timer: Fix clockid_t undefined on MacOS < 10.12
Related: OS#3722
Change-Id: If466a64bd44dcb8ae8a9b7f82bc9c9435ba3e640
diff --git a/include/osmocom/core/timer_compat.h b/include/osmocom/core/timer_compat.h
index 8fdd0a0..916f568 100644
--- a/include/osmocom/core/timer_compat.h
+++ b/include/osmocom/core/timer_compat.h
@@ -27,6 +27,10 @@
#pragma once
+/* MacOS < 10.12 Sierra does not define clockid_t */
+#if defined(__APPLE__) && (!defined(__DARWIN_C_LEVEL) || __DARWIN_C_LEVEL < 199309L)
+typedef int clockid_t;
+#endif
/* Convenience macros for operations on timevals.
NOTE: `timercmp' does not work for >= or <=. */