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: 1014db,df854b5838c3e14 X-Google-Attributes: gid1014db,public X-Google-Thread: 103376,df854b5838c3e14 X-Google-Attributes: gid103376,public X-Google-Thread: 109fba,df854b5838c3e14 X-Google-Attributes: gid109fba,public From: Mike Stark Subject: Re: C/C++ knocks the crap out of Ada Date: 1996/02/19 Message-ID: <4gaa6l$8mk@post.gsfc.nasa.gov>#1/1 X-Deja-AN: 140089175 references: <4etcmm$lpd@nova.dimensional.com> <4f4ptt$a1c@newsbf02.news.aol.com> <4g1b7n$l5@mailhub.scitec.com.au> content-type: text/plain; charset=us-ascii organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA x-url: news:JSA.96Feb16135027@organon.com mime-version: 1.0 newsgroups: comp.lang.ada,comp.lang.c,comp.lang.c++ x-mailer: Mozilla 1.1N (Macintosh; I; 68K) Date: 1996-02-19T00:00:00+00:00 List-Id: jsa@organon.com (Jon S Anthony) wrote: >In article <4g1b7n$l5@mailhub.scitec.com.au> ramsesy@rd.scitec.com.au (Ramses Youhana) writes: > >> You'll be surprised how easily both junior (and senior) engineers can turn >> both C/C++ and Ada programs into spaghetti code. The language itself >> doesn't make for a quality system. > >Yes, but there are degrees of ease with which this can be done. I think >that was more to the point. > > >> Didn't NASA loose a satelite due to a bug in a piece of Ada code? > >I don't think so. I believe that the only confirmed case of a probe >loss due to software was a Venus probe which had Fortran code (the >problem was a "lexical" error concerning spaces not acting as lexical >separators). The recent Mars probe that "vanished" was (last I saw) >thought to have been lost due to a small rupture in one of the on board >tanks. This caused the ship to go into uncontrolled tumbling. I don't >know what it was programmed with. > >/Jon >-- >Jon Anthony >Organon Motives, Inc. >1 Williston Road, Suite 4 >Belmont, MA 02178 > >617.484.3383 >jsa@organon.com > Folks -- The mere fact that Ada (or any other language) is used for a satellite does not guarantee that the software is reliable enough -- there is far more to engineering flight qualified software. That being said, I would prefer a language that can use exception handling to recover from anomalies such as bit flips caused by cosmic rays, and that doesn't allow unrestricted address arithmetic to (potentially) store data into the code currently in memory. Ada isn't the only language designed for high reliability (Java and Eiffel leap to mind), but if I were a satellite project manager I would certainly prefer it to C or C++. Mike ----------------------------------------------------------------------- Michael Stark NASA/GSFC Phone: (301) 286-5048 Code 552 Fax: (301) 286-0245 Greenbelt, MD 20771 e-mail: michael.e.stark@gsfc.nasa.gov "I don't give them hell. I tell the truth and they THINK it's hell!" -- Harry S. Truman -----------------------------------------------------------------------