[PATCH 2/6] Use INLINE_SYSCALL_ERROR_RETURN

[Florian Weimer]

On 10/13/2015 04:00 PM, H.J. Lu wrote:
> On Tue, Oct 13, 2015 at 6:58 AM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 10/13/2015 03:56 PM, H.J. Lu wrote:
>>
>>> It looks (ptrdiff_t) isn't needed.
>>
>> It's not needed on x86_64, but we don't know if there will be
>> architectures which will eventually need it (or already do).  The
>> existing code had -1L, so I assumed it was better to play it safe and
>> mirror that.
> 
> Yes, the cast is also needed on x86-64 if __syscall_error is used:
> 
> [hjl@gnu-tools-1 tmp]$ cat x.c
> #include <stddef.h>
> 
> extern int __syscall_error (void);
> void *p;
> 
> void
> foo (void)
> {
>   p = (void *) (ptrdiff_t) __syscall_error ();
> }
> [hjl@gnu-tools-1 tmp]$

Oh, right.

I think it's best not to use the new macro in those two cases.  If the
cast is not a no-op, it's no longer a tail call, after all.

Florian