How to add -I to compile line?

[Thomas Gagne]

I was looking at the archives and discovered there wasn't a way to locally
search them.

I want to check for an include file in $GEMSTONE/include, and if its present
add -I$(GEMSTONE)/include to the compile options.  I then want to do the same
for some SYBASE include files.

I'm fairly certain a question like this is answered in the FAQ, but I can't
find it.

--
.tom