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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.lexbuf -> Parser.token) -> Lexing.lexbuf -> 'a
let wrap (parser : 'a parser) lexbuf : 'a =
try
Docstrings.init ();
Lexer.init ();
let ast = parser token lexbuf 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.implementation
and interface = wrap Parser.interface
and toplevel_phrase = wrap Parser.toplevel_phrase
and use_file = wrap Parser.use_file
and core_type = wrap Parser.parse_core_type
and expression = wrap Parser.parse_expression
and pattern = wrap Parser.parse_pattern
let module_type = wrap Parser.parse_module_type
let module_expr = wrap Parser.parse_module_expr
let longident = wrap Parser.parse_any_longident
let val_ident = wrap Parser.parse_val_longident
let constr_ident= wrap Parser.parse_constr_longident
let extended_module_path = wrap Parser.parse_mod_ext_longident
let simple_module_path = wrap Parser.parse_mod_longident
let type_ident = wrap Parser.parse_mty_longident
(* Error reporting for Syntaxerr *)
(* The code has been moved here so that one can reuse Pprintast.tyvar *)
let prepare_error err =
let open Syntaxerr in
match err with
| Unclosed(opening_loc, opening, closing_loc, closing) ->
Location.errorf
~loc:closing_loc
~sub:[
Location.msg ~loc:opening_loc
"This '%s' might be unmatched" opening
]
"Syntax error: '%s' expected" closing
| Expecting (loc, nonterm) ->
Location.errorf ~loc "Syntax error: %s expected." nonterm
| Not_expecting (loc, nonterm) ->
Location.errorf ~loc "Syntax error: %s not expected." nonterm
| Applicative_path loc ->
Location.errorf ~loc
"Syntax error: applicative paths of the form F(X).t \
are not supported when the option -no-app-func is set."
| Variable_in_scope (loc, var) ->
Location.errorf ~loc
"In this scoped type, variable %a \
is reserved for the local type %s."
Pprintast.tyvar var 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, s) ->
Location.errorf ~loc "invalid package type: %s" s
| Removed_string_set loc ->
Location.errorf ~loc
"Syntax error: strings are immutable, there is no assignment \
syntax for them.\n\
@{<hint>Hint@}: Mutable sequences of bytes are available in \
the Bytes module.\n\
@{<hint>Hint@}: Did you mean to use 'Bytes.set'?"
let () =
Location.register_error_of_exn
(function
| Syntaxerr.Error err -> Some (prepare_error err)
| _ -> None
)
|
