From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,c6acbb9f2027b8c9,start
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!postnews.google.com!g43g2000cwa.googlegroups.com!not-for-mail
From: "REH" <spamjunk@stny.rr.com>
Newsgroups: comp.lang.ada
Subject: volatile vs aliased
Date: 5 Oct 2005 08:22:02 -0700
Organization: http://groups.google.com
Message-ID: <1128525722.605730.281980@g43g2000cwa.googlegroups.com>
NNTP-Posting-Host: 192.91.173.36
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
X-Trace: posting.google.com 1128525727 30696 127.0.0.1 (5 Oct 2005 15:22:07
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Wed, 5 Oct 2005 15:22:07 +0000 (UTC)
User-Agent: G2/0.2
X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
 rv:1.7.12) Gecko/20050915,gzip(gfe),gzip(gfe)
Complaints-To: groups-abuse@google.com
Injection-Info: g43g2000cwa.googlegroups.com; posting-host=192.91.173.36;
   posting-account=lnUIyw0AAACoRB2fMF2SFTIilm8F10q2
Xref: g2news1.google.com comp.lang.ada:5410
Date: 2005-10-05T08:22:02-07:00
List-Id: <comp.lang.ada>

I'm converting some code written for Gnat to compile with Apex.  The
software has bindings to C functions (OS calls).  Some of these take
System.Address as parameters.  Apex complains about the variables used
in these calls (via 'Address) because they not volatile or aliased (or
imported, exported, etc.).  My question is: which should I use?  Is
there any difference whether a variable is volatile or aliased?

I am assuming the compiler is concerned about the variable possibly
being changed in the call (which, of course, is true).  Is there a way
to satisfy the compiler without stopping optimizations of the variable
after the call, or do I need to use a second variable to do this?