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(), ErrorInfo,
115                                 llvm::sys::fs::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::sys::fs::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::fs::remove(it->Filename);
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    SmallString<128> Path(InFile);
513    llvm::sys::path::replace_extension(Path, Extension);
514    OutFile = Path.str();
515  } else {
516    OutFile = "-";
517  }
518
519  OwningPtr<llvm::raw_fd_ostream> OS;
520  std::string OSFile;
521
522  if (UseTemporary) {
523    if (OutFile == "-")
524      UseTemporary = false;
525    else {
526      llvm::sys::fs::file_status Status;
527      llvm::sys::fs::status(OutputPath, Status);
528      if (llvm::sys::fs::exists(Status)) {
529        // Fail early if we can't write to the final destination.
530        if (!llvm::sys::fs::can_write(OutputPath))
531          return 0;
532
533        // Don't use a temporary if the output is a special file. This handles
534        // things like '-o /dev/null'
535        if (!llvm::sys::fs::is_regular_file(Status))
536          UseTemporary = false;
537      }
538    }
539  }
540
541  if (UseTemporary) {
542    // Create a temporary file.
543    SmallString<128> TempPath;
544    TempPath = OutFile;
545    TempPath += "-%%%%%%%%";
546    int fd;
547    llvm::error_code EC =
548        llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
549
550    if (CreateMissingDirectories &&
551        EC == llvm::errc::no_such_file_or_directory) {
552      StringRef Parent = llvm::sys::path::parent_path(OutputPath);
553      EC = llvm::sys::fs::create_directories(Parent);
554      if (!EC) {
555        EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
556      }
557    }
558
559    if (!EC) {
560      OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
561      OSFile = TempFile = TempPath.str();
562    }
563    // If we failed to create the temporary, fallback to writing to the file
564    // directly. This handles the corner case where we cannot write to the
565    // directory, but can write to the file.
566  }
567
568  if (!OS) {
569    OSFile = OutFile;
570    OS.reset(new llvm::raw_fd_ostream(
571        OSFile.c_str(), Error,
572        (Binary ? llvm::sys::fs::F_Binary : llvm::sys::fs::F_None)));
573    if (!Error.empty())
574      return 0;
575  }
576
577  // Make sure the out stream file gets removed if we crash.
578  if (RemoveFileOnSignal)
579    llvm::sys::RemoveFileOnSignal(OSFile);
580
581  if (ResultPathName)
582    *ResultPathName = OutFile;
583  if (TempPathName)
584    *TempPathName = TempFile;
585
586  return OS.take();
587}
588
589// Initialization Utilities
590
591bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
592  return InitializeSourceManager(Input, getDiagnostics(),
593                                 getFileManager(), getSourceManager(),
594                                 getFrontendOpts());
595}
596
597bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
598                                               DiagnosticsEngine &Diags,
599                                               FileManager &FileMgr,
600                                               SourceManager &SourceMgr,
601                                               const FrontendOptions &Opts) {
602  SrcMgr::CharacteristicKind
603    Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
604
605  if (Input.isBuffer()) {
606    SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
607    assert(!SourceMgr.getMainFileID().isInvalid() &&
608           "Couldn't establish MainFileID!");
609    return true;
610  }
611
612  StringRef InputFile = Input.getFile();
613
614  // Figure out where to get and map in the main file.
615  if (InputFile != "-") {
616    const FileEntry *File = FileMgr.getFile(InputFile);
617    if (!File) {
618      Diags.Report(diag::err_fe_error_reading) << InputFile;
619      return false;
620    }
621
622    // The natural SourceManager infrastructure can't currently handle named
623    // pipes, but we would at least like to accept them for the main
624    // file. Detect them here, read them with the more generic MemoryBuffer
625    // function, and simply override their contents as we do for STDIN.
626    if (File->isNamedPipe()) {
627      OwningPtr<llvm::MemoryBuffer> MB;
628      if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
629        Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
630        return false;
631      }
632
633      // Create a new virtual file that will have the correct size.
634      File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
635      SourceMgr.overrideFileContents(File, MB.take());
636    }
637
638    SourceMgr.createMainFileID(File, Kind);
639  } else {
640    OwningPtr<llvm::MemoryBuffer> SB;
641    if (llvm::MemoryBuffer::getSTDIN(SB)) {
642      // FIXME: Give ec.message() in this diag.
643      Diags.Report(diag::err_fe_error_reading_stdin);
644      return false;
645    }
646    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
647                                                   SB->getBufferSize(), 0);
648    SourceMgr.createMainFileID(File, Kind);
649    SourceMgr.overrideFileContents(File, SB.take());
650  }
651
652  assert(!SourceMgr.getMainFileID().isInvalid() &&
653         "Couldn't establish MainFileID!");
654  return true;
655}
656
657// High-Level Operations
658
659bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
660  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
661  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
662  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
663
664  // FIXME: Take this as an argument, once all the APIs we used have moved to
665  // taking it as an input instead of hard-coding llvm::errs.
666  raw_ostream &OS = llvm::errs();
667
668  // Create the target instance.
669  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
670  if (!hasTarget())
671    return false;
672
673  // Inform the target of the language options.
674  //
675  // FIXME: We shouldn't need to do this, the target should be immutable once
676  // created. This complexity should be lifted elsewhere.
677  getTarget().setForcedLangOptions(getLangOpts());
678
679  // rewriter project will change target built-in bool type from its default.
680  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
681    getTarget().noSignedCharForObjCBool();
682
683  // Validate/process some options.
684  if (getHeaderSearchOpts().Verbose)
685    OS << "clang -cc1 version " CLANG_VERSION_STRING
686       << " based upon " << PACKAGE_STRING
687       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
688
689  if (getFrontendOpts().ShowTimers)
690    createFrontendTimer();
691
692  if (getFrontendOpts().ShowStats)
693    llvm::EnableStatistics();
694
695  for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
696    // Reset the ID tables if we are reusing the SourceManager.
697    if (hasSourceManager())
698      getSourceManager().clearIDTables();
699
700    if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
701      Act.Execute();
702      Act.EndSourceFile();
703    }
704  }
705
706  // Notify the diagnostic client that all files were processed.
707  getDiagnostics().getClient()->finish();
708
709  if (getDiagnosticOpts().ShowCarets) {
710    // We can have multiple diagnostics sharing one diagnostic client.
711    // Get the total number of warnings/errors from the client.
712    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
713    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
714
715    if (NumWarnings)
716      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
717    if (NumWarnings && NumErrors)
718      OS << " and ";
719    if (NumErrors)
720      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
721    if (NumWarnings || NumErrors)
722      OS << " generated.\n";
723  }
724
725  if (getFrontendOpts().ShowStats && hasFileManager()) {
726    getFileManager().PrintStats();
727    OS << "\n";
728  }
729
730  return !getDiagnostics().getClient()->getNumErrors();
731}
732
733/// \brief Determine the appropriate source input kind based on language
734/// options.
735static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
736  if (LangOpts.OpenCL)
737    return IK_OpenCL;
738  if (LangOpts.CUDA)
739    return IK_CUDA;
740  if (LangOpts.ObjC1)
741    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
742  return LangOpts.CPlusPlus? IK_CXX : IK_C;
743}
744
745namespace {
746  struct CompileModuleMapData {
747    CompilerInstance &Instance;
748    GenerateModuleAction &CreateModuleAction;
749  };
750}
751
752/// \brief Helper function that executes the module-generating action under
753/// a crash recovery context.
754static void doCompileMapModule(void *UserData) {
755  CompileModuleMapData &Data
756    = *reinterpret_cast<CompileModuleMapData *>(UserData);
757  Data.Instance.ExecuteAction(Data.CreateModuleAction);
758}
759
760namespace {
761  /// \brief Function object that checks with the given macro definition should
762  /// be removed, because it is one of the ignored macros.
763  class RemoveIgnoredMacro {
764    const HeaderSearchOptions &HSOpts;
765
766  public:
767    explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
768      : HSOpts(HSOpts) { }
769
770    bool operator()(const std::pair<std::string, bool> &def) const {
771      StringRef MacroDef = def.first;
772      return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
773    }
774  };
775}
776
777/// \brief Compile a module file for the given module, using the options
778/// provided by the importing compiler instance.
779static void compileModule(CompilerInstance &ImportingInstance,
780                          SourceLocation ImportLoc,
781                          Module *Module,
782                          StringRef ModuleFileName) {
783  // FIXME: have LockFileManager return an error_code so that we can
784  // avoid the mkdir when the directory already exists.
785  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
786  llvm::sys::fs::create_directories(Dir);
787
788  llvm::LockFileManager Locked(ModuleFileName);
789  switch (Locked) {
790  case llvm::LockFileManager::LFS_Error:
791    return;
792
793  case llvm::LockFileManager::LFS_Owned:
794    // We're responsible for building the module ourselves. Do so below.
795    break;
796
797  case llvm::LockFileManager::LFS_Shared:
798    // Someone else is responsible for building the module. Wait for them to
799    // finish.
800    Locked.waitForUnlock();
801    return;
802  }
803
804  ModuleMap &ModMap
805    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
806
807  // Construct a compiler invocation for creating this module.
808  IntrusiveRefCntPtr<CompilerInvocation> Invocation
809    (new CompilerInvocation(ImportingInstance.getInvocation()));
810
811  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
812
813  // For any options that aren't intended to affect how a module is built,
814  // reset them to their default values.
815  Invocation->getLangOpts()->resetNonModularOptions();
816  PPOpts.resetNonModularOptions();
817
818  // Remove any macro definitions that are explicitly ignored by the module.
819  // They aren't supposed to affect how the module is built anyway.
820  const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
821  PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
822                                     RemoveIgnoredMacro(HSOpts)),
823                      PPOpts.Macros.end());
824
825
826  // Note the name of the module we're building.
827  Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
828
829  // Make sure that the failed-module structure has been allocated in
830  // the importing instance, and propagate the pointer to the newly-created
831  // instance.
832  PreprocessorOptions &ImportingPPOpts
833    = ImportingInstance.getInvocation().getPreprocessorOpts();
834  if (!ImportingPPOpts.FailedModules)
835    ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
836  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
837
838  // If there is a module map file, build the module using the module map.
839  // Set up the inputs/outputs so that we build the module from its umbrella
840  // header.
841  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
842  FrontendOpts.OutputFile = ModuleFileName.str();
843  FrontendOpts.DisableFree = false;
844  FrontendOpts.GenerateGlobalModuleIndex = false;
845  FrontendOpts.Inputs.clear();
846  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
847
848  // Get or create the module map that we'll use to build this module.
849  SmallString<128> TempModuleMapFileName;
850  if (const FileEntry *ModuleMapFile
851                                  = ModMap.getContainingModuleMapFile(Module)) {
852    // Use the module map where this module resides.
853    FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
854                                                    IK));
855  } else {
856    // Create a temporary module map file.
857    int FD;
858    if (llvm::sys::fs::createTemporaryFile(Module->Name, "map", FD,
859                                           TempModuleMapFileName)) {
860      ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
861        << TempModuleMapFileName;
862      return;
863    }
864    // Print the module map to this file.
865    llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
866    Module->print(OS);
867    FrontendOpts.Inputs.push_back(
868      FrontendInputFile(TempModuleMapFileName.str().str(), IK));
869  }
870
871  // Don't free the remapped file buffers; they are owned by our caller.
872  PPOpts.RetainRemappedFileBuffers = true;
873
874  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
875  assert(ImportingInstance.getInvocation().getModuleHash() ==
876         Invocation->getModuleHash() && "Module hash mismatch!");
877
878  // Construct a compiler instance that will be used to actually create the
879  // module.
880  CompilerInstance Instance;
881  Instance.setInvocation(&*Invocation);
882
883  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
884                                   ImportingInstance.getDiagnosticClient()),
885                             /*ShouldOwnClient=*/true);
886
887  // Note that this module is part of the module build stack, so that we
888  // can detect cycles in the module graph.
889  Instance.createFileManager(); // FIXME: Adopt file manager from importer?
890  Instance.createSourceManager(Instance.getFileManager());
891  SourceManager &SourceMgr = Instance.getSourceManager();
892  SourceMgr.setModuleBuildStack(
893    ImportingInstance.getSourceManager().getModuleBuildStack());
894  SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
895    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
896
897
898  // Construct a module-generating action.
899  GenerateModuleAction CreateModuleAction(Module->IsSystem);
900
901  // Execute the action to actually build the module in-place. Use a separate
902  // thread so that we get a stack large enough.
903  const unsigned ThreadStackSize = 8 << 20;
904  llvm::CrashRecoveryContext CRC;
905  CompileModuleMapData Data = { Instance, CreateModuleAction };
906  CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
907
908
909  // Delete the temporary module map file.
910  // FIXME: Even though we're executing under crash protection, it would still
911  // be nice to do this with RemoveFileOnSignal when we can. However, that
912  // doesn't make sense for all clients, so clean this up manually.
913  Instance.clearOutputFiles(/*EraseFiles=*/true);
914  if (!TempModuleMapFileName.empty())
915    llvm::sys::fs::remove(TempModuleMapFileName.str());
916
917  // We've rebuilt a module. If we're allowed to generate or update the global
918  // module index, record that fact in the importing compiler instance.
919  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
920    ImportingInstance.setBuildGlobalModuleIndex(true);
921  }
922}
923
924/// \brief Diagnose differences between the current definition of the given
925/// configuration macro and the definition provided on the command line.
926static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
927                             Module *Mod, SourceLocation ImportLoc) {
928  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
929  SourceManager &SourceMgr = PP.getSourceManager();
930
931  // If this identifier has never had a macro definition, then it could
932  // not have changed.
933  if (!Id->hadMacroDefinition())
934    return;
935
936  // If this identifier does not currently have a macro definition,
937  // check whether it had one on the command line.
938  if (!Id->hasMacroDefinition()) {
939    MacroDirective::DefInfo LatestDef =
940        PP.getMacroDirectiveHistory(Id)->getDefinition();
941    for (MacroDirective::DefInfo Def = LatestDef; Def;
942           Def = Def.getPreviousDefinition()) {
943      FileID FID = SourceMgr.getFileID(Def.getLocation());
944      if (FID.isInvalid())
945        continue;
946
947      // We only care about the predefines buffer.
948      if (FID != PP.getPredefinesFileID())
949        continue;
950
951      // This macro was defined on the command line, then #undef'd later.
952      // Complain.
953      PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
954        << true << ConfigMacro << Mod->getFullModuleName();
955      if (LatestDef.isUndefined())
956        PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
957          << true;
958      return;
959    }
960
961    // Okay: no definition in the predefines buffer.
962    return;
963  }
964
965  // This identifier has a macro definition. Check whether we had a definition
966  // on the command line.
967  MacroDirective::DefInfo LatestDef =
968      PP.getMacroDirectiveHistory(Id)->getDefinition();
969  MacroDirective::DefInfo PredefinedDef;
970  for (MacroDirective::DefInfo Def = LatestDef; Def;
971         Def = Def.getPreviousDefinition()) {
972    FileID FID = SourceMgr.getFileID(Def.getLocation());
973    if (FID.isInvalid())
974      continue;
975
976    // We only care about the predefines buffer.
977    if (FID != PP.getPredefinesFileID())
978      continue;
979
980    PredefinedDef = Def;
981    break;
982  }
983
984  // If there was no definition for this macro in the predefines buffer,
985  // complain.
986  if (!PredefinedDef ||
987      (!PredefinedDef.getLocation().isValid() &&
988       PredefinedDef.getUndefLocation().isValid())) {
989    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
990      << false << ConfigMacro << Mod->getFullModuleName();
991    PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
992      << false;
993    return;
994  }
995
996  // If the current macro definition is the same as the predefined macro
997  // definition, it's okay.
998  if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
999      LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1000                                              /*Syntactically=*/true))
1001    return;
1002
1003  // The macro definitions differ.
1004  PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1005    << false << ConfigMacro << Mod->getFullModuleName();
1006  PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1007    << false;
1008}
1009
1010/// \brief Write a new timestamp file with the given path.
1011static void writeTimestampFile(StringRef TimestampFile) {
1012  std::string ErrorInfo;
1013  llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1014                           llvm::sys::fs::F_Binary);
1015}
1016
1017/// \brief Prune the module cache of modules that haven't been accessed in
1018/// a long time.
1019static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1020  struct stat StatBuf;
1021  llvm::SmallString<128> TimestampFile;
1022  TimestampFile = HSOpts.ModuleCachePath;
1023  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1024
1025  // Try to stat() the timestamp file.
1026  if (::stat(TimestampFile.c_str(), &StatBuf)) {
1027    // If the timestamp file wasn't there, create one now.
1028    if (errno == ENOENT) {
1029      writeTimestampFile(TimestampFile);
1030    }
1031    return;
1032  }
1033
1034  // Check whether the time stamp is older than our pruning interval.
1035  // If not, do nothing.
1036  time_t TimeStampModTime = StatBuf.st_mtime;
1037  time_t CurrentTime = time(0);
1038  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1039    return;
1040
1041  // Write a new timestamp file so that nobody else attempts to prune.
1042  // There is a benign race condition here, if two Clang instances happen to
1043  // notice at the same time that the timestamp is out-of-date.
1044  writeTimestampFile(TimestampFile);
1045
1046  // Walk the entire module cache, looking for unused module files and module
1047  // indices.
1048  llvm::error_code EC;
1049  SmallString<128> ModuleCachePathNative;
1050  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1051  for (llvm::sys::fs::directory_iterator
1052         Dir(ModuleCachePathNative.str(), EC), DirEnd;
1053       Dir != DirEnd && !EC; Dir.increment(EC)) {
1054    // If we don't have a directory, there's nothing to look into.
1055    if (!llvm::sys::fs::is_directory(Dir->path()))
1056      continue;
1057
1058    // Walk all of the files within this directory.
1059    bool RemovedAllFiles = true;
1060    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1061         File != FileEnd && !EC; File.increment(EC)) {
1062      // We only care about module and global module index files.
1063      if (llvm::sys::path::extension(File->path()) != ".pcm" &&
1064          llvm::sys::path::filename(File->path()) != "modules.idx") {
1065        RemovedAllFiles = false;
1066        continue;
1067      }
1068
1069      // Look at this file. If we can't stat it, there's nothing interesting
1070      // there.
1071      if (::stat(File->path().c_str(), &StatBuf)) {
1072        RemovedAllFiles = false;
1073        continue;
1074      }
1075
1076      // If the file has been used recently enough, leave it there.
1077      time_t FileAccessTime = StatBuf.st_atime;
1078      if (CurrentTime - FileAccessTime <=
1079              time_t(HSOpts.ModuleCachePruneAfter)) {
1080        RemovedAllFiles = false;
1081        continue;
1082      }
1083
1084      // Remove the file.
1085      bool Existed;
1086      if (llvm::sys::fs::remove(File->path(), Existed) || !Existed) {
1087        RemovedAllFiles = false;
1088      }
1089    }
1090
1091    // If we removed all of the files in the directory, remove the directory
1092    // itself.
1093    if (RemovedAllFiles) {
1094      bool Existed;
1095      llvm::sys::fs::remove(Dir->path(), Existed);
1096    }
1097  }
1098}
1099
1100ModuleLoadResult
1101CompilerInstance::loadModule(SourceLocation ImportLoc,
1102                             ModuleIdPath Path,
1103                             Module::NameVisibilityKind Visibility,
1104                             bool IsInclusionDirective) {
1105  // If we've already handled this import, just return the cached result.
1106  // This one-element cache is important to eliminate redundant diagnostics
1107  // when both the preprocessor and parser see the same import declaration.
1108  if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1109    // Make the named module visible.
1110    if (LastModuleImportResult)
1111      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1112                                       ImportLoc, /*Complain=*/false);
1113    return LastModuleImportResult;
1114  }
1115
1116  // Determine what file we're searching from.
1117  StringRef ModuleName = Path[0].first->getName();
1118  SourceLocation ModuleNameLoc = Path[0].second;
1119
1120  clang::Module *Module = 0;
1121
1122  // If we don't already have information on this module, load the module now.
1123  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1124    = KnownModules.find(Path[0].first);
1125  if (Known != KnownModules.end()) {
1126    // Retrieve the cached top-level module.
1127    Module = Known->second;
1128  } else if (ModuleName == getLangOpts().CurrentModule) {
1129    // This is the module we're building.
1130    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1131    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1132  } else {
1133    // Search for a module with the given name.
1134    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1135    std::string ModuleFileName;
1136    if (Module) {
1137      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1138    } else
1139      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1140
1141    // If we don't already have an ASTReader, create one now.
1142    if (!ModuleManager) {
1143      if (!hasASTContext())
1144        createASTContext();
1145
1146      // If we're not recursively building a module, check whether we
1147      // need to prune the module cache.
1148      if (getSourceManager().getModuleBuildStack().empty() &&
1149          getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1150          getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1151        pruneModuleCache(getHeaderSearchOpts());
1152      }
1153
1154      std::string Sysroot = getHeaderSearchOpts().Sysroot;
1155      const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1156      ModuleManager = new ASTReader(getPreprocessor(), *Context,
1157                                    Sysroot.empty() ? "" : Sysroot.c_str(),
1158                                    PPOpts.DisablePCHValidation,
1159                                    /*AllowASTWithCompilerErrors=*/false,
1160                                    getFrontendOpts().UseGlobalModuleIndex);
1161      if (hasASTConsumer()) {
1162        ModuleManager->setDeserializationListener(
1163          getASTConsumer().GetASTDeserializationListener());
1164        getASTContext().setASTMutationListener(
1165          getASTConsumer().GetASTMutationListener());
1166      }
1167      OwningPtr<ExternalASTSource> Source;
1168      Source.reset(ModuleManager);
1169      getASTContext().setExternalSource(Source);
1170      if (hasSema())
1171        ModuleManager->InitializeSema(getSema());
1172      if (hasASTConsumer())
1173        ModuleManager->StartTranslationUnit(&getASTConsumer());
1174    }
1175
1176    // Try to load the module file.
1177    unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1178    switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1179                                   ImportLoc, ARRFlags)) {
1180    case ASTReader::Success:
1181      break;
1182
1183    case ASTReader::OutOfDate: {
1184      // The module file is out-of-date. Remove it, then rebuild it.
1185      bool Existed;
1186      llvm::sys::fs::remove(ModuleFileName, Existed);
1187    }
1188    // Fall through to build the module again.
1189
1190    case ASTReader::Missing: {
1191      // The module file is (now) missing. Build it.
1192
1193      // If we don't have a module, we don't know how to build the module file.
1194      // Complain and return.
1195      if (!Module) {
1196        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1197          << ModuleName
1198          << SourceRange(ImportLoc, ModuleNameLoc);
1199        ModuleBuildFailed = true;
1200        return ModuleLoadResult();
1201      }
1202
1203      // Check whether there is a cycle in the module graph.
1204      ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1205      ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1206      for (; Pos != PosEnd; ++Pos) {
1207        if (Pos->first == ModuleName)
1208          break;
1209      }
1210
1211      if (Pos != PosEnd) {
1212        SmallString<256> CyclePath;
1213        for (; Pos != PosEnd; ++Pos) {
1214          CyclePath += Pos->first;
1215          CyclePath += " -> ";
1216        }
1217        CyclePath += ModuleName;
1218
1219        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1220          << ModuleName << CyclePath;
1221        return ModuleLoadResult();
1222      }
1223
1224      // Check whether we have already attempted to build this module (but
1225      // failed).
1226      if (getPreprocessorOpts().FailedModules &&
1227          getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1228        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1229          << ModuleName
1230          << SourceRange(ImportLoc, ModuleNameLoc);
1231        ModuleBuildFailed = true;
1232        return ModuleLoadResult();
1233      }
1234
1235      // Try to compile the module.
1236      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1237
1238      // Try to read the module file, now that we've compiled it.
1239      ASTReader::ASTReadResult ReadResult
1240        = ModuleManager->ReadAST(ModuleFileName,
1241                                 serialization::MK_Module, ImportLoc,
1242                                 ASTReader::ARR_Missing);
1243      if (ReadResult != ASTReader::Success) {
1244        if (ReadResult == ASTReader::Missing) {
1245          getDiagnostics().Report(ModuleNameLoc,
1246                                  Module? diag::err_module_not_built
1247                                        : diag::err_module_not_found)
1248            << ModuleName
1249            << SourceRange(ImportLoc, ModuleNameLoc);
1250        }
1251
1252        if (getPreprocessorOpts().FailedModules)
1253          getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1254        KnownModules[Path[0].first] = 0;
1255        ModuleBuildFailed = true;
1256        return ModuleLoadResult();
1257      }
1258
1259      // Okay, we've rebuilt and now loaded the module.
1260      break;
1261    }
1262
1263    case ASTReader::VersionMismatch:
1264    case ASTReader::ConfigurationMismatch:
1265    case ASTReader::HadErrors:
1266      ModuleLoader::HadFatalFailure = true;
1267      // FIXME: The ASTReader will already have complained, but can we showhorn
1268      // that diagnostic information into a more useful form?
1269      KnownModules[Path[0].first] = 0;
1270      return ModuleLoadResult();
1271
1272    case ASTReader::Failure:
1273      ModuleLoader::HadFatalFailure = true;
1274      // Already complained, but note now that we failed.
1275      KnownModules[Path[0].first] = 0;
1276      ModuleBuildFailed = true;
1277      return ModuleLoadResult();
1278    }
1279
1280    if (!Module) {
1281      // If we loaded the module directly, without finding a module map first,
1282      // we'll have loaded the module's information from the module itself.
1283      Module = PP->getHeaderSearchInfo().getModuleMap()
1284                 .findModule((Path[0].first->getName()));
1285    }
1286
1287    // Cache the result of this top-level module lookup for later.
1288    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1289  }
1290
1291  // If we never found the module, fail.
1292  if (!Module)
1293    return ModuleLoadResult();
1294
1295  // Verify that the rest of the module path actually corresponds to
1296  // a submodule.
1297  if (Path.size() > 1) {
1298    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1299      StringRef Name = Path[I].first->getName();
1300      clang::Module *Sub = Module->findSubmodule(Name);
1301
1302      if (!Sub) {
1303        // Attempt to perform typo correction to find a module name that works.
1304        SmallVector<StringRef, 2> Best;
1305        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1306
1307        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1308                                            JEnd = Module->submodule_end();
1309             J != JEnd; ++J) {
1310          unsigned ED = Name.edit_distance((*J)->Name,
1311                                           /*AllowReplacements=*/true,
1312                                           BestEditDistance);
1313          if (ED <= BestEditDistance) {
1314            if (ED < BestEditDistance) {
1315              Best.clear();
1316              BestEditDistance = ED;
1317            }
1318
1319            Best.push_back((*J)->Name);
1320          }
1321        }
1322
1323        // If there was a clear winner, user it.
1324        if (Best.size() == 1) {
1325          getDiagnostics().Report(Path[I].second,
1326                                  diag::err_no_submodule_suggest)
1327            << Path[I].first << Module->getFullModuleName() << Best[0]
1328            << SourceRange(Path[0].second, Path[I-1].second)
1329            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1330                                            Best[0]);
1331
1332          Sub = Module->findSubmodule(Best[0]);
1333        }
1334      }
1335
1336      if (!Sub) {
1337        // No submodule by this name. Complain, and don't look for further
1338        // submodules.
1339        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1340          << Path[I].first << Module->getFullModuleName()
1341          << SourceRange(Path[0].second, Path[I-1].second);
1342        break;
1343      }
1344
1345      Module = Sub;
1346    }
1347  }
1348
1349  // Make the named module visible, if it's not already part of the module
1350  // we are parsing.
1351  if (ModuleName != getLangOpts().CurrentModule) {
1352    if (!Module->IsFromModuleFile) {
1353      // We have an umbrella header or directory that doesn't actually include
1354      // all of the headers within the directory it covers. Complain about
1355      // this missing submodule and recover by forgetting that we ever saw
1356      // this submodule.
1357      // FIXME: Should we detect this at module load time? It seems fairly
1358      // expensive (and rare).
1359      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1360        << Module->getFullModuleName()
1361        << SourceRange(Path.front().second, Path.back().second);
1362
1363      return ModuleLoadResult(0, true);
1364    }
1365
1366    // Check whether this module is available.
1367    StringRef Feature;
1368    if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1369      getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1370        << Module->getFullModuleName()
1371        << Feature
1372        << SourceRange(Path.front().second, Path.back().second);
1373      LastModuleImportLoc = ImportLoc;
1374      LastModuleImportResult = ModuleLoadResult();
1375      return ModuleLoadResult();
1376    }
1377
1378    ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1379                                     /*Complain=*/true);
1380  }
1381
1382  // Check for any configuration macros that have changed.
1383  clang::Module *TopModule = Module->getTopLevelModule();
1384  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1385    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1386                     Module, ImportLoc);
1387  }
1388
1389  // If this module import was due to an inclusion directive, create an
1390  // implicit import declaration to capture it in the AST.
1391  if (IsInclusionDirective && hasASTContext()) {
1392    TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1393    ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1394                                                     ImportLoc, Module,
1395                                                     Path.back().second);
1396    TU->addDecl(ImportD);
1397    if (Consumer)
1398      Consumer->HandleImplicitImportDecl(ImportD);
1399  }
1400
1401  LastModuleImportLoc = ImportLoc;
1402  LastModuleImportResult = ModuleLoadResult(Module, false);
1403  return LastModuleImportResult;
1404}
1405
1406void CompilerInstance::makeModuleVisible(Module *Mod,
1407                                         Module::NameVisibilityKind Visibility,
1408                                         SourceLocation ImportLoc,
1409                                         bool Complain){
1410  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1411}
1412
1413