Re: Bug in Ada (SuSe 10.2) ?

["Jeffrey R. Carter" <spam.jrcarter.not@acm.nospam.org>]

Adam Beneschan wrote:
> 
> I'm not quite sure what this means, and what would have changed...
> There are definitely processors on which Ada is available for which
> integer overflow checks would add a significant execution penalty.
> (One processor I'm working with not only doesn't have the ability to
> fault on integer overflow, it doesn't even have a condition code
> status bit of any sort to indicate overflow.)  I guess I'm not sure
> what you mean by this.

I guess I could have been clearer. I meant on commonly used, current processors, 
and it may not be that the check is no longer expensive, but simply that it's 
not as expensive as it used to be. And I'm not an expert in these things.

> Well, if you're going to be pedantic, then even with those flags GNAT
> is not an Ada compiler, because I can give it Ada programs that it
> doesn't compile (not to mention non-Ada programs that it doesn't
> reject, and Ada programs that run incorrectly after GNAT compiles
> them).  And the same is doubtless true of any other compiler.  GNAT
> will not be an Ada compiler until they finally get the Last Bug out,
> which isn't going to happen because by the time they finally get Ada
> 2005 to be working 100% correctly, the Ada language will be up to Ada
> 2067 or so.
> 
> So maybe it's ridiculously pedantic to claim it's not Ada for that
> reason---but probably no moreso than for your reason.

I think there's quite a bit of difference between having (almost) all programs 
deliberately fail to implement the Ada semantics, and having an unintentional 
error in a compiler. The latter is trying to implement Ada; the former isn't. 
With its default options, GNAT is much more like the former than the latter.

-- 
Jeff Carter
"English bed-wetting types."
Monty Python & the Holy Grail
15