Reviewers: Mads Ager, Rico,
Message:
8.6.2 Object Internal Methods
...
In addition, if [[Extensible]] is false the value of the [[Class]] and
[[Prototype]] internal properties of the object may not be modified. Once
the
value of an [[Extensible]] internal property has been set to false it may
not be
subsequently changed to true.
NOTE This specification defines no ECMAScript language operators or built-in
functions that permit a program to modify an object’s [[Class]] or
[[Prototype]]
internal properties or to change the value of [[Extensible]] from false to
true.
Implementation specific extensions that modify [[Class]], [[Prototype]] or
[[Extensible]] must not violate the invariants defined in the preceding
paragraph.
Description:
Bug 1309 non-extensible objects have immutable __Proto__
BUG=
TEST=
Please review this at http://codereview.chromium.org/6800014/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/messages.js
M src/objects.cc
A test/mjsunit/regress/regress-1309.js
Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index
3eb056f33248314292d6cb947a05a8f460898b51..e657fc05fcb93038c088b72045f47fe163b046ad
100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -190,6 +190,7 @@ function FormatMessage(message) {
property_desc_object: ["Property description must be an
object: ", "%0"],
redefine_disallowed: ["Cannot redefine property: ", "%0"],
define_disallowed: ["Cannot define property, object is
not extensible: ", "%0"],
+ non_extensible_proto: ["%0", " is not extensible"],
// RangeError
invalid_array_length: ["Invalid array length"],
stack_overflow: ["Maximum call stack size exceeded"],
Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index
9a5357a338db84f2a643c5980d3dc3dd028ca031..47ba64dce0e49c2003525403a3ecbb8b9434c7d7
100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -6866,6 +6866,22 @@ MaybeObject* JSObject::SetPrototype(Object* value,
// SpiderMonkey behaves this way.
if (!value->IsJSObject() && !value->IsNull()) return value;
+ // From 8.6.2 Object Internal Methods
+ // ...
+ // In addition, if [[Extensible]] is false the value of the [[Class]] and
+ // [[Prototype]] internal properties of the object may not be modified.
+ // ...
+ // Implementation specific extensions that modify [[Class]],
[[Prototype]]
+ // or [[Extensible]] must not violate the invariants defined in the
preceding
+ // paragraph.
+ if (!this->map()->is_extensible()) {
+ HandleScope scope;
+ Handle<Object> handle(this, heap->isolate());
+ return heap->isolate()->Throw(
+ *FACTORY->NewTypeError("non_extensible_proto",
+ HandleVector<Object>(&handle, 1)));
+ }
+
// Before we can set the prototype we need to be sure
// prototype cycles are prevented.
// It is sufficient to validate that the receiver is not in the new
prototype
Index: test/mjsunit/regress/regress-1309.js
diff --git a/test/mjsunit/regress/regress-1309.js
b/test/mjsunit/regress/regress-1309.js
new file mode 100644
index
0000000000000000000000000000000000000000..d217f7b9d2074b1d7192a65199a784f89691906c
--- /dev/null
+++ b/test/mjsunit/regress/regress-1309.js
@@ -0,0 +1,30 @@
+// Copyright 2010 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
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+var o = Object.preventExtensions({});
+assertThrows("o.__proto__ = {}");
--
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