set(range 1 2 3 4 5 6 7 8 9 10) set(aargs "") set(bargs "") foreach(n IN LISTS range) set(aval "${A${n}ARG}") set(bval "${B${n}ARG}") if(aval OR bval) list(APPEND aargs "\"${aval}\"") list(APPEND bargs "\"${bval}\"") endif() endforeach() if(NOT "${aargs}" STREQUAL "${bargs}") message(FATAL_ERROR "COMPARE_OPTIONS: \n\t${aargs} != \n\t${bargs}") endif()