Use Of Deprecated Functions

Detection Heuristics

1. Search for each deprecated keyword: suicide, sha3, block.blockhash, callcode, throw, msg.gas, constant (as function modifier), var
2. Search for selfdestruct — while it's the replacement for suicide, it is itself deprecated post-Dencun and non-functional on some chains
3. Check compiler warnings for deprecation notices
4. Flag any usage and recommend the modern replacement

False Positives

• The deprecated function appears in comments or documentation, not in executable code
• The contract is intentionally targeting an old Solidity version where the deprecated feature is still standard
• Interface definitions that reference deprecated patterns for backward compatibility

Remediation

• Replace each deprecated function with its modern equivalent (see table above)
• For selfdestruct: remove reliance entirely, as it is deprecated and non-functional on some chains post-Dencun
• Upgrade the Solidity version to benefit from compiler enforcement of modern syntax

// Modern equivalents
pragma solidity 0.8.24;

contract Modern {
    function getHash(bytes memory data) external pure returns (bytes32) {
        return keccak256(data);
    }

    function getBlockHash(uint256 n) external view returns (bytes32) {
        return blockhash(n);
    }

    function getRemainingGas() external view returns (uint256) {
        return gasleft();
    }
}