Installation instructions

[dlfcn-win32]

Installation instructions

[traversaro]

I think the "recommended way" really depends on which build system you use in your project, and how you handle other 3rd-party dependencies.

If you use CMake, you can install dlfcn-win32 in a specific prefix using CMAKE_INSTALL_PREFIX , and then find it using the instructions documented in https://github.com/dlfcn-win32/dlfcn-win32#using-cmake .
I think it should be possible to also consume it via the FetchContent module, but that is still a work in progress ( https://github.com/dlfcn-win32/dlfcn-win32#using-cmake ).

If instead you typically vendor (i.e. copy in your project) also other dependencies, you can just grab the dlfcn.c and dlfcn.h files and include them in your project. To comply to the LGPL license of the project and avoid the need to license under the LGPL all your project, I suggest to make sure that you compile the dlfcn.c in a standalone shared library.

Yet another alternative is using vcpkg. A port of dlfcn-win32 for vcpkg is available in the main vcpkg repo: https://github.com/Microsoft/vcpkg/tree/master/ports/dlfcn-win32 .

[cipher1024]

So far so good. I followed the instruction for cmake and I added a call to vcpkg in my appveyor script. cmake doesn't seem to be finding dlfcn-win32. How do I encode the path to dlfcn-win32 into my cmake file?

[Lukacms]

Hello, did you found any solution ? I'm stuck on the same problem and I don't have Windows on my laptop so I'm testing with Github Actions, which is not ideal. I used FetchContent to install it, but it doesn't find the package, with or without find_package(dlfcn-win32 REQUIRED). Below is my CMake:

project(r-type-utils)

# standard version cpp
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_EXTENSIONS OFF)

# change library prefix to none
set(CMAKE_SHARED_LIBRARY_PREFIX "")
set(CMAKE_STATIC_LIBRARY_PREFIX "")

if (WIN32)
    include(FetchContent)
    FetchContent_Declare(
        dlfcn-win32
        GIT_REPOSITORY "https://github.com/dlfcn-win32/dlfcn-win32.git"
        GIT_TAG "v1.4.1"
        SYSTEM
    )
    FetchContent_MakeAvailable(dlfcn-win32)
endif()

# only add the interface library
add_library(r-type-utils INTERFACE)

# properties
set_property(TARGET r-type-utils PROPERTY CXX_STANDARD 20)
set_property(TARGET r-type-utils PROPERTY CXX_STANDARD_REQUIRED ON)
if (WIN32)
    find_package(dlfcn-win32 REQUIRED)
    target_include_directories(r-type-utils INTERFACE ${CMAKE_BINARY_DIR}/_deps/dlfcn-win32-src/src)
    target_link_libraries(r-type-utils INTERFACE dlfcn-win32::dl)
endif()

[traversaro]

If you included the library via FetchContent, the dlfcn-win32::dl target should be available after you call FetchContent_MakeAvailable(dlfcn-win32). If this is not working, there is a bug on dlfcn-win32 side. Furthermore, include directory should be already handled by the target, so you should not need target_include_directories(r-type-utils INTERFACE ${CMAKE_BINARY_DIR}/_deps/dlfcn-win32-src/src). Can you remove find_package and target_include_directories and try again?

[traversaro]

So far so good. I followed the instruction for cmake and I added a call to vcpkg in my appveyor script. cmake doesn't seem to be finding dlfcn-win32. How do I encode the path to dlfcn-win32 into my cmake file?

Sorry, this is a really old question, but I missed it. If you installed a library via vcpkg, to find it you need to add find_package(dlfcn-win32) in your CMakeLists.txt, and call your cmake by passing the vcpkg toolchain, see https://learn.microsoft.com/en-us/vcpkg/users/buildsystems/cmake-integration#cmake_toolchain_file for more details.

[Lukacms]

If you included the library via FetchContent, the dlfcn-win32::dl target should be available after you call FetchContent_MakeAvailable(dlfcn-win32). If this is not working, there is a bug on dlfcn-win32 side. Furthermore, include directory should be already handled by the target, so you should not need target_include_directories(r-type-utils INTERFACE ${CMAKE_BINARY_DIR}/_deps/dlfcn-win32-src/src). Can you remove find_package and target_include_directories and try again?

Thank you for your answer ! I did as you said but it did not compile, I put the log below:

[traversaro]

You are right, there is something missing on our side (that issue is actually tracked in #49). As a temporary workaround, you can just change target_link_libraries(r-type-utils INTERFACE dlfcn-win32::dl) to target_link_libraries(r-type-utils INTERFACE dl) and it should work fine (I guess).