lib/Frontend/CompilerInstance.cpp

   1 //===--- CompilerInstance.cpp ---------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "clang/Frontend/CompilerInstance.h"
  11 #include "clang/Sema/Sema.h"
  12 #include "clang/AST/ASTConsumer.h"
  13 #include "clang/AST/ASTContext.h"
  14 #include "clang/Basic/Diagnostic.h"
  15 #include "clang/Basic/FileManager.h"
  16 #include "clang/Basic/SourceManager.h"
  17 #include "clang/Basic/TargetInfo.h"
  18 #include "clang/Basic/Version.h"
  19 #include "clang/Lex/HeaderSearch.h"
  20 #include "clang/Lex/Preprocessor.h"
  21 #include "clang/Lex/PTHManager.h"
  22 #include "clang/Frontend/ChainedDiagnosticClient.h"
  23 #include "clang/Frontend/FrontendAction.h"
  24 #include "clang/Frontend/FrontendDiagnostic.h"
  25 #include "clang/Frontend/LogDiagnosticPrinter.h"
  26 #include "clang/Frontend/TextDiagnosticPrinter.h"
  27 #include "clang/Frontend/VerifyDiagnosticsClient.h"
  28 #include "clang/Frontend/Utils.h"
  29 #include "clang/Serialization/ASTReader.h"
  30 #include "clang/Sema/CodeCompleteConsumer.h"
  31 #include "llvm/Support/FileSystem.h"
  32 #include "llvm/Support/MemoryBuffer.h"
  33 #include "llvm/Support/raw_ostream.h"
  34 #include "llvm/ADT/Statistic.h"
  35 #include "llvm/Support/Timer.h"
  36 #include "llvm/Support/Host.h"
  37 #include "llvm/Support/Path.h"
  38 #include "llvm/Support/Program.h"
  39 #include "llvm/Support/Signals.h"
  40 #include "llvm/Support/system_error.h"
  41 #include "llvm/Config/config.h"
  42 using namespace clang;
  43
  44 CompilerInstance::CompilerInstance()
  45   : Invocation(new CompilerInvocation()) {
  46 }
  47
  48 CompilerInstance::~CompilerInstance() {
  49 }
  50
  51 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
  52   Invocation = Value;
  53 }
  54
  55 void CompilerInstance::setDiagnostics(Diagnostic *Value) {
  56   Diagnostics = Value;
  57 }
  58
  59 void CompilerInstance::setTarget(TargetInfo *Value) {
  60   Target = Value;
  61 }
  62
  63 void CompilerInstance::setFileManager(FileManager *Value) {
  64   FileMgr = Value;
  65 }
  66
  67 void CompilerInstance::setSourceManager(SourceManager *Value) {
  68   SourceMgr = Value;
  69 }
  70
  71 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
  72
  73 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
  74
  75 void CompilerInstance::setSema(Sema *S) {
  76   TheSema.reset(S);
  77 }
  78
  79 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
  80   Consumer.reset(Value);
  81 }
  82
  83 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
  84   CompletionConsumer.reset(Value);
  85 }
  86
  87 // Diagnostics
  88 static void SetUpBuildDumpLog(const DiagnosticOptions &DiagOpts,
  89                               unsigned argc, const char* const *argv,
  90                               Diagnostic &Diags) {
  91   std::string ErrorInfo;
  92   llvm::OwningPtr<llvm::raw_ostream> OS(
  93     new llvm::raw_fd_ostream(DiagOpts.DumpBuildInformation.c_str(), ErrorInfo));
  94   if (!ErrorInfo.empty()) {
  95     Diags.Report(diag::err_fe_unable_to_open_logfile)
  96                  << DiagOpts.DumpBuildInformation << ErrorInfo;
  97     return;
  98   }
  99
 100   (*OS) << "clang -cc1 command line arguments: ";
 101   for (unsigned i = 0; i != argc; ++i)
 102     (*OS) << argv[i] << ' ';
 103   (*OS) << '\n';
 104
 105   // Chain in a diagnostic client which will log the diagnostics.
 106   DiagnosticClient *Logger =
 107     new TextDiagnosticPrinter(*OS.take(), DiagOpts, /*OwnsOutputStream=*/true);
 108   Diags.setClient(new ChainedDiagnosticClient(Diags.takeClient(), Logger));
 109 }
 110
 111 static void SetUpDiagnosticLog(const DiagnosticOptions &DiagOpts,
 112                                const CodeGenOptions *CodeGenOpts,
 113                                Diagnostic &Diags) {
 114   std::string ErrorInfo;
 115   bool OwnsStream = false;
 116   llvm::raw_ostream *OS = &llvm::errs();
 117   if (DiagOpts.DiagnosticLogFile != "-") {
 118     // Create the output stream.
 119     llvm::raw_fd_ostream *FileOS(
 120       new llvm::raw_fd_ostream(DiagOpts.DiagnosticLogFile.c_str(),
 121                                ErrorInfo, llvm::raw_fd_ostream::F_Append));
 122     if (!ErrorInfo.empty()) {
 123       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
 124         << DiagOpts.DumpBuildInformation << ErrorInfo;
 125     } else {
 126       FileOS->SetUnbuffered();
 127       FileOS->SetUseAtomicWrites(true);
 128       OS = FileOS;
 129       OwnsStream = true;
 130     }
 131   }
 132
 133   // Chain in the diagnostic client which will log the diagnostics.
 134   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
 135                                                           OwnsStream);
 136   if (CodeGenOpts)
 137     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
 138   Diags.setClient(new ChainedDiagnosticClient(Diags.takeClient(), Logger));
 139 }
 140
 141 void CompilerInstance::createDiagnostics(int Argc, const char* const *Argv,
 142                                          DiagnosticClient *Client) {
 143   Diagnostics = createDiagnostics(getDiagnosticOpts(), Argc, Argv, Client,
 144                                   &getCodeGenOpts());
 145 }
 146
 147 llvm::IntrusiveRefCntPtr<Diagnostic>
 148 CompilerInstance::createDiagnostics(const DiagnosticOptions &Opts,
 149                                     int Argc, const char* const *Argv,
 150                                     DiagnosticClient *Client,
 151                                     const CodeGenOptions *CodeGenOpts) {
 152   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 153   llvm::IntrusiveRefCntPtr<Diagnostic> Diags(new Diagnostic(DiagID));
 154
 155   // Create the diagnostic client for reporting errors or for
 156   // implementing -verify.
 157   if (Client)
 158     Diags->setClient(Client);
 159   else
 160     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
 161
 162   // Chain in -verify checker, if requested.
 163   if (Opts.VerifyDiagnostics)
 164     Diags->setClient(new VerifyDiagnosticsClient(*Diags, Diags->takeClient()));
 165
 166   // Chain in -diagnostic-log-file dumper, if requested.
 167   if (!Opts.DiagnosticLogFile.empty())
 168     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
 169
 170   if (!Opts.DumpBuildInformation.empty())
 171     SetUpBuildDumpLog(Opts, Argc, Argv, *Diags);
 172
 173   // Configure our handling of diagnostics.
 174   ProcessWarningOptions(*Diags, Opts);
 175
 176   return Diags;
 177 }
 178
 179 // File Manager
 180
 181 void CompilerInstance::createFileManager() {
 182   FileMgr = new FileManager(getFileSystemOpts());
 183 }
 184
 185 // Source Manager
 186
 187 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
 188   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
 189 }
 190
 191 // Preprocessor
 192
 193 void CompilerInstance::createPreprocessor() {
 194   PP = createPreprocessor(getDiagnostics(), getLangOpts(),
 195                           getPreprocessorOpts(), getHeaderSearchOpts(),
 196                           getDependencyOutputOpts(), getTarget(),
 197                           getFrontendOpts(), getSourceManager(),
 198                           getFileManager());
 199 }
 200
 201 Preprocessor *
 202 CompilerInstance::createPreprocessor(Diagnostic &Diags,
 203                                      const LangOptions &LangInfo,
 204                                      const PreprocessorOptions &PPOpts,
 205                                      const HeaderSearchOptions &HSOpts,
 206                                      const DependencyOutputOptions &DepOpts,
 207                                      const TargetInfo &Target,
 208                                      const FrontendOptions &FEOpts,
 209                                      SourceManager &SourceMgr,
 210                                      FileManager &FileMgr) {
 211   // Create a PTH manager if we are using some form of a token cache.
 212   PTHManager *PTHMgr = 0;
 213   if (!PPOpts.TokenCache.empty())
 214     PTHMgr = PTHManager::Create(PPOpts.TokenCache, Diags);
 215
 216   // Create the Preprocessor.
 217   HeaderSearch *HeaderInfo = new HeaderSearch(FileMgr);
 218   Preprocessor *PP = new Preprocessor(Diags, LangInfo, Target,
 219                                       SourceMgr, *HeaderInfo, PTHMgr,
 220                                       /*OwnsHeaderSearch=*/true);
 221
 222   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
 223   // That argument is used as the IdentifierInfoLookup argument to
 224   // IdentifierTable's ctor.
 225   if (PTHMgr) {
 226     PTHMgr->setPreprocessor(PP);
 227     PP->setPTHManager(PTHMgr);
 228   }
 229
 230   if (PPOpts.DetailedRecord)
 231     PP->createPreprocessingRecord(
 232                        PPOpts.DetailedRecordIncludesNestedMacroInstantiations);
 233
 234   InitializePreprocessor(*PP, PPOpts, HSOpts, FEOpts);
 235
 236   // Handle generating dependencies, if requested.
 237   if (!DepOpts.OutputFile.empty())
 238     AttachDependencyFileGen(*PP, DepOpts);
 239
 240   // Handle generating header include information, if requested.
 241   if (DepOpts.ShowHeaderIncludes)
 242     AttachHeaderIncludeGen(*PP);
 243   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
 244     llvm::StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
 245     if (OutputPath == "-")
 246       OutputPath = "";
 247     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
 248                            /*ShowDepth=*/false);
 249   }
 250
 251   return PP;
 252 }
 253
 254 // ASTContext
 255
 256 void CompilerInstance::createASTContext() {
 257   Preprocessor &PP = getPreprocessor();
 258   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
 259                            getTarget(), PP.getIdentifierTable(),
 260                            PP.getSelectorTable(), PP.getBuiltinInfo(),
 261                            /*size_reserve=*/ 0);
 262 }
 263
 264 // ExternalASTSource
 265
 266 void CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
 267                                                   bool DisablePCHValidation,
 268                                                   bool DisableStatCache,
 269                                                  void *DeserializationListener){
 270   llvm::OwningPtr<ExternalASTSource> Source;
 271   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
 272   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
 273                                           DisablePCHValidation,
 274                                           DisableStatCache,
 275                                           getPreprocessor(), getASTContext(),
 276                                           DeserializationListener,
 277                                           Preamble));
 278   getASTContext().setExternalSource(Source);
 279 }
 280
 281 ExternalASTSource *
 282 CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
 283                                              const std::string &Sysroot,
 284                                              bool DisablePCHValidation,
 285                                              bool DisableStatCache,
 286                                              Preprocessor &PP,
 287                                              ASTContext &Context,
 288                                              void *DeserializationListener,
 289                                              bool Preamble) {
 290   llvm::OwningPtr<ASTReader> Reader;
 291   Reader.reset(new ASTReader(PP, &Context,
 292                              Sysroot.empty() ? 0 : Sysroot.c_str(),
 293                              DisablePCHValidation, DisableStatCache));
 294
 295   Reader->setDeserializationListener(
 296             static_cast<ASTDeserializationListener *>(DeserializationListener));
 297   switch (Reader->ReadAST(Path,
 298                           Preamble ? ASTReader::Preamble : ASTReader::PCH)) {
 299   case ASTReader::Success:
 300     // Set the predefines buffer as suggested by the PCH reader. Typically, the
 301     // predefines buffer will be empty.
 302     PP.setPredefines(Reader->getSuggestedPredefines());
 303     return Reader.take();
 304
 305   case ASTReader::Failure:
 306     // Unrecoverable failure: don't even try to process the input file.
 307     break;
 308
 309   case ASTReader::IgnorePCH:
 310     // No suitable PCH file could be found. Return an error.
 311     break;
 312   }
 313
 314   return 0;
 315 }
 316
 317 // Code Completion
 318
 319 static bool EnableCodeCompletion(Preprocessor &PP,
 320                                  const std::string &Filename,
 321                                  unsigned Line,
 322                                  unsigned Column) {
 323   // Tell the source manager to chop off the given file at a specific
 324   // line and column.
 325   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
 326   if (!Entry) {
 327     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
 328       << Filename;
 329     return true;
 330   }
 331
 332   // Truncate the named file at the given line/column.
 333   PP.SetCodeCompletionPoint(Entry, Line, Column);
 334   return false;
 335 }
 336
 337 void CompilerInstance::createCodeCompletionConsumer() {
 338   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
 339   if (!CompletionConsumer) {
 340     CompletionConsumer.reset(
 341       createCodeCompletionConsumer(getPreprocessor(),
 342                                    Loc.FileName, Loc.Line, Loc.Column,
 343                                    getFrontendOpts().ShowMacrosInCodeCompletion,
 344                              getFrontendOpts().ShowCodePatternsInCodeCompletion,
 345                            getFrontendOpts().ShowGlobalSymbolsInCodeCompletion,
 346                                    llvm::outs()));
 347     if (!CompletionConsumer)
 348       return;
 349   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
 350                                   Loc.Line, Loc.Column)) {
 351     CompletionConsumer.reset();
 352     return;
 353   }
 354
 355   if (CompletionConsumer->isOutputBinary() &&
 356       llvm::sys::Program::ChangeStdoutToBinary()) {
 357     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
 358     CompletionConsumer.reset();
 359   }
 360 }
 361
 362 void CompilerInstance::createFrontendTimer() {
 363   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
 364 }
 365
 366 CodeCompleteConsumer *
 367 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
 368                                                const std::string &Filename,
 369                                                unsigned Line,
 370                                                unsigned Column,
 371                                                bool ShowMacros,
 372                                                bool ShowCodePatterns,
 373                                                bool ShowGlobals,
 374                                                llvm::raw_ostream &OS) {
 375   if (EnableCodeCompletion(PP, Filename, Line, Column))
 376     return 0;
 377
 378   // Set up the creation routine for code-completion.
 379   return new PrintingCodeCompleteConsumer(ShowMacros, ShowCodePatterns,
 380                                           ShowGlobals, OS);
 381 }
 382
 383 void CompilerInstance::createSema(bool CompleteTranslationUnit,
 384                                   CodeCompleteConsumer *CompletionConsumer) {
 385   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
 386                          CompleteTranslationUnit, CompletionConsumer));
 387 }
 388
 389 // Output Files
 390
 391 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
 392   assert(OutFile.OS && "Attempt to add empty stream to output list!");
 393   OutputFiles.push_back(OutFile);
 394 }
 395
 396 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
 397   for (std::list<OutputFile>::iterator
 398          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
 399     delete it->OS;
 400     if (!it->TempFilename.empty()) {
 401       if (EraseFiles) {
 402         bool existed;
 403         llvm::sys::fs::remove(it->TempFilename, existed);
 404       } else {
 405         llvm::SmallString<128> NewOutFile(it->Filename);
 406
 407         // If '-working-directory' was passed, the output filename should be
 408         // relative to that.
 409         FileMgr->FixupRelativePath(NewOutFile);
 410         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
 411                                                         NewOutFile.str())) {
 412           getDiagnostics().Report(diag::err_fe_unable_to_rename_temp)
 413             << it->TempFilename << it->Filename << ec.message();
 414
 415           bool existed;
 416           llvm::sys::fs::remove(it->TempFilename, existed);
 417         }
 418       }
 419     } else if (!it->Filename.empty() && EraseFiles)
 420       llvm::sys::Path(it->Filename).eraseFromDisk();
 421
 422   }
 423   OutputFiles.clear();
 424 }
 425
 426 llvm::raw_fd_ostream *
 427 CompilerInstance::createDefaultOutputFile(bool Binary,
 428                                           llvm::StringRef InFile,
 429                                           llvm::StringRef Extension) {
 430   return createOutputFile(getFrontendOpts().OutputFile, Binary,
 431                           /*RemoveFileOnSignal=*/true, InFile, Extension);
 432 }
 433
 434 llvm::raw_fd_ostream *
 435 CompilerInstance::createOutputFile(llvm::StringRef OutputPath,
 436                                    bool Binary, bool RemoveFileOnSignal,
 437                                    llvm::StringRef InFile,
 438                                    llvm::StringRef Extension) {
 439   std::string Error, OutputPathName, TempPathName;
 440   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
 441                                               RemoveFileOnSignal,
 442                                               InFile, Extension,
 443                                               &OutputPathName,
 444                                               &TempPathName);
 445   if (!OS) {
 446     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
 447       << OutputPath << Error;
 448     return 0;
 449   }
 450
 451   // Add the output file -- but don't try to remove "-", since this means we are
 452   // using stdin.
 453   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
 454                 TempPathName, OS));
 455
 456   return OS;
 457 }
 458
 459 llvm::raw_fd_ostream *
 460 CompilerInstance::createOutputFile(llvm::StringRef OutputPath,
 461                                    std::string &Error,
 462                                    bool Binary,
 463                                    bool RemoveFileOnSignal,
 464                                    llvm::StringRef InFile,
 465                                    llvm::StringRef Extension,
 466                                    std::string *ResultPathName,
 467                                    std::string *TempPathName) {
 468   std::string OutFile, TempFile;
 469   if (!OutputPath.empty()) {
 470     OutFile = OutputPath;
 471   } else if (InFile == "-") {
 472     OutFile = "-";
 473   } else if (!Extension.empty()) {
 474     llvm::sys::Path Path(InFile);
 475     Path.eraseSuffix();
 476     Path.appendSuffix(Extension);
 477     OutFile = Path.str();
 478   } else {
 479     OutFile = "-";
 480   }
 481
 482   if (OutFile != "-") {
 483     llvm::sys::Path OutPath(OutFile);
 484     // Only create the temporary if we can actually write to OutPath, otherwise
 485     // we want to fail early.
 486     bool Exists;
 487     if ((llvm::sys::fs::exists(OutPath.str(), Exists) || !Exists) ||
 488         (OutPath.isRegularFile() && OutPath.canWrite())) {
 489       // Create a temporary file.
 490       llvm::sys::Path TempPath(OutFile);
 491       if (!TempPath.createTemporaryFileOnDisk())
 492         TempFile = TempPath.str();
 493     }
 494   }
 495
 496   std::string OSFile = OutFile;
 497   if (!TempFile.empty())
 498     OSFile = TempFile;
 499
 500   llvm::OwningPtr<llvm::raw_fd_ostream> OS(
 501     new llvm::raw_fd_ostream(OSFile.c_str(), Error,
 502                              (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
 503   if (!Error.empty())
 504     return 0;
 505
 506   // Make sure the out stream file gets removed if we crash.
 507   if (RemoveFileOnSignal)
 508     llvm::sys::RemoveFileOnSignal(llvm::sys::Path(OSFile));
 509
 510   if (ResultPathName)
 511     *ResultPathName = OutFile;
 512   if (TempPathName)
 513     *TempPathName = TempFile;
 514
 515   return OS.take();
 516 }
 517
 518 // Initialization Utilities
 519
 520 bool CompilerInstance::InitializeSourceManager(llvm::StringRef InputFile) {
 521   return InitializeSourceManager(InputFile, getDiagnostics(), getFileManager(),
 522                                  getSourceManager(), getFrontendOpts());
 523 }
 524
 525 bool CompilerInstance::InitializeSourceManager(llvm::StringRef InputFile,
 526                                                Diagnostic &Diags,
 527                                                FileManager &FileMgr,
 528                                                SourceManager &SourceMgr,
 529                                                const FrontendOptions &Opts) {
 530   // Figure out where to get and map in the main file, unless it's already
 531   // been created (e.g., by a precompiled preamble).
 532   if (!SourceMgr.getMainFileID().isInvalid()) {
 533     // Do nothing: the main file has already been set.
 534   } else if (InputFile != "-") {
 535     const FileEntry *File = FileMgr.getFile(InputFile);
 536     if (!File) {
 537       Diags.Report(diag::err_fe_error_reading) << InputFile;
 538       return false;
 539     }
 540     SourceMgr.createMainFileID(File);
 541   } else {
 542     llvm::OwningPtr<llvm::MemoryBuffer> SB;
 543     if (llvm::MemoryBuffer::getSTDIN(SB)) {
 544       // FIXME: Give ec.message() in this diag.
 545       Diags.Report(diag::err_fe_error_reading_stdin);
 546       return false;
 547     }
 548     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
 549                                                    SB->getBufferSize(), 0);
 550     SourceMgr.createMainFileID(File);
 551     SourceMgr.overrideFileContents(File, SB.take());
 552   }
 553
 554   assert(!SourceMgr.getMainFileID().isInvalid() &&
 555          "Couldn't establish MainFileID!");
 556   return true;
 557 }
 558
 559 // High-Level Operations
 560
 561 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
 562   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
 563   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
 564   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
 565
 566   // FIXME: Take this as an argument, once all the APIs we used have moved to
 567   // taking it as an input instead of hard-coding llvm::errs.
 568   llvm::raw_ostream &OS = llvm::errs();
 569
 570   // Create the target instance.
 571   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), getTargetOpts()));
 572   if (!hasTarget())
 573     return false;
 574
 575   // Inform the target of the language options.
 576   //
 577   // FIXME: We shouldn't need to do this, the target should be immutable once
 578   // created. This complexity should be lifted elsewhere.
 579   getTarget().setForcedLangOptions(getLangOpts());
 580
 581   // Validate/process some options.
 582   if (getHeaderSearchOpts().Verbose)
 583     OS << "clang -cc1 version " CLANG_VERSION_STRING
 584        << " based upon " << PACKAGE_STRING
 585        << " hosted on " << llvm::sys::getHostTriple() << "\n";
 586
 587   if (getFrontendOpts().ShowTimers)
 588     createFrontendTimer();
 589
 590   if (getFrontendOpts().ShowStats)
 591     llvm::EnableStatistics();
 592
 593   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
 594     const std::string &InFile = getFrontendOpts().Inputs[i].second;
 595
 596     // Reset the ID tables if we are reusing the SourceManager.
 597     if (hasSourceManager())
 598       getSourceManager().clearIDTables();
 599
 600     if (Act.BeginSourceFile(*this, InFile, getFrontendOpts().Inputs[i].first)) {
 601       Act.Execute();
 602       Act.EndSourceFile();
 603     }
 604   }
 605
 606   if (getDiagnosticOpts().ShowCarets) {
 607     // We can have multiple diagnostics sharing one diagnostic client.
 608     // Get the total number of warnings/errors from the client.
 609     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
 610     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
 611
 612     if (NumWarnings)
 613       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
 614     if (NumWarnings && NumErrors)
 615       OS << " and ";
 616     if (NumErrors)
 617       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
 618     if (NumWarnings || NumErrors)
 619       OS << " generated.\n";
 620   }
 621
 622   if (getFrontendOpts().ShowStats && hasFileManager()) {
 623     getFileManager().PrintStats();
 624     OS << "\n";
 625   }
 626
 627   return !getDiagnostics().getClient()->getNumErrors();
 628 }
 629
 630