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.

Author: bors

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 {

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)

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()

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(

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(

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,
             };
 

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.
 

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) {

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);

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 {