Re: [Boost-cmake] disabling particular external dependencies

Subject: Re: [Boost-cmake] disabling particular external dependencies
From: Sean Chittenden (sean_at_[hidden])
Date: 2009-11-06 16:28:01

>> I can populate the list of libs that I need by hand, but am looking  
>> for guidance on what's the right way forward.
>> Is there a correct way to use find_package(Boost...) with an  
>> installed 1.41.0 atm?  I notice Boost_VERSION is set as a string in  
>> BoostConfig.cmake but the older FindBoost.cmake that comes with  
>> cmake 2.6.4 is expecting an integer.  -sc
>
> Sorry about this...  you've turned up some bugs that I'm working on,  
> I've built an entire test harness for this stuff, I expect the  
> regression list to start dropping quickly.  But for now stay tuned.

To have 1.41 do the right thing, be sure to set Boost_FIND_COMPONENTS  
and it will populate Boost_LIBRARIES (when include()'ing  
BoostConfig.cmake):

set(Boost_FIND_COMPONENTS date_time program_options system thread  
unit_test_framework)
include("${CONTRIBOBJ}/share/boost-${WANT_BOOST_VERSION}/cmake/ 
BoostConfig.cmake")

> set(WANT_BOOST_LIBS date_time graph program_options regex signals  
> system thread unit_test_framework)
>
> foreach(boost_lib ${WANT_BOOST_LIBS})
>   set(Boost_LIBRARIES ${Boost_LIBRARIES} "boost_${boost_lib}-mt-d")
> endforeach(boost_lib ${WANT_BOOST_LIBS})

When it comes time for unit tests, however, you get the lovely:

> /opt/local/bin/g++-mp-4.3    -gdwarf-2 -Wno-deprecated -g -Wl,- 
> search_paths_first -headerpad_max_install_names -fPIC CMakeFiles/ 
> foo_unittests.dir/foo.cc.o CMakeFiles/foo_unittests.dir/foo_bar.cc.o  
> CMakeFiles/foo_unittests.dir/foo_baz.cc.o CMakeFiles/ 
> foo_unittests.dir/foo_bar_baz.cc.o  -o ../obj/contrib-Darwin-i386/ 
> bin/foo_unittests  -L/opt/local/lib -L/Users/sean/src/obj/contrib- 
> Darwin-i386/lib/boost-1.41.0 -lpthread -lboost_program_options-mt - 
> lboost_system-mt -lboost_thread-mt -lboost_unit_test_framework-mt

> Undefined symbols:
>   "_main", referenced from:
>       start in crt1.10.5.o
> ld: symbol(s) not found
> collect2: ld returned 1 exit status

The static library unit_test_framework has a main() function, however  
the .dylib/.so does not.  I haven't played around with this much to  
find out why yet, but thought I'd throw that out there.  The problem  
there came from a small change between versions:

<1.41.0  set(Boost_USE_STATIC_LIBS   ON)
=1.41.0  set(Boost_USE_STATIC   ON)

Any chance Boost_USE_STATIC_LIBS could set Boost_USE_STATIC and throw  
a depreciation warning?  :)  -sc

--
Sean Chittenden
sean_at_[hidden]