src/vm.c

/* Copyright (C) 2001 Free Software Foundation, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA
 *
 * As a special exception, the Free Software Foundation gives permission
 * for additional uses of the text contained in its release of GUILE.
 *
 * The exception is that, if you link the GUILE library with other files
 * to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the GUILE library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the
 * Free Software Foundation under the name GUILE.  If you copy
 * code from other Free Software Foundation releases into a copy of
 * GUILE, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for GUILE, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.  */

#include <string.h>
#include "envs.h"
#include "frames.h"
#include "instructions.h"
#include "objcodes.h"
#include "programs.h"
#include "vm.h"

/* I sometimes use this for debugging. */
#define vm_puts(OBJ)				\
{						\
  scm_display (OBJ, scm_def_errp);		\
  scm_newline (scm_def_errp);			\
}

\f
/*
 * VM Continuation
 */

scm_bits_t scm_tc16_vm_cont;


#define SCM_VM_CONT_P(OBJ)	SCM_SMOB_PREDICATE (scm_tc16_vm_cont, OBJ)
#define SCM_VM_CONT_VP(CONT)	((struct scm_vm *) SCM_CELL_WORD_1 (CONT))

static SCM
capture_vm_cont (struct scm_vm *vp)
{
  struct scm_vm *p = scm_must_malloc (sizeof (*p), "capture_vm_cont");
  p->stack_size = vp->stack_limit - vp->sp;
  p->stack_base = scm_must_malloc (p->stack_size * sizeof (SCM),
				   "capture_vm_cont");
  p->stack_limit = p->stack_base + p->stack_size - 2;
  p->ip = vp->ip;
  p->sp = (SCM *) (vp->stack_limit - vp->sp);
  p->fp = (SCM *) (vp->stack_limit - vp->fp);
  memcpy (p->stack_base, vp->sp + 1, vp->stack_size * sizeof (SCM));
  SCM_RETURN_NEWSMOB (scm_tc16_vm_cont, p);
}

static void
reinstate_vm_cont (struct scm_vm *vp, SCM cont)
{
  struct scm_vm *p = SCM_VM_CONT_VP (cont);
  if (vp->stack_size < p->stack_size)
    {
      /* puts ("FIXME: Need to expand"); */
      abort ();
    }
  vp->ip = p->ip;
  vp->sp = vp->stack_limit - (int) p->sp;
  vp->fp = vp->stack_limit - (int) p->fp;
  memcpy (vp->sp + 1, p->stack_base, p->stack_size * sizeof (SCM));
}

static SCM
vm_cont_mark (SCM obj)
{
  SCM *p;
  struct scm_vm *vp = SCM_VM_CONT_VP (obj);
  for (p = vp->stack_base; p <= vp->stack_limit; p++)
    if (SCM_NIMP (*p))
      scm_gc_mark (*p);
  return SCM_BOOL_F;
}

static scm_sizet
vm_cont_free (SCM obj)
{
  struct scm_vm *p = SCM_VM_CONT_VP (obj);
  int size = sizeof (struct scm_vm) + p->stack_size * sizeof (SCM);
  scm_must_free (p->stack_base);
  scm_must_free (p);
  return size;
}

\f
/*
 * VM Internal functions
 */

SCM_SYMBOL (sym_vm_run, "vm-run");
SCM_SYMBOL (sym_vm_error, "vm-error");

static scm_byte_t *
vm_fetch_length (scm_byte_t *ip, size_t *lenp)
{
  /* NOTE: format defined in system/vm/conv.scm */
  *lenp = *ip++;
  if (*lenp < 254)
    return ip;
  else if (*lenp == 254)
    {
      int b1 = *ip++;
      int b2 = *ip++;
      *lenp = (b1 << 8) + b2;
    }
  else
    {
      int b1 = *ip++;
      int b2 = *ip++;
      int b3 = *ip++;
      int b4 = *ip++;
      *lenp = (b1 << 24) + (b2 << 16) + (b3 << 8) + b4;
    }
  return ip;
}

static SCM
vm_heapify_frames_1 (struct scm_vm *vp, SCM *fp, SCM *sp, SCM **destp)
{
  SCM frame;
  SCM *dl = SCM_FRAME_DYNAMIC_LINK (fp);
  SCM *src = SCM_FRAME_UPPER_ADDRESS (fp);
  SCM *dest = SCM_FRAME_LOWER_ADDRESS (fp);

  if (!dl)
    {
      /* The top frame */
      frame = scm_c_make_heap_frame (fp);
      fp = SCM_HEAP_FRAME_POINTER (frame);
      SCM_FRAME_HEAP_LINK (fp) = SCM_BOOL_T;
    }
  else
    {
      /* Child frames */
      SCM link = SCM_FRAME_HEAP_LINK (dl);
      if (!SCM_FALSEP (link))
	link = SCM_FRAME_LOWER_ADDRESS (dl)[-1]; /* self link */
      else
	link = vm_heapify_frames_1 (vp, dl, dest - 1, &dest);
      frame = scm_c_make_heap_frame (fp);
      fp = SCM_HEAP_FRAME_POINTER (frame);
      SCM_FRAME_HEAP_LINK (fp)    = link;
      SCM_FRAME_DYNAMIC_LINK (fp) = SCM_HEAP_FRAME_POINTER (link);
    }

  /* Move stack data */
  for (; src <= sp; src++, dest++)
    *dest = *src;
  *destp = dest;

  return frame;
}

static SCM
vm_heapify_frames (SCM vm)
{
  struct scm_vm *vp = SCM_VM_DATA (vm);
  if (SCM_FALSEP (SCM_FRAME_HEAP_LINK (vp->fp)))
    {
      SCM *dest;
      vp->this_frame = vm_heapify_frames_1 (vp, vp->fp, vp->sp, &dest);
      vp->fp = SCM_HEAP_FRAME_POINTER (vp->this_frame);
      vp->sp = dest - 1;
    }
  return vp->this_frame;
}

\f
/*
 * VM
 */

#define VM_DEFAULT_STACK_SIZE	(16 * 1024)

#define VM_REGULAR_ENGINE	0
#define VM_DEBUG_ENGINE		1

#if 0
#define VM_NAME   vm_regular_engine
#define VM_ENGINE VM_REGULAR_ENGINE
#include "vm_engine.c"
#undef VM_NAME
#undef VM_ENGINE
#endif

#define VM_NAME	  vm_debug_engine
#define VM_ENGINE VM_DEBUG_ENGINE
#include "vm_engine.c"
#undef VM_NAME
#undef VM_ENGINE

scm_bits_t scm_tc16_vm;

static SCM the_vm;

static SCM
make_vm (void)
#define FUNC_NAME "make_vm"
{
  int i;
  struct scm_vm *vp = SCM_MUST_MALLOC (sizeof (struct scm_vm));
  vp->stack_size  = VM_DEFAULT_STACK_SIZE;
  vp->stack_base  = SCM_MUST_MALLOC (vp->stack_size * sizeof (SCM));
  vp->stack_limit = vp->stack_base + vp->stack_size - 3;
  vp->ip    	  = NULL;
  vp->sp    	  = vp->stack_base - 1;
  vp->fp    	  = NULL;
  vp->time        = 0;
  vp->clock       = 0;
  vp->options     = SCM_EOL;
  vp->this_frame  = SCM_BOOL_F;
  vp->last_frame  = SCM_BOOL_F;
  for (i = 0; i < SCM_VM_NUM_HOOKS; i++)
    vp->hooks[i] = SCM_BOOL_F;
  SCM_RETURN_NEWSMOB (scm_tc16_vm, vp);
}
#undef FUNC_NAME

static SCM
vm_mark (SCM obj)
{
  int i;
  struct scm_vm *vp = SCM_VM_DATA (obj);

  /* mark the stack conservatively */
  scm_mark_locations ((SCM_STACKITEM *) vp->stack_base,
		      sizeof (SCM) * (vp->sp - vp->stack_base + 1));

  /* mark other objects  */
  for (i = 0; i < SCM_VM_NUM_HOOKS; i++)
    scm_gc_mark (vp->hooks[i]);
  scm_gc_mark (vp->this_frame);
  scm_gc_mark (vp->last_frame);
  return vp->options;
}

static scm_sizet
vm_free (SCM obj)
{
  struct scm_vm *vp = SCM_VM_DATA (obj);
  int size = (sizeof (struct scm_vm) + vp->stack_size * sizeof (SCM));
  scm_must_free (vp->stack_base);
  scm_must_free (vp);
  return size;
}

SCM_SYMBOL (sym_debug, "debug");

SCM
scm_vm_apply (SCM vm, SCM program, SCM args)
#define FUNC_NAME "scm_vm_apply"
{
  SCM_VALIDATE_PROGRAM (1, program);
  return vm_run (vm, program, args);
}
#undef FUNC_NAME

/* Scheme interface */

SCM_DEFINE (scm_vm_version, "vm-version", 0, 0, 0,
	    (void),
	    "")
#define FUNC_NAME s_scm_vm_version
{
  return scm_makfrom0str (VERSION);
}
#undef FUNC_NAME

SCM_DEFINE (scm_the_vm, "the-vm", 0, 0, 0,
	    (),
	    "")
#define FUNC_NAME s_scm_the_vm
{
  return the_vm;
}
#undef FUNC_NAME


SCM_DEFINE (scm_vm_p, "vm?", 1, 0, 0,
	    (SCM obj),
	    "")
#define FUNC_NAME s_scm_vm_p
{
  return SCM_BOOL (SCM_VM_P (obj));
}
#undef FUNC_NAME

SCM_DEFINE (scm_make_vm, "make-vm", 0, 0, 0,
	    (void),
	    "")
#define FUNC_NAME s_scm_make_vm,
{
  return make_vm ();
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_ip, "vm:ip", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_ip
{
  SCM_VALIDATE_VM (1, vm);
  return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->ip);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_sp, "vm:sp", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_sp
{
  SCM_VALIDATE_VM (1, vm);
  return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->sp);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_fp, "vm:fp", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_fp
{
  SCM_VALIDATE_VM (1, vm);
  return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->fp);
}
#undef FUNC_NAME

#define VM_DEFINE_HOOK(n)				\
{							\
  struct scm_vm *vp;					\
  SCM_VALIDATE_VM (1, vm);				\
  vp = SCM_VM_DATA (vm);				\
  if (SCM_FALSEP (vp->hooks[n]))			\
    vp->hooks[n] = scm_make_hook (SCM_MAKINUM (1));	\
  return vp->hooks[n];					\
}

SCM_DEFINE (scm_vm_boot_hook, "vm-boot-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_boot_hook
{
  VM_DEFINE_HOOK (SCM_VM_BOOT_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_halt_hook, "vm-halt-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_halt_hook
{
  VM_DEFINE_HOOK (SCM_VM_HALT_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_next_hook, "vm-next-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_next_hook
{
  VM_DEFINE_HOOK (SCM_VM_NEXT_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_enter_hook, "vm-enter-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_enter_hook
{
  VM_DEFINE_HOOK (SCM_VM_ENTER_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_apply_hook, "vm-apply-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_apply_hook
{
  VM_DEFINE_HOOK (SCM_VM_APPLY_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_exit_hook, "vm-exit-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_exit_hook
{
  VM_DEFINE_HOOK (SCM_VM_EXIT_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_return_hook, "vm-return-hook", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_return_hook
{
  VM_DEFINE_HOOK (SCM_VM_RETURN_HOOK);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_option, "vm-option", 2, 0, 0,
	    (SCM vm, SCM key),
	    "")
#define FUNC_NAME s_scm_vm_option
{
  SCM_VALIDATE_VM (1, vm);
  return scm_assq_ref (SCM_VM_DATA (vm)->options, key);
}
#undef FUNC_NAME

SCM_DEFINE (scm_set_vm_option_x, "set-vm-option!", 3, 0, 0,
	    (SCM vm, SCM key, SCM val),
	    "")
#define FUNC_NAME s_scm_set_vm_option_x
{
  SCM_VALIDATE_VM (1, vm);
  SCM_VM_DATA (vm)->options
    = scm_assq_set_x (SCM_VM_DATA (vm)->options, key, val);
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_stats, "vm-stats", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_stats
{
  SCM stats;

  SCM_VALIDATE_VM (1, vm);

  stats = scm_c_make_vector (2, SCM_MAKINUM (0));
  SCM_VELTS (stats)[0] = scm_ulong2num (SCM_VM_DATA (vm)->time);
  SCM_VELTS (stats)[1] = scm_ulong2num (SCM_VM_DATA (vm)->clock);

  return stats;
}
#undef FUNC_NAME

#define VM_CHECK_RUNNING(vm) 				\
  if (!SCM_VM_DATA (vm)->ip)				\
    SCM_MISC_ERROR ("Not running", SCM_LIST1 (vm))

SCM_DEFINE (scm_vm_this_frame, "vm-this-frame", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_this_frame
{
  SCM_VALIDATE_VM (1, vm);
  return SCM_VM_DATA (vm)->this_frame;
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_last_frame, "vm-last-frame", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_last_frame
{
  SCM_VALIDATE_VM (1, vm);
  return SCM_VM_DATA (vm)->last_frame;
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_fetch_code, "vm-fetch-code", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_fetch_code
{
  int i;
  SCM list;
  scm_byte_t *ip;
  struct scm_instruction *p;

  SCM_VALIDATE_VM (1, vm);
  VM_CHECK_RUNNING (vm);

  ip = SCM_VM_DATA (vm)->ip;
  p = SCM_INSTRUCTION (*ip);

  list = SCM_LIST1 (scm_str2symbol (p->name));
  for (i = 1; i <= p->len; i++)
    list = scm_cons (SCM_MAKINUM (ip[i]), list);
  return scm_reverse_x (list, SCM_EOL);
}
#undef FUNC_NAME

SCM_DEFINE (scm_vm_fetch_stack, "vm-fetch-stack", 1, 0, 0,
	    (SCM vm),
	    "")
#define FUNC_NAME s_scm_vm_fetch_stack
{
  SCM *sp;
  SCM ls = SCM_EOL;
  struct scm_vm *vp;

  SCM_VALIDATE_VM (1, vm);
  VM_CHECK_RUNNING (vm);

  vp = SCM_VM_DATA (vm);
  for (sp = vp->stack_base; sp <= vp->sp; sp++)
    ls = scm_cons (*sp, ls);
  return ls;
}
#undef FUNC_NAME

\f
/*
 * Initialize
 */

void
scm_init_vm (void)
{
  scm_init_frames ();
  scm_init_instructions ();
  scm_init_objcodes ();
  scm_init_programs ();

  scm_tc16_vm_cont = scm_make_smob_type ("vm-cont", 0);
  scm_set_smob_mark (scm_tc16_vm_cont, vm_cont_mark);
  scm_set_smob_free (scm_tc16_vm_cont, vm_cont_free);

  scm_tc16_vm = scm_make_smob_type ("vm", 0);
  scm_set_smob_mark (scm_tc16_vm, vm_mark);
  scm_set_smob_free (scm_tc16_vm, vm_free);
  scm_set_smob_apply (scm_tc16_vm, scm_vm_apply, 1, 0, 1);

  the_vm = scm_permanent_object (make_vm ());

#ifndef SCM_MAGIC_SNARFER
#include "vm.x"
#endif
}

/*
  Local Variables:
  c-file-style: "gnu"
  End:
*/
Commit	Line	Data
	1	/* Copyright (C) 2001 Free Software Foundation, Inc.
	2	*
	3	* This program is free software; you can redistribute it and/or modify
	4	* it under the terms of the GNU General Public License as published by
	5	* the Free Software Foundation; either version 2, or (at your option)
	6	* any later version.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License
	14	* along with this software; see the file COPYING. If not, write to
	15	* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
	16	* Boston, MA 02111-1307 USA
	17	*
	18	* As a special exception, the Free Software Foundation gives permission
	19	* for additional uses of the text contained in its release of GUILE.
	20	*
	21	* The exception is that, if you link the GUILE library with other files
	22	* to produce an executable, this does not by itself cause the
	23	* resulting executable to be covered by the GNU General Public License.
	24	* Your use of that executable is in no way restricted on account of
	25	* linking the GUILE library code into it.
	26	*
	27	* This exception does not however invalidate any other reasons why
	28	* the executable file might be covered by the GNU General Public License.
	29	*
	30	* This exception applies only to the code released by the
	31	* Free Software Foundation under the name GUILE. If you copy
	32	* code from other Free Software Foundation releases into a copy of
	33	* GUILE, as the General Public License permits, the exception does
	34	* not apply to the code that you add in this way. To avoid misleading
	35	* anyone as to the status of such modified files, you must delete
	36	* this exception notice from them.
	37	*
	38	* If you write modifications of your own for GUILE, it is your choice
	39	* whether to permit this exception to apply to your modifications.
	40	* If you do not wish that, delete this exception notice. */
	41
	42	#include <string.h>
	43	#include "envs.h"
	44	#include "frames.h"
	45	#include "instructions.h"
	46	#include "objcodes.h"
	47	#include "programs.h"
	48	#include "vm.h"
	49
	50	/* I sometimes use this for debugging. */
	51	#define vm_puts(OBJ) \
	52	{ \
	53	scm_display (OBJ, scm_def_errp); \
	54	scm_newline (scm_def_errp); \
	55	}
	56
	57	\f
	58	/*
	59	* VM Continuation
	60	*/
	61
	62	scm_bits_t scm_tc16_vm_cont;
	63
	64
	65	#define SCM_VM_CONT_P(OBJ) SCM_SMOB_PREDICATE (scm_tc16_vm_cont, OBJ)
	66	#define SCM_VM_CONT_VP(CONT) ((struct scm_vm *) SCM_CELL_WORD_1 (CONT))
	67
	68	static SCM
	69	capture_vm_cont (struct scm_vm *vp)
	70	{
	71	struct scm_vm p = scm_must_malloc (sizeof (p), "capture_vm_cont");
	72	p->stack_size = vp->stack_limit - vp->sp;
	73	p->stack_base = scm_must_malloc (p->stack_size * sizeof (SCM),
	74	"capture_vm_cont");
	75	p->stack_limit = p->stack_base + p->stack_size - 2;
	76	p->ip = vp->ip;
	77	p->sp = (SCM *) (vp->stack_limit - vp->sp);
	78	p->fp = (SCM *) (vp->stack_limit - vp->fp);
	79	memcpy (p->stack_base, vp->sp + 1, vp->stack_size * sizeof (SCM));
	80	SCM_RETURN_NEWSMOB (scm_tc16_vm_cont, p);
	81	}
	82
	83	static void
	84	reinstate_vm_cont (struct scm_vm *vp, SCM cont)
	85	{
	86	struct scm_vm *p = SCM_VM_CONT_VP (cont);
	87	if (vp->stack_size < p->stack_size)
	88	{
	89	/* puts ("FIXME: Need to expand"); */
	90	abort ();
	91	}
	92	vp->ip = p->ip;
	93	vp->sp = vp->stack_limit - (int) p->sp;
	94	vp->fp = vp->stack_limit - (int) p->fp;
	95	memcpy (vp->sp + 1, p->stack_base, p->stack_size * sizeof (SCM));
	96	}
	97
	98	static SCM
	99	vm_cont_mark (SCM obj)
	100	{
	101	SCM *p;
	102	struct scm_vm *vp = SCM_VM_CONT_VP (obj);
	103	for (p = vp->stack_base; p <= vp->stack_limit; p++)
	104	if (SCM_NIMP (*p))
	105	scm_gc_mark (*p);
	106	return SCM_BOOL_F;
	107	}
	108
	109	static scm_sizet
	110	vm_cont_free (SCM obj)
	111	{
	112	struct scm_vm *p = SCM_VM_CONT_VP (obj);
	113	int size = sizeof (struct scm_vm) + p->stack_size * sizeof (SCM);
	114	scm_must_free (p->stack_base);
	115	scm_must_free (p);
	116	return size;
	117	}
	118
	119	\f
	120	/*
	121	* VM Internal functions
	122	*/
	123
	124	SCM_SYMBOL (sym_vm_run, "vm-run");
	125	SCM_SYMBOL (sym_vm_error, "vm-error");
	126
	127	static scm_byte_t *
	128	vm_fetch_length (scm_byte_t ip, size_t lenp)
	129	{
	130	/* NOTE: format defined in system/vm/conv.scm */
	131	lenp = ip++;
	132	if (*lenp < 254)
	133	return ip;
	134	else if (*lenp == 254)
	135	{
	136	int b1 = *ip++;
	137	int b2 = *ip++;
	138	*lenp = (b1 << 8) + b2;
	139	}
	140	else
	141	{
	142	int b1 = *ip++;
	143	int b2 = *ip++;
	144	int b3 = *ip++;
	145	int b4 = *ip++;
	146	*lenp = (b1 << 24) + (b2 << 16) + (b3 << 8) + b4;
	147	}
	148	return ip;
	149	}
	150
	151	static SCM
	152	vm_heapify_frames_1 (struct scm_vm vp, SCM fp, SCM sp, SCM *destp)
	153	{
	154	SCM frame;
	155	SCM *dl = SCM_FRAME_DYNAMIC_LINK (fp);
	156	SCM *src = SCM_FRAME_UPPER_ADDRESS (fp);
	157	SCM *dest = SCM_FRAME_LOWER_ADDRESS (fp);
	158
	159	if (!dl)
	160	{
	161	/* The top frame */
	162	frame = scm_c_make_heap_frame (fp);
	163	fp = SCM_HEAP_FRAME_POINTER (frame);
	164	SCM_FRAME_HEAP_LINK (fp) = SCM_BOOL_T;
	165	}
	166	else
	167	{
	168	/* Child frames */
	169	SCM link = SCM_FRAME_HEAP_LINK (dl);
	170	if (!SCM_FALSEP (link))
	171	link = SCM_FRAME_LOWER_ADDRESS (dl)[-1]; /* self link */
	172	else
	173	link = vm_heapify_frames_1 (vp, dl, dest - 1, &dest);
	174	frame = scm_c_make_heap_frame (fp);
	175	fp = SCM_HEAP_FRAME_POINTER (frame);
	176	SCM_FRAME_HEAP_LINK (fp) = link;
	177	SCM_FRAME_DYNAMIC_LINK (fp) = SCM_HEAP_FRAME_POINTER (link);
	178	}
	179
	180	/* Move stack data */
	181	for (; src <= sp; src++, dest++)
	182	dest = src;
	183	*destp = dest;
	184
	185	return frame;
	186	}
	187
	188	static SCM
	189	vm_heapify_frames (SCM vm)
	190	{
	191	struct scm_vm *vp = SCM_VM_DATA (vm);
	192	if (SCM_FALSEP (SCM_FRAME_HEAP_LINK (vp->fp)))
	193	{
	194	SCM *dest;
	195	vp->this_frame = vm_heapify_frames_1 (vp, vp->fp, vp->sp, &dest);
	196	vp->fp = SCM_HEAP_FRAME_POINTER (vp->this_frame);
	197	vp->sp = dest - 1;
	198	}
	199	return vp->this_frame;
	200	}
	201
	202	\f
	203	/*
	204	* VM
	205	*/
	206
	207	#define VM_DEFAULT_STACK_SIZE (16 * 1024)
	208
	209	#define VM_REGULAR_ENGINE 0
	210	#define VM_DEBUG_ENGINE 1
	211
	212	#if 0
	213	#define VM_NAME vm_regular_engine
	214	#define VM_ENGINE VM_REGULAR_ENGINE
	215	#include "vm_engine.c"
	216	#undef VM_NAME
	217	#undef VM_ENGINE
	218	#endif
	219
	220	#define VM_NAME vm_debug_engine
	221	#define VM_ENGINE VM_DEBUG_ENGINE
	222	#include "vm_engine.c"
	223	#undef VM_NAME
	224	#undef VM_ENGINE
	225
	226	scm_bits_t scm_tc16_vm;
	227
	228	static SCM the_vm;
	229
	230	static SCM
	231	make_vm (void)
	232	#define FUNC_NAME "make_vm"
	233	{
	234	int i;
	235	struct scm_vm *vp = SCM_MUST_MALLOC (sizeof (struct scm_vm));
	236	vp->stack_size = VM_DEFAULT_STACK_SIZE;
	237	vp->stack_base = SCM_MUST_MALLOC (vp->stack_size * sizeof (SCM));
	238	vp->stack_limit = vp->stack_base + vp->stack_size - 3;
	239	vp->ip = NULL;
	240	vp->sp = vp->stack_base - 1;
	241	vp->fp = NULL;
	242	vp->time = 0;
	243	vp->clock = 0;
	244	vp->options = SCM_EOL;
	245	vp->this_frame = SCM_BOOL_F;
	246	vp->last_frame = SCM_BOOL_F;
	247	for (i = 0; i < SCM_VM_NUM_HOOKS; i++)
	248	vp->hooks[i] = SCM_BOOL_F;
	249	SCM_RETURN_NEWSMOB (scm_tc16_vm, vp);
	250	}
	251	#undef FUNC_NAME
	252
	253	static SCM
	254	vm_mark (SCM obj)
	255	{
	256	int i;
	257	struct scm_vm *vp = SCM_VM_DATA (obj);
	258
	259	/* mark the stack conservatively */
	260	scm_mark_locations ((SCM_STACKITEM *) vp->stack_base,
	261	sizeof (SCM) * (vp->sp - vp->stack_base + 1));
	262
	263	/* mark other objects */
	264	for (i = 0; i < SCM_VM_NUM_HOOKS; i++)
	265	scm_gc_mark (vp->hooks[i]);
	266	scm_gc_mark (vp->this_frame);
	267	scm_gc_mark (vp->last_frame);
	268	return vp->options;
	269	}
	270
	271	static scm_sizet
	272	vm_free (SCM obj)
	273	{
	274	struct scm_vm *vp = SCM_VM_DATA (obj);
	275	int size = (sizeof (struct scm_vm) + vp->stack_size * sizeof (SCM));
	276	scm_must_free (vp->stack_base);
	277	scm_must_free (vp);
	278	return size;
	279	}
	280
	281	SCM_SYMBOL (sym_debug, "debug");
	282
	283	SCM
	284	scm_vm_apply (SCM vm, SCM program, SCM args)
	285	#define FUNC_NAME "scm_vm_apply"
	286	{
	287	SCM_VALIDATE_PROGRAM (1, program);
	288	return vm_run (vm, program, args);
	289	}
	290	#undef FUNC_NAME
	291
	292	/* Scheme interface */
	293
	294	SCM_DEFINE (scm_vm_version, "vm-version", 0, 0, 0,
	295	(void),
	296	"")
	297	#define FUNC_NAME s_scm_vm_version
	298	{
	299	return scm_makfrom0str (VERSION);
	300	}
	301	#undef FUNC_NAME
	302
	303	SCM_DEFINE (scm_the_vm, "the-vm", 0, 0, 0,
	304	(),
	305	"")
	306	#define FUNC_NAME s_scm_the_vm
	307	{
	308	return the_vm;
	309	}
	310	#undef FUNC_NAME
	311
	312
	313	SCM_DEFINE (scm_vm_p, "vm?", 1, 0, 0,
	314	(SCM obj),
	315	"")
	316	#define FUNC_NAME s_scm_vm_p
	317	{
	318	return SCM_BOOL (SCM_VM_P (obj));
	319	}
	320	#undef FUNC_NAME
	321
	322	SCM_DEFINE (scm_make_vm, "make-vm", 0, 0, 0,
	323	(void),
	324	"")
	325	#define FUNC_NAME s_scm_make_vm,
	326	{
	327	return make_vm ();
	328	}
	329	#undef FUNC_NAME
	330
	331	SCM_DEFINE (scm_vm_ip, "vm:ip", 1, 0, 0,
	332	(SCM vm),
	333	"")
	334	#define FUNC_NAME s_scm_vm_ip
	335	{
	336	SCM_VALIDATE_VM (1, vm);
	337	return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->ip);
	338	}
	339	#undef FUNC_NAME
	340
	341	SCM_DEFINE (scm_vm_sp, "vm:sp", 1, 0, 0,
	342	(SCM vm),
	343	"")
	344	#define FUNC_NAME s_scm_vm_sp
	345	{
	346	SCM_VALIDATE_VM (1, vm);
	347	return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->sp);
	348	}
	349	#undef FUNC_NAME
	350
	351	SCM_DEFINE (scm_vm_fp, "vm:fp", 1, 0, 0,
	352	(SCM vm),
	353	"")
	354	#define FUNC_NAME s_scm_vm_fp
	355	{
	356	SCM_VALIDATE_VM (1, vm);
	357	return scm_ulong2num ((unsigned long) SCM_VM_DATA (vm)->fp);
	358	}
	359	#undef FUNC_NAME
	360
	361	#define VM_DEFINE_HOOK(n) \
	362	{ \
	363	struct scm_vm *vp; \
	364	SCM_VALIDATE_VM (1, vm); \
	365	vp = SCM_VM_DATA (vm); \
	366	if (SCM_FALSEP (vp->hooks[n])) \
	367	vp->hooks[n] = scm_make_hook (SCM_MAKINUM (1)); \
	368	return vp->hooks[n]; \
	369	}
	370
	371	SCM_DEFINE (scm_vm_boot_hook, "vm-boot-hook", 1, 0, 0,
	372	(SCM vm),
	373	"")
	374	#define FUNC_NAME s_scm_vm_boot_hook
	375	{
	376	VM_DEFINE_HOOK (SCM_VM_BOOT_HOOK);
	377	}
	378	#undef FUNC_NAME
	379
	380	SCM_DEFINE (scm_vm_halt_hook, "vm-halt-hook", 1, 0, 0,
	381	(SCM vm),
	382	"")
	383	#define FUNC_NAME s_scm_vm_halt_hook
	384	{
	385	VM_DEFINE_HOOK (SCM_VM_HALT_HOOK);
	386	}
	387	#undef FUNC_NAME
	388
	389	SCM_DEFINE (scm_vm_next_hook, "vm-next-hook", 1, 0, 0,
	390	(SCM vm),
	391	"")
	392	#define FUNC_NAME s_scm_vm_next_hook
	393	{
	394	VM_DEFINE_HOOK (SCM_VM_NEXT_HOOK);
	395	}
	396	#undef FUNC_NAME
	397
	398	SCM_DEFINE (scm_vm_enter_hook, "vm-enter-hook", 1, 0, 0,
	399	(SCM vm),
	400	"")
	401	#define FUNC_NAME s_scm_vm_enter_hook
	402	{
	403	VM_DEFINE_HOOK (SCM_VM_ENTER_HOOK);
	404	}
	405	#undef FUNC_NAME
	406
	407	SCM_DEFINE (scm_vm_apply_hook, "vm-apply-hook", 1, 0, 0,
	408	(SCM vm),
	409	"")
	410	#define FUNC_NAME s_scm_vm_apply_hook
	411	{
	412	VM_DEFINE_HOOK (SCM_VM_APPLY_HOOK);
	413	}
	414	#undef FUNC_NAME
	415
	416	SCM_DEFINE (scm_vm_exit_hook, "vm-exit-hook", 1, 0, 0,
	417	(SCM vm),
	418	"")
	419	#define FUNC_NAME s_scm_vm_exit_hook
	420	{
	421	VM_DEFINE_HOOK (SCM_VM_EXIT_HOOK);
	422	}
	423	#undef FUNC_NAME
	424
	425	SCM_DEFINE (scm_vm_return_hook, "vm-return-hook", 1, 0, 0,
	426	(SCM vm),
	427	"")
	428	#define FUNC_NAME s_scm_vm_return_hook
	429	{
	430	VM_DEFINE_HOOK (SCM_VM_RETURN_HOOK);
	431	}
	432	#undef FUNC_NAME
	433
	434	SCM_DEFINE (scm_vm_option, "vm-option", 2, 0, 0,
	435	(SCM vm, SCM key),
	436	"")
	437	#define FUNC_NAME s_scm_vm_option
	438	{
	439	SCM_VALIDATE_VM (1, vm);
	440	return scm_assq_ref (SCM_VM_DATA (vm)->options, key);
	441	}
	442	#undef FUNC_NAME
	443
	444	SCM_DEFINE (scm_set_vm_option_x, "set-vm-option!", 3, 0, 0,
	445	(SCM vm, SCM key, SCM val),
	446	"")
	447	#define FUNC_NAME s_scm_set_vm_option_x
	448	{
	449	SCM_VALIDATE_VM (1, vm);
	450	SCM_VM_DATA (vm)->options
	451	= scm_assq_set_x (SCM_VM_DATA (vm)->options, key, val);
	452	return SCM_UNSPECIFIED;
	453	}
	454	#undef FUNC_NAME
	455
	456	SCM_DEFINE (scm_vm_stats, "vm-stats", 1, 0, 0,
	457	(SCM vm),
	458	"")
	459	#define FUNC_NAME s_scm_vm_stats
	460	{
	461	SCM stats;
	462
	463	SCM_VALIDATE_VM (1, vm);
	464
	465	stats = scm_c_make_vector (2, SCM_MAKINUM (0));
	466	SCM_VELTS (stats)[0] = scm_ulong2num (SCM_VM_DATA (vm)->time);
	467	SCM_VELTS (stats)[1] = scm_ulong2num (SCM_VM_DATA (vm)->clock);
	468
	469	return stats;
	470	}
	471	#undef FUNC_NAME
	472
	473	#define VM_CHECK_RUNNING(vm) \
	474	if (!SCM_VM_DATA (vm)->ip) \
	475	SCM_MISC_ERROR ("Not running", SCM_LIST1 (vm))
	476
	477	SCM_DEFINE (scm_vm_this_frame, "vm-this-frame", 1, 0, 0,
	478	(SCM vm),
	479	"")
	480	#define FUNC_NAME s_scm_vm_this_frame
	481	{
	482	SCM_VALIDATE_VM (1, vm);
	483	return SCM_VM_DATA (vm)->this_frame;
	484	}
	485	#undef FUNC_NAME
	486
	487	SCM_DEFINE (scm_vm_last_frame, "vm-last-frame", 1, 0, 0,
	488	(SCM vm),
	489	"")
	490	#define FUNC_NAME s_scm_vm_last_frame
	491	{
	492	SCM_VALIDATE_VM (1, vm);
	493	return SCM_VM_DATA (vm)->last_frame;
	494	}
	495	#undef FUNC_NAME
	496
	497	SCM_DEFINE (scm_vm_fetch_code, "vm-fetch-code", 1, 0, 0,
	498	(SCM vm),
	499	"")
	500	#define FUNC_NAME s_scm_vm_fetch_code
	501	{
	502	int i;
	503	SCM list;
	504	scm_byte_t *ip;
	505	struct scm_instruction *p;
	506
	507	SCM_VALIDATE_VM (1, vm);
	508	VM_CHECK_RUNNING (vm);
	509
	510	ip = SCM_VM_DATA (vm)->ip;
	511	p = SCM_INSTRUCTION (*ip);
	512
	513	list = SCM_LIST1 (scm_str2symbol (p->name));
	514	for (i = 1; i <= p->len; i++)
	515	list = scm_cons (SCM_MAKINUM (ip[i]), list);
	516	return scm_reverse_x (list, SCM_EOL);
	517	}
	518	#undef FUNC_NAME
	519
	520	SCM_DEFINE (scm_vm_fetch_stack, "vm-fetch-stack", 1, 0, 0,
	521	(SCM vm),
	522	"")
	523	#define FUNC_NAME s_scm_vm_fetch_stack
	524	{
	525	SCM *sp;
	526	SCM ls = SCM_EOL;
	527	struct scm_vm *vp;
	528
	529	SCM_VALIDATE_VM (1, vm);
	530	VM_CHECK_RUNNING (vm);
	531
	532	vp = SCM_VM_DATA (vm);
	533	for (sp = vp->stack_base; sp <= vp->sp; sp++)
	534	ls = scm_cons (*sp, ls);
	535	return ls;
	536	}
	537	#undef FUNC_NAME
	538
	539	\f
	540	/*
	541	* Initialize
	542	*/
	543
	544	void
	545	scm_init_vm (void)
	546	{
	547	scm_init_frames ();
	548	scm_init_instructions ();
	549	scm_init_objcodes ();
	550	scm_init_programs ();
	551
	552	scm_tc16_vm_cont = scm_make_smob_type ("vm-cont", 0);
	553	scm_set_smob_mark (scm_tc16_vm_cont, vm_cont_mark);
	554	scm_set_smob_free (scm_tc16_vm_cont, vm_cont_free);
	555
	556	scm_tc16_vm = scm_make_smob_type ("vm", 0);
	557	scm_set_smob_mark (scm_tc16_vm, vm_mark);
	558	scm_set_smob_free (scm_tc16_vm, vm_free);
	559	scm_set_smob_apply (scm_tc16_vm, scm_vm_apply, 1, 0, 1);
	560
	561	the_vm = scm_permanent_object (make_vm ());
	562
	563	#ifndef SCM_MAGIC_SNARFER
	564	#include "vm.x"
	565	#endif
	566	}
	567
	568	/*
	569	Local Variables:
	570	c-file-style: "gnu"
	571	End:
	572	*/