[Bug middle-end/56977] gcc -Og incorrectly warns about 'constant zero length parameter'

["bastiaan at bjacques dot org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56977

Bastiaan Jacques <bastiaan at bjacques dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bastiaan at bjacques dot org

--- Comment #7 from Bastiaan Jacques <bastiaan at bjacques dot org> ---
The following program fd.cc:

#include <sys/select.h>

int some_socket = 0;

void
foo()
{
    fd_set fdset;
    struct timeval tval;

    FD_ZERO(&fdset);
    FD_SET(some_socket, &fdset);
}

When compiled with:

g++ -c -o fd.o fd.cc  -D_FORTIFY_SOURCE=2  -Og

Generates the following warning:

fd.cc:12:219: warning: call to ‘__fdelt_warn’ declared with attribute warning:
bit outside of fd_set selected [enabled by default]
     FD_SET(some_socket, &fdset);

I think this might be another instance of this bug, because it goes away when
switching to -O2 (but I don't have a 4.8 branch handy to test whether the fix
also resolved this case).
>From gcc-bugs-return-425890-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Sun Jul 07 23:15:56 2013
Return-Path: <gcc-bugs-return-425890-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Delivered-To: listarch-gcc-bugs@gcc.gnu.org
Received: (qmail 29944 invoked by alias); 7 Jul 2013 23:15:55 -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
Delivered-To: mailing list gcc-bugs@gcc.gnu.org
Received: (qmail 29912 invoked by uid 48); 7 Jul 2013 23:15:52 -0000
From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/57842] for statement not terminating properly
Date: Sun, 07 Jul 2013 23:15:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 4.6.3
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: redi at gcc dot gnu.org
X-Bugzilla-Status: RESOLVED
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: <bug-57842-4-Atq0wIpbrQ@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-57842-4@http.gcc.gnu.org/bugzilla/>
References: <bug-57842-4@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: 2013-07/txt/msg00397.txt.bz2
Content-length: 255

http://gcc.gnu.org/bugzilla/show_bug.cgi?idW842

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
http://www.codinghorror.com/blog/2008/03/the-first-rule-of-programming-its-always-your-fault.html

select isn't broken, neither is 'for'