http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55978
--- Comment #7 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-01-15 14:47:31 UTC --- (In reply to comment #6) > Looks as if code of the form: > if (y.data) > D.1914 = _gfortran_internal_pack (&y); > else > D.1914 = NULL; > > is missing The bug is in trans-array.c's gfc_conv_array_parameter, which currently has: 7156 ptr = build_call_expr_loc (input_location, 7157 gfor_fndecl_in_pack, 1, desc); 7158 7159 if (fsym && fsym->attr.optional && sym && sym->attr.optional) 7160 { 7161 tmp = gfc_conv_expr_present (sym); If the actual argument has sym->attr.optional, the code should work. Looking at line 39 of class_optional_2.f90, there seems to be something not working, which might be a bug in gfc_conv_expr_present. If sym->attr.optional is not present, it is currently not handled by gfc_conv_expr_present (assert). Similarly, if the actual argument is an expression like "var%comp" - here, the ".data == NULL" check has to be done for "comp" and not for "var" alias "sym". Similarly for expressions instead of variables. (There are presumably more issues.)