Re: [Boost-build] Named metatarget parameters

Subject: Re: [Boost-build] Named metatarget parameters
From: Vladimir Prus (ghost_at_[hidden])
Date: 2010-03-17 03:40:19

On Thursday 11 March 2010 20:21:20 Gevorg Voskanyan wrote:

> Spencer E. Olson wrote:
> > I wasn't going to chime in, but I had to reply to at least one of the previous 
> > posts.
> > 
> > Regardless of whether the language parsing could be a problem as Rene pointed 
> > out, the arg-type: value1 value2 thing just looks plain ugly and a lot 
> > different from what is used currently.  Personally, I like the suggestions 
> > that Johan is making, such that we would have the following (including the [] 
> > portion in the requirements):
> > 
> > lib program_options
> >     : parsers.cpp # By position
> >     : requirements
> >         <link>static
> >         [ target-builds has_long_long : "skipping boost.math long long" ]
> >     : usage-requirements <define>BOOST_ALL_NO_LIB=1
> >     : default-build
> >         <toolset>gcc:<variant>release
> >         <toolset>pgi:<variant>debug
> >     : description "Does something about dashes on command line"
> >     : license "BSL 1.0"
> >     ;
> > 
> > I really don't like the overuse of the ':' character.  The above looks a lot 
> > more like 'project' and is much easier to understand and use than either the 
> > current format or some of the other suggestions.  Furthermore, because we are 
> > not introducing a new concept for the ':' character, we don't add any more 
> > confusion especially when you might want to put a conditional as demonstrated 
> > above in the 'default-build' portion.
> > 
> > Spencer
> 
> 
> I want to second to everything Spencer has said above. Being consistent with 'project' would be 
> just great, as it would eliminate one more source of confusion and as such ease the learning 
> curve for newbies. Mixing styles (i.e. using [] when it is necessary and omitting otherwise) 
> looks fine to me as well, especially as the need to use brackets would probably not come up 
> very often anyway.

Thanks for the feedback! It looks like we settle on the following kind of syntax:

    lib boost_math_long
    : parsers.cpp # By position
    : requirements
    <link>static
    [ target-builds has_long_long : "skipping boost.math long long" ]
    ;

to be consistent with the 'project' (apparently, everybody's favourite!).

Now, I only have to update a couple dozen metatarget rules to handle this syntax ;-)

Thanks,

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