Can you elaborate? It seems trivial - just scan every function call. Surely it's not possible to call a function without typing its name somewhere? (Obviously i

Can you elaborate? It seems trivial - just scan every function call. Surely it's not possible to call a function without typing its name somewhere? (Obviously if there's funny business with 'eval' this won't work, but then it reduces to the halting problem in the general case so that's fine. Most programs don't use eval.)