[CMake] Using add_subdirectory to manage project dependencies that aren't actually in a subdirectory

[Iosif Neitzke]

Why not just go one directory up?  Add /path/to/CMakeLists.txt
containing at least:

add_subdirectory(A)
add_subdirectory(B)

https://github.com/toomuchatonce/cmake-examples/blob/master/staticlibs-add_subdir/CMakeLists.txt

On Fri, Sep 18, 2015 at 5:42 PM, Joe <jtcacct at gmail.com> wrote:
> Hi.  I was hoping to get some guidance on if this is bad practice.  I am
> simply trying to find a way to manage internal dependencies of my project
> but with a file structure that is distributed.  It looks like this:
>
> /path/to/A
>
> /path/to/B
>
> B depends on A.  I cannot change this directory structure.  The solution we
> have chose is to create the following:
>
> /path/to/modules/FindA.cmake:
>
> ...
> if (NOT TARGET A)
>    set(PATH_TO_A ${CMAKE_CURRENT_LIST_DIR}../A)
>    add_subdirectory(${PATH_TO_A} ${PATH_TO_A}/build)
> endif()
> ...
>
> This way, A' CMakeLists is invoked and the library is compiled and built.
> Then in B's CMakeLists.txt:
>
> ...
> set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
>    ${CMAKE_CURRENT_LIST_DIR}/../modules)
>
> find_package(A)
> add_executable(main_B src/main_B.cpp)
> target_link_libraries(main_B A)
> ...
>
> Is this bad practice?  I tried to figure out find_package in CONFIG mode but
> every example I've found seems complicated and obtuse.  Thank you.
>
>
>
> --
>
> 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:
> http://public.kitware.com/mailman/listinfo/cmake