[FFmpeg-devel] [PATCH 2/2] ffmpeg: silence unused return value warnings

[wm4]

On Sun, 26 Jul 2015 23:53:23 -0400
Ganesh Ajjanagadde <gajjanagadde at gmail.com> wrote:

> GCC throws a -Wunused-result for not checking return value
> of write(); silence it
> 
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  ffmpeg.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/ffmpeg.c b/ffmpeg.c
> index 8b5a705..6f18ab8 100644
> --- a/ffmpeg.c
> +++ b/ffmpeg.c
> @@ -329,16 +329,16 @@ sigterm_handler(int sig)
>      switch (sig) {
>          /* 2 = STDERR_FILENO */
>          case SIGSEGV:
> -            write(2, "Segmentation fault, hard exiting\n",
> -              strlen("Segmentation fault, hard exiting\n"));
> +            if(write(2, "Segmentation fault, hard exiting\n",
> +              strlen("Segmentation fault, hard exiting\n"))){};
>              abort();
>          case SIGILL:
> -            write(2, "Invalid instruction, hard exiting\n",
> -              strlen("Invalid instruction, hard exiting\n"));
> +            if(write(2, "Invalid instruction, hard exiting\n",
> +              strlen("Invalid instruction, hard exiting\n"))){};
>              abort();
>          case SIGFPE:
> -            write(2, "Arithmetic exception, hard exiting\n",
> -              strlen("Arithmetic exception, hard exiting\n"));
> +            if(write(2, "Arithmetic exception, hard exiting\n",
> +              strlen("Arithmetic exception, hard exiting\n"))){};
>              abort();
>              break;
>          default:
> @@ -346,8 +346,8 @@ sigterm_handler(int sig)
>      }
>  
>      if(received_nb_signals > 3) {
> -        write(2, "Received > 3 system signals, hard exiting\n",
> -          strlen("Received > 3 system signals, hard exiting\n"));
> +        if(write(2, "Received > 3 system signals, hard exiting\n",
> +          strlen("Received > 3 system signals, hard exiting\n"))){};
>          exit(123);
>      }
>  }

At this point, you should probably create a macro like
WRITE_SIGNAL_SAFE(), which does all this. (Also I agree
with Nicolas George that (void) is preferable.)