public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/111615] NULL check incorrectly skipped at O2 and O3
Date: Wed, 27 Sep 2023 15:20:48 +0000	[thread overview]
Message-ID: <bug-111615-4-fX6xH5tVEv@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-111615-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111615

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
extern void *memmem (const void *__haystack, size_t __haystacklen,
       const void *__needle, size_t __needlelen)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__pure__))
__attribute__ ((__nonnull__ (1, 3)));


memmem is declared with nonnull for the 1st and 3rd argument. If those
arguments are null, the behavior is undefined and the values of those arguments
can be assumed as not null afterwards too.

If you don't want that behavior you can use -fno-delete-null-pointer-checks .

Otherwise the behavior you are seeing is correct behavior based on well defined
code.

  parent reply	other threads:[~2023-09-27 15:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-27 15:00 [Bug c/111615] New: " gardner.ben at gmail dot com
2023-09-27 15:02 ` [Bug c/111615] " gardner.ben at gmail dot com
2023-09-27 15:05 ` [Bug middle-end/111615] " pinskia at gcc dot gnu.org
2023-09-27 15:09 ` gardner.ben at gmail dot com
2023-09-27 15:11 ` redi at gcc dot gnu.org
2023-09-27 15:20 ` pinskia at gcc dot gnu.org [this message]
2023-09-27 15:25 ` gardner.ben at gmail dot com

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=bug-111615-4-fX6xH5tVEv@http.gcc.gnu.org/bugzilla/ \
    --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).