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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,a3ca574fc2007430 X-Google-Attributes: gid103376,public X-Google-Thread: 115aec,f41f1f25333fa601 X-Google-Attributes: gid115aec,public From: Chris Hills Subject: Re: Ada and Automotive Industry Date: 1996/12/01 Message-ID: #1/1 X-Deja-AN: 201705015 distribution: world x-nntp-posting-host: phaedsys.demon.co.uk references: <55ea3g$m1j@newsbf02.news.aol.com> <3280DA96.15FB@hso.link.com> organization: Phaedrus Systems mime-version: 1.0 newsgroups: comp.lang.ada,comp.realtime Date: 1996-12-01T00:00:00+00:00 List-Id: In article , Richard Riehle writes >On 27 Nov 1996, Robert Dewar wrote: > > > Now, for the Ada plug. I know of at least one software developer that > is re-engineering their 8051-based product to a different processor, > one that supports Ada, with plans to use Ada as its development > language on that new processor -- for safety reasons. And this is > a commercial developer with no, underscore NO, connection to the > Department of Defense. I am ammussed by the comment "for saftey reasons" ADA is no safer than any other language. It is only safer in theroy. It depends on the standard of the compilers and tools etc. I believe that at the current time there are nearly 2000 requests for clarification on the ADA standard. This is 2000 places where implimentors of tools are not sure what the standard means or have dissagreed over implimentation. Therefore no two ADA compilers are guaranteed to produce the same output. I was once told to use Modula 2 because it was "safe" It turned out that the compiler suite had been written in Intel assembler (supposedly a very unsafe language) and was full of bugs! In the end we used a Borland C compiler as there were more tools available to check the code and (due to sheer weight of users in the world) we were failry certain we knew of all the problems (bugs) with the compiler. We could not find another (successful) user of the Mod2 compiler we had much less one who had exercised it to the level we intended to use it. So no matter how *theoretically* safe a language is supposed to be in practice it is irrelevant if it is not practically safe. C can be a very safe language if one uses a good tool set in a sensible manner. Incorrect use of any language will cause problems. It was Ada on the Ariane 5 rocket that crashed in the summer. Not directly the fault of Ada but as I under stand it. It was partly because some one had deliberatly got round the strict ADA type checking. Yes ADA is theoretically strongly typed but if, to use it for real work, one must dissable this it makes it no better than C. Actually it is worse because peolpe have this false sence of security that if it copmpiles in ADA it must be safe.... The question is not is it a Theoretically safe language but is thew implimentation of the language accurate and it the tool set good, it's user understood and above all correctly used. NB: I am using C in an area more important than just "safty critical" money is involved.... What a world we live in :-( Regards Chris /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\/\ Chris Hills,Tamworth Staffs /\/\/\/\/\/ /\/\/\/\/\/\/\/\/\ B77 5PG England /\/\/\/\/\/\/\/\ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/