ASTUnit.cpp revision a5fb7c3b56c3698e19a7c1e97d41150de33cf6c9 
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/TypeOrdering.h"
20#include "clang/AST/StmtVisitor.h"
21#include "clang/Driver/Compilation.h"
22#include "clang/Driver/Driver.h"
23#include "clang/Driver/Job.h"
24#include "clang/Driver/Tool.h"
25#include "clang/Frontend/CompilerInstance.h"
26#include "clang/Frontend/FrontendActions.h"
27#include "clang/Frontend/FrontendDiagnostic.h"
28#include "clang/Frontend/FrontendOptions.h"
29#include "clang/Frontend/PCHReader.h"
30#include "clang/Lex/HeaderSearch.h"
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Basic/TargetOptions.h"
33#include "clang/Basic/TargetInfo.h"
34#include "clang/Basic/Diagnostic.h"
35#include "llvm/Support/MemoryBuffer.h"
36#include "llvm/System/Host.h"
37#include "llvm/System/Path.h"
38#include "llvm/Support/raw_ostream.h"
39#include "llvm/Support/Timer.h"
40#include <cstdlib>
41#include <cstdio>
42#include <sys/stat.h>
43using namespace clang;
44
45/// \brief After failing to build a precompiled preamble (due to
46/// errors in the source that occurs in the preamble), the number of
47/// reparses during which we'll skip even trying to precompile the
48/// preamble.
49const unsigned DefaultPreambleRebuildInterval = 5;
50
51ASTUnit::ASTUnit(bool _MainFileIsAST)
52  : CaptureDiagnostics(false), MainFileIsAST(_MainFileIsAST),
53    CompleteTranslationUnit(true), ConcurrencyCheckValue(CheckUnlocked),
54    PreambleRebuildCounter(0), SavedMainFileBuffer(0),
55    ShouldCacheCodeCompletionResults(false) {
56}
57
58ASTUnit::~ASTUnit() {
59  ConcurrencyCheckValue = CheckLocked;
60  CleanTemporaryFiles();
61  if (!PreambleFile.empty())
62    llvm::sys::Path(PreambleFile).eraseFromDisk();
63
64  // Free the buffers associated with remapped files. We are required to
65  // perform this operation here because we explicitly request that the
66  // compiler instance *not* free these buffers for each invocation of the
67  // parser.
68  if (Invocation.get()) {
69    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
70    for (PreprocessorOptions::remapped_file_buffer_iterator
71           FB = PPOpts.remapped_file_buffer_begin(),
72           FBEnd = PPOpts.remapped_file_buffer_end();
73         FB != FBEnd;
74         ++FB)
75      delete FB->second;
76  }
77
78  delete SavedMainFileBuffer;
79
80  ClearCachedCompletionResults();
81
82  for (unsigned I = 0, N = Timers.size(); I != N; ++I)
83    delete Timers[I];
84}
85
86void ASTUnit::CleanTemporaryFiles() {
87  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
88    TemporaryFiles[I].eraseFromDisk();
89  TemporaryFiles.clear();
90}
91
92/// \brief Determine the set of code-completion contexts in which this
93/// declaration should be shown.
94static unsigned getDeclShowContexts(NamedDecl *ND,
95                                    const LangOptions &LangOpts,
96                                    bool &IsNestedNameSpecifier) {
97  IsNestedNameSpecifier = false;
98
99  if (isa<UsingShadowDecl>(ND))
100    ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
101  if (!ND)
102    return 0;
103
104  unsigned Contexts = 0;
105  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
106      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
107    // Types can appear in these contexts.
108    if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
109      Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
110                | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
111                | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
112                | (1 << (CodeCompletionContext::CCC_Statement - 1))
113                | (1 << (CodeCompletionContext::CCC_Type - 1));
114
115    // In C++, types can appear in expressions contexts (for functional casts).
116    if (LangOpts.CPlusPlus)
117      Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
118
119    // In Objective-C, message sends can send interfaces. In Objective-C++,
120    // all types are available due to functional casts.
121    if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
122      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
123
124    // Deal with tag names.
125    if (isa<EnumDecl>(ND)) {
126      Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
127
128      // Part of the nested-name-specifier in C++0x.
129      if (LangOpts.CPlusPlus0x)
130        IsNestedNameSpecifier = true;
131    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
132      if (Record->isUnion())
133        Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
134      else
135        Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
136
137      if (LangOpts.CPlusPlus)
138        IsNestedNameSpecifier = true;
139    } else if (isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND))
140      IsNestedNameSpecifier = true;
141  } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
142    // Values can appear in these contexts.
143    Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
144             | (1 << (CodeCompletionContext::CCC_Expression - 1))
145             | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
146  } else if (isa<ObjCProtocolDecl>(ND)) {
147    Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
148  } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
149    Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
150
151    // Part of the nested-name-specifier.
152    IsNestedNameSpecifier = true;
153  }
154
155  return Contexts;
156}
157
158void ASTUnit::CacheCodeCompletionResults() {
159  if (!TheSema)
160    return;
161
162  llvm::Timer *CachingTimer = 0;
163  if (TimerGroup.get()) {
164    CachingTimer = new llvm::Timer("Cache global code completions",
165                                   *TimerGroup);
166    CachingTimer->startTimer();
167    Timers.push_back(CachingTimer);
168  }
169
170  // Clear out the previous results.
171  ClearCachedCompletionResults();
172
173  // Gather the set of global code completions.
174  typedef CodeCompleteConsumer::Result Result;
175  llvm::SmallVector<Result, 8> Results;
176  TheSema->GatherGlobalCodeCompletions(Results);
177
178  // Translate global code completions into cached completions.
179  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
180
181  for (unsigned I = 0, N = Results.size(); I != N; ++I) {
182    switch (Results[I].Kind) {
183    case Result::RK_Declaration: {
184      bool IsNestedNameSpecifier = false;
185      CachedCodeCompletionResult CachedResult;
186      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
187      CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
188                                                        Ctx->getLangOptions(),
189                                                        IsNestedNameSpecifier);
190      CachedResult.Priority = Results[I].Priority;
191      CachedResult.Kind = Results[I].CursorKind;
192
193      // Keep track of the type of this completion in an ASTContext-agnostic
194      // way.
195      QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
196      if (UsageType.isNull()) {
197        CachedResult.TypeClass = STC_Void;
198        CachedResult.Type = 0;
199      } else {
200        CanQualType CanUsageType
201          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
202        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
203
204        // Determine whether we have already seen this type. If so, we save
205        // ourselves the work of formatting the type string by using the
206        // temporary, CanQualType-based hash table to find the associated value.
207        unsigned &TypeValue = CompletionTypes[CanUsageType];
208        if (TypeValue == 0) {
209          TypeValue = CompletionTypes.size();
210          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
211            = TypeValue;
212        }
213
214        CachedResult.Type = TypeValue;
215      }
216
217      CachedCompletionResults.push_back(CachedResult);
218
219      /// Handle nested-name-specifiers in C++.
220      if (TheSema->Context.getLangOptions().CPlusPlus &&
221          IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
222        // The contexts in which a nested-name-specifier can appear in C++.
223        unsigned NNSContexts
224          = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
225          | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
226          | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
227          | (1 << (CodeCompletionContext::CCC_Statement - 1))
228          | (1 << (CodeCompletionContext::CCC_Expression - 1))
229          | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
230          | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
231          | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
232          | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
233          | (1 << (CodeCompletionContext::CCC_Type - 1));
234
235        if (isa<NamespaceDecl>(Results[I].Declaration) ||
236            isa<NamespaceAliasDecl>(Results[I].Declaration))
237          NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
238
239        if (unsigned RemainingContexts
240                                = NNSContexts & ~CachedResult.ShowInContexts) {
241          // If there any contexts where this completion can be a
242          // nested-name-specifier but isn't already an option, create a
243          // nested-name-specifier completion.
244          Results[I].StartsNestedNameSpecifier = true;
245          CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
246          CachedResult.ShowInContexts = RemainingContexts;
247          CachedResult.Priority = CCP_NestedNameSpecifier;
248          CachedResult.TypeClass = STC_Void;
249          CachedResult.Type = 0;
250          CachedCompletionResults.push_back(CachedResult);
251        }
252      }
253      break;
254    }
255
256    case Result::RK_Keyword:
257    case Result::RK_Pattern:
258      // Ignore keywords and patterns; we don't care, since they are so
259      // easily regenerated.
260      break;
261
262    case Result::RK_Macro: {
263      CachedCodeCompletionResult CachedResult;
264      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
265      CachedResult.ShowInContexts
266        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
267        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
268        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
269        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
270        | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
271        | (1 << (CodeCompletionContext::CCC_Statement - 1))
272        | (1 << (CodeCompletionContext::CCC_Expression - 1))
273        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
274      CachedResult.Priority = Results[I].Priority;
275      CachedResult.Kind = Results[I].CursorKind;
276      CachedResult.TypeClass = STC_Void;
277      CachedResult.Type = 0;
278      CachedCompletionResults.push_back(CachedResult);
279      break;
280    }
281    }
282    Results[I].Destroy();
283  }
284
285  if (CachingTimer)
286    CachingTimer->stopTimer();
287}
288
289void ASTUnit::ClearCachedCompletionResults() {
290  for (unsigned I = 0, N = CachedCompletionResults.size(); I != N; ++I)
291    delete CachedCompletionResults[I].Completion;
292  CachedCompletionResults.clear();
293  CachedCompletionTypes.clear();
294}
295
296namespace {
297
298/// \brief Gathers information from PCHReader that will be used to initialize
299/// a Preprocessor.
300class PCHInfoCollector : public PCHReaderListener {
301  LangOptions &LangOpt;
302  HeaderSearch &HSI;
303  std::string &TargetTriple;
304  std::string &Predefines;
305  unsigned &Counter;
306
307  unsigned NumHeaderInfos;
308
309public:
310  PCHInfoCollector(LangOptions &LangOpt, HeaderSearch &HSI,
311                   std::string &TargetTriple, std::string &Predefines,
312                   unsigned &Counter)
313    : LangOpt(LangOpt), HSI(HSI), TargetTriple(TargetTriple),
314      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0) {}
315
316  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
317    LangOpt = LangOpts;
318    return false;
319  }
320
321  virtual bool ReadTargetTriple(llvm::StringRef Triple) {
322    TargetTriple = Triple;
323    return false;
324  }
325
326  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
327                                    llvm::StringRef OriginalFileName,
328                                    std::string &SuggestedPredefines) {
329    Predefines = Buffers[0].Data;
330    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
331      Predefines += Buffers[I].Data;
332    }
333    return false;
334  }
335
336  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
337    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
338  }
339
340  virtual void ReadCounter(unsigned Value) {
341    Counter = Value;
342  }
343};
344
345class StoredDiagnosticClient : public DiagnosticClient {
346  llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags;
347
348public:
349  explicit StoredDiagnosticClient(
350                          llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
351    : StoredDiags(StoredDiags) { }
352
353  virtual void HandleDiagnostic(Diagnostic::Level Level,
354                                const DiagnosticInfo &Info);
355};
356
357/// \brief RAII object that optionally captures diagnostics, if
358/// there is no diagnostic client to capture them already.
359class CaptureDroppedDiagnostics {
360  Diagnostic &Diags;
361  StoredDiagnosticClient Client;
362  DiagnosticClient *PreviousClient;
363
364public:
365  CaptureDroppedDiagnostics(bool RequestCapture, Diagnostic &Diags,
366                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
367    : Diags(Diags), Client(StoredDiags), PreviousClient(Diags.getClient())
368  {
369    if (RequestCapture || Diags.getClient() == 0)
370      Diags.setClient(&Client);
371  }
372
373  ~CaptureDroppedDiagnostics() {
374    Diags.setClient(PreviousClient);
375  }
376};
377
378} // anonymous namespace
379
380void StoredDiagnosticClient::HandleDiagnostic(Diagnostic::Level Level,
381                                              const DiagnosticInfo &Info) {
382  StoredDiags.push_back(StoredDiagnostic(Level, Info));
383}
384
385const std::string &ASTUnit::getOriginalSourceFileName() {
386  return OriginalSourceFile;
387}
388
389const std::string &ASTUnit::getPCHFileName() {
390  assert(isMainFileAST() && "Not an ASTUnit from a PCH file!");
391  return static_cast<PCHReader *>(Ctx->getExternalSource())->getFileName();
392}
393
394ASTUnit *ASTUnit::LoadFromPCHFile(const std::string &Filename,
395                                  llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
396                                  bool OnlyLocalDecls,
397                                  RemappedFile *RemappedFiles,
398                                  unsigned NumRemappedFiles,
399                                  bool CaptureDiagnostics) {
400  llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
401
402  if (!Diags.getPtr()) {
403    // No diagnostics engine was provided, so create our own diagnostics object
404    // with the default options.
405    DiagnosticOptions DiagOpts;
406    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
407  }
408
409  AST->CaptureDiagnostics = CaptureDiagnostics;
410  AST->OnlyLocalDecls = OnlyLocalDecls;
411  AST->Diagnostics = Diags;
412  AST->FileMgr.reset(new FileManager);
413  AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics()));
414  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
415
416  // If requested, capture diagnostics in the ASTUnit.
417  CaptureDroppedDiagnostics Capture(CaptureDiagnostics, AST->getDiagnostics(),
418                                    AST->StoredDiagnostics);
419
420  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
421    // Create the file entry for the file that we're mapping from.
422    const FileEntry *FromFile
423      = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
424                                    RemappedFiles[I].second->getBufferSize(),
425                                             0);
426    if (!FromFile) {
427      AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
428        << RemappedFiles[I].first;
429      delete RemappedFiles[I].second;
430      continue;
431    }
432
433    // Override the contents of the "from" file with the contents of
434    // the "to" file.
435    AST->getSourceManager().overrideFileContents(FromFile,
436                                                 RemappedFiles[I].second);
437  }
438
439  // Gather Info for preprocessor construction later on.
440
441  LangOptions LangInfo;
442  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
443  std::string TargetTriple;
444  std::string Predefines;
445  unsigned Counter;
446
447  llvm::OwningPtr<PCHReader> Reader;
448
449  Reader.reset(new PCHReader(AST->getSourceManager(), AST->getFileManager(),
450                             AST->getDiagnostics()));
451  Reader->setListener(new PCHInfoCollector(LangInfo, HeaderInfo, TargetTriple,
452                                           Predefines, Counter));
453
454  switch (Reader->ReadPCH(Filename)) {
455  case PCHReader::Success:
456    break;
457
458  case PCHReader::Failure:
459  case PCHReader::IgnorePCH:
460    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
461    return NULL;
462  }
463
464  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
465
466  // PCH loaded successfully. Now create the preprocessor.
467
468  // Get information about the target being compiled for.
469  //
470  // FIXME: This is broken, we should store the TargetOptions in the PCH.
471  TargetOptions TargetOpts;
472  TargetOpts.ABI = "";
473  TargetOpts.CXXABI = "itanium";
474  TargetOpts.CPU = "";
475  TargetOpts.Features.clear();
476  TargetOpts.Triple = TargetTriple;
477  AST->Target.reset(TargetInfo::CreateTargetInfo(AST->getDiagnostics(),
478                                                 TargetOpts));
479  AST->PP.reset(new Preprocessor(AST->getDiagnostics(), LangInfo,
480                                 *AST->Target.get(),
481                                 AST->getSourceManager(), HeaderInfo));
482  Preprocessor &PP = *AST->PP.get();
483
484  PP.setPredefines(Reader->getSuggestedPredefines());
485  PP.setCounterValue(Counter);
486  Reader->setPreprocessor(PP);
487
488  // Create and initialize the ASTContext.
489
490  AST->Ctx.reset(new ASTContext(LangInfo,
491                                AST->getSourceManager(),
492                                *AST->Target.get(),
493                                PP.getIdentifierTable(),
494                                PP.getSelectorTable(),
495                                PP.getBuiltinInfo(),
496                                /* size_reserve = */0));
497  ASTContext &Context = *AST->Ctx.get();
498
499  Reader->InitializeContext(Context);
500
501  // Attach the PCH reader to the AST context as an external AST
502  // source, so that declarations will be deserialized from the
503  // PCH file as needed.
504  PCHReader *ReaderPtr = Reader.get();
505  llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
506  Context.setExternalSource(Source);
507
508  // Create an AST consumer, even though it isn't used.
509  AST->Consumer.reset(new ASTConsumer);
510
511  // Create a semantic analysis object and tell the PCH reader about it.
512  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
513  AST->TheSema->Initialize();
514  ReaderPtr->InitializeSema(*AST->TheSema);
515
516  return AST.take();
517}
518
519namespace {
520
521class TopLevelDeclTrackerConsumer : public ASTConsumer {
522  ASTUnit &Unit;
523
524public:
525  TopLevelDeclTrackerConsumer(ASTUnit &_Unit) : Unit(_Unit) {}
526
527  void HandleTopLevelDecl(DeclGroupRef D) {
528    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
529      Decl *D = *it;
530      // FIXME: Currently ObjC method declarations are incorrectly being
531      // reported as top-level declarations, even though their DeclContext
532      // is the containing ObjC @interface/@implementation.  This is a
533      // fundamental problem in the parser right now.
534      if (isa<ObjCMethodDecl>(D))
535        continue;
536      Unit.addTopLevelDecl(D);
537    }
538  }
539
540  // We're not interested in "interesting" decls.
541  void HandleInterestingDecl(DeclGroupRef) {}
542};
543
544class TopLevelDeclTrackerAction : public ASTFrontendAction {
545public:
546  ASTUnit &Unit;
547
548  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
549                                         llvm::StringRef InFile) {
550    return new TopLevelDeclTrackerConsumer(Unit);
551  }
552
553public:
554  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
555
556  virtual bool hasCodeCompletionSupport() const { return false; }
557  virtual bool usesCompleteTranslationUnit()  {
558    return Unit.isCompleteTranslationUnit();
559  }
560};
561
562class PrecompilePreambleConsumer : public PCHGenerator {
563  ASTUnit &Unit;
564  std::vector<Decl *> TopLevelDecls;
565
566public:
567  PrecompilePreambleConsumer(ASTUnit &Unit,
568                             const Preprocessor &PP, bool Chaining,
569                             const char *isysroot, llvm::raw_ostream *Out)
570    : PCHGenerator(PP, Chaining, isysroot, Out), Unit(Unit) { }
571
572  virtual void HandleTopLevelDecl(DeclGroupRef D) {
573    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
574      Decl *D = *it;
575      // FIXME: Currently ObjC method declarations are incorrectly being
576      // reported as top-level declarations, even though their DeclContext
577      // is the containing ObjC @interface/@implementation.  This is a
578      // fundamental problem in the parser right now.
579      if (isa<ObjCMethodDecl>(D))
580        continue;
581      TopLevelDecls.push_back(D);
582    }
583  }
584
585  virtual void HandleTranslationUnit(ASTContext &Ctx) {
586    PCHGenerator::HandleTranslationUnit(Ctx);
587    if (!Unit.getDiagnostics().hasErrorOccurred()) {
588      // Translate the top-level declarations we captured during
589      // parsing into declaration IDs in the precompiled
590      // preamble. This will allow us to deserialize those top-level
591      // declarations when requested.
592      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
593        Unit.addTopLevelDeclFromPreamble(
594                                      getWriter().getDeclID(TopLevelDecls[I]));
595    }
596  }
597};
598
599class PrecompilePreambleAction : public ASTFrontendAction {
600  ASTUnit &Unit;
601
602public:
603  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
604
605  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
606                                         llvm::StringRef InFile) {
607    std::string Sysroot;
608    llvm::raw_ostream *OS = 0;
609    bool Chaining;
610    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
611                                                       OS, Chaining))
612      return 0;
613
614    const char *isysroot = CI.getFrontendOpts().RelocatablePCH ?
615                             Sysroot.c_str() : 0;
616    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Chaining,
617                                          isysroot, OS);
618  }
619
620  virtual bool hasCodeCompletionSupport() const { return false; }
621  virtual bool hasASTFileSupport() const { return false; }
622  virtual bool usesCompleteTranslationUnit() { return false; }
623};
624
625}
626
627/// Parse the source file into a translation unit using the given compiler
628/// invocation, replacing the current translation unit.
629///
630/// \returns True if a failure occurred that causes the ASTUnit not to
631/// contain any translation-unit information, false otherwise.
632bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
633  delete SavedMainFileBuffer;
634  SavedMainFileBuffer = 0;
635
636  if (!Invocation.get())
637    return true;
638
639  // Create the compiler instance to use for building the AST.
640  CompilerInstance Clang;
641  Clang.setInvocation(Invocation.take());
642  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
643
644  // Set up diagnostics, capturing any diagnostics that would
645  // otherwise be dropped.
646  Clang.setDiagnostics(&getDiagnostics());
647  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
648                                    getDiagnostics(),
649                                    StoredDiagnostics);
650  Clang.setDiagnosticClient(getDiagnostics().getClient());
651
652  // Create the target instance.
653  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
654                                               Clang.getTargetOpts()));
655  if (!Clang.hasTarget()) {
656    Clang.takeDiagnosticClient();
657    return true;
658  }
659
660  // Inform the target of the language options.
661  //
662  // FIXME: We shouldn't need to do this, the target should be immutable once
663  // created. This complexity should be lifted elsewhere.
664  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
665
666  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
667         "Invocation must have exactly one source file!");
668  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
669         "FIXME: AST inputs not yet supported here!");
670  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
671         "IR inputs not support here!");
672
673  // Configure the various subsystems.
674  // FIXME: Should we retain the previous file manager?
675  FileMgr.reset(new FileManager);
676  SourceMgr.reset(new SourceManager(getDiagnostics()));
677  TheSema.reset();
678  Ctx.reset();
679  PP.reset();
680
681  // Clear out old caches and data.
682  TopLevelDecls.clear();
683  CleanTemporaryFiles();
684  PreprocessedEntitiesByFile.clear();
685
686  if (!OverrideMainBuffer)
687    StoredDiagnostics.clear();
688
689  // Create a file manager object to provide access to and cache the filesystem.
690  Clang.setFileManager(&getFileManager());
691
692  // Create the source manager.
693  Clang.setSourceManager(&getSourceManager());
694
695  // If the main file has been overridden due to the use of a preamble,
696  // make that override happen and introduce the preamble.
697  PreprocessorOptions &PreprocessorOpts = Clang.getPreprocessorOpts();
698  std::string PriorImplicitPCHInclude;
699  if (OverrideMainBuffer) {
700    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
701    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
702    PreprocessorOpts.PrecompiledPreambleBytes.second
703                                                    = PreambleEndsAtStartOfLine;
704    PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
705    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
706    PreprocessorOpts.DisablePCHValidation = true;
707
708    // Keep track of the override buffer;
709    SavedMainFileBuffer = OverrideMainBuffer;
710
711    // The stored diagnostic has the old source manager in it; update
712    // the locations to refer into the new source manager. Since we've
713    // been careful to make sure that the source manager's state
714    // before and after are identical, so that we can reuse the source
715    // location itself.
716    for (unsigned I = 0, N = StoredDiagnostics.size(); I != N; ++I) {
717      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
718                        getSourceManager());
719      StoredDiagnostics[I].setLocation(Loc);
720    }
721  }
722
723  llvm::OwningPtr<TopLevelDeclTrackerAction> Act;
724  Act.reset(new TopLevelDeclTrackerAction(*this));
725  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
726                            Clang.getFrontendOpts().Inputs[0].first))
727    goto error;
728
729  Act->Execute();
730
731  // Steal the created target, context, and preprocessor, and take back the
732  // source and file managers.
733  TheSema.reset(Clang.takeSema());
734  Consumer.reset(Clang.takeASTConsumer());
735  Ctx.reset(Clang.takeASTContext());
736  PP.reset(Clang.takePreprocessor());
737  Clang.takeSourceManager();
738  Clang.takeFileManager();
739  Target.reset(Clang.takeTarget());
740
741  Act->EndSourceFile();
742
743  // Remove the overridden buffer we used for the preamble.
744  if (OverrideMainBuffer) {
745    PreprocessorOpts.eraseRemappedFile(
746                               PreprocessorOpts.remapped_file_buffer_end() - 1);
747    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
748  }
749
750  Clang.takeDiagnosticClient();
751
752  Invocation.reset(Clang.takeInvocation());
753
754  // If we were asked to cache code-completion results and don't have any
755  // results yet, do so now.
756  if (ShouldCacheCodeCompletionResults && CachedCompletionResults.empty())
757    CacheCodeCompletionResults();
758
759  return false;
760
761error:
762  // Remove the overridden buffer we used for the preamble.
763  if (OverrideMainBuffer) {
764    PreprocessorOpts.eraseRemappedFile(
765                               PreprocessorOpts.remapped_file_buffer_end() - 1);
766    PreprocessorOpts.DisablePCHValidation = true;
767    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
768  }
769
770  Clang.takeSourceManager();
771  Clang.takeFileManager();
772  Clang.takeDiagnosticClient();
773  Invocation.reset(Clang.takeInvocation());
774  return true;
775}
776
777/// \brief Simple function to retrieve a path for a preamble precompiled header.
778static std::string GetPreamblePCHPath() {
779  // FIXME: This is lame; sys::Path should provide this function (in particular,
780  // it should know how to find the temporary files dir).
781  // FIXME: This is really lame. I copied this code from the Driver!
782  std::string Error;
783  const char *TmpDir = ::getenv("TMPDIR");
784  if (!TmpDir)
785    TmpDir = ::getenv("TEMP");
786  if (!TmpDir)
787    TmpDir = ::getenv("TMP");
788  if (!TmpDir)
789    TmpDir = "/tmp";
790  llvm::sys::Path P(TmpDir);
791  P.appendComponent("preamble");
792  P.appendSuffix("pch");
793  if (P.createTemporaryFileOnDisk())
794    return std::string();
795
796  return P.str();
797}
798
799/// \brief Compute the preamble for the main file, providing the source buffer
800/// that corresponds to the main file along with a pair (bytes, start-of-line)
801/// that describes the preamble.
802std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
803ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
804                         unsigned MaxLines, bool &CreatedBuffer) {
805  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
806  PreprocessorOptions &PreprocessorOpts
807    = Invocation.getPreprocessorOpts();
808  CreatedBuffer = false;
809
810  // Try to determine if the main file has been remapped, either from the
811  // command line (to another file) or directly through the compiler invocation
812  // (to a memory buffer).
813  llvm::MemoryBuffer *Buffer = 0;
814  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
815  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
816    // Check whether there is a file-file remapping of the main file
817    for (PreprocessorOptions::remapped_file_iterator
818          M = PreprocessorOpts.remapped_file_begin(),
819          E = PreprocessorOpts.remapped_file_end();
820         M != E;
821         ++M) {
822      llvm::sys::PathWithStatus MPath(M->first);
823      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
824        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
825          // We found a remapping. Try to load the resulting, remapped source.
826          if (CreatedBuffer) {
827            delete Buffer;
828            CreatedBuffer = false;
829          }
830
831          Buffer = llvm::MemoryBuffer::getFile(M->second);
832          if (!Buffer)
833            return std::make_pair((llvm::MemoryBuffer*)0,
834                                  std::make_pair(0, true));
835          CreatedBuffer = true;
836
837          // Remove this remapping. We've captured the buffer already.
838          M = PreprocessorOpts.eraseRemappedFile(M);
839          E = PreprocessorOpts.remapped_file_end();
840        }
841      }
842    }
843
844    // Check whether there is a file-buffer remapping. It supercedes the
845    // file-file remapping.
846    for (PreprocessorOptions::remapped_file_buffer_iterator
847           M = PreprocessorOpts.remapped_file_buffer_begin(),
848           E = PreprocessorOpts.remapped_file_buffer_end();
849         M != E;
850         ++M) {
851      llvm::sys::PathWithStatus MPath(M->first);
852      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
853        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
854          // We found a remapping.
855          if (CreatedBuffer) {
856            delete Buffer;
857            CreatedBuffer = false;
858          }
859
860          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
861
862          // Remove this remapping. We've captured the buffer already.
863          M = PreprocessorOpts.eraseRemappedFile(M);
864          E = PreprocessorOpts.remapped_file_buffer_end();
865        }
866      }
867    }
868  }
869
870  // If the main source file was not remapped, load it now.
871  if (!Buffer) {
872    Buffer = llvm::MemoryBuffer::getFile(FrontendOpts.Inputs[0].second);
873    if (!Buffer)
874      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
875
876    CreatedBuffer = true;
877  }
878
879  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer, MaxLines));
880}
881
882static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
883                                                      bool DeleteOld,
884                                                      unsigned NewSize,
885                                                      llvm::StringRef NewName) {
886  llvm::MemoryBuffer *Result
887    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
888  memcpy(const_cast<char*>(Result->getBufferStart()),
889         Old->getBufferStart(), Old->getBufferSize());
890  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
891         ' ', NewSize - Old->getBufferSize() - 1);
892  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
893
894  if (DeleteOld)
895    delete Old;
896
897  return Result;
898}
899
900/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
901/// the source file.
902///
903/// This routine will compute the preamble of the main source file. If a
904/// non-trivial preamble is found, it will precompile that preamble into a
905/// precompiled header so that the precompiled preamble can be used to reduce
906/// reparsing time. If a precompiled preamble has already been constructed,
907/// this routine will determine if it is still valid and, if so, avoid
908/// rebuilding the precompiled preamble.
909///
910/// \param AllowRebuild When true (the default), this routine is
911/// allowed to rebuild the precompiled preamble if it is found to be
912/// out-of-date.
913///
914/// \param MaxLines When non-zero, the maximum number of lines that
915/// can occur within the preamble.
916///
917/// \returns If the precompiled preamble can be used, returns a newly-allocated
918/// buffer that should be used in place of the main file when doing so.
919/// Otherwise, returns a NULL pointer.
920llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
921                                                           bool AllowRebuild,
922                                                           unsigned MaxLines) {
923  CompilerInvocation PreambleInvocation(*Invocation);
924  FrontendOptions &FrontendOpts = PreambleInvocation.getFrontendOpts();
925  PreprocessorOptions &PreprocessorOpts
926    = PreambleInvocation.getPreprocessorOpts();
927
928  bool CreatedPreambleBuffer = false;
929  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
930    = ComputePreamble(PreambleInvocation, MaxLines, CreatedPreambleBuffer);
931
932  if (!NewPreamble.second.first) {
933    // We couldn't find a preamble in the main source. Clear out the current
934    // preamble, if we have one. It's obviously no good any more.
935    Preamble.clear();
936    if (!PreambleFile.empty()) {
937      llvm::sys::Path(PreambleFile).eraseFromDisk();
938      PreambleFile.clear();
939    }
940    if (CreatedPreambleBuffer)
941      delete NewPreamble.first;
942
943    // The next time we actually see a preamble, precompile it.
944    PreambleRebuildCounter = 1;
945    return 0;
946  }
947
948  if (!Preamble.empty()) {
949    // We've previously computed a preamble. Check whether we have the same
950    // preamble now that we did before, and that there's enough space in
951    // the main-file buffer within the precompiled preamble to fit the
952    // new main file.
953    if (Preamble.size() == NewPreamble.second.first &&
954        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
955        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
956        memcmp(&Preamble[0], NewPreamble.first->getBufferStart(),
957               NewPreamble.second.first) == 0) {
958      // The preamble has not changed. We may be able to re-use the precompiled
959      // preamble.
960
961      // Check that none of the files used by the preamble have changed.
962      bool AnyFileChanged = false;
963
964      // First, make a record of those files that have been overridden via
965      // remapping or unsaved_files.
966      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
967      for (PreprocessorOptions::remapped_file_iterator
968                R = PreprocessorOpts.remapped_file_begin(),
969             REnd = PreprocessorOpts.remapped_file_end();
970           !AnyFileChanged && R != REnd;
971           ++R) {
972        struct stat StatBuf;
973        if (stat(R->second.c_str(), &StatBuf)) {
974          // If we can't stat the file we're remapping to, assume that something
975          // horrible happened.
976          AnyFileChanged = true;
977          break;
978        }
979
980        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
981                                                   StatBuf.st_mtime);
982      }
983      for (PreprocessorOptions::remapped_file_buffer_iterator
984                R = PreprocessorOpts.remapped_file_buffer_begin(),
985             REnd = PreprocessorOpts.remapped_file_buffer_end();
986           !AnyFileChanged && R != REnd;
987           ++R) {
988        // FIXME: Should we actually compare the contents of file->buffer
989        // remappings?
990        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
991                                                   0);
992      }
993
994      // Check whether anything has changed.
995      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
996             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
997           !AnyFileChanged && F != FEnd;
998           ++F) {
999        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1000          = OverriddenFiles.find(F->first());
1001        if (Overridden != OverriddenFiles.end()) {
1002          // This file was remapped; check whether the newly-mapped file
1003          // matches up with the previous mapping.
1004          if (Overridden->second != F->second)
1005            AnyFileChanged = true;
1006          continue;
1007        }
1008
1009        // The file was not remapped; check whether it has changed on disk.
1010        struct stat StatBuf;
1011        if (stat(F->first(), &StatBuf)) {
1012          // If we can't stat the file, assume that something horrible happened.
1013          AnyFileChanged = true;
1014        } else if (StatBuf.st_size != F->second.first ||
1015                   StatBuf.st_mtime != F->second.second)
1016          AnyFileChanged = true;
1017      }
1018
1019      if (!AnyFileChanged) {
1020        // Okay! We can re-use the precompiled preamble.
1021
1022        // Set the state of the diagnostic object to mimic its state
1023        // after parsing the preamble.
1024        getDiagnostics().Reset();
1025        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1026        if (StoredDiagnostics.size() > NumStoredDiagnosticsInPreamble)
1027          StoredDiagnostics.erase(
1028            StoredDiagnostics.begin() + NumStoredDiagnosticsInPreamble,
1029                                  StoredDiagnostics.end());
1030
1031        // Create a version of the main file buffer that is padded to
1032        // buffer size we reserved when creating the preamble.
1033        return CreatePaddedMainFileBuffer(NewPreamble.first,
1034                                          CreatedPreambleBuffer,
1035                                          PreambleReservedSize,
1036                                          FrontendOpts.Inputs[0].second);
1037      }
1038    }
1039
1040    // If we aren't allowed to rebuild the precompiled preamble, just
1041    // return now.
1042    if (!AllowRebuild)
1043      return 0;
1044
1045    // We can't reuse the previously-computed preamble. Build a new one.
1046    Preamble.clear();
1047    llvm::sys::Path(PreambleFile).eraseFromDisk();
1048    PreambleRebuildCounter = 1;
1049  } else if (!AllowRebuild) {
1050    // We aren't allowed to rebuild the precompiled preamble; just
1051    // return now.
1052    return 0;
1053  }
1054
1055  // If the preamble rebuild counter > 1, it's because we previously
1056  // failed to build a preamble and we're not yet ready to try
1057  // again. Decrement the counter and return a failure.
1058  if (PreambleRebuildCounter > 1) {
1059    --PreambleRebuildCounter;
1060    return 0;
1061  }
1062
1063  // We did not previously compute a preamble, or it can't be reused anyway.
1064  llvm::Timer *PreambleTimer = 0;
1065  if (TimerGroup.get()) {
1066    PreambleTimer = new llvm::Timer("Precompiling preamble", *TimerGroup);
1067    PreambleTimer->startTimer();
1068    Timers.push_back(PreambleTimer);
1069  }
1070
1071  // Create a new buffer that stores the preamble. The buffer also contains
1072  // extra space for the original contents of the file (which will be present
1073  // when we actually parse the file) along with more room in case the file
1074  // grows.
1075  PreambleReservedSize = NewPreamble.first->getBufferSize();
1076  if (PreambleReservedSize < 4096)
1077    PreambleReservedSize = 8191;
1078  else
1079    PreambleReservedSize *= 2;
1080
1081  // Save the preamble text for later; we'll need to compare against it for
1082  // subsequent reparses.
1083  Preamble.assign(NewPreamble.first->getBufferStart(),
1084                  NewPreamble.first->getBufferStart()
1085                                                  + NewPreamble.second.first);
1086  PreambleEndsAtStartOfLine = NewPreamble.second.second;
1087
1088  llvm::MemoryBuffer *PreambleBuffer
1089    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1090                                                FrontendOpts.Inputs[0].second);
1091  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1092         NewPreamble.first->getBufferStart(), Preamble.size());
1093  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1094         ' ', PreambleReservedSize - Preamble.size() - 1);
1095  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1096
1097  // Remap the main source file to the preamble buffer.
1098  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1099  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1100
1101  // Tell the compiler invocation to generate a temporary precompiled header.
1102  FrontendOpts.ProgramAction = frontend::GeneratePCH;
1103  // FIXME: Set ChainedPCH unconditionally, once it is ready.
1104  if (::getenv("LIBCLANG_CHAINING"))
1105    FrontendOpts.ChainedPCH = true;
1106  // FIXME: Generate the precompiled header into memory?
1107  FrontendOpts.OutputFile = GetPreamblePCHPath();
1108
1109  // Create the compiler instance to use for building the precompiled preamble.
1110  CompilerInstance Clang;
1111  Clang.setInvocation(&PreambleInvocation);
1112  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1113
1114  // Set up diagnostics, capturing all of the diagnostics produced.
1115  Clang.setDiagnostics(&getDiagnostics());
1116  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
1117                                    getDiagnostics(),
1118                                    StoredDiagnostics);
1119  Clang.setDiagnosticClient(getDiagnostics().getClient());
1120
1121  // Create the target instance.
1122  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1123                                               Clang.getTargetOpts()));
1124  if (!Clang.hasTarget()) {
1125    Clang.takeDiagnosticClient();
1126    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1127    Preamble.clear();
1128    if (CreatedPreambleBuffer)
1129      delete NewPreamble.first;
1130    if (PreambleTimer)
1131      PreambleTimer->stopTimer();
1132    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1133    return 0;
1134  }
1135
1136  // Inform the target of the language options.
1137  //
1138  // FIXME: We shouldn't need to do this, the target should be immutable once
1139  // created. This complexity should be lifted elsewhere.
1140  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1141
1142  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1143         "Invocation must have exactly one source file!");
1144  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1145         "FIXME: AST inputs not yet supported here!");
1146  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1147         "IR inputs not support here!");
1148
1149  // Clear out old caches and data.
1150  StoredDiagnostics.clear();
1151  TopLevelDecls.clear();
1152  TopLevelDeclsInPreamble.clear();
1153
1154  // Create a file manager object to provide access to and cache the filesystem.
1155  Clang.setFileManager(new FileManager);
1156
1157  // Create the source manager.
1158  Clang.setSourceManager(new SourceManager(getDiagnostics()));
1159
1160  llvm::OwningPtr<PrecompilePreambleAction> Act;
1161  Act.reset(new PrecompilePreambleAction(*this));
1162  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1163                            Clang.getFrontendOpts().Inputs[0].first)) {
1164    Clang.takeDiagnosticClient();
1165    Clang.takeInvocation();
1166    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1167    Preamble.clear();
1168    if (CreatedPreambleBuffer)
1169      delete NewPreamble.first;
1170    if (PreambleTimer)
1171      PreambleTimer->stopTimer();
1172    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1173
1174    return 0;
1175  }
1176
1177  Act->Execute();
1178  Act->EndSourceFile();
1179  Clang.takeDiagnosticClient();
1180  Clang.takeInvocation();
1181
1182  if (Diagnostics->hasErrorOccurred()) {
1183    // There were errors parsing the preamble, so no precompiled header was
1184    // generated. Forget that we even tried.
1185    // FIXME: Should we leave a note for ourselves to try again?
1186    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1187    Preamble.clear();
1188    if (CreatedPreambleBuffer)
1189      delete NewPreamble.first;
1190    if (PreambleTimer)
1191      PreambleTimer->stopTimer();
1192    TopLevelDeclsInPreamble.clear();
1193    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1194    return 0;
1195  }
1196
1197  // Keep track of the preamble we precompiled.
1198  PreambleFile = FrontendOpts.OutputFile;
1199  NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1200  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1201
1202  // Keep track of all of the files that the source manager knows about,
1203  // so we can verify whether they have changed or not.
1204  FilesInPreamble.clear();
1205  SourceManager &SourceMgr = Clang.getSourceManager();
1206  const llvm::MemoryBuffer *MainFileBuffer
1207    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1208  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1209                                     FEnd = SourceMgr.fileinfo_end();
1210       F != FEnd;
1211       ++F) {
1212    const FileEntry *File = F->second->Entry;
1213    if (!File || F->second->getRawBuffer() == MainFileBuffer)
1214      continue;
1215
1216    FilesInPreamble[File->getName()]
1217      = std::make_pair(F->second->getSize(), File->getModificationTime());
1218  }
1219
1220  if (PreambleTimer)
1221    PreambleTimer->stopTimer();
1222
1223  PreambleRebuildCounter = 1;
1224  return CreatePaddedMainFileBuffer(NewPreamble.first,
1225                                    CreatedPreambleBuffer,
1226                                    PreambleReservedSize,
1227                                    FrontendOpts.Inputs[0].second);
1228}
1229
1230void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1231  std::vector<Decl *> Resolved;
1232  Resolved.reserve(TopLevelDeclsInPreamble.size());
1233  ExternalASTSource &Source = *getASTContext().getExternalSource();
1234  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1235    // Resolve the declaration ID to an actual declaration, possibly
1236    // deserializing the declaration in the process.
1237    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1238    if (D)
1239      Resolved.push_back(D);
1240  }
1241  TopLevelDeclsInPreamble.clear();
1242  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1243}
1244
1245unsigned ASTUnit::getMaxPCHLevel() const {
1246  if (!getOnlyLocalDecls())
1247    return Decl::MaxPCHLevel;
1248
1249  unsigned Result = 0;
1250  if (isMainFileAST() || SavedMainFileBuffer)
1251    ++Result;
1252  return Result;
1253}
1254
1255ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1256                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1257                                             bool OnlyLocalDecls,
1258                                             bool CaptureDiagnostics,
1259                                             bool PrecompilePreamble,
1260                                             bool CompleteTranslationUnit,
1261                                             bool CacheCodeCompletionResults) {
1262  if (!Diags.getPtr()) {
1263    // No diagnostics engine was provided, so create our own diagnostics object
1264    // with the default options.
1265    DiagnosticOptions DiagOpts;
1266    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1267  }
1268
1269  // Create the AST unit.
1270  llvm::OwningPtr<ASTUnit> AST;
1271  AST.reset(new ASTUnit(false));
1272  AST->Diagnostics = Diags;
1273  AST->CaptureDiagnostics = CaptureDiagnostics;
1274  AST->OnlyLocalDecls = OnlyLocalDecls;
1275  AST->CompleteTranslationUnit = CompleteTranslationUnit;
1276  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1277  AST->Invocation.reset(CI);
1278  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1279
1280  if (getenv("LIBCLANG_TIMING"))
1281    AST->TimerGroup.reset(
1282                  new llvm::TimerGroup(CI->getFrontendOpts().Inputs[0].second));
1283
1284
1285  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1286  // FIXME: When C++ PCH is ready, allow use of it for a precompiled preamble.
1287  if (PrecompilePreamble && !CI->getLangOpts().CPlusPlus) {
1288    AST->PreambleRebuildCounter = 1;
1289    OverrideMainBuffer = AST->getMainBufferWithPrecompiledPreamble();
1290  }
1291
1292  llvm::Timer *ParsingTimer = 0;
1293  if (AST->TimerGroup.get()) {
1294    ParsingTimer = new llvm::Timer("Initial parse", *AST->TimerGroup);
1295    ParsingTimer->startTimer();
1296    AST->Timers.push_back(ParsingTimer);
1297  }
1298
1299  bool Failed = AST->Parse(OverrideMainBuffer);
1300  if (ParsingTimer)
1301    ParsingTimer->stopTimer();
1302
1303  return Failed? 0 : AST.take();
1304}
1305
1306ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1307                                      const char **ArgEnd,
1308                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1309                                      llvm::StringRef ResourceFilesPath,
1310                                      bool OnlyLocalDecls,
1311                                      RemappedFile *RemappedFiles,
1312                                      unsigned NumRemappedFiles,
1313                                      bool CaptureDiagnostics,
1314                                      bool PrecompilePreamble,
1315                                      bool CompleteTranslationUnit,
1316                                      bool CacheCodeCompletionResults) {
1317  if (!Diags.getPtr()) {
1318    // No diagnostics engine was provided, so create our own diagnostics object
1319    // with the default options.
1320    DiagnosticOptions DiagOpts;
1321    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1322  }
1323
1324  llvm::SmallVector<const char *, 16> Args;
1325  Args.push_back("<clang>"); // FIXME: Remove dummy argument.
1326  Args.insert(Args.end(), ArgBegin, ArgEnd);
1327
1328  // FIXME: Find a cleaner way to force the driver into restricted modes. We
1329  // also want to force it to use clang.
1330  Args.push_back("-fsyntax-only");
1331
1332  // FIXME: We shouldn't have to pass in the path info.
1333  driver::Driver TheDriver("clang", llvm::sys::getHostTriple(),
1334                           "a.out", false, false, *Diags);
1335
1336  // Don't check that inputs exist, they have been remapped.
1337  TheDriver.setCheckInputsExist(false);
1338
1339  llvm::OwningPtr<driver::Compilation> C(
1340    TheDriver.BuildCompilation(Args.size(), Args.data()));
1341
1342  // We expect to get back exactly one command job, if we didn't something
1343  // failed.
1344  const driver::JobList &Jobs = C->getJobs();
1345  if (Jobs.size() != 1 || !isa<driver::Command>(Jobs.begin())) {
1346    llvm::SmallString<256> Msg;
1347    llvm::raw_svector_ostream OS(Msg);
1348    C->PrintJob(OS, C->getJobs(), "; ", true);
1349    Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
1350    return 0;
1351  }
1352
1353  const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
1354  if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
1355    Diags->Report(diag::err_fe_expected_clang_command);
1356    return 0;
1357  }
1358
1359  const driver::ArgStringList &CCArgs = Cmd->getArguments();
1360  llvm::OwningPtr<CompilerInvocation> CI(new CompilerInvocation);
1361  CompilerInvocation::CreateFromArgs(*CI,
1362                                     const_cast<const char **>(CCArgs.data()),
1363                                     const_cast<const char **>(CCArgs.data()) +
1364                                     CCArgs.size(),
1365                                     *Diags);
1366
1367  // Override any files that need remapping
1368  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1369    CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1370                                              RemappedFiles[I].second);
1371
1372  // Override the resources path.
1373  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1374
1375  CI->getFrontendOpts().DisableFree = true;
1376  return LoadFromCompilerInvocation(CI.take(), Diags, OnlyLocalDecls,
1377                                    CaptureDiagnostics, PrecompilePreamble,
1378                                    CompleteTranslationUnit,
1379                                    CacheCodeCompletionResults);
1380}
1381
1382bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1383  if (!Invocation.get())
1384    return true;
1385
1386  llvm::Timer *ReparsingTimer = 0;
1387  if (TimerGroup.get()) {
1388    ReparsingTimer = new llvm::Timer("Reparse", *TimerGroup);
1389    ReparsingTimer->startTimer();
1390    Timers.push_back(ReparsingTimer);
1391  }
1392
1393  // Remap files.
1394  Invocation->getPreprocessorOpts().clearRemappedFiles();
1395  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1396    Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1397                                                      RemappedFiles[I].second);
1398
1399  // If we have a preamble file lying around, or if we might try to
1400  // build a precompiled preamble, do so now.
1401  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1402  if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1403    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble();
1404
1405  // Clear out the diagnostics state.
1406  if (!OverrideMainBuffer)
1407    getDiagnostics().Reset();
1408
1409  // Parse the sources
1410  bool Result = Parse(OverrideMainBuffer);
1411  if (ReparsingTimer)
1412    ReparsingTimer->stopTimer();
1413  return Result;
1414}
1415
1416//----------------------------------------------------------------------------//
1417// Code completion
1418//----------------------------------------------------------------------------//
1419
1420namespace {
1421  /// \brief Code completion consumer that combines the cached code-completion
1422  /// results from an ASTUnit with the code-completion results provided to it,
1423  /// then passes the result on to
1424  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
1425    unsigned NormalContexts;
1426    ASTUnit &AST;
1427    CodeCompleteConsumer &Next;
1428
1429  public:
1430    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
1431                                  bool IncludeMacros, bool IncludeCodePatterns,
1432                                  bool IncludeGlobals)
1433      : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
1434                             Next.isOutputBinary()), AST(AST), Next(Next)
1435    {
1436      // Compute the set of contexts in which we will look when we don't have
1437      // any information about the specific context.
1438      NormalContexts
1439        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
1440        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
1441        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
1442        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
1443        | (1 << (CodeCompletionContext::CCC_Statement - 1))
1444        | (1 << (CodeCompletionContext::CCC_Expression - 1))
1445        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
1446        | (1 << (CodeCompletionContext::CCC_MemberAccess - 1))
1447        | (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
1448
1449      if (AST.getASTContext().getLangOptions().CPlusPlus)
1450        NormalContexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1))
1451                    | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
1452                    | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
1453    }
1454
1455    virtual void ProcessCodeCompleteResults(Sema &S,
1456                                            CodeCompletionContext Context,
1457                                            Result *Results,
1458                                            unsigned NumResults);
1459
1460    virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
1461                                           OverloadCandidate *Candidates,
1462                                           unsigned NumCandidates) {
1463      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
1464    }
1465  };
1466}
1467
1468/// \brief Helper function that computes which global names are hidden by the
1469/// local code-completion results.
1470void CalculateHiddenNames(const CodeCompletionContext &Context,
1471                          CodeCompleteConsumer::Result *Results,
1472                          unsigned NumResults,
1473                          ASTContext &Ctx,
1474                          llvm::StringSet<> &HiddenNames) {
1475  bool OnlyTagNames = false;
1476  switch (Context.getKind()) {
1477  case CodeCompletionContext::CCC_Other:
1478  case CodeCompletionContext::CCC_TopLevel:
1479  case CodeCompletionContext::CCC_ObjCInterface:
1480  case CodeCompletionContext::CCC_ObjCImplementation:
1481  case CodeCompletionContext::CCC_ObjCIvarList:
1482  case CodeCompletionContext::CCC_ClassStructUnion:
1483  case CodeCompletionContext::CCC_Statement:
1484  case CodeCompletionContext::CCC_Expression:
1485  case CodeCompletionContext::CCC_ObjCMessageReceiver:
1486  case CodeCompletionContext::CCC_MemberAccess:
1487  case CodeCompletionContext::CCC_Namespace:
1488  case CodeCompletionContext::CCC_Type:
1489    break;
1490
1491  case CodeCompletionContext::CCC_EnumTag:
1492  case CodeCompletionContext::CCC_UnionTag:
1493  case CodeCompletionContext::CCC_ClassOrStructTag:
1494    OnlyTagNames = true;
1495    break;
1496
1497  case CodeCompletionContext::CCC_ObjCProtocolName:
1498    // If we're just looking for protocol names, nothing can hide them.
1499    return;
1500  }
1501
1502  typedef CodeCompleteConsumer::Result Result;
1503  for (unsigned I = 0; I != NumResults; ++I) {
1504    if (Results[I].Kind != Result::RK_Declaration)
1505      continue;
1506
1507    unsigned IDNS
1508      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
1509
1510    bool Hiding = false;
1511    if (OnlyTagNames)
1512      Hiding = (IDNS & Decl::IDNS_Tag);
1513    else {
1514      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
1515                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
1516                             Decl::IDNS_NonMemberOperator);
1517      if (Ctx.getLangOptions().CPlusPlus)
1518        HiddenIDNS |= Decl::IDNS_Tag;
1519      Hiding = (IDNS & HiddenIDNS);
1520    }
1521
1522    if (!Hiding)
1523      continue;
1524
1525    DeclarationName Name = Results[I].Declaration->getDeclName();
1526    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
1527      HiddenNames.insert(Identifier->getName());
1528    else
1529      HiddenNames.insert(Name.getAsString());
1530  }
1531}
1532
1533
1534void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
1535                                            CodeCompletionContext Context,
1536                                            Result *Results,
1537                                            unsigned NumResults) {
1538  // Merge the results we were given with the results we cached.
1539  bool AddedResult = false;
1540  unsigned InContexts
1541    = (Context.getKind() == CodeCompletionContext::CCC_Other? NormalContexts
1542                                            : (1 << (Context.getKind() - 1)));
1543
1544  // Contains the set of names that are hidden by "local" completion results.
1545  llvm::StringSet<> HiddenNames;
1546
1547  typedef CodeCompleteConsumer::Result Result;
1548  llvm::SmallVector<Result, 8> AllResults;
1549  for (ASTUnit::cached_completion_iterator
1550            C = AST.cached_completion_begin(),
1551         CEnd = AST.cached_completion_end();
1552       C != CEnd; ++C) {
1553    // If the context we are in matches any of the contexts we are
1554    // interested in, we'll add this result.
1555    if ((C->ShowInContexts & InContexts) == 0)
1556      continue;
1557
1558    // If we haven't added any results previously, do so now.
1559    if (!AddedResult) {
1560      CalculateHiddenNames(Context, Results, NumResults, S.Context,
1561                           HiddenNames);
1562      AllResults.insert(AllResults.end(), Results, Results + NumResults);
1563      AddedResult = true;
1564    }
1565
1566    // Determine whether this global completion result is hidden by a local
1567    // completion result. If so, skip it.
1568    if (C->Kind != CXCursor_MacroDefinition &&
1569        HiddenNames.count(C->Completion->getTypedText()))
1570      continue;
1571
1572    // Adjust priority based on similar type classes.
1573    unsigned Priority = C->Priority;
1574    if (!Context.getPreferredType().isNull()) {
1575      if (C->Kind == CXCursor_MacroDefinition) {
1576        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
1577                               Context.getPreferredType()->isAnyPointerType());
1578      } else if (C->Type) {
1579        CanQualType Expected
1580          = S.Context.getCanonicalType(
1581                               Context.getPreferredType().getUnqualifiedType());
1582        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
1583        if (ExpectedSTC == C->TypeClass) {
1584          // We know this type is similar; check for an exact match.
1585          llvm::StringMap<unsigned> &CachedCompletionTypes
1586            = AST.getCachedCompletionTypes();
1587          llvm::StringMap<unsigned>::iterator Pos
1588            = CachedCompletionTypes.find(QualType(Expected).getAsString());
1589          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
1590            Priority /= CCF_ExactTypeMatch;
1591          else
1592            Priority /= CCF_SimilarTypeMatch;
1593        }
1594      }
1595    }
1596
1597    AllResults.push_back(Result(C->Completion, Priority, C->Kind));
1598  }
1599
1600  // If we did not add any cached completion results, just forward the
1601  // results we were given to the next consumer.
1602  if (!AddedResult) {
1603    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
1604    return;
1605  }
1606
1607  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
1608                                  AllResults.size());
1609}
1610
1611
1612
1613void ASTUnit::CodeComplete(llvm::StringRef File, unsigned Line, unsigned Column,
1614                           RemappedFile *RemappedFiles,
1615                           unsigned NumRemappedFiles,
1616                           bool IncludeMacros,
1617                           bool IncludeCodePatterns,
1618                           CodeCompleteConsumer &Consumer,
1619                           Diagnostic &Diag, LangOptions &LangOpts,
1620                           SourceManager &SourceMgr, FileManager &FileMgr,
1621                   llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics) {
1622  if (!Invocation.get())
1623    return;
1624
1625  llvm::Timer *CompletionTimer = 0;
1626  if (TimerGroup.get()) {
1627    llvm::SmallString<128> TimerName;
1628    llvm::raw_svector_ostream TimerNameOut(TimerName);
1629    TimerNameOut << "Code completion @ " << File << ":" << Line << ":"
1630                 << Column;
1631    CompletionTimer = new llvm::Timer(TimerNameOut.str(), *TimerGroup);
1632    CompletionTimer->startTimer();
1633    Timers.push_back(CompletionTimer);
1634  }
1635
1636  CompilerInvocation CCInvocation(*Invocation);
1637  FrontendOptions &FrontendOpts = CCInvocation.getFrontendOpts();
1638  PreprocessorOptions &PreprocessorOpts = CCInvocation.getPreprocessorOpts();
1639
1640  FrontendOpts.ShowMacrosInCodeCompletion
1641    = IncludeMacros && CachedCompletionResults.empty();
1642  FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
1643  FrontendOpts.ShowGlobalSymbolsInCodeCompletion
1644    = CachedCompletionResults.empty();
1645  FrontendOpts.CodeCompletionAt.FileName = File;
1646  FrontendOpts.CodeCompletionAt.Line = Line;
1647  FrontendOpts.CodeCompletionAt.Column = Column;
1648
1649  // Turn on spell-checking when performing code completion. It leads
1650  // to better results.
1651  unsigned SpellChecking = CCInvocation.getLangOpts().SpellChecking;
1652  CCInvocation.getLangOpts().SpellChecking = 1;
1653
1654  // Set the language options appropriately.
1655  LangOpts = CCInvocation.getLangOpts();
1656
1657  CompilerInstance Clang;
1658  Clang.setInvocation(&CCInvocation);
1659  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1660
1661  // Set up diagnostics, capturing any diagnostics produced.
1662  Clang.setDiagnostics(&Diag);
1663  CaptureDroppedDiagnostics Capture(true,
1664                                    Clang.getDiagnostics(),
1665                                    StoredDiagnostics);
1666  Clang.setDiagnosticClient(Diag.getClient());
1667
1668  // Create the target instance.
1669  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1670                                               Clang.getTargetOpts()));
1671  if (!Clang.hasTarget()) {
1672    Clang.takeDiagnosticClient();
1673    Clang.takeInvocation();
1674  }
1675
1676  // Inform the target of the language options.
1677  //
1678  // FIXME: We shouldn't need to do this, the target should be immutable once
1679  // created. This complexity should be lifted elsewhere.
1680  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1681
1682  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1683         "Invocation must have exactly one source file!");
1684  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1685         "FIXME: AST inputs not yet supported here!");
1686  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1687         "IR inputs not support here!");
1688
1689
1690  // Use the source and file managers that we were given.
1691  Clang.setFileManager(&FileMgr);
1692  Clang.setSourceManager(&SourceMgr);
1693
1694  // Remap files.
1695  PreprocessorOpts.clearRemappedFiles();
1696  PreprocessorOpts.RetainRemappedFileBuffers = true;
1697  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1698    PreprocessorOpts.addRemappedFile(RemappedFiles[I].first,
1699                                     RemappedFiles[I].second);
1700
1701  // Use the code completion consumer we were given, but adding any cached
1702  // code-completion results.
1703  AugmentedCodeCompleteConsumer
1704  AugmentedConsumer(*this, Consumer, FrontendOpts.ShowMacrosInCodeCompletion,
1705                    FrontendOpts.ShowCodePatternsInCodeCompletion,
1706                    FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
1707  Clang.setCodeCompletionConsumer(&AugmentedConsumer);
1708
1709  // If we have a precompiled preamble, try to use it. We only allow
1710  // the use of the precompiled preamble if we're if the completion
1711  // point is within the main file, after the end of the precompiled
1712  // preamble.
1713  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1714  if (!PreambleFile.empty()) {
1715    using llvm::sys::FileStatus;
1716    llvm::sys::PathWithStatus CompleteFilePath(File);
1717    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
1718    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
1719      if (const FileStatus *MainStatus = MainPath.getFileStatus())
1720        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID())
1721          OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(false,
1722                                                                    Line);
1723  }
1724
1725  // If the main file has been overridden due to the use of a preamble,
1726  // make that override happen and introduce the preamble.
1727  if (OverrideMainBuffer) {
1728    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
1729    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1730    PreprocessorOpts.PrecompiledPreambleBytes.second
1731                                                    = PreambleEndsAtStartOfLine;
1732    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
1733    PreprocessorOpts.DisablePCHValidation = true;
1734
1735    // The stored diagnostics have the old source manager. Copy them
1736    // to our output set of stored diagnostics, updating the source
1737    // manager to the one we were given.
1738    for (unsigned I = 0, N = this->StoredDiagnostics.size(); I != N; ++I) {
1739      StoredDiagnostics.push_back(this->StoredDiagnostics[I]);
1740      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SourceMgr);
1741      StoredDiagnostics[I].setLocation(Loc);
1742    }
1743  }
1744
1745  llvm::OwningPtr<SyntaxOnlyAction> Act;
1746  Act.reset(new SyntaxOnlyAction);
1747  if (Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1748                           Clang.getFrontendOpts().Inputs[0].first)) {
1749    Act->Execute();
1750    Act->EndSourceFile();
1751  }
1752
1753  if (CompletionTimer)
1754    CompletionTimer->stopTimer();
1755
1756  // Steal back our resources.
1757  delete OverrideMainBuffer;
1758  Clang.takeFileManager();
1759  Clang.takeSourceManager();
1760  Clang.takeInvocation();
1761  Clang.takeDiagnosticClient();
1762  Clang.takeCodeCompletionConsumer();
1763  CCInvocation.getLangOpts().SpellChecking = SpellChecking;
1764}
1765
1766bool ASTUnit::Save(llvm::StringRef File) {
1767  if (getDiagnostics().hasErrorOccurred())
1768    return true;
1769
1770  // FIXME: Can we somehow regenerate the stat cache here, or do we need to
1771  // unconditionally create a stat cache when we parse the file?
1772  std::string ErrorInfo;
1773  llvm::raw_fd_ostream Out(File.str().c_str(), ErrorInfo,
1774                           llvm::raw_fd_ostream::F_Binary);
1775  if (!ErrorInfo.empty() || Out.has_error())
1776    return true;
1777
1778  std::vector<unsigned char> Buffer;
1779  llvm::BitstreamWriter Stream(Buffer);
1780  PCHWriter Writer(Stream);
1781  Writer.WritePCH(getSema(), 0, 0);
1782
1783  // Write the generated bitstream to "Out".
1784  Out.write((char *)&Buffer.front(), Buffer.size());
1785  Out.close();
1786  return Out.has_error();
1787}
1788