Recursive list of LINK_LIBRARIES in CMake

Question

I am trying to acquire a list of the absolute paths to all libraries linked to a specific target in CMake for use in a call to add_custom_command. However,

Answer 1

Recursively traversing LINK_LIBRARY property is possible.

Here is a get_link_libraries() that does that, however it does not handle all cases (e.g. libraries not being a target, not imported libraries).

function(get_link_libraries OUTPUT_LIST TARGET)
    get_target_property(IMPORTED ${TARGET} IMPORTED)
    list(APPEND VISITED_TARGETS ${TARGET})
    if (IMPORTED)
        get_target_property(LIBS ${TARGET} INTERFACE_LINK_LIBRARIES)
    else()
        get_target_property(LIBS ${TARGET} LINK_LIBRARIES)
    endif()
    set(LIB_FILES "")
    foreach(LIB ${LIBS})
        if (TARGET ${LIB})
            list(FIND VISITED_TARGETS ${LIB} VISITED)
            if (${VISITED} EQUAL -1)
                get_target_property(LIB_FILE ${LIB} LOCATION)
                get_link_libraries(LINK_LIB_FILES ${LIB})
                list(APPEND LIB_FILES ${LIB_FILE} ${LINK_LIB_FILES})
            endif()
        endif()
    endforeach()
    set(VISITED_TARGETS ${VISITED_TARGETS} PARENT_SCOPE)
    set(${OUTPUT_LIST} ${LIB_FILES} PARENT_SCOPE)
endfunction()