On Mon, 2010-08-09 at 12:41 -0700, Philip Prindeville wrote:
Alas much of this is beyond my control, and it's not a single project:
it's a Linux distro having a couple of hundred projects, many of which
have several directories deep of makefile nesting.
Ah, well, you didn't say so :-).
One would suspect that if these are Linux distro packages, these
packages are all, or at least mostly, autoconfiscated. Autoconf (or
more specifically in this case, automake) obeys the GNU programming
standards which requires the behavior I already mentioned: that CFLAGS,
CPPFLAGS, CXXFLAGS, LDFLAGS, etc. are all reserved for use by the user,
and they can be overridden on the make command line without bad effects.
Basically they work just as I mentioned above.
Of course, there are always some people who don't like autoconf and
think it's too difficult, and instead create their own build/configure
systems. Well, these systems either ignore all the use-cases that make
autoconf difficult in the first place, and thus do not support the
features that people need in uncommon environments, and hence are not
useful/usable for any installation that doesn't closely match the
authors'; or else they're complicated in their own, non-standard way
which means more effort for the user (that's you) when they want to
build things.
Anyway. What was I talking about? Oh yes. Nevertheless most makefile
developers have resolved this issue one way or another, already. So you
shouldn't need to (and you shouldn't WANT to) rewrite all their
makefiles. You just have to learn how they did things.