gnerating deps with cpp

[Victor Secarin]

Hello all,

I am using gcc 2.95.2 and the cpp that comes with it.
When I compile, the compiler defines __GNUC__ ; however, if I generate
deps with cpp (rather than with gcc -M) then I need to define __GNUC__
by hand (or else my header files will work differently which of course
is bad). 
Is there a reason?

Thanks,
Victor Secarin
developer,
Paradigm Geophysical,
Calgary, Alberta, Canada