Merge pull request #4500 from RalfJung/rustup

Rustup

Cargo.lock

@@ -441,20 +441,6 @@ dependencies = [
  "thiserror 1.0.69",
 ]
 
-[[package]]
-name = "cargo_metadata"
-version = "0.19.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd5eb614ed4c27c5d706420e4320fbe3216ab31fa1c33cd8246ac36dae4479ba"
-dependencies = [
- "camino",
- "cargo-platform 0.1.9",
- "semver",
- "serde",
- "serde_json",
- "thiserror 2.0.12",
-]
-
 [[package]]
 name = "cargo_metadata"
 version = "0.21.0"
@@ -1364,7 +1350,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "askama",
- "cargo_metadata 0.18.1",
+ "cargo_metadata 0.21.0",
  "serde",
  "serde_json",
  "thiserror 1.0.69",
@@ -4255,6 +4241,7 @@ dependencies = [
  "rustc-literal-escaper",
  "rustc_ast",
  "rustc_ast_pretty",
+ "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -5369,7 +5356,7 @@ name = "tidy"
 version = "0.1.0"
 dependencies = [
  "build_helper",
- "cargo_metadata 0.19.2",
+ "cargo_metadata 0.21.0",
  "fluent-syntax",
  "ignore",
  "miropt-test-tools",

compiler/rustc_ast/src/ast.rs

@@ -2849,7 +2849,7 @@ impl InlineAsmOperand {
     }
 }
 
-#[derive(Clone, Copy, Encodable, Decodable, Debug, HashStable_Generic, Walkable)]
+#[derive(Clone, Copy, Encodable, Decodable, Debug, HashStable_Generic, Walkable, PartialEq, Eq)]
 pub enum AsmMacro {
     /// The `asm!` macro
     Asm,

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -416,12 +416,24 @@ pub enum AttributeKind {
     /// Represents `#[pointee]`
     Pointee(Span),
 
+    /// Represents `#[proc_macro]`
+    ProcMacro(Span),
+
+    /// Represents `#[proc_macro_attribute]`
+    ProcMacroAttribute(Span),
+
+    /// Represents `#[proc_macro_derive]`
+    ProcMacroDerive { trait_name: Symbol, helper_attrs: ThinVec<Symbol>, span: Span },
+
     /// Represents `#[rustc_pub_transparent]` (used by the `repr_transparent_external_private_fields` lint).
     PubTransparent(Span),
 
     /// Represents [`#[repr]`](https://doc.rust-lang.org/stable/reference/type-layout.html#representations).
     Repr { reprs: ThinVec<(ReprAttr, Span)>, first_span: Span },
 
+    /// Represents `#[rustc_builtin_macro]`.
+    RustcBuiltinMacro { builtin_name: Option<Symbol>, helper_attrs: ThinVec<Symbol>, span: Span },
+
     /// Represents `#[rustc_layout_scalar_valid_range_end]`.
     RustcLayoutScalarValidRangeEnd(Box<u128>, Span),
 

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -61,8 +61,12 @@ impl AttributeKind {
             PassByValue(..) => Yes,
             Path(..) => No,
             Pointee(..) => No,
+            ProcMacro(..) => No,
+            ProcMacroAttribute(..) => No,
+            ProcMacroDerive { .. } => No,
             PubTransparent(..) => Yes,
             Repr { .. } => No,
+            RustcBuiltinMacro { .. } => Yes,
             RustcLayoutScalarValidRangeEnd(..) => Yes,
             RustcLayoutScalarValidRangeStart(..) => Yes,
             RustcObjectLifetimeDefault => No,

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -41,6 +41,7 @@ pub(crate) mod must_use;
 pub(crate) mod no_implicit_prelude;
 pub(crate) mod non_exhaustive;
 pub(crate) mod path;
+pub(crate) mod proc_macro_attrs;
 pub(crate) mod repr;
 pub(crate) mod rustc_internal;
 pub(crate) mod semantics;

compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs

@@ -0,0 +1,139 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::{Span, Symbol, sym};
+use thin_vec::ThinVec;
+
+use crate::attributes::{
+    AttributeOrder, NoArgsAttributeParser, OnDuplicate, SingleAttributeParser,
+};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct ProcMacroParser;
+impl<S: Stage> NoArgsAttributeParser<S> for ProcMacroParser {
+    const PATH: &[Symbol] = &[sym::proc_macro];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::ProcMacro;
+}
+
+pub(crate) struct ProcMacroAttributeParser;
+impl<S: Stage> NoArgsAttributeParser<S> for ProcMacroAttributeParser {
+    const PATH: &[Symbol] = &[sym::proc_macro_attribute];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::ProcMacroAttribute;
+}
+
+pub(crate) struct ProcMacroDeriveParser;
+impl<S: Stage> SingleAttributeParser<S> for ProcMacroDeriveParser {
+    const PATH: &[Symbol] = &[sym::proc_macro_derive];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const TEMPLATE: AttributeTemplate =
+        template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let (trait_name, helper_attrs) = parse_derive_like(cx, args, true)?;
+        Some(AttributeKind::ProcMacroDerive {
+            trait_name: trait_name.expect("Trait name is mandatory, so it is present"),
+            helper_attrs,
+            span: cx.attr_span,
+        })
+    }
+}
+
+pub(crate) struct RustcBuiltinMacroParser;
+impl<S: Stage> SingleAttributeParser<S> for RustcBuiltinMacroParser {
+    const PATH: &[Symbol] = &[sym::rustc_builtin_macro];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const TEMPLATE: AttributeTemplate =
+        template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let (builtin_name, helper_attrs) = parse_derive_like(cx, args, false)?;
+        Some(AttributeKind::RustcBuiltinMacro { builtin_name, helper_attrs, span: cx.attr_span })
+    }
+}
+
+fn parse_derive_like<S: Stage>(
+    cx: &mut AcceptContext<'_, '_, S>,
+    args: &ArgParser<'_>,
+    trait_name_mandatory: bool,
+) -> Option<(Option<Symbol>, ThinVec<Symbol>)> {
+    let Some(list) = args.list() else {
+        // For #[rustc_builtin_macro], it is permitted to leave out the trait name
+        if args.no_args().is_ok() && !trait_name_mandatory {
+            return Some((None, ThinVec::new()));
+        }
+        cx.expected_list(cx.attr_span);
+        return None;
+    };
+    let mut items = list.mixed();
+
+    // Parse the name of the trait that is derived.
+    let Some(trait_attr) = items.next() else {
+        cx.expected_at_least_one_argument(list.span);
+        return None;
+    };
+    let Some(trait_attr) = trait_attr.meta_item() else {
+        cx.unexpected_literal(trait_attr.span());
+        return None;
+    };
+    let Some(trait_ident) = trait_attr.path().word() else {
+        cx.expected_identifier(trait_attr.path().span());
+        return None;
+    };
+    if !trait_ident.name.can_be_raw() {
+        cx.expected_identifier(trait_ident.span);
+        return None;
+    }
+    if let Err(e) = trait_attr.args().no_args() {
+        cx.expected_no_args(e);
+        return None;
+    };
+
+    // Parse optional attributes
+    let mut attributes = ThinVec::new();
+    if let Some(attrs) = items.next() {
+        let Some(attr_list) = attrs.meta_item() else {
+            cx.expected_list(attrs.span());
+            return None;
+        };
+        if !attr_list.path().word_is(sym::attributes) {
+            cx.expected_specific_argument(attrs.span(), vec!["attributes"]);
+            return None;
+        }
+        let Some(attr_list) = attr_list.args().list() else {
+            cx.expected_list(attrs.span());
+            return None;
+        };
+
+        // Parse item in `attributes(...)` argument
+        for attr in attr_list.mixed() {
+            let Some(attr) = attr.meta_item() else {
+                cx.expected_identifier(attr.span());
+                return None;
+            };
+            if let Err(e) = attr.args().no_args() {
+                cx.expected_no_args(e);
+                return None;
+            };
+            let Some(ident) = attr.path().word() else {
+                cx.expected_identifier(attr.path().span());
+                return None;
+            };
+            if !ident.name.can_be_raw() {
+                cx.expected_identifier(ident.span);
+                return None;
+            }
+            attributes.push(ident.name);
+        }
+    }
+
+    // If anything else is specified, we should reject it
+    if let Some(next) = items.next() {
+        cx.expected_no_args(next.span());
+    }
+
+    Some((Some(trait_ident.name), attributes))
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -38,6 +38,9 @@ use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
 use crate::attributes::non_exhaustive::NonExhaustiveParser;
 use crate::attributes::path::PathParser as PathAttributeParser;
+use crate::attributes::proc_macro_attrs::{
+    ProcMacroAttributeParser, ProcMacroDeriveParser, ProcMacroParser, RustcBuiltinMacroParser,
+};
 use crate::attributes::repr::{AlignParser, ReprParser};
 use crate::attributes::rustc_internal::{
     RustcLayoutScalarValidRangeEnd, RustcLayoutScalarValidRangeStart,
@@ -154,6 +157,8 @@ attribute_parsers!(
         Single<MustUseParser>,
         Single<OptimizeParser>,
         Single<PathAttributeParser>,
+        Single<ProcMacroDeriveParser>,
+        Single<RustcBuiltinMacroParser>,
         Single<RustcForceInlineParser>,
         Single<RustcLayoutScalarValidRangeEnd>,
         Single<RustcLayoutScalarValidRangeStart>,
@@ -186,6 +191,8 @@ attribute_parsers!(
         Single<WithoutArgs<ParenSugarParser>>,
         Single<WithoutArgs<PassByValueParser>>,
         Single<WithoutArgs<PointeeParser>>,
+        Single<WithoutArgs<ProcMacroAttributeParser>>,
+        Single<WithoutArgs<ProcMacroParser>>,
         Single<WithoutArgs<PubTransparentParser>>,
         Single<WithoutArgs<SpecializationTraitParser>>,
         Single<WithoutArgs<StdInternalSymbolParser>>,

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1290,6 +1290,58 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 span,
                 format!("if `{ty}` implemented `Clone`, you could clone the value"),
             );
+        } else if let ty::Adt(_, _) = ty.kind()
+            && let Some(clone_trait) = self.infcx.tcx.lang_items().clone_trait()
+        {
+            // For cases like `Option<NonClone>`, where `Option<T>: Clone` if `T: Clone`, we point
+            // at the types that should be `Clone`.
+            let ocx = ObligationCtxt::new_with_diagnostics(self.infcx);
+            let cause = ObligationCause::misc(expr.span, self.mir_def_id());
+            ocx.register_bound(cause, self.infcx.param_env, ty, clone_trait);
+            let errors = ocx.select_all_or_error();
+            if errors.iter().all(|error| {
+                match error.obligation.predicate.as_clause().and_then(|c| c.as_trait_clause()) {
+                    Some(clause) => match clause.self_ty().skip_binder().kind() {
+                        ty::Adt(def, _) => def.did().is_local() && clause.def_id() == clone_trait,
+                        _ => false,
+                    },
+                    None => false,
+                }
+            }) {
+                let mut type_spans = vec![];
+                let mut types = FxIndexSet::default();
+                for clause in errors
+                    .iter()
+                    .filter_map(|e| e.obligation.predicate.as_clause())
+                    .filter_map(|c| c.as_trait_clause())
+                {
+                    let ty::Adt(def, _) = clause.self_ty().skip_binder().kind() else { continue };
+                    type_spans.push(self.infcx.tcx.def_span(def.did()));
+                    types.insert(
+                        self.infcx
+                            .tcx
+                            .short_string(clause.self_ty().skip_binder(), &mut err.long_ty_path()),
+                    );
+                }
+                let mut span: MultiSpan = type_spans.clone().into();
+                for sp in type_spans {
+                    span.push_span_label(sp, "consider implementing `Clone` for this type");
+                }
+                span.push_span_label(expr.span, "you could clone this value");
+                let types: Vec<_> = types.into_iter().collect();
+                let msg = match &types[..] {
+                    [only] => format!("`{only}`"),
+                    [head @ .., last] => format!(
+                        "{} and `{last}`",
+                        head.iter().map(|t| format!("`{t}`")).collect::<Vec<_>>().join(", ")
+                    ),
+                    [] => unreachable!(),
+                };
+                err.span_note(
+                    span,
+                    format!("if {msg} implemented `Clone`, you could clone the value"),
+                );
+            }
         }
     }
 

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -1,11 +1,13 @@
-use std::mem;
+use std::{mem, slice};
 
 use rustc_ast::ptr::P;
 use rustc_ast::visit::{self, Visitor};
-use rustc_ast::{self as ast, NodeId, attr};
+use rustc_ast::{self as ast, HasNodeId, NodeId, attr};
 use rustc_ast_pretty::pprust;
+use rustc_attr_data_structures::AttributeKind;
+use rustc_attr_parsing::AttributeParser;
 use rustc_errors::DiagCtxtHandle;
-use rustc_expand::base::{ExtCtxt, ResolverExpand, parse_macro_name_and_helper_attrs};
+use rustc_expand::base::{ExtCtxt, ResolverExpand};
 use rustc_expand::expand::{AstFragment, ExpansionConfig};
 use rustc_feature::Features;
 use rustc_session::Session;
@@ -22,7 +24,7 @@ struct ProcMacroDerive {
     trait_name: Symbol,
     function_ident: Ident,
     span: Span,
-    attrs: Vec<Symbol>,
+    attrs: ThinVec<Symbol>,
 }
 
 struct ProcMacroDef {
@@ -41,6 +43,7 @@ struct CollectProcMacros<'a> {
     macros: Vec<ProcMacro>,
     in_root: bool,
     dcx: DiagCtxtHandle<'a>,
+    session: &'a Session,
     source_map: &'a SourceMap,
     is_proc_macro_crate: bool,
     is_test_crate: bool,
@@ -63,6 +66,7 @@ pub fn inject(
         macros: Vec::new(),
         in_root: true,
         dcx,
+        session: sess,
         source_map: sess.source_map(),
         is_proc_macro_crate,
         is_test_crate,
@@ -98,8 +102,18 @@ impl<'a> CollectProcMacros<'a> {
         function_ident: Ident,
         attr: &'a ast::Attribute,
     ) {
-        let Some((trait_name, proc_attrs)) =
-            parse_macro_name_and_helper_attrs(self.dcx, attr, "derive")
+        let Some(rustc_hir::Attribute::Parsed(AttributeKind::ProcMacroDerive {
+            trait_name,
+            helper_attrs,
+            ..
+        })) = AttributeParser::parse_limited(
+            self.session,
+            slice::from_ref(attr),
+            sym::proc_macro_derive,
+            item.span,
+            item.node_id(),
+            None,
+        )
         else {
             return;
         };
@@ -110,7 +124,7 @@ impl<'a> CollectProcMacros<'a> {
                 span: item.span,
                 trait_name,
                 function_ident,
-                attrs: proc_attrs,
+                attrs: helper_attrs,
             }));
         } else {
             let msg = if !self.in_root {

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs

@@ -39,10 +39,7 @@ impl Coords {
 /// or other expansions), and if it does happen then skipping a span or function is
 /// better than an ICE or `llvm-cov` failure that the user might have no way to avoid.
 pub(crate) fn make_coords(source_map: &SourceMap, file: &SourceFile, span: Span) -> Option<Coords> {
-    if span.is_empty() {
-        debug_assert!(false, "can't make coords from empty span: {span:?}");
-        return None;
-    }
+    let span = ensure_non_empty_span(source_map, span)?;
 
     let lo = span.lo();
     let hi = span.hi();
@@ -73,6 +70,29 @@ pub(crate) fn make_coords(source_map: &SourceMap, file: &SourceFile, span: Span)
     })
 }
 
+fn ensure_non_empty_span(source_map: &SourceMap, span: Span) -> Option<Span> {
+    if !span.is_empty() {
+        return Some(span);
+    }
+
+    // The span is empty, so try to enlarge it to cover an adjacent '{' or '}'.
+    source_map
+        .span_to_source(span, |src, start, end| try {
+            // Adjusting span endpoints by `BytePos(1)` is normally a bug,
+            // but in this case we have specifically checked that the character
+            // we're skipping over is one of two specific ASCII characters, so
+            // adjusting by exactly 1 byte is correct.
+            if src.as_bytes().get(end).copied() == Some(b'{') {
+                Some(span.with_hi(span.hi() + BytePos(1)))
+            } else if start > 0 && src.as_bytes()[start - 1] == b'}' {
+                Some(span.with_lo(span.lo() - BytePos(1)))
+            } else {
+                None
+            }
+        })
+        .ok()?
+}
+
 /// If `llvm-cov` sees a source region that is improperly ordered (end < start),
 /// it will immediately exit with a fatal error. To prevent that from happening,
 /// discard regions that are improperly ordered, or might be interpreted in a

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -382,26 +382,16 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                 let width = size.bits();
                 let llty = self.type_ix(width);
                 match name {
-                    sym::ctlz | sym::cttz => {
-                        let y = self.const_bool(false);
-                        let ret = self.call_intrinsic(
-                            format!("llvm.{name}"),
-                            &[llty],
-                            &[args[0].immediate(), y],
-                        );
-
-                        self.intcast(ret, result.layout.llvm_type(self), false)
-                    }
-                    sym::ctlz_nonzero => {
-                        let y = self.const_bool(true);
+                    sym::ctlz | sym::ctlz_nonzero | sym::cttz | sym::cttz_nonzero => {
+                        let y =
+                            self.const_bool(name == sym::ctlz_nonzero || name == sym::cttz_nonzero);
+                        let llvm_name = if name == sym::ctlz || name == sym::ctlz_nonzero {
+                            "llvm.ctlz"
+                        } else {
+                            "llvm.cttz"
+                        };
                         let ret =
-                            self.call_intrinsic("llvm.ctlz", &[llty], &[args[0].immediate(), y]);
-                        self.intcast(ret, result.layout.llvm_type(self), false)
-                    }
-                    sym::cttz_nonzero => {
-                        let y = self.const_bool(true);
-                        let ret =
-                            self.call_intrinsic("llvm.cttz", &[llty], &[args[0].immediate(), y]);
+                            self.call_intrinsic(llvm_name, &[llty], &[args[0].immediate(), y]);
                         self.intcast(ret, result.layout.llvm_type(self), false)
                     }
                     sym::ctpop => {

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -405,6 +405,8 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         ("mips64" | "mips64r6", _) => false,
         // Selection bug <https://github.com/llvm/llvm-project/issues/95471>
         ("nvptx64", _) => false,
+        // Unsupported https://github.com/llvm/llvm-project/issues/121122
+        ("amdgpu", _) => false,
         // ABI bugs <https://github.com/rust-lang/rust/issues/125109> et al. (full
         // list at <https://github.com/rust-lang/rust/issues/116909>)
         ("powerpc" | "powerpc64", _) => false,
@@ -433,6 +435,9 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         // This rules out anything that doesn't have `long double` = `binary128`; <= 32 bits
         // (ld is `f64`), anything other than Linux (Windows and MacOS use `f64`), and `x86`
         // (ld is 80-bit extended precision).
+        //
+        // musl does not implement the symbols required for f128 math at all.
+        _ if target_env == "musl" => false,
         ("x86_64", _) => false,
         (_, "linux") if target_pointer_width == 64 => true,
         _ => false,

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -511,15 +511,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
         err.emit();
     }
 
-    // Any linkage to LLVM intrinsics for now forcibly marks them all as never
-    // unwinds since LLVM sometimes can't handle codegen which `invoke`s
-    // intrinsic functions.
-    if let Some(name) = &codegen_fn_attrs.link_name
-        && name.as_str().starts_with("llvm.")
-    {
-        codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND;
-    }
-
     if let Some(features) = check_tied_features(
         tcx.sess,
         &codegen_fn_attrs

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -1,12 +1,13 @@
 //! An analysis to determine which locals require allocas and
 //! which do not.
 
+use rustc_abi as abi;
 use rustc_data_structures::graph::dominators::Dominators;
 use rustc_index::bit_set::DenseBitSet;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::{self, DefLocation, Location, TerminatorKind, traversal};
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::{bug, span_bug};
 use tracing::debug;
 
@@ -99,63 +100,75 @@ impl<'a, 'b, 'tcx, Bx: BuilderMethods<'b, 'tcx>> LocalAnalyzer<'a, 'b, 'tcx, Bx>
         context: PlaceContext,
         location: Location,
     ) {
-        let cx = self.fx.cx;
+        if !place_ref.projection.is_empty() {
+            const COPY_CONTEXT: PlaceContext =
+                PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy);
 
-        if let Some((place_base, elem)) = place_ref.last_projection() {
-            let mut base_context = if context.is_mutating_use() {
-                PlaceContext::MutatingUse(MutatingUseContext::Projection)
-            } else {
-                PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
-            };
-
-            // Allow uses of projections that are ZSTs or from scalar fields.
-            let is_consume = matches!(
-                context,
-                PlaceContext::NonMutatingUse(
-                    NonMutatingUseContext::Copy | NonMutatingUseContext::Move,
-                )
-            );
-            if is_consume {
-                let base_ty = place_base.ty(self.fx.mir, cx.tcx());
-                let base_ty = self.fx.monomorphize(base_ty);
-
-                // ZSTs don't require any actual memory access.
-                let elem_ty = base_ty.projection_ty(cx.tcx(), self.fx.monomorphize(elem)).ty;
-                let span = self.fx.mir.local_decls[place_ref.local].source_info.span;
-                if cx.spanned_layout_of(elem_ty, span).is_zst() {
-                    return;
+            // `PlaceElem::Index` is the only variant that can mention other `Local`s,
+            // so check for those up-front before any potential short-circuits.
+            for elem in place_ref.projection {
+                if let mir::PlaceElem::Index(index_local) = *elem {
+                    self.visit_local(index_local, COPY_CONTEXT, location);
                 }
+            }
 
-                if let mir::ProjectionElem::Field(..) = elem {
-                    let layout = cx.spanned_layout_of(base_ty.ty, span);
-                    if cx.is_backend_immediate(layout) || cx.is_backend_scalar_pair(layout) {
-                        // Recurse with the same context, instead of `Projection`,
-                        // potentially stopping at non-operand projections,
-                        // which would trigger `not_ssa` on locals.
-                        base_context = context;
+            // If our local is already memory, nothing can make it *more* memory
+            // so we don't need to bother checking the projections further.
+            if self.locals[place_ref.local] == LocalKind::Memory {
+                return;
+            }
+
+            if place_ref.is_indirect_first_projection() {
+                // If this starts with a `Deref`, we only need to record a read of the
+                // pointer being dereferenced, as all the subsequent projections are
+                // working on a place which is always supported. (And because we're
+                // looking at codegen MIR, it can only happen as the first projection.)
+                self.visit_local(place_ref.local, COPY_CONTEXT, location);
+                return;
+            }
+
+            if context.is_mutating_use() {
+                // If it's a mutating use it doesn't matter what the projections are,
+                // if there are *any* then we need a place to write. (For example,
+                // `_1 = Foo()` works in SSA but `_2.0 = Foo()` does not.)
+                let mut_projection = PlaceContext::MutatingUse(MutatingUseContext::Projection);
+                self.visit_local(place_ref.local, mut_projection, location);
+                return;
+            }
+
+            // Scan through to ensure the only projections are those which
+            // `FunctionCx::maybe_codegen_consume_direct` can handle.
+            let base_ty = self.fx.monomorphized_place_ty(mir::PlaceRef::from(place_ref.local));
+            let mut layout = self.fx.cx.layout_of(base_ty);
+            for elem in place_ref.projection {
+                layout = match *elem {
+                    mir::PlaceElem::Field(fidx, ..) => layout.field(self.fx.cx, fidx.as_usize()),
+                    mir::PlaceElem::Downcast(_, vidx)
+                        if let abi::Variants::Single { index: single_variant } =
+                            layout.variants
+                            && vidx == single_variant =>
+                    {
+                        layout.for_variant(self.fx.cx, vidx)
+                    }
+                    mir::PlaceElem::Subtype(subtype_ty) => {
+                        let subtype_ty = self.fx.monomorphize(subtype_ty);
+                        self.fx.cx.layout_of(subtype_ty)
+                    }
+                    _ => {
+                        self.locals[place_ref.local] = LocalKind::Memory;
+                        return;
                     }
                 }
             }
-
-            if let mir::ProjectionElem::Deref = elem {
-                // Deref projections typically only read the pointer.
-                base_context = PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy);
-            }
-
-            self.process_place(&place_base, base_context, location);
-            // HACK(eddyb) this emulates the old `visit_projection_elem`, this
-            // entire `visit_place`-like `process_place` method should be rewritten,
-            // now that we have moved to the "slice of projections" representation.
-            if let mir::ProjectionElem::Index(local) = elem {
-                self.visit_local(
-                    local,
-                    PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
-                    location,
-                );
-            }
-        } else {
-            self.visit_local(place_ref.local, context, location);
+            debug_assert!(
+                !self.fx.cx.is_backend_ref(layout),
+                "Post-projection {place_ref:?} layout should be non-Ref, but it's {layout:?}",
+            );
         }
+
+        // Even with supported projections, we still need to have `visit_local`
+        // check for things that can't be done in SSA (like `SharedBorrow`).
+        self.visit_local(place_ref.local, context, location);
     }
 }
 
@@ -170,11 +183,6 @@ impl<'a, 'b, 'tcx, Bx: BuilderMethods<'b, 'tcx>> Visitor<'tcx> for LocalAnalyzer
 
         if let Some(local) = place.as_local() {
             self.define(local, DefLocation::Assignment(location));
-            if self.locals[local] != LocalKind::Memory {
-                if !self.fx.rvalue_creates_operand(rvalue) {
-                    self.locals[local] = LocalKind::Memory;
-                }
-            }
         } else {
             self.visit_place(place, PlaceContext::MutatingUse(MutatingUseContext::Store), location);
         }

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -335,13 +335,6 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
 
         let val = if field.is_zst() {
             OperandValue::ZeroSized
-        } else if let BackendRepr::SimdVector { .. } = self.layout.backend_repr {
-            // codegen_transmute_operand doesn't support SIMD, but since the previous
-            // check handled ZSTs, the only possible field access into something SIMD
-            // is to the `non_1zst_field` that's the same SIMD. (Other things, even
-            // just padding, would change the wrapper's representation type.)
-            assert_eq!(field.size, self.layout.size);
-            self.val
         } else if field.size == self.layout.size {
             assert_eq!(offset.bytes(), 0);
             fx.codegen_transmute_operand(bx, *self, field)
@@ -928,9 +921,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         match self.locals[place_ref.local] {
             LocalRef::Operand(mut o) => {
-                // Moves out of scalar and scalar pair fields are trivial.
-                for elem in place_ref.projection.iter() {
-                    match elem {
+                // We only need to handle the projections that
+                // `LocalAnalyzer::process_place` let make it here.
+                for elem in place_ref.projection {
+                    match *elem {
                         mir::ProjectionElem::Field(f, _) => {
                             assert!(
                                 !o.layout.ty.is_any_ptr(),
@@ -939,17 +933,18 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             );
                             o = o.extract_field(self, bx, f.index());
                         }
-                        mir::ProjectionElem::Index(_)
-                        | mir::ProjectionElem::ConstantIndex { .. } => {
-                            // ZSTs don't require any actual memory access.
-                            // FIXME(eddyb) deduplicate this with the identical
-                            // checks in `codegen_consume` and `extract_field`.
-                            let elem = o.layout.field(bx.cx(), 0);
-                            if elem.is_zst() {
-                                o = OperandRef::zero_sized(elem);
-                            } else {
-                                return None;
-                            }
+                        mir::PlaceElem::Downcast(_, vidx) => {
+                            debug_assert_eq!(
+                                o.layout.variants,
+                                abi::Variants::Single { index: vidx },
+                            );
+                            let layout = o.layout.for_variant(bx.cx(), vidx);
+                            o = OperandRef { val: o.val, layout }
+                        }
+                        mir::PlaceElem::Subtype(subtype_ty) => {
+                            let subtype_ty = self.monomorphize(subtype_ty);
+                            let layout = self.cx.layout_of(subtype_ty);
+                            o = OperandRef { val: o.val, layout }
                         }
                         _ => return None,
                     }

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -2,12 +2,12 @@ use rustc_abi::{self as abi, FIRST_VARIANT};
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
-use rustc_middle::{bug, mir};
+use rustc_middle::{bug, mir, span_bug};
 use rustc_session::config::OptLevel;
 use tracing::{debug, instrument};
 
 use super::operand::{OperandRef, OperandRefBuilder, OperandValue};
-use super::place::{PlaceRef, codegen_tag_value};
+use super::place::{PlaceRef, PlaceValue, codegen_tag_value};
 use super::{FunctionCx, LocalRef};
 use crate::common::{IntPredicate, TypeKind};
 use crate::traits::*;
@@ -180,7 +180,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             }
 
             _ => {
-                assert!(self.rvalue_creates_operand(rvalue));
                 let temp = self.codegen_rvalue_operand(bx, rvalue);
                 temp.val.store(bx, dest);
             }
@@ -218,17 +217,26 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
     /// Transmutes an `OperandValue` to another `OperandValue`.
     ///
-    /// This is supported only for cases where [`Self::rvalue_creates_operand`]
-    /// returns `true`, and will ICE otherwise. (In particular, anything that
-    /// would need to `alloca` in order to return a `PlaceValue` will ICE,
-    /// expecting those to go via [`Self::codegen_transmute`] instead where
-    /// the destination place is already allocated.)
+    /// This is supported for all cases where the `cast` type is SSA,
+    /// but for non-ZSTs with [`abi::BackendRepr::Memory`] it ICEs.
     pub(crate) fn codegen_transmute_operand(
         &mut self,
         bx: &mut Bx,
         operand: OperandRef<'tcx, Bx::Value>,
         cast: TyAndLayout<'tcx>,
     ) -> OperandValue<Bx::Value> {
+        if let abi::BackendRepr::Memory { .. } = cast.backend_repr
+            && !cast.is_zst()
+        {
+            span_bug!(self.mir.span, "Use `codegen_transmute` to transmute to {cast:?}");
+        }
+
+        // `Layout` is interned, so we can do a cheap check for things that are
+        // exactly the same and thus don't need any handling.
+        if abi::Layout::eq(&operand.layout.layout, &cast.layout) {
+            return operand.val;
+        }
+
         // Check for transmutes that are always UB.
         if operand.layout.size != cast.size
             || operand.layout.is_uninhabited()
@@ -241,11 +249,22 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             return OperandValue::poison(bx, cast);
         }
 
+        // To or from pointers takes different methods, so we use this to restrict
+        // the SimdVector case to types which can be `bitcast` between each other.
+        #[inline]
+        fn vector_can_bitcast(x: abi::Scalar) -> bool {
+            matches!(
+                x,
+                abi::Scalar::Initialized {
+                    value: abi::Primitive::Int(..) | abi::Primitive::Float(..),
+                    ..
+                }
+            )
+        }
+
+        let cx = bx.cx();
         match (operand.val, operand.layout.backend_repr, cast.backend_repr) {
             _ if cast.is_zst() => OperandValue::ZeroSized,
-            (_, _, abi::BackendRepr::Memory { .. }) => {
-                bug!("Cannot `codegen_transmute_operand` to non-ZST memory-ABI output {cast:?}");
-            }
             (OperandValue::Ref(source_place_val), abi::BackendRepr::Memory { .. }, _) => {
                 assert_eq!(source_place_val.llextra, None);
                 // The existing alignment is part of `source_place_val`,
@@ -256,16 +275,46 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 OperandValue::Immediate(imm),
                 abi::BackendRepr::Scalar(from_scalar),
                 abi::BackendRepr::Scalar(to_scalar),
-            ) => OperandValue::Immediate(transmute_scalar(bx, imm, from_scalar, to_scalar)),
+            ) if from_scalar.size(cx) == to_scalar.size(cx) => {
+                OperandValue::Immediate(transmute_scalar(bx, imm, from_scalar, to_scalar))
+            }
+            (
+                OperandValue::Immediate(imm),
+                abi::BackendRepr::SimdVector { element: from_scalar, .. },
+                abi::BackendRepr::SimdVector { element: to_scalar, .. },
+            ) if vector_can_bitcast(from_scalar) && vector_can_bitcast(to_scalar) => {
+                let to_backend_ty = bx.cx().immediate_backend_type(cast);
+                OperandValue::Immediate(bx.bitcast(imm, to_backend_ty))
+            }
             (
                 OperandValue::Pair(imm_a, imm_b),
                 abi::BackendRepr::ScalarPair(in_a, in_b),
                 abi::BackendRepr::ScalarPair(out_a, out_b),
-            ) => OperandValue::Pair(
-                transmute_scalar(bx, imm_a, in_a, out_a),
-                transmute_scalar(bx, imm_b, in_b, out_b),
-            ),
-            _ => bug!("Cannot `codegen_transmute_operand` {operand:?} to {cast:?}"),
+            ) if in_a.size(cx) == out_a.size(cx) && in_b.size(cx) == out_b.size(cx) => {
+                OperandValue::Pair(
+                    transmute_scalar(bx, imm_a, in_a, out_a),
+                    transmute_scalar(bx, imm_b, in_b, out_b),
+                )
+            }
+            _ => {
+                // For any other potentially-tricky cases, make a temporary instead.
+                // If anything else wants the target local to be in memory this won't
+                // be hit, as `codegen_transmute` will get called directly. Thus this
+                // is only for places where everything else wants the operand form,
+                // and thus it's not worth making those places get it from memory.
+                //
+                // Notably, Scalar ⇌ ScalarPair cases go here to avoid padding
+                // and endianness issues, as do SimdVector ones to avoid worrying
+                // about things like f32x8 ⇌ ptrx4 that would need multiple steps.
+                let align = Ord::max(operand.layout.align.abi, cast.align.abi);
+                let size = Ord::max(operand.layout.size, cast.size);
+                let temp = PlaceValue::alloca(bx, size, align);
+                bx.lifetime_start(temp.llval, size);
+                operand.val.store(bx, temp.with_type(operand.layout));
+                let val = bx.load_operand(temp.with_type(cast)).val;
+                bx.lifetime_end(temp.llval, size);
+                val
+            }
         }
     }
 
@@ -326,8 +375,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         bx: &mut Bx,
         rvalue: &mir::Rvalue<'tcx>,
     ) -> OperandRef<'tcx, Bx::Value> {
-        assert!(self.rvalue_creates_operand(rvalue), "cannot codegen {rvalue:?} to operand",);
-
         match *rvalue {
             mir::Rvalue::Cast(ref kind, ref source, mir_cast_ty) => {
                 let operand = self.codegen_operand(bx, source);
@@ -653,8 +700,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 let ty = self.monomorphize(ty);
                 let layout = self.cx.layout_of(ty);
 
-                // `rvalue_creates_operand` has arranged that we only get here if
-                // we can build the aggregate immediate from the field immediates.
                 let mut builder = OperandRefBuilder::new(layout);
                 for (field_idx, field) in fields.iter_enumerated() {
                     let op = self.codegen_operand(bx, field);
@@ -955,69 +1000,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         OperandValue::Pair(val, of)
     }
-
-    /// Returns `true` if the `rvalue` can be computed into an [`OperandRef`],
-    /// rather than needing a full `PlaceRef` for the assignment destination.
-    ///
-    /// This is used by the [`super::analyze`] code to decide which MIR locals
-    /// can stay as SSA values (as opposed to generating `alloca` slots for them).
-    /// As such, some paths here return `true` even where the specific rvalue
-    /// will not actually take the operand path because the result type is such
-    /// that it always gets an `alloca`, but where it's not worth re-checking the
-    /// layout in this code when the right thing will happen anyway.
-    pub(crate) fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>) -> bool {
-        match *rvalue {
-            mir::Rvalue::Cast(mir::CastKind::Transmute, ref operand, cast_ty) => {
-                let operand_ty = operand.ty(self.mir, self.cx.tcx());
-                let cast_layout = self.cx.layout_of(self.monomorphize(cast_ty));
-                let operand_layout = self.cx.layout_of(self.monomorphize(operand_ty));
-                match (operand_layout.backend_repr, cast_layout.backend_repr) {
-                    // When the output will be in memory anyway, just use its place
-                    // (instead of the operand path) unless it's the trivial ZST case.
-                    (_, abi::BackendRepr::Memory { .. }) => cast_layout.is_zst(),
-
-                    // Otherwise (for a non-memory output) if the input is memory
-                    // then we can just read the value from the place.
-                    (abi::BackendRepr::Memory { .. }, _) => true,
-
-                    // When we have scalar immediates, we can only convert things
-                    // where the sizes match, to avoid endianness questions.
-                    (abi::BackendRepr::Scalar(a), abi::BackendRepr::Scalar(b)) =>
-                        a.size(self.cx) == b.size(self.cx),
-                    (abi::BackendRepr::ScalarPair(a0, a1), abi::BackendRepr::ScalarPair(b0, b1)) =>
-                        a0.size(self.cx) == b0.size(self.cx) && a1.size(self.cx) == b1.size(self.cx),
-
-                    // Mixing Scalars and ScalarPairs can get quite complicated when
-                    // padding and undef get involved, so leave that to the memory path.
-                    (abi::BackendRepr::Scalar(_), abi::BackendRepr::ScalarPair(_, _)) |
-                    (abi::BackendRepr::ScalarPair(_, _), abi::BackendRepr::Scalar(_)) => false,
-
-                    // SIMD vectors aren't worth the trouble of dealing with complex
-                    // cases like from vectors of f32 to vectors of pointers or
-                    // from fat pointers to vectors of u16. (See #143194 #110021 ...)
-                    (abi::BackendRepr::SimdVector { .. }, _) | (_, abi::BackendRepr::SimdVector { .. }) => false,
-                }
-            }
-            mir::Rvalue::Ref(..) |
-            mir::Rvalue::CopyForDeref(..) |
-            mir::Rvalue::RawPtr(..) |
-            mir::Rvalue::Len(..) |
-            mir::Rvalue::Cast(..) | // (*)
-            mir::Rvalue::ShallowInitBox(..) | // (*)
-            mir::Rvalue::BinaryOp(..) |
-            mir::Rvalue::UnaryOp(..) |
-            mir::Rvalue::Discriminant(..) |
-            mir::Rvalue::NullaryOp(..) |
-            mir::Rvalue::ThreadLocalRef(_) |
-            mir::Rvalue::Use(..) |
-            mir::Rvalue::Repeat(..) | // (*)
-            mir::Rvalue::Aggregate(..) | // (*)
-            mir::Rvalue::WrapUnsafeBinder(..) => // (*)
-                true,
-        }
-
-        // (*) this is only true if the type is suitable
-    }
 }
 
 /// Transmutes a single scalar value `imm` from `from_scalar` to `to_scalar`.

compiler/rustc_const_eval/messages.ftl

@@ -128,15 +128,15 @@ const_eval_frame_note_inner = inside {$where_ ->
 
 const_eval_frame_note_last = the failure occurred here
 
+const_eval_incompatible_arg_types =
+    calling a function whose parameter #{$arg_idx} has type {$callee_ty} passing argument of type {$caller_ty}
+
 const_eval_incompatible_calling_conventions =
     calling a function with calling convention "{$callee_conv}" using calling convention "{$caller_conv}"
 
 const_eval_incompatible_return_types =
     calling a function with return type {$callee_ty} passing return place of type {$caller_ty}
 
-const_eval_incompatible_types =
-    calling a function with argument of type {$callee_ty} passing data of type {$caller_ty}
-
 const_eval_interior_mutable_borrow_escaping =
     interior mutable shared borrows of temporaries that have their lifetime extended until the end of the program are not allowed
     .label = this borrow of an interior mutable value refers to such a temporary

compiler/rustc_const_eval/src/errors.rs

@@ -500,7 +500,7 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
             InvalidNichedEnumVariantWritten { .. } => {
                 const_eval_invalid_niched_enum_variant_written
             }
-            AbiMismatchArgument { .. } => const_eval_incompatible_types,
+            AbiMismatchArgument { .. } => const_eval_incompatible_arg_types,
             AbiMismatchReturn { .. } => const_eval_incompatible_return_types,
         }
     }
@@ -625,12 +625,16 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
                 diag.arg("data_size", info.data_size);
             }
             InvalidNichedEnumVariantWritten { enum_ty } => {
-                diag.arg("ty", enum_ty.to_string());
+                diag.arg("ty", enum_ty);
             }
-            AbiMismatchArgument { caller_ty, callee_ty }
-            | AbiMismatchReturn { caller_ty, callee_ty } => {
-                diag.arg("caller_ty", caller_ty.to_string());
-                diag.arg("callee_ty", callee_ty.to_string());
+            AbiMismatchArgument { arg_idx, caller_ty, callee_ty } => {
+                diag.arg("arg_idx", arg_idx + 1); // adjust for 1-indexed lists in output
+                diag.arg("caller_ty", caller_ty);
+                diag.arg("callee_ty", callee_ty);
+            }
+            AbiMismatchReturn { caller_ty, callee_ty } => {
+                diag.arg("caller_ty", caller_ty);
+                diag.arg("callee_ty", callee_ty);
             }
         }
     }

compiler/rustc_const_eval/src/interpret/call.rs

@@ -270,6 +270,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             Item = (&'x FnArg<'tcx, M::Provenance>, &'y ArgAbi<'tcx, Ty<'tcx>>),
         >,
         callee_abi: &ArgAbi<'tcx, Ty<'tcx>>,
+        callee_arg_idx: usize,
         callee_arg: &mir::Place<'tcx>,
         callee_ty: Ty<'tcx>,
         already_live: bool,
@@ -298,6 +299,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Check compatibility
         if !self.check_argument_compat(caller_abi, callee_abi)? {
             throw_ub!(AbiMismatchArgument {
+                arg_idx: callee_arg_idx,
                 caller_ty: caller_abi.layout.ty,
                 callee_ty: callee_abi.layout.ty
             });
@@ -424,7 +426,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             // this is a single iterator (that handles `spread_arg`), then
             // `pass_argument` would be the loop body. It takes care to
             // not advance `caller_iter` for ignored arguments.
-            let mut callee_args_abis = callee_fn_abi.args.iter();
+            let mut callee_args_abis = callee_fn_abi.args.iter().enumerate();
             for local in body.args_iter() {
                 // Construct the destination place for this argument. At this point all
                 // locals are still dead, so we cannot construct a `PlaceTy`.
@@ -445,10 +447,11 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                             &[mir::ProjectionElem::Field(FieldIdx::from_usize(i), field_ty)],
                             *self.tcx,
                         );
-                        let callee_abi = callee_args_abis.next().unwrap();
+                        let (idx, callee_abi) = callee_args_abis.next().unwrap();
                         self.pass_argument(
                             &mut caller_args,
                             callee_abi,
+                            idx,
                             &dest,
                             field_ty,
                             /* already_live */ true,
@@ -456,10 +459,11 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     }
                 } else {
                     // Normal argument. Cannot mark it as live yet, it might be unsized!
-                    let callee_abi = callee_args_abis.next().unwrap();
+                    let (idx, callee_abi) = callee_args_abis.next().unwrap();
                     self.pass_argument(
                         &mut caller_args,
                         callee_abi,
+                        idx,
                         &dest,
                         ty,
                         /* already_live */ false,

compiler/rustc_data_structures/src/profiling.rs

@@ -551,6 +551,11 @@ impl SelfProfilerRef {
     pub fn get_self_profiler(&self) -> Option<Arc<SelfProfiler>> {
         self.profiler.clone()
     }
+
+    /// Is expensive recording of query keys and/or function arguments enabled?
+    pub fn is_args_recording_enabled(&self) -> bool {
+        self.enabled() && self.event_filter_mask.intersects(EventFilter::ARGS)
+    }
 }
 
 /// A helper for recording costly arguments to self-profiling events. Used with

compiler/rustc_errors/src/markdown/term.rs

@@ -18,7 +18,7 @@ thread_local! {
 pub(crate) fn entrypoint(stream: &MdStream<'_>, buf: &mut Buffer) -> io::Result<()> {
     #[cfg(not(test))]
     if let Some((w, _)) = termize::dimensions() {
-        WIDTH.with(|c| c.set(std::cmp::min(w, DEFAULT_COLUMN_WIDTH)));
+        WIDTH.set(std::cmp::min(w, DEFAULT_COLUMN_WIDTH));
     }
     write_stream(stream, buf, None, 0)?;
     buf.write_all(b"\n")
@@ -84,7 +84,7 @@ fn write_tt(tt: &MdTree<'_>, buf: &mut Buffer, indent: usize) -> io::Result<()>
             reset_cursor();
         }
         MdTree::HorizontalRule => {
-            (0..WIDTH.with(Cell::get)).for_each(|_| buf.write_all(b"-").unwrap());
+            (0..WIDTH.get()).for_each(|_| buf.write_all(b"-").unwrap());
             reset_cursor();
         }
         MdTree::Heading(n, stream) => {
@@ -121,7 +121,7 @@ fn write_tt(tt: &MdTree<'_>, buf: &mut Buffer, indent: usize) -> io::Result<()>
 
 /// End of that block, just wrap the line
 fn reset_cursor() {
-    CURSOR.with(|cur| cur.set(0));
+    CURSOR.set(0);
 }
 
 /// Change to be generic on Write for testing. If we have a link URL, we don't
@@ -144,7 +144,7 @@ fn write_wrapping<B: io::Write>(
                 buf.write_all(ind_ws)?;
                 cur.set(indent);
             }
-            let ch_count = WIDTH.with(Cell::get) - cur.get();
+            let ch_count = WIDTH.get() - cur.get();
             let mut iter = to_write.char_indices();
             let Some((end_idx, _ch)) = iter.nth(ch_count) else {
                 // Write entire line

compiler/rustc_expand/messages.ftl

@@ -1,26 +1,8 @@
-expand_arg_not_attributes =
-    second argument must be `attributes`
-
-expand_attr_no_arguments =
-    attribute must have either one or two arguments
-
-expand_attribute_meta_item =
-    attribute must be a meta item, not a literal
-
-expand_attribute_single_word =
-    attribute must only be a single word
-
 expand_attributes_on_expressions_experimental =
     attributes on expressions are experimental
     .help_outer_doc = `///` is used for outer documentation comments; for a plain comment, use `//`
     .help_inner_doc = `//!` is used for inner documentation comments; for a plain comment, use `//` by removing the `!` or inserting a space in between them: `// !`
 
-expand_attributes_wrong_form =
-    attribute must be of form: `attributes(foo, bar)`
-
-expand_cannot_be_name_of_macro =
-    `{$trait_ident}` cannot be a name of {$macro_type} macro
-
 expand_collapse_debuginfo_illegal =
     illegal value for attribute #[collapse_debuginfo(no|external|yes)]
 
@@ -71,9 +53,6 @@ expand_glob_delegation_outside_impls =
 expand_glob_delegation_traitless_qpath =
     qualified path without a trait in glob delegation
 
-expand_helper_attribute_name_invalid =
-    `{$name}` cannot be a name of derive helper attribute
-
 expand_incomplete_parse =
     macro expansion ignores {$descr} and any tokens following
     .label = caused by the macro expansion here
@@ -165,12 +144,6 @@ expand_mve_unrecognized_var =
 expand_non_inline_modules_in_proc_macro_input_are_unstable =
     non-inline modules in proc macro input are unstable
 
-expand_not_a_meta_item =
-    not a meta item
-
-expand_only_one_word =
-    must only be one word
-
 expand_proc_macro_back_compat = using an old version of `{$crate_name}`
     .note = older versions of the `{$crate_name}` crate no longer compile; please update to `{$crate_name}` v{$fixed_version}, or switch to one of the `{$crate_name}` alternatives
 

compiler/rustc_expand/src/base.rs

@@ -861,7 +861,7 @@ impl SyntaxExtension {
     /// | (unspecified) | no  | if-ext        | if-ext   | yes |
     /// | external      | no  | if-ext        | if-ext   | yes |
     /// | yes           | yes | yes           | yes      | yes |
-    fn get_collapse_debuginfo(sess: &Session, attrs: &[impl AttributeExt], ext: bool) -> bool {
+    fn get_collapse_debuginfo(sess: &Session, attrs: &[hir::Attribute], ext: bool) -> bool {
         let flag = sess.opts.cg.collapse_macro_debuginfo;
         let attr = ast::attr::find_by_name(attrs, sym::collapse_debuginfo)
             .and_then(|attr| {
@@ -872,7 +872,7 @@ impl SyntaxExtension {
                     .ok()
             })
             .unwrap_or_else(|| {
-                if ast::attr::contains_name(attrs, sym::rustc_builtin_macro) {
+                if find_attr!(attrs, AttributeKind::RustcBuiltinMacro { .. }) {
                     CollapseMacroDebuginfo::Yes
                 } else {
                     CollapseMacroDebuginfo::Unspecified
@@ -915,16 +915,18 @@ impl SyntaxExtension {
         let collapse_debuginfo = Self::get_collapse_debuginfo(sess, attrs, !is_local);
         tracing::debug!(?name, ?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
 
-        let (builtin_name, helper_attrs) = ast::attr::find_by_name(attrs, sym::rustc_builtin_macro)
-            .map(|attr| {
-                // Override `helper_attrs` passed above if it's a built-in macro,
-                // marking `proc_macro_derive` macros as built-in is not a realistic use case.
-                parse_macro_name_and_helper_attrs(sess.dcx(), attr, "built-in").map_or_else(
-                    || (Some(name), Vec::new()),
-                    |(name, helper_attrs)| (Some(name), helper_attrs),
-                )
-            })
-            .unwrap_or_else(|| (None, helper_attrs));
+        let (builtin_name, helper_attrs) = match find_attr!(attrs, AttributeKind::RustcBuiltinMacro { builtin_name, helper_attrs, .. } => (builtin_name, helper_attrs))
+        {
+            // Override `helper_attrs` passed above if it's a built-in macro,
+            // marking `proc_macro_derive` macros as built-in is not a realistic use case.
+            Some((Some(name), helper_attrs)) => {
+                (Some(*name), helper_attrs.iter().copied().collect())
+            }
+            Some((None, _)) => (Some(name), Vec::new()),
+
+            // Not a built-in macro
+            None => (None, helper_attrs),
+        };
 
         let stability = find_attr!(attrs, AttributeKind::Stability { stability, .. } => *stability);
 
@@ -1141,7 +1143,7 @@ pub trait ResolverExpand {
 
     /// Names of specific methods to which glob delegation expands.
     fn glob_delegation_suffixes(
-        &mut self,
+        &self,
         trait_def_id: DefId,
         impl_def_id: LocalDefId,
     ) -> Result<Vec<(Ident, Option<Ident>)>, Indeterminate>;
@@ -1224,6 +1226,7 @@ pub struct ExtCtxt<'a> {
     pub(super) expanded_inert_attrs: MarkedAttrs,
     /// `-Zmacro-stats` data.
     pub macro_stats: FxHashMap<(Symbol, MacroKind), MacroStat>,
+    pub nb_macro_errors: usize,
 }
 
 impl<'a> ExtCtxt<'a> {
@@ -1254,6 +1257,7 @@ impl<'a> ExtCtxt<'a> {
             expanded_inert_attrs: MarkedAttrs::new(),
             buffered_early_lint: vec![],
             macro_stats: Default::default(),
+            nb_macro_errors: 0,
         }
     }
 
@@ -1315,6 +1319,12 @@ impl<'a> ExtCtxt<'a> {
         self.current_expansion.id.expansion_cause()
     }
 
+    /// This method increases the internal macro errors count and then call `trace_macros_diag`.
+    pub fn macro_error_and_trace_macros_diag(&mut self) {
+        self.nb_macro_errors += 1;
+        self.trace_macros_diag();
+    }
+
     pub fn trace_macros_diag(&mut self) {
         for (span, notes) in self.expansions.iter() {
             let mut db = self.dcx().create_note(errors::TraceMacro { span: *span });
@@ -1382,80 +1392,6 @@ pub fn resolve_path(sess: &Session, path: impl Into<PathBuf>, span: Span) -> PRe
     }
 }
 
-pub fn parse_macro_name_and_helper_attrs(
-    dcx: DiagCtxtHandle<'_>,
-    attr: &impl AttributeExt,
-    macro_type: &str,
-) -> Option<(Symbol, Vec<Symbol>)> {
-    // Once we've located the `#[proc_macro_derive]` attribute, verify
-    // that it's of the form `#[proc_macro_derive(Foo)]` or
-    // `#[proc_macro_derive(Foo, attributes(A, ..))]`
-    let list = attr.meta_item_list()?;
-    let ([trait_attr] | [trait_attr, _]) = list.as_slice() else {
-        dcx.emit_err(errors::AttrNoArguments { span: attr.span() });
-        return None;
-    };
-    let Some(trait_attr) = trait_attr.meta_item() else {
-        dcx.emit_err(errors::NotAMetaItem { span: trait_attr.span() });
-        return None;
-    };
-    let trait_ident = match trait_attr.ident() {
-        Some(trait_ident) if trait_attr.is_word() => trait_ident,
-        _ => {
-            dcx.emit_err(errors::OnlyOneWord { span: trait_attr.span });
-            return None;
-        }
-    };
-
-    if !trait_ident.name.can_be_raw() {
-        dcx.emit_err(errors::CannotBeNameOfMacro {
-            span: trait_attr.span,
-            trait_ident,
-            macro_type,
-        });
-    }
-
-    let attributes_attr = list.get(1);
-    let proc_attrs: Vec<_> = if let Some(attr) = attributes_attr {
-        if !attr.has_name(sym::attributes) {
-            dcx.emit_err(errors::ArgumentNotAttributes { span: attr.span() });
-        }
-        attr.meta_item_list()
-            .unwrap_or_else(|| {
-                dcx.emit_err(errors::AttributesWrongForm { span: attr.span() });
-                &[]
-            })
-            .iter()
-            .filter_map(|attr| {
-                let Some(attr) = attr.meta_item() else {
-                    dcx.emit_err(errors::AttributeMetaItem { span: attr.span() });
-                    return None;
-                };
-
-                let ident = match attr.ident() {
-                    Some(ident) if attr.is_word() => ident,
-                    _ => {
-                        dcx.emit_err(errors::AttributeSingleWord { span: attr.span });
-                        return None;
-                    }
-                };
-                if !ident.name.can_be_raw() {
-                    dcx.emit_err(errors::HelperAttributeNameInvalid {
-                        span: attr.span,
-                        name: ident,
-                    });
-                }
-
-                Some(ident.name)
-            })
-            .collect()
-    } else {
-        Vec::new()
-    };
-
-    Some((trait_ident.name, proc_attrs))
-}
-
 /// If this item looks like a specific enums from `rental`, emit a fatal error.
 /// See #73345 and #83125 for more details.
 /// FIXME(#73933): Remove this eventually.

compiler/rustc_expand/src/errors.rs

@@ -78,72 +78,6 @@ pub(crate) struct MacroBodyStability {
     pub head_span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(expand_attr_no_arguments)]
-pub(crate) struct AttrNoArguments {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_not_a_meta_item)]
-pub(crate) struct NotAMetaItem {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_only_one_word)]
-pub(crate) struct OnlyOneWord {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_cannot_be_name_of_macro)]
-pub(crate) struct CannotBeNameOfMacro<'a> {
-    #[primary_span]
-    pub span: Span,
-    pub trait_ident: Ident,
-    pub macro_type: &'a str,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_arg_not_attributes)]
-pub(crate) struct ArgumentNotAttributes {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_attributes_wrong_form)]
-pub(crate) struct AttributesWrongForm {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_attribute_meta_item)]
-pub(crate) struct AttributeMetaItem {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_attribute_single_word)]
-pub(crate) struct AttributeSingleWord {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(expand_helper_attribute_name_invalid)]
-pub(crate) struct HelperAttributeNameInvalid {
-    #[primary_span]
-    pub span: Span,
-    pub name: Ident,
-}
-
 #[derive(Diagnostic)]
 #[diag(expand_feature_removed, code = E0557)]
 #[note]

compiler/rustc_expand/src/expand.rs

@@ -693,7 +693,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             crate_name: self.cx.ecfg.crate_name,
         });
 
-        self.cx.trace_macros_diag();
+        self.cx.macro_error_and_trace_macros_diag();
         guar
     }
 
@@ -707,7 +707,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     ) -> ErrorGuaranteed {
         let guar =
             self.cx.dcx().emit_err(WrongFragmentKind { span, kind: kind.name(), name: &mac.path });
-        self.cx.trace_macros_diag();
+        self.cx.macro_error_and_trace_macros_diag();
         guar
     }
 
@@ -1048,7 +1048,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 }
                 annotate_err_with_kind(&mut err, kind, span);
                 let guar = err.emit();
-                self.cx.trace_macros_diag();
+                self.cx.macro_error_and_trace_macros_diag();
                 kind.dummy(span, guar)
             }
         }

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -299,6 +299,7 @@ enum EofMatcherPositions {
 }
 
 /// Represents the possible results of an attempted parse.
+#[derive(Debug)]
 pub(crate) enum ParseResult<T, F> {
     /// Parsed successfully.
     Success(T),

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -280,7 +280,7 @@ fn expand_macro<'cx>(
             // Retry and emit a better error.
             let (span, guar) =
                 diagnostics::failed_to_match_macro(cx.psess(), sp, def_span, name, arg, rules);
-            cx.trace_macros_diag();
+            cx.macro_error_and_trace_macros_diag();
             DummyResult::any(span, guar)
         }
     }

compiler/rustc_hir/src/hir.rs

@@ -1363,6 +1363,17 @@ impl AttributeExt for Attribute {
             _ => None,
         }
     }
+
+    fn is_proc_macro_attr(&self) -> bool {
+        matches!(
+            self,
+            Attribute::Parsed(
+                AttributeKind::ProcMacro(..)
+                    | AttributeKind::ProcMacroAttribute(..)
+                    | AttributeKind::ProcMacroDerive { .. }
+            )
+        )
+    }
 }
 
 // FIXME(fn_delegation): use function delegation instead of manually forwarding

compiler/rustc_hir_analysis/src/check/check.rs

@@ -767,7 +767,10 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Result<(),
                 DefKind::Static { .. } => {
                     check_static_inhabited(tcx, def_id);
                     check_static_linkage(tcx, def_id);
-                    res = res.and(wfcheck::check_static_item(tcx, def_id));
+                    let ty = tcx.type_of(def_id).instantiate_identity();
+                    res = res.and(wfcheck::check_static_item(
+                        tcx, def_id, ty, /* should_check_for_sync */ true,
+                    ));
                 }
                 DefKind::Const => res = res.and(wfcheck::check_const_item(tcx, def_id)),
                 _ => unreachable!(),

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1180,12 +1180,13 @@ fn check_item_fn(
 }
 
 #[instrument(level = "debug", skip(tcx))]
-pub(super) fn check_static_item(
-    tcx: TyCtxt<'_>,
+pub(crate) fn check_static_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
     item_id: LocalDefId,
+    ty: Ty<'tcx>,
+    should_check_for_sync: bool,
 ) -> Result<(), ErrorGuaranteed> {
     enter_wf_checking_ctxt(tcx, item_id, |wfcx| {
-        let ty = tcx.type_of(item_id).instantiate_identity();
         let span = tcx.ty_span(item_id);
         let item_ty = wfcx.deeply_normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
 
@@ -1212,9 +1213,9 @@ pub(super) fn check_static_item(
         }
 
         // Ensure that the end result is `Sync` in a non-thread local `static`.
-        let should_check_for_sync = tcx.static_mutability(item_id.to_def_id())
-            == Some(hir::Mutability::Not)
+        let should_check_for_sync = should_check_for_sync
             && !is_foreign_item
+            && tcx.static_mutability(item_id.to_def_id()) == Some(hir::Mutability::Not)
             && !tcx.is_thread_local_static(item_id.to_def_id());
 
         if should_check_for_sync {

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -14,6 +14,7 @@ use rustc_middle::{bug, span_bug};
 use rustc_span::{DUMMY_SP, Ident, Span};
 
 use super::{HirPlaceholderCollector, ItemCtxt, bad_placeholder};
+use crate::check::wfcheck::check_static_item;
 use crate::errors::TypeofReservedKeywordUsed;
 use crate::hir_ty_lowering::HirTyLowerer;
 
@@ -217,7 +218,15 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_
                         "static variable",
                     )
                 } else {
-                    icx.lower_ty(ty)
+                    let ty = icx.lower_ty(ty);
+                    // MIR relies on references to statics being scalars.
+                    // Verify that here to avoid ill-formed MIR.
+                    // We skip the `Sync` check to avoid cycles for type-alias-impl-trait,
+                    // relying on the fact that non-Sync statics don't ICE the rest of the compiler.
+                    match check_static_item(tcx, def_id, ty, /* should_check_for_sync */ false) {
+                        Ok(()) => ty,
+                        Err(guar) => Ty::new_error(tcx, guar),
+                    }
                 }
             }
             ItemKind::Const(ident, _, ty, body_id) => {
@@ -275,7 +284,17 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_
                 let args = ty::GenericArgs::identity_for_item(tcx, def_id);
                 Ty::new_fn_def(tcx, def_id.to_def_id(), args)
             }
-            ForeignItemKind::Static(t, _, _) => icx.lower_ty(t),
+            ForeignItemKind::Static(ty, _, _) => {
+                let ty = icx.lower_ty(ty);
+                // MIR relies on references to statics being scalars.
+                // Verify that here to avoid ill-formed MIR.
+                // We skip the `Sync` check to avoid cycles for type-alias-impl-trait,
+                // relying on the fact that non-Sync statics don't ICE the rest of the compiler.
+                match check_static_item(tcx, def_id, ty, /* should_check_for_sync */ false) {
+                    Ok(()) => ty,
+                    Err(guar) => Ty::new_error(tcx, guar),
+                }
+            }
             ForeignItemKind::Type => Ty::new_foreign(tcx, def_id.to_def_id()),
         },
 

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -264,6 +264,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     err.span_label(within_macro_span, "due to this macro variable");
                 }
                 self.suggest_valid_traits(&mut err, item_name, out_of_scope_traits, true);
+                self.suggest_unwrapping_inner_self(&mut err, source, rcvr_ty, item_name);
                 err.emit()
             }
 

compiler/rustc_interface/src/passes.rs

@@ -208,6 +208,10 @@ fn configure_and_expand(
         // Expand macros now!
         let krate = sess.time("expand_crate", || ecx.monotonic_expander().expand_crate(krate));
 
+        if ecx.nb_macro_errors > 0 {
+            sess.dcx().abort_if_errors();
+        }
+
         // The rest is error reporting and stats
 
         sess.psess.buffered_lints.with_lock(|buffered_lints: &mut Vec<BufferedEarlyLint>| {

compiler/rustc_lint/src/builtin.rs

@@ -2870,7 +2870,7 @@ impl<'tcx> LateLintPass<'tcx> for AsmLabels {
         if let hir::Expr {
             kind:
                 hir::ExprKind::InlineAsm(hir::InlineAsm {
-                    asm_macro: AsmMacro::Asm | AsmMacro::NakedAsm,
+                    asm_macro: asm_macro @ (AsmMacro::Asm | AsmMacro::NakedAsm),
                     template_strs,
                     options,
                     ..
@@ -2878,6 +2878,15 @@ impl<'tcx> LateLintPass<'tcx> for AsmLabels {
             ..
         } = expr
         {
+            // Non-generic naked functions are allowed to define arbitrary
+            // labels.
+            if *asm_macro == AsmMacro::NakedAsm {
+                let def_id = expr.hir_id.owner.def_id;
+                if !cx.tcx.generics_of(def_id).requires_monomorphization(cx.tcx) {
+                    return;
+                }
+            }
+
             // asm with `options(raw)` does not do replacement with `{` and `}`.
             let raw = options.contains(InlineAsmOptions::RAW);
 

compiler/rustc_lint/src/late.rs

@@ -356,7 +356,16 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
     let store = unerased_lint_store(tcx.sess);
 
     if store.late_module_passes.is_empty() {
-        late_lint_mod_inner(tcx, module_def_id, context, builtin_lints);
+        // If all builtin lints can be skipped, there is no point in running `late_lint_mod_inner`
+        // at all. This happens often for dependencies built with `--cap-lints=allow`.
+        let dont_need_to_run = tcx.lints_that_dont_need_to_run(());
+        let can_skip_lints = builtin_lints
+            .get_lints()
+            .iter()
+            .all(|lint| dont_need_to_run.contains(&LintId::of(lint)));
+        if !can_skip_lints {
+            late_lint_mod_inner(tcx, module_def_id, context, builtin_lints);
+        }
     } else {
         let builtin_lints = Box::new(builtin_lints) as Box<dyn LateLintPass<'tcx>>;
         let mut binding = store

compiler/rustc_lint/src/levels.rs

@@ -933,6 +933,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     fn check_gated_lint(&self, lint_id: LintId, span: Span, lint_from_cli: bool) -> bool {
         let feature = if let Some(feature) = lint_id.lint.feature_gate
             && !self.features.enabled(feature)
+            && !span.allows_unstable(feature)
         {
             // Lint is behind a feature that is not enabled; eventually return false.
             feature

compiler/rustc_lint/src/passes.rs

@@ -92,7 +92,7 @@ macro_rules! expand_combined_late_lint_pass_methods {
 /// Combines multiple lints passes into a single lint pass, at compile time,
 /// for maximum speed. Each `check_foo` method in `$methods` within this pass
 /// simply calls `check_foo` once per `$pass`. Compare with
-/// `LateLintPassObjects`, which is similar, but combines lint passes at
+/// `RuntimeCombinedLateLintPass`, which is similar, but combines lint passes at
 /// runtime.
 #[macro_export]
 macro_rules! declare_combined_late_lint_pass {
@@ -123,10 +123,10 @@ macro_rules! declare_combined_late_lint_pass {
         #[allow(rustc::lint_pass_impl_without_macro)]
         impl $crate::LintPass for $name {
             fn name(&self) -> &'static str {
-                panic!()
+                stringify!($name)
             }
             fn get_lints(&self) -> LintVec {
-                panic!()
+                $name::get_lints()
             }
         }
     )

compiler/rustc_lint/src/unused.rs

@@ -1340,7 +1340,15 @@ impl EarlyLintPass for UnusedParens {
                 self.with_self_ty_parens = false;
             }
             ast::TyKind::Ref(_, mut_ty) | ast::TyKind::Ptr(mut_ty) => {
-                self.in_no_bounds_pos.insert(mut_ty.ty.id, NoBoundsException::OneBound);
+                // If this type itself appears in no-bounds position, we propagate its
+                // potentially tighter constraint or risk a false posive (issue 143653).
+                let own_constraint = self.in_no_bounds_pos.get(&ty.id);
+                let constraint = match own_constraint {
+                    Some(NoBoundsException::None) => NoBoundsException::None,
+                    Some(NoBoundsException::OneBound) => NoBoundsException::OneBound,
+                    None => NoBoundsException::OneBound,
+                };
+                self.in_no_bounds_pos.insert(mut_ty.ty.id, constraint);
             }
             ast::TyKind::TraitObject(bounds, _) | ast::TyKind::ImplTrait(_, bounds) => {
                 for i in 0..bounds.len() {

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1610,7 +1610,7 @@ extern "C" void LLVMRustPositionBefore(LLVMBuilderRef B, LLVMValueRef Instr) {
 
 extern "C" void LLVMRustPositionAfter(LLVMBuilderRef B, LLVMValueRef Instr) {
   if (auto I = dyn_cast<Instruction>(unwrap<Value>(Instr))) {
-    auto J = I->getNextNonDebugInstruction();
+    auto J = I->getNextNode();
     unwrap(B)->SetInsertPoint(J);
   }
 }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -5,7 +5,7 @@ use std::io::{Read, Seek, Write};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
-use rustc_attr_data_structures::EncodeCrossCrate;
+use rustc_attr_data_structures::{AttributeKind, EncodeCrossCrate, find_attr};
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_data_structures::memmap::{Mmap, MmapMut};
 use rustc_data_structures::sync::{join, par_for_each_in};
@@ -1965,18 +1965,13 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 // Proc-macros may have attributes like `#[allow_internal_unstable]`,
                 // so downstream crates need access to them.
                 let attrs = tcx.hir_attrs(proc_macro);
-                let macro_kind = if ast::attr::contains_name(attrs, sym::proc_macro) {
+                let macro_kind = if find_attr!(attrs, AttributeKind::ProcMacro(..)) {
                     MacroKind::Bang
-                } else if ast::attr::contains_name(attrs, sym::proc_macro_attribute) {
+                } else if find_attr!(attrs, AttributeKind::ProcMacroAttribute(..)) {
                     MacroKind::Attr
-                } else if let Some(attr) = ast::attr::find_by_name(attrs, sym::proc_macro_derive) {
-                    // This unwrap chain should have been checked by the proc-macro harness.
-                    name = attr.meta_item_list().unwrap()[0]
-                        .meta_item()
-                        .unwrap()
-                        .ident()
-                        .unwrap()
-                        .name;
+                } else if let Some(trait_name) = find_attr!(attrs, AttributeKind::ProcMacroDerive { trait_name, ..} => trait_name)
+                {
+                    name = *trait_name;
                     MacroKind::Derive
                 } else {
                     bug!("Unknown proc-macro type for item {:?}", id);
@@ -2124,11 +2119,11 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             };
             let def_id = id.owner_id.to_def_id();
 
-            self.tables.defaultness.set_some(def_id.index, tcx.defaultness(def_id));
-
             if of_trait && let Some(header) = tcx.impl_trait_header(def_id) {
                 record!(self.tables.impl_trait_header[def_id] <- header);
 
+                self.tables.defaultness.set_some(def_id.index, tcx.defaultness(def_id));
+
                 let trait_ref = header.trait_ref.instantiate_identity();
                 let simplified_self_ty = fast_reject::simplify_type(
                     self.tcx,

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -426,7 +426,12 @@ pub enum UndefinedBehaviorInfo<'tcx> {
     /// Trying to set discriminant to the niched variant, but the value does not match.
     InvalidNichedEnumVariantWritten { enum_ty: Ty<'tcx> },
     /// ABI-incompatible argument types.
-    AbiMismatchArgument { caller_ty: Ty<'tcx>, callee_ty: Ty<'tcx> },
+    AbiMismatchArgument {
+        /// The index of the argument whose type is wrong.
+        arg_idx: usize,
+        caller_ty: Ty<'tcx>,
+        callee_ty: Ty<'tcx>,
+    },
     /// ABI-incompatible return types.
     AbiMismatchReturn { caller_ty: Ty<'tcx>, callee_ty: Ty<'tcx> },
 }

compiler/rustc_middle/src/ty/context.rs

@@ -1041,11 +1041,13 @@ const NUM_PREINTERNED_TY_VARS: u32 = 100;
 const NUM_PREINTERNED_FRESH_TYS: u32 = 20;
 const NUM_PREINTERNED_FRESH_INT_TYS: u32 = 3;
 const NUM_PREINTERNED_FRESH_FLOAT_TYS: u32 = 3;
+const NUM_PREINTERNED_ANON_BOUND_TYS_I: u32 = 3;
+const NUM_PREINTERNED_ANON_BOUND_TYS_V: u32 = 20;
 
 // This number may seem high, but it is reached in all but the smallest crates.
 const NUM_PREINTERNED_RE_VARS: u32 = 500;
-const NUM_PREINTERNED_RE_LATE_BOUNDS_I: u32 = 2;
-const NUM_PREINTERNED_RE_LATE_BOUNDS_V: u32 = 20;
+const NUM_PREINTERNED_ANON_RE_BOUNDS_I: u32 = 3;
+const NUM_PREINTERNED_ANON_RE_BOUNDS_V: u32 = 20;
 
 pub struct CommonTypes<'tcx> {
     pub unit: Ty<'tcx>,
@@ -1088,6 +1090,11 @@ pub struct CommonTypes<'tcx> {
 
     /// Pre-interned `Infer(ty::FreshFloatTy(n))` for small values of `n`.
     pub fresh_float_tys: Vec<Ty<'tcx>>,
+
+    /// Pre-interned values of the form:
+    /// `Bound(DebruijnIndex(i), BoundTy { var: v, kind: BoundTyKind::Anon})`
+    /// for small values of `i` and `v`.
+    pub anon_bound_tys: Vec<Vec<Ty<'tcx>>>,
 }
 
 pub struct CommonLifetimes<'tcx> {
@@ -1101,9 +1108,9 @@ pub struct CommonLifetimes<'tcx> {
     pub re_vars: Vec<Region<'tcx>>,
 
     /// Pre-interned values of the form:
-    /// `ReBound(DebruijnIndex(i), BoundRegion { var: v, kind: BrAnon })`
+    /// `ReBound(DebruijnIndex(i), BoundRegion { var: v, kind: BoundRegionKind::Anon })`
     /// for small values of `i` and `v`.
-    pub re_late_bounds: Vec<Vec<Region<'tcx>>>,
+    pub anon_re_bounds: Vec<Vec<Region<'tcx>>>,
 }
 
 pub struct CommonConsts<'tcx> {
@@ -1131,6 +1138,19 @@ impl<'tcx> CommonTypes<'tcx> {
         let fresh_float_tys: Vec<_> =
             (0..NUM_PREINTERNED_FRESH_FLOAT_TYS).map(|n| mk(Infer(ty::FreshFloatTy(n)))).collect();
 
+        let anon_bound_tys = (0..NUM_PREINTERNED_ANON_BOUND_TYS_I)
+            .map(|i| {
+                (0..NUM_PREINTERNED_ANON_BOUND_TYS_V)
+                    .map(|v| {
+                        mk(ty::Bound(
+                            ty::DebruijnIndex::from(i),
+                            ty::BoundTy { var: ty::BoundVar::from(v), kind: ty::BoundTyKind::Anon },
+                        ))
+                    })
+                    .collect()
+            })
+            .collect();
+
         CommonTypes {
             unit: mk(Tuple(List::empty())),
             bool: mk(Bool),
@@ -1161,6 +1181,7 @@ impl<'tcx> CommonTypes<'tcx> {
             fresh_tys,
             fresh_int_tys,
             fresh_float_tys,
+            anon_bound_tys,
         }
     }
 }
@@ -1176,9 +1197,9 @@ impl<'tcx> CommonLifetimes<'tcx> {
         let re_vars =
             (0..NUM_PREINTERNED_RE_VARS).map(|n| mk(ty::ReVar(ty::RegionVid::from(n)))).collect();
 
-        let re_late_bounds = (0..NUM_PREINTERNED_RE_LATE_BOUNDS_I)
+        let anon_re_bounds = (0..NUM_PREINTERNED_ANON_RE_BOUNDS_I)
             .map(|i| {
-                (0..NUM_PREINTERNED_RE_LATE_BOUNDS_V)
+                (0..NUM_PREINTERNED_ANON_RE_BOUNDS_V)
                     .map(|v| {
                         mk(ty::ReBound(
                             ty::DebruijnIndex::from(i),
@@ -1196,7 +1217,7 @@ impl<'tcx> CommonLifetimes<'tcx> {
             re_static: mk(ty::ReStatic),
             re_erased: mk(ty::ReErased),
             re_vars,
-            re_late_bounds,
+            anon_re_bounds,
         }
     }
 }

compiler/rustc_middle/src/ty/mod.rs

@@ -2024,7 +2024,10 @@ impl<'tcx> TyCtxt<'tcx> {
             && let Some(def_id) = def_id.as_local()
             && let outer = self.def_span(def_id).ctxt().outer_expn_data()
             && matches!(outer.kind, ExpnKind::Macro(MacroKind::Derive, _))
-            && self.has_attr(outer.macro_def_id.unwrap(), sym::rustc_builtin_macro)
+            && find_attr!(
+                self.get_all_attrs(outer.macro_def_id.unwrap()),
+                AttributeKind::RustcBuiltinMacro { .. }
+            )
         {
             true
         } else {

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

@@ -86,7 +86,7 @@ macro_rules! define_helper {
 
             impl $helper {
                 pub fn new() -> $helper {
-                    $helper($tl.with(|c| c.replace(true)))
+                    $helper($tl.replace(true))
                 }
             }
 
@@ -100,12 +100,12 @@ macro_rules! define_helper {
 
             impl Drop for $helper {
                 fn drop(&mut self) {
-                    $tl.with(|c| c.set(self.0))
+                    $tl.set(self.0)
                 }
             }
 
             pub fn $name() -> bool {
-                $tl.with(|c| c.get())
+                $tl.get()
             }
         )+
     }

compiler/rustc_middle/src/ty/region.rs

@@ -54,7 +54,7 @@ impl<'tcx> Region<'tcx> {
     ) -> Region<'tcx> {
         // Use a pre-interned one when possible.
         if let ty::BoundRegion { var, kind: ty::BoundRegionKind::Anon } = bound_region
-            && let Some(inner) = tcx.lifetimes.re_late_bounds.get(debruijn.as_usize())
+            && let Some(inner) = tcx.lifetimes.anon_re_bounds.get(debruijn.as_usize())
             && let Some(re) = inner.get(var.as_usize()).copied()
         {
             re

compiler/rustc_middle/src/ty/sty.rs

@@ -485,7 +485,15 @@ impl<'tcx> Ty<'tcx> {
         index: ty::DebruijnIndex,
         bound_ty: ty::BoundTy,
     ) -> Ty<'tcx> {
-        Ty::new(tcx, Bound(index, bound_ty))
+        // Use a pre-interned one when possible.
+        if let ty::BoundTy { var, kind: ty::BoundTyKind::Anon } = bound_ty
+            && let Some(inner) = tcx.types.anon_bound_tys.get(index.as_usize())
+            && let Some(ty) = inner.get(var.as_usize()).copied()
+        {
+            ty
+        } else {
+            Ty::new(tcx, Bound(index, bound_ty))
+        }
     }
 
     #[inline]

compiler/rustc_mir_build/messages.ftl

@@ -86,10 +86,16 @@ mir_build_confused = missing patterns are not covered because `{$variable}` is i
 
 mir_build_const_continue_bad_const = could not determine the target branch for this `#[const_continue]`
     .label = this value is too generic
-    .note = the value must be a literal or a monomorphic const
 
 mir_build_const_continue_missing_value = a `#[const_continue]` must break to a label with a value
 
+mir_build_const_continue_not_const = could not determine the target branch for this `#[const_continue]`
+    .help = try extracting the expression into a `const` item
+
+mir_build_const_continue_not_const_const_block = `const` blocks may use generics, and are not evaluated early enough
+mir_build_const_continue_not_const_const_other = this value must be a literal or a monomorphic const
+mir_build_const_continue_not_const_constant_parameter = constant parameters may use generics, and are not evaluated early enough
+
 mir_build_const_continue_unknown_jump_target = the target of this `#[const_continue]` is not statically known
     .label = this value must be a literal or a monomorphic const
 

compiler/rustc_mir_build/src/builder/scope.rs

@@ -100,7 +100,9 @@ use tracing::{debug, instrument};
 
 use super::matches::BuiltMatchTree;
 use crate::builder::{BlockAnd, BlockAndExtension, BlockFrame, Builder, CFG};
-use crate::errors::{ConstContinueBadConst, ConstContinueUnknownJumpTarget};
+use crate::errors::{
+    ConstContinueBadConst, ConstContinueNotMonomorphicConst, ConstContinueUnknownJumpTarget,
+};
 
 #[derive(Debug)]
 pub(crate) struct Scopes<'tcx> {
@@ -867,7 +869,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             span_bug!(span, "break value must be a scope")
         };
 
-        let constant = match &self.thir[value].kind {
+        let expr = &self.thir[value];
+        let constant = match &expr.kind {
             ExprKind::Adt(box AdtExpr { variant_index, fields, base, .. }) => {
                 assert!(matches!(base, AdtExprBase::None));
                 assert!(fields.is_empty());
@@ -887,7 +890,27 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     ),
                 }
             }
-            _ => self.as_constant(&self.thir[value]),
+
+            ExprKind::Literal { .. }
+            | ExprKind::NonHirLiteral { .. }
+            | ExprKind::ZstLiteral { .. }
+            | ExprKind::NamedConst { .. } => self.as_constant(&self.thir[value]),
+
+            other => {
+                use crate::errors::ConstContinueNotMonomorphicConstReason as Reason;
+
+                let span = expr.span;
+                let reason = match other {
+                    ExprKind::ConstParam { .. } => Reason::ConstantParameter { span },
+                    ExprKind::ConstBlock { .. } => Reason::ConstBlock { span },
+                    _ => Reason::Other { span },
+                };
+
+                self.tcx
+                    .dcx()
+                    .emit_err(ConstContinueNotMonomorphicConst { span: expr.span, reason });
+                return block.unit();
+            }
         };
 
         let break_index = self

compiler/rustc_mir_build/src/errors.rs

@@ -1213,6 +1213,38 @@ pub(crate) struct LoopMatchArmWithGuard {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(mir_build_const_continue_not_const)]
+#[help]
+pub(crate) struct ConstContinueNotMonomorphicConst {
+    #[primary_span]
+    pub span: Span,
+
+    #[subdiagnostic]
+    pub reason: ConstContinueNotMonomorphicConstReason,
+}
+
+#[derive(Subdiagnostic)]
+pub(crate) enum ConstContinueNotMonomorphicConstReason {
+    #[label(mir_build_const_continue_not_const_constant_parameter)]
+    ConstantParameter {
+        #[primary_span]
+        span: Span,
+    },
+
+    #[label(mir_build_const_continue_not_const_const_block)]
+    ConstBlock {
+        #[primary_span]
+        span: Span,
+    },
+
+    #[label(mir_build_const_continue_not_const_const_other)]
+    Other {
+        #[primary_span]
+        span: Span,
+    },
+}
+
 #[derive(Diagnostic)]
 #[diag(mir_build_const_continue_bad_const)]
 pub(crate) struct ConstContinueBadConst {

compiler/rustc_mir_transform/src/coverage/spans.rs

@@ -1,8 +1,7 @@
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::mir;
 use rustc_middle::ty::TyCtxt;
-use rustc_span::source_map::SourceMap;
-use rustc_span::{BytePos, DesugaringKind, ExpnKind, MacroKind, Span};
+use rustc_span::{DesugaringKind, ExpnKind, MacroKind, Span};
 use tracing::instrument;
 
 use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph};
@@ -84,18 +83,8 @@ pub(super) fn extract_refined_covspans<'tcx>(
     // Discard any span that overlaps with a hole.
     discard_spans_overlapping_holes(&mut covspans, &holes);
 
-    // Discard spans that overlap in unwanted ways.
+    // Perform more refinement steps after holes have been dealt with.
     let mut covspans = remove_unwanted_overlapping_spans(covspans);
-
-    // For all empty spans, either enlarge them to be non-empty, or discard them.
-    let source_map = tcx.sess.source_map();
-    covspans.retain_mut(|covspan| {
-        let Some(span) = ensure_non_empty_span(source_map, covspan.span) else { return false };
-        covspan.span = span;
-        true
-    });
-
-    // Merge covspans that can be merged.
     covspans.dedup_by(|b, a| a.merge_if_eligible(b));
 
     code_mappings.extend(covspans.into_iter().map(|Covspan { span, bcb }| {
@@ -241,26 +230,3 @@ fn compare_spans(a: Span, b: Span) -> std::cmp::Ordering {
         // - Both have the same start and span A extends further right
         .then_with(|| Ord::cmp(&a.hi(), &b.hi()).reverse())
 }
-
-fn ensure_non_empty_span(source_map: &SourceMap, span: Span) -> Option<Span> {
-    if !span.is_empty() {
-        return Some(span);
-    }
-
-    // The span is empty, so try to enlarge it to cover an adjacent '{' or '}'.
-    source_map
-        .span_to_source(span, |src, start, end| try {
-            // Adjusting span endpoints by `BytePos(1)` is normally a bug,
-            // but in this case we have specifically checked that the character
-            // we're skipping over is one of two specific ASCII characters, so
-            // adjusting by exactly 1 byte is correct.
-            if src.as_bytes().get(end).copied() == Some(b'{') {
-                Some(span.with_hi(span.hi() + BytePos(1)))
-            } else if start > 0 && src.as_bytes()[start - 1] == b'}' {
-                Some(span.with_lo(span.lo() - BytePos(1)))
-            } else {
-                None
-            }
-        })
-        .ok()?
-}

compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs

@@ -10,8 +10,8 @@ use rustc_type_ir::inherent::*;
 use rustc_type_ir::lang_items::TraitSolverLangItem;
 use rustc_type_ir::solve::SizedTraitKind;
 use rustc_type_ir::{
-    self as ty, Interner, TypeFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt as _,
-    TypeVisitor, TypingMode, Upcast as _, elaborate,
+    self as ty, Interner, TypeFlags, TypeFoldable, TypeSuperVisitable, TypeVisitable,
+    TypeVisitableExt as _, TypeVisitor, TypingMode, Upcast as _, elaborate,
 };
 use tracing::{debug, instrument};
 
@@ -132,6 +132,7 @@ where
         })
         .enter(|ecx| {
             Self::match_assumption(ecx, goal, assumption, |ecx| {
+                ecx.try_evaluate_added_goals()?;
                 source.set(ecx.characterize_param_env_assumption(goal.param_env, assumption)?);
                 ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
             })
@@ -1069,8 +1070,10 @@ where
             } else {
                 ControlFlow::Continue(())
             }
-        } else {
+        } else if ty.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_RE_INFER) {
             ty.super_visit_with(self)
+        } else {
+            ControlFlow::Continue(())
         }
     }
 
@@ -1086,8 +1089,10 @@ where
             } else {
                 ControlFlow::Continue(())
             }
-        } else {
+        } else if ct.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_RE_INFER) {
             ct.super_visit_with(self)
+        } else {
+            ControlFlow::Continue(())
         }
     }
 

compiler/rustc_parse/Cargo.toml

@@ -9,6 +9,7 @@ bitflags = "2.4.1"
 rustc-literal-escaper = "0.0.5"
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
+rustc_attr_parsing = { path = "../rustc_attr_parsing" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }

compiler/rustc_parse/src/validate_attr.rs

@@ -1,11 +1,14 @@
 //! Meta-syntax validation logic of attributes for post-expansion.
 
+use std::slice;
+
 use rustc_ast::token::Delimiter;
 use rustc_ast::tokenstream::DelimSpan;
 use rustc_ast::{
     self as ast, AttrArgs, Attribute, DelimArgs, MetaItem, MetaItemInner, MetaItemKind, NodeId,
     Path, Safety,
 };
+use rustc_attr_parsing::{AttributeParser, Late};
 use rustc_errors::{Applicability, DiagCtxtHandle, FatalError, PResult};
 use rustc_feature::{AttributeSafety, AttributeTemplate, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute};
 use rustc_session::errors::report_lit_error;
@@ -266,67 +269,7 @@ pub fn check_builtin_meta_item(
 ) {
     if !is_attr_template_compatible(&template, &meta.kind) {
         // attrs with new parsers are locally validated so excluded here
-        if matches!(
-            name,
-            sym::inline
-                | sym::export_stable
-                | sym::ffi_const
-                | sym::ffi_pure
-                | sym::rustc_std_internal_symbol
-                | sym::may_dangle
-                | sym::rustc_as_ptr
-                | sym::rustc_pub_transparent
-                | sym::rustc_const_stable_indirect
-                | sym::rustc_force_inline
-                | sym::rustc_confusables
-                | sym::rustc_skip_during_method_dispatch
-                | sym::rustc_pass_by_value
-                | sym::rustc_deny_explicit_impl
-                | sym::rustc_do_not_implement_via_object
-                | sym::rustc_coinductive
-                | sym::const_trait
-                | sym::stable
-                | sym::unstable
-                | sym::rustc_allowed_through_unstable_modules
-                | sym::rustc_specialization_trait
-                | sym::rustc_unsafe_specialization_marker
-                | sym::rustc_allow_incoherent_impl
-                | sym::rustc_coherence_is_core
-                | sym::marker
-                | sym::fundamental
-                | sym::rustc_paren_sugar
-                | sym::type_const
-                | sym::repr
-                // FIXME(#82232, #143834): temporarily renamed to mitigate `#[align]` nameres
-                // ambiguity
-                | sym::rustc_align
-                | sym::deprecated
-                | sym::optimize
-                | sym::pointee
-                | sym::cold
-                | sym::target_feature
-                | sym::rustc_allow_const_fn_unstable
-                | sym::macro_use
-                | sym::macro_escape
-                | sym::naked
-                | sym::no_mangle
-                | sym::non_exhaustive
-                | sym::omit_gdb_pretty_printer_section
-                | sym::path
-                | sym::ignore
-                | sym::must_use
-                | sym::track_caller
-                | sym::link_name
-                | sym::link_ordinal
-                | sym::export_name
-                | sym::rustc_macro_transparency
-                | sym::link_section
-                | sym::rustc_layout_scalar_valid_range_start
-                | sym::rustc_layout_scalar_valid_range_end
-                | sym::no_implicit_prelude
-                | sym::automatically_derived
-                | sym::coverage
-        ) {
+        if AttributeParser::<Late>::is_parsed_attribute(slice::from_ref(&name)) {
             return;
         }
         emit_malformed_attribute(psess, style, meta.span, name, template);

compiler/rustc_passes/src/check_attr.rs

@@ -130,6 +130,22 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         for attr in attrs {
             let mut style = None;
             match attr {
+                Attribute::Parsed(AttributeKind::ProcMacro(_)) => {
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike)
+                }
+                Attribute::Parsed(AttributeKind::ProcMacroAttribute(_)) => {
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::Attribute);
+                }
+                Attribute::Parsed(AttributeKind::ProcMacroDerive { span: attr_span, .. }) => {
+                    self.check_generic_attr(
+                        hir_id,
+                        sym::proc_macro_derive,
+                        *attr_span,
+                        target,
+                        Target::Fn,
+                    );
+                    self.check_proc_macro(hir_id, target, ProcMacroKind::Derive)
+                }
                 Attribute::Parsed(
                     AttributeKind::SkipDuringMethodDispatch { span: attr_span, .. }
                     | AttributeKind::Coinductive(attr_span)
@@ -275,6 +291,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::MacroTransparency(_)
                     | AttributeKind::Pointee(..)
                     | AttributeKind::Dummy
+                    | AttributeKind::RustcBuiltinMacro { .. }
                     | AttributeKind::OmitGdbPrettyPrinterSection,
                 ) => { /* do nothing  */ }
                 Attribute::Parsed(AttributeKind::AsPtr(attr_span)) => {
@@ -373,16 +390,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         [sym::should_panic, ..] => {
                             self.check_generic_attr_unparsed(hir_id, attr, target, Target::Fn)
                         }
-                        [sym::proc_macro, ..] => {
-                            self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike)
-                        }
-                        [sym::proc_macro_attribute, ..] => {
-                            self.check_proc_macro(hir_id, target, ProcMacroKind::Attribute);
-                        }
-                        [sym::proc_macro_derive, ..] => {
-                            self.check_generic_attr_unparsed(hir_id, attr, target, Target::Fn);
-                            self.check_proc_macro(hir_id, target, ProcMacroKind::Derive)
-                        }
                         [sym::autodiff_forward, ..] | [sym::autodiff_reverse, ..] => {
                             self.check_autodiff(hir_id, attr, span, target)
                         }

compiler/rustc_pattern_analysis/src/constructor.rs

@@ -950,9 +950,7 @@ impl<Cx: PatCx> Constructor<Cx> {
                 }
             }
             Never => write!(f, "!")?,
-            Wildcard | Missing | NonExhaustive | Hidden | PrivateUninhabited => {
-                write!(f, "_ : {:?}", ty)?
-            }
+            Wildcard | Missing | NonExhaustive | Hidden | PrivateUninhabited => write!(f, "_")?,
         }
         Ok(())
     }

compiler/rustc_pattern_analysis/src/lib.rs

@@ -57,6 +57,13 @@ pub trait PatCx: Sized + fmt::Debug {
 
     fn is_exhaustive_patterns_feature_on(&self) -> bool;
 
+    /// Whether to ensure the non-exhaustiveness witnesses we report for a complete set. This is
+    /// `false` by default to avoid some exponential blowup cases such as
+    /// <https://github.com/rust-lang/rust/issues/118437>.
+    fn exhaustive_witnesses(&self) -> bool {
+        false
+    }
+
     /// The number of fields for this constructor.
     fn ctor_arity(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> usize;
 

compiler/rustc_pattern_analysis/src/usefulness.rs

@@ -994,7 +994,8 @@ impl<Cx: PatCx> PlaceInfo<Cx> {
         if !missing_ctors.is_empty() && !report_individual_missing_ctors {
             // Report `_` as missing.
             missing_ctors = vec![Constructor::Wildcard];
-        } else if missing_ctors.iter().any(|c| c.is_non_exhaustive()) {
+        } else if missing_ctors.iter().any(|c| c.is_non_exhaustive()) && !cx.exhaustive_witnesses()
+        {
             // We need to report a `_` anyway, so listing other constructors would be redundant.
             // `NonExhaustive` is displayed as `_` just like `Wildcard`, but it will be picked
             // up by diagnostics to add a note about why `_` is required here.
@@ -1747,7 +1748,9 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: PatCx>(
         // `ctor` is *irrelevant* if there's another constructor in `split_ctors` that matches
         // strictly fewer rows. In that case we can sometimes skip it. See the top of the file for
         // details.
-        let ctor_is_relevant = matches!(ctor, Constructor::Missing) || missing_ctors.is_empty();
+        let ctor_is_relevant = matches!(ctor, Constructor::Missing)
+            || missing_ctors.is_empty()
+            || mcx.tycx.exhaustive_witnesses();
         let mut spec_matrix = matrix.specialize_constructor(pcx, &ctor, ctor_is_relevant)?;
         let mut witnesses = ensure_sufficient_stack(|| {
             compute_exhaustiveness_and_usefulness(mcx, &mut spec_matrix)

compiler/rustc_pattern_analysis/tests/common/mod.rs

@@ -1,3 +1,4 @@
+#![allow(dead_code, unreachable_pub)]
 use rustc_pattern_analysis::constructor::{
     Constructor, ConstructorSet, IntRange, MaybeInfiniteInt, RangeEnd, VariantVisibility,
 };
@@ -22,8 +23,10 @@ fn init_tracing() {
         .try_init();
 }
 
+pub(super) const UNIT: Ty = Ty::Tuple(&[]);
+pub(super) const NEVER: Ty = Ty::Enum(&[]);
+
 /// A simple set of types.
-#[allow(dead_code)]
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub(super) enum Ty {
     /// Booleans
@@ -38,6 +41,8 @@ pub(super) enum Ty {
     BigStruct { arity: usize, ty: &'static Ty },
     /// A enum with `arity` variants of type `ty`.
     BigEnum { arity: usize, ty: &'static Ty },
+    /// Like `Enum` but non-exhaustive.
+    NonExhaustiveEnum(&'static [Ty]),
 }
 
 /// The important logic.
@@ -47,7 +52,7 @@ impl Ty {
         match (ctor, *self) {
             (Struct, Ty::Tuple(tys)) => tys.iter().copied().collect(),
             (Struct, Ty::BigStruct { arity, ty }) => (0..arity).map(|_| *ty).collect(),
-            (Variant(i), Ty::Enum(tys)) => vec![tys[*i]],
+            (Variant(i), Ty::Enum(tys) | Ty::NonExhaustiveEnum(tys)) => vec![tys[*i]],
             (Variant(_), Ty::BigEnum { ty, .. }) => vec![*ty],
             (Bool(..) | IntRange(..) | NonExhaustive | Missing | Wildcard, _) => vec![],
             _ => panic!("Unexpected ctor {ctor:?} for type {self:?}"),
@@ -61,6 +66,7 @@ impl Ty {
             Ty::Enum(tys) => tys.iter().all(|ty| ty.is_empty()),
             Ty::BigStruct { arity, ty } => arity != 0 && ty.is_empty(),
             Ty::BigEnum { arity, ty } => arity == 0 || ty.is_empty(),
+            Ty::NonExhaustiveEnum(..) => false,
         }
     }
 
@@ -90,6 +96,19 @@ impl Ty {
                     .collect(),
                 non_exhaustive: false,
             },
+            Ty::NonExhaustiveEnum(tys) => ConstructorSet::Variants {
+                variants: tys
+                    .iter()
+                    .map(|ty| {
+                        if ty.is_empty() {
+                            VariantVisibility::Empty
+                        } else {
+                            VariantVisibility::Visible
+                        }
+                    })
+                    .collect(),
+                non_exhaustive: true,
+            },
             Ty::BigEnum { arity: 0, .. } => ConstructorSet::NoConstructors,
             Ty::BigEnum { arity, ty } => {
                 let vis = if ty.is_empty() {
@@ -113,7 +132,9 @@ impl Ty {
         match (*self, ctor) {
             (Ty::Tuple(..), _) => Ok(()),
             (Ty::BigStruct { .. }, _) => write!(f, "BigStruct"),
-            (Ty::Enum(..), Constructor::Variant(i)) => write!(f, "Enum::Variant{i}"),
+            (Ty::Enum(..) | Ty::NonExhaustiveEnum(..), Constructor::Variant(i)) => {
+                write!(f, "Enum::Variant{i}")
+            }
             (Ty::BigEnum { .. }, Constructor::Variant(i)) => write!(f, "BigEnum::Variant{i}"),
             _ => write!(f, "{:?}::{:?}", self, ctor),
         }
@@ -126,10 +147,11 @@ pub(super) fn compute_match_usefulness<'p>(
     ty: Ty,
     scrut_validity: PlaceValidity,
     complexity_limit: usize,
+    exhaustive_witnesses: bool,
 ) -> Result<UsefulnessReport<'p, Cx>, ()> {
     init_tracing();
     rustc_pattern_analysis::usefulness::compute_match_usefulness(
-        &Cx,
+        &Cx { exhaustive_witnesses },
         arms,
         ty,
         scrut_validity,
@@ -138,7 +160,9 @@ pub(super) fn compute_match_usefulness<'p>(
 }
 
 #[derive(Debug)]
-pub(super) struct Cx;
+pub(super) struct Cx {
+    exhaustive_witnesses: bool,
+}
 
 /// The context for pattern analysis. Forwards anything interesting to `Ty` methods.
 impl PatCx for Cx {
@@ -153,6 +177,10 @@ impl PatCx for Cx {
         false
     }
 
+    fn exhaustive_witnesses(&self) -> bool {
+        self.exhaustive_witnesses
+    }
+
     fn ctor_arity(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> usize {
         ty.sub_tys(ctor).len()
     }
@@ -219,16 +247,18 @@ macro_rules! pats {
     // Entrypoint
     // Parse `type; ..`
     ($ty:expr; $($rest:tt)*) => {{
-        #[allow(unused_imports)]
+        #[allow(unused)]
         use rustc_pattern_analysis::{
             constructor::{Constructor, IntRange, MaybeInfiniteInt, RangeEnd},
-            pat::DeconstructedPat,
+            pat::{DeconstructedPat, IndexedPat},
         };
         let ty = $ty;
         // The heart of the macro is designed to push `IndexedPat`s into a `Vec`, so we work around
         // that.
+        #[allow(unused)]
         let sub_tys = ::std::iter::repeat(&ty);
-        let mut vec = Vec::new();
+        #[allow(unused)]
+        let mut vec: Vec<IndexedPat<_>> = Vec::new();
         pats!(@ctor(vec:vec, sub_tys:sub_tys, idx:0) $($rest)*);
         vec.into_iter().map(|ipat| ipat.pat).collect::<Vec<_>>()
     }};
@@ -263,6 +293,8 @@ macro_rules! pats {
         let ctor = Constructor::Wildcard;
         pats!(@pat($($args)*, ctor:ctor) $($rest)*)
     }};
+    // Nothing
+    (@ctor($($args:tt)*)) => {};
 
     // Integers and int ranges
     (@ctor($($args:tt)*) $($start:literal)?..$end:literal $($rest:tt)*) => {{

compiler/rustc_pattern_analysis/tests/complexity.rs

@@ -16,7 +16,7 @@ fn check(patterns: &[DeconstructedPat<Cx>], complexity_limit: usize) -> Result<(
     let ty = *patterns[0].ty();
     let arms: Vec<_> =
         patterns.iter().map(|pat| MatchArm { pat, has_guard: false, arm_data: () }).collect();
-    compute_match_usefulness(arms.as_slice(), ty, PlaceValidity::ValidOnly, complexity_limit)
+    compute_match_usefulness(arms.as_slice(), ty, PlaceValidity::ValidOnly, complexity_limit, false)
         .map(|_report| ())
 }
 

compiler/rustc_pattern_analysis/tests/exhaustiveness.rs

@@ -11,16 +11,30 @@ use rustc_pattern_analysis::usefulness::PlaceValidity;
 mod common;
 
 /// Analyze a match made of these patterns.
-fn check(patterns: Vec<DeconstructedPat<Cx>>) -> Vec<WitnessPat<Cx>> {
-    let ty = *patterns[0].ty();
+fn run(
+    ty: Ty,
+    patterns: Vec<DeconstructedPat<Cx>>,
+    exhaustive_witnesses: bool,
+) -> Vec<WitnessPat<Cx>> {
     let arms: Vec<_> =
         patterns.iter().map(|pat| MatchArm { pat, has_guard: false, arm_data: () }).collect();
-    let report =
-        compute_match_usefulness(arms.as_slice(), ty, PlaceValidity::ValidOnly, usize::MAX)
-            .unwrap();
+    let report = compute_match_usefulness(
+        arms.as_slice(),
+        ty,
+        PlaceValidity::ValidOnly,
+        usize::MAX,
+        exhaustive_witnesses,
+    )
+    .unwrap();
     report.non_exhaustiveness_witnesses
 }
 
+/// Analyze a match made of these patterns. Panics if there are no patterns
+fn check(patterns: Vec<DeconstructedPat<Cx>>) -> Vec<WitnessPat<Cx>> {
+    let ty = *patterns[0].ty();
+    run(ty, patterns, true)
+}
+
 #[track_caller]
 fn assert_exhaustive(patterns: Vec<DeconstructedPat<Cx>>) {
     let witnesses = check(patterns);
@@ -35,6 +49,26 @@ fn assert_non_exhaustive(patterns: Vec<DeconstructedPat<Cx>>) {
     assert!(!witnesses.is_empty())
 }
 
+use WhichWitnesses::*;
+enum WhichWitnesses {
+    AllOfThem,
+    OnlySome,
+}
+
+#[track_caller]
+/// We take the type as input to support empty matches.
+fn assert_witnesses(
+    which: WhichWitnesses,
+    ty: Ty,
+    patterns: Vec<DeconstructedPat<Cx>>,
+    expected: Vec<&str>,
+) {
+    let exhaustive_wit = matches!(which, AllOfThem);
+    let witnesses = run(ty, patterns, exhaustive_wit);
+    let witnesses: Vec<_> = witnesses.iter().map(|w| format!("{w:?}")).collect();
+    assert_eq!(witnesses, expected)
+}
+
 #[test]
 fn test_int_ranges() {
     let ty = Ty::U8;
@@ -59,6 +93,8 @@ fn test_int_ranges() {
 
 #[test]
 fn test_nested() {
+    // enum E { A(bool), B(bool) }
+    // ty = (E, E)
     let ty = Ty::BigStruct { arity: 2, ty: &Ty::BigEnum { arity: 2, ty: &Ty::Bool } };
     assert_non_exhaustive(pats!(ty;
         Struct(Variant.0, _),
@@ -78,10 +114,74 @@ fn test_nested() {
     ));
 }
 
+#[test]
+fn test_witnesses() {
+    // TY = Option<bool>
+    const TY: Ty = Ty::Enum(&[Ty::Bool, UNIT]);
+    // ty = (Option<bool>, Option<bool>)
+    let ty = Ty::Tuple(&[TY, TY]);
+    assert_witnesses(AllOfThem, ty, vec![], vec!["(_, _)"]);
+    assert_witnesses(
+        OnlySome,
+        ty,
+        pats!(ty;
+            (Variant.0(false), Variant.0(false)),
+        ),
+        vec!["(Enum::Variant1(_), _)"],
+    );
+    assert_witnesses(
+        AllOfThem,
+        ty,
+        pats!(ty;
+            (Variant.0(false), Variant.0(false)),
+        ),
+        vec![
+            "(Enum::Variant0(false), Enum::Variant0(true))",
+            "(Enum::Variant0(false), Enum::Variant1(_))",
+            "(Enum::Variant0(true), _)",
+            "(Enum::Variant1(_), _)",
+        ],
+    );
+    assert_witnesses(
+        OnlySome,
+        ty,
+        pats!(ty;
+            (_, Variant.0(false)),
+        ),
+        vec!["(_, Enum::Variant1(_))"],
+    );
+    assert_witnesses(
+        AllOfThem,
+        ty,
+        pats!(ty;
+            (_, Variant.0(false)),
+        ),
+        vec!["(_, Enum::Variant0(true))", "(_, Enum::Variant1(_))"],
+    );
+
+    let ty = Ty::NonExhaustiveEnum(&[UNIT, UNIT, UNIT]);
+    assert_witnesses(
+        OnlySome,
+        ty,
+        pats!(ty;
+            Variant.0,
+        ),
+        vec!["_"],
+    );
+    assert_witnesses(
+        AllOfThem,
+        ty,
+        pats!(ty;
+            Variant.0,
+        ),
+        vec!["Enum::Variant1(_)", "Enum::Variant2(_)", "_"],
+    );
+}
+
 #[test]
 fn test_empty() {
     // `TY = Result<bool, !>`
-    const TY: Ty = Ty::Enum(&[Ty::Bool, Ty::Enum(&[])]);
+    const TY: Ty = Ty::Enum(&[Ty::Bool, NEVER]);
     assert_exhaustive(pats!(TY;
         Variant.0,
     ));

compiler/rustc_pattern_analysis/tests/intersection.rs

@@ -16,7 +16,7 @@ fn check(patterns: Vec<DeconstructedPat<Cx>>) -> Vec<Vec<usize>> {
     let arms: Vec<_> =
         patterns.iter().map(|pat| MatchArm { pat, has_guard: false, arm_data: () }).collect();
     let report =
-        compute_match_usefulness(arms.as_slice(), ty, PlaceValidity::ValidOnly, usize::MAX)
+        compute_match_usefulness(arms.as_slice(), ty, PlaceValidity::ValidOnly, usize::MAX, false)
             .unwrap();
     report.arm_intersections.into_iter().map(|bitset| bitset.iter().collect()).collect()
 }

compiler/rustc_query_system/src/query/plumbing.rs

@@ -720,7 +720,7 @@ fn incremental_verify_ich_failed<Tcx>(
         static INSIDE_VERIFY_PANIC: Cell<bool> = const { Cell::new(false) };
     };
 
-    let old_in_panic = INSIDE_VERIFY_PANIC.with(|in_panic| in_panic.replace(true));
+    let old_in_panic = INSIDE_VERIFY_PANIC.replace(true);
 
     if old_in_panic {
         tcx.sess().dcx().emit_err(crate::error::Reentrant);
@@ -739,7 +739,7 @@ fn incremental_verify_ich_failed<Tcx>(
         panic!("Found unstable fingerprints for {dep_node:?}: {}", result());
     }
 
-    INSIDE_VERIFY_PANIC.with(|in_panic| in_panic.set(old_in_panic));
+    INSIDE_VERIFY_PANIC.set(old_in_panic);
 }
 
 /// Ensure that either this query has all green inputs or been executed.

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -23,9 +23,9 @@ use rustc_hir::def::{self, *};
 use rustc_hir::def_id::{CRATE_DEF_ID, DefId, LocalDefId};
 use rustc_index::bit_set::DenseBitSet;
 use rustc_metadata::creader::LoadedMacro;
-use rustc_middle::bug;
 use rustc_middle::metadata::ModChild;
 use rustc_middle::ty::{Feed, Visibility};
+use rustc_middle::{bug, span_bug};
 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind};
 use rustc_span::{Ident, Span, Symbol, kw, sym};
 use thin_vec::ThinVec;
@@ -46,30 +46,59 @@ type Res = def::Res<NodeId>;
 impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
     /// otherwise, reports an error.
-    pub(crate) fn define_binding(
+    pub(crate) fn define_binding_local(
         &mut self,
         parent: Module<'ra>,
         ident: Ident,
         ns: Namespace,
         binding: NameBinding<'ra>,
     ) {
-        if let Err(old_binding) = self.try_define(parent, ident, ns, binding, false) {
+        if let Err(old_binding) = self.try_define_local(parent, ident, ns, binding, false) {
             self.report_conflict(parent, ident, ns, old_binding, binding);
         }
     }
 
-    fn define(
+    fn define_local(
         &mut self,
         parent: Module<'ra>,
         ident: Ident,
         ns: Namespace,
         res: Res,
-        vis: Visibility<impl Into<DefId>>,
+        vis: Visibility,
         span: Span,
         expn_id: LocalExpnId,
     ) {
         let binding = self.arenas.new_res_binding(res, vis.to_def_id(), span, expn_id);
-        self.define_binding(parent, ident, ns, binding)
+        self.define_binding_local(parent, ident, ns, binding);
+    }
+
+    fn define_extern(
+        &self,
+        parent: Module<'ra>,
+        ident: Ident,
+        ns: Namespace,
+        res: Res,
+        vis: Visibility<DefId>,
+        span: Span,
+        expn_id: LocalExpnId,
+    ) {
+        let binding = self.arenas.new_res_binding(res, vis, span, expn_id);
+        // Even if underscore names cannot be looked up, we still need to add them to modules,
+        // because they can be fetched by glob imports from those modules, and bring traits
+        // into scope both directly and through glob imports.
+        let key = BindingKey::new_disambiguated(ident, ns, || {
+            parent.underscore_disambiguator.update(|d| d + 1);
+            parent.underscore_disambiguator.get()
+        });
+        if self
+            .resolution_or_default(parent, key)
+            .borrow_mut()
+            .non_glob_binding
+            .replace(binding)
+            .is_some()
+        {
+            span_bug!(span, "an external binding was already defined");
+        }
     }
 
     /// Walks up the tree of definitions starting at `def_id`,
@@ -192,7 +221,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         visitor.parent_scope.macro_rules
     }
 
-    pub(crate) fn build_reduced_graph_external(&mut self, module: Module<'ra>) {
+    pub(crate) fn build_reduced_graph_external(&self, module: Module<'ra>) {
         for child in self.tcx.module_children(module.def_id()) {
             let parent_scope = ParentScope::module(module, self);
             self.build_reduced_graph_for_external_crate_res(child, parent_scope)
@@ -201,7 +230,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
     /// Builds the reduced graph for a single item in an external crate.
     fn build_reduced_graph_for_external_crate_res(
-        &mut self,
+        &self,
         child: &ModChild,
         parent_scope: ParentScope<'ra>,
     ) {
@@ -232,7 +261,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 _,
             )
             | Res::PrimTy(..)
-            | Res::ToolMod => self.define(parent, ident, TypeNS, res, vis, span, expansion),
+            | Res::ToolMod => self.define_extern(parent, ident, TypeNS, res, vis, span, expansion),
             Res::Def(
                 DefKind::Fn
                 | DefKind::AssocFn
@@ -241,9 +270,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 | DefKind::AssocConst
                 | DefKind::Ctor(..),
                 _,
-            ) => self.define(parent, ident, ValueNS, res, vis, span, expansion),
+            ) => self.define_extern(parent, ident, ValueNS, res, vis, span, expansion),
             Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
-                self.define(parent, ident, MacroNS, res, vis, span, expansion)
+                self.define_extern(parent, ident, MacroNS, res, vis, span, expansion)
             }
             Res::Def(
                 DefKind::TyParam
@@ -452,8 +481,10 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                     self.r.per_ns(|this, ns| {
                         if !type_ns_only || ns == TypeNS {
                             let key = BindingKey::new(target, ns);
-                            let mut resolution = this.resolution(current_module, key).borrow_mut();
-                            resolution.single_imports.insert(import);
+                            this.resolution_or_default(current_module, key)
+                                .borrow_mut()
+                                .single_imports
+                                .insert(import);
                         }
                     });
                 }
@@ -709,7 +740,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let expansion = parent_scope.expansion;
 
         // Define a name in the type namespace if it is not anonymous.
-        self.r.define(parent, ident, TypeNS, adt_res, adt_vis, adt_span, expansion);
+        self.r.define_local(parent, ident, TypeNS, adt_res, adt_vis, adt_span, expansion);
         self.r.feed_visibility(feed, adt_vis);
         let def_id = feed.key();
 
@@ -761,7 +792,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             }
 
             ItemKind::Mod(_, ident, ref mod_kind) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
 
                 if let ast::ModKind::Loaded(_, _, _, Err(_)) = mod_kind {
                     self.r.mods_with_parse_errors.insert(def_id);
@@ -780,10 +811,10 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             ItemKind::Const(box ConstItem { ident, .. })
             | ItemKind::Delegation(box Delegation { ident, .. })
             | ItemKind::Static(box StaticItem { ident, .. }) => {
-                self.r.define(parent, ident, ValueNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, ValueNS, res, vis, sp, expansion);
             }
             ItemKind::Fn(box Fn { ident, .. }) => {
-                self.r.define(parent, ident, ValueNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, ValueNS, res, vis, sp, expansion);
 
                 // Functions introducing procedural macros reserve a slot
                 // in the macro namespace as well (see #52225).
@@ -792,11 +823,11 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
 
             // These items live in the type namespace.
             ItemKind::TyAlias(box TyAlias { ident, .. }) | ItemKind::TraitAlias(ident, ..) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
             }
 
             ItemKind::Enum(ident, _, _) | ItemKind::Trait(box ast::Trait { ident, .. }) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
 
                 self.parent_scope.module = self.r.new_local_module(
                     Some(parent),
@@ -848,7 +879,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                     let feed = self.r.feed(ctor_node_id);
                     let ctor_def_id = feed.key();
                     let ctor_res = self.res(ctor_def_id);
-                    self.r.define(parent, ident, ValueNS, ctor_res, ctor_vis, sp, expansion);
+                    self.r.define_local(parent, ident, ValueNS, ctor_res, ctor_vis, sp, expansion);
                     self.r.feed_visibility(feed, ctor_vis);
                     // We need the field visibility spans also for the constructor for E0603.
                     self.insert_field_visibilities_local(ctor_def_id.to_def_id(), vdata.fields());
@@ -972,7 +1003,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                 );
             }
         }
-        self.r.define_binding(parent, ident, TypeNS, imported_binding);
+        self.r.define_binding_local(parent, ident, TypeNS, imported_binding);
     }
 
     /// Constructs the reduced graph for one foreign item.
@@ -989,7 +1020,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let parent = self.parent_scope.module;
         let expansion = self.parent_scope.expansion;
         let vis = self.resolve_visibility(&item.vis);
-        self.r.define(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
+        self.r.define_local(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
         self.r.feed_visibility(feed, vis);
     }
 
@@ -1072,7 +1103,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         if let Some(span) = import_all {
             let import = macro_use_import(self, span, false);
             self.r.potentially_unused_imports.push(import);
-            module.for_each_child(self, |this, ident, ns, binding| {
+            module.for_each_child_mut(self, |this, ident, ns, binding| {
                 if ns == MacroNS {
                     let import = if this.r.is_accessible_from(binding.vis, this.parent_scope.module)
                     {
@@ -1237,7 +1268,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                 });
                 self.r.import_use_map.insert(import, Used::Other);
                 let import_binding = self.r.import(binding, import);
-                self.r.define_binding(self.r.graph_root, ident, MacroNS, import_binding);
+                self.r.define_binding_local(self.r.graph_root, ident, MacroNS, import_binding);
             } else {
                 self.r.check_reserved_macro_name(ident, res);
                 self.insert_unused_macro(ident, def_id, item.id);
@@ -1265,7 +1296,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             if !vis.is_public() {
                 self.insert_unused_macro(ident, def_id, item.id);
             }
-            self.r.define(module, ident, MacroNS, res, vis, span, expansion);
+            self.r.define_local(module, ident, MacroNS, res, vis, span, expansion);
             self.r.feed_visibility(feed, vis);
             self.parent_scope.macro_rules
         }
@@ -1401,7 +1432,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         if ctxt == AssocCtxt::Trait {
             let parent = self.parent_scope.module;
             let expansion = self.parent_scope.expansion;
-            self.r.define(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
+            self.r.define_local(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
         } else if !matches!(&item.kind, AssocItemKind::Delegation(deleg) if deleg.from_glob)
             && ident.name != kw::Underscore
         {
@@ -1489,7 +1520,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let feed = self.r.feed(variant.id);
         let def_id = feed.key();
         let vis = self.resolve_visibility(&variant.vis);
-        self.r.define(parent, ident, TypeNS, self.res(def_id), vis, variant.span, expn_id);
+        self.r.define_local(parent, ident, TypeNS, self.res(def_id), vis, variant.span, expn_id);
         self.r.feed_visibility(feed, vis);
 
         // If the variant is marked as non_exhaustive then lower the visibility to within the crate.
@@ -1505,7 +1536,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             let feed = self.r.feed(ctor_node_id);
             let ctor_def_id = feed.key();
             let ctor_res = self.res(ctor_def_id);
-            self.r.define(parent, ident, ValueNS, ctor_res, ctor_vis, variant.span, expn_id);
+            self.r.define_local(parent, ident, ValueNS, ctor_res, ctor_vis, variant.span, expn_id);
             self.r.feed_visibility(feed, ctor_vis);
         }
 

compiler/rustc_resolve/src/check_unused.rs

@@ -509,9 +509,7 @@ impl Resolver<'_, '_> {
         let mut check_redundant_imports = FxIndexSet::default();
         for module in self.arenas.local_modules().iter() {
             for (_key, resolution) in self.resolutions(*module).borrow().iter() {
-                let resolution = resolution.borrow();
-
-                if let Some(binding) = resolution.best_binding()
+                if let Some(binding) = resolution.borrow().best_binding()
                     && let NameBindingKind::Import { import, .. } = binding.kind
                     && let ImportKind::Single { id, .. } = import.kind
                 {

compiler/rustc_resolve/src/diagnostics.rs

@@ -523,7 +523,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     pub(crate) fn add_module_candidates(
-        &mut self,
+        &self,
         module: Module<'ra>,
         names: &mut Vec<TypoSuggestion>,
         filter_fn: &impl Fn(Res) -> bool,
@@ -1150,7 +1150,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     fn lookup_import_candidates_from_module<FilterFn>(
-        &mut self,
+        &self,
         lookup_ident: Ident,
         namespace: Namespace,
         parent_scope: &ParentScope<'ra>,
@@ -2659,10 +2659,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             return None;
         }
 
-        let resolutions = self.resolutions(crate_module).borrow();
         let binding_key = BindingKey::new(ident, MacroNS);
-        let resolution = resolutions.get(&binding_key)?;
-        let binding = resolution.borrow().binding()?;
+        let binding = self.resolution(crate_module, binding_key)?.binding()?;
         let Res::Def(DefKind::Macro(MacroKind::Bang), _) = binding.res() else {
             return None;
         };

compiler/rustc_resolve/src/effective_visibilities.rs

@@ -114,9 +114,7 @@ impl<'a, 'ra, 'tcx> EffectiveVisibilitiesVisitor<'a, 'ra, 'tcx> {
     /// including their whole reexport chains.
     fn set_bindings_effective_visibilities(&mut self, module_id: LocalDefId) {
         let module = self.r.expect_module(module_id.to_def_id());
-        let resolutions = self.r.resolutions(module);
-
-        for (_, name_resolution) in resolutions.borrow().iter() {
+        for (_, name_resolution) in self.r.resolutions(module).borrow().iter() {
             let Some(mut binding) = name_resolution.borrow().binding() else {
                 continue;
             };

compiler/rustc_resolve/src/ident.rs

@@ -848,8 +848,13 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         };
 
         let key = BindingKey::new(ident, ns);
-        let resolution =
-            self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports.
+        // `try_borrow_mut` is required to ensure exclusive access, even if the resulting binding
+        // doesn't need to be mutable. It will fail when there is a cycle of imports, and without
+        // the exclusive access infinite recursion will crash the compiler with stack overflow.
+        let resolution = &*self
+            .resolution_or_default(module, key)
+            .try_borrow_mut()
+            .map_err(|_| (Determined, Weak::No))?;
 
         // If the primary binding is unusable, search further and return the shadowed glob
         // binding if it exists. What we really want here is having two separate scopes in

compiler/rustc_resolve/src/imports.rs

@@ -334,8 +334,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     /// Define the name or return the existing binding if there is a collision.
-    /// `update` indicates if the definition is a redefinition of an existing binding.
-    pub(crate) fn try_define(
+    pub(crate) fn try_define_local(
         &mut self,
         module: Module<'ra>,
         ident: Ident,
@@ -353,7 +352,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             module.underscore_disambiguator.update(|d| d + 1);
             module.underscore_disambiguator.get()
         });
-        self.update_resolution(module, key, warn_ambiguity, |this, resolution| {
+        self.update_local_resolution(module, key, warn_ambiguity, |this, resolution| {
             if let Some(old_binding) = resolution.best_binding() {
                 if res == Res::Err && old_binding.res() != Res::Err {
                     // Do not override real bindings with `Res::Err`s from error recovery.
@@ -456,7 +455,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
     // Use `f` to mutate the resolution of the name in the module.
     // If the resolution becomes a success, define it in the module's glob importers.
-    fn update_resolution<T, F>(
+    fn update_local_resolution<T, F>(
         &mut self,
         module: Module<'ra>,
         key: BindingKey,
@@ -469,7 +468,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         // Ensure that `resolution` isn't borrowed when defining in the module's glob importers,
         // during which the resolution might end up getting re-defined via a glob cycle.
         let (binding, t, warn_ambiguity) = {
-            let resolution = &mut *self.resolution(module, key).borrow_mut();
+            let resolution = &mut *self.resolution_or_default(module, key).borrow_mut();
             let old_binding = resolution.binding();
 
             let t = f(self, resolution);
@@ -497,7 +496,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             };
             if self.is_accessible_from(binding.vis, scope) {
                 let imported_binding = self.import(binding, *import);
-                let _ = self.try_define(
+                let _ = self.try_define_local(
                     import.parent_scope.module,
                     ident,
                     key.ns,
@@ -523,11 +522,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             let dummy_binding = self.import(dummy_binding, import);
             self.per_ns(|this, ns| {
                 let module = import.parent_scope.module;
-                let _ = this.try_define(module, target, ns, dummy_binding, false);
+                let _ = this.try_define_local(module, target, ns, dummy_binding, false);
                 // Don't remove underscores from `single_imports`, they were never added.
                 if target.name != kw::Underscore {
                     let key = BindingKey::new(target, ns);
-                    this.update_resolution(module, key, false, |_, resolution| {
+                    this.update_local_resolution(module, key, false, |_, resolution| {
                         resolution.single_imports.swap_remove(&import);
                     })
                 }
@@ -651,7 +650,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         for module in self.arenas.local_modules().iter() {
             for (key, resolution) in self.resolutions(*module).borrow().iter() {
                 let resolution = resolution.borrow();
-
                 let Some(binding) = resolution.best_binding() else { continue };
 
                 if let NameBindingKind::Import { import, .. } = binding.kind
@@ -903,14 +901,14 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         }
                         // We need the `target`, `source` can be extracted.
                         let imported_binding = this.import(binding, import);
-                        this.define_binding(parent, target, ns, imported_binding);
+                        this.define_binding_local(parent, target, ns, imported_binding);
                         PendingBinding::Ready(Some(imported_binding))
                     }
                     Err(Determinacy::Determined) => {
                         // Don't remove underscores from `single_imports`, they were never added.
                         if target.name != kw::Underscore {
                             let key = BindingKey::new(target, ns);
-                            this.update_resolution(parent, key, false, |_, resolution| {
+                            this.update_local_resolution(parent, key, false, |_, resolution| {
                                 resolution.single_imports.swap_remove(&import);
                             });
                         }
@@ -1202,41 +1200,39 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             });
 
             return if all_ns_failed {
-                let resolutions = match module {
-                    ModuleOrUniformRoot::Module(module) => Some(self.resolutions(module).borrow()),
-                    _ => None,
-                };
-                let resolutions = resolutions.as_ref().into_iter().flat_map(|r| r.iter());
-                let names = resolutions
-                    .filter_map(|(BindingKey { ident: i, .. }, resolution)| {
-                        if i.name == ident.name {
-                            return None;
-                        } // Never suggest the same name
-                        match *resolution.borrow() {
-                            ref resolution
-                                if let Some(name_binding) = resolution.best_binding() =>
-                            {
-                                match name_binding.kind {
-                                    NameBindingKind::Import { binding, .. } => {
-                                        match binding.kind {
-                                            // Never suggest the name that has binding error
-                                            // i.e., the name that cannot be previously resolved
-                                            NameBindingKind::Res(Res::Err) => None,
-                                            _ => Some(i.name),
+                let names = match module {
+                    ModuleOrUniformRoot::Module(module) => {
+                        self.resolutions(module)
+                            .borrow()
+                            .iter()
+                            .filter_map(|(BindingKey { ident: i, .. }, resolution)| {
+                                if i.name == ident.name {
+                                    return None;
+                                } // Never suggest the same name
+
+                                let resolution = resolution.borrow();
+                                if let Some(name_binding) = resolution.best_binding() {
+                                    match name_binding.kind {
+                                        NameBindingKind::Import { binding, .. } => {
+                                            match binding.kind {
+                                                // Never suggest the name that has binding error
+                                                // i.e., the name that cannot be previously resolved
+                                                NameBindingKind::Res(Res::Err) => None,
+                                                _ => Some(i.name),
+                                            }
                                         }
+                                        _ => Some(i.name),
                                     }
-                                    _ => Some(i.name),
+                                } else if resolution.single_imports.is_empty() {
+                                    None
+                                } else {
+                                    Some(i.name)
                                 }
-                            }
-                            NameResolution { ref single_imports, .. }
-                                if single_imports.is_empty() =>
-                            {
-                                None
-                            }
-                            _ => Some(i.name),
-                        }
-                    })
-                    .collect::<Vec<Symbol>>();
+                            })
+                            .collect()
+                    }
+                    _ => Vec::new(),
+                };
 
                 let lev_suggestion =
                     find_best_match_for_name(&names, ident.name, None).map(|suggestion| {
@@ -1517,10 +1513,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 let imported_binding = self.import(binding, import);
                 let warn_ambiguity = self
                     .resolution(import.parent_scope.module, key)
-                    .borrow()
-                    .binding()
+                    .and_then(|r| r.binding())
                     .is_some_and(|binding| binding.warn_ambiguity_recursive());
-                let _ = self.try_define(
+                let _ = self.try_define_local(
                     import.parent_scope.module,
                     key.ident,
                     key.ns,

compiler/rustc_resolve/src/late.rs

@@ -3449,8 +3449,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         };
         ident.span.normalize_to_macros_2_0_and_adjust(module.expansion);
         let key = BindingKey::new(ident, ns);
-        let mut binding =
-            self.r.resolution(module, key).try_borrow().ok().and_then(|r| r.best_binding());
+        let mut binding = self.r.resolution(module, key).and_then(|r| r.best_binding());
         debug!(?binding);
         if binding.is_none() {
             // We could not find the trait item in the correct namespace.
@@ -3461,8 +3460,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 _ => ns,
             };
             let key = BindingKey::new(ident, ns);
-            binding =
-                self.r.resolution(module, key).try_borrow().ok().and_then(|r| r.best_binding());
+            binding = self.r.resolution(module, key).and_then(|r| r.best_binding());
             debug!(?binding);
         }
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1461,15 +1461,17 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
                 self.resolve_path(mod_path, None, None)
             {
-                let resolutions = self.r.resolutions(module).borrow();
-                let targets: Vec<_> = resolutions
+                let targets: Vec<_> = self
+                    .r
+                    .resolutions(module)
+                    .borrow()
                     .iter()
                     .filter_map(|(key, resolution)| {
                         resolution
                             .borrow()
                             .best_binding()
                             .map(|binding| binding.res())
-                            .and_then(|res| if filter_fn(res) { Some((key, res)) } else { None })
+                            .and_then(|res| if filter_fn(res) { Some((*key, res)) } else { None })
                     })
                     .collect();
                 if let [target] = targets.as_slice() {
@@ -2300,8 +2302,9 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             return None;
         }
 
-        let resolutions = self.r.resolutions(*module);
-        let targets = resolutions
+        let targets = self
+            .r
+            .resolutions(*module)
             .borrow()
             .iter()
             .filter_map(|(key, res)| {
@@ -2630,7 +2633,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         false
     }
 
-    fn find_module(&mut self, def_id: DefId) -> Option<(Module<'ra>, ImportSuggestion)> {
+    fn find_module(&self, def_id: DefId) -> Option<(Module<'ra>, ImportSuggestion)> {
         let mut result = None;
         let mut seen_modules = FxHashSet::default();
         let root_did = self.r.graph_root.def_id();
@@ -2687,7 +2690,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         result
     }
 
-    fn collect_enum_ctors(&mut self, def_id: DefId) -> Option<Vec<(Path, DefId, CtorKind)>> {
+    fn collect_enum_ctors(&self, def_id: DefId) -> Option<Vec<(Path, DefId, CtorKind)>> {
         self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| {
             let mut variants = Vec::new();
             enum_module.for_each_child(self.r, |_, ident, _, name_binding| {
@@ -2704,7 +2707,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
 
     /// Adds a suggestion for using an enum's variant when an enum is used instead.
     fn suggest_using_enum_variant(
-        &mut self,
+        &self,
         err: &mut Diag<'_>,
         source: PathSource<'_, '_, '_>,
         def_id: DefId,

compiler/rustc_resolve/src/lib.rs

@@ -21,7 +21,7 @@
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
 
-use std::cell::{Cell, RefCell};
+use std::cell::{Cell, Ref, RefCell};
 use std::collections::BTreeSet;
 use std::fmt;
 use std::sync::Arc;
@@ -656,11 +656,23 @@ impl<'ra> ModuleData<'ra> {
 }
 
 impl<'ra> Module<'ra> {
-    fn for_each_child<'tcx, R, F>(self, resolver: &mut R, mut f: F)
-    where
-        R: AsMut<Resolver<'ra, 'tcx>>,
-        F: FnMut(&mut R, Ident, Namespace, NameBinding<'ra>),
-    {
+    fn for_each_child<'tcx, R: AsRef<Resolver<'ra, 'tcx>>>(
+        self,
+        resolver: &R,
+        mut f: impl FnMut(&R, Ident, Namespace, NameBinding<'ra>),
+    ) {
+        for (key, name_resolution) in resolver.as_ref().resolutions(self).borrow().iter() {
+            if let Some(binding) = name_resolution.borrow().best_binding() {
+                f(resolver, key.ident, key.ns, binding);
+            }
+        }
+    }
+
+    fn for_each_child_mut<'tcx, R: AsMut<Resolver<'ra, 'tcx>>>(
+        self,
+        resolver: &mut R,
+        mut f: impl FnMut(&mut R, Ident, Namespace, NameBinding<'ra>),
+    ) {
         for (key, name_resolution) in resolver.as_mut().resolutions(self).borrow().iter() {
             if let Some(binding) = name_resolution.borrow().best_binding() {
                 f(resolver, key.ident, key.ns, binding);
@@ -669,10 +681,7 @@ impl<'ra> Module<'ra> {
     }
 
     /// This modifies `self` in place. The traits will be stored in `self.traits`.
-    fn ensure_traits<'tcx, R>(self, resolver: &mut R)
-    where
-        R: AsMut<Resolver<'ra, 'tcx>>,
-    {
+    fn ensure_traits<'tcx>(self, resolver: &impl AsRef<Resolver<'ra, 'tcx>>) {
         let mut traits = self.traits.borrow_mut();
         if traits.is_none() {
             let mut collected_traits = Vec::new();
@@ -681,7 +690,7 @@ impl<'ra> Module<'ra> {
                     return;
                 }
                 if let Res::Def(DefKind::Trait | DefKind::TraitAlias, def_id) = binding.res() {
-                    collected_traits.push((name, binding, r.as_mut().get_module(def_id)))
+                    collected_traits.push((name, binding, r.as_ref().get_module(def_id)))
                 }
             });
             *traits = Some(collected_traits.into_boxed_slice());
@@ -1340,6 +1349,12 @@ impl<'ra, 'tcx> AsMut<Resolver<'ra, 'tcx>> for Resolver<'ra, 'tcx> {
     }
 }
 
+impl<'ra, 'tcx> AsRef<Resolver<'ra, 'tcx>> for Resolver<'ra, 'tcx> {
+    fn as_ref(&self) -> &Resolver<'ra, 'tcx> {
+        self
+    }
+}
+
 impl<'tcx> Resolver<'_, 'tcx> {
     fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
         self.opt_feed(node).map(|f| f.key())
@@ -1861,7 +1876,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     // We don't reject trait aliases (`trait_module == None`) because we don't have access to their
     // associated items.
     fn trait_may_have_item(
-        &mut self,
+        &self,
         trait_module: Option<Module<'ra>>,
         assoc_item: Option<(Symbol, Namespace)>,
     ) -> bool {
@@ -1893,7 +1908,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         import_ids
     }
 
-    fn resolutions(&mut self, module: Module<'ra>) -> &'ra Resolutions<'ra> {
+    fn resolutions(&self, module: Module<'ra>) -> &'ra Resolutions<'ra> {
         if module.populate_on_access.get() {
             module.populate_on_access.set(false);
             self.build_reduced_graph_external(module);
@@ -1902,12 +1917,19 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     fn resolution(
-        &mut self,
+        &self,
+        module: Module<'ra>,
+        key: BindingKey,
+    ) -> Option<Ref<'ra, NameResolution<'ra>>> {
+        self.resolutions(module).borrow().get(&key).map(|resolution| resolution.borrow())
+    }
+
+    fn resolution_or_default(
+        &self,
         module: Module<'ra>,
         key: BindingKey,
     ) -> &'ra RefCell<NameResolution<'ra>> {
-        *self
-            .resolutions(module)
+        self.resolutions(module)
             .borrow_mut()
             .entry(key)
             .or_insert_with(|| self.arenas.alloc_name_resolution())

compiler/rustc_resolve/src/macros.rs

@@ -511,7 +511,7 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
     }
 
     fn glob_delegation_suffixes(
-        &mut self,
+        &self,
         trait_def_id: DefId,
         impl_def_id: LocalDefId,
     ) -> Result<Vec<(Ident, Option<Ident>)>, Indeterminate> {

compiler/rustc_session/src/session.rs

@@ -313,6 +313,7 @@ impl Session {
             || self.opts.unstable_opts.query_dep_graph
             || self.opts.unstable_opts.dump_mir.is_some()
             || self.opts.unstable_opts.unpretty.is_some()
+            || self.prof.is_args_recording_enabled()
             || self.opts.output_types.contains_key(&OutputType::Mir)
             || std::env::var_os("RUSTC_LOG").is_some()
         {

compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_musl.rs

@@ -6,7 +6,7 @@ pub(crate) fn target() -> Target {
     let mut base = base::linux_musl::opts();
     base.max_atomic_width = Some(128);
     base.supports_xray = true;
-    base.features = "+v8a".into();
+    base.features = "+v8a,+outline-atomics".into();
     base.stack_probes = StackProbeType::Inline;
     base.supported_sanitizers = SanitizerSet::ADDRESS
         | SanitizerSet::CFI

compiler/rustc_ty_utils/src/ty.rs

@@ -80,8 +80,11 @@ fn sizedness_constraint_for_ty<'tcx>(
 
 fn defaultness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Defaultness {
     match tcx.hir_node_by_def_id(def_id) {
-        hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(impl_), .. }) => impl_.defaultness,
-        hir::Node::ImplItem(hir::ImplItem { defaultness, .. })
+        hir::Node::Item(hir::Item {
+            kind: hir::ItemKind::Impl(hir::Impl { defaultness, of_trait: Some(_), .. }),
+            ..
+        })
+        | hir::Node::ImplItem(hir::ImplItem { defaultness, .. })
         | hir::Node::TraitItem(hir::TraitItem { defaultness, .. }) => *defaultness,
         node => {
             bug!("`defaultness` called on {:?}", node);

compiler/rustc_type_ir/src/relate.rs

@@ -400,8 +400,12 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
         (ty::Placeholder(p1), ty::Placeholder(p2)) if p1 == p2 => Ok(a),
 
         (ty::Adt(a_def, a_args), ty::Adt(b_def, b_args)) if a_def == b_def => {
-            let args = relation.relate_item_args(a_def.def_id(), a_args, b_args)?;
-            Ok(Ty::new_adt(cx, a_def, args))
+            Ok(if a_args.is_empty() {
+                a
+            } else {
+                let args = relation.relate_item_args(a_def.def_id(), a_args, b_args)?;
+                if args == a_args { a } else { Ty::new_adt(cx, a_def, args) }
+            })
         }
 
         (ty::Foreign(a_id), ty::Foreign(b_id)) if a_id == b_id => Ok(Ty::new_foreign(cx, a_id)),
@@ -515,8 +519,12 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
         }
 
         (ty::FnDef(a_def_id, a_args), ty::FnDef(b_def_id, b_args)) if a_def_id == b_def_id => {
-            let args = relation.relate_item_args(a_def_id, a_args, b_args)?;
-            Ok(Ty::new_fn_def(cx, a_def_id, args))
+            Ok(if a_args.is_empty() {
+                a
+            } else {
+                let args = relation.relate_item_args(a_def_id, a_args, b_args)?;
+                if args == a_args { a } else { Ty::new_fn_def(cx, a_def_id, args) }
+            })
         }
 
         (ty::FnPtr(a_sig_tys, a_hdr), ty::FnPtr(b_sig_tys, b_hdr)) => {

library/Cargo.lock

@@ -78,9 +78,9 @@ dependencies = [
 
 [[package]]
 name = "dlmalloc"
-version = "0.2.9"
+version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d01597dde41c0b9da50d5f8c219023d63d8f27f39a27095070fd191fddc83891"
+checksum = "fa3a2dbee57b69fbb5dbe852fa9c0925697fb0c7fbcb1593e90e5ffaedf13d51"
 dependencies = [
  "cfg-if",
  "libc",
@@ -90,11 +90,10 @@ dependencies = [
 
 [[package]]
 name = "fortanix-sgx-abi"
-version = "0.5.0"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57cafc2274c10fab234f176b25903ce17e690fca7597090d50880e047a0389c5"
+checksum = "5efc85edd5b83e8394f4371dd0da6859dff63dd387dab8568fece6af4cde6f84"
 dependencies = [
- "compiler_builtins",
  "rustc-std-workspace-core",
 ]
 

library/core/src/macros/mod.rs

@@ -426,8 +426,10 @@ pub macro debug_assert_matches($($arg:tt)*) {
 #[macro_export]
 #[stable(feature = "matches_macro", since = "1.42.0")]
 #[rustc_diagnostic_item = "matches_macro"]
+#[allow_internal_unstable(non_exhaustive_omitted_patterns_lint, stmt_expr_attributes)]
 macro_rules! matches {
     ($expression:expr, $pattern:pat $(if $guard:expr)? $(,)?) => {
+        #[allow(non_exhaustive_omitted_patterns)]
         match $expression {
             $pattern $(if $guard)? => true,
             _ => false

library/coretests/tests/lib.rs

@@ -76,6 +76,7 @@
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(next_index)]
+#![feature(non_exhaustive_omitted_patterns_lint)]
 #![feature(numfmt)]
 #![feature(pattern)]
 #![feature(pointer_is_aligned_to)]

library/coretests/tests/macros.rs

@@ -213,3 +213,9 @@ fn _expression() {
         }
     );
 }
+
+#[deny(non_exhaustive_omitted_patterns)]
+fn _matches_does_not_trigger_non_exhaustive_omitted_patterns_lint(o: core::sync::atomic::Ordering) {
+    // Ordering is a #[non_exhaustive] enum from a separate crate
+    let _m = matches!(o, core::sync::atomic::Ordering::Relaxed);
+}

library/std/Cargo.toml

@@ -63,10 +63,10 @@ rand = { version = "0.9.0", default-features = false, features = ["alloc"] }
 rand_xorshift = "0.4.0"
 
 [target.'cfg(any(all(target_family = "wasm", target_os = "unknown"), target_os = "xous", all(target_vendor = "fortanix", target_env = "sgx")))'.dependencies]
-dlmalloc = { version = "0.2.4", features = ['rustc-dep-of-std'] }
+dlmalloc = { version = "0.2.10", features = ['rustc-dep-of-std'] }
 
 [target.x86_64-fortanix-unknown-sgx.dependencies]
-fortanix-sgx-abi = { version = "0.5.0", features = [
+fortanix-sgx-abi = { version = "0.6.1", features = [
     'rustc-dep-of-std',
 ], public = true }
 

library/std/src/env.rs

@@ -617,7 +617,7 @@ impl Error for JoinPathsError {
 /// # Unix
 ///
 /// - Returns the value of the 'HOME' environment variable if it is set
-///   (including to an empty string).
+///   (and not an empty string).
 /// - Otherwise, it tries to determine the home directory by invoking the `getpwuid_r` function
 ///   using the UID of the current user. An empty home directory field returned from the
 ///   `getpwuid_r` function is considered to be a valid value.

library/std/src/sys/pal/sgx/abi/usercalls/mod.rs

@@ -267,7 +267,7 @@ pub fn send(event_set: u64, tcs: Option<Tcs>) -> IoResult<()> {
 /// Usercall `insecure_time`. See the ABI documentation for more information.
 #[unstable(feature = "sgx_platform", issue = "56975")]
 pub fn insecure_time() -> Duration {
-    let t = unsafe { raw::insecure_time() };
+    let t = unsafe { raw::insecure_time().0 };
     Duration::new(t / 1_000_000_000, (t % 1_000_000_000) as _)
 }
 

library/std/src/sys/pal/unix/os.rs

@@ -633,7 +633,10 @@ pub fn temp_dir() -> PathBuf {
 }
 
 pub fn home_dir() -> Option<PathBuf> {
-    return crate::env::var_os("HOME").or_else(|| unsafe { fallback() }).map(PathBuf::from);
+    return crate::env::var_os("HOME")
+        .filter(|s| !s.is_empty())
+        .or_else(|| unsafe { fallback() })
+        .map(PathBuf::from);
 
     #[cfg(any(
         target_os = "android",

library/std/src/thread/mod.rs

@@ -1399,6 +1399,11 @@ where
 }
 
 /// The internal representation of a `Thread` handle
+///
+/// We explicitly set the alignment for our guarantee in Thread::into_raw. This
+/// allows applications to stuff extra metadata bits into the alignment, which
+/// can be rather useful when working with atomics.
+#[repr(align(8))]
 struct Inner {
     name: Option<ThreadNameString>,
     id: ThreadId,
@@ -1582,7 +1587,8 @@ impl Thread {
     /// Consumes the `Thread`, returning a raw pointer.
     ///
     /// To avoid a memory leak the pointer must be converted
-    /// back into a `Thread` using [`Thread::from_raw`].
+    /// back into a `Thread` using [`Thread::from_raw`]. The pointer is
+    /// guaranteed to be aligned to at least 8 bytes.
     ///
     /// # Examples
     ///

library/stdarch/crates/core_arch/src/wasm32/mod.rs

@@ -191,6 +191,16 @@ unsafe extern "C-unwind" {
 // #[cfg_attr(test, assert_instr(throw, TAG = 0, ptr = core::ptr::null_mut()))]
 #[inline]
 #[unstable(feature = "wasm_exception_handling_intrinsics", issue = "122465")]
+// FIXME: Since this instruction unwinds, `core` built with `-C panic=unwind`
+//        cannot be linked with `-C panic=abort` programs. But that's not
+//        entirely supported anyway, because runtimes without EH support won't
+//        be able to handle `try` blocks in `-C panic=unwind` crates either.
+//        We ship `-C panic=abort` `core`, so this doesn't affect users
+//        directly. Resolving this will likely require patching out both `try`
+//        and `throw` instructions, at which point we can look into whitelisting
+//        this function in the compiler to allow linking.
+//        See https://github.com/rust-lang/rust/issues/118168.
+#[allow(ffi_unwind_calls)]
 pub unsafe fn throw<const TAG: i32>(ptr: *mut u8) -> ! {
     static_assert!(TAG == 0); // LLVM only supports tag 0 == C++ right now.
     wasm_throw(TAG, ptr)

library/windows_targets/src/lib.rs

@@ -34,22 +34,12 @@ pub macro link_dylib {
 
 #[cfg(feature = "windows_raw_dylib")]
 pub macro link($($tt:tt)*) {
-    $crate::link_raw_dylib!($($tt)*)
+    $crate::link_raw_dylib!($($tt)*);
 }
 
 #[cfg(not(feature = "windows_raw_dylib"))]
-pub macro link {
-    ($library:literal $abi:literal $($link_name:literal)? $(#[$doc:meta])? fn $($function:tt)*) => (
-        // Note: the windows-targets crate uses a pre-built Windows.lib import library which we don't
-        // have in this repo. So instead we always link kernel32.lib and add the rest of the import
-        // libraries below by using an empty extern block. This works because extern blocks are not
-        // connected to the library given in the #[link] attribute.
-        #[link(name = "kernel32")]
-        unsafe extern $abi {
-            $(#[link_name=$link_name])?
-            pub fn $($function)*;
-        }
-    )
+pub macro link($($tt:tt)*) {
+    $crate::link_dylib!($($tt)*);
 }
 
 #[cfg(not(feature = "windows_raw_dylib"))]

src/bootstrap/src/core/build_steps/clippy.rs

@@ -19,6 +19,7 @@ const IGNORED_RULES_FOR_STD_AND_RUSTC: &[&str] = &[
     "too_many_arguments",
     "needless_lifetimes", // people want to keep the lifetimes
     "wrong_self_convention",
+    "approx_constant", // libcore is what defines those
 ];
 
 fn lint_args(builder: &Builder<'_>, config: &LintConfig, ignored_rules: &[&str]) -> Vec<String> {

src/bootstrap/src/core/build_steps/compile.rs

@@ -597,11 +597,6 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
 
     let mut features = String::new();
 
-    if stage != 0 && builder.config.default_codegen_backend(target).as_deref() == Some("cranelift")
-    {
-        features += "compiler-builtins-no-f16-f128 ";
-    }
-
     if builder.no_std(target) == Some(true) {
         features += " compiler-builtins-mem";
         if !target.starts_with("bpf") {

src/bootstrap/src/core/build_steps/test.rs

@@ -3132,7 +3132,11 @@ impl Step for Bootstrap {
     }
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/bootstrap")
+        // Bootstrap tests might not be perfectly self-contained and can depend on the external
+        // environment, submodules that are checked out, etc.
+        // Therefore we only run them by default on CI.
+        let runs_on_ci = run.builder.config.is_running_on_ci;
+        run.path("src/bootstrap").default_condition(runs_on_ci)
     }
 
     fn make_run(run: RunConfig<'_>) {

src/bootstrap/src/core/sanity.rs

@@ -338,12 +338,6 @@ than building it.
 
         // Make sure musl-root is valid.
         if target.contains("musl") && !target.contains("unikraft") {
-            // If this is a native target (host is also musl) and no musl-root is given,
-            // fall back to the system toolchain in /usr before giving up
-            if build.musl_root(*target).is_none() && build.config.is_host_target(*target) {
-                let target = build.config.target_config.entry(*target).or_default();
-                target.musl_root = Some("/usr".into());
-            }
             match build.musl_libdir(*target) {
                 Some(libdir) => {
                     if fs::metadata(libdir.join("libc.a")).is_err() {

src/bootstrap/src/lib.rs

@@ -1329,23 +1329,33 @@ impl Build {
         }
     }
 
-    /// Returns the "musl root" for this `target`, if defined
+    /// Returns the "musl root" for this `target`, if defined.
+    ///
+    /// If this is a native target (host is also musl) and no musl-root is given,
+    /// it falls back to the system toolchain in /usr.
     fn musl_root(&self, target: TargetSelection) -> Option<&Path> {
-        self.config
+        let configured_root = self
+            .config
             .target_config
             .get(&target)
             .and_then(|t| t.musl_root.as_ref())
             .or(self.config.musl_root.as_ref())
-            .map(|p| &**p)
+            .map(|p| &**p);
+
+        if self.config.is_host_target(target) && configured_root.is_none() {
+            Some(Path::new("/usr"))
+        } else {
+            configured_root
+        }
     }
 
     /// Returns the "musl libdir" for this `target`.
     fn musl_libdir(&self, target: TargetSelection) -> Option<PathBuf> {
-        let t = self.config.target_config.get(&target)?;
-        if let libdir @ Some(_) = &t.musl_libdir {
-            return libdir.clone();
-        }
-        self.musl_root(target).map(|root| root.join("lib"))
+        self.config
+            .target_config
+            .get(&target)
+            .and_then(|t| t.musl_libdir.clone())
+            .or_else(|| self.musl_root(target).map(|root| root.join("lib")))
     }
 
     /// Returns the `lib` directory for the WASI target specified, if

src/bootstrap/src/utils/change_tracker.rs

@@ -439,7 +439,7 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
     ChangeInfo {
         change_id: 143255,
         severity: ChangeSeverity::Warning,
-        summary: "`llvm.lld` is no longer enabled by default for the dist profile.",
+        summary: "`rust.lld` is no longer enabled by default for the dist profile.",
     },
     ChangeInfo {
         change_id: 143251,

src/bootstrap/src/utils/shared_helpers.rs

@@ -1,14 +1,18 @@
 //! This module serves two purposes:
-//!     1. It is part of the `utils` module and used in other parts of bootstrap.
-//!     2. It is embedded inside bootstrap shims to avoid a dependency on the bootstrap library.
-//!        Therefore, this module should never use any other bootstrap module. This reduces binary
-//!        size and improves compilation time by minimizing linking time.
+//!
+//! 1. It is part of the `utils` module and used in other parts of bootstrap.
+//! 2. It is embedded inside bootstrap shims to avoid a dependency on the bootstrap library.
+//!    Therefore, this module should never use any other bootstrap module. This reduces binary size
+//!    and improves compilation time by minimizing linking time.
+
+// # Note on tests
+//
+// If we were to declare a tests submodule here, the shim binaries that include this module via
+// `#[path]` would fail to find it, which breaks `./x check bootstrap`. So instead the unit tests
+// for this module are in `super::tests::shared_helpers_tests`.
 
 #![allow(dead_code)]
 
-#[cfg(test)]
-mod tests;
-
 use std::env;
 use std::ffi::OsString;
 use std::fs::OpenOptions;
@@ -16,10 +20,6 @@ use std::io::Write;
 use std::process::Command;
 use std::str::FromStr;
 
-// If we were to declare a tests submodule here, the shim binaries that include this
-// module via `#[path]` would fail to find it, which breaks `./x check bootstrap`.
-// So instead the unit tests for this module are in `super::tests::shared_helpers_tests`.
-
 /// Returns the environment variable which the dynamic library lookup path
 /// resides in for this platform.
 pub fn dylib_path_var() -> &'static str {

src/bootstrap/src/utils/tests/mod.rs

@@ -12,6 +12,10 @@ use crate::{Build, Config, Flags, t};
 
 pub mod git;
 
+// Note: tests for `shared_helpers` is separate here, as otherwise shim binaries that include the
+// `shared_helpers` via `#[path]` would fail to find it, breaking `./x check bootstrap`.
+mod shared_helpers_tests;
+
 /// Holds temporary state of a bootstrap test.
 /// Right now it is only used to redirect the build directory of the bootstrap
 /// invocation, in the future it would be great if we could actually execute

src/bootstrap/src/utils/tests/shared_helpers_tests.rs

@@ -1,3 +1,10 @@
+//! The `shared_helpers` module can't have its own tests submodule, because that would cause
+//! problems for the shim binaries that include it via `#[path]`, so instead those unit tests live
+//! here.
+//!
+//! To prevent tidy from complaining about this file not being named `tests.rs`, it lives inside a
+//! submodule directory named `tests`.
+
 use crate::utils::shared_helpers::parse_value_from_args;
 
 #[test]

src/ci/docker/host-x86_64/pr-check-1/Dockerfile

@@ -40,6 +40,7 @@ COPY host-x86_64/pr-check-1/validate-toolstate.sh /scripts/
 # We disable optimized compiler built-ins because that requires a C toolchain for the target.
 # We also skip the x86_64-unknown-linux-gnu target as it is well-tested by other jobs.
 ENV SCRIPT \
+  python3 ../x.py check bootstrap && \
   /scripts/check-default-config-profiles.sh && \
   python3 ../x.py build src/tools/build-manifest && \
   python3 ../x.py test --stage 0 src/tools/compiletest && \

src/ci/docker/host-x86_64/test-various/Dockerfile

@@ -79,7 +79,6 @@ ENV MUSL_TARGETS=x86_64-unknown-linux-musl \
     CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++
 ENV MUSL_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $MUSL_TARGETS
 
-COPY host-x86_64/test-various/uefi_qemu_test /uefi_qemu_test
 ENV UEFI_TARGETS=aarch64-unknown-uefi,i686-unknown-uefi,x86_64-unknown-uefi \
     CC_aarch64_unknown_uefi=clang-11 \
     CXX_aarch64_unknown_uefi=clang++-11 \
@@ -88,6 +87,8 @@ ENV UEFI_TARGETS=aarch64-unknown-uefi,i686-unknown-uefi,x86_64-unknown-uefi \
     CC_x86_64_unknown_uefi=clang-11 \
     CXX_x86_64_unknown_uefi=clang++-11
 ENV UEFI_SCRIPT python3 /checkout/x.py --stage 2 build --host='' --target $UEFI_TARGETS && \
-  python3 -u /uefi_qemu_test/run.py
+  python3 /checkout/x.py --stage 2 test tests/run-make/uefi-qemu/rmake.rs --target aarch64-unknown-uefi && \
+  python3 /checkout/x.py --stage 2 test tests/run-make/uefi-qemu/rmake.rs --target i686-unknown-uefi && \
+  python3 /checkout/x.py --stage 2 test tests/run-make/uefi-qemu/rmake.rs --target x86_64-unknown-uefi
 
 ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT

src/ci/docker/host-x86_64/test-various/uefi_qemu_test/run.py

@@ -1,140 +0,0 @@
-#!/usr/bin/env python3
-
-import os
-import shutil
-import subprocess
-import sys
-import tempfile
-
-from pathlib import Path
-
-TARGET_AARCH64 = "aarch64-unknown-uefi"
-TARGET_I686 = "i686-unknown-uefi"
-TARGET_X86_64 = "x86_64-unknown-uefi"
-
-
-def run(*cmd, capture=False, check=True, env=None, timeout=None):
-    """Print and run a command, optionally capturing the output."""
-    cmd = [str(p) for p in cmd]
-    print(" ".join(cmd))
-    return subprocess.run(
-        cmd, capture_output=capture, check=check, env=env, text=True, timeout=timeout
-    )
-
-
-def build_and_run(tmp_dir, target):
-    if target == TARGET_AARCH64:
-        boot_file_name = "bootaa64.efi"
-        ovmf_dir = Path("/usr/share/AAVMF")
-        ovmf_code = "AAVMF_CODE.fd"
-        ovmf_vars = "AAVMF_VARS.fd"
-        qemu = "qemu-system-aarch64"
-        machine = "virt"
-        cpu = "cortex-a72"
-    elif target == TARGET_I686:
-        boot_file_name = "bootia32.efi"
-        ovmf_dir = Path("/usr/share/OVMF")
-        ovmf_code = "OVMF32_CODE_4M.secboot.fd"
-        ovmf_vars = "OVMF32_VARS_4M.fd"
-        # The i686 target intentionally uses 64-bit qemu; the important
-        # difference is that the OVMF code provides a 32-bit environment.
-        qemu = "qemu-system-x86_64"
-        machine = "q35"
-        cpu = "qemu64"
-    elif target == TARGET_X86_64:
-        boot_file_name = "bootx64.efi"
-        ovmf_dir = Path("/usr/share/OVMF")
-        ovmf_code = "OVMF_CODE.fd"
-        ovmf_vars = "OVMF_VARS.fd"
-        qemu = "qemu-system-x86_64"
-        machine = "q35"
-        cpu = "qemu64"
-    else:
-        raise KeyError("invalid target")
-
-    host_artifacts = Path("/checkout/obj/build/x86_64-unknown-linux-gnu")
-    stage0 = host_artifacts / "stage0/bin"
-    stage2 = host_artifacts / "stage2/bin"
-
-    env = dict(os.environ)
-    env["PATH"] = "{}:{}:{}".format(stage2, stage0, env["PATH"])
-
-    # Copy the test create into `tmp_dir`.
-    test_crate = Path(tmp_dir) / "uefi_qemu_test"
-    shutil.copytree("/uefi_qemu_test", test_crate)
-
-    # Build the UEFI executable.
-    run(
-        "cargo",
-        "build",
-        "--manifest-path",
-        test_crate / "Cargo.toml",
-        "--target",
-        target,
-        env=env,
-    )
-
-    # Create a mock EFI System Partition in a subdirectory.
-    esp = test_crate / "esp"
-    boot = esp / "efi/boot"
-    os.makedirs(boot, exist_ok=True)
-
-    # Copy the executable into the ESP.
-    src_exe_path = test_crate / "target" / target / "debug/uefi_qemu_test.efi"
-    shutil.copy(src_exe_path, boot / boot_file_name)
-    print(src_exe_path, boot / boot_file_name)
-
-    # Select the appropriate EDK2 build.
-    ovmf_code = ovmf_dir / ovmf_code
-    ovmf_vars = ovmf_dir / ovmf_vars
-
-    # Make a writable copy of the vars file. aarch64 doesn't boot
-    # correctly with read-only vars.
-    ovmf_rw_vars = Path(tmp_dir) / "vars.fd"
-    shutil.copy(ovmf_vars, ovmf_rw_vars)
-
-    # Run the executable in QEMU and capture the output.
-    output = run(
-        qemu,
-        "-machine",
-        machine,
-        "-cpu",
-        cpu,
-        "-display",
-        "none",
-        "-serial",
-        "stdio",
-        "-drive",
-        f"if=pflash,format=raw,readonly=on,file={ovmf_code}",
-        "-drive",
-        f"if=pflash,format=raw,readonly=off,file={ovmf_rw_vars}",
-        "-drive",
-        f"format=raw,file=fat:rw:{esp}",
-        capture=True,
-        check=True,
-        # Set a timeout to kill the VM in case something goes wrong.
-        timeout=60,
-    ).stdout
-
-    if "Hello World!" in output:
-        print("VM produced expected output")
-    else:
-        print("unexpected VM output:")
-        print("---start---")
-        print(output)
-        print("---end---")
-        sys.exit(1)
-
-
-def main():
-    targets = [TARGET_AARCH64, TARGET_I686, TARGET_X86_64]
-
-    for target in targets:
-        # Create a temporary directory so that we have a writeable
-        # workspace.
-        with tempfile.TemporaryDirectory() as tmp_dir:
-            build_and_run(tmp_dir, target)
-
-
-if __name__ == "__main__":
-    main()

src/doc/rustc-dev-guide/rust-version

@@ -1 +1 @@
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+efd420c770bb179537c01063e98cb6990c439654