Rollup merge of #146111 - ChayimFriedman2:more-ns-specific-defid, r=lcnr

Migrate more things in the new solver to specific `DefId`s

Continuation of https://github.com/rust-lang/rust/pull/145377. I migrated the rest of the types, except aliases.

Aliases are problematic because opaques and associated types share the same type in the new solver. `@jackh726,` `@lcnr,` `@ShoyuVanilla` I'd like to hear ideas here. Anyway, even if we do nothing with them we already got a substantial improvement.

r? types

17 files changed, 154 insertions, 80 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 97c8a0336c2..de6fa4c344e 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -52,7 +52,7 @@ use rustc_session::{Limit, Session};
 use rustc_span::def_id::{CRATE_DEF_ID, DefPathHash, StableCrateId};
 use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
 use rustc_type_ir::TyKind::*;
-use rustc_type_ir::lang_items::{SolverLangItem, SolverTraitLangItem};
+use rustc_type_ir::lang_items::{SolverAdtLangItem, SolverLangItem, SolverTraitLangItem};
 pub use rustc_type_ir::lift::Lift;
 use rustc_type_ir::{
     CollectAndApply, Interner, TypeFlags, TypeFoldable, WithCachedTypeInfo, elaborate, search_graph,
@@ -94,6 +94,13 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type DefId = DefId;
     type LocalDefId = LocalDefId;
     type TraitId = DefId;
+    type ForeignId = DefId;
+    type FunctionId = DefId;
+    type ClosureId = DefId;
+    type CoroutineClosureId = DefId;
+    type CoroutineId = DefId;
+    type AdtId = DefId;
+    type ImplId = DefId;
     type Span = Span;
 
     type GenericArgs = ty::GenericArgsRef<'tcx>;
@@ -492,6 +499,10 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         self.require_lang_item(solver_trait_lang_item_to_lang_item(lang_item), DUMMY_SP)
     }
 
+    fn require_adt_lang_item(self, lang_item: SolverAdtLangItem) -> DefId {
+        self.require_lang_item(solver_adt_lang_item_to_lang_item(lang_item), DUMMY_SP)
+    }
+
     fn is_lang_item(self, def_id: DefId, lang_item: SolverLangItem) -> bool {
         self.is_lang_item(def_id, solver_lang_item_to_lang_item(lang_item))
     }
@@ -500,6 +511,10 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         self.is_lang_item(def_id, solver_trait_lang_item_to_lang_item(lang_item))
     }
 
+    fn is_adt_lang_item(self, def_id: DefId, lang_item: SolverAdtLangItem) -> bool {
+        self.is_lang_item(def_id, solver_adt_lang_item_to_lang_item(lang_item))
+    }
+
     fn is_default_trait(self, def_id: DefId) -> bool {
         self.is_default_trait(def_id)
     }
@@ -512,6 +527,10 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         lang_item_to_solver_trait_lang_item(self.lang_items().from_def_id(def_id)?)
     }
 
+    fn as_adt_lang_item(self, def_id: DefId) -> Option<SolverAdtLangItem> {
+        lang_item_to_solver_adt_lang_item(self.lang_items().from_def_id(def_id)?)
+    }
+
     fn associated_type_def_ids(self, def_id: DefId) -> impl IntoIterator<Item = DefId> {
         self.associated_items(def_id)
             .in_definition_order()
@@ -783,6 +802,13 @@ bidirectional_lang_item_map! {
     DynMetadata,
     FutureOutput,
     Metadata,
+// tidy-alphabetical-end
+}
+
+bidirectional_lang_item_map! {
+    SolverAdtLangItem, lang_item_to_solver_adt_lang_item, solver_adt_lang_item_to_lang_item;
+
+// tidy-alphabetical-start
     Option,
     Poll,
 // tidy-alphabetical-end
diff --git a/compiler/rustc_next_trait_solver/src/coherence.rs b/compiler/rustc_next_trait_solver/src/coherence.rs
index 79219b34e29..b949deb1192 100644
--- a/compiler/rustc_next_trait_solver/src/coherence.rs
+++ b/compiler/rustc_next_trait_solver/src/coherence.rs
@@ -435,7 +435,21 @@ where
                 }
             }
             ty::Error(_) => ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty)),
-            ty::Closure(did, ..) | ty::CoroutineClosure(did, ..) | ty::Coroutine(did, ..) => {
+            ty::Closure(did, ..) => {
+                if self.def_id_is_local(did) {
+                    ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
+                } else {
+                    self.found_non_local_ty(ty)
+                }
+            }
+            ty::CoroutineClosure(did, ..) => {
+                if self.def_id_is_local(did) {
+                    ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
+                } else {
+                    self.found_non_local_ty(ty)
+                }
+            }
+            ty::Coroutine(did, ..) => {
                 if self.def_id_is_local(did) {
                     ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
                 } else {
diff --git a/compiler/rustc_next_trait_solver/src/delegate.rs b/compiler/rustc_next_trait_solver/src/delegate.rs
index 7b932010d49..a7ecbfcb7c4 100644
--- a/compiler/rustc_next_trait_solver/src/delegate.rs
+++ b/compiler/rustc_next_trait_solver/src/delegate.rs
@@ -76,7 +76,7 @@ pub trait SolverDelegate: Deref<Target = Self::Infcx> + Sized {
         &self,
         goal_trait_ref: ty::TraitRef<Self::Interner>,
         trait_assoc_def_id: <Self::Interner as Interner>::DefId,
-        impl_def_id: <Self::Interner as Interner>::DefId,
+        impl_def_id: <Self::Interner as Interner>::ImplId,
     ) -> Result<
         Option<<Self::Interner as Interner>::DefId>,
         <Self::Interner as Interner>::ErrorGuaranteed,
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index be7e4dd4cda..e3cf0330b14 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -186,7 +186,7 @@ where
     fn consider_impl_candidate(
         ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, Self>,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
     ) -> Result<Candidate<I>, NoSolution>;
 
     /// If the predicate contained an error, we want to avoid emitting unnecessary trait
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
index 7c5940828da..f6eab286ba7 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
@@ -605,7 +605,7 @@ fn coroutine_closure_to_certain_coroutine<I: Interner>(
     cx: I,
     goal_kind: ty::ClosureKind,
     goal_region: I::Region,
-    def_id: I::DefId,
+    def_id: I::CoroutineClosureId,
     args: ty::CoroutineClosureArgs<I>,
     sig: ty::CoroutineClosureSignature<I>,
 ) -> I::Ty {
@@ -629,7 +629,7 @@ fn coroutine_closure_to_ambiguous_coroutine<I: Interner>(
     cx: I,
     goal_kind: ty::ClosureKind,
     goal_region: I::Region,
-    def_id: I::DefId,
+    def_id: I::CoroutineClosureId,
     args: ty::CoroutineClosureArgs<I>,
     sig: ty::CoroutineClosureSignature<I>,
 ) -> I::Ty {
@@ -664,7 +664,7 @@ fn coroutine_closure_to_ambiguous_coroutine<I: Interner>(
 pub(in crate::solve) fn extract_fn_def_from_const_callable<I: Interner>(
     cx: I,
     self_ty: I::Ty,
-) -> Result<(ty::Binder<I, (I::FnInputTys, I::Ty)>, I::DefId, I::GenericArgs), NoSolution> {
+) -> Result<(ty::Binder<I, (I::FnInputTys, I::Ty)>, I::FunctionId, I::GenericArgs), NoSolution> {
     match self_ty.kind() {
         ty::FnDef(def_id, args) => {
             let sig = cx.fn_sig(def_id);
diff --git a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
index 229345065b1..6646857a136 100644
--- a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
@@ -123,7 +123,7 @@ where
     fn consider_impl_candidate(
         ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, Self>,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
     ) -> Result<Candidate<I>, NoSolution> {
         let cx = ecx.cx();
 
@@ -152,20 +152,20 @@ where
         }
 
         ecx.probe_trait_candidate(CandidateSource::Impl(impl_def_id)).enter(|ecx| {
-            let impl_args = ecx.fresh_args_for_item(impl_def_id);
+            let impl_args = ecx.fresh_args_for_item(impl_def_id.into());
             ecx.record_impl_args(impl_args);
             let impl_trait_ref = impl_trait_ref.instantiate(cx, impl_args);
 
             ecx.eq(goal.param_env, goal.predicate.trait_ref, impl_trait_ref)?;
             let where_clause_bounds = cx
-                .predicates_of(impl_def_id)
+                .predicates_of(impl_def_id.into())
                 .iter_instantiated(cx, impl_args)
                 .map(|pred| goal.with(cx, pred));
             ecx.add_goals(GoalSource::ImplWhereBound, where_clause_bounds);
 
             // For this impl to be `const`, we need to check its `[const]` bounds too.
             let const_conditions = cx
-                .const_conditions(impl_def_id)
+                .const_conditions(impl_def_id.into())
                 .iter_instantiated(cx, impl_args)
                 .map(|bound_trait_ref| {
                     goal.with(
@@ -240,7 +240,7 @@ where
             ty::TraitRef::new(cx, cx.require_trait_lang_item(SolverTraitLangItem::Sized), [output])
         });
         let requirements = cx
-            .const_conditions(def_id)
+            .const_conditions(def_id.into())
             .iter_instantiated(cx, args)
             .map(|trait_ref| {
                 (
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
index 443aebbdb4d..99aa9bef5ac 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
@@ -1092,7 +1092,7 @@ where
         &self,
         goal_trait_ref: ty::TraitRef<I>,
         trait_assoc_def_id: I::DefId,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
     ) -> Result<Option<I::DefId>, I::ErrorGuaranteed> {
         self.delegate.fetch_eligible_assoc_item(goal_trait_ref, trait_assoc_def_id, impl_def_id)
     }
diff --git a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
index cfdf2007391..6e6be829f52 100644
--- a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
@@ -5,7 +5,7 @@ mod opaque_types;
 
 use rustc_type_ir::fast_reject::DeepRejectCtxt;
 use rustc_type_ir::inherent::*;
-use rustc_type_ir::lang_items::{SolverLangItem, SolverTraitLangItem};
+use rustc_type_ir::lang_items::{SolverAdtLangItem, SolverLangItem, SolverTraitLangItem};
 use rustc_type_ir::solve::SizedTraitKind;
 use rustc_type_ir::{self as ty, Interner, NormalizesTo, PredicateKind, Upcast as _};
 use tracing::instrument;
@@ -193,7 +193,7 @@ where
     fn consider_impl_candidate(
         ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, NormalizesTo<I>>,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
     ) -> Result<Candidate<I>, NoSolution> {
         let cx = ecx.cx();
 
@@ -217,13 +217,13 @@ where
         };
 
         ecx.probe_trait_candidate(CandidateSource::Impl(impl_def_id)).enter(|ecx| {
-            let impl_args = ecx.fresh_args_for_item(impl_def_id);
+            let impl_args = ecx.fresh_args_for_item(impl_def_id.into());
             let impl_trait_ref = impl_trait_ref.instantiate(cx, impl_args);
 
             ecx.eq(goal.param_env, goal_trait_ref, impl_trait_ref)?;
 
             let where_clause_bounds = cx
-                .predicates_of(impl_def_id)
+                .predicates_of(impl_def_id.into())
                 .iter_instantiated(cx, impl_args)
                 .map(|pred| goal.with(cx, pred));
             ecx.add_goals(GoalSource::ImplWhereBound, where_clause_bounds);
@@ -824,10 +824,10 @@ where
             // coroutine yield ty `Poll<Option<I>>`.
             let wrapped_expected_ty = Ty::new_adt(
                 cx,
-                cx.adt_def(cx.require_lang_item(SolverLangItem::Poll)),
+                cx.adt_def(cx.require_adt_lang_item(SolverAdtLangItem::Poll)),
                 cx.mk_args(&[Ty::new_adt(
                     cx,
-                    cx.adt_def(cx.require_lang_item(SolverLangItem::Option)),
+                    cx.adt_def(cx.require_adt_lang_item(SolverAdtLangItem::Option)),
                     cx.mk_args(&[expected_ty.into()]),
                 )
                 .into()]),
@@ -979,7 +979,7 @@ where
     fn translate_args(
         &mut self,
         goal: Goal<I, ty::NormalizesTo<I>>,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
         impl_args: I::GenericArgs,
         impl_trait_ref: rustc_type_ir::TraitRef<I>,
         target_container_def_id: I::DefId,
@@ -988,14 +988,15 @@ where
         Ok(if target_container_def_id == impl_trait_ref.def_id.into() {
             // Default value from the trait definition. No need to rebase.
             goal.predicate.alias.args
-        } else if target_container_def_id == impl_def_id {
+        } else if target_container_def_id == impl_def_id.into() {
             // Same impl, no need to fully translate, just a rebase from
             // the trait is sufficient.
             goal.predicate.alias.args.rebase_onto(cx, impl_trait_ref.def_id.into(), impl_args)
         } else {
             let target_args = self.fresh_args_for_item(target_container_def_id);
-            let target_trait_ref =
-                cx.impl_trait_ref(target_container_def_id).instantiate(cx, target_args);
+            let target_trait_ref = cx
+                .impl_trait_ref(target_container_def_id.try_into().unwrap())
+                .instantiate(cx, target_args);
             // Relate source impl to target impl by equating trait refs.
             self.eq(goal.param_env, impl_trait_ref, target_trait_ref)?;
             // Also add predicates since they may be needed to constrain the
diff --git a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
index cdcfebf2909..3e720a47f32 100644
--- a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
@@ -54,7 +54,7 @@ where
     fn consider_impl_candidate(
         ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, TraitPredicate<I>>,
-        impl_def_id: I::DefId,
+        impl_def_id: I::ImplId,
     ) -> Result<Candidate<I>, NoSolution> {
         let cx = ecx.cx();
 
@@ -91,13 +91,13 @@ where
         };
 
         ecx.probe_trait_candidate(CandidateSource::Impl(impl_def_id)).enter(|ecx| {
-            let impl_args = ecx.fresh_args_for_item(impl_def_id);
+            let impl_args = ecx.fresh_args_for_item(impl_def_id.into());
             ecx.record_impl_args(impl_args);
             let impl_trait_ref = impl_trait_ref.instantiate(cx, impl_args);
 
             ecx.eq(goal.param_env, goal.predicate.trait_ref, impl_trait_ref)?;
             let where_clause_bounds = cx
-                .predicates_of(impl_def_id)
+                .predicates_of(impl_def_id.into())
                 .iter_instantiated(cx, impl_args)
                 .map(|pred| goal.with(cx, pred));
             ecx.add_goals(GoalSource::ImplWhereBound, where_clause_bounds);
diff --git a/compiler/rustc_type_ir/src/fast_reject.rs b/compiler/rustc_type_ir/src/fast_reject.rs
index 5a05630e1bd..ed6416a7f55 100644
--- a/compiler/rustc_type_ir/src/fast_reject.rs
+++ b/compiler/rustc_type_ir/src/fast_reject.rs
@@ -122,7 +122,7 @@ pub fn simplify_type<I: Interner>(
         ty::Int(int_type) => Some(SimplifiedType::Int(int_type)),
         ty::Uint(uint_type) => Some(SimplifiedType::Uint(uint_type)),
         ty::Float(float_type) => Some(SimplifiedType::Float(float_type)),
-        ty::Adt(def, _) => Some(SimplifiedType::Adt(def.def_id())),
+        ty::Adt(def, _) => Some(SimplifiedType::Adt(def.def_id().into())),
         ty::Str => Some(SimplifiedType::Str),
         ty::Array(..) => Some(SimplifiedType::Array),
         ty::Slice(..) => Some(SimplifiedType::Slice),
@@ -135,11 +135,11 @@ pub fn simplify_type<I: Interner>(
             _ => Some(SimplifiedType::MarkerTraitObject),
         },
         ty::Ref(_, _, mutbl) => Some(SimplifiedType::Ref(mutbl)),
-        ty::FnDef(def_id, _) | ty::Closure(def_id, _) | ty::CoroutineClosure(def_id, _) => {
-            Some(SimplifiedType::Closure(def_id))
-        }
-        ty::Coroutine(def_id, _) => Some(SimplifiedType::Coroutine(def_id)),
-        ty::CoroutineWitness(def_id, _) => Some(SimplifiedType::CoroutineWitness(def_id)),
+        ty::FnDef(def_id, _) => Some(SimplifiedType::Closure(def_id.into())),
+        ty::Closure(def_id, _) => Some(SimplifiedType::Closure(def_id.into())),
+        ty::CoroutineClosure(def_id, _) => Some(SimplifiedType::Closure(def_id.into())),
+        ty::Coroutine(def_id, _) => Some(SimplifiedType::Coroutine(def_id.into())),
+        ty::CoroutineWitness(def_id, _) => Some(SimplifiedType::CoroutineWitness(def_id.into())),
         ty::Never => Some(SimplifiedType::Never),
         ty::Tuple(tys) => Some(SimplifiedType::Tuple(tys.len())),
         ty::FnPtr(sig_tys, _hdr) => {
@@ -161,7 +161,7 @@ pub fn simplify_type<I: Interner>(
             }
             TreatParams::AsRigid | TreatParams::InstantiateWithInfer => None,
         },
-        ty::Foreign(def_id) => Some(SimplifiedType::Foreign(def_id)),
+        ty::Foreign(def_id) => Some(SimplifiedType::Foreign(def_id.into())),
         ty::Error(_) => Some(SimplifiedType::Error),
         ty::Bound(..) | ty::Infer(_) => None,
     }
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index 64063b1a365..ecfc05a6e20 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -74,7 +74,7 @@ pub trait Ty<I: Interner<Ty = Self>>:
 
     fn new_adt(interner: I, adt_def: I::AdtDef, args: I::GenericArgs) -> Self;
 
-    fn new_foreign(interner: I, def_id: I::DefId) -> Self;
+    fn new_foreign(interner: I, def_id: I::ForeignId) -> Self;
 
     fn new_dynamic(
         interner: I,
@@ -83,17 +83,21 @@ pub trait Ty<I: Interner<Ty = Self>>:
         kind: ty::DynKind,
     ) -> Self;
 
-    fn new_coroutine(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
+    fn new_coroutine(interner: I, def_id: I::CoroutineId, args: I::GenericArgs) -> Self;
 
-    fn new_coroutine_closure(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
+    fn new_coroutine_closure(
+        interner: I,
+        def_id: I::CoroutineClosureId,
+        args: I::GenericArgs,
+    ) -> Self;
 
-    fn new_closure(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
+    fn new_closure(interner: I, def_id: I::ClosureId, args: I::GenericArgs) -> Self;
 
-    fn new_coroutine_witness(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
+    fn new_coroutine_witness(interner: I, def_id: I::CoroutineId, args: I::GenericArgs) -> Self;
 
     fn new_coroutine_witness_for_coroutine(
         interner: I,
-        def_id: I::DefId,
+        def_id: I::CoroutineId,
         coroutine_args: I::GenericArgs,
     ) -> Self;
 
@@ -112,7 +116,7 @@ pub trait Ty<I: Interner<Ty = Self>>:
         It: Iterator<Item = T>,
         T: CollectAndApply<Self, Self>;
 
-    fn new_fn_def(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
+    fn new_fn_def(interner: I, def_id: I::FunctionId, args: I::GenericArgs) -> Self;
 
     fn new_fn_ptr(interner: I, sig: ty::Binder<I, ty::FnSig<I>>) -> Self;
 
@@ -599,7 +603,7 @@ pub trait ParamLike: Copy + Debug + Hash + Eq {
 }
 
 pub trait AdtDef<I: Interner>: Copy + Debug + Hash + Eq {
-    fn def_id(self) -> I::DefId;
+    fn def_id(self) -> I::AdtId;
 
     fn is_struct(self) -> bool;
 
@@ -646,6 +650,16 @@ pub trait DefId<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
     fn as_local(self) -> Option<I::LocalDefId>;
 }
 
+pub trait SpecificDefId<I: Interner>:
+    DefId<I> + Into<I::DefId> + TryFrom<I::DefId, Error: std::fmt::Debug>
+{
+}
+
+impl<I: Interner, T: DefId<I> + Into<I::DefId> + TryFrom<I::DefId, Error: std::fmt::Debug>>
+    SpecificDefId<I> for T
+{
+}
+
 pub trait BoundExistentialPredicates<I: Interner>:
     Copy + Debug + Hash + Eq + Relate<I> + SliceLike<Item = ty::Binder<I, ty::ExistentialPredicate<I>>>
 {
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index 3355c0c2104..3a83b1739ff 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -9,7 +9,7 @@ use rustc_index::bit_set::DenseBitSet;
 use crate::fold::TypeFoldable;
 use crate::inherent::*;
 use crate::ir_print::IrPrint;
-use crate::lang_items::{SolverLangItem, SolverTraitLangItem};
+use crate::lang_items::{SolverAdtLangItem, SolverLangItem, SolverTraitLangItem};
 use crate::relate::Relate;
 use crate::solve::{
     CanonicalInput, ExternalConstraintsData, PredefinedOpaquesData, QueryResult, inspect,
@@ -41,13 +41,20 @@ pub trait Interner:
 
     type DefId: DefId<Self>;
     type LocalDefId: Copy + Debug + Hash + Eq + Into<Self::DefId> + TypeFoldable<Self>;
-    /// A `DefId` of a trait.
-    ///
-    /// In rustc this is just a `DefId`, but rust-analyzer uses different types for different items.
-    ///
-    /// Note: The `TryFrom<DefId>` always succeeds (in rustc), so don't use it to check if some `DefId`
-    /// is a trait!
-    type TraitId: DefId<Self> + Into<Self::DefId> + TryFrom<Self::DefId, Error: std::fmt::Debug>;
+    // Various more specific `DefId`s.
+    //
+    // rustc just defines them all to be `DefId`, but rust-analyzer uses different types so this is convenient for it.
+    //
+    // Note: The `TryFrom<DefId>` always succeeds (in rustc), so don't use it to check if some `DefId`
+    // is of some specific type!
+    type TraitId: SpecificDefId<Self>;
+    type ForeignId: SpecificDefId<Self>;
+    type FunctionId: SpecificDefId<Self>;
+    type ClosureId: SpecificDefId<Self>;
+    type CoroutineClosureId: SpecificDefId<Self>;
+    type CoroutineId: SpecificDefId<Self>;
+    type AdtId: SpecificDefId<Self>;
+    type ImplId: SpecificDefId<Self>;
     type Span: Span<Self>;
 
     type GenericArgs: GenericArgs<Self>;
@@ -199,7 +206,7 @@ pub trait Interner:
     -> ty::EarlyBinder<Self, Self::Ty>;
 
     type AdtDef: AdtDef<Self>;
-    fn adt_def(self, adt_def_id: Self::DefId) -> Self::AdtDef;
+    fn adt_def(self, adt_def_id: Self::AdtId) -> Self::AdtDef;
 
     fn alias_ty_kind(self, alias: ty::AliasTy<Self>) -> ty::AliasTyKind;
 
@@ -240,17 +247,17 @@ pub trait Interner:
 
     fn coroutine_hidden_types(
         self,
-        def_id: Self::DefId,
+        def_id: Self::CoroutineId,
     ) -> ty::EarlyBinder<Self, ty::Binder<Self, ty::CoroutineWitnessTypes<Self>>>;
 
     fn fn_sig(
         self,
-        def_id: Self::DefId,
+        def_id: Self::FunctionId,
     ) -> ty::EarlyBinder<Self, ty::Binder<Self, ty::FnSig<Self>>>;
 
-    fn coroutine_movability(self, def_id: Self::DefId) -> Movability;
+    fn coroutine_movability(self, def_id: Self::CoroutineId) -> Movability;
 
-    fn coroutine_for_closure(self, def_id: Self::DefId) -> Self::DefId;
+    fn coroutine_for_closure(self, def_id: Self::CoroutineClosureId) -> Self::CoroutineId;
 
     fn generics_require_sized_self(self, def_id: Self::DefId) -> bool;
 
@@ -293,11 +300,11 @@ pub trait Interner:
     /// and filtering them to the outlives predicates. This is purely for performance.
     fn impl_super_outlives(
         self,
-        impl_def_id: Self::DefId,
+        impl_def_id: Self::ImplId,
     ) -> ty::EarlyBinder<Self, impl IntoIterator<Item = Self::Clause>>;
 
-    fn impl_is_const(self, def_id: Self::DefId) -> bool;
-    fn fn_is_const(self, def_id: Self::DefId) -> bool;
+    fn impl_is_const(self, def_id: Self::ImplId) -> bool;
+    fn fn_is_const(self, def_id: Self::FunctionId) -> bool;
     fn alias_has_const_conditions(self, def_id: Self::DefId) -> bool;
     fn const_conditions(
         self,
@@ -308,42 +315,49 @@ pub trait Interner:
         def_id: Self::DefId,
     ) -> ty::EarlyBinder<Self, impl IntoIterator<Item = ty::Binder<Self, ty::TraitRef<Self>>>>;
 
-    fn impl_self_is_guaranteed_unsized(self, def_id: Self::DefId) -> bool;
+    fn impl_self_is_guaranteed_unsized(self, def_id: Self::ImplId) -> bool;
 
-    fn has_target_features(self, def_id: Self::DefId) -> bool;
+    fn has_target_features(self, def_id: Self::FunctionId) -> bool;
 
     fn require_lang_item(self, lang_item: SolverLangItem) -> Self::DefId;
 
     fn require_trait_lang_item(self, lang_item: SolverTraitLangItem) -> Self::TraitId;
 
+    fn require_adt_lang_item(self, lang_item: SolverAdtLangItem) -> Self::AdtId;
+
     fn is_lang_item(self, def_id: Self::DefId, lang_item: SolverLangItem) -> bool;
 
     fn is_trait_lang_item(self, def_id: Self::TraitId, lang_item: SolverTraitLangItem) -> bool;
 
+    fn is_adt_lang_item(self, def_id: Self::AdtId, lang_item: SolverAdtLangItem) -> bool;
+
     fn is_default_trait(self, def_id: Self::TraitId) -> bool;
 
     fn as_lang_item(self, def_id: Self::DefId) -> Option<SolverLangItem>;
 
     fn as_trait_lang_item(self, def_id: Self::TraitId) -> Option<SolverTraitLangItem>;
 
+    fn as_adt_lang_item(self, def_id: Self::AdtId) -> Option<SolverAdtLangItem>;
+
     fn associated_type_def_ids(self, def_id: Self::DefId) -> impl IntoIterator<Item = Self::DefId>;
 
     fn for_each_relevant_impl(
         self,
         trait_def_id: Self::TraitId,
         self_ty: Self::Ty,
-        f: impl FnMut(Self::DefId),
+        f: impl FnMut(Self::ImplId),
     );
 
     fn has_item_definition(self, def_id: Self::DefId) -> bool;
 
-    fn impl_specializes(self, impl_def_id: Self::DefId, victim_def_id: Self::DefId) -> bool;
+    fn impl_specializes(self, impl_def_id: Self::ImplId, victim_def_id: Self::ImplId) -> bool;
 
-    fn impl_is_default(self, impl_def_id: Self::DefId) -> bool;
+    fn impl_is_default(self, impl_def_id: Self::ImplId) -> bool;
 
-    fn impl_trait_ref(self, impl_def_id: Self::DefId) -> ty::EarlyBinder<Self, ty::TraitRef<Self>>;
+    fn impl_trait_ref(self, impl_def_id: Self::ImplId)
+    -> ty::EarlyBinder<Self, ty::TraitRef<Self>>;
 
-    fn impl_polarity(self, impl_def_id: Self::DefId) -> ty::ImplPolarity;
+    fn impl_polarity(self, impl_def_id: Self::ImplId) -> ty::ImplPolarity;
 
     fn trait_is_auto(self, trait_def_id: Self::TraitId) -> bool;
 
@@ -364,13 +378,13 @@ pub trait Interner:
 
     fn delay_bug(self, msg: impl ToString) -> Self::ErrorGuaranteed;
 
-    fn is_general_coroutine(self, coroutine_def_id: Self::DefId) -> bool;
-    fn coroutine_is_async(self, coroutine_def_id: Self::DefId) -> bool;
-    fn coroutine_is_gen(self, coroutine_def_id: Self::DefId) -> bool;
-    fn coroutine_is_async_gen(self, coroutine_def_id: Self::DefId) -> bool;
+    fn is_general_coroutine(self, coroutine_def_id: Self::CoroutineId) -> bool;
+    fn coroutine_is_async(self, coroutine_def_id: Self::CoroutineId) -> bool;
+    fn coroutine_is_gen(self, coroutine_def_id: Self::CoroutineId) -> bool;
+    fn coroutine_is_async_gen(self, coroutine_def_id: Self::CoroutineId) -> bool;
 
     type UnsizingParams: Deref<Target = DenseBitSet<u32>>;
-    fn unsizing_params_for_adt(self, adt_def_id: Self::DefId) -> Self::UnsizingParams;
+    fn unsizing_params_for_adt(self, adt_def_id: Self::AdtId) -> Self::UnsizingParams;
 
     fn anonymize_bound_vars<T: TypeFoldable<Self>>(
         self,
diff --git a/compiler/rustc_type_ir/src/lang_items.rs b/compiler/rustc_type_ir/src/lang_items.rs
index 31f8f5be588..5f503d8b912 100644
--- a/compiler/rustc_type_ir/src/lang_items.rs
+++ b/compiler/rustc_type_ir/src/lang_items.rs
@@ -11,6 +11,11 @@ pub enum SolverLangItem {
     DynMetadata,
     FutureOutput,
     Metadata,
+    // tidy-alphabetical-end
+}
+
+pub enum SolverAdtLangItem {
+    // tidy-alphabetical-start
     Option,
     Poll,
     // tidy-alphabetical-end
diff --git a/compiler/rustc_type_ir/src/relate.rs b/compiler/rustc_type_ir/src/relate.rs
index 223230fde9e..690a5f65e08 100644
--- a/compiler/rustc_type_ir/src/relate.rs
+++ b/compiler/rustc_type_ir/src/relate.rs
@@ -405,7 +405,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             Ok(if a_args.is_empty() {
                 a
             } else {
-                let args = relation.relate_item_args(a_def.def_id(), a_args, b_args)?;
+                let args = relation.relate_item_args(a_def.def_id().into(), a_args, b_args)?;
                 if args == a_args { a } else { Ty::new_adt(cx, a_def, args) }
             })
         }
@@ -524,7 +524,7 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
             Ok(if a_args.is_empty() {
                 a
             } else {
-                let args = relation.relate_item_args(a_def_id, a_args, b_args)?;
+                let args = relation.relate_item_args(a_def_id.into(), a_args, b_args)?;
                 if args == a_args { a } else { Ty::new_fn_def(cx, a_def_id, args) }
             })
         }
diff --git a/compiler/rustc_type_ir/src/solve/mod.rs b/compiler/rustc_type_ir/src/solve/mod.rs
index b6d362d77c4..b48a8f46ebe 100644
--- a/compiler/rustc_type_ir/src/solve/mod.rs
+++ b/compiler/rustc_type_ir/src/solve/mod.rs
@@ -136,7 +136,7 @@ pub enum CandidateSource<I: Interner> {
     ///     let y = x.clone();
     /// }
     /// ```
-    Impl(I::DefId),
+    Impl(I::ImplId),
     /// A builtin impl generated by the compiler. When adding a new special
     /// trait, try to use actual impls whenever possible. Builtin impls should
     /// only be used in cases where the impl cannot be manually be written.
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index bde506ffd93..225d85f79c3 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -101,7 +101,7 @@ pub enum TyKind<I: Interner> {
     Adt(I::AdtDef, I::GenericArgs),
 
     /// An unsized FFI type that is opaque to Rust. Written as `extern type T`.
-    Foreign(I::DefId),
+    Foreign(I::ForeignId),
 
     /// The pointee of a string slice. Written as `str`.
     Str,
@@ -137,7 +137,7 @@ pub enum TyKind<I: Interner> {
     /// fn foo() -> i32 { 1 }
     /// let bar = foo; // bar: fn() -> i32 {foo}
     /// ```
-    FnDef(I::DefId, I::GenericArgs),
+    FnDef(I::FunctionId, I::GenericArgs),
 
     /// A pointer to a function. Written as `fn() -> i32`.
     ///
@@ -172,21 +172,21 @@ pub enum TyKind<I: Interner> {
     /// Closure args contain both the - potentially instantiated - generic parameters
     /// of its parent and some synthetic parameters. See the documentation for
     /// `ClosureArgs` for more details.
-    Closure(I::DefId, I::GenericArgs),
+    Closure(I::ClosureId, I::GenericArgs),
 
     /// The anonymous type of a closure. Used to represent the type of `async |a| a`.
     ///
     /// Coroutine-closure args contain both the - potentially instantiated - generic
     /// parameters of its parent and some synthetic parameters. See the documentation
     /// for `CoroutineClosureArgs` for more details.
-    CoroutineClosure(I::DefId, I::GenericArgs),
+    CoroutineClosure(I::CoroutineClosureId, I::GenericArgs),
 
     /// The anonymous type of a coroutine. Used to represent the type of
     /// `|a| yield a`.
     ///
     /// For more info about coroutine args, visit the documentation for
     /// `CoroutineArgs`.
-    Coroutine(I::DefId, I::GenericArgs),
+    Coroutine(I::CoroutineId, I::GenericArgs),
 
     /// A type representing the types stored inside a coroutine.
     /// This should only appear as part of the `CoroutineArgs`.
@@ -211,7 +211,7 @@ pub enum TyKind<I: Interner> {
     /// }
     /// # ;
     /// ```
-    CoroutineWitness(I::DefId, I::GenericArgs),
+    CoroutineWitness(I::CoroutineId, I::GenericArgs),
 
     /// The never type `!`.
     Never,
diff --git a/compiler/rustc_type_ir/src/ty_kind/closure.rs b/compiler/rustc_type_ir/src/ty_kind/closure.rs
index a2e16d917a9..3a6d1acfa8d 100644
--- a/compiler/rustc_type_ir/src/ty_kind/closure.rs
+++ b/compiler/rustc_type_ir/src/ty_kind/closure.rs
@@ -391,7 +391,7 @@ impl<I: Interner> CoroutineClosureSignature<I> {
         cx: I,
         parent_args: I::GenericArgsSlice,
         coroutine_kind_ty: I::Ty,
-        coroutine_def_id: I::DefId,
+        coroutine_def_id: I::CoroutineId,
         tupled_upvars_ty: I::Ty,
     ) -> I::Ty {
         let coroutine_args = ty::CoroutineArgs::new(
@@ -418,7 +418,7 @@ impl<I: Interner> CoroutineClosureSignature<I> {
         self,
         cx: I,
         parent_args: I::GenericArgsSlice,
-        coroutine_def_id: I::DefId,
+        coroutine_def_id: I::CoroutineId,
         goal_kind: ty::ClosureKind,
         env_region: I::Region,
         closure_tupled_upvars_ty: I::Ty,