How to find dll/so files in a CMake Superbuild

问题

I have set up cross-platform software project using CMake Superbuild, where dependencies are added and built using ExternalProject_Add. The project compiles on both Windows and Linux, but when I try to run the executable programs that are produced, it does not work because it fails to find dll/so files of dependencies. This is not surprising, as the dll/so files of external dependencies are not placed in the output directory(bin in visualization below).

One of the dependencies that are added using ExternalProject_Add is OpenCV. After OpenCv is built by the superbuild, I can find it using find_package(OpenCv). I can then reference libraries and include files by using the variables OpenCV_LIBS and OpenCV_INCLUDE_DIRS. However, there seems to be no variables that tell me where the dll/so files are located.

To further complicate it, it seems that the dll/so files end up in different folders when building on Linux and Windows. Here is simplified visualization of my project structure. Build/bin is where my executable programs and dll/so files that my project produces end up.

On Windows, the OpenCV dlls end up in the external_projects folder: external_projects/OpenCV-build/bin/Debug, wheras on Linux the .so files end up in external_projects/OpenCV-build/lib.

I guess I could for each external project check where the dll/so files end up, and copy them by using a combination of GLOB and if(WIN32) etc. But this doesn't seem ideal.

What is the proper way of doing this in a CMake superbuild, how do you make the dll/so files available so the executable programs can find them?

Update To clarify: There is a CMakeLists.txt file inside the CMake folder. This script calls Superbuild.cmake which (somewhat simplified) looks like this:

ExternalProject_Add(OpenCV ...) # Downloads source from github ExternalProject_Add(libtiff...)# Downloads source from gitlab ... ExternalProject_Add(myMainProject SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/.. # Adds CMakeLists.txt in root project folder DEPENDS ${myMainProjectDependencies} # OpenCV and libtiff ) This results in the dependencies being built before myMainProject is built.

回答1:

You can setup an install target with CMake, and configure it to place your binaries and headers in the correct location:

# bin
if (${BUILD_SHARED_LIBS})
    install(
        FILES
            $<TARGET_FILE:my_target>
        DESTINATION
            bin
        COMPONENT
            runtime
    )
endif()

# lib
install(
    TARGETS
        my_target
    DESTINATION
        lib
    COMPONENT
        devel
)

# include
install(
    FILES
        Header1.hpp
        Header2.hpp
    DESTINATION
        include/my_target
    COMPONENT
        devel
)

Now you can install the binaries, import libraries, and headers to your CMAKE_INSTALL_PREFIX path, using something like ninja install (assuming you're using Ninja as the generator for CMake).

来源：https://stackoverflow.com/questions/58933367/how-to-find-dll-so-files-in-a-cmake-superbuild

标签

c++

Linux

windows

cmake

cross-platform