[libstdc++] [testsuite] no libatomic for vxworks

[Jonathan Wakely]

On Mon, 24 Jun 2024 at 21:33, Alexandre Oliva <oliva@adacore.com> wrote:
>
>
> libatomic hasn't been ported to vxworks.  Most of the stdatomic.h and
> <atomic> underlying requirements are provided by builtins and libgcc,
> and the vxworks libc already provides remaining __atomic symbols, so
> porting libatomic doesn't seem to make sense.
>
> However, some of the target arch-only tests in
> add_options_for_libatomic cover vxworks targets, so we end up
> attempting to link libatomic in, even though it's not there.
> Preempt those too-broad tests.
>
> We've long been using a workaround very similar to this on ppc, and now
> that we've made sure there's nothing in libatomic that we'd need on any
> vxworks targets, we're ready to contribute this change.  Regstrapping on
> x86_64-linux-gnu, just to be sure.  Ok to install?

OK, thanks.


>
>
> Co-Authored-By: Marc Poulhiès <poulhies@adacore.com>
>
> for  libstdc++-v3/ChangeLog
>
>         * testsuite/lib/dg-options.exp (add_options_for_libatomic):
>         None for *-*-vxworks*.
> ---
>  libstdc++-v3/testsuite/lib/dg-options.exp |    5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/libstdc++-v3/testsuite/lib/dg-options.exp b/libstdc++-v3/testsuite/lib/dg-options.exp
> index 84f9e3ebc730c..0d77fb029b09b 100644
> --- a/libstdc++-v3/testsuite/lib/dg-options.exp
> +++ b/libstdc++-v3/testsuite/lib/dg-options.exp
> @@ -338,6 +338,11 @@ proc atomic_link_flags { paths } {
>  }
>
>  proc add_options_for_libatomic { flags } {
> +    # We don't (need to) build libatomic for vxworks.  Don't try to
> +    # link it in, even on arches that support libatomic.
> +    if { [istarget *-*-vxworks*] } {
> +       return $flags
> +    }
>      if { [istarget hppa*-*-hpux*]
>          || ([istarget powerpc*-*-*] && [check_effective_target_ilp32])
>          || [istarget riscv*-*-*]
>
> --
> Alexandre Oliva, happy hacker            https://FSFLA.org/blogs/lxo/
>    Free Software Activist                   GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity
> Excluding neuro-others for not behaving ""normal"" is *not* inclusive
>