[FFmpeg-devel] [PATCH 1/8] libavdevice/v4l2.c: fix build warning

[Anton Khirnov]

Quoting Guo, Yejun (2021-02-20 08:22:11)
> Here is the warning message:
> src/libavdevice/v4l2.c: In function ‘v4l2_get_device_list’:
> src/libavdevice/v4l2.c:1054:58: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 251 [-Wformat-truncation=]
>          snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
>                                                           ^~
> src/libavdevice/v4l2.c:1054:9: note: ‘snprintf’ output between 6 and 261 bytes into a destination of size 256
>          snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ---
> This patch set fixes build warnings during make on my system
> with gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
> with config option:
> --disable-optimizations --enable-libx264 --enable-libx265 --enable-gpl --enable-libvpx --enable-libmfx --extra-cflags="-Wno-deprecated-declarations"
> 
> I also tried '-Wall -Werror', there are many many issues starting from
> configure. It is a long term task, let's fix one by one when have time.
> 
>  libavdevice/v4l2.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
> index 365bacd771..15ade26eed 100644
> --- a/libavdevice/v4l2.c
> +++ b/libavdevice/v4l2.c
> @@ -1046,7 +1046,7 @@ static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_l
>          return ret;
>      }
>      while ((entry = readdir(dir))) {
> -        char device_name[256];
> +        char device_name[261];

sizeof(entry->d_name) + 5
would be eaiser to read IMO

-- 
Anton Khirnov