diff --git a/clang/lib/Tooling/ArgumentsAdjusters.cpp b/clang/lib/Tooling/ArgumentsAdjusters.cpp
--- a/clang/lib/Tooling/ArgumentsAdjusters.cpp
+++ b/clang/lib/Tooling/ArgumentsAdjusters.cpp
@@ -62,7 +62,8 @@
         HasSyntaxOnly = true;
     }
     if (!HasSyntaxOnly)
-      AdjustedArgs.push_back("-fsyntax-only");
+      AdjustedArgs =
+          getInsertArgumentAdjuster("-fsyntax-only")(AdjustedArgs, "");
     return AdjustedArgs;
   };
 }
@@ -137,7 +138,7 @@
 
     CommandLineArguments::iterator I;
     if (Pos == ArgumentInsertPosition::END) {
-      I = Return.end();
+      I = std::find(Return.begin(), Return.end(), "--");
     } else {
       I = Return.begin();
       ++I; // To leave the program name in place
diff --git a/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp b/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
--- a/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
+++ b/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
@@ -177,6 +177,10 @@
                            Opt.matches(OPT__SLASH_Fo))))
         continue;
 
+      // ...including when the inputs are passed after --.
+      if (Opt.matches(OPT__DASH_DASH))
+        break;
+
       // Strip -x, but record the overridden language.
       if (const auto GivenType = tryParseTypeArg(*Arg)) {
         Type = *GivenType;
@@ -235,6 +239,8 @@
           llvm::Twine(ClangCLMode ? "/std:" : "-std=") +
           LangStandard::getLangStandardForKind(Std).getName()).str());
     }
+    if (Filename.startswith("-") || (ClangCLMode && Filename.startswith("/")))
+      Result.CommandLine.push_back("--");
     Result.CommandLine.push_back(std::string(Filename));
     return Result;
   }
diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -440,8 +440,9 @@
       return;
 
   // If there's no override in place add our resource dir.
-  Args.push_back("-resource-dir=" +
-                 CompilerInvocation::GetResourcesPath(Argv0, MainAddr));
+  Args = getInsertArgumentAdjuster(
+      ("-resource-dir=" + CompilerInvocation::GetResourcesPath(Argv0, MainAddr))
+          .c_str())(Args, "");
 }
 
 int ClangTool::run(ToolAction *Action) {
diff --git a/clang/unittests/Tooling/CompilationDatabaseTest.cpp b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
--- a/clang/unittests/Tooling/CompilationDatabaseTest.cpp
+++ b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
@@ -725,14 +725,14 @@
 protected:
   // Look up the command from a relative path, and return it in string form.
   // The input file is not included in the returned command.
-  std::string getCommand(llvm::StringRef F) {
+  std::string getCommand(llvm::StringRef F, bool MakeNative = true) {
     auto Results =
         inferMissingCompileCommands(std::make_unique<MemCDB>(Entries))
-            ->getCompileCommands(path(F));
+            ->getCompileCommands(MakeNative ? path(F) : F);
     if (Results.empty())
       return "none";
     // drop the input file argument, so tests don't have to deal with path().
-    EXPECT_EQ(Results[0].CommandLine.back(), path(F))
+    EXPECT_EQ(Results[0].CommandLine.back(), MakeNative ? path(F) : F)
         << "Last arg should be the file";
     Results[0].CommandLine.pop_back();
     return llvm::join(Results[0].CommandLine, " ");
@@ -812,6 +812,28 @@
   EXPECT_EQ(getCommand("dir/bar.cpp"), "clang -D dir/foo.cpp -Wall");
 }
 
+TEST_F(InterpolateTest, StripDoubleDash) {
+  add("dir/foo.cpp", "-o foo.o -std=c++14 -Wall -- dir/foo.cpp");
+  // input file and output option are removed
+  // -Wall flag isn't
+  // -std option gets re-added as the last argument before the input file
+  // -- is removed as it's not necessary - the new input file doesn't start with
+  // a dash
+  EXPECT_EQ(getCommand("dir/bar.cpp"), "clang -D dir/foo.cpp -Wall -std=c++14");
+}
+
+TEST_F(InterpolateTest, InsertDoubleDash) {
+  add("dir/foo.cpp", "-o foo.o -std=c++14 -Wall");
+  EXPECT_EQ(getCommand("-dir/bar.cpp", false),
+            "clang -D dir/foo.cpp -Wall -std=c++14 --");
+}
+
+TEST_F(InterpolateTest, InsertDoubleDashForClangCL) {
+  add("dir/foo.cpp", "clang-cl", "/std:c++14 /W4");
+  EXPECT_EQ(getCommand("/dir/bar.cpp", false),
+            "clang-cl -D dir/foo.cpp /W4 /std:c++14 --");
+}
+
 TEST_F(InterpolateTest, Case) {
   add("FOO/BAR/BAZ/SHOUT.cc");
   add("foo/bar/baz/quiet.cc");
@@ -831,7 +853,7 @@
   add("foo.cpp", "clang-cl", "/W4");
 
   // Language flags should be added with CL syntax.
-  EXPECT_EQ(getCommand("foo.h"), "clang-cl -D foo.cpp /W4 /TP");
+  EXPECT_EQ(getCommand("foo.h", false), "clang-cl -D foo.cpp /W4 /TP");
 }
 
 TEST_F(InterpolateTest, DriverModes) {
@@ -839,8 +861,10 @@
   add("bar.cpp", "clang", "--driver-mode=cl");
 
   // --driver-mode overrides should be respected.
-  EXPECT_EQ(getCommand("foo.h"), "clang-cl -D foo.cpp --driver-mode=gcc -x c++-header");
-  EXPECT_EQ(getCommand("bar.h"), "clang -D bar.cpp --driver-mode=cl /TP");
+  EXPECT_EQ(getCommand("foo.h"),
+            "clang-cl -D foo.cpp --driver-mode=gcc -x c++-header");
+  EXPECT_EQ(getCommand("bar.h", false),
+            "clang -D bar.cpp --driver-mode=cl /TP");
 }
 
 TEST(TransferCompileCommandTest, Smoke) {