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From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Uninitialized "out" parameters
Date: 1996/07/26
Message-ID: <Dv5wCy.Hu2@world.std.com>#1/1
X-Deja-AN: 170782191
references: <31EEACDA.64880EEB@sage.inel.gov>
 <4t3f1u$t0u@newsbf02.news.aol.com> <dewar.838165848@schonberg>
 <STEPHENB.96Jul26101657@sorrol.harlqn.co.uk>
organization: The World Public Access UNIX, Brookline, MA
newsgroups: comp.lang.ada
Date: 1996-07-26T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <STEPHENB.96Jul26101657@sorrol.harlqn.co.uk>,
Stephen J Bevan <stephenb@harlequin.co.uk> wrote:
>I would have thought that the success of Purify shows that there is a
>great demand for such tools in the C(++) world.  It isn't clear to me
>why it should be any different for Ada.

Well, there are *some* differences.  Pointers can't be uninitialized in
Ada, and uninit pointers are probably the nastiest sort of uninit vars.
Also (in Ada 95 only), "A[I] := 7;" cannot overwrite arbitrary storage.
If I is uninit, then it will either trash some random element of A, or
raise an exception -- it won't trash anything *else*.

That said, I agree with you.  Purify-like tools are valuable for Ada,
too.

>...  I for one would be very
>interested in using an Ada compiler that could *optionally* detect
>references to uninitialised variables at runtime (and at compile time
>where possible),...

I agree.

- Bob