`sig type t = Comment_start | Comment_not_end | Deprecated of string | Fragile_match of string | Partial_application | Labels_omitted of string list | Method_override of string list | Partial_match of string | Non_closed_record_pattern of string | Statement_type | Unused_match | Unused_pat | Instance_variable_override of string list | Illegal_backslash | Implicit_public_methods of string list | Unerasable_optional_argument | Undeclared_virtual_method of string | Not_principal of string | Without_principality of string | Unused_argument | Nonreturning_statement | Preprocessor of string | Useless_record_with | Bad_module_name of string | All_clauses_guarded | Unused_var of string | Unused_var_strict of string | Wildcard_arg_to_constant_constr | Eol_in_string | Duplicate_definitions of string * string * string * string | Multiple_definition of string * string * string | Unused_value_declaration of string | Unused_open of string | Unused_type_declaration of string | Unused_for_index of string | Unused_ancestor of string | Unused_constructor of string * bool * bool | Unused_extension of string * bool * bool | Unused_rec_flag | Name_out_of_scope of string * string list * bool | Ambiguous_name of string list * string list * bool | Disambiguated_name of string | Nonoptional_label of string | Open_shadow_identifier of string * string | Open_shadow_label_constructor of string * string | Bad_env_variable of string * string | Attribute_payload of string * string | Eliminated_optional_arguments of string list | No_cmi_file of string * string option | Bad_docstring of bool | Expect_tailcall | Fragile_literal_pattern | Misplaced_attribute of string | Duplicated_attribute of string | Inlining_impossible of string | Unreachable_case | Ambiguous_pattern of string list | No_cmx_file of string | Assignment_to_non_mutable_value val parse_options : bool -> string -> unit val is_active : Warnings.t -> bool val is_error : Warnings.t -> bool val defaults_w : string val defaults_warn_error : string val print : Format.formatter -> Warnings.t -> unit exception Errors of int val check_fatal : unit -> unit val reset_fatal : unit -> unit val help_warnings : unit -> unit type state val backup : unit -> Warnings.state val restore : Warnings.state -> unit end`