[Bug fortran/102689] Segfault with RESHAPE of CLASS as actual argument

["pault at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102689

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) = [(j, j=1,100)]
class(t), allocatable :: B(:,:,:), D(:)
allocate(t :: B(10,10,1))
B(:,:,:)%i = RESHAPE(src, shape(B))
D = reshape(B, [100])
call class_bar(D)

contains

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

Works as intended. Inspection of the original code reveals:
      atmp.19.dtype = {.elem_len=4, .rank=1, .type=5};
      atmp.19.dim[0].stride = 1;
      atmp.19.dim[0].lbound = 0;
      atmp.19.dim[0].ubound = 99;
      atmp.19.span = 4;
      atmp.19.data = (void * restrict) &A.20;
      atmp.19.offset = 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