Re: Overriding discriminants perplexes GNAT 3.14p

[Dmitry A.Kazakov <mailbox@dmitry-kazakov.de>]

Stephen Leake wrote:

> Dmitry A.Kazakov <mailbox@dmitry-kazakov.de> writes:
> 
>> Stephen Leake wrote:
>> 
>> > Dmitry A.Kazakov <mailbox@dmitry-kazakov.de> writes:
>> > 
>> >> People rightly criticize MS VC++, but the situation with Ada
>> >> compilers isn't much better.
>> > 
>> > Yes it is (in my experience). I've found bugs in _every_ compiler I've
>> > ever used. At least with GNAT I have a chance of getting them fixed!
>> 
>> First of all there are bugs and bugs. GNAT is at least ten years old, so
>> I would expect that one could not catch it on such primitive things. What
>> you are talking about is merely a quality of support, which is a very
>> important but yet another thing. Moreover, from what Robert Dewar said
>> before his departure, it looks like excellent and thus expensive support
>> actually harms quality. ACT intentionally limits the number of GNAT users
>> by those with very deep pockets and applications which do not require all
>> stregths of Ada. Should GNAT Pro be affordable for small and medium sized
>> projects, then Ada would be applied much more wider with so terrifying
>> ACT consequence of an increasing support demand.
> 
> You are making a couple of assumptions that I find dubious.
> 
> 1) More and cheaper customers = higher quality
> 
> I don't believe this, because the first consequence of more cheaper
> customers is to spread your support personnel thinner, so they have
> less time to write quality fixes for the bugs that get reported.

Consider personal PC's today and mainframes of 60's. In a long term 
perspective cheaper products bring higher quality. This could be [and 
usualy is] undesirable from the point of view of a product vendor. Well, 
this is how they try to resist to, let's say, progress and then disapper.

> 2) ACT customers do not require all strengths of Ada.
> 
> GNAT is the only compiler to support _all_ of the Ada Annexes. ACT
> only supports code that customers demand.

So they dropped JGNAT. Could this happen if GNAT were widely used in web 
applications?

> So I have to believe that
> there is at least one ACT customers using each part of Ada. Which also
> helps defeat assumption 1).

I hope so. But you should admit that a wider use of GNAT would make it 
better.

> Ok, it is certainly true that compilers perform differently on
> different types of code; I suspect your code is in a different domain
> than mine.

I have an impression that Object Ada better optimizes inlined code, but 
there are also cases where GNAT is better.

>> But what if mismanagement and "new economy" didn't kill DEC?
> 
> Then I'd be running VMS instead of Windows, and Linux would never have
> gotten started (hey, I can dream, can't I :).

A world free of UNIX! (:-))

-- 
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de