if (NOT DEFINED VALID_LANG)
  set (VALID_LANG C)
endif()
if (NOT DEFINED INVALID_LANG)
  set (INVALID_LANG CXX)
endif()

if (NOT actual_stdout MATCHES "BADFLAG_${VALID_LANG}_LANG")
  set (RunCMake_TEST_FAILED "Not found expected 'BADFLAG_${VALID_LANG}_LANG'.")
endif()
if (actual_stdout MATCHES "BADFLAG_${INVALID_LANG}_LANG")
  if (RunCMake_TEST_FAILED)
    string (APPEND RunCMake_TEST_FAILED "\n")
  endif()
  string (APPEND RunCMake_TEST_FAILED "Found unexpected 'BADFLAG_${INVALID_LANG}_LANG'.")
endif()