1 files changed, 8 insertions, 1 deletions
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e9e0f5e214d..c8973ae100e 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13386,7 +13386,14 @@ CreateNewDecl:
   OwnedDecl = true;
   // In C++, don't return an invalid declaration. We can't recover well from
   // the cases where we make the type anonymous.
-  return (Invalid && getLangOpts().CPlusPlus) ? nullptr : New;
+  if (Invalid && getLangOpts().CPlusPlus) {
+    if (New->isBeingDefined())
+      if (auto RD = dyn_cast<RecordDecl>(New))
+        RD->completeDefinition();
+    return nullptr;
+  } else {
+    return New;
+  }
 }
 
 void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) {