On Sat, May 19, 2018 at 11:55 PM, Elvis Stansvik <elvis.stans...@orexplore.com> wrote: > 2018-05-19 21:49 GMT+02:00 Mateusz Loskot <mate...@loskot.net>: >> On 19 May 2018 at 15:00, Elvis Stansvik <elvis.stans...@orexplore.com> wrote: >>> I know this has been asked before, but I've never seen a really >>> authoritative answer. >>> >>> Say I have a simple single-library project. >>> >>> The advise I've seen is to not pass SHARED or STATIC to the >>> add_library(..), but instead let the user pass >>> -DBUILD_SHARED_LIBS:BOOL=ON/OFF to build the library as either shared >>> or static. >>> >>> That's fine, but leads to packagers having to do ugly things like e.g: >>> >>> https://salsa.debian.org/hle/dlib/blob/master/debian/rules >>> >>> That is, do two separate configure/build/install, in order to get both >>> a shared and static version. >> >> IMHO, there is nothing ugly in this approach. >> Not every system allows (or recomments) to generate both, >> static and shared, from the same object files. > > Alright. Yes I'm probably personally leaning towards just using the > recommended way, with a single add_library(..) and demand > reconfigure/rebuild/reinstall to get both variants. I was mostly > curious if you CMake pros on this list had some neat solution I hadn't > seen before. > > Note that I wasn't necessarily suggesting building shared + static > from the same set of object files (which is indeed not recommended, > e.g. think of -fPIC),
Static libraries should be compiled with -fPIC on all systems that support -fPIC. The reason for this is that you should not make assumptions about the final target of the static library. There is no reason it should be excluded from being linked into a shared library or a ASLR capable executable. On Anaconda Distribution, everything is compiled with -fPIC on Linux for this reason, and on macOS, -fPIC is the only option and Windows has always been PIC or at least for as long as I can remember. but just looking for best practices when having > CMake do the build of both libraries as part of the same build. > > Elvis > >> Why not view static vs shared as the similar to 32 vs 64 bit? >> >> Best regards, >> -- >> Mateusz Loskot, http://mateusz.loskot.net >> -- >> >> Powered by www.kitware.com >> >> Please keep messages on-topic and check the CMake FAQ at: >> http://www.cmake.org/Wiki/CMake_FAQ >> >> Kitware offers various services to support the CMake community. For more >> information on each offering, please visit: >> >> CMake Support: http://cmake.org/cmake/help/support.html >> CMake Consulting: http://cmake.org/cmake/help/consulting.html >> CMake Training Courses: http://cmake.org/cmake/help/training.html >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Follow this link to subscribe/unsubscribe: >> https://cmake.org/mailman/listinfo/cmake > -- > > Powered by www.kitware.com > > Please keep messages on-topic and check the CMake FAQ at: > http://www.cmake.org/Wiki/CMake_FAQ > > Kitware offers various services to support the CMake community. For more > information on each offering, please visit: > > CMake Support: http://cmake.org/cmake/help/support.html > CMake Consulting: http://cmake.org/cmake/help/consulting.html > CMake Training Courses: http://cmake.org/cmake/help/training.html > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Follow this link to subscribe/unsubscribe: > https://cmake.org/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: https://cmake.org/mailman/listinfo/cmake