ocaml/camlp4/Camlp4/ErrorHandler.ml

172 lines
6.2 KiB
OCaml

(****************************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* INRIA Rocquencourt *)
(* *)
(* Copyright 2006 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed under *)
(* the terms of the GNU Library General Public License, with the special *)
(* exception on linking described in LICENSE at the top of the Objective *)
(* Caml source tree. *)
(* *)
(****************************************************************************)
(* Authors:
* - Daniel de Rauglaudre: initial version
* - Nicolas Pouillard: refactoring
*)
(* camlp4r *)
open Format;
module ObjTools = struct
value desc obj =
if Obj.is_block obj then
"tag = " ^ string_of_int (Obj.tag obj)
else "int_val = " ^ string_of_int (Obj.obj obj);
(*Imported from the extlib*)
value rec to_string r =
if Obj.is_int r then
let i = (Obj.magic r : int)
in string_of_int i ^ " | CstTag" ^ string_of_int (i + 1)
else (* Block. *)
let rec get_fields acc =
fun
[ 0 -> acc
| n -> let n = n-1 in get_fields [Obj.field r n :: acc] n ]
in
let rec is_list r =
if Obj.is_int r then
r = Obj.repr 0 (* [] *)
else
let s = Obj.size r and t = Obj.tag r in
t = 0 && s = 2 && is_list (Obj.field r 1) (* h :: t *)
in
let rec get_list r =
if Obj.is_int r then []
else let h = Obj.field r 0 and t = get_list (Obj.field r 1) in [h :: t]
in
let opaque name =
(* XXX In future, print the address of value 'r'. Not possible in
* pure OCaml at the moment.
*)
"<" ^ name ^ ">"
in
let s = Obj.size r and t = Obj.tag r in
(* From the tag, determine the type of block. *)
match t with
[ _ when is_list r ->
let fields = get_list r in
"[" ^ String.concat "; " (List.map to_string fields) ^ "]"
| 0 ->
let fields = get_fields [] s in
"(" ^ String.concat ", " (List.map to_string fields) ^ ")"
| x when x = Obj.lazy_tag ->
(* Note that [lazy_tag .. forward_tag] are < no_scan_tag. Not
* clear if very large constructed values could have the same
* tag. XXX *)
opaque "lazy"
| x when x = Obj.closure_tag ->
opaque "closure"
| x when x = Obj.object_tag ->
let fields = get_fields [] s in
let (_class, id, slots) =
match fields with
[ [h; h'::t] -> (h, h', t)
| _ -> assert False ]
in
(* No information on decoding the class (first field). So just print
* out the ID and the slots. *)
"Object #" ^ to_string id ^ " (" ^ String.concat ", " (List.map to_string slots) ^ ")"
| x when x = Obj.infix_tag ->
opaque "infix"
| x when x = Obj.forward_tag ->
opaque "forward"
| x when x < Obj.no_scan_tag ->
let fields = get_fields [] s in
"Tag" ^ string_of_int t ^
" (" ^ String.concat ", " (List.map to_string fields) ^ ")"
| x when x = Obj.string_tag ->
"\"" ^ String.escaped (Obj.magic r : string) ^ "\""
| x when x = Obj.double_tag ->
string_of_float (Obj.magic r : float)
| x when x = Obj.abstract_tag ->
opaque "abstract"
| x when x = Obj.custom_tag ->
opaque "custom"
| x when x = Obj.final_tag ->
opaque "final"
| _ ->
failwith ("ObjTools.to_string: unknown tag (" ^ string_of_int t ^ ")") ];
value print ppf x = fprintf ppf "%s" (to_string x);
value print_desc ppf x = fprintf ppf "%s" (desc x);
end;
value default_handler ppf x = do {
let x = Obj.repr x;
fprintf ppf "Camlp4: Uncaught exception: %s"
(Obj.obj (Obj.field (Obj.field x 0) 0) : string);
if Obj.size x > 1 then do {
pp_print_string ppf " (";
for i = 1 to Obj.size x - 1 do {
if i > 1 then pp_print_string ppf ", " else ();
ObjTools.print ppf (Obj.field x i);
};
pp_print_char ppf ')'
}
else ();
fprintf ppf "@."
};
value handler = ref (fun ppf default_handler exn -> default_handler ppf exn);
value register f =
let current_handler = handler.val in
handler.val :=
fun ppf default_handler exn ->
try f ppf exn with exn -> current_handler ppf default_handler exn;
module Register (Error : Sig.Error.S) = struct
let current_handler = handler.val in
handler.val :=
fun ppf default_handler ->
fun [ Error.E x -> Error.print ppf x
| x -> current_handler ppf default_handler x ];
end;
value gen_print ppf default_handler =
fun
[ Out_of_memory -> fprintf ppf "Out of memory"
| Assert_failure (file, line, char) ->
fprintf ppf "Assertion failed, file %S, line %d, char %d"
file line char
| Match_failure (file, line, char) ->
fprintf ppf "Pattern matching failed, file %S, line %d, char %d"
file line char
| Failure str -> fprintf ppf "Failure: %S" str
| Invalid_argument str -> fprintf ppf "Invalid argument: %S" str
| Sys_error str -> fprintf ppf "I/O error: %S" str
| Stream.Failure -> fprintf ppf "Parse failure"
| Stream.Error str -> fprintf ppf "Parse error: %s" str
| x -> handler.val ppf default_handler x ];
value print ppf = gen_print ppf default_handler;
value try_print ppf = gen_print ppf (fun _ -> raise);
value to_string exn =
let buf = Buffer.create 128 in
let () = bprintf buf "%a" print exn in
Buffer.contents buf;
value try_to_string exn =
let buf = Buffer.create 128 in
let () = bprintf buf "%a" try_print exn in
Buffer.contents buf;