What open source tools could help me understand a large legacy application written in C?

Question

I need a tool that I can use to get a better understanding of a large C project. I'd like to be able to see the relationship between the various C modules and what calls what, most used functions, what headers are used, etc.

I've searched here and Google but all the source code analysis tools seem to give you the number of lines of code and other metrics that I'm not interested in. I just want to get a high level view of how things are structured and interconnected before jumping into the code.

Does anything like this exist?

I've looked at these but they do not seem to do what I want: Source Code Tools

Since posting this I've tried Doxygen and it seems to give me some of what I need. Any others?

Answer 1

Try GNU cflow, that will analyze the call tree of the functions - you will nicely see the call hierarchy of the functions. Or browse the code with Eclipse.