/*************************************************************************/

/*                                                                       */

/*                         OCaml LablTk library                          */

/*                                                                       */

/*         Francois Rouaix, Francois Pessaux and Jun Furuse              */

/*               projet Cristal, INRIA Rocquencourt                      */

/*            Jacques Garrigue, Kyoto University RIMS                    */

/*                                                                       */

/*   Copyright 1999 Institut National de Recherche en Informatique et    */

/*   en Automatique and Kyoto University.  All rights reserved.          */

/*   This file is distributed under the terms of the GNU Library         */

/*   General Public License, with the special exception on linking       */

/*   described in file ../../../LICENSE.                                 */

/*                                                                       */

/*************************************************************************/

/* $Id$ */

#include <unistd.h>

#include <fcntl.h>

#include <tcl.h>

#include <tk.h>

#include "gc.h"

#include "exec.h"

#include "sys.h"

#include "fail.h"

#include "io.h"

#include "mlvalues.h"

#include "memory.h"

#include "camltk.h"

#ifndef O_BINARY

#define O_BINARY 0

#endif

/*

 * Dealing with signals: when a signal handler is defined in OCaml,

 * the actual execution of the signal handler upon reception of the

 * signal is delayed until we are sure we are out of the GC.

 * If a signal occurs during the MainLoop, we would have to wait

 *  the next event for the handler to be invoked.

 * The following function will invoke a pending signal handler if any,

 * and we put in on a regular timer.

 */

#define SIGNAL_INTERVAL 300

int signal_events = 0; /* do we have a pending timer */

void invoke_pending_caml_signals (clientdata)

     ClientData clientdata;

{

  signal_events = 0;

  caml_enter_blocking_section(); /* triggers signal handling */

  /* Rearm timer */

  Tk_CreateTimerHandler(SIGNAL_INTERVAL, invoke_pending_caml_signals, NULL);

  signal_events = 1;

  caml_leave_blocking_section();

}

/* The following is taken from byterun/startup.c */

header_t atom_table[256];

code_t start_code;

asize_t code_size;

static void init_atoms()

{

  int i;

  for(i = 0; i < 256; i++) atom_table[i] = Make_header(0, i, White);

}

static unsigned long read_size(p)

     unsigned char * p;

{

  return ((unsigned long) p[0] << 24) + ((unsigned long) p[1] << 16) +

         ((unsigned long) p[2] << 8) + p[3];

}

#define FILE_NOT_FOUND (-1)

#define TRUNCATED_FILE (-2)

#define BAD_MAGIC_NUM (-3)

static int read_trailer(fd, trail)

     int fd;

     struct exec_trailer * trail;

{

  char buffer[TRAILER_SIZE];

  lseek(fd, (long) -TRAILER_SIZE, 2);

  if (read(fd, buffer, TRAILER_SIZE) < TRAILER_SIZE) return TRUNCATED_FILE;

  trail->code_size = read_size(buffer);

  trail->data_size = read_size(buffer+4);

  trail->symbol_size = read_size(buffer+8);

  trail->debug_size = read_size(buffer+12);

  if (strncmp(buffer + 16, EXEC_MAGIC, 12) == 0)

    return 0;

  else

    return BAD_MAGIC_NUM;

}

int attempt_open(name, trail, do_open_script)

     char ** name;

     struct exec_trailer * trail;

     int do_open_script;

{

  char * truename;

  int fd;

  int err;

  char buf [2];

  truename = searchpath(*name);

  if (truename == 0) truename = *name; else *name = truename;

  fd = open(truename, O_RDONLY | O_BINARY);

  if (fd == -1) return FILE_NOT_FOUND;

  if (!do_open_script){

    err = read (fd, buf, 2);

    if (err < 2) { close(fd); return TRUNCATED_FILE; }

    if (buf [0] == '#' && buf [1] == '!') { close(fd); return BAD_MAGIC_NUM; }

  }

  err = read_trailer(fd, trail);

  if (err != 0) { close(fd); return err; }

  return fd;

}

/* Command for loading the bytecode file */

int CamlRunCmd(dummy, interp, argc, argv)

    ClientData dummy;                   /* Not used. */

    Tcl_Interp *interp;                 /* Current interpreter. */

    int argc;                           /* Number of arguments. */

    char **argv;                        /* Argument strings. */

{

  int fd;

  struct exec_trailer trail;

  struct longjmp_buffer raise_buf;

  struct channel * chan;

  if (argc < 2) {

        Tcl_AppendResult(interp, "wrong # args: should be \"",

                argv[0], " foo.cmo args\"", (char *) NULL);

        return TCL_ERROR;

  }

  fd = attempt_open(&argv[1], &trail, 1);

  switch(fd) {

  case FILE_NOT_FOUND:

    fatal_error_arg("Fatal error: cannot find file %s\n", argv[1]);

    break;

  case TRUNCATED_FILE:

  case BAD_MAGIC_NUM:

    fatal_error_arg(

                    "Fatal error: the file %s is not a bytecode executable file\n",

                    argv[1]);

    break;

  }

  if (sigsetjmp(raise_buf.buf, 1) == 0) {

    external_raise = &raise_buf;

    lseek(fd, - (long) (TRAILER_SIZE + trail.code_size + trail.data_size

                        + trail.symbol_size + trail.debug_size), 2);

    code_size = trail.code_size;

    start_code = (code_t) caml_stat_alloc(code_size);

    if (read(fd, (char *) start_code, code_size) != code_size)

      fatal_error("Fatal error: truncated bytecode file.\n");

#ifdef ARCH_BIG_ENDIAN

    fixup_endianness(start_code, code_size);

#endif

    chan = open_descr(fd);

    global_data = input_value(chan);

    close_channel(chan);

    /* Ensure that the globals are in the major heap. */

    oldify(global_data, &global_data);

    sys_init(argv + 1);

    interprete(start_code, code_size);

    return TCL_OK;

  } else {

    Tcl_AppendResult(interp, "Caml program", argv[1], " raised exception \"",

                     String_val(Field(Field(exn_bucket, 0), 0)));

    return TCL_ERROR;

  }

}

int CamlInvokeCmd(dummy

/* Now the real Tk stuff */

Tk_Window cltk_mainWindow;

#define RCNAME ".camltkrc"

#define CAMLCB "camlcb"

/* Initialisation of the dynamically loaded module */

int Caml_Init(interp)

     Tcl_Interp *interp;

{

  cltclinterp = interp;

  /* Create the camlcallback command */

  Tcl_CreateCommand(cltclinterp,

                    CAMLCB, CamlCBCmd,

                    (ClientData)NULL,(Tcl_CmdDeleteProc *)NULL);

  /* This is required by "unknown" and thus autoload */

  Tcl_SetVar(cltclinterp, "tcl_interactive", "0", TCL_GLOBAL_ONLY);

  /* Our hack for implementing break in callbacks */

  Tcl_SetVar(cltclinterp, "BreakBindingsSequence", "0", TCL_GLOBAL_ONLY);

  /* Load the traditional rc file */

  {

    char *home = getenv("HOME");

    if (home != NULL) {

      char *f = caml_stat_alloc(strlen(home)+strlen(RCNAME)+2);

      f[0]='\0';

      strcat(f, home);

      strcat(f, "/");

      strcat(f, RCNAME);

      if (0 == access(f,R_OK))

        if (TCL_OK != Tcl_EvalFile(cltclinterp,f)) {

          caml_stat_free(f);

          tk_error(Tcl_GetStringResult(cltclinterp));

        };

      caml_stat_free(f);

    }

  }

  /* Initialisations from caml_main */

  {

    int verbose_init = 0,

        percent_free_init = Percent_free_def;

    long minor_heap_init = Minor_heap_def,

         heap_chunk_init = Heap_chunk_def;

    /* Machine-dependent initialization of the floating-point hardware

       so that it behaves as much as possible as specified in IEEE */

    init_ieee_floats();

    init_gc (minor_heap_init, heap_chunk_init, percent_free_init,

             verbose_init);

    init_stack();

    init_atoms();

  }

}