Upgrading the solc compiler to >=0.8 may save gas

[code423n4]

Handle

0xRajeev

Vulnerability details

Impact

The latest version of solc compiler is 8.6. Most contracts (except IdleYieldSource) allow use of solc version >=0.6.0 <0.7.0, which is fairly dated. This may be a carry-over from previous versions of project to minimize porting code to handle breaking changes across solc 0.7.0 or 0.8.0.

Impact: Upgrading the solc compiler to 0.8 will give the latest compiler benefits including bug fixes, security enhancements and overall optimizations especially the in-built overflow/underflow checks which may give gas savings by avoiding expensive SafeMath.

Proof of Concept

https://github.com/code-423n4/2021-06-pooltogether/blob/85f8d044e7e46b7a3c64465dcd5dffa9d70e4a3e/contracts/PrizePool.sol#L3

https://github.com/code-423n4/2021-06-pooltogether/blob/85f8d044e7e46b7a3c64465dcd5dffa9d70e4a3e/contracts/Ticket.sol#L3

https://github.com/code-423n4/2021-06-pooltogether/blob/85f8d044e7e46b7a3c64465dcd5dffa9d70e4a3e/contracts/YieldSourcePrizePool.sol#L3

https://github.com/code-423n4/2021-06-pooltogether/blob/85f8d044e7e46b7a3c64465dcd5dffa9d70e4a3e/contracts/yield-source/IdleYieldSource.sol#L3

Tools Used

Manual Analysis

Recommended Mitigation Steps

Consider porting over code to solc >= 0.8.0 for bug fixes, security enhancements and overall optimizations for gas savings.

[asselstine]

We're looking for concrete optimizations, not suggestions to upgrade the version of solc we use.

[dmvt]

You can take or leave the suggestion, but he is correct here that upgrading to 0.8 would save some gas.