Re: [jamboost] Re: Boost.Build and SCons

From: Pedro Ferreira (pedro.ferreira_at_[hidden])
Date: 2004-12-15 04:59:38

Em 14 Dec 2004, às 11:28, Vladimir Prus escreveu:

>
> Hi Pedro,
>
>> 1. Initially, bjam will invoke SCons at the lowest level (creating
>> SCons Nodes instead of bjam's targets).
> ........
>> My first feeling was that it was indeed the best way to proceed and I
>> implemented a prototype of 1.:
>>
>> 1. change build-system.jam to dump a Python map of all virtual-targets
>> and their relevant properties
>> 2. create a Python script that reads the map an creates the 
>> appropriate
>> SCons nodes
>> 3. map BB properties into SCons environment settings
>>
>> This works fine when using simple properties, such as <define>,
>> <include> and <linkflags>, which are readily supported by SCons
>> enviroments.
>> But, in order to map things like <optimization> or <debug-symbols>, 
>> you
>> need to know which compiler you are using.
>> And, there must be a mapping between BB target type and the 
>> appropriate
>> Environment method to call in order to create a target. And you must
>> choose env.StaticObject or env.SharedObject depending on the target
>> being a DLL or a LIB.
>
> I'd expect that we create very low-level SCons representation, where 
> each Node
> represent a file, and actions and variables are computed by 
> Boost.Build. That
> is, the settings that toolset.set-target-variables is passed over to 
> SCons
> together with the command lines used by toolsets.
>
> Why have another feature->variable translation if the existing one 
> works?

Sure. And that was the goal we had set initially. I just started 
experimenting to see where we had to go afterwards.

>> So, I got to the conclusion that we would be better off moving 
>> directly
>> to Python.
>
> It might be less terrible thing that it sounds, due to large number of 
> tests
> V2 has, but still will take unpredictable time. Of course, if somebody 
> can do
> it over weekend, that would be great.

:-) Not over a weekend but it's my firm belief that we'll get good 
feedback soon after we start.

Regards,

Pedro