Re: [Boost-build] [bbv2] propagating requirements to libraries

From: Deane Yang (deane_yang_at_[hidden])
Date: 2007-04-04 14:11:47

Eric Niebler wrote:
> Konstantin Litvinenko wrote:
>> Hello, Eric!
>> You wrote  on Tue, 03 Apr 2007 12:13:26 -0700:
>>
>>  EN> This causes all of my tests to crash, because the tests are built with
>>  EN> _HAS_ITERATOR_DEBUGGING=0, and the unit test framework is not. What I
>>  EN> really need to do is build my *own* version of the unit test framework
>>  EN> with this define, and link to that. But I don't know how to get the
>>  EN> <define> requirement to propagate to the library.
>>
>>  EN> Can anybody tell me the magic incantation?
>>
>> Try this
>>
>> import feature ;
>>
>> feature.feature iterator_debugging : on off : composite propagated optional 
>> ;
>> feature.compose <iterator_debugging>off : <define>_HAS_ITERATOR_DEBUGGING=0 
>> ;
>>
>> project
>>      : requirements
>>        <library>/boost/test//boost_unit_test_framework
>>        <link>static
>>        # MSVC-8's iterator debugging causes some tests to run forever.
>>        <toolset>msvc-8.0:<iterator_debugging>off
>>      ;
>>
>> test-suite "accumulators"
>>      : [ run count.cpp ]
>>        [ run covariance.cpp ]
>> ...
>>      ;
> 
> 
> It works! You're a genius. And I see that puts the resulting lib in a 
> special iterator_debugging-off/ subdirectory, so other tests that don't 
> use this feature won't link to this special lib inadvertently. Very nice.
> 

I agree. This is a very important tip that will help avoid linking 
incompatible libraries together. The same problem caused me some major 
headaches in the past.