path: root/CompilerUtils.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
 * Routines used by both the compiler and the expression compiler.
 */

#pragma once

#include <libsolidity/CompilerContext.h>
#include <libsolidity/ASTForward.h>

namespace dev {
namespace solidity {

class Type; // forward

class CompilerUtils
{
public:
    CompilerUtils(CompilerContext& _context): m_context(_context) {}

    /// Loads data from memory to the stack.
    /// @param _offset offset in memory (or calldata)
    /// @param _bytes number of bytes to load
    /// @param _leftAligned if true, store left aligned on stack (otherwise right aligned)
    /// @param _fromCalldata if true, load from calldata, not from memory
    /// @param _padToWordBoundaries if true, assume the data is padded to word (32 byte) boundaries
    /// @returns the number of bytes consumed in memory (can be different from _bytes if
    ///          _padToWordBoundaries is true)
    unsigned loadFromMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false,
                            bool _fromCalldata = false, bool _padToWordBoundaries = false);
    /// Stores data from stack in memory.
    /// @param _offset offset in memory
    /// @param _bytes number of bytes to store
    /// @param _leftAligned if true, data is left aligned on stack (otherwise right aligned)
    /// @param _padToWordBoundaries if true, pad the data to word (32 byte) boundaries
    /// @returns the number of bytes written to memory (can be different from _bytes if
    ///          _padToWordBoundaries is true)
    unsigned storeInMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false,
                           bool _padToWordBoundaries = false);
    /// @returns _size rounded up to the next multiple of 32 (the number of bytes occupied in the
    ///          padded calldata)
    static unsigned getPaddedSize(unsigned _size) { return ((_size + 31) / 32) * 32; }

    /// Moves the value that is at the top of the stack to a stack variable.
    void moveToStackVariable(VariableDeclaration const& _variable);
    /// Copies a variable of type @a _type from a stack depth of @a _stackDepth to the top of the stack.
    void copyToStackTop(unsigned _stackDepth, Type const& _type);
    /// Removes the current value from the top of the stack.
    void popStackElement(Type const& _type);

    template <class T>
    static unsigned getSizeOnStack(std::vector<T> const& _variables);
    static unsigned getSizeOnStack(std::vector<std::shared_ptr<Type const>> const& _variableTypes);

    /// Bytes we need to the start of call data.
    ///  - The size in bytes of the function (hash) identifier.
    static const unsigned int dataStartOffset;
private:
    CompilerContext& m_context;
};


template <class T>
unsigned CompilerUtils::getSizeOnStack(std::vector<T> const& _variables)
{
    unsigned size = 0;
    for (T const& variable: _variables)
        size += variable->getType()->getSizeOnStack();
    return size;
}

}
}