mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
521 lines
14 KiB
C++
521 lines
14 KiB
C++
/*
|
|
This file is part of solidity.
|
|
|
|
solidity 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.
|
|
|
|
solidity 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 solidity. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
// SPDX-License-Identifier: GPL-3.0
|
|
/**
|
|
* @file SemanticInformation.cpp
|
|
* @author Christian <c@ethdev.com>
|
|
* @date 2015
|
|
* Helper to provide semantic information about assembly items.
|
|
*/
|
|
|
|
#include <libevmasm/SemanticInformation.h>
|
|
#include <libevmasm/AssemblyItem.h>
|
|
|
|
using namespace std;
|
|
using namespace solidity;
|
|
using namespace solidity::evmasm;
|
|
|
|
vector<SemanticInformation::Operation> SemanticInformation::readWriteOperations(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::SSTORE:
|
|
case Instruction::SLOAD:
|
|
{
|
|
assertThrow(memory(_instruction) == Effect::None, OptimizerException, "");
|
|
assertThrow(storage(_instruction) != Effect::None, OptimizerException, "");
|
|
Operation op;
|
|
op.effect = storage(_instruction);
|
|
op.location = Location::Storage;
|
|
op.startParameter = 0;
|
|
// We know that exactly one slot is affected.
|
|
op.lengthConstant = 1;
|
|
return {op};
|
|
}
|
|
case Instruction::MSTORE:
|
|
case Instruction::MSTORE8:
|
|
case Instruction::MLOAD:
|
|
{
|
|
assertThrow(memory(_instruction) != Effect::None, OptimizerException, "");
|
|
assertThrow(storage(_instruction) == Effect::None, OptimizerException, "");
|
|
Operation op;
|
|
op.effect = memory(_instruction);
|
|
op.location = Location::Memory;
|
|
op.startParameter = 0;
|
|
if (_instruction == Instruction::MSTORE || _instruction == Instruction::MLOAD)
|
|
op.lengthConstant = 32;
|
|
else if (_instruction == Instruction::MSTORE8)
|
|
op.lengthConstant = 1;
|
|
|
|
return {op};
|
|
}
|
|
case Instruction::REVERT:
|
|
case Instruction::RETURN:
|
|
case Instruction::KECCAK256:
|
|
case Instruction::LOG0:
|
|
case Instruction::LOG1:
|
|
case Instruction::LOG2:
|
|
case Instruction::LOG3:
|
|
case Instruction::LOG4:
|
|
{
|
|
assertThrow(storage(_instruction) == Effect::None, OptimizerException, "");
|
|
assertThrow(memory(_instruction) == Effect::Read, OptimizerException, "");
|
|
Operation op;
|
|
op.effect = memory(_instruction);
|
|
op.location = Location::Memory;
|
|
op.startParameter = 0;
|
|
op.lengthParameter = 1;
|
|
return {op};
|
|
}
|
|
case Instruction::EXTCODECOPY:
|
|
{
|
|
assertThrow(memory(_instruction) == Effect::Write, OptimizerException, "");
|
|
assertThrow(storage(_instruction) == Effect::None, OptimizerException, "");
|
|
Operation op;
|
|
op.effect = memory(_instruction);
|
|
op.location = Location::Memory;
|
|
op.startParameter = 1;
|
|
op.lengthParameter = 3;
|
|
return {op};
|
|
}
|
|
case Instruction::CODECOPY:
|
|
case Instruction::CALLDATACOPY:
|
|
case Instruction::RETURNDATACOPY:
|
|
{
|
|
assertThrow(memory(_instruction) == Effect::Write, OptimizerException, "");
|
|
assertThrow(storage(_instruction) == Effect::None, OptimizerException, "");
|
|
Operation op;
|
|
op.effect = memory(_instruction);
|
|
op.location = Location::Memory;
|
|
op.startParameter = 0;
|
|
op.lengthParameter = 2;
|
|
return {op};
|
|
}
|
|
case Instruction::STATICCALL:
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
{
|
|
size_t paramCount = static_cast<size_t>(instructionInfo(_instruction).args);
|
|
vector<Operation> operations{
|
|
Operation{Location::Memory, Effect::Read, paramCount - 4, paramCount - 3, {}},
|
|
Operation{Location::Storage, Effect::Read, {}, {}, {}}
|
|
};
|
|
if (_instruction != Instruction::STATICCALL)
|
|
operations.emplace_back(Operation{Location::Storage, Effect::Write, {}, {}, {}});
|
|
operations.emplace_back(Operation{
|
|
Location::Memory,
|
|
Effect::Write,
|
|
paramCount - 2,
|
|
// Length is in paramCount - 1, but it is only a max length,
|
|
// there is no guarantee that the full area is written to.
|
|
{},
|
|
{}
|
|
});
|
|
return operations;
|
|
}
|
|
case Instruction::CREATE:
|
|
case Instruction::CREATE2:
|
|
return vector<Operation>{
|
|
Operation{
|
|
Location::Memory,
|
|
Effect::Read,
|
|
1,
|
|
2,
|
|
{}
|
|
},
|
|
Operation{Location::Storage, Effect::Read, {}, {}, {}},
|
|
Operation{Location::Storage, Effect::Write, {}, {}, {}}
|
|
};
|
|
case Instruction::MSIZE:
|
|
// This is just to satisfy the assert below.
|
|
return vector<Operation>{};
|
|
default:
|
|
assertThrow(storage(_instruction) == None && memory(_instruction) == None, AssemblyException, "");
|
|
}
|
|
return {};
|
|
}
|
|
|
|
bool SemanticInformation::breaksCSEAnalysisBlock(AssemblyItem const& _item, bool _msizeImportant)
|
|
{
|
|
switch (_item.type())
|
|
{
|
|
default:
|
|
case UndefinedItem:
|
|
case Tag:
|
|
case PushDeployTimeAddress:
|
|
case AssignImmutable:
|
|
case VerbatimBytecode:
|
|
return true;
|
|
case Push:
|
|
case PushTag:
|
|
case PushSub:
|
|
case PushSubSize:
|
|
case PushProgramSize:
|
|
case PushData:
|
|
case PushLibraryAddress:
|
|
case PushImmutable:
|
|
return false;
|
|
case evmasm::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
|
|
InstructionInfo info = instructionInfo(_item.instruction());
|
|
if (_item.instruction() == Instruction::SSTORE)
|
|
return false;
|
|
if (_item.instruction() == Instruction::MSTORE)
|
|
return false;
|
|
if (!_msizeImportant && (
|
|
_item.instruction() == Instruction::MLOAD ||
|
|
_item.instruction() == Instruction::KECCAK256
|
|
))
|
|
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() != evmasm::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() != evmasm::Operation)
|
|
return false;
|
|
return evmasm::isDupInstruction(_item.instruction());
|
|
}
|
|
|
|
bool SemanticInformation::isSwapInstruction(AssemblyItem const& _item)
|
|
{
|
|
if (_item.type() != evmasm::Operation)
|
|
return false;
|
|
return evmasm::isSwapInstruction(_item.instruction());
|
|
}
|
|
|
|
bool SemanticInformation::isJumpInstruction(AssemblyItem const& _item)
|
|
{
|
|
return _item == Instruction::JUMP || _item == Instruction::JUMPI;
|
|
}
|
|
|
|
bool SemanticInformation::altersControlFlow(AssemblyItem const& _item)
|
|
{
|
|
if (_item.type() != evmasm::Operation)
|
|
return false;
|
|
switch (_item.instruction())
|
|
{
|
|
// note that CALL, CALLCODE and CREATE do not really alter the control flow, because we
|
|
// continue on the next instruction
|
|
case Instruction::JUMP:
|
|
case Instruction::JUMPI:
|
|
case Instruction::RETURN:
|
|
case Instruction::SELFDESTRUCT:
|
|
case Instruction::STOP:
|
|
case Instruction::INVALID:
|
|
case Instruction::REVERT:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::terminatesControlFlow(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::RETURN:
|
|
case Instruction::SELFDESTRUCT:
|
|
case Instruction::STOP:
|
|
case Instruction::INVALID:
|
|
case Instruction::REVERT:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::reverts(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::INVALID:
|
|
case Instruction::REVERT:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::isDeterministic(AssemblyItem const& _item)
|
|
{
|
|
assertThrow(_item.type() != VerbatimBytecode, AssemblyException, "");
|
|
|
|
if (_item.type() != evmasm::Operation)
|
|
return true;
|
|
|
|
switch (_item.instruction())
|
|
{
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
case Instruction::STATICCALL:
|
|
case Instruction::CREATE:
|
|
case Instruction::CREATE2:
|
|
case Instruction::GAS:
|
|
case Instruction::PC:
|
|
case Instruction::MSIZE: // depends on previous writes and reads, not only on content
|
|
case Instruction::BALANCE: // depends on previous calls
|
|
case Instruction::SELFBALANCE: // depends on previous calls
|
|
case Instruction::EXTCODESIZE:
|
|
case Instruction::EXTCODEHASH:
|
|
case Instruction::RETURNDATACOPY: // depends on previous calls
|
|
case Instruction::RETURNDATASIZE:
|
|
return false;
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::movable(Instruction _instruction)
|
|
{
|
|
// These are not really functional.
|
|
if (isDupInstruction(_instruction) || isSwapInstruction(_instruction))
|
|
return false;
|
|
InstructionInfo info = instructionInfo(_instruction);
|
|
if (info.sideEffects)
|
|
return false;
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::KECCAK256:
|
|
case Instruction::BALANCE:
|
|
case Instruction::SELFBALANCE:
|
|
case Instruction::EXTCODESIZE:
|
|
case Instruction::EXTCODEHASH:
|
|
case Instruction::RETURNDATASIZE:
|
|
case Instruction::SLOAD:
|
|
case Instruction::PC:
|
|
case Instruction::MSIZE:
|
|
case Instruction::GAS:
|
|
return false;
|
|
default:
|
|
return true;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool SemanticInformation::canBeRemoved(Instruction _instruction)
|
|
{
|
|
// These are not really functional.
|
|
assertThrow(!isDupInstruction(_instruction) && !isSwapInstruction(_instruction), AssemblyException, "");
|
|
|
|
return !instructionInfo(_instruction).sideEffects;
|
|
}
|
|
|
|
bool SemanticInformation::canBeRemovedIfNoMSize(Instruction _instruction)
|
|
{
|
|
if (_instruction == Instruction::KECCAK256 || _instruction == Instruction::MLOAD)
|
|
return true;
|
|
else
|
|
return canBeRemoved(_instruction);
|
|
}
|
|
|
|
SemanticInformation::Effect SemanticInformation::memory(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::CALLDATACOPY:
|
|
case Instruction::CODECOPY:
|
|
case Instruction::EXTCODECOPY:
|
|
case Instruction::RETURNDATACOPY:
|
|
case Instruction::MSTORE:
|
|
case Instruction::MSTORE8:
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
case Instruction::STATICCALL:
|
|
return SemanticInformation::Write;
|
|
|
|
case Instruction::CREATE:
|
|
case Instruction::CREATE2:
|
|
case Instruction::KECCAK256:
|
|
case Instruction::MLOAD:
|
|
case Instruction::MSIZE:
|
|
case Instruction::RETURN:
|
|
case Instruction::REVERT:
|
|
case Instruction::LOG0:
|
|
case Instruction::LOG1:
|
|
case Instruction::LOG2:
|
|
case Instruction::LOG3:
|
|
case Instruction::LOG4:
|
|
return SemanticInformation::Read;
|
|
|
|
default:
|
|
return SemanticInformation::None;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::movableApartFromEffects(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::EXTCODEHASH:
|
|
case Instruction::EXTCODESIZE:
|
|
case Instruction::RETURNDATASIZE:
|
|
case Instruction::BALANCE:
|
|
case Instruction::SELFBALANCE:
|
|
case Instruction::SLOAD:
|
|
case Instruction::KECCAK256:
|
|
case Instruction::MLOAD:
|
|
return true;
|
|
|
|
default:
|
|
return movable(_instruction);
|
|
}
|
|
}
|
|
|
|
SemanticInformation::Effect SemanticInformation::storage(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
case Instruction::CREATE:
|
|
case Instruction::CREATE2:
|
|
case Instruction::SSTORE:
|
|
return SemanticInformation::Write;
|
|
|
|
case Instruction::SLOAD:
|
|
case Instruction::STATICCALL:
|
|
return SemanticInformation::Read;
|
|
|
|
default:
|
|
return SemanticInformation::None;
|
|
}
|
|
}
|
|
|
|
SemanticInformation::Effect SemanticInformation::otherState(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
case Instruction::CREATE:
|
|
case Instruction::CREATE2:
|
|
case Instruction::SELFDESTRUCT:
|
|
case Instruction::STATICCALL: // because it can affect returndatasize
|
|
// Strictly speaking, log0, .., log4 writes to the state, but the EVM cannot read it, so they
|
|
// are just marked as having 'other side effects.'
|
|
return SemanticInformation::Write;
|
|
|
|
case Instruction::EXTCODESIZE:
|
|
case Instruction::EXTCODEHASH:
|
|
case Instruction::RETURNDATASIZE:
|
|
case Instruction::BALANCE:
|
|
case Instruction::SELFBALANCE:
|
|
case Instruction::RETURNDATACOPY:
|
|
case Instruction::EXTCODECOPY:
|
|
// PC and GAS are specifically excluded here. Instructions such as CALLER, CALLVALUE,
|
|
// ADDRESS are excluded because they cannot change during execution.
|
|
return SemanticInformation::Read;
|
|
|
|
default:
|
|
return SemanticInformation::None;
|
|
}
|
|
}
|
|
|
|
bool SemanticInformation::invalidInPureFunctions(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::ADDRESS:
|
|
case Instruction::SELFBALANCE:
|
|
case Instruction::BALANCE:
|
|
case Instruction::ORIGIN:
|
|
case Instruction::CALLER:
|
|
case Instruction::CALLVALUE:
|
|
case Instruction::CHAINID:
|
|
case Instruction::BASEFEE:
|
|
case Instruction::GAS:
|
|
case Instruction::GASPRICE:
|
|
case Instruction::EXTCODESIZE:
|
|
case Instruction::EXTCODECOPY:
|
|
case Instruction::EXTCODEHASH:
|
|
case Instruction::BLOCKHASH:
|
|
case Instruction::COINBASE:
|
|
case Instruction::TIMESTAMP:
|
|
case Instruction::NUMBER:
|
|
case Instruction::DIFFICULTY:
|
|
case Instruction::GASLIMIT:
|
|
case Instruction::STATICCALL:
|
|
case Instruction::SLOAD:
|
|
return true;
|
|
default:
|
|
break;
|
|
}
|
|
return invalidInViewFunctions(_instruction);
|
|
}
|
|
|
|
bool SemanticInformation::invalidInViewFunctions(Instruction _instruction)
|
|
{
|
|
switch (_instruction)
|
|
{
|
|
case Instruction::SSTORE:
|
|
case Instruction::JUMP:
|
|
case Instruction::JUMPI:
|
|
case Instruction::LOG0:
|
|
case Instruction::LOG1:
|
|
case Instruction::LOG2:
|
|
case Instruction::LOG3:
|
|
case Instruction::LOG4:
|
|
case Instruction::CREATE:
|
|
case Instruction::CALL:
|
|
case Instruction::CALLCODE:
|
|
case Instruction::DELEGATECALL:
|
|
case Instruction::CREATE2:
|
|
case Instruction::SELFDESTRUCT:
|
|
return true;
|
|
default:
|
|
break;
|
|
}
|
|
return false;
|
|
}
|