https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87566
--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> ---
@Paul: Some guidance is welcome!
(In reply to Tobias Burnus from comment #2)
> For some odd reasons the gimplfier does not like that f951 assigns a value
> to the digit 0 (last but one line of the "finally") ...
That's in trans-expr.c's gfc_conv_class_to_class():
if (UNLIMITED_POLY (e))
tmp = gfc_class_len_get (tmp);
else if (e->ts.type == BT_CHARACTER)
tmp = slen;
else
tmp = build_zero_cst (size_type_node);
gfc_add_modify (&parmse->pre, ctree,
fold_convert (TREE_TYPE (ctree), tmp));
OK so far – now comes the finally part:
if (!elemental && full_array && copyback)
gfc_add_modify (&parmse->post, tmp,
fold_convert (TREE_TYPE (tmp), ctree));
And here we have assigned (if the "else" branch for tmp branch was taken) a
value to the build_zero_cst()!
Actually, I wonder whether the _len = 0 is needed. The current code is:
class.0._len = 0;
class.0._data =
__tmp_class_object_array_pointer->_data->p._data;
class.0._vptr =
__tmp_class_object_array_pointer->_data->p._vptr;
class.0._len = __tmp_class_object_array_pointer->_data->p._len;
i.e. we set _len twice. And also in finally, we have it also twice:
0 = (unsigned long) class.0._len;
__tmp_class_object_array_pointer->_data->p._len = class.0._len;
As band-aid the following works (on top of the patch from attachment 44831)
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -1133,3 +1133,3 @@ gfc_conv_class_to_class (gfc_se *parmse, gfc_expr *e,
gfc_typespec class_ts,
references, where the dynamic type cannot change. */
- if (!elemental && full_array && copyback)
+ if (!elemental && full_array && copyback && !INTEGER_CST_P (tmp))
gfc_add_modify (&parmse->post, tmp,
