[PATCH] LoongArch: Add libstdc++ check-abi support.

[Xi Ruoyao]

On Sat, 2023-11-18 at 08:43 +0000, Jonathan Wakely wrote:
> Hi,
> 
> Libstdc++ patches need to be CC'd to the gcc-patches list as well.
> 
> On Wed, 8 Nov 2023 at 10:26, Peng Fan <fanpeng@loongson.cn> wrote:
> > 
> > libstdc++-v3:
> > 
> >     * configure.host: Add abi_baseline_pair for LoongArch.
> >     * config/abi/post/riscv64-linux-gnu: New directory.
> >     * config/abi/post/riscv64-linux-gnu/baseline_symbols.txt: New file.
> 
> Looks like the wrong filename here.

Try "git gcc-verify ${sha}" (you need to configure the local git repo
with contrib/gcc-git-customization.sh first), it will detect such issues
before submission.

> > Signed-off-by: Peng Fan <fanpeng@loongson.cn>

This should be unneeded because Loongson company should have already
signed a FSF copyright assignment.

/* snip */

> 
> > +TLS:8:_ZSt11__once_call
> > +TLS:8:_ZSt11__once_call@@GLIBCXX_3.4.11
> > +TLS:8:_ZSt15__once_callable
> > +TLS:8:_ZSt15__once_callable@@GLIBCXX_3.4.11
> 
> Does this target support TLS unconditionally? These TLS symbols are
> not included in the baseline symbols for x86_64-pc-linux-gnu, for
> example.

A hardware register is used as TP on this target.  But anyway TLS may be
disabled via --disable-tls, though I don't know it this configuration
really works on loongarch64-linux-gnu (nobody have really tested it, I
guess).

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University