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* src/frame.c (delete_frame): Remove outdated comment.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, 5 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 86c8b695e24..e7b977c2dfa 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -49,6 +49,11 @@ directories to the search path.  You must add them yourself if you want them.
 (from the bin and libexec directories, respectively).  The former is
 no longer relevant, the latter is replaced by lisp (in vc-sccs.el).
 
+** The configuration option '--enable-use-lisp-union-type' has been
+renamed to '--enable-check-lisp-object-type', as the resulting
+Lisp_Object type no longer uses a union to implement the compile time
+check that this option enables.
+
 
 * Startup Changes in Emacs 24.2