Auto merge of #81304 - jonas-schievink:rollup-d9kuugm, r=jonas-schievink

Rollup of 15 pull requests

Successful merges:

 - #79841 (More clear documentation for NonNull<T>)
 - #81072 (PlaceRef::ty: use method call syntax)
 - #81130 (Edit rustc_middle::dep_graph module documentation)
 - #81170 (Avoid hash_slice in VecDeque's Hash implementation)
 - #81243 (mir: Improve size_of handling when arg is unsized)
 - #81245 (Update cargo)
 - #81249 (Lower closure prototype after its body.)
 - #81252 (Add more self-profile info to rustc_resolve)
 - #81275 (Fix <unknown> queries and add more timing info to render_html)
 - #81281 (Inline methods of Path and OsString)
 - #81283 (Note library tracking issue template in tracking issue template.)
 - #81285 (Remove special casing of rustdoc in rustc_lint)
 - #81288 (rustdoc: Fix visibility of trait and impl items)
 - #81298 (replace RefCell with Cell in FnCtxt)
 - #81301 (Fix small typo)

Failed merges:

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

.github/ISSUE_TEMPLATE/tracking_issue.md

@@ -5,6 +5,8 @@ title: Tracking Issue for XXX
 labels: C-tracking-issue
 ---
 <!--
+NOTE: For library features, please use the "Library Tracking Issue" template instead.
+
 Thank you for creating a tracking issue! 📜 Tracking issues are for tracking a
 feature from implementation to stabilisation. Make sure to include the relevant
 RFC for the feature if it has one. Otherwise provide a short summary of the

Cargo.lock

@@ -427,6 +427,7 @@ dependencies = [
  "remove_dir_all",
  "serde_json",
  "tar",
+ "toml",
  "url 2.1.1",
 ]
 

compiler/rustc_ast_lowering/src/expr.rs

@@ -776,10 +776,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         body: &Expr,
         fn_decl_span: Span,
     ) -> hir::ExprKind<'hir> {
-        // Lower outside new scope to preserve `is_in_loop_condition`.
+        let (body_id, generator_option) = self.with_new_scopes(move |this| {
-        let fn_decl = self.lower_fn_decl(decl, None, false, None);
-
-        self.with_new_scopes(move |this| {
             let prev = this.current_item;
             this.current_item = Some(fn_decl_span);
             let mut generator_kind = None;
@@ -791,8 +788,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let generator_option =
                 this.generator_movability_for_fn(&decl, fn_decl_span, generator_kind, movability);
             this.current_item = prev;
-            hir::ExprKind::Closure(capture_clause, fn_decl, body_id, fn_decl_span, generator_option)
+            (body_id, generator_option)
-        })
+        });
+
+        // Lower outside new scope to preserve `is_in_loop_condition`.
+        let fn_decl = self.lower_fn_decl(decl, None, false, None);
+
+        hir::ExprKind::Closure(capture_clause, fn_decl, body_id, fn_decl_span, generator_option)
     }
 
     fn generator_movability_for_fn(
@@ -838,12 +840,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ) -> hir::ExprKind<'hir> {
         let outer_decl =
             FnDecl { inputs: decl.inputs.clone(), output: FnRetTy::Default(fn_decl_span) };
-        // We need to lower the declaration outside the new scope, because we
-        // have to conserve the state of being inside a loop condition for the
-        // closure argument types.
-        let fn_decl = self.lower_fn_decl(&outer_decl, None, false, None);
 
-        self.with_new_scopes(move |this| {
+        let body_id = self.with_new_scopes(|this| {
             // FIXME(cramertj): allow `async` non-`move` closures with arguments.
             if capture_clause == CaptureBy::Ref && !decl.inputs.is_empty() {
                 struct_span_err!(
@@ -874,8 +872,15 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 );
                 this.expr(fn_decl_span, async_body, ThinVec::new())
             });
-            hir::ExprKind::Closure(capture_clause, fn_decl, body_id, fn_decl_span, None)
+            body_id
-        })
+        });
+
+        // We need to lower the declaration outside the new scope, because we
+        // have to conserve the state of being inside a loop condition for the
+        // closure argument types.
+        let fn_decl = self.lower_fn_decl(&outer_decl, None, false, None);
+
+        hir::ExprKind::Closure(capture_clause, fn_decl, body_id, fn_decl_span, None)
     }
 
     /// Destructure the LHS of complex assignments.

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -119,7 +119,7 @@ impl<Bx: BuilderMethods<'a, 'tcx>> LocalAnalyzer<'mir, 'a, 'tcx, Bx> {
                 )
             );
             if is_consume {
-                let base_ty = mir::PlaceRef::ty(&place_base, self.fx.mir, cx.tcx());
+                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.

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -506,7 +506,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
     pub fn monomorphized_place_ty(&self, place_ref: mir::PlaceRef<'tcx>) -> Ty<'tcx> {
         let tcx = self.cx.tcx();
-        let place_ty = mir::PlaceRef::ty(&place_ref, self.mir, tcx);
+        let place_ty = place_ref.ty(self.mir, tcx);
         self.monomorphize(place_ty.ty)
     }
 }

compiler/rustc_interface/src/passes.rs

@@ -1017,13 +1017,6 @@ pub fn start_codegen<'tcx>(
     tcx.sess.time("assert_dep_graph", || rustc_incremental::assert_dep_graph(tcx));
     tcx.sess.time("serialize_dep_graph", || rustc_incremental::save_dep_graph(tcx));
 
-    // We assume that no queries are run past here. If there are new queries
-    // after this point, they'll show up as "<unknown>" in self-profiling data.
-    {
-        let _prof_timer = tcx.prof.generic_activity("self_profile_alloc_query_strings");
-        tcx.alloc_self_profile_query_strings();
-    }
-
     info!("Post-codegen\n{:?}", tcx.debug_stats());
 
     if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {

compiler/rustc_interface/src/queries.rs

@@ -417,9 +417,19 @@ impl Compiler {
         let queries = Queries::new(&self);
         let ret = f(&queries);
 
-        if self.session().opts.debugging_opts.query_stats {
+        // NOTE: intentionally does not compute the global context if it hasn't been built yet,
-            if let Ok(gcx) = queries.global_ctxt() {
+        // since that likely means there was a parse error.
-                gcx.peek_mut().print_stats();
+        if let Some(Ok(gcx)) = &mut *queries.global_ctxt.result.borrow_mut() {
+            // We assume that no queries are run past here. If there are new queries
+            // after this point, they'll show up as "<unknown>" in self-profiling data.
+            {
+                let _prof_timer =
+                    queries.session().prof.generic_activity("self_profile_alloc_query_strings");
+                gcx.enter(|tcx| tcx.alloc_self_profile_query_strings());
+            }
+
+            if self.session().opts.debugging_opts.query_stats {
+                gcx.print_stats();
             }
         }
 

compiler/rustc_lint/src/early.rs

@@ -379,17 +379,9 @@ pub fn check_ast_crate<T: EarlyLintPass>(
     // All of the buffered lints should have been emitted at this point.
     // If not, that means that we somehow buffered a lint for a node id
     // that was not lint-checked (perhaps it doesn't exist?). This is a bug.
-    //
+    for (_id, lints) in buffered.map {
-    // Rustdoc runs everybody-loops before the early lints and removes
+        for early_lint in lints {
-    // function bodies, so it's totally possible for linted
+            sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
-    // node ids to not exist (e.g., macros defined within functions for the
-    // unused_macro lint) anymore. So we only run this check
-    // when we're not in rustdoc mode. (see issue #47639)
-    if !sess.opts.actually_rustdoc {
-        for (_id, lints) in buffered.map {
-            for early_lint in lints {
-                sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
-            }
         }
     }
 }

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -1,16 +1,17 @@
-//! This module defines the `DepNode` type which the compiler uses to represent
+//! Nodes in the dependency graph.
-//! nodes in the dependency graph.
 //!
-//! A `DepNode` consists of a `DepKind` (which
+//! A node in the [dependency graph] is represented by a [`DepNode`].
-//! specifies the kind of thing it represents, like a piece of HIR, MIR, etc)
+//! A `DepNode` consists of a [`DepKind`] (which
-//! and a `Fingerprint`, a 128-bit hash value the exact meaning of which
+//! specifies the kind of thing it represents, like a piece of HIR, MIR, etc.)
+//! and a [`Fingerprint`], a 128-bit hash value, the exact meaning of which
 //! depends on the node's `DepKind`. Together, the kind and the fingerprint
 //! fully identify a dependency node, even across multiple compilation sessions.
 //! In other words, the value of the fingerprint does not depend on anything
 //! that is specific to a given compilation session, like an unpredictable
-//! interning key (e.g., NodeId, DefId, Symbol) or the numeric value of a
+//! interning key (e.g., `NodeId`, `DefId`, `Symbol`) or the numeric value of a
 //! pointer. The concept behind this could be compared to how git commit hashes
-//! uniquely identify a given commit and has a few advantages:
+//! uniquely identify a given commit. The fingerprinting approach has
+//! a few advantages:
 //!
 //! * A `DepNode` can simply be serialized to disk and loaded in another session
 //!   without the need to do any "rebasing" (like we have to do for Spans and
@@ -51,6 +52,8 @@
 //! than a zeroed out fingerprint. More generally speaking, it relieves the
 //! user of the `DepNode` API of having to know how to compute the expected
 //! fingerprint for a given set of node parameters.
+//!
+//! [dependency graph]: https://rustc-dev-guide.rust-lang.org/query.html
 
 use crate::ty::TyCtxt;
 

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

@@ -127,6 +127,8 @@ pub enum InvalidProgramInfo<'tcx> {
     Layout(layout::LayoutError<'tcx>),
     /// An invalid transmute happened.
     TransmuteSizeDiff(Ty<'tcx>, Ty<'tcx>),
+    /// SizeOf of unsized type was requested.
+    SizeOfUnsizedType(Ty<'tcx>),
 }
 
 impl fmt::Display for InvalidProgramInfo<'_> {
@@ -144,6 +146,7 @@ impl fmt::Display for InvalidProgramInfo<'_> {
                 "transmuting `{}` to `{}` is not possible, because these types do not have the same size",
                 from_ty, to_ty
             ),
+            SizeOfUnsizedType(ty) => write!(f, "size_of called on unsized type `{}`", ty),
         }
     }
 }

compiler/rustc_mir/src/borrow_check/diagnostics/conflict_errors.rs

@@ -289,7 +289,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 );
             }
 
-            let ty = PlaceRef::ty(&used_place, self.body, self.infcx.tcx).ty;
+            let ty = used_place.ty(self.body, self.infcx.tcx).ty;
             let needs_note = match ty.kind() {
                 ty::Closure(id, _) => {
                     let tables = self.infcx.tcx.typeck(id.expect_local());
@@ -728,6 +728,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         // Define a small closure that we can use to check if the type of a place
         // is a union.
         let union_ty = |place_base| {
+            // Need to use fn call syntax `PlaceRef::ty` to determine the type of `place_base`;
+            // using a type annotation in the closure argument instead leads to a lifetime error.
             let ty = PlaceRef::ty(&place_base, self.body, self.infcx.tcx).ty;
             ty.ty_adt_def().filter(|adt| adt.is_union()).map(|_| ty)
         };

compiler/rustc_mir/src/borrow_check/mod.rs

@@ -1743,7 +1743,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         if let Some((place_base, ProjectionElem::Subslice { from, to, from_end: false })) =
             place_span.0.last_projection()
         {
-            let place_ty = PlaceRef::ty(&place_base, self.body(), self.infcx.tcx);
+            let place_ty = place_base.ty(self.body(), self.infcx.tcx);
             if let ty::Array(..) = place_ty.ty.kind() {
                 self.check_if_subslice_element_is_moved(
                     location,
@@ -1854,7 +1854,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     // assigning to `P.f` requires `P` itself
                     // be already initialized
                     let tcx = self.infcx.tcx;
-                    let base_ty = PlaceRef::ty(&place_base, self.body(), tcx).ty;
+                    let base_ty = place_base.ty(self.body(), tcx).ty;
                     match base_ty.kind() {
                         ty::Adt(def, _) if def.has_dtor(tcx) => {
                             self.check_if_path_or_subpath_is_moved(
@@ -1951,7 +1951,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 // no move out from an earlier location) then this is an attempt at initialization
                 // of the union - we should error in that case.
                 let tcx = this.infcx.tcx;
-                if let ty::Adt(def, _) = PlaceRef::ty(&base, this.body(), tcx).ty.kind() {
+                if let ty::Adt(def, _) = base.ty(this.body(), tcx).ty.kind() {
                     if def.is_union() {
                         if this.move_data.path_map[mpi].iter().any(|moi| {
                             this.move_data.moves[*moi].source.is_predecessor_of(location, this.body)
@@ -2173,7 +2173,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             Some((place_base, elem)) => {
                 match elem {
                     ProjectionElem::Deref => {
-                        let base_ty = PlaceRef::ty(&place_base, self.body(), self.infcx.tcx).ty;
+                        let base_ty = place_base.ty(self.body(), self.infcx.tcx).ty;
 
                         // Check the kind of deref to decide
                         match base_ty.kind() {

compiler/rustc_mir/src/borrow_check/prefixes.rs

@@ -117,7 +117,7 @@ impl<'cx, 'tcx> Iterator for Prefixes<'cx, 'tcx> {
                     // derefs, except we stop at the deref of a shared
                     // reference.
 
-                    let ty = PlaceRef::ty(&cursor_base, self.body, self.tcx).ty;
+                    let ty = cursor_base.ty(self.body, self.tcx).ty;
                     match ty.kind() {
                         ty::RawPtr(_) | ty::Ref(_ /*rgn*/, _ /*ty*/, hir::Mutability::Not) => {
                             // don't continue traversing over derefs of raw pointers or shared

compiler/rustc_mir/src/interpret/step.rs

@@ -270,6 +270,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         self.frame().current_span(),
                         &format!("SizeOf nullary MIR operator called for unsized type {}", ty),
                     );
+                    throw_inval!(SizeOfUnsizedType(ty));
                 }
                 self.write_scalar(Scalar::from_machine_usize(layout.size.bytes(), self), dest)?;
             }

compiler/rustc_resolve/src/lib.rs

@@ -1465,16 +1465,14 @@ impl<'a> Resolver<'a> {
 
     /// Entry point to crate resolution.
     pub fn resolve_crate(&mut self, krate: &Crate) {
-        let _prof_timer = self.session.prof.generic_activity("resolve_crate");
+        self.session.time("resolve_crate", || {
-
+            self.session.time("finalize_imports", || ImportResolver { r: self }.finalize_imports());
-        ImportResolver { r: self }.finalize_imports();
+            self.session.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
-        self.finalize_macro_resolutions();
+            self.session.time("late_resolve_crate", || self.late_resolve_crate(krate));
-
+            self.session.time("resolve_check_unused", || self.check_unused(krate));
-        self.late_resolve_crate(krate);
+            self.session.time("resolve_report_errors", || self.report_errors(krate));
-
+            self.session.time("resolve_postprocess", || self.crate_loader.postprocess(krate));
-        self.check_unused(krate);
+        });
-        self.report_errors(krate);
-        self.crate_loader.postprocess(krate);
     }
 
     pub fn traits_in_scope(

compiler/rustc_typeck/src/check/check.rs

@@ -66,7 +66,7 @@ pub(super) fn check_fn<'a, 'tcx>(
     // Create the function context. This is either derived from scratch or,
     // in the case of closures, based on the outer context.
     let mut fcx = FnCtxt::new(inherited, param_env, body.value.hir_id);
-    *fcx.ps.borrow_mut() = UnsafetyState::function(fn_sig.unsafety, fn_id);
+    fcx.ps.set(UnsafetyState::function(fn_sig.unsafety, fn_id));
 
     let tcx = fcx.tcx;
     let sess = tcx.sess;

compiler/rustc_typeck/src/check/coercion.rs

@@ -1472,22 +1472,22 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 fn_output = Some(&fn_decl.output); // `impl Trait` return type
             }
         }
-        if let (Some(sp), Some(fn_output)) = (fcx.ret_coercion_span.borrow().as_ref(), fn_output) {
+        if let (Some(sp), Some(fn_output)) = (fcx.ret_coercion_span.get(), fn_output) {
-            self.add_impl_trait_explanation(&mut err, cause, fcx, expected, *sp, fn_output);
+            self.add_impl_trait_explanation(&mut err, cause, fcx, expected, sp, fn_output);
         }
 
-        if let Some(sp) = fcx.ret_coercion_span.borrow().as_ref() {
+        if let Some(sp) = fcx.ret_coercion_span.get() {
             // If the closure has an explicit return type annotation,
             // then a type error may occur at the first return expression we
             // see in the closure (if it conflicts with the declared
             // return type). Skip adding a note in this case, since it
             // would be incorrect.
-            if !err.span.primary_spans().iter().any(|span| span == sp) {
+            if !err.span.primary_spans().iter().any(|&span| span == sp) {
                 let hir = fcx.tcx.hir();
                 let body_owner = hir.body_owned_by(hir.enclosing_body_owner(fcx.body_id));
                 if fcx.tcx.is_closure(hir.body_owner_def_id(body_owner).to_def_id()) {
                     err.span_note(
-                        *sp,
+                        sp,
                         &format!(
                             "return type inferred to be `{}` here",
                             fcx.resolve_vars_if_possible(expected)

compiler/rustc_typeck/src/check/expr.rs

@@ -680,14 +680,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if self.ret_coercion.is_none() {
             self.tcx.sess.emit_err(ReturnStmtOutsideOfFnBody { span: expr.span });
         } else if let Some(ref e) = expr_opt {
-            if self.ret_coercion_span.borrow().is_none() {
+            if self.ret_coercion_span.get().is_none() {
-                *self.ret_coercion_span.borrow_mut() = Some(e.span);
+                self.ret_coercion_span.set(Some(e.span));
             }
             self.check_return_expr(e);
         } else {
             let mut coercion = self.ret_coercion.as_ref().unwrap().borrow_mut();
-            if self.ret_coercion_span.borrow().is_none() {
+            if self.ret_coercion_span.get().is_none() {
-                *self.ret_coercion_span.borrow_mut() = Some(expr.span);
+                self.ret_coercion_span.set(Some(expr.span));
             }
             let cause = self.cause(expr.span, ObligationCauseCode::ReturnNoExpression);
             if let Some((fn_decl, _)) = self.get_fn_decl(expr.hir_id) {

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -23,7 +23,6 @@ use rustc_span::{self, MultiSpan, Span};
 use rustc_trait_selection::traits::{self, ObligationCauseCode, StatementAsExpression};
 
 use crate::structured_errors::StructuredDiagnostic;
-use std::mem::replace;
 use std::slice;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -589,11 +588,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         blk: &'tcx hir::Block<'tcx>,
         expected: Expectation<'tcx>,
     ) -> Ty<'tcx> {
-        let prev = {
+        let prev = self.ps.replace(self.ps.get().recurse(blk));
-            let mut fcx_ps = self.ps.borrow_mut();
-            let unsafety_state = fcx_ps.recurse(blk);
-            replace(&mut *fcx_ps, unsafety_state)
-        };
 
         // In some cases, blocks have just one exit, but other blocks
         // can be targeted by multiple breaks. This can happen both
@@ -709,7 +704,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         self.write_ty(blk.hir_id, ty);
 
-        *self.ps.borrow_mut() = prev;
+        self.ps.set(prev);
         ty
     }
 

compiler/rustc_typeck/src/check/fn_ctxt/mod.rs

@@ -66,11 +66,11 @@ pub struct FnCtxt<'a, 'tcx> {
     pub(super) in_tail_expr: bool,
 
     /// First span of a return site that we find. Used in error messages.
-    pub(super) ret_coercion_span: RefCell<Option<Span>>,
+    pub(super) ret_coercion_span: Cell<Option<Span>>,
 
     pub(super) resume_yield_tys: Option<(Ty<'tcx>, Ty<'tcx>)>,
 
-    pub(super) ps: RefCell<UnsafetyState>,
+    pub(super) ps: Cell<UnsafetyState>,
 
     /// Whether the last checked node generates a divergence (e.g.,
     /// `return` will set this to `Always`). In general, when entering
@@ -127,9 +127,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ret_coercion_impl_trait: None,
             ret_type_span: None,
             in_tail_expr: false,
-            ret_coercion_span: RefCell::new(None),
+            ret_coercion_span: Cell::new(None),
             resume_yield_tys: None,
-            ps: RefCell::new(UnsafetyState::function(hir::Unsafety::Normal, hir::CRATE_HIR_ID)),
+            ps: Cell::new(UnsafetyState::function(hir::Unsafety::Normal, hir::CRATE_HIR_ID)),
             diverges: Cell::new(Diverges::Maybe),
             has_errors: Cell::new(false),
             enclosing_breakables: RefCell::new(EnclosingBreakables {

compiler/rustc_typeck/src/check/mod.rs

@@ -184,14 +184,14 @@ impl UnsafetyState {
         UnsafetyState { def, unsafety, unsafe_push_count: 0, from_fn: true }
     }
 
-    pub fn recurse(&mut self, blk: &hir::Block<'_>) -> UnsafetyState {
+    pub fn recurse(self, blk: &hir::Block<'_>) -> UnsafetyState {
         use hir::BlockCheckMode;
         match self.unsafety {
             // If this unsafe, then if the outer function was already marked as
             // unsafe we shouldn't attribute the unsafe'ness to the block. This
             // way the block can be warned about instead of ignoring this
             // extraneous block (functions are never warned about).
-            hir::Unsafety::Unsafe if self.from_fn => *self,
+            hir::Unsafety::Unsafe if self.from_fn => self,
 
             unsafety => {
                 let (unsafety, def, count) = match blk.rules {

library/alloc/src/collections/vec_deque/mod.rs

@@ -2646,9 +2646,13 @@ impl<A: Ord> Ord for VecDeque<A> {
 impl<A: Hash> Hash for VecDeque<A> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.len().hash(state);
-        let (a, b) = self.as_slices();
+        // It's not possible to use Hash::hash_slice on slices
-        Hash::hash_slice(a, state);
+        // returned by as_slices method as their length can vary
-        Hash::hash_slice(b, state);
+        // in otherwise identical deques.
+        //
+        // Hasher only guarantees equivalence for the exact same
+        // set of calls to its methods.
+        self.iter().for_each(|elem| elem.hash(state));
     }
 }
 

library/alloc/src/collections/vec_deque/tests.rs

@@ -599,3 +599,43 @@ fn issue_53529() {
         assert_eq!(*a, 2);
     }
 }
+
+#[test]
+fn issue_80303() {
+    use core::iter;
+    use core::num::Wrapping;
+
+    // This is a valid, albeit rather bad hash function implementation.
+    struct SimpleHasher(Wrapping<u64>);
+
+    impl Hasher for SimpleHasher {
+        fn finish(&self) -> u64 {
+            self.0.0
+        }
+
+        fn write(&mut self, bytes: &[u8]) {
+            // This particular implementation hashes value 24 in addition to bytes.
+            // Such an implementation is valid as Hasher only guarantees equivalence
+            // for the exact same set of calls to its methods.
+            for &v in iter::once(&24).chain(bytes) {
+                self.0 = Wrapping(31) * self.0 + Wrapping(u64::from(v));
+            }
+        }
+    }
+
+    fn hash_code(value: impl Hash) -> u64 {
+        let mut hasher = SimpleHasher(Wrapping(1));
+        value.hash(&mut hasher);
+        hasher.finish()
+    }
+
+    // This creates two deques for which values returned by as_slices
+    // method differ.
+    let vda: VecDeque<u8> = (0..10).collect();
+    let mut vdb = VecDeque::with_capacity(10);
+    vdb.extend(5..10);
+    (0..5).rev().for_each(|elem| vdb.push_front(elem));
+    assert_ne!(vda.as_slices(), vdb.as_slices());
+    assert_eq!(vda, vdb);
+    assert_eq!(hash_code(vda), hash_code(vdb));
+}

library/core/src/num/dec2flt/mod.rs

@@ -3,7 +3,7 @@
 //! # Problem statement
 //!
 //! We are given a decimal string such as `12.34e56`. This string consists of integral (`12`),
-//! fractional (`45`), and exponent (`56`) parts. All parts are optional and interpreted as zero
+//! fractional (`34`), and exponent (`56`) parts. All parts are optional and interpreted as zero
 //! when missing.
 //!
 //! We seek the IEEE 754 floating point number that is closest to the exact value of the decimal

library/core/src/ptr/non_null.rs

@@ -19,12 +19,19 @@ use crate::slice::{self, SliceIndex};
 /// as a discriminant -- `Option<NonNull<T>>` has the same size as `*mut T`.
 /// However the pointer may still dangle if it isn't dereferenced.
 ///
-/// Unlike `*mut T`, `NonNull<T>` is covariant over `T`. If this is incorrect
+/// Unlike `*mut T`, `NonNull<T>` was chosen to be covariant over `T`. This makes it
-/// for your use case, you should include some [`PhantomData`] in your type to
+/// possible to use `NonNull<T>` when building covariant types, but introduces the
-/// provide invariance, such as `PhantomData<Cell<T>>` or `PhantomData<&'a mut T>`.
+/// risk of unsoundness if used in a type that shouldn't actually be covariant.
-/// Usually this won't be necessary; covariance is correct for most safe abstractions,
+/// (The opposite choice was made for `*mut T` even though technically the unsoundness
-/// such as `Box`, `Rc`, `Arc`, `Vec`, and `LinkedList`. This is the case because they
+/// could only be caused by calling unsafe functions.)
-/// provide a public API that follows the normal shared XOR mutable rules of Rust.
+///
+/// Covariance is correct for most safe abstractions, such as `Box`, `Rc`, `Arc`, `Vec`,
+/// and `LinkedList`. This is the case because they provide a public API that follows the
+/// normal shared XOR mutable rules of Rust.
+///
+/// If your type cannot safely be covariant, you must ensure it contains some
+/// additional field to provide invariance. Often this field will be a [`PhantomData`]
+/// type like `PhantomData<Cell<T>>` or `PhantomData<&'a mut T>`.
 ///
 /// Notice that `NonNull<T>` has a `From` instance for `&T`. However, this does
 /// not change the fact that mutating through a (pointer derived from a) shared

library/std/src/ffi/os_str.rs

@@ -111,6 +111,7 @@ impl OsString {
     /// let os_string = OsString::new();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn new() -> OsString {
         OsString { inner: Buf::from_string(String::new()) }
     }
@@ -127,6 +128,7 @@ impl OsString {
     /// assert_eq!(os_string.as_os_str(), os_str);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn as_os_str(&self) -> &OsStr {
         self
     }
@@ -145,6 +147,7 @@ impl OsString {
     /// assert_eq!(string, Ok(String::from("foo")));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn into_string(self) -> Result<String, OsString> {
         self.inner.into_string().map_err(|buf| OsString { inner: buf })
     }
@@ -163,6 +166,7 @@ impl OsString {
     /// assert_eq!(&os_string, "foobar");
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn push<T: AsRef<OsStr>>(&mut self, s: T) {
         self.inner.push_slice(&s.as_ref().inner)
     }
@@ -189,6 +193,7 @@ impl OsString {
     /// assert_eq!(capacity, os_string.capacity());
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn with_capacity(capacity: usize) -> OsString {
         OsString { inner: Buf::with_capacity(capacity) }
     }
@@ -207,6 +212,7 @@ impl OsString {
     /// assert_eq!(&os_string, "");
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn clear(&mut self) {
         self.inner.clear()
     }
@@ -224,6 +230,7 @@ impl OsString {
     /// assert!(os_string.capacity() >= 10);
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn capacity(&self) -> usize {
         self.inner.capacity()
     }
@@ -243,6 +250,7 @@ impl OsString {
     /// assert!(s.capacity() >= 10);
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }
@@ -265,6 +273,7 @@ impl OsString {
     /// assert!(s.capacity() >= 10);
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn reserve_exact(&mut self, additional: usize) {
         self.inner.reserve_exact(additional)
     }
@@ -285,6 +294,7 @@ impl OsString {
     /// assert_eq!(3, s.capacity());
     /// ```
     #[stable(feature = "osstring_shrink_to_fit", since = "1.19.0")]
+    #[inline]
     pub fn shrink_to_fit(&mut self) {
         self.inner.shrink_to_fit()
     }
@@ -342,6 +352,7 @@ impl From<String> for OsString {
     /// Converts a [`String`] into a [`OsString`].
     ///
     /// The conversion copies the data, and includes an allocation on the heap.
+    #[inline]
     fn from(s: String) -> OsString {
         OsString { inner: Buf::from_string(s) }
     }
@@ -408,6 +419,7 @@ impl fmt::Debug for OsString {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq for OsString {
+    #[inline]
     fn eq(&self, other: &OsString) -> bool {
         &**self == &**other
     }
@@ -415,6 +427,7 @@ impl PartialEq for OsString {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<str> for OsString {
+    #[inline]
     fn eq(&self, other: &str) -> bool {
         &**self == other
     }
@@ -422,6 +435,7 @@ impl PartialEq<str> for OsString {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<OsString> for str {
+    #[inline]
     fn eq(&self, other: &OsString) -> bool {
         &**other == self
     }
@@ -429,6 +443,7 @@ impl PartialEq<OsString> for str {
 
 #[stable(feature = "os_str_str_ref_eq", since = "1.29.0")]
 impl PartialEq<&str> for OsString {
+    #[inline]
     fn eq(&self, other: &&str) -> bool {
         **self == **other
     }
@@ -436,6 +451,7 @@ impl PartialEq<&str> for OsString {
 
 #[stable(feature = "os_str_str_ref_eq", since = "1.29.0")]
 impl<'a> PartialEq<OsString> for &'a str {
+    #[inline]
     fn eq(&self, other: &OsString) -> bool {
         **other == **self
     }
@@ -539,6 +555,7 @@ impl OsStr {
     /// assert_eq!(os_str.to_str(), Some("foo"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn to_str(&self) -> Option<&str> {
         self.inner.to_str()
     }
@@ -589,6 +606,7 @@ impl OsStr {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         self.inner.to_string_lossy()
     }
@@ -605,6 +623,7 @@ impl OsStr {
     /// assert_eq!(os_string, OsString::from("foo"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn to_os_string(&self) -> OsString {
         OsString { inner: self.inner.to_owned() }
     }
@@ -655,6 +674,7 @@ impl OsStr {
     /// ```
     #[doc(alias = "length")]
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
+    #[inline]
     pub fn len(&self) -> usize {
         self.inner.inner.len()
     }
@@ -696,6 +716,7 @@ impl OsStr {
     /// assert_eq!("grÜße, jÜrgen ❤", s);
     /// ```
     #[unstable(feature = "osstring_ascii", issue = "70516")]
+    #[inline]
     pub fn make_ascii_lowercase(&mut self) {
         self.inner.make_ascii_lowercase()
     }
@@ -721,6 +742,7 @@ impl OsStr {
     /// assert_eq!("GRüßE, JüRGEN ❤", s);
     /// ```
     #[unstable(feature = "osstring_ascii", issue = "70516")]
+    #[inline]
     pub fn make_ascii_uppercase(&mut self) {
         self.inner.make_ascii_uppercase()
     }
@@ -784,6 +806,7 @@ impl OsStr {
     /// assert!(!non_ascii.is_ascii());
     /// ```
     #[unstable(feature = "osstring_ascii", issue = "70516")]
+    #[inline]
     pub fn is_ascii(&self) -> bool {
         self.inner.is_ascii()
     }
@@ -811,6 +834,7 @@ impl OsStr {
 
 #[stable(feature = "box_from_os_str", since = "1.17.0")]
 impl From<&OsStr> for Box<OsStr> {
+    #[inline]
     fn from(s: &OsStr) -> Box<OsStr> {
         let rw = Box::into_raw(s.inner.into_box()) as *mut OsStr;
         unsafe { Box::from_raw(rw) }
@@ -832,6 +856,7 @@ impl From<Cow<'_, OsStr>> for Box<OsStr> {
 impl From<Box<OsStr>> for OsString {
     /// Converts a [`Box`]`<`[`OsStr`]`>` into a `OsString` without copying or
     /// allocating.
+    #[inline]
     fn from(boxed: Box<OsStr>) -> OsString {
         boxed.into_os_string()
     }
@@ -840,6 +865,7 @@ impl From<Box<OsStr>> for OsString {
 #[stable(feature = "box_from_os_string", since = "1.20.0")]
 impl From<OsString> for Box<OsStr> {
     /// Converts a [`OsString`] into a [`Box`]`<OsStr>` without copying or allocating.
+    #[inline]
     fn from(s: OsString) -> Box<OsStr> {
         s.into_boxed_os_str()
     }
@@ -925,6 +951,7 @@ impl<'a> From<Cow<'a, OsStr>> for OsString {
 
 #[stable(feature = "box_default_extra", since = "1.17.0")]
 impl Default for Box<OsStr> {
+    #[inline]
     fn default() -> Box<OsStr> {
         let rw = Box::into_raw(Slice::empty_box()) as *mut OsStr;
         unsafe { Box::from_raw(rw) }
@@ -1075,6 +1102,7 @@ impl OsStr {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Borrow<OsStr> for OsString {
+    #[inline]
     fn borrow(&self) -> &OsStr {
         &self[..]
     }
@@ -1083,9 +1111,11 @@ impl Borrow<OsStr> for OsString {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl ToOwned for OsStr {
     type Owned = OsString;
+    #[inline]
     fn to_owned(&self) -> OsString {
         self.to_os_string()
     }
+    #[inline]
     fn clone_into(&self, target: &mut OsString) {
         self.inner.clone_into(&mut target.inner)
     }
@@ -1093,6 +1123,7 @@ impl ToOwned for OsStr {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for OsStr {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         self
     }
@@ -1123,12 +1154,14 @@ impl AsRef<OsStr> for String {
 }
 
 impl FromInner<Buf> for OsString {
+    #[inline]
     fn from_inner(buf: Buf) -> OsString {
         OsString { inner: buf }
     }
 }
 
 impl IntoInner<Buf> for OsString {
+    #[inline]
     fn into_inner(self) -> Buf {
         self.inner
     }
@@ -1145,6 +1178,7 @@ impl AsInner<Slice> for OsStr {
 impl FromStr for OsString {
     type Err = core::convert::Infallible;
 
+    #[inline]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Ok(OsString::from(s))
     }

library/std/src/path.rs

@@ -401,12 +401,14 @@ impl<'a> PrefixComponent<'a> {
     /// See [`Prefix`]'s documentation for more information on the different
     /// kinds of prefixes.
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn kind(&self) -> Prefix<'a> {
         self.parsed
     }
 
     /// Returns the raw [`OsStr`] slice for this prefix.
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn as_os_str(&self) -> &'a OsStr {
         self.raw
     }
@@ -414,6 +416,7 @@ impl<'a> PrefixComponent<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> cmp::PartialEq for PrefixComponent<'a> {
+    #[inline]
     fn eq(&self, other: &PrefixComponent<'a>) -> bool {
         cmp::PartialEq::eq(&self.parsed, &other.parsed)
     }
@@ -421,6 +424,7 @@ impl<'a> cmp::PartialEq for PrefixComponent<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> cmp::PartialOrd for PrefixComponent<'a> {
+    #[inline]
     fn partial_cmp(&self, other: &PrefixComponent<'a>) -> Option<cmp::Ordering> {
         cmp::PartialOrd::partial_cmp(&self.parsed, &other.parsed)
     }
@@ -428,6 +432,7 @@ impl<'a> cmp::PartialOrd for PrefixComponent<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::Ord for PrefixComponent<'_> {
+    #[inline]
     fn cmp(&self, other: &Self) -> cmp::Ordering {
         cmp::Ord::cmp(&self.parsed, &other.parsed)
     }
@@ -522,6 +527,7 @@ impl<'a> Component<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for Component<'_> {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         self.as_os_str()
     }
@@ -529,6 +535,7 @@ impl AsRef<OsStr> for Component<'_> {
 
 #[stable(feature = "path_component_asref", since = "1.25.0")]
 impl AsRef<Path> for Component<'_> {
+    #[inline]
     fn as_ref(&self) -> &Path {
         self.as_os_str().as_ref()
     }
@@ -750,6 +757,7 @@ impl<'a> Components<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for Components<'_> {
+    #[inline]
     fn as_ref(&self) -> &Path {
         self.as_path()
     }
@@ -757,6 +765,7 @@ impl AsRef<Path> for Components<'_> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for Components<'_> {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         self.as_path().as_os_str()
     }
@@ -792,6 +801,7 @@ impl<'a> Iter<'a> {
     /// assert_eq!(Path::new("foo/bar.txt"), iter.as_path());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn as_path(&self) -> &'a Path {
         self.inner.as_path()
     }
@@ -799,6 +809,7 @@ impl<'a> Iter<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for Iter<'_> {
+    #[inline]
     fn as_ref(&self) -> &Path {
         self.as_path()
     }
@@ -806,6 +817,7 @@ impl AsRef<Path> for Iter<'_> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for Iter<'_> {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         self.as_path().as_os_str()
     }
@@ -815,6 +827,7 @@ impl AsRef<OsStr> for Iter<'_> {
 impl<'a> Iterator for Iter<'a> {
     type Item = &'a OsStr;
 
+    #[inline]
     fn next(&mut self) -> Option<&'a OsStr> {
         self.inner.next().map(Component::as_os_str)
     }
@@ -822,6 +835,7 @@ impl<'a> Iterator for Iter<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> DoubleEndedIterator for Iter<'a> {
+    #[inline]
     fn next_back(&mut self) -> Option<&'a OsStr> {
         self.inner.next_back().map(Component::as_os_str)
     }
@@ -935,6 +949,7 @@ impl FusedIterator for Components<'_> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> cmp::PartialEq for Components<'a> {
+    #[inline]
     fn eq(&self, other: &Components<'a>) -> bool {
         Iterator::eq(self.clone(), other.clone())
     }
@@ -945,6 +960,7 @@ impl cmp::Eq for Components<'_> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> cmp::PartialOrd for Components<'a> {
+    #[inline]
     fn partial_cmp(&self, other: &Components<'a>) -> Option<cmp::Ordering> {
         Iterator::partial_cmp(self.clone(), other.clone())
     }
@@ -952,6 +968,7 @@ impl<'a> cmp::PartialOrd for Components<'a> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::Ord for Components<'_> {
+    #[inline]
     fn cmp(&self, other: &Self) -> cmp::Ordering {
         Iterator::cmp(self.clone(), other.clone())
     }
@@ -985,6 +1002,7 @@ pub struct Ancestors<'a> {
 impl<'a> Iterator for Ancestors<'a> {
     type Item = &'a Path;
 
+    #[inline]
     fn next(&mut self) -> Option<Self::Item> {
         let next = self.next;
         self.next = next.and_then(Path::parent);
@@ -1060,6 +1078,7 @@ pub struct PathBuf {
 }
 
 impl PathBuf {
+    #[inline]
     fn as_mut_vec(&mut self) -> &mut Vec<u8> {
         unsafe { &mut *(self as *mut PathBuf as *mut Vec<u8>) }
     }
@@ -1074,6 +1093,7 @@ impl PathBuf {
     /// let path = PathBuf::new();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn new() -> PathBuf {
         PathBuf { inner: OsString::new() }
     }
@@ -1097,6 +1117,7 @@ impl PathBuf {
     ///
     /// [`with_capacity`]: OsString::with_capacity
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn with_capacity(capacity: usize) -> PathBuf {
         PathBuf { inner: OsString::with_capacity(capacity) }
     }
@@ -1112,6 +1133,7 @@ impl PathBuf {
     /// assert_eq!(Path::new("/test"), p.as_path());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn as_path(&self) -> &Path {
         self
     }
@@ -1315,12 +1337,14 @@ impl PathBuf {
     /// let os_str = p.into_os_string();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn into_os_string(self) -> OsString {
         self.inner
     }
 
     /// Converts this `PathBuf` into a [boxed](Box) [`Path`].
     #[stable(feature = "into_boxed_path", since = "1.20.0")]
+    #[inline]
     pub fn into_boxed_path(self) -> Box<Path> {
         let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path;
         unsafe { Box::from_raw(rw) }
@@ -1330,6 +1354,7 @@ impl PathBuf {
     ///
     /// [`capacity`]: OsString::capacity
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn capacity(&self) -> usize {
         self.inner.capacity()
     }
@@ -1338,6 +1363,7 @@ impl PathBuf {
     ///
     /// [`clear`]: OsString::clear
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn clear(&mut self) {
         self.inner.clear()
     }
@@ -1346,6 +1372,7 @@ impl PathBuf {
     ///
     /// [`reserve`]: OsString::reserve
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }
@@ -1354,6 +1381,7 @@ impl PathBuf {
     ///
     /// [`reserve_exact`]: OsString::reserve_exact
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn reserve_exact(&mut self, additional: usize) {
         self.inner.reserve_exact(additional)
     }
@@ -1362,6 +1390,7 @@ impl PathBuf {
     ///
     /// [`shrink_to_fit`]: OsString::shrink_to_fit
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[inline]
     pub fn shrink_to_fit(&mut self) {
         self.inner.shrink_to_fit()
     }
@@ -1370,6 +1399,7 @@ impl PathBuf {
     ///
     /// [`shrink_to`]: OsString::shrink_to
     #[unstable(feature = "shrink_to", issue = "56431")]
+    #[inline]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         self.inner.shrink_to(min_capacity)
     }
@@ -1400,6 +1430,7 @@ impl From<Box<Path>> for PathBuf {
     /// Converts a `Box<Path>` into a `PathBuf`
     ///
     /// This conversion does not allocate or copy memory.
+    #[inline]
     fn from(boxed: Box<Path>) -> PathBuf {
         boxed.into_path_buf()
     }
@@ -1411,6 +1442,7 @@ impl From<PathBuf> for Box<Path> {
     ///
     /// This conversion currently should not allocate memory,
     /// but this behavior is not guaranteed on all platforms or in all future versions.
+    #[inline]
     fn from(p: PathBuf) -> Box<Path> {
         p.into_boxed_path()
     }
@@ -1426,6 +1458,7 @@ impl Clone for Box<Path> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized + AsRef<OsStr>> From<&T> for PathBuf {
+    #[inline]
     fn from(s: &T) -> PathBuf {
         PathBuf::from(s.as_ref().to_os_string())
     }
@@ -1447,6 +1480,7 @@ impl From<PathBuf> for OsString {
     /// Converts a `PathBuf` into a `OsString`
     ///
     /// This conversion does not allocate or copy memory.
+    #[inline]
     fn from(path_buf: PathBuf) -> OsString {
         path_buf.inner
     }
@@ -1457,6 +1491,7 @@ impl From<String> for PathBuf {
     /// Converts a `String` into a `PathBuf`
     ///
     /// This conversion does not allocate or copy memory.
+    #[inline]
     fn from(s: String) -> PathBuf {
         PathBuf::from(OsString::from(s))
     }
@@ -1466,6 +1501,7 @@ impl From<String> for PathBuf {
 impl FromStr for PathBuf {
     type Err = core::convert::Infallible;
 
+    #[inline]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Ok(PathBuf::from(s))
     }
@@ -1510,6 +1546,7 @@ impl ops::Deref for PathBuf {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Borrow<Path> for PathBuf {
+    #[inline]
     fn borrow(&self) -> &Path {
         self.deref()
     }
@@ -1517,6 +1554,7 @@ impl Borrow<Path> for PathBuf {
 
 #[stable(feature = "default_for_pathbuf", since = "1.17.0")]
 impl Default for PathBuf {
+    #[inline]
     fn default() -> Self {
         PathBuf::new()
     }
@@ -1597,9 +1635,11 @@ impl From<&Path> for Rc<Path> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl ToOwned for Path {
     type Owned = PathBuf;
+    #[inline]
     fn to_owned(&self) -> PathBuf {
         self.to_path_buf()
     }
+    #[inline]
     fn clone_into(&self, target: &mut PathBuf) {
         self.inner.clone_into(&mut target.inner);
     }
@@ -1607,6 +1647,7 @@ impl ToOwned for Path {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::PartialEq for PathBuf {
+    #[inline]
     fn eq(&self, other: &PathBuf) -> bool {
         self.components() == other.components()
     }
@@ -1624,6 +1665,7 @@ impl cmp::Eq for PathBuf {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::PartialOrd for PathBuf {
+    #[inline]
     fn partial_cmp(&self, other: &PathBuf) -> Option<cmp::Ordering> {
         self.components().partial_cmp(other.components())
     }
@@ -1631,6 +1673,7 @@ impl cmp::PartialOrd for PathBuf {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::Ord for PathBuf {
+    #[inline]
     fn cmp(&self, other: &PathBuf) -> cmp::Ordering {
         self.components().cmp(other.components())
     }
@@ -1638,6 +1681,7 @@ impl cmp::Ord for PathBuf {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for PathBuf {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         &self.inner[..]
     }
@@ -1745,6 +1789,7 @@ impl Path {
     /// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn as_os_str(&self) -> &OsStr {
         &self.inner
     }
@@ -1766,6 +1811,7 @@ impl Path {
     /// assert_eq!(path.to_str(), Some("foo.txt"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn to_str(&self) -> Option<&str> {
         self.inner.to_str()
     }
@@ -1791,6 +1837,7 @@ impl Path {
     /// Had `path` contained invalid unicode, the `to_string_lossy` call might
     /// have returned `"fo<66>.txt"`.
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         self.inner.to_string_lossy()
     }
@@ -1854,6 +1901,7 @@ impl Path {
     ///
     /// [`is_absolute`]: Path::is_absolute
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn is_relative(&self) -> bool {
         !self.is_absolute()
     }
@@ -1879,6 +1927,7 @@ impl Path {
     /// assert!(Path::new("/etc/passwd").has_root());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn has_root(&self) -> bool {
         self.components().has_root()
     }
@@ -1941,6 +1990,7 @@ impl Path {
     ///
     /// [`parent`]: Path::parent
     #[stable(feature = "path_ancestors", since = "1.28.0")]
+    #[inline]
     pub fn ancestors(&self) -> Ancestors<'_> {
         Ancestors { next: Some(&self) }
     }
@@ -2265,6 +2315,7 @@ impl Path {
     /// assert_eq!(it.next(), None)
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn iter(&self) -> Iter<'_> {
         Iter { inner: self.components() }
     }
@@ -2284,6 +2335,7 @@ impl Path {
     /// println!("{}", path.display());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn display(&self) -> Display<'_> {
         Display { path: self }
     }
@@ -2305,6 +2357,7 @@ impl Path {
     /// println!("{:?}", metadata.file_type());
     /// ```
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn metadata(&self) -> io::Result<fs::Metadata> {
         fs::metadata(self)
     }
@@ -2323,6 +2376,7 @@ impl Path {
     /// println!("{:?}", metadata.file_type());
     /// ```
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn symlink_metadata(&self) -> io::Result<fs::Metadata> {
         fs::symlink_metadata(self)
     }
@@ -2341,6 +2395,7 @@ impl Path {
     /// assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));
     /// ```
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn canonicalize(&self) -> io::Result<PathBuf> {
         fs::canonicalize(self)
     }
@@ -2358,6 +2413,7 @@ impl Path {
     /// let path_link = path.read_link().expect("read_link call failed");
     /// ```
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn read_link(&self) -> io::Result<PathBuf> {
         fs::read_link(self)
     }
@@ -2382,6 +2438,7 @@ impl Path {
     /// }
     /// ```
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn read_dir(&self) -> io::Result<fs::ReadDir> {
         fs::read_dir(self)
     }
@@ -2406,6 +2463,7 @@ impl Path {
     /// This is a convenience function that coerces errors to false. If you want to
     /// check errors, call [`fs::metadata`].
     #[stable(feature = "path_ext", since = "1.5.0")]
+    #[inline]
     pub fn exists(&self) -> bool {
         fs::metadata(self).is_ok()
     }
@@ -2480,6 +2538,7 @@ impl Path {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for Path {
+    #[inline]
     fn as_ref(&self) -> &OsStr {
         &self.inner
     }
@@ -2531,6 +2590,7 @@ impl fmt::Display for Display<'_> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::PartialEq for Path {
+    #[inline]
     fn eq(&self, other: &Path) -> bool {
         self.components().eq(other.components())
     }
@@ -2550,6 +2610,7 @@ impl cmp::Eq for Path {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::PartialOrd for Path {
+    #[inline]
     fn partial_cmp(&self, other: &Path) -> Option<cmp::Ordering> {
         self.components().partial_cmp(other.components())
     }
@@ -2557,6 +2618,7 @@ impl cmp::PartialOrd for Path {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl cmp::Ord for Path {
+    #[inline]
     fn cmp(&self, other: &Path) -> cmp::Ordering {
         self.components().cmp(other.components())
     }
@@ -2564,6 +2626,7 @@ impl cmp::Ord for Path {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for Path {
+    #[inline]
     fn as_ref(&self) -> &Path {
         self
     }
@@ -2571,6 +2634,7 @@ impl AsRef<Path> for Path {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for OsStr {
+    #[inline]
     fn as_ref(&self) -> &Path {
         Path::new(self)
     }
@@ -2578,6 +2642,7 @@ impl AsRef<Path> for OsStr {
 
 #[stable(feature = "cow_os_str_as_ref_path", since = "1.8.0")]
 impl AsRef<Path> for Cow<'_, OsStr> {
+    #[inline]
     fn as_ref(&self) -> &Path {
         Path::new(self)
     }
@@ -2585,6 +2650,7 @@ impl AsRef<Path> for Cow<'_, OsStr> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for OsString {
+    #[inline]
     fn as_ref(&self) -> &Path {
         Path::new(self)
     }
@@ -2600,6 +2666,7 @@ impl AsRef<Path> for str {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<Path> for String {
+    #[inline]
     fn as_ref(&self) -> &Path {
         Path::new(self)
     }
@@ -2617,6 +2684,7 @@ impl AsRef<Path> for PathBuf {
 impl<'a> IntoIterator for &'a PathBuf {
     type Item = &'a OsStr;
     type IntoIter = Iter<'a>;
+    #[inline]
     fn into_iter(self) -> Iter<'a> {
         self.iter()
     }
@@ -2626,6 +2694,7 @@ impl<'a> IntoIterator for &'a PathBuf {
 impl<'a> IntoIterator for &'a Path {
     type Item = &'a OsStr;
     type IntoIter = Iter<'a>;
+    #[inline]
     fn into_iter(self) -> Iter<'a> {
         self.iter()
     }

src/librustdoc/clean/mod.rs

@@ -1096,7 +1096,10 @@ impl Clean<Item> for hir::TraitItem<'_> {
                     AssocTypeItem(bounds.clean(cx), default.clean(cx))
                 }
             };
-            Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx)
+            let what_rustc_thinks =
+                Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx);
+            // Trait items always inherit the trait's visibility -- we don't want to show `pub`.
+            Item { visibility: Inherited, ..what_rustc_thinks }
         })
     }
 }
@@ -1131,7 +1134,21 @@ impl Clean<Item> for hir::ImplItem<'_> {
                     )
                 }
             };
-            Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx)
+
+            let what_rustc_thinks =
+                Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx);
+            let parent_item = cx.tcx.hir().expect_item(cx.tcx.hir().get_parent_item(self.hir_id));
+            if let hir::ItemKind::Impl(impl_) = &parent_item.kind {
+                if impl_.of_trait.is_some() {
+                    // Trait impl items always inherit the impl's visibility --
+                    // we don't want to show `pub`.
+                    Item { visibility: Inherited, ..what_rustc_thinks }
+                } else {
+                    what_rustc_thinks
+                }
+            } else {
+                panic!("found impl item with non-impl parent {:?}", parent_item);
+            }
         })
     }
 }

src/librustdoc/formats/renderer.rs

@@ -12,6 +12,9 @@ use crate::formats::cache::{Cache, CACHE_KEY};
 /// backend renderer has hooks for initialization, documenting an item, entering and exiting a
 /// module, and cleanup/finalizing output.
 crate trait FormatRenderer<'tcx>: Clone {
+    /// Gives a description of the renderer. Used for performance profiling.
+    fn descr() -> &'static str;
+
     /// Sets up any state required for the renderer. When this is called the cache has already been
     /// populated.
     fn init(
@@ -57,16 +60,20 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
     edition: Edition,
     tcx: TyCtxt<'tcx>,
 ) -> Result<(), Error> {
-    let (krate, mut cache) = Cache::from_krate(
+    let (krate, mut cache) = tcx.sess.time("create_format_cache", || {
-        render_info.clone(),
+        Cache::from_krate(
-        options.document_private,
+            render_info.clone(),
-        &options.extern_html_root_urls,
+            options.document_private,
-        &options.output,
+            &options.extern_html_root_urls,
-        krate,
+            &options.output,
-    );
+            krate,
+        )
+    });
+    let prof = &tcx.sess.prof;
 
-    let (mut format_renderer, mut krate) =
+    let (mut format_renderer, mut krate) = prof
-        T::init(krate, options, render_info, edition, &mut cache, tcx)?;
+        .extra_verbose_generic_activity("create_renderer", T::descr())
+        .run(|| T::init(krate, options, render_info, edition, &mut cache, tcx))?;
 
     let cache = Arc::new(cache);
     // Freeze the cache now that the index has been built. Put an Arc into TLS for future
@@ -83,6 +90,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
     // Render the crate documentation
     let mut work = vec![(format_renderer.clone(), item)];
 
+    let unknown = rustc_span::Symbol::intern("<unknown item>");
     while let Some((mut cx, item)) = work.pop() {
         if item.is_mod() {
             // modules are special because they add a namespace. We also need to
@@ -91,6 +99,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
             if name.is_empty() {
                 panic!("Unexpected module with empty name");
             }
+            let _timer = prof.generic_activity_with_arg("render_mod_item", name.as_str());
 
             cx.mod_item_in(&item, &name, &cache)?;
             let module = match *item.kind {
@@ -104,9 +113,10 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
 
             cx.mod_item_out(&name)?;
         } else if item.name.is_some() {
-            cx.item(item, &cache)?;
+            prof.generic_activity_with_arg("render_item", &*item.name.unwrap_or(unknown).as_str())
+                .run(|| cx.item(item, &cache))?;
         }
     }
-
+    prof.extra_verbose_generic_activity("renderer_after_krate", T::descr())
-    format_renderer.after_krate(&krate, &cache, diag)
+        .run(|| format_renderer.after_krate(&krate, &cache, diag))
 }

src/librustdoc/html/render/mod.rs

@@ -383,6 +383,10 @@ crate fn initial_ids() -> Vec<String> {
 
 /// Generates the documentation for `crate` into the directory `dst`
 impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
+    fn descr() -> &'static str {
+        "html"
+    }
+
     fn init(
         mut krate: clean::Crate,
         options: RenderOptions,

src/librustdoc/json/mod.rs

@@ -125,6 +125,10 @@ impl JsonRenderer<'_> {
 }
 
 impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
+    fn descr() -> &'static str {
+        "json"
+    }
+
     fn init(
         krate: clean::Crate,
         options: RenderOptions,

src/librustdoc/lib.rs

@@ -540,7 +540,7 @@ fn main_options(options: config::Options) -> MainResult {
                 sess.fatal("Compilation failed, aborting rustdoc");
             }
 
-            let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess).take();
+            let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess).peek_mut();
 
             global_ctxt.enter(|tcx| {
                 let (mut krate, render_info, render_opts) = sess.time("run_global_ctxt", || {

src/test/rustdoc/visibility.rs

@@ -42,3 +42,35 @@ mod a {
         struct FooBPriv;
     }
 }
+
+// @has 'foo/trait.PubTrait.html' '//pre' 'pub trait PubTrait'
+//
+// @has 'foo/trait.PubTrait.html' '//pre' 'type Type;'
+// @!has 'foo/trait.PubTrait.html' '//pre' 'pub type Type;'
+//
+// @has 'foo/trait.PubTrait.html' '//pre' 'const CONST: usize;'
+// @!has 'foo/trait.PubTrait.html' '//pre' 'pub const CONST: usize;'
+//
+// @has 'foo/trait.PubTrait.html' '//pre' 'fn function();'
+// @!has 'foo/trait.PubTrait.html' '//pre' 'pub fn function();'
+
+pub trait PubTrait {
+    type Type;
+    const CONST: usize;
+    fn function();
+}
+
+// @has 'foo/struct.FooPublic.html' '//code' 'type Type'
+// @!has 'foo/struct.FooPublic.html' '//code' 'pub type Type'
+//
+// @has 'foo/struct.FooPublic.html' '//code' 'const CONST: usize'
+// @!has 'foo/struct.FooPublic.html' '//code' 'pub const CONST: usize'
+//
+// @has 'foo/struct.FooPublic.html' '//code' 'fn function()'
+// @!has 'foo/struct.FooPublic.html' '//code' 'pub fn function()'
+
+impl PubTrait for FooPublic {
+    type Type = usize;
+    const CONST: usize = 0;
+    fn function() {}
+}

src/test/ui/closures/local-type-mix.rs

@@ -0,0 +1,17 @@
+// Check that using the parameter name in its type does not ICE.
+// edition:2018
+
+#![feature(async_closure)]
+
+fn main() {
+    let _ = |x: x| x; //~ ERROR expected type
+    let _ = |x: bool| -> x { x }; //~ ERROR expected type
+    let _ = async move |x: x| x; //~ ERROR expected type
+    let _ = async move |x: bool| -> x { x }; //~ ERROR expected type
+}
+
+fn foo(x: x) {} //~ ERROR expected type
+fn foo_ret(x: bool) -> x {} //~ ERROR expected type
+
+async fn async_foo(x: x) {} //~ ERROR expected type
+async fn async_foo_ret(x: bool) -> x {} //~ ERROR expected type

src/test/ui/closures/local-type-mix.stderr

@@ -0,0 +1,51 @@
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:7:17
+   |
+LL |     let _ = |x: x| x;
+   |                 ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:8:26
+   |
+LL |     let _ = |x: bool| -> x { x };
+   |                          ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:9:28
+   |
+LL |     let _ = async move |x: x| x;
+   |                            ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:10:37
+   |
+LL |     let _ = async move |x: bool| -> x { x };
+   |                                     ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:13:11
+   |
+LL | fn foo(x: x) {}
+   |           ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:14:24
+   |
+LL | fn foo_ret(x: bool) -> x {}
+   |                        ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:16:23
+   |
+LL | async fn async_foo(x: x) {}
+   |                       ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type-mix.rs:17:36
+   |
+LL | async fn async_foo_ret(x: bool) -> x {}
+   |                                    ^ not a type
+
+error: aborting due to 8 previous errors
+
+For more information about this error, try `rustc --explain E0573`.

src/test/ui/mir/issue-80742.stderr

@@ -1,3 +1,17 @@
+error[E0080]: evaluation of constant value failed
+  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   |
+LL |     intrinsics::size_of::<T>()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     size_of called on unsized type `dyn Debug`
+   |     inside `std::mem::size_of::<dyn Debug>` at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   | 
+  ::: $DIR/issue-80742.rs:23:10
+   |
+LL |     [u8; size_of::<T>() + 1]: ,
+   |          -------------- inside `Inline::<dyn Debug>::{constant#0}` at $DIR/issue-80742.rs:23:10
+
 error[E0599]: no function or associated item named `new` found for struct `Inline<dyn Debug>` in the current scope
   --> $DIR/issue-80742.rs:31:36
    |
@@ -21,6 +35,20 @@ LL |   pub trait Debug {
    = note: the method `new` exists but the following trait bounds were not satisfied:
            `dyn Debug: Sized`
 
+error[E0080]: evaluation of constant value failed
+  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   |
+LL |     intrinsics::size_of::<T>()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     size_of called on unsized type `dyn Debug`
+   |     inside `std::mem::size_of::<dyn Debug>` at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   | 
+  ::: $DIR/issue-80742.rs:15:10
+   |
+LL |     [u8; size_of::<T>() + 1]: ,
+   |          -------------- inside `Inline::<dyn Debug>::{constant#0}` at $DIR/issue-80742.rs:15:10
+
 error[E0277]: the size for values of type `dyn Debug` cannot be known at compilation time
   --> $DIR/issue-80742.rs:31:15
    |
@@ -36,7 +64,7 @@ help: consider relaxing the implicit `Sized` restriction
 LL | struct Inline<T: ?Sized>
    |                ^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0277, E0599.
+Some errors have detailed explanations: E0080, E0277, E0599.
-For more information about an error, try `rustc --explain E0277`.
+For more information about an error, try `rustc --explain E0080`.

src/tools/cargo

@@ -1 +1 @@
-Subproject commit a73e5b7d567c3036b296fc6b33ed52c5edcd882e
+Subproject commit 783bc43c660bf39c1e562c8c429b32078ad3099b