comp.lang.ada
 help / color / mirror / Atom feed
From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Can't set executable stack size during compilation
Date: Wed, 4 Jan 2012 19:06:40 -0600
Date: 2012-01-04T19:06:40-06:00	[thread overview]
Message-ID: <je2t32$20h$1@munin.nbi.dk> (raw)
In-Reply-To: 4f04c66c$0$6625$9b4e6d93@newsspool2.arcor-online.net

"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, 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.)

                                   Randy.





  reply	other threads:[~2012-01-05  1:06 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 [this message]
2012-01-05  4:35         ` Bill Findlay
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
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox