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From: Peter Amey <pna@erlang.praxis.co.uk>
Subject: Re: Ada strangeness or bug in Gnat?
Date: 1996/11/07
Message-ID: <Pine.SUN.3.91.961107084208.2384A-100000@erlang.praxis.co.uk>#1/1
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references: <E0FBxy.Jwq@cerc.wvu.edu> <328028AE.757F@direct.ca>
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Date: 1996-11-07T00:00:00+00:00
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> rodemann@mathematik.uni-ulm.de (Joerg Rodemann) writes:
> > Sure? Soory, but i haven't got my RM at hand right now. But i tried this
> > sample program with GNAT-3.05 on HPUX 10.10. It says: 1,2. That means the
> > array elements were swapped --- correctly?
> 
> The PA-RISC port of GNAT has some esoteric problems...  (in the
> backend, to be more precise)
> 
> I wouldn't posit the correctness of my programs on the basis of the
> results I get upon running it on this platform.
> 

The whole point of the example is that _either_ result is allowed by a
legal compiler which is why the Ada is considered erroneous (to use the
Ada83 term). 

If you must, because of the importance of your software, avoid such
problems entirely then you need to use additional development tools, such
as the SPARK Examiner, which detect all instances of aliasing. 

Peter