Reimplement Lisp_Object as pointer-to-incomplete

This makes Lisp_Object values opaque pointers instead of integers,
which helps avoid the same sort of typos that
CHECK_LISP_OBJECT_TYPE helps to avoid, without having to wrap
pointers inside structures.  This also looks forward to supporting
-fcheck-pointer-bounds.
* etc/DEBUG:
* src/.gdbinit (Lisp_Object_Printer.to_string):
Lisp_Object can be a pointer type now.
* src/alloc.c (macro_XPNTR, XPNTR):
* src/emacs-module.c (value_to_lisp_bits, lisp_to_value_bits):
* src/lisp.h (lisp_h_XLI, lisp_h_XIL):
(lisp_h_XUNTAG) [USE_LSB_TAG]:
(XUNTAG) [!USE_LSB_TAG]:
(Lisp_Object, TAG_PTR, make_lisp_symbol):
Support new Lisp_Object implementation as a pointer to an
incomplete type.  Keep pointers pointers, as much as possible.
* src/alloc.c (macro_XPNTR_OR_SYMBOL_OFFSET, XPNTR_OR_SYMBOL_OFFSET):
Remove.  All uses replaced by plain XPNTR.
* src/emacs-module.c: Work around GCC bug 83162.
* src/lisp.h (LISP_WORDS_ARE_POINTERS, lisp_h_XLP, lisp_h_XPL):
(XLP, XPL) [DEFINE_KEY_OPS_AS_MACROS]:
New macros.
(Lisp_Word, untagged_ptr, Lisp_Word_tag): New types.
(XLP, XPL): New inline functions.
(TAG_PTR): Now expands to an initializer, not an expression.
All uses changed.
(TAG_SYMOFFSET, XLI_BUILTIN_LISPSYM): Remove.  All uses removed.
(LISPSYM_INITIALLY): Redo in terms of the new TAG_PTR.
(NIL_IS_ZERO): Redo without XLI_BUILTIN_LISPSYM.
* src/xwidget.c (webkit_javascript_finished_cb): Use XPL
instead of XIL with a non-EMACS_INT arg.
(Fxwidget_webkit_execute_script): Use XLP instead of XLI
followed by two conversions.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/xwidget.c b/src/xwidget.c
index a67dc0ecf4d..c7f0594728c 100644
--- a/src/xwidget.c
+++ b/src/xwidget.c
@@ -392,8 +392,7 @@ webkit_javascript_finished_cb (GObject      *webview,
     /* FIXME: This might lead to disaster if LISP_CALLBACK’s object
        was garbage collected before now.  See the FIXME in
        Fxwidget_webkit_execute_script.  */
-    store_xwidget_js_callback_event (xw, XIL ((intptr_t) lisp_callback),
-                                     lisp_value);
+    store_xwidget_js_callback_event (xw, XPL (lisp_callback), lisp_value);
 }
 
 
@@ -723,7 +722,7 @@ argument procedure FUN.*/)
   /* FIXME: This hack might lead to disaster if FUN is garbage
      collected before store_xwidget_js_callback_event makes it visible
      to Lisp again.  See the FIXME in webkit_javascript_finished_cb.  */
-  gpointer callback_arg = (gpointer) (intptr_t) XLI (fun);
+  gpointer callback_arg = XLP (fun);
 
   /* JavaScript execution happens asynchronously.  If an elisp
      callback function is provided we pass it to the C callback