Re: [PATCH] elfcmp: fix self-comparison error with GCC 6

[Mark Wielaard]

On Mon, 2016-04-11 at 16:00 +0200, david.abdurachma...@cern.ch wrote:
> From: David Abdurachmanov <davi...@cern.ch>
> 
> Noticed with Fedora 24 Alpha, gcc (GCC) 6.0.0 20160406
> (Red Hat 6.0.0-0.20).
> 
> elfcmp.c: In function ‘main’:
> elfcmp.c:364:199: error: self-comparison always evaluates
> to false [-Werror=tautological-compare]
>         if (unlikely (name1 == NULL || name2 == NULL
> @@ -368,7 +368,7 @@ main (int argc, char *argv[])
>                               && sym1->st_shndx != SHN_UNDEF)
>                           || sym1->st_info != sym2->st_info
>                           || sym1->st_other != sym2->st_other
> -                         || sym1->st_shndx != sym1->st_shndx))
> +                         || sym1->st_shndx != sym2->st_shndx))
>               {
>                 // XXX Do we want to allow reordered symbol tables?
>               symtab_mismatch:

Thanks! And oops. Applied since that was obviously wrong.

Nice that GCC caught that. I am slightly surprised my own GCC6 testing
didn't find this. I am using upstream gcc (GCC) 6.0.0 20160410
(experimental). Did you have to do anything special on your Fedora setup
to make GCC detect this?

Thanks,

Mark