to guru : strange C++ operator behaviour

[WW]

Re: [OT] Re: to guru : strange C++ operator behaviour

Howard wrote:[color=blue]
> AAARRRGGH Would you just read my earlier response to WW, and the
> specific statement I was responding to? WW stated the following:
>
> "The compiler is allowed to do whatever it wants, including
> formatting your harddisk."
>
> This very explicitly is talking about an action by the compiler, and
> all I said was that if someone wrote their compiler so that it
> intentionally DID reformat my hard drive, I'd sue.[/color]

Intentionally? "The compiler is allowed to do whatever it wants". Blame it
on my English. But I did not mean that the compiler will do it during
compilation. And I definitely did not mean it was/will be intentional! But
even if it would be - it would be still conforming. And - strictly
speaking - you would have a hard time to sue, since you have been warned.

--
WW aka Attila

[WW]

Re: [OT] Re: to guru : strange C++ operator behaviour

Howard wrote:[color=blue]
> "The compiler is allowed to do whatever it wants, including
> formatting your harddisk."
>
> This very explicitly is talking about an action by the compiler, and[/color]

No, it is not. The compiler makes the program. The program makes something
causing your hard drive to be formatted and your dog to have 7 puppies and
your mother-in-law to move in permanently with her 4 deaf friends. So no,
it did not. Honest.

--
WW aka Attila

[Jack Klein]

Re: [OT] Re: to guru : strange C++ operator behaviour

On 03 Oct 2003 17:13:36 GMT, "Howard" <alicebt@hotmai l.com> wrote in
comp.lang.c++:
[color=blue]
>
> "Mike Wahler" <mkwahler@mkwah ler.net> wrote in message
> news:AlZeb.1121 7$RW4.3023@news read4.news.pas. earthlink.net.. .[color=green]
> >
> > "Howard" <alicebt@hotmai l.com> wrote in message
> > news:blhlt1$qot @dispatch.conce ntric.net...[color=darkred]
> > >[/color]
> >[color=darkred]
> > > But regardless of what "undefined behavior" means in the standard, you[/color][/color]
> had[color=green][color=darkred]
> > > best not sell me a compiler that formats my hard drive if I screw up[/color]
> > simple[color=darkred]
> > > code like this...I know a good lawyer! :-)[/color]
> >
> > So if I sell you a chain saw, and due to your ignorance
> > you cut off your hand, you'll sue me? I suppose so.
> > Only in America. :-)
> >
> > -Mike
> >[/color]
>
> :-)
>
> Funny, but a bit ludicrous, Mike. If I buy a chain saw, I know it has the
> capability to cut off my hand (or anything else) if I abuse it. After all,
> it is DESIGNED to cut things off! However, writing a compiler that
> translates the standard's meaing of "undefined behavior" into "I can format
> his hard drive if I want" is an act of malice, or at least negligence, and
> would definitely be actionable in a court of law (and probably not just in
> the US either). Do you write programs that, if the user does not read and
> understand your user's manual correctly, will format their hard drive? If
> so, please let me know what products you produce so I can avoid them! :-)[/color]

Nonsense. Windows trashes many peoples hard drives, requiring a
reinstall at best, sometimes a reformat and reinstall. Have you tried
suing Microsoft?

--
Jack Klein
Home: http://JK-Technology.Com
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[WW]

Re: [OT] Re: to guru : strange C++ operator behaviour

Jack Klein wrote:[color=blue]
> Nonsense. Windows trashes many peoples hard drives, requiring a
> reinstall at best, sometimes a reformat and reinstall. Have you tried
> suing Microsoft?[/color]

US states did. And they are currently being sued for their lack of
security. If that goes well I am sure they will be sued for lack of
robustness.

--
WW aka Attila

[Andrew Koenig]

Re: [OT] Re: to guru : strange C++ operator behaviour

WW> The Ariane came down due to underfined behavior. I think it was
WW> worse than a formatted hard drive. :-(

I heard a talk a few years ago about the Ariane. According to that
talk, the Ariane came down because of overly aggressive range
checking. A component was showing a reading that was out of range,
which raised an exception. That exception should not have been
capable of occuring at that time, so the safety systems responded by
calling for self-destruct.

In fact, the exception was raised from a component that was used only
at the beginning of the launch, so it made no difference at the
time it happened. If the exception had simply been ignored, everything
would have been fine.

--
Andrew Koenig, ark@acm.org

[WW]

Re: [OT] Re: to guru : strange C++ operator behaviour

Andrew Koenig wrote:[color=blue][color=green]
>> The Ariane came down due to underfined behavior. I think it was
>> worse than a formatted hard drive. :-([/color]
>
> I heard a talk a few years ago about the Ariane. According to that
> talk, the Ariane came down because of overly aggressive range
> checking. A component was showing a reading that was out of range,
> which raised an exception. That exception should not have been
> capable of occuring at that time, so the safety systems responded by
> calling for self-destruct.
>
> In fact, the exception was raised from a component that was used only
> at the beginning of the launch, so it made no difference at the
> time it happened. If the exception had simply been ignored,
> everything would have been fine.[/color]

My mistake. Then it was the lack of "planned cell death". More subtle.

--
WW aka Attila

[Gene Wirchenko]

Re: [OT] Re: to guru : strange C++ operator behaviour

On Sat, 4 Oct 2003 15:58:05 GMT, Andrew Koenig <ark@acm.org> wrote:
[color=blue]
>WW> The Ariane came down due to underfined behavior. I think it was
>WW> worse than a formatted hard drive. :-(
>
>I heard a talk a few years ago about the Ariane. According to that
>talk, the Ariane came down because of overly aggressive range
>checking. A component was showing a reading that was out of range,
>which raised an exception. That exception should not have been
>capable of occuring at that time, so the safety systems responded by
>calling for self-destruct.[/color]

The exception was an overflow. It was not possible with the
Ariane-4, but the rocket in question was an Ariane-5. The code had
not been changed. Diagnostic data was sent to the main system which
interpreted it as data for navigation. As a result, some weird
navigation orders were executed. The rocket started to break up under
the stress, and the self-destruct was triggered.
[color=blue]
>In fact, the exception was raised from a component that was used only
>at the beginning of the launch, so it made no difference at the
>time it happened. If the exception had simply been ignored, everything
>would have been fine.[/color]

Actually, it was something that was no longer necessary. It had
been necessary in the Ariane-4 (in order to restart a launch quickly),
but was not needed in the Ariane-5.

Sincerely,

Gene Wirchenko