Add the clang library to the repo (with some of my changes, too).

31 files changed, 15106 insertions, 0 deletions

diff --git a/clang/lib/Frontend/ASTConsumers.cpp b/clang/lib/Frontend/ASTConsumers.cpp
new file mode 100644
index 0000000..390ae09
--- /dev/null
+++ b/clang/lib/Frontend/ASTConsumers.cpp
@@ -0,0 +1,422 @@
+//===--- ASTConsumers.cpp - ASTConsumer implementations -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// AST Consumer Implementations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ASTConsumers.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/AST/AST.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/AST/PrettyPrinter.h"
+#include "llvm/Module.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Path.h"
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+/// ASTPrinter - Pretty-printer and dumper of ASTs
+
+namespace {
+  class ASTPrinter : public ASTConsumer {
+    raw_ostream &Out;
+    bool Dump;
+
+  public:
+    ASTPrinter(raw_ostream* o = NULL, bool Dump = false)
+      : Out(o? *o : llvm::outs()), Dump(Dump) { }
+
+    virtual void HandleTranslationUnit(ASTContext &Context) {
+      PrintingPolicy Policy = Context.getPrintingPolicy();
+      Policy.Dump = Dump;
+      Context.getTranslationUnitDecl()->print(Out, Policy, /*Indentation=*/0,
+                                              /*PrintInstantiation=*/true);
+    }
+  };
+} // end anonymous namespace
+
+ASTConsumer *clang::CreateASTPrinter(raw_ostream* out) {
+  return new ASTPrinter(out);
+}
+
+ASTConsumer *clang::CreateASTDumper() {
+  return new ASTPrinter(0, true);
+}
+
+//===----------------------------------------------------------------------===//
+/// ASTViewer - AST Visualization
+
+namespace {
+  class ASTViewer : public ASTConsumer {
+    ASTContext *Context;
+  public:
+    void Initialize(ASTContext &Context) {
+      this->Context = &Context;
+    }
+
+    virtual bool HandleTopLevelDecl(DeclGroupRef D) {
+      for (DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; ++I)
+        HandleTopLevelSingleDecl(*I);
+      return true;
+    }
+
+    void HandleTopLevelSingleDecl(Decl *D);
+  };
+}
+
+void ASTViewer::HandleTopLevelSingleDecl(Decl *D) {
+  if (isa<FunctionDecl>(D) || isa<ObjCMethodDecl>(D)) {
+    D->print(llvm::errs());
+  
+    if (Stmt *Body = D->getBody()) {
+      llvm::errs() << '\n';
+      Body->viewAST();
+      llvm::errs() << '\n';
+    }
+  }
+}
+
+
+ASTConsumer *clang::CreateASTViewer() { return new ASTViewer(); }
+
+//===----------------------------------------------------------------------===//
+/// DeclContextPrinter - Decl and DeclContext Visualization
+
+namespace {
+
+class DeclContextPrinter : public ASTConsumer {
+  raw_ostream& Out;
+public:
+  DeclContextPrinter() : Out(llvm::errs()) {}
+
+  void HandleTranslationUnit(ASTContext &C) {
+    PrintDeclContext(C.getTranslationUnitDecl(), 4);
+  }
+
+  void PrintDeclContext(const DeclContext* DC, unsigned Indentation);
+};
+}  // end anonymous namespace
+
+void DeclContextPrinter::PrintDeclContext(const DeclContext* DC,
+                                          unsigned Indentation) {
+  // Print DeclContext name.
+  switch (DC->getDeclKind()) {
+  case Decl::TranslationUnit:
+    Out << "[translation unit] " << DC;
+    break;
+  case Decl::Namespace: {
+    Out << "[namespace] ";
+    const NamespaceDecl* ND = cast<NamespaceDecl>(DC);
+    Out << *ND;
+    break;
+  }
+  case Decl::Enum: {
+    const EnumDecl* ED = cast<EnumDecl>(DC);
+    if (ED->isCompleteDefinition())
+      Out << "[enum] ";
+    else
+      Out << "<enum> ";
+    Out << *ED;
+    break;
+  }
+  case Decl::Record: {
+    const RecordDecl* RD = cast<RecordDecl>(DC);
+    if (RD->isCompleteDefinition())
+      Out << "[struct] ";
+    else
+      Out << "<struct> ";
+    Out << *RD;
+    break;
+  }
+  case Decl::CXXRecord: {
+    const CXXRecordDecl* RD = cast<CXXRecordDecl>(DC);
+    if (RD->isCompleteDefinition())
+      Out << "[class] ";
+    else
+      Out << "<class> ";
+    Out << *RD << ' ' << DC;
+    break;
+  }
+  case Decl::ObjCMethod:
+    Out << "[objc method]";
+    break;
+  case Decl::ObjCInterface:
+    Out << "[objc interface]";
+    break;
+  case Decl::ObjCCategory:
+    Out << "[objc category]";
+    break;
+  case Decl::ObjCProtocol:
+    Out << "[objc protocol]";
+    break;
+  case Decl::ObjCImplementation:
+    Out << "[objc implementation]";
+    break;
+  case Decl::ObjCCategoryImpl:
+    Out << "[objc categoryimpl]";
+    break;
+  case Decl::LinkageSpec:
+    Out << "[linkage spec]";
+    break;
+  case Decl::Block:
+    Out << "[block]";
+    break;
+  case Decl::Function: {
+    const FunctionDecl* FD = cast<FunctionDecl>(DC);
+    if (FD->doesThisDeclarationHaveABody())
+      Out << "[function] ";
+    else
+      Out << "<function> ";
+    Out << *FD;
+    // Print the parameters.
+    Out << "(";
+    bool PrintComma = false;
+    for (FunctionDecl::param_const_iterator I = FD->param_begin(),
+           E = FD->param_end(); I != E; ++I) {
+      if (PrintComma)
+        Out << ", ";
+      else
+        PrintComma = true;
+      Out << **I;
+    }
+    Out << ")";
+    break;
+  }
+  case Decl::CXXMethod: {
+    const CXXMethodDecl* D = cast<CXXMethodDecl>(DC);
+    if (D->isOutOfLine())
+      Out << "[c++ method] ";
+    else if (D->isImplicit())
+      Out << "(c++ method) ";
+    else
+      Out << "<c++ method> ";
+    Out << *D;
+    // Print the parameters.
+    Out << "(";
+    bool PrintComma = false;
+    for (FunctionDecl::param_const_iterator I = D->param_begin(),
+           E = D->param_end(); I != E; ++I) {
+      if (PrintComma)
+        Out << ", ";
+      else
+        PrintComma = true;
+      Out << **I;
+    }
+    Out << ")";
+
+    // Check the semantic DeclContext.
+    const DeclContext* SemaDC = D->getDeclContext();
+    const DeclContext* LexicalDC = D->getLexicalDeclContext();
+    if (SemaDC != LexicalDC)
+      Out << " [[" << SemaDC << "]]";
+
+    break;
+  }
+  case Decl::CXXConstructor: {
+    const CXXConstructorDecl* D = cast<CXXConstructorDecl>(DC);
+    if (D->isOutOfLine())
+      Out << "[c++ ctor] ";
+    else if (D->isImplicit())
+      Out << "(c++ ctor) ";
+    else
+      Out << "<c++ ctor> ";
+    Out << *D;
+    // Print the parameters.
+    Out << "(";
+    bool PrintComma = false;
+    for (FunctionDecl::param_const_iterator I = D->param_begin(),
+           E = D->param_end(); I != E; ++I) {
+      if (PrintComma)
+        Out << ", ";
+      else
+        PrintComma = true;
+      Out << **I;
+    }
+    Out << ")";
+
+    // Check the semantic DC.
+    const DeclContext* SemaDC = D->getDeclContext();
+    const DeclContext* LexicalDC = D->getLexicalDeclContext();
+    if (SemaDC != LexicalDC)
+      Out << " [[" << SemaDC << "]]";
+    break;
+  }
+  case Decl::CXXDestructor: {
+    const CXXDestructorDecl* D = cast<CXXDestructorDecl>(DC);
+    if (D->isOutOfLine())
+      Out << "[c++ dtor] ";
+    else if (D->isImplicit())
+      Out << "(c++ dtor) ";
+    else
+      Out << "<c++ dtor> ";
+    Out << *D;
+    // Check the semantic DC.
+    const DeclContext* SemaDC = D->getDeclContext();
+    const DeclContext* LexicalDC = D->getLexicalDeclContext();
+    if (SemaDC != LexicalDC)
+      Out << " [[" << SemaDC << "]]";
+    break;
+  }
+  case Decl::CXXConversion: {
+    const CXXConversionDecl* D = cast<CXXConversionDecl>(DC);
+    if (D->isOutOfLine())
+      Out << "[c++ conversion] ";
+    else if (D->isImplicit())
+      Out << "(c++ conversion) ";
+    else
+      Out << "<c++ conversion> ";
+    Out << *D;
+    // Check the semantic DC.
+    const DeclContext* SemaDC = D->getDeclContext();
+    const DeclContext* LexicalDC = D->getLexicalDeclContext();
+    if (SemaDC != LexicalDC)
+      Out << " [[" << SemaDC << "]]";
+    break;
+  }
+
+  default:
+    llvm_unreachable("a decl that inherits DeclContext isn't handled");
+  }
+
+  Out << "\n";
+
+  // Print decls in the DeclContext.
+  for (DeclContext::decl_iterator I = DC->decls_begin(), E = DC->decls_end();
+       I != E; ++I) {
+    for (unsigned i = 0; i < Indentation; ++i)
+      Out << "  ";
+
+    Decl::Kind DK = I->getKind();
+    switch (DK) {
+    case Decl::Namespace:
+    case Decl::Enum:
+    case Decl::Record:
+    case Decl::CXXRecord:
+    case Decl::ObjCMethod:
+    case Decl::ObjCInterface:
+    case Decl::ObjCCategory:
+    case Decl::ObjCProtocol:
+    case Decl::ObjCImplementation:
+    case Decl::ObjCCategoryImpl:
+    case Decl::LinkageSpec:
+    case Decl::Block:
+    case Decl::Function:
+    case Decl::CXXMethod:
+    case Decl::CXXConstructor:
+    case Decl::CXXDestructor:
+    case Decl::CXXConversion:
+    {
+      DeclContext* DC = cast<DeclContext>(*I);
+      PrintDeclContext(DC, Indentation+2);
+      break;
+    }
+    case Decl::IndirectField: {
+      IndirectFieldDecl* IFD = cast<IndirectFieldDecl>(*I);
+      Out << "<IndirectField> " << *IFD << '\n';
+      break;
+    }
+    case Decl::Label: {
+      LabelDecl *LD = cast<LabelDecl>(*I);
+      Out << "<Label> " << *LD << '\n';
+      break;
+    }
+    case Decl::Field: {
+      FieldDecl *FD = cast<FieldDecl>(*I);
+      Out << "<field> " << *FD << '\n';
+      break;
+    }
+    case Decl::Typedef:
+    case Decl::TypeAlias: {
+      TypedefNameDecl* TD = cast<TypedefNameDecl>(*I);
+      Out << "<typedef> " << *TD << '\n';
+      break;
+    }
+    case Decl::EnumConstant: {
+      EnumConstantDecl* ECD = cast<EnumConstantDecl>(*I);
+      Out << "<enum constant> " << *ECD << '\n';
+      break;
+    }
+    case Decl::Var: {
+      VarDecl* VD = cast<VarDecl>(*I);
+      Out << "<var> " << *VD << '\n';
+      break;
+    }
+    case Decl::ImplicitParam: {
+      ImplicitParamDecl* IPD = cast<ImplicitParamDecl>(*I);
+      Out << "<implicit parameter> " << *IPD << '\n';
+      break;
+    }
+    case Decl::ParmVar: {
+      ParmVarDecl* PVD = cast<ParmVarDecl>(*I);
+      Out << "<parameter> " << *PVD << '\n';
+      break;
+    }
+    case Decl::ObjCProperty: {
+      ObjCPropertyDecl* OPD = cast<ObjCPropertyDecl>(*I);
+      Out << "<objc property> " << *OPD << '\n';
+      break;
+    }
+    case Decl::FunctionTemplate: {
+      FunctionTemplateDecl* FTD = cast<FunctionTemplateDecl>(*I);
+      Out << "<function template> " << *FTD << '\n';
+      break;
+    }
+    case Decl::FileScopeAsm: {
+      Out << "<file-scope asm>\n";
+      break;
+    }
+    case Decl::UsingDirective: {
+      Out << "<using directive>\n";
+      break;
+    }
+    case Decl::NamespaceAlias: {
+      NamespaceAliasDecl* NAD = cast<NamespaceAliasDecl>(*I);
+      Out << "<namespace alias> " << *NAD << '\n';
+      break;
+    }
+    case Decl::ClassTemplate: {
+      ClassTemplateDecl *CTD = cast<ClassTemplateDecl>(*I);
+      Out << "<class template> " << *CTD << '\n';
+      break;
+    }
+    default:
+      Out << "DeclKind: " << DK << '"' << *I << "\"\n";
+      llvm_unreachable("decl unhandled");
+    }
+  }
+}
+ASTConsumer *clang::CreateDeclContextPrinter() {
+  return new DeclContextPrinter();
+}
+
+//===----------------------------------------------------------------------===//
+/// ASTDumperXML - In-depth XML dumping.
+
+namespace {
+class ASTDumpXML : public ASTConsumer {
+  raw_ostream &OS;
+
+public:
+  ASTDumpXML(raw_ostream &OS) : OS(OS) {}
+
+  void HandleTranslationUnit(ASTContext &C) {
+    C.getTranslationUnitDecl()->dumpXML(OS);
+  }  
+};
+}
+
+ASTConsumer *clang::CreateASTDumperXML(raw_ostream &OS) {
+  return new ASTDumpXML(OS);
+}
diff --git a/clang/lib/Frontend/ASTMerge.cpp b/clang/lib/Frontend/ASTMerge.cpp
new file mode 100644
index 0000000..9feb3de
--- /dev/null
+++ b/clang/lib/Frontend/ASTMerge.cpp
@@ -0,0 +1,109 @@
+//===-- ASTMerge.cpp - AST Merging Frontent Action --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTDiagnostic.h"
+#include "clang/AST/ASTImporter.h"
+#include "clang/Basic/Diagnostic.h"
+
+using namespace clang;
+
+ASTConsumer *ASTMergeAction::CreateASTConsumer(CompilerInstance &CI,
+                                               StringRef InFile) {
+  return AdaptedAction->CreateASTConsumer(CI, InFile);
+}
+
+bool ASTMergeAction::BeginSourceFileAction(CompilerInstance &CI,
+                                           StringRef Filename) {
+  // FIXME: This is a hack. We need a better way to communicate the
+  // AST file, compiler instance, and file name than member variables
+  // of FrontendAction.
+  AdaptedAction->setCurrentInput(getCurrentInput(), takeCurrentASTUnit());
+  AdaptedAction->setCompilerInstance(&CI);
+  return AdaptedAction->BeginSourceFileAction(CI, Filename);
+}
+
+void ASTMergeAction::ExecuteAction() {
+  CompilerInstance &CI = getCompilerInstance();
+  CI.getDiagnostics().getClient()->BeginSourceFile(
+                                         CI.getASTContext().getLangOpts());
+  CI.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
+                                       &CI.getASTContext());
+  IntrusiveRefCntPtr<DiagnosticIDs>
+      DiagIDs(CI.getDiagnostics().getDiagnosticIDs());
+  for (unsigned I = 0, N = ASTFiles.size(); I != N; ++I) {
+    IntrusiveRefCntPtr<DiagnosticsEngine>
+        Diags(new DiagnosticsEngine(DiagIDs, CI.getDiagnostics().getClient(),
+                             /*ShouldOwnClient=*/false));
+    ASTUnit *Unit = ASTUnit::LoadFromASTFile(ASTFiles[I], Diags,
+                                             CI.getFileSystemOpts(), false);
+    if (!Unit)
+      continue;
+
+    ASTImporter Importer(CI.getASTContext(), 
+                         CI.getFileManager(),
+                         Unit->getASTContext(), 
+                         Unit->getFileManager(),
+                         /*MinimalImport=*/false);
+
+    TranslationUnitDecl *TU = Unit->getASTContext().getTranslationUnitDecl();
+    for (DeclContext::decl_iterator D = TU->decls_begin(), 
+                                 DEnd = TU->decls_end();
+         D != DEnd; ++D) {
+      // Don't re-import __va_list_tag, __builtin_va_list.
+      if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
+        if (IdentifierInfo *II = ND->getIdentifier())
+          if (II->isStr("__va_list_tag") || II->isStr("__builtin_va_list"))
+            continue;
+      
+      Importer.Import(*D);
+    }
+
+    delete Unit;
+  }
+
+  AdaptedAction->ExecuteAction();
+  CI.getDiagnostics().getClient()->EndSourceFile();
+}
+
+void ASTMergeAction::EndSourceFileAction() {
+  return AdaptedAction->EndSourceFileAction();
+}
+
+ASTMergeAction::ASTMergeAction(FrontendAction *AdaptedAction,
+                               ArrayRef<std::string> ASTFiles)
+  : AdaptedAction(AdaptedAction), ASTFiles(ASTFiles.begin(), ASTFiles.end()) {
+  assert(AdaptedAction && "ASTMergeAction needs an action to adapt");
+}
+
+ASTMergeAction::~ASTMergeAction() { 
+  delete AdaptedAction;
+}
+
+bool ASTMergeAction::usesPreprocessorOnly() const {
+  return AdaptedAction->usesPreprocessorOnly();
+}
+
+TranslationUnitKind ASTMergeAction::getTranslationUnitKind() {
+  return AdaptedAction->getTranslationUnitKind();
+}
+
+bool ASTMergeAction::hasPCHSupport() const {
+  return AdaptedAction->hasPCHSupport();
+}
+
+bool ASTMergeAction::hasASTFileSupport() const {
+  return AdaptedAction->hasASTFileSupport();
+}
+
+bool ASTMergeAction::hasCodeCompletionSupport() const {
+  return AdaptedAction->hasCodeCompletionSupport();
+}
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
new file mode 100644
index 0000000..7aa9603
--- /dev/null
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -0,0 +1,2775 @@
+//===--- ASTUnit.cpp - ASTUnit utility ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// ASTUnit Implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/DeclVisitor.h"
+#include "clang/AST/TypeOrdering.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Driver/Compilation.h"
+#include "clang/Driver/Driver.h"
+#include "clang/Driver/Job.h"
+#include "clang/Driver/ArgList.h"
+#include "clang/Driver/Options.h"
+#include "clang/Driver/Tool.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "clang/Frontend/MultiplexConsumer.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Serialization/ASTReader.h"
+#include "clang/Serialization/ASTWriter.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/TargetOptions.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/Atomic.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Mutex.h"
+#include "llvm/Support/MutexGuard.h"
+#include "llvm/Support/CrashRecoveryContext.h"
+#include <cstdlib>
+#include <cstdio>
+#include <sys/stat.h>
+using namespace clang;
+
+using llvm::TimeRecord;
+
+namespace {
+  class SimpleTimer {
+    bool WantTiming;
+    TimeRecord Start;
+    std::string Output;
+
+  public:
+    explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
+      if (WantTiming)
+        Start = TimeRecord::getCurrentTime();
+    }
+
+    void setOutput(const Twine &Output) {
+      if (WantTiming)
+        this->Output = Output.str();
+    }
+
+    ~SimpleTimer() {
+      if (WantTiming) {
+        TimeRecord Elapsed = TimeRecord::getCurrentTime();
+        Elapsed -= Start;
+        llvm::errs() << Output << ':';
+        Elapsed.print(Elapsed, llvm::errs());
+        llvm::errs() << '\n';
+      }
+    }
+  };
+  
+  struct OnDiskData {
+    /// \brief The file in which the precompiled preamble is stored.
+    std::string PreambleFile;
+
+    /// \brief Temporary files that should be removed when the ASTUnit is 
+    /// destroyed.
+    SmallVector<llvm::sys::Path, 4> TemporaryFiles;
+    
+    /// \brief Erase temporary files.
+    void CleanTemporaryFiles();
+
+    /// \brief Erase the preamble file.
+    void CleanPreambleFile();
+
+    /// \brief Erase temporary files and the preamble file.
+    void Cleanup();
+  };
+}
+
+static llvm::sys::SmartMutex<false> &getOnDiskMutex() {
+  static llvm::sys::SmartMutex<false> M(/* recursive = */ true);
+  return M;
+}
+
+static void cleanupOnDiskMapAtExit(void);
+
+typedef llvm::DenseMap<const ASTUnit *, OnDiskData *> OnDiskDataMap;
+static OnDiskDataMap &getOnDiskDataMap() {
+  static OnDiskDataMap M;
+  static bool hasRegisteredAtExit = false;
+  if (!hasRegisteredAtExit) {
+    hasRegisteredAtExit = true;
+    atexit(cleanupOnDiskMapAtExit);
+  }
+  return M;
+}
+
+static void cleanupOnDiskMapAtExit(void) {
+  // No mutex required here since we are leaving the program.
+  OnDiskDataMap &M = getOnDiskDataMap();
+  for (OnDiskDataMap::iterator I = M.begin(), E = M.end(); I != E; ++I) {
+    // We don't worry about freeing the memory associated with OnDiskDataMap.
+    // All we care about is erasing stale files.
+    I->second->Cleanup();
+  }
+}
+
+static OnDiskData &getOnDiskData(const ASTUnit *AU) {
+  // We require the mutex since we are modifying the structure of the
+  // DenseMap.
+  llvm::MutexGuard Guard(getOnDiskMutex());
+  OnDiskDataMap &M = getOnDiskDataMap();
+  OnDiskData *&D = M[AU];
+  if (!D)
+    D = new OnDiskData();
+  return *D;
+}
+
+static void erasePreambleFile(const ASTUnit *AU) {
+  getOnDiskData(AU).CleanPreambleFile();
+}
+
+static void removeOnDiskEntry(const ASTUnit *AU) {
+  // We require the mutex since we are modifying the structure of the
+  // DenseMap.
+  llvm::MutexGuard Guard(getOnDiskMutex());
+  OnDiskDataMap &M = getOnDiskDataMap();
+  OnDiskDataMap::iterator I = M.find(AU);
+  if (I != M.end()) {
+    I->second->Cleanup();
+    delete I->second;
+    M.erase(AU);
+  }
+}
+
+static void setPreambleFile(const ASTUnit *AU, llvm::StringRef preambleFile) {
+  getOnDiskData(AU).PreambleFile = preambleFile;
+}
+
+static const std::string &getPreambleFile(const ASTUnit *AU) {
+  return getOnDiskData(AU).PreambleFile;  
+}
+
+void OnDiskData::CleanTemporaryFiles() {
+  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
+    TemporaryFiles[I].eraseFromDisk();
+  TemporaryFiles.clear(); 
+}
+
+void OnDiskData::CleanPreambleFile() {
+  if (!PreambleFile.empty()) {
+    llvm::sys::Path(PreambleFile).eraseFromDisk();
+    PreambleFile.clear();
+  }
+}
+
+void OnDiskData::Cleanup() {
+  CleanTemporaryFiles();
+  CleanPreambleFile();
+}
+
+void ASTUnit::clearFileLevelDecls() {
+  for (FileDeclsTy::iterator
+         I = FileDecls.begin(), E = FileDecls.end(); I != E; ++I)
+    delete I->second;
+  FileDecls.clear();
+}
+
+void ASTUnit::CleanTemporaryFiles() {
+  getOnDiskData(this).CleanTemporaryFiles();
+}
+
+void ASTUnit::addTemporaryFile(const llvm::sys::Path &TempFile) {
+  getOnDiskData(this).TemporaryFiles.push_back(TempFile);
+}
+
+/// \brief After failing to build a precompiled preamble (due to
+/// errors in the source that occurs in the preamble), the number of
+/// reparses during which we'll skip even trying to precompile the
+/// preamble.
+const unsigned DefaultPreambleRebuildInterval = 5;
+
+/// \brief Tracks the number of ASTUnit objects that are currently active.
+///
+/// Used for debugging purposes only.
+static llvm::sys::cas_flag ActiveASTUnitObjects;
+
+ASTUnit::ASTUnit(bool _MainFileIsAST)
+  : Reader(0), OnlyLocalDecls(false), CaptureDiagnostics(false),
+    MainFileIsAST(_MainFileIsAST), 
+    TUKind(TU_Complete), WantTiming(getenv("LIBCLANG_TIMING")),
+    OwnsRemappedFileBuffers(true),
+    NumStoredDiagnosticsFromDriver(0),
+    PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
+    NumWarningsInPreamble(0),
+    ShouldCacheCodeCompletionResults(false),
+    CompletionCacheTopLevelHashValue(0),
+    PreambleTopLevelHashValue(0),
+    CurrentTopLevelHashValue(0),
+    UnsafeToFree(false) { 
+  if (getenv("LIBCLANG_OBJTRACKING")) {
+    llvm::sys::AtomicIncrement(&ActiveASTUnitObjects);
+    fprintf(stderr, "+++ %d translation units\n", ActiveASTUnitObjects);
+  }    
+}
+
+ASTUnit::~ASTUnit() {
+  clearFileLevelDecls();
+
+  // Clean up the temporary files and the preamble file.
+  removeOnDiskEntry(this);
+
+  // Free the buffers associated with remapped files. We are required to
+  // perform this operation here because we explicitly request that the
+  // compiler instance *not* free these buffers for each invocation of the
+  // parser.
+  if (Invocation.getPtr() && OwnsRemappedFileBuffers) {
+    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
+    for (PreprocessorOptions::remapped_file_buffer_iterator
+           FB = PPOpts.remapped_file_buffer_begin(),
+           FBEnd = PPOpts.remapped_file_buffer_end();
+         FB != FBEnd;
+         ++FB)
+      delete FB->second;
+  }
+  
+  delete SavedMainFileBuffer;
+  delete PreambleBuffer;
+
+  ClearCachedCompletionResults();  
+  
+  if (getenv("LIBCLANG_OBJTRACKING")) {
+    llvm::sys::AtomicDecrement(&ActiveASTUnitObjects);
+    fprintf(stderr, "--- %d translation units\n", ActiveASTUnitObjects);
+  }    
+}
+
+void ASTUnit::setPreprocessor(Preprocessor *pp) { PP = pp; }
+
+/// \brief Determine the set of code-completion contexts in which this 
+/// declaration should be shown.
+static unsigned getDeclShowContexts(NamedDecl *ND,
+                                    const LangOptions &LangOpts,
+                                    bool &IsNestedNameSpecifier) {
+  IsNestedNameSpecifier = false;
+  
+  if (isa<UsingShadowDecl>(ND))
+    ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
+  if (!ND)
+    return 0;
+  
+  unsigned Contexts = 0;
+  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) || 
+      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
+    // Types can appear in these contexts.
+    if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
+      Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
+                | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
+                | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
+                | (1 << (CodeCompletionContext::CCC_Statement - 1))
+                | (1 << (CodeCompletionContext::CCC_Type - 1))
+              | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
+
+    // In C++, types can appear in expressions contexts (for functional casts).
+    if (LangOpts.CPlusPlus)
+      Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
+    
+    // In Objective-C, message sends can send interfaces. In Objective-C++,
+    // all types are available due to functional casts.
+    if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
+      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
+    
+    // In Objective-C, you can only be a subclass of another Objective-C class
+    if (isa<ObjCInterfaceDecl>(ND))
+      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCInterfaceName - 1));
+
+    // Deal with tag names.
+    if (isa<EnumDecl>(ND)) {
+      Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
+      
+      // Part of the nested-name-specifier in C++0x.
+      if (LangOpts.CPlusPlus0x)
+        IsNestedNameSpecifier = true;
+    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
+      if (Record->isUnion())
+        Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
+      else
+        Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
+      
+      if (LangOpts.CPlusPlus)
+        IsNestedNameSpecifier = true;
+    } else if (isa<ClassTemplateDecl>(ND))
+      IsNestedNameSpecifier = true;
+  } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
+    // Values can appear in these contexts.
+    Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
+             | (1 << (CodeCompletionContext::CCC_Expression - 1))
+             | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
+             | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
+  } else if (isa<ObjCProtocolDecl>(ND)) {
+    Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
+  } else if (isa<ObjCCategoryDecl>(ND)) {
+    Contexts = (1 << (CodeCompletionContext::CCC_ObjCCategoryName - 1));
+  } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
+    Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
+   
+    // Part of the nested-name-specifier.
+    IsNestedNameSpecifier = true;
+  }
+  
+  return Contexts;
+}
+
+void ASTUnit::CacheCodeCompletionResults() {
+  if (!TheSema)
+    return;
+  
+  SimpleTimer Timer(WantTiming);
+  Timer.setOutput("Cache global code completions for " + getMainFileName());
+
+  // Clear out the previous results.
+  ClearCachedCompletionResults();
+  
+  // Gather the set of global code completions.
+  typedef CodeCompletionResult Result;
+  SmallVector<Result, 8> Results;
+  CachedCompletionAllocator = new GlobalCodeCompletionAllocator;
+  TheSema->GatherGlobalCodeCompletions(*CachedCompletionAllocator,
+                                       getCodeCompletionTUInfo(), Results);
+  
+  // Translate global code completions into cached completions.
+  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
+  
+  for (unsigned I = 0, N = Results.size(); I != N; ++I) {
+    switch (Results[I].Kind) {
+    case Result::RK_Declaration: {
+      bool IsNestedNameSpecifier = false;
+      CachedCodeCompletionResult CachedResult;
+      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema,
+                                                    *CachedCompletionAllocator,
+                                                    getCodeCompletionTUInfo());
+      CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
+                                                        Ctx->getLangOpts(),
+                                                        IsNestedNameSpecifier);
+      CachedResult.Priority = Results[I].Priority;
+      CachedResult.Kind = Results[I].CursorKind;
+      CachedResult.Availability = Results[I].Availability;
+
+      // Keep track of the type of this completion in an ASTContext-agnostic 
+      // way.
+      QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
+      if (UsageType.isNull()) {
+        CachedResult.TypeClass = STC_Void;
+        CachedResult.Type = 0;
+      } else {
+        CanQualType CanUsageType
+          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
+        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
+
+        // Determine whether we have already seen this type. If so, we save
+        // ourselves the work of formatting the type string by using the 
+        // temporary, CanQualType-based hash table to find the associated value.
+        unsigned &TypeValue = CompletionTypes[CanUsageType];
+        if (TypeValue == 0) {
+          TypeValue = CompletionTypes.size();
+          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
+            = TypeValue;
+        }
+        
+        CachedResult.Type = TypeValue;
+      }
+      
+      CachedCompletionResults.push_back(CachedResult);
+      
+      /// Handle nested-name-specifiers in C++.
+      if (TheSema->Context.getLangOpts().CPlusPlus && 
+          IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
+        // The contexts in which a nested-name-specifier can appear in C++.
+        unsigned NNSContexts
+          = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
+          | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
+          | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
+          | (1 << (CodeCompletionContext::CCC_Statement - 1))
+          | (1 << (CodeCompletionContext::CCC_Expression - 1))
+          | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
+          | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
+          | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
+          | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
+          | (1 << (CodeCompletionContext::CCC_Type - 1))
+          | (1 << (CodeCompletionContext::CCC_PotentiallyQualifiedName - 1))
+          | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
+
+        if (isa<NamespaceDecl>(Results[I].Declaration) ||
+            isa<NamespaceAliasDecl>(Results[I].Declaration))
+          NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
+
+        if (unsigned RemainingContexts 
+                                = NNSContexts & ~CachedResult.ShowInContexts) {
+          // If there any contexts where this completion can be a 
+          // nested-name-specifier but isn't already an option, create a 
+          // nested-name-specifier completion.
+          Results[I].StartsNestedNameSpecifier = true;
+          CachedResult.Completion 
+            = Results[I].CreateCodeCompletionString(*TheSema,
+                                                    *CachedCompletionAllocator,
+                                                    getCodeCompletionTUInfo());
+          CachedResult.ShowInContexts = RemainingContexts;
+          CachedResult.Priority = CCP_NestedNameSpecifier;
+          CachedResult.TypeClass = STC_Void;
+          CachedResult.Type = 0;
+          CachedCompletionResults.push_back(CachedResult);
+        }
+      }
+      break;
+    }
+        
+    case Result::RK_Keyword:
+    case Result::RK_Pattern:
+      // Ignore keywords and patterns; we don't care, since they are so
+      // easily regenerated.
+      break;
+      
+    case Result::RK_Macro: {
+      CachedCodeCompletionResult CachedResult;
+      CachedResult.Completion 
+        = Results[I].CreateCodeCompletionString(*TheSema,
+                                                *CachedCompletionAllocator,
+                                                getCodeCompletionTUInfo());
+      CachedResult.ShowInContexts
+        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
+        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
+        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
+        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
+        | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
+        | (1 << (CodeCompletionContext::CCC_Statement - 1))
+        | (1 << (CodeCompletionContext::CCC_Expression - 1))
+        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
+        | (1 << (CodeCompletionContext::CCC_MacroNameUse - 1))
+        | (1 << (CodeCompletionContext::CCC_PreprocessorExpression - 1))
+        | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
+        | (1 << (CodeCompletionContext::CCC_OtherWithMacros - 1));
+      
+      CachedResult.Priority = Results[I].Priority;
+      CachedResult.Kind = Results[I].CursorKind;
+      CachedResult.Availability = Results[I].Availability;
+      CachedResult.TypeClass = STC_Void;
+      CachedResult.Type = 0;
+      CachedCompletionResults.push_back(CachedResult);
+      break;
+    }
+    }
+  }
+  
+  // Save the current top-level hash value.
+  CompletionCacheTopLevelHashValue = CurrentTopLevelHashValue;
+}
+
+void ASTUnit::ClearCachedCompletionResults() {
+  CachedCompletionResults.clear();
+  CachedCompletionTypes.clear();
+  CachedCompletionAllocator = 0;
+}
+
+namespace {
+
+/// \brief Gathers information from ASTReader that will be used to initialize
+/// a Preprocessor.
+class ASTInfoCollector : public ASTReaderListener {
+  Preprocessor &PP;
+  ASTContext &Context;
+  LangOptions &LangOpt;
+  HeaderSearch &HSI;
+  IntrusiveRefCntPtr<TargetInfo> &Target;
+  std::string &Predefines;
+  unsigned &Counter;
+
+  unsigned NumHeaderInfos;
+
+  bool InitializedLanguage;
+public:
+  ASTInfoCollector(Preprocessor &PP, ASTContext &Context, LangOptions &LangOpt, 
+                   HeaderSearch &HSI,
+                   IntrusiveRefCntPtr<TargetInfo> &Target,
+                   std::string &Predefines,
+                   unsigned &Counter)
+    : PP(PP), Context(Context), LangOpt(LangOpt), HSI(HSI), Target(Target),
+      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0),
+      InitializedLanguage(false) {}
+
+  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
+    if (InitializedLanguage)
+      return false;
+    
+    LangOpt = LangOpts;
+    
+    // Initialize the preprocessor.
+    PP.Initialize(*Target);
+    
+    // Initialize the ASTContext
+    Context.InitBuiltinTypes(*Target);
+    
+    InitializedLanguage = true;
+    return false;
+  }
+
+  virtual bool ReadTargetTriple(StringRef Triple) {
+    // If we've already initialized the target, don't do it again.
+    if (Target)
+      return false;
+    
+    // FIXME: This is broken, we should store the TargetOptions in the AST file.
+    TargetOptions TargetOpts;
+    TargetOpts.ABI = "";
+    TargetOpts.CXXABI = "";
+    TargetOpts.CPU = "";
+    TargetOpts.Features.clear();
+    TargetOpts.Triple = Triple;
+    Target = TargetInfo::CreateTargetInfo(PP.getDiagnostics(), TargetOpts);
+    return false;
+  }
+
+  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
+                                    StringRef OriginalFileName,
+                                    std::string &SuggestedPredefines,
+                                    FileManager &FileMgr) {
+    Predefines = Buffers[0].Data;
+    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
+      Predefines += Buffers[I].Data;
+    }
+    return false;
+  }
+
+  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
+    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
+  }
+
+  virtual void ReadCounter(unsigned Value) {
+    Counter = Value;
+  }
+};
+
+class StoredDiagnosticConsumer : public DiagnosticConsumer {
+  SmallVectorImpl<StoredDiagnostic> &StoredDiags;
+  
+public:
+  explicit StoredDiagnosticConsumer(
+                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
+    : StoredDiags(StoredDiags) { }
+  
+  virtual void HandleDiagnostic(DiagnosticsEngine::Level Level,
+                                const Diagnostic &Info);
+  
+  DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
+    // Just drop any diagnostics that come from cloned consumers; they'll
+    // have different source managers anyway.
+    // FIXME: We'd like to be able to capture these somehow, even if it's just
+    // file/line/column, because they could occur when parsing module maps or
+    // building modules on-demand.
+    return new IgnoringDiagConsumer();
+  }
+};
+
+/// \brief RAII object that optionally captures diagnostics, if
+/// there is no diagnostic client to capture them already.
+class CaptureDroppedDiagnostics {
+  DiagnosticsEngine &Diags;
+  StoredDiagnosticConsumer Client;
+  DiagnosticConsumer *PreviousClient;
+
+public:
+  CaptureDroppedDiagnostics(bool RequestCapture, DiagnosticsEngine &Diags,
+                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
+    : Diags(Diags), Client(StoredDiags), PreviousClient(0)
+  {
+    if (RequestCapture || Diags.getClient() == 0) {
+      PreviousClient = Diags.takeClient();
+      Diags.setClient(&Client);
+    }
+  }
+
+  ~CaptureDroppedDiagnostics() {
+    if (Diags.getClient() == &Client) {
+      Diags.takeClient();
+      Diags.setClient(PreviousClient);
+    }
+  }
+};
+
+} // anonymous namespace
+
+void StoredDiagnosticConsumer::HandleDiagnostic(DiagnosticsEngine::Level Level,
+                                              const Diagnostic &Info) {
+  // Default implementation (Warnings/errors count).
+  DiagnosticConsumer::HandleDiagnostic(Level, Info);
+
+  StoredDiags.push_back(StoredDiagnostic(Level, Info));
+}
+
+const std::string &ASTUnit::getOriginalSourceFileName() {
+  return OriginalSourceFile;
+}
+
+llvm::MemoryBuffer *ASTUnit::getBufferForFile(StringRef Filename,
+                                              std::string *ErrorStr) {
+  assert(FileMgr);
+  return FileMgr->getBufferForFile(Filename, ErrorStr);
+}
+
+/// \brief Configure the diagnostics object for use with ASTUnit.
+void ASTUnit::ConfigureDiags(IntrusiveRefCntPtr<DiagnosticsEngine> &Diags,
+                             const char **ArgBegin, const char **ArgEnd,
+                             ASTUnit &AST, bool CaptureDiagnostics) {
+  if (!Diags.getPtr()) {
+    // No diagnostics engine was provided, so create our own diagnostics object
+    // with the default options.
+    DiagnosticOptions DiagOpts;
+    DiagnosticConsumer *Client = 0;
+    if (CaptureDiagnostics)
+      Client = new StoredDiagnosticConsumer(AST.StoredDiagnostics);
+    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd-ArgBegin,
+                                                ArgBegin, Client,
+                                                /*ShouldOwnClient=*/true,
+                                                /*ShouldCloneClient=*/false);
+  } else if (CaptureDiagnostics) {
+    Diags->setClient(new StoredDiagnosticConsumer(AST.StoredDiagnostics));
+  }
+}
+
+ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
+                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                                  const FileSystemOptions &FileSystemOpts,
+                                  bool OnlyLocalDecls,
+                                  RemappedFile *RemappedFiles,
+                                  unsigned NumRemappedFiles,
+                                  bool CaptureDiagnostics,
+                                  bool AllowPCHWithCompilerErrors) {
+  OwningPtr<ASTUnit> AST(new ASTUnit(true));
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
+    ASTUnitCleanup(AST.get());
+  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
+    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
+    DiagCleanup(Diags.getPtr());
+
+  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
+
+  AST->OnlyLocalDecls = OnlyLocalDecls;
+  AST->CaptureDiagnostics = CaptureDiagnostics;
+  AST->Diagnostics = Diags;
+  AST->FileMgr = new FileManager(FileSystemOpts);
+  AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
+                                     AST->getFileManager());
+  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager(),
+                                         AST->getDiagnostics(),
+                                         AST->ASTFileLangOpts,
+                                         /*Target=*/0));
+  
+  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
+    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
+    if (const llvm::MemoryBuffer *
+          memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
+      // Create the file entry for the file that we're mapping from.
+      const FileEntry *FromFile
+        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
+                                               memBuf->getBufferSize(),
+                                               0);
+      if (!FromFile) {
+        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
+          << RemappedFiles[I].first;
+        delete memBuf;
+        continue;
+      }
+      
+      // Override the contents of the "from" file with the contents of
+      // the "to" file.
+      AST->getSourceManager().overrideFileContents(FromFile, memBuf);
+
+    } else {
+      const char *fname = fileOrBuf.get<const char *>();
+      const FileEntry *ToFile = AST->FileMgr->getFile(fname);
+      if (!ToFile) {
+        AST->getDiagnostics().Report(diag::err_fe_remap_missing_to_file)
+        << RemappedFiles[I].first << fname;
+        continue;
+      }
+
+      // Create the file entry for the file that we're mapping from.
+      const FileEntry *FromFile
+        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
+                                               ToFile->getSize(),
+                                               0);
+      if (!FromFile) {
+        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
+          << RemappedFiles[I].first;
+        delete memBuf;
+        continue;
+      }
+      
+      // Override the contents of the "from" file with the contents of
+      // the "to" file.
+      AST->getSourceManager().overrideFileContents(FromFile, ToFile);
+    }
+  }
+  
+  // Gather Info for preprocessor construction later on.
+
+  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
+  std::string Predefines;
+  unsigned Counter;
+
+  OwningPtr<ASTReader> Reader;
+
+  AST->PP = new Preprocessor(AST->getDiagnostics(), AST->ASTFileLangOpts, 
+                             /*Target=*/0, AST->getSourceManager(), HeaderInfo, 
+                             *AST, 
+                             /*IILookup=*/0,
+                             /*OwnsHeaderSearch=*/false,
+                             /*DelayInitialization=*/true);
+  Preprocessor &PP = *AST->PP;
+
+  AST->Ctx = new ASTContext(AST->ASTFileLangOpts,
+                            AST->getSourceManager(),
+                            /*Target=*/0,
+                            PP.getIdentifierTable(),
+                            PP.getSelectorTable(),
+                            PP.getBuiltinInfo(),
+                            /* size_reserve = */0,
+                            /*DelayInitialization=*/true);
+  ASTContext &Context = *AST->Ctx;
+
+  Reader.reset(new ASTReader(PP, Context,
+                             /*isysroot=*/"",
+                             /*DisableValidation=*/false,
+                             /*DisableStatCache=*/false,
+                             AllowPCHWithCompilerErrors));
+  
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<ASTReader>
+    ReaderCleanup(Reader.get());
+
+  Reader->setListener(new ASTInfoCollector(*AST->PP, Context,
+                                           AST->ASTFileLangOpts, HeaderInfo, 
+                                           AST->Target, Predefines, Counter));
+
+  switch (Reader->ReadAST(Filename, serialization::MK_MainFile)) {
+  case ASTReader::Success:
+    break;
+
+  case ASTReader::Failure:
+  case ASTReader::IgnorePCH:
+    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
+    return NULL;
+  }
+
+  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
+
+  PP.setPredefines(Reader->getSuggestedPredefines());
+  PP.setCounterValue(Counter);
+
+  // Attach the AST reader to the AST context as an external AST
+  // source, so that declarations will be deserialized from the
+  // AST file as needed.
+  ASTReader *ReaderPtr = Reader.get();
+  OwningPtr<ExternalASTSource> Source(Reader.take());
+
+  // Unregister the cleanup for ASTReader.  It will get cleaned up
+  // by the ASTUnit cleanup.
+  ReaderCleanup.unregister();
+
+  Context.setExternalSource(Source);
+
+  // Create an AST consumer, even though it isn't used.
+  AST->Consumer.reset(new ASTConsumer);
+  
+  // Create a semantic analysis object and tell the AST reader about it.
+  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
+  AST->TheSema->Initialize();
+  ReaderPtr->InitializeSema(*AST->TheSema);
+  AST->Reader = ReaderPtr;
+
+  return AST.take();
+}
+
+namespace {
+
+/// \brief Preprocessor callback class that updates a hash value with the names 
+/// of all macros that have been defined by the translation unit.
+class MacroDefinitionTrackerPPCallbacks : public PPCallbacks {
+  unsigned &Hash;
+  
+public:
+  explicit MacroDefinitionTrackerPPCallbacks(unsigned &Hash) : Hash(Hash) { }
+  
+  virtual void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI) {
+    Hash = llvm::HashString(MacroNameTok.getIdentifierInfo()->getName(), Hash);
+  }
+};
+
+/// \brief Add the given declaration to the hash of all top-level entities.
+void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
+  if (!D)
+    return;
+  
+  DeclContext *DC = D->getDeclContext();
+  if (!DC)
+    return;
+  
+  if (!(DC->isTranslationUnit() || DC->getLookupParent()->isTranslationUnit()))
+    return;
+
+  if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
+    if (ND->getIdentifier())
+      Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
+    else if (DeclarationName Name = ND->getDeclName()) {
+      std::string NameStr = Name.getAsString();
+      Hash = llvm::HashString(NameStr, Hash);
+    }
+    return;
+  }  
+}
+
+class TopLevelDeclTrackerConsumer : public ASTConsumer {
+  ASTUnit &Unit;
+  unsigned &Hash;
+  
+public:
+  TopLevelDeclTrackerConsumer(ASTUnit &_Unit, unsigned &Hash)
+    : Unit(_Unit), Hash(Hash) {
+    Hash = 0;
+  }
+
+  void handleTopLevelDecl(Decl *D) {
+    if (!D)
+      return;
+
+    // FIXME: Currently ObjC method declarations are incorrectly being
+    // reported as top-level declarations, even though their DeclContext
+    // is the containing ObjC @interface/@implementation.  This is a
+    // fundamental problem in the parser right now.
+    if (isa<ObjCMethodDecl>(D))
+      return;
+
+    AddTopLevelDeclarationToHash(D, Hash);
+    Unit.addTopLevelDecl(D);
+
+    handleFileLevelDecl(D);
+  }
+
+  void handleFileLevelDecl(Decl *D) {
+    Unit.addFileLevelDecl(D);
+    if (NamespaceDecl *NSD = dyn_cast<NamespaceDecl>(D)) {
+      for (NamespaceDecl::decl_iterator
+             I = NSD->decls_begin(), E = NSD->decls_end(); I != E; ++I)
+        handleFileLevelDecl(*I);
+    }
+  }
+
+  bool HandleTopLevelDecl(DeclGroupRef D) {
+    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it)
+      handleTopLevelDecl(*it);
+    return true;
+  }
+
+  // We're not interested in "interesting" decls.
+  void HandleInterestingDecl(DeclGroupRef) {}
+
+  void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) {
+    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it)
+      handleTopLevelDecl(*it);
+  }
+};
+
+class TopLevelDeclTrackerAction : public ASTFrontendAction {
+public:
+  ASTUnit &Unit;
+
+  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
+                                         StringRef InFile) {
+    CI.getPreprocessor().addPPCallbacks(
+     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
+    return new TopLevelDeclTrackerConsumer(Unit, 
+                                           Unit.getCurrentTopLevelHashValue());
+  }
+
+public:
+  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
+
+  virtual bool hasCodeCompletionSupport() const { return false; }
+  virtual TranslationUnitKind getTranslationUnitKind()  { 
+    return Unit.getTranslationUnitKind(); 
+  }
+};
+
+class PrecompilePreambleConsumer : public PCHGenerator {
+  ASTUnit &Unit;
+  unsigned &Hash;                                   
+  std::vector<Decl *> TopLevelDecls;
+                                     
+public:
+  PrecompilePreambleConsumer(ASTUnit &Unit, const Preprocessor &PP, 
+                             StringRef isysroot, raw_ostream *Out)
+    : PCHGenerator(PP, "", 0, isysroot, Out), Unit(Unit),
+      Hash(Unit.getCurrentTopLevelHashValue()) {
+    Hash = 0;
+  }
+
+  virtual bool HandleTopLevelDecl(DeclGroupRef D) {
+    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
+      Decl *D = *it;
+      // FIXME: Currently ObjC method declarations are incorrectly being
+      // reported as top-level declarations, even though their DeclContext
+      // is the containing ObjC @interface/@implementation.  This is a
+      // fundamental problem in the parser right now.
+      if (isa<ObjCMethodDecl>(D))
+        continue;
+      AddTopLevelDeclarationToHash(D, Hash);
+      TopLevelDecls.push_back(D);
+    }
+    return true;
+  }
+
+  virtual void HandleTranslationUnit(ASTContext &Ctx) {
+    PCHGenerator::HandleTranslationUnit(Ctx);
+    if (!Unit.getDiagnostics().hasErrorOccurred()) {
+      // Translate the top-level declarations we captured during
+      // parsing into declaration IDs in the precompiled
+      // preamble. This will allow us to deserialize those top-level
+      // declarations when requested.
+      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
+        Unit.addTopLevelDeclFromPreamble(
+                                      getWriter().getDeclID(TopLevelDecls[I]));
+    }
+  }
+};
+
+class PrecompilePreambleAction : public ASTFrontendAction {
+  ASTUnit &Unit;
+
+public:
+  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
+
+  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
+                                         StringRef InFile) {
+    std::string Sysroot;
+    std::string OutputFile;
+    raw_ostream *OS = 0;
+    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
+                                                       OutputFile,
+                                                       OS))
+      return 0;
+    
+    if (!CI.getFrontendOpts().RelocatablePCH)
+      Sysroot.clear();
+
+    CI.getPreprocessor().addPPCallbacks(
+     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
+    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Sysroot, 
+                                          OS);
+  }
+
+  virtual bool hasCodeCompletionSupport() const { return false; }
+  virtual bool hasASTFileSupport() const { return false; }
+  virtual TranslationUnitKind getTranslationUnitKind() { return TU_Prefix; }
+};
+
+}
+
+static void checkAndRemoveNonDriverDiags(SmallVectorImpl<StoredDiagnostic> &
+                                                            StoredDiagnostics) {
+  // Get rid of stored diagnostics except the ones from the driver which do not
+  // have a source location.
+  for (unsigned I = 0; I < StoredDiagnostics.size(); ++I) {
+    if (StoredDiagnostics[I].getLocation().isValid()) {
+      StoredDiagnostics.erase(StoredDiagnostics.begin()+I);
+      --I;
+    }
+  }
+}
+
+static void checkAndSanitizeDiags(SmallVectorImpl<StoredDiagnostic> &
+                                                              StoredDiagnostics,
+                                  SourceManager &SM) {
+  // The stored diagnostic has the old source manager in it; update
+  // the locations to refer into the new source manager. Since we've
+  // been careful to make sure that the source manager's state
+  // before and after are identical, so that we can reuse the source
+  // location itself.
+  for (unsigned I = 0, N = StoredDiagnostics.size(); I < N; ++I) {
+    if (StoredDiagnostics[I].getLocation().isValid()) {
+      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SM);
+      StoredDiagnostics[I].setLocation(Loc);
+    }
+  }
+}
+
+/// Parse the source file into a translation unit using the given compiler
+/// invocation, replacing the current translation unit.
+///
+/// \returns True if a failure occurred that causes the ASTUnit not to
+/// contain any translation-unit information, false otherwise.
+bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
+  delete SavedMainFileBuffer;
+  SavedMainFileBuffer = 0;
+  
+  if (!Invocation) {
+    delete OverrideMainBuffer;
+    return true;
+  }
+  
+  // Create the compiler instance to use for building the AST.
+  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
+    CICleanup(Clang.get());
+
+  IntrusiveRefCntPtr<CompilerInvocation>
+    CCInvocation(new CompilerInvocation(*Invocation));
+
+  Clang->setInvocation(CCInvocation.getPtr());
+  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
+    
+  // Set up diagnostics, capturing any diagnostics that would
+  // otherwise be dropped.
+  Clang->setDiagnostics(&getDiagnostics());
+  
+  // Create the target instance.
+  Clang->getTargetOpts().Features = TargetFeatures;
+  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
+                   Clang->getTargetOpts()));
+  if (!Clang->hasTarget()) {
+    delete OverrideMainBuffer;
+    return true;
+  }
+
+  // Inform the target of the language options.
+  //
+  // FIXME: We shouldn't need to do this, the target should be immutable once
+  // created. This complexity should be lifted elsewhere.
+  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
+  
+  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
+         "Invocation must have exactly one source file!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
+         "FIXME: AST inputs not yet supported here!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
+         "IR inputs not support here!");
+
+  // Configure the various subsystems.
+  // FIXME: Should we retain the previous file manager?
+  LangOpts = &Clang->getLangOpts();
+  FileSystemOpts = Clang->getFileSystemOpts();
+  FileMgr = new FileManager(FileSystemOpts);
+  SourceMgr = new SourceManager(getDiagnostics(), *FileMgr);
+  TheSema.reset();
+  Ctx = 0;
+  PP = 0;
+  Reader = 0;
+  
+  // Clear out old caches and data.
+  TopLevelDecls.clear();
+  clearFileLevelDecls();
+  CleanTemporaryFiles();
+
+  if (!OverrideMainBuffer) {
+    checkAndRemoveNonDriverDiags(StoredDiagnostics);
+    TopLevelDeclsInPreamble.clear();
+  }
+
+  // Create a file manager object to provide access to and cache the filesystem.
+  Clang->setFileManager(&getFileManager());
+  
+  // Create the source manager.
+  Clang->setSourceManager(&getSourceManager());
+  
+  // If the main file has been overridden due to the use of a preamble,
+  // make that override happen and introduce the preamble.
+  PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
+  if (OverrideMainBuffer) {
+    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
+    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
+    PreprocessorOpts.PrecompiledPreambleBytes.second
+                                                    = PreambleEndsAtStartOfLine;
+    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
+    PreprocessorOpts.DisablePCHValidation = true;
+    
+    // The stored diagnostic has the old source manager in it; update
+    // the locations to refer into the new source manager. Since we've
+    // been careful to make sure that the source manager's state
+    // before and after are identical, so that we can reuse the source
+    // location itself.
+    checkAndSanitizeDiags(StoredDiagnostics, getSourceManager());
+
+    // Keep track of the override buffer;
+    SavedMainFileBuffer = OverrideMainBuffer;
+  }
+  
+  OwningPtr<TopLevelDeclTrackerAction> Act(
+    new TopLevelDeclTrackerAction(*this));
+    
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
+    ActCleanup(Act.get());
+
+  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))
+    goto error;
+
+  if (OverrideMainBuffer) {
+    std::string ModName = getPreambleFile(this);
+    TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
+                               getSourceManager(), PreambleDiagnostics,
+                               StoredDiagnostics);
+  }
+
+  Act->Execute();
+
+  transferASTDataFromCompilerInstance(*Clang);
+  
+  Act->EndSourceFile();
+
+  FailedParseDiagnostics.clear();
+
+  return false;
+
+error:
+  // Remove the overridden buffer we used for the preamble.
+  if (OverrideMainBuffer) {
+    delete OverrideMainBuffer;
+    SavedMainFileBuffer = 0;
+  }
+
+  // Keep the ownership of the data in the ASTUnit because the client may
+  // want to see the diagnostics.
+  transferASTDataFromCompilerInstance(*Clang);
+  FailedParseDiagnostics.swap(StoredDiagnostics);
+  StoredDiagnostics.clear();
+  NumStoredDiagnosticsFromDriver = 0;
+  return true;
+}
+
+/// \brief Simple function to retrieve a path for a preamble precompiled header.
+static std::string GetPreamblePCHPath() {
+  // FIXME: This is lame; sys::Path should provide this function (in particular,
+  // it should know how to find the temporary files dir).
+  // FIXME: This is really lame. I copied this code from the Driver!
+  // FIXME: This is a hack so that we can override the preamble file during
+  // crash-recovery testing, which is the only case where the preamble files
+  // are not necessarily cleaned up. 
+  const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
+  if (TmpFile)
+    return TmpFile;
+  
+  std::string Error;
+  const char *TmpDir = ::getenv("TMPDIR");
+  if (!TmpDir)
+    TmpDir = ::getenv("TEMP");
+  if (!TmpDir)
+    TmpDir = ::getenv("TMP");
+#ifdef LLVM_ON_WIN32
+  if (!TmpDir)
+    TmpDir = ::getenv("USERPROFILE");
+#endif
+  if (!TmpDir)
+    TmpDir = "/tmp";
+  llvm::sys::Path P(TmpDir);
+  P.createDirectoryOnDisk(true);
+  P.appendComponent("preamble");
+  P.appendSuffix("pch");
+  if (P.makeUnique(/*reuse_current=*/false, /*ErrMsg*/0))
+    return std::string();
+  
+  return P.str();
+}
+
+/// \brief Compute the preamble for the main file, providing the source buffer
+/// that corresponds to the main file along with a pair (bytes, start-of-line)
+/// that describes the preamble.
+std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > 
+ASTUnit::ComputePreamble(CompilerInvocation &Invocation, 
+                         unsigned MaxLines, bool &CreatedBuffer) {
+  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
+  PreprocessorOptions &PreprocessorOpts = Invocation.getPreprocessorOpts();
+  CreatedBuffer = false;
+  
+  // Try to determine if the main file has been remapped, either from the 
+  // command line (to another file) or directly through the compiler invocation
+  // (to a memory buffer).
+  llvm::MemoryBuffer *Buffer = 0;
+  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].File);
+  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
+    // Check whether there is a file-file remapping of the main file
+    for (PreprocessorOptions::remapped_file_iterator
+          M = PreprocessorOpts.remapped_file_begin(),
+          E = PreprocessorOpts.remapped_file_end();
+         M != E;
+         ++M) {
+      llvm::sys::PathWithStatus MPath(M->first);    
+      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
+        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
+          // We found a remapping. Try to load the resulting, remapped source.
+          if (CreatedBuffer) {
+            delete Buffer;
+            CreatedBuffer = false;
+          }
+          
+          Buffer = getBufferForFile(M->second);
+          if (!Buffer)
+            return std::make_pair((llvm::MemoryBuffer*)0, 
+                                  std::make_pair(0, true));
+          CreatedBuffer = true;
+        }
+      }
+    }
+    
+    // Check whether there is a file-buffer remapping. It supercedes the
+    // file-file remapping.
+    for (PreprocessorOptions::remapped_file_buffer_iterator
+           M = PreprocessorOpts.remapped_file_buffer_begin(),
+           E = PreprocessorOpts.remapped_file_buffer_end();
+         M != E;
+         ++M) {
+      llvm::sys::PathWithStatus MPath(M->first);    
+      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
+        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
+          // We found a remapping. 
+          if (CreatedBuffer) {
+            delete Buffer;
+            CreatedBuffer = false;
+          }
+          
+          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
+        }
+      }
+    }
+  }
+  
+  // If the main source file was not remapped, load it now.
+  if (!Buffer) {
+    Buffer = getBufferForFile(FrontendOpts.Inputs[0].File);
+    if (!Buffer)
+      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));    
+    
+    CreatedBuffer = true;
+  }
+  
+  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer,
+                                                       *Invocation.getLangOpts(),
+                                                       MaxLines));
+}
+
+static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
+                                                      unsigned NewSize,
+                                                      StringRef NewName) {
+  llvm::MemoryBuffer *Result
+    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
+  memcpy(const_cast<char*>(Result->getBufferStart()), 
+         Old->getBufferStart(), Old->getBufferSize());
+  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(), 
+         ' ', NewSize - Old->getBufferSize() - 1);
+  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';  
+  
+  return Result;
+}
+
+/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
+/// the source file.
+///
+/// This routine will compute the preamble of the main source file. If a
+/// non-trivial preamble is found, it will precompile that preamble into a 
+/// precompiled header so that the precompiled preamble can be used to reduce
+/// reparsing time. If a precompiled preamble has already been constructed,
+/// this routine will determine if it is still valid and, if so, avoid 
+/// rebuilding the precompiled preamble.
+///
+/// \param AllowRebuild When true (the default), this routine is
+/// allowed to rebuild the precompiled preamble if it is found to be
+/// out-of-date.
+///
+/// \param MaxLines When non-zero, the maximum number of lines that
+/// can occur within the preamble.
+///
+/// \returns If the precompiled preamble can be used, returns a newly-allocated
+/// buffer that should be used in place of the main file when doing so.
+/// Otherwise, returns a NULL pointer.
+llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
+                              const CompilerInvocation &PreambleInvocationIn,
+                                                           bool AllowRebuild,
+                                                           unsigned MaxLines) {
+  
+  IntrusiveRefCntPtr<CompilerInvocation>
+    PreambleInvocation(new CompilerInvocation(PreambleInvocationIn));
+  FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();
+  PreprocessorOptions &PreprocessorOpts
+    = PreambleInvocation->getPreprocessorOpts();
+
+  bool CreatedPreambleBuffer = false;
+  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble 
+    = ComputePreamble(*PreambleInvocation, MaxLines, CreatedPreambleBuffer);
+
+  // If ComputePreamble() Take ownership of the preamble buffer.
+  OwningPtr<llvm::MemoryBuffer> OwnedPreambleBuffer;
+  if (CreatedPreambleBuffer)
+    OwnedPreambleBuffer.reset(NewPreamble.first);
+
+  if (!NewPreamble.second.first) {
+    // We couldn't find a preamble in the main source. Clear out the current
+    // preamble, if we have one. It's obviously no good any more.
+    Preamble.clear();
+    erasePreambleFile(this);
+
+    // The next time we actually see a preamble, precompile it.
+    PreambleRebuildCounter = 1;
+    return 0;
+  }
+  
+  if (!Preamble.empty()) {
+    // We've previously computed a preamble. Check whether we have the same
+    // preamble now that we did before, and that there's enough space in
+    // the main-file buffer within the precompiled preamble to fit the
+    // new main file.
+    if (Preamble.size() == NewPreamble.second.first &&
+        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
+        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
+        memcmp(Preamble.getBufferStart(), NewPreamble.first->getBufferStart(),
+               NewPreamble.second.first) == 0) {
+      // The preamble has not changed. We may be able to re-use the precompiled
+      // preamble.
+
+      // Check that none of the files used by the preamble have changed.
+      bool AnyFileChanged = false;
+          
+      // First, make a record of those files that have been overridden via
+      // remapping or unsaved_files.
+      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
+      for (PreprocessorOptions::remapped_file_iterator
+                R = PreprocessorOpts.remapped_file_begin(),
+             REnd = PreprocessorOpts.remapped_file_end();
+           !AnyFileChanged && R != REnd;
+           ++R) {
+        struct stat StatBuf;
+        if (FileMgr->getNoncachedStatValue(R->second, StatBuf)) {
+          // If we can't stat the file we're remapping to, assume that something
+          // horrible happened.
+          AnyFileChanged = true;
+          break;
+        }
+        
+        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size, 
+                                                   StatBuf.st_mtime);
+      }
+      for (PreprocessorOptions::remapped_file_buffer_iterator
+                R = PreprocessorOpts.remapped_file_buffer_begin(),
+             REnd = PreprocessorOpts.remapped_file_buffer_end();
+           !AnyFileChanged && R != REnd;
+           ++R) {
+        // FIXME: Should we actually compare the contents of file->buffer
+        // remappings?
+        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(), 
+                                                   0);
+      }
+       
+      // Check whether anything has changed.
+      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator 
+             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
+           !AnyFileChanged && F != FEnd; 
+           ++F) {
+        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
+          = OverriddenFiles.find(F->first());
+        if (Overridden != OverriddenFiles.end()) {
+          // This file was remapped; check whether the newly-mapped file 
+          // matches up with the previous mapping.
+          if (Overridden->second != F->second)
+            AnyFileChanged = true;
+          continue;
+        }
+        
+        // The file was not remapped; check whether it has changed on disk.
+        struct stat StatBuf;
+        if (FileMgr->getNoncachedStatValue(F->first(), StatBuf)) {
+          // If we can't stat the file, assume that something horrible happened.
+          AnyFileChanged = true;
+        } else if (StatBuf.st_size != F->second.first || 
+                   StatBuf.st_mtime != F->second.second)
+          AnyFileChanged = true;
+      }
+          
+      if (!AnyFileChanged) {
+        // Okay! We can re-use the precompiled preamble.
+
+        // Set the state of the diagnostic object to mimic its state
+        // after parsing the preamble.
+        getDiagnostics().Reset();
+        ProcessWarningOptions(getDiagnostics(), 
+                              PreambleInvocation->getDiagnosticOpts());
+        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
+
+        // Create a version of the main file buffer that is padded to
+        // buffer size we reserved when creating the preamble.
+        return CreatePaddedMainFileBuffer(NewPreamble.first, 
+                                          PreambleReservedSize,
+                                          FrontendOpts.Inputs[0].File);
+      }
+    }
+
+    // If we aren't allowed to rebuild the precompiled preamble, just
+    // return now.
+    if (!AllowRebuild)
+      return 0;
+
+    // We can't reuse the previously-computed preamble. Build a new one.
+    Preamble.clear();
+    PreambleDiagnostics.clear();
+    erasePreambleFile(this);
+    PreambleRebuildCounter = 1;
+  } else if (!AllowRebuild) {
+    // We aren't allowed to rebuild the precompiled preamble; just
+    // return now.
+    return 0;
+  }
+
+  // If the preamble rebuild counter > 1, it's because we previously
+  // failed to build a preamble and we're not yet ready to try
+  // again. Decrement the counter and return a failure.
+  if (PreambleRebuildCounter > 1) {
+    --PreambleRebuildCounter;
+    return 0;
+  }
+
+  // Create a temporary file for the precompiled preamble. In rare 
+  // circumstances, this can fail.
+  std::string PreamblePCHPath = GetPreamblePCHPath();
+  if (PreamblePCHPath.empty()) {
+    // Try again next time.
+    PreambleRebuildCounter = 1;
+    return 0;
+  }
+  
+  // We did not previously compute a preamble, or it can't be reused anyway.
+  SimpleTimer PreambleTimer(WantTiming);
+  PreambleTimer.setOutput("Precompiling preamble");
+  
+  // Create a new buffer that stores the preamble. The buffer also contains
+  // extra space for the original contents of the file (which will be present
+  // when we actually parse the file) along with more room in case the file
+  // grows.  
+  PreambleReservedSize = NewPreamble.first->getBufferSize();
+  if (PreambleReservedSize < 4096)
+    PreambleReservedSize = 8191;
+  else
+    PreambleReservedSize *= 2;
+
+  // Save the preamble text for later; we'll need to compare against it for
+  // subsequent reparses.
+  StringRef MainFilename = PreambleInvocation->getFrontendOpts().Inputs[0].File;
+  Preamble.assign(FileMgr->getFile(MainFilename),
+                  NewPreamble.first->getBufferStart(), 
+                  NewPreamble.first->getBufferStart() 
+                                                  + NewPreamble.second.first);
+  PreambleEndsAtStartOfLine = NewPreamble.second.second;
+
+  delete PreambleBuffer;
+  PreambleBuffer
+    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
+                                                FrontendOpts.Inputs[0].File);
+  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()), 
+         NewPreamble.first->getBufferStart(), Preamble.size());
+  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(), 
+         ' ', PreambleReservedSize - Preamble.size() - 1);
+  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';  
+  
+  // Remap the main source file to the preamble buffer.
+  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].File);
+  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
+  
+  // Tell the compiler invocation to generate a temporary precompiled header.
+  FrontendOpts.ProgramAction = frontend::GeneratePCH;
+  // FIXME: Generate the precompiled header into memory?
+  FrontendOpts.OutputFile = PreamblePCHPath;
+  PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
+  PreprocessorOpts.PrecompiledPreambleBytes.second = false;
+  
+  // Create the compiler instance to use for building the precompiled preamble.
+  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
+    CICleanup(Clang.get());
+
+  Clang->setInvocation(&*PreambleInvocation);
+  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
+  
+  // Set up diagnostics, capturing all of the diagnostics produced.
+  Clang->setDiagnostics(&getDiagnostics());
+  
+  // Create the target instance.
+  Clang->getTargetOpts().Features = TargetFeatures;
+  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
+                                               Clang->getTargetOpts()));
+  if (!Clang->hasTarget()) {
+    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
+    Preamble.clear();
+    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
+    PreprocessorOpts.eraseRemappedFile(
+                               PreprocessorOpts.remapped_file_buffer_end() - 1);
+    return 0;
+  }
+  
+  // Inform the target of the language options.
+  //
+  // FIXME: We shouldn't need to do this, the target should be immutable once
+  // created. This complexity should be lifted elsewhere.
+  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
+  
+  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
+         "Invocation must have exactly one source file!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
+         "FIXME: AST inputs not yet supported here!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
+         "IR inputs not support here!");
+  
+  // Clear out old caches and data.
+  getDiagnostics().Reset();
+  ProcessWarningOptions(getDiagnostics(), Clang->getDiagnosticOpts());
+  checkAndRemoveNonDriverDiags(StoredDiagnostics);
+  TopLevelDecls.clear();
+  TopLevelDeclsInPreamble.clear();
+  
+  // Create a file manager object to provide access to and cache the filesystem.
+  Clang->setFileManager(new FileManager(Clang->getFileSystemOpts()));
+  
+  // Create the source manager.
+  Clang->setSourceManager(new SourceManager(getDiagnostics(),
+                                            Clang->getFileManager()));
+  
+  OwningPtr<PrecompilePreambleAction> Act;
+  Act.reset(new PrecompilePreambleAction(*this));
+  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
+    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
+    Preamble.clear();
+    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
+    PreprocessorOpts.eraseRemappedFile(
+                               PreprocessorOpts.remapped_file_buffer_end() - 1);
+    return 0;
+  }
+  
+  Act->Execute();
+  Act->EndSourceFile();
+
+  if (Diagnostics->hasErrorOccurred()) {
+    // There were errors parsing the preamble, so no precompiled header was
+    // generated. Forget that we even tried.
+    // FIXME: Should we leave a note for ourselves to try again?
+    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
+    Preamble.clear();
+    TopLevelDeclsInPreamble.clear();
+    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
+    PreprocessorOpts.eraseRemappedFile(
+                               PreprocessorOpts.remapped_file_buffer_end() - 1);
+    return 0;
+  }
+  
+  // Transfer any diagnostics generated when parsing the preamble into the set
+  // of preamble diagnostics.
+  PreambleDiagnostics.clear();
+  PreambleDiagnostics.insert(PreambleDiagnostics.end(), 
+                            stored_diag_afterDriver_begin(), stored_diag_end());
+  checkAndRemoveNonDriverDiags(StoredDiagnostics);
+  
+  // Keep track of the preamble we precompiled.
+  setPreambleFile(this, FrontendOpts.OutputFile);
+  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
+  
+  // Keep track of all of the files that the source manager knows about,
+  // so we can verify whether they have changed or not.
+  FilesInPreamble.clear();
+  SourceManager &SourceMgr = Clang->getSourceManager();
+  const llvm::MemoryBuffer *MainFileBuffer
+    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
+  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
+                                     FEnd = SourceMgr.fileinfo_end();
+       F != FEnd;
+       ++F) {
+    const FileEntry *File = F->second->OrigEntry;
+    if (!File || F->second->getRawBuffer() == MainFileBuffer)
+      continue;
+    
+    FilesInPreamble[File->getName()]
+      = std::make_pair(F->second->getSize(), File->getModificationTime());
+  }
+  
+  PreambleRebuildCounter = 1;
+  PreprocessorOpts.eraseRemappedFile(
+                               PreprocessorOpts.remapped_file_buffer_end() - 1);
+  
+  // If the hash of top-level entities differs from the hash of the top-level
+  // entities the last time we rebuilt the preamble, clear out the completion
+  // cache.
+  if (CurrentTopLevelHashValue != PreambleTopLevelHashValue) {
+    CompletionCacheTopLevelHashValue = 0;
+    PreambleTopLevelHashValue = CurrentTopLevelHashValue;
+  }
+  
+  return CreatePaddedMainFileBuffer(NewPreamble.first, 
+                                    PreambleReservedSize,
+                                    FrontendOpts.Inputs[0].File);
+}
+
+void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
+  std::vector<Decl *> Resolved;
+  Resolved.reserve(TopLevelDeclsInPreamble.size());
+  ExternalASTSource &Source = *getASTContext().getExternalSource();
+  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
+    // Resolve the declaration ID to an actual declaration, possibly
+    // deserializing the declaration in the process.
+    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
+    if (D)
+      Resolved.push_back(D);
+  }
+  TopLevelDeclsInPreamble.clear();
+  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
+}
+
+void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
+  // Steal the created target, context, and preprocessor.
+  TheSema.reset(CI.takeSema());
+  Consumer.reset(CI.takeASTConsumer());
+  Ctx = &CI.getASTContext();
+  PP = &CI.getPreprocessor();
+  CI.setSourceManager(0);
+  CI.setFileManager(0);
+  Target = &CI.getTarget();
+  Reader = CI.getModuleManager();
+}
+
+StringRef ASTUnit::getMainFileName() const {
+  return Invocation->getFrontendOpts().Inputs[0].File;
+}
+
+ASTUnit *ASTUnit::create(CompilerInvocation *CI,
+                         IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                         bool CaptureDiagnostics) {
+  OwningPtr<ASTUnit> AST;
+  AST.reset(new ASTUnit(false));
+  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
+  AST->Diagnostics = Diags;
+  AST->Invocation = CI;
+  AST->FileSystemOpts = CI->getFileSystemOpts();
+  AST->FileMgr = new FileManager(AST->FileSystemOpts);
+  AST->SourceMgr = new SourceManager(AST->getDiagnostics(), *AST->FileMgr);
+
+  return AST.take();
+}
+
+ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(CompilerInvocation *CI,
+                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                                             ASTFrontendAction *Action,
+                                             ASTUnit *Unit,
+                                             bool Persistent,
+                                             StringRef ResourceFilesPath,
+                                             bool OnlyLocalDecls,
+                                             bool CaptureDiagnostics,
+                                             bool PrecompilePreamble,
+                                             bool CacheCodeCompletionResults,
+                                             OwningPtr<ASTUnit> *ErrAST) {
+  assert(CI && "A CompilerInvocation is required");
+
+  OwningPtr<ASTUnit> OwnAST;
+  ASTUnit *AST = Unit;
+  if (!AST) {
+    // Create the AST unit.
+    OwnAST.reset(create(CI, Diags, CaptureDiagnostics));
+    AST = OwnAST.get();
+  }
+  
+  if (!ResourceFilesPath.empty()) {
+    // Override the resources path.
+    CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
+  }
+  AST->OnlyLocalDecls = OnlyLocalDecls;
+  AST->CaptureDiagnostics = CaptureDiagnostics;
+  if (PrecompilePreamble)
+    AST->PreambleRebuildCounter = 2;
+  AST->TUKind = Action ? Action->getTranslationUnitKind() : TU_Complete;
+  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
+    ASTUnitCleanup(OwnAST.get());
+  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
+    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
+    DiagCleanup(Diags.getPtr());
+
+  // We'll manage file buffers ourselves.
+  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
+  CI->getFrontendOpts().DisableFree = false;
+  ProcessWarningOptions(AST->getDiagnostics(), CI->getDiagnosticOpts());
+
+  // Save the target features.
+  AST->TargetFeatures = CI->getTargetOpts().Features;
+
+  // Create the compiler instance to use for building the AST.
+  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
+    CICleanup(Clang.get());
+
+  Clang->setInvocation(CI);
+  AST->OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
+    
+  // Set up diagnostics, capturing any diagnostics that would
+  // otherwise be dropped.
+  Clang->setDiagnostics(&AST->getDiagnostics());
+  
+  // Create the target instance.
+  Clang->getTargetOpts().Features = AST->TargetFeatures;
+  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
+                   Clang->getTargetOpts()));
+  if (!Clang->hasTarget())
+    return 0;
+
+  // Inform the target of the language options.
+  //
+  // FIXME: We shouldn't need to do this, the target should be immutable once
+  // created. This complexity should be lifted elsewhere.
+  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
+  
+  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
+         "Invocation must have exactly one source file!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
+         "FIXME: AST inputs not yet supported here!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
+         "IR inputs not supported here!");
+
+  // Configure the various subsystems.
+  AST->TheSema.reset();
+  AST->Ctx = 0;
+  AST->PP = 0;
+  AST->Reader = 0;
+  
+  // Create a file manager object to provide access to and cache the filesystem.
+  Clang->setFileManager(&AST->getFileManager());
+  
+  // Create the source manager.
+  Clang->setSourceManager(&AST->getSourceManager());
+
+  ASTFrontendAction *Act = Action;
+
+  OwningPtr<TopLevelDeclTrackerAction> TrackerAct;
+  if (!Act) {
+    TrackerAct.reset(new TopLevelDeclTrackerAction(*AST));
+    Act = TrackerAct.get();
+  }
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
+    ActCleanup(TrackerAct.get());
+
+  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
+    AST->transferASTDataFromCompilerInstance(*Clang);
+    if (OwnAST && ErrAST)
+      ErrAST->swap(OwnAST);
+
+    return 0;
+  }
+
+  if (Persistent && !TrackerAct) {
+    Clang->getPreprocessor().addPPCallbacks(
+     new MacroDefinitionTrackerPPCallbacks(AST->getCurrentTopLevelHashValue()));
+    std::vector<ASTConsumer*> Consumers;
+    if (Clang->hasASTConsumer())
+      Consumers.push_back(Clang->takeASTConsumer());
+    Consumers.push_back(new TopLevelDeclTrackerConsumer(*AST,
+                                           AST->getCurrentTopLevelHashValue()));
+    Clang->setASTConsumer(new MultiplexConsumer(Consumers));
+  }
+  Act->Execute();
+
+  // Steal the created target, context, and preprocessor.
+  AST->transferASTDataFromCompilerInstance(*Clang);
+  
+  Act->EndSourceFile();
+
+  if (OwnAST)
+    return OwnAST.take();
+  else
+    return AST;
+}
+
+bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
+  if (!Invocation)
+    return true;
+  
+  // We'll manage file buffers ourselves.
+  Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
+  Invocation->getFrontendOpts().DisableFree = false;
+  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
+
+  // Save the target features.
+  TargetFeatures = Invocation->getTargetOpts().Features;
+  
+  llvm::MemoryBuffer *OverrideMainBuffer = 0;
+  if (PrecompilePreamble) {
+    PreambleRebuildCounter = 2;
+    OverrideMainBuffer
+      = getMainBufferWithPrecompiledPreamble(*Invocation);
+  }
+  
+  SimpleTimer ParsingTimer(WantTiming);
+  ParsingTimer.setOutput("Parsing " + getMainFileName());
+  
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<llvm::MemoryBuffer>
+    MemBufferCleanup(OverrideMainBuffer);
+  
+  return Parse(OverrideMainBuffer);
+}
+
+ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
+                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                                             bool OnlyLocalDecls,
+                                             bool CaptureDiagnostics,
+                                             bool PrecompilePreamble,
+                                             TranslationUnitKind TUKind,
+                                             bool CacheCodeCompletionResults) {  
+  // Create the AST unit.
+  OwningPtr<ASTUnit> AST;
+  AST.reset(new ASTUnit(false));
+  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
+  AST->Diagnostics = Diags;
+  AST->OnlyLocalDecls = OnlyLocalDecls;
+  AST->CaptureDiagnostics = CaptureDiagnostics;
+  AST->TUKind = TUKind;
+  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
+  AST->Invocation = CI;
+  
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
+    ASTUnitCleanup(AST.get());
+  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
+    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
+    DiagCleanup(Diags.getPtr());
+
+  return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
+}
+
+ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
+                                      const char **ArgEnd,
+                                    IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                                      StringRef ResourceFilesPath,
+                                      bool OnlyLocalDecls,
+                                      bool CaptureDiagnostics,
+                                      RemappedFile *RemappedFiles,
+                                      unsigned NumRemappedFiles,
+                                      bool RemappedFilesKeepOriginalName,
+                                      bool PrecompilePreamble,
+                                      TranslationUnitKind TUKind,
+                                      bool CacheCodeCompletionResults,
+                                      bool AllowPCHWithCompilerErrors,
+                                      bool SkipFunctionBodies,
+                                      OwningPtr<ASTUnit> *ErrAST) {
+  if (!Diags.getPtr()) {
+    // No diagnostics engine was provided, so create our own diagnostics object
+    // with the default options.
+    DiagnosticOptions DiagOpts;
+    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd - ArgBegin, 
+                                                ArgBegin);
+  }
+
+  SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
+  
+  IntrusiveRefCntPtr<CompilerInvocation> CI;
+
+  {
+
+    CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags, 
+                                      StoredDiagnostics);
+
+    CI = clang::createInvocationFromCommandLine(
+                                           llvm::makeArrayRef(ArgBegin, ArgEnd),
+                                           Diags);
+    if (!CI)
+      return 0;
+  }
+
+  // Override any files that need remapping
+  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
+    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
+    if (const llvm::MemoryBuffer *
+            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
+      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, memBuf);
+    } else {
+      const char *fname = fileOrBuf.get<const char *>();
+      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, fname);
+    }
+  }
+  PreprocessorOptions &PPOpts = CI->getPreprocessorOpts();
+  PPOpts.RemappedFilesKeepOriginalName = RemappedFilesKeepOriginalName;
+  PPOpts.AllowPCHWithCompilerErrors = AllowPCHWithCompilerErrors;
+  
+  // Override the resources path.
+  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
+
+  CI->getFrontendOpts().SkipFunctionBodies = SkipFunctionBodies;
+
+  // Create the AST unit.
+  OwningPtr<ASTUnit> AST;
+  AST.reset(new ASTUnit(false));
+  ConfigureDiags(Diags, ArgBegin, ArgEnd, *AST, CaptureDiagnostics);
+  AST->Diagnostics = Diags;
+  Diags = 0; // Zero out now to ease cleanup during crash recovery.
+  AST->FileSystemOpts = CI->getFileSystemOpts();
+  AST->FileMgr = new FileManager(AST->FileSystemOpts);
+  AST->OnlyLocalDecls = OnlyLocalDecls;
+  AST->CaptureDiagnostics = CaptureDiagnostics;
+  AST->TUKind = TUKind;
+  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
+  AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
+  AST->StoredDiagnostics.swap(StoredDiagnostics);
+  AST->Invocation = CI;
+  CI = 0; // Zero out now to ease cleanup during crash recovery.
+  
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
+    ASTUnitCleanup(AST.get());
+
+  if (AST->LoadFromCompilerInvocation(PrecompilePreamble)) {
+    // Some error occurred, if caller wants to examine diagnostics, pass it the
+    // ASTUnit.
+    if (ErrAST) {
+      AST->StoredDiagnostics.swap(AST->FailedParseDiagnostics);
+      ErrAST->swap(AST);
+    }
+    return 0;
+  }
+
+  return AST.take();
+}
+
+bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
+  if (!Invocation)
+    return true;
+
+  clearFileLevelDecls();
+  
+  SimpleTimer ParsingTimer(WantTiming);
+  ParsingTimer.setOutput("Reparsing " + getMainFileName());
+
+  // Remap files.
+  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
+  PPOpts.DisableStatCache = true;
+  for (PreprocessorOptions::remapped_file_buffer_iterator 
+         R = PPOpts.remapped_file_buffer_begin(),
+         REnd = PPOpts.remapped_file_buffer_end();
+       R != REnd; 
+       ++R) {
+    delete R->second;
+  }
+  Invocation->getPreprocessorOpts().clearRemappedFiles();
+  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
+    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
+    if (const llvm::MemoryBuffer *
+            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
+      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
+                                                        memBuf);
+    } else {
+      const char *fname = fileOrBuf.get<const char *>();
+      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
+                                                        fname);
+    }
+  }
+  
+  // If we have a preamble file lying around, or if we might try to
+  // build a precompiled preamble, do so now.
+  llvm::MemoryBuffer *OverrideMainBuffer = 0;
+  if (!getPreambleFile(this).empty() || PreambleRebuildCounter > 0)
+    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
+    
+  // Clear out the diagnostics state.
+  getDiagnostics().Reset();
+  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
+  if (OverrideMainBuffer)
+    getDiagnostics().setNumWarnings(NumWarningsInPreamble);
+
+  // Parse the sources
+  bool Result = Parse(OverrideMainBuffer);
+  
+  // If we're caching global code-completion results, and the top-level 
+  // declarations have changed, clear out the code-completion cache.
+  if (!Result && ShouldCacheCodeCompletionResults &&
+      CurrentTopLevelHashValue != CompletionCacheTopLevelHashValue)
+    CacheCodeCompletionResults();
+
+  // We now need to clear out the completion info related to this translation
+  // unit; it'll be recreated if necessary.
+  CCTUInfo.reset();
+  
+  return Result;
+}
+
+//----------------------------------------------------------------------------//
+// Code completion
+//----------------------------------------------------------------------------//
+
+namespace {
+  /// \brief Code completion consumer that combines the cached code-completion
+  /// results from an ASTUnit with the code-completion results provided to it,
+  /// then passes the result on to 
+  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
+    unsigned long long NormalContexts;
+    ASTUnit &AST;
+    CodeCompleteConsumer &Next;
+    
+  public:
+    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
+                                  bool IncludeMacros, bool IncludeCodePatterns,
+                                  bool IncludeGlobals)
+      : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
+                             Next.isOutputBinary()), AST(AST), Next(Next) 
+    { 
+      // Compute the set of contexts in which we will look when we don't have
+      // any information about the specific context.
+      NormalContexts 
+        = (1LL << (CodeCompletionContext::CCC_TopLevel - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCInterface - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCImplementation - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCIvarList - 1))
+        | (1LL << (CodeCompletionContext::CCC_Statement - 1))
+        | (1LL << (CodeCompletionContext::CCC_Expression - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
+        | (1LL << (CodeCompletionContext::CCC_DotMemberAccess - 1))
+        | (1LL << (CodeCompletionContext::CCC_ArrowMemberAccess - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCPropertyAccess - 1))
+        | (1LL << (CodeCompletionContext::CCC_ObjCProtocolName - 1))
+        | (1LL << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
+        | (1LL << (CodeCompletionContext::CCC_Recovery - 1));
+
+      if (AST.getASTContext().getLangOpts().CPlusPlus)
+        NormalContexts |= (1LL << (CodeCompletionContext::CCC_EnumTag - 1))
+                   | (1LL << (CodeCompletionContext::CCC_UnionTag - 1))
+                   | (1LL << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
+    }
+    
+    virtual void ProcessCodeCompleteResults(Sema &S, 
+                                            CodeCompletionContext Context,
+                                            CodeCompletionResult *Results,
+                                            unsigned NumResults);
+    
+    virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
+                                           OverloadCandidate *Candidates,
+                                           unsigned NumCandidates) { 
+      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
+    }
+    
+    virtual CodeCompletionAllocator &getAllocator() {
+      return Next.getAllocator();
+    }
+
+    virtual CodeCompletionTUInfo &getCodeCompletionTUInfo() {
+      return Next.getCodeCompletionTUInfo();
+    }
+  };
+}
+
+/// \brief Helper function that computes which global names are hidden by the
+/// local code-completion results.
+static void CalculateHiddenNames(const CodeCompletionContext &Context,
+                                 CodeCompletionResult *Results,
+                                 unsigned NumResults,
+                                 ASTContext &Ctx,
+                          llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
+  bool OnlyTagNames = false;
+  switch (Context.getKind()) {
+  case CodeCompletionContext::CCC_Recovery:
+  case CodeCompletionContext::CCC_TopLevel:
+  case CodeCompletionContext::CCC_ObjCInterface:
+  case CodeCompletionContext::CCC_ObjCImplementation:
+  case CodeCompletionContext::CCC_ObjCIvarList:
+  case CodeCompletionContext::CCC_ClassStructUnion:
+  case CodeCompletionContext::CCC_Statement:
+  case CodeCompletionContext::CCC_Expression:
+  case CodeCompletionContext::CCC_ObjCMessageReceiver:
+  case CodeCompletionContext::CCC_DotMemberAccess:
+  case CodeCompletionContext::CCC_ArrowMemberAccess:
+  case CodeCompletionContext::CCC_ObjCPropertyAccess:
+  case CodeCompletionContext::CCC_Namespace:
+  case CodeCompletionContext::CCC_Type:
+  case CodeCompletionContext::CCC_Name:
+  case CodeCompletionContext::CCC_PotentiallyQualifiedName:
+  case CodeCompletionContext::CCC_ParenthesizedExpression:
+  case CodeCompletionContext::CCC_ObjCInterfaceName:
+    break;
+    
+  case CodeCompletionContext::CCC_EnumTag:
+  case CodeCompletionContext::CCC_UnionTag:
+  case CodeCompletionContext::CCC_ClassOrStructTag:
+    OnlyTagNames = true;
+    break;
+    
+  case CodeCompletionContext::CCC_ObjCProtocolName:
+  case CodeCompletionContext::CCC_MacroName:
+  case CodeCompletionContext::CCC_MacroNameUse:
+  case CodeCompletionContext::CCC_PreprocessorExpression:
+  case CodeCompletionContext::CCC_PreprocessorDirective:
+  case CodeCompletionContext::CCC_NaturalLanguage:
+  case CodeCompletionContext::CCC_SelectorName:
+  case CodeCompletionContext::CCC_TypeQualifiers:
+  case CodeCompletionContext::CCC_Other:
+  case CodeCompletionContext::CCC_OtherWithMacros:
+  case CodeCompletionContext::CCC_ObjCInstanceMessage:
+  case CodeCompletionContext::CCC_ObjCClassMessage:
+  case CodeCompletionContext::CCC_ObjCCategoryName:
+    // We're looking for nothing, or we're looking for names that cannot
+    // be hidden.
+    return;
+  }
+  
+  typedef CodeCompletionResult Result;
+  for (unsigned I = 0; I != NumResults; ++I) {
+    if (Results[I].Kind != Result::RK_Declaration)
+      continue;
+    
+    unsigned IDNS
+      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
+
+    bool Hiding = false;
+    if (OnlyTagNames)
+      Hiding = (IDNS & Decl::IDNS_Tag);
+    else {
+      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member | 
+                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
+                             Decl::IDNS_NonMemberOperator);
+      if (Ctx.getLangOpts().CPlusPlus)
+        HiddenIDNS |= Decl::IDNS_Tag;
+      Hiding = (IDNS & HiddenIDNS);
+    }
+  
+    if (!Hiding)
+      continue;
+    
+    DeclarationName Name = Results[I].Declaration->getDeclName();
+    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
+      HiddenNames.insert(Identifier->getName());
+    else
+      HiddenNames.insert(Name.getAsString());
+  }
+}
+
+
+void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
+                                            CodeCompletionContext Context,
+                                            CodeCompletionResult *Results,
+                                            unsigned NumResults) { 
+  // Merge the results we were given with the results we cached.
+  bool AddedResult = false;
+  unsigned InContexts  
+    = (Context.getKind() == CodeCompletionContext::CCC_Recovery? NormalContexts
+                                        : (1ULL << (Context.getKind() - 1)));
+  // Contains the set of names that are hidden by "local" completion results.
+  llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
+  typedef CodeCompletionResult Result;
+  SmallVector<Result, 8> AllResults;
+  for (ASTUnit::cached_completion_iterator 
+            C = AST.cached_completion_begin(),
+         CEnd = AST.cached_completion_end();
+       C != CEnd; ++C) {
+    // If the context we are in matches any of the contexts we are 
+    // interested in, we'll add this result.
+    if ((C->ShowInContexts & InContexts) == 0)
+      continue;
+    
+    // If we haven't added any results previously, do so now.
+    if (!AddedResult) {
+      CalculateHiddenNames(Context, Results, NumResults, S.Context, 
+                           HiddenNames);
+      AllResults.insert(AllResults.end(), Results, Results + NumResults);
+      AddedResult = true;
+    }
+    
+    // Determine whether this global completion result is hidden by a local
+    // completion result. If so, skip it.
+    if (C->Kind != CXCursor_MacroDefinition &&
+        HiddenNames.count(C->Completion->getTypedText()))
+      continue;
+    
+    // Adjust priority based on similar type classes.
+    unsigned Priority = C->Priority;
+    CXCursorKind CursorKind = C->Kind;
+    CodeCompletionString *Completion = C->Completion;
+    if (!Context.getPreferredType().isNull()) {
+      if (C->Kind == CXCursor_MacroDefinition) {
+        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
+                                         S.getLangOpts(),
+                               Context.getPreferredType()->isAnyPointerType());        
+      } else if (C->Type) {
+        CanQualType Expected
+          = S.Context.getCanonicalType(
+                               Context.getPreferredType().getUnqualifiedType());
+        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
+        if (ExpectedSTC == C->TypeClass) {
+          // We know this type is similar; check for an exact match.
+          llvm::StringMap<unsigned> &CachedCompletionTypes
+            = AST.getCachedCompletionTypes();
+          llvm::StringMap<unsigned>::iterator Pos
+            = CachedCompletionTypes.find(QualType(Expected).getAsString());
+          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
+            Priority /= CCF_ExactTypeMatch;
+          else
+            Priority /= CCF_SimilarTypeMatch;
+        }
+      }
+    }
+    
+    // Adjust the completion string, if required.
+    if (C->Kind == CXCursor_MacroDefinition &&
+        Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
+      // Create a new code-completion string that just contains the
+      // macro name, without its arguments.
+      CodeCompletionBuilder Builder(getAllocator(), getCodeCompletionTUInfo(),
+                                    CCP_CodePattern, C->Availability);
+      Builder.AddTypedTextChunk(C->Completion->getTypedText());
+      CursorKind = CXCursor_NotImplemented;
+      Priority = CCP_CodePattern;
+      Completion = Builder.TakeString();
+    }
+    
+    AllResults.push_back(Result(Completion, Priority, CursorKind, 
+                                C->Availability));
+  }
+  
+  // If we did not add any cached completion results, just forward the
+  // results we were given to the next consumer.
+  if (!AddedResult) {
+    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
+    return;
+  }
+  
+  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
+                                  AllResults.size());
+}
+
+
+
+void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
+                           RemappedFile *RemappedFiles, 
+                           unsigned NumRemappedFiles,
+                           bool IncludeMacros, 
+                           bool IncludeCodePatterns,
+                           CodeCompleteConsumer &Consumer,
+                           DiagnosticsEngine &Diag, LangOptions &LangOpts,
+                           SourceManager &SourceMgr, FileManager &FileMgr,
+                   SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
+             SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
+  if (!Invocation)
+    return;
+
+  SimpleTimer CompletionTimer(WantTiming);
+  CompletionTimer.setOutput("Code completion @ " + File + ":" +
+                            Twine(Line) + ":" + Twine(Column));
+
+  IntrusiveRefCntPtr<CompilerInvocation>
+    CCInvocation(new CompilerInvocation(*Invocation));
+
+  FrontendOptions &FrontendOpts = CCInvocation->getFrontendOpts();
+  PreprocessorOptions &PreprocessorOpts = CCInvocation->getPreprocessorOpts();
+
+  FrontendOpts.ShowMacrosInCodeCompletion
+    = IncludeMacros && CachedCompletionResults.empty();
+  FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
+  FrontendOpts.ShowGlobalSymbolsInCodeCompletion
+    = CachedCompletionResults.empty();
+  FrontendOpts.CodeCompletionAt.FileName = File;
+  FrontendOpts.CodeCompletionAt.Line = Line;
+  FrontendOpts.CodeCompletionAt.Column = Column;
+
+  // Set the language options appropriately.
+  LangOpts = *CCInvocation->getLangOpts();
+
+  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+
+  // Recover resources if we crash before exiting this method.
+  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
+    CICleanup(Clang.get());
+
+  Clang->setInvocation(&*CCInvocation);
+  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
+    
+  // Set up diagnostics, capturing any diagnostics produced.
+  Clang->setDiagnostics(&Diag);
+  ProcessWarningOptions(Diag, CCInvocation->getDiagnosticOpts());
+  CaptureDroppedDiagnostics Capture(true, 
+                                    Clang->getDiagnostics(), 
+                                    StoredDiagnostics);
+  
+  // Create the target instance.
+  Clang->getTargetOpts().Features = TargetFeatures;
+  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
+                                               Clang->getTargetOpts()));
+  if (!Clang->hasTarget()) {
+    Clang->setInvocation(0);
+    return;
+  }
+  
+  // Inform the target of the language options.
+  //
+  // FIXME: We shouldn't need to do this, the target should be immutable once
+  // created. This complexity should be lifted elsewhere.
+  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
+  
+  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
+         "Invocation must have exactly one source file!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
+         "FIXME: AST inputs not yet supported here!");
+  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
+         "IR inputs not support here!");
+
+  
+  // Use the source and file managers that we were given.
+  Clang->setFileManager(&FileMgr);
+  Clang->setSourceManager(&SourceMgr);
+
+  // Remap files.
+  PreprocessorOpts.clearRemappedFiles();
+  PreprocessorOpts.RetainRemappedFileBuffers = true;
+  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
+    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
+    if (const llvm::MemoryBuffer *
+            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
+      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, memBuf);
+      OwnedBuffers.push_back(memBuf);
+    } else {
+      const char *fname = fileOrBuf.get<const char *>();
+      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, fname);
+    }
+  }
+  
+  // Use the code completion consumer we were given, but adding any cached
+  // code-completion results.
+  AugmentedCodeCompleteConsumer *AugmentedConsumer
+    = new AugmentedCodeCompleteConsumer(*this, Consumer, 
+                                        FrontendOpts.ShowMacrosInCodeCompletion,
+                                FrontendOpts.ShowCodePatternsInCodeCompletion,
+                                FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
+  Clang->setCodeCompletionConsumer(AugmentedConsumer);
+
+  Clang->getFrontendOpts().SkipFunctionBodies = true;
+
+  // If we have a precompiled preamble, try to use it. We only allow
+  // the use of the precompiled preamble if we're if the completion
+  // point is within the main file, after the end of the precompiled
+  // preamble.
+  llvm::MemoryBuffer *OverrideMainBuffer = 0;
+  if (!getPreambleFile(this).empty()) {
+    using llvm::sys::FileStatus;
+    llvm::sys::PathWithStatus CompleteFilePath(File);
+    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
+    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
+      if (const FileStatus *MainStatus = MainPath.getFileStatus())
+        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID() &&
+            Line > 1)
+          OverrideMainBuffer
+            = getMainBufferWithPrecompiledPreamble(*CCInvocation, false, 
+                                                   Line - 1);
+  }
+
+  // If the main file has been overridden due to the use of a preamble,
+  // make that override happen and introduce the preamble.
+  PreprocessorOpts.DisableStatCache = true;
+  StoredDiagnostics.insert(StoredDiagnostics.end(),
+                           stored_diag_begin(),
+                           stored_diag_afterDriver_begin());
+  if (OverrideMainBuffer) {
+    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
+    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
+    PreprocessorOpts.PrecompiledPreambleBytes.second
+                                                    = PreambleEndsAtStartOfLine;
+    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
+    PreprocessorOpts.DisablePCHValidation = true;
+    
+    OwnedBuffers.push_back(OverrideMainBuffer);
+  } else {
+    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
+    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
+  }
+
+  // Disable the preprocessing record
+  PreprocessorOpts.DetailedRecord = false;
+  
+  OwningPtr<SyntaxOnlyAction> Act;
+  Act.reset(new SyntaxOnlyAction);
+  if (Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
+    if (OverrideMainBuffer) {
+      std::string ModName = getPreambleFile(this);
+      TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
+                                 getSourceManager(), PreambleDiagnostics,
+                                 StoredDiagnostics);
+    }
+    Act->Execute();
+    Act->EndSourceFile();
+  }
+
+  checkAndSanitizeDiags(StoredDiagnostics, getSourceManager());
+}
+
+CXSaveError ASTUnit::Save(StringRef File) {
+  // Write to a temporary file and later rename it to the actual file, to avoid
+  // possible race conditions.
+  SmallString<128> TempPath;
+  TempPath = File;
+  TempPath += "-%%%%%%%%";
+  int fd;
+  if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
+                                 /*makeAbsolute=*/false))
+    return CXSaveError_Unknown;
+
+  // FIXME: Can we somehow regenerate the stat cache here, or do we need to 
+  // unconditionally create a stat cache when we parse the file?
+  llvm::raw_fd_ostream Out(fd, /*shouldClose=*/true);
+
+  serialize(Out);
+  Out.close();
+  if (Out.has_error()) {
+    Out.clear_error();
+    return CXSaveError_Unknown;
+  }
+
+  if (llvm::sys::fs::rename(TempPath.str(), File)) {
+    bool exists;
+    llvm::sys::fs::remove(TempPath.str(), exists);
+    return CXSaveError_Unknown;
+  }
+
+  return CXSaveError_None;
+}
+
+bool ASTUnit::serialize(raw_ostream &OS) {
+  bool hasErrors = getDiagnostics().hasErrorOccurred();
+
+  SmallString<128> Buffer;
+  llvm::BitstreamWriter Stream(Buffer);
+  ASTWriter Writer(Stream);
+  // FIXME: Handle modules
+  Writer.WriteAST(getSema(), 0, std::string(), 0, "", hasErrors);
+  
+  // Write the generated bitstream to "Out".
+  if (!Buffer.empty())
+    OS.write((char *)&Buffer.front(), Buffer.size());
+
+  return false;
+}
+
+typedef ContinuousRangeMap<unsigned, int, 2> SLocRemap;
+
+static void TranslateSLoc(SourceLocation &L, SLocRemap &Remap) {
+  unsigned Raw = L.getRawEncoding();
+  const unsigned MacroBit = 1U << 31;
+  L = SourceLocation::getFromRawEncoding((Raw & MacroBit) |
+      ((Raw & ~MacroBit) + Remap.find(Raw & ~MacroBit)->second));
+}
+
+void ASTUnit::TranslateStoredDiagnostics(
+                          ASTReader *MMan,
+                          StringRef ModName,
+                          SourceManager &SrcMgr,
+                          const SmallVectorImpl<StoredDiagnostic> &Diags,
+                          SmallVectorImpl<StoredDiagnostic> &Out) {
+  // The stored diagnostic has the old source manager in it; update
+  // the locations to refer into the new source manager. We also need to remap
+  // all the locations to the new view. This includes the diag location, any
+  // associated source ranges, and the source ranges of associated fix-its.
+  // FIXME: There should be a cleaner way to do this.
+
+  SmallVector<StoredDiagnostic, 4> Result;
+  Result.reserve(Diags.size());
+  assert(MMan && "Don't have a module manager");
+  serialization::ModuleFile *Mod = MMan->ModuleMgr.lookup(ModName);
+  assert(Mod && "Don't have preamble module");
+  SLocRemap &Remap = Mod->SLocRemap;
+  for (unsigned I = 0, N = Diags.size(); I != N; ++I) {
+    // Rebuild the StoredDiagnostic.
+    const StoredDiagnostic &SD = Diags[I];
+    SourceLocation L = SD.getLocation();
+    TranslateSLoc(L, Remap);
+    FullSourceLoc Loc(L, SrcMgr);
+
+    SmallVector<CharSourceRange, 4> Ranges;
+    Ranges.reserve(SD.range_size());
+    for (StoredDiagnostic::range_iterator I = SD.range_begin(),
+                                          E = SD.range_end();
+         I != E; ++I) {
+      SourceLocation BL = I->getBegin();
+      TranslateSLoc(BL, Remap);
+      SourceLocation EL = I->getEnd();
+      TranslateSLoc(EL, Remap);
+      Ranges.push_back(CharSourceRange(SourceRange(BL, EL), I->isTokenRange()));
+    }
+
+    SmallVector<FixItHint, 2> FixIts;
+    FixIts.reserve(SD.fixit_size());
+    for (StoredDiagnostic::fixit_iterator I = SD.fixit_begin(),
+                                          E = SD.fixit_end();
+         I != E; ++I) {
+      FixIts.push_back(FixItHint());
+      FixItHint &FH = FixIts.back();
+      FH.CodeToInsert = I->CodeToInsert;
+      SourceLocation BL = I->RemoveRange.getBegin();
+      TranslateSLoc(BL, Remap);
+      SourceLocation EL = I->RemoveRange.getEnd();
+      TranslateSLoc(EL, Remap);
+      FH.RemoveRange = CharSourceRange(SourceRange(BL, EL),
+                                       I->RemoveRange.isTokenRange());
+    }
+
+    Result.push_back(StoredDiagnostic(SD.getLevel(), SD.getID(), 
+                                      SD.getMessage(), Loc, Ranges, FixIts));
+  }
+  Result.swap(Out);
+}
+
+static inline bool compLocDecl(std::pair<unsigned, Decl *> L,
+                               std::pair<unsigned, Decl *> R) {
+  return L.first < R.first;
+}
+
+void ASTUnit::addFileLevelDecl(Decl *D) {
+  assert(D);
+  
+  // We only care about local declarations.
+  if (D->isFromASTFile())
+    return;
+
+  SourceManager &SM = *SourceMgr;
+  SourceLocation Loc = D->getLocation();
+  if (Loc.isInvalid() || !SM.isLocalSourceLocation(Loc))
+    return;
+
+  // We only keep track of the file-level declarations of each file.
+  if (!D->getLexicalDeclContext()->isFileContext())
+    return;
+
+  SourceLocation FileLoc = SM.getFileLoc(Loc);
+  assert(SM.isLocalSourceLocation(FileLoc));
+  FileID FID;
+  unsigned Offset;
+  llvm::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
+  if (FID.isInvalid())
+    return;
+
+  LocDeclsTy *&Decls = FileDecls[FID];
+  if (!Decls)
+    Decls = new LocDeclsTy();
+
+  std::pair<unsigned, Decl *> LocDecl(Offset, D);
+
+  if (Decls->empty() || Decls->back().first <= Offset) {
+    Decls->push_back(LocDecl);
+    return;
+  }
+
+  LocDeclsTy::iterator
+    I = std::upper_bound(Decls->begin(), Decls->end(), LocDecl, compLocDecl);
+
+  Decls->insert(I, LocDecl);
+}
+
+void ASTUnit::findFileRegionDecls(FileID File, unsigned Offset, unsigned Length,
+                                  SmallVectorImpl<Decl *> &Decls) {
+  if (File.isInvalid())
+    return;
+
+  if (SourceMgr->isLoadedFileID(File)) {
+    assert(Ctx->getExternalSource() && "No external source!");
+    return Ctx->getExternalSource()->FindFileRegionDecls(File, Offset, Length,
+                                                         Decls);
+  }
+
+  FileDeclsTy::iterator I = FileDecls.find(File);
+  if (I == FileDecls.end())
+    return;
+
+  LocDeclsTy &LocDecls = *I->second;
+  if (LocDecls.empty())
+    return;
+
+  LocDeclsTy::iterator
+    BeginIt = std::lower_bound(LocDecls.begin(), LocDecls.end(),
+                               std::make_pair(Offset, (Decl*)0), compLocDecl);
+  if (BeginIt != LocDecls.begin())
+    --BeginIt;
+
+  // If we are pointing at a top-level decl inside an objc container, we need
+  // to backtrack until we find it otherwise we will fail to report that the
+  // region overlaps with an objc container.
+  while (BeginIt != LocDecls.begin() &&
+         BeginIt->second->isTopLevelDeclInObjCContainer())
+    --BeginIt;
+
+  LocDeclsTy::iterator
+    EndIt = std::upper_bound(LocDecls.begin(), LocDecls.end(),
+                             std::make_pair(Offset+Length, (Decl*)0),
+                             compLocDecl);
+  if (EndIt != LocDecls.end())
+    ++EndIt;
+  
+  for (LocDeclsTy::iterator DIt = BeginIt; DIt != EndIt; ++DIt)
+    Decls.push_back(DIt->second);
+}
+
+SourceLocation ASTUnit::getLocation(const FileEntry *File,
+                                    unsigned Line, unsigned Col) const {
+  const SourceManager &SM = getSourceManager();
+  SourceLocation Loc = SM.translateFileLineCol(File, Line, Col);
+  return SM.getMacroArgExpandedLocation(Loc);
+}
+
+SourceLocation ASTUnit::getLocation(const FileEntry *File,
+                                    unsigned Offset) const {
+  const SourceManager &SM = getSourceManager();
+  SourceLocation FileLoc = SM.translateFileLineCol(File, 1, 1);
+  return SM.getMacroArgExpandedLocation(FileLoc.getLocWithOffset(Offset));
+}
+
+/// \brief If \arg Loc is a loaded location from the preamble, returns
+/// the corresponding local location of the main file, otherwise it returns
+/// \arg Loc.
+SourceLocation ASTUnit::mapLocationFromPreamble(SourceLocation Loc) {
+  FileID PreambleID;
+  if (SourceMgr)
+    PreambleID = SourceMgr->getPreambleFileID();
+
+  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
+    return Loc;
+
+  unsigned Offs;
+  if (SourceMgr->isInFileID(Loc, PreambleID, &Offs) && Offs < Preamble.size()) {
+    SourceLocation FileLoc
+        = SourceMgr->getLocForStartOfFile(SourceMgr->getMainFileID());
+    return FileLoc.getLocWithOffset(Offs);
+  }
+
+  return Loc;
+}
+
+/// \brief If \arg Loc is a local location of the main file but inside the
+/// preamble chunk, returns the corresponding loaded location from the
+/// preamble, otherwise it returns \arg Loc.
+SourceLocation ASTUnit::mapLocationToPreamble(SourceLocation Loc) {
+  FileID PreambleID;
+  if (SourceMgr)
+    PreambleID = SourceMgr->getPreambleFileID();
+
+  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
+    return Loc;
+
+  unsigned Offs;
+  if (SourceMgr->isInFileID(Loc, SourceMgr->getMainFileID(), &Offs) &&
+      Offs < Preamble.size()) {
+    SourceLocation FileLoc = SourceMgr->getLocForStartOfFile(PreambleID);
+    return FileLoc.getLocWithOffset(Offs);
+  }
+
+  return Loc;
+}
+
+bool ASTUnit::isInPreambleFileID(SourceLocation Loc) {
+  FileID FID;
+  if (SourceMgr)
+    FID = SourceMgr->getPreambleFileID();
+  
+  if (Loc.isInvalid() || FID.isInvalid())
+    return false;
+  
+  return SourceMgr->isInFileID(Loc, FID);
+}
+
+bool ASTUnit::isInMainFileID(SourceLocation Loc) {
+  FileID FID;
+  if (SourceMgr)
+    FID = SourceMgr->getMainFileID();
+  
+  if (Loc.isInvalid() || FID.isInvalid())
+    return false;
+  
+  return SourceMgr->isInFileID(Loc, FID);
+}
+
+SourceLocation ASTUnit::getEndOfPreambleFileID() {
+  FileID FID;
+  if (SourceMgr)
+    FID = SourceMgr->getPreambleFileID();
+  
+  if (FID.isInvalid())
+    return SourceLocation();
+
+  return SourceMgr->getLocForEndOfFile(FID);
+}
+
+SourceLocation ASTUnit::getStartOfMainFileID() {
+  FileID FID;
+  if (SourceMgr)
+    FID = SourceMgr->getMainFileID();
+  
+  if (FID.isInvalid())
+    return SourceLocation();
+  
+  return SourceMgr->getLocForStartOfFile(FID);
+}
+
+void ASTUnit::PreambleData::countLines() const {
+  NumLines = 0;
+  if (empty())
+    return;
+
+  for (std::vector<char>::const_iterator
+         I = Buffer.begin(), E = Buffer.end(); I != E; ++I) {
+    if (*I == '\n')
+      ++NumLines;
+  }
+  if (Buffer.back() != '\n')
+    ++NumLines;
+}
+
+#ifndef NDEBUG
+ASTUnit::ConcurrencyState::ConcurrencyState() {
+  Mutex = new llvm::sys::MutexImpl(/*recursive=*/true);
+}
+
+ASTUnit::ConcurrencyState::~ConcurrencyState() {
+  delete static_cast<llvm::sys::MutexImpl *>(Mutex);
+}
+
+void ASTUnit::ConcurrencyState::start() {
+  bool acquired = static_cast<llvm::sys::MutexImpl *>(Mutex)->tryacquire();
+  assert(acquired && "Concurrent access to ASTUnit!");
+}
+
+void ASTUnit::ConcurrencyState::finish() {
+  static_cast<llvm::sys::MutexImpl *>(Mutex)->release();
+}
+
+#else // NDEBUG
+
+ASTUnit::ConcurrencyState::ConcurrencyState() {}
+ASTUnit::ConcurrencyState::~ConcurrencyState() {}
+void ASTUnit::ConcurrencyState::start() {}
+void ASTUnit::ConcurrencyState::finish() {}
+
+#endif
diff --git a/clang/lib/Frontend/CMakeLists.txt b/clang/lib/Frontend/CMakeLists.txt
new file mode 100644
index 0000000..2bee240
--- /dev/null
+++ b/clang/lib/Frontend/CMakeLists.txt
@@ -0,0 +1,61 @@
+set( LLVM_USED_LIBS
+  clangAST
+  clangBasic
+  clangDriver
+  clangEdit
+  clangLex
+  clangParse
+  clangSema
+  clangSerialization
+  )
+
+add_clang_library(clangFrontend
+  ASTConsumers.cpp
+  ASTMerge.cpp
+  ASTUnit.cpp
+  CacheTokens.cpp
+  ChainedDiagnosticConsumer.cpp
+  ChainedIncludesSource.cpp
+  CompilerInstance.cpp
+  CompilerInvocation.cpp
+  CreateInvocationFromCommandLine.cpp
+  DependencyFile.cpp
+  DependencyGraph.cpp
+  DiagnosticRenderer.cpp
+  FrontendAction.cpp
+  FrontendActions.cpp
+  FrontendOptions.cpp
+  HeaderIncludeGen.cpp
+  InitHeaderSearch.cpp
+  InitPreprocessor.cpp
+  LangStandards.cpp
+  LayoutOverrideSource.cpp
+  LogDiagnosticPrinter.cpp
+  MultiplexConsumer.cpp
+  PrintPreprocessedOutput.cpp
+  SerializedDiagnosticPrinter.cpp
+  TextDiagnostic.cpp
+  TextDiagnosticBuffer.cpp
+  TextDiagnosticPrinter.cpp
+  VerifyDiagnosticConsumer.cpp
+  Warnings.cpp
+  )
+
+IF(MSVC)
+  get_target_property(NON_ANSI_COMPILE_FLAGS clangFrontend COMPILE_FLAGS)
+  string(REPLACE /Za
+    "" NON_ANSI_COMPILE_FLAGS
+    ${NON_ANSI_COMPILE_FLAGS})
+  set_target_properties(clangFrontend PROPERTIES COMPILE_FLAGS ${NON_ANSI_COMPILE_FLAGS})
+ENDIF(MSVC)
+
+add_dependencies(clangFrontend 
+  ClangAttrClasses
+  ClangAttrList
+  ClangCC1Options
+  ClangDiagnosticFrontend 
+  ClangDiagnosticLex
+  ClangDiagnosticSema
+  ClangDriverOptions
+  ClangDeclNodes
+  ClangStmtNodes)
diff --git a/clang/lib/Frontend/CacheTokens.cpp b/clang/lib/Frontend/CacheTokens.cpp
new file mode 100644
index 0000000..58a6b8d
--- /dev/null
+++ b/clang/lib/Frontend/CacheTokens.cpp
@@ -0,0 +1,653 @@
+//===--- CacheTokens.cpp - Caching of lexer tokens for PTH support --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This provides a possible implementation of PTH support for Clang that is
+// based on caching lexed tokens and identifiers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/FileSystemStatCache.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/OnDiskHashTable.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Path.h"
+
+// FIXME: put this somewhere else?
+#ifndef S_ISDIR
+#define S_ISDIR(x) (((x)&_S_IFDIR)!=0)
+#endif
+
+using namespace clang;
+using namespace clang::io;
+
+//===----------------------------------------------------------------------===//
+// PTH-specific stuff.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class PTHEntry {
+  Offset TokenData, PPCondData;
+
+public:
+  PTHEntry() {}
+
+  PTHEntry(Offset td, Offset ppcd)
+    : TokenData(td), PPCondData(ppcd) {}
+
+  Offset getTokenOffset() const { return TokenData; }
+  Offset getPPCondTableOffset() const { return PPCondData; }
+};
+
+
+class PTHEntryKeyVariant {
+  union { const FileEntry* FE; const char* Path; };
+  enum { IsFE = 0x1, IsDE = 0x2, IsNoExist = 0x0 } Kind;
+  struct stat *StatBuf;
+public:
+  PTHEntryKeyVariant(const FileEntry *fe)
+    : FE(fe), Kind(IsFE), StatBuf(0) {}
+
+  PTHEntryKeyVariant(struct stat* statbuf, const char* path)
+    : Path(path), Kind(IsDE), StatBuf(new struct stat(*statbuf)) {}
+
+  explicit PTHEntryKeyVariant(const char* path)
+    : Path(path), Kind(IsNoExist), StatBuf(0) {}
+
+  bool isFile() const { return Kind == IsFE; }
+
+  StringRef getString() const {
+    return Kind == IsFE ? FE->getName() : Path;
+  }
+
+  unsigned getKind() const { return (unsigned) Kind; }
+
+  void EmitData(raw_ostream& Out) {
+    switch (Kind) {
+    case IsFE:
+      // Emit stat information.
+      ::Emit32(Out, FE->getInode());
+      ::Emit32(Out, FE->getDevice());
+      ::Emit16(Out, FE->getFileMode());
+      ::Emit64(Out, FE->getModificationTime());
+      ::Emit64(Out, FE->getSize());
+      break;
+    case IsDE:
+      // Emit stat information.
+      ::Emit32(Out, (uint32_t) StatBuf->st_ino);
+      ::Emit32(Out, (uint32_t) StatBuf->st_dev);
+      ::Emit16(Out, (uint16_t) StatBuf->st_mode);
+      ::Emit64(Out, (uint64_t) StatBuf->st_mtime);
+      ::Emit64(Out, (uint64_t) StatBuf->st_size);
+      delete StatBuf;
+      break;
+    default:
+      break;
+    }
+  }
+
+  unsigned getRepresentationLength() const {
+    return Kind == IsNoExist ? 0 : 4 + 4 + 2 + 8 + 8;
+  }
+};
+
+class FileEntryPTHEntryInfo {
+public:
+  typedef PTHEntryKeyVariant key_type;
+  typedef key_type key_type_ref;
+
+  typedef PTHEntry data_type;
+  typedef const PTHEntry& data_type_ref;
+
+  static unsigned ComputeHash(PTHEntryKeyVariant V) {
+    return llvm::HashString(V.getString());
+  }
+
+  static std::pair<unsigned,unsigned>
+  EmitKeyDataLength(raw_ostream& Out, PTHEntryKeyVariant V,
+                    const PTHEntry& E) {
+
+    unsigned n = V.getString().size() + 1 + 1;
+    ::Emit16(Out, n);
+
+    unsigned m = V.getRepresentationLength() + (V.isFile() ? 4 + 4 : 0);
+    ::Emit8(Out, m);
+
+    return std::make_pair(n, m);
+  }
+
+  static void EmitKey(raw_ostream& Out, PTHEntryKeyVariant V, unsigned n){
+    // Emit the entry kind.
+    ::Emit8(Out, (unsigned) V.getKind());
+    // Emit the string.
+    Out.write(V.getString().data(), n - 1);
+  }
+
+  static void EmitData(raw_ostream& Out, PTHEntryKeyVariant V,
+                       const PTHEntry& E, unsigned) {
+
+
+    // For file entries emit the offsets into the PTH file for token data
+    // and the preprocessor blocks table.
+    if (V.isFile()) {
+      ::Emit32(Out, E.getTokenOffset());
+      ::Emit32(Out, E.getPPCondTableOffset());
+    }
+
+    // Emit any other data associated with the key (i.e., stat information).
+    V.EmitData(Out);
+  }
+};
+
+class OffsetOpt {
+  bool valid;
+  Offset off;
+public:
+  OffsetOpt() : valid(false) {}
+  bool hasOffset() const { return valid; }
+  Offset getOffset() const { assert(valid); return off; }
+  void setOffset(Offset o) { off = o; valid = true; }
+};
+} // end anonymous namespace
+
+typedef OnDiskChainedHashTableGenerator<FileEntryPTHEntryInfo> PTHMap;
+
+namespace {
+class PTHWriter {
+  typedef llvm::DenseMap<const IdentifierInfo*,uint32_t> IDMap;
+  typedef llvm::StringMap<OffsetOpt, llvm::BumpPtrAllocator> CachedStrsTy;
+
+  IDMap IM;
+  llvm::raw_fd_ostream& Out;
+  Preprocessor& PP;
+  uint32_t idcount;
+  PTHMap PM;
+  CachedStrsTy CachedStrs;
+  Offset CurStrOffset;
+  std::vector<llvm::StringMapEntry<OffsetOpt>*> StrEntries;
+
+  //// Get the persistent id for the given IdentifierInfo*.
+  uint32_t ResolveID(const IdentifierInfo* II);
+
+  /// Emit a token to the PTH file.
+  void EmitToken(const Token& T);
+
+  void Emit8(uint32_t V) { ::Emit8(Out, V); }
+
+  void Emit16(uint32_t V) { ::Emit16(Out, V); }
+
+  void Emit32(uint32_t V) { ::Emit32(Out, V); }
+
+  void EmitBuf(const char *Ptr, unsigned NumBytes) {
+    Out.write(Ptr, NumBytes);
+  }
+
+  void EmitString(StringRef V) {
+    ::Emit16(Out, V.size());
+    EmitBuf(V.data(), V.size());
+  }
+
+  /// EmitIdentifierTable - Emits two tables to the PTH file.  The first is
+  ///  a hashtable mapping from identifier strings to persistent IDs.
+  ///  The second is a straight table mapping from persistent IDs to string data
+  ///  (the keys of the first table).
+  std::pair<Offset, Offset> EmitIdentifierTable();
+
+  /// EmitFileTable - Emit a table mapping from file name strings to PTH
+  /// token data.
+  Offset EmitFileTable() { return PM.Emit(Out); }
+
+  PTHEntry LexTokens(Lexer& L);
+  Offset EmitCachedSpellings();
+
+public:
+  PTHWriter(llvm::raw_fd_ostream& out, Preprocessor& pp)
+    : Out(out), PP(pp), idcount(0), CurStrOffset(0) {}
+
+  PTHMap &getPM() { return PM; }
+  void GeneratePTH(const std::string &MainFile);
+};
+} // end anonymous namespace
+
+uint32_t PTHWriter::ResolveID(const IdentifierInfo* II) {
+  // Null IdentifierInfo's map to the persistent ID 0.
+  if (!II)
+    return 0;
+
+  IDMap::iterator I = IM.find(II);
+  if (I != IM.end())
+    return I->second; // We've already added 1.
+
+  IM[II] = ++idcount; // Pre-increment since '0' is reserved for NULL.
+  return idcount;
+}
+
+void PTHWriter::EmitToken(const Token& T) {
+  // Emit the token kind, flags, and length.
+  Emit32(((uint32_t) T.getKind()) | ((((uint32_t) T.getFlags())) << 8)|
+         (((uint32_t) T.getLength()) << 16));
+
+  if (!T.isLiteral()) {
+    Emit32(ResolveID(T.getIdentifierInfo()));
+  } else {
+    // We cache *un-cleaned* spellings. This gives us 100% fidelity with the
+    // source code.
+    StringRef s(T.getLiteralData(), T.getLength());
+
+    // Get the string entry.
+    llvm::StringMapEntry<OffsetOpt> *E = &CachedStrs.GetOrCreateValue(s);
+
+    // If this is a new string entry, bump the PTH offset.
+    if (!E->getValue().hasOffset()) {
+      E->getValue().setOffset(CurStrOffset);
+      StrEntries.push_back(E);
+      CurStrOffset += s.size() + 1;
+    }
+
+    // Emit the relative offset into the PTH file for the spelling string.
+    Emit32(E->getValue().getOffset());
+  }
+
+  // Emit the offset into the original source file of this token so that we
+  // can reconstruct its SourceLocation.
+  Emit32(PP.getSourceManager().getFileOffset(T.getLocation()));
+}
+
+PTHEntry PTHWriter::LexTokens(Lexer& L) {
+  // Pad 0's so that we emit tokens to a 4-byte alignment.
+  // This speed up reading them back in.
+  Pad(Out, 4);
+  Offset TokenOff = (Offset) Out.tell();
+
+  // Keep track of matching '#if' ... '#endif'.
+  typedef std::vector<std::pair<Offset, unsigned> > PPCondTable;
+  PPCondTable PPCond;
+  std::vector<unsigned> PPStartCond;
+  bool ParsingPreprocessorDirective = false;
+  Token Tok;
+
+  do {
+    L.LexFromRawLexer(Tok);
+  NextToken:
+
+    if ((Tok.isAtStartOfLine() || Tok.is(tok::eof)) &&
+        ParsingPreprocessorDirective) {
+      // Insert an eod token into the token cache.  It has the same
+      // position as the next token that is not on the same line as the
+      // preprocessor directive.  Observe that we continue processing
+      // 'Tok' when we exit this branch.
+      Token Tmp = Tok;
+      Tmp.setKind(tok::eod);
+      Tmp.clearFlag(Token::StartOfLine);
+      Tmp.setIdentifierInfo(0);
+      EmitToken(Tmp);
+      ParsingPreprocessorDirective = false;
+    }
+
+    if (Tok.is(tok::raw_identifier)) {
+      PP.LookUpIdentifierInfo(Tok);
+      EmitToken(Tok);
+      continue;
+    }
+
+    if (Tok.is(tok::hash) && Tok.isAtStartOfLine()) {
+      // Special processing for #include.  Store the '#' token and lex
+      // the next token.
+      assert(!ParsingPreprocessorDirective);
+      Offset HashOff = (Offset) Out.tell();
+
+      // Get the next token.
+      Token NextTok;
+      L.LexFromRawLexer(NextTok);
+
+      // If we see the start of line, then we had a null directive "#".  In
+      // this case, discard both tokens.
+      if (NextTok.isAtStartOfLine())
+        goto NextToken;
+
+      // The token is the start of a directive.  Emit it.
+      EmitToken(Tok);
+      Tok = NextTok;
+
+      // Did we see 'include'/'import'/'include_next'?
+      if (Tok.isNot(tok::raw_identifier)) {
+        EmitToken(Tok);
+        continue;
+      }
+
+      IdentifierInfo* II = PP.LookUpIdentifierInfo(Tok);
+      tok::PPKeywordKind K = II->getPPKeywordID();
+
+      ParsingPreprocessorDirective = true;
+
+      switch (K) {
+      case tok::pp_not_keyword:
+        // Invalid directives "#foo" can occur in #if 0 blocks etc, just pass
+        // them through.
+      default:
+        break;
+
+      case tok::pp_include:
+      case tok::pp_import:
+      case tok::pp_include_next: {
+        // Save the 'include' token.
+        EmitToken(Tok);
+        // Lex the next token as an include string.
+        L.setParsingPreprocessorDirective(true);
+        L.LexIncludeFilename(Tok);
+        L.setParsingPreprocessorDirective(false);
+        assert(!Tok.isAtStartOfLine());
+        if (Tok.is(tok::raw_identifier))
+          PP.LookUpIdentifierInfo(Tok);
+
+        break;
+      }
+      case tok::pp_if:
+      case tok::pp_ifdef:
+      case tok::pp_ifndef: {
+        // Add an entry for '#if' and friends.  We initially set the target
+        // index to 0.  This will get backpatched when we hit #endif.
+        PPStartCond.push_back(PPCond.size());
+        PPCond.push_back(std::make_pair(HashOff, 0U));
+        break;
+      }
+      case tok::pp_endif: {
+        // Add an entry for '#endif'.  We set the target table index to itself.
+        // This will later be set to zero when emitting to the PTH file.  We
+        // use 0 for uninitialized indices because that is easier to debug.
+        unsigned index = PPCond.size();
+        // Backpatch the opening '#if' entry.
+        assert(!PPStartCond.empty());
+        assert(PPCond.size() > PPStartCond.back());
+        assert(PPCond[PPStartCond.back()].second == 0);
+        PPCond[PPStartCond.back()].second = index;
+        PPStartCond.pop_back();
+        // Add the new entry to PPCond.
+        PPCond.push_back(std::make_pair(HashOff, index));
+        EmitToken(Tok);
+
+        // Some files have gibberish on the same line as '#endif'.
+        // Discard these tokens.
+        do
+          L.LexFromRawLexer(Tok);
+        while (Tok.isNot(tok::eof) && !Tok.isAtStartOfLine());
+        // We have the next token in hand.
+        // Don't immediately lex the next one.
+        goto NextToken;
+      }
+      case tok::pp_elif:
+      case tok::pp_else: {
+        // Add an entry for #elif or #else.
+        // This serves as both a closing and opening of a conditional block.
+        // This means that its entry will get backpatched later.
+        unsigned index = PPCond.size();
+        // Backpatch the previous '#if' entry.
+        assert(!PPStartCond.empty());
+        assert(PPCond.size() > PPStartCond.back());
+        assert(PPCond[PPStartCond.back()].second == 0);
+        PPCond[PPStartCond.back()].second = index;
+        PPStartCond.pop_back();
+        // Now add '#elif' as a new block opening.
+        PPCond.push_back(std::make_pair(HashOff, 0U));
+        PPStartCond.push_back(index);
+        break;
+      }
+      }
+    }
+
+    EmitToken(Tok);
+  }
+  while (Tok.isNot(tok::eof));
+
+  assert(PPStartCond.empty() && "Error: imblanced preprocessor conditionals.");
+
+  // Next write out PPCond.
+  Offset PPCondOff = (Offset) Out.tell();
+
+  // Write out the size of PPCond so that clients can identifer empty tables.
+  Emit32(PPCond.size());
+
+  for (unsigned i = 0, e = PPCond.size(); i!=e; ++i) {
+    Emit32(PPCond[i].first - TokenOff);
+    uint32_t x = PPCond[i].second;
+    assert(x != 0 && "PPCond entry not backpatched.");
+    // Emit zero for #endifs.  This allows us to do checking when
+    // we read the PTH file back in.
+    Emit32(x == i ? 0 : x);
+  }
+
+  return PTHEntry(TokenOff, PPCondOff);
+}
+
+Offset PTHWriter::EmitCachedSpellings() {
+  // Write each cached strings to the PTH file.
+  Offset SpellingsOff = Out.tell();
+
+  for (std::vector<llvm::StringMapEntry<OffsetOpt>*>::iterator
+       I = StrEntries.begin(), E = StrEntries.end(); I!=E; ++I)
+    EmitBuf((*I)->getKeyData(), (*I)->getKeyLength()+1 /*nul included*/);
+
+  return SpellingsOff;
+}
+
+void PTHWriter::GeneratePTH(const std::string &MainFile) {
+  // Generate the prologue.
+  Out << "cfe-pth";
+  Emit32(PTHManager::Version);
+
+  // Leave 4 words for the prologue.
+  Offset PrologueOffset = Out.tell();
+  for (unsigned i = 0; i < 4; ++i)
+    Emit32(0);
+
+  // Write the name of the MainFile.
+  if (!MainFile.empty()) {
+    EmitString(MainFile);
+  } else {
+    // String with 0 bytes.
+    Emit16(0);
+  }
+  Emit8(0);
+
+  // Iterate over all the files in SourceManager.  Create a lexer
+  // for each file and cache the tokens.
+  SourceManager &SM = PP.getSourceManager();
+  const LangOptions &LOpts = PP.getLangOpts();
+
+  for (SourceManager::fileinfo_iterator I = SM.fileinfo_begin(),
+       E = SM.fileinfo_end(); I != E; ++I) {
+    const SrcMgr::ContentCache &C = *I->second;
+    const FileEntry *FE = C.OrigEntry;
+
+    // FIXME: Handle files with non-absolute paths.
+    if (llvm::sys::path::is_relative(FE->getName()))
+      continue;
+
+    const llvm::MemoryBuffer *B = C.getBuffer(PP.getDiagnostics(), SM);
+    if (!B) continue;
+
+    FileID FID = SM.createFileID(FE, SourceLocation(), SrcMgr::C_User);
+    const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+    Lexer L(FID, FromFile, SM, LOpts);
+    PM.insert(FE, LexTokens(L));
+  }
+
+  // Write out the identifier table.
+  const std::pair<Offset,Offset> &IdTableOff = EmitIdentifierTable();
+
+  // Write out the cached strings table.
+  Offset SpellingOff = EmitCachedSpellings();
+
+  // Write out the file table.
+  Offset FileTableOff = EmitFileTable();
+
+  // Finally, write the prologue.
+  Out.seek(PrologueOffset);
+  Emit32(IdTableOff.first);
+  Emit32(IdTableOff.second);
+  Emit32(FileTableOff);
+  Emit32(SpellingOff);
+}
+
+namespace {
+/// StatListener - A simple "interpose" object used to monitor stat calls
+/// invoked by FileManager while processing the original sources used
+/// as input to PTH generation.  StatListener populates the PTHWriter's
+/// file map with stat information for directories as well as negative stats.
+/// Stat information for files are populated elsewhere.
+class StatListener : public FileSystemStatCache {
+  PTHMap &PM;
+public:
+  StatListener(PTHMap &pm) : PM(pm) {}
+  ~StatListener() {}
+
+  LookupResult getStat(const char *Path, struct stat &StatBuf,
+                       int *FileDescriptor) {
+    LookupResult Result = statChained(Path, StatBuf, FileDescriptor);
+
+    if (Result == CacheMissing) // Failed 'stat'.
+      PM.insert(PTHEntryKeyVariant(Path), PTHEntry());
+    else if (S_ISDIR(StatBuf.st_mode)) {
+      // Only cache directories with absolute paths.
+      if (llvm::sys::path::is_relative(Path))
+        return Result;
+
+      PM.insert(PTHEntryKeyVariant(&StatBuf, Path), PTHEntry());
+    }
+
+    return Result;
+  }
+};
+} // end anonymous namespace
+
+
+void clang::CacheTokens(Preprocessor &PP, llvm::raw_fd_ostream* OS) {
+  // Get the name of the main file.
+  const SourceManager &SrcMgr = PP.getSourceManager();
+  const FileEntry *MainFile = SrcMgr.getFileEntryForID(SrcMgr.getMainFileID());
+  SmallString<128> MainFilePath(MainFile->getName());
+
+  llvm::sys::fs::make_absolute(MainFilePath);
+
+  // Create the PTHWriter.
+  PTHWriter PW(*OS, PP);
+
+  // Install the 'stat' system call listener in the FileManager.
+  StatListener *StatCache = new StatListener(PW.getPM());
+  PP.getFileManager().addStatCache(StatCache, /*AtBeginning=*/true);
+
+  // Lex through the entire file.  This will populate SourceManager with
+  // all of the header information.
+  Token Tok;
+  PP.EnterMainSourceFile();
+  do { PP.Lex(Tok); } while (Tok.isNot(tok::eof));
+
+  // Generate the PTH file.
+  PP.getFileManager().removeStatCache(StatCache);
+  PW.GeneratePTH(MainFilePath.str());
+}
+
+//===----------------------------------------------------------------------===//
+
+namespace {
+class PTHIdKey {
+public:
+  const IdentifierInfo* II;
+  uint32_t FileOffset;
+};
+
+class PTHIdentifierTableTrait {
+public:
+  typedef PTHIdKey* key_type;
+  typedef key_type  key_type_ref;
+
+  typedef uint32_t  data_type;
+  typedef data_type data_type_ref;
+
+  static unsigned ComputeHash(PTHIdKey* key) {
+    return llvm::HashString(key->II->getName());
+  }
+
+  static std::pair<unsigned,unsigned>
+  EmitKeyDataLength(raw_ostream& Out, const PTHIdKey* key, uint32_t) {
+    unsigned n = key->II->getLength() + 1;
+    ::Emit16(Out, n);
+    return std::make_pair(n, sizeof(uint32_t));
+  }
+
+  static void EmitKey(raw_ostream& Out, PTHIdKey* key, unsigned n) {
+    // Record the location of the key data.  This is used when generating
+    // the mapping from persistent IDs to strings.
+    key->FileOffset = Out.tell();
+    Out.write(key->II->getNameStart(), n);
+  }
+
+  static void EmitData(raw_ostream& Out, PTHIdKey*, uint32_t pID,
+                       unsigned) {
+    ::Emit32(Out, pID);
+  }
+};
+} // end anonymous namespace
+
+/// EmitIdentifierTable - Emits two tables to the PTH file.  The first is
+///  a hashtable mapping from identifier strings to persistent IDs.  The second
+///  is a straight table mapping from persistent IDs to string data (the
+///  keys of the first table).
+///
+std::pair<Offset,Offset> PTHWriter::EmitIdentifierTable() {
+  // Build two maps:
+  //  (1) an inverse map from persistent IDs -> (IdentifierInfo*,Offset)
+  //  (2) a map from (IdentifierInfo*, Offset)* -> persistent IDs
+
+  // Note that we use 'calloc', so all the bytes are 0.
+  PTHIdKey *IIDMap = (PTHIdKey*)calloc(idcount, sizeof(PTHIdKey));
+
+  // Create the hashtable.
+  OnDiskChainedHashTableGenerator<PTHIdentifierTableTrait> IIOffMap;
+
+  // Generate mapping from persistent IDs -> IdentifierInfo*.
+  for (IDMap::iterator I = IM.begin(), E = IM.end(); I != E; ++I) {
+    // Decrement by 1 because we are using a vector for the lookup and
+    // 0 is reserved for NULL.
+    assert(I->second > 0);
+    assert(I->second-1 < idcount);
+    unsigned idx = I->second-1;
+
+    // Store the mapping from persistent ID to IdentifierInfo*
+    IIDMap[idx].II = I->first;
+
+    // Store the reverse mapping in a hashtable.
+    IIOffMap.insert(&IIDMap[idx], I->second);
+  }
+
+  // Write out the inverse map first.  This causes the PCIDKey entries to
+  // record PTH file offsets for the string data.  This is used to write
+  // the second table.
+  Offset StringTableOffset = IIOffMap.Emit(Out);
+
+  // Now emit the table mapping from persistent IDs to PTH file offsets.
+  Offset IDOff = Out.tell();
+  Emit32(idcount);  // Emit the number of identifiers.
+  for (unsigned i = 0 ; i < idcount; ++i)
+    Emit32(IIDMap[i].FileOffset);
+
+  // Finally, release the inverse map.
+  free(IIDMap);
+
+  return std::make_pair(IDOff, StringTableOffset);
+}
diff --git a/clang/lib/Frontend/ChainedDiagnosticConsumer.cpp b/clang/lib/Frontend/ChainedDiagnosticConsumer.cpp
new file mode 100644
index 0000000..c1d3db8
--- /dev/null
+++ b/clang/lib/Frontend/ChainedDiagnosticConsumer.cpp
@@ -0,0 +1,14 @@
+//===- ChainedDiagnosticConsumer.cpp - Chain Diagnostic Clients -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ChainedDiagnosticConsumer.h"
+
+using namespace clang;
+
+void ChainedDiagnosticConsumer::anchor() { }
diff --git a/clang/lib/Frontend/ChainedIncludesSource.cpp b/clang/lib/Frontend/ChainedIncludesSource.cpp
new file mode 100644
index 0000000..dbb06bd
--- /dev/null
+++ b/clang/lib/Frontend/ChainedIncludesSource.cpp
@@ -0,0 +1,240 @@
+//===- ChainedIncludesSource.cpp - Chained PCHs in Memory -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the ChainedIncludesSource class, which converts headers
+//  to chained PCHs in memory, mainly used for testing.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ChainedIncludesSource.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Serialization/ASTReader.h"
+#include "clang/Serialization/ASTWriter.h"
+#include "clang/Parse/ParseAST.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace clang;
+
+static ASTReader *createASTReader(CompilerInstance &CI,
+                                  StringRef pchFile,  
+                                  SmallVector<llvm::MemoryBuffer *, 4> &memBufs,
+                                  SmallVector<std::string, 4> &bufNames,
+                             ASTDeserializationListener *deserialListener = 0) {
+  Preprocessor &PP = CI.getPreprocessor();
+  OwningPtr<ASTReader> Reader;
+  Reader.reset(new ASTReader(PP, CI.getASTContext(), /*isysroot=*/"",
+                             /*DisableValidation=*/true));
+  for (unsigned ti = 0; ti < bufNames.size(); ++ti) {
+    StringRef sr(bufNames[ti]);
+    Reader->addInMemoryBuffer(sr, memBufs[ti]);
+  }
+  Reader->setDeserializationListener(deserialListener);
+  switch (Reader->ReadAST(pchFile, serialization::MK_PCH)) {
+  case ASTReader::Success:
+    // Set the predefines buffer as suggested by the PCH reader.
+    PP.setPredefines(Reader->getSuggestedPredefines());
+    return Reader.take();
+
+  case ASTReader::Failure:
+  case ASTReader::IgnorePCH:
+    break;
+  }
+  return 0;
+}
+
+ChainedIncludesSource::~ChainedIncludesSource() {
+  for (unsigned i = 0, e = CIs.size(); i != e; ++i)
+    delete CIs[i];
+}
+
+ChainedIncludesSource *ChainedIncludesSource::create(CompilerInstance &CI) {
+
+  std::vector<std::string> &includes = CI.getPreprocessorOpts().ChainedIncludes;
+  assert(!includes.empty() && "No '-chain-include' in options!");
+
+  OwningPtr<ChainedIncludesSource> source(new ChainedIncludesSource());
+  InputKind IK = CI.getFrontendOpts().Inputs[0].Kind;
+
+  SmallVector<llvm::MemoryBuffer *, 4> serialBufs;
+  SmallVector<std::string, 4> serialBufNames;
+
+  for (unsigned i = 0, e = includes.size(); i != e; ++i) {
+    bool firstInclude = (i == 0);
+    OwningPtr<CompilerInvocation> CInvok;
+    CInvok.reset(new CompilerInvocation(CI.getInvocation()));
+    
+    CInvok->getPreprocessorOpts().ChainedIncludes.clear();
+    CInvok->getPreprocessorOpts().ImplicitPCHInclude.clear();
+    CInvok->getPreprocessorOpts().ImplicitPTHInclude.clear();
+    CInvok->getPreprocessorOpts().DisablePCHValidation = true;
+    CInvok->getPreprocessorOpts().Includes.clear();
+    CInvok->getPreprocessorOpts().MacroIncludes.clear();
+    CInvok->getPreprocessorOpts().Macros.clear();
+    
+    CInvok->getFrontendOpts().Inputs.clear();
+    CInvok->getFrontendOpts().Inputs.push_back(FrontendInputFile(includes[i],
+                                                                 IK));
+
+    TextDiagnosticPrinter *DiagClient =
+      new TextDiagnosticPrinter(llvm::errs(), DiagnosticOptions());
+    IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
+        new DiagnosticsEngine(DiagID, DiagClient));
+
+    OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+    Clang->setInvocation(CInvok.take());
+    Clang->setDiagnostics(Diags.getPtr());
+    Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
+                                                  Clang->getTargetOpts()));
+    Clang->createFileManager();
+    Clang->createSourceManager(Clang->getFileManager());
+    Clang->createPreprocessor();
+    Clang->getDiagnosticClient().BeginSourceFile(Clang->getLangOpts(),
+                                                 &Clang->getPreprocessor());
+    Clang->createASTContext();
+
+    SmallVector<char, 256> serialAST;
+    llvm::raw_svector_ostream OS(serialAST);
+    OwningPtr<ASTConsumer> consumer;
+    consumer.reset(new PCHGenerator(Clang->getPreprocessor(), "-", 0,
+                                    /*isysroot=*/"", &OS));
+    Clang->getASTContext().setASTMutationListener(
+                                            consumer->GetASTMutationListener());
+    Clang->setASTConsumer(consumer.take());
+    Clang->createSema(TU_Prefix, 0);
+
+    if (firstInclude) {
+      Preprocessor &PP = Clang->getPreprocessor();
+      PP.getBuiltinInfo().InitializeBuiltins(PP.getIdentifierTable(),
+                                             PP.getLangOpts());
+    } else {
+      assert(!serialBufs.empty());
+      SmallVector<llvm::MemoryBuffer *, 4> bufs;
+      for (unsigned si = 0, se = serialBufs.size(); si != se; ++si) {
+        bufs.push_back(llvm::MemoryBuffer::getMemBufferCopy(
+                             StringRef(serialBufs[si]->getBufferStart(),
+                                             serialBufs[si]->getBufferSize())));
+      }
+      std::string pchName = includes[i-1];
+      llvm::raw_string_ostream os(pchName);
+      os << ".pch" << i-1;
+      os.flush();
+      
+      serialBufNames.push_back(pchName);
+
+      OwningPtr<ExternalASTSource> Reader;
+
+      Reader.reset(createASTReader(*Clang, pchName, bufs, serialBufNames, 
+        Clang->getASTConsumer().GetASTDeserializationListener()));
+      if (!Reader)
+        return 0;
+      Clang->getASTContext().setExternalSource(Reader);
+    }
+    
+    if (!Clang->InitializeSourceManager(includes[i]))
+      return 0;
+
+    ParseAST(Clang->getSema());
+    OS.flush();
+    Clang->getDiagnosticClient().EndSourceFile();
+    serialBufs.push_back(
+      llvm::MemoryBuffer::getMemBufferCopy(StringRef(serialAST.data(),
+                                                           serialAST.size())));
+    source->CIs.push_back(Clang.take());
+  }
+
+  assert(!serialBufs.empty());
+  std::string pchName = includes.back() + ".pch-final";
+  serialBufNames.push_back(pchName);
+  OwningPtr<ASTReader> Reader;
+  Reader.reset(createASTReader(CI, pchName, serialBufs, serialBufNames));
+  if (!Reader)
+    return 0;
+
+  source->FinalReader.reset(Reader.take());
+  return source.take();
+}
+
+//===----------------------------------------------------------------------===//
+// ExternalASTSource interface.
+//===----------------------------------------------------------------------===//
+
+Decl *ChainedIncludesSource::GetExternalDecl(uint32_t ID) {
+  return getFinalReader().GetExternalDecl(ID);
+}
+Selector ChainedIncludesSource::GetExternalSelector(uint32_t ID) {
+  return getFinalReader().GetExternalSelector(ID);
+}
+uint32_t ChainedIncludesSource::GetNumExternalSelectors() {
+  return getFinalReader().GetNumExternalSelectors();
+}
+Stmt *ChainedIncludesSource::GetExternalDeclStmt(uint64_t Offset) {
+  return getFinalReader().GetExternalDeclStmt(Offset);
+}
+CXXBaseSpecifier *
+ChainedIncludesSource::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
+  return getFinalReader().GetExternalCXXBaseSpecifiers(Offset);
+}
+DeclContextLookupResult
+ChainedIncludesSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
+                                                      DeclarationName Name) {
+  return getFinalReader().FindExternalVisibleDeclsByName(DC, Name);
+}
+ExternalLoadResult 
+ChainedIncludesSource::FindExternalLexicalDecls(const DeclContext *DC,
+                                      bool (*isKindWeWant)(Decl::Kind),
+                                      SmallVectorImpl<Decl*> &Result) {
+  return getFinalReader().FindExternalLexicalDecls(DC, isKindWeWant, Result);
+}
+void ChainedIncludesSource::CompleteType(TagDecl *Tag) {
+  return getFinalReader().CompleteType(Tag);
+}
+void ChainedIncludesSource::CompleteType(ObjCInterfaceDecl *Class) {
+  return getFinalReader().CompleteType(Class);
+}
+void ChainedIncludesSource::StartedDeserializing() {
+  return getFinalReader().StartedDeserializing();
+}
+void ChainedIncludesSource::FinishedDeserializing() {
+  return getFinalReader().FinishedDeserializing();
+}
+void ChainedIncludesSource::StartTranslationUnit(ASTConsumer *Consumer) {
+  return getFinalReader().StartTranslationUnit(Consumer);
+}
+void ChainedIncludesSource::PrintStats() {
+  return getFinalReader().PrintStats();
+}
+void ChainedIncludesSource::getMemoryBufferSizes(MemoryBufferSizes &sizes)const{
+  for (unsigned i = 0, e = CIs.size(); i != e; ++i) {
+    if (const ExternalASTSource *eSrc =
+        CIs[i]->getASTContext().getExternalSource()) {
+      eSrc->getMemoryBufferSizes(sizes);
+    }
+  }
+
+  getFinalReader().getMemoryBufferSizes(sizes);
+}
+
+void ChainedIncludesSource::InitializeSema(Sema &S) {
+  return getFinalReader().InitializeSema(S);
+}
+void ChainedIncludesSource::ForgetSema() {
+  return getFinalReader().ForgetSema();
+}
+void ChainedIncludesSource::ReadMethodPool(Selector Sel) {
+  getFinalReader().ReadMethodPool(Sel);
+}
+bool ChainedIncludesSource::LookupUnqualified(LookupResult &R, Scope *S) {
+  return getFinalReader().LookupUnqualified(R, S);
+}
+
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
new file mode 100644
index 0000000..803e418
--- /dev/null
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -0,0 +1,1101 @@
+//===--- CompilerInstance.cpp ---------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Sema/Sema.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/Version.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PTHManager.h"
+#include "clang/Frontend/ChainedDiagnosticConsumer.h"
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/LogDiagnosticPrinter.h"
+#include "clang/Frontend/SerializedDiagnosticPrinter.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/VerifyDiagnosticConsumer.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Serialization/ASTReader.h"
+#include "clang/Sema/CodeCompleteConsumer.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/LockFileManager.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Program.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/system_error.h"
+#include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Config/config.h"
+
+using namespace clang;
+
+CompilerInstance::CompilerInstance()
+  : Invocation(new CompilerInvocation()), ModuleManager(0) {
+}
+
+CompilerInstance::~CompilerInstance() {
+}
+
+void CompilerInstance::setInvocation(CompilerInvocation *Value) {
+  Invocation = Value;
+}
+
+void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
+  Diagnostics = Value;
+}
+
+void CompilerInstance::setTarget(TargetInfo *Value) {
+  Target = Value;
+}
+
+void CompilerInstance::setFileManager(FileManager *Value) {
+  FileMgr = Value;
+}
+
+void CompilerInstance::setSourceManager(SourceManager *Value) {
+  SourceMgr = Value;
+}
+
+void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
+
+void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
+
+void CompilerInstance::setSema(Sema *S) {
+  TheSema.reset(S);
+}
+
+void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
+  Consumer.reset(Value);
+}
+
+void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
+  CompletionConsumer.reset(Value);
+  getFrontendOpts().SkipFunctionBodies = Value != 0;
+}
+
+// Diagnostics
+static void SetUpBuildDumpLog(const DiagnosticOptions &DiagOpts,
+                              unsigned argc, const char* const *argv,
+                              DiagnosticsEngine &Diags) {
+  std::string ErrorInfo;
+  OwningPtr<raw_ostream> OS(
+    new llvm::raw_fd_ostream(DiagOpts.DumpBuildInformation.c_str(), ErrorInfo));
+  if (!ErrorInfo.empty()) {
+    Diags.Report(diag::err_fe_unable_to_open_logfile)
+                 << DiagOpts.DumpBuildInformation << ErrorInfo;
+    return;
+  }
+
+  (*OS) << "clang -cc1 command line arguments: ";
+  for (unsigned i = 0; i != argc; ++i)
+    (*OS) << argv[i] << ' ';
+  (*OS) << '\n';
+
+  // Chain in a diagnostic client which will log the diagnostics.
+  DiagnosticConsumer *Logger =
+    new TextDiagnosticPrinter(*OS.take(), DiagOpts, /*OwnsOutputStream=*/true);
+  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
+}
+
+static void SetUpDiagnosticLog(const DiagnosticOptions &DiagOpts,
+                               const CodeGenOptions *CodeGenOpts,
+                               DiagnosticsEngine &Diags) {
+  std::string ErrorInfo;
+  bool OwnsStream = false;
+  raw_ostream *OS = &llvm::errs();
+  if (DiagOpts.DiagnosticLogFile != "-") {
+    // Create the output stream.
+    llvm::raw_fd_ostream *FileOS(
+      new llvm::raw_fd_ostream(DiagOpts.DiagnosticLogFile.c_str(),
+                               ErrorInfo, llvm::raw_fd_ostream::F_Append));
+    if (!ErrorInfo.empty()) {
+      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
+        << DiagOpts.DumpBuildInformation << ErrorInfo;
+    } else {
+      FileOS->SetUnbuffered();
+      FileOS->SetUseAtomicWrites(true);
+      OS = FileOS;
+      OwnsStream = true;
+    }
+  }
+
+  // Chain in the diagnostic client which will log the diagnostics.
+  LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
+                                                          OwnsStream);
+  if (CodeGenOpts)
+    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
+  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
+}
+
+static void SetupSerializedDiagnostics(const DiagnosticOptions &DiagOpts,
+                                       DiagnosticsEngine &Diags,
+                                       StringRef OutputFile) {
+  std::string ErrorInfo;
+  OwningPtr<llvm::raw_fd_ostream> OS;
+  OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
+                                    llvm::raw_fd_ostream::F_Binary));
+  
+  if (!ErrorInfo.empty()) {
+    Diags.Report(diag::warn_fe_serialized_diag_failure)
+      << OutputFile << ErrorInfo;
+    return;
+  }
+  
+  DiagnosticConsumer *SerializedConsumer =
+    clang::serialized_diags::create(OS.take(), DiagOpts);
+
+  
+  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
+                                                SerializedConsumer));
+}
+
+void CompilerInstance::createDiagnostics(int Argc, const char* const *Argv,
+                                         DiagnosticConsumer *Client,
+                                         bool ShouldOwnClient,
+                                         bool ShouldCloneClient) {
+  Diagnostics = createDiagnostics(getDiagnosticOpts(), Argc, Argv, Client,
+                                  ShouldOwnClient, ShouldCloneClient,
+                                  &getCodeGenOpts());
+}
+
+IntrusiveRefCntPtr<DiagnosticsEngine>
+CompilerInstance::createDiagnostics(const DiagnosticOptions &Opts,
+                                    int Argc, const char* const *Argv,
+                                    DiagnosticConsumer *Client,
+                                    bool ShouldOwnClient,
+                                    bool ShouldCloneClient,
+                                    const CodeGenOptions *CodeGenOpts) {
+  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+  IntrusiveRefCntPtr<DiagnosticsEngine>
+      Diags(new DiagnosticsEngine(DiagID));
+
+  // Create the diagnostic client for reporting errors or for
+  // implementing -verify.
+  if (Client) {
+    if (ShouldCloneClient)
+      Diags->setClient(Client->clone(*Diags), ShouldOwnClient);
+    else
+      Diags->setClient(Client, ShouldOwnClient);
+  } else
+    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
+
+  // Chain in -verify checker, if requested.
+  if (Opts.VerifyDiagnostics)
+    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
+
+  // Chain in -diagnostic-log-file dumper, if requested.
+  if (!Opts.DiagnosticLogFile.empty())
+    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
+
+  if (!Opts.DumpBuildInformation.empty())
+    SetUpBuildDumpLog(Opts, Argc, Argv, *Diags);
+
+  if (!Opts.DiagnosticSerializationFile.empty())
+    SetupSerializedDiagnostics(Opts, *Diags,
+                               Opts.DiagnosticSerializationFile);
+  
+  // Configure our handling of diagnostics.
+  ProcessWarningOptions(*Diags, Opts);
+
+  return Diags;
+}
+
+// File Manager
+
+void CompilerInstance::createFileManager() {
+  FileMgr = new FileManager(getFileSystemOpts());
+}
+
+// Source Manager
+
+void CompilerInstance::createSourceManager(FileManager &FileMgr) {
+  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
+}
+
+// Preprocessor
+
+void CompilerInstance::createPreprocessor() {
+  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
+
+  // Create a PTH manager if we are using some form of a token cache.
+  PTHManager *PTHMgr = 0;
+  if (!PPOpts.TokenCache.empty())
+    PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
+
+  // Create the Preprocessor.
+  HeaderSearch *HeaderInfo = new HeaderSearch(getFileManager(), 
+                                              getDiagnostics(),
+                                              getLangOpts(),
+                                              &getTarget());
+  PP = new Preprocessor(getDiagnostics(), getLangOpts(), &getTarget(),
+                        getSourceManager(), *HeaderInfo, *this, PTHMgr,
+                        /*OwnsHeaderSearch=*/true);
+
+  // Note that this is different then passing PTHMgr to Preprocessor's ctor.
+  // That argument is used as the IdentifierInfoLookup argument to
+  // IdentifierTable's ctor.
+  if (PTHMgr) {
+    PTHMgr->setPreprocessor(&*PP);
+    PP->setPTHManager(PTHMgr);
+  }
+
+  if (PPOpts.DetailedRecord)
+    PP->createPreprocessingRecord(PPOpts.DetailedRecordConditionalDirectives);
+
+  InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
+
+  // Set up the module path, including the hash for the
+  // module-creation options.
+  SmallString<256> SpecificModuleCache(
+                           getHeaderSearchOpts().ModuleCachePath);
+  if (!getHeaderSearchOpts().DisableModuleHash)
+    llvm::sys::path::append(SpecificModuleCache,
+                            getInvocation().getModuleHash());
+  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
+
+  // Handle generating dependencies, if requested.
+  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
+  if (!DepOpts.OutputFile.empty())
+    AttachDependencyFileGen(*PP, DepOpts);
+  if (!DepOpts.DOTOutputFile.empty())
+    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
+                             getHeaderSearchOpts().Sysroot);
+
+  
+  // Handle generating header include information, if requested.
+  if (DepOpts.ShowHeaderIncludes)
+    AttachHeaderIncludeGen(*PP);
+  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
+    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
+    if (OutputPath == "-")
+      OutputPath = "";
+    AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
+                           /*ShowDepth=*/false);
+  }
+}
+
+// ASTContext
+
+void CompilerInstance::createASTContext() {
+  Preprocessor &PP = getPreprocessor();
+  Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
+                           &getTarget(), PP.getIdentifierTable(),
+                           PP.getSelectorTable(), PP.getBuiltinInfo(),
+                           /*size_reserve=*/ 0);
+}
+
+// ExternalASTSource
+
+void CompilerInstance::createPCHExternalASTSource(StringRef Path,
+                                                  bool DisablePCHValidation,
+                                                  bool DisableStatCache,
+                                                bool AllowPCHWithCompilerErrors,
+                                                 void *DeserializationListener){
+  OwningPtr<ExternalASTSource> Source;
+  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
+  Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
+                                          DisablePCHValidation,
+                                          DisableStatCache,
+                                          AllowPCHWithCompilerErrors,
+                                          getPreprocessor(), getASTContext(),
+                                          DeserializationListener,
+                                          Preamble));
+  ModuleManager = static_cast<ASTReader*>(Source.get());
+  getASTContext().setExternalSource(Source);
+}
+
+ExternalASTSource *
+CompilerInstance::createPCHExternalASTSource(StringRef Path,
+                                             const std::string &Sysroot,
+                                             bool DisablePCHValidation,
+                                             bool DisableStatCache,
+                                             bool AllowPCHWithCompilerErrors,
+                                             Preprocessor &PP,
+                                             ASTContext &Context,
+                                             void *DeserializationListener,
+                                             bool Preamble) {
+  OwningPtr<ASTReader> Reader;
+  Reader.reset(new ASTReader(PP, Context,
+                             Sysroot.empty() ? "" : Sysroot.c_str(),
+                             DisablePCHValidation, DisableStatCache,
+                             AllowPCHWithCompilerErrors));
+
+  Reader->setDeserializationListener(
+            static_cast<ASTDeserializationListener *>(DeserializationListener));
+  switch (Reader->ReadAST(Path,
+                          Preamble ? serialization::MK_Preamble
+                                   : serialization::MK_PCH)) {
+  case ASTReader::Success:
+    // Set the predefines buffer as suggested by the PCH reader. Typically, the
+    // predefines buffer will be empty.
+    PP.setPredefines(Reader->getSuggestedPredefines());
+    return Reader.take();
+
+  case ASTReader::Failure:
+    // Unrecoverable failure: don't even try to process the input file.
+    break;
+
+  case ASTReader::IgnorePCH:
+    // No suitable PCH file could be found. Return an error.
+    break;
+  }
+
+  return 0;
+}
+
+// Code Completion
+
+static bool EnableCodeCompletion(Preprocessor &PP,
+                                 const std::string &Filename,
+                                 unsigned Line,
+                                 unsigned Column) {
+  // Tell the source manager to chop off the given file at a specific
+  // line and column.
+  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
+  if (!Entry) {
+    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
+      << Filename;
+    return true;
+  }
+
+  // Truncate the named file at the given line/column.
+  PP.SetCodeCompletionPoint(Entry, Line, Column);
+  return false;
+}
+
+void CompilerInstance::createCodeCompletionConsumer() {
+  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
+  if (!CompletionConsumer) {
+    setCodeCompletionConsumer(
+      createCodeCompletionConsumer(getPreprocessor(),
+                                   Loc.FileName, Loc.Line, Loc.Column,
+                                   getFrontendOpts().ShowMacrosInCodeCompletion,
+                             getFrontendOpts().ShowCodePatternsInCodeCompletion,
+                           getFrontendOpts().ShowGlobalSymbolsInCodeCompletion,
+                                   llvm::outs()));
+    if (!CompletionConsumer)
+      return;
+  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
+                                  Loc.Line, Loc.Column)) {
+    setCodeCompletionConsumer(0);
+    return;
+  }
+
+  if (CompletionConsumer->isOutputBinary() &&
+      llvm::sys::Program::ChangeStdoutToBinary()) {
+    getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
+    setCodeCompletionConsumer(0);
+  }
+}
+
+void CompilerInstance::createFrontendTimer() {
+  FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
+}
+
+CodeCompleteConsumer *
+CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
+                                               const std::string &Filename,
+                                               unsigned Line,
+                                               unsigned Column,
+                                               bool ShowMacros,
+                                               bool ShowCodePatterns,
+                                               bool ShowGlobals,
+                                               raw_ostream &OS) {
+  if (EnableCodeCompletion(PP, Filename, Line, Column))
+    return 0;
+
+  // Set up the creation routine for code-completion.
+  return new PrintingCodeCompleteConsumer(ShowMacros, ShowCodePatterns,
+                                          ShowGlobals, OS);
+}
+
+void CompilerInstance::createSema(TranslationUnitKind TUKind,
+                                  CodeCompleteConsumer *CompletionConsumer) {
+  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
+                         TUKind, CompletionConsumer));
+}
+
+// Output Files
+
+void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
+  assert(OutFile.OS && "Attempt to add empty stream to output list!");
+  OutputFiles.push_back(OutFile);
+}
+
+void CompilerInstance::clearOutputFiles(bool EraseFiles) {
+  for (std::list<OutputFile>::iterator
+         it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
+    delete it->OS;
+    if (!it->TempFilename.empty()) {
+      if (EraseFiles) {
+        bool existed;
+        llvm::sys::fs::remove(it->TempFilename, existed);
+      } else {
+        SmallString<128> NewOutFile(it->Filename);
+
+        // If '-working-directory' was passed, the output filename should be
+        // relative to that.
+        FileMgr->FixupRelativePath(NewOutFile);
+        if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
+                                                        NewOutFile.str())) {
+          getDiagnostics().Report(diag::err_fe_unable_to_rename_temp)
+            << it->TempFilename << it->Filename << ec.message();
+
+          bool existed;
+          llvm::sys::fs::remove(it->TempFilename, existed);
+        }
+      }
+    } else if (!it->Filename.empty() && EraseFiles)
+      llvm::sys::Path(it->Filename).eraseFromDisk();
+
+  }
+  OutputFiles.clear();
+}
+
+llvm::raw_fd_ostream *
+CompilerInstance::createDefaultOutputFile(bool Binary,
+                                          StringRef InFile,
+                                          StringRef Extension) {
+  return createOutputFile(getFrontendOpts().OutputFile, Binary,
+                          /*RemoveFileOnSignal=*/true, InFile, Extension,
+                          /*UseTemporary=*/true);
+}
+
+llvm::raw_fd_ostream *
+CompilerInstance::createOutputFile(StringRef OutputPath,
+                                   bool Binary, bool RemoveFileOnSignal,
+                                   StringRef InFile,
+                                   StringRef Extension,
+                                   bool UseTemporary,
+                                   bool CreateMissingDirectories) {
+  std::string Error, OutputPathName, TempPathName;
+  llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
+                                              RemoveFileOnSignal,
+                                              InFile, Extension,
+                                              UseTemporary,
+                                              CreateMissingDirectories,
+                                              &OutputPathName,
+                                              &TempPathName);
+  if (!OS) {
+    getDiagnostics().Report(diag::err_fe_unable_to_open_output)
+      << OutputPath << Error;
+    return 0;
+  }
+
+  // Add the output file -- but don't try to remove "-", since this means we are
+  // using stdin.
+  addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
+                TempPathName, OS));
+
+  return OS;
+}
+
+llvm::raw_fd_ostream *
+CompilerInstance::createOutputFile(StringRef OutputPath,
+                                   std::string &Error,
+                                   bool Binary,
+                                   bool RemoveFileOnSignal,
+                                   StringRef InFile,
+                                   StringRef Extension,
+                                   bool UseTemporary,
+                                   bool CreateMissingDirectories,
+                                   std::string *ResultPathName,
+                                   std::string *TempPathName) {
+  assert((!CreateMissingDirectories || UseTemporary) &&
+         "CreateMissingDirectories is only allowed when using temporary files");
+
+  std::string OutFile, TempFile;
+  if (!OutputPath.empty()) {
+    OutFile = OutputPath;
+  } else if (InFile == "-") {
+    OutFile = "-";
+  } else if (!Extension.empty()) {
+    llvm::sys::Path Path(InFile);
+    Path.eraseSuffix();
+    Path.appendSuffix(Extension);
+    OutFile = Path.str();
+  } else {
+    OutFile = "-";
+  }
+
+  OwningPtr<llvm::raw_fd_ostream> OS;
+  std::string OSFile;
+
+  if (UseTemporary && OutFile != "-") {
+    // Only create the temporary if the parent directory exists (or create
+    // missing directories is true) and we can actually write to OutPath,
+    // otherwise we want to fail early.
+    SmallString<256> AbsPath(OutputPath);
+    llvm::sys::fs::make_absolute(AbsPath);
+    llvm::sys::Path OutPath(AbsPath);
+    bool ParentExists = false;
+    if (llvm::sys::fs::exists(llvm::sys::path::parent_path(AbsPath.str()),
+                              ParentExists))
+      ParentExists = false;
+    bool Exists;
+    if ((CreateMissingDirectories || ParentExists) &&
+        ((llvm::sys::fs::exists(AbsPath.str(), Exists) || !Exists) ||
+         (OutPath.isRegularFile() && OutPath.canWrite()))) {
+      // Create a temporary file.
+      SmallString<128> TempPath;
+      TempPath = OutFile;
+      TempPath += "-%%%%%%%%";
+      int fd;
+      if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
+                               /*makeAbsolute=*/false) == llvm::errc::success) {
+        OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
+        OSFile = TempFile = TempPath.str();
+      }
+    }
+  }
+
+  if (!OS) {
+    OSFile = OutFile;
+    OS.reset(
+      new llvm::raw_fd_ostream(OSFile.c_str(), Error,
+                               (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
+    if (!Error.empty())
+      return 0;
+  }
+
+  // Make sure the out stream file gets removed if we crash.
+  if (RemoveFileOnSignal)
+    llvm::sys::RemoveFileOnSignal(llvm::sys::Path(OSFile));
+
+  if (ResultPathName)
+    *ResultPathName = OutFile;
+  if (TempPathName)
+    *TempPathName = TempFile;
+
+  return OS.take();
+}
+
+// Initialization Utilities
+
+bool CompilerInstance::InitializeSourceManager(StringRef InputFile,
+                                               SrcMgr::CharacteristicKind Kind){
+  return InitializeSourceManager(InputFile, Kind, getDiagnostics(), 
+                                 getFileManager(), getSourceManager(), 
+                                 getFrontendOpts());
+}
+
+bool CompilerInstance::InitializeSourceManager(StringRef InputFile,
+                                               SrcMgr::CharacteristicKind Kind,
+                                               DiagnosticsEngine &Diags,
+                                               FileManager &FileMgr,
+                                               SourceManager &SourceMgr,
+                                               const FrontendOptions &Opts) {
+  // Figure out where to get and map in the main file.
+  if (InputFile != "-") {
+    const FileEntry *File = FileMgr.getFile(InputFile);
+    if (!File) {
+      Diags.Report(diag::err_fe_error_reading) << InputFile;
+      return false;
+    }
+    SourceMgr.createMainFileID(File, Kind);
+  } else {
+    OwningPtr<llvm::MemoryBuffer> SB;
+    if (llvm::MemoryBuffer::getSTDIN(SB)) {
+      // FIXME: Give ec.message() in this diag.
+      Diags.Report(diag::err_fe_error_reading_stdin);
+      return false;
+    }
+    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
+                                                   SB->getBufferSize(), 0);
+    SourceMgr.createMainFileID(File, Kind);
+    SourceMgr.overrideFileContents(File, SB.take());
+  }
+
+  assert(!SourceMgr.getMainFileID().isInvalid() &&
+         "Couldn't establish MainFileID!");
+  return true;
+}
+
+// High-Level Operations
+
+bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
+  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
+  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
+  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
+
+  // FIXME: Take this as an argument, once all the APIs we used have moved to
+  // taking it as an input instead of hard-coding llvm::errs.
+  raw_ostream &OS = llvm::errs();
+
+  // Create the target instance.
+  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), getTargetOpts()));
+  if (!hasTarget())
+    return false;
+
+  // Inform the target of the language options.
+  //
+  // FIXME: We shouldn't need to do this, the target should be immutable once
+  // created. This complexity should be lifted elsewhere.
+  getTarget().setForcedLangOptions(getLangOpts());
+
+  // rewriter project will change target built-in bool type from its default. 
+  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
+    getTarget().noSignedCharForObjCBool();
+
+  // Validate/process some options.
+  if (getHeaderSearchOpts().Verbose)
+    OS << "clang -cc1 version " CLANG_VERSION_STRING
+       << " based upon " << PACKAGE_STRING
+       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
+
+  if (getFrontendOpts().ShowTimers)
+    createFrontendTimer();
+
+  if (getFrontendOpts().ShowStats)
+    llvm::EnableStatistics();
+
+  for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
+    // Reset the ID tables if we are reusing the SourceManager.
+    if (hasSourceManager())
+      getSourceManager().clearIDTables();
+
+    if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
+      Act.Execute();
+      Act.EndSourceFile();
+    }
+  }
+
+  // Notify the diagnostic client that all files were processed.
+  getDiagnostics().getClient()->finish();
+
+  if (getDiagnosticOpts().ShowCarets) {
+    // We can have multiple diagnostics sharing one diagnostic client.
+    // Get the total number of warnings/errors from the client.
+    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
+    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
+
+    if (NumWarnings)
+      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
+    if (NumWarnings && NumErrors)
+      OS << " and ";
+    if (NumErrors)
+      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
+    if (NumWarnings || NumErrors)
+      OS << " generated.\n";
+  }
+
+  if (getFrontendOpts().ShowStats && hasFileManager()) {
+    getFileManager().PrintStats();
+    OS << "\n";
+  }
+
+  return !getDiagnostics().getClient()->getNumErrors();
+}
+
+/// \brief Determine the appropriate source input kind based on language
+/// options.
+static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
+  if (LangOpts.OpenCL)
+    return IK_OpenCL;
+  if (LangOpts.CUDA)
+    return IK_CUDA;
+  if (LangOpts.ObjC1)
+    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
+  return LangOpts.CPlusPlus? IK_CXX : IK_C;
+}
+
+namespace {
+  struct CompileModuleMapData {
+    CompilerInstance &Instance;
+    GenerateModuleAction &CreateModuleAction;
+  };
+}
+
+/// \brief Helper function that executes the module-generating action under
+/// a crash recovery context.
+static void doCompileMapModule(void *UserData) {
+  CompileModuleMapData &Data
+    = *reinterpret_cast<CompileModuleMapData *>(UserData);
+  Data.Instance.ExecuteAction(Data.CreateModuleAction);
+}
+
+/// \brief Compile a module file for the given module, using the options 
+/// provided by the importing compiler instance.
+static void compileModule(CompilerInstance &ImportingInstance,
+                          Module *Module,
+                          StringRef ModuleFileName) {
+  llvm::LockFileManager Locked(ModuleFileName);
+  switch (Locked) {
+  case llvm::LockFileManager::LFS_Error:
+    return;
+
+  case llvm::LockFileManager::LFS_Owned:
+    // We're responsible for building the module ourselves. Do so below.
+    break;
+
+  case llvm::LockFileManager::LFS_Shared:
+    // Someone else is responsible for building the module. Wait for them to
+    // finish.
+    Locked.waitForUnlock();
+    break;
+  }
+
+  ModuleMap &ModMap 
+    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
+    
+  // Construct a compiler invocation for creating this module.
+  IntrusiveRefCntPtr<CompilerInvocation> Invocation
+    (new CompilerInvocation(ImportingInstance.getInvocation()));
+
+  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
+  
+  // For any options that aren't intended to affect how a module is built,
+  // reset them to their default values.
+  Invocation->getLangOpts()->resetNonModularOptions();
+  PPOpts.resetNonModularOptions();
+
+  // Note the name of the module we're building.
+  Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
+
+  // Note that this module is part of the module build path, so that we
+  // can detect cycles in the module graph.
+  PPOpts.ModuleBuildPath.push_back(Module->getTopLevelModuleName());
+
+  // If there is a module map file, build the module using the module map.
+  // Set up the inputs/outputs so that we build the module from its umbrella
+  // header.
+  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
+  FrontendOpts.OutputFile = ModuleFileName.str();
+  FrontendOpts.DisableFree = false;
+  FrontendOpts.Inputs.clear();
+  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
+
+  // Get or create the module map that we'll use to build this module.
+  SmallString<128> TempModuleMapFileName;
+  if (const FileEntry *ModuleMapFile
+                                  = ModMap.getContainingModuleMapFile(Module)) {
+    // Use the module map where this module resides.
+    FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(), 
+                                                    IK));
+  } else {
+    // Create a temporary module map file.
+    TempModuleMapFileName = Module->Name;
+    TempModuleMapFileName += "-%%%%%%%%.map";
+    int FD;
+    if (llvm::sys::fs::unique_file(TempModuleMapFileName.str(), FD, 
+                                   TempModuleMapFileName,
+                                   /*makeAbsolute=*/true)
+          != llvm::errc::success) {
+      ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
+        << TempModuleMapFileName;
+      return;
+    }
+    // Print the module map to this file.
+    llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
+    Module->print(OS);
+    FrontendOpts.Inputs.push_back(
+      FrontendInputFile(TempModuleMapFileName.str().str(), IK));
+  }
+
+  // Don't free the remapped file buffers; they are owned by our caller.
+  PPOpts.RetainRemappedFileBuffers = true;
+    
+  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
+  assert(ImportingInstance.getInvocation().getModuleHash() ==
+         Invocation->getModuleHash() && "Module hash mismatch!");
+  
+  // Construct a compiler instance that will be used to actually create the
+  // module.
+  CompilerInstance Instance;
+  Instance.setInvocation(&*Invocation);
+  Instance.createDiagnostics(/*argc=*/0, /*argv=*/0,
+                             &ImportingInstance.getDiagnosticClient(),
+                             /*ShouldOwnClient=*/true,
+                             /*ShouldCloneClient=*/true);
+  
+  // Construct a module-generating action.
+  GenerateModuleAction CreateModuleAction;
+  
+  // Execute the action to actually build the module in-place. Use a separate
+  // thread so that we get a stack large enough.
+  const unsigned ThreadStackSize = 8 << 20;
+  llvm::CrashRecoveryContext CRC;
+  CompileModuleMapData Data = { Instance, CreateModuleAction };
+  CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
+  
+  // Delete the temporary module map file.
+  // FIXME: Even though we're executing under crash protection, it would still
+  // be nice to do this with RemoveFileOnSignal when we can. However, that
+  // doesn't make sense for all clients, so clean this up manually.
+  if (!TempModuleMapFileName.empty())
+    llvm::sys::Path(TempModuleMapFileName).eraseFromDisk();
+}
+
+Module *CompilerInstance::loadModule(SourceLocation ImportLoc, 
+                                     ModuleIdPath Path,
+                                     Module::NameVisibilityKind Visibility,
+                                     bool IsInclusionDirective) {
+  // If we've already handled this import, just return the cached result.
+  // This one-element cache is important to eliminate redundant diagnostics
+  // when both the preprocessor and parser see the same import declaration.
+  if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
+    // Make the named module visible.
+    if (LastModuleImportResult)
+      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility);
+    return LastModuleImportResult;
+  }
+  
+  // Determine what file we're searching from.
+  SourceManager &SourceMgr = getSourceManager();
+  SourceLocation ExpandedImportLoc = SourceMgr.getExpansionLoc(ImportLoc);
+  const FileEntry *CurFile
+    = SourceMgr.getFileEntryForID(SourceMgr.getFileID(ExpandedImportLoc));
+  if (!CurFile)
+    CurFile = SourceMgr.getFileEntryForID(SourceMgr.getMainFileID());
+
+  StringRef ModuleName = Path[0].first->getName();
+  SourceLocation ModuleNameLoc = Path[0].second;
+
+  clang::Module *Module = 0;
+  
+  // If we don't already have information on this module, load the module now.
+  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
+    = KnownModules.find(Path[0].first);
+  if (Known != KnownModules.end()) {
+    // Retrieve the cached top-level module.
+    Module = Known->second;    
+  } else if (ModuleName == getLangOpts().CurrentModule) {
+    // This is the module we're building. 
+    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
+    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
+  } else {
+    // Search for a module with the given name.
+    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
+    std::string ModuleFileName;
+    if (Module)
+      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
+    else
+      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
+    
+    if (ModuleFileName.empty()) {
+      getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
+        << ModuleName
+        << SourceRange(ImportLoc, ModuleNameLoc);
+      LastModuleImportLoc = ImportLoc;
+      LastModuleImportResult = 0;
+      return 0;
+    }
+    
+    const FileEntry *ModuleFile
+      = getFileManager().getFile(ModuleFileName, /*OpenFile=*/false,
+                                 /*CacheFailure=*/false);
+    bool BuildingModule = false;
+    if (!ModuleFile && Module) {
+      // The module is not cached, but we have a module map from which we can
+      // build the module.
+
+      // Check whether there is a cycle in the module graph.
+      SmallVectorImpl<std::string> &ModuleBuildPath
+        = getPreprocessorOpts().ModuleBuildPath;
+      SmallVectorImpl<std::string>::iterator Pos
+        = std::find(ModuleBuildPath.begin(), ModuleBuildPath.end(), ModuleName);
+      if (Pos != ModuleBuildPath.end()) {
+        SmallString<256> CyclePath;
+        for (; Pos != ModuleBuildPath.end(); ++Pos) {
+          CyclePath += *Pos;
+          CyclePath += " -> ";
+        }
+        CyclePath += ModuleName;
+
+        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
+          << ModuleName << CyclePath;
+        return 0;
+      }
+
+      getDiagnostics().Report(ModuleNameLoc, diag::warn_module_build)
+        << ModuleName;
+      BuildingModule = true;
+      compileModule(*this, Module, ModuleFileName);
+      ModuleFile = FileMgr->getFile(ModuleFileName);
+    }
+
+    if (!ModuleFile) {
+      getDiagnostics().Report(ModuleNameLoc,
+                              BuildingModule? diag::err_module_not_built
+                                            : diag::err_module_not_found)
+        << ModuleName
+        << SourceRange(ImportLoc, ModuleNameLoc);
+      return 0;
+    }
+
+    // If we don't already have an ASTReader, create one now.
+    if (!ModuleManager) {
+      if (!hasASTContext())
+        createASTContext();
+
+      std::string Sysroot = getHeaderSearchOpts().Sysroot;
+      const PreprocessorOptions &PPOpts = getPreprocessorOpts();
+      ModuleManager = new ASTReader(getPreprocessor(), *Context,
+                                    Sysroot.empty() ? "" : Sysroot.c_str(),
+                                    PPOpts.DisablePCHValidation,
+                                    PPOpts.DisableStatCache);
+      if (hasASTConsumer()) {
+        ModuleManager->setDeserializationListener(
+          getASTConsumer().GetASTDeserializationListener());
+        getASTContext().setASTMutationListener(
+          getASTConsumer().GetASTMutationListener());
+      }
+      OwningPtr<ExternalASTSource> Source;
+      Source.reset(ModuleManager);
+      getASTContext().setExternalSource(Source);
+      if (hasSema())
+        ModuleManager->InitializeSema(getSema());
+      if (hasASTConsumer())
+        ModuleManager->StartTranslationUnit(&getASTConsumer());
+    }
+
+    // Try to load the module we found.
+    switch (ModuleManager->ReadAST(ModuleFile->getName(),
+                                   serialization::MK_Module)) {
+    case ASTReader::Success:
+      break;
+
+    case ASTReader::IgnorePCH:
+      // FIXME: The ASTReader will already have complained, but can we showhorn
+      // that diagnostic information into a more useful form?
+      KnownModules[Path[0].first] = 0;
+      return 0;
+
+    case ASTReader::Failure:
+      // Already complained, but note now that we failed.
+      KnownModules[Path[0].first] = 0;
+      return 0;
+    }
+    
+    if (!Module) {
+      // If we loaded the module directly, without finding a module map first,
+      // we'll have loaded the module's information from the module itself.
+      Module = PP->getHeaderSearchInfo().getModuleMap()
+                 .findModule((Path[0].first->getName()));
+    }
+    
+    // Cache the result of this top-level module lookup for later.
+    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
+  }
+  
+  // If we never found the module, fail.
+  if (!Module)
+    return 0;
+  
+  // Verify that the rest of the module path actually corresponds to
+  // a submodule.
+  if (Path.size() > 1) {
+    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
+      StringRef Name = Path[I].first->getName();
+      clang::Module *Sub = Module->findSubmodule(Name);
+      
+      if (!Sub) {
+        // Attempt to perform typo correction to find a module name that works.
+        llvm::SmallVector<StringRef, 2> Best;
+        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
+        
+        for (clang::Module::submodule_iterator J = Module->submodule_begin(), 
+                                            JEnd = Module->submodule_end();
+             J != JEnd; ++J) {
+          unsigned ED = Name.edit_distance((*J)->Name,
+                                           /*AllowReplacements=*/true,
+                                           BestEditDistance);
+          if (ED <= BestEditDistance) {
+            if (ED < BestEditDistance) {
+              Best.clear();
+              BestEditDistance = ED;
+            }
+            
+            Best.push_back((*J)->Name);
+          }
+        }
+        
+        // If there was a clear winner, user it.
+        if (Best.size() == 1) {
+          getDiagnostics().Report(Path[I].second, 
+                                  diag::err_no_submodule_suggest)
+            << Path[I].first << Module->getFullModuleName() << Best[0]
+            << SourceRange(Path[0].second, Path[I-1].second)
+            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
+                                            Best[0]);
+          
+          Sub = Module->findSubmodule(Best[0]);
+        }
+      }
+      
+      if (!Sub) {
+        // No submodule by this name. Complain, and don't look for further
+        // submodules.
+        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
+          << Path[I].first << Module->getFullModuleName()
+          << SourceRange(Path[0].second, Path[I-1].second);
+        break;
+      }
+      
+      Module = Sub;
+    }
+  }
+  
+  // Make the named module visible, if it's not already part of the module
+  // we are parsing.
+  if (ModuleName != getLangOpts().CurrentModule) {
+    if (!Module->IsFromModuleFile) {
+      // We have an umbrella header or directory that doesn't actually include
+      // all of the headers within the directory it covers. Complain about
+      // this missing submodule and recover by forgetting that we ever saw
+      // this submodule.
+      // FIXME: Should we detect this at module load time? It seems fairly
+      // expensive (and rare).
+      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
+        << Module->getFullModuleName()
+        << SourceRange(Path.front().second, Path.back().second);
+      
+      return 0;
+    }
+
+    // Check whether this module is available.
+    StringRef Feature;
+    if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
+      getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
+        << Module->getFullModuleName()
+        << Feature
+        << SourceRange(Path.front().second, Path.back().second);
+      LastModuleImportLoc = ImportLoc;
+      LastModuleImportResult = 0;
+      return 0;
+    }
+
+    ModuleManager->makeModuleVisible(Module, Visibility);
+  }
+  
+  // If this module import was due to an inclusion directive, create an 
+  // implicit import declaration to capture it in the AST.
+  if (IsInclusionDirective && hasASTContext()) {
+    TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
+    TU->addDecl(ImportDecl::CreateImplicit(getASTContext(), TU,
+                                           ImportLoc, Module, 
+                                           Path.back().second));
+  }
+  
+  LastModuleImportLoc = ImportLoc;
+  LastModuleImportResult = Module;
+  return Module;
+}
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
new file mode 100644
index 0000000..4c5b063
--- /dev/null
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -0,0 +1,2236 @@
+//===--- CompilerInvocation.cpp -------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/Version.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Driver/Arg.h"
+#include "clang/Driver/ArgList.h"
+#include "clang/Driver/CC1Options.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/OptTable.h"
+#include "clang/Driver/Option.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/LangStandard.h"
+#include "clang/Serialization/ASTReader.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/Path.h"
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// Initialization.
+//===----------------------------------------------------------------------===//
+
+CompilerInvocationBase::CompilerInvocationBase()
+  : LangOpts(new LangOptions()) {}
+
+CompilerInvocationBase::CompilerInvocationBase(const CompilerInvocationBase &X)
+  : RefCountedBase<CompilerInvocation>(),
+    LangOpts(new LangOptions(*X.getLangOpts())) {}
+
+//===----------------------------------------------------------------------===//
+// Utility functions.
+//===----------------------------------------------------------------------===//
+
+static const char *getAnalysisStoreName(AnalysisStores Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis store!");
+#define ANALYSIS_STORE(NAME, CMDFLAG, DESC, CREATFN) \
+  case NAME##Model: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+static const char *getAnalysisConstraintName(AnalysisConstraints Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis constraints!");
+#define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATFN) \
+  case NAME##Model: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+static const char *getAnalysisDiagClientName(AnalysisDiagClients Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis client!");
+#define ANALYSIS_DIAGNOSTICS(NAME, CMDFLAG, DESC, CREATFN, AUTOCREATE) \
+  case PD_##NAME: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+static const char *getAnalysisPurgeModeName(AnalysisPurgeMode Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis purge mode!");
+#define ANALYSIS_PURGE(NAME, CMDFLAG, DESC) \
+  case NAME: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+static const char *getAnalysisIPAModeName(AnalysisIPAMode Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis ipa mode!");
+#define ANALYSIS_IPA(NAME, CMDFLAG, DESC) \
+  case NAME: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+static const char *
+  getAnalysisInliningModeName(AnalysisInliningMode Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown analysis inlining mode!");
+#define ANALYSIS_INLINE_SELECTION(NAME, CMDFLAG, DESC) \
+  case NAME: return CMDFLAG;
+#include "clang/Frontend/Analyses.def"
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Serialization (to args)
+//===----------------------------------------------------------------------===//
+
+namespace {
+  /// ToArgsList - Helper class to create a list of std::strings.
+  class ToArgsList {
+    std::vector<std::string> &Res;
+  public:
+    explicit ToArgsList(std::vector<std::string> &Res) : Res(Res) {}
+
+    void push_back(StringRef Str) {
+      // Avoid creating a temporary string.
+      Res.push_back(std::string());
+      Res.back().assign(Str.data(), Str.size());
+    }
+
+    void push_back(StringRef Str1, StringRef Str2) {
+      push_back(Str1);
+      push_back(Str2);
+    }
+  };
+}
+
+static void AnalyzerOptsToArgs(const AnalyzerOptions &Opts, ToArgsList &Res) {
+  if (Opts.ShowCheckerHelp)
+    Res.push_back("-analyzer-checker-help");
+  if (Opts.AnalysisStoreOpt != RegionStoreModel)
+    Res.push_back("-analyzer-store",
+                  getAnalysisStoreName(Opts.AnalysisStoreOpt));
+  if (Opts.AnalysisConstraintsOpt != RangeConstraintsModel)
+    Res.push_back("-analyzer-constraints",
+                  getAnalysisConstraintName(Opts.AnalysisConstraintsOpt));
+  if (Opts.AnalysisDiagOpt != PD_HTML)
+    Res.push_back("-analyzer-output",
+                  getAnalysisDiagClientName(Opts.AnalysisDiagOpt));
+  if (Opts.AnalysisPurgeOpt != PurgeStmt)
+    Res.push_back("-analyzer-purge",
+                  getAnalysisPurgeModeName(Opts.AnalysisPurgeOpt));
+  if (!Opts.AnalyzeSpecificFunction.empty())
+    Res.push_back("-analyze-function", Opts.AnalyzeSpecificFunction);
+  if (Opts.IPAMode != Inlining)
+    Res.push_back("-analyzer-ipa", getAnalysisIPAModeName(Opts.IPAMode));
+  if (Opts.InliningMode != NoRedundancy)
+    Res.push_back("-analyzer-inlining-mode",
+                  getAnalysisInliningModeName(Opts.InliningMode));
+
+  if (Opts.AnalyzeAll)
+    Res.push_back("-analyzer-opt-analyze-headers");
+  if (Opts.AnalyzerDisplayProgress)
+    Res.push_back("-analyzer-display-progress");
+  if (Opts.AnalyzeNestedBlocks)
+    Res.push_back("-analyzer-opt-analyze-nested-blocks");
+  if (Opts.EagerlyAssume)
+    Res.push_back("-analyzer-eagerly-assume");
+  if (Opts.TrimGraph)
+    Res.push_back("-trim-egraph");
+  if (Opts.VisualizeEGDot)
+    Res.push_back("-analyzer-viz-egraph-graphviz");
+  if (Opts.VisualizeEGUbi)
+    Res.push_back("-analyzer-viz-egraph-ubigraph");
+  if (Opts.NoRetryExhausted)
+    Res.push_back("-analyzer-disable-retry-exhausted");
+
+  for (unsigned i = 0, e = Opts.CheckersControlList.size(); i != e; ++i) {
+    const std::pair<std::string, bool> &opt = Opts.CheckersControlList[i];
+    if (opt.second)
+      Res.push_back("-analyzer-disable-checker");
+    else
+      Res.push_back("-analyzer-checker");
+    Res.push_back(opt.first);
+  }
+}
+
+static void CodeGenOptsToArgs(const CodeGenOptions &Opts, ToArgsList &Res) {
+  if (Opts.DebugInfo)
+    Res.push_back("-g");
+  if (Opts.DisableLLVMOpts)
+    Res.push_back("-disable-llvm-optzns");
+  if (Opts.DisableRedZone)
+    Res.push_back("-disable-red-zone");
+  if (Opts.DisableTailCalls)
+    Res.push_back("-mdisable-tail-calls");
+  if (!Opts.DebugCompilationDir.empty())
+    Res.push_back("-fdebug-compilation-dir", Opts.DebugCompilationDir);
+  if (!Opts.DwarfDebugFlags.empty())
+    Res.push_back("-dwarf-debug-flags", Opts.DwarfDebugFlags);
+  if (Opts.ObjCRuntimeHasARC)
+    Res.push_back("-fobjc-runtime-has-arc");
+  if (Opts.ObjCRuntimeHasTerminate)
+    Res.push_back("-fobjc-runtime-has-terminate");
+  if (Opts.EmitGcovArcs)
+    Res.push_back("-femit-coverage-data");
+  if (Opts.EmitGcovNotes)
+    Res.push_back("-femit-coverage-notes");
+  if (!Opts.MergeAllConstants)
+    Res.push_back("-fno-merge-all-constants");
+  if (Opts.NoCommon)
+    Res.push_back("-fno-common");
+  if (Opts.ForbidGuardVariables)
+    Res.push_back("-fforbid-guard-variables");
+  if (Opts.UseRegisterSizedBitfieldAccess)
+    Res.push_back("-fuse-register-sized-bitfield-access");
+  if (Opts.NoImplicitFloat)
+    Res.push_back("-no-implicit-float");
+  if (Opts.OmitLeafFramePointer)
+    Res.push_back("-momit-leaf-frame-pointer");
+  if (Opts.OptimizeSize) {
+    assert(Opts.OptimizationLevel == 2 && "Invalid options!");
+    Opts.OptimizeSize == 1 ? Res.push_back("-Os") : Res.push_back("-Oz");
+  } else if (Opts.OptimizationLevel != 0)
+    Res.push_back("-O" + llvm::utostr(Opts.OptimizationLevel));
+  if (!Opts.MainFileName.empty())
+    Res.push_back("-main-file-name", Opts.MainFileName);
+  if (Opts.NoInfsFPMath)
+    Res.push_back("-menable-no-infinities");
+  if (Opts.NoNaNsFPMath)
+    Res.push_back("-menable-no-nans");
+  // SimplifyLibCalls is only derived.
+  // TimePasses is only derived.
+  // UnitAtATime is unused.
+  // Inlining is only derived.
+
+  // UnrollLoops is derived, but also accepts an option, no
+  // harm in pushing it back here.
+  if (Opts.UnrollLoops)
+    Res.push_back("-funroll-loops");
+  if (Opts.DataSections)
+    Res.push_back("-fdata-sections");
+  if (Opts.FunctionSections)
+    Res.push_back("-ffunction-sections");
+  if (Opts.AsmVerbose)
+    Res.push_back("-masm-verbose");
+  if (!Opts.CodeModel.empty())
+    Res.push_back("-mcode-model", Opts.CodeModel);
+  if (Opts.CUDAIsDevice)
+    Res.push_back("-fcuda-is-device");
+  if (!Opts.CXAAtExit)
+    Res.push_back("-fno-use-cxa-atexit");
+  if (Opts.CXXCtorDtorAliases)
+    Res.push_back("-mconstructor-aliases");
+  if (Opts.ObjCAutoRefCountExceptions)
+    Res.push_back("-fobjc-arc-eh");
+  if (!Opts.DebugPass.empty()) {
+    Res.push_back("-mdebug-pass", Opts.DebugPass);
+  }
+  if (Opts.DisableFPElim)
+    Res.push_back("-mdisable-fp-elim");
+  if (!Opts.FloatABI.empty())
+    Res.push_back("-mfloat-abi", Opts.FloatABI);
+  if (!Opts.LimitFloatPrecision.empty())
+    Res.push_back("-mlimit-float-precision", Opts.LimitFloatPrecision);
+  if (Opts.NoZeroInitializedInBSS)
+    Res.push_back("-mno-zero-initialized-bss");
+  switch (Opts.getObjCDispatchMethod()) {
+  case CodeGenOptions::Legacy:
+    break;
+  case CodeGenOptions::Mixed:
+    Res.push_back("-fobjc-dispatch-method=mixed");
+    break;
+  case CodeGenOptions::NonLegacy:
+    Res.push_back("-fobjc-dispatch-method=non-legacy");
+    break;
+  }
+  if (Opts.NumRegisterParameters)
+    Res.push_back("-mregparm", llvm::utostr(Opts.NumRegisterParameters));
+  if (Opts.NoGlobalMerge)
+    Res.push_back("-mno-global-merge");
+  if (Opts.NoExecStack)
+    Res.push_back("-mnoexecstack");
+  if (Opts.RelaxAll)
+    Res.push_back("-mrelax-all");
+  if (Opts.SaveTempLabels)
+    Res.push_back("-msave-temp-labels");
+  if (Opts.NoDwarf2CFIAsm)
+    Res.push_back("-fno-dwarf2-cfi-asm");
+  if (Opts.NoDwarfDirectoryAsm)
+    Res.push_back("-fno-dwarf-directory-asm");
+  if (Opts.SoftFloat)
+    Res.push_back("-msoft-float");
+  if (Opts.StrictEnums)
+    Res.push_back("-fstrict-enums");
+  if (Opts.UnwindTables)
+    Res.push_back("-munwind-tables");
+  if (Opts.RelocationModel != "pic")
+    Res.push_back("-mrelocation-model", Opts.RelocationModel);
+  if (!Opts.VerifyModule)
+    Res.push_back("-disable-llvm-verifier");
+  for (unsigned i = 0, e = Opts.BackendOptions.size(); i != e; ++i)
+    Res.push_back("-backend-option", Opts.BackendOptions[i]);
+}
+
+static void DependencyOutputOptsToArgs(const DependencyOutputOptions &Opts,
+                                       ToArgsList &Res) {
+  if (Opts.IncludeSystemHeaders)
+    Res.push_back("-sys-header-deps");
+  if (Opts.ShowHeaderIncludes)
+    Res.push_back("-H");
+  if (!Opts.HeaderIncludeOutputFile.empty())
+    Res.push_back("-header-include-file", Opts.HeaderIncludeOutputFile);
+  if (Opts.UsePhonyTargets)
+    Res.push_back("-MP");
+  if (!Opts.OutputFile.empty())
+    Res.push_back("-dependency-file", Opts.OutputFile);
+  for (unsigned i = 0, e = Opts.Targets.size(); i != e; ++i)
+    Res.push_back("-MT", Opts.Targets[i]);
+}
+
+static void DiagnosticOptsToArgs(const DiagnosticOptions &Opts,
+                                 ToArgsList &Res) {
+  if (Opts.IgnoreWarnings)
+    Res.push_back("-w");
+  if (Opts.NoRewriteMacros)
+    Res.push_back("-Wno-rewrite-macros");
+  if (Opts.Pedantic)
+    Res.push_back("-pedantic");
+  if (Opts.PedanticErrors)
+    Res.push_back("-pedantic-errors");
+  if (!Opts.ShowColumn)
+    Res.push_back("-fno-show-column");
+  if (!Opts.ShowLocation)
+    Res.push_back("-fno-show-source-location");
+  if (!Opts.ShowCarets)
+    Res.push_back("-fno-caret-diagnostics");
+  if (!Opts.ShowFixits)
+    Res.push_back("-fno-diagnostics-fixit-info");
+  if (Opts.ShowSourceRanges)
+    Res.push_back("-fdiagnostics-print-source-range-info");
+  if (Opts.ShowParseableFixits)
+    Res.push_back("-fdiagnostics-parseable-fixits");
+  if (Opts.ShowColors)
+    Res.push_back("-fcolor-diagnostics");
+  if (Opts.VerifyDiagnostics)
+    Res.push_back("-verify");
+  if (Opts.ShowOptionNames)
+    Res.push_back("-fdiagnostics-show-option");
+  if (Opts.ShowCategories == 1)
+    Res.push_back("-fdiagnostics-show-category=id");
+  else if (Opts.ShowCategories == 2)
+    Res.push_back("-fdiagnostics-show-category=name");
+  switch (Opts.Format) {
+  case DiagnosticOptions::Clang: 
+    Res.push_back("-fdiagnostics-format=clang"); break;
+  case DiagnosticOptions::Msvc:  
+    Res.push_back("-fdiagnostics-format=msvc");  break;
+  case DiagnosticOptions::Vi:    
+    Res.push_back("-fdiagnostics-format=vi");    break;
+  }
+  if (Opts.ErrorLimit)
+    Res.push_back("-ferror-limit", llvm::utostr(Opts.ErrorLimit));
+  if (!Opts.DiagnosticLogFile.empty())
+    Res.push_back("-diagnostic-log-file", Opts.DiagnosticLogFile);
+  if (Opts.MacroBacktraceLimit
+                        != DiagnosticOptions::DefaultMacroBacktraceLimit)
+    Res.push_back("-fmacro-backtrace-limit",
+                  llvm::utostr(Opts.MacroBacktraceLimit));
+  if (Opts.TemplateBacktraceLimit
+                        != DiagnosticOptions::DefaultTemplateBacktraceLimit)
+    Res.push_back("-ftemplate-backtrace-limit",
+                  llvm::utostr(Opts.TemplateBacktraceLimit));
+  if (Opts.ConstexprBacktraceLimit
+                        != DiagnosticOptions::DefaultConstexprBacktraceLimit)
+    Res.push_back("-fconstexpr-backtrace-limit",
+                  llvm::utostr(Opts.ConstexprBacktraceLimit));
+
+  if (Opts.TabStop != DiagnosticOptions::DefaultTabStop)
+    Res.push_back("-ftabstop", llvm::utostr(Opts.TabStop));
+  if (Opts.MessageLength)
+    Res.push_back("-fmessage-length", llvm::utostr(Opts.MessageLength));
+  if (!Opts.DumpBuildInformation.empty())
+    Res.push_back("-dump-build-information", Opts.DumpBuildInformation);
+  for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i)
+    Res.push_back("-W" + Opts.Warnings[i]);
+}
+
+static const char *getInputKindName(InputKind Kind) {
+  switch (Kind) {
+  case IK_None:              break;
+  case IK_AST:               return "ast";
+  case IK_Asm:               return "assembler-with-cpp";
+  case IK_C:                 return "c";
+  case IK_CXX:               return "c++";
+  case IK_LLVM_IR:           return "ir";
+  case IK_ObjC:              return "objective-c";
+  case IK_ObjCXX:            return "objective-c++";
+  case IK_OpenCL:            return "cl";
+  case IK_CUDA:              return "cuda";
+  case IK_PreprocessedC:     return "cpp-output";
+  case IK_PreprocessedCXX:   return "c++-cpp-output";
+  case IK_PreprocessedObjC:  return "objective-c-cpp-output";
+  case IK_PreprocessedObjCXX:return "objective-c++-cpp-output";
+  }
+
+  llvm_unreachable("Unexpected language kind!");
+}
+
+static const char *getActionName(frontend::ActionKind Kind) {
+  switch (Kind) {
+  case frontend::PluginAction:
+    llvm_unreachable("Invalid kind!");
+
+  case frontend::ASTDump:                return "-ast-dump";
+  case frontend::ASTDumpXML:             return "-ast-dump-xml";
+  case frontend::ASTPrint:               return "-ast-print";
+  case frontend::ASTView:                return "-ast-view";
+  case frontend::DumpRawTokens:          return "-dump-raw-tokens";
+  case frontend::DumpTokens:             return "-dump-tokens";
+  case frontend::EmitAssembly:           return "-S";
+  case frontend::EmitBC:                 return "-emit-llvm-bc";
+  case frontend::EmitHTML:               return "-emit-html";
+  case frontend::EmitLLVM:               return "-emit-llvm";
+  case frontend::EmitLLVMOnly:           return "-emit-llvm-only";
+  case frontend::EmitCodeGenOnly:        return "-emit-codegen-only";
+  case frontend::EmitObj:                return "-emit-obj";
+  case frontend::FixIt:                  return "-fixit";
+  case frontend::GenerateModule:         return "-emit-module";
+  case frontend::GeneratePCH:            return "-emit-pch";
+  case frontend::GeneratePTH:            return "-emit-pth";
+  case frontend::InitOnly:               return "-init-only";
+  case frontend::ParseSyntaxOnly:        return "-fsyntax-only";
+  case frontend::PrintDeclContext:       return "-print-decl-contexts";
+  case frontend::PrintPreamble:          return "-print-preamble";
+  case frontend::PrintPreprocessedInput: return "-E";
+  case frontend::RewriteMacros:          return "-rewrite-macros";
+  case frontend::RewriteObjC:            return "-rewrite-objc";
+  case frontend::RewriteTest:            return "-rewrite-test";
+  case frontend::RunAnalysis:            return "-analyze";
+  case frontend::MigrateSource:          return "-migrate";
+  case frontend::RunPreprocessorOnly:    return "-Eonly";
+  }
+
+  llvm_unreachable("Unexpected language kind!");
+}
+
+static void FileSystemOptsToArgs(const FileSystemOptions &Opts, ToArgsList &Res){
+  if (!Opts.WorkingDir.empty())
+    Res.push_back("-working-directory", Opts.WorkingDir);
+}
+
+static void FrontendOptsToArgs(const FrontendOptions &Opts, ToArgsList &Res) {
+  if (Opts.DisableFree)
+    Res.push_back("-disable-free");
+  if (Opts.RelocatablePCH)
+    Res.push_back("-relocatable-pch");
+  if (Opts.ShowHelp)
+    Res.push_back("-help");
+  if (Opts.ShowMacrosInCodeCompletion)
+    Res.push_back("-code-completion-macros");
+  if (Opts.ShowCodePatternsInCodeCompletion)
+    Res.push_back("-code-completion-patterns");
+  if (!Opts.ShowGlobalSymbolsInCodeCompletion)
+    Res.push_back("-no-code-completion-globals");
+  if (Opts.ShowStats)
+    Res.push_back("-print-stats");
+  if (Opts.ShowTimers)
+    Res.push_back("-ftime-report");
+  if (Opts.ShowVersion)
+    Res.push_back("-version");
+  if (Opts.FixWhatYouCan)
+    Res.push_back("-fix-what-you-can");
+  if (Opts.FixOnlyWarnings)
+    Res.push_back("-fix-only-warnings");
+  if (Opts.FixAndRecompile)
+    Res.push_back("-fixit-recompile");
+  if (Opts.FixToTemporaries)
+    Res.push_back("-fixit-to-temporary");
+  switch (Opts.ARCMTAction) {
+  case FrontendOptions::ARCMT_None:
+    break;
+  case FrontendOptions::ARCMT_Check:
+    Res.push_back("-arcmt-check");
+    break;
+  case FrontendOptions::ARCMT_Modify:
+    Res.push_back("-arcmt-modify");
+    break;
+  case FrontendOptions::ARCMT_Migrate:
+    Res.push_back("-arcmt-migrate");
+    break;
+  }
+  if (!Opts.MTMigrateDir.empty())
+    Res.push_back("-mt-migrate-directory", Opts.MTMigrateDir);
+  if (!Opts.ARCMTMigrateReportOut.empty())
+    Res.push_back("-arcmt-migrate-report-output", Opts.ARCMTMigrateReportOut);
+  if (Opts.ARCMTMigrateEmitARCErrors)
+    Res.push_back("-arcmt-migrate-emit-errors");
+
+  if (Opts.ObjCMTAction & ~FrontendOptions::ObjCMT_Literals)
+    Res.push_back("-objcmt-migrate-literals");
+  if (Opts.ObjCMTAction & ~FrontendOptions::ObjCMT_Subscripting)
+    Res.push_back("-objcmt-migrate-subscripting");
+
+  bool NeedLang = false;
+  for (unsigned i = 0, e = Opts.Inputs.size(); i != e; ++i)
+    if (FrontendOptions::getInputKindForExtension(Opts.Inputs[i].File) !=
+        Opts.Inputs[i].Kind)
+      NeedLang = true;
+  if (NeedLang)
+    Res.push_back("-x", getInputKindName(Opts.Inputs[0].Kind));
+  for (unsigned i = 0, e = Opts.Inputs.size(); i != e; ++i) {
+    assert((!NeedLang || Opts.Inputs[i].Kind == Opts.Inputs[0].Kind) &&
+           "Unable to represent this input vector!");
+    Res.push_back(Opts.Inputs[i].File);
+  }
+
+  if (!Opts.OutputFile.empty())
+    Res.push_back("-o", Opts.OutputFile);
+  if (!Opts.CodeCompletionAt.FileName.empty())
+    Res.push_back("-code-completion-at",
+                  Opts.CodeCompletionAt.FileName + ":" +
+                  llvm::utostr(Opts.CodeCompletionAt.Line) + ":" +
+                  llvm::utostr(Opts.CodeCompletionAt.Column));
+  if (Opts.ProgramAction != frontend::PluginAction)
+    Res.push_back(getActionName(Opts.ProgramAction));
+  if (!Opts.ActionName.empty()) {
+    Res.push_back("-plugin", Opts.ActionName);
+    for(unsigned i = 0, e = Opts.PluginArgs.size(); i != e; ++i)
+      Res.push_back("-plugin-arg-" + Opts.ActionName, Opts.PluginArgs[i]);
+  }
+  for (unsigned i = 0, e = Opts.Plugins.size(); i != e; ++i)
+    Res.push_back("-load", Opts.Plugins[i]);
+  for (unsigned i = 0, e = Opts.AddPluginActions.size(); i != e; ++i) {
+    Res.push_back("-add-plugin", Opts.AddPluginActions[i]);
+    for(unsigned ai = 0, ae = Opts.AddPluginArgs.size(); ai != ae; ++ai)
+      Res.push_back("-plugin-arg-" + Opts.AddPluginActions[i],
+                    Opts.AddPluginArgs[i][ai]);
+  }
+  for (unsigned i = 0, e = Opts.ASTMergeFiles.size(); i != e; ++i)
+    Res.push_back("-ast-merge", Opts.ASTMergeFiles[i]);
+  for (unsigned i = 0, e = Opts.LLVMArgs.size(); i != e; ++i)
+    Res.push_back("-mllvm", Opts.LLVMArgs[i]);
+  if (!Opts.OverrideRecordLayoutsFile.empty())
+    Res.push_back("-foverride-record-layout=" + Opts.OverrideRecordLayoutsFile);
+}
+
+static void HeaderSearchOptsToArgs(const HeaderSearchOptions &Opts,
+                                   ToArgsList &Res) {
+  if (Opts.Sysroot != "/") {
+    Res.push_back("-isysroot");
+    Res.push_back(Opts.Sysroot);
+  }
+
+  /// User specified include entries.
+  for (unsigned i = 0, e = Opts.UserEntries.size(); i != e; ++i) {
+    const HeaderSearchOptions::Entry &E = Opts.UserEntries[i];
+    if (E.IsFramework && (E.Group != frontend::Angled || !E.IsUserSupplied))
+      llvm::report_fatal_error("Invalid option set!");
+    if (E.IsUserSupplied) {
+      switch (E.Group) {
+      case frontend::After:
+        Res.push_back("-idirafter");
+        break;
+        
+      case frontend::Quoted:
+        Res.push_back("-iquote");
+        break;
+        
+      case frontend::System:
+        Res.push_back("-isystem");
+        break;
+        
+      case frontend::IndexHeaderMap:
+        Res.push_back("-index-header-map");
+        Res.push_back(E.IsFramework? "-F" : "-I");
+        break;
+        
+      case frontend::CSystem:
+        Res.push_back("-c-isystem");
+        break;
+
+      case frontend::CXXSystem:
+        Res.push_back("-cxx-isystem");
+        break;
+
+      case frontend::ObjCSystem:
+        Res.push_back("-objc-isystem");
+        break;
+
+      case frontend::ObjCXXSystem:
+        Res.push_back("-objcxx-isystem");
+        break;
+        
+      case frontend::Angled:
+        Res.push_back(E.IsFramework ? "-F" : "-I");
+        break;
+      }
+    } else {
+      if (E.IsInternal) {
+        assert(E.Group == frontend::System && "Unexpected header search group");
+        if (E.ImplicitExternC)
+          Res.push_back("-internal-externc-isystem");
+        else
+          Res.push_back("-internal-isystem");
+      } else {
+        if (E.Group != frontend::Angled && E.Group != frontend::System)
+          llvm::report_fatal_error("Invalid option set!");
+        Res.push_back(E.Group == frontend::Angled ? "-iwithprefixbefore" :
+                      "-iwithprefix");
+      }
+    }
+    Res.push_back(E.Path);
+  }
+
+  if (!Opts.ResourceDir.empty())
+    Res.push_back("-resource-dir", Opts.ResourceDir);
+  if (!Opts.ModuleCachePath.empty())
+    Res.push_back("-fmodule-cache-path", Opts.ModuleCachePath);
+  if (!Opts.UseStandardSystemIncludes)
+    Res.push_back("-nostdsysteminc");
+  if (!Opts.UseStandardCXXIncludes)
+    Res.push_back("-nostdinc++");
+  if (Opts.UseLibcxx)
+    Res.push_back("-stdlib=libc++");
+  if (Opts.Verbose)
+    Res.push_back("-v");
+}
+
+static void LangOptsToArgs(const LangOptions &Opts, ToArgsList &Res) {
+  LangOptions DefaultLangOpts;
+
+  // FIXME: Need to set -std to get all the implicit options.
+
+  // FIXME: We want to only pass options relative to the defaults, which
+  // requires constructing a target. :(
+  //
+  // It would be better to push the all target specific choices into the driver,
+  // so that everything below that was more uniform.
+
+  if (Opts.Trigraphs)
+    Res.push_back("-trigraphs");
+  // Implicit based on the input kind:
+  //   AsmPreprocessor, CPlusPlus, ObjC1, ObjC2, OpenCL
+  // Implicit based on the input language standard:
+  //   BCPLComment, C99, CPlusPlus0x, Digraphs, GNUInline, ImplicitInt, GNUMode
+  if (Opts.DollarIdents)
+    Res.push_back("-fdollars-in-identifiers");
+  if (Opts.GNUMode && !Opts.GNUKeywords)
+    Res.push_back("-fno-gnu-keywords");
+  if (!Opts.GNUMode && Opts.GNUKeywords)
+    Res.push_back("-fgnu-keywords");
+  if (Opts.MicrosoftExt)
+    Res.push_back("-fms-extensions");
+  if (Opts.MicrosoftMode)
+    Res.push_back("-fms-compatibility");
+  if (Opts.MSCVersion != 0)
+    Res.push_back("-fmsc-version=" + llvm::utostr(Opts.MSCVersion));
+  if (Opts.Borland)
+    Res.push_back("-fborland-extensions");
+  if (!Opts.ObjCNonFragileABI)
+    Res.push_back("-fobjc-fragile-abi");
+  if (Opts.ObjCDefaultSynthProperties)
+    Res.push_back("-fobjc-default-synthesize-properties");
+  // NoInline is implicit.
+  if (!Opts.CXXOperatorNames)
+    Res.push_back("-fno-operator-names");
+  if (Opts.PascalStrings)
+    Res.push_back("-fpascal-strings");
+  if (Opts.CatchUndefined)
+    Res.push_back("-fcatch-undefined-behavior");
+  if (Opts.AddressSanitizer)
+    Res.push_back("-faddress-sanitizer");
+  if (Opts.ThreadSanitizer)
+    Res.push_back("-fthread-sanitizer");
+  if (Opts.WritableStrings)
+    Res.push_back("-fwritable-strings");
+  if (Opts.ConstStrings)
+    Res.push_back("-fconst-strings");
+  if (!Opts.LaxVectorConversions)
+    Res.push_back("-fno-lax-vector-conversions");
+  if (Opts.AltiVec)
+    Res.push_back("-faltivec");
+  if (Opts.Exceptions)
+    Res.push_back("-fexceptions");
+  if (Opts.ObjCExceptions)
+    Res.push_back("-fobjc-exceptions");
+  if (Opts.CXXExceptions)
+    Res.push_back("-fcxx-exceptions");
+  if (Opts.SjLjExceptions)
+    Res.push_back("-fsjlj-exceptions");
+  if (Opts.TraditionalCPP)
+    Res.push_back("-traditional-cpp");
+  if (!Opts.RTTI)
+    Res.push_back("-fno-rtti");
+  if (Opts.MSBitfields)
+    Res.push_back("-mms-bitfields");
+  if (!Opts.NeXTRuntime)
+    Res.push_back("-fgnu-runtime");
+  if (Opts.Freestanding)
+    Res.push_back("-ffreestanding");
+  if (Opts.NoBuiltin)
+    Res.push_back("-fno-builtin");
+  if (!Opts.AssumeSaneOperatorNew)
+    Res.push_back("-fno-assume-sane-operator-new");
+  if (!Opts.ThreadsafeStatics)
+    Res.push_back("-fno-threadsafe-statics");
+  if (Opts.POSIXThreads)
+    Res.push_back("-pthread");
+  if (Opts.Blocks)
+    Res.push_back("-fblocks");
+  if (Opts.BlocksRuntimeOptional)
+    Res.push_back("-fblocks-runtime-optional");
+  if (Opts.Modules)
+    Res.push_back("-fmodules");
+  if (Opts.EmitAllDecls)
+    Res.push_back("-femit-all-decls");
+  if (Opts.MathErrno)
+    Res.push_back("-fmath-errno");
+  switch (Opts.getSignedOverflowBehavior()) {
+  case LangOptions::SOB_Undefined: break;
+  case LangOptions::SOB_Defined:   Res.push_back("-fwrapv"); break;
+  case LangOptions::SOB_Trapping:
+    Res.push_back("-ftrapv");
+    if (!Opts.OverflowHandler.empty())
+      Res.push_back("-ftrapv-handler", Opts.OverflowHandler);
+    break;
+  }
+  if (Opts.HeinousExtensions)
+    Res.push_back("-fheinous-gnu-extensions");
+  // Optimize is implicit.
+  // OptimizeSize is implicit.
+  if (Opts.FastMath)
+    Res.push_back("-ffast-math");
+  if (Opts.Static)
+    Res.push_back("-static-define");
+  if (Opts.DumpRecordLayoutsSimple)
+    Res.push_back("-fdump-record-layouts-simple");
+  else if (Opts.DumpRecordLayouts)
+    Res.push_back("-fdump-record-layouts");
+  if (Opts.DumpVTableLayouts)
+    Res.push_back("-fdump-vtable-layouts");
+  if (Opts.NoBitFieldTypeAlign)
+    Res.push_back("-fno-bitfield-type-alignment");
+  if (Opts.PICLevel)
+    Res.push_back("-pic-level", llvm::utostr(Opts.PICLevel));
+  if (Opts.PIELevel)
+    Res.push_back("-pie-level", llvm::utostr(Opts.PIELevel));
+  if (Opts.ObjCGCBitmapPrint)
+    Res.push_back("-print-ivar-layout");
+  if (Opts.NoConstantCFStrings)
+    Res.push_back("-fno-constant-cfstrings");
+  if (!Opts.AccessControl)
+    Res.push_back("-fno-access-control");
+  if (!Opts.CharIsSigned)
+    Res.push_back("-fno-signed-char");
+  if (Opts.ShortWChar)
+    Res.push_back("-fshort-wchar");
+  if (!Opts.ElideConstructors)
+    Res.push_back("-fno-elide-constructors");
+  if (Opts.getGC() != LangOptions::NonGC) {
+    if (Opts.getGC() == LangOptions::HybridGC) {
+      Res.push_back("-fobjc-gc");
+    } else {
+      assert(Opts.getGC() == LangOptions::GCOnly && "Invalid GC mode!");
+      Res.push_back("-fobjc-gc-only");
+    }
+  }
+  if (Opts.ObjCAutoRefCount)
+    Res.push_back("-fobjc-arc");
+  if (Opts.ObjCRuntimeHasWeak)
+    Res.push_back("-fobjc-runtime-has-weak");
+  if (!Opts.ObjCInferRelatedResultType)
+    Res.push_back("-fno-objc-infer-related-result-type");
+  
+  if (Opts.AppleKext)
+    Res.push_back("-fapple-kext");
+  
+  if (Opts.getVisibilityMode() != DefaultVisibility) {
+    Res.push_back("-fvisibility");
+    if (Opts.getVisibilityMode() == HiddenVisibility) {
+      Res.push_back("hidden");
+    } else {
+      assert(Opts.getVisibilityMode() == ProtectedVisibility &&
+             "Invalid visibility!");
+      Res.push_back("protected");
+    }
+  }
+  if (Opts.InlineVisibilityHidden)
+    Res.push_back("-fvisibility-inlines-hidden");
+
+  if (Opts.getStackProtector() != 0)
+    Res.push_back("-stack-protector", llvm::utostr(Opts.getStackProtector()));
+  if (Opts.InstantiationDepth != DefaultLangOpts.InstantiationDepth)
+    Res.push_back("-ftemplate-depth", llvm::utostr(Opts.InstantiationDepth));
+  if (Opts.ConstexprCallDepth != DefaultLangOpts.ConstexprCallDepth)
+    Res.push_back("-fconstexpr-depth", llvm::utostr(Opts.ConstexprCallDepth));
+  if (!Opts.ObjCConstantStringClass.empty())
+    Res.push_back("-fconstant-string-class", Opts.ObjCConstantStringClass);
+  if (Opts.FakeAddressSpaceMap)
+    Res.push_back("-ffake-address-space-map");
+  if (Opts.ParseUnknownAnytype)
+    Res.push_back("-funknown-anytype");
+  if (Opts.DebuggerSupport)
+    Res.push_back("-fdebugger-support");
+  if (Opts.DebuggerCastResultToId)
+    Res.push_back("-fdebugger-cast-result-to-id");
+  if (Opts.DebuggerObjCLiteral)
+    Res.push_back("-fdebugger-objc-literal");
+  if (Opts.DelayedTemplateParsing)
+    Res.push_back("-fdelayed-template-parsing");
+  if (Opts.Deprecated)
+    Res.push_back("-fdeprecated-macro");
+  if (Opts.ApplePragmaPack)
+    Res.push_back("-fapple-pragma-pack");
+  if (!Opts.CurrentModule.empty())
+    Res.push_back("-fmodule-name=" + Opts.CurrentModule);
+}
+
+static void PreprocessorOptsToArgs(const PreprocessorOptions &Opts,
+                                   ToArgsList &Res) {
+  for (unsigned i = 0, e = Opts.Macros.size(); i != e; ++i)
+    Res.push_back(std::string(Opts.Macros[i].second ? "-U" : "-D") +
+                  Opts.Macros[i].first);
+  for (unsigned i = 0, e = Opts.Includes.size(); i != e; ++i) {
+    // FIXME: We need to avoid reincluding the implicit PCH and PTH includes.
+    Res.push_back("-include", Opts.Includes[i]);
+  }
+  for (unsigned i = 0, e = Opts.MacroIncludes.size(); i != e; ++i)
+    Res.push_back("-imacros", Opts.MacroIncludes[i]);
+  if (!Opts.UsePredefines)
+    Res.push_back("-undef");
+  if (Opts.DetailedRecord)
+    Res.push_back("-detailed-preprocessing-record");
+  if (!Opts.ImplicitPCHInclude.empty())
+    Res.push_back("-include-pch", Opts.ImplicitPCHInclude);
+  if (!Opts.ImplicitPTHInclude.empty())
+    Res.push_back("-include-pth", Opts.ImplicitPTHInclude);
+  if (!Opts.TokenCache.empty()) {
+    if (Opts.ImplicitPTHInclude.empty())
+      Res.push_back("-token-cache", Opts.TokenCache);
+    else
+      assert(Opts.ImplicitPTHInclude == Opts.TokenCache &&
+             "Unsupported option combination!");
+  }
+  for (unsigned i = 0, e = Opts.ChainedIncludes.size(); i != e; ++i)
+    Res.push_back("-chain-include", Opts.ChainedIncludes[i]);
+  for (unsigned i = 0, e = Opts.RemappedFiles.size(); i != e; ++i) {
+    Res.push_back("-remap-file", Opts.RemappedFiles[i].first + ";" +
+                                 Opts.RemappedFiles[i].second);
+  }
+}
+
+static void PreprocessorOutputOptsToArgs(const PreprocessorOutputOptions &Opts,
+                                         ToArgsList &Res) {
+  if (!Opts.ShowCPP && !Opts.ShowMacros)
+    llvm::report_fatal_error("Invalid option combination!");
+
+  if (Opts.ShowCPP && Opts.ShowMacros)
+    Res.push_back("-dD");
+  else if (!Opts.ShowCPP && Opts.ShowMacros)
+    Res.push_back("-dM");
+
+  if (!Opts.ShowLineMarkers)
+    Res.push_back("-P");
+  if (Opts.ShowComments)
+    Res.push_back("-C");
+  if (Opts.ShowMacroComments)
+    Res.push_back("-CC");
+}
+
+static void TargetOptsToArgs(const TargetOptions &Opts,
+                             ToArgsList &Res) {
+  Res.push_back("-triple");
+  Res.push_back(Opts.Triple);
+  if (!Opts.CPU.empty())
+    Res.push_back("-target-cpu", Opts.CPU);
+  if (!Opts.ABI.empty())
+    Res.push_back("-target-abi", Opts.ABI);
+  if (!Opts.LinkerVersion.empty())
+    Res.push_back("-target-linker-version", Opts.LinkerVersion);
+  if (!Opts.CXXABI.empty())
+    Res.push_back("-cxx-abi", Opts.CXXABI);
+  for (unsigned i = 0, e = Opts.Features.size(); i != e; ++i)
+    Res.push_back("-target-feature", Opts.Features[i]);
+}
+
+void CompilerInvocation::toArgs(std::vector<std::string> &Res) {
+  ToArgsList List(Res);
+  AnalyzerOptsToArgs(getAnalyzerOpts(), List);
+  CodeGenOptsToArgs(getCodeGenOpts(), List);
+  DependencyOutputOptsToArgs(getDependencyOutputOpts(), List);
+  DiagnosticOptsToArgs(getDiagnosticOpts(), List);
+  FileSystemOptsToArgs(getFileSystemOpts(), List);
+  FrontendOptsToArgs(getFrontendOpts(), List);
+  HeaderSearchOptsToArgs(getHeaderSearchOpts(), List);
+  LangOptsToArgs(*getLangOpts(), List);
+  PreprocessorOptsToArgs(getPreprocessorOpts(), List);
+  PreprocessorOutputOptsToArgs(getPreprocessorOutputOpts(), List);
+  TargetOptsToArgs(getTargetOpts(), List);
+}
+
+//===----------------------------------------------------------------------===//
+// Deserialization (to args)
+//===----------------------------------------------------------------------===//
+
+using namespace clang::driver;
+using namespace clang::driver::cc1options;
+
+//
+
+static unsigned getOptimizationLevel(ArgList &Args, InputKind IK,
+                                     DiagnosticsEngine &Diags) {
+  unsigned DefaultOpt = 0;
+  if (IK == IK_OpenCL && !Args.hasArg(OPT_cl_opt_disable))
+    DefaultOpt = 2;
+  // -Os/-Oz implies -O2
+  return (Args.hasArg(OPT_Os) || Args.hasArg (OPT_Oz)) ? 2 :
+    Args.getLastArgIntValue(OPT_O, DefaultOpt, Diags);
+}
+
+static bool ParseAnalyzerArgs(AnalyzerOptions &Opts, ArgList &Args,
+                              DiagnosticsEngine &Diags) {
+  using namespace cc1options;
+  bool Success = true;
+  if (Arg *A = Args.getLastArg(OPT_analyzer_store)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisStores Value = llvm::StringSwitch<AnalysisStores>(Name)
+#define ANALYSIS_STORE(NAME, CMDFLAG, DESC, CREATFN) \
+      .Case(CMDFLAG, NAME##Model)
+#include "clang/Frontend/Analyses.def"
+      .Default(NumStores);
+    if (Value == NumStores) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.AnalysisStoreOpt = Value;
+    }
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_analyzer_constraints)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisConstraints Value = llvm::StringSwitch<AnalysisConstraints>(Name)
+#define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATFN) \
+      .Case(CMDFLAG, NAME##Model)
+#include "clang/Frontend/Analyses.def"
+      .Default(NumConstraints);
+    if (Value == NumConstraints) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.AnalysisConstraintsOpt = Value;
+    }
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_analyzer_output)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisDiagClients Value = llvm::StringSwitch<AnalysisDiagClients>(Name)
+#define ANALYSIS_DIAGNOSTICS(NAME, CMDFLAG, DESC, CREATFN, AUTOCREAT) \
+      .Case(CMDFLAG, PD_##NAME)
+#include "clang/Frontend/Analyses.def"
+      .Default(NUM_ANALYSIS_DIAG_CLIENTS);
+    if (Value == NUM_ANALYSIS_DIAG_CLIENTS) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.AnalysisDiagOpt = Value;
+    }
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_analyzer_purge)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisPurgeMode Value = llvm::StringSwitch<AnalysisPurgeMode>(Name)
+#define ANALYSIS_PURGE(NAME, CMDFLAG, DESC) \
+      .Case(CMDFLAG, NAME)
+#include "clang/Frontend/Analyses.def"
+      .Default(NumPurgeModes);
+    if (Value == NumPurgeModes) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.AnalysisPurgeOpt = Value;
+    }
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_analyzer_ipa)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisIPAMode Value = llvm::StringSwitch<AnalysisIPAMode>(Name)
+#define ANALYSIS_IPA(NAME, CMDFLAG, DESC) \
+      .Case(CMDFLAG, NAME)
+#include "clang/Frontend/Analyses.def"
+      .Default(NumIPAModes);
+    if (Value == NumIPAModes) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.IPAMode = Value;
+    }
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_analyzer_inlining_mode)) {
+    StringRef Name = A->getValue(Args);
+    AnalysisInliningMode Value = llvm::StringSwitch<AnalysisInliningMode>(Name)
+#define ANALYSIS_INLINING_MODE(NAME, CMDFLAG, DESC) \
+      .Case(CMDFLAG, NAME)
+#include "clang/Frontend/Analyses.def"
+      .Default(NumInliningModes);
+    if (Value == NumInliningModes) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.InliningMode = Value;
+    }
+  }
+
+  Opts.ShowCheckerHelp = Args.hasArg(OPT_analyzer_checker_help);
+  Opts.VisualizeEGDot = Args.hasArg(OPT_analyzer_viz_egraph_graphviz);
+  Opts.VisualizeEGUbi = Args.hasArg(OPT_analyzer_viz_egraph_ubigraph);
+  Opts.NoRetryExhausted = Args.hasArg(OPT_analyzer_disable_retry_exhausted);
+  Opts.AnalyzeAll = Args.hasArg(OPT_analyzer_opt_analyze_headers);
+  Opts.AnalyzerDisplayProgress = Args.hasArg(OPT_analyzer_display_progress);
+  Opts.AnalyzeNestedBlocks =
+    Args.hasArg(OPT_analyzer_opt_analyze_nested_blocks);
+  Opts.EagerlyAssume = Args.hasArg(OPT_analyzer_eagerly_assume);
+  Opts.AnalyzeSpecificFunction = Args.getLastArgValue(OPT_analyze_function);
+  Opts.UnoptimizedCFG = Args.hasArg(OPT_analysis_UnoptimizedCFG);
+  Opts.CFGAddImplicitDtors = Args.hasArg(OPT_analysis_CFGAddImplicitDtors);
+  Opts.CFGAddInitializers = Args.hasArg(OPT_analysis_CFGAddInitializers);
+  Opts.TrimGraph = Args.hasArg(OPT_trim_egraph);
+  Opts.MaxNodes = Args.getLastArgIntValue(OPT_analyzer_max_nodes, 150000,Diags);
+  Opts.MaxLoop = Args.getLastArgIntValue(OPT_analyzer_max_loop, 4, Diags);
+  Opts.EagerlyTrimEGraph = !Args.hasArg(OPT_analyzer_no_eagerly_trim_egraph);
+  Opts.PrintStats = Args.hasArg(OPT_analyzer_stats);
+  Opts.InlineMaxStackDepth =
+    Args.getLastArgIntValue(OPT_analyzer_inline_max_stack_depth,
+                            Opts.InlineMaxStackDepth, Diags);
+  Opts.InlineMaxFunctionSize =
+    Args.getLastArgIntValue(OPT_analyzer_inline_max_function_size,
+                            Opts.InlineMaxFunctionSize, Diags);
+
+  Opts.CheckersControlList.clear();
+  for (arg_iterator it = Args.filtered_begin(OPT_analyzer_checker,
+                                             OPT_analyzer_disable_checker),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    A->claim();
+    bool enable = (A->getOption().getID() == OPT_analyzer_checker);
+    // We can have a list of comma separated checker names, e.g:
+    // '-analyzer-checker=cocoa,unix'
+    StringRef checkerList = A->getValue(Args);
+    SmallVector<StringRef, 4> checkers;
+    checkerList.split(checkers, ",");
+    for (unsigned i = 0, e = checkers.size(); i != e; ++i)
+      Opts.CheckersControlList.push_back(std::make_pair(checkers[i], enable));
+  }
+
+  return Success;
+}
+
+static bool ParseMigratorArgs(MigratorOptions &Opts, ArgList &Args) {
+  Opts.NoNSAllocReallocError = Args.hasArg(OPT_migrator_no_nsalloc_error);
+  Opts.NoFinalizeRemoval = Args.hasArg(OPT_migrator_no_finalize_removal);
+  return true;
+}
+
+static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
+                             DiagnosticsEngine &Diags) {
+  using namespace cc1options;
+  bool Success = true;
+
+  unsigned OptLevel = getOptimizationLevel(Args, IK, Diags);
+  if (OptLevel > 3) {
+    Diags.Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_O)->getAsString(Args) << OptLevel;
+    OptLevel = 3;
+    Success = false;
+  }
+  Opts.OptimizationLevel = OptLevel;
+
+  // We must always run at least the always inlining pass.
+  Opts.Inlining = (Opts.OptimizationLevel > 1) ? CodeGenOptions::NormalInlining
+    : CodeGenOptions::OnlyAlwaysInlining;
+  // -fno-inline-functions overrides OptimizationLevel > 1.
+  Opts.NoInline = Args.hasArg(OPT_fno_inline);
+  Opts.Inlining = Args.hasArg(OPT_fno_inline_functions) ? 
+    CodeGenOptions::OnlyAlwaysInlining : Opts.Inlining;
+
+  Opts.DebugInfo = Args.hasArg(OPT_g);
+  Opts.LimitDebugInfo = !Args.hasArg(OPT_fno_limit_debug_info)
+    || Args.hasArg(OPT_flimit_debug_info);
+  Opts.DisableLLVMOpts = Args.hasArg(OPT_disable_llvm_optzns);
+  Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone);
+  Opts.ForbidGuardVariables = Args.hasArg(OPT_fforbid_guard_variables);
+  Opts.UseRegisterSizedBitfieldAccess = Args.hasArg(
+    OPT_fuse_register_sized_bitfield_access);
+  Opts.RelaxedAliasing = Args.hasArg(OPT_relaxed_aliasing);
+  Opts.DwarfDebugFlags = Args.getLastArgValue(OPT_dwarf_debug_flags);
+  Opts.MergeAllConstants = !Args.hasArg(OPT_fno_merge_all_constants);
+  Opts.NoCommon = Args.hasArg(OPT_fno_common);
+  Opts.NoImplicitFloat = Args.hasArg(OPT_no_implicit_float);
+  Opts.OptimizeSize = Args.hasArg(OPT_Os);
+  Opts.OptimizeSize = Args.hasArg(OPT_Oz) ? 2 : Opts.OptimizeSize;
+  Opts.SimplifyLibCalls = !(Args.hasArg(OPT_fno_builtin) ||
+                            Args.hasArg(OPT_ffreestanding));
+  Opts.UnrollLoops = Args.hasArg(OPT_funroll_loops) ||
+                     (Opts.OptimizationLevel > 1 && !Opts.OptimizeSize);
+
+  Opts.AsmVerbose = Args.hasArg(OPT_masm_verbose);
+  Opts.ObjCAutoRefCountExceptions = Args.hasArg(OPT_fobjc_arc_exceptions);
+  Opts.ObjCRuntimeHasARC = Args.hasArg(OPT_fobjc_runtime_has_arc);
+  Opts.ObjCRuntimeHasTerminate = Args.hasArg(OPT_fobjc_runtime_has_terminate);
+  Opts.CUDAIsDevice = Args.hasArg(OPT_fcuda_is_device);
+  Opts.CXAAtExit = !Args.hasArg(OPT_fno_use_cxa_atexit);
+  Opts.CXXCtorDtorAliases = Args.hasArg(OPT_mconstructor_aliases);
+  Opts.CodeModel = Args.getLastArgValue(OPT_mcode_model);
+  Opts.DebugPass = Args.getLastArgValue(OPT_mdebug_pass);
+  Opts.DisableFPElim = Args.hasArg(OPT_mdisable_fp_elim);
+  Opts.DisableTailCalls = Args.hasArg(OPT_mdisable_tail_calls);
+  Opts.FloatABI = Args.getLastArgValue(OPT_mfloat_abi);
+  Opts.HiddenWeakVTables = Args.hasArg(OPT_fhidden_weak_vtables);
+  Opts.LessPreciseFPMAD = Args.hasArg(OPT_cl_mad_enable);
+  Opts.LimitFloatPrecision = Args.getLastArgValue(OPT_mlimit_float_precision);
+  Opts.NoInfsFPMath = (Args.hasArg(OPT_menable_no_infinities) ||
+                       Args.hasArg(OPT_cl_finite_math_only)||
+                       Args.hasArg(OPT_cl_fast_relaxed_math));
+  Opts.NoNaNsFPMath = (Args.hasArg(OPT_menable_no_nans) ||
+                       Args.hasArg(OPT_cl_finite_math_only)||
+                       Args.hasArg(OPT_cl_fast_relaxed_math));
+  Opts.NoZeroInitializedInBSS = Args.hasArg(OPT_mno_zero_initialized_in_bss);
+  Opts.BackendOptions = Args.getAllArgValues(OPT_backend_option);
+  Opts.NumRegisterParameters = Args.getLastArgIntValue(OPT_mregparm, 0, Diags);
+  Opts.NoGlobalMerge = Args.hasArg(OPT_mno_global_merge);
+  Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
+  Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
+  Opts.OmitLeafFramePointer = Args.hasArg(OPT_momit_leaf_frame_pointer);
+  Opts.SaveTempLabels = Args.hasArg(OPT_msave_temp_labels);
+  Opts.NoDwarf2CFIAsm = Args.hasArg(OPT_fno_dwarf2_cfi_asm);
+  Opts.NoDwarfDirectoryAsm = Args.hasArg(OPT_fno_dwarf_directory_asm);
+  Opts.SoftFloat = Args.hasArg(OPT_msoft_float);
+  Opts.StrictEnums = Args.hasArg(OPT_fstrict_enums);
+  Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
+                      Args.hasArg(OPT_cl_unsafe_math_optimizations) ||
+                      Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.UnwindTables = Args.hasArg(OPT_munwind_tables);
+  Opts.RelocationModel = Args.getLastArgValue(OPT_mrelocation_model, "pic");
+  Opts.TrapFuncName = Args.getLastArgValue(OPT_ftrap_function_EQ);
+
+  Opts.FunctionSections = Args.hasArg(OPT_ffunction_sections);
+  Opts.DataSections = Args.hasArg(OPT_fdata_sections);
+
+  Opts.MainFileName = Args.getLastArgValue(OPT_main_file_name);
+  Opts.VerifyModule = !Args.hasArg(OPT_disable_llvm_verifier);
+
+  Opts.InstrumentFunctions = Args.hasArg(OPT_finstrument_functions);
+  Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
+  Opts.EmitGcovArcs = Args.hasArg(OPT_femit_coverage_data);
+  Opts.EmitGcovNotes = Args.hasArg(OPT_femit_coverage_notes);
+  Opts.CoverageFile = Args.getLastArgValue(OPT_coverage_file);
+  Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
+  Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file);
+  Opts.StackRealignment = Args.hasArg(OPT_mstackrealign);
+  if (Arg *A = Args.getLastArg(OPT_mstack_alignment)) {
+    StringRef Val = A->getValue(Args);
+    Val.getAsInteger(10, Opts.StackAlignment);
+  }
+
+  if (Arg *A = Args.getLastArg(OPT_fobjc_dispatch_method_EQ)) {
+    StringRef Name = A->getValue(Args);
+    unsigned Method = llvm::StringSwitch<unsigned>(Name)
+      .Case("legacy", CodeGenOptions::Legacy)
+      .Case("non-legacy", CodeGenOptions::NonLegacy)
+      .Case("mixed", CodeGenOptions::Mixed)
+      .Default(~0U);
+    if (Method == ~0U) {
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
+      Success = false;
+    } else {
+      Opts.ObjCDispatchMethod = Method;
+    }
+  }
+
+  return Success;
+}
+
+static void ParseDependencyOutputArgs(DependencyOutputOptions &Opts,
+                                      ArgList &Args) {
+  using namespace cc1options;
+  Opts.OutputFile = Args.getLastArgValue(OPT_dependency_file);
+  Opts.Targets = Args.getAllArgValues(OPT_MT);
+  Opts.IncludeSystemHeaders = Args.hasArg(OPT_sys_header_deps);
+  Opts.UsePhonyTargets = Args.hasArg(OPT_MP);
+  Opts.ShowHeaderIncludes = Args.hasArg(OPT_H);
+  Opts.HeaderIncludeOutputFile = Args.getLastArgValue(OPT_header_include_file);
+  Opts.AddMissingHeaderDeps = Args.hasArg(OPT_MG);
+  Opts.DOTOutputFile = Args.getLastArgValue(OPT_dependency_dot);
+}
+
+bool clang::ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
+                                DiagnosticsEngine *Diags) {
+  using namespace cc1options;
+  bool Success = true;
+
+  Opts.DiagnosticLogFile = Args.getLastArgValue(OPT_diagnostic_log_file);
+  Opts.DiagnosticSerializationFile =
+    Args.getLastArgValue(OPT_diagnostic_serialized_file);
+  Opts.IgnoreWarnings = Args.hasArg(OPT_w);
+  Opts.NoRewriteMacros = Args.hasArg(OPT_Wno_rewrite_macros);
+  Opts.Pedantic = Args.hasArg(OPT_pedantic);
+  Opts.PedanticErrors = Args.hasArg(OPT_pedantic_errors);
+  Opts.ShowCarets = !Args.hasArg(OPT_fno_caret_diagnostics);
+  Opts.ShowColors = Args.hasArg(OPT_fcolor_diagnostics);
+  Opts.ShowColumn = Args.hasFlag(OPT_fshow_column,
+                                 OPT_fno_show_column,
+                                 /*Default=*/true);
+  Opts.ShowFixits = !Args.hasArg(OPT_fno_diagnostics_fixit_info);
+  Opts.ShowLocation = !Args.hasArg(OPT_fno_show_source_location);
+  Opts.ShowOptionNames = Args.hasArg(OPT_fdiagnostics_show_option);
+
+  // Default behavior is to not to show note include stacks.
+  Opts.ShowNoteIncludeStack = false;
+  if (Arg *A = Args.getLastArg(OPT_fdiagnostics_show_note_include_stack,
+                               OPT_fno_diagnostics_show_note_include_stack))
+    if (A->getOption().matches(OPT_fdiagnostics_show_note_include_stack))
+      Opts.ShowNoteIncludeStack = true;
+
+  StringRef ShowOverloads =
+    Args.getLastArgValue(OPT_fshow_overloads_EQ, "all");
+  if (ShowOverloads == "best")
+    Opts.ShowOverloads = DiagnosticsEngine::Ovl_Best;
+  else if (ShowOverloads == "all")
+    Opts.ShowOverloads = DiagnosticsEngine::Ovl_All;
+  else {
+    Success = false;
+    if (Diags)
+      Diags->Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_fshow_overloads_EQ)->getAsString(Args)
+      << ShowOverloads;
+  }
+
+  StringRef ShowCategory =
+    Args.getLastArgValue(OPT_fdiagnostics_show_category, "none");
+  if (ShowCategory == "none")
+    Opts.ShowCategories = 0;
+  else if (ShowCategory == "id")
+    Opts.ShowCategories = 1;
+  else if (ShowCategory == "name")
+    Opts.ShowCategories = 2;
+  else {
+    Success = false;
+    if (Diags)
+      Diags->Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_fdiagnostics_show_category)->getAsString(Args)
+      << ShowCategory;
+  }
+
+  StringRef Format =
+    Args.getLastArgValue(OPT_fdiagnostics_format, "clang");
+  if (Format == "clang")
+    Opts.Format = DiagnosticOptions::Clang;
+  else if (Format == "msvc")
+    Opts.Format = DiagnosticOptions::Msvc;
+  else if (Format == "vi")
+    Opts.Format = DiagnosticOptions::Vi;
+  else {
+    Success = false;
+    if (Diags)
+      Diags->Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_fdiagnostics_format)->getAsString(Args)
+      << Format;
+  }
+  
+  Opts.ShowSourceRanges = Args.hasArg(OPT_fdiagnostics_print_source_range_info);
+  Opts.ShowParseableFixits = Args.hasArg(OPT_fdiagnostics_parseable_fixits);
+  Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
+  Opts.ErrorLimit = Args.getLastArgIntValue(OPT_ferror_limit, 0, Diags);
+  Opts.MacroBacktraceLimit
+    = Args.getLastArgIntValue(OPT_fmacro_backtrace_limit,
+                         DiagnosticOptions::DefaultMacroBacktraceLimit, Diags);
+  Opts.TemplateBacktraceLimit
+    = Args.getLastArgIntValue(OPT_ftemplate_backtrace_limit,
+                         DiagnosticOptions::DefaultTemplateBacktraceLimit,
+                         Diags);
+  Opts.ConstexprBacktraceLimit
+    = Args.getLastArgIntValue(OPT_fconstexpr_backtrace_limit,
+                         DiagnosticOptions::DefaultConstexprBacktraceLimit,
+                         Diags);
+  Opts.TabStop = Args.getLastArgIntValue(OPT_ftabstop,
+                                    DiagnosticOptions::DefaultTabStop, Diags);
+  if (Opts.TabStop == 0 || Opts.TabStop > DiagnosticOptions::MaxTabStop) {
+    Opts.TabStop = DiagnosticOptions::DefaultTabStop;
+    if (Diags)
+      Diags->Report(diag::warn_ignoring_ftabstop_value)
+      << Opts.TabStop << DiagnosticOptions::DefaultTabStop;
+  }
+  Opts.MessageLength = Args.getLastArgIntValue(OPT_fmessage_length, 0, Diags);
+  Opts.DumpBuildInformation = Args.getLastArgValue(OPT_dump_build_information);
+
+  for (arg_iterator it = Args.filtered_begin(OPT_W),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    StringRef V = (*it)->getValue(Args);
+    // "-Wl," and such are not warnings options.
+    if (V.startswith("l,") || V.startswith("a,") || V.startswith("p,"))
+      continue;
+
+    Opts.Warnings.push_back(V);
+  }
+
+  return Success;
+}
+
+static void ParseFileSystemArgs(FileSystemOptions &Opts, ArgList &Args) {
+  Opts.WorkingDir = Args.getLastArgValue(OPT_working_directory);
+}
+
+static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
+                                   DiagnosticsEngine &Diags) {
+  using namespace cc1options;
+  Opts.ProgramAction = frontend::ParseSyntaxOnly;
+  if (const Arg *A = Args.getLastArg(OPT_Action_Group)) {
+    switch (A->getOption().getID()) {
+    default:
+      llvm_unreachable("Invalid option in group!");
+    case OPT_ast_dump:
+      Opts.ProgramAction = frontend::ASTDump; break;
+    case OPT_ast_dump_xml:
+      Opts.ProgramAction = frontend::ASTDumpXML; break;
+    case OPT_ast_print:
+      Opts.ProgramAction = frontend::ASTPrint; break;
+    case OPT_ast_view:
+      Opts.ProgramAction = frontend::ASTView; break;
+    case OPT_dump_raw_tokens:
+      Opts.ProgramAction = frontend::DumpRawTokens; break;
+    case OPT_dump_tokens:
+      Opts.ProgramAction = frontend::DumpTokens; break;
+    case OPT_S:
+      Opts.ProgramAction = frontend::EmitAssembly; break;
+    case OPT_emit_llvm_bc:
+      Opts.ProgramAction = frontend::EmitBC; break;
+    case OPT_emit_html:
+      Opts.ProgramAction = frontend::EmitHTML; break;
+    case OPT_emit_llvm:
+      Opts.ProgramAction = frontend::EmitLLVM; break;
+    case OPT_emit_llvm_only:
+      Opts.ProgramAction = frontend::EmitLLVMOnly; break;
+    case OPT_emit_codegen_only:
+      Opts.ProgramAction = frontend::EmitCodeGenOnly; break;
+    case OPT_emit_obj:
+      Opts.ProgramAction = frontend::EmitObj; break;
+    case OPT_fixit_EQ:
+      Opts.FixItSuffix = A->getValue(Args);
+      // fall-through!
+    case OPT_fixit:
+      Opts.ProgramAction = frontend::FixIt; break;
+    case OPT_emit_module:
+      Opts.ProgramAction = frontend::GenerateModule; break;
+    case OPT_emit_pch:
+      Opts.ProgramAction = frontend::GeneratePCH; break;
+    case OPT_emit_pth:
+      Opts.ProgramAction = frontend::GeneratePTH; break;
+    case OPT_init_only:
+      Opts.ProgramAction = frontend::InitOnly; break;
+    case OPT_fsyntax_only:
+      Opts.ProgramAction = frontend::ParseSyntaxOnly; break;
+    case OPT_print_decl_contexts:
+      Opts.ProgramAction = frontend::PrintDeclContext; break;
+    case OPT_print_preamble:
+      Opts.ProgramAction = frontend::PrintPreamble; break;
+    case OPT_E:
+      Opts.ProgramAction = frontend::PrintPreprocessedInput; break;
+    case OPT_rewrite_macros:
+      Opts.ProgramAction = frontend::RewriteMacros; break;
+    case OPT_rewrite_objc:
+      Opts.ProgramAction = frontend::RewriteObjC; break;
+    case OPT_rewrite_test:
+      Opts.ProgramAction = frontend::RewriteTest; break;
+    case OPT_analyze:
+      Opts.ProgramAction = frontend::RunAnalysis; break;
+    case OPT_migrate:
+      Opts.ProgramAction = frontend::MigrateSource; break;
+    case OPT_Eonly:
+      Opts.ProgramAction = frontend::RunPreprocessorOnly; break;
+    }
+  }
+
+  if (const Arg* A = Args.getLastArg(OPT_plugin)) {
+    Opts.Plugins.push_back(A->getValue(Args,0));
+    Opts.ProgramAction = frontend::PluginAction;
+    Opts.ActionName = A->getValue(Args);
+
+    for (arg_iterator it = Args.filtered_begin(OPT_plugin_arg),
+           end = Args.filtered_end(); it != end; ++it) {
+      if ((*it)->getValue(Args, 0) == Opts.ActionName)
+        Opts.PluginArgs.push_back((*it)->getValue(Args, 1));
+    }
+  }
+
+  Opts.AddPluginActions = Args.getAllArgValues(OPT_add_plugin);
+  Opts.AddPluginArgs.resize(Opts.AddPluginActions.size());
+  for (int i = 0, e = Opts.AddPluginActions.size(); i != e; ++i) {
+    for (arg_iterator it = Args.filtered_begin(OPT_plugin_arg),
+           end = Args.filtered_end(); it != end; ++it) {
+      if ((*it)->getValue(Args, 0) == Opts.AddPluginActions[i])
+        Opts.AddPluginArgs[i].push_back((*it)->getValue(Args, 1));
+    }
+  }
+
+  if (const Arg *A = Args.getLastArg(OPT_code_completion_at)) {
+    Opts.CodeCompletionAt =
+      ParsedSourceLocation::FromString(A->getValue(Args));
+    if (Opts.CodeCompletionAt.FileName.empty())
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << A->getValue(Args);
+  }
+  Opts.DisableFree = Args.hasArg(OPT_disable_free);
+
+  Opts.OutputFile = Args.getLastArgValue(OPT_o);
+  Opts.Plugins = Args.getAllArgValues(OPT_load);
+  Opts.RelocatablePCH = Args.hasArg(OPT_relocatable_pch);
+  Opts.ShowHelp = Args.hasArg(OPT_help);
+  Opts.ShowMacrosInCodeCompletion = Args.hasArg(OPT_code_completion_macros);
+  Opts.ShowCodePatternsInCodeCompletion
+    = Args.hasArg(OPT_code_completion_patterns);
+  Opts.ShowGlobalSymbolsInCodeCompletion
+    = !Args.hasArg(OPT_no_code_completion_globals);
+  Opts.ShowStats = Args.hasArg(OPT_print_stats);
+  Opts.ShowTimers = Args.hasArg(OPT_ftime_report);
+  Opts.ShowVersion = Args.hasArg(OPT_version);
+  Opts.ASTMergeFiles = Args.getAllArgValues(OPT_ast_merge);
+  Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
+  Opts.FixWhatYouCan = Args.hasArg(OPT_fix_what_you_can);
+  Opts.FixOnlyWarnings = Args.hasArg(OPT_fix_only_warnings);
+  Opts.FixAndRecompile = Args.hasArg(OPT_fixit_recompile);
+  Opts.FixToTemporaries = Args.hasArg(OPT_fixit_to_temp);
+  Opts.OverrideRecordLayoutsFile
+    = Args.getLastArgValue(OPT_foverride_record_layout_EQ);
+  if (const Arg *A = Args.getLastArg(OPT_arcmt_check,
+                                     OPT_arcmt_modify,
+                                     OPT_arcmt_migrate)) {
+    switch (A->getOption().getID()) {
+    default:
+      llvm_unreachable("missed a case");
+    case OPT_arcmt_check:
+      Opts.ARCMTAction = FrontendOptions::ARCMT_Check;
+      break;
+    case OPT_arcmt_modify:
+      Opts.ARCMTAction = FrontendOptions::ARCMT_Modify;
+      break;
+    case OPT_arcmt_migrate:
+      Opts.ARCMTAction = FrontendOptions::ARCMT_Migrate;
+      break;
+    }
+  }
+  Opts.MTMigrateDir = Args.getLastArgValue(OPT_mt_migrate_directory);
+  Opts.ARCMTMigrateReportOut
+    = Args.getLastArgValue(OPT_arcmt_migrate_report_output);
+  Opts.ARCMTMigrateEmitARCErrors
+    = Args.hasArg(OPT_arcmt_migrate_emit_arc_errors);
+
+  if (Args.hasArg(OPT_objcmt_migrate_literals))
+    Opts.ObjCMTAction |= FrontendOptions::ObjCMT_Literals;
+  if (Args.hasArg(OPT_objcmt_migrate_subscripting))
+    Opts.ObjCMTAction |= FrontendOptions::ObjCMT_Subscripting;
+
+  if (Opts.ARCMTAction != FrontendOptions::ARCMT_None &&
+      Opts.ObjCMTAction != FrontendOptions::ObjCMT_None) {
+    Diags.Report(diag::err_drv_argument_not_allowed_with)
+      << "ARC migration" << "ObjC migration";
+  }
+
+  InputKind DashX = IK_None;
+  if (const Arg *A = Args.getLastArg(OPT_x)) {
+    DashX = llvm::StringSwitch<InputKind>(A->getValue(Args))
+      .Case("c", IK_C)
+      .Case("cl", IK_OpenCL)
+      .Case("cuda", IK_CUDA)
+      .Case("c++", IK_CXX)
+      .Case("objective-c", IK_ObjC)
+      .Case("objective-c++", IK_ObjCXX)
+      .Case("cpp-output", IK_PreprocessedC)
+      .Case("assembler-with-cpp", IK_Asm)
+      .Case("c++-cpp-output", IK_PreprocessedCXX)
+      .Case("objective-c-cpp-output", IK_PreprocessedObjC)
+      .Case("objc-cpp-output", IK_PreprocessedObjC)
+      .Case("objective-c++-cpp-output", IK_PreprocessedObjCXX)
+      .Case("objc++-cpp-output", IK_PreprocessedObjCXX)
+      .Case("c-header", IK_C)
+      .Case("cl-header", IK_OpenCL)
+      .Case("objective-c-header", IK_ObjC)
+      .Case("c++-header", IK_CXX)
+      .Case("objective-c++-header", IK_ObjCXX)
+      .Case("ast", IK_AST)
+      .Case("ir", IK_LLVM_IR)
+      .Default(IK_None);
+    if (DashX == IK_None)
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << A->getValue(Args);
+  }
+
+  // '-' is the default input if none is given.
+  std::vector<std::string> Inputs = Args.getAllArgValues(OPT_INPUT);
+  Opts.Inputs.clear();
+  if (Inputs.empty())
+    Inputs.push_back("-");
+  for (unsigned i = 0, e = Inputs.size(); i != e; ++i) {
+    InputKind IK = DashX;
+    if (IK == IK_None) {
+      IK = FrontendOptions::getInputKindForExtension(
+        StringRef(Inputs[i]).rsplit('.').second);
+      // FIXME: Remove this hack.
+      if (i == 0)
+        DashX = IK;
+    }
+    Opts.Inputs.push_back(FrontendInputFile(Inputs[i], IK));
+  }
+
+  return DashX;
+}
+
+std::string CompilerInvocation::GetResourcesPath(const char *Argv0,
+                                                 void *MainAddr) {
+  llvm::sys::Path P = llvm::sys::Path::GetMainExecutable(Argv0, MainAddr);
+
+  if (!P.isEmpty()) {
+    P.eraseComponent();  // Remove /clang from foo/bin/clang
+    P.eraseComponent();  // Remove /bin   from foo/bin
+
+    // Get foo/lib/clang/<version>/include
+    P.appendComponent("lib");
+    P.appendComponent("clang");
+    P.appendComponent(CLANG_VERSION_STRING);
+  }
+
+  return P.str();
+}
+
+static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
+  using namespace cc1options;
+  Opts.Sysroot = Args.getLastArgValue(OPT_isysroot, "/");
+  Opts.Verbose = Args.hasArg(OPT_v);
+  Opts.UseBuiltinIncludes = !Args.hasArg(OPT_nobuiltininc);
+  Opts.UseStandardSystemIncludes = !Args.hasArg(OPT_nostdsysteminc);
+  Opts.UseStandardCXXIncludes = !Args.hasArg(OPT_nostdincxx);
+  if (const Arg *A = Args.getLastArg(OPT_stdlib_EQ))
+    Opts.UseLibcxx = (strcmp(A->getValue(Args), "libc++") == 0);
+  Opts.ResourceDir = Args.getLastArgValue(OPT_resource_dir);
+  Opts.ModuleCachePath = Args.getLastArgValue(OPT_fmodule_cache_path);
+  Opts.DisableModuleHash = Args.hasArg(OPT_fdisable_module_hash);
+  
+  // Add -I..., -F..., and -index-header-map options in order.
+  bool IsIndexHeaderMap = false;
+  for (arg_iterator it = Args.filtered_begin(OPT_I, OPT_F, 
+                                             OPT_index_header_map),
+       ie = Args.filtered_end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(OPT_index_header_map)) {
+      // -index-header-map applies to the next -I or -F.
+      IsIndexHeaderMap = true;
+      continue;
+    }
+        
+    frontend::IncludeDirGroup Group 
+      = IsIndexHeaderMap? frontend::IndexHeaderMap : frontend::Angled;
+    
+    Opts.AddPath((*it)->getValue(Args), Group, true,
+                 /*IsFramework=*/ (*it)->getOption().matches(OPT_F), false);
+    IsIndexHeaderMap = false;
+  }
+
+  // Add -iprefix/-iwith-prefix/-iwithprefixbefore options.
+  StringRef Prefix = ""; // FIXME: This isn't the correct default prefix.
+  for (arg_iterator it = Args.filtered_begin(OPT_iprefix, OPT_iwithprefix,
+                                             OPT_iwithprefixbefore),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    if (A->getOption().matches(OPT_iprefix))
+      Prefix = A->getValue(Args);
+    else if (A->getOption().matches(OPT_iwithprefix))
+      Opts.AddPath(Prefix.str() + A->getValue(Args),
+                   frontend::System, false, false, false);
+    else
+      Opts.AddPath(Prefix.str() + A->getValue(Args),
+                   frontend::Angled, false, false, false);
+  }
+
+  for (arg_iterator it = Args.filtered_begin(OPT_idirafter),
+         ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::After, true, false, false);
+  for (arg_iterator it = Args.filtered_begin(OPT_iquote),
+         ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::Quoted, true, false, false);
+  for (arg_iterator it = Args.filtered_begin(OPT_isystem,
+         OPT_iwithsysroot), ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::System, true, false,
+                 !(*it)->getOption().matches(OPT_iwithsysroot));
+  for (arg_iterator it = Args.filtered_begin(OPT_iframework),
+         ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::System, true, true,
+                 true);
+
+  // Add the paths for the various language specific isystem flags.
+  for (arg_iterator it = Args.filtered_begin(OPT_c_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::CSystem, true, false, true);
+  for (arg_iterator it = Args.filtered_begin(OPT_cxx_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::CXXSystem, true, false, true);
+  for (arg_iterator it = Args.filtered_begin(OPT_objc_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::ObjCSystem, true, false,true);
+  for (arg_iterator it = Args.filtered_begin(OPT_objcxx_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::ObjCXXSystem, true, false,
+                 true);
+
+  // Add the internal paths from a driver that detects standard include paths.
+  for (arg_iterator I = Args.filtered_begin(OPT_internal_isystem,
+                                            OPT_internal_externc_isystem),
+                    E = Args.filtered_end();
+       I != E; ++I)
+    Opts.AddPath((*I)->getValue(Args), frontend::System,
+                 false, false, /*IgnoreSysRoot=*/true, /*IsInternal=*/true,
+                 (*I)->getOption().matches(OPT_internal_externc_isystem));
+}
+
+void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
+                                         LangStandard::Kind LangStd) {
+  // Set some properties which depend solely on the input kind; it would be nice
+  // to move these to the language standard, and have the driver resolve the
+  // input kind + language standard.
+  if (IK == IK_Asm) {
+    Opts.AsmPreprocessor = 1;
+  } else if (IK == IK_ObjC ||
+             IK == IK_ObjCXX ||
+             IK == IK_PreprocessedObjC ||
+             IK == IK_PreprocessedObjCXX) {
+    Opts.ObjC1 = Opts.ObjC2 = 1;
+  }
+
+  if (LangStd == LangStandard::lang_unspecified) {
+    // Based on the base language, pick one.
+    switch (IK) {
+    case IK_None:
+    case IK_AST:
+    case IK_LLVM_IR:
+      llvm_unreachable("Invalid input kind!");
+    case IK_OpenCL:
+      LangStd = LangStandard::lang_opencl;
+      break;
+    case IK_CUDA:
+      LangStd = LangStandard::lang_cuda;
+      break;
+    case IK_Asm:
+    case IK_C:
+    case IK_PreprocessedC:
+    case IK_ObjC:
+    case IK_PreprocessedObjC:
+      LangStd = LangStandard::lang_gnu99;
+      break;
+    case IK_CXX:
+    case IK_PreprocessedCXX:
+    case IK_ObjCXX:
+    case IK_PreprocessedObjCXX:
+      LangStd = LangStandard::lang_gnucxx98;
+      break;
+    }
+  }
+
+  const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
+  Opts.BCPLComment = Std.hasBCPLComments();
+  Opts.C99 = Std.isC99();
+  Opts.C11 = Std.isC11();
+  Opts.CPlusPlus = Std.isCPlusPlus();
+  Opts.CPlusPlus0x = Std.isCPlusPlus0x();
+  Opts.Digraphs = Std.hasDigraphs();
+  Opts.GNUMode = Std.isGNUMode();
+  Opts.GNUInline = !Std.isC99();
+  Opts.HexFloats = Std.hasHexFloats();
+  Opts.ImplicitInt = Std.hasImplicitInt();
+
+  // OpenCL has some additional defaults.
+  if (LangStd == LangStandard::lang_opencl) {
+    Opts.OpenCL = 1;
+    Opts.AltiVec = 0;
+    Opts.CXXOperatorNames = 1;
+    Opts.LaxVectorConversions = 0;
+    Opts.DefaultFPContract = 1;
+  }
+
+  if (LangStd == LangStandard::lang_cuda)
+    Opts.CUDA = 1;
+
+  // OpenCL and C++ both have bool, true, false keywords.
+  Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;
+
+  Opts.GNUKeywords = Opts.GNUMode;
+  Opts.CXXOperatorNames = Opts.CPlusPlus;
+
+  // Mimicing gcc's behavior, trigraphs are only enabled if -trigraphs
+  // is specified, or -std is set to a conforming mode.
+  Opts.Trigraphs = !Opts.GNUMode;
+
+  Opts.DollarIdents = !Opts.AsmPreprocessor;
+}
+
+static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
+                          DiagnosticsEngine &Diags) {
+  // FIXME: Cleanup per-file based stuff.
+  LangStandard::Kind LangStd = LangStandard::lang_unspecified;
+  if (const Arg *A = Args.getLastArg(OPT_std_EQ)) {
+    LangStd = llvm::StringSwitch<LangStandard::Kind>(A->getValue(Args))
+#define LANGSTANDARD(id, name, desc, features) \
+      .Case(name, LangStandard::lang_##id)
+#include "clang/Frontend/LangStandards.def"
+      .Default(LangStandard::lang_unspecified);
+    if (LangStd == LangStandard::lang_unspecified)
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << A->getValue(Args);
+    else {
+      // Valid standard, check to make sure language and standard are compatable.    
+      const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
+      switch (IK) {
+      case IK_C:
+      case IK_ObjC:
+      case IK_PreprocessedC:
+      case IK_PreprocessedObjC:
+        if (!(Std.isC89() || Std.isC99()))
+          Diags.Report(diag::err_drv_argument_not_allowed_with)
+            << A->getAsString(Args) << "C/ObjC";
+        break;
+      case IK_CXX:
+      case IK_ObjCXX:
+      case IK_PreprocessedCXX:
+      case IK_PreprocessedObjCXX:
+        if (!Std.isCPlusPlus())
+          Diags.Report(diag::err_drv_argument_not_allowed_with)
+            << A->getAsString(Args) << "C++/ObjC++";
+        break;
+      case IK_OpenCL:
+        if (!Std.isC99())
+          Diags.Report(diag::err_drv_argument_not_allowed_with)
+            << A->getAsString(Args) << "OpenCL";
+        break;
+      case IK_CUDA:
+        if (!Std.isCPlusPlus())
+          Diags.Report(diag::err_drv_argument_not_allowed_with)
+            << A->getAsString(Args) << "CUDA";
+        break;
+      default:
+        break;
+      }
+    }
+  }
+
+  if (const Arg *A = Args.getLastArg(OPT_cl_std_EQ)) {
+    if (strcmp(A->getValue(Args), "CL1.1") != 0) {
+      Diags.Report(diag::err_drv_invalid_value)
+        << A->getAsString(Args) << A->getValue(Args);
+    }
+  }
+
+  CompilerInvocation::setLangDefaults(Opts, IK, LangStd);
+
+  // We abuse '-f[no-]gnu-keywords' to force overriding all GNU-extension
+  // keywords. This behavior is provided by GCC's poorly named '-fasm' flag,
+  // while a subset (the non-C++ GNU keywords) is provided by GCC's
+  // '-fgnu-keywords'. Clang conflates the two for simplicity under the single
+  // name, as it doesn't seem a useful distinction.
+  Opts.GNUKeywords = Args.hasFlag(OPT_fgnu_keywords, OPT_fno_gnu_keywords,
+                                  Opts.GNUKeywords);
+
+  if (Args.hasArg(OPT_fno_operator_names))
+    Opts.CXXOperatorNames = 0;
+
+  if (Opts.ObjC1) {
+    if (Args.hasArg(OPT_fobjc_gc_only))
+      Opts.setGC(LangOptions::GCOnly);
+    else if (Args.hasArg(OPT_fobjc_gc))
+      Opts.setGC(LangOptions::HybridGC);
+    else if (Args.hasArg(OPT_fobjc_arc)) {
+      Opts.ObjCAutoRefCount = 1;
+      if (Args.hasArg(OPT_fobjc_fragile_abi))
+        Diags.Report(diag::err_arc_nonfragile_abi);
+    }
+
+    if (Args.hasArg(OPT_fobjc_runtime_has_weak))
+      Opts.ObjCRuntimeHasWeak = 1;
+
+    if (Args.hasArg(OPT_fno_objc_infer_related_result_type))
+      Opts.ObjCInferRelatedResultType = 0;
+  }
+    
+  if (Args.hasArg(OPT_fgnu89_inline))
+    Opts.GNUInline = 1;
+
+  if (Args.hasArg(OPT_fapple_kext)) {
+    if (!Opts.CPlusPlus)
+      Diags.Report(diag::warn_c_kext);
+    else
+      Opts.AppleKext = 1;
+  }
+
+  if (Args.hasArg(OPT_print_ivar_layout))
+    Opts.ObjCGCBitmapPrint = 1;
+  if (Args.hasArg(OPT_fno_constant_cfstrings))
+    Opts.NoConstantCFStrings = 1;
+
+  if (Args.hasArg(OPT_faltivec))
+    Opts.AltiVec = 1;
+
+  if (Args.hasArg(OPT_pthread))
+    Opts.POSIXThreads = 1;
+
+  if (Args.hasArg(OPT_fdelayed_template_parsing))
+    Opts.DelayedTemplateParsing = 1;
+
+  StringRef Vis = Args.getLastArgValue(OPT_fvisibility, "default");
+  if (Vis == "default")
+    Opts.setVisibilityMode(DefaultVisibility);
+  else if (Vis == "hidden")
+    Opts.setVisibilityMode(HiddenVisibility);
+  else if (Vis == "protected")
+    // FIXME: diagnose if target does not support protected visibility
+    Opts.setVisibilityMode(ProtectedVisibility);
+  else
+    Diags.Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_fvisibility)->getAsString(Args) << Vis;
+
+  if (Args.hasArg(OPT_fvisibility_inlines_hidden))
+    Opts.InlineVisibilityHidden = 1;
+
+  if (Args.hasArg(OPT_ftrapv)) {
+    Opts.setSignedOverflowBehavior(LangOptions::SOB_Trapping);
+    // Set the handler, if one is specified.
+    Opts.OverflowHandler =
+        Args.getLastArgValue(OPT_ftrapv_handler);
+  }
+  else if (Args.hasArg(OPT_fwrapv))
+    Opts.setSignedOverflowBehavior(LangOptions::SOB_Defined);
+
+  if (Args.hasArg(OPT_trigraphs))
+    Opts.Trigraphs = 1;
+
+  Opts.DollarIdents = Args.hasFlag(OPT_fdollars_in_identifiers,
+                                   OPT_fno_dollars_in_identifiers,
+                                   Opts.DollarIdents);
+  Opts.PascalStrings = Args.hasArg(OPT_fpascal_strings);
+  Opts.MicrosoftExt
+    = Args.hasArg(OPT_fms_extensions) || Args.hasArg(OPT_fms_compatibility);
+  Opts.MicrosoftMode = Args.hasArg(OPT_fms_compatibility);
+  Opts.MSCVersion = Args.getLastArgIntValue(OPT_fmsc_version, 0, Diags);
+  Opts.Borland = Args.hasArg(OPT_fborland_extensions);
+  Opts.WritableStrings = Args.hasArg(OPT_fwritable_strings);
+  Opts.ConstStrings = Args.hasFlag(OPT_fconst_strings, OPT_fno_const_strings,
+                                   Opts.ConstStrings);
+  if (Args.hasArg(OPT_fno_lax_vector_conversions))
+    Opts.LaxVectorConversions = 0;
+  if (Args.hasArg(OPT_fno_threadsafe_statics))
+    Opts.ThreadsafeStatics = 0;
+  Opts.Exceptions = Args.hasArg(OPT_fexceptions);
+  Opts.ObjCExceptions = Args.hasArg(OPT_fobjc_exceptions);
+  Opts.CXXExceptions = Args.hasArg(OPT_fcxx_exceptions);
+  Opts.SjLjExceptions = Args.hasArg(OPT_fsjlj_exceptions);
+  Opts.TraditionalCPP = Args.hasArg(OPT_traditional_cpp);
+
+  Opts.RTTI = !Args.hasArg(OPT_fno_rtti);
+  Opts.Blocks = Args.hasArg(OPT_fblocks);
+  Opts.BlocksRuntimeOptional = Args.hasArg(OPT_fblocks_runtime_optional);
+  Opts.Modules = Args.hasArg(OPT_fmodules);
+  Opts.CharIsSigned = !Args.hasArg(OPT_fno_signed_char);
+  Opts.ShortWChar = Args.hasArg(OPT_fshort_wchar);
+  Opts.ShortEnums = Args.hasArg(OPT_fshort_enums);
+  Opts.Freestanding = Args.hasArg(OPT_ffreestanding);
+  Opts.NoBuiltin = Args.hasArg(OPT_fno_builtin) || Opts.Freestanding;
+  Opts.AssumeSaneOperatorNew = !Args.hasArg(OPT_fno_assume_sane_operator_new);
+  Opts.HeinousExtensions = Args.hasArg(OPT_fheinous_gnu_extensions);
+  Opts.AccessControl = !Args.hasArg(OPT_fno_access_control);
+  Opts.ElideConstructors = !Args.hasArg(OPT_fno_elide_constructors);
+  Opts.MathErrno = Args.hasArg(OPT_fmath_errno);
+  Opts.InstantiationDepth = Args.getLastArgIntValue(OPT_ftemplate_depth, 1024,
+                                                    Diags);
+  Opts.ConstexprCallDepth = Args.getLastArgIntValue(OPT_fconstexpr_depth, 512,
+                                                    Diags);
+  Opts.DelayedTemplateParsing = Args.hasArg(OPT_fdelayed_template_parsing);
+  Opts.NumLargeByValueCopy = Args.getLastArgIntValue(OPT_Wlarge_by_value_copy,
+                                                    0, Diags);
+  Opts.MSBitfields = Args.hasArg(OPT_mms_bitfields);
+  Opts.NeXTRuntime = !Args.hasArg(OPT_fgnu_runtime);
+  Opts.ObjCConstantStringClass =
+    Args.getLastArgValue(OPT_fconstant_string_class);
+  Opts.ObjCNonFragileABI = !Args.hasArg(OPT_fobjc_fragile_abi);
+  if (Opts.ObjCNonFragileABI)
+    Opts.ObjCNonFragileABI2 = true;
+  Opts.ObjCDefaultSynthProperties =
+    Args.hasArg(OPT_fobjc_default_synthesize_properties);
+  Opts.CatchUndefined = Args.hasArg(OPT_fcatch_undefined_behavior);
+  Opts.EmitAllDecls = Args.hasArg(OPT_femit_all_decls);
+  Opts.PackStruct = Args.getLastArgIntValue(OPT_fpack_struct, 0, Diags);
+  Opts.PICLevel = Args.getLastArgIntValue(OPT_pic_level, 0, Diags);
+  Opts.PIELevel = Args.getLastArgIntValue(OPT_pie_level, 0, Diags);
+  Opts.Static = Args.hasArg(OPT_static_define);
+  Opts.DumpRecordLayoutsSimple = Args.hasArg(OPT_fdump_record_layouts_simple);
+  Opts.DumpRecordLayouts = Opts.DumpRecordLayoutsSimple 
+                        || Args.hasArg(OPT_fdump_record_layouts);
+  Opts.DumpVTableLayouts = Args.hasArg(OPT_fdump_vtable_layouts);
+  Opts.SpellChecking = !Args.hasArg(OPT_fno_spell_checking);
+  Opts.NoBitFieldTypeAlign = Args.hasArg(OPT_fno_bitfield_type_align);
+  Opts.SinglePrecisionConstants = Args.hasArg(OPT_cl_single_precision_constant);
+  Opts.FastRelaxedMath = Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.MRTD = Args.hasArg(OPT_mrtd);
+  Opts.HexagonQdsp6Compat = Args.hasArg(OPT_mqdsp6_compat);
+  Opts.FakeAddressSpaceMap = Args.hasArg(OPT_ffake_address_space_map);
+  Opts.ParseUnknownAnytype = Args.hasArg(OPT_funknown_anytype);
+  Opts.DebuggerSupport = Args.hasArg(OPT_fdebugger_support);
+  Opts.DebuggerCastResultToId = Args.hasArg(OPT_fdebugger_cast_result_to_id);
+  Opts.DebuggerObjCLiteral = Args.hasArg(OPT_fdebugger_objc_literal);
+  Opts.AddressSanitizer = Args.hasArg(OPT_faddress_sanitizer);
+  Opts.ThreadSanitizer = Args.hasArg(OPT_fthread_sanitizer);
+  Opts.ApplePragmaPack = Args.hasArg(OPT_fapple_pragma_pack);
+  Opts.CurrentModule = Args.getLastArgValue(OPT_fmodule_name);
+
+  // Record whether the __DEPRECATED define was requested.
+  Opts.Deprecated = Args.hasFlag(OPT_fdeprecated_macro,
+                                 OPT_fno_deprecated_macro,
+                                 Opts.Deprecated);
+
+  // FIXME: Eliminate this dependency.
+  unsigned Opt = getOptimizationLevel(Args, IK, Diags);
+  Opts.Optimize = Opt != 0;
+  Opts.OptimizeSize = Args.hasArg(OPT_Os) || Args.hasArg(OPT_Oz);
+
+  // This is the __NO_INLINE__ define, which just depends on things like the
+  // optimization level and -fno-inline, not actually whether the backend has
+  // inlining enabled.
+  Opts.NoInlineDefine = !Opt || Args.hasArg(OPT_fno_inline);
+
+  Opts.FastMath = Args.hasArg(OPT_ffast_math);
+
+  unsigned SSP = Args.getLastArgIntValue(OPT_stack_protector, 0, Diags);
+  switch (SSP) {
+  default:
+    Diags.Report(diag::err_drv_invalid_value)
+      << Args.getLastArg(OPT_stack_protector)->getAsString(Args) << SSP;
+    break;
+  case 0: Opts.setStackProtector(LangOptions::SSPOff); break;
+  case 1: Opts.setStackProtector(LangOptions::SSPOn);  break;
+  case 2: Opts.setStackProtector(LangOptions::SSPReq); break;
+  }
+}
+
+static void ParsePreprocessorArgs(PreprocessorOptions &Opts, ArgList &Args,
+                                  FileManager &FileMgr,
+                                  DiagnosticsEngine &Diags) {
+  using namespace cc1options;
+  Opts.ImplicitPCHInclude = Args.getLastArgValue(OPT_include_pch);
+  Opts.ImplicitPTHInclude = Args.getLastArgValue(OPT_include_pth);
+  if (const Arg *A = Args.getLastArg(OPT_token_cache))
+      Opts.TokenCache = A->getValue(Args);
+  else
+    Opts.TokenCache = Opts.ImplicitPTHInclude;
+  Opts.UsePredefines = !Args.hasArg(OPT_undef);
+  Opts.DetailedRecord = Args.hasArg(OPT_detailed_preprocessing_record);
+  Opts.DisablePCHValidation = Args.hasArg(OPT_fno_validate_pch);
+
+  Opts.DumpDeserializedPCHDecls = Args.hasArg(OPT_dump_deserialized_pch_decls);
+  for (arg_iterator it = Args.filtered_begin(OPT_error_on_deserialized_pch_decl),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    Opts.DeserializedPCHDeclsToErrorOn.insert(A->getValue(Args));
+  }
+
+  if (const Arg *A = Args.getLastArg(OPT_preamble_bytes_EQ)) {
+    StringRef Value(A->getValue(Args));
+    size_t Comma = Value.find(',');
+    unsigned Bytes = 0;
+    unsigned EndOfLine = 0;
+
+    if (Comma == StringRef::npos ||
+        Value.substr(0, Comma).getAsInteger(10, Bytes) ||
+        Value.substr(Comma + 1).getAsInteger(10, EndOfLine))
+      Diags.Report(diag::err_drv_preamble_format);
+    else {
+      Opts.PrecompiledPreambleBytes.first = Bytes;
+      Opts.PrecompiledPreambleBytes.second = (EndOfLine != 0);
+    }
+  }
+
+  // Add macros from the command line.
+  for (arg_iterator it = Args.filtered_begin(OPT_D, OPT_U),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(OPT_D))
+      Opts.addMacroDef((*it)->getValue(Args));
+    else
+      Opts.addMacroUndef((*it)->getValue(Args));
+  }
+
+  Opts.MacroIncludes = Args.getAllArgValues(OPT_imacros);
+
+  // Add the ordered list of -includes.
+  for (arg_iterator it = Args.filtered_begin(OPT_include, OPT_include_pch,
+                                             OPT_include_pth),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    // PCH is handled specially, we need to extra the original include path.
+    if (A->getOption().matches(OPT_include_pch)) {
+      std::string OriginalFile =
+        ASTReader::getOriginalSourceFile(A->getValue(Args), FileMgr, Diags);
+      if (OriginalFile.empty())
+        continue;
+
+      Opts.Includes.push_back(OriginalFile);
+    } else
+      Opts.Includes.push_back(A->getValue(Args));
+  }
+
+  for (arg_iterator it = Args.filtered_begin(OPT_chain_include),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    Opts.ChainedIncludes.push_back(A->getValue(Args));
+  }
+
+  // Include 'altivec.h' if -faltivec option present
+  if (Args.hasArg(OPT_faltivec))
+    Opts.Includes.push_back("altivec.h");
+
+  for (arg_iterator it = Args.filtered_begin(OPT_remap_file),
+         ie = Args.filtered_end(); it != ie; ++it) {
+    const Arg *A = *it;
+    std::pair<StringRef,StringRef> Split =
+      StringRef(A->getValue(Args)).split(';');
+
+    if (Split.second.empty()) {
+      Diags.Report(diag::err_drv_invalid_remap_file) << A->getAsString(Args);
+      continue;
+    }
+
+    Opts.addRemappedFile(Split.first, Split.second);
+  }
+  
+  if (Arg *A = Args.getLastArg(OPT_fobjc_arc_cxxlib_EQ)) {
+    StringRef Name = A->getValue(Args);
+    unsigned Library = llvm::StringSwitch<unsigned>(Name)
+      .Case("libc++", ARCXX_libcxx)
+      .Case("libstdc++", ARCXX_libstdcxx)
+      .Case("none", ARCXX_nolib)
+      .Default(~0U);
+    if (Library == ~0U)
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
+    else
+      Opts.ObjCXXARCStandardLibrary = (ObjCXXARCStandardLibraryKind)Library;
+  }
+}
+
+static void ParsePreprocessorOutputArgs(PreprocessorOutputOptions &Opts,
+                                        ArgList &Args) {
+  using namespace cc1options;
+  Opts.ShowCPP = !Args.hasArg(OPT_dM);
+  Opts.ShowComments = Args.hasArg(OPT_C);
+  Opts.ShowLineMarkers = !Args.hasArg(OPT_P);
+  Opts.ShowMacroComments = Args.hasArg(OPT_CC);
+  Opts.ShowMacros = Args.hasArg(OPT_dM) || Args.hasArg(OPT_dD);
+}
+
+static void ParseTargetArgs(TargetOptions &Opts, ArgList &Args) {
+  using namespace cc1options;
+  Opts.ABI = Args.getLastArgValue(OPT_target_abi);
+  Opts.CXXABI = Args.getLastArgValue(OPT_cxx_abi);
+  Opts.CPU = Args.getLastArgValue(OPT_target_cpu);
+  Opts.Features = Args.getAllArgValues(OPT_target_feature);
+  Opts.LinkerVersion = Args.getLastArgValue(OPT_target_linker_version);
+  Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
+
+  // Use the default target triple if unspecified.
+  if (Opts.Triple.empty())
+    Opts.Triple = llvm::sys::getDefaultTargetTriple();
+}
+
+//
+
+bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
+                                        const char *const *ArgBegin,
+                                        const char *const *ArgEnd,
+                                        DiagnosticsEngine &Diags) {
+  bool Success = true;
+
+  // Parse the arguments.
+  OwningPtr<OptTable> Opts(createCC1OptTable());
+  unsigned MissingArgIndex, MissingArgCount;
+  OwningPtr<InputArgList> Args(
+    Opts->ParseArgs(ArgBegin, ArgEnd,MissingArgIndex, MissingArgCount));
+
+  // Check for missing argument error.
+  if (MissingArgCount) {
+    Diags.Report(diag::err_drv_missing_argument)
+      << Args->getArgString(MissingArgIndex) << MissingArgCount;
+    Success = false;
+  }
+
+  // Issue errors on unknown arguments.
+  for (arg_iterator it = Args->filtered_begin(OPT_UNKNOWN),
+         ie = Args->filtered_end(); it != ie; ++it) {
+    Diags.Report(diag::err_drv_unknown_argument) << (*it)->getAsString(*Args);
+    Success = false;
+  }
+
+  Success = ParseAnalyzerArgs(Res.getAnalyzerOpts(), *Args, Diags) && Success;
+  Success = ParseMigratorArgs(Res.getMigratorOpts(), *Args) && Success;
+  ParseDependencyOutputArgs(Res.getDependencyOutputOpts(), *Args);
+  Success = ParseDiagnosticArgs(Res.getDiagnosticOpts(), *Args, &Diags)
+            && Success;
+  ParseFileSystemArgs(Res.getFileSystemOpts(), *Args);
+  // FIXME: We shouldn't have to pass the DashX option around here
+  InputKind DashX = ParseFrontendArgs(Res.getFrontendOpts(), *Args, Diags);
+  Success = ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags)
+            && Success;
+  ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), *Args);
+  if (DashX != IK_AST && DashX != IK_LLVM_IR) {
+    ParseLangArgs(*Res.getLangOpts(), *Args, DashX, Diags);
+    if (Res.getFrontendOpts().ProgramAction == frontend::RewriteObjC)
+      Res.getLangOpts()->ObjCExceptions = 1;
+  }
+  // FIXME: ParsePreprocessorArgs uses the FileManager to read the contents of
+  // PCH file and find the original header name. Remove the need to do that in
+  // ParsePreprocessorArgs and remove the FileManager 
+  // parameters from the function and the "FileManager.h" #include.
+  FileManager FileMgr(Res.getFileSystemOpts());
+  ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args, FileMgr, Diags);
+  ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args);
+  ParseTargetArgs(Res.getTargetOpts(), *Args);
+
+  return Success;
+}
+
+namespace {
+
+  class ModuleSignature {
+    llvm::SmallVector<uint64_t, 16> Data;
+    unsigned CurBit;
+    uint64_t CurValue;
+    
+  public:
+    ModuleSignature() : CurBit(0), CurValue(0) { }
+    
+    void add(uint64_t Value, unsigned Bits);
+    void add(StringRef Value);
+    void flush();
+    
+    llvm::APInt getAsInteger() const;
+  };
+}
+
+void ModuleSignature::add(uint64_t Value, unsigned int NumBits) {
+  CurValue |= Value << CurBit;
+  if (CurBit + NumBits < 64) {
+    CurBit += NumBits;
+    return;
+  }
+  
+  // Add the current word.
+  Data.push_back(CurValue);
+  
+  if (CurBit)
+    CurValue = Value >> (64-CurBit);
+  else
+    CurValue = 0;
+  CurBit = (CurBit+NumBits) & 63;
+}
+
+void ModuleSignature::flush() {
+  if (CurBit == 0)
+    return;
+  
+  Data.push_back(CurValue);
+  CurBit = 0;
+  CurValue = 0;
+}
+
+void ModuleSignature::add(StringRef Value) {
+  for (StringRef::iterator I = Value.begin(), IEnd = Value.end(); I != IEnd;++I)
+    add(*I, 8);
+}
+
+llvm::APInt ModuleSignature::getAsInteger() const {
+  return llvm::APInt(Data.size() * 64, Data);
+}
+
+std::string CompilerInvocation::getModuleHash() const {
+  ModuleSignature Signature;
+  
+  // Start the signature with the compiler version.
+  // FIXME: The full version string can be quite long.  Omit it from the
+  // module hash for now to avoid failures where the path name becomes too
+  // long.  An MD5 or similar checksum would work well here.
+  // Signature.add(getClangFullRepositoryVersion());
+  
+  // Extend the signature with the language options
+#define LANGOPT(Name, Bits, Default, Description) \
+  Signature.add(LangOpts->Name, Bits);
+#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
+  Signature.add(static_cast<unsigned>(LangOpts->get##Name()), Bits);
+#define BENIGN_LANGOPT(Name, Bits, Default, Description)
+#define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
+#include "clang/Basic/LangOptions.def"
+  
+  // Extend the signature with the target triple
+  llvm::Triple T(TargetOpts.Triple);
+  Signature.add((unsigned)T.getArch(), 5);
+  Signature.add((unsigned)T.getVendor(), 4);
+  Signature.add((unsigned)T.getOS(), 5);
+  Signature.add((unsigned)T.getEnvironment(), 4);
+
+  // Extend the signature with preprocessor options.
+  Signature.add(getPreprocessorOpts().UsePredefines, 1);
+  Signature.add(getPreprocessorOpts().DetailedRecord, 1);
+  
+  // Hash the preprocessor defines.
+  // FIXME: This is terrible. Use an MD5 sum of the preprocessor defines.
+  std::vector<StringRef> MacroDefs;
+  for (std::vector<std::pair<std::string, bool/*isUndef*/> >::const_iterator 
+            I = getPreprocessorOpts().Macros.begin(),
+         IEnd = getPreprocessorOpts().Macros.end();
+       I != IEnd; ++I) {
+    if (!I->second)
+      MacroDefs.push_back(I->first);
+  }
+  llvm::array_pod_sort(MacroDefs.begin(), MacroDefs.end());
+       
+  unsigned PPHashResult = 0;
+  for (unsigned I = 0, N = MacroDefs.size(); I != N; ++I)
+    PPHashResult = llvm::HashString(MacroDefs[I], PPHashResult);
+  Signature.add(PPHashResult, 32);
+  
+  // We've generated the signature. Treat it as one large APInt that we'll
+  // encode in base-36 and return.
+  Signature.flush();
+  return Signature.getAsInteger().toString(36, /*Signed=*/false);
+}
diff --git a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
new file mode 100644
index 0000000..b477ade
--- /dev/null
+++ b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
@@ -0,0 +1,91 @@
+//===--- CreateInvocationFromCommandLine.cpp - CompilerInvocation from Args ==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Construct a compiler invocation object for command line driver arguments
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Driver/Compilation.h"
+#include "clang/Driver/Driver.h"
+#include "clang/Driver/ArgList.h"
+#include "clang/Driver/Options.h"
+#include "clang/Driver/Tool.h"
+#include "llvm/Support/Host.h"
+using namespace clang;
+
+/// createInvocationFromCommandLine - Construct a compiler invocation object for
+/// a command line argument vector.
+///
+/// \return A CompilerInvocation, or 0 if none was built for the given
+/// argument vector.
+CompilerInvocation *
+clang::createInvocationFromCommandLine(ArrayRef<const char *> ArgList,
+                            IntrusiveRefCntPtr<DiagnosticsEngine> Diags) {
+  if (!Diags.getPtr()) {
+    // No diagnostics engine was provided, so create our own diagnostics object
+    // with the default options.
+    DiagnosticOptions DiagOpts;
+    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgList.size(),
+                                                ArgList.begin());
+  }
+
+  SmallVector<const char *, 16> Args;
+  Args.push_back("<clang>"); // FIXME: Remove dummy argument.
+  Args.insert(Args.end(), ArgList.begin(), ArgList.end());
+
+  // FIXME: Find a cleaner way to force the driver into restricted modes. We
+  // also want to force it to use clang.
+  Args.push_back("-fsyntax-only");
+
+  // FIXME: We shouldn't have to pass in the path info.
+  driver::Driver TheDriver("clang", llvm::sys::getDefaultTargetTriple(),
+                           "a.out", false, *Diags);
+
+  // Don't check that inputs exist, they may have been remapped.
+  TheDriver.setCheckInputsExist(false);
+
+  OwningPtr<driver::Compilation> C(TheDriver.BuildCompilation(Args));
+
+  // Just print the cc1 options if -### was present.
+  if (C->getArgs().hasArg(driver::options::OPT__HASH_HASH_HASH)) {
+    C->PrintJob(llvm::errs(), C->getJobs(), "\n", true);
+    return 0;
+  }
+
+  // We expect to get back exactly one command job, if we didn't something
+  // failed.
+  const driver::JobList &Jobs = C->getJobs();
+  if (Jobs.size() != 1 || !isa<driver::Command>(*Jobs.begin())) {
+    SmallString<256> Msg;
+    llvm::raw_svector_ostream OS(Msg);
+    C->PrintJob(OS, C->getJobs(), "; ", true);
+    Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
+    return 0;
+  }
+
+  const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
+  if (StringRef(Cmd->getCreator().getName()) != "clang") {
+    Diags->Report(diag::err_fe_expected_clang_command);
+    return 0;
+  }
+
+  const driver::ArgStringList &CCArgs = Cmd->getArguments();
+  OwningPtr<CompilerInvocation> CI(new CompilerInvocation());
+  if (!CompilerInvocation::CreateFromArgs(*CI,
+                                     const_cast<const char **>(CCArgs.data()),
+                                     const_cast<const char **>(CCArgs.data()) +
+                                     CCArgs.size(),
+                                     *Diags))
+    return 0;
+  return CI.take();
+}
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
new file mode 100644
index 0000000..21f5daa
--- /dev/null
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -0,0 +1,231 @@
+//===--- DependencyFile.cpp - Generate dependency file --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code generates dependency files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DependencyOutputOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/DirectoryLookup.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+
+namespace {
+class DependencyFileCallback : public PPCallbacks {
+  std::vector<std::string> Files;
+  llvm::StringSet<> FilesSet;
+  const Preprocessor *PP;
+  std::string OutputFile;
+  std::vector<std::string> Targets;
+  bool IncludeSystemHeaders;
+  bool PhonyTarget;
+  bool AddMissingHeaderDeps;
+  bool SeenMissingHeader;
+private:
+  bool FileMatchesDepCriteria(const char *Filename,
+                              SrcMgr::CharacteristicKind FileType);
+  void AddFilename(StringRef Filename);
+  void OutputDependencyFile();
+
+public:
+  DependencyFileCallback(const Preprocessor *_PP,
+                         const DependencyOutputOptions &Opts)
+    : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
+      IncludeSystemHeaders(Opts.IncludeSystemHeaders),
+      PhonyTarget(Opts.UsePhonyTargets),
+      AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
+      SeenMissingHeader(false) {}
+
+  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                           SrcMgr::CharacteristicKind FileType,
+                           FileID PrevFID);
+  virtual void InclusionDirective(SourceLocation HashLoc,
+                                  const Token &IncludeTok,
+                                  StringRef FileName,
+                                  bool IsAngled,
+                                  const FileEntry *File,
+                                  SourceLocation EndLoc,
+                                  StringRef SearchPath,
+                                  StringRef RelativePath);
+
+  virtual void EndOfMainFile() {
+    OutputDependencyFile();
+  }
+};
+}
+
+void clang::AttachDependencyFileGen(Preprocessor &PP,
+                                    const DependencyOutputOptions &Opts) {
+  if (Opts.Targets.empty()) {
+    PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
+    return;
+  }
+
+  // Disable the "file not found" diagnostic if the -MG option was given.
+  if (Opts.AddMissingHeaderDeps)
+    PP.SetSuppressIncludeNotFoundError(true);
+
+  PP.addPPCallbacks(new DependencyFileCallback(&PP, Opts));
+}
+
+/// FileMatchesDepCriteria - Determine whether the given Filename should be
+/// considered as a dependency.
+bool DependencyFileCallback::FileMatchesDepCriteria(const char *Filename,
+                                          SrcMgr::CharacteristicKind FileType) {
+  if (strcmp("<built-in>", Filename) == 0)
+    return false;
+
+  if (IncludeSystemHeaders)
+    return true;
+
+  return FileType == SrcMgr::C_User;
+}
+
+void DependencyFileCallback::FileChanged(SourceLocation Loc,
+                                         FileChangeReason Reason,
+                                         SrcMgr::CharacteristicKind FileType,
+                                         FileID PrevFID) {
+  if (Reason != PPCallbacks::EnterFile)
+    return;
+
+  // Dependency generation really does want to go all the way to the
+  // file entry for a source location to find out what is depended on.
+  // We do not want #line markers to affect dependency generation!
+  SourceManager &SM = PP->getSourceManager();
+
+  const FileEntry *FE =
+    SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
+  if (FE == 0) return;
+
+  StringRef Filename = FE->getName();
+  if (!FileMatchesDepCriteria(Filename.data(), FileType))
+    return;
+
+  // Remove leading "./" (or ".//" or "././" etc.)
+  while (Filename.size() > 2 && Filename[0] == '.' &&
+         llvm::sys::path::is_separator(Filename[1])) {
+    Filename = Filename.substr(1);
+    while (llvm::sys::path::is_separator(Filename[0]))
+      Filename = Filename.substr(1);
+  }
+    
+  AddFilename(Filename);
+}
+
+void DependencyFileCallback::InclusionDirective(SourceLocation HashLoc,
+                                                const Token &IncludeTok,
+                                                StringRef FileName,
+                                                bool IsAngled,
+                                                const FileEntry *File,
+                                                SourceLocation EndLoc,
+                                                StringRef SearchPath,
+                                                StringRef RelativePath) {
+  if (!File) {
+    if (AddMissingHeaderDeps)
+      AddFilename(FileName);
+    else
+      SeenMissingHeader = true;
+  }
+}
+
+void DependencyFileCallback::AddFilename(StringRef Filename) {
+  if (FilesSet.insert(Filename))
+    Files.push_back(Filename);
+}
+
+/// PrintFilename - GCC escapes spaces, but apparently not ' or " or other
+/// scary characters.
+static void PrintFilename(raw_ostream &OS, StringRef Filename) {
+  for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
+    if (Filename[i] == ' ')
+      OS << '\\';
+    OS << Filename[i];
+  }
+}
+
+void DependencyFileCallback::OutputDependencyFile() {
+  if (SeenMissingHeader) {
+    llvm::sys::Path(OutputFile).eraseFromDisk();
+    return;
+  }
+
+  std::string Err;
+  llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
+  if (!Err.empty()) {
+    PP->getDiagnostics().Report(diag::err_fe_error_opening)
+      << OutputFile << Err;
+    return;
+  }
+
+  // Write out the dependency targets, trying to avoid overly long
+  // lines when possible. We try our best to emit exactly the same
+  // dependency file as GCC (4.2), assuming the included files are the
+  // same.
+  const unsigned MaxColumns = 75;
+  unsigned Columns = 0;
+
+  for (std::vector<std::string>::iterator
+         I = Targets.begin(), E = Targets.end(); I != E; ++I) {
+    unsigned N = I->length();
+    if (Columns == 0) {
+      Columns += N;
+    } else if (Columns + N + 2 > MaxColumns) {
+      Columns = N + 2;
+      OS << " \\\n  ";
+    } else {
+      Columns += N + 1;
+      OS << ' ';
+    }
+    // Targets already quoted as needed.
+    OS << *I;
+  }
+
+  OS << ':';
+  Columns += 1;
+
+  // Now add each dependency in the order it was seen, but avoiding
+  // duplicates.
+  for (std::vector<std::string>::iterator I = Files.begin(),
+         E = Files.end(); I != E; ++I) {
+    // Start a new line if this would exceed the column limit. Make
+    // sure to leave space for a trailing " \" in case we need to
+    // break the line on the next iteration.
+    unsigned N = I->length();
+    if (Columns + (N + 1) + 2 > MaxColumns) {
+      OS << " \\\n ";
+      Columns = 2;
+    }
+    OS << ' ';
+    PrintFilename(OS, *I);
+    Columns += N + 1;
+  }
+  OS << '\n';
+
+  // Create phony targets if requested.
+  if (PhonyTarget && !Files.empty()) {
+    // Skip the first entry, this is always the input file itself.
+    for (std::vector<std::string>::iterator I = Files.begin() + 1,
+           E = Files.end(); I != E; ++I) {
+      OS << '\n';
+      PrintFilename(OS, *I);
+      OS << ":\n";
+    }
+  }
+}
+
diff --git a/clang/lib/Frontend/DependencyGraph.cpp b/clang/lib/Frontend/DependencyGraph.cpp
new file mode 100644
index 0000000..eebaf0c
--- /dev/null
+++ b/clang/lib/Frontend/DependencyGraph.cpp
@@ -0,0 +1,140 @@
+//===--- DependencyGraph.cpp - Generate dependency file -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code generates a header dependency graph in DOT format, for use
+// with, e.g., GraphViz.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/GraphWriter.h"
+
+using namespace clang;
+namespace DOT = llvm::DOT;
+
+namespace {
+class DependencyGraphCallback : public PPCallbacks {
+  const Preprocessor *PP;
+  std::string OutputFile;
+  std::string SysRoot;
+  llvm::SetVector<const FileEntry *> AllFiles;
+  typedef llvm::DenseMap<const FileEntry *, 
+                         llvm::SmallVector<const FileEntry *, 2> >
+    DependencyMap;
+  
+  DependencyMap Dependencies;
+  
+private:
+  llvm::raw_ostream &writeNodeReference(llvm::raw_ostream &OS,
+                                        const FileEntry *Node);
+  void OutputGraphFile();
+
+public:
+  DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
+                          StringRef SysRoot)
+    : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
+
+  virtual void InclusionDirective(SourceLocation HashLoc,
+                                  const Token &IncludeTok,
+                                  StringRef FileName,
+                                  bool IsAngled,
+                                  const FileEntry *File,
+                                  SourceLocation EndLoc,
+                                  StringRef SearchPath,
+                                  StringRef RelativePath);
+
+  virtual void EndOfMainFile() {
+    OutputGraphFile();
+  }
+  
+};
+}
+
+void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
+                                     StringRef SysRoot) {
+  PP.addPPCallbacks(new DependencyGraphCallback(&PP, OutputFile, SysRoot));
+}
+
+void DependencyGraphCallback::InclusionDirective(SourceLocation HashLoc,
+                                                 const Token &IncludeTok,
+                                                 StringRef FileName,
+                                                 bool IsAngled,
+                                                 const FileEntry *File,
+                                                 SourceLocation EndLoc,
+                                                 StringRef SearchPath,
+                                                 StringRef RelativePath) {
+  if (!File)
+    return;
+  
+  SourceManager &SM = PP->getSourceManager();
+  const FileEntry *FromFile
+    = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
+  if (FromFile == 0) 
+    return;
+
+  Dependencies[FromFile].push_back(File);
+  
+  AllFiles.insert(File);
+  AllFiles.insert(FromFile);
+}
+
+llvm::raw_ostream &
+DependencyGraphCallback::writeNodeReference(llvm::raw_ostream &OS,
+                                            const FileEntry *Node) {
+  OS << "header_" << Node->getUID();
+  return OS;
+}
+
+void DependencyGraphCallback::OutputGraphFile() {
+  std::string Err;
+  llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
+  if (!Err.empty()) {
+    PP->getDiagnostics().Report(diag::err_fe_error_opening)
+      << OutputFile << Err;
+    return;
+  }
+
+  OS << "digraph \"dependencies\" {\n";
+  
+  // Write the nodes
+  for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
+    // Write the node itself.
+    OS.indent(2);
+    writeNodeReference(OS, AllFiles[I]);
+    OS << " [ shape=\"box\", label=\"";
+    StringRef FileName = AllFiles[I]->getName();
+    if (FileName.startswith(SysRoot))
+      FileName = FileName.substr(SysRoot.size());
+    
+    OS << DOT::EscapeString(FileName)
+    << "\"];\n";
+  }
+
+  // Write the edges
+  for (DependencyMap::iterator F = Dependencies.begin(), 
+                            FEnd = Dependencies.end();
+       F != FEnd; ++F) {    
+    for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
+      OS.indent(2);
+      writeNodeReference(OS, F->first);
+      OS << " -> ";
+      writeNodeReference(OS, F->second[I]);
+      OS << ";\n";
+    }
+  }
+  OS << "}\n";
+}
+
diff --git a/clang/lib/Frontend/DiagnosticRenderer.cpp b/clang/lib/Frontend/DiagnosticRenderer.cpp
new file mode 100644
index 0000000..6c3bb1d
--- /dev/null
+++ b/clang/lib/Frontend/DiagnosticRenderer.cpp
@@ -0,0 +1,386 @@
+//===--- DiagnosticRenderer.cpp - Diagnostic Pretty-Printing --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/DiagnosticRenderer.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Edit/EditedSource.h"
+#include "clang/Edit/Commit.h"
+#include "clang/Edit/EditsReceiver.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/SmallString.h"
+#include <algorithm>
+using namespace clang;
+
+/// Look through spelling locations for a macro argument expansion, and
+/// if found skip to it so that we can trace the argument rather than the macros
+/// in which that argument is used. If no macro argument expansion is found,
+/// don't skip anything and return the starting location.
+static SourceLocation skipToMacroArgExpansion(const SourceManager &SM,
+                                              SourceLocation StartLoc) {
+  for (SourceLocation L = StartLoc; L.isMacroID();
+       L = SM.getImmediateSpellingLoc(L)) {
+    if (SM.isMacroArgExpansion(L))
+      return L;
+  }
+  
+  // Otherwise just return initial location, there's nothing to skip.
+  return StartLoc;
+}
+
+/// Gets the location of the immediate macro caller, one level up the stack
+/// toward the initial macro typed into the source.
+static SourceLocation getImmediateMacroCallerLoc(const SourceManager &SM,
+                                                 SourceLocation Loc) {
+  if (!Loc.isMacroID()) return Loc;
+  
+  // When we have the location of (part of) an expanded parameter, its spelling
+  // location points to the argument as typed into the macro call, and
+  // therefore is used to locate the macro caller.
+  if (SM.isMacroArgExpansion(Loc))
+    return SM.getImmediateSpellingLoc(Loc);
+  
+  // Otherwise, the caller of the macro is located where this macro is
+  // expanded (while the spelling is part of the macro definition).
+  return SM.getImmediateExpansionRange(Loc).first;
+}
+
+/// Gets the location of the immediate macro callee, one level down the stack
+/// toward the leaf macro.
+static SourceLocation getImmediateMacroCalleeLoc(const SourceManager &SM,
+                                                 SourceLocation Loc) {
+  if (!Loc.isMacroID()) return Loc;
+  
+  // When we have the location of (part of) an expanded parameter, its
+  // expansion location points to the unexpanded paramater reference within
+  // the macro definition (or callee).
+  if (SM.isMacroArgExpansion(Loc))
+    return SM.getImmediateExpansionRange(Loc).first;
+  
+  // Otherwise, the callee of the macro is located where this location was
+  // spelled inside the macro definition.
+  return SM.getImmediateSpellingLoc(Loc);
+}
+
+/// \brief Retrieve the name of the immediate macro expansion.
+///
+/// This routine starts from a source location, and finds the name of the macro
+/// responsible for its immediate expansion. It looks through any intervening
+/// macro argument expansions to compute this. It returns a StringRef which
+/// refers to the SourceManager-owned buffer of the source where that macro
+/// name is spelled. Thus, the result shouldn't out-live that SourceManager.
+///
+/// This differs from Lexer::getImmediateMacroName in that any macro argument
+/// location will result in the topmost function macro that accepted it.
+/// e.g.
+/// \code
+///   MAC1( MAC2(foo) )
+/// \endcode
+/// for location of 'foo' token, this function will return "MAC1" while
+/// Lexer::getImmediateMacroName will return "MAC2".
+static StringRef getImmediateMacroName(SourceLocation Loc,
+                                       const SourceManager &SM,
+                                       const LangOptions &LangOpts) {
+   assert(Loc.isMacroID() && "Only reasonble to call this on macros");
+   // Walk past macro argument expanions.
+   while (SM.isMacroArgExpansion(Loc))
+     Loc = SM.getImmediateExpansionRange(Loc).first;
+
+   // Find the spelling location of the start of the non-argument expansion
+   // range. This is where the macro name was spelled in order to begin
+   // expanding this macro.
+   Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
+
+   // Dig out the buffer where the macro name was spelled and the extents of the
+   // name so that we can render it into the expansion note.
+   std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
+   unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
+   StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
+   return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
+}
+
+/// Get the presumed location of a diagnostic message. This computes the
+/// presumed location for the top of any macro backtrace when present.
+static PresumedLoc getDiagnosticPresumedLoc(const SourceManager &SM,
+                                            SourceLocation Loc) {
+  // This is a condensed form of the algorithm used by emitCaretDiagnostic to
+  // walk to the top of the macro call stack.
+  while (Loc.isMacroID()) {
+    Loc = skipToMacroArgExpansion(SM, Loc);
+    Loc = getImmediateMacroCallerLoc(SM, Loc);
+  }
+  
+  return SM.getPresumedLoc(Loc);
+}
+
+DiagnosticRenderer::DiagnosticRenderer(const SourceManager &SM,
+                                       const LangOptions &LangOpts,
+                                       const DiagnosticOptions &DiagOpts)
+: SM(SM), LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
+
+DiagnosticRenderer::~DiagnosticRenderer() {}
+
+namespace {
+
+class FixitReceiver : public edit::EditsReceiver {
+  SmallVectorImpl<FixItHint> &MergedFixits;
+
+public:
+  FixitReceiver(SmallVectorImpl<FixItHint> &MergedFixits)
+    : MergedFixits(MergedFixits) { }
+  virtual void insert(SourceLocation loc, StringRef text) {
+    MergedFixits.push_back(FixItHint::CreateInsertion(loc, text));
+  }
+  virtual void replace(CharSourceRange range, StringRef text) {
+    MergedFixits.push_back(FixItHint::CreateReplacement(range, text));
+  }
+};
+
+}
+
+static void mergeFixits(ArrayRef<FixItHint> FixItHints,
+                        const SourceManager &SM, const LangOptions &LangOpts,
+                        SmallVectorImpl<FixItHint> &MergedFixits) {
+  edit::Commit commit(SM, LangOpts);
+  for (ArrayRef<FixItHint>::const_iterator
+         I = FixItHints.begin(), E = FixItHints.end(); I != E; ++I) {
+    const FixItHint &Hint = *I;
+    if (Hint.CodeToInsert.empty()) {
+      if (Hint.InsertFromRange.isValid())
+        commit.insertFromRange(Hint.RemoveRange.getBegin(),
+                           Hint.InsertFromRange, /*afterToken=*/false,
+                           Hint.BeforePreviousInsertions);
+      else
+        commit.remove(Hint.RemoveRange);
+    } else {
+      if (Hint.RemoveRange.isTokenRange() ||
+          Hint.RemoveRange.getBegin() != Hint.RemoveRange.getEnd())
+        commit.replace(Hint.RemoveRange, Hint.CodeToInsert);
+      else
+        commit.insert(Hint.RemoveRange.getBegin(), Hint.CodeToInsert,
+                    /*afterToken=*/false, Hint.BeforePreviousInsertions);
+    }
+  }
+
+  edit::EditedSource Editor(SM, LangOpts);
+  if (Editor.commit(commit)) {
+    FixitReceiver Rec(MergedFixits);
+    Editor.applyRewrites(Rec);
+  }
+}
+
+void DiagnosticRenderer::emitDiagnostic(SourceLocation Loc,
+                                        DiagnosticsEngine::Level Level,
+                                        StringRef Message,
+                                        ArrayRef<CharSourceRange> Ranges,
+                                        ArrayRef<FixItHint> FixItHints,
+                                        DiagOrStoredDiag D) {
+  
+  beginDiagnostic(D, Level);
+  
+  PresumedLoc PLoc = getDiagnosticPresumedLoc(SM, Loc);
+  
+  // First, if this diagnostic is not in the main file, print out the
+  // "included from" lines.
+  emitIncludeStack(PLoc.getIncludeLoc(), Level);
+  
+  // Next, emit the actual diagnostic message.
+  emitDiagnosticMessage(Loc, PLoc, Level, Message, Ranges, D);
+  
+  // Only recurse if we have a valid location.
+  if (Loc.isValid()) {
+    // Get the ranges into a local array we can hack on.
+    SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
+                                                   Ranges.end());
+    
+    llvm::SmallVector<FixItHint, 8> MergedFixits;
+    if (!FixItHints.empty()) {
+      mergeFixits(FixItHints, SM, LangOpts, MergedFixits);
+      FixItHints = MergedFixits;
+    }
+
+    for (ArrayRef<FixItHint>::const_iterator I = FixItHints.begin(),
+         E = FixItHints.end();
+         I != E; ++I)
+      if (I->RemoveRange.isValid())
+        MutableRanges.push_back(I->RemoveRange);
+    
+    unsigned MacroDepth = 0;
+    emitMacroExpansionsAndCarets(Loc, Level, MutableRanges, FixItHints,
+                                 MacroDepth);
+  }
+  
+  LastLoc = Loc;
+  LastLevel = Level;
+  
+  endDiagnostic(D, Level);
+}
+
+
+void DiagnosticRenderer::emitStoredDiagnostic(StoredDiagnostic &Diag) {
+  emitDiagnostic(Diag.getLocation(), Diag.getLevel(), Diag.getMessage(),
+                 Diag.getRanges(), Diag.getFixIts(),
+                 &Diag);
+}
+
+/// \brief Prints an include stack when appropriate for a particular
+/// diagnostic level and location.
+///
+/// This routine handles all the logic of suppressing particular include
+/// stacks (such as those for notes) and duplicate include stacks when
+/// repeated warnings occur within the same file. It also handles the logic
+/// of customizing the formatting and display of the include stack.
+///
+/// \param Level The diagnostic level of the message this stack pertains to.
+/// \param Loc   The include location of the current file (not the diagnostic
+///              location).
+void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
+                                          DiagnosticsEngine::Level Level) {
+  // Skip redundant include stacks altogether.
+  if (LastIncludeLoc == Loc)
+    return;
+  LastIncludeLoc = Loc;
+  
+  if (!DiagOpts.ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
+    return;
+  
+  emitIncludeStackRecursively(Loc);
+}
+
+/// \brief Helper to recursivly walk up the include stack and print each layer
+/// on the way back down.
+void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc) {
+  if (Loc.isInvalid())
+    return;
+  
+  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
+  if (PLoc.isInvalid())
+    return;
+  
+  // Emit the other include frames first.
+  emitIncludeStackRecursively(PLoc.getIncludeLoc());
+  
+  // Emit the inclusion text/note.
+  emitIncludeLocation(Loc, PLoc);
+}
+
+/// \brief Recursively emit notes for each macro expansion and caret
+/// diagnostics where appropriate.
+///
+/// Walks up the macro expansion stack printing expansion notes, the code
+/// snippet, caret, underlines and FixItHint display as appropriate at each
+/// level.
+///
+/// \param Loc The location for this caret.
+/// \param Level The diagnostic level currently being emitted.
+/// \param Ranges The underlined ranges for this code snippet.
+/// \param Hints The FixIt hints active for this diagnostic.
+/// \param MacroSkipEnd The depth to stop skipping macro expansions.
+/// \param OnMacroInst The current depth of the macro expansion stack.
+void DiagnosticRenderer::emitMacroExpansionsAndCarets(
+       SourceLocation Loc,
+       DiagnosticsEngine::Level Level,
+       SmallVectorImpl<CharSourceRange>& Ranges,
+       ArrayRef<FixItHint> Hints,
+       unsigned &MacroDepth,
+       unsigned OnMacroInst)
+{
+  assert(!Loc.isInvalid() && "must have a valid source location here");
+  
+  // If this is a file source location, directly emit the source snippet and
+  // caret line. Also record the macro depth reached.
+  if (Loc.isFileID()) {
+    assert(MacroDepth == 0 && "We shouldn't hit a leaf node twice!");
+    MacroDepth = OnMacroInst;
+    emitCodeContext(Loc, Level, Ranges, Hints);
+    return;
+  }
+  // Otherwise recurse through each macro expansion layer.
+  
+  // When processing macros, skip over the expansions leading up to
+  // a macro argument, and trace the argument's expansion stack instead.
+  Loc = skipToMacroArgExpansion(SM, Loc);
+  
+  SourceLocation OneLevelUp = getImmediateMacroCallerLoc(SM, Loc);
+  
+  // FIXME: Map ranges?
+  emitMacroExpansionsAndCarets(OneLevelUp, Level, Ranges, Hints, MacroDepth,
+                               OnMacroInst + 1);
+  
+  // Save the original location so we can find the spelling of the macro call.
+  SourceLocation MacroLoc = Loc;
+  
+  // Map the location.
+  Loc = getImmediateMacroCalleeLoc(SM, Loc);
+  
+  unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
+  if (MacroDepth > DiagOpts.MacroBacktraceLimit &&
+      DiagOpts.MacroBacktraceLimit != 0) {
+    MacroSkipStart = DiagOpts.MacroBacktraceLimit / 2 +
+    DiagOpts.MacroBacktraceLimit % 2;
+    MacroSkipEnd = MacroDepth - DiagOpts.MacroBacktraceLimit / 2;
+  }
+  
+  // Whether to suppress printing this macro expansion.
+  bool Suppressed = (OnMacroInst >= MacroSkipStart &&
+                     OnMacroInst < MacroSkipEnd);
+  
+  // Map the ranges.
+  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
+       E = Ranges.end();
+       I != E; ++I) {
+    SourceLocation Start = I->getBegin(), End = I->getEnd();
+    if (Start.isMacroID())
+      I->setBegin(getImmediateMacroCalleeLoc(SM, Start));
+    if (End.isMacroID())
+      I->setEnd(getImmediateMacroCalleeLoc(SM, End));
+  }
+  
+  if (Suppressed) {
+    // Tell the user that we've skipped contexts.
+    if (OnMacroInst == MacroSkipStart) {
+      SmallString<200> MessageStorage;
+      llvm::raw_svector_ostream Message(MessageStorage);
+      Message << "(skipping " << (MacroSkipEnd - MacroSkipStart)
+              << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
+                 "see all)";
+      emitBasicNote(Message.str());      
+    }
+    return;
+  }
+  
+  SmallString<100> MessageStorage;
+  llvm::raw_svector_ostream Message(MessageStorage);
+  Message << "expanded from macro '"
+          << getImmediateMacroName(MacroLoc, SM, LangOpts) << "'";
+  emitDiagnostic(SM.getSpellingLoc(Loc), DiagnosticsEngine::Note,
+                 Message.str(),
+                 Ranges, ArrayRef<FixItHint>());
+}
+
+DiagnosticNoteRenderer::~DiagnosticNoteRenderer() {}
+
+void DiagnosticNoteRenderer::emitIncludeLocation(SourceLocation Loc,
+                                                 PresumedLoc PLoc) {
+  // Generate a note indicating the include location.
+  SmallString<200> MessageStorage;
+  llvm::raw_svector_ostream Message(MessageStorage);
+  Message << "in file included from " << PLoc.getFilename() << ':'
+          << PLoc.getLine() << ":";
+  emitNote(Loc, Message.str());
+}
+
+void DiagnosticNoteRenderer::emitBasicNote(StringRef Message) {
+  emitNote(SourceLocation(), Message);  
+}
+
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
new file mode 100644
index 0000000..da4bdfa
--- /dev/null
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -0,0 +1,468 @@
+//===--- FrontendAction.cpp -----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclGroup.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/ChainedIncludesSource.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendPluginRegistry.h"
+#include "clang/Frontend/LayoutOverrideSource.h"
+#include "clang/Frontend/MultiplexConsumer.h"
+#include "clang/Parse/ParseAST.h"
+#include "clang/Serialization/ASTDeserializationListener.h"
+#include "clang/Serialization/ASTReader.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace clang;
+
+namespace {
+
+class DelegatingDeserializationListener : public ASTDeserializationListener {
+  ASTDeserializationListener *Previous;
+
+public:
+  explicit DelegatingDeserializationListener(
+                                           ASTDeserializationListener *Previous)
+    : Previous(Previous) { }
+
+  virtual void ReaderInitialized(ASTReader *Reader) {
+    if (Previous)
+      Previous->ReaderInitialized(Reader);
+  }
+  virtual void IdentifierRead(serialization::IdentID ID,
+                              IdentifierInfo *II) {
+    if (Previous)
+      Previous->IdentifierRead(ID, II);
+  }
+  virtual void TypeRead(serialization::TypeIdx Idx, QualType T) {
+    if (Previous)
+      Previous->TypeRead(Idx, T);
+  }
+  virtual void DeclRead(serialization::DeclID ID, const Decl *D) {
+    if (Previous)
+      Previous->DeclRead(ID, D);
+  }
+  virtual void SelectorRead(serialization::SelectorID ID, Selector Sel) {
+    if (Previous)
+      Previous->SelectorRead(ID, Sel);
+  }
+  virtual void MacroDefinitionRead(serialization::PreprocessedEntityID PPID, 
+                                   MacroDefinition *MD) {
+    if (Previous)
+      Previous->MacroDefinitionRead(PPID, MD);
+  }
+};
+
+/// \brief Dumps deserialized declarations.
+class DeserializedDeclsDumper : public DelegatingDeserializationListener {
+public:
+  explicit DeserializedDeclsDumper(ASTDeserializationListener *Previous)
+    : DelegatingDeserializationListener(Previous) { }
+
+  virtual void DeclRead(serialization::DeclID ID, const Decl *D) {
+    llvm::outs() << "PCH DECL: " << D->getDeclKindName();
+    if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
+      llvm::outs() << " - " << *ND;
+    llvm::outs() << "\n";
+
+    DelegatingDeserializationListener::DeclRead(ID, D);
+  }
+};
+
+  /// \brief Checks deserialized declarations and emits error if a name
+  /// matches one given in command-line using -error-on-deserialized-decl.
+  class DeserializedDeclsChecker : public DelegatingDeserializationListener {
+    ASTContext &Ctx;
+    std::set<std::string> NamesToCheck;
+
+  public:
+    DeserializedDeclsChecker(ASTContext &Ctx,
+                             const std::set<std::string> &NamesToCheck, 
+                             ASTDeserializationListener *Previous)
+      : DelegatingDeserializationListener(Previous),
+        Ctx(Ctx), NamesToCheck(NamesToCheck) { }
+
+    virtual void DeclRead(serialization::DeclID ID, const Decl *D) {
+      if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
+        if (NamesToCheck.find(ND->getNameAsString()) != NamesToCheck.end()) {
+          unsigned DiagID
+            = Ctx.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error,
+                                                   "%0 was deserialized");
+          Ctx.getDiagnostics().Report(Ctx.getFullLoc(D->getLocation()), DiagID)
+              << ND->getNameAsString();
+        }
+
+      DelegatingDeserializationListener::DeclRead(ID, D);
+    }
+};
+
+} // end anonymous namespace
+
+FrontendAction::FrontendAction() : Instance(0) {}
+
+FrontendAction::~FrontendAction() {}
+
+void FrontendAction::setCurrentInput(const FrontendInputFile &CurrentInput,
+                                     ASTUnit *AST) {
+  this->CurrentInput = CurrentInput;
+  CurrentASTUnit.reset(AST);
+}
+
+ASTConsumer* FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
+                                                      StringRef InFile) {
+  ASTConsumer* Consumer = CreateASTConsumer(CI, InFile);
+  if (!Consumer)
+    return 0;
+
+  if (CI.getFrontendOpts().AddPluginActions.size() == 0)
+    return Consumer;
+
+  // Make sure the non-plugin consumer is first, so that plugins can't
+  // modifiy the AST.
+  std::vector<ASTConsumer*> Consumers(1, Consumer);
+
+  for (size_t i = 0, e = CI.getFrontendOpts().AddPluginActions.size();
+       i != e; ++i) { 
+    // This is O(|plugins| * |add_plugins|), but since both numbers are
+    // way below 50 in practice, that's ok.
+    for (FrontendPluginRegistry::iterator
+        it = FrontendPluginRegistry::begin(),
+        ie = FrontendPluginRegistry::end();
+        it != ie; ++it) {
+      if (it->getName() == CI.getFrontendOpts().AddPluginActions[i]) {
+        OwningPtr<PluginASTAction> P(it->instantiate());
+        FrontendAction* c = P.get();
+        if (P->ParseArgs(CI, CI.getFrontendOpts().AddPluginArgs[i]))
+          Consumers.push_back(c->CreateASTConsumer(CI, InFile));
+      }
+    }
+  }
+
+  return new MultiplexConsumer(Consumers);
+}
+
+bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
+                                     const FrontendInputFile &Input) {
+  assert(!Instance && "Already processing a source file!");
+  assert(!Input.File.empty() && "Unexpected empty filename!");
+  setCurrentInput(Input);
+  setCompilerInstance(&CI);
+
+  if (!BeginInvocation(CI))
+    goto failure;
+
+  // AST files follow a very different path, since they share objects via the
+  // AST unit.
+  if (Input.Kind == IK_AST) {
+    assert(!usesPreprocessorOnly() &&
+           "Attempt to pass AST file to preprocessor only action!");
+    assert(hasASTFileSupport() &&
+           "This action does not have AST file support!");
+
+    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
+    std::string Error;
+    ASTUnit *AST = ASTUnit::LoadFromASTFile(Input.File, Diags,
+                                            CI.getFileSystemOpts());
+    if (!AST)
+      goto failure;
+
+    setCurrentInput(Input, AST);
+
+    // Set the shared objects, these are reset when we finish processing the
+    // file, otherwise the CompilerInstance will happily destroy them.
+    CI.setFileManager(&AST->getFileManager());
+    CI.setSourceManager(&AST->getSourceManager());
+    CI.setPreprocessor(&AST->getPreprocessor());
+    CI.setASTContext(&AST->getASTContext());
+
+    // Initialize the action.
+    if (!BeginSourceFileAction(CI, Input.File))
+      goto failure;
+
+    /// Create the AST consumer.
+    CI.setASTConsumer(CreateWrappedASTConsumer(CI, Input.File));
+    if (!CI.hasASTConsumer())
+      goto failure;
+
+    return true;
+  }
+
+  // Set up the file and source managers, if needed.
+  if (!CI.hasFileManager())
+    CI.createFileManager();
+  if (!CI.hasSourceManager())
+    CI.createSourceManager(CI.getFileManager());
+
+  // IR files bypass the rest of initialization.
+  if (Input.Kind == IK_LLVM_IR) {
+    assert(hasIRSupport() &&
+           "This action does not have IR file support!");
+
+    // Inform the diagnostic client we are processing a source file.
+    CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), 0);
+
+    // Initialize the action.
+    if (!BeginSourceFileAction(CI, Input.File))
+      goto failure;
+
+    return true;
+  }
+
+  // Set up the preprocessor.
+  CI.createPreprocessor();
+
+  // Inform the diagnostic client we are processing a source file.
+  CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(),
+                                           &CI.getPreprocessor());
+
+  // Initialize the action.
+  if (!BeginSourceFileAction(CI, Input.File))
+    goto failure;
+
+  /// Create the AST context and consumer unless this is a preprocessor only
+  /// action.
+  if (!usesPreprocessorOnly()) {
+    CI.createASTContext();
+
+    OwningPtr<ASTConsumer> Consumer(
+                                   CreateWrappedASTConsumer(CI, Input.File));
+    if (!Consumer)
+      goto failure;
+
+    CI.getASTContext().setASTMutationListener(Consumer->GetASTMutationListener());
+
+    if (!CI.getPreprocessorOpts().ChainedIncludes.empty()) {
+      // Convert headers to PCH and chain them.
+      OwningPtr<ExternalASTSource> source;
+      source.reset(ChainedIncludesSource::create(CI));
+      if (!source)
+        goto failure;
+      CI.getASTContext().setExternalSource(source);
+
+    } else if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
+      // Use PCH.
+      assert(hasPCHSupport() && "This action does not have PCH support!");
+      ASTDeserializationListener *DeserialListener =
+          Consumer->GetASTDeserializationListener();
+      if (CI.getPreprocessorOpts().DumpDeserializedPCHDecls)
+        DeserialListener = new DeserializedDeclsDumper(DeserialListener);
+      if (!CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn.empty())
+        DeserialListener = new DeserializedDeclsChecker(CI.getASTContext(),
+                         CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn,
+                                                        DeserialListener);
+      CI.createPCHExternalASTSource(
+                                CI.getPreprocessorOpts().ImplicitPCHInclude,
+                                CI.getPreprocessorOpts().DisablePCHValidation,
+                                CI.getPreprocessorOpts().DisableStatCache,
+                            CI.getPreprocessorOpts().AllowPCHWithCompilerErrors,
+                                DeserialListener);
+      if (!CI.getASTContext().getExternalSource())
+        goto failure;
+    }
+
+    CI.setASTConsumer(Consumer.take());
+    if (!CI.hasASTConsumer())
+      goto failure;
+  }
+
+  // Initialize built-in info as long as we aren't using an external AST
+  // source.
+  if (!CI.hasASTContext() || !CI.getASTContext().getExternalSource()) {
+    Preprocessor &PP = CI.getPreprocessor();
+    PP.getBuiltinInfo().InitializeBuiltins(PP.getIdentifierTable(),
+                                           PP.getLangOpts());
+  }
+
+  // If there is a layout overrides file, attach an external AST source that
+  // provides the layouts from that file.
+  if (!CI.getFrontendOpts().OverrideRecordLayoutsFile.empty() && 
+      CI.hasASTContext() && !CI.getASTContext().getExternalSource()) {
+    OwningPtr<ExternalASTSource> 
+      Override(new LayoutOverrideSource(
+                     CI.getFrontendOpts().OverrideRecordLayoutsFile));
+    CI.getASTContext().setExternalSource(Override);
+  }
+  
+  return true;
+
+  // If we failed, reset state since the client will not end up calling the
+  // matching EndSourceFile().
+  failure:
+  if (isCurrentFileAST()) {
+    CI.setASTContext(0);
+    CI.setPreprocessor(0);
+    CI.setSourceManager(0);
+    CI.setFileManager(0);
+  }
+
+  CI.getDiagnosticClient().EndSourceFile();
+  setCurrentInput(FrontendInputFile());
+  setCompilerInstance(0);
+  return false;
+}
+
+void FrontendAction::Execute() {
+  CompilerInstance &CI = getCompilerInstance();
+
+  // Initialize the main file entry. This needs to be delayed until after PCH
+  // has loaded.
+  if (!isCurrentFileAST()) {
+    if (!CI.InitializeSourceManager(getCurrentFile(),
+                                    getCurrentInput().IsSystem
+                                      ? SrcMgr::C_System
+                                      : SrcMgr::C_User))
+      return;
+  }
+
+  if (CI.hasFrontendTimer()) {
+    llvm::TimeRegion Timer(CI.getFrontendTimer());
+    ExecuteAction();
+  }
+  else ExecuteAction();
+}
+
+void FrontendAction::EndSourceFile() {
+  CompilerInstance &CI = getCompilerInstance();
+
+  // Inform the diagnostic client we are done with this source file.
+  CI.getDiagnosticClient().EndSourceFile();
+
+  // Finalize the action.
+  EndSourceFileAction();
+
+  // Release the consumer and the AST, in that order since the consumer may
+  // perform actions in its destructor which require the context.
+  //
+  // FIXME: There is more per-file stuff we could just drop here?
+  if (CI.getFrontendOpts().DisableFree) {
+    CI.takeASTConsumer();
+    if (!isCurrentFileAST()) {
+      CI.takeSema();
+      CI.resetAndLeakASTContext();
+    }
+  } else {
+    if (!isCurrentFileAST()) {
+      CI.setSema(0);
+      CI.setASTContext(0);
+    }
+    CI.setASTConsumer(0);
+  }
+
+  // Inform the preprocessor we are done.
+  if (CI.hasPreprocessor())
+    CI.getPreprocessor().EndSourceFile();
+
+  if (CI.getFrontendOpts().ShowStats) {
+    llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFile() << "':\n";
+    CI.getPreprocessor().PrintStats();
+    CI.getPreprocessor().getIdentifierTable().PrintStats();
+    CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
+    CI.getSourceManager().PrintStats();
+    llvm::errs() << "\n";
+  }
+
+  // Cleanup the output streams, and erase the output files if we encountered
+  // an error.
+  CI.clearOutputFiles(/*EraseFiles=*/CI.getDiagnostics().hasErrorOccurred());
+
+  if (isCurrentFileAST()) {
+    CI.takeSema();
+    CI.resetAndLeakASTContext();
+    CI.resetAndLeakPreprocessor();
+    CI.resetAndLeakSourceManager();
+    CI.resetAndLeakFileManager();
+  }
+
+  setCompilerInstance(0);
+  setCurrentInput(FrontendInputFile());
+}
+
+//===----------------------------------------------------------------------===//
+// Utility Actions
+//===----------------------------------------------------------------------===//
+
+void ASTFrontendAction::ExecuteAction() {
+  CompilerInstance &CI = getCompilerInstance();
+
+  // FIXME: Move the truncation aspect of this into Sema, we delayed this till
+  // here so the source manager would be initialized.
+  if (hasCodeCompletionSupport() &&
+      !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
+    CI.createCodeCompletionConsumer();
+
+  // Use a code completion consumer?
+  CodeCompleteConsumer *CompletionConsumer = 0;
+  if (CI.hasCodeCompletionConsumer())
+    CompletionConsumer = &CI.getCodeCompletionConsumer();
+
+  if (!CI.hasSema())
+    CI.createSema(getTranslationUnitKind(), CompletionConsumer);
+
+  ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats,
+           CI.getFrontendOpts().SkipFunctionBodies);
+}
+
+void PluginASTAction::anchor() { }
+
+ASTConsumer *
+PreprocessorFrontendAction::CreateASTConsumer(CompilerInstance &CI,
+                                              StringRef InFile) {
+  llvm_unreachable("Invalid CreateASTConsumer on preprocessor action!");
+}
+
+ASTConsumer *WrapperFrontendAction::CreateASTConsumer(CompilerInstance &CI,
+                                                      StringRef InFile) {
+  return WrappedAction->CreateASTConsumer(CI, InFile);
+}
+bool WrapperFrontendAction::BeginInvocation(CompilerInstance &CI) {
+  return WrappedAction->BeginInvocation(CI);
+}
+bool WrapperFrontendAction::BeginSourceFileAction(CompilerInstance &CI,
+                                                  StringRef Filename) {
+  WrappedAction->setCurrentInput(getCurrentInput());
+  WrappedAction->setCompilerInstance(&CI);
+  return WrappedAction->BeginSourceFileAction(CI, Filename);
+}
+void WrapperFrontendAction::ExecuteAction() {
+  WrappedAction->ExecuteAction();
+}
+void WrapperFrontendAction::EndSourceFileAction() {
+  WrappedAction->EndSourceFileAction();
+}
+
+bool WrapperFrontendAction::usesPreprocessorOnly() const {
+  return WrappedAction->usesPreprocessorOnly();
+}
+TranslationUnitKind WrapperFrontendAction::getTranslationUnitKind() {
+  return WrappedAction->getTranslationUnitKind();
+}
+bool WrapperFrontendAction::hasPCHSupport() const {
+  return WrappedAction->hasPCHSupport();
+}
+bool WrapperFrontendAction::hasASTFileSupport() const {
+  return WrappedAction->hasASTFileSupport();
+}
+bool WrapperFrontendAction::hasIRSupport() const {
+  return WrappedAction->hasIRSupport();
+}
+bool WrapperFrontendAction::hasCodeCompletionSupport() const {
+  return WrappedAction->hasCodeCompletionSupport();
+}
+
+WrapperFrontendAction::WrapperFrontendAction(FrontendAction *WrappedAction)
+  : WrappedAction(WrappedAction) {}
+
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
new file mode 100644
index 0000000..737ee4a
--- /dev/null
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -0,0 +1,500 @@
+//===--- FrontendActions.cpp ----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Pragma.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Parse/Parser.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Frontend/ASTConsumers.h"
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Serialization/ASTWriter.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// Custom Actions
+//===----------------------------------------------------------------------===//
+
+ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
+                                               StringRef InFile) {
+  return new ASTConsumer();
+}
+
+void InitOnlyAction::ExecuteAction() {
+}
+
+//===----------------------------------------------------------------------===//
+// AST Consumer Actions
+//===----------------------------------------------------------------------===//
+
+ASTConsumer *ASTPrintAction::CreateASTConsumer(CompilerInstance &CI,
+                                               StringRef InFile) {
+  if (raw_ostream *OS = CI.createDefaultOutputFile(false, InFile))
+    return CreateASTPrinter(OS);
+  return 0;
+}
+
+ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
+                                              StringRef InFile) {
+  return CreateASTDumper();
+}
+
+ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
+                                                 StringRef InFile) {
+  raw_ostream *OS;
+  if (CI.getFrontendOpts().OutputFile.empty())
+    OS = &llvm::outs();
+  else
+    OS = CI.createDefaultOutputFile(false, InFile);
+  if (!OS) return 0;
+  return CreateASTDumperXML(*OS);
+}
+
+ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
+                                              StringRef InFile) {
+  return CreateASTViewer();
+}
+
+ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
+                                                       StringRef InFile) {
+  return CreateDeclContextPrinter();
+}
+
+ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
+                                                  StringRef InFile) {
+  std::string Sysroot;
+  std::string OutputFile;
+  raw_ostream *OS = 0;
+  if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
+    return 0;
+
+  if (!CI.getFrontendOpts().RelocatablePCH)
+    Sysroot.clear();
+  return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
+}
+
+bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
+                                                    StringRef InFile,
+                                                    std::string &Sysroot,
+                                                    std::string &OutputFile,
+                                                    raw_ostream *&OS) {
+  Sysroot = CI.getHeaderSearchOpts().Sysroot;
+  if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
+    CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
+    return true;
+  }
+
+  // We use createOutputFile here because this is exposed via libclang, and we
+  // must disable the RemoveFileOnSignal behavior.
+  // We use a temporary to avoid race conditions.
+  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
+                           /*RemoveFileOnSignal=*/false, InFile,
+                           /*Extension=*/"", /*useTemporary=*/true);
+  if (!OS)
+    return true;
+
+  OutputFile = CI.getFrontendOpts().OutputFile;
+  return false;
+}
+
+ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
+                                                     StringRef InFile) {
+  std::string Sysroot;
+  std::string OutputFile;
+  raw_ostream *OS = 0;
+  if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
+    return 0;
+  
+  return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module, 
+                          Sysroot, OS);
+}
+
+/// \brief Collect the set of header includes needed to construct the given 
+/// module.
+///
+/// \param Module The module we're collecting includes from.
+///
+/// \param Includes Will be augmented with the set of #includes or #imports
+/// needed to load all of the named headers.
+static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
+                                        FileManager &FileMgr,
+                                        ModuleMap &ModMap,
+                                        clang::Module *Module,
+                                        SmallString<256> &Includes) {
+  // Don't collect any headers for unavailable modules.
+  if (!Module->isAvailable())
+    return;
+
+  // Add includes for each of these headers.
+  for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
+    if (LangOpts.ObjC1)
+      Includes += "#import \"";
+    else
+      Includes += "#include \"";
+    Includes += Module->Headers[I]->getName();
+    Includes += "\"\n";
+  }
+
+  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
+    if (Module->Parent) {
+      // Include the umbrella header for submodules.
+      if (LangOpts.ObjC1)
+        Includes += "#import \"";
+      else
+        Includes += "#include \"";
+      Includes += UmbrellaHeader->getName();
+      Includes += "\"\n";
+    }
+  } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
+    // Add all of the headers we find in this subdirectory.
+    llvm::error_code EC;
+    SmallString<128> DirNative;
+    llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
+    for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC), 
+                                                     DirEnd;
+         Dir != DirEnd && !EC; Dir.increment(EC)) {
+      // Check whether this entry has an extension typically associated with 
+      // headers.
+      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
+          .Cases(".h", ".H", ".hh", ".hpp", true)
+          .Default(false))
+        continue;
+      
+      // If this header is marked 'unavailable' in this module, don't include 
+      // it.
+      if (const FileEntry *Header = FileMgr.getFile(Dir->path()))
+        if (ModMap.isHeaderInUnavailableModule(Header))
+          continue;
+      
+      // Include this header umbrella header for submodules.
+      if (LangOpts.ObjC1)
+        Includes += "#import \"";
+      else
+        Includes += "#include \"";
+      Includes += Dir->path();
+      Includes += "\"\n";
+    }
+  }
+  
+  // Recurse into submodules.
+  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
+                                      SubEnd = Module->submodule_end();
+       Sub != SubEnd; ++Sub)
+    collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
+}
+
+bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI, 
+                                                 StringRef Filename) {
+  // Find the module map file.  
+  const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
+  if (!ModuleMap)  {
+    CI.getDiagnostics().Report(diag::err_module_map_not_found)
+      << Filename;
+    return false;
+  }
+  
+  // Parse the module map file.
+  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
+  if (HS.loadModuleMapFile(ModuleMap))
+    return false;
+  
+  if (CI.getLangOpts().CurrentModule.empty()) {
+    CI.getDiagnostics().Report(diag::err_missing_module_name);
+    
+    // FIXME: Eventually, we could consider asking whether there was just
+    // a single module described in the module map, and use that as a 
+    // default. Then it would be fairly trivial to just "compile" a module
+    // map with a single module (the common case).
+    return false;
+  }
+  
+  // Dig out the module definition.
+  Module = HS.lookupModule(CI.getLangOpts().CurrentModule, 
+                           /*AllowSearch=*/false);
+  if (!Module) {
+    CI.getDiagnostics().Report(diag::err_missing_module)
+      << CI.getLangOpts().CurrentModule << Filename;
+    
+    return false;
+  }
+
+  // Check whether we can build this module at all.
+  StringRef Feature;
+  if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
+    CI.getDiagnostics().Report(diag::err_module_unavailable)
+      << Module->getFullModuleName()
+      << Feature;
+
+    return false;
+  }
+
+  // Do we have an umbrella header for this module?
+  const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
+  
+  // Collect the set of #includes we need to build the module.
+  SmallString<256> HeaderContents;
+  collectModuleHeaderIncludes(CI.getLangOpts(), CI.getFileManager(),
+    CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
+    Module, HeaderContents);
+  if (UmbrellaHeader && HeaderContents.empty()) {
+    // Simple case: we have an umbrella header and there are no additional
+    // includes, we can just parse the umbrella header directly.
+    setCurrentInput(FrontendInputFile(UmbrellaHeader->getName(),
+                                      getCurrentFileKind(),
+                                      Module->IsSystem));
+    return true;
+  }
+  
+  FileManager &FileMgr = CI.getFileManager();
+  SmallString<128> HeaderName;
+  time_t ModTime;
+  if (UmbrellaHeader) {
+    // Read in the umbrella header.
+    // FIXME: Go through the source manager; the umbrella header may have
+    // been overridden.
+    std::string ErrorStr;
+    llvm::MemoryBuffer *UmbrellaContents
+      = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
+    if (!UmbrellaContents) {
+      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
+        << UmbrellaHeader->getName() << ErrorStr;
+      return false;
+    }
+    
+    // Combine the contents of the umbrella header with the automatically-
+    // generated includes.
+    SmallString<256> OldContents = HeaderContents;
+    HeaderContents = UmbrellaContents->getBuffer();
+    HeaderContents += "\n\n";
+    HeaderContents += "/* Module includes */\n";
+    HeaderContents += OldContents;
+
+    // Pretend that we're parsing the umbrella header.
+    HeaderName = UmbrellaHeader->getName();
+    ModTime = UmbrellaHeader->getModificationTime();
+    
+    delete UmbrellaContents;
+  } else {
+    // Pick an innocuous-sounding name for the umbrella header.
+    HeaderName = Module->Name + ".h";
+    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false, 
+                        /*CacheFailure=*/false)) {
+      // Try again!
+      HeaderName = Module->Name + "-module.h";      
+      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false, 
+                          /*CacheFailure=*/false)) {
+        // Pick something ridiculous and go with it.
+        HeaderName = Module->Name + "-module.hmod";
+      }
+    }
+    ModTime = time(0);
+  }
+  
+  // Remap the contents of the header name we're using to our synthesized
+  // buffer.
+  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName, 
+                                                       HeaderContents.size(), 
+                                                       ModTime);
+  llvm::MemoryBuffer *HeaderContentsBuf
+    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
+  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);  
+  setCurrentInput(FrontendInputFile(HeaderName, getCurrentFileKind(),
+                                    Module->IsSystem));
+  return true;
+}
+
+bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
+                                                       StringRef InFile,
+                                                       std::string &Sysroot,
+                                                       std::string &OutputFile,
+                                                       raw_ostream *&OS) {
+  // If no output file was provided, figure out where this module would go
+  // in the module cache.
+  if (CI.getFrontendOpts().OutputFile.empty()) {
+    HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
+    SmallString<256> ModuleFileName(HS.getModuleCachePath());
+    llvm::sys::path::append(ModuleFileName, 
+                            CI.getLangOpts().CurrentModule + ".pcm");
+    CI.getFrontendOpts().OutputFile = ModuleFileName.str();
+  }
+  
+  // We use createOutputFile here because this is exposed via libclang, and we
+  // must disable the RemoveFileOnSignal behavior.
+  // We use a temporary to avoid race conditions.
+  OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
+                           /*RemoveFileOnSignal=*/false, InFile,
+                           /*Extension=*/"", /*useTemporary=*/true,
+                           /*CreateMissingDirectories=*/true);
+  if (!OS)
+    return true;
+  
+  OutputFile = CI.getFrontendOpts().OutputFile;
+  return false;
+}
+
+ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
+                                                 StringRef InFile) {
+  return new ASTConsumer();
+}
+
+//===----------------------------------------------------------------------===//
+// Preprocessor Actions
+//===----------------------------------------------------------------------===//
+
+void DumpRawTokensAction::ExecuteAction() {
+  Preprocessor &PP = getCompilerInstance().getPreprocessor();
+  SourceManager &SM = PP.getSourceManager();
+
+  // Start lexing the specified input file.
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
+  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
+  RawLex.SetKeepWhitespaceMode(true);
+
+  Token RawTok;
+  RawLex.LexFromRawLexer(RawTok);
+  while (RawTok.isNot(tok::eof)) {
+    PP.DumpToken(RawTok, true);
+    llvm::errs() << "\n";
+    RawLex.LexFromRawLexer(RawTok);
+  }
+}
+
+void DumpTokensAction::ExecuteAction() {
+  Preprocessor &PP = getCompilerInstance().getPreprocessor();
+  // Start preprocessing the specified input file.
+  Token Tok;
+  PP.EnterMainSourceFile();
+  do {
+    PP.Lex(Tok);
+    PP.DumpToken(Tok, true);
+    llvm::errs() << "\n";
+  } while (Tok.isNot(tok::eof));
+}
+
+void GeneratePTHAction::ExecuteAction() {
+  CompilerInstance &CI = getCompilerInstance();
+  if (CI.getFrontendOpts().OutputFile.empty() ||
+      CI.getFrontendOpts().OutputFile == "-") {
+    // FIXME: Don't fail this way.
+    // FIXME: Verify that we can actually seek in the given file.
+    llvm::report_fatal_error("PTH requires a seekable file for output!");
+  }
+  llvm::raw_fd_ostream *OS =
+    CI.createDefaultOutputFile(true, getCurrentFile());
+  if (!OS) return;
+
+  CacheTokens(CI.getPreprocessor(), OS);
+}
+
+void PreprocessOnlyAction::ExecuteAction() {
+  Preprocessor &PP = getCompilerInstance().getPreprocessor();
+
+  // Ignore unknown pragmas.
+  PP.AddPragmaHandler(new EmptyPragmaHandler());
+
+  Token Tok;
+  // Start parsing the specified input file.
+  PP.EnterMainSourceFile();
+  do {
+    PP.Lex(Tok);
+  } while (Tok.isNot(tok::eof));
+}
+
+void PrintPreprocessedAction::ExecuteAction() {
+  CompilerInstance &CI = getCompilerInstance();
+  // Output file may need to be set to 'Binary', to avoid converting Unix style
+  // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
+  //
+  // Look to see what type of line endings the file uses. If there's a
+  // CRLF, then we won't open the file up in binary mode. If there is
+  // just an LF or CR, then we will open the file up in binary mode.
+  // In this fashion, the output format should match the input format, unless
+  // the input format has inconsistent line endings.
+  //
+  // This should be a relatively fast operation since most files won't have
+  // all of their source code on a single line. However, that is still a 
+  // concern, so if we scan for too long, we'll just assume the file should
+  // be opened in binary mode.
+  bool BinaryMode = true;
+  bool InvalidFile = false;
+  const SourceManager& SM = CI.getSourceManager();
+  const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(), 
+                                                     &InvalidFile);
+  if (!InvalidFile) {
+    const char *cur = Buffer->getBufferStart();
+    const char *end = Buffer->getBufferEnd();
+    const char *next = (cur != end) ? cur + 1 : end;
+
+    // Limit ourselves to only scanning 256 characters into the source
+    // file.  This is mostly a sanity check in case the file has no 
+    // newlines whatsoever.
+    if (end - cur > 256) end = cur + 256;
+	  
+    while (next < end) {
+      if (*cur == 0x0D) {  // CR
+        if (*next == 0x0A)  // CRLF
+          BinaryMode = false;
+
+        break;
+      } else if (*cur == 0x0A)  // LF
+        break;
+
+      ++cur, ++next;
+    }
+  }
+
+  raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
+  if (!OS) return;
+
+  DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
+                           CI.getPreprocessorOutputOpts());
+}
+
+void PrintPreambleAction::ExecuteAction() {
+  switch (getCurrentFileKind()) {
+  case IK_C:
+  case IK_CXX:
+  case IK_ObjC:
+  case IK_ObjCXX:
+  case IK_OpenCL:
+  case IK_CUDA:
+    break;
+      
+  case IK_None:
+  case IK_Asm:
+  case IK_PreprocessedC:
+  case IK_PreprocessedCXX:
+  case IK_PreprocessedObjC:
+  case IK_PreprocessedObjCXX:
+  case IK_AST:
+  case IK_LLVM_IR:
+    // We can't do anything with these.
+    return;
+  }
+  
+  CompilerInstance &CI = getCompilerInstance();
+  llvm::MemoryBuffer *Buffer
+      = CI.getFileManager().getBufferForFile(getCurrentFile());
+  if (Buffer) {
+    unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
+    llvm::outs().write(Buffer->getBufferStart(), Preamble);
+    delete Buffer;
+  }
+}
diff --git a/clang/lib/Frontend/FrontendOptions.cpp b/clang/lib/Frontend/FrontendOptions.cpp
new file mode 100644
index 0000000..ea4005f
--- /dev/null
+++ b/clang/lib/Frontend/FrontendOptions.cpp
@@ -0,0 +1,32 @@
+//===--- FrontendOptions.cpp ----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/FrontendOptions.h"
+#include "llvm/ADT/StringSwitch.h"
+using namespace clang;
+
+InputKind FrontendOptions::getInputKindForExtension(StringRef Extension) {
+  return llvm::StringSwitch<InputKind>(Extension)
+    .Case("ast", IK_AST)
+    .Case("c", IK_C)
+    .Cases("S", "s", IK_Asm)
+    .Case("i", IK_PreprocessedC)
+    .Case("ii", IK_PreprocessedCXX)
+    .Case("m", IK_ObjC)
+    .Case("mi", IK_PreprocessedObjC)
+    .Cases("mm", "M", IK_ObjCXX)
+    .Case("mii", IK_PreprocessedObjCXX)
+    .Case("C", IK_CXX)
+    .Cases("C", "cc", "cp", IK_CXX)
+    .Cases("cpp", "CPP", "c++", "cxx", "hpp", IK_CXX)
+    .Case("cl", IK_OpenCL)
+    .Case("cu", IK_CUDA)
+    .Cases("ll", "bc", IK_LLVM_IR)
+    .Default(IK_C);
+}
diff --git a/clang/lib/Frontend/HeaderIncludeGen.cpp b/clang/lib/Frontend/HeaderIncludeGen.cpp
new file mode 100644
index 0000000..79920df
--- /dev/null
+++ b/clang/lib/Frontend/HeaderIncludeGen.cpp
@@ -0,0 +1,126 @@
+//===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace clang;
+
+namespace {
+class HeaderIncludesCallback : public PPCallbacks {
+  SourceManager &SM;
+  raw_ostream *OutputFile;
+  unsigned CurrentIncludeDepth;
+  bool HasProcessedPredefines;
+  bool OwnsOutputFile;
+  bool ShowAllHeaders;
+  bool ShowDepth;
+
+public:
+  HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
+                         raw_ostream *OutputFile_, bool OwnsOutputFile_,
+                         bool ShowDepth_)
+    : SM(PP->getSourceManager()), OutputFile(OutputFile_),
+      CurrentIncludeDepth(0), HasProcessedPredefines(false),
+      OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_),
+      ShowDepth(ShowDepth_) {}
+
+  ~HeaderIncludesCallback() {
+    if (OwnsOutputFile)
+      delete OutputFile;
+  }
+
+  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                           SrcMgr::CharacteristicKind FileType,
+                           FileID PrevFID);
+};
+}
+
+void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders,
+                                   StringRef OutputPath, bool ShowDepth) {
+  raw_ostream *OutputFile = &llvm::errs();
+  bool OwnsOutputFile = false;
+
+  // Open the output file, if used.
+  if (!OutputPath.empty()) {
+    std::string Error;
+    llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
+      OutputPath.str().c_str(), Error, llvm::raw_fd_ostream::F_Append);
+    if (!Error.empty()) {
+      PP.getDiagnostics().Report(
+        clang::diag::warn_fe_cc_print_header_failure) << Error;
+      delete OS;
+    } else {
+      OS->SetUnbuffered();
+      OS->SetUseAtomicWrites(true);
+      OutputFile = OS;
+      OwnsOutputFile = true;
+    }
+  }
+
+  PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders,
+                                               OutputFile, OwnsOutputFile,
+                                               ShowDepth));
+}
+
+void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
+                                         FileChangeReason Reason,
+                                       SrcMgr::CharacteristicKind NewFileType,
+                                       FileID PrevFID) {
+  // Unless we are exiting a #include, make sure to skip ahead to the line the
+  // #include directive was at.
+  PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
+  if (UserLoc.isInvalid())
+    return;
+
+  // Adjust the current include depth.
+  if (Reason == PPCallbacks::EnterFile) {
+    ++CurrentIncludeDepth;
+  } else if (Reason == PPCallbacks::ExitFile) {
+    if (CurrentIncludeDepth)
+      --CurrentIncludeDepth;
+
+    // We track when we are done with the predefines by watching for the first
+    // place where we drop back to a nesting depth of 1.
+    if (CurrentIncludeDepth == 1 && !HasProcessedPredefines)
+      HasProcessedPredefines = true;
+
+    return;
+  } else
+    return;
+
+  // Show the header if we are (a) past the predefines, or (b) showing all
+  // headers and in the predefines at a depth past the initial file and command
+  // line buffers.
+  bool ShowHeader = (HasProcessedPredefines ||
+                     (ShowAllHeaders && CurrentIncludeDepth > 2));
+
+  // Dump the header include information we are past the predefines buffer or
+  // are showing all headers.
+  if (ShowHeader && Reason == PPCallbacks::EnterFile) {
+    // Write to a temporary string to avoid unnecessary flushing on errs().
+    SmallString<512> Filename(UserLoc.getFilename());
+    Lexer::Stringify(Filename);
+
+    SmallString<256> Msg;
+    if (ShowDepth) {
+      // The main source file is at depth 1, so skip one dot.
+      for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
+        Msg += '.';
+      Msg += ' ';
+    }
+    Msg += Filename;
+    Msg += '\n';
+
+    OutputFile->write(Msg.data(), Msg.size());
+  }
+}
diff --git a/clang/lib/Frontend/InitHeaderSearch.cpp b/clang/lib/Frontend/InitHeaderSearch.cpp
new file mode 100644
index 0000000..3f7e682
--- /dev/null
+++ b/clang/lib/Frontend/InitHeaderSearch.cpp
@@ -0,0 +1,672 @@
+//===--- InitHeaderSearch.cpp - Initialize header search paths ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the InitHeaderSearch class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Frontend/HeaderSearchOptions.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Path.h"
+
+#include "clang/Config/config.h" // C_INCLUDE_DIRS
+
+using namespace clang;
+using namespace clang::frontend;
+
+namespace {
+
+/// InitHeaderSearch - This class makes it easier to set the search paths of
+///  a HeaderSearch object. InitHeaderSearch stores several search path lists
+///  internally, which can be sent to a HeaderSearch object in one swoop.
+class InitHeaderSearch {
+  std::vector<std::pair<IncludeDirGroup, DirectoryLookup> > IncludePath;
+  typedef std::vector<std::pair<IncludeDirGroup,
+                      DirectoryLookup> >::const_iterator path_iterator;
+  HeaderSearch &Headers;
+  bool Verbose;
+  std::string IncludeSysroot;
+  bool IsNotEmptyOrRoot;
+
+public:
+
+  InitHeaderSearch(HeaderSearch &HS, bool verbose, StringRef sysroot)
+    : Headers(HS), Verbose(verbose), IncludeSysroot(sysroot),
+      IsNotEmptyOrRoot(!(sysroot.empty() || sysroot == "/")) {
+  }
+
+  /// AddPath - Add the specified path to the specified group list.
+  void AddPath(const Twine &Path, IncludeDirGroup Group,
+               bool isCXXAware, bool isUserSupplied,
+               bool isFramework, bool IgnoreSysRoot = false);
+
+  /// AddGnuCPlusPlusIncludePaths - Add the necessary paths to support a gnu
+  ///  libstdc++.
+  void AddGnuCPlusPlusIncludePaths(StringRef Base,
+                                   StringRef ArchDir,
+                                   StringRef Dir32,
+                                   StringRef Dir64,
+                                   const llvm::Triple &triple);
+
+  /// AddMinGWCPlusPlusIncludePaths - Add the necessary paths to support a MinGW
+  ///  libstdc++.
+  void AddMinGWCPlusPlusIncludePaths(StringRef Base,
+                                     StringRef Arch,
+                                     StringRef Version);
+
+  /// AddMinGW64CXXPaths - Add the necessary paths to support
+  /// libstdc++ of x86_64-w64-mingw32 aka mingw-w64.
+  void AddMinGW64CXXPaths(StringRef Base,
+                          StringRef Version);
+
+  // AddDefaultCIncludePaths - Add paths that should always be searched.
+  void AddDefaultCIncludePaths(const llvm::Triple &triple,
+                               const HeaderSearchOptions &HSOpts);
+
+  // AddDefaultCPlusPlusIncludePaths -  Add paths that should be searched when
+  //  compiling c++.
+  void AddDefaultCPlusPlusIncludePaths(const llvm::Triple &triple,
+                                       const HeaderSearchOptions &HSOpts);
+
+  /// AddDefaultSystemIncludePaths - Adds the default system include paths so
+  ///  that e.g. stdio.h is found.
+  void AddDefaultIncludePaths(const LangOptions &Lang,
+                              const llvm::Triple &triple,
+                              const HeaderSearchOptions &HSOpts);
+
+  /// Realize - Merges all search path lists into one list and send it to
+  /// HeaderSearch.
+  void Realize(const LangOptions &Lang);
+};
+
+}  // end anonymous namespace.
+
+void InitHeaderSearch::AddPath(const Twine &Path,
+                               IncludeDirGroup Group, bool isCXXAware,
+                               bool isUserSupplied, bool isFramework,
+                               bool IgnoreSysRoot) {
+  assert(!Path.isTriviallyEmpty() && "can't handle empty path here");
+  FileManager &FM = Headers.getFileMgr();
+
+  // Compute the actual path, taking into consideration -isysroot.
+  SmallString<256> MappedPathStorage;
+  StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
+
+  // Handle isysroot.
+  if ((Group == System || Group == CXXSystem) && !IgnoreSysRoot &&
+#if defined(_WIN32)
+      !MappedPathStr.empty() &&
+      llvm::sys::path::is_separator(MappedPathStr[0]) &&
+#else
+      llvm::sys::path::is_absolute(MappedPathStr) &&
+#endif
+      IsNotEmptyOrRoot) {
+    MappedPathStorage.clear();
+    MappedPathStr =
+      (IncludeSysroot + Path).toStringRef(MappedPathStorage);
+  }
+
+  // Compute the DirectoryLookup type.
+  SrcMgr::CharacteristicKind Type;
+  if (Group == Quoted || Group == Angled || Group == IndexHeaderMap)
+    Type = SrcMgr::C_User;
+  else if (isCXXAware)
+    Type = SrcMgr::C_System;
+  else
+    Type = SrcMgr::C_ExternCSystem;
+
+
+  // If the directory exists, add it.
+  if (const DirectoryEntry *DE = FM.getDirectory(MappedPathStr)) {
+    IncludePath.push_back(std::make_pair(Group, DirectoryLookup(DE, Type,
+                          isUserSupplied, isFramework)));
+    return;
+  }
+
+  // Check to see if this is an apple-style headermap (which are not allowed to
+  // be frameworks).
+  if (!isFramework) {
+    if (const FileEntry *FE = FM.getFile(MappedPathStr)) {
+      if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
+        // It is a headermap, add it to the search path.
+        IncludePath.push_back(std::make_pair(Group, DirectoryLookup(HM, Type,
+                              isUserSupplied, Group == IndexHeaderMap)));
+        return;
+      }
+    }
+  }
+
+  if (Verbose)
+    llvm::errs() << "ignoring nonexistent directory \""
+                 << MappedPathStr << "\"\n";
+}
+
+void InitHeaderSearch::AddGnuCPlusPlusIncludePaths(StringRef Base,
+                                                   StringRef ArchDir,
+                                                   StringRef Dir32,
+                                                   StringRef Dir64,
+                                                   const llvm::Triple &triple) {
+  // Add the base dir
+  AddPath(Base, CXXSystem, true, false, false);
+
+  // Add the multilib dirs
+  llvm::Triple::ArchType arch = triple.getArch();
+  bool is64bit = arch == llvm::Triple::ppc64 || arch == llvm::Triple::x86_64;
+  if (is64bit)
+    AddPath(Base + "/" + ArchDir + "/" + Dir64, CXXSystem, true, false, false);
+  else
+    AddPath(Base + "/" + ArchDir + "/" + Dir32, CXXSystem, true, false, false);
+
+  // Add the backward dir
+  AddPath(Base + "/backward", CXXSystem, true, false, false);
+}
+
+void InitHeaderSearch::AddMinGWCPlusPlusIncludePaths(StringRef Base,
+                                                     StringRef Arch,
+                                                     StringRef Version) {
+  AddPath(Base + "/" + Arch + "/" + Version + "/include/c++",
+          CXXSystem, true, false, false);
+  AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/" + Arch,
+          CXXSystem, true, false, false);
+  AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/backward",
+          CXXSystem, true, false, false);
+}
+
+void InitHeaderSearch::AddMinGW64CXXPaths(StringRef Base,
+                                          StringRef Version) {
+  // Assumes Base is HeaderSearchOpts' ResourceDir
+  AddPath(Base + "/../../../include/c++/" + Version,
+          CXXSystem, true, false, false);
+  AddPath(Base + "/../../../include/c++/" + Version + "/x86_64-w64-mingw32",
+          CXXSystem, true, false, false);
+  AddPath(Base + "/../../../include/c++/" + Version + "/i686-w64-mingw32",
+          CXXSystem, true, false, false);
+  AddPath(Base + "/../../../include/c++/" + Version + "/backward",
+          CXXSystem, true, false, false);
+}
+
+void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
+                                            const HeaderSearchOptions &HSOpts) {
+  llvm::Triple::OSType os = triple.getOS();
+
+  if (HSOpts.UseStandardSystemIncludes) {
+    switch (os) {
+    case llvm::Triple::FreeBSD:
+    case llvm::Triple::NetBSD:
+      break;
+    default:
+      // FIXME: temporary hack: hard-coded paths.
+      AddPath("/usr/local/include", System, true, false, false);
+      break;
+    }
+  }
+
+  // Builtin includes use #include_next directives and should be positioned
+  // just prior C include dirs.
+  if (HSOpts.UseBuiltinIncludes) {
+    // Ignore the sys root, we *always* look for clang headers relative to
+    // supplied path.
+    llvm::sys::Path P(HSOpts.ResourceDir);
+    P.appendComponent("include");
+    AddPath(P.str(), System, false, false, false, /*IgnoreSysRoot=*/ true);
+  }
+
+  // All remaining additions are for system include directories, early exit if
+  // we aren't using them.
+  if (!HSOpts.UseStandardSystemIncludes)
+    return;
+
+  // Add dirs specified via 'configure --with-c-include-dirs'.
+  StringRef CIncludeDirs(C_INCLUDE_DIRS);
+  if (CIncludeDirs != "") {
+    SmallVector<StringRef, 5> dirs;
+    CIncludeDirs.split(dirs, ":");
+    for (SmallVectorImpl<StringRef>::iterator i = dirs.begin();
+         i != dirs.end();
+         ++i)
+      AddPath(*i, System, false, false, false);
+    return;
+  }
+
+  switch (os) {
+  case llvm::Triple::Linux:
+  case llvm::Triple::Win32:
+    llvm_unreachable("Include management is handled in the driver.");
+
+  case llvm::Triple::Haiku:
+    AddPath("/boot/common/include", System, true, false, false);
+    AddPath("/boot/develop/headers/os", System, true, false, false);
+    AddPath("/boot/develop/headers/os/app", System, true, false, false);
+    AddPath("/boot/develop/headers/os/arch", System, true, false, false);
+    AddPath("/boot/develop/headers/os/device", System, true, false, false);
+    AddPath("/boot/develop/headers/os/drivers", System, true, false, false);
+    AddPath("/boot/develop/headers/os/game", System, true, false, false);
+    AddPath("/boot/develop/headers/os/interface", System, true, false, false);
+    AddPath("/boot/develop/headers/os/kernel", System, true, false, false);
+    AddPath("/boot/develop/headers/os/locale", System, true, false, false);
+    AddPath("/boot/develop/headers/os/mail", System, true, false, false);
+    AddPath("/boot/develop/headers/os/media", System, true, false, false);
+    AddPath("/boot/develop/headers/os/midi", System, true, false, false);
+    AddPath("/boot/develop/headers/os/midi2", System, true, false, false);
+    AddPath("/boot/develop/headers/os/net", System, true, false, false);
+    AddPath("/boot/develop/headers/os/storage", System, true, false, false);
+    AddPath("/boot/develop/headers/os/support", System, true, false, false);
+    AddPath("/boot/develop/headers/os/translation",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/add-ons/graphics",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/add-ons/input_server",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/add-ons/screen_saver",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/add-ons/tracker",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/be_apps/Deskbar",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/be_apps/NetPositive",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/os/be_apps/Tracker",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/cpp", System, true, false, false);
+    AddPath("/boot/develop/headers/cpp/i586-pc-haiku",
+      System, true, false, false);
+    AddPath("/boot/develop/headers/3rdparty", System, true, false, false);
+    AddPath("/boot/develop/headers/bsd", System, true, false, false);
+    AddPath("/boot/develop/headers/glibc", System, true, false, false);
+    AddPath("/boot/develop/headers/posix", System, true, false, false);
+    AddPath("/boot/develop/headers",  System, true, false, false);
+    break;
+  case llvm::Triple::RTEMS:
+    break;
+  case llvm::Triple::Cygwin:
+    AddPath("/usr/include/w32api", System, true, false, false);
+    break;
+  case llvm::Triple::MinGW32: { 
+      // mingw-w64 crt include paths
+      llvm::sys::Path P(HSOpts.ResourceDir);
+      P.appendComponent("../../../i686-w64-mingw32/include"); // <sysroot>/i686-w64-mingw32/include
+      AddPath(P.str(), System, true, false, false);
+      P = llvm::sys::Path(HSOpts.ResourceDir);
+      P.appendComponent("../../../x86_64-w64-mingw32/include"); // <sysroot>/x86_64-w64-mingw32/include
+      AddPath(P.str(), System, true, false, false);
+      // mingw.org crt include paths
+      P = llvm::sys::Path(HSOpts.ResourceDir);
+      P.appendComponent("../../../include"); // <sysroot>/include
+      AddPath(P.str(), System, true, false, false);
+      AddPath("/mingw/include", System, true, false, false);
+      AddPath("c:/mingw/include", System, true, false, false); 
+    }
+    break;
+      
+  default:
+    break;
+  }
+
+  if ( os != llvm::Triple::RTEMS )
+    AddPath("/usr/include", System, false, false, false);
+}
+
+void InitHeaderSearch::
+AddDefaultCPlusPlusIncludePaths(const llvm::Triple &triple, const HeaderSearchOptions &HSOpts) {
+  llvm::Triple::OSType os = triple.getOS();
+  // FIXME: temporary hack: hard-coded paths.
+
+  if (triple.isOSDarwin()) {
+    switch (triple.getArch()) {
+    default: break;
+
+    case llvm::Triple::ppc:
+    case llvm::Triple::ppc64:
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
+                                  "powerpc-apple-darwin10", "", "ppc64",
+                                  triple);
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
+                                  "powerpc-apple-darwin10", "", "ppc64",
+                                  triple);
+      break;
+
+    case llvm::Triple::x86:
+    case llvm::Triple::x86_64:
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
+                                  "i686-apple-darwin10", "", "x86_64", triple);
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
+                                  "i686-apple-darwin8", "", "", triple);
+      break;
+
+    case llvm::Triple::arm:
+    case llvm::Triple::thumb:
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
+                                  "arm-apple-darwin10", "v7", "", triple);
+      AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
+                                  "arm-apple-darwin10", "v6", "", triple);
+      break;
+    }
+    return;
+  }
+
+  switch (os) {
+  case llvm::Triple::Linux:
+  case llvm::Triple::Win32:
+    llvm_unreachable("Include management is handled in the driver.");
+
+  case llvm::Triple::Cygwin:
+    // Cygwin-1.7
+    AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.5.3");
+    AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.4");
+    // g++-4 / Cygwin-1.5
+    AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
+    break;
+  case llvm::Triple::MinGW32:
+    // mingw-w64 C++ include paths (i686-w64-mingw32 and x86_64-w64-mingw32)
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.0");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.1");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.2");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.3");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.4");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.0");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.1");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.2");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.3");
+    AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.7.0");
+    // mingw.org C++ include paths
+    AddMinGWCPlusPlusIncludePaths("/mingw/lib/gcc", "mingw32", "4.5.2"); //MSYS
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.2");
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.1");
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.2");
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.0");
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.4.0");
+    AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.3.0");
+    break;
+  case llvm::Triple::DragonFly:
+    AddPath("/usr/include/c++/4.1", CXXSystem, true, false, false);
+    break;
+  case llvm::Triple::FreeBSD:
+    // FreeBSD 8.0
+    // FreeBSD 7.3
+    AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2", "", "", "", triple);
+    break;
+  case llvm::Triple::NetBSD:
+    AddGnuCPlusPlusIncludePaths("/usr/include/g++", "", "", "", triple);
+    break;
+  case llvm::Triple::OpenBSD: {
+    std::string t = triple.getTriple();
+    if (t.substr(0, 6) == "x86_64")
+      t.replace(0, 6, "amd64");
+    AddGnuCPlusPlusIncludePaths("/usr/include/g++",
+                                t, "", "", triple);
+    break;
+  }
+  case llvm::Triple::Minix:
+    AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
+                                "", "", "", triple);
+    break;
+  case llvm::Triple::Solaris:
+    AddGnuCPlusPlusIncludePaths("/usr/gcc/4.5/include/c++/4.5.2/",
+                                "i386-pc-solaris2.11", "", "", triple);
+    // Solaris - Fall though..
+  case llvm::Triple::AuroraUX:
+    // AuroraUX
+    AddGnuCPlusPlusIncludePaths("/opt/gcc4/include/c++/4.2.4",
+                                "i386-pc-solaris2.11", "", "", triple);
+    break;
+  default:
+    break;
+  }
+}
+
+void InitHeaderSearch::AddDefaultIncludePaths(const LangOptions &Lang,
+                                              const llvm::Triple &triple,
+                                            const HeaderSearchOptions &HSOpts) {
+  // NB: This code path is going away. All of the logic is moving into the
+  // driver which has the information necessary to do target-specific
+  // selections of default include paths. Each target which moves there will be
+  // exempted from this logic here until we can delete the entire pile of code.
+  switch (triple.getOS()) {
+  default:
+    break; // Everything else continues to use this routine's logic.
+
+  case llvm::Triple::Linux:
+  case llvm::Triple::Win32:
+    return;
+  }
+
+  if (Lang.CPlusPlus && HSOpts.UseStandardCXXIncludes &&
+      HSOpts.UseStandardSystemIncludes) {
+    if (HSOpts.UseLibcxx) {
+      if (triple.isOSDarwin()) {
+        // On Darwin, libc++ may be installed alongside the compiler in
+        // lib/c++/v1.
+        llvm::sys::Path P(HSOpts.ResourceDir);
+        if (!P.isEmpty()) {
+          P.eraseComponent();  // Remove version from foo/lib/clang/version
+          P.eraseComponent();  // Remove clang from foo/lib/clang
+          
+          // Get foo/lib/c++/v1
+          P.appendComponent("c++");
+          P.appendComponent("v1");
+          AddPath(P.str(), CXXSystem, true, false, false, true);
+        }
+      }
+      // On Solaris, include the support directory for things like xlocale and
+      // fudged system headers.
+      if (triple.getOS() == llvm::Triple::Solaris) 
+        AddPath("/usr/include/c++/v1/support/solaris", CXXSystem, true, false,
+            false);
+      
+      AddPath("/usr/include/c++/v1", CXXSystem, true, false, false);
+    } else {
+      AddDefaultCPlusPlusIncludePaths(triple, HSOpts);
+    }
+  }
+
+  AddDefaultCIncludePaths(triple, HSOpts);
+
+  // Add the default framework include paths on Darwin.
+  if (HSOpts.UseStandardSystemIncludes) {
+    if (triple.isOSDarwin()) {
+      AddPath("/System/Library/Frameworks", System, true, false, true);
+      AddPath("/Library/Frameworks", System, true, false, true);
+    }
+  }
+}
+
+/// RemoveDuplicates - If there are duplicate directory entries in the specified
+/// search list, remove the later (dead) ones.  Returns the number of non-system
+/// headers removed, which is used to update NumAngled.
+static unsigned RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
+                                 unsigned First, bool Verbose) {
+  llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
+  llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
+  llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
+  unsigned NonSystemRemoved = 0;
+  for (unsigned i = First; i != SearchList.size(); ++i) {
+    unsigned DirToRemove = i;
+
+    const DirectoryLookup &CurEntry = SearchList[i];
+
+    if (CurEntry.isNormalDir()) {
+      // If this isn't the first time we've seen this dir, remove it.
+      if (SeenDirs.insert(CurEntry.getDir()))
+        continue;
+    } else if (CurEntry.isFramework()) {
+      // If this isn't the first time we've seen this framework dir, remove it.
+      if (SeenFrameworkDirs.insert(CurEntry.getFrameworkDir()))
+        continue;
+    } else {
+      assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
+      // If this isn't the first time we've seen this headermap, remove it.
+      if (SeenHeaderMaps.insert(CurEntry.getHeaderMap()))
+        continue;
+    }
+
+    // If we have a normal #include dir/framework/headermap that is shadowed
+    // later in the chain by a system include location, we actually want to
+    // ignore the user's request and drop the user dir... keeping the system
+    // dir.  This is weird, but required to emulate GCC's search path correctly.
+    //
+    // Since dupes of system dirs are rare, just rescan to find the original
+    // that we're nuking instead of using a DenseMap.
+    if (CurEntry.getDirCharacteristic() != SrcMgr::C_User) {
+      // Find the dir that this is the same of.
+      unsigned FirstDir;
+      for (FirstDir = 0; ; ++FirstDir) {
+        assert(FirstDir != i && "Didn't find dupe?");
+
+        const DirectoryLookup &SearchEntry = SearchList[FirstDir];
+
+        // If these are different lookup types, then they can't be the dupe.
+        if (SearchEntry.getLookupType() != CurEntry.getLookupType())
+          continue;
+
+        bool isSame;
+        if (CurEntry.isNormalDir())
+          isSame = SearchEntry.getDir() == CurEntry.getDir();
+        else if (CurEntry.isFramework())
+          isSame = SearchEntry.getFrameworkDir() == CurEntry.getFrameworkDir();
+        else {
+          assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
+          isSame = SearchEntry.getHeaderMap() == CurEntry.getHeaderMap();
+        }
+
+        if (isSame)
+          break;
+      }
+
+      // If the first dir in the search path is a non-system dir, zap it
+      // instead of the system one.
+      if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
+        DirToRemove = FirstDir;
+    }
+
+    if (Verbose) {
+      llvm::errs() << "ignoring duplicate directory \""
+                   << CurEntry.getName() << "\"\n";
+      if (DirToRemove != i)
+        llvm::errs() << "  as it is a non-system directory that duplicates "
+                     << "a system directory\n";
+    }
+    if (DirToRemove != i)
+      ++NonSystemRemoved;
+
+    // This is reached if the current entry is a duplicate.  Remove the
+    // DirToRemove (usually the current dir).
+    SearchList.erase(SearchList.begin()+DirToRemove);
+    --i;
+  }
+  return NonSystemRemoved;
+}
+
+
+void InitHeaderSearch::Realize(const LangOptions &Lang) {
+  // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
+  std::vector<DirectoryLookup> SearchList;
+  SearchList.reserve(IncludePath.size());
+
+  // Quoted arguments go first.
+  for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
+       it != ie; ++it) {
+    if (it->first == Quoted)
+      SearchList.push_back(it->second);
+  }
+  // Deduplicate and remember index.
+  RemoveDuplicates(SearchList, 0, Verbose);
+  unsigned NumQuoted = SearchList.size();
+
+  for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
+       it != ie; ++it) {
+    if (it->first == Angled || it->first == IndexHeaderMap)
+      SearchList.push_back(it->second);
+  }
+
+  RemoveDuplicates(SearchList, NumQuoted, Verbose);
+  unsigned NumAngled = SearchList.size();
+
+  for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
+       it != ie; ++it) {
+    if (it->first == System ||
+        (!Lang.ObjC1 && !Lang.CPlusPlus && it->first == CSystem)    ||
+        (/*FIXME !Lang.ObjC1 && */Lang.CPlusPlus  && it->first == CXXSystem)  ||
+        (Lang.ObjC1  && !Lang.CPlusPlus && it->first == ObjCSystem) ||
+        (Lang.ObjC1  && Lang.CPlusPlus  && it->first == ObjCXXSystem))
+      SearchList.push_back(it->second);
+  }
+
+  for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
+       it != ie; ++it) {
+    if (it->first == After)
+      SearchList.push_back(it->second);
+  }
+
+  // Remove duplicates across both the Angled and System directories.  GCC does
+  // this and failing to remove duplicates across these two groups breaks
+  // #include_next.
+  unsigned NonSystemRemoved = RemoveDuplicates(SearchList, NumQuoted, Verbose);
+  NumAngled -= NonSystemRemoved;
+
+  bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
+  Headers.SetSearchPaths(SearchList, NumQuoted, NumAngled, DontSearchCurDir);
+
+  // If verbose, print the list of directories that will be searched.
+  if (Verbose) {
+    llvm::errs() << "#include \"...\" search starts here:\n";
+    for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
+      if (i == NumQuoted)
+        llvm::errs() << "#include <...> search starts here:\n";
+      const char *Name = SearchList[i].getName();
+      const char *Suffix;
+      if (SearchList[i].isNormalDir())
+        Suffix = "";
+      else if (SearchList[i].isFramework())
+        Suffix = " (framework directory)";
+      else {
+        assert(SearchList[i].isHeaderMap() && "Unknown DirectoryLookup");
+        Suffix = " (headermap)";
+      }
+      llvm::errs() << " " << Name << Suffix << "\n";
+    }
+    llvm::errs() << "End of search list.\n";
+  }
+}
+
+void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
+                                     const HeaderSearchOptions &HSOpts,
+                                     const LangOptions &Lang,
+                                     const llvm::Triple &Triple) {
+  InitHeaderSearch Init(HS, HSOpts.Verbose, HSOpts.Sysroot);
+
+  // Add the user defined entries.
+  for (unsigned i = 0, e = HSOpts.UserEntries.size(); i != e; ++i) {
+    const HeaderSearchOptions::Entry &E = HSOpts.UserEntries[i];
+    Init.AddPath(E.Path, E.Group, !E.ImplicitExternC, E.IsUserSupplied,
+                 E.IsFramework, E.IgnoreSysRoot);
+  }
+
+  Init.AddDefaultIncludePaths(Lang, Triple, HSOpts);
+
+  if (HSOpts.UseBuiltinIncludes) {
+    // Set up the builtin include directory in the module map.
+    llvm::sys::Path P(HSOpts.ResourceDir);
+    P.appendComponent("include");
+    if (const DirectoryEntry *Dir = HS.getFileMgr().getDirectory(P.str()))
+      HS.getModuleMap().setBuiltinIncludeDir(Dir);
+  }
+
+  Init.Realize(Lang);
+}
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
new file mode 100644
index 0000000..93d49b0
--- /dev/null
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -0,0 +1,763 @@
+//===--- InitPreprocessor.cpp - PP initialization code. ---------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the clang::InitializePreprocessor function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/Version.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/MacroBuilder.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "clang/Frontend/PreprocessorOptions.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/APFloat.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+using namespace clang;
+
+// Append a #define line to Buf for Macro.  Macro should be of the form XXX,
+// in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
+// "#define XXX Y z W".  To get a #define with no value, use "XXX=".
+static void DefineBuiltinMacro(MacroBuilder &Builder, StringRef Macro,
+                               DiagnosticsEngine &Diags) {
+  std::pair<StringRef, StringRef> MacroPair = Macro.split('=');
+  StringRef MacroName = MacroPair.first;
+  StringRef MacroBody = MacroPair.second;
+  if (MacroName.size() != Macro.size()) {
+    // Per GCC -D semantics, the macro ends at \n if it exists.
+    StringRef::size_type End = MacroBody.find_first_of("\n\r");
+    if (End != StringRef::npos)
+      Diags.Report(diag::warn_fe_macro_contains_embedded_newline)
+        << MacroName;
+    Builder.defineMacro(MacroName, MacroBody.substr(0, End));
+  } else {
+    // Push "macroname 1".
+    Builder.defineMacro(Macro);
+  }
+}
+
+/// AddImplicitInclude - Add an implicit #include of the specified file to the
+/// predefines buffer.
+static void AddImplicitInclude(MacroBuilder &Builder, StringRef File,
+                               FileManager &FileMgr) {
+  Builder.append(Twine("#include \"") +
+                 HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
+}
+
+static void AddImplicitIncludeMacros(MacroBuilder &Builder,
+                                     StringRef File,
+                                     FileManager &FileMgr) {
+  Builder.append(Twine("#__include_macros \"") +
+                 HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
+  // Marker token to stop the __include_macros fetch loop.
+  Builder.append("##"); // ##?
+}
+
+/// AddImplicitIncludePTH - Add an implicit #include using the original file
+///  used to generate a PTH cache.
+static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
+                                  StringRef ImplicitIncludePTH) {
+  PTHManager *P = PP.getPTHManager();
+  // Null check 'P' in the corner case where it couldn't be created.
+  const char *OriginalFile = P ? P->getOriginalSourceFile() : 0;
+
+  if (!OriginalFile) {
+    PP.getDiagnostics().Report(diag::err_fe_pth_file_has_no_source_header)
+      << ImplicitIncludePTH;
+    return;
+  }
+
+  AddImplicitInclude(Builder, OriginalFile, PP.getFileManager());
+}
+
+/// PickFP - This is used to pick a value based on the FP semantics of the
+/// specified FP model.
+template <typename T>
+static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
+                T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
+                T IEEEQuadVal) {
+  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
+    return IEEESingleVal;
+  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
+    return IEEEDoubleVal;
+  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
+    return X87DoubleExtendedVal;
+  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
+    return PPCDoubleDoubleVal;
+  assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
+  return IEEEQuadVal;
+}
+
+static void DefineFloatMacros(MacroBuilder &Builder, StringRef Prefix,
+                              const llvm::fltSemantics *Sem) {
+  const char *DenormMin, *Epsilon, *Max, *Min;
+  DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
+                     "3.64519953188247460253e-4951L",
+                     "4.94065645841246544176568792868221e-324L",
+                     "6.47517511943802511092443895822764655e-4966L");
+  int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
+  Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
+                   "1.08420217248550443401e-19L",
+                   "4.94065645841246544176568792868221e-324L",
+                   "1.92592994438723585305597794258492732e-34L");
+  int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
+  int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
+  int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
+  int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
+  int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
+  Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
+               "3.36210314311209350626e-4932L",
+               "2.00416836000897277799610805135016e-292L",
+               "3.36210314311209350626267781732175260e-4932L");
+  Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
+               "1.18973149535723176502e+4932L",
+               "1.79769313486231580793728971405301e+308L",
+               "1.18973149535723176508575932662800702e+4932L");
+
+  SmallString<32> DefPrefix;
+  DefPrefix = "__";
+  DefPrefix += Prefix;
+  DefPrefix += "_";
+
+  Builder.defineMacro(DefPrefix + "DENORM_MIN__", DenormMin);
+  Builder.defineMacro(DefPrefix + "HAS_DENORM__");
+  Builder.defineMacro(DefPrefix + "DIG__", Twine(Digits));
+  Builder.defineMacro(DefPrefix + "EPSILON__", Twine(Epsilon));
+  Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
+  Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
+  Builder.defineMacro(DefPrefix + "MANT_DIG__", Twine(MantissaDigits));
+
+  Builder.defineMacro(DefPrefix + "MAX_10_EXP__", Twine(Max10Exp));
+  Builder.defineMacro(DefPrefix + "MAX_EXP__", Twine(MaxExp));
+  Builder.defineMacro(DefPrefix + "MAX__", Twine(Max));
+
+  Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+Twine(Min10Exp)+")");
+  Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+Twine(MinExp)+")");
+  Builder.defineMacro(DefPrefix + "MIN__", Twine(Min));
+}
+
+
+/// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
+/// named MacroName with the max value for a type with width 'TypeWidth' a
+/// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
+static void DefineTypeSize(StringRef MacroName, unsigned TypeWidth,
+                           StringRef ValSuffix, bool isSigned,
+                           MacroBuilder &Builder) {
+  llvm::APInt MaxVal = isSigned ? llvm::APInt::getSignedMaxValue(TypeWidth)
+                                : llvm::APInt::getMaxValue(TypeWidth);
+  Builder.defineMacro(MacroName, MaxVal.toString(10, isSigned) + ValSuffix);
+}
+
+/// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
+/// the width, suffix, and signedness of the given type
+static void DefineTypeSize(StringRef MacroName, TargetInfo::IntType Ty,
+                           const TargetInfo &TI, MacroBuilder &Builder) {
+  DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty), 
+                 TI.isTypeSigned(Ty), Builder);
+}
+
+static void DefineType(const Twine &MacroName, TargetInfo::IntType Ty,
+                       MacroBuilder &Builder) {
+  Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
+}
+
+static void DefineTypeWidth(StringRef MacroName, TargetInfo::IntType Ty,
+                            const TargetInfo &TI, MacroBuilder &Builder) {
+  Builder.defineMacro(MacroName, Twine(TI.getTypeWidth(Ty)));
+}
+
+static void DefineTypeSizeof(StringRef MacroName, unsigned BitWidth,
+                             const TargetInfo &TI, MacroBuilder &Builder) {
+  Builder.defineMacro(MacroName,
+                      Twine(BitWidth / TI.getCharWidth()));
+}
+
+static void DefineExactWidthIntType(TargetInfo::IntType Ty, 
+                               const TargetInfo &TI, MacroBuilder &Builder) {
+  int TypeWidth = TI.getTypeWidth(Ty);
+
+  // Use the target specified int64 type, when appropriate, so that [u]int64_t
+  // ends up being defined in terms of the correct type.
+  if (TypeWidth == 64)
+    Ty = TI.getInt64Type();
+
+  DefineType("__INT" + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
+
+  StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
+  if (!ConstSuffix.empty())
+    Builder.defineMacro("__INT" + Twine(TypeWidth) + "_C_SUFFIX__",
+                        ConstSuffix);
+}
+
+/// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
+/// the specified properties.
+static const char *getLockFreeValue(unsigned TypeWidth, unsigned TypeAlign,
+                                    unsigned InlineWidth) {
+  // Fully-aligned, power-of-2 sizes no larger than the inline
+  // width will be inlined as lock-free operations.
+  if (TypeWidth == TypeAlign && (TypeWidth & (TypeWidth - 1)) == 0 &&
+      TypeWidth <= InlineWidth)
+    return "2"; // "always lock free"
+  // We cannot be certain what operations the lib calls might be
+  // able to implement as lock-free on future processors.
+  return "1"; // "sometimes lock free"
+}
+
+/// \brief Add definitions required for a smooth interaction between
+/// Objective-C++ automated reference counting and libstdc++ (4.2).
+static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts, 
+                                         MacroBuilder &Builder) {
+  Builder.defineMacro("_GLIBCXX_PREDEFINED_OBJC_ARC_IS_SCALAR");
+  
+  std::string Result;
+  {
+    // Provide specializations for the __is_scalar type trait so that 
+    // lifetime-qualified objects are not considered "scalar" types, which
+    // libstdc++ uses as an indicator of the presence of trivial copy, assign,
+    // default-construct, and destruct semantics (none of which hold for
+    // lifetime-qualified objects in ARC).
+    llvm::raw_string_ostream Out(Result);
+    
+    Out << "namespace std {\n"
+        << "\n"
+        << "struct __true_type;\n"
+        << "struct __false_type;\n"
+        << "\n";
+    
+    Out << "template<typename _Tp> struct __is_scalar;\n"
+        << "\n";
+      
+    Out << "template<typename _Tp>\n"
+        << "struct __is_scalar<__attribute__((objc_ownership(strong))) _Tp> {\n"
+        << "  enum { __value = 0 };\n"
+        << "  typedef __false_type __type;\n"
+        << "};\n"
+        << "\n";
+      
+    if (LangOpts.ObjCRuntimeHasWeak) {
+      Out << "template<typename _Tp>\n"
+          << "struct __is_scalar<__attribute__((objc_ownership(weak))) _Tp> {\n"
+          << "  enum { __value = 0 };\n"
+          << "  typedef __false_type __type;\n"
+          << "};\n"
+          << "\n";
+    }
+    
+    Out << "template<typename _Tp>\n"
+        << "struct __is_scalar<__attribute__((objc_ownership(autoreleasing)))"
+        << " _Tp> {\n"
+        << "  enum { __value = 0 };\n"
+        << "  typedef __false_type __type;\n"
+        << "};\n"
+        << "\n";
+      
+    Out << "}\n";
+  }
+  Builder.append(Result);
+}
+
+static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
+                                               const LangOptions &LangOpts,
+                                               const FrontendOptions &FEOpts,
+                                               MacroBuilder &Builder) {
+  if (!LangOpts.MicrosoftMode && !LangOpts.TraditionalCPP)
+    Builder.defineMacro("__STDC__");
+  if (LangOpts.Freestanding)
+    Builder.defineMacro("__STDC_HOSTED__", "0");
+  else
+    Builder.defineMacro("__STDC_HOSTED__");
+
+  if (!LangOpts.CPlusPlus) {
+    if (LangOpts.C11)
+      Builder.defineMacro("__STDC_VERSION__", "201112L");
+    else if (LangOpts.C99)
+      Builder.defineMacro("__STDC_VERSION__", "199901L");
+    else if (!LangOpts.GNUMode && LangOpts.Digraphs)
+      Builder.defineMacro("__STDC_VERSION__", "199409L");
+  } else {
+    if (LangOpts.GNUMode)
+      Builder.defineMacro("__cplusplus");
+    else {
+      // C++0x [cpp.predefined]p1:
+      //   The name_ _cplusplus is defined to the value 201103L when compiling a
+      //   C++ translation unit.
+      if (LangOpts.CPlusPlus0x)
+        Builder.defineMacro("__cplusplus", "201103L");
+      // C++03 [cpp.predefined]p1:
+      //   The name_ _cplusplus is defined to the value 199711L when compiling a
+      //   C++ translation unit.
+      else
+        Builder.defineMacro("__cplusplus", "199711L");
+    }
+  }
+
+  if (LangOpts.ObjC1)
+    Builder.defineMacro("__OBJC__");
+
+  // Not "standard" per se, but available even with the -undef flag.
+  if (LangOpts.AsmPreprocessor)
+    Builder.defineMacro("__ASSEMBLER__");
+}
+
+static void InitializePredefinedMacros(const TargetInfo &TI,
+                                       const LangOptions &LangOpts,
+                                       const FrontendOptions &FEOpts,
+                                       MacroBuilder &Builder) {
+  // Compiler version introspection macros.
+  Builder.defineMacro("__llvm__");  // LLVM Backend
+  Builder.defineMacro("__clang__"); // Clang Frontend
+#define TOSTR2(X) #X
+#define TOSTR(X) TOSTR2(X)
+  Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
+  Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
+#ifdef CLANG_VERSION_PATCHLEVEL
+  Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
+#else
+  Builder.defineMacro("__clang_patchlevel__", "0");
+#endif
+  Builder.defineMacro("__clang_version__", 
+                      "\"" CLANG_VERSION_STRING " ("
+                      + getClangFullRepositoryVersion() + ")\"");
+#undef TOSTR
+#undef TOSTR2
+  if (!LangOpts.MicrosoftMode) {
+    // Currently claim to be compatible with GCC 4.2.1-5621, but only if we're
+    // not compiling for MSVC compatibility
+    Builder.defineMacro("__GNUC_MINOR__", "2");
+    Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
+    Builder.defineMacro("__GNUC__", "4");
+    Builder.defineMacro("__GXX_ABI_VERSION", "1002");
+  }
+
+  // Define macros for the C11 / C++11 memory orderings
+  Builder.defineMacro("__ATOMIC_RELAXED", "0");
+  Builder.defineMacro("__ATOMIC_CONSUME", "1");
+  Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
+  Builder.defineMacro("__ATOMIC_RELEASE", "3");
+  Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
+  Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
+
+  // Support for #pragma redefine_extname (Sun compatibility)
+  Builder.defineMacro("__PRAGMA_REDEFINE_EXTNAME", "1");
+
+  // As sad as it is, enough software depends on the __VERSION__ for version
+  // checks that it is necessary to report 4.2.1 (the base GCC version we claim
+  // compatibility with) first.
+  Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible " + 
+                      Twine(getClangFullCPPVersion()) + "\"");
+
+  // Initialize language-specific preprocessor defines.
+
+  // Standard conforming mode?
+  if (!LangOpts.GNUMode)
+    Builder.defineMacro("__STRICT_ANSI__");
+
+  if (LangOpts.CPlusPlus0x)
+    Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
+
+  if (LangOpts.ObjC1) {
+    if (LangOpts.ObjCNonFragileABI) {
+      Builder.defineMacro("__OBJC2__");
+      
+      if (LangOpts.ObjCExceptions)
+        Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
+    }
+
+    if (LangOpts.getGC() != LangOptions::NonGC)
+      Builder.defineMacro("__OBJC_GC__");
+
+    if (LangOpts.NeXTRuntime)
+      Builder.defineMacro("__NEXT_RUNTIME__");
+  }
+
+  // darwin_constant_cfstrings controls this. This is also dependent
+  // on other things like the runtime I believe.  This is set even for C code.
+  if (!LangOpts.NoConstantCFStrings)
+      Builder.defineMacro("__CONSTANT_CFSTRINGS__");
+
+  if (LangOpts.ObjC2)
+    Builder.defineMacro("OBJC_NEW_PROPERTIES");
+
+  if (LangOpts.PascalStrings)
+    Builder.defineMacro("__PASCAL_STRINGS__");
+
+  if (LangOpts.Blocks) {
+    Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
+    Builder.defineMacro("__BLOCKS__");
+  }
+
+  if (LangOpts.CXXExceptions)
+    Builder.defineMacro("__EXCEPTIONS");
+  if (LangOpts.RTTI)
+    Builder.defineMacro("__GXX_RTTI");
+  if (LangOpts.SjLjExceptions)
+    Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
+
+  if (LangOpts.Deprecated)
+    Builder.defineMacro("__DEPRECATED");
+
+  if (LangOpts.CPlusPlus) {
+    Builder.defineMacro("__GNUG__", "4");
+    Builder.defineMacro("__GXX_WEAK__");
+    Builder.defineMacro("__private_extern__", "extern");
+  }
+
+  if (LangOpts.MicrosoftExt) {
+    // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
+    // VC++ appears to only like __FUNCTION__.
+    Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
+    // Work around some issues with Visual C++ headerws.
+    if (LangOpts.CPlusPlus) {
+      // Since we define wchar_t in C++ mode.
+      Builder.defineMacro("_WCHAR_T_DEFINED");
+      Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
+      // FIXME: Support Microsoft's __identifier extension in the lexer.
+      Builder.append("#define __identifier(x) x");
+      Builder.append("class type_info;");
+    }
+
+    if (LangOpts.CPlusPlus0x) {
+      Builder.defineMacro("_HAS_CHAR16_T_LANGUAGE_SUPPORT", "1");
+    }
+  }
+
+  if (LangOpts.Optimize)
+    Builder.defineMacro("__OPTIMIZE__");
+  if (LangOpts.OptimizeSize)
+    Builder.defineMacro("__OPTIMIZE_SIZE__");
+
+  if (LangOpts.FastMath)
+    Builder.defineMacro("__FAST_MATH__");
+
+  // Initialize target-specific preprocessor defines.
+
+  // Define type sizing macros based on the target properties.
+  assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
+  Builder.defineMacro("__CHAR_BIT__", "8");
+
+  DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
+  DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
+  DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
+  DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
+  DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
+  DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
+  DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
+
+  DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
+  DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
+                   TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_SIZE_T__",
+                   TI.getTypeWidth(TI.getSizeType()), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_WCHAR_T__",
+                   TI.getTypeWidth(TI.getWCharType()), TI, Builder);
+  DefineTypeSizeof("__SIZEOF_WINT_T__",
+                   TI.getTypeWidth(TI.getWIntType()), TI, Builder);
+
+  DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
+  DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
+  DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
+  DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
+  DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
+  DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
+  DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
+  DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
+  DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
+  DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
+  DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
+  DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
+  DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
+  DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
+  DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
+  DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
+
+  DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
+  DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
+  DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
+
+  // Define a __POINTER_WIDTH__ macro for stdint.h.
+  Builder.defineMacro("__POINTER_WIDTH__",
+                      Twine((int)TI.getPointerWidth(0)));
+
+  if (!LangOpts.CharIsSigned)
+    Builder.defineMacro("__CHAR_UNSIGNED__");
+
+  if (!TargetInfo::isTypeSigned(TI.getWIntType()))
+    Builder.defineMacro("__WINT_UNSIGNED__");
+
+  // Define exact-width integer types for stdint.h
+  Builder.defineMacro("__INT" + Twine(TI.getCharWidth()) + "_TYPE__",
+                      "char");
+
+  if (TI.getShortWidth() > TI.getCharWidth())
+    DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
+
+  if (TI.getIntWidth() > TI.getShortWidth())
+    DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
+
+  if (TI.getLongWidth() > TI.getIntWidth())
+    DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
+
+  if (TI.getLongLongWidth() > TI.getLongWidth())
+    DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
+
+  // Add __builtin_va_list typedef.
+  Builder.append(TI.getVAListDeclaration());
+
+  if (const char *Prefix = TI.getUserLabelPrefix())
+    Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
+
+  // Build configuration options.  FIXME: these should be controlled by
+  // command line options or something.
+  Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
+
+  if (LangOpts.GNUInline)
+    Builder.defineMacro("__GNUC_GNU_INLINE__");
+  else
+    Builder.defineMacro("__GNUC_STDC_INLINE__");
+
+  // The value written by __atomic_test_and_set.
+  // FIXME: This is target-dependent.
+  Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
+
+  // Used by libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
+  unsigned InlineWidthBits = TI.getMaxAtomicInlineWidth();
+#define DEFINE_LOCK_FREE_MACRO(TYPE, Type) \
+  Builder.defineMacro("__GCC_ATOMIC_" #TYPE "_LOCK_FREE", \
+                      getLockFreeValue(TI.get##Type##Width(), \
+                                       TI.get##Type##Align(), \
+                                       InlineWidthBits));
+  DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
+  DEFINE_LOCK_FREE_MACRO(CHAR, Char);
+  DEFINE_LOCK_FREE_MACRO(CHAR16_T, Char16);
+  DEFINE_LOCK_FREE_MACRO(CHAR32_T, Char32);
+  DEFINE_LOCK_FREE_MACRO(WCHAR_T, WChar);
+  DEFINE_LOCK_FREE_MACRO(SHORT, Short);
+  DEFINE_LOCK_FREE_MACRO(INT, Int);
+  DEFINE_LOCK_FREE_MACRO(LONG, Long);
+  DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
+  Builder.defineMacro("__GCC_ATOMIC_POINTER_LOCK_FREE",
+                      getLockFreeValue(TI.getPointerWidth(0),
+                                       TI.getPointerAlign(0),
+                                       InlineWidthBits));
+#undef DEFINE_LOCK_FREE_MACRO
+
+  if (LangOpts.NoInlineDefine)
+    Builder.defineMacro("__NO_INLINE__");
+
+  if (unsigned PICLevel = LangOpts.PICLevel) {
+    Builder.defineMacro("__PIC__", Twine(PICLevel));
+    Builder.defineMacro("__pic__", Twine(PICLevel));
+  }
+  if (unsigned PIELevel = LangOpts.PIELevel) {
+    Builder.defineMacro("__PIE__", Twine(PIELevel));
+    Builder.defineMacro("__pie__", Twine(PIELevel));
+  }
+
+  // Macros to control C99 numerics and <float.h>
+  Builder.defineMacro("__FLT_EVAL_METHOD__", Twine(TI.getFloatEvalMethod()));
+  Builder.defineMacro("__FLT_RADIX__", "2");
+  int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
+  Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));
+
+  if (LangOpts.getStackProtector() == LangOptions::SSPOn)
+    Builder.defineMacro("__SSP__");
+  else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
+    Builder.defineMacro("__SSP_ALL__", "2");
+
+  if (FEOpts.ProgramAction == frontend::RewriteObjC)
+    Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
+
+  // Define a macro that exists only when using the static analyzer.
+  if (FEOpts.ProgramAction == frontend::RunAnalysis)
+    Builder.defineMacro("__clang_analyzer__");
+
+  if (LangOpts.FastRelaxedMath)
+    Builder.defineMacro("__FAST_RELAXED_MATH__");
+
+  if (LangOpts.ObjCAutoRefCount) {
+    Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
+    Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
+    Builder.defineMacro("__autoreleasing",
+                        "__attribute__((objc_ownership(autoreleasing)))");
+    Builder.defineMacro("__unsafe_unretained",
+                        "__attribute__((objc_ownership(none)))");
+  }
+
+  // Get other target #defines.
+  TI.getTargetDefines(LangOpts, Builder);
+}
+
+// Initialize the remapping of files to alternative contents, e.g.,
+// those specified through other files.
+static void InitializeFileRemapping(DiagnosticsEngine &Diags,
+                                    SourceManager &SourceMgr,
+                                    FileManager &FileMgr,
+                                    const PreprocessorOptions &InitOpts) {
+  // Remap files in the source manager (with buffers).
+  for (PreprocessorOptions::const_remapped_file_buffer_iterator
+         Remap = InitOpts.remapped_file_buffer_begin(),
+         RemapEnd = InitOpts.remapped_file_buffer_end();
+       Remap != RemapEnd;
+       ++Remap) {
+    // Create the file entry for the file that we're mapping from.
+    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
+                                                Remap->second->getBufferSize(),
+                                                       0);
+    if (!FromFile) {
+      Diags.Report(diag::err_fe_remap_missing_from_file)
+        << Remap->first;
+      if (!InitOpts.RetainRemappedFileBuffers)
+        delete Remap->second;
+      continue;
+    }
+
+    // Override the contents of the "from" file with the contents of
+    // the "to" file.
+    SourceMgr.overrideFileContents(FromFile, Remap->second,
+                                   InitOpts.RetainRemappedFileBuffers);
+  }
+
+  // Remap files in the source manager (with other files).
+  for (PreprocessorOptions::const_remapped_file_iterator
+         Remap = InitOpts.remapped_file_begin(),
+         RemapEnd = InitOpts.remapped_file_end();
+       Remap != RemapEnd;
+       ++Remap) {
+    // Find the file that we're mapping to.
+    const FileEntry *ToFile = FileMgr.getFile(Remap->second);
+    if (!ToFile) {
+      Diags.Report(diag::err_fe_remap_missing_to_file)
+      << Remap->first << Remap->second;
+      continue;
+    }
+    
+    // Create the file entry for the file that we're mapping from.
+    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
+                                                       ToFile->getSize(), 0);
+    if (!FromFile) {
+      Diags.Report(diag::err_fe_remap_missing_from_file)
+      << Remap->first;
+      continue;
+    }
+    
+    // Override the contents of the "from" file with the contents of
+    // the "to" file.
+    SourceMgr.overrideFileContents(FromFile, ToFile);
+  }
+
+  SourceMgr.setOverridenFilesKeepOriginalName(
+                                        InitOpts.RemappedFilesKeepOriginalName);
+}
+
+/// InitializePreprocessor - Initialize the preprocessor getting it and the
+/// environment ready to process a single file. This returns true on error.
+///
+void clang::InitializePreprocessor(Preprocessor &PP,
+                                   const PreprocessorOptions &InitOpts,
+                                   const HeaderSearchOptions &HSOpts,
+                                   const FrontendOptions &FEOpts) {
+  const LangOptions &LangOpts = PP.getLangOpts();
+  std::string PredefineBuffer;
+  PredefineBuffer.reserve(4080);
+  llvm::raw_string_ostream Predefines(PredefineBuffer);
+  MacroBuilder Builder(Predefines);
+
+  InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
+                          PP.getFileManager(), InitOpts);
+
+  // Emit line markers for various builtin sections of the file.  We don't do
+  // this in asm preprocessor mode, because "# 4" is not a line marker directive
+  // in this mode.
+  if (!PP.getLangOpts().AsmPreprocessor)
+    Builder.append("# 1 \"<built-in>\" 3");
+
+  // Install things like __POWERPC__, __GNUC__, etc into the macro table.
+  if (InitOpts.UsePredefines) {
+    InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);
+
+    // Install definitions to make Objective-C++ ARC work well with various
+    // C++ Standard Library implementations.
+    if (LangOpts.ObjC1 && LangOpts.CPlusPlus && LangOpts.ObjCAutoRefCount) {
+      switch (InitOpts.ObjCXXARCStandardLibrary) {
+      case ARCXX_nolib:
+        case ARCXX_libcxx:
+        break;
+
+      case ARCXX_libstdcxx:
+        AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
+        break;
+      }
+    }
+  }
+  
+  // Even with predefines off, some macros are still predefined.
+  // These should all be defined in the preprocessor according to the
+  // current language configuration.
+  InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
+                                     FEOpts, Builder);
+
+  // Add on the predefines from the driver.  Wrap in a #line directive to report
+  // that they come from the command line.
+  if (!PP.getLangOpts().AsmPreprocessor)
+    Builder.append("# 1 \"<command line>\" 1");
+
+  // Process #define's and #undef's in the order they are given.
+  for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
+    if (InitOpts.Macros[i].second)  // isUndef
+      Builder.undefineMacro(InitOpts.Macros[i].first);
+    else
+      DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
+                         PP.getDiagnostics());
+  }
+
+  // If -imacros are specified, include them now.  These are processed before
+  // any -include directives.
+  for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
+    AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
+                             PP.getFileManager());
+
+  // Process -include directives.
+  for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
+    const std::string &Path = InitOpts.Includes[i];
+    if (Path == InitOpts.ImplicitPTHInclude)
+      AddImplicitIncludePTH(Builder, PP, Path);
+    else
+      AddImplicitInclude(Builder, Path, PP.getFileManager());
+  }
+
+  // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
+  if (!PP.getLangOpts().AsmPreprocessor)
+    Builder.append("# 1 \"<built-in>\" 2");
+
+  // Instruct the preprocessor to skip the preamble.
+  PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
+                             InitOpts.PrecompiledPreambleBytes.second);
+                          
+  // Copy PredefinedBuffer into the Preprocessor.
+  PP.setPredefines(Predefines.str());
+  
+  // Initialize the header search object.
+  ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
+                           PP.getLangOpts(),
+                           PP.getTargetInfo().getTriple());
+}
diff --git a/clang/lib/Frontend/LangStandards.cpp b/clang/lib/Frontend/LangStandards.cpp
new file mode 100644
index 0000000..f86a574
--- /dev/null
+++ b/clang/lib/Frontend/LangStandards.cpp
@@ -0,0 +1,43 @@
+//===--- LangStandards.cpp - Language Standard Definitions ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/LangStandard.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/ErrorHandling.h"
+using namespace clang;
+using namespace clang::frontend;
+
+#define LANGSTANDARD(id, name, desc, features) \
+  static const LangStandard Lang_##id = { name, desc, features };
+#include "clang/Frontend/LangStandards.def"
+
+const LangStandard &LangStandard::getLangStandardForKind(Kind K) {
+  switch (K) {
+  case lang_unspecified:
+    llvm::report_fatal_error("getLangStandardForKind() on unspecified kind");
+#define LANGSTANDARD(id, name, desc, features) \
+    case lang_##id: return Lang_##id;
+#include "clang/Frontend/LangStandards.def"
+  }
+  llvm_unreachable("Invalid language kind!");
+}
+
+const LangStandard *LangStandard::getLangStandardForName(StringRef Name) {
+  Kind K = llvm::StringSwitch<Kind>(Name)
+#define LANGSTANDARD(id, name, desc, features) \
+    .Case(name, lang_##id)
+#include "clang/Frontend/LangStandards.def"
+    .Default(lang_unspecified);
+  if (K == lang_unspecified)
+    return 0;
+
+  return &getLangStandardForKind(K);
+}
+
+
diff --git a/clang/lib/Frontend/LayoutOverrideSource.cpp b/clang/lib/Frontend/LayoutOverrideSource.cpp
new file mode 100644
index 0000000..eb7865e
--- /dev/null
+++ b/clang/lib/Frontend/LayoutOverrideSource.cpp
@@ -0,0 +1,206 @@
+//===--- LayoutOverrideSource.cpp --Override Record Layouts ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Frontend/LayoutOverrideSource.h"
+#include "clang/AST/Decl.h"
+#include "llvm/Support/raw_ostream.h"
+#include <fstream>
+#include <string>
+
+using namespace clang;
+
+/// \brief Parse a simple identifier.
+static std::string parseName(StringRef S) {
+  unsigned Offset = 0;
+  while (Offset < S.size() &&
+         (isalpha(S[Offset]) || S[Offset] == '_' ||
+          (Offset > 0 && isdigit(S[Offset]))))
+    ++Offset;
+  
+  return S.substr(0, Offset).str();
+}
+
+LayoutOverrideSource::LayoutOverrideSource(llvm::StringRef Filename) {
+  std::ifstream Input(Filename.str().c_str());
+  if (!Input.is_open())
+    return;
+  
+  // Parse the output of -fdump-record-layouts.
+  std::string CurrentType;
+  Layout CurrentLayout;
+  bool ExpectingType = false;
+  
+  while (Input.good()) {
+    std::string Line;
+    getline(Input, Line);
+    
+    StringRef LineStr(Line);
+
+    // Determine whether the following line will start a 
+    if (LineStr.find("*** Dumping AST Record Layout") != StringRef::npos)  {
+      // Flush the last type/layout, if there is one.
+      if (!CurrentType.empty())
+        Layouts[CurrentType] = CurrentLayout;
+      CurrentLayout = Layout();
+      
+      ExpectingType = true;
+      continue;
+    }
+    
+    // If we're expecting a type, grab it.
+    if (ExpectingType) {
+      ExpectingType = false;
+      
+      StringRef::size_type Pos;
+      if ((Pos = LineStr.find("struct ")) != StringRef::npos)
+        LineStr = LineStr.substr(Pos + strlen("struct "));
+      else if ((Pos = LineStr.find("class ")) != StringRef::npos)
+        LineStr = LineStr.substr(Pos + strlen("class "));
+      else if ((Pos = LineStr.find("union ")) != StringRef::npos)
+        LineStr = LineStr.substr(Pos + strlen("union "));
+      else
+        continue;
+      
+      // Find the name of the type.
+      CurrentType = parseName(LineStr);
+      CurrentLayout = Layout();
+      continue;
+    }
+    
+    // Check for the size of the type.
+    StringRef::size_type Pos = LineStr.find(" Size:");
+    if (Pos != StringRef::npos) {
+      // Skip past the " Size:" prefix.
+      LineStr = LineStr.substr(Pos + strlen(" Size:"));
+      
+      unsigned long long Size = 0;
+      (void)LineStr.getAsInteger(10, Size);
+      CurrentLayout.Size = Size;
+      continue;
+    }
+
+    // Check for the alignment of the type.
+    Pos = LineStr.find("Alignment:");
+    if (Pos != StringRef::npos) {
+      // Skip past the "Alignment:" prefix.
+      LineStr = LineStr.substr(Pos + strlen("Alignment:"));
+      
+      unsigned long long Alignment = 0;
+      (void)LineStr.getAsInteger(10, Alignment);
+      CurrentLayout.Align = Alignment;
+      continue;
+    }
+    
+    // Check for the size/alignment of the type.
+    Pos = LineStr.find("sizeof=");
+    if (Pos != StringRef::npos) {
+      /* Skip past the sizeof= prefix. */
+      LineStr = LineStr.substr(Pos + strlen("sizeof="));
+
+      // Parse size.
+      unsigned long long Size = 0;
+      (void)LineStr.getAsInteger(10, Size);
+      CurrentLayout.Size = Size;
+
+      Pos = LineStr.find("align=");
+      if (Pos != StringRef::npos) {
+        /* Skip past the align= prefix. */
+        LineStr = LineStr.substr(Pos + strlen("align="));
+        
+        // Parse alignment.
+        unsigned long long Alignment = 0;
+        (void)LineStr.getAsInteger(10, Alignment);
+        CurrentLayout.Align = Alignment;
+      }
+      
+      continue;
+    }
+    
+    // Check for the field offsets of the type.
+    Pos = LineStr.find("FieldOffsets: [");
+    if (Pos == StringRef::npos)
+      continue;
+
+    LineStr = LineStr.substr(Pos + strlen("FieldOffsets: ["));
+    while (!LineStr.empty() && isdigit(LineStr[0])) {
+      // Parse this offset.
+      unsigned Idx = 1;
+      while (Idx < LineStr.size() && isdigit(LineStr[Idx]))
+        ++Idx;
+      
+      unsigned long long Offset = 0;
+      (void)LineStr.substr(0, Idx).getAsInteger(10, Offset);
+      
+      CurrentLayout.FieldOffsets.push_back(Offset);
+      
+      // Skip over this offset, the following comma, and any spaces.
+      LineStr = LineStr.substr(Idx + 1);
+      while (!LineStr.empty() && isspace(LineStr[0]))
+        LineStr = LineStr.substr(1);
+    }
+  }
+  
+  // Flush the last type/layout, if there is one.
+  if (!CurrentType.empty())
+    Layouts[CurrentType] = CurrentLayout;
+}
+
+bool 
+LayoutOverrideSource::layoutRecordType(const RecordDecl *Record,
+  uint64_t &Size, uint64_t &Alignment,
+  llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
+  llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
+  llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets) 
+{
+  // We can't override unnamed declarations.
+  if (!Record->getIdentifier())
+    return false;
+  
+  // Check whether we have a layout for this record.
+  llvm::StringMap<Layout>::iterator Known = Layouts.find(Record->getName());
+  if (Known == Layouts.end())
+    return false;
+  
+  // Provide field layouts.
+  unsigned NumFields = 0;
+  for (RecordDecl::field_iterator F = Record->field_begin(), 
+                               FEnd = Record->field_end();
+       F != FEnd; ++F, ++NumFields) {
+    if (NumFields >= Known->second.FieldOffsets.size())
+      continue;
+    
+    FieldOffsets[*F] = Known->second.FieldOffsets[NumFields];
+  }
+  
+  // Wrong number of fields.
+  if (NumFields != Known->second.FieldOffsets.size())
+    return false;
+  
+  Size = Known->second.Size;
+  Alignment = Known->second.Align;
+  return true;
+}
+
+void LayoutOverrideSource::dump() {
+  llvm::raw_ostream &OS = llvm::errs();
+  for (llvm::StringMap<Layout>::iterator L = Layouts.begin(), 
+                                      LEnd = Layouts.end();
+       L != LEnd; ++L) {
+    OS << "Type: blah " << L->first() << '\n';
+    OS << "  Size:" << L->second.Size << '\n';
+    OS << "  Alignment:" << L->second.Align << '\n';
+    OS << "  FieldOffsets: [";
+    for (unsigned I = 0, N = L->second.FieldOffsets.size(); I != N; ++I) {
+      if (I)
+        OS << ", ";
+      OS << L->second.FieldOffsets[I];
+    }
+    OS << "]\n";
+  }
+}
+
diff --git a/clang/lib/Frontend/LogDiagnosticPrinter.cpp b/clang/lib/Frontend/LogDiagnosticPrinter.cpp
new file mode 100644
index 0000000..3fee957
--- /dev/null
+++ b/clang/lib/Frontend/LogDiagnosticPrinter.cpp
@@ -0,0 +1,177 @@
+//===--- LogDiagnosticPrinter.cpp - Log Diagnostic Printer ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/LogDiagnosticPrinter.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+using namespace clang;
+
+LogDiagnosticPrinter::LogDiagnosticPrinter(raw_ostream &os,
+                                           const DiagnosticOptions &diags,
+                                           bool _OwnsOutputStream)
+  : OS(os), LangOpts(0), DiagOpts(&diags),
+    OwnsOutputStream(_OwnsOutputStream) {
+}
+
+LogDiagnosticPrinter::~LogDiagnosticPrinter() {
+  if (OwnsOutputStream)
+    delete &OS;
+}
+
+static StringRef getLevelName(DiagnosticsEngine::Level Level) {
+  switch (Level) {
+  case DiagnosticsEngine::Ignored: return "ignored";
+  case DiagnosticsEngine::Note:    return "note";
+  case DiagnosticsEngine::Warning: return "warning";
+  case DiagnosticsEngine::Error:   return "error";
+  case DiagnosticsEngine::Fatal:   return "fatal error";
+  }
+  llvm_unreachable("Invalid DiagnosticsEngine level!");
+}
+
+// Escape XML characters inside the raw string.
+static void emitString(llvm::raw_svector_ostream &OS, const StringRef Raw) {
+  for (StringRef::iterator I = Raw.begin(), E = Raw.end(); I != E; ++I) {
+    char c = *I;
+    switch (c) {
+    default:   OS << c; break;
+    case '&':  OS << "&amp;"; break;
+    case '<':  OS << "&lt;"; break;
+    case '>':  OS << "&gt;"; break;
+    case '\'': OS << "&apos;"; break;
+    case '\"': OS << "&quot;"; break;
+    }
+  }
+}
+
+void LogDiagnosticPrinter::EndSourceFile() {
+  // We emit all the diagnostics in EndSourceFile. However, we don't emit any
+  // entry if no diagnostics were present.
+  //
+  // Note that DiagnosticConsumer has no "end-of-compilation" callback, so we
+  // will miss any diagnostics which are emitted after and outside the
+  // translation unit processing.
+  if (Entries.empty())
+    return;
+
+  // Write to a temporary string to ensure atomic write of diagnostic object.
+  SmallString<512> Msg;
+  llvm::raw_svector_ostream OS(Msg);
+
+  OS << "<dict>\n";
+  if (!MainFilename.empty()) {
+    OS << "  <key>main-file</key>\n"
+       << "  <string>";
+    emitString(OS, MainFilename);
+    OS << "</string>\n";
+  }
+  if (!DwarfDebugFlags.empty()) {
+    OS << "  <key>dwarf-debug-flags</key>\n"
+       << "  <string>";
+    emitString(OS, DwarfDebugFlags);
+    OS << "</string>\n";
+  }
+  OS << "  <key>diagnostics</key>\n";
+  OS << "  <array>\n";
+  for (unsigned i = 0, e = Entries.size(); i != e; ++i) {
+    DiagEntry &DE = Entries[i];
+
+    OS << "    <dict>\n";
+    OS << "      <key>level</key>\n"
+       << "      <string>";
+    emitString(OS, getLevelName(DE.DiagnosticLevel));
+    OS << "</string>\n";
+    if (!DE.Filename.empty()) {
+      OS << "      <key>filename</key>\n"
+         << "      <string>";
+      emitString(OS, DE.Filename);
+      OS << "</string>\n";
+    }
+    if (DE.Line != 0) {
+      OS << "      <key>line</key>\n"
+         << "      <integer>" << DE.Line << "</integer>\n";
+    }
+    if (DE.Column != 0) {
+      OS << "      <key>column</key>\n"
+         << "      <integer>" << DE.Column << "</integer>\n";
+    }
+    if (!DE.Message.empty()) {
+      OS << "      <key>message</key>\n"
+         << "      <string>";
+      emitString(OS, DE.Message);
+      OS << "</string>\n";
+    }
+    OS << "    </dict>\n";
+  }
+  OS << "  </array>\n";
+  OS << "</dict>\n";
+
+  this->OS << OS.str();
+}
+
+void LogDiagnosticPrinter::HandleDiagnostic(DiagnosticsEngine::Level Level,
+                                            const Diagnostic &Info) {
+  // Default implementation (Warnings/errors count).
+  DiagnosticConsumer::HandleDiagnostic(Level, Info);
+
+  // Initialize the main file name, if we haven't already fetched it.
+  if (MainFilename.empty() && Info.hasSourceManager()) {
+    const SourceManager &SM = Info.getSourceManager();
+    FileID FID = SM.getMainFileID();
+    if (!FID.isInvalid()) {
+      const FileEntry *FE = SM.getFileEntryForID(FID);
+      if (FE && FE->getName())
+        MainFilename = FE->getName();
+    }
+  }
+
+  // Create the diag entry.
+  DiagEntry DE;
+  DE.DiagnosticID = Info.getID();
+  DE.DiagnosticLevel = Level;
+
+  // Format the message.
+  SmallString<100> MessageStr;
+  Info.FormatDiagnostic(MessageStr);
+  DE.Message = MessageStr.str();
+
+  // Set the location information.
+  DE.Filename = "";
+  DE.Line = DE.Column = 0;
+  if (Info.getLocation().isValid() && Info.hasSourceManager()) {
+    const SourceManager &SM = Info.getSourceManager();
+    PresumedLoc PLoc = SM.getPresumedLoc(Info.getLocation());
+
+    if (PLoc.isInvalid()) {
+      // At least print the file name if available:
+      FileID FID = SM.getFileID(Info.getLocation());
+      if (!FID.isInvalid()) {
+        const FileEntry *FE = SM.getFileEntryForID(FID);
+        if (FE && FE->getName())
+          DE.Filename = FE->getName();
+      }
+    } else {
+      DE.Filename = PLoc.getFilename();
+      DE.Line = PLoc.getLine();
+      DE.Column = PLoc.getColumn();
+    }
+  }
+
+  // Record the diagnostic entry.
+  Entries.push_back(DE);
+}
+
+DiagnosticConsumer *
+LogDiagnosticPrinter::clone(DiagnosticsEngine &Diags) const {
+  return new LogDiagnosticPrinter(OS, *DiagOpts, /*OwnsOutputStream=*/false);
+}
+
diff --git a/clang/lib/Frontend/Makefile b/clang/lib/Frontend/Makefile
new file mode 100644
index 0000000..3c13ad6
--- /dev/null
+++ b/clang/lib/Frontend/Makefile
@@ -0,0 +1,14 @@
+##===- clang/lib/Frontend/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+CLANG_LEVEL := ../..
+LIBRARYNAME := clangFrontend
+
+include $(CLANG_LEVEL)/Makefile
+
diff --git a/clang/lib/Frontend/MultiplexConsumer.cpp b/clang/lib/Frontend/MultiplexConsumer.cpp
new file mode 100644
index 0000000..992eeb0
--- /dev/null
+++ b/clang/lib/Frontend/MultiplexConsumer.cpp
@@ -0,0 +1,276 @@
+//===- MultiplexConsumer.cpp - AST Consumer for PCH Generation --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the MultiplexConsumer class. It also declares and defines
+//  MultiplexASTDeserializationListener and  MultiplexASTMutationListener, which
+//  are implementation details of MultiplexConsumer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/MultiplexConsumer.h"
+
+#include "clang/AST/ASTMutationListener.h"
+#include "clang/AST/DeclGroup.h"
+#include "clang/Serialization/ASTDeserializationListener.h"
+
+using namespace clang;
+
+namespace clang {
+
+// This ASTDeserializationListener forwards its notifications to a set of
+// child listeners.
+class MultiplexASTDeserializationListener
+    : public ASTDeserializationListener {
+public:
+  // Does NOT take ownership of the elements in L.
+  MultiplexASTDeserializationListener(
+      const std::vector<ASTDeserializationListener*>& L);
+  virtual void ReaderInitialized(ASTReader *Reader);
+  virtual void IdentifierRead(serialization::IdentID ID,
+                              IdentifierInfo *II);
+  virtual void TypeRead(serialization::TypeIdx Idx, QualType T);
+  virtual void DeclRead(serialization::DeclID ID, const Decl *D);
+  virtual void SelectorRead(serialization::SelectorID iD, Selector Sel);
+  virtual void MacroDefinitionRead(serialization::PreprocessedEntityID, 
+                                   MacroDefinition *MD);
+private:
+  std::vector<ASTDeserializationListener*> Listeners;
+};
+
+MultiplexASTDeserializationListener::MultiplexASTDeserializationListener(
+      const std::vector<ASTDeserializationListener*>& L)
+    : Listeners(L) {
+}
+
+void MultiplexASTDeserializationListener::ReaderInitialized(
+    ASTReader *Reader) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->ReaderInitialized(Reader);
+}
+
+void MultiplexASTDeserializationListener::IdentifierRead(
+    serialization::IdentID ID, IdentifierInfo *II) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->IdentifierRead(ID, II);
+}
+
+void MultiplexASTDeserializationListener::TypeRead(
+    serialization::TypeIdx Idx, QualType T) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->TypeRead(Idx, T);
+}
+
+void MultiplexASTDeserializationListener::DeclRead(
+    serialization::DeclID ID, const Decl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->DeclRead(ID, D);
+}
+
+void MultiplexASTDeserializationListener::SelectorRead(
+    serialization::SelectorID ID, Selector Sel) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->SelectorRead(ID, Sel);
+}
+
+void MultiplexASTDeserializationListener::MacroDefinitionRead(
+    serialization::PreprocessedEntityID ID, MacroDefinition *MD) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->MacroDefinitionRead(ID, MD);
+}
+
+// This ASTMutationListener forwards its notifications to a set of
+// child listeners.
+class MultiplexASTMutationListener : public ASTMutationListener {
+public:
+  // Does NOT take ownership of the elements in L.
+  MultiplexASTMutationListener(ArrayRef<ASTMutationListener*> L);
+  virtual void CompletedTagDefinition(const TagDecl *D);
+  virtual void AddedVisibleDecl(const DeclContext *DC, const Decl *D);
+  virtual void AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D);
+  virtual void AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,
+                                    const ClassTemplateSpecializationDecl *D);
+  virtual void AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
+                                              const FunctionDecl *D);
+  virtual void CompletedImplicitDefinition(const FunctionDecl *D);
+  virtual void StaticDataMemberInstantiated(const VarDecl *D);
+  virtual void AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
+                                            const ObjCInterfaceDecl *IFD);
+  virtual void AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
+                                            const ObjCPropertyDecl *OrigProp,
+                                            const ObjCCategoryDecl *ClassExt);
+private:
+  std::vector<ASTMutationListener*> Listeners;
+};
+
+MultiplexASTMutationListener::MultiplexASTMutationListener(
+    ArrayRef<ASTMutationListener*> L)
+    : Listeners(L.begin(), L.end()) {
+}
+
+void MultiplexASTMutationListener::CompletedTagDefinition(const TagDecl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->CompletedTagDefinition(D);
+}
+
+void MultiplexASTMutationListener::AddedVisibleDecl(
+    const DeclContext *DC, const Decl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedVisibleDecl(DC, D);
+}
+
+void MultiplexASTMutationListener::AddedCXXImplicitMember(
+    const CXXRecordDecl *RD, const Decl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedCXXImplicitMember(RD, D);
+}
+void MultiplexASTMutationListener::AddedCXXTemplateSpecialization(
+    const ClassTemplateDecl *TD, const ClassTemplateSpecializationDecl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedCXXTemplateSpecialization(TD, D);
+}
+void MultiplexASTMutationListener::AddedCXXTemplateSpecialization(
+    const FunctionTemplateDecl *TD, const FunctionDecl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedCXXTemplateSpecialization(TD, D);
+}
+void MultiplexASTMutationListener::CompletedImplicitDefinition(
+                                                        const FunctionDecl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->CompletedImplicitDefinition(D);
+}
+void MultiplexASTMutationListener::StaticDataMemberInstantiated(
+                                                             const VarDecl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->StaticDataMemberInstantiated(D);
+}
+void MultiplexASTMutationListener::AddedObjCCategoryToInterface(
+                                                 const ObjCCategoryDecl *CatD,
+                                                 const ObjCInterfaceDecl *IFD) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedObjCCategoryToInterface(CatD, IFD);
+}
+void MultiplexASTMutationListener::AddedObjCPropertyInClassExtension(
+                                             const ObjCPropertyDecl *Prop,
+                                             const ObjCPropertyDecl *OrigProp,
+                                             const ObjCCategoryDecl *ClassExt) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->AddedObjCPropertyInClassExtension(Prop, OrigProp, ClassExt);
+}
+
+}  // end namespace clang
+
+
+MultiplexConsumer::MultiplexConsumer(ArrayRef<ASTConsumer*> C)
+    : Consumers(C.begin(), C.end()),
+      MutationListener(0), DeserializationListener(0) {
+  // Collect the mutation listeners and deserialization listeners of all
+  // children, and create a multiplex listener each if so.
+  std::vector<ASTMutationListener*> mutationListeners;
+  std::vector<ASTDeserializationListener*> serializationListeners;
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i) {
+    ASTMutationListener* mutationListener =
+        Consumers[i]->GetASTMutationListener();
+    if (mutationListener)
+      mutationListeners.push_back(mutationListener);
+    ASTDeserializationListener* serializationListener =
+        Consumers[i]->GetASTDeserializationListener();
+    if (serializationListener)
+      serializationListeners.push_back(serializationListener);
+  }
+  if (mutationListeners.size()) {
+    MutationListener.reset(new MultiplexASTMutationListener(mutationListeners));
+  }
+  if (serializationListeners.size()) {
+    DeserializationListener.reset(
+        new MultiplexASTDeserializationListener(serializationListeners));
+  }
+}
+
+MultiplexConsumer::~MultiplexConsumer() {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    delete Consumers[i];
+}
+
+void MultiplexConsumer::Initialize(ASTContext &Context) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->Initialize(Context);
+}
+
+bool MultiplexConsumer::HandleTopLevelDecl(DeclGroupRef D) {
+  bool Continue = true;
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Continue = Continue && Consumers[i]->HandleTopLevelDecl(D);
+  return Continue;
+}
+
+void  MultiplexConsumer::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleCXXStaticMemberVarInstantiation(VD);
+}
+
+void MultiplexConsumer::HandleInterestingDecl(DeclGroupRef D) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleInterestingDecl(D);
+}
+
+void MultiplexConsumer::HandleTranslationUnit(ASTContext &Ctx) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleTranslationUnit(Ctx);
+}
+
+void MultiplexConsumer::HandleTagDeclDefinition(TagDecl *D) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleTagDeclDefinition(D);
+}
+
+void MultiplexConsumer::HandleCXXImplicitFunctionInstantiation(FunctionDecl *D){
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleCXXImplicitFunctionInstantiation(D);
+}
+
+void MultiplexConsumer::HandleTopLevelDeclInObjCContainer(DeclGroupRef D) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleTopLevelDeclInObjCContainer(D);
+}
+
+void MultiplexConsumer::CompleteTentativeDefinition(VarDecl *D) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->CompleteTentativeDefinition(D);
+}
+
+void MultiplexConsumer::HandleVTable(
+    CXXRecordDecl *RD, bool DefinitionRequired) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->HandleVTable(RD, DefinitionRequired);
+}
+
+ASTMutationListener *MultiplexConsumer::GetASTMutationListener() {
+  return MutationListener.get();
+}
+
+ASTDeserializationListener *MultiplexConsumer::GetASTDeserializationListener() {
+  return DeserializationListener.get();
+}
+
+void MultiplexConsumer::PrintStats() {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    Consumers[i]->PrintStats();
+}
+
+void MultiplexConsumer::InitializeSema(Sema &S) {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    if (SemaConsumer *SC = dyn_cast<SemaConsumer>(Consumers[i]))
+      SC->InitializeSema(S);
+}
+
+void MultiplexConsumer::ForgetSema() {
+  for (size_t i = 0, e = Consumers.size(); i != e; ++i)
+    if (SemaConsumer *SC = dyn_cast<SemaConsumer>(Consumers[i]))
+      SC->ForgetSema();
+}
diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
new file mode 100644
index 0000000..9e1587c
--- /dev/null
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -0,0 +1,628 @@
+//===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code simply runs the preprocessor on the input file and prints out the
+// result.  This is the traditional behavior of the -E option.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/PreprocessorOutputOptions.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Pragma.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/TokenConcatenation.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <cstdio>
+using namespace clang;
+
+/// PrintMacroDefinition - Print a macro definition in a form that will be
+/// properly accepted back as a definition.
+static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
+                                 Preprocessor &PP, raw_ostream &OS) {
+  OS << "#define " << II.getName();
+
+  if (MI.isFunctionLike()) {
+    OS << '(';
+    if (!MI.arg_empty()) {
+      MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
+      for (; AI+1 != E; ++AI) {
+        OS << (*AI)->getName();
+        OS << ',';
+      }
+
+      // Last argument.
+      if ((*AI)->getName() == "__VA_ARGS__")
+        OS << "...";
+      else
+        OS << (*AI)->getName();
+    }
+
+    if (MI.isGNUVarargs())
+      OS << "...";  // #define foo(x...)
+
+    OS << ')';
+  }
+
+  // GCC always emits a space, even if the macro body is empty.  However, do not
+  // want to emit two spaces if the first token has a leading space.
+  if (MI.tokens_empty() || !MI.tokens_begin()->hasLeadingSpace())
+    OS << ' ';
+
+  SmallString<128> SpellingBuffer;
+  for (MacroInfo::tokens_iterator I = MI.tokens_begin(), E = MI.tokens_end();
+       I != E; ++I) {
+    if (I->hasLeadingSpace())
+      OS << ' ';
+
+    OS << PP.getSpelling(*I, SpellingBuffer);
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Preprocessed token printer
+//===----------------------------------------------------------------------===//
+
+namespace {
+class PrintPPOutputPPCallbacks : public PPCallbacks {
+  Preprocessor &PP;
+  SourceManager &SM;
+  TokenConcatenation ConcatInfo;
+public:
+  raw_ostream &OS;
+private:
+  unsigned CurLine;
+
+  bool EmittedTokensOnThisLine;
+  bool EmittedMacroOnThisLine;
+  SrcMgr::CharacteristicKind FileType;
+  SmallString<512> CurFilename;
+  bool Initialized;
+  bool DisableLineMarkers;
+  bool DumpDefines;
+  bool UseLineDirective;
+public:
+  PrintPPOutputPPCallbacks(Preprocessor &pp, raw_ostream &os,
+                           bool lineMarkers, bool defines)
+     : PP(pp), SM(PP.getSourceManager()),
+       ConcatInfo(PP), OS(os), DisableLineMarkers(lineMarkers),
+       DumpDefines(defines) {
+    CurLine = 0;
+    CurFilename += "<uninit>";
+    EmittedTokensOnThisLine = false;
+    EmittedMacroOnThisLine = false;
+    FileType = SrcMgr::C_User;
+    Initialized = false;
+
+    // If we're in microsoft mode, use normal #line instead of line markers.
+    UseLineDirective = PP.getLangOpts().MicrosoftExt;
+  }
+
+  void SetEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
+  bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }
+
+  bool StartNewLineIfNeeded();
+  
+  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                           SrcMgr::CharacteristicKind FileType,
+                           FileID PrevFID);
+  virtual void Ident(SourceLocation Loc, const std::string &str);
+  virtual void PragmaComment(SourceLocation Loc, const IdentifierInfo *Kind,
+                             const std::string &Str);
+  virtual void PragmaMessage(SourceLocation Loc, StringRef Str);
+  virtual void PragmaDiagnosticPush(SourceLocation Loc,
+                                    StringRef Namespace);
+  virtual void PragmaDiagnosticPop(SourceLocation Loc,
+                                   StringRef Namespace);
+  virtual void PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
+                                diag::Mapping Map, StringRef Str);
+
+  bool HandleFirstTokOnLine(Token &Tok);
+  bool MoveToLine(SourceLocation Loc) {
+    PresumedLoc PLoc = SM.getPresumedLoc(Loc);
+    if (PLoc.isInvalid())
+      return false;
+    return MoveToLine(PLoc.getLine());
+  }
+  bool MoveToLine(unsigned LineNo);
+
+  bool AvoidConcat(const Token &PrevPrevTok, const Token &PrevTok, 
+                   const Token &Tok) {
+    return ConcatInfo.AvoidConcat(PrevPrevTok, PrevTok, Tok);
+  }
+  void WriteLineInfo(unsigned LineNo, const char *Extra=0, unsigned ExtraLen=0);
+  bool LineMarkersAreDisabled() const { return DisableLineMarkers; }
+  void HandleNewlinesInToken(const char *TokStr, unsigned Len);
+
+  /// MacroDefined - This hook is called whenever a macro definition is seen.
+  void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI);
+
+  /// MacroUndefined - This hook is called whenever a macro #undef is seen.
+  void MacroUndefined(const Token &MacroNameTok, const MacroInfo *MI);
+};
+}  // end anonymous namespace
+
+void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
+                                             const char *Extra,
+                                             unsigned ExtraLen) {
+  if (EmittedTokensOnThisLine || EmittedMacroOnThisLine) {
+    OS << '\n';
+    EmittedTokensOnThisLine = false;
+    EmittedMacroOnThisLine = false;
+  }
+
+  // Emit #line directives or GNU line markers depending on what mode we're in.
+  if (UseLineDirective) {
+    OS << "#line" << ' ' << LineNo << ' ' << '"';
+    OS.write(CurFilename.data(), CurFilename.size());
+    OS << '"';
+  } else {
+    OS << '#' << ' ' << LineNo << ' ' << '"';
+    OS.write(CurFilename.data(), CurFilename.size());
+    OS << '"';
+
+    if (ExtraLen)
+      OS.write(Extra, ExtraLen);
+
+    if (FileType == SrcMgr::C_System)
+      OS.write(" 3", 2);
+    else if (FileType == SrcMgr::C_ExternCSystem)
+      OS.write(" 3 4", 4);
+  }
+  OS << '\n';
+}
+
+/// MoveToLine - Move the output to the source line specified by the location
+/// object.  We can do this by emitting some number of \n's, or be emitting a
+/// #line directive.  This returns false if already at the specified line, true
+/// if some newlines were emitted.
+bool PrintPPOutputPPCallbacks::MoveToLine(unsigned LineNo) {
+  // If this line is "close enough" to the original line, just print newlines,
+  // otherwise print a #line directive.
+  if (LineNo-CurLine <= 8) {
+    if (LineNo-CurLine == 1)
+      OS << '\n';
+    else if (LineNo == CurLine)
+      return false;    // Spelling line moved, but expansion line didn't.
+    else {
+      const char *NewLines = "\n\n\n\n\n\n\n\n";
+      OS.write(NewLines, LineNo-CurLine);
+    }
+  } else if (!DisableLineMarkers) {
+    // Emit a #line or line marker.
+    WriteLineInfo(LineNo, 0, 0);
+  } else {
+    // Okay, we're in -P mode, which turns off line markers.  However, we still
+    // need to emit a newline between tokens on different lines.
+    if (EmittedTokensOnThisLine || EmittedMacroOnThisLine) {
+      OS << '\n';
+      EmittedTokensOnThisLine = false;
+      EmittedMacroOnThisLine = false;
+    }
+  }
+
+  CurLine = LineNo;
+  return true;
+}
+
+bool PrintPPOutputPPCallbacks::StartNewLineIfNeeded() {
+  if (EmittedTokensOnThisLine || EmittedMacroOnThisLine) {
+    OS << '\n';
+    EmittedTokensOnThisLine = false;
+    EmittedMacroOnThisLine = false;
+    ++CurLine;
+    return true;
+  }
+  
+  return false;
+}
+
+/// FileChanged - Whenever the preprocessor enters or exits a #include file
+/// it invokes this handler.  Update our conception of the current source
+/// position.
+void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
+                                           FileChangeReason Reason,
+                                       SrcMgr::CharacteristicKind NewFileType,
+                                       FileID PrevFID) {
+  // Unless we are exiting a #include, make sure to skip ahead to the line the
+  // #include directive was at.
+  SourceManager &SourceMgr = SM;
+  
+  PresumedLoc UserLoc = SourceMgr.getPresumedLoc(Loc);
+  if (UserLoc.isInvalid())
+    return;
+  
+  unsigned NewLine = UserLoc.getLine();
+
+  if (Reason == PPCallbacks::EnterFile) {
+    SourceLocation IncludeLoc = UserLoc.getIncludeLoc();
+    if (IncludeLoc.isValid())
+      MoveToLine(IncludeLoc);
+  } else if (Reason == PPCallbacks::SystemHeaderPragma) {
+    MoveToLine(NewLine);
+
+    // TODO GCC emits the # directive for this directive on the line AFTER the
+    // directive and emits a bunch of spaces that aren't needed.  Emulate this
+    // strange behavior.
+  }
+  
+  CurLine = NewLine;
+
+  CurFilename.clear();
+  CurFilename += UserLoc.getFilename();
+  Lexer::Stringify(CurFilename);
+  FileType = NewFileType;
+
+  if (DisableLineMarkers) return;
+  
+  if (!Initialized) {
+    WriteLineInfo(CurLine);
+    Initialized = true;
+  }
+
+  switch (Reason) {
+  case PPCallbacks::EnterFile:
+    WriteLineInfo(CurLine, " 1", 2);
+    break;
+  case PPCallbacks::ExitFile:
+    WriteLineInfo(CurLine, " 2", 2);
+    break;
+  case PPCallbacks::SystemHeaderPragma:
+  case PPCallbacks::RenameFile:
+    WriteLineInfo(CurLine);
+    break;
+  }
+}
+
+/// Ident - Handle #ident directives when read by the preprocessor.
+///
+void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, const std::string &S) {
+  MoveToLine(Loc);
+
+  OS.write("#ident ", strlen("#ident "));
+  OS.write(&S[0], S.size());
+  EmittedTokensOnThisLine = true;
+}
+
+/// MacroDefined - This hook is called whenever a macro definition is seen.
+void PrintPPOutputPPCallbacks::MacroDefined(const Token &MacroNameTok,
+                                            const MacroInfo *MI) {
+  // Only print out macro definitions in -dD mode.
+  if (!DumpDefines ||
+      // Ignore __FILE__ etc.
+      MI->isBuiltinMacro()) return;
+
+  MoveToLine(MI->getDefinitionLoc());
+  PrintMacroDefinition(*MacroNameTok.getIdentifierInfo(), *MI, PP, OS);
+  EmittedMacroOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::MacroUndefined(const Token &MacroNameTok,
+                                              const MacroInfo *MI) {
+  // Only print out macro definitions in -dD mode.
+  if (!DumpDefines) return;
+
+  MoveToLine(MacroNameTok.getLocation());
+  OS << "#undef " << MacroNameTok.getIdentifierInfo()->getName();
+  EmittedMacroOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
+                                             const IdentifierInfo *Kind,
+                                             const std::string &Str) {
+  MoveToLine(Loc);
+  OS << "#pragma comment(" << Kind->getName();
+
+  if (!Str.empty()) {
+    OS << ", \"";
+
+    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+      unsigned char Char = Str[i];
+      if (isprint(Char) && Char != '\\' && Char != '"')
+        OS << (char)Char;
+      else  // Output anything hard as an octal escape.
+        OS << '\\'
+           << (char)('0'+ ((Char >> 6) & 7))
+           << (char)('0'+ ((Char >> 3) & 7))
+           << (char)('0'+ ((Char >> 0) & 7));
+    }
+    OS << '"';
+  }
+
+  OS << ')';
+  EmittedTokensOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::PragmaMessage(SourceLocation Loc,
+                                             StringRef Str) {
+  MoveToLine(Loc);
+  OS << "#pragma message(";
+
+  OS << '"';
+
+  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
+    unsigned char Char = Str[i];
+    if (isprint(Char) && Char != '\\' && Char != '"')
+      OS << (char)Char;
+    else  // Output anything hard as an octal escape.
+      OS << '\\'
+         << (char)('0'+ ((Char >> 6) & 7))
+         << (char)('0'+ ((Char >> 3) & 7))
+         << (char)('0'+ ((Char >> 0) & 7));
+  }
+  OS << '"';
+
+  OS << ')';
+  EmittedTokensOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::
+PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) {
+  MoveToLine(Loc);
+  OS << "#pragma " << Namespace << " diagnostic push";
+  EmittedTokensOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::
+PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) {
+  MoveToLine(Loc);
+  OS << "#pragma " << Namespace << " diagnostic pop";
+  EmittedTokensOnThisLine = true;
+}
+
+void PrintPPOutputPPCallbacks::
+PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
+                 diag::Mapping Map, StringRef Str) {
+  MoveToLine(Loc);
+  OS << "#pragma " << Namespace << " diagnostic ";
+  switch (Map) {
+  case diag::MAP_WARNING:
+    OS << "warning";
+    break;
+  case diag::MAP_ERROR:
+    OS << "error";
+    break;
+  case diag::MAP_IGNORE:
+    OS << "ignored";
+    break;
+  case diag::MAP_FATAL:
+    OS << "fatal";
+    break;
+  }
+  OS << " \"" << Str << '"';
+  EmittedTokensOnThisLine = true;
+}
+
+/// HandleFirstTokOnLine - When emitting a preprocessed file in -E mode, this
+/// is called for the first token on each new line.  If this really is the start
+/// of a new logical line, handle it and return true, otherwise return false.
+/// This may not be the start of a logical line because the "start of line"
+/// marker is set for spelling lines, not expansion ones.
+bool PrintPPOutputPPCallbacks::HandleFirstTokOnLine(Token &Tok) {
+  // Figure out what line we went to and insert the appropriate number of
+  // newline characters.
+  if (!MoveToLine(Tok.getLocation()))
+    return false;
+
+  // Print out space characters so that the first token on a line is
+  // indented for easy reading.
+  unsigned ColNo = SM.getExpansionColumnNumber(Tok.getLocation());
+
+  // This hack prevents stuff like:
+  // #define HASH #
+  // HASH define foo bar
+  // From having the # character end up at column 1, which makes it so it
+  // is not handled as a #define next time through the preprocessor if in
+  // -fpreprocessed mode.
+  if (ColNo <= 1 && Tok.is(tok::hash))
+    OS << ' ';
+
+  // Otherwise, indent the appropriate number of spaces.
+  for (; ColNo > 1; --ColNo)
+    OS << ' ';
+
+  return true;
+}
+
+void PrintPPOutputPPCallbacks::HandleNewlinesInToken(const char *TokStr,
+                                                     unsigned Len) {
+  unsigned NumNewlines = 0;
+  for (; Len; --Len, ++TokStr) {
+    if (*TokStr != '\n' &&
+        *TokStr != '\r')
+      continue;
+
+    ++NumNewlines;
+
+    // If we have \n\r or \r\n, skip both and count as one line.
+    if (Len != 1 &&
+        (TokStr[1] == '\n' || TokStr[1] == '\r') &&
+        TokStr[0] != TokStr[1])
+      ++TokStr, --Len;
+  }
+
+  if (NumNewlines == 0) return;
+
+  CurLine += NumNewlines;
+}
+
+
+namespace {
+struct UnknownPragmaHandler : public PragmaHandler {
+  const char *Prefix;
+  PrintPPOutputPPCallbacks *Callbacks;
+
+  UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks)
+    : Prefix(prefix), Callbacks(callbacks) {}
+  virtual void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+                            Token &PragmaTok) {
+    // Figure out what line we went to and insert the appropriate number of
+    // newline characters.
+    Callbacks->StartNewLineIfNeeded();
+    Callbacks->MoveToLine(PragmaTok.getLocation());
+    Callbacks->OS.write(Prefix, strlen(Prefix));
+    Callbacks->SetEmittedTokensOnThisLine();
+    // Read and print all of the pragma tokens.
+    while (PragmaTok.isNot(tok::eod)) {
+      if (PragmaTok.hasLeadingSpace())
+        Callbacks->OS << ' ';
+      std::string TokSpell = PP.getSpelling(PragmaTok);
+      Callbacks->OS.write(&TokSpell[0], TokSpell.size());
+      PP.LexUnexpandedToken(PragmaTok);
+    }
+    Callbacks->StartNewLineIfNeeded();
+  }
+};
+} // end anonymous namespace
+
+
+static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
+                                    PrintPPOutputPPCallbacks *Callbacks,
+                                    raw_ostream &OS) {
+  char Buffer[256];
+  Token PrevPrevTok, PrevTok;
+  PrevPrevTok.startToken();
+  PrevTok.startToken();
+  while (1) {
+
+    // If this token is at the start of a line, emit newlines if needed.
+    if (Tok.isAtStartOfLine() && Callbacks->HandleFirstTokOnLine(Tok)) {
+      // done.
+    } else if (Tok.hasLeadingSpace() ||
+               // If we haven't emitted a token on this line yet, PrevTok isn't
+               // useful to look at and no concatenation could happen anyway.
+               (Callbacks->hasEmittedTokensOnThisLine() &&
+                // Don't print "-" next to "-", it would form "--".
+                Callbacks->AvoidConcat(PrevPrevTok, PrevTok, Tok))) {
+      OS << ' ';
+    }
+
+    if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
+      OS << II->getName();
+    } else if (Tok.isLiteral() && !Tok.needsCleaning() &&
+               Tok.getLiteralData()) {
+      OS.write(Tok.getLiteralData(), Tok.getLength());
+    } else if (Tok.getLength() < 256) {
+      const char *TokPtr = Buffer;
+      unsigned Len = PP.getSpelling(Tok, TokPtr);
+      OS.write(TokPtr, Len);
+
+      // Tokens that can contain embedded newlines need to adjust our current
+      // line number.
+      if (Tok.getKind() == tok::comment)
+        Callbacks->HandleNewlinesInToken(TokPtr, Len);
+    } else {
+      std::string S = PP.getSpelling(Tok);
+      OS.write(&S[0], S.size());
+
+      // Tokens that can contain embedded newlines need to adjust our current
+      // line number.
+      if (Tok.getKind() == tok::comment)
+        Callbacks->HandleNewlinesInToken(&S[0], S.size());
+    }
+    Callbacks->SetEmittedTokensOnThisLine();
+
+    if (Tok.is(tok::eof)) break;
+
+    PrevPrevTok = PrevTok;
+    PrevTok = Tok;
+    PP.Lex(Tok);
+  }
+}
+
+typedef std::pair<IdentifierInfo*, MacroInfo*> id_macro_pair;
+static int MacroIDCompare(const void* a, const void* b) {
+  const id_macro_pair *LHS = static_cast<const id_macro_pair*>(a);
+  const id_macro_pair *RHS = static_cast<const id_macro_pair*>(b);
+  return LHS->first->getName().compare(RHS->first->getName());
+}
+
+static void DoPrintMacros(Preprocessor &PP, raw_ostream *OS) {
+  // Ignore unknown pragmas.
+  PP.AddPragmaHandler(new EmptyPragmaHandler());
+
+  // -dM mode just scans and ignores all tokens in the files, then dumps out
+  // the macro table at the end.
+  PP.EnterMainSourceFile();
+
+  Token Tok;
+  do PP.Lex(Tok);
+  while (Tok.isNot(tok::eof));
+
+  SmallVector<id_macro_pair, 128>
+    MacrosByID(PP.macro_begin(), PP.macro_end());
+  llvm::array_pod_sort(MacrosByID.begin(), MacrosByID.end(), MacroIDCompare);
+
+  for (unsigned i = 0, e = MacrosByID.size(); i != e; ++i) {
+    MacroInfo &MI = *MacrosByID[i].second;
+    // Ignore computed macros like __LINE__ and friends.
+    if (MI.isBuiltinMacro()) continue;
+
+    PrintMacroDefinition(*MacrosByID[i].first, MI, PP, *OS);
+    *OS << '\n';
+  }
+}
+
+/// DoPrintPreprocessedInput - This implements -E mode.
+///
+void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
+                                     const PreprocessorOutputOptions &Opts) {
+  // Show macros with no output is handled specially.
+  if (!Opts.ShowCPP) {
+    assert(Opts.ShowMacros && "Not yet implemented!");
+    DoPrintMacros(PP, OS);
+    return;
+  }
+
+  // Inform the preprocessor whether we want it to retain comments or not, due
+  // to -C or -CC.
+  PP.SetCommentRetentionState(Opts.ShowComments, Opts.ShowMacroComments);
+
+  PrintPPOutputPPCallbacks *Callbacks =
+      new PrintPPOutputPPCallbacks(PP, *OS, !Opts.ShowLineMarkers,
+                                   Opts.ShowMacros);
+  PP.AddPragmaHandler(new UnknownPragmaHandler("#pragma", Callbacks));
+  PP.AddPragmaHandler("GCC", new UnknownPragmaHandler("#pragma GCC",Callbacks));
+  PP.AddPragmaHandler("clang",
+                      new UnknownPragmaHandler("#pragma clang", Callbacks));
+
+  PP.addPPCallbacks(Callbacks);
+
+  // After we have configured the preprocessor, enter the main file.
+  PP.EnterMainSourceFile();
+
+  // Consume all of the tokens that come from the predefines buffer.  Those
+  // should not be emitted into the output and are guaranteed to be at the
+  // start.
+  const SourceManager &SourceMgr = PP.getSourceManager();
+  Token Tok;
+  do {
+    PP.Lex(Tok);
+    if (Tok.is(tok::eof) || !Tok.getLocation().isFileID())
+      break;
+
+    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
+    if (PLoc.isInvalid())
+      break;
+
+    if (strcmp(PLoc.getFilename(), "<built-in>"))
+      break;
+  } while (true);
+
+  // Read all the preprocessed tokens, printing them out to the stream.
+  PrintPreprocessedTokens(PP, Tok, Callbacks, *OS);
+  *OS << '\n';
+}
diff --git a/clang/lib/Frontend/SerializedDiagnosticPrinter.cpp b/clang/lib/Frontend/SerializedDiagnosticPrinter.cpp
new file mode 100644
index 0000000..7bf8742
--- /dev/null
+++ b/clang/lib/Frontend/SerializedDiagnosticPrinter.cpp
@@ -0,0 +1,592 @@
+//===--- SerializedDiagnosticPrinter.cpp - Serializer for diagnostics -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <vector>
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/DenseSet.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/Version.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Frontend/SerializedDiagnosticPrinter.h"
+#include "clang/Frontend/DiagnosticRenderer.h"
+
+using namespace clang;
+using namespace clang::serialized_diags;
+
+namespace {
+  
+class AbbreviationMap {
+  llvm::DenseMap<unsigned, unsigned> Abbrevs;
+public:
+  AbbreviationMap() {}
+  
+  void set(unsigned recordID, unsigned abbrevID) {
+    assert(Abbrevs.find(recordID) == Abbrevs.end() 
+           && "Abbreviation already set.");
+    Abbrevs[recordID] = abbrevID;
+  }
+  
+  unsigned get(unsigned recordID) {
+    assert(Abbrevs.find(recordID) != Abbrevs.end() &&
+           "Abbreviation not set.");
+    return Abbrevs[recordID];
+  }
+};
+ 
+typedef llvm::SmallVector<uint64_t, 64> RecordData;
+typedef llvm::SmallVectorImpl<uint64_t> RecordDataImpl;
+
+class SDiagsWriter;
+  
+class SDiagsRenderer : public DiagnosticNoteRenderer {
+  SDiagsWriter &Writer;
+  RecordData &Record;
+public:
+  SDiagsRenderer(SDiagsWriter &Writer, RecordData &Record,
+                 const SourceManager &SM,
+                 const LangOptions &LangOpts,
+                 const DiagnosticOptions &DiagOpts)
+    : DiagnosticNoteRenderer(SM, LangOpts, DiagOpts),
+      Writer(Writer), Record(Record){}
+
+  virtual ~SDiagsRenderer() {}
+  
+protected:
+  virtual void emitDiagnosticMessage(SourceLocation Loc,
+                                     PresumedLoc PLoc,
+                                     DiagnosticsEngine::Level Level,
+                                     StringRef Message,
+                                     ArrayRef<CharSourceRange> Ranges,
+                                     DiagOrStoredDiag D);
+  
+  virtual void emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
+                                 DiagnosticsEngine::Level Level,
+                                 ArrayRef<CharSourceRange> Ranges) {}
+  
+  void emitNote(SourceLocation Loc, StringRef Message);
+  
+  virtual void emitCodeContext(SourceLocation Loc,
+                               DiagnosticsEngine::Level Level,
+                               SmallVectorImpl<CharSourceRange>& Ranges,
+                               ArrayRef<FixItHint> Hints);
+  
+  virtual void beginDiagnostic(DiagOrStoredDiag D,
+                               DiagnosticsEngine::Level Level);
+  virtual void endDiagnostic(DiagOrStoredDiag D,
+                             DiagnosticsEngine::Level Level);
+};
+  
+class SDiagsWriter : public DiagnosticConsumer {
+  friend class SDiagsRenderer;
+public:  
+  explicit SDiagsWriter(llvm::raw_ostream *os, const DiagnosticOptions &diags) 
+    : LangOpts(0), DiagOpts(diags),
+      Stream(Buffer), OS(os), inNonNoteDiagnostic(false)
+  { 
+    EmitPreamble();
+  }
+  
+  ~SDiagsWriter() {}
+  
+  void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
+                        const Diagnostic &Info);
+  
+  void BeginSourceFile(const LangOptions &LO,
+                       const Preprocessor *PP) {
+    LangOpts = &LO;
+  }
+
+  virtual void finish();
+
+  DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
+    // It makes no sense to clone this.
+    return 0;
+  }
+
+private:
+  /// \brief Emit the preamble for the serialized diagnostics.
+  void EmitPreamble();
+  
+  /// \brief Emit the BLOCKINFO block.
+  void EmitBlockInfoBlock();
+
+  /// \brief Emit the META data block.
+  void EmitMetaBlock();
+  
+  /// \brief Emit a record for a CharSourceRange.
+  void EmitCharSourceRange(CharSourceRange R, const SourceManager &SM);
+  
+  /// \brief Emit the string information for the category.
+  unsigned getEmitCategory(unsigned category = 0);
+  
+  /// \brief Emit the string information for diagnostic flags.
+  unsigned getEmitDiagnosticFlag(DiagnosticsEngine::Level DiagLevel,
+                                 unsigned DiagID = 0);
+  
+  /// \brief Emit (lazily) the file string and retrieved the file identifier.
+  unsigned getEmitFile(const char *Filename);
+
+  /// \brief Add SourceLocation information the specified record.  
+  void AddLocToRecord(SourceLocation Loc, const SourceManager &SM,
+                      PresumedLoc PLoc, RecordDataImpl &Record,
+                      unsigned TokSize = 0);
+
+  /// \brief Add SourceLocation information the specified record.
+  void AddLocToRecord(SourceLocation Loc, RecordDataImpl &Record,
+                      const SourceManager &SM,
+                      unsigned TokSize = 0) {
+    AddLocToRecord(Loc, SM, SM.getPresumedLoc(Loc), Record, TokSize);
+  }
+
+  /// \brief Add CharSourceRange information the specified record.
+  void AddCharSourceRangeToRecord(CharSourceRange R, RecordDataImpl &Record,
+                                  const SourceManager &SM);
+
+  /// \brief The version of the diagnostics file.
+  enum { Version = 1 };
+
+  const LangOptions *LangOpts;
+  const DiagnosticOptions &DiagOpts;
+  
+  /// \brief The byte buffer for the serialized content.
+  SmallString<1024> Buffer;
+
+  /// \brief The BitStreamWriter for the serialized diagnostics.
+  llvm::BitstreamWriter Stream;
+
+  /// \brief The name of the diagnostics file.
+  OwningPtr<llvm::raw_ostream> OS;
+  
+  /// \brief The set of constructed record abbreviations.
+  AbbreviationMap Abbrevs;
+
+  /// \brief A utility buffer for constructing record content.
+  RecordData Record;
+
+  /// \brief A text buffer for rendering diagnostic text.
+  SmallString<256> diagBuf;
+  
+  /// \brief The collection of diagnostic categories used.
+  llvm::DenseSet<unsigned> Categories;
+  
+  /// \brief The collection of files used.
+  llvm::DenseMap<const char *, unsigned> Files;
+
+  typedef llvm::DenseMap<const void *, std::pair<unsigned, llvm::StringRef> > 
+          DiagFlagsTy;
+
+  /// \brief Map for uniquing strings.
+  DiagFlagsTy DiagFlags;
+  
+  /// \brief Flag indicating whether or not we are in the process of
+  /// emitting a non-note diagnostic.
+  bool inNonNoteDiagnostic;
+};
+} // end anonymous namespace
+
+namespace clang {
+namespace serialized_diags {
+DiagnosticConsumer *create(llvm::raw_ostream *OS,
+                           const DiagnosticOptions &diags) {
+  return new SDiagsWriter(OS, diags);
+}
+} // end namespace serialized_diags
+} // end namespace clang
+
+//===----------------------------------------------------------------------===//
+// Serialization methods.
+//===----------------------------------------------------------------------===//
+
+/// \brief Emits a block ID in the BLOCKINFO block.
+static void EmitBlockID(unsigned ID, const char *Name,
+                        llvm::BitstreamWriter &Stream,
+                        RecordDataImpl &Record) {
+  Record.clear();
+  Record.push_back(ID);
+  Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
+  
+  // Emit the block name if present.
+  if (Name == 0 || Name[0] == 0)
+    return;
+
+  Record.clear();
+
+  while (*Name)
+    Record.push_back(*Name++);
+
+  Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
+}
+
+/// \brief Emits a record ID in the BLOCKINFO block.
+static void EmitRecordID(unsigned ID, const char *Name,
+                         llvm::BitstreamWriter &Stream,
+                         RecordDataImpl &Record){
+  Record.clear();
+  Record.push_back(ID);
+
+  while (*Name)
+    Record.push_back(*Name++);
+
+  Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
+}
+
+void SDiagsWriter::AddLocToRecord(SourceLocation Loc,
+                                  const SourceManager &SM,
+                                  PresumedLoc PLoc,
+                                  RecordDataImpl &Record,
+                                  unsigned TokSize) {
+  if (PLoc.isInvalid()) {
+    // Emit a "sentinel" location.
+    Record.push_back((unsigned)0); // File.
+    Record.push_back((unsigned)0); // Line.
+    Record.push_back((unsigned)0); // Column.
+    Record.push_back((unsigned)0); // Offset.
+    return;
+  }
+
+  Record.push_back(getEmitFile(PLoc.getFilename()));
+  Record.push_back(PLoc.getLine());
+  Record.push_back(PLoc.getColumn()+TokSize);
+  Record.push_back(SM.getFileOffset(Loc));
+}
+
+void SDiagsWriter::AddCharSourceRangeToRecord(CharSourceRange Range,
+                                              RecordDataImpl &Record,
+                                              const SourceManager &SM) {
+  AddLocToRecord(Range.getBegin(), Record, SM);
+  unsigned TokSize = 0;
+  if (Range.isTokenRange())
+    TokSize = Lexer::MeasureTokenLength(Range.getEnd(),
+                                        SM, *LangOpts);
+  
+  AddLocToRecord(Range.getEnd(), Record, SM, TokSize);
+}
+
+unsigned SDiagsWriter::getEmitFile(const char *FileName){
+  if (!FileName)
+    return 0;
+  
+  unsigned &entry = Files[FileName];
+  if (entry)
+    return entry;
+  
+  // Lazily generate the record for the file.
+  entry = Files.size();
+  RecordData Record;
+  Record.push_back(RECORD_FILENAME);
+  Record.push_back(entry);
+  Record.push_back(0); // For legacy.
+  Record.push_back(0); // For legacy.
+  StringRef Name(FileName);
+  Record.push_back(Name.size());
+  Stream.EmitRecordWithBlob(Abbrevs.get(RECORD_FILENAME), Record, Name);
+
+  return entry;
+}
+
+void SDiagsWriter::EmitCharSourceRange(CharSourceRange R,
+                                       const SourceManager &SM) {
+  Record.clear();
+  Record.push_back(RECORD_SOURCE_RANGE);
+  AddCharSourceRangeToRecord(R, Record, SM);
+  Stream.EmitRecordWithAbbrev(Abbrevs.get(RECORD_SOURCE_RANGE), Record);
+}
+
+/// \brief Emits the preamble of the diagnostics file.
+void SDiagsWriter::EmitPreamble() {
+  // Emit the file header.
+  Stream.Emit((unsigned)'D', 8);
+  Stream.Emit((unsigned)'I', 8);
+  Stream.Emit((unsigned)'A', 8);
+  Stream.Emit((unsigned)'G', 8);
+
+  EmitBlockInfoBlock();
+  EmitMetaBlock();
+}
+
+static void AddSourceLocationAbbrev(llvm::BitCodeAbbrev *Abbrev) {
+  using namespace llvm;
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // File ID.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Line.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Column.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Offset;
+}
+
+static void AddRangeLocationAbbrev(llvm::BitCodeAbbrev *Abbrev) {
+  AddSourceLocationAbbrev(Abbrev);
+  AddSourceLocationAbbrev(Abbrev);  
+}
+
+void SDiagsWriter::EmitBlockInfoBlock() {
+  Stream.EnterBlockInfoBlock(3);
+
+  using namespace llvm;
+
+  // ==---------------------------------------------------------------------==//
+  // The subsequent records and Abbrevs are for the "Meta" block.
+  // ==---------------------------------------------------------------------==//
+
+  EmitBlockID(BLOCK_META, "Meta", Stream, Record);
+  EmitRecordID(RECORD_VERSION, "Version", Stream, Record);
+  BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_VERSION));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
+  Abbrevs.set(RECORD_VERSION, Stream.EmitBlockInfoAbbrev(BLOCK_META, Abbrev));
+
+  // ==---------------------------------------------------------------------==//
+  // The subsequent records and Abbrevs are for the "Diagnostic" block.
+  // ==---------------------------------------------------------------------==//
+
+  EmitBlockID(BLOCK_DIAG, "Diag", Stream, Record);
+  EmitRecordID(RECORD_DIAG, "DiagInfo", Stream, Record);
+  EmitRecordID(RECORD_SOURCE_RANGE, "SrcRange", Stream, Record);
+  EmitRecordID(RECORD_CATEGORY, "CatName", Stream, Record);
+  EmitRecordID(RECORD_DIAG_FLAG, "DiagFlag", Stream, Record);
+  EmitRecordID(RECORD_FILENAME, "FileName", Stream, Record);
+  EmitRecordID(RECORD_FIXIT, "FixIt", Stream, Record);
+
+  // Emit abbreviation for RECORD_DIAG.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_DIAG));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // Diag level.
+  AddSourceLocationAbbrev(Abbrev);
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Category.  
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped Diag ID.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Diagnostc text.
+  Abbrevs.set(RECORD_DIAG, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
+  
+  // Emit abbrevation for RECORD_CATEGORY.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_CATEGORY));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Category ID.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));  // Text size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // Category text.
+  Abbrevs.set(RECORD_CATEGORY, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
+
+  // Emit abbrevation for RECORD_SOURCE_RANGE.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_SOURCE_RANGE));
+  AddRangeLocationAbbrev(Abbrev);
+  Abbrevs.set(RECORD_SOURCE_RANGE,
+              Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
+  
+  // Emit the abbreviation for RECORD_DIAG_FLAG.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_DIAG_FLAG));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped Diag ID.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Flag name text.
+  Abbrevs.set(RECORD_DIAG_FLAG, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
+                                                           Abbrev));
+  
+  // Emit the abbreviation for RECORD_FILENAME.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_FILENAME));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped file ID.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Modifcation time.  
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name text.
+  Abbrevs.set(RECORD_FILENAME, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
+                                                          Abbrev));
+  
+  // Emit the abbreviation for RECORD_FIXIT.
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(RECORD_FIXIT));
+  AddRangeLocationAbbrev(Abbrev);
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // FixIt text.
+  Abbrevs.set(RECORD_FIXIT, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
+                                                       Abbrev));
+
+  Stream.ExitBlock();
+}
+
+void SDiagsWriter::EmitMetaBlock() {
+  Stream.EnterSubblock(BLOCK_META, 3);
+  Record.clear();
+  Record.push_back(RECORD_VERSION);
+  Record.push_back(Version);
+  Stream.EmitRecordWithAbbrev(Abbrevs.get(RECORD_VERSION), Record);  
+  Stream.ExitBlock();
+}
+
+unsigned SDiagsWriter::getEmitCategory(unsigned int category) {
+  if (Categories.count(category))
+    return category;
+  
+  Categories.insert(category);
+  
+  // We use a local version of 'Record' so that we can be generating
+  // another record when we lazily generate one for the category entry.
+  RecordData Record;
+  Record.push_back(RECORD_CATEGORY);
+  Record.push_back(category);
+  StringRef catName = DiagnosticIDs::getCategoryNameFromID(category);
+  Record.push_back(catName.size());
+  Stream.EmitRecordWithBlob(Abbrevs.get(RECORD_CATEGORY), Record, catName);
+  
+  return category;
+}
+
+unsigned SDiagsWriter::getEmitDiagnosticFlag(DiagnosticsEngine::Level DiagLevel,
+                                             unsigned DiagID) {
+  if (DiagLevel == DiagnosticsEngine::Note)
+    return 0; // No flag for notes.
+  
+  StringRef FlagName = DiagnosticIDs::getWarningOptionForDiag(DiagID);
+  if (FlagName.empty())
+    return 0;
+
+  // Here we assume that FlagName points to static data whose pointer
+  // value is fixed.  This allows us to unique by diagnostic groups.
+  const void *data = FlagName.data();
+  std::pair<unsigned, StringRef> &entry = DiagFlags[data];
+  if (entry.first == 0) {
+    entry.first = DiagFlags.size();
+    entry.second = FlagName;
+    
+    // Lazily emit the string in a separate record.
+    RecordData Record;
+    Record.push_back(RECORD_DIAG_FLAG);
+    Record.push_back(entry.first);
+    Record.push_back(FlagName.size());
+    Stream.EmitRecordWithBlob(Abbrevs.get(RECORD_DIAG_FLAG),
+                              Record, FlagName);    
+  }
+
+  return entry.first;
+}
+
+void SDiagsWriter::HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
+                                    const Diagnostic &Info) {
+  if (DiagLevel != DiagnosticsEngine::Note) {
+    if (inNonNoteDiagnostic) {
+      // We have encountered a non-note diagnostic.  Finish up the previous
+      // diagnostic block before starting a new one.
+      Stream.ExitBlock();
+    }
+    inNonNoteDiagnostic = true;
+  }
+
+  // Compute the diagnostic text.
+  diagBuf.clear();   
+  Info.FormatDiagnostic(diagBuf);
+
+  SourceManager &SM = Info.getSourceManager();
+  SDiagsRenderer Renderer(*this, Record, SM, *LangOpts, DiagOpts);
+  Renderer.emitDiagnostic(Info.getLocation(), DiagLevel,
+                          diagBuf.str(),
+                          Info.getRanges(),
+                          llvm::makeArrayRef(Info.getFixItHints(),
+                                             Info.getNumFixItHints()),
+                          &Info);
+}
+
+void
+SDiagsRenderer::emitDiagnosticMessage(SourceLocation Loc,
+                                      PresumedLoc PLoc,
+                                      DiagnosticsEngine::Level Level,
+                                      StringRef Message,
+                                      ArrayRef<clang::CharSourceRange> Ranges,
+                                      DiagOrStoredDiag D) {
+  // Emit the RECORD_DIAG record.
+  Writer.Record.clear();
+  Writer.Record.push_back(RECORD_DIAG);
+  Writer.Record.push_back(Level);
+  Writer.AddLocToRecord(Loc, SM, PLoc, Record);
+
+  if (const Diagnostic *Info = D.dyn_cast<const Diagnostic*>()) {
+    // Emit the category string lazily and get the category ID.
+    unsigned DiagID = DiagnosticIDs::getCategoryNumberForDiag(Info->getID());
+    Writer.Record.push_back(Writer.getEmitCategory(DiagID));
+    // Emit the diagnostic flag string lazily and get the mapped ID.
+    Writer.Record.push_back(Writer.getEmitDiagnosticFlag(Level, Info->getID()));
+  }
+  else {
+    Writer.Record.push_back(Writer.getEmitCategory());
+    Writer.Record.push_back(Writer.getEmitDiagnosticFlag(Level));
+  }
+
+  Writer.Record.push_back(Message.size());
+  Writer.Stream.EmitRecordWithBlob(Writer.Abbrevs.get(RECORD_DIAG),
+                                   Writer.Record, Message);
+}
+
+void SDiagsRenderer::beginDiagnostic(DiagOrStoredDiag D,
+                                     DiagnosticsEngine::Level Level) {
+  Writer.Stream.EnterSubblock(BLOCK_DIAG, 4);  
+}
+
+void SDiagsRenderer::endDiagnostic(DiagOrStoredDiag D,
+                                   DiagnosticsEngine::Level Level) {
+  if (D && Level != DiagnosticsEngine::Note)
+    return;
+  Writer.Stream.ExitBlock();
+}
+
+void SDiagsRenderer::emitCodeContext(SourceLocation Loc,
+                                     DiagnosticsEngine::Level Level,
+                                     SmallVectorImpl<CharSourceRange> &Ranges,
+                                     ArrayRef<FixItHint> Hints) {  
+  // Emit Source Ranges.
+  for (ArrayRef<CharSourceRange>::iterator it=Ranges.begin(), ei=Ranges.end();
+       it != ei; ++it) {
+    if (it->isValid())
+      Writer.EmitCharSourceRange(*it, SM);
+  }
+  
+  // Emit FixIts.
+  for (ArrayRef<FixItHint>::iterator it = Hints.begin(), et = Hints.end();
+       it != et; ++it) {
+    const FixItHint &fix = *it;
+    if (fix.isNull())
+      continue;
+    Writer.Record.clear();
+    Writer.Record.push_back(RECORD_FIXIT);
+    Writer.AddCharSourceRangeToRecord(fix.RemoveRange, Record, SM);
+    Writer.Record.push_back(fix.CodeToInsert.size());
+    Writer.Stream.EmitRecordWithBlob(Writer.Abbrevs.get(RECORD_FIXIT), Record,
+                                     fix.CodeToInsert);    
+  }
+}
+
+void SDiagsRenderer::emitNote(SourceLocation Loc, StringRef Message) {
+  Writer.Stream.EnterSubblock(BLOCK_DIAG, 4);
+  RecordData Record;
+  Record.push_back(RECORD_DIAG);
+  Record.push_back(DiagnosticsEngine::Note);
+  Writer.AddLocToRecord(Loc, Record, SM);
+  Record.push_back(Writer.getEmitCategory());
+  Record.push_back(Writer.getEmitDiagnosticFlag(DiagnosticsEngine::Note));
+  Record.push_back(Message.size());
+  Writer.Stream.EmitRecordWithBlob(Writer.Abbrevs.get(RECORD_DIAG),
+                                   Record, Message);
+  Writer.Stream.ExitBlock();
+}
+
+void SDiagsWriter::finish() {
+  if (inNonNoteDiagnostic) {
+    // Finish off any diagnostics we were in the process of emitting.
+    Stream.ExitBlock();
+    inNonNoteDiagnostic = false;
+  }
+
+  // Write the generated bitstream to "Out".
+  OS->write((char *)&Buffer.front(), Buffer.size());
+  OS->flush();
+  
+  OS.reset(0);
+}
+
diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
new file mode 100644
index 0000000..65fb1ae
--- /dev/null
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -0,0 +1,1164 @@
+//===--- TextDiagnostic.cpp - Text Diagnostic Pretty-Printing -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/TextDiagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/ConvertUTF.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Locale.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include <algorithm>
+
+using namespace clang;
+
+static const enum raw_ostream::Colors noteColor =
+  raw_ostream::BLACK;
+static const enum raw_ostream::Colors fixitColor =
+  raw_ostream::GREEN;
+static const enum raw_ostream::Colors caretColor =
+  raw_ostream::GREEN;
+static const enum raw_ostream::Colors warningColor =
+  raw_ostream::MAGENTA;
+static const enum raw_ostream::Colors errorColor = raw_ostream::RED;
+static const enum raw_ostream::Colors fatalColor = raw_ostream::RED;
+// Used for changing only the bold attribute.
+static const enum raw_ostream::Colors savedColor =
+  raw_ostream::SAVEDCOLOR;
+
+/// \brief Number of spaces to indent when word-wrapping.
+const unsigned WordWrapIndentation = 6;
+
+int bytesSincePreviousTabOrLineBegin(StringRef SourceLine, size_t i) {
+  int bytes = 0;
+  while (0<i) {
+    if (SourceLine[--i]=='\t')
+      break;
+    ++bytes;
+  }
+  return bytes;
+}
+
+/// \brief returns a printable representation of first item from input range
+///
+/// This function returns a printable representation of the next item in a line
+///  of source. If the next byte begins a valid and printable character, that
+///  character is returned along with 'true'.
+///
+/// Otherwise, if the next byte begins a valid, but unprintable character, a
+///  printable, escaped representation of the character is returned, along with
+///  'false'. Otherwise a printable, escaped representation of the next byte
+///  is returned along with 'false'.
+///
+/// \note The index is updated to be used with a subsequent call to
+///        printableTextForNextCharacter.
+///
+/// \param SourceLine The line of source
+/// \param i Pointer to byte index,
+/// \param TabStop used to expand tabs
+/// \return pair(printable text, 'true' iff original text was printable)
+///
+std::pair<SmallString<16>,bool>
+printableTextForNextCharacter(StringRef SourceLine, size_t *i,
+                              unsigned TabStop) {
+  assert(i && "i must not be null");
+  assert(*i<SourceLine.size() && "must point to a valid index");
+  
+  if (SourceLine[*i]=='\t') {
+    assert(0 < TabStop && TabStop <= DiagnosticOptions::MaxTabStop &&
+           "Invalid -ftabstop value");
+    unsigned col = bytesSincePreviousTabOrLineBegin(SourceLine, *i);
+    unsigned NumSpaces = TabStop - col%TabStop;
+    assert(0 < NumSpaces && NumSpaces <= TabStop
+           && "Invalid computation of space amt");
+    ++(*i);
+
+    SmallString<16> expandedTab;
+    expandedTab.assign(NumSpaces, ' ');
+    return std::make_pair(expandedTab, true);
+  }
+
+  // FIXME: this data is copied from the private implementation of ConvertUTF.h
+  static const char trailingBytesForUTF8[256] = {
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
+  };
+
+  unsigned char const *begin, *end;
+  begin = reinterpret_cast<unsigned char const *>(&*(SourceLine.begin() + *i));
+  end = begin + SourceLine.size();
+  
+  if (isLegalUTF8Sequence(begin, end)) {
+    UTF32 c;
+    UTF32 *cptr = &c;
+    unsigned char const *original_begin = begin;
+    char trailingBytes = trailingBytesForUTF8[(unsigned char)SourceLine[*i]];
+    unsigned char const *cp_end = begin+trailingBytes+1;
+
+    ConversionResult res = ConvertUTF8toUTF32(&begin, cp_end, &cptr, cptr+1,
+                                              strictConversion);
+    (void)res;
+    assert(conversionOK==res);
+    assert(0 < begin-original_begin
+           && "we must be further along in the string now");
+    *i += begin-original_begin;
+
+    if (!llvm::sys::locale::isPrint(c)) {
+      // If next character is valid UTF-8, but not printable
+      SmallString<16> expandedCP("<U+>");
+      while (c) {
+        expandedCP.insert(expandedCP.begin()+3, llvm::hexdigit(c%16));
+        c/=16;
+      }
+      while (expandedCP.size() < 8)
+        expandedCP.insert(expandedCP.begin()+3, llvm::hexdigit(0));
+      return std::make_pair(expandedCP, false);
+    }
+
+    // If next character is valid UTF-8, and printable
+    return std::make_pair(SmallString<16>(original_begin, cp_end), true);
+
+  }
+
+  // If next byte is not valid UTF-8 (and therefore not printable)
+  SmallString<16> expandedByte("<XX>");
+  unsigned char byte = SourceLine[*i];
+  expandedByte[1] = llvm::hexdigit(byte / 16);
+  expandedByte[2] = llvm::hexdigit(byte % 16);
+  ++(*i);
+  return std::make_pair(expandedByte, false);
+}
+
+void expandTabs(std::string &SourceLine, unsigned TabStop) {
+  size_t i = SourceLine.size();
+  while (i>0) {
+    i--;
+    if (SourceLine[i]!='\t')
+      continue;
+    size_t tmp_i = i;
+    std::pair<SmallString<16>,bool> res
+      = printableTextForNextCharacter(SourceLine, &tmp_i, TabStop);
+    SourceLine.replace(i, 1, res.first.c_str());
+  }
+}
+
+/// This function takes a raw source line and produces a mapping from the bytes
+///  of the printable representation of the line to the columns those printable
+///  characters will appear at (numbering the first column as 0).
+///
+/// If a byte 'i' corresponds to muliple columns (e.g. the byte contains a tab
+///  character) then the the array will map that byte to the first column the
+///  tab appears at and the next value in the map will have been incremented
+///  more than once.
+///
+/// If a byte is the first in a sequence of bytes that together map to a single
+///  entity in the output, then the array will map that byte to the appropriate
+///  column while the subsequent bytes will be -1.
+///
+/// The last element in the array does not correspond to any byte in the input
+///  and instead is the number of columns needed to display the source
+///
+/// example: (given a tabstop of 8)
+///
+///    "a \t \u3042" -> {0,1,2,8,9,-1,-1,11}
+///
+///  (\u3042 is represented in UTF-8 by three bytes and takes two columns to
+///   display)
+void byteToColumn(StringRef SourceLine, unsigned TabStop,
+                         SmallVectorImpl<int> &out) {
+  out.clear();
+
+  if (SourceLine.empty()) {
+    out.resize(1u,0);
+    return;
+  }
+  
+  out.resize(SourceLine.size()+1, -1);
+
+  int columns = 0;
+  size_t i = 0;
+  while (i<SourceLine.size()) {
+    out[i] = columns;
+    std::pair<SmallString<16>,bool> res
+      = printableTextForNextCharacter(SourceLine, &i, TabStop);
+    columns += llvm::sys::locale::columnWidth(res.first);
+  }
+  out.back() = columns;
+}
+
+/// This function takes a raw source line and produces a mapping from columns
+///  to the byte of the source line that produced the character displaying at
+///  that column. This is the inverse of the mapping produced by byteToColumn()
+///
+/// The last element in the array is the number of bytes in the source string
+///
+/// example: (given a tabstop of 8)
+///
+///    "a \t \u3042" -> {0,1,2,-1,-1,-1,-1,-1,3,4,-1,7}
+///
+///  (\u3042 is represented in UTF-8 by three bytes and takes two columns to
+///   display)
+void columnToByte(StringRef SourceLine, unsigned TabStop,
+                         SmallVectorImpl<int> &out) {
+  out.clear();
+
+  if (SourceLine.empty()) {
+    out.resize(1u, 0);
+    return;
+  }
+
+  int columns = 0;
+  size_t i = 0;
+  while (i<SourceLine.size()) {
+    out.resize(columns+1, -1);
+    out.back() = i;
+    std::pair<SmallString<16>,bool> res
+      = printableTextForNextCharacter(SourceLine, &i, TabStop);
+    columns += llvm::sys::locale::columnWidth(res.first);
+  }
+  out.resize(columns+1, -1);
+  out.back() = i;
+}
+
+struct SourceColumnMap {
+  SourceColumnMap(StringRef SourceLine, unsigned TabStop)
+  : m_SourceLine(SourceLine) {
+    
+    ::byteToColumn(SourceLine, TabStop, m_byteToColumn);
+    ::columnToByte(SourceLine, TabStop, m_columnToByte);
+    
+    assert(m_byteToColumn.size()==SourceLine.size()+1);
+    assert(0 < m_byteToColumn.size() && 0 < m_columnToByte.size());
+    assert(m_byteToColumn.size()
+           == static_cast<unsigned>(m_columnToByte.back()+1));
+    assert(static_cast<unsigned>(m_byteToColumn.back()+1)
+           == m_columnToByte.size());
+  }
+  int columns() const { return m_byteToColumn.back(); }
+  int bytes() const { return m_columnToByte.back(); }
+  int byteToColumn(int n) const {
+    assert(0<=n && n<static_cast<int>(m_byteToColumn.size()));
+    return m_byteToColumn[n];
+  }
+  int columnToByte(int n) const {
+    assert(0<=n && n<static_cast<int>(m_columnToByte.size()));
+    return m_columnToByte[n];
+  }
+  StringRef getSourceLine() const {
+    return m_SourceLine;
+  }
+  
+private:
+  const std::string m_SourceLine;
+  SmallVector<int,200> m_byteToColumn;
+  SmallVector<int,200> m_columnToByte;
+};
+
+// used in assert in selectInterestingSourceRegion()
+namespace {
+struct char_out_of_range {
+  const char lower,upper;
+  char_out_of_range(char lower, char upper) :
+    lower(lower), upper(upper) {}
+  bool operator()(char c) { return c < lower || upper < c; }
+};
+}
+
+/// \brief When the source code line we want to print is too long for
+/// the terminal, select the "interesting" region.
+static void selectInterestingSourceRegion(std::string &SourceLine,
+                                          std::string &CaretLine,
+                                          std::string &FixItInsertionLine,
+                                          unsigned Columns,
+                                          const SourceColumnMap &map) {
+  unsigned MaxColumns = std::max<unsigned>(map.columns(),
+                                           std::max(CaretLine.size(),
+                                                    FixItInsertionLine.size()));
+  // if the number of columns is less than the desired number we're done
+  if (MaxColumns <= Columns)
+    return;
+
+  // no special characters allowed in CaretLine or FixItInsertionLine
+  assert(CaretLine.end() ==
+         std::find_if(CaretLine.begin(), CaretLine.end(),
+         char_out_of_range(' ','~')));
+  assert(FixItInsertionLine.end() ==
+         std::find_if(FixItInsertionLine.begin(), FixItInsertionLine.end(),
+         char_out_of_range(' ','~')));
+
+  // Find the slice that we need to display the full caret line
+  // correctly.
+  unsigned CaretStart = 0, CaretEnd = CaretLine.size();
+  for (; CaretStart != CaretEnd; ++CaretStart)
+    if (!isspace(CaretLine[CaretStart]))
+      break;
+
+  for (; CaretEnd != CaretStart; --CaretEnd)
+    if (!isspace(CaretLine[CaretEnd - 1]))
+      break;
+
+  // caret has already been inserted into CaretLine so the above whitespace
+  // check is guaranteed to include the caret
+
+  // If we have a fix-it line, make sure the slice includes all of the
+  // fix-it information.
+  if (!FixItInsertionLine.empty()) {
+    unsigned FixItStart = 0, FixItEnd = FixItInsertionLine.size();
+    for (; FixItStart != FixItEnd; ++FixItStart)
+      if (!isspace(FixItInsertionLine[FixItStart]))
+        break;
+
+    for (; FixItEnd != FixItStart; --FixItEnd)
+      if (!isspace(FixItInsertionLine[FixItEnd - 1]))
+        break;
+
+    CaretStart = std::min(FixItStart, CaretStart);
+    CaretEnd = std::max(FixItEnd, CaretEnd);
+  }
+
+  // CaretLine[CaretStart, CaretEnd) contains all of the interesting
+  // parts of the caret line. While this slice is smaller than the
+  // number of columns we have, try to grow the slice to encompass
+  // more context.
+
+  unsigned SourceStart = map.columnToByte(std::min<unsigned>(CaretStart,
+                                                             map.columns()));
+  unsigned SourceEnd = map.columnToByte(std::min<unsigned>(CaretEnd,
+                                                           map.columns()));
+
+  unsigned CaretColumnsOutsideSource = CaretEnd-CaretStart
+    - (map.byteToColumn(SourceEnd)-map.byteToColumn(SourceStart));
+
+  char const *front_ellipse = "  ...";
+  char const *front_space   = "     ";
+  char const *back_ellipse = "...";
+  unsigned ellipses_space = strlen(front_ellipse) + strlen(back_ellipse);
+
+  unsigned TargetColumns = Columns;
+  // Give us extra room for the ellipses
+  //  and any of the caret line that extends past the source
+  if (TargetColumns > ellipses_space+CaretColumnsOutsideSource)
+    TargetColumns -= ellipses_space+CaretColumnsOutsideSource;
+
+  while (SourceStart>0 || SourceEnd<SourceLine.size()) {
+    bool ExpandedRegion = false;
+
+    if (SourceStart>0) {
+      unsigned NewStart = SourceStart-1;
+
+      // Skip over any whitespace we see here; we're looking for
+      // another bit of interesting text.
+      while (NewStart &&
+             (map.byteToColumn(NewStart)==-1 || isspace(SourceLine[NewStart])))
+        --NewStart;
+
+      // Skip over this bit of "interesting" text.
+      while (NewStart &&
+             (map.byteToColumn(NewStart)!=-1 && !isspace(SourceLine[NewStart])))
+        --NewStart;
+
+      // Move up to the non-whitespace character we just saw.
+      if (NewStart)
+        ++NewStart;
+
+      unsigned NewColumns = map.byteToColumn(SourceEnd) -
+                              map.byteToColumn(NewStart);
+      if (NewColumns <= TargetColumns) {
+        SourceStart = NewStart;
+        ExpandedRegion = true;
+      }
+    }
+
+    if (SourceEnd<SourceLine.size()) {
+      unsigned NewEnd = SourceEnd+1;
+
+      // Skip over any whitespace we see here; we're looking for
+      // another bit of interesting text.
+      while (NewEnd<SourceLine.size() &&
+             (map.byteToColumn(NewEnd)==-1 || isspace(SourceLine[NewEnd])))
+        ++NewEnd;
+
+      // Skip over this bit of "interesting" text.
+      while (NewEnd<SourceLine.size() &&
+             (map.byteToColumn(NewEnd)!=-1 && !isspace(SourceLine[NewEnd])))
+        ++NewEnd;
+
+      unsigned NewColumns = map.byteToColumn(NewEnd) -
+                              map.byteToColumn(SourceStart);
+      if (NewColumns <= TargetColumns) {
+        SourceEnd = NewEnd;
+        ExpandedRegion = true;
+      }
+    }
+
+    if (!ExpandedRegion)
+      break;
+  }
+
+  CaretStart = map.byteToColumn(SourceStart);
+  CaretEnd = map.byteToColumn(SourceEnd) + CaretColumnsOutsideSource;
+
+  // [CaretStart, CaretEnd) is the slice we want. Update the various
+  // output lines to show only this slice, with two-space padding
+  // before the lines so that it looks nicer.
+
+  assert(CaretStart!=(unsigned)-1 && CaretEnd!=(unsigned)-1 &&
+         SourceStart!=(unsigned)-1 && SourceEnd!=(unsigned)-1);
+  assert(SourceStart <= SourceEnd);
+  assert(CaretStart <= CaretEnd);
+
+  unsigned BackColumnsRemoved
+    = map.byteToColumn(SourceLine.size())-map.byteToColumn(SourceEnd);
+  unsigned FrontColumnsRemoved = CaretStart;
+  unsigned ColumnsKept = CaretEnd-CaretStart;
+
+  // We checked up front that the line needed truncation
+  assert(FrontColumnsRemoved+ColumnsKept+BackColumnsRemoved > Columns);
+
+  // The line needs some trunctiona, and we'd prefer to keep the front
+  //  if possible, so remove the back
+  if (BackColumnsRemoved)
+    SourceLine.replace(SourceEnd, std::string::npos, back_ellipse);
+
+  // If that's enough then we're done
+  if (FrontColumnsRemoved+ColumnsKept <= Columns)
+    return;
+
+  // Otherwise remove the front as well
+  if (FrontColumnsRemoved) {
+    SourceLine.replace(0, SourceStart, front_ellipse);
+    CaretLine.replace(0, CaretStart, front_space);
+    if (!FixItInsertionLine.empty())
+      FixItInsertionLine.replace(0, CaretStart, front_space);
+  }
+}
+
+/// \brief Skip over whitespace in the string, starting at the given
+/// index.
+///
+/// \returns The index of the first non-whitespace character that is
+/// greater than or equal to Idx or, if no such character exists,
+/// returns the end of the string.
+static unsigned skipWhitespace(unsigned Idx, StringRef Str, unsigned Length) {
+  while (Idx < Length && isspace(Str[Idx]))
+    ++Idx;
+  return Idx;
+}
+
+/// \brief If the given character is the start of some kind of
+/// balanced punctuation (e.g., quotes or parentheses), return the
+/// character that will terminate the punctuation.
+///
+/// \returns The ending punctuation character, if any, or the NULL
+/// character if the input character does not start any punctuation.
+static inline char findMatchingPunctuation(char c) {
+  switch (c) {
+  case '\'': return '\'';
+  case '`': return '\'';
+  case '"':  return '"';
+  case '(':  return ')';
+  case '[': return ']';
+  case '{': return '}';
+  default: break;
+  }
+
+  return 0;
+}
+
+/// \brief Find the end of the word starting at the given offset
+/// within a string.
+///
+/// \returns the index pointing one character past the end of the
+/// word.
+static unsigned findEndOfWord(unsigned Start, StringRef Str,
+                              unsigned Length, unsigned Column,
+                              unsigned Columns) {
+  assert(Start < Str.size() && "Invalid start position!");
+  unsigned End = Start + 1;
+
+  // If we are already at the end of the string, take that as the word.
+  if (End == Str.size())
+    return End;
+
+  // Determine if the start of the string is actually opening
+  // punctuation, e.g., a quote or parentheses.
+  char EndPunct = findMatchingPunctuation(Str[Start]);
+  if (!EndPunct) {
+    // This is a normal word. Just find the first space character.
+    while (End < Length && !isspace(Str[End]))
+      ++End;
+    return End;
+  }
+
+  // We have the start of a balanced punctuation sequence (quotes,
+  // parentheses, etc.). Determine the full sequence is.
+  SmallString<16> PunctuationEndStack;
+  PunctuationEndStack.push_back(EndPunct);
+  while (End < Length && !PunctuationEndStack.empty()) {
+    if (Str[End] == PunctuationEndStack.back())
+      PunctuationEndStack.pop_back();
+    else if (char SubEndPunct = findMatchingPunctuation(Str[End]))
+      PunctuationEndStack.push_back(SubEndPunct);
+
+    ++End;
+  }
+
+  // Find the first space character after the punctuation ended.
+  while (End < Length && !isspace(Str[End]))
+    ++End;
+
+  unsigned PunctWordLength = End - Start;
+  if (// If the word fits on this line
+      Column + PunctWordLength <= Columns ||
+      // ... or the word is "short enough" to take up the next line
+      // without too much ugly white space
+      PunctWordLength < Columns/3)
+    return End; // Take the whole thing as a single "word".
+
+  // The whole quoted/parenthesized string is too long to print as a
+  // single "word". Instead, find the "word" that starts just after
+  // the punctuation and use that end-point instead. This will recurse
+  // until it finds something small enough to consider a word.
+  return findEndOfWord(Start + 1, Str, Length, Column + 1, Columns);
+}
+
+/// \brief Print the given string to a stream, word-wrapping it to
+/// some number of columns in the process.
+///
+/// \param OS the stream to which the word-wrapping string will be
+/// emitted.
+/// \param Str the string to word-wrap and output.
+/// \param Columns the number of columns to word-wrap to.
+/// \param Column the column number at which the first character of \p
+/// Str will be printed. This will be non-zero when part of the first
+/// line has already been printed.
+/// \param Indentation the number of spaces to indent any lines beyond
+/// the first line.
+/// \returns true if word-wrapping was required, or false if the
+/// string fit on the first line.
+static bool printWordWrapped(raw_ostream &OS, StringRef Str,
+                             unsigned Columns,
+                             unsigned Column = 0,
+                             unsigned Indentation = WordWrapIndentation) {
+  const unsigned Length = std::min(Str.find('\n'), Str.size());
+
+  // The string used to indent each line.
+  SmallString<16> IndentStr;
+  IndentStr.assign(Indentation, ' ');
+  bool Wrapped = false;
+  for (unsigned WordStart = 0, WordEnd; WordStart < Length;
+       WordStart = WordEnd) {
+    // Find the beginning of the next word.
+    WordStart = skipWhitespace(WordStart, Str, Length);
+    if (WordStart == Length)
+      break;
+
+    // Find the end of this word.
+    WordEnd = findEndOfWord(WordStart, Str, Length, Column, Columns);
+
+    // Does this word fit on the current line?
+    unsigned WordLength = WordEnd - WordStart;
+    if (Column + WordLength < Columns) {
+      // This word fits on the current line; print it there.
+      if (WordStart) {
+        OS << ' ';
+        Column += 1;
+      }
+      OS << Str.substr(WordStart, WordLength);
+      Column += WordLength;
+      continue;
+    }
+
+    // This word does not fit on the current line, so wrap to the next
+    // line.
+    OS << '\n';
+    OS.write(&IndentStr[0], Indentation);
+    OS << Str.substr(WordStart, WordLength);
+    Column = Indentation + WordLength;
+    Wrapped = true;
+  }
+
+  // Append any remaning text from the message with its existing formatting.
+  OS << Str.substr(Length);
+
+  return Wrapped;
+}
+
+TextDiagnostic::TextDiagnostic(raw_ostream &OS,
+                               const SourceManager &SM,
+                               const LangOptions &LangOpts,
+                               const DiagnosticOptions &DiagOpts)
+  : DiagnosticRenderer(SM, LangOpts, DiagOpts), OS(OS) {}
+
+TextDiagnostic::~TextDiagnostic() {}
+
+void
+TextDiagnostic::emitDiagnosticMessage(SourceLocation Loc,
+                                      PresumedLoc PLoc,
+                                      DiagnosticsEngine::Level Level,
+                                      StringRef Message,
+                                      ArrayRef<clang::CharSourceRange> Ranges,
+                                      DiagOrStoredDiag D) {
+  uint64_t StartOfLocationInfo = OS.tell();
+
+  // Emit the location of this particular diagnostic.
+  emitDiagnosticLoc(Loc, PLoc, Level, Ranges);
+  
+  if (DiagOpts.ShowColors)
+    OS.resetColor();
+  
+  printDiagnosticLevel(OS, Level, DiagOpts.ShowColors);
+  printDiagnosticMessage(OS, Level, Message,
+                         OS.tell() - StartOfLocationInfo,
+                         DiagOpts.MessageLength, DiagOpts.ShowColors);
+}
+
+/*static*/ void
+TextDiagnostic::printDiagnosticLevel(raw_ostream &OS,
+                                     DiagnosticsEngine::Level Level,
+                                     bool ShowColors) {
+  if (ShowColors) {
+    // Print diagnostic category in bold and color
+    switch (Level) {
+    case DiagnosticsEngine::Ignored:
+      llvm_unreachable("Invalid diagnostic type");
+    case DiagnosticsEngine::Note:    OS.changeColor(noteColor, true); break;
+    case DiagnosticsEngine::Warning: OS.changeColor(warningColor, true); break;
+    case DiagnosticsEngine::Error:   OS.changeColor(errorColor, true); break;
+    case DiagnosticsEngine::Fatal:   OS.changeColor(fatalColor, true); break;
+    }
+  }
+
+  switch (Level) {
+  case DiagnosticsEngine::Ignored:
+    llvm_unreachable("Invalid diagnostic type");
+  case DiagnosticsEngine::Note:    OS << "note: "; break;
+  case DiagnosticsEngine::Warning: OS << "warning: "; break;
+  case DiagnosticsEngine::Error:   OS << "error: "; break;
+  case DiagnosticsEngine::Fatal:   OS << "fatal error: "; break;
+  }
+
+  if (ShowColors)
+    OS.resetColor();
+}
+
+/*static*/ void
+TextDiagnostic::printDiagnosticMessage(raw_ostream &OS,
+                                       DiagnosticsEngine::Level Level,
+                                       StringRef Message,
+                                       unsigned CurrentColumn, unsigned Columns,
+                                       bool ShowColors) {
+  if (ShowColors) {
+    // Print warnings, errors and fatal errors in bold, no color
+    switch (Level) {
+    case DiagnosticsEngine::Warning: OS.changeColor(savedColor, true); break;
+    case DiagnosticsEngine::Error:   OS.changeColor(savedColor, true); break;
+    case DiagnosticsEngine::Fatal:   OS.changeColor(savedColor, true); break;
+    default: break; //don't bold notes
+    }
+  }
+
+  if (Columns)
+    printWordWrapped(OS, Message, Columns, CurrentColumn);
+  else
+    OS << Message;
+
+  if (ShowColors)
+    OS.resetColor();
+  OS << '\n';
+}
+
+/// \brief Print out the file/line/column information and include trace.
+///
+/// This method handlen the emission of the diagnostic location information.
+/// This includes extracting as much location information as is present for
+/// the diagnostic and printing it, as well as any include stack or source
+/// ranges necessary.
+void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
+                                       DiagnosticsEngine::Level Level,
+                                       ArrayRef<CharSourceRange> Ranges) {
+  if (PLoc.isInvalid()) {
+    // At least print the file name if available:
+    FileID FID = SM.getFileID(Loc);
+    if (!FID.isInvalid()) {
+      const FileEntry* FE = SM.getFileEntryForID(FID);
+      if (FE && FE->getName()) {
+        OS << FE->getName();
+        if (FE->getDevice() == 0 && FE->getInode() == 0
+            && FE->getFileMode() == 0) {
+          // in PCH is a guess, but a good one:
+          OS << " (in PCH)";
+        }
+        OS << ": ";
+      }
+    }
+    return;
+  }
+  unsigned LineNo = PLoc.getLine();
+
+  if (!DiagOpts.ShowLocation)
+    return;
+
+  if (DiagOpts.ShowColors)
+    OS.changeColor(savedColor, true);
+
+  OS << PLoc.getFilename();
+  switch (DiagOpts.Format) {
+  case DiagnosticOptions::Clang: OS << ':'  << LineNo; break;
+  case DiagnosticOptions::Msvc:  OS << '('  << LineNo; break;
+  case DiagnosticOptions::Vi:    OS << " +" << LineNo; break;
+  }
+
+  if (DiagOpts.ShowColumn)
+    // Compute the column number.
+    if (unsigned ColNo = PLoc.getColumn()) {
+      if (DiagOpts.Format == DiagnosticOptions::Msvc) {
+        OS << ',';
+        ColNo--;
+      } else
+        OS << ':';
+      OS << ColNo;
+    }
+  switch (DiagOpts.Format) {
+  case DiagnosticOptions::Clang:
+  case DiagnosticOptions::Vi:    OS << ':';    break;
+  case DiagnosticOptions::Msvc:  OS << ") : "; break;
+  }
+
+  if (DiagOpts.ShowSourceRanges && !Ranges.empty()) {
+    FileID CaretFileID =
+      SM.getFileID(SM.getExpansionLoc(Loc));
+    bool PrintedRange = false;
+
+    for (ArrayRef<CharSourceRange>::const_iterator RI = Ranges.begin(),
+         RE = Ranges.end();
+         RI != RE; ++RI) {
+      // Ignore invalid ranges.
+      if (!RI->isValid()) continue;
+
+      SourceLocation B = SM.getExpansionLoc(RI->getBegin());
+      SourceLocation E = SM.getExpansionLoc(RI->getEnd());
+
+      // If the End location and the start location are the same and are a
+      // macro location, then the range was something that came from a
+      // macro expansion or _Pragma.  If this is an object-like macro, the
+      // best we can do is to highlight the range.  If this is a
+      // function-like macro, we'd also like to highlight the arguments.
+      if (B == E && RI->getEnd().isMacroID())
+        E = SM.getExpansionRange(RI->getEnd()).second;
+
+      std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(B);
+      std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(E);
+
+      // If the start or end of the range is in another file, just discard
+      // it.
+      if (BInfo.first != CaretFileID || EInfo.first != CaretFileID)
+        continue;
+
+      // Add in the length of the token, so that we cover multi-char
+      // tokens.
+      unsigned TokSize = 0;
+      if (RI->isTokenRange())
+        TokSize = Lexer::MeasureTokenLength(E, SM, LangOpts);
+
+      OS << '{' << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
+        << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
+        << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
+        << (SM.getColumnNumber(EInfo.first, EInfo.second)+TokSize)
+        << '}';
+      PrintedRange = true;
+    }
+
+    if (PrintedRange)
+      OS << ':';
+  }
+  OS << ' ';
+}
+
+void TextDiagnostic::emitBasicNote(StringRef Message) {
+  // FIXME: Emit this as a real note diagnostic.
+  // FIXME: Format an actual diagnostic rather than a hard coded string.
+  OS << "note: " << Message << "\n";
+}
+
+void TextDiagnostic::emitIncludeLocation(SourceLocation Loc,
+                                         PresumedLoc PLoc) {
+  if (DiagOpts.ShowLocation)
+    OS << "In file included from " << PLoc.getFilename() << ':'
+       << PLoc.getLine() << ":\n";
+  else
+    OS << "In included file:\n"; 
+}
+
+/// \brief Emit a code snippet and caret line.
+///
+/// This routine emits a single line's code snippet and caret line..
+///
+/// \param Loc The location for the caret.
+/// \param Ranges The underlined ranges for this code snippet.
+/// \param Hints The FixIt hints active for this diagnostic.
+void TextDiagnostic::emitSnippetAndCaret(
+    SourceLocation Loc, DiagnosticsEngine::Level Level,
+    SmallVectorImpl<CharSourceRange>& Ranges,
+    ArrayRef<FixItHint> Hints) {
+  assert(!Loc.isInvalid() && "must have a valid source location here");
+  assert(Loc.isFileID() && "must have a file location here");
+
+  // If caret diagnostics are enabled and we have location, we want to
+  // emit the caret.  However, we only do this if the location moved
+  // from the last diagnostic, if the last diagnostic was a note that
+  // was part of a different warning or error diagnostic, or if the
+  // diagnostic has ranges.  We don't want to emit the same caret
+  // multiple times if one loc has multiple diagnostics.
+  if (!DiagOpts.ShowCarets)
+    return;
+  if (Loc == LastLoc && Ranges.empty() && Hints.empty() &&
+      (LastLevel != DiagnosticsEngine::Note || Level == LastLevel))
+    return;
+
+  // Decompose the location into a FID/Offset pair.
+  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
+  FileID FID = LocInfo.first;
+  unsigned FileOffset = LocInfo.second;
+
+  // Get information about the buffer it points into.
+  bool Invalid = false;
+  StringRef BufData = SM.getBufferData(FID, &Invalid);
+  if (Invalid)
+    return;
+
+  const char *BufStart = BufData.data();
+  const char *BufEnd = BufStart + BufData.size();
+
+  unsigned LineNo = SM.getLineNumber(FID, FileOffset);
+  unsigned ColNo = SM.getColumnNumber(FID, FileOffset);
+  unsigned CaretEndColNo
+    = ColNo + Lexer::MeasureTokenLength(Loc, SM, LangOpts);
+
+  // Rewind from the current position to the start of the line.
+  const char *TokPtr = BufStart+FileOffset;
+  const char *LineStart = TokPtr-ColNo+1; // Column # is 1-based.
+
+
+  // Compute the line end.  Scan forward from the error position to the end of
+  // the line.
+  const char *LineEnd = TokPtr;
+  while (*LineEnd != '\n' && *LineEnd != '\r' && LineEnd!=BufEnd)
+    ++LineEnd;
+
+  // FIXME: This shouldn't be necessary, but the CaretEndColNo can extend past
+  // the source line length as currently being computed. See
+  // test/Misc/message-length.c.
+  CaretEndColNo = std::min(CaretEndColNo, unsigned(LineEnd - LineStart));
+
+  // Copy the line of code into an std::string for ease of manipulation.
+  std::string SourceLine(LineStart, LineEnd);
+
+  // Create a line for the caret that is filled with spaces that is the same
+  // length as the line of source code.
+  std::string CaretLine(LineEnd-LineStart, ' ');
+
+  const SourceColumnMap sourceColMap(SourceLine, DiagOpts.TabStop);
+
+  // Highlight all of the characters covered by Ranges with ~ characters.
+  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
+                                                  E = Ranges.end();
+       I != E; ++I)
+    highlightRange(*I, LineNo, FID, sourceColMap, CaretLine);
+
+  // Next, insert the caret itself.
+  ColNo = sourceColMap.byteToColumn(ColNo-1);
+  if (CaretLine.size()<ColNo+1)
+    CaretLine.resize(ColNo+1, ' ');
+  CaretLine[ColNo] = '^';
+
+  std::string FixItInsertionLine = buildFixItInsertionLine(LineNo,
+                                                           sourceColMap,
+                                                           Hints);
+
+  // If the source line is too long for our terminal, select only the
+  // "interesting" source region within that line.
+  unsigned Columns = DiagOpts.MessageLength;
+  if (Columns)
+    selectInterestingSourceRegion(SourceLine, CaretLine, FixItInsertionLine,
+                                  Columns, sourceColMap);
+
+  // If we are in -fdiagnostics-print-source-range-info mode, we are trying
+  // to produce easily machine parsable output.  Add a space before the
+  // source line and the caret to make it trivial to tell the main diagnostic
+  // line from what the user is intended to see.
+  if (DiagOpts.ShowSourceRanges) {
+    SourceLine = ' ' + SourceLine;
+    CaretLine = ' ' + CaretLine;
+  }
+
+  // Finally, remove any blank spaces from the end of CaretLine.
+  while (CaretLine[CaretLine.size()-1] == ' ')
+    CaretLine.erase(CaretLine.end()-1);
+
+  // Emit what we have computed.
+  emitSnippet(SourceLine);
+
+  if (DiagOpts.ShowColors)
+    OS.changeColor(caretColor, true);
+  OS << CaretLine << '\n';
+  if (DiagOpts.ShowColors)
+    OS.resetColor();
+
+  if (!FixItInsertionLine.empty()) {
+    if (DiagOpts.ShowColors)
+      // Print fixit line in color
+      OS.changeColor(fixitColor, false);
+    if (DiagOpts.ShowSourceRanges)
+      OS << ' ';
+    OS << FixItInsertionLine << '\n';
+    if (DiagOpts.ShowColors)
+      OS.resetColor();
+  }
+
+  // Print out any parseable fixit information requested by the options.
+  emitParseableFixits(Hints);
+}
+
+void TextDiagnostic::emitSnippet(StringRef line)
+{
+  if (line.empty())
+    return;
+
+  size_t i = 0;
+  
+  std::string to_print;
+  bool print_reversed = false;
+  
+  while (i<line.size()) {
+    std::pair<SmallString<16>,bool> res
+        = printableTextForNextCharacter(line, &i, DiagOpts.TabStop);
+    bool was_printable = res.second;
+    
+    if (DiagOpts.ShowColors
+        && was_printable==print_reversed) {
+      if (print_reversed)
+        OS.reverseColor();
+      OS << to_print;
+      to_print.clear();
+      if (DiagOpts.ShowColors)
+        OS.resetColor();
+    }
+    
+    print_reversed = !was_printable;
+    to_print += res.first.str();
+  }
+  
+  if (print_reversed && DiagOpts.ShowColors)
+    OS.reverseColor();
+  OS << to_print;
+  if (print_reversed && DiagOpts.ShowColors)
+    OS.resetColor();
+  
+  OS << '\n';
+}
+
+/// \brief Highlight a SourceRange (with ~'s) for any characters on LineNo.
+void TextDiagnostic::highlightRange(const CharSourceRange &R,
+                                    unsigned LineNo, FileID FID,
+                                    const SourceColumnMap &map,
+                                    std::string &CaretLine) {
+  if (!R.isValid()) return;
+
+  SourceLocation Begin = SM.getExpansionLoc(R.getBegin());
+  SourceLocation End = SM.getExpansionLoc(R.getEnd());
+
+  // If the End location and the start location are the same and are a macro
+  // location, then the range was something that came from a macro expansion
+  // or _Pragma.  If this is an object-like macro, the best we can do is to
+  // highlight the range.  If this is a function-like macro, we'd also like to
+  // highlight the arguments.
+  if (Begin == End && R.getEnd().isMacroID())
+    End = SM.getExpansionRange(R.getEnd()).second;
+
+  unsigned StartLineNo = SM.getExpansionLineNumber(Begin);
+  if (StartLineNo > LineNo || SM.getFileID(Begin) != FID)
+    return;  // No intersection.
+
+  unsigned EndLineNo = SM.getExpansionLineNumber(End);
+  if (EndLineNo < LineNo || SM.getFileID(End) != FID)
+    return;  // No intersection.
+
+  // Compute the column number of the start.
+  unsigned StartColNo = 0;
+  if (StartLineNo == LineNo) {
+    StartColNo = SM.getExpansionColumnNumber(Begin);
+    if (StartColNo) --StartColNo;  // Zero base the col #.
+  }
+
+  // Compute the column number of the end.
+  unsigned EndColNo = map.getSourceLine().size();
+  if (EndLineNo == LineNo) {
+    EndColNo = SM.getExpansionColumnNumber(End);
+    if (EndColNo) {
+      --EndColNo;  // Zero base the col #.
+
+      // Add in the length of the token, so that we cover multi-char tokens if
+      // this is a token range.
+      if (R.isTokenRange())
+        EndColNo += Lexer::MeasureTokenLength(End, SM, LangOpts);
+    } else {
+      EndColNo = CaretLine.size();
+    }
+  }
+
+  assert(StartColNo <= EndColNo && "Invalid range!");
+
+  // Check that a token range does not highlight only whitespace.
+  if (R.isTokenRange()) {
+    // Pick the first non-whitespace column.
+    while (StartColNo < map.getSourceLine().size() &&
+           (map.getSourceLine()[StartColNo] == ' ' ||
+            map.getSourceLine()[StartColNo] == '\t'))
+      ++StartColNo;
+
+    // Pick the last non-whitespace column.
+    if (EndColNo > map.getSourceLine().size())
+      EndColNo = map.getSourceLine().size();
+    while (EndColNo-1 &&
+           (map.getSourceLine()[EndColNo-1] == ' ' ||
+            map.getSourceLine()[EndColNo-1] == '\t'))
+      --EndColNo;
+
+    // If the start/end passed each other, then we are trying to highlight a
+    // range that just exists in whitespace, which must be some sort of other
+    // bug.
+    assert(StartColNo <= EndColNo && "Trying to highlight whitespace??");
+  }
+
+  assert(StartColNo <= map.getSourceLine().size() && "Invalid range!");
+  assert(EndColNo <= map.getSourceLine().size() && "Invalid range!");
+
+  // Fill the range with ~'s.
+  StartColNo = map.byteToColumn(StartColNo);
+  EndColNo = map.byteToColumn(EndColNo);
+
+  assert(StartColNo <= EndColNo && "Invalid range!");
+  if (CaretLine.size() < EndColNo)
+    CaretLine.resize(EndColNo,' ');
+  std::fill(CaretLine.begin()+StartColNo,CaretLine.begin()+EndColNo,'~');
+}
+
+std::string TextDiagnostic::buildFixItInsertionLine(
+  unsigned LineNo,
+  const SourceColumnMap &map,
+  ArrayRef<FixItHint> Hints) {
+
+  std::string FixItInsertionLine;
+  if (Hints.empty() || !DiagOpts.ShowFixits)
+    return FixItInsertionLine;
+
+  for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
+       I != E; ++I) {
+    if (!I->CodeToInsert.empty()) {
+      // We have an insertion hint. Determine whether the inserted
+      // code is on the same line as the caret.
+      std::pair<FileID, unsigned> HintLocInfo
+        = SM.getDecomposedExpansionLoc(I->RemoveRange.getBegin());
+      if (LineNo == SM.getLineNumber(HintLocInfo.first, HintLocInfo.second)) {
+        // Insert the new code into the line just below the code
+        // that the user wrote.
+        unsigned HintColNo
+          = SM.getColumnNumber(HintLocInfo.first, HintLocInfo.second) - 1;
+        // hint must start inside the source or right at the end
+        assert(HintColNo<static_cast<unsigned>(map.bytes())+1);
+        HintColNo = map.byteToColumn(HintColNo);
+
+        // FIXME: if the fixit includes tabs or other characters that do not
+        //  take up a single column per byte when displayed then
+        //  I->CodeToInsert.size() is not a column number and we're mixing
+        //  units (columns + bytes). We should get printable versions
+        //  of each fixit before using them.
+        unsigned LastColumnModified
+          = HintColNo + I->CodeToInsert.size();
+
+        if (LastColumnModified > static_cast<unsigned>(map.bytes())) {
+          unsigned LastExistingColumn = map.byteToColumn(map.bytes());
+          unsigned AddedColumns = LastColumnModified-LastExistingColumn;
+          LastColumnModified = LastExistingColumn + AddedColumns;
+        } else {
+          LastColumnModified = map.byteToColumn(LastColumnModified);
+        }
+
+        if (LastColumnModified > FixItInsertionLine.size())
+          FixItInsertionLine.resize(LastColumnModified, ' ');
+        assert(HintColNo+I->CodeToInsert.size() <= FixItInsertionLine.size());
+        std::copy(I->CodeToInsert.begin(), I->CodeToInsert.end(),
+                  FixItInsertionLine.begin() + HintColNo);
+      } else {
+        FixItInsertionLine.clear();
+        break;
+      }
+    }
+  }
+
+  expandTabs(FixItInsertionLine, DiagOpts.TabStop);
+
+  return FixItInsertionLine;
+}
+
+void TextDiagnostic::emitParseableFixits(ArrayRef<FixItHint> Hints) {
+  if (!DiagOpts.ShowParseableFixits)
+    return;
+
+  // We follow FixItRewriter's example in not (yet) handling
+  // fix-its in macros.
+  for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
+       I != E; ++I) {
+    if (I->RemoveRange.isInvalid() ||
+        I->RemoveRange.getBegin().isMacroID() ||
+        I->RemoveRange.getEnd().isMacroID())
+      return;
+  }
+
+  for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
+       I != E; ++I) {
+    SourceLocation BLoc = I->RemoveRange.getBegin();
+    SourceLocation ELoc = I->RemoveRange.getEnd();
+
+    std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
+    std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
+
+    // Adjust for token ranges.
+    if (I->RemoveRange.isTokenRange())
+      EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, LangOpts);
+
+    // We specifically do not do word-wrapping or tab-expansion here,
+    // because this is supposed to be easy to parse.
+    PresumedLoc PLoc = SM.getPresumedLoc(BLoc);
+    if (PLoc.isInvalid())
+      break;
+
+    OS << "fix-it:\"";
+    OS.write_escaped(PLoc.getFilename());
+    OS << "\":{" << SM.getLineNumber(BInfo.first, BInfo.second)
+      << ':' << SM.getColumnNumber(BInfo.first, BInfo.second)
+      << '-' << SM.getLineNumber(EInfo.first, EInfo.second)
+      << ':' << SM.getColumnNumber(EInfo.first, EInfo.second)
+      << "}:\"";
+    OS.write_escaped(I->CodeToInsert);
+    OS << "\"\n";
+  }
+}
diff --git a/clang/lib/Frontend/TextDiagnosticBuffer.cpp b/clang/lib/Frontend/TextDiagnosticBuffer.cpp
new file mode 100644
index 0000000..57105f1
--- /dev/null
+++ b/clang/lib/Frontend/TextDiagnosticBuffer.cpp
@@ -0,0 +1,60 @@
+//===--- TextDiagnosticBuffer.cpp - Buffer Text Diagnostics ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a concrete diagnostic client, which buffers the diagnostic messages.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/TextDiagnosticBuffer.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/ErrorHandling.h"
+using namespace clang;
+
+/// HandleDiagnostic - Store the errors, warnings, and notes that are
+/// reported.
+///
+void TextDiagnosticBuffer::HandleDiagnostic(DiagnosticsEngine::Level Level,
+                                            const Diagnostic &Info) {
+  // Default implementation (Warnings/errors count).
+  DiagnosticConsumer::HandleDiagnostic(Level, Info);
+
+  SmallString<100> Buf;
+  Info.FormatDiagnostic(Buf);
+  switch (Level) {
+  default: llvm_unreachable(
+                         "Diagnostic not handled during diagnostic buffering!");
+  case DiagnosticsEngine::Note:
+    Notes.push_back(std::make_pair(Info.getLocation(), Buf.str()));
+    break;
+  case DiagnosticsEngine::Warning:
+    Warnings.push_back(std::make_pair(Info.getLocation(), Buf.str()));
+    break;
+  case DiagnosticsEngine::Error:
+  case DiagnosticsEngine::Fatal:
+    Errors.push_back(std::make_pair(Info.getLocation(), Buf.str()));
+    break;
+  }
+}
+
+void TextDiagnosticBuffer::FlushDiagnostics(DiagnosticsEngine &Diags) const {
+  // FIXME: Flush the diagnostics in order.
+  for (const_iterator it = err_begin(), ie = err_end(); it != ie; ++it)
+    Diags.Report(Diags.getCustomDiagID(DiagnosticsEngine::Error,
+                 it->second.c_str()));
+  for (const_iterator it = warn_begin(), ie = warn_end(); it != ie; ++it)
+    Diags.Report(Diags.getCustomDiagID(DiagnosticsEngine::Warning,
+                 it->second.c_str()));
+  for (const_iterator it = note_begin(), ie = note_end(); it != ie; ++it)
+    Diags.Report(Diags.getCustomDiagID(DiagnosticsEngine::Note,
+                 it->second.c_str()));
+}
+
+DiagnosticConsumer *TextDiagnosticBuffer::clone(DiagnosticsEngine &) const {
+  return new TextDiagnosticBuffer();
+}
diff --git a/clang/lib/Frontend/TextDiagnosticPrinter.cpp b/clang/lib/Frontend/TextDiagnosticPrinter.cpp
new file mode 100644
index 0000000..6445a0c
--- /dev/null
+++ b/clang/lib/Frontend/TextDiagnosticPrinter.cpp
@@ -0,0 +1,178 @@
+//===--- TextDiagnosticPrinter.cpp - Diagnostic Printer -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This diagnostic client prints out their diagnostic messages.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/TextDiagnostic.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/SmallString.h"
+#include <algorithm>
+using namespace clang;
+
+TextDiagnosticPrinter::TextDiagnosticPrinter(raw_ostream &os,
+                                             const DiagnosticOptions &diags,
+                                             bool _OwnsOutputStream)
+  : OS(os), LangOpts(0), DiagOpts(&diags), SM(0),
+    OwnsOutputStream(_OwnsOutputStream) {
+}
+
+TextDiagnosticPrinter::~TextDiagnosticPrinter() {
+  if (OwnsOutputStream)
+    delete &OS;
+}
+
+void TextDiagnosticPrinter::BeginSourceFile(const LangOptions &LO,
+                                            const Preprocessor *PP) {
+  LangOpts = &LO;
+}
+
+void TextDiagnosticPrinter::EndSourceFile() {
+  LangOpts = 0;
+  TextDiag.reset(0);
+}
+
+/// \brief Print any diagnostic option information to a raw_ostream.
+///
+/// This implements all of the logic for adding diagnostic options to a message
+/// (via OS). Each relevant option is comma separated and all are enclosed in
+/// the standard bracketing: " [...]".
+static void printDiagnosticOptions(raw_ostream &OS,
+                                   DiagnosticsEngine::Level Level,
+                                   const Diagnostic &Info,
+                                   const DiagnosticOptions &DiagOpts) {
+  bool Started = false;
+  if (DiagOpts.ShowOptionNames) {
+    // Handle special cases for non-warnings early.
+    if (Info.getID() == diag::fatal_too_many_errors) {
+      OS << " [-ferror-limit=]";
+      return;
+    }
+
+    // The code below is somewhat fragile because we are essentially trying to
+    // report to the user what happened by inferring what the diagnostic engine
+    // did. Eventually it might make more sense to have the diagnostic engine
+    // include some "why" information in the diagnostic.
+
+    // If this is a warning which has been mapped to an error by the user (as
+    // inferred by checking whether the default mapping is to an error) then
+    // flag it as such. Note that diagnostics could also have been mapped by a
+    // pragma, but we don't currently have a way to distinguish this.
+    if (Level == DiagnosticsEngine::Error &&
+        DiagnosticIDs::isBuiltinWarningOrExtension(Info.getID()) &&
+        !DiagnosticIDs::isDefaultMappingAsError(Info.getID())) {
+      OS << " [-Werror";
+      Started = true;
+    }
+
+    // If the diagnostic is an extension diagnostic and not enabled by default
+    // then it must have been turned on with -pedantic.
+    bool EnabledByDefault;
+    if (DiagnosticIDs::isBuiltinExtensionDiag(Info.getID(),
+                                              EnabledByDefault) &&
+        !EnabledByDefault) {
+      OS << (Started ? "," : " [") << "-pedantic";
+      Started = true;
+    }
+
+    StringRef Opt = DiagnosticIDs::getWarningOptionForDiag(Info.getID());
+    if (!Opt.empty()) {
+      OS << (Started ? "," : " [") << "-W" << Opt;
+      Started = true;
+    }
+  }
+
+  // If the user wants to see category information, include it too.
+  if (DiagOpts.ShowCategories) {
+    unsigned DiagCategory =
+      DiagnosticIDs::getCategoryNumberForDiag(Info.getID());
+    if (DiagCategory) {
+      OS << (Started ? "," : " [");
+      Started = true;
+      if (DiagOpts.ShowCategories == 1)
+        OS << DiagCategory;
+      else {
+        assert(DiagOpts.ShowCategories == 2 && "Invalid ShowCategories value");
+        OS << DiagnosticIDs::getCategoryNameFromID(DiagCategory);
+      }
+    }
+  }
+  if (Started)
+    OS << ']';
+}
+
+void TextDiagnosticPrinter::HandleDiagnostic(DiagnosticsEngine::Level Level,
+                                             const Diagnostic &Info) {
+  // Default implementation (Warnings/errors count).
+  DiagnosticConsumer::HandleDiagnostic(Level, Info);
+
+  // Render the diagnostic message into a temporary buffer eagerly. We'll use
+  // this later as we print out the diagnostic to the terminal.
+  SmallString<100> OutStr;
+  Info.FormatDiagnostic(OutStr);
+
+  llvm::raw_svector_ostream DiagMessageStream(OutStr);
+  printDiagnosticOptions(DiagMessageStream, Level, Info, *DiagOpts);
+
+  // Keeps track of the the starting position of the location
+  // information (e.g., "foo.c:10:4:") that precedes the error
+  // message. We use this information to determine how long the
+  // file+line+column number prefix is.
+  uint64_t StartOfLocationInfo = OS.tell();
+
+  if (!Prefix.empty())
+    OS << Prefix << ": ";
+
+  // Use a dedicated, simpler path for diagnostics without a valid location.
+  // This is important as if the location is missing, we may be emitting
+  // diagnostics in a context that lacks language options, a source manager, or
+  // other infrastructure necessary when emitting more rich diagnostics.
+  if (!Info.getLocation().isValid()) {
+    TextDiagnostic::printDiagnosticLevel(OS, Level, DiagOpts->ShowColors);
+    TextDiagnostic::printDiagnosticMessage(OS, Level, DiagMessageStream.str(),
+                                           OS.tell() - StartOfLocationInfo,
+                                           DiagOpts->MessageLength,
+                                           DiagOpts->ShowColors);
+    OS.flush();
+    return;
+  }
+
+  // Assert that the rest of our infrastructure is setup properly.
+  assert(LangOpts && "Unexpected diagnostic outside source file processing");
+  assert(DiagOpts && "Unexpected diagnostic without options set");
+  assert(Info.hasSourceManager() &&
+         "Unexpected diagnostic with no source manager");
+
+  // Rebuild the TextDiagnostic utility if missing or the source manager has
+  // changed.
+  if (!TextDiag || SM != &Info.getSourceManager()) {
+    SM = &Info.getSourceManager();
+    TextDiag.reset(new TextDiagnostic(OS, *SM, *LangOpts, *DiagOpts));
+  }
+
+  TextDiag->emitDiagnostic(Info.getLocation(), Level, DiagMessageStream.str(),
+                           Info.getRanges(),
+                           llvm::makeArrayRef(Info.getFixItHints(),
+                                              Info.getNumFixItHints()));
+
+  OS.flush();
+}
+
+DiagnosticConsumer *
+TextDiagnosticPrinter::clone(DiagnosticsEngine &Diags) const {
+  return new TextDiagnosticPrinter(OS, *DiagOpts, /*OwnsOutputStream=*/false);
+}
diff --git a/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
new file mode 100644
index 0000000..552282d
--- /dev/null
+++ b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -0,0 +1,557 @@
+//===---- VerifyDiagnosticConsumer.cpp - Verifying Diagnostic Client ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a concrete diagnostic client, which buffers the diagnostic messages.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/VerifyDiagnosticConsumer.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/TextDiagnosticBuffer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/raw_ostream.h"
+#include <climits>
+
+using namespace clang;
+
+VerifyDiagnosticConsumer::VerifyDiagnosticConsumer(DiagnosticsEngine &_Diags)
+  : Diags(_Diags), PrimaryClient(Diags.getClient()),
+    OwnsPrimaryClient(Diags.ownsClient()),
+    Buffer(new TextDiagnosticBuffer()), CurrentPreprocessor(0) 
+{
+  Diags.takeClient();
+}
+
+VerifyDiagnosticConsumer::~VerifyDiagnosticConsumer() {
+  CheckDiagnostics();  
+  Diags.takeClient();
+  if (OwnsPrimaryClient)
+    delete PrimaryClient;
+}
+
+// DiagnosticConsumer interface.
+
+void VerifyDiagnosticConsumer::BeginSourceFile(const LangOptions &LangOpts,
+                                               const Preprocessor *PP) {
+  // FIXME: Const hack, we screw up the preprocessor but in practice its ok
+  // because it doesn't get reused. It would be better if we could make a copy
+  // though.
+  CurrentPreprocessor = const_cast<Preprocessor*>(PP);
+
+  PrimaryClient->BeginSourceFile(LangOpts, PP);
+}
+
+void VerifyDiagnosticConsumer::EndSourceFile() {
+  CheckDiagnostics();
+
+  PrimaryClient->EndSourceFile();
+
+  CurrentPreprocessor = 0;
+}
+
+void VerifyDiagnosticConsumer::HandleDiagnostic(
+      DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {
+  if (FirstErrorFID.isInvalid() && Info.hasSourceManager()) {
+    const SourceManager &SM = Info.getSourceManager();
+    FirstErrorFID = SM.getFileID(Info.getLocation());
+  }
+  // Send the diagnostic to the buffer, we will check it once we reach the end
+  // of the source file (or are destructed).
+  Buffer->HandleDiagnostic(DiagLevel, Info);
+}
+
+//===----------------------------------------------------------------------===//
+// Checking diagnostics implementation.
+//===----------------------------------------------------------------------===//
+
+typedef TextDiagnosticBuffer::DiagList DiagList;
+typedef TextDiagnosticBuffer::const_iterator const_diag_iterator;
+
+namespace {
+
+/// Directive - Abstract class representing a parsed verify directive.
+///
+class Directive {
+public:
+  static Directive* Create(bool RegexKind, const SourceLocation &Location,
+                           const std::string &Text, unsigned Count);
+public:
+  /// Constant representing one or more matches aka regex "+".
+  static const unsigned OneOrMoreCount =  UINT_MAX;
+
+  SourceLocation Location;
+  const std::string Text;
+  unsigned Count;
+
+  virtual ~Directive() { }
+
+  // Returns true if directive text is valid.
+  // Otherwise returns false and populates E.
+  virtual bool isValid(std::string &Error) = 0;
+
+  // Returns true on match.
+  virtual bool Match(const std::string &S) = 0;
+
+protected:
+  Directive(const SourceLocation &Location, const std::string &Text,
+            unsigned Count)
+    : Location(Location), Text(Text), Count(Count) { }
+
+private:
+  Directive(const Directive&); // DO NOT IMPLEMENT
+  void operator=(const Directive&); // DO NOT IMPLEMENT
+};
+
+/// StandardDirective - Directive with string matching.
+///
+class StandardDirective : public Directive {
+public:
+  StandardDirective(const SourceLocation &Location, const std::string &Text,
+                    unsigned Count)
+    : Directive(Location, Text, Count) { }
+
+  virtual bool isValid(std::string &Error) {
+    // all strings are considered valid; even empty ones
+    return true;
+  }
+
+  virtual bool Match(const std::string &S) {
+    return S.find(Text) != std::string::npos;
+  }
+};
+
+/// RegexDirective - Directive with regular-expression matching.
+///
+class RegexDirective : public Directive {
+public:
+  RegexDirective(const SourceLocation &Location, const std::string &Text,
+                 unsigned Count)
+    : Directive(Location, Text, Count), Regex(Text) { }
+
+  virtual bool isValid(std::string &Error) {
+    if (Regex.isValid(Error))
+      return true;
+    return false;
+  }
+
+  virtual bool Match(const std::string &S) {
+    return Regex.match(S);
+  }
+
+private:
+  llvm::Regex Regex;
+};
+
+typedef std::vector<Directive*> DirectiveList;
+
+/// ExpectedData - owns directive objects and deletes on destructor.
+///
+struct ExpectedData {
+  DirectiveList Errors;
+  DirectiveList Warnings;
+  DirectiveList Notes;
+
+  ~ExpectedData() {
+    DirectiveList* Lists[] = { &Errors, &Warnings, &Notes, 0 };
+    for (DirectiveList **PL = Lists; *PL; ++PL) {
+      DirectiveList * const L = *PL;
+      for (DirectiveList::iterator I = L->begin(), E = L->end(); I != E; ++I)
+        delete *I;
+    }
+  }
+};  
+
+class ParseHelper
+{
+public:
+  ParseHelper(const char *Begin, const char *End)
+    : Begin(Begin), End(End), C(Begin), P(Begin), PEnd(NULL) { }
+
+  // Return true if string literal is next.
+  bool Next(StringRef S) {
+    P = C;
+    PEnd = C + S.size();
+    if (PEnd > End)
+      return false;
+    return !memcmp(P, S.data(), S.size());
+  }
+
+  // Return true if number is next.
+  // Output N only if number is next.
+  bool Next(unsigned &N) {
+    unsigned TMP = 0;
+    P = C;
+    for (; P < End && P[0] >= '0' && P[0] <= '9'; ++P) {
+      TMP *= 10;
+      TMP += P[0] - '0';
+    }
+    if (P == C)
+      return false;
+    PEnd = P;
+    N = TMP;
+    return true;
+  }
+
+  // Return true if string literal is found.
+  // When true, P marks begin-position of S in content.
+  bool Search(StringRef S) {
+    P = std::search(C, End, S.begin(), S.end());
+    PEnd = P + S.size();
+    return P != End;
+  }
+
+  // Advance 1-past previous next/search.
+  // Behavior is undefined if previous next/search failed.
+  bool Advance() {
+    C = PEnd;
+    return C < End;
+  }
+
+  // Skip zero or more whitespace.
+  void SkipWhitespace() {
+    for (; C < End && isspace(*C); ++C)
+      ;
+  }
+
+  // Return true if EOF reached.
+  bool Done() {
+    return !(C < End);
+  }
+
+  const char * const Begin; // beginning of expected content
+  const char * const End;   // end of expected content (1-past)
+  const char *C;            // position of next char in content
+  const char *P;
+
+private:
+  const char *PEnd; // previous next/search subject end (1-past)
+};
+
+} // namespace anonymous
+
+/// ParseDirective - Go through the comment and see if it indicates expected
+/// diagnostics. If so, then put them in the appropriate directive list.
+///
+static void ParseDirective(const char *CommentStart, unsigned CommentLen,
+                           ExpectedData &ED, Preprocessor &PP,
+                           SourceLocation Pos) {
+  // A single comment may contain multiple directives.
+  for (ParseHelper PH(CommentStart, CommentStart+CommentLen); !PH.Done();) {
+    // search for token: expected
+    if (!PH.Search("expected"))
+      break;
+    PH.Advance();
+
+    // next token: -
+    if (!PH.Next("-"))
+      continue;
+    PH.Advance();
+
+    // next token: { error | warning | note }
+    DirectiveList* DL = NULL;
+    if (PH.Next("error"))
+      DL = &ED.Errors;
+    else if (PH.Next("warning"))
+      DL = &ED.Warnings;
+    else if (PH.Next("note"))
+      DL = &ED.Notes;
+    else
+      continue;
+    PH.Advance();
+
+    // default directive kind
+    bool RegexKind = false;
+    const char* KindStr = "string";
+
+    // next optional token: -
+    if (PH.Next("-re")) {
+      PH.Advance();
+      RegexKind = true;
+      KindStr = "regex";
+    }
+
+    // skip optional whitespace
+    PH.SkipWhitespace();
+
+    // next optional token: positive integer or a '+'.
+    unsigned Count = 1;
+    if (PH.Next(Count))
+      PH.Advance();
+    else if (PH.Next("+")) {
+      Count = Directive::OneOrMoreCount;
+      PH.Advance();
+    }
+
+    // skip optional whitespace
+    PH.SkipWhitespace();
+
+    // next token: {{
+    if (!PH.Next("{{")) {
+      PP.Diag(Pos.getLocWithOffset(PH.C-PH.Begin),
+              diag::err_verify_missing_start) << KindStr;
+      continue;
+    }
+    PH.Advance();
+    const char* const ContentBegin = PH.C; // mark content begin
+
+    // search for token: }}
+    if (!PH.Search("}}")) {
+      PP.Diag(Pos.getLocWithOffset(PH.C-PH.Begin),
+              diag::err_verify_missing_end) << KindStr;
+      continue;
+    }
+    const char* const ContentEnd = PH.P; // mark content end
+    PH.Advance();
+
+    // build directive text; convert \n to newlines
+    std::string Text;
+    StringRef NewlineStr = "\\n";
+    StringRef Content(ContentBegin, ContentEnd-ContentBegin);
+    size_t CPos = 0;
+    size_t FPos;
+    while ((FPos = Content.find(NewlineStr, CPos)) != StringRef::npos) {
+      Text += Content.substr(CPos, FPos-CPos);
+      Text += '\n';
+      CPos = FPos + NewlineStr.size();
+    }
+    if (Text.empty())
+      Text.assign(ContentBegin, ContentEnd);
+
+    // construct new directive
+    Directive *D = Directive::Create(RegexKind, Pos, Text, Count);
+    std::string Error;
+    if (D->isValid(Error))
+      DL->push_back(D);
+    else {
+      PP.Diag(Pos.getLocWithOffset(ContentBegin-PH.Begin),
+              diag::err_verify_invalid_content)
+        << KindStr << Error;
+    }
+  }
+}
+
+/// FindExpectedDiags - Lex the main source file to find all of the
+//   expected errors and warnings.
+static void FindExpectedDiags(Preprocessor &PP, ExpectedData &ED, FileID FID) {
+  // Create a raw lexer to pull all the comments out of FID.
+  if (FID.isInvalid())
+    return;
+
+  SourceManager& SM = PP.getSourceManager();
+  // Create a lexer to lex all the tokens of the main file in raw mode.
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+  Lexer RawLex(FID, FromFile, SM, PP.getLangOpts());
+
+  // Return comments as tokens, this is how we find expected diagnostics.
+  RawLex.SetCommentRetentionState(true);
+
+  Token Tok;
+  Tok.setKind(tok::comment);
+  while (Tok.isNot(tok::eof)) {
+    RawLex.Lex(Tok);
+    if (!Tok.is(tok::comment)) continue;
+
+    std::string Comment = PP.getSpelling(Tok);
+    if (Comment.empty()) continue;
+
+    // Find all expected errors/warnings/notes.
+    ParseDirective(&Comment[0], Comment.size(), ED, PP, Tok.getLocation());
+  };
+}
+
+/// PrintProblem - This takes a diagnostic map of the delta between expected and
+/// seen diagnostics. If there's anything in it, then something unexpected
+/// happened. Print the map out in a nice format and return "true". If the map
+/// is empty and we're not going to print things, then return "false".
+///
+static unsigned PrintProblem(DiagnosticsEngine &Diags, SourceManager *SourceMgr,
+                             const_diag_iterator diag_begin,
+                             const_diag_iterator diag_end,
+                             const char *Kind, bool Expected) {
+  if (diag_begin == diag_end) return 0;
+
+  SmallString<256> Fmt;
+  llvm::raw_svector_ostream OS(Fmt);
+  for (const_diag_iterator I = diag_begin, E = diag_end; I != E; ++I) {
+    if (I->first.isInvalid() || !SourceMgr)
+      OS << "\n  (frontend)";
+    else
+      OS << "\n  Line " << SourceMgr->getPresumedLineNumber(I->first);
+    OS << ": " << I->second;
+  }
+
+  Diags.Report(diag::err_verify_inconsistent_diags)
+    << Kind << !Expected << OS.str();
+  return std::distance(diag_begin, diag_end);
+}
+
+static unsigned PrintProblem(DiagnosticsEngine &Diags, SourceManager *SourceMgr,
+                             DirectiveList &DL, const char *Kind,
+                             bool Expected) {
+  if (DL.empty())
+    return 0;
+
+  SmallString<256> Fmt;
+  llvm::raw_svector_ostream OS(Fmt);
+  for (DirectiveList::iterator I = DL.begin(), E = DL.end(); I != E; ++I) {
+    Directive& D = **I;
+    if (D.Location.isInvalid() || !SourceMgr)
+      OS << "\n  (frontend)";
+    else
+      OS << "\n  Line " << SourceMgr->getPresumedLineNumber(D.Location);
+    OS << ": " << D.Text;
+  }
+
+  Diags.Report(diag::err_verify_inconsistent_diags)
+    << Kind << !Expected << OS.str();
+  return DL.size();
+}
+
+/// CheckLists - Compare expected to seen diagnostic lists and return the
+/// the difference between them.
+///
+static unsigned CheckLists(DiagnosticsEngine &Diags, SourceManager &SourceMgr,
+                           const char *Label,
+                           DirectiveList &Left,
+                           const_diag_iterator d2_begin,
+                           const_diag_iterator d2_end) {
+  DirectiveList LeftOnly;
+  DiagList Right(d2_begin, d2_end);
+
+  for (DirectiveList::iterator I = Left.begin(), E = Left.end(); I != E; ++I) {
+    Directive& D = **I;
+    unsigned LineNo1 = SourceMgr.getPresumedLineNumber(D.Location);
+    bool FoundOnce = false;
+
+    for (unsigned i = 0; i < D.Count; ++i) {
+      DiagList::iterator II, IE;
+      for (II = Right.begin(), IE = Right.end(); II != IE; ++II) {
+        unsigned LineNo2 = SourceMgr.getPresumedLineNumber(II->first);
+        if (LineNo1 != LineNo2)
+          continue;
+
+        const std::string &RightText = II->second;
+        if (D.Match(RightText))
+          break;
+      }
+      if (II == IE) {
+        if (D.Count == D.OneOrMoreCount) {
+          if (!FoundOnce)
+            LeftOnly.push_back(*I);
+          // We are only interested in at least one match, so exit the loop.
+          break;
+        }
+        // Not found.
+        LeftOnly.push_back(*I);
+      } else {
+        // Found. The same cannot be found twice.
+        Right.erase(II);
+        FoundOnce = true;
+      }
+    }
+  }
+  // Now all that's left in Right are those that were not matched.
+  unsigned num = PrintProblem(Diags, &SourceMgr, LeftOnly, Label, true);
+  num += PrintProblem(Diags, &SourceMgr, Right.begin(), Right.end(),
+                      Label, false);
+  return num;
+}
+
+/// CheckResults - This compares the expected results to those that
+/// were actually reported. It emits any discrepencies. Return "true" if there
+/// were problems. Return "false" otherwise.
+///
+static unsigned CheckResults(DiagnosticsEngine &Diags, SourceManager &SourceMgr,
+                             const TextDiagnosticBuffer &Buffer,
+                             ExpectedData &ED) {
+  // We want to capture the delta between what was expected and what was
+  // seen.
+  //
+  //   Expected \ Seen - set expected but not seen
+  //   Seen \ Expected - set seen but not expected
+  unsigned NumProblems = 0;
+
+  // See if there are error mismatches.
+  NumProblems += CheckLists(Diags, SourceMgr, "error", ED.Errors,
+                            Buffer.err_begin(), Buffer.err_end());
+
+  // See if there are warning mismatches.
+  NumProblems += CheckLists(Diags, SourceMgr, "warning", ED.Warnings,
+                            Buffer.warn_begin(), Buffer.warn_end());
+
+  // See if there are note mismatches.
+  NumProblems += CheckLists(Diags, SourceMgr, "note", ED.Notes,
+                            Buffer.note_begin(), Buffer.note_end());
+
+  return NumProblems;
+}
+
+void VerifyDiagnosticConsumer::CheckDiagnostics() {
+  ExpectedData ED;
+
+  // Ensure any diagnostics go to the primary client.
+  bool OwnsCurClient = Diags.ownsClient();
+  DiagnosticConsumer *CurClient = Diags.takeClient();
+  Diags.setClient(PrimaryClient, false);
+
+  // If we have a preprocessor, scan the source for expected diagnostic
+  // markers. If not then any diagnostics are unexpected.
+  if (CurrentPreprocessor) {
+    SourceManager &SM = CurrentPreprocessor->getSourceManager();
+    // Extract expected-error strings from main file.
+    FindExpectedDiags(*CurrentPreprocessor, ED, SM.getMainFileID());
+    // Only check for expectations in other diagnostic locations
+    // if they are not the main file (via ID or FileEntry) - the main
+    // file has already been looked at, and its expectations must not
+    // be added twice.
+    if (!FirstErrorFID.isInvalid() && FirstErrorFID != SM.getMainFileID()
+        && (!SM.getFileEntryForID(FirstErrorFID)
+            || (SM.getFileEntryForID(FirstErrorFID) !=
+                SM.getFileEntryForID(SM.getMainFileID())))) {
+      FindExpectedDiags(*CurrentPreprocessor, ED, FirstErrorFID);
+      FirstErrorFID = FileID();
+    }
+
+    // Check that the expected diagnostics occurred.
+    NumErrors += CheckResults(Diags, SM, *Buffer, ED);
+  } else {
+    NumErrors += (PrintProblem(Diags, 0,
+                               Buffer->err_begin(), Buffer->err_end(),
+                               "error", false) +
+                  PrintProblem(Diags, 0,
+                               Buffer->warn_begin(), Buffer->warn_end(),
+                               "warn", false) +
+                  PrintProblem(Diags, 0,
+                               Buffer->note_begin(), Buffer->note_end(),
+                               "note", false));
+  }
+
+  Diags.takeClient();
+  Diags.setClient(CurClient, OwnsCurClient);
+
+  // Reset the buffer, we have processed all the diagnostics in it.
+  Buffer.reset(new TextDiagnosticBuffer());
+}
+
+DiagnosticConsumer *
+VerifyDiagnosticConsumer::clone(DiagnosticsEngine &Diags) const {
+  if (!Diags.getClient())
+    Diags.setClient(PrimaryClient->clone(Diags));
+  
+  return new VerifyDiagnosticConsumer(Diags);
+}
+
+Directive* Directive::Create(bool RegexKind, const SourceLocation &Location,
+                             const std::string &Text, unsigned Count) {
+  if (RegexKind)
+    return new RegexDirective(Location, Text, Count);
+  return new StandardDirective(Location, Text, Count);
+}
diff --git a/clang/lib/Frontend/Warnings.cpp b/clang/lib/Frontend/Warnings.cpp
new file mode 100644
index 0000000..ec5fde0
--- /dev/null
+++ b/clang/lib/Frontend/Warnings.cpp
@@ -0,0 +1,191 @@
+//===--- Warnings.cpp - C-Language Front-end ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Command line warning options handler.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is responsible for handling all warning options. This includes
+// a number of -Wfoo options and their variants, which are driven by TableGen-
+// generated data, and the special cases -pedantic, -pedantic-errors, -w,
+// -Werror and -Wfatal-errors.
+//
+// Each warning option controls any number of actual warnings.
+// Given a warning option 'foo', the following are valid:
+//    -Wfoo, -Wno-foo, -Werror=foo, -Wfatal-errors=foo
+//
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Sema/SemaDiagnostic.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include <cstring>
+#include <utility>
+#include <algorithm>
+using namespace clang;
+
+// EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning
+// opts
+static void EmitUnknownDiagWarning(DiagnosticsEngine &Diags,
+                                  StringRef Prefix, StringRef Opt,
+                                  bool isPositive) {
+  StringRef Suggestion = DiagnosticIDs::getNearestWarningOption(Opt);
+  if (!Suggestion.empty())
+    Diags.Report(isPositive? diag::warn_unknown_warning_option_suggest :
+                             diag::warn_unknown_negative_warning_option_suggest)
+      << (Prefix.str() += Opt) << (Prefix.str() += Suggestion);
+  else
+    Diags.Report(isPositive? diag::warn_unknown_warning_option :
+                             diag::warn_unknown_negative_warning_option)
+      << (Prefix.str() += Opt);
+}
+
+void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
+                                  const DiagnosticOptions &Opts) {
+  Diags.setSuppressSystemWarnings(true);  // Default to -Wno-system-headers
+  Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
+  Diags.setShowOverloads(
+    static_cast<DiagnosticsEngine::OverloadsShown>(Opts.ShowOverloads));
+  
+  // Handle -ferror-limit
+  if (Opts.ErrorLimit)
+    Diags.setErrorLimit(Opts.ErrorLimit);
+  if (Opts.TemplateBacktraceLimit)
+    Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
+  if (Opts.ConstexprBacktraceLimit)
+    Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
+
+  // If -pedantic or -pedantic-errors was specified, then we want to map all
+  // extension diagnostics onto WARNING or ERROR unless the user has futz'd
+  // around with them explicitly.
+  if (Opts.PedanticErrors)
+    Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Error);
+  else if (Opts.Pedantic)
+    Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Warn);
+  else
+    Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Ignore);
+
+  llvm::SmallVector<diag::kind, 10> _Diags;
+  const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs =
+    Diags.getDiagnosticIDs();
+  // We parse the warning options twice.  The first pass sets diagnostic state,
+  // while the second pass reports warnings/errors.  This has the effect that
+  // we follow the more canonical "last option wins" paradigm when there are 
+  // conflicting options.
+  for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) {
+    bool SetDiagnostic = (Report == 0);
+    for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
+      StringRef Opt = Opts.Warnings[i];
+
+      // Treat -Wformat=0 as an alias for -Wno-format.
+      if (Opt == "format=0")
+        Opt = "no-format";
+
+      // Check to see if this warning starts with "no-", if so, this is a
+      // negative form of the option.
+      bool isPositive = true;
+      if (Opt.startswith("no-")) {
+        isPositive = false;
+        Opt = Opt.substr(3);
+      }
+
+      // Figure out how this option affects the warning.  If -Wfoo, map the
+      // diagnostic to a warning, if -Wno-foo, map it to ignore.
+      diag::Mapping Mapping = isPositive ? diag::MAP_WARNING : diag::MAP_IGNORE;
+      
+      // -Wsystem-headers is a special case, not driven by the option table.  It
+      // cannot be controlled with -Werror.
+      if (Opt == "system-headers") {
+        if (SetDiagnostic)
+          Diags.setSuppressSystemWarnings(!isPositive);
+        continue;
+      }
+      
+      // -Weverything is a special case as well.  It implicitly enables all
+      // warnings, including ones not explicitly in a warning group.
+      if (Opt == "everything") {
+        if (SetDiagnostic) {
+          if (isPositive) {
+            Diags.setEnableAllWarnings(true);
+          } else {
+            Diags.setEnableAllWarnings(false);
+            Diags.setMappingToAllDiagnostics(diag::MAP_IGNORE);
+          }
+        }
+        continue;
+      }
+      
+      // -Werror/-Wno-error is a special case, not controlled by the option 
+      // table. It also has the "specifier" form of -Werror=foo and -Werror-foo.
+      if (Opt.startswith("error")) {
+        StringRef Specifier;
+        if (Opt.size() > 5) {  // Specifier must be present.
+          if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
+            if (Report)
+              Diags.Report(diag::warn_unknown_warning_specifier)
+                << "-Werror" << ("-W" + Opt.str());
+            continue;
+          }
+          Specifier = Opt.substr(6);
+        }
+        
+        if (Specifier.empty()) {
+          if (SetDiagnostic)
+            Diags.setWarningsAsErrors(isPositive);
+          continue;
+        }
+        
+        if (SetDiagnostic) {
+          // Set the warning as error flag for this specifier.
+          Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive);
+        } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) {
+          EmitUnknownDiagWarning(Diags, "-Werror=", Specifier, isPositive);
+        }
+        continue;
+      }
+      
+      // -Wfatal-errors is yet another special case.
+      if (Opt.startswith("fatal-errors")) {
+        StringRef Specifier;
+        if (Opt.size() != 12) {
+          if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
+            if (Report)
+              Diags.Report(diag::warn_unknown_warning_specifier)
+                << "-Wfatal-errors" << ("-W" + Opt.str());
+            continue;
+          }
+          Specifier = Opt.substr(13);
+        }
+
+        if (Specifier.empty()) {
+          if (SetDiagnostic)
+            Diags.setErrorsAsFatal(isPositive);
+          continue;
+        }
+        
+        if (SetDiagnostic) {
+          // Set the error as fatal flag for this specifier.
+          Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive);
+        } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) {
+          EmitUnknownDiagWarning(Diags, "-Wfatal-errors=", Specifier,
+                                 isPositive);
+        }
+        continue;
+      }
+      
+      if (Report) {
+        if (DiagIDs->getDiagnosticsInGroup(Opt, _Diags))
+          EmitUnknownDiagWarning(Diags, "-W", Opt, isPositive);
+      } else {
+        Diags.setDiagnosticGroupMapping(Opt, Mapping);
+      }
+    }
+  }
+}