(yet another) Recursive make question

[Darin Johnson]

I'm building recursive makefiles for an existing project, and would like some
advice on some aspects I haven't seen mentioned much.

I'd like to use relative pathnames for include directoreis, so that the command
lines stay a manageable size (there may be over 100 include directories, at
least until I start figuring out which ones can be trimmed).  Is there a nice 
way
to either convert absolute paths to relative paths, or generate relative paths
on the fly when calling a sub-make?

Second, I'd like people to be able to type "make" from within a subdirectory
rather than having to be at the top level (which may be a few levels up).
Currently I've got a "build.mk" in each leaf directory and the "Makefile"s
are created by copying a template and updating the "TOP=..." line.  It seems
to work, but it's just a bit ugly (at least it's automatic so that "make 
makefiles"
isn't needed).  Does anyone have a better method?

Darin Johnson