Auto merge of #98123 - JohnTitor:rollup-rfg1a4s, r=JohnTitor

Rollup of 7 pull requests

Successful merges:

 - #97822 (Filter out intrinsics if we have other import candidates to suggest)
 - #98026 (Move some tests to more reasonable directories)
 - #98067 (compiler: remove unused deps)
 - #98078 (Use unchecked mul to compute slice sizes)
 - #98083 (Rename rustc_serialize::opaque::Encoder as MemEncoder.)
 - #98087 (Suggest adding a `#[macro_export]` to a private macro)
 - #98113 (Fix misspelling of "constraint" as "contraint")

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

69 files changed, 322 insertions, 206 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f586e9facc6..b47e8147404 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3678,7 +3678,6 @@ dependencies = [
  "libloading",
  "measureme 10.0.0",
  "rustc-demangle",
- "rustc_arena",
  "rustc_ast",
  "rustc_attr",
  "rustc_codegen_ssa",
@@ -3801,7 +3800,6 @@ dependencies = [
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_codegen_ssa",
- "rustc_const_eval",
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
@@ -3816,7 +3814,6 @@ dependencies = [
  "rustc_parse",
  "rustc_plugin_impl",
  "rustc_save_analysis",
- "rustc_serialize",
  "rustc_session",
  "rustc_span",
  "rustc_target",
@@ -3912,7 +3909,6 @@ dependencies = [
  "rustc_ast",
  "rustc_data_structures",
  "rustc_error_messages",
- "rustc_feature",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
@@ -3973,7 +3969,6 @@ dependencies = [
  "rustc_macros",
  "rustc_middle",
  "rustc_serialize",
- "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec",
@@ -4207,7 +4202,6 @@ dependencies = [
  "rustc_index",
  "rustc_middle",
  "rustc_serialize",
- "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec",
@@ -4229,7 +4223,6 @@ dependencies = [
  "rustc_index",
  "rustc_middle",
  "rustc_mir_dataflow",
- "rustc_query_system",
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
@@ -4244,7 +4237,6 @@ name = "rustc_monomorphize"
 version = "0.0.0"
 dependencies = [
  "rustc_data_structures",
- "rustc_errors",
  "rustc_hir",
  "rustc_index",
  "rustc_middle",
@@ -4296,7 +4288,6 @@ dependencies = [
  "rustc_index",
  "rustc_lexer",
  "rustc_middle",
- "rustc_parse",
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
@@ -4311,10 +4302,8 @@ dependencies = [
  "libloading",
  "rustc_ast",
  "rustc_errors",
- "rustc_hir",
  "rustc_lint",
  "rustc_metadata",
- "rustc_middle",
  "rustc_session",
  "rustc_span",
 ]
@@ -4353,7 +4342,6 @@ dependencies = [
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
- "rustc_type_ir",
  "tracing",
 ]
 
@@ -4375,7 +4363,6 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_target",
- "rustc_type_ir",
  "smallvec",
  "tracing",
 ]
@@ -4495,7 +4482,6 @@ dependencies = [
  "rustc_data_structures",
  "rustc_hir",
  "rustc_middle",
- "rustc_query_system",
  "rustc_session",
  "rustc_span",
  "rustc_target",
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 4e2495ab14c..e5b61d7000a 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -31,7 +31,7 @@ use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::thin_vec::ThinVec;
 use rustc_macros::HashStable_Generic;
-use rustc_serialize::{self, Decoder, Encoder};
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_span::source_map::{respan, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
@@ -2488,11 +2488,11 @@ rustc_index::newtype_index! {
     }
 }
 
-impl<S: Encoder> rustc_serialize::Encodable<S> for AttrId {
+impl<S: Encoder> Encodable<S> for AttrId {
     fn encode(&self, _s: &mut S) {}
 }
 
-impl<D: Decoder> rustc_serialize::Decodable<D> for AttrId {
+impl<D: Decoder> Decodable<D> for AttrId {
     fn decode(_: &mut D) -> AttrId {
         crate::attr::mk_attr_id()
     }
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 6fe95a21fa4..cb7804ca375 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -871,7 +871,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     self.lower_angle_bracketed_parameter_data(data, ParamMode::Explicit, itctx).0
                 }
                 GenericArgs::Parenthesized(ref data) => {
-                    self.assoc_ty_contraint_param_error_emit(data);
+                    self.emit_bad_parenthesized_trait_in_assoc_ty(data);
                     self.lower_angle_bracketed_parameter_data(
                         &data.as_angle_bracketed_args(),
                         ParamMode::Explicit,
@@ -982,7 +982,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         }
     }
 
-    fn assoc_ty_contraint_param_error_emit(&self, data: &ParenthesizedArgs) -> () {
+    fn emit_bad_parenthesized_trait_in_assoc_ty(&self, data: &ParenthesizedArgs) {
         let mut err = self.sess.struct_span_err(
             data.span,
             "parenthesized generic arguments cannot be used in associated type constraints",
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index 9bded25c09e..b486af13376 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -16,7 +16,6 @@ measureme = "10.0.0"
 tracing = "0.1"
 rustc_middle = { path = "../rustc_middle" }
 rustc-demangle = "0.1.21"
-rustc_arena = { path = "../rustc_arena" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
 rustc_symbol_mangling = { path = "../rustc_symbol_mangling" }
diff --git a/compiler/rustc_codegen_ssa/src/glue.rs b/compiler/rustc_codegen_ssa/src/glue.rs
index 694f5434e9a..e6f402ef19d 100644
--- a/compiler/rustc_codegen_ssa/src/glue.rs
+++ b/compiler/rustc_codegen_ssa/src/glue.rs
@@ -39,7 +39,12 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             // The info in this case is the length of the str, so the size is that
             // times the unit size.
             (
-                bx.mul(info.unwrap(), bx.const_usize(unit.size.bytes())),
+                // All slice sizes must fit into `isize`, so this multiplication cannot (signed) wrap.
+                // NOTE: ideally, we want the effects of both `unchecked_smul` and `unchecked_umul`
+                // (resulting in `mul nsw nuw` in LLVM IR), since we know that the multiplication
+                // cannot signed wrap, and that both operands are non-negative. But at the time of writing,
+                // `BuilderMethods` can't do this, and it doesn't seem to enable any further optimizations.
+                bx.unchecked_smul(info.unwrap(), bx.const_usize(unit.size.bytes())),
                 bx.const_usize(unit.align.abi.bytes()),
             )
         }
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
index 771157dcad9..750432b0b26 100644
--- a/compiler/rustc_codegen_ssa/src/lib.rs
+++ b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -29,7 +29,8 @@ use rustc_middle::dep_graph::WorkProduct;
 use rustc_middle::middle::dependency_format::Dependencies;
 use rustc_middle::middle::exported_symbols::SymbolExportKind;
 use rustc_middle::ty::query::{ExternProviders, Providers};
-use rustc_serialize::{opaque, Decodable, Decoder, Encodable, Encoder};
+use rustc_serialize::opaque::{MemDecoder, MemEncoder};
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_session::config::{CrateType, OutputFilenames, OutputType, RUST_CGU_EXT};
 use rustc_session::cstore::{self, CrateSource};
 use rustc_session::utils::NativeLibKind;
@@ -203,7 +204,7 @@ const RUSTC_VERSION: Option<&str> = option_env!("CFG_VERSION");
 
 impl CodegenResults {
     pub fn serialize_rlink(codegen_results: &CodegenResults) -> Vec<u8> {
-        let mut encoder = opaque::Encoder::new();
+        let mut encoder = MemEncoder::new();
         encoder.emit_raw_bytes(RLINK_MAGIC);
         // `emit_raw_bytes` is used to make sure that the version representation does not depend on
         // Encoder's inner representation of `u32`.
@@ -230,7 +231,7 @@ impl CodegenResults {
             return Err(".rlink file was produced with encoding version {version_array}, but the current version is {RLINK_VERSION}".to_string());
         }
 
-        let mut decoder = opaque::Decoder::new(&data[4..], 0);
+        let mut decoder = MemDecoder::new(&data[4..], 0);
         let rustc_version = decoder.read_str();
         let current_version = RUSTC_VERSION.unwrap();
         if rustc_version != current_version {
diff --git a/compiler/rustc_data_structures/src/fingerprint.rs b/compiler/rustc_data_structures/src/fingerprint.rs
index a032b039f34..5ff2d18dd2b 100644
--- a/compiler/rustc_data_structures/src/fingerprint.rs
+++ b/compiler/rustc_data_structures/src/fingerprint.rs
@@ -1,5 +1,5 @@
 use crate::stable_hasher;
-use rustc_serialize::{Decodable, Encodable};
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use std::convert::TryInto;
 use std::hash::{Hash, Hasher};
 
@@ -142,14 +142,14 @@ impl stable_hasher::StableHasherResult for Fingerprint {
 
 impl_stable_hash_via_hash!(Fingerprint);
 
-impl<E: rustc_serialize::Encoder> Encodable<E> for Fingerprint {
+impl<E: Encoder> Encodable<E> for Fingerprint {
     #[inline]
     fn encode(&self, s: &mut E) {
         s.emit_raw_bytes(&self.to_le_bytes());
     }
 }
 
-impl<D: rustc_serialize::Decoder> Decodable<D> for Fingerprint {
+impl<D: Decoder> Decodable<D> for Fingerprint {
     #[inline]
     fn decode(d: &mut D) -> Self {
         Fingerprint::from_le_bytes(d.read_raw_bytes(16).try_into().unwrap())
@@ -184,7 +184,7 @@ impl std::fmt::Display for PackedFingerprint {
     }
 }
 
-impl<E: rustc_serialize::Encoder> Encodable<E> for PackedFingerprint {
+impl<E: Encoder> Encodable<E> for PackedFingerprint {
     #[inline]
     fn encode(&self, s: &mut E) {
         // Copy to avoid taking reference to packed field.
@@ -193,7 +193,7 @@ impl<E: rustc_serialize::Encoder> Encodable<E> for PackedFingerprint {
     }
 }
 
-impl<D: rustc_serialize::Decoder> Decodable<D> for PackedFingerprint {
+impl<D: Decoder> Decodable<D> for PackedFingerprint {
     #[inline]
     fn decode(d: &mut D) -> Self {
         Self(Fingerprint::decode(d))
diff --git a/compiler/rustc_driver/Cargo.toml b/compiler/rustc_driver/Cargo.toml
index a2cbd9abc90..08d5d4f343c 100644
--- a/compiler/rustc_driver/Cargo.toml
+++ b/compiler/rustc_driver/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"
 crate-type = ["dylib"]
 
 [dependencies]
-libc = "0.2"
 tracing = { version = "0.1.28" }
 serde_json = "1.0.59"
 rustc_log = { path = "../rustc_log" }
@@ -21,7 +20,6 @@ rustc_feature = { path = "../rustc_feature" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_metadata = { path = "../rustc_metadata" }
-rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_parse = { path = "../rustc_parse" }
 rustc_plugin_impl = { path = "../rustc_plugin_impl" }
 rustc_save_analysis = { path = "../rustc_save_analysis" }
@@ -29,11 +27,13 @@ rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
 rustc_session = { path = "../rustc_session" }
 rustc_error_codes = { path = "../rustc_error_codes" }
 rustc_interface = { path = "../rustc_interface" }
-rustc_serialize = { path = "../rustc_serialize" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_span = { path = "../rustc_span" }
 rustc_typeck = { path = "../rustc_typeck" }
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["consoleapi", "debugapi", "processenv"] }
 
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 34d366f4013..47ace7ca3a7 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -8,7 +8,6 @@ doctest = false
 
 [dependencies]
 rustc_target = { path = "../rustc_target" }
-rustc_feature = { path = "../rustc_feature" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_messages = { path = "../rustc_error_messages" }
diff --git a/compiler/rustc_incremental/src/persist/load.rs b/compiler/rustc_incremental/src/persist/load.rs
index 9de14950aa8..9c325faae80 100644
--- a/compiler/rustc_incremental/src/persist/load.rs
+++ b/compiler/rustc_incremental/src/persist/load.rs
@@ -4,7 +4,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::memmap::Mmap;
 use rustc_middle::dep_graph::{SerializedDepGraph, WorkProduct, WorkProductId};
 use rustc_middle::ty::OnDiskCache;
-use rustc_serialize::opaque::Decoder;
+use rustc_serialize::opaque::MemDecoder;
 use rustc_serialize::Decodable;
 use rustc_session::config::IncrementalStateAssertion;
 use rustc_session::Session;
@@ -156,7 +156,7 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
 
         if let LoadResult::Ok { data: (work_products_data, start_pos) } = load_result {
             // Decode the list of work_products
-            let mut work_product_decoder = Decoder::new(&work_products_data[..], start_pos);
+            let mut work_product_decoder = MemDecoder::new(&work_products_data[..], start_pos);
             let work_products: Vec<SerializedWorkProduct> =
                 Decodable::decode(&mut work_product_decoder);
 
@@ -193,7 +193,7 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
             LoadResult::DataOutOfDate => LoadResult::DataOutOfDate,
             LoadResult::Error { message } => LoadResult::Error { message },
             LoadResult::Ok { data: (bytes, start_pos) } => {
-                let mut decoder = Decoder::new(&bytes, start_pos);
+                let mut decoder = MemDecoder::new(&bytes, start_pos);
                 let prev_commandline_args_hash = u64::decode(&mut decoder);
 
                 if prev_commandline_args_hash != expected_hash {
diff --git a/compiler/rustc_infer/Cargo.toml b/compiler/rustc_infer/Cargo.toml
index f87ea43b1a7..bbc2b767734 100644
--- a/compiler/rustc_infer/Cargo.toml
+++ b/compiler/rustc_infer/Cargo.toml
@@ -14,7 +14,6 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
-rustc_session = { path = "../rustc_session" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index 47dc5f2ef86..26b1b9948a0 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"
 doctest = false
 
 [dependencies]
-libc = "0.2"
 libloading = "0.7.1"
 tracing = "0.1"
 rustc-rayon-core = { version = "0.4.0", optional = true }
@@ -49,6 +48,9 @@ rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 tempfile = "3.2"
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["libloaderapi"] }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 186031d4586..c1ded99a25a 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -26,7 +26,8 @@ use rustc_middle::ty::codec::TyDecoder;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::GeneratorDiagnosticData;
 use rustc_middle::ty::{self, ParameterizedOverTcx, Ty, TyCtxt, Visibility};
-use rustc_serialize::{opaque, Decodable, Decoder};
+use rustc_serialize::opaque::MemDecoder;
+use rustc_serialize::{Decodable, Decoder};
 use rustc_session::cstore::{
     CrateSource, ExternCrate, ForeignModule, LinkagePreference, NativeLib,
 };
@@ -154,7 +155,7 @@ struct ImportedSourceFile {
 }
 
 pub(super) struct DecodeContext<'a, 'tcx> {
-    opaque: opaque::Decoder<'a>,
+    opaque: MemDecoder<'a>,
     cdata: Option<CrateMetadataRef<'a>>,
     blob: &'a MetadataBlob,
     sess: Option<&'tcx Session>,
@@ -186,7 +187,7 @@ pub(super) trait Metadata<'a, 'tcx>: Copy {
     fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
         let tcx = self.tcx();
         DecodeContext {
-            opaque: opaque::Decoder::new(self.blob(), pos),
+            opaque: MemDecoder::new(self.blob(), pos),
             cdata: self.cdata(),
             blob: self.blob(),
             sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
@@ -418,7 +419,7 @@ impl<'a, 'tcx> TyDecoder for DecodeContext<'a, 'tcx> {
     where
         F: FnOnce(&mut Self) -> R,
     {
-        let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
+        let new_opaque = MemDecoder::new(self.opaque.data, pos);
         let old_opaque = mem::replace(&mut self.opaque, new_opaque);
         let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
         let r = f(self);
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 50c09aaf8d4..26fb2102000 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -27,7 +27,8 @@ use rustc_middle::ty::codec::TyEncoder;
 use rustc_middle::ty::fast_reject::{self, SimplifiedType, TreatParams};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
-use rustc_serialize::{opaque, Encodable, Encoder};
+use rustc_serialize::opaque::MemEncoder;
+use rustc_serialize::{Encodable, Encoder};
 use rustc_session::config::CrateType;
 use rustc_session::cstore::{ForeignModule, LinkagePreference, NativeLib};
 use rustc_span::hygiene::{ExpnIndex, HygieneEncodeContext, MacroKind};
@@ -43,7 +44,7 @@ use std::num::NonZeroUsize;
 use tracing::{debug, trace};
 
 pub(super) struct EncodeContext<'a, 'tcx> {
-    opaque: opaque::Encoder,
+    opaque: MemEncoder,
     tcx: TyCtxt<'tcx>,
     feat: &'tcx rustc_feature::Features,
 
@@ -93,8 +94,8 @@ macro_rules! encoder_methods {
 }
 
 impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
-    type Ok = <opaque::Encoder as Encoder>::Ok;
-    type Err = <opaque::Encoder as Encoder>::Err;
+    type Ok = <MemEncoder as Encoder>::Ok;
+    type Err = <MemEncoder as Encoder>::Err;
 
     encoder_methods! {
         emit_usize(usize);
@@ -2180,7 +2181,7 @@ pub fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
 }
 
 fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata {
-    let mut encoder = opaque::Encoder::new();
+    let mut encoder = MemEncoder::new();
     encoder.emit_raw_bytes(METADATA_HEADER);
 
     // Will be filled with the root position after encoding everything.
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index fb2ffe1d73d..04f0847f5cc 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -22,7 +22,7 @@ use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, ReprOptions, Ty};
 use rustc_middle::ty::{GeneratorDiagnosticData, ParameterizedOverTcx, TyCtxt};
-use rustc_serialize::opaque::Encoder;
+use rustc_serialize::opaque::MemEncoder;
 use rustc_session::config::SymbolManglingVersion;
 use rustc_session::cstore::{CrateDepKind, ForeignModule, LinkagePreference, NativeLib};
 use rustc_span::edition::Edition;
@@ -323,7 +323,7 @@ macro_rules! define_tables {
         }
 
         impl TableBuilders {
-            fn encode(&self, buf: &mut Encoder) -> LazyTables {
+            fn encode(&self, buf: &mut MemEncoder) -> LazyTables {
                 LazyTables {
                     $($name: self.$name.encode(buf)),+
                 }
diff --git a/compiler/rustc_metadata/src/rmeta/table.rs b/compiler/rustc_metadata/src/rmeta/table.rs
index 8baa67a8f9f..5ab4269ae99 100644
--- a/compiler/rustc_metadata/src/rmeta/table.rs
+++ b/compiler/rustc_metadata/src/rmeta/table.rs
@@ -4,8 +4,8 @@ use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_hir::def::{CtorKind, CtorOf};
 use rustc_index::vec::Idx;
 use rustc_middle::ty::ParameterizedOverTcx;
-use rustc_serialize::opaque::Encoder;
-use rustc_serialize::Encoder as _;
+use rustc_serialize::opaque::MemEncoder;
+use rustc_serialize::Encoder;
 use rustc_span::hygiene::MacroKind;
 use std::convert::TryInto;
 use std::marker::PhantomData;
@@ -281,7 +281,7 @@ where
         Some(value).write_to_bytes(&mut self.blocks[i]);
     }
 
-    pub(crate) fn encode<const N: usize>(&self, buf: &mut Encoder) -> LazyTable<I, T>
+    pub(crate) fn encode<const N: usize>(&self, buf: &mut MemEncoder) -> LazyTable<I, T>
     where
         Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
     {
diff --git a/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs b/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs
index 096bf8cbc15..1279f5aee36 100644
--- a/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs
+++ b/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs
@@ -3,7 +3,7 @@ use rustc_data_structures::graph::{
 };
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::OnceCell;
-use rustc_serialize as serialize;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 
 /// Helper type to cache the result of `graph::is_cyclic`.
 #[derive(Clone, Debug)]
@@ -36,17 +36,17 @@ impl GraphIsCyclicCache {
     }
 }
 
-impl<S: serialize::Encoder> serialize::Encodable<S> for GraphIsCyclicCache {
+impl<S: Encoder> Encodable<S> for GraphIsCyclicCache {
     #[inline]
     fn encode(&self, s: &mut S) {
-        serialize::Encodable::encode(&(), s);
+        Encodable::encode(&(), s);
     }
 }
 
-impl<D: serialize::Decoder> serialize::Decodable<D> for GraphIsCyclicCache {
+impl<D: Decoder> Decodable<D> for GraphIsCyclicCache {
     #[inline]
     fn decode(d: &mut D) -> Self {
-        let () = serialize::Decodable::decode(d);
+        let () = Decodable::decode(d);
         Self::new()
     }
 }
diff --git a/compiler/rustc_middle/src/mir/predecessors.rs b/compiler/rustc_middle/src/mir/predecessors.rs
index 9bc0cb1138f..620cf7e336b 100644
--- a/compiler/rustc_middle/src/mir/predecessors.rs
+++ b/compiler/rustc_middle/src/mir/predecessors.rs
@@ -3,7 +3,7 @@
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::OnceCell;
 use rustc_index::vec::IndexVec;
-use rustc_serialize as serialize;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use smallvec::SmallVec;
 
 use crate::mir::{BasicBlock, BasicBlockData};
@@ -54,12 +54,12 @@ impl PredecessorCache {
     }
 }
 
-impl<S: serialize::Encoder> serialize::Encodable<S> for PredecessorCache {
+impl<S: Encoder> Encodable<S> for PredecessorCache {
     #[inline]
     fn encode(&self, _s: &mut S) {}
 }
 
-impl<D: serialize::Decoder> serialize::Decodable<D> for PredecessorCache {
+impl<D: Decoder> Decodable<D> for PredecessorCache {
     #[inline]
     fn decode(_: &mut D) -> Self {
         Self::new()
diff --git a/compiler/rustc_middle/src/mir/switch_sources.rs b/compiler/rustc_middle/src/mir/switch_sources.rs
index 4872a7835e3..99d13fcfef4 100644
--- a/compiler/rustc_middle/src/mir/switch_sources.rs
+++ b/compiler/rustc_middle/src/mir/switch_sources.rs
@@ -5,7 +5,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::stable_map::FxHashMap;
 use rustc_data_structures::sync::OnceCell;
 use rustc_index::vec::IndexVec;
-use rustc_serialize as serialize;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use smallvec::SmallVec;
 
 use crate::mir::{BasicBlock, BasicBlockData, Terminator, TerminatorKind};
@@ -54,12 +54,12 @@ impl SwitchSourceCache {
     }
 }
 
-impl<S: serialize::Encoder> serialize::Encodable<S> for SwitchSourceCache {
+impl<S: Encoder> Encodable<S> for SwitchSourceCache {
     #[inline]
     fn encode(&self, _s: &mut S) {}
 }
 
-impl<D: serialize::Decoder> serialize::Decodable<D> for SwitchSourceCache {
+impl<D: Decoder> Decodable<D> for SwitchSourceCache {
     #[inline]
     fn decode(_: &mut D) -> Self {
         Self::new()
diff --git a/compiler/rustc_middle/src/mir/traversal.rs b/compiler/rustc_middle/src/mir/traversal.rs
index f745e55307a..7228e3f33b1 100644
--- a/compiler/rustc_middle/src/mir/traversal.rs
+++ b/compiler/rustc_middle/src/mir/traversal.rs
@@ -1,7 +1,7 @@
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::OnceCell;
 use rustc_index::bit_set::BitSet;
-use rustc_serialize as serialize;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 
 use super::*;
 
@@ -365,12 +365,12 @@ impl PostorderCache {
     }
 }
 
-impl<S: serialize::Encoder> serialize::Encodable<S> for PostorderCache {
+impl<S: Encoder> Encodable<S> for PostorderCache {
     #[inline]
     fn encode(&self, _s: &mut S) {}
 }
 
-impl<D: serialize::Decoder> serialize::Decodable<D> for PostorderCache {
+impl<D: Decoder> Decodable<D> for PostorderCache {
     #[inline]
     fn decode(_: &mut D) -> Self {
         Self::new()
diff --git a/compiler/rustc_mir_dataflow/Cargo.toml b/compiler/rustc_mir_dataflow/Cargo.toml
index ffd7e3cd06b..a0c70a3fd81 100644
--- a/compiler/rustc_mir_dataflow/Cargo.toml
+++ b/compiler/rustc_mir_dataflow/Cargo.toml
@@ -18,6 +18,5 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_serialize = { path = "../rustc_serialize" }
-rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
 rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_mir_transform/Cargo.toml b/compiler/rustc_mir_transform/Cargo.toml
index 4c1a7eaf6f0..8a8098e9ab9 100644
--- a/compiler/rustc_mir_transform/Cargo.toml
+++ b/compiler/rustc_mir_transform/Cargo.toml
@@ -19,7 +19,6 @@ rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_mir_dataflow = { path = "../rustc_mir_dataflow" }
-rustc_query_system = { path = "../rustc_query_system" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
diff --git a/compiler/rustc_monomorphize/Cargo.toml b/compiler/rustc_monomorphize/Cargo.toml
index f812afe6b62..e4ac47f4982 100644
--- a/compiler/rustc_monomorphize/Cargo.toml
+++ b/compiler/rustc_monomorphize/Cargo.toml
@@ -10,7 +10,6 @@ doctest = false
 smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 rustc_data_structures = { path = "../rustc_data_structures" }
-rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
diff --git a/compiler/rustc_passes/Cargo.toml b/compiler/rustc_passes/Cargo.toml
index a3ef1981e84..787d37277c6 100644
--- a/compiler/rustc_passes/Cargo.toml
+++ b/compiler/rustc_passes/Cargo.toml
@@ -12,7 +12,6 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_expand = { path = "../rustc_expand" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
-rustc_parse = { path = "../rustc_parse" }
 rustc_session = { path = "../rustc_session" }
 rustc_target = { path = "../rustc_target" }
 rustc_ast = { path = "../rustc_ast" }
diff --git a/compiler/rustc_plugin_impl/Cargo.toml b/compiler/rustc_plugin_impl/Cargo.toml
index f5071eb6e8f..b6ea533c80b 100644
--- a/compiler/rustc_plugin_impl/Cargo.toml
+++ b/compiler/rustc_plugin_impl/Cargo.toml
@@ -9,9 +9,7 @@ doctest = false
 
 [dependencies]
 libloading = "0.7.1"
-rustc_middle = { path = "../rustc_middle" }
 rustc_errors = { path = "../rustc_errors" }
-rustc_hir = { path = "../rustc_hir" }
 rustc_lint = { path = "../rustc_lint" }
 rustc_metadata = { path = "../rustc_metadata" }
 rustc_ast = { path = "../rustc_ast" }
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index 856f09b6fcc..5673bb83b15 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -20,7 +20,6 @@ rustc_query_system = { path = "../rustc_query_system" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
-rustc_type_ir = { path = "../rustc_type_ir" }
 tracing = "0.1"
 
 [features]
diff --git a/compiler/rustc_query_impl/src/on_disk_cache.rs b/compiler/rustc_query_impl/src/on_disk_cache.rs
index c2c876f7f1a..d7327ca4bc6 100644
--- a/compiler/rustc_query_impl/src/on_disk_cache.rs
+++ b/compiler/rustc_query_impl/src/on_disk_cache.rs
@@ -15,7 +15,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_query_system::dep_graph::DepContext;
 use rustc_query_system::query::{QueryCache, QueryContext, QuerySideEffects};
 use rustc_serialize::{
-    opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize},
+    opaque::{FileEncodeResult, FileEncoder, IntEncodedWithFixedSize, MemDecoder},
     Decodable, Decoder, Encodable, Encoder,
 };
 use rustc_session::Session;
@@ -158,7 +158,7 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
 
         // Wrap in a scope so we can borrow `data`.
         let footer: Footer = {
-            let mut decoder = opaque::Decoder::new(&data, start_pos);
+            let mut decoder = MemDecoder::new(&data, start_pos);
 
             // Decode the *position* of the footer, which can be found in the
             // last 8 bytes of the file.
@@ -437,7 +437,7 @@ impl<'sess> OnDiskCache<'sess> {
         let serialized_data = self.serialized_data.read();
         let mut decoder = CacheDecoder {
             tcx,
-            opaque: opaque::Decoder::new(serialized_data.as_deref().unwrap_or(&[]), pos.to_usize()),
+            opaque: MemDecoder::new(serialized_data.as_deref().unwrap_or(&[]), pos.to_usize()),
             source_map: self.source_map,
             file_index_to_file: &self.file_index_to_file,
             file_index_to_stable_id: &self.file_index_to_stable_id,
@@ -458,7 +458,7 @@ impl<'sess> OnDiskCache<'sess> {
 /// will also handle things that contain `Ty` instances.
 pub struct CacheDecoder<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    opaque: opaque::Decoder<'a>,
+    opaque: MemDecoder<'a>,
     source_map: &'a SourceMap,
     file_index_to_file: &'a Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
     file_index_to_stable_id: &'a FxHashMap<SourceFileIndex, EncodedSourceFileId>,
@@ -510,7 +510,7 @@ trait DecoderWithPosition: Decoder {
     fn position(&self) -> usize;
 }
 
-impl<'a> DecoderWithPosition for opaque::Decoder<'a> {
+impl<'a> DecoderWithPosition for MemDecoder<'a> {
     fn position(&self) -> usize {
         self.position()
     }
@@ -586,7 +586,7 @@ impl<'a, 'tcx> TyDecoder for CacheDecoder<'a, 'tcx> {
     {
         debug_assert!(pos < self.opaque.data.len());
 
-        let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
+        let new_opaque = MemDecoder::new(self.opaque.data, pos);
         let old_opaque = mem::replace(&mut self.opaque, new_opaque);
         let r = f(self);
         self.opaque = old_opaque;
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index 85fbb08eeeb..b5a37cf324b 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -21,7 +21,6 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
-rustc_type_ir = { path = "../rustc_type_ir" }
 parking_lot = "0.11"
 smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
 
diff --git a/compiler/rustc_query_system/src/dep_graph/serialized.rs b/compiler/rustc_query_system/src/dep_graph/serialized.rs
index 7fde9c0119b..d583b45698a 100644
--- a/compiler/rustc_query_system/src/dep_graph/serialized.rs
+++ b/compiler/rustc_query_system/src/dep_graph/serialized.rs
@@ -19,7 +19,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::sync::Lock;
 use rustc_index::vec::{Idx, IndexVec};
-use rustc_serialize::opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize};
+use rustc_serialize::opaque::{FileEncodeResult, FileEncoder, IntEncodedWithFixedSize, MemDecoder};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use smallvec::SmallVec;
 use std::convert::TryInto;
@@ -96,11 +96,11 @@ impl<K: DepKind> SerializedDepGraph<K> {
     }
 }
 
-impl<'a, K: DepKind + Decodable<opaque::Decoder<'a>>> Decodable<opaque::Decoder<'a>>
+impl<'a, K: DepKind + Decodable<MemDecoder<'a>>> Decodable<MemDecoder<'a>>
     for SerializedDepGraph<K>
 {
     #[instrument(level = "debug", skip(d))]
-    fn decode(d: &mut opaque::Decoder<'a>) -> SerializedDepGraph<K> {
+    fn decode(d: &mut MemDecoder<'a>) -> SerializedDepGraph<K> {
         let start_position = d.position();
 
         // The last 16 bytes are the node count and edge count.
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index f8fa7a0941d..b0e7679af97 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -10,7 +10,9 @@ use crate::imports::{Import, ImportKind};
 use crate::macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
 use crate::Namespace::{self, MacroNS, TypeNS, ValueNS};
 use crate::{Determinacy, ExternPreludeEntry, Finalize, Module, ModuleKind, ModuleOrUniformRoot};
-use crate::{NameBinding, NameBindingKind, ParentScope, PathResult, PerNS, ResolutionError};
+use crate::{
+    MacroData, NameBinding, NameBindingKind, ParentScope, PathResult, PerNS, ResolutionError,
+};
 use crate::{Resolver, ResolverArenas, Segment, ToNameBinding, VisResolutionError};
 
 use rustc_ast::visit::{self, AssocCtxt, Visitor};
@@ -20,7 +22,6 @@ use rustc_ast_lowering::ResolverAstLowering;
 use rustc_attr as attr;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{struct_span_err, Applicability};
-use rustc_expand::base::SyntaxExtension;
 use rustc_expand::expand::AstFragment;
 use rustc_hir::def::{self, *};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
@@ -180,26 +181,32 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    pub(crate) fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
+    pub(crate) fn get_macro(&mut self, res: Res) -> Option<MacroData> {
         match res {
             Res::Def(DefKind::Macro(..), def_id) => Some(self.get_macro_by_def_id(def_id)),
-            Res::NonMacroAttr(_) => Some(self.non_macro_attr.clone()),
+            Res::NonMacroAttr(_) => {
+                Some(MacroData { ext: self.non_macro_attr.clone(), macro_rules: false })
+            }
             _ => None,
         }
     }
 
-    pub(crate) fn get_macro_by_def_id(&mut self, def_id: DefId) -> Lrc<SyntaxExtension> {
-        if let Some(ext) = self.macro_map.get(&def_id) {
-            return ext.clone();
+    pub(crate) fn get_macro_by_def_id(&mut self, def_id: DefId) -> MacroData {
+        if let Some(macro_data) = self.macro_map.get(&def_id) {
+            return macro_data.clone();
         }
 
-        let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
-            LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition).0,
-            LoadedMacro::ProcMacro(ext) => ext,
-        });
+        let (ext, macro_rules) = match self.cstore().load_macro_untracked(def_id, &self.session) {
+            LoadedMacro::MacroDef(item, edition) => (
+                Lrc::new(self.compile_macro(&item, edition).0),
+                matches!(item.kind, ItemKind::MacroDef(def) if def.macro_rules),
+            ),
+            LoadedMacro::ProcMacro(extz) => (Lrc::new(extz), false),
+        };
 
-        self.macro_map.insert(def_id, ext.clone());
-        ext
+        let macro_data = MacroData { ext, macro_rules };
+        self.macro_map.insert(def_id, macro_data.clone());
+        macro_data
     }
 
     pub(crate) fn build_reduced_graph(
@@ -1251,7 +1258,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         };
 
         let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id.to_def_id());
-        self.r.macro_map.insert(def_id.to_def_id(), ext);
+        self.r.macro_map.insert(def_id.to_def_id(), MacroData { ext, macro_rules });
         self.r.local_macro_def_scopes.insert(def_id, parent_scope.module);
 
         if macro_rules {
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index b25393c3ed8..e934e189f05 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -241,7 +241,7 @@ impl<'a> Resolver<'a> {
                 {
                     // The macro is a proc macro derive
                     if let Some(def_id) = module.expansion.expn_data().macro_def_id {
-                        let ext = self.get_macro_by_def_id(def_id);
+                        let ext = self.get_macro_by_def_id(def_id).ext;
                         if ext.builtin_name.is_none()
                             && ext.macro_kind() == MacroKind::Derive
                             && parent.expansion.outer_expn_is_descendant_of(*ctxt)
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index de83a3a5932..c6aa57f039d 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -12,7 +12,7 @@ use rustc_ast::NodeId;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::intern::Interned;
 use rustc_errors::{pluralize, struct_span_err, Applicability, MultiSpan};
-use rustc_hir::def::{self, PartialRes};
+use rustc_hir::def::{self, DefKind, PartialRes};
 use rustc_middle::metadata::ModChild;
 use rustc_middle::span_bug;
 use rustc_middle::ty;
@@ -922,11 +922,28 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                         .note(&format!("consider declaring type or module `{}` with `pub`", ident))
                         .emit();
                 } else {
-                    let note_msg =
-                        format!("consider marking `{}` as `pub` in the imported module", ident);
-                    struct_span_err!(self.r.session, import.span, E0364, "{}", error_msg)
-                        .span_note(import.span, &note_msg)
-                        .emit();
+                    let mut err =
+                        struct_span_err!(self.r.session, import.span, E0364, "{error_msg}");
+                    match binding.kind {
+                        NameBindingKind::Res(Res::Def(DefKind::Macro(_), def_id), _)
+                            // exclude decl_macro
+                            if self.r.get_macro_by_def_id(def_id).macro_rules =>
+                        {
+                            err.span_help(
+                                binding.span,
+                                "consider adding a `#[macro_export]` to the macro in the imported module",
+                            );
+                        }
+                        _ => {
+                            err.span_note(
+                                import.span,
+                                &format!(
+                                    "consider marking `{ident}` as `pub` in the imported module"
+                                ),
+                            );
+                        }
+                    }
+                    err.emit();
                 }
             }
         }
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index d2306254e31..460d505ba98 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -396,7 +396,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
 
         // Try to lookup name in more relaxed fashion for better error reporting.
         let ident = path.last().unwrap().ident;
-        let candidates = self
+        let mut candidates = self
             .r
             .lookup_import_candidates(ident, ns, &self.parent_scope, is_expected)
             .into_iter()
@@ -408,6 +408,18 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             })
             .collect::<Vec<_>>();
         let crate_def_id = CRATE_DEF_ID.to_def_id();
+        // Try to filter out intrinsics candidates, as long as we have
+        // some other candidates to suggest.
+        let intrinsic_candidates: Vec<_> = candidates
+            .drain_filter(|sugg| {
+                let path = path_names_to_string(&sugg.path);
+                path.starts_with("core::intrinsics::") || path.starts_with("std::intrinsics::")
+            })
+            .collect();
+        if candidates.is_empty() {
+            // Put them back if we have no more candidates to suggest...
+            candidates.extend(intrinsic_candidates);
+        }
         if candidates.is_empty() && is_expected(Res::Def(DefKind::Enum, crate_def_id)) {
             let mut enum_candidates: Vec<_> = self
                 .r
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 92a65fe249f..ac4e23cc04d 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -866,6 +866,12 @@ struct DeriveData {
     has_derive_copy: bool,
 }
 
+#[derive(Clone)]
+struct MacroData {
+    ext: Lrc<SyntaxExtension>,
+    macro_rules: bool,
+}
+
 /// The main resolver class.
 ///
 /// This is the visitor that walks the whole crate.
@@ -965,7 +971,7 @@ pub struct Resolver<'a> {
     registered_attrs: FxHashSet<Ident>,
     registered_tools: RegisteredTools,
     macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
-    macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
+    macro_map: FxHashMap<DefId, MacroData>,
     dummy_ext_bang: Lrc<SyntaxExtension>,
     dummy_ext_derive: Lrc<SyntaxExtension>,
     non_macro_attr: Lrc<SyntaxExtension>,
@@ -1522,7 +1528,7 @@ impl<'a> Resolver<'a> {
     }
 
     fn is_builtin_macro(&mut self, res: Res) -> bool {
-        self.get_macro(res).map_or(false, |ext| ext.builtin_name.is_some())
+        self.get_macro(res).map_or(false, |macro_data| macro_data.ext.builtin_name.is_some())
     }
 
     fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index 3fb34cdcd9b..c86c2280d19 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -658,7 +658,7 @@ impl<'a> Resolver<'a> {
             res
         };
 
-        res.map(|res| (self.get_macro(res), res))
+        res.map(|res| (self.get_macro(res).map(|macro_data| macro_data.ext), res))
     }
 
     pub(crate) fn finalize_macro_resolutions(&mut self) {
@@ -853,7 +853,7 @@ impl<'a> Resolver<'a> {
         // Reserve some names that are not quite covered by the general check
         // performed on `Resolver::builtin_attrs`.
         if ident.name == sym::cfg || ident.name == sym::cfg_attr {
-            let macro_kind = self.get_macro(res).map(|ext| ext.macro_kind());
+            let macro_kind = self.get_macro(res).map(|macro_data| macro_data.ext.macro_kind());
             if macro_kind.is_some() && sub_namespace_match(macro_kind, Some(MacroKind::Attr)) {
                 self.session.span_err(
                     ident.span,
diff --git a/compiler/rustc_serialize/src/opaque.rs b/compiler/rustc_serialize/src/opaque.rs
index b2dbf937eb7..f828c0b7106 100644
--- a/compiler/rustc_serialize/src/opaque.rs
+++ b/compiler/rustc_serialize/src/opaque.rs
@@ -1,5 +1,5 @@
 use crate::leb128::{self, max_leb128_len};
-use crate::serialize::{self, Decoder as _, Encoder as _};
+use crate::serialize::{Decodable, Decoder, Encodable, Encoder};
 use std::convert::TryInto;
 use std::fs::File;
 use std::io::{self, Write};
@@ -11,13 +11,13 @@ use std::ptr;
 // Encoder
 // -----------------------------------------------------------------------------
 
-pub struct Encoder {
+pub struct MemEncoder {
     pub data: Vec<u8>,
 }
 
-impl Encoder {
-    pub fn new() -> Encoder {
-        Encoder { data: vec![] }
+impl MemEncoder {
+    pub fn new() -> MemEncoder {
+        MemEncoder { data: vec![] }
     }
 
     #[inline]
@@ -53,7 +53,7 @@ macro_rules! write_leb128 {
 /// [utf8]: https://en.wikipedia.org/w/index.php?title=UTF-8&oldid=1058865525#Codepage_layout
 const STR_SENTINEL: u8 = 0xC1;
 
-impl serialize::Encoder for Encoder {
+impl Encoder for MemEncoder {
     type Ok = Vec<u8>;
     type Err = !;
 
@@ -161,7 +161,7 @@ pub type FileEncodeResult = Result<usize, io::Error>;
 // `FileEncoder` encodes data to file via fixed-size buffer.
 //
 // When encoding large amounts of data to a file, using `FileEncoder` may be
-// preferred over using `Encoder` to encode to a `Vec`, and then writing the
+// preferred over using `MemEncoder` to encode to a `Vec`, and then writing the
 // `Vec` to file, as the latter uses as much memory as there is encoded data,
 // while the former uses the fixed amount of memory allocated to the buffer.
 // `FileEncoder` also has the advantage of not needing to reallocate as data
@@ -425,7 +425,7 @@ macro_rules! file_encoder_write_leb128 {
     }};
 }
 
-impl serialize::Encoder for FileEncoder {
+impl Encoder for FileEncoder {
     type Ok = usize;
     type Err = io::Error;
 
@@ -535,15 +535,15 @@ impl serialize::Encoder for FileEncoder {
 // Decoder
 // -----------------------------------------------------------------------------
 
-pub struct Decoder<'a> {
+pub struct MemDecoder<'a> {
     pub data: &'a [u8],
     position: usize,
 }
 
-impl<'a> Decoder<'a> {
+impl<'a> MemDecoder<'a> {
     #[inline]
-    pub fn new(data: &'a [u8], position: usize) -> Decoder<'a> {
-        Decoder { data, position }
+    pub fn new(data: &'a [u8], position: usize) -> MemDecoder<'a> {
+        MemDecoder { data, position }
     }
 
     #[inline]
@@ -566,7 +566,7 @@ macro_rules! read_leb128 {
     ($dec:expr, $fun:ident) => {{ leb128::$fun($dec.data, &mut $dec.position) }};
 }
 
-impl<'a> serialize::Decoder for Decoder<'a> {
+impl<'a> Decoder for MemDecoder<'a> {
     #[inline]
     fn read_u128(&mut self) -> u128 {
         read_leb128!(self, read_u128_leb128)
@@ -688,25 +688,25 @@ impl<'a> serialize::Decoder for Decoder<'a> {
 
 // Specialize encoding byte slices. This specialization also applies to encoding `Vec<u8>`s, etc.,
 // since the default implementations call `encode` on their slices internally.
-impl serialize::Encodable<Encoder> for [u8] {
-    fn encode(&self, e: &mut Encoder) {
-        serialize::Encoder::emit_usize(e, self.len());
+impl Encodable<MemEncoder> for [u8] {
+    fn encode(&self, e: &mut MemEncoder) {
+        Encoder::emit_usize(e, self.len());
         e.emit_raw_bytes(self);
     }
 }
 
-impl serialize::Encodable<FileEncoder> for [u8] {
+impl Encodable<FileEncoder> for [u8] {
     fn encode(&self, e: &mut FileEncoder) {
-        serialize::Encoder::emit_usize(e, self.len());
+        Encoder::emit_usize(e, self.len());
         e.emit_raw_bytes(self);
     }
 }
 
 // Specialize decoding `Vec<u8>`. This specialization also applies to decoding `Box<[u8]>`s, etc.,
 // since the default implementations call `decode` to produce a `Vec<u8>` internally.
-impl<'a> serialize::Decodable<Decoder<'a>> for Vec<u8> {
-    fn decode(d: &mut Decoder<'a>) -> Self {
-        let len = serialize::Decoder::read_usize(d);
+impl<'a> Decodable<MemDecoder<'a>> for Vec<u8> {
+    fn decode(d: &mut MemDecoder<'a>) -> Self {
+        let len = Decoder::read_usize(d);
         d.read_raw_bytes(len).to_owned()
     }
 }
@@ -718,9 +718,9 @@ impl IntEncodedWithFixedSize {
     pub const ENCODED_SIZE: usize = 8;
 }
 
-impl serialize::Encodable<Encoder> for IntEncodedWithFixedSize {
+impl Encodable<MemEncoder> for IntEncodedWithFixedSize {
     #[inline]
-    fn encode(&self, e: &mut Encoder) {
+    fn encode(&self, e: &mut MemEncoder) {
         let _start_pos = e.position();
         e.emit_raw_bytes(&self.0.to_le_bytes());
         let _end_pos = e.position();
@@ -728,7 +728,7 @@ impl serialize::Encodable<Encoder> for IntEncodedWithFixedSize {
     }
 }
 
-impl serialize::Encodable<FileEncoder> for IntEncodedWithFixedSize {
+impl Encodable<FileEncoder> for IntEncodedWithFixedSize {
     #[inline]
     fn encode(&self, e: &mut FileEncoder) {
         let _start_pos = e.position();
@@ -738,9 +738,9 @@ impl serialize::Encodable<FileEncoder> for IntEncodedWithFixedSize {
     }
 }
 
-impl<'a> serialize::Decodable<Decoder<'a>> for IntEncodedWithFixedSize {
+impl<'a> Decodable<MemDecoder<'a>> for IntEncodedWithFixedSize {
     #[inline]
-    fn decode(decoder: &mut Decoder<'a>) -> IntEncodedWithFixedSize {
+    fn decode(decoder: &mut MemDecoder<'a>) -> IntEncodedWithFixedSize {
         let _start_pos = decoder.position();
         let bytes = decoder.read_raw_bytes(IntEncodedWithFixedSize::ENCODED_SIZE);
         let value = u64::from_le_bytes(bytes.try_into().unwrap());
diff --git a/compiler/rustc_serialize/tests/opaque.rs b/compiler/rustc_serialize/tests/opaque.rs
index 703b7f5e7a5..4eafb6fabde 100644
--- a/compiler/rustc_serialize/tests/opaque.rs
+++ b/compiler/rustc_serialize/tests/opaque.rs
@@ -1,7 +1,7 @@
 #![allow(rustc::internal)]
 
 use rustc_macros::{Decodable, Encodable};
-use rustc_serialize::opaque::{Decoder, Encoder};
+use rustc_serialize::opaque::{MemDecoder, MemEncoder};
 use rustc_serialize::{Decodable, Encodable, Encoder as EncoderTrait};
 use std::fmt::Debug;
 
@@ -28,16 +28,18 @@ struct Struct {
     q: Option<u32>,
 }
 
-fn check_round_trip<T: Encodable<Encoder> + for<'a> Decodable<Decoder<'a>> + PartialEq + Debug>(
+fn check_round_trip<
+    T: Encodable<MemEncoder> + for<'a> Decodable<MemDecoder<'a>> + PartialEq + Debug,
+>(
     values: Vec<T>,
 ) {
-    let mut encoder = Encoder::new();
+    let mut encoder = MemEncoder::new();
     for value in &values {
         Encodable::encode(value, &mut encoder);
     }
 
     let data = encoder.finish().unwrap();
-    let mut decoder = Decoder::new(&data[..], 0);
+    let mut decoder = MemDecoder::new(&data[..], 0);
 
     for value in values {
         let decoded = Decodable::decode(&mut decoder);
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index d7e2f621065..5d3d56b1e66 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -1911,13 +1911,13 @@ impl_pos! {
     pub struct CharPos(pub usize);
 }
 
-impl<S: rustc_serialize::Encoder> Encodable<S> for BytePos {
+impl<S: Encoder> Encodable<S> for BytePos {
     fn encode(&self, s: &mut S) {
         s.emit_u32(self.0);
     }
 }
 
-impl<D: rustc_serialize::Decoder> Decodable<D> for BytePos {
+impl<D: Decoder> Decodable<D> for BytePos {
     fn decode(d: &mut D) -> BytePos {
         BytePos(d.read_u32())
     }
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index b9751f0adb5..d5befa10e23 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -16,5 +16,4 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_target = { path = "../rustc_target" }
 rustc_data_structures = { path = "../rustc_data_structures" }
-rustc_query_system = { path = "../rustc_query_system" }
 rustc_session = { path = "../rustc_session" }
diff --git a/compiler/rustc_type_ir/src/sty.rs b/compiler/rustc_type_ir/src/sty.rs
index a6a0d02c8ba..94072184399 100644
--- a/compiler/rustc_type_ir/src/sty.rs
+++ b/compiler/rustc_type_ir/src/sty.rs
@@ -14,7 +14,7 @@ use crate::UintTy;
 use self::TyKind::*;
 
 use rustc_data_structures::stable_hasher::HashStable;
-use rustc_serialize::{Decodable, Encodable};
+use rustc_serialize::{Decodable, Decoder, Encodable};
 
 /// Defines the kinds of types used by the type system.
 ///
@@ -833,56 +833,34 @@ where
     I::AllocId: Decodable<D>,
 {
     fn decode(d: &mut D) -> Self {
-        match rustc_serialize::Decoder::read_usize(d) {
+        match Decoder::read_usize(d) {
             0 => Bool,
             1 => Char,
-            2 => Int(rustc_serialize::Decodable::decode(d)),
-            3 => Uint(rustc_serialize::Decodable::decode(d)),
-            4 => Float(rustc_serialize::Decodable::decode(d)),
-            5 => Adt(rustc_serialize::Decodable::decode(d), rustc_serialize::Decodable::decode(d)),
-            6 => Foreign(rustc_serialize::Decodable::decode(d)),
+            2 => Int(Decodable::decode(d)),
+            3 => Uint(Decodable::decode(d)),
+            4 => Float(Decodable::decode(d)),
+            5 => Adt(Decodable::decode(d), Decodable::decode(d)),
+            6 => Foreign(Decodable::decode(d)),
             7 => Str,
-            8 => {
-                Array(rustc_serialize::Decodable::decode(d), rustc_serialize::Decodable::decode(d))
-            }
-            9 => Slice(rustc_serialize::Decodable::decode(d)),
-            10 => RawPtr(rustc_serialize::Decodable::decode(d)),
-            11 => Ref(
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-            ),
-            12 => {
-                FnDef(rustc_serialize::Decodable::decode(d), rustc_serialize::Decodable::decode(d))
-            }
-            13 => FnPtr(rustc_serialize::Decodable::decode(d)),
-            14 => Dynamic(
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-            ),
-            15 => Closure(
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-            ),
-            16 => Generator(
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-                rustc_serialize::Decodable::decode(d),
-            ),
-            17 => GeneratorWitness(rustc_serialize::Decodable::decode(d)),
+            8 => Array(Decodable::decode(d), Decodable::decode(d)),
+            9 => Slice(Decodable::decode(d)),
+            10 => RawPtr(Decodable::decode(d)),
+            11 => Ref(Decodable::decode(d), Decodable::decode(d), Decodable::decode(d)),
+            12 => FnDef(Decodable::decode(d), Decodable::decode(d)),
+            13 => FnPtr(Decodable::decode(d)),
+            14 => Dynamic(Decodable::decode(d), Decodable::decode(d)),
+            15 => Closure(Decodable::decode(d), Decodable::decode(d)),
+            16 => Generator(Decodable::decode(d), Decodable::decode(d), Decodable::decode(d)),
+            17 => GeneratorWitness(Decodable::decode(d)),
             18 => Never,
-            19 => Tuple(rustc_serialize::Decodable::decode(d)),
-            20 => Projection(rustc_serialize::Decodable::decode(d)),
-            21 => {
-                Opaque(rustc_serialize::Decodable::decode(d), rustc_serialize::Decodable::decode(d))
-            }
-            22 => Param(rustc_serialize::Decodable::decode(d)),
-            23 => {
-                Bound(rustc_serialize::Decodable::decode(d), rustc_serialize::Decodable::decode(d))
-            }
-            24 => Placeholder(rustc_serialize::Decodable::decode(d)),
-            25 => Infer(rustc_serialize::Decodable::decode(d)),
-            26 => Error(rustc_serialize::Decodable::decode(d)),
+            19 => Tuple(Decodable::decode(d)),
+            20 => Projection(Decodable::decode(d)),
+            21 => Opaque(Decodable::decode(d), Decodable::decode(d)),
+            22 => Param(Decodable::decode(d)),
+            23 => Bound(Decodable::decode(d), Decodable::decode(d)),
+            24 => Placeholder(Decodable::decode(d)),
+            25 => Infer(Decodable::decode(d)),
+            26 => Error(Decodable::decode(d)),
             _ => panic!(
                 "{}",
                 format!(
diff --git a/src/librustdoc/scrape_examples.rs b/src/librustdoc/scrape_examples.rs
index 242f926967c..da09ae9dd06 100644
--- a/src/librustdoc/scrape_examples.rs
+++ b/src/librustdoc/scrape_examples.rs
@@ -17,7 +17,7 @@ use rustc_middle::hir::map::Map;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_serialize::{
-    opaque::{Decoder, FileEncoder},
+    opaque::{FileEncoder, MemDecoder},
     Decodable, Encodable, Encoder,
 };
 use rustc_session::getopts;
@@ -336,7 +336,7 @@ pub(crate) fn load_call_locations(
         let mut all_calls: AllCallLocations = FxHashMap::default();
         for path in with_examples {
             let bytes = fs::read(&path).map_err(|e| format!("{} (for path {})", e, path))?;
-            let mut decoder = Decoder::new(&bytes, 0);
+            let mut decoder = MemDecoder::new(&bytes, 0);
             let calls = AllCallLocations::decode(&mut decoder);
 
             for (function, fn_calls) in calls.into_iter() {
diff --git a/src/test/codegen/issue-96497-slice-size-nowrap.rs b/src/test/codegen/issue-96497-slice-size-nowrap.rs
new file mode 100644
index 00000000000..a5dbef93460
--- /dev/null
+++ b/src/test/codegen/issue-96497-slice-size-nowrap.rs
@@ -0,0 +1,29 @@
+// This test case checks that LLVM is aware that computing the size of a slice cannot wrap.
+// The possibility of wrapping results in an additional branch when dropping boxed slices
+// in some situations, see https://github.com/rust-lang/rust/issues/96497#issuecomment-1112865218
+
+// compile-flags: -O
+// min-llvm-version: 14.0
+
+#![crate_type="lib"]
+
+// CHECK-LABEL: @simple_size_of_nowrap
+#[no_mangle]
+pub fn simple_size_of_nowrap(x: &[u32]) -> usize {
+    // Make sure the shift used to compute the size has a nowrap flag.
+
+    // CHECK: [[A:%.*]] = shl nsw {{.*}}, 2
+    // CHECK-NEXT: ret {{.*}} [[A]]
+    core::mem::size_of_val(x)
+}
+
+// CHECK-LABEL: @drop_write
+#[no_mangle]
+pub fn drop_write(mut x: Box<[u32]>) {
+    // Check that this write is optimized out.
+    // This depends on the size calculation not wrapping,
+    // since otherwise LLVM can't tell that the memory is always deallocated if the slice len > 0.
+
+    // CHECK-NOT: store i32 42
+    x[1] = 42;
+}
diff --git a/src/test/ui-fulldeps/deriving-encodable-decodable-box.rs b/src/test/ui-fulldeps/deriving-encodable-decodable-box.rs
index a09deeec4f1..4ad4ef60a52 100644
--- a/src/test/ui-fulldeps/deriving-encodable-decodable-box.rs
+++ b/src/test/ui-fulldeps/deriving-encodable-decodable-box.rs
@@ -7,7 +7,7 @@ extern crate rustc_macros;
 extern crate rustc_serialize;
 
 use rustc_macros::{Decodable, Encodable};
-use rustc_serialize::opaque;
+use rustc_serialize::opaque::{MemDecoder, MemEncoder};
 use rustc_serialize::{Decodable, Encodable, Encoder};
 
 #[derive(Encodable, Decodable)]
@@ -18,11 +18,11 @@ struct A {
 fn main() {
     let obj = A { foo: Box::new([true, false]) };
 
-    let mut encoder = opaque::Encoder::new();
+    let mut encoder = MemEncoder::new();
     obj.encode(&mut encoder);
     let data = encoder.finish().unwrap();
 
-    let mut decoder = opaque::Decoder::new(&data, 0);
+    let mut decoder = MemDecoder::new(&data, 0);
     let obj2 = A::decode(&mut decoder);
 
     assert_eq!(obj.foo, obj2.foo);
diff --git a/src/test/ui-fulldeps/deriving-encodable-decodable-cell-refcell.rs b/src/test/ui-fulldeps/deriving-encodable-decodable-cell-refcell.rs
index 9b6fb0e5806..3ac3abae692 100644
--- a/src/test/ui-fulldeps/deriving-encodable-decodable-cell-refcell.rs
+++ b/src/test/ui-fulldeps/deriving-encodable-decodable-cell-refcell.rs
@@ -9,7 +9,7 @@ extern crate rustc_macros;
 extern crate rustc_serialize;
 
 use rustc_macros::{Decodable, Encodable};
-use rustc_serialize::opaque;
+use rustc_serialize::opaque::{MemDecoder, MemEncoder};
 use rustc_serialize::{Decodable, Encodable, Encoder};
 use std::cell::{Cell, RefCell};
 
@@ -27,11 +27,11 @@ struct B {
 fn main() {
     let obj = B { foo: Cell::new(true), bar: RefCell::new(A { baz: 2 }) };
 
-    let mut encoder = opaque::Encoder::new();
+    let mut encoder = MemEncoder::new();
     obj.encode(&mut encoder);
     let data = encoder.finish().unwrap();
 
-    let mut decoder = opaque::Decoder::new(&data, 0);
+    let mut decoder = MemDecoder::new(&data, 0);
     let obj2 = B::decode(&mut decoder);
 
     assert_eq!(obj.foo.get(), obj2.foo.get());
diff --git a/src/test/ui-fulldeps/issue-14021.rs b/src/test/ui-fulldeps/issue-14021.rs
index 4241456367e..b7b6e1b860d 100644
--- a/src/test/ui-fulldeps/issue-14021.rs
+++ b/src/test/ui-fulldeps/issue-14021.rs
@@ -8,7 +8,7 @@ extern crate rustc_macros;
 extern crate rustc_serialize;
 
 use rustc_macros::{Decodable, Encodable};
-use rustc_serialize::opaque;
+use rustc_serialize::opaque::{MemDecoder, MemEncoder};
 use rustc_serialize::{Decodable, Encodable, Encoder};
 
 #[derive(Encodable, Decodable, PartialEq, Debug)]
@@ -17,11 +17,11 @@ struct UnitLikeStruct;
 pub fn main() {
     let obj = UnitLikeStruct;
 
-    let mut encoder = opaque::Encoder::new();
+    let mut encoder = MemEncoder::new();
     obj.encode(&mut encoder);
     let data = encoder.finish().unwrap();
 
-    let mut decoder = opaque::Decoder::new(&data, 0);
+    let mut decoder = MemDecoder::new(&data, 0);
     let obj2 = UnitLikeStruct::decode(&mut decoder);
 
     assert_eq!(obj, obj2);
diff --git a/src/test/ui/issues/issue-39974.rs b/src/test/ui/consts/issue-39974.rs
index 503647ef4a8..503647ef4a8 100644
--- a/src/test/ui/issues/issue-39974.rs
+++ b/src/test/ui/consts/issue-39974.rs
diff --git a/src/test/ui/issues/issue-39974.stderr b/src/test/ui/consts/issue-39974.stderr
index 56365e51e0a..56365e51e0a 100644
--- a/src/test/ui/issues/issue-39974.stderr
+++ b/src/test/ui/consts/issue-39974.stderr
diff --git a/src/test/ui/issues/issue-17728.rs b/src/test/ui/lifetimes/issue-17728.rs
index 6aca159c47e..6aca159c47e 100644
--- a/src/test/ui/issues/issue-17728.rs
+++ b/src/test/ui/lifetimes/issue-17728.rs
diff --git a/src/test/ui/issues/issue-17728.stderr b/src/test/ui/lifetimes/issue-17728.stderr
index 3b25902d757..3b25902d757 100644
--- a/src/test/ui/issues/issue-17728.stderr
+++ b/src/test/ui/lifetimes/issue-17728.stderr
diff --git a/src/test/ui/issues/issue-55796.rs b/src/test/ui/lifetimes/issue-55796.rs
index a7b27a99929..a7b27a99929 100644
--- a/src/test/ui/issues/issue-55796.rs
+++ b/src/test/ui/lifetimes/issue-55796.rs
diff --git a/src/test/ui/issues/issue-55796.stderr b/src/test/ui/lifetimes/issue-55796.stderr
index 5809a56cd4b..5809a56cd4b 100644
--- a/src/test/ui/issues/issue-55796.stderr
+++ b/src/test/ui/lifetimes/issue-55796.stderr
diff --git a/src/test/ui/issues/issue-11154.rs b/src/test/ui/lto/issue-11154.rs
index e11cdc82f32..e11cdc82f32 100644
--- a/src/test/ui/issues/issue-11154.rs
+++ b/src/test/ui/lto/issue-11154.rs
diff --git a/src/test/ui/issues/issue-11154.stderr b/src/test/ui/lto/issue-11154.stderr
index 8eec8b37c85..8eec8b37c85 100644
--- a/src/test/ui/issues/issue-11154.stderr
+++ b/src/test/ui/lto/issue-11154.stderr
diff --git a/src/test/ui/rfc-2011-nicer-assert-messages/feature-gate-generic_assert.rs b/src/test/ui/macros/rfc-2011-nicer-assert-messages/feature-gate-generic_assert.rs
index f70ca87e304..f70ca87e304 100644
--- a/src/test/ui/rfc-2011-nicer-assert-messages/feature-gate-generic_assert.rs
+++ b/src/test/ui/macros/rfc-2011-nicer-assert-messages/feature-gate-generic_assert.rs
diff --git a/src/test/ui/issues/issue-46023.rs b/src/test/ui/nll/issue-46023.rs
index a923eb24421..a923eb24421 100644
--- a/src/test/ui/issues/issue-46023.rs
+++ b/src/test/ui/nll/issue-46023.rs
diff --git a/src/test/ui/issues/issue-46023.stderr b/src/test/ui/nll/issue-46023.stderr
index ca19c250120..ca19c250120 100644
--- a/src/test/ui/issues/issue-46023.stderr
+++ b/src/test/ui/nll/issue-46023.stderr
diff --git a/src/test/ui/privacy/macro-private-reexport.rs b/src/test/ui/privacy/macro-private-reexport.rs
new file mode 100644
index 00000000000..d0aab528ed4
--- /dev/null
+++ b/src/test/ui/privacy/macro-private-reexport.rs
@@ -0,0 +1,17 @@
+// edition:2021
+
+#![feature(decl_macro)]
+
+mod foo {
+    macro_rules! bar {
+        () => {};
+    }
+
+    pub use bar as _; //~ ERROR `bar` is only public within the crate, and cannot be re-exported outside
+
+    macro baz() {}
+
+    pub use baz as _; //~ ERROR `baz` is private, and cannot be re-exported
+}
+
+fn main() {}
diff --git a/src/test/ui/privacy/macro-private-reexport.stderr b/src/test/ui/privacy/macro-private-reexport.stderr
new file mode 100644
index 00000000000..b8768f3612e
--- /dev/null
+++ b/src/test/ui/privacy/macro-private-reexport.stderr
@@ -0,0 +1,29 @@
+error[E0364]: `bar` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/macro-private-reexport.rs:10:13
+   |
+LL |     pub use bar as _;
+   |             ^^^^^^^^
+   |
+help: consider adding a `#[macro_export]` to the macro in the imported module
+  --> $DIR/macro-private-reexport.rs:6:5
+   |
+LL | /     macro_rules! bar {
+LL | |         () => {};
+LL | |     }
+   | |_____^
+
+error[E0364]: `baz` is private, and cannot be re-exported
+  --> $DIR/macro-private-reexport.rs:14:13
+   |
+LL |     pub use baz as _;
+   |             ^^^^^^^^
+   |
+note: consider marking `baz` as `pub` in the imported module
+  --> $DIR/macro-private-reexport.rs:14:13
+   |
+LL |     pub use baz as _;
+   |             ^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0364`.
diff --git a/src/test/ui/resolve/filter-intrinsics.rs b/src/test/ui/resolve/filter-intrinsics.rs
new file mode 100644
index 00000000000..c0956ef85af
--- /dev/null
+++ b/src/test/ui/resolve/filter-intrinsics.rs
@@ -0,0 +1,10 @@
+fn main() {
+    // Should suggest only `std::mem::size_of`
+    let _ = size_of::<usize>();
+    //~^ ERROR cannot find
+
+    // Should suggest `std::intrinsics::fabsf64`,
+    // since there is no non-intrinsic to suggest.
+    let _ = fabsf64(1.0);
+    //~^ ERROR cannot find
+}
diff --git a/src/test/ui/resolve/filter-intrinsics.stderr b/src/test/ui/resolve/filter-intrinsics.stderr
new file mode 100644
index 00000000000..955070891fb
--- /dev/null
+++ b/src/test/ui/resolve/filter-intrinsics.stderr
@@ -0,0 +1,25 @@
+error[E0425]: cannot find function `size_of` in this scope
+  --> $DIR/filter-intrinsics.rs:3:13
+   |
+LL |     let _ = size_of::<usize>();
+   |             ^^^^^^^ not found in this scope
+   |
+help: consider importing this function
+   |
+LL | use std::mem::size_of;
+   |
+
+error[E0425]: cannot find function `fabsf64` in this scope
+  --> $DIR/filter-intrinsics.rs:8:13
+   |
+LL |     let _ = fabsf64(1.0);
+   |             ^^^^^^^ not found in this scope
+   |
+help: consider importing this function
+   |
+LL | use std::intrinsics::fabsf64;
+   |
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0425`.
diff --git a/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr b/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr
index 9e48e26b1df..9f8c928c32c 100644
--- a/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr
@@ -4,11 +4,11 @@ error[E0364]: `legacy_macro` is only public within the crate, and cannot be re-e
 LL |     pub use legacy_macro as _;
    |             ^^^^^^^^^^^^^^^^^
    |
-note: consider marking `legacy_macro` as `pub` in the imported module
-  --> $DIR/macro-rules.rs:11:13
+help: consider adding a `#[macro_export]` to the macro in the imported module
+  --> $DIR/macro-rules.rs:7:5
    |
-LL |     pub use legacy_macro as _;
-   |             ^^^^^^^^^^^^^^^^^
+LL |     macro_rules! legacy_macro { () => () }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0659]: `legacy_macro` is ambiguous
   --> $DIR/macro-rules.rs:31:13
diff --git a/src/test/ui/issues/issue-18400.rs b/src/test/ui/traits/issue-18400.rs
index fdd11512da3..fdd11512da3 100644
--- a/src/test/ui/issues/issue-18400.rs
+++ b/src/test/ui/traits/issue-18400.rs
diff --git a/src/test/ui/issues/issue-18400.stderr b/src/test/ui/traits/issue-18400.stderr
index 92e0f60079f..92e0f60079f 100644
--- a/src/test/ui/issues/issue-18400.stderr
+++ b/src/test/ui/traits/issue-18400.stderr
diff --git a/src/test/ui/issues/issue-18412.rs b/src/test/ui/traits/issue-18412.rs
index fe1cfb3dffa..fe1cfb3dffa 100644
--- a/src/test/ui/issues/issue-18412.rs
+++ b/src/test/ui/traits/issue-18412.rs
diff --git a/src/test/ui/issues/issue-35869.rs b/src/test/ui/traits/issue-35869.rs
index b9b4c972e58..b9b4c972e58 100644
--- a/src/test/ui/issues/issue-35869.rs
+++ b/src/test/ui/traits/issue-35869.rs
diff --git a/src/test/ui/issues/issue-35869.stderr b/src/test/ui/traits/issue-35869.stderr
index 0780109b843..0780109b843 100644
--- a/src/test/ui/issues/issue-35869.stderr
+++ b/src/test/ui/traits/issue-35869.stderr
diff --git a/src/test/ui/issues/issue-29124.rs b/src/test/ui/typeck/issue-29124.rs
index dd278484175..dd278484175 100644
--- a/src/test/ui/issues/issue-29124.rs
+++ b/src/test/ui/typeck/issue-29124.rs
diff --git a/src/test/ui/issues/issue-29124.stderr b/src/test/ui/typeck/issue-29124.stderr
index c5d2ec08409..c5d2ec08409 100644
--- a/src/test/ui/issues/issue-29124.stderr
+++ b/src/test/ui/typeck/issue-29124.stderr
diff --git a/src/tools/tidy/src/ui_tests.rs b/src/tools/tidy/src/ui_tests.rs
index 135a12b5571..f59121181d2 100644
--- a/src/tools/tidy/src/ui_tests.rs
+++ b/src/tools/tidy/src/ui_tests.rs
@@ -7,8 +7,8 @@ use std::path::Path;
 
 const ENTRY_LIMIT: usize = 1000;
 // FIXME: The following limits should be reduced eventually.
-const ROOT_ENTRY_LIMIT: usize = 969;
-const ISSUES_ENTRY_LIMIT: usize = 2211;
+const ROOT_ENTRY_LIMIT: usize = 968;
+const ISSUES_ENTRY_LIMIT: usize = 2179;
 
 fn check_entries(path: &Path, bad: &mut bool) {
     let dirs = walkdir::WalkDir::new(&path.join("test/ui"))