Dependency graph for functions across modules


Is there a package to find the dependency graph (not sure if this is the right term) for functions across modules. For example, with:

using A, Z
function b(x)
   return a(x)+1     # A.a(x) not inexistent Z.a(x)
function c(x)
   return a(x)*b(x)

would like to get something like

b depends A.a
c depends A.a, b