Rollup merge of #91904 - SylvanB:remove_in_band_lifetimes_rustc_trait_selection, r=petrochenkov

Remove `in_band_lifetimes` from `rustc_trait_selection`

Another one for #91867

compiler/rustc_trait_selection/src/lib.rs

@@ -16,7 +16,6 @@
 #![feature(drain_filter)]
 #![feature(derive_default_enum)]
 #![feature(hash_drain_filter)]
-#![feature(in_band_lifetimes)]
 #![feature(let_else)]
 #![feature(never_type)]
 #![feature(crate_visibility_modifier)]

compiler/rustc_trait_selection/src/opaque_types.rs

@@ -97,7 +97,7 @@ struct ReverseMapper<'tcx> {
     span: Span,
 }
 
-impl ReverseMapper<'tcx> {
+impl<'tcx> ReverseMapper<'tcx> {
     fn new(
         tcx: TyCtxt<'tcx>,
         tainted_by_errors: bool,
@@ -134,7 +134,7 @@ impl ReverseMapper<'tcx> {
     }
 }
 
-impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
+impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
@@ -338,7 +338,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
 /// Requires that trait definitions have been processed so that we can
 /// elaborate predicates and walk supertraits.
 #[instrument(skip(tcx, predicates), level = "debug")]
-crate fn required_region_bounds(
+crate fn required_region_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
     erased_self_ty: Ty<'tcx>,
     predicates: impl Iterator<Item = ty::Predicate<'tcx>>,

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -219,7 +219,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
     }
 }
 
-impl AutoTraitFinder<'tcx> {
+impl<'tcx> AutoTraitFinder<'tcx> {
     /// The core logic responsible for computing the bounds for our synthesized impl.
     ///
     /// To calculate the bounds, we call `SelectionContext.select` in a loop. Like

compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs

@@ -16,7 +16,7 @@ pub struct FulfillmentContext<'tcx> {
     relationships: FxHashMap<ty::TyVid, ty::FoundRelationships>,
 }
 
-impl FulfillmentContext<'tcx> {
+impl FulfillmentContext<'_> {
     crate fn new() -> Self {
         FulfillmentContext {
             obligations: FxIndexSet::default(),
@@ -25,7 +25,7 @@ impl FulfillmentContext<'tcx> {
     }
 }
 
-impl TraitEngine<'tcx> for FulfillmentContext<'tcx> {
+impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
     fn normalize_projection_type(
         &mut self,
         infcx: &InferCtxt<'_, 'tcx>,

compiler/rustc_trait_selection/src/traits/codegen.rs

@@ -107,7 +107,7 @@ pub fn codegen_fulfill_obligation<'tcx>(
 /// type inference variables that appear in `result` to be
 /// unified, and hence we need to process those obligations to get
 /// the complete picture of the type.
-fn drain_fulfillment_cx_or_panic<T>(
+fn drain_fulfillment_cx_or_panic<'tcx, T>(
     infcx: &InferCtxt<'_, 'tcx>,
     fulfill_cx: &mut FulfillmentContext<'tcx>,
     result: T,

compiler/rustc_trait_selection/src/traits/coherence.rs

@@ -154,18 +154,24 @@ fn overlap<'cx, 'tcx>(
     })
 }
 
-fn overlap_within_probe(
+fn overlap_within_probe<'cx, 'tcx>(
     selcx: &mut SelectionContext<'cx, 'tcx>,
     skip_leak_check: SkipLeakCheck,
     a_def_id: DefId,
     b_def_id: DefId,
     snapshot: &CombinedSnapshot<'_, 'tcx>,
 ) -> Option<OverlapResult<'tcx>> {
-    fn loose_check(selcx: &mut SelectionContext<'cx, 'tcx>, o: &PredicateObligation<'tcx>) -> bool {
+    fn loose_check<'cx, 'tcx>(
+        selcx: &mut SelectionContext<'cx, 'tcx>,
+        o: &PredicateObligation<'tcx>,
+    ) -> bool {
         !selcx.predicate_may_hold_fatal(o)
     }
 
-    fn strict_check(selcx: &SelectionContext<'cx, 'tcx>, o: &PredicateObligation<'tcx>) -> bool {
+    fn strict_check<'cx, 'tcx>(
+        selcx: &SelectionContext<'cx, 'tcx>,
+        o: &PredicateObligation<'tcx>,
+    ) -> bool {
         let infcx = selcx.infcx();
         let tcx = infcx.tcx;
         o.flip_polarity(tcx)
@@ -518,7 +524,11 @@ fn orphan_check_trait_ref<'tcx>(
 /// - for `Foo<u32>`, where `Foo` is a local type, this returns `[]`.
 /// - `&mut u32` returns `[u32]`, as `&mut` is a fundamental type, similar to `Box`.
 /// - `Box<Foo<u32>>` returns `[]`, as `Box` is a fundamental type and `Foo` is local.
-fn contained_non_local_types(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, in_crate: InCrate) -> Vec<Ty<'tcx>> {
+fn contained_non_local_types<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ty: Ty<'tcx>,
+    in_crate: InCrate,
+) -> Vec<Ty<'tcx>> {
     if ty_is_local_constructor(ty, in_crate) {
         Vec::new()
     } else {
@@ -534,7 +544,7 @@ fn contained_non_local_types(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, in_crate: InCrate)
 /// For `#[fundamental]` ADTs and `&T` / `&mut T`, returns `Some` with the
 /// type parameters of the ADT, or `T`, respectively. For non-fundamental
 /// types, returns `None`.
-fn fundamental_ty_inner_tys(
+fn fundamental_ty_inner_tys<'tcx>(
     tcx: TyCtxt<'tcx>,
     ty: Ty<'tcx>,
 ) -> Option<impl Iterator<Item = Ty<'tcx>>> {

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

@@ -1063,7 +1063,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
     }
 }
 
-trait InferCtxtPrivExt<'tcx> {
+trait InferCtxtPrivExt<'hir, 'tcx> {
     // returns if `cond` not occurring implies that `error` does not occur - i.e., that
     // `error` occurring implies that `cond` occurs.
     fn error_implies(&self, cond: ty::Predicate<'tcx>, error: ty::Predicate<'tcx>) -> bool;
@@ -1174,7 +1174,7 @@ trait InferCtxtPrivExt<'tcx> {
     ) -> bool;
 }
 
-impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
+impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
     // returns if `cond` not occurring implies that `error` does not occur - i.e., that
     // `error` occurring implies that `cond` occurs.
     fn error_implies(&self, cond: ty::Predicate<'tcx>, error: ty::Predicate<'tcx>) -> bool {
@@ -2042,7 +2042,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
         self.maybe_suggest_unsized_generics(err, span, node);
     }
 
-    fn maybe_suggest_unsized_generics(
+    fn maybe_suggest_unsized_generics<'hir>(
         &self,
         err: &mut DiagnosticBuilder<'tcx>,
         span: Span,
@@ -2109,7 +2109,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
         );
     }
 
-    fn maybe_indirection_for_unsized(
+    fn maybe_indirection_for_unsized<'hir>(
         &self,
         err: &mut DiagnosticBuilder<'tcx>,
         item: &'hir Item<'hir>,
@@ -2223,7 +2223,7 @@ impl<'v> Visitor<'v> for FindTypeParam {
 }
 
 pub fn recursive_type_with_infinite_size_error(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     type_def_id: DefId,
     spans: Vec<Span>,
 ) {

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

@@ -198,7 +198,7 @@ fn predicate_constraint(generics: &hir::Generics<'_>, pred: String) -> (Span, St
 /// Type parameter needs more bounds. The trivial case is `T` `where T: Bound`, but
 /// it can also be an `impl Trait` param that needs to be decomposed to a type
 /// param for cleaner code.
-fn suggest_restriction(
+fn suggest_restriction<'tcx>(
     tcx: TyCtxt<'tcx>,
     generics: &hir::Generics<'tcx>,
     msg: &str,

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -252,7 +252,7 @@ struct FulfillProcessor<'a, 'b, 'tcx> {
     register_region_obligations: bool,
 }
 
-fn mk_pending(os: Vec<PredicateObligation<'tcx>>) -> Vec<PendingPredicateObligation<'tcx>> {
+fn mk_pending(os: Vec<PredicateObligation<'_>>) -> Vec<PendingPredicateObligation<'_>> {
     os.into_iter()
         .map(|o| PendingPredicateObligation { obligation: o, stalled_on: vec![] })
         .collect()

compiler/rustc_trait_selection/src/traits/misc.rs

@@ -16,7 +16,7 @@ pub enum CopyImplementationError<'tcx> {
     HasDestructor,
 }
 
-pub fn can_type_implement_copy(
+pub fn can_type_implement_copy<'tcx>(
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     self_type: Ty<'tcx>,

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -801,7 +801,7 @@ fn vtable_trait_first_method_offset<'tcx>(
 }
 
 /// Find slot offset for trait vptr within vtable entries of another trait
-pub fn vtable_trait_upcasting_coercion_new_vptr_slot(
+pub fn vtable_trait_upcasting_coercion_new_vptr_slot<'tcx>(
     tcx: TyCtxt<'tcx>,
     key: (
         Ty<'tcx>, // trait object type whose trait owning vtable

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -50,10 +50,7 @@ pub fn astconv_object_safety_violations(
     violations
 }
 
-fn object_safety_violations(
+fn object_safety_violations(tcx: TyCtxt<'_>, trait_def_id: DefId) -> &'_ [ObjectSafetyViolation] {
-    tcx: TyCtxt<'tcx>,
-    trait_def_id: DefId,
-) -> &'tcx [ObjectSafetyViolation] {
     debug_assert!(tcx.generics_of(trait_def_id).has_self);
     debug!("object_safety_violations: {:?}", trait_def_id);
 
@@ -272,7 +269,7 @@ fn bounds_reference_self(tcx: TyCtxt<'_>, trait_def_id: DefId) -> SmallVec<[Span
         .collect()
 }
 
-fn predicate_references_self(
+fn predicate_references_self<'tcx>(
     tcx: TyCtxt<'tcx>,
     (predicate, sp): (ty::Predicate<'tcx>, Span),
 ) -> Option<Span> {

compiler/rustc_trait_selection/src/traits/project.rs

@@ -570,7 +570,7 @@ impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> {
     }
 }
 
-impl TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> {
+impl<'tcx> TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
@@ -678,7 +678,7 @@ impl<'me, 'tcx> PlaceholderReplacer<'me, 'tcx> {
     }
 }
 
-impl TypeFolder<'tcx> for PlaceholderReplacer<'_, 'tcx> {
+impl<'tcx> TypeFolder<'tcx> for PlaceholderReplacer<'_, 'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
@@ -1937,14 +1937,14 @@ fn assoc_ty_def(
     }
 }
 
-crate trait ProjectionCacheKeyExt<'tcx>: Sized {
+crate trait ProjectionCacheKeyExt<'cx, 'tcx>: Sized {
     fn from_poly_projection_predicate(
         selcx: &mut SelectionContext<'cx, 'tcx>,
         predicate: ty::PolyProjectionPredicate<'tcx>,
     ) -> Option<Self>;
 }
 
-impl<'tcx> ProjectionCacheKeyExt<'tcx> for ProjectionCacheKey<'tcx> {
+impl<'cx, 'tcx> ProjectionCacheKeyExt<'cx, 'tcx> for ProjectionCacheKey<'tcx> {
     fn from_poly_projection_predicate(
         selcx: &mut SelectionContext<'cx, 'tcx>,
         predicate: ty::PolyProjectionPredicate<'tcx>,

compiler/rustc_trait_selection/src/traits/query/type_op/normalize.rs

@@ -31,7 +31,7 @@ pub trait Normalizable<'tcx>: fmt::Debug + TypeFoldable<'tcx> + Lift<'tcx> + Cop
     ) -> Fallible<CanonicalizedQueryResponse<'tcx, Self>>;
 }
 
-impl Normalizable<'tcx> for Ty<'tcx> {
+impl<'tcx> Normalizable<'tcx> for Ty<'tcx> {
     fn type_op_method(
         tcx: TyCtxt<'tcx>,
         canonicalized: Canonicalized<'tcx, ParamEnvAnd<'tcx, Normalize<Self>>>,
@@ -40,7 +40,7 @@ impl Normalizable<'tcx> for Ty<'tcx> {
     }
 }
 
-impl Normalizable<'tcx> for ty::Predicate<'tcx> {
+impl<'tcx> Normalizable<'tcx> for ty::Predicate<'tcx> {
     fn type_op_method(
         tcx: TyCtxt<'tcx>,
         canonicalized: Canonicalized<'tcx, ParamEnvAnd<'tcx, Normalize<Self>>>,
@@ -49,7 +49,7 @@ impl Normalizable<'tcx> for ty::Predicate<'tcx> {
     }
 }
 
-impl Normalizable<'tcx> for ty::PolyFnSig<'tcx> {
+impl<'tcx> Normalizable<'tcx> for ty::PolyFnSig<'tcx> {
     fn type_op_method(
         tcx: TyCtxt<'tcx>,
         canonicalized: Canonicalized<'tcx, ParamEnvAnd<'tcx, Normalize<Self>>>,
@@ -58,7 +58,7 @@ impl Normalizable<'tcx> for ty::PolyFnSig<'tcx> {
     }
 }
 
-impl Normalizable<'tcx> for ty::FnSig<'tcx> {
+impl<'tcx> Normalizable<'tcx> for ty::FnSig<'tcx> {
     fn type_op_method(
         tcx: TyCtxt<'tcx>,
         canonicalized: Canonicalized<'tcx, ParamEnvAnd<'tcx, Normalize<Self>>>,

compiler/rustc_trait_selection/src/traits/query/type_op/outlives.rs

@@ -14,7 +14,7 @@ impl<'tcx> DropckOutlives<'tcx> {
     }
 }
 
-impl super::QueryTypeOp<'tcx> for DropckOutlives<'tcx> {
+impl<'tcx> super::QueryTypeOp<'tcx> for DropckOutlives<'tcx> {
     type QueryResponse = DropckOutlivesResult<'tcx>;
 
     fn try_fast_path(

compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs

@@ -32,7 +32,7 @@ enum Inserted {
     ShouldRecurseOn(DefId),
 }
 
-trait ChildrenExt {
+trait ChildrenExt<'tcx> {
     fn insert_blindly(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId);
     fn remove_existing(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId);
 
@@ -44,9 +44,9 @@ trait ChildrenExt {
     ) -> Result<Inserted, OverlapError>;
 }
 
-impl ChildrenExt for Children {
+impl ChildrenExt<'_> for Children {
     /// Insert an impl into this set of children without comparing to any existing impls.
-    fn insert_blindly(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId) {
+    fn insert_blindly(&mut self, tcx: TyCtxt<'_>, impl_def_id: DefId) {
         let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
         if let Some(st) = fast_reject::simplify_type(
             tcx,
@@ -65,7 +65,7 @@ impl ChildrenExt for Children {
     /// Removes an impl from this set of children. Used when replacing
     /// an impl with a parent. The impl must be present in the list of
     /// children already.
-    fn remove_existing(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId) {
+    fn remove_existing(&mut self, tcx: TyCtxt<'_>, impl_def_id: DefId) {
         let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
         let vec: &mut Vec<DefId>;
         if let Some(st) = fast_reject::simplify_type(
@@ -89,7 +89,7 @@ impl ChildrenExt for Children {
     /// specialization relationships.
     fn insert(
         &mut self,
-        tcx: TyCtxt<'tcx>,
+        tcx: TyCtxt<'_>,
         impl_def_id: DefId,
         simplified_self: Option<SimplifiedType>,
     ) -> Result<Inserted, OverlapError> {
@@ -271,12 +271,12 @@ pub trait GraphExt {
     /// information about the area of overlap is returned in the `Err`.
     fn insert(
         &mut self,
-        tcx: TyCtxt<'tcx>,
+        tcx: TyCtxt<'_>,
         impl_def_id: DefId,
     ) -> Result<Option<FutureCompatOverlapError>, OverlapError>;
 
     /// Insert cached metadata mapping from a child impl back to its parent.
-    fn record_impl_from_cstore(&mut self, tcx: TyCtxt<'tcx>, parent: DefId, child: DefId);
+    fn record_impl_from_cstore(&mut self, tcx: TyCtxt<'_>, parent: DefId, child: DefId);
 }
 
 impl GraphExt for Graph {
@@ -285,7 +285,7 @@ impl GraphExt for Graph {
     /// information about the area of overlap is returned in the `Err`.
     fn insert(
         &mut self,
-        tcx: TyCtxt<'tcx>,
+        tcx: TyCtxt<'_>,
         impl_def_id: DefId,
     ) -> Result<Option<FutureCompatOverlapError>, OverlapError> {
         assert!(impl_def_id.is_local());
@@ -385,7 +385,7 @@ impl GraphExt for Graph {
     }
 
     /// Insert cached metadata mapping from a child impl back to its parent.
-    fn record_impl_from_cstore(&mut self, tcx: TyCtxt<'tcx>, parent: DefId, child: DefId) {
+    fn record_impl_from_cstore(&mut self, tcx: TyCtxt<'_>, parent: DefId, child: DefId) {
         if self.parent.insert(child, parent).is_some() {
             bug!(
                 "When recording an impl from the crate store, information about its parent \

compiler/rustc_trait_selection/src/traits/structural_match.rs

@@ -66,7 +66,7 @@ pub fn search_for_structural_match_violation<'tcx>(
 ///
 /// Note that this does *not* recursively check if the substructure of `adt_ty`
 /// implements the traits.
-fn type_marked_structural(
+fn type_marked_structural<'tcx>(
     infcx: &InferCtxt<'_, 'tcx>,
     adt_ty: Ty<'tcx>,
     cause: ObligationCause<'tcx>,
@@ -119,7 +119,7 @@ struct Search<'a, 'tcx> {
     seen: FxHashSet<hir::def_id::DefId>,
 }
 
-impl Search<'a, 'tcx> {
+impl<'a, 'tcx> Search<'a, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }

compiler/rustc_trait_selection/src/traits/util.rs

@@ -172,7 +172,7 @@ pub fn supertrait_def_ids(tcx: TyCtxt<'_>, trait_def_id: DefId) -> SupertraitDef
     }
 }
 
-impl Iterator for SupertraitDefIds<'tcx> {
+impl Iterator for SupertraitDefIds<'_> {
     type Item = DefId;
 
     fn next(&mut self) -> Option<DefId> {
@@ -259,7 +259,7 @@ pub fn predicate_for_trait_ref<'tcx>(
     }
 }
 
-pub fn predicate_for_trait_def(
+pub fn predicate_for_trait_def<'tcx>(
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     cause: ObligationCause<'tcx>,
@@ -276,7 +276,7 @@ pub fn predicate_for_trait_def(
 /// Casts a trait reference into a reference to one of its super
 /// traits; returns `None` if `target_trait_def_id` is not a
 /// supertrait.
-pub fn upcast_choices(
+pub fn upcast_choices<'tcx>(
     tcx: TyCtxt<'tcx>,
     source_trait_ref: ty::PolyTraitRef<'tcx>,
     target_trait_def_id: DefId,
@@ -291,7 +291,10 @@ pub fn upcast_choices(
 /// Given a trait `trait_ref`, returns the number of vtable entries
 /// that come from `trait_ref`, excluding its supertraits. Used in
 /// computing the vtable base for an upcast trait of a trait object.
-pub fn count_own_vtable_entries(tcx: TyCtxt<'tcx>, trait_ref: ty::PolyTraitRef<'tcx>) -> usize {
+pub fn count_own_vtable_entries<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    trait_ref: ty::PolyTraitRef<'tcx>,
+) -> usize {
     let existential_trait_ref =
         trait_ref.map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref));
     let existential_trait_ref = tcx.erase_regions(existential_trait_ref);
@@ -301,7 +304,7 @@ pub fn count_own_vtable_entries(tcx: TyCtxt<'tcx>, trait_ref: ty::PolyTraitRef<'
 /// Given an upcast trait object described by `object`, returns the
 /// index of the method `method_def_id` (which should be part of
 /// `object.upcast_trait_ref`) within the vtable for `object`.
-pub fn get_vtable_index_of_object_method<N>(
+pub fn get_vtable_index_of_object_method<'tcx, N>(
     tcx: TyCtxt<'tcx>,
     object: &super::ImplSourceObjectData<'tcx, N>,
     method_def_id: DefId,
@@ -323,7 +326,7 @@ pub fn get_vtable_index_of_object_method<N>(
     object.vtable_base + index
 }
 
-pub fn closure_trait_ref_and_return_type(
+pub fn closure_trait_ref_and_return_type<'tcx>(
     tcx: TyCtxt<'tcx>,
     fn_trait_def_id: DefId,
     self_ty: Ty<'tcx>,
@@ -342,7 +345,7 @@ pub fn closure_trait_ref_and_return_type(
     sig.map_bound(|sig| (trait_ref, sig.output()))
 }
 
-pub fn generator_trait_ref_and_outputs(
+pub fn generator_trait_ref_and_outputs<'tcx>(
     tcx: TyCtxt<'tcx>,
     fn_trait_def_id: DefId,
     self_ty: Ty<'tcx>,