public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "mattias at virtutech dot se" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/22485] pointer +- integer is never NULL
Date: Fri, 15 Jul 2005 09:27:00 -0000 [thread overview]
Message-ID: <20050715091256.25764.qmail@sourceware.org> (raw)
In-Reply-To: <20050714131031.22485.mattias@virtutech.se>
------- Additional Comments From mattias at virtutech dot se 2005-07-15 09:12 -------
It could be made an option so the user can tell GCC whether to make
standard-conforming code go as fast as possible or if arithmetic on null
pointers (as a gcc extension, say) is needed. -fnull-pointer-arith?
(In reply to comment #13)
> Scanning a region of memory starting from zero, is not
> exactly the kind of thing never done in practice.
True, but that sort of code is already in danger, since GCC assumes that in
x = *p;
if (!p) shout();
the condition is never true (even if it is possible to read from location 0).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22485
next prev parent reply other threads:[~2005-07-15 9:13 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-14 13:10 [Bug c/22485] New: " mattias at virtutech dot se
2005-07-14 13:14 ` [Bug c/22485] " mattias at virtutech dot se
2005-07-14 13:14 ` pinskia at gcc dot gnu dot org
2005-07-14 13:19 ` falk at debian dot org
2005-07-14 13:45 ` dberlin at gcc dot gnu dot org
2005-07-14 13:46 ` falk at debian dot org
2005-07-14 15:19 ` gdr at integrable-solutions dot net
2005-07-14 15:21 ` gdr at integrable-solutions dot net
2005-07-14 16:03 ` falk at debian dot org
2005-07-14 19:38 ` Gabriel Dos Reis
2005-07-14 21:47 ` Falk Hueffner
2005-07-14 19:40 ` gdr at integrable-solutions dot net
2005-07-14 22:19 ` falk at debian dot org
2005-07-14 23:04 ` gdr at integrable-solutions dot net
2005-07-15 7:51 ` falk at debian dot org
2005-07-15 8:26 ` gdr at integrable-solutions dot net
2005-07-15 9:27 ` mattias at virtutech dot se [this message]
2005-07-15 10:35 ` gdr at integrable-solutions dot net
2005-07-15 11:42 ` pluto at agmk dot net
2005-07-15 14:25 ` falk at debian dot org
2005-07-15 15:02 ` gdr at integrable-solutions dot net
2005-07-15 15:21 ` falk at debian dot org
2005-07-15 15:54 ` mattias at virtutech dot se
2005-09-24 5:37 ` gdr at gcc dot gnu dot org
2005-09-24 9:39 ` falk at debian dot org
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20050715091256.25764.qmail@sourceware.org \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).