[Patch, fortran] PR37735 - Allocatable components in vectors of derived types cause ICE on assignment

["Paul Richard Thomas" <paul dot richard dot thomas at gmail dot com>]

The following testcase (which is now alloc_comp_assign_7.f90), would
ICE in the assignment to 'p' because structure_alloc_comps failed to
recognise that the array component 'r' is descriptorless.  I have
absolutely no idea how Erik and I managed to miss this sort of derived
type in our testsuite case - I guess that there are just too many
possible combinations.

! { dg-do run }
!
! Test the fix for PR37735, in which gfc gagged in the assignement to
! 'p'.  The array component 'r' caused an ICE.
!
! Contributed by Steven Winfield <saw44@cam.ac.uk>
!
module PrettyPix_module
  implicit none
  type Spline
     real, allocatable, dimension(:) ::y2
  end type Spline
  type Path
     type(Spline) :: r(3)
  end type Path
  type Scene
     type(path) :: look_at_path
  end type Scene
contains
  subroutine scene_set_look_at_path(this,p)
    type(scene), intent(inout) :: this
    type(path),  intent(in)    :: p
    this%look_at_path = p
  end subroutine scene_set_look_at_path
end module PrettyPix_module

  use PrettyPix_module
  implicit none
  integer :: i
  real :: x(3) = [1.0, 2.0, 3.0]
  type(scene) :: this
  type(path)  :: p
  p = path ([spline([x(1)]),spline([x(2)]),spline([x(3)])])
  call scene_set_look_at_path(this,p)
  do i = 1, 3
    if (this%look_at_path%r(i)%y2(1) .ne. x(i)) call abort
  end do
end

! { dg-final { cleanup-modules "PrettyPix_module" } }

I would have applied the fix as 'obvious' were we not in regression
only mode.  I think that this ice-on-invalid is sufficiently serious
that it should be fixed right away on trunk and 4.3.

Bootstrapped and regtested on FC9/x86_i64

OK for trunk and 4.3?

Paul

2008-11-08  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/37735
	* trans-array.c (structure_alloc_comps): Do not duplicate the
	descriptor if this is a descriptorless array!

2008-11-08  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/37735
	* gfortran.dg/alloc_comp_assign_7.f90: New test.

Index: gcc/fortran/trans-array.c
===================================================================
--- gcc/fortran/trans-array.c	(revision 142033)
+++ gcc/fortran/trans-array.c	(working copy)
@@ -5543,10 +5543,12 @@
 
       if (purpose == COPY_ALLOC_COMP)
         {
-          tmp = gfc_duplicate_allocatable (dest, decl, TREE_TYPE(decl), rank);
-	  gfc_add_expr_to_block (&fnblock, tmp);
-
-	  tmp = build_fold_indirect_ref (gfc_conv_descriptor_data_get (dest));
+	  if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (dest)))
+	    {
+	      tmp = gfc_duplicate_allocatable (dest, decl, TREE_TYPE(decl), rank);
+	      gfc_add_expr_to_block (&fnblock, tmp);
+	    }
+	  tmp = build_fold_indirect_ref (gfc_conv_array_data (dest));
 	  dref = gfc_build_array_ref (tmp, index, NULL);
 	  tmp = structure_alloc_comps (der_type, vref, dref, rank, purpose);
 	}