ASTUnit.cpp revision 875ab10245d3bf37252dd822aa1616bb0a391095 
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/AST/ASTContext.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/TypeOrdering.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/Serialization/ASTReader.h"
29#include "clang/Serialization/ASTWriter.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/ADT/StringSet.h"
36#include "llvm/Support/MemoryBuffer.h"
37#include "llvm/System/Host.h"
38#include "llvm/System/Path.h"
39#include "llvm/Support/raw_ostream.h"
40#include "llvm/Support/Timer.h"
41#include <cstdlib>
42#include <cstdio>
43#include <sys/stat.h>
44using namespace clang;
45
46/// \brief After failing to build a precompiled preamble (due to
47/// errors in the source that occurs in the preamble), the number of
48/// reparses during which we'll skip even trying to precompile the
49/// preamble.
50const unsigned DefaultPreambleRebuildInterval = 5;
51
52ASTUnit::ASTUnit(bool _MainFileIsAST)
53  : CaptureDiagnostics(false), MainFileIsAST(_MainFileIsAST),
54    CompleteTranslationUnit(true), ConcurrencyCheckValue(CheckUnlocked),
55    PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
56    ShouldCacheCodeCompletionResults(false),
57    NumTopLevelDeclsAtLastCompletionCache(0),
58    CacheCodeCompletionCoolDown(0),
59    UnsafeToFree(false) {
60}
61
62ASTUnit::~ASTUnit() {
63  ConcurrencyCheckValue = CheckLocked;
64  CleanTemporaryFiles();
65  if (!PreambleFile.empty())
66    llvm::sys::Path(PreambleFile).eraseFromDisk();
67
68  // Free the buffers associated with remapped files. We are required to
69  // perform this operation here because we explicitly request that the
70  // compiler instance *not* free these buffers for each invocation of the
71  // parser.
72  if (Invocation.get()) {
73    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
74    for (PreprocessorOptions::remapped_file_buffer_iterator
75           FB = PPOpts.remapped_file_buffer_begin(),
76           FBEnd = PPOpts.remapped_file_buffer_end();
77         FB != FBEnd;
78         ++FB)
79      delete FB->second;
80  }
81
82  delete SavedMainFileBuffer;
83  delete PreambleBuffer;
84
85  ClearCachedCompletionResults();
86
87  for (unsigned I = 0, N = Timers.size(); I != N; ++I)
88    delete Timers[I];
89}
90
91void ASTUnit::CleanTemporaryFiles() {
92  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
93    TemporaryFiles[I].eraseFromDisk();
94  TemporaryFiles.clear();
95}
96
97/// \brief Determine the set of code-completion contexts in which this
98/// declaration should be shown.
99static unsigned getDeclShowContexts(NamedDecl *ND,
100                                    const LangOptions &LangOpts,
101                                    bool &IsNestedNameSpecifier) {
102  IsNestedNameSpecifier = false;
103
104  if (isa<UsingShadowDecl>(ND))
105    ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
106  if (!ND)
107    return 0;
108
109  unsigned Contexts = 0;
110  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
111      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
112    // Types can appear in these contexts.
113    if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
114      Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
115                | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
116                | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
117                | (1 << (CodeCompletionContext::CCC_Statement - 1))
118                | (1 << (CodeCompletionContext::CCC_Type - 1));
119
120    // In C++, types can appear in expressions contexts (for functional casts).
121    if (LangOpts.CPlusPlus)
122      Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
123
124    // In Objective-C, message sends can send interfaces. In Objective-C++,
125    // all types are available due to functional casts.
126    if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
127      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
128
129    // Deal with tag names.
130    if (isa<EnumDecl>(ND)) {
131      Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
132
133      // Part of the nested-name-specifier in C++0x.
134      if (LangOpts.CPlusPlus0x)
135        IsNestedNameSpecifier = true;
136    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
137      if (Record->isUnion())
138        Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
139      else
140        Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
141
142      if (LangOpts.CPlusPlus)
143        IsNestedNameSpecifier = true;
144    } else if (isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND))
145      IsNestedNameSpecifier = true;
146  } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
147    // Values can appear in these contexts.
148    Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
149             | (1 << (CodeCompletionContext::CCC_Expression - 1))
150             | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
151  } else if (isa<ObjCProtocolDecl>(ND)) {
152    Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
153  } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
154    Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
155
156    // Part of the nested-name-specifier.
157    IsNestedNameSpecifier = true;
158  }
159
160  return Contexts;
161}
162
163void ASTUnit::CacheCodeCompletionResults() {
164  if (!TheSema)
165    return;
166
167  llvm::Timer *CachingTimer = 0;
168  if (TimerGroup.get()) {
169    CachingTimer = new llvm::Timer("Cache global code completions",
170                                   *TimerGroup);
171    CachingTimer->startTimer();
172    Timers.push_back(CachingTimer);
173  }
174
175  // Clear out the previous results.
176  ClearCachedCompletionResults();
177
178  // Gather the set of global code completions.
179  typedef CodeCompleteConsumer::Result Result;
180  llvm::SmallVector<Result, 8> Results;
181  TheSema->GatherGlobalCodeCompletions(Results);
182
183  // Translate global code completions into cached completions.
184  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
185
186  for (unsigned I = 0, N = Results.size(); I != N; ++I) {
187    switch (Results[I].Kind) {
188    case Result::RK_Declaration: {
189      bool IsNestedNameSpecifier = false;
190      CachedCodeCompletionResult CachedResult;
191      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
192      CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
193                                                        Ctx->getLangOptions(),
194                                                        IsNestedNameSpecifier);
195      CachedResult.Priority = Results[I].Priority;
196      CachedResult.Kind = Results[I].CursorKind;
197
198      // Keep track of the type of this completion in an ASTContext-agnostic
199      // way.
200      QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
201      if (UsageType.isNull()) {
202        CachedResult.TypeClass = STC_Void;
203        CachedResult.Type = 0;
204      } else {
205        CanQualType CanUsageType
206          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
207        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
208
209        // Determine whether we have already seen this type. If so, we save
210        // ourselves the work of formatting the type string by using the
211        // temporary, CanQualType-based hash table to find the associated value.
212        unsigned &TypeValue = CompletionTypes[CanUsageType];
213        if (TypeValue == 0) {
214          TypeValue = CompletionTypes.size();
215          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
216            = TypeValue;
217        }
218
219        CachedResult.Type = TypeValue;
220      }
221
222      CachedCompletionResults.push_back(CachedResult);
223
224      /// Handle nested-name-specifiers in C++.
225      if (TheSema->Context.getLangOptions().CPlusPlus &&
226          IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
227        // The contexts in which a nested-name-specifier can appear in C++.
228        unsigned NNSContexts
229          = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
230          | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
231          | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
232          | (1 << (CodeCompletionContext::CCC_Statement - 1))
233          | (1 << (CodeCompletionContext::CCC_Expression - 1))
234          | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
235          | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
236          | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
237          | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
238          | (1 << (CodeCompletionContext::CCC_Type - 1));
239
240        if (isa<NamespaceDecl>(Results[I].Declaration) ||
241            isa<NamespaceAliasDecl>(Results[I].Declaration))
242          NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
243
244        if (unsigned RemainingContexts
245                                = NNSContexts & ~CachedResult.ShowInContexts) {
246          // If there any contexts where this completion can be a
247          // nested-name-specifier but isn't already an option, create a
248          // nested-name-specifier completion.
249          Results[I].StartsNestedNameSpecifier = true;
250          CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
251          CachedResult.ShowInContexts = RemainingContexts;
252          CachedResult.Priority = CCP_NestedNameSpecifier;
253          CachedResult.TypeClass = STC_Void;
254          CachedResult.Type = 0;
255          CachedCompletionResults.push_back(CachedResult);
256        }
257      }
258      break;
259    }
260
261    case Result::RK_Keyword:
262    case Result::RK_Pattern:
263      // Ignore keywords and patterns; we don't care, since they are so
264      // easily regenerated.
265      break;
266
267    case Result::RK_Macro: {
268      CachedCodeCompletionResult CachedResult;
269      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
270      CachedResult.ShowInContexts
271        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
272        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
273        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
274        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
275        | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
276        | (1 << (CodeCompletionContext::CCC_Statement - 1))
277        | (1 << (CodeCompletionContext::CCC_Expression - 1))
278        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
279      CachedResult.Priority = Results[I].Priority;
280      CachedResult.Kind = Results[I].CursorKind;
281      CachedResult.TypeClass = STC_Void;
282      CachedResult.Type = 0;
283      CachedCompletionResults.push_back(CachedResult);
284      break;
285    }
286    }
287    Results[I].Destroy();
288  }
289
290  if (CachingTimer)
291    CachingTimer->stopTimer();
292
293  // Make a note of the state when we performed this caching.
294  NumTopLevelDeclsAtLastCompletionCache = top_level_size();
295  CacheCodeCompletionCoolDown = 15;
296}
297
298void ASTUnit::ClearCachedCompletionResults() {
299  for (unsigned I = 0, N = CachedCompletionResults.size(); I != N; ++I)
300    delete CachedCompletionResults[I].Completion;
301  CachedCompletionResults.clear();
302  CachedCompletionTypes.clear();
303}
304
305namespace {
306
307/// \brief Gathers information from ASTReader that will be used to initialize
308/// a Preprocessor.
309class ASTInfoCollector : public ASTReaderListener {
310  LangOptions &LangOpt;
311  HeaderSearch &HSI;
312  std::string &TargetTriple;
313  std::string &Predefines;
314  unsigned &Counter;
315
316  unsigned NumHeaderInfos;
317
318public:
319  ASTInfoCollector(LangOptions &LangOpt, HeaderSearch &HSI,
320                   std::string &TargetTriple, std::string &Predefines,
321                   unsigned &Counter)
322    : LangOpt(LangOpt), HSI(HSI), TargetTriple(TargetTriple),
323      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0) {}
324
325  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
326    LangOpt = LangOpts;
327    return false;
328  }
329
330  virtual bool ReadTargetTriple(llvm::StringRef Triple) {
331    TargetTriple = Triple;
332    return false;
333  }
334
335  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
336                                    llvm::StringRef OriginalFileName,
337                                    std::string &SuggestedPredefines) {
338    Predefines = Buffers[0].Data;
339    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
340      Predefines += Buffers[I].Data;
341    }
342    return false;
343  }
344
345  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
346    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
347  }
348
349  virtual void ReadCounter(unsigned Value) {
350    Counter = Value;
351  }
352};
353
354class StoredDiagnosticClient : public DiagnosticClient {
355  llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags;
356
357public:
358  explicit StoredDiagnosticClient(
359                          llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
360    : StoredDiags(StoredDiags) { }
361
362  virtual void HandleDiagnostic(Diagnostic::Level Level,
363                                const DiagnosticInfo &Info);
364};
365
366/// \brief RAII object that optionally captures diagnostics, if
367/// there is no diagnostic client to capture them already.
368class CaptureDroppedDiagnostics {
369  Diagnostic &Diags;
370  StoredDiagnosticClient Client;
371  DiagnosticClient *PreviousClient;
372
373public:
374  CaptureDroppedDiagnostics(bool RequestCapture, Diagnostic &Diags,
375                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
376    : Diags(Diags), Client(StoredDiags), PreviousClient(0)
377  {
378    if (RequestCapture || Diags.getClient() == 0) {
379      PreviousClient = Diags.takeClient();
380      Diags.setClient(&Client);
381    }
382  }
383
384  ~CaptureDroppedDiagnostics() {
385    if (Diags.getClient() == &Client) {
386      Diags.takeClient();
387      Diags.setClient(PreviousClient);
388    }
389  }
390};
391
392} // anonymous namespace
393
394void StoredDiagnosticClient::HandleDiagnostic(Diagnostic::Level Level,
395                                              const DiagnosticInfo &Info) {
396  StoredDiags.push_back(StoredDiagnostic(Level, Info));
397}
398
399const std::string &ASTUnit::getOriginalSourceFileName() {
400  return OriginalSourceFile;
401}
402
403const std::string &ASTUnit::getASTFileName() {
404  assert(isMainFileAST() && "Not an ASTUnit from an AST file!");
405  return static_cast<ASTReader *>(Ctx->getExternalSource())->getFileName();
406}
407
408ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
409                                  llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
410                                  bool OnlyLocalDecls,
411                                  RemappedFile *RemappedFiles,
412                                  unsigned NumRemappedFiles,
413                                  bool CaptureDiagnostics) {
414  llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
415
416  if (!Diags.getPtr()) {
417    // No diagnostics engine was provided, so create our own diagnostics object
418    // with the default options.
419    DiagnosticOptions DiagOpts;
420    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
421  }
422
423  AST->CaptureDiagnostics = CaptureDiagnostics;
424  AST->OnlyLocalDecls = OnlyLocalDecls;
425  AST->Diagnostics = Diags;
426  AST->FileMgr.reset(new FileManager);
427  AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics()));
428  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
429
430  // If requested, capture diagnostics in the ASTUnit.
431  CaptureDroppedDiagnostics Capture(CaptureDiagnostics, AST->getDiagnostics(),
432                                    AST->StoredDiagnostics);
433
434  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
435    // Create the file entry for the file that we're mapping from.
436    const FileEntry *FromFile
437      = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
438                                    RemappedFiles[I].second->getBufferSize(),
439                                             0);
440    if (!FromFile) {
441      AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
442        << RemappedFiles[I].first;
443      delete RemappedFiles[I].second;
444      continue;
445    }
446
447    // Override the contents of the "from" file with the contents of
448    // the "to" file.
449    AST->getSourceManager().overrideFileContents(FromFile,
450                                                 RemappedFiles[I].second);
451  }
452
453  // Gather Info for preprocessor construction later on.
454
455  LangOptions LangInfo;
456  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
457  std::string TargetTriple;
458  std::string Predefines;
459  unsigned Counter;
460
461  llvm::OwningPtr<ASTReader> Reader;
462
463  Reader.reset(new ASTReader(AST->getSourceManager(), AST->getFileManager(),
464                             AST->getDiagnostics()));
465  Reader->setListener(new ASTInfoCollector(LangInfo, HeaderInfo, TargetTriple,
466                                           Predefines, Counter));
467
468  switch (Reader->ReadAST(Filename)) {
469  case ASTReader::Success:
470    break;
471
472  case ASTReader::Failure:
473  case ASTReader::IgnorePCH:
474    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
475    return NULL;
476  }
477
478  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
479
480  // AST file loaded successfully. Now create the preprocessor.
481
482  // Get information about the target being compiled for.
483  //
484  // FIXME: This is broken, we should store the TargetOptions in the AST file.
485  TargetOptions TargetOpts;
486  TargetOpts.ABI = "";
487  TargetOpts.CXXABI = "";
488  TargetOpts.CPU = "";
489  TargetOpts.Features.clear();
490  TargetOpts.Triple = TargetTriple;
491  AST->Target.reset(TargetInfo::CreateTargetInfo(AST->getDiagnostics(),
492                                                 TargetOpts));
493  AST->PP.reset(new Preprocessor(AST->getDiagnostics(), LangInfo,
494                                 *AST->Target.get(),
495                                 AST->getSourceManager(), HeaderInfo));
496  Preprocessor &PP = *AST->PP.get();
497
498  PP.setPredefines(Reader->getSuggestedPredefines());
499  PP.setCounterValue(Counter);
500  Reader->setPreprocessor(PP);
501
502  // Create and initialize the ASTContext.
503
504  AST->Ctx.reset(new ASTContext(LangInfo,
505                                AST->getSourceManager(),
506                                *AST->Target.get(),
507                                PP.getIdentifierTable(),
508                                PP.getSelectorTable(),
509                                PP.getBuiltinInfo(),
510                                /* size_reserve = */0));
511  ASTContext &Context = *AST->Ctx.get();
512
513  Reader->InitializeContext(Context);
514
515  // Attach the AST reader to the AST context as an external AST
516  // source, so that declarations will be deserialized from the
517  // AST file as needed.
518  ASTReader *ReaderPtr = Reader.get();
519  llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
520  Context.setExternalSource(Source);
521
522  // Create an AST consumer, even though it isn't used.
523  AST->Consumer.reset(new ASTConsumer);
524
525  // Create a semantic analysis object and tell the AST reader about it.
526  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
527  AST->TheSema->Initialize();
528  ReaderPtr->InitializeSema(*AST->TheSema);
529
530  return AST.take();
531}
532
533namespace {
534
535class TopLevelDeclTrackerConsumer : public ASTConsumer {
536  ASTUnit &Unit;
537
538public:
539  TopLevelDeclTrackerConsumer(ASTUnit &_Unit) : Unit(_Unit) {}
540
541  void HandleTopLevelDecl(DeclGroupRef D) {
542    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
543      Decl *D = *it;
544      // FIXME: Currently ObjC method declarations are incorrectly being
545      // reported as top-level declarations, even though their DeclContext
546      // is the containing ObjC @interface/@implementation.  This is a
547      // fundamental problem in the parser right now.
548      if (isa<ObjCMethodDecl>(D))
549        continue;
550      Unit.addTopLevelDecl(D);
551    }
552  }
553
554  // We're not interested in "interesting" decls.
555  void HandleInterestingDecl(DeclGroupRef) {}
556};
557
558class TopLevelDeclTrackerAction : public ASTFrontendAction {
559public:
560  ASTUnit &Unit;
561
562  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
563                                         llvm::StringRef InFile) {
564    return new TopLevelDeclTrackerConsumer(Unit);
565  }
566
567public:
568  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
569
570  virtual bool hasCodeCompletionSupport() const { return false; }
571  virtual bool usesCompleteTranslationUnit()  {
572    return Unit.isCompleteTranslationUnit();
573  }
574};
575
576class PrecompilePreambleConsumer : public PCHGenerator {
577  ASTUnit &Unit;
578  std::vector<Decl *> TopLevelDecls;
579
580public:
581  PrecompilePreambleConsumer(ASTUnit &Unit,
582                             const Preprocessor &PP, bool Chaining,
583                             const char *isysroot, llvm::raw_ostream *Out)
584    : PCHGenerator(PP, Chaining, isysroot, Out), Unit(Unit) { }
585
586  virtual void HandleTopLevelDecl(DeclGroupRef D) {
587    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
588      Decl *D = *it;
589      // FIXME: Currently ObjC method declarations are incorrectly being
590      // reported as top-level declarations, even though their DeclContext
591      // is the containing ObjC @interface/@implementation.  This is a
592      // fundamental problem in the parser right now.
593      if (isa<ObjCMethodDecl>(D))
594        continue;
595      TopLevelDecls.push_back(D);
596    }
597  }
598
599  virtual void HandleTranslationUnit(ASTContext &Ctx) {
600    PCHGenerator::HandleTranslationUnit(Ctx);
601    if (!Unit.getDiagnostics().hasErrorOccurred()) {
602      // Translate the top-level declarations we captured during
603      // parsing into declaration IDs in the precompiled
604      // preamble. This will allow us to deserialize those top-level
605      // declarations when requested.
606      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
607        Unit.addTopLevelDeclFromPreamble(
608                                      getWriter().getDeclID(TopLevelDecls[I]));
609    }
610  }
611};
612
613class PrecompilePreambleAction : public ASTFrontendAction {
614  ASTUnit &Unit;
615
616public:
617  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
618
619  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
620                                         llvm::StringRef InFile) {
621    std::string Sysroot;
622    llvm::raw_ostream *OS = 0;
623    bool Chaining;
624    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
625                                                       OS, Chaining))
626      return 0;
627
628    const char *isysroot = CI.getFrontendOpts().RelocatablePCH ?
629                             Sysroot.c_str() : 0;
630    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Chaining,
631                                          isysroot, OS);
632  }
633
634  virtual bool hasCodeCompletionSupport() const { return false; }
635  virtual bool hasASTFileSupport() const { return false; }
636  virtual bool usesCompleteTranslationUnit() { return false; }
637};
638
639}
640
641/// Parse the source file into a translation unit using the given compiler
642/// invocation, replacing the current translation unit.
643///
644/// \returns True if a failure occurred that causes the ASTUnit not to
645/// contain any translation-unit information, false otherwise.
646bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
647  delete SavedMainFileBuffer;
648  SavedMainFileBuffer = 0;
649
650  if (!Invocation.get()) {
651    delete OverrideMainBuffer;
652    return true;
653  }
654
655  // Create the compiler instance to use for building the AST.
656  CompilerInstance Clang;
657  Clang.setInvocation(Invocation.take());
658  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
659
660  // Set up diagnostics, capturing any diagnostics that would
661  // otherwise be dropped.
662  Clang.setDiagnostics(&getDiagnostics());
663  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
664                                    getDiagnostics(),
665                                    StoredDiagnostics);
666
667  // Create the target instance.
668  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
669                                               Clang.getTargetOpts()));
670  if (!Clang.hasTarget()) {
671    delete OverrideMainBuffer;
672    return true;
673  }
674
675  // Inform the target of the language options.
676  //
677  // FIXME: We shouldn't need to do this, the target should be immutable once
678  // created. This complexity should be lifted elsewhere.
679  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
680
681  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
682         "Invocation must have exactly one source file!");
683  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
684         "FIXME: AST inputs not yet supported here!");
685  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
686         "IR inputs not support here!");
687
688  // Configure the various subsystems.
689  // FIXME: Should we retain the previous file manager?
690  FileMgr.reset(new FileManager);
691  SourceMgr.reset(new SourceManager(getDiagnostics()));
692  TheSema.reset();
693  Ctx.reset();
694  PP.reset();
695
696  // Clear out old caches and data.
697  TopLevelDecls.clear();
698  CleanTemporaryFiles();
699  PreprocessedEntitiesByFile.clear();
700
701  if (!OverrideMainBuffer) {
702    StoredDiagnostics.clear();
703    TopLevelDeclsInPreamble.clear();
704  }
705
706  // Create a file manager object to provide access to and cache the filesystem.
707  Clang.setFileManager(&getFileManager());
708
709  // Create the source manager.
710  Clang.setSourceManager(&getSourceManager());
711
712  // If the main file has been overridden due to the use of a preamble,
713  // make that override happen and introduce the preamble.
714  PreprocessorOptions &PreprocessorOpts = Clang.getPreprocessorOpts();
715  std::string PriorImplicitPCHInclude;
716  if (OverrideMainBuffer) {
717    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
718    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
719    PreprocessorOpts.PrecompiledPreambleBytes.second
720                                                    = PreambleEndsAtStartOfLine;
721    PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
722    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
723    PreprocessorOpts.DisablePCHValidation = true;
724
725    // Keep track of the override buffer;
726    SavedMainFileBuffer = OverrideMainBuffer;
727
728    // The stored diagnostic has the old source manager in it; update
729    // the locations to refer into the new source manager. Since we've
730    // been careful to make sure that the source manager's state
731    // before and after are identical, so that we can reuse the source
732    // location itself.
733    for (unsigned I = 0, N = StoredDiagnostics.size(); I != N; ++I) {
734      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
735                        getSourceManager());
736      StoredDiagnostics[I].setLocation(Loc);
737    }
738  } else {
739    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
740    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
741  }
742
743  llvm::OwningPtr<TopLevelDeclTrackerAction> Act;
744  Act.reset(new TopLevelDeclTrackerAction(*this));
745  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
746                            Clang.getFrontendOpts().Inputs[0].first))
747    goto error;
748
749  Act->Execute();
750
751  // Steal the created target, context, and preprocessor, and take back the
752  // source and file managers.
753  TheSema.reset(Clang.takeSema());
754  Consumer.reset(Clang.takeASTConsumer());
755  Ctx.reset(Clang.takeASTContext());
756  PP.reset(Clang.takePreprocessor());
757  Clang.takeSourceManager();
758  Clang.takeFileManager();
759  Target.reset(Clang.takeTarget());
760
761  Act->EndSourceFile();
762
763  // Remove the overridden buffer we used for the preamble.
764  if (OverrideMainBuffer) {
765    PreprocessorOpts.eraseRemappedFile(
766                               PreprocessorOpts.remapped_file_buffer_end() - 1);
767    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
768  }
769
770  Invocation.reset(Clang.takeInvocation());
771
772  // If we were asked to cache code-completion results and don't have any
773  // results yet, do so now.
774  if (ShouldCacheCodeCompletionResults && CachedCompletionResults.empty())
775    CacheCodeCompletionResults();
776
777  return false;
778
779error:
780  // Remove the overridden buffer we used for the preamble.
781  if (OverrideMainBuffer) {
782    PreprocessorOpts.eraseRemappedFile(
783                               PreprocessorOpts.remapped_file_buffer_end() - 1);
784    PreprocessorOpts.DisablePCHValidation = true;
785    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
786    delete OverrideMainBuffer;
787  }
788
789  Clang.takeSourceManager();
790  Clang.takeFileManager();
791  Invocation.reset(Clang.takeInvocation());
792  return true;
793}
794
795/// \brief Simple function to retrieve a path for a preamble precompiled header.
796static std::string GetPreamblePCHPath() {
797  // FIXME: This is lame; sys::Path should provide this function (in particular,
798  // it should know how to find the temporary files dir).
799  // FIXME: This is really lame. I copied this code from the Driver!
800  std::string Error;
801  const char *TmpDir = ::getenv("TMPDIR");
802  if (!TmpDir)
803    TmpDir = ::getenv("TEMP");
804  if (!TmpDir)
805    TmpDir = ::getenv("TMP");
806  if (!TmpDir)
807    TmpDir = "/tmp";
808  llvm::sys::Path P(TmpDir);
809  P.appendComponent("preamble");
810  P.appendSuffix("pch");
811  if (P.createTemporaryFileOnDisk())
812    return std::string();
813
814  return P.str();
815}
816
817/// \brief Compute the preamble for the main file, providing the source buffer
818/// that corresponds to the main file along with a pair (bytes, start-of-line)
819/// that describes the preamble.
820std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
821ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
822                         unsigned MaxLines, bool &CreatedBuffer) {
823  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
824  PreprocessorOptions &PreprocessorOpts
825    = Invocation.getPreprocessorOpts();
826  CreatedBuffer = false;
827
828  // Try to determine if the main file has been remapped, either from the
829  // command line (to another file) or directly through the compiler invocation
830  // (to a memory buffer).
831  llvm::MemoryBuffer *Buffer = 0;
832  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
833  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
834    // Check whether there is a file-file remapping of the main file
835    for (PreprocessorOptions::remapped_file_iterator
836          M = PreprocessorOpts.remapped_file_begin(),
837          E = PreprocessorOpts.remapped_file_end();
838         M != E;
839         ++M) {
840      llvm::sys::PathWithStatus MPath(M->first);
841      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
842        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
843          // We found a remapping. Try to load the resulting, remapped source.
844          if (CreatedBuffer) {
845            delete Buffer;
846            CreatedBuffer = false;
847          }
848
849          Buffer = llvm::MemoryBuffer::getFile(M->second);
850          if (!Buffer)
851            return std::make_pair((llvm::MemoryBuffer*)0,
852                                  std::make_pair(0, true));
853          CreatedBuffer = true;
854
855          // Remove this remapping. We've captured the buffer already.
856          M = PreprocessorOpts.eraseRemappedFile(M);
857          E = PreprocessorOpts.remapped_file_end();
858          if (M == E)
859            break;
860        }
861      }
862    }
863
864    // Check whether there is a file-buffer remapping. It supercedes the
865    // file-file remapping.
866    for (PreprocessorOptions::remapped_file_buffer_iterator
867           M = PreprocessorOpts.remapped_file_buffer_begin(),
868           E = PreprocessorOpts.remapped_file_buffer_end();
869         M != E;
870         ++M) {
871      llvm::sys::PathWithStatus MPath(M->first);
872      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
873        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
874          // We found a remapping.
875          if (CreatedBuffer) {
876            delete Buffer;
877            CreatedBuffer = false;
878          }
879
880          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
881
882          // Remove this remapping. We've captured the buffer already.
883          M = PreprocessorOpts.eraseRemappedFile(M);
884          E = PreprocessorOpts.remapped_file_buffer_end();
885          if (M == E)
886            break;
887        }
888      }
889    }
890  }
891
892  // If the main source file was not remapped, load it now.
893  if (!Buffer) {
894    Buffer = llvm::MemoryBuffer::getFile(FrontendOpts.Inputs[0].second);
895    if (!Buffer)
896      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
897
898    CreatedBuffer = true;
899  }
900
901  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer, MaxLines));
902}
903
904static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
905                                                      bool DeleteOld,
906                                                      unsigned NewSize,
907                                                      llvm::StringRef NewName) {
908  llvm::MemoryBuffer *Result
909    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
910  memcpy(const_cast<char*>(Result->getBufferStart()),
911         Old->getBufferStart(), Old->getBufferSize());
912  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
913         ' ', NewSize - Old->getBufferSize() - 1);
914  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
915
916  if (DeleteOld)
917    delete Old;
918
919  return Result;
920}
921
922/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
923/// the source file.
924///
925/// This routine will compute the preamble of the main source file. If a
926/// non-trivial preamble is found, it will precompile that preamble into a
927/// precompiled header so that the precompiled preamble can be used to reduce
928/// reparsing time. If a precompiled preamble has already been constructed,
929/// this routine will determine if it is still valid and, if so, avoid
930/// rebuilding the precompiled preamble.
931///
932/// \param AllowRebuild When true (the default), this routine is
933/// allowed to rebuild the precompiled preamble if it is found to be
934/// out-of-date.
935///
936/// \param MaxLines When non-zero, the maximum number of lines that
937/// can occur within the preamble.
938///
939/// \returns If the precompiled preamble can be used, returns a newly-allocated
940/// buffer that should be used in place of the main file when doing so.
941/// Otherwise, returns a NULL pointer.
942llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
943                                          CompilerInvocation PreambleInvocation,
944                                                           bool AllowRebuild,
945                                                           unsigned MaxLines) {
946  FrontendOptions &FrontendOpts = PreambleInvocation.getFrontendOpts();
947  PreprocessorOptions &PreprocessorOpts
948    = PreambleInvocation.getPreprocessorOpts();
949
950  bool CreatedPreambleBuffer = false;
951  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
952    = ComputePreamble(PreambleInvocation, MaxLines, CreatedPreambleBuffer);
953
954  if (!NewPreamble.second.first) {
955    // We couldn't find a preamble in the main source. Clear out the current
956    // preamble, if we have one. It's obviously no good any more.
957    Preamble.clear();
958    if (!PreambleFile.empty()) {
959      llvm::sys::Path(PreambleFile).eraseFromDisk();
960      PreambleFile.clear();
961    }
962    if (CreatedPreambleBuffer)
963      delete NewPreamble.first;
964
965    // The next time we actually see a preamble, precompile it.
966    PreambleRebuildCounter = 1;
967    return 0;
968  }
969
970  if (!Preamble.empty()) {
971    // We've previously computed a preamble. Check whether we have the same
972    // preamble now that we did before, and that there's enough space in
973    // the main-file buffer within the precompiled preamble to fit the
974    // new main file.
975    if (Preamble.size() == NewPreamble.second.first &&
976        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
977        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
978        memcmp(&Preamble[0], NewPreamble.first->getBufferStart(),
979               NewPreamble.second.first) == 0) {
980      // The preamble has not changed. We may be able to re-use the precompiled
981      // preamble.
982
983      // Check that none of the files used by the preamble have changed.
984      bool AnyFileChanged = false;
985
986      // First, make a record of those files that have been overridden via
987      // remapping or unsaved_files.
988      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
989      for (PreprocessorOptions::remapped_file_iterator
990                R = PreprocessorOpts.remapped_file_begin(),
991             REnd = PreprocessorOpts.remapped_file_end();
992           !AnyFileChanged && R != REnd;
993           ++R) {
994        struct stat StatBuf;
995        if (stat(R->second.c_str(), &StatBuf)) {
996          // If we can't stat the file we're remapping to, assume that something
997          // horrible happened.
998          AnyFileChanged = true;
999          break;
1000        }
1001
1002        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
1003                                                   StatBuf.st_mtime);
1004      }
1005      for (PreprocessorOptions::remapped_file_buffer_iterator
1006                R = PreprocessorOpts.remapped_file_buffer_begin(),
1007             REnd = PreprocessorOpts.remapped_file_buffer_end();
1008           !AnyFileChanged && R != REnd;
1009           ++R) {
1010        // FIXME: Should we actually compare the contents of file->buffer
1011        // remappings?
1012        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
1013                                                   0);
1014      }
1015
1016      // Check whether anything has changed.
1017      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
1018             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1019           !AnyFileChanged && F != FEnd;
1020           ++F) {
1021        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1022          = OverriddenFiles.find(F->first());
1023        if (Overridden != OverriddenFiles.end()) {
1024          // This file was remapped; check whether the newly-mapped file
1025          // matches up with the previous mapping.
1026          if (Overridden->second != F->second)
1027            AnyFileChanged = true;
1028          continue;
1029        }
1030
1031        // The file was not remapped; check whether it has changed on disk.
1032        struct stat StatBuf;
1033        if (stat(F->first(), &StatBuf)) {
1034          // If we can't stat the file, assume that something horrible happened.
1035          AnyFileChanged = true;
1036        } else if (StatBuf.st_size != F->second.first ||
1037                   StatBuf.st_mtime != F->second.second)
1038          AnyFileChanged = true;
1039      }
1040
1041      if (!AnyFileChanged) {
1042        // Okay! We can re-use the precompiled preamble.
1043
1044        // Set the state of the diagnostic object to mimic its state
1045        // after parsing the preamble.
1046        getDiagnostics().Reset();
1047        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1048        if (StoredDiagnostics.size() > NumStoredDiagnosticsInPreamble)
1049          StoredDiagnostics.erase(
1050            StoredDiagnostics.begin() + NumStoredDiagnosticsInPreamble,
1051                                  StoredDiagnostics.end());
1052
1053        // Create a version of the main file buffer that is padded to
1054        // buffer size we reserved when creating the preamble.
1055        return CreatePaddedMainFileBuffer(NewPreamble.first,
1056                                          CreatedPreambleBuffer,
1057                                          PreambleReservedSize,
1058                                          FrontendOpts.Inputs[0].second);
1059      }
1060    }
1061
1062    // If we aren't allowed to rebuild the precompiled preamble, just
1063    // return now.
1064    if (!AllowRebuild)
1065      return 0;
1066
1067    // We can't reuse the previously-computed preamble. Build a new one.
1068    Preamble.clear();
1069    llvm::sys::Path(PreambleFile).eraseFromDisk();
1070    PreambleRebuildCounter = 1;
1071  } else if (!AllowRebuild) {
1072    // We aren't allowed to rebuild the precompiled preamble; just
1073    // return now.
1074    return 0;
1075  }
1076
1077  // If the preamble rebuild counter > 1, it's because we previously
1078  // failed to build a preamble and we're not yet ready to try
1079  // again. Decrement the counter and return a failure.
1080  if (PreambleRebuildCounter > 1) {
1081    --PreambleRebuildCounter;
1082    return 0;
1083  }
1084
1085  // We did not previously compute a preamble, or it can't be reused anyway.
1086  llvm::Timer *PreambleTimer = 0;
1087  if (TimerGroup.get()) {
1088    PreambleTimer = new llvm::Timer("Precompiling preamble", *TimerGroup);
1089    PreambleTimer->startTimer();
1090    Timers.push_back(PreambleTimer);
1091  }
1092
1093  // Create a new buffer that stores the preamble. The buffer also contains
1094  // extra space for the original contents of the file (which will be present
1095  // when we actually parse the file) along with more room in case the file
1096  // grows.
1097  PreambleReservedSize = NewPreamble.first->getBufferSize();
1098  if (PreambleReservedSize < 4096)
1099    PreambleReservedSize = 8191;
1100  else
1101    PreambleReservedSize *= 2;
1102
1103  // Save the preamble text for later; we'll need to compare against it for
1104  // subsequent reparses.
1105  Preamble.assign(NewPreamble.first->getBufferStart(),
1106                  NewPreamble.first->getBufferStart()
1107                                                  + NewPreamble.second.first);
1108  PreambleEndsAtStartOfLine = NewPreamble.second.second;
1109
1110  delete PreambleBuffer;
1111  PreambleBuffer
1112    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1113                                                FrontendOpts.Inputs[0].second);
1114  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1115         NewPreamble.first->getBufferStart(), Preamble.size());
1116  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1117         ' ', PreambleReservedSize - Preamble.size() - 1);
1118  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1119
1120  // Remap the main source file to the preamble buffer.
1121  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1122  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1123
1124  // Tell the compiler invocation to generate a temporary precompiled header.
1125  FrontendOpts.ProgramAction = frontend::GeneratePCH;
1126  // FIXME: Set ChainedPCH unconditionally, once it is ready.
1127  if (::getenv("LIBCLANG_CHAINING"))
1128    FrontendOpts.ChainedPCH = true;
1129  // FIXME: Generate the precompiled header into memory?
1130  FrontendOpts.OutputFile = GetPreamblePCHPath();
1131
1132  // Create the compiler instance to use for building the precompiled preamble.
1133  CompilerInstance Clang;
1134  Clang.setInvocation(&PreambleInvocation);
1135  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1136
1137  // Set up diagnostics, capturing all of the diagnostics produced.
1138  Clang.setDiagnostics(&getDiagnostics());
1139  CaptureDroppedDiagnostics Capture(CaptureDiagnostics,
1140                                    getDiagnostics(),
1141                                    StoredDiagnostics);
1142
1143  // Create the target instance.
1144  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1145                                               Clang.getTargetOpts()));
1146  if (!Clang.hasTarget()) {
1147    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1148    Preamble.clear();
1149    if (CreatedPreambleBuffer)
1150      delete NewPreamble.first;
1151    if (PreambleTimer)
1152      PreambleTimer->stopTimer();
1153    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1154    PreprocessorOpts.eraseRemappedFile(
1155                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1156    return 0;
1157  }
1158
1159  // Inform the target of the language options.
1160  //
1161  // FIXME: We shouldn't need to do this, the target should be immutable once
1162  // created. This complexity should be lifted elsewhere.
1163  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1164
1165  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1166         "Invocation must have exactly one source file!");
1167  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1168         "FIXME: AST inputs not yet supported here!");
1169  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1170         "IR inputs not support here!");
1171
1172  // Clear out old caches and data.
1173  StoredDiagnostics.clear();
1174  TopLevelDecls.clear();
1175  TopLevelDeclsInPreamble.clear();
1176
1177  // Create a file manager object to provide access to and cache the filesystem.
1178  Clang.setFileManager(new FileManager);
1179
1180  // Create the source manager.
1181  Clang.setSourceManager(new SourceManager(getDiagnostics()));
1182
1183  llvm::OwningPtr<PrecompilePreambleAction> Act;
1184  Act.reset(new PrecompilePreambleAction(*this));
1185  if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1186                            Clang.getFrontendOpts().Inputs[0].first)) {
1187    Clang.takeInvocation();
1188    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1189    Preamble.clear();
1190    if (CreatedPreambleBuffer)
1191      delete NewPreamble.first;
1192    if (PreambleTimer)
1193      PreambleTimer->stopTimer();
1194    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1195    PreprocessorOpts.eraseRemappedFile(
1196                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1197    return 0;
1198  }
1199
1200  Act->Execute();
1201  Act->EndSourceFile();
1202  Clang.takeInvocation();
1203
1204  if (Diagnostics->hasErrorOccurred()) {
1205    // There were errors parsing the preamble, so no precompiled header was
1206    // generated. Forget that we even tried.
1207    // FIXME: Should we leave a note for ourselves to try again?
1208    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1209    Preamble.clear();
1210    if (CreatedPreambleBuffer)
1211      delete NewPreamble.first;
1212    if (PreambleTimer)
1213      PreambleTimer->stopTimer();
1214    TopLevelDeclsInPreamble.clear();
1215    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1216    PreprocessorOpts.eraseRemappedFile(
1217                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1218    return 0;
1219  }
1220
1221  // Keep track of the preamble we precompiled.
1222  PreambleFile = FrontendOpts.OutputFile;
1223  NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1224  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1225
1226  // Keep track of all of the files that the source manager knows about,
1227  // so we can verify whether they have changed or not.
1228  FilesInPreamble.clear();
1229  SourceManager &SourceMgr = Clang.getSourceManager();
1230  const llvm::MemoryBuffer *MainFileBuffer
1231    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1232  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1233                                     FEnd = SourceMgr.fileinfo_end();
1234       F != FEnd;
1235       ++F) {
1236    const FileEntry *File = F->second->Entry;
1237    if (!File || F->second->getRawBuffer() == MainFileBuffer)
1238      continue;
1239
1240    FilesInPreamble[File->getName()]
1241      = std::make_pair(F->second->getSize(), File->getModificationTime());
1242  }
1243
1244  if (PreambleTimer)
1245    PreambleTimer->stopTimer();
1246
1247  PreambleRebuildCounter = 1;
1248  PreprocessorOpts.eraseRemappedFile(
1249                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1250  return CreatePaddedMainFileBuffer(NewPreamble.first,
1251                                    CreatedPreambleBuffer,
1252                                    PreambleReservedSize,
1253                                    FrontendOpts.Inputs[0].second);
1254}
1255
1256void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1257  std::vector<Decl *> Resolved;
1258  Resolved.reserve(TopLevelDeclsInPreamble.size());
1259  ExternalASTSource &Source = *getASTContext().getExternalSource();
1260  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1261    // Resolve the declaration ID to an actual declaration, possibly
1262    // deserializing the declaration in the process.
1263    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1264    if (D)
1265      Resolved.push_back(D);
1266  }
1267  TopLevelDeclsInPreamble.clear();
1268  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1269}
1270
1271unsigned ASTUnit::getMaxPCHLevel() const {
1272  if (!getOnlyLocalDecls())
1273    return Decl::MaxPCHLevel;
1274
1275  unsigned Result = 0;
1276  if (isMainFileAST() || SavedMainFileBuffer)
1277    ++Result;
1278  return Result;
1279}
1280
1281ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1282                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1283                                             bool OnlyLocalDecls,
1284                                             bool CaptureDiagnostics,
1285                                             bool PrecompilePreamble,
1286                                             bool CompleteTranslationUnit,
1287                                             bool CacheCodeCompletionResults) {
1288  if (!Diags.getPtr()) {
1289    // No diagnostics engine was provided, so create our own diagnostics object
1290    // with the default options.
1291    DiagnosticOptions DiagOpts;
1292    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1293  }
1294
1295  // Create the AST unit.
1296  llvm::OwningPtr<ASTUnit> AST;
1297  AST.reset(new ASTUnit(false));
1298  AST->Diagnostics = Diags;
1299  AST->CaptureDiagnostics = CaptureDiagnostics;
1300  AST->OnlyLocalDecls = OnlyLocalDecls;
1301  AST->CompleteTranslationUnit = CompleteTranslationUnit;
1302  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1303  AST->Invocation.reset(CI);
1304  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1305
1306  if (getenv("LIBCLANG_TIMING"))
1307    AST->TimerGroup.reset(
1308                  new llvm::TimerGroup(CI->getFrontendOpts().Inputs[0].second));
1309
1310
1311  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1312  // FIXME: When C++ PCH is ready, allow use of it for a precompiled preamble.
1313  if (PrecompilePreamble && !CI->getLangOpts().CPlusPlus) {
1314    AST->PreambleRebuildCounter = 1;
1315    OverrideMainBuffer
1316      = AST->getMainBufferWithPrecompiledPreamble(*AST->Invocation);
1317  }
1318
1319  llvm::Timer *ParsingTimer = 0;
1320  if (AST->TimerGroup.get()) {
1321    ParsingTimer = new llvm::Timer("Initial parse", *AST->TimerGroup);
1322    ParsingTimer->startTimer();
1323    AST->Timers.push_back(ParsingTimer);
1324  }
1325
1326  bool Failed = AST->Parse(OverrideMainBuffer);
1327  if (ParsingTimer)
1328    ParsingTimer->stopTimer();
1329
1330  return Failed? 0 : AST.take();
1331}
1332
1333ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1334                                      const char **ArgEnd,
1335                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1336                                      llvm::StringRef ResourceFilesPath,
1337                                      bool OnlyLocalDecls,
1338                                      RemappedFile *RemappedFiles,
1339                                      unsigned NumRemappedFiles,
1340                                      bool CaptureDiagnostics,
1341                                      bool PrecompilePreamble,
1342                                      bool CompleteTranslationUnit,
1343                                      bool CacheCodeCompletionResults) {
1344  bool CreatedDiagnosticsObject = false;
1345
1346  if (!Diags.getPtr()) {
1347    // No diagnostics engine was provided, so create our own diagnostics object
1348    // with the default options.
1349    DiagnosticOptions DiagOpts;
1350    Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1351    CreatedDiagnosticsObject = true;
1352  }
1353
1354  llvm::SmallVector<const char *, 16> Args;
1355  Args.push_back("<clang>"); // FIXME: Remove dummy argument.
1356  Args.insert(Args.end(), ArgBegin, ArgEnd);
1357
1358  // FIXME: Find a cleaner way to force the driver into restricted modes. We
1359  // also want to force it to use clang.
1360  Args.push_back("-fsyntax-only");
1361
1362  // FIXME: We shouldn't have to pass in the path info.
1363  driver::Driver TheDriver("clang", llvm::sys::getHostTriple(),
1364                           "a.out", false, false, *Diags);
1365
1366  // Don't check that inputs exist, they have been remapped.
1367  TheDriver.setCheckInputsExist(false);
1368
1369  llvm::OwningPtr<driver::Compilation> C(
1370    TheDriver.BuildCompilation(Args.size(), Args.data()));
1371
1372  // We expect to get back exactly one command job, if we didn't something
1373  // failed.
1374  const driver::JobList &Jobs = C->getJobs();
1375  if (Jobs.size() != 1 || !isa<driver::Command>(Jobs.begin())) {
1376    llvm::SmallString<256> Msg;
1377    llvm::raw_svector_ostream OS(Msg);
1378    C->PrintJob(OS, C->getJobs(), "; ", true);
1379    Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
1380    return 0;
1381  }
1382
1383  const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
1384  if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
1385    Diags->Report(diag::err_fe_expected_clang_command);
1386    return 0;
1387  }
1388
1389  const driver::ArgStringList &CCArgs = Cmd->getArguments();
1390  llvm::OwningPtr<CompilerInvocation> CI(new CompilerInvocation);
1391  CompilerInvocation::CreateFromArgs(*CI,
1392                                     const_cast<const char **>(CCArgs.data()),
1393                                     const_cast<const char **>(CCArgs.data()) +
1394                                     CCArgs.size(),
1395                                     *Diags);
1396
1397  // Override any files that need remapping
1398  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1399    CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1400                                              RemappedFiles[I].second);
1401
1402  // Override the resources path.
1403  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1404
1405  CI->getFrontendOpts().DisableFree = false;
1406  return LoadFromCompilerInvocation(CI.take(), Diags, OnlyLocalDecls,
1407                                    CaptureDiagnostics, PrecompilePreamble,
1408                                    CompleteTranslationUnit,
1409                                    CacheCodeCompletionResults);
1410}
1411
1412bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1413  if (!Invocation.get())
1414    return true;
1415
1416  llvm::Timer *ReparsingTimer = 0;
1417  if (TimerGroup.get()) {
1418    ReparsingTimer = new llvm::Timer("Reparse", *TimerGroup);
1419    ReparsingTimer->startTimer();
1420    Timers.push_back(ReparsingTimer);
1421  }
1422
1423  // Remap files.
1424  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1425  for (PreprocessorOptions::remapped_file_buffer_iterator
1426         R = PPOpts.remapped_file_buffer_begin(),
1427         REnd = PPOpts.remapped_file_buffer_end();
1428       R != REnd;
1429       ++R) {
1430    delete R->second;
1431  }
1432  Invocation->getPreprocessorOpts().clearRemappedFiles();
1433  for (unsigned I = 0; I != NumRemappedFiles; ++I)
1434    Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1435                                                      RemappedFiles[I].second);
1436
1437  // If we have a preamble file lying around, or if we might try to
1438  // build a precompiled preamble, do so now.
1439  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1440  if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1441    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
1442
1443  // Clear out the diagnostics state.
1444  if (!OverrideMainBuffer)
1445    getDiagnostics().Reset();
1446
1447  // Parse the sources
1448  bool Result = Parse(OverrideMainBuffer);
1449  if (ReparsingTimer)
1450    ReparsingTimer->stopTimer();
1451
1452  if (ShouldCacheCodeCompletionResults) {
1453    if (CacheCodeCompletionCoolDown > 0)
1454      --CacheCodeCompletionCoolDown;
1455    else if (top_level_size() != NumTopLevelDeclsAtLastCompletionCache)
1456      CacheCodeCompletionResults();
1457  }
1458
1459  return Result;
1460}
1461
1462//----------------------------------------------------------------------------//
1463// Code completion
1464//----------------------------------------------------------------------------//
1465
1466namespace {
1467  /// \brief Code completion consumer that combines the cached code-completion
1468  /// results from an ASTUnit with the code-completion results provided to it,
1469  /// then passes the result on to
1470  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
1471    unsigned NormalContexts;
1472    ASTUnit &AST;
1473    CodeCompleteConsumer &Next;
1474
1475  public:
1476    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
1477                                  bool IncludeMacros, bool IncludeCodePatterns,
1478                                  bool IncludeGlobals)
1479      : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
1480                             Next.isOutputBinary()), AST(AST), Next(Next)
1481    {
1482      // Compute the set of contexts in which we will look when we don't have
1483      // any information about the specific context.
1484      NormalContexts
1485        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
1486        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
1487        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
1488        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
1489        | (1 << (CodeCompletionContext::CCC_Statement - 1))
1490        | (1 << (CodeCompletionContext::CCC_Expression - 1))
1491        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
1492        | (1 << (CodeCompletionContext::CCC_MemberAccess - 1))
1493        | (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
1494
1495      if (AST.getASTContext().getLangOptions().CPlusPlus)
1496        NormalContexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1))
1497                    | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
1498                    | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
1499    }
1500
1501    virtual void ProcessCodeCompleteResults(Sema &S,
1502                                            CodeCompletionContext Context,
1503                                            Result *Results,
1504                                            unsigned NumResults);
1505
1506    virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
1507                                           OverloadCandidate *Candidates,
1508                                           unsigned NumCandidates) {
1509      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
1510    }
1511  };
1512}
1513
1514/// \brief Helper function that computes which global names are hidden by the
1515/// local code-completion results.
1516void CalculateHiddenNames(const CodeCompletionContext &Context,
1517                          CodeCompleteConsumer::Result *Results,
1518                          unsigned NumResults,
1519                          ASTContext &Ctx,
1520                          llvm::StringSet<> &HiddenNames) {
1521  bool OnlyTagNames = false;
1522  switch (Context.getKind()) {
1523  case CodeCompletionContext::CCC_Other:
1524  case CodeCompletionContext::CCC_TopLevel:
1525  case CodeCompletionContext::CCC_ObjCInterface:
1526  case CodeCompletionContext::CCC_ObjCImplementation:
1527  case CodeCompletionContext::CCC_ObjCIvarList:
1528  case CodeCompletionContext::CCC_ClassStructUnion:
1529  case CodeCompletionContext::CCC_Statement:
1530  case CodeCompletionContext::CCC_Expression:
1531  case CodeCompletionContext::CCC_ObjCMessageReceiver:
1532  case CodeCompletionContext::CCC_MemberAccess:
1533  case CodeCompletionContext::CCC_Namespace:
1534  case CodeCompletionContext::CCC_Type:
1535    break;
1536
1537  case CodeCompletionContext::CCC_EnumTag:
1538  case CodeCompletionContext::CCC_UnionTag:
1539  case CodeCompletionContext::CCC_ClassOrStructTag:
1540    OnlyTagNames = true;
1541    break;
1542
1543  case CodeCompletionContext::CCC_ObjCProtocolName:
1544    // If we're just looking for protocol names, nothing can hide them.
1545    return;
1546  }
1547
1548  typedef CodeCompleteConsumer::Result Result;
1549  for (unsigned I = 0; I != NumResults; ++I) {
1550    if (Results[I].Kind != Result::RK_Declaration)
1551      continue;
1552
1553    unsigned IDNS
1554      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
1555
1556    bool Hiding = false;
1557    if (OnlyTagNames)
1558      Hiding = (IDNS & Decl::IDNS_Tag);
1559    else {
1560      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
1561                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
1562                             Decl::IDNS_NonMemberOperator);
1563      if (Ctx.getLangOptions().CPlusPlus)
1564        HiddenIDNS |= Decl::IDNS_Tag;
1565      Hiding = (IDNS & HiddenIDNS);
1566    }
1567
1568    if (!Hiding)
1569      continue;
1570
1571    DeclarationName Name = Results[I].Declaration->getDeclName();
1572    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
1573      HiddenNames.insert(Identifier->getName());
1574    else
1575      HiddenNames.insert(Name.getAsString());
1576  }
1577}
1578
1579
1580void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
1581                                            CodeCompletionContext Context,
1582                                            Result *Results,
1583                                            unsigned NumResults) {
1584  // Merge the results we were given with the results we cached.
1585  bool AddedResult = false;
1586  unsigned InContexts
1587    = (Context.getKind() == CodeCompletionContext::CCC_Other? NormalContexts
1588                                            : (1 << (Context.getKind() - 1)));
1589
1590  // Contains the set of names that are hidden by "local" completion results.
1591  llvm::StringSet<> HiddenNames;
1592
1593  typedef CodeCompleteConsumer::Result Result;
1594  llvm::SmallVector<Result, 8> AllResults;
1595  for (ASTUnit::cached_completion_iterator
1596            C = AST.cached_completion_begin(),
1597         CEnd = AST.cached_completion_end();
1598       C != CEnd; ++C) {
1599    // If the context we are in matches any of the contexts we are
1600    // interested in, we'll add this result.
1601    if ((C->ShowInContexts & InContexts) == 0)
1602      continue;
1603
1604    // If we haven't added any results previously, do so now.
1605    if (!AddedResult) {
1606      CalculateHiddenNames(Context, Results, NumResults, S.Context,
1607                           HiddenNames);
1608      AllResults.insert(AllResults.end(), Results, Results + NumResults);
1609      AddedResult = true;
1610    }
1611
1612    // Determine whether this global completion result is hidden by a local
1613    // completion result. If so, skip it.
1614    if (C->Kind != CXCursor_MacroDefinition &&
1615        HiddenNames.count(C->Completion->getTypedText()))
1616      continue;
1617
1618    // Adjust priority based on similar type classes.
1619    unsigned Priority = C->Priority;
1620    if (!Context.getPreferredType().isNull()) {
1621      if (C->Kind == CXCursor_MacroDefinition) {
1622        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
1623                               Context.getPreferredType()->isAnyPointerType());
1624      } else if (C->Type) {
1625        CanQualType Expected
1626          = S.Context.getCanonicalType(
1627                               Context.getPreferredType().getUnqualifiedType());
1628        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
1629        if (ExpectedSTC == C->TypeClass) {
1630          // We know this type is similar; check for an exact match.
1631          llvm::StringMap<unsigned> &CachedCompletionTypes
1632            = AST.getCachedCompletionTypes();
1633          llvm::StringMap<unsigned>::iterator Pos
1634            = CachedCompletionTypes.find(QualType(Expected).getAsString());
1635          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
1636            Priority /= CCF_ExactTypeMatch;
1637          else
1638            Priority /= CCF_SimilarTypeMatch;
1639        }
1640      }
1641    }
1642
1643    AllResults.push_back(Result(C->Completion, Priority, C->Kind));
1644  }
1645
1646  // If we did not add any cached completion results, just forward the
1647  // results we were given to the next consumer.
1648  if (!AddedResult) {
1649    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
1650    return;
1651  }
1652
1653  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
1654                                  AllResults.size());
1655}
1656
1657
1658
1659void ASTUnit::CodeComplete(llvm::StringRef File, unsigned Line, unsigned Column,
1660                           RemappedFile *RemappedFiles,
1661                           unsigned NumRemappedFiles,
1662                           bool IncludeMacros,
1663                           bool IncludeCodePatterns,
1664                           CodeCompleteConsumer &Consumer,
1665                           Diagnostic &Diag, LangOptions &LangOpts,
1666                           SourceManager &SourceMgr, FileManager &FileMgr,
1667                   llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
1668             llvm::SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
1669  if (!Invocation.get())
1670    return;
1671
1672  llvm::Timer *CompletionTimer = 0;
1673  if (TimerGroup.get()) {
1674    llvm::SmallString<128> TimerName;
1675    llvm::raw_svector_ostream TimerNameOut(TimerName);
1676    TimerNameOut << "Code completion @ " << File << ":" << Line << ":"
1677                 << Column;
1678    CompletionTimer = new llvm::Timer(TimerNameOut.str(), *TimerGroup);
1679    CompletionTimer->startTimer();
1680    Timers.push_back(CompletionTimer);
1681  }
1682
1683  CompilerInvocation CCInvocation(*Invocation);
1684  FrontendOptions &FrontendOpts = CCInvocation.getFrontendOpts();
1685  PreprocessorOptions &PreprocessorOpts = CCInvocation.getPreprocessorOpts();
1686
1687  FrontendOpts.ShowMacrosInCodeCompletion
1688    = IncludeMacros && CachedCompletionResults.empty();
1689  FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
1690  FrontendOpts.ShowGlobalSymbolsInCodeCompletion
1691    = CachedCompletionResults.empty();
1692  FrontendOpts.CodeCompletionAt.FileName = File;
1693  FrontendOpts.CodeCompletionAt.Line = Line;
1694  FrontendOpts.CodeCompletionAt.Column = Column;
1695
1696  // Turn on spell-checking when performing code completion. It leads
1697  // to better results.
1698  unsigned SpellChecking = CCInvocation.getLangOpts().SpellChecking;
1699  CCInvocation.getLangOpts().SpellChecking = 1;
1700
1701  // Set the language options appropriately.
1702  LangOpts = CCInvocation.getLangOpts();
1703
1704  CompilerInstance Clang;
1705  Clang.setInvocation(&CCInvocation);
1706  OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1707
1708  // Set up diagnostics, capturing any diagnostics produced.
1709  Clang.setDiagnostics(&Diag);
1710  CaptureDroppedDiagnostics Capture(true,
1711                                    Clang.getDiagnostics(),
1712                                    StoredDiagnostics);
1713
1714  // Create the target instance.
1715  Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1716                                               Clang.getTargetOpts()));
1717  if (!Clang.hasTarget()) {
1718    Clang.takeInvocation();
1719    CCInvocation.getLangOpts().SpellChecking = SpellChecking;
1720    return;
1721  }
1722
1723  // Inform the target of the language options.
1724  //
1725  // FIXME: We shouldn't need to do this, the target should be immutable once
1726  // created. This complexity should be lifted elsewhere.
1727  Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1728
1729  assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1730         "Invocation must have exactly one source file!");
1731  assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1732         "FIXME: AST inputs not yet supported here!");
1733  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1734         "IR inputs not support here!");
1735
1736
1737  // Use the source and file managers that we were given.
1738  Clang.setFileManager(&FileMgr);
1739  Clang.setSourceManager(&SourceMgr);
1740
1741  // Remap files.
1742  PreprocessorOpts.clearRemappedFiles();
1743  PreprocessorOpts.RetainRemappedFileBuffers = true;
1744  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1745    PreprocessorOpts.addRemappedFile(RemappedFiles[I].first,
1746                                     RemappedFiles[I].second);
1747    OwnedBuffers.push_back(RemappedFiles[I].second);
1748  }
1749
1750  // Use the code completion consumer we were given, but adding any cached
1751  // code-completion results.
1752  AugmentedCodeCompleteConsumer
1753  AugmentedConsumer(*this, Consumer, FrontendOpts.ShowMacrosInCodeCompletion,
1754                    FrontendOpts.ShowCodePatternsInCodeCompletion,
1755                    FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
1756  Clang.setCodeCompletionConsumer(&AugmentedConsumer);
1757
1758  // If we have a precompiled preamble, try to use it. We only allow
1759  // the use of the precompiled preamble if we're if the completion
1760  // point is within the main file, after the end of the precompiled
1761  // preamble.
1762  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1763  if (!PreambleFile.empty()) {
1764    using llvm::sys::FileStatus;
1765    llvm::sys::PathWithStatus CompleteFilePath(File);
1766    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
1767    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
1768      if (const FileStatus *MainStatus = MainPath.getFileStatus())
1769        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID())
1770          OverrideMainBuffer
1771            = getMainBufferWithPrecompiledPreamble(CCInvocation, false, Line);
1772  }
1773
1774  // If the main file has been overridden due to the use of a preamble,
1775  // make that override happen and introduce the preamble.
1776  if (OverrideMainBuffer) {
1777    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
1778    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1779    PreprocessorOpts.PrecompiledPreambleBytes.second
1780                                                    = PreambleEndsAtStartOfLine;
1781    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
1782    PreprocessorOpts.DisablePCHValidation = true;
1783
1784    // The stored diagnostics have the old source manager. Copy them
1785    // to our output set of stored diagnostics, updating the source
1786    // manager to the one we were given.
1787    for (unsigned I = 0, N = this->StoredDiagnostics.size(); I != N; ++I) {
1788      StoredDiagnostics.push_back(this->StoredDiagnostics[I]);
1789      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SourceMgr);
1790      StoredDiagnostics[I].setLocation(Loc);
1791    }
1792
1793    OwnedBuffers.push_back(OverrideMainBuffer);
1794  } else {
1795    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1796    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1797  }
1798
1799  llvm::OwningPtr<SyntaxOnlyAction> Act;
1800  Act.reset(new SyntaxOnlyAction);
1801  if (Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1802                           Clang.getFrontendOpts().Inputs[0].first)) {
1803    Act->Execute();
1804    Act->EndSourceFile();
1805  }
1806
1807  if (CompletionTimer)
1808    CompletionTimer->stopTimer();
1809
1810  // Steal back our resources.
1811  Clang.takeFileManager();
1812  Clang.takeSourceManager();
1813  Clang.takeInvocation();
1814  Clang.takeCodeCompletionConsumer();
1815  CCInvocation.getLangOpts().SpellChecking = SpellChecking;
1816}
1817
1818bool ASTUnit::Save(llvm::StringRef File) {
1819  if (getDiagnostics().hasErrorOccurred())
1820    return true;
1821
1822  // FIXME: Can we somehow regenerate the stat cache here, or do we need to
1823  // unconditionally create a stat cache when we parse the file?
1824  std::string ErrorInfo;
1825  llvm::raw_fd_ostream Out(File.str().c_str(), ErrorInfo,
1826                           llvm::raw_fd_ostream::F_Binary);
1827  if (!ErrorInfo.empty() || Out.has_error())
1828    return true;
1829
1830  std::vector<unsigned char> Buffer;
1831  llvm::BitstreamWriter Stream(Buffer);
1832  ASTWriter Writer(Stream);
1833  Writer.WriteAST(getSema(), 0, 0);
1834
1835  // Write the generated bitstream to "Out".
1836  if (!Buffer.empty())
1837    Out.write((char *)&Buffer.front(), Buffer.size());
1838  Out.close();
1839  return Out.has_error();
1840}
1841