --> $DIR/issue-64130-1-sync.rs:24:13
    |
 LL |     is_sync(bar());
    |             ^^^^^ future returned by `bar` is not `Sync`
    |
    = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`
 note: future is not `Sync` as this value is used across an await
-  --> $DIR/issue-64130-1-sync.rs:15:10
+  --> $DIR/issue-64130-1-sync.rs:18:10
    |
 LL |     let x = Foo;
    |         - has type `Foo` which is not `Sync`
@@ -15,7 +15,7 @@ LL |     baz().await;
 LL | }
    | - `x` is later dropped here
 note: required by a bound in `is_sync`
-  --> $DIR/issue-64130-1-sync.rs:11:15
+  --> $DIR/issue-64130-1-sync.rs:14:15
    |
 LL | fn is_sync<T: Sync>(t: T) { }
    |               ^^^^ required by this bound in `is_sync`
diff --git a/tests/ui/async-await/issue-64130-2-send.drop_tracking.stderr b/tests/ui/async-await/issue-64130-2-send.drop_tracking.stderr
new file mode 100644
index 00000000000..b6a73c2a5cb
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-2-send.drop_tracking.stderr
@@ -0,0 +1,28 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-64130-2-send.rs:24:13
+   |
+LL |     is_send(bar());
+   |             ^^^^^ future returned by `bar` is not `Send`
+   |
+   = note: the trait bound `Unique<Foo>: Send` is not satisfied
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-64130-2-send.rs:18:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which is not `Send`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/issue-64130-2-send.rs:14:15
+   |
+LL | fn is_send<T: Send>(t: T) { }
+   |               ^^^^ required by this bound in `is_send`
+help: consider borrowing here
+   |
+LL |     is_send(&bar());
+   |             +
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-2-send.drop_tracking_mir.stderr b/tests/ui/async-await/issue-64130-2-send.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..560560f6036
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-2-send.drop_tracking_mir.stderr
@@ -0,0 +1,26 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-64130-2-send.rs:24:13
+   |
+LL |     is_send(bar());
+   |             ^^^^^ future returned by `bar` is not `Send`
+   |
+   = note: the trait bound `Unique<Foo>: Send` is not satisfied
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-64130-2-send.rs:18:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which is not `Send`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+note: required by a bound in `is_send`
+  --> $DIR/issue-64130-2-send.rs:14:15
+   |
+LL | fn is_send<T: Send>(t: T) { }
+   |               ^^^^ required by this bound in `is_send`
+help: consider borrowing here
+   |
+LL |     is_send(&bar());
+   |             +
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-2-send.no_drop_tracking.stderr b/tests/ui/async-await/issue-64130-2-send.no_drop_tracking.stderr
new file mode 100644
index 00000000000..b6a73c2a5cb
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-2-send.no_drop_tracking.stderr
@@ -0,0 +1,28 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-64130-2-send.rs:24:13
+   |
+LL |     is_send(bar());
+   |             ^^^^^ future returned by `bar` is not `Send`
+   |
+   = note: the trait bound `Unique<Foo>: Send` is not satisfied
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-64130-2-send.rs:18:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which is not `Send`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_send`
+  --> $DIR/issue-64130-2-send.rs:14:15
+   |
+LL | fn is_send<T: Send>(t: T) { }
+   |               ^^^^ required by this bound in `is_send`
+help: consider borrowing here
+   |
+LL |     is_send(&bar());
+   |             +
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-64130-2-send.rs b/tests/ui/async-await/issue-64130-2-send.rs
index 7a6e5952cb9..d6d855bac07 100644
--- a/tests/ui/async-await/issue-64130-2-send.rs
+++ b/tests/ui/async-await/issue-64130-2-send.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(negative_impls)]
 // edition:2018
 
@@ -11,7 +14,7 @@ impl !Send for Foo {}
 fn is_send<T: Send>(t: T) { }
 
 async fn bar() {
-    let x = Foo;
+    let x = Box::new(Foo);
     baz().await;
 }
 
diff --git a/tests/ui/async-await/issue-64130-2-send.stderr b/tests/ui/async-await/issue-64130-2-send.stderr
index 2225000e2e5..f6505cad69e 100644
--- a/tests/ui/async-await/issue-64130-2-send.stderr
+++ b/tests/ui/async-await/issue-64130-2-send.stderr
@@ -1,12 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-64130-2-send.rs:21:13
+  --> $DIR/issue-64130-2-send.rs:24:13
    |
 LL |     is_send(bar());
    |             ^^^^^ future returned by `bar` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Foo`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/issue-64130-2-send.rs:15:10
+  --> $DIR/issue-64130-2-send.rs:18:10
    |
 LL |     let x = Foo;
    |         - has type `Foo` which is not `Send`
@@ -15,7 +15,7 @@ LL |     baz().await;
 LL | }
    | - `x` is later dropped here
 note: required by a bound in `is_send`
-  --> $DIR/issue-64130-2-send.rs:11:15
+  --> $DIR/issue-64130-2-send.rs:14:15
    |
 LL | fn is_send<T: Send>(t: T) { }
    |               ^^^^ required by this bound in `is_send`
diff --git a/tests/ui/async-await/issue-64130-3-other.drop_tracking.stderr b/tests/ui/async-await/issue-64130-3-other.drop_tracking.stderr
new file mode 100644
index 00000000000..d65aae8cc3f
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-3-other.drop_tracking.stderr
@@ -0,0 +1,27 @@
+error[E0277]: the trait bound `Foo: Qux` is not satisfied in `impl Future<Output = ()>`
+  --> $DIR/issue-64130-3-other.rs:27:12
+   |
+LL | async fn bar() {
+   |                - within this `impl Future<Output = ()>`
+...
+LL |     is_qux(bar());
+   |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`
+   |
+note: future does not implement `Qux` as this value is used across an await
+  --> $DIR/issue-64130-3-other.rs:21:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which does not implement `Qux`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_qux`
+  --> $DIR/issue-64130-3-other.rs:17:14
+   |
+LL | fn is_qux<T: Qux>(t: T) {}
+   |              ^^^ required by this bound in `is_qux`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/issue-64130-3-other.drop_tracking_mir.stderr b/tests/ui/async-await/issue-64130-3-other.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..8fed69d9d88
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-3-other.drop_tracking_mir.stderr
@@ -0,0 +1,25 @@
+error[E0277]: the trait bound `Foo: Qux` is not satisfied in `impl Future<Output = ()>`
+  --> $DIR/issue-64130-3-other.rs:27:12
+   |
+LL | async fn bar() {
+   |                - within this `impl Future<Output = ()>`
+...
+LL |     is_qux(bar());
+   |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`
+   |
+note: future does not implement `Qux` as this value is used across an await
+  --> $DIR/issue-64130-3-other.rs:21:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which does not implement `Qux`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+note: required by a bound in `is_qux`
+  --> $DIR/issue-64130-3-other.rs:17:14
+   |
+LL | fn is_qux<T: Qux>(t: T) {}
+   |              ^^^ required by this bound in `is_qux`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/issue-64130-3-other.no_drop_tracking.stderr b/tests/ui/async-await/issue-64130-3-other.no_drop_tracking.stderr
new file mode 100644
index 00000000000..d65aae8cc3f
--- /dev/null
+++ b/tests/ui/async-await/issue-64130-3-other.no_drop_tracking.stderr
@@ -0,0 +1,27 @@
+error[E0277]: the trait bound `Foo: Qux` is not satisfied in `impl Future<Output = ()>`
+  --> $DIR/issue-64130-3-other.rs:27:12
+   |
+LL | async fn bar() {
+   |                - within this `impl Future<Output = ()>`
+...
+LL |     is_qux(bar());
+   |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`
+   |
+note: future does not implement `Qux` as this value is used across an await
+  --> $DIR/issue-64130-3-other.rs:21:10
+   |
+LL |     let x = Box::new(Foo);
+   |         - has type `Box<Foo>` which does not implement `Qux`
+LL |     baz().await;
+   |          ^^^^^^ await occurs here, with `x` maybe used later
+LL | }
+   | - `x` is later dropped here
+note: required by a bound in `is_qux`
+  --> $DIR/issue-64130-3-other.rs:17:14
+   |
+LL | fn is_qux<T: Qux>(t: T) {}
+   |              ^^^ required by this bound in `is_qux`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/issue-64130-3-other.rs b/tests/ui/async-await/issue-64130-3-other.rs
index 630fb2c41cd..92d3b7c81fb 100644
--- a/tests/ui/async-await/issue-64130-3-other.rs
+++ b/tests/ui/async-await/issue-64130-3-other.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(auto_traits)]
 #![feature(negative_impls)]
 // edition:2018
@@ -14,7 +17,7 @@ impl !Qux for Foo {}
 fn is_qux<T: Qux>(t: T) {}
 
 async fn bar() {
-    let x = Foo;
+    let x = Box::new(Foo);
     baz().await;
 }
 
diff --git a/tests/ui/async-await/issue-64130-3-other.stderr b/tests/ui/async-await/issue-64130-3-other.stderr
index 17867a6a3f6..cb36a3811b2 100644
--- a/tests/ui/async-await/issue-64130-3-other.stderr
+++ b/tests/ui/async-await/issue-64130-3-other.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `Foo: Qux` is not satisfied in `impl Future<Output = ()>`
-  --> $DIR/issue-64130-3-other.rs:24:12
+  --> $DIR/issue-64130-3-other.rs:27:12
    |
 LL | async fn bar() {
    |                - within this `impl Future<Output = ()>`
@@ -8,7 +8,7 @@ LL |     is_qux(bar());
    |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`
    |
 note: future does not implement `Qux` as this value is used across an await
-  --> $DIR/issue-64130-3-other.rs:18:10
+  --> $DIR/issue-64130-3-other.rs:21:10
    |
 LL |     let x = Foo;
    |         - has type `Foo` which does not implement `Qux`
@@ -17,7 +17,7 @@ LL |     baz().await;
 LL | }
    | - `x` is later dropped here
 note: required by a bound in `is_qux`
-  --> $DIR/issue-64130-3-other.rs:14:14
+  --> $DIR/issue-64130-3-other.rs:17:14
    |
 LL | fn is_qux<T: Qux>(t: T) {}
    |              ^^^ required by this bound in `is_qux`
diff --git a/tests/ui/async-await/issue-64130-4-async-move.drop-tracking.stderr b/tests/ui/async-await/issue-64130-4-async-move.drop-tracking.stderr
index f609e36362c..884619f4dd6 100644
--- a/tests/ui/async-await/issue-64130-4-async-move.drop-tracking.stderr
+++ b/tests/ui/async-await/issue-64130-4-async-move.drop-tracking.stderr
@@ -1,12 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-64130-4-async-move.rs:19:17
+  --> $DIR/issue-64130-4-async-move.rs:20:17
    |
 LL | pub fn foo() -> impl Future + Send {
    |                 ^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `(dyn Any + Send + 'static)`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/issue-64130-4-async-move.rs:25:31
+  --> $DIR/issue-64130-4-async-move.rs:27:31
    |
 LL |         match client.status() {
    |               ------ has type `&Client` which is not `Send`
@@ -17,7 +17,7 @@ LL |                 let _x = get().await;
 LL |     }
    |     - `client` is later dropped here
 help: consider moving this into a `let` binding to create a shorter lived borrow
-  --> $DIR/issue-64130-4-async-move.rs:23:15
+  --> $DIR/issue-64130-4-async-move.rs:25:15
    |
 LL |         match client.status() {
    |               ^^^^^^^^^^^^^^^
diff --git a/tests/ui/async-await/issue-64130-4-async-move.no_drop_tracking.stderr b/tests/ui/async-await/issue-64130-4-async-move.no_drop_tracking.stderr
index f609e36362c..0bc7cb2f2ac 100644
--- a/tests/ui/async-await/issue-64130-4-async-move.no_drop_tracking.stderr
+++ b/tests/ui/async-await/issue-64130-4-async-move.no_drop_tracking.stderr
@@ -1,12 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-64130-4-async-move.rs:19:17
+  --> $DIR/issue-64130-4-async-move.rs:21:17
    |
 LL | pub fn foo() -> impl Future + Send {
    |                 ^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `(dyn Any + Send + 'static)`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/issue-64130-4-async-move.rs:25:31
+  --> $DIR/issue-64130-4-async-move.rs:27:31
    |
 LL |         match client.status() {
    |               ------ has type `&Client` which is not `Send`
@@ -17,7 +17,7 @@ LL |                 let _x = get().await;
 LL |     }
    |     - `client` is later dropped here
 help: consider moving this into a `let` binding to create a shorter lived borrow
-  --> $DIR/issue-64130-4-async-move.rs:23:15
+  --> $DIR/issue-64130-4-async-move.rs:25:15
    |
 LL |         match client.status() {
    |               ^^^^^^^^^^^^^^^
diff --git a/tests/ui/async-await/issue-64130-4-async-move.rs b/tests/ui/async-await/issue-64130-4-async-move.rs
index a38428fc00f..bcb297aaa02 100644
--- a/tests/ui/async-await/issue-64130-4-async-move.rs
+++ b/tests/ui/async-await/issue-64130-4-async-move.rs
@@ -1,8 +1,10 @@
 // edition:2018
-// revisions: no_drop_tracking drop_tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// [drop_tracking_mir] check-pass
 // [drop_tracking] check-pass
-// [drop_tracking] compile-flags: -Zdrop-tracking=yes
-// [no_drop_tracking] compile-flags: -Zdrop-tracking=no
+
 use std::any::Any;
 use std::future::Future;
 
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking.stderr b/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking.stderr
new file mode 100644
index 00000000000..fc8bcc8ae79
--- /dev/null
+++ b/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking.stderr
@@ -0,0 +1,30 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-67252-unnamed-future.rs:21:11
+   |
+LL |       spawn(async {
+   |  ___________^
+LL | |         let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+LL | |         AFuture.await;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ future created by async block is not `Send`
+   |
+   = help: within `[async block@$DIR/issue-67252-unnamed-future.rs:21:11: 25:6]`, the trait `Send` is not implemented for `*mut ()`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-67252-unnamed-future.rs:23:16
+   |
+LL |         let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+   |             - has type `*mut ()` which is not `Send`
+LL |         AFuture.await;
+   |                ^^^^^^ await occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `spawn`
+  --> $DIR/issue-67252-unnamed-future.rs:9:13
+   |
+LL | fn spawn<T: Send>(_: T) {}
+   |             ^^^^ required by this bound in `spawn`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking_mir.stderr b/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..a3ef7add116
--- /dev/null
+++ b/tests/ui/async-await/issue-67252-unnamed-future.drop_tracking_mir.stderr
@@ -0,0 +1,22 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-67252-unnamed-future.rs:21:5
+   |
+LL |     spawn(async {
+   |     ^^^^^ future created by async block is not `Send`
+   |
+   = help: within `[async block@$DIR/issue-67252-unnamed-future.rs:21:11: 25:6]`, the trait `Send` is not implemented for `*mut ()`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-67252-unnamed-future.rs:23:16
+   |
+LL |         let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+   |             - has type `*mut ()` which is not `Send`
+LL |         AFuture.await;
+   |                ^^^^^^ await occurs here, with `a` maybe used later
+note: required by a bound in `spawn`
+  --> $DIR/issue-67252-unnamed-future.rs:9:13
+   |
+LL | fn spawn<T: Send>(_: T) {}
+   |             ^^^^ required by this bound in `spawn`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.no_drop_tracking.stderr b/tests/ui/async-await/issue-67252-unnamed-future.no_drop_tracking.stderr
new file mode 100644
index 00000000000..fc8bcc8ae79
--- /dev/null
+++ b/tests/ui/async-await/issue-67252-unnamed-future.no_drop_tracking.stderr
@@ -0,0 +1,30 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-67252-unnamed-future.rs:21:11
+   |
+LL |       spawn(async {
+   |  ___________^
+LL | |         let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+LL | |         AFuture.await;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ future created by async block is not `Send`
+   |
+   = help: within `[async block@$DIR/issue-67252-unnamed-future.rs:21:11: 25:6]`, the trait `Send` is not implemented for `*mut ()`
+note: future is not `Send` as this value is used across an await
+  --> $DIR/issue-67252-unnamed-future.rs:23:16
+   |
+LL |         let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+   |             - has type `*mut ()` which is not `Send`
+LL |         AFuture.await;
+   |                ^^^^^^ await occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `spawn`
+  --> $DIR/issue-67252-unnamed-future.rs:9:13
+   |
+LL | fn spawn<T: Send>(_: T) {}
+   |             ^^^^ required by this bound in `spawn`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.rs b/tests/ui/async-await/issue-67252-unnamed-future.rs
index 1a7ff613341..bb9ad77cef3 100644
--- a/tests/ui/async-await/issue-67252-unnamed-future.rs
+++ b/tests/ui/async-await/issue-67252-unnamed-future.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 use std::future::Future;
 use std::pin::Pin;
@@ -16,8 +19,9 @@ impl Future for AFuture{
 
 async fn foo() {
     spawn(async { //~ ERROR future cannot be sent between threads safely
-        let _a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+        let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
         AFuture.await;
+        drop(a);
     });
 }
 
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.stderr b/tests/ui/async-await/issue-67252-unnamed-future.stderr
deleted file mode 100644
index fcba4410ba9..00000000000
--- a/tests/ui/async-await/issue-67252-unnamed-future.stderr
+++ /dev/null
@@ -1,28 +0,0 @@
-error: future cannot be sent between threads safely
-  --> $DIR/issue-67252-unnamed-future.rs:18:11
-   |
-LL |       spawn(async {
-   |  ___________^
-LL | |         let _a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
-LL | |         AFuture.await;
-LL | |     });
-   | |_____^ future created by async block is not `Send`
-   |
-   = help: within `[async block@$DIR/issue-67252-unnamed-future.rs:18:11: 21:6]`, the trait `Send` is not implemented for `*mut ()`
-note: future is not `Send` as this value is used across an await
-  --> $DIR/issue-67252-unnamed-future.rs:20:16
-   |
-LL |         let _a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
-   |             -- has type `*mut ()` which is not `Send`
-LL |         AFuture.await;
-   |                ^^^^^^ await occurs here, with `_a` maybe used later
-LL |     });
-   |     - `_a` is later dropped here
-note: required by a bound in `spawn`
-  --> $DIR/issue-67252-unnamed-future.rs:6:13
-   |
-LL | fn spawn<T: Send>(_: T) {}
-   |             ^^^^ required by this bound in `spawn`
-
-error: aborting due to previous error
-
diff --git a/tests/ui/async-await/issue-68112.drop_tracking.stderr b/tests/ui/async-await/issue-68112.drop_tracking.stderr
index f2802698fd5..bd648de3067 100644
--- a/tests/ui/async-await/issue-68112.drop_tracking.stderr
+++ b/tests/ui/async-await/issue-68112.drop_tracking.stderr
@@ -5,6 +5,7 @@ LL |     require_send(send_fut);
    |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:34:17
    |
@@ -23,6 +24,7 @@ LL |     require_send(send_fut);
    |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:43:17
    |
@@ -43,6 +45,7 @@ LL |     require_send(send_fut);
    |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this `async fn` body
   --> $DIR/issue-68112.rs:50:31
diff --git a/tests/ui/async-await/issue-68112.drop_tracking_mir.stderr b/tests/ui/async-await/issue-68112.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..7a9242cbaf5
--- /dev/null
+++ b/tests/ui/async-await/issue-68112.drop_tracking_mir.stderr
@@ -0,0 +1,80 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-68112.rs:37:5
+   |
+LL |     require_send(send_fut);
+   |     ^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: future is not `Send` as it awaits another future which is not `Send`
+  --> $DIR/issue-68112.rs:34:17
+   |
+LL |         let _ = non_send_fut.await;
+   |                 ^^^^^^^^^^^^ await occurs here on type `impl Future<Output = Arc<RefCell<i32>>>`, which is not `Send`
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:14:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: future cannot be sent between threads safely
+  --> $DIR/issue-68112.rs:46:5
+   |
+LL |     require_send(send_fut);
+   |     ^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: future is not `Send` as it awaits another future which is not `Send`
+  --> $DIR/issue-68112.rs:43:17
+   |
+LL |         let _ = make_non_send_future1().await;
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^ await occurs here on type `impl Future<Output = Arc<RefCell<i32>>>`, which is not `Send`
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:14:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error[E0277]: `RefCell<i32>` cannot be shared between threads safely
+  --> $DIR/issue-68112.rs:65:5
+   |
+LL |     require_send(send_fut);
+   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+   = note: required for `Arc<RefCell<i32>>` to implement `Send`
+note: required because it's used within this `async fn` body
+  --> $DIR/issue-68112.rs:50:31
+   |
+LL |   async fn ready2<T>(t: T) -> T {
+   |  _______________________________^
+LL | |     t
+LL | | }
+   | |_^
+note: required because it appears within the type `impl Future<Output = Arc<RefCell<i32>>>`
+  --> $DIR/issue-68112.rs:53:31
+   |
+LL | fn make_non_send_future2() -> impl Future<Output = Arc<RefCell<i32>>> {
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: required because it captures the following types: `impl Future<Output = Arc<RefCell<i32>>>`, `Ready<i32>`
+note: required because it's used within this `async` block
+  --> $DIR/issue-68112.rs:60:20
+   |
+LL |       let send_fut = async {
+   |  ____________________^
+LL | |         let non_send_fut = make_non_send_future2();
+LL | |         let _ = non_send_fut.await;
+LL | |         ready(0).await;
+LL | |     };
+   | |_____^
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:14:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/issue-68112.no_drop_tracking.stderr b/tests/ui/async-await/issue-68112.no_drop_tracking.stderr
index 38eb85b302f..35b7341f63a 100644
--- a/tests/ui/async-await/issue-68112.no_drop_tracking.stderr
+++ b/tests/ui/async-await/issue-68112.no_drop_tracking.stderr
@@ -5,6 +5,7 @@ LL |     require_send(send_fut);
    |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:34:17
    |
@@ -23,6 +24,7 @@ LL |     require_send(send_fut);
    |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:43:17
    |
@@ -43,6 +45,7 @@ LL |     require_send(send_fut);
    |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this `async fn` body
   --> $DIR/issue-68112.rs:50:31
diff --git a/tests/ui/async-await/issue-68112.rs b/tests/ui/async-await/issue-68112.rs
index 9c705137a10..19119ae0fc1 100644
--- a/tests/ui/async-await/issue-68112.rs
+++ b/tests/ui/async-await/issue-68112.rs
@@ -1,7 +1,7 @@
 // edition:2018
-// revisions: no_drop_tracking drop_tracking
-// [drop_tracking] compile-flags: -Zdrop-tracking=yes
-// [no_drop_tracking] compile-flags: -Zdrop-tracking=no
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 
 use std::{
     cell::RefCell,
@@ -14,7 +14,7 @@ use std::{
 fn require_send(_: impl Send) {}
 
 struct Ready<T>(Option<T>);
-impl<T> Future for Ready<T> {
+impl<T: Unpin> Future for Ready<T> {
     type Output = T;
     fn poll(mut self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<T> {
         Poll::Ready(self.0.take().unwrap())
diff --git a/tests/ui/async-await/issue-70818.drop_tracking.stderr b/tests/ui/async-await/issue-70818.drop_tracking.stderr
new file mode 100644
index 00000000000..ab0698c3ec2
--- /dev/null
+++ b/tests/ui/async-await/issue-70818.drop_tracking.stderr
@@ -0,0 +1,18 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-70818.rs:7:38
+   |
+LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+note: captured value is not `Send`
+  --> $DIR/issue-70818.rs:9:18
+   |
+LL |     async { (ty, ty1) }
+   |                  ^^^ has type `U` which is not `Send`
+help: consider restricting type parameter `U`
+   |
+LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                  +++++++++++++++++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-70818.drop_tracking_mir.stderr b/tests/ui/async-await/issue-70818.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..ab0698c3ec2
--- /dev/null
+++ b/tests/ui/async-await/issue-70818.drop_tracking_mir.stderr
@@ -0,0 +1,18 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-70818.rs:7:38
+   |
+LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+note: captured value is not `Send`
+  --> $DIR/issue-70818.rs:9:18
+   |
+LL |     async { (ty, ty1) }
+   |                  ^^^ has type `U` which is not `Send`
+help: consider restricting type parameter `U`
+   |
+LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                  +++++++++++++++++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-70818.no_drop_tracking.stderr b/tests/ui/async-await/issue-70818.no_drop_tracking.stderr
new file mode 100644
index 00000000000..ab0698c3ec2
--- /dev/null
+++ b/tests/ui/async-await/issue-70818.no_drop_tracking.stderr
@@ -0,0 +1,18 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-70818.rs:7:38
+   |
+LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+note: captured value is not `Send`
+  --> $DIR/issue-70818.rs:9:18
+   |
+LL |     async { (ty, ty1) }
+   |                  ^^^ has type `U` which is not `Send`
+help: consider restricting type parameter `U`
+   |
+LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                  +++++++++++++++++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-70818.rs b/tests/ui/async-await/issue-70818.rs
index 019c56eb2fa..2941de0f577 100644
--- a/tests/ui/async-await/issue-70818.rs
+++ b/tests/ui/async-await/issue-70818.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 
 use std::future::Future;
diff --git a/tests/ui/async-await/issue-70818.stderr b/tests/ui/async-await/issue-70818.stderr
index 20109d4d116..ab0698c3ec2 100644
--- a/tests/ui/async-await/issue-70818.stderr
+++ b/tests/ui/async-await/issue-70818.stderr
@@ -1,11 +1,11 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-70818.rs:4:38
+  --> $DIR/issue-70818.rs:7:38
    |
 LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
    |
 note: captured value is not `Send`
-  --> $DIR/issue-70818.rs:6:18
+  --> $DIR/issue-70818.rs:9:18
    |
 LL |     async { (ty, ty1) }
    |                  ^^^ has type `U` which is not `Send`
diff --git a/tests/ui/async-await/issue-70935-complex-spans.drop_tracking_mir.stderr b/tests/ui/async-await/issue-70935-complex-spans.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..c636be15a58
--- /dev/null
+++ b/tests/ui/async-await/issue-70935-complex-spans.drop_tracking_mir.stderr
@@ -0,0 +1,34 @@
+error[E0277]: `Sender<i32>` cannot be shared between threads safely
+  --> $DIR/issue-70935-complex-spans.rs:13:45
+   |
+LL | fn foo(tx: std::sync::mpsc::Sender<i32>) -> impl Future + Send {
+   |                                             ^^^^^^^^^^^^^^^^^^ `Sender<i32>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `Sender<i32>`
+   = note: required for `&Sender<i32>` to implement `Send`
+note: required because it's used within this closure
+  --> $DIR/issue-70935-complex-spans.rs:17:13
+   |
+LL |         baz(|| async{
+   |             ^^
+note: required because it's used within this `async fn` body
+  --> $DIR/issue-70935-complex-spans.rs:10:67
+   |
+LL |   async fn baz<T>(_c: impl FnMut() -> T) where T: Future<Output=()> {
+   |  ___________________________________________________________________^
+LL | | }
+   | |_^
+   = note: required because it captures the following types: `impl Future<Output = ()>`
+note: required because it's used within this `async` block
+  --> $DIR/issue-70935-complex-spans.rs:16:5
+   |
+LL | /     async move {
+LL | |         baz(|| async{
+LL | |             foo(tx.clone());
+LL | |         }).await;
+LL | |     }
+   | |_____^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/issue-70935-complex-spans.rs b/tests/ui/async-await/issue-70935-complex-spans.rs
index b6d17f93a66..78625bd393d 100644
--- a/tests/ui/async-await/issue-70935-complex-spans.rs
+++ b/tests/ui/async-await/issue-70935-complex-spans.rs
@@ -1,7 +1,7 @@
 // edition:2018
-// revisions: no_drop_tracking drop_tracking
-// [no_drop_tracking]compile-flags:-Zdrop-tracking=no
-// [drop_tracking]compile-flags:-Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // #70935: Check if we do not emit snippet
 // with newlines which lead complex diagnostics.
 
@@ -12,7 +12,7 @@ async fn baz<T>(_c: impl FnMut() -> T) where T: Future<Output=()> {
 
 fn foo(tx: std::sync::mpsc::Sender<i32>) -> impl Future + Send {
     //[no_drop_tracking]~^ ERROR future cannot be sent between threads safely
-    //[drop_tracking]~^^ ERROR `Sender<i32>` cannot be shared between threads
+    //[drop_tracking,drop_tracking_mir]~^^ ERROR `Sender<i32>` cannot be shared between threads
     async move {
         baz(|| async{
             foo(tx.clone());
diff --git a/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking.stderr b/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking.stderr
new file mode 100644
index 00000000000..6d19c3beb2f
--- /dev/null
+++ b/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking.stderr
@@ -0,0 +1,11 @@
+error[E0070]: invalid left-hand side of assignment
+  --> $DIR/issue-73741-type-err-drop-tracking.rs:11:7
+   |
+LL |     1 = 2;
+   |     - ^
+   |     |
+   |     cannot assign to this expression
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0070`.
diff --git a/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking_mir.stderr b/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..6d19c3beb2f
--- /dev/null
+++ b/tests/ui/async-await/issue-73741-type-err-drop-tracking.drop_tracking_mir.stderr
@@ -0,0 +1,11 @@
+error[E0070]: invalid left-hand side of assignment
+  --> $DIR/issue-73741-type-err-drop-tracking.rs:11:7
+   |
+LL |     1 = 2;
+   |     - ^
+   |     |
+   |     cannot assign to this expression
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0070`.
diff --git a/tests/ui/async-await/issue-73741-type-err-drop-tracking.no_drop_tracking.stderr b/tests/ui/async-await/issue-73741-type-err-drop-tracking.no_drop_tracking.stderr
new file mode 100644
index 00000000000..6d19c3beb2f
--- /dev/null
+++ b/tests/ui/async-await/issue-73741-type-err-drop-tracking.no_drop_tracking.stderr
@@ -0,0 +1,11 @@
+error[E0070]: invalid left-hand side of assignment
+  --> $DIR/issue-73741-type-err-drop-tracking.rs:11:7
+   |
+LL |     1 = 2;
+   |     - ^
+   |     |
+   |     cannot assign to this expression
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0070`.
diff --git a/tests/ui/async-await/issue-73741-type-err-drop-tracking.rs b/tests/ui/async-await/issue-73741-type-err-drop-tracking.rs
index c3423ad629f..1fa8d69143a 100644
--- a/tests/ui/async-await/issue-73741-type-err-drop-tracking.rs
+++ b/tests/ui/async-await/issue-73741-type-err-drop-tracking.rs
@@ -1,5 +1,8 @@
 // edition:2018
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+//
 // Regression test for issue #73741
 // Ensures that we don't emit spurious errors when
 // a type error ocurrs in an `async fn`
diff --git a/tests/ui/async-await/issue-73741-type-err-drop-tracking.stderr b/tests/ui/async-await/issue-73741-type-err-drop-tracking.stderr
index d4e3b6c3bf4..6d19c3beb2f 100644
--- a/tests/ui/async-await/issue-73741-type-err-drop-tracking.stderr
+++ b/tests/ui/async-await/issue-73741-type-err-drop-tracking.stderr
@@ -1,5 +1,5 @@
 error[E0070]: invalid left-hand side of assignment
-  --> $DIR/issue-73741-type-err-drop-tracking.rs:8:7
+  --> $DIR/issue-73741-type-err-drop-tracking.rs:11:7
    |
 LL |     1 = 2;
    |     - ^
diff --git a/tests/ui/async-await/issue-74072-lifetime-name-annotations.stderr b/tests/ui/async-await/issue-74072-lifetime-name-annotations.stderr
index b96cab9f0f5..628ba1a4818 100644
--- a/tests/ui/async-await/issue-74072-lifetime-name-annotations.stderr
+++ b/tests/ui/async-await/issue-74072-lifetime-name-annotations.stderr
@@ -4,9 +4,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
 LL | pub async fn async_fn(x: &mut i32) -> &i32 {
    |                          - let's call the lifetime of this reference `'1`
 LL |     let y = &*x;
-   |             --- borrow of `*x` occurs here
+   |             --- `*x` is borrowed here
 LL |     *x += 1;
-   |     ^^^^^^^ assignment to borrowed `*x` occurs here
+   |     ^^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |     y
    |     - returning this value requires that `*x` is borrowed for `'1`
 
@@ -14,9 +14,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
   --> $DIR/issue-74072-lifetime-name-annotations.rs:16:9
    |
 LL |         let y = &*x;
-   |                 --- borrow of `*x` occurs here
+   |                 --- `*x` is borrowed here
 LL |         *x += 1;
-   |         ^^^^^^^ assignment to borrowed `*x` occurs here
+   |         ^^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |         y
    |         - returning this value requires that `*x` is borrowed for `'1`
 LL |     })()
@@ -28,9 +28,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
 LL |     (async move || -> &i32 {
    |                       - let's call the lifetime of this reference `'1`
 LL |         let y = &*x;
-   |                 --- borrow of `*x` occurs here
+   |                 --- `*x` is borrowed here
 LL |         *x += 1;
-   |         ^^^^^^^ assignment to borrowed `*x` occurs here
+   |         ^^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |         y
    |         - returning this value requires that `*x` is borrowed for `'1`
 
@@ -38,9 +38,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
   --> $DIR/issue-74072-lifetime-name-annotations.rs:32:9
    |
 LL |         let y = &*x;
-   |                 --- borrow of `*x` occurs here
+   |                 --- `*x` is borrowed here
 LL |         *x += 1;
-   |         ^^^^^^^ assignment to borrowed `*x` occurs here
+   |         ^^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |         y
    |         - returning this value requires that `*x` is borrowed for `'1`
 LL |     }
diff --git a/tests/ui/async-await/issue-75785-confusing-named-region.stderr b/tests/ui/async-await/issue-75785-confusing-named-region.stderr
index 3b731d9c60a..b69033a0eda 100644
--- a/tests/ui/async-await/issue-75785-confusing-named-region.stderr
+++ b/tests/ui/async-await/issue-75785-confusing-named-region.stderr
@@ -4,9 +4,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
 LL | pub async fn async_fn(x: &mut i32) -> (&i32, &i32) {
    |                          - let's call the lifetime of this reference `'1`
 LL |     let y = &*x;
-   |             --- borrow of `*x` occurs here
+   |             --- `*x` is borrowed here
 LL |     *x += 1;
-   |     ^^^^^^^ assignment to borrowed `*x` occurs here
+   |     ^^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |     (&32, y)
    |     -------- returning this value requires that `*x` is borrowed for `'1`
 
diff --git a/tests/ui/async-await/issue-86507.stderr b/tests/ui/async-await/issue-86507.drop_tracking.stderr
index 8c2c06da25c..5c8b7ef1b71 100644
--- a/tests/ui/async-await/issue-86507.stderr
+++ b/tests/ui/async-await/issue-86507.drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-86507.rs:17:13
+  --> $DIR/issue-86507.rs:20:13
    |
 LL | /             Box::pin(
 LL | |                 async move {
@@ -9,11 +9,11 @@ LL | |             )
    | |_____________^ future created by async block is not `Send`
    |
 note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync`
-  --> $DIR/issue-86507.rs:19:29
+  --> $DIR/issue-86507.rs:22:29
    |
 LL |                     let x = x;
    |                             ^ has type `&T` which is not `Send`, because `T` is not `Sync`
-   = note: required for the cast from `[async block@$DIR/issue-86507.rs:18:17: 20:18]` to the object type `dyn Future<Output = ()> + Send`
+   = note: required for the cast from `[async block@$DIR/issue-86507.rs:21:17: 23:18]` to the object type `dyn Future<Output = ()> + Send`
 help: consider further restricting this bound
    |
 LL |     fn bar<'me, 'async_trait, T: Send + std::marker::Sync>(x: &'me T)
diff --git a/tests/ui/async-await/issue-86507.drop_tracking_mir.stderr b/tests/ui/async-await/issue-86507.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..5c8b7ef1b71
--- /dev/null
+++ b/tests/ui/async-await/issue-86507.drop_tracking_mir.stderr
@@ -0,0 +1,23 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-86507.rs:20:13
+   |
+LL | /             Box::pin(
+LL | |                 async move {
+LL | |                     let x = x;
+LL | |                 }
+LL | |             )
+   | |_____________^ future created by async block is not `Send`
+   |
+note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync`
+  --> $DIR/issue-86507.rs:22:29
+   |
+LL |                     let x = x;
+   |                             ^ has type `&T` which is not `Send`, because `T` is not `Sync`
+   = note: required for the cast from `[async block@$DIR/issue-86507.rs:21:17: 23:18]` to the object type `dyn Future<Output = ()> + Send`
+help: consider further restricting this bound
+   |
+LL |     fn bar<'me, 'async_trait, T: Send + std::marker::Sync>(x: &'me T)
+   |                                       +++++++++++++++++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-86507.no_drop_tracking.stderr b/tests/ui/async-await/issue-86507.no_drop_tracking.stderr
new file mode 100644
index 00000000000..5c8b7ef1b71
--- /dev/null
+++ b/tests/ui/async-await/issue-86507.no_drop_tracking.stderr
@@ -0,0 +1,23 @@
+error: future cannot be sent between threads safely
+  --> $DIR/issue-86507.rs:20:13
+   |
+LL | /             Box::pin(
+LL | |                 async move {
+LL | |                     let x = x;
+LL | |                 }
+LL | |             )
+   | |_____________^ future created by async block is not `Send`
+   |
+note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync`
+  --> $DIR/issue-86507.rs:22:29
+   |
+LL |                     let x = x;
+   |                             ^ has type `&T` which is not `Send`, because `T` is not `Sync`
+   = note: required for the cast from `[async block@$DIR/issue-86507.rs:21:17: 23:18]` to the object type `dyn Future<Output = ()> + Send`
+help: consider further restricting this bound
+   |
+LL |     fn bar<'me, 'async_trait, T: Send + std::marker::Sync>(x: &'me T)
+   |                                       +++++++++++++++++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/issue-86507.rs b/tests/ui/async-await/issue-86507.rs
index 317f0317664..63c298dbe3d 100644
--- a/tests/ui/async-await/issue-86507.rs
+++ b/tests/ui/async-await/issue-86507.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 
 use ::core::pin::Pin;
diff --git a/tests/ui/async-await/issue-93648.rs b/tests/ui/async-await/issue-93648.rs
index 4ce3ac1e874..ec2249ca592 100644
--- a/tests/ui/async-await/issue-93648.rs
+++ b/tests/ui/async-await/issue-93648.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2021
 // build-pass
-// compile-flags: -Zdrop-tracking
 
 fn main() {
     let _ = async {
diff --git a/tests/ui/async-await/issues/auxiliary/issue_67893.rs b/tests/ui/async-await/issues/auxiliary/issue_67893.rs
index 387966a5064..d5394469806 100644
--- a/tests/ui/async-await/issues/auxiliary/issue_67893.rs
+++ b/tests/ui/async-await/issues/auxiliary/issue_67893.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 
 use std::sync::{Arc, Mutex};
diff --git a/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.no_drop_tracking.stderr b/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.no_drop_tracking.stderr
index 1033fa6cc8b..8745bdd973b 100644
--- a/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.no_drop_tracking.stderr
+++ b/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.no_drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:16:17
+  --> $DIR/issue-65436-raw-ptr-not-send.rs:17:17
    |
 LL |       assert_send(async {
    |  _________________^
@@ -8,9 +8,9 @@ LL | |         bar(Foo(std::ptr::null())).await;
 LL | |     })
    | |_____^ future created by async block is not `Send`
    |
-   = help: within `[async block@$DIR/issue-65436-raw-ptr-not-send.rs:16:17: 19:6]`, the trait `Send` is not implemented for `*const u8`
+   = help: within `[async block@$DIR/issue-65436-raw-ptr-not-send.rs:17:17: 20:6]`, the trait `Send` is not implemented for `*const u8`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:18:35
+  --> $DIR/issue-65436-raw-ptr-not-send.rs:19:35
    |
 LL |         bar(Foo(std::ptr::null())).await;
    |                 ----------------  ^^^^^^- `std::ptr::null()` is later dropped here
@@ -18,12 +18,12 @@ LL |         bar(Foo(std::ptr::null())).await;
    |                 |                 await occurs here, with `std::ptr::null()` maybe used later
    |                 has type `*const u8` which is not `Send`
 help: consider moving this into a `let` binding to create a shorter lived borrow
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:18:13
+  --> $DIR/issue-65436-raw-ptr-not-send.rs:19:13
    |
 LL |         bar(Foo(std::ptr::null())).await;
    |             ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `assert_send`
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:13:19
+  --> $DIR/issue-65436-raw-ptr-not-send.rs:14:19
    |
 LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
diff --git a/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.rs b/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.rs
index 91edbc10dc0..d7ef929517c 100644
--- a/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.rs
+++ b/tests/ui/async-await/issues/issue-65436-raw-ptr-not-send.rs
@@ -1,8 +1,9 @@
 // edition:2018
-// revisions: no_drop_tracking drop_tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // [drop_tracking] check-pass
-// [drop_tracking] compile-flags: -Zdrop-tracking=yes
-// [no_drop_tracking] compile-flags: -Zdrop-tracking=no
+// [drop_tracking_mir] check-pass
 
 struct Foo(*const u8);
 
diff --git a/tests/ui/async-await/issues/issue-67611-static-mut-refs.rs b/tests/ui/async-await/issues/issue-67611-static-mut-refs.rs
index dda4a151dd2..c4f8f607d25 100644
--- a/tests/ui/async-await/issues/issue-67611-static-mut-refs.rs
+++ b/tests/ui/async-await/issues/issue-67611-static-mut-refs.rs
@@ -1,6 +1,10 @@
 // build-pass
 // edition:2018
 
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 static mut A: [i32; 5] = [1, 2, 3, 4, 5];
 
 fn is_send_sync<T: Send + Sync>(_: T) {}
diff --git a/tests/ui/async-await/issues/issue-67893.stderr b/tests/ui/async-await/issues/issue-67893.stderr
index 2ce68a78291..ce9424c8b25 100644
--- a/tests/ui/async-await/issues/issue-67893.stderr
+++ b/tests/ui/async-await/issues/issue-67893.stderr
@@ -6,7 +6,7 @@ LL |     g(issue_67893::run())
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, ()>`
 note: future is not `Send` as this value is used across an await
-  --> $DIR/auxiliary/issue_67893.rs:9:26
+  --> $DIR/auxiliary/issue_67893.rs:12:26
    |
 LL |     f(*x.lock().unwrap()).await;
    |        ----------------- ^^^^^^- `x.lock().unwrap()` is later dropped here
diff --git a/tests/ui/async-await/multiple-lifetimes/ret-ref.stderr b/tests/ui/async-await/multiple-lifetimes/ret-ref.stderr
index d86e84033b8..a599ac1d92f 100644
--- a/tests/ui/async-await/multiple-lifetimes/ret-ref.stderr
+++ b/tests/ui/async-await/multiple-lifetimes/ret-ref.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `a` because it is borrowed
   --> $DIR/ret-ref.rs:16:5
    |
 LL |     let future = multiple_named_lifetimes(&a, &b);
-   |                                           -- borrow of `a` occurs here
+   |                                           -- `a` is borrowed here
 LL |     a += 1;
-   |     ^^^^^^ assignment to borrowed `a` occurs here
+   |     ^^^^^^ `a` is assigned to here but it was already borrowed
 LL |     b += 1;
 LL |     let p = future.await;
    |             ------ borrow later used here
@@ -13,10 +13,10 @@ error[E0506]: cannot assign to `b` because it is borrowed
   --> $DIR/ret-ref.rs:17:5
    |
 LL |     let future = multiple_named_lifetimes(&a, &b);
-   |                                               -- borrow of `b` occurs here
+   |                                               -- `b` is borrowed here
 LL |     a += 1;
 LL |     b += 1;
-   |     ^^^^^^ assignment to borrowed `b` occurs here
+   |     ^^^^^^ `b` is assigned to here but it was already borrowed
 LL |     let p = future.await;
    |             ------ borrow later used here
 
@@ -24,10 +24,10 @@ error[E0506]: cannot assign to `a` because it is borrowed
   --> $DIR/ret-ref.rs:28:5
    |
 LL |     let future = multiple_named_lifetimes(&a, &b);
-   |                                           -- borrow of `a` occurs here
+   |                                           -- `a` is borrowed here
 LL |     let p = future.await;
 LL |     a += 1;
-   |     ^^^^^^ assignment to borrowed `a` occurs here
+   |     ^^^^^^ `a` is assigned to here but it was already borrowed
 LL |     b += 1;
 LL |     drop(p);
    |          - borrow later used here
diff --git a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking.stderr b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking.stderr
new file mode 100644
index 00000000000..8a7317bb95a
--- /dev/null
+++ b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking.stderr
@@ -0,0 +1,21 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18
+   |
+LL | async fn rec_1() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:13:18
+   |
+LL | async fn rec_2() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking_mir.stderr b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..8a7317bb95a
--- /dev/null
+++ b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.drop_tracking_mir.stderr
@@ -0,0 +1,21 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18
+   |
+LL | async fn rec_1() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:13:18
+   |
+LL | async fn rec_2() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.no_drop_tracking.stderr b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.no_drop_tracking.stderr
new file mode 100644
index 00000000000..8a7317bb95a
--- /dev/null
+++ b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.no_drop_tracking.stderr
@@ -0,0 +1,21 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18
+   |
+LL | async fn rec_1() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:13:18
+   |
+LL | async fn rec_2() {
+   |                  ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.rs b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.rs
index bb2a61f03ce..a241f30e73e 100644
--- a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.rs
+++ b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.rs
@@ -1,3 +1,7 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 // edition:2018
 // Test that impl trait does not allow creating recursive types that are
 // otherwise forbidden when using `async` and `await`.
diff --git a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.stderr b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.stderr
index f789ad2a05c..8a7317bb95a 100644
--- a/tests/ui/async-await/mutually-recursive-async-impl-trait-type.stderr
+++ b/tests/ui/async-await/mutually-recursive-async-impl-trait-type.stderr
@@ -1,5 +1,5 @@
 error[E0733]: recursion in an `async fn` requires boxing
-  --> $DIR/mutually-recursive-async-impl-trait-type.rs:5:18
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18
    |
 LL | async fn rec_1() {
    |                  ^ recursive `async fn`
@@ -8,7 +8,7 @@ LL | async fn rec_1() {
    = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
 
 error[E0733]: recursion in an `async fn` requires boxing
-  --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18
+  --> $DIR/mutually-recursive-async-impl-trait-type.rs:13:18
    |
 LL | async fn rec_2() {
    |                  ^ recursive `async fn`
diff --git a/tests/ui/async-await/non-trivial-drop.rs b/tests/ui/async-await/non-trivial-drop.rs
index a3167215dc3..d4df9d439c5 100644
--- a/tests/ui/async-await/non-trivial-drop.rs
+++ b/tests/ui/async-await/non-trivial-drop.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // build-pass
 // edition:2018
-// compile-flags: -Zdrop-tracking=y
 
 #![feature(generators)]
 
diff --git a/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking.stderr b/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking.stderr
new file mode 100644
index 00000000000..7e63a8da552
--- /dev/null
+++ b/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/recursive-async-impl-trait-type.rs:8:40
+   |
+LL | async fn recursive_async_function() -> () {
+   |                                        ^^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking_mir.stderr b/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..7e63a8da552
--- /dev/null
+++ b/tests/ui/async-await/recursive-async-impl-trait-type.drop_tracking_mir.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/recursive-async-impl-trait-type.rs:8:40
+   |
+LL | async fn recursive_async_function() -> () {
+   |                                        ^^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/recursive-async-impl-trait-type.no_drop_tracking.stderr b/tests/ui/async-await/recursive-async-impl-trait-type.no_drop_tracking.stderr
new file mode 100644
index 00000000000..7e63a8da552
--- /dev/null
+++ b/tests/ui/async-await/recursive-async-impl-trait-type.no_drop_tracking.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/recursive-async-impl-trait-type.rs:8:40
+   |
+LL | async fn recursive_async_function() -> () {
+   |                                        ^^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/recursive-async-impl-trait-type.rs b/tests/ui/async-await/recursive-async-impl-trait-type.rs
index edc4cb8ac5d..60b34d3a174 100644
--- a/tests/ui/async-await/recursive-async-impl-trait-type.rs
+++ b/tests/ui/async-await/recursive-async-impl-trait-type.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 // Test that impl trait does not allow creating recursive types that are
 // otherwise forbidden when using `async` and `await`.
diff --git a/tests/ui/async-await/recursive-async-impl-trait-type.stderr b/tests/ui/async-await/recursive-async-impl-trait-type.stderr
index 63f64f44557..7e63a8da552 100644
--- a/tests/ui/async-await/recursive-async-impl-trait-type.stderr
+++ b/tests/ui/async-await/recursive-async-impl-trait-type.stderr
@@ -1,5 +1,5 @@
 error[E0733]: recursion in an `async fn` requires boxing
-  --> $DIR/recursive-async-impl-trait-type.rs:5:40
+  --> $DIR/recursive-async-impl-trait-type.rs:8:40
    |
 LL | async fn recursive_async_function() -> () {
    |                                        ^^ recursive `async fn`
diff --git a/tests/ui/async-await/send-bound-async-closure.rs b/tests/ui/async-await/send-bound-async-closure.rs
new file mode 100644
index 00000000000..4e9e7309be0
--- /dev/null
+++ b/tests/ui/async-await/send-bound-async-closure.rs
@@ -0,0 +1,37 @@
+// edition: 2021
+// check-pass
+
+// This test verifies that we do not create a query cycle when typechecking has several inference
+// variables that point to the same generator interior type.
+
+use std::future::Future;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+type ChannelTask = Pin<Box<dyn Future<Output = ()> + Send>>;
+
+pub fn register_message_type() -> ChannelTask {
+    Box::pin(async move {
+        let f = |__cx: &mut Context<'_>| Poll::<()>::Pending;
+        PollFn { f }.await
+    })
+}
+
+struct PollFn<F> {
+    f: F,
+}
+
+impl<F> Unpin for PollFn<F> {}
+
+impl<T, F> Future for PollFn<F>
+where
+    F: FnMut(&mut Context<'_>) -> Poll<T>,
+{
+    type Output = T;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
+        (&mut self.f)(cx)
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/async-await/unresolved_type_param.drop_tracking.stderr b/tests/ui/async-await/unresolved_type_param.drop_tracking.stderr
new file mode 100644
index 00000000000..912e2b34c05
--- /dev/null
+++ b/tests/ui/async-await/unresolved_type_param.drop_tracking.stderr
@@ -0,0 +1,39 @@
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0698`.
diff --git a/tests/ui/async-await/unresolved_type_param.drop_tracking_mir.stderr b/tests/ui/async-await/unresolved_type_param.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..95c79946831
--- /dev/null
+++ b/tests/ui/async-await/unresolved_type_param.drop_tracking_mir.stderr
@@ -0,0 +1,14 @@
+error[E0282]: type annotations needed
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type of the type parameter `T` declared on the function `bar`
+   |
+help: consider specifying the generic argument
+   |
+LL |     bar::<T>().await;
+   |        +++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.
diff --git a/tests/ui/async-await/unresolved_type_param.no_drop_tracking.stderr b/tests/ui/async-await/unresolved_type_param.no_drop_tracking.stderr
new file mode 100644
index 00000000000..16d618caa57
--- /dev/null
+++ b/tests/ui/async-await/unresolved_type_param.no_drop_tracking.stderr
@@ -0,0 +1,63 @@
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error[E0698]: type inside `async fn` body must be known in this context
+  --> $DIR/unresolved_type_param.rs:12:5
+   |
+LL |     bar().await;
+   |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
+   |
+note: the type is part of the `async fn` body because of this `await`
+  --> $DIR/unresolved_type_param.rs:12:10
+   |
+LL |     bar().await;
+   |          ^^^^^^
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0698`.
diff --git a/tests/ui/async-await/unresolved_type_param.rs b/tests/ui/async-await/unresolved_type_param.rs
index 6d6d8061491..ca0a92b9434 100644
--- a/tests/ui/async-await/unresolved_type_param.rs
+++ b/tests/ui/async-await/unresolved_type_param.rs
@@ -1,24 +1,36 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // Provoke an unresolved type error (T).
 // Error message should pinpoint the type parameter T as needing to be bound
 // (rather than give a general error message)
 // edition:2018
-// compile-flags: -Zdrop-tracking
 
 async fn bar<T>() -> () {}
 
 async fn foo() {
     bar().await;
-    //~^ ERROR type inside `async fn` body must be known in this context
-    //~| ERROR type inside `async fn` body must be known in this context
-    //~| ERROR type inside `async fn` body must be known in this context
-    //~| NOTE cannot infer type for type parameter `T`
-    //~| NOTE cannot infer type for type parameter `T`
-    //~| NOTE cannot infer type for type parameter `T`
-    //~| NOTE the type is part of the `async fn` body because of this `await`
-    //~| NOTE the type is part of the `async fn` body because of this `await`
-    //~| NOTE the type is part of the `async fn` body because of this `await`
-    //~| NOTE in this expansion of desugaring of `await`
-    //~| NOTE in this expansion of desugaring of `await`
-    //~| NOTE in this expansion of desugaring of `await`
+    //[drop_tracking_mir]~^ ERROR type annotations needed
+    //[drop_tracking_mir]~| NOTE cannot infer type of the type parameter `T`
+    //[no_drop_tracking,drop_tracking]~^^^ ERROR type inside `async fn` body must be known in this context
+    //[no_drop_tracking,drop_tracking]~| ERROR type inside `async fn` body must be known in this context
+    //[no_drop_tracking,drop_tracking]~| ERROR type inside `async fn` body must be known in this context
+    //[no_drop_tracking,drop_tracking]~| NOTE cannot infer type for type parameter `T`
+    //[no_drop_tracking,drop_tracking]~| NOTE cannot infer type for type parameter `T`
+    //[no_drop_tracking,drop_tracking]~| NOTE cannot infer type for type parameter `T`
+    //[no_drop_tracking,drop_tracking]~| NOTE the type is part of the `async fn` body because of this `await`
+    //[no_drop_tracking,drop_tracking]~| NOTE the type is part of the `async fn` body because of this `await`
+    //[no_drop_tracking,drop_tracking]~| NOTE the type is part of the `async fn` body because of this `await`
+    //[no_drop_tracking,drop_tracking]~| NOTE in this expansion of desugaring of `await`
+    //[no_drop_tracking,drop_tracking]~| NOTE in this expansion of desugaring of `await`
+    //[no_drop_tracking,drop_tracking]~| NOTE in this expansion of desugaring of `await`
+    //[no_drop_tracking]~^^^^^^^^^^^^^^^ ERROR type inside `async fn` body must be known in this context
+    //[no_drop_tracking]~| ERROR type inside `async fn` body must be known in this context
+    //[no_drop_tracking]~| NOTE cannot infer type for type parameter `T`
+    //[no_drop_tracking]~| NOTE cannot infer type for type parameter `T`
+    //[no_drop_tracking]~| NOTE the type is part of the `async fn` body because of this `await`
+    //[no_drop_tracking]~| NOTE the type is part of the `async fn` body because of this `await`
+    //[no_drop_tracking]~| NOTE in this expansion of desugaring of `await`
+    //[no_drop_tracking]~| NOTE in this expansion of desugaring of `await`
 }
 fn main() {}
diff --git a/tests/ui/async-await/unresolved_type_param.stderr b/tests/ui/async-await/unresolved_type_param.stderr
index 7236c681f34..64a31b5fc32 100644
--- a/tests/ui/async-await/unresolved_type_param.stderr
+++ b/tests/ui/async-await/unresolved_type_param.stderr
@@ -1,35 +1,35 @@
 error[E0698]: type inside `async fn` body must be known in this context
-  --> $DIR/unresolved_type_param.rs:10:5
+  --> $DIR/unresolved_type_param.rs:13:5
    |
 LL |     bar().await;
    |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
    |
 note: the type is part of the `async fn` body because of this `await`
-  --> $DIR/unresolved_type_param.rs:10:10
+  --> $DIR/unresolved_type_param.rs:13:10
    |
 LL |     bar().await;
    |          ^^^^^^
 
 error[E0698]: type inside `async fn` body must be known in this context
-  --> $DIR/unresolved_type_param.rs:10:5
+  --> $DIR/unresolved_type_param.rs:13:5
    |
 LL |     bar().await;
    |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
    |
 note: the type is part of the `async fn` body because of this `await`
-  --> $DIR/unresolved_type_param.rs:10:10
+  --> $DIR/unresolved_type_param.rs:13:10
    |
 LL |     bar().await;
    |          ^^^^^^
 
 error[E0698]: type inside `async fn` body must be known in this context
-  --> $DIR/unresolved_type_param.rs:10:5
+  --> $DIR/unresolved_type_param.rs:13:5
    |
 LL |     bar().await;
    |     ^^^ cannot infer type for type parameter `T` declared on the function `bar`
    |
 note: the type is part of the `async fn` body because of this `await`
-  --> $DIR/unresolved_type_param.rs:10:10
+  --> $DIR/unresolved_type_param.rs:13:10
    |
 LL |     bar().await;
    |          ^^^^^^
diff --git a/tests/ui/attributes/key-value-expansion.stderr b/tests/ui/attributes/key-value-expansion.stderr
index 1b776322aaa..aaa8b169583 100644
--- a/tests/ui/attributes/key-value-expansion.stderr
+++ b/tests/ui/attributes/key-value-expansion.stderr
@@ -15,12 +15,7 @@ LL | bug!();
    |
    = note: this error originates in the macro `bug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: unexpected expression: `{
-               let res =
-                   ::alloc::fmt::format(::core::fmt::Arguments::new_v1(&[""],
-                           &[::core::fmt::ArgumentV1::new_display(&"u8")]));
-               res
-           }.as_str()`
+error: unexpected expression: `{ let res = ::alloc::fmt::format(format_args!("{0}", "u8")); res }.as_str()`
   --> $DIR/key-value-expansion.rs:48:23
    |
 LL |         doc_comment! {format!("{coor}", coor = stringify!($t1)).as_str()}
diff --git a/tests/ui/augmented-assignments.rs b/tests/ui/augmented-assignments.rs
index 20c7fb3a983..bd2435a78bf 100644
--- a/tests/ui/augmented-assignments.rs
+++ b/tests/ui/augmented-assignments.rs
@@ -9,7 +9,7 @@ impl AddAssign for Int {
 }
 
 fn main() {
-    let mut x = Int(1);
+    let mut x = Int(1); //~ NOTE binding `x` declared here
     x
     //~^ NOTE borrow of `x` occurs here
     +=
diff --git a/tests/ui/augmented-assignments.stderr b/tests/ui/augmented-assignments.stderr
index 2910c910d55..d1096aea279 100644
--- a/tests/ui/augmented-assignments.stderr
+++ b/tests/ui/augmented-assignments.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/augmented-assignments.rs:16:5
    |
+LL |     let mut x = Int(1);
+   |         ----- binding `x` declared here
 LL |     x
    |     - borrow of `x` occurs here
 ...
diff --git a/tests/ui/binop/binop-move-semantics.stderr b/tests/ui/binop/binop-move-semantics.stderr
index dae267da05d..8645169b98a 100644
--- a/tests/ui/binop/binop-move-semantics.stderr
+++ b/tests/ui/binop/binop-move-semantics.stderr
@@ -41,6 +41,8 @@ LL | fn move_then_borrow<T: Add<Output=()> + Clone + Copy>(x: T) {
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/binop-move-semantics.rs:21:5
    |
+LL | fn move_borrowed<T: Add<Output=()>>(x: T, mut y: T) {
+   |                                     - binding `x` declared here
 LL |     let m = &x;
    |             -- borrow of `x` occurs here
 ...
@@ -53,6 +55,9 @@ LL |     use_mut(n); use_imm(m);
 error[E0505]: cannot move out of `y` because it is borrowed
   --> $DIR/binop-move-semantics.rs:23:5
    |
+LL | fn move_borrowed<T: Add<Output=()>>(x: T, mut y: T) {
+   |                                           ----- binding `y` declared here
+LL |     let m = &x;
 LL |     let n = &mut y;
    |             ------ borrow of `y` occurs here
 ...
diff --git a/tests/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr b/tests/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
index 50eee1049db..5835f06753b 100644
--- a/tests/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
+++ b/tests/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
@@ -4,8 +4,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref foo @ [.., ref mut bar] => (),
    |         -------^^^^^^^^-----------^
    |         |              |
-   |         |              mutable borrow, by `bar`, occurs here
-   |         immutable borrow, by `foo`, occurs here
+   |         |              value is mutably borrowed by `bar` here
+   |         value is borrowed by `foo` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:120:9
@@ -13,8 +13,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref foo @ Some(box ref mut s) => (),
    |         -------^^^^^^^^^^^^---------^
    |         |                  |
-   |         |                  mutable borrow, by `s`, occurs here
-   |         immutable borrow, by `foo`, occurs here
+   |         |                  value is mutably borrowed by `s` here
+   |         value is borrowed by `foo` here
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:18:5
diff --git a/tests/ui/borrowck/borrow-tuple-fields.stderr b/tests/ui/borrowck/borrow-tuple-fields.stderr
index befa751a600..d7d3efe492c 100644
--- a/tests/ui/borrowck/borrow-tuple-fields.stderr
+++ b/tests/ui/borrowck/borrow-tuple-fields.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/borrow-tuple-fields.rs:12:13
    |
+LL |     let x: (Box<_>, _) = (Box::new(1), 2);
+   |         - binding `x` declared here
 LL |     let r = &x.0;
    |             ---- borrow of `x.0` occurs here
 LL |     let y = x;
@@ -32,6 +34,8 @@ LL |     a.use_ref();
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/borrow-tuple-fields.rs:28:13
    |
+LL |     let x = Foo(Box::new(1), 2);
+   |         - binding `x` declared here
 LL |     let r = &x.0;
    |             ---- borrow of `x.0` occurs here
 LL |     let y = x;
diff --git a/tests/ui/borrowck/borrowck-anon-fields-variant.stderr b/tests/ui/borrowck/borrowck-anon-fields-variant.stderr
index 98f6f00a7d4..c1d668f74ef 100644
--- a/tests/ui/borrowck/borrowck-anon-fields-variant.stderr
+++ b/tests/ui/borrowck/borrowck-anon-fields-variant.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `y` because it was mutably borrowed
   --> $DIR/borrowck-anon-fields-variant.rs:16:19
    |
 LL |       Foo::Y(ref mut a, _) => a,
-   |              --------- borrow of `y.0` occurs here
+   |              --------- `y.0` is borrowed here
 ...
 LL |     let b = match y {
    |                   ^ use of borrowed `y.0`
@@ -14,7 +14,7 @@ error[E0503]: cannot use `y` because it was mutably borrowed
   --> $DIR/borrowck-anon-fields-variant.rs:34:19
    |
 LL |       Foo::Y(ref mut a, _) => a,
-   |              --------- borrow of `y.0` occurs here
+   |              --------- `y.0` is borrowed here
 ...
 LL |     let b = match y {
    |                   ^ use of borrowed `y.0`
diff --git a/tests/ui/borrowck/borrowck-assign-comp.stderr b/tests/ui/borrowck/borrowck-assign-comp.stderr
index 2b7cef7b325..d35f2331a76 100644
--- a/tests/ui/borrowck/borrowck-assign-comp.stderr
+++ b/tests/ui/borrowck/borrowck-assign-comp.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `p.x` because it is borrowed
   --> $DIR/borrowck-assign-comp.rs:10:5
    |
 LL |     let q = &p;
-   |             -- borrow of `p.x` occurs here
+   |             -- `p.x` is borrowed here
 ...
 LL |     p.x = 5;
-   |     ^^^^^^^ assignment to borrowed `p.x` occurs here
+   |     ^^^^^^^ `p.x` is assigned to here but it was already borrowed
 LL |     q.x;
    |     --- borrow later used here
 
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `p` because it is borrowed
   --> $DIR/borrowck-assign-comp.rs:20:5
    |
 LL |     let q = &p.y;
-   |             ---- borrow of `p` occurs here
+   |             ---- `p` is borrowed here
 LL |     p = Point {x: 5, y: 7};
-   |     ^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `p` occurs here
+   |     ^^^^^^^^^^^^^^^^^^^^^^ `p` is assigned to here but it was already borrowed
 LL |     p.x; // silence warning
 LL |     *q; // stretch loan
    |     -- borrow later used here
@@ -24,9 +24,9 @@ error[E0506]: cannot assign to `p.y` because it is borrowed
   --> $DIR/borrowck-assign-comp.rs:31:5
    |
 LL |     let q = &p.y;
-   |             ---- borrow of `p.y` occurs here
+   |             ---- `p.y` is borrowed here
 LL |     p.y = 5;
-   |     ^^^^^^^ assignment to borrowed `p.y` occurs here
+   |     ^^^^^^^ `p.y` is assigned to here but it was already borrowed
 LL |     *q;
    |     -- borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-assign-to-andmut-in-borrowed-loc.stderr b/tests/ui/borrowck/borrowck-assign-to-andmut-in-borrowed-loc.stderr
index 0b21d113f74..8c0a8efcc18 100644
--- a/tests/ui/borrowck/borrowck-assign-to-andmut-in-borrowed-loc.stderr
+++ b/tests/ui/borrowck/borrowck-assign-to-andmut-in-borrowed-loc.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `*y.pointer` because it was mutably borrowed
   --> $DIR/borrowck-assign-to-andmut-in-borrowed-loc.rs:18:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `y` occurs here
+   |                                   ------ `y` is borrowed here
 LL |         *y.pointer += 1;
    |         ^^^^^^^^^^^^^^^ use of borrowed `y`
 ...
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `*y.pointer` because it is borrowed
   --> $DIR/borrowck-assign-to-andmut-in-borrowed-loc.rs:18:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `*y.pointer` occurs here
+   |                                   ------ `*y.pointer` is borrowed here
 LL |         *y.pointer += 1;
-   |         ^^^^^^^^^^^^^^^ assignment to borrowed `*y.pointer` occurs here
+   |         ^^^^^^^^^^^^^^^ `*y.pointer` is assigned to here but it was already borrowed
 ...
 LL |         *z.pointer += 1;
    |         --------------- borrow later used here
diff --git a/tests/ui/borrowck/borrowck-bad-nested-calls-move.stderr b/tests/ui/borrowck/borrowck-bad-nested-calls-move.stderr
index 371bcf2b69c..e582ec605de 100644
--- a/tests/ui/borrowck/borrowck-bad-nested-calls-move.stderr
+++ b/tests/ui/borrowck/borrowck-bad-nested-calls-move.stderr
@@ -1,6 +1,9 @@
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/borrowck-bad-nested-calls-move.rs:25:9
    |
+LL |     let mut a: Box<_> = Box::new(1);
+   |         ----- binding `a` declared here
+...
 LL |     add(
    |     --- borrow later used by call
 LL |         &*a,
@@ -11,6 +14,8 @@ LL |         a);
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/borrowck-bad-nested-calls-move.rs:32:9
    |
+LL |     let mut a: Box<_> = Box::new(1);
+   |         ----- binding `a` declared here
 LL |     add(
    |     --- borrow later used by call
 LL |         &*a,
diff --git a/tests/ui/borrowck/borrowck-closures-mut-and-imm.stderr b/tests/ui/borrowck/borrowck-closures-mut-and-imm.stderr
index fadcd11a592..8a7870e0c44 100644
--- a/tests/ui/borrowck/borrowck-closures-mut-and-imm.stderr
+++ b/tests/ui/borrowck/borrowck-closures-mut-and-imm.stderr
@@ -49,9 +49,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
 LL |     let c2 = || x * 5;
    |              -- - borrow occurs due to use in closure
    |              |
-   |              borrow of `x` occurs here
+   |              `x` is borrowed here
 LL |     x = 5;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |
 LL |     drop(c2);
    |          -- borrow later used here
@@ -62,9 +62,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
 LL |     let c1 = || get(&x);
    |              --      - borrow occurs due to use in closure
    |              |
-   |              borrow of `x` occurs here
+   |              `x` is borrowed here
 LL |     x = 5;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |
 LL |     drop(c1);
    |          -- borrow later used here
@@ -75,9 +75,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
 LL |     let c1 = || get(&*x);
    |              --      -- borrow occurs due to use in closure
    |              |
-   |              borrow of `*x` occurs here
+   |              `*x` is borrowed here
 LL |     *x = 5;
-   |     ^^^^^^ assignment to borrowed `*x` occurs here
+   |     ^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |
 LL |     drop(c1);
    |          -- borrow later used here
@@ -88,9 +88,9 @@ error[E0506]: cannot assign to `*x.f` because it is borrowed
 LL |     let c1 = || get(&*x.f);
    |              --      ---- borrow occurs due to use in closure
    |              |
-   |              borrow of `*x.f` occurs here
+   |              `*x.f` is borrowed here
 LL |     *x.f = 5;
-   |     ^^^^^^^^ assignment to borrowed `*x.f` occurs here
+   |     ^^^^^^^^ `*x.f` is assigned to here but it was already borrowed
 LL |
 LL |     drop(c1);
    |          -- borrow later used here
diff --git a/tests/ui/borrowck/borrowck-describe-lvalue.stderr b/tests/ui/borrowck/borrowck-describe-lvalue.stderr
index 2c1b9c10d46..cb29c9fdac3 100644
--- a/tests/ui/borrowck/borrowck-describe-lvalue.stderr
+++ b/tests/ui/borrowck/borrowck-describe-lvalue.stderr
@@ -45,7 +45,7 @@ error[E0503]: cannot use `f.x` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:37:9
    |
 LL |         let x = f.x();
-   |                 ----- borrow of `f` occurs here
+   |                 ----- `f` is borrowed here
 LL |         f.x;
    |         ^^^ use of borrowed `f`
 LL |         drop(x);
@@ -55,7 +55,7 @@ error[E0503]: cannot use `g.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:44:9
    |
 LL |         let x = g.x();
-   |                 ----- borrow of `g` occurs here
+   |                 ----- `g` is borrowed here
 LL |         g.0;
    |         ^^^ use of borrowed `g`
 LL |         drop(x);
@@ -65,7 +65,7 @@ error[E0503]: cannot use `h.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:51:9
    |
 LL |         let x = &mut h.0;
-   |                 -------- borrow of `h.0` occurs here
+   |                 -------- `h.0` is borrowed here
 LL |         h.0;
    |         ^^^ use of borrowed `h.0`
 LL |         drop(x);
@@ -75,7 +75,7 @@ error[E0503]: cannot use `e.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:59:20
    |
 LL |         let x = e.x();
-   |                 ----- borrow of `e` occurs here
+   |                 ----- `e` is borrowed here
 LL |         match e {
 LL |             Baz::X(value) => value
    |                    ^^^^^ use of borrowed `e`
@@ -87,7 +87,7 @@ error[E0503]: cannot use `u.a` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:67:9
    |
 LL |         let x = &mut u.a;
-   |                 -------- borrow of `u.a` occurs here
+   |                 -------- `u.a` is borrowed here
 LL |         u.a;
    |         ^^^ use of borrowed `u.a`
 LL |         drop(x);
@@ -97,7 +97,7 @@ error[E0503]: cannot use `f.x` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:74:9
    |
 LL |         let x = f.x();
-   |                 ----- borrow of `*f` occurs here
+   |                 ----- `*f` is borrowed here
 LL |         f.x;
    |         ^^^ use of borrowed `*f`
 LL |         drop(x);
@@ -107,7 +107,7 @@ error[E0503]: cannot use `g.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:81:9
    |
 LL |         let x = g.x();
-   |                 ----- borrow of `*g` occurs here
+   |                 ----- `*g` is borrowed here
 LL |         g.0;
    |         ^^^ use of borrowed `*g`
 LL |         drop(x);
@@ -117,7 +117,7 @@ error[E0503]: cannot use `h.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:88:9
    |
 LL |         let x = &mut h.0;
-   |                 -------- borrow of `h.0` occurs here
+   |                 -------- `h.0` is borrowed here
 LL |         h.0;
    |         ^^^ use of borrowed `h.0`
 LL |         drop(x);
@@ -127,7 +127,7 @@ error[E0503]: cannot use `e.0` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:96:20
    |
 LL |         let x = e.x();
-   |                 ----- borrow of `*e` occurs here
+   |                 ----- `*e` is borrowed here
 LL |         match *e {
 LL |             Baz::X(value) => value
    |                    ^^^^^ use of borrowed `*e`
@@ -139,7 +139,7 @@ error[E0503]: cannot use `u.a` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:105:9
    |
 LL |         let x = &mut u.a;
-   |                 -------- borrow of `u.a` occurs here
+   |                 -------- `u.a` is borrowed here
 LL |         u.a;
    |         ^^^ use of borrowed `u.a`
 LL |         drop(x);
@@ -149,7 +149,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:113:15
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 LL |         match v {
 LL |             &[x, _, .., _, _] => println!("{}", x),
    |               ^ use of borrowed `v`
@@ -161,7 +161,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:118:18
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[_, x, .., _, _] => println!("{}", x),
    |                  ^ use of borrowed `v`
@@ -173,7 +173,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:123:25
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[_, _, .., x, _] => println!("{}", x),
    |                         ^ use of borrowed `v`
@@ -185,7 +185,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:128:28
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[_, _, .., _, x] => println!("{}", x),
    |                            ^ use of borrowed `v`
@@ -197,7 +197,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:139:15
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 LL |         match v {
 LL |             &[x @ ..] => println!("{:?}", x),
    |               ^ use of borrowed `v`
@@ -209,7 +209,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:144:18
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[_, x @ ..] => println!("{:?}", x),
    |                  ^ use of borrowed `v`
@@ -221,7 +221,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:149:15
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[x @ .., _] => println!("{:?}", x),
    |               ^ use of borrowed `v`
@@ -233,7 +233,7 @@ error[E0503]: cannot use `v[..]` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:154:18
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 ...
 LL |             &[_, x @ .., _] => println!("{:?}", x),
    |                  ^ use of borrowed `v`
@@ -245,7 +245,7 @@ error[E0503]: cannot use `e` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:166:15
    |
 LL |         let x = &mut e;
-   |                 ------ borrow of `e` occurs here
+   |                 ------ `e` is borrowed here
 LL |         match e {
    |               ^ use of borrowed `e`
 ...
@@ -304,7 +304,7 @@ error[E0503]: cannot use `*v` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:232:9
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 LL |         v[0].y;
    |         ^^^^ use of borrowed `v`
 ...
@@ -315,7 +315,7 @@ error[E0503]: cannot use `v[_].y` because it was mutably borrowed
   --> $DIR/borrowck-describe-lvalue.rs:232:9
    |
 LL |         let x = &mut v;
-   |                 ------ borrow of `v` occurs here
+   |                 ------ `v` is borrowed here
 LL |         v[0].y;
    |         ^^^^^^ use of borrowed `v`
 ...
diff --git a/tests/ui/borrowck/borrowck-field-sensitivity.stderr b/tests/ui/borrowck/borrowck-field-sensitivity.stderr
index e009f5913ed..11812847dd1 100644
--- a/tests/ui/borrowck/borrowck-field-sensitivity.stderr
+++ b/tests/ui/borrowck/borrowck-field-sensitivity.stderr
@@ -41,6 +41,8 @@ LL |     let p = &x.b;
 error[E0505]: cannot move out of `x.b` because it is borrowed
   --> $DIR/borrowck-field-sensitivity.rs:34:10
    |
+LL |     let x = A { a: 1, b: Box::new(2) };
+   |         - binding `x` declared here
 LL |     let p = &x.b;
    |             ---- borrow of `x.b` occurs here
 LL |     drop(x.b);
@@ -51,6 +53,8 @@ LL |     drop(**p);
 error[E0505]: cannot move out of `x.b` because it is borrowed
   --> $DIR/borrowck-field-sensitivity.rs:41:14
    |
+LL |     let x = A { a: 1, b: Box::new(2) };
+   |         - binding `x` declared here
 LL |     let p = &x.b;
    |             ---- borrow of `x.b` occurs here
 LL |     let _y = A { a: 3, .. x };
diff --git a/tests/ui/borrowck/borrowck-imm-ref-to-mut-rec-field-issue-3162-c.stderr b/tests/ui/borrowck/borrowck-imm-ref-to-mut-rec-field-issue-3162-c.stderr
index a66db05ccc5..1a20ec85fc0 100644
--- a/tests/ui/borrowck/borrowck-imm-ref-to-mut-rec-field-issue-3162-c.stderr
+++ b/tests/ui/borrowck/borrowck-imm-ref-to-mut-rec-field-issue-3162-c.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `_a` because it is borrowed
   --> $DIR/borrowck-imm-ref-to-mut-rec-field-issue-3162-c.rs:6:9
    |
 LL |     let b = &mut _a;
-   |             ------- borrow of `_a` occurs here
+   |             ------- `_a` is borrowed here
 ...
 LL |         _a = 4;
-   |         ^^^^^^ assignment to borrowed `_a` occurs here
+   |         ^^^^^^ `_a` is assigned to here but it was already borrowed
 ...
 LL |     drop(b);
    |          - borrow later used here
diff --git a/tests/ui/borrowck/borrowck-issue-14498.stderr b/tests/ui/borrowck/borrowck-issue-14498.stderr
index 42a55b7a854..374c5ee3ed2 100644
--- a/tests/ui/borrowck/borrowck-issue-14498.stderr
+++ b/tests/ui/borrowck/borrowck-issue-14498.stderr
@@ -13,10 +13,10 @@ error[E0506]: cannot assign to `**y` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:25:5
    |
 LL |     let p = &y;
-   |             -- borrow of `**y` occurs here
+   |             -- `**y` is borrowed here
 LL |     let q = &***p;
 LL |     **y = 2;
-   |     ^^^^^^^ assignment to borrowed `**y` occurs here
+   |     ^^^^^^^ `**y` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -24,10 +24,10 @@ error[E0506]: cannot assign to `**y` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:35:5
    |
 LL |     let p = &y;
-   |             -- borrow of `**y` occurs here
+   |             -- `**y` is borrowed here
 LL |     let q = &***p;
 LL |     **y = 2;
-   |     ^^^^^^^ assignment to borrowed `**y` occurs here
+   |     ^^^^^^^ `**y` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -35,10 +35,10 @@ error[E0506]: cannot assign to `**y` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:45:5
    |
 LL |     let p = &y;
-   |             -- borrow of `**y` occurs here
+   |             -- `**y` is borrowed here
 LL |     let q = &***p;
 LL |     **y = 2;
-   |     ^^^^^^^ assignment to borrowed `**y` occurs here
+   |     ^^^^^^^ `**y` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -46,10 +46,10 @@ error[E0506]: cannot assign to `**y` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:55:5
    |
 LL |     let p = &y;
-   |             -- borrow of `**y` occurs here
+   |             -- `**y` is borrowed here
 LL |     let q = &***p;
 LL |     **y = 2;
-   |     ^^^^^^^ assignment to borrowed `**y` occurs here
+   |     ^^^^^^^ `**y` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -57,10 +57,10 @@ error[E0506]: cannot assign to `**y.a` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:65:5
    |
 LL |     let p = &y.a;
-   |             ---- borrow of `**y.a` occurs here
+   |             ---- `**y.a` is borrowed here
 LL |     let q = &***p;
 LL |     **y.a = 2;
-   |     ^^^^^^^^^ assignment to borrowed `**y.a` occurs here
+   |     ^^^^^^^^^ `**y.a` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -68,10 +68,10 @@ error[E0506]: cannot assign to `**y.a` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:75:5
    |
 LL |     let p = &y.a;
-   |             ---- borrow of `**y.a` occurs here
+   |             ---- `**y.a` is borrowed here
 LL |     let q = &***p;
 LL |     **y.a = 2;
-   |     ^^^^^^^^^ assignment to borrowed `**y.a` occurs here
+   |     ^^^^^^^^^ `**y.a` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -79,10 +79,10 @@ error[E0506]: cannot assign to `**y.a` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:85:5
    |
 LL |     let p = &y.a;
-   |             ---- borrow of `**y.a` occurs here
+   |             ---- `**y.a` is borrowed here
 LL |     let q = &***p;
 LL |     **y.a = 2;
-   |     ^^^^^^^^^ assignment to borrowed `**y.a` occurs here
+   |     ^^^^^^^^^ `**y.a` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
@@ -90,10 +90,10 @@ error[E0506]: cannot assign to `**y.a` because it is borrowed
   --> $DIR/borrowck-issue-14498.rs:95:5
    |
 LL |     let p = &y.a;
-   |             ---- borrow of `**y.a` occurs here
+   |             ---- `**y.a` is borrowed here
 LL |     let q = &***p;
 LL |     **y.a = 2;
-   |     ^^^^^^^^^ assignment to borrowed `**y.a` occurs here
+   |     ^^^^^^^^^ `**y.a` is assigned to here but it was already borrowed
 LL |     drop(p);
    |          - borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-lend-flow-match.stderr b/tests/ui/borrowck/borrowck-lend-flow-match.stderr
index 66f1cd9bd56..6cdce7bee88 100644
--- a/tests/ui/borrowck/borrowck-lend-flow-match.stderr
+++ b/tests/ui/borrowck/borrowck-lend-flow-match.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/borrowck-lend-flow-match.rs:12:13
    |
 LL |         Some(ref r) => {
-   |              ----- borrow of `x` occurs here
+   |              ----- `x` is borrowed here
 LL |             x = Some(1);
-   |             ^^^^^^^^^^^ assignment to borrowed `x` occurs here
+   |             ^^^^^^^^^^^ `x` is assigned to here but it was already borrowed
 LL |             drop(r);
    |                  - borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-loan-blocks-move-cc.stderr b/tests/ui/borrowck/borrowck-loan-blocks-move-cc.stderr
index 3548da35b61..6eabfff9054 100644
--- a/tests/ui/borrowck/borrowck-loan-blocks-move-cc.stderr
+++ b/tests/ui/borrowck/borrowck-loan-blocks-move-cc.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `v` because it is borrowed
   --> $DIR/borrowck-loan-blocks-move-cc.rs:14:19
    |
+LL |     let v: Box<_> = Box::new(3);
+   |         - binding `v` declared here
 LL |     let w = &v;
    |             -- borrow of `v` occurs here
 LL |     thread::spawn(move|| {
@@ -15,6 +17,8 @@ LL |     w.use_ref();
 error[E0505]: cannot move out of `v` because it is borrowed
   --> $DIR/borrowck-loan-blocks-move-cc.rs:24:19
    |
+LL |     let v: Box<_> = Box::new(3);
+   |         - binding `v` declared here
 LL |     let w = &v;
    |             -- borrow of `v` occurs here
 LL |     thread::spawn(move|| {
diff --git a/tests/ui/borrowck/borrowck-loan-blocks-move.stderr b/tests/ui/borrowck/borrowck-loan-blocks-move.stderr
index b5c6b101f76..38e06fa0187 100644
--- a/tests/ui/borrowck/borrowck-loan-blocks-move.stderr
+++ b/tests/ui/borrowck/borrowck-loan-blocks-move.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `v` because it is borrowed
   --> $DIR/borrowck-loan-blocks-move.rs:11:10
    |
+LL |     let v = Box::new(3);
+   |         - binding `v` declared here
 LL |     let w = &v;
    |             -- borrow of `v` occurs here
 LL |     take(v);
diff --git a/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.stderr b/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.stderr
index 6994c837dfc..311369a260d 100644
--- a/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.stderr
+++ b/tests/ui/borrowck/borrowck-loan-of-static-data-issue-27616.stderr
@@ -2,12 +2,12 @@ error[E0506]: cannot assign to `*s` because it is borrowed
   --> $DIR/borrowck-loan-of-static-data-issue-27616.rs:16:5
    |
 LL |     let alias: &'static mut String = s;
-   |                -------------------   - borrow of `*s` occurs here
+   |                -------------------   - `*s` is borrowed here
    |                |
    |                type annotation requires that `*s` is borrowed for `'static`
 ...
 LL |     *s = String::new();
-   |     ^^ assignment to borrowed `*s` occurs here
+   |     ^^ `*s` is assigned to here but it was already borrowed
 
 error: aborting due to previous error
 
diff --git a/tests/ui/borrowck/borrowck-loan-rcvr-overloaded-op.stderr b/tests/ui/borrowck/borrowck-loan-rcvr-overloaded-op.stderr
index 24cc4933ef1..f1640d3b777 100644
--- a/tests/ui/borrowck/borrowck-loan-rcvr-overloaded-op.stderr
+++ b/tests/ui/borrowck/borrowck-loan-rcvr-overloaded-op.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `p` because it was mutably borrowed
   --> $DIR/borrowck-loan-rcvr-overloaded-op.rs:38:5
    |
 LL |     let q = &mut p;
-   |             ------ borrow of `p` occurs here
+   |             ------ `p` is borrowed here
 LL |
 LL |     p + 3;
    |     ^ use of borrowed `p`
diff --git a/tests/ui/borrowck/borrowck-local-borrow-with-panic-outlives-fn.stderr b/tests/ui/borrowck/borrowck-local-borrow-with-panic-outlives-fn.stderr
index 6ea6951ad96..0fdb1dabbc5 100644
--- a/tests/ui/borrowck/borrowck-local-borrow-with-panic-outlives-fn.stderr
+++ b/tests/ui/borrowck/borrowck-local-borrow-with-panic-outlives-fn.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `z.1` does not live long enough
   --> $DIR/borrowck-local-borrow-with-panic-outlives-fn.rs:3:15
    |
+LL |     let mut z = (0, 0);
+   |         ----- binding `z` declared here
 LL |     *x = Some(&mut z.1);
    |     ----------^^^^^^^^-
    |     |         |
diff --git a/tests/ui/borrowck/borrowck-match-already-borrowed.stderr b/tests/ui/borrowck/borrowck-match-already-borrowed.stderr
index 39047be9de6..e5c0ec960a4 100644
--- a/tests/ui/borrowck/borrowck-match-already-borrowed.stderr
+++ b/tests/ui/borrowck/borrowck-match-already-borrowed.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `foo` because it was mutably borrowed
   --> $DIR/borrowck-match-already-borrowed.rs:9:19
    |
 LL |     let p = &mut foo;
-   |             -------- borrow of `foo` occurs here
+   |             -------- `foo` is borrowed here
 LL |     let _ = match foo {
    |                   ^^^ use of borrowed `foo`
 ...
@@ -13,7 +13,7 @@ error[E0503]: cannot use `foo.0` because it was mutably borrowed
   --> $DIR/borrowck-match-already-borrowed.rs:12:16
    |
 LL |     let p = &mut foo;
-   |             -------- borrow of `foo` occurs here
+   |             -------- `foo` is borrowed here
 ...
 LL |         Foo::A(x) => x
    |                ^ use of borrowed `foo`
@@ -25,7 +25,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/borrowck-match-already-borrowed.rs:22:9
    |
 LL |     let r = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     let _ = match x {
 LL |         x => x + 1,
    |         ^ use of borrowed `x`
@@ -37,7 +37,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/borrowck-match-already-borrowed.rs:23:9
    |
 LL |     let r = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 ...
 LL |         y => y + 2,
    |         ^ use of borrowed `x`
diff --git a/tests/ui/borrowck/borrowck-move-by-capture.stderr b/tests/ui/borrowck/borrowck-move-by-capture.stderr
index 8ddc48b2a99..6eaa1fa3169 100644
--- a/tests/ui/borrowck/borrowck-move-by-capture.stderr
+++ b/tests/ui/borrowck/borrowck-move-by-capture.stderr
@@ -10,7 +10,7 @@ LL |         let _h = to_fn_once(move || -> isize { *bar });
    |                             |                  |
    |                             |                  variable moved due to use in closure
    |                             |                  move occurs because `bar` has type `Box<isize>`, which does not implement the `Copy` trait
-   |                             move out of `bar` occurs here
+   |                             `bar` is moved here
 
 error: aborting due to previous error
 
diff --git a/tests/ui/borrowck/borrowck-move-from-subpath-of-borrowed-path.stderr b/tests/ui/borrowck/borrowck-move-from-subpath-of-borrowed-path.stderr
index f833abcc02a..bd94f1a4299 100644
--- a/tests/ui/borrowck/borrowck-move-from-subpath-of-borrowed-path.stderr
+++ b/tests/ui/borrowck/borrowck-move-from-subpath-of-borrowed-path.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `*a` because it is borrowed
   --> $DIR/borrowck-move-from-subpath-of-borrowed-path.rs:12:13
    |
+LL |     let a: Box<Box<_>> = Box::new(Box::new(2));
+   |         - binding `a` declared here
 LL |     let b = &a;
    |             -- borrow of `a` occurs here
 LL |
diff --git a/tests/ui/borrowck/borrowck-move-mut-base-ptr.stderr b/tests/ui/borrowck/borrowck-move-mut-base-ptr.stderr
index d5ff0c501c4..cdad20c52bf 100644
--- a/tests/ui/borrowck/borrowck-move-mut-base-ptr.stderr
+++ b/tests/ui/borrowck/borrowck-move-mut-base-ptr.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `t0` because it is borrowed
   --> $DIR/borrowck-move-mut-base-ptr.rs:10:14
    |
+LL | fn foo(t0: &mut isize) {
+   |        -- binding `t0` declared here
 LL |     let p: &isize = &*t0; // Freezes `*t0`
    |                     ---- borrow of `*t0` occurs here
 LL |     let t1 = t0;
diff --git a/tests/ui/borrowck/borrowck-move-subcomponent.stderr b/tests/ui/borrowck/borrowck-move-subcomponent.stderr
index 8c9083fcf13..341146bd18f 100644
--- a/tests/ui/borrowck/borrowck-move-subcomponent.stderr
+++ b/tests/ui/borrowck/borrowck-move-subcomponent.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `a.x` because it is borrowed
   --> $DIR/borrowck-move-subcomponent.rs:15:14
    |
+LL |   let a : S = S { x : Box::new(1) };
+   |       - binding `a` declared here
 LL |   let pb = &a;
    |            -- borrow of `a` occurs here
 LL |   let S { x: ax } = a;
diff --git a/tests/ui/borrowck/borrowck-multiple-captures.stderr b/tests/ui/borrowck/borrowck-multiple-captures.stderr
index f94cbc30db4..70abe7b346e 100644
--- a/tests/ui/borrowck/borrowck-multiple-captures.stderr
+++ b/tests/ui/borrowck/borrowck-multiple-captures.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x1` because it is borrowed
   --> $DIR/borrowck-multiple-captures.rs:12:19
    |
+LL |     let x1: Box<_> = Box::new(1);
+   |         -- binding `x1` declared here
 LL |     let p1 = &x1;
    |              --- borrow of `x1` occurs here
 ...
@@ -16,6 +18,8 @@ LL |     borrow(&*p1);
 error[E0505]: cannot move out of `x2` because it is borrowed
   --> $DIR/borrowck-multiple-captures.rs:12:19
    |
+LL |     let x2: Box<_> = Box::new(2);
+   |         -- binding `x2` declared here
 LL |     let p2 = &x2;
    |              --- borrow of `x2` occurs here
 LL |     thread::spawn(move|| {
@@ -77,6 +81,8 @@ LL |         drop(x);
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/borrowck-multiple-captures.rs:38:19
    |
+LL |     let x: Box<_> = Box::new(1);
+   |         - binding `x` declared here
 LL |     let p = &x;
    |             -- borrow of `x` occurs here
 LL |     thread::spawn(move|| {
diff --git a/tests/ui/borrowck/borrowck-overloaded-index-and-overloaded-deref.stderr b/tests/ui/borrowck/borrowck-overloaded-index-and-overloaded-deref.stderr
index 5d52e491918..7f42becd21c 100644
--- a/tests/ui/borrowck/borrowck-overloaded-index-and-overloaded-deref.stderr
+++ b/tests/ui/borrowck/borrowck-overloaded-index-and-overloaded-deref.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `v` because it is borrowed
   --> $DIR/borrowck-overloaded-index-and-overloaded-deref.rs:31:5
    |
 LL |     let i = &v[0].f;
-   |              - borrow of `v` occurs here
+   |              - `v` is borrowed here
 LL |     v = MyVec { x: MyPtr { x: Foo { f: 23 } } };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `v` occurs here
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `v` is assigned to here but it was already borrowed
 LL |
 LL |     read(*i);
    |          -- borrow later used here
diff --git a/tests/ui/borrowck/borrowck-overloaded-index-autoderef.stderr b/tests/ui/borrowck/borrowck-overloaded-index-autoderef.stderr
index 087f2ac799e..fb7af50bcb5 100644
--- a/tests/ui/borrowck/borrowck-overloaded-index-autoderef.stderr
+++ b/tests/ui/borrowck/borrowck-overloaded-index-autoderef.stderr
@@ -42,9 +42,9 @@ error[E0506]: cannot assign to `f.foo` because it is borrowed
   --> $DIR/borrowck-overloaded-index-autoderef.rs:71:5
    |
 LL |     let p = &f.foo[&s];
-   |              ----- borrow of `f.foo` occurs here
+   |              ----- `f.foo` is borrowed here
 LL |     f.foo = g;
-   |     ^^^^^^^^^ assignment to borrowed `f.foo` occurs here
+   |     ^^^^^^^^^ `f.foo` is assigned to here but it was already borrowed
 LL |     p.use_ref();
    |     ----------- borrow later used here
 
@@ -52,9 +52,9 @@ error[E0506]: cannot assign to `*f` because it is borrowed
   --> $DIR/borrowck-overloaded-index-autoderef.rs:77:5
    |
 LL |     let p = &f.foo[&s];
-   |              ----- borrow of `*f` occurs here
+   |              ----- `*f` is borrowed here
 LL |     *f = g;
-   |     ^^^^^^ assignment to borrowed `*f` occurs here
+   |     ^^^^^^ `*f` is assigned to here but it was already borrowed
 LL |     p.use_ref();
    |     ----------- borrow later used here
 
@@ -62,9 +62,9 @@ error[E0506]: cannot assign to `f.foo` because it is borrowed
   --> $DIR/borrowck-overloaded-index-autoderef.rs:83:5
    |
 LL |     let p = &mut f.foo[&s];
-   |                  ----- borrow of `f.foo` occurs here
+   |                  ----- `f.foo` is borrowed here
 LL |     f.foo = g;
-   |     ^^^^^^^^^ assignment to borrowed `f.foo` occurs here
+   |     ^^^^^^^^^ `f.foo` is assigned to here but it was already borrowed
 LL |     p.use_mut();
    |     ----------- borrow later used here
 
@@ -72,9 +72,9 @@ error[E0506]: cannot assign to `*f` because it is borrowed
   --> $DIR/borrowck-overloaded-index-autoderef.rs:89:5
    |
 LL |     let p = &mut f.foo[&s];
-   |                  ----- borrow of `*f` occurs here
+   |                  ----- `*f` is borrowed here
 LL |     *f = g;
-   |     ^^^^^^ assignment to borrowed `*f` occurs here
+   |     ^^^^^^ `*f` is assigned to here but it was already borrowed
 LL |     p.use_mut();
    |     ----------- borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-overloaded-index-move-index.stderr b/tests/ui/borrowck/borrowck-overloaded-index-move-index.stderr
index fb0e274c291..7f8cc74a715 100644
--- a/tests/ui/borrowck/borrowck-overloaded-index-move-index.stderr
+++ b/tests/ui/borrowck/borrowck-overloaded-index-move-index.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `s` because it is borrowed
   --> $DIR/borrowck-overloaded-index-move-index.rs:50:22
    |
+LL |     let mut s = "hello".to_string();
+   |         ----- binding `s` declared here
 LL |     let rs = &mut s;
    |              ------ borrow of `s` occurs here
 LL |
@@ -13,6 +15,8 @@ LL |     use_mut(rs);
 error[E0505]: cannot move out of `s` because it is borrowed
   --> $DIR/borrowck-overloaded-index-move-index.rs:53:7
    |
+LL |     let mut s = "hello".to_string();
+   |         ----- binding `s` declared here
 LL |     let rs = &mut s;
    |              ------ borrow of `s` occurs here
 ...
diff --git a/tests/ui/borrowck/borrowck-pat-reassign-binding.stderr b/tests/ui/borrowck/borrowck-pat-reassign-binding.stderr
index 9e65ccf5a19..b86a8693881 100644
--- a/tests/ui/borrowck/borrowck-pat-reassign-binding.stderr
+++ b/tests/ui/borrowck/borrowck-pat-reassign-binding.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/borrowck-pat-reassign-binding.rs:10:11
    |
 LL |       Some(ref i) => {
-   |            ----- borrow of `x` occurs here
+   |            ----- `x` is borrowed here
 LL |           // But on this branch, `i` is an outstanding borrow
 LL |           x = Some(*i+1);
-   |           ^^^^^^^^^^^^^^ assignment to borrowed `x` occurs here
+   |           ^^^^^^^^^^^^^^ `x` is assigned to here but it was already borrowed
 LL |           drop(i);
    |                - borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-unary-move.stderr b/tests/ui/borrowck/borrowck-unary-move.stderr
index aab225ed4a4..f3b962059f5 100644
--- a/tests/ui/borrowck/borrowck-unary-move.stderr
+++ b/tests/ui/borrowck/borrowck-unary-move.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/borrowck-unary-move.rs:3:10
    |
+LL | fn foo(x: Box<isize>) -> isize {
+   |        - binding `x` declared here
 LL |     let y = &*x;
    |             --- borrow of `*x` occurs here
 LL |     free(x);
diff --git a/tests/ui/borrowck/borrowck-union-borrow-nested.stderr b/tests/ui/borrowck/borrowck-union-borrow-nested.stderr
index 4bd7d54cffe..a87a14e7cab 100644
--- a/tests/ui/borrowck/borrowck-union-borrow-nested.stderr
+++ b/tests/ui/borrowck/borrowck-union-borrow-nested.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `u.c` because it was mutably borrowed
   --> $DIR/borrowck-union-borrow-nested.rs:24:21
    |
 LL |             let ra = &mut u.s.a;
-   |                      ---------- borrow of `u.s.a` occurs here
+   |                      ---------- `u.s.a` is borrowed here
 LL |             let b = u.c;
    |                     ^^^ use of borrowed `u.s.a`
 LL |             ra.use_mut();
diff --git a/tests/ui/borrowck/borrowck-union-borrow.stderr b/tests/ui/borrowck/borrowck-union-borrow.stderr
index 090c7b6b51a..11a28f6744b 100644
--- a/tests/ui/borrowck/borrowck-union-borrow.stderr
+++ b/tests/ui/borrowck/borrowck-union-borrow.stderr
@@ -12,9 +12,9 @@ error[E0506]: cannot assign to `u.a` because it is borrowed
   --> $DIR/borrowck-union-borrow.rs:28:13
    |
 LL |             let ra = &u.a;
-   |                      ---- borrow of `u.a` occurs here
+   |                      ---- `u.a` is borrowed here
 LL |             u.a = 1;
-   |             ^^^^^^^ assignment to borrowed `u.a` occurs here
+   |             ^^^^^^^ `u.a` is assigned to here but it was already borrowed
 LL |             drop(ra);
    |                  -- borrow later used here
 
@@ -34,9 +34,9 @@ error[E0506]: cannot assign to `u.b` because it is borrowed
   --> $DIR/borrowck-union-borrow.rs:49:13
    |
 LL |             let ra = &u.a;
-   |                      ---- borrow of `u.b` occurs here
+   |                      ---- `u.b` is borrowed here
 LL |             u.b = 1;
-   |             ^^^^^^^ assignment to borrowed `u.b` occurs here
+   |             ^^^^^^^ `u.b` is assigned to here but it was already borrowed
 LL |             drop(ra);
    |                  -- borrow later used here
 
@@ -54,7 +54,7 @@ error[E0503]: cannot use `u.a` because it was mutably borrowed
   --> $DIR/borrowck-union-borrow.rs:60:21
    |
 LL |             let ra = &mut u.a;
-   |                      -------- borrow of `u.a` occurs here
+   |                      -------- `u.a` is borrowed here
 LL |             let a = u.a;
    |                     ^^^ use of borrowed `u.a`
 LL |             drop(ra);
@@ -74,9 +74,9 @@ error[E0506]: cannot assign to `u.a` because it is borrowed
   --> $DIR/borrowck-union-borrow.rs:70:13
    |
 LL |             let rma = &mut u.a;
-   |                       -------- borrow of `u.a` occurs here
+   |                       -------- `u.a` is borrowed here
 LL |             u.a = 1;
-   |             ^^^^^^^ assignment to borrowed `u.a` occurs here
+   |             ^^^^^^^ `u.a` is assigned to here but it was already borrowed
 LL |             drop(rma);
    |                  --- borrow later used here
 
@@ -96,7 +96,7 @@ error[E0503]: cannot use `u.b` because it was mutably borrowed
   --> $DIR/borrowck-union-borrow.rs:81:21
    |
 LL |             let ra = &mut u.a;
-   |                      -------- borrow of `u.a` occurs here
+   |                      -------- `u.a` is borrowed here
 LL |             let b = u.b;
    |                     ^^^ use of borrowed `u.a`
 LL |
@@ -119,9 +119,9 @@ error[E0506]: cannot assign to `u.b` because it is borrowed
   --> $DIR/borrowck-union-borrow.rs:92:13
    |
 LL |             let rma = &mut u.a;
-   |                       -------- borrow of `u.b` occurs here
+   |                       -------- `u.b` is borrowed here
 LL |             u.b = 1;
-   |             ^^^^^^^ assignment to borrowed `u.b` occurs here
+   |             ^^^^^^^ `u.b` is assigned to here but it was already borrowed
 LL |             drop(rma);
    |                  --- borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-use-mut-borrow.stderr b/tests/ui/borrowck/borrowck-use-mut-borrow.stderr
index 91d69c51e81..4d300ae3c52 100644
--- a/tests/ui/borrowck/borrowck-use-mut-borrow.stderr
+++ b/tests/ui/borrowck/borrowck-use-mut-borrow.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:11:10
    |
 LL |     let p = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     drop(x);
    |          ^ use of borrowed `x`
 LL |     *p = 2;
@@ -12,7 +12,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:18:10
    |
 LL |     let p = &mut x.a;
-   |             -------- borrow of `x.a` occurs here
+   |             -------- `x.a` is borrowed here
 LL |     drop(x);
    |          ^ use of borrowed `x.a`
 LL |     *p = 3;
@@ -22,7 +22,7 @@ error[E0503]: cannot use `x.a` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:25:10
    |
 LL |     let p = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     drop(x.a);
    |          ^^^ use of borrowed `x`
 LL |     p.a = 3;
@@ -32,7 +32,7 @@ error[E0503]: cannot use `x.a` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:32:10
    |
 LL |     let p = &mut x.a;
-   |             -------- borrow of `x.a` occurs here
+   |             -------- `x.a` is borrowed here
 LL |     drop(x.a);
    |          ^^^ use of borrowed `x.a`
 LL |     *p = 3;
@@ -42,7 +42,7 @@ error[E0503]: cannot use `x.a` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:39:13
    |
 LL |     let p = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     let y = A { b: 3, .. x };
    |             ^^^^^^^^^^^^^^^^ use of borrowed `x`
 LL |     drop(y);
@@ -53,7 +53,7 @@ error[E0503]: cannot use `x.a` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:47:13
    |
 LL |     let p = &mut x.a;
-   |             -------- borrow of `x.a` occurs here
+   |             -------- `x.a` is borrowed here
 LL |     let y = A { b: 3, .. x };
    |             ^^^^^^^^^^^^^^^^ use of borrowed `x.a`
 LL |     drop(y);
@@ -64,7 +64,7 @@ error[E0503]: cannot use `*x` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:55:10
    |
 LL |     let p = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     drop(*x);
    |          ^^ use of borrowed `x`
 LL |     **p = 2;
@@ -74,7 +74,7 @@ error[E0503]: cannot use `*x.b` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:62:10
    |
 LL |     let p = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     drop(*x.b);
    |          ^^^^ use of borrowed `x`
 LL |     p.a = 3;
@@ -84,7 +84,7 @@ error[E0503]: cannot use `*x.b` because it was mutably borrowed
   --> $DIR/borrowck-use-mut-borrow.rs:69:10
    |
 LL |     let p = &mut x.b;
-   |             -------- borrow of `x.b` occurs here
+   |             -------- `x.b` is borrowed here
 LL |     drop(*x.b);
    |          ^^^^ use of borrowed `x.b`
 LL |     **p = 3;
diff --git a/tests/ui/borrowck/borrowck-vec-pattern-move-tail.stderr b/tests/ui/borrowck/borrowck-vec-pattern-move-tail.stderr
index 0ac7df944d7..494d8c351a1 100644
--- a/tests/ui/borrowck/borrowck-vec-pattern-move-tail.stderr
+++ b/tests/ui/borrowck/borrowck-vec-pattern-move-tail.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `a[_]` because it is borrowed
   --> $DIR/borrowck-vec-pattern-move-tail.rs:8:5
    |
 LL |         [1, 2, ref tail @ ..] => tail,
-   |                -------- borrow of `a[_]` occurs here
+   |                -------- `a[_]` is borrowed here
 ...
 LL |     a[2] = 0;
-   |     ^^^^^^^^ assignment to borrowed `a[_]` occurs here
+   |     ^^^^^^^^ `a[_]` is assigned to here but it was already borrowed
 LL |     println!("t[0]: {}", t[0]);
    |                          ---- borrow later used here
 
diff --git a/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs b/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs
index 0e9284a2cad..1bda7a49713 100644
--- a/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs
+++ b/tests/ui/borrowck/borrowck-vec-pattern-nesting.rs
@@ -5,9 +5,9 @@ fn a() {
     let mut vec = [Box::new(1), Box::new(2), Box::new(3)];
     match vec {
         [box ref _a, _, _] => {
-        //~^ NOTE borrow of `vec[_]` occurs here
+        //~^ NOTE `vec[_]` is borrowed here
             vec[0] = Box::new(4); //~ ERROR cannot assign
-            //~^ NOTE assignment to borrowed `vec[_]` occurs here
+            //~^ NOTE `vec[_]` is assigned to here
             _a.use_ref();
             //~^ NOTE borrow later used here
         }
@@ -19,9 +19,9 @@ fn b() {
     let vec: &mut [Box<isize>] = &mut vec;
     match vec {
         &mut [ref _b @ ..] => {
-        //~^ borrow of `vec[_]` occurs here
+        //~^ `vec[_]` is borrowed here
             vec[0] = Box::new(4); //~ ERROR cannot assign
-            //~^ NOTE assignment to borrowed `vec[_]` occurs here
+            //~^ NOTE `vec[_]` is assigned to here
             _b.use_ref();
             //~^ NOTE borrow later used here
         }
diff --git a/tests/ui/borrowck/borrowck-vec-pattern-nesting.stderr b/tests/ui/borrowck/borrowck-vec-pattern-nesting.stderr
index 0dc5e64e4ff..70b9e4f4433 100644
--- a/tests/ui/borrowck/borrowck-vec-pattern-nesting.stderr
+++ b/tests/ui/borrowck/borrowck-vec-pattern-nesting.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `vec[_]` because it is borrowed
   --> $DIR/borrowck-vec-pattern-nesting.rs:9:13
    |
 LL |         [box ref _a, _, _] => {
-   |              ------ borrow of `vec[_]` occurs here
+   |              ------ `vec[_]` is borrowed here
 LL |
 LL |             vec[0] = Box::new(4);
-   |             ^^^^^^ assignment to borrowed `vec[_]` occurs here
+   |             ^^^^^^ `vec[_]` is assigned to here but it was already borrowed
 LL |
 LL |             _a.use_ref();
    |             ------------ borrow later used here
@@ -14,10 +14,10 @@ error[E0506]: cannot assign to `vec[_]` because it is borrowed
   --> $DIR/borrowck-vec-pattern-nesting.rs:23:13
    |
 LL |         &mut [ref _b @ ..] => {
-   |               ------ borrow of `vec[_]` occurs here
+   |               ------ `vec[_]` is borrowed here
 LL |
 LL |             vec[0] = Box::new(4);
-   |             ^^^^^^ assignment to borrowed `vec[_]` occurs here
+   |             ^^^^^^ `vec[_]` is assigned to here but it was already borrowed
 LL |
 LL |             _b.use_ref();
    |             ------------ borrow later used here
diff --git a/tests/ui/borrowck/issue-25793.stderr b/tests/ui/borrowck/issue-25793.stderr
index da3412f112d..27dab53e48f 100644
--- a/tests/ui/borrowck/issue-25793.stderr
+++ b/tests/ui/borrowck/issue-25793.stderr
@@ -5,7 +5,7 @@ LL |         $this.width.unwrap()
    |         ^^^^^^^^^^^ use of borrowed `*self`
 ...
 LL |         let r = &mut *self;
-   |                 ---------- borrow of `*self` occurs here
+   |                 ---------- `*self` is borrowed here
 LL |         r.get_size(width!(self))
    |           -------- ------------ in this macro invocation
    |           |
diff --git a/tests/ui/borrowck/issue-52713-bug.stderr b/tests/ui/borrowck/issue-52713-bug.stderr
index 4abb6fb2c71..3f7715645e6 100644
--- a/tests/ui/borrowck/issue-52713-bug.stderr
+++ b/tests/ui/borrowck/issue-52713-bug.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/issue-52713-bug.rs:12:5
    |
 LL |     let y = &x;
-   |             -- borrow of `x` occurs here
+   |             -- `x` is borrowed here
 ...
 LL |     x += 1;
-   |     ^^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^^ `x` is assigned to here but it was already borrowed
 LL |     println!("{}", y);
    |                    - borrow later used here
 
diff --git a/tests/ui/borrowck/issue-58776-borrowck-scans-children.stderr b/tests/ui/borrowck/issue-58776-borrowck-scans-children.stderr
index 57803247ba8..0870b423769 100644
--- a/tests/ui/borrowck/issue-58776-borrowck-scans-children.stderr
+++ b/tests/ui/borrowck/issue-58776-borrowck-scans-children.stderr
@@ -4,10 +4,10 @@ error[E0506]: cannot assign to `greeting` because it is borrowed
 LL |     let res = (|| (|| &greeting)())();
    |                --      -------- borrow occurs due to use in closure
    |                |
-   |                borrow of `greeting` occurs here
+   |                `greeting` is borrowed here
 LL |
 LL |     greeting = "DEALLOCATED".to_string();
-   |     ^^^^^^^^ assignment to borrowed `greeting` occurs here
+   |     ^^^^^^^^ `greeting` is assigned to here but it was already borrowed
 ...
 LL |     println!("thread result: {:?}", res);
    |                                     --- borrow later used here
diff --git a/tests/ui/borrowck/issue-81365-1.stderr b/tests/ui/borrowck/issue-81365-1.stderr
index d79394834dc..0d803b0427a 100644
--- a/tests/ui/borrowck/issue-81365-1.stderr
+++ b/tests/ui/borrowck/issue-81365-1.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-1.rs:21:9
    |
 LL |         let first = &self.target_field;
-   |                      ---- borrow of `self.container_field` occurs here
+   |                      ---- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-10.stderr b/tests/ui/borrowck/issue-81365-10.stderr
index 27123ef2be1..d0986e9f922 100644
--- a/tests/ui/borrowck/issue-81365-10.stderr
+++ b/tests/ui/borrowck/issue-81365-10.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-10.rs:21:9
    |
 LL |         let first = &self.deref().target_field;
-   |                      ------------ borrow of `self.container_field` occurs here
+   |                      ------------ `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
 
diff --git a/tests/ui/borrowck/issue-81365-11.stderr b/tests/ui/borrowck/issue-81365-11.stderr
index 0770c136632..5f7e86f11dc 100644
--- a/tests/ui/borrowck/issue-81365-11.stderr
+++ b/tests/ui/borrowck/issue-81365-11.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-11.rs:27:9
    |
 LL |         let first = &mut self.target_field;
-   |                          ---- borrow of `self.container_field` occurs here
+   |                          ---- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
 
diff --git a/tests/ui/borrowck/issue-81365-2.stderr b/tests/ui/borrowck/issue-81365-2.stderr
index 764eaaa7cc7..d9aeaf15f20 100644
--- a/tests/ui/borrowck/issue-81365-2.stderr
+++ b/tests/ui/borrowck/issue-81365-2.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container.container_field` because it is bo
   --> $DIR/issue-81365-2.rs:25:9
    |
 LL |         let first = &self.container.target_field;
-   |                      -------------- borrow of `self.container.container_field` occurs here
+   |                      -------------- `self.container.container_field` is borrowed here
 LL |         self.container.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-3.stderr b/tests/ui/borrowck/issue-81365-3.stderr
index 9447174fd21..0c0d1994baf 100644
--- a/tests/ui/borrowck/issue-81365-3.stderr
+++ b/tests/ui/borrowck/issue-81365-3.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container.container_field` because it is bo
   --> $DIR/issue-81365-3.rs:32:9
    |
 LL |         let first = &self.target_field;
-   |                      ---- borrow of `self.container.container_field` occurs here
+   |                      ---- `self.container.container_field` is borrowed here
 LL |         self.container.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-4.stderr b/tests/ui/borrowck/issue-81365-4.stderr
index 0ab3fa92706..98093daa945 100644
--- a/tests/ui/borrowck/issue-81365-4.stderr
+++ b/tests/ui/borrowck/issue-81365-4.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.outer_field` because it is borrowed
   --> $DIR/issue-81365-4.rs:33:9
    |
 LL |         let first = &self.target_field;
-   |                      ---- borrow of `self.outer_field` occurs here
+   |                      ---- `self.outer_field` is borrowed here
 LL |         self.outer_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.outer_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^ `self.outer_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-5.stderr b/tests/ui/borrowck/issue-81365-5.stderr
index 20ff229ffe7..c00e48288ba 100644
--- a/tests/ui/borrowck/issue-81365-5.stderr
+++ b/tests/ui/borrowck/issue-81365-5.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-5.rs:28:9
    |
 LL |         let first = self.get();
-   |                     ---------- borrow of `self.container_field` occurs here
+   |                     ---------- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-6.stderr b/tests/ui/borrowck/issue-81365-6.stderr
index 575aed73b46..e61dc95ecc8 100644
--- a/tests/ui/borrowck/issue-81365-6.stderr
+++ b/tests/ui/borrowck/issue-81365-6.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-6.rs:18:9
    |
 LL |         let first = &self[0];
-   |                      ---- borrow of `self.container_field` occurs here
+   |                      ---- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-7.stderr b/tests/ui/borrowck/issue-81365-7.stderr
index 52d2d9e75a9..0565127e387 100644
--- a/tests/ui/borrowck/issue-81365-7.stderr
+++ b/tests/ui/borrowck/issue-81365-7.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `c.container_field` because it is borrowed
   --> $DIR/issue-81365-7.rs:20:5
    |
 LL |     let first = &c.target_field;
-   |                  - borrow of `c.container_field` occurs here
+   |                  - `c.container_field` is borrowed here
 LL |     c.container_field = true;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `c.container_field` occurs here
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ `c.container_field` is assigned to here but it was already borrowed
 LL |     first;
    |     ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-8.stderr b/tests/ui/borrowck/issue-81365-8.stderr
index fd83e10a295..0ca732ff2ae 100644
--- a/tests/ui/borrowck/issue-81365-8.stderr
+++ b/tests/ui/borrowck/issue-81365-8.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-8.rs:21:9
    |
 LL |         let first = &(*self).target_field;
-   |                      ------- borrow of `self.container_field` occurs here
+   |                      ------- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
    |
diff --git a/tests/ui/borrowck/issue-81365-9.stderr b/tests/ui/borrowck/issue-81365-9.stderr
index c7d48214fd4..4d305268a0b 100644
--- a/tests/ui/borrowck/issue-81365-9.stderr
+++ b/tests/ui/borrowck/issue-81365-9.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `self.container_field` because it is borrowed
   --> $DIR/issue-81365-9.rs:21:9
    |
 LL |         let first = &Deref::deref(self).target_field;
-   |                                   ---- borrow of `self.container_field` occurs here
+   |                                   ---- `self.container_field` is borrowed here
 LL |         self.container_field = true;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `self.container_field` occurs here
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self.container_field` is assigned to here but it was already borrowed
 LL |         first;
    |         ----- borrow later used here
 
diff --git a/tests/ui/borrowck/two-phase-allow-access-during-reservation.nll_target.stderr b/tests/ui/borrowck/two-phase-allow-access-during-reservation.nll_target.stderr
index a57ceb84739..1356c80493c 100644
--- a/tests/ui/borrowck/two-phase-allow-access-during-reservation.nll_target.stderr
+++ b/tests/ui/borrowck/two-phase-allow-access-during-reservation.nll_target.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `i` because it was mutably borrowed
   --> $DIR/two-phase-allow-access-during-reservation.rs:26:19
    |
 LL |     /*1*/ let p = &mut i; // (reservation of `i` starts here)
-   |                   ------ borrow of `i` occurs here
+   |                   ------ `i` is borrowed here
 LL |
 LL |     /*2*/ let j = i;      // OK: `i` is only reserved here
    |                   ^ use of borrowed `i`
@@ -14,7 +14,7 @@ error[E0503]: cannot use `i` because it was mutably borrowed
   --> $DIR/two-phase-allow-access-during-reservation.rs:31:19
    |
 LL |     /*1*/ let p = &mut i; // (reservation of `i` starts here)
-   |                   ------ borrow of `i` occurs here
+   |                   ------ `i` is borrowed here
 ...
 LL |     /*4*/ let k = i;
    |                   ^ use of borrowed `i`
diff --git a/tests/ui/borrowck/two-phase-surprise-no-conflict.stderr b/tests/ui/borrowck/two-phase-surprise-no-conflict.stderr
index 5a240d90011..e75094d4f13 100644
--- a/tests/ui/borrowck/two-phase-surprise-no-conflict.stderr
+++ b/tests/ui/borrowck/two-phase-surprise-no-conflict.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `self.cx` because it was mutably borrowed
   --> $DIR/two-phase-surprise-no-conflict.rs:21:23
    |
 LL |         let _mut_borrow = &mut *self;
-   |                           ---------- borrow of `*self` occurs here
+   |                           ---------- `*self` is borrowed here
 LL |         let _access = self.cx;
    |                       ^^^^^^^ use of borrowed `*self`
 LL |
diff --git a/tests/ui/box/leak-alloc.stderr b/tests/ui/box/leak-alloc.stderr
index e8a6ad0995a..5140b58934a 100644
--- a/tests/ui/box/leak-alloc.stderr
+++ b/tests/ui/box/leak-alloc.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `alloc` because it is borrowed
   --> $DIR/leak-alloc.rs:26:10
    |
+LL |     let alloc = Alloc {};
+   |         ----- binding `alloc` declared here
 LL |     let boxed = Box::new_in(10, alloc.by_ref());
    |                                 -------------- borrow of `alloc` occurs here
 LL |     let theref = Box::leak(boxed);
diff --git a/tests/ui/btreemap/btreemap_dropck.stderr b/tests/ui/btreemap/btreemap_dropck.stderr
index e953e7ae82b..d405e465aae 100644
--- a/tests/ui/btreemap/btreemap_dropck.stderr
+++ b/tests/ui/btreemap/btreemap_dropck.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `s` because it is borrowed
   --> $DIR/btreemap_dropck.rs:15:10
    |
+LL |     let s = String::from("Hello World!");
+   |         - binding `s` declared here
 LL |     let _map = BTreeMap::from_iter([((), PrintOnDrop(&s))]);
    |                                                      -- borrow of `s` occurs here
 LL |     drop(s);
diff --git a/tests/ui/c-variadic/variadic-ffi-4.stderr b/tests/ui/c-variadic/variadic-ffi-4.stderr
index 6f8e53298ac..c9d90d73dea 100644
--- a/tests/ui/c-variadic/variadic-ffi-4.stderr
+++ b/tests/ui/c-variadic/variadic-ffi-4.stderr
@@ -107,7 +107,9 @@ error[E0597]: `ap1` does not live long enough
   --> $DIR/variadic-ffi-4.rs:28:11
    |
 LL | pub unsafe extern "C" fn no_escape4(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) {
-   |                                                        - let's call the lifetime of this reference `'3`
+   |                                                        -                ------- binding `ap1` declared here
+   |                                                        |
+   |                                                        let's call the lifetime of this reference `'3`
 LL |     ap0 = &mut ap1;
    |     ------^^^^^^^^
    |     |     |
diff --git a/tests/ui/closures/2229_closure_analysis/diagnostics/arrays.stderr b/tests/ui/closures/2229_closure_analysis/diagnostics/arrays.stderr
index 4f41060dc98..9e5200ef34b 100644
--- a/tests/ui/closures/2229_closure_analysis/diagnostics/arrays.stderr
+++ b/tests/ui/closures/2229_closure_analysis/diagnostics/arrays.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `arr` because it was mutably borrowed
   --> $DIR/arrays.rs:14:5
    |
 LL |     let mut c = || {
-   |                 -- borrow of `arr` occurs here
+   |                 -- `arr` is borrowed here
 LL |         arr[0] += 10;
    |         --- borrow occurs due to use of `arr` in closure
 ...
@@ -16,7 +16,7 @@ error[E0503]: cannot use `arr[_]` because it was mutably borrowed
   --> $DIR/arrays.rs:14:5
    |
 LL |     let mut c = || {
-   |                 -- borrow of `arr` occurs here
+   |                 -- `arr` is borrowed here
 LL |         arr[0] += 10;
    |         --- borrow occurs due to use of `arr` in closure
 ...
@@ -30,12 +30,12 @@ error[E0506]: cannot assign to `arr[_]` because it is borrowed
   --> $DIR/arrays.rs:29:5
    |
 LL |     let c = || {
-   |             -- borrow of `arr[_]` occurs here
+   |             -- `arr[_]` is borrowed here
 LL |         println!("{:#?}", &arr[3..4]);
    |                            --- borrow occurs due to use in closure
 ...
 LL |     arr[1] += 10;
-   |     ^^^^^^^^^^^^ assignment to borrowed `arr[_]` occurs here
+   |     ^^^^^^^^^^^^ `arr[_]` is assigned to here but it was already borrowed
 LL |
 LL |     c();
    |     - borrow later used here
@@ -44,12 +44,12 @@ error[E0506]: cannot assign to `arr[_]` because it is borrowed
   --> $DIR/arrays.rs:43:5
    |
 LL |     let c = || {
-   |             -- borrow of `arr[_]` occurs here
+   |             -- `arr[_]` is borrowed here
 LL |         println!("{}", arr[3]);
    |                        --- borrow occurs due to use in closure
 ...
 LL |     arr[1] += 10;
-   |     ^^^^^^^^^^^^ assignment to borrowed `arr[_]` occurs here
+   |     ^^^^^^^^^^^^ `arr[_]` is assigned to here but it was already borrowed
 LL |
 LL |     c();
    |     - borrow later used here
@@ -58,7 +58,7 @@ error[E0503]: cannot use `arr` because it was mutably borrowed
   --> $DIR/arrays.rs:57:20
    |
 LL |     let mut c = || {
-   |                 -- borrow of `arr` occurs here
+   |                 -- `arr` is borrowed here
 LL |         arr[1] += 10;
    |         --- borrow occurs due to use of `arr` in closure
 ...
diff --git a/tests/ui/closures/2229_closure_analysis/diagnostics/box.stderr b/tests/ui/closures/2229_closure_analysis/diagnostics/box.stderr
index f8b17875235..2e3259e6405 100644
--- a/tests/ui/closures/2229_closure_analysis/diagnostics/box.stderr
+++ b/tests/ui/closures/2229_closure_analysis/diagnostics/box.stderr
@@ -2,12 +2,12 @@ error[E0506]: cannot assign to `e.0.0.m.x` because it is borrowed
   --> $DIR/box.rs:21:5
    |
 LL |     let mut c = || {
-   |                 -- borrow of `e.0.0.m.x` occurs here
+   |                 -- `e.0.0.m.x` is borrowed here
 LL |         e.0.0.m.x = format!("not-x");
    |         --------- borrow occurs due to use in closure
 ...
 LL |     e.0.0.m.x = format!("not-x");
-   |     ^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here
+   |     ^^^^^^^^^ `e.0.0.m.x` is assigned to here but it was already borrowed
 LL |
 LL |     c();
    |     - borrow later used here
@@ -32,12 +32,12 @@ error[E0506]: cannot assign to `e.0.0.m.x` because it is borrowed
   --> $DIR/box.rs:55:5
    |
 LL |     let c = || {
-   |             -- borrow of `e.0.0.m.x` occurs here
+   |             -- `e.0.0.m.x` is borrowed here
 LL |         println!("{}", e.0.0.m.x);
    |                        --------- borrow occurs due to use in closure
 ...
 LL |     e.0.0.m.x = format!("not-x");
-   |     ^^^^^^^^^ assignment to borrowed `e.0.0.m.x` occurs here
+   |     ^^^^^^^^^ `e.0.0.m.x` is assigned to here but it was already borrowed
 LL |
 LL |     c();
    |     - borrow later used here
diff --git a/tests/ui/closures/2229_closure_analysis/diagnostics/union.rs b/tests/ui/closures/2229_closure_analysis/diagnostics/union.rs
index 46b54846e32..695337ea82c 100644
--- a/tests/ui/closures/2229_closure_analysis/diagnostics/union.rs
+++ b/tests/ui/closures/2229_closure_analysis/diagnostics/union.rs
@@ -11,7 +11,7 @@ union A {
 fn main() {
     let mut a = A { y: 1 };
     let mut c = || {
-    //~^ borrow of `a.y` occurs here
+    //~^ `a.y` is borrowed here
         let _ = unsafe { &a.y };
         let _ = &mut a;
         //~^ borrow occurs due to use in closure
@@ -19,7 +19,7 @@ fn main() {
     };
     a.y = 1;
     //~^ cannot assign to `a.y` because it is borrowed [E0506]
-    //~| assignment to borrowed `a.y` occurs here
+    //~| `a.y` is assigned to here
     c();
     //~^ borrow later used here
 }
diff --git a/tests/ui/closures/2229_closure_analysis/diagnostics/union.stderr b/tests/ui/closures/2229_closure_analysis/diagnostics/union.stderr
index 7c34e2336c8..17834e61236 100644
--- a/tests/ui/closures/2229_closure_analysis/diagnostics/union.stderr
+++ b/tests/ui/closures/2229_closure_analysis/diagnostics/union.stderr
@@ -2,13 +2,13 @@ error[E0506]: cannot assign to `a.y` because it is borrowed
   --> $DIR/union.rs:20:5
    |
 LL |     let mut c = || {
-   |                 -- borrow of `a.y` occurs here
+   |                 -- `a.y` is borrowed here
 ...
 LL |         let _ = &mut a;
    |                      - borrow occurs due to use in closure
 ...
 LL |     a.y = 1;
-   |     ^^^^^^^ assignment to borrowed `a.y` occurs here
+   |     ^^^^^^^ `a.y` is assigned to here but it was already borrowed
 ...
 LL |     c();
    |     - borrow later used here
diff --git a/tests/ui/coercion/coerce-overloaded-autoderef-fail.stderr b/tests/ui/coercion/coerce-overloaded-autoderef-fail.stderr
index d067c3b3a18..d412b8b08b7 100644
--- a/tests/ui/coercion/coerce-overloaded-autoderef-fail.stderr
+++ b/tests/ui/coercion/coerce-overloaded-autoderef-fail.stderr
@@ -13,10 +13,10 @@ error[E0506]: cannot assign to `**x` because it is borrowed
   --> $DIR/coerce-overloaded-autoderef-fail.rs:17:5
    |
 LL |     let y = borrow(x);
-   |                    - borrow of `**x` occurs here
+   |                    - `**x` is borrowed here
 LL |     let z = borrow(x);
 LL |     **x += 1;
-   |     ^^^^^^^^ assignment to borrowed `**x` occurs here
+   |     ^^^^^^^^ `**x` is assigned to here but it was already borrowed
 LL |
 LL |     drop((y, z));
    |           - borrow later used here
diff --git a/tests/ui/const-generics/bad-const-generic-exprs.rs b/tests/ui/const-generics/bad-const-generic-exprs.rs
index ca91643edf7..423752ca25e 100644
--- a/tests/ui/const-generics/bad-const-generic-exprs.rs
+++ b/tests/ui/const-generics/bad-const-generic-exprs.rs
@@ -13,10 +13,34 @@ fn main() {
     let _: Wow<A.0>;
     //~^ ERROR expected one of
     //~| HELP expressions must be enclosed in braces to be used as const generic arguments
-
-    // FIXME(compiler-errors): This one is still unsatisfying,
-    // and probably a case I could see someone typing by accident..
+    let _: Wow<[]>;
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
     let _: Wow<[12]>;
-    //~^ ERROR expected type, found
-    //~| ERROR type provided when a constant was expected
+    //~^ ERROR expected type
+    //~| ERROR invalid const generic expression
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<[0, 1, 3]>;
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<[0xff; 8]>;
+    //~^ ERROR expected type
+    //~| ERROR invalid const generic expression
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<[1, 2]>; // Regression test for issue #81698.
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<&0>;
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<("", 0)>;
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    let _: Wow<(1 + 2) * 3>;
+    //~^ ERROR expected type
+    //~| HELP expressions must be enclosed in braces to be used as const generic arguments
+    // FIXME(fmease): This one is pretty bad.
+    let _: Wow<!0>;
+    //~^ ERROR expected one of
+    //~| HELP you might have meant to end the type parameters here
 }
diff --git a/tests/ui/const-generics/bad-const-generic-exprs.stderr b/tests/ui/const-generics/bad-const-generic-exprs.stderr
index 24668b08b8a..17a63a96fe4 100644
--- a/tests/ui/const-generics/bad-const-generic-exprs.stderr
+++ b/tests/ui/const-generics/bad-const-generic-exprs.stderr
@@ -42,18 +42,118 @@ help: expressions must be enclosed in braces to be used as const generic argumen
 LL |     let _: Wow<{ A.0 }>;
    |                +     +
 
+error: expected type, found `]`
+  --> $DIR/bad-const-generic-exprs.rs:16:17
+   |
+LL |     let _: Wow<[]>;
+   |                 ^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ [] }>;
+   |                +    +
+
 error: expected type, found `12`
   --> $DIR/bad-const-generic-exprs.rs:19:17
    |
 LL |     let _: Wow<[12]>;
    |                 ^^ expected type
 
-error[E0747]: type provided when a constant was expected
+error: invalid const generic expression
   --> $DIR/bad-const-generic-exprs.rs:19:16
    |
 LL |     let _: Wow<[12]>;
    |                ^^^^
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ [12] }>;
+   |                +      +
+
+error: expected type, found `0`
+  --> $DIR/bad-const-generic-exprs.rs:23:17
+   |
+LL |     let _: Wow<[0, 1, 3]>;
+   |                 ^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ [0, 1, 3] }>;
+   |                +           +
+
+error: expected type, found `0xff`
+  --> $DIR/bad-const-generic-exprs.rs:26:17
+   |
+LL |     let _: Wow<[0xff; 8]>;
+   |                 ^^^^ expected type
+
+error: invalid const generic expression
+  --> $DIR/bad-const-generic-exprs.rs:26:16
+   |
+LL |     let _: Wow<[0xff; 8]>;
+   |                ^^^^^^^^^
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ [0xff; 8] }>;
+   |                +           +
+
+error: expected type, found `1`
+  --> $DIR/bad-const-generic-exprs.rs:30:17
+   |
+LL |     let _: Wow<[1, 2]>; // Regression test for issue #81698.
+   |                 ^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ [1, 2] }>; // Regression test for issue #81698.
+   |                +        +
+
+error: expected type, found `0`
+  --> $DIR/bad-const-generic-exprs.rs:33:17
+   |
+LL |     let _: Wow<&0>;
+   |                 ^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ &0 }>;
+   |                +    +
+
+error: expected type, found `""`
+  --> $DIR/bad-const-generic-exprs.rs:36:17
+   |
+LL |     let _: Wow<("", 0)>;
+   |                 ^^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ ("", 0) }>;
+   |                +         +
+
+error: expected type, found `1`
+  --> $DIR/bad-const-generic-exprs.rs:39:17
+   |
+LL |     let _: Wow<(1 + 2) * 3>;
+   |                 ^ expected type
+   |
+help: expressions must be enclosed in braces to be used as const generic arguments
+   |
+LL |     let _: Wow<{ (1 + 2) * 3 }>;
+   |                +             +
+
+error: expected one of `,` or `>`, found `0`
+  --> $DIR/bad-const-generic-exprs.rs:43:17
+   |
+LL |     let _: Wow<!0>;
+   |         -       ^ expected one of `,` or `>`
+   |         |
+   |         while parsing the type for `_`
+   |
+help: you might have meant to end the type parameters here
+   |
+LL |     let _: Wow<!>0>;
+   |                 +
 
-error: aborting due to 6 previous errors
+error: aborting due to 15 previous errors
 
-For more information about this error, try `rustc --explain E0747`.
diff --git a/tests/ui/const-generics/min_const_generics/macro-fail.stderr b/tests/ui/const-generics/min_const_generics/macro-fail.stderr
index 9f73b91aabe..cc629fd920f 100644
--- a/tests/ui/const-generics/min_const_generics/macro-fail.stderr
+++ b/tests/ui/const-generics/min_const_generics/macro-fail.stderr
@@ -8,7 +8,7 @@ LL | fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
    |                                 in this macro invocation
 ...
 LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected type
+   |                           ^ expected type
    |
    = note: this error originates in the macro `gimme_a_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
@@ -22,26 +22,21 @@ LL |   Example::<gimme_a_const!(marker)>
    |             in this macro invocation
 ...
 LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected type
+   |                           ^ expected type
    |
    = note: this error originates in the macro `gimme_a_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected type, found `{`
   --> $DIR/macro-fail.rs:4:10
    |
-LL |     () => {{
-   |  __________^
-LL | |
-LL | |     const X: usize = 1337;
-LL | |     X
-LL | |   }}
-   | |___^ expected type
+LL |   () => {{
+   |          ^ expected type
 ...
-LL |     let _fail = Example::<external_macro!()>;
-   |                           -----------------
-   |                           |
-   |                           this macro call doesn't expand to a type
-   |                           in this macro invocation
+LL |   let _fail = Example::<external_macro!()>;
+   |                         -----------------
+   |                         |
+   |                         this macro call doesn't expand to a type
+   |                         in this macro invocation
    |
    = note: this error originates in the macro `external_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/tests/ui/consts/const-eval/infinite_loop.stderr b/tests/ui/consts/const-eval/infinite_loop.stderr
index 8b58cb279f3..f30bfaf3f95 100644
--- a/tests/ui/consts/const-eval/infinite_loop.stderr
+++ b/tests/ui/consts/const-eval/infinite_loop.stderr
@@ -1,8 +1,11 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/infinite_loop.rs:6:15
+  --> $DIR/infinite_loop.rs:6:9
    |
-LL |         while n != 0 {
-   |               ^^^^^^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+LL | /         while n != 0 {
+LL | |
+LL | |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
+LL | |         }
+   | |_________^ exceeded interpreter step limit (see `#[const_eval_limit]`)
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/const-eval/issue-52475.rs b/tests/ui/consts/const-eval/issue-52475.rs
index ce65407bbab..307c1a66834 100644
--- a/tests/ui/consts/const-eval/issue-52475.rs
+++ b/tests/ui/consts/const-eval/issue-52475.rs
@@ -2,8 +2,8 @@ fn main() {
     let _ = [(); {
         let mut x = &0;
         let mut n = 0;
-        while n < 5 {
-            n = (n + 1) % 5; //~ ERROR evaluation of constant value failed
+        while n < 5 { //~ ERROR evaluation of constant value failed [E0080]
+            n = (n + 1) % 5;
             x = &0; // Materialize a new AllocId
         }
         0
diff --git a/tests/ui/consts/const-eval/issue-52475.stderr b/tests/ui/consts/const-eval/issue-52475.stderr
index 8536ff02c6d..3aa6bd277dd 100644
--- a/tests/ui/consts/const-eval/issue-52475.stderr
+++ b/tests/ui/consts/const-eval/issue-52475.stderr
@@ -1,8 +1,11 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/issue-52475.rs:6:17
+  --> $DIR/issue-52475.rs:5:9
    |
-LL |             n = (n + 1) % 5;
-   |                 ^^^^^^^^^^^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+LL | /         while n < 5 {
+LL | |             n = (n + 1) % 5;
+LL | |             x = &0; // Materialize a new AllocId
+LL | |         }
+   | |_________^ exceeded interpreter step limit (see `#[const_eval_limit]`)
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.rs b/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.rs
new file mode 100644
index 00000000000..c59596238e1
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.rs
@@ -0,0 +1,36 @@
+// check-fail
+// compile-flags: -Z tiny-const-eval-limit
+
+const fn foo() {}
+
+const fn call_foo() -> u32 {
+    foo();
+    foo();
+    foo();
+    foo();
+    foo();
+
+    foo();
+    foo();
+    foo();
+    foo();
+    foo();
+
+    foo();
+    foo();
+    foo();
+    foo();
+    foo();
+
+    foo();
+    foo();
+    foo();
+    foo(); //~ ERROR evaluation of constant value failed [E0080]
+    0
+}
+
+const X: u32 = call_foo();
+
+fn main() {
+    println!("{X}");
+}
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.stderr b/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.stderr
new file mode 100644
index 00000000000..ed70975af34
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-fn-call.stderr
@@ -0,0 +1,20 @@
+error[E0080]: evaluation of constant value failed
+  --> $DIR/ctfe-fn-call.rs:28:5
+   |
+LL |     foo();
+   |     ^^^^^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+   |
+note: inside `call_foo`
+  --> $DIR/ctfe-fn-call.rs:28:5
+   |
+LL |     foo();
+   |     ^^^^^
+note: inside `X`
+  --> $DIR/ctfe-fn-call.rs:32:16
+   |
+LL | const X: u32 = call_foo();
+   |                ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.rs b/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.rs
new file mode 100644
index 00000000000..c10b8d83791
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.rs
@@ -0,0 +1,19 @@
+// check-fail
+// compile-flags: -Z tiny-const-eval-limit
+
+const fn labelled_loop(n: u32) -> u32 {
+    let mut i = 0;
+    'mylabel: loop { //~ ERROR evaluation of constant value failed [E0080]
+        if i > n {
+            break 'mylabel
+        }
+        i += 1;
+    }
+    0
+}
+
+const X: u32 = labelled_loop(19);
+
+fn main() {
+    println!("{X}");
+}
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.stderr b/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.stderr
new file mode 100644
index 00000000000..d9404edd5b1
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-labelled-loop.stderr
@@ -0,0 +1,30 @@
+error[E0080]: evaluation of constant value failed
+  --> $DIR/ctfe-labelled-loop.rs:6:5
+   |
+LL | /     'mylabel: loop {
+LL | |         if i > n {
+LL | |             break 'mylabel
+LL | |         }
+LL | |         i += 1;
+LL | |     }
+   | |_____^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+   |
+note: inside `labelled_loop`
+  --> $DIR/ctfe-labelled-loop.rs:6:5
+   |
+LL | /     'mylabel: loop {
+LL | |         if i > n {
+LL | |             break 'mylabel
+LL | |         }
+LL | |         i += 1;
+LL | |     }
+   | |_____^
+note: inside `X`
+  --> $DIR/ctfe-labelled-loop.rs:15:16
+   |
+LL | const X: u32 = labelled_loop(19);
+   |                ^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.rs b/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.rs
new file mode 100644
index 00000000000..80ff835f3e8
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.rs
@@ -0,0 +1,16 @@
+// check-fail
+// compile-flags: -Z tiny-const-eval-limit
+
+const fn recurse(n: u32) -> u32 {
+    if n == 0 {
+        n
+    } else {
+        recurse(n - 1) //~ ERROR evaluation of constant value failed [E0080]
+    }
+}
+
+const X: u32 = recurse(19);
+
+fn main() {
+    println!("{X}");
+}
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.stderr b/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.stderr
new file mode 100644
index 00000000000..ed9a3111942
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-recursion.stderr
@@ -0,0 +1,25 @@
+error[E0080]: evaluation of constant value failed
+  --> $DIR/ctfe-recursion.rs:8:9
+   |
+LL |         recurse(n - 1)
+   |         ^^^^^^^^^^^^^^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+   |
+note: inside `recurse`
+  --> $DIR/ctfe-recursion.rs:8:9
+   |
+LL |         recurse(n - 1)
+   |         ^^^^^^^^^^^^^^
+note: [... 18 additional calls inside `recurse` ...]
+  --> $DIR/ctfe-recursion.rs:8:9
+   |
+LL |         recurse(n - 1)
+   |         ^^^^^^^^^^^^^^
+note: inside `X`
+  --> $DIR/ctfe-recursion.rs:12:16
+   |
+LL | const X: u32 = recurse(19);
+   |                ^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.rs b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.rs
new file mode 100644
index 00000000000..ca0eec93c5d
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.rs
@@ -0,0 +1,15 @@
+// check-fail
+// compile-flags: -Z tiny-const-eval-limit
+const fn simple_loop(n: u32) -> u32 {
+    let mut index = 0;
+    while index < n { //~ ERROR evaluation of constant value failed [E0080]
+        index = index + 1;
+    }
+    0
+}
+
+const X: u32 = simple_loop(19);
+
+fn main() {
+    println!("{X}");
+}
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.stderr b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.stderr
new file mode 100644
index 00000000000..83ff275de70
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.stderr
@@ -0,0 +1,24 @@
+error[E0080]: evaluation of constant value failed
+  --> $DIR/ctfe-simple-loop.rs:5:5
+   |
+LL | /     while index < n {
+LL | |         index = index + 1;
+LL | |     }
+   | |_____^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+   |
+note: inside `simple_loop`
+  --> $DIR/ctfe-simple-loop.rs:5:5
+   |
+LL | /     while index < n {
+LL | |         index = index + 1;
+LL | |     }
+   | |_____^
+note: inside `X`
+  --> $DIR/ctfe-simple-loop.rs:11:16
+   |
+LL | const X: u32 = simple_loop(19);
+   |                ^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/stable-metric/dominators-edge-case.rs b/tests/ui/consts/const-eval/stable-metric/dominators-edge-case.rs
new file mode 100644
index 00000000000..0b0f361809f
--- /dev/null
+++ b/tests/ui/consts/const-eval/stable-metric/dominators-edge-case.rs
@@ -0,0 +1,19 @@
+// check-pass
+//
+// Exercising an edge case which was found during Stage 2 compilation.
+// Compilation would fail for this code when running the `CtfeLimit`
+// MirPass (specifically when looking up the dominators).
+#![crate_type="lib"]
+
+const DUMMY: Expr = Expr::Path(ExprPath {
+    attrs: Vec::new(),
+    path: Vec::new(),
+});
+
+pub enum Expr {
+    Path(ExprPath),
+}
+pub struct ExprPath {
+    pub attrs: Vec<()>,
+    pub path: Vec<()>,
+}
diff --git a/tests/ui/consts/const_limit/const_eval_limit_reached.stderr b/tests/ui/consts/const_limit/const_eval_limit_reached.stderr
index 850aebdfb2a..a8e8ae9bb08 100644
--- a/tests/ui/consts/const_limit/const_eval_limit_reached.stderr
+++ b/tests/ui/consts/const_limit/const_eval_limit_reached.stderr
@@ -1,8 +1,11 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/const_eval_limit_reached.rs:6:11
+  --> $DIR/const_eval_limit_reached.rs:6:5
    |
-LL |     while x != 1000 {
-   |           ^^^^^^^^^ exceeded interpreter step limit (see `#[const_eval_limit]`)
+LL | /     while x != 1000 {
+LL | |
+LL | |         x += 1;
+LL | |     }
+   | |_____^ exceeded interpreter step limit (see `#[const_eval_limit]`)
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/promote_const_let.stderr b/tests/ui/consts/promote_const_let.stderr
index 975a235a649..6e0349a4773 100644
--- a/tests/ui/consts/promote_const_let.stderr
+++ b/tests/ui/consts/promote_const_let.stderr
@@ -4,6 +4,7 @@ error[E0597]: `y` does not live long enough
 LL |     let x: &'static u32 = {
    |            ------------ type annotation requires that `y` is borrowed for `'static`
 LL |         let y = 42;
+   |             - binding `y` declared here
 LL |         &y
    |         ^^ borrowed value does not live long enough
 LL |     };
diff --git a/tests/ui/derives/deriving-with-repr-packed-2.rs b/tests/ui/derives/deriving-with-repr-packed-2.rs
new file mode 100644
index 00000000000..cbd7432fce4
--- /dev/null
+++ b/tests/ui/derives/deriving-with-repr-packed-2.rs
@@ -0,0 +1,22 @@
+#![deny(unaligned_references)]
+
+// Check that deriving certain builtin traits on certain packed structs cause
+// errors. To avoid potentially misaligned references, field copies must be
+// used, which involves adding `T: Copy` bounds.
+
+#[derive(Copy, Clone, Default, PartialEq, Eq)]
+#[repr(packed)]
+pub struct Foo<T>(T, T, T);
+
+struct NonCopy;
+
+fn main() {
+    // This one is fine because `u32` impls `Copy`.
+    let x: Foo<u32> = Foo(1, 2, 3);
+    _ = x.clone();
+
+    // This one is an error because `NonCopy` doesn't impl `Copy`.
+    let x: Foo<NonCopy> = Foo(NonCopy, NonCopy, NonCopy);
+    _ = x.clone();
+    //~^ ERROR the method `clone` exists for struct `Foo<NonCopy>`, but its trait bounds were not satisfied
+}
diff --git a/tests/ui/derives/deriving-with-repr-packed-2.stderr b/tests/ui/derives/deriving-with-repr-packed-2.stderr
new file mode 100644
index 00000000000..83540739ee3
--- /dev/null
+++ b/tests/ui/derives/deriving-with-repr-packed-2.stderr
@@ -0,0 +1,33 @@
+error[E0599]: the method `clone` exists for struct `Foo<NonCopy>`, but its trait bounds were not satisfied
+  --> $DIR/deriving-with-repr-packed-2.rs:20:11
+   |
+LL | pub struct Foo<T>(T, T, T);
+   | -----------------
+   | |
+   | method `clone` not found for this struct
+   | doesn't satisfy `Foo<NonCopy>: Clone`
+LL |
+LL | struct NonCopy;
+   | --------------
+   | |
+   | doesn't satisfy `NonCopy: Clone`
+   | doesn't satisfy `NonCopy: Copy`
+...
+LL |     _ = x.clone();
+   |           ^^^^^ method cannot be called on `Foo<NonCopy>` due to unsatisfied trait bounds
+   |
+note: the following trait bounds were not satisfied:
+      `NonCopy: Clone`
+      `NonCopy: Copy`
+  --> $DIR/deriving-with-repr-packed-2.rs:7:16
+   |
+LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
+   |                ^^^^^ unsatisfied trait bound introduced in this `derive` macro
+help: consider annotating `NonCopy` with `#[derive(Clone, Copy)]`
+   |
+LL | #[derive(Clone, Copy)]
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0599`.
diff --git a/tests/ui/derives/deriving-with-repr-packed.rs b/tests/ui/derives/deriving-with-repr-packed.rs
index 3884e397764..eddf41f5553 100644
--- a/tests/ui/derives/deriving-with-repr-packed.rs
+++ b/tests/ui/derives/deriving-with-repr-packed.rs
@@ -1,45 +1,38 @@
 #![deny(unaligned_references)]
 
 // Check that deriving certain builtin traits on certain packed structs cause
-// errors. This happens when the derived trait would need to use a potentially
-// misaligned reference. But there are two cases that are allowed:
-// - If all the fields within the struct meet the required alignment: 1 for
-//   `repr(packed)`, or `N` for `repr(packed(N))`.
-// - If `Default` is the only trait derived, because it doesn't involve any
-//   references.
+// errors. To avoid potentially misaligned references, field copies must be
+// used, which involves adding `T: Copy` bounds.
 
 #[derive(Copy, Clone, Default, PartialEq, Eq)]
-//~^ ERROR `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-//~| hard error
-//~^^^ ERROR `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-//~| hard error
 #[repr(packed)]
 pub struct Foo<T>(T, T, T);
 
+// This one is fine because the fields all impl `Copy`.
 #[derive(Default, Hash)]
-//~^ ERROR `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-//~| hard error
 #[repr(packed)]
 pub struct Bar(u32, u32, u32);
 
-// This one is fine because the field alignment is 1.
-#[derive(Default, Hash)]
-#[repr(packed)]
-pub struct Bar2(u8, i8, bool);
-
-// This one is fine because the field alignment is 2, matching `packed(2)`.
-#[derive(Default, Hash)]
-#[repr(packed(2))]
-pub struct Bar3(u16, i16, bool);
-
 // This one is fine because it's not packed.
 #[derive(Debug, Default)]
 struct Y(usize);
 
+// This one has an error because `Y` doesn't impl `Copy`.
+// Note: there is room for improvement in the error message.
 #[derive(Debug, Default)]
-//~^ ERROR `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-//~| hard error
 #[repr(packed)]
 struct X(Y);
+//~^ ERROR cannot move out of `self` which is behind a shared reference
+
+// This is currently allowed, but will be phased out at some point. From
+// `zerovec` within icu4x-0.9.0.
+#[derive(Debug)]
+#[repr(packed)]
+struct FlexZeroSlice {
+    width: u8,
+    data: [u8],
+    //~^ WARNING byte slice in a packed struct that derives a built-in trait
+    //~^^ this was previously accepted
+}
 
 fn main() {}
diff --git a/tests/ui/derives/deriving-with-repr-packed.stderr b/tests/ui/derives/deriving-with-repr-packed.stderr
index 0ad800c3981..2cb2a696d97 100644
--- a/tests/ui/derives/deriving-with-repr-packed.stderr
+++ b/tests/ui/derives/deriving-with-repr-packed.stderr
@@ -1,111 +1,45 @@
-error: `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-  --> $DIR/deriving-with-repr-packed.rs:11:16
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-with-repr-packed.rs:33:5
    |
-LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                ^^^^^
+LL | #[derive(Debug)]
+   |          ----- in this derive macro expansion
+...
+LL |     data: [u8],
+   |     ^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-note: the lint level is defined here
-  --> $DIR/deriving-with-repr-packed.rs:1:9
-   |
-LL | #![deny(unaligned_references)]
-   |         ^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-  --> $DIR/deriving-with-repr-packed.rs:11:32
-   |
-LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                                ^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-  --> $DIR/deriving-with-repr-packed.rs:19:19
-   |
-LL | #[derive(Default, Hash)]
-   |                   ^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-  --> $DIR/deriving-with-repr-packed.rs:39:10
+error[E0507]: cannot move out of `self` which is behind a shared reference
+  --> $DIR/deriving-with-repr-packed.rs:24:10
    |
 LL | #[derive(Debug, Default)]
-   |          ^^^^^
+   |          ----- in this derive macro expansion
+LL | #[repr(packed)]
+LL | struct X(Y);
+   |          ^ move occurs because `self.0` has type `Y`, which does not implement the `Copy` trait
    |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors
+error: aborting due to previous error; 1 warning emitted
 
+For more information about this error, try `rustc --explain E0507`.
 Future incompatibility report: Future breakage diagnostic:
-error: `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-  --> $DIR/deriving-with-repr-packed.rs:11:16
-   |
-LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                ^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-note: the lint level is defined here
-  --> $DIR/deriving-with-repr-packed.rs:1:9
-   |
-LL | #![deny(unaligned_references)]
-   |         ^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-Future breakage diagnostic:
-error: `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-  --> $DIR/deriving-with-repr-packed.rs:11:32
-   |
-LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                                ^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-note: the lint level is defined here
-  --> $DIR/deriving-with-repr-packed.rs:1:9
-   |
-LL | #![deny(unaligned_references)]
-   |         ^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-Future breakage diagnostic:
-error: `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-  --> $DIR/deriving-with-repr-packed.rs:19:19
-   |
-LL | #[derive(Default, Hash)]
-   |                   ^^^^
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-with-repr-packed.rs:33:5
    |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-note: the lint level is defined here
-  --> $DIR/deriving-with-repr-packed.rs:1:9
-   |
-LL | #![deny(unaligned_references)]
-   |         ^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-Future breakage diagnostic:
-error: `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-  --> $DIR/deriving-with-repr-packed.rs:39:10
-   |
-LL | #[derive(Debug, Default)]
-   |          ^^^^^
+LL | #[derive(Debug)]
+   |          ----- in this derive macro expansion
+...
+LL |     data: [u8],
+   |     ^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-note: the lint level is defined here
-  --> $DIR/deriving-with-repr-packed.rs:1:9
-   |
-LL | #![deny(unaligned_references)]
-   |         ^^^^^^^^^^^^^^^^^^^^
-   = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/tests/ui/deriving/deriving-all-codegen.rs b/tests/ui/deriving/deriving-all-codegen.rs
index ba7809413bd..51f9708d3cd 100644
--- a/tests/ui/deriving/deriving-all-codegen.rs
+++ b/tests/ui/deriving/deriving-all-codegen.rs
@@ -21,36 +21,88 @@
 #[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 struct Empty;
 
-// A basic struct.
+// A basic struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
 #[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 struct Point {
     x: u32,
     y: u32,
 }
 
-// A large struct.
-#[derive(Clone, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+// A basic packed struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
+#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(packed)]
+struct PackedPoint {
+    x: u32,
+    y: u32,
+}
+
+// A large struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
+#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 struct Big {
     b1: u32, b2: u32, b3: u32, b4: u32, b5: u32, b6: u32, b7: u32, b8: u32,
 }
 
+// A struct that doesn't impl `Copy`, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+#[derive(Clone)]
+struct NonCopy(u32);
+
+// A packed struct that doesn't impl `Copy`, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+#[derive(Clone)]
+#[repr(packed)]
+struct PackedNonCopy(u32);
+
+// A struct that impls `Copy` manually, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+#[derive(Clone)]
+struct ManualCopy(u32);
+impl Copy for ManualCopy {}
+
+// A packed struct that impls `Copy` manually, which means it gets the
+// non-simple `clone` implemention that clones the fields individually.
+#[derive(Clone)]
+#[repr(packed)]
+struct PackedManualCopy(u32);
+impl Copy for PackedManualCopy {}
+
 // A struct with an unsized field. Some derives are not usable in this case.
 #[derive(Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
 struct Unsized([u32]);
 
-// A packed tuple struct that impls `Copy`.
-#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+// A packed struct with an unsized `[u8]` field. This is currently allowed, but
+// causes a warning and will be phased out at some point.
+#[derive(Debug, Hash)]
 #[repr(packed)]
-struct PackedCopy(u32);
+struct PackedUnsizedU8([u8]);
+//~^ WARNING byte slice in a packed struct that derives a built-in trait
+//~^^ WARNING byte slice in a packed struct that derives a built-in trait
+//~^^^ this was previously accepted
+//~^^^^ this was previously accepted
 
-// A packed tuple struct that does not impl `Copy`. Note that the alignment of
-// the field must be 1 for this code to be valid. Otherwise it triggers an
-// error "`#[derive]` can't be used on a `#[repr(packed)]` struct that does not
-// derive Copy (error E0133)" at MIR building time. This is a weird case and
-// it's possible that this struct is not supposed to work, but for now it does.
-#[derive(Clone, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+trait Trait {
+    type A;
+}
+
+// A generic struct involving an associated type.
+#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+struct Generic<T: Trait, U> {
+    t: T,
+    ta: T::A,
+    u: U,
+}
+
+// A packed, generic tuple struct involving an associated type. Because it is
+// packed, a `T: Copy` bound is added to all impls (and where clauses within
+// them) except for `Default`. This is because we must access fields using
+// copies (e.g. `&{self.0}`), instead of using direct references (e.g.
+// `&self.0`) which may be misaligned in a packed struct.
+#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 #[repr(packed)]
-struct PackedNonCopy(u8);
+struct PackedGeneric<T: Trait, U>(T, T::A, U);
 
 // An empty enum.
 #[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
@@ -97,6 +149,13 @@ enum Fielded {
     Z(Option<i32>),
 }
 
+// A generic enum. Note that `Default` cannot be derived for this enum.
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+enum EnumGeneric<T, U> {
+    One(T),
+    Two(U),
+}
+
 // A union. Most builtin traits are not derivable for unions.
 #[derive(Clone, Copy)]
 pub union Union {
diff --git a/tests/ui/deriving/deriving-all-codegen.stderr b/tests/ui/deriving/deriving-all-codegen.stderr
new file mode 100644
index 00000000000..503f0cae73b
--- /dev/null
+++ b/tests/ui/deriving/deriving-all-codegen.stderr
@@ -0,0 +1,63 @@
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-all-codegen.rs:80:24
+   |
+LL | #[derive(Debug, Hash)]
+   |          ----- in this derive macro expansion
+LL | #[repr(packed)]
+LL | struct PackedUnsizedU8([u8]);
+   |                        ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-all-codegen.rs:80:24
+   |
+LL | #[derive(Debug, Hash)]
+   |                 ---- in this derive macro expansion
+LL | #[repr(packed)]
+LL | struct PackedUnsizedU8([u8]);
+   |                        ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: this warning originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: 2 warnings emitted
+
+Future incompatibility report: Future breakage diagnostic:
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-all-codegen.rs:80:24
+   |
+LL | #[derive(Debug, Hash)]
+   |          ----- in this derive macro expansion
+LL | #[repr(packed)]
+LL | struct PackedUnsizedU8([u8]);
+   |                        ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+Future breakage diagnostic:
+warning: byte slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-all-codegen.rs:80:24
+   |
+LL | #[derive(Debug, Hash)]
+   |                 ---- in this derive macro expansion
+LL | #[repr(packed)]
+LL | struct PackedUnsizedU8([u8]);
+   |                        ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
+
diff --git a/tests/ui/deriving/deriving-all-codegen.stdout b/tests/ui/deriving/deriving-all-codegen.stdout
index e6ee11a783b..b4874cef134 100644
--- a/tests/ui/deriving/deriving-all-codegen.stdout
+++ b/tests/ui/deriving/deriving-all-codegen.stdout
@@ -78,7 +78,8 @@ impl ::core::cmp::Ord for Empty {
     }
 }
 
-// A basic struct.
+// A basic struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
 struct Point {
     x: u32,
     y: u32,
@@ -161,7 +162,95 @@ impl ::core::cmp::Ord for Point {
     }
 }
 
-// A large struct.
+// A basic packed struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
+#[repr(packed)]
+struct PackedPoint {
+    x: u32,
+    y: u32,
+}
+#[automatically_derived]
+impl ::core::clone::Clone for PackedPoint {
+    #[inline]
+    fn clone(&self) -> PackedPoint {
+        let _: ::core::clone::AssertParamIsClone<u32>;
+        *self
+    }
+}
+#[automatically_derived]
+impl ::core::marker::Copy for PackedPoint { }
+#[automatically_derived]
+impl ::core::fmt::Debug for PackedPoint {
+    fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+        ::core::fmt::Formatter::debug_struct_field2_finish(f, "PackedPoint",
+            "x", &&{ self.x }, "y", &&{ self.y })
+    }
+}
+#[automatically_derived]
+impl ::core::default::Default for PackedPoint {
+    #[inline]
+    fn default() -> PackedPoint {
+        PackedPoint {
+            x: ::core::default::Default::default(),
+            y: ::core::default::Default::default(),
+        }
+    }
+}
+#[automatically_derived]
+impl ::core::hash::Hash for PackedPoint {
+    fn hash<__H: ::core::hash::Hasher>(&self, state: &mut __H) -> () {
+        ::core::hash::Hash::hash(&{ self.x }, state);
+        ::core::hash::Hash::hash(&{ self.y }, state)
+    }
+}
+#[automatically_derived]
+impl ::core::marker::StructuralPartialEq for PackedPoint { }
+#[automatically_derived]
+impl ::core::cmp::PartialEq for PackedPoint {
+    #[inline]
+    fn eq(&self, other: &PackedPoint) -> bool {
+        { self.x } == { other.x } && { self.y } == { other.y }
+    }
+}
+#[automatically_derived]
+impl ::core::marker::StructuralEq for PackedPoint { }
+#[automatically_derived]
+impl ::core::cmp::Eq for PackedPoint {
+    #[inline]
+    #[doc(hidden)]
+    #[no_coverage]
+    fn assert_receiver_is_total_eq(&self) -> () {
+        let _: ::core::cmp::AssertParamIsEq<u32>;
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for PackedPoint {
+    #[inline]
+    fn partial_cmp(&self, other: &PackedPoint)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        match ::core::cmp::PartialOrd::partial_cmp(&{ self.x }, &{ other.x })
+            {
+            ::core::option::Option::Some(::core::cmp::Ordering::Equal) =>
+                ::core::cmp::PartialOrd::partial_cmp(&{ self.y },
+                    &{ other.y }),
+            cmp => cmp,
+        }
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::Ord for PackedPoint {
+    #[inline]
+    fn cmp(&self, other: &PackedPoint) -> ::core::cmp::Ordering {
+        match ::core::cmp::Ord::cmp(&{ self.x }, &{ other.x }) {
+            ::core::cmp::Ordering::Equal =>
+                ::core::cmp::Ord::cmp(&{ self.y }, &{ other.y }),
+            cmp => cmp,
+        }
+    }
+}
+
+// A large struct. Note: because this derives `Copy`, it gets the simple
+// `clone` implemention that just does `*self`.
 struct Big {
     b1: u32,
     b2: u32,
@@ -176,19 +265,13 @@ struct Big {
 impl ::core::clone::Clone for Big {
     #[inline]
     fn clone(&self) -> Big {
-        Big {
-            b1: ::core::clone::Clone::clone(&self.b1),
-            b2: ::core::clone::Clone::clone(&self.b2),
-            b3: ::core::clone::Clone::clone(&self.b3),
-            b4: ::core::clone::Clone::clone(&self.b4),
-            b5: ::core::clone::Clone::clone(&self.b5),
-            b6: ::core::clone::Clone::clone(&self.b6),
-            b7: ::core::clone::Clone::clone(&self.b7),
-            b8: ::core::clone::Clone::clone(&self.b8),
-        }
+        let _: ::core::clone::AssertParamIsClone<u32>;
+        *self
     }
 }
 #[automatically_derived]
+impl ::core::marker::Copy for Big { }
+#[automatically_derived]
 impl ::core::fmt::Debug for Big {
     fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
         let names: &'static _ =
@@ -336,6 +419,54 @@ impl ::core::cmp::Ord for Big {
     }
 }
 
+// A struct that doesn't impl `Copy`, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+struct NonCopy(u32);
+#[automatically_derived]
+impl ::core::clone::Clone for NonCopy {
+    #[inline]
+    fn clone(&self) -> NonCopy {
+        NonCopy(::core::clone::Clone::clone(&self.0))
+    }
+}
+
+// A packed struct that doesn't impl `Copy`, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+#[repr(packed)]
+struct PackedNonCopy(u32);
+#[automatically_derived]
+impl ::core::clone::Clone for PackedNonCopy {
+    #[inline]
+    fn clone(&self) -> PackedNonCopy {
+        PackedNonCopy(::core::clone::Clone::clone(&{ self.0 }))
+    }
+}
+
+// A struct that impls `Copy` manually, which means it gets the non-simple
+// `clone` implemention that clones the fields individually.
+struct ManualCopy(u32);
+#[automatically_derived]
+impl ::core::clone::Clone for ManualCopy {
+    #[inline]
+    fn clone(&self) -> ManualCopy {
+        ManualCopy(::core::clone::Clone::clone(&self.0))
+    }
+}
+impl Copy for ManualCopy {}
+
+// A packed struct that impls `Copy` manually, which means it gets the
+// non-simple `clone` implemention that clones the fields individually.
+#[repr(packed)]
+struct PackedManualCopy(u32);
+#[automatically_derived]
+impl ::core::clone::Clone for PackedManualCopy {
+    #[inline]
+    fn clone(&self) -> PackedManualCopy {
+        PackedManualCopy(::core::clone::Clone::clone(&{ self.0 }))
+    }
+}
+impl Copy for PackedManualCopy {}
+
 // A struct with an unsized field. Some derives are not usable in this case.
 struct Unsized([u32]);
 #[automatically_derived]
@@ -385,138 +516,265 @@ impl ::core::cmp::Ord for Unsized {
     }
 }
 
-// A packed tuple struct that impls `Copy`.
+// A packed struct with an unsized `[u8]` field. This is currently allowed, but
+// causes a warning and will be phased out at some point.
 #[repr(packed)]
-struct PackedCopy(u32);
+struct PackedUnsizedU8([u8]);
 #[automatically_derived]
-impl ::core::clone::Clone for PackedCopy {
+impl ::core::fmt::Debug for PackedUnsizedU8 {
+    fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+        ::core::fmt::Formatter::debug_tuple_field1_finish(f,
+            "PackedUnsizedU8", &&self.0)
+    }
+}
+#[automatically_derived]
+impl ::core::hash::Hash for PackedUnsizedU8 {
+    fn hash<__H: ::core::hash::Hasher>(&self, state: &mut __H) -> () {
+        ::core::hash::Hash::hash(&self.0, state)
+    }
+}
+
+trait Trait {
+    type A;
+}
+
+// A generic struct involving an associated type.
+struct Generic<T: Trait, U> {
+    t: T,
+    ta: T::A,
+    u: U,
+}
+#[automatically_derived]
+impl<T: ::core::clone::Clone + Trait, U: ::core::clone::Clone>
+    ::core::clone::Clone for Generic<T, U> where T::A: ::core::clone::Clone {
     #[inline]
-    fn clone(&self) -> PackedCopy {
-        let _: ::core::clone::AssertParamIsClone<u32>;
-        *self
+    fn clone(&self) -> Generic<T, U> {
+        Generic {
+            t: ::core::clone::Clone::clone(&self.t),
+            ta: ::core::clone::Clone::clone(&self.ta),
+            u: ::core::clone::Clone::clone(&self.u),
+        }
     }
 }
 #[automatically_derived]
-impl ::core::marker::Copy for PackedCopy { }
+impl<T: ::core::marker::Copy + Trait, U: ::core::marker::Copy>
+    ::core::marker::Copy for Generic<T, U> where T::A: ::core::marker::Copy {
+}
 #[automatically_derived]
-impl ::core::fmt::Debug for PackedCopy {
+impl<T: ::core::fmt::Debug + Trait, U: ::core::fmt::Debug> ::core::fmt::Debug
+    for Generic<T, U> where T::A: ::core::fmt::Debug {
     fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
-        ::core::fmt::Formatter::debug_tuple_field1_finish(f, "PackedCopy",
-            &&{ self.0 })
+        ::core::fmt::Formatter::debug_struct_field3_finish(f, "Generic", "t",
+            &&self.t, "ta", &&self.ta, "u", &&self.u)
     }
 }
 #[automatically_derived]
-impl ::core::default::Default for PackedCopy {
+impl<T: ::core::default::Default + Trait, U: ::core::default::Default>
+    ::core::default::Default for Generic<T, U> where
+    T::A: ::core::default::Default {
     #[inline]
-    fn default() -> PackedCopy {
-        PackedCopy(::core::default::Default::default())
+    fn default() -> Generic<T, U> {
+        Generic {
+            t: ::core::default::Default::default(),
+            ta: ::core::default::Default::default(),
+            u: ::core::default::Default::default(),
+        }
     }
 }
 #[automatically_derived]
-impl ::core::hash::Hash for PackedCopy {
+impl<T: ::core::hash::Hash + Trait, U: ::core::hash::Hash> ::core::hash::Hash
+    for Generic<T, U> where T::A: ::core::hash::Hash {
     fn hash<__H: ::core::hash::Hasher>(&self, state: &mut __H) -> () {
-        ::core::hash::Hash::hash(&{ self.0 }, state)
+        ::core::hash::Hash::hash(&self.t, state);
+        ::core::hash::Hash::hash(&self.ta, state);
+        ::core::hash::Hash::hash(&self.u, state)
     }
 }
 #[automatically_derived]
-impl ::core::marker::StructuralPartialEq for PackedCopy { }
+impl<T: Trait, U> ::core::marker::StructuralPartialEq for Generic<T, U> { }
 #[automatically_derived]
-impl ::core::cmp::PartialEq for PackedCopy {
+impl<T: ::core::cmp::PartialEq + Trait, U: ::core::cmp::PartialEq>
+    ::core::cmp::PartialEq for Generic<T, U> where
+    T::A: ::core::cmp::PartialEq {
     #[inline]
-    fn eq(&self, other: &PackedCopy) -> bool { { self.0 } == { other.0 } }
+    fn eq(&self, other: &Generic<T, U>) -> bool {
+        self.t == other.t && self.ta == other.ta && self.u == other.u
+    }
 }
 #[automatically_derived]
-impl ::core::marker::StructuralEq for PackedCopy { }
+impl<T: Trait, U> ::core::marker::StructuralEq for Generic<T, U> { }
 #[automatically_derived]
-impl ::core::cmp::Eq for PackedCopy {
+impl<T: ::core::cmp::Eq + Trait, U: ::core::cmp::Eq> ::core::cmp::Eq for
+    Generic<T, U> where T::A: ::core::cmp::Eq {
     #[inline]
     #[doc(hidden)]
     #[no_coverage]
     fn assert_receiver_is_total_eq(&self) -> () {
-        let _: ::core::cmp::AssertParamIsEq<u32>;
+        let _: ::core::cmp::AssertParamIsEq<T>;
+        let _: ::core::cmp::AssertParamIsEq<T::A>;
+        let _: ::core::cmp::AssertParamIsEq<U>;
     }
 }
 #[automatically_derived]
-impl ::core::cmp::PartialOrd for PackedCopy {
+impl<T: ::core::cmp::PartialOrd + Trait, U: ::core::cmp::PartialOrd>
+    ::core::cmp::PartialOrd for Generic<T, U> where
+    T::A: ::core::cmp::PartialOrd {
     #[inline]
-    fn partial_cmp(&self, other: &PackedCopy)
+    fn partial_cmp(&self, other: &Generic<T, U>)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::cmp::PartialOrd::partial_cmp(&{ self.0 }, &{ other.0 })
+        match ::core::cmp::PartialOrd::partial_cmp(&self.t, &other.t) {
+            ::core::option::Option::Some(::core::cmp::Ordering::Equal) =>
+                match ::core::cmp::PartialOrd::partial_cmp(&self.ta,
+                        &other.ta) {
+                    ::core::option::Option::Some(::core::cmp::Ordering::Equal)
+                        => ::core::cmp::PartialOrd::partial_cmp(&self.u, &other.u),
+                    cmp => cmp,
+                },
+            cmp => cmp,
+        }
     }
 }
 #[automatically_derived]
-impl ::core::cmp::Ord for PackedCopy {
+impl<T: ::core::cmp::Ord + Trait, U: ::core::cmp::Ord> ::core::cmp::Ord for
+    Generic<T, U> where T::A: ::core::cmp::Ord {
     #[inline]
-    fn cmp(&self, other: &PackedCopy) -> ::core::cmp::Ordering {
-        ::core::cmp::Ord::cmp(&{ self.0 }, &{ other.0 })
+    fn cmp(&self, other: &Generic<T, U>) -> ::core::cmp::Ordering {
+        match ::core::cmp::Ord::cmp(&self.t, &other.t) {
+            ::core::cmp::Ordering::Equal =>
+                match ::core::cmp::Ord::cmp(&self.ta, &other.ta) {
+                    ::core::cmp::Ordering::Equal =>
+                        ::core::cmp::Ord::cmp(&self.u, &other.u),
+                    cmp => cmp,
+                },
+            cmp => cmp,
+        }
     }
 }
 
-// A packed tuple struct that does not impl `Copy`. Note that the alignment of
-// the field must be 1 for this code to be valid. Otherwise it triggers an
-// error "`#[derive]` can't be used on a `#[repr(packed)]` struct that does not
-// derive Copy (error E0133)" at MIR building time. This is a weird case and
-// it's possible that this struct is not supposed to work, but for now it does.
+// A packed, generic tuple struct involving an associated type. Because it is
+// packed, a `T: Copy` bound is added to all impls (and where clauses within
+// them) except for `Default`. This is because we must access fields using
+// copies (e.g. `&{self.0}`), instead of using direct references (e.g.
+// `&self.0`) which may be misaligned in a packed struct.
 #[repr(packed)]
-struct PackedNonCopy(u8);
+struct PackedGeneric<T: Trait, U>(T, T::A, U);
 #[automatically_derived]
-impl ::core::clone::Clone for PackedNonCopy {
+impl<T: ::core::clone::Clone + ::core::marker::Copy + Trait,
+    U: ::core::clone::Clone + ::core::marker::Copy> ::core::clone::Clone for
+    PackedGeneric<T, U> where T::A: ::core::clone::Clone +
+    ::core::marker::Copy {
     #[inline]
-    fn clone(&self) -> PackedNonCopy {
-        PackedNonCopy(::core::clone::Clone::clone(&self.0))
+    fn clone(&self) -> PackedGeneric<T, U> {
+        PackedGeneric(::core::clone::Clone::clone(&{ self.0 }),
+            ::core::clone::Clone::clone(&{ self.1 }),
+            ::core::clone::Clone::clone(&{ self.2 }))
     }
 }
 #[automatically_derived]
-impl ::core::fmt::Debug for PackedNonCopy {
+impl<T: ::core::marker::Copy + Trait, U: ::core::marker::Copy>
+    ::core::marker::Copy for PackedGeneric<T, U> where
+    T::A: ::core::marker::Copy {
+}
+#[automatically_derived]
+impl<T: ::core::fmt::Debug + ::core::marker::Copy + Trait,
+    U: ::core::fmt::Debug + ::core::marker::Copy> ::core::fmt::Debug for
+    PackedGeneric<T, U> where T::A: ::core::fmt::Debug + ::core::marker::Copy
+    {
     fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
-        ::core::fmt::Formatter::debug_tuple_field1_finish(f, "PackedNonCopy",
-            &&self.0)
+        ::core::fmt::Formatter::debug_tuple_field3_finish(f, "PackedGeneric",
+            &&{ self.0 }, &&{ self.1 }, &&{ self.2 })
     }
 }
 #[automatically_derived]
-impl ::core::default::Default for PackedNonCopy {
+impl<T: ::core::default::Default + Trait, U: ::core::default::Default>
+    ::core::default::Default for PackedGeneric<T, U> where
+    T::A: ::core::default::Default {
     #[inline]
-    fn default() -> PackedNonCopy {
-        PackedNonCopy(::core::default::Default::default())
+    fn default() -> PackedGeneric<T, U> {
+        PackedGeneric(::core::default::Default::default(),
+            ::core::default::Default::default(),
+            ::core::default::Default::default())
     }
 }
 #[automatically_derived]
-impl ::core::hash::Hash for PackedNonCopy {
+impl<T: ::core::hash::Hash + ::core::marker::Copy + Trait,
+    U: ::core::hash::Hash + ::core::marker::Copy> ::core::hash::Hash for
+    PackedGeneric<T, U> where T::A: ::core::hash::Hash + ::core::marker::Copy
+    {
     fn hash<__H: ::core::hash::Hasher>(&self, state: &mut __H) -> () {
-        ::core::hash::Hash::hash(&self.0, state)
+        ::core::hash::Hash::hash(&{ self.0 }, state);
+        ::core::hash::Hash::hash(&{ self.1 }, state);
+        ::core::hash::Hash::hash(&{ self.2 }, state)
     }
 }
 #[automatically_derived]
-impl ::core::marker::StructuralPartialEq for PackedNonCopy { }
+impl<T: Trait, U> ::core::marker::StructuralPartialEq for PackedGeneric<T, U>
+    {
+}
 #[automatically_derived]
-impl ::core::cmp::PartialEq for PackedNonCopy {
+impl<T: ::core::cmp::PartialEq + ::core::marker::Copy + Trait,
+    U: ::core::cmp::PartialEq + ::core::marker::Copy> ::core::cmp::PartialEq
+    for PackedGeneric<T, U> where T::A: ::core::cmp::PartialEq +
+    ::core::marker::Copy {
     #[inline]
-    fn eq(&self, other: &PackedNonCopy) -> bool { self.0 == other.0 }
+    fn eq(&self, other: &PackedGeneric<T, U>) -> bool {
+        { self.0 } == { other.0 } && { self.1 } == { other.1 } &&
+            { self.2 } == { other.2 }
+    }
 }
 #[automatically_derived]
-impl ::core::marker::StructuralEq for PackedNonCopy { }
+impl<T: Trait, U> ::core::marker::StructuralEq for PackedGeneric<T, U> { }
 #[automatically_derived]
-impl ::core::cmp::Eq for PackedNonCopy {
+impl<T: ::core::cmp::Eq + ::core::marker::Copy + Trait, U: ::core::cmp::Eq +
+    ::core::marker::Copy> ::core::cmp::Eq for PackedGeneric<T, U> where
+    T::A: ::core::cmp::Eq + ::core::marker::Copy {
     #[inline]
     #[doc(hidden)]
     #[no_coverage]
     fn assert_receiver_is_total_eq(&self) -> () {
-        let _: ::core::cmp::AssertParamIsEq<u8>;
+        let _: ::core::cmp::AssertParamIsEq<T>;
+        let _: ::core::cmp::AssertParamIsEq<T::A>;
+        let _: ::core::cmp::AssertParamIsEq<U>;
     }
 }
 #[automatically_derived]
-impl ::core::cmp::PartialOrd for PackedNonCopy {
+impl<T: ::core::cmp::PartialOrd + ::core::marker::Copy + Trait,
+    U: ::core::cmp::PartialOrd + ::core::marker::Copy> ::core::cmp::PartialOrd
+    for PackedGeneric<T, U> where T::A: ::core::cmp::PartialOrd +
+    ::core::marker::Copy {
     #[inline]
-    fn partial_cmp(&self, other: &PackedNonCopy)
+    fn partial_cmp(&self, other: &PackedGeneric<T, U>)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::cmp::PartialOrd::partial_cmp(&self.0, &other.0)
+        match ::core::cmp::PartialOrd::partial_cmp(&{ self.0 }, &{ other.0 })
+            {
+            ::core::option::Option::Some(::core::cmp::Ordering::Equal) =>
+                match ::core::cmp::PartialOrd::partial_cmp(&{ self.1 },
+                        &{ other.1 }) {
+                    ::core::option::Option::Some(::core::cmp::Ordering::Equal)
+                        =>
+                        ::core::cmp::PartialOrd::partial_cmp(&{ self.2 },
+                            &{ other.2 }),
+                    cmp => cmp,
+                },
+            cmp => cmp,
+        }
     }
 }
 #[automatically_derived]
-impl ::core::cmp::Ord for PackedNonCopy {
+impl<T: ::core::cmp::Ord + ::core::marker::Copy + Trait, U: ::core::cmp::Ord +
+    ::core::marker::Copy> ::core::cmp::Ord for PackedGeneric<T, U> where
+    T::A: ::core::cmp::Ord + ::core::marker::Copy {
     #[inline]
-    fn cmp(&self, other: &PackedNonCopy) -> ::core::cmp::Ordering {
-        ::core::cmp::Ord::cmp(&self.0, &other.0)
+    fn cmp(&self, other: &PackedGeneric<T, U>) -> ::core::cmp::Ordering {
+        match ::core::cmp::Ord::cmp(&{ self.0 }, &{ other.0 }) {
+            ::core::cmp::Ordering::Equal =>
+                match ::core::cmp::Ord::cmp(&{ self.1 }, &{ other.1 }) {
+                    ::core::cmp::Ordering::Equal =>
+                        ::core::cmp::Ord::cmp(&{ self.2 }, &{ other.2 }),
+                    cmp => cmp,
+                },
+            cmp => cmp,
+        }
     }
 }
 
@@ -889,23 +1147,20 @@ impl ::core::cmp::PartialOrd for Mixed {
         -> ::core::option::Option<::core::cmp::Ordering> {
         let __self_tag = ::core::intrinsics::discriminant_value(self);
         let __arg1_tag = ::core::intrinsics::discriminant_value(other);
-        match ::core::cmp::PartialOrd::partial_cmp(&__self_tag, &__arg1_tag) {
-            ::core::option::Option::Some(::core::cmp::Ordering::Equal) =>
-                match (self, other) {
-                    (Mixed::R(__self_0), Mixed::R(__arg1_0)) =>
-                        ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
-                    (Mixed::S { d1: __self_0, d2: __self_1 }, Mixed::S {
-                        d1: __arg1_0, d2: __arg1_1 }) =>
-                        match ::core::cmp::PartialOrd::partial_cmp(__self_0,
-                                __arg1_0) {
-                            ::core::option::Option::Some(::core::cmp::Ordering::Equal)
-                                => ::core::cmp::PartialOrd::partial_cmp(__self_1, __arg1_1),
-                            cmp => cmp,
-                        },
-                    _ =>
-                        ::core::option::Option::Some(::core::cmp::Ordering::Equal),
+        match (self, other) {
+            (Mixed::R(__self_0), Mixed::R(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            (Mixed::S { d1: __self_0, d2: __self_1 }, Mixed::S {
+                d1: __arg1_0, d2: __arg1_1 }) =>
+                match ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0)
+                    {
+                    ::core::option::Option::Some(::core::cmp::Ordering::Equal)
+                        => ::core::cmp::PartialOrd::partial_cmp(__self_1, __arg1_1),
+                    cmp => cmp,
                 },
-            cmp => cmp,
+            _ =>
+                ::core::cmp::PartialOrd::partial_cmp(&__self_tag,
+                    &__arg1_tag),
         }
     }
 }
@@ -1019,35 +1274,152 @@ impl ::core::cmp::PartialOrd for Fielded {
         -> ::core::option::Option<::core::cmp::Ordering> {
         let __self_tag = ::core::intrinsics::discriminant_value(self);
         let __arg1_tag = ::core::intrinsics::discriminant_value(other);
-        match ::core::cmp::PartialOrd::partial_cmp(&__self_tag, &__arg1_tag) {
-            ::core::option::Option::Some(::core::cmp::Ordering::Equal) =>
+        match (self, other) {
+            (Fielded::X(__self_0), Fielded::X(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            (Fielded::Y(__self_0), Fielded::Y(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            (Fielded::Z(__self_0), Fielded::Z(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            _ =>
+                ::core::cmp::PartialOrd::partial_cmp(&__self_tag,
+                    &__arg1_tag),
+        }
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::Ord for Fielded {
+    #[inline]
+    fn cmp(&self, other: &Fielded) -> ::core::cmp::Ordering {
+        let __self_tag = ::core::intrinsics::discriminant_value(self);
+        let __arg1_tag = ::core::intrinsics::discriminant_value(other);
+        match ::core::cmp::Ord::cmp(&__self_tag, &__arg1_tag) {
+            ::core::cmp::Ordering::Equal =>
                 match (self, other) {
                     (Fielded::X(__self_0), Fielded::X(__arg1_0)) =>
-                        ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+                        ::core::cmp::Ord::cmp(__self_0, __arg1_0),
                     (Fielded::Y(__self_0), Fielded::Y(__arg1_0)) =>
-                        ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+                        ::core::cmp::Ord::cmp(__self_0, __arg1_0),
                     (Fielded::Z(__self_0), Fielded::Z(__arg1_0)) =>
-                        ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+                        ::core::cmp::Ord::cmp(__self_0, __arg1_0),
                     _ => unsafe { ::core::intrinsics::unreachable() }
                 },
             cmp => cmp,
         }
     }
 }
+
+// A generic enum. Note that `Default` cannot be derived for this enum.
+enum EnumGeneric<T, U> { One(T), Two(U), }
 #[automatically_derived]
-impl ::core::cmp::Ord for Fielded {
+impl<T: ::core::clone::Clone, U: ::core::clone::Clone> ::core::clone::Clone
+    for EnumGeneric<T, U> {
     #[inline]
-    fn cmp(&self, other: &Fielded) -> ::core::cmp::Ordering {
+    fn clone(&self) -> EnumGeneric<T, U> {
+        match self {
+            EnumGeneric::One(__self_0) =>
+                EnumGeneric::One(::core::clone::Clone::clone(__self_0)),
+            EnumGeneric::Two(__self_0) =>
+                EnumGeneric::Two(::core::clone::Clone::clone(__self_0)),
+        }
+    }
+}
+#[automatically_derived]
+impl<T: ::core::marker::Copy, U: ::core::marker::Copy> ::core::marker::Copy
+    for EnumGeneric<T, U> {
+}
+#[automatically_derived]
+impl<T: ::core::fmt::Debug, U: ::core::fmt::Debug> ::core::fmt::Debug for
+    EnumGeneric<T, U> {
+    fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+        match self {
+            EnumGeneric::One(__self_0) =>
+                ::core::fmt::Formatter::debug_tuple_field1_finish(f, "One",
+                    &__self_0),
+            EnumGeneric::Two(__self_0) =>
+                ::core::fmt::Formatter::debug_tuple_field1_finish(f, "Two",
+                    &__self_0),
+        }
+    }
+}
+#[automatically_derived]
+impl<T: ::core::hash::Hash, U: ::core::hash::Hash> ::core::hash::Hash for
+    EnumGeneric<T, U> {
+    fn hash<__H: ::core::hash::Hasher>(&self, state: &mut __H) -> () {
+        let __self_tag = ::core::intrinsics::discriminant_value(self);
+        ::core::hash::Hash::hash(&__self_tag, state);
+        match self {
+            EnumGeneric::One(__self_0) =>
+                ::core::hash::Hash::hash(__self_0, state),
+            EnumGeneric::Two(__self_0) =>
+                ::core::hash::Hash::hash(__self_0, state),
+        }
+    }
+}
+#[automatically_derived]
+impl<T, U> ::core::marker::StructuralPartialEq for EnumGeneric<T, U> { }
+#[automatically_derived]
+impl<T: ::core::cmp::PartialEq, U: ::core::cmp::PartialEq>
+    ::core::cmp::PartialEq for EnumGeneric<T, U> {
+    #[inline]
+    fn eq(&self, other: &EnumGeneric<T, U>) -> bool {
+        let __self_tag = ::core::intrinsics::discriminant_value(self);
+        let __arg1_tag = ::core::intrinsics::discriminant_value(other);
+        __self_tag == __arg1_tag &&
+            match (self, other) {
+                (EnumGeneric::One(__self_0), EnumGeneric::One(__arg1_0)) =>
+                    *__self_0 == *__arg1_0,
+                (EnumGeneric::Two(__self_0), EnumGeneric::Two(__arg1_0)) =>
+                    *__self_0 == *__arg1_0,
+                _ => unsafe { ::core::intrinsics::unreachable() }
+            }
+    }
+}
+#[automatically_derived]
+impl<T, U> ::core::marker::StructuralEq for EnumGeneric<T, U> { }
+#[automatically_derived]
+impl<T: ::core::cmp::Eq, U: ::core::cmp::Eq> ::core::cmp::Eq for
+    EnumGeneric<T, U> {
+    #[inline]
+    #[doc(hidden)]
+    #[no_coverage]
+    fn assert_receiver_is_total_eq(&self) -> () {
+        let _: ::core::cmp::AssertParamIsEq<T>;
+        let _: ::core::cmp::AssertParamIsEq<U>;
+    }
+}
+#[automatically_derived]
+impl<T: ::core::cmp::PartialOrd, U: ::core::cmp::PartialOrd>
+    ::core::cmp::PartialOrd for EnumGeneric<T, U> {
+    #[inline]
+    fn partial_cmp(&self, other: &EnumGeneric<T, U>)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        let __self_tag = ::core::intrinsics::discriminant_value(self);
+        let __arg1_tag = ::core::intrinsics::discriminant_value(other);
+        match (self, other) {
+            (EnumGeneric::One(__self_0), EnumGeneric::One(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            (EnumGeneric::Two(__self_0), EnumGeneric::Two(__arg1_0)) =>
+                ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0),
+            _ =>
+                ::core::cmp::PartialOrd::partial_cmp(&__self_tag,
+                    &__arg1_tag),
+        }
+    }
+}
+#[automatically_derived]
+impl<T: ::core::cmp::Ord, U: ::core::cmp::Ord> ::core::cmp::Ord for
+    EnumGeneric<T, U> {
+    #[inline]
+    fn cmp(&self, other: &EnumGeneric<T, U>) -> ::core::cmp::Ordering {
         let __self_tag = ::core::intrinsics::discriminant_value(self);
         let __arg1_tag = ::core::intrinsics::discriminant_value(other);
         match ::core::cmp::Ord::cmp(&__self_tag, &__arg1_tag) {
             ::core::cmp::Ordering::Equal =>
                 match (self, other) {
-                    (Fielded::X(__self_0), Fielded::X(__arg1_0)) =>
+                    (EnumGeneric::One(__self_0), EnumGeneric::One(__arg1_0)) =>
                         ::core::cmp::Ord::cmp(__self_0, __arg1_0),
-                    (Fielded::Y(__self_0), Fielded::Y(__arg1_0)) =>
-                        ::core::cmp::Ord::cmp(__self_0, __arg1_0),
-                    (Fielded::Z(__self_0), Fielded::Z(__arg1_0)) =>
+                    (EnumGeneric::Two(__self_0), EnumGeneric::Two(__arg1_0)) =>
                         ::core::cmp::Ord::cmp(__self_0, __arg1_0),
                     _ => unsafe { ::core::intrinsics::unreachable() }
                 },
diff --git a/tests/ui/dropck/drop-with-active-borrows-1.stderr b/tests/ui/dropck/drop-with-active-borrows-1.stderr
index 8d6a7f3721f..4585b22974c 100644
--- a/tests/ui/dropck/drop-with-active-borrows-1.stderr
+++ b/tests/ui/dropck/drop-with-active-borrows-1.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/drop-with-active-borrows-1.rs:4:10
    |
+LL |     let a = "".to_string();
+   |         - binding `a` declared here
 LL |     let b: Vec<&str> = a.lines().collect();
    |                        --------- borrow of `a` occurs here
 LL |     drop(a);
diff --git a/tests/ui/dropck/dropck-eyepatch-extern-crate.stderr b/tests/ui/dropck/dropck-eyepatch-extern-crate.stderr
index 5d53405579d..23d57634e8f 100644
--- a/tests/ui/dropck/dropck-eyepatch-extern-crate.stderr
+++ b/tests/ui/dropck/dropck-eyepatch-extern-crate.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch-extern-crate.rs:46:23
    |
+LL |         let (mut dt, mut dr, c_shortest): (Dt<_>, Dr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         dt = Dt("dt", &c_shortest);
    |                       ^^^^^^^^^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL |     }
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch-extern-crate.rs:68:32
    |
+LL |         let (mut pt, mut pr, c_shortest): (Pt<_, _>, Pr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         pt = Pt("pt", &c_long, &c_shortest);
    |                                ^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/dropck/dropck-eyepatch-reorder.stderr b/tests/ui/dropck/dropck-eyepatch-reorder.stderr
index 5055cdd8b2b..a5d5136b5c5 100644
--- a/tests/ui/dropck/dropck-eyepatch-reorder.stderr
+++ b/tests/ui/dropck/dropck-eyepatch-reorder.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch-reorder.rs:64:23
    |
+LL |         let (mut dt, mut dr, c_shortest): (Dt<_>, Dr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         dt = Dt("dt", &c_shortest);
    |                       ^^^^^^^^^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL |     }
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch-reorder.rs:86:32
    |
+LL |         let (mut pt, mut pr, c_shortest): (Pt<_, _>, Pr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         pt = Pt("pt", &c_long, &c_shortest);
    |                                ^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/dropck/dropck-eyepatch.stderr b/tests/ui/dropck/dropck-eyepatch.stderr
index 21295e6c601..dc3f8c05e73 100644
--- a/tests/ui/dropck/dropck-eyepatch.stderr
+++ b/tests/ui/dropck/dropck-eyepatch.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch.rs:88:23
    |
+LL |         let (mut dt, mut dr, c_shortest): (Dt<_>, Dr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         dt = Dt("dt", &c_shortest);
    |                       ^^^^^^^^^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL |     }
 error[E0597]: `c_shortest` does not live long enough
   --> $DIR/dropck-eyepatch.rs:110:32
    |
+LL |         let (mut pt, mut pr, c_shortest): (Pt<_, _>, Pr<_>, Cell<_>);
+   |                              ---------- binding `c_shortest` declared here
+...
 LL |         pt = Pt("pt", &c_long, &c_shortest);
    |                                ^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/dropck/dropck-union.stderr b/tests/ui/dropck/dropck-union.stderr
index 854e29385a8..7d48e9fdcee 100644
--- a/tests/ui/dropck/dropck-union.stderr
+++ b/tests/ui/dropck/dropck-union.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `v` does not live long enough
   --> $DIR/dropck-union.rs:37:18
    |
+LL |     let v : Wrap<C> = Wrap::new(C(Cell::new(None)));
+   |         - binding `v` declared here
 LL |     v.0.set(Some(&v));
    |                  ^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui/dropck/dropck_trait_cycle_checked.stderr b/tests/ui/dropck/dropck_trait_cycle_checked.stderr
index dc3fbed593b..4d4f7b9df11 100644
--- a/tests/ui/dropck/dropck_trait_cycle_checked.stderr
+++ b/tests/ui/dropck/dropck_trait_cycle_checked.stderr
@@ -2,7 +2,7 @@ error[E0597]: `o2` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:111:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                     -------- cast requires that `o2` is borrowed for `'static`
+   |              -- binding `o2` declared here                          -------- cast requires that `o2` is borrowed for `'static`
 LL |     o1.set0(&o2);
    |             ^^^ borrowed value does not live long enough
 ...
@@ -13,7 +13,7 @@ error[E0597]: `o3` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:112:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                     -------- cast requires that `o3` is borrowed for `'static`
+   |                  -- binding `o3` declared here                      -------- cast requires that `o3` is borrowed for `'static`
 LL |     o1.set0(&o2);
 LL |     o1.set1(&o3);
    |             ^^^ borrowed value does not live long enough
@@ -25,7 +25,7 @@ error[E0597]: `o2` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:113:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                               -------- cast requires that `o2` is borrowed for `'static`
+   |              -- binding `o2` declared here                                    -------- cast requires that `o2` is borrowed for `'static`
 ...
 LL |     o2.set0(&o2);
    |             ^^^ borrowed value does not live long enough
@@ -37,7 +37,7 @@ error[E0597]: `o3` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:114:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                               -------- cast requires that `o3` is borrowed for `'static`
+   |                  -- binding `o3` declared here                                -------- cast requires that `o3` is borrowed for `'static`
 ...
 LL |     o2.set1(&o3);
    |             ^^^ borrowed value does not live long enough
@@ -49,7 +49,7 @@ error[E0597]: `o1` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:115:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                                         -------- cast requires that `o1` is borrowed for `'static`
+   |          -- binding `o1` declared here                                                  -------- cast requires that `o1` is borrowed for `'static`
 ...
 LL |     o3.set0(&o1);
    |             ^^^ borrowed value does not live long enough
@@ -61,7 +61,7 @@ error[E0597]: `o2` does not live long enough
   --> $DIR/dropck_trait_cycle_checked.rs:116:13
    |
 LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
-   |                                                                                         -------- cast requires that `o2` is borrowed for `'static`
+   |              -- binding `o2` declared here                                              -------- cast requires that `o2` is borrowed for `'static`
 ...
 LL |     o3.set1(&o2);
    |             ^^^ borrowed value does not live long enough
diff --git a/tests/ui/dst/dst-bad-coerce3.stderr b/tests/ui/dst/dst-bad-coerce3.stderr
index 957e98bbeee..1254250bcbd 100644
--- a/tests/ui/dst/dst-bad-coerce3.stderr
+++ b/tests/ui/dst/dst-bad-coerce3.stderr
@@ -3,7 +3,9 @@ error[E0597]: `f1` does not live long enough
    |
 LL | fn baz<'a>() {
    |        -- lifetime `'a` defined here
-...
+LL |     // With a vec of ints.
+LL |     let f1 = Fat { ptr: [1, 2, 3] };
+   |         -- binding `f1` declared here
 LL |     let f2: &Fat<[isize; 3]> = &f1;
    |                                ^^^ borrowed value does not live long enough
 LL |     let f3: &'a Fat<[isize]> = f2;
@@ -18,6 +20,8 @@ error[E0597]: `f1` does not live long enough
 LL | fn baz<'a>() {
    |        -- lifetime `'a` defined here
 ...
+LL |     let f1 = Fat { ptr: Foo };
+   |         -- binding `f1` declared here
 LL |     let f2: &Fat<Foo> = &f1;
    |                         ^^^ borrowed value does not live long enough
 LL |     let f3: &'a Fat<dyn Bar> = f2;
@@ -32,6 +36,8 @@ error[E0597]: `f1` does not live long enough
 LL | fn baz<'a>() {
    |        -- lifetime `'a` defined here
 ...
+LL |     let f1 = ([1, 2, 3],);
+   |         -- binding `f1` declared here
 LL |     let f2: &([isize; 3],) = &f1;
    |                              ^^^ borrowed value does not live long enough
 LL |     let f3: &'a ([isize],) = f2;
@@ -46,6 +52,8 @@ error[E0597]: `f1` does not live long enough
 LL | fn baz<'a>() {
    |        -- lifetime `'a` defined here
 ...
+LL |     let f1 = (Foo,);
+   |         -- binding `f1` declared here
 LL |     let f2: &(Foo,) = &f1;
    |                       ^^^ borrowed value does not live long enough
 LL |     let f3: &'a (dyn Bar,) = f2;
diff --git a/tests/ui/error-codes/E0208.rs b/tests/ui/error-codes/E0208.rs
index c67d42889d6..74c138af483 100644
--- a/tests/ui/error-codes/E0208.rs
+++ b/tests/ui/error-codes/E0208.rs
@@ -1,7 +1,7 @@
 #![feature(rustc_attrs)]
 
 #[rustc_variance]
-struct Foo<'a, T> { //~ ERROR [-, o]
+struct Foo<'a, T> { //~ ERROR [+, o]
     t: &'a mut T,
 }
 
diff --git a/tests/ui/error-codes/E0208.stderr b/tests/ui/error-codes/E0208.stderr
index dbbb41e7950..2c7072a7e76 100644
--- a/tests/ui/error-codes/E0208.stderr
+++ b/tests/ui/error-codes/E0208.stderr
@@ -1,4 +1,4 @@
-error: [-, o]
+error: [+, o]
   --> $DIR/E0208.rs:4:1
    |
 LL | struct Foo<'a, T> {
diff --git a/tests/ui/error-codes/E0503.stderr b/tests/ui/error-codes/E0503.stderr
index fafe363eb47..2f02e3b1a61 100644
--- a/tests/ui/error-codes/E0503.stderr
+++ b/tests/ui/error-codes/E0503.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `value` because it was mutably borrowed
   --> $DIR/E0503.rs:4:16
    |
 LL |     let _borrow = &mut value;
-   |                   ---------- borrow of `value` occurs here
+   |                   ---------- `value` is borrowed here
 LL |     let _sum = value + 1;
    |                ^^^^^ use of borrowed `value`
 LL |     _borrow.use_mut();
diff --git a/tests/ui/error-codes/E0504.stderr b/tests/ui/error-codes/E0504.stderr
index e677e891615..20e16a53810 100644
--- a/tests/ui/error-codes/E0504.stderr
+++ b/tests/ui/error-codes/E0504.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `fancy_num` because it is borrowed
   --> $DIR/E0504.rs:9:13
    |
+LL |     let fancy_num = FancyNum { num: 5 };
+   |         --------- binding `fancy_num` declared here
 LL |     let fancy_ref = &fancy_num;
    |                     ---------- borrow of `fancy_num` occurs here
 LL |
diff --git a/tests/ui/error-codes/E0505.stderr b/tests/ui/error-codes/E0505.stderr
index bd3f37f54e0..2ecb4a75c43 100644
--- a/tests/ui/error-codes/E0505.stderr
+++ b/tests/ui/error-codes/E0505.stderr
@@ -1,6 +1,9 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/E0505.rs:9:13
    |
+LL |     let x = Value{};
+   |         - binding `x` declared here
+LL |     {
 LL |         let _ref_to_val: &Value = &x;
    |                                   -- borrow of `x` occurs here
 LL |         eat(x);
diff --git a/tests/ui/error-codes/E0506.stderr b/tests/ui/error-codes/E0506.stderr
index d70406b750a..17ad7c611f8 100644
--- a/tests/ui/error-codes/E0506.stderr
+++ b/tests/ui/error-codes/E0506.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `fancy_num` because it is borrowed
   --> $DIR/E0506.rs:8:5
    |
 LL |     let fancy_ref = &fancy_num;
-   |                     ---------- borrow of `fancy_num` occurs here
+   |                     ---------- `fancy_num` is borrowed here
 LL |     fancy_num = FancyNum { num: 6 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ assignment to borrowed `fancy_num` occurs here
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `fancy_num` is assigned to here but it was already borrowed
 LL |
 LL |     println!("Num: {}, Ref: {}", fancy_num.num, fancy_ref.num);
    |                                                 ------------- borrow later used here
diff --git a/tests/ui/error-codes/E0597.stderr b/tests/ui/error-codes/E0597.stderr
index b4a1180ad54..82e3481b65a 100644
--- a/tests/ui/error-codes/E0597.stderr
+++ b/tests/ui/error-codes/E0597.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/E0597.rs:8:16
    |
+LL |     let y = 0;
+   |         - binding `y` declared here
 LL |     x.x = Some(&y);
    |                ^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/error-codes/E0789.rs b/tests/ui/error-codes/E0789.rs
new file mode 100644
index 00000000000..c0cbbcc9d2d
--- /dev/null
+++ b/tests/ui/error-codes/E0789.rs
@@ -0,0 +1,12 @@
+// compile-flags: --crate-type lib
+
+#![feature(rustc_attrs)]
+#![feature(staged_api)]
+#![unstable(feature = "foo_module", reason = "...", issue = "123")]
+
+#[rustc_allowed_through_unstable_modules]
+// #[stable(feature = "foo", since = "1.0")]
+struct Foo;
+//~^ ERROR `rustc_allowed_through_unstable_modules` attribute must be paired with a `stable` attribute
+//~^^ ERROR `rustc_allowed_through_unstable_modules` attribute must be paired with a `stable` attribute
+// FIXME: we shouldn't have two errors here, only occurs when using `-Zdeduplicate-diagnostics=no`
diff --git a/tests/ui/error-codes/E0789.stderr b/tests/ui/error-codes/E0789.stderr
new file mode 100644
index 00000000000..faab92bae03
--- /dev/null
+++ b/tests/ui/error-codes/E0789.stderr
@@ -0,0 +1,15 @@
+error[E0789]: `rustc_allowed_through_unstable_modules` attribute must be paired with a `stable` attribute
+  --> $DIR/E0789.rs:9:1
+   |
+LL | struct Foo;
+   | ^^^^^^^^^^^
+
+error[E0789]: `rustc_allowed_through_unstable_modules` attribute must be paired with a `stable` attribute
+  --> $DIR/E0789.rs:9:1
+   |
+LL | struct Foo;
+   | ^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0789`.
diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs
new file mode 100644
index 00000000000..83366ea02b0
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs
@@ -0,0 +1,9 @@
+// Check that even though Cell: DispatchFromDyn it remains an invalid self parameter type
+
+use std::cell::Cell;
+
+trait Trait{
+    fn cell(self: Cell<&Self>); //~ ERROR invalid `self` parameter type: Cell<&Self>
+}
+
+fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr
new file mode 100644
index 00000000000..ce06ce916a7
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr
@@ -0,0 +1,12 @@
+error[E0307]: invalid `self` parameter type: Cell<&Self>
+  --> $DIR/feature-gate-dispatch-from-dyn-cell.rs:6:19
+   |
+LL |     fn cell(self: Cell<&Self>);
+   |                   ^^^^^^^^^^^
+   |
+   = note: type of `self` must be `Self` or a type that dereferences to it
+   = help: consider changing to `self`, `&self`, `&mut self`, `self: Box<Self>`, `self: Rc<Self>`, `self: Arc<Self>`, or `self: Pin<P>` (where P is one of the previous types except `Self`)
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0307`.
diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs
new file mode 100644
index 00000000000..23857cbaca8
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs
@@ -0,0 +1,35 @@
+// Check that a self parameter type requires a DispatchFromDyn impl to be object safe
+
+#![feature(arbitrary_self_types, unsize, coerce_unsized)]
+
+use std::{
+    marker::Unsize,
+    ops::{CoerceUnsized, Deref},
+};
+
+struct Ptr<T: ?Sized>(Box<T>);
+
+impl<T: ?Sized> Deref for Ptr<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        &*self.0
+    }
+}
+
+impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {}
+// Because this impl is missing the coercion below fails.
+// impl<T: Unsize<U> + ?Sized, U: ?Sized> DispatchFromDyn<Ptr<U>> for Ptr<T> {}
+
+trait Trait {
+    fn ptr(self: Ptr<Self>);
+}
+impl Trait for i32 {
+    fn ptr(self: Ptr<Self>) {}
+}
+
+fn main() {
+    Ptr(Box::new(4)) as Ptr<dyn Trait>;
+    //~^ ERROR the trait `Trait` cannot be made into an object
+    //~^^ ERROR the trait `Trait` cannot be made into an object
+}
diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr
new file mode 100644
index 00000000000..d81eade8e9b
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr
@@ -0,0 +1,45 @@
+error[E0038]: the trait `Trait` cannot be made into an object
+  --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:32:25
+   |
+LL |     fn ptr(self: Ptr<Self>);
+   |                  --------- help: consider changing method `ptr`'s `self` parameter to be `&self`: `&Self`
+...
+LL |     Ptr(Box::new(4)) as Ptr<dyn Trait>;
+   |                         ^^^^^^^^^^^^^^ `Trait` cannot be made into an object
+   |
+note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+  --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:25:18
+   |
+LL | trait Trait {
+   |       ----- this trait cannot be made into an object...
+LL |     fn ptr(self: Ptr<Self>);
+   |                  ^^^^^^^^^ ...because method `ptr`'s `self` parameter cannot be dispatched on
+
+error[E0038]: the trait `Trait` cannot be made into an object
+  --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:32:5
+   |
+LL |     fn ptr(self: Ptr<Self>);
+   |                  --------- help: consider changing method `ptr`'s `self` parameter to be `&self`: `&Self`
+...
+LL |     Ptr(Box::new(4)) as Ptr<dyn Trait>;
+   |     ^^^^^^^^^^^^^^^^ `Trait` cannot be made into an object
+   |
+note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+  --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:25:18
+   |
+LL | trait Trait {
+   |       ----- this trait cannot be made into an object...
+LL |     fn ptr(self: Ptr<Self>);
+   |                  ^^^^^^^^^ ...because method `ptr`'s `self` parameter cannot be dispatched on
+note: required for `Ptr<{integer}>` to implement `CoerceUnsized<Ptr<dyn Trait>>`
+  --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:20:40
+   |
+LL | impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {}
+   |         ---------                      ^^^^^^^^^^^^^^^^^^^^^     ^^^^^^
+   |         |
+   |         unsatisfied trait bound introduced here
+   = note: required by cast to type `Ptr<dyn Trait>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0038`.
diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs
new file mode 100644
index 00000000000..0467dea621b
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs
@@ -0,0 +1,12 @@
+// check-pass
+
+#![deny(multiple_supertrait_upcastable)]
+//~^ WARNING unknown lint: `multiple_supertrait_upcastable`
+//~| WARNING unknown lint: `multiple_supertrait_upcastable`
+//~| WARNING unknown lint: `multiple_supertrait_upcastable`
+#![warn(multiple_supertrait_upcastable)]
+//~^ WARNING unknown lint: `multiple_supertrait_upcastable`
+//~| WARNING unknown lint: `multiple_supertrait_upcastable`
+//~| WARNING unknown lint: `multiple_supertrait_upcastable`
+
+fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
new file mode 100644
index 00000000000..1f725f35417
--- /dev/null
+++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
@@ -0,0 +1,57 @@
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
+   |
+LL | #![deny(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+   = note: `#[warn(unknown_lints)]` on by default
+
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
+   |
+LL | #![warn(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
+   |
+LL | #![deny(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
+   |
+LL | #![warn(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
+   |
+LL | #![deny(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+
+warning: unknown lint: `multiple_supertrait_upcastable`
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
+   |
+LL | #![warn(multiple_supertrait_upcastable)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `multiple_supertrait_upcastable` lint is unstable
+   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
+
+warning: 6 warnings emitted
+
diff --git a/tests/ui/fmt/ifmt-unimpl.stderr b/tests/ui/fmt/ifmt-unimpl.stderr
index be321c3c5c0..3480a2ec815 100644
--- a/tests/ui/fmt/ifmt-unimpl.stderr
+++ b/tests/ui/fmt/ifmt-unimpl.stderr
@@ -15,7 +15,7 @@ LL |     format!("{:X}", "3");
              NonZeroIsize
            and 21 others
    = note: required for `&str` to implement `UpperHex`
-note: required by a bound in `ArgumentV1::<'a>::new_upper_hex`
+note: required by a bound in `core::fmt::ArgumentV1::<'a>::new_upper_hex`
   --> $SRC_DIR/core/src/fmt/mod.rs:LL:COL
    = note: this error originates in the macro `$crate::__export::format_args` which comes from the expansion of the macro `arg_new` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/tests/ui/fmt/send-sync.stderr b/tests/ui/fmt/send-sync.stderr
index 3ed040c3ab3..d43f4f0d957 100644
--- a/tests/ui/fmt/send-sync.stderr
+++ b/tests/ui/fmt/send-sync.stderr
@@ -6,11 +6,11 @@ LL |     send(format_args!("{:?}", c));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `[ArgumentV1<'_>]`, the trait `Sync` is not implemented for `core::fmt::Opaque`
+   = help: within `[core::fmt::ArgumentV1<'_>]`, the trait `Sync` is not implemented for `core::fmt::Opaque`
    = note: required because it appears within the type `&core::fmt::Opaque`
    = note: required because it appears within the type `ArgumentV1<'_>`
    = note: required because it appears within the type `[ArgumentV1<'_>]`
-   = note: required for `&[ArgumentV1<'_>]` to implement `Send`
+   = note: required for `&[core::fmt::ArgumentV1<'_>]` to implement `Send`
    = note: required because it appears within the type `Arguments<'_>`
 note: required by a bound in `send`
   --> $DIR/send-sync.rs:1:12
diff --git a/tests/ui/fn/fn-compare-mismatch.stderr b/tests/ui/fn/fn-compare-mismatch.stderr
index df838cb1181..b4e71e75fdb 100644
--- a/tests/ui/fn/fn-compare-mismatch.stderr
+++ b/tests/ui/fn/fn-compare-mismatch.stderr
@@ -19,6 +19,8 @@ LL |     let x = f == g;
    |
    = note: expected fn item `fn() {f}`
               found fn item `fn() {g}`
+   = note: different fn items have unique types, even if their signatures are the same
+   = help: consider casting both fn items to fn pointers using `as fn()`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/fn/fn-item-type.rs b/tests/ui/fn/fn-item-type.rs
index 1831e6cbf10..b6ebc867d28 100644
--- a/tests/ui/fn/fn-item-type.rs
+++ b/tests/ui/fn/fn-item-type.rs
@@ -1,13 +1,22 @@
 // Test that the types of distinct fn items are not compatible by
 // default. See also `run-pass/fn-item-type-*.rs`.
 
-fn foo<T>(x: isize) -> isize { x * 2 }
-fn bar<T>(x: isize) -> isize { x * 4 }
+fn foo<T>(x: isize) -> isize {
+    x * 2
+}
+fn bar<T>(x: isize) -> isize {
+    x * 4
+}
 
-fn eq<T>(x: T, y: T) { }
+fn eq<T>(x: T, y: T) {}
 
-trait Foo { fn foo() { /* this is a default fn */ } }
-impl<T> Foo for T { /* `foo` is still default here */ }
+trait Foo {
+    fn foo() { /* this is a default fn */
+    }
+}
+impl<T> Foo for T {
+    /* `foo` is still default here */
+}
 
 fn main() {
     eq(foo::<u8>, bar::<u8>);
@@ -15,39 +24,29 @@ fn main() {
     //~| expected fn item `fn(_) -> _ {foo::<u8>}`
     //~| found fn item `fn(_) -> _ {bar::<u8>}`
     //~| expected fn item, found a different fn item
-    //~| different `fn` items always have unique types, even if their signatures are the same
-    //~| change the expected type to be function pointer
-    //~| if the expected type is due to type inference, cast the expected `fn` to a function pointer
+    //~| different fn items have unique types, even if their signatures are the same
 
     eq(foo::<u8>, foo::<i8>);
     //~^ ERROR mismatched types
     //~| expected `u8`, found `i8`
-    //~| different `fn` items always have unique types, even if their signatures are the same
-    //~| change the expected type to be function pointer
-    //~| if the expected type is due to type inference, cast the expected `fn` to a function pointer
+    //~| different fn items have unique types, even if their signatures are the same
 
     eq(bar::<String>, bar::<Vec<u8>>);
     //~^ ERROR mismatched types
     //~| found fn item `fn(_) -> _ {bar::<Vec<u8>>}`
     //~| expected struct `String`, found struct `Vec`
-    //~| different `fn` items always have unique types, even if their signatures are the same
-    //~| change the expected type to be function pointer
-    //~| if the expected type is due to type inference, cast the expected `fn` to a function pointer
+    //~| different fn items have unique types, even if their signatures are the same
 
     // Make sure we distinguish between trait methods correctly.
     eq(<u8 as Foo>::foo, <u16 as Foo>::foo);
     //~^ ERROR mismatched types
     //~| expected `u8`, found `u16`
-    //~| different `fn` items always have unique types, even if their signatures are the same
-    //~| change the expected type to be function pointer
-    //~| if the expected type is due to type inference, cast the expected `fn` to a function pointer
+    //~| different fn items have unique types, even if their signatures are the same
 
     eq(foo::<u8>, bar::<u8> as fn(isize) -> isize);
     //~^ ERROR mismatched types
     //~| found fn pointer `fn(_) -> _`
     //~| expected fn item, found fn pointer
-    //~| change the expected type to be function pointer
-    //~| if the expected type is due to type inference, cast the expected `fn` to a function pointer
 
     eq(foo::<u8> as fn(isize) -> isize, bar::<u8>); // ok!
 }
diff --git a/tests/ui/fn/fn-item-type.stderr b/tests/ui/fn/fn-item-type.stderr
index f03a47d5c2c..9d41243ef11 100644
--- a/tests/ui/fn/fn-item-type.stderr
+++ b/tests/ui/fn/fn-item-type.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/fn-item-type.rs:13:19
+  --> $DIR/fn-item-type.rs:22:19
    |
 LL |     eq(foo::<u8>, bar::<u8>);
    |     --            ^^^^^^^^^ expected fn item, found a different fn item
@@ -8,17 +8,16 @@ LL |     eq(foo::<u8>, bar::<u8>);
    |
    = note: expected fn item `fn(_) -> _ {foo::<u8>}`
               found fn item `fn(_) -> _ {bar::<u8>}`
-   = note: different `fn` items always have unique types, even if their signatures are the same
-   = help: change the expected type to be function pointer `fn(isize) -> isize`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `foo::<u8> as fn(isize) -> isize`
+   = note: different fn items have unique types, even if their signatures are the same
 note: function defined here
-  --> $DIR/fn-item-type.rs:7:4
+  --> $DIR/fn-item-type.rs:11:4
    |
-LL | fn eq<T>(x: T, y: T) { }
+LL | fn eq<T>(x: T, y: T) {}
    |    ^^          ----
+   = help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-item-type.rs:22:19
+  --> $DIR/fn-item-type.rs:29:19
    |
 LL |     eq(foo::<u8>, foo::<i8>);
    |     --            ^^^^^^^^^ expected `u8`, found `i8`
@@ -27,17 +26,16 @@ LL |     eq(foo::<u8>, foo::<i8>);
    |
    = note: expected fn item `fn(_) -> _ {foo::<u8>}`
               found fn item `fn(_) -> _ {foo::<i8>}`
-   = note: different `fn` items always have unique types, even if their signatures are the same
-   = help: change the expected type to be function pointer `fn(isize) -> isize`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `foo::<u8> as fn(isize) -> isize`
+   = note: different fn items have unique types, even if their signatures are the same
 note: function defined here
-  --> $DIR/fn-item-type.rs:7:4
+  --> $DIR/fn-item-type.rs:11:4
    |
-LL | fn eq<T>(x: T, y: T) { }
+LL | fn eq<T>(x: T, y: T) {}
    |    ^^          ----
+   = help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-item-type.rs:29:23
+  --> $DIR/fn-item-type.rs:34:23
    |
 LL |     eq(bar::<String>, bar::<Vec<u8>>);
    |     --                ^^^^^^^^^^^^^^ expected struct `String`, found struct `Vec`
@@ -46,17 +44,16 @@ LL |     eq(bar::<String>, bar::<Vec<u8>>);
    |
    = note: expected fn item `fn(_) -> _ {bar::<String>}`
               found fn item `fn(_) -> _ {bar::<Vec<u8>>}`
-   = note: different `fn` items always have unique types, even if their signatures are the same
-   = help: change the expected type to be function pointer `fn(isize) -> isize`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `bar::<String> as fn(isize) -> isize`
+   = note: different fn items have unique types, even if their signatures are the same
 note: function defined here
-  --> $DIR/fn-item-type.rs:7:4
+  --> $DIR/fn-item-type.rs:11:4
    |
-LL | fn eq<T>(x: T, y: T) { }
+LL | fn eq<T>(x: T, y: T) {}
    |    ^^          ----
+   = help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-item-type.rs:38:26
+  --> $DIR/fn-item-type.rs:41:26
    |
 LL |     eq(<u8 as Foo>::foo, <u16 as Foo>::foo);
    |     --                   ^^^^^^^^^^^^^^^^^ expected `u8`, found `u16`
@@ -65,17 +62,16 @@ LL |     eq(<u8 as Foo>::foo, <u16 as Foo>::foo);
    |
    = note: expected fn item `fn() {<u8 as Foo>::foo}`
               found fn item `fn() {<u16 as Foo>::foo}`
-   = note: different `fn` items always have unique types, even if their signatures are the same
-   = help: change the expected type to be function pointer `fn()`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `<u8 as Foo>::foo as fn()`
+   = note: different fn items have unique types, even if their signatures are the same
 note: function defined here
-  --> $DIR/fn-item-type.rs:7:4
+  --> $DIR/fn-item-type.rs:11:4
    |
-LL | fn eq<T>(x: T, y: T) { }
+LL | fn eq<T>(x: T, y: T) {}
    |    ^^          ----
+   = help: consider casting both fn items to fn pointers using `as fn()`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-item-type.rs:45:19
+  --> $DIR/fn-item-type.rs:46:19
    |
 LL |     eq(foo::<u8>, bar::<u8> as fn(isize) -> isize);
    |     --            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected fn item, found fn pointer
@@ -84,12 +80,11 @@ LL |     eq(foo::<u8>, bar::<u8> as fn(isize) -> isize);
    |
    = note: expected fn item `fn(_) -> _ {foo::<u8>}`
            found fn pointer `fn(_) -> _`
-   = help: change the expected type to be function pointer `fn(isize) -> isize`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `foo::<u8> as fn(isize) -> isize`
+   = help: consider casting the fn item to a fn pointer: `foo::<u8> as fn(isize) -> isize`
 note: function defined here
-  --> $DIR/fn-item-type.rs:7:4
+  --> $DIR/fn-item-type.rs:11:4
    |
-LL | fn eq<T>(x: T, y: T) { }
+LL | fn eq<T>(x: T, y: T) {}
    |    ^^          ----
 
 error: aborting due to 5 previous errors
diff --git a/tests/ui/fn/fn-pointer-mismatch.rs b/tests/ui/fn/fn-pointer-mismatch.rs
new file mode 100644
index 00000000000..0597478cb42
--- /dev/null
+++ b/tests/ui/fn/fn-pointer-mismatch.rs
@@ -0,0 +1,56 @@
+fn foo(x: u32) -> u32 {
+    x * 2
+}
+
+fn bar(x: u32) -> u32 {
+    x * 3
+}
+
+// original example from Issue #102608
+fn foobar(n: u32) -> u32 {
+    let g = if n % 2 == 0 { &foo } else { &bar };
+    //~^ ERROR `if` and `else` have incompatible types
+    //~| different fn items have unique types, even if their signatures are the same
+    g(n)
+}
+
+fn main() {
+    assert_eq!(foobar(7), 21);
+    assert_eq!(foobar(8), 16);
+
+    // general mismatch of fn item types
+    let mut a = foo;
+    a = bar;
+    //~^ ERROR mismatched types
+    //~| expected fn item `fn(_) -> _ {foo}`
+    //~| found fn item `fn(_) -> _ {bar}`
+    //~| different fn items have unique types, even if their signatures are the same
+
+    // display note even when boxed
+    let mut b = Box::new(foo);
+    b = Box::new(bar);
+    //~^ ERROR mismatched types
+    //~| different fn items have unique types, even if their signatures are the same
+
+    // suggest removing reference
+    let c: fn(u32) -> u32 = &foo;
+    //~^ ERROR mismatched types
+    //~| expected fn pointer `fn(u32) -> u32`
+    //~| found reference `&fn(u32) -> u32 {foo}`
+
+    // suggest using reference
+    let d: &fn(u32) -> u32 = foo;
+    //~^ ERROR mismatched types
+    //~| expected reference `&fn(u32) -> u32`
+    //~| found fn item `fn(u32) -> u32 {foo}`
+
+    // suggest casting with reference
+    let e: &fn(u32) -> u32 = &foo;
+    //~^ ERROR mismatched types
+    //~| expected reference `&fn(u32) -> u32`
+    //~| found reference `&fn(u32) -> u32 {foo}`
+
+    // OK
+    let mut z: fn(u32) -> u32 = foo as fn(u32) -> u32;
+    z = bar;
+}
diff --git a/tests/ui/fn/fn-pointer-mismatch.stderr b/tests/ui/fn/fn-pointer-mismatch.stderr
new file mode 100644
index 00000000000..e0bd60fbc0b
--- /dev/null
+++ b/tests/ui/fn/fn-pointer-mismatch.stderr
@@ -0,0 +1,84 @@
+error[E0308]: `if` and `else` have incompatible types
+  --> $DIR/fn-pointer-mismatch.rs:11:43
+   |
+LL |     let g = if n % 2 == 0 { &foo } else { &bar };
+   |                             ----          ^^^^ expected fn item, found a different fn item
+   |                             |
+   |                             expected because of this
+   |
+   = note: expected reference `&fn(u32) -> u32 {foo}`
+              found reference `&fn(u32) -> u32 {bar}`
+   = note: different fn items have unique types, even if their signatures are the same
+   = help: consider casting both fn items to fn pointers using `as fn(u32) -> u32`
+
+error[E0308]: mismatched types
+  --> $DIR/fn-pointer-mismatch.rs:23:9
+   |
+LL |     let mut a = foo;
+   |                 --- expected due to this value
+LL |     a = bar;
+   |         ^^^ expected fn item, found a different fn item
+   |
+   = note: expected fn item `fn(_) -> _ {foo}`
+              found fn item `fn(_) -> _ {bar}`
+   = note: different fn items have unique types, even if their signatures are the same
+   = help: consider casting both fn items to fn pointers using `as fn(u32) -> u32`
+
+error[E0308]: mismatched types
+  --> $DIR/fn-pointer-mismatch.rs:31:18
+   |
+LL |     b = Box::new(bar);
+   |         -------- ^^^ expected fn item, found a different fn item
+   |         |
+   |         arguments to this function are incorrect
+   |
+   = note: expected fn item `fn(_) -> _ {foo}`
+              found fn item `fn(_) -> _ {bar}`
+   = note: different fn items have unique types, even if their signatures are the same
+note: associated function defined here
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+   = help: consider casting both fn items to fn pointers using `as fn(u32) -> u32`
+
+error[E0308]: mismatched types
+  --> $DIR/fn-pointer-mismatch.rs:36:29
+   |
+LL |     let c: fn(u32) -> u32 = &foo;
+   |            --------------   ^^^^
+   |            |                |
+   |            |                expected fn pointer, found reference
+   |            |                help: consider removing the reference: `foo`
+   |            expected due to this
+   |
+   = note: expected fn pointer `fn(u32) -> u32`
+               found reference `&fn(u32) -> u32 {foo}`
+
+error[E0308]: mismatched types
+  --> $DIR/fn-pointer-mismatch.rs:42:30
+   |
+LL |     let d: &fn(u32) -> u32 = foo;
+   |            ---------------   ^^^
+   |            |                 |
+   |            |                 expected `&fn(u32) -> u32`, found fn item
+   |            |                 help: consider using a reference: `&foo`
+   |            expected due to this
+   |
+   = note: expected reference `&fn(u32) -> u32`
+                found fn item `fn(u32) -> u32 {foo}`
+
+error[E0308]: mismatched types
+  --> $DIR/fn-pointer-mismatch.rs:48:30
+   |
+LL |     let e: &fn(u32) -> u32 = &foo;
+   |            ---------------   ^^^^
+   |            |                 |
+   |            |                 expected fn pointer, found fn item
+   |            |                 help: consider casting to a fn pointer: `&(foo as fn(u32) -> u32)`
+   |            expected due to this
+   |
+   = note: expected reference `&fn(u32) -> u32`
+              found reference `&fn(u32) -> u32 {foo}`
+   = note: fn items are distinct from fn pointers
+
+error: aborting due to 6 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/fn/implied-bounds-unnorm-associated-type-4.stderr b/tests/ui/fn/implied-bounds-unnorm-associated-type-4.stderr
index fcbaa91d19f..4df639232a3 100644
--- a/tests/ui/fn/implied-bounds-unnorm-associated-type-4.stderr
+++ b/tests/ui/fn/implied-bounds-unnorm-associated-type-4.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/implied-bounds-unnorm-associated-type-4.rs:21:10
    |
+LL |     let x = String::from("Hello World!");
+   |         - binding `x` declared here
 LL |     let y = f(&x, ());
    |               -- borrow of `x` occurs here
 LL |     drop(x);
diff --git a/tests/ui/fn/implied-bounds-unnorm-associated-type.stderr b/tests/ui/fn/implied-bounds-unnorm-associated-type.stderr
index e35f46e4439..d417f288393 100644
--- a/tests/ui/fn/implied-bounds-unnorm-associated-type.stderr
+++ b/tests/ui/fn/implied-bounds-unnorm-associated-type.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/implied-bounds-unnorm-associated-type.rs:20:10
    |
+LL |     let x = String::from("Hello World!");
+   |         - binding `x` declared here
 LL |     let y = f(&x, ());
    |               -- borrow of `x` occurs here
 LL |     drop(x);
diff --git a/tests/ui/generator/addassign-yield.rs b/tests/ui/generator/addassign-yield.rs
index 66f22bf31fc..7211367afee 100644
--- a/tests/ui/generator/addassign-yield.rs
+++ b/tests/ui/generator/addassign-yield.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // run-pass
 // Regression test for broken MIR error (#61442)
 // Due to the two possible evaluation orders for
diff --git a/tests/ui/generator/auto-trait-regions.drop_tracking.stderr b/tests/ui/generator/auto-trait-regions.drop_tracking.stderr
new file mode 100644
index 00000000000..165748d4430
--- /dev/null
+++ b/tests/ui/generator/auto-trait-regions.drop_tracking.stderr
@@ -0,0 +1,47 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:24
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                        ^^^^                - temporary value is freed at the end of this statement
+   |                        |
+   |                        creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:35
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                                   ^^^^     - temporary value is freed at the end of this statement
+   |                                   |
+   |                                   creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:34:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `&'0 OnlyFooIfStaticRef` must implement `Foo`, for any lifetime `'0`...
+   = note: ...but `Foo` is actually implemented for the type `&'static OnlyFooIfStaticRef`
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:54:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`...
+   = note: ...but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0716`.
diff --git a/tests/ui/generator/auto-trait-regions.drop_tracking_mir.stderr b/tests/ui/generator/auto-trait-regions.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..165748d4430
--- /dev/null
+++ b/tests/ui/generator/auto-trait-regions.drop_tracking_mir.stderr
@@ -0,0 +1,47 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:24
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                        ^^^^                - temporary value is freed at the end of this statement
+   |                        |
+   |                        creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:35
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                                   ^^^^     - temporary value is freed at the end of this statement
+   |                                   |
+   |                                   creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:34:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `&'0 OnlyFooIfStaticRef` must implement `Foo`, for any lifetime `'0`...
+   = note: ...but `Foo` is actually implemented for the type `&'static OnlyFooIfStaticRef`
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:54:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`...
+   = note: ...but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0716`.
diff --git a/tests/ui/generator/auto-trait-regions.no_drop_tracking.stderr b/tests/ui/generator/auto-trait-regions.no_drop_tracking.stderr
new file mode 100644
index 00000000000..165748d4430
--- /dev/null
+++ b/tests/ui/generator/auto-trait-regions.no_drop_tracking.stderr
@@ -0,0 +1,47 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:24
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                        ^^^^                - temporary value is freed at the end of this statement
+   |                        |
+   |                        creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/auto-trait-regions.rs:48:35
+   |
+LL |         let a = A(&mut true, &mut true, No);
+   |                                   ^^^^     - temporary value is freed at the end of this statement
+   |                                   |
+   |                                   creates a temporary value which is freed while still in use
+...
+LL |         assert_foo(a);
+   |                    - borrow later used here
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:34:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `&'0 OnlyFooIfStaticRef` must implement `Foo`, for any lifetime `'0`...
+   = note: ...but `Foo` is actually implemented for the type `&'static OnlyFooIfStaticRef`
+
+error: implementation of `Foo` is not general enough
+  --> $DIR/auto-trait-regions.rs:54:5
+   |
+LL |     assert_foo(gen);
+   |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
+   |
+   = note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`...
+   = note: ...but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0716`.
diff --git a/tests/ui/generator/auto-trait-regions.rs b/tests/ui/generator/auto-trait-regions.rs
index ea4b0d554cd..fd13e41319f 100644
--- a/tests/ui/generator/auto-trait-regions.rs
+++ b/tests/ui/generator/auto-trait-regions.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(generators)]
 #![feature(auto_traits)]
 #![feature(negative_impls)]
diff --git a/tests/ui/generator/auto-trait-regions.stderr b/tests/ui/generator/auto-trait-regions.stderr
index 0b1f34aeb96..165748d4430 100644
--- a/tests/ui/generator/auto-trait-regions.stderr
+++ b/tests/ui/generator/auto-trait-regions.stderr
@@ -1,5 +1,5 @@
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/auto-trait-regions.rs:45:24
+  --> $DIR/auto-trait-regions.rs:48:24
    |
 LL |         let a = A(&mut true, &mut true, No);
    |                        ^^^^                - temporary value is freed at the end of this statement
@@ -12,7 +12,7 @@ LL |         assert_foo(a);
    = note: consider using a `let` binding to create a longer lived value
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/auto-trait-regions.rs:45:35
+  --> $DIR/auto-trait-regions.rs:48:35
    |
 LL |         let a = A(&mut true, &mut true, No);
    |                                   ^^^^     - temporary value is freed at the end of this statement
@@ -25,7 +25,7 @@ LL |         assert_foo(a);
    = note: consider using a `let` binding to create a longer lived value
 
 error: implementation of `Foo` is not general enough
-  --> $DIR/auto-trait-regions.rs:31:5
+  --> $DIR/auto-trait-regions.rs:34:5
    |
 LL |     assert_foo(gen);
    |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
@@ -34,7 +34,7 @@ LL |     assert_foo(gen);
    = note: ...but `Foo` is actually implemented for the type `&'static OnlyFooIfStaticRef`
 
 error: implementation of `Foo` is not general enough
-  --> $DIR/auto-trait-regions.rs:51:5
+  --> $DIR/auto-trait-regions.rs:54:5
    |
 LL |     assert_foo(gen);
    |     ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
diff --git a/tests/ui/generator/borrowing.drop_tracking.stderr b/tests/ui/generator/borrowing.drop_tracking.stderr
new file mode 100644
index 00000000000..96e3c327f8b
--- /dev/null
+++ b/tests/ui/generator/borrowing.drop_tracking.stderr
@@ -0,0 +1,31 @@
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:13:33
+   |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
+LL |         Pin::new(&mut || yield &a).resume(())
+   |                       --        ^ borrowed value does not live long enough
+   |                       |
+   |                       value captured here by generator
+LL |
+LL |     };
+   |     - `a` dropped here while still borrowed
+
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:20:20
+   |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
+LL |         || {
+   |         -- value captured here by generator
+LL |             yield &a
+   |                    ^ borrowed value does not live long enough
+...
+LL |     };
+   |     - `a` dropped here while still borrowed
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/tests/ui/generator/borrowing.drop_tracking_mir.stderr b/tests/ui/generator/borrowing.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..8fbad276db4
--- /dev/null
+++ b/tests/ui/generator/borrowing.drop_tracking_mir.stderr
@@ -0,0 +1,39 @@
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:13:33
+   |
+LL |         Pin::new(&mut || yield &a).resume(())
+   |                       ----------^
+   |                       |         |
+   |                       |         borrowed value does not live long enough
+   |                       value captured here by generator
+   |                       a temporary with access to the borrow is created here ...
+LL |
+LL |     };
+   |     -- ... and the borrow might be used here, when that temporary is dropped and runs the destructor for generator
+   |     |
+   |     `a` dropped here while still borrowed
+   |
+   = note: the temporary is part of an expression at the end of a block;
+           consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
+help: for example, you could save the expression's value in a new local variable `x` and then make `x` be the expression at the end of the block
+   |
+LL |         let x = Pin::new(&mut || yield &a).resume(()); x
+   |         +++++++                                      +++
+
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:20:20
+   |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
+LL |         || {
+   |         -- value captured here by generator
+LL |             yield &a
+   |                    ^ borrowed value does not live long enough
+...
+LL |     };
+   |     - `a` dropped here while still borrowed
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/tests/ui/generator/borrowing.no_drop_tracking.stderr b/tests/ui/generator/borrowing.no_drop_tracking.stderr
new file mode 100644
index 00000000000..96e3c327f8b
--- /dev/null
+++ b/tests/ui/generator/borrowing.no_drop_tracking.stderr
@@ -0,0 +1,31 @@
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:13:33
+   |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
+LL |         Pin::new(&mut || yield &a).resume(())
+   |                       --        ^ borrowed value does not live long enough
+   |                       |
+   |                       value captured here by generator
+LL |
+LL |     };
+   |     - `a` dropped here while still borrowed
+
+error[E0597]: `a` does not live long enough
+  --> $DIR/borrowing.rs:20:20
+   |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
+LL |         || {
+   |         -- value captured here by generator
+LL |             yield &a
+   |                    ^ borrowed value does not live long enough
+...
+LL |     };
+   |     - `a` dropped here while still borrowed
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/tests/ui/generator/borrowing.rs b/tests/ui/generator/borrowing.rs
index d36592583cd..29f39437f8f 100644
--- a/tests/ui/generator/borrowing.rs
+++ b/tests/ui/generator/borrowing.rs
@@ -1,3 +1,7 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 #![feature(generators, generator_trait)]
 
 use std::ops::Generator;
diff --git a/tests/ui/generator/borrowing.stderr b/tests/ui/generator/borrowing.stderr
index 38e1ace8c4e..96e3c327f8b 100644
--- a/tests/ui/generator/borrowing.stderr
+++ b/tests/ui/generator/borrowing.stderr
@@ -1,5 +1,5 @@
 error[E0597]: `a` does not live long enough
-  --> $DIR/borrowing.rs:9:33
+  --> $DIR/borrowing.rs:13:33
    |
 LL |     let _b = {
    |         -- borrow later stored here
@@ -13,7 +13,7 @@ LL |     };
    |     - `a` dropped here while still borrowed
 
 error[E0597]: `a` does not live long enough
-  --> $DIR/borrowing.rs:16:20
+  --> $DIR/borrowing.rs:20:20
    |
 LL |     let _b = {
    |         -- borrow later stored here
diff --git a/tests/ui/generator/drop-tracking-parent-expression.stderr b/tests/ui/generator/drop-tracking-parent-expression.drop_tracking.stderr
index fbf5d6e0725..c07906ec37d 100644
--- a/tests/ui/generator/drop-tracking-parent-expression.stderr
+++ b/tests/ui/generator/drop-tracking-parent-expression.drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:25
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
    |
 LL |               assert_send(g);
    |                           ^ generator is not `Send`
@@ -13,9 +13,9 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:18:21: 18:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/drop-tracking-parent-expression.rs:22:22
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
    |
 LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
    |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
@@ -34,14 +34,14 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
 note: required by a bound in `assert_send`
-  --> $DIR/drop-tracking-parent-expression.rs:41:19
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
    |
 LL | fn assert_send<T: Send>(_thing: T) {}
    |                   ^^^^ required by this bound in `assert_send`
    = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:25
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
    |
 LL |               assert_send(g);
    |                           ^ generator is not `Send`
@@ -55,9 +55,9 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:18:21: 18:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/drop-tracking-parent-expression.rs:22:22
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
    |
 LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
    |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
@@ -76,14 +76,14 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
 note: required by a bound in `assert_send`
-  --> $DIR/drop-tracking-parent-expression.rs:41:19
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
    |
 LL | fn assert_send<T: Send>(_thing: T) {}
    |                   ^^^^ required by this bound in `assert_send`
    = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:25
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
    |
 LL |               assert_send(g);
    |                           ^ generator is not `Send`
@@ -97,9 +97,9 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:18:21: 18:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/drop-tracking-parent-expression.rs:22:22
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
    |
 LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
    |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
@@ -118,7 +118,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
 note: required by a bound in `assert_send`
-  --> $DIR/drop-tracking-parent-expression.rs:41:19
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
    |
 LL | fn assert_send<T: Send>(_thing: T) {}
    |                   ^^^^ required by this bound in `assert_send`
diff --git a/tests/ui/generator/drop-tracking-parent-expression.drop_tracking_mir.stderr b/tests/ui/generator/drop-tracking-parent-expression.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..35698a98dbd
--- /dev/null
+++ b/tests/ui/generator/drop-tracking-parent-expression.drop_tracking_mir.stderr
@@ -0,0 +1,122 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/generator/drop-tracking-parent-expression.no_drop_tracking.stderr b/tests/ui/generator/drop-tracking-parent-expression.no_drop_tracking.stderr
new file mode 100644
index 00000000000..1a05bfe4f0e
--- /dev/null
+++ b/tests/ui/generator/drop-tracking-parent-expression.no_drop_tracking.stderr
@@ -0,0 +1,334 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `copy::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `copy::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `copy::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `copy::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `derived_drop::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `significant_drop::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/drop-tracking-parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/drop-tracking-parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/drop-tracking-parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/drop-tracking-parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 8 previous errors
+
diff --git a/tests/ui/generator/drop-tracking-parent-expression.rs b/tests/ui/generator/drop-tracking-parent-expression.rs
index d40f1b8f64d..ed9ac6d11ad 100644
--- a/tests/ui/generator/drop-tracking-parent-expression.rs
+++ b/tests/ui/generator/drop-tracking-parent-expression.rs
@@ -1,4 +1,7 @@
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 #![feature(generators, negative_impls, rustc_attrs)]
 
 macro_rules! type_combinations {
@@ -18,13 +21,14 @@ macro_rules! type_combinations {
             let g = move || match drop($name::Client { ..$name::Client::default() }) {
             //~^ `significant_drop::Client` which is not `Send`
             //~| `insignificant_dtor::Client` which is not `Send`
-            //~| `derived_drop::Client` which is not `Send`
+            //[no_drop_tracking,drop_tracking]~| `derived_drop::Client` which is not `Send`
                 _ => yield,
             };
             assert_send(g);
             //~^ ERROR cannot be sent between threads
             //~| ERROR cannot be sent between threads
             //~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
         }
 
         // Simple owned value. This works because the Client is considered moved into `drop`,
@@ -34,6 +38,10 @@ macro_rules! type_combinations {
                 _ => yield,
             };
             assert_send(g);
+            //[no_drop_tracking]~^ ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
         }
     )* }
 }
diff --git a/tests/ui/generator/drop-tracking-yielding-in-match-guards.rs b/tests/ui/generator/drop-tracking-yielding-in-match-guards.rs
index 646365e4359..cbc291701cb 100644
--- a/tests/ui/generator/drop-tracking-yielding-in-match-guards.rs
+++ b/tests/ui/generator/drop-tracking-yielding-in-match-guards.rs
@@ -1,6 +1,8 @@
 // build-pass
 // edition:2018
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 
 #![feature(generators)]
 
diff --git a/tests/ui/generator/dropck.stderr b/tests/ui/generator/dropck.stderr
index 7bb188352d7..b9a3a124acb 100644
--- a/tests/ui/generator/dropck.stderr
+++ b/tests/ui/generator/dropck.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `*cell` does not live long enough
   --> $DIR/dropck.rs:10:40
    |
+LL |     let (mut gen, cell);
+   |                   ---- binding `cell` declared here
+LL |     cell = Box::new(RefCell::new(0));
 LL |     let ref_ = Box::leak(Box::new(Some(cell.borrow_mut())));
    |                                        ^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/generator/issue-105084.drop_tracking_mir.stderr b/tests/ui/generator/issue-105084.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..cfc0cf7cdd7
--- /dev/null
+++ b/tests/ui/generator/issue-105084.drop_tracking_mir.stderr
@@ -0,0 +1,51 @@
+error[E0382]: borrow of moved value: `g`
+  --> $DIR/issue-105084.rs:44:14
+   |
+LL |     let mut g = || {
+   |         ----- move occurs because `g` has type `[generator@$DIR/issue-105084.rs:22:17: 22:19]`, which does not implement the `Copy` trait
+...
+LL |     let mut h = copy(g);
+   |                      - value moved here
+...
+LL |     Pin::new(&mut g).resume(());
+   |              ^^^^^^ value borrowed here after move
+   |
+note: consider changing this parameter type in function `copy` to borrow instead if owning the value isn't necessary
+  --> $DIR/issue-105084.rs:17:21
+   |
+LL | fn copy<T: Copy>(x: T) -> T {
+   |    ----             ^ this parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let mut h = copy(g.clone());
+   |                       ++++++++
+
+error[E0277]: the trait bound `Box<(i32, ())>: Copy` is not satisfied in `[generator@$DIR/issue-105084.rs:22:17: 22:19]`
+  --> $DIR/issue-105084.rs:38:17
+   |
+LL |     let mut g = || {
+   |                 -- within this `[generator@$DIR/issue-105084.rs:22:17: 22:19]`
+...
+LL |     let mut h = copy(g);
+   |                 ^^^^ within `[generator@$DIR/issue-105084.rs:22:17: 22:19]`, the trait `Copy` is not implemented for `Box<(i32, ())>`
+   |
+note: generator does not implement `Copy` as this value is used across a yield
+  --> $DIR/issue-105084.rs:28:25
+   |
+LL |         let t = box (5, yield);
+   |                 --------^^^^^-
+   |                 |       |
+   |                 |       yield occurs here, with `box (5, yield)` maybe used later
+   |                 has type `Box<(i32, ())>` which does not implement `Copy`
+note: required by a bound in `copy`
+  --> $DIR/issue-105084.rs:17:12
+   |
+LL | fn copy<T: Copy>(x: T) -> T {
+   |            ^^^^ required by this bound in `copy`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0382.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/issue-105084.rs b/tests/ui/generator/issue-105084.rs
new file mode 100644
index 00000000000..7c9a97b40a5
--- /dev/null
+++ b/tests/ui/generator/issue-105084.rs
@@ -0,0 +1,49 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// [no_drop_tracking] known-bug: #105084
+// [no_drop_tracking] check-pass
+// [drop_tracking] known-bug: #105084
+// [drop_tracking] check-pass
+
+#![feature(generators)]
+#![feature(generator_clone)]
+#![feature(generator_trait)]
+#![feature(box_syntax)]
+
+use std::ops::Generator;
+use std::pin::Pin;
+
+fn copy<T: Copy>(x: T) -> T {
+    x
+}
+
+fn main() {
+    let mut g = || {
+        // This is desuraged as 4 stages:
+        // - allocate a `*mut u8` with `exchange_malloc`;
+        // - create a Box that is ignored for trait computations;
+        // - compute fields (and yields);
+        // - assign to `t`.
+        let t = box (5, yield);
+        drop(t);
+    };
+
+    // Allocate the temporary box.
+    Pin::new(&mut g).resume(());
+
+    // The temporary box is in generator locals.
+    // As it is not taken into account for trait computation,
+    // the generator is `Copy`.
+    let mut h = copy(g);
+    //[drop_tracking_mir]~^ ERROR the trait bound `Box<(i32, ())>: Copy` is not satisfied in
+
+    // We now have 2 boxes with the same backing allocation:
+    // one inside `g` and one inside `h`.
+    // Proceed and drop `t` in `g`.
+    Pin::new(&mut g).resume(());
+    //[drop_tracking_mir]~^ ERROR borrow of moved value: `g`
+
+    // Proceed and drop `t` in `h` -> double free!
+    Pin::new(&mut h).resume(());
+}
diff --git a/tests/ui/generator/issue-57017.no_drop_tracking.stderr b/tests/ui/generator/issue-57017.no_drop_tracking.stderr
new file mode 100644
index 00000000000..06d2d23b9ef
--- /dev/null
+++ b/tests/ui/generator/issue-57017.no_drop_tracking.stderr
@@ -0,0 +1,248 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:31:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: the trait `Sync` is not implemented for `copy::unsync::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:29:28
+   |
+LL |               let g = move || match drop(&$name::unsync::Client::default()) {
+   |                                          --------------------------------- has type `&copy::unsync::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `&$name::unsync::Client::default()` maybe used later
+LL |               };
+   |               - `&$name::unsync::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:43:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/issue-57017.rs:40:21: 40:28]`, the trait `Send` is not implemented for `copy::unsend::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:41:28
+   |
+LL |               let g = move || match drop($name::unsend::Client::default()) {
+   |                                          -------------------------------- has type `copy::unsend::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `$name::unsend::Client::default()` maybe used later
+LL |               };
+   |               - `$name::unsend::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:31:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: the trait `Sync` is not implemented for `derived_drop::unsync::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:29:28
+   |
+LL |               let g = move || match drop(&$name::unsync::Client::default()) {
+   |                                          --------------------------------- has type `&derived_drop::unsync::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `&$name::unsync::Client::default()` maybe used later
+LL |               };
+   |               - `&$name::unsync::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:43:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/issue-57017.rs:40:21: 40:28]`, the trait `Send` is not implemented for `derived_drop::unsend::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:41:28
+   |
+LL |               let g = move || match drop($name::unsend::Client::default()) {
+   |                                          -------------------------------- has type `derived_drop::unsend::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `$name::unsend::Client::default()` maybe used later
+LL |               };
+   |               - `$name::unsend::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:31:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: the trait `Sync` is not implemented for `significant_drop::unsync::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:29:28
+   |
+LL |               let g = move || match drop(&$name::unsync::Client::default()) {
+   |                                          --------------------------------- has type `&significant_drop::unsync::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `&$name::unsync::Client::default()` maybe used later
+LL |               };
+   |               - `&$name::unsync::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57017.rs:43:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/issue-57017.rs:40:21: 40:28]`, the trait `Send` is not implemented for `significant_drop::unsend::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57017.rs:41:28
+   |
+LL |               let g = move || match drop($name::unsend::Client::default()) {
+   |                                          -------------------------------- has type `significant_drop::unsend::Client` which is not `Send`
+LL |                   _status => yield,
+   |                              ^^^^^ yield occurs here, with `$name::unsend::Client::default()` maybe used later
+LL |               };
+   |               - `$name::unsend::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+LL | |         significant_drop => {
+...  |
+LL | |         }
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57017.rs:51:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 6 previous errors
+
diff --git a/tests/ui/generator/issue-57017.rs b/tests/ui/generator/issue-57017.rs
index c0bde3b4473..03b00ac99ad 100644
--- a/tests/ui/generator/issue-57017.rs
+++ b/tests/ui/generator/issue-57017.rs
@@ -1,5 +1,9 @@
-// build-pass
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// [drop_tracking] build-pass
+// [drop_tracking_mir] build-pass
+
 #![feature(generators, negative_impls)]
 
 macro_rules! type_combinations {
@@ -25,6 +29,9 @@ macro_rules! type_combinations {
                 _status => yield,
             };
             assert_send(g);
+            //[no_drop_tracking]~^ ERROR generator cannot be sent between threads safely
+            //[no_drop_tracking]~| ERROR generator cannot be sent between threads safely
+            //[no_drop_tracking]~| ERROR generator cannot be sent between threads safely
         }
 
         // This tests that `Client` is properly considered to be dropped after moving it into the
@@ -34,6 +41,9 @@ macro_rules! type_combinations {
                 _status => yield,
             };
             assert_send(g);
+            //[no_drop_tracking]~^ ERROR generator cannot be sent between threads safely
+            //[no_drop_tracking]~| ERROR generator cannot be sent between threads safely
+            //[no_drop_tracking]~| ERROR generator cannot be sent between threads safely
         }
     )* }
 }
diff --git a/tests/ui/generator/issue-57478.no_drop_tracking.stderr b/tests/ui/generator/issue-57478.no_drop_tracking.stderr
new file mode 100644
index 00000000000..612dd9c37f7
--- /dev/null
+++ b/tests/ui/generator/issue-57478.no_drop_tracking.stderr
@@ -0,0 +1,31 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-57478.rs:13:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let guard = Foo;
+LL | |         drop(guard);
+LL | |         yield;
+LL | |     })
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/issue-57478.rs:13:17: 13:19]`, the trait `Send` is not implemented for `Foo`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-57478.rs:17:9
+   |
+LL |         let guard = Foo;
+   |             ----- has type `Foo` which is not `Send`
+LL |         drop(guard);
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `guard` maybe used later
+LL |     })
+   |     - `guard` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/issue-57478.rs:21:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/generator/issue-57478.rs b/tests/ui/generator/issue-57478.rs
index 91407ea1844..3c23b599271 100644
--- a/tests/ui/generator/issue-57478.rs
+++ b/tests/ui/generator/issue-57478.rs
@@ -1,5 +1,8 @@
-// check-pass
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// [drop_tracking] check-pass
+// [drop_tracking_mir] check-pass
 
 #![feature(negative_impls, generators)]
 
@@ -8,6 +11,7 @@ impl !Send for Foo {}
 
 fn main() {
     assert_send(|| {
+        //[no_drop_tracking]~^ ERROR generator cannot be sent between threads safely
         let guard = Foo;
         drop(guard);
         yield;
diff --git a/tests/ui/generator/issue-68112.stderr b/tests/ui/generator/issue-68112.drop_tracking.stderr
index eb99d42c920..282eac1b686 100644
--- a/tests/ui/generator/issue-68112.stderr
+++ b/tests/ui/generator/issue-68112.drop_tracking.stderr
@@ -1,12 +1,13 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/issue-68112.rs:40:18
+  --> $DIR/issue-68112.rs:43:18
    |
 LL |     require_send(send_gen);
    |                  ^^^^^^^^ generator is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/issue-68112.rs:36:9
+  --> $DIR/issue-68112.rs:39:9
    |
 LL |         let _non_send_gen = make_non_send_generator();
    |             ------------- has type `impl Generator<Return = Arc<RefCell<i32>>>` which is not `Send`
@@ -17,13 +18,13 @@ LL |         yield;
 LL |     };
    |     - `_non_send_gen` is later dropped here
 note: required by a bound in `require_send`
-  --> $DIR/issue-68112.rs:22:25
+  --> $DIR/issue-68112.rs:25:25
    |
 LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error[E0277]: `RefCell<i32>` cannot be shared between threads safely
-  --> $DIR/issue-68112.rs:63:18
+  --> $DIR/issue-68112.rs:67:18
    |
 LL |     require_send(send_gen);
    |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
@@ -31,30 +32,31 @@ LL |     require_send(send_gen);
    |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this generator
-  --> $DIR/issue-68112.rs:48:5
+  --> $DIR/issue-68112.rs:52:5
    |
 LL |     || {
    |     ^^
 note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
-  --> $DIR/issue-68112.rs:45:30
+  --> $DIR/issue-68112.rs:49:30
    |
 LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
-  --> $DIR/issue-68112.rs:53:34
+  --> $DIR/issue-68112.rs:57:34
    |
 LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: required because it captures the following types: `impl Generator<Return = Arc<RefCell<i32>>>`, `()`
 note: required because it's used within this generator
-  --> $DIR/issue-68112.rs:59:20
+  --> $DIR/issue-68112.rs:63:20
    |
 LL |     let send_gen = || {
    |                    ^^
 note: required by a bound in `require_send`
-  --> $DIR/issue-68112.rs:22:25
+  --> $DIR/issue-68112.rs:25:25
    |
 LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
diff --git a/tests/ui/generator/issue-68112.drop_tracking_mir.stderr b/tests/ui/generator/issue-68112.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..a83522b714d
--- /dev/null
+++ b/tests/ui/generator/issue-68112.drop_tracking_mir.stderr
@@ -0,0 +1,61 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-68112.rs:43:5
+   |
+LL |     require_send(send_gen);
+   |     ^^^^^^^^^^^^ generator is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-68112.rs:39:9
+   |
+LL |         let _non_send_gen = make_non_send_generator();
+   |             ------------- has type `impl Generator<Return = Arc<RefCell<i32>>>` which is not `Send`
+LL |
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `_non_send_gen` maybe used later
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:25:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error[E0277]: `RefCell<i32>` cannot be shared between threads safely
+  --> $DIR/issue-68112.rs:67:5
+   |
+LL |     require_send(send_gen);
+   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+   = note: required for `Arc<RefCell<i32>>` to implement `Send`
+note: required because it's used within this generator
+  --> $DIR/issue-68112.rs:52:5
+   |
+LL |     || {
+   |     ^^
+note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
+  --> $DIR/issue-68112.rs:49:30
+   |
+LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
+  --> $DIR/issue-68112.rs:57:34
+   |
+LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: required because it captures the following types: `impl Generator<Return = Arc<RefCell<i32>>>`
+note: required because it's used within this generator
+  --> $DIR/issue-68112.rs:63:20
+   |
+LL |     let send_gen = || {
+   |                    ^^
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:25:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/issue-68112.no_drop_tracking.stderr b/tests/ui/generator/issue-68112.no_drop_tracking.stderr
new file mode 100644
index 00000000000..282eac1b686
--- /dev/null
+++ b/tests/ui/generator/issue-68112.no_drop_tracking.stderr
@@ -0,0 +1,66 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/issue-68112.rs:43:18
+   |
+LL |     require_send(send_gen);
+   |                  ^^^^^^^^ generator is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/issue-68112.rs:39:9
+   |
+LL |         let _non_send_gen = make_non_send_generator();
+   |             ------------- has type `impl Generator<Return = Arc<RefCell<i32>>>` which is not `Send`
+LL |
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `_non_send_gen` maybe used later
+...
+LL |     };
+   |     - `_non_send_gen` is later dropped here
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:25:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error[E0277]: `RefCell<i32>` cannot be shared between threads safely
+  --> $DIR/issue-68112.rs:67:18
+   |
+LL |     require_send(send_gen);
+   |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+   = note: required for `Arc<RefCell<i32>>` to implement `Send`
+note: required because it's used within this generator
+  --> $DIR/issue-68112.rs:52:5
+   |
+LL |     || {
+   |     ^^
+note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
+  --> $DIR/issue-68112.rs:49:30
+   |
+LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: required because it appears within the type `impl Generator<Return = Arc<RefCell<i32>>>`
+  --> $DIR/issue-68112.rs:57:34
+   |
+LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: required because it captures the following types: `impl Generator<Return = Arc<RefCell<i32>>>`, `()`
+note: required because it's used within this generator
+  --> $DIR/issue-68112.rs:63:20
+   |
+LL |     let send_gen = || {
+   |                    ^^
+note: required by a bound in `require_send`
+  --> $DIR/issue-68112.rs:25:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/issue-68112.rs b/tests/ui/generator/issue-68112.rs
index 21026f45cb8..48b53b7693d 100644
--- a/tests/ui/generator/issue-68112.rs
+++ b/tests/ui/generator/issue-68112.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(generators, generator_trait)]
 
 use std::{
@@ -8,7 +11,7 @@ use std::{
 };
 
 pub struct Ready<T>(Option<T>);
-impl<T> Generator<()> for Ready<T> {
+impl<T: Unpin> Generator<()> for Ready<T> {
     type Return = T;
     type Yield = ();
     fn resume(mut self: Pin<&mut Self>, _args: ()) -> GeneratorState<(), T> {
@@ -36,10 +39,11 @@ fn test1() {
         yield;
         //~^ NOTE yield occurs here
         //~| NOTE value is used across a yield
-    }; //~ NOTE later dropped here
+    }; //[no_drop_tracking,drop_tracking]~ NOTE later dropped here
     require_send(send_gen);
     //~^ ERROR generator cannot be sent between threads
     //~| NOTE not `Send`
+    //~| NOTE use `std::sync::RwLock` instead
 }
 
 pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
@@ -64,8 +68,9 @@ fn test2() {
     //~^ ERROR `RefCell<i32>` cannot be shared between threads safely
     //~| NOTE `RefCell<i32>` cannot be shared between threads safely
     //~| NOTE required for
-    //~| NOTE required by a bound introduced by this call
+    //[no_drop_tracking,drop_tracking]~| NOTE required by a bound introduced by this call
     //~| NOTE captures the following types
+    //~| NOTE use `std::sync::RwLock` instead
 }
 
 fn main() {}
diff --git a/tests/ui/generator/issue-93161.rs b/tests/ui/generator/issue-93161.rs
index 92305609c83..8d3f7c62f39 100644
--- a/tests/ui/generator/issue-93161.rs
+++ b/tests/ui/generator/issue-93161.rs
@@ -1,6 +1,8 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2021
 // run-pass
-// compile-flags: -Zdrop-tracking
 
 #![feature(never_type)]
 
diff --git a/tests/ui/generator/not-send-sync.drop_tracking.stderr b/tests/ui/generator/not-send-sync.drop_tracking.stderr
new file mode 100644
index 00000000000..718fd42245a
--- /dev/null
+++ b/tests/ui/generator/not-send-sync.drop_tracking.stderr
@@ -0,0 +1,60 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/not-send-sync.rs:17:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSync;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Sync`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:17:17: 17:19]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:20:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_sync`
+  --> $DIR/not-send-sync.rs:14:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/not-send-sync.rs:24:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSend;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:24:17: 24:19]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:27:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/not-send-sync.rs:15:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/not-send-sync.drop_tracking_mir.stderr b/tests/ui/generator/not-send-sync.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..66f01ae37d8
--- /dev/null
+++ b/tests/ui/generator/not-send-sync.drop_tracking_mir.stderr
@@ -0,0 +1,42 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/not-send-sync.rs:17:5
+   |
+LL |     assert_sync(|| {
+   |     ^^^^^^^^^^^ generator is not `Sync`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:17:17: 17:19]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:20:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+note: required by a bound in `assert_sync`
+  --> $DIR/not-send-sync.rs:14:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/not-send-sync.rs:24:5
+   |
+LL |     assert_send(|| {
+   |     ^^^^^^^^^^^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:24:17: 24:19]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:27:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/not-send-sync.rs:15:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/not-send-sync.no_drop_tracking.stderr b/tests/ui/generator/not-send-sync.no_drop_tracking.stderr
new file mode 100644
index 00000000000..718fd42245a
--- /dev/null
+++ b/tests/ui/generator/not-send-sync.no_drop_tracking.stderr
@@ -0,0 +1,60 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/not-send-sync.rs:17:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSync;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Sync`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:17:17: 17:19]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:20:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_sync`
+  --> $DIR/not-send-sync.rs:14:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/not-send-sync.rs:24:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSend;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/not-send-sync.rs:24:17: 24:19]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/not-send-sync.rs:27:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/not-send-sync.rs:15:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/not-send-sync.rs b/tests/ui/generator/not-send-sync.rs
index 8ca5565fb2a..8794db452b4 100644
--- a/tests/ui/generator/not-send-sync.rs
+++ b/tests/ui/generator/not-send-sync.rs
@@ -1,6 +1,14 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 #![feature(generators)]
+#![feature(negative_impls)]
 
-use std::cell::Cell;
+struct NotSend;
+struct NotSync;
+
+impl !Send for NotSend {}
+impl !Sync for NotSync {}
 
 fn main() {
     fn assert_sync<T: Sync>(_: T) {}
@@ -8,14 +16,15 @@ fn main() {
 
     assert_sync(|| {
         //~^ ERROR: generator cannot be shared between threads safely
-        let a = Cell::new(2);
+        let a = NotSync;
         yield;
+        drop(a);
     });
 
-    let a = Cell::new(2);
     assert_send(|| {
-        //~^ ERROR: E0277
-        drop(&a);
+        //~^ ERROR: generator cannot be sent between threads safely
+        let a = NotSend;
         yield;
+        drop(a);
     });
 }
diff --git a/tests/ui/generator/not-send-sync.stderr b/tests/ui/generator/not-send-sync.stderr
deleted file mode 100644
index a821c57b923..00000000000
--- a/tests/ui/generator/not-send-sync.stderr
+++ /dev/null
@@ -1,56 +0,0 @@
-error[E0277]: `Cell<i32>` cannot be shared between threads safely
-  --> $DIR/not-send-sync.rs:16:17
-   |
-LL |       assert_send(|| {
-   |  _____-----------_^
-   | |     |
-   | |     required by a bound introduced by this call
-LL | |
-LL | |         drop(&a);
-LL | |         yield;
-LL | |     });
-   | |_____^ `Cell<i32>` cannot be shared between threads safely
-   |
-   = help: the trait `Sync` is not implemented for `Cell<i32>`
-   = note: required for `&Cell<i32>` to implement `Send`
-note: required because it's used within this generator
-  --> $DIR/not-send-sync.rs:16:17
-   |
-LL |     assert_send(|| {
-   |                 ^^
-note: required by a bound in `assert_send`
-  --> $DIR/not-send-sync.rs:7:23
-   |
-LL |     fn assert_send<T: Send>(_: T) {}
-   |                       ^^^^ required by this bound in `assert_send`
-
-error: generator cannot be shared between threads safely
-  --> $DIR/not-send-sync.rs:9:17
-   |
-LL |       assert_sync(|| {
-   |  _________________^
-LL | |
-LL | |         let a = Cell::new(2);
-LL | |         yield;
-LL | |     });
-   | |_____^ generator is not `Sync`
-   |
-   = help: within `[generator@$DIR/not-send-sync.rs:9:17: 9:19]`, the trait `Sync` is not implemented for `Cell<i32>`
-note: generator is not `Sync` as this value is used across a yield
-  --> $DIR/not-send-sync.rs:12:9
-   |
-LL |         let a = Cell::new(2);
-   |             - has type `Cell<i32>` which is not `Sync`
-LL |         yield;
-   |         ^^^^^ yield occurs here, with `a` maybe used later
-LL |     });
-   |     - `a` is later dropped here
-note: required by a bound in `assert_sync`
-  --> $DIR/not-send-sync.rs:6:23
-   |
-LL |     fn assert_sync<T: Sync>(_: T) {}
-   |                       ^^^^ required by this bound in `assert_sync`
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/parent-expression.drop_tracking.stderr b/tests/ui/generator/parent-expression.drop_tracking.stderr
new file mode 100644
index 00000000000..ef489088bf8
--- /dev/null
+++ b/tests/ui/generator/parent-expression.drop_tracking.stderr
@@ -0,0 +1,128 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/generator/parent-expression.drop_tracking_mir.stderr b/tests/ui/generator/parent-expression.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..bf814456427
--- /dev/null
+++ b/tests/ui/generator/parent-expression.drop_tracking_mir.stderr
@@ -0,0 +1,122 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:13
+   |
+LL |               assert_send(g);
+   |               ^^^^^^^^^^^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/generator/parent-expression.no_drop_tracking.stderr b/tests/ui/generator/parent-expression.no_drop_tracking.stderr
new file mode 100644
index 00000000000..2e1313a8004
--- /dev/null
+++ b/tests/ui/generator/parent-expression.no_drop_tracking.stderr
@@ -0,0 +1,334 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `copy::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `copy::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `copy::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `copy::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `derived_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `derived_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `derived_drop::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `significant_drop::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `significant_drop::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `significant_drop::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:27:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:21:21: 21:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:25:22
+   |
+LL |               let g = move || match drop($name::Client { ..$name::Client::default() }) {
+   |                                                            ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+...
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: generator cannot be sent between threads safely
+  --> $DIR/parent-expression.rs:40:25
+   |
+LL |               assert_send(g);
+   |                           ^ generator is not `Send`
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+   |
+   = help: within `[generator@$DIR/parent-expression.rs:37:21: 37:28]`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/parent-expression.rs:38:22
+   |
+LL |               let g = move || match drop($name::Client::default()) {
+   |                                          ------------------------ has type `insignificant_dtor::Client` which is not `Send`
+LL |                   _ => yield,
+   |                        ^^^^^ yield occurs here, with `$name::Client::default()` maybe used later
+LL |               };
+   |               - `$name::Client::default()` is later dropped here
+...
+LL | /     type_combinations!(
+LL | |         // OK
+LL | |         copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+LL | |         // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+...  |
+LL | |         };
+LL | |     );
+   | |_____- in this macro invocation
+note: required by a bound in `assert_send`
+  --> $DIR/parent-expression.rs:49:19
+   |
+LL | fn assert_send<T: Send>(_thing: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+   = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 8 previous errors
+
diff --git a/tests/ui/generator/parent-expression.rs b/tests/ui/generator/parent-expression.rs
new file mode 100644
index 00000000000..239034e3d4e
--- /dev/null
+++ b/tests/ui/generator/parent-expression.rs
@@ -0,0 +1,77 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
+#![feature(generators, negative_impls, rustc_attrs)]
+
+macro_rules! type_combinations {
+    (
+        $( $name:ident => { $( $tt:tt )* } );* $(;)?
+    ) => { $(
+        mod $name {
+            $( $tt )*
+
+            impl !Sync for Client {}
+            impl !Send for Client {}
+        }
+
+        // Struct update syntax. This fails because the Client used in the update is considered
+        // dropped *after* the yield.
+        {
+            let g = move || match drop($name::Client { ..$name::Client::default() }) {
+            //~^ `significant_drop::Client` which is not `Send`
+            //~| `insignificant_dtor::Client` which is not `Send`
+            //~| `derived_drop::Client` which is not `Send`
+                _ => yield,
+            };
+            assert_send(g);
+            //~^ ERROR cannot be sent between threads
+            //~| ERROR cannot be sent between threads
+            //~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~^^^^ ERROR cannot be sent between threads
+        }
+
+        // Simple owned value. This works because the Client is considered moved into `drop`,
+        // even though the temporary expression doesn't end until after the yield.
+        {
+            let g = move || match drop($name::Client::default()) {
+                _ => yield,
+            };
+            assert_send(g);
+            //[no_drop_tracking]~^ ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
+            //[no_drop_tracking]~| ERROR cannot be sent between threads
+        }
+    )* }
+}
+
+fn assert_send<T: Send>(_thing: T) {}
+
+fn main() {
+    type_combinations!(
+        // OK
+        copy => { #[derive(Copy, Clone, Default)] pub struct Client; };
+        // NOT OK: MIR borrowck thinks that this is used after the yield, even though
+        // this has no `Drop` impl and only the drops of the fields are observable.
+        // FIXME: this should compile.
+        derived_drop => { #[derive(Default)] pub struct Client { pub nickname: String } };
+        // NOT OK
+        significant_drop => {
+            #[derive(Default)]
+            pub struct Client;
+            impl Drop for Client {
+                fn drop(&mut self) {}
+            }
+        };
+        // NOT OK (we need to agree with MIR borrowck)
+        insignificant_dtor => {
+            #[derive(Default)]
+            #[rustc_insignificant_dtor]
+            pub struct Client;
+            impl Drop for Client {
+                fn drop(&mut self) {}
+            }
+        };
+    );
+}
diff --git a/tests/ui/generator/partial-drop.stderr b/tests/ui/generator/partial-drop.drop_tracking.stderr
index 9baafe54e84..f1b25cb8c34 100644
--- a/tests/ui/generator/partial-drop.stderr
+++ b/tests/ui/generator/partial-drop.drop_tracking.stderr
@@ -1,19 +1,18 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:14:17
+  --> $DIR/partial-drop.rs:17:17
    |
 LL |       assert_send(|| {
    |  _________________^
 LL | |
-LL | |         // FIXME: it would be nice to make this work.
 LL | |         let guard = Bar { foo: Foo, x: 42 };
 LL | |         drop(guard.foo);
 LL | |         yield;
 LL | |     });
    | |_____^ generator is not `Send`
    |
-   = help: within `[generator@$DIR/partial-drop.rs:14:17: 14:19]`, the trait `Send` is not implemented for `Foo`
+   = help: within `[generator@$DIR/partial-drop.rs:17:17: 17:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/partial-drop.rs:19:9
+  --> $DIR/partial-drop.rs:21:9
    |
 LL |         let guard = Bar { foo: Foo, x: 42 };
    |             ----- has type `Bar` which is not `Send`
@@ -23,25 +22,25 @@ LL |         yield;
 LL |     });
    |     - `guard` is later dropped here
 note: required by a bound in `assert_send`
-  --> $DIR/partial-drop.rs:42:19
+  --> $DIR/partial-drop.rs:33:19
    |
 LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
 
 error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:22:17
+  --> $DIR/partial-drop.rs:24:17
    |
 LL |       assert_send(|| {
    |  _________________^
 LL | |
-LL | |         // FIXME: it would be nice to make this work.
 LL | |         let guard = Bar { foo: Foo, x: 42 };
-...  |
+LL | |         let Bar { foo, x } = guard;
+LL | |         drop(foo);
 LL | |         yield;
 LL | |     });
    | |_____^ generator is not `Send`
    |
-   = help: within `[generator@$DIR/partial-drop.rs:22:17: 22:19]`, the trait `Send` is not implemented for `Foo`
+   = help: within `[generator@$DIR/partial-drop.rs:24:17: 24:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
   --> $DIR/partial-drop.rs:29:9
    |
@@ -53,40 +52,10 @@ LL |         yield;
 LL |     });
    |     - `guard` is later dropped here
 note: required by a bound in `assert_send`
-  --> $DIR/partial-drop.rs:42:19
+  --> $DIR/partial-drop.rs:33:19
    |
 LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
 
-error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:32:17
-   |
-LL |       assert_send(|| {
-   |  _________________^
-LL | |
-LL | |         // FIXME: it would be nice to make this work.
-LL | |         let guard = Bar { foo: Foo, x: 42 };
-...  |
-LL | |         yield;
-LL | |     });
-   | |_____^ generator is not `Send`
-   |
-   = help: within `[generator@$DIR/partial-drop.rs:32:17: 32:19]`, the trait `Send` is not implemented for `Foo`
-note: generator is not `Send` as this value is used across a yield
-  --> $DIR/partial-drop.rs:38:9
-   |
-LL |         let guard = Bar { foo: Foo, x: 42 };
-   |             ----- has type `Bar` which is not `Send`
-...
-LL |         yield;
-   |         ^^^^^ yield occurs here, with `guard` maybe used later
-LL |     });
-   |     - `guard` is later dropped here
-note: required by a bound in `assert_send`
-  --> $DIR/partial-drop.rs:42:19
-   |
-LL | fn assert_send<T: Send>(_: T) {}
-   |                   ^^^^ required by this bound in `assert_send`
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
diff --git a/tests/ui/generator/partial-drop.no_drop_tracking.stderr b/tests/ui/generator/partial-drop.no_drop_tracking.stderr
new file mode 100644
index 00000000000..91152b5ea6f
--- /dev/null
+++ b/tests/ui/generator/partial-drop.no_drop_tracking.stderr
@@ -0,0 +1,61 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/partial-drop.rs:17:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let guard = Bar { foo: Foo, x: 42 };
+LL | |         drop(guard.foo);
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/partial-drop.rs:17:17: 17:19]`, the trait `Send` is not implemented for `Foo`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/partial-drop.rs:21:9
+   |
+LL |         let guard = Bar { foo: Foo, x: 42 };
+   |             ----- has type `Bar` which is not `Send`
+LL |         drop(guard.foo);
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `guard` maybe used later
+LL |     });
+   |     - `guard` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/partial-drop.rs:33:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/partial-drop.rs:24:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let guard = Bar { foo: Foo, x: 42 };
+LL | |         let Bar { foo, x } = guard;
+LL | |         drop(foo);
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[generator@$DIR/partial-drop.rs:24:17: 24:19]`, the trait `Send` is not implemented for `Foo`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/partial-drop.rs:29:9
+   |
+LL |         let Bar { foo, x } = guard;
+   |                   --- has type `Foo` which is not `Send`
+LL |         drop(foo);
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `foo` maybe used later
+LL |     });
+   |     - `foo` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/partial-drop.rs:33:19
+   |
+LL | fn assert_send<T: Send>(_: T) {}
+   |                   ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/partial-drop.rs b/tests/ui/generator/partial-drop.rs
index c872fb7f3e6..1d3ae075d43 100644
--- a/tests/ui/generator/partial-drop.rs
+++ b/tests/ui/generator/partial-drop.rs
@@ -1,4 +1,7 @@
-// compile-flags: -Zdrop-tracking
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+// [drop_tracking_mir] check-pass
 
 #![feature(negative_impls, generators)]
 
@@ -12,26 +15,14 @@ struct Bar {
 
 fn main() {
     assert_send(|| {
-        //~^ ERROR generator cannot be sent between threads safely
-        // FIXME: it would be nice to make this work.
+        //[no_drop_tracking,drop_tracking]~^ ERROR generator cannot be sent between threads safely
         let guard = Bar { foo: Foo, x: 42 };
         drop(guard.foo);
         yield;
     });
 
     assert_send(|| {
-        //~^ ERROR generator cannot be sent between threads safely
-        // FIXME: it would be nice to make this work.
-        let guard = Bar { foo: Foo, x: 42 };
-        drop(guard);
-        guard.foo = Foo;
-        guard.x = 23;
-        yield;
-    });
-
-    assert_send(|| {
-        //~^ ERROR generator cannot be sent between threads safely
-        // FIXME: it would be nice to make this work.
+        //[no_drop_tracking,drop_tracking]~^ ERROR generator cannot be sent between threads safely
         let guard = Bar { foo: Foo, x: 42 };
         let Bar { foo, x } = guard;
         drop(foo);
diff --git a/tests/ui/generator/print/generator-print-verbose-1.stderr b/tests/ui/generator/print/generator-print-verbose-1.drop_tracking.stderr
index ebf35be581c..7d0a201699b 100644
--- a/tests/ui/generator/print/generator-print-verbose-1.stderr
+++ b/tests/ui/generator/print/generator-print-verbose-1.drop_tracking.stderr
@@ -1,12 +1,13 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/generator-print-verbose-1.rs:37:18
+  --> $DIR/generator-print-verbose-1.rs:40:18
    |
 LL |     require_send(send_gen);
    |                  ^^^^^^^^ generator is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: generator is not `Send` as this value is used across a yield
-  --> $DIR/generator-print-verbose-1.rs:35:9
+  --> $DIR/generator-print-verbose-1.rs:38:9
    |
 LL |         let _non_send_gen = make_non_send_generator();
    |             ------------- has type `Opaque(DefId(0:34 ~ generator_print_verbose_1[749a]::make_non_send_generator::{opaque#0}), [])` which is not `Send`
@@ -15,13 +16,13 @@ LL |         yield;
 LL |     };
    |     - `_non_send_gen` is later dropped here
 note: required by a bound in `require_send`
-  --> $DIR/generator-print-verbose-1.rs:26:25
+  --> $DIR/generator-print-verbose-1.rs:29:25
    |
 LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error[E0277]: `RefCell<i32>` cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-1.rs:56:18
+  --> $DIR/generator-print-verbose-1.rs:59:18
    |
 LL |     require_send(send_gen);
    |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
@@ -29,30 +30,31 @@ LL |     require_send(send_gen);
    |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this generator
-  --> $DIR/generator-print-verbose-1.rs:42:5
+  --> $DIR/generator-print-verbose-1.rs:45:5
    |
 LL |     || {
    |     ^^
 note: required because it appears within the type `Opaque(DefId(0:35 ~ generator_print_verbose_1[749a]::make_gen2::{opaque#0}), [Arc<RefCell<i32>>])`
-  --> $DIR/generator-print-verbose-1.rs:41:30
+  --> $DIR/generator-print-verbose-1.rs:44:30
    |
 LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: required because it appears within the type `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`
-  --> $DIR/generator-print-verbose-1.rs:47:34
+  --> $DIR/generator-print-verbose-1.rs:50:34
    |
 LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: required because it captures the following types: `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`, `()`
 note: required because it's used within this generator
-  --> $DIR/generator-print-verbose-1.rs:52:20
+  --> $DIR/generator-print-verbose-1.rs:55:20
    |
 LL |     let send_gen = || {
    |                    ^^
 note: required by a bound in `require_send`
-  --> $DIR/generator-print-verbose-1.rs:26:25
+  --> $DIR/generator-print-verbose-1.rs:29:25
    |
 LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
diff --git a/tests/ui/generator/print/generator-print-verbose-1.drop_tracking_mir.stderr b/tests/ui/generator/print/generator-print-verbose-1.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..c045b1441c1
--- /dev/null
+++ b/tests/ui/generator/print/generator-print-verbose-1.drop_tracking_mir.stderr
@@ -0,0 +1,60 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/generator-print-verbose-1.rs:40:5
+   |
+LL |     require_send(send_gen);
+   |     ^^^^^^^^^^^^ generator is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/generator-print-verbose-1.rs:38:9
+   |
+LL |         let _non_send_gen = make_non_send_generator();
+   |             ------------- has type `Opaque(DefId(0:34 ~ generator_print_verbose_1[749a]::make_non_send_generator::{opaque#0}), [])` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `_non_send_gen` maybe used later
+note: required by a bound in `require_send`
+  --> $DIR/generator-print-verbose-1.rs:29:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error[E0277]: `RefCell<i32>` cannot be shared between threads safely
+  --> $DIR/generator-print-verbose-1.rs:59:5
+   |
+LL |     require_send(send_gen);
+   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+   = note: required for `Arc<RefCell<i32>>` to implement `Send`
+note: required because it's used within this generator
+  --> $DIR/generator-print-verbose-1.rs:45:5
+   |
+LL |     || {
+   |     ^^
+note: required because it appears within the type `Opaque(DefId(0:35 ~ generator_print_verbose_1[749a]::make_gen2::{opaque#0}), [Arc<RefCell<i32>>])`
+  --> $DIR/generator-print-verbose-1.rs:44:30
+   |
+LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: required because it appears within the type `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`
+  --> $DIR/generator-print-verbose-1.rs:50:34
+   |
+LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: required because it captures the following types: `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`
+note: required because it's used within this generator
+  --> $DIR/generator-print-verbose-1.rs:55:20
+   |
+LL |     let send_gen = || {
+   |                    ^^
+note: required by a bound in `require_send`
+  --> $DIR/generator-print-verbose-1.rs:29:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/print/generator-print-verbose-1.no_drop_tracking.stderr b/tests/ui/generator/print/generator-print-verbose-1.no_drop_tracking.stderr
new file mode 100644
index 00000000000..7d0a201699b
--- /dev/null
+++ b/tests/ui/generator/print/generator-print-verbose-1.no_drop_tracking.stderr
@@ -0,0 +1,64 @@
+error: generator cannot be sent between threads safely
+  --> $DIR/generator-print-verbose-1.rs:40:18
+   |
+LL |     require_send(send_gen);
+   |                  ^^^^^^^^ generator is not `Send`
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/generator-print-verbose-1.rs:38:9
+   |
+LL |         let _non_send_gen = make_non_send_generator();
+   |             ------------- has type `Opaque(DefId(0:34 ~ generator_print_verbose_1[749a]::make_non_send_generator::{opaque#0}), [])` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `_non_send_gen` maybe used later
+LL |     };
+   |     - `_non_send_gen` is later dropped here
+note: required by a bound in `require_send`
+  --> $DIR/generator-print-verbose-1.rs:29:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error[E0277]: `RefCell<i32>` cannot be shared between threads safely
+  --> $DIR/generator-print-verbose-1.rs:59:18
+   |
+LL |     require_send(send_gen);
+   |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+   = note: required for `Arc<RefCell<i32>>` to implement `Send`
+note: required because it's used within this generator
+  --> $DIR/generator-print-verbose-1.rs:45:5
+   |
+LL |     || {
+   |     ^^
+note: required because it appears within the type `Opaque(DefId(0:35 ~ generator_print_verbose_1[749a]::make_gen2::{opaque#0}), [Arc<RefCell<i32>>])`
+  --> $DIR/generator-print-verbose-1.rs:44:30
+   |
+LL | pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> {
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: required because it appears within the type `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`
+  --> $DIR/generator-print-verbose-1.rs:50:34
+   |
+LL | fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> {
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: required because it captures the following types: `Opaque(DefId(0:36 ~ generator_print_verbose_1[749a]::make_non_send_generator2::{opaque#0}), [])`, `()`
+note: required because it's used within this generator
+  --> $DIR/generator-print-verbose-1.rs:55:20
+   |
+LL |     let send_gen = || {
+   |                    ^^
+note: required by a bound in `require_send`
+  --> $DIR/generator-print-verbose-1.rs:29:25
+   |
+LL | fn require_send(_: impl Send) {}
+   |                         ^^^^ required by this bound in `require_send`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/print/generator-print-verbose-1.rs b/tests/ui/generator/print/generator-print-verbose-1.rs
index 89124ad7289..c7052c7d1b0 100644
--- a/tests/ui/generator/print/generator-print-verbose-1.rs
+++ b/tests/ui/generator/print/generator-print-verbose-1.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // compile-flags: -Zverbose
 
 // Same as: tests/ui/generator/issue-68112.stderr
@@ -12,7 +15,7 @@ use std::{
 };
 
 pub struct Ready<T>(Option<T>);
-impl<T> Generator<()> for Ready<T> {
+impl<T: Unpin> Generator<()> for Ready<T> {
     type Return = T;
     type Yield = ();
     fn resume(mut self: Pin<&mut Self>, _args: ()) -> GeneratorState<(), T> {
diff --git a/tests/ui/generator/print/generator-print-verbose-2.drop_tracking.stderr b/tests/ui/generator/print/generator-print-verbose-2.drop_tracking.stderr
new file mode 100644
index 00000000000..1f2e530f6f5
--- /dev/null
+++ b/tests/ui/generator/print/generator-print-verbose-2.drop_tracking.stderr
@@ -0,0 +1,60 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/generator-print-verbose-2.rs:20:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSync;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Sync`
+   |
+   = help: within `[main::{closure#0} upvar_tys=() {NotSync, ()}]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:23:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_sync`
+  --> $DIR/generator-print-verbose-2.rs:17:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/generator-print-verbose-2.rs:27:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSend;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[main::{closure#1} upvar_tys=() {NotSend, ()}]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:30:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/generator-print-verbose-2.rs:18:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/print/generator-print-verbose-2.drop_tracking_mir.stderr b/tests/ui/generator/print/generator-print-verbose-2.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..354369f1954
--- /dev/null
+++ b/tests/ui/generator/print/generator-print-verbose-2.drop_tracking_mir.stderr
@@ -0,0 +1,42 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/generator-print-verbose-2.rs:20:5
+   |
+LL |     assert_sync(|| {
+   |     ^^^^^^^^^^^ generator is not `Sync`
+   |
+   = help: within `[main::{closure#0} upvar_tys=() [main::{closure#0}]]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:23:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+note: required by a bound in `assert_sync`
+  --> $DIR/generator-print-verbose-2.rs:17:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/generator-print-verbose-2.rs:27:5
+   |
+LL |     assert_send(|| {
+   |     ^^^^^^^^^^^ generator is not `Send`
+   |
+   = help: within `[main::{closure#1} upvar_tys=() [main::{closure#1}]]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:30:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+note: required by a bound in `assert_send`
+  --> $DIR/generator-print-verbose-2.rs:18:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/print/generator-print-verbose-2.no_drop_tracking.stderr b/tests/ui/generator/print/generator-print-verbose-2.no_drop_tracking.stderr
new file mode 100644
index 00000000000..1f2e530f6f5
--- /dev/null
+++ b/tests/ui/generator/print/generator-print-verbose-2.no_drop_tracking.stderr
@@ -0,0 +1,60 @@
+error: generator cannot be shared between threads safely
+  --> $DIR/generator-print-verbose-2.rs:20:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSync;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Sync`
+   |
+   = help: within `[main::{closure#0} upvar_tys=() {NotSync, ()}]`, the trait `Sync` is not implemented for `NotSync`
+note: generator is not `Sync` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:23:9
+   |
+LL |         let a = NotSync;
+   |             - has type `NotSync` which is not `Sync`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_sync`
+  --> $DIR/generator-print-verbose-2.rs:17:23
+   |
+LL |     fn assert_sync<T: Sync>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_sync`
+
+error: generator cannot be sent between threads safely
+  --> $DIR/generator-print-verbose-2.rs:27:17
+   |
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         let a = NotSend;
+LL | |         yield;
+LL | |         drop(a);
+LL | |     });
+   | |_____^ generator is not `Send`
+   |
+   = help: within `[main::{closure#1} upvar_tys=() {NotSend, ()}]`, the trait `Send` is not implemented for `NotSend`
+note: generator is not `Send` as this value is used across a yield
+  --> $DIR/generator-print-verbose-2.rs:30:9
+   |
+LL |         let a = NotSend;
+   |             - has type `NotSend` which is not `Send`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `a` maybe used later
+LL |         drop(a);
+LL |     });
+   |     - `a` is later dropped here
+note: required by a bound in `assert_send`
+  --> $DIR/generator-print-verbose-2.rs:18:23
+   |
+LL |     fn assert_send<T: Send>(_: T) {}
+   |                       ^^^^ required by this bound in `assert_send`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/generator/print/generator-print-verbose-2.rs b/tests/ui/generator/print/generator-print-verbose-2.rs
index d914719cb36..ab29db6e09c 100644
--- a/tests/ui/generator/print/generator-print-verbose-2.rs
+++ b/tests/ui/generator/print/generator-print-verbose-2.rs
@@ -1,9 +1,17 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // compile-flags: -Zverbose
 
 // Same as test/ui/generator/not-send-sync.rs
 #![feature(generators)]
+#![feature(negative_impls)]
 
-use std::cell::Cell;
+struct NotSend;
+struct NotSync;
+
+impl !Send for NotSend {}
+impl !Sync for NotSync {}
 
 fn main() {
     fn assert_sync<T: Sync>(_: T) {}
@@ -11,14 +19,15 @@ fn main() {
 
     assert_sync(|| {
         //~^ ERROR: generator cannot be shared between threads safely
-        let a = Cell::new(2);
+        let a = NotSync;
         yield;
+        drop(a);
     });
 
-    let a = Cell::new(2);
     assert_send(|| {
-        //~^ ERROR: E0277
-        drop(&a);
+        //~^ ERROR: generator cannot be sent between threads safely
+        let a = NotSend;
         yield;
+        drop(a);
     });
 }
diff --git a/tests/ui/generator/print/generator-print-verbose-2.stderr b/tests/ui/generator/print/generator-print-verbose-2.stderr
deleted file mode 100644
index 909e49c38b8..00000000000
--- a/tests/ui/generator/print/generator-print-verbose-2.stderr
+++ /dev/null
@@ -1,56 +0,0 @@
-error[E0277]: `Cell<i32>` cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-2.rs:19:17
-   |
-LL |       assert_send(|| {
-   |  _____-----------_^
-   | |     |
-   | |     required by a bound introduced by this call
-LL | |
-LL | |         drop(&a);
-LL | |         yield;
-LL | |     });
-   | |_____^ `Cell<i32>` cannot be shared between threads safely
-   |
-   = help: the trait `Sync` is not implemented for `Cell<i32>`
-   = note: required for `&'_#4r Cell<i32>` to implement `Send`
-note: required because it's used within this generator
-  --> $DIR/generator-print-verbose-2.rs:19:17
-   |
-LL |     assert_send(|| {
-   |                 ^^
-note: required by a bound in `assert_send`
-  --> $DIR/generator-print-verbose-2.rs:10:23
-   |
-LL |     fn assert_send<T: Send>(_: T) {}
-   |                       ^^^^ required by this bound in `assert_send`
-
-error: generator cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-2.rs:12:17
-   |
-LL |       assert_sync(|| {
-   |  _________________^
-LL | |
-LL | |         let a = Cell::new(2);
-LL | |         yield;
-LL | |     });
-   | |_____^ generator is not `Sync`
-   |
-   = help: within `[main::{closure#0} upvar_tys=() {Cell<i32>, ()}]`, the trait `Sync` is not implemented for `Cell<i32>`
-note: generator is not `Sync` as this value is used across a yield
-  --> $DIR/generator-print-verbose-2.rs:15:9
-   |
-LL |         let a = Cell::new(2);
-   |             - has type `Cell<i32>` which is not `Sync`
-LL |         yield;
-   |         ^^^^^ yield occurs here, with `a` maybe used later
-LL |     });
-   |     - `a` is later dropped here
-note: required by a bound in `assert_sync`
-  --> $DIR/generator-print-verbose-2.rs:9:23
-   |
-LL |     fn assert_sync<T: Sync>(_: T) {}
-   |                       ^^^^ required by this bound in `assert_sync`
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/generator/retain-resume-ref.drop_tracking.stderr b/tests/ui/generator/retain-resume-ref.drop_tracking.stderr
new file mode 100644
index 00000000000..7122a951e80
--- /dev/null
+++ b/tests/ui/generator/retain-resume-ref.drop_tracking.stderr
@@ -0,0 +1,13 @@
+error[E0499]: cannot borrow `thing` as mutable more than once at a time
+  --> $DIR/retain-resume-ref.rs:27:25
+   |
+LL |     gen.as_mut().resume(&mut thing);
+   |                         ---------- first mutable borrow occurs here
+LL |     gen.as_mut().resume(&mut thing);
+   |                  ------ ^^^^^^^^^^ second mutable borrow occurs here
+   |                  |
+   |                  first borrow later used by call
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0499`.
diff --git a/tests/ui/generator/retain-resume-ref.drop_tracking_mir.stderr b/tests/ui/generator/retain-resume-ref.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..736ed1fb608
--- /dev/null
+++ b/tests/ui/generator/retain-resume-ref.drop_tracking_mir.stderr
@@ -0,0 +1,14 @@
+error[E0499]: cannot borrow `thing` as mutable more than once at a time
+  --> $DIR/retain-resume-ref.rs:27:25
+   |
+LL |     gen.as_mut().resume(&mut thing);
+   |                         ---------- first mutable borrow occurs here
+LL |     gen.as_mut().resume(&mut thing);
+   |                         ^^^^^^^^^^ second mutable borrow occurs here
+LL |
+LL | }
+   | - first borrow might be used here, when `gen` is dropped and runs the destructor for generator
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0499`.
diff --git a/tests/ui/generator/retain-resume-ref.no_drop_tracking.stderr b/tests/ui/generator/retain-resume-ref.no_drop_tracking.stderr
new file mode 100644
index 00000000000..7122a951e80
--- /dev/null
+++ b/tests/ui/generator/retain-resume-ref.no_drop_tracking.stderr
@@ -0,0 +1,13 @@
+error[E0499]: cannot borrow `thing` as mutable more than once at a time
+  --> $DIR/retain-resume-ref.rs:27:25
+   |
+LL |     gen.as_mut().resume(&mut thing);
+   |                         ---------- first mutable borrow occurs here
+LL |     gen.as_mut().resume(&mut thing);
+   |                  ------ ^^^^^^^^^^ second mutable borrow occurs here
+   |                  |
+   |                  first borrow later used by call
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0499`.
diff --git a/tests/ui/generator/retain-resume-ref.rs b/tests/ui/generator/retain-resume-ref.rs
index 0606ea71cdf..0050d98d03b 100644
--- a/tests/ui/generator/retain-resume-ref.rs
+++ b/tests/ui/generator/retain-resume-ref.rs
@@ -1,3 +1,7 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 //! This test ensures that a mutable reference cannot be passed as a resume argument twice.
 
 #![feature(generators, generator_trait)]
diff --git a/tests/ui/generator/retain-resume-ref.stderr b/tests/ui/generator/retain-resume-ref.stderr
index e33310d12d9..7122a951e80 100644
--- a/tests/ui/generator/retain-resume-ref.stderr
+++ b/tests/ui/generator/retain-resume-ref.stderr
@@ -1,5 +1,5 @@
 error[E0499]: cannot borrow `thing` as mutable more than once at a time
-  --> $DIR/retain-resume-ref.rs:23:25
+  --> $DIR/retain-resume-ref.rs:27:25
    |
 LL |     gen.as_mut().resume(&mut thing);
    |                         ---------- first mutable borrow occurs here
diff --git a/tests/ui/generator/static-mut-reference-across-yield.rs b/tests/ui/generator/static-mut-reference-across-yield.rs
index 0fa6d9cdc77..4784ff49be2 100644
--- a/tests/ui/generator/static-mut-reference-across-yield.rs
+++ b/tests/ui/generator/static-mut-reference-across-yield.rs
@@ -1,6 +1,8 @@
 // build-pass
-// revisions: mir thir
+// revisions: mir thir drop_tracking drop_tracking_mir
 // [thir]compile-flags: -Zthir-unsafeck
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 
 #![feature(generators)]
 
diff --git a/tests/ui/generic-associated-types/issue-74684-1.stderr b/tests/ui/generic-associated-types/issue-74684-1.stderr
index cacc973077c..b93ee37987f 100644
--- a/tests/ui/generic-associated-types/issue-74684-1.stderr
+++ b/tests/ui/generic-associated-types/issue-74684-1.stderr
@@ -4,6 +4,7 @@ error[E0597]: `a` does not live long enough
 LL | fn bug<'a, T: ?Sized + Fun<F<'a> = [u8]>>(_ : Box<T>) -> &'static T::F<'a> {
    |        -- lifetime `'a` defined here
 LL |     let a = [0; 1];
+   |         - binding `a` declared here
 LL |     let _x = T::identity(&a);
    |              ------------^^-
    |              |           |
diff --git a/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.rs b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.rs
new file mode 100644
index 00000000000..7ba2b6d857c
--- /dev/null
+++ b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.rs
@@ -0,0 +1,8 @@
+fn main() {
+    let x = 42;
+    match x {
+        0..=73 => {},
+        74..=> {},   //~ ERROR unexpected `=>` after open range
+                     //~^ ERROR expected one of `=>`, `if`, or `|`, found `>`
+    }
+}
diff --git a/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.stderr b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.stderr
new file mode 100644
index 00000000000..9ba6d15113c
--- /dev/null
+++ b/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-match-arrow.stderr
@@ -0,0 +1,19 @@
+error: unexpected `=>` after open range
+  --> $DIR/half-open-range-pats-inclusive-match-arrow.rs:5:11
+   |
+LL |         74..=> {},
+   |           ^^^
+   |
+help: add a space between the pattern and `=>`
+   |
+LL |         74.. => {},
+   |             +
+
+error: expected one of `=>`, `if`, or `|`, found `>`
+  --> $DIR/half-open-range-pats-inclusive-match-arrow.rs:5:14
+   |
+LL |         74..=> {},
+   |              ^ expected one of `=>`, `if`, or `|`
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.stderr b/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.stderr
index 4886a3c8bad..25af011e3fc 100644
--- a/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.stderr
+++ b/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/hrtb-identity-fn-borrows.rs:14:5
    |
 LL |     let y = f.call(&x);
-   |                    -- borrow of `x` occurs here
+   |                    -- `x` is borrowed here
 LL |     x = 5;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 ...
 LL |     drop(y);
    |          - borrow later used here
diff --git a/tests/ui/impl-trait/feature-self-return-type.stderr b/tests/ui/impl-trait/feature-self-return-type.stderr
index 601e53b7694..b9b8d00ce30 100644
--- a/tests/ui/impl-trait/feature-self-return-type.stderr
+++ b/tests/ui/impl-trait/feature-self-return-type.stderr
@@ -4,6 +4,7 @@ error[E0597]: `bar` does not live long enough
 LL |         let x = {
    |             - borrow later stored here
 LL |             let bar = 22;
+   |                 --- binding `bar` declared here
 LL |             Foo::new(&bar).into()
    |                      ^^^^ borrowed value does not live long enough
 LL |
@@ -16,6 +17,7 @@ error[E0597]: `y` does not live long enough
 LL |         let x = {
    |             - borrow later stored here
 LL |             let y = ();
+   |                 - binding `y` declared here
 LL |             foo(&y)
    |                 ^^ borrowed value does not live long enough
 LL |
@@ -28,6 +30,7 @@ error[E0597]: `y` does not live long enough
 LL |         let x = {
    |             - borrow later stored here
 LL |             let y = ();
+   |                 - binding `y` declared here
 LL |             foo(&y)
    |                 ^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/impl-trait/issue-55872-2.drop_tracking.stderr b/tests/ui/impl-trait/issue-55872-2.drop_tracking.stderr
new file mode 100644
index 00000000000..477c964bd40
--- /dev/null
+++ b/tests/ui/impl-trait/issue-55872-2.drop_tracking.stderr
@@ -0,0 +1,8 @@
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-2.rs:17:9
+   |
+LL |         async {}
+   |         ^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/impl-trait/issue-55872-2.drop_tracking_mir.stderr b/tests/ui/impl-trait/issue-55872-2.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..c14bb5cc914
--- /dev/null
+++ b/tests/ui/impl-trait/issue-55872-2.drop_tracking_mir.stderr
@@ -0,0 +1,14 @@
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-2.rs:17:9
+   |
+LL |         async {}
+   |         ^^^^^^^^
+
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-2.rs:17:9
+   |
+LL |         async {}
+   |         ^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/impl-trait/issue-55872-2.no_drop_tracking.stderr b/tests/ui/impl-trait/issue-55872-2.no_drop_tracking.stderr
new file mode 100644
index 00000000000..477c964bd40
--- /dev/null
+++ b/tests/ui/impl-trait/issue-55872-2.no_drop_tracking.stderr
@@ -0,0 +1,8 @@
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-2.rs:17:9
+   |
+LL |         async {}
+   |         ^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/impl-trait/issue-55872-2.rs b/tests/ui/impl-trait/issue-55872-2.rs
index 4443d3c4d0d..cbc7b5d62e1 100644
--- a/tests/ui/impl-trait/issue-55872-2.rs
+++ b/tests/ui/impl-trait/issue-55872-2.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 
 #![feature(type_alias_impl_trait)]
@@ -13,6 +16,7 @@ impl<S> Bar for S {
     fn foo<T>() -> Self::E {
         async {}
         //~^ ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+        //[drop_tracking_mir]~^^ ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
     }
 }
 
diff --git a/tests/ui/impl-trait/issue-55872-2.stderr b/tests/ui/impl-trait/issue-55872-2.stderr
index 11b8485c8bb..477c964bd40 100644
--- a/tests/ui/impl-trait/issue-55872-2.stderr
+++ b/tests/ui/impl-trait/issue-55872-2.stderr
@@ -1,5 +1,5 @@
 error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
-  --> $DIR/issue-55872-2.rs:14:9
+  --> $DIR/issue-55872-2.rs:17:9
    |
 LL |         async {}
    |         ^^^^^^^^
diff --git a/tests/ui/impl-trait/issues/infinite-impl-trait-issue-38064.stderr b/tests/ui/impl-trait/issues/infinite-impl-trait-issue-38064.stderr
index 16a1262ec27..92a3290622e 100644
--- a/tests/ui/impl-trait/issues/infinite-impl-trait-issue-38064.stderr
+++ b/tests/ui/impl-trait/issues/infinite-impl-trait-issue-38064.stderr
@@ -8,13 +8,13 @@ LL |     Foo(bar())
    |     ---------- returning here with type `Foo<impl Quux>`
 ...
 LL | fn bar() -> impl Quux {
-   |             --------- returning this opaque type `Foo<impl Quux>`
+   |             --------- returning this type `Foo<impl Quux>`
 
 error[E0720]: cannot resolve opaque type
   --> $DIR/infinite-impl-trait-issue-38064.rs:14:13
    |
 LL | fn foo() -> impl Quux {
-   |             --------- returning this opaque type `Bar<impl Quux>`
+   |             --------- returning this type `Bar<impl Quux>`
 ...
 LL | fn bar() -> impl Quux {
    |             ^^^^^^^^^ recursive opaque type
diff --git a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.stderr b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking.stderr
index ebb231ae14f..43118ae3854 100644
--- a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.stderr
+++ b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking.stderr
@@ -1,5 +1,5 @@
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:7:22
+  --> $DIR/recursive-impl-trait-type-indirect.rs:11:22
    |
 LL | fn option(i: i32) -> impl Sized {
    |                      ^^^^^^^^^^ recursive opaque type
@@ -10,7 +10,7 @@ LL |     if i < 0 { None } else { Some((option(i - 1), i)) }
    |                returning here with type `Option<(impl Sized, i32)>`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:12:15
+  --> $DIR/recursive-impl-trait-type-indirect.rs:16:15
    |
 LL | fn tuple() -> impl Sized {
    |               ^^^^^^^^^^ recursive opaque type
@@ -19,7 +19,7 @@ LL |     (tuple(),)
    |     ---------- returning here with type `(impl Sized,)`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:17:15
+  --> $DIR/recursive-impl-trait-type-indirect.rs:21:15
    |
 LL | fn array() -> impl Sized {
    |               ^^^^^^^^^^ recursive opaque type
@@ -28,7 +28,7 @@ LL |     [array()]
    |     --------- returning here with type `[impl Sized; 1]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:22:13
+  --> $DIR/recursive-impl-trait-type-indirect.rs:26:13
    |
 LL | fn ptr() -> impl Sized {
    |             ^^^^^^^^^^ recursive opaque type
@@ -37,7 +37,7 @@ LL |     &ptr() as *const _
    |     ------------------ returning here with type `*const impl Sized`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:27:16
+  --> $DIR/recursive-impl-trait-type-indirect.rs:31:16
    |
 LL | fn fn_ptr() -> impl Sized {
    |                ^^^^^^^^^^ recursive opaque type
@@ -46,7 +46,7 @@ LL |     fn_ptr as fn() -> _
    |     ------------------- returning here with type `fn() -> impl Sized`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:32:25
+  --> $DIR/recursive-impl-trait-type-indirect.rs:36:25
    |
 LL |   fn closure_capture() -> impl Sized {
    |                           ^^^^^^^^^^ recursive opaque type
@@ -55,10 +55,10 @@ LL | /     move || {
 LL | |         x;
    | |         - closure captures itself here
 LL | |     }
-   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:35:5: 35:12]`
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:39:5: 39:12]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:40:29
+  --> $DIR/recursive-impl-trait-type-indirect.rs:44:29
    |
 LL |   fn closure_ref_capture() -> impl Sized {
    |                               ^^^^^^^^^^ recursive opaque type
@@ -67,28 +67,28 @@ LL | /     move || {
 LL | |         &x;
    | |          - closure captures itself here
 LL | |     }
-   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:43:5: 43:12]`
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:47:5: 47:12]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:48:21
+  --> $DIR/recursive-impl-trait-type-indirect.rs:52:21
    |
 LL | fn closure_sig() -> impl Sized {
    |                     ^^^^^^^^^^ recursive opaque type
 LL |
 LL |     || closure_sig()
-   |     ---------------- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:50:5: 50:7]`
+   |     ---------------- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:54:5: 54:7]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:53:23
+  --> $DIR/recursive-impl-trait-type-indirect.rs:57:23
    |
 LL | fn generator_sig() -> impl Sized {
    |                       ^^^^^^^^^^ recursive opaque type
 LL |
 LL |     || generator_sig()
-   |     ------------------ returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:55:5: 55:7]`
+   |     ------------------ returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:59:5: 59:7]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:58:27
+  --> $DIR/recursive-impl-trait-type-indirect.rs:62:27
    |
 LL |   fn generator_capture() -> impl Sized {
    |                             ^^^^^^^^^^ recursive opaque type
@@ -98,10 +98,10 @@ LL | |         yield;
 LL | |         x;
    | |         - generator captures itself here
 LL | |     }
-   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:61:5: 61:12]`
+   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:65:5: 65:12]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:67:35
+  --> $DIR/recursive-impl-trait-type-indirect.rs:71:35
    |
 LL | fn substs_change<T: 'static>() -> impl Sized {
    |                                   ^^^^^^^^^^ recursive opaque type
@@ -110,7 +110,7 @@ LL |     (substs_change::<&T>(),)
    |     ------------------------ returning here with type `(impl Sized,)`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:72:24
+  --> $DIR/recursive-impl-trait-type-indirect.rs:76:24
    |
 LL |   fn generator_hold() -> impl Sized {
    |                          ^^^^^^^^^^ recursive opaque type
@@ -121,10 +121,10 @@ LL | |         let x = generator_hold();
 LL | |         yield;
 LL | |         x;
 LL | |     }
-   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:74:5: 74:12]`
+   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:78:5: 78:12]`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:86:26
+  --> $DIR/recursive-impl-trait-type-indirect.rs:90:26
    |
 LL | fn mutual_recursion() -> impl Sync {
    |                          ^^^^^^^^^ recursive opaque type
@@ -136,7 +136,7 @@ LL | fn mutual_recursion_b() -> impl Sized {
    |                            ---------- returning this opaque type `impl Sized`
 
 error[E0720]: cannot resolve opaque type
-  --> $DIR/recursive-impl-trait-type-indirect.rs:91:28
+  --> $DIR/recursive-impl-trait-type-indirect.rs:95:28
    |
 LL | fn mutual_recursion() -> impl Sync {
    |                          --------- returning this opaque type `impl Sync`
diff --git a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking_mir.stderr b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..662c74bcdc0
--- /dev/null
+++ b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking_mir.stderr
@@ -0,0 +1,144 @@
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:11:22
+   |
+LL | fn option(i: i32) -> impl Sized {
+   |                      ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     if i < 0 { None } else { Some((option(i - 1), i)) }
+   |                ----          ------------------------ returning here with type `Option<(impl Sized, i32)>`
+   |                |
+   |                returning here with type `Option<(impl Sized, i32)>`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:16:15
+   |
+LL | fn tuple() -> impl Sized {
+   |               ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     (tuple(),)
+   |     ---------- returning here with type `(impl Sized,)`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:21:15
+   |
+LL | fn array() -> impl Sized {
+   |               ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     [array()]
+   |     --------- returning here with type `[impl Sized; 1]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:26:13
+   |
+LL | fn ptr() -> impl Sized {
+   |             ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     &ptr() as *const _
+   |     ------------------ returning here with type `*const impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:31:16
+   |
+LL | fn fn_ptr() -> impl Sized {
+   |                ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     fn_ptr as fn() -> _
+   |     ------------------- returning here with type `fn() -> impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:36:25
+   |
+LL |   fn closure_capture() -> impl Sized {
+   |                           ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         x;
+   | |         - closure captures itself here
+LL | |     }
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:39:5: 39:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:44:29
+   |
+LL |   fn closure_ref_capture() -> impl Sized {
+   |                               ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         &x;
+   | |          - closure captures itself here
+LL | |     }
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:47:5: 47:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:52:21
+   |
+LL | fn closure_sig() -> impl Sized {
+   |                     ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     || closure_sig()
+   |     ---------------- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:54:5: 54:7]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:57:23
+   |
+LL | fn generator_sig() -> impl Sized {
+   |                       ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     || generator_sig()
+   |     ------------------ returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:59:5: 59:7]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:62:27
+   |
+LL |   fn generator_capture() -> impl Sized {
+   |                             ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         yield;
+LL | |         x;
+   | |         - generator captures itself here
+LL | |     }
+   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:65:5: 65:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:71:35
+   |
+LL | fn substs_change<T: 'static>() -> impl Sized {
+   |                                   ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     (substs_change::<&T>(),)
+   |     ------------------------ returning here with type `(impl Sized,)`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:76:24
+   |
+LL | fn generator_hold() -> impl Sized {
+   |                        ^^^^^^^^^^ recursive opaque type
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:90:26
+   |
+LL | fn mutual_recursion() -> impl Sync {
+   |                          ^^^^^^^^^ recursive opaque type
+LL |
+LL |     mutual_recursion_b()
+   |     -------------------- returning here with type `impl Sized`
+...
+LL | fn mutual_recursion_b() -> impl Sized {
+   |                            ---------- returning this opaque type `impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:95:28
+   |
+LL | fn mutual_recursion() -> impl Sync {
+   |                          --------- returning this opaque type `impl Sync`
+...
+LL | fn mutual_recursion_b() -> impl Sized {
+   |                            ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     mutual_recursion()
+   |     ------------------ returning here with type `impl Sync`
+
+error: aborting due to 14 previous errors
+
+For more information about this error, try `rustc --explain E0720`.
diff --git a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.no_drop_tracking.stderr b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.no_drop_tracking.stderr
new file mode 100644
index 00000000000..43118ae3854
--- /dev/null
+++ b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.no_drop_tracking.stderr
@@ -0,0 +1,152 @@
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:11:22
+   |
+LL | fn option(i: i32) -> impl Sized {
+   |                      ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     if i < 0 { None } else { Some((option(i - 1), i)) }
+   |                ----          ------------------------ returning here with type `Option<(impl Sized, i32)>`
+   |                |
+   |                returning here with type `Option<(impl Sized, i32)>`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:16:15
+   |
+LL | fn tuple() -> impl Sized {
+   |               ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     (tuple(),)
+   |     ---------- returning here with type `(impl Sized,)`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:21:15
+   |
+LL | fn array() -> impl Sized {
+   |               ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     [array()]
+   |     --------- returning here with type `[impl Sized; 1]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:26:13
+   |
+LL | fn ptr() -> impl Sized {
+   |             ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     &ptr() as *const _
+   |     ------------------ returning here with type `*const impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:31:16
+   |
+LL | fn fn_ptr() -> impl Sized {
+   |                ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     fn_ptr as fn() -> _
+   |     ------------------- returning here with type `fn() -> impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:36:25
+   |
+LL |   fn closure_capture() -> impl Sized {
+   |                           ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         x;
+   | |         - closure captures itself here
+LL | |     }
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:39:5: 39:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:44:29
+   |
+LL |   fn closure_ref_capture() -> impl Sized {
+   |                               ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         &x;
+   | |          - closure captures itself here
+LL | |     }
+   | |_____- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:47:5: 47:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:52:21
+   |
+LL | fn closure_sig() -> impl Sized {
+   |                     ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     || closure_sig()
+   |     ---------------- returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:54:5: 54:7]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:57:23
+   |
+LL | fn generator_sig() -> impl Sized {
+   |                       ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     || generator_sig()
+   |     ------------------ returning here with type `[closure@$DIR/recursive-impl-trait-type-indirect.rs:59:5: 59:7]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:62:27
+   |
+LL |   fn generator_capture() -> impl Sized {
+   |                             ^^^^^^^^^^ recursive opaque type
+...
+LL | /     move || {
+LL | |         yield;
+LL | |         x;
+   | |         - generator captures itself here
+LL | |     }
+   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:65:5: 65:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:71:35
+   |
+LL | fn substs_change<T: 'static>() -> impl Sized {
+   |                                   ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     (substs_change::<&T>(),)
+   |     ------------------------ returning here with type `(impl Sized,)`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:76:24
+   |
+LL |   fn generator_hold() -> impl Sized {
+   |                          ^^^^^^^^^^ recursive opaque type
+LL |
+LL | /     move || {
+LL | |         let x = generator_hold();
+   | |             - generator captures itself here
+LL | |         yield;
+LL | |         x;
+LL | |     }
+   | |_____- returning here with type `[generator@$DIR/recursive-impl-trait-type-indirect.rs:78:5: 78:12]`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:90:26
+   |
+LL | fn mutual_recursion() -> impl Sync {
+   |                          ^^^^^^^^^ recursive opaque type
+LL |
+LL |     mutual_recursion_b()
+   |     -------------------- returning here with type `impl Sized`
+...
+LL | fn mutual_recursion_b() -> impl Sized {
+   |                            ---------- returning this opaque type `impl Sized`
+
+error[E0720]: cannot resolve opaque type
+  --> $DIR/recursive-impl-trait-type-indirect.rs:95:28
+   |
+LL | fn mutual_recursion() -> impl Sync {
+   |                          --------- returning this opaque type `impl Sync`
+...
+LL | fn mutual_recursion_b() -> impl Sized {
+   |                            ^^^^^^^^^^ recursive opaque type
+LL |
+LL |     mutual_recursion()
+   |     ------------------ returning here with type `impl Sync`
+
+error: aborting due to 14 previous errors
+
+For more information about this error, try `rustc --explain E0720`.
diff --git a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.rs b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.rs
index ffc0cd9d10c..630372e13ed 100644
--- a/tests/ui/impl-trait/recursive-impl-trait-type-indirect.rs
+++ b/tests/ui/impl-trait/recursive-impl-trait-type-indirect.rs
@@ -1,3 +1,7 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 // Test that impl trait does not allow creating recursive types that are
 // otherwise forbidden.
 
diff --git a/tests/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.stderr b/tests/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.stderr
index d0249e74f39..307899297bc 100644
--- a/tests/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.stderr
+++ b/tests/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/assoc-ty-wf-used-to-get-assoc-ty.rs:24:31
    |
+LL |     let x: u8 = 3;
+   |         - binding `x` declared here
 LL |     let _: &'static u8 = test(&x, &&3);
    |                          -----^^------
    |                          |    |
diff --git a/tests/ui/imports/import-prefix-macro-1.stderr b/tests/ui/imports/import-prefix-macro-1.stderr
index 8868ee3aeaa..a6a5b1393da 100644
--- a/tests/ui/imports/import-prefix-macro-1.stderr
+++ b/tests/ui/imports/import-prefix-macro-1.stderr
@@ -2,7 +2,7 @@ error: expected one of `::`, `;`, or `as`, found `{`
   --> $DIR/import-prefix-macro-1.rs:11:27
    |
 LL |     ($p: path) => (use $p {S, Z});
-   |                           ^^^^^^ expected one of `::`, `;`, or `as`
+   |                           ^ expected one of `::`, `;`, or `as`
 ...
 LL | import! { a::b::c }
    | ------------------- in this macro invocation
diff --git a/tests/ui/inline-const/const-expr-lifetime-err.stderr b/tests/ui/inline-const/const-expr-lifetime-err.stderr
index a23f7c9a796..443fcf89c4e 100644
--- a/tests/ui/inline-const/const-expr-lifetime-err.stderr
+++ b/tests/ui/inline-const/const-expr-lifetime-err.stderr
@@ -4,6 +4,7 @@ error[E0597]: `y` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let y = ();
+   |         - binding `y` declared here
 LL |     equate(InvariantRef::new(&y), const { InvariantRef::<'a>::NEW });
    |            ------------------^^-
    |            |                 |
diff --git a/tests/ui/io-checks/inaccessbile-temp-dir.rs b/tests/ui/io-checks/inaccessbile-temp-dir.rs
new file mode 100644
index 00000000000..9c0aa013572
--- /dev/null
+++ b/tests/ui/io-checks/inaccessbile-temp-dir.rs
@@ -0,0 +1,39 @@
+// Issue #66530: We would ICE if someone compiled with `-o /dev/null`,
+// because we would try to generate auxiliary files in `/dev/` (which
+// at least the OS X file system rejects).
+//
+// An attempt to `-o` into a directory we cannot write into should indeed
+// be an error; but not an ICE.
+//
+// However, some folks run tests as root, which can write `/dev/` and end
+// up clobbering `/dev/null`. Instead we'll use a non-existent path, which
+// also used to ICE, but even root can't magically write there.
+
+// compile-flags: -Z temps-dir=/does-not-exist/output
+
+// The error-pattern check occurs *before* normalization, and the error patterns
+// are wildly different between build environments. So this is a cop-out (and we
+// rely on the checking of the normalized stderr output as our actual
+// "verification" of the diagnostic).
+
+// error-pattern: error
+
+// On Mac OS X, we get an error like the below
+// normalize-stderr-test "failed to write bytecode to /does-not-exist/output.non_ice_error_on_worker_io_fail.*" -> "io error modifying /does-not-exist/"
+
+// On Linux, we get an error like the below
+// normalize-stderr-test "couldn't create a temp dir.*" -> "io error modifying /does-not-exist/"
+
+// ignore-windows - this is a unix-specific test
+// ignore-emscripten - the file-system issues do not replicate here
+// ignore-wasm - the file-system issues do not replicate here
+// ignore-arm - the file-system issues do not replicate here, at least on armhf-gnu
+
+#![crate_type = "lib"]
+#![cfg_attr(not(feature = "std"), no_std)]
+pub mod task {
+    pub mod __internal {
+        use crate::task::Waker;
+    }
+    pub use core::task::Waker;
+}
diff --git a/tests/ui/io-checks/inaccessbile-temp-dir.stderr b/tests/ui/io-checks/inaccessbile-temp-dir.stderr
new file mode 100644
index 00000000000..2fc5f93ef79
--- /dev/null
+++ b/tests/ui/io-checks/inaccessbile-temp-dir.stderr
@@ -0,0 +1,4 @@
+error: failed to find or create the directory specified by `--temps-dir`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/non-ice-error-on-worker-io-fail.rs b/tests/ui/io-checks/non-ice-error-on-worker-io-fail.rs
index 134e7d420e3..134e7d420e3 100644
--- a/tests/ui/non-ice-error-on-worker-io-fail.rs
+++ b/tests/ui/io-checks/non-ice-error-on-worker-io-fail.rs
diff --git a/tests/ui/non-ice-error-on-worker-io-fail.stderr b/tests/ui/io-checks/non-ice-error-on-worker-io-fail.stderr
index edadecf273a..edadecf273a 100644
--- a/tests/ui/non-ice-error-on-worker-io-fail.stderr
+++ b/tests/ui/io-checks/non-ice-error-on-worker-io-fail.stderr
diff --git a/tests/ui/issues/issue-40288.stderr b/tests/ui/issues/issue-40288.stderr
index fb4ecab362d..db5d064379a 100644
--- a/tests/ui/issues/issue-40288.stderr
+++ b/tests/ui/issues/issue-40288.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `*refr` because it is borrowed
   --> $DIR/issue-40288.rs:16:5
    |
 LL |     save_ref(&*refr, &mut out);
-   |              ------ borrow of `*refr` occurs here
+   |              ------ `*refr` is borrowed here
 ...
 LL |     *refr = 3;
-   |     ^^^^^^^^^ assignment to borrowed `*refr` occurs here
+   |     ^^^^^^^^^ `*refr` is assigned to here but it was already borrowed
 ...
 LL |     println!("{:?}", out[0]);
    |                      ------ borrow later used here
diff --git a/tests/ui/issues/issue-45697-1.stderr b/tests/ui/issues/issue-45697-1.stderr
index 30c69f19658..474313398e2 100644
--- a/tests/ui/issues/issue-45697-1.stderr
+++ b/tests/ui/issues/issue-45697-1.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `*y.pointer` because it was mutably borrowed
   --> $DIR/issue-45697-1.rs:20:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `y` occurs here
+   |                                   ------ `y` is borrowed here
 LL |         *y.pointer += 1;
    |         ^^^^^^^^^^^^^^^ use of borrowed `y`
 ...
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `*y.pointer` because it is borrowed
   --> $DIR/issue-45697-1.rs:20:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `*y.pointer` occurs here
+   |                                   ------ `*y.pointer` is borrowed here
 LL |         *y.pointer += 1;
-   |         ^^^^^^^^^^^^^^^ assignment to borrowed `*y.pointer` occurs here
+   |         ^^^^^^^^^^^^^^^ `*y.pointer` is assigned to here but it was already borrowed
 ...
 LL |         *z.pointer += 1;
    |         --------------- borrow later used here
diff --git a/tests/ui/issues/issue-45697.stderr b/tests/ui/issues/issue-45697.stderr
index 26749d36f0b..7986fd5c9df 100644
--- a/tests/ui/issues/issue-45697.stderr
+++ b/tests/ui/issues/issue-45697.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `*y.pointer` because it was mutably borrowed
   --> $DIR/issue-45697.rs:20:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `y` occurs here
+   |                                   ------ `y` is borrowed here
 LL |         *y.pointer += 1;
    |         ^^^^^^^^^^^^^^^ use of borrowed `y`
 ...
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `*y.pointer` because it is borrowed
   --> $DIR/issue-45697.rs:20:9
    |
 LL |         let z = copy_borrowed_ptr(&mut y);
-   |                                   ------ borrow of `*y.pointer` occurs here
+   |                                   ------ `*y.pointer` is borrowed here
 LL |         *y.pointer += 1;
-   |         ^^^^^^^^^^^^^^^ assignment to borrowed `*y.pointer` occurs here
+   |         ^^^^^^^^^^^^^^^ `*y.pointer` is assigned to here but it was already borrowed
 ...
 LL |         *z.pointer += 1;
    |         --------------- borrow later used here
diff --git a/tests/ui/issues/issue-46471-1.stderr b/tests/ui/issues/issue-46471-1.stderr
index b09f31729a5..2ae6e709d5a 100644
--- a/tests/ui/issues/issue-46471-1.stderr
+++ b/tests/ui/issues/issue-46471-1.stderr
@@ -1,11 +1,10 @@
 error[E0597]: `z` does not live long enough
   --> $DIR/issue-46471-1.rs:4:9
    |
+LL |         let mut z = 0;
+   |             ----- binding `z` declared here
 LL |         &mut z
-   |         ^^^^^^
-   |         |
-   |         borrowed value does not live long enough
-   |         borrow later used here
+   |         ^^^^^^ borrowed value does not live long enough
 LL |     };
    |     - `z` dropped here while still borrowed
 
diff --git a/tests/ui/issues/issue-52126-assign-op-invariance.stderr b/tests/ui/issues/issue-52126-assign-op-invariance.stderr
index d4506757762..2d3b48832c5 100644
--- a/tests/ui/issues/issue-52126-assign-op-invariance.stderr
+++ b/tests/ui/issues/issue-52126-assign-op-invariance.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `line` does not live long enough
   --> $DIR/issue-52126-assign-op-invariance.rs:34:28
    |
+LL |     for line in vec!["123456789".to_string(), "12345678".to_string()] {
+   |         ---- binding `line` declared here
 LL |         let v: Vec<&str> = line.split_whitespace().collect();
    |                            ^^^^^^^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/issues/issue-7364.stderr b/tests/ui/issues/issue-7364.stderr
index 5dc8c2b607e..aee73380f15 100644
--- a/tests/ui/issues/issue-7364.stderr
+++ b/tests/ui/issues/issue-7364.stderr
@@ -5,6 +5,7 @@ LL | static boxed: Box<RefCell<isize>> = Box::new(RefCell::new(0));
    |               ^^^^^^^^^^^^^^^^^^^ `RefCell<isize>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `RefCell<isize>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Unique<RefCell<isize>>` to implement `Sync`
    = note: required because it appears within the type `Box<RefCell<isize>>`
    = note: shared static variables must have a type that implements `Sync`
diff --git a/tests/ui/let-else/accidental-if.rs b/tests/ui/let-else/accidental-if.rs
new file mode 100644
index 00000000000..3fba630435c
--- /dev/null
+++ b/tests/ui/let-else/accidental-if.rs
@@ -0,0 +1,6 @@
+fn main() {
+    let x = Some(123);
+    if let Some(y) = x else { //~ ERROR this `if` expression is missing a block
+        return;
+    };
+}
diff --git a/tests/ui/let-else/accidental-if.stderr b/tests/ui/let-else/accidental-if.stderr
new file mode 100644
index 00000000000..5474a67aac4
--- /dev/null
+++ b/tests/ui/let-else/accidental-if.stderr
@@ -0,0 +1,19 @@
+error: this `if` expression is missing a block after the condition
+  --> $DIR/accidental-if.rs:3:5
+   |
+LL |     if let Some(y) = x else {
+   |     ^^
+   |
+help: add a block here
+  --> $DIR/accidental-if.rs:3:23
+   |
+LL |     if let Some(y) = x else {
+   |                       ^
+help: remove the `if` if you meant to write a `let...else` statement
+  --> $DIR/accidental-if.rs:3:5
+   |
+LL |     if let Some(y) = x else {
+   |     ^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.fixed b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.fixed
new file mode 100644
index 00000000000..aa3bce2945b
--- /dev/null
+++ b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.fixed
@@ -0,0 +1,45 @@
+// run-rustfix
+
+trait Greeter0 {
+    fn greet(&self);
+}
+
+trait Greeter1 {
+    fn greet(&self);
+}
+
+type BoxedGreeter<'a> = (Box<dyn Greeter0 + 'a>, Box<dyn Greeter1 + 'a>);
+//~^ HELP to declare that the trait object captures data from argument `self`, you can add a lifetime parameter `'a` in the type alias
+
+struct FixedGreeter<'a>(pub &'a str);
+
+impl Greeter0 for FixedGreeter<'_> {
+    fn greet(&self) {
+        println!("0 {}", self.0)
+    }
+}
+
+impl Greeter1 for FixedGreeter<'_> {
+    fn greet(&self) {
+        println!("1 {}", self.0)
+    }
+}
+
+struct Greetings(pub Vec<String>);
+
+impl Greetings {
+    pub fn get(&self, i: usize) -> BoxedGreeter {
+        (Box::new(FixedGreeter(&self.0[i])), Box::new(FixedGreeter(&self.0[i])))
+        //~^ ERROR lifetime may not live long enough
+    }
+}
+
+fn main() {
+    let mut g = Greetings {0 : vec!()};
+    g.0.push("a".to_string());
+    g.0.push("b".to_string());
+    g.get(0).0.greet();
+    g.get(0).1.greet();
+    g.get(1).0.greet();
+    g.get(1).1.greet();
+}
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs
new file mode 100644
index 00000000000..20c88ec6981
--- /dev/null
+++ b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs
@@ -0,0 +1,45 @@
+// run-rustfix
+
+trait Greeter0 {
+    fn greet(&self);
+}
+
+trait Greeter1 {
+    fn greet(&self);
+}
+
+type BoxedGreeter = (Box<dyn Greeter0>, Box<dyn Greeter1>);
+//~^ HELP to declare that the trait object captures data from argument `self`, you can add a lifetime parameter `'a` in the type alias
+
+struct FixedGreeter<'a>(pub &'a str);
+
+impl Greeter0 for FixedGreeter<'_> {
+    fn greet(&self) {
+        println!("0 {}", self.0)
+    }
+}
+
+impl Greeter1 for FixedGreeter<'_> {
+    fn greet(&self) {
+        println!("1 {}", self.0)
+    }
+}
+
+struct Greetings(pub Vec<String>);
+
+impl Greetings {
+    pub fn get(&self, i: usize) -> BoxedGreeter {
+        (Box::new(FixedGreeter(&self.0[i])), Box::new(FixedGreeter(&self.0[i])))
+        //~^ ERROR lifetime may not live long enough
+    }
+}
+
+fn main() {
+    let mut g = Greetings {0 : vec!()};
+    g.0.push("a".to_string());
+    g.0.push("b".to_string());
+    g.get(0).0.greet();
+    g.get(0).1.greet();
+    g.get(1).0.greet();
+    g.get(1).1.greet();
+}
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.stderr b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.stderr
new file mode 100644
index 00000000000..808d8bb9058
--- /dev/null
+++ b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.stderr
@@ -0,0 +1,15 @@
+error: lifetime may not live long enough
+  --> $DIR/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs:32:9
+   |
+LL |     pub fn get(&self, i: usize) -> BoxedGreeter {
+   |                - let's call the lifetime of this reference `'1`
+LL |         (Box::new(FixedGreeter(&self.0[i])), Box::new(FixedGreeter(&self.0[i])))
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ returning this value requires that `'1` must outlive `'static`
+   |
+help: to declare that the trait object captures data from argument `self`, you can add a lifetime parameter `'a` in the type alias
+   |
+LL | type BoxedGreeter<'a> = (Box<dyn Greeter0 + 'a>, Box<dyn Greeter1 + 'a>);
+   |                  ++++                     ++++                    ++++
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lifetimes/issue-90600-expected-return-static-indirect.stderr b/tests/ui/lifetimes/issue-90600-expected-return-static-indirect.stderr
index 99e1e7217b4..3602de8dd95 100644
--- a/tests/ui/lifetimes/issue-90600-expected-return-static-indirect.stderr
+++ b/tests/ui/lifetimes/issue-90600-expected-return-static-indirect.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `foo` does not live long enough
   --> $DIR/issue-90600-expected-return-static-indirect.rs:7:32
    |
+LL | fn inner(mut foo: &[u8]) {
+   |          ------- binding `foo` declared here
 LL |     let refcell = RefCell::new(&mut foo);
    |                                ^^^^^^^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/lint/must_not_suspend/dedup.drop_tracking.stderr b/tests/ui/lint/must_not_suspend/dedup.drop_tracking.stderr
new file mode 100644
index 00000000000..262657da5fe
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/dedup.drop_tracking.stderr
@@ -0,0 +1,21 @@
+error: `No` held across a suspend point, but should not be
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+LL |     wheeee(&no).await;
+   |                ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+note: the lint level is defined here
+  --> $DIR/dedup.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/dedup.drop_tracking_mir.stderr b/tests/ui/lint/must_not_suspend/dedup.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..262657da5fe
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/dedup.drop_tracking_mir.stderr
@@ -0,0 +1,21 @@
+error: `No` held across a suspend point, but should not be
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+LL |     wheeee(&no).await;
+   |                ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+note: the lint level is defined here
+  --> $DIR/dedup.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/dedup.no_drop_tracking.stderr b/tests/ui/lint/must_not_suspend/dedup.no_drop_tracking.stderr
new file mode 100644
index 00000000000..7ed43d25719
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/dedup.no_drop_tracking.stderr
@@ -0,0 +1,33 @@
+error: `No` held across a suspend point, but should not be
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+LL |     wheeee(&no).await;
+   |                ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/dedup.rs:19:9
+   |
+LL |     let no = No {};
+   |         ^^
+note: the lint level is defined here
+  --> $DIR/dedup.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: `No` held across a suspend point, but should not be
+  --> $DIR/dedup.rs:20:13
+   |
+LL |     wheeee(&no).await;
+   |             ^^ ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/dedup.rs:20:13
+   |
+LL |     wheeee(&no).await;
+   |             ^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/lint/must_not_suspend/dedup.rs b/tests/ui/lint/must_not_suspend/dedup.rs
index 81a08579bb7..96bdb7715b1 100644
--- a/tests/ui/lint/must_not_suspend/dedup.rs
+++ b/tests/ui/lint/must_not_suspend/dedup.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
@@ -13,7 +16,9 @@ async fn wheeee<T>(t: T) {
 }
 
 async fn yes() {
-    wheeee(&No {}).await; //~ ERROR `No` held across
+    let no = No {}; //~ ERROR `No` held across
+    wheeee(&no).await; //[no_drop_tracking]~ ERROR `No` held across
+    drop(no);
 }
 
 fn main() {
diff --git a/tests/ui/lint/must_not_suspend/dedup.stderr b/tests/ui/lint/must_not_suspend/dedup.stderr
index f8978ba57f1..18880f5a757 100644
--- a/tests/ui/lint/must_not_suspend/dedup.stderr
+++ b/tests/ui/lint/must_not_suspend/dedup.stderr
@@ -1,16 +1,16 @@
 error: `No` held across a suspend point, but should not be
-  --> $DIR/dedup.rs:16:13
+  --> $DIR/dedup.rs:19:13
    |
 LL |     wheeee(&No {}).await;
    |             ^^^^^ ------ the value is held across this suspend point
    |
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/dedup.rs:16:13
+  --> $DIR/dedup.rs:19:13
    |
 LL |     wheeee(&No {}).await;
    |             ^^^^^
 note: the lint level is defined here
-  --> $DIR/dedup.rs:3:9
+  --> $DIR/dedup.rs:6:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/must_not_suspend/ref.drop_tracking.stderr b/tests/ui/lint/must_not_suspend/ref.drop_tracking.stderr
index abf76711bf0..e3628ca5e49 100644
--- a/tests/ui/lint/must_not_suspend/ref.drop_tracking.stderr
+++ b/tests/ui/lint/must_not_suspend/ref.drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: reference to `Umm` held across a suspend point, but should not be
-  --> $DIR/ref.rs:21:13
+  --> $DIR/ref.rs:22:13
    |
 LL |         let guard = &mut self.u;
    |             ^^^^^
@@ -8,17 +8,17 @@ LL |         other().await;
    |                ------ the value is held across this suspend point
    |
 note: You gotta use Umm's, ya know?
-  --> $DIR/ref.rs:21:13
+  --> $DIR/ref.rs:22:13
    |
 LL |         let guard = &mut self.u;
    |             ^^^^^
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/ref.rs:21:13
+  --> $DIR/ref.rs:22:13
    |
 LL |         let guard = &mut self.u;
    |             ^^^^^
 note: the lint level is defined here
-  --> $DIR/ref.rs:6:9
+  --> $DIR/ref.rs:7:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/must_not_suspend/ref.drop_tracking_mir.stderr b/tests/ui/lint/must_not_suspend/ref.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..e3628ca5e49
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/ref.drop_tracking_mir.stderr
@@ -0,0 +1,27 @@
+error: reference to `Umm` held across a suspend point, but should not be
+  --> $DIR/ref.rs:22:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+LL |
+LL |         other().await;
+   |                ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/ref.rs:22:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/ref.rs:22:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+note: the lint level is defined here
+  --> $DIR/ref.rs:7:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr b/tests/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr
index 41ac09ea72a..e9bfa08b5dd 100644
--- a/tests/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr
+++ b/tests/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: `Umm` held across a suspend point, but should not be
-  --> $DIR/ref.rs:21:26
+  --> $DIR/ref.rs:22:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
@@ -8,17 +8,17 @@ LL |         other().await;
    |                ------ the value is held across this suspend point
    |
 note: You gotta use Umm's, ya know?
-  --> $DIR/ref.rs:21:26
+  --> $DIR/ref.rs:22:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/ref.rs:21:26
+  --> $DIR/ref.rs:22:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
 note: the lint level is defined here
-  --> $DIR/ref.rs:6:9
+  --> $DIR/ref.rs:7:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/must_not_suspend/ref.rs b/tests/ui/lint/must_not_suspend/ref.rs
index f6b23746fef..d05dcb83ac5 100644
--- a/tests/ui/lint/must_not_suspend/ref.rs
+++ b/tests/ui/lint/must_not_suspend/ref.rs
@@ -1,7 +1,8 @@
 // edition:2018
-// revisions: no_drop_tracking drop_tracking
-// [drop_tracking] compile-flags: -Zdrop-tracking=yes
-// [no_drop_tracking] compile-flags: -Zdrop-tracking=no
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
+
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
 
@@ -22,6 +23,7 @@ impl Bar {
 
         other().await;
 
+        let _g = &*guard;
         *guard = Umm { i: 2 }
     }
 }
diff --git a/tests/ui/lint/must_not_suspend/trait.drop_tracking.stderr b/tests/ui/lint/must_not_suspend/trait.drop_tracking.stderr
new file mode 100644
index 00000000000..6e62a228a43
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/trait.drop_tracking.stderr
@@ -0,0 +1,37 @@
+error: implementer of `Wow` held across a suspend point, but should not be
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+...
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+note: the lint level is defined here
+  --> $DIR/trait.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: boxed `Wow` trait object held across a suspend point, but should not be
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+LL |
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/lint/must_not_suspend/trait.drop_tracking_mir.stderr b/tests/ui/lint/must_not_suspend/trait.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..6e62a228a43
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/trait.drop_tracking_mir.stderr
@@ -0,0 +1,37 @@
+error: implementer of `Wow` held across a suspend point, but should not be
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+...
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+note: the lint level is defined here
+  --> $DIR/trait.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: boxed `Wow` trait object held across a suspend point, but should not be
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+LL |
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/lint/must_not_suspend/trait.no_drop_tracking.stderr b/tests/ui/lint/must_not_suspend/trait.no_drop_tracking.stderr
new file mode 100644
index 00000000000..6e62a228a43
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/trait.no_drop_tracking.stderr
@@ -0,0 +1,37 @@
+error: implementer of `Wow` held across a suspend point, but should not be
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+...
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:24:9
+   |
+LL |     let _guard1 = r#impl();
+   |         ^^^^^^^
+note: the lint level is defined here
+  --> $DIR/trait.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: boxed `Wow` trait object held across a suspend point, but should not be
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+LL |
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/trait.rs:25:9
+   |
+LL |     let _guard2 = r#dyn();
+   |         ^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/lint/must_not_suspend/trait.rs b/tests/ui/lint/must_not_suspend/trait.rs
index 6c911cb4b0f..cc3ae298dbb 100644
--- a/tests/ui/lint/must_not_suspend/trait.rs
+++ b/tests/ui/lint/must_not_suspend/trait.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
@@ -22,6 +25,9 @@ pub async fn uhoh() {
     let _guard2 = r#dyn(); //~ ERROR boxed `Wow` trait object held across
 
     other().await;
+
+    drop(_guard1);
+    drop(_guard2);
 }
 
 fn main() {
diff --git a/tests/ui/lint/must_not_suspend/trait.stderr b/tests/ui/lint/must_not_suspend/trait.stderr
index d64d25aae52..6e62a228a43 100644
--- a/tests/ui/lint/must_not_suspend/trait.stderr
+++ b/tests/ui/lint/must_not_suspend/trait.stderr
@@ -1,5 +1,5 @@
 error: implementer of `Wow` held across a suspend point, but should not be
-  --> $DIR/trait.rs:21:9
+  --> $DIR/trait.rs:24:9
    |
 LL |     let _guard1 = r#impl();
    |         ^^^^^^^
@@ -8,18 +8,18 @@ LL |     other().await;
    |            ------ the value is held across this suspend point
    |
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/trait.rs:21:9
+  --> $DIR/trait.rs:24:9
    |
 LL |     let _guard1 = r#impl();
    |         ^^^^^^^
 note: the lint level is defined here
-  --> $DIR/trait.rs:3:9
+  --> $DIR/trait.rs:6:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
 
 error: boxed `Wow` trait object held across a suspend point, but should not be
-  --> $DIR/trait.rs:22:9
+  --> $DIR/trait.rs:25:9
    |
 LL |     let _guard2 = r#dyn();
    |         ^^^^^^^
@@ -28,7 +28,7 @@ LL |     other().await;
    |            ------ the value is held across this suspend point
    |
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/trait.rs:22:9
+  --> $DIR/trait.rs:25:9
    |
 LL |     let _guard2 = r#dyn();
    |         ^^^^^^^
diff --git a/tests/ui/lint/must_not_suspend/unit.drop_tracking.stderr b/tests/ui/lint/must_not_suspend/unit.drop_tracking.stderr
new file mode 100644
index 00000000000..f89b3e341fd
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/unit.drop_tracking.stderr
@@ -0,0 +1,26 @@
+error: `Umm` held across a suspend point, but should not be
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/unit.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/unit.drop_tracking_mir.stderr b/tests/ui/lint/must_not_suspend/unit.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..f89b3e341fd
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/unit.drop_tracking_mir.stderr
@@ -0,0 +1,26 @@
+error: `Umm` held across a suspend point, but should not be
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/unit.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/unit.no_drop_tracking.stderr b/tests/ui/lint/must_not_suspend/unit.no_drop_tracking.stderr
new file mode 100644
index 00000000000..f89b3e341fd
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/unit.no_drop_tracking.stderr
@@ -0,0 +1,26 @@
+error: `Umm` held across a suspend point, but should not be
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/unit.rs:22:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/unit.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/lint/must_not_suspend/unit.rs b/tests/ui/lint/must_not_suspend/unit.rs
index d3a19f70432..fbc51b36681 100644
--- a/tests/ui/lint/must_not_suspend/unit.rs
+++ b/tests/ui/lint/must_not_suspend/unit.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
@@ -7,7 +10,6 @@ struct Umm {
     i: i64
 }
 
-
 fn bar() -> Umm {
     Umm {
         i: 1
@@ -19,6 +21,7 @@ async fn other() {}
 pub async fn uhoh() {
     let _guard = bar(); //~ ERROR `Umm` held across
     other().await;
+    drop(_guard);
 }
 
 fn main() {
diff --git a/tests/ui/lint/must_not_suspend/unit.stderr b/tests/ui/lint/must_not_suspend/unit.stderr
index c967dbac56c..50ca292c2f6 100644
--- a/tests/ui/lint/must_not_suspend/unit.stderr
+++ b/tests/ui/lint/must_not_suspend/unit.stderr
@@ -1,5 +1,5 @@
 error: `Umm` held across a suspend point, but should not be
-  --> $DIR/unit.rs:20:9
+  --> $DIR/unit.rs:23:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
@@ -7,17 +7,17 @@ LL |     other().await;
    |            ------ the value is held across this suspend point
    |
 note: You gotta use Umm's, ya know?
-  --> $DIR/unit.rs:20:9
+  --> $DIR/unit.rs:23:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/unit.rs:20:9
+  --> $DIR/unit.rs:23:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
 note: the lint level is defined here
-  --> $DIR/unit.rs:3:9
+  --> $DIR/unit.rs:6:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/must_not_suspend/warn.drop_tracking.stderr b/tests/ui/lint/must_not_suspend/warn.drop_tracking.stderr
new file mode 100644
index 00000000000..7a422891ab1
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/warn.drop_tracking.stderr
@@ -0,0 +1,26 @@
+warning: `Umm` held across a suspend point, but should not be
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/warn.rs:7:9
+   |
+LL | #![warn(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/lint/must_not_suspend/warn.drop_tracking_mir.stderr b/tests/ui/lint/must_not_suspend/warn.drop_tracking_mir.stderr
new file mode 100644
index 00000000000..7a422891ab1
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/warn.drop_tracking_mir.stderr
@@ -0,0 +1,26 @@
+warning: `Umm` held across a suspend point, but should not be
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/warn.rs:7:9
+   |
+LL | #![warn(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/lint/must_not_suspend/warn.no_drop_tracking.stderr b/tests/ui/lint/must_not_suspend/warn.no_drop_tracking.stderr
new file mode 100644
index 00000000000..7a422891ab1
--- /dev/null
+++ b/tests/ui/lint/must_not_suspend/warn.no_drop_tracking.stderr
@@ -0,0 +1,26 @@
+warning: `Umm` held across a suspend point, but should not be
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+LL |     other().await;
+   |            ------ the value is held across this suspend point
+   |
+note: You gotta use Umm's, ya know?
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/warn.rs:24:9
+   |
+LL |     let _guard = bar();
+   |         ^^^^^^
+note: the lint level is defined here
+  --> $DIR/warn.rs:7:9
+   |
+LL | #![warn(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/lint/must_not_suspend/warn.rs b/tests/ui/lint/must_not_suspend/warn.rs
index 7fdea66a235..5a4863169ea 100644
--- a/tests/ui/lint/must_not_suspend/warn.rs
+++ b/tests/ui/lint/must_not_suspend/warn.rs
@@ -1,3 +1,6 @@
+// revisions: no_drop_tracking drop_tracking drop_tracking_mir
+// [drop_tracking] compile-flags: -Zdrop-tracking
+// [drop_tracking_mir] compile-flags: -Zdrop-tracking-mir
 // edition:2018
 // run-pass
 #![feature(must_not_suspend)]
@@ -20,6 +23,7 @@ async fn other() {}
 pub async fn uhoh() {
     let _guard = bar(); //~ WARNING `Umm` held across
     other().await;
+    drop(_guard);
 }
 
 fn main() {
diff --git a/tests/ui/lint/must_not_suspend/warn.stderr b/tests/ui/lint/must_not_suspend/warn.stderr
index fe551c6521d..7a422891ab1 100644
--- a/tests/ui/lint/must_not_suspend/warn.stderr
+++ b/tests/ui/lint/must_not_suspend/warn.stderr
@@ -1,5 +1,5 @@
 warning: `Umm` held across a suspend point, but should not be
-  --> $DIR/warn.rs:21:9
+  --> $DIR/warn.rs:24:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
@@ -7,17 +7,17 @@ LL |     other().await;
    |            ------ the value is held across this suspend point
    |
 note: You gotta use Umm's, ya know?
-  --> $DIR/warn.rs:21:9
+  --> $DIR/warn.rs:24:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/warn.rs:21:9
+  --> $DIR/warn.rs:24:9
    |
 LL |     let _guard = bar();
    |         ^^^^^^
 note: the lint level is defined here
-  --> $DIR/warn.rs:4:9
+  --> $DIR/warn.rs:7:9
    |
 LL | #![warn(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/tests/ui/macros/format-args-temporaries-in-write.stderr b/tests/ui/macros/format-args-temporaries-in-write.stderr
index 287cd7d6704..520b2ce5052 100644
--- a/tests/ui/macros/format-args-temporaries-in-write.stderr
+++ b/tests/ui/macros/format-args-temporaries-in-write.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `mutex` does not live long enough
   --> $DIR/format-args-temporaries-in-write.rs:41:27
    |
+LL |         let mutex = Mutex;
+   |             ----- binding `mutex` declared here
 LL |         write!(Out, "{}", mutex.lock()) /* no semicolon */
    |                           ^^^^^^^^^^^^
    |                           |
@@ -16,6 +18,8 @@ LL |     };
 error[E0597]: `mutex` does not live long enough
   --> $DIR/format-args-temporaries-in-write.rs:47:29
    |
+LL |         let mutex = Mutex;
+   |             ----- binding `mutex` declared here
 LL |         writeln!(Out, "{}", mutex.lock()) /* no semicolon */
    |                             ^^^^^^^^^^^^
    |                             |
diff --git a/tests/ui/macros/rfc-2011-nicer-assert-messages/non-consuming-methods-have-optimized-codegen.stdout b/tests/ui/macros/rfc-2011-nicer-assert-messages/non-consuming-methods-have-optimized-codegen.stdout
index 90f858f80e6..ad97f7a4a75 100644
--- a/tests/ui/macros/rfc-2011-nicer-assert-messages/non-consuming-methods-have-optimized-codegen.stdout
+++ b/tests/ui/macros/rfc-2011-nicer-assert-messages/non-consuming-methods-have-optimized-codegen.stdout
@@ -25,8 +25,8 @@ fn arbitrary_consuming_method_for_demonstration_purposes() {
 
 
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem as usize\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem as usize\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -41,8 +41,8 @@ fn addr_of() {
         if ::core::intrinsics::unlikely(!&*__local_bind0) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: &elem\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: &elem\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -57,8 +57,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 == 1)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem == 1\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem == 1\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -70,8 +70,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 >= 1)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem >= 1\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem >= 1\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -83,8 +83,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 > 0)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem > 0\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem > 0\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -96,8 +96,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 < 3)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem < 3\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem < 3\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -109,8 +109,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 <= 3)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem <= 3\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem <= 3\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -122,8 +122,8 @@ fn binary() {
         if ::core::intrinsics::unlikely(!(*__local_bind0 != 3)) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: elem != 3\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: elem != 3\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
@@ -138,8 +138,8 @@ fn unary() {
         if ::core::intrinsics::unlikely(!**__local_bind0) {
                 (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
                 {
-                    ::std::rt::panic_fmt(::core::fmt::Arguments::new_v1(&["Assertion failed: *elem\nWith captures:\n  elem = ",
-                                        "\n"], &[::core::fmt::ArgumentV1::new_debug(&__capture0)]))
+                    ::std::rt::panic_fmt(format_args!("Assertion failed: *elem\nWith captures:\n  elem = {0:?}\n",
+                            __capture0))
                 }
             }
     };
diff --git a/tests/ui/match/issue-74050-end-span.stderr b/tests/ui/match/issue-74050-end-span.stderr
index 59c091e44eb..0b3425f2b1a 100644
--- a/tests/ui/match/issue-74050-end-span.stderr
+++ b/tests/ui/match/issue-74050-end-span.stderr
@@ -4,6 +4,7 @@ error[E0597]: `arg` does not live long enough
 LL |     let _arg = match args.next() {
    |         ---- borrow later stored here
 LL |         Some(arg) => {
+   |              --- binding `arg` declared here
 LL |             match arg.to_str() {
    |                   ^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/mir/mir_codegen_ssa.rs b/tests/ui/mir/mir_codegen_ssa.rs
new file mode 100644
index 00000000000..5e2f10cefe9
--- /dev/null
+++ b/tests/ui/mir/mir_codegen_ssa.rs
@@ -0,0 +1,19 @@
+// build-pass
+// compile-flags: --crate-type=lib
+#![feature(custom_mir, core_intrinsics)]
+use std::intrinsics::mir::*;
+
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+pub fn f(a: u32) -> u32 {
+    mir!(
+        let x: u32;
+        {
+            // Previously code generation failed with ICE "use of .. before def ..." because the
+            // definition of x was incorrectly identified as dominating the use of x located in the
+            // same statement:
+            x = x + a;
+            RET = x;
+            Return()
+        }
+    )
+}
diff --git a/tests/ui/moves/move-fn-self-receiver.stderr b/tests/ui/moves/move-fn-self-receiver.stderr
index 7f69e5dcfb7..91d237b1d1a 100644
--- a/tests/ui/moves/move-fn-self-receiver.stderr
+++ b/tests/ui/moves/move-fn-self-receiver.stderr
@@ -75,6 +75,8 @@ LL |     fn use_pin_box_self(self: Pin<Box<Self>>) {}
 error[E0505]: cannot move out of `mut_foo` because it is borrowed
   --> $DIR/move-fn-self-receiver.rs:50:5
    |
+LL |     let mut mut_foo = Foo;
+   |         ----------- binding `mut_foo` declared here
 LL |     let ret = mut_foo.use_mut_self();
    |               ---------------------- borrow of `mut_foo` occurs here
 LL |     mut_foo;
diff --git a/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.fixed b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.fixed
new file mode 100644
index 00000000000..0b9a3bae961
--- /dev/null
+++ b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.fixed
@@ -0,0 +1,11 @@
+// run-rustfix
+use std::pin::Pin;
+
+fn foo(_: &mut ()) {}
+
+fn main() {
+    let mut uwu = ();
+    let mut r = Pin::new(&mut uwu);
+    foo(r.as_mut().get_mut());
+    foo(r.get_mut()); //~ ERROR use of moved value
+}
diff --git a/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.rs b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.rs
new file mode 100644
index 00000000000..0e952b06ee1
--- /dev/null
+++ b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.rs
@@ -0,0 +1,11 @@
+// run-rustfix
+use std::pin::Pin;
+
+fn foo(_: &mut ()) {}
+
+fn main() {
+    let mut uwu = ();
+    let mut r = Pin::new(&mut uwu);
+    foo(r.get_mut());
+    foo(r.get_mut()); //~ ERROR use of moved value
+}
diff --git a/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.stderr b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.stderr
new file mode 100644
index 00000000000..7e513b73c21
--- /dev/null
+++ b/tests/ui/moves/pin-mut-reborrow-infer-var-issue-107419.stderr
@@ -0,0 +1,20 @@
+error[E0382]: use of moved value: `r`
+  --> $DIR/pin-mut-reborrow-infer-var-issue-107419.rs:10:9
+   |
+LL |     let mut r = Pin::new(&mut uwu);
+   |         ----- move occurs because `r` has type `Pin<&mut ()>`, which does not implement the `Copy` trait
+LL |     foo(r.get_mut());
+   |           --------- `r` moved due to this method call
+LL |     foo(r.get_mut());
+   |         ^ value used here after move
+   |
+note: `Pin::<&'a mut T>::get_mut` takes ownership of the receiver `self`, which moves `r`
+  --> $SRC_DIR/core/src/pin.rs:LL:COL
+help: consider reborrowing the `Pin` instead of moving it
+   |
+LL |     foo(r.as_mut().get_mut());
+   |           +++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/tests/ui/mut/mut-pattern-internal-mutability.stderr b/tests/ui/mut/mut-pattern-internal-mutability.stderr
index 6583546aa5c..5f2074edb12 100644
--- a/tests/ui/mut/mut-pattern-internal-mutability.stderr
+++ b/tests/ui/mut/mut-pattern-internal-mutability.stderr
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `*foo` because it is borrowed
   --> $DIR/mut-pattern-internal-mutability.rs:13:5
    |
 LL |     let &mut ref x = foo;
-   |              ----- borrow of `*foo` occurs here
+   |              ----- `*foo` is borrowed here
 LL |     *foo += 1;
-   |     ^^^^^^^^^ assignment to borrowed `*foo` occurs here
+   |     ^^^^^^^^^ `*foo` is assigned to here but it was already borrowed
 LL |     drop(x);
    |          - borrow later used here
 
diff --git a/tests/ui/nll/borrowed-local-error.stderr b/tests/ui/nll/borrowed-local-error.stderr
index d629caa4353..1cca4077d82 100644
--- a/tests/ui/nll/borrowed-local-error.stderr
+++ b/tests/ui/nll/borrowed-local-error.stderr
@@ -4,6 +4,7 @@ error[E0597]: `v` does not live long enough
 LL |     let x = gimme({
    |             ----- borrow later used by call
 LL |         let v = (22,);
+   |             - binding `v` declared here
 LL |         &v
    |         ^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/nll/borrowed-match-issue-45045.stderr b/tests/ui/nll/borrowed-match-issue-45045.stderr
index 9d4682667dd..33e3eb79796 100644
--- a/tests/ui/nll/borrowed-match-issue-45045.stderr
+++ b/tests/ui/nll/borrowed-match-issue-45045.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `e` because it was mutably borrowed
   --> $DIR/borrowed-match-issue-45045.rs:12:11
    |
 LL |     let f = &mut e;
-   |             ------ borrow of `e` occurs here
+   |             ------ `e` is borrowed here
 LL |     let g = f;
 LL |     match e {
    |           ^ use of borrowed `e`
diff --git a/tests/ui/nll/capture-ref-in-struct.stderr b/tests/ui/nll/capture-ref-in-struct.stderr
index cdfe7f6db82..84b7ecf2f7d 100644
--- a/tests/ui/nll/capture-ref-in-struct.stderr
+++ b/tests/ui/nll/capture-ref-in-struct.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/capture-ref-in-struct.rs:18:16
    |
+LL |         let y = 22;
+   |             - binding `y` declared here
+...
 LL |             y: &y,
    |                ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/closure-access-spans.stderr b/tests/ui/nll/closure-access-spans.stderr
index 0a09353b8ec..035dd5a5610 100644
--- a/tests/ui/nll/closure-access-spans.stderr
+++ b/tests/ui/nll/closure-access-spans.stderr
@@ -38,7 +38,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/closure-access-spans.rs:23:13
    |
 LL |     let r = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     move || x;
    |             ^ use of borrowed `x`
 LL |     r.use_ref();
@@ -47,6 +47,8 @@ LL |     r.use_ref();
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/closure-access-spans.rs:29:5
    |
+LL | fn closure_move_capture_conflict(mut x: String) {
+   |                                  ----- binding `x` declared here
 LL |     let r = &x;
    |             -- borrow of `x` occurs here
 LL |     || x;
diff --git a/tests/ui/nll/closure-borrow-spans.stderr b/tests/ui/nll/closure-borrow-spans.stderr
index bada4e1b84b..cf0df5834cc 100644
--- a/tests/ui/nll/closure-borrow-spans.stderr
+++ b/tests/ui/nll/closure-borrow-spans.stderr
@@ -40,9 +40,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
 LL |     let f = || x;
    |             -- - borrow occurs due to use in closure
    |             |
-   |             borrow of `x` occurs here
+   |             `x` is borrowed here
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     f.use_ref();
    |     ----------- borrow later used here
 
@@ -52,7 +52,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
 LL |     let f = || x = 0;
    |             -- - borrow occurs due to use of `x` in closure
    |             |
-   |             borrow of `x` occurs here
+   |             `x` is borrowed here
 LL |     let y = x;
    |             ^ use of borrowed `x`
 LL |     f.use_ref();
@@ -100,9 +100,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
 LL |     let f = || x = 0;
    |             -- - borrow occurs due to use in closure
    |             |
-   |             borrow of `x` occurs here
+   |             `x` is borrowed here
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     f.use_ref();
    |     ----------- borrow later used here
 
@@ -160,9 +160,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
 LL |     let f = || *x = 0;
    |             -- -- borrow occurs due to use in closure
    |             |
-   |             borrow of `*x` occurs here
+   |             `*x` is borrowed here
 LL |     *x = 1;
-   |     ^^^^^^ assignment to borrowed `*x` occurs here
+   |     ^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |     f.use_ref();
    |     ----------- borrow later used here
 
diff --git a/tests/ui/nll/closure-requirements/escape-argument.stderr b/tests/ui/nll/closure-requirements/escape-argument.stderr
index f67c312b946..5a8462d4dc5 100644
--- a/tests/ui/nll/closure-requirements/escape-argument.stderr
+++ b/tests/ui/nll/closure-requirements/escape-argument.stderr
@@ -21,6 +21,9 @@ LL | fn test() {
 error[E0597]: `y` does not live long enough
   --> $DIR/escape-argument.rs:27:25
    |
+LL |         let y = 22;
+   |             - binding `y` declared here
+LL |         let mut closure = expect_sig(|p, y| *p = y);
 LL |         closure(&mut p, &y);
    |                         ^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr b/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
index 7991abeb7a8..721cd45ded9 100644
--- a/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
+++ b/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
@@ -53,6 +53,8 @@ LL | fn case2() {
 error[E0597]: `a` does not live long enough
   --> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:30:26
    |
+LL |       let a = 0;
+   |           - binding `a` declared here
 LL |       let cell = Cell::new(&a);
    |                            ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/closure-use-spans.stderr b/tests/ui/nll/closure-use-spans.stderr
index ad928f1bbc9..0e27e5f5f7c 100644
--- a/tests/ui/nll/closure-use-spans.stderr
+++ b/tests/ui/nll/closure-use-spans.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/closure-use-spans.rs:5:5
    |
 LL |     let y = &x;
-   |             -- borrow of `x` occurs here
+   |             -- `x` is borrowed here
 LL |     x = 0;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     || *y;
    |        -- borrow later captured here by closure
 
@@ -12,9 +12,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/closure-use-spans.rs:11:5
    |
 LL |     let y = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     x = 0;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     || *y = 1;
    |        -- borrow later captured here by closure
 
@@ -22,9 +22,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/closure-use-spans.rs:17:5
    |
 LL |     let y = &x;
-   |             -- borrow of `x` occurs here
+   |             -- `x` is borrowed here
 LL |     x = 0;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     move || *y;
    |             -- borrow later captured here by closure
 
diff --git a/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy-proj.stderr b/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy-proj.stderr
index 65be3b37e0e..862c925b468 100644
--- a/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy-proj.stderr
+++ b/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy-proj.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `s` does not live long enough
   --> $DIR/do-not-ignore-lifetime-bounds-in-copy-proj.rs:9:18
    |
+LL |     let s = 2;
+   |         - binding `s` declared here
 LL |     let a = (Foo(&s),);
    |                  ^^ borrowed value does not live long enough
 LL |     drop(a.0);
diff --git a/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy.stderr b/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy.stderr
index b811ba4fd0c..ebaf6d1244d 100644
--- a/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy.stderr
+++ b/tests/ui/nll/do-not-ignore-lifetime-bounds-in-copy.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `s` does not live long enough
   --> $DIR/do-not-ignore-lifetime-bounds-in-copy.rs:8:17
    |
+LL |     let s = 2;
+   |         - binding `s` declared here
 LL |     let a = Foo(&s);
    |                 ^^ borrowed value does not live long enough
 LL |     drop(a);
diff --git a/tests/ui/nll/dont-print-desugared.stderr b/tests/ui/nll/dont-print-desugared.stderr
index fad6121cbca..289b246e663 100644
--- a/tests/ui/nll/dont-print-desugared.stderr
+++ b/tests/ui/nll/dont-print-desugared.stderr
@@ -10,6 +10,7 @@ error[E0597]: `y` does not live long enough
 LL |     for ref mut d in v {
    |                      - a temporary with access to the borrow is created here ...
 LL |         let y = ();
+   |             - binding `y` declared here
 LL |         *d = D(&y);
    |                ^^ borrowed value does not live long enough
 LL |     }
diff --git a/tests/ui/nll/drop-no-may-dangle.stderr b/tests/ui/nll/drop-no-may-dangle.stderr
index cb280880950..0ddb7adbb38 100644
--- a/tests/ui/nll/drop-no-may-dangle.stderr
+++ b/tests/ui/nll/drop-no-may-dangle.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `v[_]` because it is borrowed
   --> $DIR/drop-no-may-dangle.rs:18:9
    |
 LL |     let p: WrapMayNotDangle<&usize> = WrapMayNotDangle { value: &v[0] };
-   |                                                                 ----- borrow of `v[_]` occurs here
+   |                                                                 ----- `v[_]` is borrowed here
 ...
 LL |         v[0] += 1;
-   |         ^^^^^^^^^ assignment to borrowed `v[_]` occurs here
+   |         ^^^^^^^^^ `v[_]` is assigned to here but it was already borrowed
 ...
 LL | }
    | - borrow might be used here, when `p` is dropped and runs the `Drop` code for type `WrapMayNotDangle`
@@ -14,10 +14,10 @@ error[E0506]: cannot assign to `v[_]` because it is borrowed
   --> $DIR/drop-no-may-dangle.rs:21:5
    |
 LL |     let p: WrapMayNotDangle<&usize> = WrapMayNotDangle { value: &v[0] };
-   |                                                                 ----- borrow of `v[_]` occurs here
+   |                                                                 ----- `v[_]` is borrowed here
 ...
 LL |     v[0] += 1;
-   |     ^^^^^^^^^ assignment to borrowed `v[_]` occurs here
+   |     ^^^^^^^^^ `v[_]` is assigned to here but it was already borrowed
 LL | }
    | - borrow might be used here, when `p` is dropped and runs the `Drop` code for type `WrapMayNotDangle`
 
diff --git a/tests/ui/nll/guarantor-issue-46974.stderr b/tests/ui/nll/guarantor-issue-46974.stderr
index 8854dd8d68c..7edc3dcc5cd 100644
--- a/tests/ui/nll/guarantor-issue-46974.stderr
+++ b/tests/ui/nll/guarantor-issue-46974.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `*s` because it is borrowed
   --> $DIR/guarantor-issue-46974.rs:7:5
    |
 LL |     let t = &mut *s; // this borrow should last for the entire function
-   |             ------- borrow of `*s` occurs here
+   |             ------- `*s` is borrowed here
 LL |     let x = &t.0;
 LL |     *s = (2,);
-   |     ^^^^^^^^^ assignment to borrowed `*s` occurs here
+   |     ^^^^^^^^^ `*s` is assigned to here but it was already borrowed
 LL |     *x
    |     -- borrow later used here
 
diff --git a/tests/ui/nll/issue-27282-move-ref-mut-into-guard.stderr b/tests/ui/nll/issue-27282-move-ref-mut-into-guard.stderr
index 45119018d4e..4a512560c87 100644
--- a/tests/ui/nll/issue-27282-move-ref-mut-into-guard.stderr
+++ b/tests/ui/nll/issue-27282-move-ref-mut-into-guard.stderr
@@ -4,7 +4,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |             if { (|| { let bar = foo; bar.take() })(); false } => {},
    |                   ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |                   |
-   |                   move out of `foo` occurs here
+   |                   `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
@@ -14,7 +14,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |             if let Some(()) = { (|| { let bar = foo; bar.take() })(); None } => {},
    |                                  ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |                                  |
-   |                                  move out of `foo` occurs here
+   |                                  `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
diff --git a/tests/ui/nll/issue-27282-mutation-in-guard.stderr b/tests/ui/nll/issue-27282-mutation-in-guard.stderr
index 1ba696593af..0b5d723172c 100644
--- a/tests/ui/nll/issue-27282-mutation-in-guard.stderr
+++ b/tests/ui/nll/issue-27282-mutation-in-guard.stderr
@@ -4,7 +4,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |                 (|| { let bar = foo; bar.take() })();
    |                  ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |                  |
-   |                  move out of `foo` occurs here
+   |                  `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
@@ -14,7 +14,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |                 (|| { let bar = foo; bar.take() })();
    |                  ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |                  |
-   |                  move out of `foo` occurs here
+   |                  `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
diff --git a/tests/ui/nll/issue-27868.stderr b/tests/ui/nll/issue-27868.stderr
index e0b3b5494d0..204eda3d267 100644
--- a/tests/ui/nll/issue-27868.stderr
+++ b/tests/ui/nll/issue-27868.stderr
@@ -4,10 +4,10 @@ error[E0506]: cannot assign to `vecvec` because it is borrowed
 LL |       vecvec[0] += {
    |       ------
    |       |
-   |  _____borrow of `vecvec` occurs here
+   |  _____`vecvec` is borrowed here
    | |
 LL | |         vecvec = vec![];
-   | |         ^^^^^^ assignment to borrowed `vecvec` occurs here
+   | |         ^^^^^^ `vecvec` is assigned to here but it was already borrowed
 LL | |
 LL | |         0
 LL | |     };
diff --git a/tests/ui/nll/issue-46036.stderr b/tests/ui/nll/issue-46036.stderr
index e6e95ee6136..f337e234550 100644
--- a/tests/ui/nll/issue-46036.stderr
+++ b/tests/ui/nll/issue-46036.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/issue-46036.rs:8:24
    |
+LL |     let a = 3;
+   |         - binding `a` declared here
 LL |     let foo = Foo { x: &a };
    |                        ^^
    |                        |
diff --git a/tests/ui/nll/issue-48803.stderr b/tests/ui/nll/issue-48803.stderr
index 2f94039c0c3..e24606e0b53 100644
--- a/tests/ui/nll/issue-48803.stderr
+++ b/tests/ui/nll/issue-48803.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/issue-48803.rs:10:5
    |
 LL |     let y = &x;
-   |             -- borrow of `x` occurs here
+   |             -- `x` is borrowed here
 ...
 LL |     x = "modified";
-   |     ^^^^^^^^^^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^^^^^^^^^^ `x` is assigned to here but it was already borrowed
 LL |
 LL |     println!("{}", w); // prints "modified"
    |                    - borrow later used here
diff --git a/tests/ui/nll/issue-52534-2.stderr b/tests/ui/nll/issue-52534-2.stderr
index ac385e056b9..35d39bb6e90 100644
--- a/tests/ui/nll/issue-52534-2.stderr
+++ b/tests/ui/nll/issue-52534-2.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/issue-52534-2.rs:6:13
    |
+LL |         let x = 32;
+   |             - binding `x` declared here
 LL |         y = &x
    |             ^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/nll/issue-52663-trait-object.stderr b/tests/ui/nll/issue-52663-trait-object.stderr
index 5cedea6e665..338f6484132 100644
--- a/tests/ui/nll/issue-52663-trait-object.stderr
+++ b/tests/ui/nll/issue-52663-trait-object.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `tmp0` does not live long enough
   --> $DIR/issue-52663-trait-object.rs:12:20
    |
+LL |         let tmp0 = 3;
+   |             ---- binding `tmp0` declared here
 LL |         let tmp1 = &tmp0;
    |                    ^^^^^ borrowed value does not live long enough
 LL |         Box::new(tmp1) as Box<dyn Foo + '_>
diff --git a/tests/ui/nll/issue-54382-use-span-of-tail-of-block.stderr b/tests/ui/nll/issue-54382-use-span-of-tail-of-block.stderr
index d8f43cbc92a..4a32c777a86 100644
--- a/tests/ui/nll/issue-54382-use-span-of-tail-of-block.stderr
+++ b/tests/ui/nll/issue-54382-use-span-of-tail-of-block.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `_thing1` does not live long enough
   --> $DIR/issue-54382-use-span-of-tail-of-block.rs:7:29
    |
+LL |         let mut _thing1 = D(Box::new("thing1"));
+   |             ----------- binding `_thing1` declared here
+...
 LL |             D("other").next(&_thing1)
    |             ----------------^^^^^^^^-
    |             |               |
diff --git a/tests/ui/nll/issue-54556-niconii.stderr b/tests/ui/nll/issue-54556-niconii.stderr
index a8e1edc5497..d41d462f2bc 100644
--- a/tests/ui/nll/issue-54556-niconii.stderr
+++ b/tests/ui/nll/issue-54556-niconii.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `counter` does not live long enough
   --> $DIR/issue-54556-niconii.rs:22:20
    |
+LL |     let counter = Mutex;
+   |         ------- binding `counter` declared here
+LL |
 LL |     if let Ok(_) = counter.lock() { }
    |                    ^^^^^^^^^^^^^^
    |                    |
diff --git a/tests/ui/nll/issue-54556-stephaneyfx.stderr b/tests/ui/nll/issue-54556-stephaneyfx.stderr
index 036a7a0abfd..f9e82cb003f 100644
--- a/tests/ui/nll/issue-54556-stephaneyfx.stderr
+++ b/tests/ui/nll/issue-54556-stephaneyfx.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `stmt` does not live long enough
   --> $DIR/issue-54556-stephaneyfx.rs:27:21
    |
+LL |     let stmt = Statement;
+   |         ---- binding `stmt` declared here
 LL |     let rows = Rows(&stmt);
    |                     ^^^^^ borrowed value does not live long enough
 LL |     rows.map(|row| row).next()
diff --git a/tests/ui/nll/issue-54556-temps-in-tail-diagnostic.stderr b/tests/ui/nll/issue-54556-temps-in-tail-diagnostic.stderr
index 92f5ffdf388..4eae9fdcde0 100644
--- a/tests/ui/nll/issue-54556-temps-in-tail-diagnostic.stderr
+++ b/tests/ui/nll/issue-54556-temps-in-tail-diagnostic.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `_thing1` does not live long enough
   --> $DIR/issue-54556-temps-in-tail-diagnostic.rs:5:11
    |
+LL |         let mut _thing1 = D(Box::new("thing1"));
+   |             ----------- binding `_thing1` declared here
+LL |         // D("other").next(&_thing1).end()
 LL |         D(&_thing1).end()
    |         --^^^^^^^^-
    |         | |
diff --git a/tests/ui/nll/issue-54556-used-vs-unused-tails.stderr b/tests/ui/nll/issue-54556-used-vs-unused-tails.stderr
index 25226e29673..a2a7a848654 100644
--- a/tests/ui/nll/issue-54556-used-vs-unused-tails.stderr
+++ b/tests/ui/nll/issue-54556-used-vs-unused-tails.stderr
@@ -2,11 +2,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:10:55
    |
 LL |     {              let mut _t1 = D(Box::new("t1")); D(&_t1).end()    } ; // suggest `;`
-   |                                                     --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |              |
-   |                                                     | |              `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |              |
+   |                        |                            | |              `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -17,11 +18,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:13:55
    |
 LL |     {            { let mut _t1 = D(Box::new("t1")); D(&_t1).end() }  } ; // suggest `;`
-   |                                                     --^^^^-       -    - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |           |
-   |                                                     | |           `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-       -    - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |           |
+   |                        |                            | |           `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -32,11 +34,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:16:55
    |
 LL |     {            { let mut _t1 = D(Box::new("t1")); D(&_t1).end() }; }   // suggest `;`
-   |                                                     --^^^^-       -- ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |           |
-   |                                                     | |           `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-       -- ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |           |
+   |                        |                            | |           `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -47,11 +50,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:19:55
    |
 LL |     let _ =      { let mut _t1 = D(Box::new("t1")); D(&_t1).end()    } ; // suggest `;`
-   |                                                     --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |              |
-   |                                                     | |              `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |              |
+   |                        |                            | |              `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -62,11 +66,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:22:55
    |
 LL |     let _u =     { let mut _t1 = D(Box::new("t1")); D(&_t1).unit()   } ; // suggest `;`
-   |                                                     --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |              |
-   |                                                     | |              `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |              |
+   |                        |                            | |              `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -77,11 +82,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:25:55
    |
 LL |     let _x =     { let mut _t1 = D(Box::new("t1")); D(&_t1).end()    } ; // `let x = ...; x`
-   |                                                     --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |              |
-   |                                                     | |              `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-          - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |              |
+   |                        |                            | |              `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
    = note: the temporary is part of an expression at the end of a block;
            consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
@@ -94,11 +100,12 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:30:55
    |
 LL |     _y =         { let mut _t1 = D(Box::new("t1")); D(&_t1).end() } ; // `let x = ...; x`
-   |                                                     --^^^^-       - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | |           |
-   |                                                     | |           `_t1` dropped here while still borrowed
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-       - - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | |           |
+   |                        |                            | |           `_t1` dropped here while still borrowed
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
    = note: the temporary is part of an expression at the end of a block;
            consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
@@ -111,12 +118,13 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:37:55
    |
 LL | fn f_local_ref() { let mut _t1 = D(Box::new("t1")); D(&_t1).unit()   }  // suggest `;`
-   |                                                     --^^^^-          -
-   |                                                     | |              |
-   |                                                     | |              `_t1` dropped here while still borrowed
-   |                                                     | |              ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-          -
+   |                        |                            | |              |
+   |                        |                            | |              `_t1` dropped here while still borrowed
+   |                        |                            | |              ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
 help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
    |
@@ -127,12 +135,13 @@ error[E0597]: `_t1` does not live long enough
   --> $DIR/issue-54556-used-vs-unused-tails.rs:40:55
    |
 LL | fn f() -> String { let mut _t1 = D(Box::new("t1")); D(&_t1).end()   }   // `let x = ...; x`
-   |                                                     --^^^^-         -
-   |                                                     | |             |
-   |                                                     | |             `_t1` dropped here while still borrowed
-   |                                                     | |             ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
-   |                                                     | borrowed value does not live long enough
-   |                                                     a temporary with access to the borrow is created here ...
+   |                        -------                      --^^^^-         -
+   |                        |                            | |             |
+   |                        |                            | |             `_t1` dropped here while still borrowed
+   |                        |                            | |             ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `D`
+   |                        |                            | borrowed value does not live long enough
+   |                        |                            a temporary with access to the borrow is created here ...
+   |                        binding `_t1` declared here
    |
    = note: the temporary is part of an expression at the end of a block;
            consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
diff --git a/tests/ui/nll/issue-54556-wrap-it-up.stderr b/tests/ui/nll/issue-54556-wrap-it-up.stderr
index 9f27fac15a7..adc419ae515 100644
--- a/tests/ui/nll/issue-54556-wrap-it-up.stderr
+++ b/tests/ui/nll/issue-54556-wrap-it-up.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/issue-54556-wrap-it-up.rs:27:5
    |
 LL |     let wrap = Wrap { p: &mut x };
-   |                          ------ borrow of `x` occurs here
+   |                          ------ `x` is borrowed here
 ...
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL | }
    | - borrow might be used here, when `foo` is dropped and runs the destructor for type `Foo<'_>`
 
diff --git a/tests/ui/nll/issue-55511.stderr b/tests/ui/nll/issue-55511.stderr
index bf3e58e8cdb..ecb9ef0aef9 100644
--- a/tests/ui/nll/issue-55511.stderr
+++ b/tests/ui/nll/issue-55511.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/issue-55511.rs:13:28
    |
+LL |     let a = 22;
+   |         - binding `a` declared here
 LL |     let b = Some(Cell::new(&a));
    |                            ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/issue-57989.stderr b/tests/ui/nll/issue-57989.stderr
index 31f40d8252e..d5effd6f346 100644
--- a/tests/ui/nll/issue-57989.stderr
+++ b/tests/ui/nll/issue-57989.stderr
@@ -13,9 +13,9 @@ error[E0506]: cannot assign to `*x` because it is borrowed
   --> $DIR/issue-57989.rs:5:5
    |
 LL |     let g = &x;
-   |             -- borrow of `*x` occurs here
+   |             -- `*x` is borrowed here
 LL |     *x = 0;
-   |     ^^^^^^ assignment to borrowed `*x` occurs here
+   |     ^^^^^^ `*x` is assigned to here but it was already borrowed
 LL |
 LL |     g;
    |     - borrow later used here
diff --git a/tests/ui/nll/issue-68550.stderr b/tests/ui/nll/issue-68550.stderr
index e234ebb04e1..851e3628748 100644
--- a/tests/ui/nll/issue-68550.stderr
+++ b/tests/ui/nll/issue-68550.stderr
@@ -2,7 +2,9 @@ error[E0597]: `x` does not live long enough
   --> $DIR/issue-68550.rs:12:20
    |
 LL | fn run<'a, A>(x: A)
-   |        -- lifetime `'a` defined here
+   |        --     - binding `x` declared here
+   |        |
+   |        lifetime `'a` defined here
 ...
 LL |     let _: &'a A = &x;
    |            -----   ^^ borrowed value does not live long enough
diff --git a/tests/ui/nll/issue-69114-static-mut-ty.stderr b/tests/ui/nll/issue-69114-static-mut-ty.stderr
index 5e55cb502ca..1b41230d7ba 100644
--- a/tests/ui/nll/issue-69114-static-mut-ty.stderr
+++ b/tests/ui/nll/issue-69114-static-mut-ty.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `n` does not live long enough
   --> $DIR/issue-69114-static-mut-ty.rs:19:15
    |
+LL |     let n = 42;
+   |         - binding `n` declared here
+LL |     unsafe {
 LL |         BAR = &n;
    |         ------^^
    |         |     |
@@ -13,6 +16,9 @@ LL | }
 error[E0597]: `n` does not live long enough
   --> $DIR/issue-69114-static-mut-ty.rs:27:22
    |
+LL |     let n = 42;
+   |         - binding `n` declared here
+LL |     unsafe {
 LL |         BAR_ELIDED = &n;
    |         -------------^^
    |         |            |
diff --git a/tests/ui/nll/issue-69114-static-ty.stderr b/tests/ui/nll/issue-69114-static-ty.stderr
index 0815e74b553..9215e850f7d 100644
--- a/tests/ui/nll/issue-69114-static-ty.stderr
+++ b/tests/ui/nll/issue-69114-static-ty.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `n` does not live long enough
   --> $DIR/issue-69114-static-ty.rs:7:9
    |
+LL |     let n = 42;
+   |         - binding `n` declared here
 LL |     FOO(&n);
    |     ----^^-
    |     |   |
diff --git a/tests/ui/nll/loan_ends_mid_block_pair.stderr b/tests/ui/nll/loan_ends_mid_block_pair.stderr
index eb8442b31d7..58e378ab021 100644
--- a/tests/ui/nll/loan_ends_mid_block_pair.stderr
+++ b/tests/ui/nll/loan_ends_mid_block_pair.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `data.0` because it is borrowed
   --> $DIR/loan_ends_mid_block_pair.rs:12:5
    |
 LL |     let c = &mut data.0;
-   |             ----------- borrow of `data.0` occurs here
+   |             ----------- `data.0` is borrowed here
 LL |     capitalize(c);
 LL |     data.0 = 'e';
-   |     ^^^^^^^^^^^^ assignment to borrowed `data.0` occurs here
+   |     ^^^^^^^^^^^^ `data.0` is assigned to here but it was already borrowed
 ...
 LL |     capitalize(c);
    |                - borrow later used here
diff --git a/tests/ui/nll/local-outlives-static-via-hrtb.stderr b/tests/ui/nll/local-outlives-static-via-hrtb.stderr
index f5c10f3ddea..a6b3328b5a2 100644
--- a/tests/ui/nll/local-outlives-static-via-hrtb.stderr
+++ b/tests/ui/nll/local-outlives-static-via-hrtb.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `local` does not live long enough
   --> $DIR/local-outlives-static-via-hrtb.rs:24:28
    |
+LL |     let local = 0;
+   |         ----- binding `local` declared here
 LL |     assert_static_via_hrtb(&local);
    |     -----------------------^^^^^^-
    |     |                      |
@@ -19,6 +21,9 @@ LL | fn assert_static_via_hrtb<G>(_: G) where for<'a> G: Outlives<'a> {}
 error[E0597]: `local` does not live long enough
   --> $DIR/local-outlives-static-via-hrtb.rs:25:45
    |
+LL |     let local = 0;
+   |         ----- binding `local` declared here
+LL |     assert_static_via_hrtb(&local);
 LL |     assert_static_via_hrtb_with_assoc_type(&&local);
    |     ----------------------------------------^^^^^^-
    |     |                                       |
diff --git a/tests/ui/nll/match-cfg-fake-edges2.stderr b/tests/ui/nll/match-cfg-fake-edges2.stderr
index c6d15a936d8..36f2cd0b85d 100644
--- a/tests/ui/nll/match-cfg-fake-edges2.stderr
+++ b/tests/ui/nll/match-cfg-fake-edges2.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `y.1` because it was mutably borrowed
   --> $DIR/match-cfg-fake-edges2.rs:8:5
    |
 LL |     let r = &mut y.1;
-   |             -------- borrow of `y.1` occurs here
+   |             -------- `y.1` is borrowed here
 ...
 LL |     match y {
    |     ^^^^^^^ use of borrowed `y.1`
diff --git a/tests/ui/nll/match-guards-always-borrow.stderr b/tests/ui/nll/match-guards-always-borrow.stderr
index fa01d3a6fd1..afd853c403e 100644
--- a/tests/ui/nll/match-guards-always-borrow.stderr
+++ b/tests/ui/nll/match-guards-always-borrow.stderr
@@ -4,7 +4,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |             (|| { let bar = foo; bar.take() })();
    |              ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |              |
-   |              move out of `foo` occurs here
+   |              `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
@@ -14,7 +14,7 @@ error[E0507]: cannot move out of `foo` in pattern guard
 LL |             (|| { let bar = foo; bar.take() })();
    |              ^^             --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
    |              |
-   |              move out of `foo` occurs here
+   |              `foo` is moved here
    |
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
diff --git a/tests/ui/nll/match-guards-partially-borrow.stderr b/tests/ui/nll/match-guards-partially-borrow.stderr
index 60b8dee71a8..7bdcbcb9c6e 100644
--- a/tests/ui/nll/match-guards-partially-borrow.stderr
+++ b/tests/ui/nll/match-guards-partially-borrow.stderr
@@ -74,9 +74,9 @@ error[E0506]: cannot assign to `t` because it is borrowed
   --> $DIR/match-guards-partially-borrow.rs:225:13
    |
 LL |         s if {
-   |         - borrow of `t` occurs here
+   |         - `t` is borrowed here
 LL |             t = !t;
-   |             ^^^^^^ assignment to borrowed `t` occurs here
+   |             ^^^^^^ `t` is assigned to here but it was already borrowed
 LL |             false
 LL |         } => (), // What value should `s` have in the arm?
    |         - borrow later used here
@@ -85,9 +85,9 @@ error[E0506]: cannot assign to `t` because it is borrowed
   --> $DIR/match-guards-partially-borrow.rs:235:13
    |
 LL |         s if let Some(()) = {
-   |         - borrow of `t` occurs here
+   |         - `t` is borrowed here
 LL |             t = !t;
-   |             ^^^^^^ assignment to borrowed `t` occurs here
+   |             ^^^^^^ `t` is assigned to here but it was already borrowed
 LL |             None
 LL |         } => (), // What value should `s` have in the arm?
    |         - borrow later used here
diff --git a/tests/ui/nll/match-on-borrowed.stderr b/tests/ui/nll/match-on-borrowed.stderr
index 32666529f3f..9273484565a 100644
--- a/tests/ui/nll/match-on-borrowed.stderr
+++ b/tests/ui/nll/match-on-borrowed.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `e` because it was mutably borrowed
   --> $DIR/match-on-borrowed.rs:47:11
    |
 LL |         E::V(ref mut x, _) => x,
-   |              --------- borrow of `e.0` occurs here
+   |              --------- `e.0` is borrowed here
 ...
 LL |     match e { // Don't know that E uses a tag for its discriminant
    |           ^ use of borrowed `e.0`
@@ -14,7 +14,7 @@ error[E0503]: cannot use `*f` because it was mutably borrowed
   --> $DIR/match-on-borrowed.rs:61:11
    |
 LL |         E::V(ref mut x, _) => x,
-   |              --------- borrow of `f.0` occurs here
+   |              --------- `f.0` is borrowed here
 ...
 LL |     match f { // Don't know that E uses a tag for its discriminant
    |           ^ use of borrowed `f.0`
@@ -26,7 +26,7 @@ error[E0503]: cannot use `t` because it was mutably borrowed
   --> $DIR/match-on-borrowed.rs:81:5
    |
 LL |     let x = &mut t;
-   |             ------ borrow of `t` occurs here
+   |             ------ `t` is borrowed here
 LL |     match t {
    |     ^^^^^^^ use of borrowed `t`
 ...
diff --git a/tests/ui/nll/maybe-initialized-drop-implicit-fragment-drop.stderr b/tests/ui/nll/maybe-initialized-drop-implicit-fragment-drop.stderr
index 80e29780746..55646b9dca9 100644
--- a/tests/ui/nll/maybe-initialized-drop-implicit-fragment-drop.stderr
+++ b/tests/ui/nll/maybe-initialized-drop-implicit-fragment-drop.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/maybe-initialized-drop-implicit-fragment-drop.rs:17:5
    |
 LL |     let wrap = Wrap { p: &mut x };
-   |                          ------ borrow of `x` occurs here
+   |                          ------ `x` is borrowed here
 ...
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     // FIXME ^ Should not error in the future with implicit dtors, only manually implemented ones
 LL | }
    | - borrow might be used here, when `foo` is dropped and runs the destructor for type `Foo<'_>`
diff --git a/tests/ui/nll/maybe-initialized-drop-with-fragment.stderr b/tests/ui/nll/maybe-initialized-drop-with-fragment.stderr
index 14074472eaf..c89f94a7894 100644
--- a/tests/ui/nll/maybe-initialized-drop-with-fragment.stderr
+++ b/tests/ui/nll/maybe-initialized-drop-with-fragment.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/maybe-initialized-drop-with-fragment.rs:19:5
    |
 LL |     let wrap = Wrap { p: &mut x };
-   |                          ------ borrow of `x` occurs here
+   |                          ------ `x` is borrowed here
 ...
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL | }
    | - borrow might be used here, when `foo` is dropped and runs the destructor for type `Foo<'_>`
 
diff --git a/tests/ui/nll/maybe-initialized-drop-with-uninitialized-fragments.stderr b/tests/ui/nll/maybe-initialized-drop-with-uninitialized-fragments.stderr
index 91c0afc1dba..90db13bc578 100644
--- a/tests/ui/nll/maybe-initialized-drop-with-uninitialized-fragments.stderr
+++ b/tests/ui/nll/maybe-initialized-drop-with-uninitialized-fragments.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/maybe-initialized-drop-with-uninitialized-fragments.rs:20:5
    |
 LL |     let wrap = Wrap { p: &mut x };
-   |                          ------ borrow of `x` occurs here
+   |                          ------ `x` is borrowed here
 ...
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL |     // FIXME ^ This currently errors and it should not.
 LL | }
    | - borrow might be used here, when `foo` is dropped and runs the destructor for type `Foo<'_>`
diff --git a/tests/ui/nll/maybe-initialized-drop.stderr b/tests/ui/nll/maybe-initialized-drop.stderr
index 9825ba4611b..15a53a09af8 100644
--- a/tests/ui/nll/maybe-initialized-drop.stderr
+++ b/tests/ui/nll/maybe-initialized-drop.stderr
@@ -2,9 +2,9 @@ error[E0506]: cannot assign to `x` because it is borrowed
   --> $DIR/maybe-initialized-drop.rs:14:5
    |
 LL |     let wrap = Wrap { p: &mut x };
-   |                          ------ borrow of `x` occurs here
+   |                          ------ `x` is borrowed here
 LL |     x = 1;
-   |     ^^^^^ assignment to borrowed `x` occurs here
+   |     ^^^^^ `x` is assigned to here but it was already borrowed
 LL | }
    | - borrow might be used here, when `wrap` is dropped and runs the `Drop` code for type `Wrap`
 
diff --git a/tests/ui/nll/polonius/polonius-smoke-test.stderr b/tests/ui/nll/polonius/polonius-smoke-test.stderr
index fa1a6a9c957..534813b2d9f 100644
--- a/tests/ui/nll/polonius/polonius-smoke-test.stderr
+++ b/tests/ui/nll/polonius/polonius-smoke-test.stderr
@@ -8,7 +8,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/polonius-smoke-test.rs:12:13
    |
 LL |     let y = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     let z = x;
    |             ^ use of borrowed `x`
 LL |     let w = y;
@@ -18,7 +18,9 @@ error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/polonius-smoke-test.rs:18:13
    |
 LL | pub fn use_while_mut_fr(x: &mut i32) -> &mut i32 {
-   |                            - let's call the lifetime of this reference `'1`
+   |                         -  - let's call the lifetime of this reference `'1`
+   |                         |
+   |                         binding `x` declared here
 LL |     let y = &mut *x;
    |             ------- borrow of `*x` occurs here
 LL |     let z = x;
@@ -29,6 +31,8 @@ LL |     y
 error[E0505]: cannot move out of `s` because it is borrowed
   --> $DIR/polonius-smoke-test.rs:42:5
    |
+LL |     let s = &mut 1;
+   |         - binding `s` declared here
 LL |     let r = &mut *s;
    |             ------- borrow of `*s` occurs here
 LL |     let tmp = foo(&r);
diff --git a/tests/ui/nll/promoted-bounds.stderr b/tests/ui/nll/promoted-bounds.stderr
index df347f4e7f0..d111256b845 100644
--- a/tests/ui/nll/promoted-bounds.stderr
+++ b/tests/ui/nll/promoted-bounds.stderr
@@ -4,6 +4,7 @@ error[E0597]: `l` does not live long enough
 LL |     let ptr = {
    |         --- borrow later stored here
 LL |         let l = 3;
+   |             - binding `l` declared here
 LL |         let b = &l;
    |                 ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/reference-carried-through-struct-field.stderr b/tests/ui/nll/reference-carried-through-struct-field.stderr
index 56d878e4303..5672b9cd7e9 100644
--- a/tests/ui/nll/reference-carried-through-struct-field.stderr
+++ b/tests/ui/nll/reference-carried-through-struct-field.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/reference-carried-through-struct-field.rs:6:5
    |
 LL |     let wrapper = Wrap { w: &mut x };
-   |                             ------ borrow of `x` occurs here
+   |                             ------ `x` is borrowed here
 LL |     x += 1;
    |     ^^^^^^ use of borrowed `x`
 LL |     *wrapper.w += 1;
diff --git a/tests/ui/nll/relate_tys/var-appears-twice.stderr b/tests/ui/nll/relate_tys/var-appears-twice.stderr
index d032ce6f213..ff6ea598ff4 100644
--- a/tests/ui/nll/relate_tys/var-appears-twice.stderr
+++ b/tests/ui/nll/relate_tys/var-appears-twice.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `b` does not live long enough
   --> $DIR/var-appears-twice.rs:20:38
    |
+LL |     let b = 44;
+   |         - binding `b` declared here
+...
 LL |     let x: DoubleCell<_> = make_cell(&b);
    |            -------------             ^^ borrowed value does not live long enough
    |            |
diff --git a/tests/ui/nll/user-annotations/adt-brace-enums.stderr b/tests/ui/nll/user-annotations/adt-brace-enums.stderr
index 253e3825110..9e94fd5a782 100644
--- a/tests/ui/nll/user-annotations/adt-brace-enums.stderr
+++ b/tests/ui/nll/user-annotations/adt-brace-enums.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-brace-enums.rs:25:48
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeEnum::SomeVariant::<&'static u32> { t: &c };
    |                                                ^^
    |                                                |
@@ -15,6 +17,7 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeEnum::SomeVariant::<&'a u32> { t: &c };
    |                                           ^^
    |                                           |
diff --git a/tests/ui/nll/user-annotations/adt-brace-structs.stderr b/tests/ui/nll/user-annotations/adt-brace-structs.stderr
index 8b9d1705df6..cbb7f6a55a9 100644
--- a/tests/ui/nll/user-annotations/adt-brace-structs.stderr
+++ b/tests/ui/nll/user-annotations/adt-brace-structs.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-brace-structs.rs:23:37
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeStruct::<&'static u32> { t: &c };
    |                                     ^^
    |                                     |
@@ -15,6 +17,7 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeStruct::<&'a u32> { t: &c };
    |                                ^^
    |                                |
diff --git a/tests/ui/nll/user-annotations/adt-nullary-enums.stderr b/tests/ui/nll/user-annotations/adt-nullary-enums.stderr
index 3326fa521fc..bca85a90d19 100644
--- a/tests/ui/nll/user-annotations/adt-nullary-enums.stderr
+++ b/tests/ui/nll/user-annotations/adt-nullary-enums.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-nullary-enums.rs:33:41
    |
+LL |       let c = 66;
+   |           - binding `c` declared here
 LL | /     combine(
 LL | |         SomeEnum::SomeVariant(Cell::new(&c)),
    | |                                         ^^ borrowed value does not live long enough
@@ -15,7 +17,9 @@ error[E0597]: `c` does not live long enough
    |
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
-...
+LL |     let c = 66;
+   |         - binding `c` declared here
+LL |     combine(
 LL |         SomeEnum::SomeVariant(Cell::new(&c)),
    |                               ----------^^-
    |                               |         |
diff --git a/tests/ui/nll/user-annotations/adt-tuple-enums.stderr b/tests/ui/nll/user-annotations/adt-tuple-enums.stderr
index 2fa7042631d..d2d85ec2b9b 100644
--- a/tests/ui/nll/user-annotations/adt-tuple-enums.stderr
+++ b/tests/ui/nll/user-annotations/adt-tuple-enums.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-tuple-enums.rs:28:43
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeEnum::SomeVariant::<&'static u32>(&c);
    |                                           ^^
    |                                           |
@@ -15,6 +17,7 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeEnum::SomeVariant::<&'a u32>(&c);
    |                                      ^^
    |                                      |
diff --git a/tests/ui/nll/user-annotations/adt-tuple-struct-calls.stderr b/tests/ui/nll/user-annotations/adt-tuple-struct-calls.stderr
index 9664fb9f548..b7bc2a10b70 100644
--- a/tests/ui/nll/user-annotations/adt-tuple-struct-calls.stderr
+++ b/tests/ui/nll/user-annotations/adt-tuple-struct-calls.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-tuple-struct-calls.rs:27:7
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
+LL |     let f = SomeStruct::<&'static u32>;
 LL |     f(&c);
    |     --^^-
    |     | |
@@ -14,7 +17,9 @@ error[E0597]: `c` does not live long enough
    |
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
-...
+LL |     let c = 66;
+   |         - binding `c` declared here
+LL |     let f = SomeStruct::<&'a u32>;
 LL |     f(&c);
    |     --^^-
    |     | |
diff --git a/tests/ui/nll/user-annotations/adt-tuple-struct.stderr b/tests/ui/nll/user-annotations/adt-tuple-struct.stderr
index 76b5252258c..97d39da265f 100644
--- a/tests/ui/nll/user-annotations/adt-tuple-struct.stderr
+++ b/tests/ui/nll/user-annotations/adt-tuple-struct.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/adt-tuple-struct.rs:23:32
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeStruct::<&'static u32>(&c);
    |                                ^^
    |                                |
@@ -15,6 +17,7 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     SomeStruct::<&'a u32>(&c);
    |                           ^^
    |                           |
diff --git a/tests/ui/nll/user-annotations/cast_static_lifetime.stderr b/tests/ui/nll/user-annotations/cast_static_lifetime.stderr
index 4599d04e7e2..3b9363c41f2 100644
--- a/tests/ui/nll/user-annotations/cast_static_lifetime.stderr
+++ b/tests/ui/nll/user-annotations/cast_static_lifetime.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/cast_static_lifetime.rs:5:19
    |
+LL |     let x = 22_u32;
+   |         - binding `x` declared here
 LL |     let y: &u32 = (&x) as &'static u32;
    |                   ^^^^----------------
    |                   |
diff --git a/tests/ui/nll/user-annotations/constant-in-expr-inherent-2.stderr b/tests/ui/nll/user-annotations/constant-in-expr-inherent-2.stderr
index 12065a85aa4..f164255ef30 100644
--- a/tests/ui/nll/user-annotations/constant-in-expr-inherent-2.stderr
+++ b/tests/ui/nll/user-annotations/constant-in-expr-inherent-2.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/constant-in-expr-inherent-2.rs:23:9
    |
+LL |     let x = ();
+   |         - binding `x` declared here
 LL |     FUN(&x);
    |     ----^^-
    |     |   |
@@ -13,6 +15,9 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/constant-in-expr-inherent-2.rs:24:23
    |
+LL |     let x = ();
+   |         - binding `x` declared here
+LL |     FUN(&x);
 LL |     A::ASSOCIATED_FUN(&x);
    |     ------------------^^-
    |     |                 |
@@ -25,6 +30,9 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/constant-in-expr-inherent-2.rs:25:28
    |
+LL |     let x = ();
+   |         - binding `x` declared here
+...
 LL |     B::ALSO_ASSOCIATED_FUN(&x);
    |     -----------------------^^-
    |     |                      |
@@ -37,6 +45,9 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/constant-in-expr-inherent-2.rs:26:31
    |
+LL |     let x = ();
+   |         - binding `x` declared here
+...
 LL |     <_>::TRAIT_ASSOCIATED_FUN(&x);
    |     --------------------------^^-
    |     |                         |
diff --git a/tests/ui/nll/user-annotations/fns.stderr b/tests/ui/nll/user-annotations/fns.stderr
index e0640da39e2..8b53e138d9b 100644
--- a/tests/ui/nll/user-annotations/fns.stderr
+++ b/tests/ui/nll/user-annotations/fns.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/fns.rs:23:29
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     some_fn::<&'static u32>(&c);
    |     ------------------------^^-
    |     |                       |
@@ -15,6 +17,7 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     some_fn::<&'a u32>(&c);
    |     -------------------^^-
    |     |                  |
diff --git a/tests/ui/nll/user-annotations/method-call.stderr b/tests/ui/nll/user-annotations/method-call.stderr
index 10447e45a6d..3803cbf776b 100644
--- a/tests/ui/nll/user-annotations/method-call.stderr
+++ b/tests/ui/nll/user-annotations/method-call.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/method-call.rs:36:34
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     a.method::<&'static u32>(b,  &c);
    |     -----------------------------^^-
    |     |                            |
@@ -15,6 +17,8 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 ...
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     a.method::<&'a u32>(b,  &c);
    |     ------------------------^^-
    |     |                       |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-1.stderr b/tests/ui/nll/user-annotations/method-ufcs-1.stderr
index 962ddfd2bd1..c7c08c948ab 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-1.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-1.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/method-ufcs-1.rs:30:7
    |
+LL |     let a = 22;
+   |         - binding `a` declared here
+...
 LL |     x(&a, b, c);
    |     --^^-------
    |     | |
@@ -14,6 +17,8 @@ error[E0597]: `a` does not live long enough
    |
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
+LL |     let a = 22;
+   |         - binding `a` declared here
 ...
 LL |     <&'a u32 as Bazoom<_>>::method(&a, b, c);
    |     -------------------------------^^-------
diff --git a/tests/ui/nll/user-annotations/method-ufcs-2.stderr b/tests/ui/nll/user-annotations/method-ufcs-2.stderr
index 63d59905e1c..b7861a3bd06 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-2.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-2.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/method-ufcs-2.rs:30:7
    |
+LL |     let a = 22;
+   |         - binding `a` declared here
+...
 LL |     x(&a, b, c);
    |     --^^-------
    |     | |
@@ -14,7 +17,10 @@ error[E0597]: `b` does not live long enough
    |
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
-...
+LL |     let a = 22;
+LL |     let b = 44;
+   |         - binding `b` declared here
+LL |     let c = 66;
 LL |     <_ as Bazoom<&'a u32>>::method(a, &b, c);
    |     ----------------------------------^^----
    |     |                                 |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-3.stderr b/tests/ui/nll/user-annotations/method-ufcs-3.stderr
index e7851833e93..8cb995a03ce 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-3.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-3.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/method-ufcs-3.rs:36:53
    |
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     <_ as Bazoom<_>>::method::<&'static u32>(&a, b, &c);
    |     ------------------------------------------------^^-
    |     |                                               |
@@ -15,6 +17,8 @@ error[E0597]: `c` does not live long enough
 LL | fn annot_reference_named_lifetime<'a>(_d: &'a u32) {
    |                                   -- lifetime `'a` defined here
 ...
+LL |     let c = 66;
+   |         - binding `c` declared here
 LL |     <_ as Bazoom<_>>::method::<&'a u32>(&a, b, &c);
    |     -------------------------------------------^^-
    |     |                                          |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-inherent-1.stderr b/tests/ui/nll/user-annotations/method-ufcs-inherent-1.stderr
index 94861babd6f..fb26b8d09e1 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-inherent-1.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-inherent-1.stderr
@@ -4,6 +4,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = A::<'a>::new(&v, 22);
    |             -------------^^-----
    |             |            |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-inherent-2.stderr b/tests/ui/nll/user-annotations/method-ufcs-inherent-2.stderr
index 06f20d9b235..03b97447e1a 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-inherent-2.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-inherent-2.stderr
@@ -4,6 +4,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = A::<'a>::new::<&'a u32>(&v, &v);
    |             ------------------------^^-----
    |             |                       |
@@ -19,6 +20,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = A::<'a>::new::<&'a u32>(&v, &v);
    |             ----------------------------^^-
    |             |                           |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-inherent-3.stderr b/tests/ui/nll/user-annotations/method-ufcs-inherent-3.stderr
index 4ad61dc81c4..69dd1d1aaae 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-inherent-3.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-inherent-3.stderr
@@ -4,6 +4,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = <A<'a>>::new(&v, 22);
    |             -------------^^-----
    |             |            |
diff --git a/tests/ui/nll/user-annotations/method-ufcs-inherent-4.stderr b/tests/ui/nll/user-annotations/method-ufcs-inherent-4.stderr
index 0f83e99cdfb..66d82bb49dc 100644
--- a/tests/ui/nll/user-annotations/method-ufcs-inherent-4.stderr
+++ b/tests/ui/nll/user-annotations/method-ufcs-inherent-4.stderr
@@ -4,6 +4,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = <A<'a>>::new::<&'a u32>(&v, &v);
    |             ------------------------^^-----
    |             |                       |
@@ -19,6 +20,7 @@ error[E0597]: `v` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let v = 22;
+   |         - binding `v` declared here
 LL |     let x = <A<'a>>::new::<&'a u32>(&v, &v);
    |             ----------------------------^^-
    |             |                           |
diff --git a/tests/ui/nll/user-annotations/normalization.stderr b/tests/ui/nll/user-annotations/normalization.stderr
index 975cb4b66d9..acc3a1800f4 100644
--- a/tests/ui/nll/user-annotations/normalization.stderr
+++ b/tests/ui/nll/user-annotations/normalization.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/normalization.rs:10:31
    |
+LL |     let a = 22;
+   |         - binding `a` declared here
 LL |     let _: <() as Foo>::Out = &a;
    |            ----------------   ^^ borrowed value does not live long enough
    |            |
@@ -12,6 +14,8 @@ LL | }
 error[E0597]: `a` does not live long enough
   --> $DIR/normalization.rs:13:40
    |
+LL |     let a = 22;
+   |         - binding `a` declared here
 LL |     let _: <&'static () as Foo>::Out = &a;
    |            -------------------------   ^^ borrowed value does not live long enough
    |            |
diff --git a/tests/ui/nll/user-annotations/pattern_substs_on_brace_enum_variant.stderr b/tests/ui/nll/user-annotations/pattern_substs_on_brace_enum_variant.stderr
index a97e7a9fd46..3e7969e1179 100644
--- a/tests/ui/nll/user-annotations/pattern_substs_on_brace_enum_variant.stderr
+++ b/tests/ui/nll/user-annotations/pattern_substs_on_brace_enum_variant.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_brace_enum_variant.rs:7:33
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo::Bar { field: &y };
    |                                 ^^ borrowed value does not live long enough
 LL |
@@ -12,6 +14,8 @@ LL | }
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_brace_enum_variant.rs:14:33
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo::Bar { field: &y };
    |                                 ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/user-annotations/pattern_substs_on_brace_struct.stderr b/tests/ui/nll/user-annotations/pattern_substs_on_brace_struct.stderr
index 408d7c2a5e2..89a1e9545e8 100644
--- a/tests/ui/nll/user-annotations/pattern_substs_on_brace_struct.stderr
+++ b/tests/ui/nll/user-annotations/pattern_substs_on_brace_struct.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_brace_struct.rs:5:28
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo { field: &y };
    |                            ^^ borrowed value does not live long enough
 LL |
@@ -12,6 +14,8 @@ LL | }
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_brace_struct.rs:12:28
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo { field: &y };
    |                            ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/user-annotations/pattern_substs_on_tuple_enum_variant.stderr b/tests/ui/nll/user-annotations/pattern_substs_on_tuple_enum_variant.stderr
index 920c906f63a..8efeecc7709 100644
--- a/tests/ui/nll/user-annotations/pattern_substs_on_tuple_enum_variant.stderr
+++ b/tests/ui/nll/user-annotations/pattern_substs_on_tuple_enum_variant.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_tuple_enum_variant.rs:7:24
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo::Bar(&y);
    |                        ^^ borrowed value does not live long enough
 LL |
@@ -12,6 +14,8 @@ LL | }
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_tuple_enum_variant.rs:14:24
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo::Bar(&y);
    |                        ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/user-annotations/pattern_substs_on_tuple_struct.stderr b/tests/ui/nll/user-annotations/pattern_substs_on_tuple_struct.stderr
index 3f01638d847..d7f1dac88a6 100644
--- a/tests/ui/nll/user-annotations/pattern_substs_on_tuple_struct.stderr
+++ b/tests/ui/nll/user-annotations/pattern_substs_on_tuple_struct.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_tuple_struct.rs:5:19
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo(&y);
    |                   ^^ borrowed value does not live long enough
 LL |
@@ -12,6 +14,8 @@ LL | }
 error[E0597]: `y` does not live long enough
   --> $DIR/pattern_substs_on_tuple_struct.rs:12:19
    |
+LL |     let y = 22;
+   |         - binding `y` declared here
 LL |     let foo = Foo(&y);
    |                   ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/nll/user-annotations/patterns.stderr b/tests/ui/nll/user-annotations/patterns.stderr
index de6f8f80fe2..8bb714f1d0c 100644
--- a/tests/ui/nll/user-annotations/patterns.stderr
+++ b/tests/ui/nll/user-annotations/patterns.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:6:9
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let y: &'static u32;
    |            ------------ type annotation requires that `x` is borrowed for `'static`
 LL |     y = &x;
@@ -11,6 +13,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:14:9
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let (y, z): (&'static u32, &'static u32);
    |                 ---------------------------- type annotation requires that `x` is borrowed for `'static`
 LL |     y = &x;
@@ -21,6 +25,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:20:13
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let y = &x;
    |             ^^ borrowed value does not live long enough
 LL |     let ref z: &'static u32 = y;
@@ -32,6 +38,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:39:9
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let Single { value: y }: Single<&'static u32>;
    |                              -------------------- type annotation requires that `x` is borrowed for `'static`
 LL |     y = &x;
@@ -42,6 +50,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:51:10
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let Single2 { value: mut _y }: Single2<StaticU32>;
    |                                    ------------------ type annotation requires that `x` is borrowed for `'static`
 LL |     _y = &x;
@@ -52,6 +62,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:56:27
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let y: &'static u32 = &x;
    |            ------------   ^^ borrowed value does not live long enough
    |            |
@@ -62,6 +74,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:61:27
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let _: &'static u32 = &x;
    |            ------------   ^^ borrowed value does not live long enough
    |            |
@@ -100,6 +114,8 @@ LL |     let (_a, b): (Vec<&'static String>, _) = (vec![&String::new()], 44);
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:75:40
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let (_, _): (&'static u32, u32) = (&x, 44);
    |                 -------------------    ^^ borrowed value does not live long enough
    |                 |
@@ -110,6 +126,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:80:40
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let (y, _): (&'static u32, u32) = (&x, 44);
    |                 -------------------    ^^ borrowed value does not live long enough
    |                 |
@@ -120,6 +138,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:85:69
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let Single { value: y }: Single<&'static u32> = Single { value: &x };
    |                              --------------------                   ^^ borrowed value does not live long enough
    |                              |
@@ -130,6 +150,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:90:69
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let Single { value: _ }: Single<&'static u32> = Single { value: &x };
    |                              --------------------                   ^^ borrowed value does not live long enough
    |                              |
@@ -140,6 +162,8 @@ LL | }
 error[E0597]: `x` does not live long enough
   --> $DIR/patterns.rs:98:17
    |
+LL |     let x = 22;
+   |         - binding `x` declared here
 LL |     let Double { value1: _, value2: _ }: Double<&'static u32> = Double {
    |                                          -------------------- type annotation requires that `x` is borrowed for `'static`
 LL |         value1: &x,
diff --git a/tests/ui/nll/user-annotations/promoted-annotation.stderr b/tests/ui/nll/user-annotations/promoted-annotation.stderr
index cb99a6a369d..132a00ba415 100644
--- a/tests/ui/nll/user-annotations/promoted-annotation.stderr
+++ b/tests/ui/nll/user-annotations/promoted-annotation.stderr
@@ -4,6 +4,7 @@ error[E0597]: `x` does not live long enough
 LL | fn foo<'a>() {
    |        -- lifetime `'a` defined here
 LL |     let x = 0;
+   |         - binding `x` declared here
 LL |     let f = &drop::<&'a i32>;
    |             ---------------- assignment requires that `x` is borrowed for `'a`
 LL |     f(&x);
diff --git a/tests/ui/nll/user-annotations/type_ascription_static_lifetime.stderr b/tests/ui/nll/user-annotations/type_ascription_static_lifetime.stderr
index ccbf3c1d927..766877f8835 100644
--- a/tests/ui/nll/user-annotations/type_ascription_static_lifetime.stderr
+++ b/tests/ui/nll/user-annotations/type_ascription_static_lifetime.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/type_ascription_static_lifetime.rs:6:33
    |
+LL |     let x = 22_u32;
+   |         - binding `x` declared here
 LL |     let y: &u32 = type_ascribe!(&x, &'static u32);
    |                   --------------^^---------------
    |                   |             |
diff --git a/tests/ui/parser/anon-enums.rs b/tests/ui/parser/anon-enums.rs
new file mode 100644
index 00000000000..56b8a3d43be
--- /dev/null
+++ b/tests/ui/parser/anon-enums.rs
@@ -0,0 +1,17 @@
+fn foo(x: bool | i32) -> i32 | f64 {
+//~^ ERROR anonymous enums are not supported
+//~| ERROR anonymous enums are not supported
+    match x {
+        x: i32 => x, //~ ERROR expected
+        true => 42.,
+        false => 0.333,
+    }
+}
+
+fn main() {
+    match foo(true) {
+        42: i32 => (), //~ ERROR expected
+        _: f64 => (), //~ ERROR expected
+        x: i32 => (), //~ ERROR expected
+    }
+}
diff --git a/tests/ui/parser/anon-enums.stderr b/tests/ui/parser/anon-enums.stderr
new file mode 100644
index 00000000000..84158225660
--- /dev/null
+++ b/tests/ui/parser/anon-enums.stderr
@@ -0,0 +1,68 @@
+error: anonymous enums are not supported
+  --> $DIR/anon-enums.rs:1:16
+   |
+LL | fn foo(x: bool | i32) -> i32 | f64 {
+   |           ---- ^ ---
+   |
+   = help: create a named `enum` and use it here instead:
+           enum Name {
+               Variant1(bool),
+               Variant2(i32),
+           }
+
+error: anonymous enums are not supported
+  --> $DIR/anon-enums.rs:1:30
+   |
+LL | fn foo(x: bool | i32) -> i32 | f64 {
+   |                          --- ^ ---
+   |
+   = help: create a named `enum` and use it here instead:
+           enum Name {
+               Variant1(i32),
+               Variant2(f64),
+           }
+
+error: expected one of `@` or `|`, found `:`
+  --> $DIR/anon-enums.rs:5:10
+   |
+LL |         x: i32 => x,
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected one of `@` or `|`
+   |
+help: maybe write a path separator here
+   |
+LL |         x::i32 => x,
+   |          ~~
+
+error: expected one of `...`, `..=`, `..`, or `|`, found `:`
+  --> $DIR/anon-enums.rs:13:11
+   |
+LL |         42: i32 => (),
+   |           ^ --- specifying the type of a pattern isn't supported
+   |           |
+   |           expected one of `...`, `..=`, `..`, or `|`
+
+error: expected `|`, found `:`
+  --> $DIR/anon-enums.rs:14:10
+   |
+LL |         _: f64 => (),
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected `|`
+
+error: expected one of `@` or `|`, found `:`
+  --> $DIR/anon-enums.rs:15:10
+   |
+LL |         x: i32 => (),
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected one of `@` or `|`
+   |
+help: maybe write a path separator here
+   |
+LL |         x::i32 => (),
+   |          ~~
+
+error: aborting due to 6 previous errors
+
diff --git a/tests/ui/parser/bastion-of-the-turbofish.rs b/tests/ui/parser/bastion-of-the-turbofish.rs
index e12857008a5..7ceea676d3a 100644
--- a/tests/ui/parser/bastion-of-the-turbofish.rs
+++ b/tests/ui/parser/bastion-of-the-turbofish.rs
@@ -34,7 +34,7 @@
 
 // See https://github.com/rust-lang/rust/pull/53562
 // and https://github.com/rust-lang/rfcs/pull/2527
-// and https://twitter.com/garblefart/status/1393236602856611843
+// and https://web.archive.org/web/20211010063452/https://twitter.com/garblefart/status/1393236602856611843
 // for context.
 
 fn main() {
diff --git a/tests/ui/parser/deli-ident-issue-1.rs b/tests/ui/parser/deli-ident-issue-1.rs
new file mode 100644
index 00000000000..54485262a0c
--- /dev/null
+++ b/tests/ui/parser/deli-ident-issue-1.rs
@@ -0,0 +1,24 @@
+#![feature(let_chains)]
+trait Demo {}
+
+impl dyn Demo {
+    pub fn report(&self) -> u32 {
+        let sum = |a: u32,
+                   b: u32,
+                   c: u32| {
+            a + b + c
+        };
+        sum(1, 2, 3)
+    }
+
+    fn check(&self, val: Option<u32>, num: Option<u32>) {
+        if let Some(b) = val
+        && let Some(c) = num {
+        && b == c {
+            //~^ ERROR expected struct
+            //~| ERROR mismatched types
+        }
+    }
+}
+
+fn main() { } //~ ERROR this file contains an unclosed delimiter
diff --git a/tests/ui/parser/deli-ident-issue-1.stderr b/tests/ui/parser/deli-ident-issue-1.stderr
new file mode 100644
index 00000000000..1119edb199f
--- /dev/null
+++ b/tests/ui/parser/deli-ident-issue-1.stderr
@@ -0,0 +1,37 @@
+error: this file contains an unclosed delimiter
+  --> $DIR/deli-ident-issue-1.rs:24:66
+   |
+LL | impl dyn Demo {
+   |               - unclosed delimiter
+...
+LL |         && let Some(c) = num {
+   |                              - this delimiter might not be properly closed...
+...
+LL |     }
+   |     - ...as it matches this but it has different indentation
+...
+LL | fn main() { }
+   |                                                                  ^
+
+error[E0574]: expected struct, variant or union type, found local variable `c`
+  --> $DIR/deli-ident-issue-1.rs:17:17
+   |
+LL |         && b == c {
+   |                 ^ not a struct, variant or union type
+
+error[E0308]: mismatched types
+  --> $DIR/deli-ident-issue-1.rs:17:9
+   |
+LL |       fn check(&self, val: Option<u32>, num: Option<u32>) {
+   |                                                           - expected `()` because of default return type
+...
+LL | /         && b == c {
+LL | |
+LL | |
+LL | |         }
+   | |_________^ expected `()`, found `bool`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0308, E0574.
+For more information about an error, try `rustc --explain E0308`.
diff --git a/tests/ui/parser/deli-ident-issue-2.rs b/tests/ui/parser/deli-ident-issue-2.rs
new file mode 100644
index 00000000000..5394760df70
--- /dev/null
+++ b/tests/ui/parser/deli-ident-issue-2.rs
@@ -0,0 +1,7 @@
+fn main() {
+    if 1 < 2 {
+        let _a = vec!]; //~ ERROR mismatched closing delimiter
+    }
+} //~ ERROR unexpected closing delimiter
+
+fn main() {}
diff --git a/tests/ui/parser/deli-ident-issue-2.stderr b/tests/ui/parser/deli-ident-issue-2.stderr
new file mode 100644
index 00000000000..c8f59c9d32b
--- /dev/null
+++ b/tests/ui/parser/deli-ident-issue-2.stderr
@@ -0,0 +1,19 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/deli-ident-issue-2.rs:5:1
+   |
+LL |         let _a = vec!];
+   |                      - missing open `[` for this delimiter
+LL |     }
+LL | }
+   | ^ unexpected closing delimiter
+
+error: mismatched closing delimiter: `]`
+  --> $DIR/deli-ident-issue-2.rs:2:14
+   |
+LL |     if 1 < 2 {
+   |              ^ unclosed delimiter
+LL |         let _a = vec!];
+   |                      ^ mismatched closing delimiter
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/parser/fake-anon-enums-in-macros.rs b/tests/ui/parser/fake-anon-enums-in-macros.rs
new file mode 100644
index 00000000000..38fe8dee238
--- /dev/null
+++ b/tests/ui/parser/fake-anon-enums-in-macros.rs
@@ -0,0 +1,20 @@
+// build-pass
+macro_rules! check_ty {
+    ($Z:ty) => { compile_error!("triggered"); };
+    ($X:ty | $Y:ty) => { $X };
+}
+
+macro_rules! check {
+    ($Z:ty) => { compile_error!("triggered"); };
+    ($X:ty | $Y:ty) => { };
+}
+
+check! { i32 | u8 }
+
+fn foo(x: check_ty! { i32 | u8 }) -> check_ty! { i32 | u8 } {
+    x
+}
+fn main() {
+    let x: check_ty! { i32 | u8 } = 42;
+    let _: check_ty! { i32 | u8 } = foo(x);
+}
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-1.rs b/tests/ui/parser/issue-68987-unmatch-issue-1.rs
new file mode 100644
index 00000000000..30e7ef46736
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-1.rs
@@ -0,0 +1,12 @@
+// This file has unexpected closing delimiter,
+
+fn func(o: Option<u32>) {
+    match o {
+        Some(_x) => {}   // Extra '}'
+            let _ = if true {};
+        }
+        None => {}
+    }
+} //~ ERROR unexpected closing delimiter
+
+fn main() {}
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-1.stderr b/tests/ui/parser/issue-68987-unmatch-issue-1.stderr
new file mode 100644
index 00000000000..2d873b46193
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-1.stderr
@@ -0,0 +1,16 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/issue-68987-unmatch-issue-1.rs:10:1
+   |
+LL |     match o {
+   |             - this delimiter might not be properly closed...
+LL |         Some(_x) => {}   // Extra '}'
+   |                     -- block is empty, you might have not meant to close it
+LL |             let _ = if true {};
+LL |         }
+   |         - ...as it matches this but it has different indentation
+...
+LL | }
+   | ^ unexpected closing delimiter
+
+error: aborting due to previous error
+
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-2.rs b/tests/ui/parser/issue-68987-unmatch-issue-2.rs
new file mode 100644
index 00000000000..89aaa68ba40
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-2.rs
@@ -0,0 +1,14 @@
+// FIXME: this case need more work to fix
+// currently the TokenTree matching ')' with '{', which is not user friendly for diagnostics
+async fn obstest() -> Result<> {
+    let obs_connect = || -> Result<(), MyError) { //~ ERROR mismatched closing delimiter
+        async {
+        }
+    }
+
+    if let Ok(version, scene_list) = obs_connect() {
+
+    } else {
+
+    }
+} //~ ERROR unexpected closing delimiter
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-2.stderr b/tests/ui/parser/issue-68987-unmatch-issue-2.stderr
new file mode 100644
index 00000000000..2c08d41a15f
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-2.stderr
@@ -0,0 +1,19 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/issue-68987-unmatch-issue-2.rs:14:1
+   |
+LL |     let obs_connect = || -> Result<(), MyError) {
+   |                                               - missing open `(` for this delimiter
+...
+LL | }
+   | ^ unexpected closing delimiter
+
+error: mismatched closing delimiter: `)`
+  --> $DIR/issue-68987-unmatch-issue-2.rs:3:32
+   |
+LL | async fn obstest() -> Result<> {
+   |                                ^ unclosed delimiter
+LL |     let obs_connect = || -> Result<(), MyError) {
+   |                                               ^ mismatched closing delimiter
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-3.rs b/tests/ui/parser/issue-68987-unmatch-issue-3.rs
new file mode 100644
index 00000000000..e98df8d7c3c
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-3.rs
@@ -0,0 +1,8 @@
+// the `{` is closed with `)`, there is a missing `(`
+fn f(i: u32, j: u32) {
+    let res = String::new();
+    let mut cnt = i;
+    while cnt < j {
+        write!&mut res, " "); //~ ERROR mismatched closing delimiter
+    }
+} //~ ERROR unexpected closing delimiter
diff --git a/tests/ui/parser/issue-68987-unmatch-issue-3.stderr b/tests/ui/parser/issue-68987-unmatch-issue-3.stderr
new file mode 100644
index 00000000000..a3fc46a1e88
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue-3.stderr
@@ -0,0 +1,19 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/issue-68987-unmatch-issue-3.rs:8:1
+   |
+LL |         write!&mut res, " ");
+   |                            - missing open `(` for this delimiter
+LL |     }
+LL | }
+   | ^ unexpected closing delimiter
+
+error: mismatched closing delimiter: `)`
+  --> $DIR/issue-68987-unmatch-issue-3.rs:5:19
+   |
+LL |     while cnt < j {
+   |                   ^ unclosed delimiter
+LL |         write!&mut res, " ");
+   |                            ^ mismatched closing delimiter
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/parser/issue-68987-unmatch-issue.rs b/tests/ui/parser/issue-68987-unmatch-issue.rs
new file mode 100644
index 00000000000..5a3620bf24b
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue.rs
@@ -0,0 +1,12 @@
+// This file has unexpected closing delimiter,
+
+fn func(o: Option<u32>) {
+    match o {
+        Some(_x) =>   // Missing '{'
+            let _ = if true {};
+        }
+        None => {}
+    }
+} //~ ERROR unexpected closing delimiter
+
+fn main() {}
diff --git a/tests/ui/parser/issue-68987-unmatch-issue.stderr b/tests/ui/parser/issue-68987-unmatch-issue.stderr
new file mode 100644
index 00000000000..cabd133242f
--- /dev/null
+++ b/tests/ui/parser/issue-68987-unmatch-issue.stderr
@@ -0,0 +1,16 @@
+error: unexpected closing delimiter: `}`
+  --> $DIR/issue-68987-unmatch-issue.rs:10:1
+   |
+LL |     match o {
+   |             - this delimiter might not be properly closed...
+LL |         Some(_x) =>   // Missing '{'
+LL |             let _ = if true {};
+   |                             -- block is empty, you might have not meant to close it
+LL |         }
+   |         - ...as it matches this but it has different indentation
+...
+LL | }
+   | ^ unexpected closing delimiter
+
+error: aborting due to previous error
+
diff --git a/tests/ui/parser/issue-81827.stderr b/tests/ui/parser/issue-81827.stderr
index 069de339194..867244b72e8 100644
--- a/tests/ui/parser/issue-81827.stderr
+++ b/tests/ui/parser/issue-81827.stderr
@@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-81827.rs:11:27
    |
 LL | fn r()->i{0|{#[cfg(r(0{]0
-   |          -  -             ^
-   |          |  |
+   |          -  -          -  ^
+   |          |  |          |
+   |          |  |          missing open `[` for this delimiter
    |          |  unclosed delimiter
    |          unclosed delimiter
 
@@ -11,8 +12,9 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-81827.rs:11:27
    |
 LL | fn r()->i{0|{#[cfg(r(0{]0
-   |          -  -             ^
-   |          |  |
+   |          -  -          -  ^
+   |          |  |          |
+   |          |  |          missing open `[` for this delimiter
    |          |  unclosed delimiter
    |          unclosed delimiter
 
diff --git a/tests/ui/parser/issues/issue-44406.stderr b/tests/ui/parser/issues/issue-44406.stderr
index 1f0c1ea4c2f..de02ea85b27 100644
--- a/tests/ui/parser/issues/issue-44406.stderr
+++ b/tests/ui/parser/issues/issue-44406.stderr
@@ -21,8 +21,8 @@ LL |     foo!(true);
    = note: this error originates in the macro `foo` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: if `bar` is a struct, use braces as delimiters
    |
-LL |         bar {  }
-   |             ~
+LL |         bar { baz: $rest }
+   |             ~            ~
 help: if `bar` is a function, use the arguments directly
    |
 LL -         bar(baz: $rest)
diff --git a/tests/ui/parser/issues/issue-62973.stderr b/tests/ui/parser/issues/issue-62973.stderr
index 4737bc71860..3cb6d75a675 100644
--- a/tests/ui/parser/issues/issue-62973.stderr
+++ b/tests/ui/parser/issues/issue-62973.stderr
@@ -2,8 +2,10 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-62973.rs:8:2
    |
 LL | fn p() { match s { v, E { [) {) }
-   |        -         - unclosed delimiter
-   |        |
+   |        -         -         -  - missing open `(` for this delimiter
+   |        |         |         |
+   |        |         |         missing open `(` for this delimiter
+   |        |         unclosed delimiter
    |        unclosed delimiter
 LL |
 LL |
@@ -13,8 +15,10 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-62973.rs:8:2
    |
 LL | fn p() { match s { v, E { [) {) }
-   |        -         - unclosed delimiter
-   |        |
+   |        -         -         -  - missing open `(` for this delimiter
+   |        |         |         |
+   |        |         |         missing open `(` for this delimiter
+   |        |         unclosed delimiter
    |        unclosed delimiter
 LL |
 LL |
diff --git a/tests/ui/parser/issues/issue-63116.stderr b/tests/ui/parser/issues/issue-63116.stderr
index cfdd99d1434..a1f8a77ffa7 100644
--- a/tests/ui/parser/issues/issue-63116.stderr
+++ b/tests/ui/parser/issues/issue-63116.stderr
@@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-63116.rs:3:18
    |
 LL | impl W <s(f;Y(;]
-   |          -       ^
-   |          |
+   |          -     - ^
+   |          |     |
+   |          |     missing open `[` for this delimiter
    |          unclosed delimiter
 
 error: expected one of `!`, `(`, `)`, `+`, `,`, `::`, or `<`, found `;`
diff --git a/tests/ui/parser/issues/issue-69259.rs b/tests/ui/parser/issues/issue-69259.rs
new file mode 100644
index 00000000000..01fc2c08546
--- /dev/null
+++ b/tests/ui/parser/issues/issue-69259.rs
@@ -0,0 +1,3 @@
+fn main() {}
+
+fn f) {} //~ ERROR unexpected closing delimiter
diff --git a/tests/ui/parser/issues/issue-69259.stderr b/tests/ui/parser/issues/issue-69259.stderr
new file mode 100644
index 00000000000..604b7de3319
--- /dev/null
+++ b/tests/ui/parser/issues/issue-69259.stderr
@@ -0,0 +1,8 @@
+error: unexpected closing delimiter: `)`
+  --> $DIR/issue-69259.rs:3:5
+   |
+LL | fn f) {}
+   |     ^ unexpected closing delimiter
+
+error: aborting due to previous error
+
diff --git a/tests/ui/parser/issues/issue-70583-block-is-empty-1.stderr b/tests/ui/parser/issues/issue-70583-block-is-empty-1.stderr
index 39bf113ef83..46cbb056d1d 100644
--- a/tests/ui/parser/issues/issue-70583-block-is-empty-1.stderr
+++ b/tests/ui/parser/issues/issue-70583-block-is-empty-1.stderr
@@ -2,10 +2,10 @@ error: unexpected closing delimiter: `}`
   --> $DIR/issue-70583-block-is-empty-1.rs:20:1
    |
 LL | fn struct_generic(x: Vec<i32>) {
-   |                                - this opening brace...
+   |                                - this delimiter might not be properly closed...
 ...
 LL |     }
-   |     - ...matches this closing brace
+   |     - ...as it matches this but it has different indentation
 LL | }
    | ^ unexpected closing delimiter
 
diff --git a/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr b/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
index 5d37b216427..9ae94c70186 100644
--- a/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
+++ b/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
@@ -1,8 +1,12 @@
 error: unexpected closing delimiter: `}`
   --> $DIR/issue-70583-block-is-empty-2.rs:14:1
    |
+LL |         match self {
+   |                    - this delimiter might not be properly closed...
 LL |             ErrorHandled::Reported => {}}
-   |                                       -- block is empty, you might have not meant to close it
+   |                                       --- ...as it matches this but it has different indentation
+   |                                       |
+   |                                       block is empty, you might have not meant to close it
 ...
 LL | }
    | ^ unexpected closing delimiter
diff --git a/tests/ui/parser/issues/issue-87086-colon-path-sep.rs b/tests/ui/parser/issues/issue-87086-colon-path-sep.rs
index 0b7b67496d6..e1ea38f2795 100644
--- a/tests/ui/parser/issues/issue-87086-colon-path-sep.rs
+++ b/tests/ui/parser/issues/issue-87086-colon-path-sep.rs
@@ -68,7 +68,6 @@ fn main() {
         Foo:Bar::Baz => {}
         //~^ ERROR: expected one of
         //~| HELP: maybe write a path separator here
-        //~| ERROR: failed to resolve: `Bar` is a variant, not a module
     }
     match myfoo {
         Foo::Bar => {}
diff --git a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
index 2050a16beb3..63b072ac4cd 100644
--- a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
+++ b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
@@ -2,89 +2,118 @@ error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:17:12
    |
 LL |         Foo:Bar => {}
-   |            ^
+   |            ^--- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar => {}
+   |            ~~
 
 error: expected one of `!`, `(`, `...`, `..=`, `..`, `::`, `{`, or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:23:17
    |
 LL |         qux::Foo:Bar => {}
-   |                 ^
+   |                 ^--- specifying the type of a pattern isn't supported
    |                 |
    |                 expected one of 8 possible tokens
-   |                 help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Bar => {}
+   |                 ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:29:12
    |
 LL |         qux:Foo::Baz => {}
-   |            ^
+   |            ^-------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Baz => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:35:12
    |
 LL |         qux: Foo::Baz if true => {}
-   |            ^
+   |            ^ -------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Baz if true => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:40:15
    |
 LL |     if let Foo:Bar = f() {
-   |               ^
+   |               ^--- specifying the type of a pattern isn't supported
    |               |
    |               expected one of `@` or `|`
-   |               help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |     if let Foo::Bar = f() {
+   |               ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:48:16
    |
 LL |         ref qux: Foo::Baz => {}
-   |                ^
+   |                ^ -------- specifying the type of a pattern isn't supported
    |                |
    |                expected one of `@` or `|`
-   |                help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         ref qux::Foo::Baz => {}
+   |                ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:57:16
    |
 LL |         mut qux: Foo::Baz => {}
-   |                ^
+   |                ^ -------- specifying the type of a pattern isn't supported
    |                |
    |                expected one of `@` or `|`
-   |                help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         mut qux::Foo::Baz => {}
+   |                ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:68:12
    |
 LL |         Foo:Bar::Baz => {}
-   |            ^
+   |            ^-------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar::Baz => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
-  --> $DIR/issue-87086-colon-path-sep.rs:75:12
+  --> $DIR/issue-87086-colon-path-sep.rs:74:12
    |
 LL |         Foo:Bar => {}
-   |            ^
+   |            ^--- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
-
-error[E0433]: failed to resolve: `Bar` is a variant, not a module
-  --> $DIR/issue-87086-colon-path-sep.rs:68:13
    |
-LL |         Foo:Bar::Baz => {}
-   |             ^^^ `Bar` is a variant, not a module
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar => {}
+   |            ~~
 
-error: aborting due to 10 previous errors
+error: aborting due to 9 previous errors
 
-For more information about this error, try `rustc --explain E0433`.
diff --git a/tests/ui/parser/macro-mismatched-delim-paren-brace.stderr b/tests/ui/parser/macro-mismatched-delim-paren-brace.stderr
index 967a3e6fdc1..689ce1eb6b7 100644
--- a/tests/ui/parser/macro-mismatched-delim-paren-brace.stderr
+++ b/tests/ui/parser/macro-mismatched-delim-paren-brace.stderr
@@ -2,10 +2,10 @@ error: unexpected closing delimiter: `}`
   --> $DIR/macro-mismatched-delim-paren-brace.rs:5:1
    |
 LL | fn main() {
-   |           - this opening brace...
+   |           - this delimiter might not be properly closed...
 ...
 LL |     }
-   |     - ...matches this closing brace
+   |     - ...as it matches this but it has different indentation
 LL | }
    | ^ unexpected closing delimiter
 
diff --git a/tests/ui/parser/trait-object-delimiters.rs b/tests/ui/parser/trait-object-delimiters.rs
index cc04ac05204..c41cda18743 100644
--- a/tests/ui/parser/trait-object-delimiters.rs
+++ b/tests/ui/parser/trait-object-delimiters.rs
@@ -5,6 +5,8 @@ fn foo1(_: &dyn Drop + AsRef<str>) {} //~ ERROR ambiguous `+` in a type
 
 fn foo2(_: &dyn (Drop + AsRef<str>)) {} //~ ERROR incorrect braces around trait bounds
 
+fn foo2_no_space(_: &dyn(Drop + AsRef<str>)) {} //~ ERROR incorrect braces around trait bounds
+
 fn foo3(_: &dyn {Drop + AsRef<str>}) {} //~ ERROR expected parameter name, found `{`
 //~^ ERROR expected one of `!`, `(`, `)`, `*`, `,`, `?`, `for`, `~`, lifetime, or path, found `{`
 //~| ERROR at least one trait is required for an object type
diff --git a/tests/ui/parser/trait-object-delimiters.stderr b/tests/ui/parser/trait-object-delimiters.stderr
index 99c4515459d..ccce3a8053e 100644
--- a/tests/ui/parser/trait-object-delimiters.stderr
+++ b/tests/ui/parser/trait-object-delimiters.stderr
@@ -13,17 +13,29 @@ LL | fn foo2(_: &dyn (Drop + AsRef<str>)) {}
 help: remove the parentheses
    |
 LL - fn foo2(_: &dyn (Drop + AsRef<str>)) {}
-LL + fn foo2(_: &dyn Drop + AsRef<str>) {}
+LL + fn foo2(_: &dyn  Drop + AsRef<str>) {}
+   |
+
+error: incorrect braces around trait bounds
+  --> $DIR/trait-object-delimiters.rs:8:25
+   |
+LL | fn foo2_no_space(_: &dyn(Drop + AsRef<str>)) {}
+   |                         ^                 ^
+   |
+help: remove the parentheses
+   |
+LL - fn foo2_no_space(_: &dyn(Drop + AsRef<str>)) {}
+LL + fn foo2_no_space(_: &dyn Drop + AsRef<str>) {}
    |
 
 error: expected parameter name, found `{`
-  --> $DIR/trait-object-delimiters.rs:8:17
+  --> $DIR/trait-object-delimiters.rs:10:17
    |
 LL | fn foo3(_: &dyn {Drop + AsRef<str>}) {}
    |                 ^ expected parameter name
 
 error: expected one of `!`, `(`, `)`, `*`, `,`, `?`, `for`, `~`, lifetime, or path, found `{`
-  --> $DIR/trait-object-delimiters.rs:8:17
+  --> $DIR/trait-object-delimiters.rs:10:17
    |
 LL | fn foo3(_: &dyn {Drop + AsRef<str>}) {}
    |                -^ expected one of 10 possible tokens
@@ -31,13 +43,13 @@ LL | fn foo3(_: &dyn {Drop + AsRef<str>}) {}
    |                help: missing `,`
 
 error: expected identifier, found `<`
-  --> $DIR/trait-object-delimiters.rs:12:17
+  --> $DIR/trait-object-delimiters.rs:14:17
    |
 LL | fn foo4(_: &dyn <Drop + AsRef<str>>) {}
    |                 ^ expected identifier
 
 error: invalid `dyn` keyword
-  --> $DIR/trait-object-delimiters.rs:14:25
+  --> $DIR/trait-object-delimiters.rs:16:25
    |
 LL | fn foo5(_: &(dyn Drop + dyn AsRef<str>)) {}
    |                         ^^^ help: remove this keyword
@@ -56,13 +68,13 @@ LL | fn foo1(_: &dyn Drop + AsRef<str>) {}
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0224]: at least one trait is required for an object type
-  --> $DIR/trait-object-delimiters.rs:8:13
+  --> $DIR/trait-object-delimiters.rs:10:13
    |
 LL | fn foo3(_: &dyn {Drop + AsRef<str>}) {}
    |             ^^^
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
-  --> $DIR/trait-object-delimiters.rs:14:29
+  --> $DIR/trait-object-delimiters.rs:16:29
    |
 LL | fn foo5(_: &(dyn Drop + dyn AsRef<str>)) {}
    |                  ----       ^^^^^^^^^^ additional non-auto trait
@@ -72,7 +84,7 @@ LL | fn foo5(_: &(dyn Drop + dyn AsRef<str>)) {}
    = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Drop + AsRef<str> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
-error: aborting due to 9 previous errors
+error: aborting due to 10 previous errors
 
 Some errors have detailed explanations: E0224, E0225.
 For more information about an error, try `rustc --explain E0224`.
diff --git a/tests/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr b/tests/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
index c8b45fd24d9..29cd6c45c34 100644
--- a/tests/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
+++ b/tests/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
@@ -4,8 +4,8 @@ error: cannot move out of value because it is borrowed
 LL |         Some(ref _y @ _z) => {}
    |              ------^^^--
    |              |        |
-   |              |        value moved into `_z` here
-   |              value borrowed, by `_y`, here
+   |              |        value is moved into `_z` here
+   |              value is borrowed by `_y` here
 
 error: borrow of moved value
   --> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:19:14
@@ -28,8 +28,8 @@ error: cannot move out of value because it is borrowed
 LL |         Some(ref mut _y @ _z) => {}
    |              ----------^^^--
    |              |            |
-   |              |            value moved into `_z` here
-   |              value borrowed, by `_y`, here
+   |              |            value is moved into `_z` here
+   |              value is mutably borrowed by `_y` here
 
 error: borrow of moved value
   --> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:33:14
diff --git a/tests/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr b/tests/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
index f27df32ccfa..2c123b01e17 100644
--- a/tests/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
+++ b/tests/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
@@ -4,8 +4,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ box b = Box::new(NC);
    |         -----^^^^^^^-
    |         |           |
-   |         |           value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |           value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-at-and-box.rs:34:9
@@ -13,8 +13,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ box ref mut b = Box::new(nc());
    |         -----^^^^^^^---------
    |         |           |
-   |         |           mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-at-and-box.rs:36:9
@@ -22,8 +22,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
    |         |           |
-   |         |           mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-at-and-box.rs:38:9
@@ -31,8 +31,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
    |         |           |
-   |         |           mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-at-and-box.rs:42:9
@@ -40,8 +40,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
    |         |           |
-   |         |           mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-at-and-box.rs:48:9
@@ -49,8 +49,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ box ref b = Box::new(NC);
    |         ---------^^^^^^^-----
    |         |               |
-   |         |               immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |               value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-at-and-box.rs:62:9
@@ -58,8 +58,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ box ref b => {
    |         ---------^^^^^^^-----
    |         |               |
-   |         |               immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |               value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-at-and-box.rs:54:11
@@ -67,8 +67,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     fn f5(ref mut a @ box ref b: Box<NC>) {
    |           ---------^^^^^^^-----
    |           |               |
-   |           |               immutable borrow, by `b`, occurs here
-   |           mutable borrow, by `a`, occurs here
+   |           |               value is borrowed by `b` here
+   |           value is mutably borrowed by `a` here
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-at-and-box.rs:31:9
diff --git a/tests/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr b/tests/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
index 770bb89530c..4f7fbc9e04b 100644
--- a/tests/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
+++ b/tests/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
@@ -4,8 +4,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ b = U;
    |         -----^^^-
    |         |       |
-   |         |       value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |       value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:26:9
@@ -13,9 +13,9 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (U, U);
    |         -----^^^^^^^^^^^^-----^^^^^^^^^^-^
    |         |                |              |
-   |         |                |              value moved into `e` here
-   |         |                value moved into `c` here
-   |         value borrowed, by `a`, here
+   |         |                |              value is moved into `e` here
+   |         |                value is moved into `c` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:26:18
@@ -23,8 +23,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (U, U);
    |                  -----^^^-----
    |                  |       |
-   |                  |       value moved into `c` here
-   |                  value borrowed, by `b`, here
+   |                  |       value is moved into `c` here
+   |                  value is borrowed by `b` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:26:33
@@ -32,8 +32,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (U, U);
    |                                 -----^^^-
    |                                 |       |
-   |                                 |       value moved into `e` here
-   |                                 value borrowed, by `d`, here
+   |                                 |       value is moved into `e` here
+   |                                 value is borrowed by `d` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:30:9
@@ -41,9 +41,9 @@ error: cannot move out of value because it is borrowed
 LL |     let ref mut a @ [b, mut c] = [U, U];
    |         ---------^^^^-^^-----^
    |         |            |  |
-   |         |            |  value moved into `c` here
-   |         |            value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |            |  value is moved into `c` here
+   |         |            value is moved into `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:33:9
@@ -51,8 +51,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ b = u();
    |         -----^^^-
    |         |       |
-   |         |       value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |       value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:36:9
@@ -60,9 +60,9 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (u(), u());
    |         -----^^^^^^^^^^^^-----^^^^^^^^^^-^
    |         |                |              |
-   |         |                |              value moved into `e` here
-   |         |                value moved into `c` here
-   |         value borrowed, by `a`, here
+   |         |                |              value is moved into `e` here
+   |         |                value is moved into `c` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:36:18
@@ -70,8 +70,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (u(), u());
    |                  -----^^^-----
    |                  |       |
-   |                  |       value moved into `c` here
-   |                  value borrowed, by `b`, here
+   |                  |       value is moved into `c` here
+   |                  value is borrowed by `b` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:36:33
@@ -79,8 +79,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ (ref b @ mut c, ref d @ e) = (u(), u());
    |                                 -----^^^-
    |                                 |       |
-   |                                 |       value moved into `e` here
-   |                                 value borrowed, by `d`, here
+   |                                 |       value is moved into `e` here
+   |                                 value is borrowed by `d` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:42:9
@@ -88,9 +88,9 @@ error: cannot move out of value because it is borrowed
 LL |     let ref mut a @ [b, mut c] = [u(), u()];
    |         ---------^^^^-^^-----^
    |         |            |  |
-   |         |            |  value moved into `c` here
-   |         |            value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |            |  value is moved into `c` here
+   |         |            value is moved into `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:47:9
@@ -98,8 +98,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some(b) => {}
    |         -----^^^^^^^^-^
    |         |            |
-   |         |            value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |            value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:52:9
@@ -107,9 +107,9 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |         -----^^^^^^^^^^^^^^^^^-----^^^^^^^^^^-^^
    |         |                     |              |
-   |         |                     |              value moved into `e` here
-   |         |                     value moved into `c` here
-   |         value borrowed, by `a`, here
+   |         |                     |              value is moved into `e` here
+   |         |                     value is moved into `c` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:52:23
@@ -117,8 +117,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                       -----^^^-----
    |                       |       |
-   |                       |       value moved into `c` here
-   |                       value borrowed, by `b`, here
+   |                       |       value is moved into `c` here
+   |                       value is borrowed by `b` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:52:38
@@ -126,8 +126,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                                      -----^^^-
    |                                      |       |
-   |                                      |       value moved into `e` here
-   |                                      value borrowed, by `d`, here
+   |                                      |       value is moved into `e` here
+   |                                      value is borrowed by `d` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:59:9
@@ -135,9 +135,9 @@ error: cannot move out of value because it is borrowed
 LL |         ref mut a @ Some([b, mut c]) => {}
    |         ---------^^^^^^^^^-^^-----^^
    |         |                 |  |
-   |         |                 |  value moved into `c` here
-   |         |                 value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |                 |  value is moved into `c` here
+   |         |                 value is moved into `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:64:9
@@ -145,8 +145,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some(b) => {}
    |         -----^^^^^^^^-^
    |         |            |
-   |         |            value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |            value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:69:9
@@ -154,9 +154,9 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |         -----^^^^^^^^^^^^^^^^^-----^^^^^^^^^^-^^
    |         |                     |              |
-   |         |                     |              value moved into `e` here
-   |         |                     value moved into `c` here
-   |         value borrowed, by `a`, here
+   |         |                     |              value is moved into `e` here
+   |         |                     value is moved into `c` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:69:23
@@ -164,8 +164,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                       -----^^^-----
    |                       |       |
-   |                       |       value moved into `c` here
-   |                       value borrowed, by `b`, here
+   |                       |       value is moved into `c` here
+   |                       value is borrowed by `b` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:69:38
@@ -173,8 +173,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                                      -----^^^-
    |                                      |       |
-   |                                      |       value moved into `e` here
-   |                                      value borrowed, by `d`, here
+   |                                      |       value is moved into `e` here
+   |                                      value is borrowed by `d` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:78:9
@@ -182,9 +182,9 @@ error: cannot move out of value because it is borrowed
 LL |         ref mut a @ Some([b, mut c]) => {}
    |         ---------^^^^^^^^^-^^-----^^
    |         |                 |  |
-   |         |                 |  value moved into `c` here
-   |         |                 value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |                 |  value is moved into `c` here
+   |         |                 value is moved into `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:11:11
@@ -192,8 +192,8 @@ error: cannot move out of value because it is borrowed
 LL |     fn f1(ref a @ b: U) {}
    |           -----^^^-
    |           |       |
-   |           |       value moved into `b` here
-   |           value borrowed, by `a`, here
+   |           |       value is moved into `b` here
+   |           value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:14:11
@@ -201,9 +201,9 @@ error: cannot move out of value because it is borrowed
 LL |     fn f2(ref a @ (ref b @ mut c, ref d @ e): (U, U)) {}
    |           -----^^^^^^^^^^^^-----^^^^^^^^^^-^
    |           |                |              |
-   |           |                |              value moved into `e` here
-   |           |                value moved into `c` here
-   |           value borrowed, by `a`, here
+   |           |                |              value is moved into `e` here
+   |           |                value is moved into `c` here
+   |           value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:14:20
@@ -211,8 +211,8 @@ error: cannot move out of value because it is borrowed
 LL |     fn f2(ref a @ (ref b @ mut c, ref d @ e): (U, U)) {}
    |                    -----^^^-----
    |                    |       |
-   |                    |       value moved into `c` here
-   |                    value borrowed, by `b`, here
+   |                    |       value is moved into `c` here
+   |                    value is borrowed by `b` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:14:35
@@ -220,8 +220,8 @@ error: cannot move out of value because it is borrowed
 LL |     fn f2(ref a @ (ref b @ mut c, ref d @ e): (U, U)) {}
    |                                   -----^^^-
    |                                   |       |
-   |                                   |       value moved into `e` here
-   |                                   value borrowed, by `d`, here
+   |                                   |       value is moved into `e` here
+   |                                   value is borrowed by `d` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-by-move-and-ref.rs:20:11
@@ -229,9 +229,9 @@ error: cannot move out of value because it is borrowed
 LL |     fn f3(ref mut a @ [b, mut c]: [U; 2]) {}
    |           ---------^^^^-^^-----^
    |           |            |  |
-   |           |            |  value moved into `c` here
-   |           |            value moved into `b` here
-   |           value borrowed, by `a`, here
+   |           |            |  value is moved into `c` here
+   |           |            value is moved into `b` here
+   |           value is mutably borrowed by `a` here
 
 error[E0382]: borrow of partially moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:30:9
diff --git a/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr b/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
index 8546b4bb477..f51b5041858 100644
--- a/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
+++ b/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
@@ -4,8 +4,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut z @ &mut Some(ref a) => {
    |         ---------^^^^^^^^^^^^^-----^
    |         |                     |
-   |         |                     immutable borrow, by `a`, occurs here
-   |         mutable borrow, by `z`, occurs here
+   |         |                     value is borrowed by `a` here
+   |         value is mutably borrowed by `z` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:33:9
@@ -13,9 +13,9 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ (ref b @ ref mut c) = u(); // sub-in-sub
    |         ---------^^^^-----------------^
    |         |            |       |
-   |         |            |       another mutable borrow, by `c`, occurs here
-   |         |            also borrowed as immutable, by `b`, here
-   |         first mutable borrow, by `a`, occurs here
+   |         |            |       value is mutably borrowed by `c` here
+   |         |            value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:33:22
@@ -23,8 +23,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref mut a @ (ref b @ ref mut c) = u(); // sub-in-sub
    |                      -----^^^---------
    |                      |       |
-   |                      |       mutable borrow, by `c`, occurs here
-   |                      immutable borrow, by `b`, occurs here
+   |                      |       value is mutably borrowed by `c` here
+   |                      value is borrowed by `b` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:37:9
@@ -32,8 +32,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ ref mut b = U;
    |         -----^^^---------
    |         |       |
-   |         |       mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |       value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:39:9
@@ -41,8 +41,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ ref b = U;
    |         ---------^^^-----
    |         |           |
-   |         |           immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |           value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:41:9
@@ -50,9 +50,9 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
    |         |        |          |
-   |         |        |          mutable borrow, by `c`, occurs here
-   |         |        mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |        |          value is mutably borrowed by `c` here
+   |         |        value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:43:9
@@ -60,9 +60,9 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ (ref b, ref c) = (U, U);
    |         ---------^^^^-----^^-----^
    |         |            |      |
-   |         |            |      immutable borrow, by `c`, occurs here
-   |         |            immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |            |      value is borrowed by `c` here
+   |         |            value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:46:9
@@ -70,8 +70,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ ref b = u();
    |         ---------^^^-----
    |         |           |
-   |         |           immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |           value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:51:9
@@ -79,8 +79,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ ref mut b = u();
    |         -----^^^---------
    |         |       |
-   |         |       mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |       value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:57:9
@@ -88,8 +88,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ ref b = U;
    |         ---------^^^-----
    |         |           |
-   |         |           immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |           value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:61:9
@@ -97,8 +97,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ ref mut b = U;
    |         -----^^^---------
    |         |       |
-   |         |       mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |       value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:67:9
@@ -106,8 +106,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |         ---------^^^^^^-----^
    |         |              |
-   |         |              immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |              value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:67:33
@@ -115,8 +115,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |                                 ---------^^^^^^^-----^
    |                                 |               |
-   |                                 |               immutable borrow, by `b`, occurs here
-   |                                 mutable borrow, by `a`, occurs here
+   |                                 |               value is borrowed by `b` here
+   |                                 value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:76:9
@@ -124,8 +124,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |         -----^^^^^^---------^
    |         |          |
-   |         |          mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |          value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:76:33
@@ -133,8 +133,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |                                 -----^^^^^^^---------^
    |                                 |           |
-   |                                 |           mutable borrow, by `b`, occurs here
-   |                                 immutable borrow, by `a`, occurs here
+   |                                 |           value is mutably borrowed by `b` here
+   |                                 value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:87:9
@@ -142,8 +142,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
    |         -----^^^^^^---------^
    |         |          |
-   |         |          mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |          value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:87:33
@@ -151,8 +151,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
    |                                 -----^^^^^^^---------^
    |                                 |           |
-   |                                 |           mutable borrow, by `b`, occurs here
-   |                                 immutable borrow, by `a`, occurs here
+   |                                 |           value is mutably borrowed by `b` here
+   |                                 value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:94:9
@@ -160,8 +160,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
    |         ---------^^^^^^-----^
    |         |              |
-   |         |              immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |              value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:94:33
@@ -169,8 +169,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
    |                                 ---------^^^^^^^-----^
    |                                 |               |
-   |                                 |               immutable borrow, by `b`, occurs here
-   |                                 mutable borrow, by `a`, occurs here
+   |                                 |               value is borrowed by `b` here
+   |                                 value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:101:9
@@ -178,8 +178,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
    |         -----^^^^^^---------^
    |         |          |
-   |         |          mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |          value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:101:33
@@ -187,8 +187,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
    |                                 -----^^^^^^^---------^
    |                                 |           |
-   |                                 |           mutable borrow, by `b`, occurs here
-   |                                 immutable borrow, by `a`, occurs here
+   |                                 |           value is mutably borrowed by `b` here
+   |                                 value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:109:9
@@ -196,8 +196,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
    |         ---------^^^^^^-----^
    |         |              |
-   |         |              immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |              value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:109:33
@@ -205,8 +205,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
    |                                 ---------^^^^^^^-----^
    |                                 |               |
-   |                                 |               immutable borrow, by `b`, occurs here
-   |                                 mutable borrow, by `a`, occurs here
+   |                                 |               value is borrowed by `b` here
+   |                                 value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:117:9
@@ -214,9 +214,9 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
    |         |        |          |
-   |         |        |          mutable borrow, by `c`, occurs here
-   |         |        mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |        |          value is mutably borrowed by `c` here
+   |         |        value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:123:9
@@ -224,9 +224,9 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
    |         |        |          |
-   |         |        |          mutable borrow, by `c`, occurs here
-   |         |        mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |        |          value is mutably borrowed by `c` here
+   |         |        value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:129:9
@@ -234,9 +234,9 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
    |         |        |          |
-   |         |        |          mutable borrow, by `c`, occurs here
-   |         |        mutable borrow, by `b`, occurs here
-   |         immutable borrow, by `a`, occurs here
+   |         |        |          value is mutably borrowed by `c` here
+   |         |        value is mutably borrowed by `b` here
+   |         value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:134:9
@@ -244,9 +244,9 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     let ref mut a @ (ref b, ref c) = (U, U);
    |         ---------^^^^-----^^-----^
    |         |            |      |
-   |         |            |      immutable borrow, by `c`, occurs here
-   |         |            immutable borrow, by `b`, occurs here
-   |         mutable borrow, by `a`, occurs here
+   |         |            |      value is borrowed by `c` here
+   |         |            value is borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:22:11
@@ -254,8 +254,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     fn f1(ref a @ ref mut b: U) {}
    |           -----^^^---------
    |           |       |
-   |           |       mutable borrow, by `b`, occurs here
-   |           immutable borrow, by `a`, occurs here
+   |           |       value is mutably borrowed by `b` here
+   |           value is borrowed by `a` here
 
 error: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:24:11
@@ -263,8 +263,8 @@ error: cannot borrow value as immutable because it is also borrowed as mutable
 LL |     fn f2(ref mut a @ ref b: U) {}
    |           ---------^^^-----
    |           |           |
-   |           |           immutable borrow, by `b`, occurs here
-   |           mutable borrow, by `a`, occurs here
+   |           |           value is borrowed by `b` here
+   |           value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:26:11
@@ -272,8 +272,8 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     fn f3(ref a @ [ref b, ref mut mid @ .., ref c]: [U; 4]) {}
    |           -----^^^^^^^^^^^----------------^^^^^^^^
    |           |               |
-   |           |               mutable borrow, by `mid`, occurs here
-   |           immutable borrow, by `a`, occurs here
+   |           |               value is mutably borrowed by `mid` here
+   |           value is borrowed by `a` here
 
 error: cannot borrow value as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:28:22
@@ -281,9 +281,9 @@ error: cannot borrow value as mutable because it is also borrowed as immutable
 LL |     fn f4_also_moved(ref a @ ref mut b @ c: U) {}
    |                      -----^^^-------------
    |                      |       |           |
-   |                      |       |           also moved into `c` here
-   |                      |       mutable borrow, by `b`, occurs here
-   |                      immutable borrow, by `a`, occurs here
+   |                      |       |           value is moved into `c` here
+   |                      |       value is mutably borrowed by `b` here
+   |                      value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:28:30
@@ -291,8 +291,8 @@ error: cannot move out of value because it is borrowed
 LL |     fn f4_also_moved(ref a @ ref mut b @ c: U) {}
    |                              ---------^^^-
    |                              |           |
-   |                              |           value moved into `c` here
-   |                              value borrowed, by `b`, here
+   |                              |           value is moved into `c` here
+   |                              value is mutably borrowed by `b` here
 
 error[E0502]: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:8:31
diff --git a/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr b/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
index ad4ce7952ca..a0cb04a064e 100644
--- a/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
+++ b/tests/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
@@ -4,8 +4,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
    |         |           |
-   |         |           another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:29:9
@@ -13,8 +13,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
    |         |           |
-   |         |           another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:33:9
@@ -22,8 +22,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
    |         |           |
-   |         |           another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:36:9
@@ -31,8 +31,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
    |         |           |
-   |         |           another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:39:9
@@ -40,8 +40,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
    |         |           |
-   |         |           another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |           value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:44:9
@@ -49,18 +49,18 @@ error: cannot borrow value as mutable more than once at a time
 LL |       let ref mut a @ (
    |           ^--------
    |           |
-   |  _________first mutable borrow, by `a`, occurs here
+   |  _________value is mutably borrowed by `a` here
    | |
 LL | |
 LL | |         ref mut b,
-   | |         --------- another mutable borrow, by `b`, occurs here
+   | |         --------- value is mutably borrowed by `b` here
 LL | |         [
 LL | |             ref mut c,
-   | |             --------- another mutable borrow, by `c`, occurs here
+   | |             --------- value is mutably borrowed by `c` here
 LL | |             ref mut d,
-   | |             --------- another mutable borrow, by `d`, occurs here
+   | |             --------- value is mutably borrowed by `d` here
 LL | |             ref e,
-   | |             ----- also borrowed as immutable, by `e`, here
+   | |             ----- value is borrowed by `e` here
 LL | |         ]
 LL | |     ) = (U, [U, U, U]);
    | |_____^
@@ -71,18 +71,18 @@ error: cannot borrow value as mutable more than once at a time
 LL |       let ref mut a @ (
    |           ^--------
    |           |
-   |  _________first mutable borrow, by `a`, occurs here
+   |  _________value is mutably borrowed by `a` here
    | |
 LL | |
 LL | |             ref mut b,
-   | |             --------- another mutable borrow, by `b`, occurs here
+   | |             --------- value is mutably borrowed by `b` here
 LL | |             [
 LL | |                 ref mut c,
-   | |                 --------- another mutable borrow, by `c`, occurs here
+   | |                 --------- value is mutably borrowed by `c` here
 LL | |                 ref mut d,
-   | |                 --------- another mutable borrow, by `d`, occurs here
+   | |                 --------- value is mutably borrowed by `d` here
 LL | |                 ref e,
-   | |                 ----- also borrowed as immutable, by `e`, here
+   | |                 ----- value is borrowed by `e` here
 LL | |             ]
 LL | |         ) = (u(), [u(), u(), u()]);
    | |_________^
@@ -157,8 +157,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
    |         |              |
-   |         |              another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |              value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:76:37
@@ -166,8 +166,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
    |                                     |               |
-   |                                     |               another mutable borrow, by `b`, occurs here
-   |                                     first mutable borrow, by `a`, occurs here
+   |                                     |               value is mutably borrowed by `b` here
+   |                                     value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:82:9
@@ -175,8 +175,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
    |         |              |
-   |         |              another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |              value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:82:37
@@ -184,8 +184,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
    |                                     |               |
-   |                                     |               another mutable borrow, by `b`, occurs here
-   |                                     first mutable borrow, by `a`, occurs here
+   |                                     |               value is mutably borrowed by `b` here
+   |                                     value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:89:9
@@ -193,8 +193,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
    |         |              |
-   |         |              another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |              value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:89:37
@@ -202,8 +202,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
    |                                     |               |
-   |                                     |               another mutable borrow, by `b`, occurs here
-   |                                     first mutable borrow, by `a`, occurs here
+   |                                     |               value is mutably borrowed by `b` here
+   |                                     value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:101:9
@@ -211,8 +211,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
    |         |              |
-   |         |              another mutable borrow, by `b`, occurs here
-   |         first mutable borrow, by `a`, occurs here
+   |         |              value is mutably borrowed by `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:101:37
@@ -220,8 +220,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
    |                                     |               |
-   |                                     |               another mutable borrow, by `b`, occurs here
-   |                                     first mutable borrow, by `a`, occurs here
+   |                                     |               value is mutably borrowed by `b` here
+   |                                     value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:8:11
@@ -229,8 +229,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     fn f1(ref mut a @ ref mut b: U) {}
    |           ---------^^^---------
    |           |           |
-   |           |           another mutable borrow, by `b`, occurs here
-   |           first mutable borrow, by `a`, occurs here
+   |           |           value is mutably borrowed by `b` here
+   |           value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:10:11
@@ -238,8 +238,8 @@ error: cannot borrow value as mutable more than once at a time
 LL |     fn f2(ref mut a @ ref mut b: U) {}
    |           ---------^^^---------
    |           |           |
-   |           |           another mutable borrow, by `b`, occurs here
-   |           first mutable borrow, by `a`, occurs here
+   |           |           value is mutably borrowed by `b` here
+   |           value is mutably borrowed by `a` here
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:13:9
@@ -247,13 +247,13 @@ error: cannot borrow value as mutable more than once at a time
 LL |           ref mut a @ [
    |           ^--------
    |           |
-   |  _________first mutable borrow, by `a`, occurs here
+   |  _________value is mutably borrowed by `a` here
    | |
 LL | |
 LL | |             [ref b @ .., _],
-   | |              ---------- also borrowed as immutable, by `b`, here
+   | |              ---------- value is borrowed by `b` here
 LL | |             [_, ref mut mid @ ..],
-   | |                 ---------------- another mutable borrow, by `mid`, occurs here
+   | |                 ---------------- value is mutably borrowed by `mid` here
 LL | |             ..,
 LL | |             [..],
 LL | |         ] : [[U; 4]; 5]
@@ -265,9 +265,9 @@ error: cannot borrow value as mutable more than once at a time
 LL |     fn f4_also_moved(ref mut a @ ref mut b @ c: U) {}
    |                      ---------^^^-------------
    |                      |           |           |
-   |                      |           |           also moved into `c` here
-   |                      |           another mutable borrow, by `b`, occurs here
-   |                      first mutable borrow, by `a`, occurs here
+   |                      |           |           value is moved into `c` here
+   |                      |           value is mutably borrowed by `b` here
+   |                      value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/borrowck-pat-ref-mut-twice.rs:21:34
@@ -275,8 +275,8 @@ error: cannot move out of value because it is borrowed
 LL |     fn f4_also_moved(ref mut a @ ref mut b @ c: U) {}
    |                                  ---------^^^-
    |                                  |           |
-   |                                  |           value moved into `c` here
-   |                                  value borrowed, by `b`, here
+   |                                  |           value is moved into `c` here
+   |                                  value is mutably borrowed by `b` here
 
 error[E0499]: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:29:9
diff --git a/tests/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr b/tests/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
index 638bdd6db76..73ebbf48118 100644
--- a/tests/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
+++ b/tests/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
@@ -4,8 +4,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref a @ b = NotCopy;
    |         -----^^^-
    |         |       |
-   |         |       value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |       value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/default-binding-modes-both-sides-independent.rs:29:9
@@ -13,8 +13,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref mut a @ b = NotCopy;
    |         ---------^^^-
    |         |           |
-   |         |           value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |           value is moved into `b` here
+   |         value is mutably borrowed by `a` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/default-binding-modes-both-sides-independent.rs:34:12
@@ -22,8 +22,8 @@ error: cannot move out of value because it is borrowed
 LL |         Ok(ref a @ b) | Err(b @ ref a) => {
    |            -----^^^-
    |            |       |
-   |            |       value moved into `b` here
-   |            value borrowed, by `a`, here
+   |            |       value is moved into `b` here
+   |            value is borrowed by `a` here
 
 error: borrow of moved value
   --> $DIR/default-binding-modes-both-sides-independent.rs:34:29
@@ -46,8 +46,8 @@ error: cannot move out of value because it is borrowed
 LL |         ref a @ b => {
    |         -----^^^-
    |         |       |
-   |         |       value moved into `b` here
-   |         value borrowed, by `a`, here
+   |         |       value is moved into `b` here
+   |         value is borrowed by `a` here
 
 error[E0382]: borrow of moved value
   --> $DIR/default-binding-modes-both-sides-independent.rs:29:9
diff --git a/tests/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr b/tests/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
index 1b93267b397..c7c7c074f7c 100644
--- a/tests/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
+++ b/tests/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `arr[..]` because it is borrowed
   --> $DIR/borrowck-move-ref-pattern.rs:8:24
    |
+LL |     let mut arr = [U, U, U, U, U];
+   |         ------- binding `arr` declared here
 LL |     let hold_all = &arr;
    |                    ---- borrow of `arr` occurs here
 LL |     let [ref _x0_hold, _x1, ref xs_hold @ ..] = arr;
diff --git a/tests/ui/proc-macro/allowed-signatures.rs b/tests/ui/proc-macro/allowed-signatures.rs
new file mode 100644
index 00000000000..86850876112
--- /dev/null
+++ b/tests/ui/proc-macro/allowed-signatures.rs
@@ -0,0 +1,26 @@
+// check-pass
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![allow(private_in_public)]
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn foo<T>(t: T) -> TokenStream {
+  TokenStream::new()
+}
+
+trait Project {
+    type Assoc;
+}
+
+impl Project for () {
+    type Assoc = TokenStream;
+}
+
+#[proc_macro]
+pub fn uwu(_input: <() as Project>::Assoc) -> <() as Project>::Assoc {
+    TokenStream::new()
+}
diff --git a/tests/ui/proc-macro/proc-macro-abi.rs b/tests/ui/proc-macro/proc-macro-abi.rs
new file mode 100644
index 00000000000..873660a5b3a
--- /dev/null
+++ b/tests/ui/proc-macro/proc-macro-abi.rs
@@ -0,0 +1,31 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![allow(warnings)]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub extern "C" fn abi(a: TokenStream) -> TokenStream {
+    //~^ ERROR proc macro functions may not be `extern "C"`
+    a
+}
+
+#[proc_macro]
+pub extern "system" fn abi2(a: TokenStream) -> TokenStream {
+    //~^ ERROR proc macro functions may not be `extern "system"`
+    a
+}
+
+#[proc_macro]
+pub extern fn abi3(a: TokenStream) -> TokenStream {
+    //~^ ERROR proc macro functions may not be `extern "C"`
+    a
+}
+
+#[proc_macro]
+pub extern "Rust" fn abi4(a: TokenStream) -> TokenStream {
+    a
+}
diff --git a/tests/ui/proc-macro/proc-macro-abi.stderr b/tests/ui/proc-macro/proc-macro-abi.stderr
new file mode 100644
index 00000000000..9a781be0996
--- /dev/null
+++ b/tests/ui/proc-macro/proc-macro-abi.stderr
@@ -0,0 +1,20 @@
+error: proc macro functions may not be `extern "C"`
+  --> $DIR/proc-macro-abi.rs:11:1
+   |
+LL | pub extern "C" fn abi(a: TokenStream) -> TokenStream {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: proc macro functions may not be `extern "system"`
+  --> $DIR/proc-macro-abi.rs:17:1
+   |
+LL | pub extern "system" fn abi2(a: TokenStream) -> TokenStream {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: proc macro functions may not be `extern "C"`
+  --> $DIR/proc-macro-abi.rs:23:1
+   |
+LL | pub extern fn abi3(a: TokenStream) -> TokenStream {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/proc-macro/signature-proc-macro-attribute.rs b/tests/ui/proc-macro/signature-proc-macro-attribute.rs
new file mode 100644
index 00000000000..51abc8e7d3e
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro-attribute.rs
@@ -0,0 +1,32 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro_attribute]
+pub fn bad_input(input: String) -> TokenStream {
+    //~^ ERROR mismatched attribute proc macro signature
+    ::proc_macro::TokenStream::new()
+}
+
+#[proc_macro_attribute]
+pub fn bad_output(input: TokenStream) -> String {
+    //~^ ERROR mismatched attribute proc macro signature
+    //~| ERROR mismatched attribute proc macro signature
+    String::from("blah")
+}
+
+#[proc_macro_attribute]
+pub fn bad_everything(input: String) -> String {
+    //~^ ERROR mismatched attribute proc macro signature
+    //~| ERROR mismatched attribute proc macro signature
+    input
+}
+
+#[proc_macro_attribute]
+pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+    //~^ ERROR mismatched attribute proc macro signature
+}
diff --git a/tests/ui/proc-macro/signature-proc-macro-attribute.stderr b/tests/ui/proc-macro/signature-proc-macro-attribute.stderr
new file mode 100644
index 00000000000..abf7a6f3ce9
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro-attribute.stderr
@@ -0,0 +1,42 @@
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:10:1
+   |
+LL | pub fn bad_input(input: String) -> TokenStream {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attribute proc macro must have two arguments of type `proc_macro::TokenStream`
+
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:16:42
+   |
+LL | pub fn bad_output(input: TokenStream) -> String {
+   |                                          ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: attribute proc macros must have a signature of `fn(TokenStream, TokenStream) -> TokenStream`
+
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:16:1
+   |
+LL | pub fn bad_output(input: TokenStream) -> String {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attribute proc macro must have two arguments of type `proc_macro::TokenStream`
+
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:23:41
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   |                                         ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: attribute proc macros must have a signature of `fn(TokenStream, TokenStream) -> TokenStream`
+
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:23:1
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attribute proc macro must have two arguments of type `proc_macro::TokenStream`
+
+error: mismatched attribute proc macro signature
+  --> $DIR/signature-proc-macro-attribute.rs:30:49
+   |
+LL | pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+   |                                                 ^^^^^^^^^ found unexpected argument
+
+error: aborting due to 6 previous errors
+
diff --git a/tests/ui/proc-macro/signature-proc-macro-derive.rs b/tests/ui/proc-macro/signature-proc-macro-derive.rs
new file mode 100644
index 00000000000..f2fd824b675
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro-derive.rs
@@ -0,0 +1,31 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(Blah)]
+pub fn bad_input(input: String) -> TokenStream {
+    //~^ ERROR mismatched derive proc macro signature
+    TokenStream::new()
+}
+
+#[proc_macro_derive(Bleh)]
+pub fn bad_output(input: TokenStream) -> String {
+    //~^ ERROR mismatched derive proc macro signature
+    String::from("blah")
+}
+
+#[proc_macro_derive(Bluh)]
+pub fn bad_everything(input: String) -> String {
+    //~^ ERROR mismatched derive proc macro signature
+    //~| ERROR mismatched derive proc macro signature
+    input
+}
+
+#[proc_macro_derive(Blih)]
+pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+    //~^ ERROR mismatched derive proc macro signature
+}
diff --git a/tests/ui/proc-macro/signature-proc-macro-derive.stderr b/tests/ui/proc-macro/signature-proc-macro-derive.stderr
new file mode 100644
index 00000000000..a358ae27703
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro-derive.stderr
@@ -0,0 +1,40 @@
+error: mismatched derive proc macro signature
+  --> $DIR/signature-proc-macro-derive.rs:10:25
+   |
+LL | pub fn bad_input(input: String) -> TokenStream {
+   |                         ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature-proc-macro-derive.rs:16:42
+   |
+LL | pub fn bad_output(input: TokenStream) -> String {
+   |                                          ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature-proc-macro-derive.rs:22:41
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   |                                         ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature-proc-macro-derive.rs:22:30
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   |                              ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature-proc-macro-derive.rs:29:33
+   |
+LL | pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^ found unexpected arguments
+
+error: aborting due to 5 previous errors
+
diff --git a/tests/ui/proc-macro/signature-proc-macro.rs b/tests/ui/proc-macro/signature-proc-macro.rs
new file mode 100644
index 00000000000..54770aacd1a
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro.rs
@@ -0,0 +1,31 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn bad_input(input: String) -> TokenStream {
+    //~^ ERROR mismatched function-like proc macro signature
+    ::proc_macro::TokenStream::new()
+}
+
+#[proc_macro]
+pub fn bad_output(input: TokenStream) -> String {
+    //~^ ERROR mismatched function-like proc macro signature
+    String::from("blah")
+}
+
+#[proc_macro]
+pub fn bad_everything(input: String) -> String {
+    //~^ ERROR mismatched function-like proc macro signature
+    //~| ERROR mismatched function-like proc macro signature
+    input
+}
+
+#[proc_macro]
+pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+    //~^ ERROR mismatched function-like proc macro signature
+}
diff --git a/tests/ui/proc-macro/signature-proc-macro.stderr b/tests/ui/proc-macro/signature-proc-macro.stderr
new file mode 100644
index 00000000000..4b14a54e675
--- /dev/null
+++ b/tests/ui/proc-macro/signature-proc-macro.stderr
@@ -0,0 +1,40 @@
+error: mismatched function-like proc macro signature
+  --> $DIR/signature-proc-macro.rs:10:25
+   |
+LL | pub fn bad_input(input: String) -> TokenStream {
+   |                         ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: function-like proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched function-like proc macro signature
+  --> $DIR/signature-proc-macro.rs:16:42
+   |
+LL | pub fn bad_output(input: TokenStream) -> String {
+   |                                          ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: function-like proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched function-like proc macro signature
+  --> $DIR/signature-proc-macro.rs:22:41
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   |                                         ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: function-like proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched function-like proc macro signature
+  --> $DIR/signature-proc-macro.rs:22:30
+   |
+LL | pub fn bad_everything(input: String) -> String {
+   |                              ^^^^^^ found std::string::String, expected type `proc_macro::TokenStream`
+   |
+   = note: function-like proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched function-like proc macro signature
+  --> $DIR/signature-proc-macro.rs:29:33
+   |
+LL | pub fn too_many(a: TokenStream, b: TokenStream, c: String) -> TokenStream {
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^ found unexpected arguments
+
+error: aborting due to 5 previous errors
+
diff --git a/tests/ui/proc-macro/signature.rs b/tests/ui/proc-macro/signature.rs
index 2302238253e..11187aa31bd 100644
--- a/tests/ui/proc-macro/signature.rs
+++ b/tests/ui/proc-macro/signature.rs
@@ -8,6 +8,10 @@ extern crate proc_macro;
 
 #[proc_macro_derive(A)]
 pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
-    //~^ ERROR: expected a `Fn<(proc_macro::TokenStream,)>` closure, found `unsafe extern "C" fn
+    //~^ ERROR: mismatched derive proc macro signature
+    //~| mismatched derive proc macro signature
+    //~| mismatched derive proc macro signature
+    //~| proc macro functions may not be `extern
+    //~| proc macro functions may not be `unsafe
     loop {}
 }
diff --git a/tests/ui/proc-macro/signature.stderr b/tests/ui/proc-macro/signature.stderr
index 79f2001da00..3dbe3f22a0d 100644
--- a/tests/ui/proc-macro/signature.stderr
+++ b/tests/ui/proc-macro/signature.stderr
@@ -1,20 +1,36 @@
-error[E0277]: expected a `Fn<(proc_macro::TokenStream,)>` closure, found `unsafe extern "C" fn(i32, u32) -> u32 {foo}`
+error: proc macro functions may not be `extern "C"`
   --> $DIR/signature.rs:10:1
    |
-LL | / pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
-LL | |
-LL | |     loop {}
-LL | | }
-   | | ^
-   | | |
-   | |_call the function in a closure: `|| unsafe { /* code */ }`
-   |   required by a bound introduced by this call
+LL | pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: proc macro functions may not be `unsafe`
+  --> $DIR/signature.rs:10:1
+   |
+LL | pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature.rs:10:49
+   |
+LL | pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
+   |                                                 ^^^ found u32, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature.rs:10:33
+   |
+LL | pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
+   |                                 ^^^ found i32, expected type `proc_macro::TokenStream`
+   |
+   = note: derive proc macros must have a signature of `fn(TokenStream) -> TokenStream`
+
+error: mismatched derive proc macro signature
+  --> $DIR/signature.rs:10:38
    |
-   = help: the trait `Fn<(proc_macro::TokenStream,)>` is not implemented for fn item `unsafe extern "C" fn(i32, u32) -> u32 {foo}`
-   = note: unsafe function cannot be called generically without an unsafe block
-note: required by a bound in `ProcMacro::custom_derive`
-  --> $SRC_DIR/proc_macro/src/bridge/client.rs:LL:COL
+LL | pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
+   |                                      ^^^^^^ found unexpected argument
 
-error: aborting due to previous error
+error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/regions/do-not-suggest-adding-bound-to-opaque-type.stderr b/tests/ui/regions/do-not-suggest-adding-bound-to-opaque-type.stderr
index 6ea238f302f..d76a83b0258 100644
--- a/tests/ui/regions/do-not-suggest-adding-bound-to-opaque-type.stderr
+++ b/tests/ui/regions/do-not-suggest-adding-bound-to-opaque-type.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/do-not-suggest-adding-bound-to-opaque-type.rs:9:7
    |
+LL |     let x = ();
+   |         - binding `x` declared here
 LL |     S(&x)
    |     --^^-
    |     | |
diff --git a/tests/ui/regions/higher-ranked-implied.rs b/tests/ui/regions/higher-ranked-implied.rs
new file mode 100644
index 00000000000..103884c5031
--- /dev/null
+++ b/tests/ui/regions/higher-ranked-implied.rs
@@ -0,0 +1,14 @@
+// FIXME: This test should pass as the first two fields add implied bounds that
+// `'a` is equal to `'b` while the last one should simply use that fact. With
+// the current implementation this errors. We have to be careful as implied bounds
+// are only sound if they're also correctly checked.
+
+struct Inv<T>(*mut T); // `T` is invariant.
+type A = for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>);
+type B = for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>);
+
+fn main() {
+    let x: A = |_, _, _| ();
+    let y: B = x; //~ ERROR mismatched types
+    let _: A = y; //~ ERROR mismatched types
+}
diff --git a/tests/ui/regions/higher-ranked-implied.stderr b/tests/ui/regions/higher-ranked-implied.stderr
new file mode 100644
index 00000000000..9d80eacd7c3
--- /dev/null
+++ b/tests/ui/regions/higher-ranked-implied.stderr
@@ -0,0 +1,21 @@
+error[E0308]: mismatched types
+  --> $DIR/higher-ranked-implied.rs:12:16
+   |
+LL |     let y: B = x;
+   |                ^ one type is more general than the other
+   |
+   = note: expected fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>)`
+              found fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>)`
+
+error[E0308]: mismatched types
+  --> $DIR/higher-ranked-implied.rs:13:16
+   |
+LL |     let _: A = y;
+   |                ^ one type is more general than the other
+   |
+   = note: expected fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>)`
+              found fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>)`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/regions/regions-addr-of-arg.stderr b/tests/ui/regions/regions-addr-of-arg.stderr
index e77289287e5..99060a9c7f5 100644
--- a/tests/ui/regions/regions-addr-of-arg.stderr
+++ b/tests/ui/regions/regions-addr-of-arg.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/regions-addr-of-arg.rs:5:30
    |
+LL | fn foo(a: isize) {
+   |        - binding `a` declared here
 LL |     let _p: &'static isize = &a;
    |             --------------   ^^ borrowed value does not live long enough
    |             |
diff --git a/tests/ui/regions/regions-free-region-ordering-caller1.stderr b/tests/ui/regions/regions-free-region-ordering-caller1.stderr
index 8ef7e22536b..c83cfc1c987 100644
--- a/tests/ui/regions/regions-free-region-ordering-caller1.stderr
+++ b/tests/ui/regions/regions-free-region-ordering-caller1.stderr
@@ -18,6 +18,8 @@ error[E0597]: `y` does not live long enough
 LL | fn call1<'a>(x: &'a usize) {
    |          -- lifetime `'a` defined here
 ...
+LL |     let y: usize = 3;
+   |         - binding `y` declared here
 LL |     let z: &'a & usize = &(&y);
    |            -----------    ^^^^ borrowed value does not live long enough
    |            |
diff --git a/tests/ui/regions/regions-infer-proc-static-upvar.stderr b/tests/ui/regions/regions-infer-proc-static-upvar.stderr
index 803d0d74491..c8a33bbc522 100644
--- a/tests/ui/regions/regions-infer-proc-static-upvar.stderr
+++ b/tests/ui/regions/regions-infer-proc-static-upvar.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/regions-infer-proc-static-upvar.rs:10:13
    |
+LL |       let x = 3;
+   |           - binding `x` declared here
 LL |       let y = &x;
    |               ^^ borrowed value does not live long enough
 LL | /     foo(move|| {
diff --git a/tests/ui/regions/regions-nested-fns.stderr b/tests/ui/regions/regions-nested-fns.stderr
index bb2740310f6..ee43f9fa572 100644
--- a/tests/ui/regions/regions-nested-fns.stderr
+++ b/tests/ui/regions/regions-nested-fns.stderr
@@ -13,6 +13,8 @@ LL |         ay = z;
 error[E0597]: `y` does not live long enough
   --> $DIR/regions-nested-fns.rs:5:18
    |
+LL |     let y = 3;
+   |         - binding `y` declared here
 LL |     let mut ay = &y;
    |                  ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/regions/regions-pattern-typing-issue-19552.stderr b/tests/ui/regions/regions-pattern-typing-issue-19552.stderr
index f77d94a24b8..18aec29ad0b 100644
--- a/tests/ui/regions/regions-pattern-typing-issue-19552.stderr
+++ b/tests/ui/regions/regions-pattern-typing-issue-19552.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `line` does not live long enough
   --> $DIR/regions-pattern-typing-issue-19552.rs:5:14
    |
+LL |     let line = String::new();
+   |         ---- binding `line` declared here
 LL |     match [&*line] {
    |              ^^^^ borrowed value does not live long enough
 LL |         [ word ] => { assert_static(word); }
diff --git a/tests/ui/regions/regions-pattern-typing-issue-19997.stderr b/tests/ui/regions/regions-pattern-typing-issue-19997.stderr
index ae60e3c0d5d..0abe77a8697 100644
--- a/tests/ui/regions/regions-pattern-typing-issue-19997.stderr
+++ b/tests/ui/regions/regions-pattern-typing-issue-19997.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `a1` because it is borrowed
   --> $DIR/regions-pattern-typing-issue-19997.rs:7:13
    |
 LL |     match (&a1,) {
-   |            --- borrow of `a1` occurs here
+   |            --- `a1` is borrowed here
 LL |         (&ref b0,) => {
 LL |             a1 = &f;
-   |             ^^^^^^^ assignment to borrowed `a1` occurs here
+   |             ^^^^^^^ `a1` is assigned to here but it was already borrowed
 LL |             drop(b0);
    |                  -- borrow later used here
 
diff --git a/tests/ui/reify-intrinsic.stderr b/tests/ui/reify-intrinsic.stderr
index f78f1d822bf..310b6c224e0 100644
--- a/tests/ui/reify-intrinsic.stderr
+++ b/tests/ui/reify-intrinsic.stderr
@@ -23,9 +23,7 @@ LL |         std::intrinsics::unlikely,
    |
    = note: expected fn item `extern "rust-intrinsic" fn(_) -> _ {likely}`
               found fn item `extern "rust-intrinsic" fn(_) -> _ {unlikely}`
-   = note: different `fn` items always have unique types, even if their signatures are the same
-   = help: change the expected type to be function pointer `extern "rust-intrinsic" fn(bool) -> bool`
-   = help: if the expected type is due to type inference, cast the expected `fn` to a function pointer: `likely as extern "rust-intrinsic" fn(bool) -> bool`
+   = note: different fn items have unique types, even if their signatures are the same
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/rfc-2008-non-exhaustive/borrowck-non-exhaustive.stderr b/tests/ui/rfc-2008-non-exhaustive/borrowck-non-exhaustive.stderr
index de730ce1030..ad84ebe3a50 100644
--- a/tests/ui/rfc-2008-non-exhaustive/borrowck-non-exhaustive.stderr
+++ b/tests/ui/rfc-2008-non-exhaustive/borrowck-non-exhaustive.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/borrowck-non-exhaustive.rs:12:11
    |
 LL |     let y = &mut x;
-   |             ------ borrow of `x` occurs here
+   |             ------ `x` is borrowed here
 LL |     match x {
    |           ^ use of borrowed `x`
 ...
diff --git a/tests/ui/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.stderr b/tests/ui/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.stderr
index 498a112fa9b..f34ccecdd45 100644
--- a/tests/ui/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.stderr
+++ b/tests/ui/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.stderr
@@ -37,6 +37,11 @@ help: add a block here
    |
 LL |     if let Some(n) = opt else {
    |                         ^
+help: remove the `if` if you meant to write a `let...else` statement
+  --> $DIR/ensure-that-let-else-does-not-interact-with-let-chains.rs:24:5
+   |
+LL |     if let Some(n) = opt else {
+   |     ^^
 
 error: this `if` expression is missing a block after the condition
   --> $DIR/ensure-that-let-else-does-not-interact-with-let-chains.rs:28:5
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
index cf5815df56e..07f6dc906c6 100644
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
+++ b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
@@ -5,12 +5,15 @@ LL | #[target_feature(enable = "sse2")]
    | ---------------------------------- `#[target_feature]` added here
 ...
 LL |     let foo: fn() = foo;
-   |              ----   ^^^ cannot coerce functions with `#[target_feature]` to safe function pointers
-   |              |
+   |              ----   ^^^
+   |              |      |
+   |              |      cannot coerce functions with `#[target_feature]` to safe function pointers
+   |              |      help: consider casting to a fn pointer: `foo as fn()`
    |              expected due to this
    |
    = note: expected fn pointer `fn()`
                  found fn item `fn() {foo}`
+   = note: fn items are distinct from fn pointers
    = note: functions with `#[target_feature]` can only be coerced to `unsafe` function pointers
 
 error: aborting due to previous error
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
index cf5815df56e..07f6dc906c6 100644
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
+++ b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
@@ -5,12 +5,15 @@ LL | #[target_feature(enable = "sse2")]
    | ---------------------------------- `#[target_feature]` added here
 ...
 LL |     let foo: fn() = foo;
-   |              ----   ^^^ cannot coerce functions with `#[target_feature]` to safe function pointers
-   |              |
+   |              ----   ^^^
+   |              |      |
+   |              |      cannot coerce functions with `#[target_feature]` to safe function pointers
+   |              |      help: consider casting to a fn pointer: `foo as fn()`
    |              expected due to this
    |
    = note: expected fn pointer `fn()`
                  found fn item `fn() {foo}`
+   = note: fn items are distinct from fn pointers
    = note: functions with `#[target_feature]` can only be coerced to `unsafe` function pointers
 
 error: aborting due to previous error
diff --git a/tests/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr b/tests/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr
index 5f93ad6e027..1c26eb8803d 100644
--- a/tests/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr
+++ b/tests/ui/rfcs/rfc-2528-type-changing-struct-update/lifetime-update.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `s` does not live long enough
   --> $DIR/lifetime-update.rs:20:17
    |
+LL |     let s = String::from("hello");
+   |         - binding `s` declared here
+...
 LL |         lt_str: &s,
    |                 ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.rs b/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.rs
index 0b3de0df2b8..d2254acb33f 100644
--- a/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.rs
+++ b/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.rs
@@ -365,4 +365,24 @@ mod unions {
     }
 }
 
+// https://github.com/rust-lang/rust/issues/106870
+mod multiple_predicates_with_same_span {
+    macro_rules! m {
+        ($($name:ident)+) => {
+            struct Inline<'a, $($name: 'a,)+>(&'a ($($name,)+));
+            //~^ ERROR: outlives requirements can be inferred
+            struct FullWhere<'a, $($name,)+>(&'a ($($name,)+)) where $($name: 'a,)+;
+            //~^ ERROR: outlives requirements can be inferred
+            struct PartialWhere<'a, $($name,)+>(&'a ($($name,)+)) where (): Sized, $($name: 'a,)+;
+            //~^ ERROR: outlives requirements can be inferred
+            struct Interleaved<'a, $($name,)+>(&'a ($($name,)+))
+            where
+                (): Sized,
+                $($name: 'a, $name: 'a, )+ //~ ERROR: outlives requirements can be inferred
+                $($name: 'a, $name: 'a, )+;
+        }
+    }
+    m!(T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15);
+}
+
 fn main() {}
diff --git a/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.stderr b/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.stderr
index 251d74094ca..f5ec287d291 100644
--- a/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.stderr
+++ b/tests/ui/rust-2018/edition-lint-infer-outlives-multispan.stderr
@@ -819,5 +819,61 @@ LL -     union BeeWhereAyTeeYooWhereOutlivesAyIsDebugBee<'a, 'b, T, U> where U:
 LL +     union BeeWhereAyTeeYooWhereOutlivesAyIsDebugBee<'a, 'b, T, U> where U: Debug,  {
    |
 
-error: aborting due to 68 previous errors
+error: outlives requirements can be inferred
+  --> $DIR/edition-lint-infer-outlives-multispan.rs:372:38
+   |
+LL |             struct Inline<'a, $($name: 'a,)+>(&'a ($($name,)+));
+   |                                      ^^^^ help: remove these bounds
+...
+LL |     m!(T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15);
+   |     --------------------------------------------------------- in this macro invocation
+   |
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: outlives requirements can be inferred
+  --> $DIR/edition-lint-infer-outlives-multispan.rs:374:64
+   |
+LL |             struct FullWhere<'a, $($name,)+>(&'a ($($name,)+)) where $($name: 'a,)+;
+   |                                                                ^^^^^^^^^^^^^^^^^^ help: remove these bounds
+...
+LL |     m!(T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15);
+   |     --------------------------------------------------------- in this macro invocation
+   |
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: outlives requirements can be inferred
+  --> $DIR/edition-lint-infer-outlives-multispan.rs:376:86
+   |
+LL |             struct PartialWhere<'a, $($name,)+>(&'a ($($name,)+)) where (): Sized, $($name: 'a,)+;
+   |                                                                                      ^^^^^^^^^ help: remove these bounds
+...
+LL |     m!(T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15);
+   |     --------------------------------------------------------- in this macro invocation
+   |
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: outlives requirements can be inferred
+  --> $DIR/edition-lint-infer-outlives-multispan.rs:381:19
+   |
+LL |                 $($name: 'a, $name: 'a, )+
+   |                   ^^^^^^^^^  ^^^^^^^^^
+LL |                 $($name: 'a, $name: 'a, )+;
+   |                   ^^^^^^^^^  ^^^^^^^^^
+...
+LL |     m!(T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15);
+   |     ---------------------------------------------------------
+   |     |
+   |     in this macro invocation
+   |     in this macro invocation
+   |     in this macro invocation
+   |     in this macro invocation
+   |
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: remove these bounds
+   |
+LL ~                 $(, , )+
+LL ~                 $(, , )+;
+   |
+
+error: aborting due to 72 previous errors
 
diff --git a/tests/ui/rust-2018/edition-lint-infer-outlives.fixed b/tests/ui/rust-2018/edition-lint-infer-outlives.fixed
index 13645244da0..868bdf2e068 100644
--- a/tests/ui/rust-2018/edition-lint-infer-outlives.fixed
+++ b/tests/ui/rust-2018/edition-lint-infer-outlives.fixed
@@ -791,5 +791,14 @@ struct StaticRef<T: 'static> {
     field: &'static T
 }
 
+struct TrailingCommaInWhereClause<'a, T, U>
+where
+    T: 'a,
+    
+    //~^ ERROR outlives requirements can be inferred
+{
+    tee: T,
+    yoo: &'a U
+}
 
 fn main() {}
diff --git a/tests/ui/rust-2018/edition-lint-infer-outlives.rs b/tests/ui/rust-2018/edition-lint-infer-outlives.rs
index d9486ba66f8..75783764ad6 100644
--- a/tests/ui/rust-2018/edition-lint-infer-outlives.rs
+++ b/tests/ui/rust-2018/edition-lint-infer-outlives.rs
@@ -791,5 +791,14 @@ struct StaticRef<T: 'static> {
     field: &'static T
 }
 
+struct TrailingCommaInWhereClause<'a, T, U>
+where
+    T: 'a,
+    U: 'a,
+    //~^ ERROR outlives requirements can be inferred
+{
+    tee: T,
+    yoo: &'a U
+}
 
 fn main() {}
diff --git a/tests/ui/rust-2018/edition-lint-infer-outlives.stderr b/tests/ui/rust-2018/edition-lint-infer-outlives.stderr
index faa9f21e38b..e655fb4842c 100644
--- a/tests/ui/rust-2018/edition-lint-infer-outlives.stderr
+++ b/tests/ui/rust-2018/edition-lint-infer-outlives.stderr
@@ -1,8 +1,8 @@
 error: outlives requirements can be inferred
-  --> $DIR/edition-lint-infer-outlives.rs:26:31
+  --> $DIR/edition-lint-infer-outlives.rs:797:5
    |
-LL |     struct TeeOutlivesAy<'a, T: 'a> {
-   |                               ^^^^ help: remove this bound
+LL |     U: 'a,
+   |     ^^^^^^ help: remove this bound
    |
 note: the lint level is defined here
   --> $DIR/edition-lint-infer-outlives.rs:4:9
@@ -11,6 +11,12 @@ LL | #![deny(explicit_outlives_requirements)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: outlives requirements can be inferred
+  --> $DIR/edition-lint-infer-outlives.rs:26:31
+   |
+LL |     struct TeeOutlivesAy<'a, T: 'a> {
+   |                               ^^^^ help: remove this bound
+
+error: outlives requirements can be inferred
   --> $DIR/edition-lint-infer-outlives.rs:31:40
    |
 LL |     struct TeeOutlivesAyIsDebug<'a, T: 'a + Debug> {
@@ -916,5 +922,5 @@ error: outlives requirements can be inferred
 LL |     union BeeWhereOutlivesAyTeeWhereDebug<'a, 'b, T> where 'b: 'a, T: Debug {
    |                                                            ^^^^^^^^ help: remove this bound
 
-error: aborting due to 152 previous errors
+error: aborting due to 153 previous errors
 
diff --git a/tests/ui/self/arbitrary_self_types_pointers_and_wrappers.rs b/tests/ui/self/arbitrary_self_types_pointers_and_wrappers.rs
index 65fec3becac..91aacedfc57 100644
--- a/tests/ui/self/arbitrary_self_types_pointers_and_wrappers.rs
+++ b/tests/ui/self/arbitrary_self_types_pointers_and_wrappers.rs
@@ -3,6 +3,7 @@
 #![feature(rustc_attrs)]
 
 use std::{
+    cell::Cell,
     ops::{Deref, CoerceUnsized, DispatchFromDyn},
     marker::Unsize,
 };
@@ -20,6 +21,20 @@ impl<T: ?Sized> Deref for Ptr<T> {
 impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {}
 impl<T: Unsize<U> + ?Sized, U: ?Sized> DispatchFromDyn<Ptr<U>> for Ptr<T> {}
 
+
+struct CellPtr<'a, T: ?Sized>(Cell<&'a T>);
+
+impl<'a, T: ?Sized> Deref for CellPtr<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        self.0.get()
+    }
+}
+
+impl<'a, T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<CellPtr<'a, U>> for CellPtr<'a, T> {}
+impl<'a, T: Unsize<U> + ?Sized, U: ?Sized> DispatchFromDyn<CellPtr<'a, U>> for CellPtr<'a, T> {}
+
 struct Wrapper<T: ?Sized>(T);
 
 impl<T: ?Sized> Deref for Wrapper<T> {
@@ -42,6 +57,7 @@ trait Trait {
     fn ptr_wrapper(self: Ptr<Wrapper<Self>>) -> i32;
     fn wrapper_ptr(self: Wrapper<Ptr<Self>>) -> i32;
     fn wrapper_ptr_wrapper(self: Wrapper<Ptr<Wrapper<Self>>>) -> i32;
+    fn cell(self: CellPtr<Self>) -> i32;
 }
 
 impl Trait for i32 {
@@ -54,6 +70,9 @@ impl Trait for i32 {
     fn wrapper_ptr_wrapper(self: Wrapper<Ptr<Wrapper<Self>>>) -> i32 {
         ***self
     }
+    fn cell(self: CellPtr<Self>) -> i32 {
+        *self
+    }
 }
 
 fn main() {
@@ -65,4 +84,7 @@ fn main() {
 
     let wpw = Wrapper(Ptr(Box::new(Wrapper(7)))) as Wrapper<Ptr<Wrapper<dyn Trait>>>;
     assert_eq!(wpw.wrapper_ptr_wrapper(), 7);
+
+    let c = CellPtr(Cell::new(&8)) as CellPtr<dyn Trait>;
+    assert_eq!(c.cell(), 8);
 }
diff --git a/tests/ui/self/issue-61882-2.stderr b/tests/ui/self/issue-61882-2.stderr
index 0b8e134c966..6faa4477d8c 100644
--- a/tests/ui/self/issue-61882-2.stderr
+++ b/tests/ui/self/issue-61882-2.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/issue-61882-2.rs:6:14
    |
+LL |         let x = 0;
+   |             - binding `x` declared here
 LL |         Self(&x);
    |              ^^
    |              |
diff --git a/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr b/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
index 48b42bc7825..9711dad8078 100644
--- a/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
+++ b/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
@@ -47,6 +47,9 @@ LL |         foo(f);
 error[E0505]: cannot move out of `f` because it is borrowed
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:55:16
    |
+LL |     let mut f = move |g: Box<dyn FnMut(isize)>, b: isize| {
+   |         ----- binding `f` declared here
+...
 LL |     f(Box::new(|a| {
    |     -          ^^^ move out of `f` occurs here
    |     |
diff --git a/tests/ui/span/borrowck-let-suggestion-suffixes.rs b/tests/ui/span/borrowck-let-suggestion-suffixes.rs
index 18abfb5c3fb..ad556f281df 100644
--- a/tests/ui/span/borrowck-let-suggestion-suffixes.rs
+++ b/tests/ui/span/borrowck-let-suggestion-suffixes.rs
@@ -8,6 +8,7 @@ fn f() {
 
     {
         let young = ['y'];       // statement 3
+        //~^ NOTE binding `young` declared here
 
         v2.push(&young[0]);      // statement 4
         //~^ ERROR `young[_]` does not live long enough
diff --git a/tests/ui/span/borrowck-let-suggestion-suffixes.stderr b/tests/ui/span/borrowck-let-suggestion-suffixes.stderr
index 2dc29a78d20..545b235a552 100644
--- a/tests/ui/span/borrowck-let-suggestion-suffixes.stderr
+++ b/tests/ui/span/borrowck-let-suggestion-suffixes.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `young[_]` does not live long enough
-  --> $DIR/borrowck-let-suggestion-suffixes.rs:12:17
+  --> $DIR/borrowck-let-suggestion-suffixes.rs:13:17
    |
+LL |         let young = ['y'];       // statement 3
+   |             ----- binding `young` declared here
+...
 LL |         v2.push(&young[0]);      // statement 4
    |                 ^^^^^^^^^ borrowed value does not live long enough
 ...
@@ -11,7 +14,7 @@ LL |     (v1, v2, v3, /* v4 is above. */ v5).use_ref();
    |          -- borrow later used here
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/borrowck-let-suggestion-suffixes.rs:19:14
+  --> $DIR/borrowck-let-suggestion-suffixes.rs:20:14
    |
 LL |     v3.push(&id('x'));           // statement 6
    |              ^^^^^^^ - temporary value is freed at the end of this statement
@@ -28,7 +31,7 @@ LL ~     v3.push(&binding);           // statement 6
    |
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/borrowck-let-suggestion-suffixes.rs:29:18
+  --> $DIR/borrowck-let-suggestion-suffixes.rs:30:18
    |
 LL |         v4.push(&id('y'));
    |                  ^^^^^^^ - temporary value is freed at the end of this statement
@@ -41,7 +44,7 @@ LL |         v4.use_ref();
    = note: consider using a `let` binding to create a longer lived value
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/borrowck-let-suggestion-suffixes.rs:40:14
+  --> $DIR/borrowck-let-suggestion-suffixes.rs:41:14
    |
 LL |     v5.push(&id('z'));
    |              ^^^^^^^ - temporary value is freed at the end of this statement
diff --git a/tests/ui/span/destructor-restrictions.stderr b/tests/ui/span/destructor-restrictions.stderr
index 53c9404620f..281248626c8 100644
--- a/tests/ui/span/destructor-restrictions.stderr
+++ b/tests/ui/span/destructor-restrictions.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `*a` does not live long enough
   --> $DIR/destructor-restrictions.rs:8:10
    |
+LL |         let a = Box::new(RefCell::new(4));
+   |             - binding `a` declared here
 LL |         *a.borrow() + 1
    |          ^^^^^^^^^^
    |          |
diff --git a/tests/ui/span/dropck-object-cycle.stderr b/tests/ui/span/dropck-object-cycle.stderr
index 229d17e1cf9..097fb6219f1 100644
--- a/tests/ui/span/dropck-object-cycle.stderr
+++ b/tests/ui/span/dropck-object-cycle.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `*m` does not live long enough
   --> $DIR/dropck-object-cycle.rs:27:31
    |
+LL |     let m : Box<dyn Trait+'static> = make_val();
+   |         - binding `m` declared here
 LL |     assert_eq!(object_invoke1(&*m), (4,5));
    |                               ^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/dropck_arr_cycle_checked.stderr b/tests/ui/span/dropck_arr_cycle_checked.stderr
index 068c779ae52..23ebc8d598c 100644
--- a/tests/ui/span/dropck_arr_cycle_checked.stderr
+++ b/tests/ui/span/dropck_arr_cycle_checked.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `b2` does not live long enough
   --> $DIR/dropck_arr_cycle_checked.rs:93:24
    |
+LL |     let (b1, b2, b3);
+   |              -- binding `b2` declared here
+...
 LL |     b1.a[0].v.set(Some(&b2));
    |                        ^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL | }
 error[E0597]: `b3` does not live long enough
   --> $DIR/dropck_arr_cycle_checked.rs:95:24
    |
+LL |     let (b1, b2, b3);
+   |                  -- binding `b3` declared here
+...
 LL |     b1.a[1].v.set(Some(&b3));
    |                        ^^^ borrowed value does not live long enough
 ...
@@ -29,6 +35,9 @@ LL | }
 error[E0597]: `b1` does not live long enough
   --> $DIR/dropck_arr_cycle_checked.rs:99:24
    |
+LL |     let (b1, b2, b3);
+   |          -- binding `b1` declared here
+...
 LL |     b3.a[0].v.set(Some(&b1));
    |                        ^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/dropck_direct_cycle_with_drop.stderr b/tests/ui/span/dropck_direct_cycle_with_drop.stderr
index 07ae138ac71..1e75e3b2fa1 100644
--- a/tests/ui/span/dropck_direct_cycle_with_drop.stderr
+++ b/tests/ui/span/dropck_direct_cycle_with_drop.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `d2` does not live long enough
   --> $DIR/dropck_direct_cycle_with_drop.rs:36:19
    |
+LL |     let (d1, d2) = (D::new(format!("d1")), D::new(format!("d2")));
+   |              -- binding `d2` declared here
 LL |     d1.p.set(Some(&d2));
    |                   ^^^ borrowed value does not live long enough
 ...
@@ -15,6 +17,9 @@ LL | }
 error[E0597]: `d1` does not live long enough
   --> $DIR/dropck_direct_cycle_with_drop.rs:38:19
    |
+LL |     let (d1, d2) = (D::new(format!("d1")), D::new(format!("d2")));
+   |          -- binding `d1` declared here
+...
 LL |     d2.p.set(Some(&d1));
    |                   ^^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/span/dropck_misc_variants.stderr b/tests/ui/span/dropck_misc_variants.stderr
index 76e90574cef..24a2c9089f5 100644
--- a/tests/ui/span/dropck_misc_variants.stderr
+++ b/tests/ui/span/dropck_misc_variants.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `bomb` does not live long enough
   --> $DIR/dropck_misc_variants.rs:23:36
    |
+LL |     let (_w, bomb);
+   |              ---- binding `bomb` declared here
+LL |     bomb = vec![""];
 LL |     _w = Wrap::<&[&str]>(NoisyDrop(&bomb));
    |                                    ^^^^^ borrowed value does not live long enough
 LL | }
@@ -14,6 +17,9 @@ LL | }
 error[E0597]: `v` does not live long enough
   --> $DIR/dropck_misc_variants.rs:31:27
    |
+LL |     let (_w,v);
+   |             - binding `v` declared here
+...
 LL |         let u = NoisyDrop(&v);
    |                           ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/dropck_vec_cycle_checked.stderr b/tests/ui/span/dropck_vec_cycle_checked.stderr
index 7ff991c0c37..5817439c0d8 100644
--- a/tests/ui/span/dropck_vec_cycle_checked.stderr
+++ b/tests/ui/span/dropck_vec_cycle_checked.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c2` does not live long enough
   --> $DIR/dropck_vec_cycle_checked.rs:98:24
    |
+LL |     let (mut c1, mut c2, mut c3);
+   |                  ------ binding `c2` declared here
+...
 LL |     c1.v[0].v.set(Some(&c2));
    |                        ^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL | }
 error[E0597]: `c3` does not live long enough
   --> $DIR/dropck_vec_cycle_checked.rs:100:24
    |
+LL |     let (mut c1, mut c2, mut c3);
+   |                          ------ binding `c3` declared here
+...
 LL |     c1.v[1].v.set(Some(&c3));
    |                        ^^^ borrowed value does not live long enough
 ...
@@ -29,6 +35,9 @@ LL | }
 error[E0597]: `c1` does not live long enough
   --> $DIR/dropck_vec_cycle_checked.rs:104:24
    |
+LL |     let (mut c1, mut c2, mut c3);
+   |          ------ binding `c1` declared here
+...
 LL |     c3.v[0].v.set(Some(&c1));
    |                        ^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue-23338-locals-die-before-temps-of-body.stderr b/tests/ui/span/issue-23338-locals-die-before-temps-of-body.stderr
index 3c2022748f0..e1a377203e2 100644
--- a/tests/ui/span/issue-23338-locals-die-before-temps-of-body.stderr
+++ b/tests/ui/span/issue-23338-locals-die-before-temps-of-body.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `y` does not live long enough
   --> $DIR/issue-23338-locals-die-before-temps-of-body.rs:10:5
    |
+LL |     let y = x;
+   |         - binding `y` declared here
 LL |     y.borrow().clone()
    |     ^^^^^^^^^^
    |     |
@@ -22,6 +24,8 @@ LL |     let x = y.borrow().clone(); x
 error[E0597]: `y` does not live long enough
   --> $DIR/issue-23338-locals-die-before-temps-of-body.rs:17:9
    |
+LL |         let y = x;
+   |             - binding `y` declared here
 LL |         y.borrow().clone()
    |         ^^^^^^^^^^
    |         |
diff --git a/tests/ui/span/issue-24805-dropck-child-has-items-via-parent.stderr b/tests/ui/span/issue-24805-dropck-child-has-items-via-parent.stderr
index 809e60a8c8a..c3b6d7580b4 100644
--- a/tests/ui/span/issue-24805-dropck-child-has-items-via-parent.stderr
+++ b/tests/ui/span/issue-24805-dropck-child-has-items-via-parent.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `d1` does not live long enough
   --> $DIR/issue-24805-dropck-child-has-items-via-parent.rs:28:18
    |
+LL |     let (_d, d1);
+   |              -- binding `d1` declared here
+...
 LL |     _d = D_Child(&d1);
    |                  ^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue-24805-dropck-trait-has-items.stderr b/tests/ui/span/issue-24805-dropck-trait-has-items.stderr
index 2e217066915..e52c57d9ab1 100644
--- a/tests/ui/span/issue-24805-dropck-trait-has-items.stderr
+++ b/tests/ui/span/issue-24805-dropck-trait-has-items.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `d1` does not live long enough
   --> $DIR/issue-24805-dropck-trait-has-items.rs:37:26
    |
+LL |     let (_d, d1);
+   |              -- binding `d1` declared here
+LL |     d1 = D_HasSelfMethod(1);
 LL |     _d = D_HasSelfMethod(&d1);
    |                          ^^^ borrowed value does not live long enough
 LL | }
@@ -14,6 +17,9 @@ LL | }
 error[E0597]: `d1` does not live long enough
   --> $DIR/issue-24805-dropck-trait-has-items.rs:43:33
    |
+LL |     let (_d, d1);
+   |              -- binding `d1` declared here
+LL |     d1 = D_HasMethodWithSelfArg(1);
 LL |     _d = D_HasMethodWithSelfArg(&d1);
    |                                 ^^^ borrowed value does not live long enough
 LL | }
@@ -27,6 +33,9 @@ LL | }
 error[E0597]: `d1` does not live long enough
   --> $DIR/issue-24805-dropck-trait-has-items.rs:49:20
    |
+LL |     let (_d, d1);
+   |              -- binding `d1` declared here
+LL |     d1 = D_HasType(1);
 LL |     _d = D_HasType(&d1);
    |                    ^^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui/span/issue-24895-copy-clone-dropck.stderr b/tests/ui/span/issue-24895-copy-clone-dropck.stderr
index 18a3dc9e6de..83db4d509d4 100644
--- a/tests/ui/span/issue-24895-copy-clone-dropck.stderr
+++ b/tests/ui/span/issue-24895-copy-clone-dropck.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `d1` does not live long enough
   --> $DIR/issue-24895-copy-clone-dropck.rs:27:14
    |
+LL |     let (d2, d1);
+   |              -- binding `d1` declared here
+LL |     d1 = D(34, "d1");
 LL |     d2 = D(S(&d1, "inner"), "d2");
    |              ^^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui/span/issue-25199.stderr b/tests/ui/span/issue-25199.stderr
index d70a4afc1bf..1e0276f0c36 100644
--- a/tests/ui/span/issue-25199.stderr
+++ b/tests/ui/span/issue-25199.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `container` does not live long enough
   --> $DIR/issue-25199.rs:70:27
    |
+LL |     let container = Container::new();
+   |         --------- binding `container` declared here
 LL |     let test = Test{test: &container};
    |                           ^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue-26656.stderr b/tests/ui/span/issue-26656.stderr
index 1e939c484fb..fea6e001238 100644
--- a/tests/ui/span/issue-26656.stderr
+++ b/tests/ui/span/issue-26656.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `ticking` does not live long enough
   --> $DIR/issue-26656.rs:40:35
    |
+LL |     let (mut zook, ticking);
+   |                    ------- binding `ticking` declared here
+...
 LL |     zook.button = B::BigRedButton(&ticking);
    |                                   ^^^^^^^^ borrowed value does not live long enough
 LL | }
diff --git a/tests/ui/span/issue-29106.stderr b/tests/ui/span/issue-29106.stderr
index 71fbd60ee73..28ee7acd90e 100644
--- a/tests/ui/span/issue-29106.stderr
+++ b/tests/ui/span/issue-29106.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/issue-29106.rs:16:26
    |
+LL |         let (y, x);
+   |                 - binding `x` declared here
+LL |         x = "alive".to_string();
 LL |         y = Arc::new(Foo(&x));
    |                          ^^ borrowed value does not live long enough
 LL |     }
@@ -14,6 +17,9 @@ LL |     }
 error[E0597]: `x` does not live long enough
   --> $DIR/issue-29106.rs:23:25
    |
+LL |         let (y, x);
+   |                 - binding `x` declared here
+LL |         x = "alive".to_string();
 LL |         y = Rc::new(Foo(&x));
    |                         ^^ borrowed value does not live long enough
 LL |     }
diff --git a/tests/ui/span/issue-36537.stderr b/tests/ui/span/issue-36537.stderr
index 79a0ebaeb8d..6c330c1a094 100644
--- a/tests/ui/span/issue-36537.stderr
+++ b/tests/ui/span/issue-36537.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/issue-36537.rs:5:13
    |
+LL |         let a = 42;
+   |             - binding `a` declared here
 LL |         p = &a;
    |             ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue-40157.stderr b/tests/ui/span/issue-40157.stderr
index 57f80214a4f..a0afd33f7c7 100644
--- a/tests/ui/span/issue-40157.stderr
+++ b/tests/ui/span/issue-40157.stderr
@@ -2,11 +2,10 @@ error[E0597]: `foo` does not live long enough
   --> $DIR/issue-40157.rs:2:53
    |
 LL |     {println!("{:?}", match { let foo = vec![1, 2]; foo.get(1) } { x => x });}
-   |                             ------------------------^^^^^^^^^^--
-   |                             |                       |          |
-   |                             |                       |          `foo` dropped here while still borrowed
-   |                             |                       borrowed value does not live long enough
-   |                             borrow later used here
+   |                                   ---               ^^^^^^^^^^ - `foo` dropped here while still borrowed
+   |                                   |                 |
+   |                                   |                 borrowed value does not live long enough
+   |                                   binding `foo` declared here
 
 error: aborting due to previous error
 
diff --git a/tests/ui/span/issue28498-reject-lifetime-param.stderr b/tests/ui/span/issue28498-reject-lifetime-param.stderr
index 3119ddd03cc..94c450c7b1e 100644
--- a/tests/ui/span/issue28498-reject-lifetime-param.stderr
+++ b/tests/ui/span/issue28498-reject-lifetime-param.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `first_dropped` does not live long enough
   --> $DIR/issue28498-reject-lifetime-param.rs:32:19
    |
+LL |     let (foo1, first_dropped);
+   |                ------------- binding `first_dropped` declared here
+...
 LL |     foo1 = Foo(1, &first_dropped);
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue28498-reject-passed-to-fn.stderr b/tests/ui/span/issue28498-reject-passed-to-fn.stderr
index 60e8a648cd5..e133f75d57b 100644
--- a/tests/ui/span/issue28498-reject-passed-to-fn.stderr
+++ b/tests/ui/span/issue28498-reject-passed-to-fn.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `first_dropped` does not live long enough
   --> $DIR/issue28498-reject-passed-to-fn.rs:34:19
    |
+LL |     let (foo1, first_dropped);
+   |                ------------- binding `first_dropped` declared here
+...
 LL |     foo1 = Foo(1, &first_dropped, Box::new(callback));
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/issue28498-reject-trait-bound.stderr b/tests/ui/span/issue28498-reject-trait-bound.stderr
index 22e4a8205b6..9ab3cdd1343 100644
--- a/tests/ui/span/issue28498-reject-trait-bound.stderr
+++ b/tests/ui/span/issue28498-reject-trait-bound.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `first_dropped` does not live long enough
   --> $DIR/issue28498-reject-trait-bound.rs:34:19
    |
+LL |     let (foo1, first_dropped);
+   |                ------------- binding `first_dropped` declared here
+...
 LL |     foo1 = Foo(1, &first_dropped);
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/mut-ptr-cant-outlive-ref.stderr b/tests/ui/span/mut-ptr-cant-outlive-ref.stderr
index 4d976a7bbfa..be56f9489c7 100644
--- a/tests/ui/span/mut-ptr-cant-outlive-ref.stderr
+++ b/tests/ui/span/mut-ptr-cant-outlive-ref.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `b` does not live long enough
   --> $DIR/mut-ptr-cant-outlive-ref.rs:8:15
    |
+LL |         let b = m.borrow();
+   |             - binding `b` declared here
 LL |         p = &*b;
    |               ^ borrowed value does not live long enough
 LL |     }
diff --git a/tests/ui/span/range-2.stderr b/tests/ui/span/range-2.stderr
index 8ca8156b083..d7084b00ba4 100644
--- a/tests/ui/span/range-2.stderr
+++ b/tests/ui/span/range-2.stderr
@@ -3,7 +3,9 @@ error[E0597]: `a` does not live long enough
    |
 LL |     let r = {
    |         - borrow later stored here
-...
+LL |         let a = 42;
+   |             - binding `a` declared here
+LL |         let b = 42;
 LL |         &a..&b
    |         ^^ borrowed value does not live long enough
 LL |     };
@@ -14,7 +16,9 @@ error[E0597]: `b` does not live long enough
    |
 LL |     let r = {
    |         - borrow later stored here
-...
+LL |         let a = 42;
+LL |         let b = 42;
+   |             - binding `b` declared here
 LL |         &a..&b
    |             ^^ borrowed value does not live long enough
 LL |     };
diff --git a/tests/ui/span/regionck-unboxed-closure-lifetimes.stderr b/tests/ui/span/regionck-unboxed-closure-lifetimes.stderr
index 0b985de609c..fb3fad6ae90 100644
--- a/tests/ui/span/regionck-unboxed-closure-lifetimes.stderr
+++ b/tests/ui/span/regionck-unboxed-closure-lifetimes.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `c` does not live long enough
   --> $DIR/regionck-unboxed-closure-lifetimes.rs:8:21
    |
+LL |         let c = 1;
+   |             - binding `c` declared here
 LL |         let c_ref = &c;
    |                     ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/regions-close-over-type-parameter-2.stderr b/tests/ui/span/regions-close-over-type-parameter-2.stderr
index 2e584d9a884..fed40a4fdd2 100644
--- a/tests/ui/span/regions-close-over-type-parameter-2.stderr
+++ b/tests/ui/span/regions-close-over-type-parameter-2.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `tmp0` does not live long enough
   --> $DIR/regions-close-over-type-parameter-2.rs:23:20
    |
+LL |         let tmp0 = 3;
+   |             ---- binding `tmp0` declared here
 LL |         let tmp1 = &tmp0;
    |                    ^^^^^ borrowed value does not live long enough
 LL |         repeater3(tmp1)
diff --git a/tests/ui/span/regions-escape-loop-via-variable.stderr b/tests/ui/span/regions-escape-loop-via-variable.stderr
index 42df6685297..e5c7d8b26ab 100644
--- a/tests/ui/span/regions-escape-loop-via-variable.stderr
+++ b/tests/ui/span/regions-escape-loop-via-variable.stderr
@@ -2,7 +2,9 @@ error[E0597]: `x` does not live long enough
   --> $DIR/regions-escape-loop-via-variable.rs:11:13
    |
 LL |         let x = 1 + *p;
-   |                     -- borrow later used here
+   |             -       -- borrow later used here
+   |             |
+   |             binding `x` declared here
 LL |         p = &x;
    |             ^^ borrowed value does not live long enough
 LL |     }
diff --git a/tests/ui/span/regions-escape-loop-via-vec.stderr b/tests/ui/span/regions-escape-loop-via-vec.stderr
index 2b649307739..532ac3606c5 100644
--- a/tests/ui/span/regions-escape-loop-via-vec.stderr
+++ b/tests/ui/span/regions-escape-loop-via-vec.stderr
@@ -2,7 +2,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/regions-escape-loop-via-vec.rs:5:11
    |
 LL |     let mut _y = vec![&mut x];
-   |                       ------ borrow of `x` occurs here
+   |                       ------ `x` is borrowed here
 LL |     while x < 10 {
    |           ^ use of borrowed `x`
 LL |         let mut z = x;
@@ -13,7 +13,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/regions-escape-loop-via-vec.rs:6:21
    |
 LL |     let mut _y = vec![&mut x];
-   |                       ------ borrow of `x` occurs here
+   |                       ------ `x` is borrowed here
 LL |     while x < 10 {
 LL |         let mut z = x;
    |                     ^ use of borrowed `x`
@@ -23,11 +23,10 @@ LL |         _y.push(&mut z);
 error[E0597]: `z` does not live long enough
   --> $DIR/regions-escape-loop-via-vec.rs:7:17
    |
+LL |         let mut z = x;
+   |             ----- binding `z` declared here
 LL |         _y.push(&mut z);
-   |         --------^^^^^^-
-   |         |       |
-   |         |       borrowed value does not live long enough
-   |         borrow later used here
+   |                 ^^^^^^ borrowed value does not live long enough
 ...
 LL |     }
    |     - `z` dropped here while still borrowed
@@ -36,7 +35,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
   --> $DIR/regions-escape-loop-via-vec.rs:9:9
    |
 LL |     let mut _y = vec![&mut x];
-   |                       ------ borrow of `x` occurs here
+   |                       ------ `x` is borrowed here
 ...
 LL |         _y.push(&mut z);
    |         --------------- borrow later used here
diff --git a/tests/ui/span/regions-infer-borrow-scope-within-loop.stderr b/tests/ui/span/regions-infer-borrow-scope-within-loop.stderr
index fd67c65c4e9..47931db84ca 100644
--- a/tests/ui/span/regions-infer-borrow-scope-within-loop.stderr
+++ b/tests/ui/span/regions-infer-borrow-scope-within-loop.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `*x` does not live long enough
   --> $DIR/regions-infer-borrow-scope-within-loop.rs:13:20
    |
+LL |         let x = make_box();
+   |             - binding `x` declared here
+...
 LL |         y = borrow(&*x);
    |                    ^^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/send-is-not-static-ensures-scoping.stderr b/tests/ui/span/send-is-not-static-ensures-scoping.stderr
index 65d10c1305b..bae0befcaca 100644
--- a/tests/ui/span/send-is-not-static-ensures-scoping.stderr
+++ b/tests/ui/span/send-is-not-static-ensures-scoping.stderr
@@ -4,6 +4,7 @@ error[E0597]: `x` does not live long enough
 LL |     let bad = {
    |         --- borrow later stored here
 LL |         let x = 1;
+   |             - binding `x` declared here
 LL |         let y = &x;
    |                 ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/send-is-not-static-std-sync-2.stderr b/tests/ui/span/send-is-not-static-std-sync-2.stderr
index bcd07e11647..b0267fa6f43 100644
--- a/tests/ui/span/send-is-not-static-std-sync-2.stderr
+++ b/tests/ui/span/send-is-not-static-std-sync-2.stderr
@@ -4,6 +4,7 @@ error[E0597]: `x` does not live long enough
 LL |     let lock = {
    |         ---- borrow later stored here
 LL |         let x = 1;
+   |             - binding `x` declared here
 LL |         Mutex::new(&x)
    |                    ^^ borrowed value does not live long enough
 LL |     };
@@ -15,6 +16,7 @@ error[E0597]: `x` does not live long enough
 LL |     let lock = {
    |         ---- borrow later stored here
 LL |         let x = 1;
+   |             - binding `x` declared here
 LL |         RwLock::new(&x)
    |                     ^^ borrowed value does not live long enough
 LL |     };
@@ -25,7 +27,9 @@ error[E0597]: `x` does not live long enough
    |
 LL |     let (_tx, rx) = {
    |          --- borrow later used here
-...
+LL |         let x = 1;
+   |             - binding `x` declared here
+LL |         let (tx, rx) = mpsc::channel();
 LL |         let _ = tx.send(&x);
    |                         ^^ borrowed value does not live long enough
 LL |         (tx, rx)
diff --git a/tests/ui/span/send-is-not-static-std-sync.stderr b/tests/ui/span/send-is-not-static-std-sync.stderr
index 5d493a3e4ee..7dfe94bca60 100644
--- a/tests/ui/span/send-is-not-static-std-sync.stderr
+++ b/tests/ui/span/send-is-not-static-std-sync.stderr
@@ -1,6 +1,9 @@
 error[E0505]: cannot move out of `y` because it is borrowed
   --> $DIR/send-is-not-static-std-sync.rs:13:10
    |
+LL |     let y = Box::new(1);
+   |         - binding `y` declared here
+LL |     let lock = Mutex::new(&x);
 LL |     *lock.lock().unwrap() = &*y;
    |                             --- borrow of `*y` occurs here
 LL |     drop(y);
@@ -12,6 +15,8 @@ LL |         *lock.lock().unwrap() = &z;
 error[E0597]: `z` does not live long enough
   --> $DIR/send-is-not-static-std-sync.rs:16:33
    |
+LL |         let z = 2;
+   |             - binding `z` declared here
 LL |         *lock.lock().unwrap() = &z;
    |                                 ^^ borrowed value does not live long enough
 LL |     }
@@ -23,6 +28,9 @@ LL |     lock.use_ref(); // (Mutex is #[may_dangle] so its dtor does not use `z`
 error[E0505]: cannot move out of `y` because it is borrowed
   --> $DIR/send-is-not-static-std-sync.rs:27:10
    |
+LL |     let y = Box::new(1);
+   |         - binding `y` declared here
+LL |     let lock = RwLock::new(&x);
 LL |     *lock.write().unwrap() = &*y;
    |                              --- borrow of `*y` occurs here
 LL |     drop(y);
@@ -34,6 +42,8 @@ LL |         *lock.write().unwrap() = &z;
 error[E0597]: `z` does not live long enough
   --> $DIR/send-is-not-static-std-sync.rs:30:34
    |
+LL |         let z = 2;
+   |             - binding `z` declared here
 LL |         *lock.write().unwrap() = &z;
    |                                  ^^ borrowed value does not live long enough
 LL |     }
@@ -45,6 +55,9 @@ LL |     lock.use_ref(); // (RwLock is #[may_dangle] so its dtor does not use `z
 error[E0505]: cannot move out of `y` because it is borrowed
   --> $DIR/send-is-not-static-std-sync.rs:43:10
    |
+LL |     let y = Box::new(1);
+   |         - binding `y` declared here
+...
 LL |     tx.send(&*y);
    |             --- borrow of `*y` occurs here
 LL |     drop(y);
@@ -56,6 +69,8 @@ LL |         tx.send(&z).unwrap();
 error[E0597]: `z` does not live long enough
   --> $DIR/send-is-not-static-std-sync.rs:46:17
    |
+LL |         let z = 2;
+   |             - binding `z` declared here
 LL |         tx.send(&z).unwrap();
    |                 ^^ borrowed value does not live long enough
 LL |     }
diff --git a/tests/ui/span/vec-must-not-hide-type-from-dropck.stderr b/tests/ui/span/vec-must-not-hide-type-from-dropck.stderr
index f87c32d1ad0..f2fefca414e 100644
--- a/tests/ui/span/vec-must-not-hide-type-from-dropck.stderr
+++ b/tests/ui/span/vec-must-not-hide-type-from-dropck.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `c2` does not live long enough
   --> $DIR/vec-must-not-hide-type-from-dropck.rs:117:24
    |
+LL |     let (mut c1, mut c2);
+   |                  ------ binding `c2` declared here
+...
 LL |     c1.v[0].v.set(Some(&c2));
    |                        ^^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL | }
 error[E0597]: `c1` does not live long enough
   --> $DIR/vec-must-not-hide-type-from-dropck.rs:119:24
    |
+LL |     let (mut c1, mut c2);
+   |          ------ binding `c1` declared here
+...
 LL |     c2.v[0].v.set(Some(&c1));
    |                        ^^^ borrowed value does not live long enough
 LL |
diff --git a/tests/ui/span/vec_refs_data_with_early_death.stderr b/tests/ui/span/vec_refs_data_with_early_death.stderr
index 684e7845313..73f27144af4 100644
--- a/tests/ui/span/vec_refs_data_with_early_death.stderr
+++ b/tests/ui/span/vec_refs_data_with_early_death.stderr
@@ -1,6 +1,9 @@
 error[E0597]: `x` does not live long enough
   --> $DIR/vec_refs_data_with_early_death.rs:17:12
    |
+LL |     let x: i8 = 3;
+   |         - binding `x` declared here
+...
 LL |     v.push(&x);
    |            ^^ borrowed value does not live long enough
 ...
@@ -15,6 +18,9 @@ LL | }
 error[E0597]: `y` does not live long enough
   --> $DIR/vec_refs_data_with_early_death.rs:19:12
    |
+LL |     let y: i8 = 4;
+   |         - binding `y` declared here
+...
 LL |     v.push(&y);
    |            ^^ borrowed value does not live long enough
 ...
diff --git a/tests/ui/span/wf-method-late-bound-regions.stderr b/tests/ui/span/wf-method-late-bound-regions.stderr
index 6b0b008208f..64c2d0f1606 100644
--- a/tests/ui/span/wf-method-late-bound-regions.stderr
+++ b/tests/ui/span/wf-method-late-bound-regions.stderr
@@ -4,6 +4,7 @@ error[E0597]: `pointer` does not live long enough
 LL |     let dangling = {
    |         -------- borrow later stored here
 LL |         let pointer = Box::new(42);
+   |             ------- binding `pointer` declared here
 LL |         f2.xmute(&pointer)
    |                  ^^^^^^^^ borrowed value does not live long enough
 LL |     };
diff --git a/tests/ui/static/static-lifetime-bound.stderr b/tests/ui/static/static-lifetime-bound.stderr
index ef07a89315f..e22411b13b7 100644
--- a/tests/ui/static/static-lifetime-bound.stderr
+++ b/tests/ui/static/static-lifetime-bound.stderr
@@ -9,6 +9,8 @@ LL | fn f<'a: 'static>(_: &'a i32) {}
 error[E0597]: `x` does not live long enough
   --> $DIR/static-lifetime-bound.rs:5:7
    |
+LL |     let x = 0;
+   |         - binding `x` declared here
 LL |     f(&x);
    |     --^^-
    |     | |
diff --git a/tests/ui/static/static-reference-to-fn-1.stderr b/tests/ui/static/static-reference-to-fn-1.stderr
index 67b478bdb75..f68939d0ec8 100644
--- a/tests/ui/static/static-reference-to-fn-1.stderr
+++ b/tests/ui/static/static-reference-to-fn-1.stderr
@@ -2,10 +2,14 @@ error[E0308]: mismatched types
   --> $DIR/static-reference-to-fn-1.rs:17:15
    |
 LL |         func: &foo,
-   |               ^^^^ expected fn pointer, found fn item
+   |               ^^^^
+   |               |
+   |               expected fn pointer, found fn item
+   |               help: consider casting to a fn pointer: `&(foo as fn() -> Option<isize>)`
    |
    = note: expected reference `&fn() -> Option<isize>`
               found reference `&fn() -> Option<isize> {foo}`
+   = note: fn items are distinct from fn pointers
 
 error: aborting due to previous error
 
diff --git a/tests/ui/stdlib-unit-tests/not-sync.stderr b/tests/ui/stdlib-unit-tests/not-sync.stderr
index 1ee358ba836..4e34e10e377 100644
--- a/tests/ui/stdlib-unit-tests/not-sync.stderr
+++ b/tests/ui/stdlib-unit-tests/not-sync.stderr
@@ -5,6 +5,7 @@ LL |     test::<Cell<i32>>();
    |            ^^^^^^^^^ `Cell<i32>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `Cell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead
 note: required by a bound in `test`
   --> $DIR/not-sync.rs:5:12
    |
@@ -18,6 +19,7 @@ LL |     test::<RefCell<i32>>();
    |            ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: required by a bound in `test`
   --> $DIR/not-sync.rs:5:12
    |
diff --git a/tests/ui/suggestions/assoc-const-without-self.rs b/tests/ui/suggestions/assoc-const-without-self.rs
new file mode 100644
index 00000000000..95070ec601c
--- /dev/null
+++ b/tests/ui/suggestions/assoc-const-without-self.rs
@@ -0,0 +1,11 @@
+struct Foo;
+
+impl Foo {
+    const A_CONST: usize = 1;
+
+    fn foo() -> usize {
+        A_CONST //~ ERROR cannot find value `A_CONST` in this scope
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/suggestions/assoc-const-without-self.stderr b/tests/ui/suggestions/assoc-const-without-self.stderr
new file mode 100644
index 00000000000..88d72da70cb
--- /dev/null
+++ b/tests/ui/suggestions/assoc-const-without-self.stderr
@@ -0,0 +1,14 @@
+error[E0425]: cannot find value `A_CONST` in this scope
+  --> $DIR/assoc-const-without-self.rs:7:9
+   |
+LL |         A_CONST
+   |         ^^^^^^^ not found in this scope
+   |
+help: consider using the associated constant
+   |
+LL |         Self::A_CONST
+   |         ++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/suggestions/borrow-for-loop-head.stderr b/tests/ui/suggestions/borrow-for-loop-head.stderr
index cbdb94877bd..0f179438a12 100644
--- a/tests/ui/suggestions/borrow-for-loop-head.stderr
+++ b/tests/ui/suggestions/borrow-for-loop-head.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/borrow-for-loop-head.rs:4:18
    |
+LL |     let a = vec![1, 2, 3];
+   |         - binding `a` declared here
 LL |     for i in &a {
    |              -- borrow of `a` occurs here
 LL |         for j in a {
diff --git a/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.rs b/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.rs
new file mode 100644
index 00000000000..3bf6b7bb9b1
--- /dev/null
+++ b/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.rs
@@ -0,0 +1,28 @@
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::rc::Rc;
+
+pub struct Trader<'a> {
+    closure: Box<dyn Fn(&mut Trader) + 'a>,
+}
+
+impl<'a> Trader<'a> {
+    pub fn new() -> Self {
+        Trader {
+            closure: Box::new(|_| {}),
+        }
+    }
+    pub fn set_closure(&mut self, function: impl Fn(&mut Trader) + 'a) {
+        //foo
+    }
+}
+
+fn main() {
+    let closure = |trader : Trader| {
+        println!("Woooosh!");
+    };
+
+    let mut trader = Trader::new();
+    trader.set_closure(closure);
+    //~^ ERROR type mismatch in closure arguments
+}
diff --git a/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.stderr b/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.stderr
new file mode 100644
index 00000000000..6820af1fd45
--- /dev/null
+++ b/tests/ui/suggestions/late-bound-in-borrow-closure-sugg.stderr
@@ -0,0 +1,26 @@
+error[E0631]: type mismatch in closure arguments
+  --> $DIR/late-bound-in-borrow-closure-sugg.rs:26:24
+   |
+LL |     let closure = |trader : Trader| {
+   |                   ----------------- found signature defined here
+...
+LL |     trader.set_closure(closure);
+   |            ----------- ^^^^^^^ expected due to this
+   |            |
+   |            required by a bound introduced by this call
+   |
+   = note: expected closure signature `for<'a, 'b> fn(&'a mut Trader<'b>) -> _`
+              found closure signature `for<'a> fn(Trader<'a>) -> _`
+note: required by a bound in `Trader::<'a>::set_closure`
+  --> $DIR/late-bound-in-borrow-closure-sugg.rs:15:50
+   |
+LL |     pub fn set_closure(&mut self, function: impl Fn(&mut Trader) + 'a) {
+   |                                                  ^^^^^^^^^^^^^^^ required by this bound in `Trader::<'a>::set_closure`
+help: consider borrowing the argument
+   |
+LL |     let closure = |trader : &mut Trader| {
+   |                             ++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0631`.
diff --git a/tests/ui/suggestions/option-content-move2.stderr b/tests/ui/suggestions/option-content-move2.stderr
index 1d3dff3be34..94acda73c4e 100644
--- a/tests/ui/suggestions/option-content-move2.stderr
+++ b/tests/ui/suggestions/option-content-move2.stderr
@@ -7,7 +7,7 @@ LL |     func(|| {
    |          -- captured by this `FnMut` closure
 LL |         // Shouldn't suggest `move ||.as_ref()` here
 LL |         move || {
-   |         ^^^^^^^ move out of `var` occurs here
+   |         ^^^^^^^ `var` is moved here
 LL |
 LL |             var = Some(NotCopyable);
    |             ---
diff --git a/tests/ui/suggestions/ref-pattern-binding.stderr b/tests/ui/suggestions/ref-pattern-binding.stderr
index 10447ba7089..7b194259349 100644
--- a/tests/ui/suggestions/ref-pattern-binding.stderr
+++ b/tests/ui/suggestions/ref-pattern-binding.stderr
@@ -19,8 +19,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref _moved @ _from = String::from("foo");
    |         ----------^^^-----
    |         |            |
-   |         |            value moved into `_from` here
-   |         value borrowed, by `_moved`, here
+   |         |            value is moved into `_from` here
+   |         value is borrowed by `_moved` here
 
 error: cannot move out of value because it is borrowed
   --> $DIR/ref-pattern-binding.rs:15:9
@@ -28,8 +28,8 @@ error: cannot move out of value because it is borrowed
 LL |     let ref _moved @ S { f } = S { f: String::from("foo") };
    |         ----------^^^^^^^-^^
    |         |                |
-   |         |                value moved into `f` here
-   |         value borrowed, by `_moved`, here
+   |         |                value is moved into `f` here
+   |         value is borrowed by `_moved` here
 
 error: borrow of moved value
   --> $DIR/ref-pattern-binding.rs:18:9
diff --git a/tests/ui/symbol-names/basic.legacy.stderr b/tests/ui/symbol-names/basic.legacy.stderr
index 3ad4ed24cf7..fe490a6000d 100644
--- a/tests/ui/symbol-names/basic.legacy.stderr
+++ b/tests/ui/symbol-names/basic.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN5basic4main17hcbad207c0eeb0b3bE)
+error: symbol-name(_ZN5basic4main17he9f658e438f1cac0E)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(basic::main::hcbad207c0eeb0b3b)
+error: demangling(basic::main::he9f658e438f1cac0)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
diff --git a/tests/ui/symbol-names/issue-60925.legacy.stderr b/tests/ui/symbol-names/issue-60925.legacy.stderr
index 21bf21ee71c..29b42f48d80 100644
--- a/tests/ui/symbol-names/issue-60925.legacy.stderr
+++ b/tests/ui/symbol-names/issue-60925.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17h2f2efcf580c9b1eeE)
+error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17h13209029be24b923E)
   --> $DIR/issue-60925.rs:21:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::h2f2efcf580c9b1ee)
+error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::h13209029be24b923)
   --> $DIR/issue-60925.rs:21:9
    |
 LL |         #[rustc_symbol_name]
diff --git a/tests/ui/mutexguard-sync.rs b/tests/ui/sync/mutexguard-sync.rs
index b5641838318..b5641838318 100644
--- a/tests/ui/mutexguard-sync.rs
+++ b/tests/ui/sync/mutexguard-sync.rs
diff --git a/tests/ui/mutexguard-sync.stderr b/tests/ui/sync/mutexguard-sync.stderr
index 3fbb2ddf183..4dc5571196c 100644
--- a/tests/ui/mutexguard-sync.stderr
+++ b/tests/ui/sync/mutexguard-sync.stderr
@@ -7,6 +7,7 @@ LL |     test_sync(guard);
    |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `Cell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead
    = note: required for `MutexGuard<'_, Cell<i32>>` to implement `Sync`
 note: required by a bound in `test_sync`
   --> $DIR/mutexguard-sync.rs:5:17
diff --git a/tests/ui/sync/suggest-cell.rs b/tests/ui/sync/suggest-cell.rs
new file mode 100644
index 00000000000..3284eae7be1
--- /dev/null
+++ b/tests/ui/sync/suggest-cell.rs
@@ -0,0 +1,31 @@
+fn require_sync<T: Sync>() {}
+//~^ NOTE required by this bound in `require_sync`
+//~| NOTE required by this bound in `require_sync`
+//~| NOTE required by this bound in `require_sync`
+//~| NOTE required by this bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+
+fn main() {
+    require_sync::<std::cell::Cell<()>>();
+    //~^ ERROR `Cell<()>` cannot be shared between threads safely
+    //~| NOTE `Cell<()>` cannot be shared between threads safely
+    //~| NOTE if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock`
+
+    require_sync::<std::cell::Cell<u8>>();
+    //~^ ERROR `Cell<u8>` cannot be shared between threads safely
+    //~| NOTE `Cell<u8>` cannot be shared between threads safely
+    //~| NOTE if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU8` instead
+
+    require_sync::<std::cell::Cell<i32>>();
+    //~^ ERROR `Cell<i32>` cannot be shared between threads safely
+    //~| NOTE `Cell<i32>` cannot be shared between threads safely
+    //~| NOTE if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead
+
+    require_sync::<std::cell::Cell<bool>>();
+    //~^ ERROR `Cell<bool>` cannot be shared between threads safely
+    //~| NOTE `Cell<bool>` cannot be shared between threads safely
+    //~| NOTE if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicBool` instead
+}
diff --git a/tests/ui/sync/suggest-cell.stderr b/tests/ui/sync/suggest-cell.stderr
new file mode 100644
index 00000000000..c232c1ccd53
--- /dev/null
+++ b/tests/ui/sync/suggest-cell.stderr
@@ -0,0 +1,59 @@
+error[E0277]: `Cell<()>` cannot be shared between threads safely
+  --> $DIR/suggest-cell.rs:12:20
+   |
+LL |     require_sync::<std::cell::Cell<()>>();
+   |                    ^^^^^^^^^^^^^^^^^^^ `Cell<()>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `Cell<()>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock`
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-cell.rs:1:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error[E0277]: `Cell<u8>` cannot be shared between threads safely
+  --> $DIR/suggest-cell.rs:17:20
+   |
+LL |     require_sync::<std::cell::Cell<u8>>();
+   |                    ^^^^^^^^^^^^^^^^^^^ `Cell<u8>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `Cell<u8>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU8` instead
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-cell.rs:1:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error[E0277]: `Cell<i32>` cannot be shared between threads safely
+  --> $DIR/suggest-cell.rs:22:20
+   |
+LL |     require_sync::<std::cell::Cell<i32>>();
+   |                    ^^^^^^^^^^^^^^^^^^^^ `Cell<i32>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `Cell<i32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-cell.rs:1:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error[E0277]: `Cell<bool>` cannot be shared between threads safely
+  --> $DIR/suggest-cell.rs:27:20
+   |
+LL |     require_sync::<std::cell::Cell<bool>>();
+   |                    ^^^^^^^^^^^^^^^^^^^^^ `Cell<bool>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `Cell<bool>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicBool` instead
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-cell.rs:1:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/sync/suggest-once-cell.rs b/tests/ui/sync/suggest-once-cell.rs
new file mode 100644
index 00000000000..82fca45b1a4
--- /dev/null
+++ b/tests/ui/sync/suggest-once-cell.rs
@@ -0,0 +1,12 @@
+#![feature(once_cell)]
+
+fn require_sync<T: Sync>() {}
+//~^ NOTE required by this bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+
+fn main() {
+    require_sync::<std::cell::OnceCell<()>>();
+    //~^ ERROR `OnceCell<()>` cannot be shared between threads safely
+    //~| NOTE `OnceCell<()>` cannot be shared between threads safely
+    //~| NOTE use `std::sync::OnceLock` instead
+}
diff --git a/tests/ui/sync/suggest-once-cell.stderr b/tests/ui/sync/suggest-once-cell.stderr
new file mode 100644
index 00000000000..fadf05374d8
--- /dev/null
+++ b/tests/ui/sync/suggest-once-cell.stderr
@@ -0,0 +1,17 @@
+error[E0277]: `OnceCell<()>` cannot be shared between threads safely
+  --> $DIR/suggest-once-cell.rs:8:20
+   |
+LL |     require_sync::<std::cell::OnceCell<()>>();
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^ `OnceCell<()>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `OnceCell<()>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::OnceLock` instead
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-once-cell.rs:3:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/sync/suggest-ref-cell.rs b/tests/ui/sync/suggest-ref-cell.rs
new file mode 100644
index 00000000000..6b972ae0962
--- /dev/null
+++ b/tests/ui/sync/suggest-ref-cell.rs
@@ -0,0 +1,12 @@
+#![feature(once_cell)]
+
+fn require_sync<T: Sync>() {}
+//~^ NOTE required by this bound in `require_sync`
+//~| NOTE required by a bound in `require_sync`
+
+fn main() {
+    require_sync::<std::cell::RefCell<()>>();
+    //~^ ERROR `RefCell<()>` cannot be shared between threads safely
+    //~| NOTE `RefCell<()>` cannot be shared between threads safely
+    //~| NOTE use `std::sync::RwLock` instead
+}
diff --git a/tests/ui/sync/suggest-ref-cell.stderr b/tests/ui/sync/suggest-ref-cell.stderr
new file mode 100644
index 00000000000..9e8b8fcb42e
--- /dev/null
+++ b/tests/ui/sync/suggest-ref-cell.stderr
@@ -0,0 +1,17 @@
+error[E0277]: `RefCell<()>` cannot be shared between threads safely
+  --> $DIR/suggest-ref-cell.rs:8:20
+   |
+LL |     require_sync::<std::cell::RefCell<()>>();
+   |                    ^^^^^^^^^^^^^^^^^^^^^^ `RefCell<()>` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `RefCell<()>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
+note: required by a bound in `require_sync`
+  --> $DIR/suggest-ref-cell.rs:3:20
+   |
+LL | fn require_sync<T: Sync>() {}
+   |                    ^^^^ required by this bound in `require_sync`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/thir-print/thir-flat.rs b/tests/ui/thir-print/thir-flat.rs
new file mode 100644
index 00000000000..8fa95ce62b5
--- /dev/null
+++ b/tests/ui/thir-print/thir-flat.rs
@@ -0,0 +1,4 @@
+// compile-flags: -Z unpretty=thir-flat
+// check-pass
+
+pub fn main() {}
diff --git a/tests/ui/thir-tree.stdout b/tests/ui/thir-print/thir-flat.stdout
index 4b6915f7715..c399fa66b6a 100644
--- a/tests/ui/thir-tree.stdout
+++ b/tests/ui/thir-print/thir-flat.stdout
@@ -1,4 +1,4 @@
-DefId(0:3 ~ thir_tree[8f1d]::main):
+DefId(0:3 ~ thir_flat[45a6]::main):
 Thir {
     arms: [],
     blocks: [
@@ -6,7 +6,7 @@ Thir {
             targeted_by_break: false,
             region_scope: Node(1),
             opt_destruction_scope: None,
-            span: $DIR/thir-tree.rs:4:15: 4:17 (#0),
+            span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
             stmts: [],
             expr: None,
             safety_mode: Safe,
@@ -18,7 +18,7 @@ Thir {
             temp_lifetime: Some(
                 Node(2),
             ),
-            span: $DIR/thir-tree.rs:4:15: 4:17 (#0),
+            span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
             kind: Block {
                 block: b0,
             },
@@ -28,11 +28,11 @@ Thir {
             temp_lifetime: Some(
                 Node(2),
             ),
-            span: $DIR/thir-tree.rs:4:15: 4:17 (#0),
+            span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
             kind: Scope {
                 region_scope: Node(2),
                 lint_level: Explicit(
-                    HirId(DefId(0:3 ~ thir_tree[8f1d]::main).2),
+                    HirId(DefId(0:3 ~ thir_flat[45a6]::main).2),
                 ),
                 value: e0,
             },
@@ -42,7 +42,7 @@ Thir {
             temp_lifetime: Some(
                 Node(2),
             ),
-            span: $DIR/thir-tree.rs:4:15: 4:17 (#0),
+            span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
             kind: Scope {
                 region_scope: Destruction(2),
                 lint_level: Inherited,
diff --git a/tests/ui/thir-print/thir-tree-match.rs b/tests/ui/thir-print/thir-tree-match.rs
new file mode 100644
index 00000000000..a5511ec9543
--- /dev/null
+++ b/tests/ui/thir-print/thir-tree-match.rs
@@ -0,0 +1,23 @@
+// check-pass
+// compile-flags: -Zunpretty=thir-tree
+
+enum Bar {
+    First,
+    Second,
+    Third,
+}
+
+enum Foo {
+    FooOne(Bar),
+    FooTwo,
+}
+
+fn has_match(foo: Foo) -> bool {
+    match foo {
+        Foo::FooOne(Bar::First) => true,
+        Foo::FooOne(_) => false,
+        Foo::FooTwo => true,
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/thir-print/thir-tree-match.stdout b/tests/ui/thir-print/thir-tree-match.stdout
new file mode 100644
index 00000000000..d6174ec262a
--- /dev/null
+++ b/tests/ui/thir-print/thir-tree-match.stdout
@@ -0,0 +1,342 @@
+DefId(0:16 ~ thir_tree_match[3c9a]::has_match):
+params: [
+    Param {
+        ty: Foo
+        ty_span: Some($DIR/thir-tree-match.rs:15:19: 15:22 (#0))
+        self_kind: None
+        hir_id: Some(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).1))
+        param: Some( 
+            Pat: {
+                ty: Foo
+                span: $DIR/thir-tree-match.rs:15:14: 15:17 (#0)
+                kind: PatKind {
+                    Binding {
+                        mutability: Not
+                        name: "foo"
+                        mode: ByValue
+                        var: LocalVarId(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).2))
+                        ty: Foo
+                        is_primary: true
+                        subpattern: None
+                    }
+                }
+            }
+        )
+    }
+]
+body:
+    Expr {
+        ty: bool
+        temp_lifetime: Some(Node(26))
+        span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
+        kind: 
+            Scope {
+                region_scope: Destruction(26)
+                lint_level: Inherited
+                value:
+                    Expr {
+                        ty: bool
+                        temp_lifetime: Some(Node(26))
+                        span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
+                        kind: 
+                            Scope {
+                                region_scope: Node(26)
+                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).26))
+                                value:
+                                    Expr {
+                                        ty: bool
+                                        temp_lifetime: Some(Node(26))
+                                        span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
+                                        kind: 
+                                            Block {
+                                                targeted_by_break: false
+                                                opt_destruction_scope: None
+                                                span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
+                                                region_scope: Node(25)
+                                                safety_mode: Safe
+                                                stmts: []
+                                                expr:
+                                                    Expr {
+                                                        ty: bool
+                                                        temp_lifetime: Some(Node(26))
+                                                        span: $DIR/thir-tree-match.rs:16:5: 20:6 (#0)
+                                                        kind: 
+                                                            Scope {
+                                                                region_scope: Node(3)
+                                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).3))
+                                                                value:
+                                                                    Expr {
+                                                                        ty: bool
+                                                                        temp_lifetime: Some(Node(26))
+                                                                        span: $DIR/thir-tree-match.rs:16:5: 20:6 (#0)
+                                                                        kind: 
+                                                                            Match {
+                                                                                scrutinee:
+                                                                                    Expr {
+                                                                                        ty: Foo
+                                                                                        temp_lifetime: Some(Node(26))
+                                                                                        span: $DIR/thir-tree-match.rs:16:11: 16:14 (#0)
+                                                                                        kind: 
+                                                                                            Scope {
+                                                                                                region_scope: Node(4)
+                                                                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).4))
+                                                                                                value:
+                                                                                                    Expr {
+                                                                                                        ty: Foo
+                                                                                                        temp_lifetime: Some(Node(26))
+                                                                                                        span: $DIR/thir-tree-match.rs:16:11: 16:14 (#0)
+                                                                                                        kind: 
+                                                                                                            VarRef {
+                                                                                                                id: LocalVarId(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).2))
+                                                                                                            }
+                                                                                                    }
+                                                                                            }
+                                                                                    }
+                                                                                arms: [
+                                                                                    Arm {
+                                                                                        pattern: 
+                                                                                            Pat: {
+                                                                                                ty: Foo
+                                                                                                span: $DIR/thir-tree-match.rs:17:9: 17:32 (#0)
+                                                                                                kind: PatKind {
+                                                                                                    Variant {
+                                                                                                        adt_def: 
+                                                                                                            AdtDef {
+                                                                                                                did: DefId(0:10 ~ thir_tree_match[3c9a]::Foo)
+                                                                                                                variants: [VariantDef { def_id: DefId(0:11 ~ thir_tree_match[3c9a]::Foo::FooOne), ctor: Some((Fn, DefId(0:12 ~ thir_tree_match[3c9a]::Foo::FooOne::{constructor#0}))), name: "FooOne", discr: Relative(0), fields: [FieldDef { did: DefId(0:13 ~ thir_tree_match[3c9a]::Foo::FooOne::0), name: "0", vis: Restricted(DefId(0:0 ~ thir_tree_match[3c9a])) }], flags: NO_VARIANT_FLAGS }, VariantDef { def_id: DefId(0:14 ~ thir_tree_match[3c9a]::Foo::FooTwo), ctor: Some((Const, DefId(0:15 ~ thir_tree_match[3c9a]::Foo::FooTwo::{constructor#0}))), name: "FooTwo", discr: Relative(1), fields: [], flags: NO_VARIANT_FLAGS }]
+                                                                                                                flags: IS_ENUM
+                                                                                                                repr: ReprOptions { int: None, align: None, pack: None, flags: (empty), field_shuffle_seed: 11573694388057581 }
+                                                                                                        substs: []
+                                                                                                        variant_index: 0
+                                                                                                        subpatterns: [
+                                                                                                            Pat: {
+                                                                                                                ty: Bar
+                                                                                                                span: $DIR/thir-tree-match.rs:17:21: 17:31 (#0)
+                                                                                                                kind: PatKind {
+                                                                                                                    Variant {
+                                                                                                                        adt_def: 
+                                                                                                                            AdtDef {
+                                                                                                                                did: DefId(0:3 ~ thir_tree_match[3c9a]::Bar)
+                                                                                                                                variants: [VariantDef { def_id: DefId(0:4 ~ thir_tree_match[3c9a]::Bar::First), ctor: Some((Const, DefId(0:5 ~ thir_tree_match[3c9a]::Bar::First::{constructor#0}))), name: "First", discr: Relative(0), fields: [], flags: NO_VARIANT_FLAGS }, VariantDef { def_id: DefId(0:6 ~ thir_tree_match[3c9a]::Bar::Second), ctor: Some((Const, DefId(0:7 ~ thir_tree_match[3c9a]::Bar::Second::{constructor#0}))), name: "Second", discr: Relative(1), fields: [], flags: NO_VARIANT_FLAGS }, VariantDef { def_id: DefId(0:8 ~ thir_tree_match[3c9a]::Bar::Third), ctor: Some((Const, DefId(0:9 ~ thir_tree_match[3c9a]::Bar::Third::{constructor#0}))), name: "Third", discr: Relative(2), fields: [], flags: NO_VARIANT_FLAGS }]
+                                                                                                                                flags: IS_ENUM
+                                                                                                                                repr: ReprOptions { int: None, align: None, pack: None, flags: (empty), field_shuffle_seed: 3125160937860410723 }
+                                                                                                                        substs: []
+                                                                                                                        variant_index: 0
+                                                                                                                        subpatterns: []
+                                                                                                                    }
+                                                                                                                }
+                                                                                                            }
+                                                                                                        ]
+                                                                                                    }
+                                                                                                }
+                                                                                            }
+                                                                                        guard: None
+                                                                                        body: 
+                                                                                            Expr {
+                                                                                                ty: bool
+                                                                                                temp_lifetime: Some(Node(13))
+                                                                                                span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
+                                                                                                kind: 
+                                                                                                    Scope {
+                                                                                                        region_scope: Destruction(13)
+                                                                                                        lint_level: Inherited
+                                                                                                        value:
+                                                                                                            Expr {
+                                                                                                                ty: bool
+                                                                                                                temp_lifetime: Some(Node(13))
+                                                                                                                span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
+                                                                                                                kind: 
+                                                                                                                    Scope {
+                                                                                                                        region_scope: Node(13)
+                                                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).13))
+                                                                                                                        value:
+                                                                                                                            Expr {
+                                                                                                                                ty: bool
+                                                                                                                                temp_lifetime: Some(Node(13))
+                                                                                                                                span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
+                                                                                                                                kind: 
+                                                                                                                                    Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0) }, neg: false)
+
+                                                                                                                            }
+                                                                                                                    }
+                                                                                                            }
+                                                                                                    }
+                                                                                            }
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).12))
+                                                                                        scope: Node(12)
+                                                                                        span: $DIR/thir-tree-match.rs:17:9: 17:40 (#0)
+                                                                                    }
+                                                                                    Arm {
+                                                                                        pattern: 
+                                                                                            Pat: {
+                                                                                                ty: Foo
+                                                                                                span: $DIR/thir-tree-match.rs:18:9: 18:23 (#0)
+                                                                                                kind: PatKind {
+                                                                                                    Variant {
+                                                                                                        adt_def: 
+                                                                                                            AdtDef {
+                                                                                                                did: DefId(0:10 ~ thir_tree_match[3c9a]::Foo)
+                                                                                                                variants: [VariantDef { def_id: DefId(0:11 ~ thir_tree_match[3c9a]::Foo::FooOne), ctor: Some((Fn, DefId(0:12 ~ thir_tree_match[3c9a]::Foo::FooOne::{constructor#0}))), name: "FooOne", discr: Relative(0), fields: [FieldDef { did: DefId(0:13 ~ thir_tree_match[3c9a]::Foo::FooOne::0), name: "0", vis: Restricted(DefId(0:0 ~ thir_tree_match[3c9a])) }], flags: NO_VARIANT_FLAGS }, VariantDef { def_id: DefId(0:14 ~ thir_tree_match[3c9a]::Foo::FooTwo), ctor: Some((Const, DefId(0:15 ~ thir_tree_match[3c9a]::Foo::FooTwo::{constructor#0}))), name: "FooTwo", discr: Relative(1), fields: [], flags: NO_VARIANT_FLAGS }]
+                                                                                                                flags: IS_ENUM
+                                                                                                                repr: ReprOptions { int: None, align: None, pack: None, flags: (empty), field_shuffle_seed: 11573694388057581 }
+                                                                                                        substs: []
+                                                                                                        variant_index: 0
+                                                                                                        subpatterns: [
+                                                                                                            Pat: {
+                                                                                                                ty: Bar
+                                                                                                                span: $DIR/thir-tree-match.rs:18:21: 18:22 (#0)
+                                                                                                                kind: PatKind {
+                                                                                                                    Wild
+                                                                                                                }
+                                                                                                            }
+                                                                                                        ]
+                                                                                                    }
+                                                                                                }
+                                                                                            }
+                                                                                        guard: None
+                                                                                        body: 
+                                                                                            Expr {
+                                                                                                ty: bool
+                                                                                                temp_lifetime: Some(Node(19))
+                                                                                                span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
+                                                                                                kind: 
+                                                                                                    Scope {
+                                                                                                        region_scope: Destruction(19)
+                                                                                                        lint_level: Inherited
+                                                                                                        value:
+                                                                                                            Expr {
+                                                                                                                ty: bool
+                                                                                                                temp_lifetime: Some(Node(19))
+                                                                                                                span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
+                                                                                                                kind: 
+                                                                                                                    Scope {
+                                                                                                                        region_scope: Node(19)
+                                                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).19))
+                                                                                                                        value:
+                                                                                                                            Expr {
+                                                                                                                                ty: bool
+                                                                                                                                temp_lifetime: Some(Node(19))
+                                                                                                                                span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
+                                                                                                                                kind: 
+                                                                                                                                    Literal( lit: Spanned { node: Bool(false), span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0) }, neg: false)
+
+                                                                                                                            }
+                                                                                                                    }
+                                                                                                            }
+                                                                                                    }
+                                                                                            }
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).18))
+                                                                                        scope: Node(18)
+                                                                                        span: $DIR/thir-tree-match.rs:18:9: 18:32 (#0)
+                                                                                    }
+                                                                                    Arm {
+                                                                                        pattern: 
+                                                                                            Pat: {
+                                                                                                ty: Foo
+                                                                                                span: $DIR/thir-tree-match.rs:19:9: 19:20 (#0)
+                                                                                                kind: PatKind {
+                                                                                                    Variant {
+                                                                                                        adt_def: 
+                                                                                                            AdtDef {
+                                                                                                                did: DefId(0:10 ~ thir_tree_match[3c9a]::Foo)
+                                                                                                                variants: [VariantDef { def_id: DefId(0:11 ~ thir_tree_match[3c9a]::Foo::FooOne), ctor: Some((Fn, DefId(0:12 ~ thir_tree_match[3c9a]::Foo::FooOne::{constructor#0}))), name: "FooOne", discr: Relative(0), fields: [FieldDef { did: DefId(0:13 ~ thir_tree_match[3c9a]::Foo::FooOne::0), name: "0", vis: Restricted(DefId(0:0 ~ thir_tree_match[3c9a])) }], flags: NO_VARIANT_FLAGS }, VariantDef { def_id: DefId(0:14 ~ thir_tree_match[3c9a]::Foo::FooTwo), ctor: Some((Const, DefId(0:15 ~ thir_tree_match[3c9a]::Foo::FooTwo::{constructor#0}))), name: "FooTwo", discr: Relative(1), fields: [], flags: NO_VARIANT_FLAGS }]
+                                                                                                                flags: IS_ENUM
+                                                                                                                repr: ReprOptions { int: None, align: None, pack: None, flags: (empty), field_shuffle_seed: 11573694388057581 }
+                                                                                                        substs: []
+                                                                                                        variant_index: 1
+                                                                                                        subpatterns: []
+                                                                                                    }
+                                                                                                }
+                                                                                            }
+                                                                                        guard: None
+                                                                                        body: 
+                                                                                            Expr {
+                                                                                                ty: bool
+                                                                                                temp_lifetime: Some(Node(24))
+                                                                                                span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
+                                                                                                kind: 
+                                                                                                    Scope {
+                                                                                                        region_scope: Destruction(24)
+                                                                                                        lint_level: Inherited
+                                                                                                        value:
+                                                                                                            Expr {
+                                                                                                                ty: bool
+                                                                                                                temp_lifetime: Some(Node(24))
+                                                                                                                span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
+                                                                                                                kind: 
+                                                                                                                    Scope {
+                                                                                                                        region_scope: Node(24)
+                                                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).24))
+                                                                                                                        value:
+                                                                                                                            Expr {
+                                                                                                                                ty: bool
+                                                                                                                                temp_lifetime: Some(Node(24))
+                                                                                                                                span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
+                                                                                                                                kind: 
+                                                                                                                                    Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0) }, neg: false)
+
+                                                                                                                            }
+                                                                                                                    }
+                                                                                                            }
+                                                                                                    }
+                                                                                            }
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[3c9a]::has_match).23))
+                                                                                        scope: Node(23)
+                                                                                        span: $DIR/thir-tree-match.rs:19:9: 19:28 (#0)
+                                                                                    }
+                                                                                ]
+                                                                            }
+                                                                    }
+                                                            }
+                                                    }
+                                            }
+                                    }
+                            }
+                    }
+            }
+    }
+
+
+DefId(0:17 ~ thir_tree_match[3c9a]::main):
+params: [
+]
+body:
+    Expr {
+        ty: ()
+        temp_lifetime: Some(Node(2))
+        span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
+        kind: 
+            Scope {
+                region_scope: Destruction(2)
+                lint_level: Inherited
+                value:
+                    Expr {
+                        ty: ()
+                        temp_lifetime: Some(Node(2))
+                        span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
+                        kind: 
+                            Scope {
+                                region_scope: Node(2)
+                                lint_level: Explicit(HirId(DefId(0:17 ~ thir_tree_match[3c9a]::main).2))
+                                value:
+                                    Expr {
+                                        ty: ()
+                                        temp_lifetime: Some(Node(2))
+                                        span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
+                                        kind: 
+                                            Block {
+                                                targeted_by_break: false
+                                                opt_destruction_scope: None
+                                                span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
+                                                region_scope: Node(1)
+                                                safety_mode: Safe
+                                                stmts: []
+                                                expr: []
+                                            }
+                                    }
+                            }
+                    }
+            }
+    }
+
+
diff --git a/tests/ui/thir-tree.rs b/tests/ui/thir-print/thir-tree.rs
index 32df7905adb..32df7905adb 100644
--- a/tests/ui/thir-tree.rs
+++ b/tests/ui/thir-print/thir-tree.rs
diff --git a/tests/ui/thir-print/thir-tree.stdout b/tests/ui/thir-print/thir-tree.stdout
new file mode 100644
index 00000000000..0a35d9fb78c
--- /dev/null
+++ b/tests/ui/thir-print/thir-tree.stdout
@@ -0,0 +1,43 @@
+DefId(0:3 ~ thir_tree[8f1d]::main):
+params: [
+]
+body:
+    Expr {
+        ty: ()
+        temp_lifetime: Some(Node(2))
+        span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
+        kind: 
+            Scope {
+                region_scope: Destruction(2)
+                lint_level: Inherited
+                value:
+                    Expr {
+                        ty: ()
+                        temp_lifetime: Some(Node(2))
+                        span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
+                        kind: 
+                            Scope {
+                                region_scope: Node(2)
+                                lint_level: Explicit(HirId(DefId(0:3 ~ thir_tree[8f1d]::main).2))
+                                value:
+                                    Expr {
+                                        ty: ()
+                                        temp_lifetime: Some(Node(2))
+                                        span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
+                                        kind: 
+                                            Block {
+                                                targeted_by_break: false
+                                                opt_destruction_scope: None
+                                                span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
+                                                region_scope: Node(1)
+                                                safety_mode: Safe
+                                                stmts: []
+                                                expr: []
+                                            }
+                                    }
+                            }
+                    }
+            }
+    }
+
+
diff --git a/tests/ui/traits/alias/issue-60755.rs b/tests/ui/traits/alias/issue-60755.rs
new file mode 100644
index 00000000000..6b955a75247
--- /dev/null
+++ b/tests/ui/traits/alias/issue-60755.rs
@@ -0,0 +1,12 @@
+// check-pass
+
+#![feature(trait_alias)]
+
+struct MyStruct {}
+trait MyFn = Fn(&MyStruct);
+
+fn foo(_: impl MyFn) {}
+
+fn main() {
+    foo(|_| {});
+}
diff --git a/tests/ui/traits/associated_type_bound/check-trait-object-bounds-3.stderr b/tests/ui/traits/associated_type_bound/check-trait-object-bounds-3.stderr
index ade552c4bab..c7af71a4214 100644
--- a/tests/ui/traits/associated_type_bound/check-trait-object-bounds-3.stderr
+++ b/tests/ui/traits/associated_type_bound/check-trait-object-bounds-3.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `s` does not live long enough
   --> $DIR/check-trait-object-bounds-3.rs:15:34
    |
+LL |         let s = String::from("abcdef");
+   |             - binding `s` declared here
 LL |         z = f::<dyn X<Y = &str>>(&s);
    |             ---------------------^^-
    |             |                    |
diff --git a/tests/ui/traits/coercion-generic-regions.stderr b/tests/ui/traits/coercion-generic-regions.stderr
index 5cfb6490123..ae70202ab7c 100644
--- a/tests/ui/traits/coercion-generic-regions.stderr
+++ b/tests/ui/traits/coercion-generic-regions.stderr
@@ -1,6 +1,8 @@
 error[E0597]: `person` does not live long enough
   --> $DIR/coercion-generic-regions.rs:17:24
    |
+LL |     let person = "Fred".to_string();
+   |         ------ binding `person` declared here
 LL |     let person: &str = &person;
    |                        ^^^^^^^
    |                        |
diff --git a/tests/ui/traits/new-solver/async.fail.stderr b/tests/ui/traits/new-solver/async.fail.stderr
new file mode 100644
index 00000000000..b395c23ae00
--- /dev/null
+++ b/tests/ui/traits/new-solver/async.fail.stderr
@@ -0,0 +1,17 @@
+error[E0271]: expected `[async block@$DIR/async.rs:12:17: 12:25]` to be a future that resolves to `i32`, but it resolves to `()`
+  --> $DIR/async.rs:12:17
+   |
+LL |     needs_async(async {});
+   |     ----------- ^^^^^^^^ expected `i32`, found `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `needs_async`
+  --> $DIR/async.rs:8:31
+   |
+LL | fn needs_async(_: impl Future<Output = i32>) {}
+   |                               ^^^^^^^^^^^^ required by this bound in `needs_async`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0271`.
diff --git a/tests/ui/traits/new-solver/async.rs b/tests/ui/traits/new-solver/async.rs
new file mode 100644
index 00000000000..195cc35cad2
--- /dev/null
+++ b/tests/ui/traits/new-solver/async.rs
@@ -0,0 +1,19 @@
+// compile-flags: -Ztrait-solver=next
+// edition: 2021
+// revisions: pass fail
+//[pass] check-pass
+
+use std::future::Future;
+
+fn needs_async(_: impl Future<Output = i32>) {}
+
+#[cfg(fail)]
+fn main() {
+    needs_async(async {});
+    //[fail]~^ ERROR to be a future that resolves to `i32`, but it resolves to `()`
+}
+
+#[cfg(pass)]
+fn main() {
+    needs_async(async { 1i32 });
+}
diff --git a/tests/ui/traits/new-solver/generator.fail.stderr b/tests/ui/traits/new-solver/generator.fail.stderr
new file mode 100644
index 00000000000..d94d41e3587
--- /dev/null
+++ b/tests/ui/traits/new-solver/generator.fail.stderr
@@ -0,0 +1,64 @@
+error[E0277]: the trait bound `[generator@$DIR/generator.rs:18:21: 18:23]: Generator<A>` is not satisfied
+  --> $DIR/generator.rs:18:21
+   |
+LL |       needs_generator(|| {
+   |  _____---------------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |
+LL | |
+LL | |         yield ();
+LL | |     });
+   | |_____^ the trait `Generator<A>` is not implemented for `[generator@$DIR/generator.rs:18:21: 18:23]`
+   |
+note: required by a bound in `needs_generator`
+  --> $DIR/generator.rs:14:28
+   |
+LL | fn needs_generator(_: impl Generator<A, Yield = B, Return = C>) {}
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `needs_generator`
+
+error[E0271]: type mismatch resolving `<[generator@$DIR/generator.rs:18:21: 18:23] as Generator<A>>::Yield == B`
+  --> $DIR/generator.rs:18:21
+   |
+LL |       needs_generator(|| {
+   |  _____---------------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |
+LL | |
+LL | |         yield ();
+LL | |     });
+   | |_____^ types differ
+   |
+note: required by a bound in `needs_generator`
+  --> $DIR/generator.rs:14:41
+   |
+LL | fn needs_generator(_: impl Generator<A, Yield = B, Return = C>) {}
+   |                                         ^^^^^^^^^ required by this bound in `needs_generator`
+
+error[E0271]: type mismatch resolving `<[generator@$DIR/generator.rs:18:21: 18:23] as Generator<A>>::Return == C`
+  --> $DIR/generator.rs:18:21
+   |
+LL |       needs_generator(|| {
+   |  _____---------------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |
+LL | |
+LL | |         yield ();
+LL | |     });
+   | |_____^ types differ
+   |
+note: required by a bound in `needs_generator`
+  --> $DIR/generator.rs:14:52
+   |
+LL | fn needs_generator(_: impl Generator<A, Yield = B, Return = C>) {}
+   |                                                    ^^^^^^^^^^ required by this bound in `needs_generator`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0271, E0277.
+For more information about an error, try `rustc --explain E0271`.
diff --git a/tests/ui/traits/new-solver/generator.rs b/tests/ui/traits/new-solver/generator.rs
new file mode 100644
index 00000000000..364373ca8be
--- /dev/null
+++ b/tests/ui/traits/new-solver/generator.rs
@@ -0,0 +1,32 @@
+// compile-flags: -Ztrait-solver=next
+// edition: 2021
+// revisions: pass fail
+//[pass] check-pass
+
+#![feature(generator_trait, generators)]
+
+use std::ops::Generator;
+
+struct A;
+struct B;
+struct C;
+
+fn needs_generator(_: impl Generator<A, Yield = B, Return = C>) {}
+
+#[cfg(fail)]
+fn main() {
+    needs_generator(|| {
+        //[fail]~^ ERROR Generator<A>` is not satisfied
+        //[fail]~| ERROR as Generator<A>>::Yield == B`
+        //[fail]~| ERROR as Generator<A>>::Return == C`
+        yield ();
+    });
+}
+
+#[cfg(pass)]
+fn main() {
+    needs_generator(|_: A| {
+        let _: A = yield B;
+        C
+    })
+}
diff --git a/tests/ui/traits/new-solver/pointee.rs b/tests/ui/traits/new-solver/pointee.rs
new file mode 100644
index 00000000000..fa6ee2e2daf
--- /dev/null
+++ b/tests/ui/traits/new-solver/pointee.rs
@@ -0,0 +1,23 @@
+// compile-flags: -Ztrait-solver=next
+// check-pass
+#![feature(ptr_metadata)]
+
+use std::ptr::{DynMetadata, Pointee};
+
+trait Trait<U> {}
+struct MyDst<T: ?Sized>(T);
+
+fn works<T>() {
+    let _: <T as Pointee>::Metadata = ();
+    let _: <[T] as Pointee>::Metadata = 1_usize;
+    let _: <str as Pointee>::Metadata = 1_usize;
+    let _: <dyn Trait<T> as Pointee>::Metadata = give::<DynMetadata<dyn Trait<T>>>();
+    let _: <MyDst<T> as Pointee>::Metadata = ();
+    let _: <((((([u8],),),),),) as Pointee>::Metadata = 1_usize;
+}
+
+fn give<U>() -> U {
+    loop {}
+}
+
+fn main() {}
diff --git a/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.rs b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.rs
new file mode 100644
index 00000000000..3c6ab86e4c6
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.rs
@@ -0,0 +1,10 @@
+#![feature(multiple_supertrait_upcastable)]
+#![deny(multiple_supertrait_upcastable)]
+
+trait A {}
+trait B {}
+
+trait C: A + B {}
+//~^ ERROR `C` is object-safe and has multiple supertraits
+
+fn main() {}
diff --git a/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr
new file mode 100644
index 00000000000..ad80a009ece
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr
@@ -0,0 +1,14 @@
+error: `C` is object-safe and has multiple supertraits
+  --> $DIR/multiple_supertrait_upcastable.rs:7:1
+   |
+LL | trait C: A + B {}
+   | ^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/multiple_supertrait_upcastable.rs:2:9
+   |
+LL | #![deny(multiple_supertrait_upcastable)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/traits/vtable/issue-97381.stderr b/tests/ui/traits/vtable/issue-97381.stderr
index c4f8294e263..89360c44e78 100644
--- a/tests/ui/traits/vtable/issue-97381.stderr
+++ b/tests/ui/traits/vtable/issue-97381.stderr
@@ -1,6 +1,9 @@
 error[E0505]: cannot move out of `v` because it is borrowed
   --> $DIR/issue-97381.rs:26:14
    |
+LL |     let v = [1, 2, 3]
+   |         - binding `v` declared here
+...
 LL |     let el = &v[0];
    |               - borrow of `v` occurs here
 LL |
diff --git a/tests/ui/try-block/try-block-bad-lifetime.stderr b/tests/ui/try-block/try-block-bad-lifetime.stderr
index ea079e30d9c..28941cb0a9e 100644
--- a/tests/ui/try-block/try-block-bad-lifetime.stderr
+++ b/tests/ui/try-block/try-block-bad-lifetime.stderr
@@ -4,6 +4,7 @@ error[E0597]: `my_string` does not live long enough
 LL |         let result: Result<(), &str> = try {
    |             ------ borrow later stored here
 LL |             let my_string = String::from("");
+   |                 --------- binding `my_string` declared here
 LL |             let my_str: & str = & my_string;
    |                                 ^^^^^^^^^^^ borrowed value does not live long enough
 ...
@@ -14,10 +15,10 @@ error[E0506]: cannot assign to `i` because it is borrowed
   --> $DIR/try-block-bad-lifetime.rs:29:13
    |
 LL |         let k = &mut i;
-   |                 ------ borrow of `i` occurs here
+   |                 ------ `i` is borrowed here
 ...
 LL |             i = 10;
-   |             ^^^^^^ assignment to borrowed `i` occurs here
+   |             ^^^^^^ `i` is assigned to here but it was already borrowed
 LL |         };
 LL |         ::std::mem::drop(k);
    |                          - borrow later used here
@@ -38,10 +39,10 @@ error[E0506]: cannot assign to `i` because it is borrowed
   --> $DIR/try-block-bad-lifetime.rs:32:9
    |
 LL |         let k = &mut i;
-   |                 ------ borrow of `i` occurs here
+   |                 ------ `i` is borrowed here
 ...
 LL |         i = 40;
-   |         ^^^^^^ assignment to borrowed `i` occurs here
+   |         ^^^^^^ `i` is assigned to here but it was already borrowed
 LL |
 LL |         let i_ptr = if let Err(i_ptr) = j { i_ptr } else { panic ! ("") };
    |                                         - borrow later used here
diff --git a/tests/ui/try-block/try-block-maybe-bad-lifetime.stderr b/tests/ui/try-block/try-block-maybe-bad-lifetime.stderr
index f738b03eed6..71c7e460c39 100644
--- a/tests/ui/try-block/try-block-maybe-bad-lifetime.stderr
+++ b/tests/ui/try-block/try-block-maybe-bad-lifetime.stderr
@@ -2,10 +2,10 @@ error[E0506]: cannot assign to `i` because it is borrowed
   --> $DIR/try-block-maybe-bad-lifetime.rs:17:9
    |
 LL |             &i
-   |             -- borrow of `i` occurs here
+   |             -- `i` is borrowed here
 LL |         };
 LL |         i = 0;
-   |         ^^^^^ assignment to borrowed `i` occurs here
+   |         ^^^^^ `i` is assigned to here but it was already borrowed
 LL |         let _ = i;
 LL |         do_something_with(x);
    |                           - borrow later used here
@@ -32,10 +32,10 @@ error[E0506]: cannot assign to `i` because it is borrowed
   --> $DIR/try-block-maybe-bad-lifetime.rs:40:9
    |
 LL |             j = &i;
-   |                 -- borrow of `i` occurs here
+   |                 -- `i` is borrowed here
 LL |         };
 LL |         i = 0;
-   |         ^^^^^ assignment to borrowed `i` occurs here
+   |         ^^^^^ `i` is assigned to here but it was already borrowed
 LL |         let _ = i;
 LL |         do_something_with(j);
    |                           - borrow later used here
diff --git a/tests/ui/type-alias-impl-trait/bounds-are-checked.rs b/tests/ui/type-alias-impl-trait/bounds-are-checked.rs
index 83d22161e4e..eeb5dca07f0 100644
--- a/tests/ui/type-alias-impl-trait/bounds-are-checked.rs
+++ b/tests/ui/type-alias-impl-trait/bounds-are-checked.rs
@@ -8,7 +8,7 @@ type X<'a> = impl Into<&'static str> + From<&'a str>;
 fn f<'a: 'static>(t: &'a str) -> X<'a> {
     //~^ WARNING unnecessary lifetime parameter
     t
-    //~^ ERROR non-defining opaque type use
+    //~^ ERROR expected generic lifetime parameter, found `'static`
 }
 
 fn extend_lt<'a>(o: &'a str) -> &'static str {
diff --git a/tests/ui/type-alias-impl-trait/bounds-are-checked.stderr b/tests/ui/type-alias-impl-trait/bounds-are-checked.stderr
index 920eef11da4..94882597a62 100644
--- a/tests/ui/type-alias-impl-trait/bounds-are-checked.stderr
+++ b/tests/ui/type-alias-impl-trait/bounds-are-checked.stderr
@@ -6,7 +6,7 @@ LL | fn f<'a: 'static>(t: &'a str) -> X<'a> {
    |
    = help: you can use the `'static` lifetime directly, in place of `'a`
 
-error: non-defining opaque type use in defining scope
+error[E0792]: expected generic lifetime parameter, found `'static`
   --> $DIR/bounds-are-checked.rs:10:5
    |
 LL | type X<'a> = impl Into<&'static str> + From<&'a str>;
@@ -17,3 +17,4 @@ LL |     t
 
 error: aborting due to previous error; 1 warning emitted
 
+For more information about this error, try `rustc --explain E0792`.
diff --git a/tests/ui/type-alias-impl-trait/generic_nondefining_use.rs b/tests/ui/type-alias-impl-trait/generic_nondefining_use.rs
index f5045d382aa..e7b8567b9a2 100644
--- a/tests/ui/type-alias-impl-trait/generic_nondefining_use.rs
+++ b/tests/ui/type-alias-impl-trait/generic_nondefining_use.rs
@@ -19,7 +19,7 @@ fn concrete_ty() -> OneTy<u32> {
 
 fn concrete_lifetime() -> OneLifetime<'static> {
     6u32
-    //~^ ERROR non-defining opaque type use in defining scope
+    //~^ ERROR expected generic lifetime parameter, found `'static`
 }
 
 fn concrete_const() -> OneConst<{ 123 }> {
diff --git a/tests/ui/type-alias-impl-trait/generic_nondefining_use.stderr b/tests/ui/type-alias-impl-trait/generic_nondefining_use.stderr
index 564648630b1..966fe823f02 100644
--- a/tests/ui/type-alias-impl-trait/generic_nondefining_use.stderr
+++ b/tests/ui/type-alias-impl-trait/generic_nondefining_use.stderr
@@ -7,7 +7,7 @@ LL | type OneTy<T> = impl Debug;
 LL |     5u32
    |     ^^^^
 
-error: non-defining opaque type use in defining scope
+error[E0792]: expected generic lifetime parameter, found `'static`
   --> $DIR/generic_nondefining_use.rs:21:5
    |
 LL | type OneLifetime<'a> = impl Debug;
diff --git a/tests/ui/type/type-check/coerce-result-return-value-2.rs b/tests/ui/type/type-check/coerce-result-return-value-2.rs
new file mode 100644
index 00000000000..23bafa6c5c9
--- /dev/null
+++ b/tests/ui/type/type-check/coerce-result-return-value-2.rs
@@ -0,0 +1,24 @@
+struct A;
+struct B;
+impl From<A> for B {
+    fn from(_: A) -> Self { B }
+}
+fn foo4(x: Result<(), A>) -> Result<(), B> {
+    match true {
+        true => x, //~ ERROR mismatched types
+        false => x,
+    }
+}
+fn foo5(x: Result<(), A>) -> Result<(), B> {
+    match true {
+        true => return x, //~ ERROR mismatched types
+        false => return x,
+    }
+}
+fn main() {
+    let _ = foo4(Ok(()));
+    let _ = foo5(Ok(()));
+    let _: Result<(), B> = { //~ ERROR mismatched types
+        Err(A);
+    };
+}
diff --git a/tests/ui/type/type-check/coerce-result-return-value-2.stderr b/tests/ui/type/type-check/coerce-result-return-value-2.stderr
new file mode 100644
index 00000000000..5992162341e
--- /dev/null
+++ b/tests/ui/type/type-check/coerce-result-return-value-2.stderr
@@ -0,0 +1,47 @@
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value-2.rs:8:17
+   |
+LL | fn foo4(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+LL |     match true {
+LL |         true => x,
+   |                 ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |         true => Ok(x?),
+   |                 +++ ++
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value-2.rs:14:24
+   |
+LL | fn foo5(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+LL |     match true {
+LL |         true => return x,
+   |                        ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |         true => return Ok(x?),
+   |                        +++ ++
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value-2.rs:21:28
+   |
+LL |       let _: Result<(), B> = {
+   |  ____________________________^
+LL | |         Err(A);
+LL | |     };
+   | |_____^ expected enum `Result`, found `()`
+   |
+   = note:   expected enum `Result<(), B>`
+           found unit type `()`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/type/type-check/coerce-result-return-value.fixed b/tests/ui/type/type-check/coerce-result-return-value.fixed
new file mode 100644
index 00000000000..8a05407070d
--- /dev/null
+++ b/tests/ui/type/type-check/coerce-result-return-value.fixed
@@ -0,0 +1,24 @@
+// run-rustfix
+struct A;
+struct B;
+impl From<A> for B {
+    fn from(_: A) -> Self { B }
+}
+fn foo1(x: Result<(), A>) -> Result<(), B> {
+    Ok(x?) //~ ERROR mismatched types
+}
+fn foo2(x: Result<(), A>) -> Result<(), B> {
+    return Ok(x?); //~ ERROR mismatched types
+}
+fn foo3(x: Result<(), A>) -> Result<(), B> {
+    if true {
+        Ok(x?) //~ ERROR mismatched types
+    } else {
+        Ok(x?) //~ ERROR mismatched types
+    }
+}
+fn main() {
+    let _ = foo1(Ok(()));
+    let _ = foo2(Ok(()));
+    let _ = foo3(Ok(()));
+}
diff --git a/tests/ui/type/type-check/coerce-result-return-value.rs b/tests/ui/type/type-check/coerce-result-return-value.rs
new file mode 100644
index 00000000000..442203addb7
--- /dev/null
+++ b/tests/ui/type/type-check/coerce-result-return-value.rs
@@ -0,0 +1,24 @@
+// run-rustfix
+struct A;
+struct B;
+impl From<A> for B {
+    fn from(_: A) -> Self { B }
+}
+fn foo1(x: Result<(), A>) -> Result<(), B> {
+    x //~ ERROR mismatched types
+}
+fn foo2(x: Result<(), A>) -> Result<(), B> {
+    return x; //~ ERROR mismatched types
+}
+fn foo3(x: Result<(), A>) -> Result<(), B> {
+    if true {
+        x //~ ERROR mismatched types
+    } else {
+        x //~ ERROR mismatched types
+    }
+}
+fn main() {
+    let _ = foo1(Ok(()));
+    let _ = foo2(Ok(()));
+    let _ = foo3(Ok(()));
+}
diff --git a/tests/ui/type/type-check/coerce-result-return-value.stderr b/tests/ui/type/type-check/coerce-result-return-value.stderr
new file mode 100644
index 00000000000..55015352078
--- /dev/null
+++ b/tests/ui/type/type-check/coerce-result-return-value.stderr
@@ -0,0 +1,65 @@
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value.rs:8:5
+   |
+LL | fn foo1(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+LL |     x
+   |     ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |     Ok(x?)
+   |     +++ ++
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value.rs:11:12
+   |
+LL | fn foo2(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+LL |     return x;
+   |            ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |     return Ok(x?);
+   |            +++ ++
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value.rs:15:9
+   |
+LL | fn foo3(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+LL |     if true {
+LL |         x
+   |         ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |         Ok(x?)
+   |         +++ ++
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-result-return-value.rs:17:9
+   |
+LL | fn foo3(x: Result<(), A>) -> Result<(), B> {
+   |                              ------------- expected `Result<(), B>` because of return type
+...
+LL |         x
+   |         ^ expected struct `B`, found struct `A`
+   |
+   = note: expected enum `Result<_, B>`
+              found enum `Result<_, A>`
+help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
+   |
+LL |         Ok(x?)
+   |         +++ ++
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/typeck/bad-type-in-vec-push.rs b/tests/ui/typeck/bad-type-in-vec-push.rs
new file mode 100644
index 00000000000..a807f030cfc
--- /dev/null
+++ b/tests/ui/typeck/bad-type-in-vec-push.rs
@@ -0,0 +1,20 @@
+// The error message here still is pretty confusing.
+
+fn main() {
+    let mut result = vec![1];
+    // The type of `result` is constrained to be `Vec<{integer}>` here.
+    // But the logic we use to find what expression constrains a type
+    // is not sophisticated enough to know this.
+
+    let mut vector = Vec::new();
+    vector.sort();
+    result.push(vector);
+    //~^ ERROR mismatched types
+    // So it thinks that the type of `result` is constrained here.
+}
+
+fn example2() {
+    let mut x = vec![1];
+    x.push("");
+    //~^ ERROR mismatched types
+}
diff --git a/tests/ui/typeck/bad-type-in-vec-push.stderr b/tests/ui/typeck/bad-type-in-vec-push.stderr
new file mode 100644
index 00000000000..e4c99ec8e70
--- /dev/null
+++ b/tests/ui/typeck/bad-type-in-vec-push.stderr
@@ -0,0 +1,29 @@
+error[E0308]: mismatched types
+  --> $DIR/bad-type-in-vec-push.rs:11:17
+   |
+LL |     vector.sort();
+   |     ------ here the type of `vector` is inferred to be `Vec<_>`
+LL |     result.push(vector);
+   |            ---- ^^^^^^ expected integer, found struct `Vec`
+   |            |
+   |            arguments to this method are incorrect
+   |
+   = note: expected type `{integer}`
+            found struct `Vec<_>`
+note: associated function defined here
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+
+error[E0308]: mismatched types
+  --> $DIR/bad-type-in-vec-push.rs:18:12
+   |
+LL |     x.push("");
+   |       ---- ^^ expected integer, found `&str`
+   |       |
+   |       arguments to this method are incorrect
+   |
+note: associated function defined here
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/typeck/issue-107087.rs b/tests/ui/typeck/issue-107087.rs
new file mode 100644
index 00000000000..135cdf19e3e
--- /dev/null
+++ b/tests/ui/typeck/issue-107087.rs
@@ -0,0 +1,18 @@
+struct A<T>(T);
+
+trait Foo {
+    type B;
+}
+
+impl Foo for A<u32> {
+    type B = i32;
+}
+
+impl Foo for A<i32> {
+    type B = i32;
+}
+
+fn main() {
+    A::B::<>::C
+    //~^ ERROR ambiguous associated type
+}
diff --git a/tests/ui/typeck/issue-107087.stderr b/tests/ui/typeck/issue-107087.stderr
new file mode 100644
index 00000000000..70f19320802
--- /dev/null
+++ b/tests/ui/typeck/issue-107087.stderr
@@ -0,0 +1,9 @@
+error[E0223]: ambiguous associated type
+  --> $DIR/issue-107087.rs:16:5
+   |
+LL |     A::B::<>::C
+   |     ^^^^^^^^ help: use the fully-qualified path: `<A<_> as Foo>::B`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0223`.
diff --git a/tests/ui/typeck/issue-91334.stderr b/tests/ui/typeck/issue-91334.stderr
index 8508f7a38e2..78f392c9a8a 100644
--- a/tests/ui/typeck/issue-91334.stderr
+++ b/tests/ui/typeck/issue-91334.stderr
@@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-91334.rs:10:23
    |
 LL | fn f(){||yield(((){),
-   |       -       -       ^
-   |       |       |
+   |       -       -    -  ^
+   |       |       |    |
+   |       |       |    missing open `(` for this delimiter
    |       |       unclosed delimiter
    |       unclosed delimiter
 
@@ -11,8 +12,9 @@ error: this file contains an unclosed delimiter
   --> $DIR/issue-91334.rs:10:23
    |
 LL | fn f(){||yield(((){),
-   |       -       -       ^
-   |       |       |
+   |       -       -    -  ^
+   |       |       |    |
+   |       |       |    missing open `(` for this delimiter
    |       |       unclosed delimiter
    |       unclosed delimiter
 
diff --git a/tests/ui/unboxed-closures/unboxed-closures-borrow-conflict.stderr b/tests/ui/unboxed-closures/unboxed-closures-borrow-conflict.stderr
index 21d6b4fde7e..98fe97c5c18 100644
--- a/tests/ui/unboxed-closures/unboxed-closures-borrow-conflict.stderr
+++ b/tests/ui/unboxed-closures/unboxed-closures-borrow-conflict.stderr
@@ -4,7 +4,7 @@ error[E0503]: cannot use `x` because it was mutably borrowed
 LL |     let f = || x += 1;
    |             -- - borrow occurs due to use of `x` in closure
    |             |
-   |             borrow of `x` occurs here
+   |             `x` is borrowed here
 LL |     let _y = x;
    |              ^ use of borrowed `x`
 LL |     f;
diff --git a/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.stderr b/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.stderr
index cbdb4dd0fb5..23aa18d7156 100644
--- a/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.stderr
+++ b/tests/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.stderr
@@ -16,14 +16,14 @@ error[E0506]: cannot assign to `factorial` because it is borrowed
   --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:20:5
    |
 LL |     let f = |x: u32| -> u32 {
-   |             --------------- borrow of `factorial` occurs here
+   |             --------------- `factorial` is borrowed here
 LL |         let g = factorial.as_ref().unwrap();
    |                 --------- borrow occurs due to use in closure
 ...
 LL |     factorial = Some(Box::new(f));
    |     ^^^^^^^^^
    |     |
-   |     assignment to borrowed `factorial` occurs here
+   |     `factorial` is assigned to here but it was already borrowed
    |     borrow later used here
 
 error[E0597]: `factorial` does not live long enough
@@ -47,12 +47,12 @@ LL |     let mut factorial: Option<Box<dyn Fn(u32) -> u32 + 'static>> = None;
    |                        ----------------------------------------- type annotation requires that `factorial` is borrowed for `'static`
 LL |
 LL |     let f = |x: u32| -> u32 {
-   |             --------------- borrow of `factorial` occurs here
+   |             --------------- `factorial` is borrowed here
 LL |         let g = factorial.as_ref().unwrap();
    |                 --------- borrow occurs due to use in closure
 ...
 LL |     factorial = Some(Box::new(f));
-   |     ^^^^^^^^^ assignment to borrowed `factorial` occurs here
+   |     ^^^^^^^^^ `factorial` is assigned to here but it was already borrowed
 
 error: aborting due to 4 previous errors
 
diff --git a/tests/ui/unop-move-semantics.stderr b/tests/ui/unop-move-semantics.stderr
index 2a3ca14433f..e47785c465a 100644
--- a/tests/ui/unop-move-semantics.stderr
+++ b/tests/ui/unop-move-semantics.stderr
@@ -23,6 +23,8 @@ LL | fn move_then_borrow<T: Not<Output=T> + Clone + Copy>(x: T) {
 error[E0505]: cannot move out of `x` because it is borrowed
   --> $DIR/unop-move-semantics.rs:15:6
    |
+LL | fn move_borrowed<T: Not<Output=T>>(x: T, mut y: T) {
+   |                                    - binding `x` declared here
 LL |     let m = &x;
    |             -- borrow of `x` occurs here
 ...
@@ -35,6 +37,9 @@ LL |     use_mut(n); use_imm(m);
 error[E0505]: cannot move out of `y` because it is borrowed
   --> $DIR/unop-move-semantics.rs:17:6
    |
+LL | fn move_borrowed<T: Not<Output=T>>(x: T, mut y: T) {
+   |                                          ----- binding `y` declared here
+LL |     let m = &x;
 LL |     let n = &mut y;
    |             ------ borrow of `y` occurs here
 ...
diff --git a/tests/ui/variance/variance-associated-types.rs b/tests/ui/variance/variance-associated-types.rs
index 1165fb53c73..ecb0821827d 100644
--- a/tests/ui/variance/variance-associated-types.rs
+++ b/tests/ui/variance/variance-associated-types.rs
@@ -10,7 +10,7 @@ trait Trait<'a> {
 }
 
 #[rustc_variance]
-struct Foo<'a, T : Trait<'a>> { //~ ERROR [-, +]
+struct Foo<'a, T : Trait<'a>> { //~ ERROR [+, +]
     field: (T, &'a ())
 }
 
diff --git a/tests/ui/variance/variance-associated-types.stderr b/tests/ui/variance/variance-associated-types.stderr
index 51f17c7c228..70cb246f6e9 100644
--- a/tests/ui/variance/variance-associated-types.stderr
+++ b/tests/ui/variance/variance-associated-types.stderr
@@ -1,4 +1,4 @@
-error: [-, +]
+error: [+, +]
   --> $DIR/variance-associated-types.rs:13:1
    |
 LL | struct Foo<'a, T : Trait<'a>> {
diff --git a/tests/ui/variance/variance-issue-20533.stderr b/tests/ui/variance/variance-issue-20533.stderr
index 008e2a002bb..258f67db5ce 100644
--- a/tests/ui/variance/variance-issue-20533.stderr
+++ b/tests/ui/variance/variance-issue-20533.stderr
@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/variance-issue-20533.rs:28:14
    |
+LL |         let a = AffineU32(1);
+   |             - binding `a` declared here
 LL |         let x = foo(&a);
    |                     -- borrow of `a` occurs here
 LL |         drop(a);
@@ -11,6 +13,8 @@ LL |         drop(x);
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/variance-issue-20533.rs:34:14
    |
+LL |         let a = AffineU32(1);
+   |             - binding `a` declared here
 LL |         let x = bar(&a);
    |                     -- borrow of `a` occurs here
 LL |         drop(a);
@@ -21,6 +25,8 @@ LL |         drop(x);
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/variance-issue-20533.rs:40:14
    |
+LL |         let a = AffineU32(1);
+   |             - binding `a` declared here
 LL |         let x = baz(&a);
    |                     -- borrow of `a` occurs here
 LL |         drop(a);
diff --git a/tests/ui/variance/variance-regions-direct.rs b/tests/ui/variance/variance-regions-direct.rs
index 3f34e7655f3..39ea77a8aa2 100644
--- a/tests/ui/variance/variance-regions-direct.rs
+++ b/tests/ui/variance/variance-regions-direct.rs
@@ -6,7 +6,7 @@
 // Regions that just appear in normal spots are contravariant:
 
 #[rustc_variance]
-struct Test2<'a, 'b, 'c> { //~ ERROR [-, -, -]
+struct Test2<'a, 'b, 'c> { //~ ERROR [+, +, +]
     x: &'a isize,
     y: &'b [isize],
     c: &'c str
@@ -15,7 +15,7 @@ struct Test2<'a, 'b, 'c> { //~ ERROR [-, -, -]
 // Those same annotations in function arguments become covariant:
 
 #[rustc_variance]
-struct Test3<'a, 'b, 'c> { //~ ERROR [+, +, +]
+struct Test3<'a, 'b, 'c> { //~ ERROR [-, -, -]
     x: extern "Rust" fn(&'a isize),
     y: extern "Rust" fn(&'b [isize]),
     c: extern "Rust" fn(&'c str),
@@ -24,7 +24,7 @@ struct Test3<'a, 'b, 'c> { //~ ERROR [+, +, +]
 // Mutability induces invariance:
 
 #[rustc_variance]
-struct Test4<'a, 'b:'a> { //~ ERROR [-, o]
+struct Test4<'a, 'b:'a> { //~ ERROR [+, o]
     x: &'a mut &'b isize,
 }
 
@@ -32,7 +32,7 @@ struct Test4<'a, 'b:'a> { //~ ERROR [-, o]
 // contravariant context:
 
 #[rustc_variance]
-struct Test5<'a, 'b:'a> { //~ ERROR [+, o]
+struct Test5<'a, 'b:'a> { //~ ERROR [-, o]
     x: extern "Rust" fn(&'a mut &'b isize),
 }
 
@@ -42,7 +42,7 @@ struct Test5<'a, 'b:'a> { //~ ERROR [+, o]
 // argument list occurs in an invariant context.
 
 #[rustc_variance]
-struct Test6<'a, 'b:'a> { //~ ERROR [-, o]
+struct Test6<'a, 'b:'a> { //~ ERROR [+, o]
     x: &'a mut extern "Rust" fn(&'b isize),
 }
 
@@ -56,7 +56,7 @@ struct Test7<'a> { //~ ERROR [*]
 // Try enums too.
 
 #[rustc_variance]
-enum Test8<'a, 'b, 'c:'b> { //~ ERROR [+, -, o]
+enum Test8<'a, 'b, 'c:'b> { //~ ERROR [-, +, o]
     Test8A(extern "Rust" fn(&'a isize)),
     Test8B(&'b [isize]),
     Test8C(&'b mut &'c str),
diff --git a/tests/ui/variance/variance-regions-direct.stderr b/tests/ui/variance/variance-regions-direct.stderr
index eda02e9b03b..c55730296f1 100644
--- a/tests/ui/variance/variance-regions-direct.stderr
+++ b/tests/ui/variance/variance-regions-direct.stderr
@@ -1,28 +1,28 @@
-error: [-, -, -]
+error: [+, +, +]
   --> $DIR/variance-regions-direct.rs:9:1
    |
 LL | struct Test2<'a, 'b, 'c> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [+, +, +]
+error: [-, -, -]
   --> $DIR/variance-regions-direct.rs:18:1
    |
 LL | struct Test3<'a, 'b, 'c> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [-, o]
+error: [+, o]
   --> $DIR/variance-regions-direct.rs:27:1
    |
 LL | struct Test4<'a, 'b:'a> {
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [+, o]
+error: [-, o]
   --> $DIR/variance-regions-direct.rs:35:1
    |
 LL | struct Test5<'a, 'b:'a> {
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [-, o]
+error: [+, o]
   --> $DIR/variance-regions-direct.rs:45:1
    |
 LL | struct Test6<'a, 'b:'a> {
@@ -34,7 +34,7 @@ error: [*]
 LL | struct Test7<'a> {
    | ^^^^^^^^^^^^^^^^
 
-error: [+, -, o]
+error: [-, +, o]
   --> $DIR/variance-regions-direct.rs:59:1
    |
 LL | enum Test8<'a, 'b, 'c:'b> {
diff --git a/tests/ui/variance/variance-regions-indirect.rs b/tests/ui/variance/variance-regions-indirect.rs
index f84f25ada14..0d00535fef1 100644
--- a/tests/ui/variance/variance-regions-indirect.rs
+++ b/tests/ui/variance/variance-regions-indirect.rs
@@ -5,14 +5,14 @@
 #![feature(rustc_attrs)]
 
 #[rustc_variance]
-enum Base<'a, 'b, 'c:'b, 'd> { //~ ERROR [+, -, o, *]
+enum Base<'a, 'b, 'c:'b, 'd> { //~ ERROR [-, +, o, *]
     Test8A(extern "Rust" fn(&'a isize)),
     Test8B(&'b [isize]),
     Test8C(&'b mut &'c str),
 }
 
 #[rustc_variance]
-struct Derived1<'w, 'x:'y, 'y, 'z> { //~ ERROR [*, o, -, +]
+struct Derived1<'w, 'x:'y, 'y, 'z> { //~ ERROR [*, o, +, -]
     f: Base<'z, 'y, 'x, 'w>
 }
 
@@ -22,12 +22,12 @@ struct Derived2<'a, 'b:'a, 'c> { //~ ERROR [o, o, *]
 }
 
 #[rustc_variance] // Combine + and o to yield o (just pay attention to 'a here)
-struct Derived3<'a:'b, 'b, 'c> { //~ ERROR [o, -, *]
+struct Derived3<'a:'b, 'b, 'c> { //~ ERROR [o, +, *]
     f: Base<'a, 'b, 'a, 'c>
 }
 
 #[rustc_variance] // Combine + and * to yield + (just pay attention to 'a here)
-struct Derived4<'a, 'b, 'c:'b> { //~ ERROR [+, -, o]
+struct Derived4<'a, 'b, 'c:'b> { //~ ERROR [-, +, o]
     f: Base<'a, 'b, 'c, 'a>
 }
 
diff --git a/tests/ui/variance/variance-regions-indirect.stderr b/tests/ui/variance/variance-regions-indirect.stderr
index fa2f4d507f3..edf2626d598 100644
--- a/tests/ui/variance/variance-regions-indirect.stderr
+++ b/tests/ui/variance/variance-regions-indirect.stderr
@@ -1,10 +1,10 @@
-error: [+, -, o, *]
+error: [-, +, o, *]
   --> $DIR/variance-regions-indirect.rs:8:1
    |
 LL | enum Base<'a, 'b, 'c:'b, 'd> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [*, o, -, +]
+error: [*, o, +, -]
   --> $DIR/variance-regions-indirect.rs:15:1
    |
 LL | struct Derived1<'w, 'x:'y, 'y, 'z> {
@@ -16,13 +16,13 @@ error: [o, o, *]
 LL | struct Derived2<'a, 'b:'a, 'c> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [o, -, *]
+error: [o, +, *]
   --> $DIR/variance-regions-indirect.rs:25:1
    |
 LL | struct Derived3<'a:'b, 'b, 'c> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: [+, -, o]
+error: [-, +, o]
   --> $DIR/variance-regions-indirect.rs:30:1
    |
 LL | struct Derived4<'a, 'b, 'c:'b> {
diff --git a/tests/ui/variance/variance-trait-object-bound.rs b/tests/ui/variance/variance-trait-object-bound.rs
index ec3c973bc76..11303c46520 100644
--- a/tests/ui/variance/variance-trait-object-bound.rs
+++ b/tests/ui/variance/variance-trait-object-bound.rs
@@ -11,7 +11,7 @@ use std::mem;
 trait T { fn foo(&self); }
 
 #[rustc_variance]
-struct TOption<'a> { //~ ERROR [-]
+struct TOption<'a> { //~ ERROR [+]
     v: Option<Box<dyn T + 'a>>,
 }
 
diff --git a/tests/ui/variance/variance-trait-object-bound.stderr b/tests/ui/variance/variance-trait-object-bound.stderr
index 7c46b553f43..bfcc8d4a1d1 100644
--- a/tests/ui/variance/variance-trait-object-bound.stderr
+++ b/tests/ui/variance/variance-trait-object-bound.stderr
@@ -1,4 +1,4 @@
-error: [-]
+error: [+]
   --> $DIR/variance-trait-object-bound.rs:14:1
    |
 LL | struct TOption<'a> {
diff --git a/tests/ui/variance/variance-types.rs b/tests/ui/variance/variance-types.rs
index b9b6d9c9bb5..cfc03b75473 100644
--- a/tests/ui/variance/variance-types.rs
+++ b/tests/ui/variance/variance-types.rs
@@ -7,7 +7,7 @@ use std::cell::Cell;
 // not considered bivariant.
 
 #[rustc_variance]
-struct InvariantMut<'a,A:'a,B:'a> { //~ ERROR [-, o, o]
+struct InvariantMut<'a,A:'a,B:'a> { //~ ERROR [+, o, o]
     t: &'a mut (A,B)
 }
 
diff --git a/tests/ui/variance/variance-types.stderr b/tests/ui/variance/variance-types.stderr
index 9f7f1d9b0e3..0fda4b8036e 100644
--- a/tests/ui/variance/variance-types.stderr
+++ b/tests/ui/variance/variance-types.stderr
@@ -1,4 +1,4 @@
-error: [-, o, o]
+error: [+, o, o]
   --> $DIR/variance-types.rs:10:1
    |
 LL | struct InvariantMut<'a,A:'a,B:'a> {
diff --git a/triagebot.toml b/triagebot.toml
index 16a31321513..79958729fc5 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -456,6 +456,9 @@ These commits modify **compiler targets**.
 (See the [Target Tier Policy](https://doc.rust-lang.org/nightly/rustc/target-tier-policy.html).)
 """
 
+[mentions."src/doc/style-guide"]
+cc = ["@rust-lang/style"]
+
 [assign]
 warn_non_default_branch = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/contributing.html"
@@ -560,6 +563,12 @@ ast_lowering = [
 fallback = [
     "@Mark-Simulacrum"
 ]
+style-team = [
+    "@calebcartwright",
+    "@compiler-errors",
+    "@joshtriplett",
+    "@yaahc",
+]
 
 [assign.owners]
 "/.github/workflows" =                       ["infra-ci"]
@@ -604,6 +613,7 @@ fallback = [
 "/src/doc/rust-by-example" =                 ["@ehuss"]
 "/src/doc/rustc-dev-guide" =                 ["@ehuss"]
 "/src/doc/rustdoc" =                         ["rustdoc"]
+"/src/doc/style-guide" =                     ["style-team"]
 "/src/etc" =                                 ["@Mark-Simulacrum"]
 "/src/librustdoc" =                          ["rustdoc"]
 "/src/llvm-project" =                        ["@cuviper"]