(Vnonascii_translation_table): Name changed from

[gnu-emacs] / src / data.c

diff --git a/src/data.c b/src/data.c
index c9eaee7a9b253489ea02508600cd9f2cea0882c5..eb04f5a39aac42f5dccbb6bc271e4187a46be2ca 100644 (file)
--- a/src/data.c
+++ b/src/data.c
@@ -68,6 +68,10 @@ Boston, MA 02111-1307, USA.  */
 extern double atof ();
 #endif /* !atof */
 
+/* Nonzero means it is an error to set a symbol whose name starts with
+   colon.  */
+int keyword_symbols_constant_flag;
+
 Lisp_Object Qnil, Qt, Qquote, Qlambda, Qsubr, Qunbound;
 Lisp_Object Qerror_conditions, Qerror_message, Qtop_level;
 Lisp_Object Qerror, Qquit, Qwrong_type_argument, Qargs_out_of_range;
@@ -132,6 +136,7 @@ wrong_type_argument (predicate, value)
   return value;
 }
 
+void
 pure_write_error ()
 {
   error ("Attempt to modify read-only object");
@@ -611,7 +616,10 @@ DEFUN ("makunbound", Fmakunbound, Smakunbound, 1, 1, 0, "Make SYMBOL's value be
      register Lisp_Object symbol;
 {
   CHECK_SYMBOL (symbol, 0);
-  if (NILP (symbol) || EQ (symbol, Qt))
+  if (NILP (symbol) || EQ (symbol, Qt)
+      || (XSYMBOL (symbol)->name->data[0] == ':'
+         && EQ (XSYMBOL (symbol)->obarray, initial_obarray)
+         && keyword_symbols_constant_flag))
     return Fsignal (Qsetting_constant, Fcons (symbol, Qnil));
   Fset (symbol, Qunbound);
   return symbol;
@@ -960,7 +968,10 @@ set_internal (symbol, newval, bindflag)
   register Lisp_Object valcontents, tem1, current_alist_element;
 
   CHECK_SYMBOL (symbol, 0);
-  if (NILP (symbol) || EQ (symbol, Qt))
+  if (NILP (symbol) || EQ (symbol, Qt)
+      || (XSYMBOL (symbol)->name->data[0] == ':'
+         && EQ (XSYMBOL (symbol)->obarray, initial_obarray)
+         && keyword_symbols_constant_flag && ! EQ (newval, symbol)))
     return Fsignal (Qsetting_constant, Fcons (symbol, Qnil));
   valcontents = XSYMBOL (symbol)->value;
 
@@ -2470,8 +2481,12 @@ In this case, the sign bit is duplicated.")
   CHECK_NUMBER (value, 0);
   CHECK_NUMBER (count, 1);
 
-  if (XINT (count) > 0)
+  if (XINT (count) >= BITS_PER_EMACS_INT)
+    XSETINT (val, 0);
+  else if (XINT (count) > 0)
     XSETINT (val, XINT (value) << XFASTINT (count));
+  else if (XINT (count) <= -BITS_PER_EMACS_INT)
+    XSETINT (val, XINT (value) < 0 ? -1 : 0);
   else
     XSETINT (val, XINT (value) >> -XINT (count));
   return val;
@@ -2489,8 +2504,12 @@ In this case,  zeros are shifted in on the left.")
   CHECK_NUMBER (value, 0);
   CHECK_NUMBER (count, 1);
 
-  if (XINT (count) > 0)
+  if (XINT (count) >= BITS_PER_EMACS_INT)
+    XSETINT (val, 0);
+  else if (XINT (count) > 0)
     XSETINT (val, (EMACS_UINT) XUINT (value) << XFASTINT (count));
+  else if (XINT (count) <= -BITS_PER_EMACS_INT)
+    XSETINT (val, 0);
   else
     XSETINT (val, (EMACS_UINT) XUINT (value) >> -XINT (count));
   return val;
@@ -2833,6 +2852,11 @@ syms_of_data ()
   staticpro (&Qchar_table);
   staticpro (&Qbool_vector);
 
+  DEFVAR_BOOL ("keyword-symbols-constant-flag", &keyword_symbols_constant_flag,
+    "Non-nil means it is an error to set a keyword symbol.\n\
+A keyword symbol is a symbol whose name starts with a colon (`:').");
+  keyword_symbols_constant_flag = 1;
+
   defsubr (&Seq);
   defsubr (&Snull);
   defsubr (&Stype_of);
@@ -2944,6 +2968,7 @@ arith_error (signo)
   Fsignal (Qarith_error, Qnil);
 }
 
+void
 init_data ()
 {
   /* Don't do this if just dumping out.