solidity delegatecall

pragma solidity ^0.8.20;

contract ContractCall {

	address public owner;
	uint256 public num;
	address public lib;
	
	constructor() {
		owner = msg.sender;
	}
	function setLibAddress(address _Lib) public {
		lib = _Lib;
	}
	function nowOwner() public view returns (address) {
		return owner;
	}
	function callDelegate(uint256 _num) public payable returns (bool)
	{		
		(bool success, ) = lib.delegatecall(abi.encodeWithSignature("changeOwner(uint256)", _num));
		return success;
	}
}

pragma solidity ^0.8.20;

contract ChangeOwner {

    address public owner;
    uint256 public num;

    function changeOwner(uint256 _num) public {
        owner = msg.sender;
        num = _num;
    }
}

각각 deploy 후 setLibAddress에 ChangeOwner 컨트랙트의 주소를 넣고 callDelegate를 호출하면 num 및 owner가 변경된다.

주의할 점은 변수의 순서가 일치하여야 한다.

만약 아래와 같이 코딩했다면, ContractCall의 owner에는 num, num에는 owner가 저장된다.

contract ContractCall {
	address public owner;
	uint256 public num;
	address public lib;
    
contract ChangeOwner {
	uint256 public num;
	address public owner;

remix로 확인 결과