* Compiler implementation of speciallized needs annexes. @ 1999-02-24 0:00 Robert T. Sagris 1999-02-24 0:00 ` Tucker Taft 1999-02-25 0:00 ` dewar 0 siblings, 2 replies; 12+ messages in thread From: Robert T. Sagris @ 1999-02-24 0:00 UTC (permalink / raw) I was wondering why only GNAT implements all of the specialized needs annex's. All of the other vendors I looked into implement A, B as they are required. C and D are also generally implemented by everyone. Rational also implements G. Is this do to a lack of customer demand for these features or is it something else? I was just wondering Robbi Sagris ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-24 0:00 Compiler implementation of speciallized needs annexes Robert T. Sagris @ 1999-02-24 0:00 ` Tucker Taft 1999-02-24 0:00 ` Samuel T. Harris 1999-02-25 0:00 ` JP Thornley 1999-02-25 0:00 ` dewar 1 sibling, 2 replies; 12+ messages in thread From: Tucker Taft @ 1999-02-24 0:00 UTC (permalink / raw) Robert T. Sagris wrote: > > I was wondering why only GNAT implements all of the specialized needs > annex's. All of the other vendors I looked into implement A, B > as they are required. C and D are also generally implemented by > everyone. Rational also implements G. > > Is this do to a lack of customer demand for these features or is it > something else? Annexes C and D provide functionality in the real-time and system programming domain, which almost all user's of cross-compilers need. The other annexes are more "specialized," and as such, a critical mass of demand hasn't yet built up for them sufficient to entice other vendors to implement them. However, with the increasing interest in distributed component-based systems, even among the real-time crowd, I would expect at least the distributed annex to become more widely implemented. On the other hand, Ada/Corba is a viable alternative (e.g. ORBExpress/Ada from Objective Interface Systems), so that may have reduced the pressure for the distributed annex. I would also suspect that the safety-critical annex will be or is already supported by a number of vendors, even if they haven't validated against the Annex H tests. > > I was just wondering > > Robbi Sagris -- -Tucker Taft stt@averstar.com http://www.averstar.com/~stt/ Technical Director, Distributed IT Solutions (www.averstar.com/tools) AverStar (formerly Intermetrics, Inc.) Burlington, MA USA ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-24 0:00 ` Tucker Taft @ 1999-02-24 0:00 ` Samuel T. Harris 1999-02-25 0:00 ` robert_dewar 1999-02-25 0:00 ` JP Thornley 1 sibling, 1 reply; 12+ messages in thread From: Samuel T. Harris @ 1999-02-24 0:00 UTC (permalink / raw) Tucker Taft wrote: > > Annexes C and D provide functionality in the real-time and > system programming domain, which almost all user's of cross-compilers > need. The other annexes are more "specialized," and as such, > a critical mass of demand hasn't yet built up for them sufficient > to entice other vendors to implement them. However, with the > increasing interest in distributed component-based systems, even > among the real-time crowd, I would expect at least the distributed > annex to become more widely implemented. On the other hand, > Ada/Corba is a viable alternative (e.g. ORBExpress/Ada from Objective > Interface Systems), so that may have reduced the pressure for > the distributed annex. > I find the CORBA stuff to be daunting indeed. Base on many conversations with development folks, I find speaking to the distributed systems annex is much more natural then speaking about CORBA. CORBA is big and it is not Ada so I have to do alot of explaining to even begin to have a meaningful conversation. I don't have this problem when discussing the distributed systems annex which nicely maps distributed semantics to the language. I half expect a compiler vendor to implement the distributed system annex with CORBA. Given such a beast, I get the best of both worlds and the distributed systems annex provides a "natural" intermediary step to getting folks to take deeper steps into CORBA. From my limited knowledge of the specifics of CORBA, I don't think this would be a major effort. If this is true, then any vendor should be able to support Ada's distributed systems without a huge investment since CORBA solves many of the nitty-gritty implementation problems. -- Samuel T. Harris, Principal Engineer Raytheon, Scientific and Technical Systems "If you can make it, We can fake it!" ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-24 0:00 ` Samuel T. Harris @ 1999-02-25 0:00 ` robert_dewar 0 siblings, 0 replies; 12+ messages in thread From: robert_dewar @ 1999-02-25 0:00 UTC (permalink / raw) In article <36D44E24.E8888218@hso.link.com>, "Samuel T. Harris" <sam_harris@hso.link.com> wrote: > I half expect a compiler vendor to implement the > distributed > system annex with CORBA. Given such a beast, I get the > best > of both worlds and the distributed systems annex provides > a "natural" intermediary step to getting folks to take > deeper steps into CORBA. From my limited knowledge of the > specifics of CORBA, I don't think this would be a major > effort. If this is true, then any vendor should be able > to support Ada's distributed systems without a huge > investment since CORBA solves many of the nitty-gritty > implementation problems. It solves a very small part, and rather easy part, of the whole picture. Note that annex E requires pretty major compiler work to generate the required stubs. The use of CORBA may simplify parts of the PCS, but it also complicates other parts of it. Not at all clear that it would be a significant help at all in the implementation effort. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-24 0:00 ` Tucker Taft 1999-02-24 0:00 ` Samuel T. Harris @ 1999-02-25 0:00 ` JP Thornley 1999-02-25 0:00 ` dewar 1 sibling, 1 reply; 12+ messages in thread From: JP Thornley @ 1999-02-25 0:00 UTC (permalink / raw) In article: <36D43E60.9231A20@averstar.com> Tucker Taft <stt@averstar.com> writes: > I would also suspect that the safety-critical annex will be or > is already supported by a number of vendors, even if they > haven't validated against the Annex H tests. Ummm, is there a smiley missing off there? I'm sure that an early meeting of the Annex H Rapporteur (sp?) Group (about three years ago?) decided that it wasn't possible to define any sensible tests for the Annex H facilities. Phil Thornley. -- ------------------------------------------------------------------------ | JP Thornley EMail jpt@diphi.demon.co.uk | | phil.thornley@acm.org | ------------------------------------------------------------------------ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-25 0:00 ` JP Thornley @ 1999-02-25 0:00 ` dewar 0 siblings, 0 replies; 12+ messages in thread From: dewar @ 1999-02-25 0:00 UTC (permalink / raw) In article <727154320wnr@diphi.demon.co.uk>, jpt@diphi.demon.co.uk wrote: > Ummm, is there a smiley missing off there? I'm sure that > an early meeting of the Annex H Rapporteur (sp?) Group > (about three years ago?) decided that it wasn't possible > to define any sensible tests for the > Annex H facilities. > > Phil Thornley. No need to guess! Go look at the ACVC tests. Yes, of course there are tests for annex H! It is certainly true, as it is true for all parts of the language, that not all requirements are tested, and indeed, it is also true that Annex H has a rather high proportion of untestable stuff, but that does not mean it is ALL untestable. Indeed, the tests cannot be entirely trivial, since as people have noticed that many Ada 95 compilers cannot pass these tests, and do not claim annex H conformance as a result! Robert Dewar Ada Core Technologies -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-24 0:00 Compiler implementation of speciallized needs annexes Robert T. Sagris 1999-02-24 0:00 ` Tucker Taft @ 1999-02-25 0:00 ` dewar 1999-02-25 0:00 ` dennison 1999-03-01 0:00 ` Richard D Riehle 1 sibling, 2 replies; 12+ messages in thread From: dewar @ 1999-02-25 0:00 UTC (permalink / raw) In article <36D3A1EF.E7CA2A8C@physics.BLAH.purdue.BLAH.edu>, "Robert T. Sagris" <robs@physics.BLAH.purdue.BLAH.edu> > wrote: > I was wondering why only GNAT implements all of the > specialized needs annex's. All of the other vendors I > looked into implement A, B as they are required. C and D > are also generally implemented by everyone. Rational also > implements G. Actually you should check VSR's carefully, a lot of compilers do NOT fully implement annex D (for example, as far as we know, GNAT is the only compiler that fully implements annex D on VxWorks, including a full implementation of FIFO_Within_Priorities dispatching policy.) > Is this do to a lack of customer demand for these > features or is it something else? It is not so much a "lack of customer demand". Rather it is an issue of how much customer demand there is compared to the cost of implementation. Implementing annex E for instance is a very large task, and one that may well not be justified by customer demand. GNAT certainly has a number of customers for annex E, but if the decision had been a purely commercial one, who knows? In fact we decided very early on in the GNAT project that we would implement all the annexes. This decision was made even before ACT existed, and was part of the commitment of the GNAT project to providing a *complete* freely available Ada 95 system. Since our first validation was for all the annexes, we decided that we would go for 100% validations on all targets. That has not always been easy, but it makes for a consistent guarantee of completeness. Of course not every annex is required in every situation, and that is why it is perfectly practical to use compilers that lack annex features that you do not need. This was after all the whole point of defining optional special needs annexes in the first place. For example, the Intermetrics compiler for the Patriot 2 certainly does NOT need the Information Systems annex (Patriot missiles are not in the habit of performing payroll computations as they fly through the air :-) That being said, it would definitely be nice to see some other compilers implement some of the "missing" annexes. For one thing, it would be interesting to see if different compilers implementing Annex E could really communicate :-) Most certainly every vendor is driven by customer demand, so if you see something that is not implemented, then it is definitely likely to mean that> > I was just wondering > > Robbi Sagris > Robert Dewar Ada Core Technologies -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-25 0:00 ` dewar @ 1999-02-25 0:00 ` dennison 1999-02-26 0:00 ` Samuel Tardieu 1999-03-01 0:00 ` Richard D Riehle 1 sibling, 1 reply; 12+ messages in thread From: dennison @ 1999-02-25 0:00 UTC (permalink / raw) In article <7b2mpq$194$1@nnrp1.dejanews.com>, dewar@gnat.com wrote: > For one thing, it would be interesting to see if different > compilers implementing Annex E could really communicate :-) Are they supposed to be able to? That would indeed be very cool, but I didn't get that impression reading the annex myself. T.E.D. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-25 0:00 ` dennison @ 1999-02-26 0:00 ` Samuel Tardieu 0 siblings, 0 replies; 12+ messages in thread From: Samuel Tardieu @ 1999-02-26 0:00 UTC (permalink / raw) >>>>> "TED" == dennison <dennison@telepath.com> writes: TED> Are they supposed to be able to? That would indeed be very cool, TED> but I didn't get that impression reading the annex myself. Well, nothing in the Annex requires (or even encourages!) this, but other compilers could chose to use GNAT's PCS (Partition Communication Subsystem, a.k.a the runtime library) in a compatible way. Sam -- Samuel Tardieu -- sam@ada.eu.org ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-02-25 0:00 ` dewar 1999-02-25 0:00 ` dennison @ 1999-03-01 0:00 ` Richard D Riehle 1999-03-01 0:00 ` Larry Kilgallen 1999-03-02 0:00 ` dewar 1 sibling, 2 replies; 12+ messages in thread From: Richard D Riehle @ 1999-03-01 0:00 UTC (permalink / raw) In article <7b2mpq$194$1@nnrp1.dejanews.com>, dewar@gnat.com wrote: > >In fact we decided very early on in the GNAT project that >we would implement all the annexes. This decision was made >even before ACT existed, and was part of the commitment of >the GNAT project to providing a *complete* freely available >Ada 95 system. To paraphrase another famous line from United States politics, "Read my lips, no new syntax" Reusable Annexes. Now that would be a nice concept since there is no new syntax in the Annexes. And GNAT versions are largely coded in Ada, are they not? Perhaps, in the spirit of the FSF, other compiler publishers could simply incorporate the GNAT annexes into their product and avoid the duplication associated with more implementations. Richard Riehle www.adaworks.com ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-03-01 0:00 ` Richard D Riehle @ 1999-03-01 0:00 ` Larry Kilgallen 1999-03-02 0:00 ` dewar 1 sibling, 0 replies; 12+ messages in thread From: Larry Kilgallen @ 1999-03-01 0:00 UTC (permalink / raw) In article <7belqo$rl7@dfw-ixnews12.ix.netcom.com>, Richard D Riehle <laoXhai@ix.netcom.com> writes: > Perhaps, in the spirit of the FSF, other compiler publishers > could simply incorporate the GNAT annexes into their product and > avoid the duplication associated with more implementations. Legal issues aside, I believe multiple implementations provide for a robust Ada climate. Even if an annex item _can_ be implemented in Ada, some implementation might be able to do "better" with their own version. Larry Kilgallen ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Compiler implementation of speciallized needs annexes. 1999-03-01 0:00 ` Richard D Riehle 1999-03-01 0:00 ` Larry Kilgallen @ 1999-03-02 0:00 ` dewar 1 sibling, 0 replies; 12+ messages in thread From: dewar @ 1999-03-02 0:00 UTC (permalink / raw) In article <7belqo$rl7@dfw-ixnews12.ix.netcom.com>, Richard D Riehle <laoXhai@ix.netcom.com> wrote: > Perhaps, in the spirit of the FSF, other compiler > publishers could simply incorporate the GNAT annexes > into their product and avoid the duplication associated > with more implementations. To the extent that this is just a matter of acquiring copies of GNAT run time routines, this is fine, and indeed for a while at least Aonix was using some of the GNAT routines in their distribution. Providing the copyright is properly respected, and the license conditions followed this usage is welcome. However, it is unfortunately naive to suppose that this gets you very far. We have often heard of sales people for another Ada vendor claiming that it is no problem to have the System Information Annex, since you can just use the GNAT routines, but this is quite bogus. The GNAT implentation depends on some critical intrinsic routines in the compiler, and also on the full support of 18 digit decimal fixed-point. These are not run-time library issues. For the real-time annex, of course the GNAT run-time routines can be used, but this would require major compiler changes, to the point where it could hardly make sense. As for the distribution annex, sure you can use the GNAT PCS, but there is huge front end work to be done. In short, Richard's suggestion does not lead to much simplification in the hard task of implementing all the Annexes in their entirety in the context of a compiler other than GNAT. Robert Dewar Ada Core Technologies -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~1999-03-02 0:00 UTC | newest] Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 1999-02-24 0:00 Compiler implementation of speciallized needs annexes Robert T. Sagris 1999-02-24 0:00 ` Tucker Taft 1999-02-24 0:00 ` Samuel T. Harris 1999-02-25 0:00 ` robert_dewar 1999-02-25 0:00 ` JP Thornley 1999-02-25 0:00 ` dewar 1999-02-25 0:00 ` dewar 1999-02-25 0:00 ` dennison 1999-02-26 0:00 ` Samuel Tardieu 1999-03-01 0:00 ` Richard D Riehle 1999-03-01 0:00 ` Larry Kilgallen 1999-03-02 0:00 ` dewar
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox