Cleanup miscellaneous objects allocation and initialization.

* alloc.c (allocate_misc): Change to static.  Add argument to
specify the subtype.  Adjust comment and users.
(build_overlay): New function.
* buffer.c (copy_overlays, Fmake_overlay): Use it.
* lisp.h (struct Lisp_Overlay): Remove obsolete comment.
(allocate_misc): Remove prototype.
(build_overlay): Add prototype.

4 files changed, 38 insertions, 33 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index bc486a99bd4..fb25d8dc937 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,4 +1,15 @@
-2012-07-22  Dmitry Antipov  <dmantipov@yandex.ru>
+2012-07-23  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	Cleanup miscellaneous objects allocation and initialization.
+	* alloc.c (allocate_misc): Change to static.  Add argument to
+	specify the subtype.  Adjust comment and users.
+	(build_overlay): New function.
+	* buffer.c (copy_overlays, Fmake_overlay): Use it.
+	* lisp.h (struct Lisp_Overlay): Remove obsolete comment.
+	(allocate_misc): Remove prototype.
+	(build_overlay): Add prototype.
+
+2012-07-23  Dmitry Antipov  <dmantipov@yandex.ru>
 
 	Swap buffer text indirection counters in Fbuffer_swap_text.
 	* buffer.c (Fbuffer_swap_text): Swap indirections too.
diff --git a/src/alloc.c b/src/alloc.c
index 9f3c2a2ed4b..d9c56b5c7c8 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3564,10 +3564,10 @@ static int marker_block_index = MARKER_BLOCK_SIZE;
 
 static union Lisp_Misc *marker_free_list;
 
-/* Return a newly allocated Lisp_Misc object, with no substructure.  */
+/* Return a newly allocated Lisp_Misc object of specified TYPE.  */
 
-Lisp_Object
-allocate_misc (void)
+static Lisp_Object
+allocate_misc (enum Lisp_Misc_Type type)
 {
   Lisp_Object val;
 
@@ -3599,6 +3599,7 @@ allocate_misc (void)
   --total_free_markers;
   consing_since_gc += sizeof (union Lisp_Misc);
   misc_objects_consed++;
+  XMISCTYPE (val) = type;
   XMISCANY (val)->gcmarkbit = 0;
   return val;
 }
@@ -3625,8 +3626,7 @@ make_save_value (void *pointer, ptrdiff_t integer)
   register Lisp_Object val;
   register struct Lisp_Save_Value *p;
 
-  val = allocate_misc ();
-  XMISCTYPE (val) = Lisp_Misc_Save_Value;
+  val = allocate_misc (Lisp_Misc_Save_Value);
   p = XSAVE_VALUE (val);
   p->pointer = pointer;
   p->integer = integer;
@@ -3634,6 +3634,21 @@ make_save_value (void *pointer, ptrdiff_t integer)
   return val;
 }
 
+/* Return a Lisp_Misc_Overlay object with specified START, END and PLIST.  */
+
+Lisp_Object
+build_overlay (Lisp_Object start, Lisp_Object end, Lisp_Object plist)
+{
+  register Lisp_Object overlay;
+
+  overlay = allocate_misc (Lisp_Misc_Overlay);
+  OVERLAY_START (overlay) = start;
+  OVERLAY_END (overlay) = end;
+  OVERLAY_PLIST (overlay) = plist;
+  XOVERLAY (overlay)->next = NULL;
+  return overlay;
+}
+
 DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
        doc: /* Return a newly allocated marker which does not point at any place.  */)
   (void)
@@ -3641,8 +3656,7 @@ DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
   register Lisp_Object val;
   register struct Lisp_Marker *p;
 
-  val = allocate_misc ();
-  XMISCTYPE (val) = Lisp_Misc_Marker;
+  val = allocate_misc (Lisp_Misc_Marker);
   p = XMARKER (val);
   p->buffer = 0;
   p->bytepos = 0;
@@ -3667,8 +3681,7 @@ build_marker (struct buffer *buf, ptrdiff_t charpos, ptrdiff_t bytepos)
   /* Every character is at least one byte.  */
   eassert (charpos <= bytepos);
 
-  obj = allocate_misc ();
-  XMISCTYPE (obj) = Lisp_Misc_Marker;
+  obj = allocate_misc (Lisp_Misc_Marker);
   m = XMARKER (obj);
   m->buffer = buf;
   m->charpos = charpos;
diff --git a/src/buffer.c b/src/buffer.c
index 68208d17abe..734ddb5a1c1 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -433,12 +433,8 @@ copy_overlays (struct buffer *b, struct Lisp_Overlay *list)
       XMARKER (end)->insertion_type
 	= XMARKER (OVERLAY_END (old_overlay))->insertion_type;
 
-      overlay = allocate_misc ();
-      XMISCTYPE (overlay) = Lisp_Misc_Overlay;
-      OVERLAY_START (overlay) = start;
-      OVERLAY_END (overlay) = end;
-      OVERLAY_PLIST (overlay) = Fcopy_sequence (OVERLAY_PLIST (old_overlay));
-      XOVERLAY (overlay)->next = NULL;
+      overlay = build_overlay
+	(start, end, Fcopy_sequence (OVERLAY_PLIST (old_overlay)));
 
       if (tail)
 	tail = tail->next = XOVERLAY (overlay);
@@ -3640,12 +3636,7 @@ for the rear of the overlay advance when text is inserted there
   if (!NILP (rear_advance))
     XMARKER (end)->insertion_type = 1;
 
-  overlay = allocate_misc ();
-  XMISCTYPE (overlay) = Lisp_Misc_Overlay;
-  XOVERLAY (overlay)->start = beg;
-  XOVERLAY (overlay)->end = end;
-  XOVERLAY (overlay)->plist = Qnil;
-  XOVERLAY (overlay)->next = NULL;
+  overlay = build_overlay (beg, end, Qnil);
 
   /* Put the new overlay on the wrong list.  */
   end = OVERLAY_END (overlay);
diff --git a/src/lisp.h b/src/lisp.h
index 2f426c38fc5..e34a66af0c8 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1286,16 +1286,6 @@ struct Lisp_Marker
 /* START and END are markers in the overlay's buffer, and
    PLIST is the overlay's property list.  */
 struct Lisp_Overlay
-/* An overlay's real data content is:
-   - plist
-   - buffer
-   - insertion type of both ends
-   - start & start_byte
-   - end & end_byte
-   - next (singly linked list of overlays).
-   - start_next and end_next (singly linked list of markers).
-   I.e. 9words plus 2 bits, 3words of which are for external linked lists.
-*/
   {
     ENUM_BF (Lisp_Misc_Type) type : 16;	/* = Lisp_Misc_Overlay */
     unsigned gcmarkbit : 1;
@@ -2605,7 +2595,6 @@ extern Lisp_Object list3 (Lisp_Object, Lisp_Object, Lisp_Object);
 extern Lisp_Object list4 (Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object);
 extern Lisp_Object list5 (Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object,
 			  Lisp_Object);
-extern Lisp_Object allocate_misc (void);
 extern _Noreturn void string_overflow (void);
 extern Lisp_Object make_string (const char *, ptrdiff_t);
 extern Lisp_Object make_formatted_string (char *, const char *, ...)
@@ -2667,6 +2656,7 @@ extern Lisp_Object make_float (double);
 extern void display_malloc_warning (void);
 extern ptrdiff_t inhibit_garbage_collection (void);
 extern Lisp_Object make_save_value (void *, ptrdiff_t);
+extern Lisp_Object build_overlay (Lisp_Object, Lisp_Object, Lisp_Object);
 extern void free_marker (Lisp_Object);
 extern void free_cons (struct Lisp_Cons *);
 extern void init_alloc_once (void);