How to make sure that there is no undefined references to a module

[Ming-Ching Tiew]

I am trying to develope a little module of my own, the modules compiles fine.
But to make sure that my modules has no undefined references, I 
added this to the Makefile :-

RLM_LDFLAGS =  -Wl,--no-undefined

I tried the idea on one of the simplest module which comes with the 
sources, rlm_exec, but after that the module then failed to compile, 
having lots of undefined references.

eg :-
:273: undefined reference to `radlog'
:442: undefined reference to `radius_exec_program'

Any advise how should I go about fixing this problem ?