// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package vm
import (
"errors"
"math/big"
"github.com/dexon-foundation/dexon/params"
)
type (
executionFunc func(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error)
gasFunc func(params.GasTable, *EVM, *Contract, *Stack, *Memory, uint64) (uint64, error) // last parameter is the requested memory size as a uint64
stackValidationFunc func(*Stack) error
memorySizeFunc func(*Stack) *big.Int
)
var errGasUintOverflow = errors.New("gas uint64 overflow")
type operation struct {
// execute is the operation function
execute executionFunc
// gasCost is the gas function and returns the gas required for execution
gasCost gasFunc
// validateStack validates the stack (size) for the operation
validateStack stackValidationFunc
// memorySize returns the memory size required for the operation
memorySize memorySizeFunc
halts bool // indicates whether the operation should halt further execution
jumps bool // indicates whether the program counter should not increment
writes bool // determines whether this a state modifying operation
valid bool // indication whether the retrieved operation is valid and known
reverts bool // determines whether the operation reverts state (implicitly halts)
returns bool // determines whether the operations sets the return data content
}
var (
frontierInstructionSet = newFrontierInstructionSet()
homesteadInstructionSet = newHomesteadInstructionSet()
byzantiumInstructionSet = newByzantiumInstructionSet()
constantinopleInstructionSet = newConstantinopleInstructionSet()
)
// NewConstantinopleInstructionSet returns the frontier, homestead
// byzantium and contantinople instructions.
func newConstantinopleInstructionSet() [256]operation {
// instructions that can be executed during the byzantium phase.
instructionSet := newByzantiumInstructionSet()
instructionSet[SHL] = operation{
execute: opSHL,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
}
instructionSet[SHR] = operation{
execute: opSHR,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
}
instructionSet[SAR] = operation{
execute: opSAR,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
}
instructionSet[EXTCODEHASH] = operation{
execute: opExtCodeHash,
gasCost: gasExtCodeHash,
validateStack: makeStackFunc(1, 1),
valid: true,
}
instructionSet[CREATE2] = operation{
execute: opCreate2,
gasCost: gasCreate2,
validateStack: makeStackFunc(4, 1),
memorySize: memoryCreate2,
valid: true,
writes: true,
returns: true,
}
return instructionSet
}
// NewByzantiumInstructionSet returns the frontier, homestead and
// byzantium instructions.
func newByzantiumInstructionSet() [256]operation {
// instructions that can be executed during the homestead phase.
instructionSet := newHomesteadInstructionSet()
instructionSet[STATICCALL] = operation{
execute: opStaticCall,
gasCost: gasStaticCall,
validateStack: makeStackFunc(6, 1),
memorySize: memoryStaticCall,
valid: true,
returns: true,
}
instructionSet[RETURNDATASIZE] = operation{
execute: opReturnDataSize,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
}
instructionSet[RETURNDATACOPY] = operation{
execute: opReturnDataCopy,
gasCost: gasReturnDataCopy,
validateStack: makeStackFunc(3, 0),
memorySize: memoryReturnDataCopy,
valid: true,
}
instructionSet[REVERT] = operation{
execute: opRevert,
gasCost: gasRevert,
validateStack: makeStackFunc(2, 0),
memorySize: memoryRevert,
valid: true,
reverts: true,
returns: true,
}
return instructionSet
}
// NewHomesteadInstructionSet returns the frontier and homestead
// instructions that can be executed during the homestead phase.
func newHomesteadInstructionSet() [256]operation {
instructionSet := newFrontierInstructionSet()
instructionSet[DELEGATECALL] = operation{
execute: opDelegateCall,
gasCost: gasDelegateCall,
validateStack: makeStackFunc(6, 1),
memorySize: memoryDelegateCall,
valid: true,
returns: true,
}
return instructionSet
}
// NewFrontierInstructionSet returns the frontier instructions
// that can be executed during the frontier phase.
func newFrontierInstructionSet() [256]operation {
return [256]operation{
STOP: {
execute: opStop,
gasCost: constGasFunc(0),
validateStack: makeStackFunc(0, 0),
halts: true,
valid: true,
},
ADD: {
execute: opAdd,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
MUL: {
execute: opMul,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SUB: {
execute: opSub,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
DIV: {
execute: opDiv,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SDIV: {
execute: opSdiv,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
MOD: {
execute: opMod,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SMOD: {
execute: opSmod,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
ADDMOD: {
execute: opAddmod,
gasCost: constGasFunc(GasMidStep),
validateStack: makeStackFunc(3, 1),
valid: true,
},
MULMOD: {
execute: opMulmod,
gasCost: constGasFunc(GasMidStep),
validateStack: makeStackFunc(3, 1),
valid: true,
},
EXP: {
execute: opExp,
gasCost: gasExp,
validateStack: makeStackFunc(2, 1),
valid: true,
},
SIGNEXTEND: {
execute: opSignExtend,
gasCost: constGasFunc(GasFastStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
LT: {
execute: opLt,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
GT: {
execute: opGt,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SLT: {
execute: opSlt,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SGT: {
execute: opSgt,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
EQ: {
execute: opEq,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
ISZERO: {
execute: opIszero,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(1, 1),
valid: true,
},
AND: {
execute: opAnd,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
XOR: {
execute: opXor,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
OR: {
execute: opOr,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
NOT: {
execute: opNot,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(1, 1),
valid: true,
},
BYTE: {
execute: opByte,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(2, 1),
valid: true,
},
SHA3: {
execute: opSha3,
gasCost: gasSha3,
validateStack: makeStackFunc(2, 1),
memorySize: memorySha3,
valid: true,
},
RAND: {
execute: opRand,
gasCost: constGasFunc(params.RandGas),
validateStack: makeStackFunc(0, 1),
valid: true,
},
ADDRESS: {
execute: opAddress,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
BALANCE: {
execute: opBalance,
gasCost: gasBalance,
validateStack: makeStackFunc(1, 1),
valid: true,
},
ORIGIN: {
execute: opOrigin,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
CALLER: {
execute: opCaller,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
CALLVALUE: {
execute: opCallValue,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
CALLDATALOAD: {
execute: opCallDataLoad,
gasCost: constGasFunc(GasFastestStep),
validateStack: makeStackFunc(1, 1),
valid: true,
},
CALLDATASIZE: {
execute: opCallDataSize,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
CALLDATACOPY: {
execute: opCallDataCopy,
gasCost: gasCallDataCopy,
validateStack: makeStackFunc(3, 0),
memorySize: memoryCallDataCopy,
valid: true,
},
CODESIZE: {
execute: opCodeSize,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
CODECOPY: {
execute: opCodeCopy,
gasCost: gasCodeCopy,
validateStack: makeStackFunc(3, 0),
memorySize: memoryCodeCopy,
valid: true,
},
GASPRICE: {
execute: opGasprice,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
EXTCODESIZE: {
execute: opExtCodeSize,
gasCost: gasExtCodeSize,
validateStack: makeStackFunc(1, 1),
valid: true,
},
EXTCODECOPY: {
execute: opExtCodeCopy,
gasCost: gasExtCodeCopy,
validateStack: makeStackFunc(4, 0),
memorySize: memoryExtCodeCopy,
valid: true,
},
BLOCKHASH: {
execute: opBlockhash,
gasCost: constGasFunc(GasExtStep),
validateStack: makeStackFunc(1, 1),
valid: true,
},
COINBASE: {
execute: opCoinbase,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
TIMESTAMP: {
execute: opTimestamp,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
NUMBER: {
execute: opNumber,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
DIFFICULTY: {
execute: opDifficulty,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
GASLIMIT: {
execute: opGasLimit,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
POP: {
execute: opPop,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(1, 0),
valid: true,
},
MLOAD: {
execute: opMload,
gasCost: gasMLoad,
validateStack: makeStackFunc(1, 1),
memorySize: memoryMLoad,
valid: true,
},
MSTORE: {
execute: opMstore,
gasCost: gasMStore,
validateStack: makeStackFunc(2, 0),
memorySize: memoryMStore,
valid: true,
},
MSTORE8: {
execute: opMstore8,
gasCost: gasMStore8,
memorySize: memoryMStore8,
validateStack: makeStackFunc(2, 0),
valid: true,
},
SLOAD: {
execute: opSload,
gasCost: gasSLoad,
validateStack: makeStackFunc(1, 1),
valid: true,
},
SSTORE: {
execute: opSstore,
gasCost: gasSStore,
validateStack: makeStackFunc(2, 0),
valid: true,
writes: true,
},
JUMP: {
execute: opJump,
gasCost: constGasFunc(GasMidStep),
validateStack: makeStackFunc(1, 0),
jumps: true,
valid: true,
},
JUMPI: {
execute: opJumpi,
gasCost: constGasFunc(GasSlowStep),
validateStack: makeStackFunc(2, 0),
jumps: true,
valid: true,
},
PC: {
execute: opPc,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
MSIZE: {
execute: opMsize,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
GAS: {
execute: opGas,
gasCost: constGasFunc(GasQuickStep),
validateStack: makeStackFunc(0, 1),
valid: true,
},
JUMPDEST: {
execute: opJumpdest,
gasCost: constGasFunc(params.JumpdestGas),
validateStack: makeStackFunc(0, 0),
valid: true,
},
PUSH1: {
execute: makePush(1, 1),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH2: {
execute: makePush(2, 2),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH3: {
execute: makePush(3, 3),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH4: {
execute: makePush(4, 4),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH5: {
execute: makePush(5, 5),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH6: {
execute: makePush(6, 6),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH7: {
execute: makePush(7, 7),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH8: {
execute: makePush(8, 8),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH9: {
execute: makePush(9, 9),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH10: {
execute: makePush(10, 10),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH11: {
execute: makePush(11, 11),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH12: {
execute: makePush(12, 12),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH13: {
execute: makePush(13, 13),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH14: {
execute: makePush(14, 14),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH15: {
execute: makePush(15, 15),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH16: {
execute: makePush(16, 16),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH17: {
execute: makePush(17, 17),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH18: {
execute: makePush(18, 18),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH19: {
execute: makePush(19, 19),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH20: {
execute: makePush(20, 20),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH21: {
execute: makePush(21, 21),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH22: {
execute: makePush(22, 22),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH23: {
execute: makePush(23, 23),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH24: {
execute: makePush(24, 24),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH25: {
execute: makePush(25, 25),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH26: {
execute: makePush(26, 26),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH27: {
execute: makePush(27, 27),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH28: {
execute: makePush(28, 28),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH29: {
execute: makePush(29, 29),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH30: {
execute: makePush(30, 30),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH31: {
execute: makePush(31, 31),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
PUSH32: {
execute: makePush(32, 32),
gasCost: gasPush,
validateStack: makeStackFunc(0, 1),
valid: true,
},
DUP1: {
execute: makeDup(1),
gasCost: gasDup,
validateStack: makeDupStackFunc(1),
valid: true,
},
DUP2: {
execute: makeDup(2),
gasCost: gasDup,
validateStack: makeDupStackFunc(2),
valid: true,
},
DUP3: {
execute: makeDup(3),
gasCost: gasDup,
validateStack: makeDupStackFunc(3),
valid: true,
},
DUP4: {
execute: makeDup(4),
gasCost: gasDup,
validateStack: makeDupStackFunc(4),
valid: true,
},
DUP5: {
execute: makeDup(5),
gasCost: gasDup,
validateStack: makeDupStackFunc(5),
valid: true,
},
DUP6: {
execute: makeDup(6),
gasCost: gasDup,
validateStack: makeDupStackFunc(6),
valid: true,
},
DUP7: {
execute: makeDup(7),
gasCost: gasDup,
validateStack: makeDupStackFunc(7),
valid: true,
},
DUP8: {
execute: makeDup(8),
gasCost: gasDup,
validateStack: makeDupStackFunc(8),
valid: true,
},
DUP9: {
execute: makeDup(9),
gasCost: gasDup,
validateStack: makeDupStackFunc(9),
valid: true,
},
DUP10: {
execute: makeDup(10),
gasCost: gasDup,
validateStack: makeDupStackFunc(10),
valid: true,
},
DUP11: {
execute: makeDup(11),
gasCost: gasDup,
validateStack: makeDupStackFunc(11),
valid: true,
},
DUP12: {
execute: makeDup(12),
gasCost: gasDup,
validateStack: makeDupStackFunc(12),
valid: true,
},
DUP13: {
execute: makeDup(13),
gasCost: gasDup,
validateStack: makeDupStackFunc(13),
valid: true,
},
DUP14: {
execute: makeDup(14),
gasCost: gasDup,
validateStack: makeDupStackFunc(14),
valid: true,
},
DUP15: {
execute: makeDup(15),
gasCost: gasDup,
validateStack: makeDupStackFunc(15),
valid: true,
},
DUP16: {
execute: makeDup(16),
gasCost: gasDup,
validateStack: makeDupStackFunc(16),
valid: true,
},
SWAP1: {
execute: makeSwap(1),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(2),
valid: true,
},
SWAP2: {
execute: makeSwap(2),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(3),
valid: true,
},
SWAP3: {
execute: makeSwap(3),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(4),
valid: true,
},
SWAP4: {
execute: makeSwap(4),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(5),
valid: true,
},
SWAP5: {
execute: makeSwap(5),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(6),
valid: true,
},
SWAP6: {
execute: makeSwap(6),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(7),
valid: true,
},
SWAP7: {
execute: makeSwap(7),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(8),
valid: true,
},
SWAP8: {
execute: makeSwap(8),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(9),
valid: true,
},
SWAP9: {
execute: makeSwap(9),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(10),
valid: true,
},
SWAP10: {
execute: makeSwap(10),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(11),
valid: true,
},
SWAP11: {
execute: makeSwap(11),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(12),
valid: true,
},
SWAP12: {
execute: makeSwap(12),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(13),
valid: true,
},
SWAP13: {
execute: makeSwap(13),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(14),
valid: true,
},
SWAP14: {
execute: makeSwap(14),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(15),
valid: true,
},
SWAP15: {
execute: makeSwap(15),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(16),
valid: true,
},
SWAP16: {
execute: makeSwap(16),
gasCost: gasSwap,
validateStack: makeSwapStackFunc(17),
valid: true,
},
LOG0: {
execute: makeLog(0),
gasCost: makeGasLog(0),
validateStack: makeStackFunc(2, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG1: {
execute: makeLog(1),
gasCost: makeGasLog(1),
validateStack: makeStackFunc(3, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG2: {
execute: makeLog(2),
gasCost: makeGasLog(2),
validateStack: makeStackFunc(4, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG3: {
execute: makeLog(3),
gasCost: makeGasLog(3),
validateStack: makeStackFunc(5, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG4: {
execute: makeLog(4),
gasCost: makeGasLog(4),
validateStack: makeStackFunc(6, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
CREATE: {
execute: opCreate,
gasCost: gasCreate,
validateStack: makeStackFunc(3, 1),
memorySize: memoryCreate,
valid: true,
writes: true,
returns: true,
},
CALL: {
execute: opCall,
gasCost: gasCall,
validateStack: makeStackFunc(7, 1),
memorySize: memoryCall,
valid: true,
returns: true,
},
CALLCODE: {
execute: opCallCode,
gasCost: gasCallCode,
validateStack: makeStackFunc(7, 1),
memorySize: memoryCall,
valid: true,
returns: true,
},
RETURN: {
execute: opReturn,
gasCost: gasReturn,
validateStack: makeStackFunc(2, 0),
memorySize: memoryReturn,
halts: true,
valid: true,
},
SELFDESTRUCT: {
execute: opSuicide,
gasCost: gasSuicide,
validateStack: makeStackFunc(1, 0),
halts: true,
valid: true,
writes: true,
},
}
}