From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII
X-Google-Thread: 103376,a27864f6019f6e7f
X-Google-Attributes: gid103376,public
From: Vincent Marciante <marciant@li.net>
Subject: Re: Simpler Question (was Assigning to dereferenced null access
 variable)
Date: 2000/11/07
Message-ID: <3A089948.5979@li.net>#1/1
X-Deja-AN: 691009288
Content-Transfer-Encoding: 8bit
References: <3A05A609.4CE6@li.net> <3A0847ED.49AF@li.net>
 <8u9r97$jmb$2@wanadoo.fr>
Content-Type: text/plain; charset=iso-8859-1
X-Complaints-To: abuse@verio.net
X-Trace: iad-read.news.verio.net 973642042 209.139.0.141 (Wed,
 08 Nov 2000 00:07:22 GMT)
Organization: Verio
MIME-Version: 1.0
NNTP-Posting-Date: Wed, 08 Nov 2000 00:07:22 GMT
Newsgroups: comp.lang.ada
Date: 2000-11-07T00:00:00+00:00
List-Id: <comp.lang.ada>

Jean-Pierre Rosen wrote:
> 
> "Vincent Marciante" <marciant@li.net> a �crit dans le message news:3A0847ED.49AF@li.net...
> >[...]
> >     begin
> >         Null_Sequence.The_Characters(1..0) := Null_Characters;
> >         Put_Line("The Null_Characters assignment succeeded");
> >     exception
> >         when Constraint_Error =>
> >         Put_Line("The Null_Characters assignment caused
> > Constraint_Error");
> >         --OS/2 GNAT 3.12 raises Constraint_Error
> >     end;
> > end;
> Null_Sequence.The_Characters is a null pointer, there is no array to point to. This is what causes Constraint_Error, nothing to do
> with the assignment.
> 
> --
> ---------------------------------------------------------
>            J-P. Rosen (Rosen.Adalog@wanadoo.fr)
> Visit Adalog's web site at http://pro.wanadoo.fr/adalog

I thought that null_sequence.the_characters being a null pointer
should always cause constraint_error.   I will assume that you 
mean that the fact that no constraint_error ocurred in the first 
block (repeated below) indicates a compiler defect, so, I will send
a report to ACT.   Thanks.

    begin
        Null_Sequence.The_Characters(1..0) := Null_Characters(1..0);  
        Put_Line("The Null_Characters(1..0) assignment succeeded");
        --OS/2 GNAT 3.12 succeeds
    exception
        when Constraint_Error => 
        Put_Line("The Null_Characters(1..0) assignment caused Constraint_Error");
    end;