Merge from rustc

96 files changed, 1158 insertions, 1192 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 6b51cbd7fbe..4489a424c0d 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -1450,11 +1450,20 @@ impl Expr {
     }
 
     pub fn precedence(&self) -> ExprPrecedence {
+        fn prefix_attrs_precedence(attrs: &AttrVec) -> ExprPrecedence {
+            for attr in attrs {
+                if let AttrStyle::Outer = attr.style {
+                    return ExprPrecedence::Prefix;
+                }
+            }
+            ExprPrecedence::Unambiguous
+        }
+
         match &self.kind {
             ExprKind::Closure(closure) => {
                 match closure.fn_decl.output {
                     FnRetTy::Default(_) => ExprPrecedence::Jump,
-                    FnRetTy::Ty(_) => ExprPrecedence::Unambiguous,
+                    FnRetTy::Ty(_) => prefix_attrs_precedence(&self.attrs),
                 }
             }
 
@@ -1463,7 +1472,7 @@ impl Expr {
             | ExprKind::Yield(YieldKind::Prefix(value))
             | ExprKind::Yeet(value) => match value {
                 Some(_) => ExprPrecedence::Jump,
-                None => ExprPrecedence::Unambiguous,
+                None => prefix_attrs_precedence(&self.attrs),
             },
 
             ExprKind::Become(_) => ExprPrecedence::Jump,
@@ -1490,7 +1499,7 @@ impl Expr {
             | ExprKind::Let(..)
             | ExprKind::Unary(..) => ExprPrecedence::Prefix,
 
-            // Never need parens
+            // Need parens if and only if there are prefix attributes.
             ExprKind::Array(_)
             | ExprKind::Await(..)
             | ExprKind::Use(..)
@@ -1525,7 +1534,7 @@ impl Expr {
             | ExprKind::While(..)
             | ExprKind::Yield(YieldKind::Postfix(..))
             | ExprKind::Err(_)
-            | ExprKind::Dummy => ExprPrecedence::Unambiguous,
+            | ExprKind::Dummy => prefix_attrs_precedence(&self.attrs),
         }
     }
 
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index c88aa5c33ea..1449a4a5fb3 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -1700,7 +1700,8 @@ fn visit_nested_use_tree<'a, V: Visitor<'a>>(
 }
 
 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) -> V::Result {
-    let Stmt { id: _, kind, span: _ } = statement;
+    let Stmt { id, kind, span: _ } = statement;
+    try_visit!(visit_id(visitor, id));
     match kind {
         StmtKind::Let(local) => try_visit!(visitor.visit_local(local)),
         StmtKind::Item(item) => try_visit!(visitor.visit_item(item)),
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index e2d291a536d..49110c93954 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -145,6 +145,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             vis_span,
             span: self.lower_span(i.span),
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -599,6 +600,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                             kind,
                             vis_span,
                             span: this.lower_span(use_tree.span),
+                            has_delayed_lints: !this.delayed_lints.is_empty(),
                         };
                         hir::OwnerNode::Item(this.arena.alloc(item))
                     });
@@ -697,6 +699,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             vis_span: self.lower_span(i.vis.span),
             span: self.lower_span(i.span),
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -941,6 +944,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             kind,
             span: self.lower_span(i.span),
             defaultness: hir::Defaultness::Default { has_value: has_default },
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
@@ -1100,6 +1104,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             vis_span: self.lower_span(i.vis.span),
             span: self.lower_span(i.span),
             defaultness,
+            has_delayed_lints: !self.delayed_lints.is_empty(),
         };
         self.arena.alloc(item)
     }
diff --git a/compiler/rustc_attr_data_structures/src/attributes.rs b/compiler/rustc_attr_data_structures/src/attributes.rs
index 845e4d5e5d0..8f95a017809 100644
--- a/compiler/rustc_attr_data_structures/src/attributes.rs
+++ b/compiler/rustc_attr_data_structures/src/attributes.rs
@@ -130,24 +130,54 @@ impl Deprecation {
     }
 }
 
-/// Represent parsed, *built in*, inert attributes.
+/// Represents parsed *built-in* inert attributes.
 ///
-/// That means attributes that are not actually ever expanded.
-/// For more information on this, see the module docs on the [`rustc_attr_parsing`] crate.
-/// They're instead used as markers, to guide the compilation process in various way in most every stage of the compiler.
-/// These are kept around after the AST, into the HIR and further on.
+/// ## Overview
+/// These attributes are markers that guide the compilation process and are never expanded into other code.
+/// They persist throughout the compilation phases, from AST to HIR and beyond.
 ///
-/// The word "parsed" could be a little misleading here, because the parser already parses
-/// attributes early on. However, the result, an [`ast::Attribute`]
-/// is only parsed at a high level, still containing a token stream in many cases. That is
-/// because the structure of the contents varies from attribute to attribute.
-/// With a parsed attribute I mean that each attribute is processed individually into a
-/// final structure, which on-site (the place where the attribute is useful for, think the
-/// the place where `must_use` is checked) little to no extra parsing or validating needs to
-/// happen.
+/// ## Attribute Processing
+/// While attributes are initially parsed by [`rustc_parse`] into [`ast::Attribute`], they still contain raw token streams
+/// because different attributes have different internal structures. This enum represents the final,
+/// fully parsed form of these attributes, where each variant contains contains all the information and
+/// structure relevant for the specific attribute.
 ///
-/// For more docs, look in [`rustc_attr_parsing`].
+/// Some attributes can be applied multiple times to the same item, and they are "collapsed" into a single
+/// semantic attribute. For example:
+/// ```rust
+/// #[repr(C)]
+/// #[repr(packed)]
+/// struct S { }
+/// ```
+/// This is equivalent to `#[repr(C, packed)]` and results in a single [`AttributeKind::Repr`] containing
+/// both `C` and `packed` annotations. This collapsing happens during parsing and is reflected in the
+/// data structures defined in this enum.
 ///
+/// ## Usage
+/// These parsed attributes are used throughout the compiler to:
+/// - Control code generation (e.g., `#[repr]`)
+/// - Mark API stability (`#[stable]`, `#[unstable]`)
+/// - Provide documentation (`#[doc]`)
+/// - Guide compiler behavior (e.g., `#[allow_internal_unstable]`)
+///
+/// ## Note on Attribute Organization
+/// Some attributes like `InlineAttr`, `OptimizeAttr`, and `InstructionSetAttr` are defined separately
+/// from this enum because they are used in specific compiler phases (like code generation) and don't
+/// need to persist throughout the entire compilation process. They are typically processed and
+/// converted into their final form earlier in the compilation pipeline.
+///
+/// For example:
+/// - `InlineAttr` is used during code generation to control function inlining
+/// - `OptimizeAttr` is used to control optimization levels
+/// - `InstructionSetAttr` is used for target-specific code generation
+///
+/// These attributes are handled by their respective compiler passes in the [`rustc_codegen_ssa`] crate
+/// and don't need to be preserved in the same way as the attributes in this enum.
+///
+/// For more details on attribute parsing, see the [`rustc_attr_parsing`] crate.
+///
+/// [`rustc_parse`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/index.html
+/// [`rustc_codegen_ssa`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_codegen_ssa/index.html
 /// [`rustc_attr_parsing`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_attr_parsing/index.html
 #[derive(Clone, Debug, HashStable_Generic, Encodable, Decodable, PrintAttribute)]
 pub enum AttributeKind {
@@ -158,6 +188,9 @@ pub enum AttributeKind {
     /// Represents `#[allow_internal_unstable]`.
     AllowInternalUnstable(ThinVec<(Symbol, Span)>),
 
+    /// Represents `#[rustc_as_ptr]` (used by the `dangling_pointers_from_temporaries` lint).
+    AsPtr(Span),
+
     /// Represents `#[rustc_default_body_unstable]`.
     BodyStability {
         stability: DefaultBodyStability,
diff --git a/compiler/rustc_attr_data_structures/src/lib.rs b/compiler/rustc_attr_data_structures/src/lib.rs
index b0fc19d1cd7..f8355be09ad 100644
--- a/compiler/rustc_attr_data_structures/src/lib.rs
+++ b/compiler/rustc_attr_data_structures/src/lib.rs
@@ -1,3 +1,7 @@
+//! Data structures for representing parsed attributes in the Rust compiler.
+//! For detailed documentation about attribute processing,
+//! see [rustc_attr_parsing](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_attr_parsing/index.html).
+
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![doc(rust_logo)]
diff --git a/compiler/rustc_attr_parsing/src/attributes/lint_helpers.rs b/compiler/rustc_attr_parsing/src/attributes/lint_helpers.rs
new file mode 100644
index 00000000000..32a20d4c5b5
--- /dev/null
+++ b/compiler/rustc_attr_parsing/src/attributes/lint_helpers.rs
@@ -0,0 +1,21 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_span::{Symbol, sym};
+
+use crate::attributes::{AttributeOrder, OnDuplicate, SingleAttributeParser};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct AsPtrParser;
+
+impl<S: Stage> SingleAttributeParser<S> for AsPtrParser {
+    const PATH: &[Symbol] = &[sym::rustc_as_ptr];
+
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst;
+
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, _args: &ArgParser<'_>) -> Option<AttributeKind> {
+        // FIXME: check that there's no args (this is currently checked elsewhere)
+        Some(AttributeKind::AsPtr(cx.attr_span))
+    }
+}
diff --git a/compiler/rustc_attr_parsing/src/attributes/mod.rs b/compiler/rustc_attr_parsing/src/attributes/mod.rs
index caf55e6685e..df488c89a34 100644
--- a/compiler/rustc_attr_parsing/src/attributes/mod.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/mod.rs
@@ -29,6 +29,7 @@ pub(crate) mod allow_unstable;
 pub(crate) mod cfg;
 pub(crate) mod confusables;
 pub(crate) mod deprecation;
+pub(crate) mod lint_helpers;
 pub(crate) mod repr;
 pub(crate) mod stability;
 pub(crate) mod transparency;
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 47f72232828..3193d8975e9 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -18,6 +18,7 @@ use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
+use crate::attributes::lint_helpers::AsPtrParser;
 use crate::attributes::repr::ReprParser;
 use crate::attributes::stability::{
     BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
@@ -102,6 +103,7 @@ attribute_parsers!(
         // tidy-alphabetical-end
 
         // tidy-alphabetical-start
+        Single<AsPtrParser>,
         Single<ConstStabilityIndirectParser>,
         Single<DeprecationParser>,
         Single<TransparencyParser>,
diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs
index 7511a55b03a..57db2e9fb57 100644
--- a/compiler/rustc_borrowck/src/dataflow.rs
+++ b/compiler/rustc_borrowck/src/dataflow.rs
@@ -2,7 +2,7 @@ use std::fmt;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::graph;
-use rustc_index::bit_set::DenseBitSet;
+use rustc_index::bit_set::{DenseBitSet, MixedBitSet};
 use rustc_middle::mir::{
     self, BasicBlock, Body, CallReturnPlaces, Location, Place, TerminatorEdges,
 };
@@ -548,7 +548,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     }
 }
 
-type BorrowsDomain = DenseBitSet<BorrowIndex>;
+type BorrowsDomain = MixedBitSet<BorrowIndex>;
 
 /// Forward dataflow computation of the set of borrows that are in scope at a particular location.
 /// - we gen the introduced loans
@@ -564,7 +564,7 @@ impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
 
     fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
         // bottom = nothing is reserved or activated yet;
-        DenseBitSet::new_empty(self.borrow_set.len())
+        MixedBitSet::new_empty(self.borrow_set.len())
     }
 
     fn initialize_start_block(&self, _: &mir::Body<'tcx>, _: &mut Self::Domain) {
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index a845431faca..c4b0f503664 100644
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@@ -342,6 +342,10 @@ impl<'tcx> BorrowExplanation<'tcx> {
                                 }
                             }
                         } else if let LocalInfo::BlockTailTemp(info) = local_decl.local_info() {
+                            let sp = info
+                                .span
+                                .find_ancestor_in_same_ctxt(local_decl.source_info.span)
+                                .unwrap_or(info.span);
                             if info.tail_result_is_ignored {
                                 // #85581: If the first mutable borrow's scope contains
                                 // the second borrow, this suggestion isn't helpful.
@@ -349,7 +353,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                                     old.to(info.span.shrink_to_hi()).contains(new)
                                 }) {
                                     err.span_suggestion_verbose(
-                                        info.span.shrink_to_hi(),
+                                        sp.shrink_to_hi(),
                                         "consider adding semicolon after the expression so its \
                                         temporaries are dropped sooner, before the local variables \
                                         declared by the block are dropped",
@@ -368,8 +372,8 @@ impl<'tcx> BorrowExplanation<'tcx> {
                                      local variable `x` and then make `x` be the expression at the \
                                      end of the block",
                                     vec![
-                                        (info.span.shrink_to_lo(), "let x = ".to_string()),
-                                        (info.span.shrink_to_hi(), "; x".to_string()),
+                                        (sp.shrink_to_lo(), "let x = ".to_string()),
+                                        (sp.shrink_to_hi(), "; x".to_string()),
                                     ],
                                     Applicability::MaybeIncorrect,
                                 );
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index e6eae7d4f5a..4d85f109020 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -29,7 +29,7 @@ use rustc_errors::LintDiagnostic;
 use rustc_hir as hir;
 use rustc_hir::CRATE_HIR_ID;
 use rustc_hir::def_id::LocalDefId;
-use rustc_index::bit_set::{DenseBitSet, MixedBitSet};
+use rustc_index::bit_set::MixedBitSet;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_infer::infer::{
     InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin, TyCtxtInferExt,
@@ -1151,11 +1151,11 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         &self,
         location: Location,
         state: &'s BorrowckDomain,
-    ) -> Cow<'s, DenseBitSet<BorrowIndex>> {
+    ) -> Cow<'s, MixedBitSet<BorrowIndex>> {
         if let Some(polonius) = &self.polonius_output {
             // Use polonius output if it has been enabled.
             let location = self.location_table.start_index(location);
-            let mut polonius_output = DenseBitSet::new_empty(self.borrow_set.len());
+            let mut polonius_output = MixedBitSet::new_empty(self.borrow_set.len());
             for &idx in polonius.errors_at(location) {
                 polonius_output.insert(idx);
             }
diff --git a/compiler/rustc_builtin_macros/src/test.rs b/compiler/rustc_builtin_macros/src/test.rs
index b439fa34f5b..b067578794b 100644
--- a/compiler/rustc_builtin_macros/src/test.rs
+++ b/compiler/rustc_builtin_macros/src/test.rs
@@ -118,10 +118,7 @@ pub(crate) fn expand_test_or_bench(
 
     let (item, is_stmt) = match item {
         Annotatable::Item(i) => (i, false),
-        Annotatable::Stmt(stmt) if matches!(stmt.kind, ast::StmtKind::Item(_)) => {
-            // FIXME: Use an 'if let' guard once they are implemented
-            if let ast::StmtKind::Item(i) = stmt.kind { (i, true) } else { unreachable!() }
-        }
+        Annotatable::Stmt(box ast::Stmt { kind: ast::StmtKind::Item(i), .. }) => (i, true),
         other => {
             not_testable_error(cx, attr_sp, None);
             return vec![other];
diff --git a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs
index 6d8614aca69..cd0afee0cfb 100644
--- a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs
+++ b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs
@@ -1,6 +1,6 @@
 //! Argument passing
 
-use cranelift_codegen::ir::{ArgumentExtension, ArgumentPurpose};
+use cranelift_codegen::ir::ArgumentPurpose;
 use rustc_abi::{Reg, RegKind};
 use rustc_target::callconv::{
     ArgAbi, ArgAttributes, ArgExtension as RustcArgExtension, CastTarget, PassMode,
@@ -32,16 +32,26 @@ fn reg_to_abi_param(reg: Reg) -> AbiParam {
     AbiParam::new(clif_ty)
 }
 
-fn apply_arg_attrs_to_abi_param(mut param: AbiParam, arg_attrs: ArgAttributes) -> AbiParam {
+fn apply_attrs_to_abi_param(param: AbiParam, arg_attrs: ArgAttributes) -> AbiParam {
     match arg_attrs.arg_ext {
-        RustcArgExtension::None => {}
-        RustcArgExtension::Zext => param.extension = ArgumentExtension::Uext,
-        RustcArgExtension::Sext => param.extension = ArgumentExtension::Sext,
+        RustcArgExtension::None => param,
+        RustcArgExtension::Zext => param.uext(),
+        RustcArgExtension::Sext => param.sext(),
     }
-    param
 }
 
-fn cast_target_to_abi_params(cast: &CastTarget) -> SmallVec<[AbiParam; 2]> {
+fn cast_target_to_abi_params(cast: &CastTarget) -> SmallVec<[(Size, AbiParam); 2]> {
+    if let Some(offset_from_start) = cast.rest_offset {
+        assert!(cast.prefix[1..].iter().all(|p| p.is_none()));
+        assert_eq!(cast.rest.unit.size, cast.rest.total);
+        let first = cast.prefix[0].unwrap();
+        let second = cast.rest.unit;
+        return smallvec![
+            (Size::ZERO, reg_to_abi_param(first)),
+            (offset_from_start, reg_to_abi_param(second))
+        ];
+    }
+
     let (rest_count, rem_bytes) = if cast.rest.unit.size.bytes() == 0 {
         (0, 0)
     } else {
@@ -56,25 +66,32 @@ fn cast_target_to_abi_params(cast: &CastTarget) -> SmallVec<[AbiParam; 2]> {
     // different types in Cranelift IR. Instead a single array of primitive types is used.
 
     // Create list of fields in the main structure
-    let mut args = cast
+    let args = cast
         .prefix
         .iter()
         .flatten()
         .map(|&reg| reg_to_abi_param(reg))
-        .chain((0..rest_count).map(|_| reg_to_abi_param(cast.rest.unit)))
-        .collect::<SmallVec<_>>();
+        .chain((0..rest_count).map(|_| reg_to_abi_param(cast.rest.unit)));
+
+    let mut res = SmallVec::new();
+    let mut offset = Size::ZERO;
+
+    for arg in args {
+        res.push((offset, arg));
+        offset += Size::from_bytes(arg.value_type.bytes());
+    }
 
     // Append final integer
     if rem_bytes != 0 {
         // Only integers can be really split further.
         assert_eq!(cast.rest.unit.kind, RegKind::Integer);
-        args.push(reg_to_abi_param(Reg {
-            kind: RegKind::Integer,
-            size: Size::from_bytes(rem_bytes),
-        }));
+        res.push((
+            offset,
+            reg_to_abi_param(Reg { kind: RegKind::Integer, size: Size::from_bytes(rem_bytes) }),
+        ));
     }
 
-    args
+    res
 }
 
 impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
@@ -82,7 +99,7 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
         match self.mode {
             PassMode::Ignore => smallvec![],
             PassMode::Direct(attrs) => match self.layout.backend_repr {
-                BackendRepr::Scalar(scalar) => smallvec![apply_arg_attrs_to_abi_param(
+                BackendRepr::Scalar(scalar) => smallvec![apply_attrs_to_abi_param(
                     AbiParam::new(scalar_to_clif_type(tcx, scalar)),
                     attrs
                 )],
@@ -97,34 +114,34 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                     let a = scalar_to_clif_type(tcx, a);
                     let b = scalar_to_clif_type(tcx, b);
                     smallvec![
-                        apply_arg_attrs_to_abi_param(AbiParam::new(a), attrs_a),
-                        apply_arg_attrs_to_abi_param(AbiParam::new(b), attrs_b),
+                        apply_attrs_to_abi_param(AbiParam::new(a), attrs_a),
+                        apply_attrs_to_abi_param(AbiParam::new(b), attrs_b),
                     ]
                 }
                 _ => unreachable!("{:?}", self.layout.backend_repr),
             },
             PassMode::Cast { ref cast, pad_i32 } => {
                 assert!(!pad_i32, "padding support not yet implemented");
-                cast_target_to_abi_params(cast)
+                cast_target_to_abi_params(cast).into_iter().map(|(_, param)| param).collect()
             }
             PassMode::Indirect { attrs, meta_attrs: None, on_stack } => {
                 if on_stack {
                     // Abi requires aligning struct size to pointer size
                     let size = self.layout.size.align_to(tcx.data_layout.pointer_align.abi);
                     let size = u32::try_from(size.bytes()).unwrap();
-                    smallvec![apply_arg_attrs_to_abi_param(
+                    smallvec![apply_attrs_to_abi_param(
                         AbiParam::special(pointer_ty(tcx), ArgumentPurpose::StructArgument(size),),
                         attrs
                     )]
                 } else {
-                    smallvec![apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs)]
+                    smallvec![apply_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs)]
                 }
             }
             PassMode::Indirect { attrs, meta_attrs: Some(meta_attrs), on_stack } => {
                 assert!(!on_stack);
                 smallvec![
-                    apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs),
-                    apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), meta_attrs),
+                    apply_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs),
+                    apply_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), meta_attrs),
                 ]
             }
         }
@@ -133,30 +150,47 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
     fn get_abi_return(&self, tcx: TyCtxt<'tcx>) -> (Option<AbiParam>, Vec<AbiParam>) {
         match self.mode {
             PassMode::Ignore => (None, vec![]),
-            PassMode::Direct(_) => match self.layout.backend_repr {
-                BackendRepr::Scalar(scalar) => {
-                    (None, vec![AbiParam::new(scalar_to_clif_type(tcx, scalar))])
-                }
+            PassMode::Direct(attrs) => match self.layout.backend_repr {
+                BackendRepr::Scalar(scalar) => (
+                    None,
+                    vec![apply_attrs_to_abi_param(
+                        AbiParam::new(scalar_to_clif_type(tcx, scalar)),
+                        attrs,
+                    )],
+                ),
                 BackendRepr::SimdVector { .. } => {
                     let vector_ty = crate::intrinsics::clif_vector_type(tcx, self.layout);
-                    (None, vec![AbiParam::new(vector_ty)])
+                    (None, vec![apply_attrs_to_abi_param(AbiParam::new(vector_ty), attrs)])
                 }
                 _ => unreachable!("{:?}", self.layout.backend_repr),
             },
-            PassMode::Pair(_, _) => match self.layout.backend_repr {
+            PassMode::Pair(attrs_a, attrs_b) => match self.layout.backend_repr {
                 BackendRepr::ScalarPair(a, b) => {
                     let a = scalar_to_clif_type(tcx, a);
                     let b = scalar_to_clif_type(tcx, b);
-                    (None, vec![AbiParam::new(a), AbiParam::new(b)])
+                    (
+                        None,
+                        vec![
+                            apply_attrs_to_abi_param(AbiParam::new(a), attrs_a),
+                            apply_attrs_to_abi_param(AbiParam::new(b), attrs_b),
+                        ],
+                    )
                 }
                 _ => unreachable!("{:?}", self.layout.backend_repr),
             },
-            PassMode::Cast { ref cast, .. } => {
-                (None, cast_target_to_abi_params(cast).into_iter().collect())
-            }
-            PassMode::Indirect { attrs: _, meta_attrs: None, on_stack } => {
+            PassMode::Cast { ref cast, .. } => (
+                None,
+                cast_target_to_abi_params(cast).into_iter().map(|(_, param)| param).collect(),
+            ),
+            PassMode::Indirect { attrs, meta_attrs: None, on_stack } => {
                 assert!(!on_stack);
-                (Some(AbiParam::special(pointer_ty(tcx), ArgumentPurpose::StructReturn)), vec![])
+                (
+                    Some(apply_attrs_to_abi_param(
+                        AbiParam::special(pointer_ty(tcx), ArgumentPurpose::StructReturn),
+                        attrs,
+                    )),
+                    vec![],
+                )
             }
             PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => {
                 unreachable!("unsized return value")
@@ -172,12 +206,14 @@ pub(super) fn to_casted_value<'tcx>(
 ) -> SmallVec<[Value; 2]> {
     let (ptr, meta) = arg.force_stack(fx);
     assert!(meta.is_none());
-    let mut offset = 0;
     cast_target_to_abi_params(cast)
         .into_iter()
-        .map(|param| {
-            let val = ptr.offset_i64(fx, offset).load(fx, param.value_type, MemFlags::new());
-            offset += i64::from(param.value_type.bytes());
+        .map(|(offset, param)| {
+            let val = ptr.offset_i64(fx, offset.bytes() as i64).load(
+                fx,
+                param.value_type,
+                MemFlags::new(),
+            );
             val
         })
         .collect()
@@ -190,7 +226,7 @@ pub(super) fn from_casted_value<'tcx>(
     cast: &CastTarget,
 ) -> CValue<'tcx> {
     let abi_params = cast_target_to_abi_params(cast);
-    let abi_param_size: u32 = abi_params.iter().map(|param| param.value_type.bytes()).sum();
+    let abi_param_size: u32 = abi_params.iter().map(|(_, param)| param.value_type.bytes()).sum();
     let layout_size = u32::try_from(layout.size.bytes()).unwrap();
     let ptr = fx.create_stack_slot(
         // Stack slot size may be bigger for example `[u8; 3]` which is packed into an `i32`.
@@ -199,16 +235,13 @@ pub(super) fn from_casted_value<'tcx>(
         std::cmp::max(abi_param_size, layout_size),
         u32::try_from(layout.align.abi.bytes()).unwrap(),
     );
-    let mut offset = 0;
     let mut block_params_iter = block_params.iter().copied();
-    for param in abi_params {
-        let val = ptr.offset_i64(fx, offset).store(
+    for (offset, _) in abi_params {
+        ptr.offset_i64(fx, offset.bytes() as i64).store(
             fx,
             block_params_iter.next().unwrap(),
             MemFlags::new(),
-        );
-        offset += i64::from(param.value_type.bytes());
-        val
+        )
     }
     assert_eq!(block_params_iter.next(), None, "Leftover block param");
     CValue::by_ref(ptr, layout)
diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
index 5d07c94859f..442151fe32d 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/aot.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
@@ -11,7 +11,6 @@ use std::thread::JoinHandle;
 use cranelift_object::{ObjectBuilder, ObjectModule};
 use rustc_codegen_ssa::assert_module_sources::CguReuse;
 use rustc_codegen_ssa::back::link::ensure_removed;
-use rustc_codegen_ssa::back::metadata::create_compressed_metadata_file;
 use rustc_codegen_ssa::base::determine_cgu_reuse;
 use rustc_codegen_ssa::{
     CodegenResults, CompiledModule, CrateInfo, ModuleKind, errors as ssa_errors,
@@ -19,7 +18,6 @@ use rustc_codegen_ssa::{
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{IntoDynSyncSend, par_map};
-use rustc_metadata::EncodedMetadata;
 use rustc_metadata::fs::copy_to_stdout;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
@@ -61,8 +59,6 @@ impl<HCX> HashStable<HCX> for OngoingModuleCodegen {
 pub(crate) struct OngoingCodegen {
     modules: Vec<OngoingModuleCodegen>,
     allocator_module: Option<CompiledModule>,
-    metadata_module: Option<CompiledModule>,
-    metadata: EncodedMetadata,
     crate_info: CrateInfo,
     concurrency_limiter: ConcurrencyLimiter,
 }
@@ -134,8 +130,6 @@ impl OngoingCodegen {
         let codegen_results = CodegenResults {
             modules,
             allocator_module: self.allocator_module,
-            metadata_module: self.metadata_module,
-            metadata: self.metadata,
             crate_info: self.crate_info,
         };
 
@@ -646,42 +640,6 @@ fn module_codegen(
     }))
 }
 
-fn emit_metadata_module(tcx: TyCtxt<'_>, metadata: &EncodedMetadata) -> CompiledModule {
-    use rustc_middle::mir::mono::CodegenUnitNameBuilder;
-
-    let _timer = tcx.sess.timer("write compressed metadata");
-
-    let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
-    let metadata_cgu_name = cgu_name_builder
-        .build_cgu_name(LOCAL_CRATE, ["crate"], Some("metadata"))
-        .as_str()
-        .to_string();
-
-    let tmp_file = tcx.output_filenames(()).temp_path_for_cgu(
-        OutputType::Metadata,
-        &metadata_cgu_name,
-        tcx.sess.invocation_temp.as_deref(),
-    );
-
-    let symbol_name = rustc_middle::middle::exported_symbols::metadata_symbol_name(tcx);
-    let obj = create_compressed_metadata_file(tcx.sess, metadata, &symbol_name);
-
-    if let Err(err) = std::fs::write(&tmp_file, obj) {
-        tcx.dcx().fatal(format!("error writing metadata object file: {}", err));
-    }
-
-    CompiledModule {
-        name: metadata_cgu_name,
-        kind: ModuleKind::Metadata,
-        object: Some(tmp_file),
-        dwarf_object: None,
-        bytecode: None,
-        assembly: None,
-        llvm_ir: None,
-        links_from_incr_cache: Vec::new(),
-    }
-}
-
 fn emit_allocator_module(tcx: TyCtxt<'_>) -> Option<CompiledModule> {
     let mut allocator_module = make_module(tcx.sess, "allocator_shim".to_string());
     let created_alloc_shim = crate::allocator::codegen(tcx, &mut allocator_module);
@@ -706,11 +664,7 @@ fn emit_allocator_module(tcx: TyCtxt<'_>) -> Option<CompiledModule> {
     }
 }
 
-pub(crate) fn run_aot(
-    tcx: TyCtxt<'_>,
-    metadata: EncodedMetadata,
-    need_metadata_module: bool,
-) -> Box<OngoingCodegen> {
+pub(crate) fn run_aot(tcx: TyCtxt<'_>) -> Box<OngoingCodegen> {
     // FIXME handle `-Ctarget-cpu=native`
     let target_cpu = match tcx.sess.opts.cg.target_cpu {
         Some(ref name) => name,
@@ -726,8 +680,6 @@ pub(crate) fn run_aot(
         return Box::new(OngoingCodegen {
             modules: vec![],
             allocator_module: None,
-            metadata_module: None,
-            metadata,
             crate_info: CrateInfo::new(tcx, target_cpu),
             concurrency_limiter: ConcurrencyLimiter::new(0),
         });
@@ -787,14 +739,9 @@ pub(crate) fn run_aot(
 
     let allocator_module = emit_allocator_module(tcx);
 
-    let metadata_module =
-        if need_metadata_module { Some(emit_metadata_module(tcx, &metadata)) } else { None };
-
     Box::new(OngoingCodegen {
         modules,
         allocator_module,
-        metadata_module,
-        metadata,
         crate_info: CrateInfo::new(tcx, target_cpu),
         concurrency_limiter: concurrency_limiter.0,
     })
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index 8ef623cde00..07ea29f3024 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -46,7 +46,6 @@ use cranelift_codegen::isa::TargetIsa;
 use cranelift_codegen::settings::{self, Configurable};
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_codegen_ssa::{CodegenResults, TargetConfig};
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_session::Session;
 use rustc_session::config::OutputFilenames;
@@ -238,12 +237,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
         println!("Cranelift version: {}", cranelift_codegen::VERSION);
     }
 
-    fn codegen_crate(
-        &self,
-        tcx: TyCtxt<'_>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
         info!("codegen crate {}", tcx.crate_name(LOCAL_CRATE));
         let config = self.config.clone().unwrap_or_else(|| {
             BackendConfig::from_opts(&tcx.sess.opts.cg.llvm_args)
@@ -256,7 +250,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
             #[cfg(not(feature = "jit"))]
             tcx.dcx().fatal("jit support was disabled when compiling rustc_codegen_cranelift");
         } else {
-            driver::aot::run_aot(tcx, metadata, need_metadata_module)
+            driver::aot::run_aot(tcx)
         }
     }
 
diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs
index 1bd89212100..68c6156fa4b 100644
--- a/compiler/rustc_codegen_gcc/src/builder.rs
+++ b/compiler/rustc_codegen_gcc/src/builder.rs
@@ -30,7 +30,7 @@ use rustc_middle::ty::{self, AtomicOrdering, Instance, Ty, TyCtxt};
 use rustc_span::Span;
 use rustc_span::def_id::DefId;
 use rustc_target::callconv::FnAbi;
-use rustc_target::spec::{HasTargetSpec, HasWasmCAbiOpt, HasX86AbiOpt, Target, WasmCAbi, X86Abi};
+use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, Target, X86Abi};
 
 use crate::common::{SignType, TypeReflection, type_is_pointer};
 use crate::context::CodegenCx;
@@ -2394,12 +2394,6 @@ impl<'tcx> HasTargetSpec for Builder<'_, '_, 'tcx> {
     }
 }
 
-impl<'tcx> HasWasmCAbiOpt for Builder<'_, '_, 'tcx> {
-    fn wasm_c_abi_opt(&self) -> WasmCAbi {
-        self.cx.wasm_c_abi_opt()
-    }
-}
-
 impl<'tcx> HasX86AbiOpt for Builder<'_, '_, 'tcx> {
     fn x86_abi_opt(&self) -> X86Abi {
         self.cx.x86_abi_opt()
diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
index c6c43201f21..4955e039e7b 100644
--- a/compiler/rustc_codegen_gcc/src/context.rs
+++ b/compiler/rustc_codegen_gcc/src/context.rs
@@ -19,9 +19,7 @@ use rustc_middle::ty::{self, ExistentialTraitRef, Instance, Ty, TyCtxt};
 use rustc_session::Session;
 use rustc_span::source_map::respan;
 use rustc_span::{DUMMY_SP, Span};
-use rustc_target::spec::{
-    HasTargetSpec, HasWasmCAbiOpt, HasX86AbiOpt, Target, TlsModel, WasmCAbi, X86Abi,
-};
+use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, Target, TlsModel, X86Abi};
 
 #[cfg(feature = "master")]
 use crate::abi::conv_to_fn_attribute;
@@ -512,12 +510,6 @@ impl<'gcc, 'tcx> HasTargetSpec for CodegenCx<'gcc, 'tcx> {
     }
 }
 
-impl<'gcc, 'tcx> HasWasmCAbiOpt for CodegenCx<'gcc, 'tcx> {
-    fn wasm_c_abi_opt(&self) -> WasmCAbi {
-        self.tcx.sess.opts.unstable_opts.wasm_c_abi
-    }
-}
-
 impl<'gcc, 'tcx> HasX86AbiOpt for CodegenCx<'gcc, 'tcx> {
     fn x86_abi_opt(&self) -> X86Abi {
         X86Abi {
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
index 9e05b8f23aa..c921851b42b 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -626,7 +626,7 @@ impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                 bx.lifetime_start(llscratch, scratch_size);
 
                 // ... where we first store the value...
-                bx.store(val, llscratch, scratch_align);
+                rustc_codegen_ssa::mir::store_cast(bx, cast, val, llscratch, scratch_align);
 
                 // ... and then memcpy it to the intended destination.
                 bx.memcpy(
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index 0591ffa42e4..dbecbc42618 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -48,7 +48,6 @@ extern crate rustc_index;
 #[cfg(feature = "master")]
 extern crate rustc_interface;
 extern crate rustc_macros;
-extern crate rustc_metadata;
 extern crate rustc_middle;
 extern crate rustc_session;
 extern crate rustc_span;
@@ -106,7 +105,6 @@ use rustc_codegen_ssa::{CodegenResults, CompiledModule, ModuleCodegen, TargetCon
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::IntoDynSyncSend;
 use rustc_errors::DiagCtxtHandle;
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::util::Providers;
@@ -230,20 +228,9 @@ impl CodegenBackend for GccCodegenBackend {
         providers.global_backend_features = |tcx, ()| gcc_util::global_gcc_features(tcx.sess, true)
     }
 
-    fn codegen_crate(
-        &self,
-        tcx: TyCtxt<'_>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
         let target_cpu = target_cpu(tcx.sess);
-        let res = codegen_crate(
-            self.clone(),
-            tcx,
-            target_cpu.to_string(),
-            metadata,
-            need_metadata_module,
-        );
+        let res = codegen_crate(self.clone(), tcx, target_cpu.to_string());
 
         Box::new(res)
     }
diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs
index aba63d75f1d..4b07c8aef91 100644
--- a/compiler/rustc_codegen_llvm/src/abi.rs
+++ b/compiler/rustc_codegen_llvm/src/abi.rs
@@ -229,7 +229,7 @@ impl<'ll, 'tcx> ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                 let llscratch = bx.alloca(scratch_size, scratch_align);
                 bx.lifetime_start(llscratch, scratch_size);
                 // ...store the value...
-                bx.store(val, llscratch, scratch_align);
+                rustc_codegen_ssa::mir::store_cast(bx, cast, val, llscratch, scratch_align);
                 // ... and then memcpy it to the intended destination.
                 bx.memcpy(
                     dst.val.llval,
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index 4185aef8b31..9ddadcf16aa 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -1021,6 +1021,15 @@ fn llvm_fixup_input<'ll, 'tcx>(
         ) if element.primitive() == Primitive::Float(Float::F16) => {
             bx.bitcast(value, bx.type_vector(bx.type_i16(), count))
         }
+        (LoongArch(LoongArchInlineAsmRegClass::freg), BackendRepr::Scalar(s))
+            if s.primitive() == Primitive::Float(Float::F16) =>
+        {
+            // Smaller floats are always "NaN-boxed" inside larger floats on LoongArch.
+            let value = bx.bitcast(value, bx.type_i16());
+            let value = bx.zext(value, bx.type_i32());
+            let value = bx.or(value, bx.const_u32(0xFFFF_0000));
+            bx.bitcast(value, bx.type_f32())
+        }
         (Mips(MipsInlineAsmRegClass::reg), BackendRepr::Scalar(s)) => {
             match s.primitive() {
                 // MIPS only supports register-length arithmetics.
@@ -1178,6 +1187,13 @@ fn llvm_fixup_output<'ll, 'tcx>(
         ) if element.primitive() == Primitive::Float(Float::F16) => {
             bx.bitcast(value, bx.type_vector(bx.type_f16(), count))
         }
+        (LoongArch(LoongArchInlineAsmRegClass::freg), BackendRepr::Scalar(s))
+            if s.primitive() == Primitive::Float(Float::F16) =>
+        {
+            let value = bx.bitcast(value, bx.type_i32());
+            let value = bx.trunc(value, bx.type_i16());
+            bx.bitcast(value, bx.type_f16())
+        }
         (Mips(MipsInlineAsmRegClass::reg), BackendRepr::Scalar(s)) => {
             match s.primitive() {
                 // MIPS only supports register-length arithmetics.
@@ -1318,6 +1334,11 @@ fn llvm_fixup_output_type<'ll, 'tcx>(
         ) if element.primitive() == Primitive::Float(Float::F16) => {
             cx.type_vector(cx.type_i16(), count)
         }
+        (LoongArch(LoongArchInlineAsmRegClass::freg), BackendRepr::Scalar(s))
+            if s.primitive() == Primitive::Float(Float::F16) =>
+        {
+            cx.type_f32()
+        }
         (Mips(MipsInlineAsmRegClass::reg), BackendRepr::Scalar(s)) => {
             match s.primitive() {
                 // MIPS only supports register-length arithmetics.
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 09cb74d9dcb..5e9594dd06b 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -507,7 +507,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
 
         let name = format!("llvm.{}{oop_str}.with.overflow", if signed { 's' } else { 'u' });
 
-        let res = self.call_intrinsic(&name, &[self.type_ix(width)], &[lhs, rhs]);
+        let res = self.call_intrinsic(name, &[self.type_ix(width)], &[lhs, rhs]);
         (self.extract_value(res, 0), self.extract_value(res, 1))
     }
 
@@ -1038,7 +1038,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         let size = ty.primitive_size(self.tcx);
         let name = if ty.is_signed() { "llvm.scmp" } else { "llvm.ucmp" };
 
-        Some(self.call_intrinsic(&name, &[self.type_i8(), self.type_ix(size.bits())], &[lhs, rhs]))
+        Some(self.call_intrinsic(name, &[self.type_i8(), self.type_ix(size.bits())], &[lhs, rhs]))
     }
 
     /* Miscellaneous instructions */
@@ -1393,7 +1393,8 @@ impl<'ll> StaticBuilderMethods for Builder<'_, 'll, '_> {
         // Forward to the `get_static` method of `CodegenCx`
         let global = self.cx().get_static(def_id);
         if self.cx().tcx.is_thread_local_static(def_id) {
-            let pointer = self.call_intrinsic("llvm.threadlocal.address", &[], &[global]);
+            let pointer =
+                self.call_intrinsic("llvm.threadlocal.address", &[self.val_ty(global)], &[global]);
             // Cast to default address space if globals are in a different addrspace
             self.pointercast(pointer, self.type_ptr())
         } else {
@@ -1590,15 +1591,15 @@ impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
 impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
     pub(crate) fn call_intrinsic(
         &mut self,
-        base_name: &str,
+        base_name: impl Into<Cow<'static, str>>,
         type_params: &[&'ll Type],
         args: &[&'ll Value],
     ) -> &'ll Value {
-        let (ty, f) = self.cx.get_intrinsic(base_name, type_params);
+        let (ty, f) = self.cx.get_intrinsic(base_name.into(), type_params);
         self.call(ty, None, None, f, args, None, None)
     }
 
-    fn call_lifetime_intrinsic(&mut self, intrinsic: &str, ptr: &'ll Value, size: Size) {
+    fn call_lifetime_intrinsic(&mut self, intrinsic: &'static str, ptr: &'ll Value, size: Size) {
         let size = size.bytes();
         if size == 0 {
             return;
@@ -1608,7 +1609,7 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
             return;
         }
 
-        self.call_intrinsic(intrinsic, &[self.type_ptr()], &[self.cx.const_u64(size), ptr]);
+        self.call_intrinsic(intrinsic, &[self.val_ty(ptr)], &[self.cx.const_u64(size), ptr]);
     }
 }
 impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index f36f3b2b16b..bff95ea46fa 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -1,4 +1,4 @@
-use std::borrow::Borrow;
+use std::borrow::{Borrow, Cow};
 use std::cell::{Cell, RefCell};
 use std::ffi::{CStr, c_char, c_uint};
 use std::marker::PhantomData;
@@ -138,7 +138,7 @@ pub(crate) struct FullCx<'ll, 'tcx> {
     pub rust_try_fn: Cell<Option<(&'ll Type, &'ll Value)>>,
 
     intrinsics:
-        RefCell<FxHashMap<(&'static str, SmallVec<[&'ll Type; 2]>), (&'ll Type, &'ll Value)>>,
+        RefCell<FxHashMap<(Cow<'static, str>, SmallVec<[&'ll Type; 2]>), (&'ll Type, &'ll Value)>>,
 
     /// A counter that is used for generating local symbol names
     local_gen_sym_counter: Cell<usize>,
@@ -845,45 +845,16 @@ impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 impl<'ll> CodegenCx<'ll, '_> {
     pub(crate) fn get_intrinsic(
         &self,
-        base_name: &str,
+        base_name: Cow<'static, str>,
         type_params: &[&'ll Type],
     ) -> (&'ll Type, &'ll Value) {
-        if let Some(v) =
-            self.intrinsics.borrow().get(&(base_name, SmallVec::from_slice(type_params)))
-        {
-            return *v;
-        }
-
-        self.declare_intrinsic(base_name, type_params)
-    }
-
-    fn insert_intrinsic(
-        &self,
-        base_name: &'static str,
-        type_params: &[&'ll Type],
-        args: Option<&[&'ll llvm::Type]>,
-        ret: &'ll llvm::Type,
-    ) -> (&'ll llvm::Type, &'ll llvm::Value) {
-        let fn_ty = if let Some(args) = args {
-            self.type_func(args, ret)
-        } else {
-            self.type_variadic_func(&[], ret)
-        };
-
-        let intrinsic = llvm::Intrinsic::lookup(base_name.as_bytes())
-            .expect("Unknown LLVM intrinsic `{base_name}`");
-
-        let full_name = if intrinsic.is_overloaded() {
-            &intrinsic.overloaded_name(self.llmod, type_params)
-        } else {
-            base_name
-        };
-
-        let f = self.declare_cfn(full_name, llvm::UnnamedAddr::No, fn_ty);
-        self.intrinsics
+        *self
+            .intrinsics
             .borrow_mut()
-            .insert((base_name, SmallVec::from_slice(type_params)), (fn_ty, f));
-        (fn_ty, f)
+            .entry((base_name, SmallVec::from_slice(type_params)))
+            .or_insert_with_key(|(base_name, type_params)| {
+                self.declare_intrinsic(base_name, type_params)
+            })
     }
 
     fn declare_intrinsic(
@@ -891,155 +862,22 @@ impl<'ll> CodegenCx<'ll, '_> {
         base_name: &str,
         type_params: &[&'ll Type],
     ) -> (&'ll Type, &'ll Value) {
-        macro_rules! param {
-            ($index:literal) => {
-                type_params[$index]
-            };
-            ($other:expr) => {
-                $other
-            };
-        }
-        macro_rules! ifn {
-            ($name:expr, fn(...) -> $ret:expr) => (
-                if base_name == $name {
-                    return self.insert_intrinsic($name, type_params, None, param!($ret));
-                }
-            );
-            ($name:expr, fn($($arg:expr),*) -> $ret:expr) => (
-                if base_name == $name {
-                    return self.insert_intrinsic($name, type_params, Some(&[$(param!($arg)),*]), param!($ret));
-                }
-            );
-        }
-        macro_rules! mk_struct {
-            ($($field_ty:expr),*) => (self.type_struct( &[$(param!($field_ty)),*], false))
-        }
-
-        let same_width_vector = |index, element_ty| {
-            self.type_vector(element_ty, self.vector_length(type_params[index]) as u64)
-        };
-
-        let ptr = self.type_ptr();
-        let void = self.type_void();
-        let i1 = self.type_i1();
-        let t_i32 = self.type_i32();
-        let t_i64 = self.type_i64();
-        let t_isize = self.type_isize();
-        let t_metadata = self.type_metadata();
-        let t_token = self.type_token();
-
-        ifn!("llvm.wasm.get.exception", fn(t_token) -> ptr);
-        ifn!("llvm.wasm.get.ehselector", fn(t_token) -> t_i32);
-
-        ifn!("llvm.wasm.trunc.unsigned", fn(1) -> 0);
-        ifn!("llvm.wasm.trunc.signed", fn(1) -> 0);
-        ifn!("llvm.fptosi.sat", fn(1) -> 0);
-        ifn!("llvm.fptoui.sat", fn(1) -> 0);
-
-        ifn!("llvm.trap", fn() -> void);
-        ifn!("llvm.debugtrap", fn() -> void);
-        ifn!("llvm.frameaddress", fn(t_i32) -> ptr);
-
-        ifn!("llvm.powi", fn(0, 1) -> 0);
-        ifn!("llvm.pow", fn(0, 0) -> 0);
-        ifn!("llvm.sqrt", fn(0) -> 0);
-        ifn!("llvm.sin", fn(0) -> 0);
-        ifn!("llvm.cos", fn(0) -> 0);
-        ifn!("llvm.exp", fn(0) -> 0);
-        ifn!("llvm.exp2", fn(0) -> 0);
-        ifn!("llvm.log", fn(0) -> 0);
-        ifn!("llvm.log10", fn(0) -> 0);
-        ifn!("llvm.log2", fn(0) -> 0);
-        ifn!("llvm.fma", fn(0, 0, 0) -> 0);
-        ifn!("llvm.fmuladd", fn(0, 0, 0) -> 0);
-        ifn!("llvm.fabs", fn(0) -> 0);
-        ifn!("llvm.minnum", fn(0, 0) -> 0);
-        ifn!("llvm.minimum", fn(0, 0) -> 0);
-        ifn!("llvm.maxnum", fn(0, 0) -> 0);
-        ifn!("llvm.maximum", fn(0, 0) -> 0);
-        ifn!("llvm.floor", fn(0) -> 0);
-        ifn!("llvm.ceil", fn(0) -> 0);
-        ifn!("llvm.trunc", fn(0) -> 0);
-        ifn!("llvm.copysign", fn(0, 0) -> 0);
-        ifn!("llvm.round", fn(0) -> 0);
-        ifn!("llvm.rint", fn(0) -> 0);
-        ifn!("llvm.nearbyint", fn(0) -> 0);
-
-        ifn!("llvm.ctpop", fn(0) -> 0);
-        ifn!("llvm.ctlz", fn(0, i1) -> 0);
-        ifn!("llvm.cttz", fn(0, i1) -> 0);
-        ifn!("llvm.bswap", fn(0) -> 0);
-        ifn!("llvm.bitreverse", fn(0) -> 0);
-        ifn!("llvm.fshl", fn(0, 0, 0) -> 0);
-        ifn!("llvm.fshr", fn(0, 0, 0) -> 0);
-
-        ifn!("llvm.sadd.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-        ifn!("llvm.uadd.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-        ifn!("llvm.ssub.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-        ifn!("llvm.usub.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-        ifn!("llvm.smul.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-        ifn!("llvm.umul.with.overflow", fn(0, 0) -> mk_struct! {0, i1});
-
-        ifn!("llvm.sadd.sat", fn(0, 0) -> 0);
-        ifn!("llvm.uadd.sat", fn(0, 0) -> 0);
-        ifn!("llvm.ssub.sat", fn(0, 0) -> 0);
-        ifn!("llvm.usub.sat", fn(0, 0) -> 0);
-
-        ifn!("llvm.scmp", fn(1, 1) -> 0);
-        ifn!("llvm.ucmp", fn(1, 1) -> 0);
-
-        ifn!("llvm.lifetime.start", fn(t_i64, 0) -> void);
-        ifn!("llvm.lifetime.end", fn(t_i64, 0) -> void);
-
-        ifn!("llvm.is.constant", fn(0) -> i1);
-        ifn!("llvm.expect", fn(0, 0) -> 0);
-
-        ifn!("llvm.eh.typeid.for", fn(0) -> t_i32);
-        ifn!("llvm.localescape", fn(...) -> void);
-        ifn!("llvm.localrecover", fn(ptr, ptr, t_i32) -> ptr);
-
-        ifn!("llvm.assume", fn(i1) -> void);
-        ifn!("llvm.prefetch", fn(0, t_i32, t_i32, t_i32) -> void);
-
         // This isn't an "LLVM intrinsic", but LLVM's optimization passes
         // recognize it like one (including turning it into `bcmp` sometimes)
         // and we use it to implement intrinsics like `raw_eq` and `compare_bytes`
         if base_name == "memcmp" {
-            let fn_ty = self.type_func(&[ptr, ptr, t_isize], self.type_int());
+            let fn_ty = self
+                .type_func(&[self.type_ptr(), self.type_ptr(), self.type_isize()], self.type_int());
             let f = self.declare_cfn("memcmp", llvm::UnnamedAddr::No, fn_ty);
-            self.intrinsics.borrow_mut().insert(("memcmp", SmallVec::new()), (fn_ty, f));
 
             return (fn_ty, f);
         }
 
-        // variadic intrinsics
-        ifn!("llvm.va_start", fn(0) -> void);
-        ifn!("llvm.va_end", fn(0) -> void);
-        ifn!("llvm.va_copy", fn(0, 0) -> void);
-
-        if self.sess().instrument_coverage() {
-            ifn!("llvm.instrprof.increment", fn(ptr, t_i64, t_i32, t_i32) -> void);
-            ifn!("llvm.instrprof.mcdc.parameters", fn(ptr, t_i64, t_i32) -> void);
-            ifn!("llvm.instrprof.mcdc.tvbitmap.update", fn(ptr, t_i64, t_i32, ptr) -> void);
-        }
-
-        ifn!("llvm.type.test", fn(ptr, t_metadata) -> i1);
-        ifn!("llvm.type.checked.load", fn(ptr, t_i32, t_metadata) -> mk_struct! {ptr, i1});
-
-        if self.sess().opts.debuginfo != DebugInfo::None {
-            ifn!("llvm.dbg.declare", fn(t_metadata, t_metadata, t_metadata) -> void);
-            ifn!("llvm.dbg.value", fn(t_metadata, t_metadata, t_metadata) -> void);
-        }
-
-        ifn!("llvm.ptrmask", fn(0, 1) -> 0);
-        ifn!("llvm.threadlocal.address", fn(ptr) -> ptr);
-
-        ifn!("llvm.masked.load", fn(1, t_i32, same_width_vector(0, i1), 0) -> 0);
-        ifn!("llvm.masked.store", fn(0, 1, t_i32, same_width_vector(0, i1)) -> void);
-        ifn!("llvm.masked.gather", fn(1, t_i32, same_width_vector(0, i1), 0) -> 0);
-        ifn!("llvm.masked.scatter", fn(0, 1, t_i32, same_width_vector(0, i1)) -> void);
+        let intrinsic = llvm::Intrinsic::lookup(base_name.as_bytes())
+            .unwrap_or_else(|| bug!("Unknown intrinsic: `{base_name}`"));
+        let f = intrinsic.get_declaration(self.llmod, &type_params);
 
-        bug!("Unknown intrinsic: `{base_name}`")
+        (self.get_type_of_global(f), f)
     }
 
     pub(crate) fn eh_catch_typeinfo(&self) -> &'ll Value {
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index 497c31706ec..f7f062849a8 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -154,8 +154,6 @@ fn call_simple_intrinsic<'ll, 'tcx>(
         sym::roundf64 => ("llvm.round", &[bx.type_f64()]),
         sym::roundf128 => ("llvm.round", &[bx.type_f128()]),
 
-        sym::ptr_mask => ("llvm.ptrmask", &[bx.type_ptr(), bx.type_isize()]),
-
         _ => return None,
     };
     Some(bx.call_intrinsic(
@@ -181,6 +179,14 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
         let simple = call_simple_intrinsic(self, name, args);
         let llval = match name {
             _ if simple.is_some() => simple.unwrap(),
+            sym::ptr_mask => {
+                let ptr = args[0].immediate();
+                self.call_intrinsic(
+                    "llvm.ptrmask",
+                    &[self.val_ty(ptr), self.type_isize()],
+                    &[ptr, args[1].immediate()],
+                )
+            }
             sym::is_val_statically_known => {
                 if let OperandValue::Immediate(imm) = args[0].val {
                     self.call_intrinsic(
@@ -232,11 +238,14 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                 return Ok(());
             }
             sym::breakpoint => self.call_intrinsic("llvm.debugtrap", &[], &[]),
-            sym::va_copy => self.call_intrinsic(
-                "llvm.va_copy",
-                &[self.type_ptr()],
-                &[args[0].immediate(), args[1].immediate()],
-            ),
+            sym::va_copy => {
+                let dest = args[0].immediate();
+                self.call_intrinsic(
+                    "llvm.va_copy",
+                    &[self.val_ty(dest)],
+                    &[dest, args[1].immediate()],
+                )
+            }
             sym::va_arg => {
                 match result.layout.backend_repr {
                     BackendRepr::Scalar(scalar) => {
@@ -309,15 +318,11 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                     sym::prefetch_write_instruction => (1, 0),
                     _ => bug!(),
                 };
+                let ptr = args[0].immediate();
                 self.call_intrinsic(
                     "llvm.prefetch",
-                    &[self.type_ptr()],
-                    &[
-                        args[0].immediate(),
-                        self.const_i32(rw),
-                        args[1].immediate(),
-                        self.const_i32(cache_type),
-                    ],
+                    &[self.val_ty(ptr)],
+                    &[ptr, self.const_i32(rw), args[1].immediate(), self.const_i32(cache_type)],
                 )
             }
             sym::carrying_mul_add => {
@@ -378,7 +383,7 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                     sym::ctlz | sym::cttz => {
                         let y = self.const_bool(false);
                         let ret = self.call_intrinsic(
-                            &format!("llvm.{name}"),
+                            format!("llvm.{name}"),
                             &[llty],
                             &[args[0].immediate(), y],
                         );
@@ -423,7 +428,7 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                         // always uses `u32`.
                         let raw_shift = self.intcast(raw_shift, self.val_ty(val), false);
 
-                        self.call_intrinsic(&llvm_name, &[llty], &[val, val, raw_shift])
+                        self.call_intrinsic(llvm_name, &[llty], &[val, val, raw_shift])
                     }
                     sym::saturating_add | sym::saturating_sub => {
                         let is_add = name == sym::saturating_add;
@@ -434,7 +439,7 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                             if signed { 's' } else { 'u' },
                             if is_add { "add" } else { "sub" },
                         );
-                        self.call_intrinsic(&llvm_name, &[llty], &[lhs, rhs])
+                        self.call_intrinsic(llvm_name, &[llty], &[lhs, rhs])
                     }
                     _ => bug!(),
                 }
@@ -637,11 +642,11 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
     }
 
     fn va_start(&mut self, va_list: &'ll Value) -> &'ll Value {
-        self.call_intrinsic("llvm.va_start", &[self.type_ptr()], &[va_list])
+        self.call_intrinsic("llvm.va_start", &[self.val_ty(va_list)], &[va_list])
     }
 
     fn va_end(&mut self, va_list: &'ll Value) -> &'ll Value {
-        self.call_intrinsic("llvm.va_end", &[self.type_ptr()], &[va_list])
+        self.call_intrinsic("llvm.va_end", &[self.val_ty(va_list)], &[va_list])
     }
 }
 
@@ -1018,7 +1023,7 @@ fn codegen_emcc_try<'ll, 'tcx>(
         let selector = bx.extract_value(vals, 1);
 
         // Check if the typeid we got is the one for a Rust panic.
-        let rust_typeid = bx.call_intrinsic("llvm.eh.typeid.for", &[bx.type_ptr()], &[tydesc]);
+        let rust_typeid = bx.call_intrinsic("llvm.eh.typeid.for", &[bx.val_ty(tydesc)], &[tydesc]);
         let is_rust_panic = bx.icmp(IntPredicate::IntEQ, selector, rust_typeid);
         let is_rust_panic = bx.zext(is_rust_panic, bx.type_bool());
 
@@ -2393,7 +2398,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
         );
         let vec_ty = bx.cx.type_vector(elem_ty, in_len as u64);
 
-        return Ok(bx.call_intrinsic(&llvm_intrinsic, &[vec_ty], &[lhs, rhs]));
+        return Ok(bx.call_intrinsic(llvm_intrinsic, &[vec_ty], &[lhs, rhs]));
     }
 
     span_bug!(span, "unknown SIMD intrinsic");
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 6890923a594..cdfffbe47bf 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -340,18 +340,11 @@ impl CodegenBackend for LlvmCodegenBackend {
         target_config(sess)
     }
 
-    fn codegen_crate<'tcx>(
-        &self,
-        tcx: TyCtxt<'tcx>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Box<dyn Any> {
         Box::new(rustc_codegen_ssa::base::codegen_crate(
             LlvmCodegenBackend(()),
             tcx,
             crate::llvm_util::target_cpu(tcx.sess).to_string(),
-            metadata,
-            need_metadata_module,
         ))
     }
 
@@ -376,14 +369,20 @@ impl CodegenBackend for LlvmCodegenBackend {
         (codegen_results, work_products)
     }
 
-    fn link(&self, sess: &Session, codegen_results: CodegenResults, outputs: &OutputFilenames) {
+    fn link(
+        &self,
+        sess: &Session,
+        codegen_results: CodegenResults,
+        metadata: EncodedMetadata,
+        outputs: &OutputFilenames,
+    ) {
         use rustc_codegen_ssa::back::link::link_binary;
 
         use crate::back::archive::LlvmArchiveBuilderBuilder;
 
         // Run the linker on any artifacts that resulted from the LLVM run.
         // This should produce either a finished executable or library.
-        link_binary(sess, &LlvmArchiveBuilderBuilder, codegen_results, outputs);
+        link_binary(sess, &LlvmArchiveBuilderBuilder, codegen_results, metadata, outputs);
     }
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 59c61db5fcd..91ada856d59 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1078,8 +1078,6 @@ unsafe extern "C" {
 
     // Operations on other types
     pub(crate) fn LLVMVoidTypeInContext(C: &Context) -> &Type;
-    pub(crate) fn LLVMTokenTypeInContext(C: &Context) -> &Type;
-    pub(crate) fn LLVMMetadataTypeInContext(C: &Context) -> &Type;
 
     // Operations on all values
     pub(crate) fn LLVMTypeOf(Val: &Value) -> &Type;
@@ -1198,14 +1196,12 @@ unsafe extern "C" {
 
     // Operations about llvm intrinsics
     pub(crate) fn LLVMLookupIntrinsicID(Name: *const c_char, NameLen: size_t) -> c_uint;
-    pub(crate) fn LLVMIntrinsicIsOverloaded(ID: NonZero<c_uint>) -> Bool;
-    pub(crate) fn LLVMIntrinsicCopyOverloadedName2<'a>(
+    pub(crate) fn LLVMGetIntrinsicDeclaration<'a>(
         Mod: &'a Module,
         ID: NonZero<c_uint>,
         ParamTypes: *const &'a Type,
         ParamCount: size_t,
-        NameLength: *mut size_t,
-    ) -> *mut c_char;
+    ) -> &'a Value;
 
     // Operations on parameters
     pub(crate) fn LLVMIsAArgument(Val: &Value) -> Option<&Value>;
diff --git a/compiler/rustc_codegen_llvm/src/llvm/mod.rs b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
index bc3538c768d..661174a80df 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
@@ -2,9 +2,9 @@
 
 use std::ffi::{CStr, CString};
 use std::num::NonZero;
+use std::ptr;
 use std::str::FromStr;
 use std::string::FromUtf8Error;
-use std::{ptr, slice};
 
 use libc::c_uint;
 use rustc_abi::{Align, Size, WrappingRange};
@@ -339,34 +339,14 @@ impl Intrinsic {
         NonZero::new(id).map(|id| Self { id })
     }
 
-    pub(crate) fn is_overloaded(self) -> bool {
-        unsafe { LLVMIntrinsicIsOverloaded(self.id) == True }
-    }
-
-    pub(crate) fn overloaded_name<'ll>(
+    pub(crate) fn get_declaration<'ll>(
         self,
         llmod: &'ll Module,
         type_params: &[&'ll Type],
-    ) -> String {
-        let mut len = 0;
-        let ptr = unsafe {
-            LLVMIntrinsicCopyOverloadedName2(
-                llmod,
-                self.id,
-                type_params.as_ptr(),
-                type_params.len(),
-                &mut len,
-            )
-        };
-
-        let slice = unsafe { slice::from_raw_parts_mut(ptr.cast(), len) };
-        let copied = str::from_utf8(slice).expect("Non-UTF8 intrinsic name").to_string();
-
+    ) -> &'ll Value {
         unsafe {
-            libc::free(ptr.cast());
+            LLVMGetIntrinsicDeclaration(llmod, self.id, type_params.as_ptr(), type_params.len())
         }
-
-        copied
     }
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs
index 2364ad0c9d2..453eca2bbe1 100644
--- a/compiler/rustc_codegen_llvm/src/type_.rs
+++ b/compiler/rustc_codegen_llvm/src/type_.rs
@@ -58,13 +58,6 @@ impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
     pub(crate) fn type_void(&self) -> &'ll Type {
         unsafe { llvm::LLVMVoidTypeInContext(self.llcx()) }
     }
-    pub(crate) fn type_token(&self) -> &'ll Type {
-        unsafe { llvm::LLVMTokenTypeInContext(self.llcx()) }
-    }
-
-    pub(crate) fn type_metadata(&self) -> &'ll Type {
-        unsafe { llvm::LLVMMetadataTypeInContext(self.llcx()) }
-    }
 
     ///x Creates an integer type with the given number of bits, e.g., i24
     pub(crate) fn type_ix(&self, num_bits: u64) -> &'ll Type {
diff --git a/compiler/rustc_codegen_ssa/messages.ftl b/compiler/rustc_codegen_ssa/messages.ftl
index 91f6af7fb93..5322fe58cf3 100644
--- a/compiler/rustc_codegen_ssa/messages.ftl
+++ b/compiler/rustc_codegen_ssa/messages.ftl
@@ -198,8 +198,6 @@ codegen_ssa_linking_failed = linking with `{$linker_path}` failed: {$exit_status
 codegen_ssa_malformed_cgu_name =
     found malformed codegen unit name `{$user_path}`. codegen units names must always start with the name of the crate (`{$crate_name}` in this case).
 
-codegen_ssa_metadata_object_file_write = error writing metadata object file: {$error}
-
 codegen_ssa_missing_cpp_build_tool_component = or a necessary component may be missing from the "C++ build tools" workload
 
 codegen_ssa_missing_features = add the missing features in a `target_feature` attribute
diff --git a/compiler/rustc_codegen_ssa/src/back/archive.rs b/compiler/rustc_codegen_ssa/src/back/archive.rs
index 1e1bdfb5977..84a56f6b0b5 100644
--- a/compiler/rustc_codegen_ssa/src/back/archive.rs
+++ b/compiler/rustc_codegen_ssa/src/back/archive.rs
@@ -14,11 +14,12 @@ use object::read::macho::FatArch;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::memmap::Mmap;
 use rustc_fs_util::TempDirBuilder;
+use rustc_metadata::EncodedMetadata;
 use rustc_session::Session;
 use rustc_span::Symbol;
 use tracing::trace;
 
-use super::metadata::search_for_section;
+use super::metadata::{create_compressed_metadata_file, search_for_section};
 use crate::common;
 // Re-exporting for rustc_codegen_llvm::back::archive
 pub use crate::errors::{ArchiveBuildFailure, ExtractBundledLibsError, UnknownArchiveKind};
@@ -58,6 +59,15 @@ impl From<ImportLibraryItem> for COFFShortExport {
 pub trait ArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a>;
 
+    fn create_dylib_metadata_wrapper(
+        &self,
+        sess: &Session,
+        metadata: &EncodedMetadata,
+        symbol_name: &str,
+    ) -> Vec<u8> {
+        create_compressed_metadata_file(sess, metadata, symbol_name)
+    }
+
     /// Creates a DLL Import Library <https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-creation#creating-an-import-library>.
     /// and returns the path on disk to that import library.
     /// This functions doesn't take `self` so that it can be called from
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 18b76b33757..8c52ed6ed12 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -23,7 +23,8 @@ use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_macros::LintDiagnostic;
 use rustc_metadata::fs::{METADATA_FILENAME, copy_to_stdout, emit_wrapper_file};
 use rustc_metadata::{
-    NativeLibSearchFallback, find_native_static_library, walk_native_lib_search_dirs,
+    EncodedMetadata, NativeLibSearchFallback, find_native_static_library,
+    walk_native_lib_search_dirs,
 };
 use rustc_middle::bug;
 use rustc_middle::lint::lint_level;
@@ -91,6 +92,7 @@ pub fn link_binary(
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
     codegen_results: CodegenResults,
+    metadata: EncodedMetadata,
     outputs: &OutputFilenames,
 ) {
     let _timer = sess.timer("link_binary");
@@ -142,6 +144,7 @@ pub fn link_binary(
                         sess,
                         archive_builder_builder,
                         &codegen_results,
+                        &metadata,
                         RlibFlavor::Normal,
                         &path,
                     )
@@ -152,6 +155,7 @@ pub fn link_binary(
                         sess,
                         archive_builder_builder,
                         &codegen_results,
+                        &metadata,
                         &out_filename,
                         &path,
                     );
@@ -163,6 +167,7 @@ pub fn link_binary(
                         crate_type,
                         &out_filename,
                         &codegen_results,
+                        &metadata,
                         path.as_ref(),
                     );
                 }
@@ -226,11 +231,7 @@ pub fn link_binary(
         let remove_temps_from_module =
             |module: &CompiledModule| maybe_remove_temps_from_module(false, false, module);
 
-        // Otherwise, always remove the metadata and allocator module temporaries.
-        if let Some(ref metadata_module) = codegen_results.metadata_module {
-            remove_temps_from_module(metadata_module);
-        }
-
+        // Otherwise, always remove the allocator module temporaries.
         if let Some(ref allocator_module) = codegen_results.allocator_module {
             remove_temps_from_module(allocator_module);
         }
@@ -312,6 +313,7 @@ fn link_rlib<'a>(
     sess: &'a Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
     codegen_results: &CodegenResults,
+    metadata: &EncodedMetadata,
     flavor: RlibFlavor,
     tmpdir: &MaybeTempDir,
 ) -> Box<dyn ArchiveBuilder + 'a> {
@@ -319,12 +321,9 @@ fn link_rlib<'a>(
 
     let trailing_metadata = match flavor {
         RlibFlavor::Normal => {
-            let (metadata, metadata_position) = create_wrapper_file(
-                sess,
-                ".rmeta".to_string(),
-                codegen_results.metadata.stub_or_full(),
-            );
-            let metadata = emit_wrapper_file(sess, &metadata, tmpdir, METADATA_FILENAME);
+            let (metadata, metadata_position) =
+                create_wrapper_file(sess, ".rmeta".to_string(), metadata.stub_or_full());
+            let metadata = emit_wrapper_file(sess, &metadata, tmpdir.as_ref(), METADATA_FILENAME);
             match metadata_position {
                 MetadataPosition::First => {
                     // Most of the time metadata in rlib files is wrapped in a "dummy" object
@@ -392,7 +391,7 @@ fn link_rlib<'a>(
             let src = read(path)
                 .unwrap_or_else(|e| sess.dcx().emit_fatal(errors::ReadFileError { message: e }));
             let (data, _) = create_wrapper_file(sess, ".bundled_lib".to_string(), &src);
-            let wrapper_file = emit_wrapper_file(sess, &data, tmpdir, filename.as_str());
+            let wrapper_file = emit_wrapper_file(sess, &data, tmpdir.as_ref(), filename.as_str());
             packed_bundled_libs.push(wrapper_file);
         } else {
             let path = find_native_static_library(lib.name.as_str(), lib.verbatim, sess);
@@ -473,6 +472,7 @@ fn link_staticlib(
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
     codegen_results: &CodegenResults,
+    metadata: &EncodedMetadata,
     out_filename: &Path,
     tempdir: &MaybeTempDir,
 ) {
@@ -481,6 +481,7 @@ fn link_staticlib(
         sess,
         archive_builder_builder,
         codegen_results,
+        metadata,
         RlibFlavor::StaticlibBase,
         tempdir,
     );
@@ -694,6 +695,7 @@ fn link_natively(
     crate_type: CrateType,
     out_filename: &Path,
     codegen_results: &CodegenResults,
+    metadata: &EncodedMetadata,
     tmpdir: &Path,
 ) {
     info!("preparing {:?} to {:?}", crate_type, out_filename);
@@ -718,6 +720,7 @@ fn link_natively(
         tmpdir,
         temp_filename,
         codegen_results,
+        metadata,
         self_contained_components,
     );
 
@@ -2095,17 +2098,25 @@ fn add_local_crate_allocator_objects(cmd: &mut dyn Linker, codegen_results: &Cod
 /// Add object files containing metadata for the current crate.
 fn add_local_crate_metadata_objects(
     cmd: &mut dyn Linker,
+    sess: &Session,
+    archive_builder_builder: &dyn ArchiveBuilderBuilder,
     crate_type: CrateType,
+    tmpdir: &Path,
     codegen_results: &CodegenResults,
+    metadata: &EncodedMetadata,
 ) {
     // When linking a dynamic library, we put the metadata into a section of the
     // executable. This metadata is in a separate object file from the main
-    // object file, so we link that in here.
-    if matches!(crate_type, CrateType::Dylib | CrateType::ProcMacro)
-        && let Some(m) = &codegen_results.metadata_module
-        && let Some(obj) = &m.object
-    {
-        cmd.add_object(obj);
+    // object file, so we create and link it in here.
+    if matches!(crate_type, CrateType::Dylib | CrateType::ProcMacro) {
+        let data = archive_builder_builder.create_dylib_metadata_wrapper(
+            sess,
+            &metadata,
+            &codegen_results.crate_info.metadata_symbol,
+        );
+        let obj = emit_wrapper_file(sess, &data, tmpdir, "rmeta.o");
+
+        cmd.add_object(&obj);
     }
 }
 
@@ -2195,6 +2206,7 @@ fn linker_with_args(
     tmpdir: &Path,
     out_filename: &Path,
     codegen_results: &CodegenResults,
+    metadata: &EncodedMetadata,
     self_contained_components: LinkSelfContainedComponents,
 ) -> Command {
     let self_contained_crt_objects = self_contained_components.is_crt_objects_enabled();
@@ -2269,7 +2281,15 @@ fn linker_with_args(
     // in this DAG so far because they can only depend on other native libraries
     // and such dependencies are also required to be specified.
     add_local_crate_regular_objects(cmd, codegen_results);
-    add_local_crate_metadata_objects(cmd, crate_type, codegen_results);
+    add_local_crate_metadata_objects(
+        cmd,
+        sess,
+        archive_builder_builder,
+        crate_type,
+        tmpdir,
+        codegen_results,
+        metadata,
+    );
     add_local_crate_allocator_objects(cmd, codegen_results);
 
     // Avoid linking to dynamic libraries unless they satisfy some undefined symbols
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index a41ca8ce28b..bbf9cceef2a 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -24,7 +24,6 @@ use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_incremental::{
     copy_cgu_workproduct_to_incr_comp_cache_dir, in_incr_comp_dir, in_incr_comp_dir_sess,
 };
-use rustc_metadata::EncodedMetadata;
 use rustc_metadata::fs::copy_to_stdout;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
@@ -142,7 +141,6 @@ impl ModuleConfig {
             || match kind {
                 ModuleKind::Regular => sess.opts.output_types.contains_key(&OutputType::Object),
                 ModuleKind::Allocator => false,
-                ModuleKind::Metadata => sess.opts.output_types.contains_key(&OutputType::Metadata),
             };
 
         let emit_obj = if !should_emit_obj {
@@ -350,7 +348,6 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     pub output_filenames: Arc<OutputFilenames>,
     pub invocation_temp: Option<String>,
     pub regular_module_config: Arc<ModuleConfig>,
-    pub metadata_module_config: Arc<ModuleConfig>,
     pub allocator_module_config: Arc<ModuleConfig>,
     pub tm_factory: TargetMachineFactoryFn<B>,
     pub msvc_imps_needed: bool,
@@ -395,7 +392,6 @@ impl<B: WriteBackendMethods> CodegenContext<B> {
     pub fn config(&self, kind: ModuleKind) -> &ModuleConfig {
         match kind {
             ModuleKind::Regular => &self.regular_module_config,
-            ModuleKind::Metadata => &self.metadata_module_config,
             ModuleKind::Allocator => &self.allocator_module_config,
         }
     }
@@ -474,8 +470,6 @@ pub(crate) fn start_async_codegen<B: ExtraBackendMethods>(
     backend: B,
     tcx: TyCtxt<'_>,
     target_cpu: String,
-    metadata: EncodedMetadata,
-    metadata_module: Option<CompiledModule>,
 ) -> OngoingCodegen<B> {
     let (coordinator_send, coordinator_receive) = channel();
 
@@ -485,7 +479,6 @@ pub(crate) fn start_async_codegen<B: ExtraBackendMethods>(
     let crate_info = CrateInfo::new(tcx, target_cpu);
 
     let regular_config = ModuleConfig::new(ModuleKind::Regular, tcx, no_builtins);
-    let metadata_config = ModuleConfig::new(ModuleKind::Metadata, tcx, no_builtins);
     let allocator_config = ModuleConfig::new(ModuleKind::Allocator, tcx, no_builtins);
 
     let (shared_emitter, shared_emitter_main) = SharedEmitter::new();
@@ -499,15 +492,12 @@ pub(crate) fn start_async_codegen<B: ExtraBackendMethods>(
         codegen_worker_send,
         coordinator_receive,
         Arc::new(regular_config),
-        Arc::new(metadata_config),
         Arc::new(allocator_config),
         coordinator_send.clone(),
     );
 
     OngoingCodegen {
         backend,
-        metadata,
-        metadata_module,
         crate_info,
 
         codegen_worker_receive,
@@ -843,12 +833,6 @@ pub(crate) fn compute_per_cgu_lto_type(
     sess_crate_types: &[CrateType],
     module_kind: ModuleKind,
 ) -> ComputedLtoType {
-    // Metadata modules never participate in LTO regardless of the lto
-    // settings.
-    if module_kind == ModuleKind::Metadata {
-        return ComputedLtoType::No;
-    }
-
     // If the linker does LTO, we don't have to do it. Note that we
     // keep doing full LTO, if it is requested, as not to break the
     // assumption that the output will be a single module.
@@ -1029,10 +1013,7 @@ fn finish_intra_module_work<B: ExtraBackendMethods>(
     let dcx = cgcx.create_dcx();
     let dcx = dcx.handle();
 
-    if !cgcx.opts.unstable_opts.combine_cgu
-        || module.kind == ModuleKind::Metadata
-        || module.kind == ModuleKind::Allocator
-    {
+    if !cgcx.opts.unstable_opts.combine_cgu || module.kind == ModuleKind::Allocator {
         let module = B::codegen(cgcx, dcx, module, module_config)?;
         Ok(WorkItemResult::Finished(module))
     } else {
@@ -1123,7 +1104,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
     codegen_worker_send: Sender<CguMessage>,
     coordinator_receive: Receiver<Box<dyn Any + Send>>,
     regular_config: Arc<ModuleConfig>,
-    metadata_config: Arc<ModuleConfig>,
     allocator_config: Arc<ModuleConfig>,
     tx_to_llvm_workers: Sender<Box<dyn Any + Send>>,
 ) -> thread::JoinHandle<Result<CompiledModules, ()>> {
@@ -1216,7 +1196,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
         diag_emitter: shared_emitter.clone(),
         output_filenames: Arc::clone(tcx.output_filenames(())),
         regular_module_config: regular_config,
-        metadata_module_config: metadata_config,
         allocator_module_config: allocator_config,
         tm_factory: backend.target_machine_factory(tcx.sess, ol, backend_features),
         msvc_imps_needed: msvc_imps_needed(tcx),
@@ -1673,7 +1652,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
                                     assert!(compiled_allocator_module.is_none());
                                     compiled_allocator_module = Some(compiled_module);
                                 }
-                                ModuleKind::Metadata => bug!("Should be handled separately"),
                             }
                         }
                         Ok(WorkItemResult::NeedsLink(module)) => {
@@ -2055,8 +2033,6 @@ impl<B: ExtraBackendMethods> Drop for Coordinator<B> {
 
 pub struct OngoingCodegen<B: ExtraBackendMethods> {
     pub backend: B,
-    pub metadata: EncodedMetadata,
-    pub metadata_module: Option<CompiledModule>,
     pub crate_info: CrateInfo,
     pub codegen_worker_receive: Receiver<CguMessage>,
     pub shared_emitter_main: SharedEmitterMain,
@@ -2096,12 +2072,10 @@ impl<B: ExtraBackendMethods> OngoingCodegen<B> {
 
         (
             CodegenResults {
-                metadata: self.metadata,
                 crate_info: self.crate_info,
 
                 modules: compiled_modules.modules,
                 allocator_module: compiled_modules.allocator_module,
-                metadata_module: self.metadata_module,
             },
             work_products,
         )
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index c2d6a26de0f..a3d6c73ba85 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -15,11 +15,10 @@ use rustc_data_structures::unord::UnordMap;
 use rustc_hir::ItemId;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::middle::debugger_visualizer::{DebuggerVisualizerFile, DebuggerVisualizerType};
-use rustc_middle::middle::exported_symbols::SymbolExportKind;
-use rustc_middle::middle::{exported_symbols, lang_items};
+use rustc_middle::middle::exported_symbols::{self, SymbolExportKind};
+use rustc_middle::middle::lang_items;
 use rustc_middle::mir::BinOp;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem, MonoItemPartitions};
@@ -28,7 +27,7 @@ use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_session::Session;
-use rustc_session::config::{self, CrateType, EntryFnType, OutputType};
+use rustc_session::config::{self, CrateType, EntryFnType};
 use rustc_span::{DUMMY_SP, Symbol, sym};
 use rustc_symbol_mangling::mangle_internal_symbol;
 use rustc_trait_selection::infer::{BoundRegionConversionTime, TyCtxtInferExt};
@@ -37,7 +36,6 @@ use tracing::{debug, info};
 
 use crate::assert_module_sources::CguReuse;
 use crate::back::link::are_upstream_rust_objects_already_included;
-use crate::back::metadata::create_compressed_metadata_file;
 use crate::back::write::{
     ComputedLtoType, OngoingCodegen, compute_per_cgu_lto_type, start_async_codegen,
     submit_codegened_module_to_llvm, submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm,
@@ -48,8 +46,7 @@ use crate::mir::operand::OperandValue;
 use crate::mir::place::PlaceRef;
 use crate::traits::*;
 use crate::{
-    CachedModuleCodegen, CodegenLintLevels, CompiledModule, CrateInfo, ModuleCodegen, ModuleKind,
-    errors, meth, mir,
+    CachedModuleCodegen, CodegenLintLevels, CrateInfo, ModuleCodegen, ModuleKind, errors, meth, mir,
 };
 
 pub(crate) fn bin_op_to_icmp_predicate(op: BinOp, signed: bool) -> IntPredicate {
@@ -669,12 +666,10 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
     backend: B,
     tcx: TyCtxt<'_>,
     target_cpu: String,
-    metadata: EncodedMetadata,
-    need_metadata_module: bool,
 ) -> OngoingCodegen<B> {
     // Skip crate items and just output metadata in -Z no-codegen mode.
     if tcx.sess.opts.unstable_opts.no_codegen || !tcx.sess.opts.output_types.should_codegen() {
-        let ongoing_codegen = start_async_codegen(backend, tcx, target_cpu, metadata, None);
+        let ongoing_codegen = start_async_codegen(backend, tcx, target_cpu);
 
         ongoing_codegen.codegen_finished(tcx);
 
@@ -707,39 +702,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         }
     }
 
-    let metadata_module = need_metadata_module.then(|| {
-        // Emit compressed metadata object.
-        let metadata_cgu_name =
-            cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata")).to_string();
-        tcx.sess.time("write_compressed_metadata", || {
-            let file_name = tcx.output_filenames(()).temp_path_for_cgu(
-                OutputType::Metadata,
-                &metadata_cgu_name,
-                tcx.sess.invocation_temp.as_deref(),
-            );
-            let data = create_compressed_metadata_file(
-                tcx.sess,
-                &metadata,
-                &exported_symbols::metadata_symbol_name(tcx),
-            );
-            if let Err(error) = std::fs::write(&file_name, data) {
-                tcx.dcx().emit_fatal(errors::MetadataObjectFileWrite { error });
-            }
-            CompiledModule {
-                name: metadata_cgu_name,
-                kind: ModuleKind::Metadata,
-                object: Some(file_name),
-                dwarf_object: None,
-                bytecode: None,
-                assembly: None,
-                llvm_ir: None,
-                links_from_incr_cache: Vec::new(),
-            }
-        })
-    });
-
-    let ongoing_codegen =
-        start_async_codegen(backend.clone(), tcx, target_cpu, metadata, metadata_module);
+    let ongoing_codegen = start_async_codegen(backend.clone(), tcx, target_cpu);
 
     // Codegen an allocator shim, if necessary.
     if let Some(kind) = allocator_kind_for_codegen(tcx) {
@@ -1010,6 +973,7 @@ impl CrateInfo {
             windows_subsystem,
             natvis_debugger_visualizers: Default::default(),
             lint_levels: CodegenLintLevels::from_tcx(tcx),
+            metadata_symbol: exported_symbols::metadata_symbol_name(tcx),
         };
 
         info.native_libraries.reserve(n_crates);
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index f843347db92..bac02bdf983 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -778,12 +778,6 @@ pub(crate) struct MultipleMainFunctions {
 }
 
 #[derive(Diagnostic)]
-#[diag(codegen_ssa_metadata_object_file_write)]
-pub(crate) struct MetadataObjectFileWrite {
-    pub error: Error,
-}
-
-#[derive(Diagnostic)]
 #[diag(codegen_ssa_invalid_windows_subsystem)]
 pub(crate) struct InvalidWindowsSubsystem {
     pub subsystem: Symbol,
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
index 84919645cf0..523c9f2ad1c 100644
--- a/compiler/rustc_codegen_ssa/src/lib.rs
+++ b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -31,6 +31,7 @@ use rustc_data_structures::unord::UnordMap;
 use rustc_hir::CRATE_HIR_ID;
 use rustc_hir::def_id::CrateNum;
 use rustc_macros::{Decodable, Encodable, HashStable};
+use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::WorkProduct;
 use rustc_middle::lint::LevelAndSource;
 use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerFile;
@@ -169,7 +170,6 @@ pub(crate) struct CachedModuleCodegen {
 #[derive(Copy, Clone, Debug, PartialEq, Encodable, Decodable)]
 pub enum ModuleKind {
     Regular,
-    Metadata,
     Allocator,
 }
 
@@ -233,6 +233,7 @@ pub struct CrateInfo {
     pub windows_subsystem: Option<String>,
     pub natvis_debugger_visualizers: BTreeSet<DebuggerVisualizerFile>,
     pub lint_levels: CodegenLintLevels,
+    pub metadata_symbol: String,
 }
 
 /// Target-specific options that get set in `cfg(...)`.
@@ -257,8 +258,6 @@ pub struct TargetConfig {
 pub struct CodegenResults {
     pub modules: Vec<CompiledModule>,
     pub allocator_module: Option<CompiledModule>,
-    pub metadata_module: Option<CompiledModule>,
-    pub metadata: rustc_metadata::EncodedMetadata,
     pub crate_info: CrateInfo,
 }
 
@@ -303,6 +302,7 @@ impl CodegenResults {
         sess: &Session,
         rlink_file: &Path,
         codegen_results: &CodegenResults,
+        metadata: &EncodedMetadata,
         outputs: &OutputFilenames,
     ) -> Result<usize, io::Error> {
         let mut encoder = FileEncoder::new(rlink_file)?;
@@ -312,6 +312,7 @@ impl CodegenResults {
         encoder.emit_raw_bytes(&RLINK_VERSION.to_be_bytes());
         encoder.emit_str(sess.cfg_version);
         Encodable::encode(codegen_results, &mut encoder);
+        Encodable::encode(metadata, &mut encoder);
         Encodable::encode(outputs, &mut encoder);
         encoder.finish().map_err(|(_path, err)| err)
     }
@@ -319,7 +320,7 @@ impl CodegenResults {
     pub fn deserialize_rlink(
         sess: &Session,
         data: Vec<u8>,
-    ) -> Result<(Self, OutputFilenames), CodegenErrors> {
+    ) -> Result<(Self, EncodedMetadata, OutputFilenames), CodegenErrors> {
         // The Decodable machinery is not used here because it panics if the input data is invalid
         // and because its internal representation may change.
         if !data.starts_with(RLINK_MAGIC) {
@@ -350,8 +351,9 @@ impl CodegenResults {
         }
 
         let codegen_results = CodegenResults::decode(&mut decoder);
+        let metadata = EncodedMetadata::decode(&mut decoder);
         let outputs = OutputFilenames::decode(&mut decoder);
-        Ok((codegen_results, outputs))
+        Ok((codegen_results, metadata, outputs))
     }
 }
 
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 43b87171d51..3df97429e09 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -1,6 +1,6 @@
 use std::cmp;
 
-use rustc_abi::{BackendRepr, ExternAbi, HasDataLayout, Reg, Size, WrappingRange};
+use rustc_abi::{Align, BackendRepr, ExternAbi, HasDataLayout, Reg, Size, WrappingRange};
 use rustc_ast as ast;
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_data_structures::packed::Pu128;
@@ -13,7 +13,7 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::config::OptLevel;
 use rustc_span::Span;
 use rustc_span::source_map::Spanned;
-use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
+use rustc_target::callconv::{ArgAbi, CastTarget, FnAbi, PassMode};
 use tracing::{debug, info};
 
 use super::operand::OperandRef;
@@ -558,8 +558,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     }
                     ZeroSized => bug!("ZST return value shouldn't be in PassMode::Cast"),
                 };
-                let ty = bx.cast_backend_type(cast_ty);
-                bx.load(ty, llslot, self.fn_abi.ret.layout.align.abi)
+                load_cast(bx, cast_ty, llslot, self.fn_abi.ret.layout.align.abi)
             }
         };
         bx.ret(llval);
@@ -1618,8 +1617,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     MemFlags::empty(),
                 );
                 // ...and then load it with the ABI type.
-                let cast_ty = bx.cast_backend_type(cast);
-                llval = bx.load(cast_ty, llscratch, scratch_align);
+                llval = load_cast(bx, cast, llscratch, scratch_align);
                 bx.lifetime_end(llscratch, scratch_size);
             } else {
                 // We can't use `PlaceRef::load` here because the argument
@@ -1969,3 +1967,47 @@ enum ReturnDest<'tcx, V> {
     /// Store a direct return value to an operand local place.
     DirectOperand(mir::Local),
 }
+
+fn load_cast<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &mut Bx,
+    cast: &CastTarget,
+    ptr: Bx::Value,
+    align: Align,
+) -> Bx::Value {
+    let cast_ty = bx.cast_backend_type(cast);
+    if let Some(offset_from_start) = cast.rest_offset {
+        assert!(cast.prefix[1..].iter().all(|p| p.is_none()));
+        assert_eq!(cast.rest.unit.size, cast.rest.total);
+        let first_ty = bx.reg_backend_type(&cast.prefix[0].unwrap());
+        let second_ty = bx.reg_backend_type(&cast.rest.unit);
+        let first = bx.load(first_ty, ptr, align);
+        let second_ptr = bx.inbounds_ptradd(ptr, bx.const_usize(offset_from_start.bytes()));
+        let second = bx.load(second_ty, second_ptr, align.restrict_for_offset(offset_from_start));
+        let res = bx.cx().const_poison(cast_ty);
+        let res = bx.insert_value(res, first, 0);
+        bx.insert_value(res, second, 1)
+    } else {
+        bx.load(cast_ty, ptr, align)
+    }
+}
+
+pub fn store_cast<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &mut Bx,
+    cast: &CastTarget,
+    value: Bx::Value,
+    ptr: Bx::Value,
+    align: Align,
+) {
+    if let Some(offset_from_start) = cast.rest_offset {
+        assert!(cast.prefix[1..].iter().all(|p| p.is_none()));
+        assert_eq!(cast.rest.unit.size, cast.rest.total);
+        assert!(cast.prefix[0].is_some());
+        let first = bx.extract_value(value, 0);
+        let second = bx.extract_value(value, 1);
+        bx.store(first, ptr, align);
+        let second_ptr = bx.inbounds_ptradd(ptr, bx.const_usize(offset_from_start.bytes()));
+        bx.store(second, second_ptr, align.restrict_for_offset(offset_from_start));
+    } else {
+        bx.store(value, ptr, align);
+    };
+}
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index 96a04473aba..66c4af4c935 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -26,6 +26,7 @@ pub mod place;
 mod rvalue;
 mod statement;
 
+pub use self::block::store_cast;
 use self::debuginfo::{FunctionDebugContext, PerLocalVarDebugInfo};
 use self::operand::{OperandRef, OperandValue};
 use self::place::PlaceRef;
@@ -259,7 +260,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
                     }
                     PassMode::Cast { ref cast, .. } => {
                         debug!("alloc: {:?} (return place) -> place", local);
-                        let size = cast.size(&start_bx);
+                        let size = cast.size(&start_bx).max(layout.size);
                         return LocalRef::Place(PlaceRef::alloca_size(&mut start_bx, size, layout));
                     }
                     _ => {}
diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
index 46fb9a89513..b805dc094e9 100644
--- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
@@ -1,14 +1,13 @@
 use rustc_abi::{BackendRepr, Float, Integer, Primitive, RegKind};
 use rustc_attr_data_structures::InstructionSetAttr;
-use rustc_hir::def_id::DefId;
 use rustc_middle::mir::mono::{Linkage, MonoItemData, Visibility};
 use rustc_middle::mir::{InlineAsmOperand, START_BLOCK};
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{Instance, Ty, TyCtxt, TypeVisitableExt};
-use rustc_middle::{bug, span_bug, ty};
+use rustc_middle::{bug, ty};
 use rustc_span::sym;
 use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
-use rustc_target::spec::{BinaryFormat, WasmCAbi};
+use rustc_target::spec::BinaryFormat;
 
 use crate::common;
 use crate::mir::AsmCodegenMethods;
@@ -287,12 +286,7 @@ fn prefix_and_suffix<'tcx>(
                 writeln!(begin, "{}", arch_prefix).unwrap();
             }
             writeln!(begin, "{asm_name}:").unwrap();
-            writeln!(
-                begin,
-                ".functype {asm_name} {}",
-                wasm_functype(tcx, fn_abi, instance.def_id())
-            )
-            .unwrap();
+            writeln!(begin, ".functype {asm_name} {}", wasm_functype(tcx, fn_abi)).unwrap();
 
             writeln!(end).unwrap();
             // .size is ignored for function symbols, so we can skip it
@@ -333,7 +327,7 @@ fn prefix_and_suffix<'tcx>(
 /// The webassembly type signature for the given function.
 ///
 /// Used by the `.functype` directive on wasm targets.
-fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id: DefId) -> String {
+fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> String {
     let mut signature = String::with_capacity(64);
 
     let ptr_type = match tcx.data_layout.pointer_size.bits() {
@@ -342,17 +336,6 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id
         other => bug!("wasm pointer size cannot be {other} bits"),
     };
 
-    // FIXME: remove this once the wasm32-unknown-unknown ABI is fixed
-    // please also add `wasm32-unknown-unknown` back in `tests/assembly/wasm32-naked-fn.rs`
-    // basically the commit introducing this comment should be reverted
-    if let PassMode::Pair { .. } = fn_abi.ret.mode {
-        let _ = WasmCAbi::Legacy { with_lint: true };
-        span_bug!(
-            tcx.def_span(def_id),
-            "cannot return a pair (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666"
-        );
-    }
-
     let hidden_return = matches!(fn_abi.ret.mode, PassMode::Indirect { .. });
 
     signature.push('(');
@@ -366,7 +349,7 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id
 
     let mut it = fn_abi.args.iter().peekable();
     while let Some(arg_abi) = it.next() {
-        wasm_type(tcx, &mut signature, arg_abi, ptr_type, def_id);
+        wasm_type(&mut signature, arg_abi, ptr_type);
         if it.peek().is_some() {
             signature.push_str(", ");
         }
@@ -375,7 +358,7 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id
     signature.push_str(") -> (");
 
     if !hidden_return {
-        wasm_type(tcx, &mut signature, &fn_abi.ret, ptr_type, def_id);
+        wasm_type(&mut signature, &fn_abi.ret, ptr_type);
     }
 
     signature.push(')');
@@ -383,27 +366,13 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id
     signature
 }
 
-fn wasm_type<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    signature: &mut String,
-    arg_abi: &ArgAbi<'_, Ty<'tcx>>,
-    ptr_type: &'static str,
-    def_id: DefId,
-) {
+fn wasm_type<'tcx>(signature: &mut String, arg_abi: &ArgAbi<'_, Ty<'tcx>>, ptr_type: &'static str) {
     match arg_abi.mode {
         PassMode::Ignore => { /* do nothing */ }
         PassMode::Direct(_) => {
             let direct_type = match arg_abi.layout.backend_repr {
                 BackendRepr::Scalar(scalar) => wasm_primitive(scalar.primitive(), ptr_type),
                 BackendRepr::SimdVector { .. } => "v128",
-                BackendRepr::Memory { .. } => {
-                    // FIXME: remove this branch once the wasm32-unknown-unknown ABI is fixed
-                    let _ = WasmCAbi::Legacy { with_lint: true };
-                    span_bug!(
-                        tcx.def_span(def_id),
-                        "cannot use memory args (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666"
-                    );
-                }
                 other => unreachable!("unexpected BackendRepr: {:?}", other),
             };
 
diff --git a/compiler/rustc_codegen_ssa/src/traits/backend.rs b/compiler/rustc_codegen_ssa/src/traits/backend.rs
index 95bf3b16685..29ec7eb1da3 100644
--- a/compiler/rustc_codegen_ssa/src/traits/backend.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/backend.rs
@@ -74,12 +74,7 @@ pub trait CodegenBackend {
 
     fn provide(&self, _providers: &mut Providers) {}
 
-    fn codegen_crate<'tcx>(
-        &self,
-        tcx: TyCtxt<'tcx>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any>;
+    fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Box<dyn Any>;
 
     /// This is called on the returned `Box<dyn Any>` from [`codegen_crate`](Self::codegen_crate)
     ///
@@ -94,8 +89,14 @@ pub trait CodegenBackend {
     ) -> (CodegenResults, FxIndexMap<WorkProductId, WorkProduct>);
 
     /// This is called on the returned [`CodegenResults`] from [`join_codegen`](Self::join_codegen).
-    fn link(&self, sess: &Session, codegen_results: CodegenResults, outputs: &OutputFilenames) {
-        link_binary(sess, &ArArchiveBuilderBuilder, codegen_results, outputs);
+    fn link(
+        &self,
+        sess: &Session,
+        codegen_results: CodegenResults,
+        metadata: EncodedMetadata,
+        outputs: &OutputFilenames,
+    ) {
+        link_binary(sess, &ArArchiveBuilderBuilder, codegen_results, metadata, outputs);
     }
 }
 
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 0cd9e36a927..d53126d0414 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -557,27 +557,34 @@ fn process_rlink(sess: &Session, compiler: &interface::Compiler) {
         let rlink_data = fs::read(file).unwrap_or_else(|err| {
             dcx.emit_fatal(RlinkUnableToRead { err });
         });
-        let (codegen_results, outputs) = match CodegenResults::deserialize_rlink(sess, rlink_data) {
-            Ok((codegen, outputs)) => (codegen, outputs),
-            Err(err) => {
-                match err {
-                    CodegenErrors::WrongFileType => dcx.emit_fatal(RLinkWrongFileType),
-                    CodegenErrors::EmptyVersionNumber => dcx.emit_fatal(RLinkEmptyVersionNumber),
-                    CodegenErrors::EncodingVersionMismatch { version_array, rlink_version } => dcx
-                        .emit_fatal(RLinkEncodingVersionMismatch { version_array, rlink_version }),
-                    CodegenErrors::RustcVersionMismatch { rustc_version } => {
-                        dcx.emit_fatal(RLinkRustcVersionMismatch {
-                            rustc_version,
-                            current_version: sess.cfg_version,
-                        })
-                    }
-                    CodegenErrors::CorruptFile => {
-                        dcx.emit_fatal(RlinkCorruptFile { file });
-                    }
-                };
-            }
-        };
-        compiler.codegen_backend.link(sess, codegen_results, &outputs);
+        let (codegen_results, metadata, outputs) =
+            match CodegenResults::deserialize_rlink(sess, rlink_data) {
+                Ok((codegen, metadata, outputs)) => (codegen, metadata, outputs),
+                Err(err) => {
+                    match err {
+                        CodegenErrors::WrongFileType => dcx.emit_fatal(RLinkWrongFileType),
+                        CodegenErrors::EmptyVersionNumber => {
+                            dcx.emit_fatal(RLinkEmptyVersionNumber)
+                        }
+                        CodegenErrors::EncodingVersionMismatch { version_array, rlink_version } => {
+                            dcx.emit_fatal(RLinkEncodingVersionMismatch {
+                                version_array,
+                                rlink_version,
+                            })
+                        }
+                        CodegenErrors::RustcVersionMismatch { rustc_version } => {
+                            dcx.emit_fatal(RLinkRustcVersionMismatch {
+                                rustc_version,
+                                current_version: sess.cfg_version,
+                            })
+                        }
+                        CodegenErrors::CorruptFile => {
+                            dcx.emit_fatal(RlinkCorruptFile { file });
+                        }
+                    };
+                }
+            };
+        compiler.codegen_backend.link(sess, codegen_results, metadata, &outputs);
     } else {
         dcx.emit_fatal(RlinkNotAFile {});
     }
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 311dadb53c4..7a29f8c9fbd 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -35,6 +35,7 @@ use crate::base::ast::MetaItemInner;
 use crate::errors;
 use crate::expand::{self, AstFragment, Invocation};
 use crate::module::DirOwnership;
+use crate::stats::MacroStat;
 
 // When adding new variants, make sure to
 // adjust the `visit_*` / `flat_map_*` calls in `InvocationCollector`
@@ -1191,7 +1192,7 @@ pub struct ExtCtxt<'a> {
     /// not to expand it again.
     pub(super) expanded_inert_attrs: MarkedAttrs,
     /// `-Zmacro-stats` data.
-    pub macro_stats: FxHashMap<(Symbol, MacroKind), crate::stats::MacroStat>, // njn: quals
+    pub macro_stats: FxHashMap<(Symbol, MacroKind), MacroStat>,
 }
 
 impl<'a> ExtCtxt<'a> {
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 73a21789c5d..7d6e471e7e9 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -887,7 +887,7 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         rustc_legacy_const_generics, Normal, template!(List: "N"), ErrorFollowing,
         EncodeCrossCrate::Yes,
     ),
-    // Do not const-check this function's body. It will always get replaced during CTFE.
+    // Do not const-check this function's body. It will always get replaced during CTFE via `hook_special_const_fn`.
     rustc_attr!(
         rustc_do_not_const_check, Normal, template!(Word), WarnFollowing,
         EncodeCrossCrate::Yes, "`#[rustc_do_not_const_check]` skips const-check for this function's body",
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 336bf0d93fd..556f50a85af 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2285,12 +2285,23 @@ pub struct Expr<'hir> {
 }
 
 impl Expr<'_> {
-    pub fn precedence(&self) -> ExprPrecedence {
+    pub fn precedence(
+        &self,
+        for_each_attr: &dyn Fn(HirId, &mut dyn FnMut(&Attribute)),
+    ) -> ExprPrecedence {
+        let prefix_attrs_precedence = || -> ExprPrecedence {
+            let mut has_outer_attr = false;
+            for_each_attr(self.hir_id, &mut |attr: &Attribute| {
+                has_outer_attr |= matches!(attr.style(), AttrStyle::Outer)
+            });
+            if has_outer_attr { ExprPrecedence::Prefix } else { ExprPrecedence::Unambiguous }
+        };
+
         match &self.kind {
             ExprKind::Closure(closure) => {
                 match closure.fn_decl.output {
                     FnRetTy::DefaultReturn(_) => ExprPrecedence::Jump,
-                    FnRetTy::Return(_) => ExprPrecedence::Unambiguous,
+                    FnRetTy::Return(_) => prefix_attrs_precedence(),
                 }
             }
 
@@ -2315,7 +2326,7 @@ impl Expr<'_> {
             | ExprKind::Let(..)
             | ExprKind::Unary(..) => ExprPrecedence::Prefix,
 
-            // Never need parens
+            // Need parens if and only if there are prefix attributes.
             ExprKind::Array(_)
             | ExprKind::Block(..)
             | ExprKind::Call(..)
@@ -2337,9 +2348,9 @@ impl Expr<'_> {
             | ExprKind::Type(..)
             | ExprKind::UnsafeBinderCast(..)
             | ExprKind::Use(..)
-            | ExprKind::Err(_) => ExprPrecedence::Unambiguous,
+            | ExprKind::Err(_) => prefix_attrs_precedence(),
 
-            ExprKind::DropTemps(expr, ..) => expr.precedence(),
+            ExprKind::DropTemps(expr, ..) => expr.precedence(for_each_attr),
         }
     }
 
@@ -3064,6 +3075,7 @@ pub struct TraitItem<'hir> {
     pub kind: TraitItemKind<'hir>,
     pub span: Span,
     pub defaultness: Defaultness,
+    pub has_delayed_lints: bool,
 }
 
 macro_rules! expect_methods_self_kind {
@@ -3168,6 +3180,7 @@ pub struct ImplItem<'hir> {
     pub defaultness: Defaultness,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl<'hir> ImplItem<'hir> {
@@ -4087,6 +4100,7 @@ pub struct Item<'hir> {
     pub kind: ItemKind<'hir>,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl<'hir> Item<'hir> {
@@ -4492,6 +4506,7 @@ pub struct ForeignItem<'hir> {
     pub owner_id: OwnerId,
     pub span: Span,
     pub vis_span: Span,
+    pub has_delayed_lints: bool,
 }
 
 impl ForeignItem<'_> {
@@ -4974,7 +4989,7 @@ mod size_asserts {
     static_assert_size!(Expr<'_>, 64);
     static_assert_size!(ExprKind<'_>, 48);
     static_assert_size!(FnDecl<'_>, 40);
-    static_assert_size!(ForeignItem<'_>, 88);
+    static_assert_size!(ForeignItem<'_>, 96);
     static_assert_size!(ForeignItemKind<'_>, 56);
     static_assert_size!(GenericArg<'_>, 16);
     static_assert_size!(GenericBound<'_>, 64);
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index bebac3a4b78..57e49625148 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -537,7 +537,7 @@ pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) ->
 }
 
 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) -> V::Result {
-    let Item { owner_id: _, kind, span: _, vis_span: _ } = item;
+    let Item { owner_id: _, kind, span: _, vis_span: _, has_delayed_lints: _ } = item;
     try_visit!(visitor.visit_id(item.hir_id()));
     match *kind {
         ItemKind::ExternCrate(orig_name, ident) => {
@@ -656,7 +656,8 @@ pub fn walk_foreign_item<'v, V: Visitor<'v>>(
     visitor: &mut V,
     foreign_item: &'v ForeignItem<'v>,
 ) -> V::Result {
-    let ForeignItem { ident, kind, owner_id: _, span: _, vis_span: _ } = foreign_item;
+    let ForeignItem { ident, kind, owner_id: _, span: _, vis_span: _, has_delayed_lints: _ } =
+        foreign_item;
     try_visit!(visitor.visit_id(foreign_item.hir_id()));
     try_visit!(visitor.visit_ident(*ident));
 
@@ -1205,7 +1206,15 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(
     visitor: &mut V,
     trait_item: &'v TraitItem<'v>,
 ) -> V::Result {
-    let TraitItem { ident, generics, ref defaultness, ref kind, span, owner_id: _ } = *trait_item;
+    let TraitItem {
+        ident,
+        generics,
+        ref defaultness,
+        ref kind,
+        span,
+        owner_id: _,
+        has_delayed_lints: _,
+    } = *trait_item;
     let hir_id = trait_item.hir_id();
     try_visit!(visitor.visit_ident(ident));
     try_visit!(visitor.visit_generics(&generics));
@@ -1261,6 +1270,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(
         ref defaultness,
         span: _,
         vis_span: _,
+        has_delayed_lints: _,
     } = *impl_item;
 
     try_visit!(visitor.visit_ident(ident));
diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
index f768bd157ab..bd2252c1bf8 100644
--- a/compiler/rustc_hir_analysis/messages.ftl
+++ b/compiler/rustc_hir_analysis/messages.ftl
@@ -46,6 +46,9 @@ hir_analysis_associated_type_trait_uninferred_generic_params = cannot use the {$
 
 hir_analysis_associated_type_trait_uninferred_generic_params_multipart_suggestion = use a fully qualified path with explicit lifetimes
 
+hir_analysis_async_drop_without_sync_drop = `AsyncDrop` impl without `Drop` impl
+    .help = type implementing `AsyncDrop` trait must also implement `Drop` trait to be used in sync context and unwinds
+
 hir_analysis_auto_deref_reached_recursion_limit = reached the recursion limit while auto-dereferencing `{$ty}`
     .label = deref recursion limit reached
     .help = consider increasing the recursion limit by adding a `#![recursion_limit = "{$suggested_limit}"]` attribute to your crate (`{$crate_name}`)
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index c5c7e6b2aa7..de8cbc3a57f 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -113,7 +113,15 @@ pub fn provide(providers: &mut Providers) {
 }
 
 fn adt_destructor(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::Destructor> {
-    tcx.calculate_dtor(def_id, always_applicable::check_drop_impl)
+    let dtor = tcx.calculate_dtor(def_id, always_applicable::check_drop_impl);
+    if dtor.is_none() && tcx.features().async_drop() {
+        if let Some(async_dtor) = adt_async_destructor(tcx, def_id) {
+            // When type has AsyncDrop impl, but doesn't have Drop impl, generate error
+            let span = tcx.def_span(async_dtor.impl_did);
+            tcx.dcx().emit_err(errors::AsyncDropWithoutSyncDrop { span });
+        }
+    }
+    dtor
 }
 
 fn adt_async_destructor(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::AsyncDestructor> {
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 8de2aec95a7..318aaab50f4 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -1712,3 +1712,11 @@ pub(crate) struct AbiCustomClothedFunction {
     )]
     pub naked_span: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_analysis_async_drop_without_sync_drop)]
+#[help]
+pub(crate) struct AsyncDropWithoutSyncDrop {
+    #[primary_span]
+    pub span: Span,
+}
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 4f699462ac3..7c8c9425a03 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -193,13 +193,41 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         let _: R = tcx.ensure_ok().crate_inherent_impls_overlap_check(());
     });
 
-    for owner_id in tcx.hir_crate_items(()).owners() {
-        if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
-            for lint in &delayed_lints.lints {
-                emit_delayed_lint(lint, tcx);
+    tcx.sess.time("emit_ast_lowering_delayed_lints", || {
+        // sanity check in debug mode that all lints are really noticed
+        // and we really will emit them all in the loop right below.
+        //
+        // during ast lowering, when creating items, foreign items, trait items and impl items
+        // we store in them whether they have any lints in their owner node that should be
+        // picked up by `hir_crate_items`. However, theoretically code can run between that
+        // boolean being inserted into the item and the owner node being created.
+        // We don't want any new lints to be emitted there
+        // (though honestly, you have to really try to manage to do that but still),
+        // but this check is there to catch that.
+        #[cfg(debug_assertions)]
+        {
+            // iterate over all owners
+            for owner_id in tcx.hir_crate_items(()).owners() {
+                // if it has delayed lints
+                if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
+                    if !delayed_lints.lints.is_empty() {
+                        // assert that delayed_lint_items also picked up this item to have lints
+                        assert!(
+                            tcx.hir_crate_items(()).delayed_lint_items().any(|i| i == owner_id)
+                        );
+                    }
+                }
             }
         }
-    }
+
+        for owner_id in tcx.hir_crate_items(()).delayed_lint_items() {
+            if let Some(delayed_lints) = tcx.opt_ast_lowering_delayed_lints(owner_id) {
+                for lint in &delayed_lints.lints {
+                    emit_delayed_lint(lint, tcx);
+                }
+            }
+        }
+    });
 
     tcx.par_hir_body_owners(|item_def_id| {
         let def_kind = tcx.def_kind(item_def_id);
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
index b23b3125c59..fc507285860 100644
--- a/compiler/rustc_hir_pretty/src/lib.rs
+++ b/compiler/rustc_hir_pretty/src/lib.rs
@@ -80,6 +80,13 @@ impl<'a> State<'a> {
         (self.attrs)(id)
     }
 
+    fn precedence(&self, expr: &hir::Expr<'_>) -> ExprPrecedence {
+        let for_each_attr = |id: HirId, callback: &mut dyn FnMut(&hir::Attribute)| {
+            self.attrs(id).iter().for_each(callback);
+        };
+        expr.precedence(&for_each_attr)
+    }
+
     fn print_attrs_as_inner(&mut self, attrs: &[hir::Attribute]) {
         self.print_either_attributes(attrs, ast::AttrStyle::Inner)
     }
@@ -1164,7 +1171,7 @@ impl<'a> State<'a> {
         }
         self.space();
         self.word_space("=");
-        let npals = || parser::needs_par_as_let_scrutinee(init.precedence());
+        let npals = || parser::needs_par_as_let_scrutinee(self.precedence(init));
         self.print_expr_cond_paren(init, Self::cond_needs_par(init) || npals())
     }
 
@@ -1265,7 +1272,7 @@ impl<'a> State<'a> {
     fn print_expr_call(&mut self, func: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
         let needs_paren = match func.kind {
             hir::ExprKind::Field(..) => true,
-            _ => func.precedence() < ExprPrecedence::Unambiguous,
+            _ => self.precedence(func) < ExprPrecedence::Unambiguous,
         };
 
         self.print_expr_cond_paren(func, needs_paren);
@@ -1279,7 +1286,10 @@ impl<'a> State<'a> {
         args: &[hir::Expr<'_>],
     ) {
         let base_args = args;
-        self.print_expr_cond_paren(receiver, receiver.precedence() < ExprPrecedence::Unambiguous);
+        self.print_expr_cond_paren(
+            receiver,
+            self.precedence(receiver) < ExprPrecedence::Unambiguous,
+        );
         self.word(".");
         self.print_ident(segment.ident);
 
@@ -1293,8 +1303,8 @@ impl<'a> State<'a> {
 
     fn print_expr_binary(&mut self, op: hir::BinOpKind, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>) {
         let binop_prec = op.precedence();
-        let left_prec = lhs.precedence();
-        let right_prec = rhs.precedence();
+        let left_prec = self.precedence(lhs);
+        let right_prec = self.precedence(rhs);
 
         let (mut left_needs_paren, right_needs_paren) = match op.fixity() {
             Fixity::Left => (left_prec < binop_prec, right_prec <= binop_prec),
@@ -1323,7 +1333,7 @@ impl<'a> State<'a> {
 
     fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr<'_>) {
         self.word(op.as_str());
-        self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Prefix);
+        self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Prefix);
     }
 
     fn print_expr_addr_of(
@@ -1340,7 +1350,7 @@ impl<'a> State<'a> {
                 self.print_mutability(mutability, true);
             }
         }
-        self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Prefix);
+        self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Prefix);
     }
 
     fn print_literal(&mut self, lit: &hir::Lit) {
@@ -1483,7 +1493,7 @@ impl<'a> State<'a> {
                 self.print_literal(lit);
             }
             hir::ExprKind::Cast(expr, ty) => {
-                self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Cast);
+                self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Cast);
                 self.space();
                 self.word_space("as");
                 self.print_type(ty);
@@ -1580,24 +1590,30 @@ impl<'a> State<'a> {
                 self.print_block(blk, cb, ib);
             }
             hir::ExprKind::Assign(lhs, rhs, _) => {
-                self.print_expr_cond_paren(lhs, lhs.precedence() <= ExprPrecedence::Assign);
+                self.print_expr_cond_paren(lhs, self.precedence(lhs) <= ExprPrecedence::Assign);
                 self.space();
                 self.word_space("=");
-                self.print_expr_cond_paren(rhs, rhs.precedence() < ExprPrecedence::Assign);
+                self.print_expr_cond_paren(rhs, self.precedence(rhs) < ExprPrecedence::Assign);
             }
             hir::ExprKind::AssignOp(op, lhs, rhs) => {
-                self.print_expr_cond_paren(lhs, lhs.precedence() <= ExprPrecedence::Assign);
+                self.print_expr_cond_paren(lhs, self.precedence(lhs) <= ExprPrecedence::Assign);
                 self.space();
                 self.word_space(op.node.as_str());
-                self.print_expr_cond_paren(rhs, rhs.precedence() < ExprPrecedence::Assign);
+                self.print_expr_cond_paren(rhs, self.precedence(rhs) < ExprPrecedence::Assign);
             }
             hir::ExprKind::Field(expr, ident) => {
-                self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Unambiguous);
+                self.print_expr_cond_paren(
+                    expr,
+                    self.precedence(expr) < ExprPrecedence::Unambiguous,
+                );
                 self.word(".");
                 self.print_ident(ident);
             }
             hir::ExprKind::Index(expr, index, _) => {
-                self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Unambiguous);
+                self.print_expr_cond_paren(
+                    expr,
+                    self.precedence(expr) < ExprPrecedence::Unambiguous,
+                );
                 self.word("[");
                 self.print_expr(index);
                 self.word("]");
@@ -1611,7 +1627,7 @@ impl<'a> State<'a> {
                 }
                 if let Some(expr) = opt_expr {
                     self.space();
-                    self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Jump);
+                    self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Jump);
                 }
             }
             hir::ExprKind::Continue(destination) => {
@@ -1625,13 +1641,13 @@ impl<'a> State<'a> {
                 self.word("return");
                 if let Some(expr) = result {
                     self.word(" ");
-                    self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Jump);
+                    self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Jump);
                 }
             }
             hir::ExprKind::Become(result) => {
                 self.word("become");
                 self.word(" ");
-                self.print_expr_cond_paren(result, result.precedence() < ExprPrecedence::Jump);
+                self.print_expr_cond_paren(result, self.precedence(result) < ExprPrecedence::Jump);
             }
             hir::ExprKind::InlineAsm(asm) => {
                 self.word("asm!");
@@ -1669,7 +1685,7 @@ impl<'a> State<'a> {
             }
             hir::ExprKind::Yield(expr, _) => {
                 self.word_space("yield");
-                self.print_expr_cond_paren(expr, expr.precedence() < ExprPrecedence::Jump);
+                self.print_expr_cond_paren(expr, self.precedence(expr) < ExprPrecedence::Jump);
             }
             hir::ExprKind::Err(_) => {
                 self.popen();
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index e915b4fc626..80bff09d0a4 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -620,7 +620,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             };
 
             if let Ok(rest_snippet) = rest_snippet {
-                let sugg = if callee_expr.precedence() >= ExprPrecedence::Unambiguous {
+                let sugg = if self.precedence(callee_expr) >= ExprPrecedence::Unambiguous {
                     vec![
                         (up_to_rcvr_span, "".to_string()),
                         (rest_span, format!(".{}({rest_snippet}", segment.ident)),
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index e17cfc15a43..6f8abc1e67d 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -1100,7 +1100,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
     }
 
     fn lossy_provenance_ptr2int_lint(&self, fcx: &FnCtxt<'a, 'tcx>, t_c: ty::cast::IntTy) {
-        let expr_prec = self.expr.precedence();
+        let expr_prec = fcx.precedence(self.expr);
         let needs_parens = expr_prec < ExprPrecedence::Unambiguous;
 
         let needs_cast = !matches!(t_c, ty::cast::IntTy::U(ty::UintTy::Usize));
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 30bf557dc93..55c39d960e7 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -6,6 +6,7 @@
 //! See [`rustc_hir_analysis::check`] for more context on type checking in general.
 
 use rustc_abi::{ExternAbi, FIRST_VARIANT, FieldIdx};
+use rustc_ast::util::parser::ExprPrecedence;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::unord::UnordMap;
@@ -17,7 +18,7 @@ use rustc_errors::{
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{ExprKind, HirId, QPath};
+use rustc_hir::{Attribute, ExprKind, HirId, QPath};
 use rustc_hir_analysis::NoVariantNamed;
 use rustc_hir_analysis::hir_ty_lowering::{FeedConstTy, HirTyLowerer as _};
 use rustc_infer::infer;
@@ -54,6 +55,30 @@ use crate::{
 };
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
+    pub(crate) fn precedence(&self, expr: &hir::Expr<'_>) -> ExprPrecedence {
+        let for_each_attr = |id: HirId, callback: &mut dyn FnMut(&Attribute)| {
+            for attr in self.tcx.hir_attrs(id) {
+                // For the purpose of rendering suggestions, disregard attributes
+                // that originate from desugaring of any kind. For example, `x?`
+                // desugars to `#[allow(unreachable_code)] match ...`. Failing to
+                // ignore the prefix attribute in the desugaring would cause this
+                // suggestion:
+                //
+                //     let y: u32 = x?.try_into().unwrap();
+                //                    ++++++++++++++++++++
+                //
+                // to be rendered as:
+                //
+                //     let y: u32 = (x?).try_into().unwrap();
+                //                  +  +++++++++++++++++++++
+                if attr.span().desugaring_kind().is_none() {
+                    callback(attr);
+                }
+            }
+        };
+        expr.precedence(&for_each_attr)
+    }
+
     /// Check an expr with an expectation type, and also demand that the expr's
     /// evaluated type is a subtype of the expectation at the end. This is a
     /// *hard* requirement.
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 66af085cfd4..7e5f1d97a8b 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -399,7 +399,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // so we remove the user's `clone` call.
                     {
                         vec![(receiver_method.ident.span, conversion_method_name.to_string())]
-                    } else if expr.precedence() < ExprPrecedence::Unambiguous {
+                    } else if self.precedence(expr) < ExprPrecedence::Unambiguous {
                         vec![
                             (expr.span.shrink_to_lo(), "(".to_string()),
                             (expr.span.shrink_to_hi(), format!(").{}()", conversion_method_name)),
@@ -1395,7 +1395,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         {
             let span = expr.span.find_oldest_ancestor_in_same_ctxt();
 
-            let mut sugg = if expr.precedence() >= ExprPrecedence::Unambiguous {
+            let mut sugg = if self.precedence(expr) >= ExprPrecedence::Unambiguous {
                 vec![(span.shrink_to_hi(), ".into()".to_owned())]
             } else {
                 vec![
@@ -3106,7 +3106,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             "change the type of the numeric literal from `{checked_ty}` to `{expected_ty}`",
         );
 
-        let close_paren = if expr.precedence() < ExprPrecedence::Unambiguous {
+        let close_paren = if self.precedence(expr) < ExprPrecedence::Unambiguous {
             sugg.push((expr.span.shrink_to_lo(), "(".to_string()));
             ")"
         } else {
@@ -3131,7 +3131,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let len = src.trim_end_matches(&checked_ty.to_string()).len();
                 span.with_lo(span.lo() + BytePos(len as u32))
             },
-            if expr.precedence() < ExprPrecedence::Unambiguous {
+            if self.precedence(expr) < ExprPrecedence::Unambiguous {
                 // Readd `)`
                 format!("{expected_ty})")
             } else {
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 0238d6a3947..02d1ebdb31a 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -18,6 +18,7 @@ use rustc_hir::def_id::{LOCAL_CRATE, StableCrateId, StableCrateIdMap};
 use rustc_hir::definitions::Definitions;
 use rustc_incremental::setup_dep_graph;
 use rustc_lint::{BufferedEarlyLint, EarlyCheckNode, LintStore, unerased_lint_store};
+use rustc_metadata::EncodedMetadata;
 use rustc_metadata::creader::CStore;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepsType;
@@ -1174,7 +1175,7 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) {
 pub(crate) fn start_codegen<'tcx>(
     codegen_backend: &dyn CodegenBackend,
     tcx: TyCtxt<'tcx>,
-) -> Box<dyn Any> {
+) -> (Box<dyn Any>, EncodedMetadata) {
     // Hook for tests.
     if let Some((def_id, _)) = tcx.entry_fn(())
         && tcx.has_attr(def_id, sym::rustc_delayed_bug_from_inside_query)
@@ -1197,11 +1198,9 @@ pub(crate) fn start_codegen<'tcx>(
 
     info!("Pre-codegen\n{:?}", tcx.debug_stats());
 
-    let (metadata, need_metadata_module) = rustc_metadata::fs::encode_and_write_metadata(tcx);
+    let metadata = rustc_metadata::fs::encode_and_write_metadata(tcx);
 
-    let codegen = tcx.sess.time("codegen_crate", move || {
-        codegen_backend.codegen_crate(tcx, metadata, need_metadata_module)
-    });
+    let codegen = tcx.sess.time("codegen_crate", move || codegen_backend.codegen_crate(tcx));
 
     info!("Post-codegen\n{:?}", tcx.debug_stats());
 
@@ -1211,7 +1210,7 @@ pub(crate) fn start_codegen<'tcx>(
         tcx.sess.code_stats.print_type_sizes();
     }
 
-    codegen
+    (codegen, metadata)
 }
 
 /// Compute and validate the crate name.
diff --git a/compiler/rustc_interface/src/queries.rs b/compiler/rustc_interface/src/queries.rs
index c8914c9be9c..9a474b910f6 100644
--- a/compiler/rustc_interface/src/queries.rs
+++ b/compiler/rustc_interface/src/queries.rs
@@ -5,6 +5,7 @@ use rustc_codegen_ssa::CodegenResults;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::svh::Svh;
 use rustc_hir::def_id::LOCAL_CRATE;
+use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
@@ -18,6 +19,7 @@ pub struct Linker {
     output_filenames: Arc<OutputFilenames>,
     // Only present when incr. comp. is enabled.
     crate_hash: Option<Svh>,
+    metadata: EncodedMetadata,
     ongoing_codegen: Box<dyn Any>,
 }
 
@@ -26,7 +28,7 @@ impl Linker {
         tcx: TyCtxt<'_>,
         codegen_backend: &dyn CodegenBackend,
     ) -> Linker {
-        let ongoing_codegen = passes::start_codegen(codegen_backend, tcx);
+        let (ongoing_codegen, metadata) = passes::start_codegen(codegen_backend, tcx);
 
         Linker {
             dep_graph: tcx.dep_graph.clone(),
@@ -36,6 +38,7 @@ impl Linker {
             } else {
                 None
             },
+            metadata,
             ongoing_codegen,
         }
     }
@@ -75,6 +78,7 @@ impl Linker {
                 sess,
                 &rlink_file,
                 &codegen_results,
+                &self.metadata,
                 &*self.output_filenames,
             )
             .unwrap_or_else(|error| {
@@ -84,6 +88,6 @@ impl Linker {
         }
 
         let _timer = sess.prof.verbose_generic_activity("link_crate");
-        codegen_backend.link(sess, codegen_results, &self.output_filenames)
+        codegen_backend.link(sess, codegen_results, self.metadata, &self.output_filenames)
     }
 }
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 5419d688caa..82823581c12 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -27,7 +27,7 @@ use rustc_span::source_map::{RealFileLoader, SourceMapInputs};
 use rustc_span::{FileName, SourceFileHashAlgorithm, sym};
 use rustc_target::spec::{
     CodeModel, FramePointer, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy,
-    RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel, WasmCAbi,
+    RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel,
 };
 
 use crate::interface::{initialize_checked_jobserver, parse_cfg};
@@ -882,7 +882,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(verify_llvm_ir, true);
     tracked!(virtual_function_elimination, true);
     tracked!(wasi_exec_model, Some(WasiExecModel::Reactor));
-    tracked!(wasm_c_abi, WasmCAbi::Spec);
     // tidy-alphabetical-end
 
     macro_rules! tracked_no_crate_hash {
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index 5679d4566dc..b6bf45dfbcf 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -7,6 +7,7 @@ use std::cell::Cell;
 use std::slice;
 
 use rustc_ast::BindingMode;
+use rustc_ast::util::parser::ExprPrecedence;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync;
 use rustc_data_structures::unord::UnordMap;
@@ -850,6 +851,20 @@ impl<'tcx> LateContext<'tcx> {
             })
     }
 
+    /// Returns the effective precedence of an expression for the purpose of
+    /// rendering diagnostic. This is not the same as the precedence that would
+    /// be used for pretty-printing HIR by rustc_hir_pretty.
+    pub fn precedence(&self, expr: &hir::Expr<'_>) -> ExprPrecedence {
+        let for_each_attr = |id: hir::HirId, callback: &mut dyn FnMut(&hir::Attribute)| {
+            for attr in self.tcx.hir_attrs(id) {
+                if attr.span().desugaring_kind().is_none() {
+                    callback(attr);
+                }
+            }
+        };
+        expr.precedence(&for_each_attr)
+    }
+
     /// If the given expression is a local binding, find the initializer expression.
     /// If that initializer expression is another local binding, find its initializer again.
     ///
diff --git a/compiler/rustc_lint/src/dangling.rs b/compiler/rustc_lint/src/dangling.rs
index 91c7922638d..c737919db9c 100644
--- a/compiler/rustc_lint/src/dangling.rs
+++ b/compiler/rustc_lint/src/dangling.rs
@@ -1,4 +1,5 @@
 use rustc_ast::visit::{visit_opt, walk_list};
+use rustc_attr_data_structures::{AttributeKind, find_attr};
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{FnKind, Visitor, walk_expr};
 use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, LangItem};
@@ -133,7 +134,7 @@ fn lint_expr(cx: &LateContext<'_>, expr: &Expr<'_>) {
         && let ty = cx.typeck_results().expr_ty(receiver)
         && owns_allocation(cx.tcx, ty)
         && let Some(fn_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
-        && cx.tcx.has_attr(fn_id, sym::rustc_as_ptr)
+        && find_attr!(cx.tcx.get_all_attrs(fn_id), AttributeKind::AsPtr(_))
     {
         // FIXME: use `emit_node_lint` when `#[primary_span]` is added.
         cx.tcx.emit_node_span_lint(
diff --git a/compiler/rustc_lint/src/early.rs b/compiler/rustc_lint/src/early.rs
index 12666d383f9..48e3bbb79fa 100644
--- a/compiler/rustc_lint/src/early.rs
+++ b/compiler/rustc_lint/src/early.rs
@@ -33,10 +33,8 @@ pub struct EarlyContextAndPass<'ecx, 'tcx, T: EarlyLintPass> {
 }
 
 impl<'ecx, 'tcx, T: EarlyLintPass> EarlyContextAndPass<'ecx, 'tcx, T> {
-    // This always-inlined function is for the hot call site.
-    #[inline(always)]
     #[allow(rustc::diagnostic_outside_of_impl)]
-    fn inlined_check_id(&mut self, id: ast::NodeId) {
+    fn check_id(&mut self, id: ast::NodeId) {
         for early_lint in self.context.buffered.take(id) {
             let BufferedEarlyLint { span, node_id: _, lint_id, diagnostic } = early_lint;
             self.context.opt_span_lint(lint_id.lint, span, |diag| {
@@ -45,11 +43,6 @@ impl<'ecx, 'tcx, T: EarlyLintPass> EarlyContextAndPass<'ecx, 'tcx, T> {
         }
     }
 
-    // This non-inlined function is for the cold call sites.
-    fn check_id(&mut self, id: ast::NodeId) {
-        self.inlined_check_id(id)
-    }
-
     /// Merge the lints specified by any lint attributes into the
     /// current lint context, call the provided function, then reset the
     /// lints in effect to their previous state.
@@ -61,7 +54,6 @@ impl<'ecx, 'tcx, T: EarlyLintPass> EarlyContextAndPass<'ecx, 'tcx, T> {
         debug!(?id);
         let push = self.context.builder.push(attrs, is_crate_node, None);
 
-        self.inlined_check_id(id);
         debug!("early context: enter_attrs({:?})", attrs);
         lint_callback!(self, check_attributes, attrs);
         ensure_sufficient_stack(|| f(self));
@@ -136,12 +128,8 @@ impl<'ast, 'ecx, 'tcx, T: EarlyLintPass> ast_visit::Visitor<'ast>
         // the AST struct that they wrap (e.g. an item)
         self.with_lint_attrs(s.id, s.attrs(), |cx| {
             lint_callback!(cx, check_stmt, s);
+            ast_visit::walk_stmt(cx, s);
         });
-        // The visitor for the AST struct wrapped
-        // by the statement (e.g. `Item`) will call
-        // `with_lint_attrs`, so do this walk
-        // outside of the above `with_lint_attrs` call
-        ast_visit::walk_stmt(self, s);
     }
 
     fn visit_fn(&mut self, fk: ast_visit::FnKind<'ast>, span: Span, id: ast::NodeId) {
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index e84cdb581b5..9a1490d3eea 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -623,6 +623,7 @@ fn register_builtins(store: &mut LintStore) {
         "converted into hard error, \
          see <https://github.com/rust-lang/rust/issues/40107> for more information",
     );
+    store.register_removed("wasm_c_abi", "the wasm C ABI has been fixed");
 }
 
 fn register_internals(store: &mut LintStore) {
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 295dd82fead..b0ea9689e50 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -140,7 +140,6 @@ declare_lint_pass! {
         UNUSED_VARIABLES,
         USELESS_DEPRECATED,
         WARNINGS,
-        WASM_C_ABI,
         // tidy-alphabetical-end
     ]
 }
@@ -4100,6 +4099,7 @@ declare_lint! {
     @future_incompatible = FutureIncompatibleInfo {
         reason: FutureIncompatibilityReason::EditionAndFutureReleaseSemanticsChange(Edition::Edition2024),
         reference: "<https://doc.rust-lang.org/nightly/edition-guide/rust-2024/never-type-fallback.html>",
+        report_in_deps: true,
     };
     @edition Edition2024 => Deny;
     report_in_external_macro
@@ -4154,6 +4154,7 @@ declare_lint! {
     @future_incompatible = FutureIncompatibleInfo {
         reason: FutureIncompatibilityReason::EditionAndFutureReleaseError(Edition::Edition2024),
         reference: "<https://doc.rust-lang.org/nightly/edition-guide/rust-2024/never-type-fallback.html>",
+        report_in_deps: true,
     };
     report_in_external_macro
 }
@@ -4981,50 +4982,6 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `wasm_c_abi` lint detects usage of the `extern "C"` ABI of wasm that is affected
-    /// by a planned ABI change that has the goal of aligning Rust with the standard C ABI
-    /// of this target.
-    ///
-    /// ### Example
-    ///
-    /// ```rust,ignore (needs wasm32-unknown-unknown)
-    /// #[repr(C)]
-    /// struct MyType(i32, i32);
-    ///
-    /// extern "C" my_fun(x: MyType) {}
-    /// ```
-    ///
-    /// This will produce:
-    ///
-    /// ```text
-    /// error: this function function definition is affected by the wasm ABI transition: it passes an argument of non-scalar type `MyType`
-    ///   --> $DIR/wasm_c_abi_transition.rs:17:1
-    ///    |
-    ///    | pub extern "C" fn my_fun(_x: MyType) {}
-    ///    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    ///    |
-    ///    = 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 #138762 <https://github.com/rust-lang/rust/issues/138762>
-    ///    = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target
-    /// ```
-    ///
-    /// ### Explanation
-    ///
-    /// Rust has historically implemented a non-spec-compliant C ABI on wasm32-unknown-unknown. This
-    /// has caused incompatibilities with other compilers and Wasm targets. In a future version
-    /// of Rust, this will be fixed, and therefore code relying on the non-spec-compliant C ABI will
-    /// stop functioning.
-    pub WASM_C_ABI,
-    Warn,
-    "detects code relying on rustc's non-spec-compliant wasm C ABI",
-    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseError,
-        reference: "issue #138762 <https://github.com/rust-lang/rust/issues/138762>",
-        report_in_deps: true,
-    };
-}
-
-declare_lint! {
     /// The `aarch64_softfloat_neon` lint detects usage of `#[target_feature(enable = "neon")]` on
     /// softfloat aarch64 targets. Enabling this target feature causes LLVM to alter the ABI of
     /// function calls, making this attribute unsound to use.
diff --git a/compiler/rustc_metadata/src/fs.rs b/compiler/rustc_metadata/src/fs.rs
index e57534b847e..1eaad26ff8e 100644
--- a/compiler/rustc_metadata/src/fs.rs
+++ b/compiler/rustc_metadata/src/fs.rs
@@ -4,9 +4,9 @@ use std::{fs, io};
 use rustc_data_structures::temp_dir::MaybeTempDir;
 use rustc_fs_util::TempDirBuilder;
 use rustc_middle::ty::TyCtxt;
+use rustc_session::Session;
 use rustc_session::config::{CrateType, OutFileName, OutputType};
 use rustc_session::output::filename_for_metadata;
-use rustc_session::{MetadataKind, Session};
 
 use crate::errors::{
     BinaryOutputToTty, FailedCopyToStdout, FailedCreateEncodedMetadata, FailedCreateFile,
@@ -22,13 +22,8 @@ pub const METADATA_FILENAME: &str = "lib.rmeta";
 /// building an `.rlib` (stomping over one another), or writing an `.rmeta` into a
 /// directory being searched for `extern crate` (observing an incomplete file).
 /// The returned path is the temporary file containing the complete metadata.
-pub fn emit_wrapper_file(
-    sess: &Session,
-    data: &[u8],
-    tmpdir: &MaybeTempDir,
-    name: &str,
-) -> PathBuf {
-    let out_filename = tmpdir.as_ref().join(name);
+pub fn emit_wrapper_file(sess: &Session, data: &[u8], tmpdir: &Path, name: &str) -> PathBuf {
+    let out_filename = tmpdir.join(name);
     let result = fs::write(&out_filename, data);
 
     if let Err(err) = result {
@@ -38,7 +33,7 @@ pub fn emit_wrapper_file(
     out_filename
 }
 
-pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> (EncodedMetadata, bool) {
+pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
     let out_filename = filename_for_metadata(tcx.sess, tcx.output_filenames(()));
     // To avoid races with another rustc process scanning the output directory,
     // we need to write the file somewhere else and atomically move it to its
@@ -59,25 +54,20 @@ pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> (EncodedMetadata, bool) {
         None
     };
 
-    // Always create a file at `metadata_filename`, even if we have nothing to write to it.
-    // This simplifies the creation of the output `out_filename` when requested.
-    let metadata_kind = tcx.metadata_kind();
-    match metadata_kind {
-        MetadataKind::None => {
-            std::fs::File::create(&metadata_filename).unwrap_or_else(|err| {
-                tcx.dcx().emit_fatal(FailedCreateFile { filename: &metadata_filename, err });
+    if tcx.needs_metadata() {
+        encode_metadata(tcx, &metadata_filename, metadata_stub_filename.as_deref());
+    } else {
+        // Always create a file at `metadata_filename`, even if we have nothing to write to it.
+        // This simplifies the creation of the output `out_filename` when requested.
+        std::fs::File::create(&metadata_filename).unwrap_or_else(|err| {
+            tcx.dcx().emit_fatal(FailedCreateFile { filename: &metadata_filename, err });
+        });
+        if let Some(metadata_stub_filename) = &metadata_stub_filename {
+            std::fs::File::create(metadata_stub_filename).unwrap_or_else(|err| {
+                tcx.dcx().emit_fatal(FailedCreateFile { filename: &metadata_stub_filename, err });
             });
-            if let Some(metadata_stub_filename) = &metadata_stub_filename {
-                std::fs::File::create(metadata_stub_filename).unwrap_or_else(|err| {
-                    tcx.dcx()
-                        .emit_fatal(FailedCreateFile { filename: &metadata_stub_filename, err });
-                });
-            }
-        }
-        MetadataKind::Uncompressed | MetadataKind::Compressed => {
-            encode_metadata(tcx, &metadata_filename, metadata_stub_filename.as_deref())
         }
-    };
+    }
 
     let _prof_timer = tcx.sess.prof.generic_activity("write_crate_metadata");
 
@@ -118,9 +108,7 @@ pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> (EncodedMetadata, bool) {
                 tcx.dcx().emit_fatal(FailedCreateEncodedMetadata { err });
             });
 
-    let need_metadata_module = metadata_kind == MetadataKind::Compressed;
-
-    (metadata, need_metadata_module)
+    metadata
 }
 
 #[cfg(not(target_os = "linux"))]
diff --git a/compiler/rustc_middle/src/hir/map.rs b/compiler/rustc_middle/src/hir/map.rs
index 3de97c8c0d9..e5e1ae508ed 100644
--- a/compiler/rustc_middle/src/hir/map.rs
+++ b/compiler/rustc_middle/src/hir/map.rs
@@ -1233,6 +1233,7 @@ pub(super) fn hir_module_items(tcx: TyCtxt<'_>, module_id: LocalModDefId) -> Mod
         body_owners: body_owners.into_boxed_slice(),
         opaques: opaques.into_boxed_slice(),
         nested_bodies: nested_bodies.into_boxed_slice(),
+        delayed_lint_items: Box::new([]),
     }
 }
 
@@ -1254,6 +1255,7 @@ pub(crate) fn hir_crate_items(tcx: TyCtxt<'_>, _: ()) -> ModuleItems {
         body_owners,
         opaques,
         nested_bodies,
+        delayed_lint_items,
         ..
     } = collector;
 
@@ -1266,6 +1268,7 @@ pub(crate) fn hir_crate_items(tcx: TyCtxt<'_>, _: ()) -> ModuleItems {
         body_owners: body_owners.into_boxed_slice(),
         opaques: opaques.into_boxed_slice(),
         nested_bodies: nested_bodies.into_boxed_slice(),
+        delayed_lint_items: delayed_lint_items.into_boxed_slice(),
     }
 }
 
@@ -1282,6 +1285,7 @@ struct ItemCollector<'tcx> {
     body_owners: Vec<LocalDefId>,
     opaques: Vec<LocalDefId>,
     nested_bodies: Vec<LocalDefId>,
+    delayed_lint_items: Vec<OwnerId>,
 }
 
 impl<'tcx> ItemCollector<'tcx> {
@@ -1297,6 +1301,7 @@ impl<'tcx> ItemCollector<'tcx> {
             body_owners: Vec::default(),
             opaques: Vec::default(),
             nested_bodies: Vec::default(),
+            delayed_lint_items: Vec::default(),
         }
     }
 }
@@ -1314,6 +1319,9 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.items.push(item.item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.item_id().owner_id);
+        }
 
         // Items that are modules are handled here instead of in visit_mod.
         if let ItemKind::Mod(_, module) = &item.kind {
@@ -1329,6 +1337,9 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
 
     fn visit_foreign_item(&mut self, item: &'hir ForeignItem<'hir>) {
         self.foreign_items.push(item.foreign_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.foreign_item_id().owner_id);
+        }
         intravisit::walk_foreign_item(self, item)
     }
 
@@ -1362,6 +1373,10 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.trait_items.push(item.trait_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.trait_item_id().owner_id);
+        }
+
         intravisit::walk_trait_item(self, item)
     }
 
@@ -1371,6 +1386,10 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         }
 
         self.impl_items.push(item.impl_item_id());
+        if self.crate_collector && item.has_delayed_lints {
+            self.delayed_lint_items.push(item.impl_item_id().owner_id);
+        }
+
         intravisit::walk_impl_item(self, item)
     }
 }
diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index cb4760c18de..9f79ed4b5a5 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -32,6 +32,8 @@ pub struct ModuleItems {
     opaques: Box<[LocalDefId]>,
     body_owners: Box<[LocalDefId]>,
     nested_bodies: Box<[LocalDefId]>,
+    // only filled with hir_crate_items, not with hir_module_items
+    delayed_lint_items: Box<[OwnerId]>,
 }
 
 impl ModuleItems {
@@ -49,6 +51,10 @@ impl ModuleItems {
         self.trait_items.iter().copied()
     }
 
+    pub fn delayed_lint_items(&self) -> impl Iterator<Item = OwnerId> {
+        self.delayed_lint_items.iter().copied()
+    }
+
     /// Returns all items that are associated with some `impl` block (both inherent and trait impl
     /// blocks).
     pub fn impl_items(&self) -> impl Iterator<Item = ImplItemId> {
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 15e8c1ef3cc..63312eff490 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1,8 +1,64 @@
-//! Defines the various compiler queries.
 //!
-//! For more information on the query system, see
-//! ["Queries: demand-driven compilation"](https://rustc-dev-guide.rust-lang.org/query.html).
-//! This chapter includes instructions for adding new queries.
+//! # The rustc Query System: Query Definitions and Modifiers
+//!
+//! The core processes in rustc are shipped as queries. Each query is a demand-driven function from some key to a value.
+//! The execution result of the function is cached and directly read during the next request, thereby improving compilation efficiency.
+//! Some results are saved locally and directly read during the next compilation, which are core of incremental compilation.
+//!
+//! ## How to Read This Module
+//!
+//! Each `query` block in this file defines a single query, specifying its key and value types, along with various modifiers.
+//! These query definitions are processed by the [`rustc_macros`], which expands them into the necessary boilerplate code
+//! for the query system—including the [`Providers`] struct (a function table for all query implementations, where each field is
+//! a function pointer to the actual provider), caching, and dependency graph integration.
+//! **Note:** The `Providers` struct is not a Rust trait, but a struct generated by the `rustc_macros` to hold all provider functions.
+//! The `rustc_macros` also supports a set of **query modifiers** (see below) that control the behavior of each query.
+//!
+//! The actual provider functions are implemented in various modules and registered into the `Providers` struct
+//! during compiler initialization (see [`rustc_interface::passes::DEFAULT_QUERY_PROVIDERS`]).
+//!
+//! [`rustc_macros`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_macros/index.html
+//! [`rustc_interface::passes::DEFAULT_QUERY_PROVIDERS`]: ../../rustc_interface/passes/static.DEFAULT_QUERY_PROVIDERS.html
+//!
+//! ## Query Modifiers
+//!
+//! Query modifiers are special flags that alter the behavior of a query. They are parsed and processed by the `rustc_macros`
+//! The main modifiers are:
+//!
+//! - `desc { ... }`: Sets the human-readable description for diagnostics and profiling. Required for every query.
+//! - `arena_cache`: Use an arena for in-memory caching of the query result.
+//! - `cache_on_disk_if { ... }`: Cache the query result to disk if the provided block evaluates to true.
+//! - `fatal_cycle`: If a dependency cycle is detected, abort compilation with a fatal error.
+//! - `cycle_delay_bug`: If a dependency cycle is detected, emit a delayed bug instead of aborting immediately.
+//! - `cycle_stash`: If a dependency cycle is detected, stash the error for later handling.
+//! - `no_hash`: Do not hash the query result for incremental compilation; just mark as dirty if recomputed.
+//! - `anon`: Make the query anonymous in the dependency graph (no dep node is created).
+//! - `eval_always`: Always evaluate the query, ignoring its dependencies and cached results.
+//! - `depth_limit`: Impose a recursion depth limit on the query to prevent stack overflows.
+//! - `separate_provide_extern`: Use separate provider functions for local and external crates.
+//! - `feedable`: Allow the query result to be set from another query ("fed" externally).
+//! - `return_result_from_ensure_ok`: When called via `tcx.ensure_ok()`, return `Result<(), ErrorGuaranteed>` instead of `()`.
+//!   If the query needs to be executed and returns an error, the error is returned to the caller.
+//!   Only valid for queries returning `Result<_, ErrorGuaranteed>`.
+//!
+//! For the up-to-date list, see the `QueryModifiers` struct in
+//! [`rustc_macros/src/query.rs`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_macros/src/query.rs)
+//! and for more details in incremental compilation, see the
+//! [Query modifiers in incremental compilation](https://rustc-dev-guide.rust-lang.org/queries/incremental-compilation-in-detail.html#query-modifiers) section of the rustc-dev-guide.
+//!
+//! ## Query Expansion and Code Generation
+//!
+//! The [`rustc_macros::rustc_queries`] macro expands each query definition into:
+//! - A method on [`TyCtxt`] (and [`TyCtxtAt`]) for invoking the query.
+//! - Provider traits and structs for supplying the query's value.
+//! - Caching and dependency graph integration.
+//! - Support for incremental compilation, disk caching, and arena allocation as controlled by the modifiers.
+//!
+//! [`rustc_macros::rustc_queries`]: ../../rustc_macros/macro.rustc_queries.html
+//!
+//! The macro-based approach allows the query system to be highly flexible and maintainable, while minimizing boilerplate.
+//!
+//! For more details, see the [rustc-dev-guide](https://rustc-dev-guide.rust-lang.org/query.html).
 
 #![allow(unused_parens)]
 
diff --git a/compiler/rustc_middle/src/traits/solve.rs b/compiler/rustc_middle/src/traits/solve.rs
index 145561b76c4..ef5223de0e8 100644
--- a/compiler/rustc_middle/src/traits/solve.rs
+++ b/compiler/rustc_middle/src/traits/solve.rs
@@ -49,6 +49,13 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
+        // Perf testing has found that this check is slightly faster than
+        // folding and re-interning an empty `ExternalConstraintsData`.
+        // See: <https://github.com/rust-lang/rust/pull/142430>.
+        if self.is_empty() {
+            return Ok(self);
+        }
+
         Ok(FallibleTypeFolder::cx(folder).mk_external_constraints(ExternalConstraintsData {
             region_constraints: self.region_constraints.clone().try_fold_with(folder)?,
             opaque_types: self
@@ -64,6 +71,13 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
     }
 
     fn fold_with<F: TypeFolder<TyCtxt<'tcx>>>(self, folder: &mut F) -> Self {
+        // Perf testing has found that this check is slightly faster than
+        // folding and re-interning an empty `ExternalConstraintsData`.
+        // See: <https://github.com/rust-lang/rust/pull/142430>.
+        if self.is_empty() {
+            return self;
+        }
+
         TypeFolder::cx(folder).mk_external_constraints(ExternalConstraintsData {
             region_constraints: self.region_constraints.clone().fold_with(folder),
             opaque_types: self.opaque_types.iter().map(|opaque| opaque.fold_with(folder)).collect(),
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index b4d8b2e7176..fe4dd8d080b 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -47,7 +47,7 @@ use rustc_serialize::opaque::{FileEncodeResult, FileEncoder};
 use rustc_session::config::CrateType;
 use rustc_session::cstore::{CrateStoreDyn, Untracked};
 use rustc_session::lint::Lint;
-use rustc_session::{Limit, MetadataKind, Session};
+use rustc_session::{Limit, Session};
 use rustc_span::def_id::{CRATE_DEF_ID, DefPathHash, StableCrateId};
 use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
 use rustc_type_ir::TyKind::*;
@@ -1858,23 +1858,14 @@ impl<'tcx> TyCtxt<'tcx> {
         &self.crate_types
     }
 
-    pub fn metadata_kind(self) -> MetadataKind {
-        self.crate_types()
-            .iter()
-            .map(|ty| match *ty {
-                CrateType::Executable
-                | CrateType::Staticlib
-                | CrateType::Cdylib
-                | CrateType::Sdylib => MetadataKind::None,
-                CrateType::Rlib => MetadataKind::Uncompressed,
-                CrateType::Dylib | CrateType::ProcMacro => MetadataKind::Compressed,
-            })
-            .max()
-            .unwrap_or(MetadataKind::None)
-    }
-
     pub fn needs_metadata(self) -> bool {
-        self.metadata_kind() != MetadataKind::None
+        self.crate_types().iter().any(|ty| match *ty {
+            CrateType::Executable
+            | CrateType::Staticlib
+            | CrateType::Cdylib
+            | CrateType::Sdylib => false,
+            CrateType::Rlib | CrateType::Dylib | CrateType::ProcMacro => true,
+        })
     }
 
     pub fn needs_crate_hash(self) -> bool {
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 9bce2845680..13c281a6182 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -16,9 +16,7 @@ use rustc_macros::{HashStable, TyDecodable, TyEncodable, extension};
 use rustc_session::config::OptLevel;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 use rustc_target::callconv::FnAbi;
-use rustc_target::spec::{
-    HasTargetSpec, HasWasmCAbiOpt, HasX86AbiOpt, PanicStrategy, Target, WasmCAbi, X86Abi,
-};
+use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, PanicStrategy, Target, X86Abi};
 use tracing::debug;
 use {rustc_abi as abi, rustc_hir as hir};
 
@@ -565,12 +563,6 @@ impl<'tcx> HasTargetSpec for TyCtxt<'tcx> {
     }
 }
 
-impl<'tcx> HasWasmCAbiOpt for TyCtxt<'tcx> {
-    fn wasm_c_abi_opt(&self) -> WasmCAbi {
-        self.sess.opts.unstable_opts.wasm_c_abi
-    }
-}
-
 impl<'tcx> HasX86AbiOpt for TyCtxt<'tcx> {
     fn x86_abi_opt(&self) -> X86Abi {
         X86Abi {
@@ -625,12 +617,6 @@ impl<'tcx> HasTargetSpec for LayoutCx<'tcx> {
     }
 }
 
-impl<'tcx> HasWasmCAbiOpt for LayoutCx<'tcx> {
-    fn wasm_c_abi_opt(&self) -> WasmCAbi {
-        self.calc.cx.wasm_c_abi_opt()
-    }
-}
-
 impl<'tcx> HasX86AbiOpt for LayoutCx<'tcx> {
     fn x86_abi_opt(&self) -> X86Abi {
         self.calc.cx.x86_abi_opt()
diff --git a/compiler/rustc_mir_transform/src/coroutine/drop.rs b/compiler/rustc_mir_transform/src/coroutine/drop.rs
index 6021e795d21..dc68629ec0d 100644
--- a/compiler/rustc_mir_transform/src/coroutine/drop.rs
+++ b/compiler/rustc_mir_transform/src/coroutine/drop.rs
@@ -132,6 +132,7 @@ fn build_poll_switch<'tcx>(
     body: &mut Body<'tcx>,
     poll_enum: Ty<'tcx>,
     poll_unit_place: &Place<'tcx>,
+    fut_pin_place: &Place<'tcx>,
     ready_block: BasicBlock,
     yield_block: BasicBlock,
 ) -> BasicBlock {
@@ -162,9 +163,11 @@ fn build_poll_switch<'tcx>(
             Rvalue::Discriminant(*poll_unit_place),
         ))),
     };
+    let storage_dead =
+        Statement { source_info, kind: StatementKind::StorageDead(fut_pin_place.local) };
     let unreachable_block = insert_term_block(body, TerminatorKind::Unreachable);
     body.basic_blocks_mut().push(BasicBlockData {
-        statements: [discr_assign].to_vec(),
+        statements: [storage_dead, discr_assign].to_vec(),
         terminator: Some(Terminator {
             source_info,
             kind: TerminatorKind::SwitchInt {
@@ -332,10 +335,17 @@ pub(super) fn expand_async_drops<'tcx>(
             kind: StatementKind::Assign(Box::new((context_ref_place, arg))),
         });
         let yield_block = insert_term_block(body, TerminatorKind::Unreachable); // `kind` replaced later to yield
-        let switch_block =
-            build_poll_switch(tcx, body, poll_enum, &poll_unit_place, target, yield_block);
         let (pin_bb, fut_pin_place) =
             build_pin_fut(tcx, body, fut_place.clone(), UnwindAction::Continue);
+        let switch_block = build_poll_switch(
+            tcx,
+            body,
+            poll_enum,
+            &poll_unit_place,
+            &fut_pin_place,
+            target,
+            yield_block,
+        );
         let call_bb = build_poll_call(
             tcx,
             body,
@@ -357,16 +367,17 @@ pub(super) fn expand_async_drops<'tcx>(
                 body.local_decls.push(LocalDecl::new(context_mut_ref, source_info.span)),
             );
             let drop_yield_block = insert_term_block(body, TerminatorKind::Unreachable); // `kind` replaced later to yield
+            let (pin_bb2, fut_pin_place2) =
+                build_pin_fut(tcx, body, fut_place, UnwindAction::Continue);
             let drop_switch_block = build_poll_switch(
                 tcx,
                 body,
                 poll_enum,
                 &poll_unit_place,
+                &fut_pin_place2,
                 drop.unwrap(),
                 drop_yield_block,
             );
-            let (pin_bb2, fut_pin_place2) =
-                build_pin_fut(tcx, body, fut_place, UnwindAction::Continue);
             let drop_call_bb = build_poll_call(
                 tcx,
                 body,
diff --git a/compiler/rustc_mir_transform/src/elaborate_drop.rs b/compiler/rustc_mir_transform/src/elaborate_drop.rs
index 3a5e2620b14..c9bc52c6c7e 100644
--- a/compiler/rustc_mir_transform/src/elaborate_drop.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_drop.rs
@@ -390,6 +390,20 @@ where
             Location { block: self.succ, statement_index: 0 },
             StatementKind::StorageDead(fut.local),
         );
+        // StorageDead(fut) in unwind block (at the begin)
+        if let Unwind::To(block) = unwind {
+            self.elaborator.patch().add_statement(
+                Location { block, statement_index: 0 },
+                StatementKind::StorageDead(fut.local),
+            );
+        }
+        // StorageDead(fut) in dropline block (at the begin)
+        if let Some(block) = dropline {
+            self.elaborator.patch().add_statement(
+                Location { block, statement_index: 0 },
+                StatementKind::StorageDead(fut.local),
+            );
+        }
 
         // #1:pin_obj_bb >>> call Pin<ObjTy>::new_unchecked(&mut obj)
         self.elaborator.patch().patch_terminator(
diff --git a/compiler/rustc_monomorphize/messages.ftl b/compiler/rustc_monomorphize/messages.ftl
index 35bedf4318f..2bd19e81b01 100644
--- a/compiler/rustc_monomorphize/messages.ftl
+++ b/compiler/rustc_monomorphize/messages.ftl
@@ -60,11 +60,4 @@ monomorphize_start_not_found = using `fn main` requires the standard library
 
 monomorphize_symbol_already_defined = symbol `{$symbol}` is already defined
 
-monomorphize_wasm_c_abi_transition =
-    this function {$is_call ->
-      [true] call
-      *[false] definition
-    } involves an argument of type `{$ty}` which is affected by the wasm ABI transition
-    .help = the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target
-
 monomorphize_written_to_path = the full type name has been written to '{$path}'
diff --git a/compiler/rustc_monomorphize/src/errors.rs b/compiler/rustc_monomorphize/src/errors.rs
index acf77b5916e..938c427b56c 100644
--- a/compiler/rustc_monomorphize/src/errors.rs
+++ b/compiler/rustc_monomorphize/src/errors.rs
@@ -100,12 +100,3 @@ pub(crate) struct AbiRequiredTargetFeature<'a> {
     /// Whether this is a problem at a call site or at a declaration.
     pub is_call: bool,
 }
-
-#[derive(LintDiagnostic)]
-#[diag(monomorphize_wasm_c_abi_transition)]
-#[help]
-pub(crate) struct WasmCAbiTransition<'a> {
-    pub ty: Ty<'a>,
-    /// Whether this is a problem at a call site or at a declaration.
-    pub is_call: bool,
-}
diff --git a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
index 8dbbb4d1713..b8c001d357e 100644
--- a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
+++ b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
@@ -3,13 +3,10 @@
 use rustc_abi::{BackendRepr, CanonAbi, RegKind, X86Call};
 use rustc_hir::{CRATE_HIR_ID, HirId};
 use rustc_middle::mir::{self, Location, traversal};
-use rustc_middle::ty::layout::LayoutCx;
-use rustc_middle::ty::{self, Instance, InstanceKind, Ty, TyCtxt, TypingEnv};
-use rustc_session::lint::builtin::WASM_C_ABI;
+use rustc_middle::ty::{self, Instance, InstanceKind, Ty, TyCtxt};
 use rustc_span::def_id::DefId;
 use rustc_span::{DUMMY_SP, Span, Symbol, sym};
-use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
-use rustc_target::spec::{HasWasmCAbiOpt, WasmCAbi};
+use rustc_target::callconv::{FnAbi, PassMode};
 
 use crate::errors;
 
@@ -81,73 +78,6 @@ fn do_check_simd_vector_abi<'tcx>(
     }
 }
 
-/// Determines whether the given argument is passed the same way on the old and new wasm ABIs.
-fn wasm_abi_safe<'tcx>(tcx: TyCtxt<'tcx>, arg: &ArgAbi<'tcx, Ty<'tcx>>) -> bool {
-    if matches!(arg.layout.backend_repr, BackendRepr::Scalar(_)) {
-        return true;
-    }
-
-    // Both the old and the new ABIs treat vector types like `v128` the same
-    // way.
-    if uses_vector_registers(&arg.mode, &arg.layout.backend_repr) {
-        return true;
-    }
-
-    // This matches `unwrap_trivial_aggregate` in the wasm ABI logic.
-    if arg.layout.is_aggregate() {
-        let cx = LayoutCx::new(tcx, TypingEnv::fully_monomorphized());
-        if let Some(unit) = arg.layout.homogeneous_aggregate(&cx).ok().and_then(|ha| ha.unit()) {
-            let size = arg.layout.size;
-            // Ensure there's just a single `unit` element in `arg`.
-            if unit.size == size {
-                return true;
-            }
-        }
-    }
-
-    // Zero-sized types are dropped in both ABIs, so they're safe
-    if arg.layout.is_zst() {
-        return true;
-    }
-
-    false
-}
-
-/// Warns against usage of `extern "C"` on wasm32-unknown-unknown that is affected by the
-/// ABI transition.
-fn do_check_wasm_abi<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    abi: &FnAbi<'tcx, Ty<'tcx>>,
-    is_call: bool,
-    loc: impl Fn() -> (Span, HirId),
-) {
-    // Only proceed for `extern "C" fn` on wasm32-unknown-unknown (same check as what
-    // `adjust_for_foreign_abi` uses to call `compute_wasm_abi_info`), and only proceed if
-    // `wasm_c_abi_opt` indicates we should emit the lint.
-    if !(tcx.sess.target.arch == "wasm32"
-        && tcx.sess.target.os == "unknown"
-        && tcx.wasm_c_abi_opt() == WasmCAbi::Legacy { with_lint: true }
-        && abi.conv == CanonAbi::C)
-    {
-        return;
-    }
-    // Warn against all types whose ABI will change. Return values are not affected by this change.
-    for arg_abi in abi.args.iter() {
-        if wasm_abi_safe(tcx, arg_abi) {
-            continue;
-        }
-        let (span, hir_id) = loc();
-        tcx.emit_node_span_lint(
-            WASM_C_ABI,
-            hir_id,
-            span,
-            errors::WasmCAbiTransition { ty: arg_abi.layout.ty, is_call },
-        );
-        // Let's only warn once per function.
-        break;
-    }
-}
-
 /// Checks that the ABI of a given instance of a function does not contain vector-passed arguments
 /// or return values for which the corresponding target feature is not enabled.
 fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) {
@@ -173,7 +103,6 @@ fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) {
         )
     };
     do_check_simd_vector_abi(tcx, abi, instance.def_id(), /*is_call*/ false, loc);
-    do_check_wasm_abi(tcx, abi, /*is_call*/ false, loc);
 }
 
 /// Checks that a call expression does not try to pass a vector-passed argument which requires a
@@ -212,7 +141,6 @@ fn check_call_site_abi<'tcx>(
         return;
     };
     do_check_simd_vector_abi(tcx, callee_abi, caller.def_id(), /*is_call*/ true, loc);
-    do_check_wasm_abi(tcx, callee_abi, /*is_call*/ true, loc);
 }
 
 fn check_callees_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>, body: &mir::Body<'tcx>) {
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index b49a13ce584..a64bb424117 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -686,23 +686,34 @@ impl<'a> Parser<'a> {
         }
 
         if let token::DocComment(kind, style, _) = self.token.kind {
-            // We have something like `expr //!val` where the user likely meant `expr // !val`
-            let pos = self.token.span.lo() + BytePos(2);
-            let span = self.token.span.with_lo(pos).with_hi(pos);
-            err.span_suggestion_verbose(
-                span,
-                format!(
-                    "add a space before {} to write a regular comment",
-                    match (kind, style) {
-                        (token::CommentKind::Line, ast::AttrStyle::Inner) => "`!`",
-                        (token::CommentKind::Block, ast::AttrStyle::Inner) => "`!`",
-                        (token::CommentKind::Line, ast::AttrStyle::Outer) => "the last `/`",
-                        (token::CommentKind::Block, ast::AttrStyle::Outer) => "the last `*`",
-                    },
-                ),
-                " ".to_string(),
-                Applicability::MachineApplicable,
-            );
+            // This is to avoid suggesting converting a doc comment to a regular comment
+            // when missing a comma before the doc comment in lists (#142311):
+            //
+            // ```
+            // enum Foo{
+            //     A /// xxxxxxx
+            //     B,
+            // }
+            // ```
+            if !expected.contains(&TokenType::Comma) {
+                // We have something like `expr //!val` where the user likely meant `expr // !val`
+                let pos = self.token.span.lo() + BytePos(2);
+                let span = self.token.span.with_lo(pos).with_hi(pos);
+                err.span_suggestion_verbose(
+                    span,
+                    format!(
+                        "add a space before {} to write a regular comment",
+                        match (kind, style) {
+                            (token::CommentKind::Line, ast::AttrStyle::Inner) => "`!`",
+                            (token::CommentKind::Block, ast::AttrStyle::Inner) => "`!`",
+                            (token::CommentKind::Line, ast::AttrStyle::Outer) => "the last `/`",
+                            (token::CommentKind::Block, ast::AttrStyle::Outer) => "the last `*`",
+                        },
+                    ),
+                    " ".to_string(),
+                    Applicability::MaybeIncorrect,
+                );
+            }
         }
 
         let sp = if self.token == token::Eof {
@@ -2273,23 +2284,18 @@ impl<'a> Parser<'a> {
                     ),
                     // Also catches `fn foo(&a)`.
                     PatKind::Ref(ref inner_pat, mutab)
-                        if matches!(inner_pat.clone().kind, PatKind::Ident(..)) =>
+                        if let PatKind::Ident(_, ident, _) = inner_pat.clone().kind =>
                     {
-                        match inner_pat.clone().kind {
-                            PatKind::Ident(_, ident, _) => {
-                                let mutab = mutab.prefix_str();
-                                (
-                                    ident,
-                                    "self: ",
-                                    format!("{ident}: &{mutab}TypeName"),
-                                    "_: ",
-                                    pat.span.shrink_to_lo(),
-                                    pat.span,
-                                    pat.span.shrink_to_lo(),
-                                )
-                            }
-                            _ => unreachable!(),
-                        }
+                        let mutab = mutab.prefix_str();
+                        (
+                            ident,
+                            "self: ",
+                            format!("{ident}: &{mutab}TypeName"),
+                            "_: ",
+                            pat.span.shrink_to_lo(),
+                            pat.span,
+                            pat.span.shrink_to_lo(),
+                        )
                     }
                     _ => {
                         // Otherwise, try to get a type and emit a suggestion.
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 4e2be8ff0b8..dddbf65db72 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -147,6 +147,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::ConstStabilityIndirect
                     | AttributeKind::MacroTransparency(_),
                 ) => { /* do nothing  */ }
+                Attribute::Parsed(AttributeKind::AsPtr(attr_span)) => {
+                    self.check_applied_to_fn_or_method(hir_id, *attr_span, span, target)
+                }
                 Attribute::Unparsed(_) => {
                     match attr.path().as_slice() {
                         [sym::diagnostic, sym::do_not_recommend, ..] => {
@@ -188,26 +191,23 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             self.check_rustc_std_internal_symbol(attr, span, target)
                         }
                         [sym::naked, ..] => self.check_naked(hir_id, attr, span, target, attrs),
-                        [sym::rustc_as_ptr, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-                        }
                         [sym::rustc_no_implicit_autorefs, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                            self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
                         [sym::rustc_never_returns_null_ptr, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                            self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
                         [sym::rustc_legacy_const_generics, ..] => {
                             self.check_rustc_legacy_const_generics(hir_id, attr, span, target, item)
                         }
                         [sym::rustc_lint_query_instability, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                            self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
                         [sym::rustc_lint_untracked_query_information, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                            self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
                         [sym::rustc_lint_diagnostics, ..] => {
-                            self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                            self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
                         [sym::rustc_lint_opt_ty, ..] => self.check_rustc_lint_opt_ty(attr, span, target),
                         [sym::rustc_lint_opt_deny_field_access, ..] => {
@@ -1825,15 +1825,15 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     fn check_applied_to_fn_or_method(
         &self,
         hir_id: HirId,
-        attr: &Attribute,
-        span: Span,
+        attr_span: Span,
+        defn_span: Span,
         target: Target,
     ) {
         let is_function = matches!(target, Target::Fn | Target::Method(..));
         if !is_function {
             self.dcx().emit_err(errors::AttrShouldBeAppliedToFn {
-                attr_span: attr.span(),
-                defn_span: span,
+                attr_span,
+                defn_span,
                 on_crate: hir_id == CRATE_HIR_ID,
             });
         }
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index fa4b024c422..338d9edcd22 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -415,24 +415,24 @@ pub(crate) enum AliasPossibility {
 }
 
 #[derive(Copy, Clone, Debug)]
-pub(crate) enum PathSource<'a, 'c> {
+pub(crate) enum PathSource<'a, 'ast, 'ra> {
     /// Type paths `Path`.
     Type,
     /// Trait paths in bounds or impls.
     Trait(AliasPossibility),
     /// Expression paths `path`, with optional parent context.
-    Expr(Option<&'a Expr>),
+    Expr(Option<&'ast Expr>),
     /// Paths in path patterns `Path`.
     Pat,
     /// Paths in struct expressions and patterns `Path { .. }`.
     Struct,
     /// Paths in tuple struct patterns `Path(..)`.
-    TupleStruct(Span, &'a [Span]),
+    TupleStruct(Span, &'ra [Span]),
     /// `m::A::B` in `<T as m::A>::B::C`.
     ///
     /// Second field holds the "cause" of this one, i.e. the context within
     /// which the trait item is resolved. Used for diagnostics.
-    TraitItem(Namespace, &'c PathSource<'a, 'c>),
+    TraitItem(Namespace, &'a PathSource<'a, 'ast, 'ra>),
     /// Paths in delegation item
     Delegation,
     /// An arg in a `use<'a, N>` precise-capturing bound.
@@ -443,7 +443,7 @@ pub(crate) enum PathSource<'a, 'c> {
     DefineOpaques,
 }
 
-impl<'a> PathSource<'a, '_> {
+impl PathSource<'_, '_, '_> {
     fn namespace(self) -> Namespace {
         match self {
             PathSource::Type
@@ -773,7 +773,7 @@ struct LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 }
 
 /// Walks the whole crate in DFS order, visiting each item, resolving names as it goes.
-impl<'ra: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
+impl<'ast, 'ra, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn visit_attribute(&mut self, _: &'ast Attribute) {
         // We do not want to resolve expressions that appear in attributes,
         // as they do not correspond to actual code.
@@ -1462,7 +1462,7 @@ impl<'ra: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'r
     }
 }
 
-impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
+impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
     fn new(resolver: &'a mut Resolver<'ra, 'tcx>) -> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         // During late resolution we only track the module component of the parent scope,
         // although it may be useful to track other components as well for diagnostics.
@@ -2010,7 +2010,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         &mut self,
         partial_res: PartialRes,
         path: &[Segment],
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path_span: Span,
     ) {
         let proj_start = path.len() - partial_res.unresolved_segments();
@@ -4161,7 +4161,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         id: NodeId,
         qself: &Option<P<QSelf>>,
         path: &Path,
-        source: PathSource<'ast, '_>,
+        source: PathSource<'_, 'ast, '_>,
     ) {
         self.smart_resolve_path_fragment(
             qself,
@@ -4178,7 +4178,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         &mut self,
         qself: &Option<P<QSelf>>,
         path: &[Segment],
-        source: PathSource<'ast, '_>,
+        source: PathSource<'_, 'ast, '_>,
         finalize: Finalize,
         record_partial_res: RecordPartialRes,
         parent_qself: Option<&QSelf>,
@@ -4482,7 +4482,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         span: Span,
         defer_to_typeck: bool,
         finalize: Finalize,
-        source: PathSource<'ast, '_>,
+        source: PathSource<'_, 'ast, '_>,
     ) -> Result<Option<PartialRes>, Spanned<ResolutionError<'ra>>> {
         let mut fin_res = None;
 
@@ -4525,7 +4525,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         path: &[Segment],
         ns: Namespace,
         finalize: Finalize,
-        source: PathSource<'ast, '_>,
+        source: PathSource<'_, 'ast, '_>,
     ) -> Result<Option<PartialRes>, Spanned<ResolutionError<'ra>>> {
         debug!(
             "resolve_qpath(qself={:?}, path={:?}, ns={:?}, finalize={:?})",
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 2f6aed35f25..d5dd3bdb6cd 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -170,12 +170,12 @@ impl TypoCandidate {
     }
 }
 
-impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
+impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn make_base_error(
         &mut self,
         path: &[Segment],
         span: Span,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         res: Option<Res>,
     ) -> BaseError {
         // Make the base error.
@@ -421,7 +421,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         path: &[Segment],
         following_seg: Option<&Segment>,
         span: Span,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         res: Option<Res>,
         qself: Option<&QSelf>,
     ) -> (Diag<'tcx>, Vec<ImportSuggestion>) {
@@ -539,7 +539,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         path: &[Segment],
         following_seg: Option<&Segment>,
         span: Span,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         res: Option<Res>,
         qself: Option<&QSelf>,
     ) {
@@ -650,7 +650,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn try_lookup_name_relaxed(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         following_seg: Option<&Segment>,
         span: Span,
@@ -940,7 +940,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_trait_and_bounds(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         res: Option<Res>,
         span: Span,
         base_error: &BaseError,
@@ -1017,7 +1017,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_typo(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         following_seg: Option<&Segment>,
         span: Span,
@@ -1063,7 +1063,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_shadowed(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         following_seg: Option<&Segment>,
         span: Span,
@@ -1096,7 +1096,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn err_code_special_cases(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         span: Span,
     ) {
@@ -1141,7 +1141,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_self_ty(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         span: Span,
     ) -> bool {
@@ -1164,7 +1164,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_self_value(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         span: Span,
     ) -> bool {
@@ -1332,7 +1332,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_swapping_misplaced_self_ty_and_trait(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         res: Option<Res>,
         span: Span,
     ) {
@@ -1361,7 +1361,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         &mut self,
         err: &mut Diag<'_>,
         res: Option<Res>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
     ) {
         let PathSource::TupleStruct(_, _) = source else { return };
         let Some(Res::Def(DefKind::Fn, _)) = res else { return };
@@ -1373,7 +1373,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         &mut self,
         err: &mut Diag<'_>,
         res: Option<Res>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         span: Span,
     ) {
         let PathSource::Trait(_) = source else { return };
@@ -1422,7 +1422,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_pattern_match_with_let(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         span: Span,
     ) -> bool {
         if let PathSource::Expr(_) = source
@@ -1448,7 +1448,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn get_single_associated_item(
         &mut self,
         path: &[Segment],
-        source: &PathSource<'_, '_>,
+        source: &PathSource<'_, '_, '_>,
         filter_fn: &impl Fn(Res) -> bool,
     ) -> Option<TypoSuggestion> {
         if let crate::PathSource::TraitItem(_, _) = source {
@@ -1556,7 +1556,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
 
     /// Check if the source is call expression and the first argument is `self`. If true,
     /// return the span of whole call and the span for all arguments expect the first one (`self`).
-    fn call_has_self_arg(&self, source: PathSource<'_, '_>) -> Option<(Span, Option<Span>)> {
+    fn call_has_self_arg(&self, source: PathSource<'_, '_, '_>) -> Option<(Span, Option<Span>)> {
         let mut has_self_arg = None;
         if let PathSource::Expr(Some(parent)) = source
             && let ExprKind::Call(_, args) = &parent.kind
@@ -1614,7 +1614,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         &mut self,
         err: &mut Diag<'_>,
         span: Span,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         path: &[Segment],
         res: Res,
         path_str: &str,
@@ -1666,7 +1666,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             }
         };
 
-        let find_span = |source: &PathSource<'_, '_>, err: &mut Diag<'_>| {
+        let find_span = |source: &PathSource<'_, '_, '_>, err: &mut Diag<'_>| {
             match source {
                 PathSource::Expr(Some(Expr { span, kind: ExprKind::Call(_, _), .. }))
                 | PathSource::TupleStruct(span, _) => {
@@ -2699,7 +2699,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     fn suggest_using_enum_variant(
         &mut self,
         err: &mut Diag<'_>,
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
         def_id: DefId,
         span: Span,
     ) {
@@ -2877,7 +2877,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
     pub(crate) fn suggest_adding_generic_parameter(
         &self,
         path: &[Segment],
-        source: PathSource<'_, '_>,
+        source: PathSource<'_, '_, '_>,
     ) -> Option<(Span, &'static str, String, Applicability)> {
         let (ident, span) = match path {
             [segment]
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 8984634e5ec..406a6bd335a 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -3066,7 +3066,7 @@ pub(crate) mod dep_tracking {
     use rustc_target::spec::{
         CodeModel, FramePointer, MergeFunctions, OnBrokenPipe, PanicStrategy, RelocModel,
         RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, SymbolVisibility, TargetTuple,
-        TlsModel, WasmCAbi,
+        TlsModel,
     };
 
     use super::{
@@ -3177,7 +3177,6 @@ pub(crate) mod dep_tracking {
         Polonius,
         InliningThreshold,
         FunctionReturn,
-        WasmCAbi,
         Align,
     );
 
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 6218521d4f0..f76f258d00d 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -16,7 +16,7 @@ use rustc_span::{RealFileName, SourceFileHashAlgorithm};
 use rustc_target::spec::{
     CodeModel, FramePointer, LinkerFlavorCli, MergeFunctions, OnBrokenPipe, PanicStrategy,
     RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, SymbolVisibility,
-    TargetTuple, TlsModel, WasmCAbi,
+    TargetTuple, TlsModel,
 };
 
 use crate::config::*;
@@ -802,7 +802,6 @@ mod desc {
         "either a boolean (`yes`, `no`, `on`, `off`, etc), or a non-negative number";
     pub(crate) const parse_llvm_module_flag: &str = "<key>:<type>:<value>:<behavior>. Type must currently be `u32`. Behavior should be one of (`error`, `warning`, `require`, `override`, `append`, `appendunique`, `max`, `min`)";
     pub(crate) const parse_function_return: &str = "`keep` or `thunk-extern`";
-    pub(crate) const parse_wasm_c_abi: &str = "`legacy` or `spec`";
     pub(crate) const parse_mir_include_spans: &str =
         "either a boolean (`yes`, `no`, `on`, `off`, etc), or `nll` (default: `nll`)";
     pub(crate) const parse_align: &str = "a number that is a power of 2 between 1 and 2^29";
@@ -1898,16 +1897,6 @@ pub mod parse {
         true
     }
 
-    pub(crate) fn parse_wasm_c_abi(slot: &mut WasmCAbi, v: Option<&str>) -> bool {
-        match v {
-            Some("spec") => *slot = WasmCAbi::Spec,
-            // Explicitly setting the `-Z` flag suppresses the lint.
-            Some("legacy") => *slot = WasmCAbi::Legacy { with_lint: false },
-            _ => return false,
-        }
-        true
-    }
-
     pub(crate) fn parse_mir_include_spans(slot: &mut MirIncludeSpans, v: Option<&str>) -> bool {
         *slot = match v {
             Some("on" | "yes" | "y" | "true") | None => MirIncludeSpans::On,
@@ -2642,8 +2631,6 @@ written to standard error output)"),
         Requires `-Clto[=[fat,yes]]`"),
     wasi_exec_model: Option<WasiExecModel> = (None, parse_wasi_exec_model, [TRACKED],
         "whether to build a wasi command or reactor"),
-    wasm_c_abi: WasmCAbi = (WasmCAbi::Legacy { with_lint: true }, parse_wasm_c_abi, [TRACKED],
-        "use spec-compliant C ABI for `wasm32-unknown-unknown` (default: legacy)"),
     write_long_types_to_disk: bool = (true, parse_bool, [UNTRACKED],
         "whether long type names should be written to files instead of being printed in errors"),
     // tidy-alphabetical-end
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 6b85e0abc86..b8b4518b14e 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -215,13 +215,6 @@ pub struct Session {
     pub invocation_temp: Option<String>,
 }
 
-#[derive(PartialEq, Eq, PartialOrd, Ord)]
-pub enum MetadataKind {
-    None,
-    Uncompressed,
-    Compressed,
-}
-
 #[derive(Clone, Copy)]
 pub enum CodegenUnits {
     /// Specified by the user. In this case we try fairly hard to produce the
diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs
index ef8c88355f6..baa4c0681e8 100644
--- a/compiler/rustc_smir/src/rustc_smir/context.rs
+++ b/compiler/rustc_smir/src/rustc_smir/context.rs
@@ -12,7 +12,8 @@ use rustc_middle::ty::layout::{
 };
 use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths};
 use rustc_middle::ty::{
-    GenericPredicates, Instance, List, ScalarInt, TyCtxt, TypeVisitableExt, ValTree,
+    CoroutineArgsExt, GenericPredicates, Instance, List, ScalarInt, TyCtxt, TypeVisitableExt,
+    ValTree,
 };
 use rustc_middle::{mir, ty};
 use rustc_span::def_id::LOCAL_CRATE;
@@ -22,9 +23,9 @@ use stable_mir::mir::mono::{InstanceDef, StaticDef};
 use stable_mir::mir::{BinOp, Body, Place, UnOp};
 use stable_mir::target::{MachineInfo, MachineSize};
 use stable_mir::ty::{
-    AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, FieldDef, FnDef, ForeignDef,
-    ForeignItemKind, GenericArgs, IntrinsicDef, LineInfo, MirConst, PolyFnSig, RigidTy, Span, Ty,
-    TyConst, TyKind, UintTy, VariantDef,
+    AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, CoroutineDef, Discr, FieldDef, FnDef,
+    ForeignDef, ForeignItemKind, GenericArgs, IntrinsicDef, LineInfo, MirConst, PolyFnSig, RigidTy,
+    Span, Ty, TyConst, TyKind, UintTy, VariantDef, VariantIdx,
 };
 use stable_mir::{Crate, CrateDef, CrateItem, CrateNum, DefId, Error, Filename, ItemKind, Symbol};
 
@@ -447,6 +448,30 @@ impl<'tcx> SmirCtxt<'tcx> {
         def.internal(&mut *tables, tcx).variants().len()
     }
 
+    /// Discriminant for a given variant index of AdtDef
+    pub fn adt_discr_for_variant(&self, adt: AdtDef, variant: VariantIdx) -> Discr {
+        let mut tables = self.0.borrow_mut();
+        let tcx = tables.tcx;
+        let adt = adt.internal(&mut *tables, tcx);
+        let variant = variant.internal(&mut *tables, tcx);
+        adt.discriminant_for_variant(tcx, variant).stable(&mut *tables)
+    }
+
+    /// Discriminant for a given variand index and args of a coroutine
+    pub fn coroutine_discr_for_variant(
+        &self,
+        coroutine: CoroutineDef,
+        args: &GenericArgs,
+        variant: VariantIdx,
+    ) -> Discr {
+        let mut tables = self.0.borrow_mut();
+        let tcx = tables.tcx;
+        let coroutine = coroutine.def_id().internal(&mut *tables, tcx);
+        let args = args.internal(&mut *tables, tcx);
+        let variant = variant.internal(&mut *tables, tcx);
+        args.as_coroutine().discriminant_for_variant(coroutine, tcx, variant).stable(&mut *tables)
+    }
+
     /// The name of a variant.
     pub fn variant_name(&self, def: VariantDef) -> Symbol {
         let mut tables = self.0.borrow_mut();
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
index 6a26f5f7997..b4239ddd896 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
@@ -960,3 +960,11 @@ impl<'tcx> Stable<'tcx> for ty::ImplTraitInTraitData {
         }
     }
 }
+
+impl<'tcx> Stable<'tcx> for rustc_middle::ty::util::Discr<'tcx> {
+    type T = stable_mir::ty::Discr;
+
+    fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
+        stable_mir::ty::Discr { val: self.val, ty: self.ty.stable(tables) }
+    }
+}
diff --git a/compiler/rustc_smir/src/stable_mir/compiler_interface.rs b/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
index 3967ad13eeb..2668fba9f4f 100644
--- a/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
+++ b/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
@@ -13,10 +13,10 @@ use stable_mir::mir::mono::{Instance, InstanceDef, StaticDef};
 use stable_mir::mir::{BinOp, Body, Place, UnOp};
 use stable_mir::target::MachineInfo;
 use stable_mir::ty::{
-    AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, FieldDef, FnDef, ForeignDef,
-    ForeignItemKind, ForeignModule, ForeignModuleDef, GenericArgs, GenericPredicates, Generics,
-    ImplDef, ImplTrait, IntrinsicDef, LineInfo, MirConst, PolyFnSig, RigidTy, Span, TraitDecl,
-    TraitDef, Ty, TyConst, TyConstId, TyKind, UintTy, VariantDef,
+    AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, CoroutineDef, Discr, FieldDef, FnDef,
+    ForeignDef, ForeignItemKind, ForeignModule, ForeignModuleDef, GenericArgs, GenericPredicates,
+    Generics, ImplDef, ImplTrait, IntrinsicDef, LineInfo, MirConst, PolyFnSig, RigidTy, Span,
+    TraitDecl, TraitDef, Ty, TyConst, TyConstId, TyKind, UintTy, VariantDef, VariantIdx,
 };
 use stable_mir::{
     AssocItems, Crate, CrateItem, CrateItems, CrateNum, DefId, Error, Filename, ImplTraitDecls,
@@ -230,6 +230,21 @@ impl<'tcx> SmirInterface<'tcx> {
         self.cx.adt_variants_len(def)
     }
 
+    /// Discriminant for a given variant index of AdtDef
+    pub(crate) fn adt_discr_for_variant(&self, adt: AdtDef, variant: VariantIdx) -> Discr {
+        self.cx.adt_discr_for_variant(adt, variant)
+    }
+
+    /// Discriminant for a given variand index and args of a coroutine
+    pub(crate) fn coroutine_discr_for_variant(
+        &self,
+        coroutine: CoroutineDef,
+        args: &GenericArgs,
+        variant: VariantIdx,
+    ) -> Discr {
+        self.cx.coroutine_discr_for_variant(coroutine, args, variant)
+    }
+
     /// The name of a variant.
     pub(crate) fn variant_name(&self, def: VariantDef) -> Symbol {
         self.cx.variant_name(def)
diff --git a/compiler/rustc_smir/src/stable_mir/ty.rs b/compiler/rustc_smir/src/stable_mir/ty.rs
index 2934af31cd5..4415cd6e2e3 100644
--- a/compiler/rustc_smir/src/stable_mir/ty.rs
+++ b/compiler/rustc_smir/src/stable_mir/ty.rs
@@ -756,6 +756,12 @@ crate_def! {
     pub CoroutineDef;
 }
 
+impl CoroutineDef {
+    pub fn discriminant_for_variant(&self, args: &GenericArgs, idx: VariantIdx) -> Discr {
+        with(|cx| cx.coroutine_discr_for_variant(*self, args, idx))
+    }
+}
+
 crate_def! {
     #[derive(Serialize)]
     pub CoroutineClosureDef;
@@ -831,6 +837,15 @@ impl AdtDef {
     pub fn repr(&self) -> ReprOptions {
         with(|cx| cx.adt_repr(*self))
     }
+
+    pub fn discriminant_for_variant(&self, idx: VariantIdx) -> Discr {
+        with(|cx| cx.adt_discr_for_variant(*self, idx))
+    }
+}
+
+pub struct Discr {
+    pub val: u128,
+    pub ty: Ty,
 }
 
 /// Definition of a variant, which can be either a struct / union field or an enum variant.
diff --git a/compiler/rustc_target/src/asm/loongarch.rs b/compiler/rustc_target/src/asm/loongarch.rs
index 8783d3953b1..51e7ee8daa4 100644
--- a/compiler/rustc_target/src/asm/loongarch.rs
+++ b/compiler/rustc_target/src/asm/loongarch.rs
@@ -37,9 +37,11 @@ impl LoongArchInlineAsmRegClass {
         arch: InlineAsmArch,
     ) -> &'static [(InlineAsmType, Option<Symbol>)] {
         match (self, arch) {
-            (Self::reg, InlineAsmArch::LoongArch64) => types! { _: I8, I16, I32, I64, F32, F64; },
-            (Self::reg, InlineAsmArch::LoongArch32) => types! { _: I8, I16, I32, F32; },
-            (Self::freg, _) => types! { f: F32; d: F64; },
+            (Self::reg, InlineAsmArch::LoongArch64) => {
+                types! { _: I8, I16, I32, I64, F16, F32, F64; }
+            }
+            (Self::reg, InlineAsmArch::LoongArch32) => types! { _: I8, I16, I32, F16, F32; },
+            (Self::freg, _) => types! { f: F16, F32; d: F64; },
             _ => unreachable!("unsupported register class"),
         }
     }
diff --git a/compiler/rustc_target/src/callconv/mips64.rs b/compiler/rustc_target/src/callconv/mips64.rs
index 89f324bc313..77c0cf06fc1 100644
--- a/compiler/rustc_target/src/callconv/mips64.rs
+++ b/compiler/rustc_target/src/callconv/mips64.rs
@@ -2,9 +2,7 @@ use rustc_abi::{
     BackendRepr, FieldsShape, Float, HasDataLayout, Primitive, Reg, Size, TyAbiInterface,
 };
 
-use crate::callconv::{
-    ArgAbi, ArgAttribute, ArgAttributes, ArgExtension, CastTarget, FnAbi, PassMode, Uniform,
-};
+use crate::callconv::{ArgAbi, ArgExtension, CastTarget, FnAbi, PassMode, Uniform};
 
 fn extend_integer_width_mips<Ty>(arg: &mut ArgAbi<'_, Ty>, bits: u64) {
     // Always sign extend u32 values on 64-bit mips
@@ -140,16 +138,7 @@ where
 
     // Extract first 8 chunks as the prefix
     let rest_size = size - Size::from_bytes(8) * prefix_index as u64;
-    arg.cast_to(CastTarget {
-        prefix,
-        rest: Uniform::new(Reg::i64(), rest_size),
-        attrs: ArgAttributes {
-            regular: ArgAttribute::default(),
-            arg_ext: ArgExtension::None,
-            pointee_size: Size::ZERO,
-            pointee_align: None,
-        },
-    });
+    arg.cast_to(CastTarget::prefixed(prefix, Uniform::new(Reg::i64(), rest_size)));
 }
 
 pub(crate) fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
diff --git a/compiler/rustc_target/src/callconv/mod.rs b/compiler/rustc_target/src/callconv/mod.rs
index f9ecf02f857..71cc2a45563 100644
--- a/compiler/rustc_target/src/callconv/mod.rs
+++ b/compiler/rustc_target/src/callconv/mod.rs
@@ -7,7 +7,7 @@ use rustc_abi::{
 use rustc_macros::HashStable_Generic;
 
 pub use crate::spec::AbiMap;
-use crate::spec::{HasTargetSpec, HasWasmCAbiOpt, HasX86AbiOpt, WasmCAbi};
+use crate::spec::{HasTargetSpec, HasX86AbiOpt};
 
 mod aarch64;
 mod amdgpu;
@@ -197,6 +197,17 @@ impl ArgAttributes {
     }
 }
 
+impl From<ArgAttribute> for ArgAttributes {
+    fn from(value: ArgAttribute) -> Self {
+        Self {
+            regular: value,
+            arg_ext: ArgExtension::None,
+            pointee_size: Size::ZERO,
+            pointee_align: None,
+        }
+    }
+}
+
 /// An argument passed entirely registers with the
 /// same kind (e.g., HFA / HVA on PPC64 and AArch64).
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, HashStable_Generic)]
@@ -251,6 +262,9 @@ impl Uniform {
 #[derive(Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic)]
 pub struct CastTarget {
     pub prefix: [Option<Reg>; 8],
+    /// The offset of `rest` from the start of the value. Currently only implemented for a `Reg`
+    /// pair created by the `offset_pair` method.
+    pub rest_offset: Option<Size>,
     pub rest: Uniform,
     pub attrs: ArgAttributes,
 }
@@ -263,42 +277,45 @@ impl From<Reg> for CastTarget {
 
 impl From<Uniform> for CastTarget {
     fn from(uniform: Uniform) -> CastTarget {
-        CastTarget {
-            prefix: [None; 8],
-            rest: uniform,
-            attrs: ArgAttributes {
-                regular: ArgAttribute::default(),
-                arg_ext: ArgExtension::None,
-                pointee_size: Size::ZERO,
-                pointee_align: None,
-            },
-        }
+        Self::prefixed([None; 8], uniform)
     }
 }
 
 impl CastTarget {
-    pub fn pair(a: Reg, b: Reg) -> CastTarget {
-        CastTarget {
+    pub fn prefixed(prefix: [Option<Reg>; 8], rest: Uniform) -> Self {
+        Self { prefix, rest_offset: None, rest, attrs: ArgAttributes::new() }
+    }
+
+    pub fn offset_pair(a: Reg, offset_from_start: Size, b: Reg) -> Self {
+        Self {
             prefix: [Some(a), None, None, None, None, None, None, None],
-            rest: Uniform::from(b),
-            attrs: ArgAttributes {
-                regular: ArgAttribute::default(),
-                arg_ext: ArgExtension::None,
-                pointee_size: Size::ZERO,
-                pointee_align: None,
-            },
+            rest_offset: Some(offset_from_start),
+            rest: b.into(),
+            attrs: ArgAttributes::new(),
         }
     }
 
+    pub fn with_attrs(mut self, attrs: ArgAttributes) -> Self {
+        self.attrs = attrs;
+        self
+    }
+
+    pub fn pair(a: Reg, b: Reg) -> CastTarget {
+        Self::prefixed([Some(a), None, None, None, None, None, None, None], Uniform::from(b))
+    }
+
     /// When you only access the range containing valid data, you can use this unaligned size;
     /// otherwise, use the safer `size` method.
     pub fn unaligned_size<C: HasDataLayout>(&self, _cx: &C) -> Size {
         // Prefix arguments are passed in specific designated registers
-        let prefix_size = self
-            .prefix
-            .iter()
-            .filter_map(|x| x.map(|reg| reg.size))
-            .fold(Size::ZERO, |acc, size| acc + size);
+        let prefix_size = if let Some(offset_from_start) = self.rest_offset {
+            offset_from_start
+        } else {
+            self.prefix
+                .iter()
+                .filter_map(|x| x.map(|reg| reg.size))
+                .fold(Size::ZERO, |acc, size| acc + size)
+        };
         // Remaining arguments are passed in chunks of the unit size
         let rest_size =
             self.rest.unit.size * self.rest.total.bytes().div_ceil(self.rest.unit.size.bytes());
@@ -322,9 +339,22 @@ impl CastTarget {
     /// Checks if these two `CastTarget` are equal enough to be considered "the same for all
     /// function call ABIs".
     pub fn eq_abi(&self, other: &Self) -> bool {
-        let CastTarget { prefix: prefix_l, rest: rest_l, attrs: attrs_l } = self;
-        let CastTarget { prefix: prefix_r, rest: rest_r, attrs: attrs_r } = other;
-        prefix_l == prefix_r && rest_l == rest_r && attrs_l.eq_abi(attrs_r)
+        let CastTarget {
+            prefix: prefix_l,
+            rest_offset: rest_offset_l,
+            rest: rest_l,
+            attrs: attrs_l,
+        } = self;
+        let CastTarget {
+            prefix: prefix_r,
+            rest_offset: rest_offset_r,
+            rest: rest_r,
+            attrs: attrs_r,
+        } = other;
+        prefix_l == prefix_r
+            && rest_offset_l == rest_offset_r
+            && rest_l == rest_r
+            && attrs_l.eq_abi(attrs_r)
     }
 }
 
@@ -593,7 +623,7 @@ impl<'a, Ty> FnAbi<'a, Ty> {
     pub fn adjust_for_foreign_abi<C>(&mut self, cx: &C, abi: ExternAbi)
     where
         Ty: TyAbiInterface<'a, C> + Copy,
-        C: HasDataLayout + HasTargetSpec + HasWasmCAbiOpt + HasX86AbiOpt,
+        C: HasDataLayout + HasTargetSpec + HasX86AbiOpt,
     {
         if abi == ExternAbi::X86Interrupt {
             if let Some(arg) = self.args.first_mut() {
@@ -669,14 +699,7 @@ impl<'a, Ty> FnAbi<'a, Ty> {
             "hexagon" => hexagon::compute_abi_info(self),
             "xtensa" => xtensa::compute_abi_info(cx, self),
             "riscv32" | "riscv64" => riscv::compute_abi_info(cx, self),
-            "wasm32" => {
-                if spec.os == "unknown" && matches!(cx.wasm_c_abi_opt(), WasmCAbi::Legacy { .. }) {
-                    wasm::compute_wasm_abi_info(self)
-                } else {
-                    wasm::compute_c_abi_info(cx, self)
-                }
-            }
-            "wasm64" => wasm::compute_c_abi_info(cx, self),
+            "wasm32" | "wasm64" => wasm::compute_abi_info(cx, self),
             "bpf" => bpf::compute_abi_info(self),
             arch => panic!("no lowering implemented for {arch}"),
         }
diff --git a/compiler/rustc_target/src/callconv/nvptx64.rs b/compiler/rustc_target/src/callconv/nvptx64.rs
index a26e7dac5ba..44977de7fcb 100644
--- a/compiler/rustc_target/src/callconv/nvptx64.rs
+++ b/compiler/rustc_target/src/callconv/nvptx64.rs
@@ -1,6 +1,6 @@
 use rustc_abi::{HasDataLayout, Reg, Size, TyAbiInterface};
 
-use super::{ArgAttribute, ArgAttributes, ArgExtension, CastTarget};
+use super::CastTarget;
 use crate::callconv::{ArgAbi, FnAbi, Uniform};
 
 fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
@@ -34,16 +34,10 @@ fn classify_aggregate<Ty>(arg: &mut ArgAbi<'_, Ty>) {
     };
 
     if align_bytes == size.bytes() {
-        arg.cast_to(CastTarget {
-            prefix: [Some(reg), None, None, None, None, None, None, None],
-            rest: Uniform::new(Reg::i8(), Size::from_bytes(0)),
-            attrs: ArgAttributes {
-                regular: ArgAttribute::default(),
-                arg_ext: ArgExtension::None,
-                pointee_size: Size::ZERO,
-                pointee_align: None,
-            },
-        });
+        arg.cast_to(CastTarget::prefixed(
+            [Some(reg), None, None, None, None, None, None, None],
+            Uniform::new(Reg::i8(), Size::ZERO),
+        ));
     } else {
         arg.cast_to(Uniform::new(reg, size));
     }
@@ -78,11 +72,10 @@ where
     };
     if arg.layout.size.bytes() / align_bytes == 1 {
         // Make sure we pass the struct as array at the LLVM IR level and not as a single integer.
-        arg.cast_to(CastTarget {
-            prefix: [Some(unit), None, None, None, None, None, None, None],
-            rest: Uniform::new(unit, Size::ZERO),
-            attrs: ArgAttributes::new(),
-        });
+        arg.cast_to(CastTarget::prefixed(
+            [Some(unit), None, None, None, None, None, None, None],
+            Uniform::new(unit, Size::ZERO),
+        ));
     } else {
         arg.cast_to(Uniform::new(unit, arg.layout.size));
     }
diff --git a/compiler/rustc_target/src/callconv/riscv.rs b/compiler/rustc_target/src/callconv/riscv.rs
index cd1d3cd1eee..6a2038f9381 100644
--- a/compiler/rustc_target/src/callconv/riscv.rs
+++ b/compiler/rustc_target/src/callconv/riscv.rs
@@ -14,16 +14,16 @@ use crate::spec::HasTargetSpec;
 
 #[derive(Copy, Clone)]
 enum RegPassKind {
-    Float(Reg),
-    Integer(Reg),
+    Float { offset_from_start: Size, ty: Reg },
+    Integer { offset_from_start: Size, ty: Reg },
     Unknown,
 }
 
 #[derive(Copy, Clone)]
 enum FloatConv {
-    FloatPair(Reg, Reg),
+    FloatPair { first_ty: Reg, second_ty_offset_from_start: Size, second_ty: Reg },
     Float(Reg),
-    MixedPair(Reg, Reg),
+    MixedPair { first_ty: Reg, second_ty_offset_from_start: Size, second_ty: Reg },
 }
 
 #[derive(Copy, Clone)]
@@ -43,6 +43,7 @@ fn should_use_fp_conv_helper<'a, Ty, C>(
     flen: u64,
     field1_kind: &mut RegPassKind,
     field2_kind: &mut RegPassKind,
+    offset_from_start: Size,
 ) -> Result<(), CannotUseFpConv>
 where
     Ty: TyAbiInterface<'a, C> + Copy,
@@ -55,16 +56,16 @@ where
                 }
                 match (*field1_kind, *field2_kind) {
                     (RegPassKind::Unknown, _) => {
-                        *field1_kind = RegPassKind::Integer(Reg {
-                            kind: RegKind::Integer,
-                            size: arg_layout.size,
-                        });
+                        *field1_kind = RegPassKind::Integer {
+                            offset_from_start,
+                            ty: Reg { kind: RegKind::Integer, size: arg_layout.size },
+                        };
                     }
-                    (RegPassKind::Float(_), RegPassKind::Unknown) => {
-                        *field2_kind = RegPassKind::Integer(Reg {
-                            kind: RegKind::Integer,
-                            size: arg_layout.size,
-                        });
+                    (RegPassKind::Float { .. }, RegPassKind::Unknown) => {
+                        *field2_kind = RegPassKind::Integer {
+                            offset_from_start,
+                            ty: Reg { kind: RegKind::Integer, size: arg_layout.size },
+                        };
                     }
                     _ => return Err(CannotUseFpConv),
                 }
@@ -75,12 +76,16 @@ where
                 }
                 match (*field1_kind, *field2_kind) {
                     (RegPassKind::Unknown, _) => {
-                        *field1_kind =
-                            RegPassKind::Float(Reg { kind: RegKind::Float, size: arg_layout.size });
+                        *field1_kind = RegPassKind::Float {
+                            offset_from_start,
+                            ty: Reg { kind: RegKind::Float, size: arg_layout.size },
+                        };
                     }
                     (_, RegPassKind::Unknown) => {
-                        *field2_kind =
-                            RegPassKind::Float(Reg { kind: RegKind::Float, size: arg_layout.size });
+                        *field2_kind = RegPassKind::Float {
+                            offset_from_start,
+                            ty: Reg { kind: RegKind::Float, size: arg_layout.size },
+                        };
                     }
                     _ => return Err(CannotUseFpConv),
                 }
@@ -102,13 +107,14 @@ where
                             flen,
                             field1_kind,
                             field2_kind,
+                            offset_from_start,
                         );
                     }
                     return Err(CannotUseFpConv);
                 }
             }
             FieldsShape::Array { count, .. } => {
-                for _ in 0..count {
+                for i in 0..count {
                     let elem_layout = arg_layout.field(cx, 0);
                     should_use_fp_conv_helper(
                         cx,
@@ -117,6 +123,7 @@ where
                         flen,
                         field1_kind,
                         field2_kind,
+                        offset_from_start + elem_layout.size * i,
                     )?;
                 }
             }
@@ -127,7 +134,15 @@ where
                 }
                 for i in arg_layout.fields.index_by_increasing_offset() {
                     let field = arg_layout.field(cx, i);
-                    should_use_fp_conv_helper(cx, &field, xlen, flen, field1_kind, field2_kind)?;
+                    should_use_fp_conv_helper(
+                        cx,
+                        &field,
+                        xlen,
+                        flen,
+                        field1_kind,
+                        field2_kind,
+                        offset_from_start + arg_layout.fields.offset(i),
+                    )?;
                 }
             }
         },
@@ -146,14 +161,52 @@ where
 {
     let mut field1_kind = RegPassKind::Unknown;
     let mut field2_kind = RegPassKind::Unknown;
-    if should_use_fp_conv_helper(cx, arg, xlen, flen, &mut field1_kind, &mut field2_kind).is_err() {
+    if should_use_fp_conv_helper(
+        cx,
+        arg,
+        xlen,
+        flen,
+        &mut field1_kind,
+        &mut field2_kind,
+        Size::ZERO,
+    )
+    .is_err()
+    {
         return None;
     }
     match (field1_kind, field2_kind) {
-        (RegPassKind::Integer(l), RegPassKind::Float(r)) => Some(FloatConv::MixedPair(l, r)),
-        (RegPassKind::Float(l), RegPassKind::Integer(r)) => Some(FloatConv::MixedPair(l, r)),
-        (RegPassKind::Float(l), RegPassKind::Float(r)) => Some(FloatConv::FloatPair(l, r)),
-        (RegPassKind::Float(f), RegPassKind::Unknown) => Some(FloatConv::Float(f)),
+        (
+            RegPassKind::Integer { offset_from_start, .. }
+            | RegPassKind::Float { offset_from_start, .. },
+            _,
+        ) if offset_from_start != Size::ZERO => {
+            panic!("type {:?} has a first field with non-zero offset {offset_from_start:?}", arg.ty)
+        }
+        (
+            RegPassKind::Integer { ty: first_ty, .. },
+            RegPassKind::Float { offset_from_start, ty: second_ty },
+        ) => Some(FloatConv::MixedPair {
+            first_ty,
+            second_ty_offset_from_start: offset_from_start,
+            second_ty,
+        }),
+        (
+            RegPassKind::Float { ty: first_ty, .. },
+            RegPassKind::Integer { offset_from_start, ty: second_ty },
+        ) => Some(FloatConv::MixedPair {
+            first_ty,
+            second_ty_offset_from_start: offset_from_start,
+            second_ty,
+        }),
+        (
+            RegPassKind::Float { ty: first_ty, .. },
+            RegPassKind::Float { offset_from_start, ty: second_ty },
+        ) => Some(FloatConv::FloatPair {
+            first_ty,
+            second_ty_offset_from_start: offset_from_start,
+            second_ty,
+        }),
+        (RegPassKind::Float { ty, .. }, RegPassKind::Unknown) => Some(FloatConv::Float(ty)),
         _ => None,
     }
 }
@@ -171,11 +224,19 @@ where
             FloatConv::Float(f) => {
                 arg.cast_to(f);
             }
-            FloatConv::FloatPair(l, r) => {
-                arg.cast_to(CastTarget::pair(l, r));
+            FloatConv::FloatPair { first_ty, second_ty_offset_from_start, second_ty } => {
+                arg.cast_to(CastTarget::offset_pair(
+                    first_ty,
+                    second_ty_offset_from_start,
+                    second_ty,
+                ));
             }
-            FloatConv::MixedPair(l, r) => {
-                arg.cast_to(CastTarget::pair(l, r));
+            FloatConv::MixedPair { first_ty, second_ty_offset_from_start, second_ty } => {
+                arg.cast_to(CastTarget::offset_pair(
+                    first_ty,
+                    second_ty_offset_from_start,
+                    second_ty,
+                ));
             }
         }
         return false;
@@ -239,15 +300,27 @@ fn classify_arg<'a, Ty, C>(
                 arg.cast_to(f);
                 return;
             }
-            Some(FloatConv::FloatPair(l, r)) if *avail_fprs >= 2 => {
+            Some(FloatConv::FloatPair { first_ty, second_ty_offset_from_start, second_ty })
+                if *avail_fprs >= 2 =>
+            {
                 *avail_fprs -= 2;
-                arg.cast_to(CastTarget::pair(l, r));
+                arg.cast_to(CastTarget::offset_pair(
+                    first_ty,
+                    second_ty_offset_from_start,
+                    second_ty,
+                ));
                 return;
             }
-            Some(FloatConv::MixedPair(l, r)) if *avail_fprs >= 1 && *avail_gprs >= 1 => {
+            Some(FloatConv::MixedPair { first_ty, second_ty_offset_from_start, second_ty })
+                if *avail_fprs >= 1 && *avail_gprs >= 1 =>
+            {
                 *avail_gprs -= 1;
                 *avail_fprs -= 1;
-                arg.cast_to(CastTarget::pair(l, r));
+                arg.cast_to(CastTarget::offset_pair(
+                    first_ty,
+                    second_ty_offset_from_start,
+                    second_ty,
+                ));
                 return;
             }
             _ => (),
diff --git a/compiler/rustc_target/src/callconv/sparc64.rs b/compiler/rustc_target/src/callconv/sparc64.rs
index 7ca0031fc59..186826c08fc 100644
--- a/compiler/rustc_target/src/callconv/sparc64.rs
+++ b/compiler/rustc_target/src/callconv/sparc64.rs
@@ -5,9 +5,7 @@ use rustc_abi::{
     TyAndLayout,
 };
 
-use crate::callconv::{
-    ArgAbi, ArgAttribute, ArgAttributes, ArgExtension, CastTarget, FnAbi, Uniform,
-};
+use crate::callconv::{ArgAbi, ArgAttribute, CastTarget, FnAbi, Uniform};
 use crate::spec::HasTargetSpec;
 
 #[derive(Clone, Debug)]
@@ -197,16 +195,10 @@ where
                     rest_size = rest_size - Reg::i32().size;
                 }
 
-                arg.cast_to(CastTarget {
-                    prefix: data.prefix,
-                    rest: Uniform::new(Reg::i64(), rest_size),
-                    attrs: ArgAttributes {
-                        regular: data.arg_attribute,
-                        arg_ext: ArgExtension::None,
-                        pointee_size: Size::ZERO,
-                        pointee_align: None,
-                    },
-                });
+                arg.cast_to(
+                    CastTarget::prefixed(data.prefix, Uniform::new(Reg::i64(), rest_size))
+                        .with_attrs(data.arg_attribute.into()),
+                );
                 return;
             }
         }
diff --git a/compiler/rustc_target/src/callconv/wasm.rs b/compiler/rustc_target/src/callconv/wasm.rs
index 881168c98c3..a308f378ee8 100644
--- a/compiler/rustc_target/src/callconv/wasm.rs
+++ b/compiler/rustc_target/src/callconv/wasm.rs
@@ -59,7 +59,7 @@ where
 }
 
 /// The purpose of this ABI is to match the C ABI (aka clang) exactly.
-pub(crate) fn compute_c_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
+pub(crate) fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
 where
     Ty: TyAbiInterface<'a, C> + Copy,
     C: HasDataLayout,
@@ -75,43 +75,3 @@ where
         classify_arg(cx, arg);
     }
 }
-
-/// The purpose of this ABI is for matching the WebAssembly standard. This
-/// intentionally diverges from the C ABI and is specifically crafted to take
-/// advantage of LLVM's support of multiple returns in WebAssembly.
-///
-/// This ABI is *bad*! It uses `PassMode::Direct` for `abi::Aggregate` types, which leaks LLVM
-/// implementation details into the ABI. It's just hard to fix because ABIs are hard to change.
-/// Also see <https://github.com/rust-lang/rust/issues/115666>.
-pub(crate) fn compute_wasm_abi_info<Ty>(fn_abi: &mut FnAbi<'_, Ty>) {
-    if !fn_abi.ret.is_ignore() {
-        classify_ret_wasm_abi(&mut fn_abi.ret);
-    }
-
-    for arg in fn_abi.args.iter_mut() {
-        if arg.is_ignore() {
-            continue;
-        }
-        classify_arg_wasm_abi(arg);
-    }
-
-    fn classify_ret_wasm_abi<Ty>(ret: &mut ArgAbi<'_, Ty>) {
-        if !ret.layout.is_sized() {
-            // Not touching this...
-            return;
-        }
-        // FIXME: this is bad! https://github.com/rust-lang/rust/issues/115666
-        ret.make_direct_deprecated();
-        ret.extend_integer_width_to(32);
-    }
-
-    fn classify_arg_wasm_abi<Ty>(arg: &mut ArgAbi<'_, Ty>) {
-        if !arg.layout.is_sized() {
-            // Not touching this...
-            return;
-        }
-        // FIXME: this is bad! https://github.com/rust-lang/rust/issues/115666
-        arg.make_direct_deprecated();
-        arg.extend_integer_width_to(32);
-    }
-}
diff --git a/compiler/rustc_target/src/callconv/x86_64.rs b/compiler/rustc_target/src/callconv/x86_64.rs
index 300b19f62e7..700ee73c8fd 100644
--- a/compiler/rustc_target/src/callconv/x86_64.rs
+++ b/compiler/rustc_target/src/callconv/x86_64.rs
@@ -7,6 +7,7 @@ use rustc_abi::{
 };
 
 use crate::callconv::{ArgAbi, CastTarget, FnAbi};
+use crate::spec::HasTargetSpec;
 
 /// Classification of "eightbyte" components.
 // N.B., the order of the variants is from general to specific,
@@ -175,7 +176,7 @@ const MAX_SSE_REGS: usize = 8; // XMM0-7
 pub(crate) fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
 where
     Ty: TyAbiInterface<'a, C> + Copy,
-    C: HasDataLayout,
+    C: HasDataLayout + HasTargetSpec,
 {
     let mut int_regs = MAX_INT_REGS;
     let mut sse_regs = MAX_SSE_REGS;
@@ -236,7 +237,7 @@ where
                 if arg.layout.is_aggregate() {
                     let size = arg.layout.size;
                     arg.cast_to(cast_target(cls, size));
-                } else {
+                } else if is_arg || cx.target_spec().is_like_darwin {
                     arg.extend_integer_width_to(32);
                 }
             }
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index c360fe63a00..010355abd78 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -2233,22 +2233,6 @@ impl HasTargetSpec for Target {
     }
 }
 
-/// Which C ABI to use for `wasm32-unknown-unknown`.
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-pub enum WasmCAbi {
-    /// Spec-compliant C ABI.
-    Spec,
-    /// Legacy ABI. Which is non-spec-compliant.
-    Legacy {
-        /// Indicates whether the `wasm_c_abi` lint should be emitted.
-        with_lint: bool,
-    },
-}
-
-pub trait HasWasmCAbiOpt {
-    fn wasm_c_abi_opt(&self) -> WasmCAbi;
-}
-
 /// x86 (32-bit) abi options.
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct X86Abi {
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index bb5187e4f5c..f0ff50318ab 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -403,28 +403,18 @@ fn fn_abi_sanity_check<'tcx>(
                         // For an unsized type we'd only pass the sized prefix, so there is no universe
                         // in which we ever want to allow this.
                         assert!(sized, "`PassMode::Direct` for unsized type in ABI: {:#?}", fn_abi);
+
                         // This really shouldn't happen even for sized aggregates, since
                         // `immediate_llvm_type` will use `layout.fields` to turn this Rust type into an
                         // LLVM type. This means all sorts of Rust type details leak into the ABI.
-                        // However wasm sadly *does* currently use this mode for it's "C" ABI so we
-                        // have to allow it -- but we absolutely shouldn't let any more targets do
-                        // that. (Also see <https://github.com/rust-lang/rust/issues/115666>.)
-                        //
-                        // The unadjusted ABI also uses Direct for all args and is ill-specified,
+                        // The unadjusted ABI however uses Direct for all args. It is ill-specified,
                         // but unfortunately we need it for calling certain LLVM intrinsics.
-
-                        match spec_abi {
-                            ExternAbi::Unadjusted => {}
-                            ExternAbi::C { unwind: _ }
-                                if matches!(&*tcx.sess.target.arch, "wasm32" | "wasm64") => {}
-                            _ => {
-                                panic!(
-                                    "`PassMode::Direct` for aggregates only allowed for \"unadjusted\" functions and on wasm\n\
-                                      Problematic type: {:#?}",
-                                    arg.layout,
-                                );
-                            }
-                        }
+                        assert!(
+                            matches!(spec_abi, ExternAbi::Unadjusted),
+                            "`PassMode::Direct` for aggregates only allowed for \"unadjusted\"\n\
+                             Problematic type: {:#?}",
+                            arg.layout,
+                        );
                     }
                 }
             }
diff --git a/compiler/rustc_type_ir/src/search_graph/mod.rs b/compiler/rustc_type_ir/src/search_graph/mod.rs
index f0eb96b47b1..b59b4f92854 100644
--- a/compiler/rustc_type_ir/src/search_graph/mod.rs
+++ b/compiler/rustc_type_ir/src/search_graph/mod.rs
@@ -842,9 +842,8 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
     /// evaluating this entry would not have ended up depending on either a goal
     /// already on the stack or a provisional cache entry.
     fn candidate_is_applicable(
-        stack: &Stack<X>,
+        &self,
         step_kind_from_parent: PathKind,
-        provisional_cache: &HashMap<X::Input, Vec<ProvisionalCacheEntry<X>>>,
         nested_goals: &NestedGoals<X>,
     ) -> bool {
         // If the global cache entry didn't depend on any nested goals, it always
@@ -855,7 +854,7 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
 
         // If a nested goal of the global cache entry is on the stack, we would
         // definitely encounter a cycle.
-        if stack.iter().any(|e| nested_goals.contains(e.input)) {
+        if self.stack.iter().any(|e| nested_goals.contains(e.input)) {
             debug!("cache entry not applicable due to stack");
             return false;
         }
@@ -864,7 +863,7 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
         // would apply for any of its nested goals.
         #[allow(rustc::potential_query_instability)]
         for (input, path_from_global_entry) in nested_goals.iter() {
-            let Some(entries) = provisional_cache.get(&input) else {
+            let Some(entries) = self.provisional_cache.get(&input) else {
                 continue;
             };
 
@@ -890,7 +889,7 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
                 // We check if any of the paths taken while computing the global goal
                 // would end up with an applicable provisional cache entry.
                 let head = heads.highest_cycle_head();
-                let head_to_curr = Self::cycle_path_kind(stack, step_kind_from_parent, head);
+                let head_to_curr = Self::cycle_path_kind(&self.stack, step_kind_from_parent, head);
                 let full_paths = path_from_global_entry.extend_with(head_to_curr);
                 if full_paths.contains(head_to_provisional.into()) {
                     debug!(
@@ -918,12 +917,7 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
         cx.with_global_cache(|cache| {
             cache
                 .get(cx, input, available_depth, |nested_goals| {
-                    Self::candidate_is_applicable(
-                        &self.stack,
-                        step_kind_from_parent,
-                        &self.provisional_cache,
-                        nested_goals,
-                    )
+                    self.candidate_is_applicable(step_kind_from_parent, nested_goals)
                 })
                 .map(|c| c.result)
         })
@@ -942,12 +936,7 @@ impl<D: Delegate<Cx = X>, X: Cx> SearchGraph<D> {
         cx.with_global_cache(|cache| {
             let CacheData { result, required_depth, encountered_overflow, nested_goals } = cache
                 .get(cx, input, available_depth, |nested_goals| {
-                    Self::candidate_is_applicable(
-                        &self.stack,
-                        step_kind_from_parent,
-                        &self.provisional_cache,
-                        nested_goals,
-                    )
+                    self.candidate_is_applicable(step_kind_from_parent, nested_goals)
                 })?;
 
             // We don't move cycle participants to the global cache, so the
diff --git a/compiler/rustc_type_ir/src/solve/mod.rs b/compiler/rustc_type_ir/src/solve/mod.rs
index 2e05c23a645..ba777c7c59a 100644
--- a/compiler/rustc_type_ir/src/solve/mod.rs
+++ b/compiler/rustc_type_ir/src/solve/mod.rs
@@ -236,6 +236,14 @@ pub struct ExternalConstraintsData<I: Interner> {
     pub normalization_nested_goals: NestedNormalizationGoals<I>,
 }
 
+impl<I: Interner> ExternalConstraintsData<I> {
+    pub fn is_empty(&self) -> bool {
+        self.region_constraints.is_empty()
+            && self.opaque_types.is_empty()
+            && self.normalization_nested_goals.is_empty()
+    }
+}
+
 #[derive_where(Clone, Hash, PartialEq, Eq, Debug, Default; I: Interner)]
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
 #[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]