set(EXP_TREE "@CMAKE_CURRENT_SOURCE_DIR@/expected-tree")
set(ACTUAL_TREE "@CMAKE_INSTALL_PREFIX@")

file(GLOB_RECURSE exp_files RELATIVE "${EXP_TREE}" "${EXP_TREE}/*")
file(GLOB_RECURSE actual_files RELATIVE "${ACTUAL_TREE}" "${ACTUAL_TREE}/*")
list(SORT exp_files)
list(SORT actual_files)

if(NOT exp_files STREQUAL actual_files)
    foreach(f ${exp_files})
        list(FIND actual_files "${f}" result)
        if(result EQUAL -1)
            message(WARNING "${f} was expected, but not found")
        endif()
    endforeach()
    foreach(f ${actual_files})
        list(FIND exp_files "${f}" result)
        if(result EQUAL -1)
            message(WARNING "${f} was found, but not expected")
        endif()
    endforeach()
    message(FATAL_ERROR "Trees differ!")
endif()