When approaching a new code, even for embedded software written in C, it is common to face a large number of big files, with no/scarce/wrong comments.

In this situation, to have a basic understanding of the modules and their interaction, I often use Doxygen, that it is great to get graphical representations of function call trees and directory dependencies. But I would like to get also some info about data flows, to have a more complete overview of the architecture. For example, the messages exchanged between tasks (if an operating system is used) or global variables/flags that are set/read/reset by two or more modules (it should not go like that, but unfortunately it happens, sometimes).

Is it possible to get this type of output?