Re: [PATCH] bpftool: optimize if statement code

[Quentin Monnet <qmo@kernel.org>]

2024-10-15 19:09 UTC+0800 ~ Liu Jing <liujing@cmss.chinamobile.com>
> Since both conditions are used to check whether len is valid, we can combine the two conditions into a single if statement
> Signed-off-by: Liu Jing <liujing@cmss.chinamobile.com>
> ---
>   tools/bpf/bpftool/feature.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c
> index 4dbc4fcdf473..0121e0fd6949 100644
> --- a/tools/bpf/bpftool/feature.c
> +++ b/tools/bpf/bpftool/feature.c
> @@ -158,10 +158,9 @@ static int get_vendor_id(int ifindex)
>   
>   	len = read(fd, buf, sizeof(buf));
>   	close(fd);
> -	if (len < 0)
> -		return -1;
> -	if (len >= (ssize_t)sizeof(buf))
> +	if ((len < 0) || (len >= (ssize_t)sizeof(buf)))
>   		return -1;
> +
>   	buf[len] = '\0';
>   
>   	return strtol(buf, NULL, 0);


Thanks. I'm not strictly opposed to the change, but it doesn't bring 
much value in my opinion. I don't think this will "optimize" the 
statement beyond what the compiler does already.

Quentin