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,afb4d45672b1e262 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.megapath.net!news.megapath.net.POSTED!not-for-mail NNTP-Posting-Date: Mon, 03 Apr 2006 20:23:18 -0500 From: "Randy Brukardt" Newsgroups: comp.lang.ada References: Subject: Re: Any way of persuading GNAT/GCC to implement a true overlay and not a pointer? Date: Mon, 3 Apr 2006 20:23:25 -0500 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: NNTP-Posting-Host: 64.32.209.38 X-Trace: sv3-3HUnvk9AYzup4+kyq7SH+CuoicyiPVBVORdmwOeq3QQNd6ICdsFXYSgPnGSKYw7iyA8WAKBFW61v3nJ!hz/AtbagCISnwWwW7ojRmJ4lvAs+aTBlVaXLWso0iAeGAhF4C/rkS1XsQTbbIgZWuvkICkkdRTRG X-Complaints-To: abuse@megapath.net X-DMCA-Complaints-To: abuse@megapath.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: g2news1.google.com comp.lang.ada:3714 Date: 2006-04-03T20:23:25-05:00 List-Id: "Doobs" wrote in message news:LIednWDbPNgXGbPZRVnysQ@pipex.net... > I was under the impression that code of the following form : > > X : ; > Y : ; > for Y'Address use X'Address; > > would result in an overlay in the resulting code. It does, semantically. >... Although this appears > semantially identical to an overlay as far as the progam is concerned it is > NOT identical as far as an external observer is concerned. I have a bit > packed record which I wanted to return as an array of longwords to pretty > dumb test equipment. ... I fail to understand why it would matter. If you have "dumb test equipment", it clearly knows nothing about Ada. So you are just looking at bare dumps of information; in that case, why not just use X and forget that Y exists? Treat Y as an artifact of the program, not a "real* entity. If the equiment is smart enough to know about Ada type information (or be told about Ada type information), then it must be smart enough to handle the indirection here and there should be no problem. In any case, your requirement is far out of the norm. Your best bet is to contact the vendor (AdaCore) in this case and get their advice. Yes, that means paying for support; but this is the kind of requirement that falls under custom support anyway. (Surely that would be our answer if you asked us how to make our compiler do this.) Expecting unusual requirements to be handled for free on important projects is just plain silly. Randy.