Re: [jamboost] Re: Boost support: --help in top-level dir; installting libs

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-06-17 03:00:48

On Friday 17 June 2005 11:52, Rene Rivera wrote:

> >>I think something like the latter. The help system was designed to be
> >>modular, so it should be possible to do something non-intrusive for
> >>each project. Maybe
> >>
> >> --help-boost
> >
> > Fine with me. We'd need to restructure the --help output to be more
> > accessible to users, but overall adding --help-boost should work.
>
> Instead of the three options above I prefer:
>
> [ ] Make --help produce Boost.Build online help and any help docs in the
> current Jamfile. (I think I mentioned this when I first brought this up.)

I think that's what ant does -- it can produce help text defined for the
current project.

I thought about this syntax:

constant project-help : "This is C++ Boost!" ;

and the --help would grab the "project-help" constant from the current 
project.

> That rule would handle the case we want in a more flexible and modular
> manner. For top level install help we just put the docs in the
> boost-root/Jamfile. This opens the feature to outside projects. And also
> lets library authors add their own custom help in the library build file.

Should library-specific help replace or complement Boost help? Anyway, with
"constant" it would be possible to do:

constant project-help : "This is a cool boost library" $(project-help) ;

And it would add the text to inherited "project-help".

> The only problem I see with this suggestion is that we also want the top
> level install help available when we are in a library subdir without
> repeating it in every Jamfile. So a more general rule to handle that
> possibility would be:
>
> [ ] Make --help produce any help docs in the "boost-root.jam",
> "site-config.jam", "user-config.jam", "boost-build.jam", root/Jamfile, and
> subdir/Jamfile in that order.
>
> That would handle all kinds of possibilities for customization by end
> users.

Walking project hierarchy and printing all values of "project-help" should
be possible too. I still slightly prefer explicit extending of parent's help.
(Recall that 'user-config.jam' is project too).

> PS. Still on vacation on GMT+0, but departing in a few hours :-)

Hope you had a nice vacation! Where is that GMT+0 geneographically?

- Volodya

-- 
Vladimir Prus
http://vladimir_prus.blogspot.com
Boost.Build V2: http://boost.org/boost-build2