I think the other problem is that static analysis is a great tool for a new code base. But a new code base has no dead code. Or to put it another way, when you

I think the other problem is that static analysis is a great tool for a new code base. But a new code base has no dead code. Or to put it another way, when you're designing a system, please think about the benefit static analysis will have in identifying dead code three years hence. But when you're trying to find dead code in that ten year old PHP code no amount of woulda's and coulda's will get rid of it. The intelligent person solves the problem they've got. The unintelligent person shoulda's coulda's and woulda's you into oblivion. (NB. I would probably choose a tool with a good type system, and I would try to write to its strengths, in any system I was designing today. But that still doesn't help me identify the dead code I've got.)