Check for Nullness of value built in GetObjcProtoType.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@43155 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Sema/SemaExpr.cpp b/Sema/SemaExpr.cpp
index 281e524..795f6da 100644
--- a/Sema/SemaExpr.cpp
+++ b/Sema/SemaExpr.cpp
@@ -1947,6 +1947,8 @@
   }
   
   QualType t = GetObjcProtoType(AtLoc);
+  if (t.isNull())
+    return true;
   return new ObjCProtocolExpr(t, PDecl, AtLoc, RParenLoc);
 }