cmake HAVE_CLOCK_GETTIME_MONOTONIC examples

fluent/fluent-bit lib/c-ares-1.34.4/CMakeLists.txt :406 

CHECK_SYMBOL_EXISTS (CLOCK_MONOTONIC "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_CLOCK_GETTIME_MONOTONIC)

resiprocate/resiprocate CMakeLists.txt :872 

check_c_source_runs("
   #include <time.h>
   int main() {
      struct timespec ts;
      clock_gettime(CLOCK_MONOTONIC, &ts);
      return 0;
   }" HAVE_CLOCK_GETTIME_MONOTONIC)

resiprocate/resiprocate CMakeLists.txt :881 

add_definitions(-DHAVE_CLOCK_GETTIME_MONOTONIC)