Re: [Boost-build] How to use configuration files (site-config.jam and user-config.jam)?

Subject: Re: [Boost-build] How to use configuration files (site-config.jam and user-config.jam)?
From: Vladimir Prus (ghost_at_[hidden])
Date: 2009-08-29 07:26:12

On Thursday 06 August 2009 Boris Schaeling wrote:

> Does anyone use site-config.jam and/or user-config.jam? And how do you use  
> them? The problem I see is that you must add a "project xy" line to those  
> configuration files if you want to refer to targets from Jamfiles.  
> Whatever name you use all projects to be built must refer to the same  
> project id. It seems like it only makes sense to use the "using" rule  
> which doesn't need to be referenced explicitly? But if a project of mine  
> depends on a preinstalled library it would be nice of course if the  
> project can rely on site-config.jam or user-config.jam to define a target  
> to find the library. But this increases coupling between those  
> configuration files and my project. Do others simply use conditional  
> properties or the "conditional" rule in Jamfiles instead of relying on  
> configuration files?

Boris,

sorry for not getting to your earlier. I am not 100% sure about your question.
What coupling do you have in mind? 

It seems to me that it might be reasonable to pre-assign ids of 'user-config'
to user-config.jam without requiring explicit 'project user-config' in there.
It also seems reasonable to add some way of target inheritance, so you can
define

        searched-lib expat : .... ;

and then define 

        searched-lib ICU : ... ;

in project-config.jam and then every Jamfile could refer to expat or
ICU without specifying exactly what config file the target is defined in.

But, I am not at all sure those ideas address your concerns above. Could
you clarify?

- Volodya