free() and implicit conversion to a function pointer (was: Use of initialized variable in strtod.c)

[Bob Dunlop]

On Thu, Mar 16 at 10:04, Joel Sherrill wrote:
> 
> On 3/16/2017 3:39 AM, Corinna Vinschen wrote:
> > On Mar 15 18:48, Jeffrey Walton wrote:
> >>> But this in __call_atexit.c is definitely correct. It is
> >>> treating free() as a weak symbol and the only way to
> >>> silence Coverity is to add an annotation.
> >>>
> >>> 136      /* Don't dynamically free the atexit array if free is not
> >>> 137         available.  */
> >>>
> >>> CID 175323 (#1 of 1): Function address comparison (BAD_COMPARE)
> >>> func_conv: This implicit conversion to a function pointer is suspicious:
> >>> free.
> >>>         Did you intend to call free?
> >>> 138      if (!free)
> >>> 139        break;
> >>
> >> Well, I have not encountered that one (yet). Since Coverity is
> >> complaining about an implicit conversion, maybe the following will
> >> help to avoid the implicit part (and sidestep the finding):
> >>
> >>     if (free != NULL)
> >>         break;
> >>
> >> Or perhaps:
> >>
> >>     if ((void*)free != NULL)
> >>         break;
> >>
> >> If that works to clear the finding, then it is one of those items I
> >> write-off as "working and playing well with the tools".
> >
> > Unfortunately you have to tell covreity that "free" is a var, not a function,
> > but since that's not generally true... marking as false positive.
> >
> 
> Looks like the second option resolves the issue. No Coverity specific
> markup at all. It seems better to be explicit since comparing a function
> name to NULL directly is rather unusual.
> 
> --joel


Have you not just inverted the sense of the test as well.
Shouldn't it be:

    if ((void*)free == NULL)
	break;

-- 
        Bob Dunlop