[PATCH v1] libstdc++-v3: Update VTV vars for libtool link commands [PR99172]

[Caroline Tice]

Adding the libstdc++ mailing list to the patch.

-- Caroline
cmtice@google.com

On Wed, Mar 10, 2021 at 8:50 PM Caroline Tice <cmtice@google.com> wrote:
>
> This patch is to fix PR 99172.
>
> Currently when GCC is configured with --enable-vtable-verify, the
> libstdc++-v3 Makefiles add "-fvtable-verify=std
> -Wl,-u_vtable_map_vars_start,-u_vtable_map_vars_end" to libtool link
> commands. The "-fvtable-verify=std" piece causes alternate versions of
> libtool (such as slibtool) to fail, unable to find "-lvtv" (GNU
> libtool just removes that piece).
>
> This patch updates the libstdc++-v3 Makefiles to not pass
> "-fvtable-verify=std" to the libtool link commands, while continuing
> to pass the rest of the VTV  flags (which are necessary for VTV to
> work).
>
> I tested this by configuring with --enable-vtable-verify, boostrapping
> the compiler, and running all the regression testsuites (including
> libvtv & libstdc++) without any regressions.  I only ran it on a linux
> system, on an x86_64 machine.
>
> I also gave a copy of the patch to the person who reported the bug,
> and they verified that the patch fixes their issue.
>
> Is this ok to commit?
>
> -- Caroline Tice
> cmtice@google.com
>
> libstdc++-v3/ChangeLog
>
> 2021-03-10  Caroline Tice  <cmtice@google.com>
>
>         PR libstdc++/99172
>         * Makefile.in: Regenerate.
>         * acinclude.m4: Add definitions for VTV_CXXFLAGS_LT.
>         * configure: Regenerate.
>         * doc/Makefile.in: Regenerate.
>         * include/Maefile.in: Regenerate.
>         * libsupc++/Makefile.in: Regenerate.
>         * po/Makefile.in: Regenerate.
>         * python/Makefile.in: Regenerate.
>         * src/Makefile.am (AM_CXXFLAGS_LT): New definition.
>         (CXXLINK): Update to use AM_CXXFLAGS_LT instead of AM_CXXFLAGS.
>         * src/Makefile.in: Regenerate.
>         * src/c++11/Makefile.in: Regenerate.
>         * src/c++17/Makefile.in: Regenerate.
>         * src/c++20/Makefile.in: Regenerate.
>         * src/c++98/Makefile.in: Regenerate.
>         * src/filesystem/Makefile.in: Regenerate.
>         * testsuite/Makefile.in: Regenerate.