path: root/Types.h

/*
    This file is part of cpp-ethereum.

    cpp-ethereum 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.

    cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * @author Christian <c@ethdev.com>
 * @date 2014
 * Solidity data types
 */

#pragma once

#include <memory>
#include <string>
#include <boost/noncopyable.hpp>
#include <libdevcore/Common.h>
#include <libsolidity/Exceptions.h>
#include <libsolidity/ASTForward.h>
#include <libsolidity/Token.h>

namespace dev
{
namespace solidity
{

// @todo realMxN, string<N>, mapping

/**
 * Abstract base class that forms the root of the type hierarchy.
 */
class Type: private boost::noncopyable
{
public:
    enum class Category
    {
        INTEGER, BOOL, REAL, STRING, CONTRACT, STRUCT, FUNCTION, MAPPING, VOID, TYPE
    };

    ///@{
    ///@name Factory functions
    /// Factory functions that convert an AST @ref TypeName to a Type.
    static std::shared_ptr<Type> fromElementaryTypeName(Token::Value _typeToken);
    static std::shared_ptr<Type> fromUserDefinedTypeName(UserDefinedTypeName const& _typeName);
    static std::shared_ptr<Type> fromMapping(Mapping const& _typeName);
    /// @}

    /// Auto-detect the proper type for a literal. @returns an empty pointer if the literal does
    /// not fit any type.
    static std::shared_ptr<Type> forLiteral(Literal const& _literal);

    virtual Category getCategory() const = 0;
    virtual bool isImplicitlyConvertibleTo(Type const& _other) const { return *this == _other; }
    virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const
    {
        return isImplicitlyConvertibleTo(_convertTo);
    }
    virtual bool acceptsBinaryOperator(Token::Value) const { return false; }
    virtual bool acceptsUnaryOperator(Token::Value) const { return false; }

    virtual bool operator==(Type const& _other) const { return getCategory() == _other.getCategory(); }
    virtual bool operator!=(Type const& _other) const { return !this->operator ==(_other); }

    /// @returns number of bytes used by this type when encoded for CALL, or 0 if the encoding
    /// is not a simple big-endian encoding or the type cannot be stored on the stack.
    virtual unsigned getCalldataEncodedSize() const { return 0; }

    virtual std::string toString() const = 0;
    virtual u256 literalValue(Literal const&) const
    {
        BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Literal value requested "
                                                                          "for type without literals."));
    }
};

/**
 * Any kind of integer type including hash and address.
 */
class IntegerType: public Type
{
public:
    enum class Modifier
    {
        UNSIGNED, SIGNED, HASH, ADDRESS
    };
    virtual Category getCategory() const override { return Category::INTEGER; }

    /// @returns the smallest integer type for the given literal or an empty pointer
    /// if no type fits.
    static std::shared_ptr<IntegerType> smallestTypeForLiteral(std::string const& _literal);

    explicit IntegerType(int _bits, Modifier _modifier = Modifier::UNSIGNED);

    virtual bool isImplicitlyConvertibleTo(Type const& _convertTo) const override;
    virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override;
    virtual bool acceptsBinaryOperator(Token::Value _operator) const override;
    virtual bool acceptsUnaryOperator(Token::Value _operator) const override;

    virtual bool operator==(Type const& _other) const override;

    virtual unsigned getCalldataEncodedSize() const { return m_bits / 8; }

    virtual std::string toString() const override;
    virtual u256 literalValue(Literal const& _literal) const override;

    int getNumBits() const { return m_bits; }
    bool isHash() const { return m_modifier == Modifier::HASH || m_modifier == Modifier::ADDRESS; }
    bool isAddress() const { return m_modifier == Modifier::ADDRESS; }
    int isSigned() const { return m_modifier == Modifier::SIGNED; }

private:
    int m_bits;
    Modifier m_modifier;
};

/**
 * The boolean type.
 */
class BoolType: public Type
{
public:
    virtual Category getCategory() const { return Category::BOOL; }
    virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override;
    virtual bool acceptsBinaryOperator(Token::Value _operator) const override
    {
        return _operator == Token::AND || _operator == Token::OR;
    }
    virtual bool acceptsUnaryOperator(Token::Value _operator) const override
    {
        return _operator == Token::NOT || _operator == Token::DELETE;
    }

    virtual unsigned getCalldataEncodedSize() const { return 1; }

    virtual std::string toString() const override { return "bool"; }
    virtual u256 literalValue(Literal const& _literal) const override;
};

/**
 * The type of a contract instance, there is one distinct type for each contract definition.
 */
class ContractType: public Type
{
public:
    virtual Category getCategory() const override { return Category::CONTRACT; }
    ContractType(ContractDefinition const& _contract): m_contract(_contract) {}

    virtual bool operator==(Type const& _other) const override;

    virtual std::string toString() const override { return "contract{...}"; }

private:
    ContractDefinition const& m_contract;
};

/**
 * The type of a struct instance, there is one distinct type per struct definition.
 */
class StructType: public Type
{
public:
    virtual Category getCategory() const override { return Category::STRUCT; }
    StructType(StructDefinition const& _struct): m_struct(_struct) {}
    virtual bool acceptsUnaryOperator(Token::Value _operator) const override
    {
        return _operator == Token::DELETE;
    }

    virtual bool operator==(Type const& _other) const override;

    virtual std::string toString() const override { return "struct{...}"; }

private:
    StructDefinition const& m_struct;
};

/**
 * The type of a function, there is one distinct type per function definition.
 */
class FunctionType: public Type
{
public:
    virtual Category getCategory() const override { return Category::FUNCTION; }
    FunctionType(FunctionDefinition const& _function): m_function(_function) {}

    FunctionDefinition const& getFunction() const { return m_function; }

    virtual std::string toString() const override { return "function(...)returns(...)"; }

    virtual bool operator==(Type const& _other) const override;

private:
    FunctionDefinition const& m_function;
};

/**
 * The type of a mapping, there is one distinct type per key/value type pair.
 */
class MappingType: public Type
{
public:
    virtual Category getCategory() const override { return Category::MAPPING; }
    MappingType() {}
    virtual std::string toString() const override { return "mapping(...=>...)"; }

    virtual bool operator==(Type const& _other) const override;

private:
    std::shared_ptr<Type const> m_keyType;
    std::shared_ptr<Type const> m_valueType;
};

/**
 * The void type, can only be implicitly used as the type that is returned by functions without
 * return parameters.
 */
class VoidType: public Type
{
public:
    virtual Category getCategory() const override { return Category::VOID; }
    VoidType() {}

    virtual std::string toString() const override { return "void"; }
};

/**
 * The type of a type reference. The type of "uint32" when used in "a = uint32(2)" is an example
 * of a TypeType.
 */
class TypeType: public Type
{
public:
    virtual Category getCategory() const override { return Category::TYPE; }
    TypeType(std::shared_ptr<Type const> const& _actualType): m_actualType(_actualType) {}

    std::shared_ptr<Type const> const& getActualType() const { return m_actualType; }

    virtual bool operator==(Type const& _other) const override;

    virtual std::string toString() const override { return "type(" + m_actualType->toString() + ")"; }

private:
    std::shared_ptr<Type const> m_actualType;
};


}
}