Unnamed File

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 9a3930c..cb71b53 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -40,7 +40,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     assert(JA.getType() == types::TY_Plist && "Invalid output type.");
     CmdArgs.push_back("-analyze");
   } else if (isa<PreprocessJobAction>(JA)) {
-    CmdArgs.push_back("-E");
+    if (!Args.hasArg(options::OPT_M))
+      CmdArgs.push_back("-E");
   } else if (isa<PrecompileJobAction>(JA)) {
     // No special option needed, driven by -x.
     //
@@ -228,15 +229,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     // FIXME: Add --stack-protector-buffer-size=<xxx> on
     // -fstack-protect.
 
+    Args.AddLastArg(CmdArgs, options::OPT_M);
     Args.AddLastArg(CmdArgs, options::OPT_MD);
     Args.AddLastArg(CmdArgs, options::OPT_MM);
     Args.AddAllArgs(CmdArgs, options::OPT_MF);
     Args.AddLastArg(CmdArgs, options::OPT_MP);
     Args.AddAllArgs(CmdArgs, options::OPT_MT);
 
-    Arg *Unsupported = Args.getLastArg(options::OPT_M);
-    if (!Unsupported) 
-      Unsupported = Args.getLastArg(options::OPT_MM);
+    Arg *Unsupported = Args.getLastArg(options::OPT_MM);
     if (!Unsupported) 
       Unsupported = Args.getLastArg(options::OPT_MG);
     if (!Unsupported)