Function: make-indirect-buffer

make-indirect-buffer is an interactive function defined in buffer.c.

Signature

(make-indirect-buffer BASE-BUFFER NAME &optional CLONE INHIBIT-BUFFER-HOOKS)

Documentation

Create and return an indirect buffer for buffer BASE-BUFFER, named NAME.

BASE-BUFFER should be a live buffer, or the name of an existing buffer.

NAME should be a string which is not the name of an existing buffer.

Interactively, prompt for BASE-BUFFER (offering the current buffer as the default), and for NAME (offering as default the name of a recently used buffer).

Optional argument CLONE non-nil means preserve BASE-BUFFER's state, such as major and minor modes, in the indirect buffer. CLONE nil means the indirect buffer's state is reset to default values.

If optional argument INHIBIT-BUFFER-HOOKS is non-nil, the new buffer does not run the hooks kill-buffer-hook, kill-buffer-query-functions, and buffer-list-update-hook.

Interactively, CLONE and INHIBIT-BUFFER-HOOKS are nil.

View in manual

Probably introduced at or before Emacs version 19.29.

Key Bindings

Source Code

// Defined in /usr/src/emacs/src/buffer.c
{
  Lisp_Object buf, tem;
  struct buffer *b;

  CHECK_STRING (name);
  buf = Fget_buffer (name);
  if (!NILP (buf))
    error ("Buffer name `%s' is in use", SDATA (name));

  tem = base_buffer;
  base_buffer = Fget_buffer (base_buffer);
  if (NILP (base_buffer))
    error ("No such buffer: `%s'", SDATA (tem));
  if (!BUFFER_LIVE_P (XBUFFER (base_buffer)))
    error ("Base buffer has been killed");

  if (SCHARS (name) == 0)
    error ("Empty string for buffer name is not allowed");

  b = allocate_buffer ();

  /* No double indirection - if base buffer is indirect,
     new buffer becomes an indirect to base's base.  */
  b->base_buffer = (XBUFFER (base_buffer)->base_buffer
		    ? XBUFFER (base_buffer)->base_buffer
		    : XBUFFER (base_buffer));

  /* Use the base buffer's text object.  */
  b->text = b->base_buffer->text;
  /* We have no own text.  */
  b->indirections = -1;
  /* Notify base buffer that we share the text now.  */
  b->base_buffer->indirections++;
  /* Always -1 for an indirect buffer.  */
  b->window_count = -1;

  memset (&b->local_flags, 0, sizeof (b->local_flags));

  b->pt = b->base_buffer->pt;
  b->begv = b->base_buffer->begv;
  b->zv = b->base_buffer->zv;
  b->pt_byte = b->base_buffer->pt_byte;
  b->begv_byte = b->base_buffer->begv_byte;
  b->zv_byte = b->base_buffer->zv_byte;
  b->inhibit_buffer_hooks = !NILP (inhibit_buffer_hooks);

  b->newline_cache = 0;
  b->width_run_cache = 0;
  b->bidi_paragraph_cache = 0;
  bset_width_table (b, Qnil);

#ifdef HAVE_TREE_SITTER
  /* By default, use empty linecol, which means disable tracking.  */
  SET_BUF_TS_LINECOL_BEGV (b, TREESIT_EMPTY_LINECOL);
  SET_BUF_TS_LINECOL_POINT (b, TREESIT_EMPTY_LINECOL);
  SET_BUF_TS_LINECOL_ZV (b, TREESIT_EMPTY_LINECOL);
#endif

  name = Fcopy_sequence (name);
  set_string_intervals (name, NULL);
  bset_name (b, name);
  bset_last_name (b, name);

  /* An indirect buffer shares undo list of its base (Bug#18180).  */
  bset_undo_list (b, BVAR (b->base_buffer, undo_list));

  reset_buffer (b);
  reset_buffer_local_variables (b, 1);

  /* Put this in the alist of all live buffers.  */
  XSETBUFFER (buf, b);
  Vbuffer_alist = nconc2 (Vbuffer_alist, list1 (Fcons (name, buf)));

  bset_mark (b, Fmake_marker ());

  /* The multibyte status belongs to the base buffer.  */
  bset_enable_multibyte_characters
    (b, BVAR (b->base_buffer, enable_multibyte_characters));

  /* Make sure the base buffer has markers for its narrowing.  */
  if (NILP (BVAR (b->base_buffer, pt_marker)))
    {
      eassert (NILP (BVAR (b->base_buffer, begv_marker)));
      eassert (NILP (BVAR (b->base_buffer, zv_marker)));

      bset_pt_marker (b->base_buffer,
		      build_marker (b->base_buffer, b->base_buffer->pt,
				    b->base_buffer->pt_byte));

      bset_begv_marker (b->base_buffer,
			build_marker (b->base_buffer, b->base_buffer->begv,
				      b->base_buffer->begv_byte));

      bset_zv_marker (b->base_buffer,
		      build_marker (b->base_buffer, b->base_buffer->zv,
				    b->base_buffer->zv_byte));

      XMARKER (BVAR (b->base_buffer, zv_marker))->insertion_type = 1;
    }

  if (NILP (clone))
    {
      /* Give the indirect buffer markers for its narrowing.  */
      bset_pt_marker (b, build_marker (b, b->pt, b->pt_byte));
      bset_begv_marker (b, build_marker (b, b->begv, b->begv_byte));
      bset_zv_marker (b, build_marker (b, b->zv, b->zv_byte));
      XMARKER (BVAR (b, zv_marker))->insertion_type = 1;
    }
  else
    {
      struct buffer *old_b = current_buffer;

      clone_per_buffer_values (b->base_buffer, b);
      bset_filename (b, Qnil);
      bset_file_truename (b, Qnil);
      bset_display_count (b, make_fixnum (0));
      bset_backed_up (b, Qnil);
      bset_local_minor_modes (b, Qnil);
      bset_auto_save_file_name (b, Qnil);
      set_buffer_internal_1 (b);
      Fset (Qbuffer_save_without_query, Qnil);
      Fset (Qbuffer_file_number, Qnil);
      if (!NILP (Flocal_variable_p (Qbuffer_stale_function, base_buffer)))
	Fkill_local_variable (Qbuffer_stale_function);
      /* Cloned buffers need extra setup, to do things such as deep
	 variable copies for list variables that might be mangled due
	 to destructive operations in the indirect buffer. */
      run_hook (Qclone_indirect_buffer_hook);
      set_buffer_internal_1 (old_b);
    }

  run_buffer_list_update_hook (b);

  return buf;
}