[PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Wakely]

On Wed, 1 Sept 2021 at 02:44, Jonathan Yong <10walls@gmail.com> wrote:
>
> On 8/31/21 9:02 AM, Jonathan Wakely wrote:
> > It looks like my questions about this patch never got an answer, and
> > it never got applied.
> >
> > Could somebody say whether TLS is enabled for native *-*-mingw*
> > builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
> > cross-compiler config too.
> >
> > For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not enabled:
> >
> > /* Define to 1 if the target supports thread-local storage. */
> > /* #undef _GLIBCXX_HAVE_TLS */
> >
> >
> >
> >
> > On Mon, 19 Feb 2018 at 08:59, Hugo Beauzée-Luyssen <hugo@beauzee.fr> wrote:
> >>
> >> libstdc++-v3: Check for TLS support on mingw
> >>
> >> 2018-02-16  Hugo Beauzée-Luyssen  <hugo@beauzee.fr>
> >>
> >>      * crossconfig.m4: Check for TLS support on mignw
> >>      * configure: regenerate
> >>
> >> Index: libstdc++-v3/crossconfig.m4
> >> ===================================================================
> >> --- libstdc++-v3/crossconfig.m4 (revision 257730)
> >> +++ libstdc++-v3/crossconfig.m4 (working copy)
> >> @@ -197,6 +197,7 @@ case "${host}" in
> >>       GLIBCXX_CHECK_LINKER_FEATURES
> >>       GLIBCXX_CHECK_MATH_SUPPORT
> >>       GLIBCXX_CHECK_STDLIB_SUPPORT
> >> +    GCC_CHECK_TLS
> >>       ;;
> >>     *-netbsd*)
> >>       SECTION_FLAGS='-ffunction-sections -fdata-sections'
>
> According to MSYS2 native from
> https://mirror.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-10.3.0-5-any.pkg.tar.zst:
>
> x86_64-w64-mingw32/bits/c++config.h:#define _GLIBCXX_HAVE_TLS 1
>
> So yes.

Thanks! I'll test the patch on a cross-compiler and apply it soon then.

(Thanks also to LH for the answer)