libvhost-user: Add format attribute to local function vu_panic

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220422070144.1043697-4-sw@weilnetz.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221126152507.283271-5-sw@weilnetz.de>

subprojects/libvhost-user/libvhost-user.c

@@ -45,6 +45,17 @@
 #include "libvhost-user.h"
 
 /* usually provided by GLib */
+#if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+#if !defined(__clang__) && (__GNUC__ == 4 && __GNUC_MINOR__ == 4)
+#define G_GNUC_PRINTF(format_idx, arg_idx) \
+  __attribute__((__format__(gnu_printf, format_idx, arg_idx)))
+#else
+#define G_GNUC_PRINTF(format_idx, arg_idx) \
+  __attribute__((__format__(__printf__, format_idx, arg_idx)))
+#endif
+#else   /* !__GNUC__ */
+#define G_GNUC_PRINTF(format_idx, arg_idx)
+#endif  /* !__GNUC__ */
 #ifndef MIN
 #define MIN(x, y) ({                            \
             typeof(x) _min1 = (x);              \
@@ -151,7 +162,7 @@ vu_request_to_string(unsigned int req)
     }
 }
 
-static void
+static void G_GNUC_PRINTF(2, 3)
 vu_panic(VuDev *dev, const char *msg, ...)
 {
     char *buf = NULL;