[Bug libstdc++/113376] [14/15 Regression] Confusing notes when using C++17 parallel algorithms

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113376

--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:

https://gcc.gnu.org/g:99a1fe6c12c733fe4923a75a79d09a66ff8abcec

commit r15-1255-g99a1fe6c12c733fe4923a75a79d09a66ff8abcec
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jun 12 16:47:17 2024 +0100

    libstdc++: Fix unwanted #pragma messages from PSTL headers [PR113376]

    When we rebased the PSTL on upstream, in r14-2109-g3162ca09dbdc2e, a
    change to how _PSTL_USAGE_WARNINGS is set was missed out, but the change
    to how it's tested was included. This means that the macro is always
    defined, so testing it with #ifdef (instead of using #if to test its
    value) doesn't work as intended.

    Revert the test to use #if again, since that part of the upstream change
    was unnecessary in the first place (the macro is always defined, so
    there's no need to use #ifdef to avoid -Wundef warnings).

    libstdc++-v3/ChangeLog:

            PR libstdc++/113376
            * include/pstl/pstl_config.h: Use #if instead of #ifdef to test
            the _PSTL_USAGE_WARNINGS macro.