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From: bobduff@world.std.com (Robert A Duff)
Subject: Re: To Initialise or not
Date: 1996/05/02
Message-ID: <DqsMC6.IwK@world.std.com>#1/1
X-Deja-AN: 152640224
references: <318508FE.204B@sanders.lockheed.com>
 <318792E8.28CC1042@escmail.orl.mmc.com> <Dqqws5.Dvr@world.std.com>
 <4masvn$1ai@linus.mitre.org>
organization: The World Public Access UNIX, Brookline, MA
newsgroups: comp.lang.ada
Date: 1996-05-02T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <4masvn$1ai@linus.mitre.org>,
Michael F Brenner <mfb@mbunix.mitre.org> wrote:
>I disagree that the compiler can "easily" detect uninitialized variables,
>or detect them at all. It is not possible to write a compiler that will
>detect the class of variables that are not initialized to a correct 
>value in the variables range (that is, all uninitialized variables and
>only unitialized variables), in a finite amount of time.

I'm not sure who you're disagreeing with.  I don't think anybody
suggested that this was possible.  It's not, since it's undecidable, in
general (nothing to do with amounts of time!).

It *is* possible, however, to detect all uninitialized variables at run
time, and detect *some* of them at compile time.

- Bob