Re: [PATCH] build: Fix ax_pthread.m4 on Solaris 11.4

On Fri, May 15, 2026 at 12:31 PM Rainer Orth
<[email protected]> wrote:
>
> As uncovered by PR testsuite/125310, libcaf_shmem isn't built on
> Solaris.  This happens because the AX_PTHREAD autoconf macro erroneously
> thinks that Solaris lacks pthreads support.
>
> The problem is that the macros expects _REENTRANT to be defined in
> multithreaded programs.  However, as described in
> https://gcc.gnu.org/gcc-16/porting_to.html#solaris the Solaris 11.4
> system headers no longer reference _REENTRANT, so GCC 16 doesn't define
> it any longer.
>
> The issue is still present in current ax_pthread.m4 (serial 31) in the
> autoconf archive.  This patch fixes this by only requiring _REENTRANT in
> older Solaris versions that still need it by checking for pre-XPG7
> system headers.
>
> Bootstrapped without regressions on i386-pc-solaris2.11 and
> sparc-sun-solaris2.11.  Also tested manually on Solaris 11.3.
>
> Ok for trunk?
>
>         Rainer
>

ax_pthread.m4 is imported from the autoconf-archive, isn't it?
Shouldn't this patch go there first?

> --
> -----------------------------------------------------------------------------
> Rainer Orth, Center for Biotechnology, Bielefeld University
>
>
> 2026-05-14  Rainer Orth  <[email protected]>
>
>         config:
>         * ax_pthread.m4 (ax_pthread_check_macro) <solaris*>: Only require
>         _REENTRANT before Solaris 11.4
>
>         libgfortran:
>         * configure: Regenerate.
>