Summary

Code for the modifier is copied by the compiler inside the function that is using the modifier.

Vulnerability Details

The code from the modifier is copied inside each function by the compiler. If the code inside the modifier is very large and some functions are using the modifier then the deployment would cost more gas.

for example this if condition would be copied inside each function that is using this modifier

Impact

This would cost some extra gas for the contract deployment.

Tests done on the Remix IDE for getting the gas cost:

As we can see if we use the special functions for checking the modifier code then it would cost less gas.

Tools Used

Foundry test, remix ide

Recommendations

consider using this:

By using the above way, only these line would be copied down inside the functions