From: Robert A Duff <bobduff@shell01.TheWorld.com>
Subject: Re: ADA compilers can reject types arbitrarily?
Date: 14 Nov 2005 22:12:59 -0500
Date: 2005-11-14T22:12:59-05:00 [thread overview]
Message-ID: <wccu0eemwn8.fsf@shell01.TheWorld.com> (raw)
In-Reply-To: slrndnikpp.ish.bogus_addy@tango.mindfuq.org
Anonymous Coward <nospam@nospam.com> writes:
> In article <wcchdafhxo5.fsf@shell01.TheWorld.com>,
> Robert A Duff wrote:
> >
> > But surely it makes no sense for the size of an object to always be
> > the same as the type's size. Boolean'Size = 1, but you want to
> > allocate Boolean variables in 32-bit registers, quite often.
>
> Ah, yes.. I had forgotten that a types size is the same as the value
> size, since I was dealing with records. It didn't occur to me that
> record type size specs should really be treated the same as they would
> be w/ integers; so that makes sense.
Well, records can be small, too. E.g a packed record containing
three booleans could have 'Size = 3, but you want to allocate objects in
a 32-bit register.
>...Considering type sizes are
> really value sizes, it's more clear to me now why T'size would only
> specify a minimum. I assume I can expect an O'size spec to be
> absolute (O being an object).
Yes.
> No way! So an ADA compiler can arbitrarily decide whether to accept a
> rep spec?
No, there are all kinds of rules and regulations about what a compiler
has to support, and what it is allowed to support. See section C.2,
which applies if the SP annex is supported. I think you can safely
count on SP annex support in all Ada compilers of interest.
My example was T'Size = 0 -- there aren't many types that fit in 0 bits.
- Bob
next prev parent reply other threads:[~2005-11-15 3:12 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-04 2:21 Default rep specs for record types - documented?? Anonymous Coward
2005-11-04 2:36 ` Steve
2005-11-04 4:11 ` Anonymous Coward
2005-11-04 5:30 ` Jeffrey R. Carter
2005-11-05 3:13 ` Steve
2005-11-05 4:45 ` Jeffrey R. Carter
2005-11-06 14:05 ` Steve
2005-11-06 16:08 ` Anonymous Coward
2005-11-07 7:25 ` Jeffrey R. Carter
2005-11-08 13:36 ` Steve
2005-11-14 1:12 ` Robert A Duff
2005-11-14 3:03 ` Anonymous Coward
2005-11-14 18:08 ` Jeffrey R. Carter
2005-11-14 18:49 ` Robert A Duff
2005-11-15 1:16 ` ADA compilers can reject types arbitrarily? Anonymous Coward
2005-11-15 2:10 ` tmoran
2005-11-15 3:12 ` Robert A Duff [this message]
2005-11-15 6:44 ` Simon Wright
2005-11-16 0:16 ` Adaists Deny Acronym. (was: ADA compilers can reject types arbitrarily?) Björn Persson
2005-11-16 5:38 ` Adaists Deny Acronym Simon Wright
2005-11-16 6:16 ` Adaists Deny Acronym. (was: ADA compilers can reject types arbitrarily?) Samuel Tardieu
2005-11-15 12:43 ` ADA compilers can reject types arbitrarily? Jeff Creem
2005-11-14 21:14 ` Default rep specs for record types - documented?? Simon Wright
2005-11-04 13:26 ` Stephen Leake
2005-11-04 14:33 ` Marc A. Criley
2005-11-04 18:35 ` Georg Bauhaus
2005-11-04 20:07 ` Britt Snodgrass
2005-11-04 14:39 ` Stephen Leake
2005-11-04 15:27 ` Britt Snodgrass
2005-11-04 15:55 ` Lauri Ora
2005-11-04 21:42 ` Larry Kilgallen
2005-11-05 2:26 ` Anonymous Coward
2005-11-05 2:42 ` Frank J. Lhota
2005-11-05 3:27 ` Ed Falis
2005-11-05 3:55 ` Anonymous Coward
2005-11-05 4:07 ` Lauri Ora
2005-11-05 13:46 ` Ed Falis
2005-11-05 10:14 ` Stephen Leake
2005-11-04 16:52 ` Frank J. Lhota
2005-11-04 16:57 ` Frank J. Lhota
2005-11-04 23:27 ` tmoran
2005-11-05 10:25 ` Stephen Leake
2005-11-14 1:09 ` Robert A Duff
2005-11-05 3:33 ` Anonymous Coward
2005-11-05 10:34 ` Stephen Leake
2005-11-05 16:35 ` ADA/C interfaces: type representations uncontrollable in C Anonymous Coward
2005-11-05 16:49 ` Ed Falis
2005-11-05 18:24 ` tmoran
2005-11-09 2:12 ` 'Size can mean value size OR object size, depending Anonymous Coward
2005-11-09 3:27 ` Jeffrey R. Carter
2005-11-09 4:04 ` Anonymous Coward
2005-11-05 14:27 ` Default rep specs for record types - documented?? Michael Bode
2005-11-05 16:17 ` pragma convention Anonymous Coward
2005-11-06 1:07 ` Jeffrey R. Carter
2005-11-06 22:22 ` Anonymous Coward
2005-11-07 7:34 ` Jeffrey R. Carter
2005-11-05 14:39 ` Default rep specs for record types - documented?? Martin Krischik
2005-11-04 9:40 ` Martin Dowie
2005-11-04 14:36 ` Marc A. Criley
2005-11-04 17:45 ` Martin Krischik
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