Simplify some va_start checking logic

Combine the logic doing the ms_abi/sysv_abi checks into one function so
that each check and its logical opposite are near each other. Now we
don't need two Sema entry points for MS va_start and regular va_start.

Refactor the code that checks if the va_start caller is a function,
block, or obj-c method. We do this in three places, and they are all
buggy for variadic lambdas (PR32737). After this change, I have one
place to apply the functional fix.

NFC

llvm-svn: 301968

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/test/Sema/varargs.c b/clang/test/Sema/varargs.c
index 25a5c72c42e..0ade0cf0aaf 100644
--- a/clang/test/Sema/varargs.c
+++ b/clang/test/Sema/varargs.c
@@ -27,7 +27,7 @@ void f3(float a, ...) { // expected-note 2{{parameter of type 'float' is declare
 }
 
 
-// stdarg: PR3075
+// stdarg: PR3075 and PR2531
 void f4(const char *msg, ...) {
  __builtin_va_list ap;
  __builtin_stdarg_start((ap), (msg));