How to copy contents of a directory into build directory after make with CMake?

You can use add_custom_command.

Say your target is called MyTarget, then you can do this:

add_custom_command(TARGET MyTarget PRE_BUILD
                   COMMAND ${CMAKE_COMMAND} -E copy_directory
                       ${CMAKE_SOURCE_DIR}/config/ $<TARGET_FILE_DIR:MyTarget>)

This executes every time you build MyTarget and copies the contents of "/config" into the directory where the target exe/lib will end up.

As Mark Lakata points out in a comment below, replacing PRE_BUILD with POST_BUILD in the add_custom_command ensures that copying will only happen if the build succeeds.

Explanation

• ${CMAKE_COMMAND} is the path to CMake
• -E makes CMake run commands instead of building
• copy_directory is a Command-Line Tool
• config is the directory (that falls under the root of the project) who's contents will be copied into the build target
• $<TARGET_FILE_DIR:MyTarget> is a generator expression, described in the add_custom_command documentation.

In addition to the top answer,

To copy the directory itself instead of the contents, you can add /${FOLDER_NAME} to the end of the second parameter.

Like this:

add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
                   COMMAND ${CMAKE_COMMAND} -E copy_directory
                       ${CMAKE_SOURCE_DIR}/config $<TARGET_FILE_DIR:${PROJECT_NAME}>/config)

CMake supports a shell type file copy. This link should be helpful for you - How to copy directory from source tree to binary tree?

Use symbolic links

CMake enables symbolic links via create_symlink:

add_custom_command(TARGET ${CMAKE_PROJECT_NAME} PRE_BUILD
                   COMMAND ${CMAKE_COMMAND} -E create_symlink
                   ${CMAKE_SOURCE_DIR}/config $<TARGET_FILE_DIR:${PROJECT_NAME}>/config)

It ensures that when you make a change to the files in the directory, build folder would subsequently be updated.