-fms-extensions: Add __va_start builtin, which is used for x64

The main difference between __va_start and __builtin_va_start is that
the address of the va_list has already been taken, and the va_list is
always a char*.

__va_end and __va_arg are not needed.

llvm-svn: 204821

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/test/Sema/MicrosoftExtensions.c b/clang/test/Sema/MicrosoftExtensions.c
index 4441f179736..a4afcb1e640 100644
--- a/clang/test/Sema/MicrosoftExtensions.c
+++ b/clang/test/Sema/MicrosoftExtensions.c
@@ -131,3 +131,17 @@ int *(__ptr32 __sptr wrong9); // expected-error {{'__sptr' attribute only applie
 
 typedef int *T;
 T __ptr32 wrong10; // expected-error {{'__ptr32' attribute only applies to pointer arguments}}
+
+typedef char *my_va_list;
+void __cdecl __va_start(my_va_list *ap, ...); // expected-note {{passing argument to parameter 'ap' here}}
+void vmyprintf(const char *f, my_va_list ap);
+void myprintf(const char *f, ...) {
+  my_va_list ap;
+  if (1) {
+    __va_start(&ap, f);
+    vmyprintf(f, ap);
+    ap = 0;
+  } else {
+    __va_start(ap, f); // expected-warning {{incompatible pointer types passing 'my_va_list'}}
+  }
+}