Re: [Boost-build] Question concerning conditional requirements

From: Vladimir Prus (ghost_at_[hidden])
Date: 2008-04-08 13:25:12

On Tuesday 08 April 2008 04:37:33 Mat Marcus wrote:
> Some of my projects make use of boost build conditionals. In
> particular. I make use of the Intel Thread Building Blocks Library. I
> build my libraries under msvc and darwin. The (stable) version of the
> Intel TBB is supported under msvc, and under darwin address-model=64,
> but not under darwin address-model=32. To account for this state of
> affairs I currently define a feature that tracks which tells whether
> the atomics from the Intel TBB library is available for a particular
> build. E.g.
> 
> #none doesn't mean no atomics--it means non-named value for the atomics feaure
> feature atomics : none tbb : composite ;
> #if change the next line then need to make parallel changes inside the
> body of use-atomics
> feature.compose <atomics>tbb : <include>../intel_tbb_libraries/include
> <define>ADOBE_ATOMICS ;
> feature.compose <atomics>none : ;
> 
> rule use-atomics ( properties * )
> {
>   local result ;
>   if ( ! ( <toolset>darwin in $(properties) ) ) ||
>    ( ( <address-model>64 in $(properties) ) ) ||
>    ( ( <architecture>x86 in $(properties) ) )  {
> 	 if ( <toolset>gcc in $(properties) && ( os<NT> || os<cygwin> in
> properties ) ) {
>      } else {
> # need to copy the <include> and <define> items here...bjam does not
> propagate them through
> # the dependent usage_requirements below otherwise
>           result += <atomics>tbb
> <include>../intel_tbb_libraries/include <define>ADOBE_ATOMICS ;
>      }
>   }
>   return $(result) ;
> }
> 
> My top level project requirements in tree1/Jamfile.v2 include a
> reference to this conditional:
> # ...
>   :  default-build
>     <link>static
>     <threading>multi
>     <conditional>@use-atomics
> 
> This seems to work as expected within the tree1. But now I introduce a
> second tree2 that depends on tree1. I'd like the conditional from
> tree1 to be usable in tree2. In particular, tree2 depends on libs in
> tree1 and I'd like to be able to use the conditional in the usage
> requirements for all libs in tree1. I've not been able to succeed. Can
> someone please advise me on how to arrange for tree1 libraries'
> conditional usage requirements to be available in tree2?

Can you clarify if you want code in tree2 to be able to use the 'use-atomics'
rule, or you want the effect of that rule to be always automatically
to be propagated, or something else?

- Volodya