xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision 2d94bbb0c014880b67298aac8519cb60416feaf8)
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 "clang/Serialization/GlobalModuleIndex.h"
35 #include "llvm/ADT/Statistic.h"
36 #include "llvm/Config/config.h"
37 #include "llvm/Support/CrashRecoveryContext.h"
38 #include "llvm/Support/FileSystem.h"
39 #include "llvm/Support/Host.h"
40 #include "llvm/Support/LockFileManager.h"
41 #include "llvm/Support/MemoryBuffer.h"
42 #include "llvm/Support/Path.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(bool BuildingModule)
54   : ModuleLoader(BuildingModule),
55     Invocation(new CompilerInvocation()), ModuleManager(0),
56     BuildGlobalModuleIndex(false), HaveFullGlobalModuleIndex(false),
57     ModuleBuildFailed(false) {
58 }
59 
60 CompilerInstance::~CompilerInstance() {
61   assert(OutputFiles.empty() && "Still output files in flight?");
62 }
63 
64 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
65   Invocation = Value;
66 }
67 
68 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
69   return (BuildGlobalModuleIndex ||
70           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
71            getFrontendOpts().GenerateGlobalModuleIndex)) &&
72          !ModuleBuildFailed;
73 }
74 
75 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
76   Diagnostics = Value;
77 }
78 
79 void CompilerInstance::setTarget(TargetInfo *Value) {
80   Target = Value;
81 }
82 
83 void CompilerInstance::setFileManager(FileManager *Value) {
84   FileMgr = Value;
85   if (Value)
86     VirtualFileSystem = Value->getVirtualFileSystem();
87   else
88     VirtualFileSystem.reset();
89 }
90 
91 void CompilerInstance::setSourceManager(SourceManager *Value) {
92   SourceMgr = Value;
93 }
94 
95 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
96 
97 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
98 
99 void CompilerInstance::setSema(Sema *S) {
100   TheSema.reset(S);
101 }
102 
103 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
104   Consumer.reset(Value);
105 }
106 
107 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
108   CompletionConsumer.reset(Value);
109 }
110 
111 IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
112   return ModuleManager;
113 }
114 void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
115   ModuleManager = Reader;
116 }
117 
118 // Diagnostics
119 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
120                                const CodeGenOptions *CodeGenOpts,
121                                DiagnosticsEngine &Diags) {
122   std::string ErrorInfo;
123   bool OwnsStream = false;
124   raw_ostream *OS = &llvm::errs();
125   if (DiagOpts->DiagnosticLogFile != "-") {
126     // Create the output stream.
127     llvm::raw_fd_ostream *FileOS(new llvm::raw_fd_ostream(
128         DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
129         llvm::sys::fs::F_Append | llvm::sys::fs::F_Text));
130     if (!ErrorInfo.empty()) {
131       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
132         << DiagOpts->DiagnosticLogFile << ErrorInfo;
133     } else {
134       FileOS->SetUnbuffered();
135       FileOS->SetUseAtomicWrites(true);
136       OS = FileOS;
137       OwnsStream = true;
138     }
139   }
140 
141   // Chain in the diagnostic client which will log the diagnostics.
142   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
143                                                           OwnsStream);
144   if (CodeGenOpts)
145     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
146   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
147 }
148 
149 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
150                                        DiagnosticsEngine &Diags,
151                                        StringRef OutputFile) {
152   std::string ErrorInfo;
153   std::unique_ptr<llvm::raw_fd_ostream> OS;
154   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
155                                     llvm::sys::fs::F_None));
156 
157   if (!ErrorInfo.empty()) {
158     Diags.Report(diag::warn_fe_serialized_diag_failure)
159       << OutputFile << ErrorInfo;
160     return;
161   }
162 
163   DiagnosticConsumer *SerializedConsumer =
164       clang::serialized_diags::create(OS.release(), DiagOpts);
165 
166   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
167                                                 SerializedConsumer));
168 }
169 
170 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
171                                          bool ShouldOwnClient) {
172   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
173                                   ShouldOwnClient, &getCodeGenOpts());
174 }
175 
176 IntrusiveRefCntPtr<DiagnosticsEngine>
177 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
178                                     DiagnosticConsumer *Client,
179                                     bool ShouldOwnClient,
180                                     const CodeGenOptions *CodeGenOpts) {
181   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
182   IntrusiveRefCntPtr<DiagnosticsEngine>
183       Diags(new DiagnosticsEngine(DiagID, Opts));
184 
185   // Create the diagnostic client for reporting errors or for
186   // implementing -verify.
187   if (Client) {
188     Diags->setClient(Client, ShouldOwnClient);
189   } else
190     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
191 
192   // Chain in -verify checker, if requested.
193   if (Opts->VerifyDiagnostics)
194     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
195 
196   // Chain in -diagnostic-log-file dumper, if requested.
197   if (!Opts->DiagnosticLogFile.empty())
198     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
199 
200   if (!Opts->DiagnosticSerializationFile.empty())
201     SetupSerializedDiagnostics(Opts, *Diags,
202                                Opts->DiagnosticSerializationFile);
203 
204   // Configure our handling of diagnostics.
205   ProcessWarningOptions(*Diags, *Opts);
206 
207   return Diags;
208 }
209 
210 // File Manager
211 
212 void CompilerInstance::createFileManager() {
213   if (!hasVirtualFileSystem()) {
214     // TODO: choose the virtual file system based on the CompilerInvocation.
215     setVirtualFileSystem(vfs::getRealFileSystem());
216   }
217   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
218 }
219 
220 // Source Manager
221 
222 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
223   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
224 }
225 
226 // Preprocessor
227 
228 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
229   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
230 
231   // Create a PTH manager if we are using some form of a token cache.
232   PTHManager *PTHMgr = 0;
233   if (!PPOpts.TokenCache.empty())
234     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
235 
236   // Create the Preprocessor.
237   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
238                                               getSourceManager(),
239                                               getDiagnostics(),
240                                               getLangOpts(),
241                                               &getTarget());
242   PP = new Preprocessor(&getPreprocessorOpts(),
243                         getDiagnostics(), getLangOpts(), &getTarget(),
244                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
245                         /*OwnsHeaderSearch=*/true,
246                         /*DelayInitialization=*/false,
247                         /*IncrProcessing=*/false,
248                         TUKind);
249 
250   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
251   // That argument is used as the IdentifierInfoLookup argument to
252   // IdentifierTable's ctor.
253   if (PTHMgr) {
254     PTHMgr->setPreprocessor(&*PP);
255     PP->setPTHManager(PTHMgr);
256   }
257 
258   if (PPOpts.DetailedRecord)
259     PP->createPreprocessingRecord();
260 
261   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
262 
263   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
264 
265   // Set up the module path, including the hash for the
266   // module-creation options.
267   SmallString<256> SpecificModuleCache(
268                            getHeaderSearchOpts().ModuleCachePath);
269   if (!getHeaderSearchOpts().DisableModuleHash)
270     llvm::sys::path::append(SpecificModuleCache,
271                             getInvocation().getModuleHash());
272   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
273 
274   // Handle generating dependencies, if requested.
275   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
276   if (!DepOpts.OutputFile.empty())
277     TheDependencyFileGenerator.reset(
278         DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
279   if (!DepOpts.DOTOutputFile.empty())
280     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
281                              getHeaderSearchOpts().Sysroot);
282 
283 
284   // Handle generating header include information, if requested.
285   if (DepOpts.ShowHeaderIncludes)
286     AttachHeaderIncludeGen(*PP);
287   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
288     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
289     if (OutputPath == "-")
290       OutputPath = "";
291     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
292                            /*ShowDepth=*/false);
293   }
294 
295   if (DepOpts.PrintShowIncludes) {
296     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
297                            /*ShowDepth=*/true, /*MSStyle=*/true);
298   }
299 }
300 
301 // ASTContext
302 
303 void CompilerInstance::createASTContext() {
304   Preprocessor &PP = getPreprocessor();
305   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
306                            &getTarget(), PP.getIdentifierTable(),
307                            PP.getSelectorTable(), PP.getBuiltinInfo(),
308                            /*size_reserve=*/ 0);
309 }
310 
311 // ExternalASTSource
312 
313 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
314                                                   bool DisablePCHValidation,
315                                                 bool AllowPCHWithCompilerErrors,
316                                                  void *DeserializationListener){
317   IntrusiveRefCntPtr<ExternalASTSource> Source;
318   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
319   Source = createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
320                                           DisablePCHValidation,
321                                           AllowPCHWithCompilerErrors,
322                                           getPreprocessor(), getASTContext(),
323                                           DeserializationListener,
324                                           Preamble,
325                                        getFrontendOpts().UseGlobalModuleIndex);
326   ModuleManager = static_cast<ASTReader*>(Source.getPtr());
327   getASTContext().setExternalSource(Source);
328 }
329 
330 ExternalASTSource *
331 CompilerInstance::createPCHExternalASTSource(StringRef Path,
332                                              const std::string &Sysroot,
333                                              bool DisablePCHValidation,
334                                              bool AllowPCHWithCompilerErrors,
335                                              Preprocessor &PP,
336                                              ASTContext &Context,
337                                              void *DeserializationListener,
338                                              bool Preamble,
339                                              bool UseGlobalModuleIndex) {
340   HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
341 
342   std::unique_ptr<ASTReader> Reader;
343   Reader.reset(new ASTReader(PP, Context,
344                              Sysroot.empty() ? "" : Sysroot.c_str(),
345                              DisablePCHValidation,
346                              AllowPCHWithCompilerErrors,
347                              /*AllowConfigurationMismatch*/false,
348                              HSOpts.ModulesValidateSystemHeaders,
349                              UseGlobalModuleIndex));
350 
351   Reader->setDeserializationListener(
352             static_cast<ASTDeserializationListener *>(DeserializationListener));
353   switch (Reader->ReadAST(Path,
354                           Preamble ? serialization::MK_Preamble
355                                    : serialization::MK_PCH,
356                           SourceLocation(),
357                           ASTReader::ARR_None)) {
358   case ASTReader::Success:
359     // Set the predefines buffer as suggested by the PCH reader. Typically, the
360     // predefines buffer will be empty.
361     PP.setPredefines(Reader->getSuggestedPredefines());
362     return Reader.release();
363 
364   case ASTReader::Failure:
365     // Unrecoverable failure: don't even try to process the input file.
366     break;
367 
368   case ASTReader::Missing:
369   case ASTReader::OutOfDate:
370   case ASTReader::VersionMismatch:
371   case ASTReader::ConfigurationMismatch:
372   case ASTReader::HadErrors:
373     // No suitable PCH file could be found. Return an error.
374     break;
375   }
376 
377   return 0;
378 }
379 
380 // Code Completion
381 
382 static bool EnableCodeCompletion(Preprocessor &PP,
383                                  const std::string &Filename,
384                                  unsigned Line,
385                                  unsigned Column) {
386   // Tell the source manager to chop off the given file at a specific
387   // line and column.
388   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
389   if (!Entry) {
390     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
391       << Filename;
392     return true;
393   }
394 
395   // Truncate the named file at the given line/column.
396   PP.SetCodeCompletionPoint(Entry, Line, Column);
397   return false;
398 }
399 
400 void CompilerInstance::createCodeCompletionConsumer() {
401   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
402   if (!CompletionConsumer) {
403     setCodeCompletionConsumer(
404       createCodeCompletionConsumer(getPreprocessor(),
405                                    Loc.FileName, Loc.Line, Loc.Column,
406                                    getFrontendOpts().CodeCompleteOpts,
407                                    llvm::outs()));
408     if (!CompletionConsumer)
409       return;
410   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
411                                   Loc.Line, Loc.Column)) {
412     setCodeCompletionConsumer(0);
413     return;
414   }
415 
416   if (CompletionConsumer->isOutputBinary() &&
417       llvm::sys::ChangeStdoutToBinary()) {
418     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
419     setCodeCompletionConsumer(0);
420   }
421 }
422 
423 void CompilerInstance::createFrontendTimer() {
424   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
425 }
426 
427 CodeCompleteConsumer *
428 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
429                                                const std::string &Filename,
430                                                unsigned Line,
431                                                unsigned Column,
432                                                const CodeCompleteOptions &Opts,
433                                                raw_ostream &OS) {
434   if (EnableCodeCompletion(PP, Filename, Line, Column))
435     return 0;
436 
437   // Set up the creation routine for code-completion.
438   return new PrintingCodeCompleteConsumer(Opts, OS);
439 }
440 
441 void CompilerInstance::createSema(TranslationUnitKind TUKind,
442                                   CodeCompleteConsumer *CompletionConsumer) {
443   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
444                          TUKind, CompletionConsumer));
445 }
446 
447 // Output Files
448 
449 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
450   assert(OutFile.OS && "Attempt to add empty stream to output list!");
451   OutputFiles.push_back(OutFile);
452 }
453 
454 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
455   for (std::list<OutputFile>::iterator
456          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
457     delete it->OS;
458     if (!it->TempFilename.empty()) {
459       if (EraseFiles) {
460         llvm::sys::fs::remove(it->TempFilename);
461       } else {
462         SmallString<128> NewOutFile(it->Filename);
463 
464         // If '-working-directory' was passed, the output filename should be
465         // relative to that.
466         FileMgr->FixupRelativePath(NewOutFile);
467         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
468                                                         NewOutFile.str())) {
469           getDiagnostics().Report(diag::err_unable_to_rename_temp)
470             << it->TempFilename << it->Filename << ec.message();
471 
472           llvm::sys::fs::remove(it->TempFilename);
473         }
474       }
475     } else if (!it->Filename.empty() && EraseFiles)
476       llvm::sys::fs::remove(it->Filename);
477 
478   }
479   OutputFiles.clear();
480 }
481 
482 llvm::raw_fd_ostream *
483 CompilerInstance::createDefaultOutputFile(bool Binary,
484                                           StringRef InFile,
485                                           StringRef Extension) {
486   return createOutputFile(getFrontendOpts().OutputFile, Binary,
487                           /*RemoveFileOnSignal=*/true, InFile, Extension,
488                           /*UseTemporary=*/true);
489 }
490 
491 llvm::raw_fd_ostream *
492 CompilerInstance::createOutputFile(StringRef OutputPath,
493                                    bool Binary, bool RemoveFileOnSignal,
494                                    StringRef InFile,
495                                    StringRef Extension,
496                                    bool UseTemporary,
497                                    bool CreateMissingDirectories) {
498   std::string Error, OutputPathName, TempPathName;
499   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
500                                               RemoveFileOnSignal,
501                                               InFile, Extension,
502                                               UseTemporary,
503                                               CreateMissingDirectories,
504                                               &OutputPathName,
505                                               &TempPathName);
506   if (!OS) {
507     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
508       << OutputPath << Error;
509     return 0;
510   }
511 
512   // Add the output file -- but don't try to remove "-", since this means we are
513   // using stdin.
514   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
515                 TempPathName, OS));
516 
517   return OS;
518 }
519 
520 llvm::raw_fd_ostream *
521 CompilerInstance::createOutputFile(StringRef OutputPath,
522                                    std::string &Error,
523                                    bool Binary,
524                                    bool RemoveFileOnSignal,
525                                    StringRef InFile,
526                                    StringRef Extension,
527                                    bool UseTemporary,
528                                    bool CreateMissingDirectories,
529                                    std::string *ResultPathName,
530                                    std::string *TempPathName) {
531   assert((!CreateMissingDirectories || UseTemporary) &&
532          "CreateMissingDirectories is only allowed when using temporary files");
533 
534   std::string OutFile, TempFile;
535   if (!OutputPath.empty()) {
536     OutFile = OutputPath;
537   } else if (InFile == "-") {
538     OutFile = "-";
539   } else if (!Extension.empty()) {
540     SmallString<128> Path(InFile);
541     llvm::sys::path::replace_extension(Path, Extension);
542     OutFile = Path.str();
543   } else {
544     OutFile = "-";
545   }
546 
547   std::unique_ptr<llvm::raw_fd_ostream> OS;
548   std::string OSFile;
549 
550   if (UseTemporary) {
551     if (OutFile == "-")
552       UseTemporary = false;
553     else {
554       llvm::sys::fs::file_status Status;
555       llvm::sys::fs::status(OutputPath, Status);
556       if (llvm::sys::fs::exists(Status)) {
557         // Fail early if we can't write to the final destination.
558         if (!llvm::sys::fs::can_write(OutputPath))
559           return 0;
560 
561         // Don't use a temporary if the output is a special file. This handles
562         // things like '-o /dev/null'
563         if (!llvm::sys::fs::is_regular_file(Status))
564           UseTemporary = false;
565       }
566     }
567   }
568 
569   if (UseTemporary) {
570     // Create a temporary file.
571     SmallString<128> TempPath;
572     TempPath = OutFile;
573     TempPath += "-%%%%%%%%";
574     int fd;
575     llvm::error_code EC =
576         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
577 
578     if (CreateMissingDirectories &&
579         EC == llvm::errc::no_such_file_or_directory) {
580       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
581       EC = llvm::sys::fs::create_directories(Parent);
582       if (!EC) {
583         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
584       }
585     }
586 
587     if (!EC) {
588       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
589       OSFile = TempFile = TempPath.str();
590     }
591     // If we failed to create the temporary, fallback to writing to the file
592     // directly. This handles the corner case where we cannot write to the
593     // directory, but can write to the file.
594   }
595 
596   if (!OS) {
597     OSFile = OutFile;
598     OS.reset(new llvm::raw_fd_ostream(
599         OSFile.c_str(), Error,
600         (Binary ? llvm::sys::fs::F_None : llvm::sys::fs::F_Text)));
601     if (!Error.empty())
602       return 0;
603   }
604 
605   // Make sure the out stream file gets removed if we crash.
606   if (RemoveFileOnSignal)
607     llvm::sys::RemoveFileOnSignal(OSFile);
608 
609   if (ResultPathName)
610     *ResultPathName = OutFile;
611   if (TempPathName)
612     *TempPathName = TempFile;
613 
614   return OS.release();
615 }
616 
617 // Initialization Utilities
618 
619 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
620   return InitializeSourceManager(Input, getDiagnostics(),
621                                  getFileManager(), getSourceManager(),
622                                  getFrontendOpts());
623 }
624 
625 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
626                                                DiagnosticsEngine &Diags,
627                                                FileManager &FileMgr,
628                                                SourceManager &SourceMgr,
629                                                const FrontendOptions &Opts) {
630   SrcMgr::CharacteristicKind
631     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
632 
633   if (Input.isBuffer()) {
634     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
635     assert(!SourceMgr.getMainFileID().isInvalid() &&
636            "Couldn't establish MainFileID!");
637     return true;
638   }
639 
640   StringRef InputFile = Input.getFile();
641 
642   // Figure out where to get and map in the main file.
643   if (InputFile != "-") {
644     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
645     if (!File) {
646       Diags.Report(diag::err_fe_error_reading) << InputFile;
647       return false;
648     }
649 
650     // The natural SourceManager infrastructure can't currently handle named
651     // pipes, but we would at least like to accept them for the main
652     // file. Detect them here, read them with the volatile flag so FileMgr will
653     // pick up the correct size, and simply override their contents as we do for
654     // STDIN.
655     if (File->isNamedPipe()) {
656       std::string ErrorStr;
657       if (llvm::MemoryBuffer *MB =
658               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
659         // Create a new virtual file that will have the correct size.
660         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
661         SourceMgr.overrideFileContents(File, MB);
662       } else {
663         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
664         return false;
665       }
666     }
667 
668     SourceMgr.createMainFileID(File, Kind);
669   } else {
670     std::unique_ptr<llvm::MemoryBuffer> SB;
671     if (llvm::error_code ec = llvm::MemoryBuffer::getSTDIN(SB)) {
672       Diags.Report(diag::err_fe_error_reading_stdin) << ec.message();
673       return false;
674     }
675     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
676                                                    SB->getBufferSize(), 0);
677     SourceMgr.createMainFileID(File, Kind);
678     SourceMgr.overrideFileContents(File, SB.release());
679   }
680 
681   assert(!SourceMgr.getMainFileID().isInvalid() &&
682          "Couldn't establish MainFileID!");
683   return true;
684 }
685 
686 // High-Level Operations
687 
688 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
689   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
690   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
691   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
692 
693   // FIXME: Take this as an argument, once all the APIs we used have moved to
694   // taking it as an input instead of hard-coding llvm::errs.
695   raw_ostream &OS = llvm::errs();
696 
697   // Create the target instance.
698   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
699   if (!hasTarget())
700     return false;
701 
702   // Inform the target of the language options.
703   //
704   // FIXME: We shouldn't need to do this, the target should be immutable once
705   // created. This complexity should be lifted elsewhere.
706   getTarget().setForcedLangOptions(getLangOpts());
707 
708   // rewriter project will change target built-in bool type from its default.
709   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
710     getTarget().noSignedCharForObjCBool();
711 
712   // Validate/process some options.
713   if (getHeaderSearchOpts().Verbose)
714     OS << "clang -cc1 version " CLANG_VERSION_STRING
715        << " based upon " << PACKAGE_STRING
716        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
717 
718   if (getFrontendOpts().ShowTimers)
719     createFrontendTimer();
720 
721   if (getFrontendOpts().ShowStats)
722     llvm::EnableStatistics();
723 
724   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
725     // Reset the ID tables if we are reusing the SourceManager.
726     if (hasSourceManager())
727       getSourceManager().clearIDTables();
728 
729     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
730       Act.Execute();
731       Act.EndSourceFile();
732     }
733   }
734 
735   // Notify the diagnostic client that all files were processed.
736   getDiagnostics().getClient()->finish();
737 
738   if (getDiagnosticOpts().ShowCarets) {
739     // We can have multiple diagnostics sharing one diagnostic client.
740     // Get the total number of warnings/errors from the client.
741     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
742     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
743 
744     if (NumWarnings)
745       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
746     if (NumWarnings && NumErrors)
747       OS << " and ";
748     if (NumErrors)
749       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
750     if (NumWarnings || NumErrors)
751       OS << " generated.\n";
752   }
753 
754   if (getFrontendOpts().ShowStats && hasFileManager()) {
755     getFileManager().PrintStats();
756     OS << "\n";
757   }
758 
759   return !getDiagnostics().getClient()->getNumErrors();
760 }
761 
762 /// \brief Determine the appropriate source input kind based on language
763 /// options.
764 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
765   if (LangOpts.OpenCL)
766     return IK_OpenCL;
767   if (LangOpts.CUDA)
768     return IK_CUDA;
769   if (LangOpts.ObjC1)
770     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
771   return LangOpts.CPlusPlus? IK_CXX : IK_C;
772 }
773 
774 /// \brief Compile a module file for the given module, using the options
775 /// provided by the importing compiler instance.
776 static void compileModuleImpl(CompilerInstance &ImportingInstance,
777                           SourceLocation ImportLoc,
778                           Module *Module,
779                           StringRef ModuleFileName) {
780   ModuleMap &ModMap
781     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
782 
783   // Construct a compiler invocation for creating this module.
784   IntrusiveRefCntPtr<CompilerInvocation> Invocation
785     (new CompilerInvocation(ImportingInstance.getInvocation()));
786 
787   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
788 
789   // For any options that aren't intended to affect how a module is built,
790   // reset them to their default values.
791   Invocation->getLangOpts()->resetNonModularOptions();
792   PPOpts.resetNonModularOptions();
793 
794   // Remove any macro definitions that are explicitly ignored by the module.
795   // They aren't supposed to affect how the module is built anyway.
796   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
797   PPOpts.Macros.erase(
798       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
799                      [&HSOpts](const std::pair<std::string, bool> &def) {
800         StringRef MacroDef = def.first;
801         return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
802       }),
803       PPOpts.Macros.end());
804 
805   // Note the name of the module we're building.
806   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
807 
808   // Make sure that the failed-module structure has been allocated in
809   // the importing instance, and propagate the pointer to the newly-created
810   // instance.
811   PreprocessorOptions &ImportingPPOpts
812     = ImportingInstance.getInvocation().getPreprocessorOpts();
813   if (!ImportingPPOpts.FailedModules)
814     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
815   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
816 
817   // If there is a module map file, build the module using the module map.
818   // Set up the inputs/outputs so that we build the module from its umbrella
819   // header.
820   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
821   FrontendOpts.OutputFile = ModuleFileName.str();
822   FrontendOpts.DisableFree = false;
823   FrontendOpts.GenerateGlobalModuleIndex = false;
824   FrontendOpts.Inputs.clear();
825   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
826 
827   // Don't free the remapped file buffers; they are owned by our caller.
828   PPOpts.RetainRemappedFileBuffers = true;
829 
830   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
831   assert(ImportingInstance.getInvocation().getModuleHash() ==
832          Invocation->getModuleHash() && "Module hash mismatch!");
833 
834   // Construct a compiler instance that will be used to actually create the
835   // module.
836   CompilerInstance Instance(/*BuildingModule=*/true);
837   Instance.setInvocation(&*Invocation);
838 
839   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
840                                    ImportingInstance.getDiagnosticClient()),
841                              /*ShouldOwnClient=*/true);
842 
843   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
844 
845   // Note that this module is part of the module build stack, so that we
846   // can detect cycles in the module graph.
847   Instance.setFileManager(&ImportingInstance.getFileManager());
848   Instance.createSourceManager(Instance.getFileManager());
849   SourceManager &SourceMgr = Instance.getSourceManager();
850   SourceMgr.setModuleBuildStack(
851     ImportingInstance.getSourceManager().getModuleBuildStack());
852   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
853     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
854 
855   // Get or create the module map that we'll use to build this module.
856   std::string InferredModuleMapContent;
857   if (const FileEntry *ModuleMapFile =
858           ModMap.getContainingModuleMapFile(Module)) {
859     // Use the module map where this module resides.
860     FrontendOpts.Inputs.push_back(
861         FrontendInputFile(ModuleMapFile->getName(), IK));
862   } else {
863     llvm::raw_string_ostream OS(InferredModuleMapContent);
864     Module->print(OS);
865     OS.flush();
866     FrontendOpts.Inputs.push_back(
867         FrontendInputFile("__inferred_module.map", IK));
868 
869     const llvm::MemoryBuffer *ModuleMapBuffer =
870         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
871     ModuleMapFile = Instance.getFileManager().getVirtualFile(
872         "__inferred_module.map", InferredModuleMapContent.size(), 0);
873     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
874   }
875 
876   // Construct a module-generating action. Passing through Module->ModuleMap is
877   // safe because the FileManager is shared between the compiler instances.
878   GenerateModuleAction CreateModuleAction(Module->ModuleMap, Module->IsSystem);
879 
880   // Execute the action to actually build the module in-place. Use a separate
881   // thread so that we get a stack large enough.
882   const unsigned ThreadStackSize = 8 << 20;
883   llvm::CrashRecoveryContext CRC;
884   CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
885                         ThreadStackSize);
886 
887   // Delete the temporary module map file.
888   // FIXME: Even though we're executing under crash protection, it would still
889   // be nice to do this with RemoveFileOnSignal when we can. However, that
890   // doesn't make sense for all clients, so clean this up manually.
891   Instance.clearOutputFiles(/*EraseFiles=*/true);
892 
893   // We've rebuilt a module. If we're allowed to generate or update the global
894   // module index, record that fact in the importing compiler instance.
895   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
896     ImportingInstance.setBuildGlobalModuleIndex(true);
897   }
898 }
899 
900 static void compileModule(CompilerInstance &ImportingInstance,
901                           SourceLocation ImportLoc,
902                           Module *Module,
903                           StringRef ModuleFileName) {
904   // FIXME: have LockFileManager return an error_code so that we can
905   // avoid the mkdir when the directory already exists.
906   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
907   llvm::sys::fs::create_directories(Dir);
908 
909   while (1) {
910     llvm::LockFileManager Locked(ModuleFileName);
911     switch (Locked) {
912     case llvm::LockFileManager::LFS_Error:
913       return;
914 
915     case llvm::LockFileManager::LFS_Owned:
916       // We're responsible for building the module ourselves. Do so below.
917       break;
918 
919     case llvm::LockFileManager::LFS_Shared:
920       // Someone else is responsible for building the module. Wait for them to
921       // finish.
922       if (Locked.waitForUnlock() == llvm::LockFileManager::Res_OwnerDied)
923         continue; // try again to get the lock.
924       return;
925     }
926 
927     return compileModuleImpl(ImportingInstance, ImportLoc, Module,
928                              ModuleFileName);
929   }
930 }
931 
932 /// \brief Diagnose differences between the current definition of the given
933 /// configuration macro and the definition provided on the command line.
934 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
935                              Module *Mod, SourceLocation ImportLoc) {
936   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
937   SourceManager &SourceMgr = PP.getSourceManager();
938 
939   // If this identifier has never had a macro definition, then it could
940   // not have changed.
941   if (!Id->hadMacroDefinition())
942     return;
943 
944   // If this identifier does not currently have a macro definition,
945   // check whether it had one on the command line.
946   if (!Id->hasMacroDefinition()) {
947     MacroDirective::DefInfo LatestDef =
948         PP.getMacroDirectiveHistory(Id)->getDefinition();
949     for (MacroDirective::DefInfo Def = LatestDef; Def;
950            Def = Def.getPreviousDefinition()) {
951       FileID FID = SourceMgr.getFileID(Def.getLocation());
952       if (FID.isInvalid())
953         continue;
954 
955       // We only care about the predefines buffer.
956       if (FID != PP.getPredefinesFileID())
957         continue;
958 
959       // This macro was defined on the command line, then #undef'd later.
960       // Complain.
961       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
962         << true << ConfigMacro << Mod->getFullModuleName();
963       if (LatestDef.isUndefined())
964         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
965           << true;
966       return;
967     }
968 
969     // Okay: no definition in the predefines buffer.
970     return;
971   }
972 
973   // This identifier has a macro definition. Check whether we had a definition
974   // on the command line.
975   MacroDirective::DefInfo LatestDef =
976       PP.getMacroDirectiveHistory(Id)->getDefinition();
977   MacroDirective::DefInfo PredefinedDef;
978   for (MacroDirective::DefInfo Def = LatestDef; Def;
979          Def = Def.getPreviousDefinition()) {
980     FileID FID = SourceMgr.getFileID(Def.getLocation());
981     if (FID.isInvalid())
982       continue;
983 
984     // We only care about the predefines buffer.
985     if (FID != PP.getPredefinesFileID())
986       continue;
987 
988     PredefinedDef = Def;
989     break;
990   }
991 
992   // If there was no definition for this macro in the predefines buffer,
993   // complain.
994   if (!PredefinedDef ||
995       (!PredefinedDef.getLocation().isValid() &&
996        PredefinedDef.getUndefLocation().isValid())) {
997     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
998       << false << ConfigMacro << Mod->getFullModuleName();
999     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1000       << false;
1001     return;
1002   }
1003 
1004   // If the current macro definition is the same as the predefined macro
1005   // definition, it's okay.
1006   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
1007       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1008                                               /*Syntactically=*/true))
1009     return;
1010 
1011   // The macro definitions differ.
1012   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1013     << false << ConfigMacro << Mod->getFullModuleName();
1014   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1015     << false;
1016 }
1017 
1018 /// \brief Write a new timestamp file with the given path.
1019 static void writeTimestampFile(StringRef TimestampFile) {
1020   std::string ErrorInfo;
1021   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1022                            llvm::sys::fs::F_None);
1023 }
1024 
1025 /// \brief Prune the module cache of modules that haven't been accessed in
1026 /// a long time.
1027 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1028   struct stat StatBuf;
1029   llvm::SmallString<128> TimestampFile;
1030   TimestampFile = HSOpts.ModuleCachePath;
1031   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1032 
1033   // Try to stat() the timestamp file.
1034   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1035     // If the timestamp file wasn't there, create one now.
1036     if (errno == ENOENT) {
1037       writeTimestampFile(TimestampFile);
1038     }
1039     return;
1040   }
1041 
1042   // Check whether the time stamp is older than our pruning interval.
1043   // If not, do nothing.
1044   time_t TimeStampModTime = StatBuf.st_mtime;
1045   time_t CurrentTime = time(0);
1046   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1047     return;
1048 
1049   // Write a new timestamp file so that nobody else attempts to prune.
1050   // There is a benign race condition here, if two Clang instances happen to
1051   // notice at the same time that the timestamp is out-of-date.
1052   writeTimestampFile(TimestampFile);
1053 
1054   // Walk the entire module cache, looking for unused module files and module
1055   // indices.
1056   llvm::error_code EC;
1057   SmallString<128> ModuleCachePathNative;
1058   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1059   for (llvm::sys::fs::directory_iterator
1060          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1061        Dir != DirEnd && !EC; Dir.increment(EC)) {
1062     // If we don't have a directory, there's nothing to look into.
1063     if (!llvm::sys::fs::is_directory(Dir->path()))
1064       continue;
1065 
1066     // Walk all of the files within this directory.
1067     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1068          File != FileEnd && !EC; File.increment(EC)) {
1069       // We only care about module and global module index files.
1070       StringRef Extension = llvm::sys::path::extension(File->path());
1071       if (Extension != ".pcm" && Extension != ".timestamp" &&
1072           llvm::sys::path::filename(File->path()) != "modules.idx")
1073         continue;
1074 
1075       // Look at this file. If we can't stat it, there's nothing interesting
1076       // there.
1077       if (::stat(File->path().c_str(), &StatBuf))
1078         continue;
1079 
1080       // If the file has been used recently enough, leave it there.
1081       time_t FileAccessTime = StatBuf.st_atime;
1082       if (CurrentTime - FileAccessTime <=
1083               time_t(HSOpts.ModuleCachePruneAfter)) {
1084         continue;
1085       }
1086 
1087       // Remove the file.
1088       llvm::sys::fs::remove(File->path());
1089 
1090       // Remove the timestamp file.
1091       std::string TimpestampFilename = File->path() + ".timestamp";
1092       llvm::sys::fs::remove(TimpestampFilename);
1093     }
1094 
1095     // If we removed all of the files in the directory, remove the directory
1096     // itself.
1097     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1098             llvm::sys::fs::directory_iterator() && !EC)
1099       llvm::sys::fs::remove(Dir->path());
1100   }
1101 }
1102 
1103 void CompilerInstance::createModuleManager() {
1104   if (!ModuleManager) {
1105     if (!hasASTContext())
1106       createASTContext();
1107 
1108     // If we're not recursively building a module, check whether we
1109     // need to prune the module cache.
1110     if (getSourceManager().getModuleBuildStack().empty() &&
1111         getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1112         getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1113       pruneModuleCache(getHeaderSearchOpts());
1114     }
1115 
1116     HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
1117     std::string Sysroot = HSOpts.Sysroot;
1118     const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1119     ModuleManager = new ASTReader(getPreprocessor(), *Context,
1120                                   Sysroot.empty() ? "" : Sysroot.c_str(),
1121                                   PPOpts.DisablePCHValidation,
1122                                   /*AllowASTWithCompilerErrors=*/false,
1123                                   /*AllowConfigurationMismatch=*/false,
1124                                   HSOpts.ModulesValidateSystemHeaders,
1125                                   getFrontendOpts().UseGlobalModuleIndex);
1126     if (hasASTConsumer()) {
1127       ModuleManager->setDeserializationListener(
1128         getASTConsumer().GetASTDeserializationListener());
1129       getASTContext().setASTMutationListener(
1130         getASTConsumer().GetASTMutationListener());
1131     }
1132     getASTContext().setExternalSource(ModuleManager);
1133     if (hasSema())
1134       ModuleManager->InitializeSema(getSema());
1135     if (hasASTConsumer())
1136       ModuleManager->StartTranslationUnit(&getASTConsumer());
1137   }
1138 }
1139 
1140 ModuleLoadResult
1141 CompilerInstance::loadModule(SourceLocation ImportLoc,
1142                              ModuleIdPath Path,
1143                              Module::NameVisibilityKind Visibility,
1144                              bool IsInclusionDirective) {
1145   // Determine what file we're searching from.
1146   StringRef ModuleName = Path[0].first->getName();
1147   SourceLocation ModuleNameLoc = Path[0].second;
1148 
1149   // If we've already handled this import, just return the cached result.
1150   // This one-element cache is important to eliminate redundant diagnostics
1151   // when both the preprocessor and parser see the same import declaration.
1152   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1153     // Make the named module visible.
1154     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1155       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1156                                        ImportLoc, /*Complain=*/false);
1157     return LastModuleImportResult;
1158   }
1159 
1160   clang::Module *Module = 0;
1161 
1162   // If we don't already have information on this module, load the module now.
1163   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1164     = KnownModules.find(Path[0].first);
1165   if (Known != KnownModules.end()) {
1166     // Retrieve the cached top-level module.
1167     Module = Known->second;
1168   } else if (ModuleName == getLangOpts().CurrentModule) {
1169     // This is the module we're building.
1170     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1171     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1172   } else {
1173     // Search for a module with the given name.
1174     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1175     if (!Module) {
1176       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1177       << ModuleName
1178       << SourceRange(ImportLoc, ModuleNameLoc);
1179       ModuleBuildFailed = true;
1180       return ModuleLoadResult();
1181     }
1182 
1183     std::string ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1184 
1185     // If we don't already have an ASTReader, create one now.
1186     if (!ModuleManager)
1187       createModuleManager();
1188 
1189     if (TheDependencyFileGenerator)
1190       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
1191 
1192     // Try to load the module file.
1193     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1194     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1195                                    ImportLoc, ARRFlags)) {
1196     case ASTReader::Success:
1197       break;
1198 
1199     case ASTReader::OutOfDate:
1200     case ASTReader::Missing: {
1201       // The module file is missing or out-of-date. Build it.
1202       assert(Module && "missing module file");
1203       // Check whether there is a cycle in the module graph.
1204       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1205       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1206       for (; Pos != PosEnd; ++Pos) {
1207         if (Pos->first == ModuleName)
1208           break;
1209       }
1210 
1211       if (Pos != PosEnd) {
1212         SmallString<256> CyclePath;
1213         for (; Pos != PosEnd; ++Pos) {
1214           CyclePath += Pos->first;
1215           CyclePath += " -> ";
1216         }
1217         CyclePath += ModuleName;
1218 
1219         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1220           << ModuleName << CyclePath;
1221         return ModuleLoadResult();
1222       }
1223 
1224       // Check whether we have already attempted to build this module (but
1225       // failed).
1226       if (getPreprocessorOpts().FailedModules &&
1227           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1228         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1229           << ModuleName
1230           << SourceRange(ImportLoc, ModuleNameLoc);
1231         ModuleBuildFailed = true;
1232         return ModuleLoadResult();
1233       }
1234 
1235       // Try to compile the module.
1236       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1237 
1238       // Try to read the module file, now that we've compiled it.
1239       ASTReader::ASTReadResult ReadResult
1240         = ModuleManager->ReadAST(ModuleFileName,
1241                                  serialization::MK_Module, ImportLoc,
1242                                  ASTReader::ARR_Missing);
1243       if (ReadResult != ASTReader::Success) {
1244         if (ReadResult == ASTReader::Missing) {
1245           getDiagnostics().Report(ModuleNameLoc,
1246                                   Module? diag::err_module_not_built
1247                                         : diag::err_module_not_found)
1248             << ModuleName
1249             << SourceRange(ImportLoc, ModuleNameLoc);
1250         }
1251 
1252         if (getPreprocessorOpts().FailedModules)
1253           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1254         KnownModules[Path[0].first] = 0;
1255         ModuleBuildFailed = true;
1256         return ModuleLoadResult();
1257       }
1258 
1259       // Okay, we've rebuilt and now loaded the module.
1260       break;
1261     }
1262 
1263     case ASTReader::VersionMismatch:
1264     case ASTReader::ConfigurationMismatch:
1265     case ASTReader::HadErrors:
1266       ModuleLoader::HadFatalFailure = true;
1267       // FIXME: The ASTReader will already have complained, but can we showhorn
1268       // that diagnostic information into a more useful form?
1269       KnownModules[Path[0].first] = 0;
1270       return ModuleLoadResult();
1271 
1272     case ASTReader::Failure:
1273       ModuleLoader::HadFatalFailure = true;
1274       // Already complained, but note now that we failed.
1275       KnownModules[Path[0].first] = 0;
1276       ModuleBuildFailed = true;
1277       return ModuleLoadResult();
1278     }
1279 
1280     // Cache the result of this top-level module lookup for later.
1281     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1282   }
1283 
1284   // If we never found the module, fail.
1285   if (!Module)
1286     return ModuleLoadResult();
1287 
1288   // Verify that the rest of the module path actually corresponds to
1289   // a submodule.
1290   if (Path.size() > 1) {
1291     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1292       StringRef Name = Path[I].first->getName();
1293       clang::Module *Sub = Module->findSubmodule(Name);
1294 
1295       if (!Sub) {
1296         // Attempt to perform typo correction to find a module name that works.
1297         SmallVector<StringRef, 2> Best;
1298         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1299 
1300         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1301                                             JEnd = Module->submodule_end();
1302              J != JEnd; ++J) {
1303           unsigned ED = Name.edit_distance((*J)->Name,
1304                                            /*AllowReplacements=*/true,
1305                                            BestEditDistance);
1306           if (ED <= BestEditDistance) {
1307             if (ED < BestEditDistance) {
1308               Best.clear();
1309               BestEditDistance = ED;
1310             }
1311 
1312             Best.push_back((*J)->Name);
1313           }
1314         }
1315 
1316         // If there was a clear winner, user it.
1317         if (Best.size() == 1) {
1318           getDiagnostics().Report(Path[I].second,
1319                                   diag::err_no_submodule_suggest)
1320             << Path[I].first << Module->getFullModuleName() << Best[0]
1321             << SourceRange(Path[0].second, Path[I-1].second)
1322             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1323                                             Best[0]);
1324 
1325           Sub = Module->findSubmodule(Best[0]);
1326         }
1327       }
1328 
1329       if (!Sub) {
1330         // No submodule by this name. Complain, and don't look for further
1331         // submodules.
1332         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1333           << Path[I].first << Module->getFullModuleName()
1334           << SourceRange(Path[0].second, Path[I-1].second);
1335         break;
1336       }
1337 
1338       Module = Sub;
1339     }
1340   }
1341 
1342   // Make the named module visible, if it's not already part of the module
1343   // we are parsing.
1344   if (ModuleName != getLangOpts().CurrentModule) {
1345     if (!Module->IsFromModuleFile) {
1346       // We have an umbrella header or directory that doesn't actually include
1347       // all of the headers within the directory it covers. Complain about
1348       // this missing submodule and recover by forgetting that we ever saw
1349       // this submodule.
1350       // FIXME: Should we detect this at module load time? It seems fairly
1351       // expensive (and rare).
1352       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1353         << Module->getFullModuleName()
1354         << SourceRange(Path.front().second, Path.back().second);
1355 
1356       return ModuleLoadResult(0, true);
1357     }
1358 
1359     // Check whether this module is available.
1360     clang::Module::Requirement Requirement;
1361     clang::Module::HeaderDirective MissingHeader;
1362     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
1363                              MissingHeader)) {
1364       if (MissingHeader.FileNameLoc.isValid()) {
1365         getDiagnostics().Report(MissingHeader.FileNameLoc,
1366                                 diag::err_module_header_missing)
1367           << MissingHeader.IsUmbrella << MissingHeader.FileName;
1368       } else {
1369         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1370           << Module->getFullModuleName()
1371           << Requirement.second << Requirement.first
1372           << SourceRange(Path.front().second, Path.back().second);
1373       }
1374       LastModuleImportLoc = ImportLoc;
1375       LastModuleImportResult = ModuleLoadResult();
1376       return ModuleLoadResult();
1377     }
1378 
1379     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1380                                      /*Complain=*/true);
1381   }
1382 
1383   // Check for any configuration macros that have changed.
1384   clang::Module *TopModule = Module->getTopLevelModule();
1385   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1386     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1387                      Module, ImportLoc);
1388   }
1389 
1390   // If this module import was due to an inclusion directive, create an
1391   // implicit import declaration to capture it in the AST.
1392   if (IsInclusionDirective && hasASTContext()) {
1393     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1394     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1395                                                      ImportLoc, Module,
1396                                                      Path.back().second);
1397     TU->addDecl(ImportD);
1398     if (Consumer)
1399       Consumer->HandleImplicitImportDecl(ImportD);
1400   }
1401 
1402   LastModuleImportLoc = ImportLoc;
1403   LastModuleImportResult = ModuleLoadResult(Module, false);
1404   return LastModuleImportResult;
1405 }
1406 
1407 void CompilerInstance::makeModuleVisible(Module *Mod,
1408                                          Module::NameVisibilityKind Visibility,
1409                                          SourceLocation ImportLoc,
1410                                          bool Complain){
1411   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1412 }
1413 
1414 GlobalModuleIndex *CompilerInstance::loadGlobalModuleIndex(
1415     SourceLocation TriggerLoc) {
1416   if (!ModuleManager)
1417     createModuleManager();
1418   // Can't do anything if we don't have the module manager.
1419   if (!ModuleManager)
1420     return 0;
1421   // Get an existing global index.  This loads it if not already
1422   // loaded.
1423   ModuleManager->loadGlobalIndex();
1424   GlobalModuleIndex *GlobalIndex = ModuleManager->getGlobalIndex();
1425   // If the global index doesn't exist, create it.
1426   if (!GlobalIndex && shouldBuildGlobalModuleIndex() && hasFileManager() &&
1427       hasPreprocessor()) {
1428     llvm::sys::fs::create_directories(
1429       getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
1430     GlobalModuleIndex::writeIndex(
1431       getFileManager(),
1432       getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
1433     ModuleManager->resetForReload();
1434     ModuleManager->loadGlobalIndex();
1435     GlobalIndex = ModuleManager->getGlobalIndex();
1436   }
1437   // For finding modules needing to be imported for fixit messages,
1438   // we need to make the global index cover all modules, so we do that here.
1439   if (!HaveFullGlobalModuleIndex && GlobalIndex && !buildingModule()) {
1440     ModuleMap &MMap = getPreprocessor().getHeaderSearchInfo().getModuleMap();
1441     bool RecreateIndex = false;
1442     for (ModuleMap::module_iterator I = MMap.module_begin(),
1443         E = MMap.module_end(); I != E; ++I) {
1444       Module *TheModule = I->second;
1445       const FileEntry *Entry = TheModule->getASTFile();
1446       if (!Entry) {
1447         SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
1448         Path.push_back(std::make_pair(
1449 				  getPreprocessor().getIdentifierInfo(TheModule->Name), TriggerLoc));
1450         std::reverse(Path.begin(), Path.end());
1451 		    // Load a module as hidden.  This also adds it to the global index.
1452         loadModule(TheModule->DefinitionLoc, Path,
1453                                              Module::Hidden, false);
1454         RecreateIndex = true;
1455       }
1456     }
1457     if (RecreateIndex) {
1458       GlobalModuleIndex::writeIndex(
1459         getFileManager(),
1460         getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
1461       ModuleManager->resetForReload();
1462       ModuleManager->loadGlobalIndex();
1463       GlobalIndex = ModuleManager->getGlobalIndex();
1464     }
1465     HaveFullGlobalModuleIndex = true;
1466   }
1467   return GlobalIndex;
1468 }
1469 
1470 // Check global module index for missing imports.
1471 bool
1472 CompilerInstance::lookupMissingImports(StringRef Name,
1473                                        SourceLocation TriggerLoc) {
1474   // Look for the symbol in non-imported modules, but only if an error
1475   // actually occurred.
1476   if (!buildingModule()) {
1477     // Load global module index, or retrieve a previously loaded one.
1478     GlobalModuleIndex *GlobalIndex = loadGlobalModuleIndex(
1479       TriggerLoc);
1480 
1481     // Only if we have a global index.
1482     if (GlobalIndex) {
1483       GlobalModuleIndex::HitSet FoundModules;
1484 
1485       // Find the modules that reference the identifier.
1486       // Note that this only finds top-level modules.
1487       // We'll let diagnoseTypo find the actual declaration module.
1488       if (GlobalIndex->lookupIdentifier(Name, FoundModules))
1489         return true;
1490     }
1491   }
1492 
1493   return false;
1494 }
1495