Re: New -Werror=restrict error with incremental gcc

[Laura Abbott]

On 03/15/2018 08:11 PM, Josh Poimboeuf wrote:
> On Thu, Mar 15, 2018 at 08:06:26AM -0700, Laura Abbott wrote:
> > This only showed up with the very latest rawhide snapshot, .17 worked and
> > .18 started failing. I had to download .18 manually to test locally
> > https://koji.fedoraproject.org/koji/packageinfo?packageID=40
>
> I also see the error with the latest gcc master branch.  The code is
> harmless, but maybe the warning is useful in other places, so here's one
> way to fix it.

Works for me, you can add

Tested-by: Laura Abbott <labbott@xxxxxxxxxx>

> ----
>
> From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Subject: [PATCH] objtool, perf: Fix GCC 8 -Wrestrict error
>
> Starting with recent GCC 8 builds, objtool and perf fail to build with
> the following error:
>
>    ../str_error_r.c: In function âstr_error_râ:
>    ../str_error_r.c:25:3: error: passing argument 1 to restrict-qualified parameter aliases with argument 5 [-Werror=restrict]
>       snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
>
> The code seems harmless, but there's probably no benefit in printing the
> 'buf' pointer in this situation anyway, so just remove it to make GCC
> happy.
>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
>   tools/lib/str_error_r.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/str_error_r.c b/tools/lib/str_error_r.c
> index d6d65537b0d9..6aad8308a0ac 100644
> --- a/tools/lib/str_error_r.c
> +++ b/tools/lib/str_error_r.c
> @@ -22,6 +22,6 @@ char *str_error_r(int errnum, char *buf, size_t buflen)
>   {
>   	int err = strerror_r(errnum, buf, buflen);
>   	if (err)
> -		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
> +		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, [buf], %zd)=%d", errnum, buflen, err);
>   	return buf;
>   }