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-Language: ENGLISH,CP1252 X-Google-Thread: 103376,d6f7b92fd11ab291 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-07-16 10:15:34 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!arclight.uoregon.edu!wn13feed!wn12feed!worldnet.att.net!204.127.198.203!attbi_feed3!attbi_feed4!attbi.com!rwcrnsc54.POSTED!not-for-mail Message-ID: <3F158832.1040206@attbi.com> From: "Robert I. Eachus" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Crosspost: Help wanted from comp.compilers References: <1058275843.720814@master.nyc.kbcfp.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit NNTP-Posting-Host: 66.31.71.243 X-Complaints-To: abuse@comcast.net X-Trace: rwcrnsc54 1058375730 66.31.71.243 (Wed, 16 Jul 2003 17:15:30 GMT) NNTP-Posting-Date: Wed, 16 Jul 2003 17:15:30 GMT Organization: Comcast Online Date: Wed, 16 Jul 2003 17:15:30 GMT Xref: archiver1.google.com comp.lang.ada:40343 Date: 2003-07-16T17:15:30+00:00 List-Id: Hyman Rosen wrote: > Here's some evidence. I have no idea about its quality. > Given the unfortunate lack of a worldwide web in the 80s, > it's not clear where to search for more data. Looking at > some of the links below, I think a big problem was that > many of the systems forced all dependents of a file to be > recompiled when the file was recompiled, regardless of > whether the source had changed. If you understood Ada, you would understand that all of the "evidence" you supplied confirmes what we have said. The issue going into the Ada 9X process was that tools that tried to short-cut the Ada recompilation rules were tried--and they were much worse than the problem. > I believe this was one > reason that GNAT decided to go with a source-based model > for its library. Hoo, boy. That is good. Do you really understand how the GNAT "source based" model works? Everytime you compile a unit the specification for every package/unit withed by that unit is recompiled. Every time you modify a subunit the library unit, or a library unit with subunits, the library unit and all of its subunits needs to be recompiled. In other words, the GNAT model does lots more recompilation, not less. The benefit is that the overhead of compiling specifications is kept very low, so the recompilation from source is faster than saving an intermediate state and restoring it. -- Robert I. Eachus �In an ally, considerations of house, clan, planet, race are insignificant beside two prime questions, which are: 1. Can he shoot? 2. Will he aim at your enemy?� -- from the Laiden novels by Sharon Lee and Steve Miller.