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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,9b7d3a51d0d8b6ee X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news1.google.com!news.glorb.com!news2!wn13feed!worldnet.att.net!bgtnsc04-news.ops.worldnet.att.net.POSTED!53ab2750!not-for-mail Newsgroups: comp.lang.ada From: anon@anon.org (anon) Subject: Re: Compiler quality (was: Extending discriminant types) Reply-To: no to spamers (No@email.given.org) References: <20081115101632.5f98c596@cube.tz.axivion.com> <20081122011825.5354d1c1@cube.tz.axivion.com> <6691d418-5ce8-4584-8a09-3eb6bbc6d17f@v13g2000yqm.googlegroups.com> X-Newsreader: IBM NewsReader/2 2.0 Message-ID: Date: Mon, 24 Nov 2008 23:33:09 GMT NNTP-Posting-Host: 12.64.198.174 X-Complaints-To: abuse@worldnet.att.net X-Trace: bgtnsc04-news.ops.worldnet.att.net 1227569589 12.64.198.174 (Mon, 24 Nov 2008 23:33:09 GMT) NNTP-Posting-Date: Mon, 24 Nov 2008 23:33:09 GMT Organization: AT&T Worldnet Xref: g2news2.google.com comp.lang.ada:3748 Date: 2008-11-24T23:33:09+00:00 List-Id: As I stated to G.B. The "Base" was a concept in 83, and the usage was illegal in 83. See previous post. You also forget that Adacore has 100s may be even 1,000,000s of simple files they use for syntax checking for each Ada specifications. That can trap all syntax type of errors. And that group of files grows yearly, if not daily. But the way your statements sounds, you think the group of programmers at Adacore are lazy and allow bugs to pop up! I disagree with that of thinking! As for testing, you might have been correct back in the 1950s to the early 90s or if one uses other languages, such as C. But in using Ada with its finite set of strict syntax rules the number of test require to test the complete system is cut down to a more manageable level. And in today world it has become financial feasible for programmers to write and employ a group of programs to generate every combination of finite test for each of Ada rules and use a group of computers in parallel or multi-tasking to test every rule. In that way the concept of releasing an Ada compiler with a syntax BUG goes way down to almost zero for a company like Adacore, because the nature and usage of Ada in the real world, it has too. Even Microsoft, with it 1000s of BUGs in its OSs and apps has very few BUGs in its compilers and link editors. And a few Microsoft compilers are even are clarified as BUG free. Also even here, in "comp.lang.ada". There has been a number of posters that have stated they found a BUG or ask if this or that was a BUG. Most of those are logic or code generation type of errors, which this group shows that the error is not a compiler BUG. Even the syntax errors that are report here are shown by a number of regularly poster to be the fault of the programmer. So, the concept of BUGs is kind of outdated, unless you have too many programmer that are not working in tandem, that are not using a testing library. And one reason is that most programmers reuse the old "syntax parsing" routines in the updated program, only changing the code to insert the new statements. Like inserting the rules for handling a "union" statement and or other new statements in the Ada 95 syntax routine which update that syntax routine to handle the Ada 2005 specs. Then the programmers writes and adds the a set of new testing programs to the testing libraries. But sometime adding new code does introduce a logic error into the existing syntax parser. but that not a syntax BUG it a logical programmer error. And in Adacore the testing libraries are used to find and help correct the logic error before Adacore ever releases the next version of this compiler or package. An example of this type of logical error was listed here a few months back when someone stated that the "pragma Unreferenced" was not working, but on the previous compiler it was. So, someone logical turn off the compiler usages of that statement. But that person forgot to turn it back on when they finish modifying the compiler. And that's a logic mistake not a BUG and if the person would of, used a testing library after they finish the modications of the compiler they would have found that mistake before they packaged and release the code. And in the next generation of compiler, programs will construct the new compilers Testing is going on for this type of program now at schools and companies around the world, now. And in this compiler the concept of a syntax BUG will not exist at all. Even today one can construct such a partition that can create an Ada 2005 compiler which contain no BUGs in the syntax parsing routine. But how many people want to create that program which put x number of people out of work, including themselves. Now, this does not mean there are not BUGS, it just that they are becoming more of an hardware error, something that a program should be aware of but is hard to program for. As for professors not reporting, well as any person that has attended a college knows professor are too busy. It a wonder how they get anything done. This is one of the minor reason that the education system needs a complete overhaul. In <6691d418-5ce8-4584-8a09-3eb6bbc6d17f@v13g2000yqm.googlegroups.com>, Ludovic Brenta writes: >On Nov 23, 5:06 am, a...@anon.org (anon) wrote: >> What I am saying is that ALL BUG have been seen and reported by now for the >> GNAT-3.xx compilers, because of the volume of users and the amount of time >> that GNAT 3.xx series has been around. > >Like I said i my earlier post, this is wrong, as has just been proven >when we discovered a previously inknown bug in GNAT 3.15p just a >couple of days ago. The bug is that GNAT 3.15p accepts T'Base for non- >scalar T, in the default (Ada 95) mode. Even 100 years from now, if a >single person still uses GNAT 3.15p, it will be possible for them to >discover a previously unknown bug. > >Even an infinite amount of testing cannot prove a program to be bug- >free; it can only uncover an infinite amount of bugs. If you want to >prove a program correct, you must use formal methods, not testing. > >> Also, professors may or may not call >> Adacore if they find a BUG, but they normally note the error for future >> reference. > >I certainly hope professors (or any other user) don't keep their >records secret but instead report the bugs publicly, either in the >Debian bug tracking system (for GNAT 3.15p) or the GCC bugzilla (for >later versions). > >> And that until 1997, all Ada compiler including the GNAT-3.xx series were >> under the control of the US's DOD and the RM and only the RM. All newer >> compilers are not under such strong arm control or limitation, rather that's >> the US gov't or the direct rules of the RM. So, you may see a more relax view >> on applying the RM, which mean that newer compiler nay have this and others >> types of an error, not found in the GNAT 3.xx series. > >No, there is no "more relaxed view of the RM". The one thing that is >more relaxed is the trademark control over the name "Ada". All >versions of GNAT, in fact, undergo a constantly growing suite of tests >that includes and extends the ACATS. Every bug ever fixed has an >associated test to ensure the bug is never reintroduced. Of course, >bugs that are not yet fixed do not yet have such a test. > >[...] >> Plus, the complete Ada 2005 specification compiler aka GNAT 2008, has only >> been around a few months and has yet to be fully tested by the Ada community >> which can take years. > >Correct but that does not make GNAT 3.15p bug-free. > >> As for GNAT 5.01 and GNAT Pro 6.01, well they were not written under the >> DOD and the RM only control. And they have not been around 10 to 14 years >> yet, for someone to say that 5.01 or 6.01 have been fully checked. > >Like I said, even if you would use, say, GNAT Pro 5.01 for an infinite >amount of time, you could discover and correct an infinite number of >bugs and never be sure that the program is bug-free. > >That's what first year CS students ought to learn, anyway. > >-- >Ludovic Brenta.