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|
(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
(* Entry points in the parser *)
(* Skip tokens to the end of the phrase *)
let last_token = ref Parser.EOF
let token lexbuf =
let token = Lexer.token lexbuf in
last_token := token;
token
let rec skip_phrase lexbuf =
match token lexbuf with
| Parser.SEMISEMI | Parser.EOF -> ()
| _ -> skip_phrase lexbuf
| exception (Lexer.Error (Lexer.Unterminated_comment _, _)
| Lexer.Error (Lexer.Unterminated_string, _)
| Lexer.Error (Lexer.Reserved_sequence _, _)
| Lexer.Error (Lexer.Unterminated_string_in_comment _, _)
| Lexer.Error (Lexer.Illegal_character _, _)) ->
skip_phrase lexbuf
let maybe_skip_phrase lexbuf =
match !last_token with
| Parser.SEMISEMI | Parser.EOF -> ()
| _ -> skip_phrase lexbuf
type 'a parser = Lexing.position -> 'a Parser.MenhirInterpreter.checkpoint
let wrap (parser : 'a parser) ~ocaml_version lexbuf : 'a =
try
Docstrings.init ();
let keyword_edition =
Some (ocaml_version, [])
in
Lexer.init ?keyword_edition ();
let open Parser.MenhirInterpreter in
let rec fix_resume = function
| InputNeeded _ | Accepted _ | Rejected | HandlingError _ as cp -> cp
| Shifting (_, _, _) | AboutToReduce (_, _) as cp ->
fix_resume (resume ~strategy:`Simplified cp)
in
let rec offer_input lexbuf cp tok =
let ptok = Lexing.(tok, lexbuf.lex_start_p, lexbuf.lex_curr_p) in
match fix_resume (offer cp ptok) with
| InputNeeded _ as cp ->
offer_input lexbuf cp (token lexbuf)
| Accepted x -> Some x
| Rejected -> None
| Shifting (_, _, _) | AboutToReduce (_, _) ->
assert false
| HandlingError _ as cp' ->
match Lexer.try_disambiguate lexbuf tok with
| Some tok' -> offer_input lexbuf cp tok'
| None -> main_loop lexbuf cp'
and main_loop lexbuf = function
| InputNeeded _ as cp ->
offer_input lexbuf cp (token lexbuf)
| Accepted x -> Some x
| Rejected -> None
| Shifting (_, _, _) | AboutToReduce (_, _) | HandlingError _ as cp ->
main_loop lexbuf (resume ~strategy:`Simplified cp)
in
let ast =
match main_loop lexbuf (parser lexbuf.Lexing.lex_curr_p) with
| Some ast -> ast
| None -> raise Parsing.Parse_error
in
Parsing.clear_parser();
Docstrings.warn_bad_docstrings ();
last_token := Parser.EOF;
ast
with
| Lexer.Error(Lexer.Illegal_character _, _) as err
when !Location.input_name = "//toplevel//"->
skip_phrase lexbuf;
raise err
| Syntaxerr.Error _ as err
when !Location.input_name = "//toplevel//" ->
maybe_skip_phrase lexbuf;
raise err
| Parsing.Parse_error | Syntaxerr.Escape_error ->
let loc = Location.curr lexbuf in
if !Location.input_name = "//toplevel//"
then maybe_skip_phrase lexbuf;
raise(Syntaxerr.Error(Syntaxerr.Other loc))
(* We pass [--strategy simplified] to Menhir, which means that we wish to use
its "simplified" strategy for handling errors. When a syntax error occurs,
the current token is replaced with an [error] token. The parser then
continues shifting and reducing, as far as possible. After (possibly)
shifting the [error] token, though, the parser remains in error-handling
mode, and does not request the next token, so the current token remains
[error].
In OCaml's grammar, the [error] token always appears at the end of a
production, and this production always raises an exception. In such
a situation, the strategy described above means that:
- either the parser will not be able to shift [error],
and will raise [Parser.Error];
- or it will be able to shift [error] and will then reduce
a production whose semantic action raises an exception.
In either case, the parser will not attempt to read one token past
the syntax error. *)
let implementation = wrap Parser.Incremental.implementation
and interface = wrap Parser.Incremental.interface
and toplevel_phrase = wrap Parser.Incremental.toplevel_phrase
and use_file = wrap Parser.Incremental.use_file
and core_type = wrap Parser.Incremental.parse_core_type
and expression = wrap Parser.Incremental.parse_expression
and pattern = wrap Parser.Incremental.parse_pattern
let module_type = wrap Parser.Incremental.parse_module_type
let module_expr = wrap Parser.Incremental.parse_module_expr
let longident = wrap Parser.Incremental.parse_any_longident
let val_ident = wrap Parser.Incremental.parse_val_longident
let constr_ident= wrap Parser.Incremental.parse_constr_longident
let extended_module_path = wrap Parser.Incremental.parse_mod_ext_longident
let simple_module_path = wrap Parser.Incremental.parse_mod_longident
let type_ident = wrap Parser.Incremental.parse_mty_longident
(* Error reporting for Syntaxerr *)
(* The code has been moved here so that one can reuse Pprintast.tyvar *)
module Style = Misc.Style
let prepare_error err =
let open Syntaxerr in
match err with
| Unclosed(opening_loc, opening, closing_loc, closing) ->
Location.errorf
~loc:closing_loc
"Syntax error: %a expected" Style.inline_code closing
~sub:[
Location.msg ~loc:opening_loc
"This %a might be unmatched" Style.inline_code opening
]
| Expecting (loc, nonterm) ->
Location.errorf ~loc "Syntax error: %a expected."
Style.inline_code nonterm
| Not_expecting (loc, nonterm) ->
Location.errorf ~loc "Syntax error: %a not expected."
Style.inline_code nonterm
| Applicative_path loc ->
Location.errorf ~loc
"Syntax error: applicative paths of the form %a \
are not supported when the option %a is set."
Style.inline_code "F(X).t"
Style.inline_code "-no-app-func"
| Variable_in_scope (loc, var) ->
Location.errorf ~loc
"In this scoped type, variable %a \
is reserved for the local type %a."
(Style.as_inline_code Pprintast.Doc.tyvar) var
Style.inline_code var
| Other loc ->
Location.errorf ~loc "Syntax error"
| Ill_formed_ast (loc, s) ->
Location.errorf ~loc
"broken invariant in parsetree: %s" s
| Invalid_package_type (loc, ipt) ->
let invalid ppf ipt = match ipt with
| Syntaxerr.Parameterized_types ->
Format_doc.fprintf ppf "parametrized types are not supported"
| Constrained_types ->
Format_doc.fprintf ppf "constrained types are not supported"
| Private_types ->
Format_doc.fprintf ppf "private types are not supported"
| Not_with_type ->
Format_doc.fprintf ppf "only %a constraints are supported"
Style.inline_code "with type t ="
| Neither_identifier_nor_with_type ->
Format_doc.fprintf ppf
"only module type identifier and %a constraints are supported"
Style.inline_code "with type"
in
Location.errorf ~loc "Syntax error: invalid package type: %a" invalid ipt
| Removed_string_set loc ->
Location.errorf ~loc
"Syntax error: strings are immutable,@ there@ is@ no@ assignment@ \
syntax@ for@ them."
~sub:[
Location.msg
"@{<hint>Hint@}: Mutable sequences of bytes are available in \
the %a module."
Style.inline_code "Bytes";
Location.msg
"@{<hint>Hint@}: Did you mean to use %a?"
Style.inline_code "Bytes.set"
]
let () =
Location.register_error_of_exn
(function
| Syntaxerr.Error err -> Some (prepare_error err)
| _ -> None
)
|
