Increments can be unchecked

[codehawks-bot]

Increments can be unchecked

Severity

Gas Optimization

Relevant GitHub Links

ethereum/solidity#10695

Summary

In Solidity 0.8+, there’s a default overflow check on unsigned integers. It’s possible to uncheck this in for-loops and save some gas at each iteration, but at the cost of some code readability, as this uncheck cannot be made inline.

Vulnerability Details

https://github.com/Cyfrin/2023-07-beedle/blob/main/src/Lender.sol

Instances included:

Lender.borrow() #232      for (uint256 i = 0; i < borrows.length; i++) {

Lender.repay() #292      for (uint256 i = 0; i < loanIds.length; i++) {

Lender.giveLoan() #355      for (uint256 i = 0; i < loanIds.length; i++) {

Lender.startAuction() #437      for (uint256 i = 0; i < loanIds.length; i++) {

Lender.seizeLoan() #548      for (uint256 i = 0; i < loanIds.length; i++) {

Lender.refinance() #591      for (uint256 i = 0; i < refinances.length; i++) {

Tools Used

Manual

Recommendations

The code would go from:

for (uint256 i = 0; i < [].length; i++) {  
 // ...  
}  

to

for (uint256 i = 0; i < [].length;) {  
 // ...  
 unchecked { i++; }  
}