rtl8139: add format attribute to DPRINTF

gcc can check the format string for correctness even when debugging output is
not enabled.
Have to make sure arguments are always available. They are optimized out if
unneeded.

Signed-off-by: Benjamin Poirier <benjamin.poirier@gmail.com>
Cc: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 13b14e4e106b69ec98461fdd03388bed07731f3b..cbf667a301241909855eac0904b54b2918007d6e 100644 (file)
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -88,7 +88,11 @@
 #  define DPRINTF(fmt, ...) \
     do { fprintf(stderr, "RTL8139: " fmt, ## __VA_ARGS__); } while (0)
 #else
-#  define DPRINTF(fmt, ...) do { } while (0)
+static inline __attribute__ ((format (printf, 1, 2)))
+    int DPRINTF(const char *fmt, ...)
+{
+    return 0;
+}
 #endif
 
 /* Symbolic offsets to registers. */
@@ -2201,9 +2205,8 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
 
                 if ((txdw0 & CP_TX_LGSEN) && ip_protocol == IP_PROTO_TCP)
                 {
-#if defined (DEBUG_RTL8139)
                     int large_send_mss = (txdw0 >> 16) & CP_TC_LGSEN_MSS_MASK;
-#endif
+
                     DPRINTF("+++ C+ mode offloaded task TSO MTU=%d IP data %d "
                         "frame data %d specified MSS=%d\n", ETH_MTU,
                         ip_data_len, saved_size - ETH_HLEN, large_send_mss);