solidity/liblangutil/ParserBase.h
rocky ca3afea1d7 Add Steve Johnson-style parser recovery rules:
SourceUnit = Error $
    Block = '{' Error '}'
    ContractDefinition = '{' Error '}'
    Statement = Error ';'

Co-Authored-By: chriseth <chris@ethereum.org>
2019-06-17 14:47:07 +02:00

117 lines
3.9 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2016
* Solidity parser shared functionality.
*/
#pragma once
#include <liblangutil/Token.h>
#include <liblangutil/Scanner.h>
#include <memory>
#include <string>
namespace langutil
{
class ErrorReporter;
class Scanner;
class ParserBase
{
public:
/// Set @a _parserErrorRecovery to true for additional error
/// recovery. This is experimental and intended for use
/// by front-end tools that need partial AST information even
/// when errors occur.
explicit ParserBase(ErrorReporter& errorReporter, bool _parserErrorRecovery = false): m_errorReporter(errorReporter)
{
m_parserErrorRecovery = _parserErrorRecovery;
}
std::shared_ptr<CharStream> source() const { return m_scanner->charStream(); }
protected:
/// Utility class that creates an error and throws an exception if the
/// recursion depth is too deep.
class RecursionGuard
{
public:
explicit RecursionGuard(ParserBase& _parser): m_parser(_parser)
{
m_parser.increaseRecursionDepth();
}
~RecursionGuard() { m_parser.decreaseRecursionDepth(); }
private:
ParserBase& m_parser;
};
/// Start position of the current token
int position() const;
/// End position of the current token
int endPosition() const;
///@{
///@name Helper functions
/// If current token value is not @a _value, throw exception otherwise advance token
// @a if _advance is true and error recovery is in effect.
void expectToken(Token _value, bool _advance = true);
/// Like expectToken but if there is an error ignores tokens until
/// the expected token or EOS is seen. If EOS is encountered, back up to the error point,
/// and throw an exception so that a higher grammar rule has an opportunity to recover.
void expectTokenOrConsumeUntil(Token _value, std::string const& _currentNodeName, bool _advance = true);
Token currentToken() const;
Token peekNextToken() const;
std::string tokenName(Token _token);
std::string currentLiteral() const;
Token advance();
///@}
/// Increases the recursion depth and throws an exception if it is too deep.
void increaseRecursionDepth();
void decreaseRecursionDepth();
/// Creates a @ref ParserError and annotates it with the current position and the
/// given @a _description.
void parserError(std::string const& _description);
void parserError(SourceLocation const& _location, std::string const& _description);
/// Creates a @ref ParserWarning and annotates it with the current position and the
/// given @a _description.
void parserWarning(std::string const& _description);
/// Creates a @ref ParserError and annotates it with the current position and the
/// given @a _description. Throws the FatalError.
void fatalParserError(std::string const& _description);
void fatalParserError(SourceLocation const& _location, std::string const& _description);
std::shared_ptr<Scanner> m_scanner;
/// The reference to the list of errors and warning to add errors/warnings during parsing
ErrorReporter& m_errorReporter;
/// Current recursion depth during parsing.
size_t m_recursionDepth = 0;
/// True if we are in parser error recovery. Usually this means we are scanning for
/// a synchronization token like ';', or '}'. We use this to reduce cascaded error messages.
bool m_inParserRecovery = false;
bool m_parserErrorRecovery = false;
};
}