[Bug fortran/125324] -fcoarray=shared should imply -pthread / gfortran.dg/coarray_51.f90 FAILs with undefined reference to `pthread_mutex_trylock'

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125324

--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-16 branch has been updated by Jerry DeLisle
<jvdeli...@gcc.gnu.org>:

https://gcc.gnu.org/g:90f250aa6dc1d671581f3149e3d5a5491b5d68fb

commit r16-9705-g90f250aa6dc1d671581f3149e3d5a5491b5d68fb
Author: Jerry DeLisle <jvdeli...@gcc.gnu.org>
Date:   Wed May 27 09:24:26 2026 -0700

    fortran: also link -lpthread when -fcoarray=shared is used [PR125324]

    When the driver auto-links -lcaf_shmem for -fcoarray=shared it must also
    link -lpthread because the shmem CAF runtime uses POSIX threads internally.

    Assisted by: Claude Sonnet 4.6

            PR fortran/125324

    gcc/fortran/ChangeLog:

            * gfortranspec.cc (lang_specific_driver): Also append -lpthread
            when need_caf_shmem is set.

    (cherry picked from commit ee7d0c7b4102b8ef0bcaa725c75e141248b774cb)