open! Core
open! Async

(* JITed languages like java and javascript can write perf map files which provide a mapping of
   address to symbol name.

   They're documented here:

   https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt

   Like perf, magic-trace will automatically detect and load these maps, if available, and use them
   for symbol resolution. *)
type t

val default_filename : pid:Pid.t -> Filename.t

(* Returns `None` if there is no perf-map file in /tmp. *)
val load : Filename.t -> t option Deferred.t

(* Looks up an address, returning the function that address is for. Returns `None` if that address
   is not in the perf-map file. *)
val symbol : t -> addr:int64 -> Perf_map_location.t option

(** Load multiple perf maps in a table. Used when tracing multiple PIDs. *)
module Table : sig
  type t

  (** Uses default filenames for PID of [/tmp/perf-%{pid}.map]. Ignores perf maps which
      don't exist. *)
  val load_by_pids : Pid.t list -> t Deferred.t

  (** Requires filenames to be in [perf-%{pid}.map] format in order to infer PIDs and
      raises if any filename is not. Ignores perf maps which don't exist. *)
  val load_by_files : Filename.t list -> t Deferred.t

  val symbol : t -> pid:Pid.t -> addr:int64 -> Perf_map_location.t option
end