Not quite what you're asking but once I've narrowed down a code base to the particular area of interest, I use an old school method for grokking: Print the rel

Not quite what you're asking but once I've narrowed down a code base to the particular area of interest, I use an old school method for grokking: Print the relevant sections off to read and use pen to mark and note against them; I find it extremely useful (and less tiring on the eyes) for linking functions and clarifying code.