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 9CCB8388E83D; Tue,  9 Feb 2021 00:10:20 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9CCB8388E83D
From: "dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug preprocessor/96391] [10/11 Regression] internal compiler error:
 in linemap_compare_locations, at libcpp/line-map.c:1359
Date: Tue, 09 Feb 2021 00:10:20 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: preprocessor
X-Bugzilla-Version: 10.2.1
X-Bugzilla-Keywords: ice-on-valid-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: dmalcolm at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 10.3
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cc
Message-ID: <bug-96391-4-YVrXkQILne@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-96391-4@http.gcc.gnu.org/bugzilla/>
References: <bug-96391-4@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: Tue, 09 Feb 2021 00:10:20 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96391

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dmalcolm at gcc dot gnu.org

--- Comment #9 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
I tried reproducing this using the .ii file (albeit with trunk), but it's n=
ot
triggering for me.

(In reply to Michael Cronenworth from comment #0)
[...]
> When I compile it with '-save-temps' to get the preprocessed file no error
> occurs. No error occurs if I compile the preprocessed file either.

...which suggests to me that maybe this is in a diagnostic that relies on
re-reading the sources, such as -Wmisleading-indentation.

Alternatively, the crash is in linemap_compare_locations.  This is used by
linemap_location_before_p, which is used by -Wuninitialized and
-Wmaybe-uninitialized.

So those could be a few warnings to try disabling to see if we can narrow t=
his
down; try adding:
  -Wno-misleading-indentation
  -Wno-uninitialized
  -Wno-maybe-uninitialized
and see if one of those fixes it.

Michael: are you able to invoke the crashing command under gdb?  Adding
  -wrapper gdb,--args
to the g++ invocation will make it invoke cc1plus under the debugger, from
which you can get a backtrace.
  (gdb) run
  [...hopefully the process crashes...]
  (gdb) bt
and hopefully will shed light on where it's crashing.

Hope this is helpful=