How to find out where and what functions are called?

Question

Yii

There is a large PHP5 + Yii2 project (about 50 models, forms, many controllers, etc.)
This code needs to be optimized, because I am sure that some of the functions are not used anywhere at all.
How to do it?
How to find out which functions are not used, as well as find out all the places of function calls that are used.

Answer 1

In PhpStorm, you can right-click on a function and select "find usage". In some Netbeans, most likely, too.