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|
(***********************************************************************)
(* v * The Coq Proof Assistant / The Coq Development Team *)
(* <O___,, * INRIA-Rocquencourt & LRI-CNRS-Orsay *)
(* \VV/ *************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(***********************************************************************)
open Pp
(* spiwack: it might be reasonable to decide and move the declarations
of Anomaly and so on to this module so as not to depend on Util. *)
let handle_stack = ref []
exception Unhandled
let register_handler h = handle_stack := h::!handle_stack
(** [print_gen] is a general exception printer which tries successively
all the handlers of a list, and finally a [bottom] handler if all
others have failed *)
let rec print_gen bottom stk e =
match stk with
| [] -> bottom e
| h::stk' ->
try h e
with
| Unhandled -> print_gen bottom stk' e
| any -> print_gen bottom stk' any
(** Only anomalies should reach the bottom of the handler stack.
In usual situation, the [handle_stack] is treated as it if was always
non-empty with [print_anomaly] as its bottom handler. *)
let where s =
if !Flags.debug then str ("in "^s^":") ++ spc () else mt ()
let raw_anomaly e = match e with
| Util.Anomaly (s,pps) -> where s ++ pps ++ str "."
| Assert_failure _ | Match_failure _ -> str (Printexc.to_string e ^ ".")
| _ -> str ("Uncaught exception " ^ Printexc.to_string e ^ ".")
let print_anomaly askreport e =
if askreport then
hov 0 (str "Anomaly: " ++ raw_anomaly e ++ spc () ++ str "Please report.")
else
hov 0 (raw_anomaly e)
(** The standard exception printer *)
let print e = print_gen (print_anomaly true) !handle_stack e
(** Same as [print], except that the "Please report" part of an anomaly
isn't printed (used in Ltac debugging). *)
let print_no_report e = print_gen (print_anomaly false) !handle_stack e
(** Same as [print], except that anomalies are not printed but re-raised
(used for the Fail command) *)
let print_no_anomaly e = print_gen (fun e -> raise e) !handle_stack e
(** Predefined handlers **)
let _ = register_handler begin function
| Util.UserError(s,pps) -> hov 0 (str "Error: " ++ where s ++ pps)
| _ -> raise Unhandled
end
(** Critical exceptions shouldn't be catched and ignored by mistake
by inner functions during a [vernacinterp]. They should be handled
only at the very end of interp, to be displayed to the user. *)
(** NB: in the 8.4 branch, for maximal compatibility, anomalies
are considered non-critical *)
let noncritical = function
| Sys.Break | Out_of_memory | Stack_overflow -> false
| _ -> true
|
