prePO contest - TerrierLover's results

No need to wrap with parenthesis

Target codebase

_valueBefore variable is wrapped by parenthesis but this is not needed.

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/Collateral.sol#L89

_shares = (_amountToDeposit * totalSupply()) / (_valueBefore);

Proposed change

_shares = (_amountToDeposit * totalSupply()) / _valueBefore;

unchecked direction can be used at mintLongShortTokens function in PrePOMarket.sol

Target codebase

mintLongShortTokens function in PrePOMarket.sol can use unchecked directory.

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/PrePOMarket.sol#L122

require(_amount > _fee, "Minting amount too small");
_collateral.transferFrom(msg.sender, _treasury, _fee);
_amount -= _fee;

It is obvious that _amount - _fee will not be underflown since it has require(_amount > _fee, ...). Hence, can use unchecked directory,

Proposed change

require(_amount > _fee, "Minting amount too small");
_collateral.transferFrom(msg.sender, _treasury, _fee);
unchecked {
    _amount -= _fee;
}

Gas changes with the proposed changes

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---

unchecked direction can be used at redeem function in PrePOMarket.sol

Target codebase

redeem function in PrePOMarket.sol can use unchecked directory.

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/PrePOMarket.sol#L169

require(_collateralOwed > _fee, "Redemption amount too small");
_collateral.transfer(_treasury, _fee);
_collateralOwed -= _fee;

It is obvious that _collateralOwed - _fee will not be underflown since it has require(_collateralOwed > _fee, ...). Hence, can use unchecked directory,

Proposed change

require(_collateralOwed > _fee, "Redemption amount too small");
_collateral.transfer(_treasury, _fee);
unchecked {
    _collateralOwed -= _fee;
}

Gas changes with the proposed changes

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Deployments - average gas change

---

Target codebase

Proposed change

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change

---

Unchecked can be used at deposit function in Collateral.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/Collateral.sol#L73

require(_amountToDeposit > _fee, "Deposit amount too small");
_baseToken.safeTransfer(_treasury, _fee);
_amountToDeposit -= _fee;

_amountToDeposit - _fee will not be underflown since require(_amountToDeposit > _fee, ...).

Proposed change

require(_amountToDeposit > _fee, "Deposit amount too small");
_baseToken.safeTransfer(_treasury, _fee);
unchecked {
    _amountToDeposit -= _fee;
}

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change

---

uint256 _shares does not need to be initialized with 0 at deposit function in Collateral.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/Collateral.sol#L81

uint256 _shares = 0;

Proposed change

uint256 _shares;

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change

---

unchecked can be used at withdraw function at Collateral.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/Collateral.sol#L171

require(_amountWithdrawn > _fee, "Withdrawal amount too small");
_baseToken.safeTransfer(_treasury, _fee);
_amountWithdrawn -= _fee;

It is obvious that _amountWithdrawn - _fee will not be underflown since it has require(_amountWithdrawn > _fee, ...).

Proposed change

require(_amountWithdrawn > _fee, "Withdrawal amount too small");
_baseToken.safeTransfer(_treasury, _fee);
unchecked {
    _amountWithdrawn -= _fee;
}

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change

---

Unchecked can be used at recordDeposit function in CollateralDepositRecord.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/CollateralDepositRecord.sol#L37-L38

require(
    _amount + _globalDepositAmount <= _globalDepositCap,
    "Global deposit cap exceeded"
);
require(
    _amount + _accountToNetDeposit[_sender] <= _accountDepositCap,
    "Account deposit cap exceeded"
);
_globalDepositAmount += _amount;
_accountToNetDeposit[_sender] += _amount;

Both _globalDepositAmount + _amount and _accountToNetDeposit[_sender] + _amount will not be overflown because it checks _amount + _globalDepositAmount <= _globalDepositCap and _amount + _accountToNetDeposit[_sender] <= _accountDepositCap before.

Proposed change

require(
    _amount + _globalDepositAmount <= _globalDepositCap,
    "Global deposit cap exceeded"
);
require(
    _amount + _accountToNetDeposit[_sender] <= _accountDepositCap,
    "Account deposit cap exceeded"
);
unchecked {
    _globalDepositAmount += _amount;
    _accountToNetDeposit[_sender] += _amount;
}

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change

---

Unchecked can be used at recordWithdrawal function in CollateralDepositRecord.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/CollateralDepositRecord.sol#L47 https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/CollateralDepositRecord.sol#L52

if (_globalDepositAmount > _amount) {
    _globalDepositAmount -= _amount;
} else {
    _globalDepositAmount = 0;
}
if (_accountToNetDeposit[_sender] > _amount) {
    _accountToNetDeposit[_sender] -= _amount;
} else {
    _accountToNetDeposit[_sender] = 0;
}

_globalDepositAmount - _amount and _accountToNetDeposit[_sender] - _amount will not be underflown since they are wrapped by the if statement _globalDepositAmount > _amount or _accountToNetDeposit[_sender] > _amount.

Proposed change

if (_globalDepositAmount > _amount) {
    unchecked {
        _globalDepositAmount -= _amount;
    }
} else {
    _globalDepositAmount = 0;
}
if (_accountToNetDeposit[_sender] > _amount) {
    unchecked {
        _accountToNetDeposit[_sender] -= _amount;
    }
} else {
    _accountToNetDeposit[_sender] = 0;
}

Gas changes with the proposed changes

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Unchecked can be used at allowAccounts function in AccountAccessController.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/AccountAccessController.sol#L44

for (uint256 _i = 0; _i < _accounts.length; _i++) {
    _allowedAccounts[_allowedAccountsIndex][_accounts[_i]] = true;
    emit AccountAllowed(_accounts[_i]);
}

Proposed change

for (uint256 _i = 0; _i < _accounts.length; ) {
    _allowedAccounts[_allowedAccountsIndex][_accounts[_i]] = true;
    emit AccountAllowed(_accounts[_i]);
    unchecked {
        _i++;
    }
}

Gas changes with the proposed changes

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Deployments - average gas change

---

Unchecked can be used at blockAccounts function in AccountAccessController.sol

Target codebase

https://github.com/code-423n4/2022-03-prepo/blob/main/contracts/core/AccountAccessController.sol#L55-L58

for (uint256 _i = 0; _i < _accounts.length; _i++) {
    _blockedAccounts[_blockedAccountsIndex][_accounts[_i]] = true;
    emit AccountBlocked(_accounts[_i]);
}

Proposed change

for (uint256 _i = 0; _i < _accounts.length; ) {
    _blockedAccounts[_blockedAccountsIndex][_accounts[_i]] = true;
    emit AccountBlocked(_accounts[_i]);
    unchecked {
        _i++;
    }
}

Gas changes with the proposed changes

Methods - average gas change

Deployments - average gas change