Index: lib/Driver/WindowsToolChain.cpp
===================================================================
--- lib/Driver/WindowsToolChain.cpp
+++ lib/Driver/WindowsToolChain.cpp
@@ -196,6 +196,9 @@
                                            sizeof(windowsSDKInstallDir) - 1);
     // If we have both vc80 and vc90, pick version we were compiled with.
   if (hasSDKDir && windowsSDKInstallDir[0]) {
+    char *p = windowsSDKInstallDir + strlen(windowsSDKInstallDir) - 1;
+    if (*p == '\\')
+      *p = '\0';
     path = windowsSDKInstallDir;
     return true;
   }