1 files changed, 9 insertions, 5 deletions
diff --git a/lib/Tooling/ArgumentsAdjusters.cpp b/lib/Tooling/ArgumentsAdjusters.cpp
index ac9fd3c5cade..7068ec2c4010 100644
--- a/lib/Tooling/ArgumentsAdjusters.cpp
+++ b/lib/Tooling/ArgumentsAdjusters.cpp
@@ -58,14 +58,14 @@ ArgumentsAdjuster getClangStripDependencyFileAdjuster() {
       StringRef Arg = Args[i];
       // All dependency-file options begin with -M. These include -MM,
       // -MF, -MG, -MP, -MT, -MQ, -MD, and -MMD.
-      if (!Arg.startswith("-M"))
+      if (!Arg.startswith("-M")) {
         AdjustedArgs.push_back(Args[i]);
+        continue;
+      }
 
-      if ((Arg == "-MF") || (Arg == "-MT") || (Arg == "-MQ") ||
-          (Arg == "-MD") || (Arg == "-MMD")) {
-        // Output is specified as -MX foo. Skip the next argument also.
+      if (Arg == "-MF" || Arg == "-MT" || Arg == "-MQ")
+        // These flags take an argument: -MX foo. Skip the next argument also.
         ++i;
-      }
     }
     return AdjustedArgs;
   };
@@ -96,6 +96,10 @@ ArgumentsAdjuster getInsertArgumentAdjuster(const char *Extra,
 
 ArgumentsAdjuster combineAdjusters(ArgumentsAdjuster First,
                                    ArgumentsAdjuster Second) {
+  if (!First)
+    return Second;
+  if (!Second)
+    return First;
   return [First, Second](const CommandLineArguments &Args, StringRef File) {
     return Second(First(Args, File), File);
   };