Re: [jamboost] BB4

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-01-05 09:27:49

David Abrahams wrote:
> Hi Volodya,

Hi Dave,

> Every time I go to look at addressing BB4, I get confused.
> 
> Needd to implement new version of the "flags" rule. 
> Generators ids 
> 
> Where can I read about "generator IDs"?

Generator id is the first parameter to class generator constructors.
The idea is that whenever you create a new generate, you give it
an id via ctor. This was it's possible to refer to the generator
using more convenient name than "object_at_....".

> will be used to denote generator, to which flags apply. 
> 
> What does it mean that flags will apply to a generator? Is the idea
> simply to limit the "on target" variable assignments to the products
> of that generator?

Kind of. Generator id has a second function. It names a rule which is
used to actually set up build action. E.g. gcc.link generator has
associated gcc.link rule. (In fact, gcc.link *rule* is empty, there's
only gcc.link *action*, but that's detail).

I meant that if you say that flags apply to gcc.link, that the variable
assingment will be only done for that rule, but not for gcc.compile, for example.

> Before calling user-supplied rule, 
> 
> What user-supplied rule? The one which implements the generator's
> action?

Yes.

> generator will set target variables accordingly.
> 
> Also, I don't know how to reach this link mentioned in BB4 anymore:
> 
> news://news.gmane.org:119/[e-mail] 

Hmm... I get to it simply by clicking in Mozilla... Can Outlook open
news article by URL?

HTH,
Volodya

P.S. BTW, there's now a long row of holidays in Russia. I had a week of them 
already, and there will be two more: 6th and 7th. I'll be online as usual 
after that (and will resume Boost.Build hacking as well).