Move macros GCC_ATTR and GCC_FMT_ATTR to common header file

By moving the definition of GCC_ATTR and GCC_FMT_ATTR
from audio_int.h to qemu-common.h these macros are
now generally available for further patches which add
the gcc format attribute.

Newer gcc versions support format gnu_printf which is
better suited for use in QEMU than format printf
(QEMU always uses standard format strings (even with mingw32)).

V2: Use correct operator '==' (instead of '=')

Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

audio/audio_int.h

@@ -236,14 +236,6 @@ static inline int audio_ring_dist (int dst, int src, int len)
     return (dst >= src) ? (dst - src) : (len - src + dst);
 }
 
-#if defined __GNUC__
-#define GCC_ATTR __attribute__ ((__unused__, __format__ (__printf__, 1, 2)))
-#define GCC_FMT_ATTR(n, m) __attribute__ ((__format__ (__printf__, n, m)))
-#else
-#define GCC_ATTR /**/
-#define GCC_FMT_ATTR(n, m)
-#endif
-
 static void GCC_ATTR dolog (const char *fmt, ...)
 {
     va_list ap;

qemu-common.h

@@ -70,6 +70,22 @@ struct iovec {
 #include <sys/uio.h>
 #endif
 
+#if defined __GNUC__
+# if (__GNUC__ < 4) || \
+     defined(__GNUC_MINOR__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 4)
+   /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
+#  define GCC_ATTR __attribute__((__unused__, format(printf, 1, 2)))
+#  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
+# else
+   /* Use gnu_printf when supported (qemu uses standard format strings). */
+#  define GCC_ATTR __attribute__((__unused__, format(gnu_printf, 1, 2)))
+#  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
+# endif
+#else
+#define GCC_ATTR /**/
+#define GCC_FMT_ATTR(n, m)
+#endif
+
 #ifdef _WIN32
 #define fsync _commit
 #define lseek _lseeki64