From: Segher Boessenkool <segher@kernel.crashing.org>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Alexander Monakov <amonakov@ispras.ru>,
Eduard-Mihai Burtescu <eddyb@lyken.rs>,
Ian Lance Taylor <iant@google.com>,
gcc-patches <gcc-patches@gcc.gnu.org>,
Ian Lance Taylor <ian@airs.com>
Subject: Re: [PATCH] Refactor rust-demangle to be independent of C++ demangling.
Date: Wed, 23 Oct 2019 17:43:00 -0000 [thread overview]
Message-ID: <20191023174132.GQ28442@gate.crashing.org> (raw)
In-Reply-To: <20191023172848.GH2116@tucnak>
On Wed, Oct 23, 2019 at 07:28:48PM +0200, Jakub Jelinek wrote:
> On Wed, Oct 23, 2019 at 12:19:10PM -0500, Segher Boessenkool wrote:
> > I of course know that for e.g. strcmp or strlen we need to be careful of
> > page crossings; but this is strncmp, which has a size argument saying the
> > size of the array objects of its arguments!
>
> https://pubs.opengroup.org/onlinepubs/009695399/functions/strncmp.html
> The strncmp() function shall compare not more than n bytes
> (bytes that follow a null byte are not compared)
> from the array pointed to by s1 to the array pointed to by s2.
>
> In particular the second line.
>
> Similarly C11 7.24.4.4:
> The strncmp function compares not more than n characters (characters that follow a
> null character are not compared) from the array pointed to by s1 to the array pointed to
> by s2.
>
> Similarly C99.
Yes, and that does not say you cannot read more characters. It also does
not say it compares the strings pointed to, it explicitly says characters
from the array pointed to.
Segher
next prev parent reply other threads:[~2019-10-23 17:41 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-22 18:24 Eduard-Mihai Burtescu
2019-10-22 18:48 ` Ian Lance Taylor via gcc-patches
2019-10-23 14:29 ` Eduard-Mihai Burtescu
2019-10-23 16:37 ` Alexander Monakov
2019-10-23 16:41 ` Segher Boessenkool
2019-10-23 17:19 ` Jakub Jelinek
2019-10-23 17:29 ` Segher Boessenkool
2019-10-23 17:37 ` Jakub Jelinek
2019-10-23 17:43 ` Segher Boessenkool [this message]
2019-10-25 12:46 ` Eduard-Mihai Burtescu
2019-10-30 16:56 ` Eduard-Mihai Burtescu
2019-11-08 17:02 ` Eduard-Mihai Burtescu
2019-11-08 17:44 ` Ian Lance Taylor via gcc-patches
2019-11-08 19:17 ` Eduard-Mihai Burtescu
2019-11-08 19:23 ` Ian Lance Taylor via gcc-patches
2019-11-15 21:00 ` Eduard-Mihai Burtescu
2019-11-16 15:39 ` Jeff Law
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