You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
107 lines
3.2 KiB
107 lines
3.2 KiB
/*
|
|
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/>.
|
|
*/
|
|
/**
|
|
* @file SemanticInformation.cpp
|
|
* @author Christian <c@ethdev.com>
|
|
* @date 2015
|
|
* Helper to provide semantic information about assembly items.
|
|
*/
|
|
|
|
#include <libevmcore/SemanticInformation.h>
|
|
#include <libevmcore/AssemblyItem.h>
|
|
|
|
using namespace std;
|
|
using namespace dev;
|
|
using namespace dev::eth;
|
|
|
|
bool SemanticInformation::breaksCSEAnalysisBlock(AssemblyItem const& _item)
|
|
{
|
|
switch (_item.type())
|
|
{
|
|
default:
|
|
case UndefinedItem:
|
|
case Tag:
|
|
return true;
|
|
case Push:
|
|
case PushString:
|
|
case PushTag:
|
|
case PushSub:
|
|
case PushSubSize:
|
|
case PushProgramSize:
|
|
case PushData:
|
|
return false;
|
|
case Operation:
|
|
{
|
|
if (isSwapInstruction(_item) || isDupInstruction(_item))
|
|
return false;
|
|
if (_item.instruction() == Instruction::GAS || _item.instruction() == Instruction::PC)
|
|
return true; // GAS and PC assume a specific order of opcodes
|
|
if (_item.instruction() == Instruction::MSIZE)
|
|
return true; // msize is modified already by memory access, avoid that for now
|
|
if (_item.instruction() == Instruction::SHA3)
|
|
return true; //@todo: we have to compare sha3's not based on their memory addresses but on the memory content.
|
|
InstructionInfo info = instructionInfo(_item.instruction());
|
|
if (_item.instruction() == Instruction::SSTORE)
|
|
return false;
|
|
if (_item.instruction() == Instruction::MSTORE)
|
|
return false;
|
|
//@todo: We do not handle the following memory instructions for now:
|
|
// calldatacopy, codecopy, extcodecopy, mstore8,
|
|
// msize (note that msize also depends on memory read access)
|
|
|
|
// the second requirement will be lifted once it is implemented
|
|
return info.sideEffects || info.args > 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::isCommutativeOperation(AssemblyItem const& _item)
|
|
{
|
|
if (_item.type() != Operation)
|
|
return false;
|
|
switch (_item.instruction())
|
|
{
|
|
case Instruction::ADD:
|
|
case Instruction::MUL:
|
|
case Instruction::EQ:
|
|
case Instruction::AND:
|
|
case Instruction::OR:
|
|
case Instruction::XOR:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::isDupInstruction(AssemblyItem const& _item)
|
|
{
|
|
if (_item.type() != Operation)
|
|
return false;
|
|
return Instruction::DUP1 <= _item.instruction() && _item.instruction() <= Instruction::DUP16;
|
|
}
|
|
|
|
bool SemanticInformation::isSwapInstruction(AssemblyItem const& _item)
|
|
{
|
|
if (_item.type() != Operation)
|
|
return false;
|
|
return Instruction::SWAP1 <= _item.instruction() && _item.instruction() <= Instruction::SWAP16;
|
|
}
|
|
|
|
bool SemanticInformation::isJumpInstruction(AssemblyItem const& _item)
|
|
{
|
|
return _item == AssemblyItem(Instruction::JUMP) || _item == AssemblyItem(Instruction::JUMPI);
|
|
}
|
|
|