+2013-04-15 Jack Howarth <howarth@bromo.med.uc.edu>
+
+ Backport from mainline
+
+ 2012-10-10 Jack Howarth <howarth@bromo.med.uc.edu>
+ Jonathan Wakely <jwakely.gcc@gmail.com>
+
+ PR libstdc++/54847
+ * config/os/bsd/darwin/os_defines.h: Define _GLIBCXX_USE_NANOSLEEP
+ and _GLIBCXX_USE_SCHED_YIELD.
+ * acinclude.m4 (GLIBCXX_ENABLE_LIBSTDCXX_TIME): Add comment.
+
2013-04-15 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
* testsuite/30_threads/condition_variable/members/53841.cc: Add
dnl --disable-libstdcxx-time
dnl disables the checks completely
dnl
+dnl N.B. Darwin provides nanosleep but doesn't support the whole POSIX
+dnl Timers option, so doesn't define _POSIX_TIMERS. Because the test
+dnl below fails Darwin unconditionally defines _GLIBCXX_USE_NANOSLEEP in
+dnl os_defines.h and also defines _GLIBCXX_USE_SCHED_YIELD.
+dnl
AC_DEFUN([GLIBCXX_ENABLE_LIBSTDCXX_TIME], [
AC_MSG_CHECKING([for clock_gettime, nanosleep and sched_yield])
// Static initializer macro is buggy in darwin, see libstdc++/51906
#define _GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC
+// Configure checks for nanosleep fail on Darwin, but nanosleep and
+// sched_yield are always available, so use them.
+#define _GLIBCXX_USE_NANOSLEEP 1
+#define _GLIBCXX_USE_SCHED_YIELD 1
+
#endif