Submission Details
Severity:
Gas Optimizations
| Issue | Instances | |
|---|---|---|
| GAS-1 | Cache array length outside of loop | 2 |
| GAS-2 | For Operations that will not overflow, you could use unchecked | 67 |
| GAS-3 | Don't initialize variables with default value | 2 |
| GAS-4 | Functions guaranteed to revert when called by normal users can be marked payable |
2 |
| GAS-5 | ++i costs less gas than i++, especially when it's used in for-loops (--i/i-- too) |
2 |
[GAS-1] Cache array length outside of loop
If not cached, the solidity compiler will always read the length of the array during each iteration. That is, if it is a storage array, this is an extra sload operation (100 additional extra gas for each iteration except for the first) and if it is a memory array, this is an extra mload operation (3 additional gas for each iteration except for the first).
Instances (2):
File: DSCEngine.sol
118: for (uint256 i = 0; i < tokenAddresses.length; i++) {
353: for (uint256 i = 0; i < s_collateralTokens.length; i++) {
[GAS-2] For Operations that will not overflow, you could use unchecked
Instances (67):
File: DSCEngine.sol
26: import {DecentralizedStableCoin} from "./DecentralizedStableCoin.sol";
27: import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
27: import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
27: import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
28: import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
28: import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
28: import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
28: import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
29: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
29: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
29: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
29: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
29: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
30: import {OracleLib} from "./libraries/OracleLib.sol";
30: import {OracleLib} from "./libraries/OracleLib.sol";
72: uint256 private constant LIQUIDATION_THRESHOLD = 50; // 200% overcollateralized
72: uint256 private constant LIQUIDATION_THRESHOLD = 50; // 200% overcollateralized
75: uint256 private constant LIQUIDATION_BONUS = 10; // this means a 10% bonus
75: uint256 private constant LIQUIDATION_BONUS = 10; // this means a 10% bonus
77: mapping(address token => address priceFeed) private s_priceFeeds; // tokenToPriceFeed
77: mapping(address token => address priceFeed) private s_priceFeeds; // tokenToPriceFeed
118: for (uint256 i = 0; i < tokenAddresses.length; i++) {
118: for (uint256 i = 0; i < tokenAddresses.length; i++) {
155: s_collateralDeposited[msg.sender][tokenCollateralAddress] += amountCollateral;
198: s_DSCMinted[msg.sender] += amountDscToMint;
214: _revertIfHealthFactorIsBroken(msg.sender); // I don't think this would ever hit...
214: _revertIfHealthFactorIsBroken(msg.sender); // I don't think this would ever hit...
251: uint256 bonusCollateral = (tokenAmountFromDebtCovered * LIQUIDATION_BONUS) / LIQUIDATION_PRECISION;
251: uint256 bonusCollateral = (tokenAmountFromDebtCovered * LIQUIDATION_BONUS) / LIQUIDATION_PRECISION;
252: uint256 totalCollateralToRedeem = tokenAmountFromDebtCovered + bonusCollateral;
273: s_DSCMinted[onBehalfOf] -= amountDscToBurn;
285: s_collateralDeposited[from][tokenCollateralAddress] -= amountCollateral;
330: uint256 collateralAdjustedForThreshold = (collateralValueInUsd * LIQUIDATION_THRESHOLD) / LIQUIDATION_PRECISION;
330: uint256 collateralAdjustedForThreshold = (collateralValueInUsd * LIQUIDATION_THRESHOLD) / LIQUIDATION_PRECISION;
331: return (collateralAdjustedForThreshold * 1e18) / totalDscMinted;
331: return (collateralAdjustedForThreshold * 1e18) / totalDscMinted;
347: return (usdAmountInWei * PRECISION) / (uint256(price) * ADDITIONAL_FEED_PRECISION);
347: return (usdAmountInWei * PRECISION) / (uint256(price) * ADDITIONAL_FEED_PRECISION);
347: return (usdAmountInWei * PRECISION) / (uint256(price) * ADDITIONAL_FEED_PRECISION);
353: for (uint256 i = 0; i < s_collateralTokens.length; i++) {
353: for (uint256 i = 0; i < s_collateralTokens.length; i++) {
356: totalCollateralValueInUsd += getUsdValue(token, amount);
366: return ((uint256(price) * ADDITIONAL_FEED_PRECISION) * amount) / PRECISION;
366: return ((uint256(price) * ADDITIONAL_FEED_PRECISION) * amount) / PRECISION;
366: return ((uint256(price) * ADDITIONAL_FEED_PRECISION) * amount) / PRECISION;
File: DecentralizedStableCoin.sol
26: import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
26: import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
26: import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
26: import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
26: import {ERC20Burnable, ERC20} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
27: import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
27: import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
27: import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
File: libraries/OracleLib.sol
5: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
5: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
5: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
5: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
5: import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
19: uint256 private constant TIMEOUT = 3 hours; // 3 * 60 * 60 = 10800 seconds
19: uint256 private constant TIMEOUT = 3 hours; // 3 * 60 * 60 = 10800 seconds
19: uint256 private constant TIMEOUT = 3 hours; // 3 * 60 * 60 = 10800 seconds
19: uint256 private constant TIMEOUT = 3 hours; // 3 * 60 * 60 = 10800 seconds
29: uint256 secondsSince = block.timestamp - updatedAt;
35: function getTimeout(AggregatorV3Interface /* chainlinkFeed */ ) public pure returns (uint256) {
35: function getTimeout(AggregatorV3Interface /* chainlinkFeed */ ) public pure returns (uint256) {
35: function getTimeout(AggregatorV3Interface /* chainlinkFeed */ ) public pure returns (uint256) {
35: function getTimeout(AggregatorV3Interface /* chainlinkFeed */ ) public pure returns (uint256) {
[GAS-3] Don't initialize variables with default value
Instances (2):
File: DSCEngine.sol
118: for (uint256 i = 0; i < tokenAddresses.length; i++) {
353: for (uint256 i = 0; i < s_collateralTokens.length; i++) {
[GAS-4] Functions guaranteed to revert when called by normal users can be marked payable
If a function modifier such as onlyOwner is used, the function will revert if a normal user tries to pay the function. Marking the function as payable will lower the gas cost for legitimate callers because the compiler will not include checks for whether a payment was provided.
Instances (2):
File: DecentralizedStableCoin.sol
46: function burn(uint256 _amount) public override onlyOwner {
57: function mint(address _to, uint256 _amount) external onlyOwner returns (bool) {
[GAS-5] ++i costs less gas than i++, especially when it's used in for-loops (--i/i-- too)
Saves 5 gas per loop
Instances (2):
File: DSCEngine.sol
118: for (uint256 i = 0; i < tokenAddresses.length; i++) {
353: for (uint256 i = 0; i < s_collateralTokens.length; i++) {
Low Issues
| Issue | Instances | |
|---|---|---|
| L-1 | Empty Function Body - Consider commenting why | 1 |
| L-2 | Unsafe ERC20 operation(s) | 3 |
[L-1] Empty Function Body - Consider commenting why
Instances (1):
File: DecentralizedStableCoin.sol
44: constructor() ERC20("DecentralizedStableCoin", "DSC") {}
[L-2] Unsafe ERC20 operation(s)
Instances (3):
File: DSCEngine.sol
157: bool success = IERC20(tokenCollateralAddress).transferFrom(msg.sender, address(this), amountCollateral);
274: bool success = i_dsc.transferFrom(dscFrom, address(this), amountDscToBurn);
287: bool success = IERC20(tokenCollateralAddress).transfer(to, amountCollateral);
Medium Issues
| Issue | Instances | |
|---|---|---|
| M-1 | Centralization Risk for trusted owners | 3 |
[M-1] Centralization Risk for trusted owners
Impact:
Contracts have owners with privileged rights to perform admin tasks and need to be trusted to not perform malicious updates or drain funds.
Instances (3):
File: DecentralizedStableCoin.sol
39: contract DecentralizedStableCoin is ERC20Burnable, Ownable {
46: function burn(uint256 _amount) public override onlyOwner {
57: function mint(address _to, uint256 _amount) external onlyOwner returns (bool) {
Prize pool breakdown
Total prize
15,000 USDC
nSLOC
23664 USDC / LOC
14,000 USDC
1,000 USDC
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