gcov: use no-op functions if not enabled

Instead of wrapping every gcov function call in an ifdef.

Note: The usage of `((void)0)` is based on section 7.2 of the C99
standard (N1256)[1] [2]:

> 7.2 Diagnostics <assert.h>
>
> 1 The header <assert.h> defines the assert macro and refers to another
> macro,
>
>     NDEBUG
>
> which is not defined by <assert.h>. If NDEBUG is defined as a macro
> name at the point in the source file where <assert.h> is included, the
> assert macro is defined simply as
>
>     #define assert(ignore) ((void)0)

See also assert.h(0p) from POSIX.1-2017[3].

Note: This is a continuation of commit b408b20c7 ("gcov: fix build
failure with gcc 11.1.0") / PR #4373.

[1] http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1256.pdf
[2] https://port70.net/~nsz/c/c99/n1256.html#7.2
[3] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/assert.h.html

1 files changed, 2 insertions, 6 deletions

diff --git a/src/firemon/netstats.c b/src/firemon/netstats.c
index 205ad7601..9d8e5d7f5 100644
--- a/src/firemon/netstats.c
+++ b/src/firemon/netstats.c
@@ -18,16 +18,13 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 #include "firemon.h"
+#include "../include/gcov_wrapper.h"
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
-#ifdef HAVE_GCOV
-#include "../include/gcov_wrapper.h"
-#endif
-
 #define MAXBUF 4096
 
 // ip -s link: device stats
@@ -246,8 +243,7 @@ void netstats(void) {
                                 print_proc(i, itv, col);
                         }
                 }
-#ifdef HAVE_GCOV
+
                 __gcov_flush();
-#endif
         }
 }