Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -245,6 +245,24 @@
     -stdlib=libc++
     -lc++
     -lc++abi)
+
+  set(DARWIN_WEAK_SYMBOLS
+      ___asan_default_options
+      ___asan_default_suppressions
+      ___asan_on_error
+      ___lsan_default_suppressions
+      ___lsan_is_turned_off
+      ___sanitizer_free_hook
+      ___sanitizer_malloc_hook
+      ___sanitizer_symbolize_code
+      ___sanitizer_symbolize_data
+      ___sanitizer_symbolize_demangle
+      ___sanitizer_symbolize_flush
+      ___ubsan_default_options)
+
+  foreach(SYMBOL ${DARWIN_WEAK_SYMBOLS})
+    set(DARWIN_COMMON_LINKFLAGS ${DARWIN_COMMON_LINKFLAGS} -Wl,-U,${SYMBOL})
+  endforeach()
   
   check_linker_flag("-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
   if(COMPILER_RT_HAS_APP_EXTENSION)