InitializableOwnable Code Style Findings

IOL-01C: Bytecode Optimization

Description:

The way modifier implementations work in Solidity is by inserting code on each function with a modifier each time. This leads to a significant increase in bytecode and deployment cost if the modifier contains complex statements, such as a require with a long error message.

Example:

Copy
40modifier onlyOwner() {
41    require(isOwner(), "InitializableOwnable: caller is not the owner");
42    _;
43}

Recommendation:

We strongly recommend an internal function to be created instead called _onlyOwner() that is in turn invoked by the onlyOwner modifier thus only inserting a jump instruction on each modifier-boasting function.

Alleviation:

An internal function performing the exact same require checks as the modifier previously did was introduced called _onlyOwner and consequently invoked by the modifier of the exhibit.