idea.c missing function when complied under mac os x

[Andrew Tong]

I have been trying to compile the IDEA module under Mac OS X 10.1.2 with 
DevTools Dec-01. I think I solved the repeated definition issue by 
commenting out the line re "ushort". Then I compiled idea.c again and 
got the following error:

[localhost:~/] user1%cc -Wall -O2 -shared -fPIC -o idea idea.c
/usr/bin/ld: Undefined symbols:
_main
___eprintf
_g10_log_fatal

the term g10_log_fatal first appears in the code as:
/* imports */
void g10_log_fatal( const char *fmt, ... );

Is this function not defined? What to do next?

Any advice appreciated. Kindly CC me your replies.

Andrew