Auto merge of #139622 - matthiaskrgr:rollup-8ri1vid, r=matthiaskrgr

Rollup of 13 pull requests

Successful merges:

 - #138167 (Small code improvement in rustdoc hidden stripper)
 - #138605 (Clean up librustdoc::html::render to be better encapsulated)
 - #139423 (Suppress missing field error when autoderef bottoms out in infer)
 - #139449 (match ergonomics: replace `peel_off_references` with a recursive call)
 - #139507 (compiletest: Trim whitespace from environment variable names)
 - #139530 (Remove some dead or leftover code related to rustc-intrinsic abi removal)
 - #139560 (fix title of offset_of_enum feature)
 - #139563 (emit a better error message for using the macro incorrectly)
 - #139568 (Don't use empty trait names)
 - #139580 (Temporarily leave the review rotation)
 - #139589 (saethlin is back from vacation)
 - #139592 (rustdoc: Enable Markdown extensions when looking for doctests)
 - #139599 (Tracking issue template: fine-grained information on style update status)

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

.github/ISSUE_TEMPLATE/tracking_issue.md

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

compiler/rustc_builtin_macros/src/autodiff.rs

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

compiler/rustc_error_codes/src/error_codes/E0622.md

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

compiler/rustc_error_codes/src/lib.rs

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

compiler/rustc_hir_analysis/src/check/check.rs

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

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -1,9 +1,8 @@
 //! Type-checking for the `#[rustc_intrinsic]` intrinsics that the compiler exposes.
 
 use rustc_abi::ExternAbi;
-use rustc_errors::codes::*;
+use rustc_errors::DiagMessage;
-use rustc_errors::{DiagMessage, struct_span_code_err};
+use rustc_hir::{self as hir};
-use rustc_hir::{self as hir, Safety};
 use rustc_middle::bug;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -26,17 +25,10 @@ fn equate_intrinsic_type<'tcx>(
     sig: ty::PolyFnSig<'tcx>,
 ) {
     let (generics, span) = match tcx.hir_node_by_def_id(def_id) {
-        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { generics, .. }, .. })
+        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { generics, .. }, .. }) => {
-        | hir::Node::ForeignItem(hir::ForeignItem {
+            (tcx.generics_of(def_id), generics.span)
-            kind: hir::ForeignItemKind::Fn(_, _, generics),
-            ..
-        }) => (tcx.generics_of(def_id), generics.span),
-        _ => {
-            struct_span_code_err!(tcx.dcx(), span, E0622, "intrinsic must be a function")
-                .with_span_label(span, "expected a function")
-                .emit();
-            return;
         }
+        _ => tcx.dcx().span_bug(span, "intrinsic must be a function"),
     };
     let own_counts = generics.own_counts();
 
@@ -70,13 +62,7 @@ fn equate_intrinsic_type<'tcx>(
 }
 
 /// Returns the unsafety of the given intrinsic.
-pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hir::Safety {
+fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hir::Safety {
-    let has_safe_attr = if tcx.has_attr(intrinsic_id, sym::rustc_intrinsic) {
-        tcx.fn_sig(intrinsic_id).skip_binder().safety()
-    } else {
-        // Old-style intrinsics are never safe
-        Safety::Unsafe
-    };
     let is_in_list = match tcx.item_name(intrinsic_id.into()) {
         // When adding a new intrinsic to this list,
         // it's usually worth updating that intrinsic's documentation
@@ -148,7 +134,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
         _ => hir::Safety::Unsafe,
     };
 
-    if has_safe_attr != is_in_list {
+    if tcx.fn_sig(intrinsic_id).skip_binder().safety() != is_in_list {
         tcx.dcx().struct_span_err(
             tcx.def_span(intrinsic_id),
             DiagMessage::from(format!(
@@ -163,12 +149,11 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
 
 /// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
 /// and in `library/core/src/intrinsics.rs`.
-pub fn check_intrinsic_type(
+pub(crate) fn check_intrinsic_type(
     tcx: TyCtxt<'_>,
     intrinsic_id: LocalDefId,
     span: Span,
     intrinsic_name: Symbol,
-    abi: ExternAbi,
 ) {
     let generics = tcx.generics_of(intrinsic_id);
     let param = |n| {
@@ -706,7 +691,7 @@ pub fn check_intrinsic_type(
         };
         (n_tps, 0, n_cts, inputs, output, safety)
     };
-    let sig = tcx.mk_fn_sig(inputs, output, false, safety, abi);
+    let sig = tcx.mk_fn_sig(inputs, output, false, safety, ExternAbi::Rust);
     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
     equate_intrinsic_type(tcx, span, intrinsic_id, n_tps, n_lts, n_cts, sig)
 }

compiler/rustc_hir_typeck/src/expr.rs

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

compiler/rustc_hir_typeck/src/pat.rs

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

compiler/rustc_parse/src/parser/item.rs

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

compiler/rustc_resolve/src/ident.rs

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

src/doc/unstable-book/src/language-features/offset-of-enum.md

@@ -1,4 +1,4 @@
-# `offset_of_slice`
+# `offset_of_enum`
 
 The tracking issue for this feature is: [#120141]
 

src/librustdoc/html/markdown.rs

@@ -721,7 +721,7 @@ pub(crate) fn find_codes<T: doctest::DocTestVisitor>(
     extra_info: Option<&ExtraInfo<'_>>,
     include_non_rust: bool,
 ) {
-    let mut parser = Parser::new(doc).into_offset_iter();
+    let mut parser = Parser::new_ext(doc, main_body_opts()).into_offset_iter();
     let mut prev_offset = 0;
     let mut nb_lines = 0;
     let mut register_header = None;

src/librustdoc/html/render/mod.rs

@@ -13,6 +13,9 @@
 //! is cloned per-thread and contains information about what is currently being
 //! rendered.
 //!
+//! The main entry point to the rendering system is the implementation of
+//! `FormatRenderer` on `Context`.
+//!
 //! In order to speed up rendering (mostly because of markdown rendering), the
 //! rendering process has been parallelized. This parallelization is only
 //! exposed through the `crate` method on the context, and then also from the
@@ -90,7 +93,7 @@ pub(crate) fn ensure_trailing_slash(v: &str) -> impl fmt::Display {
 /// Specifies whether rendering directly implemented trait items or ones from a certain Deref
 /// impl.
 #[derive(Copy, Clone, Debug)]
-pub(crate) enum AssocItemRender<'a> {
+enum AssocItemRender<'a> {
     All,
     DerefFor { trait_: &'a clean::Path, type_: &'a clean::Type, deref_mut_: bool },
 }
@@ -98,7 +101,7 @@ pub(crate) enum AssocItemRender<'a> {
 /// For different handling of associated items from the Deref target of a type rather than the type
 /// itself.
 #[derive(Copy, Clone, PartialEq)]
-pub(crate) enum RenderMode {
+enum RenderMode {
     Normal,
     ForDeref { mut_: bool },
 }
@@ -126,7 +129,7 @@ pub(crate) struct IndexItem {
 
 /// A type used for the search index.
 #[derive(Debug, Eq, PartialEq)]
-pub(crate) struct RenderType {
+struct RenderType {
     id: Option<RenderTypeId>,
     generics: Option<Vec<RenderType>>,
     bindings: Option<Vec<(RenderTypeId, Vec<RenderType>)>>,
@@ -137,7 +140,7 @@ impl RenderType {
     // The contents of the lists are always integers in self-terminating hex
     // form, handled by `RenderTypeId::write_to_string`, so no commas are
     // needed to separate the items.
-    pub fn write_to_string(&self, string: &mut String) {
+    fn write_to_string(&self, string: &mut String) {
         fn write_optional_id(id: Option<RenderTypeId>, string: &mut String) {
             // 0 is a sentinel, everything else is one-indexed
             match id {
@@ -177,7 +180,7 @@ impl RenderType {
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
-pub(crate) enum RenderTypeId {
+enum RenderTypeId {
     DefId(DefId),
     Primitive(clean::PrimitiveType),
     AssociatedType(Symbol),
@@ -186,7 +189,7 @@ pub(crate) enum RenderTypeId {
 }
 
 impl RenderTypeId {
-    pub fn write_to_string(&self, string: &mut String) {
+    fn write_to_string(&self, string: &mut String) {
         let id: i32 = match &self {
             // 0 is a sentinel, everything else is one-indexed
             // concrete type
@@ -209,7 +212,7 @@ pub(crate) struct IndexItemFunctionType {
 }
 
 impl IndexItemFunctionType {
-    pub fn write_to_string<'a>(
+    fn write_to_string<'a>(
         &'a self,
         string: &mut String,
         backref_queue: &mut VecDeque<&'a IndexItemFunctionType>,
@@ -309,7 +312,7 @@ impl ItemEntry {
 }
 
 impl ItemEntry {
-    pub(crate) fn print(&self) -> impl fmt::Display {
+    fn print(&self) -> impl fmt::Display {
         fmt::from_fn(move |f| write!(f, "<a href=\"{}\">{}</a>", self.url, Escape(&self.name)))
     }
 }
@@ -760,7 +763,7 @@ fn short_item_info(
 
 // Render the list of items inside one of the sections "Trait Implementations",
 // "Auto Trait Implementations," "Blanket Trait Implementations" (on struct/enum pages).
-pub(crate) fn render_impls(
+fn render_impls(
     cx: &Context<'_>,
     mut w: impl Write,
     impls: &[&Impl],
@@ -1201,7 +1204,7 @@ impl<'a> AssocItemLink<'a> {
     }
 }
 
-pub fn write_section_heading(
+fn write_section_heading(
     title: &str,
     id: &str,
     extra_class: Option<&str>,
@@ -1226,7 +1229,7 @@ fn write_impl_section_heading(title: &str, id: &str) -> impl fmt::Display {
     write_section_heading(title, id, None, "")
 }
 
-pub(crate) fn render_all_impls(
+fn render_all_impls(
     mut w: impl Write,
     cx: &Context<'_>,
     containing_item: &clean::Item,
@@ -1473,10 +1476,7 @@ fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) ->
     }
 }
 
-pub(crate) fn notable_traits_button(
+fn notable_traits_button(ty: &clean::Type, cx: &Context<'_>) -> Option<impl fmt::Display> {
-    ty: &clean::Type,
-    cx: &Context<'_>,
-) -> Option<impl fmt::Display> {
     if ty.is_unit() {
         // Very common fast path.
         return None;
@@ -1588,10 +1588,7 @@ fn notable_traits_decl(ty: &clean::Type, cx: &Context<'_>) -> (String, String) {
     (format!("{:#}", ty.print(cx)), out)
 }
 
-pub(crate) fn notable_traits_json<'a>(
+fn notable_traits_json<'a>(tys: impl Iterator<Item = &'a clean::Type>, cx: &Context<'_>) -> String {
-    tys: impl Iterator<Item = &'a clean::Type>,
-    cx: &Context<'_>,
-) -> String {
     let mut mp: Vec<(String, String)> = tys.map(|ty| notable_traits_decl(ty, cx)).collect();
     mp.sort_by(|(name1, _html1), (name2, _html2)| name1.cmp(name2));
     struct NotableTraitsMap(Vec<(String, String)>);
@@ -2171,7 +2168,7 @@ fn render_rightside(
     })
 }
 
-pub(crate) fn render_impl_summary(
+fn render_impl_summary(
     cx: &Context<'_>,
     i: &Impl,
     parent: &clean::Item,

src/librustdoc/passes/strip_hidden.rs

@@ -91,19 +91,21 @@ impl DocFolder for Stripper<'_, '_> {
 
         if let clean::ImportItem(clean::Import { source, .. }) = &i.kind
             && let Some(source_did) = source.did
-            && let Some(import_def_id) = i.def_id().and_then(|def_id| def_id.as_local())
         {
-            let reexports = reexport_chain(self.tcx, import_def_id, source_did);
+            if self.tcx.is_doc_hidden(source_did) {
-
-            // Check if any reexport in the chain has a hidden source
-            let has_hidden_source = reexports
-                .iter()
-                .filter_map(|reexport| reexport.id())
-                .any(|reexport_did| self.tcx.is_doc_hidden(reexport_did))
-                || self.tcx.is_doc_hidden(source_did);
-
-            if has_hidden_source {
                 return None;
+            } else if let Some(import_def_id) = i.def_id().and_then(|def_id| def_id.as_local()) {
+                let reexports = reexport_chain(self.tcx, import_def_id, source_did);
+
+                // Check if any reexport in the chain has a hidden source
+                let has_hidden_source = reexports
+                    .iter()
+                    .filter_map(|reexport| reexport.id())
+                    .any(|reexport_did| self.tcx.is_doc_hidden(reexport_did));
+
+                if has_hidden_source {
+                    return None;
+                }
             }
         }
 

src/tools/compiletest/src/header.rs

@@ -452,7 +452,7 @@ impl TestProps {
                         ln,
                         UNSET_EXEC_ENV,
                         &mut self.unset_exec_env,
-                        |r| r,
+                        |r| r.trim().to_owned(),
                     );
                     config.push_name_value_directive(
                         ln,
@@ -464,7 +464,7 @@ impl TestProps {
                         ln,
                         UNSET_RUSTC_ENV,
                         &mut self.unset_rustc_env,
-                        |r| r,
+                        |r| r.trim().to_owned(),
                     );
                     config.push_name_value_directive(
                         ln,
@@ -997,16 +997,13 @@ impl Config {
 
     fn parse_env(nv: String) -> (String, String) {
         // nv is either FOO or FOO=BAR
-        let mut strs: Vec<String> = nv.splitn(2, '=').map(str::to_owned).collect();
+        // FIXME(Zalathar): The form without `=` seems to be unused; should
-
+        // we drop support for it?
-        match strs.len() {
+        let (name, value) = nv.split_once('=').unwrap_or((&nv, ""));
-            1 => (strs.pop().unwrap(), String::new()),
+        // Trim whitespace from the name, so that `//@ exec-env: FOO=BAR`
-            2 => {
+        // sees the name as `FOO` and not ` FOO`.
-                let end = strs.pop().unwrap();
+        let name = name.trim();
-                (strs.pop().unwrap(), end)
+        (name.to_owned(), value.to_owned())
-            }
-            n => panic!("Expected 1 or 2 strings, not {}", n),
-        }
     }
 
     fn parse_pp_exact(&self, line: &str, testfile: &Path) -> Option<PathBuf> {

src/tools/compiletest/src/runtest.rs

@@ -968,16 +968,16 @@ impl<'test> TestCx<'test> {
         delete_after_success: bool,
     ) -> ProcRes {
         let prepare_env = |cmd: &mut Command| {
-            for key in &self.props.unset_exec_env {
-                cmd.env_remove(key);
-            }
-
             for (key, val) in &self.props.exec_env {
                 cmd.env(key, val);
             }
             for (key, val) in env_extra {
                 cmd.env(key, val);
             }
+
+            for key in &self.props.unset_exec_env {
+                cmd.env_remove(key);
+            }
         };
 
         let proc_res = match &*self.config.target {

tests/rustdoc-ui/multi-par-footnote.rs

@@ -0,0 +1,18 @@
+//@ check-pass
+//@ compile-flags:--test
+//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
+// Regression test for #139064.
+
+/// Example
+///
+/// Footnote with multiple paragraphs[^multiple]
+///
+/// [^multiple]:
+///     One
+///
+///     Two
+///
+///     Three
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}

tests/rustdoc-ui/multi-par-footnote.stdout

@@ -0,0 +1,5 @@
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+

tests/ui/autodiff/autodiff_illegal.rs

@@ -63,7 +63,7 @@ fn dummy() {
 // Malformed, where args?
 #[autodiff]
 pub fn f7(x: f64) {
-    //~^ ERROR autodiff must be applied to function
+    //~^ ERROR autodiff requires at least a name and mode
     unimplemented!()
 }
 
@@ -77,7 +77,7 @@ pub fn f8(x: f64) {
 // Invalid attribute syntax
 #[autodiff = ""]
 pub fn f9(x: f64) {
-    //~^ ERROR autodiff must be applied to function
+    //~^ ERROR autodiff requires at least a name and mode
     unimplemented!()
 }
 

tests/ui/autodiff/autodiff_illegal.stderr

@@ -62,7 +62,7 @@ error: autodiff must be applied to function
 LL |     let add_one_v2 = |x: u32| -> u32 { x + 1 };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: autodiff must be applied to function
+error: autodiff requires at least a name and mode
   --> $DIR/autodiff_illegal.rs:65:1
    |
 LL | / pub fn f7(x: f64) {
@@ -80,7 +80,7 @@ LL | |     unimplemented!()
 LL | | }
    | |_^
 
-error: autodiff must be applied to function
+error: autodiff requires at least a name and mode
   --> $DIR/autodiff_illegal.rs:79:1
    |
 LL | / pub fn f9(x: f64) {

tests/ui/compiletest-self-test/trim-env-name.rs

@@ -0,0 +1,23 @@
+//@ edition: 2024
+//@ revisions: set unset
+//@ run-pass
+//@ ignore-cross-compile (assume that non-cross targets have working env vars)
+//@ rustc-env: MY_RUSTC_ENV =  my-rustc-value
+//@ exec-env:  MY_EXEC_ENV  =  my-exec-value
+//@[unset] unset-rustc-env:    MY_RUSTC_ENV
+//@[unset] unset-exec-env:     MY_EXEC_ENV
+
+// Check that compiletest trims whitespace from environment variable names
+// specified in `rustc-env` and `exec-env` directives, so that
+// `//@ exec-env: FOO=bar` sees the name as `FOO` and not ` FOO`.
+//
+// Values are currently not trimmed.
+//
+// Since this is a compiletest self-test, only run it on non-cross targets,
+// to avoid having to worry about weird targets that don't support env vars.
+
+fn main() {
+    let is_set = cfg!(set);
+    assert_eq!(option_env!("MY_RUSTC_ENV"), is_set.then_some("  my-rustc-value"));
+    assert_eq!(std::env::var("MY_EXEC_ENV").ok().as_deref(), is_set.then_some("  my-exec-value"));
+}

tests/ui/error-codes/E0622.rs

@@ -1,14 +0,0 @@
-#![feature(intrinsics)]
-
-extern "C" {
-
-    #[rustc_intrinsic]
-    pub static atomic_singlethreadfence_seqcst: unsafe extern "C" fn();
-    //~^ ERROR intrinsic must be a function [E0622]
-}
-
-fn main() {
-    unsafe {
-        atomic_singlethreadfence_seqcst();
-    }
-}

tests/ui/error-codes/E0622.stderr

@@ -1,9 +0,0 @@
-error[E0622]: intrinsic must be a function
-  --> $DIR/E0622.rs:6:5
-   |
-LL |     pub static atomic_singlethreadfence_seqcst: unsafe extern "C" fn();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected a function
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0622`.

tests/ui/parser/impl-parsing-2.rs

@@ -0,0 +1,4 @@
+impl ! {} // OK
+
+default unsafe FAIL //~ ERROR expected item, found keyword `unsafe`
+//~^ ERROR `default` is not followed by an item

tests/ui/parser/impl-parsing-2.stderr

@@ -0,0 +1,18 @@
+error: `default` is not followed by an item
+  --> $DIR/impl-parsing-2.rs:3:1
+   |
+LL | default unsafe FAIL
+   | ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
+
+error: expected item, found keyword `unsafe`
+  --> $DIR/impl-parsing-2.rs:3:9
+   |
+LL | default unsafe FAIL
+   |         ^^^^^^ expected item
+   |
+   = note: for a full list of items that can appear in modules, see <https://doc.rust-lang.org/reference/items.html>
+
+error: aborting due to 2 previous errors
+

tests/ui/parser/impl-parsing.rs

@@ -2,9 +2,4 @@ impl ! {} // OK
 impl ! where u8: Copy {} // OK
 
 impl Trait Type {} //~ ERROR missing `for` in a trait impl
-impl Trait .. {} //~ ERROR missing `for` in a trait impl
 impl ?Sized for Type {} //~ ERROR expected a trait, found type
-impl ?Sized for .. {} //~ ERROR expected a trait, found type
-
-default unsafe FAIL //~ ERROR expected item, found keyword `unsafe`
-//~^ ERROR `default` is not followed by an item

tests/ui/parser/impl-parsing.stderr

@@ -9,44 +9,11 @@ help: add `for` here
 LL | impl Trait for Type {}
    |            +++
 
-error: missing `for` in a trait impl
-  --> $DIR/impl-parsing.rs:5:11
-   |
-LL | impl Trait .. {}
-   |           ^
-   |
-help: add `for` here
-   |
-LL | impl Trait for .. {}
-   |            +++
-
 error: expected a trait, found type
-  --> $DIR/impl-parsing.rs:6:6
+  --> $DIR/impl-parsing.rs:5:6
    |
 LL | impl ?Sized for Type {}
    |      ^^^^^^
 
-error: expected a trait, found type
+error: aborting due to 2 previous errors
-  --> $DIR/impl-parsing.rs:7:6
-   |
-LL | impl ?Sized for .. {}
-   |      ^^^^^^
-
-error: `default` is not followed by an item
-  --> $DIR/impl-parsing.rs:9:1
-   |
-LL | default unsafe FAIL
-   | ^^^^^^^ the `default` qualifier
-   |
-   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
-
-error: expected item, found keyword `unsafe`
-  --> $DIR/impl-parsing.rs:9:9
-   |
-LL | default unsafe FAIL
-   |         ^^^^^^ expected item
-   |
-   = note: for a full list of items that can appear in modules, see <https://doc.rust-lang.org/reference/items.html>
-
-error: aborting due to 6 previous errors
 

tests/ui/typeck/issue-65611.rs

@@ -58,6 +58,5 @@ fn main() {
     let mut buffer = ArrayVec::new();
     let x = buffer.last().unwrap().0.clone();
     //~^ ERROR type annotations needed
-    //~| ERROR no field `0` on type `&_`
     buffer.reverse();
 }

tests/ui/typeck/issue-65611.stderr

@@ -4,13 +4,6 @@ error[E0282]: type annotations needed
 LL |     let x = buffer.last().unwrap().0.clone();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for type parameter `T`
 
-error[E0609]: no field `0` on type `&_`
+error: aborting due to 1 previous error
-  --> $DIR/issue-65611.rs:59:36
-   |
-LL |     let x = buffer.last().unwrap().0.clone();
-   |                                    ^ unknown field
 
-error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0282`.
-
-Some errors have detailed explanations: E0282, E0609.
-For more information about an error, try `rustc --explain E0282`.

triagebot.toml

@@ -1123,8 +1123,8 @@ cc = ["@ZuseZ4"]
 warn_non_default_branch.enable = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
 users_on_vacation = [
+    "fmease",
     "jyn514",
-    "saethlin",
     "Noratrieb",
 ]