Auto merge of #104168 - GuillaumeGomez:rollup-tf4edqc, r=GuillaumeGomez

Rollup of 12 pull requests

Successful merges:

 - #103928 (Add 'ty_error_with_guaranteed' and 'const_error_with_guaranteed')
 - #104027 (Place config.toml in current working directory if config not found)
 - #104093 (disable btree size tests on Miri)
 - #104097 (run alloc benchmarks in Miri and fix UB)
 - #104104 (Add split-debuginfo print option)
 - #104109 (rustdoc: Add mutable to the description)
 - #104113 (Fix `const_fn_trait_ref_impl`, add test for it)
 - #104114 (Fix invalid background-image file name)
 - #104132 (fix: lint against lint functions)
 - #104139 (Clarify licensing situation of MPSC and SPSC queue)
 - #104147 (Remove an address comparison from the parser)
 - #104165 (Add llvm-main to triagebot.toml)

Failed merges:

 - #104115 (Migrate crate-search element to CSS variables)

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

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -299,8 +299,8 @@ fn infer_opaque_definition_from_instantiation(
         if errors.is_empty() {
             definition_ty
         } else {
-            infcx.err_ctxt().report_fulfillment_errors(&errors, None);
-            self.tcx.ty_error()
+            let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None);
+            self.tcx.ty_error_with_guaranteed(reported)
         }
     }
 }

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -247,12 +247,13 @@ pub(crate) fn create(mut self) -> CreateResult<'tcx> {
                     .and(type_op::normalize::Normalize::new(ty))
                     .fully_perform(self.infcx)
                     .unwrap_or_else(|_| {
-                        self.infcx
+                        let reported = self
+                            .infcx
                             .tcx
                             .sess
                             .delay_span_bug(span, &format!("failed to normalize {:?}", ty));
                         TypeOpOutput {
-                            output: self.infcx.tcx.ty_error(),
+                            output: self.infcx.tcx.ty_error_with_guaranteed(reported),
                             constraints: None,
                             error_info: None,
                         }

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -233,11 +233,11 @@ pub(crate) fn type_check<'mir, 'tcx>(
             let mut hidden_type = infcx.resolve_vars_if_possible(decl.hidden_type);
             trace!("finalized opaque type {:?} to {:#?}", opaque_type_key, hidden_type.ty.kind());
             if hidden_type.has_non_region_infer() {
-                infcx.tcx.sess.delay_span_bug(
+                let reported = infcx.tcx.sess.delay_span_bug(
                     decl.hidden_type.span,
                     &format!("could not resolve {:#?}", hidden_type.ty.kind()),
                 );
-                hidden_type.ty = infcx.tcx.ty_error();
+                hidden_type.ty = infcx.tcx.ty_error_with_guaranteed(reported);
             }
 
             (opaque_type_key, (hidden_type, decl.origin))

compiler/rustc_driver/src/lib.rs

@@ -736,6 +736,17 @@ fn print_crate_info(
             // Any output here interferes with Cargo's parsing of other printed output
             NativeStaticLibs => {}
             LinkArgs => {}
+            SplitDebuginfo => {
+                use rustc_target::spec::SplitDebuginfo::{Off, Packed, Unpacked};
+
+                for split in &[Off, Packed, Unpacked] {
+                    let stable = sess.target.options.supported_split_debuginfo.contains(split);
+                    let unstable_ok = sess.unstable_options();
+                    if stable || unstable_ok {
+                        println!("{}", split);
+                    }
+                }
+            }
         }
     }
     Compilation::Stop

compiler/rustc_errors/src/diagnostic_builder.rs

@@ -482,9 +482,9 @@ pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>) {
     /// In the meantime, though, callsites are required to deal with the "bug"
     /// locally in whichever way makes the most sense.
     #[track_caller]
-    pub fn delay_as_bug(&mut self) {
+    pub fn delay_as_bug(&mut self) -> G {
         self.downgrade_to_delayed_bug();
-        self.emit();
+        self.emit()
     }
 
     forward!(

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1201,7 +1201,8 @@ fn add_predicates_for_ast_type_binding(
                     (_, _) => {
                         let got = if let Some(_) = term.ty() { "type" } else { "constant" };
                         let expected = def_kind.descr(assoc_item_def_id);
-                        tcx.sess
+                        let reported = tcx
+                            .sess
                             .struct_span_err(
                                 binding.span,
                                 &format!("expected {expected} bound, found {got}"),
@@ -1212,11 +1213,14 @@ fn add_predicates_for_ast_type_binding(
                             )
                             .emit();
                         term = match def_kind {
-                            hir::def::DefKind::AssocTy => tcx.ty_error().into(),
+                            hir::def::DefKind::AssocTy => {
+                                tcx.ty_error_with_guaranteed(reported).into()
+                            }
                             hir::def::DefKind::AssocConst => tcx
-                                .const_error(
+                                .const_error_with_guaranteed(
                                     tcx.bound_type_of(assoc_item_def_id)
                                         .subst(tcx, projection_ty.skip_binder().substs),
+                                    reported,
                                 )
                                 .into(),
                             _ => unreachable!(),
@@ -1334,8 +1338,9 @@ trait here instead: `trait NewTrait: {} {{}}`",
                 .map(|&(trait_ref, _, _)| trait_ref.def_id())
                 .find(|&trait_ref| tcx.is_trait_alias(trait_ref))
                 .map(|trait_ref| tcx.def_span(trait_ref));
-            tcx.sess.emit_err(TraitObjectDeclaredWithNoTraits { span, trait_alias_span });
-            return tcx.ty_error();
+            let reported =
+                tcx.sess.emit_err(TraitObjectDeclaredWithNoTraits { span, trait_alias_span });
+            return tcx.ty_error_with_guaranteed(reported);
         }
 
         // Check that there are no gross object safety violations;
@@ -1345,14 +1350,14 @@ trait here instead: `trait NewTrait: {} {{}}`",
             let object_safety_violations =
                 astconv_object_safety_violations(tcx, item.trait_ref().def_id());
             if !object_safety_violations.is_empty() {
-                report_object_safety_error(
+                let reported = report_object_safety_error(
                     tcx,
                     span,
                     item.trait_ref().def_id(),
                     &object_safety_violations,
                 )
                 .emit();
-                return tcx.ty_error();
+                return tcx.ty_error_with_guaranteed(reported);
             }
         }
 
@@ -2112,13 +2117,13 @@ fn qpath_to_ty(
                 "Type"
             };
 
-            self.report_ambiguous_associated_type(
+            let reported = self.report_ambiguous_associated_type(
                 span,
                 type_name,
                 &path_str,
                 item_segment.ident.name,
             );
-            return tcx.ty_error();
+            return tcx.ty_error_with_guaranteed(reported)
         };
 
         debug!("qpath_to_ty: self_type={:?}", self_ty);
@@ -2560,8 +2565,7 @@ pub fn res_to_ty(
                     {
                         err.span_note(impl_.self_ty.span, "not a concrete type");
                     }
-                    err.emit();
-                    tcx.ty_error()
+                    tcx.ty_error_with_guaranteed(err.emit())
                 } else {
                     self.normalize_ty(span, ty)
                 }

compiler/rustc_hir_analysis/src/check/compare_method.rs

@@ -611,11 +611,11 @@ pub fn collect_trait_impl_trait_tys<'tcx>(
                 collected_tys.insert(def_id, ty);
             }
             Err(err) => {
-                tcx.sess.delay_span_bug(
+                let reported = tcx.sess.delay_span_bug(
                     return_span,
                     format!("could not fully resolve: {ty} => {err:?}"),
                 );
-                collected_tys.insert(def_id, tcx.ty_error());
+                collected_tys.insert(def_id, tcx.ty_error_with_guaranteed(reported));
             }
         }
     }

compiler/rustc_hir_analysis/src/collect.rs

@@ -512,8 +512,7 @@ fn projected_ty_from_poly_trait_ref(
                 }
                 _ => {}
             }
-            err.emit();
-            self.tcx().ty_error()
+            self.tcx().ty_error_with_guaranteed(err.emit())
         }
     }
 

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -698,7 +698,7 @@ fn visit_trait_item(&mut self, it: &'tcx TraitItem<'tcx>) {
     }
 
     let Some(hidden) = locator.found else {
-        tcx.sess.emit_err(UnconstrainedOpaqueType {
+        let reported = tcx.sess.emit_err(UnconstrainedOpaqueType {
             span: tcx.def_span(def_id),
             name: tcx.item_name(tcx.local_parent(def_id).to_def_id()),
             what: match tcx.hir().get(scope) {
@@ -708,7 +708,7 @@ fn visit_trait_item(&mut self, it: &'tcx TraitItem<'tcx>) {
                 _ => "item",
             },
         });
-        return tcx.ty_error();
+        return tcx.ty_error_with_guaranteed(reported);
     };
 
     // Only check against typeck if we didn't already error

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1639,9 +1639,9 @@ pub(crate) fn coerce_inner<'a>(
                 if visitor.ret_exprs.len() > 0 && let Some(expr) = expression {
                     self.note_unreachable_loop_return(&mut err, &expr, &visitor.ret_exprs);
                 }
-                err.emit_unless(unsized_return);
+                let reported = err.emit_unless(unsized_return);
 
-                self.final_ty = Some(fcx.tcx.ty_error());
+                self.final_ty = Some(fcx.tcx.ty_error_with_guaranteed(reported));
             }
         }
     }

compiler/rustc_hir_typeck/src/expr.rs

@@ -80,14 +80,14 @@ fn check_expr_meets_expectation_or_error(
         // coercions from ! to `expected`.
         if ty.is_never() {
             if let Some(adjustments) = self.typeck_results.borrow().adjustments().get(expr.hir_id) {
-                self.tcx().sess.delay_span_bug(
+                let reported = self.tcx().sess.delay_span_bug(
                     expr.span,
                     "expression with never type wound up being adjusted",
                 );
                 return if let [Adjustment { kind: Adjust::NeverToAny, target }] = &adjustments[..] {
                     target.to_owned()
                 } else {
-                    self.tcx().ty_error()
+                    self.tcx().ty_error_with_guaranteed(reported)
                 };
             }
 
@@ -396,8 +396,7 @@ fn check_expr_unary(
                         {
                             err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
                         }
-                        err.emit();
-                        oprnd_t = tcx.ty_error();
+                        oprnd_t = tcx.ty_error_with_guaranteed(err.emit());
                     }
                 }
                 hir::UnOp::Not => {
@@ -1097,12 +1096,8 @@ fn check_expr_assign(
 
             // If the assignment expression itself is ill-formed, don't
             // bother emitting another error
-            if lhs_ty.references_error() || rhs_ty.references_error() {
-                err.delay_as_bug()
-            } else {
-                err.emit();
-            }
-            return self.tcx.ty_error();
+            let reported = err.emit_unless(lhs_ty.references_error() || rhs_ty.references_error());
+            return self.tcx.ty_error_with_guaranteed(reported);
         }
 
         let lhs_ty = self.check_expr_with_needs(&lhs, Needs::MutPlace);
@@ -2777,8 +2772,8 @@ fn check_expr_index(
                             );
                         }
                     }
-                    err.emit();
-                    self.tcx.ty_error()
+                    let reported = err.emit();
+                    self.tcx.ty_error_with_guaranteed(reported)
                 }
             }
         }

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -1212,9 +1212,8 @@ pub fn instantiate_value_path(
                             }
                         }
                     }
-                    err.emit();
-
-                    return (tcx.ty_error(), res);
+                    let reported = err.emit();
+                    return (tcx.ty_error_with_guaranteed(reported), res);
                 }
             }
         } else {

compiler/rustc_hir_typeck/src/op.rs

@@ -529,8 +529,8 @@ fn check_overloaded_binop(
                         }
                     }
                 }
-                err.emit();
-                self.tcx.ty_error()
+                let reported = err.emit();
+                self.tcx.ty_error_with_guaranteed(reported)
             }
         };
 

compiler/rustc_hir_typeck/src/pat.rs

@@ -1278,12 +1278,12 @@ fn check_pat_tuple(
         let element_tys = tcx.mk_type_list(element_tys_iter);
         let pat_ty = tcx.mk_ty(ty::Tuple(element_tys));
         if let Some(mut err) = self.demand_eqtype_pat_diag(span, expected, pat_ty, ti) {
-            err.emit();
+            let reported = err.emit();
             // Walk subpatterns with an expected type of `err` in this case to silence
             // further errors being emitted when using the bindings. #50333
-            let element_tys_iter = (0..max_len).map(|_| tcx.ty_error());
+            let element_tys_iter = (0..max_len).map(|_| tcx.ty_error_with_guaranteed(reported));
             for (_, elem) in elements.iter().enumerate_and_adjust(max_len, ddpos) {
-                self.check_pat(elem, tcx.ty_error(), def_bm, ti);
+                self.check_pat(elem, tcx.ty_error_with_guaranteed(reported), def_bm, ti);
             }
             tcx.mk_tup(element_tys_iter)
         } else {

compiler/rustc_hir_typeck/src/place_op.rs

@@ -90,8 +90,11 @@ fn negative_index(
                 Applicability::MachineApplicable,
             );
         }
-        err.emit();
-        Some((self.tcx.ty_error(), self.tcx.ty_error()))
+        let reported = err.emit();
+        Some((
+            self.tcx.ty_error_with_guaranteed(reported),
+            self.tcx.ty_error_with_guaranteed(reported),
+        ))
     }
 
     /// To type-check `base_expr[index_expr]`, we progressively autoderef

compiler/rustc_lint/src/context.rs

@@ -579,6 +579,7 @@ pub trait LintContext: Sized {
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     fn lookup_with_diagnostics(
         &self,
         lint: &'static Lint,
@@ -882,6 +883,7 @@ fn lookup_with_diagnostics(
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     fn lookup<S: Into<MultiSpan>>(
         &self,
         lint: &'static Lint,
@@ -908,6 +910,7 @@ fn emit_spanned_lint<S: Into<MultiSpan>>(
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     fn struct_span_lint<S: Into<MultiSpan>>(
         &self,
         lint: &'static Lint,
@@ -933,6 +936,7 @@ fn emit_lint(&self, lint: &'static Lint, decorator: impl for<'a> DecorateLint<'a
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     fn lint(
         &self,
         lint: &'static Lint,

compiler/rustc_lint/src/levels.rs

@@ -1073,6 +1073,7 @@ pub fn lint_level(&self, lint: &'static Lint) -> LevelAndSource {
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     pub(crate) fn struct_lint(
         &self,
         lint: &'static Lint,

compiler/rustc_lint/src/lib.rs

@@ -36,6 +36,7 @@
 #![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(never_type)]
+#![feature(rustc_attrs)]
 #![recursion_limit = "256"]
 
 #[macro_use]

compiler/rustc_middle/src/ty/context.rs

@@ -1283,6 +1283,12 @@ pub fn create_global_ctxt(
         }
     }
 
+    /// Constructs a `TyKind::Error` type with current `ErrorGuaranteed`
+    #[track_caller]
+    pub fn ty_error_with_guaranteed(self, reported: ErrorGuaranteed) -> Ty<'tcx> {
+        self.mk_ty(Error(reported))
+    }
+
     /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
     #[track_caller]
     pub fn ty_error(self) -> Ty<'tcx> {
@@ -1297,6 +1303,16 @@ pub fn ty_error_with_message<S: Into<MultiSpan>>(self, span: S, msg: &str) -> Ty
         self.mk_ty(Error(reported))
     }
 
+    /// Like [TyCtxt::ty_error] but for constants, with current `ErrorGuaranteed`
+    #[track_caller]
+    pub fn const_error_with_guaranteed(
+        self,
+        ty: Ty<'tcx>,
+        reported: ErrorGuaranteed,
+    ) -> Const<'tcx> {
+        self.mk_const(ty::ConstKind::Error(reported), ty)
+    }
+
     /// Like [TyCtxt::ty_error] but for constants.
     #[track_caller]
     pub fn const_error(self, ty: Ty<'tcx>) -> Const<'tcx> {
@@ -2856,6 +2872,7 @@ pub fn emit_lint(
     /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation.
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
+    #[rustc_lint_diagnostics]
     pub fn struct_lint_node(
         self,
         lint: &'static Lint,

compiler/rustc_middle/src/ty/visit.rs

@@ -97,7 +97,11 @@ fn references_error(&self) -> bool {
     }
     fn error_reported(&self) -> Result<(), ErrorGuaranteed> {
         if self.references_error() {
-            Err(ErrorGuaranteed::unchecked_claim_error_was_emitted())
+            if let Some(reported) = ty::tls::with(|tcx| tcx.sess.has_errors()) {
+                Err(reported)
+            } else {
+                bug!("expect tcx.sess.has_errors return true");
+            }
         } else {
             Ok(())
         }

compiler/rustc_parse/src/parser/expr.rs

@@ -833,16 +833,11 @@ fn parse_and_disallow_postfix_after_cast(
                 ("cast", None)
             };
 
-        // Save the memory location of expr before parsing any following postfix operators.
-        // This will be compared with the memory location of the output expression.
-        // If they different we can assume we parsed another expression because the existing expression is not reallocated.
-        let addr_before = &*cast_expr as *const _ as usize;
         let with_postfix = self.parse_dot_or_call_expr_with_(cast_expr, span)?;
-        let changed = addr_before != &*with_postfix as *const _ as usize;
 
         // Check if an illegal postfix operator has been added after the cast.
-        // If the resulting expression is not a cast, or has a different memory location, it is an illegal postfix operator.
-        if !matches!(with_postfix.kind, ExprKind::Cast(_, _) | ExprKind::Type(_, _)) || changed {
+        // If the resulting expression is not a cast, it is an illegal postfix operator.
+        if !matches!(with_postfix.kind, ExprKind::Cast(_, _) | ExprKind::Type(_, _)) {
             let msg = format!(
                 "{cast_kind} cannot be followed by {}",
                 match with_postfix.kind {

compiler/rustc_session/src/config.rs

@@ -548,6 +548,7 @@ pub enum PrintRequest {
     NativeStaticLibs,
     StackProtectorStrategies,
     LinkArgs,
+    SplitDebuginfo,
 }
 
 pub enum Input {
@@ -1806,6 +1807,7 @@ fn collect_print_requests(
         ("stack-protector-strategies", PrintRequest::StackProtectorStrategies),
         ("target-spec-json", PrintRequest::TargetSpec),
         ("link-args", PrintRequest::LinkArgs),
+        ("split-debuginfo", PrintRequest::SplitDebuginfo),
     ];
 
     prints.extend(matches.opt_strs("print").into_iter().map(|req| {

library/alloc/src/alloc/tests.rs

@@ -22,7 +22,6 @@ fn allocate_zeroed() {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn alloc_owned_small(b: &mut Bencher) {
     b.iter(|| {
         let _: Box<_> = Box::new(10);

library/alloc/src/collections/btree/node/tests.rs

@@ -94,6 +94,7 @@ fn test_partial_eq() {
 
 #[test]
 #[cfg(target_arch = "x86_64")]
+#[cfg_attr(miri, ignore)] // We'd like to run Miri with layout randomization
 fn test_sizes() {
     assert_eq!(core::mem::size_of::<LeafNode<(), ()>>(), 16);
     assert_eq!(core::mem::size_of::<LeafNode<i64, i64>>(), 16 + CAPACITY * 2 * 8);

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

@@ -3,7 +3,6 @@
 use super::*;
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_push_back_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -16,7 +15,6 @@ fn bench_push_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_push_front_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -29,12 +27,15 @@ fn bench_push_front_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_pop_back_100(b: &mut test::Bencher) {
-    let mut deq = VecDeque::<i32>::with_capacity(101);
+    let size = 100;
+    let mut deq = VecDeque::<i32>::with_capacity(size + 1);
+    // We'll mess with private state to pretend like `deq` is filled.
+    // Make sure the buffer is initialized so that we don't read uninit memory.
+    unsafe { deq.ptr().write_bytes(0u8, size + 1) };
 
     b.iter(|| {
-        deq.head = 100;
+        deq.head = size;
         deq.tail = 0;
         while !deq.is_empty() {
             test::black_box(deq.pop_back());
@@ -43,9 +44,9 @@ fn bench_pop_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_retain_whole_10000(b: &mut test::Bencher) {
-    let v = (1..100000).collect::<VecDeque<u32>>();
+    let size = if cfg!(miri) { 1000 } else { 100000 };
+    let v = (1..size).collect::<VecDeque<u32>>();
 
     b.iter(|| {
         let mut v = v.clone();
@@ -54,9 +55,9 @@ fn bench_retain_whole_10000(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_retain_odd_10000(b: &mut test::Bencher) {
-    let v = (1..100000).collect::<VecDeque<u32>>();
+    let size = if cfg!(miri) { 1000 } else { 100000 };
+    let v = (1..size).collect::<VecDeque<u32>>();
 
     b.iter(|| {
         let mut v = v.clone();
@@ -65,23 +66,26 @@ fn bench_retain_odd_10000(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_retain_half_10000(b: &mut test::Bencher) {
-    let v = (1..100000).collect::<VecDeque<u32>>();
+    let size = if cfg!(miri) { 1000 } else { 100000 };
+    let v = (1..size).collect::<VecDeque<u32>>();
 
     b.iter(|| {
         let mut v = v.clone();
-        v.retain(|x| *x > 50000)
+        v.retain(|x| *x > size / 2)
     })
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_pop_front_100(b: &mut test::Bencher) {
-    let mut deq = VecDeque::<i32>::with_capacity(101);
+    let size = 100;
+    let mut deq = VecDeque::<i32>::with_capacity(size + 1);
+    // We'll mess with private state to pretend like `deq` is filled.
+    // Make sure the buffer is initialized so that we don't read uninit memory.
+    unsafe { deq.ptr().write_bytes(0u8, size + 1) };
 
     b.iter(|| {
-        deq.head = 100;
+        deq.head = size;
         deq.tail = 0;
         while !deq.is_empty() {
             test::black_box(deq.pop_front());

library/core/src/ops/function.rs

@@ -576,9 +576,10 @@ mod impls {
     use crate::marker::Tuple;
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: Tuple, F: ?Sized> Fn<A> for &F
+    #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")]
+    impl<A: Tuple, F: ?Sized> const Fn<A> for &F
     where
-        F: Fn<A>,
+        F: ~const Fn<A>,
     {
         extern "rust-call" fn call(&self, args: A) -> F::Output {
             (**self).call(args)
@@ -586,9 +587,10 @@ extern "rust-call" fn call(&self, args: A) -> F::Output {
     }
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: Tuple, F: ?Sized> FnMut<A> for &F
+    #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")]
+    impl<A: Tuple, F: ?Sized> const FnMut<A> for &F
     where
-        F: Fn<A>,
+        F: ~const Fn<A>,
     {
         extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output {
             (**self).call(args)
@@ -596,9 +598,10 @@ extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output {
     }
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: Tuple, F: ?Sized> FnOnce<A> for &F
+    #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")]
+    impl<A: Tuple, F: ?Sized> const FnOnce<A> for &F
     where
-        F: Fn<A>,
+        F: ~const Fn<A>,
     {
         type Output = F::Output;
 
@@ -608,9 +611,10 @@ extern "rust-call" fn call_once(self, args: A) -> F::Output {
     }
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: Tuple, F: ?Sized> FnMut<A> for &mut F
+    #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")]
+    impl<A: Tuple, F: ?Sized> const FnMut<A> for &mut F
     where
-        F: FnMut<A>,
+        F: ~const FnMut<A>,
     {
         extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output {
             (*self).call_mut(args)
@@ -618,9 +622,10 @@ extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output {
     }
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: Tuple, F: ?Sized> FnOnce<A> for &mut F
+    #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")]
+    impl<A: Tuple, F: ?Sized> const FnOnce<A> for &mut F
     where
-        F: FnMut<A>,
+        F: ~const FnMut<A>,
     {
         type Output = F::Output;
         extern "rust-call" fn call_once(self, args: A) -> F::Output {

library/core/src/slice/mod.rs

@@ -3524,8 +3524,8 @@ pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T]) {
         }
     }
 
-    /// Transmute the slice to a slice of another type, ensuring alignment of the types is
-    /// maintained.
+    /// Transmute the mutable slice to a mutable slice of another type, ensuring alignment of the
+    /// types is maintained.
     ///
     /// This method splits the slice into three distinct slices: prefix, correctly aligned middle
     /// slice of a new type, and the suffix slice. The method may make the middle slice the greatest

library/std/src/sync/mpsc/mpsc_queue.rs

@@ -8,8 +8,15 @@
 //! method, and see the method for more information about it. Due to this
 //! caveat, this queue might not be appropriate for all use-cases.
 
-// https://www.1024cores.net/home/lock-free-algorithms
-//                          /queues/non-intrusive-mpsc-node-based-queue
+// The original implementation is based off:
+// https://www.1024cores.net/home/lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue
+//
+// Note that back when the code was imported, it was licensed under the BSD-2-Clause license:
+// http://web.archive.org/web/20110411011612/https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue
+//
+// The original author of the code agreed to relicense it under `MIT OR Apache-2.0` in 2017, so as
+// of today the license of this file is the same as the rest of the codebase:
+// https://github.com/rust-lang/rust/pull/42149
 
 #[cfg(all(test, not(target_os = "emscripten")))]
 mod tests;

library/std/src/sync/mpsc/spsc_queue.rs

@@ -4,7 +4,15 @@
 //! concurrently between two threads. This data structure is safe to use and
 //! enforces the semantics that there is one pusher and one popper.
 
+// The original implementation is based off:
 // https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue
+//
+// Note that back when the code was imported, it was licensed under the BSD-2-Clause license:
+// http://web.archive.org/web/20110411011612/https://www.1024cores.net/home/lock-free-algorithms/queues/unbounded-spsc-queue
+//
+// The original author of the code agreed to relicense it under `MIT OR Apache-2.0` in 2017, so as
+// of today the license of this file is the same as the rest of the codebase:
+// https://github.com/rust-lang/rust/pull/42149
 
 #[cfg(all(test, not(target_os = "emscripten")))]
 mod tests;

src/bootstrap/bin/main.rs

@@ -35,7 +35,7 @@ fn main() {
 
     // NOTE: Since `./configure` generates a `config.toml`, distro maintainers will see the
     // changelog warning, not the `x.py setup` message.
-    let suggest_setup = !config.config.exists() && !matches!(config.cmd, Subcommand::Setup { .. });
+    let suggest_setup = config.config.is_none() && !matches!(config.cmd, Subcommand::Setup { .. });
     if suggest_setup {
         println!("warning: you have not made a `config.toml`");
         println!(

src/bootstrap/config.rs

@@ -80,7 +80,7 @@ pub struct Config {
     pub keep_stage_std: Vec<u32>,
     pub src: PathBuf,
     /// defaults to `config.toml`
-    pub config: PathBuf,
+    pub config: Option<PathBuf>,
     pub jobs: Option<u32>,
     pub cmd: Subcommand,
     pub incremental: bool,
@@ -926,8 +926,10 @@ pub fn parse(args: &[String]) -> Config {
         // Give a hard error if `--config` or `RUST_BOOTSTRAP_CONFIG` are set to a missing path,
         // but not if `config.toml` hasn't been created.
         let mut toml = if !using_default_path || toml_path.exists() {
+            config.config = Some(toml_path.clone());
             get_toml(&toml_path)
         } else {
+            config.config = None;
             TomlConfig::default()
         };
 
@@ -942,7 +944,6 @@ pub fn parse(args: &[String]) -> Config {
         }
 
         config.changelog_seen = toml.changelog_seen;
-        config.config = toml_path;
 
         let build = toml.build.unwrap_or_default();
 

src/bootstrap/setup.rs

@@ -82,7 +82,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 }
 
 pub fn setup(config: &Config, profile: Profile) {
-    let path = &config.config;
+    let path = &config.config.clone().unwrap_or(PathBuf::from("config.toml"));
 
     if path.exists() {
         eprintln!(

src/librustdoc/html/static/css/rustdoc.css

@@ -854,7 +854,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	background-size: 20px;
 	background-position: calc(100% - 2px) 56%;
 	/* image is black color, themes should apply a "filter" property to change the color */
-	background-image: url("down-arrow-2d685a4bae708e15.svg");
+	background-image: url("down-arrow-927217e04c7463ac.svg");
 }
 #crate-search > option {
 	font-size: 1rem;

src/test/run-make/valid-print-requests/valid-print-requests.stderr

@@ -1,2 +1,2 @@
-error: unknown print request `uwu`. Valid print requests are: `crate-name`, `file-names`, `sysroot`, `target-libdir`, `cfg`, `calling-conventions`, `target-list`, `target-cpus`, `target-features`, `relocation-models`, `code-models`, `tls-models`, `native-static-libs`, `stack-protector-strategies`, `target-spec-json`, `link-args`
+error: unknown print request `uwu`. Valid print requests are: `crate-name`, `file-names`, `sysroot`, `target-libdir`, `cfg`, `calling-conventions`, `target-list`, `target-cpus`, `target-features`, `relocation-models`, `code-models`, `tls-models`, `native-static-libs`, `stack-protector-strategies`, `target-spec-json`, `link-args`, `split-debuginfo`
 

src/test/ui/consts/fn_trait_refs.rs

@@ -0,0 +1,80 @@
+// build-pass
+
+#![feature(const_fn_trait_ref_impls)]
+#![feature(fn_traits)]
+#![feature(unboxed_closures)]
+#![feature(const_trait_impl)]
+#![feature(const_mut_refs)]
+#![feature(const_cmp)]
+#![feature(const_refs_to_cell)]
+
+use std::marker::Destruct;
+
+const fn tester_fn<T>(f: T) -> T::Output
+where
+    T: ~const Fn<()> + ~const Destruct,
+{
+    f()
+}
+
+const fn tester_fn_mut<T>(mut f: T) -> T::Output
+where
+    T: ~const FnMut<()> + ~const Destruct,
+{
+    f()
+}
+
+const fn tester_fn_once<T>(f: T) -> T::Output
+where
+    T: ~const FnOnce<()>,
+{
+    f()
+}
+
+const fn test_fn<T>(mut f: T) -> (T::Output, T::Output, T::Output)
+where
+    T: ~const Fn<()> + ~const Destruct,
+{
+    (
+        // impl<A: Tuple, F: ~const Fn + ?Sized> const Fn<A> for &F
+        tester_fn(&f),
+        // impl<A: Tuple, F: ~const Fn + ?Sized> const FnMut<A> for &F
+        tester_fn_mut(&f),
+        // impl<A: Tuple, F: ~const Fn + ?Sized> const FnOnce<A> for &F
+        tester_fn_once(&f),
+    )
+}
+
+const fn test_fn_mut<T>(mut f: T) -> (T::Output, T::Output)
+where
+    T: ~const FnMut<()> + ~const Destruct,
+{
+    (
+        // impl<A: Tuple, F: ~const FnMut + ?Sized> const FnMut<A> for &mut F
+        tester_fn_mut(&mut f),
+        // impl<A: Tuple, F: ~const FnMut + ?Sized> const FnOnce<A> for &mut F
+        tester_fn_once(&mut f),
+    )
+}
+const fn test(i: i32) -> i32 {
+    i + 1
+}
+
+const fn main() {
+    const fn one() -> i32 {
+        1
+    };
+    const fn two() -> i32 {
+        2
+    };
+
+    // FIXME(const_cmp_tuple)
+    let test_one = test_fn(one);
+    assert!(test_one.0 == 1);
+    assert!(test_one.1 == 1);
+    assert!(test_one.2 == 1);
+
+    let test_two = test_fn_mut(two);
+    assert!(test_two.0 == 1);
+    assert!(test_two.1 == 1);
+}

triagebot.toml

@@ -12,6 +12,7 @@ allow-unauthenticated = [
     "T-*",
     "WG-*",
     "const-hack",
+    "llvm-main",
     "needs-fcp",
     "relnotes",
     "requires-nightly",