Path: utzoo!mnetor!uunet!husc6!mailrus!nrl-cmf!ames!pasteur!ucbvax!ulysses!hector!jss
From: jss@hector.UUCP (Jerry Schwarz)
Newsgroups: comp.lang.c
Subject: Re: noalias, again
Message-ID: <10188@ulysses.homer.nj.att.com>
Date: 28 Mar 88 20:00:57 GMT
References: <7712@apple.Apple.Com> <7485@brl-smoke.ARPA> <10731@mimsy.UUCP> <7506@brl-smoke.ARPA>
Sender: netnews@ulysses.homer.nj.att.com
Reply-To: jss@hector (Jerry Schwarz)
Organization: AT&T Bell Labs, Murray Hill
Lines: 17

In article <7506@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>
>On the other hand, strcpy() between NON-OVERLAPPING portions of an
>array is supposed to be valid, so if the noalias wording doesn't
>agree with that, we'll have to fix it.

"Noalias" in the prototype of strcpy does not (and cannot) say one
way or another what is intended.  It simply says that whatever is
manipulated through one pointer shouldn't be manipulated through the
other. Only by an auxilliary description that describes the semantics
of strcpy can we be sure what is allowed.  In particular, I assume
the committee will endorse the rule that any non-overlapping areas
are ok, but overlapping areas aren't.

I remain completely opposed to "noalias".

Jerry Schwarz