Index: include/clang/Tooling/ArgumentsAdjusters.h
===================================================================
--- include/clang/Tooling/ArgumentsAdjusters.h
+++ include/clang/Tooling/ArgumentsAdjusters.h
@@ -40,8 +40,7 @@
   ///
   /// \returns Modified sequence of command line arguments.
   virtual CommandLineArguments Adjust(const CommandLineArguments &Args) = 0;
-  virtual ~ArgumentsAdjuster() {
-  }
+  virtual ~ArgumentsAdjuster() {}
 };
 
 /// \brief Syntax check only command line adjuster.
@@ -58,6 +57,22 @@
   CommandLineArguments Adjust(const CommandLineArguments &Args) override;
 };
 
+class InsertArgumentAdjuster : public ArgumentsAdjuster {
+public:
+  enum Position { BEGIN, END };
+
+  InsertArgumentAdjuster(const CommandLineArguments &Extra, Position Pos)
+      : Extra(Extra), Pos(Pos) {}
+
+  InsertArgumentAdjuster(const char *Extra, Position Pos)
+      : Extra(1, std::string(Extra)), Pos(Pos) {}
+
+  CommandLineArguments Adjust(const CommandLineArguments &Args) override;
+
+private:
+  const CommandLineArguments Extra;
+  const Position Pos;
+};
 } // end namespace tooling
 } // end namespace clang
 
Index: include/clang/Tooling/CommonOptionsParser.h
===================================================================
--- include/clang/Tooling/CommonOptionsParser.h
+++ include/clang/Tooling/CommonOptionsParser.h
@@ -89,6 +89,8 @@
 private:
   std::unique_ptr<CompilationDatabase> Compilations;
   std::vector<std::string> SourcePathList;
+  std::vector<std::string> ExtraArgsBefore;
+  std::vector<std::string> ExtraArgsAfter;
 };
 
 }  // namespace tooling
Index: lib/Tooling/ArgumentsAdjusters.cpp
===================================================================
--- lib/Tooling/ArgumentsAdjusters.cpp
+++ lib/Tooling/ArgumentsAdjusters.cpp
@@ -54,6 +54,22 @@
   return AdjustedArgs;
 }
 
+CommandLineArguments
+InsertArgumentAdjuster::Adjust(const CommandLineArguments &Args) {
+  CommandLineArguments Return(Args);
+
+  CommandLineArguments::iterator I;
+  if (Pos == END) {
+    I = Return.end();
+  } else {
+    I = Return.begin();
+    ++I; // To leave the program name in place
+  }
+
+  Return.insert(I, Extra.begin(), Extra.end());
+  return Return;
+}
+
 } // end namespace tooling
 } // end namespace clang
 
Index: lib/Tooling/CommonOptionsParser.cpp
===================================================================
--- lib/Tooling/CommonOptionsParser.cpp
+++ lib/Tooling/CommonOptionsParser.cpp
@@ -25,6 +25,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/CommandLine.h"
+#include "clang/Tooling/ArgumentsAdjusters.h"
 #include "clang/Tooling/CommonOptionsParser.h"
 #include "clang/Tooling/Tooling.h"
 
@@ -53,6 +54,42 @@
     "\tsuffix of a path in the compile command database.\n"
     "\n";
 
+class ArgumentsAdjustingCompilations : public CompilationDatabase {
+public:
+  ArgumentsAdjustingCompilations(
+      std::unique_ptr<CompilationDatabase> Compilations)
+      : Compilations(std::move(Compilations)) {}
+
+  void appendArgumentsAdjuster(std::unique_ptr<ArgumentsAdjuster> Adjuster) {
+    Adjusters.push_back(std::move(Adjuster));
+  }
+
+  std::vector<CompileCommand>
+  getCompileCommands(StringRef FilePath) const override {
+    return adjustCommands(Compilations->getCompileCommands(FilePath));
+  }
+
+  std::vector<std::string> getAllFiles() const override {
+    return Compilations->getAllFiles();
+  }
+
+  std::vector<CompileCommand> getAllCompileCommands() const override {
+    return adjustCommands(Compilations->getAllCompileCommands());
+  }
+
+private:
+  std::unique_ptr<CompilationDatabase> Compilations;
+  std::vector<std::unique_ptr<ArgumentsAdjuster>> Adjusters;
+
+  std::vector<CompileCommand>
+  adjustCommands(std::vector<CompileCommand> Commands) const {
+    for (CompileCommand &Command : Commands)
+      for (const auto &Adjuster : Adjusters)
+        Command.CommandLine = Adjuster->Adjust(Command.CommandLine);
+    return Commands;
+  }
+};
+
 CommonOptionsParser::CommonOptionsParser(int &argc, const char **argv,
                                          cl::OptionCategory &Category,
                                          const char *Overview) {
@@ -65,6 +102,16 @@
       cl::Positional, cl::desc("<source0> [... <sourceN>]"), cl::OneOrMore,
       cl::cat(Category));
 
+  static cl::list<std::string> ArgsAfter(
+      "extra-arg",
+      cl::desc("Additional argument to append to the compiler command line"),
+      cl::cat(Category));
+
+  static cl::list<std::string> ArgsBefore(
+      "extra-arg-before",
+      cl::desc("Additional argument to prepend to the compiler command line"),
+      cl::cat(Category));
+
   // Hide unrelated options.
   StringMap<cl::Option*> Options;
   cl::getRegisteredOptions(Options);
@@ -91,4 +138,14 @@
     if (!Compilations)
       llvm::report_fatal_error(ErrorMessage);
   }
+  auto AdjustingCompilations =
+      llvm::make_unique<ArgumentsAdjustingCompilations>(
+          std::move(Compilations));
+  AdjustingCompilations->appendArgumentsAdjuster(
+      llvm::make_unique<InsertArgumentAdjuster>(ArgsBefore,
+                                                InsertArgumentAdjuster::BEGIN));
+  AdjustingCompilations->appendArgumentsAdjuster(
+      llvm::make_unique<InsertArgumentAdjuster>(ArgsAfter,
+                                                InsertArgumentAdjuster::END));
+  Compilations = std::move(AdjustingCompilations);
 }
Index: tools/clang-check/ClangCheck.cpp
===================================================================
--- tools/clang-check/ClangCheck.cpp
+++ tools/clang-check/ClangCheck.cpp
@@ -78,15 +78,6 @@
     cl::desc(Options->getOptionHelpText(options::OPT_fix_what_you_can)),
     cl::cat(ClangCheckCategory));
 
-static cl::list<std::string> ArgsAfter(
-    "extra-arg",
-    cl::desc("Additional argument to append to the compiler command line"),
-    cl::cat(ClangCheckCategory));
-static cl::list<std::string> ArgsBefore(
-    "extra-arg-before",
-    cl::desc("Additional argument to prepend to the compiler command line"),
-    cl::cat(ClangCheckCategory));
-
 namespace {
 
 // FIXME: Move FixItRewriteInPlace from lib/Rewrite/Frontend/FrontendActions.cpp
@@ -140,58 +131,21 @@
   }
 };
 
-class InsertAdjuster: public clang::tooling::ArgumentsAdjuster {
-public:
-  enum Position { BEGIN, END };
-
-  InsertAdjuster(const CommandLineArguments &Extra, Position Pos)
-    : Extra(Extra), Pos(Pos) {
-  }
-
-  InsertAdjuster(const char *Extra, Position Pos)
-    : Extra(1, std::string(Extra)), Pos(Pos) {
-  }
-
-  virtual CommandLineArguments
-  Adjust(const CommandLineArguments &Args) override {
-    CommandLineArguments Return(Args);
-
-    CommandLineArguments::iterator I;
-    if (Pos == END) {
-      I = Return.end();
-    } else {
-      I = Return.begin();
-      ++I; // To leave the program name in place
-    }
-
-    Return.insert(I, Extra.begin(), Extra.end());
-    return Return;
-  }
-
-private:
-  const CommandLineArguments Extra;
-  const Position Pos;
-};
-
-} // namespace
-
-// Anonymous namespace here causes problems with gcc <= 4.4 on MacOS 10.6.
-// "Non-global symbol: ... can't be a weak_definition"
-namespace clang_check {
 class ClangCheckActionFactory {
 public:
   std::unique_ptr<clang::ASTConsumer> newASTConsumer() {
     if (ASTList)
       return clang::CreateASTDeclNodeLister();
     if (ASTDump)
-      return clang::CreateASTDumper(ASTDumpFilter, /*DumpDecls*/ true,
-                                    /*DumpLookups*/ false);
+      return clang::CreateASTDumper(ASTDumpFilter, /*DumpDecls=*/true,
+                                    /*DumpLookups=*/false);
     if (ASTPrint)
       return clang::CreateASTPrinter(&llvm::outs(), ASTDumpFilter);
     return llvm::make_unique<clang::ASTConsumer>();
   }
 };
-}
+
+} // namespace
 
 int main(int argc, const char **argv) {
   llvm::sys::PrintStackTraceOnErrorSignal();
@@ -202,21 +156,13 @@
   // Clear adjusters because -fsyntax-only is inserted by the default chain.
   Tool.clearArgumentsAdjusters();
   Tool.appendArgumentsAdjuster(new ClangStripOutputAdjuster());
-  if (ArgsAfter.size() > 0) {
-    Tool.appendArgumentsAdjuster(new InsertAdjuster(ArgsAfter,
-          InsertAdjuster::END));
-  }
-  if (ArgsBefore.size() > 0) {
-    Tool.appendArgumentsAdjuster(new InsertAdjuster(ArgsBefore,
-          InsertAdjuster::BEGIN));
-  }
 
   // Running the analyzer requires --analyze. Other modes can work with the
   // -fsyntax-only option.
-  Tool.appendArgumentsAdjuster(new InsertAdjuster(
-        Analyze ? "--analyze" : "-fsyntax-only", InsertAdjuster::BEGIN));
+  Tool.appendArgumentsAdjuster(new InsertArgumentAdjuster(
+      Analyze ? "--analyze" : "-fsyntax-only", InsertArgumentAdjuster::BEGIN));
 
-  clang_check::ClangCheckActionFactory CheckFactory;
+  ClangCheckActionFactory CheckFactory;
   std::unique_ptr<FrontendActionFactory> FrontendFactory;
 
   // Choose the correct factory based on the selected mode.