Re: Patch ping (was Re: [PATCH] libstdc++: Clear padding bits in atomic compare_exchange)

[Iain Sandoe <idsandoe@googlemail.com>]

> On 9 Sep 2022, at 19:36, Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> wrote:
> 

>> Here's a complete patch that combines the various incremental patches
>> that have been going around. I'm testing this now.
>> 
>> Please take a look.
> 
> unfortunately, this patch broke macOS bootstrap (seen on
> x86_64-apple-darwin11.4.2):
> 
> In file included from /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/shared_ptr_atomic.h:33,
>                 from /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/memory:78,
>                 from /vol/gcc/src/hg/master/darwin/libstdc++-v3/include/precompiled/stdc++.h:82:
> /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h: In function 'bool std::__atomic_impl::__compare_exchange(_Tp&, _Val<_Tp>&, _Val<_Tp>&, bool, std::memory_order, std::memory_order)':
> /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h:1008:49: error: expected primary-expression before ',' token
> 1008 |                                           __weak, int(__s), int(__f)))
>      |                                                 ^
> /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h:1017:50: error: expected primary-expression before ',' token
> 1017 |                                            __weak, int(__s), int(__f));
>      |                                                  ^
> 
> Darwin gcc predefines __weak= in gcc/config/darwin-c.cc (darwin_cpp_builtins).

yes, __weak and __strong are Objective C things (in principle, applicable to non-Darwin targets
using NeXT runtime - there is at least one such target).

Iain