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 2E71C3858D1E; Wed, 29 Nov 2023 10:35:10 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2E71C3858D1E
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1701254110;
	bh=6on39T5otKXiHhxOSOPePoBErM1FTaTfTOGUUXVVhuE=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=ZduQV8Ka/I84vn+cak+O7jPYOkazqajCTHrReEATpVi3AK2PW0kKIUIUg7UaVASJY
	 HxUb7zEIKd67BEkuKb+Om3e8nnSkjq7HPC0zICmxFPsLSSn2H5tV5uITw70lvlqvwf
	 NaBWOW+lBv7WW9QkelklyUqnCdpkbpA0SiRPaN58=
From: "pault at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/102689] Segfault with RESHAPE of CLASS as actual
 argument
Date: Wed, 29 Nov 2023 10:35:09 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: fortran
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pault at gcc dot gnu.org
X-Bugzilla-Status: NEW
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_status cf_reconfirmed_on cc everconfirmed
Message-ID: <bug-102689-4-cpaG8lDpMQ@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-102689-4@http.gcc.gnu.org/bugzilla/>
References: <bug-102689-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102689

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-11-29
                 CC|                            |pault at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Paul Thomas <pault at gcc dot gnu.org> ---
Confirmed!

implicit none (type, external)
type t
  integer :: i
end type t
integer :: j
integer :: src(100) =3D [(j, j=3D1,100)]
class(t), allocatable :: B(:,:,:), D(:)
allocate(t :: B(10,10,1))
B(:,:,:)%i =3D RESHAPE(src, shape(B))
D =3D reshape(B, [100])
call class_bar(D)

contains

subroutine class_bar(x)
  class(t), intent(in) :: x(:)
  integer :: k
  if (any (x(:)%i /=3D [(k, k=3D1,100)])) error stop 1
end
end

Works as intended. Inspection of the original code reveals:
      atmp.19.dtype =3D {.elem_len=3D4, .rank=3D1, .type=3D5};
      atmp.19.dim[0].stride =3D 1;
      atmp.19.dim[0].lbound =3D 0;
      atmp.19.dim[0].ubound =3D 99;
      atmp.19.span =3D 4;
      atmp.19.data =3D (void * restrict) &A.20;
      atmp.19.offset =3D 0;
      _gfortran_reshape (&atmp.19, D.4442, D.4451, 0B, 0B);
      class_bar (atmp.19);

ie. The class formal argument is being fed an array descriptor. This is a
problem with gfc_conv_procedure_call.

The discussion about inlining or not is for another day :-)

Thanks for the report, Tobias.

Paul=