Use a simple struct to implement compile time checks for the Lisp_Object type

* configure.in: Rename --enable-use-lisp-union-type to
--enable-check-lisp-object-type and define CHECK_LISP_OBJECT_TYPE
instead of USE_LISP_UNION_TYPE.

* admin/make-emacs: Rename --union-type to --check-lisp-type.  Define
CHECK_LISP_OBJECT_TYPE insted of USE_LISP_UNION_TYPE.
* admin/CPP-DEFINES (DEBUG_LISP_OBJECT_TYPE): Renamed from
USE_LISP_UNION_TYPE.

* src/lisp.h (Lisp_Object) [CHECK_LISP_OBJECT_TYPE]: Define as struct
instead of union.
(XLI, XIL): Define.
(XHASH, XTYPE, XINT, XUINT, make_number, XSET, XPNTR, XUNTAG): Use
them.
* src/emacs.c (gdb_use_struct): Renamed from gdb_use_union.
* src/.gdbinit: Check gdb_use_struct instead of gdb_use_union.
* src/alloc.c (widen_to_Lisp_Object): Removed.
(mark_memory): Use XIL instead of widen_to_Lisp_Object.
* src/frame.c (delete_frame): Remove outdated comment.
* src/w32fns.c (Fw32_register_hot_key): Use XLI instead of checking
USE_LISP_UNION_TYPE.
(Fw32_unregister_hot_key): Likewise.
(Fw32_toggle_lock_key): Likewise.
* src/w32menu.c (add_menu_item): Likewise.
(w32_menu_display_help): Use XIL instead of checking
USE_LISP_UNION_TYPE.
* src/w32heap.c (allocate_heap): Don't check USE_LISP_UNION_TYPE.
(init_heap): Likewise.
* src/w32term.c (w32_read_socket): Update comment.

1 files changed, 1 insertions, 16 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 1223f0bc13d..1478ce9ae4e 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -1585,21 +1585,6 @@ mark_interval_tree (register INTERVAL tree)
      (i) = balance_intervals (i);                       \
   } while (0)
 
-/* Convert the pointer-sized word P to EMACS_INT while preserving its
-   type and ptr fields.  */
-static Lisp_Object
-widen_to_Lisp_Object (void *p)
-{
-  intptr_t i = (intptr_t) p;
-#ifdef USE_LISP_UNION_TYPE
-  Lisp_Object obj;
-  obj.i = i;
-  return obj;
-#else
-  return i;
-#endif
-}
-
 /***********************************************************************
                           String Allocation
  ***********************************************************************/
@@ -4678,7 +4663,7 @@ mark_memory (void *start, void *end)
         void *p = *(void **) ((char *) pp + i);
         mark_maybe_pointer (p);
         if (POINTERS_MIGHT_HIDE_IN_OBJECTS)
-          mark_maybe_object (widen_to_Lisp_Object (p));
+          mark_maybe_object (XIL ((intptr_t) p));
       }
 }