/***********************************************************************/
/*                                                                     */
/*                           Objective Caml                            */
/*                                                                     */
/*         Xavier Leroy and Damien Doligez, INRIA Rocquencourt         */
/*                                                                     */
/*  Copyright 1996 Institut National de Recherche en Informatique et   */
/*  en Automatique.  All rights reserved.  This file is distributed    */
/*  under the terms of the GNU Library General Public License.         */
/*                                                                     */
/***********************************************************************/

/***---------------------------------------------------------------------
  Modified and adapted for the Lazy Virtual Machine by Daan Leijen.
  Modifications copyright 2001, Daan Leijen. This (modified) file is
  distributed under the terms of the GNU Library General Public License.
---------------------------------------------------------------------***/

/* $Id$ */

/* 1. Allocation functions doing the same work as the macros in the
      case where [Setup_for_gc] and [Restore_after_gc] are no-ops.
   2. Convenience functions related to allocation.
*/

#include <string.h>
#include <alloc.h>
#include "mlvalues.h"
#include "heapfast.h"
#include "custom.h"

#define Setup_for_gc
#define Restore_after_gc

value alloc (mlsize_t wosize, tag_t tag)
{
  value result;
  mlsize_t i;

  Assert (tag < 256);
  if (wosize == 0){
    result = Atom (tag);
  } else if (wosize <= Max_young_wosize){
    Alloc_small (result, wosize, tag);
    if (tag < No_scan_tag){
      for (i = 0; i < wosize; i++) Field (result, i) = 0;
    }
  }else{
    result = alloc_shr (wosize, tag);
    if (tag < No_scan_tag) memset (Bp_val (result), 0, Bsize_wsize (wosize));
    result = check_urgent_gc (result);
  }
  return result;
}

value alloc_major(mlsize_t wosize, tag_t tag)
{
  value result;
  Assert (tag < 256);
  if (wosize == 0){
    result = Atom (tag);
  } else{
    result = alloc_shr (wosize, tag);
    if (tag < No_scan_tag) memset (Bp_val (result), 0, Bsize_wsize (wosize));
    result = check_urgent_gc (result);
  }
  return result;
}

value alloc_small (mlsize_t wosize, tag_t tag)
{
  value result;
  mlsize_t i;
  Assert (wosize > 0);
  Assert (wosize <= Max_young_wosize);
  Assert (tag < 256);
  Alloc_small (result, wosize, tag);
  for(i=0;i<wosize;i++) Field(result,i) = 0;
  return result;
}

value alloc_tuple(mlsize_t n)
{
  return alloc(n, 0);
}

value alloc_string (mlsize_t len)
{
  value result;
  mlsize_t offset_index;
  mlsize_t wosize = (len + sizeof (value)) / sizeof (value);

  if (wosize <= Max_young_wosize) {
    Alloc_small (result, wosize, String_tag);
  }else{
    result = alloc_shr (wosize, String_tag);
    result = check_urgent_gc (result);
  }
  Field (result, wosize - 1) = 0;
  offset_index = Bsize_wsize (wosize) - 1;
  Byte (result, offset_index) = (char)(offset_index - len);
  return result;
}

value alloc_string_major (mlsize_t len)
{
  value result;
  mlsize_t offset_index;
  mlsize_t wosize = (len + sizeof (value)) / sizeof (value);

  result = alloc_shr (wosize, String_tag);
  result = check_urgent_gc(result);

  Field (result, wosize - 1) = 0;
  offset_index = Bsize_wsize (wosize) - 1;
  Byte (result, offset_index) = (char)(offset_index - len);
  return result;
}


value alloc_final (mlsize_t len, final_fun fun, mlsize_t mem, mlsize_t max)
{
  return alloc_custom(final_custom_operations(fun),
                      len * sizeof(value), mem, max);
}

value copy_string(const char *s)
{
  int len;
  value res;

  if (s == NULL) len = 0;
            else len = strlen(s);

  res = alloc_string(len);
  memmove(String_val(res), s, len);
  return res;
}

value alloc_array(value (*funct)(const char *), const char ** arr)
{
  CAMLparam0 ();
  mlsize_t nbr, n;
  CAMLlocal2 (v, result);

  nbr = 0;
  while (arr[nbr] != 0) nbr++;
  if (nbr == 0) {
    CAMLreturn (Atom(0));
  } else {
    result = alloc (nbr, 0);
    for (n = 0; n < nbr; n++) {
      /* The two statements below must be separate because of evaluation
         order (don't take the address &Field(result, n) before
         calling funct, which may cause a GC and move result). */
      v = funct(arr[n]);
      modify(&Field(result, n), v);
    }
    CAMLreturn (result);
  }
}

value copy_string_array(const char **arr)
{
  return alloc_array(copy_string, arr);
}

int convert_flag_list(value list, int *flags)
{
  int res;
  res = 0;
  while (list != Val_int(0)) {
    res |= flags[Int_val(Field(list, 0))];
    list = Field(list, 1);
  }
  return res;
}

/* For compiling let rec over values */

value alloc_dummy(value size) /* ML */
{
  mlsize_t wosize = Int_val(size);

  if (wosize == 0) return Atom(0);
  return alloc (wosize, 0);
}

value update_dummy(value dummy, value newval) /* ML */
{
  wsize_t size, i;
  size = Wosize_val(newval);
  Assert (size == Wosize_val(dummy));
  Tag_val(dummy) = Tag_val(newval);
  for (i = 0; i < size; i++)
    modify(&Field(dummy, i), Field(newval, i));
  return Val_unit;
}