https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63400
--- Comment #2 from frankhb1989 at gmail dot com --- (In reply to Jonathan Wakely from comment #1) > Which of macros are defined on mingw-w64? > > Preprocessing this should tell you > > #include <chrono> > #ifdef _GLIBCXX_USE_CLOCK_REALTIME > #ifdef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL > #warning system_clock using syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp); > #else > #warning system_clock using clock_gettime(CLOCK_REALTIME, &tp); > #endif > #elif defined(_GLIBCXX_USE_GETTIMEOFDAY) > #warning system_clock using gettimeofday(&tv, 0); > #else > #warning system_clock using std::time(0); > #endif > > #ifdef _GLIBCXX_USE_CLOCK_MONOTONIC > #ifdef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL > #warning steady_clock using syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &tp); > #else > #warning steady_clock using clock_gettime(CLOCK_MONOTONIC, &tp); > #endif > #else > #warning steady_clock using > time_point(system_clock::now().time_since_epoch()); > #endif I've looked into c++config.h and I'm sure mingw-w64 4.9.1 distro of msys2 uses clock_gettime defined in winpthreads: /* Defined if clock_gettime syscall has monotonic and realtime clock support. */ /* #undef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL */ /* Defined if clock_gettime has monotonic clock support. */ #define _GLIBCXX_USE_CLOCK_MONOTONIC 1 /* Defined if clock_gettime has realtime clock support. */ #define _GLIBCXX_USE_CLOCK_REALTIME 1 /* Defined if gettimeofday is available. */ #define _GLIBCXX_USE_GETTIMEOFDAY 1 Here is the output (g++ -std=c++11): a.cc:7:2: warning: #warning system_clock using clock_gettime(CLOCK_REALTIME, &tp); [-Wcpp] #warning system_clock using clock_gettime(CLOCK_REALTIME, &tp); ^ a.cc:19:2: warning: #warning steady_clock using clock_gettime(CLOCK_MONOTONIC, &tp); [-Wcpp] #warning steady_clock using clock_gettime(CLOCK_MONOTONIC, &tp); ^
