Re: fix some gcc warnings

[Pádraig Brady]

On 16/10/16 16:01, Bruno Haible wrote:
> Hi,
> 
> When I compile a gnulib testdir with "gcc -Wall", I see the following warnings
> (among others):
> 
> test-ffsl.c: In function 'main':
> test-ffsl.c:44:12: warning: unused variable 'x' [-Wunused-variable]
> 
> test-posix_spawn3.c: In function 'parent_main':
> test-posix_spawn3.c:78:11: warning: ignoring return value of 'freopen', 
> declared with attribute warn_unused_result [-Wunused-result]
> 
> test-sethostname1.c: In function 'main':
> test-sethostname1.c:34:17: warning: ignoring return value of 'sethostname', 
> declared with attribute warn_unused_result [-Wunused-result]
> 
> Here's a proposed fix for them.
> 
> 
> 2016-10-16  Bruno Haible  <address@hidden>
> 
>       Fix some "gcc -Wall" warnings.
>       * tests/test-ffsl.c (main): Use variable x, not i.
>       * tests/test-posix_spawn3.c (parent_main): Consider the return value of
>       freopen.
>       * tests/test-sethostname1.c (main): Explicitly ignore the return value
>       of sethostname.
> 
> diff --git a/tests/test-ffsl.c b/tests/test-ffsl.c
> index e903509..117bc4a 100644
> --- a/tests/test-ffsl.c
> +++ b/tests/test-ffsl.c
> @@ -44,8 +44,8 @@ main (int argc, char *argv[])
>    long int x;
>    int i;
>  
> -  for (i = -128; i <= 128; i++)
> -    ASSERT (ffsl (i) == naive (i));
> +  for (x = -128; x <= 128; x++)
> +    ASSERT (ffsl (x) == naive (x));
>    for (i = 0; i < NBITS; i++)
>      {
>        ASSERT (ffsl (1UL << i) == naive (1UL << i));
> diff --git a/tests/test-posix_spawn3.c b/tests/test-posix_spawn3.c
> index 90745fd..f2a699c 100644
> --- a/tests/test-posix_spawn3.c
> +++ b/tests/test-posix_spawn3.c
> @@ -75,7 +75,11 @@ parent_main (void)
>      }
>  
>    /* Avoid reading from our stdin, as it could block.  */
> -  freopen ("/dev/null", "rb", stdin);
> +  if (freopen ("/dev/null", "rb", stdin) == NULL)
> +    {
> +      perror ("cannot redirect stdin");
> +      return 1;
> +    }
>  
>    /* Test whether posix_spawn_file_actions_addopen with this file name
>       actually works, but spawning a child that reads from this file.  */
> diff --git a/tests/test-sethostname1.c b/tests/test-sethostname1.c
> index 5ed6a83..08441f3 100644
> --- a/tests/test-sethostname1.c
> +++ b/tests/test-sethostname1.c
> @@ -30,8 +30,11 @@ main ()
>    /* Some code that has a link-time dependency to the sethostname() function
>       and that is likely not optimized away by compilers.  */
>    if (do_dangerous_things)
> -    /* Never executed.  */
> -    sethostname ("oprah", 5);
> +    {
> +      /* Never executed.  */
> +      int ret = sethostname ("oprah", 5);
> +      (void) ret;
> +    }
>  
>    return 0;
>  }
> 
> 
> 

+1
thanks