Re: [jamboost] Wrapping up new design

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2002-01-08 13:43:43

----- Original Message -----
From: "Vladimir Prus" <ghost_at_[hidden]>

> David Abrahams wrote:
>
> > > Then, the whole method will work like:
> > > 0. If JAMBASE/BOOST_BUILD_PATH/BOOST_ROOT are empty, stock jambase is
> > > loaded.
>
> > I think at this point there are too many variables which have to be
empty,
> > and I'd like to reduce that number. I think this "crawl up" behavior is
> > enough to eliminate the need for any of those to be set in the other
case.
>
> Do you mean to eliminate currect jambase selection semantics? I don't
think
> we need that -- IIRC, you've said yourself that most projects don't want
to
> specify build system location in top-level project config file.

Perhaps you're right. I do get the sense that three ways to get out of the
default Jam behavior is too many.

note: the crawl-up behavior is also good if you put all of your development
work below a common directory :-)

> Okay. And if that top-level file is not found, we resort to default jam
> behaviour. This is exactly what Rene has implemented.

Good.

> > > 2. If it contain a rule to tell where actual build system files are
> > > located,
> > > those a loaded in the same way as with BOOST_BUILD_PATH.
> > That's a little imprecise. Perhaps we just want to say that
> > project-root.jam has an opportunity to modify BOOST_BUILD_PATH.
>
> Maybe so. But, in case project-root.jam contains something more that
variable
> assignments, boost-build.jam must be included before the first thing that
> relies on boost-build.jam being already included.

Yes.

> > That JAM_TOOLSET business is an FTJam enhancement which I'm not sure I
want
> > to keep. Does anyone have opinions?
>
> I don't remember the exact list of changes, but I guess Jam won't work
with
> borland without them? If so, I think it's better to keep the changes.

OK.