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|
(* TEST_BELOW
(* Blank lines added here to preserve locations. *)
*)
(* A test for stack backtraces *)
let get_backtrace () =
let raw_backtrace = Printexc.get_raw_backtrace () in
let raw_slots =
Array.init (Printexc.raw_backtrace_length raw_backtrace)
(Printexc.get_raw_backtrace_slot raw_backtrace) in
let convert = Printexc.convert_raw_backtrace_slot in
let backtrace = Array.map convert raw_slots in
(* we'll play with raw slots a bit to check that hashing and comparison work:
- create a hashtable that maps slots to their index in the raw backtrace
- create a balanced set of all slots
*)
let table = Hashtbl.create 100 in
Array.iteri (fun i slot -> Hashtbl.add table slot i) raw_slots;
let module S = Set.Make(struct
type t = Printexc.raw_backtrace_slot
let compare = Stdlib.compare
end) in
let slots = Array.fold_right S.add raw_slots S.empty in
Array.iteri (fun i slot ->
assert (S.mem slot slots);
assert (Hashtbl.mem table slot);
let j =
(* position in the table of the last slot equal to [slot] *)
Hashtbl.find table slot in
assert (slot = raw_slots.(j));
assert (backtrace.(i) = backtrace.(j));
) raw_slots;
backtrace
exception Error of string
let rec f msg n =
if n = 0 then raise(Error msg) else 1 + f msg (n-1)
let g msg =
try
f msg 5
with Error "a" -> print_string "a"; print_newline(); 0
| Error "b" as exn -> print_string "b"; print_newline(); raise exn
| Error "c" -> raise (Error "c")
let run args =
try
ignore (g args.(0)); print_string "No exception\n"
with exn ->
Printf.printf "Uncaught exception %s\n" (Printexc.to_string exn);
get_backtrace () |> Array.iteri
(fun i slot -> match Printexc.Slot.format i slot with
| None -> ()
| Some line -> print_endline line)
let _ =
run [| "a" |];
run [| "b" |];
run [| "c" |];
run [| "d" |];
run [| |]
(* TEST
flags = "-g";
ocamlrunparam += ",b=1";
*)
|
