Cleanup basic buffer management.

* buffer.h (struct buffer): Change layout to use generic vector
marking code.  Fix some comments.  Change type of 'clip_changed'
to bitfield.  Remove unused #ifndef old.
(FIRST_FIELD_PER_BUFFER, LAST_FIELD_PER_BUFFER): Remove.
(GET_OVERLAYS_AT): Fix indentation.
(for_each_per_buffer_object_at): New macro.
* buffer.c (clone_per_buffer_values, reset_buffer_local_variables)
(Fbuffer_local_variables): Use it.
(init_buffer_once, syms_of_buffer): Remove unused #ifndef old.
* alloc.c (allocate_buffer): Adjust to match new layout of
struct buffer.  Fix comment.
(mark_overlay): New function.
(mark_buffer): Use it.  Use mark_vectorlike to mark normal
Lisp area of struct buffer.
(mark_object): Use it.  Adjust marking of misc objects
and related comments.

1 files changed, 4 insertions, 25 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 89a4e26fb73..08118baa3d7 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -465,11 +465,7 @@ clone_per_buffer_values (struct buffer *from, struct buffer *to)
 
   XSETBUFFER (to_buffer, to);
 
-  /* buffer-local Lisp variables start at `undo_list',
-     tho only the ones from `name' on are GC'd normally.  */
-  for (offset = PER_BUFFER_VAR_OFFSET (FIRST_FIELD_PER_BUFFER);
-       offset <= PER_BUFFER_VAR_OFFSET (LAST_FIELD_PER_BUFFER);
-       offset += sizeof (Lisp_Object))
+  for_each_per_buffer_object_at (offset)
     {
       Lisp_Object obj;
 
@@ -820,14 +816,8 @@ reset_buffer_local_variables (register struct buffer *b, int permanent_too)
     if (permanent_too || buffer_permanent_local_flags[i] == 0)
       SET_PER_BUFFER_VALUE_P (b, i, 0);
 
-  /* For each slot that has a default value,
-     copy that into the slot.  */
-
-  /* buffer-local Lisp variables start at `undo_list',
-     tho only the ones from `name' on are GC'd normally.  */
-  for (offset = PER_BUFFER_VAR_OFFSET (FIRST_FIELD_PER_BUFFER);
-       offset <= PER_BUFFER_VAR_OFFSET (LAST_FIELD_PER_BUFFER);
-       offset += sizeof (Lisp_Object))
+  /* For each slot that has a default value, copy that into the slot.  */
+  for_each_per_buffer_object_at (offset)
     {
       int idx = PER_BUFFER_IDX (offset);
       if ((idx > 0
@@ -1063,12 +1053,7 @@ No argument or nil as argument means use current buffer as BUFFER.  */)
   {
     int offset, idx;
 
-    /* buffer-local Lisp variables start at `undo_list',
-       tho only the ones from `name' on are GC'd normally.  */
-    for (offset = PER_BUFFER_VAR_OFFSET (FIRST_FIELD_PER_BUFFER);
-         offset <= PER_BUFFER_VAR_OFFSET (LAST_FIELD_PER_BUFFER);
-         /* sizeof EMACS_INT == sizeof Lisp_Object */
-         offset += (sizeof (EMACS_INT)))
+    for_each_per_buffer_object_at (offset)
       {
         idx = PER_BUFFER_IDX (offset);
         if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
@@ -4903,9 +4888,7 @@ init_buffer_once (void)
   BVAR (&buffer_defaults, case_fold_search) = Qt;
   BVAR (&buffer_defaults, auto_fill_function) = Qnil;
   BVAR (&buffer_defaults, selective_display) = Qnil;
-#ifndef old
   BVAR (&buffer_defaults, selective_display_ellipses) = Qt;
-#endif
   BVAR (&buffer_defaults, abbrev_table) = Qnil;
   BVAR (&buffer_defaults, display_table) = Qnil;
   BVAR (&buffer_defaults, undo_list) = Qnil;
@@ -4984,9 +4967,7 @@ init_buffer_once (void)
   XSETFASTINT (BVAR (&buffer_local_flags, case_fold_search), idx); ++idx;
   XSETFASTINT (BVAR (&buffer_local_flags, auto_fill_function), idx); ++idx;
   XSETFASTINT (BVAR (&buffer_local_flags, selective_display), idx); ++idx;
-#ifndef old
   XSETFASTINT (BVAR (&buffer_local_flags, selective_display_ellipses), idx); ++idx;
-#endif
   XSETFASTINT (BVAR (&buffer_local_flags, tab_width), idx); ++idx;
   XSETFASTINT (BVAR (&buffer_local_flags, truncate_lines), idx); ++idx;
   XSETFASTINT (BVAR (&buffer_local_flags, word_wrap), idx); ++idx;
@@ -5594,12 +5575,10 @@ A value of t means that the character ^M makes itself and
 all the rest of the line invisible; also, when saving the buffer
 in a file, save the ^M as a newline.  */);
 
-#ifndef old
   DEFVAR_PER_BUFFER ("selective-display-ellipses",
                      &BVAR (current_buffer, selective_display_ellipses),
                      Qnil,
                      doc: /* Non-nil means display ... on previous line when a line is invisible.  */);
-#endif
 
   DEFVAR_PER_BUFFER ("overwrite-mode", &BVAR (current_buffer, overwrite_mode), Qnil,
                      doc: /* Non-nil if self-insertion should replace existing text.