[Bug libstdc++/42813] --enable-build-with-cxx libstdc++-v3 is incomplete

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42813

--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Kyrylo Tkachov <ktkachov@gcc.gnu.org>:

https://gcc.gnu.org/g:bf2aada7d8a4f701365d260a56cb7669a6934c3e

commit r17-3332-gbf2aada7d8a4f701365d260a56cb7669a6934c3e
Author: Kyrylo Tkachov <ktkachov@nvidia.com>
Date:   Tue Aug 11 09:58:40 2026 +0200

    toplevel: do not make libstdc++ configure wait for libgomp

    libstdc++'s configure was made to depend on libgomp's configure by
    r0-83445-g6d3b5aea0bf4c9 ("configure.ac (TOPLEVEL_CONFIGURE_ARGUMENTS):
Move
    libgomp before libstdc++.", 2007-09-20), when GLIBCXX_ENABLE_PARALLEL
decided
    whether to enable parallel mode by looking for a configured libgomp/omp.h
on
    disk:

      if test -f $glibcxx_builddir/../libgomp/omp.h; then

    r0-98141-gaae29963cf81dd ("PR libstdc++/36101, PR libstdc++/42813",
    2010-01-22) replaced that with

      if echo " ${TARGET_CONFIGDIRS} " | grep " libgomp " > /dev/null 2>&1 ;
then

    so the test now reads a string the top level passes in, and nothing has to
    exist on disk by then.  The comment above it still describes the old
    behaviour, which is what makes the edge look necessary.

    Remove it.  The build time dependency, all-target-libstdc++-v3 on
    configure-target-libgomp, stays, since the parallel mode headers do include
    omp.h when they are compiled.

    This shortens the chain in front of libstdc++, which is the last thing to
    finish in every bootstrap stage.

    Bootstrapped on aarch64-none-linux-gnu.

    ChangeLog:

            * Makefile.def (dependencies): Remove the
configure-target-libstdc++-v3
            on configure-target-libgomp dependency.
            * Makefile.in: Regenerate.

    Signed-off-by: Kyrylo Tkachov <ktkachov@nvidia.com>