xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision e1974dcd92b0f27e4a8ba54887640b2a93993b40)
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 
50 using namespace clang;
51 
52 CompilerInstance::CompilerInstance()
53   : Invocation(new CompilerInvocation()), ModuleManager(0),
54     BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
55 }
56 
57 CompilerInstance::~CompilerInstance() {
58   assert(OutputFiles.empty() && "Still output files in flight?");
59 }
60 
61 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
62   Invocation = Value;
63 }
64 
65 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
66   return (BuildGlobalModuleIndex ||
67           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
68            getFrontendOpts().GenerateGlobalModuleIndex)) &&
69          !ModuleBuildFailed;
70 }
71 
72 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
73   Diagnostics = Value;
74 }
75 
76 void CompilerInstance::setTarget(TargetInfo *Value) {
77   Target = Value;
78 }
79 
80 void CompilerInstance::setFileManager(FileManager *Value) {
81   FileMgr = Value;
82   if (Value)
83     VirtualFileSystem = Value->getVirtualFileSystem();
84   else
85     VirtualFileSystem.reset();
86 }
87 
88 void CompilerInstance::setSourceManager(SourceManager *Value) {
89   SourceMgr = Value;
90 }
91 
92 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
93 
94 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
95 
96 void CompilerInstance::setSema(Sema *S) {
97   TheSema.reset(S);
98 }
99 
100 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
101   Consumer.reset(Value);
102 }
103 
104 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
105   CompletionConsumer.reset(Value);
106 }
107 
108 IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
109   return ModuleManager;
110 }
111 void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
112   ModuleManager = Reader;
113 }
114 
115 // Diagnostics
116 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
117                                const CodeGenOptions *CodeGenOpts,
118                                DiagnosticsEngine &Diags) {
119   std::string ErrorInfo;
120   bool OwnsStream = false;
121   raw_ostream *OS = &llvm::errs();
122   if (DiagOpts->DiagnosticLogFile != "-") {
123     // Create the output stream.
124     llvm::raw_fd_ostream *FileOS(new llvm::raw_fd_ostream(
125         DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
126         llvm::sys::fs::F_Append | llvm::sys::fs::F_Text));
127     if (!ErrorInfo.empty()) {
128       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
129         << DiagOpts->DiagnosticLogFile << ErrorInfo;
130     } else {
131       FileOS->SetUnbuffered();
132       FileOS->SetUseAtomicWrites(true);
133       OS = FileOS;
134       OwnsStream = true;
135     }
136   }
137 
138   // Chain in the diagnostic client which will log the diagnostics.
139   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
140                                                           OwnsStream);
141   if (CodeGenOpts)
142     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
143   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
144 }
145 
146 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
147                                        DiagnosticsEngine &Diags,
148                                        StringRef OutputFile) {
149   std::string ErrorInfo;
150   OwningPtr<llvm::raw_fd_ostream> OS;
151   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
152                                     llvm::sys::fs::F_None));
153 
154   if (!ErrorInfo.empty()) {
155     Diags.Report(diag::warn_fe_serialized_diag_failure)
156       << OutputFile << ErrorInfo;
157     return;
158   }
159 
160   DiagnosticConsumer *SerializedConsumer =
161     clang::serialized_diags::create(OS.take(), DiagOpts);
162 
163 
164   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
165                                                 SerializedConsumer));
166 }
167 
168 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
169                                          bool ShouldOwnClient) {
170   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
171                                   ShouldOwnClient, &getCodeGenOpts());
172 }
173 
174 IntrusiveRefCntPtr<DiagnosticsEngine>
175 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
176                                     DiagnosticConsumer *Client,
177                                     bool ShouldOwnClient,
178                                     const CodeGenOptions *CodeGenOpts) {
179   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
180   IntrusiveRefCntPtr<DiagnosticsEngine>
181       Diags(new DiagnosticsEngine(DiagID, Opts));
182 
183   // Create the diagnostic client for reporting errors or for
184   // implementing -verify.
185   if (Client) {
186     Diags->setClient(Client, ShouldOwnClient);
187   } else
188     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
189 
190   // Chain in -verify checker, if requested.
191   if (Opts->VerifyDiagnostics)
192     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
193 
194   // Chain in -diagnostic-log-file dumper, if requested.
195   if (!Opts->DiagnosticLogFile.empty())
196     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
197 
198   if (!Opts->DiagnosticSerializationFile.empty())
199     SetupSerializedDiagnostics(Opts, *Diags,
200                                Opts->DiagnosticSerializationFile);
201 
202   // Configure our handling of diagnostics.
203   ProcessWarningOptions(*Diags, *Opts);
204 
205   return Diags;
206 }
207 
208 // File Manager
209 
210 void CompilerInstance::createFileManager() {
211   if (!hasVirtualFileSystem()) {
212     // TODO: choose the virtual file system based on the CompilerInvocation.
213     setVirtualFileSystem(vfs::getRealFileSystem());
214   }
215   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
216 }
217 
218 // Source Manager
219 
220 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
221   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
222 }
223 
224 // Preprocessor
225 
226 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
227   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
228 
229   // Create a PTH manager if we are using some form of a token cache.
230   PTHManager *PTHMgr = 0;
231   if (!PPOpts.TokenCache.empty())
232     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
233 
234   // Create the Preprocessor.
235   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
236                                               getSourceManager(),
237                                               getDiagnostics(),
238                                               getLangOpts(),
239                                               &getTarget());
240   PP = new Preprocessor(&getPreprocessorOpts(),
241                         getDiagnostics(), getLangOpts(), &getTarget(),
242                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
243                         /*OwnsHeaderSearch=*/true,
244                         /*DelayInitialization=*/false,
245                         /*IncrProcessing=*/false,
246                         TUKind);
247 
248   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
249   // That argument is used as the IdentifierInfoLookup argument to
250   // IdentifierTable's ctor.
251   if (PTHMgr) {
252     PTHMgr->setPreprocessor(&*PP);
253     PP->setPTHManager(PTHMgr);
254   }
255 
256   if (PPOpts.DetailedRecord)
257     PP->createPreprocessingRecord();
258 
259   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
260 
261   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
262 
263   // Set up the module path, including the hash for the
264   // module-creation options.
265   SmallString<256> SpecificModuleCache(
266                            getHeaderSearchOpts().ModuleCachePath);
267   if (!getHeaderSearchOpts().DisableModuleHash)
268     llvm::sys::path::append(SpecificModuleCache,
269                             getInvocation().getModuleHash());
270   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
271 
272   // Handle generating dependencies, if requested.
273   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
274   if (!DepOpts.OutputFile.empty())
275     TheDependencyFileGenerator.reset(
276         DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
277   if (!DepOpts.DOTOutputFile.empty())
278     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
279                              getHeaderSearchOpts().Sysroot);
280 
281 
282   // Handle generating header include information, if requested.
283   if (DepOpts.ShowHeaderIncludes)
284     AttachHeaderIncludeGen(*PP);
285   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
286     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
287     if (OutputPath == "-")
288       OutputPath = "";
289     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
290                            /*ShowDepth=*/false);
291   }
292 
293   if (DepOpts.PrintShowIncludes) {
294     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
295                            /*ShowDepth=*/true, /*MSStyle=*/true);
296   }
297 }
298 
299 // ASTContext
300 
301 void CompilerInstance::createASTContext() {
302   Preprocessor &PP = getPreprocessor();
303   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
304                            &getTarget(), PP.getIdentifierTable(),
305                            PP.getSelectorTable(), PP.getBuiltinInfo(),
306                            /*size_reserve=*/ 0);
307 }
308 
309 // ExternalASTSource
310 
311 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
312                                                   bool DisablePCHValidation,
313                                                 bool AllowPCHWithCompilerErrors,
314                                                  void *DeserializationListener){
315   IntrusiveRefCntPtr<ExternalASTSource> Source;
316   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
317   Source = createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
318                                           DisablePCHValidation,
319                                           AllowPCHWithCompilerErrors,
320                                           getPreprocessor(), getASTContext(),
321                                           DeserializationListener,
322                                           Preamble,
323                                        getFrontendOpts().UseGlobalModuleIndex);
324   ModuleManager = static_cast<ASTReader*>(Source.getPtr());
325   getASTContext().setExternalSource(Source);
326 }
327 
328 ExternalASTSource *
329 CompilerInstance::createPCHExternalASTSource(StringRef Path,
330                                              const std::string &Sysroot,
331                                              bool DisablePCHValidation,
332                                              bool AllowPCHWithCompilerErrors,
333                                              Preprocessor &PP,
334                                              ASTContext &Context,
335                                              void *DeserializationListener,
336                                              bool Preamble,
337                                              bool UseGlobalModuleIndex) {
338   OwningPtr<ASTReader> Reader;
339   Reader.reset(new ASTReader(PP, Context,
340                              Sysroot.empty() ? "" : Sysroot.c_str(),
341                              DisablePCHValidation,
342                              AllowPCHWithCompilerErrors,
343                              /*AllowConfigurationMismatch*/false,
344                              /*ValidateSystemInputs*/false,
345                              UseGlobalModuleIndex));
346 
347   Reader->setDeserializationListener(
348             static_cast<ASTDeserializationListener *>(DeserializationListener));
349   switch (Reader->ReadAST(Path,
350                           Preamble ? serialization::MK_Preamble
351                                    : serialization::MK_PCH,
352                           SourceLocation(),
353                           ASTReader::ARR_None)) {
354   case ASTReader::Success:
355     // Set the predefines buffer as suggested by the PCH reader. Typically, the
356     // predefines buffer will be empty.
357     PP.setPredefines(Reader->getSuggestedPredefines());
358     return Reader.take();
359 
360   case ASTReader::Failure:
361     // Unrecoverable failure: don't even try to process the input file.
362     break;
363 
364   case ASTReader::Missing:
365   case ASTReader::OutOfDate:
366   case ASTReader::VersionMismatch:
367   case ASTReader::ConfigurationMismatch:
368   case ASTReader::HadErrors:
369     // No suitable PCH file could be found. Return an error.
370     break;
371   }
372 
373   return 0;
374 }
375 
376 // Code Completion
377 
378 static bool EnableCodeCompletion(Preprocessor &PP,
379                                  const std::string &Filename,
380                                  unsigned Line,
381                                  unsigned Column) {
382   // Tell the source manager to chop off the given file at a specific
383   // line and column.
384   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
385   if (!Entry) {
386     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
387       << Filename;
388     return true;
389   }
390 
391   // Truncate the named file at the given line/column.
392   PP.SetCodeCompletionPoint(Entry, Line, Column);
393   return false;
394 }
395 
396 void CompilerInstance::createCodeCompletionConsumer() {
397   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
398   if (!CompletionConsumer) {
399     setCodeCompletionConsumer(
400       createCodeCompletionConsumer(getPreprocessor(),
401                                    Loc.FileName, Loc.Line, Loc.Column,
402                                    getFrontendOpts().CodeCompleteOpts,
403                                    llvm::outs()));
404     if (!CompletionConsumer)
405       return;
406   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
407                                   Loc.Line, Loc.Column)) {
408     setCodeCompletionConsumer(0);
409     return;
410   }
411 
412   if (CompletionConsumer->isOutputBinary() &&
413       llvm::sys::ChangeStdoutToBinary()) {
414     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
415     setCodeCompletionConsumer(0);
416   }
417 }
418 
419 void CompilerInstance::createFrontendTimer() {
420   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
421 }
422 
423 CodeCompleteConsumer *
424 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
425                                                const std::string &Filename,
426                                                unsigned Line,
427                                                unsigned Column,
428                                                const CodeCompleteOptions &Opts,
429                                                raw_ostream &OS) {
430   if (EnableCodeCompletion(PP, Filename, Line, Column))
431     return 0;
432 
433   // Set up the creation routine for code-completion.
434   return new PrintingCodeCompleteConsumer(Opts, OS);
435 }
436 
437 void CompilerInstance::createSema(TranslationUnitKind TUKind,
438                                   CodeCompleteConsumer *CompletionConsumer) {
439   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
440                          TUKind, CompletionConsumer));
441 }
442 
443 // Output Files
444 
445 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
446   assert(OutFile.OS && "Attempt to add empty stream to output list!");
447   OutputFiles.push_back(OutFile);
448 }
449 
450 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
451   for (std::list<OutputFile>::iterator
452          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
453     delete it->OS;
454     if (!it->TempFilename.empty()) {
455       if (EraseFiles) {
456         llvm::sys::fs::remove(it->TempFilename);
457       } else {
458         SmallString<128> NewOutFile(it->Filename);
459 
460         // If '-working-directory' was passed, the output filename should be
461         // relative to that.
462         FileMgr->FixupRelativePath(NewOutFile);
463         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
464                                                         NewOutFile.str())) {
465           getDiagnostics().Report(diag::err_unable_to_rename_temp)
466             << it->TempFilename << it->Filename << ec.message();
467 
468           llvm::sys::fs::remove(it->TempFilename);
469         }
470       }
471     } else if (!it->Filename.empty() && EraseFiles)
472       llvm::sys::fs::remove(it->Filename);
473 
474   }
475   OutputFiles.clear();
476 }
477 
478 llvm::raw_fd_ostream *
479 CompilerInstance::createDefaultOutputFile(bool Binary,
480                                           StringRef InFile,
481                                           StringRef Extension) {
482   return createOutputFile(getFrontendOpts().OutputFile, Binary,
483                           /*RemoveFileOnSignal=*/true, InFile, Extension,
484                           /*UseTemporary=*/true);
485 }
486 
487 llvm::raw_fd_ostream *
488 CompilerInstance::createOutputFile(StringRef OutputPath,
489                                    bool Binary, bool RemoveFileOnSignal,
490                                    StringRef InFile,
491                                    StringRef Extension,
492                                    bool UseTemporary,
493                                    bool CreateMissingDirectories) {
494   std::string Error, OutputPathName, TempPathName;
495   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
496                                               RemoveFileOnSignal,
497                                               InFile, Extension,
498                                               UseTemporary,
499                                               CreateMissingDirectories,
500                                               &OutputPathName,
501                                               &TempPathName);
502   if (!OS) {
503     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
504       << OutputPath << Error;
505     return 0;
506   }
507 
508   // Add the output file -- but don't try to remove "-", since this means we are
509   // using stdin.
510   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
511                 TempPathName, OS));
512 
513   return OS;
514 }
515 
516 llvm::raw_fd_ostream *
517 CompilerInstance::createOutputFile(StringRef OutputPath,
518                                    std::string &Error,
519                                    bool Binary,
520                                    bool RemoveFileOnSignal,
521                                    StringRef InFile,
522                                    StringRef Extension,
523                                    bool UseTemporary,
524                                    bool CreateMissingDirectories,
525                                    std::string *ResultPathName,
526                                    std::string *TempPathName) {
527   assert((!CreateMissingDirectories || UseTemporary) &&
528          "CreateMissingDirectories is only allowed when using temporary files");
529 
530   std::string OutFile, TempFile;
531   if (!OutputPath.empty()) {
532     OutFile = OutputPath;
533   } else if (InFile == "-") {
534     OutFile = "-";
535   } else if (!Extension.empty()) {
536     SmallString<128> Path(InFile);
537     llvm::sys::path::replace_extension(Path, Extension);
538     OutFile = Path.str();
539   } else {
540     OutFile = "-";
541   }
542 
543   OwningPtr<llvm::raw_fd_ostream> OS;
544   std::string OSFile;
545 
546   if (UseTemporary) {
547     if (OutFile == "-")
548       UseTemporary = false;
549     else {
550       llvm::sys::fs::file_status Status;
551       llvm::sys::fs::status(OutputPath, Status);
552       if (llvm::sys::fs::exists(Status)) {
553         // Fail early if we can't write to the final destination.
554         if (!llvm::sys::fs::can_write(OutputPath))
555           return 0;
556 
557         // Don't use a temporary if the output is a special file. This handles
558         // things like '-o /dev/null'
559         if (!llvm::sys::fs::is_regular_file(Status))
560           UseTemporary = false;
561       }
562     }
563   }
564 
565   if (UseTemporary) {
566     // Create a temporary file.
567     SmallString<128> TempPath;
568     TempPath = OutFile;
569     TempPath += "-%%%%%%%%";
570     int fd;
571     llvm::error_code EC =
572         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
573 
574     if (CreateMissingDirectories &&
575         EC == llvm::errc::no_such_file_or_directory) {
576       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
577       EC = llvm::sys::fs::create_directories(Parent);
578       if (!EC) {
579         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
580       }
581     }
582 
583     if (!EC) {
584       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
585       OSFile = TempFile = TempPath.str();
586     }
587     // If we failed to create the temporary, fallback to writing to the file
588     // directly. This handles the corner case where we cannot write to the
589     // directory, but can write to the file.
590   }
591 
592   if (!OS) {
593     OSFile = OutFile;
594     OS.reset(new llvm::raw_fd_ostream(
595         OSFile.c_str(), Error,
596         (Binary ? llvm::sys::fs::F_None : llvm::sys::fs::F_Text)));
597     if (!Error.empty())
598       return 0;
599   }
600 
601   // Make sure the out stream file gets removed if we crash.
602   if (RemoveFileOnSignal)
603     llvm::sys::RemoveFileOnSignal(OSFile);
604 
605   if (ResultPathName)
606     *ResultPathName = OutFile;
607   if (TempPathName)
608     *TempPathName = TempFile;
609 
610   return OS.take();
611 }
612 
613 // Initialization Utilities
614 
615 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
616   return InitializeSourceManager(Input, getDiagnostics(),
617                                  getFileManager(), getSourceManager(),
618                                  getFrontendOpts());
619 }
620 
621 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
622                                                DiagnosticsEngine &Diags,
623                                                FileManager &FileMgr,
624                                                SourceManager &SourceMgr,
625                                                const FrontendOptions &Opts) {
626   SrcMgr::CharacteristicKind
627     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
628 
629   if (Input.isBuffer()) {
630     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
631     assert(!SourceMgr.getMainFileID().isInvalid() &&
632            "Couldn't establish MainFileID!");
633     return true;
634   }
635 
636   StringRef InputFile = Input.getFile();
637 
638   // Figure out where to get and map in the main file.
639   if (InputFile != "-") {
640     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
641     if (!File) {
642       Diags.Report(diag::err_fe_error_reading) << InputFile;
643       return false;
644     }
645 
646     // The natural SourceManager infrastructure can't currently handle named
647     // pipes, but we would at least like to accept them for the main
648     // file. Detect them here, read them with the volatile flag so FileMgr will
649     // pick up the correct size, and simply override their contents as we do for
650     // STDIN.
651     if (File->isNamedPipe()) {
652       std::string ErrorStr;
653       if (llvm::MemoryBuffer *MB =
654               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
655         // Create a new virtual file that will have the correct size.
656         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
657         SourceMgr.overrideFileContents(File, MB);
658       } else {
659         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
660         return false;
661       }
662     }
663 
664     SourceMgr.createMainFileID(File, Kind);
665   } else {
666     OwningPtr<llvm::MemoryBuffer> SB;
667     if (llvm::error_code ec = llvm::MemoryBuffer::getSTDIN(SB)) {
668       Diags.Report(diag::err_fe_error_reading_stdin) << ec.message();
669       return false;
670     }
671     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
672                                                    SB->getBufferSize(), 0);
673     SourceMgr.createMainFileID(File, Kind);
674     SourceMgr.overrideFileContents(File, SB.take());
675   }
676 
677   assert(!SourceMgr.getMainFileID().isInvalid() &&
678          "Couldn't establish MainFileID!");
679   return true;
680 }
681 
682 // High-Level Operations
683 
684 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
685   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
686   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
687   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
688 
689   // FIXME: Take this as an argument, once all the APIs we used have moved to
690   // taking it as an input instead of hard-coding llvm::errs.
691   raw_ostream &OS = llvm::errs();
692 
693   // Create the target instance.
694   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
695   if (!hasTarget())
696     return false;
697 
698   // Inform the target of the language options.
699   //
700   // FIXME: We shouldn't need to do this, the target should be immutable once
701   // created. This complexity should be lifted elsewhere.
702   getTarget().setForcedLangOptions(getLangOpts());
703 
704   // rewriter project will change target built-in bool type from its default.
705   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
706     getTarget().noSignedCharForObjCBool();
707 
708   // Validate/process some options.
709   if (getHeaderSearchOpts().Verbose)
710     OS << "clang -cc1 version " CLANG_VERSION_STRING
711        << " based upon " << PACKAGE_STRING
712        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
713 
714   if (getFrontendOpts().ShowTimers)
715     createFrontendTimer();
716 
717   if (getFrontendOpts().ShowStats)
718     llvm::EnableStatistics();
719 
720   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
721     // Reset the ID tables if we are reusing the SourceManager.
722     if (hasSourceManager())
723       getSourceManager().clearIDTables();
724 
725     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
726       Act.Execute();
727       Act.EndSourceFile();
728     }
729   }
730 
731   // Notify the diagnostic client that all files were processed.
732   getDiagnostics().getClient()->finish();
733 
734   if (getDiagnosticOpts().ShowCarets) {
735     // We can have multiple diagnostics sharing one diagnostic client.
736     // Get the total number of warnings/errors from the client.
737     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
738     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
739 
740     if (NumWarnings)
741       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
742     if (NumWarnings && NumErrors)
743       OS << " and ";
744     if (NumErrors)
745       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
746     if (NumWarnings || NumErrors)
747       OS << " generated.\n";
748   }
749 
750   if (getFrontendOpts().ShowStats && hasFileManager()) {
751     getFileManager().PrintStats();
752     OS << "\n";
753   }
754 
755   return !getDiagnostics().getClient()->getNumErrors();
756 }
757 
758 /// \brief Determine the appropriate source input kind based on language
759 /// options.
760 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
761   if (LangOpts.OpenCL)
762     return IK_OpenCL;
763   if (LangOpts.CUDA)
764     return IK_CUDA;
765   if (LangOpts.ObjC1)
766     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
767   return LangOpts.CPlusPlus? IK_CXX : IK_C;
768 }
769 
770 /// \brief Compile a module file for the given module, using the options
771 /// provided by the importing compiler instance.
772 static void compileModule(CompilerInstance &ImportingInstance,
773                           SourceLocation ImportLoc,
774                           Module *Module,
775                           StringRef ModuleFileName) {
776   // FIXME: have LockFileManager return an error_code so that we can
777   // avoid the mkdir when the directory already exists.
778   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
779   llvm::sys::fs::create_directories(Dir);
780 
781   llvm::LockFileManager Locked(ModuleFileName);
782   switch (Locked) {
783   case llvm::LockFileManager::LFS_Error:
784     return;
785 
786   case llvm::LockFileManager::LFS_Owned:
787     // We're responsible for building the module ourselves. Do so below.
788     break;
789 
790   case llvm::LockFileManager::LFS_Shared:
791     // Someone else is responsible for building the module. Wait for them to
792     // finish.
793     Locked.waitForUnlock();
794     return;
795   }
796 
797   ModuleMap &ModMap
798     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
799 
800   // Construct a compiler invocation for creating this module.
801   IntrusiveRefCntPtr<CompilerInvocation> Invocation
802     (new CompilerInvocation(ImportingInstance.getInvocation()));
803 
804   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
805 
806   // For any options that aren't intended to affect how a module is built,
807   // reset them to their default values.
808   Invocation->getLangOpts()->resetNonModularOptions();
809   PPOpts.resetNonModularOptions();
810 
811   // Remove any macro definitions that are explicitly ignored by the module.
812   // They aren't supposed to affect how the module is built anyway.
813   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
814   PPOpts.Macros.erase(
815       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
816                      [&HSOpts](const std::pair<std::string, bool> &def) {
817         StringRef MacroDef = def.first;
818         return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
819       }),
820       PPOpts.Macros.end());
821 
822   // Note the name of the module we're building.
823   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
824 
825   // Make sure that the failed-module structure has been allocated in
826   // the importing instance, and propagate the pointer to the newly-created
827   // instance.
828   PreprocessorOptions &ImportingPPOpts
829     = ImportingInstance.getInvocation().getPreprocessorOpts();
830   if (!ImportingPPOpts.FailedModules)
831     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
832   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
833 
834   // If there is a module map file, build the module using the module map.
835   // Set up the inputs/outputs so that we build the module from its umbrella
836   // header.
837   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
838   FrontendOpts.OutputFile = ModuleFileName.str();
839   FrontendOpts.DisableFree = false;
840   FrontendOpts.GenerateGlobalModuleIndex = false;
841   FrontendOpts.Inputs.clear();
842   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
843 
844   // Don't free the remapped file buffers; they are owned by our caller.
845   PPOpts.RetainRemappedFileBuffers = true;
846 
847   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
848   assert(ImportingInstance.getInvocation().getModuleHash() ==
849          Invocation->getModuleHash() && "Module hash mismatch!");
850 
851   // Construct a compiler instance that will be used to actually create the
852   // module.
853   CompilerInstance Instance;
854   Instance.setInvocation(&*Invocation);
855 
856   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
857                                    ImportingInstance.getDiagnosticClient()),
858                              /*ShouldOwnClient=*/true);
859 
860   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
861 
862   // Note that this module is part of the module build stack, so that we
863   // can detect cycles in the module graph.
864   Instance.setFileManager(&ImportingInstance.getFileManager());
865   Instance.createSourceManager(Instance.getFileManager());
866   SourceManager &SourceMgr = Instance.getSourceManager();
867   SourceMgr.setModuleBuildStack(
868     ImportingInstance.getSourceManager().getModuleBuildStack());
869   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
870     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
871 
872   // Get or create the module map that we'll use to build this module.
873   std::string InferredModuleMapContent;
874   if (const FileEntry *ModuleMapFile =
875           ModMap.getContainingModuleMapFile(Module)) {
876     // Use the module map where this module resides.
877     FrontendOpts.Inputs.push_back(
878         FrontendInputFile(ModuleMapFile->getName(), IK));
879   } else {
880     llvm::raw_string_ostream OS(InferredModuleMapContent);
881     Module->print(OS);
882     OS.flush();
883     FrontendOpts.Inputs.push_back(
884         FrontendInputFile("__inferred_module.map", IK));
885 
886     const llvm::MemoryBuffer *ModuleMapBuffer =
887         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
888     ModuleMapFile = Instance.getFileManager().getVirtualFile(
889         "__inferred_module.map", InferredModuleMapContent.size(), 0);
890     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
891   }
892 
893   // Construct a module-generating action.
894   GenerateModuleAction CreateModuleAction(Module->IsSystem);
895 
896   // Execute the action to actually build the module in-place. Use a separate
897   // thread so that we get a stack large enough.
898   const unsigned ThreadStackSize = 8 << 20;
899   llvm::CrashRecoveryContext CRC;
900   CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
901                         ThreadStackSize);
902 
903   // Delete the temporary module map file.
904   // FIXME: Even though we're executing under crash protection, it would still
905   // be nice to do this with RemoveFileOnSignal when we can. However, that
906   // doesn't make sense for all clients, so clean this up manually.
907   Instance.clearOutputFiles(/*EraseFiles=*/true);
908 
909   // We've rebuilt a module. If we're allowed to generate or update the global
910   // module index, record that fact in the importing compiler instance.
911   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
912     ImportingInstance.setBuildGlobalModuleIndex(true);
913   }
914 }
915 
916 /// \brief Diagnose differences between the current definition of the given
917 /// configuration macro and the definition provided on the command line.
918 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
919                              Module *Mod, SourceLocation ImportLoc) {
920   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
921   SourceManager &SourceMgr = PP.getSourceManager();
922 
923   // If this identifier has never had a macro definition, then it could
924   // not have changed.
925   if (!Id->hadMacroDefinition())
926     return;
927 
928   // If this identifier does not currently have a macro definition,
929   // check whether it had one on the command line.
930   if (!Id->hasMacroDefinition()) {
931     MacroDirective::DefInfo LatestDef =
932         PP.getMacroDirectiveHistory(Id)->getDefinition();
933     for (MacroDirective::DefInfo Def = LatestDef; Def;
934            Def = Def.getPreviousDefinition()) {
935       FileID FID = SourceMgr.getFileID(Def.getLocation());
936       if (FID.isInvalid())
937         continue;
938 
939       // We only care about the predefines buffer.
940       if (FID != PP.getPredefinesFileID())
941         continue;
942 
943       // This macro was defined on the command line, then #undef'd later.
944       // Complain.
945       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
946         << true << ConfigMacro << Mod->getFullModuleName();
947       if (LatestDef.isUndefined())
948         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
949           << true;
950       return;
951     }
952 
953     // Okay: no definition in the predefines buffer.
954     return;
955   }
956 
957   // This identifier has a macro definition. Check whether we had a definition
958   // on the command line.
959   MacroDirective::DefInfo LatestDef =
960       PP.getMacroDirectiveHistory(Id)->getDefinition();
961   MacroDirective::DefInfo PredefinedDef;
962   for (MacroDirective::DefInfo Def = LatestDef; Def;
963          Def = Def.getPreviousDefinition()) {
964     FileID FID = SourceMgr.getFileID(Def.getLocation());
965     if (FID.isInvalid())
966       continue;
967 
968     // We only care about the predefines buffer.
969     if (FID != PP.getPredefinesFileID())
970       continue;
971 
972     PredefinedDef = Def;
973     break;
974   }
975 
976   // If there was no definition for this macro in the predefines buffer,
977   // complain.
978   if (!PredefinedDef ||
979       (!PredefinedDef.getLocation().isValid() &&
980        PredefinedDef.getUndefLocation().isValid())) {
981     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
982       << false << ConfigMacro << Mod->getFullModuleName();
983     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
984       << false;
985     return;
986   }
987 
988   // If the current macro definition is the same as the predefined macro
989   // definition, it's okay.
990   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
991       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
992                                               /*Syntactically=*/true))
993     return;
994 
995   // The macro definitions differ.
996   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
997     << false << ConfigMacro << Mod->getFullModuleName();
998   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
999     << false;
1000 }
1001 
1002 /// \brief Write a new timestamp file with the given path.
1003 static void writeTimestampFile(StringRef TimestampFile) {
1004   std::string ErrorInfo;
1005   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1006                            llvm::sys::fs::F_None);
1007 }
1008 
1009 /// \brief Prune the module cache of modules that haven't been accessed in
1010 /// a long time.
1011 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1012   struct stat StatBuf;
1013   llvm::SmallString<128> TimestampFile;
1014   TimestampFile = HSOpts.ModuleCachePath;
1015   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1016 
1017   // Try to stat() the timestamp file.
1018   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1019     // If the timestamp file wasn't there, create one now.
1020     if (errno == ENOENT) {
1021       writeTimestampFile(TimestampFile);
1022     }
1023     return;
1024   }
1025 
1026   // Check whether the time stamp is older than our pruning interval.
1027   // If not, do nothing.
1028   time_t TimeStampModTime = StatBuf.st_mtime;
1029   time_t CurrentTime = time(0);
1030   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1031     return;
1032 
1033   // Write a new timestamp file so that nobody else attempts to prune.
1034   // There is a benign race condition here, if two Clang instances happen to
1035   // notice at the same time that the timestamp is out-of-date.
1036   writeTimestampFile(TimestampFile);
1037 
1038   // Walk the entire module cache, looking for unused module files and module
1039   // indices.
1040   llvm::error_code EC;
1041   SmallString<128> ModuleCachePathNative;
1042   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1043   for (llvm::sys::fs::directory_iterator
1044          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1045        Dir != DirEnd && !EC; Dir.increment(EC)) {
1046     // If we don't have a directory, there's nothing to look into.
1047     if (!llvm::sys::fs::is_directory(Dir->path()))
1048       continue;
1049 
1050     // Walk all of the files within this directory.
1051     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1052          File != FileEnd && !EC; File.increment(EC)) {
1053       // We only care about module and global module index files.
1054       StringRef Extension = llvm::sys::path::extension(File->path());
1055       if (Extension != ".pcm" && Extension != ".timestamp" &&
1056           llvm::sys::path::filename(File->path()) != "modules.idx")
1057         continue;
1058 
1059       // Look at this file. If we can't stat it, there's nothing interesting
1060       // there.
1061       if (::stat(File->path().c_str(), &StatBuf))
1062         continue;
1063 
1064       // If the file has been used recently enough, leave it there.
1065       time_t FileAccessTime = StatBuf.st_atime;
1066       if (CurrentTime - FileAccessTime <=
1067               time_t(HSOpts.ModuleCachePruneAfter)) {
1068         continue;
1069       }
1070 
1071       // Remove the file.
1072       llvm::sys::fs::remove(File->path());
1073 
1074       // Remove the timestamp file.
1075       std::string TimpestampFilename = File->path() + ".timestamp";
1076       llvm::sys::fs::remove(TimpestampFilename);
1077     }
1078 
1079     // If we removed all of the files in the directory, remove the directory
1080     // itself.
1081     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1082             llvm::sys::fs::directory_iterator() && !EC)
1083       llvm::sys::fs::remove(Dir->path());
1084   }
1085 }
1086 
1087 ModuleLoadResult
1088 CompilerInstance::loadModule(SourceLocation ImportLoc,
1089                              ModuleIdPath Path,
1090                              Module::NameVisibilityKind Visibility,
1091                              bool IsInclusionDirective) {
1092   // Determine what file we're searching from.
1093   StringRef ModuleName = Path[0].first->getName();
1094   SourceLocation ModuleNameLoc = Path[0].second;
1095 
1096   // If we've already handled this import, just return the cached result.
1097   // This one-element cache is important to eliminate redundant diagnostics
1098   // when both the preprocessor and parser see the same import declaration.
1099   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1100     // Make the named module visible.
1101     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1102       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1103                                        ImportLoc, /*Complain=*/false);
1104     return LastModuleImportResult;
1105   }
1106 
1107   clang::Module *Module = 0;
1108 
1109   // If we don't already have information on this module, load the module now.
1110   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1111     = KnownModules.find(Path[0].first);
1112   if (Known != KnownModules.end()) {
1113     // Retrieve the cached top-level module.
1114     Module = Known->second;
1115   } else if (ModuleName == getLangOpts().CurrentModule) {
1116     // This is the module we're building.
1117     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1118     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1119   } else {
1120     // Search for a module with the given name.
1121     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1122     if (!Module) {
1123       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1124       << ModuleName
1125       << SourceRange(ImportLoc, ModuleNameLoc);
1126       ModuleBuildFailed = true;
1127       return ModuleLoadResult();
1128     }
1129 
1130     std::string ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1131 
1132     // If we don't already have an ASTReader, create one now.
1133     if (!ModuleManager) {
1134       if (!hasASTContext())
1135         createASTContext();
1136 
1137       // If we're not recursively building a module, check whether we
1138       // need to prune the module cache.
1139       if (getSourceManager().getModuleBuildStack().empty() &&
1140           getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1141           getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1142         pruneModuleCache(getHeaderSearchOpts());
1143       }
1144 
1145       std::string Sysroot = getHeaderSearchOpts().Sysroot;
1146       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1147       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1148                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1149                                     PPOpts.DisablePCHValidation,
1150                                     /*AllowASTWithCompilerErrors=*/false,
1151                                     /*AllowConfigurationMismatch=*/false,
1152                                     /*ValidateSystemInputs=*/false,
1153                                     getFrontendOpts().UseGlobalModuleIndex);
1154       if (hasASTConsumer()) {
1155         ModuleManager->setDeserializationListener(
1156           getASTConsumer().GetASTDeserializationListener());
1157         getASTContext().setASTMutationListener(
1158           getASTConsumer().GetASTMutationListener());
1159       }
1160       getASTContext().setExternalSource(ModuleManager);
1161       if (hasSema())
1162         ModuleManager->InitializeSema(getSema());
1163       if (hasASTConsumer())
1164         ModuleManager->StartTranslationUnit(&getASTConsumer());
1165     }
1166 
1167     if (TheDependencyFileGenerator)
1168       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
1169 
1170     // Try to load the module file.
1171     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1172     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1173                                    ImportLoc, ARRFlags)) {
1174     case ASTReader::Success:
1175       break;
1176 
1177     case ASTReader::OutOfDate:
1178     case ASTReader::Missing: {
1179       // The module file is missing or out-of-date. Build it.
1180       assert(Module && "missing module file");
1181       // Check whether there is a cycle in the module graph.
1182       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1183       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1184       for (; Pos != PosEnd; ++Pos) {
1185         if (Pos->first == ModuleName)
1186           break;
1187       }
1188 
1189       if (Pos != PosEnd) {
1190         SmallString<256> CyclePath;
1191         for (; Pos != PosEnd; ++Pos) {
1192           CyclePath += Pos->first;
1193           CyclePath += " -> ";
1194         }
1195         CyclePath += ModuleName;
1196 
1197         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1198           << ModuleName << CyclePath;
1199         return ModuleLoadResult();
1200       }
1201 
1202       // Check whether we have already attempted to build this module (but
1203       // failed).
1204       if (getPreprocessorOpts().FailedModules &&
1205           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1206         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1207           << ModuleName
1208           << SourceRange(ImportLoc, ModuleNameLoc);
1209         ModuleBuildFailed = true;
1210         return ModuleLoadResult();
1211       }
1212 
1213       // Try to compile the module.
1214       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1215 
1216       // Try to read the module file, now that we've compiled it.
1217       ASTReader::ASTReadResult ReadResult
1218         = ModuleManager->ReadAST(ModuleFileName,
1219                                  serialization::MK_Module, ImportLoc,
1220                                  ASTReader::ARR_Missing);
1221       if (ReadResult != ASTReader::Success) {
1222         if (ReadResult == ASTReader::Missing) {
1223           getDiagnostics().Report(ModuleNameLoc,
1224                                   Module? diag::err_module_not_built
1225                                         : diag::err_module_not_found)
1226             << ModuleName
1227             << SourceRange(ImportLoc, ModuleNameLoc);
1228         }
1229 
1230         if (getPreprocessorOpts().FailedModules)
1231           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1232         KnownModules[Path[0].first] = 0;
1233         ModuleBuildFailed = true;
1234         return ModuleLoadResult();
1235       }
1236 
1237       // Okay, we've rebuilt and now loaded the module.
1238       break;
1239     }
1240 
1241     case ASTReader::VersionMismatch:
1242     case ASTReader::ConfigurationMismatch:
1243     case ASTReader::HadErrors:
1244       ModuleLoader::HadFatalFailure = true;
1245       // FIXME: The ASTReader will already have complained, but can we showhorn
1246       // that diagnostic information into a more useful form?
1247       KnownModules[Path[0].first] = 0;
1248       return ModuleLoadResult();
1249 
1250     case ASTReader::Failure:
1251       ModuleLoader::HadFatalFailure = true;
1252       // Already complained, but note now that we failed.
1253       KnownModules[Path[0].first] = 0;
1254       ModuleBuildFailed = true;
1255       return ModuleLoadResult();
1256     }
1257 
1258     // Cache the result of this top-level module lookup for later.
1259     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1260   }
1261 
1262   // If we never found the module, fail.
1263   if (!Module)
1264     return ModuleLoadResult();
1265 
1266   // Verify that the rest of the module path actually corresponds to
1267   // a submodule.
1268   if (Path.size() > 1) {
1269     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1270       StringRef Name = Path[I].first->getName();
1271       clang::Module *Sub = Module->findSubmodule(Name);
1272 
1273       if (!Sub) {
1274         // Attempt to perform typo correction to find a module name that works.
1275         SmallVector<StringRef, 2> Best;
1276         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1277 
1278         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1279                                             JEnd = Module->submodule_end();
1280              J != JEnd; ++J) {
1281           unsigned ED = Name.edit_distance((*J)->Name,
1282                                            /*AllowReplacements=*/true,
1283                                            BestEditDistance);
1284           if (ED <= BestEditDistance) {
1285             if (ED < BestEditDistance) {
1286               Best.clear();
1287               BestEditDistance = ED;
1288             }
1289 
1290             Best.push_back((*J)->Name);
1291           }
1292         }
1293 
1294         // If there was a clear winner, user it.
1295         if (Best.size() == 1) {
1296           getDiagnostics().Report(Path[I].second,
1297                                   diag::err_no_submodule_suggest)
1298             << Path[I].first << Module->getFullModuleName() << Best[0]
1299             << SourceRange(Path[0].second, Path[I-1].second)
1300             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1301                                             Best[0]);
1302 
1303           Sub = Module->findSubmodule(Best[0]);
1304         }
1305       }
1306 
1307       if (!Sub) {
1308         // No submodule by this name. Complain, and don't look for further
1309         // submodules.
1310         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1311           << Path[I].first << Module->getFullModuleName()
1312           << SourceRange(Path[0].second, Path[I-1].second);
1313         break;
1314       }
1315 
1316       Module = Sub;
1317     }
1318   }
1319 
1320   // Make the named module visible, if it's not already part of the module
1321   // we are parsing.
1322   if (ModuleName != getLangOpts().CurrentModule) {
1323     if (!Module->IsFromModuleFile) {
1324       // We have an umbrella header or directory that doesn't actually include
1325       // all of the headers within the directory it covers. Complain about
1326       // this missing submodule and recover by forgetting that we ever saw
1327       // this submodule.
1328       // FIXME: Should we detect this at module load time? It seems fairly
1329       // expensive (and rare).
1330       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1331         << Module->getFullModuleName()
1332         << SourceRange(Path.front().second, Path.back().second);
1333 
1334       return ModuleLoadResult(0, true);
1335     }
1336 
1337     // Check whether this module is available.
1338     clang::Module::Requirement Requirement;
1339     clang::Module::HeaderDirective MissingHeader;
1340     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
1341                              MissingHeader)) {
1342       if (MissingHeader.FileNameLoc.isValid()) {
1343         getDiagnostics().Report(MissingHeader.FileNameLoc,
1344                                 diag::err_module_header_missing)
1345           << MissingHeader.IsUmbrella << MissingHeader.FileName;
1346       } else {
1347         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1348           << Module->getFullModuleName()
1349           << Requirement.second << Requirement.first
1350           << SourceRange(Path.front().second, Path.back().second);
1351       }
1352       LastModuleImportLoc = ImportLoc;
1353       LastModuleImportResult = ModuleLoadResult();
1354       return ModuleLoadResult();
1355     }
1356 
1357     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1358                                      /*Complain=*/true);
1359   }
1360 
1361   // Check for any configuration macros that have changed.
1362   clang::Module *TopModule = Module->getTopLevelModule();
1363   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1364     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1365                      Module, ImportLoc);
1366   }
1367 
1368   // If this module import was due to an inclusion directive, create an
1369   // implicit import declaration to capture it in the AST.
1370   if (IsInclusionDirective && hasASTContext()) {
1371     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1372     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1373                                                      ImportLoc, Module,
1374                                                      Path.back().second);
1375     TU->addDecl(ImportD);
1376     if (Consumer)
1377       Consumer->HandleImplicitImportDecl(ImportD);
1378   }
1379 
1380   LastModuleImportLoc = ImportLoc;
1381   LastModuleImportResult = ModuleLoadResult(Module, false);
1382   return LastModuleImportResult;
1383 }
1384 
1385 void CompilerInstance::makeModuleVisible(Module *Mod,
1386                                          Module::NameVisibilityKind Visibility,
1387                                          SourceLocation ImportLoc,
1388                                          bool Complain){
1389   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1390 }
1391 
1392