From: mheaney@ni.net (Matthew Heaney)
Subject: Re: Rules for Representation of Subtypes
Date: 1996/09/30
Date: 1996-09-30T00:00:00+00:00 [thread overview]
Message-ID: <mheaney-ya023180003009961957480001@news.ni.net> (raw)
In-Reply-To: dewar.844114166@schonberg
In article <dewar.844114166@schonberg>, dewar@schonberg.cs.nyu.edu (Robert
Dewar) wrote:
>"I think his comment was in reaction a previous post, which stated that the
>compiler would make all kinds of optimizations based on what it knew was an
>illegal program as a result of a call to unchecked_conversion. If the
>compiler does something "special" to handle a "bad" program because of
>unchecked_conversion, well, the conversion is not really "unchecked,"
>right?"
>
>Can you be clearer as to what you mean? For a start I assume that the
>use of the word illegal should be erroneous? right?
>unchecked simply means that the compiler is not required to generate
>checking code for some error conditions, what else do you read into the
>word?
You're right; I should have said "...knew would cause erroneous program
execution..." Honestly, though, I'm a little shaky about the difference
between "erroneous execution," "bounded errors," "non portability," and
"illegal program." Guess I better hit the books before TRI-Ada!
I intended "unchecked" to mean as you suggested: don't put in checks for
error conditions (on the object that is returned by the call to
Unchecked_Conversion).
The author of the post (I think it was Larry K) just wanted to make sure
that the expression containing the Valid attribute didn't get optimized
away.
--------------------------------------------------------------------
Matthew Heaney
Software Development Consultant
mheaney@ni.net
(818) 985-1271
next prev parent reply other threads:[~1996-09-30 0:00 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-09-22 0:00 Rules for Representation of Subtypes Matthew Heaney
1996-09-23 0:00 ` David C. Hoos, Sr.
1996-09-23 0:00 ` Robert A Duff
1996-09-23 0:00 ` Samuel T. Harris
1996-09-26 0:00 ` David C. Hoos, Sr.
1996-09-24 0:00 ` Robert Dewar
1996-09-26 0:00 ` Keith Thompson
1996-09-26 0:00 ` Matthew Heaney
1996-09-27 0:00 ` Robert Dewar
1996-09-27 0:00 ` Robert A Duff
1996-09-27 0:00 ` Robert Dewar
1996-09-27 0:00 ` Robert A Duff
1996-09-24 0:00 ` Robert Dewar
1996-09-23 0:00 ` Robert A Duff
1996-09-24 0:00 ` Matthew Heaney
1996-09-26 0:00 ` Robert A Duff
1996-09-26 0:00 ` Larry Kilgallen
1996-09-27 0:00 ` Robert A Duff
1996-09-27 0:00 ` Mark A Biggar
1996-09-30 0:00 ` Robert A Duff
1996-10-01 0:00 ` Larry Kilgallen
1996-10-01 0:00 ` Robert A Duff
1996-10-01 0:00 ` Samuel Tardieu
1996-10-01 0:00 ` Valid Attribute and Unchecked Conversion Matthew Heaney
1996-10-02 0:00 ` Robert A Duff
1996-10-04 0:00 ` Keith Thompson
1996-10-04 0:00 ` Matthew Heaney
1996-10-07 0:00 ` Robert Dewar
1996-10-09 0:00 ` Keith Thompson
1996-10-04 0:00 ` Robert A Duff
1996-10-04 0:00 ` Robert Dewar
1996-10-11 0:00 ` Norman H. Cohen
1996-10-12 0:00 ` Robert Dewar
1996-10-06 0:00 ` Keith Thompson
1996-10-07 0:00 ` Robert Dewar
1996-10-09 0:00 ` Keith Thompson
1996-10-07 0:00 ` Ken Garlington
1996-10-08 0:00 ` Alan Brain
1996-10-07 0:00 ` Kenneth Almquist
1996-10-07 0:00 ` Robert Dewar
1996-10-10 0:00 ` Ken Garlington
1996-10-11 0:00 ` Robert Dewar
1996-10-14 0:00 ` Ken Garlington
1996-10-14 0:00 ` Keith Thompson
1996-10-01 0:00 ` Rules for Representation of Subtypes Ken Garlington
1996-09-28 0:00 ` Larry Kilgallen
1996-09-29 0:00 ` Robert A Duff
1996-09-29 0:00 ` Larry Kilgallen
1996-09-29 0:00 ` Matthew Heaney
1996-09-30 0:00 ` Robert A Duff
1996-10-01 0:00 ` Ken Garlington
1996-10-02 0:00 ` Robert A Duff
1996-10-02 0:00 ` Ken Garlington
1996-10-06 0:00 ` Robert Dewar
1996-09-29 0:00 ` Matthew Heaney
1996-09-30 0:00 ` Robert A Duff
1996-09-30 0:00 ` Robert Dewar
1996-09-30 0:00 ` Matthew Heaney [this message]
1996-10-03 0:00 ` Robert Dewar
1996-10-02 0:00 ` Valid Attribute and Unchecked Conversion Robert I. Eachus
1996-10-02 0:00 ` Matthew Heaney
1996-10-02 0:00 ` George Haddad
1996-10-03 0:00 ` John Herro
1996-10-04 0:00 ` Karl Cooper {46901}
1996-10-07 0:00 ` Mark A Biggar
1996-10-08 0:00 ` Robert Dewar
1996-10-05 0:00 ` Robert Dewar
1996-10-06 0:00 ` Keith Thompson
1996-10-14 0:00 ` Robert A Duff
1996-09-27 0:00 ` Rules for Representation of Subtypes Matthew Heaney
1996-09-27 0:00 ` Robert A Duff
-- strict thread matches above, loose matches on Subject: below --
1996-09-28 0:00 Robert Dewar
1996-09-29 0:00 ` Robert A Duff
1996-09-29 0:00 ` Matthew Heaney
1996-09-28 0:00 Robert Dewar
1996-09-30 0:00 ` Keith Thompson
1996-09-28 0:00 Robert Dewar
1996-09-29 0:00 ` Robert A Duff
1996-09-29 0:00 ` Matthew Heaney
1996-09-29 0:00 ` Robert Dewar
1996-09-30 0:00 ` Art Schwarz
1996-09-30 0:00 ` Robert A Duff
1996-10-01 0:00 ` Larry Kilgallen
1996-10-01 0:00 ` Brian R. Hanson
1996-10-01 0:00 ` Robert A Duff
1996-10-02 0:00 Franco Mazzanti
1996-10-03 0:00 ` Robert A Duff
1996-10-03 0:00 Franco Mazzanti
1996-10-03 0:00 ` Robert A Duff
1996-10-10 0:00 W. Wesley Groleau (Wes)
1996-10-10 0:00 ` Robert Dewar
1996-10-11 0:00 ` Ken Garlington
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