So I guess in order to include the object-files from a third party static library, the only way would be to first extract it's object-files and then combine them?
On Fri, Sep 21, 2018 at 12:34 PM Deniz Bahadir <dbaha...@benocs.com> wrote: > Am 21.09.2018 um 18:38 schrieb Ke Gao: > > Hi David, > > > > It didn't give me error info. It can produce the final static library, > > but the contents of third party static libraries are not included. > > Some clarification regarding STATIC and OBJECT library targets and how > they interact with each other using `target_link_libraries`: > > > A STATIC library target A can be linked (via `target_link_libraries`) to > another STATIC library target B. > > `target_link_libraries(A STATIC PUBLIC B)` > > However, the resulting library file libB does not contain the > information (aka object-files) of libA. > Instead, CMake makes sure to link both static library files libB and > libA when e.g. creating an executable exeC1 using target C1 which just > links (via `target_link_libraries`) to target B. > > `target_link_libraries(C1 EXECUTABLE PUBLIC B)` > > (Instead of an executable exeC1 you could have created a shared library > libC1 instead. The behavior is the same.) > > > If you instead want to create a combined, single STATIC library libC2, > which contains the object-files archived in both static library files > libA and libB created from targets A and B, then you somehow need to > extract the archived object-files from libA and libB. I am not sure if > CMake provides a (simple) way to do this. > > > > For OBJECT libraries the behavior is like this: > > > An OBJECT library target X can be linked (via `target_link_libraries`) > to another OBJECT library target Y. > > `target_link_libraries(Y OBJECT PUBLIC X)` > > This, however, only transports the usage-requirements > (preprocessor-defines, include-paths etc.) from X to Y. The object-files > of X are in no way referenced by Y. > > So, if you then create a STATIC target Z1 that links (via > `target_link_libraries`) to Y,... > > `target_link_libraries(Z1 STATIC PUBLIC Y)` > > ... Z1 will reference/contain the usage-requirements of X and Y and the > object-files of Y, but not the object-files of X. (The static library > file libZ1 resulting from Z1 will contain the object-libraries of Y but > not of X.) > > > What you should do instead is not to link the OBJECT targets X and Y > together but instead only link them (explicitly) to the STATIC target Z2: > > `target_link_libraries(Z2 STATIC PUBLIC Y X)` > > Z2 then references the usage-requirements as-well-as object-files of > both OBJECT targets X and Y and the resulting static library file libZ2 > will then contain the object-files of both library targets, X and Y. > > > > > > Also, sorry for the mistake I have made in my previous email. Deniz is > > right, the keyword "PUBLIC" should be used in target_link_librarie(). > > > > Thanks > > You're welcome. > > Deniz > > > > > > On Fri, Sep 21, 2018 at 10:06 AM David Jobet <djo...@tower-research.com > > <mailto:djo...@tower-research.com>> wrote: > > > > Hello, > > > > glad that could help you. > > For your newer problem, you don't describe them, so it's tough to > know > > what kind of problems you're facing. > > Maybe a small example of your CMakeLists.txt + a capture of the error > > cmake gives you could help ? > > > > David > > On Fri, Sep 21, 2018 at 4:52 PM Ke Gao <ke.gao...@gmail.com > > <mailto:ke.gao...@gmail.com>> wrote: > > > > > > Thank you all for the help. > > > > > > I finally use a way quite similar to David's first approach. I > > first generate all sub-projects into object libraries using > > add_library(lib1 OBJECT SOURCES). Then in the final library, I use > > add_library(single_static_lib STATIC SOURCES) and > > target_link_libraries( single_static_lib lib1 lib2 ...). Note that I > > didn't use " $<TARGET_OBJECTS:lib1>" in the final "add_library" and > > also didn't use "PUBLIC" keyword in the final > > "target_link_libraries". It works on CMake v3.12.2 and gives me a > > single static lib which combines all the objs I want. > > > > > > But currently I still have problems of further combining third > > party static libraries into the final generated static > > single_static_lib. Can anybody provide a solution for this? > > > > > > Thank you very much. > > > > > > Ke > > > > > > On Fri, Sep 21, 2018 at 6:15 AM Deniz Bahadir > > <dbaha...@benocs.com <mailto:dbaha...@benocs.com>> wrote: > > >> > > >> Am 21.09.2018 um 09:33 schrieb David Jobet: > > >> > Hello, > > >> > > > >> > I had a similar issue lately and wanted to "pack" several > > static libs > > >> > into a dynamic one. (Not even talking about an INTERFACE lib > > since I > > >> > really wanted that .so) > > >> > I made it work with 3 different solutions, none of them being > > "clean" > > >> > from my point of view. > > >> > > > >> > 1- OBJECT libs on sub projects : add_library(lib1 OBJECT > > SOURCES) and > > >> > for the single static lib : add_library(single_static_lib > STATIC > > >> > $<TARGET_OBJECTS:lib1> ...) > > >> > Problem I faced : since OBJECT libs do not support > > >> > target_link_libraries(), I had to remove the existing one and > move > > >> > them instead to the target_include_directories() using > generators. > > >> > > >> This is no longer true. Since CMake 3.12 `target_link_libraries` > > fully > > >> supports OBJECT libraries. You just need to pay attention to the > > special > > >> case of linking an OBJECT library with keyword "PUBLIC". > > (Object-files > > >> are always private and inherited object-files are therefore never > > >> further inherited. See: > > >> > > > https://cmake.org/cmake/help/v3.12/command/target_link_libraries.html#linking-object-libraries > ) > > >> > > >> > e.g : target_include_directories(lib1 PUBLIC > > >> > $<TARGET_PROPERTY:another_lib,INCLUDE_DIRECTORIES>) > > >> > Because I had a dependency to a protobuf generated lib, I also > > had to > > >> > add manual add_dependencies to respect proper build order. > > >> > Not clean at all > > >> > > > >> > 2- add_library(mysharedlib STATIC CMakeLists.txt) > > >> > target_linked_libraries(mysharedlib PUBLIC lib1 ...) > > >> > Maybe the cleanest way I found. > > >> > The trick with CMakeLists.txt is that add_library needs at > > least one > > >> > source file. You can put any kind of files you want. > > CMakeLists.txt is > > >> > not compilable, so no extra compilation step, no need for > > dummy empty > > >> > source file and add_library is happy. > > >> > It did not work in my case because of problems related to how > > our .so > > >> > are used/generated. (problems at runtime with duplicated > > symbols in > > >> > protobufs) > > >> > > > >> > 3- a variation around 1 > > >> > instead of defining OBJECT libs, define a variable holding all > the > > >> > sources for lib1, another for lib2, ... > > >> > then just do add_library(mysharedlib STATIC ${SOURCES_FOR_lib1} > > >> > ${SOURCES_FOR_lib2}) > > >> > It works a little bit like 1) but does not have any of its > > problems > > >> > (target_link, add_dependencies, generators, ...) > > >> > It has new problems of its own though : if your libs live in > > different > > >> > subfolders, the variables might not be visible from your > > >> > add_library(mysharedlib...) call. > > >> > To work around that, you can use PARENT_SCOPE (not sure if > > that works > > >> > accross several levels), or includes (defines those variables > into > > >> > separate files living in each subfolders and include them in > the > > >> > parent CMakeLists). > > >> > > > >> > Hope this helps (and I'd be happy to know of other ways) > > >> > > > >> > David > > >> > On Thu, Sep 20, 2018 at 5:45 PM Ke Gao <ke.gao...@gmail.com > > <mailto:ke.gao...@gmail.com>> wrote: > > >> >> > > >> >> Hi, > > >> >> > > >> >> I have a project which includes many sub-projects. Each > > sub-project generates a static library. In the main project, I want > > to combine the generated objs, generated static libraries from other > > sub-projects, and some other third party static libraries together > > into a single static library. Is there an elegant way to do this, or > > maybe an existing function? > > >> >> > > >> >> Thank you very much. > > >> >> > > >> >> -- > > >> >> > > > > .............................................................................................................................................. > > >> >> Ke Gao > > >> > > >> > > >> Hope that information was of value, > > >> Deniz > > >> > > >> -- > > >> > > >> Powered by www.kitware.com <http://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 > > > > > > > > > > > > -- > > > > > > > .............................................................................................................................................. > > > Ke Gao > > -- > > > > Powered by www.kitware.com <http://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 > > > > > > > > -- > > > .............................................................................................................................................. > > Ke Gao > > > > > -- > > 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 > -- .............................................................................................................................................. Ke Gao
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