Re: [PATCH] Add __BEGIN_DECLS and __END_DECLS for C++

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Thu, May 11, 2017 at 8:33 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, May 11, 2017 at 8:20 AM, Zack Weinberg <zackw@panix.com> wrote:
>> On Thu, May 11, 2017 at 11:10 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Thu, May 11, 2017 at 7:57 AM, Zack Weinberg <zackw@panix.com> wrote:
>>>> On Thu, May 11, 2017 at 10:45 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>>> On Thu, May 11, 2017 at 7:43 AM, Zack Weinberg <zackw@panix.com> wrote:
>>>>>>
>>>>>> This program does not appear to need ifunc-impl-list.h.  Please elaborate.
>>>>>
>>>>> Please see hjl/x86/optimize branch in glibc git repo.
>>>>
>>>> I don't especially appreciate being made to dig through a bunch of
>>>> code I'm unfamiliar with.  It would have been easy for you to write
>>>> "The existing benchtests framework uses ifunc-impl-list.h to iterate
>>>> over all ifunc implementations of a particular string function.  This
>>>> works as long as the test program is C, but I want to integrate a
>>>> third-party benchmark <url> written in C++, so I need to make
>>>> ifunc-impl-list.h C++-safe".  If that had accompanied the original
>>>> patch it would have been better all around.
>>>>
>>>> It looks to me as if IFUNC_IMPL_ADD is not C++-safe and cannot easily
>>>
>>> IFUNC_IMPL_ADD is only used in ifunc-impl-list.c, which is the
>>> part of libc and in C.
>>
>> Can IFUNC_IMPL_ADD be removed from ifunc-impl-list.h then?  I would be
>> okay with adding __BEGIN_DECLS/__END_DECLS to the header as long as
>> all of the code within it -- including macros -- was safe for use from
>> C++ programs, and with a comment explaining that the header may get
>> used from C++ benchmarks.
>
> IFUNC_IMPL_ADD is used in
>
> sysdeps/arm/armv7/multiarch/ifunc-impl-list.c
> sysdeps/i386/i686/multiarch/ifunc-impl-list.c
> sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c
> sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
> sysdeps/s390/multiarch/ifunc-impl-list.c
> sysdeps/sparc/sparc64/multiarch/ifunc-impl-list.c
> sysdeps/x86_64/multiarch/ifunc-impl-list.c
>
> Removing it from include/ifunc-impl-list.h isn't appropriate.  Here is
> the updated patch with comments.
>

Ping.


-- 
H.J.