Merge pull request #4270 from rust-lang/rustup-2025-04-12

Automatic Rustup

.github/ISSUE_TEMPLATE/tracking_issue.md

@@ -41,7 +41,10 @@ for larger features an implementation could be broken up into multiple PRs.
 - [ ] Implement the RFC (cc @rust-lang/XXX -- can anyone write up mentoring
       instructions?)
 - [ ] Adjust documentation ([see instructions on rustc-dev-guide][doc-guide])
-- [ ] Formatting for new syntax has been added to the [Style Guide] ([nightly-style-procedure])
+- [ ] Style updates for any new syntax ([nightly-style-procedure])
+  - [ ] Style team decision on new formatting
+  - [ ] Formatting for new syntax has been added to the [Style Guide]
+  - [ ] (non-blocking) Formatting has been implemented in `rustfmt`
 - [ ] Stabilization PR ([see instructions on rustc-dev-guide][stabilization-guide])
 
 [stabilization-guide]: https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr

Cargo.lock

@@ -3217,17 +3217,6 @@ dependencies = [
  "tikv-jemalloc-sys",
 ]
 
-[[package]]
-name = "rustc-rayon"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2cd9fb077db982d7ceb42a90471e5a69a990b58f71e06f0d8340bb2cf35eb751"
-dependencies = [
- "either",
- "indexmap",
- "rustc-rayon-core",
-]
-
 [[package]]
 name = "rustc-rayon-core"
 version = "0.5.0"
@@ -3599,7 +3588,7 @@ dependencies = [
  "parking_lot",
  "portable-atomic",
  "rustc-hash 2.1.1",
- "rustc-rayon",
+ "rustc-rayon-core",
  "rustc-stable-hash",
  "rustc_arena",
  "rustc_graphviz",
@@ -3945,7 +3934,6 @@ dependencies = [
 name = "rustc_interface"
 version = "0.0.0"
 dependencies = [
- "rustc-rayon",
  "rustc-rayon-core",
  "rustc_abi",
  "rustc_ast",
@@ -4409,7 +4397,6 @@ dependencies = [
  "rustc_feature",
  "rustc_fluent_macro",
  "rustc_hir",
- "rustc_index",
  "rustc_macros",
  "rustc_metadata",
  "rustc_middle",
@@ -4456,6 +4443,7 @@ dependencies = [
  "bitflags",
  "getopts",
  "libc",
+ "rand 0.9.0",
  "rustc_abi",
  "rustc_ast",
  "rustc_data_structures",

compiler/rustc_ast/src/expand/mod.rs

@@ -13,12 +13,12 @@ pub mod typetree;
 #[derive(Debug, Clone, Encodable, Decodable, HashStable_Generic)]
 pub struct StrippedCfgItem<ModId = DefId> {
     pub parent_module: ModId,
-    pub name: Ident,
+    pub ident: Ident,
     pub cfg: MetaItem,
 }
 
 impl<ModId> StrippedCfgItem<ModId> {
     pub fn map_mod_id<New>(self, f: impl FnOnce(ModId) -> New) -> StrippedCfgItem<New> {
-        StrippedCfgItem { parent_module: f(self.parent_module), name: self.name, cfg: self.cfg }
+        StrippedCfgItem { parent_module: f(self.parent_module), ident: self.ident, cfg: self.cfg }
     }
 }

compiler/rustc_ast_lowering/src/delegation.rs

@@ -47,7 +47,7 @@ use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{Asyncness, ResolverAstLowering};
-use rustc_span::{Ident, Span};
+use rustc_span::{Ident, Span, Symbol};
 use {rustc_ast as ast, rustc_hir as hir};
 
 use super::{GenericArgsMode, ImplTraitContext, LoweringContext, ParamMode};
@@ -234,12 +234,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         hir::FnSig { decl, header, span }
     }
 
-    fn generate_param(&mut self, span: Span) -> (hir::Param<'hir>, NodeId) {
+    fn generate_param(&mut self, idx: usize, span: Span) -> (hir::Param<'hir>, NodeId) {
         let pat_node_id = self.next_node_id();
         let pat_id = self.lower_node_id(pat_node_id);
+        let ident = Ident::with_dummy_span(Symbol::intern(&format!("arg{idx}")));
         let pat = self.arena.alloc(hir::Pat {
             hir_id: pat_id,
-            kind: hir::PatKind::Binding(hir::BindingMode::NONE, pat_id, Ident::empty(), None),
+            kind: hir::PatKind::Binding(hir::BindingMode::NONE, pat_id, ident, None),
             span,
             default_binding_modes: false,
         });
@@ -247,9 +248,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
         (hir::Param { hir_id: self.next_id(), pat, ty_span: span, span }, pat_node_id)
     }
 
-    fn generate_arg(&mut self, param_id: HirId, span: Span) -> hir::Expr<'hir> {
+    fn generate_arg(&mut self, idx: usize, param_id: HirId, span: Span) -> hir::Expr<'hir> {
         let segments = self.arena.alloc_from_iter(iter::once(hir::PathSegment {
-            ident: Ident::empty(),
+            ident: Ident::with_dummy_span(Symbol::intern(&format!("arg{idx}"))),
             hir_id: self.next_id(),
             res: Res::Local(param_id),
             args: None,
@@ -273,7 +274,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let mut args: Vec<hir::Expr<'_>> = Vec::with_capacity(param_count);
 
             for idx in 0..param_count {
-                let (param, pat_node_id) = this.generate_param(span);
+                let (param, pat_node_id) = this.generate_param(idx, span);
                 parameters.push(param);
 
                 let arg = if let Some(block) = block
@@ -289,7 +290,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     this.ident_and_label_to_local_id.insert(pat_node_id, param.pat.hir_id.local_id);
                     this.lower_target_expr(&block)
                 } else {
-                    this.generate_arg(param.pat.hir_id, span)
+                    this.generate_arg(idx, param.pat.hir_id, span)
                 };
                 args.push(arg);
             }

compiler/rustc_ast_lowering/src/item.rs

@@ -645,7 +645,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         (
                             // Disallow `impl Trait` in foreign items.
                             this.lower_fn_decl(fdec, i.id, sig.span, FnDeclKind::ExternFn, None),
-                            this.lower_fn_params_to_names(fdec),
+                            this.lower_fn_params_to_idents(fdec),
                         )
                     });
 
@@ -833,7 +833,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             }) => {
                 // FIXME(contracts): Deny contract here since it won't apply to
                 // any impl method or callees.
-                let names = self.lower_fn_params_to_names(&sig.decl);
+                let idents = self.lower_fn_params_to_idents(&sig.decl);
                 let (generics, sig) = self.lower_method_sig(
                     generics,
                     sig,
@@ -851,7 +851,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 (
                     *ident,
                     generics,
-                    hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(names)),
+                    hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(idents)),
                     false,
                 )
             }

compiler/rustc_ast_lowering/src/lib.rs

@@ -1247,7 +1247,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     safety: self.lower_safety(f.safety, hir::Safety::Safe),
                     abi: self.lower_extern(f.ext),
                     decl: self.lower_fn_decl(&f.decl, t.id, t.span, FnDeclKind::Pointer, None),
-                    param_names: self.lower_fn_params_to_names(&f.decl),
+                    param_idents: self.lower_fn_params_to_idents(&f.decl),
                 }))
             }
             TyKind::UnsafeBinder(f) => {
@@ -1494,7 +1494,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         }))
     }
 
-    fn lower_fn_params_to_names(&mut self, decl: &FnDecl) -> &'hir [Option<Ident>] {
+    fn lower_fn_params_to_idents(&mut self, decl: &FnDecl) -> &'hir [Option<Ident>] {
         self.arena.alloc_from_iter(decl.inputs.iter().map(|param| match param.pat.kind {
             PatKind::Missing => None,
             PatKind::Ident(_, ident, _) => Some(self.lower_ident(ident)),
@@ -2034,7 +2034,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     }
 
     fn lower_array_length_to_const_arg(&mut self, c: &AnonConst) -> &'hir hir::ConstArg<'hir> {
-        match c.value.kind {
+        // We cannot just match on `ExprKind::Underscore` as `(_)` is represented as
+        // `ExprKind::Paren(ExprKind::Underscore)` and should also be lowered to `GenericArg::Infer`
+        match c.value.peel_parens().kind {
             ExprKind::Underscore => {
                 if !self.tcx.features().generic_arg_infer() {
                     feature_err(

compiler/rustc_ast_pretty/src/pprust/tests.rs

@@ -7,12 +7,12 @@ use super::*;
 fn fun_to_string(
     decl: &ast::FnDecl,
     header: ast::FnHeader,
-    name: Ident,
+    ident: Ident,
     generics: &ast::Generics,
 ) -> String {
     to_string(|s| {
         s.head("");
-        s.print_fn(decl, header, Some(name), generics);
+        s.print_fn(decl, header, Some(ident), generics);
         s.end(); // Close the head box.
         s.end(); // Close the outer box.
     })

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -2500,11 +2500,11 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         );
         let ty::Tuple(params) = tupled_params.kind() else { return };
 
-        // Find the first argument with a matching type, get its name
+        // Find the first argument with a matching type and get its identifier.
-        let Some(this_name) = params.iter().zip(tcx.hir_body_param_names(closure.body)).find_map(
+        let Some(this_name) = params.iter().zip(tcx.hir_body_param_idents(closure.body)).find_map(
-            |(param_ty, name)| {
+            |(param_ty, ident)| {
                 // FIXME: also support deref for stuff like `Rc` arguments
-                if param_ty.peel_refs() == local_ty { name } else { None }
+                if param_ty.peel_refs() == local_ty { ident } else { None }
             },
         ) else {
             return;
@@ -3774,7 +3774,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 method_args,
                 *fn_span,
                 call_source.from_hir_call(),
-                self.infcx.tcx.fn_arg_names(method_did)[0],
+                self.infcx.tcx.fn_arg_idents(method_did)[0],
             )
         {
             err.note(format!("borrow occurs due to deref coercion to `{deref_target_ty}`"));

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1026,7 +1026,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 method_args,
                 *fn_span,
                 call_source.from_hir_call(),
-                self.infcx.tcx.fn_arg_names(method_did)[0],
+                self.infcx.tcx.fn_arg_idents(method_did)[0],
             );
 
             return FnSelfUse {

compiler/rustc_builtin_macros/src/autodiff.rs

@@ -234,7 +234,7 @@ mod llvm_enzyme {
         let meta_item_vec: ThinVec<MetaItemInner> = match meta_item.kind {
             ast::MetaItemKind::List(ref vec) => vec.clone(),
             _ => {
-                dcx.emit_err(errors::AutoDiffInvalidApplication { span: item.span() });
+                dcx.emit_err(errors::AutoDiffMissingConfig { span: item.span() });
                 return vec![item];
             }
         };

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -20,14 +20,14 @@ use crate::errors;
 struct ProcMacroDerive {
     id: NodeId,
     trait_name: Symbol,
-    function_name: Ident,
+    function_ident: Ident,
     span: Span,
     attrs: Vec<Symbol>,
 }
 
 struct ProcMacroDef {
     id: NodeId,
-    function_name: Ident,
+    function_ident: Ident,
     span: Span,
 }
 
@@ -95,7 +95,7 @@ impl<'a> CollectProcMacros<'a> {
     fn collect_custom_derive(
         &mut self,
         item: &'a ast::Item,
-        function_name: Ident,
+        function_ident: Ident,
         attr: &'a ast::Attribute,
     ) {
         let Some((trait_name, proc_attrs)) =
@@ -109,7 +109,7 @@ impl<'a> CollectProcMacros<'a> {
                 id: item.id,
                 span: item.span,
                 trait_name,
-                function_name,
+                function_ident,
                 attrs: proc_attrs,
             }));
         } else {
@@ -123,12 +123,12 @@ impl<'a> CollectProcMacros<'a> {
         }
     }
 
-    fn collect_attr_proc_macro(&mut self, item: &'a ast::Item, function_name: Ident) {
+    fn collect_attr_proc_macro(&mut self, item: &'a ast::Item, function_ident: Ident) {
         if self.in_root && item.vis.kind.is_pub() {
             self.macros.push(ProcMacro::Attr(ProcMacroDef {
                 id: item.id,
                 span: item.span,
-                function_name,
+                function_ident,
             }));
         } else {
             let msg = if !self.in_root {
@@ -141,12 +141,12 @@ impl<'a> CollectProcMacros<'a> {
         }
     }
 
-    fn collect_bang_proc_macro(&mut self, item: &'a ast::Item, function_name: Ident) {
+    fn collect_bang_proc_macro(&mut self, item: &'a ast::Item, function_ident: Ident) {
         if self.in_root && item.vis.kind.is_pub() {
             self.macros.push(ProcMacro::Bang(ProcMacroDef {
                 id: item.id,
                 span: item.span,
-                function_name,
+                function_ident,
             }));
         } else {
             let msg = if !self.in_root {
@@ -303,7 +303,7 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
                 ProcMacro::Derive(m) => m.span,
                 ProcMacro::Attr(m) | ProcMacro::Bang(m) => m.span,
             };
-            let local_path = |cx: &ExtCtxt<'_>, name| cx.expr_path(cx.path(span, vec![name]));
+            let local_path = |cx: &ExtCtxt<'_>, ident| cx.expr_path(cx.path(span, vec![ident]));
             let proc_macro_ty_method_path = |cx: &ExtCtxt<'_>, method| {
                 cx.expr_path(cx.path(
                     span.with_ctxt(harness_span.ctxt()),
@@ -327,7 +327,7 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
                                     .map(|&s| cx.expr_str(span, s))
                                     .collect::<ThinVec<_>>(),
                             ),
-                            local_path(cx, cd.function_name),
+                            local_path(cx, cd.function_ident),
                         ],
                     )
                 }
@@ -345,8 +345,8 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
                         harness_span,
                         proc_macro_ty_method_path(cx, ident),
                         thin_vec![
-                            cx.expr_str(span, ca.function_name.name),
+                            cx.expr_str(span, ca.function_ident.name),
-                            local_path(cx, ca.function_name),
+                            local_path(cx, ca.function_ident),
                         ],
                     )
                 }

compiler/rustc_codegen_cranelift/src/driver/aot.rs

@@ -169,8 +169,11 @@ fn produce_final_output_artifacts(
         if codegen_results.modules.len() == 1 {
             // 1) Only one codegen unit. In this case it's no difficulty
             //    to copy `foo.0.x` to `foo.x`.
-            let module_name = Some(&codegen_results.modules[0].name[..]);
+            let path = crate_output.temp_path_for_cgu(
-            let path = crate_output.temp_path(output_type, module_name);
+                output_type,
+                &codegen_results.modules[0].name,
+                sess.invocation_temp.as_deref(),
+            );
             let output = crate_output.path(output_type);
             if !output_type.is_text_output() && output.is_tty() {
                 sess.dcx()
@@ -183,22 +186,16 @@ fn produce_final_output_artifacts(
                 ensure_removed(sess.dcx(), &path);
             }
         } else {
-            let extension = crate_output
-                .temp_path(output_type, None)
-                .extension()
-                .unwrap()
-                .to_str()
-                .unwrap()
-                .to_owned();
-
             if crate_output.outputs.contains_explicit_name(&output_type) {
                 // 2) Multiple codegen units, with `--emit foo=some_name`. We have
                 //    no good solution for this case, so warn the user.
-                sess.dcx().emit_warn(ssa_errors::IgnoringEmitPath { extension });
+                sess.dcx()
+                    .emit_warn(ssa_errors::IgnoringEmitPath { extension: output_type.extension() });
             } else if crate_output.single_output_file.is_some() {
                 // 3) Multiple codegen units, with `-o some_name`. We have
                 //    no good solution for this case, so warn the user.
-                sess.dcx().emit_warn(ssa_errors::IgnoringOutput { extension });
+                sess.dcx()
+                    .emit_warn(ssa_errors::IgnoringOutput { extension: output_type.extension() });
             } else {
                 // 4) Multiple codegen units, but no explicit name. We
                 //    just leave the `foo.0.x` files in place.
@@ -351,6 +348,7 @@ fn make_module(sess: &Session, name: String) -> UnwindModule<ObjectModule> {
 
 fn emit_cgu(
     output_filenames: &OutputFilenames,
+    invocation_temp: Option<&str>,
     prof: &SelfProfilerRef,
     name: String,
     module: UnwindModule<ObjectModule>,
@@ -366,6 +364,7 @@ fn emit_cgu(
 
     let module_regular = emit_module(
         output_filenames,
+        invocation_temp,
         prof,
         product.object,
         ModuleKind::Regular,
@@ -391,6 +390,7 @@ fn emit_cgu(
 
 fn emit_module(
     output_filenames: &OutputFilenames,
+    invocation_temp: Option<&str>,
     prof: &SelfProfilerRef,
     mut object: cranelift_object::object::write::Object<'_>,
     kind: ModuleKind,
@@ -409,7 +409,7 @@ fn emit_module(
         object.set_section_data(comment_section, producer, 1);
     }
 
-    let tmp_file = output_filenames.temp_path(OutputType::Object, Some(&name));
+    let tmp_file = output_filenames.temp_path_for_cgu(OutputType::Object, &name, invocation_temp);
     let file = match File::create(&tmp_file) {
         Ok(file) => file,
         Err(err) => return Err(format!("error creating object file: {}", err)),
@@ -449,8 +449,11 @@ fn reuse_workproduct_for_cgu(
     cgu: &CodegenUnit<'_>,
 ) -> Result<ModuleCodegenResult, String> {
     let work_product = cgu.previous_work_product(tcx);
-    let obj_out_regular =
+    let obj_out_regular = tcx.output_filenames(()).temp_path_for_cgu(
-        tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));
+        OutputType::Object,
+        cgu.name().as_str(),
+        tcx.sess.invocation_temp.as_deref(),
+    );
     let source_file_regular = rustc_incremental::in_incr_comp_dir_sess(
         &tcx.sess,
         &work_product.saved_files.get("o").expect("no saved object file in work product"),
@@ -595,13 +598,19 @@ fn module_codegen(
 
         let global_asm_object_file =
             profiler.generic_activity_with_arg("compile assembly", &*cgu_name).run(|| {
-                crate::global_asm::compile_global_asm(&global_asm_config, &cgu_name, &cx.global_asm)
+                crate::global_asm::compile_global_asm(
+                    &global_asm_config,
+                    &cgu_name,
+                    &cx.global_asm,
+                    cx.invocation_temp.as_deref(),
+                )
             })?;
 
         let codegen_result =
             profiler.generic_activity_with_arg("write object file", &*cgu_name).run(|| {
                 emit_cgu(
                     &global_asm_config.output_filenames,
+                    cx.invocation_temp.as_deref(),
                     &profiler,
                     cgu_name,
                     module,
@@ -626,8 +635,11 @@ fn emit_metadata_module(tcx: TyCtxt<'_>, metadata: &EncodedMetadata) -> Compiled
         .as_str()
         .to_string();
 
-    let tmp_file =
+    let tmp_file = tcx.output_filenames(()).temp_path_for_cgu(
-        tcx.output_filenames(()).temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
+        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);
@@ -657,6 +669,7 @@ fn emit_allocator_module(tcx: TyCtxt<'_>) -> Option<CompiledModule> {
 
         match emit_module(
             tcx.output_filenames(()),
+            tcx.sess.invocation_temp.as_deref(),
             &tcx.sess.prof,
             product.object,
             ModuleKind::Allocator,
@@ -728,26 +741,27 @@ pub(crate) fn run_aot(
 
     let concurrency_limiter = IntoDynSyncSend(ConcurrencyLimiter::new(todo_cgus.len()));
 
-    let modules = tcx.sess.time("codegen mono items", || {
+    let modules: Vec<_> =
-        let mut modules: Vec<_> = par_map(todo_cgus, |(_, cgu)| {
+        tcx.sess.time("codegen mono items", || {
-            let dep_node = cgu.codegen_dep_node(tcx);
+            let modules: Vec<_> = par_map(todo_cgus, |(_, cgu)| {
-            tcx.dep_graph
+                let dep_node = cgu.codegen_dep_node(tcx);
-                .with_task(
+                let (module, _) = tcx.dep_graph.with_task(
                     dep_node,
                     tcx,
                     (global_asm_config.clone(), cgu.name(), concurrency_limiter.acquire(tcx.dcx())),
                     module_codegen,
                     Some(rustc_middle::dep_graph::hash_result),
-                )
+                );
-                .0
+                IntoDynSyncSend(module)
-        });
+            });
-        modules.extend(
+            modules
-            done_cgus
                 .into_iter()
-                .map(|(_, cgu)| OngoingModuleCodegen::Sync(reuse_workproduct_for_cgu(tcx, cgu))),
+                .map(|module| module.0)
-        );
+                .chain(done_cgus.into_iter().map(|(_, cgu)| {
-        modules
+                    OngoingModuleCodegen::Sync(reuse_workproduct_for_cgu(tcx, cgu))
-    });
+                }))
+                .collect()
+        });
 
     let allocator_module = emit_allocator_module(tcx);
 

compiler/rustc_codegen_cranelift/src/global_asm.rs

@@ -132,6 +132,7 @@ pub(crate) fn compile_global_asm(
     config: &GlobalAsmConfig,
     cgu_name: &str,
     global_asm: &str,
+    invocation_temp: Option<&str>,
 ) -> Result<Option<PathBuf>, String> {
     if global_asm.is_empty() {
         return Ok(None);
@@ -146,7 +147,7 @@ pub(crate) fn compile_global_asm(
     global_asm.push('\n');
 
     let global_asm_object_file = add_file_stem_postfix(
-        config.output_filenames.temp_path(OutputType::Object, Some(cgu_name)),
+        config.output_filenames.temp_path_for_cgu(OutputType::Object, cgu_name, invocation_temp),
         ".asm",
     );
 

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -124,6 +124,7 @@ impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
 /// inside a single codegen unit with the exception of the Cranelift [`Module`](cranelift_module::Module).
 struct CodegenCx {
     output_filenames: Arc<OutputFilenames>,
+    invocation_temp: Option<String>,
     should_write_ir: bool,
     global_asm: String,
     inline_asm_index: usize,
@@ -142,6 +143,7 @@ impl CodegenCx {
         };
         CodegenCx {
             output_filenames: tcx.output_filenames(()).clone(),
+            invocation_temp: tcx.sess.invocation_temp.clone(),
             should_write_ir: crate::pretty_clif::should_write_ir(tcx),
             global_asm: String::new(),
             inline_asm_index: 0,

compiler/rustc_codegen_cranelift/src/main_shim.rs

@@ -104,7 +104,7 @@ pub(crate) fn maybe_create_entry_wrapper(
                 let termination_trait = tcx.require_lang_item(LangItem::Termination, None);
                 let report = tcx
                     .associated_items(termination_trait)
-                    .find_by_name_and_kind(
+                    .find_by_ident_and_kind(
                         tcx,
                         Ident::from_str("report"),
                         AssocKind::Fn,

compiler/rustc_codegen_gcc/src/back/write.rs

@@ -24,19 +24,23 @@ pub(crate) unsafe fn codegen(
     {
         let context = &module.module_llvm.context;
 
-        let module_name = module.name.clone();
-
         let should_combine_object_files = module.module_llvm.should_combine_object_files;
 
-        let module_name = Some(&module_name[..]);
-
         // NOTE: Only generate object files with GIMPLE when this environment variable is set for
         // now because this requires a particular setup (same gcc/lto1/lto-wrapper commit as libgccjit).
         // TODO(antoyo): remove this environment variable.
         let fat_lto = env::var("EMBED_LTO_BITCODE").as_deref() == Ok("1");
 
-        let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
+        let bc_out = cgcx.output_filenames.temp_path_for_cgu(
-        let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
+            OutputType::Bitcode,
+            &module.name,
+            cgcx.invocation_temp.as_deref(),
+        );
+        let obj_out = cgcx.output_filenames.temp_path_for_cgu(
+            OutputType::Object,
+            &module.name,
+            cgcx.invocation_temp.as_deref(),
+        );
 
         if config.bitcode_needed() {
             if fat_lto {
@@ -117,14 +121,22 @@ pub(crate) unsafe fn codegen(
         }
 
         if config.emit_ir {
-            let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
+            let out = cgcx.output_filenames.temp_path_for_cgu(
+                OutputType::LlvmAssembly,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
             std::fs::write(out, "").expect("write file");
         }
 
         if config.emit_asm {
             let _timer =
                 cgcx.prof.generic_activity_with_arg("GCC_module_codegen_emit_asm", &*module.name);
-            let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
+            let path = cgcx.output_filenames.temp_path_for_cgu(
+                OutputType::Assembly,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
             context.compile_to_file(OutputKind::Assembler, path.to_str().expect("path to str"));
         }
 
@@ -238,6 +250,7 @@ pub(crate) unsafe fn codegen(
         config.emit_asm,
         config.emit_ir,
         &cgcx.output_filenames,
+        cgcx.invocation_temp.as_deref(),
     ))
 }
 

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -119,14 +119,18 @@ pub(crate) fn create_target_machine(tcx: TyCtxt<'_>, mod_name: &str) -> OwnedTar
         tcx.output_filenames(()).split_dwarf_path(
             tcx.sess.split_debuginfo(),
             tcx.sess.opts.unstable_opts.split_dwarf_kind,
-            Some(mod_name),
+            mod_name,
+            tcx.sess.invocation_temp.as_deref(),
         )
     } else {
         None
     };
 
-    let output_obj_file =
+    let output_obj_file = Some(tcx.output_filenames(()).temp_path_for_cgu(
-        Some(tcx.output_filenames(()).temp_path(OutputType::Object, Some(mod_name)));
+        OutputType::Object,
+        mod_name,
+        tcx.sess.invocation_temp.as_deref(),
+    ));
     let config = TargetMachineFactoryConfig { split_dwarf_file, output_obj_file };
 
     target_machine_factory(
@@ -330,8 +334,11 @@ pub(crate) fn save_temp_bitcode(
         return;
     }
     let ext = format!("{name}.bc");
-    let cgu = Some(&module.name[..]);
+    let path = cgcx.output_filenames.temp_path_ext_for_cgu(
-    let path = cgcx.output_filenames.temp_path_ext(&ext, cgu);
+        &ext,
+        &module.name,
+        cgcx.invocation_temp.as_deref(),
+    );
     write_bitcode_to_file(module, &path)
 }
 
@@ -694,11 +701,12 @@ pub(crate) unsafe fn optimize(
     let llcx = &*module.module_llvm.llcx;
     let _handlers = DiagnosticHandlers::new(cgcx, dcx, llcx, module, CodegenDiagnosticsStage::Opt);
 
-    let module_name = module.name.clone();
-    let module_name = Some(&module_name[..]);
-
     if config.emit_no_opt_bc {
-        let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
+        let out = cgcx.output_filenames.temp_path_ext_for_cgu(
+            "no-opt.bc",
+            &module.name,
+            cgcx.invocation_temp.as_deref(),
+        );
         write_bitcode_to_file(module, &out)
     }
 
@@ -743,8 +751,11 @@ pub(crate) unsafe fn optimize(
         if let Some(thin_lto_buffer) = thin_lto_buffer {
             let thin_lto_buffer = unsafe { ThinBuffer::from_raw_ptr(thin_lto_buffer) };
             module.thin_lto_buffer = Some(thin_lto_buffer.data().to_vec());
-            let bc_summary_out =
+            let bc_summary_out = cgcx.output_filenames.temp_path_for_cgu(
-                cgcx.output_filenames.temp_path(OutputType::ThinLinkBitcode, module_name);
+                OutputType::ThinLinkBitcode,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
             if config.emit_thin_lto_summary
                 && let Some(thin_link_bitcode_filename) = bc_summary_out.file_name()
             {
@@ -801,8 +812,6 @@ pub(crate) unsafe fn codegen(
         let llmod = module.module_llvm.llmod();
         let llcx = &*module.module_llvm.llcx;
         let tm = &*module.module_llvm.tm;
-        let module_name = module.name.clone();
-        let module_name = Some(&module_name[..]);
         let _handlers =
             DiagnosticHandlers::new(cgcx, dcx, llcx, &module, CodegenDiagnosticsStage::Codegen);
 
@@ -814,8 +823,16 @@ pub(crate) unsafe fn codegen(
         // copy it to the .o file, and delete the bitcode if it wasn't
         // otherwise requested.
 
-        let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
+        let bc_out = cgcx.output_filenames.temp_path_for_cgu(
-        let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
+            OutputType::Bitcode,
+            &module.name,
+            cgcx.invocation_temp.as_deref(),
+        );
+        let obj_out = cgcx.output_filenames.temp_path_for_cgu(
+            OutputType::Object,
+            &module.name,
+            cgcx.invocation_temp.as_deref(),
+        );
 
         if config.bitcode_needed() {
             if config.emit_bc || config.emit_obj == EmitObj::Bitcode {
@@ -857,7 +874,11 @@ pub(crate) unsafe fn codegen(
         if config.emit_ir {
             let _timer =
                 cgcx.prof.generic_activity_with_arg("LLVM_module_codegen_emit_ir", &*module.name);
-            let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
+            let out = cgcx.output_filenames.temp_path_for_cgu(
+                OutputType::LlvmAssembly,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
             let out_c = path_to_c_string(&out);
 
             extern "C" fn demangle_callback(
@@ -899,7 +920,11 @@ pub(crate) unsafe fn codegen(
         if config.emit_asm {
             let _timer =
                 cgcx.prof.generic_activity_with_arg("LLVM_module_codegen_emit_asm", &*module.name);
-            let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
+            let path = cgcx.output_filenames.temp_path_for_cgu(
+                OutputType::Assembly,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
 
             // We can't use the same module for asm and object code output,
             // because that triggers various errors like invalid IR or broken
@@ -929,7 +954,9 @@ pub(crate) unsafe fn codegen(
                     .prof
                     .generic_activity_with_arg("LLVM_module_codegen_emit_obj", &*module.name);
 
-                let dwo_out = cgcx.output_filenames.temp_path_dwo(module_name);
+                let dwo_out = cgcx
+                    .output_filenames
+                    .temp_path_dwo_for_cgu(&module.name, cgcx.invocation_temp.as_deref());
                 let dwo_out = match (cgcx.split_debuginfo, cgcx.split_dwarf_kind) {
                     // Don't change how DWARF is emitted when disabled.
                     (SplitDebuginfo::Off, _) => None,
@@ -994,6 +1021,7 @@ pub(crate) unsafe fn codegen(
         config.emit_asm,
         config.emit_ir,
         &cgcx.output_filenames,
+        cgcx.invocation_temp.as_deref(),
     ))
 }
 

compiler/rustc_codegen_llvm/src/common.rs

@@ -4,8 +4,8 @@ use std::borrow::Borrow;
 
 use libc::{c_char, c_uint};
 use rustc_abi as abi;
+use rustc_abi::HasDataLayout;
 use rustc_abi::Primitive::Pointer;
-use rustc_abi::{AddressSpace, HasDataLayout};
 use rustc_ast::Mutability;
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
@@ -269,7 +269,8 @@ impl<'ll, 'tcx> ConstCodegenMethods for CodegenCx<'ll, 'tcx> {
             }
             Scalar::Ptr(ptr, _size) => {
                 let (prov, offset) = ptr.into_parts();
-                let (base_addr, base_addr_space) = match self.tcx.global_alloc(prov.alloc_id()) {
+                let global_alloc = self.tcx.global_alloc(prov.alloc_id());
+                let base_addr = match global_alloc {
                     GlobalAlloc::Memory(alloc) => {
                         // For ZSTs directly codegen an aligned pointer.
                         // This avoids generating a zero-sized constant value and actually needing a
@@ -301,12 +302,10 @@ impl<'ll, 'tcx> ConstCodegenMethods for CodegenCx<'ll, 'tcx> {
                                     format!("alloc_{hash:032x}").as_bytes(),
                                 );
                             }
-                            (value, AddressSpace::DATA)
+                            value
                         }
                     }
-                    GlobalAlloc::Function { instance, .. } => {
+                    GlobalAlloc::Function { instance, .. } => self.get_fn_addr(instance),
-                        (self.get_fn_addr(instance), self.data_layout().instruction_address_space)
-                    }
                     GlobalAlloc::VTable(ty, dyn_ty) => {
                         let alloc = self
                             .tcx
@@ -319,14 +318,15 @@ impl<'ll, 'tcx> ConstCodegenMethods for CodegenCx<'ll, 'tcx> {
                             .unwrap_memory();
                         let init = const_alloc_to_llvm(self, alloc, /*static*/ false);
                         let value = self.static_addr_of_impl(init, alloc.inner().align, None);
-                        (value, AddressSpace::DATA)
+                        value
                     }
                     GlobalAlloc::Static(def_id) => {
                         assert!(self.tcx.is_static(def_id));
                         assert!(!self.tcx.is_thread_local_static(def_id));
-                        (self.get_static(def_id), AddressSpace::DATA)
+                        self.get_static(def_id)
                     }
                 };
+                let base_addr_space = global_alloc.address_space(self);
                 let llval = unsafe {
                     llvm::LLVMConstInBoundsGEP2(
                         self.type_i8(),

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -910,7 +910,8 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
         && let Some(f) = output_filenames.split_dwarf_path(
             tcx.sess.split_debuginfo(),
             tcx.sess.opts.unstable_opts.split_dwarf_kind,
-            Some(codegen_unit_name),
+            codegen_unit_name,
+            tcx.sess.invocation_temp.as_deref(),
         ) {
         // We get a path relative to the working directory from split_dwarf_path
         Some(tcx.sess.source_map().path_mapping().to_real_filename(f))

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -1421,7 +1421,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
         return Ok(bx.shuffle_vector(args[0].immediate(), args[1].immediate(), indices));
     }
 
-    if name == sym::simd_insert {
+    if name == sym::simd_insert || name == sym::simd_insert_dyn {
         require!(
             in_elem == arg_tys[2],
             InvalidMonomorphization::InsertedType {
@@ -1432,40 +1432,49 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
                 out_ty: arg_tys[2]
             }
         );
-        let idx = bx
+
-            .const_to_opt_u128(args[1].immediate(), false)
+        let index_imm = if name == sym::simd_insert {
-            .expect("typeck should have ensure that this is a const");
+            let idx = bx
-        if idx >= in_len.into() {
+                .const_to_opt_u128(args[1].immediate(), false)
-            return_error!(InvalidMonomorphization::SimdIndexOutOfBounds {
+                .expect("typeck should have ensure that this is a const");
-                span,
+            if idx >= in_len.into() {
-                name,
+                return_error!(InvalidMonomorphization::SimdIndexOutOfBounds {
-                arg_idx: 1,
+                    span,
-                total_len: in_len.into(),
+                    name,
-            });
+                    arg_idx: 1,
-        }
+                    total_len: in_len.into(),
-        return Ok(bx.insert_element(
+                });
-            args[0].immediate(),
+            }
-            args[2].immediate(),
+            bx.const_i32(idx as i32)
-            bx.const_i32(idx as i32),
+        } else {
-        ));
+            args[1].immediate()
+        };
+
+        return Ok(bx.insert_element(args[0].immediate(), args[2].immediate(), index_imm));
     }
-    if name == sym::simd_extract {
+    if name == sym::simd_extract || name == sym::simd_extract_dyn {
         require!(
             ret_ty == in_elem,
             InvalidMonomorphization::ReturnType { span, name, in_elem, in_ty, ret_ty }
         );
-        let idx = bx
+        let index_imm = if name == sym::simd_extract {
-            .const_to_opt_u128(args[1].immediate(), false)
+            let idx = bx
-            .expect("typeck should have ensure that this is a const");
+                .const_to_opt_u128(args[1].immediate(), false)
-        if idx >= in_len.into() {
+                .expect("typeck should have ensure that this is a const");
-            return_error!(InvalidMonomorphization::SimdIndexOutOfBounds {
+            if idx >= in_len.into() {
-                span,
+                return_error!(InvalidMonomorphization::SimdIndexOutOfBounds {
-                name,
+                    span,
-                arg_idx: 1,
+                    name,
-                total_len: in_len.into(),
+                    arg_idx: 1,
-            });
+                    total_len: in_len.into(),
-        }
+                });
-        return Ok(bx.extract_element(args[0].immediate(), bx.const_i32(idx as i32)));
+            }
+            bx.const_i32(idx as i32)
+        } else {
+            args[1].immediate()
+        };
+
+        return Ok(bx.extract_element(args[0].immediate(), index_imm));
     }
 
     if name == sym::simd_select {

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -112,8 +112,12 @@ pub fn link_binary(
                 codegen_results.crate_info.local_crate_name,
             );
             let crate_name = format!("{}", codegen_results.crate_info.local_crate_name);
-            let out_filename =
+            let out_filename = output.file_for_writing(
-                output.file_for_writing(outputs, OutputType::Exe, Some(crate_name.as_str()));
+                outputs,
+                OutputType::Exe,
+                &crate_name,
+                sess.invocation_temp.as_deref(),
+            );
             match crate_type {
                 CrateType::Rlib => {
                     let _timer = sess.timer("link_rlib");

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -306,14 +306,18 @@ impl TargetMachineFactoryConfig {
             cgcx.output_filenames.split_dwarf_path(
                 cgcx.split_debuginfo,
                 cgcx.split_dwarf_kind,
-                Some(module_name),
+                module_name,
+                cgcx.invocation_temp.as_deref(),
             )
         } else {
             None
         };
 
-        let output_obj_file =
+        let output_obj_file = Some(cgcx.output_filenames.temp_path_for_cgu(
-            Some(cgcx.output_filenames.temp_path(OutputType::Object, Some(module_name)));
+            OutputType::Object,
+            module_name,
+            cgcx.invocation_temp.as_deref(),
+        ));
         TargetMachineFactoryConfig { split_dwarf_file, output_obj_file }
     }
 }
@@ -344,6 +348,7 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     pub crate_types: Vec<CrateType>,
     pub each_linked_rlib_for_lto: Vec<(CrateNum, PathBuf)>,
     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>,
@@ -582,8 +587,11 @@ fn produce_final_output_artifacts(
         if let [module] = &compiled_modules.modules[..] {
             // 1) Only one codegen unit. In this case it's no difficulty
             //    to copy `foo.0.x` to `foo.x`.
-            let module_name = Some(&module.name[..]);
+            let path = crate_output.temp_path_for_cgu(
-            let path = crate_output.temp_path(output_type, module_name);
+                output_type,
+                &module.name,
+                sess.invocation_temp.as_deref(),
+            );
             let output = crate_output.path(output_type);
             if !output_type.is_text_output() && output.is_tty() {
                 sess.dcx()
@@ -596,22 +604,15 @@ fn produce_final_output_artifacts(
                 ensure_removed(sess.dcx(), &path);
             }
         } else {
-            let extension = crate_output
-                .temp_path(output_type, None)
-                .extension()
-                .unwrap()
-                .to_str()
-                .unwrap()
-                .to_owned();
-
             if crate_output.outputs.contains_explicit_name(&output_type) {
                 // 2) Multiple codegen units, with `--emit foo=some_name`. We have
                 //    no good solution for this case, so warn the user.
-                sess.dcx().emit_warn(errors::IgnoringEmitPath { extension });
+                sess.dcx()
+                    .emit_warn(errors::IgnoringEmitPath { extension: output_type.extension() });
             } else if crate_output.single_output_file.is_some() {
                 // 3) Multiple codegen units, with `-o some_name`. We have
                 //    no good solution for this case, so warn the user.
-                sess.dcx().emit_warn(errors::IgnoringOutput { extension });
+                sess.dcx().emit_warn(errors::IgnoringOutput { extension: output_type.extension() });
             } else {
                 // 4) Multiple codegen units, but no explicit name. We
                 //    just leave the `foo.0.x` files in place.
@@ -967,7 +968,12 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
         module.source.saved_files.get("dwo").as_ref().and_then(|saved_dwarf_object_file| {
             let dwarf_obj_out = cgcx
                 .output_filenames
-                .split_dwarf_path(cgcx.split_debuginfo, cgcx.split_dwarf_kind, Some(&module.name))
+                .split_dwarf_path(
+                    cgcx.split_debuginfo,
+                    cgcx.split_dwarf_kind,
+                    &module.name,
+                    cgcx.invocation_temp.as_deref(),
+                )
                 .expect(
                     "saved dwarf object in work product but `split_dwarf_path` returned `None`",
                 );
@@ -977,7 +983,11 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
     let mut load_from_incr_cache = |perform, output_type: OutputType| {
         if perform {
             let saved_file = module.source.saved_files.get(output_type.extension())?;
-            let output_path = cgcx.output_filenames.temp_path(output_type, Some(&module.name));
+            let output_path = cgcx.output_filenames.temp_path_for_cgu(
+                output_type,
+                &module.name,
+                cgcx.invocation_temp.as_deref(),
+            );
             load_from_incr_comp_dir(output_path, &saved_file)
         } else {
             None
@@ -1222,6 +1232,7 @@ fn start_executing_work<B: ExtraBackendMethods>(
         split_dwarf_kind: tcx.sess.opts.unstable_opts.split_dwarf_kind,
         parallel: backend.supports_parallel() && !sess.opts.unstable_opts.no_parallel_backend,
         pointer_size: tcx.data_layout.pointer_size,
+        invocation_temp: sess.invocation_temp.clone(),
     };
 
     // This is the "main loop" of parallel work happening for parallel codegen.

compiler/rustc_codegen_ssa/src/base.rs

@@ -10,7 +10,7 @@ use rustc_ast::expand::allocator::{ALLOCATOR_METHODS, AllocatorKind, global_fn_n
 use rustc_attr_parsing::OptimizeAttr;
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
-use rustc_data_structures::sync::par_map;
+use rustc_data_structures::sync::{IntoDynSyncSend, par_map};
 use rustc_data_structures::unord::UnordMap;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
@@ -640,8 +640,11 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         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 =
+            let file_name = tcx.output_filenames(()).temp_path_for_cgu(
-                tcx.output_filenames(()).temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
+                OutputType::Metadata,
+                &metadata_cgu_name,
+                tcx.sess.invocation_temp.as_deref(),
+            );
             let data = create_compressed_metadata_file(
                 tcx.sess,
                 &metadata,
@@ -757,7 +760,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
             let pre_compiled_cgus = par_map(cgus, |(i, _)| {
                 let module = backend.compile_codegen_unit(tcx, codegen_units[i].name());
-                (i, module)
+                (i, IntoDynSyncSend(module))
             });
 
             total_codegen_time += start_time.elapsed();
@@ -777,7 +780,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         match cgu_reuse {
             CguReuse::No => {
                 let (module, cost) = if let Some(cgu) = pre_compiled_cgus.remove(&i) {
-                    cgu
+                    cgu.0
                 } else {
                     let start_time = Instant::now();
                     let module = backend.compile_codegen_unit(tcx, cgu.name());

compiler/rustc_codegen_ssa/src/errors.rs

@@ -277,13 +277,13 @@ pub struct BinaryOutputToTty {
 #[derive(Diagnostic)]
 #[diag(codegen_ssa_ignoring_emit_path)]
 pub struct IgnoringEmitPath {
-    pub extension: String,
+    pub extension: &'static str,
 }
 
 #[derive(Diagnostic)]
 #[diag(codegen_ssa_ignoring_output)]
 pub struct IgnoringOutput {
-    pub extension: String,
+    pub extension: &'static str,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_codegen_ssa/src/lib.rs

@@ -105,13 +105,19 @@ impl<M> ModuleCodegen<M> {
         emit_asm: bool,
         emit_ir: bool,
         outputs: &OutputFilenames,
+        invocation_temp: Option<&str>,
     ) -> CompiledModule {
-        let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name)));
+        let object = emit_obj
-        let dwarf_object = emit_dwarf_obj.then(|| outputs.temp_path_dwo(Some(&self.name)));
+            .then(|| outputs.temp_path_for_cgu(OutputType::Object, &self.name, invocation_temp));
-        let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name)));
+        let dwarf_object =
-        let assembly = emit_asm.then(|| outputs.temp_path(OutputType::Assembly, Some(&self.name)));
+            emit_dwarf_obj.then(|| outputs.temp_path_dwo_for_cgu(&self.name, invocation_temp));
-        let llvm_ir =
+        let bytecode = emit_bc
-            emit_ir.then(|| outputs.temp_path(OutputType::LlvmAssembly, Some(&self.name)));
+            .then(|| outputs.temp_path_for_cgu(OutputType::Bitcode, &self.name, invocation_temp));
+        let assembly = emit_asm
+            .then(|| outputs.temp_path_for_cgu(OutputType::Assembly, &self.name, invocation_temp));
+        let llvm_ir = emit_ir.then(|| {
+            outputs.temp_path_for_cgu(OutputType::LlvmAssembly, &self.name, invocation_temp)
+        });
 
         CompiledModule {
             name: self.name.clone(),

compiler/rustc_data_structures/Cargo.toml

@@ -14,7 +14,7 @@ indexmap = "2.4.0"
 jobserver_crate = { version = "0.1.28", package = "jobserver" }
 measureme = "12.0.1"
 rustc-hash = "2.0.0"
-rustc-rayon = { version = "0.5.1", features = ["indexmap"] }
+rustc-rayon-core = { version = "0.5.0" }
 rustc-stable-hash = { version = "0.1.0", features = ["nightly"] }
 rustc_arena = { path = "../rustc_arena" }
 rustc_graphviz = { path = "../rustc_graphviz" }

compiler/rustc_data_structures/src/marker.rs

@@ -179,6 +179,12 @@ impl<T> FromDyn<T> {
         FromDyn(val)
     }
 
+    #[inline(always)]
+    pub fn derive<O>(&self, val: O) -> FromDyn<O> {
+        // We already did the check for `sync::is_dyn_thread_safe()` when creating `Self`
+        FromDyn(val)
+    }
+
     #[inline(always)]
     pub fn into_inner(self) -> T {
         self.0
@@ -200,6 +206,13 @@ impl<T> std::ops::Deref for FromDyn<T> {
     }
 }
 
+impl<T> std::ops::DerefMut for FromDyn<T> {
+    #[inline(always)]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
 // A wrapper to convert a struct that is already a `Send` or `Sync` into
 // an instance of `DynSend` and `DynSync`, since the compiler cannot infer
 // it automatically in some cases. (e.g. Box<dyn Send / Sync>)

compiler/rustc_data_structures/src/sync/freeze.rs

@@ -88,7 +88,7 @@ impl<T> FreezeLock<T> {
     #[inline]
     #[track_caller]
     pub fn write(&self) -> FreezeWriteGuard<'_, T> {
-        self.try_write().expect("still mutable")
+        self.try_write().expect("data should not be frozen if we're still attempting to mutate it")
     }
 
     #[inline]

compiler/rustc_data_structures/src/sync/parallel.rs

@@ -7,7 +7,6 @@ use std::any::Any;
 use std::panic::{AssertUnwindSafe, catch_unwind, resume_unwind};
 
 use parking_lot::Mutex;
-use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelIterator};
 
 use crate::FatalErrorMarker;
 use crate::sync::{DynSend, DynSync, FromDyn, IntoDynSyncSend, mode};
@@ -97,11 +96,11 @@ macro_rules! parallel {
 // This function only works when `mode::is_dyn_thread_safe()`.
 pub fn scope<'scope, OP, R>(op: OP) -> R
 where
-    OP: FnOnce(&rayon::Scope<'scope>) -> R + DynSend,
+    OP: FnOnce(&rayon_core::Scope<'scope>) -> R + DynSend,
     R: DynSend,
 {
     let op = FromDyn::from(op);
-    rayon::scope(|s| FromDyn::from(op.into_inner()(s))).into_inner()
+    rayon_core::scope(|s| FromDyn::from(op.into_inner()(s))).into_inner()
 }
 
 #[inline]
@@ -114,7 +113,7 @@ where
         let oper_a = FromDyn::from(oper_a);
         let oper_b = FromDyn::from(oper_b);
         let (a, b) = parallel_guard(|guard| {
-            rayon::join(
+            rayon_core::join(
                 move || guard.run(move || FromDyn::from(oper_a.into_inner()())),
                 move || guard.run(move || FromDyn::from(oper_b.into_inner()())),
             )
@@ -125,56 +124,103 @@ where
     }
 }
 
-pub fn par_for_each_in<I, T: IntoIterator<Item = I> + IntoParallelIterator<Item = I>>(
+fn par_slice<I: DynSend>(
+    items: &mut [I],
+    guard: &ParallelGuard,
+    for_each: impl Fn(&mut I) + DynSync + DynSend,
+) {
+    struct State<'a, F> {
+        for_each: FromDyn<F>,
+        guard: &'a ParallelGuard,
+        group: usize,
+    }
+
+    fn par_rec<I: DynSend, F: Fn(&mut I) + DynSync + DynSend>(
+        items: &mut [I],
+        state: &State<'_, F>,
+    ) {
+        if items.len() <= state.group {
+            for item in items {
+                state.guard.run(|| (state.for_each)(item));
+            }
+        } else {
+            let (left, right) = items.split_at_mut(items.len() / 2);
+            let mut left = state.for_each.derive(left);
+            let mut right = state.for_each.derive(right);
+            rayon_core::join(move || par_rec(*left, state), move || par_rec(*right, state));
+        }
+    }
+
+    let state = State {
+        for_each: FromDyn::from(for_each),
+        guard,
+        group: std::cmp::max(items.len() / 128, 1),
+    };
+    par_rec(items, &state)
+}
+
+pub fn par_for_each_in<I: DynSend, T: IntoIterator<Item = I>>(
     t: T,
-    for_each: impl Fn(I) + DynSync + DynSend,
+    for_each: impl Fn(&I) + DynSync + DynSend,
 ) {
     parallel_guard(|guard| {
         if mode::is_dyn_thread_safe() {
-            let for_each = FromDyn::from(for_each);
+            let mut items: Vec<_> = t.into_iter().collect();
-            t.into_par_iter().for_each(|i| {
+            par_slice(&mut items, guard, |i| for_each(&*i))
-                guard.run(|| for_each(i));
-            });
         } else {
             t.into_iter().for_each(|i| {
-                guard.run(|| for_each(i));
+                guard.run(|| for_each(&i));
             });
         }
     });
 }
 
-pub fn try_par_for_each_in<
+/// This runs `for_each` in parallel for each iterator item. If one or more of the
-    T: IntoIterator + IntoParallelIterator<Item = <T as IntoIterator>::Item>,
+/// `for_each` calls returns `Err`, the function will also return `Err`. The error returned
-    E: Send,
+/// will be non-deterministic, but this is expected to be used with `ErrorGuaranteed` which
->(
+/// are all equivalent.
+pub fn try_par_for_each_in<T: IntoIterator, E: DynSend>(
     t: T,
-    for_each: impl Fn(<T as IntoIterator>::Item) -> Result<(), E> + DynSync + DynSend,
+    for_each: impl Fn(&<T as IntoIterator>::Item) -> Result<(), E> + DynSync + DynSend,
-) -> Result<(), E> {
+) -> Result<(), E>
+where
+    <T as IntoIterator>::Item: DynSend,
+{
     parallel_guard(|guard| {
         if mode::is_dyn_thread_safe() {
-            let for_each = FromDyn::from(for_each);
+            let mut items: Vec<_> = t.into_iter().collect();
-            t.into_par_iter()
+
-                .filter_map(|i| guard.run(|| for_each(i)))
+            let error = Mutex::new(None);
-                .reduce(|| Ok(()), Result::and)
+
+            par_slice(&mut items, guard, |i| {
+                if let Err(err) = for_each(&*i) {
+                    *error.lock() = Some(err);
+                }
+            });
+
+            if let Some(err) = error.into_inner() { Err(err) } else { Ok(()) }
         } else {
-            t.into_iter().filter_map(|i| guard.run(|| for_each(i))).fold(Ok(()), Result::and)
+            t.into_iter().filter_map(|i| guard.run(|| for_each(&i))).fold(Ok(()), Result::and)
         }
     })
 }
 
-pub fn par_map<
+pub fn par_map<I: DynSend, T: IntoIterator<Item = I>, R: DynSend, C: FromIterator<R>>(
-    I,
-    T: IntoIterator<Item = I> + IntoParallelIterator<Item = I>,
-    R: std::marker::Send,
-    C: FromIterator<R> + FromParallelIterator<R>,
->(
     t: T,
     map: impl Fn(I) -> R + DynSync + DynSend,
 ) -> C {
     parallel_guard(|guard| {
         if mode::is_dyn_thread_safe() {
             let map = FromDyn::from(map);
-            t.into_par_iter().filter_map(|i| guard.run(|| map(i))).collect()
+
+            let mut items: Vec<(Option<I>, Option<R>)> =
+                t.into_iter().map(|i| (Some(i), None)).collect();
+
+            par_slice(&mut items, guard, |i| {
+                i.1 = Some(map(i.0.take().unwrap()));
+            });
+
+            items.into_iter().filter_map(|i| i.1).collect()
         } else {
             t.into_iter().filter_map(|i| guard.run(|| map(i))).collect()
         }

compiler/rustc_data_structures/src/unord.rs

@@ -109,6 +109,16 @@ impl<T, I: Iterator<Item = T>> UnordItems<T, I> {
     pub fn collect<C: From<UnordItems<T, I>>>(self) -> C {
         self.into()
     }
+
+    /// If the iterator has only one element, returns it, otherwise returns `None`.
+    #[track_caller]
+    pub fn get_only(mut self) -> Option<T> {
+        let item = self.0.next();
+        if self.0.next().is_some() {
+            return None;
+        }
+        item
+    }
 }
 
 impl<T> UnordItems<T, std::iter::Empty<T>> {

compiler/rustc_driver_impl/src/lib.rs

@@ -264,6 +264,7 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
         hash_untracked_state: None,
         register_lints: None,
         override_queries: None,
+        extra_symbols: Vec::new(),
         make_codegen_backend: None,
         registry: diagnostics_registry(),
         using_internal_features: &USING_INTERNAL_FEATURES,
@@ -348,10 +349,6 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
             // Make sure name resolution and macro expansion is run.
             let _ = tcx.resolver_for_lowering();
 
-            if let Some(metrics_dir) = &sess.opts.unstable_opts.metrics_dir {
-                dump_feature_usage_metrics(tcx, metrics_dir);
-            }
-
             if callbacks.after_expansion(compiler, tcx) == Compilation::Stop {
                 return early_exit();
             }
@@ -370,6 +367,10 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
 
             tcx.ensure_ok().analysis(());
 
+            if let Some(metrics_dir) = &sess.opts.unstable_opts.metrics_dir {
+                dump_feature_usage_metrics(tcx, metrics_dir);
+            }
+
             if callbacks.after_analysis(compiler, tcx) == Compilation::Stop {
                 return early_exit();
             }

compiler/rustc_error_codes/src/error_codes/E0622.md

@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 An intrinsic was declared without being a function.
 
 Erroneous code example:
 
-```compile_fail,E0622
+```no_run
 #![feature(intrinsics)]
 #![allow(internal_features)]
 

compiler/rustc_error_codes/src/lib.rs

@@ -397,7 +397,7 @@ E0618: 0618,
 E0619: 0619,
 E0620: 0620,
 E0621: 0621,
-E0622: 0622,
+E0622: 0622, // REMOVED: rustc-intrinsic ABI was removed
 E0623: 0623,
 E0624: 0624,
 E0625: 0625,

compiler/rustc_expand/src/base.rs

@@ -1102,7 +1102,7 @@ pub trait ResolverExpand {
     /// HIR proc macros items back to their harness items.
     fn declare_proc_macro(&mut self, id: NodeId);
 
-    fn append_stripped_cfg_item(&mut self, parent_node: NodeId, name: Ident, cfg: ast::MetaItem);
+    fn append_stripped_cfg_item(&mut self, parent_node: NodeId, ident: Ident, cfg: ast::MetaItem);
 
     /// Tools registered with `#![register_tool]` and used by tool attributes and lints.
     fn registered_tools(&self) -> &RegisteredTools;

compiler/rustc_expand/src/expand.rs

@@ -1169,9 +1169,9 @@ trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
         collector.cx.dcx().emit_err(RemoveNodeNotSupported { span, descr: Self::descr() });
     }
 
-    /// All of the names (items) declared by this node.
+    /// All of the identifiers (items) declared by this node.
     /// This is an approximation and should only be used for diagnostics.
-    fn declared_names(&self) -> Vec<Ident> {
+    fn declared_idents(&self) -> Vec<Ident> {
         vec![]
     }
 }
@@ -1306,7 +1306,7 @@ impl InvocationCollectorNode for P<ast::Item> {
         res
     }
 
-    fn declared_names(&self) -> Vec<Ident> {
+    fn declared_idents(&self) -> Vec<Ident> {
         if let ItemKind::Use(ut) = &self.kind {
             fn collect_use_tree_leaves(ut: &ast::UseTree, idents: &mut Vec<Ident>) {
                 match &ut.kind {
@@ -2061,10 +2061,10 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
                         }
 
                         if let Some(meta_item) = meta_item {
-                            for name in node.declared_names() {
+                            for ident in node.declared_idents() {
                                 self.cx.resolver.append_stripped_cfg_item(
                                     self.cx.current_expansion.lint_node_id,
-                                    name,
+                                    ident,
                                     meta_item.clone(),
                                 )
                             }

compiler/rustc_hir/src/def.rs

@@ -267,11 +267,16 @@ impl DefKind {
             | DefKind::ForeignTy
             | DefKind::TraitAlias
             | DefKind::TyParam
-            | DefKind::ExternCrate => DefPathData::TypeNs(Some(name.unwrap())),
+            | DefKind::ExternCrate => DefPathData::TypeNs(name.unwrap()),
 
-            // An associated type names will be missing for an RPITIT. It will
+            // An associated type name will be missing for an RPITIT.
-            // later be given a name with `synthetic` in it, if necessary.
+            DefKind::AssocTy => {
-            DefKind::AssocTy => DefPathData::TypeNs(name),
+                if let Some(name) = name {
+                    DefPathData::TypeNs(name)
+                } else {
+                    DefPathData::AnonAssocTy
+                }
+            }
 
             // It's not exactly an anon const, but wrt DefPathData, there
             // is no difference.

compiler/rustc_hir/src/definitions.rs

@@ -271,9 +271,8 @@ pub enum DefPathData {
     Use,
     /// A global asm item.
     GlobalAsm,
-    /// Something in the type namespace. Will be empty for RPITIT associated
+    /// Something in the type namespace.
-    /// types, which are given a synthetic name later, if necessary.
+    TypeNs(Symbol),
-    TypeNs(Option<Symbol>),
     /// Something in the value namespace.
     ValueNs(Symbol),
     /// Something in the macro namespace.
@@ -291,6 +290,8 @@ pub enum DefPathData {
     /// An existential `impl Trait` type node.
     /// Argument position `impl Trait` have a `TypeNs` with their pretty-printed name.
     OpaqueTy,
+    /// An anonymous associated type from an RPITIT.
+    AnonAssocTy,
     /// A synthetic body for a coroutine's by-move body.
     SyntheticCoroutineBody,
 }
@@ -413,9 +414,7 @@ impl DefPathData {
     pub fn get_opt_name(&self) -> Option<Symbol> {
         use self::DefPathData::*;
         match *self {
-            TypeNs(name) => name,
+            TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
-
-            ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
 
             Impl
             | ForeignMod
@@ -426,6 +425,7 @@ impl DefPathData {
             | Ctor
             | AnonConst
             | OpaqueTy
+            | AnonAssocTy
             | SyntheticCoroutineBody => None,
         }
     }
@@ -433,14 +433,9 @@ impl DefPathData {
     pub fn name(&self) -> DefPathDataName {
         use self::DefPathData::*;
         match *self {
-            TypeNs(name) => {
+            TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => {
-                if let Some(name) = name {
+                DefPathDataName::Named(name)
-                    DefPathDataName::Named(name)
-                } else {
-                    DefPathDataName::Anon { namespace: sym::synthetic }
-                }
             }
-            ValueNs(name) | MacroNs(name) | LifetimeNs(name) => DefPathDataName::Named(name),
             // Note that this does not show up in user print-outs.
             CrateRoot => DefPathDataName::Anon { namespace: kw::Crate },
             Impl => DefPathDataName::Anon { namespace: kw::Impl },
@@ -451,6 +446,7 @@ impl DefPathData {
             Ctor => DefPathDataName::Anon { namespace: sym::constructor },
             AnonConst => DefPathDataName::Anon { namespace: sym::constant },
             OpaqueTy => DefPathDataName::Anon { namespace: sym::opaque },
+            AnonAssocTy => DefPathDataName::Anon { namespace: sym::anon_assoc },
             SyntheticCoroutineBody => DefPathDataName::Anon { namespace: sym::synthetic },
         }
     }

compiler/rustc_hir/src/hir.rs

@@ -3399,9 +3399,9 @@ pub struct BareFnTy<'hir> {
     pub abi: ExternAbi,
     pub generic_params: &'hir [GenericParam<'hir>],
     pub decl: &'hir FnDecl<'hir>,
-    // `Option` because bare fn parameter names are optional. We also end up
+    // `Option` because bare fn parameter identifiers are optional. We also end up
     // with `None` in some error cases, e.g. invalid parameter patterns.
-    pub param_names: &'hir [Option<Ident>],
+    pub param_idents: &'hir [Option<Ident>],
 }
 
 #[derive(Debug, Clone, Copy, HashStable_Generic)]

compiler/rustc_hir/src/intravisit.rs

@@ -652,10 +652,10 @@ pub fn walk_foreign_item<'v, V: Visitor<'v>>(
     try_visit!(visitor.visit_ident(foreign_item.ident));
 
     match foreign_item.kind {
-        ForeignItemKind::Fn(ref sig, param_names, ref generics) => {
+        ForeignItemKind::Fn(ref sig, param_idents, ref generics) => {
             try_visit!(visitor.visit_generics(generics));
             try_visit!(visitor.visit_fn_decl(sig.decl));
-            for ident in param_names.iter().copied() {
+            for ident in param_idents.iter().copied() {
                 visit_opt!(visitor, visit_ident, ident);
             }
         }
@@ -1169,9 +1169,9 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(
             try_visit!(visitor.visit_ty_unambig(ty));
             visit_opt!(visitor, visit_nested_body, default);
         }
-        TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
+        TraitItemKind::Fn(ref sig, TraitFn::Required(param_idents)) => {
             try_visit!(visitor.visit_fn_decl(sig.decl));
-            for ident in param_names.iter().copied() {
+            for ident in param_idents.iter().copied() {
                 visit_opt!(visitor, visit_ident, ident);
             }
         }

compiler/rustc_hir/src/tests.rs

@@ -17,7 +17,7 @@ fn def_path_hash_depends_on_crate_id() {
     // the crate by changing the crate disambiguator (e.g. via bumping the
     // crate's version number).
 
-    create_session_globals_then(Edition::Edition2024, None, || {
+    create_session_globals_then(Edition::Edition2024, &[], None, || {
         let id0 = StableCrateId::new(Symbol::intern("foo"), false, vec!["1".to_string()], "");
         let id1 = StableCrateId::new(Symbol::intern("foo"), false, vec!["2".to_string()], "");
 

compiler/rustc_hir_analysis/messages.ftl

@@ -1,5 +1,5 @@
-hir_analysis_ambiguous_assoc_item = ambiguous associated {$assoc_kind} `{$assoc_name}` in bounds of `{$qself}`
+hir_analysis_ambiguous_assoc_item = ambiguous associated {$assoc_kind} `{$assoc_ident}` in bounds of `{$qself}`
-    .label = ambiguous associated {$assoc_kind} `{$assoc_name}`
+    .label = ambiguous associated {$assoc_kind} `{$assoc_ident}`
 
 hir_analysis_ambiguous_lifetime_bound =
     ambiguous lifetime bound, explicit lifetime bound required
@@ -12,13 +12,13 @@ hir_analysis_assoc_item_is_private = {$kind} `{$name}` is private
     .label = private {$kind}
     .defined_here_label = the {$kind} is defined here
 
-hir_analysis_assoc_item_not_found = associated {$assoc_kind} `{$assoc_name}` not found for `{$qself}`
+hir_analysis_assoc_item_not_found = associated {$assoc_kind} `{$assoc_ident}` not found for `{$qself}`
 
 hir_analysis_assoc_item_not_found_found_in_other_trait_label = there is {$identically_named ->
         [true] an
         *[false] a similarly named
     } associated {$assoc_kind} `{$suggested_name}` in the trait `{$trait_name}`
-hir_analysis_assoc_item_not_found_label = associated {$assoc_kind} `{$assoc_name}` not found
+hir_analysis_assoc_item_not_found_label = associated {$assoc_kind} `{$assoc_ident}` not found
 hir_analysis_assoc_item_not_found_other_sugg = `{$qself}` has the following associated {$assoc_kind}
 hir_analysis_assoc_item_not_found_similar_in_other_trait_qpath_sugg =
     consider fully qualifying{$identically_named ->

compiler/rustc_hir_analysis/src/check/check.rs

@@ -719,7 +719,6 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                     def_id,
                     tcx.def_ident_span(def_id).unwrap(),
                     i.name,
-                    ExternAbi::Rust,
                 )
             }
         }
@@ -787,16 +786,6 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             for item in items {
                 let def_id = item.id.owner_id.def_id;
 
-                if tcx.has_attr(def_id, sym::rustc_intrinsic) {
-                    intrinsic::check_intrinsic_type(
-                        tcx,
-                        item.id.owner_id.def_id,
-                        item.span,
-                        item.ident.name,
-                        abi,
-                    );
-                }
-
                 let generics = tcx.generics_of(def_id);
                 let own_counts = generics.own_counts();
                 if generics.own_params.len() - own_counts.lifetimes != 0 {

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -1046,11 +1046,11 @@ fn report_trait_method_mismatch<'tcx>(
             // argument pattern and type.
             let (sig, body) = tcx.hir_expect_impl_item(impl_m.def_id.expect_local()).expect_fn();
             let span = tcx
-                .hir_body_param_names(body)
+                .hir_body_param_idents(body)
                 .zip(sig.decl.inputs.iter())
-                .map(|(param_name, ty)| {
+                .map(|(param_ident, ty)| {
-                    if let Some(param_name) = param_name {
+                    if let Some(param_ident) = param_ident {
-                        param_name.span.to(ty.span)
+                        param_ident.span.to(ty.span)
                     } else {
                         ty.span
                     }

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -1,9 +1,8 @@
 //! Type-checking for the `#[rustc_intrinsic]` intrinsics that the compiler exposes.
 
 use rustc_abi::ExternAbi;
-use rustc_errors::codes::*;
+use rustc_errors::DiagMessage;
-use rustc_errors::{DiagMessage, struct_span_code_err};
+use rustc_hir::{self as hir};
-use rustc_hir::{self as hir, Safety};
 use rustc_middle::bug;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -26,17 +25,10 @@ fn equate_intrinsic_type<'tcx>(
     sig: ty::PolyFnSig<'tcx>,
 ) {
     let (generics, span) = match tcx.hir_node_by_def_id(def_id) {
-        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { generics, .. }, .. })
+        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { generics, .. }, .. }) => {
-        | hir::Node::ForeignItem(hir::ForeignItem {
+            (tcx.generics_of(def_id), generics.span)
-            kind: hir::ForeignItemKind::Fn(_, _, generics),
-            ..
-        }) => (tcx.generics_of(def_id), generics.span),
-        _ => {
-            struct_span_code_err!(tcx.dcx(), span, E0622, "intrinsic must be a function")
-                .with_span_label(span, "expected a function")
-                .emit();
-            return;
         }
+        _ => tcx.dcx().span_bug(span, "intrinsic must be a function"),
     };
     let own_counts = generics.own_counts();
 
@@ -70,13 +62,7 @@ fn equate_intrinsic_type<'tcx>(
 }
 
 /// Returns the unsafety of the given intrinsic.
-pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hir::Safety {
+fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hir::Safety {
-    let has_safe_attr = if tcx.has_attr(intrinsic_id, sym::rustc_intrinsic) {
-        tcx.fn_sig(intrinsic_id).skip_binder().safety()
-    } else {
-        // Old-style intrinsics are never safe
-        Safety::Unsafe
-    };
     let is_in_list = match tcx.item_name(intrinsic_id.into()) {
         // When adding a new intrinsic to this list,
         // it's usually worth updating that intrinsic's documentation
@@ -148,7 +134,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
         _ => hir::Safety::Unsafe,
     };
 
-    if has_safe_attr != is_in_list {
+    if tcx.fn_sig(intrinsic_id).skip_binder().safety() != is_in_list {
         tcx.dcx().struct_span_err(
             tcx.def_span(intrinsic_id),
             DiagMessage::from(format!(
@@ -163,12 +149,11 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
 
 /// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
 /// and in `library/core/src/intrinsics.rs`.
-pub fn check_intrinsic_type(
+pub(crate) fn check_intrinsic_type(
     tcx: TyCtxt<'_>,
     intrinsic_id: LocalDefId,
     span: Span,
     intrinsic_name: Symbol,
-    abi: ExternAbi,
 ) {
     let generics = tcx.generics_of(intrinsic_id);
     let param = |n| {
@@ -674,8 +659,12 @@ pub fn check_intrinsic_type(
             sym::simd_masked_load => (3, 0, vec![param(0), param(1), param(2)], param(2)),
             sym::simd_masked_store => (3, 0, vec![param(0), param(1), param(2)], tcx.types.unit),
             sym::simd_scatter => (3, 0, vec![param(0), param(1), param(2)], tcx.types.unit),
-            sym::simd_insert => (2, 0, vec![param(0), tcx.types.u32, param(1)], param(0)),
+            sym::simd_insert | sym::simd_insert_dyn => {
-            sym::simd_extract => (2, 0, vec![param(0), tcx.types.u32], param(1)),
+                (2, 0, vec![param(0), tcx.types.u32, param(1)], param(0))
+            }
+            sym::simd_extract | sym::simd_extract_dyn => {
+                (2, 0, vec![param(0), tcx.types.u32], param(1))
+            }
             sym::simd_cast
             | sym::simd_as
             | sym::simd_cast_ptr
@@ -706,7 +695,7 @@ pub fn check_intrinsic_type(
         };
         (n_tps, 0, n_cts, inputs, output, safety)
     };
-    let sig = tcx.mk_fn_sig(inputs, output, false, safety, abi);
+    let sig = tcx.mk_fn_sig(inputs, output, false, safety, ExternAbi::Rust);
     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
     equate_intrinsic_type(tcx, span, intrinsic_id, n_tps, n_lts, n_cts, sig)
 }

compiler/rustc_hir_analysis/src/collect.rs

@@ -439,9 +439,9 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> {
         &self,
         span: Span,
         def_id: LocalDefId,
-        assoc_name: Ident,
+        assoc_ident: Ident,
     ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
-        self.tcx.at(span).type_param_predicates((self.item_def_id, def_id, assoc_name))
+        self.tcx.at(span).type_param_predicates((self.item_def_id, def_id, assoc_ident))
     }
 
     fn lower_assoc_shared(

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -584,12 +584,12 @@ pub(super) fn explicit_super_predicates_of<'tcx>(
 
 pub(super) fn explicit_supertraits_containing_assoc_item<'tcx>(
     tcx: TyCtxt<'tcx>,
-    (trait_def_id, assoc_name): (DefId, Ident),
+    (trait_def_id, assoc_ident): (DefId, Ident),
 ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(
         tcx,
         trait_def_id,
-        PredicateFilter::SelfTraitThatDefines(assoc_name),
+        PredicateFilter::SelfTraitThatDefines(assoc_ident),
     )
 }
 
@@ -617,7 +617,7 @@ pub(super) fn implied_predicates_with_filter<'tcx>(
     filter: PredicateFilter,
 ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     let Some(trait_def_id) = trait_def_id.as_local() else {
-        // if `assoc_name` is None, then the query should've been redirected to an
+        // if `assoc_ident` is None, then the query should've been redirected to an
         // external provider
         assert_matches!(filter, PredicateFilter::SelfTraitThatDefines(_));
         return tcx.explicit_super_predicates_of(trait_def_id);
@@ -834,11 +834,11 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>(
 #[instrument(level = "trace", skip(tcx))]
 pub(super) fn type_param_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
-    (item_def_id, def_id, assoc_name): (LocalDefId, LocalDefId, Ident),
+    (item_def_id, def_id, assoc_ident): (LocalDefId, LocalDefId, Ident),
 ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     match tcx.opt_rpitit_info(item_def_id.to_def_id()) {
         Some(ty::ImplTraitInTraitData::Trait { opaque_def_id, .. }) => {
-            return tcx.type_param_predicates((opaque_def_id.expect_local(), def_id, assoc_name));
+            return tcx.type_param_predicates((opaque_def_id.expect_local(), def_id, assoc_ident));
         }
         Some(ty::ImplTraitInTraitData::Impl { .. }) => {
             unreachable!("should not be lowering bounds on RPITIT in impl")
@@ -863,7 +863,7 @@ pub(super) fn type_param_predicates<'tcx>(
 
     let result = if let Some(parent) = parent {
         let icx = ItemCtxt::new(tcx, parent);
-        icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_name)
+        icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_ident)
     } else {
         ty::EarlyBinder::bind(&[] as &[_])
     };
@@ -889,7 +889,7 @@ pub(super) fn type_param_predicates<'tcx>(
     let extra_predicates = extend.into_iter().chain(icx.probe_ty_param_bounds_in_generics(
         hir_generics,
         def_id,
-        PredicateFilter::SelfTraitThatDefines(assoc_name),
+        PredicateFilter::SelfTraitThatDefines(assoc_ident),
     ));
 
     let bounds =
@@ -908,7 +908,7 @@ pub(super) fn type_param_predicates<'tcx>(
         _ => unreachable!(),
     };
     assert_only_contains_predicates_from(
-        PredicateFilter::SelfTraitThatDefines(assoc_name),
+        PredicateFilter::SelfTraitThatDefines(assoc_ident),
         bounds,
         self_ty,
     );

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1874,13 +1874,13 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
     fn supertrait_hrtb_vars(
         tcx: TyCtxt<'tcx>,
         def_id: DefId,
-        assoc_name: Ident,
+        assoc_ident: Ident,
         assoc_kind: ty::AssocKind,
     ) -> Option<(Vec<ty::BoundVariableKind>, &'tcx ty::AssocItem)> {
         let trait_defines_associated_item_named = |trait_def_id: DefId| {
-            tcx.associated_items(trait_def_id).find_by_name_and_kind(
+            tcx.associated_items(trait_def_id).find_by_ident_and_kind(
                 tcx,
-                assoc_name,
+                assoc_ident,
                 assoc_kind,
                 trait_def_id,
             )
@@ -1904,7 +1904,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
             if let Some(assoc_item) = trait_defines_associated_item_named(def_id) {
                 break Some((bound_vars.into_iter().collect(), assoc_item));
             }
-            let predicates = tcx.explicit_supertraits_containing_assoc_item((def_id, assoc_name));
+            let predicates = tcx.explicit_supertraits_containing_assoc_item((def_id, assoc_ident));
             let obligations = predicates.iter_identity_copied().filter_map(|(pred, _)| {
                 let bound_predicate = pred.kind();
                 match bound_predicate.skip_binder() {

compiler/rustc_hir_analysis/src/errors.rs

@@ -23,7 +23,7 @@ pub(crate) struct AmbiguousAssocItem<'a> {
     #[label]
     pub span: Span,
     pub assoc_kind: &'static str,
-    pub assoc_name: Ident,
+    pub assoc_ident: Ident,
     pub qself: &'a str,
 }
 
@@ -75,7 +75,7 @@ pub(crate) struct AssocItemIsPrivate {
 pub(crate) struct AssocItemNotFound<'a> {
     #[primary_span]
     pub span: Span,
-    pub assoc_name: Ident,
+    pub assoc_ident: Ident,
     pub assoc_kind: &'static str,
     pub qself: &'a str,
     #[subdiagnostic]

compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs

@@ -363,10 +363,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         for hir_bound in hir_bounds {
             // In order to avoid cycles, when we're lowering `SelfTraitThatDefines`,
             // we skip over any traits that don't define the given associated type.
-            if let PredicateFilter::SelfTraitThatDefines(assoc_name) = predicate_filter {
+            if let PredicateFilter::SelfTraitThatDefines(assoc_ident) = predicate_filter {
                 if let Some(trait_ref) = hir_bound.trait_ref()
                     && let Some(trait_did) = trait_ref.trait_def_id()
-                    && self.tcx().trait_may_define_assoc_item(trait_did, assoc_name)
+                    && self.tcx().trait_may_define_assoc_item(trait_did, assoc_ident)
                 {
                     // Okay
                 } else {

compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs

@@ -49,13 +49,13 @@ pub(crate) fn validate_cmse_abi<'tcx>(
                 Ok(Err(index)) => {
                     // fn(x: u32, u32, u32, u16, y: u16) -> u32,
                     //                           ^^^^^^
-                    let span = if let Some(ident) = bare_fn_ty.param_names[index] {
+                    let span = if let Some(ident) = bare_fn_ty.param_idents[index] {
                         ident.span.to(bare_fn_ty.decl.inputs[index].span)
                     } else {
                         bare_fn_ty.decl.inputs[index].span
                     }
                     .to(bare_fn_ty.decl.inputs.last().unwrap().span);
-                    let plural = bare_fn_ty.param_names.len() - index != 1;
+                    let plural = bare_fn_ty.param_idents.len() - index != 1;
                     dcx.emit_err(errors::CmseInputsStackSpill { span, plural, abi });
                 }
                 Err(layout_err) => {

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -117,7 +117,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         all_candidates: impl Fn() -> I,
         qself: AssocItemQSelf,
         assoc_kind: ty::AssocKind,
-        assoc_name: Ident,
+        assoc_ident: Ident,
         span: Span,
         constraint: Option<&hir::AssocItemConstraint<'tcx>>,
     ) -> ErrorGuaranteed
@@ -129,11 +129,15 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // First and foremost, provide a more user-friendly & “intuitive” error on kind mismatches.
         if let Some(assoc_item) = all_candidates().find_map(|r| {
             tcx.associated_items(r.def_id())
-                .filter_by_name_unhygienic(assoc_name.name)
+                .filter_by_name_unhygienic(assoc_ident.name)
-                .find(|item| tcx.hygienic_eq(assoc_name, item.ident(tcx), r.def_id()))
+                .find(|item| tcx.hygienic_eq(assoc_ident, item.ident(tcx), r.def_id()))
         }) {
             return self.complain_about_assoc_kind_mismatch(
-                assoc_item, assoc_kind, assoc_name, span, constraint,
+                assoc_item,
+                assoc_kind,
+                assoc_ident,
+                span,
+                constraint,
             );
         }
 
@@ -142,18 +146,18 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
         // The fallback span is needed because `assoc_name` might be an `Fn()`'s `Output` without a
         // valid span, so we point at the whole path segment instead.
-        let is_dummy = assoc_name.span == DUMMY_SP;
+        let is_dummy = assoc_ident.span == DUMMY_SP;
 
         let mut err = errors::AssocItemNotFound {
-            span: if is_dummy { span } else { assoc_name.span },
+            span: if is_dummy { span } else { assoc_ident.span },
-            assoc_name,
+            assoc_ident,
             assoc_kind: assoc_kind_str,
             qself: &qself_str,
             label: None,
             sugg: None,
             // Try to get the span of the identifier within the path's syntax context
             // (if that's different).
-            within_macro_span: assoc_name.span.within_macro(span, tcx.sess.source_map()),
+            within_macro_span: assoc_ident.span.within_macro(span, tcx.sess.source_map()),
         };
 
         if is_dummy {
@@ -169,10 +173,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             .collect();
 
         if let Some(suggested_name) =
-            find_best_match_for_name(&all_candidate_names, assoc_name.name, None)
+            find_best_match_for_name(&all_candidate_names, assoc_ident.name, None)
         {
             err.sugg = Some(errors::AssocItemNotFoundSugg::Similar {
-                span: assoc_name.span,
+                span: assoc_ident.span,
                 assoc_kind: assoc_kind_str,
                 suggested_name,
             });
@@ -201,7 +205,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             .collect();
 
         if let Some(suggested_name) =
-            find_best_match_for_name(&wider_candidate_names, assoc_name.name, None)
+            find_best_match_for_name(&wider_candidate_names, assoc_ident.name, None)
         {
             if let [best_trait] = visible_traits
                 .iter()
@@ -215,11 +219,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             {
                 let trait_name = tcx.def_path_str(best_trait);
                 err.label = Some(errors::AssocItemNotFoundLabel::FoundInOtherTrait {
-                    span: assoc_name.span,
+                    span: assoc_ident.span,
                     assoc_kind: assoc_kind_str,
                     trait_name: &trait_name,
                     suggested_name,
-                    identically_named: suggested_name == assoc_name.name,
+                    identically_named: suggested_name == assoc_ident.name,
                 });
                 if let AssocItemQSelf::TyParam(ty_param_def_id, ty_param_span) = qself
                     // Not using `self.item_def_id()` here as that would yield the opaque type itself if we're
@@ -246,7 +250,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         // The type param already has a bound for `trait_name`, we just need to
                         // change the associated item.
                         err.sugg = Some(errors::AssocItemNotFoundSugg::SimilarInOtherTrait {
-                            span: assoc_name.span,
+                            span: assoc_ident.span,
                             assoc_kind: assoc_kind_str,
                             suggested_name,
                         });
@@ -265,7 +269,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         Applicability::MaybeIncorrect
                     };
 
-                    let identically_named = suggested_name == assoc_name.name;
+                    let identically_named = suggested_name == assoc_ident.name;
 
                     if let DefKind::TyAlias = tcx.def_kind(item_def_id)
                         && !tcx.type_alias_is_lazy(item_def_id)
@@ -273,7 +277,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         err.sugg = Some(errors::AssocItemNotFoundSugg::SimilarInOtherTraitQPath {
                             lo: ty_param_span.shrink_to_lo(),
                             mi: ty_param_span.shrink_to_hi(),
-                            hi: (!identically_named).then_some(assoc_name.span),
+                            hi: (!identically_named).then_some(assoc_ident.span),
                             trait_ref,
                             identically_named,
                             suggested_name,
@@ -294,7 +298,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                             // We suggested constraining a type parameter, but the associated item on it
                             // was also not an exact match, so we also suggest changing it.
                             err.span_suggestion_verbose(
-                                assoc_name.span,
+                                assoc_ident.span,
                                 fluent::hir_analysis_assoc_item_not_found_similar_in_other_trait_with_bound_sugg,
                                 suggested_name,
                                 Applicability::MaybeIncorrect,
@@ -311,13 +315,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // suggest using it.
         if let [candidate_name] = all_candidate_names.as_slice() {
             err.sugg = Some(errors::AssocItemNotFoundSugg::Other {
-                span: assoc_name.span,
+                span: assoc_ident.span,
                 qself: &qself_str,
                 assoc_kind: assoc_kind_str,
                 suggested_name: *candidate_name,
             });
         } else {
-            err.label = Some(errors::AssocItemNotFoundLabel::NotFound { span: assoc_name.span });
+            err.label = Some(errors::AssocItemNotFoundLabel::NotFound { span: assoc_ident.span });
         }
 
         self.dcx().emit_err(err)
@@ -805,7 +809,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         return None;
                     };
 
-                    let assoc_item = tcx.associated_items(trait_def).find_by_name_and_kind(
+                    let assoc_item = tcx.associated_items(trait_def).find_by_ident_and_kind(
                         tcx,
                         ident,
                         ty::AssocKind::Type,

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -147,7 +147,7 @@ pub trait HirTyLowerer<'tcx> {
         &self,
         span: Span,
         def_id: LocalDefId,
-        assoc_name: Ident,
+        assoc_ident: Ident,
     ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]>;
 
     /// Lower an associated type/const (from a trait) to a projection.
@@ -933,11 +933,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         &self,
         trait_def_id: DefId,
         assoc_kind: ty::AssocKind,
-        assoc_name: Ident,
+        assoc_ident: Ident,
     ) -> bool {
         self.tcx()
             .associated_items(trait_def_id)
-            .find_by_name_and_kind(self.tcx(), assoc_name, assoc_kind, trait_def_id)
+            .find_by_ident_and_kind(self.tcx(), assoc_ident, assoc_kind, trait_def_id)
             .is_some()
     }
 
@@ -964,7 +964,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     }
 
     /// Search for a trait bound on a type parameter whose trait defines the associated item
-    /// given by `assoc_name` and `kind`.
+    /// given by `assoc_ident` and `kind`.
     ///
     /// This fails if there is no such bound in the list of candidates or if there are multiple
     /// candidates in which case it reports ambiguity.
@@ -976,13 +976,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         ty_param_def_id: LocalDefId,
         ty_param_span: Span,
         kind: ty::AssocKind,
-        assoc_name: Ident,
+        assoc_ident: Ident,
         span: Span,
     ) -> Result<ty::PolyTraitRef<'tcx>, ErrorGuaranteed> {
-        debug!(?ty_param_def_id, ?assoc_name, ?span);
+        debug!(?ty_param_def_id, ?assoc_ident, ?span);
         let tcx = self.tcx();
 
-        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name);
+        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_ident);
         debug!("predicates={:#?}", predicates);
 
         self.probe_single_bound_for_assoc_item(
@@ -990,17 +990,18 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 let trait_refs = predicates
                     .iter_identity_copied()
                     .filter_map(|(p, _)| Some(p.as_trait_clause()?.map_bound(|t| t.trait_ref)));
-                traits::transitive_bounds_that_define_assoc_item(tcx, trait_refs, assoc_name)
+                traits::transitive_bounds_that_define_assoc_item(tcx, trait_refs, assoc_ident)
             },
             AssocItemQSelf::TyParam(ty_param_def_id, ty_param_span),
             kind,
-            assoc_name,
+            assoc_ident,
             span,
             None,
         )
     }
 
-    /// Search for a single trait bound whose trait defines the associated item given by `assoc_name`.
+    /// Search for a single trait bound whose trait defines the associated item given by
+    /// `assoc_ident`.
     ///
     /// This fails if there is no such bound in the list of candidates or if there are multiple
     /// candidates in which case it reports ambiguity.
@@ -1010,7 +1011,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         all_candidates: impl Fn() -> I,
         qself: AssocItemQSelf,
         assoc_kind: ty::AssocKind,
-        assoc_name: Ident,
+        assoc_ident: Ident,
         span: Span,
         constraint: Option<&hir::AssocItemConstraint<'tcx>>,
     ) -> Result<ty::PolyTraitRef<'tcx>, ErrorGuaranteed>
@@ -1020,7 +1021,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let tcx = self.tcx();
 
         let mut matching_candidates = all_candidates().filter(|r| {
-            self.probe_trait_that_defines_assoc_item(r.def_id(), assoc_kind, assoc_name)
+            self.probe_trait_that_defines_assoc_item(r.def_id(), assoc_kind, assoc_ident)
         });
 
         let Some(bound) = matching_candidates.next() else {
@@ -1028,7 +1029,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 all_candidates,
                 qself,
                 assoc_kind,
-                assoc_name,
+                assoc_ident,
                 span,
                 constraint,
             );
@@ -1044,7 +1045,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             let mut err = self.dcx().create_err(crate::errors::AmbiguousAssocItem {
                 span,
                 assoc_kind: assoc_kind_str,
-                assoc_name,
+                assoc_ident,
                 qself: &qself_str,
             });
             // Provide a more specific error code index entry for equality bindings.
@@ -1065,13 +1066,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 let bound_id = bound.def_id();
                 let bound_span = tcx
                     .associated_items(bound_id)
-                    .find_by_name_and_kind(tcx, assoc_name, assoc_kind, bound_id)
+                    .find_by_ident_and_kind(tcx, assoc_ident, assoc_kind, bound_id)
                     .and_then(|item| tcx.hir_span_if_local(item.def_id));
 
                 if let Some(bound_span) = bound_span {
                     err.span_label(
                         bound_span,
-                        format!("ambiguous `{assoc_name}` from `{}`", bound.print_trait_sugared(),),
+                        format!("ambiguous `{assoc_ident}` from `{}`", bound.print_trait_sugared(),),
                     );
                     if let Some(constraint) = constraint {
                         match constraint.kind {
@@ -1087,7 +1088,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                                 }
                                 // FIXME(#97583): This isn't syntactically well-formed!
                                 where_bounds.push(format!(
-                                    "        T: {trait}::{assoc_name} = {term}",
+                                    "        T: {trait}::{assoc_ident} = {term}",
                                     trait = bound.print_only_trait_path(),
                                 ));
                             }
@@ -1096,7 +1097,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         }
                     } else {
                         err.span_suggestion_verbose(
-                            span.with_hi(assoc_name.span.lo()),
+                            span.with_hi(assoc_ident.span.lo()),
                             "use fully-qualified syntax to disambiguate",
                             format!("<{qself_str} as {}>::", bound.print_only_trait_path()),
                             Applicability::MaybeIncorrect,
@@ -1104,7 +1105,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     }
                 } else {
                     err.note(format!(
-                        "associated {assoc_kind_str} `{assoc_name}` could derive from `{}`",
+                        "associated {assoc_kind_str} `{assoc_ident}` could derive from `{}`",
                         bound.print_only_trait_path(),
                     ));
                 }
@@ -2858,7 +2859,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
         let trait_ref = self.lower_impl_trait_ref(i.of_trait.as_ref()?, self.lower_ty(i.self_ty));
 
-        let assoc = tcx.associated_items(trait_ref.def_id).find_by_name_and_kind(
+        let assoc = tcx.associated_items(trait_ref.def_id).find_by_ident_and_kind(
             tcx,
             *ident,
             ty::AssocKind::Fn,

compiler/rustc_hir_pretty/src/lib.rs

@@ -397,7 +397,7 @@ impl<'a> State<'a> {
                 self.pclose();
             }
             hir::TyKind::BareFn(f) => {
-                self.print_ty_fn(f.abi, f.safety, f.decl, None, f.generic_params, f.param_names);
+                self.print_ty_fn(f.abi, f.safety, f.decl, None, f.generic_params, f.param_idents);
             }
             hir::TyKind::UnsafeBinder(unsafe_binder) => {
                 self.print_unsafe_binder(unsafe_binder);
@@ -473,14 +473,14 @@ impl<'a> State<'a> {
         self.maybe_print_comment(item.span.lo());
         self.print_attrs_as_outer(self.attrs(item.hir_id()));
         match item.kind {
-            hir::ForeignItemKind::Fn(sig, arg_names, generics) => {
+            hir::ForeignItemKind::Fn(sig, arg_idents, generics) => {
                 self.head("");
                 self.print_fn(
                     sig.decl,
                     sig.header,
                     Some(item.ident.name),
                     generics,
-                    arg_names,
+                    arg_idents,
                     None,
                 );
                 self.end(); // end head-ibox
@@ -899,10 +899,10 @@ impl<'a> State<'a> {
         ident: Ident,
         m: &hir::FnSig<'_>,
         generics: &hir::Generics<'_>,
-        arg_names: &[Option<Ident>],
+        arg_idents: &[Option<Ident>],
         body_id: Option<hir::BodyId>,
     ) {
-        self.print_fn(m.decl, m.header, Some(ident.name), generics, arg_names, body_id);
+        self.print_fn(m.decl, m.header, Some(ident.name), generics, arg_idents, body_id);
     }
 
     fn print_trait_item(&mut self, ti: &hir::TraitItem<'_>) {
@@ -914,8 +914,8 @@ impl<'a> State<'a> {
             hir::TraitItemKind::Const(ty, default) => {
                 self.print_associated_const(ti.ident, ti.generics, ty, default);
             }
-            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(arg_names)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(arg_idents)) => {
-                self.print_method_sig(ti.ident, sig, ti.generics, arg_names, None);
+                self.print_method_sig(ti.ident, sig, ti.generics, arg_idents, None);
                 self.word(";");
             }
             hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
@@ -2122,7 +2122,7 @@ impl<'a> State<'a> {
         header: hir::FnHeader,
         name: Option<Symbol>,
         generics: &hir::Generics<'_>,
-        arg_names: &[Option<Ident>],
+        arg_idents: &[Option<Ident>],
         body_id: Option<hir::BodyId>,
     ) {
         self.print_fn_header_info(header);
@@ -2134,16 +2134,16 @@ impl<'a> State<'a> {
         self.print_generic_params(generics.params);
 
         self.popen();
-        // Make sure we aren't supplied *both* `arg_names` and `body_id`.
+        // Make sure we aren't supplied *both* `arg_idents` and `body_id`.
-        assert!(arg_names.is_empty() || body_id.is_none());
+        assert!(arg_idents.is_empty() || body_id.is_none());
         let mut i = 0;
         let mut print_arg = |s: &mut Self, ty: Option<&hir::Ty<'_>>| {
             if i == 0 && decl.implicit_self.has_implicit_self() {
                 s.print_implicit_self(&decl.implicit_self);
             } else {
-                if let Some(arg_name) = arg_names.get(i) {
+                if let Some(arg_ident) = arg_idents.get(i) {
-                    if let Some(arg_name) = arg_name {
+                    if let Some(arg_ident) = arg_ident {
-                        s.word(arg_name.to_string());
+                        s.word(arg_ident.to_string());
                         s.word(":");
                         s.space();
                     }
@@ -2452,7 +2452,7 @@ impl<'a> State<'a> {
         decl: &hir::FnDecl<'_>,
         name: Option<Symbol>,
         generic_params: &[hir::GenericParam<'_>],
-        arg_names: &[Option<Ident>],
+        arg_idents: &[Option<Ident>],
     ) {
         self.ibox(INDENT_UNIT);
         self.print_formal_generic_params(generic_params);
@@ -2467,7 +2467,7 @@ impl<'a> State<'a> {
             },
             name,
             generics,
-            arg_names,
+            arg_idents,
             None,
         );
         self.end();

compiler/rustc_hir_typeck/messages.ftl

@@ -148,7 +148,7 @@ hir_typeck_never_type_fallback_flowing_into_unsafe_path = never type fallback af
 hir_typeck_never_type_fallback_flowing_into_unsafe_union_field = never type fallback affects this union access
     .help = specify the type explicitly
 
-hir_typeck_no_associated_item = no {$item_kind} named `{$item_name}` found for {$ty_prefix} `{$ty_str}`{$trait_missing_method ->
+hir_typeck_no_associated_item = no {$item_kind} named `{$item_ident}` found for {$ty_prefix} `{$ty_str}`{$trait_missing_method ->
     [true] {""}
     *[other] {" "}in the current scope
 }

compiler/rustc_hir_typeck/src/errors.rs

@@ -727,7 +727,7 @@ pub(crate) struct NoAssociatedItem {
     #[primary_span]
     pub span: Span,
     pub item_kind: &'static str,
-    pub item_name: Ident,
+    pub item_ident: Ident,
     pub ty_prefix: Cow<'static, str>,
     pub ty_str: String,
     pub trait_missing_method: bool,

compiler/rustc_hir_typeck/src/expr.rs

@@ -2920,8 +2920,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
         // We failed to check the expression, report an error.
 
-        // Emits an error if we deref an infer variable, like calling `.field` on a base type of &_.
+        // Emits an error if we deref an infer variable, like calling `.field` on a base type
-        self.structurally_resolve_type(autoderef.span(), autoderef.final_ty(false));
+        // of `&_`. We can also use this to suppress unnecessary "missing field" errors that
+        // will follow ambiguity errors.
+        let final_ty = self.structurally_resolve_type(autoderef.span(), autoderef.final_ty(false));
+        if let ty::Error(_) = final_ty.kind() {
+            return final_ty;
+        }
 
         if let Some((adjustments, did)) = private_candidate {
             // (#90483) apply adjustments to avoid ExprUseVisitor from

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -1136,7 +1136,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 && let self_implicit =
                     matches!(call_expr.kind, hir::ExprKind::MethodCall(..)) as usize
                 && let Some(Some(arg)) =
-                    self.tcx.fn_arg_names(fn_def_id).get(expected_idx.as_usize() + self_implicit)
+                    self.tcx.fn_arg_idents(fn_def_id).get(expected_idx.as_usize() + self_implicit)
                 && arg.name != kw::SelfLower
             {
                 format!("/* {} */", arg.name)
@@ -2619,7 +2619,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         is_method: bool,
     ) -> Option<(IndexVec<ExpectedIdx, (Option<GenericIdx>, FnParam<'_>)>, &hir::Generics<'_>)>
     {
-        let (sig, generics, body_id, param_names) = match self.tcx.hir_get_if_local(def_id)? {
+        let (sig, generics, body_id, params) = match self.tcx.hir_get_if_local(def_id)? {
             hir::Node::TraitItem(&hir::TraitItem {
                 generics,
                 kind: hir::TraitItemKind::Fn(sig, trait_fn),
@@ -2661,7 +2661,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 None
             }
         });
-        match (body_id, param_names) {
+        match (body_id, params) {
             (Some(_), Some(_)) | (None, None) => unreachable!(),
             (Some(body), None) => {
                 let params = self.tcx.hir_body(body).params;
@@ -2678,7 +2678,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     params.get(is_method as usize..params.len() - sig.decl.c_variadic as usize)?;
                 debug_assert_eq!(params.len(), fn_inputs.len());
                 Some((
-                    fn_inputs.zip(params.iter().map(|&ident| FnParam::Name(ident))).collect(),
+                    fn_inputs.zip(params.iter().map(|&ident| FnParam::Ident(ident))).collect(),
                     generics,
                 ))
             }
@@ -2709,14 +2709,14 @@ impl<'tcx> Visitor<'tcx> for FindClosureArg<'tcx> {
 #[derive(Clone, Copy)]
 enum FnParam<'hir> {
     Param(&'hir hir::Param<'hir>),
-    Name(Option<Ident>),
+    Ident(Option<Ident>),
 }
 
 impl FnParam<'_> {
     fn span(&self) -> Span {
         match self {
             Self::Param(param) => param.span,
-            Self::Name(ident) => {
+            Self::Ident(ident) => {
                 if let Some(ident) = ident {
                     ident.span
                 } else {
@@ -2738,7 +2738,7 @@ impl FnParam<'_> {
                     {
                         Some(ident.name)
                     }
-                    FnParam::Name(ident)
+                    FnParam::Ident(ident)
                         if let Some(ident) = ident
                             && ident.name != kw::Underscore =>
                     {

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -534,12 +534,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         Ok((def_kind, pick.item.def_id))
     }
 
-    /// Finds item with name `item_name` defined in impl/trait `def_id`
+    /// Finds item with name `item_ident` defined in impl/trait `def_id`
     /// and return it, or `None`, if no such item was defined there.
-    fn associated_value(&self, def_id: DefId, item_name: Ident) -> Option<ty::AssocItem> {
+    fn associated_value(&self, def_id: DefId, item_ident: Ident) -> Option<ty::AssocItem> {
         self.tcx
             .associated_items(def_id)
-            .find_by_name_and_namespace(self.tcx, item_name, Namespace::ValueNS, def_id)
+            .find_by_ident_and_namespace(self.tcx, item_ident, Namespace::ValueNS, def_id)
             .copied()
     }
 }

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -585,7 +585,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         mut span: Span,
         rcvr_ty: Ty<'tcx>,
-        item_name: Ident,
+        item_ident: Ident,
         expr_id: hir::HirId,
         source: SelfSource<'tcx>,
         args: Option<&'tcx [hir::Expr<'tcx>]>,
@@ -616,7 +616,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else if rcvr_ty.is_enum() {
             "variant or associated item"
         } else {
-            match (item_name.as_str().chars().next(), rcvr_ty.is_fresh_ty()) {
+            match (item_ident.as_str().chars().next(), rcvr_ty.is_fresh_ty()) {
                 (Some(name), false) if name.is_lowercase() => "function or associated item",
                 (Some(_), false) => "associated item",
                 (Some(_), true) | (None, false) => "variant or associated item",
@@ -631,7 +631,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             rcvr_ty,
             source,
             span,
-            item_name,
+            item_ident,
             &short_ty_str,
             &mut ty_file,
         ) {
@@ -643,13 +643,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             source,
             span,
             item_kind,
-            item_name,
+            item_ident,
             &short_ty_str,
             &mut ty_file,
         ) {
             return guar;
         }
-        span = item_name.span;
+        span = item_ident.span;
 
         // Don't show generic arguments when the method can't be found in any implementation (#81576).
         let mut ty_str_reported = ty_str.clone();
@@ -661,7 +661,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         self.tcx
                             .inherent_impls(adt_def.did())
                             .into_iter()
-                            .any(|def_id| self.associated_value(*def_id, item_name).is_some())
+                            .any(|def_id| self.associated_value(*def_id, item_ident).is_some())
                     } else {
                         false
                     }
@@ -678,14 +678,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let is_write = sugg_span.ctxt().outer_expn_data().macro_def_id.is_some_and(|def_id| {
             tcx.is_diagnostic_item(sym::write_macro, def_id)
                 || tcx.is_diagnostic_item(sym::writeln_macro, def_id)
-        }) && item_name.name == sym::write_fmt;
+        }) && item_ident.name == sym::write_fmt;
         let mut err = if is_write && let SelfSource::MethodCall(rcvr_expr) = source {
             self.suggest_missing_writer(rcvr_ty, rcvr_expr)
         } else {
             let mut err = self.dcx().create_err(NoAssociatedItem {
                 span,
                 item_kind,
-                item_name,
+                item_ident,
                 ty_prefix: if trait_missing_method {
                     // FIXME(mu001999) E0599 maybe not suitable here because it is for types
                     Cow::from("trait")
@@ -699,7 +699,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             if is_method {
                 self.suggest_use_shadowed_binding_with_method(
                     source,
-                    item_name,
+                    item_ident,
                     &ty_str_reported,
                     &mut err,
                 );
@@ -710,9 +710,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 && let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind
                 && let Res::SelfTyAlias { alias_to: impl_def_id, .. } = path.res
                 && let DefKind::Impl { .. } = self.tcx.def_kind(impl_def_id)
-                && let Some(candidate) = tcx.associated_items(impl_def_id).find_by_name_and_kind(
+                && let Some(candidate) = tcx.associated_items(impl_def_id).find_by_ident_and_kind(
                     self.tcx,
-                    item_name,
+                    item_ident,
                     ty::AssocKind::Type,
                     impl_def_id,
                 )
@@ -722,7 +722,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             {
                 let def_path = tcx.def_path_str(adt_def.did());
                 err.span_suggestion(
-                    ty.span.to(item_name.span),
+                    ty.span.to(item_ident.span),
                     format!("to construct a value of type `{}`, use the explicit path", def_path),
                     def_path,
                     Applicability::MachineApplicable,
@@ -750,7 +750,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.find_builder_fn(&mut err, rcvr_ty, expr_id);
         }
 
-        if tcx.ty_is_opaque_future(rcvr_ty) && item_name.name == sym::poll {
+        if tcx.ty_is_opaque_future(rcvr_ty) && item_ident.name == sym::poll {
             err.help(format!(
                 "method `poll` found on `Pin<&mut {ty_str}>`, \
                 see documentation for `std::pin::Pin`"
@@ -765,7 +765,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         {
             self.suggest_await_before_method(
                 &mut err,
-                item_name,
+                item_ident,
                 rcvr_ty,
                 cal,
                 span,
@@ -787,7 +787,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if let SelfSource::MethodCall(rcvr_expr) = source
             && let ty::RawPtr(ty, ptr_mutbl) = *rcvr_ty.kind()
             && let Ok(pick) = self.lookup_probe_for_diagnostic(
-                item_name,
+                item_ident,
                 Ty::new_ref(tcx, ty::Region::new_error_misc(tcx), ty, ptr_mutbl),
                 self.tcx.hir_expect_expr(self.tcx.parent_hir_id(rcvr_expr.hir_id)),
                 ProbeScope::TraitsInScope,
@@ -808,7 +808,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             };
             err.span_note(
                 tcx.def_span(pick.item.def_id),
-                format!("the method `{item_name}` exists on the type `{ty}`", ty = pick.self_ty),
+                format!("the method `{item_ident}` exists on the type `{ty}`", ty = pick.self_ty),
             );
             let mut_str = ptr_mutbl.ptr_str();
             err.note(format!(
@@ -834,7 +834,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.suggest_fn_call(&mut err, rcvr_expr, rcvr_ty, |output_ty| {
                 let call_expr = self.tcx.hir_expect_expr(self.tcx.parent_hir_id(rcvr_expr.hir_id));
                 let probe = self.lookup_probe_for_diagnostic(
-                    item_name,
+                    item_ident,
                     output_ty,
                     call_expr,
                     ProbeScope::AllTraits,
@@ -873,13 +873,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 static_candidates,
                 rcvr_ty,
                 source,
-                item_name,
+                item_ident,
                 args,
                 sugg_span,
             );
             self.note_candidates_on_method_error(
                 rcvr_ty,
-                item_name,
+                item_ident,
                 source,
                 args,
                 span,
@@ -890,7 +890,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else if static_candidates.len() > 1 {
             self.note_candidates_on_method_error(
                 rcvr_ty,
-                item_name,
+                item_ident,
                 source,
                 args,
                 span,
@@ -904,7 +904,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut restrict_type_params = false;
         let mut suggested_derive = false;
         let mut unsatisfied_bounds = false;
-        if item_name.name == sym::count && self.is_slice_ty(rcvr_ty, span) {
+        if item_ident.name == sym::count && self.is_slice_ty(rcvr_ty, span) {
             let msg = "consider using `len` instead";
             if let SelfSource::MethodCall(_expr) = source {
                 err.span_suggestion_short(span, msg, "len", Applicability::MachineApplicable);
@@ -1349,7 +1349,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 };
                 let primary_message = primary_message.unwrap_or_else(|| {
                     format!(
-                        "the {item_kind} `{item_name}` exists for {actual_prefix} `{ty_str}`, \
+                        "the {item_kind} `{item_ident}` exists for {actual_prefix} `{ty_str}`, \
                          but its trait bounds were not satisfied"
                     )
                 });
@@ -1379,7 +1379,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // `Pin<&Self>`.
             if targs.len() == 1 {
                 let mut item_segment = hir::PathSegment::invalid();
-                item_segment.ident = item_name;
+                item_segment.ident = item_ident;
                 for t in [Ty::new_mut_ref, Ty::new_imm_ref, |_, _, t| t] {
                     let new_args =
                         tcx.mk_args_from_iter(targs.iter().map(|arg| match arg.as_type() {
@@ -1423,9 +1423,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     ty::Adt(adt, _) => self.tcx.is_lang_item(adt.did(), LangItem::String),
                     _ => false,
                 };
-                if is_string_or_ref_str && item_name.name == sym::iter {
+                if is_string_or_ref_str && item_ident.name == sym::iter {
                     err.span_suggestion_verbose(
-                        item_name.span,
+                        item_ident.span,
                         "because of the in-memory representation of `&str`, to obtain \
                          an `Iterator` over each of its codepoint use method `chars`",
                         "chars",
@@ -1439,7 +1439,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .into_iter()
                         .copied()
                         .filter(|def_id| {
-                            if let Some(assoc) = self.associated_value(*def_id, item_name) {
+                            if let Some(assoc) = self.associated_value(*def_id, item_ident) {
                                 // Check for both mode is the same so we avoid suggesting
                                 // incorrect associated item.
                                 match (mode, assoc.fn_has_self_parameter, source) {
@@ -1500,7 +1500,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // If the method name is the name of a field with a function or closure type,
         // give a helping note that it has to be called as `(x.f)(...)`.
         if let SelfSource::MethodCall(expr) = source {
-            if !self.suggest_calling_field_as_fn(span, rcvr_ty, expr, item_name, &mut err)
+            if !self.suggest_calling_field_as_fn(span, rcvr_ty, expr, item_ident, &mut err)
                 && similar_candidate.is_none()
                 && !custom_span_label
             {
@@ -1513,7 +1513,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let confusable_suggested = self.confusable_method_name(
             &mut err,
             rcvr_ty,
-            item_name,
+            item_ident,
             args.map(|args| {
                 args.iter()
                     .map(|expr| {
@@ -1531,12 +1531,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 source,
                 span,
                 rcvr_ty,
-                item_name,
+                item_ident,
                 expected.only_has_type(self),
             );
         }
 
-        self.suggest_unwrapping_inner_self(&mut err, source, rcvr_ty, item_name);
+        self.suggest_unwrapping_inner_self(&mut err, source, rcvr_ty, item_ident);
 
         for (span, mut bounds) in bound_spans {
             if !tcx.sess.source_map().is_span_accessible(span) {
@@ -1547,7 +1547,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let pre = if Some(span) == ty_span {
                 ty_span.take();
                 format!(
-                    "{item_kind} `{item_name}` not found for this {} because it ",
+                    "{item_kind} `{item_ident}` not found for this {} because it ",
                     rcvr_ty.prefix_string(self.tcx)
                 )
             } else {
@@ -1567,7 +1567,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             err.span_label(
                 span,
                 format!(
-                    "{item_kind} `{item_name}` not found for this {}",
+                    "{item_kind} `{item_ident}` not found for this {}",
                     rcvr_ty.prefix_string(self.tcx)
                 ),
             );
@@ -1579,7 +1579,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 &mut err,
                 span,
                 rcvr_ty,
-                item_name,
+                item_ident,
                 args.map(|args| args.len() + 1),
                 source,
                 no_match_data.out_of_scope_traits.clone(),
@@ -1596,7 +1596,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let adt_def = rcvr_ty.ty_adt_def().expect("enum is not an ADT");
             if let Some(var_name) = edit_distance::find_best_match_for_name(
                 &adt_def.variants().iter().map(|s| s.name).collect::<Vec<_>>(),
-                item_name.name,
+                item_ident.name,
                 None,
             ) && let Some(variant) = adt_def.variants().iter().find(|s| s.name == var_name)
             {
@@ -1737,14 +1737,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if !find_candidate_for_method {
             self.lookup_segments_chain_for_no_match_method(
                 &mut err,
-                item_name,
+                item_ident,
                 item_kind,
                 source,
                 no_match_data,
             );
         }
 
-        self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_name, expected);
+        self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_ident, expected);
         err.emit()
     }
 

compiler/rustc_hir_typeck/src/pat.rs

@@ -163,9 +163,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 enum AdjustMode {
     /// Peel off all immediate reference types.
     Peel,
-    /// Reset binding mode to the initial mode.
-    /// Used for destructuring assignment, where we don't want any match ergonomics.
-    Reset,
     /// Pass on the input binding mode and expected type.
     Pass,
 }
@@ -321,77 +318,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Conversely, inside this module, `check_pat_top` should never be used.
     #[instrument(level = "debug", skip(self, pat_info))]
     fn check_pat(&self, pat: &'tcx Pat<'tcx>, expected: Ty<'tcx>, pat_info: PatInfo<'tcx>) {
-        let PatInfo { binding_mode, max_ref_mutbl, top_info: ti, current_depth, .. } = pat_info;
+        let opt_path_res = match pat.kind {
-
-        let path_res = match pat.kind {
             PatKind::Expr(PatExpr { kind: PatExprKind::Path(qpath), hir_id, span }) => {
                 Some(self.resolve_ty_and_res_fully_qualified_call(qpath, *hir_id, *span))
             }
             _ => None,
         };
-        let adjust_mode = self.calc_adjust_mode(pat, path_res.map(|(res, ..)| res));
+        let adjust_mode = self.calc_adjust_mode(pat, opt_path_res.map(|(res, ..)| res));
-        let (expected, binding_mode, max_ref_mutbl) =
+        let ty = self.check_pat_inner(pat, opt_path_res, adjust_mode, expected, pat_info);
-            self.calc_default_binding_mode(pat, expected, binding_mode, adjust_mode, max_ref_mutbl);
-        let pat_info = PatInfo {
-            binding_mode,
-            max_ref_mutbl,
-            top_info: ti,
-            decl_origin: pat_info.decl_origin,
-            current_depth: current_depth + 1,
-        };
-
-        let ty = match pat.kind {
-            PatKind::Missing | PatKind::Wild | PatKind::Err(_) => expected,
-            // We allow any type here; we ensure that the type is uninhabited during match checking.
-            PatKind::Never => expected,
-            PatKind::Expr(PatExpr { kind: PatExprKind::Path(qpath), hir_id, span }) => {
-                let ty = self.check_pat_path(
-                    *hir_id,
-                    pat.hir_id,
-                    *span,
-                    qpath,
-                    path_res.unwrap(),
-                    expected,
-                    &pat_info.top_info,
-                );
-                self.write_ty(*hir_id, ty);
-                ty
-            }
-            PatKind::Expr(lt) => self.check_pat_lit(pat.span, lt, expected, &pat_info.top_info),
-            PatKind::Range(lhs, rhs, _) => {
-                self.check_pat_range(pat.span, lhs, rhs, expected, &pat_info.top_info)
-            }
-            PatKind::Binding(ba, var_id, ident, sub) => {
-                self.check_pat_ident(pat, ba, var_id, ident, sub, expected, pat_info)
-            }
-            PatKind::TupleStruct(ref qpath, subpats, ddpos) => {
-                self.check_pat_tuple_struct(pat, qpath, subpats, ddpos, expected, pat_info)
-            }
-            PatKind::Struct(ref qpath, fields, has_rest_pat) => {
-                self.check_pat_struct(pat, qpath, fields, has_rest_pat, expected, pat_info)
-            }
-            PatKind::Guard(pat, cond) => {
-                self.check_pat(pat, expected, pat_info);
-                self.check_expr_has_type_or_error(cond, self.tcx.types.bool, |_| {});
-                expected
-            }
-            PatKind::Or(pats) => {
-                for pat in pats {
-                    self.check_pat(pat, expected, pat_info);
-                }
-                expected
-            }
-            PatKind::Tuple(elements, ddpos) => {
-                self.check_pat_tuple(pat.span, elements, ddpos, expected, pat_info)
-            }
-            PatKind::Box(inner) => self.check_pat_box(pat.span, inner, expected, pat_info),
-            PatKind::Deref(inner) => self.check_pat_deref(pat.span, inner, expected, pat_info),
-            PatKind::Ref(inner, mutbl) => self.check_pat_ref(pat, inner, mutbl, expected, pat_info),
-            PatKind::Slice(before, slice, after) => {
-                self.check_pat_slice(pat.span, before, slice, after, expected, pat_info)
-            }
-        };
-
         self.write_ty(pat.hir_id, ty);
 
         // (note_1): In most of the cases where (note_1) is referenced
@@ -437,27 +371,126 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // `regions-relate-bound-regions-on-closures-to-inference-variables.rs`,
     }
 
-    /// Compute the new expected type and default binding mode from the old ones
+    // Helper to avoid resolving the same path pattern several times.
-    /// as well as the pattern form we are currently checking.
+    fn check_pat_inner(
-    fn calc_default_binding_mode(
         &self,
         pat: &'tcx Pat<'tcx>,
-        expected: Ty<'tcx>,
+        opt_path_res: Option<(Res, Option<LoweredTy<'tcx>>, &'tcx [hir::PathSegment<'tcx>])>,
-        def_br: ByRef,
         adjust_mode: AdjustMode,
-        max_ref_mutbl: MutblCap,
+        expected: Ty<'tcx>,
-    ) -> (Ty<'tcx>, ByRef, MutblCap) {
+        pat_info: PatInfo<'tcx>,
+    ) -> Ty<'tcx> {
         #[cfg(debug_assertions)]
-        if def_br == ByRef::Yes(Mutability::Mut)
+        if pat_info.binding_mode == ByRef::Yes(Mutability::Mut)
-            && max_ref_mutbl != MutblCap::Mut
+            && pat_info.max_ref_mutbl != MutblCap::Mut
             && self.downgrade_mut_inside_shared()
         {
             span_bug!(pat.span, "Pattern mutability cap violated!");
         }
-        match adjust_mode {
+
-            AdjustMode::Pass => (expected, def_br, max_ref_mutbl),
+        // Resolve type if needed.
-            AdjustMode::Reset => (expected, ByRef::No, MutblCap::Mut),
+        let expected = if let AdjustMode::Peel = adjust_mode
-            AdjustMode::Peel => self.peel_off_references(pat, expected, def_br, max_ref_mutbl),
+            && pat.default_binding_modes
+        {
+            self.try_structurally_resolve_type(pat.span, expected)
+        } else {
+            expected
+        };
+        let old_pat_info = pat_info;
+        let pat_info = PatInfo { current_depth: old_pat_info.current_depth + 1, ..old_pat_info };
+
+        match pat.kind {
+            // Peel off a `&` or `&mut` from the scrutinee type. See the examples in
+            // `tests/ui/rfcs/rfc-2005-default-binding-mode`.
+            _ if let AdjustMode::Peel = adjust_mode
+                && pat.default_binding_modes
+                && let ty::Ref(_, inner_ty, inner_mutability) = *expected.kind() =>
+            {
+                debug!("inspecting {:?}", expected);
+
+                debug!("current discriminant is Ref, inserting implicit deref");
+                // Preserve the reference type. We'll need it later during THIR lowering.
+                self.typeck_results
+                    .borrow_mut()
+                    .pat_adjustments_mut()
+                    .entry(pat.hir_id)
+                    .or_default()
+                    .push(expected);
+
+                let mut binding_mode = ByRef::Yes(match pat_info.binding_mode {
+                    // If default binding mode is by value, make it `ref` or `ref mut`
+                    // (depending on whether we observe `&` or `&mut`).
+                    ByRef::No |
+                    // When `ref mut`, stay a `ref mut` (on `&mut`) or downgrade to `ref` (on `&`).
+                    ByRef::Yes(Mutability::Mut) => inner_mutability,
+                    // Once a `ref`, always a `ref`.
+                    // This is because a `& &mut` cannot mutate the underlying value.
+                    ByRef::Yes(Mutability::Not) => Mutability::Not,
+                });
+
+                let mut max_ref_mutbl = pat_info.max_ref_mutbl;
+                if self.downgrade_mut_inside_shared() {
+                    binding_mode = binding_mode.cap_ref_mutability(max_ref_mutbl.as_mutbl());
+                }
+                if binding_mode == ByRef::Yes(Mutability::Not) {
+                    max_ref_mutbl = MutblCap::Not;
+                }
+                debug!("default binding mode is now {:?}", binding_mode);
+
+                // Use the old pat info to keep `current_depth` to its old value.
+                let new_pat_info = PatInfo { binding_mode, max_ref_mutbl, ..old_pat_info };
+                // Recurse with the new expected type.
+                self.check_pat_inner(pat, opt_path_res, adjust_mode, inner_ty, new_pat_info)
+            }
+            PatKind::Missing | PatKind::Wild | PatKind::Err(_) => expected,
+            // We allow any type here; we ensure that the type is uninhabited during match checking.
+            PatKind::Never => expected,
+            PatKind::Expr(PatExpr { kind: PatExprKind::Path(qpath), hir_id, span }) => {
+                let ty = self.check_pat_path(
+                    *hir_id,
+                    pat.hir_id,
+                    *span,
+                    qpath,
+                    opt_path_res.unwrap(),
+                    expected,
+                    &pat_info.top_info,
+                );
+                self.write_ty(*hir_id, ty);
+                ty
+            }
+            PatKind::Expr(lt) => self.check_pat_lit(pat.span, lt, expected, &pat_info.top_info),
+            PatKind::Range(lhs, rhs, _) => {
+                self.check_pat_range(pat.span, lhs, rhs, expected, &pat_info.top_info)
+            }
+            PatKind::Binding(ba, var_id, ident, sub) => {
+                self.check_pat_ident(pat, ba, var_id, ident, sub, expected, pat_info)
+            }
+            PatKind::TupleStruct(ref qpath, subpats, ddpos) => {
+                self.check_pat_tuple_struct(pat, qpath, subpats, ddpos, expected, pat_info)
+            }
+            PatKind::Struct(ref qpath, fields, has_rest_pat) => {
+                self.check_pat_struct(pat, qpath, fields, has_rest_pat, expected, pat_info)
+            }
+            PatKind::Guard(pat, cond) => {
+                self.check_pat(pat, expected, pat_info);
+                self.check_expr_has_type_or_error(cond, self.tcx.types.bool, |_| {});
+                expected
+            }
+            PatKind::Or(pats) => {
+                for pat in pats {
+                    self.check_pat(pat, expected, pat_info);
+                }
+                expected
+            }
+            PatKind::Tuple(elements, ddpos) => {
+                self.check_pat_tuple(pat.span, elements, ddpos, expected, pat_info)
+            }
+            PatKind::Box(inner) => self.check_pat_box(pat.span, inner, expected, pat_info),
+            PatKind::Deref(inner) => self.check_pat_deref(pat.span, inner, expected, pat_info),
+            PatKind::Ref(inner, mutbl) => self.check_pat_ref(pat, inner, mutbl, expected, pat_info),
+            PatKind::Slice(before, slice, after) => {
+                self.check_pat_slice(pat.span, before, slice, after, expected, pat_info)
+            }
         }
     }
 
@@ -465,11 +498,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ///
     /// When the pattern is a path pattern, `opt_path_res` must be `Some(res)`.
     fn calc_adjust_mode(&self, pat: &'tcx Pat<'tcx>, opt_path_res: Option<Res>) -> AdjustMode {
-        // When we perform destructuring assignment, we disable default match bindings, which are
-        // unintuitive in this context.
-        if !pat.default_binding_modes {
-            return AdjustMode::Reset;
-        }
         match &pat.kind {
             // Type checking these product-like types successfully always require
             // that the expected type be of those types and not reference types.
@@ -526,64 +554,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    /// Peel off as many immediately nested `& mut?` from the expected type as possible
-    /// and return the new expected type and binding default binding mode.
-    /// The adjustments vector, if non-empty is stored in a table.
-    fn peel_off_references(
-        &self,
-        pat: &'tcx Pat<'tcx>,
-        expected: Ty<'tcx>,
-        mut def_br: ByRef,
-        mut max_ref_mutbl: MutblCap,
-    ) -> (Ty<'tcx>, ByRef, MutblCap) {
-        let mut expected = self.try_structurally_resolve_type(pat.span, expected);
-        // Peel off as many `&` or `&mut` from the scrutinee type as possible. For example,
-        // for `match &&&mut Some(5)` the loop runs three times, aborting when it reaches
-        // the `Some(5)` which is not of type Ref.
-        //
-        // For each ampersand peeled off, update the binding mode and push the original
-        // type into the adjustments vector.
-        //
-        // See the examples in `ui/match-defbm*.rs`.
-        let mut pat_adjustments = vec![];
-        while let ty::Ref(_, inner_ty, inner_mutability) = *expected.kind() {
-            debug!("inspecting {:?}", expected);
-
-            debug!("current discriminant is Ref, inserting implicit deref");
-            // Preserve the reference type. We'll need it later during THIR lowering.
-            pat_adjustments.push(expected);
-
-            expected = self.try_structurally_resolve_type(pat.span, inner_ty);
-            def_br = ByRef::Yes(match def_br {
-                // If default binding mode is by value, make it `ref` or `ref mut`
-                // (depending on whether we observe `&` or `&mut`).
-                ByRef::No |
-                // When `ref mut`, stay a `ref mut` (on `&mut`) or downgrade to `ref` (on `&`).
-                ByRef::Yes(Mutability::Mut) => inner_mutability,
-                // Once a `ref`, always a `ref`.
-                // This is because a `& &mut` cannot mutate the underlying value.
-                ByRef::Yes(Mutability::Not) => Mutability::Not,
-            });
-        }
-
-        if self.downgrade_mut_inside_shared() {
-            def_br = def_br.cap_ref_mutability(max_ref_mutbl.as_mutbl());
-        }
-        if def_br == ByRef::Yes(Mutability::Not) {
-            max_ref_mutbl = MutblCap::Not;
-        }
-
-        if !pat_adjustments.is_empty() {
-            debug!("default binding mode is now {:?}", def_br);
-            self.typeck_results
-                .borrow_mut()
-                .pat_adjustments_mut()
-                .insert(pat.hir_id, pat_adjustments);
-        }
-
-        (expected, def_br, max_ref_mutbl)
-    }
-
     fn check_pat_expr_unadjusted(&self, lt: &'tcx hir::PatExpr<'tcx>) -> Ty<'tcx> {
         let ty = match &lt.kind {
             rustc_hir::PatExprKind::Lit { lit, negated } => {

compiler/rustc_interface/Cargo.toml

@@ -5,7 +5,6 @@ edition = "2024"
 
 [dependencies]
 # tidy-alphabetical-start
-rustc-rayon = { version = "0.5.0" }
 rustc-rayon-core = { version = "0.5.0" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_lowering = { path = "../rustc_ast_lowering" }

compiler/rustc_interface/src/interface.rs

@@ -348,6 +348,10 @@ pub struct Config {
     /// the list of queries.
     pub override_queries: Option<fn(&Session, &mut Providers)>,
 
+    /// An extra set of symbols to add to the symbol interner, the symbol indices
+    /// will start at [`PREDEFINED_SYMBOLS_COUNT`](rustc_span::symbol::PREDEFINED_SYMBOLS_COUNT)
+    pub extra_symbols: Vec<&'static str>,
+
     /// This is a callback from the driver that is called to create a codegen backend.
     ///
     /// Has no uses within this repository, but is used by bjorn3 for "the
@@ -409,6 +413,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
         &early_dcx,
         config.opts.edition,
         config.opts.unstable_opts.threads,
+        &config.extra_symbols,
         SourceMapInputs { file_loader, path_mapping, hash_kind, checksum_hash_kind },
         |current_gcx| {
             // The previous `early_dcx` can't be reused here because it doesn't

compiler/rustc_interface/src/passes.rs

@@ -800,6 +800,7 @@ pub fn create_and_enter_global_ctxt<T, F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> T>(
         sess.opts.cg.metadata.clone(),
         sess.cfg_version,
     );
+
     let outputs = util::build_output_filenames(&pre_configured_attrs, sess);
 
     let dep_type = DepsType { dep_names: rustc_query_impl::dep_kind_names() };

compiler/rustc_interface/src/tests.rs

@@ -53,7 +53,7 @@ where
         checksum_hash_kind,
     });
 
-    rustc_span::create_session_globals_then(DEFAULT_EDITION, sm_inputs, || {
+    rustc_span::create_session_globals_then(DEFAULT_EDITION, &[], sm_inputs, || {
         let temps_dir = sessopts.unstable_opts.temps_dir.as_deref().map(PathBuf::from);
         let io = CompilerIO {
             input: Input::Str { name: FileName::Custom(String::new()), input: String::new() },

compiler/rustc_interface/src/util.rs

@@ -117,6 +117,7 @@ fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
     thread_stack_size: usize,
     edition: Edition,
     sm_inputs: SourceMapInputs,
+    extra_symbols: &[&'static str],
     f: F,
 ) -> R {
     // The "thread pool" is a single spawned thread in the non-parallel
@@ -134,9 +135,12 @@ fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
         // name contains null bytes.
         let r = builder
             .spawn_scoped(s, move || {
-                rustc_span::create_session_globals_then(edition, Some(sm_inputs), || {
+                rustc_span::create_session_globals_then(
-                    f(CurrentGcx::new())
+                    edition,
-                })
+                    extra_symbols,
+                    Some(sm_inputs),
+                    || f(CurrentGcx::new()),
+                )
             })
             .unwrap()
             .join();
@@ -152,6 +156,7 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
     thread_builder_diag: &EarlyDiagCtxt,
     edition: Edition,
     threads: usize,
+    extra_symbols: &[&'static str],
     sm_inputs: SourceMapInputs,
     f: F,
 ) -> R {
@@ -168,18 +173,24 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
     let registry = sync::Registry::new(std::num::NonZero::new(threads).unwrap());
 
     if !sync::is_dyn_thread_safe() {
-        return run_in_thread_with_globals(thread_stack_size, edition, sm_inputs, |current_gcx| {
+        return run_in_thread_with_globals(
-            // Register the thread for use with the `WorkerLocal` type.
+            thread_stack_size,
-            registry.register();
+            edition,
+            sm_inputs,
+            extra_symbols,
+            |current_gcx| {
+                // Register the thread for use with the `WorkerLocal` type.
+                registry.register();
 
-            f(current_gcx)
+                f(current_gcx)
-        });
+            },
+        );
     }
 
     let current_gcx = FromDyn::from(CurrentGcx::new());
     let current_gcx2 = current_gcx.clone();
 
-    let builder = rayon::ThreadPoolBuilder::new()
+    let builder = rayon_core::ThreadPoolBuilder::new()
         .thread_name(|_| "rustc".to_string())
         .acquire_thread_handler(jobserver::acquire_thread)
         .release_thread_handler(jobserver::release_thread)
@@ -230,13 +241,13 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
     // pool. Upon creation, each worker thread created gets a copy of the
     // session globals in TLS. This is possible because `SessionGlobals` impls
     // `Send` in the parallel compiler.
-    rustc_span::create_session_globals_then(edition, Some(sm_inputs), || {
+    rustc_span::create_session_globals_then(edition, extra_symbols, Some(sm_inputs), || {
         rustc_span::with_session_globals(|session_globals| {
             let session_globals = FromDyn::from(session_globals);
             builder
                 .build_scoped(
                     // Initialize each new worker thread when created.
-                    move |thread: rayon::ThreadBuilder| {
+                    move |thread: rayon_core::ThreadBuilder| {
                         // Register the thread for use with the `WorkerLocal` type.
                         registry.register();
 
@@ -245,7 +256,9 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
                         })
                     },
                     // Run `f` on the first thread in the thread pool.
-                    move |pool: &rayon::ThreadPool| pool.install(|| f(current_gcx.into_inner())),
+                    move |pool: &rayon_core::ThreadPool| {
+                        pool.install(|| f(current_gcx.into_inner()))
+                    },
                 )
                 .unwrap()
         })

compiler/rustc_lint/src/context.rs

@@ -859,7 +859,7 @@ impl<'tcx> LateContext<'tcx> {
     ) -> Option<Ty<'tcx>> {
         let tcx = self.tcx;
         tcx.associated_items(trait_id)
-            .find_by_name_and_kind(tcx, Ident::from_str(name), ty::AssocKind::Type, trait_id)
+            .find_by_ident_and_kind(tcx, Ident::from_str(name), ty::AssocKind::Type, trait_id)
             .and_then(|assoc| {
                 let proj = Ty::new_projection(tcx, assoc.def_id, [self_ty]);
                 tcx.try_normalize_erasing_regions(self.typing_env(), proj).ok()

compiler/rustc_lint/src/nonstandard_style.rs

@@ -423,11 +423,11 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'_>, item: &hir::TraitItem<'_>) {
-        if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(pnames)) = item.kind {
+        if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(param_idents)) = item.kind {
             self.check_snake_case(cx, "trait method", &item.ident);
-            for param_name in pnames {
+            for param_ident in param_idents {
-                if let Some(param_name) = param_name {
+                if let Some(param_ident) = param_ident {
-                    self.check_snake_case(cx, "variable", param_name);
+                    self.check_snake_case(cx, "variable", param_ident);
                 }
             }
         }

compiler/rustc_macros/src/symbols.rs

@@ -142,13 +142,13 @@ pub(super) fn symbols(input: TokenStream) -> TokenStream {
     output
 }
 
-struct Preinterned {
+struct Predefined {
     idx: u32,
     span_of_name: Span,
 }
 
 struct Entries {
-    map: HashMap<String, Preinterned>,
+    map: HashMap<String, Predefined>,
 }
 
 impl Entries {
@@ -163,7 +163,7 @@ impl Entries {
             prev.idx
         } else {
             let idx = self.len();
-            self.map.insert(s.to_string(), Preinterned { idx, span_of_name: span });
+            self.map.insert(s.to_string(), Predefined { idx, span_of_name: span });
             idx
         }
     }
@@ -295,10 +295,14 @@ fn symbols_with_errors(input: TokenStream) -> (TokenStream, Vec<syn::Error>) {
     }
 
     let symbol_digits_base = entries.map["0"].idx;
-    let preinterned_symbols_count = entries.len();
+    let predefined_symbols_count = entries.len();
     let output = quote! {
         const SYMBOL_DIGITS_BASE: u32 = #symbol_digits_base;
-        const PREINTERNED_SYMBOLS_COUNT: u32 = #preinterned_symbols_count;
+
+        /// The number of predefined symbols; this is the the first index for
+        /// extra pre-interned symbols in an Interner created via
+        /// [`Interner::with_extra_symbols`].
+        pub const PREDEFINED_SYMBOLS_COUNT: u32 = #predefined_symbols_count;
 
         #[doc(hidden)]
         #[allow(non_upper_case_globals)]
@@ -315,10 +319,13 @@ fn symbols_with_errors(input: TokenStream) -> (TokenStream, Vec<syn::Error>) {
         }
 
         impl Interner {
-            pub(crate) fn fresh() -> Self {
+            /// Creates an `Interner` with the predefined symbols from the `symbols!` macro and
-                Interner::prefill(&[
+            /// any extra symbols provided by external drivers such as Clippy
-                    #prefill_stream
+            pub(crate) fn with_extra_symbols(extra_symbols: &[&'static str]) -> Self {
-                ])
+                Interner::prefill(
+                    &[#prefill_stream],
+                    extra_symbols,
+                )
             }
         }
     };

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -562,9 +562,9 @@ impl<'a, 'tcx> SpanDecoder for DecodeContext<'a, 'tcx> {
                     Symbol::intern(s)
                 })
             }
-            SYMBOL_PREINTERNED => {
+            SYMBOL_PREDEFINED => {
                 let symbol_index = self.read_u32();
-                Symbol::new_from_decoded(symbol_index)
+                Symbol::new(symbol_index)
             }
             _ => unreachable!(),
         }
@@ -1313,7 +1313,7 @@ impl<'a> CrateMetadataRef<'a> {
     fn get_fn_has_self_parameter(self, id: DefIndex, sess: &'a Session) -> bool {
         self.root
             .tables
-            .fn_arg_names
+            .fn_arg_idents
             .get(self, id)
             .expect("argument names not encoded for a function")
             .decode((self, sess))

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -286,7 +286,7 @@ provide! { tcx, def_id, other, cdata,
     rendered_const => { table }
     rendered_precise_capturing_args => { table }
     asyncness => { table_direct }
-    fn_arg_names => { table }
+    fn_arg_idents => { table }
     coroutine_kind => { table_direct }
     coroutine_for_closure => { table }
     coroutine_by_move_body_def_id => { table }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -201,9 +201,9 @@ impl<'a, 'tcx> SpanEncoder for EncodeContext<'a, 'tcx> {
     }
 
     fn encode_symbol(&mut self, symbol: Symbol) {
-        // if symbol preinterned, emit tag and symbol index
+        // if symbol predefined, emit tag and symbol index
-        if symbol.is_preinterned() {
+        if symbol.is_predefined() {
-            self.opaque.emit_u8(SYMBOL_PREINTERNED);
+            self.opaque.emit_u8(SYMBOL_PREDEFINED);
             self.opaque.emit_u32(symbol.as_u32());
         } else {
             // otherwise write it as string or as offset to it
@@ -1469,7 +1469,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             if let DefKind::Fn | DefKind::AssocFn = def_kind {
                 self.tables.asyncness.set_some(def_id.index, tcx.asyncness(def_id));
-                record_array!(self.tables.fn_arg_names[def_id] <- tcx.fn_arg_names(def_id));
+                record_array!(self.tables.fn_arg_idents[def_id] <- tcx.fn_arg_idents(def_id));
             }
             if let Some(name) = tcx.intrinsic(def_id) {
                 record!(self.tables.intrinsic[def_id] <- name);
@@ -2199,7 +2199,7 @@ fn prefetch_mir(tcx: TyCtxt<'_>) {
     }
 
     let reachable_set = tcx.reachable_set(());
-    par_for_each_in(tcx.mir_keys(()), |&def_id| {
+    par_for_each_in(tcx.mir_keys(()), |&&def_id| {
         let (encode_const, encode_opt) = should_encode_mir(tcx, reachable_set, def_id);
 
         if encode_const {

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -451,7 +451,7 @@ define_tables! {
     rendered_const: Table<DefIndex, LazyValue<String>>,
     rendered_precise_capturing_args: Table<DefIndex, LazyArray<PreciseCapturingArgKind<Symbol, Symbol>>>,
     asyncness: Table<DefIndex, ty::Asyncness>,
-    fn_arg_names: Table<DefIndex, LazyArray<Option<Ident>>>,
+    fn_arg_idents: Table<DefIndex, LazyArray<Option<Ident>>>,
     coroutine_kind: Table<DefIndex, hir::CoroutineKind>,
     coroutine_for_closure: Table<DefIndex, RawDefId>,
     adt_destructor: Table<DefIndex, LazyValue<ty::Destructor>>,
@@ -586,7 +586,7 @@ impl SpanTag {
 // Tags for encoding Symbol's
 const SYMBOL_STR: u8 = 0;
 const SYMBOL_OFFSET: u8 = 1;
-const SYMBOL_PREINTERNED: u8 = 2;
+const SYMBOL_PREDEFINED: u8 = 2;
 
 pub fn provide(providers: &mut Providers) {
     encoder::provide(providers);

compiler/rustc_middle/src/hir/map.rs

@@ -281,7 +281,7 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn hir_body_param_names(self, id: BodyId) -> impl Iterator<Item = Option<Ident>> {
+    pub fn hir_body_param_idents(self, id: BodyId) -> impl Iterator<Item = Option<Ident>> {
         self.hir_body(id).params.iter().map(|param| match param.pat.kind {
             PatKind::Binding(_, _, ident, _) => Some(ident),
             PatKind::Wild => Some(Ident::new(kw::Underscore, param.pat.span)),
@@ -343,7 +343,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     #[inline]
     pub fn par_hir_body_owners(self, f: impl Fn(LocalDefId) + DynSend + DynSync) {
-        par_for_each_in(&self.hir_crate_items(()).body_owners[..], |&def_id| f(def_id));
+        par_for_each_in(&self.hir_crate_items(()).body_owners[..], |&&def_id| f(def_id));
     }
 
     pub fn hir_ty_param_owner(self, def_id: LocalDefId) -> LocalDefId {

compiler/rustc_middle/src/hir/mod.rs

@@ -83,35 +83,35 @@ impl ModuleItems {
         &self,
         f: impl Fn(ItemId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
     ) -> Result<(), ErrorGuaranteed> {
-        try_par_for_each_in(&self.free_items[..], |&id| f(id))
+        try_par_for_each_in(&self.free_items[..], |&&id| f(id))
     }
 
     pub fn par_trait_items(
         &self,
         f: impl Fn(TraitItemId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
     ) -> Result<(), ErrorGuaranteed> {
-        try_par_for_each_in(&self.trait_items[..], |&id| f(id))
+        try_par_for_each_in(&self.trait_items[..], |&&id| f(id))
     }
 
     pub fn par_impl_items(
         &self,
         f: impl Fn(ImplItemId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
     ) -> Result<(), ErrorGuaranteed> {
-        try_par_for_each_in(&self.impl_items[..], |&id| f(id))
+        try_par_for_each_in(&self.impl_items[..], |&&id| f(id))
     }
 
     pub fn par_foreign_items(
         &self,
         f: impl Fn(ForeignItemId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
     ) -> Result<(), ErrorGuaranteed> {
-        try_par_for_each_in(&self.foreign_items[..], |&id| f(id))
+        try_par_for_each_in(&self.foreign_items[..], |&&id| f(id))
     }
 
     pub fn par_opaques(
         &self,
         f: impl Fn(LocalDefId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
     ) -> Result<(), ErrorGuaranteed> {
-        try_par_for_each_in(&self.opaques[..], |&id| f(id))
+        try_par_for_each_in(&self.opaques[..], |&&id| f(id))
     }
 }
 
@@ -215,9 +215,9 @@ pub fn provide(providers: &mut Providers) {
         let hir_id = tcx.local_def_id_to_hir_id(def_id);
         tcx.hir_opt_ident_span(hir_id)
     };
-    providers.fn_arg_names = |tcx, def_id| {
+    providers.fn_arg_idents = |tcx, def_id| {
         if let Some(body_id) = tcx.hir_node_by_def_id(def_id).body_id() {
-            tcx.arena.alloc_from_iter(tcx.hir_body_param_names(body_id))
+            tcx.arena.alloc_from_iter(tcx.hir_body_param_idents(body_id))
         } else if let Node::TraitItem(&TraitItem {
             kind: TraitItemKind::Fn(_, TraitFn::Required(idents)),
             ..
@@ -231,7 +231,7 @@ pub fn provide(providers: &mut Providers) {
         } else {
             span_bug!(
                 tcx.hir_span(tcx.local_def_id_to_hir_id(def_id)),
-                "fn_arg_names: unexpected item {:?}",
+                "fn_arg_idents: unexpected item {:?}",
                 def_id
             );
         }

compiler/rustc_middle/src/query/mod.rs

@@ -1442,8 +1442,8 @@ rustc_queries! {
         desc { |tcx| "computing target features for inline asm of `{}`", tcx.def_path_str(def_id) }
     }
 
-    query fn_arg_names(def_id: DefId) -> &'tcx [Option<rustc_span::Ident>] {
+    query fn_arg_idents(def_id: DefId) -> &'tcx [Option<rustc_span::Ident>] {
-        desc { |tcx| "looking up function parameter names for `{}`", tcx.def_path_str(def_id) }
+        desc { |tcx| "looking up function parameter identifiers for `{}`", tcx.def_path_str(def_id) }
         separate_provide_extern
     }
 
@@ -1900,6 +1900,11 @@ rustc_queries! {
 
     // The macro which defines `rustc_metadata::provide_extern` depends on this query's name.
     // Changing the name should cause a compiler error, but in case that changes, be aware.
+    //
+    // The hash should not be calculated before the `analysis` pass is complete, specifically
+    // until `tcx.untracked().definitions.freeze()` has been called, otherwise if incremental
+    // compilation is enabled calculating this hash can freeze this structure too early in
+    // compilation and cause subsequent crashes when attempting to write to `definitions`
     query crate_hash(_: CrateNum) -> Svh {
         eval_always
         desc { "looking up the hash a crate" }

compiler/rustc_middle/src/query/on_disk_cache.rs

@@ -46,7 +46,7 @@ const TAG_EXPN_DATA: u8 = 1;
 // Tags for encoding Symbol's
 const SYMBOL_STR: u8 = 0;
 const SYMBOL_OFFSET: u8 = 1;
-const SYMBOL_PREINTERNED: u8 = 2;
+const SYMBOL_PREDEFINED: u8 = 2;
 
 /// Provides an interface to incremental compilation data cached from the
 /// previous compilation session. This data will eventually include the results
@@ -674,9 +674,9 @@ impl<'a, 'tcx> SpanDecoder for CacheDecoder<'a, 'tcx> {
                     Symbol::intern(s)
                 })
             }
-            SYMBOL_PREINTERNED => {
+            SYMBOL_PREDEFINED => {
                 let symbol_index = self.read_u32();
-                Symbol::new_from_decoded(symbol_index)
+                Symbol::new(symbol_index)
             }
             _ => unreachable!(),
         }
@@ -892,9 +892,9 @@ impl<'a, 'tcx> SpanEncoder for CacheEncoder<'a, 'tcx> {
 
     // copy&paste impl from rustc_metadata
     fn encode_symbol(&mut self, symbol: Symbol) {
-        // if symbol preinterned, emit tag and symbol index
+        // if symbol predefined, emit tag and symbol index
-        if symbol.is_preinterned() {
+        if symbol.is_predefined() {
-            self.encoder.emit_u8(SYMBOL_PREINTERNED);
+            self.encoder.emit_u8(SYMBOL_PREDEFINED);
             self.encoder.emit_u32(symbol.as_u32());
         } else {
             // otherwise write it as string or as offset to it

compiler/rustc_middle/src/ty/assoc.rs

@@ -98,10 +98,10 @@ impl AssocItem {
 
     pub fn descr(&self) -> &'static str {
         match self.kind {
-            ty::AssocKind::Const => "const",
+            ty::AssocKind::Const => "associated const",
             ty::AssocKind::Fn if self.fn_has_self_parameter => "method",
             ty::AssocKind::Fn => "associated function",
-            ty::AssocKind::Type => "type",
+            ty::AssocKind::Type => "associated type",
         }
     }
 
@@ -155,6 +155,8 @@ impl AssocKind {
 impl std::fmt::Display for AssocKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            // FIXME: fails to distinguish between "associated function" and
+            // "method" because `has_self` isn't known here.
             AssocKind::Fn => write!(f, "method"),
             AssocKind::Const => write!(f, "associated const"),
             AssocKind::Type => write!(f, "associated type"),
@@ -199,8 +201,9 @@ impl AssocItems {
         self.items.get_by_key(name)
     }
 
-    /// Returns the associated item with the given name and `AssocKind`, if one exists.
+    /// Returns the associated item with the given identifier and `AssocKind`, if one exists.
-    pub fn find_by_name_and_kind(
+    /// The identifier is matched hygienically.
+    pub fn find_by_ident_and_kind(
         &self,
         tcx: TyCtxt<'_>,
         ident: Ident,
@@ -212,8 +215,9 @@ impl AssocItems {
             .find(|item| tcx.hygienic_eq(ident, item.ident(tcx), parent_def_id))
     }
 
-    /// Returns the associated item with the given name and any of `AssocKind`, if one exists.
+    /// Returns the associated item with the given identifier and any of `AssocKind`, if one
-    pub fn find_by_name_and_kinds(
+    /// exists. The identifier is matched hygienically.
+    pub fn find_by_ident_and_kinds(
         &self,
         tcx: TyCtxt<'_>,
         ident: Ident,
@@ -221,11 +225,12 @@ impl AssocItems {
         kinds: &[AssocKind],
         parent_def_id: DefId,
     ) -> Option<&ty::AssocItem> {
-        kinds.iter().find_map(|kind| self.find_by_name_and_kind(tcx, ident, *kind, parent_def_id))
+        kinds.iter().find_map(|kind| self.find_by_ident_and_kind(tcx, ident, *kind, parent_def_id))
     }
 
-    /// Returns the associated item with the given name in the given `Namespace`, if one exists.
+    /// Returns the associated item with the given identifier in the given `Namespace`, if one
-    pub fn find_by_name_and_namespace(
+    /// exists. The identifier is matched hygienically.
+    pub fn find_by_ident_and_namespace(
         &self,
         tcx: TyCtxt<'_>,
         ident: Ident,

compiler/rustc_middle/src/ty/error.rs

@@ -279,7 +279,7 @@ impl<'tcx> TyCtxt<'tcx> {
         p.hash(&mut s);
         let hash = s.finish();
         *path = Some(path.take().unwrap_or_else(|| {
-            self.output_filenames(()).temp_path_ext(&format!("long-type-{hash}.txt"), None)
+            self.output_filenames(()).temp_path_for_diagnostic(&format!("long-type-{hash}.txt"))
         }));
         let Ok(mut file) =
             File::options().create(true).read(true).append(true).open(&path.as_ref().unwrap())

compiler/rustc_middle/src/ty/mod.rs

@@ -1939,15 +1939,15 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
     /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
     /// definition's parent/scope to perform comparison.
-    pub fn hygienic_eq(self, use_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool {
+    pub fn hygienic_eq(self, use_ident: Ident, def_ident: Ident, def_parent_def_id: DefId) -> bool {
-        // We could use `Ident::eq` here, but we deliberately don't. The name
+        // We could use `Ident::eq` here, but we deliberately don't. The identifier
         // comparison fails frequently, and we want to avoid the expensive
         // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
-        use_name.name == def_name.name
+        use_ident.name == def_ident.name
-            && use_name
+            && use_ident
                 .span
                 .ctxt()
-                .hygienic_eq(def_name.span.ctxt(), self.expn_that_defined(def_parent_def_id))
+                .hygienic_eq(def_ident.span.ctxt(), self.expn_that_defined(def_parent_def_id))
     }
 
     pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident {

compiler/rustc_middle/src/ty/print/mod.rs

@@ -382,7 +382,7 @@ pub fn shrunk_instance_name<'tcx>(
             return (s, None);
         }
 
-        let path = tcx.output_filenames(()).temp_path_ext("long-type.txt", None);
+        let path = tcx.output_filenames(()).temp_path_for_diagnostic("long-type.txt");
         let written_to_path = std::fs::write(&path, s).ok().map(|_| path);
 
         (shrunk, written_to_path)

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -620,7 +620,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             // the children of the visible parent (as was done when computing
             // `visible_parent_map`), looking for the specific child we currently have and then
             // have access to the re-exported name.
-            DefPathData::TypeNs(Some(ref mut name)) if Some(visible_parent) != actual_parent => {
+            DefPathData::TypeNs(ref mut name) if Some(visible_parent) != actual_parent => {
                 // Item might be re-exported several times, but filter for the one
                 // that's public and whose identifier isn't `_`.
                 let reexport = self
@@ -641,7 +641,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             }
             // Re-exported `extern crate` (#43189).
             DefPathData::CrateRoot => {
-                data = DefPathData::TypeNs(Some(self.tcx().crate_name(def_id.krate)));
+                data = DefPathData::TypeNs(self.tcx().crate_name(def_id.krate));
             }
             _ => {}
         }

compiler/rustc_middle/src/ty/significant_drop_order.rs

@@ -26,7 +26,7 @@ fn true_significant_drop_ty<'tcx>(
                     name_rev.push(tcx.crate_name(did.krate));
                 }
                 rustc_hir::definitions::DefPathData::TypeNs(symbol) => {
-                    name_rev.push(symbol.unwrap());
+                    name_rev.push(symbol);
                 }
                 _ => return None,
             }

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -39,26 +39,26 @@ impl<'tcx> crate::MirPass<'tcx> for InstSimplify {
             attr::contains_name(tcx.hir_krate_attrs(), sym::rustc_preserve_ub_checks);
         for block in body.basic_blocks.as_mut() {
             for statement in block.statements.iter_mut() {
-                match statement.kind {
+                let StatementKind::Assign(box (.., rvalue)) = &mut statement.kind else {
-                    StatementKind::Assign(box (_place, ref mut rvalue)) => {
+                    continue;
-                        if !preserve_ub_checks {
+                };
-                            ctx.simplify_ub_check(rvalue);
+
-                        }
+                if !preserve_ub_checks {
-                        ctx.simplify_bool_cmp(rvalue);
+                    ctx.simplify_ub_check(rvalue);
-                        ctx.simplify_ref_deref(rvalue);
-                        ctx.simplify_ptr_aggregate(rvalue);
-                        ctx.simplify_cast(rvalue);
-                        ctx.simplify_repeated_aggregate(rvalue);
-                        ctx.simplify_repeat_once(rvalue);
-                    }
-                    _ => {}
                 }
+                ctx.simplify_bool_cmp(rvalue);
+                ctx.simplify_ref_deref(rvalue);
+                ctx.simplify_ptr_aggregate(rvalue);
+                ctx.simplify_cast(rvalue);
+                ctx.simplify_repeated_aggregate(rvalue);
+                ctx.simplify_repeat_once(rvalue);
             }
 
-            ctx.simplify_primitive_clone(block.terminator.as_mut().unwrap(), &mut block.statements);
+            let terminator = block.terminator.as_mut().unwrap();
-            ctx.simplify_intrinsic_assert(block.terminator.as_mut().unwrap());
+            ctx.simplify_primitive_clone(terminator, &mut block.statements);
-            ctx.simplify_nounwind_call(block.terminator.as_mut().unwrap());
+            ctx.simplify_intrinsic_assert(terminator);
-            simplify_duplicate_switch_targets(block.terminator.as_mut().unwrap());
+            ctx.simplify_nounwind_call(terminator);
+            simplify_duplicate_switch_targets(terminator);
         }
     }
 
@@ -105,43 +105,34 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
 
     /// Transform boolean comparisons into logical operations.
     fn simplify_bool_cmp(&self, rvalue: &mut Rvalue<'tcx>) {
-        match rvalue {
+        let Rvalue::BinaryOp(op @ (BinOp::Eq | BinOp::Ne), box (a, b)) = &*rvalue else { return };
-            Rvalue::BinaryOp(op @ (BinOp::Eq | BinOp::Ne), box (a, b)) => {
+        *rvalue = match (op, self.try_eval_bool(a), self.try_eval_bool(b)) {
-                let new = match (op, self.try_eval_bool(a), self.try_eval_bool(b)) {
+            // Transform "Eq(a, true)" ==> "a"
-                    // Transform "Eq(a, true)" ==> "a"
+            (BinOp::Eq, _, Some(true)) => Rvalue::Use(a.clone()),
-                    (BinOp::Eq, _, Some(true)) => Some(Rvalue::Use(a.clone())),
 
-                    // Transform "Ne(a, false)" ==> "a"
+            // Transform "Ne(a, false)" ==> "a"
-                    (BinOp::Ne, _, Some(false)) => Some(Rvalue::Use(a.clone())),
+            (BinOp::Ne, _, Some(false)) => Rvalue::Use(a.clone()),
 
-                    // Transform "Eq(true, b)" ==> "b"
+            // Transform "Eq(true, b)" ==> "b"
-                    (BinOp::Eq, Some(true), _) => Some(Rvalue::Use(b.clone())),
+            (BinOp::Eq, Some(true), _) => Rvalue::Use(b.clone()),
 
-                    // Transform "Ne(false, b)" ==> "b"
+            // Transform "Ne(false, b)" ==> "b"
-                    (BinOp::Ne, Some(false), _) => Some(Rvalue::Use(b.clone())),
+            (BinOp::Ne, Some(false), _) => Rvalue::Use(b.clone()),
 
-                    // Transform "Eq(false, b)" ==> "Not(b)"
+            // Transform "Eq(false, b)" ==> "Not(b)"
-                    (BinOp::Eq, Some(false), _) => Some(Rvalue::UnaryOp(UnOp::Not, b.clone())),
+            (BinOp::Eq, Some(false), _) => Rvalue::UnaryOp(UnOp::Not, b.clone()),
 
-                    // Transform "Ne(true, b)" ==> "Not(b)"
+            // Transform "Ne(true, b)" ==> "Not(b)"
-                    (BinOp::Ne, Some(true), _) => Some(Rvalue::UnaryOp(UnOp::Not, b.clone())),
+            (BinOp::Ne, Some(true), _) => Rvalue::UnaryOp(UnOp::Not, b.clone()),
 
-                    // Transform "Eq(a, false)" ==> "Not(a)"
+            // Transform "Eq(a, false)" ==> "Not(a)"
-                    (BinOp::Eq, _, Some(false)) => Some(Rvalue::UnaryOp(UnOp::Not, a.clone())),
+            (BinOp::Eq, _, Some(false)) => Rvalue::UnaryOp(UnOp::Not, a.clone()),
 
-                    // Transform "Ne(a, true)" ==> "Not(a)"
+            // Transform "Ne(a, true)" ==> "Not(a)"
-                    (BinOp::Ne, _, Some(true)) => Some(Rvalue::UnaryOp(UnOp::Not, a.clone())),
+            (BinOp::Ne, _, Some(true)) => Rvalue::UnaryOp(UnOp::Not, a.clone()),
 
-                    _ => None,
+            _ => return,
-                };
+        };
-
-                if let Some(new) = new {
-                    *rvalue = new;
-                }
-            }
-
-            _ => {}
-        }
     }
 
     fn try_eval_bool(&self, a: &Operand<'_>) -> Option<bool> {
@@ -151,64 +142,58 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
 
     /// Transform `&(*a)` ==> `a`.
     fn simplify_ref_deref(&self, rvalue: &mut Rvalue<'tcx>) {
-        if let Rvalue::Ref(_, _, place) | Rvalue::RawPtr(_, place) = rvalue {
+        if let Rvalue::Ref(_, _, place) | Rvalue::RawPtr(_, place) = rvalue
-            if let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection() {
+            && let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection()
-                if rvalue.ty(self.local_decls, self.tcx) != base.ty(self.local_decls, self.tcx).ty {
+            && rvalue.ty(self.local_decls, self.tcx) == base.ty(self.local_decls, self.tcx).ty
-                    return;
+        {
-                }
+            *rvalue = Rvalue::Use(Operand::Copy(Place {
-
+                local: base.local,
-                *rvalue = Rvalue::Use(Operand::Copy(Place {
+                projection: self.tcx.mk_place_elems(base.projection),
-                    local: base.local,
+            }));
-                    projection: self.tcx.mk_place_elems(base.projection),
-                }));
-            }
         }
     }
 
     /// Transform `Aggregate(RawPtr, [p, ()])` ==> `Cast(PtrToPtr, p)`.
     fn simplify_ptr_aggregate(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Aggregate(box AggregateKind::RawPtr(pointee_ty, mutability), fields) = rvalue
+            && let meta_ty = fields.raw[1].ty(self.local_decls, self.tcx)
+            && meta_ty.is_unit()
         {
-            let meta_ty = fields.raw[1].ty(self.local_decls, self.tcx);
+            // The mutable borrows we're holding prevent printing `rvalue` here
-            if meta_ty.is_unit() {
+            let mut fields = std::mem::take(fields);
-                // The mutable borrows we're holding prevent printing `rvalue` here
+            let _meta = fields.pop().unwrap();
-                let mut fields = std::mem::take(fields);
+            let data = fields.pop().unwrap();
-                let _meta = fields.pop().unwrap();
+            let ptr_ty = Ty::new_ptr(self.tcx, *pointee_ty, *mutability);
-                let data = fields.pop().unwrap();
+            *rvalue = Rvalue::Cast(CastKind::PtrToPtr, data, ptr_ty);
-                let ptr_ty = Ty::new_ptr(self.tcx, *pointee_ty, *mutability);
-                *rvalue = Rvalue::Cast(CastKind::PtrToPtr, data, ptr_ty);
-            }
         }
     }
 
     fn simplify_ub_check(&self, rvalue: &mut Rvalue<'tcx>) {
-        if let Rvalue::NullaryOp(NullOp::UbChecks, _) = *rvalue {
+        let Rvalue::NullaryOp(NullOp::UbChecks, _) = *rvalue else { return };
-            let const_ = Const::from_bool(self.tcx, self.tcx.sess.ub_checks());
+
-            let constant = ConstOperand { span: DUMMY_SP, const_, user_ty: None };
+        let const_ = Const::from_bool(self.tcx, self.tcx.sess.ub_checks());
-            *rvalue = Rvalue::Use(Operand::Constant(Box::new(constant)));
+        let constant = ConstOperand { span: DUMMY_SP, const_, user_ty: None };
-        }
+        *rvalue = Rvalue::Use(Operand::Constant(Box::new(constant)));
     }
 
     fn simplify_cast(&self, rvalue: &mut Rvalue<'tcx>) {
-        if let Rvalue::Cast(kind, operand, cast_ty) = rvalue {
+        let Rvalue::Cast(kind, operand, cast_ty) = rvalue else { return };
-            let operand_ty = operand.ty(self.local_decls, self.tcx);
+
-            if operand_ty == *cast_ty {
+        let operand_ty = operand.ty(self.local_decls, self.tcx);
-                *rvalue = Rvalue::Use(operand.clone());
+        if operand_ty == *cast_ty {
-            } else if *kind == CastKind::Transmute {
+            *rvalue = Rvalue::Use(operand.clone());
-                // Transmuting an integer to another integer is just a signedness cast
+        } else if *kind == CastKind::Transmute
-                if let (ty::Int(int), ty::Uint(uint)) | (ty::Uint(uint), ty::Int(int)) =
+            // Transmuting an integer to another integer is just a signedness cast
-                    (operand_ty.kind(), cast_ty.kind())
+            && let (ty::Int(int), ty::Uint(uint)) | (ty::Uint(uint), ty::Int(int)) =
-                    && int.bit_width() == uint.bit_width()
+                (operand_ty.kind(), cast_ty.kind())
-                {
+            && int.bit_width() == uint.bit_width()
-                    // The width check isn't strictly necessary, as different widths
+        {
-                    // are UB and thus we'd be allowed to turn it into a cast anyway.
+            // The width check isn't strictly necessary, as different widths
-                    // But let's keep the UB around for codegen to exploit later.
+            // are UB and thus we'd be allowed to turn it into a cast anyway.
-                    // (If `CastKind::Transmute` ever becomes *not* UB for mismatched sizes,
+            // But let's keep the UB around for codegen to exploit later.
-                    // then the width check is necessary for big-endian correctness.)
+            // (If `CastKind::Transmute` ever becomes *not* UB for mismatched sizes,
-                    *kind = CastKind::IntToInt;
+            // then the width check is necessary for big-endian correctness.)
-                    return;
+            *kind = CastKind::IntToInt;
-                }
-            }
         }
     }
 
@@ -277,7 +262,7 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
     }
 
     fn simplify_nounwind_call(&self, terminator: &mut Terminator<'tcx>) {
-        let TerminatorKind::Call { func, unwind, .. } = &mut terminator.kind else {
+        let TerminatorKind::Call { ref func, ref mut unwind, .. } = terminator.kind else {
             return;
         };
 
@@ -290,7 +275,7 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
             ty::FnDef(..) => body_ty.fn_sig(self.tcx).abi(),
             ty::Closure(..) => ExternAbi::RustCall,
             ty::Coroutine(..) => ExternAbi::Rust,
-            _ => bug!("unexpected body ty: {:?}", body_ty),
+            _ => bug!("unexpected body ty: {body_ty:?}"),
         };
 
         if !layout::fn_can_unwind(self.tcx, Some(def_id), body_abi) {
@@ -299,10 +284,9 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
     }
 
     fn simplify_intrinsic_assert(&self, terminator: &mut Terminator<'tcx>) {
-        let TerminatorKind::Call { func, target, .. } = &mut terminator.kind else {
+        let TerminatorKind::Call { ref func, target: ref mut target @ Some(target_block), .. } =
-            return;
+            terminator.kind
-        };
+        else {
-        let Some(target_block) = target else {
             return;
         };
         let func_ty = func.ty(self.local_decls, self.tcx);
@@ -310,12 +294,10 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
             return;
         };
         // The intrinsics we are interested in have one generic parameter
-        if args.is_empty() {
+        let [arg, ..] = args[..] else { return };
-            return;
-        }
 
         let known_is_valid =
-            intrinsic_assert_panics(self.tcx, self.typing_env, args[0], intrinsic_name);
+            intrinsic_assert_panics(self.tcx, self.typing_env, arg, intrinsic_name);
         match known_is_valid {
             // We don't know the layout or it's not validity assertion at all, don't touch it
             None => {}
@@ -325,7 +307,7 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
             }
             Some(false) => {
                 // If we know the assert does not panic, turn the call into a Goto
-                terminator.kind = TerminatorKind::Goto { target: *target_block };
+                terminator.kind = TerminatorKind::Goto { target: target_block };
             }
         }
     }
@@ -346,9 +328,7 @@ fn resolve_rust_intrinsic<'tcx>(
     tcx: TyCtxt<'tcx>,
     func_ty: Ty<'tcx>,
 ) -> Option<(Symbol, GenericArgsRef<'tcx>)> {
-    if let ty::FnDef(def_id, args) = *func_ty.kind() {
+    let ty::FnDef(def_id, args) = *func_ty.kind() else { return None };
-        let intrinsic = tcx.intrinsic(def_id)?;
+    let intrinsic = tcx.intrinsic(def_id)?;
-        return Some((intrinsic.name, args));
+    Some((intrinsic.name, args))
-    }
-    None
 }

compiler/rustc_monomorphize/src/collector.rs

@@ -1689,7 +1689,7 @@ pub(crate) fn collect_crate_mono_items<'tcx>(
             let mut recursion_depths = DefIdMap::default();
             collect_items_rec(
                 tcx,
-                dummy_spanned(root),
+                dummy_spanned(*root),
                 &state,
                 &mut recursion_depths,
                 recursion_limit,

compiler/rustc_monomorphize/src/mono_checks/move_check.rs

@@ -191,7 +191,7 @@ impl<'tcx> MoveCheckVisitor<'tcx> {
 
 fn assoc_fn_of_type<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, fn_ident: Ident) -> Option<DefId> {
     for impl_def_id in tcx.inherent_impls(def_id) {
-        if let Some(new) = tcx.associated_items(impl_def_id).find_by_name_and_kind(
+        if let Some(new) = tcx.associated_items(impl_def_id).find_by_ident_and_kind(
             tcx,
             fn_ident,
             AssocKind::Fn,

compiler/rustc_parse/src/parser/expr.rs

@@ -2166,10 +2166,15 @@ impl<'a> Parser<'a> {
                 let expr = self
                     .eat_metavar_seq(mv_kind, |this| this.parse_expr())
                     .expect("metavar seq expr");
-                let ast::ExprKind::Lit(token_lit) = expr.kind else {
+                if let ast::ExprKind::Lit(token_lit) = expr.kind {
-                    panic!("didn't reparse an expr");
+                    Some(token_lit)
-                };
+                } else if let ast::ExprKind::Unary(UnOp::Neg, inner) = &expr.kind
-                Some(token_lit)
+                    && let ast::Expr { kind: ast::ExprKind::Lit(_), .. } = **inner
+                {
+                    None
+                } else {
+                    panic!("unexpected reparsed expr: {:?}", expr.kind);
+                }
             }
             _ => None,
         }

compiler/rustc_parse/src/parser/item.rs

@@ -602,21 +602,13 @@ impl<'a> Parser<'a> {
         let polarity = self.parse_polarity();
 
         // Parse both types and traits as a type, then reinterpret if necessary.
-        let err_path = |span| ast::Path::from_ident(Ident::new(kw::Empty, span));
         let ty_first = if self.token.is_keyword(kw::For) && self.look_ahead(1, |t| t != &token::Lt)
         {
             let span = self.prev_token.span.between(self.token.span);
-            self.dcx().emit_err(errors::MissingTraitInTraitImpl {
+            return Err(self.dcx().create_err(errors::MissingTraitInTraitImpl {
                 span,
                 for_span: span.to(self.token.span),
-            });
+            }));
-
-            P(Ty {
-                kind: TyKind::Path(None, err_path(span)),
-                span,
-                id: DUMMY_NODE_ID,
-                tokens: None,
-            })
         } else {
             self.parse_ty_with_generics_recovery(&generics)?
         };
@@ -657,6 +649,7 @@ impl<'a> Parser<'a> {
                     other => {
                         if let TyKind::ImplTrait(_, bounds) = other
                             && let [bound] = bounds.as_slice()
+                            && let GenericBound::Trait(poly_trait_ref) = bound
                         {
                             // Suggest removing extra `impl` keyword:
                             // `impl<T: Default> impl Default for Wrapper<T>`
@@ -666,12 +659,12 @@ impl<'a> Parser<'a> {
                                 extra_impl_kw,
                                 impl_trait_span: ty_first.span,
                             });
+                            poly_trait_ref.trait_ref.path.clone()
                         } else {
-                            self.dcx().emit_err(errors::ExpectedTraitInTraitImplFoundType {
+                            return Err(self.dcx().create_err(
-                                span: ty_first.span,
+                                errors::ExpectedTraitInTraitImplFoundType { span: ty_first.span },
-                            });
+                            ));
                         }
-                        err_path(ty_first.span)
                     }
                 };
                 let trait_ref = TraitRef { path, ref_id: ty_first.id };

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -141,7 +141,7 @@ impl<D: Deps> DepGraph<D> {
         let colors = DepNodeColorMap::new(prev_graph_node_count);
 
         // Instantiate a node with zero dependencies only once for anonymous queries.
-        let _green_node_index = current.alloc_node(
+        let _green_node_index = current.alloc_new_node(
             DepNode { kind: D::DEP_KIND_ANON_ZERO_DEPS, hash: current.anon_id_seed.into() },
             EdgesVec::new(),
             Fingerprint::ZERO,
@@ -149,7 +149,7 @@ impl<D: Deps> DepGraph<D> {
         assert_eq!(_green_node_index, DepNodeIndex::SINGLETON_ZERO_DEPS_ANON_NODE);
 
         // Instantiate a dependy-less red node only once for anonymous queries.
-        let red_node_index = current.alloc_node(
+        let red_node_index = current.alloc_new_node(
             DepNode { kind: D::DEP_KIND_RED, hash: Fingerprint::ZERO.into() },
             EdgesVec::new(),
             Fingerprint::ZERO,
@@ -438,7 +438,7 @@ impl<D: Deps> DepGraphData<D> {
                 // memory impact of this `anon_node_to_index` map remains tolerable, and helps
                 // us avoid useless growth of the graph with almost-equivalent nodes.
                 self.current.anon_node_to_index.get_or_insert_with(target_dep_node, || {
-                    self.current.alloc_node(target_dep_node, task_deps, Fingerprint::ZERO)
+                    self.current.alloc_new_node(target_dep_node, task_deps, Fingerprint::ZERO)
                 })
             }
         };
@@ -680,8 +680,8 @@ impl<D: Deps> DepGraphData<D> {
         qcx: Qcx,
         diagnostic: &DiagInner,
     ) -> DepNodeIndex {
-        // Use `send` so we get an unique index, even though the dep node is not.
+        // Use `send_new` so we get an unique index, even though the dep node is not.
-        let dep_node_index = self.current.encoder.send(
+        let dep_node_index = self.current.encoder.send_new(
             DepNode {
                 kind: D::DEP_KIND_SIDE_EFFECT,
                 hash: PackedFingerprint::from(Fingerprint::ZERO),
@@ -713,20 +713,22 @@ impl<D: Deps> DepGraphData<D> {
                 }
             }
 
-            // Manually recreate the node as `promote_node_and_deps_to_current` expects all
+            // Use `send_and_color` as `promote_node_and_deps_to_current` expects all
-            // green dependencies.
+            // green dependencies. `send_and_color` will also prevent multiple nodes
-            let dep_node_index = self.current.encoder.send(
+            // being encoded for concurrent calls.
+            let dep_node_index = self.current.encoder.send_and_color(
+                prev_index,
+                &self.colors,
                 DepNode {
                     kind: D::DEP_KIND_SIDE_EFFECT,
                     hash: PackedFingerprint::from(Fingerprint::ZERO),
                 },
                 Fingerprint::ZERO,
                 std::iter::once(DepNodeIndex::FOREVER_RED_NODE).collect(),
+                true,
             );
+            // This will just overwrite the same value for concurrent calls.
             qcx.store_side_effect(dep_node_index, side_effect);
-
-            // Mark the node as green.
-            self.colors.insert(prev_index, DepNodeColor::Green(dep_node_index));
         })
     }
 
@@ -736,38 +738,43 @@ impl<D: Deps> DepGraphData<D> {
         edges: EdgesVec,
         fingerprint: Option<Fingerprint>,
     ) -> DepNodeIndex {
-        let dep_node_index =
-            self.current.alloc_node(key, edges, fingerprint.unwrap_or(Fingerprint::ZERO));
-
         if let Some(prev_index) = self.previous.node_to_index_opt(&key) {
             // Determine the color and index of the new `DepNode`.
-            let color = if let Some(fingerprint) = fingerprint {
+            let is_green = if let Some(fingerprint) = fingerprint {
                 if fingerprint == self.previous.fingerprint_by_index(prev_index) {
                     // This is a green node: it existed in the previous compilation,
                     // its query was re-executed, and it has the same result as before.
-                    DepNodeColor::Green(dep_node_index)
+                    true
                 } else {
                     // This is a red node: it existed in the previous compilation, its query
                     // was re-executed, but it has a different result from before.
-                    DepNodeColor::Red
+                    false
                 }
             } else {
                 // This is a red node, effectively: it existed in the previous compilation
                 // session, its query was re-executed, but it doesn't compute a result hash
                 // (i.e. it represents a `no_hash` query), so we have no way of determining
                 // whether or not the result was the same as before.
-                DepNodeColor::Red
+                false
             };
 
-            debug_assert!(
+            let fingerprint = fingerprint.unwrap_or(Fingerprint::ZERO);
-                self.colors.get(prev_index).is_none(),
+
-                "DepGraph::with_task() - Duplicate DepNodeColor insertion for {key:?}",
+            let dep_node_index = self.current.encoder.send_and_color(
+                prev_index,
+                &self.colors,
+                key,
+                fingerprint,
+                edges,
+                is_green,
             );
 
-            self.colors.insert(prev_index, color);
+            self.current.record_node(dep_node_index, key, fingerprint);
-        }
 
-        dep_node_index
+            dep_node_index
+        } else {
+            self.current.alloc_new_node(key, edges, fingerprint.unwrap_or(Fingerprint::ZERO))
+        }
     }
 
     fn promote_node_and_deps_to_current(&self, prev_index: SerializedDepNodeIndex) -> DepNodeIndex {
@@ -1246,19 +1253,15 @@ impl<D: Deps> CurrentDepGraph<D> {
         assert_eq!(previous, fingerprint, "Unstable fingerprints for {:?}", key);
     }
 
-    /// Writes the node to the current dep-graph and allocates a `DepNodeIndex` for it.
-    /// Assumes that this is a node that has no equivalent in the previous dep-graph.
     #[inline(always)]
-    fn alloc_node(
+    fn record_node(
         &self,
+        dep_node_index: DepNodeIndex,
         key: DepNode,
-        edges: EdgesVec,
+        _current_fingerprint: Fingerprint,
-        current_fingerprint: Fingerprint,
+    ) {
-    ) -> DepNodeIndex {
-        let dep_node_index = self.encoder.send(key, current_fingerprint, edges);
-
         #[cfg(debug_assertions)]
-        self.record_edge(dep_node_index, key, current_fingerprint);
+        self.record_edge(dep_node_index, key, _current_fingerprint);
 
         if let Some(ref nodes_in_current_session) = self.nodes_in_current_session {
             outline(|| {
@@ -1267,6 +1270,20 @@ impl<D: Deps> CurrentDepGraph<D> {
                 }
             });
         }
+    }
+
+    /// Writes the node to the current dep-graph and allocates a `DepNodeIndex` for it.
+    /// Assumes that this is a node that has no equivalent in the previous dep-graph.
+    #[inline(always)]
+    fn alloc_new_node(
+        &self,
+        key: DepNode,
+        edges: EdgesVec,
+        current_fingerprint: Fingerprint,
+    ) -> DepNodeIndex {
+        let dep_node_index = self.encoder.send_new(key, current_fingerprint, edges);
+
+        self.record_node(dep_node_index, key, current_fingerprint);
 
         dep_node_index
     }

compiler/rustc_query_system/src/dep_graph/serialized.rs

@@ -707,7 +707,8 @@ impl<D: Deps> GraphEncoder<D> {
         }
     }
 
-    pub(crate) fn send(
+    /// Encodes a node that does not exists in the previous graph.
+    pub(crate) fn send_new(
         &self,
         node: DepNode,
         fingerprint: Fingerprint,
@@ -718,6 +719,40 @@ impl<D: Deps> GraphEncoder<D> {
         self.status.lock().as_mut().unwrap().encode_node(&node, &self.record_graph)
     }
 
+    /// Encodes a node that exists in the previous graph, but was re-executed.
+    ///
+    /// This will also ensure the dep node is colored either red or green.
+    pub(crate) fn send_and_color(
+        &self,
+        prev_index: SerializedDepNodeIndex,
+        colors: &DepNodeColorMap,
+        node: DepNode,
+        fingerprint: Fingerprint,
+        edges: EdgesVec,
+        is_green: bool,
+    ) -> DepNodeIndex {
+        let _prof_timer = self.profiler.generic_activity("incr_comp_encode_dep_graph");
+        let node = NodeInfo { node, fingerprint, edges };
+
+        let mut status = self.status.lock();
+        let status = status.as_mut().unwrap();
+
+        // Check colors inside the lock to avoid racing when `send_promoted` is called concurrently
+        // on the same index.
+        match colors.get(prev_index) {
+            None => {
+                let dep_node_index = status.encode_node(&node, &self.record_graph);
+                colors.insert(
+                    prev_index,
+                    if is_green { DepNodeColor::Green(dep_node_index) } else { DepNodeColor::Red },
+                );
+                dep_node_index
+            }
+            Some(DepNodeColor::Green(dep_node_index)) => dep_node_index,
+            Some(DepNodeColor::Red) => panic!(),
+        }
+    }
+
     /// Encodes a node that was promoted from the previous graph. It reads the information directly from
     /// the previous dep graph and expects all edges to already have a new dep node index assigned.
     ///
@@ -733,8 +768,8 @@ impl<D: Deps> GraphEncoder<D> {
         let mut status = self.status.lock();
         let status = status.as_mut().unwrap();
 
-        // Check colors inside the lock to avoid racing when `send_promoted` is called concurrently
+        // Check colors inside the lock to avoid racing when `send_promoted` or `send_and_color`
-        // on the same index.
+        // is called concurrently on the same index.
         match colors.get(prev_index) {
             None => {
                 let dep_node_index =

compiler/rustc_resolve/Cargo.toml

@@ -18,7 +18,6 @@ rustc_expand = { path = "../rustc_expand" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_hir = { path = "../rustc_hir" }
-rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_metadata = { path = "../rustc_metadata" }
 rustc_middle = { path = "../rustc_middle" }

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -1207,7 +1207,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             for (rule_i, rule_span) in &self.r.macro_map[&def_id.to_def_id()].rule_spans {
                 self.r
                     .unused_macro_rules
-                    .entry(def_id)
+                    .entry(node_id)
                     .or_default()
                     .insert(*rule_i, (ident, *rule_span));
             }

compiler/rustc_resolve/src/diagnostics.rs

@@ -170,10 +170,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
     fn report_with_use_injections(&mut self, krate: &Crate) {
         for UseError { mut err, candidates, def_id, instead, suggestion, path, is_call } in
-            self.use_injections.drain(..)
+            std::mem::take(&mut self.use_injections)
         {
             let (span, found_use) = if let Some(def_id) = def_id.as_local() {
-                UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id])
+                UsePlacementFinder::check(krate, self.def_id_to_node_id(def_id))
             } else {
                 (None, FoundUse::No)
             };
@@ -1435,7 +1435,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         let import_suggestions =
             self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, is_expected);
         let (span, found_use) = match parent_scope.module.nearest_parent_mod().as_local() {
-            Some(def_id) => UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id]),
+            Some(def_id) => UsePlacementFinder::check(krate, self.def_id_to_node_id(def_id)),
             None => (None, FoundUse::No),
         };
         show_candidates(
@@ -2550,7 +2550,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 .iter()
                 .filter_map(|item| {
                     let parent_module = self.opt_local_def_id(item.parent_module)?.to_def_id();
-                    Some(StrippedCfgItem { parent_module, name: item.name, cfg: item.cfg.clone() })
+                    Some(StrippedCfgItem {
+                        parent_module,
+                        ident: item.ident,
+                        cfg: item.cfg.clone(),
+                    })
                 })
                 .collect::<Vec<_>>();
             local_items.as_slice()
@@ -2558,12 +2562,12 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             self.tcx.stripped_cfg_items(module.krate)
         };
 
-        for &StrippedCfgItem { parent_module, name, ref cfg } in symbols {
+        for &StrippedCfgItem { parent_module, ident, ref cfg } in symbols {
-            if parent_module != module || name.name != *segment {
+            if parent_module != module || ident.name != *segment {
                 continue;
             }
 
-            let note = errors::FoundItemConfigureOut { span: name.span };
+            let note = errors::FoundItemConfigureOut { span: ident.span };
             err.subdiagnostic(note);
 
             if let MetaItemKind::List(nested) = &cfg.kind

compiler/rustc_resolve/src/ident.rs

@@ -296,9 +296,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     ) -> Option<LexicalScopeBinding<'ra>> {
         assert!(ns == TypeNS || ns == ValueNS);
         let orig_ident = ident;
-        if ident.name == kw::Empty {
-            return Some(LexicalScopeBinding::Res(Res::Err));
-        }
         let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
             // FIXME(jseyfried) improve `Self` hygiene
             let empty_span = ident.span.with_ctxt(SyntaxContext::root());

compiler/rustc_resolve/src/imports.rs

@@ -639,38 +639,38 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 }
 
                 if let Some(glob_binding) = resolution.shadowed_glob {
-                    let binding_id = match binding.kind {
-                        NameBindingKind::Res(res) => {
-                            Some(self.def_id_to_node_id[res.def_id().expect_local()])
-                        }
-                        NameBindingKind::Module(module) => {
-                            Some(self.def_id_to_node_id[module.def_id().expect_local()])
-                        }
-                        NameBindingKind::Import { import, .. } => import.id(),
-                    };
-
                     if binding.res() != Res::Err
                         && glob_binding.res() != Res::Err
                         && let NameBindingKind::Import { import: glob_import, .. } =
                             glob_binding.kind
-                        && let Some(binding_id) = binding_id
                         && let Some(glob_import_id) = glob_import.id()
                         && let glob_import_def_id = self.local_def_id(glob_import_id)
                         && self.effective_visibilities.is_exported(glob_import_def_id)
                         && glob_binding.vis.is_public()
                         && !binding.vis.is_public()
                     {
-                        self.lint_buffer.buffer_lint(
+                        let binding_id = match binding.kind {
-                            HIDDEN_GLOB_REEXPORTS,
+                            NameBindingKind::Res(res) => {
-                            binding_id,
+                                Some(self.def_id_to_node_id(res.def_id().expect_local()))
-                            binding.span,
+                            }
-                            BuiltinLintDiag::HiddenGlobReexports {
+                            NameBindingKind::Module(module) => {
-                                name: key.ident.name.to_string(),
+                                Some(self.def_id_to_node_id(module.def_id().expect_local()))
-                                namespace: key.ns.descr().to_owned(),
+                            }
-                                glob_reexport_span: glob_binding.span,
+                            NameBindingKind::Import { import, .. } => import.id(),
-                                private_item_span: binding.span,
+                        };
-                            },
+                        if let Some(binding_id) = binding_id {
-                        );
+                            self.lint_buffer.buffer_lint(
+                                HIDDEN_GLOB_REEXPORTS,
+                                binding_id,
+                                binding.span,
+                                BuiltinLintDiag::HiddenGlobReexports {
+                                    name: key.ident.name.to_string(),
+                                    namespace: key.ns.descr().to_owned(),
+                                    glob_reexport_span: glob_binding.span,
+                                    private_item_span: binding.span,
+                                },
+                            );
+                        }
                     }
                 }
             }

compiler/rustc_resolve/src/late.rs

@@ -5007,8 +5007,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
             return false;
         }
         let Some(local_did) = did.as_local() else { return true };
-        let Some(node_id) = self.r.def_id_to_node_id.get(local_did) else { return true };
+        !self.r.proc_macros.contains(&local_did)
-        !self.r.proc_macros.contains(node_id)
     }
 
     fn resolve_doc_links(&mut self, attrs: &[Attribute], maybe_exported: MaybeExported<'_>) {

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -2238,7 +2238,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                                     .get(&def_id)
                                     .is_some_and(|sig| sig.has_self),
                                 None => {
-                                    self.r.tcx.fn_arg_names(def_id).first().is_some_and(|&ident| {
+                                    self.r.tcx.fn_arg_idents(def_id).first().is_some_and(|&ident| {
                                         matches!(ident, Some(Ident { name: kw::SelfLower, .. }))
                                     })
                                 }

compiler/rustc_resolve/src/lib.rs

@@ -56,7 +56,6 @@ use rustc_hir::def::{
 };
 use rustc_hir::def_id::{CRATE_DEF_ID, CrateNum, DefId, LOCAL_CRATE, LocalDefId, LocalDefIdMap};
 use rustc_hir::{PrimTy, TraitCandidate};
-use rustc_index::IndexVec;
 use rustc_metadata::creader::{CStore, CrateLoader};
 use rustc_middle::metadata::ModChild;
 use rustc_middle::middle::privacy::EffectiveVisibilities;
@@ -1141,7 +1140,7 @@ pub struct Resolver<'ra, 'tcx> {
     ast_transform_scopes: FxHashMap<LocalExpnId, Module<'ra>>,
     unused_macros: FxIndexMap<LocalDefId, (NodeId, Ident)>,
     /// A map from the macro to all its potentially unused arms.
-    unused_macro_rules: FxIndexMap<LocalDefId, UnordMap<usize, (Ident, Span)>>,
+    unused_macro_rules: FxIndexMap<NodeId, UnordMap<usize, (Ident, Span)>>,
     proc_macro_stubs: FxHashSet<LocalDefId>,
     /// Traces collected during macro resolution and validated when it's complete.
     single_segment_macro_resolutions:
@@ -1184,7 +1183,6 @@ pub struct Resolver<'ra, 'tcx> {
     next_node_id: NodeId,
 
     node_id_to_def_id: NodeMap<Feed<'tcx, LocalDefId>>,
-    def_id_to_node_id: IndexVec<LocalDefId, ast::NodeId>,
 
     /// Indices of unnamed struct or variant fields with unresolved attributes.
     placeholder_field_indices: FxHashMap<NodeId, usize>,
@@ -1202,7 +1200,7 @@ pub struct Resolver<'ra, 'tcx> {
     trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
     /// A list of proc macro LocalDefIds, written out in the order in which
     /// they are declared in the static array generated by proc_macro_harness.
-    proc_macros: Vec<NodeId>,
+    proc_macros: Vec<LocalDefId>,
     confused_type_with_std_module: FxIndexMap<Span, Span>,
     /// Whether lifetime elision was successful.
     lifetime_elision_allowed: FxHashSet<NodeId>,
@@ -1339,12 +1337,12 @@ impl<'tcx> Resolver<'_, 'tcx> {
         expn_id: ExpnId,
         span: Span,
     ) -> TyCtxtFeed<'tcx, LocalDefId> {
-        let data = def_kind.def_path_data(name);
         assert!(
             !self.node_id_to_def_id.contains_key(&node_id),
-            "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
+            "adding a def for node-id {:?}, name {:?}, data {:?} but a previous def exists: {:?}",
             node_id,
-            data,
+            name,
+            def_kind,
             self.tcx.definitions_untracked().def_key(self.node_id_to_def_id[&node_id].key()),
         );
 
@@ -1369,7 +1367,6 @@ impl<'tcx> Resolver<'_, 'tcx> {
             debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id);
             self.node_id_to_def_id.insert(node_id, feed.downgrade());
         }
-        assert_eq!(self.def_id_to_node_id.push(node_id), def_id);
 
         feed
     }
@@ -1385,6 +1382,19 @@ impl<'tcx> Resolver<'_, 'tcx> {
     pub fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
+
+    /// This function is very slow, as it iterates over the entire
+    /// [Resolver::node_id_to_def_id] map just to find the [NodeId]
+    /// that corresponds to the given [LocalDefId]. Only use this in
+    /// diagnostics code paths.
+    fn def_id_to_node_id(&self, def_id: LocalDefId) -> NodeId {
+        self.node_id_to_def_id
+            .items()
+            .filter(|(_, v)| v.key() == def_id)
+            .map(|(k, _)| *k)
+            .get_only()
+            .unwrap()
+    }
 }
 
 impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
@@ -1417,8 +1427,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             &mut Default::default(),
         );
 
-        let mut def_id_to_node_id = IndexVec::default();
-        assert_eq!(def_id_to_node_id.push(CRATE_NODE_ID), CRATE_DEF_ID);
         let mut node_id_to_def_id = NodeMap::default();
         let crate_feed = tcx.create_local_crate_def_id(crate_span);
 
@@ -1553,7 +1561,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             lint_buffer: LintBuffer::default(),
             next_node_id: CRATE_NODE_ID,
             node_id_to_def_id,
-            def_id_to_node_id,
             placeholder_field_indices: Default::default(),
             invocation_parents,
             legacy_const_generic_args: Default::default(),
@@ -1633,7 +1640,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     pub fn into_outputs(self) -> ResolverOutputs {
-        let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
+        let proc_macros = self.proc_macros;
         let expn_that_defined = self.expn_that_defined;
         let extern_crate_map = self.extern_crate_map;
         let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
@@ -1648,7 +1655,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 .filter_map(|item| {
                     let parent_module =
                         self.node_id_to_def_id.get(&item.parent_module)?.key().to_def_id();
-                    Some(StrippedCfgItem { parent_module, name: item.name, cfg: item.cfg })
+                    Some(StrippedCfgItem { parent_module, ident: item.ident, cfg: item.cfg })
                 })
                 .collect(),
         );

compiler/rustc_resolve/src/macros.rs

@@ -323,8 +323,7 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
     }
 
     fn record_macro_rule_usage(&mut self, id: NodeId, rule_i: usize) {
-        let did = self.local_def_id(id);
+        if let Some(rules) = self.unused_macro_rules.get_mut(&id) {
-        if let Some(rules) = self.unused_macro_rules.get_mut(&did) {
             rules.remove(&rule_i);
         }
     }
@@ -337,15 +336,12 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
                 ident.span,
                 BuiltinLintDiag::UnusedMacroDefinition(ident.name),
             );
+            // Do not report unused individual rules if the entire macro is unused
+            self.unused_macro_rules.swap_remove(&node_id);
         }
 
-        for (&def_id, unused_arms) in self.unused_macro_rules.iter() {
+        for (&node_id, unused_arms) in self.unused_macro_rules.iter() {
             for (&arm_i, &(ident, rule_span)) in unused_arms.to_sorted_stable_ord() {
-                if self.unused_macros.contains_key(&def_id) {
-                    // We already lint the entire macro as unused
-                    continue;
-                }
-                let node_id = self.def_id_to_node_id[def_id];
                 self.lint_buffer.buffer_lint(
                     UNUSED_MACRO_RULES,
                     node_id,
@@ -466,11 +462,11 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
     }
 
     fn declare_proc_macro(&mut self, id: NodeId) {
-        self.proc_macros.push(id)
+        self.proc_macros.push(self.local_def_id(id))
     }
 
-    fn append_stripped_cfg_item(&mut self, parent_node: NodeId, name: Ident, cfg: ast::MetaItem) {
+    fn append_stripped_cfg_item(&mut self, parent_node: NodeId, ident: Ident, cfg: ast::MetaItem) {
-        self.stripped_cfg_items.push(StrippedCfgItem { parent_module: parent_node, name, cfg });
+        self.stripped_cfg_items.push(StrippedCfgItem { parent_module: parent_node, ident, cfg });
     }
 
     fn registered_tools(&self) -> &RegisteredTools {
@@ -932,7 +928,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             .invocation_parents
                             .get(&parent_scope.expansion)
                             .map_or(ast::CRATE_NODE_ID, |parent| {
-                                self.def_id_to_node_id[parent.parent_def]
+                                self.def_id_to_node_id(parent.parent_def)
                             });
                         self.lint_buffer.buffer_lint(
                             LEGACY_DERIVE_HELPERS,

compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs

@@ -721,7 +721,8 @@ fn encode_ty_name(tcx: TyCtxt<'_>, def_id: DefId) -> String {
             | hir::definitions::DefPathData::Use
             | hir::definitions::DefPathData::GlobalAsm
             | hir::definitions::DefPathData::MacroNs(..)
-            | hir::definitions::DefPathData::LifetimeNs(..) => {
+            | hir::definitions::DefPathData::LifetimeNs(..)
+            | hir::definitions::DefPathData::AnonAssocTy => {
                 bug!("encode_ty_name: unexpected `{:?}`", disambiguated_data.data);
             }
         });

compiler/rustc_session/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 # tidy-alphabetical-start
 bitflags = "2.4.1"
 getopts = "0.2"
+rand = "0.9.0"
 rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }