set(METHODS null) if(WITH_METHOD_XSALSA20_POLY1305) list(APPEND METHODS xsalsa20_poly1305) endif(WITH_METHOD_XSALSA20_POLY1305) if(WITH_METHOD_AES128_GCM) list(APPEND METHODS aes128_gcm) endif(WITH_METHOD_AES128_GCM) set(METHOD_OBJECTS "") foreach(method ${METHODS}) add_subdirectory(${method}) list(APPEND METHOD_OBJECTS $) endforeach(method) set(METHOD_OBJECTS "${METHOD_OBJECTS}" PARENT_SCOPE)