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

llvm-svn: 151862

2 files changed, 18 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 149201192f3..6deffa2abd3 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/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);
 }
diff --git a/clang/test/Sema/variadic-incomplete-arg-type.c b/clang/test/Sema/variadic-incomplete-arg-type.c
new file mode 100644
index 00000000000..1306173a0ef
--- /dev/null
+++ b/clang/test/Sema/variadic-incomplete-arg-type.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify 
+// rdar://10961370
+
+typedef struct __CFError * CFErrorRef; // expected-note {{forward declaration of 'struct __CFError'}}
+
+void junk(int, ...);
+
+int main()
+{
+ CFErrorRef error;
+ junk(1, *error); // expected-error {{incomplete type 'struct __CFError' where a complete type is required}}
+}