CompilerInstance.cpp revision 6f2e23b25d9be365266be43ffa1cf6f850b6027e 
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/AST/ASTConsumer.h"
12#include "clang/AST/ASTContext.h"
13#include "clang/AST/Decl.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/Frontend/ChainedDiagnosticConsumer.h"
20#include "clang/Frontend/FrontendAction.h"
21#include "clang/Frontend/FrontendActions.h"
22#include "clang/Frontend/FrontendDiagnostic.h"
23#include "clang/Frontend/LogDiagnosticPrinter.h"
24#include "clang/Frontend/SerializedDiagnosticPrinter.h"
25#include "clang/Frontend/TextDiagnosticPrinter.h"
26#include "clang/Frontend/Utils.h"
27#include "clang/Frontend/VerifyDiagnosticConsumer.h"
28#include "clang/Lex/HeaderSearch.h"
29#include "clang/Lex/PTHManager.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/CodeCompleteConsumer.h"
32#include "clang/Sema/Sema.h"
33#include "clang/Serialization/ASTReader.h"
34#include "llvm/ADT/Statistic.h"
35#include "llvm/Config/config.h"
36#include "llvm/Support/CrashRecoveryContext.h"
37#include "llvm/Support/FileSystem.h"
38#include "llvm/Support/Host.h"
39#include "llvm/Support/LockFileManager.h"
40#include "llvm/Support/MemoryBuffer.h"
41#include "llvm/Support/Path.h"
42#include "llvm/Support/Program.h"
43#include "llvm/Support/Signals.h"
44#include "llvm/Support/Timer.h"
45#include "llvm/Support/raw_ostream.h"
46#include "llvm/Support/system_error.h"
47#include <sys/stat.h>
48#include <time.h>
49
50using namespace clang;
51
52CompilerInstance::CompilerInstance()
53  : Invocation(new CompilerInvocation()), ModuleManager(0),
54    BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
55}
56
57CompilerInstance::~CompilerInstance() {
58  assert(OutputFiles.empty() && "Still output files in flight?");
59}
60
61void CompilerInstance::setInvocation(CompilerInvocation *Value) {
62  Invocation = Value;
63}
64
65bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
66  return (BuildGlobalModuleIndex ||
67          (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
68           getFrontendOpts().GenerateGlobalModuleIndex)) &&
69         !ModuleBuildFailed;
70}
71
72void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
73  Diagnostics = Value;
74}
75
76void CompilerInstance::setTarget(TargetInfo *Value) {
77  Target = Value;
78}
79
80void CompilerInstance::setFileManager(FileManager *Value) {
81  FileMgr = Value;
82}
83
84void CompilerInstance::setSourceManager(SourceManager *Value) {
85  SourceMgr = Value;
86}
87
88void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
89
90void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
91
92void CompilerInstance::setSema(Sema *S) {
93  TheSema.reset(S);
94}
95
96void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
97  Consumer.reset(Value);
98}
99
100void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
101  CompletionConsumer.reset(Value);
102}
103
104// Diagnostics
105static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
106                               const CodeGenOptions *CodeGenOpts,
107                               DiagnosticsEngine &Diags) {
108  std::string ErrorInfo;
109  bool OwnsStream = false;
110  raw_ostream *OS = &llvm::errs();
111  if (DiagOpts->DiagnosticLogFile != "-") {
112    // Create the output stream.
113    llvm::raw_fd_ostream *FileOS(
114      new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(),
115                               ErrorInfo, llvm::raw_fd_ostream::F_Append));
116    if (!ErrorInfo.empty()) {
117      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
118        << DiagOpts->DiagnosticLogFile << ErrorInfo;
119    } else {
120      FileOS->SetUnbuffered();
121      FileOS->SetUseAtomicWrites(true);
122      OS = FileOS;
123      OwnsStream = true;
124    }
125  }
126
127  // Chain in the diagnostic client which will log the diagnostics.
128  LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
129                                                          OwnsStream);
130  if (CodeGenOpts)
131    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
132  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
133}
134
135static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
136                                       DiagnosticsEngine &Diags,
137                                       StringRef OutputFile) {
138  std::string ErrorInfo;
139  OwningPtr<llvm::raw_fd_ostream> OS;
140  OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
141                                    llvm::raw_fd_ostream::F_Binary));
142
143  if (!ErrorInfo.empty()) {
144    Diags.Report(diag::warn_fe_serialized_diag_failure)
145      << OutputFile << ErrorInfo;
146    return;
147  }
148
149  DiagnosticConsumer *SerializedConsumer =
150    clang::serialized_diags::create(OS.take(), DiagOpts);
151
152
153  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
154                                                SerializedConsumer));
155}
156
157void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
158                                         bool ShouldOwnClient) {
159  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
160                                  ShouldOwnClient, &getCodeGenOpts());
161}
162
163IntrusiveRefCntPtr<DiagnosticsEngine>
164CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
165                                    DiagnosticConsumer *Client,
166                                    bool ShouldOwnClient,
167                                    const CodeGenOptions *CodeGenOpts) {
168  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
169  IntrusiveRefCntPtr<DiagnosticsEngine>
170      Diags(new DiagnosticsEngine(DiagID, Opts));
171
172  // Create the diagnostic client for reporting errors or for
173  // implementing -verify.
174  if (Client) {
175    Diags->setClient(Client, ShouldOwnClient);
176  } else
177    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
178
179  // Chain in -verify checker, if requested.
180  if (Opts->VerifyDiagnostics)
181    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
182
183  // Chain in -diagnostic-log-file dumper, if requested.
184  if (!Opts->DiagnosticLogFile.empty())
185    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
186
187  if (!Opts->DiagnosticSerializationFile.empty())
188    SetupSerializedDiagnostics(Opts, *Diags,
189                               Opts->DiagnosticSerializationFile);
190
191  // Configure our handling of diagnostics.
192  ProcessWarningOptions(*Diags, *Opts);
193
194  return Diags;
195}
196
197// File Manager
198
199void CompilerInstance::createFileManager() {
200  FileMgr = new FileManager(getFileSystemOpts());
201}
202
203// Source Manager
204
205void CompilerInstance::createSourceManager(FileManager &FileMgr) {
206  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
207}
208
209// Preprocessor
210
211void CompilerInstance::createPreprocessor() {
212  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
213
214  // Create a PTH manager if we are using some form of a token cache.
215  PTHManager *PTHMgr = 0;
216  if (!PPOpts.TokenCache.empty())
217    PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
218
219  // Create the Preprocessor.
220  HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
221                                              getFileManager(),
222                                              getDiagnostics(),
223                                              getLangOpts(),
224                                              &getTarget());
225  PP = new Preprocessor(&getPreprocessorOpts(),
226                        getDiagnostics(), getLangOpts(), &getTarget(),
227                        getSourceManager(), *HeaderInfo, *this, PTHMgr,
228                        /*OwnsHeaderSearch=*/true);
229
230  // Note that this is different then passing PTHMgr to Preprocessor's ctor.
231  // That argument is used as the IdentifierInfoLookup argument to
232  // IdentifierTable's ctor.
233  if (PTHMgr) {
234    PTHMgr->setPreprocessor(&*PP);
235    PP->setPTHManager(PTHMgr);
236  }
237
238  if (PPOpts.DetailedRecord)
239    PP->createPreprocessingRecord();
240
241  InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
242
243  PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
244
245  // Set up the module path, including the hash for the
246  // module-creation options.
247  SmallString<256> SpecificModuleCache(
248                           getHeaderSearchOpts().ModuleCachePath);
249  if (!getHeaderSearchOpts().DisableModuleHash)
250    llvm::sys::path::append(SpecificModuleCache,
251                            getInvocation().getModuleHash());
252  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
253
254  // Handle generating dependencies, if requested.
255  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
256  if (!DepOpts.OutputFile.empty())
257    AttachDependencyFileGen(*PP, DepOpts);
258  if (!DepOpts.DOTOutputFile.empty())
259    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
260                             getHeaderSearchOpts().Sysroot);
261
262
263  // Handle generating header include information, if requested.
264  if (DepOpts.ShowHeaderIncludes)
265    AttachHeaderIncludeGen(*PP);
266  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
267    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
268    if (OutputPath == "-")
269      OutputPath = "";
270    AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
271                           /*ShowDepth=*/false);
272  }
273}
274
275// ASTContext
276
277void CompilerInstance::createASTContext() {
278  Preprocessor &PP = getPreprocessor();
279  Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
280                           &getTarget(), PP.getIdentifierTable(),
281                           PP.getSelectorTable(), PP.getBuiltinInfo(),
282                           /*size_reserve=*/ 0);
283}
284
285// ExternalASTSource
286
287void CompilerInstance::createPCHExternalASTSource(StringRef Path,
288                                                  bool DisablePCHValidation,
289                                                bool AllowPCHWithCompilerErrors,
290                                                 void *DeserializationListener){
291  OwningPtr<ExternalASTSource> Source;
292  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
293  Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
294                                          DisablePCHValidation,
295                                          AllowPCHWithCompilerErrors,
296                                          getPreprocessor(), getASTContext(),
297                                          DeserializationListener,
298                                          Preamble,
299                                       getFrontendOpts().UseGlobalModuleIndex));
300  ModuleManager = static_cast<ASTReader*>(Source.get());
301  getASTContext().setExternalSource(Source);
302}
303
304ExternalASTSource *
305CompilerInstance::createPCHExternalASTSource(StringRef Path,
306                                             const std::string &Sysroot,
307                                             bool DisablePCHValidation,
308                                             bool AllowPCHWithCompilerErrors,
309                                             Preprocessor &PP,
310                                             ASTContext &Context,
311                                             void *DeserializationListener,
312                                             bool Preamble,
313                                             bool UseGlobalModuleIndex) {
314  OwningPtr<ASTReader> Reader;
315  Reader.reset(new ASTReader(PP, Context,
316                             Sysroot.empty() ? "" : Sysroot.c_str(),
317                             DisablePCHValidation,
318                             AllowPCHWithCompilerErrors,
319                             UseGlobalModuleIndex));
320
321  Reader->setDeserializationListener(
322            static_cast<ASTDeserializationListener *>(DeserializationListener));
323  switch (Reader->ReadAST(Path,
324                          Preamble ? serialization::MK_Preamble
325                                   : serialization::MK_PCH,
326                          SourceLocation(),
327                          ASTReader::ARR_None)) {
328  case ASTReader::Success:
329    // Set the predefines buffer as suggested by the PCH reader. Typically, the
330    // predefines buffer will be empty.
331    PP.setPredefines(Reader->getSuggestedPredefines());
332    return Reader.take();
333
334  case ASTReader::Failure:
335    // Unrecoverable failure: don't even try to process the input file.
336    break;
337
338  case ASTReader::Missing:
339  case ASTReader::OutOfDate:
340  case ASTReader::VersionMismatch:
341  case ASTReader::ConfigurationMismatch:
342  case ASTReader::HadErrors:
343    // No suitable PCH file could be found. Return an error.
344    break;
345  }
346
347  return 0;
348}
349
350// Code Completion
351
352static bool EnableCodeCompletion(Preprocessor &PP,
353                                 const std::string &Filename,
354                                 unsigned Line,
355                                 unsigned Column) {
356  // Tell the source manager to chop off the given file at a specific
357  // line and column.
358  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
359  if (!Entry) {
360    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
361      << Filename;
362    return true;
363  }
364
365  // Truncate the named file at the given line/column.
366  PP.SetCodeCompletionPoint(Entry, Line, Column);
367  return false;
368}
369
370void CompilerInstance::createCodeCompletionConsumer() {
371  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
372  if (!CompletionConsumer) {
373    setCodeCompletionConsumer(
374      createCodeCompletionConsumer(getPreprocessor(),
375                                   Loc.FileName, Loc.Line, Loc.Column,
376                                   getFrontendOpts().CodeCompleteOpts,
377                                   llvm::outs()));
378    if (!CompletionConsumer)
379      return;
380  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
381                                  Loc.Line, Loc.Column)) {
382    setCodeCompletionConsumer(0);
383    return;
384  }
385
386  if (CompletionConsumer->isOutputBinary() &&
387      llvm::sys::ChangeStdoutToBinary()) {
388    getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
389    setCodeCompletionConsumer(0);
390  }
391}
392
393void CompilerInstance::createFrontendTimer() {
394  FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
395}
396
397CodeCompleteConsumer *
398CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
399                                               const std::string &Filename,
400                                               unsigned Line,
401                                               unsigned Column,
402                                               const CodeCompleteOptions &Opts,
403                                               raw_ostream &OS) {
404  if (EnableCodeCompletion(PP, Filename, Line, Column))
405    return 0;
406
407  // Set up the creation routine for code-completion.
408  return new PrintingCodeCompleteConsumer(Opts, OS);
409}
410
411void CompilerInstance::createSema(TranslationUnitKind TUKind,
412                                  CodeCompleteConsumer *CompletionConsumer) {
413  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
414                         TUKind, CompletionConsumer));
415}
416
417// Output Files
418
419void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
420  assert(OutFile.OS && "Attempt to add empty stream to output list!");
421  OutputFiles.push_back(OutFile);
422}
423
424void CompilerInstance::clearOutputFiles(bool EraseFiles) {
425  for (std::list<OutputFile>::iterator
426         it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
427    delete it->OS;
428    if (!it->TempFilename.empty()) {
429      if (EraseFiles) {
430        bool existed;
431        llvm::sys::fs::remove(it->TempFilename, existed);
432      } else {
433        SmallString<128> NewOutFile(it->Filename);
434
435        // If '-working-directory' was passed, the output filename should be
436        // relative to that.
437        FileMgr->FixupRelativePath(NewOutFile);
438        if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
439                                                        NewOutFile.str())) {
440          getDiagnostics().Report(diag::err_unable_to_rename_temp)
441            << it->TempFilename << it->Filename << ec.message();
442
443          bool existed;
444          llvm::sys::fs::remove(it->TempFilename, existed);
445        }
446      }
447    } else if (!it->Filename.empty() && EraseFiles)
448      llvm::sys::Path(it->Filename).eraseFromDisk();
449
450  }
451  OutputFiles.clear();
452}
453
454llvm::raw_fd_ostream *
455CompilerInstance::createDefaultOutputFile(bool Binary,
456                                          StringRef InFile,
457                                          StringRef Extension) {
458  return createOutputFile(getFrontendOpts().OutputFile, Binary,
459                          /*RemoveFileOnSignal=*/true, InFile, Extension,
460                          /*UseTemporary=*/true);
461}
462
463llvm::raw_fd_ostream *
464CompilerInstance::createOutputFile(StringRef OutputPath,
465                                   bool Binary, bool RemoveFileOnSignal,
466                                   StringRef InFile,
467                                   StringRef Extension,
468                                   bool UseTemporary,
469                                   bool CreateMissingDirectories) {
470  std::string Error, OutputPathName, TempPathName;
471  llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
472                                              RemoveFileOnSignal,
473                                              InFile, Extension,
474                                              UseTemporary,
475                                              CreateMissingDirectories,
476                                              &OutputPathName,
477                                              &TempPathName);
478  if (!OS) {
479    getDiagnostics().Report(diag::err_fe_unable_to_open_output)
480      << OutputPath << Error;
481    return 0;
482  }
483
484  // Add the output file -- but don't try to remove "-", since this means we are
485  // using stdin.
486  addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
487                TempPathName, OS));
488
489  return OS;
490}
491
492llvm::raw_fd_ostream *
493CompilerInstance::createOutputFile(StringRef OutputPath,
494                                   std::string &Error,
495                                   bool Binary,
496                                   bool RemoveFileOnSignal,
497                                   StringRef InFile,
498                                   StringRef Extension,
499                                   bool UseTemporary,
500                                   bool CreateMissingDirectories,
501                                   std::string *ResultPathName,
502                                   std::string *TempPathName) {
503  assert((!CreateMissingDirectories || UseTemporary) &&
504         "CreateMissingDirectories is only allowed when using temporary files");
505
506  std::string OutFile, TempFile;
507  if (!OutputPath.empty()) {
508    OutFile = OutputPath;
509  } else if (InFile == "-") {
510    OutFile = "-";
511  } else if (!Extension.empty()) {
512    llvm::sys::Path Path(InFile);
513    Path.eraseSuffix();
514    Path.appendSuffix(Extension);
515    OutFile = Path.str();
516  } else {
517    OutFile = "-";
518  }
519
520  OwningPtr<llvm::raw_fd_ostream> OS;
521  std::string OSFile;
522
523  if (UseTemporary && OutFile != "-") {
524    // Only create the temporary if the parent directory exists (or create
525    // missing directories is true) and we can actually write to OutPath,
526    // otherwise we want to fail early.
527    SmallString<256> AbsPath(OutputPath);
528    llvm::sys::fs::make_absolute(AbsPath);
529    llvm::sys::Path OutPath(AbsPath);
530    bool ParentExists = false;
531    if (llvm::sys::fs::exists(llvm::sys::path::parent_path(AbsPath.str()),
532                              ParentExists))
533      ParentExists = false;
534    bool Exists;
535    if ((CreateMissingDirectories || ParentExists) &&
536        ((llvm::sys::fs::exists(AbsPath.str(), Exists) || !Exists) ||
537         (OutPath.isRegularFile() && OutPath.canWrite()))) {
538      // Create a temporary file.
539      SmallString<128> TempPath;
540      TempPath = OutFile;
541      TempPath += "-%%%%%%%%";
542      int fd;
543      if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
544                                     /*makeAbsolute=*/false, 0664)
545          == llvm::errc::success) {
546        OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
547        OSFile = TempFile = TempPath.str();
548      }
549    }
550  }
551
552  if (!OS) {
553    OSFile = OutFile;
554    OS.reset(
555      new llvm::raw_fd_ostream(OSFile.c_str(), Error,
556                               (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
557    if (!Error.empty())
558      return 0;
559  }
560
561  // Make sure the out stream file gets removed if we crash.
562  if (RemoveFileOnSignal)
563    llvm::sys::RemoveFileOnSignal(OSFile);
564
565  if (ResultPathName)
566    *ResultPathName = OutFile;
567  if (TempPathName)
568    *TempPathName = TempFile;
569
570  return OS.take();
571}
572
573// Initialization Utilities
574
575bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
576  return InitializeSourceManager(Input, getDiagnostics(),
577                                 getFileManager(), getSourceManager(),
578                                 getFrontendOpts());
579}
580
581bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
582                                               DiagnosticsEngine &Diags,
583                                               FileManager &FileMgr,
584                                               SourceManager &SourceMgr,
585                                               const FrontendOptions &Opts) {
586  SrcMgr::CharacteristicKind
587    Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
588
589  if (Input.isBuffer()) {
590    SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
591    assert(!SourceMgr.getMainFileID().isInvalid() &&
592           "Couldn't establish MainFileID!");
593    return true;
594  }
595
596  StringRef InputFile = Input.getFile();
597
598  // Figure out where to get and map in the main file.
599  if (InputFile != "-") {
600    const FileEntry *File = FileMgr.getFile(InputFile);
601    if (!File) {
602      Diags.Report(diag::err_fe_error_reading) << InputFile;
603      return false;
604    }
605
606    // The natural SourceManager infrastructure can't currently handle named
607    // pipes, but we would at least like to accept them for the main
608    // file. Detect them here, read them with the more generic MemoryBuffer
609    // function, and simply override their contents as we do for STDIN.
610    if (File->isNamedPipe()) {
611      OwningPtr<llvm::MemoryBuffer> MB;
612      if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
613        Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
614        return false;
615      }
616
617      // Create a new virtual file that will have the correct size.
618      File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
619      SourceMgr.overrideFileContents(File, MB.take());
620    }
621
622    SourceMgr.createMainFileID(File, Kind);
623  } else {
624    OwningPtr<llvm::MemoryBuffer> SB;
625    if (llvm::MemoryBuffer::getSTDIN(SB)) {
626      // FIXME: Give ec.message() in this diag.
627      Diags.Report(diag::err_fe_error_reading_stdin);
628      return false;
629    }
630    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
631                                                   SB->getBufferSize(), 0);
632    SourceMgr.createMainFileID(File, Kind);
633    SourceMgr.overrideFileContents(File, SB.take());
634  }
635
636  assert(!SourceMgr.getMainFileID().isInvalid() &&
637         "Couldn't establish MainFileID!");
638  return true;
639}
640
641// High-Level Operations
642
643bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
644  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
645  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
646  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
647
648  // FIXME: Take this as an argument, once all the APIs we used have moved to
649  // taking it as an input instead of hard-coding llvm::errs.
650  raw_ostream &OS = llvm::errs();
651
652  // Create the target instance.
653  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
654  if (!hasTarget())
655    return false;
656
657  // Inform the target of the language options.
658  //
659  // FIXME: We shouldn't need to do this, the target should be immutable once
660  // created. This complexity should be lifted elsewhere.
661  getTarget().setForcedLangOptions(getLangOpts());
662
663  // rewriter project will change target built-in bool type from its default.
664  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
665    getTarget().noSignedCharForObjCBool();
666
667  // Validate/process some options.
668  if (getHeaderSearchOpts().Verbose)
669    OS << "clang -cc1 version " CLANG_VERSION_STRING
670       << " based upon " << PACKAGE_STRING
671       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
672
673  if (getFrontendOpts().ShowTimers)
674    createFrontendTimer();
675
676  if (getFrontendOpts().ShowStats)
677    llvm::EnableStatistics();
678
679  for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
680    // Reset the ID tables if we are reusing the SourceManager.
681    if (hasSourceManager())
682      getSourceManager().clearIDTables();
683
684    if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
685      Act.Execute();
686      Act.EndSourceFile();
687    }
688  }
689
690  // Notify the diagnostic client that all files were processed.
691  getDiagnostics().getClient()->finish();
692
693  if (getDiagnosticOpts().ShowCarets) {
694    // We can have multiple diagnostics sharing one diagnostic client.
695    // Get the total number of warnings/errors from the client.
696    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
697    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
698
699    if (NumWarnings)
700      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
701    if (NumWarnings && NumErrors)
702      OS << " and ";
703    if (NumErrors)
704      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
705    if (NumWarnings || NumErrors)
706      OS << " generated.\n";
707  }
708
709  if (getFrontendOpts().ShowStats && hasFileManager()) {
710    getFileManager().PrintStats();
711    OS << "\n";
712  }
713
714  return !getDiagnostics().getClient()->getNumErrors();
715}
716
717/// \brief Determine the appropriate source input kind based on language
718/// options.
719static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
720  if (LangOpts.OpenCL)
721    return IK_OpenCL;
722  if (LangOpts.CUDA)
723    return IK_CUDA;
724  if (LangOpts.ObjC1)
725    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
726  return LangOpts.CPlusPlus? IK_CXX : IK_C;
727}
728
729namespace {
730  struct CompileModuleMapData {
731    CompilerInstance &Instance;
732    GenerateModuleAction &CreateModuleAction;
733  };
734}
735
736/// \brief Helper function that executes the module-generating action under
737/// a crash recovery context.
738static void doCompileMapModule(void *UserData) {
739  CompileModuleMapData &Data
740    = *reinterpret_cast<CompileModuleMapData *>(UserData);
741  Data.Instance.ExecuteAction(Data.CreateModuleAction);
742}
743
744namespace {
745  /// \brief Function object that checks with the given macro definition should
746  /// be removed, because it is one of the ignored macros.
747  class RemoveIgnoredMacro {
748    const HeaderSearchOptions &HSOpts;
749
750  public:
751    explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
752      : HSOpts(HSOpts) { }
753
754    bool operator()(const std::pair<std::string, bool> &def) const {
755      StringRef MacroDef = def.first;
756      return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
757    }
758  };
759}
760
761/// \brief Compile a module file for the given module, using the options
762/// provided by the importing compiler instance.
763static void compileModule(CompilerInstance &ImportingInstance,
764                          SourceLocation ImportLoc,
765                          Module *Module,
766                          StringRef ModuleFileName) {
767  llvm::LockFileManager Locked(ModuleFileName);
768  switch (Locked) {
769  case llvm::LockFileManager::LFS_Error:
770    return;
771
772  case llvm::LockFileManager::LFS_Owned:
773    // We're responsible for building the module ourselves. Do so below.
774    break;
775
776  case llvm::LockFileManager::LFS_Shared:
777    // Someone else is responsible for building the module. Wait for them to
778    // finish.
779    Locked.waitForUnlock();
780    return;
781  }
782
783  ModuleMap &ModMap
784    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
785
786  // Construct a compiler invocation for creating this module.
787  IntrusiveRefCntPtr<CompilerInvocation> Invocation
788    (new CompilerInvocation(ImportingInstance.getInvocation()));
789
790  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
791
792  // For any options that aren't intended to affect how a module is built,
793  // reset them to their default values.
794  Invocation->getLangOpts()->resetNonModularOptions();
795  PPOpts.resetNonModularOptions();
796
797  // Remove any macro definitions that are explicitly ignored by the module.
798  // They aren't supposed to affect how the module is built anyway.
799  const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
800  PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
801                                     RemoveIgnoredMacro(HSOpts)),
802                      PPOpts.Macros.end());
803
804
805  // Note the name of the module we're building.
806  Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
807
808  // Make sure that the failed-module structure has been allocated in
809  // the importing instance, and propagate the pointer to the newly-created
810  // instance.
811  PreprocessorOptions &ImportingPPOpts
812    = ImportingInstance.getInvocation().getPreprocessorOpts();
813  if (!ImportingPPOpts.FailedModules)
814    ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
815  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
816
817  // If there is a module map file, build the module using the module map.
818  // Set up the inputs/outputs so that we build the module from its umbrella
819  // header.
820  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
821  FrontendOpts.OutputFile = ModuleFileName.str();
822  FrontendOpts.DisableFree = false;
823  FrontendOpts.GenerateGlobalModuleIndex = false;
824  FrontendOpts.Inputs.clear();
825  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
826
827  // Get or create the module map that we'll use to build this module.
828  SmallString<128> TempModuleMapFileName;
829  if (const FileEntry *ModuleMapFile
830                                  = ModMap.getContainingModuleMapFile(Module)) {
831    // Use the module map where this module resides.
832    FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
833                                                    IK));
834  } else {
835    // Create a temporary module map file.
836    TempModuleMapFileName = Module->Name;
837    TempModuleMapFileName += "-%%%%%%%%.map";
838    int FD;
839    if (llvm::sys::fs::unique_file(TempModuleMapFileName.str(), FD,
840                                   TempModuleMapFileName,
841                                   /*makeAbsolute=*/true)
842          != llvm::errc::success) {
843      ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
844        << TempModuleMapFileName;
845      return;
846    }
847    // Print the module map to this file.
848    llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
849    Module->print(OS);
850    FrontendOpts.Inputs.push_back(
851      FrontendInputFile(TempModuleMapFileName.str().str(), IK));
852  }
853
854  // Don't free the remapped file buffers; they are owned by our caller.
855  PPOpts.RetainRemappedFileBuffers = true;
856
857  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
858  assert(ImportingInstance.getInvocation().getModuleHash() ==
859         Invocation->getModuleHash() && "Module hash mismatch!");
860
861  // Construct a compiler instance that will be used to actually create the
862  // module.
863  CompilerInstance Instance;
864  Instance.setInvocation(&*Invocation);
865
866  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
867                                   ImportingInstance.getDiagnosticClient()),
868                             /*ShouldOwnClient=*/true);
869
870  // Note that this module is part of the module build stack, so that we
871  // can detect cycles in the module graph.
872  Instance.createFileManager(); // FIXME: Adopt file manager from importer?
873  Instance.createSourceManager(Instance.getFileManager());
874  SourceManager &SourceMgr = Instance.getSourceManager();
875  SourceMgr.setModuleBuildStack(
876    ImportingInstance.getSourceManager().getModuleBuildStack());
877  SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
878    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
879
880
881  // Construct a module-generating action.
882  GenerateModuleAction CreateModuleAction;
883
884  // Execute the action to actually build the module in-place. Use a separate
885  // thread so that we get a stack large enough.
886  const unsigned ThreadStackSize = 8 << 20;
887  llvm::CrashRecoveryContext CRC;
888  CompileModuleMapData Data = { Instance, CreateModuleAction };
889  CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
890
891
892  // Delete the temporary module map file.
893  // FIXME: Even though we're executing under crash protection, it would still
894  // be nice to do this with RemoveFileOnSignal when we can. However, that
895  // doesn't make sense for all clients, so clean this up manually.
896  Instance.clearOutputFiles(/*EraseFiles=*/true);
897  if (!TempModuleMapFileName.empty())
898    llvm::sys::Path(TempModuleMapFileName).eraseFromDisk();
899
900  // We've rebuilt a module. If we're allowed to generate or update the global
901  // module index, record that fact in the importing compiler instance.
902  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
903    ImportingInstance.setBuildGlobalModuleIndex(true);
904  }
905}
906
907/// \brief Diagnose differences between the current definition of the given
908/// configuration macro and the definition provided on the command line.
909static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
910                             Module *Mod, SourceLocation ImportLoc) {
911  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
912  SourceManager &SourceMgr = PP.getSourceManager();
913
914  // If this identifier has never had a macro definition, then it could
915  // not have changed.
916  if (!Id->hadMacroDefinition())
917    return;
918
919  // If this identifier does not currently have a macro definition,
920  // check whether it had one on the command line.
921  if (!Id->hasMacroDefinition()) {
922    MacroDirective::DefInfo LatestDef =
923        PP.getMacroDirectiveHistory(Id)->getDefinition();
924    for (MacroDirective::DefInfo Def = LatestDef; Def;
925           Def = Def.getPreviousDefinition()) {
926      FileID FID = SourceMgr.getFileID(Def.getLocation());
927      if (FID.isInvalid())
928        continue;
929
930      // We only care about the predefines buffer.
931      if (FID != PP.getPredefinesFileID())
932        continue;
933
934      // This macro was defined on the command line, then #undef'd later.
935      // Complain.
936      PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
937        << true << ConfigMacro << Mod->getFullModuleName();
938      if (LatestDef.isUndefined())
939        PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
940          << true;
941      return;
942    }
943
944    // Okay: no definition in the predefines buffer.
945    return;
946  }
947
948  // This identifier has a macro definition. Check whether we had a definition
949  // on the command line.
950  MacroDirective::DefInfo LatestDef =
951      PP.getMacroDirectiveHistory(Id)->getDefinition();
952  MacroDirective::DefInfo PredefinedDef;
953  for (MacroDirective::DefInfo Def = LatestDef; Def;
954         Def = Def.getPreviousDefinition()) {
955    FileID FID = SourceMgr.getFileID(Def.getLocation());
956    if (FID.isInvalid())
957      continue;
958
959    // We only care about the predefines buffer.
960    if (FID != PP.getPredefinesFileID())
961      continue;
962
963    PredefinedDef = Def;
964    break;
965  }
966
967  // If there was no definition for this macro in the predefines buffer,
968  // complain.
969  if (!PredefinedDef ||
970      (!PredefinedDef.getLocation().isValid() &&
971       PredefinedDef.getUndefLocation().isValid())) {
972    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
973      << false << ConfigMacro << Mod->getFullModuleName();
974    PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
975      << false;
976    return;
977  }
978
979  // If the current macro definition is the same as the predefined macro
980  // definition, it's okay.
981  if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
982      LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
983                                              /*Syntactically=*/true))
984    return;
985
986  // The macro definitions differ.
987  PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
988    << false << ConfigMacro << Mod->getFullModuleName();
989  PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
990    << false;
991}
992
993/// \brief Write a new timestamp file with the given path.
994static void writeTimestampFile(StringRef TimestampFile) {
995  std::string ErrorInfo;
996  llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
997                           llvm::raw_fd_ostream::F_Binary);
998}
999
1000/// \brief Prune the module cache of modules that haven't been accessed in
1001/// a long time.
1002static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1003  struct stat StatBuf;
1004  llvm::SmallString<128> TimestampFile;
1005  TimestampFile = HSOpts.ModuleCachePath;
1006  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1007
1008  // Try to stat() the timestamp file.
1009  if (::stat(TimestampFile.c_str(), &StatBuf)) {
1010    // If the timestamp file wasn't there, create one now.
1011    if (errno == ENOENT) {
1012      writeTimestampFile(TimestampFile);
1013    }
1014    return;
1015  }
1016
1017  // Check whether the time stamp is older than our pruning interval.
1018  // If not, do nothing.
1019  time_t TimeStampModTime = StatBuf.st_mtime;
1020  time_t CurrentTime = time(0);
1021  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1022    return;
1023
1024  // Write a new timestamp file so that nobody else attempts to prune.
1025  // There is a benign race condition here, if two Clang instances happen to
1026  // notice at the same time that the timestamp is out-of-date.
1027  writeTimestampFile(TimestampFile);
1028
1029  // Walk the entire module cache, looking for unused module files and module
1030  // indices.
1031  llvm::error_code EC;
1032  SmallString<128> ModuleCachePathNative;
1033  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1034  for (llvm::sys::fs::directory_iterator
1035         Dir(ModuleCachePathNative.str(), EC), DirEnd;
1036       Dir != DirEnd && !EC; Dir.increment(EC)) {
1037    // If we don't have a directory, there's nothing to look into.
1038    bool IsDirectory;
1039    if (llvm::sys::fs::is_directory(Dir->path(), IsDirectory) || !IsDirectory)
1040      continue;
1041
1042    // Walk all of the files within this directory.
1043    bool RemovedAllFiles = true;
1044    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1045         File != FileEnd && !EC; File.increment(EC)) {
1046      // We only care about module and global module index files.
1047      if (llvm::sys::path::extension(File->path()) != ".pcm" &&
1048          llvm::sys::path::filename(File->path()) != "modules.idx") {
1049        RemovedAllFiles = false;
1050        continue;
1051      }
1052
1053      // Look at this file. If we can't stat it, there's nothing interesting
1054      // there.
1055      if (::stat(File->path().c_str(), &StatBuf)) {
1056        RemovedAllFiles = false;
1057        continue;
1058      }
1059
1060      // If the file has been used recently enough, leave it there.
1061      time_t FileAccessTime = StatBuf.st_atime;
1062      if (CurrentTime - FileAccessTime <=
1063              time_t(HSOpts.ModuleCachePruneAfter)) {
1064        RemovedAllFiles = false;
1065        continue;
1066      }
1067
1068      // Remove the file.
1069      bool Existed;
1070      if (llvm::sys::fs::remove(File->path(), Existed) || !Existed) {
1071        RemovedAllFiles = false;
1072      }
1073    }
1074
1075    // If we removed all of the files in the directory, remove the directory
1076    // itself.
1077    if (RemovedAllFiles) {
1078      bool Existed;
1079      llvm::sys::fs::remove(Dir->path(), Existed);
1080    }
1081  }
1082}
1083
1084ModuleLoadResult
1085CompilerInstance::loadModule(SourceLocation ImportLoc,
1086                             ModuleIdPath Path,
1087                             Module::NameVisibilityKind Visibility,
1088                             bool IsInclusionDirective) {
1089  // If we've already handled this import, just return the cached result.
1090  // This one-element cache is important to eliminate redundant diagnostics
1091  // when both the preprocessor and parser see the same import declaration.
1092  if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1093    // Make the named module visible.
1094    if (LastModuleImportResult)
1095      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1096                                       ImportLoc, /*Complain=*/false);
1097    return LastModuleImportResult;
1098  }
1099
1100  // Determine what file we're searching from.
1101  StringRef ModuleName = Path[0].first->getName();
1102  SourceLocation ModuleNameLoc = Path[0].second;
1103
1104  clang::Module *Module = 0;
1105
1106  // If we don't already have information on this module, load the module now.
1107  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1108    = KnownModules.find(Path[0].first);
1109  if (Known != KnownModules.end()) {
1110    // Retrieve the cached top-level module.
1111    Module = Known->second;
1112  } else if (ModuleName == getLangOpts().CurrentModule) {
1113    // This is the module we're building.
1114    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1115    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1116  } else {
1117    // Search for a module with the given name.
1118    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1119    std::string ModuleFileName;
1120    if (Module) {
1121      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1122    } else
1123      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1124
1125    // If we don't already have an ASTReader, create one now.
1126    if (!ModuleManager) {
1127      if (!hasASTContext())
1128        createASTContext();
1129
1130      // If we're not recursively building a module, check whether we
1131      // need to prune the module cache.
1132      if (getSourceManager().getModuleBuildStack().empty() &&
1133          getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1134          getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1135        pruneModuleCache(getHeaderSearchOpts());
1136      }
1137
1138      std::string Sysroot = getHeaderSearchOpts().Sysroot;
1139      const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1140      ModuleManager = new ASTReader(getPreprocessor(), *Context,
1141                                    Sysroot.empty() ? "" : Sysroot.c_str(),
1142                                    PPOpts.DisablePCHValidation,
1143                                    /*AllowASTWithCompilerErrors=*/false,
1144                                    getFrontendOpts().UseGlobalModuleIndex);
1145      if (hasASTConsumer()) {
1146        ModuleManager->setDeserializationListener(
1147          getASTConsumer().GetASTDeserializationListener());
1148        getASTContext().setASTMutationListener(
1149          getASTConsumer().GetASTMutationListener());
1150      }
1151      OwningPtr<ExternalASTSource> Source;
1152      Source.reset(ModuleManager);
1153      getASTContext().setExternalSource(Source);
1154      if (hasSema())
1155        ModuleManager->InitializeSema(getSema());
1156      if (hasASTConsumer())
1157        ModuleManager->StartTranslationUnit(&getASTConsumer());
1158    }
1159
1160    // Try to load the module file.
1161    unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1162    switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1163                                   ImportLoc, ARRFlags)) {
1164    case ASTReader::Success:
1165      break;
1166
1167    case ASTReader::OutOfDate: {
1168      // The module file is out-of-date. Remove it, then rebuild it.
1169      bool Existed;
1170      llvm::sys::fs::remove(ModuleFileName, Existed);
1171    }
1172    // Fall through to build the module again.
1173
1174    case ASTReader::Missing: {
1175      // The module file is (now) missing. Build it.
1176
1177      // If we don't have a module, we don't know how to build the module file.
1178      // Complain and return.
1179      if (!Module) {
1180        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1181          << ModuleName
1182          << SourceRange(ImportLoc, ModuleNameLoc);
1183        ModuleBuildFailed = true;
1184        return ModuleLoadResult();
1185      }
1186
1187      // Check whether there is a cycle in the module graph.
1188      ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1189      ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1190      for (; Pos != PosEnd; ++Pos) {
1191        if (Pos->first == ModuleName)
1192          break;
1193      }
1194
1195      if (Pos != PosEnd) {
1196        SmallString<256> CyclePath;
1197        for (; Pos != PosEnd; ++Pos) {
1198          CyclePath += Pos->first;
1199          CyclePath += " -> ";
1200        }
1201        CyclePath += ModuleName;
1202
1203        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1204          << ModuleName << CyclePath;
1205        return ModuleLoadResult();
1206      }
1207
1208      // Check whether we have already attempted to build this module (but
1209      // failed).
1210      if (getPreprocessorOpts().FailedModules &&
1211          getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1212        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1213          << ModuleName
1214          << SourceRange(ImportLoc, ModuleNameLoc);
1215        ModuleBuildFailed = true;
1216        return ModuleLoadResult();
1217      }
1218
1219      // Try to compile the module.
1220      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1221
1222      // Try to read the module file, now that we've compiled it.
1223      ASTReader::ASTReadResult ReadResult
1224        = ModuleManager->ReadAST(ModuleFileName,
1225                                 serialization::MK_Module, ImportLoc,
1226                                 ASTReader::ARR_Missing);
1227      if (ReadResult != ASTReader::Success) {
1228        if (ReadResult == ASTReader::Missing) {
1229          getDiagnostics().Report(ModuleNameLoc,
1230                                  Module? diag::err_module_not_built
1231                                        : diag::err_module_not_found)
1232            << ModuleName
1233            << SourceRange(ImportLoc, ModuleNameLoc);
1234        }
1235
1236        if (getPreprocessorOpts().FailedModules)
1237          getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1238        KnownModules[Path[0].first] = 0;
1239        ModuleBuildFailed = true;
1240        return ModuleLoadResult();
1241      }
1242
1243      // Okay, we've rebuilt and now loaded the module.
1244      break;
1245    }
1246
1247    case ASTReader::VersionMismatch:
1248    case ASTReader::ConfigurationMismatch:
1249    case ASTReader::HadErrors:
1250      ModuleLoader::HadFatalFailure = true;
1251      // FIXME: The ASTReader will already have complained, but can we showhorn
1252      // that diagnostic information into a more useful form?
1253      KnownModules[Path[0].first] = 0;
1254      return ModuleLoadResult();
1255
1256    case ASTReader::Failure:
1257      ModuleLoader::HadFatalFailure = true;
1258      // Already complained, but note now that we failed.
1259      KnownModules[Path[0].first] = 0;
1260      ModuleBuildFailed = true;
1261      return ModuleLoadResult();
1262    }
1263
1264    if (!Module) {
1265      // If we loaded the module directly, without finding a module map first,
1266      // we'll have loaded the module's information from the module itself.
1267      Module = PP->getHeaderSearchInfo().getModuleMap()
1268                 .findModule((Path[0].first->getName()));
1269    }
1270
1271    // Cache the result of this top-level module lookup for later.
1272    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1273  }
1274
1275  // If we never found the module, fail.
1276  if (!Module)
1277    return ModuleLoadResult();
1278
1279  // Verify that the rest of the module path actually corresponds to
1280  // a submodule.
1281  if (Path.size() > 1) {
1282    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1283      StringRef Name = Path[I].first->getName();
1284      clang::Module *Sub = Module->findSubmodule(Name);
1285
1286      if (!Sub) {
1287        // Attempt to perform typo correction to find a module name that works.
1288        SmallVector<StringRef, 2> Best;
1289        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1290
1291        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1292                                            JEnd = Module->submodule_end();
1293             J != JEnd; ++J) {
1294          unsigned ED = Name.edit_distance((*J)->Name,
1295                                           /*AllowReplacements=*/true,
1296                                           BestEditDistance);
1297          if (ED <= BestEditDistance) {
1298            if (ED < BestEditDistance) {
1299              Best.clear();
1300              BestEditDistance = ED;
1301            }
1302
1303            Best.push_back((*J)->Name);
1304          }
1305        }
1306
1307        // If there was a clear winner, user it.
1308        if (Best.size() == 1) {
1309          getDiagnostics().Report(Path[I].second,
1310                                  diag::err_no_submodule_suggest)
1311            << Path[I].first << Module->getFullModuleName() << Best[0]
1312            << SourceRange(Path[0].second, Path[I-1].second)
1313            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1314                                            Best[0]);
1315
1316          Sub = Module->findSubmodule(Best[0]);
1317        }
1318      }
1319
1320      if (!Sub) {
1321        // No submodule by this name. Complain, and don't look for further
1322        // submodules.
1323        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1324          << Path[I].first << Module->getFullModuleName()
1325          << SourceRange(Path[0].second, Path[I-1].second);
1326        break;
1327      }
1328
1329      Module = Sub;
1330    }
1331  }
1332
1333  // Make the named module visible, if it's not already part of the module
1334  // we are parsing.
1335  if (ModuleName != getLangOpts().CurrentModule) {
1336    if (!Module->IsFromModuleFile) {
1337      // We have an umbrella header or directory that doesn't actually include
1338      // all of the headers within the directory it covers. Complain about
1339      // this missing submodule and recover by forgetting that we ever saw
1340      // this submodule.
1341      // FIXME: Should we detect this at module load time? It seems fairly
1342      // expensive (and rare).
1343      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1344        << Module->getFullModuleName()
1345        << SourceRange(Path.front().second, Path.back().second);
1346
1347      return ModuleLoadResult(0, true);
1348    }
1349
1350    // Check whether this module is available.
1351    StringRef Feature;
1352    if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1353      getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1354        << Module->getFullModuleName()
1355        << Feature
1356        << SourceRange(Path.front().second, Path.back().second);
1357      LastModuleImportLoc = ImportLoc;
1358      LastModuleImportResult = ModuleLoadResult();
1359      return ModuleLoadResult();
1360    }
1361
1362    ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1363                                     /*Complain=*/true);
1364  }
1365
1366  // Check for any configuration macros that have changed.
1367  clang::Module *TopModule = Module->getTopLevelModule();
1368  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1369    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1370                     Module, ImportLoc);
1371  }
1372
1373  // If this module import was due to an inclusion directive, create an
1374  // implicit import declaration to capture it in the AST.
1375  if (IsInclusionDirective && hasASTContext()) {
1376    TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1377    ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1378                                                     ImportLoc, Module,
1379                                                     Path.back().second);
1380    TU->addDecl(ImportD);
1381    if (Consumer)
1382      Consumer->HandleImplicitImportDecl(ImportD);
1383  }
1384
1385  LastModuleImportLoc = ImportLoc;
1386  LastModuleImportResult = ModuleLoadResult(Module, false);
1387  return LastModuleImportResult;
1388}
1389
1390void CompilerInstance::makeModuleVisible(Module *Mod,
1391                                         Module::NameVisibilityKind Visibility,
1392                                         SourceLocation ImportLoc,
1393                                         bool Complain){
1394  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1395}
1396
1397