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 BE6613858C2C; Sat, 15 Jan 2022 14:05:19 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BE6613858C2C
From: "fxcoudert at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug analyzer/104042] Four memcpy/memset analyzer failures on darwin
Date: Sat, 15 Jan 2022 14:05:19 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: analyzer
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: fxcoudert at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: dmalcolm at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status cf_reconfirmed_on cc everconfirmed
Message-ID: <bug-104042-4-ObKQBTiixE@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-104042-4@http.gcc.gnu.org/bugzilla/>
References: <bug-104042-4@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
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Sat, 15 Jan 2022 14:05:19 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104042

Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-01-15
                 CC|                            |dmalcolm at gcc dot gnu.or=
g,
                   |                            |iains at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> =
---
The reason for the failure is that the darwin headers, in <secure/_string.h>
(included from <string.h>), defines memcpy like this:

#if __has_builtin(__builtin___memcpy_chk) || defined(__GNUC__)
#undef memcpy
/* void *memcpy(void *dst, const void *src, size_t n) */
#define memcpy(dest, ...) \
               __builtin___memcpy_chk (dest, __VA_ARGS__, __darwin_obsz0
(dest))
#endif

where __darwin_obsz0 is defined thusly:

#define __darwin_obsz0(object) __builtin_object_size (object, 0)



So either the testcase should be modified to use __builtin_memcpy, or the
analyzer should handle __builtin___memcpy_chk and emit the right warning.=