ASTUnit.cpp revision c04bb926ef693c94560da254e87926e93bb9c92f 
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/Frontend/CompilerInstance.h"
21#include "clang/Frontend/FrontendActions.h"
22#include "clang/Frontend/FrontendDiagnostic.h"
23#include "clang/Frontend/FrontendOptions.h"
24#include "clang/Frontend/MultiplexConsumer.h"
25#include "clang/Frontend/Utils.h"
26#include "clang/Serialization/ASTReader.h"
27#include "clang/Serialization/ASTWriter.h"
28#include "clang/Lex/HeaderSearch.h"
29#include "clang/Lex/Preprocessor.h"
30#include "clang/Basic/TargetOptions.h"
31#include "clang/Basic/TargetInfo.h"
32#include "clang/Basic/Diagnostic.h"
33#include "llvm/ADT/ArrayRef.h"
34#include "llvm/ADT/StringExtras.h"
35#include "llvm/ADT/StringSet.h"
36#include "llvm/Support/Atomic.h"
37#include "llvm/Support/MemoryBuffer.h"
38#include "llvm/Support/Host.h"
39#include "llvm/Support/Path.h"
40#include "llvm/Support/raw_ostream.h"
41#include "llvm/Support/Timer.h"
42#include "llvm/Support/FileSystem.h"
43#include "llvm/Support/Mutex.h"
44#include "llvm/Support/MutexGuard.h"
45#include "llvm/Support/CrashRecoveryContext.h"
46#include <cstdlib>
47#include <cstdio>
48#include <sys/stat.h>
49using namespace clang;
50
51using llvm::TimeRecord;
52
53namespace {
54  class SimpleTimer {
55    bool WantTiming;
56    TimeRecord Start;
57    std::string Output;
58
59  public:
60    explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
61      if (WantTiming)
62        Start = TimeRecord::getCurrentTime();
63    }
64
65    void setOutput(const Twine &Output) {
66      if (WantTiming)
67        this->Output = Output.str();
68    }
69
70    ~SimpleTimer() {
71      if (WantTiming) {
72        TimeRecord Elapsed = TimeRecord::getCurrentTime();
73        Elapsed -= Start;
74        llvm::errs() << Output << ':';
75        Elapsed.print(Elapsed, llvm::errs());
76        llvm::errs() << '\n';
77      }
78    }
79  };
80
81  struct OnDiskData {
82    /// \brief The file in which the precompiled preamble is stored.
83    std::string PreambleFile;
84
85    /// \brief Temporary files that should be removed when the ASTUnit is
86    /// destroyed.
87    SmallVector<llvm::sys::Path, 4> TemporaryFiles;
88
89    /// \brief Erase temporary files.
90    void CleanTemporaryFiles();
91
92    /// \brief Erase the preamble file.
93    void CleanPreambleFile();
94
95    /// \brief Erase temporary files and the preamble file.
96    void Cleanup();
97  };
98}
99
100static llvm::sys::SmartMutex<false> &getOnDiskMutex() {
101  static llvm::sys::SmartMutex<false> M(/* recursive = */ true);
102  return M;
103}
104
105static void cleanupOnDiskMapAtExit(void);
106
107typedef llvm::DenseMap<const ASTUnit *, OnDiskData *> OnDiskDataMap;
108static OnDiskDataMap &getOnDiskDataMap() {
109  static OnDiskDataMap M;
110  static bool hasRegisteredAtExit = false;
111  if (!hasRegisteredAtExit) {
112    hasRegisteredAtExit = true;
113    atexit(cleanupOnDiskMapAtExit);
114  }
115  return M;
116}
117
118static void cleanupOnDiskMapAtExit(void) {
119  // Use the mutex because there can be an alive thread destroying an ASTUnit.
120  llvm::MutexGuard Guard(getOnDiskMutex());
121  OnDiskDataMap &M = getOnDiskDataMap();
122  for (OnDiskDataMap::iterator I = M.begin(), E = M.end(); I != E; ++I) {
123    // We don't worry about freeing the memory associated with OnDiskDataMap.
124    // All we care about is erasing stale files.
125    I->second->Cleanup();
126  }
127}
128
129static OnDiskData &getOnDiskData(const ASTUnit *AU) {
130  // We require the mutex since we are modifying the structure of the
131  // DenseMap.
132  llvm::MutexGuard Guard(getOnDiskMutex());
133  OnDiskDataMap &M = getOnDiskDataMap();
134  OnDiskData *&D = M[AU];
135  if (!D)
136    D = new OnDiskData();
137  return *D;
138}
139
140static void erasePreambleFile(const ASTUnit *AU) {
141  getOnDiskData(AU).CleanPreambleFile();
142}
143
144static void removeOnDiskEntry(const ASTUnit *AU) {
145  // We require the mutex since we are modifying the structure of the
146  // DenseMap.
147  llvm::MutexGuard Guard(getOnDiskMutex());
148  OnDiskDataMap &M = getOnDiskDataMap();
149  OnDiskDataMap::iterator I = M.find(AU);
150  if (I != M.end()) {
151    I->second->Cleanup();
152    delete I->second;
153    M.erase(AU);
154  }
155}
156
157static void setPreambleFile(const ASTUnit *AU, llvm::StringRef preambleFile) {
158  getOnDiskData(AU).PreambleFile = preambleFile;
159}
160
161static const std::string &getPreambleFile(const ASTUnit *AU) {
162  return getOnDiskData(AU).PreambleFile;
163}
164
165void OnDiskData::CleanTemporaryFiles() {
166  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
167    TemporaryFiles[I].eraseFromDisk();
168  TemporaryFiles.clear();
169}
170
171void OnDiskData::CleanPreambleFile() {
172  if (!PreambleFile.empty()) {
173    llvm::sys::Path(PreambleFile).eraseFromDisk();
174    PreambleFile.clear();
175  }
176}
177
178void OnDiskData::Cleanup() {
179  CleanTemporaryFiles();
180  CleanPreambleFile();
181}
182
183void ASTUnit::clearFileLevelDecls() {
184  for (FileDeclsTy::iterator
185         I = FileDecls.begin(), E = FileDecls.end(); I != E; ++I)
186    delete I->second;
187  FileDecls.clear();
188}
189
190void ASTUnit::CleanTemporaryFiles() {
191  getOnDiskData(this).CleanTemporaryFiles();
192}
193
194void ASTUnit::addTemporaryFile(const llvm::sys::Path &TempFile) {
195  getOnDiskData(this).TemporaryFiles.push_back(TempFile);
196}
197
198/// \brief After failing to build a precompiled preamble (due to
199/// errors in the source that occurs in the preamble), the number of
200/// reparses during which we'll skip even trying to precompile the
201/// preamble.
202const unsigned DefaultPreambleRebuildInterval = 5;
203
204/// \brief Tracks the number of ASTUnit objects that are currently active.
205///
206/// Used for debugging purposes only.
207static llvm::sys::cas_flag ActiveASTUnitObjects;
208
209ASTUnit::ASTUnit(bool _MainFileIsAST)
210  : Reader(0), OnlyLocalDecls(false), CaptureDiagnostics(false),
211    MainFileIsAST(_MainFileIsAST),
212    TUKind(TU_Complete), WantTiming(getenv("LIBCLANG_TIMING")),
213    OwnsRemappedFileBuffers(true),
214    NumStoredDiagnosticsFromDriver(0),
215    PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
216    NumWarningsInPreamble(0),
217    ShouldCacheCodeCompletionResults(false),
218    IncludeBriefCommentsInCodeCompletion(false), UserFilesAreVolatile(false),
219    CompletionCacheTopLevelHashValue(0),
220    PreambleTopLevelHashValue(0),
221    CurrentTopLevelHashValue(0),
222    UnsafeToFree(false) {
223  if (getenv("LIBCLANG_OBJTRACKING")) {
224    llvm::sys::AtomicIncrement(&ActiveASTUnitObjects);
225    fprintf(stderr, "+++ %d translation units\n", ActiveASTUnitObjects);
226  }
227}
228
229ASTUnit::~ASTUnit() {
230  clearFileLevelDecls();
231
232  // Clean up the temporary files and the preamble file.
233  removeOnDiskEntry(this);
234
235  // Free the buffers associated with remapped files. We are required to
236  // perform this operation here because we explicitly request that the
237  // compiler instance *not* free these buffers for each invocation of the
238  // parser.
239  if (Invocation.getPtr() && OwnsRemappedFileBuffers) {
240    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
241    for (PreprocessorOptions::remapped_file_buffer_iterator
242           FB = PPOpts.remapped_file_buffer_begin(),
243           FBEnd = PPOpts.remapped_file_buffer_end();
244         FB != FBEnd;
245         ++FB)
246      delete FB->second;
247  }
248
249  delete SavedMainFileBuffer;
250  delete PreambleBuffer;
251
252  ClearCachedCompletionResults();
253
254  if (getenv("LIBCLANG_OBJTRACKING")) {
255    llvm::sys::AtomicDecrement(&ActiveASTUnitObjects);
256    fprintf(stderr, "--- %d translation units\n", ActiveASTUnitObjects);
257  }
258}
259
260void ASTUnit::setPreprocessor(Preprocessor *pp) { PP = pp; }
261
262/// \brief Determine the set of code-completion contexts in which this
263/// declaration should be shown.
264static unsigned getDeclShowContexts(NamedDecl *ND,
265                                    const LangOptions &LangOpts,
266                                    bool &IsNestedNameSpecifier) {
267  IsNestedNameSpecifier = false;
268
269  if (isa<UsingShadowDecl>(ND))
270    ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
271  if (!ND)
272    return 0;
273
274  uint64_t Contexts = 0;
275  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
276      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
277    // Types can appear in these contexts.
278    if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
279      Contexts |= (1LL << CodeCompletionContext::CCC_TopLevel)
280               |  (1LL << CodeCompletionContext::CCC_ObjCIvarList)
281               |  (1LL << CodeCompletionContext::CCC_ClassStructUnion)
282               |  (1LL << CodeCompletionContext::CCC_Statement)
283               |  (1LL << CodeCompletionContext::CCC_Type)
284               |  (1LL << CodeCompletionContext::CCC_ParenthesizedExpression);
285
286    // In C++, types can appear in expressions contexts (for functional casts).
287    if (LangOpts.CPlusPlus)
288      Contexts |= (1LL << CodeCompletionContext::CCC_Expression);
289
290    // In Objective-C, message sends can send interfaces. In Objective-C++,
291    // all types are available due to functional casts.
292    if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
293      Contexts |= (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver);
294
295    // In Objective-C, you can only be a subclass of another Objective-C class
296    if (isa<ObjCInterfaceDecl>(ND))
297      Contexts |= (1LL << CodeCompletionContext::CCC_ObjCInterfaceName);
298
299    // Deal with tag names.
300    if (isa<EnumDecl>(ND)) {
301      Contexts |= (1LL << CodeCompletionContext::CCC_EnumTag);
302
303      // Part of the nested-name-specifier in C++0x.
304      if (LangOpts.CPlusPlus0x)
305        IsNestedNameSpecifier = true;
306    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
307      if (Record->isUnion())
308        Contexts |= (1LL << CodeCompletionContext::CCC_UnionTag);
309      else
310        Contexts |= (1LL << CodeCompletionContext::CCC_ClassOrStructTag);
311
312      if (LangOpts.CPlusPlus)
313        IsNestedNameSpecifier = true;
314    } else if (isa<ClassTemplateDecl>(ND))
315      IsNestedNameSpecifier = true;
316  } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
317    // Values can appear in these contexts.
318    Contexts = (1LL << CodeCompletionContext::CCC_Statement)
319             | (1LL << CodeCompletionContext::CCC_Expression)
320             | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression)
321             | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver);
322  } else if (isa<ObjCProtocolDecl>(ND)) {
323    Contexts = (1LL << CodeCompletionContext::CCC_ObjCProtocolName);
324  } else if (isa<ObjCCategoryDecl>(ND)) {
325    Contexts = (1LL << CodeCompletionContext::CCC_ObjCCategoryName);
326  } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
327    Contexts = (1LL << CodeCompletionContext::CCC_Namespace);
328
329    // Part of the nested-name-specifier.
330    IsNestedNameSpecifier = true;
331  }
332
333  return Contexts;
334}
335
336void ASTUnit::CacheCodeCompletionResults() {
337  if (!TheSema)
338    return;
339
340  SimpleTimer Timer(WantTiming);
341  Timer.setOutput("Cache global code completions for " + getMainFileName());
342
343  // Clear out the previous results.
344  ClearCachedCompletionResults();
345
346  // Gather the set of global code completions.
347  typedef CodeCompletionResult Result;
348  SmallVector<Result, 8> Results;
349  CachedCompletionAllocator = new GlobalCodeCompletionAllocator;
350  TheSema->GatherGlobalCodeCompletions(*CachedCompletionAllocator,
351                                       getCodeCompletionTUInfo(), Results);
352
353  // Translate global code completions into cached completions.
354  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
355
356  for (unsigned I = 0, N = Results.size(); I != N; ++I) {
357    switch (Results[I].Kind) {
358    case Result::RK_Declaration: {
359      bool IsNestedNameSpecifier = false;
360      CachedCodeCompletionResult CachedResult;
361      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema,
362                                                    *CachedCompletionAllocator,
363                                                    getCodeCompletionTUInfo(),
364                                          IncludeBriefCommentsInCodeCompletion);
365      CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
366                                                        Ctx->getLangOpts(),
367                                                        IsNestedNameSpecifier);
368      CachedResult.Priority = Results[I].Priority;
369      CachedResult.Kind = Results[I].CursorKind;
370      CachedResult.Availability = Results[I].Availability;
371
372      // Keep track of the type of this completion in an ASTContext-agnostic
373      // way.
374      QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
375      if (UsageType.isNull()) {
376        CachedResult.TypeClass = STC_Void;
377        CachedResult.Type = 0;
378      } else {
379        CanQualType CanUsageType
380          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
381        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
382
383        // Determine whether we have already seen this type. If so, we save
384        // ourselves the work of formatting the type string by using the
385        // temporary, CanQualType-based hash table to find the associated value.
386        unsigned &TypeValue = CompletionTypes[CanUsageType];
387        if (TypeValue == 0) {
388          TypeValue = CompletionTypes.size();
389          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
390            = TypeValue;
391        }
392
393        CachedResult.Type = TypeValue;
394      }
395
396      CachedCompletionResults.push_back(CachedResult);
397
398      /// Handle nested-name-specifiers in C++.
399      if (TheSema->Context.getLangOpts().CPlusPlus &&
400          IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
401        // The contexts in which a nested-name-specifier can appear in C++.
402        uint64_t NNSContexts
403          = (1LL << CodeCompletionContext::CCC_TopLevel)
404          | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
405          | (1LL << CodeCompletionContext::CCC_ClassStructUnion)
406          | (1LL << CodeCompletionContext::CCC_Statement)
407          | (1LL << CodeCompletionContext::CCC_Expression)
408          | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
409          | (1LL << CodeCompletionContext::CCC_EnumTag)
410          | (1LL << CodeCompletionContext::CCC_UnionTag)
411          | (1LL << CodeCompletionContext::CCC_ClassOrStructTag)
412          | (1LL << CodeCompletionContext::CCC_Type)
413          | (1LL << CodeCompletionContext::CCC_PotentiallyQualifiedName)
414          | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression);
415
416        if (isa<NamespaceDecl>(Results[I].Declaration) ||
417            isa<NamespaceAliasDecl>(Results[I].Declaration))
418          NNSContexts |= (1LL << CodeCompletionContext::CCC_Namespace);
419
420        if (unsigned RemainingContexts
421                                = NNSContexts & ~CachedResult.ShowInContexts) {
422          // If there any contexts where this completion can be a
423          // nested-name-specifier but isn't already an option, create a
424          // nested-name-specifier completion.
425          Results[I].StartsNestedNameSpecifier = true;
426          CachedResult.Completion
427            = Results[I].CreateCodeCompletionString(*TheSema,
428                                                    *CachedCompletionAllocator,
429                                                    getCodeCompletionTUInfo(),
430                                        IncludeBriefCommentsInCodeCompletion);
431          CachedResult.ShowInContexts = RemainingContexts;
432          CachedResult.Priority = CCP_NestedNameSpecifier;
433          CachedResult.TypeClass = STC_Void;
434          CachedResult.Type = 0;
435          CachedCompletionResults.push_back(CachedResult);
436        }
437      }
438      break;
439    }
440
441    case Result::RK_Keyword:
442    case Result::RK_Pattern:
443      // Ignore keywords and patterns; we don't care, since they are so
444      // easily regenerated.
445      break;
446
447    case Result::RK_Macro: {
448      CachedCodeCompletionResult CachedResult;
449      CachedResult.Completion
450        = Results[I].CreateCodeCompletionString(*TheSema,
451                                                *CachedCompletionAllocator,
452                                                getCodeCompletionTUInfo(),
453                                          IncludeBriefCommentsInCodeCompletion);
454      CachedResult.ShowInContexts
455        = (1LL << CodeCompletionContext::CCC_TopLevel)
456        | (1LL << CodeCompletionContext::CCC_ObjCInterface)
457        | (1LL << CodeCompletionContext::CCC_ObjCImplementation)
458        | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
459        | (1LL << CodeCompletionContext::CCC_ClassStructUnion)
460        | (1LL << CodeCompletionContext::CCC_Statement)
461        | (1LL << CodeCompletionContext::CCC_Expression)
462        | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
463        | (1LL << CodeCompletionContext::CCC_MacroNameUse)
464        | (1LL << CodeCompletionContext::CCC_PreprocessorExpression)
465        | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression)
466        | (1LL << CodeCompletionContext::CCC_OtherWithMacros);
467
468      CachedResult.Priority = Results[I].Priority;
469      CachedResult.Kind = Results[I].CursorKind;
470      CachedResult.Availability = Results[I].Availability;
471      CachedResult.TypeClass = STC_Void;
472      CachedResult.Type = 0;
473      CachedCompletionResults.push_back(CachedResult);
474      break;
475    }
476    }
477  }
478
479  // Save the current top-level hash value.
480  CompletionCacheTopLevelHashValue = CurrentTopLevelHashValue;
481}
482
483void ASTUnit::ClearCachedCompletionResults() {
484  CachedCompletionResults.clear();
485  CachedCompletionTypes.clear();
486  CachedCompletionAllocator = 0;
487}
488
489namespace {
490
491/// \brief Gathers information from ASTReader that will be used to initialize
492/// a Preprocessor.
493class ASTInfoCollector : public ASTReaderListener {
494  Preprocessor &PP;
495  ASTContext &Context;
496  LangOptions &LangOpt;
497  HeaderSearch &HSI;
498  IntrusiveRefCntPtr<TargetInfo> &Target;
499  std::string &Predefines;
500  unsigned &Counter;
501
502  unsigned NumHeaderInfos;
503
504  bool InitializedLanguage;
505public:
506  ASTInfoCollector(Preprocessor &PP, ASTContext &Context, LangOptions &LangOpt,
507                   HeaderSearch &HSI,
508                   IntrusiveRefCntPtr<TargetInfo> &Target,
509                   std::string &Predefines,
510                   unsigned &Counter)
511    : PP(PP), Context(Context), LangOpt(LangOpt), HSI(HSI), Target(Target),
512      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0),
513      InitializedLanguage(false) {}
514
515  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
516    if (InitializedLanguage)
517      return false;
518
519    LangOpt = LangOpts;
520
521    // Initialize the preprocessor.
522    PP.Initialize(*Target);
523
524    // Initialize the ASTContext
525    Context.InitBuiltinTypes(*Target);
526
527    InitializedLanguage = true;
528
529    applyLangOptsToTarget();
530    return false;
531  }
532
533  virtual bool ReadTargetTriple(StringRef Triple) {
534    // If we've already initialized the target, don't do it again.
535    if (Target)
536      return false;
537
538    // FIXME: This is broken, we should store the TargetOptions in the AST file.
539    TargetOptions TargetOpts;
540    TargetOpts.ABI = "";
541    TargetOpts.CXXABI = "";
542    TargetOpts.CPU = "";
543    TargetOpts.Features.clear();
544    TargetOpts.Triple = Triple;
545    Target = TargetInfo::CreateTargetInfo(PP.getDiagnostics(), TargetOpts);
546
547    applyLangOptsToTarget();
548    return false;
549  }
550
551  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
552                                    StringRef OriginalFileName,
553                                    std::string &SuggestedPredefines,
554                                    FileManager &FileMgr) {
555    Predefines = Buffers[0].Data;
556    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
557      Predefines += Buffers[I].Data;
558    }
559    return false;
560  }
561
562  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
563    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
564  }
565
566  virtual void ReadCounter(unsigned Value) {
567    Counter = Value;
568  }
569
570private:
571  void applyLangOptsToTarget() {
572    if (Target && InitializedLanguage) {
573      // Inform the target of the language options.
574      //
575      // FIXME: We shouldn't need to do this, the target should be immutable once
576      // created. This complexity should be lifted elsewhere.
577      Target->setForcedLangOptions(LangOpt);
578    }
579  }
580};
581
582class StoredDiagnosticConsumer : public DiagnosticConsumer {
583  SmallVectorImpl<StoredDiagnostic> &StoredDiags;
584
585public:
586  explicit StoredDiagnosticConsumer(
587                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
588    : StoredDiags(StoredDiags) { }
589
590  virtual void HandleDiagnostic(DiagnosticsEngine::Level Level,
591                                const Diagnostic &Info);
592
593  DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
594    // Just drop any diagnostics that come from cloned consumers; they'll
595    // have different source managers anyway.
596    // FIXME: We'd like to be able to capture these somehow, even if it's just
597    // file/line/column, because they could occur when parsing module maps or
598    // building modules on-demand.
599    return new IgnoringDiagConsumer();
600  }
601};
602
603/// \brief RAII object that optionally captures diagnostics, if
604/// there is no diagnostic client to capture them already.
605class CaptureDroppedDiagnostics {
606  DiagnosticsEngine &Diags;
607  StoredDiagnosticConsumer Client;
608  DiagnosticConsumer *PreviousClient;
609
610public:
611  CaptureDroppedDiagnostics(bool RequestCapture, DiagnosticsEngine &Diags,
612                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
613    : Diags(Diags), Client(StoredDiags), PreviousClient(0)
614  {
615    if (RequestCapture || Diags.getClient() == 0) {
616      PreviousClient = Diags.takeClient();
617      Diags.setClient(&Client);
618    }
619  }
620
621  ~CaptureDroppedDiagnostics() {
622    if (Diags.getClient() == &Client) {
623      Diags.takeClient();
624      Diags.setClient(PreviousClient);
625    }
626  }
627};
628
629} // anonymous namespace
630
631void StoredDiagnosticConsumer::HandleDiagnostic(DiagnosticsEngine::Level Level,
632                                              const Diagnostic &Info) {
633  // Default implementation (Warnings/errors count).
634  DiagnosticConsumer::HandleDiagnostic(Level, Info);
635
636  StoredDiags.push_back(StoredDiagnostic(Level, Info));
637}
638
639const std::string &ASTUnit::getOriginalSourceFileName() {
640  return OriginalSourceFile;
641}
642
643llvm::MemoryBuffer *ASTUnit::getBufferForFile(StringRef Filename,
644                                              std::string *ErrorStr) {
645  assert(FileMgr);
646  return FileMgr->getBufferForFile(Filename, ErrorStr);
647}
648
649/// \brief Configure the diagnostics object for use with ASTUnit.
650void ASTUnit::ConfigureDiags(IntrusiveRefCntPtr<DiagnosticsEngine> &Diags,
651                             const char **ArgBegin, const char **ArgEnd,
652                             ASTUnit &AST, bool CaptureDiagnostics) {
653  if (!Diags.getPtr()) {
654    // No diagnostics engine was provided, so create our own diagnostics object
655    // with the default options.
656    DiagnosticOptions DiagOpts;
657    DiagnosticConsumer *Client = 0;
658    if (CaptureDiagnostics)
659      Client = new StoredDiagnosticConsumer(AST.StoredDiagnostics);
660    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd-ArgBegin,
661                                                ArgBegin, Client,
662                                                /*ShouldOwnClient=*/true,
663                                                /*ShouldCloneClient=*/false);
664  } else if (CaptureDiagnostics) {
665    Diags->setClient(new StoredDiagnosticConsumer(AST.StoredDiagnostics));
666  }
667}
668
669ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
670                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
671                                  const FileSystemOptions &FileSystemOpts,
672                                  bool OnlyLocalDecls,
673                                  RemappedFile *RemappedFiles,
674                                  unsigned NumRemappedFiles,
675                                  bool CaptureDiagnostics,
676                                  bool AllowPCHWithCompilerErrors,
677                                  bool UserFilesAreVolatile) {
678  OwningPtr<ASTUnit> AST(new ASTUnit(true));
679
680  // Recover resources if we crash before exiting this method.
681  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
682    ASTUnitCleanup(AST.get());
683  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
684    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
685    DiagCleanup(Diags.getPtr());
686
687  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
688
689  AST->OnlyLocalDecls = OnlyLocalDecls;
690  AST->CaptureDiagnostics = CaptureDiagnostics;
691  AST->Diagnostics = Diags;
692  AST->FileMgr = new FileManager(FileSystemOpts);
693  AST->UserFilesAreVolatile = UserFilesAreVolatile;
694  AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
695                                     AST->getFileManager(),
696                                     UserFilesAreVolatile);
697  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager(),
698                                         AST->getDiagnostics(),
699                                         AST->ASTFileLangOpts,
700                                         /*Target=*/0));
701
702  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
703    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
704    if (const llvm::MemoryBuffer *
705          memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
706      // Create the file entry for the file that we're mapping from.
707      const FileEntry *FromFile
708        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
709                                               memBuf->getBufferSize(),
710                                               0);
711      if (!FromFile) {
712        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
713          << RemappedFiles[I].first;
714        delete memBuf;
715        continue;
716      }
717
718      // Override the contents of the "from" file with the contents of
719      // the "to" file.
720      AST->getSourceManager().overrideFileContents(FromFile, memBuf);
721
722    } else {
723      const char *fname = fileOrBuf.get<const char *>();
724      const FileEntry *ToFile = AST->FileMgr->getFile(fname);
725      if (!ToFile) {
726        AST->getDiagnostics().Report(diag::err_fe_remap_missing_to_file)
727        << RemappedFiles[I].first << fname;
728        continue;
729      }
730
731      // Create the file entry for the file that we're mapping from.
732      const FileEntry *FromFile
733        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
734                                               ToFile->getSize(),
735                                               0);
736      if (!FromFile) {
737        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
738          << RemappedFiles[I].first;
739        delete memBuf;
740        continue;
741      }
742
743      // Override the contents of the "from" file with the contents of
744      // the "to" file.
745      AST->getSourceManager().overrideFileContents(FromFile, ToFile);
746    }
747  }
748
749  // Gather Info for preprocessor construction later on.
750
751  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
752  std::string Predefines;
753  unsigned Counter;
754
755  OwningPtr<ASTReader> Reader;
756
757  AST->PP = new Preprocessor(AST->getDiagnostics(), AST->ASTFileLangOpts,
758                             /*Target=*/0, AST->getSourceManager(), HeaderInfo,
759                             *AST,
760                             /*IILookup=*/0,
761                             /*OwnsHeaderSearch=*/false,
762                             /*DelayInitialization=*/true);
763  Preprocessor &PP = *AST->PP;
764
765  AST->Ctx = new ASTContext(AST->ASTFileLangOpts,
766                            AST->getSourceManager(),
767                            /*Target=*/0,
768                            PP.getIdentifierTable(),
769                            PP.getSelectorTable(),
770                            PP.getBuiltinInfo(),
771                            /* size_reserve = */0,
772                            /*DelayInitialization=*/true);
773  ASTContext &Context = *AST->Ctx;
774
775  bool disableValid = false;
776  if (::getenv("LIBCLANG_DISABLE_PCH_VALIDATION"))
777    disableValid = true;
778  Reader.reset(new ASTReader(PP, Context,
779                             /*isysroot=*/"",
780                             /*DisableValidation=*/disableValid,
781                             /*DisableStatCache=*/false,
782                             AllowPCHWithCompilerErrors));
783
784  // Recover resources if we crash before exiting this method.
785  llvm::CrashRecoveryContextCleanupRegistrar<ASTReader>
786    ReaderCleanup(Reader.get());
787
788  Reader->setListener(new ASTInfoCollector(*AST->PP, Context,
789                                           AST->ASTFileLangOpts, HeaderInfo,
790                                           AST->Target, Predefines, Counter));
791
792  switch (Reader->ReadAST(Filename, serialization::MK_MainFile)) {
793  case ASTReader::Success:
794    break;
795
796  case ASTReader::Failure:
797  case ASTReader::IgnorePCH:
798    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
799    return NULL;
800  }
801
802  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
803
804  PP.setPredefines(Reader->getSuggestedPredefines());
805  PP.setCounterValue(Counter);
806
807  // Attach the AST reader to the AST context as an external AST
808  // source, so that declarations will be deserialized from the
809  // AST file as needed.
810  ASTReader *ReaderPtr = Reader.get();
811  OwningPtr<ExternalASTSource> Source(Reader.take());
812
813  // Unregister the cleanup for ASTReader.  It will get cleaned up
814  // by the ASTUnit cleanup.
815  ReaderCleanup.unregister();
816
817  Context.setExternalSource(Source);
818
819  // Create an AST consumer, even though it isn't used.
820  AST->Consumer.reset(new ASTConsumer);
821
822  // Create a semantic analysis object and tell the AST reader about it.
823  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
824  AST->TheSema->Initialize();
825  ReaderPtr->InitializeSema(*AST->TheSema);
826  AST->Reader = ReaderPtr;
827
828  return AST.take();
829}
830
831namespace {
832
833/// \brief Preprocessor callback class that updates a hash value with the names
834/// of all macros that have been defined by the translation unit.
835class MacroDefinitionTrackerPPCallbacks : public PPCallbacks {
836  unsigned &Hash;
837
838public:
839  explicit MacroDefinitionTrackerPPCallbacks(unsigned &Hash) : Hash(Hash) { }
840
841  virtual void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI) {
842    Hash = llvm::HashString(MacroNameTok.getIdentifierInfo()->getName(), Hash);
843  }
844};
845
846/// \brief Add the given declaration to the hash of all top-level entities.
847void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
848  if (!D)
849    return;
850
851  DeclContext *DC = D->getDeclContext();
852  if (!DC)
853    return;
854
855  if (!(DC->isTranslationUnit() || DC->getLookupParent()->isTranslationUnit()))
856    return;
857
858  if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
859    if (ND->getIdentifier())
860      Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
861    else if (DeclarationName Name = ND->getDeclName()) {
862      std::string NameStr = Name.getAsString();
863      Hash = llvm::HashString(NameStr, Hash);
864    }
865    return;
866  }
867}
868
869class TopLevelDeclTrackerConsumer : public ASTConsumer {
870  ASTUnit &Unit;
871  unsigned &Hash;
872
873public:
874  TopLevelDeclTrackerConsumer(ASTUnit &_Unit, unsigned &Hash)
875    : Unit(_Unit), Hash(Hash) {
876    Hash = 0;
877  }
878
879  void handleTopLevelDecl(Decl *D) {
880    if (!D)
881      return;
882
883    // FIXME: Currently ObjC method declarations are incorrectly being
884    // reported as top-level declarations, even though their DeclContext
885    // is the containing ObjC @interface/@implementation.  This is a
886    // fundamental problem in the parser right now.
887    if (isa<ObjCMethodDecl>(D))
888      return;
889
890    AddTopLevelDeclarationToHash(D, Hash);
891    Unit.addTopLevelDecl(D);
892
893    handleFileLevelDecl(D);
894  }
895
896  void handleFileLevelDecl(Decl *D) {
897    Unit.addFileLevelDecl(D);
898    if (NamespaceDecl *NSD = dyn_cast<NamespaceDecl>(D)) {
899      for (NamespaceDecl::decl_iterator
900             I = NSD->decls_begin(), E = NSD->decls_end(); I != E; ++I)
901        handleFileLevelDecl(*I);
902    }
903  }
904
905  bool HandleTopLevelDecl(DeclGroupRef D) {
906    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it)
907      handleTopLevelDecl(*it);
908    return true;
909  }
910
911  // We're not interested in "interesting" decls.
912  void HandleInterestingDecl(DeclGroupRef) {}
913
914  void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) {
915    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it)
916      handleTopLevelDecl(*it);
917  }
918};
919
920class TopLevelDeclTrackerAction : public ASTFrontendAction {
921public:
922  ASTUnit &Unit;
923
924  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
925                                         StringRef InFile) {
926    CI.getPreprocessor().addPPCallbacks(
927     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
928    return new TopLevelDeclTrackerConsumer(Unit,
929                                           Unit.getCurrentTopLevelHashValue());
930  }
931
932public:
933  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
934
935  virtual bool hasCodeCompletionSupport() const { return false; }
936  virtual TranslationUnitKind getTranslationUnitKind()  {
937    return Unit.getTranslationUnitKind();
938  }
939};
940
941class PrecompilePreambleConsumer : public PCHGenerator {
942  ASTUnit &Unit;
943  unsigned &Hash;
944  std::vector<Decl *> TopLevelDecls;
945
946public:
947  PrecompilePreambleConsumer(ASTUnit &Unit, const Preprocessor &PP,
948                             StringRef isysroot, raw_ostream *Out)
949    : PCHGenerator(PP, "", 0, isysroot, Out), Unit(Unit),
950      Hash(Unit.getCurrentTopLevelHashValue()) {
951    Hash = 0;
952  }
953
954  virtual bool HandleTopLevelDecl(DeclGroupRef D) {
955    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
956      Decl *D = *it;
957      // FIXME: Currently ObjC method declarations are incorrectly being
958      // reported as top-level declarations, even though their DeclContext
959      // is the containing ObjC @interface/@implementation.  This is a
960      // fundamental problem in the parser right now.
961      if (isa<ObjCMethodDecl>(D))
962        continue;
963      AddTopLevelDeclarationToHash(D, Hash);
964      TopLevelDecls.push_back(D);
965    }
966    return true;
967  }
968
969  virtual void HandleTranslationUnit(ASTContext &Ctx) {
970    PCHGenerator::HandleTranslationUnit(Ctx);
971    if (!Unit.getDiagnostics().hasErrorOccurred()) {
972      // Translate the top-level declarations we captured during
973      // parsing into declaration IDs in the precompiled
974      // preamble. This will allow us to deserialize those top-level
975      // declarations when requested.
976      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
977        Unit.addTopLevelDeclFromPreamble(
978                                      getWriter().getDeclID(TopLevelDecls[I]));
979    }
980  }
981};
982
983class PrecompilePreambleAction : public ASTFrontendAction {
984  ASTUnit &Unit;
985
986public:
987  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
988
989  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
990                                         StringRef InFile) {
991    std::string Sysroot;
992    std::string OutputFile;
993    raw_ostream *OS = 0;
994    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
995                                                       OutputFile,
996                                                       OS))
997      return 0;
998
999    if (!CI.getFrontendOpts().RelocatablePCH)
1000      Sysroot.clear();
1001
1002    CI.getPreprocessor().addPPCallbacks(
1003     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
1004    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Sysroot,
1005                                          OS);
1006  }
1007
1008  virtual bool hasCodeCompletionSupport() const { return false; }
1009  virtual bool hasASTFileSupport() const { return false; }
1010  virtual TranslationUnitKind getTranslationUnitKind() { return TU_Prefix; }
1011};
1012
1013}
1014
1015static void checkAndRemoveNonDriverDiags(SmallVectorImpl<StoredDiagnostic> &
1016                                                            StoredDiagnostics) {
1017  // Get rid of stored diagnostics except the ones from the driver which do not
1018  // have a source location.
1019  for (unsigned I = 0; I < StoredDiagnostics.size(); ++I) {
1020    if (StoredDiagnostics[I].getLocation().isValid()) {
1021      StoredDiagnostics.erase(StoredDiagnostics.begin()+I);
1022      --I;
1023    }
1024  }
1025}
1026
1027static void checkAndSanitizeDiags(SmallVectorImpl<StoredDiagnostic> &
1028                                                              StoredDiagnostics,
1029                                  SourceManager &SM) {
1030  // The stored diagnostic has the old source manager in it; update
1031  // the locations to refer into the new source manager. Since we've
1032  // been careful to make sure that the source manager's state
1033  // before and after are identical, so that we can reuse the source
1034  // location itself.
1035  for (unsigned I = 0, N = StoredDiagnostics.size(); I < N; ++I) {
1036    if (StoredDiagnostics[I].getLocation().isValid()) {
1037      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SM);
1038      StoredDiagnostics[I].setLocation(Loc);
1039    }
1040  }
1041}
1042
1043/// Parse the source file into a translation unit using the given compiler
1044/// invocation, replacing the current translation unit.
1045///
1046/// \returns True if a failure occurred that causes the ASTUnit not to
1047/// contain any translation-unit information, false otherwise.
1048bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
1049  delete SavedMainFileBuffer;
1050  SavedMainFileBuffer = 0;
1051
1052  if (!Invocation) {
1053    delete OverrideMainBuffer;
1054    return true;
1055  }
1056
1057  // Create the compiler instance to use for building the AST.
1058  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1059
1060  // Recover resources if we crash before exiting this method.
1061  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1062    CICleanup(Clang.get());
1063
1064  IntrusiveRefCntPtr<CompilerInvocation>
1065    CCInvocation(new CompilerInvocation(*Invocation));
1066
1067  Clang->setInvocation(CCInvocation.getPtr());
1068  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
1069
1070  // Set up diagnostics, capturing any diagnostics that would
1071  // otherwise be dropped.
1072  Clang->setDiagnostics(&getDiagnostics());
1073
1074  // Create the target instance.
1075  Clang->getTargetOpts().Features = TargetFeatures;
1076  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1077                   Clang->getTargetOpts()));
1078  if (!Clang->hasTarget()) {
1079    delete OverrideMainBuffer;
1080    return true;
1081  }
1082
1083  // Inform the target of the language options.
1084  //
1085  // FIXME: We shouldn't need to do this, the target should be immutable once
1086  // created. This complexity should be lifted elsewhere.
1087  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1088
1089  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1090         "Invocation must have exactly one source file!");
1091  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
1092         "FIXME: AST inputs not yet supported here!");
1093  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
1094         "IR inputs not support here!");
1095
1096  // Configure the various subsystems.
1097  // FIXME: Should we retain the previous file manager?
1098  LangOpts = &Clang->getLangOpts();
1099  FileSystemOpts = Clang->getFileSystemOpts();
1100  FileMgr = new FileManager(FileSystemOpts);
1101  SourceMgr = new SourceManager(getDiagnostics(), *FileMgr,
1102                                UserFilesAreVolatile);
1103  TheSema.reset();
1104  Ctx = 0;
1105  PP = 0;
1106  Reader = 0;
1107
1108  // Clear out old caches and data.
1109  TopLevelDecls.clear();
1110  clearFileLevelDecls();
1111  CleanTemporaryFiles();
1112
1113  if (!OverrideMainBuffer) {
1114    checkAndRemoveNonDriverDiags(StoredDiagnostics);
1115    TopLevelDeclsInPreamble.clear();
1116  }
1117
1118  // Create a file manager object to provide access to and cache the filesystem.
1119  Clang->setFileManager(&getFileManager());
1120
1121  // Create the source manager.
1122  Clang->setSourceManager(&getSourceManager());
1123
1124  // If the main file has been overridden due to the use of a preamble,
1125  // make that override happen and introduce the preamble.
1126  PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
1127  if (OverrideMainBuffer) {
1128    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
1129    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1130    PreprocessorOpts.PrecompiledPreambleBytes.second
1131                                                    = PreambleEndsAtStartOfLine;
1132    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
1133    PreprocessorOpts.DisablePCHValidation = true;
1134
1135    // The stored diagnostic has the old source manager in it; update
1136    // the locations to refer into the new source manager. Since we've
1137    // been careful to make sure that the source manager's state
1138    // before and after are identical, so that we can reuse the source
1139    // location itself.
1140    checkAndSanitizeDiags(StoredDiagnostics, getSourceManager());
1141
1142    // Keep track of the override buffer;
1143    SavedMainFileBuffer = OverrideMainBuffer;
1144  }
1145
1146  OwningPtr<TopLevelDeclTrackerAction> Act(
1147    new TopLevelDeclTrackerAction(*this));
1148
1149  // Recover resources if we crash before exiting this method.
1150  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1151    ActCleanup(Act.get());
1152
1153  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))
1154    goto error;
1155
1156  if (OverrideMainBuffer) {
1157    std::string ModName = getPreambleFile(this);
1158    TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
1159                               getSourceManager(), PreambleDiagnostics,
1160                               StoredDiagnostics);
1161  }
1162
1163  if (!Act->Execute())
1164    goto error;
1165
1166  transferASTDataFromCompilerInstance(*Clang);
1167
1168  Act->EndSourceFile();
1169
1170  FailedParseDiagnostics.clear();
1171
1172  return false;
1173
1174error:
1175  // Remove the overridden buffer we used for the preamble.
1176  if (OverrideMainBuffer) {
1177    delete OverrideMainBuffer;
1178    SavedMainFileBuffer = 0;
1179  }
1180
1181  // Keep the ownership of the data in the ASTUnit because the client may
1182  // want to see the diagnostics.
1183  transferASTDataFromCompilerInstance(*Clang);
1184  FailedParseDiagnostics.swap(StoredDiagnostics);
1185  StoredDiagnostics.clear();
1186  NumStoredDiagnosticsFromDriver = 0;
1187  return true;
1188}
1189
1190/// \brief Simple function to retrieve a path for a preamble precompiled header.
1191static std::string GetPreamblePCHPath() {
1192  // FIXME: This is lame; sys::Path should provide this function (in particular,
1193  // it should know how to find the temporary files dir).
1194  // FIXME: This is really lame. I copied this code from the Driver!
1195  // FIXME: This is a hack so that we can override the preamble file during
1196  // crash-recovery testing, which is the only case where the preamble files
1197  // are not necessarily cleaned up.
1198  const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
1199  if (TmpFile)
1200    return TmpFile;
1201
1202  std::string Error;
1203  const char *TmpDir = ::getenv("TMPDIR");
1204  if (!TmpDir)
1205    TmpDir = ::getenv("TEMP");
1206  if (!TmpDir)
1207    TmpDir = ::getenv("TMP");
1208#ifdef LLVM_ON_WIN32
1209  if (!TmpDir)
1210    TmpDir = ::getenv("USERPROFILE");
1211#endif
1212  if (!TmpDir)
1213    TmpDir = "/tmp";
1214  llvm::sys::Path P(TmpDir);
1215  P.createDirectoryOnDisk(true);
1216  P.appendComponent("preamble");
1217  P.appendSuffix("pch");
1218  if (P.makeUnique(/*reuse_current=*/false, /*ErrMsg*/0))
1219    return std::string();
1220
1221  return P.str();
1222}
1223
1224/// \brief Compute the preamble for the main file, providing the source buffer
1225/// that corresponds to the main file along with a pair (bytes, start-of-line)
1226/// that describes the preamble.
1227std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
1228ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
1229                         unsigned MaxLines, bool &CreatedBuffer) {
1230  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
1231  PreprocessorOptions &PreprocessorOpts = Invocation.getPreprocessorOpts();
1232  CreatedBuffer = false;
1233
1234  // Try to determine if the main file has been remapped, either from the
1235  // command line (to another file) or directly through the compiler invocation
1236  // (to a memory buffer).
1237  llvm::MemoryBuffer *Buffer = 0;
1238  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].File);
1239  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
1240    // Check whether there is a file-file remapping of the main file
1241    for (PreprocessorOptions::remapped_file_iterator
1242          M = PreprocessorOpts.remapped_file_begin(),
1243          E = PreprocessorOpts.remapped_file_end();
1244         M != E;
1245         ++M) {
1246      llvm::sys::PathWithStatus MPath(M->first);
1247      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1248        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1249          // We found a remapping. Try to load the resulting, remapped source.
1250          if (CreatedBuffer) {
1251            delete Buffer;
1252            CreatedBuffer = false;
1253          }
1254
1255          Buffer = getBufferForFile(M->second);
1256          if (!Buffer)
1257            return std::make_pair((llvm::MemoryBuffer*)0,
1258                                  std::make_pair(0, true));
1259          CreatedBuffer = true;
1260        }
1261      }
1262    }
1263
1264    // Check whether there is a file-buffer remapping. It supercedes the
1265    // file-file remapping.
1266    for (PreprocessorOptions::remapped_file_buffer_iterator
1267           M = PreprocessorOpts.remapped_file_buffer_begin(),
1268           E = PreprocessorOpts.remapped_file_buffer_end();
1269         M != E;
1270         ++M) {
1271      llvm::sys::PathWithStatus MPath(M->first);
1272      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1273        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1274          // We found a remapping.
1275          if (CreatedBuffer) {
1276            delete Buffer;
1277            CreatedBuffer = false;
1278          }
1279
1280          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
1281        }
1282      }
1283    }
1284  }
1285
1286  // If the main source file was not remapped, load it now.
1287  if (!Buffer) {
1288    Buffer = getBufferForFile(FrontendOpts.Inputs[0].File);
1289    if (!Buffer)
1290      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
1291
1292    CreatedBuffer = true;
1293  }
1294
1295  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer,
1296                                                       *Invocation.getLangOpts(),
1297                                                       MaxLines));
1298}
1299
1300static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
1301                                                      unsigned NewSize,
1302                                                      StringRef NewName) {
1303  llvm::MemoryBuffer *Result
1304    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
1305  memcpy(const_cast<char*>(Result->getBufferStart()),
1306         Old->getBufferStart(), Old->getBufferSize());
1307  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
1308         ' ', NewSize - Old->getBufferSize() - 1);
1309  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
1310
1311  return Result;
1312}
1313
1314/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
1315/// the source file.
1316///
1317/// This routine will compute the preamble of the main source file. If a
1318/// non-trivial preamble is found, it will precompile that preamble into a
1319/// precompiled header so that the precompiled preamble can be used to reduce
1320/// reparsing time. If a precompiled preamble has already been constructed,
1321/// this routine will determine if it is still valid and, if so, avoid
1322/// rebuilding the precompiled preamble.
1323///
1324/// \param AllowRebuild When true (the default), this routine is
1325/// allowed to rebuild the precompiled preamble if it is found to be
1326/// out-of-date.
1327///
1328/// \param MaxLines When non-zero, the maximum number of lines that
1329/// can occur within the preamble.
1330///
1331/// \returns If the precompiled preamble can be used, returns a newly-allocated
1332/// buffer that should be used in place of the main file when doing so.
1333/// Otherwise, returns a NULL pointer.
1334llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
1335                              const CompilerInvocation &PreambleInvocationIn,
1336                                                           bool AllowRebuild,
1337                                                           unsigned MaxLines) {
1338
1339  IntrusiveRefCntPtr<CompilerInvocation>
1340    PreambleInvocation(new CompilerInvocation(PreambleInvocationIn));
1341  FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();
1342  PreprocessorOptions &PreprocessorOpts
1343    = PreambleInvocation->getPreprocessorOpts();
1344
1345  bool CreatedPreambleBuffer = false;
1346  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
1347    = ComputePreamble(*PreambleInvocation, MaxLines, CreatedPreambleBuffer);
1348
1349  // If ComputePreamble() Take ownership of the preamble buffer.
1350  OwningPtr<llvm::MemoryBuffer> OwnedPreambleBuffer;
1351  if (CreatedPreambleBuffer)
1352    OwnedPreambleBuffer.reset(NewPreamble.first);
1353
1354  if (!NewPreamble.second.first) {
1355    // We couldn't find a preamble in the main source. Clear out the current
1356    // preamble, if we have one. It's obviously no good any more.
1357    Preamble.clear();
1358    erasePreambleFile(this);
1359
1360    // The next time we actually see a preamble, precompile it.
1361    PreambleRebuildCounter = 1;
1362    return 0;
1363  }
1364
1365  if (!Preamble.empty()) {
1366    // We've previously computed a preamble. Check whether we have the same
1367    // preamble now that we did before, and that there's enough space in
1368    // the main-file buffer within the precompiled preamble to fit the
1369    // new main file.
1370    if (Preamble.size() == NewPreamble.second.first &&
1371        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
1372        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
1373        memcmp(Preamble.getBufferStart(), NewPreamble.first->getBufferStart(),
1374               NewPreamble.second.first) == 0) {
1375      // The preamble has not changed. We may be able to re-use the precompiled
1376      // preamble.
1377
1378      // Check that none of the files used by the preamble have changed.
1379      bool AnyFileChanged = false;
1380
1381      // First, make a record of those files that have been overridden via
1382      // remapping or unsaved_files.
1383      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
1384      for (PreprocessorOptions::remapped_file_iterator
1385                R = PreprocessorOpts.remapped_file_begin(),
1386             REnd = PreprocessorOpts.remapped_file_end();
1387           !AnyFileChanged && R != REnd;
1388           ++R) {
1389        struct stat StatBuf;
1390        if (FileMgr->getNoncachedStatValue(R->second, StatBuf)) {
1391          // If we can't stat the file we're remapping to, assume that something
1392          // horrible happened.
1393          AnyFileChanged = true;
1394          break;
1395        }
1396
1397        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
1398                                                   StatBuf.st_mtime);
1399      }
1400      for (PreprocessorOptions::remapped_file_buffer_iterator
1401                R = PreprocessorOpts.remapped_file_buffer_begin(),
1402             REnd = PreprocessorOpts.remapped_file_buffer_end();
1403           !AnyFileChanged && R != REnd;
1404           ++R) {
1405        // FIXME: Should we actually compare the contents of file->buffer
1406        // remappings?
1407        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
1408                                                   0);
1409      }
1410
1411      // Check whether anything has changed.
1412      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
1413             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1414           !AnyFileChanged && F != FEnd;
1415           ++F) {
1416        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1417          = OverriddenFiles.find(F->first());
1418        if (Overridden != OverriddenFiles.end()) {
1419          // This file was remapped; check whether the newly-mapped file
1420          // matches up with the previous mapping.
1421          if (Overridden->second != F->second)
1422            AnyFileChanged = true;
1423          continue;
1424        }
1425
1426        // The file was not remapped; check whether it has changed on disk.
1427        struct stat StatBuf;
1428        if (FileMgr->getNoncachedStatValue(F->first(), StatBuf)) {
1429          // If we can't stat the file, assume that something horrible happened.
1430          AnyFileChanged = true;
1431        } else if (StatBuf.st_size != F->second.first ||
1432                   StatBuf.st_mtime != F->second.second)
1433          AnyFileChanged = true;
1434      }
1435
1436      if (!AnyFileChanged) {
1437        // Okay! We can re-use the precompiled preamble.
1438
1439        // Set the state of the diagnostic object to mimic its state
1440        // after parsing the preamble.
1441        getDiagnostics().Reset();
1442        ProcessWarningOptions(getDiagnostics(),
1443                              PreambleInvocation->getDiagnosticOpts());
1444        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1445
1446        // Create a version of the main file buffer that is padded to
1447        // buffer size we reserved when creating the preamble.
1448        return CreatePaddedMainFileBuffer(NewPreamble.first,
1449                                          PreambleReservedSize,
1450                                          FrontendOpts.Inputs[0].File);
1451      }
1452    }
1453
1454    // If we aren't allowed to rebuild the precompiled preamble, just
1455    // return now.
1456    if (!AllowRebuild)
1457      return 0;
1458
1459    // We can't reuse the previously-computed preamble. Build a new one.
1460    Preamble.clear();
1461    PreambleDiagnostics.clear();
1462    erasePreambleFile(this);
1463    PreambleRebuildCounter = 1;
1464  } else if (!AllowRebuild) {
1465    // We aren't allowed to rebuild the precompiled preamble; just
1466    // return now.
1467    return 0;
1468  }
1469
1470  // If the preamble rebuild counter > 1, it's because we previously
1471  // failed to build a preamble and we're not yet ready to try
1472  // again. Decrement the counter and return a failure.
1473  if (PreambleRebuildCounter > 1) {
1474    --PreambleRebuildCounter;
1475    return 0;
1476  }
1477
1478  // Create a temporary file for the precompiled preamble. In rare
1479  // circumstances, this can fail.
1480  std::string PreamblePCHPath = GetPreamblePCHPath();
1481  if (PreamblePCHPath.empty()) {
1482    // Try again next time.
1483    PreambleRebuildCounter = 1;
1484    return 0;
1485  }
1486
1487  // We did not previously compute a preamble, or it can't be reused anyway.
1488  SimpleTimer PreambleTimer(WantTiming);
1489  PreambleTimer.setOutput("Precompiling preamble");
1490
1491  // Create a new buffer that stores the preamble. The buffer also contains
1492  // extra space for the original contents of the file (which will be present
1493  // when we actually parse the file) along with more room in case the file
1494  // grows.
1495  PreambleReservedSize = NewPreamble.first->getBufferSize();
1496  if (PreambleReservedSize < 4096)
1497    PreambleReservedSize = 8191;
1498  else
1499    PreambleReservedSize *= 2;
1500
1501  // Save the preamble text for later; we'll need to compare against it for
1502  // subsequent reparses.
1503  StringRef MainFilename = PreambleInvocation->getFrontendOpts().Inputs[0].File;
1504  Preamble.assign(FileMgr->getFile(MainFilename),
1505                  NewPreamble.first->getBufferStart(),
1506                  NewPreamble.first->getBufferStart()
1507                                                  + NewPreamble.second.first);
1508  PreambleEndsAtStartOfLine = NewPreamble.second.second;
1509
1510  delete PreambleBuffer;
1511  PreambleBuffer
1512    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1513                                                FrontendOpts.Inputs[0].File);
1514  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1515         NewPreamble.first->getBufferStart(), Preamble.size());
1516  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1517         ' ', PreambleReservedSize - Preamble.size() - 1);
1518  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1519
1520  // Remap the main source file to the preamble buffer.
1521  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].File);
1522  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1523
1524  // Tell the compiler invocation to generate a temporary precompiled header.
1525  FrontendOpts.ProgramAction = frontend::GeneratePCH;
1526  // FIXME: Generate the precompiled header into memory?
1527  FrontendOpts.OutputFile = PreamblePCHPath;
1528  PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1529  PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1530
1531  // Create the compiler instance to use for building the precompiled preamble.
1532  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1533
1534  // Recover resources if we crash before exiting this method.
1535  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1536    CICleanup(Clang.get());
1537
1538  Clang->setInvocation(&*PreambleInvocation);
1539  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
1540
1541  // Set up diagnostics, capturing all of the diagnostics produced.
1542  Clang->setDiagnostics(&getDiagnostics());
1543
1544  // Create the target instance.
1545  Clang->getTargetOpts().Features = TargetFeatures;
1546  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1547                                               Clang->getTargetOpts()));
1548  if (!Clang->hasTarget()) {
1549    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1550    Preamble.clear();
1551    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1552    PreprocessorOpts.eraseRemappedFile(
1553                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1554    return 0;
1555  }
1556
1557  // Inform the target of the language options.
1558  //
1559  // FIXME: We shouldn't need to do this, the target should be immutable once
1560  // created. This complexity should be lifted elsewhere.
1561  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1562
1563  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1564         "Invocation must have exactly one source file!");
1565  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
1566         "FIXME: AST inputs not yet supported here!");
1567  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
1568         "IR inputs not support here!");
1569
1570  // Clear out old caches and data.
1571  getDiagnostics().Reset();
1572  ProcessWarningOptions(getDiagnostics(), Clang->getDiagnosticOpts());
1573  checkAndRemoveNonDriverDiags(StoredDiagnostics);
1574  TopLevelDecls.clear();
1575  TopLevelDeclsInPreamble.clear();
1576
1577  // Create a file manager object to provide access to and cache the filesystem.
1578  Clang->setFileManager(new FileManager(Clang->getFileSystemOpts()));
1579
1580  // Create the source manager.
1581  Clang->setSourceManager(new SourceManager(getDiagnostics(),
1582                                            Clang->getFileManager()));
1583
1584  OwningPtr<PrecompilePreambleAction> Act;
1585  Act.reset(new PrecompilePreambleAction(*this));
1586  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
1587    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1588    Preamble.clear();
1589    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1590    PreprocessorOpts.eraseRemappedFile(
1591                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1592    return 0;
1593  }
1594
1595  Act->Execute();
1596  Act->EndSourceFile();
1597
1598  if (Diagnostics->hasErrorOccurred()) {
1599    // There were errors parsing the preamble, so no precompiled header was
1600    // generated. Forget that we even tried.
1601    // FIXME: Should we leave a note for ourselves to try again?
1602    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1603    Preamble.clear();
1604    TopLevelDeclsInPreamble.clear();
1605    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1606    PreprocessorOpts.eraseRemappedFile(
1607                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1608    return 0;
1609  }
1610
1611  // Transfer any diagnostics generated when parsing the preamble into the set
1612  // of preamble diagnostics.
1613  PreambleDiagnostics.clear();
1614  PreambleDiagnostics.insert(PreambleDiagnostics.end(),
1615                            stored_diag_afterDriver_begin(), stored_diag_end());
1616  checkAndRemoveNonDriverDiags(StoredDiagnostics);
1617
1618  // Keep track of the preamble we precompiled.
1619  setPreambleFile(this, FrontendOpts.OutputFile);
1620  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1621
1622  // Keep track of all of the files that the source manager knows about,
1623  // so we can verify whether they have changed or not.
1624  FilesInPreamble.clear();
1625  SourceManager &SourceMgr = Clang->getSourceManager();
1626  const llvm::MemoryBuffer *MainFileBuffer
1627    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1628  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1629                                     FEnd = SourceMgr.fileinfo_end();
1630       F != FEnd;
1631       ++F) {
1632    const FileEntry *File = F->second->OrigEntry;
1633    if (!File || F->second->getRawBuffer() == MainFileBuffer)
1634      continue;
1635
1636    FilesInPreamble[File->getName()]
1637      = std::make_pair(F->second->getSize(), File->getModificationTime());
1638  }
1639
1640  PreambleRebuildCounter = 1;
1641  PreprocessorOpts.eraseRemappedFile(
1642                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1643
1644  // If the hash of top-level entities differs from the hash of the top-level
1645  // entities the last time we rebuilt the preamble, clear out the completion
1646  // cache.
1647  if (CurrentTopLevelHashValue != PreambleTopLevelHashValue) {
1648    CompletionCacheTopLevelHashValue = 0;
1649    PreambleTopLevelHashValue = CurrentTopLevelHashValue;
1650  }
1651
1652  return CreatePaddedMainFileBuffer(NewPreamble.first,
1653                                    PreambleReservedSize,
1654                                    FrontendOpts.Inputs[0].File);
1655}
1656
1657void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1658  std::vector<Decl *> Resolved;
1659  Resolved.reserve(TopLevelDeclsInPreamble.size());
1660  ExternalASTSource &Source = *getASTContext().getExternalSource();
1661  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1662    // Resolve the declaration ID to an actual declaration, possibly
1663    // deserializing the declaration in the process.
1664    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1665    if (D)
1666      Resolved.push_back(D);
1667  }
1668  TopLevelDeclsInPreamble.clear();
1669  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1670}
1671
1672void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
1673  // Steal the created target, context, and preprocessor.
1674  TheSema.reset(CI.takeSema());
1675  Consumer.reset(CI.takeASTConsumer());
1676  Ctx = &CI.getASTContext();
1677  PP = &CI.getPreprocessor();
1678  CI.setSourceManager(0);
1679  CI.setFileManager(0);
1680  Target = &CI.getTarget();
1681  Reader = CI.getModuleManager();
1682}
1683
1684StringRef ASTUnit::getMainFileName() const {
1685  return Invocation->getFrontendOpts().Inputs[0].File;
1686}
1687
1688ASTUnit *ASTUnit::create(CompilerInvocation *CI,
1689                         IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1690                         bool CaptureDiagnostics,
1691                         bool UserFilesAreVolatile) {
1692  OwningPtr<ASTUnit> AST;
1693  AST.reset(new ASTUnit(false));
1694  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
1695  AST->Diagnostics = Diags;
1696  AST->Invocation = CI;
1697  AST->FileSystemOpts = CI->getFileSystemOpts();
1698  AST->FileMgr = new FileManager(AST->FileSystemOpts);
1699  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1700  AST->SourceMgr = new SourceManager(AST->getDiagnostics(), *AST->FileMgr,
1701                                     UserFilesAreVolatile);
1702
1703  return AST.take();
1704}
1705
1706ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(CompilerInvocation *CI,
1707                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1708                                             ASTFrontendAction *Action,
1709                                             ASTUnit *Unit,
1710                                             bool Persistent,
1711                                             StringRef ResourceFilesPath,
1712                                             bool OnlyLocalDecls,
1713                                             bool CaptureDiagnostics,
1714                                             bool PrecompilePreamble,
1715                                             bool CacheCodeCompletionResults,
1716                                    bool IncludeBriefCommentsInCodeCompletion,
1717                                             bool UserFilesAreVolatile,
1718                                             OwningPtr<ASTUnit> *ErrAST) {
1719  assert(CI && "A CompilerInvocation is required");
1720
1721  OwningPtr<ASTUnit> OwnAST;
1722  ASTUnit *AST = Unit;
1723  if (!AST) {
1724    // Create the AST unit.
1725    OwnAST.reset(create(CI, Diags, CaptureDiagnostics, UserFilesAreVolatile));
1726    AST = OwnAST.get();
1727  }
1728
1729  if (!ResourceFilesPath.empty()) {
1730    // Override the resources path.
1731    CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1732  }
1733  AST->OnlyLocalDecls = OnlyLocalDecls;
1734  AST->CaptureDiagnostics = CaptureDiagnostics;
1735  if (PrecompilePreamble)
1736    AST->PreambleRebuildCounter = 2;
1737  AST->TUKind = Action ? Action->getTranslationUnitKind() : TU_Complete;
1738  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1739  AST->IncludeBriefCommentsInCodeCompletion
1740    = IncludeBriefCommentsInCodeCompletion;
1741
1742  // Recover resources if we crash before exiting this method.
1743  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1744    ASTUnitCleanup(OwnAST.get());
1745  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1746    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1747    DiagCleanup(Diags.getPtr());
1748
1749  // We'll manage file buffers ourselves.
1750  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1751  CI->getFrontendOpts().DisableFree = false;
1752  ProcessWarningOptions(AST->getDiagnostics(), CI->getDiagnosticOpts());
1753
1754  // Save the target features.
1755  AST->TargetFeatures = CI->getTargetOpts().Features;
1756
1757  // Create the compiler instance to use for building the AST.
1758  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1759
1760  // Recover resources if we crash before exiting this method.
1761  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1762    CICleanup(Clang.get());
1763
1764  Clang->setInvocation(CI);
1765  AST->OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
1766
1767  // Set up diagnostics, capturing any diagnostics that would
1768  // otherwise be dropped.
1769  Clang->setDiagnostics(&AST->getDiagnostics());
1770
1771  // Create the target instance.
1772  Clang->getTargetOpts().Features = AST->TargetFeatures;
1773  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1774                   Clang->getTargetOpts()));
1775  if (!Clang->hasTarget())
1776    return 0;
1777
1778  // Inform the target of the language options.
1779  //
1780  // FIXME: We shouldn't need to do this, the target should be immutable once
1781  // created. This complexity should be lifted elsewhere.
1782  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1783
1784  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1785         "Invocation must have exactly one source file!");
1786  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
1787         "FIXME: AST inputs not yet supported here!");
1788  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
1789         "IR inputs not supported here!");
1790
1791  // Configure the various subsystems.
1792  AST->TheSema.reset();
1793  AST->Ctx = 0;
1794  AST->PP = 0;
1795  AST->Reader = 0;
1796
1797  // Create a file manager object to provide access to and cache the filesystem.
1798  Clang->setFileManager(&AST->getFileManager());
1799
1800  // Create the source manager.
1801  Clang->setSourceManager(&AST->getSourceManager());
1802
1803  ASTFrontendAction *Act = Action;
1804
1805  OwningPtr<TopLevelDeclTrackerAction> TrackerAct;
1806  if (!Act) {
1807    TrackerAct.reset(new TopLevelDeclTrackerAction(*AST));
1808    Act = TrackerAct.get();
1809  }
1810
1811  // Recover resources if we crash before exiting this method.
1812  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1813    ActCleanup(TrackerAct.get());
1814
1815  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
1816    AST->transferASTDataFromCompilerInstance(*Clang);
1817    if (OwnAST && ErrAST)
1818      ErrAST->swap(OwnAST);
1819
1820    return 0;
1821  }
1822
1823  if (Persistent && !TrackerAct) {
1824    Clang->getPreprocessor().addPPCallbacks(
1825     new MacroDefinitionTrackerPPCallbacks(AST->getCurrentTopLevelHashValue()));
1826    std::vector<ASTConsumer*> Consumers;
1827    if (Clang->hasASTConsumer())
1828      Consumers.push_back(Clang->takeASTConsumer());
1829    Consumers.push_back(new TopLevelDeclTrackerConsumer(*AST,
1830                                           AST->getCurrentTopLevelHashValue()));
1831    Clang->setASTConsumer(new MultiplexConsumer(Consumers));
1832  }
1833  if (!Act->Execute()) {
1834    AST->transferASTDataFromCompilerInstance(*Clang);
1835    if (OwnAST && ErrAST)
1836      ErrAST->swap(OwnAST);
1837
1838    return 0;
1839  }
1840
1841  // Steal the created target, context, and preprocessor.
1842  AST->transferASTDataFromCompilerInstance(*Clang);
1843
1844  Act->EndSourceFile();
1845
1846  if (OwnAST)
1847    return OwnAST.take();
1848  else
1849    return AST;
1850}
1851
1852bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
1853  if (!Invocation)
1854    return true;
1855
1856  // We'll manage file buffers ourselves.
1857  Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1858  Invocation->getFrontendOpts().DisableFree = false;
1859  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1860
1861  // Save the target features.
1862  TargetFeatures = Invocation->getTargetOpts().Features;
1863
1864  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1865  if (PrecompilePreamble) {
1866    PreambleRebuildCounter = 2;
1867    OverrideMainBuffer
1868      = getMainBufferWithPrecompiledPreamble(*Invocation);
1869  }
1870
1871  SimpleTimer ParsingTimer(WantTiming);
1872  ParsingTimer.setOutput("Parsing " + getMainFileName());
1873
1874  // Recover resources if we crash before exiting this method.
1875  llvm::CrashRecoveryContextCleanupRegistrar<llvm::MemoryBuffer>
1876    MemBufferCleanup(OverrideMainBuffer);
1877
1878  return Parse(OverrideMainBuffer);
1879}
1880
1881ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1882                              IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1883                                             bool OnlyLocalDecls,
1884                                             bool CaptureDiagnostics,
1885                                             bool PrecompilePreamble,
1886                                             TranslationUnitKind TUKind,
1887                                             bool CacheCodeCompletionResults,
1888                                    bool IncludeBriefCommentsInCodeCompletion,
1889                                             bool UserFilesAreVolatile) {
1890  // Create the AST unit.
1891  OwningPtr<ASTUnit> AST;
1892  AST.reset(new ASTUnit(false));
1893  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
1894  AST->Diagnostics = Diags;
1895  AST->OnlyLocalDecls = OnlyLocalDecls;
1896  AST->CaptureDiagnostics = CaptureDiagnostics;
1897  AST->TUKind = TUKind;
1898  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1899  AST->IncludeBriefCommentsInCodeCompletion
1900    = IncludeBriefCommentsInCodeCompletion;
1901  AST->Invocation = CI;
1902  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1903
1904  // Recover resources if we crash before exiting this method.
1905  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1906    ASTUnitCleanup(AST.get());
1907  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1908    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1909    DiagCleanup(Diags.getPtr());
1910
1911  return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
1912}
1913
1914ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1915                                      const char **ArgEnd,
1916                                    IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1917                                      StringRef ResourceFilesPath,
1918                                      bool OnlyLocalDecls,
1919                                      bool CaptureDiagnostics,
1920                                      RemappedFile *RemappedFiles,
1921                                      unsigned NumRemappedFiles,
1922                                      bool RemappedFilesKeepOriginalName,
1923                                      bool PrecompilePreamble,
1924                                      TranslationUnitKind TUKind,
1925                                      bool CacheCodeCompletionResults,
1926                                      bool IncludeBriefCommentsInCodeCompletion,
1927                                      bool AllowPCHWithCompilerErrors,
1928                                      bool SkipFunctionBodies,
1929                                      bool UserFilesAreVolatile,
1930                                      OwningPtr<ASTUnit> *ErrAST) {
1931  if (!Diags.getPtr()) {
1932    // No diagnostics engine was provided, so create our own diagnostics object
1933    // with the default options.
1934    DiagnosticOptions DiagOpts;
1935    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd - ArgBegin,
1936                                                ArgBegin);
1937  }
1938
1939  SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
1940
1941  IntrusiveRefCntPtr<CompilerInvocation> CI;
1942
1943  {
1944
1945    CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags,
1946                                      StoredDiagnostics);
1947
1948    CI = clang::createInvocationFromCommandLine(
1949                                           llvm::makeArrayRef(ArgBegin, ArgEnd),
1950                                           Diags);
1951    if (!CI)
1952      return 0;
1953  }
1954
1955  // Override any files that need remapping
1956  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1957    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
1958    if (const llvm::MemoryBuffer *
1959            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
1960      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, memBuf);
1961    } else {
1962      const char *fname = fileOrBuf.get<const char *>();
1963      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, fname);
1964    }
1965  }
1966  PreprocessorOptions &PPOpts = CI->getPreprocessorOpts();
1967  PPOpts.RemappedFilesKeepOriginalName = RemappedFilesKeepOriginalName;
1968  PPOpts.AllowPCHWithCompilerErrors = AllowPCHWithCompilerErrors;
1969
1970  // Override the resources path.
1971  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1972
1973  CI->getFrontendOpts().SkipFunctionBodies = SkipFunctionBodies;
1974
1975  // Create the AST unit.
1976  OwningPtr<ASTUnit> AST;
1977  AST.reset(new ASTUnit(false));
1978  ConfigureDiags(Diags, ArgBegin, ArgEnd, *AST, CaptureDiagnostics);
1979  AST->Diagnostics = Diags;
1980  Diags = 0; // Zero out now to ease cleanup during crash recovery.
1981  AST->FileSystemOpts = CI->getFileSystemOpts();
1982  AST->FileMgr = new FileManager(AST->FileSystemOpts);
1983  AST->OnlyLocalDecls = OnlyLocalDecls;
1984  AST->CaptureDiagnostics = CaptureDiagnostics;
1985  AST->TUKind = TUKind;
1986  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1987  AST->IncludeBriefCommentsInCodeCompletion
1988    = IncludeBriefCommentsInCodeCompletion;
1989  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1990  AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
1991  AST->StoredDiagnostics.swap(StoredDiagnostics);
1992  AST->Invocation = CI;
1993  CI = 0; // Zero out now to ease cleanup during crash recovery.
1994
1995  // Recover resources if we crash before exiting this method.
1996  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1997    ASTUnitCleanup(AST.get());
1998
1999  if (AST->LoadFromCompilerInvocation(PrecompilePreamble)) {
2000    // Some error occurred, if caller wants to examine diagnostics, pass it the
2001    // ASTUnit.
2002    if (ErrAST) {
2003      AST->StoredDiagnostics.swap(AST->FailedParseDiagnostics);
2004      ErrAST->swap(AST);
2005    }
2006    return 0;
2007  }
2008
2009  return AST.take();
2010}
2011
2012bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
2013  if (!Invocation)
2014    return true;
2015
2016  clearFileLevelDecls();
2017
2018  SimpleTimer ParsingTimer(WantTiming);
2019  ParsingTimer.setOutput("Reparsing " + getMainFileName());
2020
2021  // Remap files.
2022  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
2023  PPOpts.DisableStatCache = true;
2024  for (PreprocessorOptions::remapped_file_buffer_iterator
2025         R = PPOpts.remapped_file_buffer_begin(),
2026         REnd = PPOpts.remapped_file_buffer_end();
2027       R != REnd;
2028       ++R) {
2029    delete R->second;
2030  }
2031  Invocation->getPreprocessorOpts().clearRemappedFiles();
2032  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
2033    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
2034    if (const llvm::MemoryBuffer *
2035            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
2036      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
2037                                                        memBuf);
2038    } else {
2039      const char *fname = fileOrBuf.get<const char *>();
2040      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
2041                                                        fname);
2042    }
2043  }
2044
2045  // If we have a preamble file lying around, or if we might try to
2046  // build a precompiled preamble, do so now.
2047  llvm::MemoryBuffer *OverrideMainBuffer = 0;
2048  if (!getPreambleFile(this).empty() || PreambleRebuildCounter > 0)
2049    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
2050
2051  // Clear out the diagnostics state.
2052  getDiagnostics().Reset();
2053  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
2054  if (OverrideMainBuffer)
2055    getDiagnostics().setNumWarnings(NumWarningsInPreamble);
2056
2057  // Parse the sources
2058  bool Result = Parse(OverrideMainBuffer);
2059
2060  // If we're caching global code-completion results, and the top-level
2061  // declarations have changed, clear out the code-completion cache.
2062  if (!Result && ShouldCacheCodeCompletionResults &&
2063      CurrentTopLevelHashValue != CompletionCacheTopLevelHashValue)
2064    CacheCodeCompletionResults();
2065
2066  // We now need to clear out the completion info related to this translation
2067  // unit; it'll be recreated if necessary.
2068  CCTUInfo.reset();
2069
2070  return Result;
2071}
2072
2073//----------------------------------------------------------------------------//
2074// Code completion
2075//----------------------------------------------------------------------------//
2076
2077namespace {
2078  /// \brief Code completion consumer that combines the cached code-completion
2079  /// results from an ASTUnit with the code-completion results provided to it,
2080  /// then passes the result on to
2081  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
2082    uint64_t NormalContexts;
2083    ASTUnit &AST;
2084    CodeCompleteConsumer &Next;
2085
2086  public:
2087    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
2088                                  const CodeCompleteOptions &CodeCompleteOpts)
2089      : CodeCompleteConsumer(CodeCompleteOpts, Next.isOutputBinary()),
2090        AST(AST), Next(Next)
2091    {
2092      // Compute the set of contexts in which we will look when we don't have
2093      // any information about the specific context.
2094      NormalContexts
2095        = (1LL << CodeCompletionContext::CCC_TopLevel)
2096        | (1LL << CodeCompletionContext::CCC_ObjCInterface)
2097        | (1LL << CodeCompletionContext::CCC_ObjCImplementation)
2098        | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
2099        | (1LL << CodeCompletionContext::CCC_Statement)
2100        | (1LL << CodeCompletionContext::CCC_Expression)
2101        | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
2102        | (1LL << CodeCompletionContext::CCC_DotMemberAccess)
2103        | (1LL << CodeCompletionContext::CCC_ArrowMemberAccess)
2104        | (1LL << CodeCompletionContext::CCC_ObjCPropertyAccess)
2105        | (1LL << CodeCompletionContext::CCC_ObjCProtocolName)
2106        | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression)
2107        | (1LL << CodeCompletionContext::CCC_Recovery);
2108
2109      if (AST.getASTContext().getLangOpts().CPlusPlus)
2110        NormalContexts |= (1LL << CodeCompletionContext::CCC_EnumTag)
2111                       |  (1LL << CodeCompletionContext::CCC_UnionTag)
2112                       |  (1LL << CodeCompletionContext::CCC_ClassOrStructTag);
2113    }
2114
2115    virtual void ProcessCodeCompleteResults(Sema &S,
2116                                            CodeCompletionContext Context,
2117                                            CodeCompletionResult *Results,
2118                                            unsigned NumResults);
2119
2120    virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
2121                                           OverloadCandidate *Candidates,
2122                                           unsigned NumCandidates) {
2123      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
2124    }
2125
2126    virtual CodeCompletionAllocator &getAllocator() {
2127      return Next.getAllocator();
2128    }
2129
2130    virtual CodeCompletionTUInfo &getCodeCompletionTUInfo() {
2131      return Next.getCodeCompletionTUInfo();
2132    }
2133  };
2134}
2135
2136/// \brief Helper function that computes which global names are hidden by the
2137/// local code-completion results.
2138static void CalculateHiddenNames(const CodeCompletionContext &Context,
2139                                 CodeCompletionResult *Results,
2140                                 unsigned NumResults,
2141                                 ASTContext &Ctx,
2142                          llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
2143  bool OnlyTagNames = false;
2144  switch (Context.getKind()) {
2145  case CodeCompletionContext::CCC_Recovery:
2146  case CodeCompletionContext::CCC_TopLevel:
2147  case CodeCompletionContext::CCC_ObjCInterface:
2148  case CodeCompletionContext::CCC_ObjCImplementation:
2149  case CodeCompletionContext::CCC_ObjCIvarList:
2150  case CodeCompletionContext::CCC_ClassStructUnion:
2151  case CodeCompletionContext::CCC_Statement:
2152  case CodeCompletionContext::CCC_Expression:
2153  case CodeCompletionContext::CCC_ObjCMessageReceiver:
2154  case CodeCompletionContext::CCC_DotMemberAccess:
2155  case CodeCompletionContext::CCC_ArrowMemberAccess:
2156  case CodeCompletionContext::CCC_ObjCPropertyAccess:
2157  case CodeCompletionContext::CCC_Namespace:
2158  case CodeCompletionContext::CCC_Type:
2159  case CodeCompletionContext::CCC_Name:
2160  case CodeCompletionContext::CCC_PotentiallyQualifiedName:
2161  case CodeCompletionContext::CCC_ParenthesizedExpression:
2162  case CodeCompletionContext::CCC_ObjCInterfaceName:
2163    break;
2164
2165  case CodeCompletionContext::CCC_EnumTag:
2166  case CodeCompletionContext::CCC_UnionTag:
2167  case CodeCompletionContext::CCC_ClassOrStructTag:
2168    OnlyTagNames = true;
2169    break;
2170
2171  case CodeCompletionContext::CCC_ObjCProtocolName:
2172  case CodeCompletionContext::CCC_MacroName:
2173  case CodeCompletionContext::CCC_MacroNameUse:
2174  case CodeCompletionContext::CCC_PreprocessorExpression:
2175  case CodeCompletionContext::CCC_PreprocessorDirective:
2176  case CodeCompletionContext::CCC_NaturalLanguage:
2177  case CodeCompletionContext::CCC_SelectorName:
2178  case CodeCompletionContext::CCC_TypeQualifiers:
2179  case CodeCompletionContext::CCC_Other:
2180  case CodeCompletionContext::CCC_OtherWithMacros:
2181  case CodeCompletionContext::CCC_ObjCInstanceMessage:
2182  case CodeCompletionContext::CCC_ObjCClassMessage:
2183  case CodeCompletionContext::CCC_ObjCCategoryName:
2184    // We're looking for nothing, or we're looking for names that cannot
2185    // be hidden.
2186    return;
2187  }
2188
2189  typedef CodeCompletionResult Result;
2190  for (unsigned I = 0; I != NumResults; ++I) {
2191    if (Results[I].Kind != Result::RK_Declaration)
2192      continue;
2193
2194    unsigned IDNS
2195      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
2196
2197    bool Hiding = false;
2198    if (OnlyTagNames)
2199      Hiding = (IDNS & Decl::IDNS_Tag);
2200    else {
2201      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
2202                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
2203                             Decl::IDNS_NonMemberOperator);
2204      if (Ctx.getLangOpts().CPlusPlus)
2205        HiddenIDNS |= Decl::IDNS_Tag;
2206      Hiding = (IDNS & HiddenIDNS);
2207    }
2208
2209    if (!Hiding)
2210      continue;
2211
2212    DeclarationName Name = Results[I].Declaration->getDeclName();
2213    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
2214      HiddenNames.insert(Identifier->getName());
2215    else
2216      HiddenNames.insert(Name.getAsString());
2217  }
2218}
2219
2220
2221void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
2222                                            CodeCompletionContext Context,
2223                                            CodeCompletionResult *Results,
2224                                            unsigned NumResults) {
2225  // Merge the results we were given with the results we cached.
2226  bool AddedResult = false;
2227  uint64_t InContexts =
2228      Context.getKind() == CodeCompletionContext::CCC_Recovery
2229        ? NormalContexts : (1LL << Context.getKind());
2230  // Contains the set of names that are hidden by "local" completion results.
2231  llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
2232  typedef CodeCompletionResult Result;
2233  SmallVector<Result, 8> AllResults;
2234  for (ASTUnit::cached_completion_iterator
2235            C = AST.cached_completion_begin(),
2236         CEnd = AST.cached_completion_end();
2237       C != CEnd; ++C) {
2238    // If the context we are in matches any of the contexts we are
2239    // interested in, we'll add this result.
2240    if ((C->ShowInContexts & InContexts) == 0)
2241      continue;
2242
2243    // If we haven't added any results previously, do so now.
2244    if (!AddedResult) {
2245      CalculateHiddenNames(Context, Results, NumResults, S.Context,
2246                           HiddenNames);
2247      AllResults.insert(AllResults.end(), Results, Results + NumResults);
2248      AddedResult = true;
2249    }
2250
2251    // Determine whether this global completion result is hidden by a local
2252    // completion result. If so, skip it.
2253    if (C->Kind != CXCursor_MacroDefinition &&
2254        HiddenNames.count(C->Completion->getTypedText()))
2255      continue;
2256
2257    // Adjust priority based on similar type classes.
2258    unsigned Priority = C->Priority;
2259    CodeCompletionString *Completion = C->Completion;
2260    if (!Context.getPreferredType().isNull()) {
2261      if (C->Kind == CXCursor_MacroDefinition) {
2262        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
2263                                         S.getLangOpts(),
2264                               Context.getPreferredType()->isAnyPointerType());
2265      } else if (C->Type) {
2266        CanQualType Expected
2267          = S.Context.getCanonicalType(
2268                               Context.getPreferredType().getUnqualifiedType());
2269        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
2270        if (ExpectedSTC == C->TypeClass) {
2271          // We know this type is similar; check for an exact match.
2272          llvm::StringMap<unsigned> &CachedCompletionTypes
2273            = AST.getCachedCompletionTypes();
2274          llvm::StringMap<unsigned>::iterator Pos
2275            = CachedCompletionTypes.find(QualType(Expected).getAsString());
2276          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
2277            Priority /= CCF_ExactTypeMatch;
2278          else
2279            Priority /= CCF_SimilarTypeMatch;
2280        }
2281      }
2282    }
2283
2284    // Adjust the completion string, if required.
2285    if (C->Kind == CXCursor_MacroDefinition &&
2286        Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
2287      // Create a new code-completion string that just contains the
2288      // macro name, without its arguments.
2289      CodeCompletionBuilder Builder(getAllocator(), getCodeCompletionTUInfo(),
2290                                    CCP_CodePattern, C->Availability);
2291      Builder.AddTypedTextChunk(C->Completion->getTypedText());
2292      Priority = CCP_CodePattern;
2293      Completion = Builder.TakeString();
2294    }
2295
2296    AllResults.push_back(Result(Completion, Priority, C->Kind,
2297                                C->Availability));
2298  }
2299
2300  // If we did not add any cached completion results, just forward the
2301  // results we were given to the next consumer.
2302  if (!AddedResult) {
2303    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
2304    return;
2305  }
2306
2307  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
2308                                  AllResults.size());
2309}
2310
2311
2312
2313void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
2314                           RemappedFile *RemappedFiles,
2315                           unsigned NumRemappedFiles,
2316                           bool IncludeMacros,
2317                           bool IncludeCodePatterns,
2318                           bool IncludeBriefComments,
2319                           CodeCompleteConsumer &Consumer,
2320                           DiagnosticsEngine &Diag, LangOptions &LangOpts,
2321                           SourceManager &SourceMgr, FileManager &FileMgr,
2322                   SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
2323             SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
2324  if (!Invocation)
2325    return;
2326
2327  SimpleTimer CompletionTimer(WantTiming);
2328  CompletionTimer.setOutput("Code completion @ " + File + ":" +
2329                            Twine(Line) + ":" + Twine(Column));
2330
2331  IntrusiveRefCntPtr<CompilerInvocation>
2332    CCInvocation(new CompilerInvocation(*Invocation));
2333
2334  FrontendOptions &FrontendOpts = CCInvocation->getFrontendOpts();
2335  CodeCompleteOptions &CodeCompleteOpts = FrontendOpts.CodeCompleteOpts;
2336  PreprocessorOptions &PreprocessorOpts = CCInvocation->getPreprocessorOpts();
2337
2338  CodeCompleteOpts.IncludeMacros = IncludeMacros &&
2339                                   CachedCompletionResults.empty();
2340  CodeCompleteOpts.IncludeCodePatterns = IncludeCodePatterns;
2341  CodeCompleteOpts.IncludeGlobals = CachedCompletionResults.empty();
2342  CodeCompleteOpts.IncludeBriefComments = IncludeBriefComments;
2343
2344  assert(IncludeBriefComments == this->IncludeBriefCommentsInCodeCompletion);
2345
2346  FrontendOpts.CodeCompletionAt.FileName = File;
2347  FrontendOpts.CodeCompletionAt.Line = Line;
2348  FrontendOpts.CodeCompletionAt.Column = Column;
2349
2350  // Set the language options appropriately.
2351  LangOpts = *CCInvocation->getLangOpts();
2352
2353  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
2354
2355  // Recover resources if we crash before exiting this method.
2356  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
2357    CICleanup(Clang.get());
2358
2359  Clang->setInvocation(&*CCInvocation);
2360  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].File;
2361
2362  // Set up diagnostics, capturing any diagnostics produced.
2363  Clang->setDiagnostics(&Diag);
2364  ProcessWarningOptions(Diag, CCInvocation->getDiagnosticOpts());
2365  CaptureDroppedDiagnostics Capture(true,
2366                                    Clang->getDiagnostics(),
2367                                    StoredDiagnostics);
2368
2369  // Create the target instance.
2370  Clang->getTargetOpts().Features = TargetFeatures;
2371  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
2372                                               Clang->getTargetOpts()));
2373  if (!Clang->hasTarget()) {
2374    Clang->setInvocation(0);
2375    return;
2376  }
2377
2378  // Inform the target of the language options.
2379  //
2380  // FIXME: We shouldn't need to do this, the target should be immutable once
2381  // created. This complexity should be lifted elsewhere.
2382  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
2383
2384  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
2385         "Invocation must have exactly one source file!");
2386  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_AST &&
2387         "FIXME: AST inputs not yet supported here!");
2388  assert(Clang->getFrontendOpts().Inputs[0].Kind != IK_LLVM_IR &&
2389         "IR inputs not support here!");
2390
2391
2392  // Use the source and file managers that we were given.
2393  Clang->setFileManager(&FileMgr);
2394  Clang->setSourceManager(&SourceMgr);
2395
2396  // Remap files.
2397  PreprocessorOpts.clearRemappedFiles();
2398  PreprocessorOpts.RetainRemappedFileBuffers = true;
2399  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
2400    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
2401    if (const llvm::MemoryBuffer *
2402            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
2403      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, memBuf);
2404      OwnedBuffers.push_back(memBuf);
2405    } else {
2406      const char *fname = fileOrBuf.get<const char *>();
2407      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, fname);
2408    }
2409  }
2410
2411  // Use the code completion consumer we were given, but adding any cached
2412  // code-completion results.
2413  AugmentedCodeCompleteConsumer *AugmentedConsumer
2414    = new AugmentedCodeCompleteConsumer(*this, Consumer, CodeCompleteOpts);
2415  Clang->setCodeCompletionConsumer(AugmentedConsumer);
2416
2417  Clang->getFrontendOpts().SkipFunctionBodies = true;
2418
2419  // If we have a precompiled preamble, try to use it. We only allow
2420  // the use of the precompiled preamble if we're if the completion
2421  // point is within the main file, after the end of the precompiled
2422  // preamble.
2423  llvm::MemoryBuffer *OverrideMainBuffer = 0;
2424  if (!getPreambleFile(this).empty()) {
2425    using llvm::sys::FileStatus;
2426    llvm::sys::PathWithStatus CompleteFilePath(File);
2427    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
2428    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
2429      if (const FileStatus *MainStatus = MainPath.getFileStatus())
2430        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID() &&
2431            Line > 1)
2432          OverrideMainBuffer
2433            = getMainBufferWithPrecompiledPreamble(*CCInvocation, false,
2434                                                   Line - 1);
2435  }
2436
2437  // If the main file has been overridden due to the use of a preamble,
2438  // make that override happen and introduce the preamble.
2439  PreprocessorOpts.DisableStatCache = true;
2440  StoredDiagnostics.insert(StoredDiagnostics.end(),
2441                           stored_diag_begin(),
2442                           stored_diag_afterDriver_begin());
2443  if (OverrideMainBuffer) {
2444    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
2445    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
2446    PreprocessorOpts.PrecompiledPreambleBytes.second
2447                                                    = PreambleEndsAtStartOfLine;
2448    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
2449    PreprocessorOpts.DisablePCHValidation = true;
2450
2451    OwnedBuffers.push_back(OverrideMainBuffer);
2452  } else {
2453    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
2454    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
2455  }
2456
2457  // Disable the preprocessing record
2458  PreprocessorOpts.DetailedRecord = false;
2459
2460  OwningPtr<SyntaxOnlyAction> Act;
2461  Act.reset(new SyntaxOnlyAction);
2462  if (Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
2463    if (OverrideMainBuffer) {
2464      std::string ModName = getPreambleFile(this);
2465      TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
2466                                 getSourceManager(), PreambleDiagnostics,
2467                                 StoredDiagnostics);
2468    }
2469    Act->Execute();
2470    Act->EndSourceFile();
2471  }
2472
2473  checkAndSanitizeDiags(StoredDiagnostics, getSourceManager());
2474}
2475
2476bool ASTUnit::Save(StringRef File) {
2477  // Write to a temporary file and later rename it to the actual file, to avoid
2478  // possible race conditions.
2479  SmallString<128> TempPath;
2480  TempPath = File;
2481  TempPath += "-%%%%%%%%";
2482  int fd;
2483  if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
2484                                 /*makeAbsolute=*/false))
2485    return true;
2486
2487  // FIXME: Can we somehow regenerate the stat cache here, or do we need to
2488  // unconditionally create a stat cache when we parse the file?
2489  llvm::raw_fd_ostream Out(fd, /*shouldClose=*/true);
2490
2491  serialize(Out);
2492  Out.close();
2493  if (Out.has_error()) {
2494    Out.clear_error();
2495    return true;
2496  }
2497
2498  if (llvm::sys::fs::rename(TempPath.str(), File)) {
2499    bool exists;
2500    llvm::sys::fs::remove(TempPath.str(), exists);
2501    return true;
2502  }
2503
2504  return false;
2505}
2506
2507bool ASTUnit::serialize(raw_ostream &OS) {
2508  bool hasErrors = getDiagnostics().hasErrorOccurred();
2509
2510  SmallString<128> Buffer;
2511  llvm::BitstreamWriter Stream(Buffer);
2512  ASTWriter Writer(Stream);
2513  // FIXME: Handle modules
2514  Writer.WriteAST(getSema(), 0, std::string(), 0, "", hasErrors);
2515
2516  // Write the generated bitstream to "Out".
2517  if (!Buffer.empty())
2518    OS.write((char *)&Buffer.front(), Buffer.size());
2519
2520  return false;
2521}
2522
2523typedef ContinuousRangeMap<unsigned, int, 2> SLocRemap;
2524
2525static void TranslateSLoc(SourceLocation &L, SLocRemap &Remap) {
2526  unsigned Raw = L.getRawEncoding();
2527  const unsigned MacroBit = 1U << 31;
2528  L = SourceLocation::getFromRawEncoding((Raw & MacroBit) |
2529      ((Raw & ~MacroBit) + Remap.find(Raw & ~MacroBit)->second));
2530}
2531
2532void ASTUnit::TranslateStoredDiagnostics(
2533                          ASTReader *MMan,
2534                          StringRef ModName,
2535                          SourceManager &SrcMgr,
2536                          const SmallVectorImpl<StoredDiagnostic> &Diags,
2537                          SmallVectorImpl<StoredDiagnostic> &Out) {
2538  // The stored diagnostic has the old source manager in it; update
2539  // the locations to refer into the new source manager. We also need to remap
2540  // all the locations to the new view. This includes the diag location, any
2541  // associated source ranges, and the source ranges of associated fix-its.
2542  // FIXME: There should be a cleaner way to do this.
2543
2544  SmallVector<StoredDiagnostic, 4> Result;
2545  Result.reserve(Diags.size());
2546  assert(MMan && "Don't have a module manager");
2547  serialization::ModuleFile *Mod = MMan->ModuleMgr.lookup(ModName);
2548  assert(Mod && "Don't have preamble module");
2549  SLocRemap &Remap = Mod->SLocRemap;
2550  for (unsigned I = 0, N = Diags.size(); I != N; ++I) {
2551    // Rebuild the StoredDiagnostic.
2552    const StoredDiagnostic &SD = Diags[I];
2553    SourceLocation L = SD.getLocation();
2554    TranslateSLoc(L, Remap);
2555    FullSourceLoc Loc(L, SrcMgr);
2556
2557    SmallVector<CharSourceRange, 4> Ranges;
2558    Ranges.reserve(SD.range_size());
2559    for (StoredDiagnostic::range_iterator I = SD.range_begin(),
2560                                          E = SD.range_end();
2561         I != E; ++I) {
2562      SourceLocation BL = I->getBegin();
2563      TranslateSLoc(BL, Remap);
2564      SourceLocation EL = I->getEnd();
2565      TranslateSLoc(EL, Remap);
2566      Ranges.push_back(CharSourceRange(SourceRange(BL, EL), I->isTokenRange()));
2567    }
2568
2569    SmallVector<FixItHint, 2> FixIts;
2570    FixIts.reserve(SD.fixit_size());
2571    for (StoredDiagnostic::fixit_iterator I = SD.fixit_begin(),
2572                                          E = SD.fixit_end();
2573         I != E; ++I) {
2574      FixIts.push_back(FixItHint());
2575      FixItHint &FH = FixIts.back();
2576      FH.CodeToInsert = I->CodeToInsert;
2577      SourceLocation BL = I->RemoveRange.getBegin();
2578      TranslateSLoc(BL, Remap);
2579      SourceLocation EL = I->RemoveRange.getEnd();
2580      TranslateSLoc(EL, Remap);
2581      FH.RemoveRange = CharSourceRange(SourceRange(BL, EL),
2582                                       I->RemoveRange.isTokenRange());
2583    }
2584
2585    Result.push_back(StoredDiagnostic(SD.getLevel(), SD.getID(),
2586                                      SD.getMessage(), Loc, Ranges, FixIts));
2587  }
2588  Result.swap(Out);
2589}
2590
2591static inline bool compLocDecl(std::pair<unsigned, Decl *> L,
2592                               std::pair<unsigned, Decl *> R) {
2593  return L.first < R.first;
2594}
2595
2596void ASTUnit::addFileLevelDecl(Decl *D) {
2597  assert(D);
2598
2599  // We only care about local declarations.
2600  if (D->isFromASTFile())
2601    return;
2602
2603  SourceManager &SM = *SourceMgr;
2604  SourceLocation Loc = D->getLocation();
2605  if (Loc.isInvalid() || !SM.isLocalSourceLocation(Loc))
2606    return;
2607
2608  // We only keep track of the file-level declarations of each file.
2609  if (!D->getLexicalDeclContext()->isFileContext())
2610    return;
2611
2612  SourceLocation FileLoc = SM.getFileLoc(Loc);
2613  assert(SM.isLocalSourceLocation(FileLoc));
2614  FileID FID;
2615  unsigned Offset;
2616  llvm::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
2617  if (FID.isInvalid())
2618    return;
2619
2620  LocDeclsTy *&Decls = FileDecls[FID];
2621  if (!Decls)
2622    Decls = new LocDeclsTy();
2623
2624  std::pair<unsigned, Decl *> LocDecl(Offset, D);
2625
2626  if (Decls->empty() || Decls->back().first <= Offset) {
2627    Decls->push_back(LocDecl);
2628    return;
2629  }
2630
2631  LocDeclsTy::iterator
2632    I = std::upper_bound(Decls->begin(), Decls->end(), LocDecl, compLocDecl);
2633
2634  Decls->insert(I, LocDecl);
2635}
2636
2637void ASTUnit::findFileRegionDecls(FileID File, unsigned Offset, unsigned Length,
2638                                  SmallVectorImpl<Decl *> &Decls) {
2639  if (File.isInvalid())
2640    return;
2641
2642  if (SourceMgr->isLoadedFileID(File)) {
2643    assert(Ctx->getExternalSource() && "No external source!");
2644    return Ctx->getExternalSource()->FindFileRegionDecls(File, Offset, Length,
2645                                                         Decls);
2646  }
2647
2648  FileDeclsTy::iterator I = FileDecls.find(File);
2649  if (I == FileDecls.end())
2650    return;
2651
2652  LocDeclsTy &LocDecls = *I->second;
2653  if (LocDecls.empty())
2654    return;
2655
2656  LocDeclsTy::iterator
2657    BeginIt = std::lower_bound(LocDecls.begin(), LocDecls.end(),
2658                               std::make_pair(Offset, (Decl*)0), compLocDecl);
2659  if (BeginIt != LocDecls.begin())
2660    --BeginIt;
2661
2662  // If we are pointing at a top-level decl inside an objc container, we need
2663  // to backtrack until we find it otherwise we will fail to report that the
2664  // region overlaps with an objc container.
2665  while (BeginIt != LocDecls.begin() &&
2666         BeginIt->second->isTopLevelDeclInObjCContainer())
2667    --BeginIt;
2668
2669  LocDeclsTy::iterator
2670    EndIt = std::upper_bound(LocDecls.begin(), LocDecls.end(),
2671                             std::make_pair(Offset+Length, (Decl*)0),
2672                             compLocDecl);
2673  if (EndIt != LocDecls.end())
2674    ++EndIt;
2675
2676  for (LocDeclsTy::iterator DIt = BeginIt; DIt != EndIt; ++DIt)
2677    Decls.push_back(DIt->second);
2678}
2679
2680SourceLocation ASTUnit::getLocation(const FileEntry *File,
2681                                    unsigned Line, unsigned Col) const {
2682  const SourceManager &SM = getSourceManager();
2683  SourceLocation Loc = SM.translateFileLineCol(File, Line, Col);
2684  return SM.getMacroArgExpandedLocation(Loc);
2685}
2686
2687SourceLocation ASTUnit::getLocation(const FileEntry *File,
2688                                    unsigned Offset) const {
2689  const SourceManager &SM = getSourceManager();
2690  SourceLocation FileLoc = SM.translateFileLineCol(File, 1, 1);
2691  return SM.getMacroArgExpandedLocation(FileLoc.getLocWithOffset(Offset));
2692}
2693
2694/// \brief If \arg Loc is a loaded location from the preamble, returns
2695/// the corresponding local location of the main file, otherwise it returns
2696/// \arg Loc.
2697SourceLocation ASTUnit::mapLocationFromPreamble(SourceLocation Loc) {
2698  FileID PreambleID;
2699  if (SourceMgr)
2700    PreambleID = SourceMgr->getPreambleFileID();
2701
2702  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2703    return Loc;
2704
2705  unsigned Offs;
2706  if (SourceMgr->isInFileID(Loc, PreambleID, &Offs) && Offs < Preamble.size()) {
2707    SourceLocation FileLoc
2708        = SourceMgr->getLocForStartOfFile(SourceMgr->getMainFileID());
2709    return FileLoc.getLocWithOffset(Offs);
2710  }
2711
2712  return Loc;
2713}
2714
2715/// \brief If \arg Loc is a local location of the main file but inside the
2716/// preamble chunk, returns the corresponding loaded location from the
2717/// preamble, otherwise it returns \arg Loc.
2718SourceLocation ASTUnit::mapLocationToPreamble(SourceLocation Loc) {
2719  FileID PreambleID;
2720  if (SourceMgr)
2721    PreambleID = SourceMgr->getPreambleFileID();
2722
2723  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2724    return Loc;
2725
2726  unsigned Offs;
2727  if (SourceMgr->isInFileID(Loc, SourceMgr->getMainFileID(), &Offs) &&
2728      Offs < Preamble.size()) {
2729    SourceLocation FileLoc = SourceMgr->getLocForStartOfFile(PreambleID);
2730    return FileLoc.getLocWithOffset(Offs);
2731  }
2732
2733  return Loc;
2734}
2735
2736bool ASTUnit::isInPreambleFileID(SourceLocation Loc) {
2737  FileID FID;
2738  if (SourceMgr)
2739    FID = SourceMgr->getPreambleFileID();
2740
2741  if (Loc.isInvalid() || FID.isInvalid())
2742    return false;
2743
2744  return SourceMgr->isInFileID(Loc, FID);
2745}
2746
2747bool ASTUnit::isInMainFileID(SourceLocation Loc) {
2748  FileID FID;
2749  if (SourceMgr)
2750    FID = SourceMgr->getMainFileID();
2751
2752  if (Loc.isInvalid() || FID.isInvalid())
2753    return false;
2754
2755  return SourceMgr->isInFileID(Loc, FID);
2756}
2757
2758SourceLocation ASTUnit::getEndOfPreambleFileID() {
2759  FileID FID;
2760  if (SourceMgr)
2761    FID = SourceMgr->getPreambleFileID();
2762
2763  if (FID.isInvalid())
2764    return SourceLocation();
2765
2766  return SourceMgr->getLocForEndOfFile(FID);
2767}
2768
2769SourceLocation ASTUnit::getStartOfMainFileID() {
2770  FileID FID;
2771  if (SourceMgr)
2772    FID = SourceMgr->getMainFileID();
2773
2774  if (FID.isInvalid())
2775    return SourceLocation();
2776
2777  return SourceMgr->getLocForStartOfFile(FID);
2778}
2779
2780void ASTUnit::PreambleData::countLines() const {
2781  NumLines = 0;
2782  if (empty())
2783    return;
2784
2785  for (std::vector<char>::const_iterator
2786         I = Buffer.begin(), E = Buffer.end(); I != E; ++I) {
2787    if (*I == '\n')
2788      ++NumLines;
2789  }
2790  if (Buffer.back() != '\n')
2791    ++NumLines;
2792}
2793
2794#ifndef NDEBUG
2795ASTUnit::ConcurrencyState::ConcurrencyState() {
2796  Mutex = new llvm::sys::MutexImpl(/*recursive=*/true);
2797}
2798
2799ASTUnit::ConcurrencyState::~ConcurrencyState() {
2800  delete static_cast<llvm::sys::MutexImpl *>(Mutex);
2801}
2802
2803void ASTUnit::ConcurrencyState::start() {
2804  bool acquired = static_cast<llvm::sys::MutexImpl *>(Mutex)->tryacquire();
2805  assert(acquired && "Concurrent access to ASTUnit!");
2806}
2807
2808void ASTUnit::ConcurrencyState::finish() {
2809  static_cast<llvm::sys::MutexImpl *>(Mutex)->release();
2810}
2811
2812#else // NDEBUG
2813
2814ASTUnit::ConcurrencyState::ConcurrencyState() {}
2815ASTUnit::ConcurrencyState::~ConcurrencyState() {}
2816void ASTUnit::ConcurrencyState::start() {}
2817void ASTUnit::ConcurrencyState::finish() {}
2818
2819#endif
2820