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/Tool.h"
  24 #include "clang/Frontend/CompilerInstance.h"
  25 #include "clang/Frontend/FrontendActions.h"
  26 #include "clang/Frontend/FrontendDiagnostic.h"
  27 #include "clang/Frontend/FrontendOptions.h"
  28 #include "clang/Frontend/Utils.h"
  29 #include "clang/Serialization/ASTReader.h"
  30 #include "clang/Serialization/ASTWriter.h"
  31 #include "clang/Lex/HeaderSearch.h"
  32 #include "clang/Lex/Preprocessor.h"
  33 #include "clang/Basic/TargetOptions.h"
  34 #include "clang/Basic/TargetInfo.h"
  35 #include "clang/Basic/Diagnostic.h"
  36 #include "llvm/ADT/StringSet.h"
  37 #include "llvm/Support/MemoryBuffer.h"
  38 #include "llvm/System/Host.h"
  39 #include "llvm/System/Path.h"
  40 #include "llvm/Support/raw_ostream.h"
  41 #include "llvm/Support/Timer.h"
  42 #include <cstdlib>
  43 #include <cstdio>
  44 #include <sys/stat.h>
  45 using namespace clang;
  46
  47 using llvm::TimeRecord;
  48
  49 namespace {
  50   class SimpleTimer {
  51     bool WantTiming;
  52     TimeRecord Start;
  53     std::string Output;
  54
  55   public:
  56     explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
  57       if (WantTiming)
  58         Start = TimeRecord::getCurrentTime();
  59     }
  60
  61     void setOutput(const llvm::Twine &Output) {
  62       if (WantTiming)
  63         this->Output = Output.str();
  64     }
  65
  66     ~SimpleTimer() {
  67       if (WantTiming) {
  68         TimeRecord Elapsed = TimeRecord::getCurrentTime();
  69         Elapsed -= Start;
  70         llvm::errs() << Output << ':';
  71         Elapsed.print(Elapsed, llvm::errs());
  72         llvm::errs() << '\n';
  73       }
  74     }
  75   };
  76 }
  77
  78 /// \brief After failing to build a precompiled preamble (due to
  79 /// errors in the source that occurs in the preamble), the number of
  80 /// reparses during which we'll skip even trying to precompile the
  81 /// preamble.
  82 const unsigned DefaultPreambleRebuildInterval = 5;
  83
  84 /// \brief Tracks the number of ASTUnit objects that are currently active.
  85 ///
  86 /// Used for debugging purposes only.
  87 static unsigned ActiveASTUnitObjects;
  88
  89 ASTUnit::ASTUnit(bool _MainFileIsAST)
  90   : CaptureDiagnostics(false), MainFileIsAST(_MainFileIsAST),
  91     CompleteTranslationUnit(true), WantTiming(getenv("LIBCLANG_TIMING")),
  92     NumStoredDiagnosticsFromDriver(0),
  93     ConcurrencyCheckValue(CheckUnlocked),
  94     PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
  95     ShouldCacheCodeCompletionResults(false),
  96     NumTopLevelDeclsAtLastCompletionCache(0),
  97     CacheCodeCompletionCoolDown(0),
  98     UnsafeToFree(false) {
  99   if (getenv("LIBCLANG_OBJTRACKING")) {
 100     ++ActiveASTUnitObjects;
 101     fprintf(stderr, "+++ %d translation units\n", ActiveASTUnitObjects);
 102   }
 103 }
 104
 105 ASTUnit::~ASTUnit() {
 106   ConcurrencyCheckValue = CheckLocked;
 107   CleanTemporaryFiles();
 108   if (!PreambleFile.empty())
 109     llvm::sys::Path(PreambleFile).eraseFromDisk();
 110
 111   // Free the buffers associated with remapped files. We are required to
 112   // perform this operation here because we explicitly request that the
 113   // compiler instance *not* free these buffers for each invocation of the
 114   // parser.
 115   if (Invocation.get()) {
 116     PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
 117     for (PreprocessorOptions::remapped_file_buffer_iterator
 118            FB = PPOpts.remapped_file_buffer_begin(),
 119            FBEnd = PPOpts.remapped_file_buffer_end();
 120          FB != FBEnd;
 121          ++FB)
 122       delete FB->second;
 123   }
 124
 125   delete SavedMainFileBuffer;
 126   delete PreambleBuffer;
 127
 128   ClearCachedCompletionResults();
 129
 130   if (getenv("LIBCLANG_OBJTRACKING")) {
 131     --ActiveASTUnitObjects;
 132     fprintf(stderr, "--- %d translation units\n", ActiveASTUnitObjects);
 133   }
 134 }
 135
 136 void ASTUnit::CleanTemporaryFiles() {
 137   for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
 138     TemporaryFiles[I].eraseFromDisk();
 139   TemporaryFiles.clear();
 140 }
 141
 142 /// \brief Determine the set of code-completion contexts in which this
 143 /// declaration should be shown.
 144 static unsigned getDeclShowContexts(NamedDecl *ND,
 145                                     const LangOptions &LangOpts,
 146                                     bool &IsNestedNameSpecifier) {
 147   IsNestedNameSpecifier = false;
 148
 149   if (isa<UsingShadowDecl>(ND))
 150     ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
 151   if (!ND)
 152     return 0;
 153
 154   unsigned Contexts = 0;
 155   if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
 156       isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
 157     // Types can appear in these contexts.
 158     if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
 159       Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 160                 | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 161                 | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 162                 | (1 << (CodeCompletionContext::CCC_Statement - 1))
 163                 | (1 << (CodeCompletionContext::CCC_Type - 1))
 164               | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
 165
 166     // In C++, types can appear in expressions contexts (for functional casts).
 167     if (LangOpts.CPlusPlus)
 168       Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
 169
 170     // In Objective-C, message sends can send interfaces. In Objective-C++,
 171     // all types are available due to functional casts.
 172     if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
 173       Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
 174
 175     // Deal with tag names.
 176     if (isa<EnumDecl>(ND)) {
 177       Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
 178
 179       // Part of the nested-name-specifier in C++0x.
 180       if (LangOpts.CPlusPlus0x)
 181         IsNestedNameSpecifier = true;
 182     } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
 183       if (Record->isUnion())
 184         Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
 185       else
 186         Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
 187
 188       if (LangOpts.CPlusPlus)
 189         IsNestedNameSpecifier = true;
 190     } else if (isa<ClassTemplateDecl>(ND))
 191       IsNestedNameSpecifier = true;
 192   } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
 193     // Values can appear in these contexts.
 194     Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
 195              | (1 << (CodeCompletionContext::CCC_Expression - 1))
 196              | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
 197              | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
 198   } else if (isa<ObjCProtocolDecl>(ND)) {
 199     Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
 200   } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
 201     Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
 202
 203     // Part of the nested-name-specifier.
 204     IsNestedNameSpecifier = true;
 205   }
 206
 207   return Contexts;
 208 }
 209
 210 void ASTUnit::CacheCodeCompletionResults() {
 211   if (!TheSema)
 212     return;
 213
 214   SimpleTimer Timer(WantTiming);
 215   Timer.setOutput("Cache global code completions for " + getMainFileName());
 216
 217   // Clear out the previous results.
 218   ClearCachedCompletionResults();
 219
 220   // Gather the set of global code completions.
 221   typedef CodeCompletionResult Result;
 222   llvm::SmallVector<Result, 8> Results;
 223   TheSema->GatherGlobalCodeCompletions(Results);
 224
 225   // Translate global code completions into cached completions.
 226   llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
 227
 228   for (unsigned I = 0, N = Results.size(); I != N; ++I) {
 229     switch (Results[I].Kind) {
 230     case Result::RK_Declaration: {
 231       bool IsNestedNameSpecifier = false;
 232       CachedCodeCompletionResult CachedResult;
 233       CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
 234       CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
 235                                                         Ctx->getLangOptions(),
 236                                                         IsNestedNameSpecifier);
 237       CachedResult.Priority = Results[I].Priority;
 238       CachedResult.Kind = Results[I].CursorKind;
 239       CachedResult.Availability = Results[I].Availability;
 240
 241       // Keep track of the type of this completion in an ASTContext-agnostic
 242       // way.
 243       QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
 244       if (UsageType.isNull()) {
 245         CachedResult.TypeClass = STC_Void;
 246         CachedResult.Type = 0;
 247       } else {
 248         CanQualType CanUsageType
 249           = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
 250         CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
 251
 252         // Determine whether we have already seen this type. If so, we save
 253         // ourselves the work of formatting the type string by using the
 254         // temporary, CanQualType-based hash table to find the associated value.
 255         unsigned &TypeValue = CompletionTypes[CanUsageType];
 256         if (TypeValue == 0) {
 257           TypeValue = CompletionTypes.size();
 258           CachedCompletionTypes[QualType(CanUsageType).getAsString()]
 259             = TypeValue;
 260         }
 261
 262         CachedResult.Type = TypeValue;
 263       }
 264
 265       CachedCompletionResults.push_back(CachedResult);
 266
 267       /// Handle nested-name-specifiers in C++.
 268       if (TheSema->Context.getLangOptions().CPlusPlus &&
 269           IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
 270         // The contexts in which a nested-name-specifier can appear in C++.
 271         unsigned NNSContexts
 272           = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 273           | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 274           | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 275           | (1 << (CodeCompletionContext::CCC_Statement - 1))
 276           | (1 << (CodeCompletionContext::CCC_Expression - 1))
 277           | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
 278           | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
 279           | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
 280           | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
 281           | (1 << (CodeCompletionContext::CCC_Type - 1))
 282           | (1 << (CodeCompletionContext::CCC_PotentiallyQualifiedName - 1))
 283           | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
 284
 285         if (isa<NamespaceDecl>(Results[I].Declaration) ||
 286             isa<NamespaceAliasDecl>(Results[I].Declaration))
 287           NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
 288
 289         if (unsigned RemainingContexts
 290                                 = NNSContexts & ~CachedResult.ShowInContexts) {
 291           // If there any contexts where this completion can be a
 292           // nested-name-specifier but isn't already an option, create a
 293           // nested-name-specifier completion.
 294           Results[I].StartsNestedNameSpecifier = true;
 295           CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
 296           CachedResult.ShowInContexts = RemainingContexts;
 297           CachedResult.Priority = CCP_NestedNameSpecifier;
 298           CachedResult.TypeClass = STC_Void;
 299           CachedResult.Type = 0;
 300           CachedCompletionResults.push_back(CachedResult);
 301         }
 302       }
 303       break;
 304     }
 305
 306     case Result::RK_Keyword:
 307     case Result::RK_Pattern:
 308       // Ignore keywords and patterns; we don't care, since they are so
 309       // easily regenerated.
 310       break;
 311
 312     case Result::RK_Macro: {
 313       CachedCodeCompletionResult CachedResult;
 314       CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema);
 315       CachedResult.ShowInContexts
 316         = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
 317         | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
 318         | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
 319         | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
 320         | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
 321         | (1 << (CodeCompletionContext::CCC_Statement - 1))
 322         | (1 << (CodeCompletionContext::CCC_Expression - 1))
 323         | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
 324         | (1 << (CodeCompletionContext::CCC_MacroNameUse - 1))
 325         | (1 << (CodeCompletionContext::CCC_PreprocessorExpression - 1))
 326         | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
 327
 328
 329       CachedResult.Priority = Results[I].Priority;
 330       CachedResult.Kind = Results[I].CursorKind;
 331       CachedResult.Availability = Results[I].Availability;
 332       CachedResult.TypeClass = STC_Void;
 333       CachedResult.Type = 0;
 334       CachedCompletionResults.push_back(CachedResult);
 335       break;
 336     }
 337     }
 338     Results[I].Destroy();
 339   }
 340
 341   // Make a note of the state when we performed this caching.
 342   NumTopLevelDeclsAtLastCompletionCache = top_level_size();
 343 }
 344
 345 void ASTUnit::ClearCachedCompletionResults() {
 346   for (unsigned I = 0, N = CachedCompletionResults.size(); I != N; ++I)
 347     delete CachedCompletionResults[I].Completion;
 348   CachedCompletionResults.clear();
 349   CachedCompletionTypes.clear();
 350 }
 351
 352 namespace {
 353
 354 /// \brief Gathers information from ASTReader that will be used to initialize
 355 /// a Preprocessor.
 356 class ASTInfoCollector : public ASTReaderListener {
 357   LangOptions &LangOpt;
 358   HeaderSearch &HSI;
 359   std::string &TargetTriple;
 360   std::string &Predefines;
 361   unsigned &Counter;
 362
 363   unsigned NumHeaderInfos;
 364
 365 public:
 366   ASTInfoCollector(LangOptions &LangOpt, HeaderSearch &HSI,
 367                    std::string &TargetTriple, std::string &Predefines,
 368                    unsigned &Counter)
 369     : LangOpt(LangOpt), HSI(HSI), TargetTriple(TargetTriple),
 370       Predefines(Predefines), Counter(Counter), NumHeaderInfos(0) {}
 371
 372   virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
 373     LangOpt = LangOpts;
 374     return false;
 375   }
 376
 377   virtual bool ReadTargetTriple(llvm::StringRef Triple) {
 378     TargetTriple = Triple;
 379     return false;
 380   }
 381
 382   virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
 383                                     llvm::StringRef OriginalFileName,
 384                                     std::string &SuggestedPredefines) {
 385     Predefines = Buffers[0].Data;
 386     for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
 387       Predefines += Buffers[I].Data;
 388     }
 389     return false;
 390   }
 391
 392   virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
 393     HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
 394   }
 395
 396   virtual void ReadCounter(unsigned Value) {
 397     Counter = Value;
 398   }
 399 };
 400
 401 class StoredDiagnosticClient : public DiagnosticClient {
 402   llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags;
 403
 404 public:
 405   explicit StoredDiagnosticClient(
 406                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
 407     : StoredDiags(StoredDiags) { }
 408
 409   virtual void HandleDiagnostic(Diagnostic::Level Level,
 410                                 const DiagnosticInfo &Info);
 411 };
 412
 413 /// \brief RAII object that optionally captures diagnostics, if
 414 /// there is no diagnostic client to capture them already.
 415 class CaptureDroppedDiagnostics {
 416   Diagnostic &Diags;
 417   StoredDiagnosticClient Client;
 418   DiagnosticClient *PreviousClient;
 419
 420 public:
 421   CaptureDroppedDiagnostics(bool RequestCapture, Diagnostic &Diags,
 422                           llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiags)
 423     : Diags(Diags), Client(StoredDiags), PreviousClient(0)
 424   {
 425     if (RequestCapture || Diags.getClient() == 0) {
 426       PreviousClient = Diags.takeClient();
 427       Diags.setClient(&Client);
 428     }
 429   }
 430
 431   ~CaptureDroppedDiagnostics() {
 432     if (Diags.getClient() == &Client) {
 433       Diags.takeClient();
 434       Diags.setClient(PreviousClient);
 435     }
 436   }
 437 };
 438
 439 } // anonymous namespace
 440
 441 void StoredDiagnosticClient::HandleDiagnostic(Diagnostic::Level Level,
 442                                               const DiagnosticInfo &Info) {
 443   // Default implementation (Warnings/errors count).
 444   DiagnosticClient::HandleDiagnostic(Level, Info);
 445
 446   StoredDiags.push_back(StoredDiagnostic(Level, Info));
 447 }
 448
 449 const std::string &ASTUnit::getOriginalSourceFileName() {
 450   return OriginalSourceFile;
 451 }
 452
 453 const std::string &ASTUnit::getASTFileName() {
 454   assert(isMainFileAST() && "Not an ASTUnit from an AST file!");
 455   return static_cast<ASTReader *>(Ctx->getExternalSource())->getFileName();
 456 }
 457
 458 llvm::MemoryBuffer *ASTUnit::getBufferForFile(llvm::StringRef Filename,
 459                                               std::string *ErrorStr,
 460                                               int64_t FileSize) {
 461   return FileMgr->getBufferForFile(Filename, FileSystemOpts,
 462                                    ErrorStr, FileSize);
 463 }
 464
 465 /// \brief Configure the diagnostics object for use with ASTUnit.
 466 void ASTUnit::ConfigureDiags(llvm::IntrusiveRefCntPtr<Diagnostic> &Diags,
 467                              ASTUnit &AST, bool CaptureDiagnostics) {
 468   if (!Diags.getPtr()) {
 469     // No diagnostics engine was provided, so create our own diagnostics object
 470     // with the default options.
 471     DiagnosticOptions DiagOpts;
 472     DiagnosticClient *Client = 0;
 473     if (CaptureDiagnostics)
 474       Client = new StoredDiagnosticClient(AST.StoredDiagnostics);
 475     Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0, Client);
 476   } else if (CaptureDiagnostics) {
 477     Diags->setClient(new StoredDiagnosticClient(AST.StoredDiagnostics));
 478   }
 479 }
 480
 481 ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
 482                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
 483                                   const FileSystemOptions &FileSystemOpts,
 484                                   bool OnlyLocalDecls,
 485                                   RemappedFile *RemappedFiles,
 486                                   unsigned NumRemappedFiles,
 487                                   bool CaptureDiagnostics) {
 488   llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
 489   ConfigureDiags(Diags, *AST, CaptureDiagnostics);
 490
 491   AST->OnlyLocalDecls = OnlyLocalDecls;
 492   AST->CaptureDiagnostics = CaptureDiagnostics;
 493   AST->Diagnostics = Diags;
 494   AST->FileSystemOpts = FileSystemOpts;
 495   AST->FileMgr.reset(new FileManager(FileSystemOpts));
 496   AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics(),
 497                                          AST->getFileManager(),
 498                                          AST->getFileSystemOpts()));
 499   AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager(),
 500                                          AST->getFileSystemOpts()));
 501
 502   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
 503     // Create the file entry for the file that we're mapping from.
 504     const FileEntry *FromFile
 505       = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
 506                                     RemappedFiles[I].second->getBufferSize(),
 507                                              0,
 508                                              AST->getFileSystemOpts());
 509     if (!FromFile) {
 510       AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
 511         << RemappedFiles[I].first;
 512       delete RemappedFiles[I].second;
 513       continue;
 514     }
 515
 516     // Override the contents of the "from" file with the contents of
 517     // the "to" file.
 518     AST->getSourceManager().overrideFileContents(FromFile,
 519                                                  RemappedFiles[I].second);
 520   }
 521
 522   // Gather Info for preprocessor construction later on.
 523
 524   LangOptions LangInfo;
 525   HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
 526   std::string TargetTriple;
 527   std::string Predefines;
 528   unsigned Counter;
 529
 530   llvm::OwningPtr<ASTReader> Reader;
 531
 532   Reader.reset(new ASTReader(AST->getSourceManager(), AST->getFileManager(),
 533                              AST->getFileSystemOpts(), AST->getDiagnostics()));
 534   Reader->setListener(new ASTInfoCollector(LangInfo, HeaderInfo, TargetTriple,
 535                                            Predefines, Counter));
 536
 537   switch (Reader->ReadAST(Filename, ASTReader::MainFile)) {
 538   case ASTReader::Success:
 539     break;
 540
 541   case ASTReader::Failure:
 542   case ASTReader::IgnorePCH:
 543     AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
 544     return NULL;
 545   }
 546
 547   AST->OriginalSourceFile = Reader->getOriginalSourceFile();
 548
 549   // AST file loaded successfully. Now create the preprocessor.
 550
 551   // Get information about the target being compiled for.
 552   //
 553   // FIXME: This is broken, we should store the TargetOptions in the AST file.
 554   TargetOptions TargetOpts;
 555   TargetOpts.ABI = "";
 556   TargetOpts.CXXABI = "";
 557   TargetOpts.CPU = "";
 558   TargetOpts.Features.clear();
 559   TargetOpts.Triple = TargetTriple;
 560   AST->Target.reset(TargetInfo::CreateTargetInfo(AST->getDiagnostics(),
 561                                                  TargetOpts));
 562   AST->PP.reset(new Preprocessor(AST->getDiagnostics(), LangInfo,
 563                                  *AST->Target.get(),
 564                                  AST->getSourceManager(), HeaderInfo));
 565   Preprocessor &PP = *AST->PP.get();
 566
 567   PP.setPredefines(Reader->getSuggestedPredefines());
 568   PP.setCounterValue(Counter);
 569   Reader->setPreprocessor(PP);
 570
 571   // Create and initialize the ASTContext.
 572
 573   AST->Ctx.reset(new ASTContext(LangInfo,
 574                                 AST->getSourceManager(),
 575                                 *AST->Target.get(),
 576                                 PP.getIdentifierTable(),
 577                                 PP.getSelectorTable(),
 578                                 PP.getBuiltinInfo(),
 579                                 /* size_reserve = */0));
 580   ASTContext &Context = *AST->Ctx.get();
 581
 582   Reader->InitializeContext(Context);
 583
 584   // Attach the AST reader to the AST context as an external AST
 585   // source, so that declarations will be deserialized from the
 586   // AST file as needed.
 587   ASTReader *ReaderPtr = Reader.get();
 588   llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
 589   Context.setExternalSource(Source);
 590
 591   // Create an AST consumer, even though it isn't used.
 592   AST->Consumer.reset(new ASTConsumer);
 593
 594   // Create a semantic analysis object and tell the AST reader about it.
 595   AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
 596   AST->TheSema->Initialize();
 597   ReaderPtr->InitializeSema(*AST->TheSema);
 598
 599   return AST.take();
 600 }
 601
 602 namespace {
 603
 604 class TopLevelDeclTrackerConsumer : public ASTConsumer {
 605   ASTUnit &Unit;
 606
 607 public:
 608   TopLevelDeclTrackerConsumer(ASTUnit &_Unit) : Unit(_Unit) {}
 609
 610   void HandleTopLevelDecl(DeclGroupRef D) {
 611     for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
 612       Decl *D = *it;
 613       // FIXME: Currently ObjC method declarations are incorrectly being
 614       // reported as top-level declarations, even though their DeclContext
 615       // is the containing ObjC @interface/@implementation.  This is a
 616       // fundamental problem in the parser right now.
 617       if (isa<ObjCMethodDecl>(D))
 618         continue;
 619       Unit.addTopLevelDecl(D);
 620     }
 621   }
 622
 623   // We're not interested in "interesting" decls.
 624   void HandleInterestingDecl(DeclGroupRef) {}
 625 };
 626
 627 class TopLevelDeclTrackerAction : public ASTFrontendAction {
 628 public:
 629   ASTUnit &Unit;
 630
 631   virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
 632                                          llvm::StringRef InFile) {
 633     return new TopLevelDeclTrackerConsumer(Unit);
 634   }
 635
 636 public:
 637   TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
 638
 639   virtual bool hasCodeCompletionSupport() const { return false; }
 640   virtual bool usesCompleteTranslationUnit()  {
 641     return Unit.isCompleteTranslationUnit();
 642   }
 643 };
 644
 645 class PrecompilePreambleConsumer : public PCHGenerator {
 646   ASTUnit &Unit;
 647   std::vector<Decl *> TopLevelDecls;
 648
 649 public:
 650   PrecompilePreambleConsumer(ASTUnit &Unit,
 651                              const Preprocessor &PP, bool Chaining,
 652                              const char *isysroot, llvm::raw_ostream *Out)
 653     : PCHGenerator(PP, Chaining, isysroot, Out), Unit(Unit) { }
 654
 655   virtual void HandleTopLevelDecl(DeclGroupRef D) {
 656     for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
 657       Decl *D = *it;
 658       // FIXME: Currently ObjC method declarations are incorrectly being
 659       // reported as top-level declarations, even though their DeclContext
 660       // is the containing ObjC @interface/@implementation.  This is a
 661       // fundamental problem in the parser right now.
 662       if (isa<ObjCMethodDecl>(D))
 663         continue;
 664       TopLevelDecls.push_back(D);
 665     }
 666   }
 667
 668   virtual void HandleTranslationUnit(ASTContext &Ctx) {
 669     PCHGenerator::HandleTranslationUnit(Ctx);
 670     if (!Unit.getDiagnostics().hasErrorOccurred()) {
 671       // Translate the top-level declarations we captured during
 672       // parsing into declaration IDs in the precompiled
 673       // preamble. This will allow us to deserialize those top-level
 674       // declarations when requested.
 675       for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
 676         Unit.addTopLevelDeclFromPreamble(
 677                                       getWriter().getDeclID(TopLevelDecls[I]));
 678     }
 679   }
 680 };
 681
 682 class PrecompilePreambleAction : public ASTFrontendAction {
 683   ASTUnit &Unit;
 684
 685 public:
 686   explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
 687
 688   virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
 689                                          llvm::StringRef InFile) {
 690     std::string Sysroot;
 691     llvm::raw_ostream *OS = 0;
 692     bool Chaining;
 693     if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
 694                                                        OS, Chaining))
 695       return 0;
 696
 697     const char *isysroot = CI.getFrontendOpts().RelocatablePCH ?
 698                              Sysroot.c_str() : 0;
 699     return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Chaining,
 700                                           isysroot, OS);
 701   }
 702
 703   virtual bool hasCodeCompletionSupport() const { return false; }
 704   virtual bool hasASTFileSupport() const { return false; }
 705   virtual bool usesCompleteTranslationUnit() { return false; }
 706 };
 707
 708 }
 709
 710 /// Parse the source file into a translation unit using the given compiler
 711 /// invocation, replacing the current translation unit.
 712 ///
 713 /// \returns True if a failure occurred that causes the ASTUnit not to
 714 /// contain any translation-unit information, false otherwise.
 715 bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
 716   delete SavedMainFileBuffer;
 717   SavedMainFileBuffer = 0;
 718
 719   if (!Invocation.get()) {
 720     delete OverrideMainBuffer;
 721     return true;
 722   }
 723
 724   // Create the compiler instance to use for building the AST.
 725   CompilerInstance Clang;
 726   Clang.setInvocation(Invocation.take());
 727   OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
 728
 729   // Set up diagnostics, capturing any diagnostics that would
 730   // otherwise be dropped.
 731   Clang.setDiagnostics(&getDiagnostics());
 732
 733   // Create the target instance.
 734   Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
 735                                                Clang.getTargetOpts()));
 736   if (!Clang.hasTarget()) {
 737     delete OverrideMainBuffer;
 738     return true;
 739   }
 740
 741   // Inform the target of the language options.
 742   //
 743   // FIXME: We shouldn't need to do this, the target should be immutable once
 744   // created. This complexity should be lifted elsewhere.
 745   Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
 746
 747   assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
 748          "Invocation must have exactly one source file!");
 749   assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
 750          "FIXME: AST inputs not yet supported here!");
 751   assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
 752          "IR inputs not support here!");
 753
 754   // Configure the various subsystems.
 755   // FIXME: Should we retain the previous file manager?
 756   FileMgr.reset(new FileManager(Clang.getFileSystemOpts()));
 757   FileSystemOpts = Clang.getFileSystemOpts();
 758   SourceMgr.reset(new SourceManager(getDiagnostics(), *FileMgr, FileSystemOpts));
 759   TheSema.reset();
 760   Ctx.reset();
 761   PP.reset();
 762
 763   // Clear out old caches and data.
 764   TopLevelDecls.clear();
 765   CleanTemporaryFiles();
 766   PreprocessedEntitiesByFile.clear();
 767
 768   if (!OverrideMainBuffer) {
 769     StoredDiagnostics.erase(
 770                     StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
 771                             StoredDiagnostics.end());
 772     TopLevelDeclsInPreamble.clear();
 773   }
 774
 775   // Create a file manager object to provide access to and cache the filesystem.
 776   Clang.setFileManager(&getFileManager());
 777
 778   // Create the source manager.
 779   Clang.setSourceManager(&getSourceManager());
 780
 781   // If the main file has been overridden due to the use of a preamble,
 782   // make that override happen and introduce the preamble.
 783   PreprocessorOptions &PreprocessorOpts = Clang.getPreprocessorOpts();
 784   std::string PriorImplicitPCHInclude;
 785   if (OverrideMainBuffer) {
 786     PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
 787     PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
 788     PreprocessorOpts.PrecompiledPreambleBytes.second
 789                                                     = PreambleEndsAtStartOfLine;
 790     PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
 791     PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
 792     PreprocessorOpts.DisablePCHValidation = true;
 793
 794     // The stored diagnostic has the old source manager in it; update
 795     // the locations to refer into the new source manager. Since we've
 796     // been careful to make sure that the source manager's state
 797     // before and after are identical, so that we can reuse the source
 798     // location itself.
 799     for (unsigned I = NumStoredDiagnosticsFromDriver,
 800                   N = StoredDiagnostics.size();
 801          I < N; ++I) {
 802       FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
 803                         getSourceManager());
 804       StoredDiagnostics[I].setLocation(Loc);
 805     }
 806
 807     // Keep track of the override buffer;
 808     SavedMainFileBuffer = OverrideMainBuffer;
 809   } else {
 810     PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
 811     PreprocessorOpts.PrecompiledPreambleBytes.second = false;
 812   }
 813
 814   llvm::OwningPtr<TopLevelDeclTrackerAction> Act;
 815   Act.reset(new TopLevelDeclTrackerAction(*this));
 816   if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
 817                             Clang.getFrontendOpts().Inputs[0].first))
 818     goto error;
 819
 820   Act->Execute();
 821
 822   // Steal the created target, context, and preprocessor, and take back the
 823   // source and file managers.
 824   TheSema.reset(Clang.takeSema());
 825   Consumer.reset(Clang.takeASTConsumer());
 826   Ctx.reset(Clang.takeASTContext());
 827   PP.reset(Clang.takePreprocessor());
 828   Clang.takeSourceManager();
 829   Clang.takeFileManager();
 830   Target.reset(Clang.takeTarget());
 831
 832   Act->EndSourceFile();
 833
 834   // Remove the overridden buffer we used for the preamble.
 835   if (OverrideMainBuffer) {
 836     PreprocessorOpts.eraseRemappedFile(
 837                                PreprocessorOpts.remapped_file_buffer_end() - 1);
 838     PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
 839   }
 840
 841   Invocation.reset(Clang.takeInvocation());
 842   return false;
 843
 844 error:
 845   // Remove the overridden buffer we used for the preamble.
 846   if (OverrideMainBuffer) {
 847     PreprocessorOpts.eraseRemappedFile(
 848                                PreprocessorOpts.remapped_file_buffer_end() - 1);
 849     PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
 850     delete OverrideMainBuffer;
 851     SavedMainFileBuffer = 0;
 852   }
 853
 854   StoredDiagnostics.clear();
 855   Clang.takeSourceManager();
 856   Clang.takeFileManager();
 857   Invocation.reset(Clang.takeInvocation());
 858   return true;
 859 }
 860
 861 /// \brief Simple function to retrieve a path for a preamble precompiled header.
 862 static std::string GetPreamblePCHPath() {
 863   // FIXME: This is lame; sys::Path should provide this function (in particular,
 864   // it should know how to find the temporary files dir).
 865   // FIXME: This is really lame. I copied this code from the Driver!
 866   // FIXME: This is a hack so that we can override the preamble file during
 867   // crash-recovery testing, which is the only case where the preamble files
 868   // are not necessarily cleaned up.
 869   const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
 870   if (TmpFile)
 871     return TmpFile;
 872
 873   std::string Error;
 874   const char *TmpDir = ::getenv("TMPDIR");
 875   if (!TmpDir)
 876     TmpDir = ::getenv("TEMP");
 877   if (!TmpDir)
 878     TmpDir = ::getenv("TMP");
 879 #ifdef LLVM_ON_WIN32
 880   if (!TmpDir)
 881     TmpDir = ::getenv("USERPROFILE");
 882 #endif
 883   if (!TmpDir)
 884     TmpDir = "/tmp";
 885   llvm::sys::Path P(TmpDir);
 886   P.createDirectoryOnDisk(true);
 887   P.appendComponent("preamble");
 888   P.appendSuffix("pch");
 889   if (P.createTemporaryFileOnDisk())
 890     return std::string();
 891
 892   return P.str();
 893 }
 894
 895 /// \brief Compute the preamble for the main file, providing the source buffer
 896 /// that corresponds to the main file along with a pair (bytes, start-of-line)
 897 /// that describes the preamble.
 898 std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
 899 ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
 900                          unsigned MaxLines, bool &CreatedBuffer) {
 901   FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
 902   PreprocessorOptions &PreprocessorOpts
 903     = Invocation.getPreprocessorOpts();
 904   CreatedBuffer = false;
 905
 906   // Try to determine if the main file has been remapped, either from the
 907   // command line (to another file) or directly through the compiler invocation
 908   // (to a memory buffer).
 909   llvm::MemoryBuffer *Buffer = 0;
 910   llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
 911   if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
 912     // Check whether there is a file-file remapping of the main file
 913     for (PreprocessorOptions::remapped_file_iterator
 914           M = PreprocessorOpts.remapped_file_begin(),
 915           E = PreprocessorOpts.remapped_file_end();
 916          M != E;
 917          ++M) {
 918       llvm::sys::PathWithStatus MPath(M->first);
 919       if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
 920         if (MainFileStatus->uniqueID == MStatus->uniqueID) {
 921           // We found a remapping. Try to load the resulting, remapped source.
 922           if (CreatedBuffer) {
 923             delete Buffer;
 924             CreatedBuffer = false;
 925           }
 926
 927           Buffer = getBufferForFile(M->second);
 928           if (!Buffer)
 929             return std::make_pair((llvm::MemoryBuffer*)0,
 930                                   std::make_pair(0, true));
 931           CreatedBuffer = true;
 932         }
 933       }
 934     }
 935
 936     // Check whether there is a file-buffer remapping. It supercedes the
 937     // file-file remapping.
 938     for (PreprocessorOptions::remapped_file_buffer_iterator
 939            M = PreprocessorOpts.remapped_file_buffer_begin(),
 940            E = PreprocessorOpts.remapped_file_buffer_end();
 941          M != E;
 942          ++M) {
 943       llvm::sys::PathWithStatus MPath(M->first);
 944       if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
 945         if (MainFileStatus->uniqueID == MStatus->uniqueID) {
 946           // We found a remapping.
 947           if (CreatedBuffer) {
 948             delete Buffer;
 949             CreatedBuffer = false;
 950           }
 951
 952           Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
 953         }
 954       }
 955     }
 956   }
 957
 958   // If the main source file was not remapped, load it now.
 959   if (!Buffer) {
 960     Buffer = getBufferForFile(FrontendOpts.Inputs[0].second);
 961     if (!Buffer)
 962       return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
 963
 964     CreatedBuffer = true;
 965   }
 966
 967   return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer, MaxLines));
 968 }
 969
 970 static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
 971                                                       unsigned NewSize,
 972                                                       llvm::StringRef NewName) {
 973   llvm::MemoryBuffer *Result
 974     = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
 975   memcpy(const_cast<char*>(Result->getBufferStart()),
 976          Old->getBufferStart(), Old->getBufferSize());
 977   memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
 978          ' ', NewSize - Old->getBufferSize() - 1);
 979   const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
 980
 981   return Result;
 982 }
 983
 984 /// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
 985 /// the source file.
 986 ///
 987 /// This routine will compute the preamble of the main source file. If a
 988 /// non-trivial preamble is found, it will precompile that preamble into a
 989 /// precompiled header so that the precompiled preamble can be used to reduce
 990 /// reparsing time. If a precompiled preamble has already been constructed,
 991 /// this routine will determine if it is still valid and, if so, avoid
 992 /// rebuilding the precompiled preamble.
 993 ///
 994 /// \param AllowRebuild When true (the default), this routine is
 995 /// allowed to rebuild the precompiled preamble if it is found to be
 996 /// out-of-date.
 997 ///
 998 /// \param MaxLines When non-zero, the maximum number of lines that
 999 /// can occur within the preamble.
1000 ///
1001 /// \returns If the precompiled preamble can be used, returns a newly-allocated
1002 /// buffer that should be used in place of the main file when doing so.
1003 /// Otherwise, returns a NULL pointer.
1004 llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
1005                                           CompilerInvocation PreambleInvocation,
1006                                                            bool AllowRebuild,
1007                                                            unsigned MaxLines) {
1008   FrontendOptions &FrontendOpts = PreambleInvocation.getFrontendOpts();
1009   PreprocessorOptions &PreprocessorOpts
1010     = PreambleInvocation.getPreprocessorOpts();
1011
1012   bool CreatedPreambleBuffer = false;
1013   std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
1014     = ComputePreamble(PreambleInvocation, MaxLines, CreatedPreambleBuffer);
1015
1016   // If ComputePreamble() Take ownership of the
1017   llvm::OwningPtr<llvm::MemoryBuffer> OwnedPreambleBuffer;
1018   if (CreatedPreambleBuffer)
1019     OwnedPreambleBuffer.reset(NewPreamble.first);
1020
1021   if (!NewPreamble.second.first) {
1022     // We couldn't find a preamble in the main source. Clear out the current
1023     // preamble, if we have one. It's obviously no good any more.
1024     Preamble.clear();
1025     if (!PreambleFile.empty()) {
1026       llvm::sys::Path(PreambleFile).eraseFromDisk();
1027       PreambleFile.clear();
1028     }
1029
1030     // The next time we actually see a preamble, precompile it.
1031     PreambleRebuildCounter = 1;
1032     return 0;
1033   }
1034
1035   if (!Preamble.empty()) {
1036     // We've previously computed a preamble. Check whether we have the same
1037     // preamble now that we did before, and that there's enough space in
1038     // the main-file buffer within the precompiled preamble to fit the
1039     // new main file.
1040     if (Preamble.size() == NewPreamble.second.first &&
1041         PreambleEndsAtStartOfLine == NewPreamble.second.second &&
1042         NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
1043         memcmp(&Preamble[0], NewPreamble.first->getBufferStart(),
1044                NewPreamble.second.first) == 0) {
1045       // The preamble has not changed. We may be able to re-use the precompiled
1046       // preamble.
1047
1048       // Check that none of the files used by the preamble have changed.
1049       bool AnyFileChanged = false;
1050
1051       // First, make a record of those files that have been overridden via
1052       // remapping or unsaved_files.
1053       llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
1054       for (PreprocessorOptions::remapped_file_iterator
1055                 R = PreprocessorOpts.remapped_file_begin(),
1056              REnd = PreprocessorOpts.remapped_file_end();
1057            !AnyFileChanged && R != REnd;
1058            ++R) {
1059         struct stat StatBuf;
1060         if (stat(R->second.c_str(), &StatBuf)) {
1061           // If we can't stat the file we're remapping to, assume that something
1062           // horrible happened.
1063           AnyFileChanged = true;
1064           break;
1065         }
1066
1067         OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
1068                                                    StatBuf.st_mtime);
1069       }
1070       for (PreprocessorOptions::remapped_file_buffer_iterator
1071                 R = PreprocessorOpts.remapped_file_buffer_begin(),
1072              REnd = PreprocessorOpts.remapped_file_buffer_end();
1073            !AnyFileChanged && R != REnd;
1074            ++R) {
1075         // FIXME: Should we actually compare the contents of file->buffer
1076         // remappings?
1077         OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
1078                                                    0);
1079       }
1080
1081       // Check whether anything has changed.
1082       for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
1083              F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1084            !AnyFileChanged && F != FEnd;
1085            ++F) {
1086         llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1087           = OverriddenFiles.find(F->first());
1088         if (Overridden != OverriddenFiles.end()) {
1089           // This file was remapped; check whether the newly-mapped file
1090           // matches up with the previous mapping.
1091           if (Overridden->second != F->second)
1092             AnyFileChanged = true;
1093           continue;
1094         }
1095
1096         // The file was not remapped; check whether it has changed on disk.
1097         struct stat StatBuf;
1098         if (stat(F->first(), &StatBuf)) {
1099           // If we can't stat the file, assume that something horrible happened.
1100           AnyFileChanged = true;
1101         } else if (StatBuf.st_size != F->second.first ||
1102                    StatBuf.st_mtime != F->second.second)
1103           AnyFileChanged = true;
1104       }
1105
1106       if (!AnyFileChanged) {
1107         // Okay! We can re-use the precompiled preamble.
1108
1109         // Set the state of the diagnostic object to mimic its state
1110         // after parsing the preamble.
1111         // FIXME: This won't catch any #pragma push warning changes that
1112         // have occurred in the preamble.
1113         getDiagnostics().Reset();
1114         ProcessWarningOptions(getDiagnostics(),
1115                               PreambleInvocation.getDiagnosticOpts());
1116         getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1117         if (StoredDiagnostics.size() > NumStoredDiagnosticsInPreamble)
1118           StoredDiagnostics.erase(
1119             StoredDiagnostics.begin() + NumStoredDiagnosticsInPreamble,
1120                                   StoredDiagnostics.end());
1121
1122         // Create a version of the main file buffer that is padded to
1123         // buffer size we reserved when creating the preamble.
1124         return CreatePaddedMainFileBuffer(NewPreamble.first,
1125                                           PreambleReservedSize,
1126                                           FrontendOpts.Inputs[0].second);
1127       }
1128     }
1129
1130     // If we aren't allowed to rebuild the precompiled preamble, just
1131     // return now.
1132     if (!AllowRebuild)
1133       return 0;
1134
1135     // We can't reuse the previously-computed preamble. Build a new one.
1136     Preamble.clear();
1137     llvm::sys::Path(PreambleFile).eraseFromDisk();
1138     PreambleRebuildCounter = 1;
1139   } else if (!AllowRebuild) {
1140     // We aren't allowed to rebuild the precompiled preamble; just
1141     // return now.
1142     return 0;
1143   }
1144
1145   // If the preamble rebuild counter > 1, it's because we previously
1146   // failed to build a preamble and we're not yet ready to try
1147   // again. Decrement the counter and return a failure.
1148   if (PreambleRebuildCounter > 1) {
1149     --PreambleRebuildCounter;
1150     return 0;
1151   }
1152
1153   // Create a temporary file for the precompiled preamble. In rare
1154   // circumstances, this can fail.
1155   std::string PreamblePCHPath = GetPreamblePCHPath();
1156   if (PreamblePCHPath.empty()) {
1157     // Try again next time.
1158     PreambleRebuildCounter = 1;
1159     return 0;
1160   }
1161
1162   // We did not previously compute a preamble, or it can't be reused anyway.
1163   SimpleTimer PreambleTimer(WantTiming);
1164   PreambleTimer.setOutput("Precompiling preamble");
1165
1166   // Create a new buffer that stores the preamble. The buffer also contains
1167   // extra space for the original contents of the file (which will be present
1168   // when we actually parse the file) along with more room in case the file
1169   // grows.
1170   PreambleReservedSize = NewPreamble.first->getBufferSize();
1171   if (PreambleReservedSize < 4096)
1172     PreambleReservedSize = 8191;
1173   else
1174     PreambleReservedSize *= 2;
1175
1176   // Save the preamble text for later; we'll need to compare against it for
1177   // subsequent reparses.
1178   Preamble.assign(NewPreamble.first->getBufferStart(),
1179                   NewPreamble.first->getBufferStart()
1180                                                   + NewPreamble.second.first);
1181   PreambleEndsAtStartOfLine = NewPreamble.second.second;
1182
1183   delete PreambleBuffer;
1184   PreambleBuffer
1185     = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1186                                                 FrontendOpts.Inputs[0].second);
1187   memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1188          NewPreamble.first->getBufferStart(), Preamble.size());
1189   memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1190          ' ', PreambleReservedSize - Preamble.size() - 1);
1191   const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1192
1193   // Remap the main source file to the preamble buffer.
1194   llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1195   PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1196
1197   // Tell the compiler invocation to generate a temporary precompiled header.
1198   FrontendOpts.ProgramAction = frontend::GeneratePCH;
1199   FrontendOpts.ChainedPCH = true;
1200   // FIXME: Generate the precompiled header into memory?
1201   FrontendOpts.OutputFile = PreamblePCHPath;
1202   PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1203   PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1204
1205   // Create the compiler instance to use for building the precompiled preamble.
1206   CompilerInstance Clang;
1207   Clang.setInvocation(&PreambleInvocation);
1208   OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1209
1210   // Set up diagnostics, capturing all of the diagnostics produced.
1211   Clang.setDiagnostics(&getDiagnostics());
1212
1213   // Create the target instance.
1214   Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1215                                                Clang.getTargetOpts()));
1216   if (!Clang.hasTarget()) {
1217     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1218     Preamble.clear();
1219     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1220     PreprocessorOpts.eraseRemappedFile(
1221                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1222     return 0;
1223   }
1224
1225   // Inform the target of the language options.
1226   //
1227   // FIXME: We shouldn't need to do this, the target should be immutable once
1228   // created. This complexity should be lifted elsewhere.
1229   Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1230
1231   assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1232          "Invocation must have exactly one source file!");
1233   assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1234          "FIXME: AST inputs not yet supported here!");
1235   assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1236          "IR inputs not support here!");
1237
1238   // Clear out old caches and data.
1239   getDiagnostics().Reset();
1240   ProcessWarningOptions(getDiagnostics(), Clang.getDiagnosticOpts());
1241   StoredDiagnostics.erase(
1242                     StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
1243                           StoredDiagnostics.end());
1244   TopLevelDecls.clear();
1245   TopLevelDeclsInPreamble.clear();
1246
1247   // Create a file manager object to provide access to and cache the filesystem.
1248   Clang.setFileManager(new FileManager(Clang.getFileSystemOpts()));
1249
1250   // Create the source manager.
1251   Clang.setSourceManager(new SourceManager(getDiagnostics(),
1252                                            Clang.getFileManager(),
1253                                            Clang.getFileSystemOpts()));
1254
1255   llvm::OwningPtr<PrecompilePreambleAction> Act;
1256   Act.reset(new PrecompilePreambleAction(*this));
1257   if (!Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1258                             Clang.getFrontendOpts().Inputs[0].first)) {
1259     Clang.takeInvocation();
1260     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1261     Preamble.clear();
1262     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1263     PreprocessorOpts.eraseRemappedFile(
1264                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1265     return 0;
1266   }
1267
1268   Act->Execute();
1269   Act->EndSourceFile();
1270   Clang.takeInvocation();
1271
1272   if (Diagnostics->hasErrorOccurred()) {
1273     // There were errors parsing the preamble, so no precompiled header was
1274     // generated. Forget that we even tried.
1275     // FIXME: Should we leave a note for ourselves to try again?
1276     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1277     Preamble.clear();
1278     TopLevelDeclsInPreamble.clear();
1279     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1280     PreprocessorOpts.eraseRemappedFile(
1281                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1282     return 0;
1283   }
1284
1285   // Keep track of the preamble we precompiled.
1286   PreambleFile = FrontendOpts.OutputFile;
1287   NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1288   NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1289
1290   // Keep track of all of the files that the source manager knows about,
1291   // so we can verify whether they have changed or not.
1292   FilesInPreamble.clear();
1293   SourceManager &SourceMgr = Clang.getSourceManager();
1294   const llvm::MemoryBuffer *MainFileBuffer
1295     = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1296   for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1297                                      FEnd = SourceMgr.fileinfo_end();
1298        F != FEnd;
1299        ++F) {
1300     const FileEntry *File = F->second->Entry;
1301     if (!File || F->second->getRawBuffer() == MainFileBuffer)
1302       continue;
1303
1304     FilesInPreamble[File->getName()]
1305       = std::make_pair(F->second->getSize(), File->getModificationTime());
1306   }
1307
1308   PreambleRebuildCounter = 1;
1309   PreprocessorOpts.eraseRemappedFile(
1310                                PreprocessorOpts.remapped_file_buffer_end() - 1);
1311   return CreatePaddedMainFileBuffer(NewPreamble.first,
1312                                     PreambleReservedSize,
1313                                     FrontendOpts.Inputs[0].second);
1314 }
1315
1316 void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1317   std::vector<Decl *> Resolved;
1318   Resolved.reserve(TopLevelDeclsInPreamble.size());
1319   ExternalASTSource &Source = *getASTContext().getExternalSource();
1320   for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1321     // Resolve the declaration ID to an actual declaration, possibly
1322     // deserializing the declaration in the process.
1323     Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1324     if (D)
1325       Resolved.push_back(D);
1326   }
1327   TopLevelDeclsInPreamble.clear();
1328   TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1329 }
1330
1331 unsigned ASTUnit::getMaxPCHLevel() const {
1332   if (!getOnlyLocalDecls())
1333     return Decl::MaxPCHLevel;
1334
1335   return 0;
1336 }
1337
1338 llvm::StringRef ASTUnit::getMainFileName() const {
1339   return Invocation->getFrontendOpts().Inputs[0].second;
1340 }
1341
1342 bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
1343   if (!Invocation)
1344     return true;
1345
1346   // We'll manage file buffers ourselves.
1347   Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1348   Invocation->getFrontendOpts().DisableFree = false;
1349
1350   llvm::MemoryBuffer *OverrideMainBuffer = 0;
1351   if (PrecompilePreamble) {
1352     PreambleRebuildCounter = 2;
1353     OverrideMainBuffer
1354       = getMainBufferWithPrecompiledPreamble(*Invocation);
1355   }
1356
1357   SimpleTimer ParsingTimer(WantTiming);
1358   ParsingTimer.setOutput("Parsing " + getMainFileName());
1359
1360   return Parse(OverrideMainBuffer);
1361 }
1362
1363 ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1364                                    llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1365                                              bool OnlyLocalDecls,
1366                                              bool CaptureDiagnostics,
1367                                              bool PrecompilePreamble,
1368                                              bool CompleteTranslationUnit,
1369                                              bool CacheCodeCompletionResults) {
1370   // Create the AST unit.
1371   llvm::OwningPtr<ASTUnit> AST;
1372   AST.reset(new ASTUnit(false));
1373   ConfigureDiags(Diags, *AST, CaptureDiagnostics);
1374   AST->Diagnostics = Diags;
1375   AST->OnlyLocalDecls = OnlyLocalDecls;
1376   AST->CaptureDiagnostics = CaptureDiagnostics;
1377   AST->CompleteTranslationUnit = CompleteTranslationUnit;
1378   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1379   AST->CacheCodeCompletionCoolDown = 1;
1380   AST->Invocation.reset(CI);
1381
1382   return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
1383 }
1384
1385 ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1386                                       const char **ArgEnd,
1387                                     llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
1388                                       llvm::StringRef ResourceFilesPath,
1389                                       bool OnlyLocalDecls,
1390                                       bool CaptureDiagnostics,
1391                                       RemappedFile *RemappedFiles,
1392                                       unsigned NumRemappedFiles,
1393                                       bool PrecompilePreamble,
1394                                       bool CompleteTranslationUnit,
1395                                       bool CacheCodeCompletionResults,
1396                                       bool CXXPrecompilePreamble,
1397                                       bool CXXChainedPCH) {
1398   if (!Diags.getPtr()) {
1399     // No diagnostics engine was provided, so create our own diagnostics object
1400     // with the default options.
1401     DiagnosticOptions DiagOpts;
1402     Diags = CompilerInstance::createDiagnostics(DiagOpts, 0, 0);
1403   }
1404
1405   llvm::SmallVector<const char *, 16> Args;
1406   Args.push_back("<clang>"); // FIXME: Remove dummy argument.
1407   Args.insert(Args.end(), ArgBegin, ArgEnd);
1408
1409   // FIXME: Find a cleaner way to force the driver into restricted modes. We
1410   // also want to force it to use clang.
1411   Args.push_back("-fsyntax-only");
1412
1413   llvm::SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
1414
1415   llvm::OwningPtr<CompilerInvocation> CI;
1416
1417   {
1418     CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags,
1419                                       StoredDiagnostics);
1420
1421     // FIXME: We shouldn't have to pass in the path info.
1422     driver::Driver TheDriver("clang", llvm::sys::getHostTriple(),
1423                              "a.out", false, false, *Diags);
1424
1425     // Don't check that inputs exist, they have been remapped.
1426     TheDriver.setCheckInputsExist(false);
1427
1428     llvm::OwningPtr<driver::Compilation> C(
1429       TheDriver.BuildCompilation(Args.size(), Args.data()));
1430
1431     // We expect to get back exactly one command job, if we didn't something
1432     // failed.
1433     const driver::JobList &Jobs = C->getJobs();
1434     if (Jobs.size() != 1 || !isa<driver::Command>(Jobs.begin())) {
1435       llvm::SmallString<256> Msg;
1436       llvm::raw_svector_ostream OS(Msg);
1437       C->PrintJob(OS, C->getJobs(), "; ", true);
1438       Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
1439       return 0;
1440     }
1441
1442     const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
1443     if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
1444       Diags->Report(diag::err_fe_expected_clang_command);
1445       return 0;
1446     }
1447
1448     const driver::ArgStringList &CCArgs = Cmd->getArguments();
1449     CI.reset(new CompilerInvocation);
1450     CompilerInvocation::CreateFromArgs(*CI,
1451                                      const_cast<const char **>(CCArgs.data()),
1452                                      const_cast<const char **>(CCArgs.data()) +
1453                                        CCArgs.size(),
1454                                        *Diags);
1455   }
1456
1457   // Override any files that need remapping
1458   for (unsigned I = 0; I != NumRemappedFiles; ++I)
1459     CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1460                                               RemappedFiles[I].second);
1461
1462   // Override the resources path.
1463   CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1464
1465   // Check whether we should precompile the preamble and/or use chained PCH.
1466   // FIXME: This is a temporary hack while we debug C++ chained PCH.
1467   if (CI->getLangOpts().CPlusPlus) {
1468     PrecompilePreamble = PrecompilePreamble && CXXPrecompilePreamble;
1469
1470     if (PrecompilePreamble && !CXXChainedPCH &&
1471         !CI->getPreprocessorOpts().ImplicitPCHInclude.empty())
1472       PrecompilePreamble = false;
1473   }
1474
1475   // Create the AST unit.
1476   llvm::OwningPtr<ASTUnit> AST;
1477   AST.reset(new ASTUnit(false));
1478   ConfigureDiags(Diags, *AST, CaptureDiagnostics);
1479   AST->Diagnostics = Diags;
1480   AST->OnlyLocalDecls = OnlyLocalDecls;
1481   AST->CaptureDiagnostics = CaptureDiagnostics;
1482   AST->CompleteTranslationUnit = CompleteTranslationUnit;
1483   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1484   AST->CacheCodeCompletionCoolDown = 1;
1485   AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
1486   AST->NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
1487   AST->StoredDiagnostics.swap(StoredDiagnostics);
1488   AST->Invocation.reset(CI.take());
1489   return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
1490 }
1491
1492 bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1493   if (!Invocation.get())
1494     return true;
1495
1496   SimpleTimer ParsingTimer(WantTiming);
1497   ParsingTimer.setOutput("Reparsing " + getMainFileName());
1498
1499   // Remap files.
1500   PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1501   for (PreprocessorOptions::remapped_file_buffer_iterator
1502          R = PPOpts.remapped_file_buffer_begin(),
1503          REnd = PPOpts.remapped_file_buffer_end();
1504        R != REnd;
1505        ++R) {
1506     delete R->second;
1507   }
1508   Invocation->getPreprocessorOpts().clearRemappedFiles();
1509   for (unsigned I = 0; I != NumRemappedFiles; ++I)
1510     Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1511                                                       RemappedFiles[I].second);
1512
1513   // If we have a preamble file lying around, or if we might try to
1514   // build a precompiled preamble, do so now.
1515   llvm::MemoryBuffer *OverrideMainBuffer = 0;
1516   if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1517     OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
1518
1519   // Clear out the diagnostics state.
1520   if (!OverrideMainBuffer) {
1521     getDiagnostics().Reset();
1522     ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1523   }
1524
1525   // Parse the sources
1526   bool Result = Parse(OverrideMainBuffer);
1527
1528   if (ShouldCacheCodeCompletionResults) {
1529     if (CacheCodeCompletionCoolDown > 0)
1530       --CacheCodeCompletionCoolDown;
1531     else if (top_level_size() != NumTopLevelDeclsAtLastCompletionCache)
1532       CacheCodeCompletionResults();
1533   }
1534
1535   return Result;
1536 }
1537
1538 //----------------------------------------------------------------------------//
1539 // Code completion
1540 //----------------------------------------------------------------------------//
1541
1542 namespace {
1543   /// \brief Code completion consumer that combines the cached code-completion
1544   /// results from an ASTUnit with the code-completion results provided to it,
1545   /// then passes the result on to
1546   class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
1547     unsigned NormalContexts;
1548     ASTUnit &AST;
1549     CodeCompleteConsumer &Next;
1550
1551   public:
1552     AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
1553                                   bool IncludeMacros, bool IncludeCodePatterns,
1554                                   bool IncludeGlobals)
1555       : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
1556                              Next.isOutputBinary()), AST(AST), Next(Next)
1557     {
1558       // Compute the set of contexts in which we will look when we don't have
1559       // any information about the specific context.
1560       NormalContexts
1561         = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
1562         | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
1563         | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
1564         | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
1565         | (1 << (CodeCompletionContext::CCC_Statement - 1))
1566         | (1 << (CodeCompletionContext::CCC_Expression - 1))
1567         | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
1568         | (1 << (CodeCompletionContext::CCC_MemberAccess - 1))
1569         | (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1))
1570         | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
1571         | (1 << (CodeCompletionContext::CCC_Recovery - 1));
1572
1573       if (AST.getASTContext().getLangOptions().CPlusPlus)
1574         NormalContexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1))
1575                     | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
1576                     | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
1577     }
1578
1579     virtual void ProcessCodeCompleteResults(Sema &S,
1580                                             CodeCompletionContext Context,
1581                                             CodeCompletionResult *Results,
1582                                             unsigned NumResults);
1583
1584     virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
1585                                            OverloadCandidate *Candidates,
1586                                            unsigned NumCandidates) {
1587       Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
1588     }
1589   };
1590 }
1591
1592 /// \brief Helper function that computes which global names are hidden by the
1593 /// local code-completion results.
1594 static void CalculateHiddenNames(const CodeCompletionContext &Context,
1595                                  CodeCompletionResult *Results,
1596                                  unsigned NumResults,
1597                                  ASTContext &Ctx,
1598                           llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
1599   bool OnlyTagNames = false;
1600   switch (Context.getKind()) {
1601   case CodeCompletionContext::CCC_Recovery:
1602   case CodeCompletionContext::CCC_TopLevel:
1603   case CodeCompletionContext::CCC_ObjCInterface:
1604   case CodeCompletionContext::CCC_ObjCImplementation:
1605   case CodeCompletionContext::CCC_ObjCIvarList:
1606   case CodeCompletionContext::CCC_ClassStructUnion:
1607   case CodeCompletionContext::CCC_Statement:
1608   case CodeCompletionContext::CCC_Expression:
1609   case CodeCompletionContext::CCC_ObjCMessageReceiver:
1610   case CodeCompletionContext::CCC_MemberAccess:
1611   case CodeCompletionContext::CCC_Namespace:
1612   case CodeCompletionContext::CCC_Type:
1613   case CodeCompletionContext::CCC_Name:
1614   case CodeCompletionContext::CCC_PotentiallyQualifiedName:
1615   case CodeCompletionContext::CCC_ParenthesizedExpression:
1616     break;
1617
1618   case CodeCompletionContext::CCC_EnumTag:
1619   case CodeCompletionContext::CCC_UnionTag:
1620   case CodeCompletionContext::CCC_ClassOrStructTag:
1621     OnlyTagNames = true;
1622     break;
1623
1624   case CodeCompletionContext::CCC_ObjCProtocolName:
1625   case CodeCompletionContext::CCC_MacroName:
1626   case CodeCompletionContext::CCC_MacroNameUse:
1627   case CodeCompletionContext::CCC_PreprocessorExpression:
1628   case CodeCompletionContext::CCC_PreprocessorDirective:
1629   case CodeCompletionContext::CCC_NaturalLanguage:
1630   case CodeCompletionContext::CCC_SelectorName:
1631   case CodeCompletionContext::CCC_TypeQualifiers:
1632   case CodeCompletionContext::CCC_Other:
1633     // We're looking for nothing, or we're looking for names that cannot
1634     // be hidden.
1635     return;
1636   }
1637
1638   typedef CodeCompletionResult Result;
1639   for (unsigned I = 0; I != NumResults; ++I) {
1640     if (Results[I].Kind != Result::RK_Declaration)
1641       continue;
1642
1643     unsigned IDNS
1644       = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
1645
1646     bool Hiding = false;
1647     if (OnlyTagNames)
1648       Hiding = (IDNS & Decl::IDNS_Tag);
1649     else {
1650       unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
1651                              Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
1652                              Decl::IDNS_NonMemberOperator);
1653       if (Ctx.getLangOptions().CPlusPlus)
1654         HiddenIDNS |= Decl::IDNS_Tag;
1655       Hiding = (IDNS & HiddenIDNS);
1656     }
1657
1658     if (!Hiding)
1659       continue;
1660
1661     DeclarationName Name = Results[I].Declaration->getDeclName();
1662     if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
1663       HiddenNames.insert(Identifier->getName());
1664     else
1665       HiddenNames.insert(Name.getAsString());
1666   }
1667 }
1668
1669
1670 void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
1671                                             CodeCompletionContext Context,
1672                                             CodeCompletionResult *Results,
1673                                             unsigned NumResults) {
1674   // Merge the results we were given with the results we cached.
1675   bool AddedResult = false;
1676   unsigned InContexts
1677     = (Context.getKind() == CodeCompletionContext::CCC_Recovery? NormalContexts
1678                                             : (1 << (Context.getKind() - 1)));
1679
1680   // Contains the set of names that are hidden by "local" completion results.
1681   llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
1682   llvm::SmallVector<CodeCompletionString *, 4> StringsToDestroy;
1683   typedef CodeCompletionResult Result;
1684   llvm::SmallVector<Result, 8> AllResults;
1685   for (ASTUnit::cached_completion_iterator
1686             C = AST.cached_completion_begin(),
1687          CEnd = AST.cached_completion_end();
1688        C != CEnd; ++C) {
1689     // If the context we are in matches any of the contexts we are
1690     // interested in, we'll add this result.
1691     if ((C->ShowInContexts & InContexts) == 0)
1692       continue;
1693
1694     // If we haven't added any results previously, do so now.
1695     if (!AddedResult) {
1696       CalculateHiddenNames(Context, Results, NumResults, S.Context,
1697                            HiddenNames);
1698       AllResults.insert(AllResults.end(), Results, Results + NumResults);
1699       AddedResult = true;
1700     }
1701
1702     // Determine whether this global completion result is hidden by a local
1703     // completion result. If so, skip it.
1704     if (C->Kind != CXCursor_MacroDefinition &&
1705         HiddenNames.count(C->Completion->getTypedText()))
1706       continue;
1707
1708     // Adjust priority based on similar type classes.
1709     unsigned Priority = C->Priority;
1710     CXCursorKind CursorKind = C->Kind;
1711     CodeCompletionString *Completion = C->Completion;
1712     if (!Context.getPreferredType().isNull()) {
1713       if (C->Kind == CXCursor_MacroDefinition) {
1714         Priority = getMacroUsagePriority(C->Completion->getTypedText(),
1715                                          S.getLangOptions(),
1716                                Context.getPreferredType()->isAnyPointerType());
1717       } else if (C->Type) {
1718         CanQualType Expected
1719           = S.Context.getCanonicalType(
1720                                Context.getPreferredType().getUnqualifiedType());
1721         SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
1722         if (ExpectedSTC == C->TypeClass) {
1723           // We know this type is similar; check for an exact match.
1724           llvm::StringMap<unsigned> &CachedCompletionTypes
1725             = AST.getCachedCompletionTypes();
1726           llvm::StringMap<unsigned>::iterator Pos
1727             = CachedCompletionTypes.find(QualType(Expected).getAsString());
1728           if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
1729             Priority /= CCF_ExactTypeMatch;
1730           else
1731             Priority /= CCF_SimilarTypeMatch;
1732         }
1733       }
1734     }
1735
1736     // Adjust the completion string, if required.
1737     if (C->Kind == CXCursor_MacroDefinition &&
1738         Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
1739       // Create a new code-completion string that just contains the
1740       // macro name, without its arguments.
1741       Completion = new CodeCompletionString;
1742       Completion->AddTypedTextChunk(C->Completion->getTypedText());
1743       StringsToDestroy.push_back(Completion);
1744       CursorKind = CXCursor_NotImplemented;
1745       Priority = CCP_CodePattern;
1746     }
1747
1748     AllResults.push_back(Result(Completion, Priority, CursorKind,
1749                                 C->Availability));
1750   }
1751
1752   // If we did not add any cached completion results, just forward the
1753   // results we were given to the next consumer.
1754   if (!AddedResult) {
1755     Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
1756     return;
1757   }
1758
1759   Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
1760                                   AllResults.size());
1761
1762   for (unsigned I = 0, N = StringsToDestroy.size(); I != N; ++I)
1763     delete StringsToDestroy[I];
1764 }
1765
1766
1767
1768 void ASTUnit::CodeComplete(llvm::StringRef File, unsigned Line, unsigned Column,
1769                            RemappedFile *RemappedFiles,
1770                            unsigned NumRemappedFiles,
1771                            bool IncludeMacros,
1772                            bool IncludeCodePatterns,
1773                            CodeCompleteConsumer &Consumer,
1774                            Diagnostic &Diag, LangOptions &LangOpts,
1775                            SourceManager &SourceMgr, FileManager &FileMgr,
1776                    llvm::SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
1777              llvm::SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
1778   if (!Invocation.get())
1779     return;
1780
1781   SimpleTimer CompletionTimer(WantTiming);
1782   CompletionTimer.setOutput("Code completion @ " + File + ":" +
1783                             llvm::Twine(Line) + ":" + llvm::Twine(Column));
1784
1785   CompilerInvocation CCInvocation(*Invocation);
1786   FrontendOptions &FrontendOpts = CCInvocation.getFrontendOpts();
1787   PreprocessorOptions &PreprocessorOpts = CCInvocation.getPreprocessorOpts();
1788
1789   FrontendOpts.ShowMacrosInCodeCompletion
1790     = IncludeMacros && CachedCompletionResults.empty();
1791   FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
1792   FrontendOpts.ShowGlobalSymbolsInCodeCompletion
1793     = CachedCompletionResults.empty();
1794   FrontendOpts.CodeCompletionAt.FileName = File;
1795   FrontendOpts.CodeCompletionAt.Line = Line;
1796   FrontendOpts.CodeCompletionAt.Column = Column;
1797
1798   // Set the language options appropriately.
1799   LangOpts = CCInvocation.getLangOpts();
1800
1801   CompilerInstance Clang;
1802   Clang.setInvocation(&CCInvocation);
1803   OriginalSourceFile = Clang.getFrontendOpts().Inputs[0].second;
1804
1805   // Set up diagnostics, capturing any diagnostics produced.
1806   Clang.setDiagnostics(&Diag);
1807   ProcessWarningOptions(Diag, CCInvocation.getDiagnosticOpts());
1808   CaptureDroppedDiagnostics Capture(true,
1809                                     Clang.getDiagnostics(),
1810                                     StoredDiagnostics);
1811
1812   // Create the target instance.
1813   Clang.setTarget(TargetInfo::CreateTargetInfo(Clang.getDiagnostics(),
1814                                                Clang.getTargetOpts()));
1815   if (!Clang.hasTarget()) {
1816     Clang.takeInvocation();
1817     return;
1818   }
1819
1820   // Inform the target of the language options.
1821   //
1822   // FIXME: We shouldn't need to do this, the target should be immutable once
1823   // created. This complexity should be lifted elsewhere.
1824   Clang.getTarget().setForcedLangOptions(Clang.getLangOpts());
1825
1826   assert(Clang.getFrontendOpts().Inputs.size() == 1 &&
1827          "Invocation must have exactly one source file!");
1828   assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
1829          "FIXME: AST inputs not yet supported here!");
1830   assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1831          "IR inputs not support here!");
1832
1833
1834   // Use the source and file managers that we were given.
1835   Clang.setFileManager(&FileMgr);
1836   Clang.setSourceManager(&SourceMgr);
1837
1838   // Remap files.
1839   PreprocessorOpts.clearRemappedFiles();
1840   PreprocessorOpts.RetainRemappedFileBuffers = true;
1841   for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1842     PreprocessorOpts.addRemappedFile(RemappedFiles[I].first,
1843                                      RemappedFiles[I].second);
1844     OwnedBuffers.push_back(RemappedFiles[I].second);
1845   }
1846
1847   // Use the code completion consumer we were given, but adding any cached
1848   // code-completion results.
1849   AugmentedCodeCompleteConsumer
1850   AugmentedConsumer(*this, Consumer, FrontendOpts.ShowMacrosInCodeCompletion,
1851                     FrontendOpts.ShowCodePatternsInCodeCompletion,
1852                     FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
1853   Clang.setCodeCompletionConsumer(&AugmentedConsumer);
1854
1855   // If we have a precompiled preamble, try to use it. We only allow
1856   // the use of the precompiled preamble if we're if the completion
1857   // point is within the main file, after the end of the precompiled
1858   // preamble.
1859   llvm::MemoryBuffer *OverrideMainBuffer = 0;
1860   if (!PreambleFile.empty()) {
1861     using llvm::sys::FileStatus;
1862     llvm::sys::PathWithStatus CompleteFilePath(File);
1863     llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
1864     if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
1865       if (const FileStatus *MainStatus = MainPath.getFileStatus())
1866         if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID())
1867           OverrideMainBuffer
1868             = getMainBufferWithPrecompiledPreamble(CCInvocation, false,
1869                                                    Line - 1);
1870   }
1871
1872   // If the main file has been overridden due to the use of a preamble,
1873   // make that override happen and introduce the preamble.
1874   StoredDiagnostics.insert(StoredDiagnostics.end(),
1875                            this->StoredDiagnostics.begin(),
1876              this->StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver);
1877   if (OverrideMainBuffer) {
1878     PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
1879     PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
1880     PreprocessorOpts.PrecompiledPreambleBytes.second
1881                                                     = PreambleEndsAtStartOfLine;
1882     PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
1883     PreprocessorOpts.DisablePCHValidation = true;
1884
1885     // The stored diagnostics have the old source manager. Copy them
1886     // to our output set of stored diagnostics, updating the source
1887     // manager to the one we were given.
1888     for (unsigned I = NumStoredDiagnosticsFromDriver,
1889                   N = this->StoredDiagnostics.size();
1890          I < N; ++I) {
1891       StoredDiagnostics.push_back(this->StoredDiagnostics[I]);
1892       FullSourceLoc Loc(StoredDiagnostics[I].getLocation(), SourceMgr);
1893       StoredDiagnostics[I].setLocation(Loc);
1894     }
1895
1896     OwnedBuffers.push_back(OverrideMainBuffer);
1897   } else {
1898     PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1899     PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1900   }
1901
1902   llvm::OwningPtr<SyntaxOnlyAction> Act;
1903   Act.reset(new SyntaxOnlyAction);
1904   if (Act->BeginSourceFile(Clang, Clang.getFrontendOpts().Inputs[0].second,
1905                            Clang.getFrontendOpts().Inputs[0].first)) {
1906     Act->Execute();
1907     Act->EndSourceFile();
1908   }
1909
1910   // Steal back our resources.
1911   Clang.takeFileManager();
1912   Clang.takeSourceManager();
1913   Clang.takeInvocation();
1914   Clang.takeCodeCompletionConsumer();
1915 }
1916
1917 bool ASTUnit::Save(llvm::StringRef File) {
1918   if (getDiagnostics().hasErrorOccurred())
1919     return true;
1920
1921   // FIXME: Can we somehow regenerate the stat cache here, or do we need to
1922   // unconditionally create a stat cache when we parse the file?
1923   std::string ErrorInfo;
1924   llvm::raw_fd_ostream Out(File.str().c_str(), ErrorInfo,
1925                            llvm::raw_fd_ostream::F_Binary);
1926   if (!ErrorInfo.empty() || Out.has_error())
1927     return true;
1928
1929   std::vector<unsigned char> Buffer;
1930   llvm::BitstreamWriter Stream(Buffer);
1931   ASTWriter Writer(Stream);
1932   Writer.WriteAST(getSema(), 0, 0);
1933
1934   // Write the generated bitstream to "Out".
1935   if (!Buffer.empty())
1936     Out.write((char *)&Buffer.front(), Buffer.size());
1937   Out.close();
1938   return Out.has_error();
1939 }