Auto merge of #144377 - camsteffen:simplify-impl-of-method, r=fee1-dead

Rename impl_of_method and trait_of_item

This PR used to tweak the implementation of impl_of_method, but that introduced a perf regression.

Rename impl_of_method and trait_of_item to impl_of_assoc and trait_of_assoc respectively. This reflects how the two functions are closely related. And it reflects the behavior more accurately as the functions check whether the input is an associated item.

32 files changed, 56 insertions, 60 deletions

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index bfe806e8901..be8b3f0bc1e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -2384,7 +2384,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         if let Some(body_expr) = finder.body_expr
             && let Some(loop_span) = finder.loop_span
             && let Some(def_id) = typeck_results.type_dependent_def_id(body_expr.hir_id)
-            && let Some(trait_did) = tcx.trait_of_item(def_id)
+            && let Some(trait_did) = tcx.trait_of_assoc(def_id)
             && tcx.is_diagnostic_item(sym::Iterator, trait_did)
         {
             if let Some(loop_bind) = finder.loop_bind {
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index ed4cd52ed9c..56fdaf1c724 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -938,7 +938,7 @@ impl<'tcx> BorrowedContentSource<'tcx> {
     fn from_call(func: Ty<'tcx>, tcx: TyCtxt<'tcx>) -> Option<Self> {
         match *func.kind() {
             ty::FnDef(def_id, args) => {
-                let trait_id = tcx.trait_of_item(def_id)?;
+                let trait_id = tcx.trait_of_assoc(def_id)?;
 
                 if tcx.is_lang_item(trait_id, LangItem::Deref)
                     || tcx.is_lang_item(trait_id, LangItem::DerefMut)
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
index a06540f8325..5d9416b59fc 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -682,7 +682,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         }
         let my_def = self.body.source.def_id();
         let Some(td) =
-            self.infcx.tcx.impl_of_method(my_def).and_then(|x| self.infcx.tcx.trait_id_of_impl(x))
+            self.infcx.tcx.impl_of_assoc(my_def).and_then(|x| self.infcx.tcx.trait_id_of_impl(x))
         else {
             return (false, false, None);
         };
@@ -880,7 +880,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                         let opt_suggestions = tcx
                             .typeck(path_segment.hir_id.owner.def_id)
                             .type_dependent_def_id(expr.hir_id)
-                            .and_then(|def_id| tcx.impl_of_method(def_id))
+                            .and_then(|def_id| tcx.impl_of_assoc(def_id))
                             .map(|def_id| tcx.associated_items(def_id))
                             .map(|assoc_items| {
                                 assoc_items
@@ -1056,7 +1056,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                         .tcx
                         .typeck(path_segment.hir_id.owner.def_id)
                         .type_dependent_def_id(cur_expr.hir_id)
-                        .and_then(|def_id| self.infcx.tcx.impl_of_method(def_id))
+                        .and_then(|def_id| self.infcx.tcx.impl_of_assoc(def_id))
                         .map(|def_id| self.infcx.tcx.associated_items(def_id))
                         .map(|assoc_items| {
                             assoc_items.filter_by_name_unhygienic(sym::iter_mut).peekable()
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index f363ef0a5a9..f5fedbf95c1 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -1761,7 +1761,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 );
 
                 assert!(!matches!(
-                    tcx.impl_of_method(def_id).map(|imp| tcx.def_kind(imp)),
+                    tcx.impl_of_assoc(def_id).map(|imp| tcx.def_kind(imp)),
                     Some(DefKind::Impl { of_trait: true })
                 ));
                 self.prove_predicates(
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 5ca2505cec4..6cbf2dbf7d3 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -533,7 +533,7 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             // First, let's see if this is a method within an inherent impl. Because
             // if yes, we want to make the result subroutine DIE a child of the
             // subroutine's self-type.
-            if let Some(impl_def_id) = cx.tcx.impl_of_method(instance.def_id()) {
+            if let Some(impl_def_id) = cx.tcx.impl_of_assoc(instance.def_id()) {
                 // If the method does *not* belong to a trait, proceed
                 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
                     let impl_self_ty = cx.tcx.instantiate_and_normalize_erasing_regions(
diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 2f5eca2d6b2..297bdec2bc2 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -86,7 +86,7 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
             // Only consider nodes that actually have exported symbols.
             match tcx.def_kind(def_id) {
                 DefKind::Fn | DefKind::Static { .. } => {}
-                DefKind::AssocFn if tcx.impl_of_method(def_id.to_def_id()).is_some() => {}
+                DefKind::AssocFn if tcx.impl_of_assoc(def_id.to_def_id()).is_some() => {}
                 _ => return None,
             };
 
diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs
index 69637cadcc9..44e5d1d5ee7 100644
--- a/compiler/rustc_const_eval/src/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/check_consts/check.rs
@@ -784,7 +784,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                     self.revalidate_conditional_constness(callee, fn_args, *fn_span);
 
                 // Attempting to call a trait method?
-                if let Some(trait_did) = tcx.trait_of_item(callee) {
+                if let Some(trait_did) = tcx.trait_of_assoc(callee) {
                     // We can't determine the actual callee here, so we have to do different checks
                     // than usual.
 
diff --git a/compiler/rustc_const_eval/src/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/check_consts/qualifs.rs
index 166491b47a1..faf41f1658b 100644
--- a/compiler/rustc_const_eval/src/check_consts/qualifs.rs
+++ b/compiler/rustc_const_eval/src/check_consts/qualifs.rs
@@ -369,7 +369,7 @@ where
         assert!(promoted.is_none() || Q::ALLOW_PROMOTED);
 
         // Don't peek inside trait associated constants.
-        if promoted.is_none() && cx.tcx.trait_of_item(def).is_none() {
+        if promoted.is_none() && cx.tcx.trait_of_assoc(def).is_none() {
             let qualifs = cx.tcx.at(constant.span).mir_const_qualif(def);
 
             if !Q::in_qualifs(&qualifs) {
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index bda00ea2fb8..5b3adba0265 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -725,7 +725,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     ) {
         let tcx = *self.tcx;
 
-        let trait_def_id = tcx.trait_of_item(def_id).unwrap();
+        let trait_def_id = tcx.trait_of_assoc(def_id).unwrap();
         let virtual_trait_ref = ty::TraitRef::from_method(tcx, trait_def_id, virtual_instance.args);
         let existential_trait_ref = ty::ExistentialTraitRef::erase_self_ty(tcx, virtual_trait_ref);
         let concrete_trait_ref = existential_trait_ref.with_self_ty(tcx, dyn_ty);
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index ca57c4f3164..3fee9af01b3 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -295,6 +295,10 @@ impl DefKind {
         }
     }
 
+    pub fn is_assoc(self) -> bool {
+        matches!(self, DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy)
+    }
+
     /// This is a "module" in name resolution sense.
     #[inline]
     pub fn is_module_like(self) -> bool {
diff --git a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
index 2d60c9561a9..835f8e8cdae 100644
--- a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
+++ b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
@@ -759,7 +759,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         &self,
         err: &mut Diag<'_, impl EmissionGuarantee>,
     ) {
-        let trait_ = match self.tcx.trait_of_item(self.def_id) {
+        let trait_ = match self.tcx.trait_of_assoc(self.def_id) {
             Some(def_id) => def_id,
             None => return,
         };
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
index 287a5532f01..f73442fdebd 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
@@ -755,7 +755,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let limit = if candidates.len() == 5 { 5 } else { 4 };
 
         for (index, &item) in candidates.iter().take(limit).enumerate() {
-            let impl_ = tcx.impl_of_method(item).unwrap();
+            let impl_ = tcx.impl_of_assoc(item).unwrap();
 
             let note_span = if item.is_local() {
                 Some(tcx.def_span(item))
diff --git a/compiler/rustc_hir_typeck/src/fallback.rs b/compiler/rustc_hir_typeck/src/fallback.rs
index 759b5d9550c..9406697dfed 100644
--- a/compiler/rustc_hir_typeck/src/fallback.rs
+++ b/compiler/rustc_hir_typeck/src/fallback.rs
@@ -694,7 +694,7 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
         // i.e. changing `Default::default()` to `<() as Default>::default()`.
         if let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = expr.kind
             && let Res::Def(DefKind::AssocFn, def_id) = path.res
-            && self.fcx.tcx.trait_of_item(def_id).is_some()
+            && self.fcx.tcx.trait_of_assoc(def_id).is_some()
             && let Some(args) = self.fcx.typeck_results.borrow().node_args_opt(expr.hir_id)
             && let self_ty = args.type_at(0)
             && let Some(vid) = self.fcx.root_vid(self_ty)
diff --git a/compiler/rustc_lint/src/map_unit_fn.rs b/compiler/rustc_lint/src/map_unit_fn.rs
index a8803158889..34210137bde 100644
--- a/compiler/rustc_lint/src/map_unit_fn.rs
+++ b/compiler/rustc_lint/src/map_unit_fn.rs
@@ -96,7 +96,7 @@ impl<'tcx> LateLintPass<'tcx> for MapUnitFn {
 
 fn is_impl_slice(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
-        && let Some(impl_id) = cx.tcx.impl_of_method(method_id)
+        && let Some(impl_id) = cx.tcx.impl_of_assoc(method_id)
     {
         return cx.tcx.type_of(impl_id).skip_binder().is_slice();
     }
diff --git a/compiler/rustc_lint/src/noop_method_call.rs b/compiler/rustc_lint/src/noop_method_call.rs
index b7835e6c36a..24682c4562a 100644
--- a/compiler/rustc_lint/src/noop_method_call.rs
+++ b/compiler/rustc_lint/src/noop_method_call.rs
@@ -84,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
             return;
         };
 
-        let Some(trait_id) = cx.tcx.trait_of_item(did) else { return };
+        let Some(trait_id) = cx.tcx.trait_of_assoc(did) else { return };
 
         let Some(trait_) = cx.tcx.get_diagnostic_name(trait_id) else { return };
 
diff --git a/compiler/rustc_lint/src/pass_by_value.rs b/compiler/rustc_lint/src/pass_by_value.rs
index d3b3b55dd4c..a3cf3d568b1 100644
--- a/compiler/rustc_lint/src/pass_by_value.rs
+++ b/compiler/rustc_lint/src/pass_by_value.rs
@@ -24,7 +24,7 @@ impl<'tcx> LateLintPass<'tcx> for PassByValue {
     fn check_ty(&mut self, cx: &LateContext<'_>, ty: &'tcx hir::Ty<'tcx, AmbigArg>) {
         match &ty.kind {
             TyKind::Ref(_, hir::MutTy { ty: inner_ty, mutbl: hir::Mutability::Not }) => {
-                if let Some(impl_did) = cx.tcx.impl_of_method(ty.hir_id.owner.to_def_id()) {
+                if let Some(impl_did) = cx.tcx.impl_of_assoc(ty.hir_id.owner.to_def_id()) {
                     if cx.tcx.impl_trait_ref(impl_did).is_some() {
                         return;
                     }
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index fc9d795cb23..b0afc333ebe 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -1904,7 +1904,7 @@ impl InvalidAtomicOrdering {
         if let ExprKind::MethodCall(method_path, _, args, _) = &expr.kind
             && recognized_names.contains(&method_path.ident.name)
             && let Some(m_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
-            && let Some(impl_did) = cx.tcx.impl_of_method(m_def_id)
+            && let Some(impl_did) = cx.tcx.impl_of_assoc(m_def_id)
             && let Some(adt) = cx.tcx.type_of(impl_did).instantiate_identity().ty_adt_def()
             // skip extension traits, only lint functions from the standard library
             && cx.tcx.trait_id_of_impl(impl_did).is_none()
diff --git a/compiler/rustc_middle/src/middle/privacy.rs b/compiler/rustc_middle/src/middle/privacy.rs
index 03549091d62..785ddd1ee29 100644
--- a/compiler/rustc_middle/src/middle/privacy.rs
+++ b/compiler/rustc_middle/src/middle/privacy.rs
@@ -182,7 +182,7 @@ impl EffectiveVisibilities {
             // don't check this condition for them.
             let is_impl = matches!(tcx.def_kind(def_id), DefKind::Impl { .. });
             let is_associated_item_in_trait_impl = tcx
-                .impl_of_method(def_id.to_def_id())
+                .impl_of_assoc(def_id.to_def_id())
                 .and_then(|impl_id| tcx.trait_id_of_impl(impl_id))
                 .is_some();
             if !is_impl && !is_associated_item_in_trait_impl {
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 4c95f0748d3..bb70c61cd14 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1988,29 +1988,21 @@ impl<'tcx> TyCtxt<'tcx> {
         self.impl_trait_ref(def_id).map(|tr| tr.skip_binder().def_id)
     }
 
-    /// If the given `DefId` describes an item belonging to a trait,
-    /// returns the `DefId` of the trait that the trait item belongs to;
-    /// otherwise, returns `None`.
-    pub fn trait_of_item(self, def_id: DefId) -> Option<DefId> {
-        if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) {
-            let parent = self.parent(def_id);
-            if let DefKind::Trait | DefKind::TraitAlias = self.def_kind(parent) {
-                return Some(parent);
-            }
-        }
-        None
+    /// If the given `DefId` is an associated item, returns the `DefId` of the parent trait or impl.
+    pub fn assoc_parent(self, def_id: DefId) -> Option<DefId> {
+        self.def_kind(def_id).is_assoc().then(|| self.parent(def_id))
     }
 
-    /// If the given `DefId` describes a method belonging to an impl, returns the
-    /// `DefId` of the impl that the method belongs to; otherwise, returns `None`.
-    pub fn impl_of_method(self, def_id: DefId) -> Option<DefId> {
-        if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) {
-            let parent = self.parent(def_id);
-            if let DefKind::Impl { .. } = self.def_kind(parent) {
-                return Some(parent);
-            }
-        }
-        None
+    /// If the given `DefId` is an associated item of a trait,
+    /// returns the `DefId` of the trait; otherwise, returns `None`.
+    pub fn trait_of_assoc(self, def_id: DefId) -> Option<DefId> {
+        self.assoc_parent(def_id).filter(|id| self.def_kind(id) == DefKind::Trait)
+    }
+
+    /// If the given `DefId` is an associated item of an impl,
+    /// returns the `DefId` of the impl; otherwise returns `None`.
+    pub fn impl_of_assoc(self, def_id: DefId) -> Option<DefId> {
+        self.assoc_parent(def_id).filter(|id| matches!(self.def_kind(id), DefKind::Impl { .. }))
     }
 
     pub fn is_exportable(self, def_id: DefId) -> bool {
@@ -2181,7 +2173,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     #[inline]
     pub fn is_const_default_method(self, def_id: DefId) -> bool {
-        matches!(self.trait_of_item(def_id), Some(trait_id) if self.is_const_trait(trait_id))
+        matches!(self.trait_of_assoc(def_id), Some(trait_id) if self.is_const_trait(trait_id))
     }
 
     pub fn impl_method_has_trait_impl_trait_tys(self, def_id: DefId) -> bool {
diff --git a/compiler/rustc_mir_transform/src/check_call_recursion.rs b/compiler/rustc_mir_transform/src/check_call_recursion.rs
index cace4cd6bba..6d61ac2dd80 100644
--- a/compiler/rustc_mir_transform/src/check_call_recursion.rs
+++ b/compiler/rustc_mir_transform/src/check_call_recursion.rs
@@ -21,7 +21,7 @@ impl<'tcx> MirLint<'tcx> for CheckCallRecursion {
 
         if let DefKind::Fn | DefKind::AssocFn = tcx.def_kind(def_id) {
             // If this is trait/impl method, extract the trait's args.
-            let trait_args = match tcx.trait_of_item(def_id.to_def_id()) {
+            let trait_args = match tcx.trait_of_assoc(def_id.to_def_id()) {
                 Some(trait_def_id) => {
                     let trait_args_count = tcx.generics_of(trait_def_id).count();
                     &GenericArgs::identity_for_item(tcx, def_id)[..trait_args_count]
@@ -44,7 +44,7 @@ impl<'tcx> MirLint<'tcx> for CheckDropRecursion {
         // First check if `body` is an `fn drop()` of `Drop`
         if let DefKind::AssocFn = tcx.def_kind(def_id)
         && let Some(trait_ref) =
-            tcx.impl_of_method(def_id.to_def_id()).and_then(|def_id| tcx.impl_trait_ref(def_id))
+            tcx.impl_of_assoc(def_id.to_def_id()).and_then(|def_id| tcx.impl_trait_ref(def_id))
         && tcx.is_lang_item(trait_ref.instantiate_identity().def_id, LangItem::Drop)
         // avoid erroneous `Drop` impls from causing ICEs below
         && let sig = tcx.fn_sig(def_id).instantiate_identity()
diff --git a/compiler/rustc_mir_transform/src/check_packed_ref.rs b/compiler/rustc_mir_transform/src/check_packed_ref.rs
index e9b85ba6e9d..dcb812c7899 100644
--- a/compiler/rustc_mir_transform/src/check_packed_ref.rs
+++ b/compiler/rustc_mir_transform/src/check_packed_ref.rs
@@ -40,7 +40,7 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
         if context.is_borrow() && util::is_disaligned(self.tcx, self.body, self.typing_env, *place)
         {
             let def_id = self.body.source.instance.def_id();
-            if let Some(impl_def_id) = self.tcx.impl_of_method(def_id)
+            if let Some(impl_def_id) = self.tcx.impl_of_assoc(def_id)
                 && self.tcx.is_builtin_derived(impl_def_id)
             {
                 // If we ever reach here it means that the generated derive
diff --git a/compiler/rustc_mir_transform/src/coverage/query.rs b/compiler/rustc_mir_transform/src/coverage/query.rs
index 986c001de5e..551f720c869 100644
--- a/compiler/rustc_mir_transform/src/coverage/query.rs
+++ b/compiler/rustc_mir_transform/src/coverage/query.rs
@@ -35,7 +35,7 @@ fn is_eligible_for_coverage(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
     // Don't instrument functions with `#[automatically_derived]` on their
     // enclosing impl block, on the assumption that most users won't care about
     // coverage for derived impls.
-    if let Some(impl_of) = tcx.impl_of_method(def_id.to_def_id())
+    if let Some(impl_of) = tcx.impl_of_assoc(def_id.to_def_id())
         && tcx.is_automatically_derived(impl_of)
     {
         trace!("InstrumentCoverage skipped for {def_id:?} (automatically derived)");
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index 6c65b072bec..c687036f544 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -75,7 +75,7 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceKind<'tcx>) -> Body<
             build_call_shim(tcx, instance, Some(adjustment), CallKind::Direct(def_id))
         }
         ty::InstanceKind::FnPtrShim(def_id, ty) => {
-            let trait_ = tcx.trait_of_item(def_id).unwrap();
+            let trait_ = tcx.trait_of_assoc(def_id).unwrap();
             // Supports `Fn` or `async Fn` traits.
             let adjustment = match tcx
                 .fn_trait_kind_from_def_id(trait_)
diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index f3e7d582781..cee15e0f696 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -650,13 +650,13 @@ fn characteristic_def_id_of_mono_item<'tcx>(
             // its self-type. If the self-type does not provide a characteristic
             // DefId, we use the location of the impl after all.
 
-            if tcx.trait_of_item(def_id).is_some() {
+            if tcx.trait_of_assoc(def_id).is_some() {
                 let self_ty = instance.args.type_at(0);
                 // This is a default implementation of a trait method.
                 return characteristic_def_id_of_type(self_ty).or(Some(def_id));
             }
 
-            if let Some(impl_def_id) = tcx.impl_of_method(def_id) {
+            if let Some(impl_def_id) = tcx.impl_of_assoc(def_id) {
                 if tcx.sess.opts.incremental.is_some()
                     && tcx
                         .trait_id_of_impl(impl_def_id)
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index d987041fe0e..a90d1af87ca 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -368,7 +368,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
     /// will be ignored for the purposes of dead code analysis (see PR #85200
     /// for discussion).
     fn should_ignore_item(&mut self, def_id: DefId) -> bool {
-        if let Some(impl_of) = self.tcx.impl_of_method(def_id) {
+        if let Some(impl_of) = self.tcx.impl_of_assoc(def_id) {
             if !self.tcx.is_automatically_derived(impl_of) {
                 return false;
             }
@@ -429,7 +429,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
             Node::TraitItem(trait_item) => {
                 // mark the trait live
                 let trait_item_id = trait_item.owner_id.to_def_id();
-                if let Some(trait_id) = self.tcx.trait_of_item(trait_item_id) {
+                if let Some(trait_id) = self.tcx.trait_of_assoc(trait_item_id) {
                     self.check_def_id(trait_id);
                 }
                 intravisit::walk_trait_item(self, trait_item);
diff --git a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/transform.rs b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/transform.rs
index c69991f3fb2..52717d73b8a 100644
--- a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/transform.rs
+++ b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/transform.rs
@@ -339,7 +339,7 @@ pub(crate) fn transform_instance<'tcx>(
     } else if let ty::InstanceKind::Virtual(def_id, _) = instance.def {
         // Transform self into a trait object of the trait that defines the method for virtual
         // functions to match the type erasure done below.
-        let upcast_ty = match tcx.trait_of_item(def_id) {
+        let upcast_ty = match tcx.trait_of_assoc(def_id) {
             Some(trait_id) => trait_object_ty(
                 tcx,
                 ty::Binder::dummy(ty::TraitRef::from_method(tcx, trait_id, instance.args)),
@@ -364,7 +364,7 @@ pub(crate) fn transform_instance<'tcx>(
         };
         instance.args = tcx.mk_args_trait(self_ty, instance.args.into_iter().skip(1));
     } else if let ty::InstanceKind::VTableShim(def_id) = instance.def
-        && let Some(trait_id) = tcx.trait_of_item(def_id)
+        && let Some(trait_id) = tcx.trait_of_assoc(def_id)
     {
         // Adjust the type ids of VTableShims to the type id expected in the call sites for the
         // entry in the vtable (i.e., by using the signature of the closure passed as an argument
@@ -466,7 +466,7 @@ fn implemented_method<'tcx>(
     let method_id;
     let trait_id;
     let trait_method;
-    let ancestor = if let Some(impl_id) = tcx.impl_of_method(instance.def_id()) {
+    let ancestor = if let Some(impl_id) = tcx.impl_of_assoc(instance.def_id()) {
         // Implementation in an `impl` block
         trait_ref = tcx.impl_trait_ref(impl_id)?;
         let impl_method = tcx.associated_item(instance.def_id());
@@ -480,7 +480,7 @@ fn implemented_method<'tcx>(
         // Provided method in a `trait` block
         trait_method = trait_method_bound;
         method_id = instance.def_id();
-        trait_id = tcx.trait_of_item(method_id)?;
+        trait_id = tcx.trait_of_assoc(method_id)?;
         trait_ref = ty::EarlyBinder::bind(TraitRef::from_method(tcx, trait_id, instance.args));
         trait_id
     } else {
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
index 1db05ced8d2..022d549a9df 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
@@ -1303,7 +1303,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> {
             && let Some(args) = self.node_args_opt(expr.hir_id)
             && args.iter().any(|arg| self.generic_arg_contains_target(arg))
             && let Some(def_id) = self.typeck_results.type_dependent_def_id(expr.hir_id)
-            && self.tecx.tcx.trait_of_item(def_id).is_some()
+            && self.tecx.tcx.trait_of_assoc(def_id).is_some()
             && !has_impl_trait(def_id)
             // FIXME(fn_delegation): In delegation item argument spans are equal to last path
             // segment. This leads to ICE's when emitting `multipart_suggestion`.
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
index 98f67257fd1..cdf1402252a 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
@@ -360,7 +360,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                             },
                         ] = path.segments
                         && data.trait_ref.def_id == *trait_id
-                        && self.tcx.trait_of_item(*item_id) == Some(*trait_id)
+                        && self.tcx.trait_of_assoc(*item_id) == Some(*trait_id)
                         && let None = self.tainted_by_errors()
                     {
                         let assoc_item = self.tcx.associated_item(item_id);
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index c5248736366..c182fd99b17 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -987,7 +987,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     else {
                         return false;
                     };
-                    if self.tcx.trait_of_item(did) != Some(clone_trait) {
+                    if self.tcx.trait_of_assoc(did) != Some(clone_trait) {
                         return false;
                     }
                     Some(ident.span)
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 91c41544f78..9b5e59ce0fd 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -759,7 +759,7 @@ fn instantiate_and_check_impossible_predicates<'tcx>(
 
     // Specifically check trait fulfillment to avoid an error when trying to resolve
     // associated items.
-    if let Some(trait_def_id) = tcx.trait_of_item(key.0) {
+    if let Some(trait_def_id) = tcx.trait_of_assoc(key.0) {
         let trait_ref = ty::TraitRef::from_method(tcx, trait_def_id, key.1);
         predicates.push(trait_ref.upcast(tcx));
     }
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 28b5b7cf391..581191b2036 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1507,7 +1507,7 @@ fn confirm_builtin_candidate<'cx, 'tcx>(
     let tcx = selcx.tcx();
     let self_ty = obligation.predicate.self_ty();
     let item_def_id = obligation.predicate.def_id;
-    let trait_def_id = tcx.trait_of_item(item_def_id).unwrap();
+    let trait_def_id = tcx.trait_of_assoc(item_def_id).unwrap();
     let args = tcx.mk_args(&[self_ty.into()]);
     let (term, obligations) = if tcx.is_lang_item(trait_def_id, LangItem::DiscriminantKind) {
         let discriminant_def_id =
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index 166e8f19342..e6c3568620b 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -21,7 +21,7 @@ fn resolve_instance_raw<'tcx>(
 ) -> Result<Option<Instance<'tcx>>, ErrorGuaranteed> {
     let PseudoCanonicalInput { typing_env, value: (def_id, args) } = key;
 
-    let result = if let Some(trait_def_id) = tcx.trait_of_item(def_id) {
+    let result = if let Some(trait_def_id) = tcx.trait_of_assoc(def_id) {
         debug!(" => associated item, attempting to find impl in typing_env {:#?}", typing_env);
         resolve_associated_item(
             tcx,