PartyDAO contest - Tomio's results

Title: Consider remove empty block

impact: The code should be refactored such that they no longer exist, or the block should do something useful, such as emitting an event or reverting.

Proof of Concept: Party.sol#L47 AuctionCrowdfund.sol#L144

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Title: Expression for constant values such as a call to keccak256(), should use immutable rather than constant

Proof of Concept: ProposalStorage.sol#L19

Recommended Mitigation Steps: Change from constant to immutable reference: here

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Title: Comparison operators

Proof of Concept: ArbitraryCallsProposal.sol#L156 Crowdfund.sol#L423

Recommended Mitigation Steps: Change to:

	if (call.data.length > 3) {

Replace <= with <, and >= with > for gas optimization

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Title: abi.encode() is less efficient than abi.encodePacked()

Proof of Concept: ListOnZoraProposal.sol#L115

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Title: >= is cheaper than >

Impact: Strict inequalities (>) are more expensive than non-strict ones (>=). This is due to some supplementary checks (ISZERO, 3 gas)

Proof of Concept: TokenDistributor.sol#L167

Recommended Mitigation Steps: Consider using >= instead of > to avoid some opcodes

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Title: Using unchecked can save gas

Proof of Concept: TokenDistributor.sol#L167-L170

Recommended Mitigation Steps: using unchecked can save gas (because amountClaimed > remainingMemberSupply)

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Title: Caching length for loop can save gas

Proof of Concept: TokenDistributor.sol#L239 TokenDistributor.sol#L230 ListOnOpenseaProposal.sol#L291 crowdfund/Crowdfund.sol#L180

Recommended Mitigation Steps: Change to:

	uint256 Length = infos.length;
	for (uint256 i = 0; i < Length; ++i) {

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Title: Using unchecked and prefix increment is more effective for gas saving:

Proof of Concept: TokenDistributor.sol#L239 TokenDistributor.sol#L230 ListOnOpenseaProposal.sol#L291 crowdfund/Crowdfund.sol#L180

Recommended Mitigation Steps: Change to:

	for (uint256 i = 0; i < infos.length;) {
	// ...
	unchecked { ++i; }
	}

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Title: Default value initialization

Impact: If a variable is not set/initialized, it is assumed to have the default value (0, false, 0x0 etc depending on the data type). Explicitly initializing it with its default value is an anti-pattern and wastes gas.

Proof of Concept: TokenDistributor.sol#L239 TokenDistributor.sol#L230 ListOnOpenseaProposal.sol#L291 crowdfund/Crowdfund.sol#L180 PartyGovernance.sol#L432

Recommended Mitigation Steps: Remove explicit initialization for default values.

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Title: calldata instead of memory for RO function parameters

Impact: If a reference type function parameter is read-only, it is cheaper in gas to use calldata instead of memory. Calldata is a non-modifiable, non-persistent area where function arguments are stored, and behaves mostly like memory.

Try to use calldata as a data location because it will avoid copies and also makes sure that the data cannot be modified.

Proof of Concept: BuyCrowdfundBase.sol#L70

Recommended Mitigation Steps: Replace memory with calldata

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Title: function _getFinalContribution(): L#358 should be unchecked due to L#350

Proof of Concept: Crowdfund.sol#L358

Recommended Mitigation Steps: Use unchecked

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Title: Gas optimization for increment or decrement

Proof of Concept: Title: Cheaper to use ++ instead + 1

Proof of Concept: PartyGovernance.sol#L440

Recommended Mitigation Steps: instead of using +1 replace it with ++

	low = ++mid;

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Title: Gas optimization to dividing by 2

Proof of Concept: PartyGovernance.sol#L434

Recommended Mitigation Steps: Replace / 2 with >> 1

Reference: here

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Title: using delete statement can save gas

Proof of Concept: PartyGovernance.sol#L708

Recommended Mitigation Steps: Change to:

      delete proposalState.values.completedTime;

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Title: Gas savings for using solidity 0.8.10

Proof of Concept: All contract in scope

Recommended Mitigation Steps: Consider to upgrade pragma to at least 0.8.10.

Solidity 0.8.10 has a useful change which reduced gas costs of external calls Reference: here

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