Remove query impl_item_trait_item_ids, fix typo

compiler/rustc_middle/src/query/mod.rs

@@ -819,32 +819,6 @@ rustc_queries! {
         desc { |tcx| "comparing impl items against trait for `{}`", tcx.def_path_str(impl_id) }
     }
 
-    /// Maps from associated items on the impl specified by `impl_id`
-    /// to the corresponding associated item on the trait.
-    ///
-    /// For example, with the following code
-    ///
-    /// ```
-    /// struct Type {}
-    ///                         // DefId
-    /// trait Trait {           // trait_id
-    ///     fn f();             // trait_f
-    ///     fn g() {}           // trait_g
-    /// }
-    ///
-    /// impl Trait for Type {   // impl_id
-    ///     fn f() {}           // impl_f
-    ///     fn g() {}           // impl_g
-    /// }
-    /// ```
-    ///
-    /// The map returned for `tcx.impl_item_trait_item_ids(impl_id)` would be
-    ///`{ impl_f: trait_f, impl_g: trait_g }`
-    query impl_item_trait_item_ids(impl_id: DefId) -> &'tcx DefIdMap<DefId> {
-        arena_cache
-        desc { |tcx| "comparing impl items against trait for `{}`", tcx.def_path_str(impl_id) }
-    }
-
     /// Given `fn_def_id` of a trait or of an impl that implements a given trait:
     /// if `fn_def_id` is the def id of a function defined inside a trait, then it creates and returns
     /// the associated items that correspond to each impl trait in return position for that trait.

compiler/rustc_passes/src/dead.rs

@@ -3,7 +3,7 @@
 // expectations such as `#[expect(unused)]` and `#[expect(dead_code)]` is live, and everything else
 // is dead.
 
-use hir::def_id::{LocalDefIdMap, LocalDefIdSet};
+use hir::def_id::{DefIdMap, LocalDefIdMap, LocalDefIdSet};
 use hir::ItemKind;
 use rustc_data_structures::unord::UnordSet;
 use rustc_errors::MultiSpan;
@@ -80,6 +80,7 @@ struct MarkSymbolVisitor<'tcx> {
     // and the span of their respective impl (i.e., part of the derive
     // macro)
     ignored_derived_traits: LocalDefIdMap<Vec<(DefId, DefId)>>,
+    impl_item_trait_item_ids_cache: DefIdMap<DefIdMap<DefId>>,
 }
 
 impl<'tcx> MarkSymbolVisitor<'tcx> {
@@ -490,7 +491,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         let mut ready;
         (ready, unsolved_impl_items) =
             unsolved_impl_items.into_iter().partition(|&(impl_id, impl_item_id)| {
-                self.impl_item_with_used_self_and_trait_term(impl_id, impl_item_id)
+                self.impl_item_with_used_self_and_trait_item(impl_id, impl_item_id)
             });
 
         while !ready.is_empty() {
@@ -500,12 +501,12 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
 
             (ready, unsolved_impl_items) =
                 unsolved_impl_items.into_iter().partition(|&(impl_id, impl_item_id)| {
-                    self.impl_item_with_used_self_and_trait_term(impl_id, impl_item_id)
+                    self.impl_item_with_used_self_and_trait_item(impl_id, impl_item_id)
                 });
         }
     }
 
-    fn impl_item_with_used_self_and_trait_term(
+    fn impl_item_with_used_self_and_trait_item(
         &mut self,
         impl_id: hir::ItemId,
         impl_item_id: LocalDefId,
@@ -520,20 +521,32 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 // for the public method, we don't know the trait item is used or not,
                 // so we mark the method live if the self is used
                 return self.live_symbols.contains(&local_def_id);
-            } else if let Some(trait_item_id) = self
-                .tcx
-                .impl_item_trait_item_ids(impl_id.owner_id.to_def_id())
-                .get(&impl_item_id.to_def_id())
+            }
+
+            let impl_id = impl_id.owner_id.to_def_id();
+            let impl_item_trait_item_ids = self
+                .impl_item_trait_item_ids_cache
+                .entry(impl_id)
+                .or_insert_with(|| Self::impl_item_trait_item_ids(self.tcx, impl_id));
+
+            if let Some(trait_item_id) = impl_item_trait_item_ids.get(&impl_item_id.to_def_id())
                 && let Some(local_id) = trait_item_id.as_local()
             {
-                // for the private method, we can know the trait item is ued or not,
+                // for the private method, we can know the trait item is used or not,
                 // so we mark the method live if the self is used and the trait item is used
                 return self.live_symbols.contains(&local_id)
                     && self.live_symbols.contains(&local_def_id);
             }
         }
         false
     }
+
+    fn impl_item_trait_item_ids(tcx: TyCtxt<'tcx>, impl_id: DefId) -> DefIdMap<DefId> {
+        tcx.associated_items(impl_id)
+            .in_definition_order()
+            .filter_map(|item| item.trait_item_def_id.map(|trait_item| (item.def_id, trait_item)))
+            .collect()
+    }
 }
 
 impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
@@ -888,6 +901,7 @@ fn live_symbols_and_ignored_derived_traits(
         ignore_variant_stack: vec![],
         struct_constructors,
         ignored_derived_traits: Default::default(),
+        impl_item_trait_item_ids_cache: Default::default(),
     };
     symbol_visitor.mark_live_symbols();
     symbol_visitor.solve_rest_impl_items(unsolved_impl_items);

compiler/rustc_ty_utils/src/assoc.rs

@@ -15,7 +15,6 @@ pub(crate) fn provide(providers: &mut Providers) {
         associated_types_for_impl_traits_in_associated_fn,
         associated_type_for_impl_trait_in_trait,
         impl_item_implementor_ids,
-        impl_item_trait_item_ids,
         ..*providers
     };
 }
@@ -93,13 +92,6 @@ fn impl_item_implementor_ids(tcx: TyCtxt<'_>, impl_id: DefId) -> DefIdMap<DefId>
         .collect()
 }
 
-fn impl_item_trait_item_ids(tcx: TyCtxt<'_>, impl_id: DefId) -> DefIdMap<DefId> {
-    tcx.associated_items(impl_id)
-        .in_definition_order()
-        .filter_map(|item| item.trait_item_def_id.map(|trait_item| (item.def_id, trait_item)))
-        .collect()
-}
-
 fn associated_item(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AssocItem {
     let id = tcx.local_def_id_to_hir_id(def_id);
     let parent_def_id = tcx.hir().get_parent_item(id);