From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
Subject: Re: Interfacing with C ; an ununsed fields dilemma
Date: Thu, 02 Jul 2009 11:51:46 +0200
Date: 2009-07-02T11:51:47+02:00 [thread overview]
Message-ID: <4a4c8333$0$32672$9b4e6d93@newsspool2.arcor-online.net> (raw)
In-Reply-To: <faaa30f7-d69b-4c73-ae70-9b01d3804077@d32g2000yqh.googlegroups.com>
Hibou57 (Yannick Duch�ne) schrieb:
> Hello to all,
>
> Once again, a topic about interfacing with C structures.
>
> A lot of C structure are defined with so called � unused field
> reserved for future use � (oftenly never used in any future). This
> fields are generally to be initialized to zero, what is required, to
> unsure it will not be errorneously interpreted by the exogenous part
> of the application, specially if it is dynamically linked to the
> application (beceause then, its version or its implementation may be
> differente and unknown of the application which rely on it).
>
> And here is the dilemma :
>
> Using clause representation, it is tempting to simply drop this
> unuseful unusedfields from the visible part of the declaration (yeah
> dear friend, lot cleaner, really tempting),
Omitting things might be acceptable in mathematical
discourse, but actually writing things down helps a
lot in programming, at least it helps me as a reader,
not up for solving (inter-)language puzzles.
You explanation of the record's gap fields is itself a hint
that these components do need some attention.
Shouldn't therefore Martin's example be the way to go?
This has been discussed before, topics included
for X use all
record
...
end record;
pragma Zero_Fill and Unchecked_Conversion (for setting bits to 0);
next prev parent reply other threads:[~2009-07-02 9:51 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-02 6:20 Interfacing with C ; an ununsed fields dilemma Hibou57 (Yannick Duchêne)
2009-07-02 9:25 ` Martin
2009-07-02 18:14 ` reserved fields; was " tmoran
2009-07-02 9:45 ` Maciej Sobczak
2009-07-02 12:01 ` Hibou57 (Yannick Duchêne)
2009-07-02 12:09 ` Georg Bauhaus
2009-07-02 13:21 ` Hibou57 (Yannick Duchêne)
2009-07-02 15:50 ` Georg Bauhaus
2009-07-02 14:52 ` Maciej Sobczak
2009-07-02 23:21 ` Hibou57 (Yannick Duchêne)
2009-07-03 7:21 ` Maciej Sobczak
2009-07-02 9:51 ` Georg Bauhaus [this message]
2009-07-02 10:16 ` Martin
2009-07-02 11:48 ` Hibou57 (Yannick Duchêne)
2009-07-02 15:55 ` Robert A Duff
2009-07-04 0:03 ` Randy Brukardt
2009-07-03 6:59 ` anon
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