how to get doxygen to produce call & caller graphs for c functions

I've spent some time reviewing the docs and going through my doxy config file from end to end. I cut doxygen loose on my config file and it produces documentation and indices for structs and cpp classes but I don't see call or caller graphs for the multitude of c functions in my source tree.

Can anybody tell me how to configure doxygen to produces these call and caller trees ? I do have graphviz installed.

You have to set HAVE_DOT, CALL_GRAPH and CALLER_GRAPH to YES. Also make sure the path to dot is in your PATH variable.

If that still doesn't work, you might have to set EXTRACT_ALL and/or EXTRACT_STATIC, depending on your functions.

doxywizard is also useful. It gives you all the options in a GUI. Selecting any option shows quick help about that option.

You might also be interested in COLLABORATION_GRAPH or GRAPHICAL_HIERARCHY.

Quite convenient.