Specifies that a sorted list of all modules used in the
program be printed. This list is in ``prerequisite'' order, i.e. each
module is printed only after all the modules from which it is called
have been printed. This is also called a ``topological sort'' of the
call tree. Each module is listed only once. Routines that are not in
the call tree of the main program are omitted. If there are any
cycles in the call graph (illegal in standard Fortran) they
will be detected and diagnosed. Default = no.
See also: -calltree,
-crossref, -reference, -symtab, -vcg.