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      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/Config/config.h"
     20 #include "clang/Frontend/ChainedDiagnosticConsumer.h"
     21 #include "clang/Frontend/FrontendAction.h"
     22 #include "clang/Frontend/FrontendActions.h"
     23 #include "clang/Frontend/FrontendDiagnostic.h"
     24 #include "clang/Frontend/LogDiagnosticPrinter.h"
     25 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
     26 #include "clang/Frontend/TextDiagnosticPrinter.h"
     27 #include "clang/Frontend/Utils.h"
     28 #include "clang/Frontend/VerifyDiagnosticConsumer.h"
     29 #include "clang/Lex/HeaderSearch.h"
     30 #include "clang/Lex/PTHManager.h"
     31 #include "clang/Lex/Preprocessor.h"
     32 #include "clang/Sema/CodeCompleteConsumer.h"
     33 #include "clang/Sema/Sema.h"
     34 #include "clang/Serialization/ASTReader.h"
     35 #include "clang/Serialization/GlobalModuleIndex.h"
     36 #include "llvm/ADT/Statistic.h"
     37 #include "llvm/Support/CrashRecoveryContext.h"
     38 #include "llvm/Support/Errc.h"
     39 #include "llvm/Support/FileSystem.h"
     40 #include "llvm/Support/Host.h"
     41 #include "llvm/Support/LockFileManager.h"
     42 #include "llvm/Support/MemoryBuffer.h"
     43 #include "llvm/Support/Path.h"
     44 #include "llvm/Support/Program.h"
     45 #include "llvm/Support/Signals.h"
     46 #include "llvm/Support/Timer.h"
     47 #include "llvm/Support/raw_ostream.h"
     48 #include <sys/stat.h>
     49 #include <system_error>
     50 #include <time.h>
     51 
     52 using namespace clang;
     53 
     54 CompilerInstance::CompilerInstance(bool BuildingModule)
     55   : ModuleLoader(BuildingModule),
     56     Invocation(new CompilerInvocation()), ModuleManager(nullptr),
     57     BuildGlobalModuleIndex(false), HaveFullGlobalModuleIndex(false),
     58     ModuleBuildFailed(false) {
     59 }
     60 
     61 CompilerInstance::~CompilerInstance() {
     62   assert(OutputFiles.empty() && "Still output files in flight?");
     63 }
     64 
     65 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
     66   Invocation = Value;
     67 }
     68 
     69 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
     70   return (BuildGlobalModuleIndex ||
     71           (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
     72            getFrontendOpts().GenerateGlobalModuleIndex)) &&
     73          !ModuleBuildFailed;
     74 }
     75 
     76 void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
     77   Diagnostics = Value;
     78 }
     79 
     80 void CompilerInstance::setTarget(TargetInfo *Value) {
     81   Target = Value;
     82 }
     83 
     84 void CompilerInstance::setFileManager(FileManager *Value) {
     85   FileMgr = Value;
     86   if (Value)
     87     VirtualFileSystem = Value->getVirtualFileSystem();
     88   else
     89     VirtualFileSystem.reset();
     90 }
     91 
     92 void CompilerInstance::setSourceManager(SourceManager *Value) {
     93   SourceMgr = Value;
     94 }
     95 
     96 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
     97 
     98 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
     99 
    100 void CompilerInstance::setSema(Sema *S) {
    101   TheSema.reset(S);
    102 }
    103 
    104 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
    105   Consumer.reset(Value);
    106 }
    107 
    108 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
    109   CompletionConsumer.reset(Value);
    110 }
    111 
    112 IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
    113   return ModuleManager;
    114 }
    115 void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
    116   ModuleManager = Reader;
    117 }
    118 
    119 std::shared_ptr<ModuleDependencyCollector>
    120 CompilerInstance::getModuleDepCollector() const {
    121   return ModuleDepCollector;
    122 }
    123 
    124 void CompilerInstance::setModuleDepCollector(
    125     std::shared_ptr<ModuleDependencyCollector> Collector) {
    126   ModuleDepCollector = Collector;
    127 }
    128 
    129 // Diagnostics
    130 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
    131                                const CodeGenOptions *CodeGenOpts,
    132                                DiagnosticsEngine &Diags) {
    133   std::string ErrorInfo;
    134   bool OwnsStream = false;
    135   raw_ostream *OS = &llvm::errs();
    136   if (DiagOpts->DiagnosticLogFile != "-") {
    137     // Create the output stream.
    138     llvm::raw_fd_ostream *FileOS(new llvm::raw_fd_ostream(
    139         DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
    140         llvm::sys::fs::F_Append | llvm::sys::fs::F_Text));
    141     if (!ErrorInfo.empty()) {
    142       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
    143         << DiagOpts->DiagnosticLogFile << ErrorInfo;
    144     } else {
    145       FileOS->SetUnbuffered();
    146       FileOS->SetUseAtomicWrites(true);
    147       OS = FileOS;
    148       OwnsStream = true;
    149     }
    150   }
    151 
    152   // Chain in the diagnostic client which will log the diagnostics.
    153   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
    154                                                           OwnsStream);
    155   if (CodeGenOpts)
    156     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
    157   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
    158 }
    159 
    160 static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
    161                                        DiagnosticsEngine &Diags,
    162                                        StringRef OutputFile) {
    163   std::string ErrorInfo;
    164   std::unique_ptr<llvm::raw_fd_ostream> OS;
    165   OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
    166                                     llvm::sys::fs::F_None));
    167 
    168   if (!ErrorInfo.empty()) {
    169     Diags.Report(diag::warn_fe_serialized_diag_failure)
    170       << OutputFile << ErrorInfo;
    171     return;
    172   }
    173 
    174   DiagnosticConsumer *SerializedConsumer =
    175       clang::serialized_diags::create(OS.release(), DiagOpts);
    176 
    177   Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
    178                                                 SerializedConsumer));
    179 }
    180 
    181 void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
    182                                          bool ShouldOwnClient) {
    183   Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
    184                                   ShouldOwnClient, &getCodeGenOpts());
    185 }
    186 
    187 IntrusiveRefCntPtr<DiagnosticsEngine>
    188 CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
    189                                     DiagnosticConsumer *Client,
    190                                     bool ShouldOwnClient,
    191                                     const CodeGenOptions *CodeGenOpts) {
    192   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
    193   IntrusiveRefCntPtr<DiagnosticsEngine>
    194       Diags(new DiagnosticsEngine(DiagID, Opts));
    195 
    196   // Create the diagnostic client for reporting errors or for
    197   // implementing -verify.
    198   if (Client) {
    199     Diags->setClient(Client, ShouldOwnClient);
    200   } else
    201     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
    202 
    203   // Chain in -verify checker, if requested.
    204   if (Opts->VerifyDiagnostics)
    205     Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
    206 
    207   // Chain in -diagnostic-log-file dumper, if requested.
    208   if (!Opts->DiagnosticLogFile.empty())
    209     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
    210 
    211   if (!Opts->DiagnosticSerializationFile.empty())
    212     SetupSerializedDiagnostics(Opts, *Diags,
    213                                Opts->DiagnosticSerializationFile);
    214 
    215   // Configure our handling of diagnostics.
    216   ProcessWarningOptions(*Diags, *Opts);
    217 
    218   return Diags;
    219 }
    220 
    221 // File Manager
    222 
    223 void CompilerInstance::createFileManager() {
    224   if (!hasVirtualFileSystem()) {
    225     // TODO: choose the virtual file system based on the CompilerInvocation.
    226     setVirtualFileSystem(vfs::getRealFileSystem());
    227   }
    228   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
    229 }
    230 
    231 // Source Manager
    232 
    233 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
    234   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
    235 }
    236 
    237 // Initialize the remapping of files to alternative contents, e.g.,
    238 // those specified through other files.
    239 static void InitializeFileRemapping(DiagnosticsEngine &Diags,
    240                                     SourceManager &SourceMgr,
    241                                     FileManager &FileMgr,
    242                                     const PreprocessorOptions &InitOpts) {
    243   // Remap files in the source manager (with buffers).
    244   for (const auto &RB : InitOpts.RemappedFileBuffers) {
    245     // Create the file entry for the file that we're mapping from.
    246     const FileEntry *FromFile =
    247         FileMgr.getVirtualFile(RB.first, RB.second->getBufferSize(), 0);
    248     if (!FromFile) {
    249       Diags.Report(diag::err_fe_remap_missing_from_file) << RB.first;
    250       if (!InitOpts.RetainRemappedFileBuffers)
    251         delete RB.second;
    252       continue;
    253     }
    254 
    255     // Override the contents of the "from" file with the contents of
    256     // the "to" file.
    257     SourceMgr.overrideFileContents(FromFile, RB.second,
    258                                    InitOpts.RetainRemappedFileBuffers);
    259   }
    260 
    261   // Remap files in the source manager (with other files).
    262   for (const auto &RF : InitOpts.RemappedFiles) {
    263     // Find the file that we're mapping to.
    264     const FileEntry *ToFile = FileMgr.getFile(RF.second);
    265     if (!ToFile) {
    266       Diags.Report(diag::err_fe_remap_missing_to_file) << RF.first << RF.second;
    267       continue;
    268     }
    269 
    270     // Create the file entry for the file that we're mapping from.
    271     const FileEntry *FromFile =
    272         FileMgr.getVirtualFile(RF.first, ToFile->getSize(), 0);
    273     if (!FromFile) {
    274       Diags.Report(diag::err_fe_remap_missing_from_file) << RF.first;
    275       continue;
    276     }
    277 
    278     // Override the contents of the "from" file with the contents of
    279     // the "to" file.
    280     SourceMgr.overrideFileContents(FromFile, ToFile);
    281   }
    282 
    283   SourceMgr.setOverridenFilesKeepOriginalName(
    284       InitOpts.RemappedFilesKeepOriginalName);
    285 }
    286 
    287 // Preprocessor
    288 
    289 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
    290   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
    291 
    292   // Create a PTH manager if we are using some form of a token cache.
    293   PTHManager *PTHMgr = nullptr;
    294   if (!PPOpts.TokenCache.empty())
    295     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
    296 
    297   // Create the Preprocessor.
    298   HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
    299                                               getSourceManager(),
    300                                               getDiagnostics(),
    301                                               getLangOpts(),
    302                                               &getTarget());
    303   PP = new Preprocessor(&getPreprocessorOpts(), getDiagnostics(), getLangOpts(),
    304                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
    305                         /*OwnsHeaderSearch=*/true, TUKind);
    306   PP->Initialize(getTarget());
    307 
    308   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
    309   // That argument is used as the IdentifierInfoLookup argument to
    310   // IdentifierTable's ctor.
    311   if (PTHMgr) {
    312     PTHMgr->setPreprocessor(&*PP);
    313     PP->setPTHManager(PTHMgr);
    314   }
    315 
    316   if (PPOpts.DetailedRecord)
    317     PP->createPreprocessingRecord();
    318 
    319   // Apply remappings to the source manager.
    320   InitializeFileRemapping(PP->getDiagnostics(), PP->getSourceManager(),
    321                           PP->getFileManager(), PPOpts);
    322 
    323   // Predefine macros and configure the preprocessor.
    324   InitializePreprocessor(*PP, PPOpts, getFrontendOpts());
    325 
    326   // Initialize the header search object.
    327   ApplyHeaderSearchOptions(PP->getHeaderSearchInfo(), getHeaderSearchOpts(),
    328                            PP->getLangOpts(), PP->getTargetInfo().getTriple());
    329 
    330   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
    331 
    332   // Set up the module path, including the hash for the
    333   // module-creation options.
    334   SmallString<256> SpecificModuleCache(
    335                            getHeaderSearchOpts().ModuleCachePath);
    336   if (!getHeaderSearchOpts().DisableModuleHash)
    337     llvm::sys::path::append(SpecificModuleCache,
    338                             getInvocation().getModuleHash());
    339   PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
    340 
    341   // Handle generating dependencies, if requested.
    342   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
    343   if (!DepOpts.OutputFile.empty())
    344     TheDependencyFileGenerator.reset(
    345         DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
    346   if (!DepOpts.DOTOutputFile.empty())
    347     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
    348                              getHeaderSearchOpts().Sysroot);
    349 
    350   for (auto &Listener : DependencyCollectors)
    351     Listener->attachToPreprocessor(*PP);
    352 
    353   // If we don't have a collector, but we are collecting module dependencies,
    354   // then we're the top level compiler instance and need to create one.
    355   if (!ModuleDepCollector && !DepOpts.ModuleDependencyOutputDir.empty())
    356     ModuleDepCollector = std::make_shared<ModuleDependencyCollector>(
    357         DepOpts.ModuleDependencyOutputDir);
    358 
    359   // Handle generating header include information, if requested.
    360   if (DepOpts.ShowHeaderIncludes)
    361     AttachHeaderIncludeGen(*PP);
    362   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
    363     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
    364     if (OutputPath == "-")
    365       OutputPath = "";
    366     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
    367                            /*ShowDepth=*/false);
    368   }
    369 
    370   if (DepOpts.PrintShowIncludes) {
    371     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
    372                            /*ShowDepth=*/true, /*MSStyle=*/true);
    373   }
    374 }
    375 
    376 // ASTContext
    377 
    378 void CompilerInstance::createASTContext() {
    379   Preprocessor &PP = getPreprocessor();
    380   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
    381                            PP.getIdentifierTable(), PP.getSelectorTable(),
    382                            PP.getBuiltinInfo());
    383   Context->InitBuiltinTypes(getTarget());
    384 }
    385 
    386 // ExternalASTSource
    387 
    388 void CompilerInstance::createPCHExternalASTSource(
    389     StringRef Path, bool DisablePCHValidation, bool AllowPCHWithCompilerErrors,
    390     void *DeserializationListener, bool OwnDeserializationListener) {
    391   IntrusiveRefCntPtr<ExternalASTSource> Source;
    392   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
    393   Source = createPCHExternalASTSource(
    394       Path, getHeaderSearchOpts().Sysroot, DisablePCHValidation,
    395       AllowPCHWithCompilerErrors, getPreprocessor(), getASTContext(),
    396       DeserializationListener, OwnDeserializationListener, Preamble,
    397       getFrontendOpts().UseGlobalModuleIndex);
    398   ModuleManager = static_cast<ASTReader*>(Source.get());
    399   getASTContext().setExternalSource(Source);
    400 }
    401 
    402 ExternalASTSource *CompilerInstance::createPCHExternalASTSource(
    403     StringRef Path, const std::string &Sysroot, bool DisablePCHValidation,
    404     bool AllowPCHWithCompilerErrors, Preprocessor &PP, ASTContext &Context,
    405     void *DeserializationListener, bool OwnDeserializationListener,
    406     bool Preamble, bool UseGlobalModuleIndex) {
    407   HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
    408 
    409   std::unique_ptr<ASTReader> Reader;
    410   Reader.reset(new ASTReader(PP, Context,
    411                              Sysroot.empty() ? "" : Sysroot.c_str(),
    412                              DisablePCHValidation,
    413                              AllowPCHWithCompilerErrors,
    414                              /*AllowConfigurationMismatch*/false,
    415                              HSOpts.ModulesValidateSystemHeaders,
    416                              UseGlobalModuleIndex));
    417 
    418   Reader->setDeserializationListener(
    419       static_cast<ASTDeserializationListener *>(DeserializationListener),
    420       /*TakeOwnership=*/OwnDeserializationListener);
    421   switch (Reader->ReadAST(Path,
    422                           Preamble ? serialization::MK_Preamble
    423                                    : serialization::MK_PCH,
    424                           SourceLocation(),
    425                           ASTReader::ARR_None)) {
    426   case ASTReader::Success:
    427     // Set the predefines buffer as suggested by the PCH reader. Typically, the
    428     // predefines buffer will be empty.
    429     PP.setPredefines(Reader->getSuggestedPredefines());
    430     return Reader.release();
    431 
    432   case ASTReader::Failure:
    433     // Unrecoverable failure: don't even try to process the input file.
    434     break;
    435 
    436   case ASTReader::Missing:
    437   case ASTReader::OutOfDate:
    438   case ASTReader::VersionMismatch:
    439   case ASTReader::ConfigurationMismatch:
    440   case ASTReader::HadErrors:
    441     // No suitable PCH file could be found. Return an error.
    442     break;
    443   }
    444 
    445   return nullptr;
    446 }
    447 
    448 // Code Completion
    449 
    450 static bool EnableCodeCompletion(Preprocessor &PP,
    451                                  const std::string &Filename,
    452                                  unsigned Line,
    453                                  unsigned Column) {
    454   // Tell the source manager to chop off the given file at a specific
    455   // line and column.
    456   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
    457   if (!Entry) {
    458     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
    459       << Filename;
    460     return true;
    461   }
    462 
    463   // Truncate the named file at the given line/column.
    464   PP.SetCodeCompletionPoint(Entry, Line, Column);
    465   return false;
    466 }
    467 
    468 void CompilerInstance::createCodeCompletionConsumer() {
    469   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
    470   if (!CompletionConsumer) {
    471     setCodeCompletionConsumer(
    472       createCodeCompletionConsumer(getPreprocessor(),
    473                                    Loc.FileName, Loc.Line, Loc.Column,
    474                                    getFrontendOpts().CodeCompleteOpts,
    475                                    llvm::outs()));
    476     if (!CompletionConsumer)
    477       return;
    478   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
    479                                   Loc.Line, Loc.Column)) {
    480     setCodeCompletionConsumer(nullptr);
    481     return;
    482   }
    483 
    484   if (CompletionConsumer->isOutputBinary() &&
    485       llvm::sys::ChangeStdoutToBinary()) {
    486     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
    487     setCodeCompletionConsumer(nullptr);
    488   }
    489 }
    490 
    491 void CompilerInstance::createFrontendTimer() {
    492   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
    493 }
    494 
    495 CodeCompleteConsumer *
    496 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
    497                                                const std::string &Filename,
    498                                                unsigned Line,
    499                                                unsigned Column,
    500                                                const CodeCompleteOptions &Opts,
    501                                                raw_ostream &OS) {
    502   if (EnableCodeCompletion(PP, Filename, Line, Column))
    503     return nullptr;
    504 
    505   // Set up the creation routine for code-completion.
    506   return new PrintingCodeCompleteConsumer(Opts, OS);
    507 }
    508 
    509 void CompilerInstance::createSema(TranslationUnitKind TUKind,
    510                                   CodeCompleteConsumer *CompletionConsumer) {
    511   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
    512                          TUKind, CompletionConsumer));
    513 }
    514 
    515 // Output Files
    516 
    517 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
    518   assert(OutFile.OS && "Attempt to add empty stream to output list!");
    519   OutputFiles.push_back(OutFile);
    520 }
    521 
    522 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
    523   for (std::list<OutputFile>::iterator
    524          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
    525     delete it->OS;
    526     if (!it->TempFilename.empty()) {
    527       if (EraseFiles) {
    528         llvm::sys::fs::remove(it->TempFilename);
    529       } else {
    530         SmallString<128> NewOutFile(it->Filename);
    531 
    532         // If '-working-directory' was passed, the output filename should be
    533         // relative to that.
    534         FileMgr->FixupRelativePath(NewOutFile);
    535         if (std::error_code ec =
    536                 llvm::sys::fs::rename(it->TempFilename, NewOutFile.str())) {
    537           getDiagnostics().Report(diag::err_unable_to_rename_temp)
    538             << it->TempFilename << it->Filename << ec.message();
    539 
    540           llvm::sys::fs::remove(it->TempFilename);
    541         }
    542       }
    543     } else if (!it->Filename.empty() && EraseFiles)
    544       llvm::sys::fs::remove(it->Filename);
    545 
    546   }
    547   OutputFiles.clear();
    548 }
    549 
    550 llvm::raw_fd_ostream *
    551 CompilerInstance::createDefaultOutputFile(bool Binary,
    552                                           StringRef InFile,
    553                                           StringRef Extension) {
    554   return createOutputFile(getFrontendOpts().OutputFile, Binary,
    555                           /*RemoveFileOnSignal=*/true, InFile, Extension,
    556                           /*UseTemporary=*/true);
    557 }
    558 
    559 llvm::raw_null_ostream *CompilerInstance::createNullOutputFile() {
    560   llvm::raw_null_ostream *OS = new llvm::raw_null_ostream();
    561   addOutputFile(OutputFile("", "", OS));
    562   return OS;
    563 }
    564 
    565 llvm::raw_fd_ostream *
    566 CompilerInstance::createOutputFile(StringRef OutputPath,
    567                                    bool Binary, bool RemoveFileOnSignal,
    568                                    StringRef InFile,
    569                                    StringRef Extension,
    570                                    bool UseTemporary,
    571                                    bool CreateMissingDirectories) {
    572   std::string Error, OutputPathName, TempPathName;
    573   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
    574                                               RemoveFileOnSignal,
    575                                               InFile, Extension,
    576                                               UseTemporary,
    577                                               CreateMissingDirectories,
    578                                               &OutputPathName,
    579                                               &TempPathName);
    580   if (!OS) {
    581     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
    582       << OutputPath << Error;
    583     return nullptr;
    584   }
    585 
    586   // Add the output file -- but don't try to remove "-", since this means we are
    587   // using stdin.
    588   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
    589                 TempPathName, OS));
    590 
    591   return OS;
    592 }
    593 
    594 llvm::raw_fd_ostream *
    595 CompilerInstance::createOutputFile(StringRef OutputPath,
    596                                    std::string &Error,
    597                                    bool Binary,
    598                                    bool RemoveFileOnSignal,
    599                                    StringRef InFile,
    600                                    StringRef Extension,
    601                                    bool UseTemporary,
    602                                    bool CreateMissingDirectories,
    603                                    std::string *ResultPathName,
    604                                    std::string *TempPathName) {
    605   assert((!CreateMissingDirectories || UseTemporary) &&
    606          "CreateMissingDirectories is only allowed when using temporary files");
    607 
    608   std::string OutFile, TempFile;
    609   if (!OutputPath.empty()) {
    610     OutFile = OutputPath;
    611   } else if (InFile == "-") {
    612     OutFile = "-";
    613   } else if (!Extension.empty()) {
    614     SmallString<128> Path(InFile);
    615     llvm::sys::path::replace_extension(Path, Extension);
    616     OutFile = Path.str();
    617   } else {
    618     OutFile = "-";
    619   }
    620 
    621   std::unique_ptr<llvm::raw_fd_ostream> OS;
    622   std::string OSFile;
    623 
    624   if (UseTemporary) {
    625     if (OutFile == "-")
    626       UseTemporary = false;
    627     else {
    628       llvm::sys::fs::file_status Status;
    629       llvm::sys::fs::status(OutputPath, Status);
    630       if (llvm::sys::fs::exists(Status)) {
    631         // Fail early if we can't write to the final destination.
    632         if (!llvm::sys::fs::can_write(OutputPath))
    633           return nullptr;
    634 
    635         // Don't use a temporary if the output is a special file. This handles
    636         // things like '-o /dev/null'
    637         if (!llvm::sys::fs::is_regular_file(Status))
    638           UseTemporary = false;
    639       }
    640     }
    641   }
    642 
    643   if (UseTemporary) {
    644     // Create a temporary file.
    645     SmallString<128> TempPath;
    646     TempPath = OutFile;
    647     TempPath += "-%%%%%%%%";
    648     int fd;
    649     std::error_code EC =
    650         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
    651 
    652     if (CreateMissingDirectories &&
    653         EC == llvm::errc::no_such_file_or_directory) {
    654       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
    655       EC = llvm::sys::fs::create_directories(Parent);
    656       if (!EC) {
    657         EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
    658       }
    659     }
    660 
    661     if (!EC) {
    662       OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
    663       OSFile = TempFile = TempPath.str();
    664     }
    665     // If we failed to create the temporary, fallback to writing to the file
    666     // directly. This handles the corner case where we cannot write to the
    667     // directory, but can write to the file.
    668   }
    669 
    670   if (!OS) {
    671     OSFile = OutFile;
    672     OS.reset(new llvm::raw_fd_ostream(
    673         OSFile.c_str(), Error,
    674         (Binary ? llvm::sys::fs::F_None : llvm::sys::fs::F_Text)));
    675     if (!Error.empty())
    676       return nullptr;
    677   }
    678 
    679   // Make sure the out stream file gets removed if we crash.
    680   if (RemoveFileOnSignal)
    681     llvm::sys::RemoveFileOnSignal(OSFile);
    682 
    683   if (ResultPathName)
    684     *ResultPathName = OutFile;
    685   if (TempPathName)
    686     *TempPathName = TempFile;
    687 
    688   return OS.release();
    689 }
    690 
    691 // Initialization Utilities
    692 
    693 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
    694   return InitializeSourceManager(Input, getDiagnostics(),
    695                                  getFileManager(), getSourceManager(),
    696                                  getFrontendOpts());
    697 }
    698 
    699 bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
    700                                                DiagnosticsEngine &Diags,
    701                                                FileManager &FileMgr,
    702                                                SourceManager &SourceMgr,
    703                                                const FrontendOptions &Opts) {
    704   SrcMgr::CharacteristicKind
    705     Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
    706 
    707   if (Input.isBuffer()) {
    708     SourceMgr.setMainFileID(SourceMgr.createFileID(Input.getBuffer(), Kind));
    709     assert(!SourceMgr.getMainFileID().isInvalid() &&
    710            "Couldn't establish MainFileID!");
    711     return true;
    712   }
    713 
    714   StringRef InputFile = Input.getFile();
    715 
    716   // Figure out where to get and map in the main file.
    717   if (InputFile != "-") {
    718     const FileEntry *File = FileMgr.getFile(InputFile, /*OpenFile=*/true);
    719     if (!File) {
    720       Diags.Report(diag::err_fe_error_reading) << InputFile;
    721       return false;
    722     }
    723 
    724     // The natural SourceManager infrastructure can't currently handle named
    725     // pipes, but we would at least like to accept them for the main
    726     // file. Detect them here, read them with the volatile flag so FileMgr will
    727     // pick up the correct size, and simply override their contents as we do for
    728     // STDIN.
    729     if (File->isNamedPipe()) {
    730       std::string ErrorStr;
    731       if (llvm::MemoryBuffer *MB =
    732               FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true)) {
    733         // Create a new virtual file that will have the correct size.
    734         File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
    735         SourceMgr.overrideFileContents(File, MB);
    736       } else {
    737         Diags.Report(diag::err_cannot_open_file) << InputFile << ErrorStr;
    738         return false;
    739       }
    740     }
    741 
    742     SourceMgr.setMainFileID(
    743         SourceMgr.createFileID(File, SourceLocation(), Kind));
    744   } else {
    745     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> SBOrErr =
    746         llvm::MemoryBuffer::getSTDIN();
    747     if (std::error_code EC = SBOrErr.getError()) {
    748       Diags.Report(diag::err_fe_error_reading_stdin) << EC.message();
    749       return false;
    750     }
    751     std::unique_ptr<llvm::MemoryBuffer> SB = std::move(SBOrErr.get());
    752 
    753     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
    754                                                    SB->getBufferSize(), 0);
    755     SourceMgr.setMainFileID(
    756         SourceMgr.createFileID(File, SourceLocation(), Kind));
    757     SourceMgr.overrideFileContents(File, SB.release());
    758   }
    759 
    760   assert(!SourceMgr.getMainFileID().isInvalid() &&
    761          "Couldn't establish MainFileID!");
    762   return true;
    763 }
    764 
    765 // High-Level Operations
    766 
    767 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
    768   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
    769   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
    770   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
    771 
    772   // FIXME: Take this as an argument, once all the APIs we used have moved to
    773   // taking it as an input instead of hard-coding llvm::errs.
    774   raw_ostream &OS = llvm::errs();
    775 
    776   // Create the target instance.
    777   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(),
    778                                          getInvocation().TargetOpts));
    779   if (!hasTarget())
    780     return false;
    781 
    782   // Inform the target of the language options.
    783   //
    784   // FIXME: We shouldn't need to do this, the target should be immutable once
    785   // created. This complexity should be lifted elsewhere.
    786   getTarget().adjust(getLangOpts());
    787 
    788   // rewriter project will change target built-in bool type from its default.
    789   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
    790     getTarget().noSignedCharForObjCBool();
    791 
    792   // Validate/process some options.
    793   if (getHeaderSearchOpts().Verbose)
    794     OS << "clang -cc1 version " CLANG_VERSION_STRING
    795        << " based upon " << BACKEND_PACKAGE_STRING
    796        << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
    797 
    798   if (getFrontendOpts().ShowTimers)
    799     createFrontendTimer();
    800 
    801   if (getFrontendOpts().ShowStats)
    802     llvm::EnableStatistics();
    803 
    804   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
    805     // Reset the ID tables if we are reusing the SourceManager.
    806     if (hasSourceManager())
    807       getSourceManager().clearIDTables();
    808 
    809     if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
    810       Act.Execute();
    811       Act.EndSourceFile();
    812     }
    813   }
    814 
    815   // Notify the diagnostic client that all files were processed.
    816   getDiagnostics().getClient()->finish();
    817 
    818   if (getDiagnosticOpts().ShowCarets) {
    819     // We can have multiple diagnostics sharing one diagnostic client.
    820     // Get the total number of warnings/errors from the client.
    821     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
    822     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
    823 
    824     if (NumWarnings)
    825       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
    826     if (NumWarnings && NumErrors)
    827       OS << " and ";
    828     if (NumErrors)
    829       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
    830     if (NumWarnings || NumErrors)
    831       OS << " generated.\n";
    832   }
    833 
    834   if (getFrontendOpts().ShowStats && hasFileManager()) {
    835     getFileManager().PrintStats();
    836     OS << "\n";
    837   }
    838 
    839   return !getDiagnostics().getClient()->getNumErrors();
    840 }
    841 
    842 /// \brief Determine the appropriate source input kind based on language
    843 /// options.
    844 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
    845   if (LangOpts.OpenCL)
    846     return IK_OpenCL;
    847   if (LangOpts.CUDA)
    848     return IK_CUDA;
    849   if (LangOpts.ObjC1)
    850     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
    851   return LangOpts.CPlusPlus? IK_CXX : IK_C;
    852 }
    853 
    854 /// \brief Compile a module file for the given module, using the options
    855 /// provided by the importing compiler instance.
    856 static void compileModuleImpl(CompilerInstance &ImportingInstance,
    857                           SourceLocation ImportLoc,
    858                           Module *Module,
    859                           StringRef ModuleFileName) {
    860   ModuleMap &ModMap
    861     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
    862 
    863   // Construct a compiler invocation for creating this module.
    864   IntrusiveRefCntPtr<CompilerInvocation> Invocation
    865     (new CompilerInvocation(ImportingInstance.getInvocation()));
    866 
    867   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
    868 
    869   // For any options that aren't intended to affect how a module is built,
    870   // reset them to their default values.
    871   Invocation->getLangOpts()->resetNonModularOptions();
    872   PPOpts.resetNonModularOptions();
    873 
    874   // Remove any macro definitions that are explicitly ignored by the module.
    875   // They aren't supposed to affect how the module is built anyway.
    876   const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
    877   PPOpts.Macros.erase(
    878       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
    879                      [&HSOpts](const std::pair<std::string, bool> &def) {
    880         StringRef MacroDef = def.first;
    881         return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
    882       }),
    883       PPOpts.Macros.end());
    884 
    885   // Note the name of the module we're building.
    886   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
    887 
    888   // Make sure that the failed-module structure has been allocated in
    889   // the importing instance, and propagate the pointer to the newly-created
    890   // instance.
    891   PreprocessorOptions &ImportingPPOpts
    892     = ImportingInstance.getInvocation().getPreprocessorOpts();
    893   if (!ImportingPPOpts.FailedModules)
    894     ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
    895   PPOpts.FailedModules = ImportingPPOpts.FailedModules;
    896 
    897   // If there is a module map file, build the module using the module map.
    898   // Set up the inputs/outputs so that we build the module from its umbrella
    899   // header.
    900   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
    901   FrontendOpts.OutputFile = ModuleFileName.str();
    902   FrontendOpts.DisableFree = false;
    903   FrontendOpts.GenerateGlobalModuleIndex = false;
    904   FrontendOpts.Inputs.clear();
    905   InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
    906 
    907   // Don't free the remapped file buffers; they are owned by our caller.
    908   PPOpts.RetainRemappedFileBuffers = true;
    909 
    910   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
    911   assert(ImportingInstance.getInvocation().getModuleHash() ==
    912          Invocation->getModuleHash() && "Module hash mismatch!");
    913 
    914   // Construct a compiler instance that will be used to actually create the
    915   // module.
    916   CompilerInstance Instance(/*BuildingModule=*/true);
    917   Instance.setInvocation(&*Invocation);
    918 
    919   Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
    920                                    ImportingInstance.getDiagnosticClient()),
    921                              /*ShouldOwnClient=*/true);
    922 
    923   Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
    924 
    925   // Note that this module is part of the module build stack, so that we
    926   // can detect cycles in the module graph.
    927   Instance.setFileManager(&ImportingInstance.getFileManager());
    928   Instance.createSourceManager(Instance.getFileManager());
    929   SourceManager &SourceMgr = Instance.getSourceManager();
    930   SourceMgr.setModuleBuildStack(
    931     ImportingInstance.getSourceManager().getModuleBuildStack());
    932   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
    933     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
    934 
    935   // If we're collecting module dependencies, we need to share a collector
    936   // between all of the module CompilerInstances.
    937   Instance.setModuleDepCollector(ImportingInstance.getModuleDepCollector());
    938 
    939   // Get or create the module map that we'll use to build this module.
    940   std::string InferredModuleMapContent;
    941   if (const FileEntry *ModuleMapFile =
    942           ModMap.getContainingModuleMapFile(Module)) {
    943     // Use the module map where this module resides.
    944     FrontendOpts.Inputs.push_back(
    945         FrontendInputFile(ModuleMapFile->getName(), IK));
    946   } else {
    947     llvm::raw_string_ostream OS(InferredModuleMapContent);
    948     Module->print(OS);
    949     OS.flush();
    950     FrontendOpts.Inputs.push_back(
    951         FrontendInputFile("__inferred_module.map", IK));
    952 
    953     llvm::MemoryBuffer *ModuleMapBuffer =
    954         llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
    955     ModuleMapFile = Instance.getFileManager().getVirtualFile(
    956         "__inferred_module.map", InferredModuleMapContent.size(), 0);
    957     SourceMgr.overrideFileContents(ModuleMapFile, ModuleMapBuffer);
    958   }
    959 
    960   // Construct a module-generating action. Passing through Module->ModuleMap is
    961   // safe because the FileManager is shared between the compiler instances.
    962   GenerateModuleAction CreateModuleAction(Module->ModuleMap, Module->IsSystem);
    963 
    964   // Execute the action to actually build the module in-place. Use a separate
    965   // thread so that we get a stack large enough.
    966   const unsigned ThreadStackSize = 8 << 20;
    967   llvm::CrashRecoveryContext CRC;
    968   CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
    969                         ThreadStackSize);
    970 
    971   // Delete the temporary module map file.
    972   // FIXME: Even though we're executing under crash protection, it would still
    973   // be nice to do this with RemoveFileOnSignal when we can. However, that
    974   // doesn't make sense for all clients, so clean this up manually.
    975   Instance.clearOutputFiles(/*EraseFiles=*/true);
    976 
    977   // We've rebuilt a module. If we're allowed to generate or update the global
    978   // module index, record that fact in the importing compiler instance.
    979   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
    980     ImportingInstance.setBuildGlobalModuleIndex(true);
    981   }
    982 }
    983 
    984 static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
    985                                  SourceLocation ImportLoc,
    986                                  SourceLocation ModuleNameLoc,
    987                                  Module *Module,
    988                                  StringRef ModuleFileName) {
    989   // FIXME: have LockFileManager return an error_code so that we can
    990   // avoid the mkdir when the directory already exists.
    991   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
    992   llvm::sys::fs::create_directories(Dir);
    993 
    994   while (1) {
    995     unsigned ModuleLoadCapabilities = ASTReader::ARR_Missing;
    996     llvm::LockFileManager Locked(ModuleFileName);
    997     switch (Locked) {
    998     case llvm::LockFileManager::LFS_Error:
    999       return false;
   1000 
   1001     case llvm::LockFileManager::LFS_Owned:
   1002       // We're responsible for building the module ourselves.
   1003       // FIXME: if there are errors, don't attempt to load the module.
   1004       compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
   1005                         ModuleFileName);
   1006       break;
   1007 
   1008     case llvm::LockFileManager::LFS_Shared:
   1009       // Someone else is responsible for building the module. Wait for them to
   1010       // finish.
   1011       if (Locked.waitForUnlock() == llvm::LockFileManager::Res_OwnerDied)
   1012         continue; // try again to get the lock.
   1013       ModuleLoadCapabilities |= ASTReader::ARR_OutOfDate;
   1014       break;
   1015     }
   1016 
   1017     // Try to read the module file, now that we've compiled it.
   1018     ASTReader::ASTReadResult ReadResult =
   1019         ImportingInstance.getModuleManager()->ReadAST(
   1020             ModuleFileName, serialization::MK_Module, ImportLoc,
   1021             ModuleLoadCapabilities);
   1022 
   1023     if (ReadResult == ASTReader::OutOfDate &&
   1024         Locked == llvm::LockFileManager::LFS_Shared) {
   1025       // The module may be out of date in the presence of file system races,
   1026       // or if one of its imports depends on header search paths that are not
   1027       // consistent with this ImportingInstance.  Try again...
   1028       continue;
   1029     } else if (ReadResult == ASTReader::Missing) {
   1030       ImportingInstance.getDiagnostics().Report(ModuleNameLoc,
   1031                                                 diag::err_module_not_built)
   1032           << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
   1033     }
   1034     return ReadResult == ASTReader::Success;
   1035   }
   1036 }
   1037 
   1038 /// \brief Diagnose differences between the current definition of the given
   1039 /// configuration macro and the definition provided on the command line.
   1040 static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
   1041                              Module *Mod, SourceLocation ImportLoc) {
   1042   IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
   1043   SourceManager &SourceMgr = PP.getSourceManager();
   1044 
   1045   // If this identifier has never had a macro definition, then it could
   1046   // not have changed.
   1047   if (!Id->hadMacroDefinition())
   1048     return;
   1049 
   1050   // If this identifier does not currently have a macro definition,
   1051   // check whether it had one on the command line.
   1052   if (!Id->hasMacroDefinition()) {
   1053     MacroDirective::DefInfo LatestDef =
   1054         PP.getMacroDirectiveHistory(Id)->getDefinition();
   1055     for (MacroDirective::DefInfo Def = LatestDef; Def;
   1056            Def = Def.getPreviousDefinition()) {
   1057       FileID FID = SourceMgr.getFileID(Def.getLocation());
   1058       if (FID.isInvalid())
   1059         continue;
   1060 
   1061       // We only care about the predefines buffer.
   1062       if (FID != PP.getPredefinesFileID())
   1063         continue;
   1064 
   1065       // This macro was defined on the command line, then #undef'd later.
   1066       // Complain.
   1067       PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
   1068         << true << ConfigMacro << Mod->getFullModuleName();
   1069       if (LatestDef.isUndefined())
   1070         PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
   1071           << true;
   1072       return;
   1073     }
   1074 
   1075     // Okay: no definition in the predefines buffer.
   1076     return;
   1077   }
   1078 
   1079   // This identifier has a macro definition. Check whether we had a definition
   1080   // on the command line.
   1081   MacroDirective::DefInfo LatestDef =
   1082       PP.getMacroDirectiveHistory(Id)->getDefinition();
   1083   MacroDirective::DefInfo PredefinedDef;
   1084   for (MacroDirective::DefInfo Def = LatestDef; Def;
   1085          Def = Def.getPreviousDefinition()) {
   1086     FileID FID = SourceMgr.getFileID(Def.getLocation());
   1087     if (FID.isInvalid())
   1088       continue;
   1089 
   1090     // We only care about the predefines buffer.
   1091     if (FID != PP.getPredefinesFileID())
   1092       continue;
   1093 
   1094     PredefinedDef = Def;
   1095     break;
   1096   }
   1097 
   1098   // If there was no definition for this macro in the predefines buffer,
   1099   // complain.
   1100   if (!PredefinedDef ||
   1101       (!PredefinedDef.getLocation().isValid() &&
   1102        PredefinedDef.getUndefLocation().isValid())) {
   1103     PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
   1104       << false << ConfigMacro << Mod->getFullModuleName();
   1105     PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
   1106       << false;
   1107     return;
   1108   }
   1109 
   1110   // If the current macro definition is the same as the predefined macro
   1111   // definition, it's okay.
   1112   if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
   1113       LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
   1114                                               /*Syntactically=*/true))
   1115     return;
   1116 
   1117   // The macro definitions differ.
   1118   PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
   1119     << false << ConfigMacro << Mod->getFullModuleName();
   1120   PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
   1121     << false;
   1122 }
   1123 
   1124 /// \brief Write a new timestamp file with the given path.
   1125 static void writeTimestampFile(StringRef TimestampFile) {
   1126   std::string ErrorInfo;
   1127   llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
   1128                            llvm::sys::fs::F_None);
   1129 }
   1130 
   1131 /// \brief Prune the module cache of modules that haven't been accessed in
   1132 /// a long time.
   1133 static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
   1134   struct stat StatBuf;
   1135   llvm::SmallString<128> TimestampFile;
   1136   TimestampFile = HSOpts.ModuleCachePath;
   1137   llvm::sys::path::append(TimestampFile, "modules.timestamp");
   1138 
   1139   // Try to stat() the timestamp file.
   1140   if (::stat(TimestampFile.c_str(), &StatBuf)) {
   1141     // If the timestamp file wasn't there, create one now.
   1142     if (errno == ENOENT) {
   1143       writeTimestampFile(TimestampFile);
   1144     }
   1145     return;
   1146   }
   1147 
   1148   // Check whether the time stamp is older than our pruning interval.
   1149   // If not, do nothing.
   1150   time_t TimeStampModTime = StatBuf.st_mtime;
   1151   time_t CurrentTime = time(nullptr);
   1152   if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
   1153     return;
   1154 
   1155   // Write a new timestamp file so that nobody else attempts to prune.
   1156   // There is a benign race condition here, if two Clang instances happen to
   1157   // notice at the same time that the timestamp is out-of-date.
   1158   writeTimestampFile(TimestampFile);
   1159 
   1160   // Walk the entire module cache, looking for unused module files and module
   1161   // indices.
   1162   std::error_code EC;
   1163   SmallString<128> ModuleCachePathNative;
   1164   llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
   1165   for (llvm::sys::fs::directory_iterator
   1166          Dir(ModuleCachePathNative.str(), EC), DirEnd;
   1167        Dir != DirEnd && !EC; Dir.increment(EC)) {
   1168     // If we don't have a directory, there's nothing to look into.
   1169     if (!llvm::sys::fs::is_directory(Dir->path()))
   1170       continue;
   1171 
   1172     // Walk all of the files within this directory.
   1173     for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
   1174          File != FileEnd && !EC; File.increment(EC)) {
   1175       // We only care about module and global module index files.
   1176       StringRef Extension = llvm::sys::path::extension(File->path());
   1177       if (Extension != ".pcm" && Extension != ".timestamp" &&
   1178           llvm::sys::path::filename(File->path()) != "modules.idx")
   1179         continue;
   1180 
   1181       // Look at this file. If we can't stat it, there's nothing interesting
   1182       // there.
   1183       if (::stat(File->path().c_str(), &StatBuf))
   1184         continue;
   1185 
   1186       // If the file has been used recently enough, leave it there.
   1187       time_t FileAccessTime = StatBuf.st_atime;
   1188       if (CurrentTime - FileAccessTime <=
   1189               time_t(HSOpts.ModuleCachePruneAfter)) {
   1190         continue;
   1191       }
   1192 
   1193       // Remove the file.
   1194       llvm::sys::fs::remove(File->path());
   1195 
   1196       // Remove the timestamp file.
   1197       std::string TimpestampFilename = File->path() + ".timestamp";
   1198       llvm::sys::fs::remove(TimpestampFilename);
   1199     }
   1200 
   1201     // If we removed all of the files in the directory, remove the directory
   1202     // itself.
   1203     if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
   1204             llvm::sys::fs::directory_iterator() && !EC)
   1205       llvm::sys::fs::remove(Dir->path());
   1206   }
   1207 }
   1208 
   1209 void CompilerInstance::createModuleManager() {
   1210   if (!ModuleManager) {
   1211     if (!hasASTContext())
   1212       createASTContext();
   1213 
   1214     // If we're not recursively building a module, check whether we
   1215     // need to prune the module cache.
   1216     if (getSourceManager().getModuleBuildStack().empty() &&
   1217         getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
   1218         getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
   1219       pruneModuleCache(getHeaderSearchOpts());
   1220     }
   1221 
   1222     HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
   1223     std::string Sysroot = HSOpts.Sysroot;
   1224     const PreprocessorOptions &PPOpts = getPreprocessorOpts();
   1225     ModuleManager = new ASTReader(getPreprocessor(), *Context,
   1226                                   Sysroot.empty() ? "" : Sysroot.c_str(),
   1227                                   PPOpts.DisablePCHValidation,
   1228                                   /*AllowASTWithCompilerErrors=*/false,
   1229                                   /*AllowConfigurationMismatch=*/false,
   1230                                   HSOpts.ModulesValidateSystemHeaders,
   1231                                   getFrontendOpts().UseGlobalModuleIndex);
   1232     if (hasASTConsumer()) {
   1233       ModuleManager->setDeserializationListener(
   1234         getASTConsumer().GetASTDeserializationListener());
   1235       getASTContext().setASTMutationListener(
   1236         getASTConsumer().GetASTMutationListener());
   1237     }
   1238     getASTContext().setExternalSource(ModuleManager);
   1239     if (hasSema())
   1240       ModuleManager->InitializeSema(getSema());
   1241     if (hasASTConsumer())
   1242       ModuleManager->StartTranslationUnit(&getASTConsumer());
   1243   }
   1244 }
   1245 
   1246 ModuleLoadResult
   1247 CompilerInstance::loadModule(SourceLocation ImportLoc,
   1248                              ModuleIdPath Path,
   1249                              Module::NameVisibilityKind Visibility,
   1250                              bool IsInclusionDirective) {
   1251   // Determine what file we're searching from.
   1252   StringRef ModuleName = Path[0].first->getName();
   1253   SourceLocation ModuleNameLoc = Path[0].second;
   1254 
   1255   // If we've already handled this import, just return the cached result.
   1256   // This one-element cache is important to eliminate redundant diagnostics
   1257   // when both the preprocessor and parser see the same import declaration.
   1258   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
   1259     // Make the named module visible.
   1260     if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
   1261       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
   1262                                        ImportLoc, /*Complain=*/false);
   1263     return LastModuleImportResult;
   1264   }
   1265 
   1266   clang::Module *Module = nullptr;
   1267 
   1268   // If we don't already have information on this module, load the module now.
   1269   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
   1270     = KnownModules.find(Path[0].first);
   1271   if (Known != KnownModules.end()) {
   1272     // Retrieve the cached top-level module.
   1273     Module = Known->second;
   1274   } else if (ModuleName == getLangOpts().CurrentModule) {
   1275     // This is the module we're building.
   1276     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
   1277     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
   1278   } else {
   1279     // Search for a module with the given name.
   1280     Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
   1281     if (!Module) {
   1282       getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
   1283       << ModuleName
   1284       << SourceRange(ImportLoc, ModuleNameLoc);
   1285       ModuleBuildFailed = true;
   1286       return ModuleLoadResult();
   1287     }
   1288 
   1289     std::string ModuleFileName =
   1290         PP->getHeaderSearchInfo().getModuleFileName(Module);
   1291 
   1292     // If we don't already have an ASTReader, create one now.
   1293     if (!ModuleManager)
   1294       createModuleManager();
   1295 
   1296     if (TheDependencyFileGenerator)
   1297       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
   1298 
   1299     if (ModuleDepCollector)
   1300       ModuleDepCollector->attachToASTReader(*ModuleManager);
   1301 
   1302     for (auto &Listener : DependencyCollectors)
   1303       Listener->attachToASTReader(*ModuleManager);
   1304 
   1305     // Try to load the module file.
   1306     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
   1307     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
   1308                                    ImportLoc, ARRFlags)) {
   1309     case ASTReader::Success:
   1310       break;
   1311 
   1312     case ASTReader::OutOfDate:
   1313     case ASTReader::Missing: {
   1314       // The module file is missing or out-of-date. Build it.
   1315       assert(Module && "missing module file");
   1316       // Check whether there is a cycle in the module graph.
   1317       ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
   1318       ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
   1319       for (; Pos != PosEnd; ++Pos) {
   1320         if (Pos->first == ModuleName)
   1321           break;
   1322       }
   1323 
   1324       if (Pos != PosEnd) {
   1325         SmallString<256> CyclePath;
   1326         for (; Pos != PosEnd; ++Pos) {
   1327           CyclePath += Pos->first;
   1328           CyclePath += " -> ";
   1329         }
   1330         CyclePath += ModuleName;
   1331 
   1332         getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
   1333           << ModuleName << CyclePath;
   1334         return ModuleLoadResult();
   1335       }
   1336 
   1337       getDiagnostics().Report(ImportLoc, diag::remark_module_build)
   1338           << ModuleName << ModuleFileName;
   1339 
   1340       // Check whether we have already attempted to build this module (but
   1341       // failed).
   1342       if (getPreprocessorOpts().FailedModules &&
   1343           getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
   1344         getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
   1345           << ModuleName
   1346           << SourceRange(ImportLoc, ModuleNameLoc);
   1347         ModuleBuildFailed = true;
   1348         return ModuleLoadResult();
   1349       }
   1350 
   1351       // Try to compile and then load the module.
   1352       if (!compileAndLoadModule(*this, ImportLoc, ModuleNameLoc, Module,
   1353                                 ModuleFileName)) {
   1354         if (getPreprocessorOpts().FailedModules)
   1355           getPreprocessorOpts().FailedModules->addFailed(ModuleName);
   1356         KnownModules[Path[0].first] = nullptr;
   1357         ModuleBuildFailed = true;
   1358         return ModuleLoadResult();
   1359       }
   1360 
   1361       // Okay, we've rebuilt and now loaded the module.
   1362       break;
   1363     }
   1364 
   1365     case ASTReader::VersionMismatch:
   1366     case ASTReader::ConfigurationMismatch:
   1367     case ASTReader::HadErrors:
   1368       ModuleLoader::HadFatalFailure = true;
   1369       // FIXME: The ASTReader will already have complained, but can we showhorn
   1370       // that diagnostic information into a more useful form?
   1371       KnownModules[Path[0].first] = nullptr;
   1372       return ModuleLoadResult();
   1373 
   1374     case ASTReader::Failure:
   1375       ModuleLoader::HadFatalFailure = true;
   1376       // Already complained, but note now that we failed.
   1377       KnownModules[Path[0].first] = nullptr;
   1378       ModuleBuildFailed = true;
   1379       return ModuleLoadResult();
   1380     }
   1381 
   1382     // Cache the result of this top-level module lookup for later.
   1383     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
   1384   }
   1385 
   1386   // If we never found the module, fail.
   1387   if (!Module)
   1388     return ModuleLoadResult();
   1389 
   1390   // Verify that the rest of the module path actually corresponds to
   1391   // a submodule.
   1392   if (Path.size() > 1) {
   1393     for (unsigned I = 1, N = Path.size(); I != N; ++I) {
   1394       StringRef Name = Path[I].first->getName();
   1395       clang::Module *Sub = Module->findSubmodule(Name);
   1396 
   1397       if (!Sub) {
   1398         // Attempt to perform typo correction to find a module name that works.
   1399         SmallVector<StringRef, 2> Best;
   1400         unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
   1401 
   1402         for (clang::Module::submodule_iterator J = Module->submodule_begin(),
   1403                                             JEnd = Module->submodule_end();
   1404              J != JEnd; ++J) {
   1405           unsigned ED = Name.edit_distance((*J)->Name,
   1406                                            /*AllowReplacements=*/true,
   1407                                            BestEditDistance);
   1408           if (ED <= BestEditDistance) {
   1409             if (ED < BestEditDistance) {
   1410               Best.clear();
   1411               BestEditDistance = ED;
   1412             }
   1413 
   1414             Best.push_back((*J)->Name);
   1415           }
   1416         }
   1417 
   1418         // If there was a clear winner, user it.
   1419         if (Best.size() == 1) {
   1420           getDiagnostics().Report(Path[I].second,
   1421                                   diag::err_no_submodule_suggest)
   1422             << Path[I].first << Module->getFullModuleName() << Best[0]
   1423             << SourceRange(Path[0].second, Path[I-1].second)
   1424             << FixItHint::CreateReplacement(SourceRange(Path[I].second),
   1425                                             Best[0]);
   1426 
   1427           Sub = Module->findSubmodule(Best[0]);
   1428         }
   1429       }
   1430 
   1431       if (!Sub) {
   1432         // No submodule by this name. Complain, and don't look for further
   1433         // submodules.
   1434         getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
   1435           << Path[I].first << Module->getFullModuleName()
   1436           << SourceRange(Path[0].second, Path[I-1].second);
   1437         break;
   1438       }
   1439 
   1440       Module = Sub;
   1441     }
   1442   }
   1443 
   1444   // Make the named module visible, if it's not already part of the module
   1445   // we are parsing.
   1446   if (ModuleName != getLangOpts().CurrentModule) {
   1447     if (!Module->IsFromModuleFile) {
   1448       // We have an umbrella header or directory that doesn't actually include
   1449       // all of the headers within the directory it covers. Complain about
   1450       // this missing submodule and recover by forgetting that we ever saw
   1451       // this submodule.
   1452       // FIXME: Should we detect this at module load time? It seems fairly
   1453       // expensive (and rare).
   1454       getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
   1455         << Module->getFullModuleName()
   1456         << SourceRange(Path.front().second, Path.back().second);
   1457 
   1458       return ModuleLoadResult(nullptr, true);
   1459     }
   1460 
   1461     // Check whether this module is available.
   1462     clang::Module::Requirement Requirement;
   1463     clang::Module::HeaderDirective MissingHeader;
   1464     if (!Module->isAvailable(getLangOpts(), getTarget(), Requirement,
   1465                              MissingHeader)) {
   1466       if (MissingHeader.FileNameLoc.isValid()) {
   1467         getDiagnostics().Report(MissingHeader.FileNameLoc,
   1468                                 diag::err_module_header_missing)
   1469           << MissingHeader.IsUmbrella << MissingHeader.FileName;
   1470       } else {
   1471         getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
   1472           << Module->getFullModuleName()
   1473           << Requirement.second << Requirement.first
   1474           << SourceRange(Path.front().second, Path.back().second);
   1475       }
   1476       LastModuleImportLoc = ImportLoc;
   1477       LastModuleImportResult = ModuleLoadResult();
   1478       return ModuleLoadResult();
   1479     }
   1480 
   1481     ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
   1482                                      /*Complain=*/true);
   1483   }
   1484 
   1485   // Check for any configuration macros that have changed.
   1486   clang::Module *TopModule = Module->getTopLevelModule();
   1487   for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
   1488     checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
   1489                      Module, ImportLoc);
   1490   }
   1491 
   1492   // If this module import was due to an inclusion directive, create an
   1493   // implicit import declaration to capture it in the AST.
   1494   if (IsInclusionDirective && hasASTContext()) {
   1495     TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
   1496     ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
   1497                                                      ImportLoc, Module,
   1498                                                      Path.back().second);
   1499     TU->addDecl(ImportD);
   1500     if (Consumer)
   1501       Consumer->HandleImplicitImportDecl(ImportD);
   1502   }
   1503 
   1504   LastModuleImportLoc = ImportLoc;
   1505   LastModuleImportResult = ModuleLoadResult(Module, false);
   1506   return LastModuleImportResult;
   1507 }
   1508 
   1509 void CompilerInstance::makeModuleVisible(Module *Mod,
   1510                                          Module::NameVisibilityKind Visibility,
   1511                                          SourceLocation ImportLoc,
   1512                                          bool Complain){
   1513   ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
   1514 }
   1515 
   1516 GlobalModuleIndex *CompilerInstance::loadGlobalModuleIndex(
   1517     SourceLocation TriggerLoc) {
   1518   if (!ModuleManager)
   1519     createModuleManager();
   1520   // Can't do anything if we don't have the module manager.
   1521   if (!ModuleManager)
   1522     return nullptr;
   1523   // Get an existing global index.  This loads it if not already
   1524   // loaded.
   1525   ModuleManager->loadGlobalIndex();
   1526   GlobalModuleIndex *GlobalIndex = ModuleManager->getGlobalIndex();
   1527   // If the global index doesn't exist, create it.
   1528   if (!GlobalIndex && shouldBuildGlobalModuleIndex() && hasFileManager() &&
   1529       hasPreprocessor()) {
   1530     llvm::sys::fs::create_directories(
   1531       getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
   1532     GlobalModuleIndex::writeIndex(
   1533       getFileManager(),
   1534       getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
   1535     ModuleManager->resetForReload();
   1536     ModuleManager->loadGlobalIndex();
   1537     GlobalIndex = ModuleManager->getGlobalIndex();
   1538   }
   1539   // For finding modules needing to be imported for fixit messages,
   1540   // we need to make the global index cover all modules, so we do that here.
   1541   if (!HaveFullGlobalModuleIndex && GlobalIndex && !buildingModule()) {
   1542     ModuleMap &MMap = getPreprocessor().getHeaderSearchInfo().getModuleMap();
   1543     bool RecreateIndex = false;
   1544     for (ModuleMap::module_iterator I = MMap.module_begin(),
   1545         E = MMap.module_end(); I != E; ++I) {
   1546       Module *TheModule = I->second;
   1547       const FileEntry *Entry = TheModule->getASTFile();
   1548       if (!Entry) {
   1549         SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
   1550         Path.push_back(std::make_pair(
   1551 				  getPreprocessor().getIdentifierInfo(TheModule->Name), TriggerLoc));
   1552         std::reverse(Path.begin(), Path.end());
   1553 		    // Load a module as hidden.  This also adds it to the global index.
   1554         loadModule(TheModule->DefinitionLoc, Path,
   1555                                              Module::Hidden, false);
   1556         RecreateIndex = true;
   1557       }
   1558     }
   1559     if (RecreateIndex) {
   1560       GlobalModuleIndex::writeIndex(
   1561         getFileManager(),
   1562         getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
   1563       ModuleManager->resetForReload();
   1564       ModuleManager->loadGlobalIndex();
   1565       GlobalIndex = ModuleManager->getGlobalIndex();
   1566     }
   1567     HaveFullGlobalModuleIndex = true;
   1568   }
   1569   return GlobalIndex;
   1570 }
   1571 
   1572 // Check global module index for missing imports.
   1573 bool
   1574 CompilerInstance::lookupMissingImports(StringRef Name,
   1575                                        SourceLocation TriggerLoc) {
   1576   // Look for the symbol in non-imported modules, but only if an error
   1577   // actually occurred.
   1578   if (!buildingModule()) {
   1579     // Load global module index, or retrieve a previously loaded one.
   1580     GlobalModuleIndex *GlobalIndex = loadGlobalModuleIndex(
   1581       TriggerLoc);
   1582 
   1583     // Only if we have a global index.
   1584     if (GlobalIndex) {
   1585       GlobalModuleIndex::HitSet FoundModules;
   1586 
   1587       // Find the modules that reference the identifier.
   1588       // Note that this only finds top-level modules.
   1589       // We'll let diagnoseTypo find the actual declaration module.
   1590       if (GlobalIndex->lookupIdentifier(Name, FoundModules))
   1591         return true;
   1592     }
   1593   }
   1594 
   1595   return false;
   1596 }
   1597