Index: ../tools/clang/lib/Driver/ToolChains.cpp
===================================================================
--- ../tools/clang/lib/Driver/ToolChains.cpp	(revision 166410)
+++ ../tools/clang/lib/Driver/ToolChains.cpp	(working copy)
@@ -366,8 +366,7 @@
     if (Args.hasArg(options::OPT_dynamiclib) ||
         Args.hasArg(options::OPT_bundle)) return;
     if (isTargetIPhoneOS()) {
-      getDriver().Diag(diag::err_drv_clang_unsupported_per_platform)
-        << "-faddress-sanitizer";
+      AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.asan_osx_dynamic.dylib");
     } else {
       AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.asan_osx.a");