Fei Protocol contest - robee's results

Handle

robee

Vulnerability details

In the following files there are state variables that could be set immutable to save gas. The list of format <solidity file>, <state variable name that could be immutable>: There are some variables that I was not sure if are assigned actually twice in real use. I added them anyway.

    TRIBERagequit.sol, preMergeCirculatingTribe
    TRIBERagequit.sol, claimed

Handle

robee

Vulnerability details

Unused local variables are gas consuming, since the initial value assignment costs gas. And are a bad code practice. Removing those variables will decrease the gas cost and improve code quality. This is a full list of all the unused storage variables we found in your code base. The format is <solidity file>, <in which function we found it>, <unused local variable name>:

    TRIBERagequit.sol, requery, _pcvValue

Handle

robee

Vulnerability details

The following functions could be set external to save gas and improve code quality. External call cost is less expensive than of public functions.

    The function setExpirationBlock in PegExchanger.sol could be set external
    The function isEnabled in PegExchanger.sol could be set external
    The function party0Accept in PegExchanger.sol could be set external
    The function isExpired in PegExchanger.sol could be set external
    The function party1Accept in PegExchanger.sol could be set external
    The function exchange in PegExchanger.sol could be set external
    The function isEnabled in TRIBERagequit.sol could be set external
    The function ngmi in TRIBERagequit.sol could be set external
    The function requery in TRIBERagequit.sol could be set external
    The function party0Accept in TRIBERagequit.sol could be set external
    The function isExpired in TRIBERagequit.sol could be set external
    The function party1Accept in TRIBERagequit.sol could be set external
    The function recalculate in TRIBERagequit.sol could be set external

Handle

robee

Vulnerability details

The following functions could be set private to save gas and improve code quality: The function takeFrom in PegExchanger.sol could be set internal The function giveTo in PegExchanger.sol could be set internal The function verifyProof in TRIBERagequit.sol could be set internal The function takeFrom in TRIBERagequit.sol could be set internal The function processProof in TRIBERagequit.sol could be set internal The function giveTo in TRIBERagequit.sol could be set internal The function _startCountdown in TRIBERagequit.sol could be set internal

Handle

robee

Vulnerability details

Reading a storage variable is gas costly (SLOAD). In cases of multiple read of a storage variable in the same scope, caching the first read (i.e saving as a local variable) can save gas and decrease the overall gas uses. The following is a list of functions and the storage variables that you read twice:

    TRIBERagequit.sol Variable token1OutBase is read 2 times in the function:  recalculate
    TRIBERagequit.sol Variable minProtocolEquity is read 5 times in the function:  requery