Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!mit-eddie!genrad!decvax!ucbvax!MIT-MULTICS.ARPA!Schauble From: Schauble@MIT-MULTICS.ARPA (Paul Schauble) Newsgroups: mod.computers.vax Subject: Null arguments in VMS fortran Message-ID: <870102072445.474131@MIT-MULTICS.ARPA> Date: Fri, 2-Jan-87 02:24:00 EST Article-I.D.: MIT-MULT.870102072445.474131 Posted: Fri Jan 2 02:24:00 1987 Date-Received: Fri, 2-Jan-87 18:36:04 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 20 Approved: info-vax@sri-kl.arpa I have some fortran programs taken from a VAX to convert. These make use of null arguments in CALL statements, for example, CALL SUBR (A,,B) I understand that this produces a word of zeros in the generated argument list. What I don't understand is what this feature is used for. As I recall, page 0 of the process address space does not exist, so that references to small addresses produce some variety of memory protection fault. This would seem to be the fate of a fortran subroutine that attempts to use a null argument. Is there a language extension that would let it tell? Am I correct then in assuming that this feature requires that the routine being called must be written in another language and must be expecting use of this convention? Paul