path: root/libsolidity/analysis/ConstantEvaluator.h

/*
    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 2015
 * Evaluator for types of constant expressions.
 */

#pragma once

#include <libsolidity/ast/ASTVisitor.h>

namespace langutil
{
class ErrorReporter;
}

namespace dev
{
namespace solidity
{

class TypeChecker;

/**
 * Small drop-in replacement for TypeChecker to evaluate simple expressions of integer constants.
 */
class ConstantEvaluator: private ASTConstVisitor
{
public:
    ConstantEvaluator(
        langutil::ErrorReporter& _errorReporter,
        size_t _newDepth = 0,
        std::shared_ptr<std::map<ASTNode const*, TypePointer>> _types = std::make_shared<std::map<ASTNode const*, TypePointer>>()
    ):
        m_errorReporter(_errorReporter),
        m_depth(_newDepth),
        m_types(_types)
    {
    }

    TypePointer evaluate(Expression const& _expr);

private:
    virtual void endVisit(BinaryOperation const& _operation);
    virtual void endVisit(UnaryOperation const& _operation);
    virtual void endVisit(Literal const& _literal);
    virtual void endVisit(Identifier const& _identifier);
    virtual void endVisit(TupleExpression const& _tuple);

    void setType(ASTNode const& _node, TypePointer const& _type);
    TypePointer type(ASTNode const& _node);

    langutil::ErrorReporter& m_errorReporter;
    /// Current recursion depth.
    size_t m_depth = 0;
    std::shared_ptr<std::map<ASTNode const*, TypePointer>> m_types;
};

}
}