Merge pull request #4345 from rust-lang/rustup-2025-05-23

Automatic Rustup

.github/workflows/ci.yml

@@ -73,6 +73,15 @@ jobs:
     needs: [ calculate_matrix ]
     runs-on: "${{ matrix.os }}"
     timeout-minutes: 360
+    # The bors environment contains secrets required for elevated workflows (try and auto builds),
+    # which need to access e.g. S3 and upload artifacts. We want to provide access to that
+    # environment only on the try/auto branches, which are only accessible to bors.
+    # This also ensures that PR CI (which doesn't get write access to S3) works, as it cannot
+    # access the environment.
+    #
+    # We only enable the environment for the rust-lang/rust repository, so that rust-lang-ci/rust
+    # CI works until we migrate off it (since that repository doesn't contain the environment).
+    environment: ${{ ((github.repository == 'rust-lang/rust' && (github.ref == 'refs/heads/try' || github.ref == 'refs/heads/auto')) && 'bors') || '' }}
     env:
       CI_JOB_NAME: ${{ matrix.name }}
       CI_JOB_DOC_URL: ${{ matrix.doc_url }}

Cargo.lock

@@ -582,13 +582,11 @@ dependencies = [
 name = "clippy_dev"
 version = "0.0.1"
 dependencies = [
- "aho-corasick",
  "chrono",
  "clap",
  "indoc",
  "itertools",
  "opener",
- "shell-escape",
  "walkdir",
 ]
 
@@ -3809,6 +3807,7 @@ dependencies = [
  "rustc_abi",
  "rustc_ast",
  "rustc_attr_data_structures",
+ "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_fluent_macro",
@@ -4887,12 +4886,6 @@ dependencies = [
  "lazy_static",
 ]
 
-[[package]]
-name = "shell-escape"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45bb67a18fa91266cc7807181f62f9178a6873bfad7dc788c42e6430db40184f"
-
 [[package]]
 name = "shlex"
 version = "1.3.0"

compiler/rustc_attr_parsing/src/attributes/util.rs

@@ -26,3 +26,33 @@ pub fn is_builtin_attr(attr: &impl AttributeExt) -> bool {
 pub fn find_crate_name(attrs: &[impl AttributeExt]) -> Option<Symbol> {
     first_attr_value_str_by_name(attrs, sym::crate_name)
 }
+
+pub fn is_doc_alias_attrs_contain_symbol<'tcx, T: AttributeExt + 'tcx>(
+    attrs: impl Iterator<Item = &'tcx T>,
+    symbol: Symbol,
+) -> bool {
+    let doc_attrs = attrs.filter(|attr| attr.has_name(sym::doc));
+    for attr in doc_attrs {
+        let Some(values) = attr.meta_item_list() else {
+            continue;
+        };
+        let alias_values = values.iter().filter(|v| v.has_name(sym::alias));
+        for v in alias_values {
+            if let Some(nested) = v.meta_item_list() {
+                // #[doc(alias("foo", "bar"))]
+                let mut iter = nested.iter().filter_map(|item| item.lit()).map(|item| item.symbol);
+                if iter.any(|s| s == symbol) {
+                    return true;
+                }
+            } else if let Some(meta) = v.meta_item()
+                && let Some(lit) = meta.name_value_literal()
+            {
+                // #[doc(alias = "foo")]
+                if lit.symbol == symbol {
+                    return true;
+                }
+            }
+        }
+    }
+    false
+}

compiler/rustc_attr_parsing/src/lib.rs

@@ -90,7 +90,9 @@ pub mod parser;
 mod session_diagnostics;
 
 pub use attributes::cfg::*;
-pub use attributes::util::{find_crate_name, is_builtin_attr, parse_version};
+pub use attributes::util::{
+    find_crate_name, is_builtin_attr, is_doc_alias_attrs_contain_symbol, parse_version,
+};
 pub use context::{AttributeParser, OmitDoc};
 
 rustc_fluent_macro::fluent_messages! { "../messages.ftl" }

compiler/rustc_codegen_cranelift/patches/0027-sysroot_tests-128bit-atomic-operations.patch

@@ -17,7 +17,7 @@ index 1e336bf..35e6f54 100644
 @@ -2,5 +2,4 @@
  // tidy-alphabetical-start
 -#![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
- #![cfg_attr(test, feature(cfg_match))]
+ #![cfg_attr(test, feature(cfg_select))]
  #![feature(alloc_layout_extra)]
  #![feature(array_chunks)]
 diff --git a/coretests/tests/atomic.rs b/coretests/tests/atomic.rs

compiler/rustc_data_structures/src/flock.rs

@@ -4,7 +4,7 @@
 //! green/native threading. This is just a bare-bones enough solution for
 //! librustdoc, it is not production quality at all.
 
-cfg_match! {
+cfg_select! {
     target_os = "linux" => {
         mod linux;
         use linux as imp;

compiler/rustc_data_structures/src/lib.rs

@@ -19,7 +19,7 @@
 #![feature(ascii_char_variants)]
 #![feature(assert_matches)]
 #![feature(auto_traits)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(extend_one)]

compiler/rustc_data_structures/src/profiling.rs

@@ -860,7 +860,7 @@ fn get_thread_id() -> u32 {
 }
 
 // Memory reporting
-cfg_match! {
+cfg_select! {
     windows => {
         pub fn get_resident_set_size() -> Option<usize> {
             use windows::{

compiler/rustc_hir_typeck/Cargo.toml

@@ -9,6 +9,7 @@ itertools = "0.12"
 rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr_data_structures = { path = "../rustc_attr_data_structures" }
+rustc_attr_parsing = { path = "../rustc_attr_parsing" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1190,9 +1190,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     (ty::FnDef(..), ty::FnDef(..)) => {
                         // Don't reify if the function types have a LUB, i.e., they
                         // are the same function and their parameters have a LUB.
-                        match self
-                            .commit_if_ok(|_| self.at(cause, self.param_env).lub(prev_ty, new_ty))
-                        {
+                        match self.commit_if_ok(|_| {
+                            // We need to eagerly handle nested obligations due to lazy norm.
+                            if self.next_trait_solver() {
+                                let ocx = ObligationCtxt::new(self);
+                                let value = ocx.lub(cause, self.param_env, prev_ty, new_ty)?;
+                                if ocx.select_where_possible().is_empty() {
+                                    Ok(InferOk {
+                                        value,
+                                        obligations: ocx.into_pending_obligations(),
+                                    })
+                                } else {
+                                    Err(TypeError::Mismatch)
+                                }
+                            } else {
+                                self.at(cause, self.param_env).lub(prev_ty, new_ty)
+                            }
+                        }) {
                             // We have a LUB of prev_ty and new_ty, just return it.
                             Ok(ok) => return Ok(self.register_infer_ok_obligations(ok)),
                             Err(_) => {

compiler/rustc_hir_typeck/src/expr.rs

@@ -532,14 +532,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ExprKind::Break(destination, ref expr_opt) => {
                 self.check_expr_break(destination, expr_opt.as_deref(), expr)
             }
-            ExprKind::Continue(destination) => {
-                if destination.target_id.is_ok() {
-                    tcx.types.never
-                } else {
-                    // There was an error; make type-check fail.
-                    Ty::new_misc_error(tcx)
-                }
-            }
+            ExprKind::Continue(destination) => self.check_expr_continue(destination, expr),
             ExprKind::Ret(ref expr_opt) => self.check_expr_return(expr_opt.as_deref(), expr),
             ExprKind::Become(call) => self.check_expr_become(call, expr),
             ExprKind::Let(let_expr) => self.check_expr_let(let_expr, expr.hir_id),
@@ -989,6 +982,31 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    fn check_expr_continue(
+        &self,
+        destination: hir::Destination,
+        expr: &'tcx hir::Expr<'tcx>,
+    ) -> Ty<'tcx> {
+        if let Ok(target_id) = destination.target_id {
+            if let hir::Node::Expr(hir::Expr { kind: ExprKind::Loop(..), .. }) =
+                self.tcx.hir_node(target_id)
+            {
+                self.tcx.types.never
+            } else {
+                // Liveness linting assumes `continue`s all point to loops. We'll report an error
+                // in `check_mod_loops`, but make sure we don't run liveness (#113379, #121623).
+                let guar = self.dcx().span_delayed_bug(
+                    expr.span,
+                    "found `continue` not pointing to loop, but no error reported",
+                );
+                Ty::new_error(self.tcx, guar)
+            }
+        } else {
+            // There was an error; make type-check fail.
+            Ty::new_misc_error(self.tcx)
+        }
+    }
+
     fn check_expr_return(
         &self,
         expr_opt: Option<&'tcx hir::Expr<'tcx>>,

compiler/rustc_hir_typeck/src/lib.rs

@@ -2,6 +2,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -1,7 +1,9 @@
+use std::assert_matches::debug_assert_matches;
 use std::cell::{Cell, RefCell};
 use std::cmp::max;
 use std::ops::Deref;
 
+use rustc_attr_parsing::is_doc_alias_attrs_contain_symbol;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sso::SsoHashSet;
 use rustc_errors::Applicability;
@@ -15,7 +17,7 @@ use rustc_infer::traits::ObligationCauseCode;
 use rustc_middle::middle::stability;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::elaborate::supertrait_def_ids;
-use rustc_middle::ty::fast_reject::{TreatParams, simplify_type};
+use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams, simplify_type};
 use rustc_middle::ty::{
     self, AssocItem, AssocItemContainer, GenericArgs, GenericArgsRef, GenericParamDefKind,
     ParamEnvAnd, Ty, TyCtxt, TypeVisitableExt, Upcast,
@@ -806,8 +808,8 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                     );
                 }
             }
-            ty::Param(p) => {
-                self.assemble_inherent_candidates_from_param(p);
+            ty::Param(_) => {
+                self.assemble_inherent_candidates_from_param(raw_self_ty);
             }
             ty::Bool
             | ty::Char
@@ -908,18 +910,16 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     }
 
     #[instrument(level = "debug", skip(self))]
-    fn assemble_inherent_candidates_from_param(&mut self, param_ty: ty::ParamTy) {
+    fn assemble_inherent_candidates_from_param(&mut self, param_ty: Ty<'tcx>) {
+        debug_assert_matches!(param_ty.kind(), ty::Param(_));
+
+        let tcx = self.tcx;
         let bounds = self.param_env.caller_bounds().iter().filter_map(|predicate| {
             let bound_predicate = predicate.kind();
             match bound_predicate.skip_binder() {
-                ty::ClauseKind::Trait(trait_predicate) => {
-                    match *trait_predicate.trait_ref.self_ty().kind() {
-                        ty::Param(p) if p == param_ty => {
-                            Some(bound_predicate.rebind(trait_predicate.trait_ref))
-                        }
-                        _ => None,
-                    }
-                }
+                ty::ClauseKind::Trait(trait_predicate) => DeepRejectCtxt::relate_rigid_rigid(tcx)
+                    .types_may_unify(param_ty, trait_predicate.trait_ref.self_ty())
+                    .then(|| bound_predicate.rebind(trait_predicate.trait_ref)),
                 ty::ClauseKind::RegionOutlives(_)
                 | ty::ClauseKind::TypeOutlives(_)
                 | ty::ClauseKind::Projection(_)
@@ -2333,10 +2333,13 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         };
         let hir_id = self.fcx.tcx.local_def_id_to_hir_id(local_def_id);
         let attrs = self.fcx.tcx.hir_attrs(hir_id);
+
+        if is_doc_alias_attrs_contain_symbol(attrs.into_iter(), method.name) {
+            return true;
+        }
+
         for attr in attrs {
-            if attr.has_name(sym::doc) {
-                // do nothing
-            } else if attr.has_name(sym::rustc_confusables) {
+            if attr.has_name(sym::rustc_confusables) {
                 let Some(confusables) = attr.meta_item_list() else {
                     continue;
                 };
@@ -2348,33 +2351,6 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         return true;
                     }
                 }
-                continue;
-            } else {
-                continue;
-            };
-            let Some(values) = attr.meta_item_list() else {
-                continue;
-            };
-            for v in values {
-                if !v.has_name(sym::alias) {
-                    continue;
-                }
-                if let Some(nested) = v.meta_item_list() {
-                    // #[doc(alias("foo", "bar"))]
-                    for n in nested {
-                        if let Some(lit) = n.lit()
-                            && method.name == lit.symbol
-                        {
-                            return true;
-                        }
-                    }
-                } else if let Some(meta) = v.meta_item()
-                    && let Some(lit) = meta.name_value_literal()
-                    && method.name == lit.symbol
-                {
-                    // #[doc(alias = "foo")]
-                    return true;
-                }
             }
         }
         false

compiler/rustc_interface/src/passes.rs

@@ -45,7 +45,7 @@ use crate::interface::Compiler;
 use crate::{errors, limits, proc_macro_decls, util};
 
 pub fn parse<'a>(sess: &'a Session) -> ast::Crate {
-    let krate = sess
+    let mut krate = sess
         .time("parse_crate", || {
             let mut parser = unwrap_or_emit_fatal(match &sess.io.input {
                 Input::File(file) => new_parser_from_file(&sess.psess, file, None),
@@ -64,6 +64,12 @@ pub fn parse<'a>(sess: &'a Session) -> ast::Crate {
         input_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS", "ast-stats-1");
     }
 
+    rustc_builtin_macros::cmdline_attrs::inject(
+        &mut krate,
+        &sess.psess,
+        &sess.opts.unstable_opts.crate_attr,
+    );
+
     krate
 }
 
@@ -805,17 +811,11 @@ pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
 
 pub fn create_and_enter_global_ctxt<T, F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> T>(
     compiler: &Compiler,
-    mut krate: rustc_ast::Crate,
+    krate: rustc_ast::Crate,
     f: F,
 ) -> T {
     let sess = &compiler.sess;
 
-    rustc_builtin_macros::cmdline_attrs::inject(
-        &mut krate,
-        &sess.psess,
-        &sess.opts.unstable_opts.crate_attr,
-    );
-
     let pre_configured_attrs = rustc_expand::config::pre_configure_attrs(sess, &krate.attrs);
 
     let crate_name = get_crate_name(sess, &pre_configured_attrs);

compiler/rustc_lint/messages.ftl

@@ -13,6 +13,8 @@ lint_ambiguous_negative_literals = `-` has lower precedence than method calls, w
 lint_ambiguous_wide_pointer_comparisons = ambiguous wide pointer comparison, the comparison includes metadata which may not be expected
     .addr_metadata_suggestion = use explicit `std::ptr::eq` method to compare metadata and addresses
     .addr_suggestion = use `std::ptr::addr_eq` or untyped pointers to only compare their addresses
+    .cast_suggestion = use untyped pointers to only compare their addresses
+    .expect_suggestion = or expect the lint to compare the pointers metadata and addresses
 
 lint_associated_const_elided_lifetime = {$elided ->
         [true] `&` without an explicit lifetime name cannot be used here

compiler/rustc_lint/src/lints.rs

@@ -1782,13 +1782,20 @@ pub(crate) enum InvalidNanComparisonsSuggestion {
 #[derive(LintDiagnostic)]
 pub(crate) enum AmbiguousWidePointerComparisons<'a> {
     #[diag(lint_ambiguous_wide_pointer_comparisons)]
-    Spanful {
+    SpanfulEq {
         #[subdiagnostic]
         addr_suggestion: AmbiguousWidePointerComparisonsAddrSuggestion<'a>,
         #[subdiagnostic]
         addr_metadata_suggestion: Option<AmbiguousWidePointerComparisonsAddrMetadataSuggestion<'a>>,
     },
     #[diag(lint_ambiguous_wide_pointer_comparisons)]
+    SpanfulCmp {
+        #[subdiagnostic]
+        cast_suggestion: AmbiguousWidePointerComparisonsCastSuggestion<'a>,
+        #[subdiagnostic]
+        expect_suggestion: AmbiguousWidePointerComparisonsExpectSuggestion<'a>,
+    },
+    #[diag(lint_ambiguous_wide_pointer_comparisons)]
     #[help(lint_addr_metadata_suggestion)]
     #[help(lint_addr_suggestion)]
     Spanless,
@@ -1816,48 +1823,67 @@ pub(crate) struct AmbiguousWidePointerComparisonsAddrMetadataSuggestion<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub(crate) enum AmbiguousWidePointerComparisonsAddrSuggestion<'a> {
-    #[multipart_suggestion(
-        lint_addr_suggestion,
-        style = "verbose",
-        // FIXME(#53934): make machine-applicable again
-        applicability = "maybe-incorrect"
+#[multipart_suggestion(
+    lint_addr_suggestion,
+    style = "verbose",
+    // FIXME(#53934): make machine-applicable again
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AmbiguousWidePointerComparisonsAddrSuggestion<'a> {
+    pub(crate) ne: &'a str,
+    pub(crate) deref_left: &'a str,
+    pub(crate) deref_right: &'a str,
+    pub(crate) l_modifiers: &'a str,
+    pub(crate) r_modifiers: &'a str,
+    #[suggestion_part(code = "{ne}std::ptr::addr_eq({deref_left}")]
+    pub(crate) left: Span,
+    #[suggestion_part(code = "{l_modifiers}, {deref_right}")]
+    pub(crate) middle: Span,
+    #[suggestion_part(code = "{r_modifiers})")]
+    pub(crate) right: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+    lint_cast_suggestion,
+    style = "verbose",
+    // FIXME(#53934): make machine-applicable again
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AmbiguousWidePointerComparisonsCastSuggestion<'a> {
+    pub(crate) deref_left: &'a str,
+    pub(crate) deref_right: &'a str,
+    pub(crate) paren_left: &'a str,
+    pub(crate) paren_right: &'a str,
+    pub(crate) l_modifiers: &'a str,
+    pub(crate) r_modifiers: &'a str,
+    #[suggestion_part(code = "({deref_left}")]
+    pub(crate) left_before: Option<Span>,
+    #[suggestion_part(code = "{l_modifiers}{paren_left}.cast::<()>()")]
+    pub(crate) left_after: Span,
+    #[suggestion_part(code = "({deref_right}")]
+    pub(crate) right_before: Option<Span>,
+    #[suggestion_part(code = "{r_modifiers}{paren_right}.cast::<()>()")]
+    pub(crate) right_after: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+    lint_expect_suggestion,
+    style = "verbose",
+    // FIXME(#53934): make machine-applicable again
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AmbiguousWidePointerComparisonsExpectSuggestion<'a> {
+    pub(crate) paren_left: &'a str,
+    pub(crate) paren_right: &'a str,
+    // FIXME(#127436): Adjust once resolved
+    #[suggestion_part(
+        code = r#"{{ #[expect(ambiguous_wide_pointer_comparisons, reason = "...")] {paren_left}"#
     )]
-    AddrEq {
-        ne: &'a str,
-        deref_left: &'a str,
-        deref_right: &'a str,
-        l_modifiers: &'a str,
-        r_modifiers: &'a str,
-        #[suggestion_part(code = "{ne}std::ptr::addr_eq({deref_left}")]
-        left: Span,
-        #[suggestion_part(code = "{l_modifiers}, {deref_right}")]
-        middle: Span,
-        #[suggestion_part(code = "{r_modifiers})")]
-        right: Span,
-    },
-    #[multipart_suggestion(
-        lint_addr_suggestion,
-        style = "verbose",
-        // FIXME(#53934): make machine-applicable again
-        applicability = "maybe-incorrect"
-    )]
-    Cast {
-        deref_left: &'a str,
-        deref_right: &'a str,
-        paren_left: &'a str,
-        paren_right: &'a str,
-        l_modifiers: &'a str,
-        r_modifiers: &'a str,
-        #[suggestion_part(code = "({deref_left}")]
-        left_before: Option<Span>,
-        #[suggestion_part(code = "{l_modifiers}{paren_left}.cast::<()>()")]
-        left_after: Span,
-        #[suggestion_part(code = "({deref_right}")]
-        right_before: Option<Span>,
-        #[suggestion_part(code = "{r_modifiers}{paren_right}.cast::<()>()")]
-        right_after: Span,
-    },
+    pub(crate) before: Span,
+    #[suggestion_part(code = "{paren_right} }}")]
+    pub(crate) after: Span,
 }
 
 #[derive(LintDiagnostic)]

compiler/rustc_lint/src/types.rs

@@ -24,7 +24,8 @@ mod improper_ctypes;
 
 use crate::lints::{
     AmbiguousWidePointerComparisons, AmbiguousWidePointerComparisonsAddrMetadataSuggestion,
-    AmbiguousWidePointerComparisonsAddrSuggestion, AtomicOrderingFence, AtomicOrderingLoad,
+    AmbiguousWidePointerComparisonsAddrSuggestion, AmbiguousWidePointerComparisonsCastSuggestion,
+    AmbiguousWidePointerComparisonsExpectSuggestion, AtomicOrderingFence, AtomicOrderingLoad,
     AtomicOrderingStore, ImproperCTypes, InvalidAtomicOrderingDiag, InvalidNanComparisons,
     InvalidNanComparisonsSuggestion, UnpredictableFunctionPointerComparisons,
     UnpredictableFunctionPointerComparisonsSuggestion, UnusedComparisons, UsesPowerAlignment,
@@ -362,6 +363,7 @@ fn lint_wide_pointer<'tcx>(
     let ne = if cmpop == ComparisonOp::BinOp(hir::BinOpKind::Ne) { "!" } else { "" };
     let is_eq_ne = matches!(cmpop, ComparisonOp::BinOp(hir::BinOpKind::Eq | hir::BinOpKind::Ne));
     let is_dyn_comparison = l_inner_ty_is_dyn && r_inner_ty_is_dyn;
+    let via_method_call = matches!(&e.kind, ExprKind::MethodCall(..) | ExprKind::Call(..));
 
     let left = e.span.shrink_to_lo().until(l_span.shrink_to_lo());
     let middle = l_span.shrink_to_hi().until(r_span.shrink_to_lo());
@@ -376,9 +378,21 @@ fn lint_wide_pointer<'tcx>(
     cx.emit_span_lint(
         AMBIGUOUS_WIDE_POINTER_COMPARISONS,
         e.span,
-        AmbiguousWidePointerComparisons::Spanful {
-            addr_metadata_suggestion: (is_eq_ne && !is_dyn_comparison).then(|| {
-                AmbiguousWidePointerComparisonsAddrMetadataSuggestion {
+        if is_eq_ne {
+            AmbiguousWidePointerComparisons::SpanfulEq {
+                addr_metadata_suggestion: (!is_dyn_comparison).then(|| {
+                    AmbiguousWidePointerComparisonsAddrMetadataSuggestion {
+                        ne,
+                        deref_left,
+                        deref_right,
+                        l_modifiers,
+                        r_modifiers,
+                        left,
+                        middle,
+                        right,
+                    }
+                }),
+                addr_suggestion: AmbiguousWidePointerComparisonsAddrSuggestion {
                     ne,
                     deref_left,
                     deref_right,
@@ -387,21 +401,11 @@ fn lint_wide_pointer<'tcx>(
                     left,
                     middle,
                     right,
-                }
-            }),
-            addr_suggestion: if is_eq_ne {
-                AmbiguousWidePointerComparisonsAddrSuggestion::AddrEq {
-                    ne,
-                    deref_left,
-                    deref_right,
-                    l_modifiers,
-                    r_modifiers,
-                    left,
-                    middle,
-                    right,
-                }
-            } else {
-                AmbiguousWidePointerComparisonsAddrSuggestion::Cast {
+                },
+            }
+        } else {
+            AmbiguousWidePointerComparisons::SpanfulCmp {
+                cast_suggestion: AmbiguousWidePointerComparisonsCastSuggestion {
                     deref_left,
                     deref_right,
                     l_modifiers,
@@ -412,8 +416,14 @@ fn lint_wide_pointer<'tcx>(
                     left_after: l_span.shrink_to_hi(),
                     right_before: (r_ty_refs != 0).then_some(r_span.shrink_to_lo()),
                     right_after: r_span.shrink_to_hi(),
-                }
-            },
+                },
+                expect_suggestion: AmbiguousWidePointerComparisonsExpectSuggestion {
+                    paren_left: if via_method_call { "" } else { "(" },
+                    paren_right: if via_method_call { "" } else { ")" },
+                    before: e.span.shrink_to_lo(),
+                    after: e.span.shrink_to_hi(),
+                },
+            }
         },
     );
 }

compiler/rustc_macros/src/query.rs

@@ -51,6 +51,7 @@ impl Parse for Query {
         let key = Pat::parse_single(&arg_content)?;
         arg_content.parse::<Token![:]>()?;
         let arg = arg_content.parse()?;
+        let _ = arg_content.parse::<Option<Token![,]>>()?;
         let result = input.parse()?;
 
         // Parse the query modifiers

compiler/rustc_middle/src/ty/sty.rs

@@ -1882,9 +1882,9 @@ impl<'tcx> Ty<'tcx> {
             // Needs normalization or revealing to determine, so no is the safe answer.
             ty::Alias(..) => false,
 
-            ty::Param(..) | ty::Infer(..) | ty::Error(..) => false,
+            ty::Param(..) | ty::Placeholder(..) | ty::Infer(..) | ty::Error(..) => false,
 
-            ty::Bound(..) | ty::Placeholder(..) => {
+            ty::Bound(..) => {
                 bug!("`is_trivially_pure_clone_copy` applied to unexpected type: {:?}", self);
             }
         }

compiler/rustc_mir_build/src/builder/mod.rs

@@ -66,8 +66,7 @@ pub fn build_mir<'tcx>(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Body<'tcx> {
                 }
             };
 
-            // this must run before MIR dump, because
-            // "not all control paths return a value" is reported here.
+            // Checking liveness after building the THIR ensures there were no typeck errors.
             //
             // maybe move the check to a MIR pass?
             tcx.ensure_ok().check_liveness(def);
@@ -451,10 +450,6 @@ fn construct_fn<'tcx>(
     let span = tcx.def_span(fn_def);
     let fn_id = tcx.local_def_id_to_hir_id(fn_def);
 
-    // The representation of thir for `-Zunpretty=thir-tree` relies on
-    // the entry expression being the last element of `thir.exprs`.
-    assert_eq!(expr.as_usize(), thir.exprs.len() - 1);
-
     // Figure out what primary body this item has.
     let body = tcx.hir_body_owned_by(fn_def);
     let span_with_body = tcx.hir_span_with_body(fn_id);

compiler/rustc_mir_build/src/thir/cx/mod.rs

@@ -27,8 +27,8 @@ pub(crate) fn thir_body(
     if let Some(reported) = cx.typeck_results.tainted_by_errors {
         return Err(reported);
     }
-    let expr = cx.mirror_expr(body.value);
 
+    // Lower the params before the body's expression so errors from params are shown first.
     let owner_id = tcx.local_def_id_to_hir_id(owner_def);
     if let Some(fn_decl) = tcx.hir_fn_decl_by_hir_id(owner_id) {
         let closure_env_param = cx.closure_env_param(owner_def, owner_id);
@@ -48,6 +48,7 @@ pub(crate) fn thir_body(
         }
     }
 
+    let expr = cx.mirror_expr(body.value);
     Ok((tcx.alloc_steal_thir(cx.thir), expr))
 }
 

compiler/rustc_mir_build/src/thir/print.rs

@@ -8,10 +8,10 @@ use rustc_span::def_id::LocalDefId;
 /// Create a THIR tree for debugging.
 pub fn thir_tree(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
     match super::cx::thir_body(tcx, owner_def) {
-        Ok((thir, _)) => {
+        Ok((thir, expr)) => {
             let thir = thir.steal();
             let mut printer = ThirPrinter::new(&thir);
-            printer.print();
+            printer.print(expr);
             printer.into_buffer()
         }
         Err(_) => "error".into(),
@@ -58,7 +58,7 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
         }
     }
 
-    fn print(&mut self) {
+    fn print(&mut self, body_expr: ExprId) {
         print_indented!(self, "params: [", 0);
         for param in self.thir.params.iter() {
             self.print_param(param, 1);
@@ -66,8 +66,7 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
         print_indented!(self, "]", 0);
 
         print_indented!(self, "body:", 0);
-        let expr = ExprId::from_usize(self.thir.exprs.len() - 1);
-        self.print_expr(expr, 1);
+        self.print_expr(body_expr, 1);
     }
 
     fn into_buffer(self) -> String {

compiler/rustc_mir_transform/src/check_unnecessary_transmutes.rs

@@ -9,6 +9,7 @@ use crate::errors::UnnecessaryTransmute as Error;
 
 /// Check for transmutes that overlap with stdlib methods.
 /// For example, transmuting `[u8; 4]` to `u32`.
+/// We chose not to lint u8 -> bool transmutes, see #140431
 pub(super) struct CheckUnnecessaryTransmutes;
 
 impl<'tcx> crate::MirLint<'tcx> for CheckUnnecessaryTransmutes {
@@ -98,8 +99,6 @@ impl<'a, 'tcx> UnnecessaryTransmuteChecker<'a, 'tcx> {
             (Uint(_), Float(ty)) => err(format!("{}::from_bits({arg})", ty.name_str())),
             // bool → { x8 }
             (Bool, Int(..) | Uint(..)) => err(format!("({arg}) as {}", fn_sig.output())),
-            // u8 → bool
-            (Uint(_), Bool) => err(format!("({arg} == 1)")),
             _ => return None,
         })
     }

compiler/rustc_mir_transform/src/elaborate_drop.rs

@@ -251,7 +251,29 @@ where
                     span_bug!(span, "invalid `AsyncDrop` impl_source: {:?}", impl_source);
                 }
             };
-            let drop_fn_def_id = tcx.associated_item_def_ids(drop_trait)[0];
+            // impl_item_refs may be empty if drop fn is not implemented in 'impl AsyncDrop for ...'
+            // (#140974).
+            // Such code will report error, so just generate sync drop here and return
+            let Some(drop_fn_def_id) =
+                tcx.associated_item_def_ids(drop_trait).into_iter().nth(0).copied()
+            else {
+                tcx.dcx().span_delayed_bug(
+                    self.elaborator.body().span,
+                    "AsyncDrop type without correct `async fn drop(...)`.",
+                );
+                self.elaborator.patch().patch_terminator(
+                    pin_obj_bb,
+                    TerminatorKind::Drop {
+                        place,
+                        target: succ,
+                        unwind: unwind.into_action(),
+                        replace: false,
+                        drop: None,
+                        async_fut: None,
+                    },
+                );
+                return pin_obj_bb;
+            };
             let drop_fn = Ty::new_fn_def(tcx, drop_fn_def_id, trait_args);
             let sig = drop_fn.fn_sig(tcx);
             let sig = tcx.instantiate_bound_regions_with_erased(sig);
@@ -318,15 +340,20 @@ where
                 bug!();
             };
             let obj_ptr_ty = Ty::new_mut_ptr(tcx, drop_ty);
-            let obj_ptr_place = Place::from(self.new_temp(obj_ptr_ty));
             let unwrap_ty = adt_def.non_enum_variant().fields[FieldIdx::ZERO].ty(tcx, adt_args);
-            let addr = Rvalue::RawPtr(
-                RawPtrKind::Mut,
-                pin_obj_place.project_deeper(
-                    &[ProjectionElem::Field(FieldIdx::ZERO, unwrap_ty), ProjectionElem::Deref],
-                    tcx,
-                ),
-            );
+            let obj_ref_place = Place::from(self.new_temp(unwrap_ty));
+            call_statements.push(self.assign(
+                obj_ref_place,
+                Rvalue::Use(Operand::Copy(tcx.mk_place_field(
+                    pin_obj_place,
+                    FieldIdx::ZERO,
+                    unwrap_ty,
+                ))),
+            ));
+
+            let obj_ptr_place = Place::from(self.new_temp(obj_ptr_ty));
+
+            let addr = Rvalue::RawPtr(RawPtrKind::Mut, tcx.mk_place_deref(obj_ref_place));
             call_statements.push(self.assign(obj_ptr_place, addr));
             obj_ptr_place
         };

compiler/rustc_next_trait_solver/src/delegate.rs

@@ -3,6 +3,8 @@ use std::ops::Deref;
 use rustc_type_ir::solve::{Certainty, Goal, NoSolution};
 use rustc_type_ir::{self as ty, InferCtxtLike, Interner, TypeFoldable};
 
+use crate::solve::HasChanged;
+
 pub trait SolverDelegate: Deref<Target = Self::Infcx> + Sized {
     type Infcx: InferCtxtLike<Interner = Self::Interner>;
     type Interner: Interner;
@@ -17,6 +19,12 @@ pub trait SolverDelegate: Deref<Target = Self::Infcx> + Sized {
     where
         V: TypeFoldable<Self::Interner>;
 
+    fn compute_goal_fast_path(
+        &self,
+        goal: Goal<Self::Interner, <Self::Interner as Interner>::Predicate>,
+        span: <Self::Interner as Interner>::Span,
+    ) -> Option<HasChanged>;
+
     fn fresh_var_for_kind_with_span(
         &self,
         arg: <Self::Interner as Interner>::GenericArg,

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs

@@ -12,6 +12,7 @@
 use std::iter;
 
 use rustc_index::IndexVec;
+use rustc_type_ir::data_structures::HashSet;
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::relate::solver_relating::RelateExt;
 use rustc_type_ir::{
@@ -158,10 +159,12 @@ where
             self.compute_external_query_constraints(certainty, normalization_nested_goals);
         let (var_values, mut external_constraints) = (self.var_values, external_constraints)
             .fold_with(&mut EagerResolver::new(self.delegate));
-        // Remove any trivial region constraints once we've resolved regions
-        external_constraints
-            .region_constraints
-            .retain(|outlives| outlives.0.as_region().is_none_or(|re| re != outlives.1));
+
+        // Remove any trivial or duplicated region constraints once we've resolved regions
+        let mut unique = HashSet::default();
+        external_constraints.region_constraints.retain(|outlives| {
+            outlives.0.as_region().is_none_or(|re| re != outlives.1) && unique.insert(*outlives)
+        });
 
         let canonical = Canonicalizer::canonicalize_response(
             self.delegate,

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

@@ -603,6 +603,14 @@ where
         // If this loop did not result in any progress, what's our final certainty.
         let mut unchanged_certainty = Some(Certainty::Yes);
         for (source, goal) in mem::take(&mut self.nested_goals) {
+            if let Some(has_changed) = self.delegate.compute_goal_fast_path(goal, self.origin_span)
+            {
+                if matches!(has_changed, HasChanged::Yes) {
+                    unchanged_certainty = None;
+                }
+                continue;
+            }
+
             // We treat normalizes-to goals specially here. In each iteration we take the
             // RHS of the projection, replace it with a fresh inference variable, and only
             // after evaluating that goal do we equate the fresh inference variable with the

compiler/rustc_next_trait_solver/src/solve/trait_goals.rs

@@ -9,7 +9,7 @@ use rustc_type_ir::{
     self as ty, Interner, Movability, TraitPredicate, TypeVisitableExt as _, TypingMode,
     Upcast as _, elaborate,
 };
-use tracing::{instrument, trace};
+use tracing::{debug, instrument, trace};
 
 use crate::delegate::SolverDelegate;
 use crate::solve::assembly::structural_traits::{self, AsyncCallableRelevantTypes};
@@ -17,7 +17,7 @@ use crate::solve::assembly::{self, AllowInferenceConstraints, AssembleCandidates
 use crate::solve::inspect::ProbeKind;
 use crate::solve::{
     BuiltinImplSource, CandidateSource, Certainty, EvalCtxt, Goal, GoalSource, MaybeCause,
-    NoSolution, ParamEnvSource, QueryResult,
+    NoSolution, ParamEnvSource, QueryResult, has_only_region_constraints,
 };
 
 impl<D, I> assembly::GoalKind<D> for TraitPredicate<I>
@@ -1253,6 +1253,45 @@ where
     D: SolverDelegate<Interner = I>,
     I: Interner,
 {
+    /// FIXME(#57893): For backwards compatability with the old trait solver implementation,
+    /// we need to handle overlap between builtin and user-written impls for trait objects.
+    ///
+    /// This overlap is unsound in general and something which we intend to fix separately.
+    /// To avoid blocking the stabilization of the trait solver, we add this hack to avoid
+    /// breakage in cases which are *mostly fine*™. Importantly, this preference is strictly
+    /// weaker than the old behavior.
+    ///
+    /// We only prefer builtin over user-written impls if there are no inference constraints.
+    /// Importantly, we also only prefer the builtin impls for trait goals, and not during
+    /// normalization. This means the only case where this special-case results in exploitable
+    /// unsoundness should be lifetime dependent user-written impls.
+    pub(super) fn unsound_prefer_builtin_dyn_impl(&mut self, candidates: &mut Vec<Candidate<I>>) {
+        match self.typing_mode() {
+            TypingMode::Coherence => return,
+            TypingMode::Analysis { .. }
+            | TypingMode::Borrowck { .. }
+            | TypingMode::PostBorrowckAnalysis { .. }
+            | TypingMode::PostAnalysis => {}
+        }
+
+        if candidates
+            .iter()
+            .find(|c| {
+                matches!(c.source, CandidateSource::BuiltinImpl(BuiltinImplSource::Object(_)))
+            })
+            .is_some_and(|c| has_only_region_constraints(c.result))
+        {
+            candidates.retain(|c| {
+                if matches!(c.source, CandidateSource::Impl(_)) {
+                    debug!(?c, "unsoundly dropping impl in favor of builtin dyn-candidate");
+                    false
+                } else {
+                    true
+                }
+            });
+        }
+    }
+
     #[instrument(level = "debug", skip(self), ret)]
     pub(super) fn merge_trait_candidates(
         &mut self,
@@ -1313,6 +1352,7 @@ where
         }
 
         self.filter_specialized_impls(AllowInferenceConstraints::No, &mut candidates);
+        self.unsound_prefer_builtin_dyn_impl(&mut candidates);
 
         // If there are *only* global where bounds, then make sure to return that this
         // is still reported as being proven-via the param-env so that rigid projections

compiler/rustc_passes/src/liveness.rs

@@ -122,7 +122,6 @@ enum LiveNodeKind {
     VarDefNode(Span, HirId),
     ClosureNode,
     ExitNode,
-    ErrNode,
 }
 
 fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
@@ -133,7 +132,6 @@ fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
         VarDefNode(s, _) => format!("Var def node [{}]", sm.span_to_diagnostic_string(s)),
         ClosureNode => "Closure node".to_owned(),
         ExitNode => "Exit node".to_owned(),
-        ErrNode => "Error node".to_owned(),
     }
 }
 
@@ -492,6 +490,9 @@ struct Liveness<'a, 'tcx> {
 impl<'a, 'tcx> Liveness<'a, 'tcx> {
     fn new(ir: &'a mut IrMaps<'tcx>, body_owner: LocalDefId) -> Liveness<'a, 'tcx> {
         let typeck_results = ir.tcx.typeck(body_owner);
+        // Liveness linting runs after building the THIR. We make several assumptions based on
+        // typeck succeeding, e.g. that breaks and continues are well-formed.
+        assert!(typeck_results.tainted_by_errors.is_none());
         // FIXME(#132279): we're in a body here.
         let typing_env = ty::TypingEnv::non_body_analysis(ir.tcx, body_owner);
         let closure_min_captures = typeck_results.closure_min_captures.get(&body_owner);
@@ -976,8 +977,9 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 // Now that we know the label we're going to,
                 // look it up in the continue loop nodes table
                 self.cont_ln.get(&sc).cloned().unwrap_or_else(|| {
-                    self.ir.tcx.dcx().span_delayed_bug(expr.span, "continue to unknown label");
-                    self.ir.add_live_node(ErrNode)
+                    // Liveness linting happens after building the THIR. Bad labels should already
+                    // have been caught.
+                    span_bug!(expr.span, "continue to unknown label");
                 })
             }
 

compiler/rustc_resolve/src/late.rs

@@ -3901,7 +3901,9 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         // We walk the pattern before declaring the pattern's inner bindings,
         // so that we avoid resolving a literal expression to a binding defined
         // by the pattern.
-        visit::walk_pat(self, pat);
+        // NB: `Self::visit_pat` must be used rather than `visit::walk_pat` to avoid resolving guard
+        // patterns' guard expressions multiple times (#141265).
+        self.visit_pat(pat);
         self.resolve_pattern_inner(pat, pat_src, bindings);
         // This has to happen *after* we determine which pat_idents are variants:
         self.check_consistent_bindings(pat);

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -11,6 +11,7 @@ use rustc_ast::{
     Item, ItemKind, MethodCall, NodeId, Path, PathSegment, Ty, TyKind,
 };
 use rustc_ast_pretty::pprust::where_bound_predicate_to_string;
+use rustc_attr_parsing::is_doc_alias_attrs_contain_symbol;
 use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_errors::codes::*;
 use rustc_errors::{
@@ -39,7 +40,7 @@ use crate::late::{
 };
 use crate::ty::fast_reject::SimplifiedType;
 use crate::{
-    Module, ModuleKind, ModuleOrUniformRoot, PathResult, PathSource, Segment, errors,
+    Module, ModuleKind, ModuleOrUniformRoot, PathResult, PathSource, Resolver, Segment, errors,
     path_names_to_string,
 };
 
@@ -477,6 +478,19 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             return (err, Vec::new());
         }
 
+        if let Some((did, item)) = self.lookup_doc_alias_name(path, source.namespace()) {
+            let item_name = item.name;
+            let suggestion_name = self.r.tcx.item_name(did);
+            err.span_suggestion(
+                item.span,
+                format!("`{suggestion_name}` has a name defined in the doc alias attribute as `{item_name}`"),
+                    suggestion_name,
+                    Applicability::MaybeIncorrect
+                );
+
+            return (err, Vec::new());
+        };
+
         let (found, suggested_candidates, mut candidates) = self.try_lookup_name_relaxed(
             &mut err,
             source,
@@ -751,12 +765,24 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 match candidate {
                     AssocSuggestion::Field(field_span) => {
                         if self_is_available {
-                            err.span_suggestion_verbose(
-                                span.shrink_to_lo(),
-                                "you might have meant to use the available field",
-                                format!("{pre}self."),
-                                Applicability::MachineApplicable,
-                            );
+                            let source_map = self.r.tcx.sess.source_map();
+                            // check if the field is used in a format string, such as `"{x}"`
+                            let field_is_format_named_arg = source_map
+                                .span_to_source(span, |s, start, _| {
+                                    Ok(s.get(start - 1..start) == Some("{"))
+                                });
+                            if let Ok(true) = field_is_format_named_arg {
+                                err.help(
+                                    format!("you might have meant to use the available field in a format string: `\"{{}}\", self.{}`", segment.ident.name),
+                                );
+                            } else {
+                                err.span_suggestion_verbose(
+                                    span.shrink_to_lo(),
+                                    "you might have meant to use the available field",
+                                    format!("{pre}self."),
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
                         } else {
                             err.span_label(field_span, "a field by that name exists in `Self`");
                         }
@@ -852,6 +878,65 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         (false, suggested_candidates, candidates)
     }
 
+    fn lookup_doc_alias_name(&mut self, path: &[Segment], ns: Namespace) -> Option<(DefId, Ident)> {
+        let find_doc_alias_name = |r: &mut Resolver<'ra, '_>, m: Module<'ra>, item_name: Symbol| {
+            for resolution in r.resolutions(m).borrow().values() {
+                let Some(did) =
+                    resolution.borrow().binding.and_then(|binding| binding.res().opt_def_id())
+                else {
+                    continue;
+                };
+                if did.is_local() {
+                    // We don't record the doc alias name in the local crate
+                    // because the people who write doc alias are usually not
+                    // confused by them.
+                    continue;
+                }
+                if is_doc_alias_attrs_contain_symbol(r.tcx.get_attrs(did, sym::doc), item_name) {
+                    return Some(did);
+                }
+            }
+            None
+        };
+
+        if path.len() == 1 {
+            for rib in self.ribs[ns].iter().rev() {
+                let item = path[0].ident;
+                if let RibKind::Module(module) = rib.kind
+                    && let Some(did) = find_doc_alias_name(self.r, module, item.name)
+                {
+                    return Some((did, item));
+                }
+            }
+        } else {
+            // Finds to the last resolved module item in the path
+            // and searches doc aliases within that module.
+            //
+            // Example: For the path `a::b::last_resolved::not_exist::c::d`,
+            // we will try to find any item has doc aliases named `not_exist`
+            // in `last_resolved` module.
+            //
+            // - Use `skip(1)` because the final segment must remain unresolved.
+            for (idx, seg) in path.iter().enumerate().rev().skip(1) {
+                let Some(id) = seg.id else {
+                    continue;
+                };
+                let Some(res) = self.r.partial_res_map.get(&id) else {
+                    continue;
+                };
+                if let Res::Def(DefKind::Mod, module) = res.expect_full_res()
+                    && let Some(module) = self.r.get_module(module)
+                    && let item = path[idx + 1].ident
+                    && let Some(did) = find_doc_alias_name(self.r, module, item.name)
+                {
+                    return Some((did, item));
+                }
+                break;
+            }
+        }
+        None
+    }
+
     fn suggest_trait_and_bounds(
         &mut self,
         err: &mut Diag<'_>,

compiler/rustc_span/src/analyze_source_file.rs

@@ -29,7 +29,7 @@ pub(crate) fn analyze_source_file(src: &str) -> (Vec<RelativeBytePos>, Vec<Multi
     (lines, multi_byte_chars)
 }
 
-cfg_match! {
+cfg_select! {
     any(target_arch = "x86", target_arch = "x86_64") => {
         fn analyze_source_file_dispatch(
             src: &str,

compiler/rustc_span/src/lib.rs

@@ -20,7 +20,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(core_io_borrowed_buf)]
 #![feature(hash_set_entry)]
 #![feature(if_let_guard)]

compiler/rustc_span/src/symbol.rs

@@ -2592,7 +2592,8 @@ impl Symbol {
     /// (`token_to_string`, `Ident::to_string`), except that symbols don't keep the rawness flag
     /// or edition, so we have to guess the rawness using the global edition.
     pub fn to_ident_string(self) -> String {
-        Ident::with_dummy_span(self).to_string()
+        // Avoid creating an empty identifier, because that asserts in debug builds.
+        if self == kw::Empty { String::new() } else { Ident::with_dummy_span(self).to_string() }
     }
 }
 

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -2124,16 +2124,19 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                         accessed through a specific `impl`",
                     self.tcx.def_kind_descr(assoc_item.as_def_kind(), item_def_id)
                 ));
-                err.span_suggestion(
-                    span,
-                    "use the fully qualified path to an implementation",
-                    format!(
-                        "<Type as {}>::{}",
-                        self.tcx.def_path_str(trait_ref),
-                        assoc_item.name()
-                    ),
-                    Applicability::HasPlaceholders,
-                );
+
+                if !assoc_item.is_impl_trait_in_trait() {
+                    err.span_suggestion(
+                        span,
+                        "use the fully qualified path to an implementation",
+                        format!(
+                            "<Type as {}>::{}",
+                            self.tcx.def_path_str(trait_ref),
+                            assoc_item.name()
+                        ),
+                        Applicability::HasPlaceholders,
+                    );
+                }
             }
         }
     }

compiler/rustc_trait_selection/src/solve/delegate.rs

@@ -1,19 +1,21 @@
 use std::ops::Deref;
 
 use rustc_data_structures::fx::FxHashSet;
+use rustc_hir::LangItem;
 use rustc_hir::def_id::{CRATE_DEF_ID, DefId};
 use rustc_infer::infer::canonical::query_response::make_query_region_constraints;
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalExt as _, CanonicalQueryInput, CanonicalVarInfo, CanonicalVarValues,
 };
-use rustc_infer::infer::{InferCtxt, RegionVariableOrigin, TyCtxtInferExt};
+use rustc_infer::infer::{InferCtxt, RegionVariableOrigin, SubregionOrigin, TyCtxtInferExt};
 use rustc_infer::traits::solve::Goal;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::traits::solve::Certainty;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeVisitableExt as _, TypingMode};
+use rustc_next_trait_solver::solve::HasChanged;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span};
 
-use crate::traits::{EvaluateConstErr, specialization_graph};
+use crate::traits::{EvaluateConstErr, ObligationCause, specialization_graph};
 
 #[repr(transparent)]
 pub struct SolverDelegate<'tcx>(InferCtxt<'tcx>);
@@ -55,6 +57,52 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         (SolverDelegate(infcx), value, vars)
     }
 
+    fn compute_goal_fast_path(
+        &self,
+        goal: Goal<'tcx, ty::Predicate<'tcx>>,
+        span: Span,
+    ) -> Option<HasChanged> {
+        let pred = goal.predicate.kind();
+        match pred.no_bound_vars()? {
+            ty::PredicateKind::DynCompatible(def_id) if self.0.tcx.is_dyn_compatible(def_id) => {
+                Some(HasChanged::No)
+            }
+            ty::PredicateKind::Clause(ty::ClauseKind::RegionOutlives(outlives)) => {
+                self.0.sub_regions(
+                    SubregionOrigin::RelateRegionParamBound(span, None),
+                    outlives.1,
+                    outlives.0,
+                );
+                Some(HasChanged::No)
+            }
+            ty::PredicateKind::Clause(ty::ClauseKind::TypeOutlives(outlives)) => {
+                self.0.register_region_obligation_with_cause(
+                    outlives.0,
+                    outlives.1,
+                    &ObligationCause::dummy_with_span(span),
+                );
+
+                Some(HasChanged::No)
+            }
+            ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_pred)) => {
+                match self.0.tcx.as_lang_item(trait_pred.def_id()) {
+                    Some(LangItem::Sized)
+                        if trait_pred.self_ty().is_trivially_sized(self.0.tcx) =>
+                    {
+                        Some(HasChanged::No)
+                    }
+                    Some(LangItem::Copy | LangItem::Clone)
+                        if trait_pred.self_ty().is_trivially_pure_clone_copy() =>
+                    {
+                        Some(HasChanged::No)
+                    }
+                    _ => None,
+                }
+            }
+            _ => None,
+        }
+    }
+
     fn fresh_var_for_kind_with_span(
         &self,
         arg: ty::GenericArg<'tcx>,

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -12,6 +12,7 @@ use rustc_infer::traits::{
 use rustc_middle::ty::{
     self, DelayedSet, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, TypingMode,
 };
+use rustc_next_trait_solver::delegate::SolverDelegate as _;
 use rustc_next_trait_solver::solve::{GenerateProofTree, HasChanged, SolverDelegateEvalExt as _};
 use rustc_span::Span;
 use tracing::instrument;
@@ -172,7 +173,15 @@ where
                 }
 
                 let goal = obligation.as_goal();
-                let result = <&SolverDelegate<'tcx>>::from(infcx)
+                let delegate = <&SolverDelegate<'tcx>>::from(infcx);
+                if let Some(fast_path_has_changed) =
+                    delegate.compute_goal_fast_path(goal, obligation.cause.span)
+                {
+                    has_changed |= matches!(fast_path_has_changed, HasChanged::Yes);
+                    continue;
+                }
+
+                let result = delegate
                     .evaluate_root_goal(goal, GenerateProofTree::No, obligation.cause.span)
                     .0;
                 self.inspect_evaluated_obligation(infcx, &obligation, &result);

compiler/rustc_trait_selection/src/traits/engine.rs

@@ -188,6 +188,20 @@ where
             .map(|infer_ok| self.register_infer_ok_obligations(infer_ok))
     }
 
+    /// Computes the least-upper-bound, or mutual supertype, of two values.
+    pub fn lub<T: ToTrace<'tcx>>(
+        &self,
+        cause: &ObligationCause<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+        expected: T,
+        actual: T,
+    ) -> Result<T, TypeError<'tcx>> {
+        self.infcx
+            .at(cause, param_env)
+            .lub(expected, actual)
+            .map(|infer_ok| self.register_infer_ok_obligations(infer_ok))
+    }
+
     #[must_use]
     pub fn select_where_possible(&self) -> Vec<E> {
         self.engine.borrow_mut().select_where_possible(self.infcx)

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -340,7 +340,7 @@ pub fn normalize_param_env_or_error<'tcx>(
     let mut predicates: Vec<_> = util::elaborate(
         tcx,
         unnormalized_env.caller_bounds().into_iter().map(|predicate| {
-            if tcx.features().generic_const_exprs() {
+            if tcx.features().generic_const_exprs() || tcx.next_trait_solver_globally() {
                 return predicate;
             }
 
@@ -405,8 +405,6 @@ pub fn normalize_param_env_or_error<'tcx>(
             // compatibility. Eventually when lazy norm is implemented this can just be removed.
             // We do not normalize types here as there is no backwards compatibility requirement
             // for us to do so.
-            //
-            // FIXME(-Znext-solver): remove this hack since we have deferred projection equality
             predicate.fold_with(&mut ConstNormalizer(tcx))
         }),
     )

compiler/rustc_trait_selection/src/traits/normalize.rs

@@ -299,12 +299,21 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> {
             );
         }
 
+        // We don't replace bound vars in the generic arguments of the free alias with
+        // placeholders. This doesn't cause any issues as instantiating parameters with
+        // bound variables is special-cased to rewrite the debruijn index to be higher
+        // whenever we fold through a binder.
+        //
+        // However, we do replace any escaping bound vars in the resulting goals with
+        // placeholders as the trait solver does not expect to encounter escaping bound
+        // vars in obligations.
+        //
+        // FIXME(lazy_type_alias): Check how much this actually matters for perf before
+        // stabilization. This is a bit weird and generally not how we handle binders in
+        // the compiler so ideally we'd do the same boundvar->placeholder->boundvar dance
+        // that other kinds of normalization do.
         let infcx = self.selcx.infcx;
         self.obligations.extend(
-            // FIXME(BoxyUwU):
-            // FIXME(lazy_type_alias):
-            // It seems suspicious to instantiate the predicates with arguments that might be bound vars,
-            // we might wind up instantiating one of these bound vars underneath a hrtb.
             infcx.tcx.predicates_of(free.def_id).instantiate_own(infcx.tcx, free.args).map(
                 |(mut predicate, span)| {
                     if free.has_escaping_bound_vars() {

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -65,71 +65,92 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             let def_id = obligation.predicate.def_id();
             let tcx = self.tcx();
 
-            if tcx.is_lang_item(def_id, LangItem::Copy) {
-                debug!(obligation_self_ty = ?obligation.predicate.skip_binder().self_ty());
+            let lang_item = tcx.as_lang_item(def_id);
+            match lang_item {
+                Some(LangItem::Copy | LangItem::Clone) => {
+                    debug!(obligation_self_ty = ?obligation.predicate.skip_binder().self_ty());
 
-                // User-defined copy impls are permitted, but only for
-                // structs and enums.
-                self.assemble_candidates_from_impls(obligation, &mut candidates);
+                    // User-defined copy impls are permitted, but only for
+                    // structs and enums.
+                    self.assemble_candidates_from_impls(obligation, &mut candidates);
 
-                // For other types, we'll use the builtin rules.
-                let copy_conditions = self.copy_clone_conditions(obligation);
-                self.assemble_builtin_bound_candidates(copy_conditions, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::DiscriminantKind) {
-                // `DiscriminantKind` is automatically implemented for every type.
-                candidates.vec.push(BuiltinCandidate { has_nested: false });
-            } else if tcx.is_lang_item(def_id, LangItem::PointeeTrait) {
-                // `Pointee` is automatically implemented for every type.
-                candidates.vec.push(BuiltinCandidate { has_nested: false });
-            } else if tcx.is_lang_item(def_id, LangItem::Sized) {
-                self.assemble_builtin_sized_candidate(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::Unsize) {
-                self.assemble_candidates_for_unsizing(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::Destruct) {
-                self.assemble_const_destruct_candidates(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::TransmuteTrait) {
-                // User-defined transmutability impls are permitted.
-                self.assemble_candidates_from_impls(obligation, &mut candidates);
-                self.assemble_candidates_for_transmutability(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::Tuple) {
-                self.assemble_candidate_for_tuple(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::FnPtrTrait) {
-                self.assemble_candidates_for_fn_ptr_trait(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::BikeshedGuaranteedNoDrop) {
-                self.assemble_candidates_for_bikeshed_guaranteed_no_drop_trait(
-                    obligation,
-                    &mut candidates,
-                );
-            } else {
-                if tcx.is_lang_item(def_id, LangItem::Clone) {
-                    // Same builtin conditions as `Copy`, i.e., every type which has builtin support
-                    // for `Copy` also has builtin support for `Clone`, and tuples/arrays of `Clone`
-                    // types have builtin support for `Clone`.
-                    let clone_conditions = self.copy_clone_conditions(obligation);
-                    self.assemble_builtin_bound_candidates(clone_conditions, &mut candidates);
+                    // For other types, we'll use the builtin rules.
+                    let copy_conditions = self.copy_clone_conditions(obligation);
+                    self.assemble_builtin_bound_candidates(copy_conditions, &mut candidates);
                 }
-
-                if tcx.is_lang_item(def_id, LangItem::Coroutine) {
-                    self.assemble_coroutine_candidates(obligation, &mut candidates);
-                } else if tcx.is_lang_item(def_id, LangItem::Future) {
-                    self.assemble_future_candidates(obligation, &mut candidates);
-                } else if tcx.is_lang_item(def_id, LangItem::Iterator) {
-                    self.assemble_iterator_candidates(obligation, &mut candidates);
-                } else if tcx.is_lang_item(def_id, LangItem::FusedIterator) {
-                    self.assemble_fused_iterator_candidates(obligation, &mut candidates);
-                } else if tcx.is_lang_item(def_id, LangItem::AsyncIterator) {
-                    self.assemble_async_iterator_candidates(obligation, &mut candidates);
-                } else if tcx.is_lang_item(def_id, LangItem::AsyncFnKindHelper) {
-                    self.assemble_async_fn_kind_helper_candidates(obligation, &mut candidates);
+                Some(LangItem::DiscriminantKind) => {
+                    // `DiscriminantKind` is automatically implemented for every type.
+                    candidates.vec.push(BuiltinCandidate { has_nested: false });
                 }
+                Some(LangItem::PointeeTrait) => {
+                    // `Pointee` is automatically implemented for every type.
+                    candidates.vec.push(BuiltinCandidate { has_nested: false });
+                }
+                Some(LangItem::Sized) => {
+                    self.assemble_builtin_sized_candidate(obligation, &mut candidates);
+                }
+                Some(LangItem::Unsize) => {
+                    self.assemble_candidates_for_unsizing(obligation, &mut candidates);
+                }
+                Some(LangItem::Destruct) => {
+                    self.assemble_const_destruct_candidates(obligation, &mut candidates);
+                }
+                Some(LangItem::TransmuteTrait) => {
+                    // User-defined transmutability impls are permitted.
+                    self.assemble_candidates_from_impls(obligation, &mut candidates);
+                    self.assemble_candidates_for_transmutability(obligation, &mut candidates);
+                }
+                Some(LangItem::Tuple) => {
+                    self.assemble_candidate_for_tuple(obligation, &mut candidates);
+                }
+                Some(LangItem::FnPtrTrait) => {
+                    self.assemble_candidates_for_fn_ptr_trait(obligation, &mut candidates);
+                }
+                Some(LangItem::BikeshedGuaranteedNoDrop) => {
+                    self.assemble_candidates_for_bikeshed_guaranteed_no_drop_trait(
+                        obligation,
+                        &mut candidates,
+                    );
+                }
+                _ => {
+                    // We re-match here for traits that can have both builtin impls and user written impls.
+                    // After the builtin impls we need to also add user written impls, which we do not want to
+                    // do in general because just checking if there are any is expensive.
+                    match lang_item {
+                        Some(LangItem::Coroutine) => {
+                            self.assemble_coroutine_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::Future) => {
+                            self.assemble_future_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::Iterator) => {
+                            self.assemble_iterator_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::FusedIterator) => {
+                            self.assemble_fused_iterator_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::AsyncIterator) => {
+                            self.assemble_async_iterator_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::AsyncFnKindHelper) => {
+                            self.assemble_async_fn_kind_helper_candidates(
+                                obligation,
+                                &mut candidates,
+                            );
+                        }
+                        Some(LangItem::AsyncFn | LangItem::AsyncFnMut | LangItem::AsyncFnOnce) => {
+                            self.assemble_async_closure_candidates(obligation, &mut candidates);
+                        }
+                        Some(LangItem::Fn | LangItem::FnMut | LangItem::FnOnce) => {
+                            self.assemble_closure_candidates(obligation, &mut candidates);
+                            self.assemble_fn_pointer_candidates(obligation, &mut candidates);
+                        }
+                        _ => {}
+                    }
 
-                // FIXME: Put these into `else if` blocks above, since they're built-in.
-                self.assemble_closure_candidates(obligation, &mut candidates);
-                self.assemble_async_closure_candidates(obligation, &mut candidates);
-                self.assemble_fn_pointer_candidates(obligation, &mut candidates);
-
-                self.assemble_candidates_from_impls(obligation, &mut candidates);
-                self.assemble_candidates_from_object_ty(obligation, &mut candidates);
+                    self.assemble_candidates_from_impls(obligation, &mut candidates);
+                    self.assemble_candidates_from_object_ty(obligation, &mut candidates);
+                }
             }
 
             self.assemble_candidates_from_projected_tys(obligation, &mut candidates);
@@ -360,9 +381,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &PolyTraitObligation<'tcx>,
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) {
-        let Some(kind) = self.tcx().fn_trait_kind_from_def_id(obligation.predicate.def_id()) else {
-            return;
-        };
+        let kind = self.tcx().fn_trait_kind_from_def_id(obligation.predicate.def_id()).unwrap();
 
         // Okay to skip binder because the args on closure types never
         // touch bound regions, they just capture the in-scope
@@ -424,11 +443,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &PolyTraitObligation<'tcx>,
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) {
-        let Some(goal_kind) =
-            self.tcx().async_fn_trait_kind_from_def_id(obligation.predicate.def_id())
-        else {
-            return;
-        };
+        let goal_kind =
+            self.tcx().async_fn_trait_kind_from_def_id(obligation.predicate.def_id()).unwrap();
 
         match *obligation.self_ty().skip_binder().kind() {
             ty::CoroutineClosure(_, args) => {
@@ -501,11 +517,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &PolyTraitObligation<'tcx>,
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) {
-        // We provide impl of all fn traits for fn pointers.
-        if !self.tcx().is_fn_trait(obligation.predicate.def_id()) {
-            return;
-        }
-
         // Keep this function in sync with extract_tupled_inputs_and_output_from_callable
         // until the old solver (and thus this function) is removed.
 

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -251,16 +251,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let tcx = self.tcx();
         let obligations = if has_nested {
             let trait_def = obligation.predicate.def_id();
-            let conditions = if tcx.is_lang_item(trait_def, LangItem::Sized) {
-                self.sized_conditions(obligation)
-            } else if tcx.is_lang_item(trait_def, LangItem::Copy) {
-                self.copy_clone_conditions(obligation)
-            } else if tcx.is_lang_item(trait_def, LangItem::Clone) {
-                self.copy_clone_conditions(obligation)
-            } else if tcx.is_lang_item(trait_def, LangItem::FusedIterator) {
-                self.fused_iterator_conditions(obligation)
-            } else {
-                bug!("unexpected builtin trait {:?}", trait_def)
+            let conditions = match tcx.as_lang_item(trait_def) {
+                Some(LangItem::Sized) => self.sized_conditions(obligation),
+                Some(LangItem::Copy | LangItem::Clone) => self.copy_clone_conditions(obligation),
+                Some(LangItem::FusedIterator) => self.fused_iterator_conditions(obligation),
+                other => bug!("unexpected builtin trait {trait_def:?} ({other:?})"),
             };
             let BuiltinImplConditions::Where(types) = conditions else {
                 bug!("obligation {:?} had matched a builtin impl but now doesn't", obligation);

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

@@ -1312,6 +1312,8 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// If [`make_contiguous`] was previously called, all elements of the
     /// deque will be in the first slice and the second slice will be empty.
+    /// Otherwise, the exact split point depends on implementation details
+    /// and is not guaranteed.
     ///
     /// [`make_contiguous`]: VecDeque::make_contiguous
     ///
@@ -1326,12 +1328,18 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// deque.push_back(1);
     /// deque.push_back(2);
     ///
-    /// assert_eq!(deque.as_slices(), (&[0, 1, 2][..], &[][..]));
+    /// let expected = [0, 1, 2];
+    /// let (front, back) = deque.as_slices();
+    /// assert_eq!(&expected[..front.len()], front);
+    /// assert_eq!(&expected[front.len()..], back);
     ///
     /// deque.push_front(10);
     /// deque.push_front(9);
     ///
-    /// assert_eq!(deque.as_slices(), (&[9, 10][..], &[0, 1, 2][..]));
+    /// let expected = [9, 10, 0, 1, 2];
+    /// let (front, back) = deque.as_slices();
+    /// assert_eq!(&expected[..front.len()], front);
+    /// assert_eq!(&expected[front.len()..], back);
     /// ```
     #[inline]
     #[stable(feature = "deque_extras_15", since = "1.5.0")]
@@ -1347,6 +1355,8 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// If [`make_contiguous`] was previously called, all elements of the
     /// deque will be in the first slice and the second slice will be empty.
+    /// Otherwise, the exact split point depends on implementation details
+    /// and is not guaranteed.
     ///
     /// [`make_contiguous`]: VecDeque::make_contiguous
     ///
@@ -1363,9 +1373,22 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// deque.push_front(10);
     /// deque.push_front(9);
     ///
-    /// deque.as_mut_slices().0[0] = 42;
-    /// deque.as_mut_slices().1[0] = 24;
-    /// assert_eq!(deque.as_slices(), (&[42, 10][..], &[24, 1][..]));
+    /// // Since the split point is not guaranteed, we may need to update
+    /// // either slice.
+    /// let mut update_nth = |index: usize, val: u32| {
+    ///     let (front, back) = deque.as_mut_slices();
+    ///     if index > front.len() - 1 {
+    ///         back[index - front.len()] = val;
+    ///     } else {
+    ///         front[index] = val;
+    ///     }
+    /// };
+    ///
+    /// update_nth(0, 42);
+    /// update_nth(2, 24);
+    ///
+    /// let v: Vec<_> = deque.into();
+    /// assert_eq!(v, [42, 10, 24, 1]);
     /// ```
     #[inline]
     #[stable(feature = "deque_extras_15", since = "1.5.0")]

library/alloc/src/slice.rs

@@ -69,7 +69,7 @@ use crate::boxed::Box;
 use crate::vec::Vec;
 
 impl<T> [T] {
-    /// Sorts the slice, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order, preserving initial order of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
@@ -137,7 +137,8 @@ impl<T> [T] {
         stable_sort(self, T::lt);
     }
 
-    /// Sorts the slice with a comparison function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a comparison function, preserving initial order of
+    /// equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
@@ -197,7 +198,8 @@ impl<T> [T] {
         stable_sort(self, |a, b| compare(a, b) == Less);
     }
 
-    /// Sorts the slice with a key extraction function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a key extraction function, preserving initial order
+    /// of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* \* log(*n*))
     /// worst-case, where the key function is *O*(*m*).
@@ -252,7 +254,8 @@ impl<T> [T] {
         stable_sort(self, |a, b| f(a).lt(&f(b)));
     }
 
-    /// Sorts the slice with a key extraction function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a key extraction function, preserving initial order
+    /// of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* + *n* \*
     /// log(*n*)) worst-case, where the key function is *O*(*m*).

library/alloc/src/str.rs

@@ -320,6 +320,7 @@ impl str {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "replace_first")]
     #[must_use = "this returns the replaced string as a new allocation, \
                   without modifying the original"]
     #[stable(feature = "str_replacen", since = "1.16.0")]

library/core/src/ffi/mod.rs

@@ -28,7 +28,7 @@ pub mod c_str;
     issue = "44930",
     reason = "the `c_variadic` feature has not been properly tested on all supported platforms"
 )]
-pub use self::va_list::{VaList, VaListImpl};
+pub use self::va_list::{VaArgSafe, VaList, VaListImpl};
 
 #[unstable(
     feature = "c_variadic",

library/core/src/ffi/primitives.rs

@@ -35,7 +35,7 @@ type_alias! { "c_float.md", c_float = f32; }
 type_alias! { "c_double.md", c_double = f64; }
 
 mod c_char_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         // These are the targets on which c_char is unsigned. Usually the
         // signedness is the same for all target_os values on a given architecture
         // but there are some exceptions (see isSignedCharDefault() in clang).
@@ -133,7 +133,7 @@ mod c_char_definition {
 }
 
 mod c_long_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(
             all(target_pointer_width = "64", not(windows)),
             // wasm32 Linux ABI uses 64-bit long
@@ -172,7 +172,7 @@ pub type c_ptrdiff_t = isize;
 pub type c_ssize_t = isize;
 
 mod c_int_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(target_arch = "avr", target_arch = "msp430") => {
             pub(super) type c_int = i16;
             pub(super) type c_uint = u16;

library/core/src/ffi/va_list.rs

@@ -223,39 +223,57 @@ impl<'a, 'f: 'a> DerefMut for VaList<'a, 'f> {
     }
 }
 
-// The VaArgSafe trait needs to be used in public interfaces, however, the trait
-// itself must not be allowed to be used outside this module. Allowing users to
-// implement the trait for a new type (thereby allowing the va_arg intrinsic to
-// be used on a new type) is likely to cause undefined behavior.
-//
-// FIXME(dlrobertson): In order to use the VaArgSafe trait in a public interface
-// but also ensure it cannot be used elsewhere, the trait needs to be public
-// within a private module. Once RFC 2145 has been implemented look into
-// improving this.
-mod sealed_trait {
-    /// Trait which permits the allowed types to be used with [super::VaListImpl::arg].
-    pub unsafe trait VaArgSafe {}
+mod sealed {
+    pub trait Sealed {}
+
+    impl Sealed for i32 {}
+    impl Sealed for i64 {}
+    impl Sealed for isize {}
+
+    impl Sealed for u32 {}
+    impl Sealed for u64 {}
+    impl Sealed for usize {}
+
+    impl Sealed for f64 {}
+
+    impl<T> Sealed for *mut T {}
+    impl<T> Sealed for *const T {}
 }
 
-macro_rules! impl_va_arg_safe {
-    ($($t:ty),+) => {
-        $(
-            unsafe impl sealed_trait::VaArgSafe for $t {}
-        )+
-    }
-}
+/// Trait which permits the allowed types to be used with [`VaListImpl::arg`].
+///
+/// # Safety
+///
+/// This trait must only be implemented for types that C passes as varargs without implicit promotion.
+///
+/// In C varargs, integers smaller than [`c_int`] and floats smaller than [`c_double`]
+/// are implicitly promoted to [`c_int`] and [`c_double`] respectively. Implementing this trait for
+/// types that are subject to this promotion rule is invalid.
+///
+/// [`c_int`]: core::ffi::c_int
+/// [`c_double`]: core::ffi::c_double
+pub unsafe trait VaArgSafe: sealed::Sealed {}
 
-impl_va_arg_safe! {i8, i16, i32, i64, usize}
-impl_va_arg_safe! {u8, u16, u32, u64, isize}
-impl_va_arg_safe! {f64}
+// i8 and i16 are implicitly promoted to c_int in C, and cannot implement `VaArgSafe`.
+unsafe impl VaArgSafe for i32 {}
+unsafe impl VaArgSafe for i64 {}
+unsafe impl VaArgSafe for isize {}
 
-unsafe impl<T> sealed_trait::VaArgSafe for *mut T {}
-unsafe impl<T> sealed_trait::VaArgSafe for *const T {}
+// u8 and u16 are implicitly promoted to c_int in C, and cannot implement `VaArgSafe`.
+unsafe impl VaArgSafe for u32 {}
+unsafe impl VaArgSafe for u64 {}
+unsafe impl VaArgSafe for usize {}
+
+// f32 is implicitly promoted to c_double in C, and cannot implement `VaArgSafe`.
+unsafe impl VaArgSafe for f64 {}
+
+unsafe impl<T> VaArgSafe for *mut T {}
+unsafe impl<T> VaArgSafe for *const T {}
 
 impl<'f> VaListImpl<'f> {
     /// Advance to the next arg.
     #[inline]
-    pub unsafe fn arg<T: sealed_trait::VaArgSafe>(&mut self) -> T {
+    pub unsafe fn arg<T: VaArgSafe>(&mut self) -> T {
         // SAFETY: the caller must uphold the safety contract for `va_arg`.
         unsafe { va_arg(self) }
     }
@@ -317,4 +335,4 @@ unsafe fn va_copy<'f>(dest: *mut VaListImpl<'f>, src: &VaListImpl<'f>);
 /// argument `ap` points to.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-unsafe fn va_arg<T: sealed_trait::VaArgSafe>(ap: &mut VaListImpl<'_>) -> T;
+unsafe fn va_arg<T: VaArgSafe>(ap: &mut VaListImpl<'_>) -> T;

library/core/src/lib.rs

@@ -100,7 +100,7 @@
 #![feature(bigint_helper_methods)]
 #![feature(bstr)]
 #![feature(bstr_internals)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(cfg_target_has_reliable_f16_f128)]
 #![feature(const_carrying_mul_add)]
 #![feature(const_eval_select)]
@@ -235,8 +235,8 @@ pub mod autodiff {
 #[unstable(feature = "contracts", issue = "128044")]
 pub mod contracts;
 
-#[unstable(feature = "cfg_match", issue = "115585")]
-pub use crate::macros::cfg_match;
+#[unstable(feature = "cfg_select", issue = "115585")]
+pub use crate::macros::cfg_select;
 
 #[macro_use]
 mod internal_macros;

library/core/src/macros/mod.rs

@@ -210,9 +210,9 @@ pub macro assert_matches {
 /// # Example
 ///
 /// ```
-/// #![feature(cfg_match)]
+/// #![feature(cfg_select)]
 ///
-/// cfg_match! {
+/// cfg_select! {
 ///     unix => {
 ///         fn foo() { /* unix specific functionality */ }
 ///     }
@@ -228,19 +228,19 @@ pub macro assert_matches {
 /// If desired, it is possible to return expressions through the use of surrounding braces:
 ///
 /// ```
-/// #![feature(cfg_match)]
+/// #![feature(cfg_select)]
 ///
-/// let _some_string = cfg_match! {{
+/// let _some_string = cfg_select! {{
 ///     unix => { "With great power comes great electricity bills" }
 ///     _ => { "Behind every successful diet is an unwatched pizza" }
 /// }};
 /// ```
-#[unstable(feature = "cfg_match", issue = "115585")]
-#[rustc_diagnostic_item = "cfg_match"]
+#[unstable(feature = "cfg_select", issue = "115585")]
+#[rustc_diagnostic_item = "cfg_select"]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro cfg_match {
+pub macro cfg_select {
     ({ $($tt:tt)* }) => {{
-        $crate::cfg_match! { $($tt)* }
+        $crate::cfg_select! { $($tt)* }
     }},
     (_ => { $($output:tt)* }) => {
         $($output)*
@@ -250,10 +250,10 @@ pub macro cfg_match {
         $($( $rest:tt )+)?
     ) => {
         #[cfg($cfg)]
-        $crate::cfg_match! { _ => $output }
+        $crate::cfg_select! { _ => $output }
         $(
             #[cfg(not($cfg))]
-            $crate::cfg_match! { $($rest)+ }
+            $crate::cfg_select! { $($rest)+ }
         )?
     },
 }

library/core/src/num/f32.rs

@@ -14,7 +14,7 @@
 use crate::convert::FloatToInt;
 use crate::num::FpCategory;
 use crate::panic::const_assert;
-use crate::{cfg_match, intrinsics, mem};
+use crate::{cfg_select, intrinsics, mem};
 
 /// The radix or base of the internal representation of `f32`.
 /// Use [`f32::RADIX`] instead.
@@ -990,7 +990,7 @@ impl f32 {
     #[stable(feature = "num_midpoint", since = "1.85.0")]
     #[rustc_const_stable(feature = "num_midpoint", since = "1.85.0")]
     pub const fn midpoint(self, other: f32) -> f32 {
-        cfg_match! {
+        cfg_select! {
             // Allow faster implementation that have known good 64-bit float
             // implementations. Falling back to the branchy code on targets that don't
             // have 64-bit hardware floats or buggy implementations.

library/core/src/ptr/const_ptr.rs

@@ -66,6 +66,34 @@ impl<T: ?Sized> *const T {
         self as _
     }
 
+    /// Try to cast to a pointer of another type by checking aligment.
+    ///
+    /// If the pointer is properly aligned to the target type, it will be
+    /// cast to the target type. Otherwise, `None` is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// #![feature(pointer_try_cast_aligned)]
+    ///
+    /// let aligned: *const u8 = 0x1000 as _;
+    ///
+    /// // i32 has at most 4-byte alignment, so this will succeed
+    /// assert!(aligned.try_cast_aligned::<i32>().is_some());
+    ///
+    /// let unaligned: *const u8 = 0x1001 as _;
+    ///
+    /// // i32 has at least 2-byte alignment, so this will fail
+    /// assert!(unaligned.try_cast_aligned::<i32>().is_none());
+    /// ```
+    #[unstable(feature = "pointer_try_cast_aligned", issue = "141221")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
+    #[inline]
+    pub fn try_cast_aligned<U>(self) -> Option<*const U> {
+        if self.is_aligned_to(align_of::<U>()) { Some(self.cast()) } else { None }
+    }
+
     /// Uses the address value in a new pointer of another type.
     ///
     /// This operation will ignore the address part of its `meta` operand and discard existing

library/core/src/ptr/mut_ptr.rs

@@ -48,6 +48,34 @@ impl<T: ?Sized> *mut T {
         self as _
     }
 
+    /// Try to cast to a pointer of another type by checking aligment.
+    ///
+    /// If the pointer is properly aligned to the target type, it will be
+    /// cast to the target type. Otherwise, `None` is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// #![feature(pointer_try_cast_aligned)]
+    ///
+    /// let aligned: *mut u8 = 0x1000 as _;
+    ///
+    /// // i32 has at most 4-byte alignment, so this will succeed
+    /// assert!(aligned.try_cast_aligned::<i32>().is_some());
+    ///
+    /// let unaligned: *mut u8 = 0x1001 as _;
+    ///
+    /// // i32 has at least 2-byte alignment, so this will fail
+    /// assert!(unaligned.try_cast_aligned::<i32>().is_none());
+    /// ```
+    #[unstable(feature = "pointer_try_cast_aligned", issue = "141221")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
+    #[inline]
+    pub fn try_cast_aligned<U>(self) -> Option<*mut U> {
+        if self.is_aligned_to(align_of::<U>()) { Some(self.cast()) } else { None }
+    }
+
     /// Uses the address value in a new pointer of another type.
     ///
     /// This operation will ignore the address part of its `meta` operand and discard existing

library/core/src/ptr/non_null.rs

@@ -490,6 +490,35 @@ impl<T: ?Sized> NonNull<T> {
         unsafe { NonNull { pointer: self.as_ptr() as *mut U } }
     }
 
+    /// Try to cast to a pointer of another type by checking aligment.
+    ///
+    /// If the pointer is properly aligned to the target type, it will be
+    /// cast to the target type. Otherwise, `None` is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// #![feature(pointer_try_cast_aligned)]
+    /// use std::ptr::NonNull;
+    ///
+    /// let aligned: NonNull<u8> = NonNull::new(0x1000 as _).unwrap();
+    ///
+    /// // i32 has at most 4-byte alignment, so this will succeed
+    /// assert!(aligned.try_cast_aligned::<i32>().is_some());
+    ///
+    /// let unaligned: NonNull<u8> = NonNull::new(0x1001 as _).unwrap();
+    ///
+    /// // i32 has at least 2-byte alignment, so this will fail
+    /// assert!(unaligned.try_cast_aligned::<i32>().is_none());
+    /// ```
+    #[unstable(feature = "pointer_try_cast_aligned", issue = "141221")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
+    #[inline]
+    pub fn try_cast_aligned<U>(self) -> Option<NonNull<U>> {
+        if self.is_aligned_to(align_of::<U>()) { Some(self.cast()) } else { None }
+    }
+
     /// Adds an offset to a pointer.
     ///
     /// `count` is in units of T; e.g., a `count` of 3 represents a pointer

library/core/src/slice/mod.rs

@@ -2986,7 +2986,7 @@ impl<T> [T] {
         self.binary_search_by(|k| f(k).cmp(b))
     }
 
-    /// Sorts the slice **without** preserving the initial order of equal elements.
+    /// Sorts the slice in ascending order **without** preserving the initial order of equal elements.
     ///
     /// This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not
     /// allocate), and *O*(*n* \* log(*n*)) worst-case.
@@ -3047,8 +3047,8 @@ impl<T> [T] {
         sort::unstable::sort(self, &mut T::lt);
     }
 
-    /// Sorts the slice with a comparison function, **without** preserving the initial order of
-    /// equal elements.
+    /// Sorts the slice in ascending order with a comparison function, **without** preserving the
+    /// initial order of equal elements.
     ///
     /// This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not
     /// allocate), and *O*(*n* \* log(*n*)) worst-case.
@@ -3102,8 +3102,8 @@ impl<T> [T] {
         sort::unstable::sort(self, &mut |a, b| compare(a, b) == Ordering::Less);
     }
 
-    /// Sorts the slice with a key extraction function, **without** preserving the initial order of
-    /// equal elements.
+    /// Sorts the slice in ascending order with a key extraction function, **without** preserving
+    /// the initial order of equal elements.
     ///
     /// This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not
     /// allocate), and *O*(*n* \* log(*n*)) worst-case.

library/core/src/slice/sort/select.rs

@@ -6,7 +6,7 @@
 //! for pivot selection. Using this as a fallback ensures O(n) worst case running time with
 //! better performance than one would get using heapsort as fallback.
 
-use crate::cfg_match;
+use crate::cfg_select;
 use crate::mem::{self, SizedTypeProperties};
 #[cfg(not(feature = "optimize_for_size"))]
 use crate::slice::sort::shared::pivot::choose_pivot;
@@ -42,7 +42,7 @@ where
         let min_idx = min_index(v, &mut is_less).unwrap();
         v.swap(min_idx, index);
     } else {
-        cfg_match! {
+        cfg_select! {
             feature = "optimize_for_size" => {
                 median_of_medians(v, &mut is_less, index);
             }

library/core/src/slice/sort/stable/mod.rs

@@ -7,7 +7,7 @@ use crate::mem::{MaybeUninit, SizedTypeProperties};
 use crate::slice::sort::shared::smallsort::{
     SMALL_SORT_GENERAL_SCRATCH_LEN, StableSmallSortTypeImpl, insertion_sort_shift_left,
 };
-use crate::{cfg_match, intrinsics};
+use crate::{cfg_select, intrinsics};
 
 pub(crate) mod merge;
 
@@ -39,13 +39,13 @@ pub fn sort<T, F: FnMut(&T, &T) -> bool, BufT: BufGuard<T>>(v: &mut [T], is_less
         return;
     }
 
-    cfg_match! {
+    cfg_select! {
         any(feature = "optimize_for_size", target_pointer_width = "16") => {
             // Unlike driftsort, mergesort only requires len / 2,
             // not len - len / 2.
             let alloc_len = len / 2;
 
-            cfg_match! {
+            cfg_select! {
                 target_pointer_width = "16" => {
                     let mut heap_buf = BufT::with_capacity(alloc_len);
                     let scratch = heap_buf.as_uninit_slice_mut();

library/core/src/slice/sort/unstable/mod.rs

@@ -5,7 +5,7 @@ use crate::mem::SizedTypeProperties;
 use crate::slice::sort::shared::find_existing_run;
 #[cfg(not(any(feature = "optimize_for_size", target_pointer_width = "16")))]
 use crate::slice::sort::shared::smallsort::insertion_sort_shift_left;
-use crate::{cfg_match, intrinsics};
+use crate::{cfg_select, intrinsics};
 
 pub(crate) mod heapsort;
 pub(crate) mod quicksort;
@@ -30,7 +30,7 @@ pub fn sort<T, F: FnMut(&T, &T) -> bool>(v: &mut [T], is_less: &mut F) {
         return;
     }
 
-    cfg_match! {
+    cfg_select! {
         any(feature = "optimize_for_size", target_pointer_width = "16") => {
             heapsort::heapsort(v, is_less);
         }

library/core/src/slice/sort/unstable/quicksort.rs

@@ -9,7 +9,7 @@ use crate::slice::sort::shared::pivot::choose_pivot;
 use crate::slice::sort::shared::smallsort::UnstableSmallSortTypeImpl;
 #[cfg(not(feature = "optimize_for_size"))]
 use crate::slice::sort::unstable::heapsort;
-use crate::{cfg_match, intrinsics, ptr};
+use crate::{cfg_select, intrinsics, ptr};
 
 /// Sorts `v` recursively.
 ///
@@ -142,7 +142,7 @@ const fn inst_partition<T, F: FnMut(&T, &T) -> bool>() -> fn(&mut [T], &T, &mut
     if size_of::<T>() <= MAX_BRANCHLESS_PARTITION_SIZE {
         // Specialize for types that are relatively cheap to copy, where branchless optimizations
         // have large leverage e.g. `u64` and `String`.
-        cfg_match! {
+        cfg_select! {
             feature = "optimize_for_size" => {
                 partition_lomuto_branchless_simple::<T, F>
             }

library/coretests/tests/lib.rs

@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
 #![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
-#![cfg_attr(test, feature(cfg_match))]
+#![cfg_attr(test, feature(cfg_select))]
 #![feature(alloc_layout_extra)]
 #![feature(array_chunks)]
 #![feature(array_ptr_get)]

library/coretests/tests/macros.rs

@@ -9,7 +9,7 @@ trait Trait {
 struct Struct;
 
 impl Trait for Struct {
-    cfg_match! {
+    cfg_select! {
         feature = "blah" => {
             fn blah(&self) {
                 unimplemented!();
@@ -45,22 +45,22 @@ fn matches_leading_pipe() {
 }
 
 #[test]
-fn cfg_match_basic() {
-    cfg_match! {
+fn cfg_select_basic() {
+    cfg_select! {
         target_pointer_width = "64" => { fn f0_() -> bool { true }}
     }
 
-    cfg_match! {
+    cfg_select! {
         unix => { fn f1_() -> bool { true } }
         any(target_os = "macos", target_os = "linux") => { fn f1_() -> bool { false }}
     }
 
-    cfg_match! {
+    cfg_select! {
         target_pointer_width = "32" => { fn f2_() -> bool { false } }
         target_pointer_width = "64" => { fn f2_() -> bool { true } }
     }
 
-    cfg_match! {
+    cfg_select! {
         target_pointer_width = "16" => { fn f3_() -> i32 { 1 } }
         _ => { fn f3_() -> i32 { 2 }}
     }
@@ -81,8 +81,8 @@ fn cfg_match_basic() {
 }
 
 #[test]
-fn cfg_match_debug_assertions() {
-    cfg_match! {
+fn cfg_select_debug_assertions() {
+    cfg_select! {
         debug_assertions => {
             assert!(cfg!(debug_assertions));
             assert_eq!(4, 2+2);
@@ -96,8 +96,8 @@ fn cfg_match_debug_assertions() {
 
 #[cfg(target_pointer_width = "64")]
 #[test]
-fn cfg_match_no_duplication_on_64() {
-    cfg_match! {
+fn cfg_select_no_duplication_on_64() {
+    cfg_select! {
         windows => {
             fn foo() {}
         }
@@ -112,8 +112,8 @@ fn cfg_match_no_duplication_on_64() {
 }
 
 #[test]
-fn cfg_match_options() {
-    cfg_match! {
+fn cfg_select_options() {
+    cfg_select! {
         test => {
             use core::option::Option as Option2;
             fn works1() -> Option2<u32> { Some(1) }
@@ -121,25 +121,25 @@ fn cfg_match_options() {
         _ => { fn works1() -> Option<u32> { None } }
     }
 
-    cfg_match! {
+    cfg_select! {
         feature = "foo" => { fn works2() -> bool { false } }
         test => { fn works2() -> bool { true } }
         _ => { fn works2() -> bool { false } }
     }
 
-    cfg_match! {
+    cfg_select! {
         feature = "foo" => { fn works3() -> bool { false } }
         _ => { fn works3() -> bool { true } }
     }
 
-    cfg_match! {
+    cfg_select! {
         test => {
             use core::option::Option as Option3;
             fn works4() -> Option3<u32> { Some(1) }
         }
     }
 
-    cfg_match! {
+    cfg_select! {
         feature = "foo" => { fn works5() -> bool { false } }
         test => { fn works5() -> bool { true } }
     }
@@ -152,8 +152,8 @@ fn cfg_match_options() {
 }
 
 #[test]
-fn cfg_match_two_functions() {
-    cfg_match! {
+fn cfg_select_two_functions() {
+    cfg_select! {
         target_pointer_width = "64" => {
             fn foo1() {}
             fn bar1() {}
@@ -177,7 +177,7 @@ fn cfg_match_two_functions() {
 }
 
 fn _accepts_expressions() -> i32 {
-    cfg_match! {
+    cfg_select! {
         unix => { 1 }
         _ => { 2 }
     }
@@ -188,14 +188,14 @@ fn _accepts_expressions() -> i32 {
 fn _allows_stmt_expr_attributes() {
     let one = 1;
     let two = 2;
-    cfg_match! {
+    cfg_select! {
         unix => { one * two; }
         _ => { one + two; }
     }
 }
 
 fn _expression() {
-    let _ = cfg_match!({
+    let _ = cfg_select!({
         windows => {
             " XP"
         }

library/std/src/ffi/mod.rs

@@ -172,7 +172,7 @@ pub use core::ffi::c_void;
               all supported platforms",
     issue = "44930"
 )]
-pub use core::ffi::{VaList, VaListImpl};
+pub use core::ffi::{VaArgSafe, VaList, VaListImpl};
 #[stable(feature = "core_ffi_c", since = "1.64.0")]
 pub use core::ffi::{
     c_char, c_double, c_float, c_int, c_long, c_longlong, c_schar, c_short, c_uchar, c_uint,

library/std/src/lib.rs

@@ -700,8 +700,8 @@ mod panicking;
 #[allow(dead_code, unused_attributes, fuzzy_provenance_casts, unsafe_op_in_unsafe_fn)]
 mod backtrace_rs;
 
-#[unstable(feature = "cfg_match", issue = "115585")]
-pub use core::cfg_match;
+#[unstable(feature = "cfg_select", issue = "115585")]
+pub use core::cfg_select;
 #[unstable(
     feature = "concat_bytes",
     issue = "87555",

library/std/src/os/unix/process.rs

@@ -8,6 +8,7 @@ use cfg_if::cfg_if;
 
 use crate::ffi::OsStr;
 use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::path::Path;
 use crate::sealed::Sealed;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 use crate::{io, process, sys};
@@ -197,6 +198,18 @@ pub trait CommandExt: Sealed {
     /// ```
     #[stable(feature = "process_set_process_group", since = "1.64.0")]
     fn process_group(&mut self, pgroup: i32) -> &mut process::Command;
+
+    /// Set the root of the child process. This calls `chroot` in the child process before executing
+    /// the command.
+    ///
+    /// This happens before changing to the directory specified with
+    /// [`process::Command::current_dir`], and that directory will be relative to the new root.
+    ///
+    /// If no directory has been specified with [`process::Command::current_dir`], this will set the
+    /// directory to `/`, to avoid leaving the current directory outside the chroot. (This is an
+    /// intentional difference from the underlying `chroot` system call.)
+    #[unstable(feature = "process_chroot", issue = "141298")]
+    fn chroot<P: AsRef<Path>>(&mut self, dir: P) -> &mut process::Command;
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -242,6 +255,11 @@ impl CommandExt for process::Command {
         self.as_inner_mut().pgroup(pgroup);
         self
     }
+
+    fn chroot<P: AsRef<Path>>(&mut self, dir: P) -> &mut process::Command {
+        self.as_inner_mut().chroot(dir.as_ref());
+        self
+    }
 }
 
 /// Unix-specific extensions to [`process::ExitStatus`] and

library/std/src/sys/process/unix/common.rs

@@ -88,6 +88,7 @@ pub struct Command {
 
     program_kind: ProgramKind,
     cwd: Option<CString>,
+    chroot: Option<CString>,
     uid: Option<uid_t>,
     gid: Option<gid_t>,
     saw_nul: bool,
@@ -182,6 +183,7 @@ impl Command {
             program_kind,
             env: Default::default(),
             cwd: None,
+            chroot: None,
             uid: None,
             gid: None,
             saw_nul,
@@ -206,6 +208,7 @@ impl Command {
             program_kind,
             env: Default::default(),
             cwd: None,
+            chroot: None,
             uid: None,
             gid: None,
             saw_nul,
@@ -254,6 +257,12 @@ impl Command {
     pub fn pgroup(&mut self, pgroup: pid_t) {
         self.pgroup = Some(pgroup);
     }
+    pub fn chroot(&mut self, dir: &Path) {
+        self.chroot = Some(os2c(dir.as_os_str(), &mut self.saw_nul));
+        if self.cwd.is_none() {
+            self.cwd(&OsStr::new("/"));
+        }
+    }
 
     #[cfg(target_os = "linux")]
     pub fn create_pidfd(&mut self, val: bool) {
@@ -326,6 +335,10 @@ impl Command {
     pub fn get_pgroup(&self) -> Option<pid_t> {
         self.pgroup
     }
+    #[allow(dead_code)]
+    pub fn get_chroot(&self) -> Option<&CStr> {
+        self.chroot.as_deref()
+    }
 
     pub fn get_closures(&mut self) -> &mut Vec<Box<dyn FnMut() -> io::Result<()> + Send + Sync>> {
         &mut self.closures

library/std/src/sys/process/unix/unix.rs

@@ -323,6 +323,15 @@ impl Command {
                 cvt(libc::setuid(u as uid_t))?;
             }
         }
+        if let Some(chroot) = self.get_chroot() {
+            #[cfg(not(target_os = "fuchsia"))]
+            cvt(libc::chroot(chroot.as_ptr()))?;
+            #[cfg(target_os = "fuchsia")]
+            return Err(io::const_error!(
+                io::ErrorKind::Unsupported,
+                "chroot not supported by fuchsia"
+            ));
+        }
         if let Some(cwd) = self.get_cwd() {
             cvt(libc::chdir(cwd.as_ptr()))?;
         }
@@ -447,6 +456,7 @@ impl Command {
             || (self.env_saw_path() && !self.program_is_path())
             || !self.get_closures().is_empty()
             || self.get_groups().is_some()
+            || self.get_chroot().is_some()
         {
             return Ok(None);
         }

library/std/src/sys/process/unix/vxworks.rs

@@ -27,6 +27,12 @@ impl Command {
                 "nul byte found in provided data",
             ));
         }
+        if self.get_chroot().is_some() {
+            return Err(io::const_error!(
+                ErrorKind::Unsupported,
+                "chroot not supported by vxworks",
+            ));
+        }
         let (ours, theirs) = self.setup_io(default, needs_stdin)?;
         let mut p = Process { pid: 0, status: None };
 

library/stdarch

@@ -1 +1 @@
-Subproject commit 1dfaa4db2479753a46a3e90f2c3c89d89d0b21f1
+Subproject commit b6e2249e388f520627544812649b77b0944e1a2e

src/bootstrap/Cargo.lock

@@ -89,9 +89,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.17"
+version = "1.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fcb57c740ae1daf453ae85f16e37396f672b039e00d9d866e07ddb24e328e3a"
+checksum = "5f4ac86a9e5bc1e2b3449ab9d7d3a6a405e3d1bb28d7b9be8614f55846ae3766"
 dependencies = [
  "shlex",
 ]

src/bootstrap/Cargo.toml

@@ -32,7 +32,7 @@ test = false
 # Most of the time updating these dependencies requires modifications to the
 # bootstrap codebase(e.g., https://github.com/rust-lang/rust/issues/124565);
 # otherwise, some targets will fail. That's why these dependencies are explicitly pinned.
-cc = "=1.2.17"
+cc = "=1.2.23"
 cmake = "=0.1.54"
 
 build_helper = { path = "../build_helper" }

src/bootstrap/src/core/build_steps/perf.rs

@@ -1,3 +1,4 @@
+use std::env::consts::EXE_EXTENSION;
 use std::fmt::{Display, Formatter};
 
 use crate::core::build_steps::compile::{Std, Sysroot};
@@ -160,7 +161,10 @@ Consider setting `rust.debuginfo-level = 1` in `bootstrap.toml`."#);
     }
 
     let sysroot = builder.ensure(Sysroot::new(compiler));
-    let rustc = sysroot.join("bin/rustc");
+    let mut rustc = sysroot.clone();
+    rustc.push("bin");
+    rustc.push("rustc");
+    rustc.set_extension(EXE_EXTENSION);
 
     let rustc_perf_dir = builder.build.tempdir().join("rustc-perf");
     let results_dir = rustc_perf_dir.join("results");

src/bootstrap/src/utils/cc_detect.rs

@@ -22,43 +22,13 @@
 //! everything.
 
 use std::collections::HashSet;
+use std::iter;
 use std::path::{Path, PathBuf};
-use std::{env, iter};
 
 use crate::core::config::TargetSelection;
 use crate::utils::exec::{BootstrapCommand, command};
 use crate::{Build, CLang, GitRepo};
 
-/// Finds archiver tool for the given target if possible.
-/// FIXME(onur-ozkan): This logic should be replaced by calling into the `cc` crate.
-fn cc2ar(cc: &Path, target: TargetSelection, default_ar: PathBuf) -> Option<PathBuf> {
-    if let Some(ar) = env::var_os(format!("AR_{}", target.triple.replace('-', "_"))) {
-        Some(PathBuf::from(ar))
-    } else if let Some(ar) = env::var_os("AR") {
-        Some(PathBuf::from(ar))
-    } else if target.is_msvc() {
-        None
-    } else if target.contains("musl") || target.contains("openbsd") {
-        Some(PathBuf::from("ar"))
-    } else if target.contains("vxworks") {
-        Some(PathBuf::from("wr-ar"))
-    } else if target.contains("-nto-") {
-        if target.starts_with("i586") {
-            Some(PathBuf::from("ntox86-ar"))
-        } else if target.starts_with("aarch64") {
-            Some(PathBuf::from("ntoaarch64-ar"))
-        } else if target.starts_with("x86_64") {
-            Some(PathBuf::from("ntox86_64-ar"))
-        } else {
-            panic!("Unknown architecture, cannot determine archiver for Neutrino QNX");
-        }
-    } else if target.contains("android") || target.contains("-wasi") {
-        Some(cc.parent().unwrap().join(PathBuf::from("llvm-ar")))
-    } else {
-        Some(default_ar)
-    }
-}
-
 /// Creates and configures a new [`cc::Build`] instance for the given target.
 fn new_cc_build(build: &Build, target: TargetSelection) -> cc::Build {
     let mut cfg = cc::Build::new();
@@ -140,7 +110,7 @@ pub fn find_target(build: &Build, target: TargetSelection) {
     let ar = if let ar @ Some(..) = config.and_then(|c| c.ar.clone()) {
         ar
     } else {
-        cc2ar(compiler.path(), target, PathBuf::from(cfg.get_archiver().get_program()))
+        cfg.try_get_archiver().map(|c| PathBuf::from(c.get_program())).ok()
     };
 
     build.cc.borrow_mut().insert(target, compiler.clone());

src/bootstrap/src/utils/cc_detect/tests.rs

@@ -5,119 +5,6 @@ use super::*;
 use crate::core::config::{Target, TargetSelection};
 use crate::{Build, Config, Flags};
 
-#[test]
-fn test_cc2ar_env_specific() {
-    let triple = "x86_64-unknown-linux-gnu";
-    let key = "AR_x86_64_unknown_linux_gnu";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::set_var(key, "custom-ar") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var(key) };
-    assert_eq!(result, Some(PathBuf::from("custom-ar")));
-}
-
-#[test]
-fn test_cc2ar_musl() {
-    let triple = "x86_64-unknown-linux-musl";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_x86_64_unknown_linux_musl") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("ar")));
-}
-
-#[test]
-fn test_cc2ar_openbsd() {
-    let triple = "x86_64-unknown-openbsd";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_x86_64_unknown_openbsd") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/cc");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("ar")));
-}
-
-#[test]
-fn test_cc2ar_vxworks() {
-    let triple = "armv7-wrs-vxworks";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_armv7_wrs_vxworks") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("wr-ar")));
-}
-
-#[test]
-fn test_cc2ar_nto_i586() {
-    let triple = "i586-unknown-nto-something";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_i586_unknown_nto_something") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("ntox86-ar")));
-}
-
-#[test]
-fn test_cc2ar_nto_aarch64() {
-    let triple = "aarch64-unknown-nto-something";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_aarch64_unknown_nto_something") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("ntoaarch64-ar")));
-}
-
-#[test]
-fn test_cc2ar_nto_x86_64() {
-    let triple = "x86_64-unknown-nto-something";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_x86_64_unknown_nto_something") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let result = cc2ar(cc, target, default_ar);
-    assert_eq!(result, Some(PathBuf::from("ntox86_64-ar")));
-}
-
-#[test]
-#[should_panic(expected = "Unknown architecture, cannot determine archiver for Neutrino QNX")]
-fn test_cc2ar_nto_unknown() {
-    let triple = "powerpc-unknown-nto-something";
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR_powerpc_unknown_nto_something") };
-    // SAFETY: bootstrap tests run on a single thread
-    unsafe { env::remove_var("AR") };
-    let target = TargetSelection::from_user(triple);
-    let cc = Path::new("/usr/bin/clang");
-    let default_ar = PathBuf::from("default-ar");
-    let _ = cc2ar(cc, target, default_ar);
-}
-
 #[test]
 fn test_ndk_compiler_c() {
     let ndk_path = PathBuf::from("/ndk");

src/ci/docker/host-x86_64/arm-android/Dockerfile

@@ -28,6 +28,7 @@ RUN /scripts/android-sdk.sh
 ENV PATH=$PATH:/android/sdk/emulator
 ENV PATH=$PATH:/android/sdk/tools
 ENV PATH=$PATH:/android/sdk/platform-tools
+ENV PATH=$PATH:/android/ndk/toolchains/llvm/prebuilt/linux-x86_64/bin
 
 ENV TARGETS=arm-linux-androideabi
 

src/ci/docker/host-x86_64/dist-android/Dockerfile

@@ -22,6 +22,8 @@ ENV RUST_CONFIGURE_ARGS \
       --android-ndk=/android/ndk/ \
       --disable-docs
 
+ENV PATH=$PATH:/android/ndk/toolchains/llvm/prebuilt/linux-x86_64/bin
+
 ENV SCRIPT python3 ../x.py dist --host='' --target $TARGETS
 
 COPY scripts/sccache.sh /scripts/

src/ci/docker/host-x86_64/dist-arm-linux-gnueabi/Dockerfile

@@ -0,0 +1,35 @@
+FROM ghcr.io/rust-lang/ubuntu:22.04
+
+COPY scripts/cross-apt-packages.sh /scripts/
+RUN sh /scripts/cross-apt-packages.sh
+
+COPY scripts/crosstool-ng.sh /scripts/
+RUN sh /scripts/crosstool-ng.sh
+
+WORKDIR /build
+
+COPY scripts/rustbuild-setup.sh /scripts/
+RUN sh /scripts/rustbuild-setup.sh
+WORKDIR /tmp
+
+COPY scripts/crosstool-ng-build.sh /scripts/
+COPY host-x86_64/dist-arm-linux-gnueabi/arm-linux-gnueabi.defconfig /tmp/crosstool.defconfig
+RUN /scripts/crosstool-ng-build.sh
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+ENV PATH=$PATH:/x-tools/arm-unknown-linux-gnueabi/bin
+
+ENV CC_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-gcc \
+    AR_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-ar \
+    CXX_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-g++
+
+ENV HOSTS=arm-unknown-linux-gnueabi
+
+ENV RUST_CONFIGURE_ARGS \
+      --enable-full-tools \
+      --disable-docs \
+      --enable-sanitizers \
+      --enable-profiler
+ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS

src/ci/docker/host-x86_64/dist-arm-linux-musl/Dockerfile

@@ -19,19 +19,13 @@ RUN sh /scripts/rustbuild-setup.sh
 WORKDIR /tmp
 
 COPY scripts/crosstool-ng-build.sh /scripts/
-COPY host-x86_64/dist-arm-linux/arm-linux-gnueabi.defconfig /tmp/crosstool.defconfig
+COPY host-x86_64/dist-arm-linux-musl/arm-linux-musl.defconfig /tmp/crosstool.defconfig
 RUN /scripts/crosstool-ng-build.sh
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
-ENV PATH=$PATH:/x-tools/arm-unknown-linux-gnueabi/bin
-
-ENV CC_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-gcc \
-    AR_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-ar \
-    CXX_arm_unknown_linux_gnueabi=arm-unknown-linux-gnueabi-g++
-
-ENV HOSTS=arm-unknown-linux-gnueabi,aarch64-unknown-linux-musl
+ENV HOSTS=aarch64-unknown-linux-musl
 
 ENV RUST_CONFIGURE_ARGS \
       --enable-full-tools \

src/ci/docker/host-x86_64/dist-arm-linux-musl/arm-linux-musl.defconfig

@@ -0,0 +1,13 @@
+CT_CONFIG_VERSION="4"
+CT_PREFIX_DIR="/x-tools/${CT_TARGET}"
+CT_USE_MIRROR=y
+CT_MIRROR_BASE_URL="https://ci-mirrors.rust-lang.org/rustc"
+CT_ARCH_ARM=y
+CT_ARCH_ARCH="armv6"
+CT_ARCH_FLOAT_SW=y
+CT_KERNEL_LINUX=y
+CT_LINUX_V_3_2=y
+CT_BINUTILS_V_2_32=y
+CT_GLIBC_V_2_17=y
+CT_GCC_V_8=y
+CT_CC_LANG_CXX=y

src/ci/docker/host-x86_64/dist-powerpc64le-linux-gnu/Dockerfile

@@ -0,0 +1,41 @@
+FROM ubuntu:22.04
+
+COPY scripts/cross-apt-packages.sh /scripts/
+RUN sh /scripts/cross-apt-packages.sh
+
+COPY scripts/crosstool-ng.sh /scripts/
+RUN sh /scripts/crosstool-ng.sh
+
+COPY scripts/rustbuild-setup.sh /scripts/
+RUN sh /scripts/rustbuild-setup.sh
+
+WORKDIR /tmp
+
+COPY scripts/crosstool-ng-build.sh /scripts/
+COPY host-x86_64/dist-powerpc64le-linux-gnu/powerpc64le-unknown-linux-gnu.defconfig /tmp/crosstool.defconfig
+RUN /scripts/crosstool-ng-build.sh
+
+WORKDIR /build
+
+RUN apt-get install -y --no-install-recommends rpm2cpio cpio
+COPY scripts/shared.sh scripts/build-powerpc64le-toolchain.sh /build/
+RUN ./build-powerpc64le-toolchain.sh
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+ENV \
+    AR_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-ar \
+    CC_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-gcc \
+    CXX_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-g++
+
+ENV HOSTS=powerpc64le-unknown-linux-gnu
+
+ENV RUST_CONFIGURE_ARGS \
+    --enable-extended \
+    --enable-full-tools \
+    --enable-profiler \
+    --enable-sanitizers \
+    --disable-docs
+
+ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS

src/ci/docker/host-x86_64/dist-powerpc64le-linux-gnu/powerpc64le-unknown-linux-gnu.defconfig

@@ -0,0 +1,14 @@
+CT_CONFIG_VERSION="4"
+CT_EXPERIMENTAL=y
+CT_PREFIX_DIR="/x-tools/${CT_TARGET}"
+CT_USE_MIRROR=y
+CT_MIRROR_BASE_URL="https://ci-mirrors.rust-lang.org/rustc"
+CT_ARCH_POWERPC=y
+CT_ARCH_LE=y
+CT_ARCH_64=y
+# CT_DEMULTILIB is not set
+CT_ARCH_ARCH="powerpc64le"
+CT_KERNEL_LINUX=y
+CT_LINUX_V_4_19=y
+CT_CC_LANG_CXX=y
+CT_GETTEXT_NEEDED=y

src/ci/docker/host-x86_64/dist-powerpc64le-linux-musl/Dockerfile

@@ -12,13 +12,13 @@ RUN sh /scripts/rustbuild-setup.sh
 WORKDIR /tmp
 
 COPY scripts/crosstool-ng-build.sh /scripts/
-COPY host-x86_64/dist-powerpc64le-linux/powerpc64le-unknown-linux-musl.defconfig /tmp/crosstool.defconfig
+COPY host-x86_64/dist-powerpc64le-linux-musl/powerpc64le-unknown-linux-musl.defconfig /tmp/crosstool.defconfig
 RUN /scripts/crosstool-ng-build.sh
 
 WORKDIR /build
 
 RUN apt-get install -y --no-install-recommends rpm2cpio cpio
-COPY scripts/shared.sh host-x86_64/dist-powerpc64le-linux/build-powerpc64le-toolchain.sh /build/
+COPY scripts/shared.sh scripts/build-powerpc64le-toolchain.sh /build/
 RUN ./build-powerpc64le-toolchain.sh
 
 COPY scripts/sccache.sh /scripts/
@@ -27,14 +27,11 @@ RUN sh /scripts/sccache.sh
 ENV PATH=$PATH:/x-tools/powerpc64le-unknown-linux-musl/bin
 
 ENV \
-    AR_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-ar \
-    CC_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-gcc \
-    CXX_powerpc64le_unknown_linux_gnu=powerpc64le-linux-gnu-g++ \
     AR_powerpc64le_unknown_linux_musl=powerpc64le-unknown-linux-musl-ar \
     CC_powerpc64le_unknown_linux_musl=powerpc64le-unknown-linux-musl-gcc \
     CXX_powerpc64le_unknown_linux_musl=powerpc64le-unknown-linux-musl-g++
 
-ENV HOSTS=powerpc64le-unknown-linux-gnu,powerpc64le-unknown-linux-musl
+ENV HOSTS=powerpc64le-unknown-linux-musl
 
 ENV RUST_CONFIGURE_ARGS \
     --enable-extended \

src/ci/docker/run.sh

@@ -97,9 +97,8 @@ if [ -f "$docker_dir/$image/Dockerfile" ]; then
     docker --version
 
     REGISTRY=ghcr.io
-    # Hardcode username to reuse cache between auto and pr jobs
-    # FIXME: should be changed after move from rust-lang-ci
-    REGISTRY_USERNAME=rust-lang-ci
+    # Default to `rust-lang` to allow reusing the cache for local builds
+    REGISTRY_USERNAME=${GITHUB_REPOSITORY_OWNER:-rust-lang}
     # Tag used to push the final Docker image, so that it can be pulled by e.g. rustup
     IMAGE_TAG=${REGISTRY}/${REGISTRY_USERNAME}/rust-ci:${cksum}
     # Tag used to cache the Docker build

src/ci/github-actions/jobs.yml

@@ -10,11 +10,6 @@ runners:
     free_disk: true
     <<: *base-job
 
-  # Large runner used mainly for its bigger disk capacity
-  - &job-linux-4c-largedisk
-    os: ubuntu-24.04-4core-16gb
-    <<: *base-job
-
   - &job-linux-8c
     os: ubuntu-24.04-8core-32gb
     <<: *base-job
@@ -167,8 +162,11 @@ auto:
   - name: dist-android
     <<: *job-linux-4c
 
-  - name: dist-arm-linux
-    <<: *job-linux-8c-codebuild
+  - name: dist-arm-linux-gnueabi
+    <<: *job-linux-4c
+
+  - name: dist-arm-linux-musl
+    <<: *job-linux-4c
 
   - name: dist-armhf-linux
     <<: *job-linux-4c
@@ -203,8 +201,11 @@ auto:
   - name: dist-powerpc64-linux
     <<: *job-linux-4c
 
-  - name: dist-powerpc64le-linux
-    <<: *job-linux-4c-largedisk
+  - name: dist-powerpc64le-linux-gnu
+    <<: *job-linux-4c
+
+  - name: dist-powerpc64le-linux-musl
+    <<: *job-linux-4c
 
   - name: dist-riscv64-linux
     <<: *job-linux-4c

src/doc/edition-guide

@@ -1 +1 @@
-Subproject commit 1b1bb49babd65c732468cfa515b0c009bd1d26bc
+Subproject commit aa6ce337c0adf7a63e33960d184270f2a45ab9ef

src/doc/reference

@@ -1 +1 @@
-Subproject commit acd0231ebc74849f6a8907b5e646ce86721aad76
+Subproject commit 118fd1f1f0854f50e3ae1fe4b64862aad23009ca

src/librustdoc/doctest.rs

@@ -12,7 +12,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::{Arc, Mutex};
 use std::{panic, str};
 
-pub(crate) use make::DocTestBuilder;
+pub(crate) use make::{BuildDocTestBuilder, DocTestBuilder};
 pub(crate) use markdown::test as test_markdown;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
 use rustc_errors::emitter::HumanReadableErrorType;
@@ -23,9 +23,9 @@ use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_interface::interface;
 use rustc_session::config::{self, CrateType, ErrorOutputType, Input};
 use rustc_session::lint;
-use rustc_span::FileName;
 use rustc_span::edition::Edition;
 use rustc_span::symbol::sym;
+use rustc_span::{FileName, Span};
 use rustc_target::spec::{Target, TargetTuple};
 use tempfile::{Builder as TempFileBuilder, TempDir};
 use tracing::debug;
@@ -197,7 +197,7 @@ pub(crate) fn run(dcx: DiagCtxtHandle<'_>, input: Input, options: RustdocOptions
                 }
             } else {
                 let mut collector = CreateRunnableDocTests::new(options, opts);
-                tests.into_iter().for_each(|t| collector.add_test(t));
+                tests.into_iter().for_each(|t| collector.add_test(t, Some(compiler.sess.dcx())));
 
                 Ok(Some(collector))
             }
@@ -847,6 +847,7 @@ pub(crate) struct ScrapedDocTest {
     langstr: LangString,
     text: String,
     name: String,
+    span: Span,
 }
 
 impl ScrapedDocTest {
@@ -856,6 +857,7 @@ impl ScrapedDocTest {
         logical_path: Vec<String>,
         langstr: LangString,
         text: String,
+        span: Span,
     ) -> Self {
         let mut item_path = logical_path.join("::");
         item_path.retain(|c| c != ' ');
@@ -865,7 +867,7 @@ impl ScrapedDocTest {
         let name =
             format!("{} - {item_path}(line {line})", filename.prefer_remapped_unconditionaly());
 
-        Self { filename, line, langstr, text, name }
+        Self { filename, line, langstr, text, name, span }
     }
     fn edition(&self, opts: &RustdocOptions) -> Edition {
         self.langstr.edition.unwrap_or(opts.edition)
@@ -921,7 +923,7 @@ impl CreateRunnableDocTests {
         }
     }
 
-    fn add_test(&mut self, scraped_test: ScrapedDocTest) {
+    fn add_test(&mut self, scraped_test: ScrapedDocTest, dcx: Option<DiagCtxtHandle<'_>>) {
         // For example `module/file.rs` would become `module_file_rs`
         let file = scraped_test
             .filename
@@ -945,14 +947,14 @@ impl CreateRunnableDocTests {
         );
 
         let edition = scraped_test.edition(&self.rustdoc_options);
-        let doctest = DocTestBuilder::new(
-            &scraped_test.text,
-            Some(&self.opts.crate_name),
-            edition,
-            self.can_merge_doctests,
-            Some(test_id),
-            Some(&scraped_test.langstr),
-        );
+        let doctest = BuildDocTestBuilder::new(&scraped_test.text)
+            .crate_name(&self.opts.crate_name)
+            .edition(edition)
+            .can_merge_doctests(self.can_merge_doctests)
+            .test_id(test_id)
+            .lang_str(&scraped_test.langstr)
+            .span(scraped_test.span)
+            .build(dcx);
         let is_standalone = !doctest.can_be_merged
             || scraped_test.langstr.compile_fail
             || scraped_test.langstr.test_harness

src/librustdoc/doctest/extracted.rs

@@ -5,7 +5,7 @@
 
 use serde::Serialize;
 
-use super::{DocTestBuilder, ScrapedDocTest};
+use super::{BuildDocTestBuilder, ScrapedDocTest};
 use crate::config::Options as RustdocOptions;
 use crate::html::markdown;
 
@@ -35,16 +35,13 @@ impl ExtractedDocTests {
     ) {
         let edition = scraped_test.edition(options);
 
-        let ScrapedDocTest { filename, line, langstr, text, name } = scraped_test;
+        let ScrapedDocTest { filename, line, langstr, text, name, .. } = scraped_test;
 
-        let doctest = DocTestBuilder::new(
-            &text,
-            Some(&opts.crate_name),
-            edition,
-            false,
-            None,
-            Some(&langstr),
-        );
+        let doctest = BuildDocTestBuilder::new(&text)
+            .crate_name(&opts.crate_name)
+            .edition(edition)
+            .lang_str(&langstr)
+            .build(None);
         let (full_test_code, size) = doctest.generate_unique_doctest(
             &text,
             langstr.test_harness,

src/librustdoc/doctest/make.rs

@@ -8,14 +8,14 @@ use std::sync::Arc;
 use rustc_ast::token::{Delimiter, TokenKind};
 use rustc_ast::tokenstream::TokenTree;
 use rustc_ast::{self as ast, AttrStyle, HasAttrs, StmtKind};
-use rustc_errors::ColorConfig;
 use rustc_errors::emitter::stderr_destination;
+use rustc_errors::{ColorConfig, DiagCtxtHandle};
 use rustc_parse::new_parser_from_source_str;
 use rustc_session::parse::ParseSess;
-use rustc_span::edition::Edition;
+use rustc_span::edition::{DEFAULT_EDITION, Edition};
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::sym;
-use rustc_span::{FileName, kw};
+use rustc_span::{DUMMY_SP, FileName, Span, kw};
 use tracing::debug;
 
 use super::GlobalTestOptions;
@@ -35,6 +35,138 @@ struct ParseSourceInfo {
     maybe_crate_attrs: String,
 }
 
+/// Builder type for `DocTestBuilder`.
+pub(crate) struct BuildDocTestBuilder<'a> {
+    source: &'a str,
+    crate_name: Option<&'a str>,
+    edition: Edition,
+    can_merge_doctests: bool,
+    // If `test_id` is `None`, it means we're generating code for a code example "run" link.
+    test_id: Option<String>,
+    lang_str: Option<&'a LangString>,
+    span: Span,
+}
+
+impl<'a> BuildDocTestBuilder<'a> {
+    pub(crate) fn new(source: &'a str) -> Self {
+        Self {
+            source,
+            crate_name: None,
+            edition: DEFAULT_EDITION,
+            can_merge_doctests: false,
+            test_id: None,
+            lang_str: None,
+            span: DUMMY_SP,
+        }
+    }
+
+    #[inline]
+    pub(crate) fn crate_name(mut self, crate_name: &'a str) -> Self {
+        self.crate_name = Some(crate_name);
+        self
+    }
+
+    #[inline]
+    pub(crate) fn can_merge_doctests(mut self, can_merge_doctests: bool) -> Self {
+        self.can_merge_doctests = can_merge_doctests;
+        self
+    }
+
+    #[inline]
+    pub(crate) fn test_id(mut self, test_id: String) -> Self {
+        self.test_id = Some(test_id);
+        self
+    }
+
+    #[inline]
+    pub(crate) fn lang_str(mut self, lang_str: &'a LangString) -> Self {
+        self.lang_str = Some(lang_str);
+        self
+    }
+
+    #[inline]
+    pub(crate) fn span(mut self, span: Span) -> Self {
+        self.span = span;
+        self
+    }
+
+    #[inline]
+    pub(crate) fn edition(mut self, edition: Edition) -> Self {
+        self.edition = edition;
+        self
+    }
+
+    pub(crate) fn build(self, dcx: Option<DiagCtxtHandle<'_>>) -> DocTestBuilder {
+        let BuildDocTestBuilder {
+            source,
+            crate_name,
+            edition,
+            can_merge_doctests,
+            // If `test_id` is `None`, it means we're generating code for a code example "run" link.
+            test_id,
+            lang_str,
+            span,
+        } = self;
+        let can_merge_doctests = can_merge_doctests
+            && lang_str.is_some_and(|lang_str| {
+                !lang_str.compile_fail && !lang_str.test_harness && !lang_str.standalone_crate
+            });
+
+        let result = rustc_driver::catch_fatal_errors(|| {
+            rustc_span::create_session_if_not_set_then(edition, |_| {
+                parse_source(source, &crate_name, dcx, span)
+            })
+        });
+
+        let Ok(Ok(ParseSourceInfo {
+            has_main_fn,
+            already_has_extern_crate,
+            supports_color,
+            has_global_allocator,
+            has_macro_def,
+            everything_else,
+            crates,
+            crate_attrs,
+            maybe_crate_attrs,
+        })) = result
+        else {
+            // If the AST returned an error, we don't want this doctest to be merged with the
+            // others.
+            return DocTestBuilder::invalid(
+                String::new(),
+                String::new(),
+                String::new(),
+                source.to_string(),
+                test_id,
+            );
+        };
+
+        debug!("crate_attrs:\n{crate_attrs}{maybe_crate_attrs}");
+        debug!("crates:\n{crates}");
+        debug!("after:\n{everything_else}");
+
+        // If it contains `#[feature]` or `#[no_std]`, we don't want it to be merged either.
+        let can_be_merged = can_merge_doctests
+            && !has_global_allocator
+            && crate_attrs.is_empty()
+            // If this is a merged doctest and a defined macro uses `$crate`, then the path will
+            // not work, so better not put it into merged doctests.
+            && !(has_macro_def && everything_else.contains("$crate"));
+        DocTestBuilder {
+            supports_color,
+            has_main_fn,
+            crate_attrs,
+            maybe_crate_attrs,
+            crates,
+            everything_else,
+            already_has_extern_crate,
+            test_id,
+            invalid_ast: false,
+            can_be_merged,
+        }
+    }
+}
+
 /// This struct contains information about the doctest itself which is then used to generate
 /// doctest source code appropriately.
 pub(crate) struct DocTestBuilder {
@@ -53,74 +185,6 @@ pub(crate) struct DocTestBuilder {
 }
 
 impl DocTestBuilder {
-    pub(crate) fn new(
-        source: &str,
-        crate_name: Option<&str>,
-        edition: Edition,
-        can_merge_doctests: bool,
-        // If `test_id` is `None`, it means we're generating code for a code example "run" link.
-        test_id: Option<String>,
-        lang_str: Option<&LangString>,
-    ) -> Self {
-        let can_merge_doctests = can_merge_doctests
-            && lang_str.is_some_and(|lang_str| {
-                !lang_str.compile_fail && !lang_str.test_harness && !lang_str.standalone_crate
-            });
-
-        let result = rustc_driver::catch_fatal_errors(|| {
-            rustc_span::create_session_if_not_set_then(edition, |_| {
-                parse_source(source, &crate_name)
-            })
-        });
-
-        let Ok(Ok(ParseSourceInfo {
-            has_main_fn,
-            already_has_extern_crate,
-            supports_color,
-            has_global_allocator,
-            has_macro_def,
-            everything_else,
-            crates,
-            crate_attrs,
-            maybe_crate_attrs,
-        })) = result
-        else {
-            // If the AST returned an error, we don't want this doctest to be merged with the
-            // others.
-            return Self::invalid(
-                String::new(),
-                String::new(),
-                String::new(),
-                source.to_string(),
-                test_id,
-            );
-        };
-
-        debug!("crate_attrs:\n{crate_attrs}{maybe_crate_attrs}");
-        debug!("crates:\n{crates}");
-        debug!("after:\n{everything_else}");
-
-        // If it contains `#[feature]` or `#[no_std]`, we don't want it to be merged either.
-        let can_be_merged = can_merge_doctests
-            && !has_global_allocator
-            && crate_attrs.is_empty()
-            // If this is a merged doctest and a defined macro uses `$crate`, then the path will
-            // not work, so better not put it into merged doctests.
-            && !(has_macro_def && everything_else.contains("$crate"));
-        Self {
-            supports_color,
-            has_main_fn,
-            crate_attrs,
-            maybe_crate_attrs,
-            crates,
-            everything_else,
-            already_has_extern_crate,
-            test_id,
-            invalid_ast: false,
-            can_be_merged,
-        }
-    }
-
     fn invalid(
         crate_attrs: String,
         maybe_crate_attrs: String,
@@ -289,7 +353,12 @@ fn reset_error_count(psess: &ParseSess) {
 
 const DOCTEST_CODE_WRAPPER: &str = "fn f(){";
 
-fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceInfo, ()> {
+fn parse_source(
+    source: &str,
+    crate_name: &Option<&str>,
+    parent_dcx: Option<DiagCtxtHandle<'_>>,
+    span: Span,
+) -> Result<ParseSourceInfo, ()> {
     use rustc_errors::DiagCtxt;
     use rustc_errors::emitter::{Emitter, HumanEmitter};
     use rustc_span::source_map::FilePathMapping;
@@ -466,8 +535,17 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
                 }
             }
             if has_non_items {
-                // FIXME: if `info.has_main_fn` is `true`, emit a warning here to mention that
-                // this code will not be called.
+                if info.has_main_fn
+                    && let Some(dcx) = parent_dcx
+                    && !span.is_dummy()
+                {
+                    dcx.span_warn(
+                        span,
+                        "the `main` function of this doctest won't be run as it contains \
+                         expressions at the top level, meaning that the whole doctest code will be \
+                         wrapped in a function",
+                    );
+                }
                 info.has_main_fn = false;
             }
             Ok(info)

src/librustdoc/doctest/markdown.rs

@@ -4,7 +4,7 @@ use std::fs::read_to_string;
 use std::sync::{Arc, Mutex};
 
 use rustc_session::config::Input;
-use rustc_span::FileName;
+use rustc_span::{DUMMY_SP, FileName};
 use tempfile::tempdir;
 
 use super::{
@@ -24,7 +24,14 @@ impl DocTestVisitor for MdCollector {
         let filename = self.filename.clone();
         // First line of Markdown is line 1.
         let line = 1 + rel_line.offset();
-        self.tests.push(ScrapedDocTest::new(filename, line, self.cur_path.clone(), config, test));
+        self.tests.push(ScrapedDocTest::new(
+            filename,
+            line,
+            self.cur_path.clone(),
+            config,
+            test,
+            DUMMY_SP,
+        ));
     }
 
     fn visit_header(&mut self, name: &str, level: u32) {
@@ -107,7 +114,7 @@ pub(crate) fn test(input: &Input, options: Options) -> Result<(), String> {
     find_testable_code(&input_str, &mut md_collector, codes, None);
 
     let mut collector = CreateRunnableDocTests::new(options.clone(), opts);
-    md_collector.tests.into_iter().for_each(|t| collector.add_test(t));
+    md_collector.tests.into_iter().for_each(|t| collector.add_test(t, None));
     let CreateRunnableDocTests { opts, rustdoc_options, standalone_tests, mergeable_tests, .. } =
         collector;
     crate::doctest::run_tests(

src/librustdoc/doctest/rust.rs

@@ -1,5 +1,6 @@
 //! Doctest functionality used only for doctests in `.rs` source files.
 
+use std::cell::Cell;
 use std::env;
 use std::sync::Arc;
 
@@ -47,13 +48,33 @@ impl RustCollector {
 
 impl DocTestVisitor for RustCollector {
     fn visit_test(&mut self, test: String, config: LangString, rel_line: MdRelLine) {
-        let line = self.get_base_line() + rel_line.offset();
+        let base_line = self.get_base_line();
+        let line = base_line + rel_line.offset();
+        let count = Cell::new(base_line);
+        let span = if line > base_line {
+            match self.source_map.span_extend_while(self.position, |c| {
+                if c == '\n' {
+                    let count_v = count.get();
+                    count.set(count_v + 1);
+                    if count_v >= line {
+                        return false;
+                    }
+                }
+                true
+            }) {
+                Ok(sp) => self.source_map.span_extend_to_line(sp.shrink_to_hi()),
+                _ => self.position,
+            }
+        } else {
+            self.position
+        };
         self.tests.push(ScrapedDocTest::new(
             self.get_filename(),
             line,
             self.cur_path.clone(),
             config,
             test,
+            span,
         ));
     }
 

src/librustdoc/doctest/tests.rs

@@ -1,8 +1,6 @@
 use std::path::PathBuf;
 
-use rustc_span::edition::DEFAULT_EDITION;
-
-use super::{DocTestBuilder, GlobalTestOptions};
+use super::{BuildDocTestBuilder, GlobalTestOptions};
 
 fn make_test(
     test_code: &str,
@@ -11,14 +9,14 @@ fn make_test(
     opts: &GlobalTestOptions,
     test_id: Option<&str>,
 ) -> (String, usize) {
-    let doctest = DocTestBuilder::new(
-        test_code,
-        crate_name,
-        DEFAULT_EDITION,
-        false,
-        test_id.map(|s| s.to_string()),
-        None,
-    );
+    let mut builder = BuildDocTestBuilder::new(test_code);
+    if let Some(crate_name) = crate_name {
+        builder = builder.crate_name(crate_name);
+    }
+    if let Some(test_id) = test_id {
+        builder = builder.test_id(test_id.to_string());
+    }
+    let doctest = builder.build(None);
     let (code, line_offset) =
         doctest.generate_unique_doctest(test_code, dont_insert_main, opts, crate_name);
     (code, line_offset)

src/librustdoc/html/markdown.rs

@@ -303,7 +303,11 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
                 attrs: vec![],
                 args_file: PathBuf::new(),
             };
-            let doctest = doctest::DocTestBuilder::new(&test, krate, edition, false, None, None);
+            let mut builder = doctest::BuildDocTestBuilder::new(&test).edition(edition);
+            if let Some(krate) = krate {
+                builder = builder.crate_name(krate);
+            }
+            let doctest = builder.build(None);
             let (test, _) = doctest.generate_unique_doctest(&test, false, &opts, krate);
             let channel = if test.contains("#![feature(") { "&amp;version=nightly" } else { "" };
 

src/librustdoc/html/static/js/main.js

@@ -1179,8 +1179,10 @@ function preLoadCss(cssUrl) {
 
     onEachLazy(document.querySelectorAll(".toggle > summary:not(.hideme)"), el => {
         // @ts-expect-error
+        // Clicking on the summary's contents should not collapse it,
+        // but links within should still fire.
         el.addEventListener("click", e => {
-            if (e.target.tagName !== "SUMMARY" && e.target.tagName !== "A") {
+            if (!e.target.matches("summary, a, a *")) {
                 e.preventDefault();
             }
         });

src/rustdoc-json-types/lib.rs

@@ -180,19 +180,13 @@ pub struct Item {
     ///
     /// Does not include `#[deprecated]` attributes: see the [`Self::deprecation`] field instead.
     ///
-    /// Some attributes appear in pretty-printed Rust form, regardless of their formatting
+    /// Attributes appear in pretty-printed Rust form, regardless of their formatting
     /// in the original source code. For example:
     /// - `#[non_exhaustive]` and `#[must_use]` are represented as themselves.
     /// - `#[no_mangle]` and `#[export_name]` are also represented as themselves.
     /// - `#[repr(C)]` and other reprs also appear as themselves,
     ///   though potentially with a different order: e.g. `repr(i8, C)` may become `repr(C, i8)`.
     ///   Multiple repr attributes on the same item may be combined into an equivalent single attr.
-    ///
-    /// Other attributes may appear debug-printed. For example:
-    /// - `#[inline]` becomes something similar to `#[attr="Inline(Hint)"]`.
-    ///
-    /// As an internal implementation detail subject to change, this debug-printing format
-    /// is currently equivalent to the HIR pretty-printing of parsed attributes.
     pub attrs: Vec<String>,
     /// Information about the item’s deprecation, if present.
     pub deprecation: Option<Deprecation>,

src/tools/clippy/CHANGELOG.md

@@ -6440,6 +6440,7 @@ Released 2018-09-13
 [`used_underscore_items`]: https://rust-lang.github.io/rust-clippy/master/index.html#used_underscore_items
 [`useless_asref`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_asref
 [`useless_attribute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_attribute
+[`useless_concat`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_concat
 [`useless_conversion`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
 [`useless_format`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
 [`useless_let_if_seq`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_let_if_seq

src/tools/clippy/CONTRIBUTING.md

@@ -51,7 +51,7 @@ Clippy team directly by mentioning them in the issue or over on [Zulip]. All
 currently active team members can be found
 [here](https://github.com/rust-lang/rust-clippy/blob/master/triagebot.toml#L18)
 
-Some issues are easier than others. The [`good-first-issue`] label can be used to find the easy
+Some issues are easier than others. The [`good first issue`] label can be used to find the easy
 issues. You can use `@rustbot claim` to assign the issue to yourself.
 
 There are also some abandoned PRs, marked with [`S-inactive-closed`].
@@ -70,7 +70,7 @@ To figure out how this syntax structure is encoded in the AST, it is recommended
 Usually the lint will end up to be a nested series of matches and ifs, [like so][deep-nesting].
 But we can make it nest-less by using [let chains], [like this][nest-less].
 
-[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an [`good-first-issue`]
+[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an [`good first issue`]
 first. Sometimes they are only somewhat involved code wise, but not difficult per-se.
 Note that [`E-medium`] issues may require some knowledge of Clippy internals or some
 debugging to find the actual problem behind the issue.
@@ -79,7 +79,7 @@ debugging to find the actual problem behind the issue.
 lot of methods that are useful, though one of the most useful would be `expr_ty` (gives the type of
 an AST expression).
 
-[`good-first-issue`]: https://github.com/rust-lang/rust-clippy/labels/good-first-issue
+[`good first issue`]: https://github.com/rust-lang/rust-clippy/labels/good%20first%20issue
 [`S-inactive-closed`]: https://github.com/rust-lang/rust-clippy/pulls?q=is%3Aclosed+label%3AS-inactive-closed
 [`T-AST`]: https://github.com/rust-lang/rust-clippy/labels/T-AST
 [`T-middle`]: https://github.com/rust-lang/rust-clippy/labels/T-middle

src/tools/clippy/Cargo.toml

@@ -1,8 +1,6 @@
 [package]
 name = "clippy"
-# begin autogenerated version
 version = "0.1.89"
-# end autogenerated version
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"