[question] Install dependency DLLs

[CrustyAuklet]

What is your question?

I have an application and a library, lets call them APP and LibA. LibA depends on OpenSLL built as a shared library and APP depends on LibA. Both APP and LibA are using Conan2 through the conan_provider.cmake file to keep the CMakeLists free from conan specific code.

APP uses CMake to create an installer. When I run cmake install the application and all DLLs should end up in the install directory. Using CMake I can gather the system DLLs needed and they install correctly. But I can't figure out how to install the needed OpenSSL DLLs (libssl-3.dll and libcrypto-3.dll).

Expectation

Install DLL dependencies using standard CMake. It would be great to not have to list the dependencies by name but I am ok doing that if needed.
Not sure but is this related to the new CMakeDeps2 generator? should I be using that?

Kind of Working

Combining some approaches I tried below I added to my CMakeLists.txt. This does require knowing the dependencies by name and use the LIB_BIN_DIRS_${CONFIG} variable that find_package seems to populate.

SET(MYLIB_RUNTIME_DEPS "${openssl_BIN_DIRS_RELEASE}")
configure_file(./install-runtime-deps.cmake.in "${PROJECT_BINARY_DIR}/install-runtime-deps.cmake" @ONLY)
install(SCRIPT "${PROJECT_BINARY_DIR}/install-runtime-deps.cmake")

in the configure file

file(GET_RUNTIME_DEPENDENCIES
     RESOLVED_DEPENDENCIES_VAR _FOUND_DEPS
     UNRESOLVED_DEPENDENCIES_VAR _MISSING_DEPS
     LIBRARIES @CMAKE_RUNTIME_OUTPUT_DIRECTORY@/@CMAKE_SHARED_LIBRARY_PREFIX@MyLib@CMAKE_SHARED_LIBRARY_SUFFIX@
     DIRECTORIES @openssl_BIN_DIRS_RELEASE@
     PRE_EXCLUDE_REGEXES
         [[api-ms-win-.*]]
         [[ext-ms-.*]]
         [[kernel32\.dll]]
         [[user32\.dll]]
         [[msvcrt.*\.dll]]
     POST_EXCLUDE_REGEXES
         [[.*[/\]system32[/\].*\.dll]]
)
message(STATUS "Resolved deps: ${_FOUND_DEPS}")
message(WARNING "Unresolved deps: ${_MISSING_DEPS}")
file(INSTALL ${_FOUND_DEPS} DESTINATION @CMAKE_INSTALL_BINDIR@)

This seems to work, but not the most concise. Is the variable openssl_BIN_DIRS_RELEASE that comes from CMakeDeps and find_package reliable and ok to use?

Other Attempts

CONAN_RUNTIME_LIB_DIRS

This variable seems to only be set in the toolchain generator, but the conan_provider.cmake uses CMakeDeps as far as I understand.

file(GET_RUNTIME_DEPENDENCIES ...)

install(CODE [=[
    file(GET_RUNTIME_DEPENDENCIES
        RESOLVED_DEPENDENCIES_VAR _FOUND_DEPS
        UNRESOLVED_DEPENDENCIES_VAR _MISSING_DEPS
        EXECUTABLES $<TARGET_FILE:APP>
        POST_EXCLUDE_REGEXES
            [[.*[/\]system32[/\].*\.dll]]
    )
    message(STATUS "Resolved deps: ${_FOUND_DEPS}")
    message(WARNING "Unresolved deps: ${_MISSING_DEPS}")
    file(INSTALL ${DAP_FOUND_DEPS} DESTINATION $<INSTALL_PREFIX>)
]=]
)

This correctly identifies the missing DLLs but does not find them, I see my message output as:

Unresolved deps: libcrypto-3.dll;libssl-3.dll

TARGET_RUNTIME_DLLS

Using the generator expression $<TARGET_RUNTIME_DLLS:APP> should list the DLLs needed by the target but the CMake code

add_custom_command(TARGET APP POST_BUILD
                   COMMAND ${CMAKE_COMMAND} -E copy -t $<TARGET_FILE_DIR:APP> $<TARGET_RUNTIME_DLLS:APP>
                   COMMAND_EXPAND_LISTS
)

results in no arguments to the copy ($<TARGET_RUNTIME_DLLS:APP> is empty).

Copy files in generate

There is an example in the docs that copies DLLs during the generate step. This works to get the DLLs in the build folder. From there I guess the CMakeLists could assume that the DLLs are in the build folder?

Have you read the CONTRIBUTING guide?

• I've read the CONTRIBUTING guide

[memsharded]

Hi @CrustyAuklet

Thanks for the feedback.

You are right, when using the conan_provider.cmake, the toolchain cannot be passed, because the invocation to Conan happens already from CMake. So with the CMakeToolchain and CMakeDeps generators, the CONAN_RUNTIME_LIB_DIRS is defined in the conan_toolchain.cmake after conan install, then it is too late.

The new CMakeConfigDeps generator, instead, can generate a conan_cmakedeps_paths.cmake that can be included, so it can be used from the conan_provider.cmake, and that file will contain the definition of CONAN_RUNTIME_LIB_DIRS. I had a branch with a proof of concept of this, I will resume it as soon as we move forward the CMakeConfigDeps generator out of incubating.

For a simple solution in the meantime, you might modify the conan_provider.cmake and add a --deployer=runtime_deploy to the conan install command, that will make a copy of the runtime of all dependencies into a local folder.

[CrustyAuklet]

Thanks @memsharded , looking forward to the new feature.

I added --deployer=runtime_deploy to my project by adding set(CONAN_INSTALL_ARGS "--build=missing --deployer=runtime_deploy" CACHE STRING "Command line arguments for conan install" FORCE) to the top of my root CMakeLists.txt.

Where should I expect to find the DLLs? I looked in my build folder and don't see anything.

[memsharded]

That is weird, the files should be right there in your folder.
You can add the --deployer-folder=myruntimefolder to explicitly define a folder name for the output.

Are you sure that your CIONAN_INSTALL_ARGS argument is being used defined that way?
Can you share the output of the execution? Thanks!

[CrustyAuklet]

I am poking at this little by little because of the holiday here, but this looks suspicious. The semi-colons are inserted like it's a CMake lists instead of spaces between arguments. I suspect this either needs to be 100% a list or all spaces. I will dig into the cmake function conan_install later

-- CMake-Conan: conan install E:/MyLib -of=E:/MyLib/out/build/msvc-x86-release/conan --profile:host=default;--profile:host=E:/MyLib/out/build/msvc-x86-release/conan_host_profile;--profile:build=default;-s;build_type=Release;--build=missing --deployer=runtime_deploy

if I run the command by hand in the terminal I see the DLLs and everything works as expected!

conan install E:/MyLib -of=E:/MyLib/out/build/msvc-x86-release/conan --profile:host=default --profile:host=E:/MyLib/out/build/msvc-x86-release/conan_host_profile --profile:build=default -s build_type=Release  --build=missing --deployer=runtime_deploy

[memsharded]

if I run the command by hand in the terminal I see the DLLs and everything works as expected!

Interesting, thanks for the feedback!

So it seems this would be mostly a discussion for cmake-conan integration, moving the ticket to that repo.