+$ IF (F$EXTRACT( 2, 1, POINTER_SIZE) .EQS. "=")
+$ THEN
+$! Explicit user choice: "64" or "64=ARGV".
+$ IF (POINTER_SIZE .EQS. "64=") THEN POINTER_SIZE = "64"
+$ ELSE
+$ SET NOON
+$ DEFINE /USER_MODE SYS$OUTPUT NL:
+$ DEFINE /USER_MODE SYS$ERROR NL:
+$ CC /NOLIST /NOOBJECT /POINTER_SIZE=64=ARGV NL:
+$ IF ($STATUS .AND. %X0FFF0000) .EQ. %X00030000
+$ THEN
+$ ! If we got here, it means DCL complained like this:
+$ ! %DCL-W-NOVALU, value not allowed - remove value specification
+$ ! \64=\
+$ !
+$ ! If the compiler was run, logicals defined in /USER would
+$ ! have been deassigned automatically. However, when DCL
+$ ! complains, they aren't, so we do it here (it might be
+$ ! unnecessary, but just in case there will be another error
+$ ! message further on that we don't want to miss)
+$ DEASSIGN /USER_MODE SYS$ERROR
+$ DEASSIGN /USER_MODE SYS$OUTPUT
+$ ELSE
+$ POINTER_SIZE = POINTER_SIZE + "=ARGV"
+$ ENDIF
+$ SET ON
+$ ENDIF
+$ POINTER_SIZE = " /POINTER_SIZE=''POINTER_SIZE'"
+$!