Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 1101 insertions, 0 deletions

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;
+}