/*
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 2015
* LValues for use in the expresison compiler.
*/
#include <libsolidity/LValue.h>
#include <libevmcore/Instruction.h>
#include <libsolidity/Types.h>
#include <libsolidity/AST.h>
#include <libsolidity/CompilerUtils.h>
using namespace std;
using namespace dev;
using namespace solidity;
StackVariable::StackVariable(CompilerContext& _compilerContext, Declaration const& _declaration):
LValue(_compilerContext, *_declaration.getType()),
m_baseStackOffset(m_context.getBaseStackOffsetOfVariable(_declaration)),
m_size(m_dataType.getSizeOnStack())
{
}
void StackVariable::retrieveValue(SourceLocation const& _location, bool) const
{
unsigned stackPos = m_context.baseToCurrentStackOffset(m_baseStackOffset);
if (stackPos >= 15) //@todo correct this by fetching earlier or moving to memory
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(_location) << errinfo_comment("Stack too deep."));
for (unsigned i = 0; i < m_size; ++i)
m_context << eth::dupInstruction(stackPos + 1);
}
void StackVariable::storeValue(Type const&, SourceLocation const& _location, bool _move) const
{
unsigned stackDiff = m_context.baseToCurrentStackOffset(m_baseStackOffset) - m_size + 1;
if (stackDiff > 16)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(_location) << errinfo_comment("Stack too deep."));
else if (stackDiff > 0)
for (unsigned i = 0; i < m_size; ++i)
m_context << eth::swapInstruction(stackDiff) << eth::Instruction::POP;
if (!_move)
retrieveValue(_location);
}
void StackVariable::setToZero(SourceLocation const& _location, bool) const
{
unsigned stackDiff = m_context.baseToCurrentStackOffset(m_baseStackOffset);
if (stackDiff > 16)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(_location) << errinfo_comment("Stack too deep."));
solAssert(stackDiff >= m_size - 1, "");
for (unsigned i = 0; i < m_size; ++i)
m_context << u256(0) << eth::swapInstruction(stackDiff + 1 - i)
<< eth::Instruction::POP;
}
StorageItem::StorageItem(CompilerContext& _compilerContext, Declaration const& _declaration):
StorageItem(_compilerContext, *_declaration.getType())
{
auto const& location = m_context.getStorageLocationOfVariable(_declaration);
m_context << location.first << u256(location.second);
}
StorageItem::StorageItem(CompilerContext& _compilerContext, Type const& _type):
LValue(_compilerContext, _type)
{
if (m_dataType.isValueType())
{
solAssert(m_dataType.getStorageSize() == m_dataType.getSizeOnStack(), "");
solAssert(m_dataType.getStorageSize() == 1, "Invalid storage size.");
}
}
void StorageItem::retrieveValue(SourceLocation const&, bool _remove) const
{
// stack: storage_key storage_offset
if (!m_dataType.isValueType())
return; // no distinction between value and reference for non-value types
if (!_remove)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
if (m_dataType.getStorageBytes() == 32)
m_context << eth::Instruction::POP << eth::Instruction::SLOAD;
else
{
m_context
<< eth::Instruction::SWAP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP1
<< u256(0x100) << eth::Instruction::EXP << eth::Instruction::SWAP1 << eth::Instruction::DIV;
if (m_dataType.getCategory() == Type::Category::FixedBytes)
m_context << (u256(0x1) << (256 - 8 * m_dataType.getStorageBytes())) << eth::Instruction::MUL;
else if (
m_dataType.getCategory() == Type::Category::Integer &&
dynamic_cast<IntegerType const&>(m_dataType).isSigned()
)
m_context << u256(m_dataType.getStorageBytes() - 1) << eth::Instruction::SIGNEXTEND;
else
m_context << ((u256(0x1) << (8 * m_dataType.getStorageBytes())) - 1) << eth::Instruction::AND;
}
}
void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _location, bool _move) const
{
// stack: value storage_key storage_offset
if (m_dataType.isValueType())
{
solAssert(m_dataType.getStorageBytes() <= 32, "Invalid storage bytes size.");
solAssert(m_dataType.getStorageBytes() > 0, "Invalid storage bytes size.");
if (m_dataType.getStorageBytes() == 32)
{
// offset should be zero
m_context << eth::Instruction::POP;
if (!_move)
m_context << eth::Instruction::DUP2 << eth::Instruction::SWAP1;
m_context << eth::Instruction::SSTORE;
}
else
{
// OR the value into the other values in the storage slot
m_context << u256(0x100) << eth::Instruction::EXP;
// stack: value storage_ref multiplier
// fetch old value
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
// stack: value storege_ref multiplier old_full_value
// clear bytes in old value
m_context
<< eth::Instruction::DUP2 << ((u256(1) << (8 * m_dataType.getStorageBytes())) - 1)
<< eth::Instruction::MUL;
m_context << eth::Instruction::NOT << eth::Instruction::AND;
// stack: value storage_ref multiplier cleared_value
m_context
<< eth::Instruction::SWAP1 << eth::Instruction::DUP4;
// stack: value storage_ref cleared_value multiplier value
if (m_dataType.getCategory() == Type::Category::FixedBytes)
m_context
<< (u256(0x1) << (256 - 8 * dynamic_cast<FixedBytesType const&>(m_dataType).getNumBytes()))
<< eth::Instruction::SWAP1 << eth::Instruction::DIV;
else if (
m_dataType.getCategory() == Type::Category::Integer &&
dynamic_cast<IntegerType const&>(m_dataType).isSigned()
)
// remove the higher order bits
m_context
<< (u256(1) << (8 * (32 - m_dataType.getStorageBytes())))
<< eth::Instruction::SWAP1
<< eth::Instruction::DUP2
<< eth::Instruction::MUL
<< eth::Instruction::DIV;
m_context << eth::Instruction::MUL << eth::Instruction::OR;
// stack: value storage_ref updated_value
m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
if (_move)
m_context << eth::Instruction::POP;
}
}
else
{
solAssert(
_sourceType.getCategory() == m_dataType.getCategory(),
"Wrong type conversation for assignment.");
if (m_dataType.getCategory() == Type::Category::Array)
{
ArrayUtils(m_context).copyArrayToStorage(
dynamic_cast<ArrayType const&>(m_dataType),
dynamic_cast<ArrayType const&>(_sourceType));
if (_move)
CompilerUtils(m_context).popStackElement(_sourceType);
}
else if (m_dataType.getCategory() == Type::Category::Struct)
{
// stack layout: source_ref source_offset target_ref target_offset
// note that we have structs, so offsets should be zero and are ignored
auto const& structType = dynamic_cast<StructType const&>(m_dataType);
solAssert(structType == _sourceType, "Struct assignment with conversion.");
for (auto const& member: structType.getMembers())
{
// assign each member that is not a mapping
TypePointer const& memberType = member.type;
if (memberType->getCategory() == Type::Category::Mapping)
continue;
pair<u256, unsigned> const& offsets = structType.getStorageOffsetsOfMember(member.name);
m_context
<< offsets.first << u256(offsets.second)
<< eth::Instruction::DUP6 << eth::Instruction::DUP3
<< eth::Instruction::ADD << eth::Instruction::DUP2;
// stack: source_ref source_off target_ref target_off member_slot_offset member_byte_offset source_member_ref source_member_off
StorageItem(m_context, *memberType).retrieveValue(_location, true);
// stack: source_ref source_off target_ref target_off member_offset source_value...
solAssert(4 + memberType->getSizeOnStack() <= 16, "Stack too deep.");
m_context
<< eth::dupInstruction(4 + memberType->getSizeOnStack())
<< eth::dupInstruction(3 + memberType->getSizeOnStack()) << eth::Instruction::ADD
<< eth::dupInstruction(2 + memberType->getSizeOnStack());
// stack: source_ref source_off target_ref target_off member_slot_offset member_byte_offset source_value... target_member_ref target_member_byte_off
StorageItem(m_context, *memberType).storeValue(*memberType, _location, true);
m_context << eth::Instruction::POP << eth::Instruction::POP;
}
if (_move)
m_context
<< eth::Instruction::POP << eth::Instruction::POP
<< eth::Instruction::POP << eth::Instruction::POP;
else
m_context
<< eth::Instruction::SWAP2 << eth::Instruction::POP
<< eth::Instruction::SWAP2 << eth::Instruction::POP;
}
else
BOOST_THROW_EXCEPTION(
InternalCompilerError()
<< errinfo_sourceLocation(_location)
<< errinfo_comment("Invalid non-value type for assignment."));
}
}
void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
{
if (m_dataType.getCategory() == Type::Category::Array)
{
if (!_removeReference)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
ArrayUtils(m_context).clearArray(dynamic_cast<ArrayType const&>(m_dataType));
}
else if (m_dataType.getCategory() == Type::Category::Struct)
{
// stack layout: storage_key storage_offset
// @todo this can be improved: use StorageItem for non-value types, and just store 0 in
// all slots that contain value types later.
auto const& structType = dynamic_cast<StructType const&>(m_dataType);
for (auto const& member: structType.getMembers())
{
// zero each member that is not a mapping
TypePointer const& memberType = member.type;
if (memberType->getCategory() == Type::Category::Mapping)
continue;
pair<u256, unsigned> const& offsets = structType.getStorageOffsetsOfMember(member.name);
m_context
<< offsets.first << eth::Instruction::DUP3 << eth::Instruction::ADD
<< u256(offsets.second);
StorageItem(m_context, *memberType).setToZero();
}
if (_removeReference)
m_context << eth::Instruction::POP << eth::Instruction::POP;
}
else
{
solAssert(m_dataType.isValueType(), "Clearing of unsupported type requested: " + m_dataType.toString());
if (!_removeReference)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
if (m_dataType.getStorageBytes() == 32)
{
// offset should be zero
m_context
<< eth::Instruction::POP << u256(0)
<< eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
}
else
{
m_context << u256(0x100) << eth::Instruction::EXP;
// stack: storage_ref multiplier
// fetch old value
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
// stack: storege_ref multiplier old_full_value
// clear bytes in old value
m_context
<< eth::Instruction::SWAP1 << ((u256(1) << (8 * m_dataType.getStorageBytes())) - 1)
<< eth::Instruction::MUL;
m_context << eth::Instruction::NOT << eth::Instruction::AND;
// stack: storage_ref cleared_value
m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
}
}
}
/// Used in StorageByteArrayElement
static FixedBytesType byteType(1);
StorageByteArrayElement::StorageByteArrayElement(CompilerContext& _compilerContext):
LValue(_compilerContext, byteType)
{
}
void StorageByteArrayElement::retrieveValue(SourceLocation const&, bool _remove) const
{
// stack: ref byte_number
if (_remove)
m_context << eth::Instruction::SWAP1 << eth::Instruction::SLOAD
<< eth::Instruction::SWAP1 << eth::Instruction::BYTE;
else
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD
<< eth::Instruction::DUP2 << eth::Instruction::BYTE;
m_context << (u256(1) << (256 - 8)) << eth::Instruction::MUL;
}
void StorageByteArrayElement::storeValue(Type const&, SourceLocation const&, bool _move) const
{
// stack: value ref byte_number
m_context << u256(31) << eth::Instruction::SUB << u256(0x100) << eth::Instruction::EXP;
// stack: value ref (1<<(8*(31-byte_number)))
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
// stack: value ref (1<<(8*(31-byte_number))) old_full_value
// clear byte in old value
m_context << eth::Instruction::DUP2 << u256(0xff) << eth::Instruction::MUL
<< eth::Instruction::NOT << eth::Instruction::AND;
// stack: value ref (1<<(32-byte_number)) old_full_value_with_cleared_byte
m_context << eth::Instruction::SWAP1;
m_context << (u256(1) << (256 - 8)) << eth::Instruction::DUP5 << eth::Instruction::DIV
<< eth::Instruction::MUL << eth::Instruction::OR;
// stack: value ref new_full_value
m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
if (_move)
m_context << eth::Instruction::POP;
}
void StorageByteArrayElement::setToZero(SourceLocation const&, bool _removeReference) const
{
// stack: ref byte_number
if (!_removeReference)
m_context << eth::Instruction::DUP2 << eth::Instruction::DUP2;
m_context << u256(31) << eth::Instruction::SUB << u256(0x100) << eth::Instruction::EXP;
// stack: ref (1<<(8*(31-byte_number)))
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
// stack: ref (1<<(8*(31-byte_number))) old_full_value
// clear byte in old value
m_context << eth::Instruction::SWAP1 << u256(0xff) << eth::Instruction::MUL;
m_context << eth::Instruction::NOT << eth::Instruction::AND;
// stack: ref old_full_value_with_cleared_byte
m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
}
StorageArrayLength::StorageArrayLength(CompilerContext& _compilerContext, const ArrayType& _arrayType):
LValue(_compilerContext, *_arrayType.getMemberType("length")),
m_arrayType(_arrayType)
{
solAssert(m_arrayType.isDynamicallySized(), "");
// storage byte offset must be zero
m_context << eth::Instruction::POP;
}
void StorageArrayLength::retrieveValue(SourceLocation const&, bool _remove) const
{
if (!_remove)
m_context << eth::Instruction::DUP1;
m_context << eth::Instruction::SLOAD;
}
void StorageArrayLength::storeValue(Type const&, SourceLocation const&, bool _move) const
{
if (_move)
m_context << eth::Instruction::SWAP1;
else
m_context << eth::Instruction::DUP2;
ArrayUtils(m_context).resizeDynamicArray(m_arrayType);
}
void StorageArrayLength::setToZero(SourceLocation const&, bool _removeReference) const
{
if (!_removeReference)
m_context << eth::Instruction::DUP1;
ArrayUtils(m_context).clearDynamicArray(m_arrayType);
}
