Fix struct sigaltstack namespace (bug 21517)

[Florian Weimer]

On 06/12/2017 11:15 PM, Khem Raj wrote:
> On Sat, Jun 3, 2017 at 8:55 AM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 05/25/2017 12:32 AM, Joseph Myers wrote:
>>> +* The stack_t type no longer has the name struct sigaltstack.  This changes
>>> +  the C++ name mangling for interfaces involving this type.
>>
>> I checked Fedora and we don't seem to have any ABI impact from this
>> change (no exported symbols matching /^_Z.*sigaltstack/), so this is
>> probably fine.
> 
> I think gcc sanitizers will have issues since they are using
> the forward declaration of sigaltstack
> 
> see
> https://github.com/gcc-mirror/gcc/blob/master/libsanitizer/sanitizer_common/sanitizer_linux.h#L22

There's already a bug for that:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81066

There is no ABI impact, so this is fixable.

Thanks,
Florian