Platform: Code4rena
Start Date: 15/06/2022
Pot Size: $30,000 USDC
Total HM: 5
Participants: 55
Period: 3 days
Judge: Jack the Pug
Id: 138
League: ETH
Rank: 34/55
Findings: 2
Award: $81.01
🌟 Selected for report: 0
🚀 Solo Findings: 0
🌟 Selected for report: IllIllI
Also found by: 0v3rf10w, 0x1f8b, 0xDjango, 0xFar5eer, 0xNazgul, 0xNineDec, 242, Chom, Czar102, Funen, GimelSec, Meera, Picodes, Sm4rty, Tadashi, TerrierLover, Waze, _Adam, a12jmx, asutorufos, codexploder, cryptphi, defsec, gzeon, hyh, joestakey, minhquanym, oyc_109, reassor, robee, saian, sorrynotsorry, unforgiven, zzzitron
50.8486 USDC - $50.85
Recommend removing open todos before deploying. MyStrategy.sol#L284 MyStrategy.sol#L422
Adding indexed fields to events will help with off chain monitoring. MyStrategy.sol#L51
#0 - GalloDaSballo
2022-06-19T02:02:53Z
ACk
30.1619 USDC - $30.16
When incrementing i in for loops there is no chance of overflow so unchecked can be used to save gas. I ran a simple test in remix and found deployment savings of 31,653 gas and on each function call saved ~141 gas per iteration.
contract Test { function loopTest() external { for (uint256 i; i < 1; ++i) { Deployment Cost: 125,637, Cost on function call: 24,601 vs for (uint256 i; i < 1; ) { // for loop body unchecked { ++i } Deployment Cost: 93,984, Cost on function call: 24,460 } } }
In for loops pre increments can also be used to save a small amount of gas per iteraition. I ran a test in remix using a for loop and found the deployment savings of 497 gas and ~5 gas per iteration.
contract Test { function loopTest() external { for (uint256 i; i < 1; i++) { (Deployment cost: 118,408, Cost on function call: 24,532) vs for (uint256 i; i < 1; ++i) { (Deployment cost: 117,911, Cost on function call: 24,527) } } }
Instances where unchecked and pre Increments can be implemented in for loops: MyStrategy.sol#L118 MyStrategy.sol#L153 - is already pre increment MyStrategy.sol#L300 MyStrategy.sol#L317
Keeping revert strings <= 32 bytes in length will save gas. I ran a test in remix and found the savings for a single short revert string vs long string to be 9,377 gas in deployment cost and 18 gas on function call.
contract Test { uint256 a; function check() external { require(a != 0, "short error message"); (Deployment cost: 114,799, Cost on function call: 23,392) vs require(a != 0, "A longer Error Message over 32 bytes in length"); (Deployment cost: 124,176, Cost on function call: 23,410) } }
I recommend shortenning the following revert strings to <= 32 bytes in length: MyStrategy.sol#L186
If optimising for running costs over deployment costs you can seperate && in require functions into 2 parts. I ran a basic test in remix and it cost an extra 234 gas to deploy but will save ~9 gas everytime the require function is called.
contract Test { uint256 a = 0; uint256 b = 1; function test() external { require(a == 0 && b > a) (Deployment cost: 123,291, Cost on function call: 29,371) vs require(a == 0); require(b > a); (Deployment cost: 123,525, Cost on function call: 29,362) } }
#0 - GalloDaSballo
2022-06-19T02:03:25Z
Ack