From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-475813-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 20938 invoked by alias); 2 Feb 2015 18:25:29 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 20825 invoked by uid 48); 2 Feb 2015 18:25:25 -0000
From: "sirl at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug sanitizer/64906] New: -fsanitize=integer-divide-by-zero creates false -Wmaybe-uninitialized warning
Date: Mon, 02 Feb 2015 18:25:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: sanitizer
X-Bugzilla-Version: 5.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: sirl at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
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: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter cc
Message-ID: <bug-64906-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-02/txt/msg00146.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64906

            Bug ID: 64906
           Summary: -fsanitize=integer-divide-by-zero creates false
                    -Wmaybe-uninitialized warning
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sirl at gcc dot gnu.org
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org

This testcase produces a false warning when compiled with -O2
-fsanitize=integer-divide-by-zero -Wmaybe-uninitialized:

struct s {
    __SIZE_TYPE__ size;
    unsigned int flags;
};

int testf(struct s * source)
{
    __SIZE_TYPE__ msize = 0;
    if ((source->flags & 88) ? (__SIZE_TYPE__) 43 * 8 : 0)
        msize = source->size / ((source->flags & 88) ? (__SIZE_TYPE__) 43 * 8:
0);
    return msize;
}

test.c: In function 'testf':
test.c:11:8: warning: 'iftmp.1' may be used uninitialized in this function
[-Wmaybe-uninitialized]
  msize = source->size / ((source->flags & 88) ? (__SIZE_TYPE__) 43 * 8: 0);
        ^