[proxies] Implement [[PreventExtensions]] and [[IsExtensible]].

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 9502 matching lines @@
   // [hash]: The hash code property (undefined if not initialized yet).
   DECL_ACCESSORS(hash, Object)
 
   inline bool has_handler();
 
   DECLARE_CAST(JSProxy)
 
   // ES6 9.5.1
   static MaybeHandle<Object> GetPrototype(Handle<JSProxy> receiver);
 
+  static bool IsRevoked(Handle<JSProxy> proxy);
+
+  MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSProxy> proxy);

[Camillo Bruni, 2015/11/17 08:57:17]

can you put the ES6 section? 9.5.?

+
   // ES6 9.5.5
   static bool GetOwnPropertyDescriptor(LookupIterator* it,
                                        PropertyDescriptor* desc);
 
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
       Handle<JSProxy> proxy,
       Handle<Object> receiver,
       Handle<Name> name);
 
+  // ES6 9.5.4 [[PreventExtensions]] (when passed DONT_THROW)
+  MUST_USE_RESULT static Maybe<bool> PreventExtensions(
+      Handle<JSProxy> proxy, ShouldThrow should_throw);
+
   // If the handler defines an accessor property with a setter, invoke it.
   // If it defines an accessor property without a setter, or a data property
   // that is read-only, fail.  In all these cases set '*done' to true.
   // Otherwise set it to false, in which case the return value is not
   // meaningful.
   MUST_USE_RESULT
   static Maybe<bool> SetPropertyViaPrototypesWithHandler(
       Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
       Handle<Object> value, ShouldThrow should_throw, bool* done);
 
@@ skipping 19 matching lines @@
 
   typedef FixedBodyDescriptor<kTargetOffset, kSize, kSize> BodyDescriptor;
 
   MUST_USE_RESULT Object* GetIdentityHash();
 
   static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
 
  private:
   friend class JSReceiver;
 
+  MUST_USE_RESULT static MaybeHandle<Object> GetTrap(Handle<JSProxy> proxy,
+                                                     Handle<String> trap);
+
   // Invoke a trap by name. If the trap does not exist on this's handler,
   // but derived_trap is non-NULL, invoke that instead.  May cause GC.
   MUST_USE_RESULT static MaybeHandle<Object> CallTrap(
       Handle<JSProxy> proxy, const char* name, Handle<Object> derived_trap,
       int argc, Handle<Object> args[]);
 
   MUST_USE_RESULT static Maybe<bool> HasPropertyWithHandler(
       Handle<JSProxy> proxy, Handle<Name> name);
 
   MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithHandler(
@@ skipping 1125 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_