Array.prototype.{every, filter, find, findIndex, forEach, map, some}: Use fresh primitive wrapper f…

src/array.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 "use strict";
 
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 1108 matching lines @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = ToUint32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
-  } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
-    receiver = ToObject(receiver);
   }
 
   var result = new $Array();
   var accumulator = new InternalArray();
   var accumulator_length = 0;
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&

[arv (Not doing code reviews), 2014/09/12 16:29:17]

Can this test be moved out of the loop?

[Diego Pino, 2014/09/16 10:45:46]

In strict mode, GetDefaultReceiver can return 'undefined'. ToObject throws an
exception if the argument is undefined, so I need to avoid that case.

[wingo, 2014/09/16 12:04:04]

I think Erik was referring to the test, not the body of the test.

e.g.

var needs_wrapper = ...;

for () {
  var new_receiver = needs_wrapper ? ToObject(receiver) : receiver;
  ...
}

+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(f);
-      if (%_CallFunction(receiver, element, i, array, f)) {
+      if (%_CallFunction(new_receiver, element, i, array, f)) {
         accumulator[accumulator_length++] = element;
       }
     }
   }
   %MoveArrayContents(accumulator, result);
   return result;
 }
 
 
 function ArrayForEach(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.forEach");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
-  } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
-    receiver = ToObject(receiver);
   }
 
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&

[arv (Not doing code reviews), 2014/09/12 16:29:17]

Maybe we can introduce a helper function/macro for this?

SHOULD_CREATE_WRAPPER(receiver, f)

[Diego Pino, 2014/09/16 10:45:46]

Acknowledged.

+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(f);
-      %_CallFunction(receiver, element, i, array, f);
+      %_CallFunction(new_receiver, element, i, array, f);
     }
   }
 }
 
 
 // Executes the function once for each element present in the
 // array until it finds one where callback returns true.
 function ArraySome(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.some");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
-  } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
-    receiver = ToObject(receiver);
   }
 
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&
+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(f);
-      if (%_CallFunction(receiver, element, i, array, f)) return true;
+      if (%_CallFunction(new_receiver, element, i, array, f)) return true;
     }
   }
   return false;
 }
 
 
 function ArrayEvery(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.every");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
-  } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
-    receiver = ToObject(receiver);
   }
 
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&
+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(f);
-      if (!%_CallFunction(receiver, element, i, array, f)) return false;
+      if (!%_CallFunction(new_receiver, element, i, array, f)) return false;
     }
   }
   return true;
 }
 
 function ArrayMap(f, receiver) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.map");
 
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = ToObject(this);
   var length = TO_UINT32(array.length);
 
   if (!IS_SPEC_FUNCTION(f)) {
     throw MakeTypeError('called_non_callable', [ f ]);
   }
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
-  } else if (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
-    receiver = ToObject(receiver);
   }
 
   var result = new $Array();
   var accumulator = new InternalArray(length);
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&
+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(f);
-      accumulator[i] = %_CallFunction(receiver, element, i, array, f);
+      accumulator[i] = %_CallFunction(new_receiver, element, i, array, f);
     }
   }
   %MoveArrayContents(accumulator, result);
   return result;
 }
 
 
 function ArrayIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.indexOf");
 
@@ skipping 126 matching lines @@
       }
     }
     throw MakeTypeError('reduce_no_initial', []);
   }
 
   var receiver = %GetDefaultReceiver(callback);
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(callback);
   for (; i < length; i++) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&
+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(callback);
-      current = %_CallFunction(receiver, current, element, i, array, callback);
+      current = %_CallFunction(new_receiver, current, element, i, array, callback);
     }
   }
   return current;
 }
 
 function ArrayReduceRight(callback, current) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduceRight");
 
   // Pull out the length so that side effects are visible before the
   // callback function is checked.
@@ skipping 14 matching lines @@
       }
     }
     throw MakeTypeError('reduce_no_initial', []);
   }
 
   var receiver = %GetDefaultReceiver(callback);
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(callback);
   for (; i >= 0; i--) {
     if (i in array) {
       var element = array[i];
+      var new_receiver = receiver;
+      if (!IS_NULL_OR_UNDEFINED(receiver) &&
+          !IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(f)) {
+        new_receiver = ToObject(receiver);
+      }
       // Prepare break slots for debugger step in.
       if (stepping) %DebugPrepareStepInIfStepping(callback);
-      current = %_CallFunction(receiver, current, element, i, array, callback);
+      current = %_CallFunction(new_receiver, current, element, i, array, callback);
     }
   }
   return current;
 }
 
 // ES5, 15.4.3.2
 function ArrayIsArray(obj) {
   return IS_ARRAY(obj);
 }
 
@@ skipping 82 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();