Trader Joe contest - Rhynorater's results

Handle

Rhynorater

Vulnerability details

It is possible to optimize the gas efficiency of this code by modifying the following line: https://github.com/code-423n4/2022-01-trader-joe/blob/a1579f6453bc4bf9fb0db9c627beaa41135438ed/contracts/LaunchEvent.sol#L361

        require(
            user.balance >= _amount,
            "LaunchEvent: withdrawn amount exceeds balance"
        );
        user.balance -= _amount;

to

        require(
            user.balance >= _amount,
            "LaunchEvent: withdrawn amount exceeds balance"
        );
        unchecked{
            user.balance -= _amount;
        }

This is due to the fact Solidity 0.8.0+ has built-in overflow/underflow math check and since user.balance will never underflow per the above statement checking that user.balance is greater than _amount, this check is unnecessary. Adding the unchecked directive will save on gas.

Handle

Rhynorater

Vulnerability details

The withdrawAVAX function defined on line #349 of LaunchEvent.sol is defined as a public function. However, since the contract in question does not call the withdrawAVAX, it should be defined as external to save on gas.

References: https://github.com/crytic/slither/wiki/Detector-Documentation#public-function-that-could-be-declared-external