Add d8 functionality for switching between realms (a.k.a. contexts), 2nd try

The only difference to the previous implementation (https://codereview.chromium.org/14295011/) is in patch set 2.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/14404005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14373 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8.h

@@ -298,6 +298,19 @@ class Shell : public i::AllStatic {
 #endif  // ENABLE_DEBUGGER_SUPPORT
 #endif  // V8_SHARED
 
+  static Handle<Value> RealmCurrent(const Arguments& args);
+  static Handle<Value> RealmOwner(const Arguments& args);
+  static Handle<Value> RealmGlobal(const Arguments& args);
+  static Handle<Value> RealmCreate(const Arguments& args);
+  static Handle<Value> RealmDispose(const Arguments& args);
+  static Handle<Value> RealmSwitch(const Arguments& args);
+  static Handle<Value> RealmEval(const Arguments& args);
+  static Handle<Value> RealmSharedGet(Local<String> property,
+                                      const AccessorInfo& info);
+  static void RealmSharedSet(Local<String> property,
+                             Local<Value> value,
+                             const AccessorInfo& info);
+
   static Handle<Value> Print(const Arguments& args);
   static Handle<Value> Write(const Arguments& args);
   static Handle<Value> Quit(const Arguments& args);

src/debug.cc

@@ -612,7 +612,6 @@ void ScriptCache::Add(Handle<Script> script) {
     ASSERT(*script == *reinterpret_cast<Script**>(entry->value));
     return;
   }
-
   // Globalize the script object, make it weak and use the location of the
   // global handle as the value in the hash map.
   Handle<Script> script_ =

src/objects.h

@@ -8578,7 +8578,7 @@ class JSWeakMap: public JSObject {
 
 class JSArrayBuffer: public JSObject {
  public:
-  // [backing_store]: backing memory for thsi array
+  // [backing_store]: backing memory for this array
   DECL_ACCESSORS(backing_store, void)
 
   // [byte_length]: length in bytes

test/mjsunit/bugs/bug-proto.js

+// Copyright 2013 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 realmA = Realm.current();
+var realmB = Realm.create();
+assertEquals(0, realmA);
+assertEquals(1, realmB);
+
+// The global objects match the realms' this binding.
+assertSame(this, Realm.global(realmA));
+assertSame(Realm.eval(realmB, "this"), Realm.global(realmB));
+assertFalse(this === Realm.global(realmB));
+
+// The global object is not accessible cross-realm.
+var x = 3;
+Realm.shared = this;
+assertThrows("Realm.eval(realmB, 'x')");
+assertSame(undefined, Realm.eval(realmB, "this.x"));
+assertSame(undefined, Realm.eval(realmB, "Realm.shared.x"));
+
+Realm.eval(realmB, "Realm.global(0).y = 1");
+assertThrows("y");
+assertSame(undefined, this.y);
+
+// Can get or set other objects' properties cross-realm.
+var p = {a: 1};
+var o = {__proto__: p, b: 2};
+Realm.shared = o;
+assertSame(1, Realm.eval(realmB, "Realm.shared.a"));
+assertSame(2, Realm.eval(realmB, "Realm.shared.b"));
+
+// Cannot get or set a prototype cross-realm.
+assertSame(undefined, Realm.eval(realmB, "Realm.shared.__proto__"));
+
+Realm.eval(realmB, "Realm.shared.__proto__ = {c: 3}");
+assertSame(1, o.a);
+assertSame(undefined, o.c);
+