How to copy DLL files into the same folder as the executable using CMake?

Solution 1:

I'd use add_custom_command to achieve this along with cmake -E copy_if_different.... For full info run

cmake --help-command add_custom_command
cmake -E

So in your case, if you have the following directory structure:

/CMakeLists.txt
/src
/libs/test.dll

and your CMake target to which the command applies is MyTest, then you could add the following to your CMakeLists.txt:

add_custom_command(TARGET MyTest POST_BUILD        # Adds a post-build event to MyTest
    COMMAND ${CMAKE_COMMAND} -E copy_if_different  # which executes "cmake - E copy_if_different..."
        "${PROJECT_SOURCE_DIR}/libs/test.dll"      # <--this is in-file
        $<TARGET_FILE_DIR:MyTest>)                 # <--this is out-file path

If you just want the entire contents of the /libs/ directory copied, use cmake -E copy_directory:

add_custom_command(TARGET MyTest POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy_directory
        "${PROJECT_SOURCE_DIR}/libs"
        $<TARGET_FILE_DIR:MyTest>)

If you need to copy different dlls depending upon the configuration (Release, Debug, eg) then you could have these in subdirectories named with the corresponding configuration: /libs/Release, and /libs/Debug. You then need to inject the configuration type into the path to the dll in the add_custom_command call, like this:

add_custom_command(TARGET MyTest POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy_directory
        "${PROJECT_SOURCE_DIR}/libs/$<CONFIGURATION>"
        $<TARGET_FILE_DIR:MyTest>)

Solution 2:

I put these lines in my top-level CMakeLists.txt file. All the libraries and executables compiled by CMake will be placed in the top level of the build directory so that the executables can find the libraries and it is easy to run everything.

set (CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})

Note that this doesn't solve the OP's problem of copying precompiled binaries from the project's source directory.