Dependency tracer

[MR ZenWiz]

Is there a good tool that can trace source dependencies given a tree
containing various directories of source files?

I have a project that has make files with no dependency targets and
would like to be able to take a particular header and see all the
files that depend on it, directly or indirectly, and vice-versa.

i'm no make expert, but the way our makefiles are built they are
virtually incomprehensible without a guru and sometimes even then.

Thanks.

MR