A simple symbolizer for caml-inspect.

README.md

Caml-inspect symbolizer

Symbolizes closure blocks. Works only on native executables.

Build

ocamlfind ocamlopt -syntax camlp4o -package lwt -package lwt.syntax -package lwt.unix str.cmxa -linkpkg symbolizer.ml -o symbolizer
ocamlfind ocamlopt -package inspect -linkpkg foo.ml -o foo

Use

./foo
./symbolizer -prog foo -graph test.dot -open okular

Examples

Before: http://i.imgur.com/Sk1cDEU.jpg

After: http://i.imgur.com/zghC3JM.jpg

foo.ml

open Inspect

let () =
  Dot.dump_to_file "test.dot" (Dot.test_data ());;

symbolizer.ml

open Lwt

let () =
  let executable = ref ""
  and graph_name = ref ""
  and dot_cmd    = ref "dot"
  and open_cmd   = ref "" in

  Arg.parse (Arg.align [
      "-prog",  Arg.Set_string executable, " Executable filename";
      "-graph", Arg.Set_string graph_name, " Dot graph filename";
      "-dot",   Arg.Set_string dot_cmd,    " Dot command";
      "-open",  Arg.Set_string open_cmd,   " Open command";
    ])
    (fun unknown ->
      Printf.eprintf "Extraneous argument %s\n" unknown;
      exit 1)
    (Printf.sprintf "Usage: %s -e foo.native -g graph.dot" Sys.argv.(0));

  Lwt_main.run (
    (* Read symbols. *)
    Lwt_process.pread_lines ("nm", [|"nm"; !executable|])
    |> Lwt_stream.map_list (fun symbol ->
      try
        Scanf.sscanf symbol "%x %c %s%!" (fun addr kind symbol ->
          match kind with
          | 'd' | 'D' | 't' | 'T' -> [addr, symbol]
          | _ -> [])
      with Scanf.Scan_failure _ ->
        [])
    |> Lwt_stream.to_list
    >>= fun symbols ->
    let hash = Hashtbl.create (List.length symbols) in
    List.iter (fun (addr, sym) -> Hashtbl.add hash addr sym) symbols;
    (* Read graph. *)
    lwt graph_file = Lwt_io.open_file ~mode:Lwt_io.input !graph_name in
    lwt graph      = Lwt_io.read graph_file in
    Lwt_io.close graph_file >>= fun () ->
    (* Replace symbols in graph. *)
    graph
    |> Str.global_substitute (Str.regexp "0x[0-9A-Z]+") (fun text ->
      let addr_str = Str.matched_string text in
      let addr     = Scanf.sscanf addr_str "0x%x%!" (fun x -> x) in
      try  Hashtbl.find hash addr
      with Not_found -> addr_str)
    |> fun graph' ->
    if !open_cmd = "" then begin
      (* Modify graph. *)
      lwt graph_file = Lwt_io.open_file ~mode:Lwt_io.output !graph_name in
      Lwt_io.write graph_file graph' >>
      Lwt_io.flush graph_file
    end else begin
      (* Render graph. *)
      let r, w = Unix.pipe () in
      let w'   = Lwt_io.of_unix_fd ~mode:Lwt_io.output w in
      Lwt_io.write w' graph' >> Lwt_io.flush w' >>= fun () ->
      Unix.close w;
      lwt png  = Lwt_process.pread ~stdin:(`FD_copy r) (!dot_cmd, [|!dot_cmd; "-Tpng"|]) in
      (* Display graph. *)
      Lwt_process.pwrite (!open_cmd, [|!open_cmd; "-"|]) png
    end)