Module Location

module Location: sig .. end

Source code locations (ranges of positions), used in parsetree

Warning: this module is unstable and part of compiler-libs.

type t = Warnings.loc = {

	`loc_start : Lexing.position;`
	`loc_end : Lexing.position;`
	`loc_ghost : bool;`

}

Note on the use of Lexing.position in this module. If pos_fname = "", then use !input_name instead. If pos_lnum = -1, then pos_bol = 0. Use pos_cnum and re-parse the file to get the line and character numbers. Else all fields are correct.

val none : t

An arbitrary value of type t; describes an empty ghost range.

val in_file : string -> t

Return an empty ghost range located in a given file.

val init : Lexing.lexbuf -> string -> unit

Set the file name and line number of the lexbuf to be the start of the named file.

val curr : Lexing.lexbuf -> t

Get the location of the current token from the lexbuf.

val symbol_rloc : unit -> t

val symbol_gloc : unit -> t

val rhs_loc : int -> t

rhs_loc n returns the location of the symbol at position n, starting at 1, in the current parser rule.

val rhs_interval : int -> int -> t

val get_pos_info : Lexing.position -> string * int * int

file, line, char

type 'a loc = {

	`txt : 'a;`
	`loc : t;`

}

val mknoloc : 'a -> 'a loc

val mkloc : 'a -> t -> 'a loc

Input info

val input_name : string ref

val input_lexbuf : Lexing.lexbuf option ref

Toplevel-specific functions

val echo_eof : unit -> unit

val reset : unit -> unit

Printing locations

val rewrite_absolute_path : string -> string

rewrite absolute path to honor the BUILD_PATH_PREFIX_MAP variable (https://reproducible-builds.org/specs/build-path-prefix-map/) if it is set.

val absolute_path : string -> string

val show_filename : string -> string

In -absname mode, return the absolute path for this filename. Otherwise, returns the filename unchanged.

val print_filename : Format.formatter -> string -> unit

val print_loc : Format.formatter -> t -> unit

val print_locs : Format.formatter -> t list -> unit

Toplevel-specific location highlighting

val highlight_terminfo : Lexing.lexbuf -> Format.formatter -> t list -> unit

Reporting errors and warnings

The type of reports and report printers

type msg = (Format.formatter -> unit) loc

val msg : ?loc:t ->
       ('a, Format.formatter, unit, msg) format4 -> 'a

type report_kind =

`\|`	`Report_error`
`\|`	`Report_warning of int`
`\|`	`Report_warning_as_error of int`

type report = {

	`kind : report_kind;`
	`main : msg;`
	`sub : msg list;`

}

type report_printer = {

	`pp : report_printer -> Format.formatter -> report -> unit;`
	`pp_report_kind : report_printer -> report -> Format.formatter -> report_kind -> unit;`
	`pp_main_loc : report_printer -> report -> Format.formatter -> t -> unit;`
	`pp_main_txt : report_printer -> report -> Format.formatter -> (Format.formatter -> unit) -> unit;`
	`pp_submsgs : report_printer -> report -> Format.formatter -> msg list -> unit;`
	`pp_submsg : report_printer -> report -> Format.formatter -> msg -> unit;`
	`pp_submsg_loc : report_printer -> report -> Format.formatter -> t -> unit;`
	`pp_submsg_txt : report_printer -> report -> Format.formatter -> (Format.formatter -> unit) -> unit;`

}

A printer for reports, defined using open-recursion. The goal is to make it easy to define new printers by re-using code from existing ones.

Report printers used in the compiler

val batch_mode_printer : report_printer

val terminfo_toplevel_printer : Lexing.lexbuf -> report_printer

val best_toplevel_printer : unit -> report_printer

Detects the terminal capabilities and selects an adequate printer

Printing a `report`

val print_report : Format.formatter -> report -> unit

Display an error or warning report.

val report_printer : (unit -> report_printer) ref

Hook for redefining the printer of reports.

The hook is a unit -> report_printer and not simply a report_printer: this is useful so that it can detect the type of the output (a file, a terminal, ...) and select a printer accordingly.

val default_report_printer : unit -> report_printer

Original report printer for use in hooks.

Reporting warnings

Converting a `Warnings.t` into a `report`

val report_warning : t -> Warnings.t -> report option

report_warning loc w produces a report for the given warning w, or None if the warning is not to be printed.

val warning_reporter : (t -> Warnings.t -> report option) ref

Hook for intercepting warnings.

val default_warning_reporter : t -> Warnings.t -> report option

Original warning reporter for use in hooks.

Printing warnings

val formatter_for_warnings : Format.formatter ref

val print_warning : t -> Format.formatter -> Warnings.t -> unit

Prints a warning. This is simply the composition of report_warning and print_report.

val prerr_warning : t -> Warnings.t -> unit

Same as print_warning, but uses !formatter_for_warnings as output formatter.

val deprecated : ?def:t -> ?use:t -> t -> string -> unit

Prints a deprecation warning.

Reporting errors

type error = report

An error is a report which report_kind must be Report_error.

val error : ?loc:t -> ?sub:msg list -> string -> error

val errorf : ?loc:t ->
       ?sub:msg list ->
       ('a, Format.formatter, unit, error) format4 -> 'a

val error_of_printer : ?loc:t ->
       ?sub:msg list ->
       (Format.formatter -> 'a -> unit) -> 'a -> error

val error_of_printer_file : (Format.formatter -> 'a -> unit) -> 'a -> error

Automatically reporting errors for raised exceptions

val register_error_of_exn : (exn -> error option) -> unit

Each compiler module which defines a custom type of exception which can surface as a user-visible error should register a "printer" for this exception using register_error_of_exn. The result of the printer is an error value containing a location, a message, and optionally sub-messages (each of them being located as well).

val error_of_exn : exn -> [ `Already_displayed | `Ok of error ] option

exception Error of error

Raising Error e signals an error e; the exception will be caught and the error will be printed.

exception Already_displayed_error

Raising Already_displayed_error signals an error which has already been printed. The exception will be caught, but nothing will be printed

val raise_errorf : ?loc:t ->
       ?sub:msg list ->
       ('a, Format.formatter, unit, 'b) format4 -> 'a

val report_exception : Format.formatter -> exn -> unit

Reraise the exception if it is unknown.