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
52using namespace clang;
53
54CompilerInstance::CompilerInstance(bool BuildingModule)
55  : ModuleLoader(BuildingModule),
56    Invocation(new CompilerInvocation()), ModuleManager(nullptr),
57    BuildGlobalModuleIndex(false), HaveFullGlobalModuleIndex(false),
58    ModuleBuildFailed(false) {
59}
60
61CompilerInstance::~CompilerInstance() {
62  assert(OutputFiles.empty() && "Still output files in flight?");
63}
64
65void CompilerInstance::setInvocation(CompilerInvocation *Value) {
66  Invocation = Value;
67}
68
69bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
70  return (BuildGlobalModuleIndex ||
71          (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
72           getFrontendOpts().GenerateGlobalModuleIndex)) &&
73         !ModuleBuildFailed;
74}
75
76void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
77  Diagnostics = Value;
78}
79
80void CompilerInstance::setTarget(TargetInfo *Value) {
81  Target = Value;
82}
83
84void CompilerInstance::setFileManager(FileManager *Value) {
85  FileMgr = Value;
86  if (Value)
87    VirtualFileSystem = Value->getVirtualFileSystem();
88  else
89    VirtualFileSystem.reset();
90}
91
92void CompilerInstance::setSourceManager(SourceManager *Value) {
93  SourceMgr = Value;
94}
95
96void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
97
98void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
99
100void CompilerInstance::setSema(Sema *S) {
101  TheSema.reset(S);
102}
103
104void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
105  Consumer.reset(Value);
106}
107
108void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
109  CompletionConsumer.reset(Value);
110}
111
112IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
113  return ModuleManager;
114}
115void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
116  ModuleManager = Reader;
117}
118
119std::shared_ptr<ModuleDependencyCollector>
120CompilerInstance::getModuleDepCollector() const {
121  return ModuleDepCollector;
122}
123
124void CompilerInstance::setModuleDepCollector(
125    std::shared_ptr<ModuleDependencyCollector> Collector) {
126  ModuleDepCollector = Collector;
127}
128
129// Diagnostics
130static 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
160static 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
181void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
182                                         bool ShouldOwnClient) {
183  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
184                                  ShouldOwnClient, &getCodeGenOpts());
185}
186
187IntrusiveRefCntPtr<DiagnosticsEngine>
188CompilerInstance::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
223void 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
233void 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.
239static 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
289void 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
378void 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
388void 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
402ExternalASTSource *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
450static 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
468void 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
491void CompilerInstance::createFrontendTimer() {
492  FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
493}
494
495CodeCompleteConsumer *
496CompilerInstance::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
509void CompilerInstance::createSema(TranslationUnitKind TUKind,
510                                  CodeCompleteConsumer *CompletionConsumer) {
511  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
512                         TUKind, CompletionConsumer));
513}
514
515// Output Files
516
517void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
518  assert(OutFile.OS && "Attempt to add empty stream to output list!");
519  OutputFiles.push_back(OutFile);
520}
521
522void 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
550llvm::raw_fd_ostream *
551CompilerInstance::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
559llvm::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
565llvm::raw_fd_ostream *
566CompilerInstance::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
594llvm::raw_fd_ostream *
595CompilerInstance::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
693bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
694  return InitializeSourceManager(Input, getDiagnostics(),
695                                 getFileManager(), getSourceManager(),
696                                 getFrontendOpts());
697}
698
699bool 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
767bool 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.
844static 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.
856static 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
984static 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.
1040static 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.
1125static 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.
1133static 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
1209void 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
1246ModuleLoadResult
1247CompilerInstance::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
1509void CompilerInstance::makeModuleVisible(Module *Mod,
1510                                         Module::NameVisibilityKind Visibility,
1511                                         SourceLocation ImportLoc,
1512                                         bool Complain){
1513  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1514}
1515
1516GlobalModuleIndex *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.
1573bool
1574CompilerInstance::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