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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.

let none: t;

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

let is_none: t => bool;

True for Location.none, false any other location

let in_file: string => t;

Return an empty ghost range located in a given file.

let init: (Lexing.lexbuf, string) => unit;

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

let curr: Lexing.lexbuf => t;

Get the location of the current token from the lexbuf.

let symbol_rloc: unit => t;

let symbol_gloc: unit => t;

let rhs_loc: int => t;

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

let rhs_interval: (int, int) => t;

let get_pos_info: Lexing.position => (string, int, int);

file, line, char

type 'a loc = {
   txt : 'a;
   loc : t;
} 
let mknoloc: 'a => loc('a);

let mkloc: ('a, t) => loc('a);

Input info

let input_name: ref(string);

let input_lexbuf: ref(option(Lexing.lexbuf));

let input_phrase_buffer: ref(option(Buffer.t));

Toplevel-specific functions

let echo_eof: unit => unit;

let reset: unit => unit;

Printing locations

let 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.

let absolute_path: string => string;

let show_filename: string => string;

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

let print_filename: (Format.formatter, string) => unit;

let print_loc: (Format.formatter, t) => unit;

let print_locs: (Format.formatter, list(t)) => unit;

Toplevel-specific location highlighting

let highlight_terminfo: (Lexing.lexbuf, Format.formatter, list(t)) => unit;

Reporting errors and warnings

The type of reports and report printers

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

let msg: (~loc: t=?, format4('a, Format.formatter, unit, msg)) => 'a;

type report_kind =
| Report_error
| Report_warning of string
| Report_warning_as_error of string
| Report_alert of string
| Report_alert_as_error of string 
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

let batch_mode_printer: report_printer;

let terminfo_toplevel_printer: Lexing.lexbuf => report_printer;

let best_toplevel_printer: unit => report_printer;

Detects the terminal capabilities and selects an adequate printer

Printing a report

let print_report: (Format.formatter, report) => unit;

Display an error or warning report.

let report_printer: ref(unit => report_printer);

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.

let default_report_printer: unit => report_printer;

Original report printer for use in hooks.

Reporting warnings

Converting a Warnings.t into a report

let report_warning: (t, Warnings.t) => option(report);

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

let warning_reporter: ref((t, Warnings.t) => option(report));

Hook for intercepting warnings.

let default_warning_reporter: (t, Warnings.t) => option(report);

Original warning reporter for use in hooks.

Printing warnings

let formatter_for_warnings: ref(Format.formatter);

let print_warning: (t, Format.formatter, Warnings.t) => unit;

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

let prerr_warning: (t, Warnings.t) => unit;

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

Reporting alerts

Converting an Alert.t into a report

let report_alert: (t, Warnings.alert) => option(report);

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

let alert_reporter: ref((t, Warnings.alert) => option(report));

Hook for intercepting alerts.

let default_alert_reporter: (t, Warnings.alert) => option(report);

Original alert reporter for use in hooks.

Printing alerts

let print_alert: (t, Format.formatter, Warnings.alert) => unit;

Prints an alert. This is simply the composition of report_alert and print_report.

let prerr_alert: (t, Warnings.alert) => unit;

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

let deprecated: (~def: t=?, ~use: t=?, t, string) => unit;

Prints a deprecation alert.

let alert: (~def: t=?, ~use: t=?, ~kind: string, t, string) => unit;

Prints an arbitrary alert.

Reporting errors

type error = report;

An error is a report which report_kind must be Report_error.

let error: (~loc: t=?, ~sub: list(msg)=?, string) => error;

let errorf:
  (
    ~loc: t=?,
    ~sub: list(msg)=?,
    format4('a, Format.formatter, unit, error)
  ) =>
  'a;

let error_of_printer:
  (~loc: t=?, ~sub: list(msg)=?, (Format.formatter, 'a) => unit, 'a) => error;

let error_of_printer_file: ((Format.formatter, 'a) => unit, 'a) => error;

Automatically reporting errors for raised exceptions

let register_error_of_exn: (exn => option(error)) => 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).

let error_of_exn: exn => option([ | `Already_displayed | `Ok(error)]);

exception Error(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

let raise_errorf:
  (~loc: t=?, ~sub: list(msg)=?, format4('a, Format.formatter, unit, 'b)) =>
  'a;

let report_exception: (Format.formatter, exn) => unit;

Reraise the exception if it is unknown.