Modifying CPPFLAGS for a port

[Jason Lixfeld]

I've been digging around trying to debug an issue with OpenLDAP and I 
need to compile the port with -g and without -O.  I can add -g into the 
CPPFLAGS by exporting the variable before running make, however I can't 
figure out where the CPPFLAGS are passed from make to the configure 
script for the actual source code.  Can anyone give me some pointers?

Thanks in advance.