From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-467694-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 12943 invoked by alias); 20 Nov 2014 10:22:40 -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 12886 invoked by uid 48); 20 Nov 2014 10:22:37 -0000
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug bootstrap/63888] [5 Regression] bootstrap failed when configured with -with-build-config=bootstrap-asan --disable-werror
Date: Thu, 20 Nov 2014 10:22:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: bootstrap
X-Bugzilla-Version: 5.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 5.0
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-63888-4-1OWoz2hx9r@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-63888-4@http.gcc.gnu.org/bugzilla/>
References: <bug-63888-4@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: 2014-11/txt/msg02166.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63888

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Kostya Serebryany from comment #6)
> (In reply to Yury Gribov from comment #5)
> > Perhaps ODR check should check that names of global variables match before
> > issuing warning?
> 
> The variables are generated by the compiler, right? 
> (These are switch tables)
> 
> Do we want to instrument them at all? 

Generally, we do want to instrument even artificial variables, and on many of
them buffer overflow is possible.

> I.e. is a buffer overflow on these variables possible? 
> 
> If we don't instrument them we won't report an ODR violation. 
> 
> >> GCC with -fmerge-all-constants also merges many read-only constants, even addressable ones, when they have the same content.
> 
> Then I guess we may have other false positives. 
> We may want to disable -fmerge-all-constants under asan

You haven't responded about the language thing, there is no such thing as ODR
in C or Fortran, so you shouldn't report it.
There are 31 (or 63) bits left in __has_dynamic_init field, can't one bit be
used for whether ODR should be reported or not?