GHC HEAD breakage by pthread_setname_np usage.

[Simon Marlow]

Thanks for letting me know, I'll add a configure test to check for this.

Cheers,
Simon

On 13/10/2014 10:12, Karel Gardas wrote:
>
> Hello Simon,
>
> I'm sorry to disturb you, but your recent patch:
>
> commit 674c631ea111233daa929ef63500d75ba0db8858
> Author: Simon Marlow <marlowsd at gmail.com>
> Date:   Fri Oct 10 14:26:19 2014 +0100
>
>      Name worker threads using pthread_setname_np
>
>      This helps identify threads in gdb particularly in processes with a
>      lot of threads.
>
>
>
> breaks build on FreeBSD and Solaris at least. The problem is that
> pthread_setname_np is GNU extension and so far I've seen it just in
> linux using glibc >=2.12, modern NetBSD and modern QNX. Builds on
> Solaris and FreeBSD result in unresolved symbol failure. Two examples
> showing this are here:
>
> http://haskell.inf.elte.hu/builders/smartos-x86-head/147/10.html
> http://haskell.inf.elte.hu/builders/freebsd-amd64-head/411/10.html
>
> The problem is that I cannot simply #ifdef usage of this since it's
> using `name' parameter of the createOSThread function and if I #ifdef
> this, then the compiler emits obvious warning:
>
> rts/posix/OSThreads.c: In function ‘createOSThread’:
>
> rts/posix/OSThreads.c:132:40:  warning: unused parameter ‘name’
>
>
> which is probably going to break validate build which builds with -Werror.
>
> Perhaps if pthread_setname_np is not available on the target platform we
> can define it ourself (as empty macro or inline function doing nothing?)
> and use that, but in this case we would probably need proper configure
> check for the presence of this function.
>
> As rts is your domain, I'm just writing this in a hope that you will
> either revert the patch for now or solve it in a way you like.
>
> Thanks!
> Karel