Hi Michael > So, the options are: > > - use -whole-archive as you do now > - make the Kernel library shared > - link the dlopen'ed libraries against Kernel
Thanks very much - I understand. I think I will keep the -whole-archive method. However, now I'm worried about how I link in the Python library: /usr/bin/c++ -O3 -DNDEBUG -Wall -m64 -o myProj -rdynamic -Wl,-whole-archive Kernel/libKernel.a -Wl,-no-whole-archive -ldl -lpython2.4 The dlopen'ed libraries may use the Python library. I guess I could include it in the -whole-archive part, but perhaps it would be better to link each shared library against Python. Would you agree? Sorry that I am now off topic w.r.t cmake. By the way, I think I am pretty much there with changing our build system from manually coded makefiles to cmake. I like cmake! Thanks for all your help in getting there. The support on this list is excellent. Best regards David > -----Original Message----- > From: Michael Wild [mailto:them...@gmail.com] > Sent: 30 September 2010 12:20 > To: David Aldrich > Cc: cmake@cmake.org > Subject: Re: [CMake] How to specify -fpic ? > > > On 30. Sep, 2010, at 13:05 , David Aldrich wrote: > > > Hi > > > > Ok, by following the link to the wiki suggested by Michael Loose, I used: > > > > target_link_libraries( myProj -Wl,-whole-archive Kernel > > -Wl,-no-whole-archive) > > > > This has fixed my problem. The executable links and runs correctly. > > > > My link command is now: > > > > /usr/bin/c++ -O3 -DNDEBUG -Wall -m64 -Wl,--export-dynamic -o myProj - > Wl,-whole-archive Kernel/libKernel.a -Wl,-no-whole-archive -ldl -lpython2.4 > > > > I don't need portability so I think this is ok. > > > > Michael Wild wrote: > > > >> The -whole-archive flag is pretty useless with executables (unless, > >> you plan to use it as a library too, but that is outlandish). > >> --export-dynamic may be also necessary, if your dlopen'ed libraries > >> use symbols in your executable. > > > > So my concern is now: am I being 'outlandish' ? The dlopen'ed libraries do > use functions in libKernel.a that is linked to the executable. Is this > outlandish? Is there a better way? > > The "outlandish" referred to using an executable also as a library, so you're > fine :-) But I think I found the reason for why you need this -whole-archive > flag: Since your executable doesn't use all of the functions in the Kernel > library, the linker throws them away. This results in your dlopen'ed > functions to fail. > > So, the options are: > > - use -whole-archive as you do now > - make the Kernel library shared > - link the dlopen'ed libraries against Kernel > > Michael > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
