[RFC] adding a variable to .mk and Makefile.inc1 to point to top of the FreeBSD source tree

[Garrett Cooper]

On Tue, May 7, 2013 at 2:26 PM, Garrett Cooper <yanegomi at gmail.com> wrote:

>
> On Tue, May 7, 2013 at 2:00 PM, Warner Losh <imp at bsdimp.com> wrote:
>
>>
>> On May 7, 2013, at 2:46 PM, Garrett Cooper wrote:
>>
>> > On May 7, 2013, at 1:39 PM, Brooks Davis wrote:
>> >
>> >> On Tue, May 07, 2013 at 01:05:07PM -0700, Garrett Cooper wrote:
>> >>> Hi,
>> >>>   A common pattern that I've seen at Isilon and something else that
>> I've
>> >>> wanted to have for a while is the ability to designate where the top
>> of a
>> >>> source tree was. This is important and helpful when dealing with
>> source
>> >>> files that build upon each other or depend on sources located in other
>> >>> sections of the tree; contrib stuff needs to set .PATH appropriately
>> to
>> >>> point to sources at the top of the tree, sys stuff is riddled with S=
>> in
>> >>> order to point to where /sys, etc lives, we build upon FreeBSD within
>> an
>> >>> expected directory structure as well.
>> >>>   I haven't come up with a name, but was wondering if this was a good
>> >>> idea, and if so does anyone have any outstanding patches for this
>> that can
>> >>> be pushed into FreeBSD?
>> >>
>> >> I'd like to see this.  There's a variable for this in NetBSD and I've
>> >> wanted to do this because it makes code easier to relocate within the
>> >> tree.
>> >
>> >       This is another good reason. It would make porting code to/from
>> NetBSD a LOT easier… especially because I plan on pulling a lot of
>> test/test infrastructure code from NetBSD and I really don't want to commit
>> too many local changes to the Makefiles. Less divergence -> better
>> cross-pollination -> less work for all -> win for the BSDs.
>> >       Thanks for the reminder.. I'll base it off what NetBSD did :).
>>
>> SRCDIR
>>
>
> EVARINUSE?
>
> share/mk/bsd.doc.mk:# SRCDIR    Directory where source files live.
> [${.CURDIR}]
> share/mk/bsd.doc.mk:TRFLAGS+=   -I${SRCDIR}
> share/mk/bsd.doc.mk:.PATH: ${.CURDIR} ${SRCDIR}
> share/mk/bsd.doc.mk:    cd ${SRCDIR}; \
> share/mk/bsd.doc.mk:SRCDIR?=    ${.CURDIR}
> share/mk/bsd.doc.mk:    cd ${SRCDIR}; ${UNROFF} ${MACROS} ${UNROFFFLAGS} \
> share/mk/bsd.doc.mk:    cd ${SRCDIR}; ${UNROFF} -ms ${UNROFFFLAGS} \
> share/mk/bsd.info.mk:SRCDIR?=   ${.CURDIR}
> ...
> share/doc/llvm/Makefile:SRCDIR=         ${.CURDIR}/../../../contrib/llvm
> share/doc/llvm/Makefile:.PATH: ${SRCDIR} ${SRCDIR}/lib/Support
> share/doc/llvm/clang/Makefile:SRCDIR=
> ${.CURDIR}/../../../../contrib/llvm/tools/clang
> share/doc/llvm/clang/Makefile:.PATH: ${SRCDIR}
>
>
>> Once upon a time, this *HAD* to be set, and wasn't inferred from the
>> current top of the tree. Please, for the love of god, make sure that we
>> don't lose the infer from top of tree ability, or I will hurt you. Often.
>> Through all the minions that owe me minor favors.
>>
>
> I don't want to break that ever; it's a fantastic feature. If you could
> point me to where that magic awesomeness lives (make?), I'll be more than
> happy to address it in my branch where I'm going to do this.
>
> I really don't like how NetBSD turned their top-level build command into a
> shell script [in part because it needs to bootstrap a bunch of tools]. It
> makes things painful when doing iterative builds..
>
> So all in all, I completely and wholeheartedly agree with your concerns.
>

Oh sweet.. this is something to keep in mind too (from bsd.port.mk)...

# SRC_BASE      - The root of the src tree.  (Some ports require this to get
#                 kernel sources).  Default: /usr/src

All else fails, ports has done it first -_-...

Not the first var I've seen this done with...

Thanks,
-Garrett