Implement implicit instance checks for API accessors.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index d31ef5405cfaf5c0fb7bbd419b73c50b715ca3a9..55b4e22256278f33116e9426782a30bf25b2ae5f 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -2289,7 +2289,8 @@ class V8EXPORT FunctionTemplate : public Template {
                                    AccessorSetter setter,
                                    Handle<Value> data,
                                    AccessControl settings,
-                                   PropertyAttribute attributes);
+                                   PropertyAttribute attributes,
+                                   Handle<FunctionTemplate> constructor);
   void SetNamedInstancePropertyHandler(NamedPropertyGetter getter,
                                        NamedPropertySetter setter,
                                        NamedPropertyQuery query,
@@ -2347,13 +2348,19 @@ class V8EXPORT ObjectTemplate : public Template {
    *   cross-context access.
    * \param attribute The attributes of the property for which an accessor
    *   is added.
+   * \param constructor The constructor used to perform an implicit instance
+   *   check against. If the receiver is incompatible (i.e. is not an instance
+   *   of the constructor as defined by FunctionTemplate::HasInstance()), an
+   *   implicit TypeError is thrown and no callback is invoked.
    */
   void SetAccessor(Handle<String> name,
                    AccessorGetter getter,
                    AccessorSetter setter = 0,
                    Handle<Value> data = Handle<Value>(),
                    AccessControl settings = DEFAULT,
-                   PropertyAttribute attribute = None);
+                   PropertyAttribute attribute = None,
+                   Handle<FunctionTemplate> constructor =

[Michael Starzinger, 2012/06/01 13:19:43]

As discussed offline, we might want to wrap this FunctionTemplate into some
AccessorSignature, because we already have a similar concept for invocation
callbacks.

[Michael Starzinger, 2012/06/04 11:34:34]

Done.

+                       Handle<FunctionTemplate>());
 
   /**
    * Sets a named property handler on the object template.