[ARM] Fix _unlink prototype under ARM_RDI_MONITOR.

[Christophe Lyon]

On Tue, 2 Oct 2018 at 00:15, Eric Blake <eblake@redhat.com> wrote:
>
> On 10/1/18 4:28 PM, Christophe Lyon wrote:
> > Hi,
> >
> > I noticed that "path" is actually used when compiling with
> > ARM_RDI_MONITOR, so this small patch removes the unused attribute in
> > that case.
> >
> > OK?
>
> Personally, I'd rather not take this patch.
>
>
> >   int
> > +#ifdef ARM_RDI_MONITOR
> > +_unlink (const char *path)
> > +#else
> >   _unlink (const char *path __attribute__ ((unused)))
> > +#endif
>
> GCC (and thus clang when copying it) defined __attribute__((unused)) to
> merely mean "might be unused, so suppress warnings about it being unused
> even it if turns out to be used after all", and not "must be unused, so
> warn if it actually gets used".  It is specifically designed this way so
> that you DON'T have to add a bunch of #ifdefs around code to apply the
> attribute. If there is at least one path through the rest of a
> function's existing #ifdef maze where the attribute matters, then use
> the attribute unconditionally, rather than making the #ifdef maze worse.
>

OK, makes sense.

Thanks

> --
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3266
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