Solidity Highlighting Test
pragma solidity ^0.8.17;
contract Variables {
// State variables are stored on the blockchain.
string public text = "Hello";
uint public num = 123;
function doSomething() public {
// Local variables are not saved to the blockchain.
uint i = 456;
// Here are some global variables
uint timestamp = block.timestamp; // Current block timestamp
address sender = msg.sender; // address of the caller
}
}
pragma solidity ^0.8.17;
contract MultiDelegatecall {
error DelegatecallFailed();
function multiDelegatecall(
bytes[] memory data
) external payable returns (bytes[] memory results) {
results = new bytes[](data.length);
for (uint i; i < data.length; i++) {
(bool ok, bytes memory res) = address(this).delegatecall(data[i]);
if (!ok) {
revert DelegatecallFailed();
}
results[i] = res;
}
}
}
// Why use multi delegatecall? Why not multi call?
// alice -> multi call --- call ---> test (msg.sender = multi call)
// alice -> test --- delegatecall ---> test (msg.sender = alice)
contract TestMultiDelegatecall is MultiDelegatecall {
event Log(address caller, string func, uint i);
function func1(uint x, uint y) external {
// msg.sender = alice
emit Log(msg.sender, "func1", x + y);
}
function func2() external returns (uint) {
// msg.sender = alice
emit Log(msg.sender, "func2", 2);
return 111;
}
mapping(address => uint) public balanceOf;
// WARNING: unsafe code when used in combination with multi-delegatecall
// user can mint multiple times for the price of msg.value
function mint() external payable {
balanceOf[msg.sender] += msg.value;
}
}
contract Helper {
function getFunc1Data(uint x, uint y) external pure returns (bytes memory) {
return abi.encodeWithSelector(TestMultiDelegatecall.func1.selector, x, y);
}
function getFunc2Data() external pure returns (bytes memory) {
return abi.encodeWithSelector(TestMultiDelegatecall.func2.selector);
}
function getMintData() external pure returns (bytes memory) {
return abi.encodeWithSelector(TestMultiDelegatecall.mint.selector);
}
}
Updated over 2 years ago