Re: mergemaster broken?

On Tue, Mar 21, 2006 at 01:22:39PM -0800, Doug Barton wrote:
> I'm including rwatson here since the MACHINE_ARCH stuff was his idea.
> 
MACHINE_ARCH should be spelled TARGET_ARCH when doing cross
stuff properly.

> Ruslan Ermilov wrote:
> 
> >> On Mon, Mar 20, 2006 at 03:40:06PM -0800, John-Mark Gurney wrote:
> >>> Should we also document that -m is suppose to be src's etc dir instead
> >>> of src?  I've accidentally pointed -m at src, and then it does a make
> >>> which is quite ammuzing as it's completely the wrong thing...  Or now
> >>> that we call outside of /etc, should we make -m really point to src,
> >>> and have the proper calls add etc to the directory?
> 
> I strongly dislike the idea of changing the semantics of the -m option. It's
> been the way it is since day 1, and I really hate to make changes to
> something like that. I can see a case for making the man page more clear,
> but I'd rather work around the problem with -m than change the semantics.
> 
> > Doesn't really matter, mergemaster(8) was broken because it was
> > written when we didn't have correct wrappers for "distrib-dirs"
> > and "distribution", upgrade and cross-arch friendly, at the top
> > level.
> > 
> > Anyway, attached is the patch I'd like to commit after a nod
> > from Doug.  It fixes mergemaster(8) to use src/Makefile wrappers
> > for distrib-dirs and distribution targets, and makes it use
> > TARGET_ARCH instead of faking up MACHINE_ARCH, now that it uses
> > the correct wrappers.  It also makes ${SOURCEDIR} and -m point
> > at the src/ top, as documented in a manpage.
> 
> Forgive me if I'm being dense here, but why do the changes you describe
> require that we run make in src/?
> 
You didn't read this thread from beginning, did you?  OK, I will
explain it in a bit more detail.

The time you're running "mergemaster -p", you run src/etc/Makefile
which may be incompatible with installed make(1) binary and/or
/usr/share/mk files (like is the case for this thread).  By using
the top level wrappers, all these problems are solved.  Wrappers
execute src/etc/Makefile targets in upgrade- and cross-friendly
environment, with bootstrapped make(1) binary and src/share/mk
files.

> Or, alternatively, if it is _absolutely_
> necessary to do so, why do we have to redefine SOURCEDIR to be src, and why
> can't we just strip /etc from SOURCEDIR where needed?
> 
My original diff didn't change that, I think someone else
asked to change it, and it was pretty logical (see below).

> In short, I have no objections to fixing mergemaster to work with the new
> world order, but it needs to be done in a way that does not change semantics
> of an existing option. I'd also like confirmation from Robert that we're not
> breaking any of the behavior that he added by doing it the way you propose.
> 
OK, you have my patches, do what you want with them.  I don't
care which directory the -m option uses, but there's not much
sense keeping it pointing to src/etc/ if we're going to use
the top-level Makefile and its targets.  Absolutely what needs
to be done:

1) Fix mergemaster(8) to use top-level targets for distrib-dirs,
   distribute, and obj/all in "etc".  The latter should be more
   obvious -- my changes fixes it so it runs obj/all in etc in
   the same environment as buildworld does, i.e., using adequate
   tools.

2) s/MACHINE_ARCH/TARGET_ARCH/, i.e., don't pretend we're a
   TARGET_ARCH.  When needed top-level makefiles will
   substitute MACHINE_ARCH=${TARGET_ARCH}.

3) Grow support for TARGET for pc98, better through the
   "arch[:machine]" format of the -A option's argument.

Some reference commits from src/Makefile:

: revision 1.320
: date: 2005/07/15 14:38:54;  author: ru;  state: Exp;  lines: +1 -1
: Make the `distrib-dirs' target official and working properly
: when cross-building (installing).  (This is useful for NFS
: installing world/kernel to another architecture machine.)
: 
: revision 1.317
: date: 2005/02/27 12:11:34;  author: ru;  state: Exp;  lines: +2 -1
: Added the convenience "distribution" target which calls the
: target of the same name from src/etc/Makefile with a proper
: environment, suitable to be used during upgrades and cross-
: builds.


Cheers,
-- 
Ruslan Ermilov
ru_at_FreeBSD.org
FreeBSD committer