Change to config(8) for OFED

[M. Warner Losh]

In message: <alpine.BSF.2.00.1006122328470.1435 at desktop>
            Jeff Roberson <jroberson at jroberson.net> writes:
: On Sun, 13 Jun 2010, M. Warner Losh wrote:
: 
: > In message: <86zkz05bra.fsf at ds4.des.no>
: >            Dag-Erling Sm?rgrav <des at des.no> writes:
: > : "M. Warner Losh" <imp at bsdimp.com> writes:
: > : > but NORMAL_C is
: > : >
: > : > NORMAL_C= ${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
: > : >
: > : > and .IMPSRC is null.  That seems like a bug to me, but I'm not
: > sure if
: > : > the bug is that .IMPSRC is computed wrong, or if it really should
: > be
: > : > ${.ALLSRC}
: > :
: > : .IMPSRC is the *implicit* source and is only valid in *implicit*
: > rules.
: > : Consider the following:
: > :
: > : .SUFFIXES: .foo .bar
: > : .foo.bar: foo2bar.sh
: > :         /bin/sh foo2bar.sh ${.IMPSRC} ${.TARGET}
: > :
: > : When building hello.bar from hello.foo, .IMPSRC is "hello.foo" but
: > .ALLSRC
: > : is "hello.foo foo2bar.sh".
: >
: > Yes, it appears to be set only when the target matches the object, so
: > the .c.o rule matches, even if the more specific one is used (where
: > there is not a match).
: >
: > : GNU make has a way of defining more complex implicit rules (pattern
: > : rules).  If we had something similar, we could do:
: > :
: > : foo_%.o: %.c
: > :         ${NORMAL_C}
: >
: > Yes.  I'm starting to think that this would be necessary to implement
: > this properly.  Or, as Jeff suggested, have config generate a complete
: > compile line with -o foo_bar.o -c bar.c in the line...
: 
: Here's what I ended up with:
: 
: In kern.pre.mk:
: 
: +OFED_C_NOIMP=  ${CC} -c ${OFEDCFLAGS} ${WERROR} ${OFEDNOERR} ${PROF}
: +OFED_C=                ${OFED_C_NOIMP} ${.IMPSRC}
: 
: I don't use NORMAL_C as linux doesn't use some warnings that we
: specify and I need to modify the include path to search the linux
: wrapper paths first.
: 
: in files:
: +ofed/drivers/infiniband/hw/mlx4/ah.c optional mlx4 \
: + no-depend obj-prefix "mlx4_" \
: + compile-with "${OFED_C_NOIMP} -I$S/ofed/drivers/infiniband/hw/mlx4/"
: 
: Generated Makefile:
: mlx4_ah.o: $S/ofed/drivers/infiniband/hw/mlx4/ah.c
:         ${OFED_C_NOIMP} -I$S/ofed/drivers/infiniband/hw/mlx4/
:         $S/ofed/drivers/infiniband/hw/mlx4/ah.c
: 
: 
: And the patch to config:
: http://people.freebsd.org/~jeff/objprefix.diff
: 
: The full source path is only emitted when an object prefix is set.  If
: you don't like this diff please speak now before I commit.  It will go
: to my private branch for ofed first but I'm sure I'll forget about it
: before I merge.
: 
: I still need to change config so it will do proper depends for files
: which require extra includes.  Before then I just specify no-depend
: for ib.
: 
: Is it possible to set make variables within targets?  I can export
: shell variables since that's an executable command.  I could then
: refer to the shell variables in the scripts but that seems really
: gross.

No.  You can't set make variables within targets, unless you are doing
subtargets:

foo.o: bar.c
	(cd subdir; make FRED=WILMA BARNEY=BETTY gerbils)

Warner