Auto merge of #146328 - zetanumbers:fix-141951, r=lcnr

Skip typeck for items w/o their own typeck context

Skip items which forward typeck to their ancestor.

Should remove some potential but unnecessary typeck query waits, hence might improve performance for the parallel frontend.

Thanks to `@ywxt` for a fix suggestion

Fixes #141951

Author: bors

compiler/rustc_hir/src/def.rs

@@ -440,6 +440,43 @@ impl DefKind {
             | DefKind::ExternCrate => false,
         }
     }
+
+    /// Returns `true` if `self` is a kind of definition that does not have its own
+    /// type-checking context, i.e. closure, coroutine or inline const.
+    #[inline]
+    pub fn is_typeck_child(self) -> bool {
+        match self {
+            DefKind::Closure | DefKind::InlineConst | DefKind::SyntheticCoroutineBody => true,
+            DefKind::Mod
+            | DefKind::Struct
+            | DefKind::Union
+            | DefKind::Enum
+            | DefKind::Variant
+            | DefKind::Trait
+            | DefKind::TyAlias
+            | DefKind::ForeignTy
+            | DefKind::TraitAlias
+            | DefKind::AssocTy
+            | DefKind::TyParam
+            | DefKind::Fn
+            | DefKind::Const
+            | DefKind::ConstParam
+            | DefKind::Static { .. }
+            | DefKind::Ctor(_, _)
+            | DefKind::AssocFn
+            | DefKind::AssocConst
+            | DefKind::Macro(_)
+            | DefKind::ExternCrate
+            | DefKind::Use
+            | DefKind::ForeignMod
+            | DefKind::AnonConst
+            | DefKind::OpaqueTy
+            | DefKind::Field
+            | DefKind::LifetimeParam
+            | DefKind::GlobalAsm
+            | DefKind::Impl { .. } => false,
+        }
+    }
 }
 
 /// The resolution of a path or export.

compiler/rustc_hir_analysis/src/lib.rs

@@ -238,7 +238,8 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
             _ => (),
         }
         // Skip `AnonConst`s because we feed their `type_of`.
-        if !matches!(def_kind, DefKind::AnonConst) {
+        // Also skip items for which typeck forwards to parent typeck.
+        if !(matches!(def_kind, DefKind::AnonConst) || def_kind.is_typeck_child()) {
             tcx.ensure_ok().typeck(item_def_id);
         }
         // Ensure we generate the new `DefId` before finishing `check_crate`.

compiler/rustc_middle/src/ty/util.rs

@@ -608,10 +608,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Returns `true` if `def_id` refers to a definition that does not have its own
     /// type-checking context, i.e. closure, coroutine or inline const.
     pub fn is_typeck_child(self, def_id: DefId) -> bool {
-        matches!(
-            self.def_kind(def_id),
-            DefKind::Closure | DefKind::InlineConst | DefKind::SyntheticCoroutineBody
-        )
+        self.def_kind(def_id).is_typeck_child()
     }
 
     /// Returns `true` if `def_id` refers to a trait (i.e., `trait Foo { ... }`).