1 files changed, 25 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/posix-hrtime.c b/Utilities/cmlibuv/src/unix/posix-hrtime.c
index 323dfc2..a264250 100644
--- a/Utilities/cmlibuv/src/unix/posix-hrtime.c
+++ b/Utilities/cmlibuv/src/unix/posix-hrtime.c
@@ -22,6 +22,29 @@
 #include "uv.h"
 #include "internal.h"
 
+#if defined(__APPLE__)
+/* Special case for CMake bootstrap: no clock_gettime on macOS < 10.12 */
+
+#ifndef CMAKE_BOOTSTRAP
+#error "This code path meant only for use during CMake bootstrap."
+#endif
+
+#include <mach/mach.h>
+#include <mach/mach_time.h>
+
+uint64_t uv__hrtime(uv_clocktype_t type) {
+  static mach_timebase_info_data_t info;
+
+  if ((ACCESS_ONCE(uint32_t, info.numer) == 0 ||
+       ACCESS_ONCE(uint32_t, info.denom) == 0) &&
+      mach_timebase_info(&info) != KERN_SUCCESS)
+    abort();
+
+  return mach_absolute_time() * info.numer / info.denom;
+}
+
+#else
+
 #include <stdint.h>
 #include <time.h>
 
@@ -33,3 +56,5 @@ uint64_t uv__hrtime(uv_clocktype_t type) {
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);
 }
+
+#endif