Giuliano Bertoletti wrote:
> What I'm wondering is if there's some way to set an extern environment
> variabile and have the compiler read it and use when deciding which
> portion to compile.
That's precisely the reason why a bunch of people have developed tools to
set up automated build scripts. For example, the GNU build system is used
to generate a header file typically named config.h, which is used to set all
the relevant platform-specific info needed in the build process.
Rui Maciel
[1]
http://www.gnu.org/savannah-
checkouts/gnu/autoconf/manual/autoconf-2.68/html_node/autoheader-
Invocation.html#autoheader-Invocation