This post is more to document my own “discovery” and not to get into the loop of researching the same topic again and again. And if someone finds it helpful its great. I was searching for PHP static code analysis tools that generate call graphs and for my surprise the tool that I found most useful is the handy Doxygen – documentor fot PHP code.

The installation, configuration and the operation of the tool is straightforward.

You configure Doxygen  behaviour per project which I found very convenient.
The standard outputs formats are HTML and LaTex. Doxygen depends on Graphviz “dot” tool to generate all class and call graphs so you better have graphviz in advance.