Re: [jamboost] Re: Need help

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-05-27 04:22:56

Hi Konstantin,

> VP> Yes. The problem is rather simple. If you have
>
> Maybe so, maybe not :)

:-)

[...]
> All that you saying works as expect but .... What if I have three
> targets lib tmp, lib foo, exe bar.
> lib foo depends on lib tmp, and exe bar depends lib foo. If I add
>
> <dependency>@/boost/date_time/boost_date_time
>
> to lib tmp, than lib foo will build with boost/date_time defines. But

Are you sure that "lib foo" will build with boost/date_time define. You must 
have meant "lib tmp" --- you did not arrive to "lib foo" yet.

> when I add to lib foo either <dependency> or <library> on lib tmp, lib foo
> builds without boost/date_time defines. I don't want to add
> <dependency>@/boost/date_time to lib foo explicitly. What am I doing wrong
> ?

IOW, you have 

exe bar <- lib foo <- lib tmp

The "tmp" lib uses boost/date_time, so it should have 
<dependency>@/boost/date_time/boost_date_time in requirements

But, it also wants all libraries/exes which use it to link to the same 
library. So, it must have <library>@/boost/date_time/boost_date_time in
usage requirements.

Here's Jamfile which can illustrate my point:

lib foo : foo.cpp : <dependency>../libs/date_time/build/boost_date_time
: : <library>../libs/date_time/build/boost_date_time ;

lib bar : bar.cpp : : : <library>foo ;

exe hello : hello.cpp bar ;

Here, everything will be compiled with proper includes. I realize that 
specifying one thing twice is a bit inconvenient, but let's make sure 
basic semantic works OK before adding convenience.

> VP> I've wrote a document which describe all this some time ago, but it
> VP> never ended in docs :-(
>
> I have found nothing about <dependency> in boost_build_v2.html form
> cvs. Did I miss something?

Do, you did not. It only present in 
http://article.gmane.org/gmane.comp.lib.boost.build/2323/

That's what I meant by "never ended in docs". 

Actually, part of my plan for M4 is to rename <dependency> to <uses>, and I'm 
also going to document it --- or maybe the entire build process.

- Volodya