From: Sergei Organov <osv@javad.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "J.A. Magallón" <jamagallon@ono.com>,
"Jan Engelhardt" <jengelh@linux01.gwdg.de>,
"Jeff Garzik" <jeff@garzik.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: Re: somebody dropped a (warning) bomb
Date: Mon, 12 Feb 2007 14:12:28 +0300 [thread overview]
Message-ID: <874pprr5nn.fsf@javad.com> (raw)
In-Reply-To: Pine.LNX.4.64.0702090753500.8424@woody.linux-foundation.org
Linus Torvalds <torvalds@linux-foundation.org> writes:
> On Fri, 9 Feb 2007, Sergei Organov wrote:
>>
>> As far as I can read the C99 standard, the "char", "signed char", and
>> "unsigned char", are all different types:
>
> Indeed. Search for "pseudo-unsigned", and you'll see more. There are
> actually cases where "char" can act differently from _both_ "unsigned
> char" and "signed char".
>
>> If so, then the code above is broken no matter what representation of
>> "char" is chosen for given arch, as strcmp() takes "char*" arguments,
>> that are not compatible with either "signed char*" or "unsigned char*".
>
> ..and my argument is that a warning which doesn't allow you to call
> "strlen()" on a "unsigned char" array without triggering is a bogus
> warning, and must be removed.
Why strlen() should be allowed to be called with an incompatible pointer
type? My point is that gcc should issue *different warning*, -- the same
warning it issues here:
$ cat incompat.c
void foo(int *p);
void boo(long *p) { foo(p); }
$ gcc -W -Wall -c incompat.c
incompat.c:2: warning: passing argument 1 of 'foo' from incompatible pointer type
Calling strlen(char*) with "unsigned char*" argument does pass argument
of incompatible pointer type due to the fact that in C "char" and
"unsigned char" are two incompatible types, and it has nothing to do
with signedness.
[...]
-- Sergei.
next prev parent reply other threads:[~2007-02-12 11:13 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-08 15:00 somebody dropped a (warning) bomb Jeff Garzik
2007-02-08 16:33 ` Linus Torvalds
2007-02-08 18:42 ` Jan Engelhardt
2007-02-08 19:53 ` Linus Torvalds
2007-02-08 21:10 ` Jan Engelhardt
2007-02-08 21:37 ` Linus Torvalds
2007-02-08 23:12 ` David Rientjes
2007-02-08 23:37 ` Linus Torvalds
2007-02-09 0:24 ` David Rientjes
2007-02-09 0:42 ` Linus Torvalds
2007-02-09 0:59 ` Linus Torvalds
2007-02-09 0:59 ` David Rientjes
2007-02-09 1:11 ` Linus Torvalds
2007-02-09 1:18 ` David Rientjes
2007-02-09 15:38 ` Linus Torvalds
2007-02-09 3:27 ` D. Hazelton
2007-02-09 19:54 ` Pete Zaitcev
2007-02-09 12:34 ` Jan Engelhardt
2007-02-09 13:16 ` linux-os (Dick Johnson)
2007-02-09 17:45 ` Jan Engelhardt
2007-02-09 20:29 ` linux-os (Dick Johnson)
2007-02-09 22:05 ` Jan Engelhardt
2007-02-09 22:58 ` Martin Mares
2007-02-12 18:50 ` linux-os (Dick Johnson)
2007-02-13 15:14 ` Dick Streefland
2007-02-08 21:13 ` J.A. Magallón
2007-02-08 21:42 ` Linus Torvalds
2007-02-08 22:03 ` Linus Torvalds
2007-02-08 22:19 ` Willy Tarreau
2007-02-09 0:03 ` J.A. Magallón
2007-02-09 0:22 ` Linus Torvalds
2007-02-09 12:38 ` Sergei Organov
2007-02-09 15:58 ` Linus Torvalds
2007-02-12 11:12 ` Sergei Organov [this message]
2007-02-12 16:26 ` Linus Torvalds
2007-02-13 18:06 ` Sergei Organov
2007-02-13 18:26 ` Pekka Enberg
2007-02-13 19:14 ` Sergei Organov
2007-02-13 19:43 ` Pekka Enberg
2007-02-13 20:29 ` Sergei Organov
2007-02-13 21:31 ` Jeff Garzik
2007-02-13 23:21 ` Linus Torvalds
2007-02-15 13:20 ` Sergei Organov
2007-02-15 15:57 ` Linus Torvalds
2007-02-15 18:53 ` Sergei Organov
2007-02-15 19:02 ` Linus Torvalds
2007-02-15 20:23 ` me, not " Oleg Verych
2007-02-16 4:26 ` Rene Herman
2007-02-19 11:58 ` Sergei Organov
2007-02-19 13:58 ` Sergei Organov
2007-02-15 22:32 ` Lennart Sorensen
2007-02-13 19:25 ` Linus Torvalds
2007-02-13 19:59 ` Sergei Organov
2007-02-13 20:24 ` Linus Torvalds
2007-02-15 15:15 ` Sergei Organov
2007-02-13 21:13 ` Rob Landley
2007-02-13 22:21 ` Olivier Galibert
2007-02-14 12:52 ` Sergei Organov
2007-02-15 20:06 ` Sergei Organov
2007-02-09 15:10 ` Sergei Organov
2007-02-08 16:35 ` Kumar Gala
[not found] <7Mj5f-3oz-21@gated-at.bofh.it>
[not found] ` <7MktH-5EW-35@gated-at.bofh.it>
[not found] ` <7Mmvy-vj-17@gated-at.bofh.it>
[not found] ` <7MnBC-2fk-13@gated-at.bofh.it>
[not found] ` <7MoQx-4p8-11@gated-at.bofh.it>
[not found] ` <7MpjE-50z-7@gated-at.bofh.it>
[not found] ` <7MpCS-5Fe-9@gated-at.bofh.it>
[not found] ` <7MDd7-17w-1@gated-at.bofh.it>
[not found] ` <7MGkB-62k-31@gated-at.bofh.it>
[not found] ` <7NHoe-2Mb-37@gated-at.bofh.it>
[not found] ` <7NMe9-1ZN-7@gated-at.bofh.it>
[not found] ` <7Oagl-6bO-1@gated-at.bofh.it>
[not found] ` <7ObvW-89N-23@gated-at.bofh.it>
[not found] ` <7Oc8t-NS-1@gated-at.bofh.it>
2007-02-15 20:08 ` Bodo Eggert
2007-02-16 11:21 ` Sergei Organov
2007-02-16 14:51 ` Bodo Eggert
2007-02-19 11:56 ` Sergei Organov
2007-02-16 12:46 ` Sergei Organov
2007-02-16 17:40 ` Bodo Eggert
2007-02-19 12:17 ` Sergei Organov
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