I'm creating an automatic mechanism to turn all methods of classes to "private". Then I will add a __call method, to track down the callings. The only problem is how to do this without spoiling other strings, comments etc.
I want to track down all method callings, examine their running time, memory etc
There are already tools for that, search for php profiling, I could recommend xhprof.
If for some reason you don't want to use these, try Reflection