xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision 9a16beb8bc580212df519aa488242a94e53741d8)
1 //===--- CompilerInstance.cpp ---------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/Frontend/CompilerInstance.h"
11 #include "clang/AST/ASTConsumer.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/AST/Decl.h"
14 #include "clang/Basic/Diagnostic.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Basic/Version.h"
19 #include "clang/Frontend/ChainedDiagnosticConsumer.h"
20 #include "clang/Frontend/FrontendAction.h"
21 #include "clang/Frontend/FrontendActions.h"
22 #include "clang/Frontend/FrontendDiagnostic.h"
23 #include "clang/Frontend/LogDiagnosticPrinter.h"
24 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
25 #include "clang/Frontend/TextDiagnosticPrinter.h"
26 #include "clang/Frontend/Utils.h"
27 #include "clang/Frontend/VerifyDiagnosticConsumer.h"
28 #include "clang/Lex/HeaderSearch.h"
29 #include "clang/Lex/PTHManager.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Sema/CodeCompleteConsumer.h"
32 #include "clang/Sema/Sema.h"
33 #include "clang/Serialization/ASTReader.h"
34 #include "llvm/ADT/Statistic.h"
35 #include "llvm/Config/config.h"
36 #include "llvm/Support/CrashRecoveryContext.h"
37 #include "llvm/Support/FileSystem.h"
38 #include "llvm/Support/Host.h"
39 #include "llvm/Support/LockFileManager.h"
40 #include "llvm/Support/MemoryBuffer.h"
41 #include "llvm/Support/Path.h"
42 #include "llvm/Support/Program.h"
43 #include "llvm/Support/Signals.h"
44 #include "llvm/Support/Timer.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Support/system_error.h"
47 #include <sys/stat.h>
48 #include <time.h>
49 
50 using namespace clang;
51 
52 CompilerInstance::CompilerInstance()
53   : Invocation(new CompilerInvocation()), ModuleManager(0),
54     BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
55 }
56 
57 CompilerInstance::~CompilerInstance() {
58   assert(OutputFiles.empty() && "Still output files in flight?");
59 }
60 
61 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
62   Invocation = Value;
63 }
64 
65 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
66   return (BuildGlobalModuleIndex ||
67           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
68            getFrontendOpts().GenerateGlobalModuleIndex)) &&
69          !ModuleBuildFailed;
70 }
71 
72 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
73   Diagnostics = Value;
74 }
75 
76 void CompilerInstance::setTarget(TargetInfo *Value) {
77   Target = Value;
78 }
79 
80 void CompilerInstance::setFileManager(FileManager *Value) {
81   FileMgr = Value;
82   if (Value)
83     VirtualFileSystem = Value->getVirtualFileSystem();
84   else
85     VirtualFileSystem.reset();
86 }
87 
88 void CompilerInstance::setSourceManager(SourceManager *Value) {
89   SourceMgr = Value;
90 }
91 
92 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
93 
94 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
95 
96 void CompilerInstance::setSema(Sema *S) {
97   TheSema.reset(S);
98 }
99 
100 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
101   Consumer.reset(Value);
102 }
103 
104 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
105   CompletionConsumer.reset(Value);
106 }
107 
108 IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
109   return ModuleManager;
110 }
111 void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
112   ModuleManager = Reader;
113 }
114 
115 // Diagnostics
116 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
117                                const CodeGenOptions *CodeGenOpts,
118                                DiagnosticsEngine &Diags) {
119   std::string ErrorInfo;
120   bool OwnsStream = false;
121   raw_ostream *OS = &llvm::errs();
122   if (DiagOpts->DiagnosticLogFile != "-") {
123     // Create the output stream.
124     llvm::raw_fd_ostream *FileOS(new llvm::raw_fd_ostream(
125         DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
126         llvm::sys::fs::F_Append | llvm::sys::fs::F_Text));
127     if (!ErrorInfo.empty()) {
128       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
129         << DiagOpts->DiagnosticLogFile << ErrorInfo;
130     } else {
131       FileOS->SetUnbuffered();
132       FileOS->SetUseAtomicWrites(true);
133       OS = FileOS;
134       OwnsStream = true;
135     }
136   }
137 
138   // Chain in the diagnostic client which will log the diagnostics.
139   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
140                                                           OwnsStream);
141   if (CodeGenOpts)
142     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
143   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
144 }
145 
146 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
147                                        DiagnosticsEngine &Diags,
148                                        StringRef OutputFile) {
149   std::string ErrorInfo;
150   OwningPtr<llvm::raw_fd_ostream> OS;
151   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
152                                     llvm::sys::fs::F_None));
153 
154   if (!ErrorInfo.empty()) {
155     Diags.Report(diag::warn_fe_serialized_diag_failure)
156       << OutputFile << ErrorInfo;
157     return;
158   }
159 
160   DiagnosticConsumer *SerializedConsumer =
161       clang::serialized_diags::create(OS.release(), DiagOpts);
162 
163   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
164                                                 SerializedConsumer));
165 }
166 
167 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
168                                          bool ShouldOwnClient) {
169   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
170                                   ShouldOwnClient, &getCodeGenOpts());
171 }
172 
173 IntrusiveRefCntPtr<DiagnosticsEngine>
174 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
175                                     DiagnosticConsumer *Client,
176                                     bool ShouldOwnClient,
177                                     const CodeGenOptions *CodeGenOpts) {
178   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
179   IntrusiveRefCntPtr<DiagnosticsEngine>
180       Diags(new DiagnosticsEngine(DiagID, Opts));
181 
182   // Create the diagnostic client for reporting errors or for
183   // implementing -verify.
184   if (Client) {
185     Diags->setClient(Client, ShouldOwnClient);
186   } else
187     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
188 
189   // Chain in -verify checker, if requested.
190   if (Opts->VerifyDiagnostics)
191     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
192 
193   // Chain in -diagnostic-log-file dumper, if requested.
194   if (!Opts->DiagnosticLogFile.empty())
195     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
196 
197   if (!Opts->DiagnosticSerializationFile.empty())
198     SetupSerializedDiagnostics(Opts, *Diags,
199                                Opts->DiagnosticSerializationFile);
200 
201   // Configure our handling of diagnostics.
202   ProcessWarningOptions(*Diags, *Opts);
203 
204   return Diags;
205 }
206 
207 // File Manager
208 
209 void CompilerInstance::createFileManager() {
210   if (!hasVirtualFileSystem()) {
211     // TODO: choose the virtual file system based on the CompilerInvocation.
212     setVirtualFileSystem(vfs::getRealFileSystem());
213   }
214   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
215 }
216 
217 // Source Manager
218 
219 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
220   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
221 }
222 
223 // Preprocessor
224 
225 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
226   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
227 
228   // Create a PTH manager if we are using some form of a token cache.
229   PTHManager *PTHMgr = 0;
230   if (!PPOpts.TokenCache.empty())
231     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
232 
233   // Create the Preprocessor.
234   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
235                                               getSourceManager(),
236                                               getDiagnostics(),
237                                               getLangOpts(),
238                                               &getTarget());
239   PP = new Preprocessor(&getPreprocessorOpts(),
240                         getDiagnostics(), getLangOpts(), &getTarget(),
241                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
242                         /*OwnsHeaderSearch=*/true,
243                         /*DelayInitialization=*/false,
244                         /*IncrProcessing=*/false,
245                         TUKind);
246 
247   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
248   // That argument is used as the IdentifierInfoLookup argument to
249   // IdentifierTable's ctor.
250   if (PTHMgr) {
251     PTHMgr->setPreprocessor(&*PP);
252     PP->setPTHManager(PTHMgr);
253   }
254 
255   if (PPOpts.DetailedRecord)
256     PP->createPreprocessingRecord();
257 
258   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
259 
260   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
261 
262   // Set up the module path, including the hash for the
263   // module-creation options.
264   SmallString<256> SpecificModuleCache(
265                            getHeaderSearchOpts().ModuleCachePath);
266   if (!getHeaderSearchOpts().DisableModuleHash)
267     llvm::sys::path::append(SpecificModuleCache,
268                             getInvocation().getModuleHash());
269   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
270 
271   // Handle generating dependencies, if requested.
272   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
273   if (!DepOpts.OutputFile.empty())
274     TheDependencyFileGenerator.reset(
275         DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
276   if (!DepOpts.DOTOutputFile.empty())
277     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
278                              getHeaderSearchOpts().Sysroot);
279 
280 
281   // Handle generating header include information, if requested.
282   if (DepOpts.ShowHeaderIncludes)
283     AttachHeaderIncludeGen(*PP);
284   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
285     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
286     if (OutputPath == "-")
287       OutputPath = "";
288     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
289                            /*ShowDepth=*/false);
290   }
291 
292   if (DepOpts.PrintShowIncludes) {
293     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
294                            /*ShowDepth=*/true, /*MSStyle=*/true);
295   }
296 }
297 
298 // ASTContext
299 
300 void CompilerInstance::createASTContext() {
301   Preprocessor &PP = getPreprocessor();
302   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
303                            &getTarget(), PP.getIdentifierTable(),
304                            PP.getSelectorTable(), PP.getBuiltinInfo(),
305                            /*size_reserve=*/ 0);
306 }
307 
308 // ExternalASTSource
309 
310 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
311                                                   bool DisablePCHValidation,
312                                                 bool AllowPCHWithCompilerErrors,
313                                                  void *DeserializationListener){
314   IntrusiveRefCntPtr<ExternalASTSource> Source;
315   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
316   Source = createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
317                                           DisablePCHValidation,
318                                           AllowPCHWithCompilerErrors,
319                                           getPreprocessor(), getASTContext(),
320                                           DeserializationListener,
321                                           Preamble,
322                                        getFrontendOpts().UseGlobalModuleIndex);
323   ModuleManager = static_cast<ASTReader*>(Source.getPtr());
324   getASTContext().setExternalSource(Source);
325 }
326 
327 ExternalASTSource *
328 CompilerInstance::createPCHExternalASTSource(StringRef Path,
329                                              const std::string &Sysroot,
330                                              bool DisablePCHValidation,
331                                              bool AllowPCHWithCompilerErrors,
332                                              Preprocessor &PP,
333                                              ASTContext &Context,
334                                              void *DeserializationListener,
335                                              bool Preamble,
336                                              bool UseGlobalModuleIndex) {
337   OwningPtr<ASTReader> Reader;
338   Reader.reset(new ASTReader(PP, Context,
339                              Sysroot.empty() ? "" : Sysroot.c_str(),
340                              DisablePCHValidation,
341                              AllowPCHWithCompilerErrors,
342                              /*AllowConfigurationMismatch*/false,
343                              /*ValidateSystemInputs*/false,
344                              UseGlobalModuleIndex));
345 
346   Reader->setDeserializationListener(
347             static_cast<ASTDeserializationListener *>(DeserializationListener));
348   switch (Reader->ReadAST(Path,
349                           Preamble ? serialization::MK_Preamble
350                                    : serialization::MK_PCH,
351                           SourceLocation(),
352                           ASTReader::ARR_None)) {
353   case ASTReader::Success:
354     // Set the predefines buffer as suggested by the PCH reader. Typically, the
355     // predefines buffer will be empty.
356     PP.setPredefines(Reader->getSuggestedPredefines());
357     return Reader.release();
358 
359   case ASTReader::Failure:
360     // Unrecoverable failure: don't even try to process the input file.
361     break;
362 
363   case ASTReader::Missing:
364   case ASTReader::OutOfDate:
365   case ASTReader::VersionMismatch:
366   case ASTReader::ConfigurationMismatch:
367   case ASTReader::HadErrors:
368     // No suitable PCH file could be found. Return an error.
369     break;
370   }
371 
372   return 0;
373 }
374 
375 // Code Completion
376 
377 static bool EnableCodeCompletion(Preprocessor &PP,
378                                  const std::string &Filename,
379                                  unsigned Line,
380                                  unsigned Column) {
381   // Tell the source manager to chop off the given file at a specific
382   // line and column.
383   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
384   if (!Entry) {
385     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
386       << Filename;
387     return true;
388   }
389 
390   // Truncate the named file at the given line/column.
391   PP.SetCodeCompletionPoint(Entry, Line, Column);
392   return false;
393 }
394 
395 void CompilerInstance::createCodeCompletionConsumer() {
396   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
397   if (!CompletionConsumer) {
398     setCodeCompletionConsumer(
399       createCodeCompletionConsumer(getPreprocessor(),
400                                    Loc.FileName, Loc.Line, Loc.Column,
401                                    getFrontendOpts().CodeCompleteOpts,
402                                    llvm::outs()));
403     if (!CompletionConsumer)
404       return;
405   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
406                                   Loc.Line, Loc.Column)) {
407     setCodeCompletionConsumer(0);
408     return;
409   }
410 
411   if (CompletionConsumer->isOutputBinary() &&
412       llvm::sys::ChangeStdoutToBinary()) {
413     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
414     setCodeCompletionConsumer(0);
415   }
416 }
417 
418 void CompilerInstance::createFrontendTimer() {
419   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
420 }
421 
422 CodeCompleteConsumer *
423 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
424                                                const std::string &Filename,
425                                                unsigned Line,
426                                                unsigned Column,
427                                                const CodeCompleteOptions &Opts,
428                                                raw_ostream &OS) {
429   if (EnableCodeCompletion(PP, Filename, Line, Column))
430     return 0;
431 
432   // Set up the creation routine for code-completion.
433   return new PrintingCodeCompleteConsumer(Opts, OS);
434 }
435 
436 void CompilerInstance::createSema(TranslationUnitKind TUKind,
437                                   CodeCompleteConsumer *CompletionConsumer) {
438   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
439                          TUKind, CompletionConsumer));
440 }
441 
442 // Output Files
443 
444 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
445   assert(OutFile.OS && "Attempt to add empty stream to output list!");
446   OutputFiles.push_back(OutFile);
447 }
448 
449 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
450   for (std::list<OutputFile>::iterator
451          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
452     delete it->OS;
453     if (!it->TempFilename.empty()) {
454       if (EraseFiles) {
455         llvm::sys::fs::remove(it->TempFilename);
456       } else {
457         SmallString<128> NewOutFile(it->Filename);
458 
459         // If '-working-directory' was passed, the output filename should be
460         // relative to that.
461         FileMgr->FixupRelativePath(NewOutFile);
462         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
463                                                         NewOutFile.str())) {
464           getDiagnostics().Report(diag::err_unable_to_rename_temp)
465             << it->TempFilename << it->Filename << ec.message();
466 
467           llvm::sys::fs::remove(it->TempFilename);
468         }
469       }
470     } else if (!it->Filename.empty() && EraseFiles)
471       llvm::sys::fs::remove(it->Filename);
472 
473   }
474   OutputFiles.clear();
475 }
476 
477 llvm::raw_fd_ostream *
478 CompilerInstance::createDefaultOutputFile(bool Binary,
479                                           StringRef InFile,
480                                           StringRef Extension) {
481   return createOutputFile(getFrontendOpts().OutputFile, Binary,
482                           /*RemoveFileOnSignal=*/true, InFile, Extension,
483                           /*UseTemporary=*/true);
484 }
485 
486 llvm::raw_fd_ostream *
487 CompilerInstance::createOutputFile(StringRef OutputPath,
488                                    bool Binary, bool RemoveFileOnSignal,
489                                    StringRef InFile,
490                                    StringRef Extension,
491                                    bool UseTemporary,
492                                    bool CreateMissingDirectories) {
493   std::string Error, OutputPathName, TempPathName;
494   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
495                                               RemoveFileOnSignal,
496                                               InFile, Extension,
497                                               UseTemporary,
498                                               CreateMissingDirectories,
499                                               &OutputPathName,
500                                               &TempPathName);
501   if (!OS) {
502     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
503       << OutputPath << Error;
504     return 0;
505   }
506 
507   // Add the output file -- but don't try to remove "-", since this means we are
508   // using stdin.
509   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
510                 TempPathName, OS));
511 
512   return OS;
513 }
514 
515 llvm::raw_fd_ostream *
516 CompilerInstance::createOutputFile(StringRef OutputPath,
517                                    std::string &Error,
518                                    bool Binary,
519                                    bool RemoveFileOnSignal,
520                                    StringRef InFile,
521                                    StringRef Extension,
522                                    bool UseTemporary,
523                                    bool CreateMissingDirectories,
524                                    std::string *ResultPathName,
525                                    std::string *TempPathName) {
526   assert((!CreateMissingDirectories || UseTemporary) &&
527          "CreateMissingDirectories is only allowed when using temporary files");
528 
529   std::string OutFile, TempFile;
530   if (!OutputPath.empty()) {
531     OutFile = OutputPath;
532   } else if (InFile == "-") {
533     OutFile = "-";
534   } else if (!Extension.empty()) {
535     SmallString<128> Path(InFile);
536     llvm::sys::path::replace_extension(Path, Extension);
537     OutFile = Path.str();
538   } else {
539     OutFile = "-";
540   }
541 
542   OwningPtr<llvm::raw_fd_ostream> OS;
543   std::string OSFile;
544 
545   if (UseTemporary) {
546     if (OutFile == "-")
547       UseTemporary = false;
548     else {
549       llvm::sys::fs::file_status Status;
550       llvm::sys::fs::status(OutputPath, Status);
551       if (llvm::sys::fs::exists(Status)) {
552         // Fail early if we can't write to the final destination.
553         if (!llvm::sys::fs::can_write(OutputPath))
554           return 0;
555 
556         // Don't use a temporary if the output is a special file. This handles
557         // things like '-o /dev/null'
558         if (!llvm::sys::fs::is_regular_file(Status))
559           UseTemporary = false;
560       }
561     }
562   }
563 
564   if (UseTemporary) {
565     // Create a temporary file.
566     SmallString<128> TempPath;
567     TempPath = OutFile;
568     TempPath += "-%%%%%%%%";
569     int fd;
570     llvm::error_code EC =
571         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
572 
573     if (CreateMissingDirectories &&
574         EC == llvm::errc::no_such_file_or_directory) {
575       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
576       EC = llvm::sys::fs::create_directories(Parent);
577       if (!EC) {
578         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
579       }
580     }
581 
582     if (!EC) {
583       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
584       OSFile = TempFile = TempPath.str();
585     }
586     // If we failed to create the temporary, fallback to writing to the file
587     // directly. This handles the corner case where we cannot write to the
588     // directory, but can write to the file.
589   }
590 
591   if (!OS) {
592     OSFile = OutFile;
593     OS.reset(new llvm::raw_fd_ostream(
594         OSFile.c_str(), Error,
595         (Binary ? llvm::sys::fs::F_None : llvm::sys::fs::F_Text)));
596     if (!Error.empty())
597       return 0;
598   }
599 
600   // Make sure the out stream file gets removed if we crash.
601   if (RemoveFileOnSignal)
602     llvm::sys::RemoveFileOnSignal(OSFile);
603 
604   if (ResultPathName)
605     *ResultPathName = OutFile;
606   if (TempPathName)
607     *TempPathName = TempFile;
608 
609   return OS.release();
610 }
611 
612 // Initialization Utilities
613 
614 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
615   return InitializeSourceManager(Input, getDiagnostics(),
616                                  getFileManager(), getSourceManager(),
617                                  getFrontendOpts());
618 }
619 
620 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
621                                                DiagnosticsEngine &Diags,
622                                                FileManager &FileMgr,
623                                                SourceManager &SourceMgr,
624                                                const FrontendOptions &Opts) {
625   SrcMgr::CharacteristicKind
626     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
627 
628   if (Input.isBuffer()) {
629     SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
630     assert(!SourceMgr.getMainFileID().isInvalid() &&
631            "Couldn't establish MainFileID!");
632     return true;
633   }
634 
635   StringRef InputFile = Input.getFile();
636 
637   // Figure out where to get and map in the main file.
638   if (InputFile != "-") {
639     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
640     if (!File) {
641       Diags.Report(diag::err_fe_error_reading) << InputFile;
642       return false;
643     }
644 
645     // The natural SourceManager infrastructure can't currently handle named
646     // pipes, but we would at least like to accept them for the main
647     // file. Detect them here, read them with the volatile flag so FileMgr will
648     // pick up the correct size, and simply override their contents as we do for
649     // STDIN.
650     if (File->isNamedPipe()) {
651       std::string ErrorStr;
652       if (llvm::MemoryBuffer *MB =
653               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
654         // Create a new virtual file that will have the correct size.
655         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
656         SourceMgr.overrideFileContents(File, MB);
657       } else {
658         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
659         return false;
660       }
661     }
662 
663     SourceMgr.createMainFileID(File, Kind);
664   } else {
665     OwningPtr<llvm::MemoryBuffer> SB;
666     if (llvm::error_code ec = llvm::MemoryBuffer::getSTDIN(SB)) {
667       Diags.Report(diag::err_fe_error_reading_stdin) << ec.message();
668       return false;
669     }
670     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
671                                                    SB->getBufferSize(), 0);
672     SourceMgr.createMainFileID(File, Kind);
673     SourceMgr.overrideFileContents(File, SB.release());
674   }
675 
676   assert(!SourceMgr.getMainFileID().isInvalid() &&
677          "Couldn't establish MainFileID!");
678   return true;
679 }
680 
681 // High-Level Operations
682 
683 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
684   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
685   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
686   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
687 
688   // FIXME: Take this as an argument, once all the APIs we used have moved to
689   // taking it as an input instead of hard-coding llvm::errs.
690   raw_ostream &OS = llvm::errs();
691 
692   // Create the target instance.
693   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
694   if (!hasTarget())
695     return false;
696 
697   // Inform the target of the language options.
698   //
699   // FIXME: We shouldn't need to do this, the target should be immutable once
700   // created. This complexity should be lifted elsewhere.
701   getTarget().setForcedLangOptions(getLangOpts());
702 
703   // rewriter project will change target built-in bool type from its default.
704   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
705     getTarget().noSignedCharForObjCBool();
706 
707   // Validate/process some options.
708   if (getHeaderSearchOpts().Verbose)
709     OS << "clang -cc1 version " CLANG_VERSION_STRING
710        << " based upon " << PACKAGE_STRING
711        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
712 
713   if (getFrontendOpts().ShowTimers)
714     createFrontendTimer();
715 
716   if (getFrontendOpts().ShowStats)
717     llvm::EnableStatistics();
718 
719   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
720     // Reset the ID tables if we are reusing the SourceManager.
721     if (hasSourceManager())
722       getSourceManager().clearIDTables();
723 
724     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
725       Act.Execute();
726       Act.EndSourceFile();
727     }
728   }
729 
730   // Notify the diagnostic client that all files were processed.
731   getDiagnostics().getClient()->finish();
732 
733   if (getDiagnosticOpts().ShowCarets) {
734     // We can have multiple diagnostics sharing one diagnostic client.
735     // Get the total number of warnings/errors from the client.
736     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
737     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
738 
739     if (NumWarnings)
740       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
741     if (NumWarnings && NumErrors)
742       OS << " and ";
743     if (NumErrors)
744       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
745     if (NumWarnings || NumErrors)
746       OS << " generated.\n";
747   }
748 
749   if (getFrontendOpts().ShowStats && hasFileManager()) {
750     getFileManager().PrintStats();
751     OS << "\n";
752   }
753 
754   return !getDiagnostics().getClient()->getNumErrors();
755 }
756 
757 /// \brief Determine the appropriate source input kind based on language
758 /// options.
759 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
760   if (LangOpts.OpenCL)
761     return IK_OpenCL;
762   if (LangOpts.CUDA)
763     return IK_CUDA;
764   if (LangOpts.ObjC1)
765     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
766   return LangOpts.CPlusPlus? IK_CXX : IK_C;
767 }
768 
769 /// \brief Compile a module file for the given module, using the options
770 /// provided by the importing compiler instance.
771 static void compileModule(CompilerInstance &ImportingInstance,
772                           SourceLocation ImportLoc,
773                           Module *Module,
774                           StringRef ModuleFileName) {
775   // FIXME: have LockFileManager return an error_code so that we can
776   // avoid the mkdir when the directory already exists.
777   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
778   llvm::sys::fs::create_directories(Dir);
779 
780   llvm::LockFileManager Locked(ModuleFileName);
781   switch (Locked) {
782   case llvm::LockFileManager::LFS_Error:
783     return;
784 
785   case llvm::LockFileManager::LFS_Owned:
786     // We're responsible for building the module ourselves. Do so below.
787     break;
788 
789   case llvm::LockFileManager::LFS_Shared:
790     // Someone else is responsible for building the module. Wait for them to
791     // finish.
792     Locked.waitForUnlock();
793     return;
794   }
795 
796   ModuleMap &ModMap
797     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
798 
799   // Construct a compiler invocation for creating this module.
800   IntrusiveRefCntPtr<CompilerInvocation> Invocation
801     (new CompilerInvocation(ImportingInstance.getInvocation()));
802 
803   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
804 
805   // For any options that aren't intended to affect how a module is built,
806   // reset them to their default values.
807   Invocation->getLangOpts()->resetNonModularOptions();
808   PPOpts.resetNonModularOptions();
809 
810   // Remove any macro definitions that are explicitly ignored by the module.
811   // They aren't supposed to affect how the module is built anyway.
812   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
813   PPOpts.Macros.erase(
814       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
815                      [&HSOpts](const std::pair<std::string, bool> &def) {
816         StringRef MacroDef = def.first;
817         return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
818       }),
819       PPOpts.Macros.end());
820 
821   // Note the name of the module we're building.
822   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
823 
824   // Make sure that the failed-module structure has been allocated in
825   // the importing instance, and propagate the pointer to the newly-created
826   // instance.
827   PreprocessorOptions &ImportingPPOpts
828     = ImportingInstance.getInvocation().getPreprocessorOpts();
829   if (!ImportingPPOpts.FailedModules)
830     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
831   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
832 
833   // If there is a module map file, build the module using the module map.
834   // Set up the inputs/outputs so that we build the module from its umbrella
835   // header.
836   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
837   FrontendOpts.OutputFile = ModuleFileName.str();
838   FrontendOpts.DisableFree = false;
839   FrontendOpts.GenerateGlobalModuleIndex = false;
840   FrontendOpts.Inputs.clear();
841   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
842 
843   // Don't free the remapped file buffers; they are owned by our caller.
844   PPOpts.RetainRemappedFileBuffers = true;
845 
846   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
847   assert(ImportingInstance.getInvocation().getModuleHash() ==
848          Invocation->getModuleHash() && "Module hash mismatch!");
849 
850   // Construct a compiler instance that will be used to actually create the
851   // module.
852   CompilerInstance Instance;
853   Instance.setInvocation(&*Invocation);
854 
855   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
856                                    ImportingInstance.getDiagnosticClient()),
857                              /*ShouldOwnClient=*/true);
858 
859   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
860 
861   // Note that this module is part of the module build stack, so that we
862   // can detect cycles in the module graph.
863   Instance.setFileManager(&ImportingInstance.getFileManager());
864   Instance.createSourceManager(Instance.getFileManager());
865   SourceManager &SourceMgr = Instance.getSourceManager();
866   SourceMgr.setModuleBuildStack(
867     ImportingInstance.getSourceManager().getModuleBuildStack());
868   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
869     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
870 
871   // Get or create the module map that we'll use to build this module.
872   std::string InferredModuleMapContent;
873   if (const FileEntry *ModuleMapFile =
874           ModMap.getContainingModuleMapFile(Module)) {
875     // Use the module map where this module resides.
876     FrontendOpts.Inputs.push_back(
877         FrontendInputFile(ModuleMapFile->getName(), IK));
878   } else {
879     llvm::raw_string_ostream OS(InferredModuleMapContent);
880     Module->print(OS);
881     OS.flush();
882     FrontendOpts.Inputs.push_back(
883         FrontendInputFile("__inferred_module.map", IK));
884 
885     const llvm::MemoryBuffer *ModuleMapBuffer =
886         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
887     ModuleMapFile = Instance.getFileManager().getVirtualFile(
888         "__inferred_module.map", InferredModuleMapContent.size(), 0);
889     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
890   }
891 
892   // Construct a module-generating action.
893   GenerateModuleAction CreateModuleAction(Module->IsSystem);
894 
895   // Execute the action to actually build the module in-place. Use a separate
896   // thread so that we get a stack large enough.
897   const unsigned ThreadStackSize = 8 << 20;
898   llvm::CrashRecoveryContext CRC;
899   CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
900                         ThreadStackSize);
901 
902   // Delete the temporary module map file.
903   // FIXME: Even though we're executing under crash protection, it would still
904   // be nice to do this with RemoveFileOnSignal when we can. However, that
905   // doesn't make sense for all clients, so clean this up manually.
906   Instance.clearOutputFiles(/*EraseFiles=*/true);
907 
908   // We've rebuilt a module. If we're allowed to generate or update the global
909   // module index, record that fact in the importing compiler instance.
910   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
911     ImportingInstance.setBuildGlobalModuleIndex(true);
912   }
913 }
914 
915 /// \brief Diagnose differences between the current definition of the given
916 /// configuration macro and the definition provided on the command line.
917 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
918                              Module *Mod, SourceLocation ImportLoc) {
919   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
920   SourceManager &SourceMgr = PP.getSourceManager();
921 
922   // If this identifier has never had a macro definition, then it could
923   // not have changed.
924   if (!Id->hadMacroDefinition())
925     return;
926 
927   // If this identifier does not currently have a macro definition,
928   // check whether it had one on the command line.
929   if (!Id->hasMacroDefinition()) {
930     MacroDirective::DefInfo LatestDef =
931         PP.getMacroDirectiveHistory(Id)->getDefinition();
932     for (MacroDirective::DefInfo Def = LatestDef; Def;
933            Def = Def.getPreviousDefinition()) {
934       FileID FID = SourceMgr.getFileID(Def.getLocation());
935       if (FID.isInvalid())
936         continue;
937 
938       // We only care about the predefines buffer.
939       if (FID != PP.getPredefinesFileID())
940         continue;
941 
942       // This macro was defined on the command line, then #undef'd later.
943       // Complain.
944       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
945         << true << ConfigMacro << Mod->getFullModuleName();
946       if (LatestDef.isUndefined())
947         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
948           << true;
949       return;
950     }
951 
952     // Okay: no definition in the predefines buffer.
953     return;
954   }
955 
956   // This identifier has a macro definition. Check whether we had a definition
957   // on the command line.
958   MacroDirective::DefInfo LatestDef =
959       PP.getMacroDirectiveHistory(Id)->getDefinition();
960   MacroDirective::DefInfo PredefinedDef;
961   for (MacroDirective::DefInfo Def = LatestDef; Def;
962          Def = Def.getPreviousDefinition()) {
963     FileID FID = SourceMgr.getFileID(Def.getLocation());
964     if (FID.isInvalid())
965       continue;
966 
967     // We only care about the predefines buffer.
968     if (FID != PP.getPredefinesFileID())
969       continue;
970 
971     PredefinedDef = Def;
972     break;
973   }
974 
975   // If there was no definition for this macro in the predefines buffer,
976   // complain.
977   if (!PredefinedDef ||
978       (!PredefinedDef.getLocation().isValid() &&
979        PredefinedDef.getUndefLocation().isValid())) {
980     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
981       << false << ConfigMacro << Mod->getFullModuleName();
982     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
983       << false;
984     return;
985   }
986 
987   // If the current macro definition is the same as the predefined macro
988   // definition, it's okay.
989   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
990       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
991                                               /*Syntactically=*/true))
992     return;
993 
994   // The macro definitions differ.
995   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
996     << false << ConfigMacro << Mod->getFullModuleName();
997   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
998     << false;
999 }
1000 
1001 /// \brief Write a new timestamp file with the given path.
1002 static void writeTimestampFile(StringRef TimestampFile) {
1003   std::string ErrorInfo;
1004   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1005                            llvm::sys::fs::F_None);
1006 }
1007 
1008 /// \brief Prune the module cache of modules that haven't been accessed in
1009 /// a long time.
1010 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1011   struct stat StatBuf;
1012   llvm::SmallString<128> TimestampFile;
1013   TimestampFile = HSOpts.ModuleCachePath;
1014   llvm::sys::path::append(TimestampFile, "modules.timestamp");
1015 
1016   // Try to stat() the timestamp file.
1017   if (::stat(TimestampFile.c_str(), &StatBuf)) {
1018     // If the timestamp file wasn't there, create one now.
1019     if (errno == ENOENT) {
1020       writeTimestampFile(TimestampFile);
1021     }
1022     return;
1023   }
1024 
1025   // Check whether the time stamp is older than our pruning interval.
1026   // If not, do nothing.
1027   time_t TimeStampModTime = StatBuf.st_mtime;
1028   time_t CurrentTime = time(0);
1029   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1030     return;
1031 
1032   // Write a new timestamp file so that nobody else attempts to prune.
1033   // There is a benign race condition here, if two Clang instances happen to
1034   // notice at the same time that the timestamp is out-of-date.
1035   writeTimestampFile(TimestampFile);
1036 
1037   // Walk the entire module cache, looking for unused module files and module
1038   // indices.
1039   llvm::error_code EC;
1040   SmallString<128> ModuleCachePathNative;
1041   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1042   for (llvm::sys::fs::directory_iterator
1043          Dir(ModuleCachePathNative.str(), EC), DirEnd;
1044        Dir != DirEnd && !EC; Dir.increment(EC)) {
1045     // If we don't have a directory, there's nothing to look into.
1046     if (!llvm::sys::fs::is_directory(Dir->path()))
1047       continue;
1048 
1049     // Walk all of the files within this directory.
1050     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1051          File != FileEnd && !EC; File.increment(EC)) {
1052       // We only care about module and global module index files.
1053       StringRef Extension = llvm::sys::path::extension(File->path());
1054       if (Extension != ".pcm" && Extension != ".timestamp" &&
1055           llvm::sys::path::filename(File->path()) != "modules.idx")
1056         continue;
1057 
1058       // Look at this file. If we can't stat it, there's nothing interesting
1059       // there.
1060       if (::stat(File->path().c_str(), &StatBuf))
1061         continue;
1062 
1063       // If the file has been used recently enough, leave it there.
1064       time_t FileAccessTime = StatBuf.st_atime;
1065       if (CurrentTime - FileAccessTime <=
1066               time_t(HSOpts.ModuleCachePruneAfter)) {
1067         continue;
1068       }
1069 
1070       // Remove the file.
1071       llvm::sys::fs::remove(File->path());
1072 
1073       // Remove the timestamp file.
1074       std::string TimpestampFilename = File->path() + ".timestamp";
1075       llvm::sys::fs::remove(TimpestampFilename);
1076     }
1077 
1078     // If we removed all of the files in the directory, remove the directory
1079     // itself.
1080     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1081             llvm::sys::fs::directory_iterator() && !EC)
1082       llvm::sys::fs::remove(Dir->path());
1083   }
1084 }
1085 
1086 ModuleLoadResult
1087 CompilerInstance::loadModule(SourceLocation ImportLoc,
1088                              ModuleIdPath Path,
1089                              Module::NameVisibilityKind Visibility,
1090                              bool IsInclusionDirective) {
1091   // Determine what file we're searching from.
1092   StringRef ModuleName = Path[0].first->getName();
1093   SourceLocation ModuleNameLoc = Path[0].second;
1094 
1095   // If we've already handled this import, just return the cached result.
1096   // This one-element cache is important to eliminate redundant diagnostics
1097   // when both the preprocessor and parser see the same import declaration.
1098   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1099     // Make the named module visible.
1100     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1101       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1102                                        ImportLoc, /*Complain=*/false);
1103     return LastModuleImportResult;
1104   }
1105 
1106   clang::Module *Module = 0;
1107 
1108   // If we don't already have information on this module, load the module now.
1109   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1110     = KnownModules.find(Path[0].first);
1111   if (Known != KnownModules.end()) {
1112     // Retrieve the cached top-level module.
1113     Module = Known->second;
1114   } else if (ModuleName == getLangOpts().CurrentModule) {
1115     // This is the module we're building.
1116     Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1117     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1118   } else {
1119     // Search for a module with the given name.
1120     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1121     if (!Module) {
1122       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1123       << ModuleName
1124       << SourceRange(ImportLoc, ModuleNameLoc);
1125       ModuleBuildFailed = true;
1126       return ModuleLoadResult();
1127     }
1128 
1129     std::string ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1130 
1131     // If we don't already have an ASTReader, create one now.
1132     if (!ModuleManager) {
1133       if (!hasASTContext())
1134         createASTContext();
1135 
1136       // If we're not recursively building a module, check whether we
1137       // need to prune the module cache.
1138       if (getSourceManager().getModuleBuildStack().empty() &&
1139           getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1140           getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1141         pruneModuleCache(getHeaderSearchOpts());
1142       }
1143 
1144       std::string Sysroot = getHeaderSearchOpts().Sysroot;
1145       const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1146       ModuleManager = new ASTReader(getPreprocessor(), *Context,
1147                                     Sysroot.empty() ? "" : Sysroot.c_str(),
1148                                     PPOpts.DisablePCHValidation,
1149                                     /*AllowASTWithCompilerErrors=*/false,
1150                                     /*AllowConfigurationMismatch=*/false,
1151                                     /*ValidateSystemInputs=*/false,
1152                                     getFrontendOpts().UseGlobalModuleIndex);
1153       if (hasASTConsumer()) {
1154         ModuleManager->setDeserializationListener(
1155           getASTConsumer().GetASTDeserializationListener());
1156         getASTContext().setASTMutationListener(
1157           getASTConsumer().GetASTMutationListener());
1158       }
1159       getASTContext().setExternalSource(ModuleManager);
1160       if (hasSema())
1161         ModuleManager->InitializeSema(getSema());
1162       if (hasASTConsumer())
1163         ModuleManager->StartTranslationUnit(&getASTConsumer());
1164     }
1165 
1166     if (TheDependencyFileGenerator)
1167       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
1168 
1169     // Try to load the module file.
1170     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1171     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1172                                    ImportLoc, ARRFlags)) {
1173     case ASTReader::Success:
1174       break;
1175 
1176     case ASTReader::OutOfDate:
1177     case ASTReader::Missing: {
1178       // The module file is missing or out-of-date. Build it.
1179       assert(Module && "missing module file");
1180       // Check whether there is a cycle in the module graph.
1181       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1182       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1183       for (; Pos != PosEnd; ++Pos) {
1184         if (Pos->first == ModuleName)
1185           break;
1186       }
1187 
1188       if (Pos != PosEnd) {
1189         SmallString<256> CyclePath;
1190         for (; Pos != PosEnd; ++Pos) {
1191           CyclePath += Pos->first;
1192           CyclePath += " -> ";
1193         }
1194         CyclePath += ModuleName;
1195 
1196         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1197           << ModuleName << CyclePath;
1198         return ModuleLoadResult();
1199       }
1200 
1201       // Check whether we have already attempted to build this module (but
1202       // failed).
1203       if (getPreprocessorOpts().FailedModules &&
1204           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1205         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1206           << ModuleName
1207           << SourceRange(ImportLoc, ModuleNameLoc);
1208         ModuleBuildFailed = true;
1209         return ModuleLoadResult();
1210       }
1211 
1212       // Try to compile the module.
1213       compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1214 
1215       // Try to read the module file, now that we've compiled it.
1216       ASTReader::ASTReadResult ReadResult
1217         = ModuleManager->ReadAST(ModuleFileName,
1218                                  serialization::MK_Module, ImportLoc,
1219                                  ASTReader::ARR_Missing);
1220       if (ReadResult != ASTReader::Success) {
1221         if (ReadResult == ASTReader::Missing) {
1222           getDiagnostics().Report(ModuleNameLoc,
1223                                   Module? diag::err_module_not_built
1224                                         : diag::err_module_not_found)
1225             << ModuleName
1226             << SourceRange(ImportLoc, ModuleNameLoc);
1227         }
1228 
1229         if (getPreprocessorOpts().FailedModules)
1230           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1231         KnownModules[Path[0].first] = 0;
1232         ModuleBuildFailed = true;
1233         return ModuleLoadResult();
1234       }
1235 
1236       // Okay, we've rebuilt and now loaded the module.
1237       break;
1238     }
1239 
1240     case ASTReader::VersionMismatch:
1241     case ASTReader::ConfigurationMismatch:
1242     case ASTReader::HadErrors:
1243       ModuleLoader::HadFatalFailure = true;
1244       // FIXME: The ASTReader will already have complained, but can we showhorn
1245       // that diagnostic information into a more useful form?
1246       KnownModules[Path[0].first] = 0;
1247       return ModuleLoadResult();
1248 
1249     case ASTReader::Failure:
1250       ModuleLoader::HadFatalFailure = true;
1251       // Already complained, but note now that we failed.
1252       KnownModules[Path[0].first] = 0;
1253       ModuleBuildFailed = true;
1254       return ModuleLoadResult();
1255     }
1256 
1257     // Cache the result of this top-level module lookup for later.
1258     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1259   }
1260 
1261   // If we never found the module, fail.
1262   if (!Module)
1263     return ModuleLoadResult();
1264 
1265   // Verify that the rest of the module path actually corresponds to
1266   // a submodule.
1267   if (Path.size() > 1) {
1268     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1269       StringRef Name = Path[I].first->getName();
1270       clang::Module *Sub = Module->findSubmodule(Name);
1271 
1272       if (!Sub) {
1273         // Attempt to perform typo correction to find a module name that works.
1274         SmallVector<StringRef, 2> Best;
1275         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1276 
1277         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1278                                             JEnd = Module->submodule_end();
1279              J != JEnd; ++J) {
1280           unsigned ED = Name.edit_distance((*J)->Name,
1281                                            /*AllowReplacements=*/true,
1282                                            BestEditDistance);
1283           if (ED <= BestEditDistance) {
1284             if (ED < BestEditDistance) {
1285               Best.clear();
1286               BestEditDistance = ED;
1287             }
1288 
1289             Best.push_back((*J)->Name);
1290           }
1291         }
1292 
1293         // If there was a clear winner, user it.
1294         if (Best.size() == 1) {
1295           getDiagnostics().Report(Path[I].second,
1296                                   diag::err_no_submodule_suggest)
1297             << Path[I].first << Module->getFullModuleName() << Best[0]
1298             << SourceRange(Path[0].second, Path[I-1].second)
1299             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1300                                             Best[0]);
1301 
1302           Sub = Module->findSubmodule(Best[0]);
1303         }
1304       }
1305 
1306       if (!Sub) {
1307         // No submodule by this name. Complain, and don't look for further
1308         // submodules.
1309         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1310           << Path[I].first << Module->getFullModuleName()
1311           << SourceRange(Path[0].second, Path[I-1].second);
1312         break;
1313       }
1314 
1315       Module = Sub;
1316     }
1317   }
1318 
1319   // Make the named module visible, if it's not already part of the module
1320   // we are parsing.
1321   if (ModuleName != getLangOpts().CurrentModule) {
1322     if (!Module->IsFromModuleFile) {
1323       // We have an umbrella header or directory that doesn't actually include
1324       // all of the headers within the directory it covers. Complain about
1325       // this missing submodule and recover by forgetting that we ever saw
1326       // this submodule.
1327       // FIXME: Should we detect this at module load time? It seems fairly
1328       // expensive (and rare).
1329       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1330         << Module->getFullModuleName()
1331         << SourceRange(Path.front().second, Path.back().second);
1332 
1333       return ModuleLoadResult(0, true);
1334     }
1335 
1336     // Check whether this module is available.
1337     clang::Module::Requirement Requirement;
1338     clang::Module::HeaderDirective MissingHeader;
1339     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
1340                              MissingHeader)) {
1341       if (MissingHeader.FileNameLoc.isValid()) {
1342         getDiagnostics().Report(MissingHeader.FileNameLoc,
1343                                 diag::err_module_header_missing)
1344           << MissingHeader.IsUmbrella << MissingHeader.FileName;
1345       } else {
1346         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1347           << Module->getFullModuleName()
1348           << Requirement.second << Requirement.first
1349           << SourceRange(Path.front().second, Path.back().second);
1350       }
1351       LastModuleImportLoc = ImportLoc;
1352       LastModuleImportResult = ModuleLoadResult();
1353       return ModuleLoadResult();
1354     }
1355 
1356     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1357                                      /*Complain=*/true);
1358   }
1359 
1360   // Check for any configuration macros that have changed.
1361   clang::Module *TopModule = Module->getTopLevelModule();
1362   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1363     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1364                      Module, ImportLoc);
1365   }
1366 
1367   // If this module import was due to an inclusion directive, create an
1368   // implicit import declaration to capture it in the AST.
1369   if (IsInclusionDirective && hasASTContext()) {
1370     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1371     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1372                                                      ImportLoc, Module,
1373                                                      Path.back().second);
1374     TU->addDecl(ImportD);
1375     if (Consumer)
1376       Consumer->HandleImplicitImportDecl(ImportD);
1377   }
1378 
1379   LastModuleImportLoc = ImportLoc;
1380   LastModuleImportResult = ModuleLoadResult(Module, false);
1381   return LastModuleImportResult;
1382 }
1383 
1384 void CompilerInstance::makeModuleVisible(Module *Mod,
1385                                          Module::NameVisibilityKind Visibility,
1386                                          SourceLocation ImportLoc,
1387                                          bool Complain){
1388   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1389 }
1390 
1391