From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-491294-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 124032 invoked by alias); 2 Jul 2015 17:22:41 -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 123971 invoked by uid 48); 2 Jul 2015 17:22:37 -0000
From: "rsandifo at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug debug/66728] [5/6 Regression] CONST_WIDE_INT causes corrupted DWARF debug info
Date: Thu, 02 Jul 2015 17:22:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: debug
X-Bugzilla-Version: 5.1.1
X-Bugzilla-Keywords: wrong-debug
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rsandifo at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution:
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: rsandifo at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 5.2
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_status cf_reconfirmed_on assigned_to everconfirmed
Message-ID: <bug-66728-4-El3FrbdaoL@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-66728-4@http.gcc.gnu.org/bugzilla/>
References: <bug-66728-4@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: 2015-07/txt/msg00184.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66728

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-07-02
           Assignee|unassigned at gcc dot gnu.org      |rsandifo at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
(In reply to Ulrich Weigand from comment #1)
> A bit of debugging shows that what's going on here is this:
> 
> add_const_value_attribute is called with the following constant RTL:
> (const_wide_int 0x80000000000000000000000000000000)
>
> The routine then does:
>          add_AT_wide (die, DW_AT_const_value,
>                       std::make_pair (rtl, GET_MODE (rtl)));
> 
> Note that GET_MODE (rtl) is VOIDmode.  This apparently causes creation of a
> wide_int value with precision 0:
> {<wide_int_storage> = {val = {0, -9223372036854775808, 2}, len = 2,
> precision = 0}
> 
> This seems already wrong, but doesn't quite explain the inconsistent output.

Yeah, wide_ints shouldn't have precision 0.  I think the later problems
do follow from that, although like you say there is probably a disconnect
between the way the DIEs are handled as well.