PHP_Depend
This plugin performs static code analysis on a given source base. PHP_Depend first parses the source code into an easily processable internal data structure, and then measures several software metrics. Each of these metrics can be used to measure the quality of a project, and can help identify those parts of your application needing refactoring.
How do I install the PHP Depend plugin?
How do I work with the PHP Depend plugin?
For more details on PHP_Depend, click here.