Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.h
@@ -44,6 +44,7 @@
   MACOS_VERSION_HIGH_SIERRA,
   MACOS_VERSION_HIGH_SIERRA_DOT_RELEASE_4,
   MACOS_VERSION_MOJAVE,
+  MACOS_VERSION_CATALINA,
   MACOS_VERSION_UNKNOWN_NEWER
 };
 
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
@@ -558,8 +558,8 @@
       if (minor >= 5)
         return MACOS_VERSION_HIGH_SIERRA_DOT_RELEASE_4;
       return MACOS_VERSION_HIGH_SIERRA;
-    case 18:
-      return MACOS_VERSION_MOJAVE;
+    case 18: return MACOS_VERSION_MOJAVE;
+    case 19: return MACOS_VERSION_CATALINA;
     default:
       if (major < 9) return MACOS_VERSION_UNKNOWN;
       return MACOS_VERSION_UNKNOWN_NEWER;