Understand parses any sized C or C++ project to help you reverse
engineer, document and understand it and thus maintain it better.
It supports K&R C, ANSI C, or C++ source code. Projects can contain
mixed C/C++ code as well. The parser is efficient, fast, and can
handle very large projects. Very little is needed to get started
- just aim it at your source tree.  Optionally (and for more parsing
accuracy) add any externally defined macro definitions and include
paths. All of this is done from the GUI - you should be able to do
an initial analysis of your project in a few minutes.

Understand for C++ quickly documents Class inheritance hierarchies
(Base Class and Derived Classes), Call and CallBy Trees, Include
and Include By Trees, as well as where and how everything in your
source code is used (cross reference). Understand for C++ creates
detailed automatic documentation about your source code in HTML
and text reports. Using the PERL and C API you can write your own
documentation generators.

You need a limited time period license to run the product in
evaluation mode or a purchased permanent license. Both can be
obtained in the www site.

WWW: http://www.scitools.com/