Re: Constraint checking of actuals passed to Attributes

[Robert A Duff <bobduff@world.std.com>]

Ted Dennison <dennison@telepath.com> writes:

> 
> In article <wccsnvnsdpv.fsf@world.std.com>,
>   Robert A Duff <bobduff@world.std.com> wrote:
> > Certainly you can cause abnormal objects, and erroneousness, by
> certain
> > misuses of address clauses and unchecked conversions of access values,
> > both of which can be used to make overlays.
> 
> Can you? The relevant section in 13.9.1 only mentions aborted
> assignements and parameters passed to imported procedures.

Well, for address clauses, I guess I should have said just "cause
erroneousness".  If it can do that, then it can do any other bad thing
you can name, so it's kind of silly to argue about whether it can cause
abnormal values.  13.3(13) says it can be erroneous.

For unchecked conversions, 13.9(11) says the result can be abnormal
except in certain (non-pointerish) cases.

The difference between abnormal and erroneous is pretty small --
abnormal is just one small step short of disaster (where erroneous =
disaster).

>... But then
> paragraph 14 does say that objects can become abnormal in other ways
> too. Perhaps my problem is that I'm missing where "abmormal" is truly
> defined.

Well, I was going to admonish you to look it up in the index, but I see
the index is incomplete in this case.  :-(
I suggest you get the plain-ascii version of the AARM, and search for
abnormal.

- Bob