cdecl, NULL_TREE);
dcmp = fold_convert (TREE_TYPE (comp), dcmp);
+ if (c->ts.type == BT_CLASS && CLASS_DATA (c)->attr.allocatable)
+ {
+ tree ftn_tree;
+ tree size;
+ tree dst_data;
+ tree src_data;
+ tree null_data;
+
+ dst_data = gfc_class_data_get (dcmp);
+ src_data = gfc_class_data_get (comp);
+ size = fold_convert (size_type_node, gfc_vtable_size_get (comp));
+
+ if (CLASS_DATA (c)->attr.dimension)
+ {
+ nelems = gfc_conv_descriptor_size (src_data,
+ CLASS_DATA (c)->as->rank);
+ src_data = gfc_conv_descriptor_data_get (src_data);
+ dst_data = gfc_conv_descriptor_data_get (dst_data);
+ }
+ else
+ nelems = build_int_cst (size_type_node, 1);
+
+ gfc_init_block (&tmpblock);
+
+ /* We need to use CALLOC as _copy might try to free allocatable
+ components of the destination. */
+ ftn_tree = builtin_decl_explicit (BUILT_IN_CALLOC);
+ tmp = build_call_expr_loc (input_location, ftn_tree, 2, nelems,
+ size);
+ gfc_add_modify (&tmpblock, dst_data,
+ fold_convert (TREE_TYPE (dst_data), tmp));
+
+ tmp = gfc_copy_class_to_class (comp, dcmp, nelems);
+ gfc_add_expr_to_block (&tmpblock, tmp);
+ tmp = gfc_finish_block (&tmpblock);
+
+ gfc_init_block (&tmpblock);
+ gfc_add_modify (&tmpblock, dst_data,
+ fold_convert (TREE_TYPE (dst_data),
+ null_pointer_node));
+ null_data = gfc_finish_block (&tmpblock);
+
+ null_cond = fold_build2_loc (input_location, NE_EXPR,
+ boolean_type_node, src_data,
+ null_pointer_node);
+
+ gfc_add_expr_to_block (&fnblock, build3_v (COND_EXPR, null_cond,
+ tmp, null_data));
+ continue;
+ }
+
if (c->attr.allocatable && !cmp_has_alloc_comps)
{
rank = c->as ? c->as->rank : 0;
--- /dev/null
+! { dg-do run }
+!
+! PR fortran/51972
+!
+! Check whether DT assignment with polymorphic components works.
+!
+
+subroutine test1 ()
+ type t
+ integer :: x
+ end type t
+
+ type t2
+ class(t), allocatable :: a
+ end type t2
+
+ type(t2) :: one, two
+
+ one = two
+ if (allocated (one%a)) call abort ()
+
+ allocate (two%a)
+ two%a%x = 7890
+ one = two
+ if (one%a%x /= 7890) call abort ()
+
+ deallocate (two%a)
+ one = two
+ if (allocated (one%a)) call abort ()
+end subroutine test1
+
+subroutine test2 ()
+ type t
+ integer, allocatable :: x(:)
+ end type t
+
+ type t2
+ class(t), allocatable :: a
+ end type t2
+
+ type(t2) :: one, two
+
+ one = two
+ if (allocated (one%a)) call abort ()
+
+ allocate (two%a)
+ one = two
+ if (.not.allocated (one%a)) call abort ()
+ if (allocated (one%a%x)) call abort ()
+
+ allocate (two%a%x(2))
+ two%a%x(:) = 7890
+ one = two
+ if (any (one%a%x /= 7890)) call abort ()
+
+ deallocate (two%a)
+ one = two
+ if (allocated (one%a)) call abort ()
+end subroutine test2
+
+
+subroutine test3 ()
+ type t
+ integer :: x
+ end type t
+
+ type t2
+ class(t), allocatable :: a(:)
+ end type t2
+
+ type(t2) :: one, two
+
+ one = two
+ if (allocated (one%a)) call abort ()
+
+ allocate (two%a(2), source=[t(4), t(6)])
+ one = two
+ if (.not.allocated (one%a)) call abort ()
+! FIXME: Check value
+
+ deallocate (two%a)
+ one = two
+ if (allocated (one%a)) call abort ()
+end subroutine test3
+
+subroutine test4 ()
+ type t
+ integer, allocatable :: x(:)
+ end type t
+
+ type t2
+ class(t), allocatable :: a(:)
+ end type t2
+
+ type(t2) :: one, two
+
+ one = two
+ if (allocated (one%a)) call abort ()
+
+! allocate (two%a(2)) ! ICE: SEGFAULT
+! one = two
+! if (.not. allocated (one%a)) call abort ()
+end subroutine test4
+
+
+call test1 ()
+call test2 ()
+call test3 ()
+call test4 ()
+end