Since Mac OS X doesn't support clock_gettime, implement it if running on Mac.

src/cpp-utils/system/clock_gettime.h

@@ -0,0 +1,24 @@
+#pragma once
+#ifndef MESSMER_CPPUTILS_SYSTEM_CLOCKGETTIME_H
+#define MESSMER_CPPUTILS_SYSTEM_CLOCKGETTIME_H
+
+// Implements clock_gettime for Mac OS X (where it is not implemented by in the standard library)
+// Source: http://stackoverflow.com/a/9781275/829568
+// Caution: The returned value is less precise than the returned value from a linux clock_gettime would be.
+
+#ifdef __MACH__
+#include <sys/time.h>
+#define CLOCK_REALTIME 0
+int clock_gettime(int /*clk_id*/, struct timespec *result) {
+    struct timeval now;
+    int rv = gettimeofday(&now, nullptr);
+    if (rv) {
+        return rv;
+    }
+    result->tv_sec = now.tv_sec;
+    result->tv_nsec = now.tv_sec * 1000;
+    return 0;
+}
+#endif
+
+#endif

src/cryfs/filesystem/fsblobstore/utils/DirEntryList.cpp

@@ -1,5 +1,6 @@
 #include "DirEntryList.h"
 #include <limits>
+#include <cpp-utils/system/clock_gettime.h>
 
 //TODO Get rid of that in favor of better error handling
 #include <fspp/fuse/FuseErrnoException.h>