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/ASTConsumer.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/StmtVisitor.h"
19#include "clang/AST/TypeOrdering.h"
20#include "clang/Basic/Diagnostic.h"
21#include "clang/Basic/TargetInfo.h"
22#include "clang/Basic/TargetOptions.h"
23#include "clang/Basic/VirtualFileSystem.h"
24#include "clang/Frontend/CompilerInstance.h"
25#include "clang/Frontend/FrontendActions.h"
26#include "clang/Frontend/FrontendDiagnostic.h"
27#include "clang/Frontend/FrontendOptions.h"
28#include "clang/Frontend/MultiplexConsumer.h"
29#include "clang/Frontend/Utils.h"
30#include "clang/Lex/HeaderSearch.h"
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Lex/PreprocessorOptions.h"
33#include "clang/Sema/Sema.h"
34#include "clang/Serialization/ASTReader.h"
35#include "clang/Serialization/ASTWriter.h"
36#include "llvm/ADT/ArrayRef.h"
37#include "llvm/ADT/StringExtras.h"
38#include "llvm/ADT/StringSet.h"
39#include "llvm/Support/CrashRecoveryContext.h"
40#include "llvm/Support/Host.h"
41#include "llvm/Support/MemoryBuffer.h"
42#include "llvm/Support/Mutex.h"
43#include "llvm/Support/MutexGuard.h"
44#include "llvm/Support/Path.h"
45#include "llvm/Support/Timer.h"
46#include "llvm/Support/raw_ostream.h"
47#include <atomic>
48#include <cstdio>
49#include <cstdlib>
50using namespace clang;
51
52using llvm::TimeRecord;
53
54namespace {
55  class SimpleTimer {
56    bool WantTiming;
57    TimeRecord Start;
58    std::string Output;
59
60  public:
61    explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
62      if (WantTiming)
63        Start = TimeRecord::getCurrentTime();
64    }
65
66    void setOutput(const Twine &Output) {
67      if (WantTiming)
68        this->Output = Output.str();
69    }
70
71    ~SimpleTimer() {
72      if (WantTiming) {
73        TimeRecord Elapsed = TimeRecord::getCurrentTime();
74        Elapsed -= Start;
75        llvm::errs() << Output << ':';
76        Elapsed.print(Elapsed, llvm::errs());
77        llvm::errs() << '\n';
78      }
79    }
80  };
81
82  struct OnDiskData {
83    /// \brief The file in which the precompiled preamble is stored.
84    std::string PreambleFile;
85
86    /// \brief Temporary files that should be removed when the ASTUnit is
87    /// destroyed.
88    SmallVector<std::string, 4> TemporaryFiles;
89
90    /// \brief Erase temporary files.
91    void CleanTemporaryFiles();
92
93    /// \brief Erase the preamble file.
94    void CleanPreambleFile();
95
96    /// \brief Erase temporary files and the preamble file.
97    void Cleanup();
98  };
99}
100
101static llvm::sys::SmartMutex<false> &getOnDiskMutex() {
102  static llvm::sys::SmartMutex<false> M(/* recursive = */ true);
103  return M;
104}
105
106static void cleanupOnDiskMapAtExit();
107
108typedef llvm::DenseMap<const ASTUnit *,
109                       std::unique_ptr<OnDiskData>> OnDiskDataMap;
110static OnDiskDataMap &getOnDiskDataMap() {
111  static OnDiskDataMap M;
112  static bool hasRegisteredAtExit = false;
113  if (!hasRegisteredAtExit) {
114    hasRegisteredAtExit = true;
115    atexit(cleanupOnDiskMapAtExit);
116  }
117  return M;
118}
119
120static void cleanupOnDiskMapAtExit() {
121  // Use the mutex because there can be an alive thread destroying an ASTUnit.
122  llvm::MutexGuard Guard(getOnDiskMutex());
123  for (const auto &I : getOnDiskDataMap()) {
124    // We don't worry about freeing the memory associated with OnDiskDataMap.
125    // All we care about is erasing stale files.
126    I.second->Cleanup();
127  }
128}
129
130static OnDiskData &getOnDiskData(const ASTUnit *AU) {
131  // We require the mutex since we are modifying the structure of the
132  // DenseMap.
133  llvm::MutexGuard Guard(getOnDiskMutex());
134  OnDiskDataMap &M = getOnDiskDataMap();
135  auto &D = M[AU];
136  if (!D)
137    D = llvm::make_unique<OnDiskData>();
138  return *D;
139}
140
141static void erasePreambleFile(const ASTUnit *AU) {
142  getOnDiskData(AU).CleanPreambleFile();
143}
144
145static void removeOnDiskEntry(const ASTUnit *AU) {
146  // We require the mutex since we are modifying the structure of the
147  // DenseMap.
148  llvm::MutexGuard Guard(getOnDiskMutex());
149  OnDiskDataMap &M = getOnDiskDataMap();
150  OnDiskDataMap::iterator I = M.find(AU);
151  if (I != M.end()) {
152    I->second->Cleanup();
153    M.erase(I);
154  }
155}
156
157static void setPreambleFile(const ASTUnit *AU, 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 (StringRef File : TemporaryFiles)
167    llvm::sys::fs::remove(File);
168  TemporaryFiles.clear();
169}
170
171void OnDiskData::CleanPreambleFile() {
172  if (!PreambleFile.empty()) {
173    llvm::sys::fs::remove(PreambleFile);
174    PreambleFile.clear();
175  }
176}
177
178void OnDiskData::Cleanup() {
179  CleanTemporaryFiles();
180  CleanPreambleFile();
181}
182
183struct ASTUnit::ASTWriterData {
184  SmallString<128> Buffer;
185  llvm::BitstreamWriter Stream;
186  ASTWriter Writer;
187
188  ASTWriterData() : Stream(Buffer), Writer(Stream) { }
189};
190
191void ASTUnit::clearFileLevelDecls() {
192  llvm::DeleteContainerSeconds(FileDecls);
193}
194
195void ASTUnit::CleanTemporaryFiles() {
196  getOnDiskData(this).CleanTemporaryFiles();
197}
198
199void ASTUnit::addTemporaryFile(StringRef TempFile) {
200  getOnDiskData(this).TemporaryFiles.push_back(TempFile);
201}
202
203/// \brief After failing to build a precompiled preamble (due to
204/// errors in the source that occurs in the preamble), the number of
205/// reparses during which we'll skip even trying to precompile the
206/// preamble.
207const unsigned DefaultPreambleRebuildInterval = 5;
208
209/// \brief Tracks the number of ASTUnit objects that are currently active.
210///
211/// Used for debugging purposes only.
212static std::atomic<unsigned> ActiveASTUnitObjects;
213
214ASTUnit::ASTUnit(bool _MainFileIsAST)
215  : Reader(nullptr), HadModuleLoaderFatalFailure(false),
216    OnlyLocalDecls(false), CaptureDiagnostics(false),
217    MainFileIsAST(_MainFileIsAST),
218    TUKind(TU_Complete), WantTiming(getenv("LIBCLANG_TIMING")),
219    OwnsRemappedFileBuffers(true),
220    NumStoredDiagnosticsFromDriver(0),
221    PreambleRebuildCounter(0),
222    NumWarningsInPreamble(0),
223    ShouldCacheCodeCompletionResults(false),
224    IncludeBriefCommentsInCodeCompletion(false), UserFilesAreVolatile(false),
225    CompletionCacheTopLevelHashValue(0),
226    PreambleTopLevelHashValue(0),
227    CurrentTopLevelHashValue(0),
228    UnsafeToFree(false) {
229  if (getenv("LIBCLANG_OBJTRACKING"))
230    fprintf(stderr, "+++ %u translation units\n", ++ActiveASTUnitObjects);
231}
232
233ASTUnit::~ASTUnit() {
234  // If we loaded from an AST file, balance out the BeginSourceFile call.
235  if (MainFileIsAST && getDiagnostics().getClient()) {
236    getDiagnostics().getClient()->EndSourceFile();
237  }
238
239  clearFileLevelDecls();
240
241  // Clean up the temporary files and the preamble file.
242  removeOnDiskEntry(this);
243
244  // Free the buffers associated with remapped files. We are required to
245  // perform this operation here because we explicitly request that the
246  // compiler instance *not* free these buffers for each invocation of the
247  // parser.
248  if (Invocation.get() && OwnsRemappedFileBuffers) {
249    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
250    for (const auto &RB : PPOpts.RemappedFileBuffers)
251      delete RB.second;
252  }
253
254  ClearCachedCompletionResults();
255
256  if (getenv("LIBCLANG_OBJTRACKING"))
257    fprintf(stderr, "--- %u translation units\n", --ActiveASTUnitObjects);
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(const 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.CPlusPlus11)
305        IsNestedNameSpecifier = true;
306    } else if (const 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  CodeCompletionTUInfo CCTUInfo(CachedCompletionAllocator);
351  TheSema->GatherGlobalCodeCompletions(*CachedCompletionAllocator,
352                                       CCTUInfo, Results);
353
354  // Translate global code completions into cached completions.
355  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
356
357  for (Result &R : Results) {
358    switch (R.Kind) {
359    case Result::RK_Declaration: {
360      bool IsNestedNameSpecifier = false;
361      CachedCodeCompletionResult CachedResult;
362      CachedResult.Completion = R.CreateCodeCompletionString(
363          *TheSema, *CachedCompletionAllocator, CCTUInfo,
364          IncludeBriefCommentsInCodeCompletion);
365      CachedResult.ShowInContexts = getDeclShowContexts(
366          R.Declaration, Ctx->getLangOpts(), IsNestedNameSpecifier);
367      CachedResult.Priority = R.Priority;
368      CachedResult.Kind = R.CursorKind;
369      CachedResult.Availability = R.Availability;
370
371      // Keep track of the type of this completion in an ASTContext-agnostic
372      // way.
373      QualType UsageType = getDeclUsageType(*Ctx, R.Declaration);
374      if (UsageType.isNull()) {
375        CachedResult.TypeClass = STC_Void;
376        CachedResult.Type = 0;
377      } else {
378        CanQualType CanUsageType
379          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
380        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
381
382        // Determine whether we have already seen this type. If so, we save
383        // ourselves the work of formatting the type string by using the
384        // temporary, CanQualType-based hash table to find the associated value.
385        unsigned &TypeValue = CompletionTypes[CanUsageType];
386        if (TypeValue == 0) {
387          TypeValue = CompletionTypes.size();
388          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
389            = TypeValue;
390        }
391
392        CachedResult.Type = TypeValue;
393      }
394
395      CachedCompletionResults.push_back(CachedResult);
396
397      /// Handle nested-name-specifiers in C++.
398      if (TheSema->Context.getLangOpts().CPlusPlus && IsNestedNameSpecifier &&
399          !R.StartsNestedNameSpecifier) {
400        // The contexts in which a nested-name-specifier can appear in C++.
401        uint64_t NNSContexts
402          = (1LL << CodeCompletionContext::CCC_TopLevel)
403          | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
404          | (1LL << CodeCompletionContext::CCC_ClassStructUnion)
405          | (1LL << CodeCompletionContext::CCC_Statement)
406          | (1LL << CodeCompletionContext::CCC_Expression)
407          | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
408          | (1LL << CodeCompletionContext::CCC_EnumTag)
409          | (1LL << CodeCompletionContext::CCC_UnionTag)
410          | (1LL << CodeCompletionContext::CCC_ClassOrStructTag)
411          | (1LL << CodeCompletionContext::CCC_Type)
412          | (1LL << CodeCompletionContext::CCC_PotentiallyQualifiedName)
413          | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression);
414
415        if (isa<NamespaceDecl>(R.Declaration) ||
416            isa<NamespaceAliasDecl>(R.Declaration))
417          NNSContexts |= (1LL << CodeCompletionContext::CCC_Namespace);
418
419        if (unsigned RemainingContexts
420                                = NNSContexts & ~CachedResult.ShowInContexts) {
421          // If there any contexts where this completion can be a
422          // nested-name-specifier but isn't already an option, create a
423          // nested-name-specifier completion.
424          R.StartsNestedNameSpecifier = true;
425          CachedResult.Completion = R.CreateCodeCompletionString(
426              *TheSema, *CachedCompletionAllocator, CCTUInfo,
427              IncludeBriefCommentsInCodeCompletion);
428          CachedResult.ShowInContexts = RemainingContexts;
429          CachedResult.Priority = CCP_NestedNameSpecifier;
430          CachedResult.TypeClass = STC_Void;
431          CachedResult.Type = 0;
432          CachedCompletionResults.push_back(CachedResult);
433        }
434      }
435      break;
436    }
437
438    case Result::RK_Keyword:
439    case Result::RK_Pattern:
440      // Ignore keywords and patterns; we don't care, since they are so
441      // easily regenerated.
442      break;
443
444    case Result::RK_Macro: {
445      CachedCodeCompletionResult CachedResult;
446      CachedResult.Completion = R.CreateCodeCompletionString(
447          *TheSema, *CachedCompletionAllocator, CCTUInfo,
448          IncludeBriefCommentsInCodeCompletion);
449      CachedResult.ShowInContexts
450        = (1LL << CodeCompletionContext::CCC_TopLevel)
451        | (1LL << CodeCompletionContext::CCC_ObjCInterface)
452        | (1LL << CodeCompletionContext::CCC_ObjCImplementation)
453        | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
454        | (1LL << CodeCompletionContext::CCC_ClassStructUnion)
455        | (1LL << CodeCompletionContext::CCC_Statement)
456        | (1LL << CodeCompletionContext::CCC_Expression)
457        | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
458        | (1LL << CodeCompletionContext::CCC_MacroNameUse)
459        | (1LL << CodeCompletionContext::CCC_PreprocessorExpression)
460        | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression)
461        | (1LL << CodeCompletionContext::CCC_OtherWithMacros);
462
463      CachedResult.Priority = R.Priority;
464      CachedResult.Kind = R.CursorKind;
465      CachedResult.Availability = R.Availability;
466      CachedResult.TypeClass = STC_Void;
467      CachedResult.Type = 0;
468      CachedCompletionResults.push_back(CachedResult);
469      break;
470    }
471    }
472  }
473
474  // Save the current top-level hash value.
475  CompletionCacheTopLevelHashValue = CurrentTopLevelHashValue;
476}
477
478void ASTUnit::ClearCachedCompletionResults() {
479  CachedCompletionResults.clear();
480  CachedCompletionTypes.clear();
481  CachedCompletionAllocator = nullptr;
482}
483
484namespace {
485
486/// \brief Gathers information from ASTReader that will be used to initialize
487/// a Preprocessor.
488class ASTInfoCollector : public ASTReaderListener {
489  Preprocessor &PP;
490  ASTContext &Context;
491  LangOptions &LangOpt;
492  std::shared_ptr<TargetOptions> &TargetOpts;
493  IntrusiveRefCntPtr<TargetInfo> &Target;
494  unsigned &Counter;
495
496  bool InitializedLanguage;
497public:
498  ASTInfoCollector(Preprocessor &PP, ASTContext &Context, LangOptions &LangOpt,
499                   std::shared_ptr<TargetOptions> &TargetOpts,
500                   IntrusiveRefCntPtr<TargetInfo> &Target, unsigned &Counter)
501      : PP(PP), Context(Context), LangOpt(LangOpt), TargetOpts(TargetOpts),
502        Target(Target), Counter(Counter), InitializedLanguage(false) {}
503
504  bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
505                           bool AllowCompatibleDifferences) override {
506    if (InitializedLanguage)
507      return false;
508
509    LangOpt = LangOpts;
510    InitializedLanguage = true;
511
512    updated();
513    return false;
514  }
515
516  bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
517                         bool AllowCompatibleDifferences) override {
518    // If we've already initialized the target, don't do it again.
519    if (Target)
520      return false;
521
522    this->TargetOpts = std::make_shared<TargetOptions>(TargetOpts);
523    Target =
524        TargetInfo::CreateTargetInfo(PP.getDiagnostics(), this->TargetOpts);
525
526    updated();
527    return false;
528  }
529
530  void ReadCounter(const serialization::ModuleFile &M,
531                   unsigned Value) override {
532    Counter = Value;
533  }
534
535private:
536  void updated() {
537    if (!Target || !InitializedLanguage)
538      return;
539
540    // Inform the target of the language options.
541    //
542    // FIXME: We shouldn't need to do this, the target should be immutable once
543    // created. This complexity should be lifted elsewhere.
544    Target->adjust(LangOpt);
545
546    // Initialize the preprocessor.
547    PP.Initialize(*Target);
548
549    // Initialize the ASTContext
550    Context.InitBuiltinTypes(*Target);
551
552    // We didn't have access to the comment options when the ASTContext was
553    // constructed, so register them now.
554    Context.getCommentCommandTraits().registerCommentOptions(
555        LangOpt.CommentOpts);
556  }
557};
558
559  /// \brief Diagnostic consumer that saves each diagnostic it is given.
560class StoredDiagnosticConsumer : public DiagnosticConsumer {
561  SmallVectorImpl<StoredDiagnostic> &StoredDiags;
562  SourceManager *SourceMgr;
563
564public:
565  explicit StoredDiagnosticConsumer(
566                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
567    : StoredDiags(StoredDiags), SourceMgr(nullptr) {}
568
569  void BeginSourceFile(const LangOptions &LangOpts,
570                       const Preprocessor *PP = nullptr) override {
571    if (PP)
572      SourceMgr = &PP->getSourceManager();
573  }
574
575  void HandleDiagnostic(DiagnosticsEngine::Level Level,
576                        const Diagnostic &Info) override;
577};
578
579/// \brief RAII object that optionally captures diagnostics, if
580/// there is no diagnostic client to capture them already.
581class CaptureDroppedDiagnostics {
582  DiagnosticsEngine &Diags;
583  StoredDiagnosticConsumer Client;
584  DiagnosticConsumer *PreviousClient;
585  std::unique_ptr<DiagnosticConsumer> OwningPreviousClient;
586
587public:
588  CaptureDroppedDiagnostics(bool RequestCapture, DiagnosticsEngine &Diags,
589                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
590    : Diags(Diags), Client(StoredDiags), PreviousClient(nullptr)
591  {
592    if (RequestCapture || Diags.getClient() == nullptr) {
593      OwningPreviousClient = Diags.takeClient();
594      PreviousClient = Diags.getClient();
595      Diags.setClient(&Client, false);
596    }
597  }
598
599  ~CaptureDroppedDiagnostics() {
600    if (Diags.getClient() == &Client)
601      Diags.setClient(PreviousClient, !!OwningPreviousClient.release());
602  }
603};
604
605} // anonymous namespace
606
607void StoredDiagnosticConsumer::HandleDiagnostic(DiagnosticsEngine::Level Level,
608                                              const Diagnostic &Info) {
609  // Default implementation (Warnings/errors count).
610  DiagnosticConsumer::HandleDiagnostic(Level, Info);
611
612  // Only record the diagnostic if it's part of the source manager we know
613  // about. This effectively drops diagnostics from modules we're building.
614  // FIXME: In the long run, ee don't want to drop source managers from modules.
615  if (!Info.hasSourceManager() || &Info.getSourceManager() == SourceMgr)
616    StoredDiags.push_back(StoredDiagnostic(Level, Info));
617}
618
619ASTMutationListener *ASTUnit::getASTMutationListener() {
620  if (WriterData)
621    return &WriterData->Writer;
622  return nullptr;
623}
624
625ASTDeserializationListener *ASTUnit::getDeserializationListener() {
626  if (WriterData)
627    return &WriterData->Writer;
628  return nullptr;
629}
630
631std::unique_ptr<llvm::MemoryBuffer>
632ASTUnit::getBufferForFile(StringRef Filename, std::string *ErrorStr) {
633  assert(FileMgr);
634  auto Buffer = FileMgr->getBufferForFile(Filename);
635  if (Buffer)
636    return std::move(*Buffer);
637  if (ErrorStr)
638    *ErrorStr = Buffer.getError().message();
639  return nullptr;
640}
641
642/// \brief Configure the diagnostics object for use with ASTUnit.
643void ASTUnit::ConfigureDiags(IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
644                             ASTUnit &AST, bool CaptureDiagnostics) {
645  assert(Diags.get() && "no DiagnosticsEngine was provided");
646  if (CaptureDiagnostics)
647    Diags->setClient(new StoredDiagnosticConsumer(AST.StoredDiagnostics));
648}
649
650std::unique_ptr<ASTUnit> ASTUnit::LoadFromASTFile(
651    const std::string &Filename, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
652    const FileSystemOptions &FileSystemOpts, bool OnlyLocalDecls,
653    ArrayRef<RemappedFile> RemappedFiles, bool CaptureDiagnostics,
654    bool AllowPCHWithCompilerErrors, bool UserFilesAreVolatile) {
655  std::unique_ptr<ASTUnit> AST(new ASTUnit(true));
656
657  // Recover resources if we crash before exiting this method.
658  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
659    ASTUnitCleanup(AST.get());
660  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
661    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
662    DiagCleanup(Diags.get());
663
664  ConfigureDiags(Diags, *AST, CaptureDiagnostics);
665
666  AST->OnlyLocalDecls = OnlyLocalDecls;
667  AST->CaptureDiagnostics = CaptureDiagnostics;
668  AST->Diagnostics = Diags;
669  IntrusiveRefCntPtr<vfs::FileSystem> VFS = vfs::getRealFileSystem();
670  AST->FileMgr = new FileManager(FileSystemOpts, VFS);
671  AST->UserFilesAreVolatile = UserFilesAreVolatile;
672  AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
673                                     AST->getFileManager(),
674                                     UserFilesAreVolatile);
675  AST->HSOpts = new HeaderSearchOptions();
676
677  AST->HeaderInfo.reset(new HeaderSearch(AST->HSOpts,
678                                         AST->getSourceManager(),
679                                         AST->getDiagnostics(),
680                                         AST->ASTFileLangOpts,
681                                         /*Target=*/nullptr));
682
683  PreprocessorOptions *PPOpts = new PreprocessorOptions();
684
685  for (const auto &RemappedFile : RemappedFiles)
686    PPOpts->addRemappedFile(RemappedFile.first, RemappedFile.second);
687
688  // Gather Info for preprocessor construction later on.
689
690  HeaderSearch &HeaderInfo = *AST->HeaderInfo;
691  unsigned Counter;
692
693  AST->PP =
694      new Preprocessor(PPOpts, AST->getDiagnostics(), AST->ASTFileLangOpts,
695                       AST->getSourceManager(), HeaderInfo, *AST,
696                       /*IILookup=*/nullptr,
697                       /*OwnsHeaderSearch=*/false);
698  Preprocessor &PP = *AST->PP;
699
700  AST->Ctx = new ASTContext(AST->ASTFileLangOpts, AST->getSourceManager(),
701                            PP.getIdentifierTable(), PP.getSelectorTable(),
702                            PP.getBuiltinInfo());
703  ASTContext &Context = *AST->Ctx;
704
705  bool disableValid = false;
706  if (::getenv("LIBCLANG_DISABLE_PCH_VALIDATION"))
707    disableValid = true;
708  AST->Reader = new ASTReader(PP, Context,
709                             /*isysroot=*/"",
710                             /*DisableValidation=*/disableValid,
711                             AllowPCHWithCompilerErrors);
712
713  AST->Reader->setListener(llvm::make_unique<ASTInfoCollector>(
714      *AST->PP, Context, AST->ASTFileLangOpts, AST->TargetOpts, AST->Target,
715      Counter));
716
717  // Attach the AST reader to the AST context as an external AST
718  // source, so that declarations will be deserialized from the
719  // AST file as needed.
720  // We need the external source to be set up before we read the AST, because
721  // eagerly-deserialized declarations may use it.
722  Context.setExternalSource(AST->Reader);
723
724  switch (AST->Reader->ReadAST(Filename, serialization::MK_MainFile,
725                          SourceLocation(), ASTReader::ARR_None)) {
726  case ASTReader::Success:
727    break;
728
729  case ASTReader::Failure:
730  case ASTReader::Missing:
731  case ASTReader::OutOfDate:
732  case ASTReader::VersionMismatch:
733  case ASTReader::ConfigurationMismatch:
734  case ASTReader::HadErrors:
735    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
736    return nullptr;
737  }
738
739  AST->OriginalSourceFile = AST->Reader->getOriginalSourceFile();
740
741  PP.setCounterValue(Counter);
742
743  // Create an AST consumer, even though it isn't used.
744  AST->Consumer.reset(new ASTConsumer);
745
746  // Create a semantic analysis object and tell the AST reader about it.
747  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
748  AST->TheSema->Initialize();
749  AST->Reader->InitializeSema(*AST->TheSema);
750
751  // Tell the diagnostic client that we have started a source file.
752  AST->getDiagnostics().getClient()->BeginSourceFile(Context.getLangOpts(),&PP);
753
754  return AST;
755}
756
757namespace {
758
759/// \brief Preprocessor callback class that updates a hash value with the names
760/// of all macros that have been defined by the translation unit.
761class MacroDefinitionTrackerPPCallbacks : public PPCallbacks {
762  unsigned &Hash;
763
764public:
765  explicit MacroDefinitionTrackerPPCallbacks(unsigned &Hash) : Hash(Hash) { }
766
767  void MacroDefined(const Token &MacroNameTok,
768                    const MacroDirective *MD) override {
769    Hash = llvm::HashString(MacroNameTok.getIdentifierInfo()->getName(), Hash);
770  }
771};
772
773/// \brief Add the given declaration to the hash of all top-level entities.
774void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
775  if (!D)
776    return;
777
778  DeclContext *DC = D->getDeclContext();
779  if (!DC)
780    return;
781
782  if (!(DC->isTranslationUnit() || DC->getLookupParent()->isTranslationUnit()))
783    return;
784
785  if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
786    if (EnumDecl *EnumD = dyn_cast<EnumDecl>(D)) {
787      // For an unscoped enum include the enumerators in the hash since they
788      // enter the top-level namespace.
789      if (!EnumD->isScoped()) {
790        for (const auto *EI : EnumD->enumerators()) {
791          if (EI->getIdentifier())
792            Hash = llvm::HashString(EI->getIdentifier()->getName(), Hash);
793        }
794      }
795    }
796
797    if (ND->getIdentifier())
798      Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
799    else if (DeclarationName Name = ND->getDeclName()) {
800      std::string NameStr = Name.getAsString();
801      Hash = llvm::HashString(NameStr, Hash);
802    }
803    return;
804  }
805
806  if (ImportDecl *ImportD = dyn_cast<ImportDecl>(D)) {
807    if (Module *Mod = ImportD->getImportedModule()) {
808      std::string ModName = Mod->getFullModuleName();
809      Hash = llvm::HashString(ModName, Hash);
810    }
811    return;
812  }
813}
814
815class TopLevelDeclTrackerConsumer : public ASTConsumer {
816  ASTUnit &Unit;
817  unsigned &Hash;
818
819public:
820  TopLevelDeclTrackerConsumer(ASTUnit &_Unit, unsigned &Hash)
821    : Unit(_Unit), Hash(Hash) {
822    Hash = 0;
823  }
824
825  void handleTopLevelDecl(Decl *D) {
826    if (!D)
827      return;
828
829    // FIXME: Currently ObjC method declarations are incorrectly being
830    // reported as top-level declarations, even though their DeclContext
831    // is the containing ObjC @interface/@implementation.  This is a
832    // fundamental problem in the parser right now.
833    if (isa<ObjCMethodDecl>(D))
834      return;
835
836    AddTopLevelDeclarationToHash(D, Hash);
837    Unit.addTopLevelDecl(D);
838
839    handleFileLevelDecl(D);
840  }
841
842  void handleFileLevelDecl(Decl *D) {
843    Unit.addFileLevelDecl(D);
844    if (NamespaceDecl *NSD = dyn_cast<NamespaceDecl>(D)) {
845      for (auto *I : NSD->decls())
846        handleFileLevelDecl(I);
847    }
848  }
849
850  bool HandleTopLevelDecl(DeclGroupRef D) override {
851    for (Decl *TopLevelDecl : D)
852      handleTopLevelDecl(TopLevelDecl);
853    return true;
854  }
855
856  // We're not interested in "interesting" decls.
857  void HandleInterestingDecl(DeclGroupRef) override {}
858
859  void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override {
860    for (Decl *TopLevelDecl : D)
861      handleTopLevelDecl(TopLevelDecl);
862  }
863
864  ASTMutationListener *GetASTMutationListener() override {
865    return Unit.getASTMutationListener();
866  }
867
868  ASTDeserializationListener *GetASTDeserializationListener() override {
869    return Unit.getDeserializationListener();
870  }
871};
872
873class TopLevelDeclTrackerAction : public ASTFrontendAction {
874public:
875  ASTUnit &Unit;
876
877  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
878                                                 StringRef InFile) override {
879    CI.getPreprocessor().addPPCallbacks(
880        llvm::make_unique<MacroDefinitionTrackerPPCallbacks>(
881                                           Unit.getCurrentTopLevelHashValue()));
882    return llvm::make_unique<TopLevelDeclTrackerConsumer>(
883        Unit, Unit.getCurrentTopLevelHashValue());
884  }
885
886public:
887  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
888
889  bool hasCodeCompletionSupport() const override { return false; }
890  TranslationUnitKind getTranslationUnitKind() override {
891    return Unit.getTranslationUnitKind();
892  }
893};
894
895class PrecompilePreambleAction : public ASTFrontendAction {
896  ASTUnit &Unit;
897  bool HasEmittedPreamblePCH;
898
899public:
900  explicit PrecompilePreambleAction(ASTUnit &Unit)
901      : Unit(Unit), HasEmittedPreamblePCH(false) {}
902
903  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
904                                                 StringRef InFile) override;
905  bool hasEmittedPreamblePCH() const { return HasEmittedPreamblePCH; }
906  void setHasEmittedPreamblePCH() { HasEmittedPreamblePCH = true; }
907  bool shouldEraseOutputFiles() override { return !hasEmittedPreamblePCH(); }
908
909  bool hasCodeCompletionSupport() const override { return false; }
910  bool hasASTFileSupport() const override { return false; }
911  TranslationUnitKind getTranslationUnitKind() override { return TU_Prefix; }
912};
913
914class PrecompilePreambleConsumer : public PCHGenerator {
915  ASTUnit &Unit;
916  unsigned &Hash;
917  std::vector<Decl *> TopLevelDecls;
918  PrecompilePreambleAction *Action;
919
920public:
921  PrecompilePreambleConsumer(ASTUnit &Unit, PrecompilePreambleAction *Action,
922                             const Preprocessor &PP, StringRef isysroot,
923                             raw_ostream *Out)
924    : PCHGenerator(PP, "", nullptr, isysroot, Out, /*AllowASTWithErrors=*/true),
925      Unit(Unit), Hash(Unit.getCurrentTopLevelHashValue()), Action(Action) {
926    Hash = 0;
927  }
928
929  bool HandleTopLevelDecl(DeclGroupRef DG) override {
930    for (Decl *D : DG) {
931      // FIXME: Currently ObjC method declarations are incorrectly being
932      // reported as top-level declarations, even though their DeclContext
933      // is the containing ObjC @interface/@implementation.  This is a
934      // fundamental problem in the parser right now.
935      if (isa<ObjCMethodDecl>(D))
936        continue;
937      AddTopLevelDeclarationToHash(D, Hash);
938      TopLevelDecls.push_back(D);
939    }
940    return true;
941  }
942
943  void HandleTranslationUnit(ASTContext &Ctx) override {
944    PCHGenerator::HandleTranslationUnit(Ctx);
945    if (hasEmittedPCH()) {
946      // Translate the top-level declarations we captured during
947      // parsing into declaration IDs in the precompiled
948      // preamble. This will allow us to deserialize those top-level
949      // declarations when requested.
950      for (Decl *D : TopLevelDecls) {
951        // Invalid top-level decls may not have been serialized.
952        if (D->isInvalidDecl())
953          continue;
954        Unit.addTopLevelDeclFromPreamble(getWriter().getDeclID(D));
955      }
956
957      Action->setHasEmittedPreamblePCH();
958    }
959  }
960};
961
962}
963
964std::unique_ptr<ASTConsumer>
965PrecompilePreambleAction::CreateASTConsumer(CompilerInstance &CI,
966                                            StringRef InFile) {
967  std::string Sysroot;
968  std::string OutputFile;
969  raw_ostream *OS = GeneratePCHAction::ComputeASTConsumerArguments(
970      CI, InFile, Sysroot, OutputFile);
971  if (!OS)
972    return nullptr;
973
974  if (!CI.getFrontendOpts().RelocatablePCH)
975    Sysroot.clear();
976
977  CI.getPreprocessor().addPPCallbacks(
978      llvm::make_unique<MacroDefinitionTrackerPPCallbacks>(
979                                           Unit.getCurrentTopLevelHashValue()));
980  return llvm::make_unique<PrecompilePreambleConsumer>(
981      Unit, this, CI.getPreprocessor(), Sysroot, OS);
982}
983
984static bool isNonDriverDiag(const StoredDiagnostic &StoredDiag) {
985  return StoredDiag.getLocation().isValid();
986}
987
988static void
989checkAndRemoveNonDriverDiags(SmallVectorImpl<StoredDiagnostic> &StoredDiags) {
990  // Get rid of stored diagnostics except the ones from the driver which do not
991  // have a source location.
992  StoredDiags.erase(
993      std::remove_if(StoredDiags.begin(), StoredDiags.end(), isNonDriverDiag),
994      StoredDiags.end());
995}
996
997static void checkAndSanitizeDiags(SmallVectorImpl<StoredDiagnostic> &
998                                                              StoredDiagnostics,
999                                  SourceManager &SM) {
1000  // The stored diagnostic has the old source manager in it; update
1001  // the locations to refer into the new source manager. Since we've
1002  // been careful to make sure that the source manager's state
1003  // before and after are identical, so that we can reuse the source
1004  // location itself.
1005  for (StoredDiagnostic &SD : StoredDiagnostics) {
1006    if (SD.getLocation().isValid()) {
1007      FullSourceLoc Loc(SD.getLocation(), SM);
1008      SD.setLocation(Loc);
1009    }
1010  }
1011}
1012
1013/// Parse the source file into a translation unit using the given compiler
1014/// invocation, replacing the current translation unit.
1015///
1016/// \returns True if a failure occurred that causes the ASTUnit not to
1017/// contain any translation-unit information, false otherwise.
1018bool ASTUnit::Parse(std::unique_ptr<llvm::MemoryBuffer> OverrideMainBuffer) {
1019  SavedMainFileBuffer.reset();
1020
1021  if (!Invocation)
1022    return true;
1023
1024  // Create the compiler instance to use for building the AST.
1025  std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
1026
1027  // Recover resources if we crash before exiting this method.
1028  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1029    CICleanup(Clang.get());
1030
1031  IntrusiveRefCntPtr<CompilerInvocation>
1032    CCInvocation(new CompilerInvocation(*Invocation));
1033
1034  Clang->setInvocation(CCInvocation.get());
1035  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].getFile();
1036
1037  // Set up diagnostics, capturing any diagnostics that would
1038  // otherwise be dropped.
1039  Clang->setDiagnostics(&getDiagnostics());
1040
1041  // Create the target instance.
1042  Clang->setTarget(TargetInfo::CreateTargetInfo(
1043      Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
1044  if (!Clang->hasTarget())
1045    return true;
1046
1047  // Inform the target of the language options.
1048  //
1049  // FIXME: We shouldn't need to do this, the target should be immutable once
1050  // created. This complexity should be lifted elsewhere.
1051  Clang->getTarget().adjust(Clang->getLangOpts());
1052
1053  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1054         "Invocation must have exactly one source file!");
1055  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
1056         "FIXME: AST inputs not yet supported here!");
1057  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
1058         "IR inputs not support here!");
1059
1060  // Configure the various subsystems.
1061  LangOpts = Clang->getInvocation().LangOpts;
1062  FileSystemOpts = Clang->getFileSystemOpts();
1063  IntrusiveRefCntPtr<vfs::FileSystem> VFS =
1064      createVFSFromCompilerInvocation(Clang->getInvocation(), getDiagnostics());
1065  if (!VFS)
1066    return true;
1067  FileMgr = new FileManager(FileSystemOpts, VFS);
1068  SourceMgr = new SourceManager(getDiagnostics(), *FileMgr,
1069                                UserFilesAreVolatile);
1070  TheSema.reset();
1071  Ctx = nullptr;
1072  PP = nullptr;
1073  Reader = nullptr;
1074
1075  // Clear out old caches and data.
1076  TopLevelDecls.clear();
1077  clearFileLevelDecls();
1078  CleanTemporaryFiles();
1079
1080  if (!OverrideMainBuffer) {
1081    checkAndRemoveNonDriverDiags(StoredDiagnostics);
1082    TopLevelDeclsInPreamble.clear();
1083  }
1084
1085  // Create a file manager object to provide access to and cache the filesystem.
1086  Clang->setFileManager(&getFileManager());
1087
1088  // Create the source manager.
1089  Clang->setSourceManager(&getSourceManager());
1090
1091  // If the main file has been overridden due to the use of a preamble,
1092  // make that override happen and introduce the preamble.
1093  PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
1094  if (OverrideMainBuffer) {
1095    PreprocessorOpts.addRemappedFile(OriginalSourceFile,
1096                                     OverrideMainBuffer.get());
1097    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1098    PreprocessorOpts.PrecompiledPreambleBytes.second
1099                                                    = PreambleEndsAtStartOfLine;
1100    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
1101    PreprocessorOpts.DisablePCHValidation = true;
1102
1103    // The stored diagnostic has the old source manager in it; update
1104    // the locations to refer into the new source manager. Since we've
1105    // been careful to make sure that the source manager's state
1106    // before and after are identical, so that we can reuse the source
1107    // location itself.
1108    checkAndSanitizeDiags(StoredDiagnostics, getSourceManager());
1109
1110    // Keep track of the override buffer;
1111    SavedMainFileBuffer = std::move(OverrideMainBuffer);
1112  }
1113
1114  std::unique_ptr<TopLevelDeclTrackerAction> Act(
1115      new TopLevelDeclTrackerAction(*this));
1116
1117  // Recover resources if we crash before exiting this method.
1118  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1119    ActCleanup(Act.get());
1120
1121  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))
1122    goto error;
1123
1124  if (SavedMainFileBuffer) {
1125    std::string ModName = getPreambleFile(this);
1126    TranslateStoredDiagnostics(getFileManager(), getSourceManager(),
1127                               PreambleDiagnostics, StoredDiagnostics);
1128  }
1129
1130  if (!Act->Execute())
1131    goto error;
1132
1133  transferASTDataFromCompilerInstance(*Clang);
1134
1135  Act->EndSourceFile();
1136
1137  FailedParseDiagnostics.clear();
1138
1139  return false;
1140
1141error:
1142  // Remove the overridden buffer we used for the preamble.
1143  SavedMainFileBuffer = nullptr;
1144
1145  // Keep the ownership of the data in the ASTUnit because the client may
1146  // want to see the diagnostics.
1147  transferASTDataFromCompilerInstance(*Clang);
1148  FailedParseDiagnostics.swap(StoredDiagnostics);
1149  StoredDiagnostics.clear();
1150  NumStoredDiagnosticsFromDriver = 0;
1151  return true;
1152}
1153
1154/// \brief Simple function to retrieve a path for a preamble precompiled header.
1155static std::string GetPreamblePCHPath() {
1156  // FIXME: This is a hack so that we can override the preamble file during
1157  // crash-recovery testing, which is the only case where the preamble files
1158  // are not necessarily cleaned up.
1159  const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
1160  if (TmpFile)
1161    return TmpFile;
1162
1163  SmallString<128> Path;
1164  llvm::sys::fs::createTemporaryFile("preamble", "pch", Path);
1165
1166  return Path.str();
1167}
1168
1169/// \brief Compute the preamble for the main file, providing the source buffer
1170/// that corresponds to the main file along with a pair (bytes, start-of-line)
1171/// that describes the preamble.
1172ASTUnit::ComputedPreamble
1173ASTUnit::ComputePreamble(CompilerInvocation &Invocation, unsigned MaxLines) {
1174  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
1175  PreprocessorOptions &PreprocessorOpts = Invocation.getPreprocessorOpts();
1176
1177  // Try to determine if the main file has been remapped, either from the
1178  // command line (to another file) or directly through the compiler invocation
1179  // (to a memory buffer).
1180  llvm::MemoryBuffer *Buffer = nullptr;
1181  std::unique_ptr<llvm::MemoryBuffer> BufferOwner;
1182  std::string MainFilePath(FrontendOpts.Inputs[0].getFile());
1183  llvm::sys::fs::UniqueID MainFileID;
1184  if (!llvm::sys::fs::getUniqueID(MainFilePath, MainFileID)) {
1185    // Check whether there is a file-file remapping of the main file
1186    for (const auto &RF : PreprocessorOpts.RemappedFiles) {
1187      std::string MPath(RF.first);
1188      llvm::sys::fs::UniqueID MID;
1189      if (!llvm::sys::fs::getUniqueID(MPath, MID)) {
1190        if (MainFileID == MID) {
1191          // We found a remapping. Try to load the resulting, remapped source.
1192          BufferOwner = getBufferForFile(RF.second);
1193          if (!BufferOwner)
1194            return ComputedPreamble(nullptr, nullptr, 0, true);
1195        }
1196      }
1197    }
1198
1199    // Check whether there is a file-buffer remapping. It supercedes the
1200    // file-file remapping.
1201    for (const auto &RB : PreprocessorOpts.RemappedFileBuffers) {
1202      std::string MPath(RB.first);
1203      llvm::sys::fs::UniqueID MID;
1204      if (!llvm::sys::fs::getUniqueID(MPath, MID)) {
1205        if (MainFileID == MID) {
1206          // We found a remapping.
1207          BufferOwner.reset();
1208          Buffer = const_cast<llvm::MemoryBuffer *>(RB.second);
1209        }
1210      }
1211    }
1212  }
1213
1214  // If the main source file was not remapped, load it now.
1215  if (!Buffer && !BufferOwner) {
1216    BufferOwner = getBufferForFile(FrontendOpts.Inputs[0].getFile());
1217    if (!BufferOwner)
1218      return ComputedPreamble(nullptr, nullptr, 0, true);
1219  }
1220
1221  if (!Buffer)
1222    Buffer = BufferOwner.get();
1223  auto Pre = Lexer::ComputePreamble(Buffer->getBuffer(),
1224                                    *Invocation.getLangOpts(), MaxLines);
1225  return ComputedPreamble(Buffer, std::move(BufferOwner), Pre.first,
1226                          Pre.second);
1227}
1228
1229ASTUnit::PreambleFileHash
1230ASTUnit::PreambleFileHash::createForFile(off_t Size, time_t ModTime) {
1231  PreambleFileHash Result;
1232  Result.Size = Size;
1233  Result.ModTime = ModTime;
1234  memset(Result.MD5, 0, sizeof(Result.MD5));
1235  return Result;
1236}
1237
1238ASTUnit::PreambleFileHash ASTUnit::PreambleFileHash::createForMemoryBuffer(
1239    const llvm::MemoryBuffer *Buffer) {
1240  PreambleFileHash Result;
1241  Result.Size = Buffer->getBufferSize();
1242  Result.ModTime = 0;
1243
1244  llvm::MD5 MD5Ctx;
1245  MD5Ctx.update(Buffer->getBuffer().data());
1246  MD5Ctx.final(Result.MD5);
1247
1248  return Result;
1249}
1250
1251namespace clang {
1252bool operator==(const ASTUnit::PreambleFileHash &LHS,
1253                const ASTUnit::PreambleFileHash &RHS) {
1254  return LHS.Size == RHS.Size && LHS.ModTime == RHS.ModTime &&
1255         memcmp(LHS.MD5, RHS.MD5, sizeof(LHS.MD5)) == 0;
1256}
1257} // namespace clang
1258
1259static std::pair<unsigned, unsigned>
1260makeStandaloneRange(CharSourceRange Range, const SourceManager &SM,
1261                    const LangOptions &LangOpts) {
1262  CharSourceRange FileRange = Lexer::makeFileCharRange(Range, SM, LangOpts);
1263  unsigned Offset = SM.getFileOffset(FileRange.getBegin());
1264  unsigned EndOffset = SM.getFileOffset(FileRange.getEnd());
1265  return std::make_pair(Offset, EndOffset);
1266}
1267
1268static ASTUnit::StandaloneFixIt makeStandaloneFixIt(const SourceManager &SM,
1269                                                    const LangOptions &LangOpts,
1270                                                    const FixItHint &InFix) {
1271  ASTUnit::StandaloneFixIt OutFix;
1272  OutFix.RemoveRange = makeStandaloneRange(InFix.RemoveRange, SM, LangOpts);
1273  OutFix.InsertFromRange = makeStandaloneRange(InFix.InsertFromRange, SM,
1274                                               LangOpts);
1275  OutFix.CodeToInsert = InFix.CodeToInsert;
1276  OutFix.BeforePreviousInsertions = InFix.BeforePreviousInsertions;
1277  return OutFix;
1278}
1279
1280static ASTUnit::StandaloneDiagnostic
1281makeStandaloneDiagnostic(const LangOptions &LangOpts,
1282                         const StoredDiagnostic &InDiag) {
1283  ASTUnit::StandaloneDiagnostic OutDiag;
1284  OutDiag.ID = InDiag.getID();
1285  OutDiag.Level = InDiag.getLevel();
1286  OutDiag.Message = InDiag.getMessage();
1287  OutDiag.LocOffset = 0;
1288  if (InDiag.getLocation().isInvalid())
1289    return OutDiag;
1290  const SourceManager &SM = InDiag.getLocation().getManager();
1291  SourceLocation FileLoc = SM.getFileLoc(InDiag.getLocation());
1292  OutDiag.Filename = SM.getFilename(FileLoc);
1293  if (OutDiag.Filename.empty())
1294    return OutDiag;
1295  OutDiag.LocOffset = SM.getFileOffset(FileLoc);
1296  for (const CharSourceRange &Range : InDiag.getRanges())
1297    OutDiag.Ranges.push_back(makeStandaloneRange(Range, SM, LangOpts));
1298  for (const FixItHint &FixIt : InDiag.getFixIts())
1299    OutDiag.FixIts.push_back(makeStandaloneFixIt(SM, LangOpts, FixIt));
1300
1301  return OutDiag;
1302}
1303
1304/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
1305/// the source file.
1306///
1307/// This routine will compute the preamble of the main source file. If a
1308/// non-trivial preamble is found, it will precompile that preamble into a
1309/// precompiled header so that the precompiled preamble can be used to reduce
1310/// reparsing time. If a precompiled preamble has already been constructed,
1311/// this routine will determine if it is still valid and, if so, avoid
1312/// rebuilding the precompiled preamble.
1313///
1314/// \param AllowRebuild When true (the default), this routine is
1315/// allowed to rebuild the precompiled preamble if it is found to be
1316/// out-of-date.
1317///
1318/// \param MaxLines When non-zero, the maximum number of lines that
1319/// can occur within the preamble.
1320///
1321/// \returns If the precompiled preamble can be used, returns a newly-allocated
1322/// buffer that should be used in place of the main file when doing so.
1323/// Otherwise, returns a NULL pointer.
1324std::unique_ptr<llvm::MemoryBuffer>
1325ASTUnit::getMainBufferWithPrecompiledPreamble(
1326    const CompilerInvocation &PreambleInvocationIn, bool AllowRebuild,
1327    unsigned MaxLines) {
1328
1329  IntrusiveRefCntPtr<CompilerInvocation>
1330    PreambleInvocation(new CompilerInvocation(PreambleInvocationIn));
1331  FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();
1332  PreprocessorOptions &PreprocessorOpts
1333    = PreambleInvocation->getPreprocessorOpts();
1334
1335  ComputedPreamble NewPreamble = ComputePreamble(*PreambleInvocation, MaxLines);
1336
1337  if (!NewPreamble.Size) {
1338    // We couldn't find a preamble in the main source. Clear out the current
1339    // preamble, if we have one. It's obviously no good any more.
1340    Preamble.clear();
1341    erasePreambleFile(this);
1342
1343    // The next time we actually see a preamble, precompile it.
1344    PreambleRebuildCounter = 1;
1345    return nullptr;
1346  }
1347
1348  if (!Preamble.empty()) {
1349    // We've previously computed a preamble. Check whether we have the same
1350    // preamble now that we did before, and that there's enough space in
1351    // the main-file buffer within the precompiled preamble to fit the
1352    // new main file.
1353    if (Preamble.size() == NewPreamble.Size &&
1354        PreambleEndsAtStartOfLine == NewPreamble.PreambleEndsAtStartOfLine &&
1355        memcmp(Preamble.getBufferStart(), NewPreamble.Buffer->getBufferStart(),
1356               NewPreamble.Size) == 0) {
1357      // The preamble has not changed. We may be able to re-use the precompiled
1358      // preamble.
1359
1360      // Check that none of the files used by the preamble have changed.
1361      bool AnyFileChanged = false;
1362
1363      // First, make a record of those files that have been overridden via
1364      // remapping or unsaved_files.
1365      llvm::StringMap<PreambleFileHash> OverriddenFiles;
1366      for (const auto &R : PreprocessorOpts.RemappedFiles) {
1367        if (AnyFileChanged)
1368          break;
1369
1370        vfs::Status Status;
1371        if (FileMgr->getNoncachedStatValue(R.second, Status)) {
1372          // If we can't stat the file we're remapping to, assume that something
1373          // horrible happened.
1374          AnyFileChanged = true;
1375          break;
1376        }
1377
1378        OverriddenFiles[R.first] = PreambleFileHash::createForFile(
1379            Status.getSize(), Status.getLastModificationTime().toEpochTime());
1380      }
1381
1382      for (const auto &RB : PreprocessorOpts.RemappedFileBuffers) {
1383        if (AnyFileChanged)
1384          break;
1385        OverriddenFiles[RB.first] =
1386            PreambleFileHash::createForMemoryBuffer(RB.second);
1387      }
1388
1389      // Check whether anything has changed.
1390      for (llvm::StringMap<PreambleFileHash>::iterator
1391             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1392           !AnyFileChanged && F != FEnd;
1393           ++F) {
1394        llvm::StringMap<PreambleFileHash>::iterator Overridden
1395          = OverriddenFiles.find(F->first());
1396        if (Overridden != OverriddenFiles.end()) {
1397          // This file was remapped; check whether the newly-mapped file
1398          // matches up with the previous mapping.
1399          if (Overridden->second != F->second)
1400            AnyFileChanged = true;
1401          continue;
1402        }
1403
1404        // The file was not remapped; check whether it has changed on disk.
1405        vfs::Status Status;
1406        if (FileMgr->getNoncachedStatValue(F->first(), Status)) {
1407          // If we can't stat the file, assume that something horrible happened.
1408          AnyFileChanged = true;
1409        } else if (Status.getSize() != uint64_t(F->second.Size) ||
1410                   Status.getLastModificationTime().toEpochTime() !=
1411                       uint64_t(F->second.ModTime))
1412          AnyFileChanged = true;
1413      }
1414
1415      if (!AnyFileChanged) {
1416        // Okay! We can re-use the precompiled preamble.
1417
1418        // Set the state of the diagnostic object to mimic its state
1419        // after parsing the preamble.
1420        getDiagnostics().Reset();
1421        ProcessWarningOptions(getDiagnostics(),
1422                              PreambleInvocation->getDiagnosticOpts());
1423        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1424
1425        return llvm::MemoryBuffer::getMemBufferCopy(
1426            NewPreamble.Buffer->getBuffer(), FrontendOpts.Inputs[0].getFile());
1427      }
1428    }
1429
1430    // If we aren't allowed to rebuild the precompiled preamble, just
1431    // return now.
1432    if (!AllowRebuild)
1433      return nullptr;
1434
1435    // We can't reuse the previously-computed preamble. Build a new one.
1436    Preamble.clear();
1437    PreambleDiagnostics.clear();
1438    erasePreambleFile(this);
1439    PreambleRebuildCounter = 1;
1440  } else if (!AllowRebuild) {
1441    // We aren't allowed to rebuild the precompiled preamble; just
1442    // return now.
1443    return nullptr;
1444  }
1445
1446  // If the preamble rebuild counter > 1, it's because we previously
1447  // failed to build a preamble and we're not yet ready to try
1448  // again. Decrement the counter and return a failure.
1449  if (PreambleRebuildCounter > 1) {
1450    --PreambleRebuildCounter;
1451    return nullptr;
1452  }
1453
1454  // Create a temporary file for the precompiled preamble. In rare
1455  // circumstances, this can fail.
1456  std::string PreamblePCHPath = GetPreamblePCHPath();
1457  if (PreamblePCHPath.empty()) {
1458    // Try again next time.
1459    PreambleRebuildCounter = 1;
1460    return nullptr;
1461  }
1462
1463  // We did not previously compute a preamble, or it can't be reused anyway.
1464  SimpleTimer PreambleTimer(WantTiming);
1465  PreambleTimer.setOutput("Precompiling preamble");
1466
1467  // Save the preamble text for later; we'll need to compare against it for
1468  // subsequent reparses.
1469  StringRef MainFilename = FrontendOpts.Inputs[0].getFile();
1470  Preamble.assign(FileMgr->getFile(MainFilename),
1471                  NewPreamble.Buffer->getBufferStart(),
1472                  NewPreamble.Buffer->getBufferStart() + NewPreamble.Size);
1473  PreambleEndsAtStartOfLine = NewPreamble.PreambleEndsAtStartOfLine;
1474
1475  PreambleBuffer = llvm::MemoryBuffer::getMemBufferCopy(
1476      NewPreamble.Buffer->getBuffer().slice(0, Preamble.size()), MainFilename);
1477
1478  // Remap the main source file to the preamble buffer.
1479  StringRef MainFilePath = FrontendOpts.Inputs[0].getFile();
1480  PreprocessorOpts.addRemappedFile(MainFilePath, PreambleBuffer.get());
1481
1482  // Tell the compiler invocation to generate a temporary precompiled header.
1483  FrontendOpts.ProgramAction = frontend::GeneratePCH;
1484  // FIXME: Generate the precompiled header into memory?
1485  FrontendOpts.OutputFile = PreamblePCHPath;
1486  PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1487  PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1488
1489  // Create the compiler instance to use for building the precompiled preamble.
1490  std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
1491
1492  // Recover resources if we crash before exiting this method.
1493  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1494    CICleanup(Clang.get());
1495
1496  Clang->setInvocation(&*PreambleInvocation);
1497  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].getFile();
1498
1499  // Set up diagnostics, capturing all of the diagnostics produced.
1500  Clang->setDiagnostics(&getDiagnostics());
1501
1502  // Create the target instance.
1503  Clang->setTarget(TargetInfo::CreateTargetInfo(
1504      Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
1505  if (!Clang->hasTarget()) {
1506    llvm::sys::fs::remove(FrontendOpts.OutputFile);
1507    Preamble.clear();
1508    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1509    PreprocessorOpts.RemappedFileBuffers.pop_back();
1510    return nullptr;
1511  }
1512
1513  // Inform the target of the language options.
1514  //
1515  // FIXME: We shouldn't need to do this, the target should be immutable once
1516  // created. This complexity should be lifted elsewhere.
1517  Clang->getTarget().adjust(Clang->getLangOpts());
1518
1519  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1520         "Invocation must have exactly one source file!");
1521  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
1522         "FIXME: AST inputs not yet supported here!");
1523  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
1524         "IR inputs not support here!");
1525
1526  // Clear out old caches and data.
1527  getDiagnostics().Reset();
1528  ProcessWarningOptions(getDiagnostics(), Clang->getDiagnosticOpts());
1529  checkAndRemoveNonDriverDiags(StoredDiagnostics);
1530  TopLevelDecls.clear();
1531  TopLevelDeclsInPreamble.clear();
1532  PreambleDiagnostics.clear();
1533
1534  IntrusiveRefCntPtr<vfs::FileSystem> VFS =
1535      createVFSFromCompilerInvocation(Clang->getInvocation(), getDiagnostics());
1536  if (!VFS)
1537    return nullptr;
1538
1539  // Create a file manager object to provide access to and cache the filesystem.
1540  Clang->setFileManager(new FileManager(Clang->getFileSystemOpts(), VFS));
1541
1542  // Create the source manager.
1543  Clang->setSourceManager(new SourceManager(getDiagnostics(),
1544                                            Clang->getFileManager()));
1545
1546  auto PreambleDepCollector = std::make_shared<DependencyCollector>();
1547  Clang->addDependencyCollector(PreambleDepCollector);
1548
1549  std::unique_ptr<PrecompilePreambleAction> Act;
1550  Act.reset(new PrecompilePreambleAction(*this));
1551  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
1552    llvm::sys::fs::remove(FrontendOpts.OutputFile);
1553    Preamble.clear();
1554    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1555    PreprocessorOpts.RemappedFileBuffers.pop_back();
1556    return nullptr;
1557  }
1558
1559  Act->Execute();
1560
1561  // Transfer any diagnostics generated when parsing the preamble into the set
1562  // of preamble diagnostics.
1563  for (stored_diag_iterator I = stored_diag_afterDriver_begin(),
1564                            E = stored_diag_end();
1565       I != E; ++I)
1566    PreambleDiagnostics.push_back(
1567        makeStandaloneDiagnostic(Clang->getLangOpts(), *I));
1568
1569  Act->EndSourceFile();
1570
1571  checkAndRemoveNonDriverDiags(StoredDiagnostics);
1572
1573  if (!Act->hasEmittedPreamblePCH()) {
1574    // The preamble PCH failed (e.g. there was a module loading fatal error),
1575    // so no precompiled header was generated. Forget that we even tried.
1576    // FIXME: Should we leave a note for ourselves to try again?
1577    llvm::sys::fs::remove(FrontendOpts.OutputFile);
1578    Preamble.clear();
1579    TopLevelDeclsInPreamble.clear();
1580    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1581    PreprocessorOpts.RemappedFileBuffers.pop_back();
1582    return nullptr;
1583  }
1584
1585  // Keep track of the preamble we precompiled.
1586  setPreambleFile(this, FrontendOpts.OutputFile);
1587  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1588
1589  // Keep track of all of the files that the source manager knows about,
1590  // so we can verify whether they have changed or not.
1591  FilesInPreamble.clear();
1592  SourceManager &SourceMgr = Clang->getSourceManager();
1593  for (auto &Filename : PreambleDepCollector->getDependencies()) {
1594    const FileEntry *File = Clang->getFileManager().getFile(Filename);
1595    if (!File || File == SourceMgr.getFileEntryForID(SourceMgr.getMainFileID()))
1596      continue;
1597    if (time_t ModTime = File->getModificationTime()) {
1598      FilesInPreamble[File->getName()] = PreambleFileHash::createForFile(
1599          File->getSize(), ModTime);
1600    } else {
1601      llvm::MemoryBuffer *Buffer = SourceMgr.getMemoryBufferForFile(File);
1602      FilesInPreamble[File->getName()] =
1603          PreambleFileHash::createForMemoryBuffer(Buffer);
1604    }
1605  }
1606
1607  PreambleRebuildCounter = 1;
1608  PreprocessorOpts.RemappedFileBuffers.pop_back();
1609
1610  // If the hash of top-level entities differs from the hash of the top-level
1611  // entities the last time we rebuilt the preamble, clear out the completion
1612  // cache.
1613  if (CurrentTopLevelHashValue != PreambleTopLevelHashValue) {
1614    CompletionCacheTopLevelHashValue = 0;
1615    PreambleTopLevelHashValue = CurrentTopLevelHashValue;
1616  }
1617
1618  return llvm::MemoryBuffer::getMemBufferCopy(NewPreamble.Buffer->getBuffer(),
1619                                              MainFilename);
1620}
1621
1622void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1623  std::vector<Decl *> Resolved;
1624  Resolved.reserve(TopLevelDeclsInPreamble.size());
1625  ExternalASTSource &Source = *getASTContext().getExternalSource();
1626  for (serialization::DeclID TopLevelDecl : TopLevelDeclsInPreamble) {
1627    // Resolve the declaration ID to an actual declaration, possibly
1628    // deserializing the declaration in the process.
1629    if (Decl *D = Source.GetExternalDecl(TopLevelDecl))
1630      Resolved.push_back(D);
1631  }
1632  TopLevelDeclsInPreamble.clear();
1633  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1634}
1635
1636void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
1637  // Steal the created target, context, and preprocessor if they have been
1638  // created.
1639  assert(CI.hasInvocation() && "missing invocation");
1640  LangOpts = CI.getInvocation().LangOpts;
1641  TheSema = CI.takeSema();
1642  Consumer = CI.takeASTConsumer();
1643  if (CI.hasASTContext())
1644    Ctx = &CI.getASTContext();
1645  if (CI.hasPreprocessor())
1646    PP = &CI.getPreprocessor();
1647  CI.setSourceManager(nullptr);
1648  CI.setFileManager(nullptr);
1649  if (CI.hasTarget())
1650    Target = &CI.getTarget();
1651  Reader = CI.getModuleManager();
1652  HadModuleLoaderFatalFailure = CI.hadModuleLoaderFatalFailure();
1653}
1654
1655StringRef ASTUnit::getMainFileName() const {
1656  if (Invocation && !Invocation->getFrontendOpts().Inputs.empty()) {
1657    const FrontendInputFile &Input = Invocation->getFrontendOpts().Inputs[0];
1658    if (Input.isFile())
1659      return Input.getFile();
1660    else
1661      return Input.getBuffer()->getBufferIdentifier();
1662  }
1663
1664  if (SourceMgr) {
1665    if (const FileEntry *
1666          FE = SourceMgr->getFileEntryForID(SourceMgr->getMainFileID()))
1667      return FE->getName();
1668  }
1669
1670  return StringRef();
1671}
1672
1673StringRef ASTUnit::getASTFileName() const {
1674  if (!isMainFileAST())
1675    return StringRef();
1676
1677  serialization::ModuleFile &
1678    Mod = Reader->getModuleManager().getPrimaryModule();
1679  return Mod.FileName;
1680}
1681
1682ASTUnit *ASTUnit::create(CompilerInvocation *CI,
1683                         IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1684                         bool CaptureDiagnostics,
1685                         bool UserFilesAreVolatile) {
1686  std::unique_ptr<ASTUnit> AST;
1687  AST.reset(new ASTUnit(false));
1688  ConfigureDiags(Diags, *AST, CaptureDiagnostics);
1689  AST->Diagnostics = Diags;
1690  AST->Invocation = CI;
1691  AST->FileSystemOpts = CI->getFileSystemOpts();
1692  IntrusiveRefCntPtr<vfs::FileSystem> VFS =
1693      createVFSFromCompilerInvocation(*CI, *Diags);
1694  if (!VFS)
1695    return nullptr;
1696  AST->FileMgr = new FileManager(AST->FileSystemOpts, VFS);
1697  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1698  AST->SourceMgr = new SourceManager(AST->getDiagnostics(), *AST->FileMgr,
1699                                     UserFilesAreVolatile);
1700
1701  return AST.release();
1702}
1703
1704ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(
1705    CompilerInvocation *CI, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1706    ASTFrontendAction *Action, ASTUnit *Unit, bool Persistent,
1707    StringRef ResourceFilesPath, bool OnlyLocalDecls, bool CaptureDiagnostics,
1708    bool PrecompilePreamble, bool CacheCodeCompletionResults,
1709    bool IncludeBriefCommentsInCodeCompletion, bool UserFilesAreVolatile,
1710    std::unique_ptr<ASTUnit> *ErrAST) {
1711  assert(CI && "A CompilerInvocation is required");
1712
1713  std::unique_ptr<ASTUnit> OwnAST;
1714  ASTUnit *AST = Unit;
1715  if (!AST) {
1716    // Create the AST unit.
1717    OwnAST.reset(create(CI, Diags, CaptureDiagnostics, UserFilesAreVolatile));
1718    AST = OwnAST.get();
1719    if (!AST)
1720      return nullptr;
1721  }
1722
1723  if (!ResourceFilesPath.empty()) {
1724    // Override the resources path.
1725    CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1726  }
1727  AST->OnlyLocalDecls = OnlyLocalDecls;
1728  AST->CaptureDiagnostics = CaptureDiagnostics;
1729  if (PrecompilePreamble)
1730    AST->PreambleRebuildCounter = 2;
1731  AST->TUKind = Action ? Action->getTranslationUnitKind() : TU_Complete;
1732  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1733  AST->IncludeBriefCommentsInCodeCompletion
1734    = IncludeBriefCommentsInCodeCompletion;
1735
1736  // Recover resources if we crash before exiting this method.
1737  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1738    ASTUnitCleanup(OwnAST.get());
1739  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1740    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1741    DiagCleanup(Diags.get());
1742
1743  // We'll manage file buffers ourselves.
1744  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1745  CI->getFrontendOpts().DisableFree = false;
1746  ProcessWarningOptions(AST->getDiagnostics(), CI->getDiagnosticOpts());
1747
1748  // Create the compiler instance to use for building the AST.
1749  std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
1750
1751  // Recover resources if we crash before exiting this method.
1752  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1753    CICleanup(Clang.get());
1754
1755  Clang->setInvocation(CI);
1756  AST->OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].getFile();
1757
1758  // Set up diagnostics, capturing any diagnostics that would
1759  // otherwise be dropped.
1760  Clang->setDiagnostics(&AST->getDiagnostics());
1761
1762  // Create the target instance.
1763  Clang->setTarget(TargetInfo::CreateTargetInfo(
1764      Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
1765  if (!Clang->hasTarget())
1766    return nullptr;
1767
1768  // Inform the target of the language options.
1769  //
1770  // FIXME: We shouldn't need to do this, the target should be immutable once
1771  // created. This complexity should be lifted elsewhere.
1772  Clang->getTarget().adjust(Clang->getLangOpts());
1773
1774  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1775         "Invocation must have exactly one source file!");
1776  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
1777         "FIXME: AST inputs not yet supported here!");
1778  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
1779         "IR inputs not supported here!");
1780
1781  // Configure the various subsystems.
1782  AST->TheSema.reset();
1783  AST->Ctx = nullptr;
1784  AST->PP = nullptr;
1785  AST->Reader = nullptr;
1786
1787  // Create a file manager object to provide access to and cache the filesystem.
1788  Clang->setFileManager(&AST->getFileManager());
1789
1790  // Create the source manager.
1791  Clang->setSourceManager(&AST->getSourceManager());
1792
1793  ASTFrontendAction *Act = Action;
1794
1795  std::unique_ptr<TopLevelDeclTrackerAction> TrackerAct;
1796  if (!Act) {
1797    TrackerAct.reset(new TopLevelDeclTrackerAction(*AST));
1798    Act = TrackerAct.get();
1799  }
1800
1801  // Recover resources if we crash before exiting this method.
1802  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1803    ActCleanup(TrackerAct.get());
1804
1805  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
1806    AST->transferASTDataFromCompilerInstance(*Clang);
1807    if (OwnAST && ErrAST)
1808      ErrAST->swap(OwnAST);
1809
1810    return nullptr;
1811  }
1812
1813  if (Persistent && !TrackerAct) {
1814    Clang->getPreprocessor().addPPCallbacks(
1815        llvm::make_unique<MacroDefinitionTrackerPPCallbacks>(
1816                                           AST->getCurrentTopLevelHashValue()));
1817    std::vector<std::unique_ptr<ASTConsumer>> Consumers;
1818    if (Clang->hasASTConsumer())
1819      Consumers.push_back(Clang->takeASTConsumer());
1820    Consumers.push_back(llvm::make_unique<TopLevelDeclTrackerConsumer>(
1821        *AST, AST->getCurrentTopLevelHashValue()));
1822    Clang->setASTConsumer(
1823        llvm::make_unique<MultiplexConsumer>(std::move(Consumers)));
1824  }
1825  if (!Act->Execute()) {
1826    AST->transferASTDataFromCompilerInstance(*Clang);
1827    if (OwnAST && ErrAST)
1828      ErrAST->swap(OwnAST);
1829
1830    return nullptr;
1831  }
1832
1833  // Steal the created target, context, and preprocessor.
1834  AST->transferASTDataFromCompilerInstance(*Clang);
1835
1836  Act->EndSourceFile();
1837
1838  if (OwnAST)
1839    return OwnAST.release();
1840  else
1841    return AST;
1842}
1843
1844bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
1845  if (!Invocation)
1846    return true;
1847
1848  // We'll manage file buffers ourselves.
1849  Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1850  Invocation->getFrontendOpts().DisableFree = false;
1851  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1852
1853  std::unique_ptr<llvm::MemoryBuffer> OverrideMainBuffer;
1854  if (PrecompilePreamble) {
1855    PreambleRebuildCounter = 2;
1856    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
1857  }
1858
1859  SimpleTimer ParsingTimer(WantTiming);
1860  ParsingTimer.setOutput("Parsing " + getMainFileName());
1861
1862  // Recover resources if we crash before exiting this method.
1863  llvm::CrashRecoveryContextCleanupRegistrar<llvm::MemoryBuffer>
1864    MemBufferCleanup(OverrideMainBuffer.get());
1865
1866  return Parse(std::move(OverrideMainBuffer));
1867}
1868
1869std::unique_ptr<ASTUnit> ASTUnit::LoadFromCompilerInvocation(
1870    CompilerInvocation *CI, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1871    bool OnlyLocalDecls, bool CaptureDiagnostics, bool PrecompilePreamble,
1872    TranslationUnitKind TUKind, bool CacheCodeCompletionResults,
1873    bool IncludeBriefCommentsInCodeCompletion, bool UserFilesAreVolatile) {
1874  // Create the AST unit.
1875  std::unique_ptr<ASTUnit> AST(new ASTUnit(false));
1876  ConfigureDiags(Diags, *AST, CaptureDiagnostics);
1877  AST->Diagnostics = Diags;
1878  AST->OnlyLocalDecls = OnlyLocalDecls;
1879  AST->CaptureDiagnostics = CaptureDiagnostics;
1880  AST->TUKind = TUKind;
1881  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1882  AST->IncludeBriefCommentsInCodeCompletion
1883    = IncludeBriefCommentsInCodeCompletion;
1884  AST->Invocation = CI;
1885  AST->FileSystemOpts = CI->getFileSystemOpts();
1886  IntrusiveRefCntPtr<vfs::FileSystem> VFS =
1887      createVFSFromCompilerInvocation(*CI, *Diags);
1888  if (!VFS)
1889    return nullptr;
1890  AST->FileMgr = new FileManager(AST->FileSystemOpts, VFS);
1891  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1892
1893  // Recover resources if we crash before exiting this method.
1894  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1895    ASTUnitCleanup(AST.get());
1896  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1897    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1898    DiagCleanup(Diags.get());
1899
1900  if (AST->LoadFromCompilerInvocation(PrecompilePreamble))
1901    return nullptr;
1902  return AST;
1903}
1904
1905ASTUnit *ASTUnit::LoadFromCommandLine(
1906    const char **ArgBegin, const char **ArgEnd,
1907    IntrusiveRefCntPtr<DiagnosticsEngine> Diags, StringRef ResourceFilesPath,
1908    bool OnlyLocalDecls, bool CaptureDiagnostics,
1909    ArrayRef<RemappedFile> RemappedFiles, bool RemappedFilesKeepOriginalName,
1910    bool PrecompilePreamble, TranslationUnitKind TUKind,
1911    bool CacheCodeCompletionResults, bool IncludeBriefCommentsInCodeCompletion,
1912    bool AllowPCHWithCompilerErrors, bool SkipFunctionBodies,
1913    bool UserFilesAreVolatile, bool ForSerialization,
1914    std::unique_ptr<ASTUnit> *ErrAST) {
1915  assert(Diags.get() && "no DiagnosticsEngine was provided");
1916
1917  SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
1918
1919  IntrusiveRefCntPtr<CompilerInvocation> CI;
1920
1921  {
1922
1923    CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags,
1924                                      StoredDiagnostics);
1925
1926    CI = clang::createInvocationFromCommandLine(
1927                                           llvm::makeArrayRef(ArgBegin, ArgEnd),
1928                                           Diags);
1929    if (!CI)
1930      return nullptr;
1931  }
1932
1933  // Override any files that need remapping
1934  for (const auto &RemappedFile : RemappedFiles) {
1935    CI->getPreprocessorOpts().addRemappedFile(RemappedFile.first,
1936                                              RemappedFile.second);
1937  }
1938  PreprocessorOptions &PPOpts = CI->getPreprocessorOpts();
1939  PPOpts.RemappedFilesKeepOriginalName = RemappedFilesKeepOriginalName;
1940  PPOpts.AllowPCHWithCompilerErrors = AllowPCHWithCompilerErrors;
1941
1942  // Override the resources path.
1943  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1944
1945  CI->getFrontendOpts().SkipFunctionBodies = SkipFunctionBodies;
1946
1947  // Create the AST unit.
1948  std::unique_ptr<ASTUnit> AST;
1949  AST.reset(new ASTUnit(false));
1950  ConfigureDiags(Diags, *AST, CaptureDiagnostics);
1951  AST->Diagnostics = Diags;
1952  AST->FileSystemOpts = CI->getFileSystemOpts();
1953  IntrusiveRefCntPtr<vfs::FileSystem> VFS =
1954      createVFSFromCompilerInvocation(*CI, *Diags);
1955  if (!VFS)
1956    return nullptr;
1957  AST->FileMgr = new FileManager(AST->FileSystemOpts, VFS);
1958  AST->OnlyLocalDecls = OnlyLocalDecls;
1959  AST->CaptureDiagnostics = CaptureDiagnostics;
1960  AST->TUKind = TUKind;
1961  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1962  AST->IncludeBriefCommentsInCodeCompletion
1963    = IncludeBriefCommentsInCodeCompletion;
1964  AST->UserFilesAreVolatile = UserFilesAreVolatile;
1965  AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
1966  AST->StoredDiagnostics.swap(StoredDiagnostics);
1967  AST->Invocation = CI;
1968  if (ForSerialization)
1969    AST->WriterData.reset(new ASTWriterData());
1970  // Zero out now to ease cleanup during crash recovery.
1971  CI = nullptr;
1972  Diags = nullptr;
1973
1974  // Recover resources if we crash before exiting this method.
1975  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1976    ASTUnitCleanup(AST.get());
1977
1978  if (AST->LoadFromCompilerInvocation(PrecompilePreamble)) {
1979    // Some error occurred, if caller wants to examine diagnostics, pass it the
1980    // ASTUnit.
1981    if (ErrAST) {
1982      AST->StoredDiagnostics.swap(AST->FailedParseDiagnostics);
1983      ErrAST->swap(AST);
1984    }
1985    return nullptr;
1986  }
1987
1988  return AST.release();
1989}
1990
1991bool ASTUnit::Reparse(ArrayRef<RemappedFile> RemappedFiles) {
1992  if (!Invocation)
1993    return true;
1994
1995  clearFileLevelDecls();
1996
1997  SimpleTimer ParsingTimer(WantTiming);
1998  ParsingTimer.setOutput("Reparsing " + getMainFileName());
1999
2000  // Remap files.
2001  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
2002  for (const auto &RB : PPOpts.RemappedFileBuffers)
2003    delete RB.second;
2004
2005  Invocation->getPreprocessorOpts().clearRemappedFiles();
2006  for (const auto &RemappedFile : RemappedFiles) {
2007    Invocation->getPreprocessorOpts().addRemappedFile(RemappedFile.first,
2008                                                      RemappedFile.second);
2009  }
2010
2011  // If we have a preamble file lying around, or if we might try to
2012  // build a precompiled preamble, do so now.
2013  std::unique_ptr<llvm::MemoryBuffer> OverrideMainBuffer;
2014  if (!getPreambleFile(this).empty() || PreambleRebuildCounter > 0)
2015    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
2016
2017  // Clear out the diagnostics state.
2018  getDiagnostics().Reset();
2019  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
2020  if (OverrideMainBuffer)
2021    getDiagnostics().setNumWarnings(NumWarningsInPreamble);
2022
2023  // Parse the sources
2024  bool Result = Parse(std::move(OverrideMainBuffer));
2025
2026  // If we're caching global code-completion results, and the top-level
2027  // declarations have changed, clear out the code-completion cache.
2028  if (!Result && ShouldCacheCodeCompletionResults &&
2029      CurrentTopLevelHashValue != CompletionCacheTopLevelHashValue)
2030    CacheCodeCompletionResults();
2031
2032  // We now need to clear out the completion info related to this translation
2033  // unit; it'll be recreated if necessary.
2034  CCTUInfo.reset();
2035
2036  return Result;
2037}
2038
2039//----------------------------------------------------------------------------//
2040// Code completion
2041//----------------------------------------------------------------------------//
2042
2043namespace {
2044  /// \brief Code completion consumer that combines the cached code-completion
2045  /// results from an ASTUnit with the code-completion results provided to it,
2046  /// then passes the result on to
2047  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
2048    uint64_t NormalContexts;
2049    ASTUnit &AST;
2050    CodeCompleteConsumer &Next;
2051
2052  public:
2053    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
2054                                  const CodeCompleteOptions &CodeCompleteOpts)
2055      : CodeCompleteConsumer(CodeCompleteOpts, Next.isOutputBinary()),
2056        AST(AST), Next(Next)
2057    {
2058      // Compute the set of contexts in which we will look when we don't have
2059      // any information about the specific context.
2060      NormalContexts
2061        = (1LL << CodeCompletionContext::CCC_TopLevel)
2062        | (1LL << CodeCompletionContext::CCC_ObjCInterface)
2063        | (1LL << CodeCompletionContext::CCC_ObjCImplementation)
2064        | (1LL << CodeCompletionContext::CCC_ObjCIvarList)
2065        | (1LL << CodeCompletionContext::CCC_Statement)
2066        | (1LL << CodeCompletionContext::CCC_Expression)
2067        | (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver)
2068        | (1LL << CodeCompletionContext::CCC_DotMemberAccess)
2069        | (1LL << CodeCompletionContext::CCC_ArrowMemberAccess)
2070        | (1LL << CodeCompletionContext::CCC_ObjCPropertyAccess)
2071        | (1LL << CodeCompletionContext::CCC_ObjCProtocolName)
2072        | (1LL << CodeCompletionContext::CCC_ParenthesizedExpression)
2073        | (1LL << CodeCompletionContext::CCC_Recovery);
2074
2075      if (AST.getASTContext().getLangOpts().CPlusPlus)
2076        NormalContexts |= (1LL << CodeCompletionContext::CCC_EnumTag)
2077                       |  (1LL << CodeCompletionContext::CCC_UnionTag)
2078                       |  (1LL << CodeCompletionContext::CCC_ClassOrStructTag);
2079    }
2080
2081    void ProcessCodeCompleteResults(Sema &S, CodeCompletionContext Context,
2082                                    CodeCompletionResult *Results,
2083                                    unsigned NumResults) override;
2084
2085    void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
2086                                   OverloadCandidate *Candidates,
2087                                   unsigned NumCandidates) override {
2088      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
2089    }
2090
2091    CodeCompletionAllocator &getAllocator() override {
2092      return Next.getAllocator();
2093    }
2094
2095    CodeCompletionTUInfo &getCodeCompletionTUInfo() override {
2096      return Next.getCodeCompletionTUInfo();
2097    }
2098  };
2099}
2100
2101/// \brief Helper function that computes which global names are hidden by the
2102/// local code-completion results.
2103static void CalculateHiddenNames(const CodeCompletionContext &Context,
2104                                 CodeCompletionResult *Results,
2105                                 unsigned NumResults,
2106                                 ASTContext &Ctx,
2107                          llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
2108  bool OnlyTagNames = false;
2109  switch (Context.getKind()) {
2110  case CodeCompletionContext::CCC_Recovery:
2111  case CodeCompletionContext::CCC_TopLevel:
2112  case CodeCompletionContext::CCC_ObjCInterface:
2113  case CodeCompletionContext::CCC_ObjCImplementation:
2114  case CodeCompletionContext::CCC_ObjCIvarList:
2115  case CodeCompletionContext::CCC_ClassStructUnion:
2116  case CodeCompletionContext::CCC_Statement:
2117  case CodeCompletionContext::CCC_Expression:
2118  case CodeCompletionContext::CCC_ObjCMessageReceiver:
2119  case CodeCompletionContext::CCC_DotMemberAccess:
2120  case CodeCompletionContext::CCC_ArrowMemberAccess:
2121  case CodeCompletionContext::CCC_ObjCPropertyAccess:
2122  case CodeCompletionContext::CCC_Namespace:
2123  case CodeCompletionContext::CCC_Type:
2124  case CodeCompletionContext::CCC_Name:
2125  case CodeCompletionContext::CCC_PotentiallyQualifiedName:
2126  case CodeCompletionContext::CCC_ParenthesizedExpression:
2127  case CodeCompletionContext::CCC_ObjCInterfaceName:
2128    break;
2129
2130  case CodeCompletionContext::CCC_EnumTag:
2131  case CodeCompletionContext::CCC_UnionTag:
2132  case CodeCompletionContext::CCC_ClassOrStructTag:
2133    OnlyTagNames = true;
2134    break;
2135
2136  case CodeCompletionContext::CCC_ObjCProtocolName:
2137  case CodeCompletionContext::CCC_MacroName:
2138  case CodeCompletionContext::CCC_MacroNameUse:
2139  case CodeCompletionContext::CCC_PreprocessorExpression:
2140  case CodeCompletionContext::CCC_PreprocessorDirective:
2141  case CodeCompletionContext::CCC_NaturalLanguage:
2142  case CodeCompletionContext::CCC_SelectorName:
2143  case CodeCompletionContext::CCC_TypeQualifiers:
2144  case CodeCompletionContext::CCC_Other:
2145  case CodeCompletionContext::CCC_OtherWithMacros:
2146  case CodeCompletionContext::CCC_ObjCInstanceMessage:
2147  case CodeCompletionContext::CCC_ObjCClassMessage:
2148  case CodeCompletionContext::CCC_ObjCCategoryName:
2149    // We're looking for nothing, or we're looking for names that cannot
2150    // be hidden.
2151    return;
2152  }
2153
2154  typedef CodeCompletionResult Result;
2155  for (unsigned I = 0; I != NumResults; ++I) {
2156    if (Results[I].Kind != Result::RK_Declaration)
2157      continue;
2158
2159    unsigned IDNS
2160      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
2161
2162    bool Hiding = false;
2163    if (OnlyTagNames)
2164      Hiding = (IDNS & Decl::IDNS_Tag);
2165    else {
2166      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
2167                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
2168                             Decl::IDNS_NonMemberOperator);
2169      if (Ctx.getLangOpts().CPlusPlus)
2170        HiddenIDNS |= Decl::IDNS_Tag;
2171      Hiding = (IDNS & HiddenIDNS);
2172    }
2173
2174    if (!Hiding)
2175      continue;
2176
2177    DeclarationName Name = Results[I].Declaration->getDeclName();
2178    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
2179      HiddenNames.insert(Identifier->getName());
2180    else
2181      HiddenNames.insert(Name.getAsString());
2182  }
2183}
2184
2185
2186void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
2187                                            CodeCompletionContext Context,
2188                                            CodeCompletionResult *Results,
2189                                            unsigned NumResults) {
2190  // Merge the results we were given with the results we cached.
2191  bool AddedResult = false;
2192  uint64_t InContexts =
2193      Context.getKind() == CodeCompletionContext::CCC_Recovery
2194        ? NormalContexts : (1LL << Context.getKind());
2195  // Contains the set of names that are hidden by "local" completion results.
2196  llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
2197  typedef CodeCompletionResult Result;
2198  SmallVector<Result, 8> AllResults;
2199  for (ASTUnit::cached_completion_iterator
2200            C = AST.cached_completion_begin(),
2201         CEnd = AST.cached_completion_end();
2202       C != CEnd; ++C) {
2203    // If the context we are in matches any of the contexts we are
2204    // interested in, we'll add this result.
2205    if ((C->ShowInContexts & InContexts) == 0)
2206      continue;
2207
2208    // If we haven't added any results previously, do so now.
2209    if (!AddedResult) {
2210      CalculateHiddenNames(Context, Results, NumResults, S.Context,
2211                           HiddenNames);
2212      AllResults.insert(AllResults.end(), Results, Results + NumResults);
2213      AddedResult = true;
2214    }
2215
2216    // Determine whether this global completion result is hidden by a local
2217    // completion result. If so, skip it.
2218    if (C->Kind != CXCursor_MacroDefinition &&
2219        HiddenNames.count(C->Completion->getTypedText()))
2220      continue;
2221
2222    // Adjust priority based on similar type classes.
2223    unsigned Priority = C->Priority;
2224    CodeCompletionString *Completion = C->Completion;
2225    if (!Context.getPreferredType().isNull()) {
2226      if (C->Kind == CXCursor_MacroDefinition) {
2227        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
2228                                         S.getLangOpts(),
2229                               Context.getPreferredType()->isAnyPointerType());
2230      } else if (C->Type) {
2231        CanQualType Expected
2232          = S.Context.getCanonicalType(
2233                               Context.getPreferredType().getUnqualifiedType());
2234        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
2235        if (ExpectedSTC == C->TypeClass) {
2236          // We know this type is similar; check for an exact match.
2237          llvm::StringMap<unsigned> &CachedCompletionTypes
2238            = AST.getCachedCompletionTypes();
2239          llvm::StringMap<unsigned>::iterator Pos
2240            = CachedCompletionTypes.find(QualType(Expected).getAsString());
2241          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
2242            Priority /= CCF_ExactTypeMatch;
2243          else
2244            Priority /= CCF_SimilarTypeMatch;
2245        }
2246      }
2247    }
2248
2249    // Adjust the completion string, if required.
2250    if (C->Kind == CXCursor_MacroDefinition &&
2251        Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
2252      // Create a new code-completion string that just contains the
2253      // macro name, without its arguments.
2254      CodeCompletionBuilder Builder(getAllocator(), getCodeCompletionTUInfo(),
2255                                    CCP_CodePattern, C->Availability);
2256      Builder.AddTypedTextChunk(C->Completion->getTypedText());
2257      Priority = CCP_CodePattern;
2258      Completion = Builder.TakeString();
2259    }
2260
2261    AllResults.push_back(Result(Completion, Priority, C->Kind,
2262                                C->Availability));
2263  }
2264
2265  // If we did not add any cached completion results, just forward the
2266  // results we were given to the next consumer.
2267  if (!AddedResult) {
2268    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
2269    return;
2270  }
2271
2272  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
2273                                  AllResults.size());
2274}
2275
2276
2277
2278void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
2279                           ArrayRef<RemappedFile> RemappedFiles,
2280                           bool IncludeMacros,
2281                           bool IncludeCodePatterns,
2282                           bool IncludeBriefComments,
2283                           CodeCompleteConsumer &Consumer,
2284                           DiagnosticsEngine &Diag, LangOptions &LangOpts,
2285                           SourceManager &SourceMgr, FileManager &FileMgr,
2286                   SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
2287             SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
2288  if (!Invocation)
2289    return;
2290
2291  SimpleTimer CompletionTimer(WantTiming);
2292  CompletionTimer.setOutput("Code completion @ " + File + ":" +
2293                            Twine(Line) + ":" + Twine(Column));
2294
2295  IntrusiveRefCntPtr<CompilerInvocation>
2296    CCInvocation(new CompilerInvocation(*Invocation));
2297
2298  FrontendOptions &FrontendOpts = CCInvocation->getFrontendOpts();
2299  CodeCompleteOptions &CodeCompleteOpts = FrontendOpts.CodeCompleteOpts;
2300  PreprocessorOptions &PreprocessorOpts = CCInvocation->getPreprocessorOpts();
2301
2302  CodeCompleteOpts.IncludeMacros = IncludeMacros &&
2303                                   CachedCompletionResults.empty();
2304  CodeCompleteOpts.IncludeCodePatterns = IncludeCodePatterns;
2305  CodeCompleteOpts.IncludeGlobals = CachedCompletionResults.empty();
2306  CodeCompleteOpts.IncludeBriefComments = IncludeBriefComments;
2307
2308  assert(IncludeBriefComments == this->IncludeBriefCommentsInCodeCompletion);
2309
2310  FrontendOpts.CodeCompletionAt.FileName = File;
2311  FrontendOpts.CodeCompletionAt.Line = Line;
2312  FrontendOpts.CodeCompletionAt.Column = Column;
2313
2314  // Set the language options appropriately.
2315  LangOpts = *CCInvocation->getLangOpts();
2316
2317  // Spell-checking and warnings are wasteful during code-completion.
2318  LangOpts.SpellChecking = false;
2319  CCInvocation->getDiagnosticOpts().IgnoreWarnings = true;
2320
2321  std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
2322
2323  // Recover resources if we crash before exiting this method.
2324  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
2325    CICleanup(Clang.get());
2326
2327  Clang->setInvocation(&*CCInvocation);
2328  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].getFile();
2329
2330  // Set up diagnostics, capturing any diagnostics produced.
2331  Clang->setDiagnostics(&Diag);
2332  CaptureDroppedDiagnostics Capture(true,
2333                                    Clang->getDiagnostics(),
2334                                    StoredDiagnostics);
2335  ProcessWarningOptions(Diag, CCInvocation->getDiagnosticOpts());
2336
2337  // Create the target instance.
2338  Clang->setTarget(TargetInfo::CreateTargetInfo(
2339      Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
2340  if (!Clang->hasTarget()) {
2341    Clang->setInvocation(nullptr);
2342    return;
2343  }
2344
2345  // Inform the target of the language options.
2346  //
2347  // FIXME: We shouldn't need to do this, the target should be immutable once
2348  // created. This complexity should be lifted elsewhere.
2349  Clang->getTarget().adjust(Clang->getLangOpts());
2350
2351  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
2352         "Invocation must have exactly one source file!");
2353  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
2354         "FIXME: AST inputs not yet supported here!");
2355  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
2356         "IR inputs not support here!");
2357
2358
2359  // Use the source and file managers that we were given.
2360  Clang->setFileManager(&FileMgr);
2361  Clang->setSourceManager(&SourceMgr);
2362
2363  // Remap files.
2364  PreprocessorOpts.clearRemappedFiles();
2365  PreprocessorOpts.RetainRemappedFileBuffers = true;
2366  for (const auto &RemappedFile : RemappedFiles) {
2367    PreprocessorOpts.addRemappedFile(RemappedFile.first, RemappedFile.second);
2368    OwnedBuffers.push_back(RemappedFile.second);
2369  }
2370
2371  // Use the code completion consumer we were given, but adding any cached
2372  // code-completion results.
2373  AugmentedCodeCompleteConsumer *AugmentedConsumer
2374    = new AugmentedCodeCompleteConsumer(*this, Consumer, CodeCompleteOpts);
2375  Clang->setCodeCompletionConsumer(AugmentedConsumer);
2376
2377  // If we have a precompiled preamble, try to use it. We only allow
2378  // the use of the precompiled preamble if we're if the completion
2379  // point is within the main file, after the end of the precompiled
2380  // preamble.
2381  std::unique_ptr<llvm::MemoryBuffer> OverrideMainBuffer;
2382  if (!getPreambleFile(this).empty()) {
2383    std::string CompleteFilePath(File);
2384    llvm::sys::fs::UniqueID CompleteFileID;
2385
2386    if (!llvm::sys::fs::getUniqueID(CompleteFilePath, CompleteFileID)) {
2387      std::string MainPath(OriginalSourceFile);
2388      llvm::sys::fs::UniqueID MainID;
2389      if (!llvm::sys::fs::getUniqueID(MainPath, MainID)) {
2390        if (CompleteFileID == MainID && Line > 1)
2391          OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(
2392              *CCInvocation, false, Line - 1);
2393      }
2394    }
2395  }
2396
2397  // If the main file has been overridden due to the use of a preamble,
2398  // make that override happen and introduce the preamble.
2399  if (OverrideMainBuffer) {
2400    PreprocessorOpts.addRemappedFile(OriginalSourceFile,
2401                                     OverrideMainBuffer.get());
2402    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
2403    PreprocessorOpts.PrecompiledPreambleBytes.second
2404                                                    = PreambleEndsAtStartOfLine;
2405    PreprocessorOpts.ImplicitPCHInclude = getPreambleFile(this);
2406    PreprocessorOpts.DisablePCHValidation = true;
2407
2408    OwnedBuffers.push_back(OverrideMainBuffer.release());
2409  } else {
2410    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
2411    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
2412  }
2413
2414  // Disable the preprocessing record if modules are not enabled.
2415  if (!Clang->getLangOpts().Modules)
2416    PreprocessorOpts.DetailedRecord = false;
2417
2418  std::unique_ptr<SyntaxOnlyAction> Act;
2419  Act.reset(new SyntaxOnlyAction);
2420  if (Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0])) {
2421    Act->Execute();
2422    Act->EndSourceFile();
2423  }
2424}
2425
2426bool ASTUnit::Save(StringRef File) {
2427  if (HadModuleLoaderFatalFailure)
2428    return true;
2429
2430  // Write to a temporary file and later rename it to the actual file, to avoid
2431  // possible race conditions.
2432  SmallString<128> TempPath;
2433  TempPath = File;
2434  TempPath += "-%%%%%%%%";
2435  int fd;
2436  if (llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath))
2437    return true;
2438
2439  // FIXME: Can we somehow regenerate the stat cache here, or do we need to
2440  // unconditionally create a stat cache when we parse the file?
2441  llvm::raw_fd_ostream Out(fd, /*shouldClose=*/true);
2442
2443  serialize(Out);
2444  Out.close();
2445  if (Out.has_error()) {
2446    Out.clear_error();
2447    return true;
2448  }
2449
2450  if (llvm::sys::fs::rename(TempPath, File)) {
2451    llvm::sys::fs::remove(TempPath);
2452    return true;
2453  }
2454
2455  return false;
2456}
2457
2458static bool serializeUnit(ASTWriter &Writer,
2459                          SmallVectorImpl<char> &Buffer,
2460                          Sema &S,
2461                          bool hasErrors,
2462                          raw_ostream &OS) {
2463  Writer.WriteAST(S, std::string(), nullptr, "", hasErrors);
2464
2465  // Write the generated bitstream to "Out".
2466  if (!Buffer.empty())
2467    OS.write(Buffer.data(), Buffer.size());
2468
2469  return false;
2470}
2471
2472bool ASTUnit::serialize(raw_ostream &OS) {
2473  bool hasErrors = getDiagnostics().hasErrorOccurred();
2474
2475  if (WriterData)
2476    return serializeUnit(WriterData->Writer, WriterData->Buffer,
2477                         getSema(), hasErrors, OS);
2478
2479  SmallString<128> Buffer;
2480  llvm::BitstreamWriter Stream(Buffer);
2481  ASTWriter Writer(Stream);
2482  return serializeUnit(Writer, Buffer, getSema(), hasErrors, OS);
2483}
2484
2485typedef ContinuousRangeMap<unsigned, int, 2> SLocRemap;
2486
2487void ASTUnit::TranslateStoredDiagnostics(
2488                          FileManager &FileMgr,
2489                          SourceManager &SrcMgr,
2490                          const SmallVectorImpl<StandaloneDiagnostic> &Diags,
2491                          SmallVectorImpl<StoredDiagnostic> &Out) {
2492  // Map the standalone diagnostic into the new source manager. We also need to
2493  // remap all the locations to the new view. This includes the diag location,
2494  // any associated source ranges, and the source ranges of associated fix-its.
2495  // FIXME: There should be a cleaner way to do this.
2496
2497  SmallVector<StoredDiagnostic, 4> Result;
2498  Result.reserve(Diags.size());
2499  for (const StandaloneDiagnostic &SD : Diags) {
2500    // Rebuild the StoredDiagnostic.
2501    if (SD.Filename.empty())
2502      continue;
2503    const FileEntry *FE = FileMgr.getFile(SD.Filename);
2504    if (!FE)
2505      continue;
2506    FileID FID = SrcMgr.translateFile(FE);
2507    SourceLocation FileLoc = SrcMgr.getLocForStartOfFile(FID);
2508    if (FileLoc.isInvalid())
2509      continue;
2510    SourceLocation L = FileLoc.getLocWithOffset(SD.LocOffset);
2511    FullSourceLoc Loc(L, SrcMgr);
2512
2513    SmallVector<CharSourceRange, 4> Ranges;
2514    Ranges.reserve(SD.Ranges.size());
2515    for (const auto &Range : SD.Ranges) {
2516      SourceLocation BL = FileLoc.getLocWithOffset(Range.first);
2517      SourceLocation EL = FileLoc.getLocWithOffset(Range.second);
2518      Ranges.push_back(CharSourceRange::getCharRange(BL, EL));
2519    }
2520
2521    SmallVector<FixItHint, 2> FixIts;
2522    FixIts.reserve(SD.FixIts.size());
2523    for (const StandaloneFixIt &FixIt : SD.FixIts) {
2524      FixIts.push_back(FixItHint());
2525      FixItHint &FH = FixIts.back();
2526      FH.CodeToInsert = FixIt.CodeToInsert;
2527      SourceLocation BL = FileLoc.getLocWithOffset(FixIt.RemoveRange.first);
2528      SourceLocation EL = FileLoc.getLocWithOffset(FixIt.RemoveRange.second);
2529      FH.RemoveRange = CharSourceRange::getCharRange(BL, EL);
2530    }
2531
2532    Result.push_back(StoredDiagnostic(SD.Level, SD.ID,
2533                                      SD.Message, Loc, Ranges, FixIts));
2534  }
2535  Result.swap(Out);
2536}
2537
2538void ASTUnit::addFileLevelDecl(Decl *D) {
2539  assert(D);
2540
2541  // We only care about local declarations.
2542  if (D->isFromASTFile())
2543    return;
2544
2545  SourceManager &SM = *SourceMgr;
2546  SourceLocation Loc = D->getLocation();
2547  if (Loc.isInvalid() || !SM.isLocalSourceLocation(Loc))
2548    return;
2549
2550  // We only keep track of the file-level declarations of each file.
2551  if (!D->getLexicalDeclContext()->isFileContext())
2552    return;
2553
2554  SourceLocation FileLoc = SM.getFileLoc(Loc);
2555  assert(SM.isLocalSourceLocation(FileLoc));
2556  FileID FID;
2557  unsigned Offset;
2558  std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
2559  if (FID.isInvalid())
2560    return;
2561
2562  LocDeclsTy *&Decls = FileDecls[FID];
2563  if (!Decls)
2564    Decls = new LocDeclsTy();
2565
2566  std::pair<unsigned, Decl *> LocDecl(Offset, D);
2567
2568  if (Decls->empty() || Decls->back().first <= Offset) {
2569    Decls->push_back(LocDecl);
2570    return;
2571  }
2572
2573  LocDeclsTy::iterator I = std::upper_bound(Decls->begin(), Decls->end(),
2574                                            LocDecl, llvm::less_first());
2575
2576  Decls->insert(I, LocDecl);
2577}
2578
2579void ASTUnit::findFileRegionDecls(FileID File, unsigned Offset, unsigned Length,
2580                                  SmallVectorImpl<Decl *> &Decls) {
2581  if (File.isInvalid())
2582    return;
2583
2584  if (SourceMgr->isLoadedFileID(File)) {
2585    assert(Ctx->getExternalSource() && "No external source!");
2586    return Ctx->getExternalSource()->FindFileRegionDecls(File, Offset, Length,
2587                                                         Decls);
2588  }
2589
2590  FileDeclsTy::iterator I = FileDecls.find(File);
2591  if (I == FileDecls.end())
2592    return;
2593
2594  LocDeclsTy &LocDecls = *I->second;
2595  if (LocDecls.empty())
2596    return;
2597
2598  LocDeclsTy::iterator BeginIt =
2599      std::lower_bound(LocDecls.begin(), LocDecls.end(),
2600                       std::make_pair(Offset, (Decl *)nullptr),
2601                       llvm::less_first());
2602  if (BeginIt != LocDecls.begin())
2603    --BeginIt;
2604
2605  // If we are pointing at a top-level decl inside an objc container, we need
2606  // to backtrack until we find it otherwise we will fail to report that the
2607  // region overlaps with an objc container.
2608  while (BeginIt != LocDecls.begin() &&
2609         BeginIt->second->isTopLevelDeclInObjCContainer())
2610    --BeginIt;
2611
2612  LocDeclsTy::iterator EndIt = std::upper_bound(
2613      LocDecls.begin(), LocDecls.end(),
2614      std::make_pair(Offset + Length, (Decl *)nullptr), llvm::less_first());
2615  if (EndIt != LocDecls.end())
2616    ++EndIt;
2617
2618  for (LocDeclsTy::iterator DIt = BeginIt; DIt != EndIt; ++DIt)
2619    Decls.push_back(DIt->second);
2620}
2621
2622SourceLocation ASTUnit::getLocation(const FileEntry *File,
2623                                    unsigned Line, unsigned Col) const {
2624  const SourceManager &SM = getSourceManager();
2625  SourceLocation Loc = SM.translateFileLineCol(File, Line, Col);
2626  return SM.getMacroArgExpandedLocation(Loc);
2627}
2628
2629SourceLocation ASTUnit::getLocation(const FileEntry *File,
2630                                    unsigned Offset) const {
2631  const SourceManager &SM = getSourceManager();
2632  SourceLocation FileLoc = SM.translateFileLineCol(File, 1, 1);
2633  return SM.getMacroArgExpandedLocation(FileLoc.getLocWithOffset(Offset));
2634}
2635
2636/// \brief If \arg Loc is a loaded location from the preamble, returns
2637/// the corresponding local location of the main file, otherwise it returns
2638/// \arg Loc.
2639SourceLocation ASTUnit::mapLocationFromPreamble(SourceLocation Loc) {
2640  FileID PreambleID;
2641  if (SourceMgr)
2642    PreambleID = SourceMgr->getPreambleFileID();
2643
2644  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2645    return Loc;
2646
2647  unsigned Offs;
2648  if (SourceMgr->isInFileID(Loc, PreambleID, &Offs) && Offs < Preamble.size()) {
2649    SourceLocation FileLoc
2650        = SourceMgr->getLocForStartOfFile(SourceMgr->getMainFileID());
2651    return FileLoc.getLocWithOffset(Offs);
2652  }
2653
2654  return Loc;
2655}
2656
2657/// \brief If \arg Loc is a local location of the main file but inside the
2658/// preamble chunk, returns the corresponding loaded location from the
2659/// preamble, otherwise it returns \arg Loc.
2660SourceLocation ASTUnit::mapLocationToPreamble(SourceLocation Loc) {
2661  FileID PreambleID;
2662  if (SourceMgr)
2663    PreambleID = SourceMgr->getPreambleFileID();
2664
2665  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2666    return Loc;
2667
2668  unsigned Offs;
2669  if (SourceMgr->isInFileID(Loc, SourceMgr->getMainFileID(), &Offs) &&
2670      Offs < Preamble.size()) {
2671    SourceLocation FileLoc = SourceMgr->getLocForStartOfFile(PreambleID);
2672    return FileLoc.getLocWithOffset(Offs);
2673  }
2674
2675  return Loc;
2676}
2677
2678bool ASTUnit::isInPreambleFileID(SourceLocation Loc) {
2679  FileID FID;
2680  if (SourceMgr)
2681    FID = SourceMgr->getPreambleFileID();
2682
2683  if (Loc.isInvalid() || FID.isInvalid())
2684    return false;
2685
2686  return SourceMgr->isInFileID(Loc, FID);
2687}
2688
2689bool ASTUnit::isInMainFileID(SourceLocation Loc) {
2690  FileID FID;
2691  if (SourceMgr)
2692    FID = SourceMgr->getMainFileID();
2693
2694  if (Loc.isInvalid() || FID.isInvalid())
2695    return false;
2696
2697  return SourceMgr->isInFileID(Loc, FID);
2698}
2699
2700SourceLocation ASTUnit::getEndOfPreambleFileID() {
2701  FileID FID;
2702  if (SourceMgr)
2703    FID = SourceMgr->getPreambleFileID();
2704
2705  if (FID.isInvalid())
2706    return SourceLocation();
2707
2708  return SourceMgr->getLocForEndOfFile(FID);
2709}
2710
2711SourceLocation ASTUnit::getStartOfMainFileID() {
2712  FileID FID;
2713  if (SourceMgr)
2714    FID = SourceMgr->getMainFileID();
2715
2716  if (FID.isInvalid())
2717    return SourceLocation();
2718
2719  return SourceMgr->getLocForStartOfFile(FID);
2720}
2721
2722llvm::iterator_range<PreprocessingRecord::iterator>
2723ASTUnit::getLocalPreprocessingEntities() const {
2724  if (isMainFileAST()) {
2725    serialization::ModuleFile &
2726      Mod = Reader->getModuleManager().getPrimaryModule();
2727    return Reader->getModulePreprocessedEntities(Mod);
2728  }
2729
2730  if (PreprocessingRecord *PPRec = PP->getPreprocessingRecord())
2731    return llvm::make_range(PPRec->local_begin(), PPRec->local_end());
2732
2733  return llvm::make_range(PreprocessingRecord::iterator(),
2734                          PreprocessingRecord::iterator());
2735}
2736
2737bool ASTUnit::visitLocalTopLevelDecls(void *context, DeclVisitorFn Fn) {
2738  if (isMainFileAST()) {
2739    serialization::ModuleFile &
2740      Mod = Reader->getModuleManager().getPrimaryModule();
2741    for (const Decl *D : Reader->getModuleFileLevelDecls(Mod)) {
2742      if (!Fn(context, D))
2743        return false;
2744    }
2745
2746    return true;
2747  }
2748
2749  for (ASTUnit::top_level_iterator TL = top_level_begin(),
2750                                TLEnd = top_level_end();
2751         TL != TLEnd; ++TL) {
2752    if (!Fn(context, *TL))
2753      return false;
2754  }
2755
2756  return true;
2757}
2758
2759namespace {
2760struct PCHLocatorInfo {
2761  serialization::ModuleFile *Mod;
2762  PCHLocatorInfo() : Mod(nullptr) {}
2763};
2764}
2765
2766static bool PCHLocator(serialization::ModuleFile &M, void *UserData) {
2767  PCHLocatorInfo &Info = *static_cast<PCHLocatorInfo*>(UserData);
2768  switch (M.Kind) {
2769  case serialization::MK_ImplicitModule:
2770  case serialization::MK_ExplicitModule:
2771    return true; // skip dependencies.
2772  case serialization::MK_PCH:
2773    Info.Mod = &M;
2774    return true; // found it.
2775  case serialization::MK_Preamble:
2776    return false; // look in dependencies.
2777  case serialization::MK_MainFile:
2778    return false; // look in dependencies.
2779  }
2780
2781  return true;
2782}
2783
2784const FileEntry *ASTUnit::getPCHFile() {
2785  if (!Reader)
2786    return nullptr;
2787
2788  PCHLocatorInfo Info;
2789  Reader->getModuleManager().visit(PCHLocator, &Info);
2790  if (Info.Mod)
2791    return Info.Mod->File;
2792
2793  return nullptr;
2794}
2795
2796bool ASTUnit::isModuleFile() {
2797  return isMainFileAST() && !ASTFileLangOpts.CurrentModule.empty();
2798}
2799
2800void ASTUnit::PreambleData::countLines() const {
2801  NumLines = 0;
2802  if (empty())
2803    return;
2804
2805  NumLines = std::count(Buffer.begin(), Buffer.end(), '\n');
2806
2807  if (Buffer.back() != '\n')
2808    ++NumLines;
2809}
2810
2811#ifndef NDEBUG
2812ASTUnit::ConcurrencyState::ConcurrencyState() {
2813  Mutex = new llvm::sys::MutexImpl(/*recursive=*/true);
2814}
2815
2816ASTUnit::ConcurrencyState::~ConcurrencyState() {
2817  delete static_cast<llvm::sys::MutexImpl *>(Mutex);
2818}
2819
2820void ASTUnit::ConcurrencyState::start() {
2821  bool acquired = static_cast<llvm::sys::MutexImpl *>(Mutex)->tryacquire();
2822  assert(acquired && "Concurrent access to ASTUnit!");
2823}
2824
2825void ASTUnit::ConcurrencyState::finish() {
2826  static_cast<llvm::sys::MutexImpl *>(Mutex)->release();
2827}
2828
2829#else // NDEBUG
2830
2831ASTUnit::ConcurrencyState::ConcurrencyState() { Mutex = 0; }
2832ASTUnit::ConcurrencyState::~ConcurrencyState() {}
2833void ASTUnit::ConcurrencyState::start() {}
2834void ASTUnit::ConcurrencyState::finish() {}
2835
2836#endif
2837