ASTUnit.cpp revision 914ed9d30e9abf829a62aa996b083b1e47c19ff6 
1//===--- ASTUnit.cpp - ASTUnit utility ------------------------------------===//
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// ASTUnit Implementation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Frontend/ASTUnit.h"
15#include "clang/Frontend/PCHWriter.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/ASTConsumer.h"
18#include "clang/AST/DeclVisitor.h"
19#include "clang/AST/StmtVisitor.h"
20#include "clang/Driver/Compilation.h"
21#include "clang/Driver/Driver.h"
22#include "clang/Driver/Job.h"
23#include "clang/Driver/Tool.h"
24#include "clang/Frontend/CompilerInstance.h"
25#include "clang/Frontend/FrontendActions.h"
26#include "clang/Frontend/FrontendDiagnostic.h"
27#include "clang/Frontend/FrontendOptions.h"
28#include "clang/Frontend/PCHReader.h"
29#include "clang/Lex/HeaderSearch.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Basic/TargetOptions.h"
32#include "clang/Basic/TargetInfo.h"
33#include "clang/Basic/Diagnostic.h"
34#include "llvm/Support/MemoryBuffer.h"
35#include "llvm/System/Host.h"
36#include "llvm/System/Path.h"
37#include "llvm/Support/raw_ostream.h"
38#include "llvm/Support/Timer.h"
39#include <cstdlib>
40#include <cstdio>
41#include <sys/stat.h>
42using namespace clang;
43
44/// \brief After failing to build a precompiled preamble (due to
45/// errors in the source that occurs in the preamble), the number of
46/// reparses during which we'll skip even trying to precompile the
47/// preamble.
48const unsigned DefaultPreambleRebuildInterval = 5;
49
50ASTUnit::ASTUnit(bool _MainFileIsAST)
51  : CaptureDiagnostics(false), MainFileIsAST(_MainFileIsAST),
52    CompleteTranslationUnit(true), ConcurrencyCheckValue(CheckUnlocked),
53    PreambleRebuildCounter(0), SavedMainFileBuffer(0) {
54}
55
56ASTUnit::~ASTUnit() {
57  ConcurrencyCheckValue = CheckLocked;
58  CleanTemporaryFiles();
59  if (!PreambleFile.empty())
60    llvm::sys::Path(PreambleFile).eraseFromDisk();
61
62  // Free the buffers associated with remapped files. We are required to
63  // perform this operation here because we explicitly request that the
64  // compiler instance *not* free these buffers for each invocation of the
65  // parser.
66  if (Invocation.get()) {
67    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
68    for (PreprocessorOptions::remapped_file_buffer_iterator
69           FB = PPOpts.remapped_file_buffer_begin(),
70           FBEnd = PPOpts.remapped_file_buffer_end();
71         FB != FBEnd;
72         ++FB)
73      delete FB->second;
74  }
75
76  delete SavedMainFileBuffer;
77
78  for (unsigned I = 0, N = Timers.size(); I != N; ++I)
79    delete Timers[I];
80}
81
82void ASTUnit::CleanTemporaryFiles() {
83  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
84    TemporaryFiles[I].eraseFromDisk();
85  TemporaryFiles.clear();
86}
87
88namespace {
89
90/// \brief Gathers information from PCHReader that will be used to initialize
91/// a Preprocessor.
92class PCHInfoCollector : public PCHReaderListener {
93  LangOptions &LangOpt;
94  HeaderSearch &HSI;
95  std::string &TargetTriple;
96  std::string &Predefines;
97  unsigned &Counter;
98
99  unsigned NumHeaderInfos;
100
101public:
102  PCHInfoCollector(LangOptions &LangOpt, HeaderSearch &HSI,
103                   std::string &TargetTriple, std::string &Predefines,
104                   unsigned &Counter)
105    : LangOpt(LangOpt), HSI(HSI), TargetTriple(TargetTriple),
106      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0) {}
107
108  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
109    LangOpt = LangOpts;
110    return false;
111  }
112
113  virtual bool ReadTargetTriple(llvm::StringRef Triple) {
114    TargetTriple = Triple;
115    return false;
116  }
117
118  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
119                                    llvm::StringRef OriginalFileName,
120                                    std::string &SuggestedPredefines) {
121    Predefines = Buffers[0].Data;
122    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
123      Predefines += Buffers[I].Data;
124    }
125    return false;
126  }
127
128  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
129    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
130  }
131
132  virtual void ReadCounter(unsigned Value) {
133    Counter = Value;
134  }
135};
136
137class StoredDiagnosticClient : public DiagnosticClient {
138  llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags;
139
140public:
141  explicit StoredDiagnosticClient(
142                          llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
143    : StoredDiags(StoredDiags) { }
144
145  virtual void HandleDiagnostic(Diagnostic::Level Level,
146                                const DiagnosticInfo &Info);
147};
148
149/// \brief RAII object that optionally captures diagnostics, if
150/// there is no diagnostic client to capture them already.
151class CaptureDroppedDiagnostics {
152  Diagnostic &Diags;
153  StoredDiagnosticClient Client;
154  DiagnosticClient *PreviousClient;
155
156public:
157  CaptureDroppedDiagnostics(bool RequestCapture, Diagnostic &Diags,
158                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
159    : Diags(Diags), Client(StoredDiags), PreviousClient(Diags.getClient())
160  {
161    if (RequestCapture || Diags.getClient() == 0)
162      Diags.setClient(&Client);
163  }
164
165  ~CaptureDroppedDiagnostics() {
166    Diags.setClient(PreviousClient);
167  }
168};
169
170} // anonymous namespace
171
172void StoredDiagnosticClient::HandleDiagnostic(Diagnostic::Level Level,
173                                              const DiagnosticInfo &Info) {
174  StoredDiags.push_back(StoredDiagnostic(Level, Info));
175}
176
177const std::string &ASTUnit::getOriginalSourceFileName() {
178  return OriginalSourceFile;
179}
180
181const std::string &ASTUnit::getPCHFileName() {
182  assert(isMainFileAST() && "Not an ASTUnit from a PCH file!");
183  return static_cast<PCHReader *>(Ctx->getExternalSource())->getFileName();
184}
185
186ASTUnit *ASTUnit::LoadFromPCHFile(const std::string &Filename,
187                                  llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
188                                  bool OnlyLocalDecls,
189                                  RemappedFile *RemappedFiles,
190                                  unsigned NumRemappedFiles,
191                                  bool CaptureDiagnostics) {
192  llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
193
194  if (!Diags.getPtr()) {
195    // No diagnostics engine was provided, so create our own diagnostics object
196    // with the default options.
197    DiagnosticOptions DiagOpts;
198    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
199  }
200
201  AST->CaptureDiagnostics = CaptureDiagnostics;
202  AST->OnlyLocalDecls = OnlyLocalDecls;
203  AST->Diagnostics = Diags;
204  AST->FileMgr.reset(new FileManager);
205  AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics()));
206  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
207
208  // If requested, capture diagnostics in the ASTUnit.
209  CaptureDroppedDiagnostics Capture(CaptureDiagnostics, AST->getDiagnostics(),
210                                    AST->StoredDiagnostics);
211
212  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
213    // Create the file entry for the file that we're mapping from.
214    const FileEntry *FromFile
215      = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
216                                    RemappedFiles[I].second->getBufferSize(),
217                                             0);
218    if (!FromFile) {
219      AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
220        << RemappedFiles[I].first;
221      delete RemappedFiles[I].second;
222      continue;
223    }
224
225    // Override the contents of the "from" file with the contents of
226    // the "to" file.
227    AST->getSourceManager().overrideFileContents(FromFile,
228                                                 RemappedFiles[I].second);
229  }
230
231  // Gather Info for preprocessor construction later on.
232
233  LangOptions LangInfo;
234  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
235  std::string TargetTriple;
236  std::string Predefines;
237  unsigned Counter;
238
239  llvm::OwningPtr<PCHReader> Reader;
240
241  Reader.reset(new PCHReader(AST->getSourceManager(), AST->getFileManager(),
242                             AST->getDiagnostics()));
243  Reader->setListener(new PCHInfoCollector(LangInfo, HeaderInfo, TargetTriple,
244                                           Predefines, Counter));
245
246  switch (Reader->ReadPCH(Filename)) {
247  case PCHReader::Success:
248    break;
249
250  case PCHReader::Failure:
251  case PCHReader::IgnorePCH:
252    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
253    return NULL;
254  }
255
256  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
257
258  // PCH loaded successfully. Now create the preprocessor.
259
260  // Get information about the target being compiled for.
261  //
262  // FIXME: This is broken, we should store the TargetOptions in the PCH.
263  TargetOptions TargetOpts;
264  TargetOpts.ABI = "";
265  TargetOpts.CXXABI = "itanium";
266  TargetOpts.CPU = "";
267  TargetOpts.Features.clear();
268  TargetOpts.Triple = TargetTriple;
269  AST->Target.reset(TargetInfo::CreateTargetInfo(AST->getDiagnostics(),
270                                                 TargetOpts));
271  AST->PP.reset(new Preprocessor(AST->getDiagnostics(), LangInfo,
272                                 *AST->Target.get(),
273                                 AST->getSourceManager(), HeaderInfo));
274  Preprocessor &PP = *AST->PP.get();
275
276  PP.setPredefines(Reader->getSuggestedPredefines());
277  PP.setCounterValue(Counter);
278  Reader->setPreprocessor(PP);
279
280  // Create and initialize the ASTContext.
281
282  AST->Ctx.reset(new ASTContext(LangInfo,
283                                AST->getSourceManager(),
284                                *AST->Target.get(),
285                                PP.getIdentifierTable(),
286                                PP.getSelectorTable(),
287                                PP.getBuiltinInfo(),
288                                /* size_reserve = */0));
289  ASTContext &Context = *AST->Ctx.get();
290
291  Reader->InitializeContext(Context);
292
293  // Attach the PCH reader to the AST context as an external AST
294  // source, so that declarations will be deserialized from the
295  // PCH file as needed.
296  PCHReader *ReaderPtr = Reader.get();
297  llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
298  Context.setExternalSource(Source);
299
300  // Create an AST consumer, even though it isn't used.
301  AST->Consumer.reset(new ASTConsumer);
302
303  // Create a semantic analysis object and tell the PCH reader about it.
304  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
305  AST->TheSema->Initialize();
306  ReaderPtr->InitializeSema(*AST->TheSema);
307
308  return AST.take();
309}
310
311namespace {
312
313class TopLevelDeclTrackerConsumer : public ASTConsumer {
314  ASTUnit &Unit;
315
316public:
317  TopLevelDeclTrackerConsumer(ASTUnit &_Unit) : Unit(_Unit) {}
318
319  void HandleTopLevelDecl(DeclGroupRef D) {
320    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
321      Decl *D = *it;
322      // FIXME: Currently ObjC method declarations are incorrectly being
323      // reported as top-level declarations, even though their DeclContext
324      // is the containing ObjC @interface/@implementation.  This is a
325      // fundamental problem in the parser right now.
326      if (isa<ObjCMethodDecl>(D))
327        continue;
328      Unit.addTopLevelDecl(D);
329    }
330  }
331
332  // We're not interested in "interesting" decls.
333  void HandleInterestingDecl(DeclGroupRef) {}
334};
335
336class TopLevelDeclTrackerAction : public ASTFrontendAction {
337public:
338  ASTUnit &Unit;
339
340  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
341                                         llvm::StringRef InFile) {
342    return new TopLevelDeclTrackerConsumer(Unit);
343  }
344
345public:
346  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
347
348  virtual bool hasCodeCompletionSupport() const { return false; }
349  virtual bool usesCompleteTranslationUnit()  {
350    return Unit.isCompleteTranslationUnit();
351  }
352};
353
354class PrecompilePreambleConsumer : public PCHGenerator {
355  ASTUnit &Unit;
356  std::vector<Decl *> TopLevelDecls;
357
358public:
359  PrecompilePreambleConsumer(ASTUnit &Unit,
360                             const Preprocessor &PP, bool Chaining,
361                             const char *isysroot, llvm::raw_ostream *Out)
362    : PCHGenerator(PP, Chaining, isysroot, Out), Unit(Unit) { }
363
364  virtual void HandleTopLevelDecl(DeclGroupRef D) {
365    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
366      Decl *D = *it;
367      // FIXME: Currently ObjC method declarations are incorrectly being
368      // reported as top-level declarations, even though their DeclContext
369      // is the containing ObjC @interface/@implementation.  This is a
370      // fundamental problem in the parser right now.
371      if (isa<ObjCMethodDecl>(D))
372        continue;
373      TopLevelDecls.push_back(D);
374    }
375  }
376
377  virtual void HandleTranslationUnit(ASTContext &Ctx) {
378    PCHGenerator::HandleTranslationUnit(Ctx);
379    if (!Unit.getDiagnostics().hasErrorOccurred()) {
380      // Translate the top-level declarations we captured during
381      // parsing into declaration IDs in the precompiled
382      // preamble. This will allow us to deserialize those top-level
383      // declarations when requested.
384      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
385        Unit.addTopLevelDeclFromPreamble(
386                                      getWriter().getDeclID(TopLevelDecls[I]));
387    }
388  }
389};
390
391class PrecompilePreambleAction : public ASTFrontendAction {
392  ASTUnit &Unit;
393
394public:
395  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
396
397  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
398                                         llvm::StringRef InFile) {
399    std::string Sysroot;
400    llvm::raw_ostream *OS = 0;
401    bool Chaining;
402    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
403                                                       OS, Chaining))
404      return 0;
405
406    const char *isysroot = CI.getFrontendOpts().RelocatablePCH ?
407                             Sysroot.c_str() : 0;
408    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Chaining,
409                                          isysroot, OS);
410  }
411
412  virtual bool hasCodeCompletionSupport() const { return false; }
413  virtual bool hasASTFileSupport() const { return false; }
414  virtual bool usesCompleteTranslationUnit() { return false; }
415};
416
417}
418
419/// Parse the source file into a translation unit using the given compiler
420/// invocation, replacing the current translation unit.
421///
422/// \returns True if a failure occurred that causes the ASTUnit not to
423/// contain any translation-unit information, false otherwise.
424bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
425  delete SavedMainFileBuffer;
426  SavedMainFileBuffer = 0;
427
428  if (!Invocation.get())
429    return true;
430
431  // Create the compiler instance to use for building the AST.
432  CompilerInstance Clang;
433  Clang.setInvocation(Invocation.take());
434  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
435
436  // Set up diagnostics, capturing any diagnostics that would
437  // otherwise be dropped.
438  Clang.setDiagnostics(&getDiagnostics());
439  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
440                                    getDiagnostics(),
441                                    StoredDiagnostics);
442  Clang.setDiagnosticClient(getDiagnostics().getClient());
443
444  // Create the target instance.
445  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
446                                               Clang.getTargetOpts()));
447  if (!Clang.hasTarget()) {
448    Clang.takeDiagnosticClient();
449    return true;
450  }
451
452  // Inform the target of the language options.
453  //
454  // FIXME: We shouldn't need to do this, the target should be immutable once
455  // created. This complexity should be lifted elsewhere.
456  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
457
458  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
459         "Invocation must have exactly one source file!");
460  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
461         "FIXME: AST inputs not yet supported here!");
462  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
463         "IR inputs not support here!");
464
465  // Configure the various subsystems.
466  // FIXME: Should we retain the previous file manager?
467  FileMgr.reset(new FileManager);
468  SourceMgr.reset(new SourceManager(getDiagnostics()));
469  TheSema.reset();
470  Ctx.reset();
471  PP.reset();
472
473  // Clear out old caches and data.
474  TopLevelDecls.clear();
475  CleanTemporaryFiles();
476  PreprocessedEntitiesByFile.clear();
477
478  if (!OverrideMainBuffer)
479    StoredDiagnostics.clear();
480
481  // Create a file manager object to provide access to and cache the filesystem.
482  Clang.setFileManager(&getFileManager());
483
484  // Create the source manager.
485  Clang.setSourceManager(&getSourceManager());
486
487  // If the main file has been overridden due to the use of a preamble,
488  // make that override happen and introduce the preamble.
489  PreprocessorOptions &PreprocessorOpts = Clang.getPreprocessorOpts();
490  std::string PriorImplicitPCHInclude;
491  if (OverrideMainBuffer) {
492    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
493    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
494    PreprocessorOpts.PrecompiledPreambleBytes.second
495                                                    = PreambleEndsAtStartOfLine;
496    PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
497    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
498    PreprocessorOpts.DisablePCHValidation = true;
499
500    // Keep track of the override buffer;
501    SavedMainFileBuffer = OverrideMainBuffer;
502
503    // The stored diagnostic has the old source manager in it; update
504    // the locations to refer into the new source manager. Since we've
505    // been careful to make sure that the source manager's state
506    // before and after are identical, so that we can reuse the source
507    // location itself.
508    for (unsigned I = 0, N = StoredDiagnostics.size(); I != N; ++I) {
509      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
510                        getSourceManager());
511      StoredDiagnostics[I].setLocation(Loc);
512    }
513  }
514
515  llvm::OwningPtr<TopLevelDeclTrackerAction> Act;
516  Act.reset(new TopLevelDeclTrackerAction(*this));
517  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
518                            Clang.getFrontendOpts().Inputs[0].first))
519    goto error;
520
521  Act->Execute();
522
523  // Steal the created target, context, and preprocessor, and take back the
524  // source and file managers.
525  TheSema.reset(Clang.takeSema());
526  Consumer.reset(Clang.takeASTConsumer());
527  Ctx.reset(Clang.takeASTContext());
528  PP.reset(Clang.takePreprocessor());
529  Clang.takeSourceManager();
530  Clang.takeFileManager();
531  Target.reset(Clang.takeTarget());
532
533  Act->EndSourceFile();
534
535  // Remove the overridden buffer we used for the preamble.
536  if (OverrideMainBuffer) {
537    PreprocessorOpts.eraseRemappedFile(
538                               PreprocessorOpts.remapped_file_buffer_end() - 1);
539    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
540  }
541
542  Clang.takeDiagnosticClient();
543
544  Invocation.reset(Clang.takeInvocation());
545  return false;
546
547error:
548  // Remove the overridden buffer we used for the preamble.
549  if (OverrideMainBuffer) {
550    PreprocessorOpts.eraseRemappedFile(
551                               PreprocessorOpts.remapped_file_buffer_end() - 1);
552    PreprocessorOpts.DisablePCHValidation = true;
553    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
554  }
555
556  Clang.takeSourceManager();
557  Clang.takeFileManager();
558  Clang.takeDiagnosticClient();
559  Invocation.reset(Clang.takeInvocation());
560  return true;
561}
562
563/// \brief Simple function to retrieve a path for a preamble precompiled header.
564static std::string GetPreamblePCHPath() {
565  // FIXME: This is lame; sys::Path should provide this function (in particular,
566  // it should know how to find the temporary files dir).
567  // FIXME: This is really lame. I copied this code from the Driver!
568  std::string Error;
569  const char *TmpDir = ::getenv("TMPDIR");
570  if (!TmpDir)
571    TmpDir = ::getenv("TEMP");
572  if (!TmpDir)
573    TmpDir = ::getenv("TMP");
574  if (!TmpDir)
575    TmpDir = "/tmp";
576  llvm::sys::Path P(TmpDir);
577  P.appendComponent("preamble");
578  P.appendSuffix("pch");
579  if (P.createTemporaryFileOnDisk())
580    return std::string();
581
582  fprintf(stderr, "Preamble file: %s\n", P.str().c_str());
583  return P.str();
584}
585
586/// \brief Compute the preamble for the main file, providing the source buffer
587/// that corresponds to the main file along with a pair (bytes, start-of-line)
588/// that describes the preamble.
589std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
590ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
591                         unsigned MaxLines, bool &CreatedBuffer) {
592  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
593  PreprocessorOptions &PreprocessorOpts
594    = Invocation.getPreprocessorOpts();
595  CreatedBuffer = false;
596
597  // Try to determine if the main file has been remapped, either from the
598  // command line (to another file) or directly through the compiler invocation
599  // (to a memory buffer).
600  llvm::MemoryBuffer *Buffer = 0;
601  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
602  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
603    // Check whether there is a file-file remapping of the main file
604    for (PreprocessorOptions::remapped_file_iterator
605          M = PreprocessorOpts.remapped_file_begin(),
606          E = PreprocessorOpts.remapped_file_end();
607         M != E;
608         ++M) {
609      llvm::sys::PathWithStatus MPath(M->first);
610      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
611        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
612          // We found a remapping. Try to load the resulting, remapped source.
613          if (CreatedBuffer) {
614            delete Buffer;
615            CreatedBuffer = false;
616          }
617
618          Buffer = llvm::MemoryBuffer::getFile(M->second);
619          if (!Buffer)
620            return std::make_pair((llvm::MemoryBuffer*)0,
621                                  std::make_pair(0, true));
622          CreatedBuffer = true;
623
624          // Remove this remapping. We've captured the buffer already.
625          M = PreprocessorOpts.eraseRemappedFile(M);
626          E = PreprocessorOpts.remapped_file_end();
627        }
628      }
629    }
630
631    // Check whether there is a file-buffer remapping. It supercedes the
632    // file-file remapping.
633    for (PreprocessorOptions::remapped_file_buffer_iterator
634           M = PreprocessorOpts.remapped_file_buffer_begin(),
635           E = PreprocessorOpts.remapped_file_buffer_end();
636         M != E;
637         ++M) {
638      llvm::sys::PathWithStatus MPath(M->first);
639      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
640        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
641          // We found a remapping.
642          if (CreatedBuffer) {
643            delete Buffer;
644            CreatedBuffer = false;
645          }
646
647          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
648
649          // Remove this remapping. We've captured the buffer already.
650          M = PreprocessorOpts.eraseRemappedFile(M);
651          E = PreprocessorOpts.remapped_file_buffer_end();
652        }
653      }
654    }
655  }
656
657  // If the main source file was not remapped, load it now.
658  if (!Buffer) {
659    Buffer = llvm::MemoryBuffer::getFile(FrontendOpts.Inputs[0].second);
660    if (!Buffer)
661      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
662
663    CreatedBuffer = true;
664  }
665
666  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer, MaxLines));
667}
668
669static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
670                                                      bool DeleteOld,
671                                                      unsigned NewSize,
672                                                      llvm::StringRef NewName) {
673  llvm::MemoryBuffer *Result
674    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
675  memcpy(const_cast<char*>(Result->getBufferStart()),
676         Old->getBufferStart(), Old->getBufferSize());
677  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
678         ' ', NewSize - Old->getBufferSize() - 1);
679  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
680
681  if (DeleteOld)
682    delete Old;
683
684  return Result;
685}
686
687/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
688/// the source file.
689///
690/// This routine will compute the preamble of the main source file. If a
691/// non-trivial preamble is found, it will precompile that preamble into a
692/// precompiled header so that the precompiled preamble can be used to reduce
693/// reparsing time. If a precompiled preamble has already been constructed,
694/// this routine will determine if it is still valid and, if so, avoid
695/// rebuilding the precompiled preamble.
696///
697/// \param AllowRebuild When true (the default), this routine is
698/// allowed to rebuild the precompiled preamble if it is found to be
699/// out-of-date.
700///
701/// \param MaxLines When non-zero, the maximum number of lines that
702/// can occur within the preamble.
703///
704/// \returns If the precompiled preamble can be used, returns a newly-allocated
705/// buffer that should be used in place of the main file when doing so.
706/// Otherwise, returns a NULL pointer.
707llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
708                                                           bool AllowRebuild,
709                                                           unsigned MaxLines) {
710  CompilerInvocation PreambleInvocation(*Invocation);
711  FrontendOptions &FrontendOpts = PreambleInvocation.getFrontendOpts();
712  PreprocessorOptions &PreprocessorOpts
713    = PreambleInvocation.getPreprocessorOpts();
714
715  bool CreatedPreambleBuffer = false;
716  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
717    = ComputePreamble(PreambleInvocation, MaxLines, CreatedPreambleBuffer);
718
719  if (!NewPreamble.second.first) {
720    // We couldn't find a preamble in the main source. Clear out the current
721    // preamble, if we have one. It's obviously no good any more.
722    Preamble.clear();
723    if (!PreambleFile.empty()) {
724      llvm::sys::Path(PreambleFile).eraseFromDisk();
725      PreambleFile.clear();
726    }
727    if (CreatedPreambleBuffer)
728      delete NewPreamble.first;
729
730    // The next time we actually see a preamble, precompile it.
731    PreambleRebuildCounter = 1;
732    return 0;
733  }
734
735  if (!Preamble.empty()) {
736    // We've previously computed a preamble. Check whether we have the same
737    // preamble now that we did before, and that there's enough space in
738    // the main-file buffer within the precompiled preamble to fit the
739    // new main file.
740    if (Preamble.size() == NewPreamble.second.first &&
741        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
742        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
743        memcmp(&Preamble[0], NewPreamble.first->getBufferStart(),
744               NewPreamble.second.first) == 0) {
745      // The preamble has not changed. We may be able to re-use the precompiled
746      // preamble.
747
748      // Check that none of the files used by the preamble have changed.
749      bool AnyFileChanged = false;
750
751      // First, make a record of those files that have been overridden via
752      // remapping or unsaved_files.
753      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
754      for (PreprocessorOptions::remapped_file_iterator
755                R = PreprocessorOpts.remapped_file_begin(),
756             REnd = PreprocessorOpts.remapped_file_end();
757           !AnyFileChanged && R != REnd;
758           ++R) {
759        struct stat StatBuf;
760        if (stat(R->second.c_str(), &StatBuf)) {
761          // If we can't stat the file we're remapping to, assume that something
762          // horrible happened.
763          AnyFileChanged = true;
764          break;
765        }
766
767        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
768                                                   StatBuf.st_mtime);
769      }
770      for (PreprocessorOptions::remapped_file_buffer_iterator
771                R = PreprocessorOpts.remapped_file_buffer_begin(),
772             REnd = PreprocessorOpts.remapped_file_buffer_end();
773           !AnyFileChanged && R != REnd;
774           ++R) {
775        // FIXME: Should we actually compare the contents of file->buffer
776        // remappings?
777        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
778                                                   0);
779      }
780
781      // Check whether anything has changed.
782      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
783             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
784           !AnyFileChanged && F != FEnd;
785           ++F) {
786        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
787          = OverriddenFiles.find(F->first());
788        if (Overridden != OverriddenFiles.end()) {
789          // This file was remapped; check whether the newly-mapped file
790          // matches up with the previous mapping.
791          if (Overridden->second != F->second)
792            AnyFileChanged = true;
793          continue;
794        }
795
796        // The file was not remapped; check whether it has changed on disk.
797        struct stat StatBuf;
798        if (stat(F->first(), &StatBuf)) {
799          // If we can't stat the file, assume that something horrible happened.
800          AnyFileChanged = true;
801        } else if (StatBuf.st_size != F->second.first ||
802                   StatBuf.st_mtime != F->second.second)
803          AnyFileChanged = true;
804      }
805
806      if (!AnyFileChanged) {
807        // Okay! We can re-use the precompiled preamble.
808
809        // Set the state of the diagnostic object to mimic its state
810        // after parsing the preamble.
811        getDiagnostics().Reset();
812        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
813        if (StoredDiagnostics.size() > NumStoredDiagnosticsInPreamble)
814          StoredDiagnostics.erase(
815            StoredDiagnostics.begin() + NumStoredDiagnosticsInPreamble,
816                                  StoredDiagnostics.end());
817
818        // Create a version of the main file buffer that is padded to
819        // buffer size we reserved when creating the preamble.
820        return CreatePaddedMainFileBuffer(NewPreamble.first,
821                                          CreatedPreambleBuffer,
822                                          PreambleReservedSize,
823                                          FrontendOpts.Inputs[0].second);
824      }
825    }
826
827    // If we aren't allowed to rebuild the precompiled preamble, just
828    // return now.
829    if (!AllowRebuild)
830      return 0;
831
832    // We can't reuse the previously-computed preamble. Build a new one.
833    Preamble.clear();
834    llvm::sys::Path(PreambleFile).eraseFromDisk();
835    PreambleRebuildCounter = 1;
836  } else if (!AllowRebuild) {
837    // We aren't allowed to rebuild the precompiled preamble; just
838    // return now.
839    return 0;
840  }
841
842  // If the preamble rebuild counter > 1, it's because we previously
843  // failed to build a preamble and we're not yet ready to try
844  // again. Decrement the counter and return a failure.
845  if (PreambleRebuildCounter > 1) {
846    --PreambleRebuildCounter;
847    return 0;
848  }
849
850  // We did not previously compute a preamble, or it can't be reused anyway.
851  llvm::Timer *PreambleTimer = 0;
852  if (TimerGroup.get()) {
853    PreambleTimer = new llvm::Timer("Precompiling preamble", *TimerGroup);
854    PreambleTimer->startTimer();
855    Timers.push_back(PreambleTimer);
856  }
857
858  // Create a new buffer that stores the preamble. The buffer also contains
859  // extra space for the original contents of the file (which will be present
860  // when we actually parse the file) along with more room in case the file
861  // grows.
862  PreambleReservedSize = NewPreamble.first->getBufferSize();
863  if (PreambleReservedSize < 4096)
864    PreambleReservedSize = 8191;
865  else
866    PreambleReservedSize *= 2;
867
868  // Save the preamble text for later; we'll need to compare against it for
869  // subsequent reparses.
870  Preamble.assign(NewPreamble.first->getBufferStart(),
871                  NewPreamble.first->getBufferStart()
872                                                  + NewPreamble.second.first);
873  PreambleEndsAtStartOfLine = NewPreamble.second.second;
874
875  llvm::MemoryBuffer *PreambleBuffer
876    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
877                                                FrontendOpts.Inputs[0].second);
878  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
879         NewPreamble.first->getBufferStart(), Preamble.size());
880  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
881         ' ', PreambleReservedSize - Preamble.size() - 1);
882  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
883
884  // Remap the main source file to the preamble buffer.
885  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
886  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
887
888  // Tell the compiler invocation to generate a temporary precompiled header.
889  FrontendOpts.ProgramAction = frontend::GeneratePCH;
890  // FIXME: Set ChainedPCH unconditionally, once it is ready.
891  if (::getenv("LIBCLANG_CHAINING"))
892    FrontendOpts.ChainedPCH = true;
893  // FIXME: Generate the precompiled header into memory?
894  FrontendOpts.OutputFile = GetPreamblePCHPath();
895
896  // Create the compiler instance to use for building the precompiled preamble.
897  CompilerInstance Clang;
898  Clang.setInvocation(&PreambleInvocation);
899  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
900
901  // Set up diagnostics, capturing all of the diagnostics produced.
902  Clang.setDiagnostics(&getDiagnostics());
903  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
904                                    getDiagnostics(),
905                                    StoredDiagnostics);
906  Clang.setDiagnosticClient(getDiagnostics().getClient());
907
908  // Create the target instance.
909  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
910                                               Clang.getTargetOpts()));
911  if (!Clang.hasTarget()) {
912    Clang.takeDiagnosticClient();
913    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
914    Preamble.clear();
915    if (CreatedPreambleBuffer)
916      delete NewPreamble.first;
917    if (PreambleTimer)
918      PreambleTimer->stopTimer();
919    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
920    return 0;
921  }
922
923  // Inform the target of the language options.
924  //
925  // FIXME: We shouldn't need to do this, the target should be immutable once
926  // created. This complexity should be lifted elsewhere.
927  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
928
929  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
930         "Invocation must have exactly one source file!");
931  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
932         "FIXME: AST inputs not yet supported here!");
933  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
934         "IR inputs not support here!");
935
936  // Clear out old caches and data.
937  StoredDiagnostics.clear();
938  TopLevelDecls.clear();
939  TopLevelDeclsInPreamble.clear();
940
941  // Create a file manager object to provide access to and cache the filesystem.
942  Clang.setFileManager(new FileManager);
943
944  // Create the source manager.
945  Clang.setSourceManager(new SourceManager(getDiagnostics()));
946
947  llvm::OwningPtr<PrecompilePreambleAction> Act;
948  Act.reset(new PrecompilePreambleAction(*this));
949  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
950                            Clang.getFrontendOpts().Inputs[0].first)) {
951    Clang.takeDiagnosticClient();
952    Clang.takeInvocation();
953    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
954    Preamble.clear();
955    if (CreatedPreambleBuffer)
956      delete NewPreamble.first;
957    if (PreambleTimer)
958      PreambleTimer->stopTimer();
959    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
960
961    return 0;
962  }
963
964  Act->Execute();
965  Act->EndSourceFile();
966  Clang.takeDiagnosticClient();
967  Clang.takeInvocation();
968
969  if (Diagnostics->hasErrorOccurred()) {
970    // There were errors parsing the preamble, so no precompiled header was
971    // generated. Forget that we even tried.
972    // FIXME: Should we leave a note for ourselves to try again?
973    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
974    Preamble.clear();
975    if (CreatedPreambleBuffer)
976      delete NewPreamble.first;
977    if (PreambleTimer)
978      PreambleTimer->stopTimer();
979    TopLevelDeclsInPreamble.clear();
980    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
981    return 0;
982  }
983
984  // Keep track of the preamble we precompiled.
985  PreambleFile = FrontendOpts.OutputFile;
986  NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
987  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
988
989  // Keep track of all of the files that the source manager knows about,
990  // so we can verify whether they have changed or not.
991  FilesInPreamble.clear();
992  SourceManager &SourceMgr = Clang.getSourceManager();
993  const llvm::MemoryBuffer *MainFileBuffer
994    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
995  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
996                                     FEnd = SourceMgr.fileinfo_end();
997       F != FEnd;
998       ++F) {
999    const FileEntry *File = F->second->Entry;
1000    if (!File || F->second->getRawBuffer() == MainFileBuffer)
1001      continue;
1002
1003    FilesInPreamble[File->getName()]
1004      = std::make_pair(F->second->getSize(), File->getModificationTime());
1005  }
1006
1007  if (PreambleTimer)
1008    PreambleTimer->stopTimer();
1009
1010  PreambleRebuildCounter = 1;
1011  return CreatePaddedMainFileBuffer(NewPreamble.first,
1012                                    CreatedPreambleBuffer,
1013                                    PreambleReservedSize,
1014                                    FrontendOpts.Inputs[0].second);
1015}
1016
1017void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1018  std::vector<Decl *> Resolved;
1019  Resolved.reserve(TopLevelDeclsInPreamble.size());
1020  ExternalASTSource &Source = *getASTContext().getExternalSource();
1021  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1022    // Resolve the declaration ID to an actual declaration, possibly
1023    // deserializing the declaration in the process.
1024    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1025    if (D)
1026      Resolved.push_back(D);
1027  }
1028  TopLevelDeclsInPreamble.clear();
1029  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1030}
1031
1032unsigned ASTUnit::getMaxPCHLevel() const {
1033  if (!getOnlyLocalDecls())
1034    return Decl::MaxPCHLevel;
1035
1036  unsigned Result = 0;
1037  if (isMainFileAST() || SavedMainFileBuffer)
1038    ++Result;
1039  return Result;
1040}
1041
1042ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1043                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1044                                             bool OnlyLocalDecls,
1045                                             bool CaptureDiagnostics,
1046                                             bool PrecompilePreamble,
1047                                             bool CompleteTranslationUnit) {
1048  if (!Diags.getPtr()) {
1049    // No diagnostics engine was provided, so create our own diagnostics object
1050    // with the default options.
1051    DiagnosticOptions DiagOpts;
1052    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1053  }
1054
1055  // Create the AST unit.
1056  llvm::OwningPtr<ASTUnit> AST;
1057  AST.reset(new ASTUnit(false));
1058  AST->Diagnostics = Diags;
1059  AST->CaptureDiagnostics = CaptureDiagnostics;
1060  AST->OnlyLocalDecls = OnlyLocalDecls;
1061  AST->CompleteTranslationUnit = CompleteTranslationUnit;
1062  AST->Invocation.reset(CI);
1063  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1064
1065  if (getenv("LIBCLANG_TIMING"))
1066    AST->TimerGroup.reset(
1067                  new llvm::TimerGroup(CI->getFrontendOpts().Inputs[0].second));
1068
1069
1070  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1071  // FIXME: When C++ PCH is ready, allow use of it for a precompiled preamble.
1072  if (PrecompilePreamble && !CI->getLangOpts().CPlusPlus) {
1073    AST->PreambleRebuildCounter = 1;
1074    OverrideMainBuffer = AST->getMainBufferWithPrecompiledPreamble();
1075  }
1076
1077  llvm::Timer *ParsingTimer = 0;
1078  if (AST->TimerGroup.get()) {
1079    ParsingTimer = new llvm::Timer("Initial parse", *AST->TimerGroup);
1080    ParsingTimer->startTimer();
1081    AST->Timers.push_back(ParsingTimer);
1082  }
1083
1084  bool Failed = AST->Parse(OverrideMainBuffer);
1085  if (ParsingTimer)
1086    ParsingTimer->stopTimer();
1087
1088  return Failed? 0 : AST.take();
1089}
1090
1091ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1092                                      const char **ArgEnd,
1093                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1094                                      llvm::StringRef ResourceFilesPath,
1095                                      bool OnlyLocalDecls,
1096                                      RemappedFile *RemappedFiles,
1097                                      unsigned NumRemappedFiles,
1098                                      bool CaptureDiagnostics,
1099                                      bool PrecompilePreamble,
1100                                      bool CompleteTranslationUnit) {
1101  if (!Diags.getPtr()) {
1102    // No diagnostics engine was provided, so create our own diagnostics object
1103    // with the default options.
1104    DiagnosticOptions DiagOpts;
1105    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1106  }
1107
1108  llvm::SmallVector<const char *, 16> Args;
1109  Args.push_back("<clang>"); // FIXME: Remove dummy argument.
1110  Args.insert(Args.end(), ArgBegin, ArgEnd);
1111
1112  // FIXME: Find a cleaner way to force the driver into restricted modes. We
1113  // also want to force it to use clang.
1114  Args.push_back("-fsyntax-only");
1115
1116  // FIXME: We shouldn't have to pass in the path info.
1117  driver::Driver TheDriver("clang", llvm::sys::getHostTriple(),
1118                           "a.out", false, false, *Diags);
1119
1120  // Don't check that inputs exist, they have been remapped.
1121  TheDriver.setCheckInputsExist(false);
1122
1123  llvm::OwningPtr<driver::Compilation> C(
1124    TheDriver.BuildCompilation(Args.size(), Args.data()));
1125
1126  // We expect to get back exactly one command job, if we didn't something
1127  // failed.
1128  const driver::JobList &Jobs = C->getJobs();
1129  if (Jobs.size() != 1 || !isa<driver::Command>(Jobs.begin())) {
1130    llvm::SmallString<256> Msg;
1131    llvm::raw_svector_ostream OS(Msg);
1132    C->PrintJob(OS, C->getJobs(), "; ", true);
1133    Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
1134    return 0;
1135  }
1136
1137  const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
1138  if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
1139    Diags->Report(diag::err_fe_expected_clang_command);
1140    return 0;
1141  }
1142
1143  const driver::ArgStringList &CCArgs = Cmd->getArguments();
1144  llvm::OwningPtr<CompilerInvocation> CI(new CompilerInvocation);
1145  CompilerInvocation::CreateFromArgs(*CI,
1146                                     const_cast<const char **>(CCArgs.data()),
1147                                     const_cast<const char **>(CCArgs.data()) +
1148                                     CCArgs.size(),
1149                                     *Diags);
1150
1151  // Override any files that need remapping
1152  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1153    CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1154                                              RemappedFiles[I].second);
1155
1156  // Override the resources path.
1157  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1158
1159  CI->getFrontendOpts().DisableFree = true;
1160  return LoadFromCompilerInvocation(CI.take(), Diags, OnlyLocalDecls,
1161                                    CaptureDiagnostics, PrecompilePreamble,
1162                                    CompleteTranslationUnit);
1163}
1164
1165bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1166  if (!Invocation.get())
1167    return true;
1168
1169  llvm::Timer *ReparsingTimer = 0;
1170  if (TimerGroup.get()) {
1171    ReparsingTimer = new llvm::Timer("Reparse", *TimerGroup);
1172    ReparsingTimer->startTimer();
1173    Timers.push_back(ReparsingTimer);
1174  }
1175
1176  // Remap files.
1177  Invocation->getPreprocessorOpts().clearRemappedFiles();
1178  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1179    Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1180                                                      RemappedFiles[I].second);
1181
1182  // If we have a preamble file lying around, or if we might try to
1183  // build a precompiled preamble, do so now.
1184  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1185  if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1186    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble();
1187
1188  // Clear out the diagnostics state.
1189  if (!OverrideMainBuffer)
1190    getDiagnostics().Reset();
1191
1192  // Parse the sources
1193  bool Result = Parse(OverrideMainBuffer);
1194  if (ReparsingTimer)
1195    ReparsingTimer->stopTimer();
1196  return Result;
1197}
1198
1199void ASTUnit::CodeComplete(llvm::StringRef File, unsigned Line, unsigned Column,
1200                           RemappedFile *RemappedFiles,
1201                           unsigned NumRemappedFiles,
1202                           bool IncludeMacros,
1203                           bool IncludeCodePatterns,
1204                           CodeCompleteConsumer &Consumer,
1205                           Diagnostic &Diag, LangOptions &LangOpts,
1206                           SourceManager &SourceMgr, FileManager &FileMgr,
1207                   llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics) {
1208  if (!Invocation.get())
1209    return;
1210
1211  llvm::Timer *CompletionTimer = 0;
1212  if (TimerGroup.get()) {
1213    llvm::SmallString<128> TimerName;
1214    llvm::raw_svector_ostream TimerNameOut(TimerName);
1215    TimerNameOut << "Code completion @ " << File << ":" << Line << ":"
1216                 << Column;
1217    CompletionTimer = new llvm::Timer(TimerNameOut.str(), *TimerGroup);
1218    CompletionTimer->startTimer();
1219    Timers.push_back(CompletionTimer);
1220  }
1221
1222  CompilerInvocation CCInvocation(*Invocation);
1223  FrontendOptions &FrontendOpts = CCInvocation.getFrontendOpts();
1224  PreprocessorOptions &PreprocessorOpts = CCInvocation.getPreprocessorOpts();
1225
1226  FrontendOpts.ShowMacrosInCodeCompletion = IncludeMacros;
1227  FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
1228  FrontendOpts.CodeCompletionAt.FileName = File;
1229  FrontendOpts.CodeCompletionAt.Line = Line;
1230  FrontendOpts.CodeCompletionAt.Column = Column;
1231
1232  // Turn on spell-checking when performing code completion. It leads
1233  // to better results.
1234  unsigned SpellChecking = CCInvocation.getLangOpts().SpellChecking;
1235  CCInvocation.getLangOpts().SpellChecking = 1;
1236
1237  // Set the language options appropriately.
1238  LangOpts = CCInvocation.getLangOpts();
1239
1240  CompilerInstance Clang;
1241  Clang.setInvocation(&CCInvocation);
1242  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1243
1244  // Set up diagnostics, capturing any diagnostics produced.
1245  Clang.setDiagnostics(&Diag);
1246  CaptureDroppedDiagnostics Capture(true,
1247                                    Clang.getDiagnostics(),
1248                                    StoredDiagnostics);
1249  Clang.setDiagnosticClient(Diag.getClient());
1250
1251  // Create the target instance.
1252  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1253                                               Clang.getTargetOpts()));
1254  if (!Clang.hasTarget()) {
1255    Clang.takeDiagnosticClient();
1256    Clang.takeInvocation();
1257  }
1258
1259  // Inform the target of the language options.
1260  //
1261  // FIXME: We shouldn't need to do this, the target should be immutable once
1262  // created. This complexity should be lifted elsewhere.
1263  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1264
1265  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1266         "Invocation must have exactly one source file!");
1267  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1268         "FIXME: AST inputs not yet supported here!");
1269  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1270         "IR inputs not support here!");
1271
1272
1273  // Use the source and file managers that we were given.
1274  Clang.setFileManager(&FileMgr);
1275  Clang.setSourceManager(&SourceMgr);
1276
1277  // Remap files.
1278  PreprocessorOpts.clearRemappedFiles();
1279  PreprocessorOpts.RetainRemappedFileBuffers = true;
1280  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1281    PreprocessorOpts.addRemappedFile(RemappedFiles[I].first,
1282                                     RemappedFiles[I].second);
1283
1284  // Use the code completion consumer we were given.
1285  Clang.setCodeCompletionConsumer(&Consumer);
1286
1287  // If we have a precompiled preamble, try to use it. We only allow
1288  // the use of the precompiled preamble if we're if the completion
1289  // point is within the main file, after the end of the precompiled
1290  // preamble.
1291  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1292  if (!PreambleFile.empty()) {
1293    using llvm::sys::FileStatus;
1294    llvm::sys::PathWithStatus CompleteFilePath(File);
1295    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
1296    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
1297      if (const FileStatus *MainStatus = MainPath.getFileStatus())
1298        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID())
1299          OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(false,
1300                                                                    Line);
1301  }
1302
1303  // If the main file has been overridden due to the use of a preamble,
1304  // make that override happen and introduce the preamble.
1305  if (OverrideMainBuffer) {
1306    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
1307    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1308    PreprocessorOpts.PrecompiledPreambleBytes.second
1309                                                    = PreambleEndsAtStartOfLine;
1310    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
1311    PreprocessorOpts.DisablePCHValidation = true;
1312
1313    // The stored diagnostics have the old source manager. Copy them
1314    // to our output set of stored diagnostics, updating the source
1315    // manager to the one we were given.
1316    for (unsigned I = 0, N = this->StoredDiagnostics.size(); I != N; ++I) {
1317      StoredDiagnostics.push_back(this->StoredDiagnostics[I]);
1318      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SourceMgr);
1319      StoredDiagnostics[I].setLocation(Loc);
1320    }
1321  }
1322
1323  llvm::OwningPtr<SyntaxOnlyAction> Act;
1324  Act.reset(new SyntaxOnlyAction);
1325  if (Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1326                           Clang.getFrontendOpts().Inputs[0].first)) {
1327    Act->Execute();
1328    Act->EndSourceFile();
1329  }
1330
1331  if (CompletionTimer)
1332    CompletionTimer->stopTimer();
1333
1334  // Steal back our resources.
1335  delete OverrideMainBuffer;
1336  Clang.takeFileManager();
1337  Clang.takeSourceManager();
1338  Clang.takeInvocation();
1339  Clang.takeDiagnosticClient();
1340  Clang.takeCodeCompletionConsumer();
1341  CCInvocation.getLangOpts().SpellChecking = SpellChecking;
1342}
1343