Array.prototype.sort: Unchecked calls to hasOwnProperty and push and sort

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 846 matching lines @@
       }
       a[j + 1] = element;
     }
   };
 
   var GetThirdIndex = function(a, from, to) {
     var t_array = [];
     // Use both 'from' and 'to' to determine the pivot candidates.
     var increment = 200 + ((to - from) & 15);
     for (var i = from + 1; i < to - 1; i += increment) {
-      t_array.push([i, a[i]]);
+      ArrayPush.call(t_array, [i, a[i]]);

[arv (Not doing code reviews), 2014/09/10 15:47:39]

%_CallFunction(t_array, [i, a[i]], ArrayPush)

But why are we using push here? Can't we just do?

t_array[nextIndex] = [i, a[i]]

     }
-    t_array.sort(function(a, b) {
-        return %_CallFunction(receiver, a[1], b[1], comparefn) } );
+    ArraySort.call(t_array, function(a, b) {

[arv (Not doing code reviews), 2014/09/10 15:47:39]

%_CallFunction

+        return %_CallFunction(receiver, a[1], b[1], comparefn);
+    });
     var third_index = t_array[t_array.length >> 1][0];
     return third_index;
   }
 
   var QuickSort = function QuickSort(a, from, to) {
     var third_index = 0;
     while (true) {
       // Insertion sort is faster for short arrays.
       if (to - from <= 10) {
         InsertionSort(a, from, to);
@@ skipping 74 matching lines @@
         QuickSort(a, from, low_end);
         from = high_start;
       }
     }
   };
 
   // Copy elements in the range 0..length from obj's prototype chain
   // to obj itself, if obj has holes. Return one more than the maximal index
   // of a prototype property.
   var CopyFromPrototype = function CopyFromPrototype(obj, length) {
+    var hasOwnProperty = $Object.prototype.hasOwnProperty;

[arv (Not doing code reviews), 2014/09/10 15:47:39]

Either use %HasOwnProperty or ObjectHasOwnProperty. The benefit of the second
one is that it will also work with Proxies but I'm not sure we need to handle
those here?

     var max = 0;
     for (var proto = %GetPrototype(obj); proto; proto = %GetPrototype(proto)) {
       var indices = %GetArrayKeys(proto, length);
       if (IS_NUMBER(indices)) {
         // It's an interval.
         var proto_length = indices;
         for (var i = 0; i < proto_length; i++) {
-          if (!obj.hasOwnProperty(i) && proto.hasOwnProperty(i)) {
+          if (!hasOwnProperty.call(obj, i) && hasOwnProperty.call(proto, i)) {

[arv (Not doing code reviews), 2014/09/10 15:47:39]

call could have been replaced too :'(

Use

%_CallFunction(obj, i, ObjectHasOwnProperty)

             obj[i] = proto[i];
             if (i >= max) { max = i + 1; }
           }
         }
       } else {
         for (var i = 0; i < indices.length; i++) {
           var index = indices[i];
           if (!IS_UNDEFINED(index) &&
-              !obj.hasOwnProperty(index) && proto.hasOwnProperty(index)) {
+              !hasOwnProperty.call(obj, index) && hasOwnProperty.call(proto, index)) {
             obj[index] = proto[index];
             if (index >= max) { max = index + 1; }
           }
         }
       }
     }
     return max;
   };
 
   // Set a value of "undefined" on all indices in the range from..to
   // where a prototype of obj has an element. I.e., shadow all prototype
   // elements in that range.
   var ShadowPrototypeElements = function(obj, from, to) {
+    var hasOwnProperty = $Object.prototype.hasOwnProperty;
     for (var proto = %GetPrototype(obj); proto; proto = %GetPrototype(proto)) {
       var indices = %GetArrayKeys(proto, to);
       if (IS_NUMBER(indices)) {
         // It's an interval.
         var proto_length = indices;
         for (var i = from; i < proto_length; i++) {
-          if (proto.hasOwnProperty(i)) {
+          if (hasOwnProperty.call(proto, i)) {
             obj[i] = UNDEFINED;
           }
         }
       } else {
         for (var i = 0; i < indices.length; i++) {
           var index = indices[i];
           if (!IS_UNDEFINED(index) && from <= index &&
-              proto.hasOwnProperty(index)) {
+              hasOwnProperty.call(proto, index)) {
             obj[index] = UNDEFINED;
           }
         }
       }
     }
   };
 
   var SafeRemoveArrayHoles = function SafeRemoveArrayHoles(obj) {
     // Copy defined elements from the end to fill in all holes and undefineds
     // in the beginning of the array.  Write undefineds and holes at the end
     // after loop is finished.
     var first_undefined = 0;
     var last_defined = length - 1;
     var num_holes = 0;
     while (first_undefined < last_defined) {
       // Find first undefined element.
       while (first_undefined < last_defined &&
              !IS_UNDEFINED(obj[first_undefined])) {
         first_undefined++;
       }
       // Maintain the invariant num_holes = the number of holes in the original
       // array with indices <= first_undefined or > last_defined.
-      if (!obj.hasOwnProperty(first_undefined)) {
+      if (!hasOwnProperty.call(obj, first_undefined)) {
         num_holes++;
       }
 
       // Find last defined element.
       while (first_undefined < last_defined &&
              IS_UNDEFINED(obj[last_defined])) {
-        if (!obj.hasOwnProperty(last_defined)) {
+        if (!$Object.prototype.hasOwnProperty.call(obj, last_defined)) {
           num_holes++;
         }
         last_defined--;
       }
       if (first_undefined < last_defined) {
         // Fill in hole or undefined.
         obj[first_undefined] = obj[last_defined];
         obj[last_defined] = UNDEFINED;
       }
     }
@@ skipping 496 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();