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: 103376,87cdb3ab9d84f71c X-Google-Attributes: gid103376,public From: dewar@merv.cs.nyu.edu (Robert Dewar) Subject: Re: NRC Public Briefing on Ada Date: 1996/11/05 Message-ID: #1/1 X-Deja-AN: 194673825 references: <55eame$t1l@felix.seas.gwu.edu> <55k2qc$qoj@newsbf02.news.aol.com> <01bbca3c$b0579940$028371a5@dhoossr.iquest.com> <55mbt0$3q9@uuneo.neosoft.com> organization: New York University newsgroups: comp.lang.ada Date: 1996-11-05T00:00:00+00:00 List-Id: iBob Love said "This is pretty absurd. Simulators and mission planning tools are getting closer together all the time. The simulator uses the same information and mostly the same hardware, as the real vehicle." To emphasize this point, one of the really tough problems we faced with GNAT recently was a customer who was building a simulator and wanted to use EXACTLY THE SAME CODE, character for character, that was in the operational vehicle for the simulator. That's a reasonable demand, although given that different compilers for different languages (Ada 83 vs Ada 95) were involved, a little tough to meet. Turns out we had to add a couple of pragma Pack's and that was all (the VADS compiler lets a size clause do implicit packing, something that is contrary to the implementation advice in the Ada 95 RM, and something which NAT GNAT does not feel like emulating). Anyway, it took a bit of doing, but we got permission to add the pragma Pack.. In fact expecting quite this level of compatibility in a situation like this where the operational and simulation hardware are totally different is a bit extreme, but the idea of writing the operational software in language x and the corresponding simulator software in language y is totally nuts to me, for any possible choices of x and y!