Add diagnostic for constructs like "va_arg(l, float)" which have undefined behavior. PR10201.

llvm-svn: 134926

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/test/Sema/varargs.c b/clang/test/Sema/varargs.c
index 820567777c5..07081edd1d9 100644
--- a/clang/test/Sema/varargs.c
+++ b/clang/test/Sema/varargs.c
@@ -67,3 +67,12 @@ void f8(int a, ...) {
   (void)__builtin_va_arg(ap, void); // expected-error {{second argument to 'va_arg' is of incomplete type 'void'}}
   __builtin_va_end(ap);
 }
+
+enum E { x = -1, y = 2, z = 10000 };
+void f9(__builtin_va_list args)
+{
+    (void)__builtin_va_arg(args, float); // expected-warning {{second argument to 'va_arg' is of promotable type 'float'}}
+    (void)__builtin_va_arg(args, enum E); // Don't warn here in C
+    (void)__builtin_va_arg(args, short); // expected-warning {{second argument to 'va_arg' is of promotable type 'short'}}
+    (void)__builtin_va_arg(args, char); // expected-warning {{second argument to 'va_arg' is of promotable type 'char'}}
+}