[Bug libstdc++/54847] --enable-libstdcxx-time=yes doesn't find the functional nanosleep() on darwin

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54847

--- Comment #34 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-08 16:03:10 UTC ---
(In reply to comment #32)
> Would something simple like...
> 
> Index: acinclude.m4
> ===================================================================
> --- acinclude.m4    (revision 192212)
> +++ acinclude.m4    (working copy)
> @@ -1236,7 +1236,7 @@ AC_DEFUN([GLIBCXX_ENABLE_LIBSTDCXX_TIME]
>      [#include <unistd.h>
>       #include <time.h>
>      ],
> -    [#if _POSIX_TIMERS > 0
> +    [#if (_POSIX_TIMERS > 0 || defined(__APPLE__))
>        timespec tp;
>       #endif
>        clock_gettime(CLOCK_REALTIME, &tp);
> 
> be acceptable? We have the options of __APPLE_CC__, __APPLE__ or __MACH__ from
> the preprocessor defines emitted by FSF gcc trunk on darwin.

You might as well just #define _GLIBCXX_USE_NANOSLEEP in
config/os/bsd/darwin/os_defines.h