cpp/cmake/CopyToDir.cmake

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# CopyToDir.cmake

# This function is used to copy files to a directory and it will handle relative paths automatically.
function(copy_to_dir)
    set(INCLUDE_EXPORT_DR ${LIBRARY_INCLUDE_DIR} CACHE INTERNAL "Include export directory")
    math(EXPR file_path_length "${ARGC} - 1")
    list(SUBLIST ARGN 0 ${file_path_length} file_paths)
    list(GET ARGN ${file_path_length} parent)

    add_custom_command(
            OUTPUT copy_cmd_${parent}
            COMMAND ${CMAKE_COMMAND} -E echo Copying headers of ${parent}
    )

    foreach(file IN LISTS file_paths)
        get_filename_component(file_name ${file} NAME)
        get_filename_component(file_path ${file} PATH)
        string(REPLACE "${CMAKE_SOURCE_DIR}/src" "" relative_path "${file_path}")
        add_custom_command(
                OUTPUT copy_cmd_${parent} APPEND
                COMMAND ${CMAKE_COMMAND} -E make_directory ${INCLUDE_EXPORT_DR}/${relative_path}
                COMMAND ${CMAKE_COMMAND} -E copy_if_different ${file} ${INCLUDE_EXPORT_DR}/${relative_path}/${file_name}
        )
    endforeach()
    add_custom_target(
            copy_${parent} ALL
            DEPENDS copy_cmd_${parent}
    )
    add_dependencies(${parent} copy_${parent})
endfunction()