Re: somebody dropped a (warning) bomb

From: Sergei Organov
Date: Tue Feb 13 2007 - 15:00:15 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
> On Tue, 13 Feb 2007, Sergei Organov wrote:
>> >
>> > "I want a char of indeterminate sign"!
>>
>> I'm afraid I don't follow. Do we have a way to say "I want an int of
>> indeterminate sign" in C? The same way there doesn't seem to be a way
>> to say "I want a char of indeterminate sign".
>
> You're wrong.

Sure, I knew it from the very beginning ;)

>
> Exactly because "char" *by*definition* is "indeterminate sign" as far as
> something like "strlen()" is concerned.

Thanks, I now understand that you either don't see the difference
between "indeterminate" and "implementation-defined" in this context or
consider it non-essential, so I think I've got your point.

> "char" is _special_. Char is _different_. Char is *not* "int".

Sure.

>
>> So no, strlen() doesn't actually say that, no matter if we like it or
>> not. It actually says "I want a char with implementation-defined sign".
>
> You're arguing some strange semantic difference in the English
> language.

Didn't I further explain what I meant exactly (that you've skipped)?
OK, never mind.

> I'm not really interested.

OK, no problem.

>
> THE FACT IS, THAT "strlen()" IS DEFINED UNIVERSALLY AS TAKING "char *".

So just don't pass it "unsigned char*". End of story.

>
> That BY DEFINITION means that "strlen()" cannot care about the sign,
> because the sign IS NOT DEFINED UNIVERSALLY!
>
> And if you cannot accept that fact, it's your problem. Not mine.

I never had problems either with strlen() or with this warning, so was
curious why does the warning is such a problem for the kernel. I'm sorry
I took your time and haven't got an answer that I entirely agree
with. Thank you very much for your explanations anyway.

> The warning is CRAP. End of story.

Amen!

-- Sergei.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/