xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision c8130a74f498c5ca3d1d6276df392bae337cf221)
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 // Diagnostics
109 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
110                                const CodeGenOptions *CodeGenOpts,
111                                DiagnosticsEngine &Diags) {
112   std::string ErrorInfo;
113   bool OwnsStream = false;
114   raw_ostream *OS = &llvm::errs();
115   if (DiagOpts->DiagnosticLogFile != "-") {
116     // Create the output stream.
117     llvm::raw_fd_ostream *FileOS(
118         new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
119                                  llvm::sys::fs::F_Append));
120     if (!ErrorInfo.empty()) {
121       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
122         << DiagOpts->DiagnosticLogFile << ErrorInfo;
123     } else {
124       FileOS->SetUnbuffered();
125       FileOS->SetUseAtomicWrites(true);
126       OS = FileOS;
127       OwnsStream = true;
128     }
129   }
130 
131   // Chain in the diagnostic client which will log the diagnostics.
132   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
133                                                           OwnsStream);
134   if (CodeGenOpts)
135     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
136   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
137 }
138 
139 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
140                                        DiagnosticsEngine &Diags,
141                                        StringRef OutputFile) {
142   std::string ErrorInfo;
143   OwningPtr<llvm::raw_fd_ostream> OS;
144   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
145                                     llvm::sys::fs::F_Binary));
146 
147   if (!ErrorInfo.empty()) {
148     Diags.Report(diag::warn_fe_serialized_diag_failure)
149       << OutputFile << ErrorInfo;
150     return;
151   }
152 
153   DiagnosticConsumer *SerializedConsumer =
154     clang::serialized_diags::create(OS.take(), DiagOpts);
155 
156 
157   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
158                                                 SerializedConsumer));
159 }
160 
161 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
162                                          bool ShouldOwnClient) {
163   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
164                                   ShouldOwnClient, &getCodeGenOpts());
165 }
166 
167 IntrusiveRefCntPtr<DiagnosticsEngine>
168 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
169                                     DiagnosticConsumer *Client,
170                                     bool ShouldOwnClient,
171                                     const CodeGenOptions *CodeGenOpts) {
172   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
173   IntrusiveRefCntPtr<DiagnosticsEngine>
174       Diags(new DiagnosticsEngine(DiagID, Opts));
175 
176   // Create the diagnostic client for reporting errors or for
177   // implementing -verify.
178   if (Client) {
179     Diags->setClient(Client, ShouldOwnClient);
180   } else
181     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
182 
183   // Chain in -verify checker, if requested.
184   if (Opts->VerifyDiagnostics)
185     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
186 
187   // Chain in -diagnostic-log-file dumper, if requested.
188   if (!Opts->DiagnosticLogFile.empty())
189     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
190 
191   if (!Opts->DiagnosticSerializationFile.empty())
192     SetupSerializedDiagnostics(Opts, *Diags,
193                                Opts->DiagnosticSerializationFile);
194 
195   // Configure our handling of diagnostics.
196   ProcessWarningOptions(*Diags, *Opts);
197 
198   return Diags;
199 }
200 
201 // File Manager
202 
203 void CompilerInstance::createFileManager() {
204   if (!hasVirtualFileSystem()) {
205     // TODO: choose the virtual file system based on the CompilerInvocation.
206     setVirtualFileSystem(vfs::getRealFileSystem());
207   }
208   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
209 }
210 
211 // Source Manager
212 
213 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
214   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
215 }
216 
217 // Preprocessor
218 
219 void CompilerInstance::createPreprocessor() {
220   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
221 
222   // Create a PTH manager if we are using some form of a token cache.
223   PTHManager *PTHMgr = 0;
224   if (!PPOpts.TokenCache.empty())
225     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
226 
227   // Create the Preprocessor.
228   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
229                                               getSourceManager(),
230                                               getDiagnostics(),
231                                               getLangOpts(),
232                                               &getTarget());
233   PP = new Preprocessor(&getPreprocessorOpts(),
234                         getDiagnostics(), getLangOpts(), &getTarget(),
235                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
236                         /*OwnsHeaderSearch=*/true);
237 
238   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
239   // That argument is used as the IdentifierInfoLookup argument to
240   // IdentifierTable's ctor.
241   if (PTHMgr) {
242     PTHMgr->setPreprocessor(&*PP);
243     PP->setPTHManager(PTHMgr);
244   }
245 
246   if (PPOpts.DetailedRecord)
247     PP->createPreprocessingRecord();
248 
249   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
250 
251   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
252 
253   // Set up the module path, including the hash for the
254   // module-creation options.
255   SmallString<256> SpecificModuleCache(
256                            getHeaderSearchOpts().ModuleCachePath);
257   if (!getHeaderSearchOpts().DisableModuleHash)
258     llvm::sys::path::append(SpecificModuleCache,
259                             getInvocation().getModuleHash());
260   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
261 
262   // Handle generating dependencies, if requested.
263   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
264   if (!DepOpts.OutputFile.empty())
265     AttachDependencyFileGen(*PP, DepOpts);
266   if (!DepOpts.DOTOutputFile.empty())
267     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
268                              getHeaderSearchOpts().Sysroot);
269 
270 
271   // Handle generating header include information, if requested.
272   if (DepOpts.ShowHeaderIncludes)
273     AttachHeaderIncludeGen(*PP);
274   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
275     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
276     if (OutputPath == "-")
277       OutputPath = "";
278     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
279                            /*ShowDepth=*/false);
280   }
281 
282   if (DepOpts.PrintShowIncludes) {
283     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
284                            /*ShowDepth=*/true, /*MSStyle=*/true);
285   }
286 }
287 
288 // ASTContext
289 
290 void CompilerInstance::createASTContext() {
291   Preprocessor &PP = getPreprocessor();
292   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
293                            &getTarget(), PP.getIdentifierTable(),
294                            PP.getSelectorTable(), PP.getBuiltinInfo(),
295                            /*size_reserve=*/ 0);
296 }
297 
298 // ExternalASTSource
299 
300 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
301                                                   bool DisablePCHValidation,
302                                                 bool AllowPCHWithCompilerErrors,
303                                                  void *DeserializationListener){
304   OwningPtr<ExternalASTSource> Source;
305   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
306   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
307                                           DisablePCHValidation,
308                                           AllowPCHWithCompilerErrors,
309                                           getPreprocessor(), getASTContext(),
310                                           DeserializationListener,
311                                           Preamble,
312                                        getFrontendOpts().UseGlobalModuleIndex));
313   ModuleManager = static_cast<ASTReader*>(Source.get());
314   getASTContext().setExternalSource(Source);
315 }
316 
317 ExternalASTSource *
318 CompilerInstance::createPCHExternalASTSource(StringRef Path,
319                                              const std::string &Sysroot,
320                                              bool DisablePCHValidation,
321                                              bool AllowPCHWithCompilerErrors,
322                                              Preprocessor &PP,
323                                              ASTContext &Context,
324                                              void *DeserializationListener,
325                                              bool Preamble,
326                                              bool UseGlobalModuleIndex) {
327   OwningPtr<ASTReader> Reader;
328   Reader.reset(new ASTReader(PP, Context,
329                              Sysroot.empty() ? "" : Sysroot.c_str(),
330                              DisablePCHValidation,
331                              AllowPCHWithCompilerErrors,
332                              /*AllowConfigurationMismatch*/false,
333                              /*ValidateSystemInputs*/false,
334                              UseGlobalModuleIndex));
335 
336   Reader->setDeserializationListener(
337             static_cast<ASTDeserializationListener *>(DeserializationListener));
338   switch (Reader->ReadAST(Path,
339                           Preamble ? serialization::MK_Preamble
340                                    : serialization::MK_PCH,
341                           SourceLocation(),
342                           ASTReader::ARR_None)) {
343   case ASTReader::Success:
344     // Set the predefines buffer as suggested by the PCH reader. Typically, the
345     // predefines buffer will be empty.
346     PP.setPredefines(Reader->getSuggestedPredefines());
347     return Reader.take();
348 
349   case ASTReader::Failure:
350     // Unrecoverable failure: don't even try to process the input file.
351     break;
352 
353   case ASTReader::Missing:
354   case ASTReader::OutOfDate:
355   case ASTReader::VersionMismatch:
356   case ASTReader::ConfigurationMismatch:
357   case ASTReader::HadErrors:
358     // No suitable PCH file could be found. Return an error.
359     break;
360   }
361 
362   return 0;
363 }
364 
365 // Code Completion
366 
367 static bool EnableCodeCompletion(Preprocessor &PP,
368                                  const std::string &Filename,
369                                  unsigned Line,
370                                  unsigned Column) {
371   // Tell the source manager to chop off the given file at a specific
372   // line and column.
373   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
374   if (!Entry) {
375     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
376       << Filename;
377     return true;
378   }
379 
380   // Truncate the named file at the given line/column.
381   PP.SetCodeCompletionPoint(Entry, Line, Column);
382   return false;
383 }
384 
385 void CompilerInstance::createCodeCompletionConsumer() {
386   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
387   if (!CompletionConsumer) {
388     setCodeCompletionConsumer(
389       createCodeCompletionConsumer(getPreprocessor(),
390                                    Loc.FileName, Loc.Line, Loc.Column,
391                                    getFrontendOpts().CodeCompleteOpts,
392                                    llvm::outs()));
393     if (!CompletionConsumer)
394       return;
395   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
396                                   Loc.Line, Loc.Column)) {
397     setCodeCompletionConsumer(0);
398     return;
399   }
400 
401   if (CompletionConsumer->isOutputBinary() &&
402       llvm::sys::ChangeStdoutToBinary()) {
403     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
404     setCodeCompletionConsumer(0);
405   }
406 }
407 
408 void CompilerInstance::createFrontendTimer() {
409   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
410 }
411 
412 CodeCompleteConsumer *
413 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
414                                                const std::string &Filename,
415                                                unsigned Line,
416                                                unsigned Column,
417                                                const CodeCompleteOptions &Opts,
418                                                raw_ostream &OS) {
419   if (EnableCodeCompletion(PP, Filename, Line, Column))
420     return 0;
421 
422   // Set up the creation routine for code-completion.
423   return new PrintingCodeCompleteConsumer(Opts, OS);
424 }
425 
426 void CompilerInstance::createSema(TranslationUnitKind TUKind,
427                                   CodeCompleteConsumer *CompletionConsumer) {
428   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
429                          TUKind, CompletionConsumer));
430 }
431 
432 // Output Files
433 
434 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
435   assert(OutFile.OS && "Attempt to add empty stream to output list!");
436   OutputFiles.push_back(OutFile);
437 }
438 
439 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
440   for (std::list<OutputFile>::iterator
441          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
442     delete it->OS;
443     if (!it->TempFilename.empty()) {
444       if (EraseFiles) {
445         llvm::sys::fs::remove(it->TempFilename);
446       } else {
447         SmallString<128> NewOutFile(it->Filename);
448 
449         // If '-working-directory' was passed, the output filename should be
450         // relative to that.
451         FileMgr->FixupRelativePath(NewOutFile);
452         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
453                                                         NewOutFile.str())) {
454           getDiagnostics().Report(diag::err_unable_to_rename_temp)
455             << it->TempFilename << it->Filename << ec.message();
456 
457           llvm::sys::fs::remove(it->TempFilename);
458         }
459       }
460     } else if (!it->Filename.empty() && EraseFiles)
461       llvm::sys::fs::remove(it->Filename);
462 
463   }
464   OutputFiles.clear();
465 }
466 
467 llvm::raw_fd_ostream *
468 CompilerInstance::createDefaultOutputFile(bool Binary,
469                                           StringRef InFile,
470                                           StringRef Extension) {
471   return createOutputFile(getFrontendOpts().OutputFile, Binary,
472                           /*RemoveFileOnSignal=*/true, InFile, Extension,
473                           /*UseTemporary=*/true);
474 }
475 
476 llvm::raw_fd_ostream *
477 CompilerInstance::createOutputFile(StringRef OutputPath,
478                                    bool Binary, bool RemoveFileOnSignal,
479                                    StringRef InFile,
480                                    StringRef Extension,
481                                    bool UseTemporary,
482                                    bool CreateMissingDirectories) {
483   std::string Error, OutputPathName, TempPathName;
484   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
485                                               RemoveFileOnSignal,
486                                               InFile, Extension,
487                                               UseTemporary,
488                                               CreateMissingDirectories,
489                                               &OutputPathName,
490                                               &TempPathName);
491   if (!OS) {
492     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
493       << OutputPath << Error;
494     return 0;
495   }
496 
497   // Add the output file -- but don't try to remove "-", since this means we are
498   // using stdin.
499   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
500                 TempPathName, OS));
501 
502   return OS;
503 }
504 
505 llvm::raw_fd_ostream *
506 CompilerInstance::createOutputFile(StringRef OutputPath,
507                                    std::string &Error,
508                                    bool Binary,
509                                    bool RemoveFileOnSignal,
510                                    StringRef InFile,
511                                    StringRef Extension,
512                                    bool UseTemporary,
513                                    bool CreateMissingDirectories,
514                                    std::string *ResultPathName,
515                                    std::string *TempPathName) {
516   assert((!CreateMissingDirectories || UseTemporary) &&
517          "CreateMissingDirectories is only allowed when using temporary files");
518 
519   std::string OutFile, TempFile;
520   if (!OutputPath.empty()) {
521     OutFile = OutputPath;
522   } else if (InFile == "-") {
523     OutFile = "-";
524   } else if (!Extension.empty()) {
525     SmallString<128> Path(InFile);
526     llvm::sys::path::replace_extension(Path, Extension);
527     OutFile = Path.str();
528   } else {
529     OutFile = "-";
530   }
531 
532   OwningPtr<llvm::raw_fd_ostream> OS;
533   std::string OSFile;
534 
535   if (UseTemporary) {
536     if (OutFile == "-")
537       UseTemporary = false;
538     else {
539       llvm::sys::fs::file_status Status;
540       llvm::sys::fs::status(OutputPath, Status);
541       if (llvm::sys::fs::exists(Status)) {
542         // Fail early if we can't write to the final destination.
543         if (!llvm::sys::fs::can_write(OutputPath))
544           return 0;
545 
546         // Don't use a temporary if the output is a special file. This handles
547         // things like '-o /dev/null'
548         if (!llvm::sys::fs::is_regular_file(Status))
549           UseTemporary = false;
550       }
551     }
552   }
553 
554   if (UseTemporary) {
555     // Create a temporary file.
556     SmallString<128> TempPath;
557     TempPath = OutFile;
558     TempPath += "-%%%%%%%%";
559     int fd;
560     llvm::error_code EC =
561         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
562 
563     if (CreateMissingDirectories &&
564         EC == llvm::errc::no_such_file_or_directory) {
565       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
566       EC = llvm::sys::fs::create_directories(Parent);
567       if (!EC) {
568         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
569       }
570     }
571 
572     if (!EC) {
573       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
574       OSFile = TempFile = TempPath.str();
575     }
576     // If we failed to create the temporary, fallback to writing to the file
577     // directly. This handles the corner case where we cannot write to the
578     // directory, but can write to the file.
579   }
580 
581   if (!OS) {
582     OSFile = OutFile;
583     OS.reset(new llvm::raw_fd_ostream(
584         OSFile.c_str(), Error,
585         (Binary ? llvm::sys::fs::F_Binary : llvm::sys::fs::F_None)));
586     if (!Error.empty())
587       return 0;
588   }
589 
590   // Make sure the out stream file gets removed if we crash.
591   if (RemoveFileOnSignal)
592     llvm::sys::RemoveFileOnSignal(OSFile);
593 
594   if (ResultPathName)
595     *ResultPathName = OutFile;
596   if (TempPathName)
597     *TempPathName = TempFile;
598 
599   return OS.take();
600 }
601 
602 // Initialization Utilities
603 
604 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
605   return InitializeSourceManager(Input, getDiagnostics(),
606                                  getFileManager(), getSourceManager(),
607                                  getFrontendOpts());
608 }
609 
610 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
611                                                DiagnosticsEngine &Diags,
612                                                FileManager &FileMgr,
613                                                SourceManager &SourceMgr,
614                                                const FrontendOptions &Opts) {
615   SrcMgr::CharacteristicKind
616     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
617 
618   if (Input.isBuffer()) {
619     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
620     assert(!SourceMgr.getMainFileID().isInvalid() &&
621            "Couldn't establish MainFileID!");
622     return true;
623   }
624 
625   StringRef InputFile = Input.getFile();
626 
627   // Figure out where to get and map in the main file.
628   if (InputFile != "-") {
629     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
630     if (!File) {
631       Diags.Report(diag::err_fe_error_reading) << InputFile;
632       return false;
633     }
634 
635     // The natural SourceManager infrastructure can't currently handle named
636     // pipes, but we would at least like to accept them for the main
637     // file. Detect them here, read them with the volatile flag so FileMgr will
638     // pick up the correct size, and simply override their contents as we do for
639     // STDIN.
640     if (File->isNamedPipe()) {
641       std::string ErrorStr;
642       if (llvm::MemoryBuffer *MB =
643               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
644         // Create a new virtual file that will have the correct size.
645         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
646         SourceMgr.overrideFileContents(File, MB);
647       } else {
648         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
649         return false;
650       }
651     }
652 
653     SourceMgr.createMainFileID(File, Kind);
654   } else {
655     OwningPtr<llvm::MemoryBuffer> SB;
656     if (llvm::error_code ec = llvm::MemoryBuffer::getSTDIN(SB)) {
657       Diags.Report(diag::err_fe_error_reading_stdin) << ec.message();
658       return false;
659     }
660     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
661                                                    SB->getBufferSize(), 0);
662     SourceMgr.createMainFileID(File, Kind);
663     SourceMgr.overrideFileContents(File, SB.take());
664   }
665 
666   assert(!SourceMgr.getMainFileID().isInvalid() &&
667          "Couldn't establish MainFileID!");
668   return true;
669 }
670 
671 // High-Level Operations
672 
673 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
674   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
675   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
676   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
677 
678   // FIXME: Take this as an argument, once all the APIs we used have moved to
679   // taking it as an input instead of hard-coding llvm::errs.
680   raw_ostream &OS = llvm::errs();
681 
682   // Create the target instance.
683   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
684   if (!hasTarget())
685     return false;
686 
687   // Inform the target of the language options.
688   //
689   // FIXME: We shouldn't need to do this, the target should be immutable once
690   // created. This complexity should be lifted elsewhere.
691   getTarget().setForcedLangOptions(getLangOpts());
692 
693   // rewriter project will change target built-in bool type from its default.
694   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
695     getTarget().noSignedCharForObjCBool();
696 
697   // Validate/process some options.
698   if (getHeaderSearchOpts().Verbose)
699     OS << "clang -cc1 version " CLANG_VERSION_STRING
700        << " based upon " << PACKAGE_STRING
701        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
702 
703   if (getFrontendOpts().ShowTimers)
704     createFrontendTimer();
705 
706   if (getFrontendOpts().ShowStats)
707     llvm::EnableStatistics();
708 
709   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
710     // Reset the ID tables if we are reusing the SourceManager.
711     if (hasSourceManager())
712       getSourceManager().clearIDTables();
713 
714     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
715       Act.Execute();
716       Act.EndSourceFile();
717     }
718   }
719 
720   // Notify the diagnostic client that all files were processed.
721   getDiagnostics().getClient()->finish();
722 
723   if (getDiagnosticOpts().ShowCarets) {
724     // We can have multiple diagnostics sharing one diagnostic client.
725     // Get the total number of warnings/errors from the client.
726     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
727     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
728 
729     if (NumWarnings)
730       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
731     if (NumWarnings && NumErrors)
732       OS << " and ";
733     if (NumErrors)
734       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
735     if (NumWarnings || NumErrors)
736       OS << " generated.\n";
737   }
738 
739   if (getFrontendOpts().ShowStats && hasFileManager()) {
740     getFileManager().PrintStats();
741     OS << "\n";
742   }
743 
744   return !getDiagnostics().getClient()->getNumErrors();
745 }
746 
747 /// \brief Determine the appropriate source input kind based on language
748 /// options.
749 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
750   if (LangOpts.OpenCL)
751     return IK_OpenCL;
752   if (LangOpts.CUDA)
753     return IK_CUDA;
754   if (LangOpts.ObjC1)
755     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
756   return LangOpts.CPlusPlus? IK_CXX : IK_C;
757 }
758 
759 namespace {
760   struct CompileModuleMapData {
761     CompilerInstance &Instance;
762     GenerateModuleAction &CreateModuleAction;
763   };
764 }
765 
766 /// \brief Helper function that executes the module-generating action under
767 /// a crash recovery context.
768 static void doCompileMapModule(void *UserData) {
769   CompileModuleMapData &Data
770     = *reinterpret_cast<CompileModuleMapData *>(UserData);
771   Data.Instance.ExecuteAction(Data.CreateModuleAction);
772 }
773 
774 namespace {
775   /// \brief Function object that checks with the given macro definition should
776   /// be removed, because it is one of the ignored macros.
777   class RemoveIgnoredMacro {
778     const HeaderSearchOptions &HSOpts;
779 
780   public:
781     explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
782       : HSOpts(HSOpts) { }
783 
784     bool operator()(const std::pair<std::string, bool> &def) const {
785       StringRef MacroDef = def.first;
786       return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
787     }
788   };
789 }
790 
791 /// \brief Compile a module file for the given module, using the options
792 /// provided by the importing compiler instance.
793 static void compileModule(CompilerInstance &ImportingInstance,
794                           SourceLocation ImportLoc,
795                           Module *Module,
796                           StringRef ModuleFileName) {
797   // FIXME: have LockFileManager return an error_code so that we can
798   // avoid the mkdir when the directory already exists.
799   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
800   llvm::sys::fs::create_directories(Dir);
801 
802   llvm::LockFileManager Locked(ModuleFileName);
803   switch (Locked) {
804   case llvm::LockFileManager::LFS_Error:
805     return;
806 
807   case llvm::LockFileManager::LFS_Owned:
808     // We're responsible for building the module ourselves. Do so below.
809     break;
810 
811   case llvm::LockFileManager::LFS_Shared:
812     // Someone else is responsible for building the module. Wait for them to
813     // finish.
814     Locked.waitForUnlock();
815     return;
816   }
817 
818   ModuleMap &ModMap
819     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
820 
821   // Construct a compiler invocation for creating this module.
822   IntrusiveRefCntPtr<CompilerInvocation> Invocation
823     (new CompilerInvocation(ImportingInstance.getInvocation()));
824 
825   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
826 
827   // For any options that aren't intended to affect how a module is built,
828   // reset them to their default values.
829   Invocation->getLangOpts()->resetNonModularOptions();
830   PPOpts.resetNonModularOptions();
831 
832   // Remove any macro definitions that are explicitly ignored by the module.
833   // They aren't supposed to affect how the module is built anyway.
834   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
835   PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
836                                      RemoveIgnoredMacro(HSOpts)),
837                       PPOpts.Macros.end());
838 
839 
840   // Note the name of the module we're building.
841   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
842 
843   // Make sure that the failed-module structure has been allocated in
844   // the importing instance, and propagate the pointer to the newly-created
845   // instance.
846   PreprocessorOptions &ImportingPPOpts
847     = ImportingInstance.getInvocation().getPreprocessorOpts();
848   if (!ImportingPPOpts.FailedModules)
849     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
850   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
851 
852   // If there is a module map file, build the module using the module map.
853   // Set up the inputs/outputs so that we build the module from its umbrella
854   // header.
855   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
856   FrontendOpts.OutputFile = ModuleFileName.str();
857   FrontendOpts.DisableFree = false;
858   FrontendOpts.GenerateGlobalModuleIndex = false;
859   FrontendOpts.Inputs.clear();
860   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
861 
862   // Don't free the remapped file buffers; they are owned by our caller.
863   PPOpts.RetainRemappedFileBuffers = true;
864 
865   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
866   assert(ImportingInstance.getInvocation().getModuleHash() ==
867          Invocation->getModuleHash() && "Module hash mismatch!");
868 
869   // Construct a compiler instance that will be used to actually create the
870   // module.
871   CompilerInstance Instance;
872   Instance.setInvocation(&*Invocation);
873 
874   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
875                                    ImportingInstance.getDiagnosticClient()),
876                              /*ShouldOwnClient=*/true);
877 
878   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
879 
880   // Note that this module is part of the module build stack, so that we
881   // can detect cycles in the module graph.
882   Instance.createFileManager(); // FIXME: Adopt file manager from importer?
883   Instance.createSourceManager(Instance.getFileManager());
884   SourceManager &SourceMgr = Instance.getSourceManager();
885   SourceMgr.setModuleBuildStack(
886     ImportingInstance.getSourceManager().getModuleBuildStack());
887   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
888     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
889 
890   // Get or create the module map that we'll use to build this module.
891   std::string InferredModuleMapContent;
892   if (const FileEntry *ModuleMapFile =
893           ModMap.getContainingModuleMapFile(Module)) {
894     // Use the module map where this module resides.
895     FrontendOpts.Inputs.push_back(
896         FrontendInputFile(ModuleMapFile->getName(), IK));
897   } else {
898     llvm::raw_string_ostream OS(InferredModuleMapContent);
899     Module->print(OS);
900     OS.flush();
901     FrontendOpts.Inputs.push_back(
902         FrontendInputFile("__inferred_module.map", IK));
903 
904     const llvm::MemoryBuffer *ModuleMapBuffer =
905         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
906     ModuleMapFile = Instance.getFileManager().getVirtualFile(
907         "__inferred_module.map", InferredModuleMapContent.size(), 0);
908     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
909   }
910 
911   // Construct a module-generating action.
912   GenerateModuleAction CreateModuleAction(Module->IsSystem);
913 
914   // Execute the action to actually build the module in-place. Use a separate
915   // thread so that we get a stack large enough.
916   const unsigned ThreadStackSize = 8 << 20;
917   llvm::CrashRecoveryContext CRC;
918   CompileModuleMapData Data = { Instance, CreateModuleAction };
919   CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
920 
921 
922   // Delete the temporary module map file.
923   // FIXME: Even though we're executing under crash protection, it would still
924   // be nice to do this with RemoveFileOnSignal when we can. However, that
925   // doesn't make sense for all clients, so clean this up manually.
926   Instance.clearOutputFiles(/*EraseFiles=*/true);
927 
928   // We've rebuilt a module. If we're allowed to generate or update the global
929   // module index, record that fact in the importing compiler instance.
930   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
931     ImportingInstance.setBuildGlobalModuleIndex(true);
932   }
933 }
934 
935 /// \brief Diagnose differences between the current definition of the given
936 /// configuration macro and the definition provided on the command line.
937 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
938                              Module *Mod, SourceLocation ImportLoc) {
939   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
940   SourceManager &SourceMgr = PP.getSourceManager();
941 
942   // If this identifier has never had a macro definition, then it could
943   // not have changed.
944   if (!Id->hadMacroDefinition())
945     return;
946 
947   // If this identifier does not currently have a macro definition,
948   // check whether it had one on the command line.
949   if (!Id->hasMacroDefinition()) {
950     MacroDirective::DefInfo LatestDef =
951         PP.getMacroDirectiveHistory(Id)->getDefinition();
952     for (MacroDirective::DefInfo Def = LatestDef; Def;
953            Def = Def.getPreviousDefinition()) {
954       FileID FID = SourceMgr.getFileID(Def.getLocation());
955       if (FID.isInvalid())
956         continue;
957 
958       // We only care about the predefines buffer.
959       if (FID != PP.getPredefinesFileID())
960         continue;
961 
962       // This macro was defined on the command line, then #undef'd later.
963       // Complain.
964       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
965         << true << ConfigMacro << Mod->getFullModuleName();
966       if (LatestDef.isUndefined())
967         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
968           << true;
969       return;
970     }
971 
972     // Okay: no definition in the predefines buffer.
973     return;
974   }
975 
976   // This identifier has a macro definition. Check whether we had a definition
977   // on the command line.
978   MacroDirective::DefInfo LatestDef =
979       PP.getMacroDirectiveHistory(Id)->getDefinition();
980   MacroDirective::DefInfo PredefinedDef;
981   for (MacroDirective::DefInfo Def = LatestDef; Def;
982          Def = Def.getPreviousDefinition()) {
983     FileID FID = SourceMgr.getFileID(Def.getLocation());
984     if (FID.isInvalid())
985       continue;
986 
987     // We only care about the predefines buffer.
988     if (FID != PP.getPredefinesFileID())
989       continue;
990 
991     PredefinedDef = Def;
992     break;
993   }
994 
995   // If there was no definition for this macro in the predefines buffer,
996   // complain.
997   if (!PredefinedDef ||
998       (!PredefinedDef.getLocation().isValid() &&
999        PredefinedDef.getUndefLocation().isValid())) {
1000     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1001       << false << ConfigMacro << Mod->getFullModuleName();
1002     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1003       << false;
1004     return;
1005   }
1006 
1007   // If the current macro definition is the same as the predefined macro
1008   // definition, it's okay.
1009   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
1010       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1011                                               /*Syntactically=*/true))
1012     return;
1013 
1014   // The macro definitions differ.
1015   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1016     << false << ConfigMacro << Mod->getFullModuleName();
1017   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1018     << false;
1019 }
1020 
1021 /// \brief Write a new timestamp file with the given path.
1022 static void writeTimestampFile(StringRef TimestampFile) {
1023   std::string ErrorInfo;
1024   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1025                            llvm::sys::fs::F_Binary);
1026 }
1027 
1028 /// \brief Prune the module cache of modules that haven't been accessed in
1029 /// a long time.
1030 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1031   struct stat StatBuf;
1032   llvm::SmallString<128> TimestampFile;
1033   TimestampFile = HSOpts.ModuleCachePath;
1034   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1035 
1036   // Try to stat() the timestamp file.
1037   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1038     // If the timestamp file wasn't there, create one now.
1039     if (errno == ENOENT) {
1040       writeTimestampFile(TimestampFile);
1041     }
1042     return;
1043   }
1044 
1045   // Check whether the time stamp is older than our pruning interval.
1046   // If not, do nothing.
1047   time_t TimeStampModTime = StatBuf.st_mtime;
1048   time_t CurrentTime = time(0);
1049   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1050     return;
1051 
1052   // Write a new timestamp file so that nobody else attempts to prune.
1053   // There is a benign race condition here, if two Clang instances happen to
1054   // notice at the same time that the timestamp is out-of-date.
1055   writeTimestampFile(TimestampFile);
1056 
1057   // Walk the entire module cache, looking for unused module files and module
1058   // indices.
1059   llvm::error_code EC;
1060   SmallString<128> ModuleCachePathNative;
1061   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1062   for (llvm::sys::fs::directory_iterator
1063          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1064        Dir != DirEnd && !EC; Dir.increment(EC)) {
1065     // If we don't have a directory, there's nothing to look into.
1066     if (!llvm::sys::fs::is_directory(Dir->path()))
1067       continue;
1068 
1069     // Walk all of the files within this directory.
1070     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1071          File != FileEnd && !EC; File.increment(EC)) {
1072       // We only care about module and global module index files.
1073       StringRef Extension = llvm::sys::path::extension(File->path());
1074       if (Extension != ".pcm" && Extension != ".timestamp" &&
1075           llvm::sys::path::filename(File->path()) != "modules.idx")
1076         continue;
1077 
1078       // Look at this file. If we can't stat it, there's nothing interesting
1079       // there.
1080       if (::stat(File->path().c_str(), &StatBuf))
1081         continue;
1082 
1083       // If the file has been used recently enough, leave it there.
1084       time_t FileAccessTime = StatBuf.st_atime;
1085       if (CurrentTime - FileAccessTime <=
1086               time_t(HSOpts.ModuleCachePruneAfter)) {
1087         continue;
1088       }
1089 
1090       // Remove the file.
1091       llvm::sys::fs::remove(File->path());
1092 
1093       // Remove the timestamp file.
1094       std::string TimpestampFilename = File->path() + ".timestamp";
1095       llvm::sys::fs::remove(TimpestampFilename);
1096     }
1097 
1098     // If we removed all of the files in the directory, remove the directory
1099     // itself.
1100     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1101             llvm::sys::fs::directory_iterator() && !EC)
1102       llvm::sys::fs::remove(Dir->path());
1103   }
1104 }
1105 
1106 ModuleLoadResult
1107 CompilerInstance::loadModule(SourceLocation ImportLoc,
1108                              ModuleIdPath Path,
1109                              Module::NameVisibilityKind Visibility,
1110                              bool IsInclusionDirective) {
1111   // Determine what file we're searching from.
1112   StringRef ModuleName = Path[0].first->getName();
1113   SourceLocation ModuleNameLoc = Path[0].second;
1114 
1115   // If we've already handled this import, just return the cached result.
1116   // This one-element cache is important to eliminate redundant diagnostics
1117   // when both the preprocessor and parser see the same import declaration.
1118   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1119     // Make the named module visible.
1120     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1121       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1122                                        ImportLoc, /*Complain=*/false);
1123     return LastModuleImportResult;
1124   }
1125 
1126   clang::Module *Module = 0;
1127 
1128   // If we don't already have information on this module, load the module now.
1129   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1130     = KnownModules.find(Path[0].first);
1131   if (Known != KnownModules.end()) {
1132     // Retrieve the cached top-level module.
1133     Module = Known->second;
1134   } else if (ModuleName == getLangOpts().CurrentModule) {
1135     // This is the module we're building.
1136     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1137     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1138   } else {
1139     // Search for a module with the given name.
1140     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1141     if (!Module) {
1142       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1143       << ModuleName
1144       << SourceRange(ImportLoc, ModuleNameLoc);
1145       ModuleBuildFailed = true;
1146       return ModuleLoadResult();
1147     }
1148 
1149     std::string ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1150 
1151     // If we don't already have an ASTReader, create one now.
1152     if (!ModuleManager) {
1153       if (!hasASTContext())
1154         createASTContext();
1155 
1156       // If we're not recursively building a module, check whether we
1157       // need to prune the module cache.
1158       if (getSourceManager().getModuleBuildStack().empty() &&
1159           getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1160           getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1161         pruneModuleCache(getHeaderSearchOpts());
1162       }
1163 
1164       std::string Sysroot = getHeaderSearchOpts().Sysroot;
1165       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1166       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1167                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1168                                     PPOpts.DisablePCHValidation,
1169                                     /*AllowASTWithCompilerErrors=*/false,
1170                                     /*AllowConfigurationMismatch=*/false,
1171                                     /*ValidateSystemInputs=*/false,
1172                                     getFrontendOpts().UseGlobalModuleIndex);
1173       if (hasASTConsumer()) {
1174         ModuleManager->setDeserializationListener(
1175           getASTConsumer().GetASTDeserializationListener());
1176         getASTContext().setASTMutationListener(
1177           getASTConsumer().GetASTMutationListener());
1178       }
1179       OwningPtr<ExternalASTSource> Source;
1180       Source.reset(ModuleManager);
1181       getASTContext().setExternalSource(Source);
1182       if (hasSema())
1183         ModuleManager->InitializeSema(getSema());
1184       if (hasASTConsumer())
1185         ModuleManager->StartTranslationUnit(&getASTConsumer());
1186     }
1187 
1188     // Try to load the module file.
1189     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1190     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1191                                    ImportLoc, ARRFlags)) {
1192     case ASTReader::Success:
1193       break;
1194 
1195     case ASTReader::OutOfDate:
1196     case ASTReader::Missing: {
1197       // The module file is missing or out-of-date. Build it.
1198       assert(Module && "missing module file");
1199       // Check whether there is a cycle in the module graph.
1200       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1201       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1202       for (; Pos != PosEnd; ++Pos) {
1203         if (Pos->first == ModuleName)
1204           break;
1205       }
1206 
1207       if (Pos != PosEnd) {
1208         SmallString<256> CyclePath;
1209         for (; Pos != PosEnd; ++Pos) {
1210           CyclePath += Pos->first;
1211           CyclePath += " -> ";
1212         }
1213         CyclePath += ModuleName;
1214 
1215         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1216           << ModuleName << CyclePath;
1217         return ModuleLoadResult();
1218       }
1219 
1220       // Check whether we have already attempted to build this module (but
1221       // failed).
1222       if (getPreprocessorOpts().FailedModules &&
1223           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1224         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1225           << ModuleName
1226           << SourceRange(ImportLoc, ModuleNameLoc);
1227         ModuleBuildFailed = true;
1228         return ModuleLoadResult();
1229       }
1230 
1231       // Try to compile the module.
1232       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1233 
1234       // Try to read the module file, now that we've compiled it.
1235       ASTReader::ASTReadResult ReadResult
1236         = ModuleManager->ReadAST(ModuleFileName,
1237                                  serialization::MK_Module, ImportLoc,
1238                                  ASTReader::ARR_Missing);
1239       if (ReadResult != ASTReader::Success) {
1240         if (ReadResult == ASTReader::Missing) {
1241           getDiagnostics().Report(ModuleNameLoc,
1242                                   Module? diag::err_module_not_built
1243                                         : diag::err_module_not_found)
1244             << ModuleName
1245             << SourceRange(ImportLoc, ModuleNameLoc);
1246         }
1247 
1248         if (getPreprocessorOpts().FailedModules)
1249           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1250         KnownModules[Path[0].first] = 0;
1251         ModuleBuildFailed = true;
1252         return ModuleLoadResult();
1253       }
1254 
1255       // Okay, we've rebuilt and now loaded the module.
1256       break;
1257     }
1258 
1259     case ASTReader::VersionMismatch:
1260     case ASTReader::ConfigurationMismatch:
1261     case ASTReader::HadErrors:
1262       ModuleLoader::HadFatalFailure = true;
1263       // FIXME: The ASTReader will already have complained, but can we showhorn
1264       // that diagnostic information into a more useful form?
1265       KnownModules[Path[0].first] = 0;
1266       return ModuleLoadResult();
1267 
1268     case ASTReader::Failure:
1269       ModuleLoader::HadFatalFailure = true;
1270       // Already complained, but note now that we failed.
1271       KnownModules[Path[0].first] = 0;
1272       ModuleBuildFailed = true;
1273       return ModuleLoadResult();
1274     }
1275 
1276     // Cache the result of this top-level module lookup for later.
1277     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1278   }
1279 
1280   // If we never found the module, fail.
1281   if (!Module)
1282     return ModuleLoadResult();
1283 
1284   // Verify that the rest of the module path actually corresponds to
1285   // a submodule.
1286   if (Path.size() > 1) {
1287     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1288       StringRef Name = Path[I].first->getName();
1289       clang::Module *Sub = Module->findSubmodule(Name);
1290 
1291       if (!Sub) {
1292         // Attempt to perform typo correction to find a module name that works.
1293         SmallVector<StringRef, 2> Best;
1294         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1295 
1296         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1297                                             JEnd = Module->submodule_end();
1298              J != JEnd; ++J) {
1299           unsigned ED = Name.edit_distance((*J)->Name,
1300                                            /*AllowReplacements=*/true,
1301                                            BestEditDistance);
1302           if (ED <= BestEditDistance) {
1303             if (ED < BestEditDistance) {
1304               Best.clear();
1305               BestEditDistance = ED;
1306             }
1307 
1308             Best.push_back((*J)->Name);
1309           }
1310         }
1311 
1312         // If there was a clear winner, user it.
1313         if (Best.size() == 1) {
1314           getDiagnostics().Report(Path[I].second,
1315                                   diag::err_no_submodule_suggest)
1316             << Path[I].first << Module->getFullModuleName() << Best[0]
1317             << SourceRange(Path[0].second, Path[I-1].second)
1318             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1319                                             Best[0]);
1320 
1321           Sub = Module->findSubmodule(Best[0]);
1322         }
1323       }
1324 
1325       if (!Sub) {
1326         // No submodule by this name. Complain, and don't look for further
1327         // submodules.
1328         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1329           << Path[I].first << Module->getFullModuleName()
1330           << SourceRange(Path[0].second, Path[I-1].second);
1331         break;
1332       }
1333 
1334       Module = Sub;
1335     }
1336   }
1337 
1338   // Make the named module visible, if it's not already part of the module
1339   // we are parsing.
1340   if (ModuleName != getLangOpts().CurrentModule) {
1341     if (!Module->IsFromModuleFile) {
1342       // We have an umbrella header or directory that doesn't actually include
1343       // all of the headers within the directory it covers. Complain about
1344       // this missing submodule and recover by forgetting that we ever saw
1345       // this submodule.
1346       // FIXME: Should we detect this at module load time? It seems fairly
1347       // expensive (and rare).
1348       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1349         << Module->getFullModuleName()
1350         << SourceRange(Path.front().second, Path.back().second);
1351 
1352       return ModuleLoadResult(0, true);
1353     }
1354 
1355     // Check whether this module is available.
1356     clang::Module::Requirement Requirement;
1357     clang::Module::HeaderDirective MissingHeader;
1358     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
1359                              MissingHeader)) {
1360       if (MissingHeader.FileNameLoc.isValid()) {
1361         getDiagnostics().Report(MissingHeader.FileNameLoc,
1362                                 diag::err_module_header_missing)
1363           << MissingHeader.IsUmbrella << MissingHeader.FileName;
1364       } else {
1365         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1366           << Module->getFullModuleName()
1367           << Requirement.second << Requirement.first
1368           << SourceRange(Path.front().second, Path.back().second);
1369       }
1370       LastModuleImportLoc = ImportLoc;
1371       LastModuleImportResult = ModuleLoadResult();
1372       return ModuleLoadResult();
1373     }
1374 
1375     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1376                                      /*Complain=*/true);
1377   }
1378 
1379   // Check for any configuration macros that have changed.
1380   clang::Module *TopModule = Module->getTopLevelModule();
1381   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1382     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1383                      Module, ImportLoc);
1384   }
1385 
1386   // If this module import was due to an inclusion directive, create an
1387   // implicit import declaration to capture it in the AST.
1388   if (IsInclusionDirective && hasASTContext()) {
1389     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1390     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1391                                                      ImportLoc, Module,
1392                                                      Path.back().second);
1393     TU->addDecl(ImportD);
1394     if (Consumer)
1395       Consumer->HandleImplicitImportDecl(ImportD);
1396   }
1397 
1398   LastModuleImportLoc = ImportLoc;
1399   LastModuleImportResult = ModuleLoadResult(Module, false);
1400   return LastModuleImportResult;
1401 }
1402 
1403 void CompilerInstance::makeModuleVisible(Module *Mod,
1404                                          Module::NameVisibilityKind Visibility,
1405                                          SourceLocation ImportLoc,
1406                                          bool Complain){
1407   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1408 }
1409 
1410