xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision dcf73d227599a43dfbf7fe9f6506d3a1eb2bd89d)
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/PathV1.h"
43 #include "llvm/Support/Program.h"
44 #include "llvm/Support/Signals.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Support/raw_ostream.h"
47 #include "llvm/Support/system_error.h"
48 #include <sys/stat.h>
49 #include <time.h>
50 
51 using namespace clang;
52 
53 CompilerInstance::CompilerInstance()
54   : Invocation(new CompilerInvocation()), ModuleManager(0),
55     BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
56 }
57 
58 CompilerInstance::~CompilerInstance() {
59   assert(OutputFiles.empty() && "Still output files in flight?");
60 }
61 
62 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
63   Invocation = Value;
64 }
65 
66 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
67   return (BuildGlobalModuleIndex ||
68           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
69            getFrontendOpts().GenerateGlobalModuleIndex)) &&
70          !ModuleBuildFailed;
71 }
72 
73 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
74   Diagnostics = Value;
75 }
76 
77 void CompilerInstance::setTarget(TargetInfo *Value) {
78   Target = Value;
79 }
80 
81 void CompilerInstance::setFileManager(FileManager *Value) {
82   FileMgr = Value;
83 }
84 
85 void CompilerInstance::setSourceManager(SourceManager *Value) {
86   SourceMgr = Value;
87 }
88 
89 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
90 
91 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
92 
93 void CompilerInstance::setSema(Sema *S) {
94   TheSema.reset(S);
95 }
96 
97 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
98   Consumer.reset(Value);
99 }
100 
101 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
102   CompletionConsumer.reset(Value);
103 }
104 
105 // Diagnostics
106 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
107                                const CodeGenOptions *CodeGenOpts,
108                                DiagnosticsEngine &Diags) {
109   std::string ErrorInfo;
110   bool OwnsStream = false;
111   raw_ostream *OS = &llvm::errs();
112   if (DiagOpts->DiagnosticLogFile != "-") {
113     // Create the output stream.
114     llvm::raw_fd_ostream *FileOS(
115       new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(),
116                                ErrorInfo, llvm::raw_fd_ostream::F_Append));
117     if (!ErrorInfo.empty()) {
118       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
119         << DiagOpts->DiagnosticLogFile << ErrorInfo;
120     } else {
121       FileOS->SetUnbuffered();
122       FileOS->SetUseAtomicWrites(true);
123       OS = FileOS;
124       OwnsStream = true;
125     }
126   }
127 
128   // Chain in the diagnostic client which will log the diagnostics.
129   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
130                                                           OwnsStream);
131   if (CodeGenOpts)
132     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
133   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
134 }
135 
136 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
137                                        DiagnosticsEngine &Diags,
138                                        StringRef OutputFile) {
139   std::string ErrorInfo;
140   OwningPtr<llvm::raw_fd_ostream> OS;
141   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
142                                     llvm::raw_fd_ostream::F_Binary));
143 
144   if (!ErrorInfo.empty()) {
145     Diags.Report(diag::warn_fe_serialized_diag_failure)
146       << OutputFile << ErrorInfo;
147     return;
148   }
149 
150   DiagnosticConsumer *SerializedConsumer =
151     clang::serialized_diags::create(OS.take(), DiagOpts);
152 
153 
154   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
155                                                 SerializedConsumer));
156 }
157 
158 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
159                                          bool ShouldOwnClient) {
160   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
161                                   ShouldOwnClient, &getCodeGenOpts());
162 }
163 
164 IntrusiveRefCntPtr<DiagnosticsEngine>
165 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
166                                     DiagnosticConsumer *Client,
167                                     bool ShouldOwnClient,
168                                     const CodeGenOptions *CodeGenOpts) {
169   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
170   IntrusiveRefCntPtr<DiagnosticsEngine>
171       Diags(new DiagnosticsEngine(DiagID, Opts));
172 
173   // Create the diagnostic client for reporting errors or for
174   // implementing -verify.
175   if (Client) {
176     Diags->setClient(Client, ShouldOwnClient);
177   } else
178     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
179 
180   // Chain in -verify checker, if requested.
181   if (Opts->VerifyDiagnostics)
182     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
183 
184   // Chain in -diagnostic-log-file dumper, if requested.
185   if (!Opts->DiagnosticLogFile.empty())
186     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
187 
188   if (!Opts->DiagnosticSerializationFile.empty())
189     SetupSerializedDiagnostics(Opts, *Diags,
190                                Opts->DiagnosticSerializationFile);
191 
192   // Configure our handling of diagnostics.
193   ProcessWarningOptions(*Diags, *Opts);
194 
195   return Diags;
196 }
197 
198 // File Manager
199 
200 void CompilerInstance::createFileManager() {
201   FileMgr = new FileManager(getFileSystemOpts());
202 }
203 
204 // Source Manager
205 
206 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
207   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
208 }
209 
210 // Preprocessor
211 
212 void CompilerInstance::createPreprocessor() {
213   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
214 
215   // Create a PTH manager if we are using some form of a token cache.
216   PTHManager *PTHMgr = 0;
217   if (!PPOpts.TokenCache.empty())
218     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
219 
220   // Create the Preprocessor.
221   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
222                                               getFileManager(),
223                                               getDiagnostics(),
224                                               getLangOpts(),
225                                               &getTarget());
226   PP = new Preprocessor(&getPreprocessorOpts(),
227                         getDiagnostics(), getLangOpts(), &getTarget(),
228                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
229                         /*OwnsHeaderSearch=*/true);
230 
231   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
232   // That argument is used as the IdentifierInfoLookup argument to
233   // IdentifierTable's ctor.
234   if (PTHMgr) {
235     PTHMgr->setPreprocessor(&*PP);
236     PP->setPTHManager(PTHMgr);
237   }
238 
239   if (PPOpts.DetailedRecord)
240     PP->createPreprocessingRecord();
241 
242   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
243 
244   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
245 
246   // Set up the module path, including the hash for the
247   // module-creation options.
248   SmallString<256> SpecificModuleCache(
249                            getHeaderSearchOpts().ModuleCachePath);
250   if (!getHeaderSearchOpts().DisableModuleHash)
251     llvm::sys::path::append(SpecificModuleCache,
252                             getInvocation().getModuleHash());
253   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
254 
255   // Handle generating dependencies, if requested.
256   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
257   if (!DepOpts.OutputFile.empty())
258     AttachDependencyFileGen(*PP, DepOpts);
259   if (!DepOpts.DOTOutputFile.empty())
260     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
261                              getHeaderSearchOpts().Sysroot);
262 
263 
264   // Handle generating header include information, if requested.
265   if (DepOpts.ShowHeaderIncludes)
266     AttachHeaderIncludeGen(*PP);
267   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
268     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
269     if (OutputPath == "-")
270       OutputPath = "";
271     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
272                            /*ShowDepth=*/false);
273   }
274 }
275 
276 // ASTContext
277 
278 void CompilerInstance::createASTContext() {
279   Preprocessor &PP = getPreprocessor();
280   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
281                            &getTarget(), PP.getIdentifierTable(),
282                            PP.getSelectorTable(), PP.getBuiltinInfo(),
283                            /*size_reserve=*/ 0);
284 }
285 
286 // ExternalASTSource
287 
288 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
289                                                   bool DisablePCHValidation,
290                                                 bool AllowPCHWithCompilerErrors,
291                                                  void *DeserializationListener){
292   OwningPtr<ExternalASTSource> Source;
293   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
294   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
295                                           DisablePCHValidation,
296                                           AllowPCHWithCompilerErrors,
297                                           getPreprocessor(), getASTContext(),
298                                           DeserializationListener,
299                                           Preamble,
300                                        getFrontendOpts().UseGlobalModuleIndex));
301   ModuleManager = static_cast<ASTReader*>(Source.get());
302   getASTContext().setExternalSource(Source);
303 }
304 
305 ExternalASTSource *
306 CompilerInstance::createPCHExternalASTSource(StringRef Path,
307                                              const std::string &Sysroot,
308                                              bool DisablePCHValidation,
309                                              bool AllowPCHWithCompilerErrors,
310                                              Preprocessor &PP,
311                                              ASTContext &Context,
312                                              void *DeserializationListener,
313                                              bool Preamble,
314                                              bool UseGlobalModuleIndex) {
315   OwningPtr<ASTReader> Reader;
316   Reader.reset(new ASTReader(PP, Context,
317                              Sysroot.empty() ? "" : Sysroot.c_str(),
318                              DisablePCHValidation,
319                              AllowPCHWithCompilerErrors,
320                              UseGlobalModuleIndex));
321 
322   Reader->setDeserializationListener(
323             static_cast<ASTDeserializationListener *>(DeserializationListener));
324   switch (Reader->ReadAST(Path,
325                           Preamble ? serialization::MK_Preamble
326                                    : serialization::MK_PCH,
327                           SourceLocation(),
328                           ASTReader::ARR_None)) {
329   case ASTReader::Success:
330     // Set the predefines buffer as suggested by the PCH reader. Typically, the
331     // predefines buffer will be empty.
332     PP.setPredefines(Reader->getSuggestedPredefines());
333     return Reader.take();
334 
335   case ASTReader::Failure:
336     // Unrecoverable failure: don't even try to process the input file.
337     break;
338 
339   case ASTReader::Missing:
340   case ASTReader::OutOfDate:
341   case ASTReader::VersionMismatch:
342   case ASTReader::ConfigurationMismatch:
343   case ASTReader::HadErrors:
344     // No suitable PCH file could be found. Return an error.
345     break;
346   }
347 
348   return 0;
349 }
350 
351 // Code Completion
352 
353 static bool EnableCodeCompletion(Preprocessor &PP,
354                                  const std::string &Filename,
355                                  unsigned Line,
356                                  unsigned Column) {
357   // Tell the source manager to chop off the given file at a specific
358   // line and column.
359   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
360   if (!Entry) {
361     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
362       << Filename;
363     return true;
364   }
365 
366   // Truncate the named file at the given line/column.
367   PP.SetCodeCompletionPoint(Entry, Line, Column);
368   return false;
369 }
370 
371 void CompilerInstance::createCodeCompletionConsumer() {
372   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
373   if (!CompletionConsumer) {
374     setCodeCompletionConsumer(
375       createCodeCompletionConsumer(getPreprocessor(),
376                                    Loc.FileName, Loc.Line, Loc.Column,
377                                    getFrontendOpts().CodeCompleteOpts,
378                                    llvm::outs()));
379     if (!CompletionConsumer)
380       return;
381   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
382                                   Loc.Line, Loc.Column)) {
383     setCodeCompletionConsumer(0);
384     return;
385   }
386 
387   if (CompletionConsumer->isOutputBinary() &&
388       llvm::sys::ChangeStdoutToBinary()) {
389     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
390     setCodeCompletionConsumer(0);
391   }
392 }
393 
394 void CompilerInstance::createFrontendTimer() {
395   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
396 }
397 
398 CodeCompleteConsumer *
399 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
400                                                const std::string &Filename,
401                                                unsigned Line,
402                                                unsigned Column,
403                                                const CodeCompleteOptions &Opts,
404                                                raw_ostream &OS) {
405   if (EnableCodeCompletion(PP, Filename, Line, Column))
406     return 0;
407 
408   // Set up the creation routine for code-completion.
409   return new PrintingCodeCompleteConsumer(Opts, OS);
410 }
411 
412 void CompilerInstance::createSema(TranslationUnitKind TUKind,
413                                   CodeCompleteConsumer *CompletionConsumer) {
414   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
415                          TUKind, CompletionConsumer));
416 }
417 
418 // Output Files
419 
420 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
421   assert(OutFile.OS && "Attempt to add empty stream to output list!");
422   OutputFiles.push_back(OutFile);
423 }
424 
425 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
426   for (std::list<OutputFile>::iterator
427          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
428     delete it->OS;
429     if (!it->TempFilename.empty()) {
430       if (EraseFiles) {
431         bool existed;
432         llvm::sys::fs::remove(it->TempFilename, existed);
433       } else {
434         SmallString<128> NewOutFile(it->Filename);
435 
436         // If '-working-directory' was passed, the output filename should be
437         // relative to that.
438         FileMgr->FixupRelativePath(NewOutFile);
439         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
440                                                         NewOutFile.str())) {
441           getDiagnostics().Report(diag::err_unable_to_rename_temp)
442             << it->TempFilename << it->Filename << ec.message();
443 
444           bool existed;
445           llvm::sys::fs::remove(it->TempFilename, existed);
446         }
447       }
448     } else if (!it->Filename.empty() && EraseFiles)
449       llvm::sys::Path(it->Filename).eraseFromDisk();
450 
451   }
452   OutputFiles.clear();
453 }
454 
455 llvm::raw_fd_ostream *
456 CompilerInstance::createDefaultOutputFile(bool Binary,
457                                           StringRef InFile,
458                                           StringRef Extension) {
459   return createOutputFile(getFrontendOpts().OutputFile, Binary,
460                           /*RemoveFileOnSignal=*/true, InFile, Extension,
461                           /*UseTemporary=*/true);
462 }
463 
464 llvm::raw_fd_ostream *
465 CompilerInstance::createOutputFile(StringRef OutputPath,
466                                    bool Binary, bool RemoveFileOnSignal,
467                                    StringRef InFile,
468                                    StringRef Extension,
469                                    bool UseTemporary,
470                                    bool CreateMissingDirectories) {
471   std::string Error, OutputPathName, TempPathName;
472   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
473                                               RemoveFileOnSignal,
474                                               InFile, Extension,
475                                               UseTemporary,
476                                               CreateMissingDirectories,
477                                               &OutputPathName,
478                                               &TempPathName);
479   if (!OS) {
480     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
481       << OutputPath << Error;
482     return 0;
483   }
484 
485   // Add the output file -- but don't try to remove "-", since this means we are
486   // using stdin.
487   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
488                 TempPathName, OS));
489 
490   return OS;
491 }
492 
493 llvm::raw_fd_ostream *
494 CompilerInstance::createOutputFile(StringRef OutputPath,
495                                    std::string &Error,
496                                    bool Binary,
497                                    bool RemoveFileOnSignal,
498                                    StringRef InFile,
499                                    StringRef Extension,
500                                    bool UseTemporary,
501                                    bool CreateMissingDirectories,
502                                    std::string *ResultPathName,
503                                    std::string *TempPathName) {
504   assert((!CreateMissingDirectories || UseTemporary) &&
505          "CreateMissingDirectories is only allowed when using temporary files");
506 
507   std::string OutFile, TempFile;
508   if (!OutputPath.empty()) {
509     OutFile = OutputPath;
510   } else if (InFile == "-") {
511     OutFile = "-";
512   } else if (!Extension.empty()) {
513     llvm::sys::Path Path(InFile);
514     Path.eraseSuffix();
515     Path.appendSuffix(Extension);
516     OutFile = Path.str();
517   } else {
518     OutFile = "-";
519   }
520 
521   OwningPtr<llvm::raw_fd_ostream> OS;
522   std::string OSFile;
523 
524   if (UseTemporary && OutFile != "-") {
525     // Only create the temporary if the parent directory exists (or create
526     // missing directories is true) and we can actually write to OutPath,
527     // otherwise we want to fail early.
528     SmallString<256> AbsPath(OutputPath);
529     llvm::sys::fs::make_absolute(AbsPath);
530     llvm::sys::Path OutPath(AbsPath);
531     bool ParentExists = false;
532     if (llvm::sys::fs::exists(llvm::sys::path::parent_path(AbsPath.str()),
533                               ParentExists))
534       ParentExists = false;
535     bool Exists;
536     if ((CreateMissingDirectories || ParentExists) &&
537         ((llvm::sys::fs::exists(AbsPath.str(), Exists) || !Exists) ||
538          (OutPath.isRegularFile() && OutPath.canWrite()))) {
539       // Create a temporary file.
540       SmallString<128> TempPath;
541       TempPath = OutFile;
542       TempPath += "-%%%%%%%%";
543       int fd;
544       if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
545                                      /*makeAbsolute=*/false, 0664)
546           == llvm::errc::success) {
547         OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
548         OSFile = TempFile = TempPath.str();
549       }
550     }
551   }
552 
553   if (!OS) {
554     OSFile = OutFile;
555     OS.reset(
556       new llvm::raw_fd_ostream(OSFile.c_str(), Error,
557                                (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
558     if (!Error.empty())
559       return 0;
560   }
561 
562   // Make sure the out stream file gets removed if we crash.
563   if (RemoveFileOnSignal)
564     llvm::sys::RemoveFileOnSignal(OSFile);
565 
566   if (ResultPathName)
567     *ResultPathName = OutFile;
568   if (TempPathName)
569     *TempPathName = TempFile;
570 
571   return OS.take();
572 }
573 
574 // Initialization Utilities
575 
576 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
577   return InitializeSourceManager(Input, getDiagnostics(),
578                                  getFileManager(), getSourceManager(),
579                                  getFrontendOpts());
580 }
581 
582 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
583                                                DiagnosticsEngine &Diags,
584                                                FileManager &FileMgr,
585                                                SourceManager &SourceMgr,
586                                                const FrontendOptions &Opts) {
587   SrcMgr::CharacteristicKind
588     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
589 
590   if (Input.isBuffer()) {
591     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
592     assert(!SourceMgr.getMainFileID().isInvalid() &&
593            "Couldn't establish MainFileID!");
594     return true;
595   }
596 
597   StringRef InputFile = Input.getFile();
598 
599   // Figure out where to get and map in the main file.
600   if (InputFile != "-") {
601     const FileEntry *File = FileMgr.getFile(InputFile);
602     if (!File) {
603       Diags.Report(diag::err_fe_error_reading) << InputFile;
604       return false;
605     }
606 
607     // The natural SourceManager infrastructure can't currently handle named
608     // pipes, but we would at least like to accept them for the main
609     // file. Detect them here, read them with the more generic MemoryBuffer
610     // function, and simply override their contents as we do for STDIN.
611     if (File->isNamedPipe()) {
612       OwningPtr<llvm::MemoryBuffer> MB;
613       if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
614         Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
615         return false;
616       }
617 
618       // Create a new virtual file that will have the correct size.
619       File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
620       SourceMgr.overrideFileContents(File, MB.take());
621     }
622 
623     SourceMgr.createMainFileID(File, Kind);
624   } else {
625     OwningPtr<llvm::MemoryBuffer> SB;
626     if (llvm::MemoryBuffer::getSTDIN(SB)) {
627       // FIXME: Give ec.message() in this diag.
628       Diags.Report(diag::err_fe_error_reading_stdin);
629       return false;
630     }
631     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
632                                                    SB->getBufferSize(), 0);
633     SourceMgr.createMainFileID(File, Kind);
634     SourceMgr.overrideFileContents(File, SB.take());
635   }
636 
637   assert(!SourceMgr.getMainFileID().isInvalid() &&
638          "Couldn't establish MainFileID!");
639   return true;
640 }
641 
642 // High-Level Operations
643 
644 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
645   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
646   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
647   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
648 
649   // FIXME: Take this as an argument, once all the APIs we used have moved to
650   // taking it as an input instead of hard-coding llvm::errs.
651   raw_ostream &OS = llvm::errs();
652 
653   // Create the target instance.
654   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
655   if (!hasTarget())
656     return false;
657 
658   // Inform the target of the language options.
659   //
660   // FIXME: We shouldn't need to do this, the target should be immutable once
661   // created. This complexity should be lifted elsewhere.
662   getTarget().setForcedLangOptions(getLangOpts());
663 
664   // rewriter project will change target built-in bool type from its default.
665   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
666     getTarget().noSignedCharForObjCBool();
667 
668   // Validate/process some options.
669   if (getHeaderSearchOpts().Verbose)
670     OS << "clang -cc1 version " CLANG_VERSION_STRING
671        << " based upon " << PACKAGE_STRING
672        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
673 
674   if (getFrontendOpts().ShowTimers)
675     createFrontendTimer();
676 
677   if (getFrontendOpts().ShowStats)
678     llvm::EnableStatistics();
679 
680   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
681     // Reset the ID tables if we are reusing the SourceManager.
682     if (hasSourceManager())
683       getSourceManager().clearIDTables();
684 
685     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
686       Act.Execute();
687       Act.EndSourceFile();
688     }
689   }
690 
691   // Notify the diagnostic client that all files were processed.
692   getDiagnostics().getClient()->finish();
693 
694   if (getDiagnosticOpts().ShowCarets) {
695     // We can have multiple diagnostics sharing one diagnostic client.
696     // Get the total number of warnings/errors from the client.
697     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
698     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
699 
700     if (NumWarnings)
701       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
702     if (NumWarnings && NumErrors)
703       OS << " and ";
704     if (NumErrors)
705       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
706     if (NumWarnings || NumErrors)
707       OS << " generated.\n";
708   }
709 
710   if (getFrontendOpts().ShowStats && hasFileManager()) {
711     getFileManager().PrintStats();
712     OS << "\n";
713   }
714 
715   return !getDiagnostics().getClient()->getNumErrors();
716 }
717 
718 /// \brief Determine the appropriate source input kind based on language
719 /// options.
720 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
721   if (LangOpts.OpenCL)
722     return IK_OpenCL;
723   if (LangOpts.CUDA)
724     return IK_CUDA;
725   if (LangOpts.ObjC1)
726     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
727   return LangOpts.CPlusPlus? IK_CXX : IK_C;
728 }
729 
730 namespace {
731   struct CompileModuleMapData {
732     CompilerInstance &Instance;
733     GenerateModuleAction &CreateModuleAction;
734   };
735 }
736 
737 /// \brief Helper function that executes the module-generating action under
738 /// a crash recovery context.
739 static void doCompileMapModule(void *UserData) {
740   CompileModuleMapData &Data
741     = *reinterpret_cast<CompileModuleMapData *>(UserData);
742   Data.Instance.ExecuteAction(Data.CreateModuleAction);
743 }
744 
745 namespace {
746   /// \brief Function object that checks with the given macro definition should
747   /// be removed, because it is one of the ignored macros.
748   class RemoveIgnoredMacro {
749     const HeaderSearchOptions &HSOpts;
750 
751   public:
752     explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
753       : HSOpts(HSOpts) { }
754 
755     bool operator()(const std::pair<std::string, bool> &def) const {
756       StringRef MacroDef = def.first;
757       return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
758     }
759   };
760 }
761 
762 /// \brief Compile a module file for the given module, using the options
763 /// provided by the importing compiler instance.
764 static void compileModule(CompilerInstance &ImportingInstance,
765                           SourceLocation ImportLoc,
766                           Module *Module,
767                           StringRef ModuleFileName) {
768   llvm::LockFileManager Locked(ModuleFileName);
769   switch (Locked) {
770   case llvm::LockFileManager::LFS_Error:
771     return;
772 
773   case llvm::LockFileManager::LFS_Owned:
774     // We're responsible for building the module ourselves. Do so below.
775     break;
776 
777   case llvm::LockFileManager::LFS_Shared:
778     // Someone else is responsible for building the module. Wait for them to
779     // finish.
780     Locked.waitForUnlock();
781     return;
782   }
783 
784   ModuleMap &ModMap
785     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
786 
787   // Construct a compiler invocation for creating this module.
788   IntrusiveRefCntPtr<CompilerInvocation> Invocation
789     (new CompilerInvocation(ImportingInstance.getInvocation()));
790 
791   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
792 
793   // For any options that aren't intended to affect how a module is built,
794   // reset them to their default values.
795   Invocation->getLangOpts()->resetNonModularOptions();
796   PPOpts.resetNonModularOptions();
797 
798   // Remove any macro definitions that are explicitly ignored by the module.
799   // They aren't supposed to affect how the module is built anyway.
800   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
801   PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
802                                      RemoveIgnoredMacro(HSOpts)),
803                       PPOpts.Macros.end());
804 
805 
806   // Note the name of the module we're building.
807   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
808 
809   // Make sure that the failed-module structure has been allocated in
810   // the importing instance, and propagate the pointer to the newly-created
811   // instance.
812   PreprocessorOptions &ImportingPPOpts
813     = ImportingInstance.getInvocation().getPreprocessorOpts();
814   if (!ImportingPPOpts.FailedModules)
815     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
816   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
817 
818   // If there is a module map file, build the module using the module map.
819   // Set up the inputs/outputs so that we build the module from its umbrella
820   // header.
821   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
822   FrontendOpts.OutputFile = ModuleFileName.str();
823   FrontendOpts.DisableFree = false;
824   FrontendOpts.GenerateGlobalModuleIndex = false;
825   FrontendOpts.Inputs.clear();
826   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
827 
828   // Get or create the module map that we'll use to build this module.
829   SmallString<128> TempModuleMapFileName;
830   if (const FileEntry *ModuleMapFile
831                                   = ModMap.getContainingModuleMapFile(Module)) {
832     // Use the module map where this module resides.
833     FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
834                                                     IK));
835   } else {
836     // Create a temporary module map file.
837     TempModuleMapFileName = Module->Name;
838     TempModuleMapFileName += "-%%%%%%%%.map";
839     int FD;
840     if (llvm::sys::fs::unique_file(TempModuleMapFileName.str(), FD,
841                                    TempModuleMapFileName,
842                                    /*makeAbsolute=*/true)
843           != llvm::errc::success) {
844       ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
845         << TempModuleMapFileName;
846       return;
847     }
848     // Print the module map to this file.
849     llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
850     Module->print(OS);
851     FrontendOpts.Inputs.push_back(
852       FrontendInputFile(TempModuleMapFileName.str().str(), IK));
853   }
854 
855   // Don't free the remapped file buffers; they are owned by our caller.
856   PPOpts.RetainRemappedFileBuffers = true;
857 
858   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
859   assert(ImportingInstance.getInvocation().getModuleHash() ==
860          Invocation->getModuleHash() && "Module hash mismatch!");
861 
862   // Construct a compiler instance that will be used to actually create the
863   // module.
864   CompilerInstance Instance;
865   Instance.setInvocation(&*Invocation);
866 
867   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
868                                    ImportingInstance.getDiagnosticClient()),
869                              /*ShouldOwnClient=*/true);
870 
871   // Note that this module is part of the module build stack, so that we
872   // can detect cycles in the module graph.
873   Instance.createFileManager(); // FIXME: Adopt file manager from importer?
874   Instance.createSourceManager(Instance.getFileManager());
875   SourceManager &SourceMgr = Instance.getSourceManager();
876   SourceMgr.setModuleBuildStack(
877     ImportingInstance.getSourceManager().getModuleBuildStack());
878   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
879     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
880 
881 
882   // Construct a module-generating action.
883   GenerateModuleAction CreateModuleAction;
884 
885   // Execute the action to actually build the module in-place. Use a separate
886   // thread so that we get a stack large enough.
887   const unsigned ThreadStackSize = 8 << 20;
888   llvm::CrashRecoveryContext CRC;
889   CompileModuleMapData Data = { Instance, CreateModuleAction };
890   CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
891 
892 
893   // Delete the temporary module map file.
894   // FIXME: Even though we're executing under crash protection, it would still
895   // be nice to do this with RemoveFileOnSignal when we can. However, that
896   // doesn't make sense for all clients, so clean this up manually.
897   Instance.clearOutputFiles(/*EraseFiles=*/true);
898   if (!TempModuleMapFileName.empty())
899     llvm::sys::Path(TempModuleMapFileName).eraseFromDisk();
900 
901   // We've rebuilt a module. If we're allowed to generate or update the global
902   // module index, record that fact in the importing compiler instance.
903   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
904     ImportingInstance.setBuildGlobalModuleIndex(true);
905   }
906 }
907 
908 /// \brief Diagnose differences between the current definition of the given
909 /// configuration macro and the definition provided on the command line.
910 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
911                              Module *Mod, SourceLocation ImportLoc) {
912   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
913   SourceManager &SourceMgr = PP.getSourceManager();
914 
915   // If this identifier has never had a macro definition, then it could
916   // not have changed.
917   if (!Id->hadMacroDefinition())
918     return;
919 
920   // If this identifier does not currently have a macro definition,
921   // check whether it had one on the command line.
922   if (!Id->hasMacroDefinition()) {
923     MacroDirective::DefInfo LatestDef =
924         PP.getMacroDirectiveHistory(Id)->getDefinition();
925     for (MacroDirective::DefInfo Def = LatestDef; Def;
926            Def = Def.getPreviousDefinition()) {
927       FileID FID = SourceMgr.getFileID(Def.getLocation());
928       if (FID.isInvalid())
929         continue;
930 
931       // We only care about the predefines buffer.
932       if (FID != PP.getPredefinesFileID())
933         continue;
934 
935       // This macro was defined on the command line, then #undef'd later.
936       // Complain.
937       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
938         << true << ConfigMacro << Mod->getFullModuleName();
939       if (LatestDef.isUndefined())
940         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
941           << true;
942       return;
943     }
944 
945     // Okay: no definition in the predefines buffer.
946     return;
947   }
948 
949   // This identifier has a macro definition. Check whether we had a definition
950   // on the command line.
951   MacroDirective::DefInfo LatestDef =
952       PP.getMacroDirectiveHistory(Id)->getDefinition();
953   MacroDirective::DefInfo PredefinedDef;
954   for (MacroDirective::DefInfo Def = LatestDef; Def;
955          Def = Def.getPreviousDefinition()) {
956     FileID FID = SourceMgr.getFileID(Def.getLocation());
957     if (FID.isInvalid())
958       continue;
959 
960     // We only care about the predefines buffer.
961     if (FID != PP.getPredefinesFileID())
962       continue;
963 
964     PredefinedDef = Def;
965     break;
966   }
967 
968   // If there was no definition for this macro in the predefines buffer,
969   // complain.
970   if (!PredefinedDef ||
971       (!PredefinedDef.getLocation().isValid() &&
972        PredefinedDef.getUndefLocation().isValid())) {
973     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
974       << false << ConfigMacro << Mod->getFullModuleName();
975     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
976       << false;
977     return;
978   }
979 
980   // If the current macro definition is the same as the predefined macro
981   // definition, it's okay.
982   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
983       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
984                                               /*Syntactically=*/true))
985     return;
986 
987   // The macro definitions differ.
988   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
989     << false << ConfigMacro << Mod->getFullModuleName();
990   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
991     << false;
992 }
993 
994 /// \brief Write a new timestamp file with the given path.
995 static void writeTimestampFile(StringRef TimestampFile) {
996   std::string ErrorInfo;
997   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
998                            llvm::raw_fd_ostream::F_Binary);
999 }
1000 
1001 /// \brief Prune the module cache of modules that haven't been accessed in
1002 /// a long time.
1003 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1004   struct stat StatBuf;
1005   llvm::SmallString<128> TimestampFile;
1006   TimestampFile = HSOpts.ModuleCachePath;
1007   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1008 
1009   // Try to stat() the timestamp file.
1010   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1011     // If the timestamp file wasn't there, create one now.
1012     if (errno == ENOENT) {
1013       writeTimestampFile(TimestampFile);
1014     }
1015     return;
1016   }
1017 
1018   // Check whether the time stamp is older than our pruning interval.
1019   // If not, do nothing.
1020   time_t TimeStampModTime = StatBuf.st_mtime;
1021   time_t CurrentTime = time(0);
1022   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1023     return;
1024 
1025   // Write a new timestamp file so that nobody else attempts to prune.
1026   // There is a benign race condition here, if two Clang instances happen to
1027   // notice at the same time that the timestamp is out-of-date.
1028   writeTimestampFile(TimestampFile);
1029 
1030   // Walk the entire module cache, looking for unused module files and module
1031   // indices.
1032   llvm::error_code EC;
1033   SmallString<128> ModuleCachePathNative;
1034   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1035   for (llvm::sys::fs::directory_iterator
1036          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1037        Dir != DirEnd && !EC; Dir.increment(EC)) {
1038     // If we don't have a directory, there's nothing to look into.
1039     bool IsDirectory;
1040     if (llvm::sys::fs::is_directory(Dir->path(), IsDirectory) || !IsDirectory)
1041       continue;
1042 
1043     // Walk all of the files within this directory.
1044     bool RemovedAllFiles = true;
1045     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1046          File != FileEnd && !EC; File.increment(EC)) {
1047       // We only care about module and global module index files.
1048       if (llvm::sys::path::extension(File->path()) != ".pcm" &&
1049           llvm::sys::path::filename(File->path()) != "modules.idx") {
1050         RemovedAllFiles = false;
1051         continue;
1052       }
1053 
1054       // Look at this file. If we can't stat it, there's nothing interesting
1055       // there.
1056       if (::stat(File->path().c_str(), &StatBuf)) {
1057         RemovedAllFiles = false;
1058         continue;
1059       }
1060 
1061       // If the file has been used recently enough, leave it there.
1062       time_t FileAccessTime = StatBuf.st_atime;
1063       if (CurrentTime - FileAccessTime <=
1064               time_t(HSOpts.ModuleCachePruneAfter)) {
1065         RemovedAllFiles = false;
1066         continue;
1067       }
1068 
1069       // Remove the file.
1070       bool Existed;
1071       if (llvm::sys::fs::remove(File->path(), Existed) || !Existed) {
1072         RemovedAllFiles = false;
1073       }
1074     }
1075 
1076     // If we removed all of the files in the directory, remove the directory
1077     // itself.
1078     if (RemovedAllFiles) {
1079       bool Existed;
1080       llvm::sys::fs::remove(Dir->path(), Existed);
1081     }
1082   }
1083 }
1084 
1085 ModuleLoadResult
1086 CompilerInstance::loadModule(SourceLocation ImportLoc,
1087                              ModuleIdPath Path,
1088                              Module::NameVisibilityKind Visibility,
1089                              bool IsInclusionDirective) {
1090   // If we've already handled this import, just return the cached result.
1091   // This one-element cache is important to eliminate redundant diagnostics
1092   // when both the preprocessor and parser see the same import declaration.
1093   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1094     // Make the named module visible.
1095     if (LastModuleImportResult)
1096       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1097                                        ImportLoc, /*Complain=*/false);
1098     return LastModuleImportResult;
1099   }
1100 
1101   // Determine what file we're searching from.
1102   StringRef ModuleName = Path[0].first->getName();
1103   SourceLocation ModuleNameLoc = Path[0].second;
1104 
1105   clang::Module *Module = 0;
1106 
1107   // If we don't already have information on this module, load the module now.
1108   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1109     = KnownModules.find(Path[0].first);
1110   if (Known != KnownModules.end()) {
1111     // Retrieve the cached top-level module.
1112     Module = Known->second;
1113   } else if (ModuleName == getLangOpts().CurrentModule) {
1114     // This is the module we're building.
1115     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1116     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1117   } else {
1118     // Search for a module with the given name.
1119     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1120     std::string ModuleFileName;
1121     if (Module) {
1122       ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1123     } else
1124       ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1125 
1126     // If we don't already have an ASTReader, create one now.
1127     if (!ModuleManager) {
1128       if (!hasASTContext())
1129         createASTContext();
1130 
1131       // If we're not recursively building a module, check whether we
1132       // need to prune the module cache.
1133       if (getSourceManager().getModuleBuildStack().empty() &&
1134           getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1135           getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1136         pruneModuleCache(getHeaderSearchOpts());
1137       }
1138 
1139       std::string Sysroot = getHeaderSearchOpts().Sysroot;
1140       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1141       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1142                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1143                                     PPOpts.DisablePCHValidation,
1144                                     /*AllowASTWithCompilerErrors=*/false,
1145                                     getFrontendOpts().UseGlobalModuleIndex);
1146       if (hasASTConsumer()) {
1147         ModuleManager->setDeserializationListener(
1148           getASTConsumer().GetASTDeserializationListener());
1149         getASTContext().setASTMutationListener(
1150           getASTConsumer().GetASTMutationListener());
1151       }
1152       OwningPtr<ExternalASTSource> Source;
1153       Source.reset(ModuleManager);
1154       getASTContext().setExternalSource(Source);
1155       if (hasSema())
1156         ModuleManager->InitializeSema(getSema());
1157       if (hasASTConsumer())
1158         ModuleManager->StartTranslationUnit(&getASTConsumer());
1159     }
1160 
1161     // Try to load the module file.
1162     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1163     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1164                                    ImportLoc, ARRFlags)) {
1165     case ASTReader::Success:
1166       break;
1167 
1168     case ASTReader::OutOfDate: {
1169       // The module file is out-of-date. Remove it, then rebuild it.
1170       bool Existed;
1171       llvm::sys::fs::remove(ModuleFileName, Existed);
1172     }
1173     // Fall through to build the module again.
1174 
1175     case ASTReader::Missing: {
1176       // The module file is (now) missing. Build it.
1177 
1178       // If we don't have a module, we don't know how to build the module file.
1179       // Complain and return.
1180       if (!Module) {
1181         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1182           << ModuleName
1183           << SourceRange(ImportLoc, ModuleNameLoc);
1184         ModuleBuildFailed = true;
1185         return ModuleLoadResult();
1186       }
1187 
1188       // Check whether there is a cycle in the module graph.
1189       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1190       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1191       for (; Pos != PosEnd; ++Pos) {
1192         if (Pos->first == ModuleName)
1193           break;
1194       }
1195 
1196       if (Pos != PosEnd) {
1197         SmallString<256> CyclePath;
1198         for (; Pos != PosEnd; ++Pos) {
1199           CyclePath += Pos->first;
1200           CyclePath += " -> ";
1201         }
1202         CyclePath += ModuleName;
1203 
1204         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1205           << ModuleName << CyclePath;
1206         return ModuleLoadResult();
1207       }
1208 
1209       // Check whether we have already attempted to build this module (but
1210       // failed).
1211       if (getPreprocessorOpts().FailedModules &&
1212           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1213         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1214           << ModuleName
1215           << SourceRange(ImportLoc, ModuleNameLoc);
1216         ModuleBuildFailed = true;
1217         return ModuleLoadResult();
1218       }
1219 
1220       // Try to compile the module.
1221       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1222 
1223       // Try to read the module file, now that we've compiled it.
1224       ASTReader::ASTReadResult ReadResult
1225         = ModuleManager->ReadAST(ModuleFileName,
1226                                  serialization::MK_Module, ImportLoc,
1227                                  ASTReader::ARR_Missing);
1228       if (ReadResult != ASTReader::Success) {
1229         if (ReadResult == ASTReader::Missing) {
1230           getDiagnostics().Report(ModuleNameLoc,
1231                                   Module? diag::err_module_not_built
1232                                         : diag::err_module_not_found)
1233             << ModuleName
1234             << SourceRange(ImportLoc, ModuleNameLoc);
1235         }
1236 
1237         if (getPreprocessorOpts().FailedModules)
1238           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1239         KnownModules[Path[0].first] = 0;
1240         ModuleBuildFailed = true;
1241         return ModuleLoadResult();
1242       }
1243 
1244       // Okay, we've rebuilt and now loaded the module.
1245       break;
1246     }
1247 
1248     case ASTReader::VersionMismatch:
1249     case ASTReader::ConfigurationMismatch:
1250     case ASTReader::HadErrors:
1251       ModuleLoader::HadFatalFailure = true;
1252       // FIXME: The ASTReader will already have complained, but can we showhorn
1253       // that diagnostic information into a more useful form?
1254       KnownModules[Path[0].first] = 0;
1255       return ModuleLoadResult();
1256 
1257     case ASTReader::Failure:
1258       ModuleLoader::HadFatalFailure = true;
1259       // Already complained, but note now that we failed.
1260       KnownModules[Path[0].first] = 0;
1261       ModuleBuildFailed = true;
1262       return ModuleLoadResult();
1263     }
1264 
1265     if (!Module) {
1266       // If we loaded the module directly, without finding a module map first,
1267       // we'll have loaded the module's information from the module itself.
1268       Module = PP->getHeaderSearchInfo().getModuleMap()
1269                  .findModule((Path[0].first->getName()));
1270     }
1271 
1272     // Cache the result of this top-level module lookup for later.
1273     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1274   }
1275 
1276   // If we never found the module, fail.
1277   if (!Module)
1278     return ModuleLoadResult();
1279 
1280   // Verify that the rest of the module path actually corresponds to
1281   // a submodule.
1282   if (Path.size() > 1) {
1283     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1284       StringRef Name = Path[I].first->getName();
1285       clang::Module *Sub = Module->findSubmodule(Name);
1286 
1287       if (!Sub) {
1288         // Attempt to perform typo correction to find a module name that works.
1289         SmallVector<StringRef, 2> Best;
1290         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1291 
1292         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1293                                             JEnd = Module->submodule_end();
1294              J != JEnd; ++J) {
1295           unsigned ED = Name.edit_distance((*J)->Name,
1296                                            /*AllowReplacements=*/true,
1297                                            BestEditDistance);
1298           if (ED <= BestEditDistance) {
1299             if (ED < BestEditDistance) {
1300               Best.clear();
1301               BestEditDistance = ED;
1302             }
1303 
1304             Best.push_back((*J)->Name);
1305           }
1306         }
1307 
1308         // If there was a clear winner, user it.
1309         if (Best.size() == 1) {
1310           getDiagnostics().Report(Path[I].second,
1311                                   diag::err_no_submodule_suggest)
1312             << Path[I].first << Module->getFullModuleName() << Best[0]
1313             << SourceRange(Path[0].second, Path[I-1].second)
1314             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1315                                             Best[0]);
1316 
1317           Sub = Module->findSubmodule(Best[0]);
1318         }
1319       }
1320 
1321       if (!Sub) {
1322         // No submodule by this name. Complain, and don't look for further
1323         // submodules.
1324         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1325           << Path[I].first << Module->getFullModuleName()
1326           << SourceRange(Path[0].second, Path[I-1].second);
1327         break;
1328       }
1329 
1330       Module = Sub;
1331     }
1332   }
1333 
1334   // Make the named module visible, if it's not already part of the module
1335   // we are parsing.
1336   if (ModuleName != getLangOpts().CurrentModule) {
1337     if (!Module->IsFromModuleFile) {
1338       // We have an umbrella header or directory that doesn't actually include
1339       // all of the headers within the directory it covers. Complain about
1340       // this missing submodule and recover by forgetting that we ever saw
1341       // this submodule.
1342       // FIXME: Should we detect this at module load time? It seems fairly
1343       // expensive (and rare).
1344       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1345         << Module->getFullModuleName()
1346         << SourceRange(Path.front().second, Path.back().second);
1347 
1348       return ModuleLoadResult(0, true);
1349     }
1350 
1351     // Check whether this module is available.
1352     StringRef Feature;
1353     if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1354       getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1355         << Module->getFullModuleName()
1356         << Feature
1357         << SourceRange(Path.front().second, Path.back().second);
1358       LastModuleImportLoc = ImportLoc;
1359       LastModuleImportResult = ModuleLoadResult();
1360       return ModuleLoadResult();
1361     }
1362 
1363     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1364                                      /*Complain=*/true);
1365   }
1366 
1367   // Check for any configuration macros that have changed.
1368   clang::Module *TopModule = Module->getTopLevelModule();
1369   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1370     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1371                      Module, ImportLoc);
1372   }
1373 
1374   // If this module import was due to an inclusion directive, create an
1375   // implicit import declaration to capture it in the AST.
1376   if (IsInclusionDirective && hasASTContext()) {
1377     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1378     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1379                                                      ImportLoc, Module,
1380                                                      Path.back().second);
1381     TU->addDecl(ImportD);
1382     if (Consumer)
1383       Consumer->HandleImplicitImportDecl(ImportD);
1384   }
1385 
1386   LastModuleImportLoc = ImportLoc;
1387   LastModuleImportResult = ModuleLoadResult(Module, false);
1388   return LastModuleImportResult;
1389 }
1390 
1391 void CompilerInstance::makeModuleVisible(Module *Mod,
1392                                          Module::NameVisibilityKind Visibility,
1393                                          SourceLocation ImportLoc,
1394                                          bool Complain){
1395   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1396 }
1397 
1398