# HG changeset patch
# Parent 5a47a5ded615a8757277869e03afe2337e6de3d4
Guard against undefined weak symbols before Mac OS X 10.9 (PR sanitizer/82825)
@@ -63,7 +63,13 @@
// SANITIZER_SUPPORTS_WEAK_HOOKS means that we support real weak functions that
// will evaluate to a null pointer when not defined.
#ifndef SANITIZER_SUPPORTS_WEAK_HOOKS
-#if (SANITIZER_LINUX || SANITIZER_MAC) && !SANITIZER_GO
+#if SANITIZER_LINUX && !SANITIZER_GO
+# define SANITIZER_SUPPORTS_WEAK_HOOKS 1
+// Before Xcode 4.5, the Darwin linker doesn't reliably support undefined
+// weak symbols. Mac OS X 10.9/Darwin 13 is the first release only supported
+// by Xcode >= 4.5.
+#elif SANITIZER_MAC && \
+ __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1090 && !SANITIZER_GO
# define SANITIZER_SUPPORTS_WEAK_HOOKS 1
#else
# define SANITIZER_SUPPORTS_WEAK_HOOKS 0