From: Joe Perches <joe@perches.com>
Date: Mon, 27 Aug 2007 13:57:42 -0700

On Mon, 2007-08-27 at 13:41 -0700, David Miller wrote:

quoted

From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 27 Aug 2007 12:54:09 +0200

quoted

#define MAC_FMT "%s"
#define MAC_ARG(a) ({char __buf[18]; print_mac(a, __buf); __buf;})

quoted

I don't think this works.

$ cat test_fmt.c
#include <stdio.h>
#include <stdlib.h>

You're just getting lucky in this test case.

The language does not allow what you are doing, so you're
playing with fire.