Re: Warnings to be fixed

[Jim Meyering]

Reuben Thomas <address@hidden> wrote:
> Compiling with the Debian gnulib snapshot of 20081001, I am delighted
> that I no longer get warnings about #include_next. (Un?)fortunately,
> this enables me more easily to spot "real" warnings:
...
> open-safer.c: In function ‘open_safer’:
> open-safer.c:43: warning: signed and unsigned type in conditional expression

This one is perhaps a good reason to turn off or ignore that warning,
at least for this particular case:

int
open_safer (char const *file, int flags, ...)
{
  mode_t mode = 0;

  if (flags & O_CREAT)
    {
      va_list ap;
      va_start (ap, flags);

      /* Assume mode_t promotes to int if and only if it is smaller.
         This assumption isn't guaranteed by the C standard, but we
         don't know of any real-world counterexamples.  */
      mode = (sizeof (mode_t) < sizeof (int)
              ? va_arg (ap, int)
              : va_arg (ap, mode_t));    <<<============ line 43

      va_end (ap);
    }

  return fd_safer (open (file, flags, mode));
}

IMHO, adding casts here just to avoid that warning would be
counterproductive.