id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7344,Free properties not available in conditional rule,anonymous,Vladimir Prus,"Free properties are not propagated to common-properties2 rule in targets.jam file. Rationale behind this is to optimise caching of already created property-set objects (exactly as stated in rule common-properties, which contains the call).

However, this optimisation causes that free features are not passed e.g. to user-defined rules used for evaluation of <conditional> properties (see example below in the second code listing).

Therefore I would propose to drop this optimisation and propagate also free properties (see code listing below). The other possible solution would be to just pass free properties to the common-properties2 rule and thus make them available to the algorithm, but this will introduce another bug (property-set object from cache will be used even though it contains values created from different free properties).


== SOLUTION PROPOSAL ==


{{{
rule common-properties ( build-request requirements )
{
    local props = [ property-set.create
        [ $(requirements).base ]
        [ $(requirements).incidental ]
        [ $(requirements).free ]
    ] ;

    local key = .rp.$(build-request)-$(props) ;
    if ! $($(key))
    {           
        $(key) = [ common-properties2 $(build-request) $(props) ] ;        
    }        
    return $($(key)) ;
}
}}}


== BUG REPRODUCTION ==


{{{
import feature ;


feature.feature define-prefix : : free ;

rule define-target-os ( properties * )
{
  local define-prefix = [ feature.get-values define-prefix : $(properties) ] ;
  define-prefix ?= """" ;
  local target-os = [ feature.get-values target-os : $(properties) ] ;
  return <define>$(define-prefix)TARGET_OS_$(target-os:U) ;
}


project /root
  : requirements
      <define-prefix>FOOBAR_
      <conditional>@define-target-os
;


exe hello
 : #sources
     hello.cpp
 : #requirements
;
}}}

",Bugs,new,To Be Determined,build,Boost 1.52.0,Problem,,,