From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 761D43858405; Fri, 17 Jun 2022 21:07:49 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 761D43858405 From: "matt at godbolt dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug lto/106020] Spurious warnings about stringop overflows only with LTO Date: Fri, 17 Jun 2022 21:07:49 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: lto X-Bugzilla-Version: 12.1.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: matt at godbolt dot org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Jun 2022 21:07:49 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106020 --- Comment #2 from Matt Godbolt --- There are many hundreds of similar errors in that example; perhaps this exa= mple is more of a clue: /opt/compiler-explorer/gcc-12.1.0/include/c++/12.1.0/bits/move.h:205:11: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=3D] 205 | __a =3D _GLIBCXX_MOVE(__b); (which seems very suspicious, size 0 inside std::move?)=