How can I visualize Fortran (90 or later) source code, e.g. using Graphviz?

Question

I've been thrown into a large Fortran project with a large number of source files.

I need to contribute to this project and it would seem prudent that I first understand the source.

As a first step, I'd like to visualize the interdependences between the various source files, i.e. which source files need which modules. As far as I can tell, automated methods exist for other languages and result in a graph that can be built using Graphviz.

But is anyone aware of software out there that can do this for Fortran 90 code?

[Searching the interwebs for Fortran help is a real pain as you end up searching the inter-cobwebs thanks to the painfully ubiquitous FORTRAN 77.]

Answer 1

If you have money then Understand for Fortran is worth looking at. If you don't have money but intend to work quickly then you might get by with a trial download of the software.

For a static call graph, I've never found a free tool as useful as Understand; it's hard to find any free tools let alone a useful one. I'd write one myself but the market would be tiny :-(

For a dynamic call graph investigate your compiler options. I use the Intel Fortran Compiler which can generate a mound of useful information about an executing program. The TotalView debugger can also visualise the call graph of an executing program. You should also look at gprof2dot which makes a DOT file out of a GPROF call 'graph'. This is free and OK.

And I should also add, though it's not something I've ever used, that Callgrind may be of use.