There are some more changes I'd like made to config(8):

1) Add `source' and `build' directives to the config file, specifying
where the source and build directories are, respectively.  These will
allow you to have a build directory completely disjoint from the
source directory -- important for read-only source trees.  Also, for
those of you who long for /sys/compile, you can trivially do that if
you like.

It's possible that you'd also want options to override these; e.g. so
that you can run config(8) with the original config files in
/sys/arch/foo/conf, but stick the build tree somewhere else.

(Details: These will have defaults.  If `source' is a relative path,
it's relative to `build'.  config(8) will insert the definition for
`S' into the Makefile along with the other variables it creates.)

2) Add a default config file name.  Combined with the above, you can
trivially arrange for `cd /sys/compile/SOMEHOST; make clean; config;
make' to work.

I could probably make a case for actually copying the config file into
the build directory, if it's not already there, but I'm not
particularly attached to this idea.


Any comments on the above?


If you'd like to try them out, Greg Hudson <ghudson@mit.edu> has done
a first cut of these changes.