Add more checks for unnamed_field during HIR analysis

compiler/rustc_hir_analysis/src/check/check.rs

@@ -129,17 +129,20 @@ fn check_unnamed_fields(tcx: TyCtxt<'_>, def: ty::AdtDef<'_>) {
     for field in variant.fields.iter().filter(|f| f.is_unnamed()) {
         let field_ty = tcx.type_of(field.did).instantiate_identity();
         if let Some(adt) = field_ty.ty_adt_def()
-            && !adt.is_anonymous()
-            && !adt.repr().c()
+            && !adt.is_enum()
         {
-            let field_ty_span = tcx.def_span(adt.did());
-            tcx.dcx().emit_err(errors::UnnamedFieldsRepr::FieldMissingReprC {
-                span: tcx.def_span(field.did),
-                field_ty_span,
-                field_ty,
-                field_adt_kind: adt.descr(),
-                sugg_span: field_ty_span.shrink_to_lo(),
-            });
+            if !adt.is_anonymous() && !adt.repr().c() {
+                let field_ty_span = tcx.def_span(adt.did());
+                tcx.dcx().emit_err(errors::UnnamedFieldsRepr::FieldMissingReprC {
+                    span: tcx.def_span(field.did),
+                    field_ty_span,
+                    field_ty,
+                    field_adt_kind: adt.descr(),
+                    sugg_span: field_ty_span.shrink_to_lo(),
+                });
+            }
+        } else {
+            tcx.dcx().emit_err(errors::InvalidUnnamedFieldTy { span: tcx.def_span(field.did) });
         }
     }
 }

compiler/rustc_hir_analysis/src/collect.rs

@@ -943,7 +943,15 @@ impl<'tcx> FieldUniquenessCheckContext<'tcx> {
                 }
             }
             hir::TyKind::Path(hir::QPath::Resolved(_, hir::Path { res, .. })) => {
-                self.check_field_in_nested_adt(self.tcx.adt_def(res.def_id()), field.span);
+                // If this is a direct path to an ADT, we can check it
+                // If this is a type alias or non-ADT, `check_unnamed_fields` should verify it
+                if let Some(def_id) = res.opt_def_id()
+                    && let Some(local) = def_id.as_local()
+                    && let Node::Item(item) = self.tcx.hir_node_by_def_id(local)
+                    && item.is_adt()
+                {
+                    self.check_field_in_nested_adt(self.tcx.adt_def(def_id), field.span);
+                }
             }
             // Abort due to errors (there must be an error if an unnamed field
             //  has any type kind other than an anonymous adt or a named adt)

compiler/rustc_hir_analysis/src/errors.rs

@@ -661,6 +661,13 @@ pub(crate) struct InvalidUnionField {
     pub note: (),
 }
 
+#[derive(Diagnostic)]
+#[diag(hir_analysis_invalid_unnamed_field_ty)]
+pub struct InvalidUnnamedFieldTy {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(hir_analysis_return_type_notation_on_non_rpitit)]
 pub(crate) struct ReturnTypeNotationOnNonRpitit<'tcx> {