[Ada] Q about building cross gnatlib

[<guerby@acm.org>]

I'm trying to build GCC cross sparc-rtems from my i686-linux. After
installing the apropriate cross binutils, I succeed in building the
cross compiler then newlib thanks to Joel Sherrill detailed
instructions :).

I'm wondering wether the current ada/Makefile.in supports building
gnatlib in a cross setup, unless I'm missing something obvious I see
no way it can build the C part of the Ada RTS using the target newlib
since there seem to be no obvious place to specify where to find the
target includes in the current invocation:

gnatlib: ../stamp-gnatlib1 ../stamp-gnatlib2
#	../xgcc -B../ -dD -E ../tconfig.h $(INCLUDES) > rts/tconfig.h
	$(MAKE) -C rts CC="../../xgcc -B../../" \
	        INCLUDES="$(INCLUDES_FOR_SUBDIR) -I./../.." \
                CFLAGS="$(GNATLIBCFLAGS) $(TARGET_LIBGCC2_CFLAGS) -DIN_RTS" \
		ADA_CFLAGS="$(GNATLIBCFLAGS)" \
		srcdir=$(fsrcdir) \
	        -f ../Makefile $(LIBGNAT_OBJS)

Does the ACT tree (when building for VxWorks for example) have
specific patches to the Makefile to handle the situation? If they're
not completely ready for the FSF tree yet, could someone send them to
me, it would help a lot my efforts to setup a cross testing
environment for the various RTEMS targets. (Right now I'm kluding around
the Makefile in random places and not completely successful yet.)

-- 
Laurent Guerby <guerby@acm.org>