public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/108646] nonnull attribute does not detect variables that are NULL being passed
Date: Fri, 03 Feb 2023 17:58:50 +0000	[thread overview]
Message-ID: <bug-108646-4-GcXQdfGln7@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-108646-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108646

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonny Grant from comment #3)
> Is it worth -Wnonnull emitting a warning message that it needs optimization
> to get the needed data flow analysis?

No, there are dozens of warnings that work poorly, or not at all, unless
optimization is enabled. It's in the manual.

"The effectiveness of some warnings depends on optimizations also being
enabled. For example -Wsuggest-final-types is more effective with link-time
optimization and some instances of other warnings may not be issued at all
unless optimization is enabled. While optimization in general improves the
efficacy of control and data flow sensitive warnings, in some cases it may also
cause false positives."

  parent reply	other threads:[~2023-02-03 17:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-02 21:00 [Bug c++/108646] New: " jg at jguk dot org
2023-02-02 22:26 ` [Bug c++/108646] " pinskia at gcc dot gnu.org
2023-02-03  9:23 ` redi at gcc dot gnu.org
2023-02-03 12:08 ` jg at jguk dot org
2023-02-03 17:58 ` redi at gcc dot gnu.org [this message]
2023-02-07 12:19 ` jg at jguk 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=bug-108646-4-GcXQdfGln7@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).