Clean up implementation of RPITIT assoc item lowering

Author: compiler-errors

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -15,7 +15,6 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{
     self, BottomUpFolder, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeFoldable, TypeFolder,
     TypeSuperFoldable, TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode, Upcast,
-    associated_types_for_impl_traits_in_associated_fn,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_span::{DUMMY_SP, Span};
@@ -758,7 +757,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     // returning `-> Missing<impl Sized>`, that gets converted to `-> {type error}`,
     // and when walking through the signature we end up never collecting the def id
     // of the `impl Sized`. Insert that here, so we don't ICE later.
-    for assoc_item in associated_types_for_impl_traits_in_associated_fn(tcx, trait_m.def_id) {
+    for assoc_item in tcx.associated_types_for_impl_traits_in_associated_fn(trait_m.def_id) {
         if !remapped_types.contains_key(assoc_item) {
             remapped_types.insert(
                 *assoc_item,
@@ -2449,7 +2448,8 @@ fn param_env_with_gat_bounds<'tcx>(
                     ty::ImplTraitInTraitData::Impl { fn_def_id }
                     | ty::ImplTraitInTraitData::Trait { fn_def_id, .. },
                 ),
-        } => associated_types_for_impl_traits_in_associated_fn(tcx, fn_def_id)
+        } => tcx
+            .associated_types_for_impl_traits_in_associated_fn(fn_def_id)
             .iter()
             .map(|def_id| tcx.associated_item(*def_id))
             .collect(),

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -20,7 +20,7 @@ use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
     self, AdtKind, GenericArgKind, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeFlags,
     TypeFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode,
-    Upcast, associated_types_for_impl_traits_in_associated_fn,
+    Upcast,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_session::parse::feature_err;
@@ -327,7 +327,7 @@ pub(crate) fn check_trait_item<'tcx>(
 
     if matches!(tcx.def_kind(def_id), DefKind::AssocFn) {
         for &assoc_ty_def_id in
-            associated_types_for_impl_traits_in_associated_fn(tcx, def_id.to_def_id())
+            tcx.associated_types_for_impl_traits_in_associated_fn(def_id.to_def_id())
         {
             res = res.and(check_associated_item(tcx, assoc_ty_def_id.expect_local()));
         }

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -40,7 +40,7 @@ use rustc_middle::mir::interpret::LitToConstInput;
 use rustc_middle::ty::print::PrintPolyTraitRefExt as _;
 use rustc_middle::ty::{
     self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, Ty, TyCtxt, TypeVisitableExt,
-    TypingMode, Upcast, associated_types_for_impl_traits_in_associated_fn, fold_regions,
+    TypingMode, Upcast, fold_regions,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint::builtin::AMBIGUOUS_ASSOCIATED_ITEMS;
@@ -2602,7 +2602,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // do a linear search to map this to the synthetic associated type that
         // it will be lowered to.
         let def_id = if let Some(parent_def_id) = in_trait {
-            *associated_types_for_impl_traits_in_associated_fn(tcx, parent_def_id.to_def_id())
+            *tcx.associated_types_for_impl_traits_in_associated_fn(parent_def_id.to_def_id())
                 .iter()
                 .find(|rpitit| match tcx.opt_rpitit_info(**rpitit) {
                     Some(ty::ImplTraitInTraitData::Trait { opaque_def_id, .. }) => {

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -481,7 +481,7 @@ define_tables! {
     assumed_wf_types_for_rpitit: Table<DefIndex, LazyArray<(Ty<'static>, Span)>>,
     opaque_ty_origin: Table<DefIndex, LazyValue<hir::OpaqueTyOrigin<DefId>>>,
     anon_const_kind: Table<DefIndex, LazyValue<ty::AnonConstKind>>,
-    associated_types_for_impl_traits_in_trait_or_impl: Table<DefIndex, LazyValue<ty::AssocTyForImplTraitInTraitOrImpl>>,
+    associated_types_for_impl_traits_in_trait_or_impl: Table<DefIndex, LazyValue<DefIdMap<Vec<DefId>>>>,
 }
 
 #[derive(TyEncodable, TyDecodable)]

compiler/rustc_middle/src/query/mod.rs

@@ -1079,9 +1079,11 @@ rustc_queries! {
         desc { |tcx| "comparing impl items against trait for `{}`", tcx.def_path_str(impl_id) }
     }
 
-    query associated_types_for_impl_traits_in_trait_or_impl(did: DefId) -> &'tcx ty::AssocTyForImplTraitInTraitOrImpl {
+    /// Given the `item_def_id` of a trait or impl, return a mapping from associated fn def id
+    /// to its associated type items that correspond to the RPITITs in its signature.
+    query associated_types_for_impl_traits_in_trait_or_impl(item_def_id: DefId) -> &'tcx DefIdMap<Vec<DefId>> {
         arena_cache
-        desc { |tcx| "creating rpitit for `{}`", tcx.def_path_str(did) }
+        desc { |tcx| "synthesizing RPITIT items for the opaque types for methods in `{}`", tcx.def_path_str(item_def_id) }
         separate_provide_extern
     }
 

compiler/rustc_middle/src/ty/assoc.rs

@@ -1,5 +1,4 @@
 use rustc_attr_data_structures::{AttributeKind, find_attr};
-use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sorted_map::SortedIndexMultiMap;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Namespace};
@@ -287,22 +286,21 @@ impl AssocItems {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Encodable, Decodable, HashStable)]
-pub struct AssocTyForImplTraitInTraitOrImpl(pub FxIndexMap<DefId, Vec<DefId>>);
-
-/// Given an `fn_def_id` of a trait or a trait implementation:
-///
-/// if `fn_def_id` is a function defined inside a trait, then it synthesizes
-/// a new def id corresponding to a new associated type for each return-
-/// position `impl Trait` in the signature.
-///
-/// if `fn_def_id` is a function inside of an impl, then for each synthetic
-/// associated type generated for the corresponding trait function described
-/// above, synthesize a corresponding associated type in the impl.
-pub fn associated_types_for_impl_traits_in_associated_fn(
-    tcx: TyCtxt<'_>,
-    fn_def_id: DefId,
-) -> &'_ [DefId] {
-    let parent_def_id = tcx.parent(fn_def_id);
-    &tcx.associated_types_for_impl_traits_in_trait_or_impl(parent_def_id).0[&fn_def_id]
+impl<'tcx> TyCtxt<'tcx> {
+    /// Given an `fn_def_id` of a trait or a trait implementation:
+    ///
+    /// if `fn_def_id` is a function defined inside a trait, then it synthesizes
+    /// a new def id corresponding to a new associated type for each return-
+    /// position `impl Trait` in the signature.
+    ///
+    /// if `fn_def_id` is a function inside of an impl, then for each synthetic
+    /// associated type generated for the corresponding trait function described
+    /// above, synthesize a corresponding associated type in the impl.
+    pub fn associated_types_for_impl_traits_in_associated_fn(
+        self,
+        fn_def_id: DefId,
+    ) -> &'tcx [DefId] {
+        let parent_def_id = self.parent(fn_def_id);
+        &self.associated_types_for_impl_traits_in_trait_or_impl(parent_def_id)[&fn_def_id]
+    }
 }

compiler/rustc_middle/src/ty/mod.rs

@@ -2194,7 +2194,8 @@ impl<'tcx> TyCtxt<'tcx> {
             return false;
         };
 
-        return !associated_types_for_impl_traits_in_associated_fn(self, trait_item_def_id)
+        return !self
+            .associated_types_for_impl_traits_in_associated_fn(trait_item_def_id)
             .is_empty();
     }
 }

compiler/rustc_middle/src/ty/parameterized.rs

@@ -23,6 +23,10 @@ impl<A: ParameterizedOverTcx, B: ParameterizedOverTcx> ParameterizedOverTcx for
     type Value<'tcx> = (A::Value<'tcx>, B::Value<'tcx>);
 }
 
+impl<T: ParameterizedOverTcx> ParameterizedOverTcx for Vec<T> {
+    type Value<'tcx> = Vec<T::Value<'tcx>>;
+}
+
 impl<I: Idx + 'static, T: ParameterizedOverTcx> ParameterizedOverTcx for IndexVec<I, T> {
     type Value<'tcx> = IndexVec<I, T::Value<'tcx>>;
 }
@@ -67,7 +71,6 @@ trivially_parameterized_over_tcx! {
     crate::mir::ConstQualifs,
     ty::AsyncDestructor,
     ty::AssocItemContainer,
-    ty::AssocTyForImplTraitInTraitOrImpl,
     ty::Asyncness,
     ty::AnonConstKind,
     ty::DeducedParamAttrs,