c/objc: problem originally reported as an objective-c bug.

But it is in the underlying c part of clang. clang crashes
in IRGen when passing an incomplete type argument to 
variadic function (instead of diagnosing the bug).
// rdar://10961370


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151862 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 149201192f..6deffa2abd 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -587,6 +587,12 @@ ExprResult Sema::DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT,
       E = Comma.get();
     }
   }
+  // c++ rules are enfroced elsewhere.
+  if (!getLangOptions().CPlusPlus &&
+      !E->getType()->isVoidType() &&
+      RequireCompleteType(E->getExprLoc(), E->getType(),
+                          diag::err_incomplete_type))
+    return ExprError();
   
   return Owned(E);
 }