C++ Fcons函數代碼示例

static void
record_point (ptrdiff_t pt)
{
  bool at_boundary;

  /* Don't record position of pt when undo_inhibit_record_point holds.  */
  if (undo_inhibit_record_point)
    return;

  /* Allocate a cons cell to be the undo boundary after this command.  */
  if (NILP (pending_boundary))
    pending_boundary = Fcons (Qnil, Qnil);

  run_undoable_change ();

  at_boundary = ! CONSP (BVAR (current_buffer, undo_list))
                || NILP (XCAR (BVAR (current_buffer, undo_list)));

  if (MODIFF <= SAVE_MODIFF)
    record_first_change ();

  /* If we are just after an undo boundary, and
     point wasn't at start of deleted range, record where it was.  */
  if (at_boundary
      && current_buffer == last_boundary_buffer
      && last_boundary_position != pt)
    bset_undo_list (current_buffer,
		    Fcons (make_number (last_boundary_position),
			   BVAR (current_buffer, undo_list)));
}

/* As above, but return the menu selection instead of storing in kb buffer.
   If keymaps==1, return full prefixes to selection. */
Lisp_Object
find_and_return_menu_selection (FRAME_PTR f, int keymaps, void *client_data)
{
  Lisp_Object prefix, entry;
  int i;
  Lisp_Object *subprefix_stack;
  int submenu_depth = 0;

  prefix = entry = Qnil;
  i = 0;
  subprefix_stack =
    (Lisp_Object *)alloca(menu_items_used * sizeof (Lisp_Object));

  while (i < menu_items_used)
    {
      if (EQ (XVECTOR (menu_items)->contents[i], Qnil))
        {
          subprefix_stack[submenu_depth++] = prefix;
          prefix = entry;
          i++;
        }
      else if (EQ (XVECTOR (menu_items)->contents[i], Qlambda))
        {
          prefix = subprefix_stack[--submenu_depth];
          i++;
        }
      else if (EQ (XVECTOR (menu_items)->contents[i], Qt))
        {
          prefix
            = XVECTOR (menu_items)->contents[i + MENU_ITEMS_PANE_PREFIX];
          i += MENU_ITEMS_PANE_LENGTH;
        }
      /* Ignore a nil in the item list.
         It's meaningful only for dialog boxes.  */
      else if (EQ (XVECTOR (menu_items)->contents[i], Qquote))
        i += 1;
      else
        {
          entry
            = XVECTOR (menu_items)->contents[i + MENU_ITEMS_ITEM_VALUE];
          if ((EMACS_INT)client_data ==  (EMACS_INT)(&XVECTOR (menu_items)->contents[i]))
            {
              if (keymaps != 0)
                {
                  int j;

                  entry = Fcons (entry, Qnil);
                  if (!NILP (prefix))
                    entry = Fcons (prefix, entry);
                  for (j = submenu_depth - 1; j >= 0; j--)
                    if (!NILP (subprefix_stack[j]))
                      entry = Fcons (subprefix_stack[j], entry);
                }
              return entry;
            }
          i += MENU_ITEMS_ITEM_LENGTH;
        }
    }
  return Qnil;
}

void
record_delete (ptrdiff_t beg, Lisp_Object string, bool record_markers)
{
  Lisp_Object sbeg;

  if (EQ (BVAR (current_buffer, undo_list), Qt))
    return;

  if (PT == beg + SCHARS (string))
    {
      XSETINT (sbeg, -beg);
      record_point (PT);
    }
  else
    {
      XSETFASTINT (sbeg, beg);
      record_point (beg);
    }

  /* primitive-undo assumes marker adjustments are recorded
     immediately before the deletion is recorded.  See bug 16818
     discussion.  */
  if (record_markers)
    record_marker_adjustments (beg, beg + SCHARS (string));

  bset_undo_list
    (current_buffer,
     Fcons (Fcons (string, sbeg), BVAR (current_buffer, undo_list)));
}

/* Add a new watch to watch-descriptor WD watching FILENAME and using
   IMASK and CALLBACK.  Return a cons (DESCRIPTOR . ID) uniquely
   identifying the new watch.  */
static Lisp_Object
add_watch (int wd, Lisp_Object filename,
	   uint32_t imask, Lisp_Object callback)
{
  Lisp_Object descriptor = INTEGER_TO_CONS (wd);
  Lisp_Object tail = assoc_no_quit (descriptor, watch_list);
  Lisp_Object watch, watch_id;
  Lisp_Object mask = INTEGER_TO_CONS (imask);

  EMACS_INT id = 0;
  if (NILP (tail))
    {
      tail = list1 (descriptor);
      watch_list = Fcons (tail, watch_list);
    }
  else
    {
      /* Assign a watch ID that is not already in use, by looking
	 for a gap in the existing sorted list.  */
      for (; ! NILP (XCDR (tail)); tail = XCDR (tail), id++)
	if (!EQ (XCAR (XCAR (XCDR (tail))), make_number (id)))
	  break;
      if (MOST_POSITIVE_FIXNUM < id)
	emacs_abort ();
    }

  /* Insert the newly-assigned ID into the previously-discovered gap,
     which is possibly at the end of the list.  Inserting it there
     keeps the list sorted.  */
  watch_id = make_number (id);
  watch = list4 (watch_id, filename, callback, mask);
  XSETCDR (tail, Fcons (watch, XCDR (tail)));

  return Fcons (descriptor, watch_id);
}

void
record_insert (ptrdiff_t beg, ptrdiff_t length)
{
  Lisp_Object lbeg, lend;

  if (EQ (BVAR (current_buffer, undo_list), Qt))
    return;

  record_point (beg);

  /* If this is following another insertion and consecutive with it
     in the buffer, combine the two.  */
  if (CONSP (BVAR (current_buffer, undo_list)))
    {
      Lisp_Object elt;
      elt = XCAR (BVAR (current_buffer, undo_list));
      if (CONSP (elt)
	  && INTEGERP (XCAR (elt))
	  && INTEGERP (XCDR (elt))
	  && XINT (XCDR (elt)) == beg)
	{
	  XSETCDR (elt, make_number (beg + length));
	  return;
	}
    }

  XSETFASTINT (lbeg, beg);
  XSETINT (lend, beg + length);
  bset_undo_list (current_buffer,
		  Fcons (Fcons (lbeg, lend), BVAR (current_buffer, undo_list)));
}

static bool
init_libxml2_functions (void)
{
#ifdef WINDOWSNT
    if (libxml2_loaded_p ())
        return true;
    else
    {
        HMODULE library;

        if (!(library = w32_delayed_load (Qlibxml2)))
        {
            message1 ("libxml2 library not found");
            return false;
        }

        if (! load_dll_functions (library))
            goto bad_library;

        Vlibrary_cache = Fcons (Fcons (Qlibxml2, Qt), Vlibrary_cache);
        return true;
    }

bad_library:
    Vlibrary_cache = Fcons (Fcons (Qlibxml2, Qnil), Vlibrary_cache);

    return false;
#else  /* !WINDOWSNT */
    return true;
#endif	/* !WINDOWSNT */
}

/* Generate a file notification event.  */
static void
kqueue_generate_event (Lisp_Object watch_object, Lisp_Object actions,
		       Lisp_Object file, Lisp_Object file1)
{
  Lisp_Object flags, action, entry;
  struct input_event event;

  /* Check, whether all actions shall be monitored.  */
  flags = Fnth (make_number (2), watch_object);
  action = actions;
  do {
    if (NILP (action))
      break;
    entry = XCAR (action);
    if (NILP (Fmember (entry, flags))) {
      action = XCDR (action);
      actions = Fdelq (entry, actions);
    } else
      action = XCDR (action);
  } while (1);

  /* Store it into the input event queue.  */
  if (! NILP (actions)) {
    EVENT_INIT (event);
    event.kind = FILE_NOTIFY_EVENT;
    event.frame_or_window = Qnil;
    event.arg = list2 (Fcons (XCAR (watch_object),
			      Fcons (actions,
				     NILP (file1)
				     ? Fcons (file, Qnil)
				     : list2 (file, file1))),
		       Fnth (make_number (3), watch_object));
    kbd_buffer_store_event (&event);
  }
}

/* As above, but return the menu selection instead of storing in kb buffer.
   If KEYMAPS, return full prefixes to selection. */
Lisp_Object
find_and_return_menu_selection (struct frame *f, bool keymaps, void *client_data)
{
  Lisp_Object prefix, entry;
  int i;
  Lisp_Object *subprefix_stack;
  int submenu_depth = 0;

  prefix = entry = Qnil;
  i = 0;
  subprefix_stack = alloca (menu_items_used * word_size);

  while (i < menu_items_used)
    {
      if (EQ (AREF (menu_items, i), Qnil))
        {
          subprefix_stack[submenu_depth++] = prefix;
          prefix = entry;
          i++;
        }
      else if (EQ (AREF (menu_items, i), Qlambda))
        {
          prefix = subprefix_stack[--submenu_depth];
          i++;
        }
      else if (EQ (AREF (menu_items, i), Qt))
        {
          prefix
            = AREF (menu_items, i + MENU_ITEMS_PANE_PREFIX);
          i += MENU_ITEMS_PANE_LENGTH;
        }
      /* Ignore a nil in the item list.
         It's meaningful only for dialog boxes.  */
      else if (EQ (AREF (menu_items, i), Qquote))
        i += 1;
      else
        {
          entry
            = AREF (menu_items, i + MENU_ITEMS_ITEM_VALUE);
          if (aref_addr (menu_items, i) == client_data)
            {
              if (keymaps)
                {
                  int j;

                  entry = list1 (entry);
                  if (!NILP (prefix))
                    entry = Fcons (prefix, entry);
                  for (j = submenu_depth - 1; j >= 0; j--)
                    if (!NILP (subprefix_stack[j]))
                      entry = Fcons (subprefix_stack[j], entry);
                }
              return entry;
            }
          i += MENU_ITEMS_ITEM_LENGTH;
        }
    }
  return Qnil;
}

static void
record_point (EMACS_INT pt)
{
  int at_boundary;

  /* Don't record position of pt when undo_inhibit_record_point holds.  */
  if (undo_inhibit_record_point)
    return;

  /* Allocate a cons cell to be the undo boundary after this command.  */
  if (NILP (pending_boundary))
    pending_boundary = Fcons (Qnil, Qnil);

  if ((current_buffer != last_undo_buffer)
      /* Don't call Fundo_boundary for the first change.  Otherwise we
	 risk overwriting last_boundary_position in Fundo_boundary with
	 PT of the current buffer and as a consequence not insert an
	 undo boundary because last_boundary_position will equal pt in
	 the test at the end of the present function (Bug#731).  */
      && (MODIFF > SAVE_MODIFF))
    Fundo_boundary ();
  last_undo_buffer = current_buffer;

  if (CONSP (BVAR (current_buffer, undo_list)))
    {
      /* Set AT_BOUNDARY to 1 only when we have nothing other than
         marker adjustment before undo boundary.  */

      Lisp_Object tail = BVAR (current_buffer, undo_list), elt;

      while (1)
	{
	  if (NILP (tail))
	    elt = Qnil;
	  else
	    elt = XCAR (tail);
	  if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt))))
	    break;
	  tail = XCDR (tail);
	}
      at_boundary = NILP (elt);
    }
  else
    at_boundary = 1;

  if (MODIFF <= SAVE_MODIFF)
    record_first_change ();

  /* If we are just after an undo boundary, and
     point wasn't at start of deleted range, record where it was.  */
  if (at_boundary
      && current_buffer == last_boundary_buffer
      && last_boundary_position != pt)
    BVAR (current_buffer, undo_list)
      = Fcons (make_number (last_boundary_position), BVAR (current_buffer, undo_list));
}

static Lisp_Object
make_dom (xmlNode *node)
{
  if (node->type == XML_ELEMENT_NODE)
    {
      Lisp_Object result = Fcons (intern ((char *) node->name), Qnil);
      xmlNode *child;
      xmlAttr *property;
      Lisp_Object plist = Qnil;

      /* First add the attributes. */
      property = node->properties;
      while (property != NULL)
	{
	  if (property->children &&
	      property->children->content)
	    {
	      char *content = (char *) property->children->content;
	      plist = Fcons (Fcons (intern ((char *) property->name),
				    build_string (content)),
			     plist);
	    }
	  property = property->next;
	}
      result = Fcons (Fnreverse (plist), result);

      /* Then add the children of the node. */
      child = node->children;
      while (child != NULL)
	{
	  result = Fcons (make_dom (child), result);
	  child = child->next;
	}

      return Fnreverse (result);
    }
  else if (node->type == XML_TEXT_NODE || node->type == XML_CDATA_SECTION_NODE)
    {
      if (node->content)
	return build_string ((char *) node->content);
      else
	return Qnil;
    }
  else if (node->type == XML_COMMENT_NODE)
    {
      if (node->content)
	return list3 (intern ("comment"), Qnil,
		      build_string ((char *) node->content));
      else
	return Qnil;
    }
  else
    return Qnil;
}

void gcpro_popup_callbacks(LWLIB_ID id)
{
	struct popup_data *pdata;
	Lisp_Object lid = make_int(id);
	Lisp_Object lpdata;

	assert(NILP(assq_no_quit(lid, Vpopup_callbacks)));
	pdata = alloc_lcrecord_type(struct popup_data, &lrecord_popup_data);
	pdata->id = id;
	pdata->last_menubar_buffer = Qnil;
	pdata->menubar_contents_up_to_date = 0;
	XSETPOPUP_DATA(lpdata, pdata);
	Vpopup_callbacks = Fcons(Fcons(lid, lpdata), Vpopup_callbacks);
}

void
record_first_change (void)
{
  struct buffer *base_buffer = current_buffer;

  if (EQ (BVAR (current_buffer, undo_list), Qt))
    return;

  if (base_buffer->base_buffer)
    base_buffer = base_buffer->base_buffer;

  bset_undo_list (current_buffer,
		  Fcons (Fcons (Qt, Fvisited_file_modtime ()),
			 BVAR (current_buffer, undo_list)));
}

/* Record point, if necessary, as it was at beginning of this command.
   BEG is the position of point that will naturally occur as a result
   of the undo record that will be added just after this command
   terminates.  */
static void
record_point (ptrdiff_t beg)
{
  /* Don't record position of pt when undo_inhibit_record_point holds.  */
  if (undo_inhibit_record_point)
    return;

  bool at_boundary;

  /* Check whether we are at a boundary now, in case we record the
  first change. FIXME: This check is currently dependent on being
  called before record_first_change, but could be made not to by
  ignoring timestamp undo entries */
  at_boundary = ! CONSP (BVAR (current_buffer, undo_list))
                || NILP (XCAR (BVAR (current_buffer, undo_list)));

  /* If this is the first change since save, then record this.*/
  if (MODIFF <= SAVE_MODIFF)
    record_first_change ();

  /* We may need to record point if we are immediately after a
     boundary, so that this will be restored correctly after undo. We
     do not need to do this if point is at the start of a change
     region since it will be restored there anyway, and we must not do
     this if the buffer has changed since the last command, since the
     value of point that we have will be for that buffer, not this.*/
  if (at_boundary
      && point_before_last_command_or_undo != beg
      && buffer_before_last_command_or_undo == current_buffer )
    bset_undo_list (current_buffer,
		    Fcons (make_number (point_before_last_command_or_undo),
			   BVAR (current_buffer, undo_list)));
}

/* Prepare the undo info for recording a change. */
static void
prepare_record (void)
{
  /* Allocate a cons cell to be the undo boundary after this command.  */
  if (NILP (pending_boundary))
    pending_boundary = Fcons (Qnil, Qnil);
}

static void
report_error (char *file, int fd)
{
  if (fd)
    close (fd);
  report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil));
}