--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lisp-union.h	Mon Aug 13 11:28:15 2007 +0200
@@ -0,0 +1,152 @@
+/* Fundamental definitions for XEmacs Lisp interpreter -- union objects.
+   Copyright (C) 1985, 1986, 1987, 1992, 1993, 1994
+   Free Software Foundation, Inc.
+
+This file is part of XEmacs.
+
+XEmacs is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with XEmacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* Divergent from FSF.  */
+
+/* Definition of Lisp_Object type as a union.
+   The declaration order of the objects within the struct members
+   of the union is dependent on ENDIAN-ness.
+   See lisp-disunion.h for more details.  */
+
+typedef
+union Lisp_Object
+{
+  /* if non-valbits are at lower addresses */
+#if defined(WORDS_BIGENDIAN)
+  struct
+  {
+    EMACS_UINT val : VALBITS;
+    enum_field (Lisp_Type) type : GCTYPEBITS;
+  } gu;
+
+  struct
+  {
+    signed EMACS_INT val : INT_VALBITS;
+    unsigned int bits : INT_GCBITS;
+  } s;
+
+  struct
+  {
+    EMACS_UINT val : INT_VALBITS;
+    unsigned int bits : INT_GCBITS;
+  } u;
+#else /* non-valbits are at higher addresses */
+  struct
+  {
+    enum_field (Lisp_Type) type : GCTYPEBITS;
+    EMACS_UINT val : VALBITS;
+  } gu;
+
+  struct
+  {
+    unsigned int bits : INT_GCBITS;
+    signed EMACS_INT val : INT_VALBITS;
+  } s;
+
+  struct
+  {
+    unsigned int bits : INT_GCBITS;
+    EMACS_UINT val : INT_VALBITS;
+  } u;
+
+#endif /* non-valbits are at higher addresses */
+
+  EMACS_UINT ui;
+  signed EMACS_INT i;
+
+  /* This was formerly declared 'void *v' etc. but that causes
+     GCC to accept any (yes, any) pointer as the argument of
+     a function declared to accept a Lisp_Object. */
+  struct nosuchstruct *v;
+  CONST struct nosuchstruct *cv;
+}
+Lisp_Object;
+
+#define XCHARVAL(x) ((x).gu.val)
+
+# define XSETINT(var, value) do {	\
+  EMACS_INT xset_value = (value);	\
+  Lisp_Object *xset_var = &(var);	\
+  xset_var->s.bits = 1;			\
+  xset_var->s.val = xset_value;		\
+} while (0)
+# define XSETCHAR(var, value) do {	\
+  Emchar xset_value = (value);		\
+  Lisp_Object *xset_var = &(var);	\
+  xset_var->gu.type = Lisp_Type_Char;	\
+  xset_var->gu.val = xset_value;	\
+} while (0)
+# define XSETOBJ(var, vartype, value) do {	\
+  EMACS_UINT xset_value = (EMACS_UINT) (value);	\
+  (var).ui = xset_value;			\
+} while (0)
+# define XPNTRVAL(x) ((x).ui)
+
+INLINE Lisp_Object make_int (EMACS_INT val);
+INLINE Lisp_Object
+make_int (EMACS_INT val)
+{
+  Lisp_Object obj;
+  XSETINT(obj, val);
+  return obj;
+}
+
+INLINE Lisp_Object make_char (Emchar val);
+INLINE Lisp_Object
+make_char (Emchar val)
+{
+  Lisp_Object obj;
+  XSETCHAR(obj, val);
+  return obj;
+}
+
+extern Lisp_Object Qnull_pointer, Qzero;
+
+#define XREALINT(x) ((x).s.val)
+#define XUINT(x) ((x).u.val)
+#define XTYPE(x) ((x).gu.type)
+#define EQ(x,y) ((x).v == (y).v)
+
+#define INTP(x) ((x).s.bits)
+#define INT_PLUS(x,y)  make_int (XINT (x) + XINT (y))
+#define INT_MINUS(x,y) make_int (XINT (x) - XINT (y))
+#define INT_PLUS1(x)   make_int (XINT (x) + 1)
+#define INT_MINUS1(x)  make_int (XINT (x) - 1)
+
+/* Convert between a (void *) and a Lisp_Object, as when the
+   Lisp_Object is passed to a toolkit callback function */
+#define VOID_TO_LISP(larg,varg) \
+     ((void) ((larg).v = (struct nosuchstruct *) (varg)))
+#define CVOID_TO_LISP(larg,varg) \
+     ((void) ((larg).cv = (CONST struct nosuchstruct *) (varg)))
+#define LISP_TO_VOID(larg) ((void *) ((larg).v))
+#define LISP_TO_CVOID(larg) ((CONST void *) ((larg).cv))
+
+/* Convert a Lisp_Object into something that can't be used as an
+   lvalue.  Useful for type-checking. */
+#if (__GNUC__ > 1)
+#define NON_LVALUE(larg) ({ (larg); })
+#else
+/* Well, you can't really do it without using a function call, and
+   there's no real point in that; no-union-type is the rule, and that
+   will catch errors. */
+#define NON_LVALUE(larg) (larg)
+#endif