From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Subject: Re: Uninitialized out parameters.
Date: Wed, 6 Apr 2016 23:41:24 +0300
Date: 2016-04-06T23:41:24+03:00 [thread overview]
Message-ID: <dmlajeF9i5uU1@mid.individual.net> (raw)
In-Reply-To: <c7t9gb1972nrm7e64hudekqvi5pmldtm17@4ax.com>
On 16-04-06 14:44 , Dennis Lee Bieber wrote:
> On Wed, 6 Apr 2016 12:17:05 +0200, "G.B." <bauhaus@futureapps.invalid>
> declaimed the following:
>
>> On 06.04.16 10:19, ahlan@marriott.org wrote:
>>> On Tuesday, April 5, 2016 at 6:19:47 PM UTC+2, G.B. wrote:
>>>> On 05.04.16 14:02, ahlan@marriott.org wrote:
>>>>> Ada.Text_IO.Put_Line ("V:" & V'img);
>>>>>
>>>>> The value zero is output, which because V is positive should be impossible.
>>>>
>>>> Addressing just this issue: the line is calling
>>>> implementation defined attribute 'IMG, which can
>>>> do as it pleases. The Ada type attribute 'Image
>>>> takes a value of type Positive'Base, which includes 0,
>>>> which is why outputting 0 is perfectly fine.
>>>>
>>>> (It's not a subtype attribute, but a type attribute,
>>>> if this makes sense.)
>>>
>>> The issue here is not whether or not 'img fails but the fact that V is returned with a value out of range.
>>
>> The issue is rather, I think, whether V is returned at all.
>> There would have to be an assignment within the null procedure.
>>
> Which could be a case if the compiler used copy-in/copy-out semantics
> for scalars (or just copy-out for the test sample). GNAT, if I recall, uses
> reference semantics,
Then GNAT would be in violation of the Ada standard -- see RM 6.2(3/3).
I hope and believe that is not the case...
--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
next prev parent reply other threads:[~2016-04-06 20:41 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 12:02 Uninitialized out parameters ahlan
2016-04-05 13:17 ` rieachus
2016-04-05 14:07 ` ahlan
2016-04-06 9:45 ` Mark Lorenzen
2016-04-06 21:01 ` Jeffrey R. Carter
2016-04-07 7:10 ` ahlan
2016-04-05 16:19 ` G.B.
2016-04-06 8:19 ` ahlan
2016-04-06 10:17 ` G.B.
2016-04-06 11:44 ` Dennis Lee Bieber
2016-04-06 20:41 ` Niklas Holsti [this message]
2016-04-06 20:54 ` Randy Brukardt
2016-04-06 20:47 ` Randy Brukardt
2016-04-06 21:01 ` Randy Brukardt
2016-04-06 21:22 ` Dmitry A. Kazakov
2016-04-07 7:27 ` Randy Brukardt
2016-04-06 11:37 ` AdaMagica
2016-04-06 13:44 ` ahlan
2016-04-06 14:09 ` Mark Lorenzen
2016-04-06 14:10 ` G.B.
2016-04-06 20:53 ` Stefan.Lucks
2016-04-06 21:03 ` Randy Brukardt
2016-04-06 21:12 ` Niklas Holsti
2016-04-06 21:30 ` Randy Brukardt
2016-04-07 9:56 ` Stefan.Lucks
2016-04-07 16:08 ` AdaMagica
2016-04-07 23:02 ` Randy Brukardt
2016-04-08 7:32 ` Dmitry A. Kazakov
2016-04-07 7:52 ` Georg Bauhaus
-- strict thread matches above, loose matches on Subject: below --
1996-07-29 0:00 W. Wesley Groleau (Wes)
1996-07-18 0:00 Uninitialized "out" parameters Paul Whittington
1996-07-18 0:00 ` Robert Dewar
1996-07-19 0:00 ` Peter Amey
1996-07-20 0:00 ` Fergus Henderson
1996-07-20 0:00 ` Robert Dewar
1996-07-21 0:00 ` Fergus Henderson
1996-07-21 0:00 ` Robert Dewar
1996-07-23 0:00 ` Richard A. O'Keefe
1996-07-23 0:00 ` Robert Dewar
1996-07-24 0:00 ` Fergus Henderson
1996-07-24 0:00 ` Robert A Duff
1996-07-24 0:00 ` Fergus Henderson
1996-07-25 0:00 ` Richard A. O'Keefe
1996-07-25 0:00 ` Robert A Duff
1996-07-23 0:00 ` Robert A Duff
1996-07-24 0:00 ` Richard A. O'Keefe
1996-07-24 0:00 ` Robert A Duff
1996-07-25 0:00 ` Richard A. O'Keefe
1996-07-25 0:00 ` Robert A Duff
1996-07-24 0:00 ` Theodore E. Dennison
1996-07-25 0:00 ` Frank Manning
1996-07-25 0:00 ` Richard A. O'Keefe
1996-07-26 0:00 ` Frank Manning
1996-07-23 0:00 ` Fergus Henderson
1996-07-23 0:00 ` Robert A Duff
1996-07-24 0:00 ` Fergus Henderson
1996-07-24 0:00 ` Fergus Henderson
1996-07-18 0:00 ` Adam Beneschan
1996-07-18 0:00 ` Robert Dewar
1996-07-19 0:00 ` Pascal Obry
1996-07-19 0:00 ` Peter Hermann
1996-07-19 0:00 ` Samuel Tardieu
1996-07-19 0:00 ` John Herro
1996-07-19 0:00 ` Tucker Taft
1996-07-23 0:00 ` Peter Hermann
1996-07-23 0:00 ` Robert A Duff
1996-07-19 0:00 ` Dale Stanbrough
1996-07-19 0:00 ` Adam Beneschan
1996-07-19 0:00 ` James A. Squire
1996-07-19 0:00 ` Adam Beneschan
1996-07-20 0:00 ` Michael Feldman
1996-07-21 0:00 ` Fergus Henderson
1996-07-21 0:00 ` Michael Feldman
1996-07-21 0:00 ` Robert Dewar
1996-07-22 0:00 ` Fergus Henderson
1996-07-23 0:00 ` Michael Feldman
1996-07-23 0:00 ` Robert Dewar
1996-07-25 0:00 ` Fergus Henderson
1996-07-24 0:00 ` Robert A Duff
1996-07-25 0:00 ` Richard A. O'Keefe
1996-07-24 0:00 ` Fergus Henderson
1996-07-19 0:00 ` Peter Amey
1996-07-19 0:00 ` Michel Gauthier
1996-07-21 0:00 ` Robert A Duff
1996-07-21 0:00 ` Robert A Duff
1996-07-23 0:00 ` John Herro
1996-07-23 0:00 ` Robert A Duff
1996-07-23 0:00 ` Robert Dewar
1996-07-24 0:00 ` Peter Hermann
1996-07-26 0:00 ` Stephen J Bevan
1996-07-26 0:00 ` Robert A Duff
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