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/*
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.
*/
#include <libsolidity/CompilerUtils.h>
#include <libsolidity/AST.h>
#include <libevmcore/Instruction.h>
using namespace std;
namespace dev
{
namespace solidity
{
const unsigned int CompilerUtils::dataStartOffset = 4;
unsigned CompilerUtils::loadFromMemory(unsigned _offset, unsigned _bytes, bool _leftAligned,
bool _fromCalldata, bool _padToWordBoundaries)
{
if (_bytes == 0)
{
m_context << u256(0);
return 0;
}
eth::Instruction load = _fromCalldata ? eth::Instruction::CALLDATALOAD : eth::Instruction::MLOAD;
solAssert(_bytes <= 32, "Memory load of more than 32 bytes requested.");
if (_bytes == 32 || _padToWordBoundaries)
{
m_context << u256(_offset) << load;
return 32;
}
else
{
// load data and add leading or trailing zeros by dividing/multiplying depending on alignment
u256 shiftFactor = u256(1) << ((32 - _bytes) * 8);
m_context << shiftFactor;
if (_leftAligned)
m_context << eth::Instruction::DUP1;
m_context << u256(_offset) << load << eth::Instruction::DIV;
if (_leftAligned)
m_context << eth::Instruction::MUL;
return _bytes;
}
}
unsigned CompilerUtils::storeInMemory(unsigned _offset, unsigned _bytes, bool _leftAligned,
bool _padToWordBoundaries)
{
if (_bytes == 0)
{
m_context << eth::Instruction::POP;
return 0;
}
solAssert(_bytes <= 32, "Memory store of more than 32 bytes requested.");
if (_bytes != 32 && !_leftAligned && !_padToWordBoundaries)
// shift the value accordingly before storing
m_context << (u256(1) << ((32 - _bytes) * 8)) << eth::Instruction::MUL;
m_context << u256(_offset) << eth::Instruction::MSTORE;
return _padToWordBoundaries ? 32 : _bytes;
}
void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable)
{
unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.getBaseStackOffsetOfVariable(_variable));
unsigned const size = _variable.getType()->getSizeOnStack();
// move variable starting from its top end in the stack
if (stackPosition - size + 1 > 16)
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(_variable.getLocation())
<< errinfo_comment("Stack too deep."));
for (unsigned i = 0; i < size; ++i)
m_context << eth::swapInstruction(stackPosition - size + 1) << eth::Instruction::POP;
}
void CompilerUtils::copyToStackTop(unsigned _stackDepth, Type const& _type)
{
if (_stackDepth > 16)
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Stack too deep."));
unsigned const size = _type.getSizeOnStack();
for (unsigned i = 0; i < size; ++i)
m_context << eth::dupInstruction(_stackDepth);
}
void CompilerUtils::popStackElement(Type const& _type)
{
unsigned const size = _type.getSizeOnStack();
for (unsigned i = 0; i < size; ++i)
m_context << eth::Instruction::POP;
}
unsigned CompilerUtils::getSizeOnStack(vector<shared_ptr<Type const>> const& _variableTypes)
{
unsigned size = 0;
for (shared_ptr<Type const> const& type: _variableTypes)
size += type->getSizeOnStack();
return size;
}
}
}