[api] Add interceptor for defineProperty().

src/objects.cc

 // Copyright 2015 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 1659 matching lines @@
     v8::GenericNamedPropertySetterCallback setter =
         v8::ToCData<v8::GenericNamedPropertySetterCallback>(
             interceptor->setter());
     result = !args.Call(setter, name, value).is_null();
   }
 
   RETURN_VALUE_IF_SCHEDULED_EXCEPTION(it->isolate(), Nothing<bool>());
   return Just(result);
 }
 
+Maybe<bool> DefinePropertyWithInterceptorInternal(
+    LookupIterator* it, Handle<InterceptorInfo> interceptor,
+    Object::ShouldThrow should_throw, PropertyDescriptor& desc) {
+  Isolate* isolate = it->isolate();
+  // Make sure that the top context does not change when doing callbacks or
+  // interceptor calls.
+  AssertNoContextChange ncc(isolate);
+
+  if (interceptor->definer()->IsUndefined(isolate)) return Just(false);
+
+  Handle<JSObject> holder = it->GetHolder<JSObject>();
+  bool result;
+  Handle<Object> receiver = it->GetReceiver();
+  if (!receiver->IsJSReceiver()) {
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, receiver,

[jochen (gone - plz use gerrit), 2016/08/26 18:18:46]

btw, is it a problem for your usecase that our interceptors are all in sloppy
mode, ie, we'll always box numbers etc?

[Franzi, 2016/09/01 06:38:18]

So far, nobody has complained about it :) 

+                                     Object::ConvertReceiver(isolate, receiver),
+                                     Nothing<bool>());
+  }
+  PropertyCallbackArguments args(isolate, interceptor->data(), *receiver,
+                                 *holder, should_throw);
+
+  std::unique_ptr<v8::PropertyDescriptor> propDescriptor(

[jochen (gone - plz use gerrit), 2016/08/26 18:18:46]

nit. property_descriptor

[Franzi, 2016/09/01 06:38:18]

Done.

+      new v8::PropertyDescriptor());
+  if (PropertyDescriptor::IsAccessorDescriptor(&desc)) {
+    Handle<JSReceiver> getter = Handle<JSReceiver>();
+    if (desc.has_get() && desc.get()->IsCallable()) {
+      getter = Handle<JSReceiver>::cast(desc.get());
+    }
+    Handle<JSReceiver> setter = Handle<JSReceiver>();
+    if (desc.has_set() && desc.set()->IsCallable()) {
+      setter = Handle<JSReceiver>::cast(desc.set());
+    }
+    propDescriptor.reset(new v8::PropertyDescriptor(
+        v8::Utils::CallableToLocal(getter), desc.has_get(),
+        v8::Utils::CallableToLocal(setter), desc.has_set()));
+  } else if (PropertyDescriptor::IsDataDescriptor(&desc)) {
+    propDescriptor.reset(new v8::PropertyDescriptor(
+        v8::Utils::ToLocal(desc.value()), desc.has_value(), desc.writable(),
+        desc.has_writable()));
+  }
+  if (desc.has_enumerable()) {
+    propDescriptor->set_enumerable(desc.enumerable());
+  }
+  if (desc.has_configurable()) {
+    propDescriptor->set_configurable(desc.configurable());
+  }
+
+  if (it->IsElement()) {
+    uint32_t index = it->index();
+    v8::IndexedPropertyDefinerCallback definer =
+        v8::ToCData<v8::IndexedPropertyDefinerCallback>(interceptor->definer());
+    result = !args.Call(definer, index, *propDescriptor).is_null();
+  } else {
+    Handle<Name> name = it->name();
+    DCHECK(!name->IsPrivate());
+
+    if (name->IsSymbol() && !interceptor->can_intercept_symbols()) {
+      return Just(false);
+    }
+
+    v8::GenericNamedPropertyDefinerCallback definer =
+        v8::ToCData<v8::GenericNamedPropertyDefinerCallback>(
+            interceptor->definer());
+    result = !args.Call(definer, name, *propDescriptor).is_null();
+  }
+
+  RETURN_VALUE_IF_SCHEDULED_EXCEPTION(it->isolate(), Nothing<bool>());
+  return Just(result);
+}
+
 }  // namespace
 
 MaybeHandle<Object> JSObject::GetPropertyWithFailedAccessCheck(
     LookupIterator* it) {
   Isolate* isolate = it->isolate();
   Handle<JSObject> checked = it->GetHolder<JSObject>();
   Handle<InterceptorInfo> interceptor =
       it->GetInterceptorForFailedAccessCheck();
   if (interceptor.is_null()) {
     while (AllCanRead(it)) {
@@ skipping 2828 matching lines @@
 }
 
 Maybe<bool> JSObject::SetPropertyWithInterceptor(LookupIterator* it,
                                                  ShouldThrow should_throw,
                                                  Handle<Object> value) {
   DCHECK_EQ(LookupIterator::INTERCEPTOR, it->state());
   return SetPropertyWithInterceptorInternal(it, it->GetInterceptor(),
                                             should_throw, value);
 }
 
+Maybe<bool> JSObject::DefinePropertyWithInterceptor(LookupIterator* it,
+                                                    ShouldThrow should_throw,
+                                                    PropertyDescriptor& desc) {
+  DCHECK_EQ(LookupIterator::INTERCEPTOR, it->state());
+  return DefinePropertyWithInterceptorInternal(it, it->GetInterceptor(),

[jochen (gone - plz use gerrit), 2016/08/26 18:18:46]

just inline this method, as it's not used from anywhere else

[Franzi, 2016/09/01 06:38:18]

Done.

+                                               should_throw, desc);
+}
+
 MaybeHandle<Object> Object::SetProperty(Handle<Object> object,
                                         Handle<Name> name, Handle<Object> value,
                                         LanguageMode language_mode,
                                         StoreFromKeyed store_mode) {
   LookupIterator it(object, name);
   MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_mode));
   return value;
 }
 
 
@@ skipping 1997 matching lines @@
   // Deal with access checks first.
   if (it.state() == LookupIterator::ACCESS_CHECK) {
     if (!it.HasAccess()) {
       isolate->ReportFailedAccessCheck(it.GetHolder<JSObject>());
       RETURN_VALUE_IF_SCHEDULED_EXCEPTION(isolate, Nothing<bool>());
       return Just(true);
     }
     it.Next();
   }
 
+  // Handle interceptor
+  if (it.state() == LookupIterator::INTERCEPTOR) {
+    Handle<Map> store_target_map;
+    if (it.GetReceiver()->IsJSObject()) {
+      store_target_map = handle(it.GetStoreTarget()->map(), it.isolate());
+    }
+    if (it.HolderIsReceiverOrHiddenPrototype()) {
+      Maybe<bool> result =
+          JSObject::DefinePropertyWithInterceptor(&it, should_throw, *desc);
+      if (result.IsNothing() || result.FromJust()) {
+        return result;
+      }
+      // Interceptor modified the store target but failed to set the
+      // property.
+      if (!store_target_map.is_null() &&
+          *store_target_map != it.GetStoreTarget()->map()) {
+        it.isolate()->PushStackTraceAndDie(
+            0xabababaa, v8::ToCData<void*>(it.GetInterceptor()->setter()),
+            nullptr, 0xabababab);
+      }
+      Utils::ApiCheck(store_target_map.is_null() ||
+                          *store_target_map == it.GetStoreTarget()->map(),
+                      it.IsElement() ? "v8::IndexedPropertySetterCallback"
+                                     : "v8::NamedPropertySetterCallback",
+                      "Interceptor silently changed store target.");
+    }
+    it.Next();
+  }
+
   return OrdinaryDefineOwnProperty(&it, desc, should_throw);
 }
 
 
 // ES6 9.1.6.1
 // static
 Maybe<bool> JSReceiver::OrdinaryDefineOwnProperty(LookupIterator* it,
                                                   PropertyDescriptor* desc,
                                                   ShouldThrow should_throw) {
   Isolate* isolate = it->isolate();
@@ skipping 12775 matching lines @@
   for (PrototypeIterator iter(isolate, this, kStartAtReceiver,
                               PrototypeIterator::END_AT_NULL);
        !iter.IsAtEnd(); iter.AdvanceIgnoringProxies()) {
     if (iter.GetCurrent<Object>()->IsJSProxy()) return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8