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,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,ec6f74e58e86b38b X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news4.google.com!feeder.news-service.com!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!gegeweb.org!aioe.org!not-for-mail From: =?iso-8859-15?Q?Yannick_Duch=EAne_=28Hibou57=29?= Newsgroups: comp.lang.ada Subject: Re: Lost in translation (with SPARK user rules) Date: Thu, 27 May 2010 21:18:10 +0200 Organization: Ada At Home Message-ID: References: <0466e131-cc80-4db4-b080-eec9aefcb1c7@z17g2000vbd.googlegroups.com> <4bfd2d05$0$27598$ba4acef3@reader.news.orange.fr> <1jo6gjejsy828$.e9dx6txqbazd$.dlg@40tude.net> <4bfd998c$0$2359$4d3efbfe@news.sover.net> <4bfebb3f$0$27571$ba4acef3@reader.news.orange.fr> NNTP-Posting-Host: VsdMw8HJ6uo7b6guDb/gnA.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Content-Transfer-Encoding: Quoted-Printable X-Complaints-To: abuse@aioe.org X-Notice: Filtered by postfilter v. 0.8.2 User-Agent: Opera Mail/10.53 (Win32) Xref: g2news2.google.com comp.lang.ada:12094 Date: 2010-05-27T21:18:10+02:00 List-Id: Le Thu, 27 May 2010 20:34:52 +0200, Pascal Obry a =E9c= rit: > Peter, > >> I do agree certainly that SPARK is not for everything. The code I'm = >> working on >> is (potentially) security sensitive so the extra effort of working wi= th = >> SPARK >> seems worthwhile. My test harness, on the other hand, is likely to be= = >> in full >> Ada. > > Just curious, why do you feel that you still need to write tests after= > having run successfully the SPARK proof checker? > > Pascal. Good question Pascal, May be because that's a tradition, may be because some inside voices tel= l = you you're bad if you don't run test, or may be due to the lack of = understanding that test are done when there is no way to prove anything = = (that is, tests would be a fall-back). Peter, I'm not telling that's you though, I'm just telling that testing = is = so much genetically inlaid in the computer culture, that doing without i= t, = would be somewhat frightening, just like the first time one learn to swi= m = or to ride a bicycle (waw, do I really have to stand up on this thing = which not even able to stand up by itself ?) But may be there is another reason : logic. That is a question I have in mind since I've recently discovered (well, = = really started with) SPARK : one may prove something, while he/she may n= ot = really know what he/she is proving. You may prove some specifications (I= = mean pre/post, not runtime error safety), but what if this specification= s = does not express what he/she supposed these expressed ? One component of the chain may still be a source of matters : the one fr= om = a though to a specification. I agree testing is a least a bit needed for that. However, this is not t= o = be driven as the other kind of testing, which is very different, I mean = = the one which is driven when nothing else can be done (or no body wanted= = to do something else). -- = There is even better than a pragma Assert: a SPARK --# check. --# check C and WhoKnowWhat and YouKnowWho; --# assert Ada; -- i.e. forget about previous premises which leads to conclusion -- and start with new conclusion as premise.