diff --git a/compiler-rt/lib/asan/asan_mac.cc b/compiler-rt/lib/asan/asan_mac.cc
index 0d5d25c5afd4..d4042d2849cb 100644
--- a/compiler-rt/lib/asan/asan_mac.cc
+++ b/compiler-rt/lib/asan/asan_mac.cc
@@ -27,6 +27,7 @@
 #include <mach-o/loader.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
+#include <sys/sysctl.h>
 #include <sys/ucontext.h>
 #include <pthread.h>
 #include <fcntl.h>
@@ -58,6 +59,28 @@ void GetPcSpBp(void *context, uintptr_t *pc, uintptr_t *sp, uintptr_t *bp) {
 # endif  // __WORDSIZE
 }
 
+int GetMacosVersion() {
+  int mib[2] = { CTL_KERN, KERN_OSRELEASE };
+  char version[100];
+  size_t len = 0, maxlen = sizeof(version) / sizeof(version[0]);
+  for (int i = 0; i < maxlen; i++) version[i] = '\0';
+  // Get the version length.
+  CHECK(sysctl(mib, 2, NULL, &len, NULL, 0) != -1);
+  CHECK(len < maxlen);
+  CHECK(sysctl(mib, 2, version, &len, NULL, 0) != -1);
+  switch (version[0]) {
+    case '9': return MACOS_VERSION_LEOPARD;
+    case '1': {
+      switch (version[1]) {
+        case '0': return MACOS_VERSION_SNOW_LEOPARD;
+        case '1': return MACOS_VERSION_LION;
+        default: return MACOS_VERSION_UNKNOWN;
+      }
+    }
+    default: return MACOS_VERSION_UNKNOWN;
+  }
+}
+
 // No-op. Mac does not support static linkage anyway.
 void *AsanDoesNotSupportStaticLinkage() {
   return NULL;
diff --git a/compiler-rt/lib/asan/asan_mac.h b/compiler-rt/lib/asan/asan_mac.h
index bb39f8206b4b..e0ac5f6b7dd2 100644
--- a/compiler-rt/lib/asan/asan_mac.h
+++ b/compiler-rt/lib/asan/asan_mac.h
@@ -24,6 +24,17 @@
 #include <setjmp.h>
 #include <CoreFoundation/CFString.h>
 
+enum {
+  MACOS_VERSION_UNKNOWN = 0,
+  MACOS_VERSION_LEOPARD,
+  MACOS_VERSION_SNOW_LEOPARD,
+  MACOS_VERSION_LION,
+};
+
+namespace __asan {
+int GetMacosVersion();
+}
+
 typedef void* pthread_workqueue_t;
 typedef void* pthread_workitem_handle_t;