Version 3.1.3....

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1135 matching lines @@
 }
 
 
 // ES5 15.3.4.5
 function FunctionBind(this_arg) { // Length is 1.
   if (!IS_FUNCTION(this)) {
       throw new $TypeError('Bind must be called on a function');
   }
   // this_arg is not an argument that should be bound.
   var argc_bound = (%_ArgumentsLength() || 1) - 1;
-  if (argc_bound > 0) {
+  var fn = this;
+  if (argc_bound == 0) {
+    var result = function() {
+      if (%_IsConstructCall()) {
+        // %NewObjectFromBound implicitly uses arguments passed to this
+        // function. We do not pass the arguments object explicitly to avoid
+        // materializing it and guarantee that this function will be optimized.
+        return %NewObjectFromBound(fn, null);
+      }
+
+      return fn.apply(this_arg, arguments);
+    };
+  } else {
     var bound_args = new $Array(argc_bound);
     for(var i = 0; i < argc_bound; i++) {
       bound_args[i] = %_Arguments(i+1);
     }
+
+    var result = function() {
+      // If this is a construct call we use a special runtime method
+      // to generate the actual object using the bound function.
+      if (%_IsConstructCall()) {
+        // %NewObjectFromBound implicitly uses arguments passed to this
+        // function. We do not pass the arguments object explicitly to avoid
+        // materializing it and guarantee that this function will be optimized.
+        return %NewObjectFromBound(fn, bound_args);
+      }
+
+      // Combine the args we got from the bind call with the args
+      // given as argument to the invocation.
+      var argc = %_ArgumentsLength();
+      var args = new $Array(argc + argc_bound);
+      // Add bound arguments.
+      for (var i = 0; i < argc_bound; i++) {
+        args[i] = bound_args[i];
+      }
+      // Add arguments from call.
+      for (var i = 0; i < argc; i++) {
+        args[argc_bound + i] = %_Arguments(i);
+      }
+      return fn.apply(this_arg, args);
+    };
   }
-  var fn = this;
-  var result = function() {
-    // Combine the args we got from the bind call with the args
-    // given as argument to the invocation.
-    var argc = %_ArgumentsLength();
-    var args = new $Array(argc + argc_bound);
-    // Add bound arguments.
-    for (var i = 0; i < argc_bound; i++) {
-      args[i] = bound_args[i];
-    }
-    // Add arguments from call.
-    for (var i = 0; i < argc; i++) {
-      args[argc_bound + i] = %_Arguments(i);
-    }
-    // If this is a construct call we use a special runtime method
-    // to generate the actual object using the bound function.
-    if (%_IsConstructCall()) {
-      return %NewObjectFromBound(fn, args);
-    }
-    return fn.apply(this_arg, args);
-  };
 
   // We already have caller and arguments properties on functions,
   // which are non-configurable. It therefore makes no sence to
   // try to redefine these as defined by the spec. The spec says
   // that bind should make these throw a TypeError if get or set
   // is called and make them non-enumerable and non-configurable.
   // To be consistent with our normal functions we leave this as it is.
 
   // Set the correct length.
   var length = (this.length - argc_bound) > 0 ? this.length - argc_bound : 0;
@@ skipping 30 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();