On Fri, May 05, 2023 at 01:13:50PM +0200, Florian Weimer via Gcc-bugs wrote:
> * Puneet Kumar Yatnal via Gcc-bugs:
>
> > What is next step here? How do I post this in Bugzilla and get
> > support.
>
> This issue has already been fixed with this commit:
>
> commit 80fe172ba9820199c2bbce5d0611ffca27823049
> Author: Jonathan Wakely <jwakely@xxxxxxxxxx>
> Date: Tue Nov 9 23:45:36 2021 +0000
>
> libstdc++: Disable gthreads weak symbols for glibc 2.34 [PR103133]
>
> Since Glibc 2.34 all pthreads symbols are defined directly in libc not
> libpthread, and since Glibc 2.32 we have used __libc_single_threaded to
> avoid unnecessary locking in single-threaded programs. This means there
> is no reason to avoid linking to libpthread now, and so no reason to use
> weak symbols defined in gthr-posix.h for all the pthread_xxx functions.
>
> libstdc++-v3/ChangeLog:
>
> PR libstdc++/100748
> PR libstdc++/103133
> * config/os/gnu-linux/os_defines.h (_GLIBCXX_GTHREAD_USE_WEAK):
> Define for glibc 2.34 and later.
>
> It's been backported to GCC 10, but not GCC 9. Backporting to 9
> requires some messaging to get into 9 which lacks commit
> b11cbbbb74b0e357652a1f1f0d93 ("libstdc++: Avoid calling undefined
> __gthread_self weak symbol [PR 95989]").
GCC 9 is not supported anymore, so backporting anything to it (at least
upstream) is not possible.
Jakub
