[Bug libstdc++/104217] [12 Regression] gcc-12-20220123 failure to build on Cygwin due to lack of secure_getenv

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104217

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jonathan Wakely
<r...@gcc.gnu.org>:

https://gcc.gnu.org/g:8562fbaae9d0c06316188c4749a2171071b6b926

commit r11-9971-g8562fbaae9d0c06316188c4749a2171071b6b926
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Tue Jan 25 10:11:36 2022 +0000

    libstdc++: Define _GNU_SOURCE for secure_getenv on Cygwin [PR104217]

    For GNU/Linux G++ defines _GNU_SOURCE automatically, but not for Cygwin.
    This means secure_getenv is not declared by Cygwin's <stdlib.h>, even
    though autoconf detected it is present in the library. Define it in the
    source files that want to use secure_getenv.

    libstdc++-v3/ChangeLog:

            PR libstdc++/104217
            * src/c++17/fs_ops.cc (_GNU_SOURCE): Define.
            * src/filesystem/dir.cc (_GNU_SOURCE): Define.
            * src/filesystem/ops.cc (_GNU_SOURCE): Define.

    (cherry picked from commit e20486d508afdf22790a271e90ca76d8df5fa7a5)