I am trying to add some new compile flags to gcc via the CPP variable.
First I tried editing system.mk and running autogen.sh and then
configure but it is overwriting my changes. And CCP shows up as just
the normal "gcc -E", so next I tried looking at configure.in but it
doesn't seem to be directly set in there, yet it looks like
configure.in is telling configure to overwrite my changes in system.mk
thus they are not propagated to the Makefile. I also tried this same
process using CPPFLAGS but same result. I asked Quozl but he didn't know.