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-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,78b2880bc7e78e39 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-03-21 08:53:44 PST Path: supernews.google.com!sn-xit-02!supernews.com!news.gv.tsc.tdk.com!hub.org!hub.org!feed.textport.net!newsranger.com!www.newsranger.com!not-for-mail Newsgroups: comp.lang.ada From: Ted Dennison Sender: usenet@www.newsranger.com References: <98qumf$5sf$1@nh.pace.co.uk><98r4g1$7r1$1@nh.pace.co.uk><3ab1d090$1@pull.gecm.com><98t8la$rc$1@nh.pace.co.uk><3ab72c8f$1@pull.gecm.com><997pq4$i35$1@nh.pace.co.uk><3ab79ade$1@pull.gecm.com><998ctp$ond$1@nh.pace.co.uk> <998o2h$sa2$1@nh.pace.co.uk> <99ae0k$g0j$1@nh.pace.co.uk> Subject: Re: RISC Message-ID: Date: Wed, 21 Mar 2001 16:47:13 GMT NNTP-Posting-Host: 127.0.0.1 X-Complaints-To: abuse@newsranger.com X-Trace: www.newsranger.com 985193233 127.0.0.1 (Wed, 21 Mar 2001 11:47:13 EST) NNTP-Posting-Date: Wed, 21 Mar 2001 11:47:13 EST Organization: http://www.newsranger.com Xref: supernews.google.com comp.lang.ada:5969 Date: 2001-03-21T16:47:13+00:00 List-Id: In article <99ae0k$g0j$1@nh.pace.co.uk>, Marin David Condic says... > >Very true. This is why lots of mission critical systems *freeze* a version >of the compiler at some juncture in the project. Better the bugs you know >than to have something totally unexpected show up in a new release. But that isn't even sufficient to keep you safe from erronious code. Assuming that the generated code might be affected by how the compiler decides to optimize (a quite reasonable assumption), then your code could cease to work if any of the following happen: o You recompile with a different set of options. o You change a line of code somewhere in the entire system and recompile. and in some cases (notably the old DEC Ada compiler)... o You compile on a different machine. o You compile on the same machine, but with a different amount of free RAM (different set of background processes running at the time). You really should not *ever* use erronious code unless you have some kind of good assurance from your vendor that it will behave predictably (often the vendor docs will mention some such instances). I suppose having access to the sources of your compiler and checking it over yourself might count, but that would probably be more work than finding a better way. --- T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html home email - mailto:dennison@telepath.com