`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 * 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
| Unused_module of string
| Unboxable_type_in_prim_decl of string
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`