Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: notesfiles Path: utzoo!watmath!clyde!floyd!harpo!decvax!ucbvax!ucbcad!ucbesvax.turner From: turner@ucbesvax.UUCP Newsgroups: net.flame Subject: Re: berkeley cretins Message-ID: <2900057@ucbesvax.UUCP> Date: Fri, 17-Feb-84 20:36:00 EST Article-I.D.: ucbesvax.2900057 Posted: Fri Feb 17 20:36:00 1984 Date-Received: Wed, 29-Feb-84 11:22:33 EST References: <4344@amd70.UUCP> Organization: UC Berkeley, EE/SESM Lines: 23 Nf-ID: #R:amd70:-434400:ucbesvax:2900057:000:1271 Nf-From: ucbesvax!turner Feb 25 17:36:00 1984 > /***** ucbesvax:net.flame / amd70!phil / 12:49 am Feb 25, 1984*/ > Has anyone ever told Berkeley that referencing the contents of a NULL > pointer does not always yield 0? > I know, this is a dead horse I'm beating. But damn, how many times do > I have to get bitten by this?????? Much of Berkeley's Franz Lisp was predicated on the ability to read out a zero from (cons *) NULL. Keith Sklower was rather peeved that we (at Dual Systems, when I was there) were unable to rearrange the memory map of our systems to Franz's convenience. (But he ported it anyway.) This is the only software I know of where this feature of VAXen was knowingly incorporated in the design. Phil will continue to be bitten by the dead horse he is beating here, simply because the "read 0 from location 0" is usually a bug in the code where it crops up. It's just that it you never trip over it on VAXen, so those bugs must wait for a different machine on which to manifest themselves. The code for string routines has not, to my knowledge, been adjusted. (E.g., strlen ((char *) 0) returns zero, without complaint AND WITHOUT CHECKING FOR A NULL ARGUMENT. That's just stupid.) But other cases will have be taken care of as they come up. --- Michael Turner (ucbvax!ucbesvax.turner)