http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59369
--- Comment #1 from Jack Howarth <howarth at nitro dot med.uc.edu> --- From http://stackoverflow.com/questions/5167269/clock-gettime-alternative-in-mac-os-x, the following code would work on darwin, but I'm not sure if the test is still valid... /* { dg-do run } */ #ifdef __MACH__ #define CLOCK_MONOTONIC 0 #include <sys/time.h> static int weak_gettime (int clk_id, struct timespec *tp) __attribute__((__weakref__("clock_gettime"))); int clock_gettime(int clk_id, struct timespec* tp) { struct timeval now; int rv = gettimeofday(&now, NULL); if (rv) return rv; tp->tv_sec = now.tv_sec; tp->tv_nsec = now.tv_usec * 1000; return 0; } #else #include <time.h> static int weak_gettime (clockid_t clk_id, struct timespec *tp) __attribute__((__weakref__("clock_gettime"))); #endif int main() { if (!clock_gettime) return 0; struct timespec ts; return weak_gettime(CLOCK_MONOTONIC, &ts); }