[clang] [clang] Reject incomplete type arguments for __builtin_dump_struct (PR #72749)

[Richard Smith via cfe-commits]

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@@ -713,6 +713,11 @@ static ExprResult SemaBuiltinDumpStruct(Sema &S, CallExpr *TheCall) {
     return ExprError();
   }
   const RecordDecl *RD = PtrArgType->getPointeeType()->getAsRecordDecl();
+  if (!RD->isCompleteDefinition()) {
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zygoloid wrote:

You need to use `RequireCompleteType` here to properly trigger instantiation of templated classes and handle definition visibility checking for modules.

https://github.com/llvm/llvm-project/pull/72749