zkSync Era System Contracts contest - bshramin's results

Reduce nestedness and complexity

Reducing the nestedness and complexity of the code will make it easier to read and understand. In knownCodesStorage.sol, in function _markBytecodeAsPublished we can change the body of the function to the following:

if (getMarker(_bytecodeHash) != 0) {
    return;
}

_validateBytecode(_bytecodeHash);

if (_shouldSendToL1) {
    _sendBytecodeToL1(_bytecodeHash, _l1PreimageHash, _l1PreimageBytesLen);
}

// Save as known, to not resend the log to L1
assembly {
    sstore(_bytecodeHash, 1)
}

emit MarkedAsKnown(_bytecodeHash, _shouldSendToL1);

Use revert instead of return

In the fallback function of MsgValueSimulator, there is a condition that we know it should not happen but it's there for safety. However if this happens and user sends a amount more than MAX_MSG_VALUE the function will return and the user will not get any refund. We should use revert instead of return on line 55 or move the condition to the beginning of the function.

This is the condition:

if (value > MAX_MSG_VALUE) {
    // The if above should never be true, since noone should be able to have
    // MAX_MSG_VALUE wei of ether. However, if it does happen for some reason,
    // we will revert(0,0).
    // Note, that we use raw revert here instead of `panic` to emulate behaviour close to
    // the EVM's one, i.e. returndata should be empty.
    assembly {
        return(0, 0)
    }
}

Test function not removed from the code

In the file SystemContext.sol, the function unsafeOverrideBlock was meant only for testing purposes, but it was not removed from the code.

Mistakes in the comments

• In knownCodesStorage.sol on line 14, the word words at the end of the line should be removed
• In NonceHolder.sol on line 17, the word marked should be replaced with mark
• In SystemContext.sol on line 36, the word will should be changed to set it to
• In SystemContext.sol on line 64, The comment was copied from the above function and is not correct
• In SystemContext.sol on line 71, the word when should be removed