Call graph for Modula-2

[Michael Riedl]

Hallo,

is anybody aware about a tool to generate a call graph for a Modula-2 
library / program ?

I would like to use such a tool to be sure that all procedures in a 
library are at least indirectly referred to in a test routine.

(well knowing that this might not be sufficient, but it would be at 
least a starting point :-)

Any hint would be helpful

Thanks in advance

Michael