Index: docs/ClangCommandLineReference.rst
===================================================================
--- docs/ClangCommandLineReference.rst
+++ docs/ClangCommandLineReference.rst
@@ -1130,6 +1130,10 @@
 
 Use NMake/Jom format for the depfile
 
+.. option:: -MD-filter=prefix
+
+Specify prefix string for dependencies which should be omitted from depfile
+
 Dumping preprocessor state
 --------------------------
 
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -368,6 +368,8 @@
     HelpText<"Like -MD, but also implies -E and writes to stdout by default">;
 def MM : Flag<["-"], "MM">, Group<M_Group>,
     HelpText<"Like -MMD, but also implies -E and writes to stdout by default">;
+def MD_filter : Joined<["-"], "MD-filter=">, Group<M_Group>,
+    HelpText<"Filter depfile output prefixed with string from -MMD, -MD, -MM, or -M">;
 def MF : JoinedOrSeparate<["-"], "MF">, Group<M_Group>,
     HelpText<"Write depfile output from -MMD, -MD, -MM, or -M to <file>">,
     MetaVarName<"<file>">;
@@ -609,6 +611,8 @@
   HelpText<"Filename to write DOT-formatted header dependencies to">;
 def module_dependency_dir : Separate<["-"], "module-dependency-dir">,
   Flags<[CC1Option]>, HelpText<"Directory to dump module dependencies to">;
+def dependency_filter : Separate<["-"], "dependency-filter">, Flags<[CC1Option]>,
+  HelpText<"Filter dependencies with prefix from the dependency output.">;
 def dumpmachine : Flag<["-"], "dumpmachine">;
 def dumpspecs : Flag<["-"], "dumpspecs">, Flags<[Unsupported]>;
 def dumpversion : Flag<["-"], "dumpversion">;
Index: include/clang/Frontend/DependencyOutputOptions.h
===================================================================
--- include/clang/Frontend/DependencyOutputOptions.h
+++ include/clang/Frontend/DependencyOutputOptions.h
@@ -41,6 +41,10 @@
   /// The file to write dependency output to.
   std::string OutputFile;
 
+  /// Dependency output which is prefixed with this string is filtered
+  /// from the dependency output.
+  std::string DependencyFilter;
+
   /// The file to write header include output to. This is orthogonal to
   /// ShowHeaderIncludes (-H) and will include headers mentioned in the
   /// predefines buffer. If the output file is "-", output will be sent to
Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -1118,6 +1118,11 @@
       CmdArgs.push_back("-module-file-deps");
   }
 
+  if (Arg *MD_Filter = Args.getLastArg(options::OPT_MD_filter)) {
+    CmdArgs.push_back("-dependency-filter");
+    CmdArgs.push_back(MD_Filter->getValue());
+  }
+
   if (Args.hasArg(options::OPT_MG)) {
     if (!A || A->getOption().matches(options::OPT_MD) ||
         A->getOption().matches(options::OPT_MMD))
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -1340,6 +1340,7 @@
 static void ParseDependencyOutputArgs(DependencyOutputOptions &Opts,
                                       ArgList &Args) {
   Opts.OutputFile = Args.getLastArgValue(OPT_dependency_file);
+  Opts.DependencyFilter = Args.getLastArgValue(OPT_dependency_filter);
   Opts.Targets = Args.getAllArgValues(OPT_MT);
   Opts.IncludeSystemHeaders = Args.hasArg(OPT_sys_header_deps);
   Opts.IncludeModuleFiles = Args.hasArg(OPT_module_file_deps);
Index: lib/Frontend/DependencyFile.cpp
===================================================================
--- lib/Frontend/DependencyFile.cpp
+++ lib/Frontend/DependencyFile.cpp
@@ -154,6 +154,7 @@
   llvm::StringSet<> FilesSet;
   const Preprocessor *PP;
   std::string OutputFile;
+  std::string DependencyFilter;
   std::vector<std::string> Targets;
   bool IncludeSystemHeaders;
   bool PhonyTarget;
@@ -170,7 +171,8 @@
 
 public:
   DFGImpl(const Preprocessor *_PP, const DependencyOutputOptions &Opts)
-    : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
+    : PP(_PP), OutputFile(Opts.OutputFile),
+      DependencyFilter(Opts.DependencyFilter), Targets(Opts.Targets),
       IncludeSystemHeaders(Opts.IncludeSystemHeaders),
       PhonyTarget(Opts.UsePhonyTargets),
       AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
@@ -273,6 +275,12 @@
   if (isSpecialFilename(Filename))
     return false;
 
+  if (DependencyFilter.size() &&
+      DependencyFilter.compare(0, DependencyFilter.size(), Filename,
+                               DependencyFilter.size()) == 0)
+    // Remove dependencies that are prefixed by the Filter string.
+    return false;
+
   if (IncludeSystemHeaders)
     return true;
 
Index: test/Frontend/dependency-gen.c
===================================================================
--- test/Frontend/dependency-gen.c
+++ test/Frontend/dependency-gen.c
@@ -5,6 +5,11 @@
 // RUN: cd %t.dir
 // RUN: %clang -MD -MF - %s -fsyntax-only -I a/b | FileCheck -check-prefix=CHECK-ONE %s
 // CHECK-ONE: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
+// RUN: %clang -MD -MF - %s -fsyntax-only -I a/b -MD-filter="a/b" | FileCheck -check-prefix=CHECK-FILTER %s
+// CHECK-FILTER-NOT: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
+// RUN: %clang -MD -MF - %s -fsyntax-only -I a/b -MD-filter="a/b" | FileCheck -check-prefix=CHECK-WS %s
+// RUN: %clang -MD -MF - %s -fsyntax-only -I a/b -MD-filter="fail" | FileCheck -check-prefix=CHECK-ONE %s
+// CHECK-WS: {{^ *$}}
 
 // PR8974 (-include flag)
 // RUN: %clang -MD -MF - %s -fsyntax-only -include a/b/x.h -DINCLUDE_FLAG_TEST | FileCheck -check-prefix=CHECK-TWO %s