CompilerInstance.cpp revision 708002ede3938256a6223d153a0c040f7a40f5cc 
1//===--- CompilerInstance.cpp ---------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "clang/Frontend/CompilerInstance.h"
11#include "clang/AST/ASTConsumer.h"
12#include "clang/AST/ASTContext.h"
13#include "clang/AST/Decl.h"
14#include "clang/Basic/Diagnostic.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Basic/SourceManager.h"
17#include "clang/Basic/TargetInfo.h"
18#include "clang/Basic/Version.h"
19#include "clang/Frontend/ChainedDiagnosticConsumer.h"
20#include "clang/Frontend/FrontendAction.h"
21#include "clang/Frontend/FrontendActions.h"
22#include "clang/Frontend/FrontendDiagnostic.h"
23#include "clang/Frontend/LogDiagnosticPrinter.h"
24#include "clang/Frontend/SerializedDiagnosticPrinter.h"
25#include "clang/Frontend/TextDiagnosticPrinter.h"
26#include "clang/Frontend/Utils.h"
27#include "clang/Frontend/VerifyDiagnosticConsumer.h"
28#include "clang/Lex/HeaderSearch.h"
29#include "clang/Lex/PTHManager.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/CodeCompleteConsumer.h"
32#include "clang/Sema/Sema.h"
33#include "clang/Serialization/ASTReader.h"
34#include "llvm/ADT/Statistic.h"
35#include "llvm/Config/config.h"
36#include "llvm/Support/CrashRecoveryContext.h"
37#include "llvm/Support/FileSystem.h"
38#include "llvm/Support/Host.h"
39#include "llvm/Support/LockFileManager.h"
40#include "llvm/Support/MemoryBuffer.h"
41#include "llvm/Support/Path.h"
42#include "llvm/Support/Program.h"
43#include "llvm/Support/Signals.h"
44#include "llvm/Support/Timer.h"
45#include "llvm/Support/raw_ostream.h"
46#include "llvm/Support/system_error.h"
47#include <sys/stat.h>
48#include <time.h>
49
50using namespace clang;
51
52CompilerInstance::CompilerInstance()
53  : Invocation(new CompilerInvocation()), ModuleManager(0),
54    BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
55}
56
57CompilerInstance::~CompilerInstance() {
58  assert(OutputFiles.empty() && "Still output files in flight?");
59}
60
61void CompilerInstance::setInvocation(CompilerInvocation *Value) {
62  Invocation = Value;
63}
64
65bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
66  return (BuildGlobalModuleIndex ||
67          (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
68           getFrontendOpts().GenerateGlobalModuleIndex)) &&
69         !ModuleBuildFailed;
70}
71
72void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
73  Diagnostics = Value;
74}
75
76void CompilerInstance::setTarget(TargetInfo *Value) {
77  Target = Value;
78}
79
80void CompilerInstance::setFileManager(FileManager *Value) {
81  FileMgr = Value;
82}
83
84void CompilerInstance::setSourceManager(SourceManager *Value) {
85  SourceMgr = Value;
86}
87
88void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
89
90void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
91
92void CompilerInstance::setSema(Sema *S) {
93  TheSema.reset(S);
94}
95
96void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
97  Consumer.reset(Value);
98}
99
100void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
101  CompletionConsumer.reset(Value);
102}
103
104// Diagnostics
105static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
106                               const CodeGenOptions *CodeGenOpts,
107                               DiagnosticsEngine &Diags) {
108  std::string ErrorInfo;
109  bool OwnsStream = false;
110  raw_ostream *OS = &llvm::errs();
111  if (DiagOpts->DiagnosticLogFile != "-") {
112    // Create the output stream.
113    llvm::raw_fd_ostream *FileOS(
114        new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(), ErrorInfo,
115                                 llvm::sys::fs::F_Append));
116    if (!ErrorInfo.empty()) {
117      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
118        << DiagOpts->DiagnosticLogFile << ErrorInfo;
119    } else {
120      FileOS->SetUnbuffered();
121      FileOS->SetUseAtomicWrites(true);
122      OS = FileOS;
123      OwnsStream = true;
124    }
125  }
126
127  // Chain in the diagnostic client which will log the diagnostics.
128  LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
129                                                          OwnsStream);
130  if (CodeGenOpts)
131    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
132  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
133}
134
135static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
136                                       DiagnosticsEngine &Diags,
137                                       StringRef OutputFile) {
138  std::string ErrorInfo;
139  OwningPtr<llvm::raw_fd_ostream> OS;
140  OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
141                                    llvm::sys::fs::F_Binary));
142
143  if (!ErrorInfo.empty()) {
144    Diags.Report(diag::warn_fe_serialized_diag_failure)
145      << OutputFile << ErrorInfo;
146    return;
147  }
148
149  DiagnosticConsumer *SerializedConsumer =
150    clang::serialized_diags::create(OS.take(), DiagOpts);
151
152
153  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
154                                                SerializedConsumer));
155}
156
157void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
158                                         bool ShouldOwnClient) {
159  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
160                                  ShouldOwnClient, &getCodeGenOpts());
161}
162
163IntrusiveRefCntPtr<DiagnosticsEngine>
164CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
165                                    DiagnosticConsumer *Client,
166                                    bool ShouldOwnClient,
167                                    const CodeGenOptions *CodeGenOpts) {
168  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
169  IntrusiveRefCntPtr<DiagnosticsEngine>
170      Diags(new DiagnosticsEngine(DiagID, Opts));
171
172  // Create the diagnostic client for reporting errors or for
173  // implementing -verify.
174  if (Client) {
175    Diags->setClient(Client, ShouldOwnClient);
176  } else
177    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
178
179  // Chain in -verify checker, if requested.
180  if (Opts->VerifyDiagnostics)
181    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
182
183  // Chain in -diagnostic-log-file dumper, if requested.
184  if (!Opts->DiagnosticLogFile.empty())
185    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
186
187  if (!Opts->DiagnosticSerializationFile.empty())
188    SetupSerializedDiagnostics(Opts, *Diags,
189                               Opts->DiagnosticSerializationFile);
190
191  // Configure our handling of diagnostics.
192  ProcessWarningOptions(*Diags, *Opts);
193
194  return Diags;
195}
196
197// File Manager
198
199void CompilerInstance::createFileManager() {
200  FileMgr = new FileManager(getFileSystemOpts());
201}
202
203// Source Manager
204
205void CompilerInstance::createSourceManager(FileManager &FileMgr) {
206  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
207}
208
209// Preprocessor
210
211void CompilerInstance::createPreprocessor() {
212  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
213
214  // Create a PTH manager if we are using some form of a token cache.
215  PTHManager *PTHMgr = 0;
216  if (!PPOpts.TokenCache.empty())
217    PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
218
219  // Create the Preprocessor.
220  HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
221                                              getFileManager(),
222                                              getDiagnostics(),
223                                              getLangOpts(),
224                                              &getTarget());
225  PP = new Preprocessor(&getPreprocessorOpts(),
226                        getDiagnostics(), getLangOpts(), &getTarget(),
227                        getSourceManager(), *HeaderInfo, *this, PTHMgr,
228                        /*OwnsHeaderSearch=*/true);
229
230  // Note that this is different then passing PTHMgr to Preprocessor's ctor.
231  // That argument is used as the IdentifierInfoLookup argument to
232  // IdentifierTable's ctor.
233  if (PTHMgr) {
234    PTHMgr->setPreprocessor(&*PP);
235    PP->setPTHManager(PTHMgr);
236  }
237
238  if (PPOpts.DetailedRecord)
239    PP->createPreprocessingRecord();
240
241  InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
242
243  PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
244
245  // Set up the module path, including the hash for the
246  // module-creation options.
247  SmallString<256> SpecificModuleCache(
248                           getHeaderSearchOpts().ModuleCachePath);
249  if (!getHeaderSearchOpts().DisableModuleHash)
250    llvm::sys::path::append(SpecificModuleCache,
251                            getInvocation().getModuleHash());
252  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
253
254  // Handle generating dependencies, if requested.
255  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
256  if (!DepOpts.OutputFile.empty())
257    AttachDependencyFileGen(*PP, DepOpts);
258  if (!DepOpts.DOTOutputFile.empty())
259    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
260                             getHeaderSearchOpts().Sysroot);
261
262
263  // Handle generating header include information, if requested.
264  if (DepOpts.ShowHeaderIncludes)
265    AttachHeaderIncludeGen(*PP);
266  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
267    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
268    if (OutputPath == "-")
269      OutputPath = "";
270    AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
271                           /*ShowDepth=*/false);
272  }
273
274  if (DepOpts.PrintShowIncludes) {
275    AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/false, /*OutputPath=*/"",
276                           /*ShowDepth=*/true, /*MSStyle=*/true);
277  }
278}
279
280// ASTContext
281
282void CompilerInstance::createASTContext() {
283  Preprocessor &PP = getPreprocessor();
284  Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
285                           &getTarget(), PP.getIdentifierTable(),
286                           PP.getSelectorTable(), PP.getBuiltinInfo(),
287                           /*size_reserve=*/ 0);
288}
289
290// ExternalASTSource
291
292void CompilerInstance::createPCHExternalASTSource(StringRef Path,
293                                                  bool DisablePCHValidation,
294                                                bool AllowPCHWithCompilerErrors,
295                                                 void *DeserializationListener){
296  OwningPtr<ExternalASTSource> Source;
297  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
298  Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
299                                          DisablePCHValidation,
300                                          AllowPCHWithCompilerErrors,
301                                          getPreprocessor(), getASTContext(),
302                                          DeserializationListener,
303                                          Preamble,
304                                       getFrontendOpts().UseGlobalModuleIndex));
305  ModuleManager = static_cast<ASTReader*>(Source.get());
306  getASTContext().setExternalSource(Source);
307}
308
309ExternalASTSource *
310CompilerInstance::createPCHExternalASTSource(StringRef Path,
311                                             const std::string &Sysroot,
312                                             bool DisablePCHValidation,
313                                             bool AllowPCHWithCompilerErrors,
314                                             Preprocessor &PP,
315                                             ASTContext &Context,
316                                             void *DeserializationListener,
317                                             bool Preamble,
318                                             bool UseGlobalModuleIndex) {
319  OwningPtr<ASTReader> Reader;
320  Reader.reset(new ASTReader(PP, Context,
321                             Sysroot.empty() ? "" : Sysroot.c_str(),
322                             DisablePCHValidation,
323                             AllowPCHWithCompilerErrors,
324                             UseGlobalModuleIndex));
325
326  Reader->setDeserializationListener(
327            static_cast<ASTDeserializationListener *>(DeserializationListener));
328  switch (Reader->ReadAST(Path,
329                          Preamble ? serialization::MK_Preamble
330                                   : serialization::MK_PCH,
331                          SourceLocation(),
332                          ASTReader::ARR_None)) {
333  case ASTReader::Success:
334    // Set the predefines buffer as suggested by the PCH reader. Typically, the
335    // predefines buffer will be empty.
336    PP.setPredefines(Reader->getSuggestedPredefines());
337    return Reader.take();
338
339  case ASTReader::Failure:
340    // Unrecoverable failure: don't even try to process the input file.
341    break;
342
343  case ASTReader::Missing:
344  case ASTReader::OutOfDate:
345  case ASTReader::VersionMismatch:
346  case ASTReader::ConfigurationMismatch:
347  case ASTReader::HadErrors:
348    // No suitable PCH file could be found. Return an error.
349    break;
350  }
351
352  return 0;
353}
354
355// Code Completion
356
357static bool EnableCodeCompletion(Preprocessor &PP,
358                                 const std::string &Filename,
359                                 unsigned Line,
360                                 unsigned Column) {
361  // Tell the source manager to chop off the given file at a specific
362  // line and column.
363  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
364  if (!Entry) {
365    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
366      << Filename;
367    return true;
368  }
369
370  // Truncate the named file at the given line/column.
371  PP.SetCodeCompletionPoint(Entry, Line, Column);
372  return false;
373}
374
375void CompilerInstance::createCodeCompletionConsumer() {
376  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
377  if (!CompletionConsumer) {
378    setCodeCompletionConsumer(
379      createCodeCompletionConsumer(getPreprocessor(),
380                                   Loc.FileName, Loc.Line, Loc.Column,
381                                   getFrontendOpts().CodeCompleteOpts,
382                                   llvm::outs()));
383    if (!CompletionConsumer)
384      return;
385  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
386                                  Loc.Line, Loc.Column)) {
387    setCodeCompletionConsumer(0);
388    return;
389  }
390
391  if (CompletionConsumer->isOutputBinary() &&
392      llvm::sys::ChangeStdoutToBinary()) {
393    getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
394    setCodeCompletionConsumer(0);
395  }
396}
397
398void CompilerInstance::createFrontendTimer() {
399  FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
400}
401
402CodeCompleteConsumer *
403CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
404                                               const std::string &Filename,
405                                               unsigned Line,
406                                               unsigned Column,
407                                               const CodeCompleteOptions &Opts,
408                                               raw_ostream &OS) {
409  if (EnableCodeCompletion(PP, Filename, Line, Column))
410    return 0;
411
412  // Set up the creation routine for code-completion.
413  return new PrintingCodeCompleteConsumer(Opts, OS);
414}
415
416void CompilerInstance::createSema(TranslationUnitKind TUKind,
417                                  CodeCompleteConsumer *CompletionConsumer) {
418  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
419                         TUKind, CompletionConsumer));
420}
421
422// Output Files
423
424void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
425  assert(OutFile.OS && "Attempt to add empty stream to output list!");
426  OutputFiles.push_back(OutFile);
427}
428
429void CompilerInstance::clearOutputFiles(bool EraseFiles) {
430  for (std::list<OutputFile>::iterator
431         it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
432    delete it->OS;
433    if (!it->TempFilename.empty()) {
434      if (EraseFiles) {
435        bool existed;
436        llvm::sys::fs::remove(it->TempFilename, existed);
437      } else {
438        SmallString<128> NewOutFile(it->Filename);
439
440        // If '-working-directory' was passed, the output filename should be
441        // relative to that.
442        FileMgr->FixupRelativePath(NewOutFile);
443        if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
444                                                        NewOutFile.str())) {
445          getDiagnostics().Report(diag::err_unable_to_rename_temp)
446            << it->TempFilename << it->Filename << ec.message();
447
448          bool existed;
449          llvm::sys::fs::remove(it->TempFilename, existed);
450        }
451      }
452    } else if (!it->Filename.empty() && EraseFiles)
453      llvm::sys::fs::remove(it->Filename);
454
455  }
456  OutputFiles.clear();
457}
458
459llvm::raw_fd_ostream *
460CompilerInstance::createDefaultOutputFile(bool Binary,
461                                          StringRef InFile,
462                                          StringRef Extension) {
463  return createOutputFile(getFrontendOpts().OutputFile, Binary,
464                          /*RemoveFileOnSignal=*/true, InFile, Extension,
465                          /*UseTemporary=*/true);
466}
467
468llvm::raw_fd_ostream *
469CompilerInstance::createOutputFile(StringRef OutputPath,
470                                   bool Binary, bool RemoveFileOnSignal,
471                                   StringRef InFile,
472                                   StringRef Extension,
473                                   bool UseTemporary,
474                                   bool CreateMissingDirectories) {
475  std::string Error, OutputPathName, TempPathName;
476  llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
477                                              RemoveFileOnSignal,
478                                              InFile, Extension,
479                                              UseTemporary,
480                                              CreateMissingDirectories,
481                                              &OutputPathName,
482                                              &TempPathName);
483  if (!OS) {
484    getDiagnostics().Report(diag::err_fe_unable_to_open_output)
485      << OutputPath << Error;
486    return 0;
487  }
488
489  // Add the output file -- but don't try to remove "-", since this means we are
490  // using stdin.
491  addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
492                TempPathName, OS));
493
494  return OS;
495}
496
497llvm::raw_fd_ostream *
498CompilerInstance::createOutputFile(StringRef OutputPath,
499                                   std::string &Error,
500                                   bool Binary,
501                                   bool RemoveFileOnSignal,
502                                   StringRef InFile,
503                                   StringRef Extension,
504                                   bool UseTemporary,
505                                   bool CreateMissingDirectories,
506                                   std::string *ResultPathName,
507                                   std::string *TempPathName) {
508  assert((!CreateMissingDirectories || UseTemporary) &&
509         "CreateMissingDirectories is only allowed when using temporary files");
510
511  std::string OutFile, TempFile;
512  if (!OutputPath.empty()) {
513    OutFile = OutputPath;
514  } else if (InFile == "-") {
515    OutFile = "-";
516  } else if (!Extension.empty()) {
517    SmallString<128> Path(InFile);
518    llvm::sys::path::replace_extension(Path, Extension);
519    OutFile = Path.str();
520  } else {
521    OutFile = "-";
522  }
523
524  OwningPtr<llvm::raw_fd_ostream> OS;
525  std::string OSFile;
526
527  if (UseTemporary) {
528    if (OutFile == "-")
529      UseTemporary = false;
530    else {
531      llvm::sys::fs::file_status Status;
532      llvm::sys::fs::status(OutputPath, Status);
533      if (llvm::sys::fs::exists(Status)) {
534        // Fail early if we can't write to the final destination.
535        if (!llvm::sys::fs::can_write(OutputPath))
536          return 0;
537
538        // Don't use a temporary if the output is a special file. This handles
539        // things like '-o /dev/null'
540        if (!llvm::sys::fs::is_regular_file(Status))
541          UseTemporary = false;
542      }
543    }
544  }
545
546  if (UseTemporary) {
547    // Create a temporary file.
548    SmallString<128> TempPath;
549    TempPath = OutFile;
550    TempPath += "-%%%%%%%%";
551    int fd;
552    llvm::error_code EC =
553        llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
554
555    if (CreateMissingDirectories &&
556        EC == llvm::errc::no_such_file_or_directory) {
557      StringRef Parent = llvm::sys::path::parent_path(OutputPath);
558      EC = llvm::sys::fs::create_directories(Parent);
559      if (!EC) {
560        EC = llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
561      }
562    }
563
564    if (!EC) {
565      OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
566      OSFile = TempFile = TempPath.str();
567    }
568    // If we failed to create the temporary, fallback to writing to the file
569    // directly. This handles the corner case where we cannot write to the
570    // directory, but can write to the file.
571  }
572
573  if (!OS) {
574    OSFile = OutFile;
575    OS.reset(new llvm::raw_fd_ostream(
576        OSFile.c_str(), Error,
577        (Binary ? llvm::sys::fs::F_Binary : llvm::sys::fs::F_None)));
578    if (!Error.empty())
579      return 0;
580  }
581
582  // Make sure the out stream file gets removed if we crash.
583  if (RemoveFileOnSignal)
584    llvm::sys::RemoveFileOnSignal(OSFile);
585
586  if (ResultPathName)
587    *ResultPathName = OutFile;
588  if (TempPathName)
589    *TempPathName = TempFile;
590
591  return OS.take();
592}
593
594// Initialization Utilities
595
596bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
597  return InitializeSourceManager(Input, getDiagnostics(),
598                                 getFileManager(), getSourceManager(),
599                                 getFrontendOpts());
600}
601
602bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
603                                               DiagnosticsEngine &Diags,
604                                               FileManager &FileMgr,
605                                               SourceManager &SourceMgr,
606                                               const FrontendOptions &Opts) {
607  SrcMgr::CharacteristicKind
608    Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
609
610  if (Input.isBuffer()) {
611    SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
612    assert(!SourceMgr.getMainFileID().isInvalid() &&
613           "Couldn't establish MainFileID!");
614    return true;
615  }
616
617  StringRef InputFile = Input.getFile();
618
619  // Figure out where to get and map in the main file.
620  if (InputFile != "-") {
621    const FileEntry *File = FileMgr.getFile(InputFile);
622    if (!File) {
623      Diags.Report(diag::err_fe_error_reading) << InputFile;
624      return false;
625    }
626
627    // The natural SourceManager infrastructure can't currently handle named
628    // pipes, but we would at least like to accept them for the main
629    // file. Detect them here, read them with the more generic MemoryBuffer
630    // function, and simply override their contents as we do for STDIN.
631    if (File->isNamedPipe()) {
632      OwningPtr<llvm::MemoryBuffer> MB;
633      if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
634        Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
635        return false;
636      }
637
638      // Create a new virtual file that will have the correct size.
639      File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
640      SourceMgr.overrideFileContents(File, MB.take());
641    }
642
643    SourceMgr.createMainFileID(File, Kind);
644  } else {
645    OwningPtr<llvm::MemoryBuffer> SB;
646    if (llvm::MemoryBuffer::getSTDIN(SB)) {
647      // FIXME: Give ec.message() in this diag.
648      Diags.Report(diag::err_fe_error_reading_stdin);
649      return false;
650    }
651    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
652                                                   SB->getBufferSize(), 0);
653    SourceMgr.createMainFileID(File, Kind);
654    SourceMgr.overrideFileContents(File, SB.take());
655  }
656
657  assert(!SourceMgr.getMainFileID().isInvalid() &&
658         "Couldn't establish MainFileID!");
659  return true;
660}
661
662// High-Level Operations
663
664bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
665  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
666  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
667  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
668
669  // FIXME: Take this as an argument, once all the APIs we used have moved to
670  // taking it as an input instead of hard-coding llvm::errs.
671  raw_ostream &OS = llvm::errs();
672
673  // Create the target instance.
674  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
675  if (!hasTarget())
676    return false;
677
678  // Inform the target of the language options.
679  //
680  // FIXME: We shouldn't need to do this, the target should be immutable once
681  // created. This complexity should be lifted elsewhere.
682  getTarget().setForcedLangOptions(getLangOpts());
683
684  // rewriter project will change target built-in bool type from its default.
685  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
686    getTarget().noSignedCharForObjCBool();
687
688  // Validate/process some options.
689  if (getHeaderSearchOpts().Verbose)
690    OS << "clang -cc1 version " CLANG_VERSION_STRING
691       << " based upon " << PACKAGE_STRING
692       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
693
694  if (getFrontendOpts().ShowTimers)
695    createFrontendTimer();
696
697  if (getFrontendOpts().ShowStats)
698    llvm::EnableStatistics();
699
700  for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
701    // Reset the ID tables if we are reusing the SourceManager.
702    if (hasSourceManager())
703      getSourceManager().clearIDTables();
704
705    if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
706      Act.Execute();
707      Act.EndSourceFile();
708    }
709  }
710
711  // Notify the diagnostic client that all files were processed.
712  getDiagnostics().getClient()->finish();
713
714  if (getDiagnosticOpts().ShowCarets) {
715    // We can have multiple diagnostics sharing one diagnostic client.
716    // Get the total number of warnings/errors from the client.
717    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
718    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
719
720    if (NumWarnings)
721      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
722    if (NumWarnings && NumErrors)
723      OS << " and ";
724    if (NumErrors)
725      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
726    if (NumWarnings || NumErrors)
727      OS << " generated.\n";
728  }
729
730  if (getFrontendOpts().ShowStats && hasFileManager()) {
731    getFileManager().PrintStats();
732    OS << "\n";
733  }
734
735  return !getDiagnostics().getClient()->getNumErrors();
736}
737
738/// \brief Determine the appropriate source input kind based on language
739/// options.
740static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
741  if (LangOpts.OpenCL)
742    return IK_OpenCL;
743  if (LangOpts.CUDA)
744    return IK_CUDA;
745  if (LangOpts.ObjC1)
746    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
747  return LangOpts.CPlusPlus? IK_CXX : IK_C;
748}
749
750namespace {
751  struct CompileModuleMapData {
752    CompilerInstance &Instance;
753    GenerateModuleAction &CreateModuleAction;
754  };
755}
756
757/// \brief Helper function that executes the module-generating action under
758/// a crash recovery context.
759static void doCompileMapModule(void *UserData) {
760  CompileModuleMapData &Data
761    = *reinterpret_cast<CompileModuleMapData *>(UserData);
762  Data.Instance.ExecuteAction(Data.CreateModuleAction);
763}
764
765namespace {
766  /// \brief Function object that checks with the given macro definition should
767  /// be removed, because it is one of the ignored macros.
768  class RemoveIgnoredMacro {
769    const HeaderSearchOptions &HSOpts;
770
771  public:
772    explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
773      : HSOpts(HSOpts) { }
774
775    bool operator()(const std::pair<std::string, bool> &def) const {
776      StringRef MacroDef = def.first;
777      return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
778    }
779  };
780}
781
782/// \brief Compile a module file for the given module, using the options
783/// provided by the importing compiler instance.
784static void compileModule(CompilerInstance &ImportingInstance,
785                          SourceLocation ImportLoc,
786                          Module *Module,
787                          StringRef ModuleFileName) {
788  // FIXME: have LockFileManager return an error_code so that we can
789  // avoid the mkdir when the directory already exists.
790  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
791  llvm::sys::fs::create_directories(Dir);
792
793  llvm::LockFileManager Locked(ModuleFileName);
794  switch (Locked) {
795  case llvm::LockFileManager::LFS_Error:
796    return;
797
798  case llvm::LockFileManager::LFS_Owned:
799    // We're responsible for building the module ourselves. Do so below.
800    break;
801
802  case llvm::LockFileManager::LFS_Shared:
803    // Someone else is responsible for building the module. Wait for them to
804    // finish.
805    Locked.waitForUnlock();
806    return;
807  }
808
809  ModuleMap &ModMap
810    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
811
812  // Construct a compiler invocation for creating this module.
813  IntrusiveRefCntPtr<CompilerInvocation> Invocation
814    (new CompilerInvocation(ImportingInstance.getInvocation()));
815
816  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
817
818  // For any options that aren't intended to affect how a module is built,
819  // reset them to their default values.
820  Invocation->getLangOpts()->resetNonModularOptions();
821  PPOpts.resetNonModularOptions();
822
823  // Remove any macro definitions that are explicitly ignored by the module.
824  // They aren't supposed to affect how the module is built anyway.
825  const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
826  PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
827                                     RemoveIgnoredMacro(HSOpts)),
828                      PPOpts.Macros.end());
829
830
831  // Note the name of the module we're building.
832  Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
833
834  // Make sure that the failed-module structure has been allocated in
835  // the importing instance, and propagate the pointer to the newly-created
836  // instance.
837  PreprocessorOptions &ImportingPPOpts
838    = ImportingInstance.getInvocation().getPreprocessorOpts();
839  if (!ImportingPPOpts.FailedModules)
840    ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
841  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
842
843  // If there is a module map file, build the module using the module map.
844  // Set up the inputs/outputs so that we build the module from its umbrella
845  // header.
846  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
847  FrontendOpts.OutputFile = ModuleFileName.str();
848  FrontendOpts.DisableFree = false;
849  FrontendOpts.GenerateGlobalModuleIndex = false;
850  FrontendOpts.Inputs.clear();
851  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
852
853  // Get or create the module map that we'll use to build this module.
854  SmallString<128> TempModuleMapFileName;
855  if (const FileEntry *ModuleMapFile
856                                  = ModMap.getContainingModuleMapFile(Module)) {
857    // Use the module map where this module resides.
858    FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
859                                                    IK));
860  } else {
861    // Create a temporary module map file.
862    int FD;
863    if (llvm::sys::fs::createTemporaryFile(Module->Name, "map", FD,
864                                           TempModuleMapFileName)) {
865      ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
866        << TempModuleMapFileName;
867      return;
868    }
869    // Print the module map to this file.
870    llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
871    Module->print(OS);
872    FrontendOpts.Inputs.push_back(
873      FrontendInputFile(TempModuleMapFileName.str().str(), IK));
874  }
875
876  // Don't free the remapped file buffers; they are owned by our caller.
877  PPOpts.RetainRemappedFileBuffers = true;
878
879  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
880  assert(ImportingInstance.getInvocation().getModuleHash() ==
881         Invocation->getModuleHash() && "Module hash mismatch!");
882
883  // Construct a compiler instance that will be used to actually create the
884  // module.
885  CompilerInstance Instance;
886  Instance.setInvocation(&*Invocation);
887
888  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
889                                   ImportingInstance.getDiagnosticClient()),
890                             /*ShouldOwnClient=*/true);
891
892  // Note that this module is part of the module build stack, so that we
893  // can detect cycles in the module graph.
894  Instance.createFileManager(); // FIXME: Adopt file manager from importer?
895  Instance.createSourceManager(Instance.getFileManager());
896  SourceManager &SourceMgr = Instance.getSourceManager();
897  SourceMgr.setModuleBuildStack(
898    ImportingInstance.getSourceManager().getModuleBuildStack());
899  SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
900    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
901
902
903  // Construct a module-generating action.
904  GenerateModuleAction CreateModuleAction(Module->IsSystem);
905
906  // Execute the action to actually build the module in-place. Use a separate
907  // thread so that we get a stack large enough.
908  const unsigned ThreadStackSize = 8 << 20;
909  llvm::CrashRecoveryContext CRC;
910  CompileModuleMapData Data = { Instance, CreateModuleAction };
911  CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
912
913
914  // Delete the temporary module map file.
915  // FIXME: Even though we're executing under crash protection, it would still
916  // be nice to do this with RemoveFileOnSignal when we can. However, that
917  // doesn't make sense for all clients, so clean this up manually.
918  Instance.clearOutputFiles(/*EraseFiles=*/true);
919  if (!TempModuleMapFileName.empty())
920    llvm::sys::fs::remove(TempModuleMapFileName.str());
921
922  // We've rebuilt a module. If we're allowed to generate or update the global
923  // module index, record that fact in the importing compiler instance.
924  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
925    ImportingInstance.setBuildGlobalModuleIndex(true);
926  }
927}
928
929/// \brief Diagnose differences between the current definition of the given
930/// configuration macro and the definition provided on the command line.
931static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
932                             Module *Mod, SourceLocation ImportLoc) {
933  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
934  SourceManager &SourceMgr = PP.getSourceManager();
935
936  // If this identifier has never had a macro definition, then it could
937  // not have changed.
938  if (!Id->hadMacroDefinition())
939    return;
940
941  // If this identifier does not currently have a macro definition,
942  // check whether it had one on the command line.
943  if (!Id->hasMacroDefinition()) {
944    MacroDirective::DefInfo LatestDef =
945        PP.getMacroDirectiveHistory(Id)->getDefinition();
946    for (MacroDirective::DefInfo Def = LatestDef; Def;
947           Def = Def.getPreviousDefinition()) {
948      FileID FID = SourceMgr.getFileID(Def.getLocation());
949      if (FID.isInvalid())
950        continue;
951
952      // We only care about the predefines buffer.
953      if (FID != PP.getPredefinesFileID())
954        continue;
955
956      // This macro was defined on the command line, then #undef'd later.
957      // Complain.
958      PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
959        << true << ConfigMacro << Mod->getFullModuleName();
960      if (LatestDef.isUndefined())
961        PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
962          << true;
963      return;
964    }
965
966    // Okay: no definition in the predefines buffer.
967    return;
968  }
969
970  // This identifier has a macro definition. Check whether we had a definition
971  // on the command line.
972  MacroDirective::DefInfo LatestDef =
973      PP.getMacroDirectiveHistory(Id)->getDefinition();
974  MacroDirective::DefInfo PredefinedDef;
975  for (MacroDirective::DefInfo Def = LatestDef; Def;
976         Def = Def.getPreviousDefinition()) {
977    FileID FID = SourceMgr.getFileID(Def.getLocation());
978    if (FID.isInvalid())
979      continue;
980
981    // We only care about the predefines buffer.
982    if (FID != PP.getPredefinesFileID())
983      continue;
984
985    PredefinedDef = Def;
986    break;
987  }
988
989  // If there was no definition for this macro in the predefines buffer,
990  // complain.
991  if (!PredefinedDef ||
992      (!PredefinedDef.getLocation().isValid() &&
993       PredefinedDef.getUndefLocation().isValid())) {
994    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
995      << false << ConfigMacro << Mod->getFullModuleName();
996    PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
997      << false;
998    return;
999  }
1000
1001  // If the current macro definition is the same as the predefined macro
1002  // definition, it's okay.
1003  if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
1004      LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1005                                              /*Syntactically=*/true))
1006    return;
1007
1008  // The macro definitions differ.
1009  PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1010    << false << ConfigMacro << Mod->getFullModuleName();
1011  PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1012    << false;
1013}
1014
1015/// \brief Write a new timestamp file with the given path.
1016static void writeTimestampFile(StringRef TimestampFile) {
1017  std::string ErrorInfo;
1018  llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1019                           llvm::sys::fs::F_Binary);
1020}
1021
1022/// \brief Prune the module cache of modules that haven't been accessed in
1023/// a long time.
1024static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1025  struct stat StatBuf;
1026  llvm::SmallString<128> TimestampFile;
1027  TimestampFile = HSOpts.ModuleCachePath;
1028  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1029
1030  // Try to stat() the timestamp file.
1031  if (::stat(TimestampFile.c_str(), &StatBuf)) {
1032    // If the timestamp file wasn't there, create one now.
1033    if (errno == ENOENT) {
1034      writeTimestampFile(TimestampFile);
1035    }
1036    return;
1037  }
1038
1039  // Check whether the time stamp is older than our pruning interval.
1040  // If not, do nothing.
1041  time_t TimeStampModTime = StatBuf.st_mtime;
1042  time_t CurrentTime = time(0);
1043  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1044    return;
1045
1046  // Write a new timestamp file so that nobody else attempts to prune.
1047  // There is a benign race condition here, if two Clang instances happen to
1048  // notice at the same time that the timestamp is out-of-date.
1049  writeTimestampFile(TimestampFile);
1050
1051  // Walk the entire module cache, looking for unused module files and module
1052  // indices.
1053  llvm::error_code EC;
1054  SmallString<128> ModuleCachePathNative;
1055  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1056  for (llvm::sys::fs::directory_iterator
1057         Dir(ModuleCachePathNative.str(), EC), DirEnd;
1058       Dir != DirEnd && !EC; Dir.increment(EC)) {
1059    // If we don't have a directory, there's nothing to look into.
1060    if (!llvm::sys::fs::is_directory(Dir->path()))
1061      continue;
1062
1063    // Walk all of the files within this directory.
1064    bool RemovedAllFiles = true;
1065    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1066         File != FileEnd && !EC; File.increment(EC)) {
1067      // We only care about module and global module index files.
1068      if (llvm::sys::path::extension(File->path()) != ".pcm" &&
1069          llvm::sys::path::filename(File->path()) != "modules.idx") {
1070        RemovedAllFiles = false;
1071        continue;
1072      }
1073
1074      // Look at this file. If we can't stat it, there's nothing interesting
1075      // there.
1076      if (::stat(File->path().c_str(), &StatBuf)) {
1077        RemovedAllFiles = false;
1078        continue;
1079      }
1080
1081      // If the file has been used recently enough, leave it there.
1082      time_t FileAccessTime = StatBuf.st_atime;
1083      if (CurrentTime - FileAccessTime <=
1084              time_t(HSOpts.ModuleCachePruneAfter)) {
1085        RemovedAllFiles = false;
1086        continue;
1087      }
1088
1089      // Remove the file.
1090      bool Existed;
1091      if (llvm::sys::fs::remove(File->path(), Existed) || !Existed) {
1092        RemovedAllFiles = false;
1093      }
1094    }
1095
1096    // If we removed all of the files in the directory, remove the directory
1097    // itself.
1098    if (RemovedAllFiles) {
1099      bool Existed;
1100      llvm::sys::fs::remove(Dir->path(), Existed);
1101    }
1102  }
1103}
1104
1105ModuleLoadResult
1106CompilerInstance::loadModule(SourceLocation ImportLoc,
1107                             ModuleIdPath Path,
1108                             Module::NameVisibilityKind Visibility,
1109                             bool IsInclusionDirective) {
1110  // If we've already handled this import, just return the cached result.
1111  // This one-element cache is important to eliminate redundant diagnostics
1112  // when both the preprocessor and parser see the same import declaration.
1113  if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1114    // Make the named module visible.
1115    if (LastModuleImportResult)
1116      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1117                                       ImportLoc, /*Complain=*/false);
1118    return LastModuleImportResult;
1119  }
1120
1121  // Determine what file we're searching from.
1122  StringRef ModuleName = Path[0].first->getName();
1123  SourceLocation ModuleNameLoc = Path[0].second;
1124
1125  clang::Module *Module = 0;
1126
1127  // If we don't already have information on this module, load the module now.
1128  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1129    = KnownModules.find(Path[0].first);
1130  if (Known != KnownModules.end()) {
1131    // Retrieve the cached top-level module.
1132    Module = Known->second;
1133  } else if (ModuleName == getLangOpts().CurrentModule) {
1134    // This is the module we're building.
1135    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1136    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1137  } else {
1138    // Search for a module with the given name.
1139    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1140    std::string ModuleFileName;
1141    if (Module) {
1142      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1143    } else
1144      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1145
1146    // If we don't already have an ASTReader, create one now.
1147    if (!ModuleManager) {
1148      if (!hasASTContext())
1149        createASTContext();
1150
1151      // If we're not recursively building a module, check whether we
1152      // need to prune the module cache.
1153      if (getSourceManager().getModuleBuildStack().empty() &&
1154          getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1155          getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1156        pruneModuleCache(getHeaderSearchOpts());
1157      }
1158
1159      std::string Sysroot = getHeaderSearchOpts().Sysroot;
1160      const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1161      ModuleManager = new ASTReader(getPreprocessor(), *Context,
1162                                    Sysroot.empty() ? "" : Sysroot.c_str(),
1163                                    PPOpts.DisablePCHValidation,
1164                                    /*AllowASTWithCompilerErrors=*/false,
1165                                    getFrontendOpts().UseGlobalModuleIndex);
1166      if (hasASTConsumer()) {
1167        ModuleManager->setDeserializationListener(
1168          getASTConsumer().GetASTDeserializationListener());
1169        getASTContext().setASTMutationListener(
1170          getASTConsumer().GetASTMutationListener());
1171      }
1172      OwningPtr<ExternalASTSource> Source;
1173      Source.reset(ModuleManager);
1174      getASTContext().setExternalSource(Source);
1175      if (hasSema())
1176        ModuleManager->InitializeSema(getSema());
1177      if (hasASTConsumer())
1178        ModuleManager->StartTranslationUnit(&getASTConsumer());
1179    }
1180
1181    // Try to load the module file.
1182    unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1183    switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1184                                   ImportLoc, ARRFlags)) {
1185    case ASTReader::Success:
1186      break;
1187
1188    case ASTReader::OutOfDate: {
1189      // The module file is out-of-date. Remove it, then rebuild it.
1190      bool Existed;
1191      llvm::sys::fs::remove(ModuleFileName, Existed);
1192    }
1193    // Fall through to build the module again.
1194
1195    case ASTReader::Missing: {
1196      // The module file is (now) missing. Build it.
1197
1198      // If we don't have a module, we don't know how to build the module file.
1199      // Complain and return.
1200      if (!Module) {
1201        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1202          << ModuleName
1203          << SourceRange(ImportLoc, ModuleNameLoc);
1204        ModuleBuildFailed = true;
1205        return ModuleLoadResult();
1206      }
1207
1208      // Check whether there is a cycle in the module graph.
1209      ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1210      ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1211      for (; Pos != PosEnd; ++Pos) {
1212        if (Pos->first == ModuleName)
1213          break;
1214      }
1215
1216      if (Pos != PosEnd) {
1217        SmallString<256> CyclePath;
1218        for (; Pos != PosEnd; ++Pos) {
1219          CyclePath += Pos->first;
1220          CyclePath += " -> ";
1221        }
1222        CyclePath += ModuleName;
1223
1224        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1225          << ModuleName << CyclePath;
1226        return ModuleLoadResult();
1227      }
1228
1229      // Check whether we have already attempted to build this module (but
1230      // failed).
1231      if (getPreprocessorOpts().FailedModules &&
1232          getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1233        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1234          << ModuleName
1235          << SourceRange(ImportLoc, ModuleNameLoc);
1236        ModuleBuildFailed = true;
1237        return ModuleLoadResult();
1238      }
1239
1240      // Try to compile the module.
1241      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1242
1243      // Try to read the module file, now that we've compiled it.
1244      ASTReader::ASTReadResult ReadResult
1245        = ModuleManager->ReadAST(ModuleFileName,
1246                                 serialization::MK_Module, ImportLoc,
1247                                 ASTReader::ARR_Missing);
1248      if (ReadResult != ASTReader::Success) {
1249        if (ReadResult == ASTReader::Missing) {
1250          getDiagnostics().Report(ModuleNameLoc,
1251                                  Module? diag::err_module_not_built
1252                                        : diag::err_module_not_found)
1253            << ModuleName
1254            << SourceRange(ImportLoc, ModuleNameLoc);
1255        }
1256
1257        if (getPreprocessorOpts().FailedModules)
1258          getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1259        KnownModules[Path[0].first] = 0;
1260        ModuleBuildFailed = true;
1261        return ModuleLoadResult();
1262      }
1263
1264      // Okay, we've rebuilt and now loaded the module.
1265      break;
1266    }
1267
1268    case ASTReader::VersionMismatch:
1269    case ASTReader::ConfigurationMismatch:
1270    case ASTReader::HadErrors:
1271      ModuleLoader::HadFatalFailure = true;
1272      // FIXME: The ASTReader will already have complained, but can we showhorn
1273      // that diagnostic information into a more useful form?
1274      KnownModules[Path[0].first] = 0;
1275      return ModuleLoadResult();
1276
1277    case ASTReader::Failure:
1278      ModuleLoader::HadFatalFailure = true;
1279      // Already complained, but note now that we failed.
1280      KnownModules[Path[0].first] = 0;
1281      ModuleBuildFailed = true;
1282      return ModuleLoadResult();
1283    }
1284
1285    if (!Module) {
1286      // If we loaded the module directly, without finding a module map first,
1287      // we'll have loaded the module's information from the module itself.
1288      Module = PP->getHeaderSearchInfo().getModuleMap()
1289                 .findModule((Path[0].first->getName()));
1290    }
1291
1292    // Cache the result of this top-level module lookup for later.
1293    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1294  }
1295
1296  // If we never found the module, fail.
1297  if (!Module)
1298    return ModuleLoadResult();
1299
1300  // Verify that the rest of the module path actually corresponds to
1301  // a submodule.
1302  if (Path.size() > 1) {
1303    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1304      StringRef Name = Path[I].first->getName();
1305      clang::Module *Sub = Module->findSubmodule(Name);
1306
1307      if (!Sub) {
1308        // Attempt to perform typo correction to find a module name that works.
1309        SmallVector<StringRef, 2> Best;
1310        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1311
1312        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1313                                            JEnd = Module->submodule_end();
1314             J != JEnd; ++J) {
1315          unsigned ED = Name.edit_distance((*J)->Name,
1316                                           /*AllowReplacements=*/true,
1317                                           BestEditDistance);
1318          if (ED <= BestEditDistance) {
1319            if (ED < BestEditDistance) {
1320              Best.clear();
1321              BestEditDistance = ED;
1322            }
1323
1324            Best.push_back((*J)->Name);
1325          }
1326        }
1327
1328        // If there was a clear winner, user it.
1329        if (Best.size() == 1) {
1330          getDiagnostics().Report(Path[I].second,
1331                                  diag::err_no_submodule_suggest)
1332            << Path[I].first << Module->getFullModuleName() << Best[0]
1333            << SourceRange(Path[0].second, Path[I-1].second)
1334            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1335                                            Best[0]);
1336
1337          Sub = Module->findSubmodule(Best[0]);
1338        }
1339      }
1340
1341      if (!Sub) {
1342        // No submodule by this name. Complain, and don't look for further
1343        // submodules.
1344        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1345          << Path[I].first << Module->getFullModuleName()
1346          << SourceRange(Path[0].second, Path[I-1].second);
1347        break;
1348      }
1349
1350      Module = Sub;
1351    }
1352  }
1353
1354  // Make the named module visible, if it's not already part of the module
1355  // we are parsing.
1356  if (ModuleName != getLangOpts().CurrentModule) {
1357    if (!Module->IsFromModuleFile) {
1358      // We have an umbrella header or directory that doesn't actually include
1359      // all of the headers within the directory it covers. Complain about
1360      // this missing submodule and recover by forgetting that we ever saw
1361      // this submodule.
1362      // FIXME: Should we detect this at module load time? It seems fairly
1363      // expensive (and rare).
1364      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1365        << Module->getFullModuleName()
1366        << SourceRange(Path.front().second, Path.back().second);
1367
1368      return ModuleLoadResult(0, true);
1369    }
1370
1371    // Check whether this module is available.
1372    StringRef Feature;
1373    if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1374      getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1375        << Module->getFullModuleName()
1376        << Feature
1377        << SourceRange(Path.front().second, Path.back().second);
1378      LastModuleImportLoc = ImportLoc;
1379      LastModuleImportResult = ModuleLoadResult();
1380      return ModuleLoadResult();
1381    }
1382
1383    ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1384                                     /*Complain=*/true);
1385  }
1386
1387  // Check for any configuration macros that have changed.
1388  clang::Module *TopModule = Module->getTopLevelModule();
1389  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1390    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1391                     Module, ImportLoc);
1392  }
1393
1394  // If this module import was due to an inclusion directive, create an
1395  // implicit import declaration to capture it in the AST.
1396  if (IsInclusionDirective && hasASTContext()) {
1397    TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1398    ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1399                                                     ImportLoc, Module,
1400                                                     Path.back().second);
1401    TU->addDecl(ImportD);
1402    if (Consumer)
1403      Consumer->HandleImplicitImportDecl(ImportD);
1404  }
1405
1406  LastModuleImportLoc = ImportLoc;
1407  LastModuleImportResult = ModuleLoadResult(Module, false);
1408  return LastModuleImportResult;
1409}
1410
1411void CompilerInstance::makeModuleVisible(Module *Mod,
1412                                         Module::NameVisibilityKind Visibility,
1413                                         SourceLocation ImportLoc,
1414                                         bool Complain){
1415  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1416}
1417
1418