xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision 11ef0b7778e5a8d18f75b4969acbcd8b86b0cbc4)
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 
48 using namespace clang;
49 
50 CompilerInstance::CompilerInstance()
51   : Invocation(new CompilerInvocation()), ModuleManager(0),
52     BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
53 }
54 
55 CompilerInstance::~CompilerInstance() {
56   assert(OutputFiles.empty() && "Still output files in flight?");
57 }
58 
59 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
60   Invocation = Value;
61 }
62 
63 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
64   return (BuildGlobalModuleIndex ||
65           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
66            getFrontendOpts().GenerateGlobalModuleIndex)) &&
67          !ModuleBuildFailed;
68 }
69 
70 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
71   Diagnostics = Value;
72 }
73 
74 void CompilerInstance::setTarget(TargetInfo *Value) {
75   Target = Value;
76 }
77 
78 void CompilerInstance::setFileManager(FileManager *Value) {
79   FileMgr = Value;
80 }
81 
82 void CompilerInstance::setSourceManager(SourceManager *Value) {
83   SourceMgr = Value;
84 }
85 
86 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
87 
88 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
89 
90 void CompilerInstance::setSema(Sema *S) {
91   TheSema.reset(S);
92 }
93 
94 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
95   Consumer.reset(Value);
96 }
97 
98 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
99   CompletionConsumer.reset(Value);
100 }
101 
102 // Diagnostics
103 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
104                                const CodeGenOptions *CodeGenOpts,
105                                DiagnosticsEngine &Diags) {
106   std::string ErrorInfo;
107   bool OwnsStream = false;
108   raw_ostream *OS = &llvm::errs();
109   if (DiagOpts->DiagnosticLogFile != "-") {
110     // Create the output stream.
111     llvm::raw_fd_ostream *FileOS(
112       new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(),
113                                ErrorInfo, llvm::raw_fd_ostream::F_Append));
114     if (!ErrorInfo.empty()) {
115       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
116         << DiagOpts->DiagnosticLogFile << ErrorInfo;
117     } else {
118       FileOS->SetUnbuffered();
119       FileOS->SetUseAtomicWrites(true);
120       OS = FileOS;
121       OwnsStream = true;
122     }
123   }
124 
125   // Chain in the diagnostic client which will log the diagnostics.
126   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
127                                                           OwnsStream);
128   if (CodeGenOpts)
129     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
130   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
131 }
132 
133 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
134                                        DiagnosticsEngine &Diags,
135                                        StringRef OutputFile) {
136   std::string ErrorInfo;
137   OwningPtr<llvm::raw_fd_ostream> OS;
138   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
139                                     llvm::raw_fd_ostream::F_Binary));
140 
141   if (!ErrorInfo.empty()) {
142     Diags.Report(diag::warn_fe_serialized_diag_failure)
143       << OutputFile << ErrorInfo;
144     return;
145   }
146 
147   DiagnosticConsumer *SerializedConsumer =
148     clang::serialized_diags::create(OS.take(), DiagOpts);
149 
150 
151   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
152                                                 SerializedConsumer));
153 }
154 
155 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
156                                          bool ShouldOwnClient,
157                                          bool ShouldCloneClient) {
158   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
159                                   ShouldOwnClient, ShouldCloneClient,
160                                   &getCodeGenOpts());
161 }
162 
163 IntrusiveRefCntPtr<DiagnosticsEngine>
164 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
165                                     DiagnosticConsumer *Client,
166                                     bool ShouldOwnClient,
167                                     bool ShouldCloneClient,
168                                     const CodeGenOptions *CodeGenOpts) {
169   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
170   IntrusiveRefCntPtr<DiagnosticsEngine>
171       Diags(new DiagnosticsEngine(DiagID, Opts));
172 
173   // Create the diagnostic client for reporting errors or for
174   // implementing -verify.
175   if (Client) {
176     if (ShouldCloneClient)
177       Diags->setClient(Client->clone(*Diags), ShouldOwnClient);
178     else
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   FileMgr = new FileManager(getFileSystemOpts());
205 }
206 
207 // Source Manager
208 
209 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
210   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
211 }
212 
213 // Preprocessor
214 
215 void CompilerInstance::createPreprocessor() {
216   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
217 
218   // Create a PTH manager if we are using some form of a token cache.
219   PTHManager *PTHMgr = 0;
220   if (!PPOpts.TokenCache.empty())
221     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
222 
223   // Create the Preprocessor.
224   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
225                                               getFileManager(),
226                                               getDiagnostics(),
227                                               getLangOpts(),
228                                               &getTarget());
229   PP = new Preprocessor(&getPreprocessorOpts(),
230                         getDiagnostics(), getLangOpts(), &getTarget(),
231                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
232                         /*OwnsHeaderSearch=*/true);
233 
234   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
235   // That argument is used as the IdentifierInfoLookup argument to
236   // IdentifierTable's ctor.
237   if (PTHMgr) {
238     PTHMgr->setPreprocessor(&*PP);
239     PP->setPTHManager(PTHMgr);
240   }
241 
242   if (PPOpts.DetailedRecord)
243     PP->createPreprocessingRecord();
244 
245   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
246 
247   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
248 
249   // Set up the module path, including the hash for the
250   // module-creation options.
251   SmallString<256> SpecificModuleCache(
252                            getHeaderSearchOpts().ModuleCachePath);
253   if (!getHeaderSearchOpts().DisableModuleHash)
254     llvm::sys::path::append(SpecificModuleCache,
255                             getInvocation().getModuleHash());
256   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
257 
258   // Handle generating dependencies, if requested.
259   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
260   if (!DepOpts.OutputFile.empty())
261     AttachDependencyFileGen(*PP, DepOpts);
262   if (!DepOpts.DOTOutputFile.empty())
263     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
264                              getHeaderSearchOpts().Sysroot);
265 
266 
267   // Handle generating header include information, if requested.
268   if (DepOpts.ShowHeaderIncludes)
269     AttachHeaderIncludeGen(*PP);
270   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
271     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
272     if (OutputPath == "-")
273       OutputPath = "";
274     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
275                            /*ShowDepth=*/false);
276   }
277 }
278 
279 // ASTContext
280 
281 void CompilerInstance::createASTContext() {
282   Preprocessor &PP = getPreprocessor();
283   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
284                            &getTarget(), PP.getIdentifierTable(),
285                            PP.getSelectorTable(), PP.getBuiltinInfo(),
286                            /*size_reserve=*/ 0);
287 }
288 
289 // ExternalASTSource
290 
291 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
292                                                   bool DisablePCHValidation,
293                                                 bool AllowPCHWithCompilerErrors,
294                                                  void *DeserializationListener){
295   OwningPtr<ExternalASTSource> Source;
296   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
297   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
298                                           DisablePCHValidation,
299                                           AllowPCHWithCompilerErrors,
300                                           getPreprocessor(), getASTContext(),
301                                           DeserializationListener,
302                                           Preamble,
303                                        getFrontendOpts().UseGlobalModuleIndex));
304   ModuleManager = static_cast<ASTReader*>(Source.get());
305   getASTContext().setExternalSource(Source);
306 }
307 
308 ExternalASTSource *
309 CompilerInstance::createPCHExternalASTSource(StringRef Path,
310                                              const std::string &Sysroot,
311                                              bool DisablePCHValidation,
312                                              bool AllowPCHWithCompilerErrors,
313                                              Preprocessor &PP,
314                                              ASTContext &Context,
315                                              void *DeserializationListener,
316                                              bool Preamble,
317                                              bool UseGlobalModuleIndex) {
318   OwningPtr<ASTReader> Reader;
319   Reader.reset(new ASTReader(PP, Context,
320                              Sysroot.empty() ? "" : Sysroot.c_str(),
321                              DisablePCHValidation,
322                              AllowPCHWithCompilerErrors,
323                              UseGlobalModuleIndex));
324 
325   Reader->setDeserializationListener(
326             static_cast<ASTDeserializationListener *>(DeserializationListener));
327   switch (Reader->ReadAST(Path,
328                           Preamble ? serialization::MK_Preamble
329                                    : serialization::MK_PCH,
330                           SourceLocation(),
331                           ASTReader::ARR_None)) {
332   case ASTReader::Success:
333     // Set the predefines buffer as suggested by the PCH reader. Typically, the
334     // predefines buffer will be empty.
335     PP.setPredefines(Reader->getSuggestedPredefines());
336     return Reader.take();
337 
338   case ASTReader::Failure:
339     // Unrecoverable failure: don't even try to process the input file.
340     break;
341 
342   case ASTReader::Missing:
343   case ASTReader::OutOfDate:
344   case ASTReader::VersionMismatch:
345   case ASTReader::ConfigurationMismatch:
346   case ASTReader::HadErrors:
347     // No suitable PCH file could be found. Return an error.
348     break;
349   }
350 
351   return 0;
352 }
353 
354 // Code Completion
355 
356 static bool EnableCodeCompletion(Preprocessor &PP,
357                                  const std::string &Filename,
358                                  unsigned Line,
359                                  unsigned Column) {
360   // Tell the source manager to chop off the given file at a specific
361   // line and column.
362   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
363   if (!Entry) {
364     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
365       << Filename;
366     return true;
367   }
368 
369   // Truncate the named file at the given line/column.
370   PP.SetCodeCompletionPoint(Entry, Line, Column);
371   return false;
372 }
373 
374 void CompilerInstance::createCodeCompletionConsumer() {
375   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
376   if (!CompletionConsumer) {
377     setCodeCompletionConsumer(
378       createCodeCompletionConsumer(getPreprocessor(),
379                                    Loc.FileName, Loc.Line, Loc.Column,
380                                    getFrontendOpts().CodeCompleteOpts,
381                                    llvm::outs()));
382     if (!CompletionConsumer)
383       return;
384   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
385                                   Loc.Line, Loc.Column)) {
386     setCodeCompletionConsumer(0);
387     return;
388   }
389 
390   if (CompletionConsumer->isOutputBinary() &&
391       llvm::sys::Program::ChangeStdoutToBinary()) {
392     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
393     setCodeCompletionConsumer(0);
394   }
395 }
396 
397 void CompilerInstance::createFrontendTimer() {
398   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
399 }
400 
401 CodeCompleteConsumer *
402 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
403                                                const std::string &Filename,
404                                                unsigned Line,
405                                                unsigned Column,
406                                                const CodeCompleteOptions &Opts,
407                                                raw_ostream &OS) {
408   if (EnableCodeCompletion(PP, Filename, Line, Column))
409     return 0;
410 
411   // Set up the creation routine for code-completion.
412   return new PrintingCodeCompleteConsumer(Opts, OS);
413 }
414 
415 void CompilerInstance::createSema(TranslationUnitKind TUKind,
416                                   CodeCompleteConsumer *CompletionConsumer) {
417   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
418                          TUKind, CompletionConsumer));
419 }
420 
421 // Output Files
422 
423 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
424   assert(OutFile.OS && "Attempt to add empty stream to output list!");
425   OutputFiles.push_back(OutFile);
426 }
427 
428 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
429   for (std::list<OutputFile>::iterator
430          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
431     delete it->OS;
432     if (!it->TempFilename.empty()) {
433       if (EraseFiles) {
434         bool existed;
435         llvm::sys::fs::remove(it->TempFilename, existed);
436       } else {
437         SmallString<128> NewOutFile(it->Filename);
438 
439         // If '-working-directory' was passed, the output filename should be
440         // relative to that.
441         FileMgr->FixupRelativePath(NewOutFile);
442         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
443                                                         NewOutFile.str())) {
444           getDiagnostics().Report(diag::err_unable_to_rename_temp)
445             << it->TempFilename << it->Filename << ec.message();
446 
447           bool existed;
448           llvm::sys::fs::remove(it->TempFilename, existed);
449         }
450       }
451     } else if (!it->Filename.empty() && EraseFiles)
452       llvm::sys::Path(it->Filename).eraseFromDisk();
453 
454   }
455   OutputFiles.clear();
456 }
457 
458 llvm::raw_fd_ostream *
459 CompilerInstance::createDefaultOutputFile(bool Binary,
460                                           StringRef InFile,
461                                           StringRef Extension) {
462   return createOutputFile(getFrontendOpts().OutputFile, Binary,
463                           /*RemoveFileOnSignal=*/true, InFile, Extension,
464                           /*UseTemporary=*/true);
465 }
466 
467 llvm::raw_fd_ostream *
468 CompilerInstance::createOutputFile(StringRef OutputPath,
469                                    bool Binary, bool RemoveFileOnSignal,
470                                    StringRef InFile,
471                                    StringRef Extension,
472                                    bool UseTemporary,
473                                    bool CreateMissingDirectories) {
474   std::string Error, OutputPathName, TempPathName;
475   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
476                                               RemoveFileOnSignal,
477                                               InFile, Extension,
478                                               UseTemporary,
479                                               CreateMissingDirectories,
480                                               &OutputPathName,
481                                               &TempPathName);
482   if (!OS) {
483     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
484       << OutputPath << Error;
485     return 0;
486   }
487 
488   // Add the output file -- but don't try to remove "-", since this means we are
489   // using stdin.
490   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
491                 TempPathName, OS));
492 
493   return OS;
494 }
495 
496 llvm::raw_fd_ostream *
497 CompilerInstance::createOutputFile(StringRef OutputPath,
498                                    std::string &Error,
499                                    bool Binary,
500                                    bool RemoveFileOnSignal,
501                                    StringRef InFile,
502                                    StringRef Extension,
503                                    bool UseTemporary,
504                                    bool CreateMissingDirectories,
505                                    std::string *ResultPathName,
506                                    std::string *TempPathName) {
507   assert((!CreateMissingDirectories || UseTemporary) &&
508          "CreateMissingDirectories is only allowed when using temporary files");
509 
510   std::string OutFile, TempFile;
511   if (!OutputPath.empty()) {
512     OutFile = OutputPath;
513   } else if (InFile == "-") {
514     OutFile = "-";
515   } else if (!Extension.empty()) {
516     llvm::sys::Path Path(InFile);
517     Path.eraseSuffix();
518     Path.appendSuffix(Extension);
519     OutFile = Path.str();
520   } else {
521     OutFile = "-";
522   }
523 
524   OwningPtr<llvm::raw_fd_ostream> OS;
525   std::string OSFile;
526 
527   if (UseTemporary && OutFile != "-") {
528     // Only create the temporary if the parent directory exists (or create
529     // missing directories is true) and we can actually write to OutPath,
530     // otherwise we want to fail early.
531     SmallString<256> AbsPath(OutputPath);
532     llvm::sys::fs::make_absolute(AbsPath);
533     llvm::sys::Path OutPath(AbsPath);
534     bool ParentExists = false;
535     if (llvm::sys::fs::exists(llvm::sys::path::parent_path(AbsPath.str()),
536                               ParentExists))
537       ParentExists = false;
538     bool Exists;
539     if ((CreateMissingDirectories || ParentExists) &&
540         ((llvm::sys::fs::exists(AbsPath.str(), Exists) || !Exists) ||
541          (OutPath.isRegularFile() && OutPath.canWrite()))) {
542       // Create a temporary file.
543       SmallString<128> TempPath;
544       TempPath = OutFile;
545       TempPath += "-%%%%%%%%";
546       int fd;
547       if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
548                                      /*makeAbsolute=*/false, 0664)
549           == llvm::errc::success) {
550         OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
551         OSFile = TempFile = TempPath.str();
552       }
553     }
554   }
555 
556   if (!OS) {
557     OSFile = OutFile;
558     OS.reset(
559       new llvm::raw_fd_ostream(OSFile.c_str(), Error,
560                                (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
561     if (!Error.empty())
562       return 0;
563   }
564 
565   // Make sure the out stream file gets removed if we crash.
566   if (RemoveFileOnSignal)
567     llvm::sys::RemoveFileOnSignal(llvm::sys::Path(OSFile));
568 
569   if (ResultPathName)
570     *ResultPathName = OutFile;
571   if (TempPathName)
572     *TempPathName = TempFile;
573 
574   return OS.take();
575 }
576 
577 // Initialization Utilities
578 
579 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
580   return InitializeSourceManager(Input, getDiagnostics(),
581                                  getFileManager(), getSourceManager(),
582                                  getFrontendOpts());
583 }
584 
585 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
586                                                DiagnosticsEngine &Diags,
587                                                FileManager &FileMgr,
588                                                SourceManager &SourceMgr,
589                                                const FrontendOptions &Opts) {
590   SrcMgr::CharacteristicKind
591     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
592 
593   if (Input.isBuffer()) {
594     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
595     assert(!SourceMgr.getMainFileID().isInvalid() &&
596            "Couldn't establish MainFileID!");
597     return true;
598   }
599 
600   StringRef InputFile = Input.getFile();
601 
602   // Figure out where to get and map in the main file.
603   if (InputFile != "-") {
604     const FileEntry *File = FileMgr.getFile(InputFile);
605     if (!File) {
606       Diags.Report(diag::err_fe_error_reading) << InputFile;
607       return false;
608     }
609 
610     // The natural SourceManager infrastructure can't currently handle named
611     // pipes, but we would at least like to accept them for the main
612     // file. Detect them here, read them with the more generic MemoryBuffer
613     // function, and simply override their contents as we do for STDIN.
614     if (File->isNamedPipe()) {
615       OwningPtr<llvm::MemoryBuffer> MB;
616       if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
617         Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
618         return false;
619       }
620 
621       // Create a new virtual file that will have the correct size.
622       File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
623       SourceMgr.overrideFileContents(File, MB.take());
624     }
625 
626     SourceMgr.createMainFileID(File, Kind);
627   } else {
628     OwningPtr<llvm::MemoryBuffer> SB;
629     if (llvm::MemoryBuffer::getSTDIN(SB)) {
630       // FIXME: Give ec.message() in this diag.
631       Diags.Report(diag::err_fe_error_reading_stdin);
632       return false;
633     }
634     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
635                                                    SB->getBufferSize(), 0);
636     SourceMgr.createMainFileID(File, Kind);
637     SourceMgr.overrideFileContents(File, SB.take());
638   }
639 
640   assert(!SourceMgr.getMainFileID().isInvalid() &&
641          "Couldn't establish MainFileID!");
642   return true;
643 }
644 
645 // High-Level Operations
646 
647 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
648   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
649   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
650   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
651 
652   // FIXME: Take this as an argument, once all the APIs we used have moved to
653   // taking it as an input instead of hard-coding llvm::errs.
654   raw_ostream &OS = llvm::errs();
655 
656   // Create the target instance.
657   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
658   if (!hasTarget())
659     return false;
660 
661   // Inform the target of the language options.
662   //
663   // FIXME: We shouldn't need to do this, the target should be immutable once
664   // created. This complexity should be lifted elsewhere.
665   getTarget().setForcedLangOptions(getLangOpts());
666 
667   // rewriter project will change target built-in bool type from its default.
668   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
669     getTarget().noSignedCharForObjCBool();
670 
671   // Validate/process some options.
672   if (getHeaderSearchOpts().Verbose)
673     OS << "clang -cc1 version " CLANG_VERSION_STRING
674        << " based upon " << PACKAGE_STRING
675        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
676 
677   if (getFrontendOpts().ShowTimers)
678     createFrontendTimer();
679 
680   if (getFrontendOpts().ShowStats)
681     llvm::EnableStatistics();
682 
683   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
684     // Reset the ID tables if we are reusing the SourceManager.
685     if (hasSourceManager())
686       getSourceManager().clearIDTables();
687 
688     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
689       Act.Execute();
690       Act.EndSourceFile();
691     }
692   }
693 
694   // Notify the diagnostic client that all files were processed.
695   getDiagnostics().getClient()->finish();
696 
697   if (getDiagnosticOpts().ShowCarets) {
698     // We can have multiple diagnostics sharing one diagnostic client.
699     // Get the total number of warnings/errors from the client.
700     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
701     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
702 
703     if (NumWarnings)
704       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
705     if (NumWarnings && NumErrors)
706       OS << " and ";
707     if (NumErrors)
708       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
709     if (NumWarnings || NumErrors)
710       OS << " generated.\n";
711   }
712 
713   if (getFrontendOpts().ShowStats && hasFileManager()) {
714     getFileManager().PrintStats();
715     OS << "\n";
716   }
717 
718   return !getDiagnostics().getClient()->getNumErrors();
719 }
720 
721 /// \brief Determine the appropriate source input kind based on language
722 /// options.
723 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
724   if (LangOpts.OpenCL)
725     return IK_OpenCL;
726   if (LangOpts.CUDA)
727     return IK_CUDA;
728   if (LangOpts.ObjC1)
729     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
730   return LangOpts.CPlusPlus? IK_CXX : IK_C;
731 }
732 
733 namespace {
734   struct CompileModuleMapData {
735     CompilerInstance &Instance;
736     GenerateModuleAction &CreateModuleAction;
737   };
738 }
739 
740 /// \brief Helper function that executes the module-generating action under
741 /// a crash recovery context.
742 static void doCompileMapModule(void *UserData) {
743   CompileModuleMapData &Data
744     = *reinterpret_cast<CompileModuleMapData *>(UserData);
745   Data.Instance.ExecuteAction(Data.CreateModuleAction);
746 }
747 
748 namespace {
749   /// \brief Function object that checks with the given macro definition should
750   /// be removed, because it is one of the ignored macros.
751   class RemoveIgnoredMacro {
752     const HeaderSearchOptions &HSOpts;
753 
754   public:
755     explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
756       : HSOpts(HSOpts) { }
757 
758     bool operator()(const std::pair<std::string, bool> &def) const {
759       StringRef MacroDef = def.first;
760       return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
761     }
762   };
763 }
764 
765 /// \brief Compile a module file for the given module, using the options
766 /// provided by the importing compiler instance.
767 static void compileModule(CompilerInstance &ImportingInstance,
768                           SourceLocation ImportLoc,
769                           Module *Module,
770                           StringRef ModuleFileName) {
771   llvm::LockFileManager Locked(ModuleFileName);
772   switch (Locked) {
773   case llvm::LockFileManager::LFS_Error:
774     return;
775 
776   case llvm::LockFileManager::LFS_Owned:
777     // We're responsible for building the module ourselves. Do so below.
778     break;
779 
780   case llvm::LockFileManager::LFS_Shared:
781     // Someone else is responsible for building the module. Wait for them to
782     // finish.
783     Locked.waitForUnlock();
784     return;
785   }
786 
787   ModuleMap &ModMap
788     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
789 
790   // Construct a compiler invocation for creating this module.
791   IntrusiveRefCntPtr<CompilerInvocation> Invocation
792     (new CompilerInvocation(ImportingInstance.getInvocation()));
793 
794   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
795 
796   // For any options that aren't intended to affect how a module is built,
797   // reset them to their default values.
798   Invocation->getLangOpts()->resetNonModularOptions();
799   PPOpts.resetNonModularOptions();
800 
801   // Remove any macro definitions that are explicitly ignored by the module.
802   // They aren't supposed to affect how the module is built anyway.
803   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
804   PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
805                                      RemoveIgnoredMacro(HSOpts)),
806                       PPOpts.Macros.end());
807 
808 
809   // Note the name of the module we're building.
810   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
811 
812   // Make sure that the failed-module structure has been allocated in
813   // the importing instance, and propagate the pointer to the newly-created
814   // instance.
815   PreprocessorOptions &ImportingPPOpts
816     = ImportingInstance.getInvocation().getPreprocessorOpts();
817   if (!ImportingPPOpts.FailedModules)
818     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
819   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
820 
821   // If there is a module map file, build the module using the module map.
822   // Set up the inputs/outputs so that we build the module from its umbrella
823   // header.
824   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
825   FrontendOpts.OutputFile = ModuleFileName.str();
826   FrontendOpts.DisableFree = false;
827   FrontendOpts.GenerateGlobalModuleIndex = false;
828   FrontendOpts.Inputs.clear();
829   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
830 
831   // Get or create the module map that we'll use to build this module.
832   SmallString<128> TempModuleMapFileName;
833   if (const FileEntry *ModuleMapFile
834                                   = ModMap.getContainingModuleMapFile(Module)) {
835     // Use the module map where this module resides.
836     FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
837                                                     IK));
838   } else {
839     // Create a temporary module map file.
840     TempModuleMapFileName = Module->Name;
841     TempModuleMapFileName += "-%%%%%%%%.map";
842     int FD;
843     if (llvm::sys::fs::unique_file(TempModuleMapFileName.str(), FD,
844                                    TempModuleMapFileName,
845                                    /*makeAbsolute=*/true)
846           != llvm::errc::success) {
847       ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
848         << TempModuleMapFileName;
849       return;
850     }
851     // Print the module map to this file.
852     llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
853     Module->print(OS);
854     FrontendOpts.Inputs.push_back(
855       FrontendInputFile(TempModuleMapFileName.str().str(), IK));
856   }
857 
858   // Don't free the remapped file buffers; they are owned by our caller.
859   PPOpts.RetainRemappedFileBuffers = true;
860 
861   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
862   assert(ImportingInstance.getInvocation().getModuleHash() ==
863          Invocation->getModuleHash() && "Module hash mismatch!");
864 
865   // Construct a compiler instance that will be used to actually create the
866   // module.
867   CompilerInstance Instance;
868   Instance.setInvocation(&*Invocation);
869   Instance.createDiagnostics(&ImportingInstance.getDiagnosticClient(),
870                              /*ShouldOwnClient=*/true,
871                              /*ShouldCloneClient=*/true);
872 
873   // Note that this module is part of the module build stack, so that we
874   // can detect cycles in the module graph.
875   Instance.createFileManager(); // FIXME: Adopt file manager from importer?
876   Instance.createSourceManager(Instance.getFileManager());
877   SourceManager &SourceMgr = Instance.getSourceManager();
878   SourceMgr.setModuleBuildStack(
879     ImportingInstance.getSourceManager().getModuleBuildStack());
880   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
881     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
882 
883 
884   // Construct a module-generating action.
885   GenerateModuleAction CreateModuleAction;
886 
887   // Execute the action to actually build the module in-place. Use a separate
888   // thread so that we get a stack large enough.
889   const unsigned ThreadStackSize = 8 << 20;
890   llvm::CrashRecoveryContext CRC;
891   CompileModuleMapData Data = { Instance, CreateModuleAction };
892   CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
893 
894   // Delete the temporary module map file.
895   // FIXME: Even though we're executing under crash protection, it would still
896   // be nice to do this with RemoveFileOnSignal when we can. However, that
897   // doesn't make sense for all clients, so clean this up manually.
898   Instance.clearOutputFiles(/*EraseFiles=*/true);
899   if (!TempModuleMapFileName.empty())
900     llvm::sys::Path(TempModuleMapFileName).eraseFromDisk();
901 
902   // We've rebuilt a module. If we're allowed to generate or update the global
903   // module index, record that fact in the importing compiler instance.
904   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
905     ImportingInstance.setBuildGlobalModuleIndex(true);
906   }
907 }
908 
909 /// \brief Diagnose differences between the current definition of the given
910 /// configuration macro and the definition provided on the command line.
911 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
912                              Module *Mod, SourceLocation ImportLoc) {
913   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
914   SourceManager &SourceMgr = PP.getSourceManager();
915 
916   // If this identifier has never had a macro definition, then it could
917   // not have changed.
918   if (!Id->hadMacroDefinition())
919     return;
920 
921   // If this identifier does not currently have a macro definition,
922   // check whether it had one on the command line.
923   if (!Id->hasMacroDefinition()) {
924     MacroDirective *UndefMD = PP.getMacroDirectiveHistory(Id);
925     for (MacroDirective *MD = UndefMD; MD; MD = MD->getPrevious()) {
926 
927       FileID FID = SourceMgr.getFileID(MD->getLocation());
928       if (FID.isInvalid())
929         continue;
930 
931       const llvm::MemoryBuffer *Buffer = SourceMgr.getBuffer(FID);
932       if (!Buffer)
933         continue;
934 
935       // We only care about the predefines buffer.
936       if (!StringRef(Buffer->getBufferIdentifier()).equals("<built-in>"))
937         continue;
938 
939       // This macro was defined on the command line, then #undef'd later.
940       // Complain.
941       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
942         << true << ConfigMacro << Mod->getFullModuleName();
943       if (UndefMD->getUndefLoc().isValid())
944         PP.Diag(UndefMD->getUndefLoc(), diag::note_module_def_undef_here)
945           << true;
946       return;
947     }
948 
949     // Okay: no definition in the predefines buffer.
950     return;
951   }
952 
953   // This identifier has a macro definition. Check whether we had a definition
954   // on the command line.
955   MacroDirective *DefMD = PP.getMacroDirective(Id);
956   MacroDirective *PredefinedMD = 0;
957   for (MacroDirective *MD = DefMD; MD; MD = MD->getPrevious()) {
958     FileID FID = SourceMgr.getFileID(MD->getLocation());
959     if (FID.isInvalid())
960       continue;
961 
962     const llvm::MemoryBuffer *Buffer = SourceMgr.getBuffer(FID);
963     if (!Buffer)
964       continue;
965 
966     // We only care about the predefines buffer.
967     if (!StringRef(Buffer->getBufferIdentifier()).equals("<built-in>"))
968       continue;
969 
970     PredefinedMD = MD;
971     break;
972   }
973 
974   // If there was no definition for this macro in the predefines buffer,
975   // complain.
976   if (!PredefinedMD ||
977       (!PredefinedMD->getLocation().isValid() &&
978        PredefinedMD->getUndefLoc().isValid())) {
979     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
980       << false << ConfigMacro << Mod->getFullModuleName();
981     PP.Diag(DefMD->getLocation(), diag::note_module_def_undef_here)
982       << false;
983     return;
984   }
985 
986   // If the current macro definition is the same as the predefined macro
987   // definition, it's okay.
988   if (DefMD == PredefinedMD ||
989       DefMD->getInfo()->isIdenticalTo(*PredefinedMD->getInfo(), PP))
990     return;
991 
992   // The macro definitions differ.
993   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
994     << false << ConfigMacro << Mod->getFullModuleName();
995   PP.Diag(DefMD->getLocation(), diag::note_module_def_undef_here)
996     << false;
997 }
998 
999 ModuleLoadResult
1000 CompilerInstance::loadModule(SourceLocation ImportLoc,
1001                              ModuleIdPath Path,
1002                              Module::NameVisibilityKind Visibility,
1003                              bool IsInclusionDirective) {
1004   // If we've already handled this import, just return the cached result.
1005   // This one-element cache is important to eliminate redundant diagnostics
1006   // when both the preprocessor and parser see the same import declaration.
1007   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1008     // Make the named module visible.
1009     if (LastModuleImportResult)
1010       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1011                                        ImportLoc, /*Complain=*/false);
1012     return LastModuleImportResult;
1013   }
1014 
1015   // Determine what file we're searching from.
1016   StringRef ModuleName = Path[0].first->getName();
1017   SourceLocation ModuleNameLoc = Path[0].second;
1018 
1019   clang::Module *Module = 0;
1020 
1021   // If we don't already have information on this module, load the module now.
1022   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1023     = KnownModules.find(Path[0].first);
1024   if (Known != KnownModules.end()) {
1025     // Retrieve the cached top-level module.
1026     Module = Known->second;
1027   } else if (ModuleName == getLangOpts().CurrentModule) {
1028     // This is the module we're building.
1029     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1030     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1031   } else {
1032     // Search for a module with the given name.
1033     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1034     std::string ModuleFileName;
1035     if (Module) {
1036       ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1037     } else
1038       ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1039 
1040     // If we don't already have an ASTReader, create one now.
1041     if (!ModuleManager) {
1042       if (!hasASTContext())
1043         createASTContext();
1044 
1045       std::string Sysroot = getHeaderSearchOpts().Sysroot;
1046       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1047       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1048                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1049                                     PPOpts.DisablePCHValidation,
1050                                     /*AllowASTWithCompilerErrors=*/false,
1051                                     getFrontendOpts().UseGlobalModuleIndex);
1052       if (hasASTConsumer()) {
1053         ModuleManager->setDeserializationListener(
1054           getASTConsumer().GetASTDeserializationListener());
1055         getASTContext().setASTMutationListener(
1056           getASTConsumer().GetASTMutationListener());
1057         getPreprocessor().setPPMutationListener(
1058           getASTConsumer().GetPPMutationListener());
1059       }
1060       OwningPtr<ExternalASTSource> Source;
1061       Source.reset(ModuleManager);
1062       getASTContext().setExternalSource(Source);
1063       if (hasSema())
1064         ModuleManager->InitializeSema(getSema());
1065       if (hasASTConsumer())
1066         ModuleManager->StartTranslationUnit(&getASTConsumer());
1067     }
1068 
1069     // Try to load the module file.
1070     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1071     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1072                                    ImportLoc, ARRFlags)) {
1073     case ASTReader::Success:
1074       break;
1075 
1076     case ASTReader::OutOfDate: {
1077       // The module file is out-of-date. Remove it, then rebuild it.
1078       bool Existed;
1079       llvm::sys::fs::remove(ModuleFileName, Existed);
1080     }
1081     // Fall through to build the module again.
1082 
1083     case ASTReader::Missing: {
1084       // The module file is (now) missing. Build it.
1085 
1086       // If we don't have a module, we don't know how to build the module file.
1087       // Complain and return.
1088       if (!Module) {
1089         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1090           << ModuleName
1091           << SourceRange(ImportLoc, ModuleNameLoc);
1092         ModuleBuildFailed = true;
1093         return ModuleLoadResult();
1094       }
1095 
1096       // Check whether there is a cycle in the module graph.
1097       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1098       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1099       for (; Pos != PosEnd; ++Pos) {
1100         if (Pos->first == ModuleName)
1101           break;
1102       }
1103 
1104       if (Pos != PosEnd) {
1105         SmallString<256> CyclePath;
1106         for (; Pos != PosEnd; ++Pos) {
1107           CyclePath += Pos->first;
1108           CyclePath += " -> ";
1109         }
1110         CyclePath += ModuleName;
1111 
1112         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1113           << ModuleName << CyclePath;
1114         return ModuleLoadResult();
1115       }
1116 
1117       // Check whether we have already attempted to build this module (but
1118       // failed).
1119       if (getPreprocessorOpts().FailedModules &&
1120           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1121         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1122           << ModuleName
1123           << SourceRange(ImportLoc, ModuleNameLoc);
1124         ModuleBuildFailed = true;
1125         return ModuleLoadResult();
1126       }
1127 
1128       // Try to compile the module.
1129       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1130 
1131       // Try to read the module file, now that we've compiled it.
1132       ASTReader::ASTReadResult ReadResult
1133         = ModuleManager->ReadAST(ModuleFileName,
1134                                  serialization::MK_Module, ImportLoc,
1135                                  ASTReader::ARR_Missing);
1136       if (ReadResult != ASTReader::Success) {
1137         if (ReadResult == ASTReader::Missing) {
1138           getDiagnostics().Report(ModuleNameLoc,
1139                                   Module? diag::err_module_not_built
1140                                         : diag::err_module_not_found)
1141             << ModuleName
1142             << SourceRange(ImportLoc, ModuleNameLoc);
1143         }
1144 
1145         if (getPreprocessorOpts().FailedModules)
1146           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1147         KnownModules[Path[0].first] = 0;
1148         ModuleBuildFailed = true;
1149         return ModuleLoadResult();
1150       }
1151 
1152       // Okay, we've rebuilt and now loaded the module.
1153       break;
1154     }
1155 
1156     case ASTReader::VersionMismatch:
1157     case ASTReader::ConfigurationMismatch:
1158     case ASTReader::HadErrors:
1159       // FIXME: The ASTReader will already have complained, but can we showhorn
1160       // that diagnostic information into a more useful form?
1161       KnownModules[Path[0].first] = 0;
1162       return ModuleLoadResult();
1163 
1164     case ASTReader::Failure:
1165       // Already complained, but note now that we failed.
1166       KnownModules[Path[0].first] = 0;
1167       ModuleBuildFailed = true;
1168       return ModuleLoadResult();
1169     }
1170 
1171     if (!Module) {
1172       // If we loaded the module directly, without finding a module map first,
1173       // we'll have loaded the module's information from the module itself.
1174       Module = PP->getHeaderSearchInfo().getModuleMap()
1175                  .findModule((Path[0].first->getName()));
1176     }
1177 
1178     // Cache the result of this top-level module lookup for later.
1179     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1180   }
1181 
1182   // If we never found the module, fail.
1183   if (!Module)
1184     return ModuleLoadResult();
1185 
1186   // Verify that the rest of the module path actually corresponds to
1187   // a submodule.
1188   if (Path.size() > 1) {
1189     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1190       StringRef Name = Path[I].first->getName();
1191       clang::Module *Sub = Module->findSubmodule(Name);
1192 
1193       if (!Sub) {
1194         // Attempt to perform typo correction to find a module name that works.
1195         SmallVector<StringRef, 2> Best;
1196         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1197 
1198         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1199                                             JEnd = Module->submodule_end();
1200              J != JEnd; ++J) {
1201           unsigned ED = Name.edit_distance((*J)->Name,
1202                                            /*AllowReplacements=*/true,
1203                                            BestEditDistance);
1204           if (ED <= BestEditDistance) {
1205             if (ED < BestEditDistance) {
1206               Best.clear();
1207               BestEditDistance = ED;
1208             }
1209 
1210             Best.push_back((*J)->Name);
1211           }
1212         }
1213 
1214         // If there was a clear winner, user it.
1215         if (Best.size() == 1) {
1216           getDiagnostics().Report(Path[I].second,
1217                                   diag::err_no_submodule_suggest)
1218             << Path[I].first << Module->getFullModuleName() << Best[0]
1219             << SourceRange(Path[0].second, Path[I-1].second)
1220             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1221                                             Best[0]);
1222 
1223           Sub = Module->findSubmodule(Best[0]);
1224         }
1225       }
1226 
1227       if (!Sub) {
1228         // No submodule by this name. Complain, and don't look for further
1229         // submodules.
1230         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1231           << Path[I].first << Module->getFullModuleName()
1232           << SourceRange(Path[0].second, Path[I-1].second);
1233         break;
1234       }
1235 
1236       Module = Sub;
1237     }
1238   }
1239 
1240   // Make the named module visible, if it's not already part of the module
1241   // we are parsing.
1242   if (ModuleName != getLangOpts().CurrentModule) {
1243     if (!Module->IsFromModuleFile) {
1244       // We have an umbrella header or directory that doesn't actually include
1245       // all of the headers within the directory it covers. Complain about
1246       // this missing submodule and recover by forgetting that we ever saw
1247       // this submodule.
1248       // FIXME: Should we detect this at module load time? It seems fairly
1249       // expensive (and rare).
1250       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1251         << Module->getFullModuleName()
1252         << SourceRange(Path.front().second, Path.back().second);
1253 
1254       return ModuleLoadResult(0, true);
1255     }
1256 
1257     // Check whether this module is available.
1258     StringRef Feature;
1259     if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1260       getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1261         << Module->getFullModuleName()
1262         << Feature
1263         << SourceRange(Path.front().second, Path.back().second);
1264       LastModuleImportLoc = ImportLoc;
1265       LastModuleImportResult = ModuleLoadResult();
1266       return ModuleLoadResult();
1267     }
1268 
1269     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1270                                      /*Complain=*/true);
1271   }
1272 
1273   // Check for any configuration macros that have changed.
1274   clang::Module *TopModule = Module->getTopLevelModule();
1275   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1276     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1277                      Module, ImportLoc);
1278   }
1279 
1280   // If this module import was due to an inclusion directive, create an
1281   // implicit import declaration to capture it in the AST.
1282   if (IsInclusionDirective && hasASTContext()) {
1283     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1284     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1285                                                      ImportLoc, Module,
1286                                                      Path.back().second);
1287     TU->addDecl(ImportD);
1288     if (Consumer)
1289       Consumer->HandleImplicitImportDecl(ImportD);
1290   }
1291 
1292   LastModuleImportLoc = ImportLoc;
1293   LastModuleImportResult = ModuleLoadResult(Module, false);
1294   return LastModuleImportResult;
1295 }
1296 
1297 void CompilerInstance::makeModuleVisible(Module *Mod,
1298                                          Module::NameVisibilityKind Visibility,
1299                                          SourceLocation ImportLoc,
1300                                          bool Complain){
1301   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1302 }
1303 
1304