0xNazgul-G.md

[NAZ-G1] Use of 2**256 - 1 && type(uint256).max When 2**255 Can Be Used

Context: ProposalExecutionEngine.sol#L161

Description: Infinity can also be represented via ``2255, it's hex representation is 0x8000000000000000000000000000000000000000000000000000000000000000` while `2256 - 1` is `0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff`. Then main difference is and where the gas savings come from is, zeros are cheaper than non-zero values in hex representation.

Recommendation: Use 2**255 instead of 2**256 - 1 to save gas on deployment.

[NAZ-G] Use ++index instead of index++ to increment a loop counter

Context: CollectionBuyCrowdfund.sol#L62

Description: Due to reduced stack operations, using ++index saves 5 gas per iteration.

Recommendation: Use ++index to increment a loop counter.

[NAZ-G2] The Increment In For Loop Post Condition Can Be Made Unchecked

Context: CollectionBuyCrowdfund.sol#L62, ArbitraryCallsProposal.sol#L52, ArbitraryCallsProposal.sol#L61, ArbitraryCallsProposal.sol#L78, TokenDistributor.sol#L230, TokenDistributor.sol#L239, Crowdfund.sol#L180, Crowdfund.sol#L242, Crowdfund.sol#L300, Crowdfund.sol#L348, PartyGovernance.sol#L306, ListOnOpenseaProposal.sol#L291, LibProposal.sol#L14, LibProposal.sol#L32

Description: (This is only relevant if you are using the default solidity checked arithmetic). i++ involves checked arithmetic, which is not required. This is because the value of i is always strictly less than length <= 2**256 - 1. Therefore, the theoretical maximum value of i to enter the for-loop body is 2**256 - 2. This means that the i++ in the for loop can never overflow. Regardless, the overflow checks are performed by the compiler.

Unfortunately, the Solidity optimizer is not smart enough to detect this and remove the checks. One can manually do this by:

for (uint i = 0; i < length; ) {
    // do something that doesn't change the value of i
    unchecked {
        ++i;
    }
}

Note that it’s important that the call to unchecked_inc is inlined. This is only possible for solidity versions starting from 0.8.2.

Recommendation: Consider doing the increment in the for loop post condition in an unchecked block.

[NAZ-G3] Catching The Array Length Prior To Loop

Context: CollectionBuyCrowdfund.sol#L62, ArbitraryCallsProposal.sol#L52, ArbitraryCallsProposal.sol#L61, ArbitraryCallsProposal.sol#L78, TokenDistributor.sol#L230, TokenDistributor.sol#L239, Crowdfund.sol#L180, Crowdfund.sol#L300, PartyGovernance.sol#L306, ListOnOpenseaProposal.sol#L291, LibProposal.sol#L14, LibProposal.sol#L32

Description: One can save gas by caching the array length (in stack) and using that set variable in the loop. Replace state variable reads and writes within loops with local variable reads and writes. This is done by assigning state variable values to new local variables, reading and/or writing the local variables in a loop, then after the loop assigning any changed local variables to their equivalent state variables.

Recommendation: Simply do something like so before the for loop: uint length = variable.length. Then add length in place of variable.length in the for loop.

[NAZ-G4] Setting The Constructor To Payable

Context: All Contracts

Description: You can cut out 10 opcodes in the creation-time EVM bytecode if you declare a constructor payable. Making the constructor payable eliminates the need for an initial check of msg.value == 0 and saves 21 gas on deployment with no security risks.

Recommendation: Set the constructor to payable.

[NAZ-G5] Use of Custom Errors Instead of String

Context: All Contracts

Description: To save some gas the use of custom errors leads to cheaper deploy time cost and run time cost. The run time cost is only relevant when the revert condition is met.

Recommendation: Use Custom Errors instead of strings.

[NAZ-G6] Function Ordering via Method ID

Context: All Contracts

Description: Contracts most called functions could simply save gas by function ordering via Method ID. Calling a function at runtime will be cheaper if the function is positioned earlier in the order (has a relatively lower Method ID) because 22 gas are added to the cost of a function for every position that came before it. The caller can save on gas if you prioritize most called functions. One could use This tool to help find alternative function names with lower Method IDs while keeping the original name intact.

Recommendation: Find a lower method ID name for the most called functions for example mostCalled() vs. mostCalled_41q() is cheaper by 44 gas.

[NAZ-G7] Upgrade To At Least 0.8.4

Context: All Contracts

Description: Using newer compiler versions and the optimizer gives gas optimizations and additional safety checks for free!

The advantages of versions =0.8.*= over =<0.8.0= are:

• Safemath by default from =0.8.0= (can be more gas efficient than /some/ library based safemath).
• Low level inliner from =0.8.2=, leads to cheaper runtime gas. Especially relevant when the contract has small functions. For example, OpenZeppelin libraries typically have a lot of small helper functions and if they are not inlined, they cost an additional 20 to 40 gas because of 2 extra =jump= instructions and additional stack operations needed for function calls.
• Optimizer improvements in packed structs: Before =0.8.3=, storing packed structs, in some cases used an additional storage read operation. After EIP-2929, if the slot was already cold, this means unnecessary stack operations and extra deploy time costs. However, if the slot was already warm, this means additional cost of =100= gas alongside the same unnecessary stack operations and extra deploy time costs.
• Custom errors from =0.8.4=, leads to cheaper deploy time cost and run time cost. Note: the run time cost is only relevant when the revert condition is met. In short, replace revert strings by custom errors.

Recommendation: Upgrade to at least 0.8.4 for the additional benefits.