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 D393B3855020; Sat, 10 Jul 2021 21:34:29 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D393B3855020
From: "toolybird at tuta dot io" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug go/101407] New: non-determinism in -fdump-go-spec
Date: Sat, 10 Jul 2021 21:34:29 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: go
X-Bugzilla-Version: 11.1.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: toolybird at tuta dot io
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ian at airs dot com
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 target_milestone
Message-ID: <bug-101407-4@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: Sat, 10 Jul 2021 21:34:29 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101407

            Bug ID: 101407
           Summary: non-determinism in -fdump-go-spec
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: toolybird at tuta dot io
                CC: cmang at google dot com
  Target Milestone: ---

I'm seeing a reproducibility issue when building gcc-go in GCC 11. Every bu=
ild
run produces a different binary.

I've narrowed down the test case to essentially this:

$ gcc -fdump-go-spec=3Dtmp-1.go -S -o sysinfo.s sysinfo.c
$ gcc -fdump-go-spec=3Dtmp-2.go -S -o sysinfo.s sysinfo.c

$ diff -u tmp-1.go tmp-2.go
--- tmp-1.go    2021-07-11 07:26:58.512916883 +1000
+++ tmp-2.go    2021-07-11 07:27:07.976340655 +1000
@@ -8519,10 +8519,10 @@
 const _PRIxFAST8 =3D "x"
 const ___POSIX_FADV_DONTNEED =3D 4
 const _IPPROTO_MTP =3D 92
-type ___dirstream struct {}
-type ___va_list_tag struct {}
 type _iface struct {}
 type ___locale_data struct {}
 type __IO_marker struct {}
 type __IO_codecvt struct {}
 type __IO_wide_data struct {}
+type ___dirstream struct {}
+type ___va_list_tag struct {}

The file in question is libgo/sysinfo.c

The output seems to differ each time. Occasionally it is the same.

This didn't happen with GCC 10. I suppose I should try the trunk but haven't
done so yet.

Any thoughts? Thanks.=