Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!quintus!ok
From: ok@quintus.uucp (Richard A. O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: const, volatile, etc [was Re: #defines with parameters]
Message-ID: <873@quintus.UUCP>
Date: 15 Dec 88 22:49:56 GMT
References: <674@quintus.UUCP> <117@halcdc.UUCP> <468@auspex.UUCP> <9016@smoke.BRL.MIL> <10919@ulysses.homer.nj.att.com> <1450@micomvax.UUCP> <369@aber-cs.UUCP> <9143@smoke.BRL.MIL> <377@aber-cs.UUCP>
Sender: news@quintus.UUCP
Reply-To: ok@quintus.UUCP (Richard A. O'Keefe)
Distribution: eunet,world
Organization: Quintus Computer Systems, Inc.
Lines: 16

In article <377@aber-cs.UUCP> pcg@cs.aber.ac.uk (Piercarlo Grandi) writes:
>This volatile argument is as old as programming; every PL/1
>programmer knows that many a compiler will generate buggy code when the
>optimizer is let loose on code with exception handlers.

>They do not think that that is a fault of the language, they rightly think
>that it is the compiler that is wrong, and they greatly resent having to use
>a compiler option to influence the semantics of a piece of code (ahhhh, if
>only PL/1 included volatile for variables, instead of only for procedures! :->).

(a) It's PL/I, not PL/1.
(b) PL/I *does* include "volatile" for variables.
    There are two pairs of attributes: IRREDUCIBLE/REDUCIBLE and
    ABNORMAL/NORMAL.  The default in PL/I is as in dpANS C: if you do not
    explicitly say otherwise the compiler will assume a variable is _not_
    "volatile".