C++ Sema::WeakTopLevelDecls方法代码示例

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();
  }
}

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);

  // Initialize the template instantiation observer chain.
  // FIXME: See note on "finalize" below.
  initialize(S.TemplateInstCallbacks, S);

  ASTConsumer *Consumer = &S.getASTConsumer();

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

  llvm::CrashRecoveryContextCleanupRegistrar<const void, ResetStackCleanup>
      CleanupPrettyStack(llvm::SavePrettyStackState());
  PrettyStackTraceParserEntry CrashInfo(P);

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

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

  Parser::DeclGroupPtrTy ADecl;
  ExternalASTSource *External = S.getASTContext().getExternalSource();
  if (External)
    External->StartTranslationUnit(Consumer);

  for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl); !AtEOF;
       AtEOF = P.ParseTopLevelDecl(ADecl)) {
    // 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;
  }

  // Process any TopLevelDecls generated by #pragma weak.
  for (Decl *D : S.WeakTopLevelDecls())
    Consumer->HandleTopLevelDecl(DeclGroupRef(D));
  
  Consumer->HandleTranslationUnit(S.getASTContext());

  // Finalize the template instantiation observer chain.
  // FIXME: This (and init.) should be done in the Sema class, but because
  // Sema does not have a reliable "Finalize" function (it has a
  // destructor, but it is not guaranteed to be called ("-disable-free")).
  // So, do the initialization above and do the finalization here:
  finalize(S.TemplateInstCallbacks, S);

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