contrib/llvm/tools/clang/lib/Frontend/ASTUnit.cpp

   1 //===--- ASTUnit.cpp - ASTUnit utility ------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // ASTUnit Implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Frontend/ASTUnit.h"
  15 #include "clang/AST/ASTContext.h"
  16 #include "clang/AST/ASTConsumer.h"
  17 #include "clang/AST/DeclVisitor.h"
  18 #include "clang/AST/TypeOrdering.h"
  19 #include "clang/AST/StmtVisitor.h"
  20 #include "clang/Driver/Compilation.h"
  21 #include "clang/Driver/Driver.h"
  22 #include "clang/Driver/Job.h"
  23 #include "clang/Driver/ArgList.h"
  24 #include "clang/Driver/Options.h"
  25 #include "clang/Driver/Tool.h"
  26 #include "clang/Frontend/CompilerInstance.h"
  27 #include "clang/Frontend/FrontendActions.h"
  28 #include "clang/Frontend/FrontendDiagnostic.h"
  29 #include "clang/Frontend/FrontendOptions.h"
  30 #include "clang/Frontend/Utils.h"
  31 #include "clang/Serialization/ASTReader.h"
  32 #include "clang/Serialization/ASTSerializationListener.h"
  33 #include "clang/Serialization/ASTWriter.h"
  34 #include "clang/Lex/HeaderSearch.h"
  35 #include "clang/Lex/Preprocessor.h"
  36 #include "clang/Basic/TargetOptions.h"
  37 #include "clang/Basic/TargetInfo.h"
  38 #include "clang/Basic/Diagnostic.h"
  39 #include "llvm/ADT/ArrayRef.h"
  40 #include "llvm/ADT/StringExtras.h"
  41 #include "llvm/ADT/StringSet.h"
  42 #include "llvm/Support/Atomic.h"
  43 #include "llvm/Support/MemoryBuffer.h"
  44 #include "llvm/Support/Host.h"
  45 #include "llvm/Support/Path.h"
  46 #include "llvm/Support/raw_ostream.h"
  47 #include "llvm/Support/Timer.h"
  48 #include "llvm/Support/CrashRecoveryContext.h"
  49 #include <cstdlib>
  50 #include <cstdio>
  51 #include <sys/stat.h>
  52 using namespace clang;
  53
  54 using llvm::TimeRecord;
  55
  56 namespace {
  57   class SimpleTimer {
  58     bool WantTiming;
  59     TimeRecord Start;
  60     std::string Output;
  61
  62   public:
  63     explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
  64       if (WantTiming)
  65         Start = TimeRecord::getCurrentTime();
  66     }
  67
  68     void setOutput(const llvm::Twine &Output) {
  69       if (WantTiming)
  70         this->Output = Output.str();
  71     }
  72
  73     ~SimpleTimer() {
  74       if (WantTiming) {
  75         TimeRecord Elapsed = TimeRecord::getCurrentTime();
  76         Elapsed -= Start;
  77         llvm::errs() << Output << ':';
  78         Elapsed.print(Elapsed, llvm::errs());
  79         llvm::errs() << '\n';
  80       }
  81     }
  82   };
  83 }
  84
  85 /// \brief After failing to build a precompiled preamble (due to
  86 /// errors in the source that occurs in the preamble), the number of
  87 /// reparses during which we'll skip even trying to precompile the
  88 /// preamble.
  89 const unsigned DefaultPreambleRebuildInterval = 5;
  90
  91 /// \brief Tracks the number of ASTUnit objects that are currently active.
  92 ///
  93 /// Used for debugging purposes only.
  94 static llvm::sys::cas_flag ActiveASTUnitObjects;
  95
  96 ASTUnit::ASTUnit(bool _MainFileIsAST)
  97   : OnlyLocalDecls(false), CaptureDiagnostics(false),
  98     MainFileIsAST(_MainFileIsAST),
  99     CompleteTranslationUnit(true), WantTiming(getenv("LIBCLANG_TIMING")),
 100     OwnsRemappedFileBuffers(true),
 101     NumStoredDiagnosticsFromDriver(0),
 102     ConcurrencyCheckValue(CheckUnlocked),
 103     PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
 104     ShouldCacheCodeCompletionResults(false),
 105     NestedMacroExpansions(true),
 106     CompletionCacheTopLevelHashValue(0),
 107     PreambleTopLevelHashValue(0),
 108     CurrentTopLevelHashValue(0),
 109     UnsafeToFree(false) {
 110   if (getenv("LIBCLANG_OBJTRACKING")) {
 111     llvm::sys::AtomicIncrement(&ActiveASTUnitObjects);
 112     fprintf(stderr, "+++ %d translation units\n", ActiveASTUnitObjects);
 113   }
 114 }
 115
 116 ASTUnit::~ASTUnit() {
 117   ConcurrencyCheckValue = CheckLocked;
 118   CleanTemporaryFiles();
 119   if (!PreambleFile.empty())
 120     llvm::sys::Path(PreambleFile).eraseFromDisk();
 121
 122   // Free the buffers associated with remapped files. We are required to
 123   // perform this operation here because we explicitly request that the
 124   // compiler instance *not* free these buffers for each invocation of the
 125   // parser.
 126   if (Invocation.getPtr() && OwnsRemappedFileBuffers) {
 127     PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
 128     for (PreprocessorOptions::remapped_file_buffer_iterator
 129            FB = PPOpts.remapped_file_buffer_begin(),
 130            FBEnd = PPOpts.remapped_file_buffer_end();
 131          FB != FBEnd;
 132          ++FB)
 133       delete FB->second;
 134   }
 135
 136   delete SavedMainFileBuffer;
 137   delete PreambleBuffer;
 138
 139   ClearCachedCompletionResults();
 140
 141   if (getenv("LIBCLANG_OBJTRACKING")) {
 142     llvm::sys::AtomicDecrement(&ActiveASTUnitObjects);
 143     fprintf(stderr, "--- %d translation units\n", ActiveASTUnitObjects);
 144   }
 145 }
 146
 147 void ASTUnit::CleanTemporaryFiles() {
 148   for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
 149     TemporaryFiles[I].eraseFromDisk();
 150   TemporaryFiles.clear();
 151 }
 152
 153 /// \brief Determine the set of code-completion contexts in which this
 154 /// declaration should be shown.
 155 static unsigned getDeclShowContexts(NamedDecl *ND,
 156                                     const LangOptions &LangOpts,
 157                                     bool &IsNestedNameSpecifier) {
 158   IsNestedNameSpecifier = false;
 159
 160   if (isa<UsingShadowDecl>(ND))
 161     ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
 162   if (!ND)
 163     return 0;
 164
 165   unsigned Contexts = 0;
 166   if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
 167       isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
 168     // Types can appear in these contexts.
 169     if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
 170       Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 171                 | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 172                 | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 173                 | (1 << (CodeCompletionContext::CCC_Statement - 1))
 174                 | (1 << (CodeCompletionContext::CCC_Type - 1))
 175               | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
 176
 177     // In C++, types can appear in expressions contexts (for functional casts).
 178     if (LangOpts.CPlusPlus)
 179       Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
 180
 181     // In Objective-C, message sends can send interfaces. In Objective-C++,
 182     // all types are available due to functional casts.
 183     if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
 184       Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
 185
 186     // In Objective-C, you can only be a subclass of another Objective-C class
 187     if (isa<ObjCInterfaceDecl>(ND))
 188       Contexts |= (1 << (CodeCompletionContext::CCC_ObjCSuperclass - 1));
 189
 190     // Deal with tag names.
 191     if (isa<EnumDecl>(ND)) {
 192       Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
 193
 194       // Part of the nested-name-specifier in C++0x.
 195       if (LangOpts.CPlusPlus0x)
 196         IsNestedNameSpecifier = true;
 197     } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
 198       if (Record->isUnion())
 199         Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
 200       else
 201         Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
 202
 203       if (LangOpts.CPlusPlus)
 204         IsNestedNameSpecifier = true;
 205     } else if (isa<ClassTemplateDecl>(ND))
 206       IsNestedNameSpecifier = true;
 207   } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
 208     // Values can appear in these contexts.
 209     Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
 210              | (1 << (CodeCompletionContext::CCC_Expression - 1))
 211              | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
 212              | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
 213   } else if (isa<ObjCProtocolDecl>(ND)) {
 214     Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
 215   } else if (isa<ObjCCategoryDecl>(ND)) {
 216     Contexts = (1 << (CodeCompletionContext::CCC_ObjCCategoryName - 1));
 217   } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
 218     Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
 219
 220     // Part of the nested-name-specifier.
 221     IsNestedNameSpecifier = true;
 222   }
 223
 224   return Contexts;
 225 }
 226
 227 void ASTUnit::CacheCodeCompletionResults() {
 228   if (!TheSema)
 229     return;
 230
 231   SimpleTimer Timer(WantTiming);
 232   Timer.setOutput("Cache global code completions for " + getMainFileName());
 233
 234   // Clear out the previous results.
 235   ClearCachedCompletionResults();
 236
 237   // Gather the set of global code completions.
 238   typedef CodeCompletionResult Result;
 239   llvm::SmallVector<Result, 8> Results;
 240   CachedCompletionAllocator = new GlobalCodeCompletionAllocator;
 241   TheSema->GatherGlobalCodeCompletions(*CachedCompletionAllocator, Results);
 242
 243   // Translate global code completions into cached completions.
 244   llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
 245
 246   for (unsigned I = 0, N = Results.size(); I != N; ++I) {
 247     switch (Results[I].Kind) {
 248     case Result::RK_Declaration: {
 249       bool IsNestedNameSpecifier = false;
 250       CachedCodeCompletionResult CachedResult;
 251       CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema,
 252                                                     *CachedCompletionAllocator);
 253       CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
 254                                                         Ctx->getLangOptions(),
 255                                                         IsNestedNameSpecifier);
 256       CachedResult.Priority = Results[I].Priority;
 257       CachedResult.Kind = Results[I].CursorKind;
 258       CachedResult.Availability = Results[I].Availability;
 259
 260       // Keep track of the type of this completion in an ASTContext-agnostic
 261       // way.
 262       QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
 263       if (UsageType.isNull()) {
 264         CachedResult.TypeClass = STC_Void;
 265         CachedResult.Type = 0;
 266       } else {
 267         CanQualType CanUsageType
 268           = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
 269         CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
 270
 271         // Determine whether we have already seen this type. If so, we save
 272         // ourselves the work of formatting the type string by using the
 273         // temporary, CanQualType-based hash table to find the associated value.
 274         unsigned &TypeValue = CompletionTypes[CanUsageType];
 275         if (TypeValue == 0) {
 276           TypeValue = CompletionTypes.size();
 277           CachedCompletionTypes[QualType(CanUsageType).getAsString()]
 278             = TypeValue;
 279         }
 280
 281         CachedResult.Type = TypeValue;
 282       }
 283
 284       CachedCompletionResults.push_back(CachedResult);
 285
 286       /// Handle nested-name-specifiers in C++.
 287       if (TheSema->Context.getLangOptions().CPlusPlus &&
 288           IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
 289         // The contexts in which a nested-name-specifier can appear in C++.
 290         unsigned NNSContexts
 291           = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 292           | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 293           | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 294           | (1 << (CodeCompletionContext::CCC_Statement - 1))
 295           | (1 << (CodeCompletionContext::CCC_Expression - 1))
 296           | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
 297           | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
 298           | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
 299           | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
 300           | (1 << (CodeCompletionContext::CCC_Type - 1))
 301           | (1 << (CodeCompletionContext::CCC_PotentiallyQualifiedName - 1))
 302           | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
 303
 304         if (isa<NamespaceDecl>(Results[I].Declaration) ||
 305             isa<NamespaceAliasDecl>(Results[I].Declaration))
 306           NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
 307
 308         if (unsigned RemainingContexts
 309                                 = NNSContexts & ~CachedResult.ShowInContexts) {
 310           // If there any contexts where this completion can be a
 311           // nested-name-specifier but isn't already an option, create a
 312           // nested-name-specifier completion.
 313           Results[I].StartsNestedNameSpecifier = true;
 314           CachedResult.Completion
 315             = Results[I].CreateCodeCompletionString(*TheSema,
 316                                                     *CachedCompletionAllocator);
 317           CachedResult.ShowInContexts = RemainingContexts;
 318           CachedResult.Priority = CCP_NestedNameSpecifier;
 319           CachedResult.TypeClass = STC_Void;
 320           CachedResult.Type = 0;
 321           CachedCompletionResults.push_back(CachedResult);
 322         }
 323       }
 324       break;
 325     }
 326
 327     case Result::RK_Keyword:
 328     case Result::RK_Pattern:
 329       // Ignore keywords and patterns; we don't care, since they are so
 330       // easily regenerated.
 331       break;
 332
 333     case Result::RK_Macro: {
 334       CachedCodeCompletionResult CachedResult;
 335       CachedResult.Completion
 336         = Results[I].CreateCodeCompletionString(*TheSema,
 337                                                 *CachedCompletionAllocator);
 338       CachedResult.ShowInContexts
 339         = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 340         | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
 341         | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
 342         | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 343         | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 344         | (1 << (CodeCompletionContext::CCC_Statement - 1))
 345         | (1 << (CodeCompletionContext::CCC_Expression - 1))
 346         | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
 347         | (1 << (CodeCompletionContext::CCC_MacroNameUse - 1))
 348         | (1 << (CodeCompletionContext::CCC_PreprocessorExpression - 1))
 349         | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
 350         | (1 << (CodeCompletionContext::CCC_OtherWithMacros - 1));
 351
 352       CachedResult.Priority = Results[I].Priority;
 353       CachedResult.Kind = Results[I].CursorKind;
 354       CachedResult.Availability = Results[I].Availability;
 355       CachedResult.TypeClass = STC_Void;
 356       CachedResult.Type = 0;
 357       CachedCompletionResults.push_back(CachedResult);
 358       break;
 359     }
 360     }
 361   }
 362
 363   // Save the current top-level hash value.
 364   CompletionCacheTopLevelHashValue = CurrentTopLevelHashValue;
 365 }
 366
 367 void ASTUnit::ClearCachedCompletionResults() {
 368   CachedCompletionResults.clear();
 369   CachedCompletionTypes.clear();
 370   CachedCompletionAllocator = 0;
 371 }
 372
 373 namespace {
 374
 375 /// \brief Gathers information from ASTReader that will be used to initialize
 376 /// a Preprocessor.
 377 class ASTInfoCollector : public ASTReaderListener {
 378   LangOptions &LangOpt;
 379   HeaderSearch &HSI;
 380   std::string &TargetTriple;
 381   std::string &Predefines;
 382   unsigned &Counter;
 383
 384   unsigned NumHeaderInfos;
 385
 386 public:
 387   ASTInfoCollector(LangOptions &LangOpt, HeaderSearch &HSI,
 388                    std::string &TargetTriple, std::string &Predefines,
 389                    unsigned &Counter)
 390     : LangOpt(LangOpt), HSI(HSI), TargetTriple(TargetTriple),
 391       Predefines(Predefines), Counter(Counter), NumHeaderInfos(0) {}
 392
 393   virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
 394     LangOpt = LangOpts;
 395     return false;
 396   }
 397
 398   virtual bool ReadTargetTriple(llvm::StringRef Triple) {
 399     TargetTriple = Triple;
 400     return false;
 401   }
 402
 403   virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
 404                                     llvm::StringRef OriginalFileName,
 405                                     std::string &SuggestedPredefines,
 406                                     FileManager &FileMgr) {
 407     Predefines = Buffers[0].Data;
 408     for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
 409       Predefines += Buffers[I].Data;
 410     }
 411     return false;
 412   }
 413
 414   virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
 415     HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
 416   }
 417
 418   virtual void ReadCounter(unsigned Value) {
 419     Counter = Value;
 420   }
 421 };
 422
 423 class StoredDiagnosticClient : public DiagnosticClient {
 424   llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags;
 425
 426 public:
 427   explicit StoredDiagnosticClient(
 428                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
 429     : StoredDiags(StoredDiags) { }
 430
 431   virtual void HandleDiagnostic(Diagnostic::Level Level,
 432                                 const DiagnosticInfo &Info);
 433 };
 434
 435 /// \brief RAII object that optionally captures diagnostics, if
 436 /// there is no diagnostic client to capture them already.
 437 class CaptureDroppedDiagnostics {
 438   Diagnostic &Diags;
 439   StoredDiagnosticClient Client;
 440   DiagnosticClient *PreviousClient;
 441
 442 public:
 443   CaptureDroppedDiagnostics(bool RequestCapture, Diagnostic &Diags,
 444                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
 445     : Diags(Diags), Client(StoredDiags), PreviousClient(0)
 446   {
 447     if (RequestCapture || Diags.getClient() == 0) {
 448       PreviousClient = Diags.takeClient();
 449       Diags.setClient(&Client);
 450     }
 451   }
 452
 453   ~CaptureDroppedDiagnostics() {
 454     if (Diags.getClient() == &Client) {
 455       Diags.takeClient();
 456       Diags.setClient(PreviousClient);
 457     }
 458   }
 459 };
 460
 461 } // anonymous namespace
 462
 463 void StoredDiagnosticClient::HandleDiagnostic(Diagnostic::Level Level,
 464                                               const DiagnosticInfo &Info) {
 465   // Default implementation (Warnings/errors count).
 466   DiagnosticClient::HandleDiagnostic(Level, Info);
 467
 468   StoredDiags.push_back(StoredDiagnostic(Level, Info));
 469 }
 470
 471 const std::string &ASTUnit::getOriginalSourceFileName() {
 472   return OriginalSourceFile;
 473 }
 474
 475 const std::string &ASTUnit::getASTFileName() {
 476   assert(isMainFileAST() && "Not an ASTUnit from an AST file!");
 477   return static_cast<ASTReader *>(Ctx->getExternalSource())->getFileName();
 478 }
 479
 480 llvm::MemoryBuffer *ASTUnit::getBufferForFile(llvm::StringRef Filename,
 481                                               std::string *ErrorStr) {
 482   assert(FileMgr);
 483   return FileMgr->getBufferForFile(Filename, ErrorStr);
 484 }
 485
 486 /// \brief Configure the diagnostics object for use with ASTUnit.
 487 void ASTUnit::ConfigureDiags(llvm::IntrusiveRefCntPtr<Diagnostic> &Diags,
 488                              const char **ArgBegin, const char **ArgEnd,
 489                              ASTUnit &AST, bool CaptureDiagnostics) {
 490   if (!Diags.getPtr()) {
 491     // No diagnostics engine was provided, so create our own diagnostics object
 492     // with the default options.
 493     DiagnosticOptions DiagOpts;
 494     DiagnosticClient *Client = 0;
 495     if (CaptureDiagnostics)
 496       Client = new StoredDiagnosticClient(AST.StoredDiagnostics);
 497     Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd- ArgBegin,
 498                                                 ArgBegin, Client);
 499   } else if (CaptureDiagnostics) {
 500     Diags->setClient(new StoredDiagnosticClient(AST.StoredDiagnostics));
 501   }
 502 }
 503
 504 ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
 505                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
 506                                   const FileSystemOptions &FileSystemOpts,
 507                                   bool OnlyLocalDecls,
 508                                   RemappedFile *RemappedFiles,
 509                                   unsigned NumRemappedFiles,
 510                                   bool CaptureDiagnostics) {
 511   llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
 512
 513   // Recover resources if we crash before exiting this method.
 514   llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
 515     ASTUnitCleanup(AST.get());
 516   llvm::CrashRecoveryContextCleanupRegistrar<Diagnostic,
 517     llvm::CrashRecoveryContextReleaseRefCleanup<Diagnostic> >
 518     DiagCleanup(Diags.getPtr());
 519
 520   ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
 521
 522   AST->OnlyLocalDecls = OnlyLocalDecls;
 523   AST->CaptureDiagnostics = CaptureDiagnostics;
 524   AST->Diagnostics = Diags;
 525   AST->FileMgr = new FileManager(FileSystemOpts);
 526   AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
 527                                      AST->getFileManager());
 528   AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
 529
 530   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
 531     FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
 532     if (const llvm::MemoryBuffer *
 533           memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
 534       // Create the file entry for the file that we're mapping from.
 535       const FileEntry *FromFile
 536         = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
 537                                                memBuf->getBufferSize(),
 538                                                0);
 539       if (!FromFile) {
 540         AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
 541           << RemappedFiles[I].first;
 542         delete memBuf;
 543         continue;
 544       }
 545
 546       // Override the contents of the "from" file with the contents of
 547       // the "to" file.
 548       AST->getSourceManager().overrideFileContents(FromFile, memBuf);
 549
 550     } else {
 551       const char *fname = fileOrBuf.get<const char *>();
 552       const FileEntry *ToFile = AST->FileMgr->getFile(fname);
 553       if (!ToFile) {
 554         AST->getDiagnostics().Report(diag::err_fe_remap_missing_to_file)
 555         << RemappedFiles[I].first << fname;
 556         continue;
 557       }
 558
 559       // Create the file entry for the file that we're mapping from.
 560       const FileEntry *FromFile
 561         = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
 562                                                ToFile->getSize(),
 563                                                0);
 564       if (!FromFile) {
 565         AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
 566           << RemappedFiles[I].first;
 567         delete memBuf;
 568         continue;
 569       }
 570
 571       // Override the contents of the "from" file with the contents of
 572       // the "to" file.
 573       AST->getSourceManager().overrideFileContents(FromFile, ToFile);
 574     }
 575   }
 576
 577   // Gather Info for preprocessor construction later on.
 578
 579   LangOptions LangInfo;
 580   HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
 581   std::string TargetTriple;
 582   std::string Predefines;
 583   unsigned Counter;
 584
 585   llvm::OwningPtr<ASTReader> Reader;
 586
 587   Reader.reset(new ASTReader(AST->getSourceManager(), AST->getFileManager(),
 588                              AST->getDiagnostics()));
 589
 590   // Recover resources if we crash before exiting this method.
 591   llvm::CrashRecoveryContextCleanupRegistrar<ASTReader>
 592     ReaderCleanup(Reader.get());
 593
 594   Reader->setListener(new ASTInfoCollector(LangInfo, HeaderInfo, TargetTriple,
 595                                            Predefines, Counter));
 596
 597   switch (Reader->ReadAST(Filename, ASTReader::MainFile)) {
 598   case ASTReader::Success:
 599     break;
 600
 601   case ASTReader::Failure:
 602   case ASTReader::IgnorePCH:
 603     AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
 604     return NULL;
 605   }
 606
 607   AST->OriginalSourceFile = Reader->getOriginalSourceFile();
 608
 609   // AST file loaded successfully. Now create the preprocessor.
 610
 611   // Get information about the target being compiled for.
 612   //
 613   // FIXME: This is broken, we should store the TargetOptions in the AST file.
 614   TargetOptions TargetOpts;
 615   TargetOpts.ABI = "";
 616   TargetOpts.CXXABI = "";
 617   TargetOpts.CPU = "";
 618   TargetOpts.Features.clear();
 619   TargetOpts.Triple = TargetTriple;
 620   AST->Target = TargetInfo::CreateTargetInfo(AST->getDiagnostics(),
 621                                              TargetOpts);
 622   AST->PP = new Preprocessor(AST->getDiagnostics(), LangInfo, *AST->Target,
 623                              AST->getSourceManager(), HeaderInfo);
 624   Preprocessor &PP = *AST->PP;
 625
 626   PP.setPredefines(Reader->getSuggestedPredefines());
 627   PP.setCounterValue(Counter);
 628   Reader->setPreprocessor(PP);
 629
 630   // Create and initialize the ASTContext.
 631
 632   AST->Ctx = new ASTContext(LangInfo,
 633                             AST->getSourceManager(),
 634                             *AST->Target,
 635                             PP.getIdentifierTable(),
 636                             PP.getSelectorTable(),
 637                             PP.getBuiltinInfo(),
 638                             /* size_reserve = */0);
 639   ASTContext &Context = *AST->Ctx;
 640
 641   Reader->InitializeContext(Context);
 642
 643   // Attach the AST reader to the AST context as an external AST
 644   // source, so that declarations will be deserialized from the
 645   // AST file as needed.
 646   ASTReader *ReaderPtr = Reader.get();
 647   llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
 648
 649   // Unregister the cleanup for ASTReader.  It will get cleaned up
 650   // by the ASTUnit cleanup.
 651   ReaderCleanup.unregister();
 652
 653   Context.setExternalSource(Source);
 654
 655   // Create an AST consumer, even though it isn't used.
 656   AST->Consumer.reset(new ASTConsumer);
 657
 658   // Create a semantic analysis object and tell the AST reader about it.
 659   AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
 660   AST->TheSema->Initialize();
 661   ReaderPtr->InitializeSema(*AST->TheSema);
 662
 663   return AST.take();
 664 }
 665
 666 namespace {
 667
 668 /// \brief Preprocessor callback class that updates a hash value with the names
 669 /// of all macros that have been defined by the translation unit.
 670 class MacroDefinitionTrackerPPCallbacks : public PPCallbacks {
 671   unsigned &Hash;
 672
 673 public:
 674   explicit MacroDefinitionTrackerPPCallbacks(unsigned &Hash) : Hash(Hash) { }
 675
 676   virtual void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI) {
 677     Hash = llvm::HashString(MacroNameTok.getIdentifierInfo()->getName(), Hash);
 678   }
 679 };
 680
 681 /// \brief Add the given declaration to the hash of all top-level entities.
 682 void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
 683   if (!D)
 684     return;
 685
 686   DeclContext *DC = D->getDeclContext();
 687   if (!DC)
 688     return;
 689
 690   if (!(DC->isTranslationUnit() || DC->getLookupParent()->isTranslationUnit()))
 691     return;
 692
 693   if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
 694     if (ND->getIdentifier())
 695       Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
 696     else if (DeclarationName Name = ND->getDeclName()) {
 697       std::string NameStr = Name.getAsString();
 698       Hash = llvm::HashString(NameStr, Hash);
 699     }
 700     return;
 701   }
 702
 703   if (ObjCForwardProtocolDecl *Forward
 704       = dyn_cast<ObjCForwardProtocolDecl>(D)) {
 705     for (ObjCForwardProtocolDecl::protocol_iterator
 706          P = Forward->protocol_begin(),
 707          PEnd = Forward->protocol_end();
 708          P != PEnd; ++P)
 709       AddTopLevelDeclarationToHash(*P, Hash);
 710     return;
 711   }
 712
 713   if (ObjCClassDecl *Class = llvm::dyn_cast<ObjCClassDecl>(D)) {
 714     for (ObjCClassDecl::iterator I = Class->begin(), IEnd = Class->end();
 715          I != IEnd; ++I)
 716       AddTopLevelDeclarationToHash(I->getInterface(), Hash);
 717     return;
 718   }
 719 }
 720
 721 class TopLevelDeclTrackerConsumer : public ASTConsumer {
 722   ASTUnit &Unit;
 723   unsigned &Hash;
 724
 725 public:
 726   TopLevelDeclTrackerConsumer(ASTUnit &_Unit, unsigned &Hash)
 727     : Unit(_Unit), Hash(Hash) {
 728     Hash = 0;
 729   }
 730
 731   void HandleTopLevelDecl(DeclGroupRef D) {
 732     for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
 733       Decl *D = *it;
 734       // FIXME: Currently ObjC method declarations are incorrectly being
 735       // reported as top-level declarations, even though their DeclContext
 736       // is the containing ObjC @interface/@implementation.  This is a
 737       // fundamental problem in the parser right now.
 738       if (isa<ObjCMethodDecl>(D))
 739         continue;
 740
 741       AddTopLevelDeclarationToHash(D, Hash);
 742       Unit.addTopLevelDecl(D);
 743     }
 744   }
 745
 746   // We're not interested in "interesting" decls.
 747   void HandleInterestingDecl(DeclGroupRef) {}
 748 };
 749
 750 class TopLevelDeclTrackerAction : public ASTFrontendAction {
 751 public:
 752   ASTUnit &Unit;
 753
 754   virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
 755                                          llvm::StringRef InFile) {
 756     CI.getPreprocessor().addPPCallbacks(
 757      new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
 758     return new TopLevelDeclTrackerConsumer(Unit,
 759                                            Unit.getCurrentTopLevelHashValue());
 760   }
 761
 762 public:
 763   TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
 764
 765   virtual bool hasCodeCompletionSupport() const { return false; }
 766   virtual bool usesCompleteTranslationUnit()  {
 767     return Unit.isCompleteTranslationUnit();
 768   }
 769 };
 770
 771 class PrecompilePreambleConsumer : public PCHGenerator,
 772                                    public ASTSerializationListener {
 773   ASTUnit &Unit;
 774   unsigned &Hash;
 775   std::vector<Decl *> TopLevelDecls;
 776
 777 public:
 778   PrecompilePreambleConsumer(ASTUnit &Unit,
 779                              const Preprocessor &PP, bool Chaining,
 780                              const char *isysroot, llvm::raw_ostream *Out)
 781     : PCHGenerator(PP, "", Chaining, isysroot, Out), Unit(Unit),
 782       Hash(Unit.getCurrentTopLevelHashValue()) {
 783     Hash = 0;
 784   }
 785
 786   virtual void HandleTopLevelDecl(DeclGroupRef D) {
 787     for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
 788       Decl *D = *it;
 789       // FIXME: Currently ObjC method declarations are incorrectly being
 790       // reported as top-level declarations, even though their DeclContext
 791       // is the containing ObjC @interface/@implementation.  This is a
 792       // fundamental problem in the parser right now.
 793       if (isa<ObjCMethodDecl>(D))
 794         continue;
 795       AddTopLevelDeclarationToHash(D, Hash);
 796       TopLevelDecls.push_back(D);
 797     }
 798   }
 799
 800   virtual void HandleTranslationUnit(ASTContext &Ctx) {
 801     PCHGenerator::HandleTranslationUnit(Ctx);
 802     if (!Unit.getDiagnostics().hasErrorOccurred()) {
 803       // Translate the top-level declarations we captured during
 804       // parsing into declaration IDs in the precompiled
 805       // preamble. This will allow us to deserialize those top-level
 806       // declarations when requested.
 807       for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
 808         Unit.addTopLevelDeclFromPreamble(
 809                                       getWriter().getDeclID(TopLevelDecls[I]));
 810     }
 811   }
 812
 813   virtual void SerializedPreprocessedEntity(PreprocessedEntity *Entity,
 814                                             uint64_t Offset) {
 815     Unit.addPreprocessedEntityFromPreamble(Offset);
 816   }
 817
 818   virtual ASTSerializationListener *GetASTSerializationListener() {
 819     return this;
 820   }
 821 };
 822
 823 class PrecompilePreambleAction : public ASTFrontendAction {
 824   ASTUnit &Unit;
 825
 826 public:
 827   explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
 828
 829   virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
 830                                          llvm::StringRef InFile) {
 831     std::string Sysroot;
 832     std::string OutputFile;
 833     llvm::raw_ostream *OS = 0;
 834     bool Chaining;
 835     if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
 836                                                        OutputFile,
 837                                                        OS, Chaining))
 838       return 0;
 839
 840     const char *isysroot = CI.getFrontendOpts().RelocatablePCH ?
 841                              Sysroot.c_str() : 0;
 842     CI.getPreprocessor().addPPCallbacks(
 843      new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
 844     return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Chaining,
 845                                           isysroot, OS);
 846   }
 847
 848   virtual bool hasCodeCompletionSupport() const { return false; }
 849   virtual bool hasASTFileSupport() const { return false; }
 850   virtual bool usesCompleteTranslationUnit() { return false; }
 851 };
 852
 853 }
 854
 855 /// Parse the source file into a translation unit using the given compiler
 856 /// invocation, replacing the current translation unit.
 857 ///
 858 /// \returns True if a failure occurred that causes the ASTUnit not to
 859 /// contain any translation-unit information, false otherwise.
 860 bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
 861   delete SavedMainFileBuffer;
 862   SavedMainFileBuffer = 0;
 863
 864   if (!Invocation) {
 865     delete OverrideMainBuffer;
 866     return true;
 867   }
 868
 869   // Create the compiler instance to use for building the AST.
 870   llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
 871
 872   // Recover resources if we crash before exiting this method.
 873   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
 874     CICleanup(Clang.get());
 875
 876   Clang->setInvocation(&*Invocation);
 877   OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
 878
 879   // Set up diagnostics, capturing any diagnostics that would
 880   // otherwise be dropped.
 881   Clang->setDiagnostics(&getDiagnostics());
 882
 883   // Create the target instance.
 884   Clang->getTargetOpts().Features = TargetFeatures;
 885   Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
 886                    Clang->getTargetOpts()));
 887   if (!Clang->hasTarget()) {
 888     delete OverrideMainBuffer;
 889     return true;
 890   }
 891
 892   // Inform the target of the language options.
 893   //
 894   // FIXME: We shouldn't need to do this, the target should be immutable once
 895   // created. This complexity should be lifted elsewhere.
 896   Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
 897
 898   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
 899          "Invocation must have exactly one source file!");
 900   assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
 901          "FIXME: AST inputs not yet supported here!");
 902   assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
 903          "IR inputs not support here!");
 904
 905   // Configure the various subsystems.
 906   // FIXME: Should we retain the previous file manager?
 907   FileSystemOpts = Clang->getFileSystemOpts();
 908   FileMgr = new FileManager(FileSystemOpts);
 909   SourceMgr = new SourceManager(getDiagnostics(), *FileMgr);
 910   TheSema.reset();
 911   Ctx = 0;
 912   PP = 0;
 913
 914   // Clear out old caches and data.
 915   TopLevelDecls.clear();
 916   PreprocessedEntities.clear();
 917   CleanTemporaryFiles();
 918   PreprocessedEntitiesByFile.clear();
 919
 920   if (!OverrideMainBuffer) {
 921     StoredDiagnostics.erase(
 922                     StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
 923                             StoredDiagnostics.end());
 924     TopLevelDeclsInPreamble.clear();
 925     PreprocessedEntitiesInPreamble.clear();
 926   }
 927
 928   // Create a file manager object to provide access to and cache the filesystem.
 929   Clang->setFileManager(&getFileManager());
 930
 931   // Create the source manager.
 932   Clang->setSourceManager(&getSourceManager());
 933
 934   // If the main file has been overridden due to the use of a preamble,
 935   // make that override happen and introduce the preamble.
 936   PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
 937   PreprocessorOpts.DetailedRecordIncludesNestedMacroExpansions
 938     = NestedMacroExpansions;
 939   std::string PriorImplicitPCHInclude;
 940   if (OverrideMainBuffer) {
 941     PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
 942     PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
 943     PreprocessorOpts.PrecompiledPreambleBytes.second
 944                                                     = PreambleEndsAtStartOfLine;
 945     PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
 946     PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
 947     PreprocessorOpts.DisablePCHValidation = true;
 948
 949     // The stored diagnostic has the old source manager in it; update
 950     // the locations to refer into the new source manager. Since we've
 951     // been careful to make sure that the source manager's state
 952     // before and after are identical, so that we can reuse the source
 953     // location itself.
 954     for (unsigned I = NumStoredDiagnosticsFromDriver,
 955                   N = StoredDiagnostics.size();
 956          I < N; ++I) {
 957       FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
 958                         getSourceManager());
 959       StoredDiagnostics[I].setLocation(Loc);
 960     }
 961
 962     // Keep track of the override buffer;
 963     SavedMainFileBuffer = OverrideMainBuffer;
 964   } else {
 965     PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
 966     PreprocessorOpts.PrecompiledPreambleBytes.second = false;
 967   }
 968
 969   llvm::OwningPtr<TopLevelDeclTrackerAction> Act(
 970     new TopLevelDeclTrackerAction(*this));
 971
 972   // Recover resources if we crash before exiting this method.
 973   llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
 974     ActCleanup(Act.get());
 975
 976   if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
 977                             Clang->getFrontendOpts().Inputs[0].first))
 978     goto error;
 979
 980   Act->Execute();
 981
 982   // Steal the created target, context, and preprocessor.
 983   TheSema.reset(Clang->takeSema());
 984   Consumer.reset(Clang->takeASTConsumer());
 985   Ctx = &Clang->getASTContext();
 986   PP = &Clang->getPreprocessor();
 987   Clang->setSourceManager(0);
 988   Clang->setFileManager(0);
 989   Target = &Clang->getTarget();
 990
 991   Act->EndSourceFile();
 992
 993   // Remove the overridden buffer we used for the preamble.
 994   if (OverrideMainBuffer) {
 995     PreprocessorOpts.eraseRemappedFile(
 996                                PreprocessorOpts.remapped_file_buffer_end() - 1);
 997     PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
 998   }
 999
1000   return false;
1001
1002 error:
1003   // Remove the overridden buffer we used for the preamble.
1004   if (OverrideMainBuffer) {
1005     PreprocessorOpts.eraseRemappedFile(
1006                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1007     PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
1008     delete OverrideMainBuffer;
1009     SavedMainFileBuffer = 0;
1010   }
1011
1012   StoredDiagnostics.clear();
1013   return true;
1014 }
1015
1016 /// \brief Simple function to retrieve a path for a preamble precompiled header.
1017 static std::string GetPreamblePCHPath() {
1018   // FIXME: This is lame; sys::Path should provide this function (in particular,
1019   // it should know how to find the temporary files dir).
1020   // FIXME: This is really lame. I copied this code from the Driver!
1021   // FIXME: This is a hack so that we can override the preamble file during
1022   // crash-recovery testing, which is the only case where the preamble files
1023   // are not necessarily cleaned up.
1024   const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
1025   if (TmpFile)
1026     return TmpFile;
1027
1028   std::string Error;
1029   const char *TmpDir = ::getenv("TMPDIR");
1030   if (!TmpDir)
1031     TmpDir = ::getenv("TEMP");
1032   if (!TmpDir)
1033     TmpDir = ::getenv("TMP");
1034 #ifdef LLVM_ON_WIN32
1035   if (!TmpDir)
1036     TmpDir = ::getenv("USERPROFILE");
1037 #endif
1038   if (!TmpDir)
1039     TmpDir = "/tmp";
1040   llvm::sys::Path P(TmpDir);
1041   P.createDirectoryOnDisk(true);
1042   P.appendComponent("preamble");
1043   P.appendSuffix("pch");
1044   if (P.createTemporaryFileOnDisk())
1045     return std::string();
1046
1047   return P.str();
1048 }
1049
1050 /// \brief Compute the preamble for the main file, providing the source buffer
1051 /// that corresponds to the main file along with a pair (bytes, start-of-line)
1052 /// that describes the preamble.
1053 std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
1054 ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
1055                          unsigned MaxLines, bool &CreatedBuffer) {
1056   FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
1057   PreprocessorOptions &PreprocessorOpts = Invocation.getPreprocessorOpts();
1058   CreatedBuffer = false;
1059
1060   // Try to determine if the main file has been remapped, either from the
1061   // command line (to another file) or directly through the compiler invocation
1062   // (to a memory buffer).
1063   llvm::MemoryBuffer *Buffer = 0;
1064   llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1065   if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
1066     // Check whether there is a file-file remapping of the main file
1067     for (PreprocessorOptions::remapped_file_iterator
1068           M = PreprocessorOpts.remapped_file_begin(),
1069           E = PreprocessorOpts.remapped_file_end();
1070          M != E;
1071          ++M) {
1072       llvm::sys::PathWithStatus MPath(M->first);
1073       if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1074         if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1075           // We found a remapping. Try to load the resulting, remapped source.
1076           if (CreatedBuffer) {
1077             delete Buffer;
1078             CreatedBuffer = false;
1079           }
1080
1081           Buffer = getBufferForFile(M->second);
1082           if (!Buffer)
1083             return std::make_pair((llvm::MemoryBuffer*)0,
1084                                   std::make_pair(0, true));
1085           CreatedBuffer = true;
1086         }
1087       }
1088     }
1089
1090     // Check whether there is a file-buffer remapping. It supercedes the
1091     // file-file remapping.
1092     for (PreprocessorOptions::remapped_file_buffer_iterator
1093            M = PreprocessorOpts.remapped_file_buffer_begin(),
1094            E = PreprocessorOpts.remapped_file_buffer_end();
1095          M != E;
1096          ++M) {
1097       llvm::sys::PathWithStatus MPath(M->first);
1098       if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1099         if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1100           // We found a remapping.
1101           if (CreatedBuffer) {
1102             delete Buffer;
1103             CreatedBuffer = false;
1104           }
1105
1106           Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
1107         }
1108       }
1109     }
1110   }
1111
1112   // If the main source file was not remapped, load it now.
1113   if (!Buffer) {
1114     Buffer = getBufferForFile(FrontendOpts.Inputs[0].second);
1115     if (!Buffer)
1116       return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
1117
1118     CreatedBuffer = true;
1119   }
1120
1121   return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer, MaxLines));
1122 }
1123
1124 static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
1125                                                       unsigned NewSize,
1126                                                       llvm::StringRef NewName) {
1127   llvm::MemoryBuffer *Result
1128     = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
1129   memcpy(const_cast<char*>(Result->getBufferStart()),
1130          Old->getBufferStart(), Old->getBufferSize());
1131   memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
1132          ' ', NewSize - Old->getBufferSize() - 1);
1133   const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
1134
1135   return Result;
1136 }
1137
1138 /// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
1139 /// the source file.
1140 ///
1141 /// This routine will compute the preamble of the main source file. If a
1142 /// non-trivial preamble is found, it will precompile that preamble into a
1143 /// precompiled header so that the precompiled preamble can be used to reduce
1144 /// reparsing time. If a precompiled preamble has already been constructed,
1145 /// this routine will determine if it is still valid and, if so, avoid
1146 /// rebuilding the precompiled preamble.
1147 ///
1148 /// \param AllowRebuild When true (the default), this routine is
1149 /// allowed to rebuild the precompiled preamble if it is found to be
1150 /// out-of-date.
1151 ///
1152 /// \param MaxLines When non-zero, the maximum number of lines that
1153 /// can occur within the preamble.
1154 ///
1155 /// \returns If the precompiled preamble can be used, returns a newly-allocated
1156 /// buffer that should be used in place of the main file when doing so.
1157 /// Otherwise, returns a NULL pointer.
1158 llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
1159                               const CompilerInvocation &PreambleInvocationIn,
1160                                                            bool AllowRebuild,
1161                                                            unsigned MaxLines) {
1162
1163   llvm::IntrusiveRefCntPtr<CompilerInvocation>
1164     PreambleInvocation(new CompilerInvocation(PreambleInvocationIn));
1165   FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();
1166   PreprocessorOptions &PreprocessorOpts
1167     = PreambleInvocation->getPreprocessorOpts();
1168
1169   bool CreatedPreambleBuffer = false;
1170   std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
1171     = ComputePreamble(*PreambleInvocation, MaxLines, CreatedPreambleBuffer);
1172
1173   // If ComputePreamble() Take ownership of the
1174   llvm::OwningPtr<llvm::MemoryBuffer> OwnedPreambleBuffer;
1175   if (CreatedPreambleBuffer)
1176     OwnedPreambleBuffer.reset(NewPreamble.first);
1177
1178   if (!NewPreamble.second.first) {
1179     // We couldn't find a preamble in the main source. Clear out the current
1180     // preamble, if we have one. It's obviously no good any more.
1181     Preamble.clear();
1182     if (!PreambleFile.empty()) {
1183       llvm::sys::Path(PreambleFile).eraseFromDisk();
1184       PreambleFile.clear();
1185     }
1186
1187     // The next time we actually see a preamble, precompile it.
1188     PreambleRebuildCounter = 1;
1189     return 0;
1190   }
1191
1192   if (!Preamble.empty()) {
1193     // We've previously computed a preamble. Check whether we have the same
1194     // preamble now that we did before, and that there's enough space in
1195     // the main-file buffer within the precompiled preamble to fit the
1196     // new main file.
1197     if (Preamble.size() == NewPreamble.second.first &&
1198         PreambleEndsAtStartOfLine == NewPreamble.second.second &&
1199         NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
1200         memcmp(&Preamble[0], NewPreamble.first->getBufferStart(),
1201                NewPreamble.second.first) == 0) {
1202       // The preamble has not changed. We may be able to re-use the precompiled
1203       // preamble.
1204
1205       // Check that none of the files used by the preamble have changed.
1206       bool AnyFileChanged = false;
1207
1208       // First, make a record of those files that have been overridden via
1209       // remapping or unsaved_files.
1210       llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
1211       for (PreprocessorOptions::remapped_file_iterator
1212                 R = PreprocessorOpts.remapped_file_begin(),
1213              REnd = PreprocessorOpts.remapped_file_end();
1214            !AnyFileChanged && R != REnd;
1215            ++R) {
1216         struct stat StatBuf;
1217         if (FileMgr->getNoncachedStatValue(R->second, StatBuf)) {
1218           // If we can't stat the file we're remapping to, assume that something
1219           // horrible happened.
1220           AnyFileChanged = true;
1221           break;
1222         }
1223
1224         OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
1225                                                    StatBuf.st_mtime);
1226       }
1227       for (PreprocessorOptions::remapped_file_buffer_iterator
1228                 R = PreprocessorOpts.remapped_file_buffer_begin(),
1229              REnd = PreprocessorOpts.remapped_file_buffer_end();
1230            !AnyFileChanged && R != REnd;
1231            ++R) {
1232         // FIXME: Should we actually compare the contents of file->buffer
1233         // remappings?
1234         OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
1235                                                    0);
1236       }
1237
1238       // Check whether anything has changed.
1239       for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
1240              F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1241            !AnyFileChanged && F != FEnd;
1242            ++F) {
1243         llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1244           = OverriddenFiles.find(F->first());
1245         if (Overridden != OverriddenFiles.end()) {
1246           // This file was remapped; check whether the newly-mapped file
1247           // matches up with the previous mapping.
1248           if (Overridden->second != F->second)
1249             AnyFileChanged = true;
1250           continue;
1251         }
1252
1253         // The file was not remapped; check whether it has changed on disk.
1254         struct stat StatBuf;
1255         if (FileMgr->getNoncachedStatValue(F->first(), StatBuf)) {
1256           // If we can't stat the file, assume that something horrible happened.
1257           AnyFileChanged = true;
1258         } else if (StatBuf.st_size != F->second.first ||
1259                    StatBuf.st_mtime != F->second.second)
1260           AnyFileChanged = true;
1261       }
1262
1263       if (!AnyFileChanged) {
1264         // Okay! We can re-use the precompiled preamble.
1265
1266         // Set the state of the diagnostic object to mimic its state
1267         // after parsing the preamble.
1268         // FIXME: This won't catch any #pragma push warning changes that
1269         // have occurred in the preamble.
1270         getDiagnostics().Reset();
1271         ProcessWarningOptions(getDiagnostics(),
1272                               PreambleInvocation->getDiagnosticOpts());
1273         getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1274         if (StoredDiagnostics.size() > NumStoredDiagnosticsInPreamble)
1275           StoredDiagnostics.erase(
1276             StoredDiagnostics.begin() + NumStoredDiagnosticsInPreamble,
1277                                   StoredDiagnostics.end());
1278
1279         // Create a version of the main file buffer that is padded to
1280         // buffer size we reserved when creating the preamble.
1281         return CreatePaddedMainFileBuffer(NewPreamble.first,
1282                                           PreambleReservedSize,
1283                                           FrontendOpts.Inputs[0].second);
1284       }
1285     }
1286
1287     // If we aren't allowed to rebuild the precompiled preamble, just
1288     // return now.
1289     if (!AllowRebuild)
1290       return 0;
1291
1292     // We can't reuse the previously-computed preamble. Build a new one.
1293     Preamble.clear();
1294     llvm::sys::Path(PreambleFile).eraseFromDisk();
1295     PreambleRebuildCounter = 1;
1296   } else if (!AllowRebuild) {
1297     // We aren't allowed to rebuild the precompiled preamble; just
1298     // return now.
1299     return 0;
1300   }
1301
1302   // If the preamble rebuild counter > 1, it's because we previously
1303   // failed to build a preamble and we're not yet ready to try
1304   // again. Decrement the counter and return a failure.
1305   if (PreambleRebuildCounter > 1) {
1306     --PreambleRebuildCounter;
1307     return 0;
1308   }
1309
1310   // Create a temporary file for the precompiled preamble. In rare
1311   // circumstances, this can fail.
1312   std::string PreamblePCHPath = GetPreamblePCHPath();
1313   if (PreamblePCHPath.empty()) {
1314     // Try again next time.
1315     PreambleRebuildCounter = 1;
1316     return 0;
1317   }
1318
1319   // We did not previously compute a preamble, or it can't be reused anyway.
1320   SimpleTimer PreambleTimer(WantTiming);
1321   PreambleTimer.setOutput("Precompiling preamble");
1322
1323   // Create a new buffer that stores the preamble. The buffer also contains
1324   // extra space for the original contents of the file (which will be present
1325   // when we actually parse the file) along with more room in case the file
1326   // grows.
1327   PreambleReservedSize = NewPreamble.first->getBufferSize();
1328   if (PreambleReservedSize < 4096)
1329     PreambleReservedSize = 8191;
1330   else
1331     PreambleReservedSize *= 2;
1332
1333   // Save the preamble text for later; we'll need to compare against it for
1334   // subsequent reparses.
1335   Preamble.assign(NewPreamble.first->getBufferStart(),
1336                   NewPreamble.first->getBufferStart()
1337                                                   + NewPreamble.second.first);
1338   PreambleEndsAtStartOfLine = NewPreamble.second.second;
1339
1340   delete PreambleBuffer;
1341   PreambleBuffer
1342     = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1343                                                 FrontendOpts.Inputs[0].second);
1344   memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1345          NewPreamble.first->getBufferStart(), Preamble.size());
1346   memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1347          ' ', PreambleReservedSize - Preamble.size() - 1);
1348   const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1349
1350   // Remap the main source file to the preamble buffer.
1351   llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1352   PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1353
1354   // Tell the compiler invocation to generate a temporary precompiled header.
1355   FrontendOpts.ProgramAction = frontend::GeneratePCH;
1356   FrontendOpts.ChainedPCH = true;
1357   // FIXME: Generate the precompiled header into memory?
1358   FrontendOpts.OutputFile = PreamblePCHPath;
1359   PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1360   PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1361
1362   // Create the compiler instance to use for building the precompiled preamble.
1363   llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1364
1365   // Recover resources if we crash before exiting this method.
1366   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1367     CICleanup(Clang.get());
1368
1369   Clang->setInvocation(&*PreambleInvocation);
1370   OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
1371
1372   // Set up diagnostics, capturing all of the diagnostics produced.
1373   Clang->setDiagnostics(&getDiagnostics());
1374
1375   // Create the target instance.
1376   Clang->getTargetOpts().Features = TargetFeatures;
1377   Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1378                                                Clang->getTargetOpts()));
1379   if (!Clang->hasTarget()) {
1380     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1381     Preamble.clear();
1382     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1383     PreprocessorOpts.eraseRemappedFile(
1384                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1385     return 0;
1386   }
1387
1388   // Inform the target of the language options.
1389   //
1390   // FIXME: We shouldn't need to do this, the target should be immutable once
1391   // created. This complexity should be lifted elsewhere.
1392   Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1393
1394   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1395          "Invocation must have exactly one source file!");
1396   assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
1397          "FIXME: AST inputs not yet supported here!");
1398   assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1399          "IR inputs not support here!");
1400
1401   // Clear out old caches and data.
1402   getDiagnostics().Reset();
1403   ProcessWarningOptions(getDiagnostics(), Clang->getDiagnosticOpts());
1404   StoredDiagnostics.erase(
1405                     StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
1406                           StoredDiagnostics.end());
1407   TopLevelDecls.clear();
1408   TopLevelDeclsInPreamble.clear();
1409   PreprocessedEntities.clear();
1410   PreprocessedEntitiesInPreamble.clear();
1411
1412   // Create a file manager object to provide access to and cache the filesystem.
1413   Clang->setFileManager(new FileManager(Clang->getFileSystemOpts()));
1414
1415   // Create the source manager.
1416   Clang->setSourceManager(new SourceManager(getDiagnostics(),
1417                                             Clang->getFileManager()));
1418
1419   llvm::OwningPtr<PrecompilePreambleAction> Act;
1420   Act.reset(new PrecompilePreambleAction(*this));
1421   if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
1422                             Clang->getFrontendOpts().Inputs[0].first)) {
1423     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1424     Preamble.clear();
1425     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1426     PreprocessorOpts.eraseRemappedFile(
1427                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1428     return 0;
1429   }
1430
1431   Act->Execute();
1432   Act->EndSourceFile();
1433
1434   if (Diagnostics->hasErrorOccurred()) {
1435     // There were errors parsing the preamble, so no precompiled header was
1436     // generated. Forget that we even tried.
1437     // FIXME: Should we leave a note for ourselves to try again?
1438     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1439     Preamble.clear();
1440     TopLevelDeclsInPreamble.clear();
1441     PreprocessedEntities.clear();
1442     PreprocessedEntitiesInPreamble.clear();
1443     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1444     PreprocessorOpts.eraseRemappedFile(
1445                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1446     return 0;
1447   }
1448
1449   // Keep track of the preamble we precompiled.
1450   PreambleFile = FrontendOpts.OutputFile;
1451   NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1452   NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1453
1454   // Keep track of all of the files that the source manager knows about,
1455   // so we can verify whether they have changed or not.
1456   FilesInPreamble.clear();
1457   SourceManager &SourceMgr = Clang->getSourceManager();
1458   const llvm::MemoryBuffer *MainFileBuffer
1459     = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1460   for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1461                                      FEnd = SourceMgr.fileinfo_end();
1462        F != FEnd;
1463        ++F) {
1464     const FileEntry *File = F->second->OrigEntry;
1465     if (!File || F->second->getRawBuffer() == MainFileBuffer)
1466       continue;
1467
1468     FilesInPreamble[File->getName()]
1469       = std::make_pair(F->second->getSize(), File->getModificationTime());
1470   }
1471
1472   PreambleRebuildCounter = 1;
1473   PreprocessorOpts.eraseRemappedFile(
1474                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1475
1476   // If the hash of top-level entities differs from the hash of the top-level
1477   // entities the last time we rebuilt the preamble, clear out the completion
1478   // cache.
1479   if (CurrentTopLevelHashValue != PreambleTopLevelHashValue) {
1480     CompletionCacheTopLevelHashValue = 0;
1481     PreambleTopLevelHashValue = CurrentTopLevelHashValue;
1482   }
1483
1484   return CreatePaddedMainFileBuffer(NewPreamble.first,
1485                                     PreambleReservedSize,
1486                                     FrontendOpts.Inputs[0].second);
1487 }
1488
1489 void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1490   std::vector<Decl *> Resolved;
1491   Resolved.reserve(TopLevelDeclsInPreamble.size());
1492   ExternalASTSource &Source = *getASTContext().getExternalSource();
1493   for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1494     // Resolve the declaration ID to an actual declaration, possibly
1495     // deserializing the declaration in the process.
1496     Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1497     if (D)
1498       Resolved.push_back(D);
1499   }
1500   TopLevelDeclsInPreamble.clear();
1501   TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1502 }
1503
1504 void ASTUnit::RealizePreprocessedEntitiesFromPreamble() {
1505   if (!PP)
1506     return;
1507
1508   PreprocessingRecord *PPRec = PP->getPreprocessingRecord();
1509   if (!PPRec)
1510     return;
1511
1512   ExternalPreprocessingRecordSource *External = PPRec->getExternalSource();
1513   if (!External)
1514     return;
1515
1516   for (unsigned I = 0, N = PreprocessedEntitiesInPreamble.size(); I != N; ++I) {
1517     if (PreprocessedEntity *PE
1518           = External->ReadPreprocessedEntityAtOffset(
1519                                             PreprocessedEntitiesInPreamble[I]))
1520       PreprocessedEntities.push_back(PE);
1521   }
1522
1523   if (PreprocessedEntities.empty())
1524     return;
1525
1526   PreprocessedEntities.insert(PreprocessedEntities.end(),
1527                               PPRec->begin(true), PPRec->end(true));
1528 }
1529
1530 ASTUnit::pp_entity_iterator ASTUnit::pp_entity_begin() {
1531   if (!PreprocessedEntitiesInPreamble.empty() &&
1532       PreprocessedEntities.empty())
1533     RealizePreprocessedEntitiesFromPreamble();
1534
1535   if (PreprocessedEntities.empty())
1536     if (PreprocessingRecord *PPRec = PP->getPreprocessingRecord())
1537       return PPRec->begin(true);
1538
1539   return PreprocessedEntities.begin();
1540 }
1541
1542 ASTUnit::pp_entity_iterator ASTUnit::pp_entity_end() {
1543   if (!PreprocessedEntitiesInPreamble.empty() &&
1544       PreprocessedEntities.empty())
1545     RealizePreprocessedEntitiesFromPreamble();
1546
1547   if (PreprocessedEntities.empty())
1548     if (PreprocessingRecord *PPRec = PP->getPreprocessingRecord())
1549       return PPRec->end(true);
1550
1551   return PreprocessedEntities.end();
1552 }
1553
1554 unsigned ASTUnit::getMaxPCHLevel() const {
1555   if (!getOnlyLocalDecls())
1556     return Decl::MaxPCHLevel;
1557
1558   return 0;
1559 }
1560
1561 llvm::StringRef ASTUnit::getMainFileName() const {
1562   return Invocation->getFrontendOpts().Inputs[0].second;
1563 }
1564
1565 ASTUnit *ASTUnit::create(CompilerInvocation *CI,
1566                          llvm::IntrusiveRefCntPtr<Diagnostic> Diags) {
1567   llvm::OwningPtr<ASTUnit> AST;
1568   AST.reset(new ASTUnit(false));
1569   ConfigureDiags(Diags, 0, 0, *AST, /*CaptureDiagnostics=*/false);
1570   AST->Diagnostics = Diags;
1571   AST->Invocation = CI;
1572   AST->FileSystemOpts = CI->getFileSystemOpts();
1573   AST->FileMgr = new FileManager(AST->FileSystemOpts);
1574   AST->SourceMgr = new SourceManager(*Diags, *AST->FileMgr);
1575
1576   return AST.take();
1577 }
1578
1579 ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(CompilerInvocation *CI,
1580                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1581                                              ASTFrontendAction *Action) {
1582   assert(CI && "A CompilerInvocation is required");
1583
1584   // Create the AST unit.
1585   llvm::OwningPtr<ASTUnit> AST;
1586   AST.reset(new ASTUnit(false));
1587   ConfigureDiags(Diags, 0, 0, *AST, /*CaptureDiagnostics*/false);
1588   AST->Diagnostics = Diags;
1589   AST->OnlyLocalDecls = false;
1590   AST->CaptureDiagnostics = false;
1591   AST->CompleteTranslationUnit = Action ? Action->usesCompleteTranslationUnit()
1592                                         : true;
1593   AST->ShouldCacheCodeCompletionResults = false;
1594   AST->Invocation = CI;
1595
1596   // Recover resources if we crash before exiting this method.
1597   llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1598     ASTUnitCleanup(AST.get());
1599   llvm::CrashRecoveryContextCleanupRegistrar<Diagnostic,
1600     llvm::CrashRecoveryContextReleaseRefCleanup<Diagnostic> >
1601     DiagCleanup(Diags.getPtr());
1602
1603   // We'll manage file buffers ourselves.
1604   CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1605   CI->getFrontendOpts().DisableFree = false;
1606   ProcessWarningOptions(AST->getDiagnostics(), CI->getDiagnosticOpts());
1607
1608   // Save the target features.
1609   AST->TargetFeatures = CI->getTargetOpts().Features;
1610
1611   // Create the compiler instance to use for building the AST.
1612   llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1613
1614   // Recover resources if we crash before exiting this method.
1615   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1616     CICleanup(Clang.get());
1617
1618   Clang->setInvocation(CI);
1619   AST->OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
1620
1621   // Set up diagnostics, capturing any diagnostics that would
1622   // otherwise be dropped.
1623   Clang->setDiagnostics(&AST->getDiagnostics());
1624
1625   // Create the target instance.
1626   Clang->getTargetOpts().Features = AST->TargetFeatures;
1627   Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1628                    Clang->getTargetOpts()));
1629   if (!Clang->hasTarget())
1630     return 0;
1631
1632   // Inform the target of the language options.
1633   //
1634   // FIXME: We shouldn't need to do this, the target should be immutable once
1635   // created. This complexity should be lifted elsewhere.
1636   Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1637
1638   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1639          "Invocation must have exactly one source file!");
1640   assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
1641          "FIXME: AST inputs not yet supported here!");
1642   assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1643          "IR inputs not supported here!");
1644
1645   // Configure the various subsystems.
1646   AST->FileSystemOpts = Clang->getFileSystemOpts();
1647   AST->FileMgr = new FileManager(AST->FileSystemOpts);
1648   AST->SourceMgr = new SourceManager(AST->getDiagnostics(), *AST->FileMgr);
1649   AST->TheSema.reset();
1650   AST->Ctx = 0;
1651   AST->PP = 0;
1652
1653   // Create a file manager object to provide access to and cache the filesystem.
1654   Clang->setFileManager(&AST->getFileManager());
1655
1656   // Create the source manager.
1657   Clang->setSourceManager(&AST->getSourceManager());
1658
1659   ASTFrontendAction *Act = Action;
1660
1661   llvm::OwningPtr<TopLevelDeclTrackerAction> TrackerAct;
1662   if (!Act) {
1663     TrackerAct.reset(new TopLevelDeclTrackerAction(*AST));
1664     Act = TrackerAct.get();
1665   }
1666
1667   // Recover resources if we crash before exiting this method.
1668   llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1669     ActCleanup(TrackerAct.get());
1670
1671   if (!Act->BeginSourceFile(*Clang.get(),
1672                             Clang->getFrontendOpts().Inputs[0].second,
1673                             Clang->getFrontendOpts().Inputs[0].first))
1674     return 0;
1675
1676   Act->Execute();
1677
1678   // Steal the created target, context, and preprocessor.
1679   AST->TheSema.reset(Clang->takeSema());
1680   AST->Consumer.reset(Clang->takeASTConsumer());
1681   AST->Ctx = &Clang->getASTContext();
1682   AST->PP = &Clang->getPreprocessor();
1683   Clang->setSourceManager(0);
1684   Clang->setFileManager(0);
1685   AST->Target = &Clang->getTarget();
1686
1687   Act->EndSourceFile();
1688
1689   return AST.take();
1690 }
1691
1692 bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
1693   if (!Invocation)
1694     return true;
1695
1696   // We'll manage file buffers ourselves.
1697   Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1698   Invocation->getFrontendOpts().DisableFree = false;
1699   ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1700
1701   // Save the target features.
1702   TargetFeatures = Invocation->getTargetOpts().Features;
1703
1704   llvm::MemoryBuffer *OverrideMainBuffer = 0;
1705   if (PrecompilePreamble) {
1706     PreambleRebuildCounter = 2;
1707     OverrideMainBuffer
1708       = getMainBufferWithPrecompiledPreamble(*Invocation);
1709   }
1710
1711   SimpleTimer ParsingTimer(WantTiming);
1712   ParsingTimer.setOutput("Parsing " + getMainFileName());
1713
1714   // Recover resources if we crash before exiting this method.
1715   llvm::CrashRecoveryContextCleanupRegistrar<llvm::MemoryBuffer>
1716     MemBufferCleanup(OverrideMainBuffer);
1717
1718   return Parse(OverrideMainBuffer);
1719 }
1720
1721 ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1722                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1723                                              bool OnlyLocalDecls,
1724                                              bool CaptureDiagnostics,
1725                                              bool PrecompilePreamble,
1726                                              bool CompleteTranslationUnit,
1727                                              bool CacheCodeCompletionResults,
1728                                              bool NestedMacroExpansions) {
1729   // Create the AST unit.
1730   llvm::OwningPtr<ASTUnit> AST;
1731   AST.reset(new ASTUnit(false));
1732   ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
1733   AST->Diagnostics = Diags;
1734   AST->OnlyLocalDecls = OnlyLocalDecls;
1735   AST->CaptureDiagnostics = CaptureDiagnostics;
1736   AST->CompleteTranslationUnit = CompleteTranslationUnit;
1737   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1738   AST->Invocation = CI;
1739   AST->NestedMacroExpansions = NestedMacroExpansions;
1740
1741   // Recover resources if we crash before exiting this method.
1742   llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1743     ASTUnitCleanup(AST.get());
1744   llvm::CrashRecoveryContextCleanupRegistrar<Diagnostic,
1745     llvm::CrashRecoveryContextReleaseRefCleanup<Diagnostic> >
1746     DiagCleanup(Diags.getPtr());
1747
1748   return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
1749 }
1750
1751 ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1752                                       const char **ArgEnd,
1753                                     llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1754                                       llvm::StringRef ResourceFilesPath,
1755                                       bool OnlyLocalDecls,
1756                                       bool CaptureDiagnostics,
1757                                       RemappedFile *RemappedFiles,
1758                                       unsigned NumRemappedFiles,
1759                                       bool RemappedFilesKeepOriginalName,
1760                                       bool PrecompilePreamble,
1761                                       bool CompleteTranslationUnit,
1762                                       bool CacheCodeCompletionResults,
1763                                       bool CXXPrecompilePreamble,
1764                                       bool CXXChainedPCH,
1765                                       bool NestedMacroExpansions) {
1766   if (!Diags.getPtr()) {
1767     // No diagnostics engine was provided, so create our own diagnostics object
1768     // with the default options.
1769     DiagnosticOptions DiagOpts;
1770     Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd - ArgBegin,
1771                                                 ArgBegin);
1772   }
1773
1774   llvm::SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
1775
1776   llvm::IntrusiveRefCntPtr<CompilerInvocation> CI;
1777
1778   {
1779     CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags,
1780                                       StoredDiagnostics);
1781
1782     CI = clang::createInvocationFromCommandLine(
1783                         llvm::ArrayRef<const char *>(ArgBegin, ArgEnd-ArgBegin),
1784                         Diags);
1785     if (!CI)
1786       return 0;
1787   }
1788
1789   // Override any files that need remapping
1790   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1791     FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
1792     if (const llvm::MemoryBuffer *
1793             memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
1794       CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, memBuf);
1795     } else {
1796       const char *fname = fileOrBuf.get<const char *>();
1797       CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, fname);
1798     }
1799   }
1800   CI->getPreprocessorOpts().RemappedFilesKeepOriginalName =
1801                                                   RemappedFilesKeepOriginalName;
1802
1803   // Override the resources path.
1804   CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1805
1806   // Check whether we should precompile the preamble and/or use chained PCH.
1807   // FIXME: This is a temporary hack while we debug C++ chained PCH.
1808   if (CI->getLangOpts().CPlusPlus) {
1809     PrecompilePreamble = PrecompilePreamble && CXXPrecompilePreamble;
1810
1811     if (PrecompilePreamble && !CXXChainedPCH &&
1812         !CI->getPreprocessorOpts().ImplicitPCHInclude.empty())
1813       PrecompilePreamble = false;
1814   }
1815
1816   // Create the AST unit.
1817   llvm::OwningPtr<ASTUnit> AST;
1818   AST.reset(new ASTUnit(false));
1819   ConfigureDiags(Diags, ArgBegin, ArgEnd, *AST, CaptureDiagnostics);
1820   AST->Diagnostics = Diags;
1821
1822   AST->FileSystemOpts = CI->getFileSystemOpts();
1823   AST->FileMgr = new FileManager(AST->FileSystemOpts);
1824   AST->OnlyLocalDecls = OnlyLocalDecls;
1825   AST->CaptureDiagnostics = CaptureDiagnostics;
1826   AST->CompleteTranslationUnit = CompleteTranslationUnit;
1827   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1828   AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
1829   AST->NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1830   AST->StoredDiagnostics.swap(StoredDiagnostics);
1831   AST->Invocation = CI;
1832   AST->NestedMacroExpansions = NestedMacroExpansions;
1833
1834   // Recover resources if we crash before exiting this method.
1835   llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1836     ASTUnitCleanup(AST.get());
1837   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInvocation,
1838     llvm::CrashRecoveryContextReleaseRefCleanup<CompilerInvocation> >
1839     CICleanup(CI.getPtr());
1840   llvm::CrashRecoveryContextCleanupRegistrar<Diagnostic,
1841     llvm::CrashRecoveryContextReleaseRefCleanup<Diagnostic> >
1842     DiagCleanup(Diags.getPtr());
1843
1844   return AST->LoadFromCompilerInvocation(PrecompilePreamble) ? 0 : AST.take();
1845 }
1846
1847 bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1848   if (!Invocation)
1849     return true;
1850
1851   SimpleTimer ParsingTimer(WantTiming);
1852   ParsingTimer.setOutput("Reparsing " + getMainFileName());
1853
1854   // Remap files.
1855   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1856   PPOpts.DisableStatCache = true;
1857   for (PreprocessorOptions::remapped_file_buffer_iterator
1858          R = PPOpts.remapped_file_buffer_begin(),
1859          REnd = PPOpts.remapped_file_buffer_end();
1860        R != REnd;
1861        ++R) {
1862     delete R->second;
1863   }
1864   Invocation->getPreprocessorOpts().clearRemappedFiles();
1865   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1866     FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
1867     if (const llvm::MemoryBuffer *
1868             memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
1869       Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1870                                                         memBuf);
1871     } else {
1872       const char *fname = fileOrBuf.get<const char *>();
1873       Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1874                                                         fname);
1875     }
1876   }
1877
1878   // If we have a preamble file lying around, or if we might try to
1879   // build a precompiled preamble, do so now.
1880   llvm::MemoryBuffer *OverrideMainBuffer = 0;
1881   if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1882     OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
1883
1884   // Clear out the diagnostics state.
1885   if (!OverrideMainBuffer) {
1886     getDiagnostics().Reset();
1887     ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1888   }
1889
1890   // Parse the sources
1891   bool Result = Parse(OverrideMainBuffer);
1892
1893   // If we're caching global code-completion results, and the top-level
1894   // declarations have changed, clear out the code-completion cache.
1895   if (!Result && ShouldCacheCodeCompletionResults &&
1896       CurrentTopLevelHashValue != CompletionCacheTopLevelHashValue)
1897     CacheCodeCompletionResults();
1898
1899   return Result;
1900 }
1901
1902 //----------------------------------------------------------------------------//
1903 // Code completion
1904 //----------------------------------------------------------------------------//
1905
1906 namespace {
1907   /// \brief Code completion consumer that combines the cached code-completion
1908   /// results from an ASTUnit with the code-completion results provided to it,
1909   /// then passes the result on to
1910   class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
1911     unsigned long long NormalContexts;
1912     ASTUnit &AST;
1913     CodeCompleteConsumer &Next;
1914
1915   public:
1916     AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
1917                                   bool IncludeMacros, bool IncludeCodePatterns,
1918                                   bool IncludeGlobals)
1919       : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
1920                              Next.isOutputBinary()), AST(AST), Next(Next)
1921     {
1922       // Compute the set of contexts in which we will look when we don't have
1923       // any information about the specific context.
1924       NormalContexts
1925         = (1LL << (CodeCompletionContext::CCC_TopLevel - 1))
1926         | (1LL << (CodeCompletionContext::CCC_ObjCInterface - 1))
1927         | (1LL << (CodeCompletionContext::CCC_ObjCImplementation - 1))
1928         | (1LL << (CodeCompletionContext::CCC_ObjCIvarList - 1))
1929         | (1LL << (CodeCompletionContext::CCC_Statement - 1))
1930         | (1LL << (CodeCompletionContext::CCC_Expression - 1))
1931         | (1LL << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
1932         | (1LL << (CodeCompletionContext::CCC_DotMemberAccess - 1))
1933         | (1LL << (CodeCompletionContext::CCC_ArrowMemberAccess - 1))
1934         | (1LL << (CodeCompletionContext::CCC_ObjCPropertyAccess - 1))
1935         | (1LL << (CodeCompletionContext::CCC_ObjCProtocolName - 1))
1936         | (1LL << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
1937         | (1LL << (CodeCompletionContext::CCC_Recovery - 1));
1938
1939       if (AST.getASTContext().getLangOptions().CPlusPlus)
1940         NormalContexts |= (1LL << (CodeCompletionContext::CCC_EnumTag - 1))
1941                    | (1LL << (CodeCompletionContext::CCC_UnionTag - 1))
1942                    | (1LL << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
1943     }
1944
1945     virtual void ProcessCodeCompleteResults(Sema &S,
1946                                             CodeCompletionContext Context,
1947                                             CodeCompletionResult *Results,
1948                                             unsigned NumResults);
1949
1950     virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
1951                                            OverloadCandidate *Candidates,
1952                                            unsigned NumCandidates) {
1953       Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
1954     }
1955
1956     virtual CodeCompletionAllocator &getAllocator() {
1957       return Next.getAllocator();
1958     }
1959   };
1960 }
1961
1962 /// \brief Helper function that computes which global names are hidden by the
1963 /// local code-completion results.
1964 static void CalculateHiddenNames(const CodeCompletionContext &Context,
1965                                  CodeCompletionResult *Results,
1966                                  unsigned NumResults,
1967                                  ASTContext &Ctx,
1968                           llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
1969   bool OnlyTagNames = false;
1970   switch (Context.getKind()) {
1971   case CodeCompletionContext::CCC_Recovery:
1972   case CodeCompletionContext::CCC_TopLevel:
1973   case CodeCompletionContext::CCC_ObjCInterface:
1974   case CodeCompletionContext::CCC_ObjCImplementation:
1975   case CodeCompletionContext::CCC_ObjCIvarList:
1976   case CodeCompletionContext::CCC_ClassStructUnion:
1977   case CodeCompletionContext::CCC_Statement:
1978   case CodeCompletionContext::CCC_Expression:
1979   case CodeCompletionContext::CCC_ObjCMessageReceiver:
1980   case CodeCompletionContext::CCC_DotMemberAccess:
1981   case CodeCompletionContext::CCC_ArrowMemberAccess:
1982   case CodeCompletionContext::CCC_ObjCPropertyAccess:
1983   case CodeCompletionContext::CCC_Namespace:
1984   case CodeCompletionContext::CCC_Type:
1985   case CodeCompletionContext::CCC_Name:
1986   case CodeCompletionContext::CCC_PotentiallyQualifiedName:
1987   case CodeCompletionContext::CCC_ParenthesizedExpression:
1988   case CodeCompletionContext::CCC_ObjCSuperclass:
1989     break;
1990
1991   case CodeCompletionContext::CCC_EnumTag:
1992   case CodeCompletionContext::CCC_UnionTag:
1993   case CodeCompletionContext::CCC_ClassOrStructTag:
1994     OnlyTagNames = true;
1995     break;
1996
1997   case CodeCompletionContext::CCC_ObjCProtocolName:
1998   case CodeCompletionContext::CCC_MacroName:
1999   case CodeCompletionContext::CCC_MacroNameUse:
2000   case CodeCompletionContext::CCC_PreprocessorExpression:
2001   case CodeCompletionContext::CCC_PreprocessorDirective:
2002   case CodeCompletionContext::CCC_NaturalLanguage:
2003   case CodeCompletionContext::CCC_SelectorName:
2004   case CodeCompletionContext::CCC_TypeQualifiers:
2005   case CodeCompletionContext::CCC_Other:
2006   case CodeCompletionContext::CCC_OtherWithMacros:
2007   case CodeCompletionContext::CCC_ObjCInstanceMessage:
2008   case CodeCompletionContext::CCC_ObjCClassMessage:
2009   case CodeCompletionContext::CCC_ObjCCategoryName:
2010     // We're looking for nothing, or we're looking for names that cannot
2011     // be hidden.
2012     return;
2013   }
2014
2015   typedef CodeCompletionResult Result;
2016   for (unsigned I = 0; I != NumResults; ++I) {
2017     if (Results[I].Kind != Result::RK_Declaration)
2018       continue;
2019
2020     unsigned IDNS
2021       = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
2022
2023     bool Hiding = false;
2024     if (OnlyTagNames)
2025       Hiding = (IDNS & Decl::IDNS_Tag);
2026     else {
2027       unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
2028                              Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
2029                              Decl::IDNS_NonMemberOperator);
2030       if (Ctx.getLangOptions().CPlusPlus)
2031         HiddenIDNS |= Decl::IDNS_Tag;
2032       Hiding = (IDNS & HiddenIDNS);
2033     }
2034
2035     if (!Hiding)
2036       continue;
2037
2038     DeclarationName Name = Results[I].Declaration->getDeclName();
2039     if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
2040       HiddenNames.insert(Identifier->getName());
2041     else
2042       HiddenNames.insert(Name.getAsString());
2043   }
2044 }
2045
2046
2047 void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
2048                                             CodeCompletionContext Context,
2049                                             CodeCompletionResult *Results,
2050                                             unsigned NumResults) {
2051   // Merge the results we were given with the results we cached.
2052   bool AddedResult = false;
2053   unsigned InContexts
2054     = (Context.getKind() == CodeCompletionContext::CCC_Recovery? NormalContexts
2055                                             : (1 << (Context.getKind() - 1)));
2056
2057   // Contains the set of names that are hidden by "local" completion results.
2058   llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
2059   typedef CodeCompletionResult Result;
2060   llvm::SmallVector<Result, 8> AllResults;
2061   for (ASTUnit::cached_completion_iterator
2062             C = AST.cached_completion_begin(),
2063          CEnd = AST.cached_completion_end();
2064        C != CEnd; ++C) {
2065     // If the context we are in matches any of the contexts we are
2066     // interested in, we'll add this result.
2067     if ((C->ShowInContexts & InContexts) == 0)
2068       continue;
2069
2070     // If we haven't added any results previously, do so now.
2071     if (!AddedResult) {
2072       CalculateHiddenNames(Context, Results, NumResults, S.Context,
2073                            HiddenNames);
2074       AllResults.insert(AllResults.end(), Results, Results + NumResults);
2075       AddedResult = true;
2076     }
2077
2078     // Determine whether this global completion result is hidden by a local
2079     // completion result. If so, skip it.
2080     if (C->Kind != CXCursor_MacroDefinition &&
2081         HiddenNames.count(C->Completion->getTypedText()))
2082       continue;
2083
2084     // Adjust priority based on similar type classes.
2085     unsigned Priority = C->Priority;
2086     CXCursorKind CursorKind = C->Kind;
2087     CodeCompletionString *Completion = C->Completion;
2088     if (!Context.getPreferredType().isNull()) {
2089       if (C->Kind == CXCursor_MacroDefinition) {
2090         Priority = getMacroUsagePriority(C->Completion->getTypedText(),
2091                                          S.getLangOptions(),
2092                                Context.getPreferredType()->isAnyPointerType());
2093       } else if (C->Type) {
2094         CanQualType Expected
2095           = S.Context.getCanonicalType(
2096                                Context.getPreferredType().getUnqualifiedType());
2097         SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
2098         if (ExpectedSTC == C->TypeClass) {
2099           // We know this type is similar; check for an exact match.
2100           llvm::StringMap<unsigned> &CachedCompletionTypes
2101             = AST.getCachedCompletionTypes();
2102           llvm::StringMap<unsigned>::iterator Pos
2103             = CachedCompletionTypes.find(QualType(Expected).getAsString());
2104           if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
2105             Priority /= CCF_ExactTypeMatch;
2106           else
2107             Priority /= CCF_SimilarTypeMatch;
2108         }
2109       }
2110     }
2111
2112     // Adjust the completion string, if required.
2113     if (C->Kind == CXCursor_MacroDefinition &&
2114         Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
2115       // Create a new code-completion string that just contains the
2116       // macro name, without its arguments.
2117       CodeCompletionBuilder Builder(getAllocator(), CCP_CodePattern,
2118                                     C->Availability);
2119       Builder.AddTypedTextChunk(C->Completion->getTypedText());
2120       CursorKind = CXCursor_NotImplemented;
2121       Priority = CCP_CodePattern;
2122       Completion = Builder.TakeString();
2123     }
2124
2125     AllResults.push_back(Result(Completion, Priority, CursorKind,
2126                                 C->Availability));
2127   }
2128
2129   // If we did not add any cached completion results, just forward the
2130   // results we were given to the next consumer.
2131   if (!AddedResult) {
2132     Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
2133     return;
2134   }
2135
2136   Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
2137                                   AllResults.size());
2138 }
2139
2140
2141
2142 void ASTUnit::CodeComplete(llvm::StringRef File, unsigned Line, unsigned Column,
2143                            RemappedFile *RemappedFiles,
2144                            unsigned NumRemappedFiles,
2145                            bool IncludeMacros,
2146                            bool IncludeCodePatterns,
2147                            CodeCompleteConsumer &Consumer,
2148                            Diagnostic &Diag, LangOptions &LangOpts,
2149                            SourceManager &SourceMgr, FileManager &FileMgr,
2150                    llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
2151              llvm::SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
2152   if (!Invocation)
2153     return;
2154
2155   SimpleTimer CompletionTimer(WantTiming);
2156   CompletionTimer.setOutput("Code completion @ " + File + ":" +
2157                             llvm::Twine(Line) + ":" + llvm::Twine(Column));
2158
2159   llvm::IntrusiveRefCntPtr<CompilerInvocation>
2160     CCInvocation(new CompilerInvocation(*Invocation));
2161
2162   FrontendOptions &FrontendOpts = CCInvocation->getFrontendOpts();
2163   PreprocessorOptions &PreprocessorOpts = CCInvocation->getPreprocessorOpts();
2164
2165   FrontendOpts.ShowMacrosInCodeCompletion
2166     = IncludeMacros && CachedCompletionResults.empty();
2167   FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
2168   FrontendOpts.ShowGlobalSymbolsInCodeCompletion
2169     = CachedCompletionResults.empty();
2170   FrontendOpts.CodeCompletionAt.FileName = File;
2171   FrontendOpts.CodeCompletionAt.Line = Line;
2172   FrontendOpts.CodeCompletionAt.Column = Column;
2173
2174   // Set the language options appropriately.
2175   LangOpts = CCInvocation->getLangOpts();
2176
2177   llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
2178
2179   // Recover resources if we crash before exiting this method.
2180   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
2181     CICleanup(Clang.get());
2182
2183   Clang->setInvocation(&*CCInvocation);
2184   OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
2185
2186   // Set up diagnostics, capturing any diagnostics produced.
2187   Clang->setDiagnostics(&Diag);
2188   ProcessWarningOptions(Diag, CCInvocation->getDiagnosticOpts());
2189   CaptureDroppedDiagnostics Capture(true,
2190                                     Clang->getDiagnostics(),
2191                                     StoredDiagnostics);
2192
2193   // Create the target instance.
2194   Clang->getTargetOpts().Features = TargetFeatures;
2195   Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
2196                                                Clang->getTargetOpts()));
2197   if (!Clang->hasTarget()) {
2198     Clang->setInvocation(0);
2199     return;
2200   }
2201
2202   // Inform the target of the language options.
2203   //
2204   // FIXME: We shouldn't need to do this, the target should be immutable once
2205   // created. This complexity should be lifted elsewhere.
2206   Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
2207
2208   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
2209          "Invocation must have exactly one source file!");
2210   assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
2211          "FIXME: AST inputs not yet supported here!");
2212   assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
2213          "IR inputs not support here!");
2214
2215
2216   // Use the source and file managers that we were given.
2217   Clang->setFileManager(&FileMgr);
2218   Clang->setSourceManager(&SourceMgr);
2219
2220   // Remap files.
2221   PreprocessorOpts.clearRemappedFiles();
2222   PreprocessorOpts.RetainRemappedFileBuffers = true;
2223   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
2224     FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
2225     if (const llvm::MemoryBuffer *
2226             memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
2227       PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, memBuf);
2228       OwnedBuffers.push_back(memBuf);
2229     } else {
2230       const char *fname = fileOrBuf.get<const char *>();
2231       PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, fname);
2232     }
2233   }
2234
2235   // Use the code completion consumer we were given, but adding any cached
2236   // code-completion results.
2237   AugmentedCodeCompleteConsumer *AugmentedConsumer
2238     = new AugmentedCodeCompleteConsumer(*this, Consumer,
2239                                         FrontendOpts.ShowMacrosInCodeCompletion,
2240                                 FrontendOpts.ShowCodePatternsInCodeCompletion,
2241                                 FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
2242   Clang->setCodeCompletionConsumer(AugmentedConsumer);
2243
2244   // If we have a precompiled preamble, try to use it. We only allow
2245   // the use of the precompiled preamble if we're if the completion
2246   // point is within the main file, after the end of the precompiled
2247   // preamble.
2248   llvm::MemoryBuffer *OverrideMainBuffer = 0;
2249   if (!PreambleFile.empty()) {
2250     using llvm::sys::FileStatus;
2251     llvm::sys::PathWithStatus CompleteFilePath(File);
2252     llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
2253     if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
2254       if (const FileStatus *MainStatus = MainPath.getFileStatus())
2255         if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID())
2256           OverrideMainBuffer
2257             = getMainBufferWithPrecompiledPreamble(*CCInvocation, false,
2258                                                    Line - 1);
2259   }
2260
2261   // If the main file has been overridden due to the use of a preamble,
2262   // make that override happen and introduce the preamble.
2263   PreprocessorOpts.DisableStatCache = true;
2264   StoredDiagnostics.insert(StoredDiagnostics.end(),
2265                            this->StoredDiagnostics.begin(),
2266              this->StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver);
2267   if (OverrideMainBuffer) {
2268     PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
2269     PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
2270     PreprocessorOpts.PrecompiledPreambleBytes.second
2271                                                     = PreambleEndsAtStartOfLine;
2272     PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
2273     PreprocessorOpts.DisablePCHValidation = true;
2274
2275     // The stored diagnostics have the old source manager. Copy them
2276     // to our output set of stored diagnostics, updating the source
2277     // manager to the one we were given.
2278     for (unsigned I = NumStoredDiagnosticsFromDriver,
2279                   N = this->StoredDiagnostics.size();
2280          I < N; ++I) {
2281       StoredDiagnostics.push_back(this->StoredDiagnostics[I]);
2282       FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SourceMgr);
2283       StoredDiagnostics[I].setLocation(Loc);
2284     }
2285
2286     OwnedBuffers.push_back(OverrideMainBuffer);
2287   } else {
2288     PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
2289     PreprocessorOpts.PrecompiledPreambleBytes.second = false;
2290   }
2291
2292   // Disable the preprocessing record
2293   PreprocessorOpts.DetailedRecord = false;
2294
2295   llvm::OwningPtr<SyntaxOnlyAction> Act;
2296   Act.reset(new SyntaxOnlyAction);
2297   if (Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
2298                            Clang->getFrontendOpts().Inputs[0].first)) {
2299     Act->Execute();
2300     Act->EndSourceFile();
2301   }
2302 }
2303
2304 CXSaveError ASTUnit::Save(llvm::StringRef File) {
2305   if (getDiagnostics().hasUnrecoverableErrorOccurred())
2306     return CXSaveError_TranslationErrors;
2307
2308   // FIXME: Can we somehow regenerate the stat cache here, or do we need to
2309   // unconditionally create a stat cache when we parse the file?
2310   std::string ErrorInfo;
2311   llvm::raw_fd_ostream Out(File.str().c_str(), ErrorInfo,
2312                            llvm::raw_fd_ostream::F_Binary);
2313   if (!ErrorInfo.empty() || Out.has_error())
2314     return CXSaveError_Unknown;
2315
2316   serialize(Out);
2317   Out.close();
2318   return Out.has_error()? CXSaveError_Unknown : CXSaveError_None;
2319 }
2320
2321 bool ASTUnit::serialize(llvm::raw_ostream &OS) {
2322   if (getDiagnostics().hasErrorOccurred())
2323     return true;
2324
2325   std::vector<unsigned char> Buffer;
2326   llvm::BitstreamWriter Stream(Buffer);
2327   ASTWriter Writer(Stream);
2328   Writer.WriteAST(getSema(), 0, std::string(), 0);
2329
2330   // Write the generated bitstream to "Out".
2331   if (!Buffer.empty())
2332     OS.write((char *)&Buffer.front(), Buffer.size());
2333
2334   return false;
2335 }