PoolTogether - 0xhacksmithh's results

[Gas-01] No need to check _shares == 0 & _assets == 0 inside _depositAndMint() and _burnAndWithdraw()

As we hcan see _shares = previewDeposit(_assets); and _assets = previewMint(_shares); where they are 1:1 as per code comment

so basically if _shares != 0 so that also same for _assets

So check for only one of them will sufficient. file: PrizeVault.sol

function _depositAndMint(address _caller, address _receiver, uint256 _assets, uint256 _shares) internal {
        if (_shares == 0) revert MintZeroShares();
        if (_assets == 0) revert DepositZeroAssets();

function _burnAndWithdraw(
        address _caller,
        address _receiver,
        address _owner,
        uint256 _shares,
        uint256 _assets
    ) internal {
        if (_assets == 0) revert WithdrawZeroAssets(); // @audit gas
        if (_shares == 0) revert BurnZeroShares();
        if (_caller != _owner) {
            _spendAllowance(_owner, _caller, _shares);

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L843-L845

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L894-L895

[Gas-02] some state variable could be immutable

As variable only set once. file: Claimable.sol

-   address public claimer;

+   address public immutable claimer;

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/abstract/Claimable.sol#L27

[Gas-03] Instaed of reading state variable multiple times, that state variable could be cached in memory

claimer an cached in memory

file: Claimable.sol

   modifier onlyClaimer() {
+       address _claimer = claimer;
-       if (msg.sender != claimer) revert CallerNotClaimer(msg.sender, claimer);

+       if (msg.sender != _claimer) revert CallerNotClaimer(msg.sender, _claimer); 
        _;
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/abstract/Claimable.sol#L53

liquidationPair and yieldFeeRecipient could be cached in memory

file: PrizeVault.sol

    modifier onlyLiquidationPair() {
        if (msg.sender != liquidationPair) { // @audit dual state read
            revert CallerNotLP(msg.sender, liquidationPair);
        }
        _;
    }

    /// @notice Requires the caller to be the yield fee recipient.
    modifier onlyYieldFeeRecipient() {
        if (msg.sender != yieldFeeRecipient) { // @audit dual state read
            revert CallerNotYieldFeeRecipient(msg.sender, yieldFeeRecipient);
        }
        _;
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L260-L273

[Gas-04] some mapping results could be cached in memory rather than recalling those again and again

_hooks[_winner] could be stored in memory

file: Claimable.sol

if (_hooks[_winner].useBeforeClaimPrize) { // @audit _hooks[_winner]
            recipient = _hooks[_winner].implementation.beforeClaimPrize{ gas: HOOK_GAS }(
                _winner,
                _tier,
                _prizeIndex,
                _reward,
                _rewardRecipient
            );
        } else {
            recipient = _winner;
        }

        if (recipient == address(0)) revert ClaimRecipientZeroAddress();

        uint256 prizeTotal = prizePool.claimPrize(
            _winner,
            _tier,
            _prizeIndex,
            recipient,
            _reward,
            _rewardRecipient
        );

        if (_hooks[_winner].useAfterClaimPrize) {
            _hooks[_winner].implementation.afterClaimPrize{ gas: HOOK_GAS }(
                _winner,
                _tier,
                _prizeIndex,
                prizeTotal,
                recipient
            );

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/abstract/Claimable.sol#L85-L115

[Gas-05] internal function only once used could be inlined

_setClaimer() is a inernal function which only called once in constructor, and never sed further could be inlined file: Claimable.sol

    function _setClaimer(address _claimer) internal { // @audit inlined
        if (_claimer == address(0)) revert ClaimerZeroAddress();
        claimer = _claimer;
        emit ClaimerSet(_claimer);
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/abstract/Claimable.sol#L128-L132

[Gas-06] Arithmatic operation could be unchecked

file: PrizeVaultFactory.sol

        PrizeVault _vault = new PrizeVault{
            salt: keccak256(abi.encode(msg.sender, deployerNonces[msg.sender]++)) 
        }(

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVaultFactory.sol#L103

[Gas-07] Instaed of using state variable in revert, first local cache memory varible could used

file: PrizeVault.sol

    modifier onlyLiquidationPair() {
        if (msg.sender != liquidationPair) { // @audit dual state read
            revert CallerNotLP(msg.sender, liquidationPair);
        }
        _;
    }

    /// @notice Requires the caller to be the yield fee recipient.
    modifier onlyYieldFeeRecipient() {
        if (msg.sender != yieldFeeRecipient) { // @audit dual state read
            revert CallerNotYieldFeeRecipient(msg.sender, yieldFeeRecipient);
        }
        _;
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L260-L273

[Gas-08]

file: PrizeVault.sol

yieldVault could be cached in memory

function totalAssets() public view returns (uint256) { // @audit yieldVault
        return yieldVault.convertToAssets(yieldVault.balanceOf(address(this))) + _asset.balanceOf(address(this));
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L336-L338

prizePool could cached in memory rather than recalling it again and again

) external onlyLiquidationPair {
        address _prizeToken = address(prizePool.prizeToken()); // @audit prizePool
        if (_tokenIn != _prizeToken) {
            revert LiquidationTokenInNotPrizeToken(_tokenIn, _prizeToken);
        }

        prizePool.contributePrizeTokens(address(this), _amountIn);
    }

https://github.com/code-423n4/2024-03-pooltogether/blob/main/pt-v5-vault/src/PrizeVault.sol#L708