From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 9A8E63858C2A; Wed,  6 Dec 2023 11:16:23 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9A8E63858C2A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1701861383;
	bh=um0rSEN9tLB7MQbCPKhVZzGHNP4KNrLcrdQq+oLU6G8=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=P//i1E+lHwn0Mw82gSc50ALaaM0wIGG8IDpDzCa5Tef852ukMJIUEvoP8w7AtJmvb
	 wMwBv3gKwLi5Fxwbs+F26JZSW9YD0PpSFZmI/TZD5h6xjM9/lJh/+0Q4jAGxNnUIe6
	 Fmg4Rb8kor8cyDH+gi6cCmQTteB3YMWbkm+/rr/E=
From: "sjames at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/105562] [12 Regression]
 std::function<bool(char)>::_M_invoker may be used uninitialized in std::regex
 move with -fno-strict-aliasing
Date: Wed, 06 Dec 2023 11:16:22 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 12.1.0
X-Bugzilla-Keywords: diagnostic, missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: sjames at gcc dot gnu.org
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Resolution: FIXED
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cc
Message-ID: <bug-105562-4-HMKTDABjxr@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-105562-4@http.gcc.gnu.org/bugzilla/>
References: <bug-105562-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105562

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sjames at gcc dot gnu.org

--- Comment #29 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Romain Geissler from comment #28)
> Ok it's clear. I haven't really played yet with sanitizers, I didn't know=
 it
> had these well known "issue" with creating more middle end false positive
> warnings (I am used to them in LTO mode).
>=20
> So I will advise that we relax warning severity/disable some warnings in =
my
> company when using sanitizers.
>=20
> Thanks !

See also
https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#index-fsani=
tize_003dbuiltin.

"Note that sanitizers tend to increase the rate of false positive warnings,
most notably those around -Wmaybe-uninitialized. We recommend against combi=
ning
-Werror and [the use of] sanitizers."=