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,e646052dc594401f 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!feeder.news-service.com!novso.com!npeer.de.kpn-eurorings.net!npeer-ng0.de.kpn-eurorings.net!newsfeed.arcor.de!newsspool4.arcor-online.net!news.arcor.de.POSTED!not-for-mail Date: Tue, 29 Jun 2010 22:49:25 +0200 From: Georg Bauhaus User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.4) Gecko/20100608 Thunderbird/3.1 MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Strategies with SPARK which does not support exceptions References: <93966134-a285-41c5-a7f6-8c59151718a7@k39g2000yqb.googlegroups.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Message-ID: <4c2a5c56$0$6988$9b4e6d93@newsspool4.arcor-online.net> Organization: Arcor NNTP-Posting-Date: 29 Jun 2010 22:49:26 CEST NNTP-Posting-Host: ec8972c7.newsspool4.arcor-online.net X-Trace: DXC=N<^oe`;iA7]mG86`U=_nC_4IUKBP8GT\nTPCY\c7>ejVX?>\Wga9^b?ZiV\VRIT@6i_ X-Complaints-To: usenet-abuse@arcor.de Xref: g2news2.google.com comp.lang.ada:12972 Date: 2010-06-29T22:49:26+02:00 List-Id: On 6/29/10 10:05 PM, Randy Brukardt wrote: > Result codes are dangerous, as ignoring of result codes is one of the major > problems in programming, and the resulting bugs are very, very hard to find. > (That's because of the difficulty of finding errors of omission.) > > Perhaps you are too young to remember, but early versions of Windows (3.0, > 3.1) had a reputation for being unstable and crashing often. But the > problems were mostly not with Windows but rather with programs that tended > to ignore the error returns from the Windows API. The result code situation in Windows 6.0 (Vista) seems even worse today, even inside Windows OS software. The example is this: When a file in NTFS is encrypted (green in explorer) and an existing program tries to open it (not knowing that it might be encrypted), the system returns "Access Denied". MS says that they don't have the OS return a more descriptive code because they know that many old programs will start failing and behave erratically: the old programs are not prepared to handle return codes that did not exist when the program was written. I Learned this when trying to install driver files extracted from a recent official ZIP archive by Linksys/Cisco, using Windows's own driver installation program. The files had ended up encrypted in the file system. Windows's standard installation stops with "Access Denied" ... Georg