(***********************************************************************)
(*                                                                     *)
(*                                OCaml                                *)
(*                                                                     *)
(*          Jerome Vouillon, projet Cristal, INRIA Rocquencourt        *)
(*          OCaml port by John Malecki and Xavier Leroy                *)
(*                                                                     *)
(*  Copyright 1996 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* Program loading *)

open Unix
open Debugger_config
open Parameters
open Input_handling

(*** Debugging. ***)

let debug_loading = ref false

(*** Load a program. ***)

(* Function used for launching the program. *)
let launching_func = ref (function () -> ())

let load_program () =
  !launching_func ();
  main_loop ()

(*** Launching functions. ***)

(* Returns the environment to be passed to debugee *)
let get_environment () =
  let env = Unix.environment () in
  let have_same_name x y =
    let split = Primitives.split_string '=' in
    match split x, split y with
      (hd1 :: _), (hd2 :: _) -> hd1 = hd2
    | _ -> false in
  let have_name_in_config_env x =
    List.exists
      (have_same_name x)
      !Debugger_config.environment in
  let env =
    Array.fold_right
      (fun elem acc ->
        if have_name_in_config_env elem then
          acc
        else
          elem :: acc)
      env
      [] in
  Array.of_list (env @ !Debugger_config.environment)

(* Returns the environment to be passed to debugee *)
let get_win32_environment () =
  let res = Buffer.create 256 in
  let env = get_environment () in
  let len = Array.length env in
  for i = 0 to pred len do
    Buffer.add_string res (Printf.sprintf "set %s && " env.(i))
  done;
  Buffer.contents res

(* A generic function for launching the program *)
let generic_exec_unix cmdline = function () ->
  if !debug_loading then
    prerr_endline "Launching program...";
  let child =
    try
      fork ()
    with x ->
      Unix_tools.report_error x;
      raise Toplevel in
  match child with
    0 ->
      begin try
         match fork () with
           0 -> (* Try to detach the process from the controlling terminal,
                   so that it does not receive SIGINT on ctrl-C. *)
                begin try ignore(setsid()) with Invalid_argument _ -> () end;
                execve shell [| shell; "-c"; cmdline() |] (get_environment ())
         | _ -> exit 0
       with x ->
         Unix_tools.report_error x;
         exit 1
       end
  | _ ->
     match wait () with
       (_, WEXITED 0) -> ()
     | _ -> raise Toplevel

let generic_exec_win cmdline = function () ->
  if !debug_loading then
    prerr_endline "Launching program...";
  try ignore(create_process "cmd.exe" [| "/C"; cmdline() |] stdin stdout stderr)
  with x ->
    Unix_tools.report_error x;
    raise Toplevel

let generic_exec =
  match Sys.os_type with
    "Win32" -> generic_exec_win
  | _ -> generic_exec_unix

(* Execute the program by calling the runtime explicitly *)
let exec_with_runtime =
  generic_exec
    (function () ->
      match Sys.os_type with
        "Win32" ->
          (* This fould fail on a file name with spaces
             but quoting is even worse because Unix.create_process
             thinks each command line parameter is a file.
             So no good solution so far *)
          Printf.sprintf "%sset CAML_DEBUG_SOCKET=%s && %s %s %s"
                     (get_win32_environment ())
                     !socket_name
                     runtime_program
                     !program_name
                     !arguments
      | _ ->
          Printf.sprintf "CAML_DEBUG_SOCKET=%s %s %s %s"
                     !socket_name
                     (Filename.quote runtime_program)
                     (Filename.quote !program_name)
                     !arguments)

(* Excute the program directly *)
let exec_direct =
  generic_exec
    (function () ->
      match Sys.os_type with
        "Win32" ->
          (* See the comment above *)
          Printf.sprintf "%sset CAML_DEBUG_SOCKET=%s && %s %s"
                     (get_win32_environment ())
                     !socket_name
                     !program_name
                     !arguments
      | _ ->
          Printf.sprintf "CAML_DEBUG_SOCKET=%s %s %s"
                     !socket_name
                     (Filename.quote !program_name)
                     !arguments)

(* Ask the user. *)
let exec_manual =
  function () ->
    print_newline ();
    print_string "Waiting for connection...";
    print_string ("(the socket is " ^ !socket_name ^ ")");
    print_newline ()

(*** Selection of the launching function. ***)

type launching_function = (unit -> unit)

let loading_modes =
  ["direct", exec_direct;
   "runtime", exec_with_runtime;
   "manual", exec_manual]

let set_launching_function func =
  launching_func := func

(* Initialization *)

let _ =
  set_launching_function exec_direct

(*** Connection. ***)

let connection = ref Primitives.std_io
let connection_opened = ref false