A field of incomplete type is sufficiently disruptive that we should mark
the record invalid.

llvm-svn: 111211
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index cc6e2fa..b7b802a 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5955,8 +5955,11 @@
 
   QualType EltTy = Context.getBaseElementType(T);
   if (!EltTy->isDependentType() &&
-      RequireCompleteType(Loc, EltTy, diag::err_field_incomplete))
+      RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) {
+    // Fields of incomplete type force their record to be invalid.
+    Record->setInvalidDecl();
     InvalidDecl = true;
+  }
 
   // C99 6.7.2.1p8: A member of a structure or union may have any type other
   // than a variably modified type.