C++ Sema::Initialize方法代码示例

  void IncrementalParser::Initialize() {
    if (hasCodeGenerator())
      getCodeGenerator()->Initialize(getCI()->getASTContext());

    CompilationOptions CO;
    CO.DeclarationExtraction = 0;
    CO.ValuePrinting = CompilationOptions::VPDisabled;
    CO.CodeGeneration = hasCodeGenerator();

    // pull in PCHs
    const std::string& PCHFileName
      = m_CI->getInvocation ().getPreprocessorOpts().ImplicitPCHInclude;
    if (!PCHFileName.empty()) {
      
      Transaction* CurT = beginTransaction(CO);
      m_CI->createPCHExternalASTSource(PCHFileName,
                                       true /*DisablePCHValidation*/,
                                       true /*AllowPCHWithCompilerErrors*/,
                                       0 /*DeserializationListener*/);
      Transaction* EndedT = endTransaction(CurT);
      commitTransaction(EndedT);
    }

    Transaction* CurT = beginTransaction(CO);
    Sema* TheSema = &m_CI->getSema();
    m_Parser.reset(new Parser(m_CI->getPreprocessor(), *TheSema,
                              false /*skipFuncBodies*/));
    m_CI->getPreprocessor().EnterMainSourceFile();
    // Initialize the parser after we have entered the main source file.
    m_Parser->Initialize();
    // Perform initialization that occurs after the parser has been initialized
    // but before it parses anything. Initializes the consumers too.
    TheSema->Initialize();

    ExternalASTSource *External = TheSema->getASTContext().getExternalSource();
    if (External)
      External->StartTranslationUnit(m_Consumer);

    Transaction* EndedT = endTransaction(CurT);
    commitTransaction(EndedT);
  }

void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
  // Collect global stats on Decls/Stmts (until we have a module streamer).
  if (PrintStats) {
    Decl::EnableStatistics();
    Stmt::EnableStatistics();
  }

  // Also turn on collection of stats inside of the Sema object.
  bool OldCollectStats = PrintStats;
  std::swap(OldCollectStats, S.CollectStats);

  ASTConsumer *Consumer = &S.getASTConsumer();

  OwningPtr<Parser> ParseOP(new Parser(S.getPreprocessor(), S,
                                       SkipFunctionBodies));
  Parser &P = *ParseOP.get();

  PrettyStackTraceParserEntry CrashInfo(P);

  // Recover resources if we crash before exiting this method.
  llvm::CrashRecoveryContextCleanupRegistrar<Parser>
    CleanupParser(ParseOP.get());

  S.getPreprocessor().EnterMainSourceFile();
  P.Initialize();
  S.Initialize();

  // C11 6.9p1 says translation units must have at least one top-level
  // declaration. C++ doesn't have this restriction. We also don't want to
  // complain if we have a precompiled header, although technically if the PCH
  // is empty we should still emit the (pedantic) diagnostic.
  Parser::DeclGroupPtrTy ADecl;
  ExternalASTSource *External = S.getASTContext().getExternalSource();
  if (External)
    External->StartTranslationUnit(Consumer);

  if (P.ParseTopLevelDecl(ADecl)) {
    if (!External && !S.getLangOpts().CPlusPlus)
      P.Diag(diag::ext_empty_translation_unit);
  } else {
    do {
      // If we got a null return and something *was* parsed, ignore it.  This
      // is due to a top-level semicolon, an action override, or a parse error
      // skipping something.
      if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
	return;
    } while (!P.ParseTopLevelDecl(ADecl));
  }

  // Process any TopLevelDecls generated by #pragma weak.
  for (SmallVector<Decl*,2>::iterator
       I = S.WeakTopLevelDecls().begin(),
       E = S.WeakTopLevelDecls().end(); I != E; ++I)
    Consumer->HandleTopLevelDecl(DeclGroupRef(*I));
  
  Consumer->HandleTranslationUnit(S.getASTContext());

  std::swap(OldCollectStats, S.CollectStats);
  if (PrintStats) {
    llvm::errs() << "\nSTATISTICS:\n";
    P.getActions().PrintStats();
    S.getASTContext().PrintStats();
    Decl::PrintStats();
    Stmt::PrintStats();
    Consumer->PrintStats();
  }
}