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 419D0383543A; Sat, 13 Mar 2021 16:49:02 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 419D0383543A
From: "wsnyder at wsnyder dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/99579] New: gmon.out not created with -O0 but otherwise is
Date: Sat, 13 Mar 2021 16:49:01 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 9.3.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: wsnyder at wsnyder dot org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
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: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
 attachments.created
Message-ID: <bug-99579-4@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, 13 Mar 2021 16:49:02 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99579

            Bug ID: 99579
           Summary: gmon.out not created with -O0 but otherwise is
           Product: gcc
           Version: 9.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: wsnyder at wsnyder dot org
  Target Milestone: ---

Created attachment 50382
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D50382&action=3Dedit
Testcase

=3D=3D Description

Type "make" in this tarball's directory.

This will show (extra lines omitted):

  g++  -pg -O0  -c -o Vt_case_huge_prof__main.o Vt_case_huge_prof__main.ii
  @@@@@ Did we get a gmon?
  make: [Makefile:15: x] Error 1 (ignored)

  g++  -pg -Os  -c -o Vt_case_huge_prof__main.o Vt_case_huge_prof__main.ii
  @@@@@ Did we get a gmon?
    4554816     28 -rw-rw-r--   1 user  user     26943 Mar 13 11:33 ./gmon.=
out

  g++  -pg -O0  -c -o Vt_case_huge_prof__main.o Vt_case_huge_prof__main__ok=
.ii
  @@@@@ Did we get a gmon?
    4554816    884 -rw-rw-r--   1 user  user    897414 Mar 13 11:33 ./gmon.=
out


In short gcc -pg with -O0 is not creating a gmon.

The problem goes away using -Os.

The problem goes away if line 60549 of ~/d/case/Vt_case_huge_prof__main.ii

    std::array<CData , 16384> __Vtablechg1;

is changed into

    CData __Vtablechg1[16384];

(The original program requires a unique class, not a std::array, so using
C-style arrays is unfortunately not a workaround in my application.)

While this "feels" like a memory corruption sort of bug,=20
the program is sanitizer and warning clean.

=3D=3D gcc --version

gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

=3D=3D cat /etc/*release

DISTRIB_DESCRIPTION=3D"Ubuntu 20.04 LTS"=