[Pdx-pm] documenting spaghetti code

[Selena Deckelmann]

Hello,

Apologies if this is a really dumb question.

I have some really horrific code (in C) that I need to make a few  
changes to. Unfortunately, I must learn how most of the code works  
before I make the changes. There are about 20k lines, there is no  
test suite and the code is largely undocumented.

I'm also working with some engineers who are not programmers, but  
need to know how the software works in order to make intelligent  
suggestions on improving it (it is a physical process, run by a  
microcontroller).

I am struggling with how to document the code in a way that is  
helpful to us all. I did find some code beautifiers to make reading a  
bit less painful.

For the docs, I've started by making a flowchart that walks through  
the logic and identifies which files subroutines can be found in. Is  
this what I should be doing? Am I doing way too much work? Is there  
some really awesome perl tool that maps out a function/tree structure  
for me? Is there some other way to do this?

thanks,
selena