xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision 4382fe74bb5ddbca63caa33ba004dad98072094c)
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   std::unique_ptr<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.release(), DiagOpts);
162 
163   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
164                                                 SerializedConsumer));
165 }
166 
167 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
168                                          bool ShouldOwnClient) {
169   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
170                                   ShouldOwnClient, &getCodeGenOpts());
171 }
172 
173 IntrusiveRefCntPtr<DiagnosticsEngine>
174 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
175                                     DiagnosticConsumer *Client,
176                                     bool ShouldOwnClient,
177                                     const CodeGenOptions *CodeGenOpts) {
178   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
179   IntrusiveRefCntPtr<DiagnosticsEngine>
180       Diags(new DiagnosticsEngine(DiagID, Opts));
181 
182   // Create the diagnostic client for reporting errors or for
183   // implementing -verify.
184   if (Client) {
185     Diags->setClient(Client, ShouldOwnClient);
186   } else
187     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
188 
189   // Chain in -verify checker, if requested.
190   if (Opts->VerifyDiagnostics)
191     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
192 
193   // Chain in -diagnostic-log-file dumper, if requested.
194   if (!Opts->DiagnosticLogFile.empty())
195     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
196 
197   if (!Opts->DiagnosticSerializationFile.empty())
198     SetupSerializedDiagnostics(Opts, *Diags,
199                                Opts->DiagnosticSerializationFile);
200 
201   // Configure our handling of diagnostics.
202   ProcessWarningOptions(*Diags, *Opts);
203 
204   return Diags;
205 }
206 
207 // File Manager
208 
209 void CompilerInstance::createFileManager() {
210   if (!hasVirtualFileSystem()) {
211     // TODO: choose the virtual file system based on the CompilerInvocation.
212     setVirtualFileSystem(vfs::getRealFileSystem());
213   }
214   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
215 }
216 
217 // Source Manager
218 
219 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
220   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
221 }
222 
223 // Preprocessor
224 
225 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
226   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
227 
228   // Create a PTH manager if we are using some form of a token cache.
229   PTHManager *PTHMgr = 0;
230   if (!PPOpts.TokenCache.empty())
231     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
232 
233   // Create the Preprocessor.
234   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
235                                               getSourceManager(),
236                                               getDiagnostics(),
237                                               getLangOpts(),
238                                               &getTarget());
239   PP = new Preprocessor(&getPreprocessorOpts(),
240                         getDiagnostics(), getLangOpts(), &getTarget(),
241                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
242                         /*OwnsHeaderSearch=*/true,
243                         /*DelayInitialization=*/false,
244                         /*IncrProcessing=*/false,
245                         TUKind);
246 
247   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
248   // That argument is used as the IdentifierInfoLookup argument to
249   // IdentifierTable's ctor.
250   if (PTHMgr) {
251     PTHMgr->setPreprocessor(&*PP);
252     PP->setPTHManager(PTHMgr);
253   }
254 
255   if (PPOpts.DetailedRecord)
256     PP->createPreprocessingRecord();
257 
258   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
259 
260   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
261 
262   // Set up the module path, including the hash for the
263   // module-creation options.
264   SmallString<256> SpecificModuleCache(
265                            getHeaderSearchOpts().ModuleCachePath);
266   if (!getHeaderSearchOpts().DisableModuleHash)
267     llvm::sys::path::append(SpecificModuleCache,
268                             getInvocation().getModuleHash());
269   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
270 
271   // Handle generating dependencies, if requested.
272   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
273   if (!DepOpts.OutputFile.empty())
274     TheDependencyFileGenerator.reset(
275         DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
276   if (!DepOpts.DOTOutputFile.empty())
277     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
278                              getHeaderSearchOpts().Sysroot);
279 
280 
281   // Handle generating header include information, if requested.
282   if (DepOpts.ShowHeaderIncludes)
283     AttachHeaderIncludeGen(*PP);
284   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
285     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
286     if (OutputPath == "-")
287       OutputPath = "";
288     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
289                            /*ShowDepth=*/false);
290   }
291 
292   if (DepOpts.PrintShowIncludes) {
293     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
294                            /*ShowDepth=*/true, /*MSStyle=*/true);
295   }
296 }
297 
298 // ASTContext
299 
300 void CompilerInstance::createASTContext() {
301   Preprocessor &PP = getPreprocessor();
302   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
303                            &getTarget(), PP.getIdentifierTable(),
304                            PP.getSelectorTable(), PP.getBuiltinInfo(),
305                            /*size_reserve=*/ 0);
306 }
307 
308 // ExternalASTSource
309 
310 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
311                                                   bool DisablePCHValidation,
312                                                 bool AllowPCHWithCompilerErrors,
313                                                  void *DeserializationListener){
314   IntrusiveRefCntPtr<ExternalASTSource> Source;
315   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
316   Source = createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
317                                           DisablePCHValidation,
318                                           AllowPCHWithCompilerErrors,
319                                           getPreprocessor(), getASTContext(),
320                                           DeserializationListener,
321                                           Preamble,
322                                        getFrontendOpts().UseGlobalModuleIndex);
323   ModuleManager = static_cast<ASTReader*>(Source.getPtr());
324   getASTContext().setExternalSource(Source);
325 }
326 
327 ExternalASTSource *
328 CompilerInstance::createPCHExternalASTSource(StringRef Path,
329                                              const std::string &Sysroot,
330                                              bool DisablePCHValidation,
331                                              bool AllowPCHWithCompilerErrors,
332                                              Preprocessor &PP,
333                                              ASTContext &Context,
334                                              void *DeserializationListener,
335                                              bool Preamble,
336                                              bool UseGlobalModuleIndex) {
337   HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
338 
339   std::unique_ptr<ASTReader> Reader;
340   Reader.reset(new ASTReader(PP, Context,
341                              Sysroot.empty() ? "" : Sysroot.c_str(),
342                              DisablePCHValidation,
343                              AllowPCHWithCompilerErrors,
344                              /*AllowConfigurationMismatch*/false,
345                              HSOpts.ModulesValidateSystemHeaders,
346                              UseGlobalModuleIndex));
347 
348   Reader->setDeserializationListener(
349             static_cast<ASTDeserializationListener *>(DeserializationListener));
350   switch (Reader->ReadAST(Path,
351                           Preamble ? serialization::MK_Preamble
352                                    : serialization::MK_PCH,
353                           SourceLocation(),
354                           ASTReader::ARR_None)) {
355   case ASTReader::Success:
356     // Set the predefines buffer as suggested by the PCH reader. Typically, the
357     // predefines buffer will be empty.
358     PP.setPredefines(Reader->getSuggestedPredefines());
359     return Reader.release();
360 
361   case ASTReader::Failure:
362     // Unrecoverable failure: don't even try to process the input file.
363     break;
364 
365   case ASTReader::Missing:
366   case ASTReader::OutOfDate:
367   case ASTReader::VersionMismatch:
368   case ASTReader::ConfigurationMismatch:
369   case ASTReader::HadErrors:
370     // No suitable PCH file could be found. Return an error.
371     break;
372   }
373 
374   return 0;
375 }
376 
377 // Code Completion
378 
379 static bool EnableCodeCompletion(Preprocessor &PP,
380                                  const std::string &Filename,
381                                  unsigned Line,
382                                  unsigned Column) {
383   // Tell the source manager to chop off the given file at a specific
384   // line and column.
385   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
386   if (!Entry) {
387     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
388       << Filename;
389     return true;
390   }
391 
392   // Truncate the named file at the given line/column.
393   PP.SetCodeCompletionPoint(Entry, Line, Column);
394   return false;
395 }
396 
397 void CompilerInstance::createCodeCompletionConsumer() {
398   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
399   if (!CompletionConsumer) {
400     setCodeCompletionConsumer(
401       createCodeCompletionConsumer(getPreprocessor(),
402                                    Loc.FileName, Loc.Line, Loc.Column,
403                                    getFrontendOpts().CodeCompleteOpts,
404                                    llvm::outs()));
405     if (!CompletionConsumer)
406       return;
407   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
408                                   Loc.Line, Loc.Column)) {
409     setCodeCompletionConsumer(0);
410     return;
411   }
412 
413   if (CompletionConsumer->isOutputBinary() &&
414       llvm::sys::ChangeStdoutToBinary()) {
415     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
416     setCodeCompletionConsumer(0);
417   }
418 }
419 
420 void CompilerInstance::createFrontendTimer() {
421   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
422 }
423 
424 CodeCompleteConsumer *
425 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
426                                                const std::string &Filename,
427                                                unsigned Line,
428                                                unsigned Column,
429                                                const CodeCompleteOptions &Opts,
430                                                raw_ostream &OS) {
431   if (EnableCodeCompletion(PP, Filename, Line, Column))
432     return 0;
433 
434   // Set up the creation routine for code-completion.
435   return new PrintingCodeCompleteConsumer(Opts, OS);
436 }
437 
438 void CompilerInstance::createSema(TranslationUnitKind TUKind,
439                                   CodeCompleteConsumer *CompletionConsumer) {
440   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
441                          TUKind, CompletionConsumer));
442 }
443 
444 // Output Files
445 
446 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
447   assert(OutFile.OS && "Attempt to add empty stream to output list!");
448   OutputFiles.push_back(OutFile);
449 }
450 
451 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
452   for (std::list<OutputFile>::iterator
453          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
454     delete it->OS;
455     if (!it->TempFilename.empty()) {
456       if (EraseFiles) {
457         llvm::sys::fs::remove(it->TempFilename);
458       } else {
459         SmallString<128> NewOutFile(it->Filename);
460 
461         // If '-working-directory' was passed, the output filename should be
462         // relative to that.
463         FileMgr->FixupRelativePath(NewOutFile);
464         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
465                                                         NewOutFile.str())) {
466           getDiagnostics().Report(diag::err_unable_to_rename_temp)
467             << it->TempFilename << it->Filename << ec.message();
468 
469           llvm::sys::fs::remove(it->TempFilename);
470         }
471       }
472     } else if (!it->Filename.empty() && EraseFiles)
473       llvm::sys::fs::remove(it->Filename);
474 
475   }
476   OutputFiles.clear();
477 }
478 
479 llvm::raw_fd_ostream *
480 CompilerInstance::createDefaultOutputFile(bool Binary,
481                                           StringRef InFile,
482                                           StringRef Extension) {
483   return createOutputFile(getFrontendOpts().OutputFile, Binary,
484                           /*RemoveFileOnSignal=*/true, InFile, Extension,
485                           /*UseTemporary=*/true);
486 }
487 
488 llvm::raw_fd_ostream *
489 CompilerInstance::createOutputFile(StringRef OutputPath,
490                                    bool Binary, bool RemoveFileOnSignal,
491                                    StringRef InFile,
492                                    StringRef Extension,
493                                    bool UseTemporary,
494                                    bool CreateMissingDirectories) {
495   std::string Error, OutputPathName, TempPathName;
496   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
497                                               RemoveFileOnSignal,
498                                               InFile, Extension,
499                                               UseTemporary,
500                                               CreateMissingDirectories,
501                                               &OutputPathName,
502                                               &TempPathName);
503   if (!OS) {
504     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
505       << OutputPath << Error;
506     return 0;
507   }
508 
509   // Add the output file -- but don't try to remove "-", since this means we are
510   // using stdin.
511   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
512                 TempPathName, OS));
513 
514   return OS;
515 }
516 
517 llvm::raw_fd_ostream *
518 CompilerInstance::createOutputFile(StringRef OutputPath,
519                                    std::string &Error,
520                                    bool Binary,
521                                    bool RemoveFileOnSignal,
522                                    StringRef InFile,
523                                    StringRef Extension,
524                                    bool UseTemporary,
525                                    bool CreateMissingDirectories,
526                                    std::string *ResultPathName,
527                                    std::string *TempPathName) {
528   assert((!CreateMissingDirectories || UseTemporary) &&
529          "CreateMissingDirectories is only allowed when using temporary files");
530 
531   std::string OutFile, TempFile;
532   if (!OutputPath.empty()) {
533     OutFile = OutputPath;
534   } else if (InFile == "-") {
535     OutFile = "-";
536   } else if (!Extension.empty()) {
537     SmallString<128> Path(InFile);
538     llvm::sys::path::replace_extension(Path, Extension);
539     OutFile = Path.str();
540   } else {
541     OutFile = "-";
542   }
543 
544   std::unique_ptr<llvm::raw_fd_ostream> OS;
545   std::string OSFile;
546 
547   if (UseTemporary) {
548     if (OutFile == "-")
549       UseTemporary = false;
550     else {
551       llvm::sys::fs::file_status Status;
552       llvm::sys::fs::status(OutputPath, Status);
553       if (llvm::sys::fs::exists(Status)) {
554         // Fail early if we can't write to the final destination.
555         if (!llvm::sys::fs::can_write(OutputPath))
556           return 0;
557 
558         // Don't use a temporary if the output is a special file. This handles
559         // things like '-o /dev/null'
560         if (!llvm::sys::fs::is_regular_file(Status))
561           UseTemporary = false;
562       }
563     }
564   }
565 
566   if (UseTemporary) {
567     // Create a temporary file.
568     SmallString<128> TempPath;
569     TempPath = OutFile;
570     TempPath += "-%%%%%%%%";
571     int fd;
572     llvm::error_code EC =
573         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
574 
575     if (CreateMissingDirectories &&
576         EC == llvm::errc::no_such_file_or_directory) {
577       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
578       EC = llvm::sys::fs::create_directories(Parent);
579       if (!EC) {
580         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
581       }
582     }
583 
584     if (!EC) {
585       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
586       OSFile = TempFile = TempPath.str();
587     }
588     // If we failed to create the temporary, fallback to writing to the file
589     // directly. This handles the corner case where we cannot write to the
590     // directory, but can write to the file.
591   }
592 
593   if (!OS) {
594     OSFile = OutFile;
595     OS.reset(new llvm::raw_fd_ostream(
596         OSFile.c_str(), Error,
597         (Binary ? llvm::sys::fs::F_None : llvm::sys::fs::F_Text)));
598     if (!Error.empty())
599       return 0;
600   }
601 
602   // Make sure the out stream file gets removed if we crash.
603   if (RemoveFileOnSignal)
604     llvm::sys::RemoveFileOnSignal(OSFile);
605 
606   if (ResultPathName)
607     *ResultPathName = OutFile;
608   if (TempPathName)
609     *TempPathName = TempFile;
610 
611   return OS.release();
612 }
613 
614 // Initialization Utilities
615 
616 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
617   return InitializeSourceManager(Input, getDiagnostics(),
618                                  getFileManager(), getSourceManager(),
619                                  getFrontendOpts());
620 }
621 
622 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
623                                                DiagnosticsEngine &Diags,
624                                                FileManager &FileMgr,
625                                                SourceManager &SourceMgr,
626                                                const FrontendOptions &Opts) {
627   SrcMgr::CharacteristicKind
628     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
629 
630   if (Input.isBuffer()) {
631     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
632     assert(!SourceMgr.getMainFileID().isInvalid() &&
633            "Couldn't establish MainFileID!");
634     return true;
635   }
636 
637   StringRef InputFile = Input.getFile();
638 
639   // Figure out where to get and map in the main file.
640   if (InputFile != "-") {
641     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
642     if (!File) {
643       Diags.Report(diag::err_fe_error_reading) << InputFile;
644       return false;
645     }
646 
647     // The natural SourceManager infrastructure can't currently handle named
648     // pipes, but we would at least like to accept them for the main
649     // file. Detect them here, read them with the volatile flag so FileMgr will
650     // pick up the correct size, and simply override their contents as we do for
651     // STDIN.
652     if (File->isNamedPipe()) {
653       std::string ErrorStr;
654       if (llvm::MemoryBuffer *MB =
655               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
656         // Create a new virtual file that will have the correct size.
657         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
658         SourceMgr.overrideFileContents(File, MB);
659       } else {
660         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
661         return false;
662       }
663     }
664 
665     SourceMgr.createMainFileID(File, Kind);
666   } else {
667     std::unique_ptr<llvm::MemoryBuffer> SB;
668     if (llvm::error_code ec = llvm::MemoryBuffer::getSTDIN(SB)) {
669       Diags.Report(diag::err_fe_error_reading_stdin) << ec.message();
670       return false;
671     }
672     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
673                                                    SB->getBufferSize(), 0);
674     SourceMgr.createMainFileID(File, Kind);
675     SourceMgr.overrideFileContents(File, SB.release());
676   }
677 
678   assert(!SourceMgr.getMainFileID().isInvalid() &&
679          "Couldn't establish MainFileID!");
680   return true;
681 }
682 
683 // High-Level Operations
684 
685 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
686   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
687   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
688   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
689 
690   // FIXME: Take this as an argument, once all the APIs we used have moved to
691   // taking it as an input instead of hard-coding llvm::errs.
692   raw_ostream &OS = llvm::errs();
693 
694   // Create the target instance.
695   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
696   if (!hasTarget())
697     return false;
698 
699   // Inform the target of the language options.
700   //
701   // FIXME: We shouldn't need to do this, the target should be immutable once
702   // created. This complexity should be lifted elsewhere.
703   getTarget().setForcedLangOptions(getLangOpts());
704 
705   // rewriter project will change target built-in bool type from its default.
706   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
707     getTarget().noSignedCharForObjCBool();
708 
709   // Validate/process some options.
710   if (getHeaderSearchOpts().Verbose)
711     OS << "clang -cc1 version " CLANG_VERSION_STRING
712        << " based upon " << PACKAGE_STRING
713        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
714 
715   if (getFrontendOpts().ShowTimers)
716     createFrontendTimer();
717 
718   if (getFrontendOpts().ShowStats)
719     llvm::EnableStatistics();
720 
721   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
722     // Reset the ID tables if we are reusing the SourceManager.
723     if (hasSourceManager())
724       getSourceManager().clearIDTables();
725 
726     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
727       Act.Execute();
728       Act.EndSourceFile();
729     }
730   }
731 
732   // Notify the diagnostic client that all files were processed.
733   getDiagnostics().getClient()->finish();
734 
735   if (getDiagnosticOpts().ShowCarets) {
736     // We can have multiple diagnostics sharing one diagnostic client.
737     // Get the total number of warnings/errors from the client.
738     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
739     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
740 
741     if (NumWarnings)
742       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
743     if (NumWarnings && NumErrors)
744       OS << " and ";
745     if (NumErrors)
746       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
747     if (NumWarnings || NumErrors)
748       OS << " generated.\n";
749   }
750 
751   if (getFrontendOpts().ShowStats && hasFileManager()) {
752     getFileManager().PrintStats();
753     OS << "\n";
754   }
755 
756   return !getDiagnostics().getClient()->getNumErrors();
757 }
758 
759 /// \brief Determine the appropriate source input kind based on language
760 /// options.
761 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
762   if (LangOpts.OpenCL)
763     return IK_OpenCL;
764   if (LangOpts.CUDA)
765     return IK_CUDA;
766   if (LangOpts.ObjC1)
767     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
768   return LangOpts.CPlusPlus? IK_CXX : IK_C;
769 }
770 
771 /// \brief Compile a module file for the given module, using the options
772 /// provided by the importing compiler instance.
773 static void compileModuleImpl(CompilerInstance &ImportingInstance,
774                           SourceLocation ImportLoc,
775                           Module *Module,
776                           StringRef ModuleFileName) {
777   ModuleMap &ModMap
778     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
779 
780   // Construct a compiler invocation for creating this module.
781   IntrusiveRefCntPtr<CompilerInvocation> Invocation
782     (new CompilerInvocation(ImportingInstance.getInvocation()));
783 
784   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
785 
786   // For any options that aren't intended to affect how a module is built,
787   // reset them to their default values.
788   Invocation->getLangOpts()->resetNonModularOptions();
789   PPOpts.resetNonModularOptions();
790 
791   // Remove any macro definitions that are explicitly ignored by the module.
792   // They aren't supposed to affect how the module is built anyway.
793   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
794   PPOpts.Macros.erase(
795       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
796                      [&HSOpts](const std::pair<std::string, bool> &def) {
797         StringRef MacroDef = def.first;
798         return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
799       }),
800       PPOpts.Macros.end());
801 
802   // Note the name of the module we're building.
803   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
804 
805   // Make sure that the failed-module structure has been allocated in
806   // the importing instance, and propagate the pointer to the newly-created
807   // instance.
808   PreprocessorOptions &ImportingPPOpts
809     = ImportingInstance.getInvocation().getPreprocessorOpts();
810   if (!ImportingPPOpts.FailedModules)
811     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
812   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
813 
814   // If there is a module map file, build the module using the module map.
815   // Set up the inputs/outputs so that we build the module from its umbrella
816   // header.
817   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
818   FrontendOpts.OutputFile = ModuleFileName.str();
819   FrontendOpts.DisableFree = false;
820   FrontendOpts.GenerateGlobalModuleIndex = false;
821   FrontendOpts.Inputs.clear();
822   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
823 
824   // Don't free the remapped file buffers; they are owned by our caller.
825   PPOpts.RetainRemappedFileBuffers = true;
826 
827   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
828   assert(ImportingInstance.getInvocation().getModuleHash() ==
829          Invocation->getModuleHash() && "Module hash mismatch!");
830 
831   // Construct a compiler instance that will be used to actually create the
832   // module.
833   CompilerInstance Instance;
834   Instance.setInvocation(&*Invocation);
835 
836   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
837                                    ImportingInstance.getDiagnosticClient()),
838                              /*ShouldOwnClient=*/true);
839 
840   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
841 
842   // Note that this module is part of the module build stack, so that we
843   // can detect cycles in the module graph.
844   Instance.setFileManager(&ImportingInstance.getFileManager());
845   Instance.createSourceManager(Instance.getFileManager());
846   SourceManager &SourceMgr = Instance.getSourceManager();
847   SourceMgr.setModuleBuildStack(
848     ImportingInstance.getSourceManager().getModuleBuildStack());
849   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
850     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
851 
852   // Get or create the module map that we'll use to build this module.
853   std::string InferredModuleMapContent;
854   if (const FileEntry *ModuleMapFile =
855           ModMap.getContainingModuleMapFile(Module)) {
856     // Use the module map where this module resides.
857     FrontendOpts.Inputs.push_back(
858         FrontendInputFile(ModuleMapFile->getName(), IK));
859   } else {
860     llvm::raw_string_ostream OS(InferredModuleMapContent);
861     Module->print(OS);
862     OS.flush();
863     FrontendOpts.Inputs.push_back(
864         FrontendInputFile("__inferred_module.map", IK));
865 
866     const llvm::MemoryBuffer *ModuleMapBuffer =
867         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
868     ModuleMapFile = Instance.getFileManager().getVirtualFile(
869         "__inferred_module.map", InferredModuleMapContent.size(), 0);
870     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
871   }
872 
873   // Construct a module-generating action.
874   GenerateModuleAction CreateModuleAction(Module->IsSystem);
875 
876   // Execute the action to actually build the module in-place. Use a separate
877   // thread so that we get a stack large enough.
878   const unsigned ThreadStackSize = 8 << 20;
879   llvm::CrashRecoveryContext CRC;
880   CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
881                         ThreadStackSize);
882 
883   // Delete the temporary module map file.
884   // FIXME: Even though we're executing under crash protection, it would still
885   // be nice to do this with RemoveFileOnSignal when we can. However, that
886   // doesn't make sense for all clients, so clean this up manually.
887   Instance.clearOutputFiles(/*EraseFiles=*/true);
888 
889   // We've rebuilt a module. If we're allowed to generate or update the global
890   // module index, record that fact in the importing compiler instance.
891   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
892     ImportingInstance.setBuildGlobalModuleIndex(true);
893   }
894 }
895 
896 static void compileModule(CompilerInstance &ImportingInstance,
897                           SourceLocation ImportLoc,
898                           Module *Module,
899                           StringRef ModuleFileName) {
900   // FIXME: have LockFileManager return an error_code so that we can
901   // avoid the mkdir when the directory already exists.
902   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
903   llvm::sys::fs::create_directories(Dir);
904 
905   while (1) {
906     llvm::LockFileManager Locked(ModuleFileName);
907     switch (Locked) {
908     case llvm::LockFileManager::LFS_Error:
909       return;
910 
911     case llvm::LockFileManager::LFS_Owned:
912       // We're responsible for building the module ourselves. Do so below.
913       break;
914 
915     case llvm::LockFileManager::LFS_Shared:
916       // Someone else is responsible for building the module. Wait for them to
917       // finish.
918       if (Locked.waitForUnlock() == llvm::LockFileManager::Res_OwnerDied)
919         continue; // try again to get the lock.
920       return;
921     }
922 
923     return compileModuleImpl(ImportingInstance, ImportLoc, Module,
924                              ModuleFileName);
925   }
926 }
927 
928 /// \brief Diagnose differences between the current definition of the given
929 /// configuration macro and the definition provided on the command line.
930 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
931                              Module *Mod, SourceLocation ImportLoc) {
932   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
933   SourceManager &SourceMgr = PP.getSourceManager();
934 
935   // If this identifier has never had a macro definition, then it could
936   // not have changed.
937   if (!Id->hadMacroDefinition())
938     return;
939 
940   // If this identifier does not currently have a macro definition,
941   // check whether it had one on the command line.
942   if (!Id->hasMacroDefinition()) {
943     MacroDirective::DefInfo LatestDef =
944         PP.getMacroDirectiveHistory(Id)->getDefinition();
945     for (MacroDirective::DefInfo Def = LatestDef; Def;
946            Def = Def.getPreviousDefinition()) {
947       FileID FID = SourceMgr.getFileID(Def.getLocation());
948       if (FID.isInvalid())
949         continue;
950 
951       // We only care about the predefines buffer.
952       if (FID != PP.getPredefinesFileID())
953         continue;
954 
955       // This macro was defined on the command line, then #undef'd later.
956       // Complain.
957       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
958         << true << ConfigMacro << Mod->getFullModuleName();
959       if (LatestDef.isUndefined())
960         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
961           << true;
962       return;
963     }
964 
965     // Okay: no definition in the predefines buffer.
966     return;
967   }
968 
969   // This identifier has a macro definition. Check whether we had a definition
970   // on the command line.
971   MacroDirective::DefInfo LatestDef =
972       PP.getMacroDirectiveHistory(Id)->getDefinition();
973   MacroDirective::DefInfo PredefinedDef;
974   for (MacroDirective::DefInfo Def = LatestDef; Def;
975          Def = Def.getPreviousDefinition()) {
976     FileID FID = SourceMgr.getFileID(Def.getLocation());
977     if (FID.isInvalid())
978       continue;
979 
980     // We only care about the predefines buffer.
981     if (FID != PP.getPredefinesFileID())
982       continue;
983 
984     PredefinedDef = Def;
985     break;
986   }
987 
988   // If there was no definition for this macro in the predefines buffer,
989   // complain.
990   if (!PredefinedDef ||
991       (!PredefinedDef.getLocation().isValid() &&
992        PredefinedDef.getUndefLocation().isValid())) {
993     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
994       << false << ConfigMacro << Mod->getFullModuleName();
995     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
996       << false;
997     return;
998   }
999 
1000   // If the current macro definition is the same as the predefined macro
1001   // definition, it's okay.
1002   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
1003       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1004                                               /*Syntactically=*/true))
1005     return;
1006 
1007   // The macro definitions differ.
1008   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1009     << false << ConfigMacro << Mod->getFullModuleName();
1010   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1011     << false;
1012 }
1013 
1014 /// \brief Write a new timestamp file with the given path.
1015 static void writeTimestampFile(StringRef TimestampFile) {
1016   std::string ErrorInfo;
1017   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1018                            llvm::sys::fs::F_None);
1019 }
1020 
1021 /// \brief Prune the module cache of modules that haven't been accessed in
1022 /// a long time.
1023 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1024   struct stat StatBuf;
1025   llvm::SmallString<128> TimestampFile;
1026   TimestampFile = HSOpts.ModuleCachePath;
1027   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1028 
1029   // Try to stat() the timestamp file.
1030   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1031     // If the timestamp file wasn't there, create one now.
1032     if (errno == ENOENT) {
1033       writeTimestampFile(TimestampFile);
1034     }
1035     return;
1036   }
1037 
1038   // Check whether the time stamp is older than our pruning interval.
1039   // If not, do nothing.
1040   time_t TimeStampModTime = StatBuf.st_mtime;
1041   time_t CurrentTime = time(0);
1042   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1043     return;
1044 
1045   // Write a new timestamp file so that nobody else attempts to prune.
1046   // There is a benign race condition here, if two Clang instances happen to
1047   // notice at the same time that the timestamp is out-of-date.
1048   writeTimestampFile(TimestampFile);
1049 
1050   // Walk the entire module cache, looking for unused module files and module
1051   // indices.
1052   llvm::error_code EC;
1053   SmallString<128> ModuleCachePathNative;
1054   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1055   for (llvm::sys::fs::directory_iterator
1056          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1057        Dir != DirEnd && !EC; Dir.increment(EC)) {
1058     // If we don't have a directory, there's nothing to look into.
1059     if (!llvm::sys::fs::is_directory(Dir->path()))
1060       continue;
1061 
1062     // Walk all of the files within this directory.
1063     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1064          File != FileEnd && !EC; File.increment(EC)) {
1065       // We only care about module and global module index files.
1066       StringRef Extension = llvm::sys::path::extension(File->path());
1067       if (Extension != ".pcm" && Extension != ".timestamp" &&
1068           llvm::sys::path::filename(File->path()) != "modules.idx")
1069         continue;
1070 
1071       // Look at this file. If we can't stat it, there's nothing interesting
1072       // there.
1073       if (::stat(File->path().c_str(), &StatBuf))
1074         continue;
1075 
1076       // If the file has been used recently enough, leave it there.
1077       time_t FileAccessTime = StatBuf.st_atime;
1078       if (CurrentTime - FileAccessTime <=
1079               time_t(HSOpts.ModuleCachePruneAfter)) {
1080         continue;
1081       }
1082 
1083       // Remove the file.
1084       llvm::sys::fs::remove(File->path());
1085 
1086       // Remove the timestamp file.
1087       std::string TimpestampFilename = File->path() + ".timestamp";
1088       llvm::sys::fs::remove(TimpestampFilename);
1089     }
1090 
1091     // If we removed all of the files in the directory, remove the directory
1092     // itself.
1093     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1094             llvm::sys::fs::directory_iterator() && !EC)
1095       llvm::sys::fs::remove(Dir->path());
1096   }
1097 }
1098 
1099 ModuleLoadResult
1100 CompilerInstance::loadModule(SourceLocation ImportLoc,
1101                              ModuleIdPath Path,
1102                              Module::NameVisibilityKind Visibility,
1103                              bool IsInclusionDirective) {
1104   // Determine what file we're searching from.
1105   StringRef ModuleName = Path[0].first->getName();
1106   SourceLocation ModuleNameLoc = Path[0].second;
1107 
1108   // If we've already handled this import, just return the cached result.
1109   // This one-element cache is important to eliminate redundant diagnostics
1110   // when both the preprocessor and parser see the same import declaration.
1111   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1112     // Make the named module visible.
1113     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1114       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1115                                        ImportLoc, /*Complain=*/false);
1116     return LastModuleImportResult;
1117   }
1118 
1119   clang::Module *Module = 0;
1120 
1121   // If we don't already have information on this module, load the module now.
1122   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1123     = KnownModules.find(Path[0].first);
1124   if (Known != KnownModules.end()) {
1125     // Retrieve the cached top-level module.
1126     Module = Known->second;
1127   } else if (ModuleName == getLangOpts().CurrentModule) {
1128     // This is the module we're building.
1129     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1130     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1131   } else {
1132     // Search for a module with the given name.
1133     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1134     if (!Module) {
1135       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1136       << ModuleName
1137       << SourceRange(ImportLoc, ModuleNameLoc);
1138       ModuleBuildFailed = true;
1139       return ModuleLoadResult();
1140     }
1141 
1142     std::string ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1143 
1144     // If we don't already have an ASTReader, create one now.
1145     if (!ModuleManager) {
1146       if (!hasASTContext())
1147         createASTContext();
1148 
1149       // If we're not recursively building a module, check whether we
1150       // need to prune the module cache.
1151       if (getSourceManager().getModuleBuildStack().empty() &&
1152           getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1153           getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1154         pruneModuleCache(getHeaderSearchOpts());
1155       }
1156 
1157       HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
1158       std::string Sysroot = HSOpts.Sysroot;
1159       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1160       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1161                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1162                                     PPOpts.DisablePCHValidation,
1163                                     /*AllowASTWithCompilerErrors=*/false,
1164                                     /*AllowConfigurationMismatch=*/false,
1165                                     HSOpts.ModulesValidateSystemHeaders,
1166                                     getFrontendOpts().UseGlobalModuleIndex);
1167       if (hasASTConsumer()) {
1168         ModuleManager->setDeserializationListener(
1169           getASTConsumer().GetASTDeserializationListener());
1170         getASTContext().setASTMutationListener(
1171           getASTConsumer().GetASTMutationListener());
1172       }
1173       getASTContext().setExternalSource(ModuleManager);
1174       if (hasSema())
1175         ModuleManager->InitializeSema(getSema());
1176       if (hasASTConsumer())
1177         ModuleManager->StartTranslationUnit(&getASTConsumer());
1178     }
1179 
1180     if (TheDependencyFileGenerator)
1181       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
1182 
1183     // Try to load the module file.
1184     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1185     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1186                                    ImportLoc, ARRFlags)) {
1187     case ASTReader::Success:
1188       break;
1189 
1190     case ASTReader::OutOfDate:
1191     case ASTReader::Missing: {
1192       // The module file is missing or out-of-date. Build it.
1193       assert(Module && "missing module file");
1194       // Check whether there is a cycle in the module graph.
1195       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1196       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1197       for (; Pos != PosEnd; ++Pos) {
1198         if (Pos->first == ModuleName)
1199           break;
1200       }
1201 
1202       if (Pos != PosEnd) {
1203         SmallString<256> CyclePath;
1204         for (; Pos != PosEnd; ++Pos) {
1205           CyclePath += Pos->first;
1206           CyclePath += " -> ";
1207         }
1208         CyclePath += ModuleName;
1209 
1210         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1211           << ModuleName << CyclePath;
1212         return ModuleLoadResult();
1213       }
1214 
1215       // Check whether we have already attempted to build this module (but
1216       // failed).
1217       if (getPreprocessorOpts().FailedModules &&
1218           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1219         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1220           << ModuleName
1221           << SourceRange(ImportLoc, ModuleNameLoc);
1222         ModuleBuildFailed = true;
1223         return ModuleLoadResult();
1224       }
1225 
1226       // Try to compile the module.
1227       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1228 
1229       // Try to read the module file, now that we've compiled it.
1230       ASTReader::ASTReadResult ReadResult
1231         = ModuleManager->ReadAST(ModuleFileName,
1232                                  serialization::MK_Module, ImportLoc,
1233                                  ASTReader::ARR_Missing);
1234       if (ReadResult != ASTReader::Success) {
1235         if (ReadResult == ASTReader::Missing) {
1236           getDiagnostics().Report(ModuleNameLoc,
1237                                   Module? diag::err_module_not_built
1238                                         : diag::err_module_not_found)
1239             << ModuleName
1240             << SourceRange(ImportLoc, ModuleNameLoc);
1241         }
1242 
1243         if (getPreprocessorOpts().FailedModules)
1244           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1245         KnownModules[Path[0].first] = 0;
1246         ModuleBuildFailed = true;
1247         return ModuleLoadResult();
1248       }
1249 
1250       // Okay, we've rebuilt and now loaded the module.
1251       break;
1252     }
1253 
1254     case ASTReader::VersionMismatch:
1255     case ASTReader::ConfigurationMismatch:
1256     case ASTReader::HadErrors:
1257       ModuleLoader::HadFatalFailure = true;
1258       // FIXME: The ASTReader will already have complained, but can we showhorn
1259       // that diagnostic information into a more useful form?
1260       KnownModules[Path[0].first] = 0;
1261       return ModuleLoadResult();
1262 
1263     case ASTReader::Failure:
1264       ModuleLoader::HadFatalFailure = true;
1265       // Already complained, but note now that we failed.
1266       KnownModules[Path[0].first] = 0;
1267       ModuleBuildFailed = true;
1268       return ModuleLoadResult();
1269     }
1270 
1271     // Cache the result of this top-level module lookup for later.
1272     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1273   }
1274 
1275   // If we never found the module, fail.
1276   if (!Module)
1277     return ModuleLoadResult();
1278 
1279   // Verify that the rest of the module path actually corresponds to
1280   // a submodule.
1281   if (Path.size() > 1) {
1282     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1283       StringRef Name = Path[I].first->getName();
1284       clang::Module *Sub = Module->findSubmodule(Name);
1285 
1286       if (!Sub) {
1287         // Attempt to perform typo correction to find a module name that works.
1288         SmallVector<StringRef, 2> Best;
1289         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1290 
1291         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1292                                             JEnd = Module->submodule_end();
1293              J != JEnd; ++J) {
1294           unsigned ED = Name.edit_distance((*J)->Name,
1295                                            /*AllowReplacements=*/true,
1296                                            BestEditDistance);
1297           if (ED <= BestEditDistance) {
1298             if (ED < BestEditDistance) {
1299               Best.clear();
1300               BestEditDistance = ED;
1301             }
1302 
1303             Best.push_back((*J)->Name);
1304           }
1305         }
1306 
1307         // If there was a clear winner, user it.
1308         if (Best.size() == 1) {
1309           getDiagnostics().Report(Path[I].second,
1310                                   diag::err_no_submodule_suggest)
1311             << Path[I].first << Module->getFullModuleName() << Best[0]
1312             << SourceRange(Path[0].second, Path[I-1].second)
1313             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1314                                             Best[0]);
1315 
1316           Sub = Module->findSubmodule(Best[0]);
1317         }
1318       }
1319 
1320       if (!Sub) {
1321         // No submodule by this name. Complain, and don't look for further
1322         // submodules.
1323         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1324           << Path[I].first << Module->getFullModuleName()
1325           << SourceRange(Path[0].second, Path[I-1].second);
1326         break;
1327       }
1328 
1329       Module = Sub;
1330     }
1331   }
1332 
1333   // Make the named module visible, if it's not already part of the module
1334   // we are parsing.
1335   if (ModuleName != getLangOpts().CurrentModule) {
1336     if (!Module->IsFromModuleFile) {
1337       // We have an umbrella header or directory that doesn't actually include
1338       // all of the headers within the directory it covers. Complain about
1339       // this missing submodule and recover by forgetting that we ever saw
1340       // this submodule.
1341       // FIXME: Should we detect this at module load time? It seems fairly
1342       // expensive (and rare).
1343       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1344         << Module->getFullModuleName()
1345         << SourceRange(Path.front().second, Path.back().second);
1346 
1347       return ModuleLoadResult(0, true);
1348     }
1349 
1350     // Check whether this module is available.
1351     clang::Module::Requirement Requirement;
1352     clang::Module::HeaderDirective MissingHeader;
1353     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
1354                              MissingHeader)) {
1355       if (MissingHeader.FileNameLoc.isValid()) {
1356         getDiagnostics().Report(MissingHeader.FileNameLoc,
1357                                 diag::err_module_header_missing)
1358           << MissingHeader.IsUmbrella << MissingHeader.FileName;
1359       } else {
1360         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1361           << Module->getFullModuleName()
1362           << Requirement.second << Requirement.first
1363           << SourceRange(Path.front().second, Path.back().second);
1364       }
1365       LastModuleImportLoc = ImportLoc;
1366       LastModuleImportResult = ModuleLoadResult();
1367       return ModuleLoadResult();
1368     }
1369 
1370     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1371                                      /*Complain=*/true);
1372   }
1373 
1374   // Check for any configuration macros that have changed.
1375   clang::Module *TopModule = Module->getTopLevelModule();
1376   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1377     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1378                      Module, ImportLoc);
1379   }
1380 
1381   // If this module import was due to an inclusion directive, create an
1382   // implicit import declaration to capture it in the AST.
1383   if (IsInclusionDirective && hasASTContext()) {
1384     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1385     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1386                                                      ImportLoc, Module,
1387                                                      Path.back().second);
1388     TU->addDecl(ImportD);
1389     if (Consumer)
1390       Consumer->HandleImplicitImportDecl(ImportD);
1391   }
1392 
1393   LastModuleImportLoc = ImportLoc;
1394   LastModuleImportResult = ModuleLoadResult(Module, false);
1395   return LastModuleImportResult;
1396 }
1397 
1398 void CompilerInstance::makeModuleVisible(Module *Mod,
1399                                          Module::NameVisibilityKind Visibility,
1400                                          SourceLocation ImportLoc,
1401                                          bool Complain){
1402   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1403 }
1404 
1405