From: Bill Findlay <yaldnif.w@blueyonder.co.uk>
Subject: Re: Can't set executable stack size during compilation
Date: Thu, 05 Jan 2012 04:35:43 +0000
Date: 2012-01-05T04:35:43+00:00 [thread overview]
Message-ID: <CB2AD91F.DE37%yaldnif.w@blueyonder.co.uk> (raw)
In-Reply-To: je2t32$20h$1@munin.nbi.dk
On 05/01/2012 01:06, in article je2t32$20h$1@munin.nbi.dk, "Randy Brukardt"
<randy@rrsoftware.com> wrote:
> "Georg Bauhaus" <rm-host.bauhaus@maps.futureapps.de> wrote in message
> news:4f04c66c$0$6625$9b4e6d93@newsspool2.arcor-online.net...
>> On 1/4/12 6:22 PM, Bill Findlay wrote:
>>> On 04/01/2012 16:27, in article
>>> 4f047e0f$0$6582$9b4e6d93@newsspool3.arcor-online.net, "Georg Bauhaus"
>>> <rm.dash-bauhaus@futureapps.de> wrote:
>>>>
>>>> FWIW, I made a little test program; I think it is legal
>>>
>>> It's not legal, of course: it fetches unassigned variables,
>>
>> I had though that variables not assigned (uninitialized?)
>> won't be the subject of legality rules (and would otherwise
>> have to be rejected during compilation or post-compilation)?
>>
>> If the program did perform I/O, its executions is likely
>> to have error, yes.
>
> Formally, an "illegal" program is one that fails a Legality Rule, and those
> are checked at compile-time.
>
> I suspect that Bill has being more informal ...
Yes, I wasn't being legalistic, just pragmatic. 8-)
> ... but even then, an Ada program can use an uninitialized value without the
> program being bad (erroneous); doing so might only be a bounded error and
> may not raise any exception at all depending on what is actually done.
> ("Invalid" values are allowed so long as they are not used to do array
> indexing and some other things.)
As it happens, when I ran it I got:
> /Users/wf/KDF9/emulation/Build: ./onstack
>
> raised CONSTRAINT_ERROR : onstack.adb:19 range check failed
because my default GNAT switches ask it to (attempt to) check for uses of
uninitialized variables.
--
Bill Findlay
with blueyonder.co.uk;
use surname & forename;
next prev parent reply other threads:[~2012-01-05 4:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 15:49 Can't set executable stack size during compilation Erich
2012-01-04 16:27 ` Georg Bauhaus
2012-01-04 17:22 ` Bill Findlay
2012-01-04 21:36 ` Georg Bauhaus
2012-01-05 1:06 ` Randy Brukardt
2012-01-05 4:35 ` Bill Findlay [this message]
2012-01-05 10:19 ` Georg Bauhaus
2012-01-05 12:35 ` Erich
2012-01-05 3:03 ` Jerry
2012-01-05 13:20 ` Mark Lorenzen
2012-01-05 3:12 ` Jerry
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