Merging upstream version 1.69.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 115 insertions, 104 deletions

diff --git a/compiler/rustc_traits/src/chalk/db.rs b/compiler/rustc_traits/src/chalk/db.rs
index f146de396..f8c8f744e 100644
--- a/compiler/rustc_traits/src/chalk/db.rs
+++ b/compiler/rustc_traits/src/chalk/db.rs
@@ -246,7 +246,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
 
         // Grab the ADT and the param we might need to calculate its layout
         let param_env = tcx.param_env(did);
-        let adt_ty = tcx.type_of(did);
+        let adt_ty = tcx.type_of(did).subst_identity();
 
         // The ADT is a 1-zst if it's a ZST and its alignment is 1.
         // Mark the ADT as _not_ a 1-zst if there was a layout error.
@@ -269,7 +269,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
 
         let where_clauses = self.where_clauses_for(def_id, bound_vars);
 
-        let sig = self.interner.tcx.bound_fn_sig(def_id);
+        let sig = self.interner.tcx.fn_sig(def_id);
         let (inputs_and_output, iobinders, _) = crate::chalk::lowering::collect_bound_vars(
             self.interner,
             self.interner.tcx,
@@ -468,7 +468,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
         let ty = self
             .interner
             .tcx
-            .bound_type_of(def_id)
+            .type_of(def_id)
             .subst(self.interner.tcx, bound_vars)
             .lower_into(self.interner);
 
@@ -580,7 +580,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
     }
 
     fn is_object_safe(&self, trait_id: chalk_ir::TraitId<RustInterner<'tcx>>) -> bool {
-        self.interner.tcx.is_object_safe(trait_id.0)
+        self.interner.tcx.check_is_object_safe(trait_id.0)
     }
 
     fn hidden_opaque_type(
@@ -588,10 +588,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
         _id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>,
     ) -> chalk_ir::Ty<RustInterner<'tcx>> {
         // FIXME(chalk): actually get hidden ty
-        self.interner
-            .tcx
-            .mk_ty(ty::Tuple(self.interner.tcx.intern_type_list(&[])))
-            .lower_into(self.interner)
+        self.interner.tcx.types.unit.lower_into(self.interner)
     }
 
     fn closure_kind(
@@ -721,13 +718,13 @@ impl<'tcx> chalk_ir::UnificationDatabase<RustInterner<'tcx>> for RustIrDatabase<
 fn bound_vars_for_item(tcx: TyCtxt<'_>, def_id: DefId) -> SubstsRef<'_> {
     InternalSubsts::for_item(tcx, def_id, |param, substs| match param.kind {
         ty::GenericParamDefKind::Type { .. } => tcx
-            .mk_ty(ty::Bound(
+            .mk_bound(
                 ty::INNERMOST,
                 ty::BoundTy {
                     var: ty::BoundVar::from(param.index),
-                    kind: ty::BoundTyKind::Param(param.name),
+                    kind: ty::BoundTyKind::Param(param.def_id, param.name),
                 },
-            ))
+            )
             .into(),
 
         ty::GenericParamDefKind::Lifetime => {
@@ -735,13 +732,13 @@ fn bound_vars_for_item(tcx: TyCtxt<'_>, def_id: DefId) -> SubstsRef<'_> {
                 var: ty::BoundVar::from_usize(substs.len()),
                 kind: ty::BrAnon(substs.len() as u32, None),
             };
-            tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)).into()
+            tcx.mk_re_late_bound(ty::INNERMOST, br).into()
         }
 
         ty::GenericParamDefKind::Const { .. } => tcx
             .mk_const(
                 ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from(param.index)),
-                tcx.type_of(param.def_id),
+                tcx.type_of(param.def_id).subst_identity(),
             )
             .into(),
     })
@@ -772,12 +769,12 @@ struct ReplaceOpaqueTyFolder<'tcx> {
     binder_index: ty::DebruijnIndex,
 }
 
-impl<'tcx> ty::TypeFolder<'tcx> for ReplaceOpaqueTyFolder<'tcx> {
-    fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for ReplaceOpaqueTyFolder<'tcx> {
+    fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -790,10 +787,9 @@ impl<'tcx> ty::TypeFolder<'tcx> for ReplaceOpaqueTyFolder<'tcx> {
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
         if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) = *ty.kind() {
             if def_id == self.opaque_ty_id.0 && substs == self.identity_substs {
-                return self.tcx.mk_ty(ty::Bound(
-                    self.binder_index,
-                    ty::BoundTy::from(ty::BoundVar::from_u32(0)),
-                ));
+                return self
+                    .tcx
+                    .mk_bound(self.binder_index, ty::BoundTy::from(ty::BoundVar::from_u32(0)));
             }
         }
         ty
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 9712abb70..60e22d100 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -62,7 +62,9 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Substitution<RustInterner<'tcx>>> for Subst
 
 impl<'tcx> LowerInto<'tcx, SubstsRef<'tcx>> for &chalk_ir::Substitution<RustInterner<'tcx>> {
     fn lower_into(self, interner: RustInterner<'tcx>) -> SubstsRef<'tcx> {
-        interner.tcx.mk_substs(self.iter(interner).map(|subst| subst.lower_into(interner)))
+        interner
+            .tcx
+            .mk_substs_from_iter(self.iter(interner).map(|subst| subst.lower_into(interner)))
     }
 }
 
@@ -116,6 +118,8 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
                     )),
                 },
                 ty::PredicateKind::ObjectSafe(..)
+                | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
+                | ty::PredicateKind::AliasEq(..)
                 | ty::PredicateKind::ClosureKind(..)
                 | ty::PredicateKind::Subtype(..)
                 | ty::PredicateKind::Coerce(..)
@@ -210,6 +214,8 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi
             // We can defer this, but ultimately we'll want to express
             // some of these in terms of chalk operations.
             ty::PredicateKind::ClosureKind(..)
+            | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
+            | ty::PredicateKind::AliasEq(..)
             | ty::PredicateKind::Coerce(..)
             | ty::PredicateKind::ConstEvaluatable(..)
             | ty::PredicateKind::Ambiguous
@@ -343,6 +349,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Ty<RustInterner<'tcx>>> for Ty<'tcx> {
                 substs.lower_into(interner),
             ),
             ty::GeneratorWitness(_) => unimplemented!(),
+            ty::GeneratorWitnessMIR(..) => unimplemented!(),
             ty::Never => chalk_ir::TyKind::Never,
             ty::Tuple(types) => {
                 chalk_ir::TyKind::Tuple(types.len(), types.as_substs().lower_into(interner))
@@ -369,7 +376,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Ty<RustInterner<'tcx>>> for Ty<'tcx> {
             ty::Placeholder(_placeholder) => {
                 chalk_ir::TyKind::Placeholder(chalk_ir::PlaceholderIndex {
                     ui: chalk_ir::UniverseIndex { counter: _placeholder.universe.as_usize() },
-                    idx: _placeholder.name.as_usize(),
+                    idx: _placeholder.name.expect_anon() as usize,
                 })
             }
             ty::Infer(_infer) => unimplemented!(),
@@ -450,11 +457,7 @@ impl<'tcx> LowerInto<'tcx, Ty<'tcx>> for &chalk_ir::Ty<RustInterner<'tcx>> {
                 interner.tcx.mk_alias_ty(assoc_ty.0, substitution.lower_into(interner)),
             ),
             TyKind::Foreign(def_id) => ty::Foreign(def_id.0),
-            TyKind::Error => return interner.tcx.ty_error(),
-            TyKind::Placeholder(placeholder) => ty::Placeholder(ty::Placeholder {
-                universe: ty::UniverseIndex::from_usize(placeholder.ui.counter),
-                name: ty::BoundVar::from_usize(placeholder.idx),
-            }),
+            TyKind::Error => return interner.tcx.ty_error_misc(),
             TyKind::Alias(alias_ty) => match alias_ty {
                 chalk_ir::AliasTy::Projection(projection) => ty::Alias(
                     ty::Projection,
@@ -472,17 +475,21 @@ impl<'tcx> LowerInto<'tcx, Ty<'tcx>> for &chalk_ir::Ty<RustInterner<'tcx>> {
                 ),
             },
             TyKind::Function(_quantified_ty) => unimplemented!(),
-            TyKind::BoundVar(_bound) => ty::Bound(
-                ty::DebruijnIndex::from_usize(_bound.debruijn.depth() as usize),
+            TyKind::BoundVar(bound) => ty::Bound(
+                ty::DebruijnIndex::from_usize(bound.debruijn.depth() as usize),
                 ty::BoundTy {
-                    var: ty::BoundVar::from_usize(_bound.index),
-                    kind: ty::BoundTyKind::Anon,
+                    var: ty::BoundVar::from_usize(bound.index),
+                    kind: ty::BoundTyKind::Anon(bound.index as u32),
                 },
             ),
+            TyKind::Placeholder(placeholder) => ty::Placeholder(ty::Placeholder {
+                universe: ty::UniverseIndex::from_usize(placeholder.ui.counter),
+                name: ty::BoundTyKind::Anon(placeholder.idx as u32),
+            }),
             TyKind::InferenceVar(_, _) => unimplemented!(),
             TyKind::Dyn(_) => unimplemented!(),
         };
-        interner.tcx.mk_ty(kind)
+        interner.tcx.mk_ty_from_kind(kind)
     }
 }
 
@@ -492,6 +499,9 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Lifetime<RustInterner<'tcx>>> for Region<'t
             ty::ReEarlyBound(_) => {
                 panic!("Should have already been substituted.");
             }
+            ty::ReError(_) => {
+                panic!("Error lifetime should not have already been lowered.");
+            }
             ty::ReLateBound(db, br) => chalk_ir::LifetimeData::BoundVar(chalk_ir::BoundVar::new(
                 chalk_ir::DebruijnIndex::new(db.as_u32()),
                 br.var.as_usize(),
@@ -503,7 +513,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Lifetime<RustInterner<'tcx>>> for Region<'t
             ty::RePlaceholder(placeholder_region) => {
                 chalk_ir::LifetimeData::Placeholder(chalk_ir::PlaceholderIndex {
                     ui: chalk_ir::UniverseIndex { counter: placeholder_region.universe.index() },
-                    idx: 0,
+                    idx: 0, // FIXME: This `idx: 0` is sus.
                 })
                 .intern(interner)
             }
@@ -514,8 +524,9 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Lifetime<RustInterner<'tcx>>> for Region<'t
 
 impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'tcx>> {
     fn lower_into(self, interner: RustInterner<'tcx>) -> Region<'tcx> {
-        let kind = match self.data(interner) {
-            chalk_ir::LifetimeData::BoundVar(var) => ty::ReLateBound(
+        let tcx = interner.tcx;
+        match self.data(interner) {
+            chalk_ir::LifetimeData::BoundVar(var) => tcx.mk_re_late_bound(
                 ty::DebruijnIndex::from_u32(var.debruijn.depth()),
                 ty::BoundRegion {
                     var: ty::BoundVar::from_usize(var.index),
@@ -523,15 +534,14 @@ impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'t
                 },
             ),
             chalk_ir::LifetimeData::InferenceVar(_var) => unimplemented!(),
-            chalk_ir::LifetimeData::Placeholder(p) => ty::RePlaceholder(ty::Placeholder {
+            chalk_ir::LifetimeData::Placeholder(p) => tcx.mk_re_placeholder(ty::Placeholder {
                 universe: ty::UniverseIndex::from_usize(p.ui.counter),
                 name: ty::BoundRegionKind::BrAnon(p.idx as u32, None),
             }),
-            chalk_ir::LifetimeData::Static => return interner.tcx.lifetimes.re_static,
-            chalk_ir::LifetimeData::Erased => return interner.tcx.lifetimes.re_erased,
+            chalk_ir::LifetimeData::Static => tcx.lifetimes.re_static,
+            chalk_ir::LifetimeData::Erased => tcx.lifetimes.re_erased,
             chalk_ir::LifetimeData::Phantom(void, _) => match *void {},
-        };
-        interner.tcx.mk_region(kind)
+        }
     }
 }
 
@@ -639,8 +649,10 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'
                 Some(chalk_ir::WhereClause::AliasEq(predicate.lower_into(interner)))
             }
             ty::PredicateKind::WellFormed(_ty) => None,
+            ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
             ty::PredicateKind::ObjectSafe(..)
+            | ty::PredicateKind::AliasEq(..)
             | ty::PredicateKind::ClosureKind(..)
             | ty::PredicateKind::Subtype(..)
             | ty::PredicateKind::Coerce(..)
@@ -670,11 +682,11 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Binders<chalk_ir::QuantifiedWhereClauses<Ru
         // shifted in by one so that they are still escaping.
         let predicates = ty::fold::shift_vars(interner.tcx, self, 1);
 
-        let self_ty = interner.tcx.mk_ty(ty::Bound(
+        let self_ty = interner.tcx.mk_bound(
             // This is going to be wrapped in a binder
             ty::DebruijnIndex::from_usize(1),
-            ty::BoundTy { var: ty::BoundVar::from_usize(0), kind: ty::BoundTyKind::Anon },
-        ));
+            ty::BoundTy { var: ty::BoundVar::from_usize(0), kind: ty::BoundTyKind::Anon(0) },
+        );
         let where_clauses = predicates.into_iter().map(|predicate| {
             let (predicate, binders, _named_regions) =
                 collect_bound_vars(interner, interner.tcx, predicate);
@@ -772,8 +784,10 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<Ru
             }
             ty::PredicateKind::Clause(ty::Clause::TypeOutlives(_predicate)) => None,
             ty::PredicateKind::WellFormed(_ty) => None,
+            ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
             ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
+            | ty::PredicateKind::AliasEq(..)
             | ty::PredicateKind::ObjectSafe(..)
             | ty::PredicateKind::ClosureKind(..)
             | ty::PredicateKind::Subtype(..)
@@ -867,7 +881,7 @@ impl<'tcx> LowerInto<'tcx, chalk_solve::rust_ir::AliasEqBound<RustInterner<'tcx>
 /// It's important to note that because of prior substitution, we may have
 /// late-bound regions, even outside of fn contexts, since this is the best way
 /// to prep types for chalk lowering.
-pub(crate) fn collect_bound_vars<'tcx, T: TypeFoldable<'tcx>>(
+pub(crate) fn collect_bound_vars<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>(
     interner: RustInterner<'tcx>,
     tcx: TyCtxt<'tcx>,
     ty: Binder<'tcx, T>,
@@ -917,8 +931,8 @@ impl<'tcx> BoundVarsCollector<'tcx> {
     }
 }
 
-impl<'tcx> TypeVisitor<'tcx> for BoundVarsCollector<'tcx> {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for BoundVarsCollector<'tcx> {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -998,12 +1012,15 @@ impl<'a, 'tcx> NamedBoundVarSubstitutor<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> TypeFolder<'tcx> for NamedBoundVarSubstitutor<'a, 'tcx> {
-    fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for NamedBoundVarSubstitutor<'a, 'tcx> {
+    fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T> {
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+        &mut self,
+        t: Binder<'tcx, T>,
+    ) -> Binder<'tcx, T> {
         self.binder_index.shift_in(1);
         let result = t.super_fold_with(self);
         self.binder_index.shift_out(1);
@@ -1016,7 +1033,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for NamedBoundVarSubstitutor<'a, 'tcx> {
                 ty::BrNamed(def_id, _name) => match self.named_parameters.get(&def_id) {
                     Some(idx) => {
                         let new_br = ty::BoundRegion { var: br.var, kind: ty::BrAnon(*idx, None) };
-                        return self.tcx.mk_region(ty::ReLateBound(index, new_br));
+                        return self.tcx.mk_re_late_bound(index, new_br);
                     }
                     None => panic!("Missing `BrNamed`."),
                 },
@@ -1037,7 +1054,7 @@ pub(crate) struct ParamsSubstitutor<'tcx> {
     binder_index: ty::DebruijnIndex,
     list: Vec<rustc_middle::ty::ParamTy>,
     next_ty_placeholder: usize,
-    pub(crate) params: rustc_data_structures::fx::FxHashMap<usize, rustc_middle::ty::ParamTy>,
+    pub(crate) params: rustc_data_structures::fx::FxHashMap<u32, rustc_middle::ty::ParamTy>,
     pub(crate) named_regions: BTreeMap<DefId, u32>,
 }
 
@@ -1054,12 +1071,15 @@ impl<'tcx> ParamsSubstitutor<'tcx> {
     }
 }
 
-impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
-    fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ParamsSubstitutor<'tcx> {
+    fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T> {
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+        &mut self,
+        t: Binder<'tcx, T>,
+    ) -> Binder<'tcx, T> {
         self.binder_index.shift_in(1);
         let result = t.super_fold_with(self);
         self.binder_index.shift_out(1);
@@ -1069,18 +1089,18 @@ impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
         match *t.kind() {
             ty::Param(param) => match self.list.iter().position(|r| r == &param) {
-                Some(idx) => self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType {
+                Some(idx) => self.tcx.mk_placeholder(ty::PlaceholderType {
                     universe: ty::UniverseIndex::from_usize(0),
-                    name: ty::BoundVar::from_usize(idx),
-                })),
+                    name: ty::BoundTyKind::Anon(idx as u32),
+                }),
                 None => {
                     self.list.push(param);
                     let idx = self.list.len() - 1 + self.next_ty_placeholder;
-                    self.params.insert(idx, param);
-                    self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType {
+                    self.params.insert(idx as u32, param);
+                    self.tcx.mk_placeholder(ty::PlaceholderType {
                         universe: ty::UniverseIndex::from_usize(0),
-                        name: ty::BoundVar::from_usize(idx),
-                    }))
+                        name: ty::BoundTyKind::Anon(idx as u32),
+                    })
                 }
             },
             _ => t.super_fold_with(self),
@@ -1098,7 +1118,7 @@ impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
                         var: ty::BoundVar::from_u32(*idx),
                         kind: ty::BrAnon(*idx, None),
                     };
-                    self.tcx.mk_region(ty::ReLateBound(self.binder_index, br))
+                    self.tcx.mk_re_late_bound(self.binder_index, br)
                 }
                 None => {
                     let idx = self.named_regions.len() as u32;
@@ -1107,7 +1127,7 @@ impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
                         kind: ty::BrAnon(idx, None),
                     };
                     self.named_regions.insert(_re.def_id, idx);
-                    self.tcx.mk_region(ty::ReLateBound(self.binder_index, br))
+                    self.tcx.mk_re_late_bound(self.binder_index, br)
                 }
             },
 
@@ -1118,28 +1138,28 @@ impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
 
 pub(crate) struct ReverseParamsSubstitutor<'tcx> {
     tcx: TyCtxt<'tcx>,
-    params: rustc_data_structures::fx::FxHashMap<usize, rustc_middle::ty::ParamTy>,
+    params: rustc_data_structures::fx::FxHashMap<u32, rustc_middle::ty::ParamTy>,
 }
 
 impl<'tcx> ReverseParamsSubstitutor<'tcx> {
     pub(crate) fn new(
         tcx: TyCtxt<'tcx>,
-        params: rustc_data_structures::fx::FxHashMap<usize, rustc_middle::ty::ParamTy>,
+        params: rustc_data_structures::fx::FxHashMap<u32, rustc_middle::ty::ParamTy>,
     ) -> Self {
         Self { tcx, params }
     }
 }
 
-impl<'tcx> TypeFolder<'tcx> for ReverseParamsSubstitutor<'tcx> {
-    fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
+impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ReverseParamsSubstitutor<'tcx> {
+    fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
         match *t.kind() {
             ty::Placeholder(ty::PlaceholderType { universe: ty::UniverseIndex::ROOT, name }) => {
-                match self.params.get(&name.as_usize()) {
-                    Some(param) => self.tcx.mk_ty(ty::Param(*param)),
+                match self.params.get(&name.expect_anon()) {
+                    Some(&ty::ParamTy { index, name }) => self.tcx.mk_ty_param(index, name),
                     None => t,
                 }
             }
@@ -1166,11 +1186,12 @@ impl PlaceholdersCollector {
     }
 }
 
-impl<'tcx> TypeVisitor<'tcx> for PlaceholdersCollector {
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for PlaceholdersCollector {
     fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
         match t.kind() {
             ty::Placeholder(p) if p.universe == self.universe_index => {
-                self.next_ty_placeholder = self.next_ty_placeholder.max(p.name.as_usize() + 1);
+                self.next_ty_placeholder =
+                    self.next_ty_placeholder.max(p.name.expect_anon() as usize + 1);
             }
 
             _ => (),
@@ -1185,6 +1206,7 @@ impl<'tcx> TypeVisitor<'tcx> for PlaceholdersCollector {
                 if let ty::BoundRegionKind::BrAnon(anon, _) = p.name {
                     self.next_anon_region_placeholder = self.next_anon_region_placeholder.max(anon);
                 }
+                // FIXME: This doesn't seem to handle BrNamed at all?
             }
 
             _ => (),
diff --git a/compiler/rustc_traits/src/chalk/mod.rs b/compiler/rustc_traits/src/chalk/mod.rs
index f76386fa7..a5ebc26a8 100644
--- a/compiler/rustc_traits/src/chalk/mod.rs
+++ b/compiler/rustc_traits/src/chalk/mod.rs
@@ -6,15 +6,10 @@
 pub(crate) mod db;
 pub(crate) mod lowering;
 
-use rustc_data_structures::fx::FxHashMap;
-
-use rustc_index::vec::IndexVec;
-
 use rustc_middle::infer::canonical::{CanonicalTyVarKind, CanonicalVarKind};
 use rustc_middle::traits::ChalkRustInterner;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::subst::GenericArg;
-use rustc_middle::ty::{self, BoundVar, ParamTy, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeFoldable, TypeVisitable};
 
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalVarValues, Certainty, QueryRegionConstraints, QueryResponse,
@@ -44,7 +39,7 @@ pub(crate) fn evaluate_goal<'tcx>(
     let mut params_substitutor =
         ParamsSubstitutor::new(tcx, placeholders_collector.next_ty_placeholder);
     let obligation = obligation.fold_with(&mut params_substitutor);
-    let params: FxHashMap<usize, ParamTy> = params_substitutor.params;
+    let params = params_substitutor.params;
 
     let max_universe = obligation.max_universe.index();
 
@@ -100,36 +95,35 @@ pub(crate) fn evaluate_goal<'tcx>(
                          binders: chalk_ir::CanonicalVarKinds<_>| {
         use rustc_middle::infer::canonical::CanonicalVarInfo;
 
-        let mut var_values: IndexVec<BoundVar, GenericArg<'tcx>> = IndexVec::new();
         let mut reverse_param_substitutor = ReverseParamsSubstitutor::new(tcx, params);
-        subst.as_slice(interner).iter().for_each(|p| {
-            var_values.push(p.lower_into(interner).fold_with(&mut reverse_param_substitutor));
-        });
-        let variables: Vec<_> = binders
-            .iter(interner)
-            .map(|var| {
-                let kind = match var.kind {
-                    chalk_ir::VariableKind::Ty(ty_kind) => CanonicalVarKind::Ty(match ty_kind {
-                        chalk_ir::TyVariableKind::General => CanonicalTyVarKind::General(
-                            ty::UniverseIndex::from_usize(var.skip_kind().counter),
-                        ),
-                        chalk_ir::TyVariableKind::Integer => CanonicalTyVarKind::Int,
-                        chalk_ir::TyVariableKind::Float => CanonicalTyVarKind::Float,
-                    }),
-                    chalk_ir::VariableKind::Lifetime => CanonicalVarKind::Region(
+        let var_values = tcx.mk_substs_from_iter(
+            subst
+                .as_slice(interner)
+                .iter()
+                .map(|p| p.lower_into(interner).fold_with(&mut reverse_param_substitutor)),
+        );
+        let variables = binders.iter(interner).map(|var| {
+            let kind = match var.kind {
+                chalk_ir::VariableKind::Ty(ty_kind) => CanonicalVarKind::Ty(match ty_kind {
+                    chalk_ir::TyVariableKind::General => CanonicalTyVarKind::General(
                         ty::UniverseIndex::from_usize(var.skip_kind().counter),
                     ),
-                    // FIXME(compiler-errors): We don't currently have a way of turning
-                    // a Chalk ty back into a rustc ty, right?
-                    chalk_ir::VariableKind::Const(_) => todo!(),
-                };
-                CanonicalVarInfo { kind }
-            })
-            .collect();
+                    chalk_ir::TyVariableKind::Integer => CanonicalTyVarKind::Int,
+                    chalk_ir::TyVariableKind::Float => CanonicalTyVarKind::Float,
+                }),
+                chalk_ir::VariableKind::Lifetime => {
+                    CanonicalVarKind::Region(ty::UniverseIndex::from_usize(var.skip_kind().counter))
+                }
+                // FIXME(compiler-errors): We don't currently have a way of turning
+                // a Chalk ty back into a rustc ty, right?
+                chalk_ir::VariableKind::Const(_) => todo!(),
+            };
+            CanonicalVarInfo { kind }
+        });
         let max_universe = binders.iter(interner).map(|v| v.skip_kind().counter).max().unwrap_or(0);
         let sol = Canonical {
             max_universe: ty::UniverseIndex::from_usize(max_universe),
-            variables: tcx.intern_canonical_var_infos(&variables),
+            variables: tcx.mk_canonical_var_infos_from_iter(variables),
             value: QueryResponse {
                 var_values: CanonicalVarValues { var_values },
                 region_constraints: QueryRegionConstraints::default(),
@@ -159,8 +153,7 @@ pub(crate) fn evaluate_goal<'tcx>(
                             max_universe: ty::UniverseIndex::from_usize(0),
                             variables: obligation.variables,
                             value: QueryResponse {
-                                var_values: CanonicalVarValues { var_values: IndexVec::new() }
-                                    .make_identity(tcx),
+                                var_values: CanonicalVarValues::dummy(),
                                 region_constraints: QueryRegionConstraints::default(),
                                 certainty: Certainty::Ambiguous,
                                 opaque_types: vec![],