Progress on issue 578618: Leave jamfile modules for user.

From: Vladimir Prus (ghost_at_[hidden])
Date: 2002-07-08 09:04:45

Hello,
I'm now working to move all the Boost.Build data from the namespace of the 
modules used to Jamfiles. The motivation is to leave a clean namespace where 
user can do whatever he likes. 

I've nearly done with this part, but it's gonna be a large commit, so I'm 
asking for comments. I've decided to leave exactly two things in the jamfile 
modules. First is "__attributes__" variable, which keeps an instance of 
"project-attributes" class. Second is the convernience method 
"__attribute__", which allows to write

local p = <some jamfile module> ;
local requirements = [ $(p).__attribute__ requirements ] ;

instead of

local p = <some jamfile module> ;
local attr = [ modules.peek $(p) : __attributes__ ] ;
local requirements [ $(attr).get requirements ] ;

I think this amount of namespace pollution is perfectly acceptable. Also, 
getting attributes of a project is quite easy. Is this arrangement is fine 
for everybody, I'll commit the change.

Second, this issue involves some changes to project root handling.

1. Maybe, we should move all project-root related data into separate object, 
so that proejct root module namespace be clean as well.

2. We'd need to make the "use-project" rule available in project root 
namespace. (I'll document that rule in the user docs soon. You can refer to 
the thread starting with 
http://groups.yahoo.com/group/jamboost/message/1320 meanwhile)

3. We'd need to import non-local rules from project root module into jamfile 
modules.

For me, it seems like a number of changes involving project-root.jam. Rene, 
do you have any spare time to work on this and/or discuss #1. Actually #1 is 
the most complex thing here, I think.

- Volodya