From: Vadim Lobanov <vlobanov@speakeasy.net>
To: "Giacomo A. Catenazzi" <cate@cateee.net>
Cc: Jakob Oestergaard <jakob@unthought.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Schwartz <davids@webmaster.com>,
Johannes Weiner <hannes@saeurebad.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
clameter@sgi.com, penberg@cs.helsinki.fi
Subject: Re: Why is the kfree() argument const?
Date: Fri, 18 Jan 2008 11:06:08 -0800 [thread overview]
Message-ID: <200801181106.08511.vlobanov@speakeasy.net> (raw)
In-Reply-To: <479091B5.4060700@cateee.net>
On Friday 18 January 2008 03:47:01 am Giacomo A. Catenazzi wrote:
> Changing the name of variables in your example:
>
> extern print_int(const int *);
>
> int main(int argc, char **argv)
> {
> extern int errno;
>
> errno = 0;
> print_int(&i);
> return errno;
> }
Except that changing int to extern int makes all the difference in the world:
the variable went from being local to being global. The way const is
currently defined, however, the compiler cannot take advantage of the fact
that the variable was local in the former case.
> Ok, I changed int to extern int, but you see the point?
> Do you want complex rules about const, depending on
> context (extern, volatile,...) ?
Sometimes complexity is worth it.
-- Vadim Lobanov
next prev parent reply other threads:[~2008-01-18 19:06 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <MDEHLPKNGKAHNMBLJOLKIEGIJJAC.davids@webmaster.com>
2008-01-17 21:25 ` Why is the kfree() argument const? Linus Torvalds
2008-01-17 22:28 ` David Schwartz
2008-01-17 23:10 ` Linus Torvalds
2008-01-18 0:56 ` David Schwartz
2008-01-18 1:15 ` Linus Torvalds
2008-01-18 5:02 ` David Schwartz
2008-01-18 15:38 ` Chris Friesen
2008-01-18 16:10 ` Linus Torvalds
2008-01-18 20:55 ` David Schwartz
2008-01-18 17:37 ` Olivier Galibert
2008-01-18 18:06 ` DM
2008-01-18 7:51 ` Giacomo Catenazzi
2008-01-18 8:20 ` Giacomo Catenazzi
2008-01-18 13:53 ` Andy Lutomirski
2008-01-18 17:24 ` Olivier Galibert
2008-01-18 22:29 ` J.A. Magallón
2008-01-18 23:44 ` Krzysztof Halasa
2008-01-18 13:54 ` Andy Lutomirski
2008-01-18 19:14 ` Vadim Lobanov
2008-01-18 19:31 ` Zan Lynx
2008-01-18 19:55 ` Vadim Lobanov
2008-01-18 8:30 ` Vadim Lobanov
2008-01-18 9:48 ` Jakob Oestergaard
2008-01-18 11:47 ` Giacomo A. Catenazzi
2008-01-18 14:39 ` Jakob Oestergaard
2008-01-18 19:06 ` Vadim Lobanov [this message]
2008-01-18 13:31 ` Björn Steinbrink
2008-01-18 14:53 ` Jakob Oestergaard
[not found] <fa.cHMztHfqJXv7vw5O0nQ8SdTrma0@ifi.uio.no>
[not found] ` <fa.V9M+5l8C/um5KEiBtZOjbJDQmu4@ifi.uio.no>
2013-01-12 19:18 ` antoine.trux
2013-01-13 8:10 ` Chen Gang F T
2013-01-13 17:41 ` Guenter Roeck
2013-01-14 1:45 ` Chen Gang F T
2013-01-13 20:54 ` Cong Ding
2013-01-14 1:18 ` Chen Gang F T
2008-01-18 19:10 ecolbus
-- strict thread matches above, loose matches on Subject: below --
2008-01-18 16:45 ecolbus
2008-01-18 18:20 ` Olivier Galibert
2008-01-18 12:45 ecolbus
2008-01-18 15:20 ` Giacomo A. Catenazzi
2008-01-16 16:32 Johannes Weiner
2008-01-16 16:48 ` Christoph Lameter
2008-01-16 17:34 ` Bernd Petrovitsch
2008-01-16 17:45 ` Pekka J Enberg
2008-01-16 18:39 ` Linus Torvalds
2008-01-16 22:19 ` Johannes Weiner
2008-01-16 22:20 ` Christoph Lameter
2008-01-16 22:37 ` Johannes Weiner
2008-01-16 23:13 ` Johannes Weiner
2008-01-16 23:18 ` Linus Torvalds
2008-01-16 23:16 ` Linus Torvalds
2008-01-16 22:33 ` Steven Rostedt
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