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,c9d5fc258548b22a X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!proxad.net!feeder1-2.proxad.net!news.in2p3.fr!in2p3.fr!news.ecp.fr!news.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: How do I write directly to a memory address? Date: Wed, 2 Mar 2011 20:42:25 -0600 Organization: Jacob Sparre Andersen Research & Innovation Message-ID: References: <67063a5b-f588-45ea-bf22-ca4ba0196ee6@l11g2000yqb.googlegroups.com> <31c357bd-c8dc-4583-a454-86d9c579e5f4@m13g2000yqb.googlegroups.com> <05a3673e-fb97-449c-94ed-1139eb085c32@x1g2000yqb.googlegroups.com> <4d4c232a$0$28967$882e7ee2@usenet-news.net> <4D4D6506.50909@obry.net> <4d50095f$0$22393$882e7ee2@usenet-news.net> <4d6d56c4$0$11509$882e7ee2@usenet-news.net> <16u9ka51wbukr$.1fj2sb73j9rv6.dlg@40tude.net> <4d6d627b$0$11509$882e7ee2@usenet-news.net> <74986d0a-0d5b-4396-8c77-adff72e870a2@d26g2000prn.googlegroups.com> <4d6eafc7$0$17913$a8266bb1@postbox2.readnews.com> <4d6eb309$0$17913$a8266bb1@postbox2.readnews.com> <1179af04-08fa-4c3e-91f5-8e7dbe455600@k38g2000vbn.googlegroups.com> <4d6eea4d$0$14912$882e7ee2@usenet-news.net> NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net X-Trace: munin.nbi.dk 1299120148 31274 69.95.181.76 (3 Mar 2011 02:42:28 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Thu, 3 Mar 2011 02:42:28 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931 X-RFC2646: Format=Flowed; Response Xref: g2news2.google.com comp.lang.ada:18726 Date: 2011-03-02T20:42:25-06:00 List-Id: "Hyman Rosen" wrote in message news:4d6eea4d$0$14912$882e7ee2@usenet-news.net... > On 3/2/2011 4:34 PM, KK6GM wrote: >> Why would you assume any positive opportunity cost at all (as opposed >> to a negative opportunity cost, that is, a savings)? Why would you >> assume that the entire software development/maintenance cycle is >> cheaper when using tools and methods that produce more bugs? > > I assume that taking extra time to fix all known errors and to test > very thoroughly for unknown errors will incur large costs in time, > money, and opportunity. That assumption depends very much on the techniques used. I very much doubt that "testing very thoroughly" would have much effect on software quality, but it surely would have the effects on time and opportunity cost that you are mentioning. OTOH, if your compiler and toolset somehow eliminated most of the debugging phase (by detecting errors early during the "bugging" phase of program development), one would imagine that your costs could go way down. Note that I think the above is a goal more than something that is completely achievable. I tend to think that there will always be a few logic errors that are too hard to detect without taking too much up-front effort. (The attempt of tools like SPARK to catch everything has a point of diminishing returns.) But we surely can do better than Ada does. To the extent that this is possible, I already do this in my own projects. I hardly ever use a debugger on any of our programs (the exception is malfunctioning compiler output; as a compiler writer, one has to figure out where the generated code goes wrong, and that usually requires single-stepping), and testing is mostly limited to existing regression suites. The Ada compiler detects most problems up-front; the self-checking built-into the programs detects most of the rest. What's left would be unlikely to be detected by testing anyway (especially after clean regression test runs). Randy.