Remove in_band_lifetimes from rustc_trait_selection

See #91867 for more information.

Author: LegionMammal978

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(iter_zip)]
 #![feature(let_else)]
 #![feature(never_type)]

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(
-    selcx: &mut SelectionContext<'cx, 'tcx>,
+fn overlap_within_probe<'tcx>(
+    selcx: &mut SelectionContext<'_, '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<'tcx>(
+        selcx: &mut SelectionContext<'_, '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<'tcx>(
+        selcx: &SelectionContext<'_, '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

@@ -1156,10 +1156,10 @@ trait InferCtxtPrivExt<'tcx> {
         &self,
         err: &mut DiagnosticBuilder<'tcx>,
         span: Span,
-        node: Node<'hir>,
+        node: Node<'_>,
     );
 
-    fn maybe_indirection_for_unsized(
+    fn maybe_indirection_for_unsized<'hir>(
         &self,
         err: &mut DiagnosticBuilder<'tcx>,
         item: &'hir Item<'hir>,
@@ -2027,7 +2027,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
         &self,
         err: &mut DiagnosticBuilder<'tcx>,
         span: Span,
-        node: Node<'hir>,
+        node: Node<'_>,
     ) {
         let generics = match node.generics() {
             Some(generics) => generics,
@@ -2090,7 +2090,7 @@ 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>,
@@ -2204,7 +2204,7 @@ 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

@@ -192,7 +192,7 @@ 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>,