[Emacs-diffs] /srv/bzr/emacs/trunk r110966: Conflate Qnil and Qunbound for `symbol-function'.

[Stefan Monnier]

------------------------------------------------------------
revno: 110966
committer: Stefan Monnier <address@hidden>
branch nick: trunk
timestamp: Tue 2012-11-20 15:06:17 -0500
message:
  Conflate Qnil and Qunbound for `symbol-function'.
  * src/alloc.c (Fmake_symbol): Initialize `function' to Qnil.
  * src/lread.c (init_obarray): Set `function' fields to Qnil.
  * src/eval.c (Fcommandp): Ignore Qunbound.
  (Fautoload, eval_sub, Fapply, Ffuncall, Fmacroexpand):
  * src/data.c (Ffset, Ffboundp, indirect_function, Findirect_function):
  Test NILP rather than Qunbound.
  (Ffmakunbound): Set to Qnil.
  (Fsymbol_function): Never signal an error.
  (Finteractive_form): Ignore Qunbound.
modified:
  etc/NEWS
  src/ChangeLog
  src/alloc.c
  src/data.c
  src/eval.c
  src/lisp.h
  src/lread.c

=== modified file 'etc/NEWS'
--- a/etc/NEWS  2012-11-20 19:30:37 +0000
+++ b/etc/NEWS  2012-11-20 20:06:17 +0000
@@ -52,6 +52,10 @@
 
 * Incompatible Lisp Changes in Emacs 24.4
 
+** nil and "unbound" are indistinguishable in symbol-function.
+`symbol-function' never signals `void-function' any more.
+`fboundp' returns non-nil if the symbol was `fset' to nil.
+
 ** `defadvice' does not honor the `freeze' flag and cannot advise
 special-forms any more.
 

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-11-20 11:41:57 +0000
+++ b/src/ChangeLog     2012-11-20 20:06:17 +0000
@@ -1,3 +1,16 @@
+2012-11-20  Stefan Monnier  <address@hidden>
+
+       Conflate Qnil and Qunbound for `symbol-function'.
+       * alloc.c (Fmake_symbol): Initialize `function' to Qnil.
+       * lread.c (init_obarray): Set `function' fields to Qnil.
+       * eval.c (Fcommandp): Ignore Qunbound.
+       (Fautoload, eval_sub, Fapply, Ffuncall, Fmacroexpand):
+       * data.c (Ffset, Ffboundp, indirect_function, Findirect_function):
+       Test NILP rather than Qunbound.
+       (Ffmakunbound): Set to Qnil.
+       (Fsymbol_function): Never signal an error.
+       (Finteractive_form): Ignore Qunbound.
+
 2012-11-20  Paul Eggert  <address@hidden>
 
        * eval.c (interactive_p): Remove no-longer-used decl.

=== modified file 'src/alloc.c'
--- a/src/alloc.c       2012-11-12 01:09:34 +0000
+++ b/src/alloc.c       2012-11-20 20:06:17 +0000
@@ -3212,7 +3212,7 @@
 
 DEFUN ("make-symbol", Fmake_symbol, Smake_symbol, 1, 1, 0,
        doc: /* Return a newly allocated uninterned symbol whose name is NAME.
-Its value and function definition are void, and its property list is nil.  */)
+Its value is void, and its function definition and property list are nil.  */)
   (Lisp_Object name)
 {
   register Lisp_Object val;
@@ -3249,7 +3249,7 @@
   set_symbol_plist (val, Qnil);
   p->redirect = SYMBOL_PLAINVAL;
   SET_SYMBOL_VAL (p, Qunbound);
-  set_symbol_function (val, Qunbound);
+  set_symbol_function (val, Qnil);
   set_symbol_next (val, NULL);
   p->gcmarkbit = 0;
   p->interned = SYMBOL_UNINTERNED;

=== modified file 'src/data.c'
--- a/src/data.c        2012-11-12 02:08:06 +0000
+++ b/src/data.c        2012-11-20 20:06:17 +0000
@@ -543,12 +543,13 @@
   return (EQ (valcontents, Qunbound) ? Qnil : Qt);
 }
 
+/* FIXME: Make it an alias for function-symbol!  */
 DEFUN ("fboundp", Ffboundp, Sfboundp, 1, 1, 0,
        doc: /* Return t if SYMBOL's function definition is not void.  */)
   (register Lisp_Object symbol)
 {
   CHECK_SYMBOL (symbol);
-  return EQ (XSYMBOL (symbol)->function, Qunbound) ? Qnil : Qt;
+  return NILP (XSYMBOL (symbol)->function) ? Qnil : Qt;
 }
 
 DEFUN ("makunbound", Fmakunbound, Smakunbound, 1, 1, 0,
@@ -564,14 +565,14 @@
 }
 
 DEFUN ("fmakunbound", Ffmakunbound, Sfmakunbound, 1, 1, 0,
-       doc: /* Make SYMBOL's function definition be void.
+       doc: /* Make SYMBOL's function definition be nil.
 Return SYMBOL.  */)
   (register Lisp_Object symbol)
 {
   CHECK_SYMBOL (symbol);
   if (NILP (symbol) || EQ (symbol, Qt))
     xsignal1 (Qsetting_constant, symbol);
-  set_symbol_function (symbol, Qunbound);
+  set_symbol_function (symbol, Qnil);
   return symbol;
 }
 
@@ -580,9 +581,7 @@
   (register Lisp_Object symbol)
 {
   CHECK_SYMBOL (symbol);
-  if (!EQ (XSYMBOL (symbol)->function, Qunbound))
     return XSYMBOL (symbol)->function;
-  xsignal1 (Qvoid_function, symbol);
 }
 
 DEFUN ("symbol-plist", Fsymbol_plist, Ssymbol_plist, 1, 1, 0,
@@ -613,7 +612,7 @@
 
   function = XSYMBOL (symbol)->function;
 
-  if (!NILP (Vautoload_queue) && !EQ (function, Qunbound))
+  if (!NILP (Vautoload_queue) && !NILP (function))
     Vautoload_queue = Fcons (Fcons (symbol, function), Vautoload_queue);
 
   if (AUTOLOADP (function))
@@ -714,7 +713,7 @@
 {
   Lisp_Object fun = indirect_function (cmd); /* Check cycles.  */
 
-  if (NILP (fun) || EQ (fun, Qunbound))
+  if (NILP (fun))
     return Qnil;
 
   /* Use an `interactive-form' property if present, analogous to the
@@ -2008,10 +2007,10 @@
 
   for (;;)
     {
-      if (!SYMBOLP (hare) || EQ (hare, Qunbound))
+      if (!SYMBOLP (hare) || NILP (hare))
        break;
       hare = XSYMBOL (hare)->function;
-      if (!SYMBOLP (hare) || EQ (hare, Qunbound))
+      if (!SYMBOLP (hare) || NILP (hare))
        break;
       hare = XSYMBOL (hare)->function;
 
@@ -2038,10 +2037,10 @@
 
   /* Optimize for no indirection.  */
   result = object;
-  if (SYMBOLP (result) && !EQ (result, Qunbound)
+  if (SYMBOLP (result) && !NILP (result)
       && (result = XSYMBOL (result)->function, SYMBOLP (result)))
     result = indirect_function (result);
-  if (!EQ (result, Qunbound))
+  if (!NILP (result))
     return result;
 
   if (NILP (noerror))

=== modified file 'src/eval.c'
--- a/src/eval.c        2012-11-20 08:32:19 +0000
+++ b/src/eval.c        2012-11-20 20:06:17 +0000
@@ -875,7 +875,7 @@
          if (NILP (tem))
            {
              def = XSYMBOL (sym)->function;
-             if (!EQ (def, Qunbound))
+             if (!NILP (def))
                continue;
            }
          break;
@@ -890,7 +890,7 @@
          GCPRO1 (form);
          def = Fautoload_do_load (def, sym, Qmacro);
          UNGCPRO;
-         if (EQ (def, Qunbound) || !CONSP (def))
+         if (!CONSP (def))
            /* Not defined or definition not suitable.  */
            break;
          if (!EQ (XCAR (def), Qmacro))
@@ -1715,12 +1715,12 @@
 
   fun = function;
 
-  fun = indirect_function (fun); /* Check cycles. */
-  if (NILP (fun) || EQ (fun, Qunbound))
+  fun = indirect_function (fun); /* Check cycles.  */
+  if (NILP (fun))
     return Qnil;
 
   /* Check an `interactive-form' property if present, analogous to the
-     function-documentation property. */
+     function-documentation property.  */
   fun = function;
   while (SYMBOLP (fun))
     {
@@ -1780,7 +1780,7 @@
   CHECK_STRING (file);
 
   /* If function is defined and not as an autoload, don't override.  */
-  if (!EQ (XSYMBOL (function)->function, Qunbound)
+  if (!NILP (XSYMBOL (function)->function)
       && !AUTOLOADP (XSYMBOL (function)->function))
     return Qnil;
 
@@ -1959,7 +1959,7 @@
 
   /* Optimize for no indirection.  */
   fun = original_fun;
-  if (SYMBOLP (fun) && !EQ (fun, Qunbound)
+  if (SYMBOLP (fun) && !NILP (fun)
       && (fun = XSYMBOL (fun)->function, SYMBOLP (fun)))
     fun = indirect_function (fun);
 
@@ -2081,7 +2081,7 @@
     val = apply_lambda (fun, original_args);
   else
     {
-      if (EQ (fun, Qunbound))
+      if (NILP (fun))
        xsignal1 (Qvoid_function, original_fun);
       if (!CONSP (fun))
        xsignal1 (Qinvalid_function, original_fun);
@@ -2155,10 +2155,10 @@
   numargs += nargs - 2;
 
   /* Optimize for no indirection.  */
-  if (SYMBOLP (fun) && !EQ (fun, Qunbound)
+  if (SYMBOLP (fun) && !NILP (fun)
       && (fun = XSYMBOL (fun)->function, SYMBOLP (fun)))
     fun = indirect_function (fun);
-  if (EQ (fun, Qunbound))
+  if (NILP (fun))
     {
       /* Let funcall get the error.  */
       fun = args[0];
@@ -2632,7 +2632,7 @@
 
   /* Optimize for no indirection.  */
   fun = original_fun;
-  if (SYMBOLP (fun) && !EQ (fun, Qunbound)
+  if (SYMBOLP (fun) && !NILP (fun)
       && (fun = XSYMBOL (fun)->function, SYMBOLP (fun)))
     fun = indirect_function (fun);
 
@@ -2720,7 +2720,7 @@
     val = funcall_lambda (fun, numargs, args + 1);
   else
     {
-      if (EQ (fun, Qunbound))
+      if (NILP (fun))
        xsignal1 (Qvoid_function, original_fun);
       if (!CONSP (fun))
        xsignal1 (Qinvalid_function, original_fun);

=== modified file 'src/lisp.h'
--- a/src/lisp.h        2012-11-14 04:55:41 +0000
+++ b/src/lisp.h        2012-11-20 20:06:17 +0000
@@ -1104,7 +1104,7 @@
     union Lisp_Fwd *fwd;
   } val;
 
-  /* Function value of the symbol or Qunbound if not fboundp.  */
+  /* Function value of the symbol or Qnil if not fboundp.  */
   Lisp_Object function;
 
   /* The symbol's property list.  */

=== modified file 'src/lread.c'
--- a/src/lread.c       2012-11-14 04:55:41 +0000
+++ b/src/lread.c       2012-11-20 20:06:17 +0000
@@ -3957,12 +3957,13 @@
   /* Fmake_symbol inits fields of new symbols with Qunbound and Qnil,
      so those two need to be fixed manually.  */
   SET_SYMBOL_VAL (XSYMBOL (Qunbound), Qunbound);
-  set_symbol_function (Qunbound, Qunbound);
+  set_symbol_function (Qunbound, Qnil);
   set_symbol_plist (Qunbound, Qnil);
   SET_SYMBOL_VAL (XSYMBOL (Qnil), Qnil);
   XSYMBOL (Qnil)->constant = 1;
   XSYMBOL (Qnil)->declared_special = 1;
   set_symbol_plist (Qnil, Qnil);
+  set_symbol_function (Qnil, Qnil);
 
   Qt = intern_c_string ("t");
   SET_SYMBOL_VAL (XSYMBOL (Qt), Qt);