C++ ParserResult::getPtrOrNull方法代码示例

/// Parse an optional type annotation on a pattern.
///
///  pattern-type-annotation ::= (':' type)?
///
ParserResult<Pattern> Parser::
parseOptionalPatternTypeAnnotation(ParserResult<Pattern> result,
                                   bool isOptional) {

  // Parse an optional type annotation.
  if (!consumeIf(tok::colon))
    return result;

  Pattern *P;
  if (result.isNull())  // Recover by creating AnyPattern.
    P = new (Context) AnyPattern(Tok.getLoc());
  else
    P = result.get();

  ParserResult<TypeRepr> Ty = parseType();
  if (Ty.hasCodeCompletion())
    return makeParserCodeCompletionResult<Pattern>();

  TypeRepr *repr = Ty.getPtrOrNull();
  if (!repr)
    repr = new (Context) ErrorTypeRepr(PreviousLoc);

  // In an if-let, the actual type of the expression is Optional of whatever
  // was written.
  if (isOptional)
    repr = new (Context) OptionalTypeRepr(repr, Tok.getLoc());

  return makeParserResult(new (Context) TypedPattern(P, repr));
}

/// parseTypeIdentifierOrTypeComposition
/// - Identifiers and compositions both start with the same identifier
///   token, parse it and continue constructing a composition if the
///   next token is '&'
///
///   type-composition:
///     type-identifier ('&' type-identifier)*
///     'protocol' '<' type-composition-list-deprecated? '>'
///
///   type-composition-list-deprecated:
///     type-identifier (',' type-identifier)*
ParserResult<TypeRepr> Parser::parseTypeIdentifierOrTypeComposition() {
  
  // Handle deprecated case
  if (Tok.getKind() == tok::kw_protocol && startsWithLess(peekToken())) {
    SourceLoc ProtocolLoc = consumeToken(tok::kw_protocol);
    SourceLoc LAngleLoc = consumeStartingLess();
    
    // Parse the type-composition-list.
    ParserStatus Status;
    SmallVector<IdentTypeRepr *, 4> Protocols;
    bool IsEmpty = startsWithGreater(Tok);
    if (!IsEmpty) {
      do {
        // Parse the type-identifier.
        ParserResult<TypeRepr> Protocol = parseTypeIdentifier();
        Status |= Protocol;
        if (auto *ident = dyn_cast_or_null<IdentTypeRepr>(
                                                       Protocol.getPtrOrNull()))
          Protocols.push_back(ident);
      } while (consumeIf(tok::comma));
    }

    // Check for the terminating '>'.
    SourceLoc RAngleLoc = PreviousLoc;
    if (startsWithGreater(Tok)) {
      RAngleLoc = consumeStartingGreater();
    } else {
      if (Status.isSuccess()) {
        diagnose(Tok, diag::expected_rangle_protocol);
        diagnose(LAngleLoc, diag::opening_angle);
        Status.setIsParseError();
      }
      
      // Skip until we hit the '>'.
      RAngleLoc = skipUntilGreaterInTypeList(/*protocolComposition=*/true);
    }

    auto composition = ProtocolCompositionTypeRepr::create(
      Context, Protocols, ProtocolLoc, {LAngleLoc, RAngleLoc});

    if (Status.isSuccess()) {
      // Only if we have complete protocol<...> construct, diagnose deprecated.

      SmallString<32> replacement;
      if (Protocols.empty()) {
        replacement = "Any";
      } else {
        auto extractText = [&](IdentTypeRepr *Ty) -> StringRef {
          auto SourceRange = Ty->getSourceRange();
          return SourceMgr.extractText(
            Lexer::getCharSourceRangeFromSourceRange(SourceMgr, SourceRange));
        };
        auto Begin = Protocols.begin();
        replacement += extractText(*Begin);
        while (++Begin != Protocols.end()) {
          replacement += " & ";
          replacement += extractText(*Begin);
        }
      }

      // Copy trailing content after '>' to the replacement string.
      // FIXME: lexer should smartly separate '>' and trailing contents like '?'.
      StringRef TrailingContent = L->getTokenAt(RAngleLoc).getRange().str().
        substr(1);
      if (!TrailingContent.empty()) {
        if (Protocols.size() > 1) {
          replacement.insert(replacement.begin(), '(');
          replacement += ")";
        }
        replacement += TrailingContent;
      }

      // Replace 'protocol<T1, T2>' with 'T1 & T2'
      diagnose(ProtocolLoc,
        IsEmpty              ? diag::deprecated_any_composition :
        Protocols.size() > 1 ? diag::deprecated_protocol_composition :
                               diag::deprecated_protocol_composition_single)
        .highlight(composition->getSourceRange())
        .fixItReplace(composition->getSourceRange(), replacement);
    }

    return makeParserResult(Status, composition);
  }
  
  SourceLoc FirstTypeLoc = Tok.getLoc();
  
  // Parse the first type
  ParserResult<TypeRepr> FirstType = parseTypeIdentifier();
  if (!Tok.isContextualPunctuator("&"))
//.........这里部分代码省略.........

/// Parse a function definition signature.
///   func-signature:
///     func-arguments func-throws? func-signature-result?
///   func-signature-result:
///     '->' type
///
/// Note that this leaves retType as null if unspecified.
ParserStatus
Parser::parseFunctionSignature(Identifier SimpleName,
                               DeclName &FullName,
                               SmallVectorImpl<ParameterList*> &bodyParams,
                               DefaultArgumentInfo &defaultArgs,
                               SourceLoc &throwsLoc,
                               bool &rethrows,
                               TypeRepr *&retType) {
  SmallVector<Identifier, 4> NamePieces;
  NamePieces.push_back(SimpleName);
  FullName = SimpleName;
  
  ParserStatus Status;
  // We force first type of a func declaration to be a tuple for consistency.
  if (Tok.is(tok::l_paren)) {
    ParameterContextKind paramContext;
    if (SimpleName.isOperator())
      paramContext = ParameterContextKind::Operator;
    else
      paramContext = ParameterContextKind::Function;

    Status = parseFunctionArguments(NamePieces, bodyParams, paramContext,
                                    defaultArgs);
    FullName = DeclName(Context, SimpleName, 
                        llvm::makeArrayRef(NamePieces.begin() + 1,
                                           NamePieces.end()));

    if (bodyParams.empty()) {
      // If we didn't get anything, add a () pattern to avoid breaking
      // invariants.
      assert(Status.hasCodeCompletion() || Status.isError());
      bodyParams.push_back(ParameterList::createEmpty(Context));
    }
  } else {
    diagnose(Tok, diag::func_decl_without_paren);
    Status = makeParserError();

    // Recover by creating a '() -> ?' signature.
    bodyParams.push_back(ParameterList::createEmpty(Context, PreviousLoc,
                                                    PreviousLoc));
    FullName = DeclName(Context, SimpleName, bodyParams.back());
  }
  
  // Check for the 'throws' keyword.
  rethrows = false;
  if (Tok.is(tok::kw_throws)) {
    throwsLoc = consumeToken();
  } else if (Tok.is(tok::kw_rethrows)) {
    throwsLoc = consumeToken();
    rethrows = true;
  } else if (Tok.is(tok::kw_throw)) {
    throwsLoc = consumeToken();
    diagnose(throwsLoc, diag::throw_in_function_type)
      .fixItReplace(throwsLoc, "throws");
  }

  SourceLoc arrowLoc;
  // If there's a trailing arrow, parse the rest as the result type.
  if (Tok.isAny(tok::arrow, tok::colon)) {
    if (!consumeIf(tok::arrow, arrowLoc)) {
      // FixIt ':' to '->'.
      diagnose(Tok, diag::func_decl_expected_arrow)
          .fixItReplace(SourceRange(Tok.getLoc()), "->");
      arrowLoc = consumeToken(tok::colon);
    }

    ParserResult<TypeRepr> ResultType =
      parseType(diag::expected_type_function_result);
    if (ResultType.hasCodeCompletion())
      return ResultType;
    retType = ResultType.getPtrOrNull();
    if (!retType) {
      Status.setIsParseError();
      return Status;
    }
  } else {
    // Otherwise, we leave retType null.
    retType = nullptr;
  }

  // Check for 'throws' and 'rethrows' after the type and correct it.
  if (!throwsLoc.isValid()) {
    if (Tok.is(tok::kw_throws)) {
      throwsLoc = consumeToken();
    } else if (Tok.is(tok::kw_rethrows)) {
      throwsLoc = consumeToken();
      rethrows = true;
    }

    if (throwsLoc.isValid()) {
      assert(arrowLoc.isValid());
      assert(retType);
      auto diag = rethrows ? diag::rethrows_after_function_result
//.........这里部分代码省略.........