Merged: Squashed multiple commits.

Merged: Add test for making private symbols non-enumerable
Revision: 942604d

Merged: Make private symbols non-enumerable
Revision: 135b9f9

BUG=chromium:664411,chromium:664411
LOG=N
NOTRY=true
NOPRESUBMIT=true
NOTREECHECKS=true
R=cbruni@chromium.org

Review URL: https://codereview.chromium.org/2498973002 .

Cr-Commit-Position: refs/branch-heads/5.5@{v8#40}
Cr-Branched-From: 3cbd583-refs/heads/5.5.372@{#1}
Cr-Branched-From: b3c8b0c-refs/heads/master@{#40015}

src/lookup.cc

@@ -307,6 +307,11 @@ void LookupIterator::PrepareTransitionToDataProperty(
     PropertyAttributes attributes, Object::StoreFromKeyed store_mode) {
   DCHECK(receiver.is_identical_to(GetStoreTarget()));
   if (state_ == TRANSITION) return;
+
+  if (!IsElement() && name()->IsPrivate()) {
+    attributes = static_cast<PropertyAttributes>(attributes | DONT_ENUM);
+  }
+
   DCHECK(state_ != LookupIterator::ACCESSOR ||
          (GetAccessors()->IsAccessorInfo() &&
           AccessorInfo::cast(*GetAccessors())->is_special_data_property()));
@@ -441,6 +446,9 @@ void LookupIterator::TransitionToAccessorProperty(
   // handled via a trap. Adding properties to primitive values is not
   // observable.
   Handle<JSObject> receiver = GetStoreTarget();
+  if (!IsElement() && name()->IsPrivate()) {
+    attributes = static_cast<PropertyAttributes>(attributes | DONT_ENUM);
+  }
 
   if (!IsElement() && !receiver->map()->is_dictionary_map()) {
     Handle<Map> old_map(receiver->map(), isolate_);

src/property.h

@@ -36,6 +36,7 @@ class Descriptor BASE_EMBEDDED {
 
   void Init(Handle<Name> key, Handle<Object> value, PropertyDetails details) {
     DCHECK(key->IsUniqueName());
+    DCHECK_IMPLIES(key->IsPrivate(), !details.IsEnumerable());
     key_ = key;
     value_ = value;
     details_ = details;
@@ -44,6 +45,7 @@ class Descriptor BASE_EMBEDDED {
   Descriptor(Handle<Name> key, Handle<Object> value, PropertyDetails details)
       : key_(key), value_(value), details_(details) {
     DCHECK(key->IsUniqueName());
+    DCHECK_IMPLIES(key->IsPrivate(), !details_.IsEnumerable());
   }
 
   Descriptor(Handle<Name> key, Handle<Object> value,
@@ -53,6 +55,7 @@ class Descriptor BASE_EMBEDDED {
         value_(value),
         details_(attributes, type, representation, field_index) {
     DCHECK(key->IsUniqueName());
+    DCHECK_IMPLIES(key->IsPrivate(), !details_.IsEnumerable());
   }
 
   friend class DescriptorArray;

test/mjsunit/harmony/private.js

@@ -278,8 +278,8 @@ function TestKeyDescriptor(obj) {
     assertEquals(i|0, desc.value)
     assertTrue(desc.configurable)
     assertEquals(i % 2 == 0, desc.writable)
-    assertEquals(i % 2 == 0, desc.enumerable)
-    assertEquals(i % 2 == 0,
+    assertEquals(false, desc.enumerable)
+    assertEquals(false,
         Object.prototype.propertyIsEnumerable.call(obj, symbols[i]))
   }
 }

test/mjsunit/regress/regress-private-enumerable.js

@@ -0,0 +1,8 @@
+// Copyright 2016 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.
+
+class A {}
+class B {}
+Object.assign(B, A);
+assertEquals("class B {}", B.toString());