Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -7820,7 +7820,10 @@
     CmdArgs.push_back(Args.MakeArgString("-debug"));
     CmdArgs.push_back(Args.MakeArgString("-incremental:no"));
     // FIXME: Handle 64-bit.
-    if (DLL) {
+    if (Args.hasArg(options::OPT__SLASH_MD, options::OPT__SLASH_MDd)) {
+      addSanitizerRTWindows(getToolChain(), Args, CmdArgs, "asan_dynamic-i386");
+      addSanitizerRTWindows(getToolChain(), Args, CmdArgs, "asan_uar_thunk-i386");
+    } else if (DLL) {
       addSanitizerRTWindows(getToolChain(), Args, CmdArgs,
                             "asan_dll_thunk-i386");
     } else {
Index: cfe/trunk/test/Driver/cl-link.c
===================================================================
--- cfe/trunk/test/Driver/cl-link.c
+++ cfe/trunk/test/Driver/cl-link.c
@@ -19,6 +19,14 @@
 // ASAN: "{{.*}}clang_rt.asan_cxx-i386.lib"
 // ASAN: "{{.*}}cl-link{{.*}}.obj"
 
+// RUN: %clang_cl /MD /Tc%s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN-MD %s
+// ASAN-MD: link.exe
+// ASAN-MD: "-debug"
+// ASAN-MD: "-incremental:no"
+// ASAN-MD: "{{.*}}clang_rt.asan_dynamic-i386.lib"
+// ASAN-MD: "{{.*}}clang_rt.asan_uar_thunk-i386.lib"
+// ASAN-MD: "{{.*}}cl-link{{.*}}.obj"
+
 // RUN: %clang_cl /LD -### /Tc%s 2>&1 | FileCheck --check-prefix=DLL %s
 // RUN: %clang_cl /LDd -### /Tc%s 2>&1 | FileCheck --check-prefix=DLL %s
 // DLL: link.exe
Index: compiler-rt/trunk/lib/asan/CMakeLists.txt
===================================================================
--- compiler-rt/trunk/lib/asan/CMakeLists.txt
+++ compiler-rt/trunk/lib/asan/CMakeLists.txt
@@ -187,6 +187,11 @@
         CFLAGS ${ASAN_CFLAGS} -DASAN_DLL_THUNK
         DEFS ${ASAN_COMMON_DEFINITIONS})
       add_dependencies(asan clang_rt.asan_dll_thunk-${arch})
+      add_compiler_rt_runtime(clang_rt.asan_uar_thunk-${arch} ${arch} STATIC
+        SOURCES asan_uar_thunk.cc
+        CFLAGS ${ASAN_CFLAGS} -DASAN_UAR_THUNK
+        DEFS ${ASAN_COMMON_DEFINITIONS})
+      add_dependencies(asan clang_rt.asan_uar_thunk-${arch})
     endif()
   endforeach()
 endif()
Index: compiler-rt/trunk/lib/asan/asan_uar_thunk.cc
===================================================================
--- compiler-rt/trunk/lib/asan/asan_uar_thunk.cc
+++ compiler-rt/trunk/lib/asan/asan_uar_thunk.cc
@@ -0,0 +1,30 @@
+//===-- asan_uar_thunk.cc -------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// This file defines a copy of __asan_option_detect_stack_use_after_return that
+// should be used when linking an MD runtime with a set of object files.
+//
+// An MD runtime dllexports this variable, so normally we would dllimport it in
+// each TU.  Unfortunately, in general we don't know if a given TU is going to
+// be used with a MT or MD runtime.
+//===----------------------------------------------------------------------===//
+
+// Only compile this code when buidling asan_uar_thunk.lib
+// Using #ifdef rather than relying on Makefiles etc.
+// simplifies the build procedure.
+#ifdef ASAN_UAR_THUNK
+extern "C" {
+__declspec(dllimport) int __asan_should_detect_stack_use_after_return();
+
+int __asan_option_detect_stack_use_after_return =
+    __asan_should_detect_stack_use_after_return();
+}
+#endif // ASAN_DLL_THUNK