[clang] [Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (PR #84050)

[Erich Keane via cfe-commits]

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@@ -126,12 +126,15 @@ struct BuiltinTypeDeclBuilder {
 
   static DeclRefExpr *lookupBuiltinFunction(ASTContext &AST, Sema &S,
                                             StringRef Name) {
-    CXXScopeSpec SS;
     IdentifierInfo &II = AST.Idents.get(Name, tok::TokenKind::identifier);
     DeclarationNameInfo NameInfo =
         DeclarationNameInfo(DeclarationName(&II), SourceLocation());
     LookupResult R(S, NameInfo, Sema::LookupOrdinaryName);
-    S.LookupParsedName(R, S.getCurScope(), &SS, false);
+    // AllowBuiltinCreation is false but LookupDirect will create
+    // the builtin when searching the global scope anyways...
+    S.LookupName(R, S.getCurScope());
+    // FIXME: If the builtin function was user-declared in global scope,
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erichkeane wrote:

Thats an interesting question... I think we SHOULD evaluate that, but feel free to do so in a follow up.

https://github.com/llvm/llvm-project/pull/84050