[patch] libstdc++/61841 odr-use pthread_create in std::thread constructor

[Jakub Jelinek]

On Wed, Aug 13, 2014 at 07:40:57PM +0100, Jonathan Wakely wrote:
> This should fix the Hurd bug in PR61841 as well as the problem
> described in https://gcc.gnu.org/ml/gcc/2013-09/msg00196.html
> 
> Tested x86_64-linux, committed to trunk.
> 
> This is not suitable for the branches as it requires a new exported
> symbol. We could maybe just add some other odr-use of pthread_create,
> but it would probably be optimized away anyway.

E.g. __asm ("" : : "r" (&pthread_create)); would not be optimized away.

> commit 79c721b72b7f9288256cc4bf388cf6b60b65e838
> Author: Jonathan Wakely <jwakely@redhat.com>
> Date:   Fri Jul 18 15:35:49 2014 +0100
> 
>     	PR libstdc++/61841
>     	* include/std/thread (thread::_M_start_thread): Declare new overload.
>     	(thread::thread<_Callable, _Args...>): Call new overload with an
>     	explicit reference to pthread_create.
>     	* src/c++11/thread.cc (thread::_M_start_thread): Add new overload.
>     	* config/abi/pre/gnu.ver: Export new function.

	Jakub