Multilibs with different configs (different include-paths)?

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

I have a cross toolchain where one of the multilibs has
different include files than the others.  The current multilib
machinery caches include-configs across all multilibs, so things
break when the target libiberty builds, because of the resulting
incorrect config.h (IIRC).

I'd like to solve this by letting a target-triple add options
for sub-configs of listed targets, probably through a patch to
(hopefully only) toplev/configure.in.  For example, in this case
it would add "--cache-file=/dev/null" for subdirs of the triple
cris-axis-none (or cris-axis-multi) letting its -mlinux multilib
be configured right; with the installed headers.

Is that solution (or a solution in that direction) acceptable?
Any better ideas?  I don't want to be forced to split up the
tool-chain into more than one because of that minor config
difference.

People replying should know that any --cache-file option passed
at configure-time is filtered-out by toplev/configure.in.  A
solution might be to remove that filtering, but that kind of
solution would mean some configure options are mandatory for
some targets; in this case you'd always have to provide
--config-cache=/dev/null for a target with multilib-dependent
include paths.

brgds, H-P