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Groups > comp.lang.c > #126772 > unrolled thread
| Started by | lee@ansync.com |
|---|---|
| First post | 2018-02-15 17:20 -0800 |
| Last post | 2018-02-26 10:17 -0800 |
| Articles | 3 on this page of 83 — 14 participants |
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Opinion sought: Is this strictly conforming C? lee@ansync.com - 2018-02-15 17:20 -0800
Re: Opinion sought: Is this strictly conforming C? James Kuyper <jameskuyper@verizon.net> - 2018-02-15 22:15 -0500
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-16 08:44 -0800
Re: Opinion sought: Is this strictly conforming C? jameskuyper@verizon.net - 2018-02-16 11:47 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-16 13:00 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-19 12:25 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-19 13:21 -0800
Re: Opinion sought: Is this strictly conforming C? Randy Howard <rhoward.mx@EverybodyUsesIt.com> - 2018-02-19 15:26 -0600
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-19 13:59 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-19 14:38 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-19 15:21 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-19 15:59 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-19 17:11 -0800
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-02-20 09:17 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-20 07:58 -0800
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-02-20 18:21 +0100
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-20 09:25 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-20 11:52 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-20 22:27 -0500
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-20 23:07 -0800
Re: Opinion sought: Is this strictly conforming C? Manfred <noname@invalid.add> - 2018-02-21 14:07 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-21 09:02 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-21 09:50 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-21 12:46 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-21 13:09 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-21 15:15 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-21 15:51 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-21 17:06 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-21 17:46 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 00:18 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 22:14 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 11:39 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-21 14:59 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-21 22:14 -0500
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 00:50 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-22 07:22 -0500
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 12:40 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-22 13:00 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 13:48 -0800
Re: Opinion sought: Is this strictly conforming C? scott@slp53.sl.home (Scott Lurndal) - 2018-02-22 22:14 +0000
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 23:05 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 23:39 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-22 10:39 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 13:20 -0800
Re: Opinion sought: Is this strictly conforming C? asetofsymbols@gmail.com - 2018-02-23 00:30 -0800
Re: Opinion sought: Is this strictly conforming C? Manfred <noname@invalid.add> - 2018-02-16 20:05 +0100
Re: Opinion sought: Is this strictly conforming C? lee@ansync.com - 2018-02-16 11:14 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-19 11:30 -0800
Re: Opinion sought: Is this strictly conforming C? Steve Carroll <frelwizzen@gmail.com> - 2018-03-01 09:01 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-19 11:08 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-19 17:16 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 23:16 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-22 00:25 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-22 07:41 -0500
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-24 13:24 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-25 12:07 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-25 18:34 -0500
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-26 08:21 -0800
Re: Opinion sought: Is this strictly conforming C? Richard Damon <Richard@Damon-Family.org> - 2018-02-26 22:22 -0500
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-02-27 09:16 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-27 08:48 -0800
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-02-28 10:24 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-28 09:03 -0800
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-02-28 22:31 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-28 15:19 -0800
Re: Opinion sought: Is this strictly conforming C? David Brown <david.brown@hesbynett.no> - 2018-03-01 12:37 +0100
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-03-01 11:03 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-03-01 11:22 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 11:48 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 15:11 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 16:14 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 19:53 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 21:27 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-02 00:52 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-02 01:54 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-03 06:11 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-03-01 12:31 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-03-01 13:15 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-01 14:55 -0800
Re: Opinion sought: Is this strictly conforming C? Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-03 02:19 -0800
Re: Opinion sought: Is this strictly conforming C? Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-03 03:03 -0800
Re: Opinion sought: Is this strictly conforming C? Keith Thompson <kst-u@mib.org> - 2018-02-25 15:36 -0800
Re: Opinion sought: Is this strictly conforming C? supercat@casperkitty.com - 2018-02-26 10:17 -0800
Page 5 of 5 — ← Prev page 1 2 3 4 [5]
| From | Steven Petruzzellis <frelwizzen@gmail.com> |
|---|---|
| Date | 2018-03-03 03:03 -0800 |
| Message-ID | <ba184e18-831a-4f23-b70e-428f2b6d263d@googlegroups.com> |
| In reply to | #127312 |
On Saturday, March 3, 2018 at 3:19:35 AM UTC-7, Tim Rentsch wrote: > > Stop "suggesting", and try thinking. > > Now there is an ironic suggestion. Over and over, the claim is he wants to "talk tech", but Autumn Nissen spends most of his time whining about "Xfce". I am not fuming, just the opposite I am busting a gut because Autumn Nissen's nonsense is so transparent. He actively did not list all the benchmarks that he would later insist are needed... and we all know why, he has is such a moron. At least he has morons in his corner ;) Allah's computer has more cores than Autumn Nissen's. Allah wins. Autumn Nissen loses. Nothing LCD about it. -- E-commerce Simplified!! https://youtu.be/E3m_i-x92D0 Jonas Eklundh Communication AB
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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Date | 2018-02-25 15:36 -0800 |
| Message-ID | <ln4lm4k5g7.fsf@kst-u.example.com> |
| In reply to | #127045 |
supercat@casperkitty.com writes:
[...]
> There are a number of situations where the behavior of some
> action would be described by the combination of the Standard
> and an implementation's documentation and yet also classified
> as Undefined. There are at least two ways one can interpret
> such an apparent contradiction:
>
> 1. Interpret the statement that the behavior is undefined as
> saying that the Standard imposes no requirements on the
> behavior of that action on any implementation, *even those
> where it would be defined elsewhere*.
That's what "undefined behavior" means:
behavior, upon use of a nonportable or erroneous program construct
or of erroneous data, for which this International Standard imposes
no requirements
For example, a secondary standard might define the behavior of
some construct whose behavior is not defined by the C standard.
An implementation that conforms to such a secondary standard is
required to behave accordingly -- but it's not required to do so
*by the C standard*.
This isn't complicated.
> 2. Interpret the statement that the behavior is undefined as
> saying that there is no requirement that implementations
> treat the behavior as defined *except when it is defined
> elsewhere*.
I'm not at all sure what this means. Implementations are already
required to obey any requirements imposed by secondary standards --
but such requirements are imposed by those secondary standards.
If you're suggesting that the C standard should require such
conformance, I don't see the point.
> The Standard makes no distinction between these two forms; applying
> the first consistently would yield a silly language in which many
> constructs would be all but useless [e.g. arrays of non-character
> types, or structures or unions that contain non-character members,
> could only have their elements or members accessed using memcpy
> other character-based means],
I think you've gotten stuck on the idea that N1570 6.5p7 implies that
this:
int arr[10];
arr[5] = 42;
has undefined behavior because it accesses arr (of type int[10]) using
an lvalue of type int.
It's obvious that the above is intended to be well defined by
the C standard. It's possible that there's a flaw in 6.5p7 that
seemingly makes it undefined (I haven't studied it closely enough
to have an opinion one way or the other). If there is such a flaw,
the solution is to fix the flaw, not to throw away the meaning of
"undefined behavior" and reinterpret the standard according to
your preferences.
> while applying the second
> consistently would yield a language which both useful and practical
> to implement.
>
> If the first interpretation should be used in some places, but
> the second should be used in others, different terminology should
> be used to distinguish them.
>
> You may regard the second interpretation as delusional, but the
> first would be absurd and I don't really see any basis for saying
> that the first interpretation is correct in places where it is too
> totally absurd, in which case the second should apply.
How about this?
1. Conforming C implementations are required to obey the requirements
of the C standard.
2. C implementations that claim to conform a secondary standard are
require to obey the requirements of the secondary standard. (This
requirement is, of course, imposed by the secondary standard, not by
the C standard.)
I think that is practically equivalent to your second interpretation --
and it reflects reality.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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| From | supercat@casperkitty.com |
|---|---|
| Date | 2018-02-26 10:17 -0800 |
| Message-ID | <8f427d65-da38-427a-bfb1-4be68db3a1d6@googlegroups.com> |
| In reply to | #127057 |
On Sunday, February 25, 2018 at 5:36:20 PM UTC-6, Keith Thompson wrote:
> I think you've gotten stuck on the idea that N1570 6.5p7 implies that
> this:
> int arr[10];
> arr[5] = 42;
> has undefined behavior because it accesses arr (of type int[10]) using
> an lvalue of type int.
>
> It's obvious that the above is intended to be well defined by
> the C standard. It's possible that there's a flaw in 6.5p7 that
> seemingly makes it undefined (I haven't studied it closely enough
> to have an opinion one way or the other). If there is such a flaw,
> the solution is to fix the flaw, not to throw away the meaning of
> "undefined behavior" and reinterpret the standard according to
> your preferences.
The Standard has never defined things precisely enough to be usable without
some fudging in the interpretation. Would you suggest that programmers given
that state of affairs should have:
1. Simply declared the the language as specified was unworkable, and
refused program in C unless or until the spec was fixed, or...
2. Expected that compiler writers would recognize that the Standard
was incomplete, and would not regard code whose behavior had been
processed consistently by other compilers for similar targets and
application fields as "broken" merely because the Standard did not
define it.
> > while applying the second
> > consistently would yield a language which both useful and practical
> > to implement.
> >
> > If the first interpretation should be used in some places, but
> > the second should be used in others, different terminology should
> > be used to distinguish them.
> >
> > You may regard the second interpretation as delusional, but the
> > first would be absurd and I don't really see any basis for saying
> > that the first interpretation is correct in places where it is too
> > totally absurd, in which case the second should apply.
>
> How about this?
>
> 1. Conforming C implementations are required to obey the requirements
> of the C standard.
>
> 2. C implementations that claim to conform a secondary standard are
> require to obey the requirements of the secondary standard. (This
> requirement is, of course, imposed by the secondary standard, not by
> the C standard.)
>
> I think that is practically equivalent to your second interpretation --
> and it reflects reality.
The problem is that nobody thought it necessary to define any kind of
official secondary standard to describe behaviors that were, at the time,
common to general-purpose C implementations that didn't target weird
hardware; the fact that something was a general-purpose implementation
targeting typical hardware was viewed as sufficient to imply the behaviors
in question.
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