From: Simon Wright <simon.j.wright@mac.com>
Subject: Re: Contracted exceptions for Ada
Date: Sun, 09 Dec 2007 18:39:31 +0000
Date: 2007-12-09T18:39:31+00:00 [thread overview]
Message-ID: <m23aubiufw.fsf@mac.com> (raw)
In-Reply-To: 1bvj0n3ana6zj.1b1q7na2q2i0a.dlg@40tude.net
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> On Sun, 09 Dec 2007 16:11:13 +0100, Martin Krischik wrote:
>
>> Dmitry A. Kazakov wrote:
>>
>>> (Maybe a wild guess, but this could save Ariane V. A program assumed
>>> Constraint_Error exception free was recompiled for the hardware where that
>>> was not the case.)
>>
>> My understanding is that the system was brought down by an unexpected
>> hardware exception - i.E. one which the CPU's floating point unit
>> generated.
>
> Yes, and that would be detected by the compiler:
>
> function Integer (X : Float) return Integer;
>
> which was contracted as exception-free on one platform will not be on
> another. So the compiler would reject either its implementation that raises
> Constraint_Error or else its use contracted as Constraint_Error-free. So
> the idea.
I don't see how the compiler/platform in use has anything to do with
this.
In Ariane IV the maximum horizontal velocity is X.
Therefore we can convert the hardware input to this-type without
worrying about overflow.
Therefore any exception will be caused by hardware error.
seems a proper analysis for Ariane IV; reusing precisely the same
software/platform in an environment where the maximum horizontal
velocity was much larger than X is an error that no amount of
*software* engineering is going to fix.
next prev parent reply other threads:[~2007-12-09 18:39 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-06 15:00 Exceptions shaunpatterson
2007-12-06 21:24 ` Exceptions tmoran
2007-12-07 8:54 ` Exceptions Dmitry A. Kazakov
2007-12-07 10:21 ` Exceptions Georg Bauhaus
2007-12-07 15:11 ` Exceptions shaunpatterson
2007-12-07 16:08 ` Exceptions Gautier
2007-12-07 18:56 ` Exceptions Simon Wright
2007-12-08 10:04 ` Exceptions Stephen Leake
2007-12-08 3:30 ` Exceptions Randy Brukardt
2007-12-08 10:09 ` Contracted exceptions for Ada (was: Exceptions) Dmitry A. Kazakov
2007-12-09 10:22 ` Contracted exceptions for Ada Stephen Leake
2007-12-09 11:02 ` Dmitry A. Kazakov
2007-12-11 8:10 ` Stephen Leake
2007-12-11 10:36 ` Dmitry A. Kazakov
2007-12-09 15:11 ` Contracted exceptions for Ada (was: Exceptions) Martin Krischik
2007-12-09 17:36 ` Contracted exceptions for Ada Dmitry A. Kazakov
2007-12-09 18:39 ` Simon Wright [this message]
2007-12-10 8:19 ` Dmitry A. Kazakov
2007-12-10 20:25 ` Simon Wright
2007-12-11 8:50 ` Dmitry A. Kazakov
2007-12-11 20:50 ` Simon Wright
2007-12-12 10:20 ` Dmitry A. Kazakov
2007-12-09 19:04 ` Martin Krischik
2007-12-10 8:20 ` Dmitry A. Kazakov
2007-12-09 22:09 ` Robert A Duff
2007-12-10 7:09 ` Stefan Lucks
2007-12-10 16:57 ` Robert A Duff
2007-12-11 1:53 ` Contracted exceptions for Ada (was: Exceptions) Randy Brukardt
2007-12-11 9:16 ` Contracted exceptions for Ada Dmitry A. Kazakov
2007-12-12 0:26 ` Randy Brukardt
2007-12-08 12:26 ` Exceptions Peter C. Chapin
2007-12-08 14:01 ` Exceptions Dmitry A. Kazakov
2007-12-08 18:01 ` Exceptions Peter C. Chapin
2007-12-09 10:06 ` Exceptions Dmitry A. Kazakov
2007-12-09 12:40 ` Exceptions Peter C. Chapin
2007-12-09 14:31 ` Exceptions Dmitry A. Kazakov
2007-12-09 16:38 ` Exceptions Peter C. Chapin
2007-12-10 8:31 ` Exceptions Dmitry A. Kazakov
2007-12-09 21:56 ` Exceptions Robert A Duff
2007-12-09 10:24 ` Exceptions Stephen Leake
2007-12-09 12:46 ` Exceptions Peter C. Chapin
2007-12-09 21:39 ` Exceptions Robert A Duff
2007-12-09 22:13 ` Exceptions Georg Bauhaus
2007-12-11 8:07 ` Exceptions Stephen Leake
2007-12-11 20:28 ` Exceptions Simon Wright
2007-12-12 22:10 ` Exceptions Maciej Sobczak
2007-12-13 13:40 ` Exceptions Robert A Duff
2007-12-13 14:00 ` Exceptions Maciej Sobczak
2007-12-13 14:44 ` Exceptions Robert A Duff
2007-12-14 0:46 ` Exceptions Ray Blaak
2007-12-14 2:36 ` Exceptions Randy Brukardt
2007-12-14 6:21 ` Exceptions Ray Blaak
2007-12-14 12:40 ` Exceptions Georg Bauhaus
2007-12-14 17:29 ` Exceptions Robert A Duff
2007-12-14 19:32 ` Exceptions Dmitry A. Kazakov
2007-12-15 5:29 ` Exceptions Ray Blaak
2007-12-13 19:29 ` Exceptions Randy Brukardt
2007-12-12 19:18 ` Exceptions Martin Krischik
2007-12-13 13:27 ` Exceptions Robert A Duff
2007-12-13 23:25 ` Exceptions Ray Blaak
2007-12-06 21:25 ` Exceptions Gautier
2007-12-07 4:29 ` Exceptions anon
2007-12-07 4:43 ` Exceptions, part 2 anon
2007-12-07 16:55 ` Exceptions Adam Beneschan
2007-12-07 18:59 ` Exceptions Simon Wright
2007-12-08 0:38 ` Exceptions Adam Beneschan
2007-12-09 21:45 ` Exceptions Robert A Duff
2007-12-09 22:40 ` Exceptions Georg Bauhaus
2007-12-10 8:22 ` Exceptions Dmitry A. Kazakov
2007-12-10 9:20 ` Exceptions Georg Bauhaus
2007-12-10 9:30 ` Exceptions Georg Bauhaus
2007-12-10 10:56 ` Exceptions Dmitry A. Kazakov
2007-12-11 2:18 ` Exceptions Randy Brukardt
2007-12-11 8:19 ` Exceptions Georg Bauhaus
2007-12-11 11:55 ` Exceptions Dmitry A. Kazakov
2007-12-11 16:13 ` Exceptions Georg Bauhaus
2007-12-12 11:18 ` Exceptions Dmitry A. Kazakov
2007-12-10 12:09 ` Exceptions Niklas Holsti
2007-12-10 13:08 ` Exceptions Dmitry A. Kazakov
2007-12-10 20:02 ` Exceptions Niklas Holsti
2007-12-11 12:31 ` Exceptions Dmitry A. Kazakov
2007-12-11 13:21 ` Exceptions Niklas Holsti
2007-12-12 0:01 ` Exceptions Randy Brukardt
2007-12-12 11:37 ` Exceptions Niklas Holsti
2007-12-12 13:14 ` Exceptions Dmitry A. Kazakov
2007-12-12 14:37 ` Exceptions Robert A Duff
2007-12-13 19:20 ` Exceptions Randy Brukardt
2007-12-13 20:15 ` Exceptions Robert A Duff
2007-12-12 11:00 ` Exceptions Dmitry A. Kazakov
2007-12-11 2:12 ` Exceptions Randy Brukardt
2007-12-11 15:17 ` Exceptions Robert A Duff
2007-12-12 0:10 ` Exceptions Randy Brukardt
2007-12-13 19:58 ` Exceptions Robert A Duff
2007-12-14 0:53 ` Exceptions Ray Blaak
2007-12-14 2:48 ` Exceptions Randy Brukardt
2007-12-14 6:33 ` Exceptions Ray Blaak
2007-12-08 10:03 ` Exceptions Stephen Leake
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