[strong] Implement per-object restrictions behaviour of property freezing

src/v8natives.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.
 
 var $delete;
 var $functionSourceString;
 var $getIterator;
 var $getMethod;
 var $globalEval;
 var $installConstants;
@@ skipping 787 matching lines @@
         // Step 9a
         if (IsDataDescriptor(current) != IsDataDescriptor(desc)) {
           if (should_throw) {
             throw MakeTypeError(kRedefineDisallowed, p);
           } else {
             return false;
           }
         }
         // Step 10a
         if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
-          if (!current.isWritable() && desc.isWritable()) {
-            if (should_throw) {
-              throw MakeTypeError(kRedefineDisallowed, p);
-            } else {
-              return false;
+          var currentIsWritable = current.isWritable();
+          if (currentIsWritable != desc.isWritable()) {
+            if (!currentIsWritable) {

[rossberg, 2015/05/22 13:10:28]

Nit:  if (!currentIsWritable || IS_STRONG(obj))  here

[conradw, 2015/05/22 14:07:08]

Done. Silly to miss this.

+              if (should_throw) {
+                throw MakeTypeError(kRedefineDisallowed, p);

[rossberg, 2015/05/22 13:10:28]

...and then  throw currentIsWritable ? MakeTypeError(...) : MakeTypeError(...) 
here

[conradw, 2015/05/22 14:07:08]

Done.

+              } else {
+                return false;
+              }
+            }
+            if (IS_STRONG(obj)) {

[rossberg, 2015/05/22 13:10:28]

...and eliminate this duplication

[conradw, 2015/05/22 14:07:08]

Done.

+              if (should_throw) {
+                throw MakeTypeError(kStrongRedefineDisallowed, p, obj);
+              } else {
+                return false;
+              }
             }
           }
-          if (!current.isWritable() && desc.hasValue() &&
+          if (!currentIsWritable && desc.hasValue() &&
               !$sameValue(desc.getValue(), current.getValue())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);
             } else {
               return false;
             }
           }
         }
         // Step 11
         if (IsAccessorDescriptor(desc) && IsAccessorDescriptor(current)) {
@@ skipping 1144 matching lines @@
 $objectLookupSetter = ObjectLookupSetter;
 $objectToString = ObjectToString;
 $overrideFunction = OverrideFunction;
 $ownPropertyKeys = OwnPropertyKeys;
 $setFunctionName = SetFunctionName;
 $setUpLockedPrototype = SetUpLockedPrototype;
 $toCompletePropertyDescriptor = ToCompletePropertyDescriptor;
 $toNameArray = ToNameArray;
 
 })