[Bug sanitizer/68260] false positive with tsan

["pinskia at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68260

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Dmitry Vyukov from comment #1)
> gcc does not instrument atomic operations:
> 
> 00000000004a73d0 <_ZN4spin6unlockEv>:
> 
>         void unlock() { flag.clear(std::memory_order_release); }
>   4a73d0:       55                      push   %rbp
>   4a73d1:       48 89 e5                mov    %rsp,%rbp
>   4a73d4:       48 83 ec 10             sub    $0x10,%rsp
>   4a73d8:       48 8b 45 08             mov    0x8(%rbp),%rax
>   4a73dc:       48 89 7d f0             mov    %rdi,-0x10(%rbp)
>   4a73e0:       48 89 c7                mov    %rax,%rdi
>   4a73e3:       e8 68 4f fd ff          callq  47c350 <__tsan_func_entry>
>   4a73e8:       be 03 00 00 00          mov    $0x3,%esi
>   4a73ed:       48 8b 45 f0             mov    -0x10(%rbp),%rax
>   4a73f1:       48 89 45 f8             mov    %rax,-0x8(%rbp)
>   4a73f5:       48 8b 7d f8             mov    -0x8(%rbp),%rdi
>   4a73f9:       e8 62 02 00 00          callq  4a7660
> <_ZNSt11atomic_flag5clearESt12memory_order>
>   4a73fe:       e8 fd 4f fd ff          callq  47c400 <__tsan_func_exit>
>   4a7403:       48 83 c4 10             add    $0x10,%rsp
>   4a7407:       5d                      pop    %rbp
>   4a7408:       c3                      retq   
> 
> 
> 
> FWIW this programs works fine with clang.


Actually I wonder if _ZNSt11atomic_flag5clearESt12memory_order is instrumented
but the one being chose by the linker is not.  ODR issues :)