diff --git a/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/lib/FrontendTool/ExecuteCompilerInvocation.cpp
new file mode 100644
index 0000000..63c6287
--- /dev/null
+++ b/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -0,0 +1,155 @@
+//===--- ExecuteCompilerInvocation.cpp ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file holds ExecuteCompilerInvocation(). It is split into its own file to
+// minimize the impact of pulling in essentially everything else in Clang.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/FrontendTool/Utils.h"
+#include "clang/Checker/FrontendActions.h"
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/Driver/CC1Options.h"
+#include "clang/Driver/OptTable.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendPluginRegistry.h"
+#include "clang/Rewrite/FrontendActions.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/System/DynamicLibrary.h"
+using namespace clang;
+
+static FrontendAction *CreateFrontendBaseAction(CompilerInstance &CI) {
+  using namespace clang::frontend;
+
+  switch (CI.getFrontendOpts().ProgramAction) {
+  default:
+    llvm_unreachable("Invalid program action!");
+
+  case ASTDump:                return new ASTDumpAction();
+  case ASTPrint:               return new ASTPrintAction();
+  case ASTPrintXML:            return new ASTPrintXMLAction();
+  case ASTView:                return new ASTViewAction();
+  case BoostCon:               return new BoostConAction();
+  case CreateModule:           return 0;
+  case DumpRawTokens:          return new DumpRawTokensAction();
+  case DumpTokens:             return new DumpTokensAction();
+  case EmitAssembly:           return new EmitAssemblyAction();
+  case EmitBC:                 return new EmitBCAction();
+  case EmitHTML:               return new HTMLPrintAction();
+  case EmitLLVM:               return new EmitLLVMAction();
+  case EmitLLVMOnly:           return new EmitLLVMOnlyAction();
+  case EmitCodeGenOnly:        return new EmitCodeGenOnlyAction();
+  case EmitObj:                return new EmitObjAction();
+  case FixIt:                  return new FixItAction();
+  case GeneratePCH:            return new GeneratePCHAction();
+  case GeneratePTH:            return new GeneratePTHAction();
+  case InheritanceView:        return new InheritanceViewAction();
+  case InitOnly:               return new InitOnlyAction();
+  case ParseSyntaxOnly:        return new SyntaxOnlyAction();
+
+  case PluginAction: {
+    for (FrontendPluginRegistry::iterator it =
+           FrontendPluginRegistry::begin(), ie = FrontendPluginRegistry::end();
+         it != ie; ++it) {
+      if (it->getName() == CI.getFrontendOpts().ActionName) {
+        llvm::OwningPtr<PluginASTAction> P(it->instantiate());
+        if (!P->ParseArgs(CI, CI.getFrontendOpts().PluginArgs))
+          return 0;
+        return P.take();
+      }
+    }
+
+    CI.getDiagnostics().Report(diag::err_fe_invalid_plugin_name)
+      << CI.getFrontendOpts().ActionName;
+    return 0;
+  }
+
+  case PrintDeclContext:       return new DeclContextPrintAction();
+  case PrintPreamble:          return new PrintPreambleAction();
+  case PrintPreprocessedInput: return new PrintPreprocessedAction();
+  case RewriteMacros:          return new RewriteMacrosAction();
+  case RewriteObjC:            return new RewriteObjCAction();
+  case RewriteTest:            return new RewriteTestAction();
+  case RunAnalysis:            return new AnalysisAction();
+  case RunPreprocessorOnly:    return new PreprocessOnlyAction();
+  }
+}
+
+static FrontendAction *CreateFrontendAction(CompilerInstance &CI) {
+  // Create the underlying action.
+  FrontendAction *Act = CreateFrontendBaseAction(CI);
+  if (!Act)
+    return 0;
+
+  // If there are any AST files to merge, create a frontend action
+  // adaptor to perform the merge.
+  if (!CI.getFrontendOpts().ASTMergeFiles.empty())
+    Act = new ASTMergeAction(Act, &CI.getFrontendOpts().ASTMergeFiles[0],
+                             CI.getFrontendOpts().ASTMergeFiles.size());
+
+  return Act;
+}
+
+bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
+  // Honor -help.
+  if (Clang->getFrontendOpts().ShowHelp) {
+    llvm::OwningPtr<driver::OptTable> Opts(driver::createCC1OptTable());
+    Opts->PrintHelp(llvm::outs(), "clang -cc1",
+                    "LLVM 'Clang' Compiler: http://clang.llvm.org");
+    return 0;
+  }
+
+  // Honor -version.
+  //
+  // FIXME: Use a better -version message?
+  if (Clang->getFrontendOpts().ShowVersion) {
+    llvm::cl::PrintVersionMessage();
+    return 0;
+  }
+
+  // Honor -mllvm.
+  //
+  // FIXME: Remove this, one day.
+  if (!Clang->getFrontendOpts().LLVMArgs.empty()) {
+    unsigned NumArgs = Clang->getFrontendOpts().LLVMArgs.size();
+    const char **Args = new const char*[NumArgs + 2];
+    Args[0] = "clang (LLVM option parsing)";
+    for (unsigned i = 0; i != NumArgs; ++i)
+      Args[i + 1] = Clang->getFrontendOpts().LLVMArgs[i].c_str();
+    Args[NumArgs + 1] = 0;
+    llvm::cl::ParseCommandLineOptions(NumArgs + 1, const_cast<char **>(Args));
+  }
+
+  // Load any requested plugins.
+  for (unsigned i = 0,
+         e = Clang->getFrontendOpts().Plugins.size(); i != e; ++i) {
+    const std::string &Path = Clang->getFrontendOpts().Plugins[i];
+    std::string Error;
+    if (llvm::sys::DynamicLibrary::LoadLibraryPermanently(Path.c_str(), &Error))
+      Clang->getDiagnostics().Report(diag::err_fe_unable_to_load_plugin)
+        << Path << Error;
+  }
+
+  // If there were errors in processing arguments, don't do anything else.
+  bool Success = false;
+  if (!Clang->getDiagnostics().getNumErrors()) {
+    // Create and execute the frontend action.
+    llvm::OwningPtr<FrontendAction> Act(CreateFrontendAction(*Clang));
+    if (Act) {
+      Success = Clang->ExecuteAction(*Act);
+      if (Clang->getFrontendOpts().DisableFree)
+        Act.take();
+    }
+  }
+
+  return Success;
+}