Re: [PATCH RFC] c++: use __cxa_call_terminate for MUST_NOT_THROW [PR97720]

[Richard Biener <richard.guenther@gmail.com>]

On Thu, Jun 8, 2023 at 3:14 PM Jonathan Wakely via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Fri, 26 May 2023 at 10:58, Jonathan Wakely wrote:
>
> >
> >
> > On Wed, 24 May 2023 at 19:56, Jason Merrill via Libstdc++ <
> > libstdc++@gcc.gnu.org> wrote:
> >
> >> Middle-end folks: any thoughts about how best to make the change
> >> described in
> >> the last paragraph below?
> >>
> >> Library folks: any thoughts on the changes to __cxa_call_terminate?
> >>
> >
> > I see no harm in exporting it (with the adjusted signature). The "looks
> > standard but isn't" name is a little unfortunate, but not a big deal.
> >
>
> Jason, do you have any objection to exporting __cxa_call_terminate for GCC
> 13.2 as well, even though the FE won't use it?
>
> Currently both gcc-13 and trunk are at the same library version,
> libstdc++.so.6.0.32
>
> But with this addition to trunk we need to bump that .32 to .33, meaning
> that gcc-13 and trunk diverge. If we want to backport any new symbols from
> trunk to gcc-13 that gets trickier once they've diverged.

But if you backport any new used symbol you have to bump the version
anyway.  So why not bump now (on trunk)?

> If we added __cxa_call_terminate to gcc-13, making it another new addition
> to libstdc++.so.6.0.32, then it would simplify a few things.
>
> In theory it could be a problem for distros already shipping gcc-13.1.1
> with that new libstdc++.so.6.0.32 version, but since the
> __cxa_call_terminate symbol won't actually be used by the gcc-13.1.1
> compilers, I don't think it will be a problem.