DatingDapp
First Flight #33
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Submission Details
Severity: low
Invalid

[G-1] Missing constant/immutable variable declarations leads to unnecessary storage reads (Incorrect Variable Type + Gas Loss)

oks_oks

Description: Several state variables in the codebase are not marked as constant or immutable despite being set only once. Using these modifiers can save gas as:

  • constant variables are replaced by their value at compile time

  • immutable variables are read from code instead of storage

The following instances were found:

  1. In MultiSigWallet.sol:

// Should be immutable as they're only set in constructor
address public owner1;
address public owner2;

  1. In LikeRegistry.sol:

// Should be constant as it's a fixed value
uint256 immutable FIXEDFEE = 10;
​
// Should be immutable as it's only set in constructor
SoulboundProfileNFT public profileNFT;

Impact:

  • Each storage read costs 2100 gas (cold access) or 100 gas (warm access)

  • Using constant or immutable can save significant gas:

    • constant: No storage reads, value is embedded in bytecode

    • immutable: Single PUSH32 operation (3 gas) instead of SLOAD (100+ gas)

Proof of Concept:

Deploy the following contract in Remix to see the gas difference:

contract GasTest {
address public regularAddress = address(1); // 2593
address public immutable immutableAddress = address(1); // 439
address public constant CONSTANT_ADDRESS = address(1); // 417
​
function testRegularRead() public view returns (address) {
return regularAddress; // More expensive 2515
}
​
function testImmutableRead() public view returns (address) {
return immutableAddress; // Cheaper 402
}
​
function testConstantRead() public pure returns (address) {
return CONSTANT_ADDRESS; // Cheapest 358
}
}

Recommended Mitigation:

  1. For MultiSigWallet.sol:

- address public owner1;
- address public owner2;
+ address public immutable owner1;
+ address public immutable owner2;

  1. For LikeRegistry.sol:

- uint256 immutable FIXEDFEE = 10;
+ uint256 public constant FIXED_FEE = 10;
​
- SoulboundProfileNFT public profileNFT;
+ SoulboundProfileNFT public immutable profileNFT;
Updates

Appeal created

n0kto Lead Judge 6 months ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity
Assigned finding tags:

Informational or Gas

Please read the CodeHawks documentation to know which submissions are valid. If you disagree, provide a coded PoC and explain the real likelyhood and the detailed impact on the mainnet without any supposition (if, it could, etc) to prove your point.

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