[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 2:00 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.

Thanks!
-Garrett