Platform: Code4rena
Start Date: 12/08/2022
Pot Size: $35,000 USDC
Total HM: 10
Participants: 126
Period: 3 days
Judge: Justin Goro
Total Solo HM: 3
Id: 154
League: ETH
Rank: 107/126
Findings: 1
Award: $15.07
🌟 Selected for report: 0
🚀 Solo Findings: 0
🌟 Selected for report: IllIllI
Also found by: 0x040, 0x1f8b, 0xDjango, 0xHarry, 0xLovesleep, 0xNazgul, 0xNineDec, 0xSmartContract, 0xackermann, 0xbepresent, 2997ms, Amithuddar, Aymen0909, Bnke0x0, CRYP70, CertoraInc, Chom, CodingNameKiki, Deivitto, Dravee, ElKu, Fitraldys, Funen, GalloDaSballo, JC, JohnSmith, Junnon, LeoS, Metatron, MiloTruck, Noah3o6, NoamYakov, PaludoX0, RedOneN, Respx, ReyAdmirado, Rohan16, Rolezn, Ruhum, Sm4rty, SooYa, SpaceCake, TomJ, Tomio, Waze, Yiko, __141345__, a12jmx, ajtra, ak1, apostle0x01, asutorufos, bobirichman, brgltd, bulej93, c3phas, cRat1st0s, carlitox477, chrisdior4, csanuragjain, d3e4, defsec, delfin454000, djxploit, durianSausage, ellahi, erictee, fatherOfBlocks, gerdusx, gogo, ignacio, jag, ladboy233, m_Rassska, medikko, mics, natzuu, newfork01, oyc_109, paribus, pfapostol, rbserver, reassor, ret2basic, robee, rokinot, rvierdiiev, sach1r0, saian, sashik_eth, sikorico, simon135
15.0735 USDC - $15.07
calldata should be used instead of memory for function parameters saves gas if the function argument is only read.
https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L224 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L225 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L597 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L685 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L825
Uninitialized variables are assigned with the types default value.
Explicitly initializing a variable with it's default value costs unnecessary gas.
Suggest not initializing the for loop counter to 0.
An array’s length should be cached to save gas in for-loops
Reading array length at each iteration of the loop takes 6 gas (3 for mload and 3 to place memory_offset) in the stack.
Caching the array length in the stack saves around 3 gas per iteration.
Suggest storing the array’s length in a variable before the for-loop, and use it instead:
++i costs less gas compared to i++
++i costs less gas compared to i++ for unsigned integer, as pre-increment is cheaper (about 5 gas per iteration)
Suggest using ++i instead of i++ to increment the value of an uint variable.
Increments can be unchecked
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.
taking all of the above, the recommended format for gas savings is
for (uint256 i; i < numIterations;) { // ... unchecked { ++i; } }
https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L309 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L717 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L739 https://github.com/code-423n4/2022-08-fiatdao/blob/main/contracts/VotingEscrow.sol#L834