Rollup of 8 pull requests

compiler/rustc_ast_lowering/src/expr.rs

@@ -9,7 +9,6 @@ use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::definitions::DefPathData;
-use rustc_session::parse::feature_err;
 use rustc_span::hygiene::ExpnId;
 use rustc_span::source_map::{respan, DesugaringKind, Span, Spanned};
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -930,24 +929,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 self.lower_span(eq_sign_span),
             );
         }
-        if !self.sess.features_untracked().destructuring_assignment {
-            let mut err = feature_err(
-                &self.sess.parse_sess,
-                sym::destructuring_assignment,
-                eq_sign_span,
-                "destructuring assignments are unstable",
-            );
-            err.span_label(lhs.span, "cannot assign to this expression");
-            if self.is_in_loop_condition {
-                err.span_suggestion_verbose(
-                    lhs.span.shrink_to_lo(),
-                    "you might have meant to use pattern destructuring",
-                    "let ".to_string(),
-                    rustc_errors::Applicability::MachineApplicable,
-                );
-            }
-            err.emit();
-        }
 
         let mut assignments = vec![];
 

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -724,11 +724,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
     gate_all!(half_open_range_patterns, "half-open range patterns are unstable");
     gate_all!(inline_const, "inline-const is experimental");
     gate_all!(inline_const_pat, "inline-const in pattern position is experimental");
-    if sess.parse_sess.span_diagnostic.err_count() == 0 {
-        // Errors for `destructuring_assignment` can get quite noisy, especially where `_` is
-        // involved, so we only emit errors where there are no other parsing errors.
-        gate_all!(destructuring_assignment, "destructuring assignments are unstable");
-    }
 
     // All uses of `gate_all!` below this point were added in #65742,
     // and subsequently disabled (with the non-early gating readded).

compiler/rustc_borrowck/src/borrow_set.rs

@@ -84,7 +84,7 @@ pub enum LocalsStateAtExit {
 }
 
 impl LocalsStateAtExit {
-    fn build(
+    fn build<'tcx>(
         locals_are_invalidated_at_exit: bool,
         body: &Body<'tcx>,
         move_data: &MoveData<'tcx>,

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -31,7 +31,7 @@ enum UniverseInfoInner<'tcx> {
     Other,
 }
 
-impl UniverseInfo<'tcx> {
+impl<'tcx> UniverseInfo<'tcx> {
     crate fn other() -> UniverseInfo<'tcx> {
         UniverseInfo(UniverseInfoInner::Other)
     }
@@ -191,7 +191,7 @@ struct PredicateQuery<'tcx> {
     base_universe: ty::UniverseIndex,
 }
 
-impl TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
+impl<'tcx> TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
     fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
         let mut err = tcx.sess.struct_span_err(span, "higher-ranked lifetime error");
         err.note(&format!("could not prove {}", self.canonical_query.value.value.predicate));
@@ -231,7 +231,7 @@ struct NormalizeQuery<'tcx, T> {
     base_universe: ty::UniverseIndex,
 }
 
-impl<T> TypeOpInfo<'tcx> for NormalizeQuery<'tcx, T>
+impl<'tcx, T> TypeOpInfo<'tcx> for NormalizeQuery<'tcx, T>
 where
     T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx,
 {
@@ -291,7 +291,7 @@ struct AscribeUserTypeQuery<'tcx> {
     base_universe: ty::UniverseIndex,
 }
 
-impl TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
+impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
     fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
         // FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
         // and is only the fallback when the nice error fails. Consider improving this some more.

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1598,8 +1598,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         location: Location,
         mpi: MovePathIndex,
     ) -> (Vec<MoveSite>, Vec<Location>) {
-        fn predecessor_locations(
-            body: &'a mir::Body<'tcx>,
+        fn predecessor_locations<'a>(
+            body: &'a mir::Body<'_>,
             location: Location,
         ) -> impl Iterator<Item = Location> + 'a {
             if location.statement_index == 0 {

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -409,7 +409,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     /// Add a note that a type does not implement `Copy`
     pub(super) fn note_type_does_not_implement_copy(
         &self,
-        err: &mut DiagnosticBuilder<'a>,
+        err: &mut DiagnosticBuilder<'_>,
         place_desc: &str,
         ty: Ty<'tcx>,
         span: Option<Span>,
@@ -733,7 +733,7 @@ pub(super) enum BorrowedContentSource<'tcx> {
     OverloadedIndex(Ty<'tcx>),
 }
 
-impl BorrowedContentSource<'tcx> {
+impl<'tcx> BorrowedContentSource<'tcx> {
     pub(super) fn describe_for_unnamed_place(&self, tcx: TyCtxt<'_>) -> String {
         match *self {
             BorrowedContentSource::DerefRawPointer => "a raw pointer".to_string(),

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -747,7 +747,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             HirId, ImplItem, ImplItemKind, Item, ItemKind,
         };
 
-        fn maybe_body_id_of_fn(hir_map: &Map<'tcx>, id: HirId) -> Option<BodyId> {
+        fn maybe_body_id_of_fn(hir_map: &Map<'_>, id: HirId) -> Option<BodyId> {
             match hir_map.find(id) {
                 Some(Node::Item(Item { kind: ItemKind::Fn(_, _, body_id), .. }))
                 | Some(Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(_, body_id), .. })) => {
@@ -1066,7 +1066,7 @@ fn is_closure_or_generator(ty: Ty<'_>) -> bool {
 /// LL |     s: &'a String
 ///    |        ---------- use `&'a mut String` here to make mutable
 /// ```
-fn annotate_struct_field(
+fn annotate_struct_field<'tcx>(
     tcx: TyCtxt<'tcx>,
     ty: Ty<'tcx>,
     field: &mir::Field,

compiler/rustc_borrowck/src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(crate_visibility_modifier)]
-#![feature(in_band_lifetimes)]
 #![feature(iter_zip)]
 #![feature(let_else)]
 #![feature(min_specialization)]

compiler/rustc_borrowck/src/member_constraints.rs

@@ -53,7 +53,7 @@ rustc_index::newtype_index! {
     }
 }
 
-impl Default for MemberConstraintSet<'tcx, ty::RegionVid> {
+impl Default for MemberConstraintSet<'_, ty::RegionVid> {
     fn default() -> Self {
         Self {
             first_constraints: Default::default(),
@@ -97,7 +97,7 @@ impl<'tcx> MemberConstraintSet<'tcx, ty::RegionVid> {
     }
 }
 
-impl<R1> MemberConstraintSet<'tcx, R1>
+impl<'tcx, R1> MemberConstraintSet<'tcx, R1>
 where
     R1: Copy + Hash + Eq,
 {
@@ -140,7 +140,7 @@ where
     }
 }
 
-impl<R> MemberConstraintSet<'tcx, R>
+impl<R> MemberConstraintSet<'_, R>
 where
     R: Copy + Hash + Eq,
 {

compiler/rustc_borrowck/src/path_utils.rs

@@ -141,7 +141,7 @@ pub(super) fn borrow_of_local_data(place: Place<'_>) -> bool {
 /// then returns the index of the field being projected. Note that this closure will always
 /// be `self` in the current MIR, because that is the only time we directly access the fields
 /// of a closure type.
-pub(crate) fn is_upvar_field_projection(
+pub(crate) fn is_upvar_field_projection<'tcx>(
     tcx: TyCtxt<'tcx>,
     upvars: &[Upvar<'tcx>],
     place_ref: PlaceRef<'tcx>,

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -58,7 +58,7 @@ crate struct CreateResult<'tcx> {
     crate normalized_inputs_and_output: NormalizedInputsAndOutput<'tcx>,
 }
 
-crate fn create(
+crate fn create<'tcx>(
     infcx: &InferCtxt<'_, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     implicit_region_bound: Option<ty::Region<'tcx>>,
@@ -81,7 +81,7 @@ crate fn create(
     .create()
 }
 
-impl UniversalRegionRelations<'tcx> {
+impl UniversalRegionRelations<'_> {
     /// Records in the `outlives_relation` (and
     /// `inverse_outlives_relation`) that `fr_a: fr_b`. Invoked by the
     /// builder below.
@@ -110,7 +110,7 @@ impl UniversalRegionRelations<'tcx> {
     /// outlives `fr` and (b) is not local.
     ///
     /// (*) If there are multiple competing choices, we return all of them.
-    crate fn non_local_upper_bounds(&'a self, fr: &'a RegionVid) -> Vec<&'a RegionVid> {
+    crate fn non_local_upper_bounds<'a>(&'a self, fr: &'a RegionVid) -> Vec<&'a RegionVid> {
         debug!("non_local_upper_bound(fr={:?})", fr);
         let res = self.non_local_bounds(&self.inverse_outlives, fr);
         assert!(!res.is_empty(), "can't find an upper bound!?");
@@ -232,7 +232,7 @@ struct UniversalRegionRelationsBuilder<'this, 'tcx> {
     region_bound_pairs: RegionBoundPairs<'tcx>,
 }
 
-impl UniversalRegionRelationsBuilder<'cx, 'tcx> {
+impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
     crate fn create(mut self) -> CreateResult<'tcx> {
         let unnormalized_input_output_tys = self
             .universal_regions

compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs

@@ -152,7 +152,7 @@ impl LocalUseMapBuild<'_> {
     }
 }
 
-impl Visitor<'tcx> for LocalUseMapBuild<'_> {
+impl Visitor<'_> for LocalUseMapBuild<'_> {
     fn visit_local(&mut self, &local: &Local, context: PlaceContext, location: Location) {
         if self.locals_with_use_data[local] {
             match def_use::categorize(context) {

compiler/rustc_borrowck/src/type_check/liveness/mod.rs

@@ -74,7 +74,7 @@ pub(super) fn generate<'mir, 'tcx>(
 // to compute whether a variable `X` is live if that variable contains
 // some region `R` in its type where `R` is not known to outlive a free
 // region (i.e., where `R` may be valid for just a subset of the fn body).
-fn compute_live_locals(
+fn compute_live_locals<'tcx>(
     tcx: TyCtxt<'tcx>,
     free_regions: &FxHashSet<RegionVid>,
     body: &Body<'tcx>,
@@ -104,7 +104,7 @@ fn compute_live_locals(
 /// regions. For these regions, we do not need to compute
 /// liveness, since the outlives constraints will ensure that they
 /// are live over the whole fn body anyhow.
-fn regions_that_outlive_free_regions(
+fn regions_that_outlive_free_regions<'tcx>(
     num_region_vars: usize,
     universal_regions: &UniversalRegions<'tcx>,
     constraint_set: &OutlivesConstraintSet<'tcx>,

compiler/rustc_borrowck/src/type_check/liveness/polonius.rs

@@ -53,7 +53,7 @@ impl UseFactsExtractor<'_> {
     }
 }
 
-impl Visitor<'tcx> for UseFactsExtractor<'_> {
+impl Visitor<'_> for UseFactsExtractor<'_> {
     fn visit_local(&mut self, &local: &Local, context: PlaceContext, location: Location) {
         match def_use::categorize(context) {
             Some(DefUse::Def) => self.insert_def(local, location),
@@ -63,7 +63,7 @@ impl Visitor<'tcx> for UseFactsExtractor<'_> {
         }
     }
 
-    fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, location: Location) {
+    fn visit_place(&mut self, place: &Place<'_>, context: PlaceContext, location: Location) {
         self.super_place(place, context, location);
         match context {
             PlaceContext::NonMutatingUse(_) => {
@@ -82,7 +82,7 @@ impl Visitor<'tcx> for UseFactsExtractor<'_> {
     }
 }
 
-pub(super) fn populate_access_facts(
+pub(super) fn populate_access_facts<'tcx>(
     typeck: &mut TypeChecker<'_, 'tcx>,
     body: &Body<'tcx>,
     location_table: &LocationTable,
@@ -123,7 +123,7 @@ pub(super) fn populate_access_facts(
 
 // For every potentially drop()-touched region `region` in `local`'s type
 // (`kind`), emit a Polonius `use_of_var_derefs_origin(local, origin)` fact.
-pub(super) fn add_drop_of_var_derefs_origin(
+pub(super) fn add_drop_of_var_derefs_origin<'tcx>(
     typeck: &mut TypeChecker<'_, 'tcx>,
     local: Local,
     kind: &GenericArg<'tcx>,

compiler/rustc_borrowck/src/type_check/liveness/trace.rs

@@ -34,7 +34,7 @@ use crate::{
 /// DROP-LIVE set are to the liveness sets for regions found in the
 /// `dropck_outlives` result of the variable's type (in particular,
 /// this respects `#[may_dangle]` annotations).
-pub(super) fn trace(
+pub(super) fn trace<'mir, 'tcx>(
     typeck: &mut TypeChecker<'_, 'tcx>,
     body: &Body<'tcx>,
     elements: &Rc<RegionValueElements>,
@@ -119,7 +119,7 @@ struct LivenessResults<'me, 'typeck, 'flow, 'tcx> {
     stack: Vec<PointIndex>,
 }
 
-impl LivenessResults<'me, 'typeck, 'flow, 'tcx> {
+impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
     fn new(cx: LivenessContext<'me, 'typeck, 'flow, 'tcx>) -> Self {
         let num_points = cx.elements.num_points();
         LivenessResults {
@@ -418,7 +418,7 @@ impl LivenessResults<'me, 'typeck, 'flow, 'tcx> {
     }
 }
 
-impl LivenessContext<'_, '_, '_, 'tcx> {
+impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
     /// Returns `true` if the local variable (or some part of it) is initialized at the current
     /// cursor position. Callers should call one of the `seek` methods immediately before to point
     /// the cursor to the desired location.

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -945,7 +945,7 @@ crate struct MirTypeckRegionConstraints<'tcx> {
     crate type_tests: Vec<TypeTest<'tcx>>,
 }
 
-impl MirTypeckRegionConstraints<'tcx> {
+impl<'tcx> MirTypeckRegionConstraints<'tcx> {
     fn placeholder_region(
         &mut self,
         infcx: &InferCtxt<'_, 'tcx>,

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -51,7 +51,7 @@ struct NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
     universe_info: UniverseInfo<'tcx>,
 }
 
-impl NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
+impl<'me, 'bccx, 'tcx> NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
     fn new(
         type_checker: &'me mut TypeChecker<'bccx, 'tcx>,
         locations: Locations,
@@ -62,7 +62,7 @@ impl NllTypeRelatingDelegate<'me, 'bccx, 'tcx> {
     }
 }
 
-impl TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx> {
+impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx> {
     fn param_env(&self) -> ty::ParamEnv<'tcx> {
         self.type_checker.param_env
     }

compiler/rustc_expand/src/lib.rs

@@ -1,6 +1,6 @@
 #![feature(crate_visibility_modifier)]
 #![feature(decl_macro)]
-#![feature(destructuring_assignment)]
+#![cfg_attr(bootstrap, feature(destructuring_assignment))]
 #![feature(if_let_guard)]
 #![feature(iter_zip)]
 #![feature(let_else)]

compiler/rustc_feature/src/accepted.rs

@@ -114,6 +114,8 @@ declare_features! (
     (accepted, default_type_params, "1.0.0", None, None),
     /// Allows `#[deprecated]` attribute.
     (accepted, deprecated, "1.9.0", Some(29935), None),
+    /// Allows the use of destructuring assignments.
+    (accepted, destructuring_assignment, "1.59.0", Some(71126), None),
     /// Allows `#[doc(alias = "...")]`.
     (accepted, doc_alias, "1.48.0", Some(50146), None),
     /// Allows `..` in tuple (struct) patterns.

compiler/rustc_feature/src/active.rs

@@ -356,8 +356,6 @@ declare_features! (
     (active, default_type_parameter_fallback, "1.3.0", Some(27336), None),
     /// Allows `#[derive(Default)]` and `#[default]` on enums.
     (active, derive_default_enum, "1.56.0", Some(86985), None),
-    /// Allows the use of destructuring assignments.
-    (active, destructuring_assignment, "1.49.0", Some(71126), None),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
     (active, doc_auto_cfg, "1.58.0", Some(43781), None),
     /// Allows `#[doc(cfg(...))]`.

compiler/rustc_mir_transform/src/reveal_all.rs

@@ -36,6 +36,9 @@ impl<'tcx> MutVisitor<'tcx> for RevealAllVisitor<'tcx> {
 
     #[inline]
     fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: TyContext) {
-        *ty = self.tcx.normalize_erasing_regions(self.param_env, ty);
+        // We have to use `try_normalize_erasing_regions` here, since it's
+        // possible that we visit impossible-to-satisfy where clauses here,
+        // see #91745
+        *ty = self.tcx.try_normalize_erasing_regions(self.param_env, *ty).unwrap_or(ty);
     }
 }

compiler/rustc_parse/src/parser/expr.rs

@@ -1265,7 +1265,6 @@ impl<'a> Parser<'a> {
         } else if self.eat_keyword(kw::Let) {
             self.parse_let_expr(attrs)
         } else if self.eat_keyword(kw::Underscore) {
-            self.sess.gated_spans.gate(sym::destructuring_assignment, self.prev_token.span);
             Ok(self.mk_expr(self.prev_token.span, ExprKind::Underscore, attrs))
         } else if !self.unclosed_delims.is_empty() && self.check(&token::Semi) {
             // Don't complain about bare semicolons after unclosed braces
@@ -2588,7 +2587,6 @@ impl<'a> Parser<'a> {
                 let exp_span = self.prev_token.span;
                 // We permit `.. }` on the left-hand side of a destructuring assignment.
                 if self.check(&token::CloseDelim(close_delim)) {
-                    self.sess.gated_spans.gate(sym::destructuring_assignment, self.prev_token.span);
                     base = ast::StructRest::Rest(self.prev_token.span.shrink_to_hi());
                     break;
                 }