Alias folding/visiting traits instead of re-export

Jarcho · Feb 13, 2023 · ba55a45 · ba55a45
1 parent 62846d7
commit ba55a45
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Showing 77 changed files with 201 additions and 185 deletions.
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -17,7 +17,7 @@ use rustc_middle::mir::{
 };
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::traits::ObligationCauseCode;
-use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable};
 use rustc_span::Span;
 
 use crate::{

diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -86,7 +86,7 @@ mod prelude {
  pub(crate) use rustc_middle::ty::layout::{self, LayoutOf, TyAndLayout};
  pub(crate) use rustc_middle::ty::{
  self, FloatTy, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut,
- TypeFoldable, TypeVisitable, UintTy,
+ TypeFoldable, UintTy,
  };
  pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx};
 

diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -3,7 +3,7 @@ use crate::traits::*;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, TyAndLayout};
-use rustc_middle::ty::{self, Instance, Ty, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{self, Instance, Ty, TypeFoldable};
 use rustc_target::abi::call::{FnAbi, PassMode};
 
 use std::iter;

diff --git a/compiler/rustc_const_eval/src/interpret/util.rs b/compiler/rustc_const_eval/src/interpret/util.rs
@@ -1,5 +1,5 @@
 use rustc_middle::mir::interpret::InterpResult;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
 use std::ops::ControlFlow;
 
 /// Checks whether a type contains generic parameters which require substitution.

diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -261,7 +261,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
  selftys: Vec<(Span, Option<String>)>,
  }
 
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for ProhibitOpaqueVisitor<'tcx> {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for ProhibitOpaqueVisitor<'tcx> {
  type BreakTy = Ty<'tcx>;
 
  fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
@@ -1447,7 +1447,7 @@ fn opaque_type_cycle_error(
  opaques: Vec<DefId>,
  closures: Vec<DefId>,
  }
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for OpaqueTypeCollector {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for OpaqueTypeCollector {
  fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
  match *t.kind() {
  ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {

diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -16,7 +16,7 @@ use rustc_infer::traits::util;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::util::ExplicitSelf;
 use rustc_middle::ty::{
- self, DefIdTree, InternalSubsts, Ty, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitable,
+ self, ir::TypeFolder, DefIdTree, InternalSubsts, Ty, TypeFoldable, TypeSuperFoldable,
 };
 use rustc_middle::ty::{GenericParamDefKind, ToPredicate, TyCtxt};
 use rustc_span::Span;

diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -16,8 +16,8 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
- self, AdtKind, DefIdTree, GenericParamDefKind, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable,
- TypeVisitable, TypeVisitor,
+ self, ir::TypeVisitor, AdtKind, DefIdTree, GenericParamDefKind, Ty, TyCtxt, TypeFoldable,
+ TypeSuperVisitable,
 };
 use rustc_middle::ty::{GenericArgKind, InternalSubsts};
 use rustc_session::parse::feature_err;
@@ -1435,7 +1435,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
  struct CountParams {
  params: FxHashSet<u32>,
  }
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for CountParams {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for CountParams {
  type BreakTy = ();
 
  fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {

diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -8,7 +8,7 @@ use rustc_hir as hir;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::util::IgnoreRegions;
 use rustc_middle::ty::{
- self, AliasKind, ImplPolarity, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor,
+ self, ir::TypeVisitor, AliasKind, ImplPolarity, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
 };
 use rustc_session::lint;
 use rustc_span::def_id::{DefId, LocalDefId};

diff --git a/compiler/rustc_hir_analysis/src/collect/lifetimes.rs b/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
@@ -17,7 +17,7 @@ use rustc_hir::{GenericArg, GenericParam, GenericParamKind, HirIdMap, LifetimeNa
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime::*;
-use rustc_middle::ty::{self, DefIdTree, TyCtxt, TypeSuperVisitable, TypeVisitor};
+use rustc_middle::ty::{self, ir::TypeVisitor, DefIdTree, TyCtxt, TypeSuperVisitable};
 use rustc_span::def_id::DefId;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;

diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs
@@ -9,7 +9,7 @@ use rustc_middle::ty::print::with_forced_trimmed_paths;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::util::IntTypeExt;
 use rustc_middle::ty::{
- self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable,
+ self, ir::TypeFolder, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeSuperFoldable, TypeVisitable,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{Span, DUMMY_SP};

diff --git a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
@@ -1,5 +1,5 @@
 use rustc_data_structures::fx::FxHashSet;
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable, TypeVisitable};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::source_map::Span;
 use std::ops::ControlFlow;

diff --git a/compiler/rustc_hir_analysis/src/hir_wf_check.rs b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
@@ -5,7 +5,7 @@ use rustc_hir::{ForeignItem, ForeignItemKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{ObligationCause, WellFormedLoc};
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, Region, TyCtxt, TypeFoldable, TypeFolder};
+use rustc_middle::ty::{self, ir::TypeFolder, Region, TyCtxt, TypeFoldable};
 use rustc_span::def_id::LocalDefId;
 use rustc_trait_selection::traits;
 

diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -99,7 +99,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
  }
  }
 
- impl<'tcx> ty::TypeVisitor<'tcx> for OpaqueTypeLifetimeCollector<'tcx> {
+ impl<'tcx> ty::ir::TypeVisitor<'tcx> for OpaqueTypeLifetimeCollector<'tcx> {
  #[instrument(level = "trace", skip(self), ret)]
  fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
  if let ty::RegionKind::ReEarlyBound(ebr) = r.kind() {

diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
@@ -12,7 +12,7 @@ use rustc_infer::infer::{InferOk, InferResult};
 use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, Ty, TypeSuperVisitable, TypeVisitor};
+use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TypeSuperVisitable};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::sym;

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
@@ -3,7 +3,7 @@ use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::ObligationCauseCode;
-use rustc_middle::ty::{self, DefIdTree, Ty, TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::ty::{self, ir::TypeVisitor, DefIdTree, Ty, TypeSuperVisitable, TypeVisitable};
 use rustc_span::{self, Span};
 use rustc_trait_selection::traits;
 

diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs
@@ -51,7 +51,6 @@
 use rustc_middle::hir::place::*;
 use rustc_middle::ty::adjustment;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 
 use rustc_data_structures::fx::FxIndexMap;

diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -20,7 +20,7 @@ use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
 use rustc_middle::ty::AssocItem;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::ToPredicate;
-use rustc_middle::ty::{self, ParamEnvAnd, Ty, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{self, ParamEnvAnd, Ty, TyCtxt, TypeFoldable};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_session::lint;
 use rustc_span::def_id::DefId;

diff --git a/compiler/rustc_hir_typeck/src/op.rs b/compiler/rustc_hir_typeck/src/op.rs
@@ -13,7 +13,7 @@ use rustc_middle::ty::adjustment::{
 };
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{
- self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable,
+ self, ir::TypeFolder, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeSuperFoldable, TypeVisitable,
 };
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;

diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -13,8 +13,8 @@ use rustc_infer::infer::InferCtxt;
 use rustc_middle::hir::place::Place as HirPlace;
 use rustc_middle::mir::FakeReadCause;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast};
-use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::visit::TypeSuperVisitable;
 use rustc_middle::ty::TypeckResults;
 use rustc_middle::ty::{self, ClosureSizeProfileData, Ty, TyCtxt};
 use rustc_span::symbol::sym;
@@ -561,7 +561,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
  struct RecursionChecker {
  def_id: LocalDefId,
  }
- impl<'tcx> ty::TypeVisitor<'tcx> for RecursionChecker {
+ impl<'tcx> ty::ir::TypeVisitor<'tcx> for RecursionChecker {
  type BreakTy = ();
  fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
  if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *t.kind() {

diff --git a/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs b/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
@@ -10,7 +10,7 @@ use crate::infer::canonical::{
 };
 use crate::infer::InferCtxt;
 use rustc_middle::ty::flags::FlagComputation;
-use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
 use rustc_middle::ty::subst::GenericArg;
 use rustc_middle::ty::{self, BoundVar, InferConst, List, Ty, TyCtxt, TypeFlags};
 use std::sync::atomic::Ordering;

diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
@@ -38,8 +38,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{
- self, AliasKind, FallibleTypeFolder, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable,
- TypeSuperFoldable, TypeVisitable,
+ self, ir::FallibleTypeFolder, AliasKind, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable,
+ TypeSuperFoldable,
 };
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::{Span, DUMMY_SP};

diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1491,7 +1491,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
  }
  }
 
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for OpaqueTypesVisitor<'tcx> {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for OpaqueTypesVisitor<'tcx> {
  fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
  if let Some((kind, def_id)) = TyCategory::from_ty(self.tcx, t) {
  let span = self.tcx.def_span(def_id);

diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -17,7 +17,8 @@ use rustc_hir::{
  TyKind,
 };
 use rustc_middle::ty::{
- self, AssocItemContainer, StaticLifetimeVisitor, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor,
+ self, ir::TypeVisitor, AssocItemContainer, StaticLifetimeVisitor, Ty, TyCtxt,
+ TypeSuperVisitable,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::Span;

diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
@@ -75,7 +75,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
  }
  }
 
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for HighlightBuilder<'tcx> {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for HighlightBuilder<'tcx> {
  fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
  if !r.has_name() && self.counter <= 3 {
  self.highlight.highlighting_region(r, self.counter);

diff --git a/compiler/rustc_infer/src/infer/freshen.rs b/compiler/rustc_infer/src/infer/freshen.rs
@@ -33,8 +33,8 @@
 use super::InferCtxt;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::infer::unify_key::ToType;
-use rustc_middle::ty::fold::TypeFolder;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeVisitable};
+use rustc_middle::ty::fold::ir::TypeFolder;
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
 use std::collections::hash_map::Entry;
 
 pub struct TypeFreshener<'a, 'tcx> {

diff --git a/compiler/rustc_infer/src/infer/fudge.rs b/compiler/rustc_infer/src/infer/fudge.rs
@@ -1,4 +1,4 @@
-use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
 use rustc_middle::ty::{self, ConstVid, FloatVid, IntVid, RegionVid, Ty, TyCtxt, TyVid};
 
 use super::type_variable::TypeVariableOrigin;

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
@@ -26,7 +26,7 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::select;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::BoundVarReplacerDelegate;
-use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
 use rustc_middle::ty::relate::RelateResult;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef};
 use rustc_middle::ty::visit::TypeVisitable;

diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
@@ -29,7 +29,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable, TypeVisitable};
 use rustc_middle::ty::{self, InferConst, Ty, TyCtxt};
 use rustc_span::Span;
 use std::fmt::Debug;

diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -12,8 +12,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::GenericArgKind;
 use rustc_middle::ty::{
- self, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable,
- TypeVisitable, TypeVisitor,
+ self, ir::TypeVisitor, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable,
+ TypeSuperVisitable, TypeVisitable,
 };
 use rustc_span::Span;
 

diff --git a/compiler/rustc_infer/src/infer/resolve.rs b/compiler/rustc_infer/src/infer/resolve.rs
@@ -1,9 +1,12 @@
 use super::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use super::{FixupError, FixupResult, InferCtxt, Span};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
-use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFolder, TypeSuperFoldable};
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitor};
-use rustc_middle::ty::{self, Const, InferConst, Ty, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::fold::{
+ ir::{FallibleTypeFolder, TypeFolder},
+ TypeSuperFoldable,
+};
+use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable};
+use rustc_middle::ty::{self, Const, InferConst, Ty, TyCtxt, TypeFoldable};
 
 use std::ops::ControlFlow;
 

diff --git a/compiler/rustc_infer/src/traits/structural_impls.rs b/compiler/rustc_infer/src/traits/structural_impls.rs
@@ -1,8 +1,8 @@
 use crate::traits;
 use crate::traits::project::Normalized;
-use rustc_middle::ty;
 use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable};
 use rustc_middle::ty::visit::{TypeVisitable, TypeVisitor};
+use rustc_middle::ty::{self, ir};
 
 use std::fmt;
 use std::ops::ControlFlow;
@@ -61,7 +61,7 @@ impl<'tcx> fmt::Debug for traits::MismatchedProjectionTypes<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 // TypeFoldable implementations.
 
-impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Obligation<'tcx, O> {
+impl<'tcx, O: TypeFoldable<'tcx>> ir::TypeFoldable<'tcx> for traits::Obligation<'tcx, O> {
  fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
  Ok(traits::Obligation {
  cause: self.cause,
@@ -72,7 +72,7 @@ impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Obligation<'tcx
  }
 }
 
-impl<'tcx, O: TypeVisitable<'tcx>> TypeVisitable<'tcx> for traits::Obligation<'tcx, O> {
+impl<'tcx, O: TypeVisitable<'tcx>> ir::TypeVisitable<'tcx> for traits::Obligation<'tcx, O> {
  fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
  self.predicate.visit_with(visitor)?;
  self.param_env.visit_with(visitor)

diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
@@ -1144,7 +1144,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
 
  fn check_for_opaque_ty(&mut self, sp: Span, ty: Ty<'tcx>) -> bool {
  struct ProhibitOpaqueTypes;
- impl<'tcx> ty::visit::TypeVisitor<'tcx> for ProhibitOpaqueTypes {
+ impl<'tcx> ty::visit::ir::TypeVisitor<'tcx> for ProhibitOpaqueTypes {
  type BreakTy = Ty<'tcx>;
 
  fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {

diff --git a/compiler/rustc_macros/src/type_foldable.rs b/compiler/rustc_macros/src/type_foldable.rs
@@ -17,13 +17,13 @@ pub fn type_foldable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::
  vi.construct(|_, index| {
  let bind = &bindings[index];
  quote! {
- ::rustc_middle::ty::fold::TypeFoldable::try_fold_with(#bind, __folder)?
+ ::rustc_middle::ty::fold::ir::TypeFoldable::try_fold_with(#bind, __folder)?
  }
  })
  });
 
  s.bound_impl(
- quote!(::rustc_middle::ty::fold::TypeFoldable<'tcx>),
+ quote!(::rustc_middle::ty::fold::ir::TypeFoldable<'tcx>),
  quote! {
  fn try_fold_with<__F: ::rustc_middle::ty::fold::FallibleTypeFolder<'tcx>>(
  self,

diff --git a/compiler/rustc_macros/src/type_visitable.rs b/compiler/rustc_macros/src/type_visitable.rs
@@ -13,13 +13,13 @@ pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
  s.add_bounds(synstructure::AddBounds::Generics);
  let body_visit = s.each(|bind| {
  quote! {
- ::rustc_middle::ty::visit::TypeVisitable::visit_with(#bind, __visitor)?;
+ ::rustc_middle::ty::visit::ir::TypeVisitable::visit_with(#bind, __visitor)?;
  }
  });
  s.bind_with(|_| synstructure::BindStyle::Move);
 
  s.bound_impl(
- quote!(::rustc_middle::ty::visit::TypeVisitable<'tcx>),
+ quote!(::rustc_middle::ty::visit::ir::TypeVisitable<'tcx>),
  quote! {
  fn visit_with<__V: ::rustc_middle::ty::visit::TypeVisitor<'tcx>>(
  &self,

diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
@@ -42,7 +42,7 @@ pub struct Canonical<'tcx, V> {
 
 pub type CanonicalVarInfos<'tcx> = &'tcx List<CanonicalVarInfo<'tcx>>;
 
-impl<'tcx> ty::TypeFoldable<'tcx> for CanonicalVarInfos<'tcx> {
+impl<'tcx> ty::ir::TypeFoldable<'tcx> for CanonicalVarInfos<'tcx> {
  fn try_fold_with<F: ty::FallibleTypeFolder<'tcx>>(
  self,
  folder: &mut F,

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
@@ -60,6 +60,7 @@
 #![feature(yeet_expr)]
 #![feature(result_option_inspect)]
 #![feature(const_option)]
+#![feature(trait_alias)]
 #![recursion_limit = "512"]
 #![allow(rustc::potential_query_instability)]