Re: [jamboost] Default build change?

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-30 04:08:50

Jabber.org seems to have just gone down.

Vladimir Prus <ghost_at_[hidden]> writes:

> I'm somewhat uncomfortable with current "default build" semantics.
> First, we allow several alternatives for a main target.
>
> exe foo : foo.cpp foo_gcc.cpp : <toolset>gcc ;
> exe foo : foo.cpp foo_borland.cpp : <toolset>borland ;
>
> Both of them can declare default build, but if those default build
> are different, the whole system will break. Default build should
> be at least assigned to *main target*, but not *alternative*. I've no
> suggestions for UI, though.
>
> Another problem was discovered just now. Jamfile reads
>
> project
> : default-build <uses>qt
> ;
>
> build-project main ;
> build-project lib1 ;
>
> Clearly, if I run "bjam" the effect should be the same as if I've explicitly
> run it with "bjam uses=qt". That's not the case: the "default-build" setting
> is inherited by targets in "main" and "lib1" and take effect only when those
> targets are generated. In particular, if "lib1/lib1" is used by "main/hello",
> then "lib1/lib1" will be build without "<uses>qt".

I can't tell whether <uses>qt is supposed to be a requirement or just
a default-build setting. If the latter, I'm not sure I see a problem.

-- 
David Abrahams
dave_at_[hidden] * http://www.boost-consulting.com
Boost support, enhancements, training, and commercial distribution