Implement delete trap for proxies.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ca780dbe0ea44bbf81cf337e7494afcd507fd933..cac68294dd66942d355dc948662105a4c1150b0b 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -2233,6 +2233,44 @@ MUST_USE_RESULT MaybeObject* JSProxy::SetPropertyWithHandler(
 }
 
 
+MUST_USE_RESULT MaybeObject* JSProxy::DeletePropertyWithHandler(
+    String* name_raw, DeleteMode mode) {
+  Isolate* isolate = GetIsolate();
+  HandleScope scope;

[Mads Ager (chromium), 2011/07/14 16:17:22]

You should pass in the isolate to the HandleScope constructor so it will not go
through thread-local storage to get it.

[rossberg, 2011/07/15 08:47:40]

Done, here and in a number of other places.

+  Handle<Object> receiver(this);
+  Handle<Object> name(name_raw);
+  Handle<Object> handler(this->handler());
+
+  // Extract trap function.
+  Handle<String> trap_name = isolate->factory()->LookupAsciiSymbol("delete");
+  Handle<Object> trap(v8::internal::GetProperty(handler, trap_name));
+  if (trap->IsUndefined()) {
+    Handle<Object> args[] = { handler, trap_name };
+    Handle<Object> error = isolate->factory()->NewTypeError(
+        "handler_trap_missing", HandleVector(args, ARRAY_SIZE(args)));
+    isolate->Throw(*error);
+    return Failure::Exception();
+  }
+
+  // Call trap function.
+  Object** args[] = { name.location() };
+  bool has_exception;
+  Handle<Object> result =
+      Execution::Call(trap, handler, ARRAY_SIZE(args), args, &has_exception);
+  if (has_exception) return Failure::Exception();
+
+  Object* bool_result = result->ToBoolean();
+  if (mode != NORMAL_DELETION && bool_result == GetHeap()->false_value()) {

[Mads Ager (chromium), 2011/07/14 16:17:22]

Do we want this behavior for FORCE_DELETION as well? I would have guessed that
the test should be mode == STRICT_DELETION?

[rossberg, 2011/07/15 08:47:40]

Done.

+    Handle<Object> args[] = { handler, trap_name };
+    Handle<Object> error = isolate->factory()->NewTypeError(
+        "handler_failed", HandleVector(args, ARRAY_SIZE(args)));
+    isolate->Throw(*error);
+    return Failure::Exception();
+  }
+  return bool_result;
+}
+
+
 MUST_USE_RESULT PropertyAttributes JSProxy::GetPropertyAttributeWithHandler(
     JSReceiver* receiver_raw,
     String* name_raw,
@@ -3179,6 +3217,15 @@ MaybeObject* JSObject::DeleteElement(uint32_t index, DeleteMode mode) {
 }
 
 
+MaybeObject* JSReceiver::DeleteProperty(String* name, DeleteMode mode) {
+  if (IsJSProxy()) {
+    return JSProxy::cast(this)->DeletePropertyWithHandler(name, mode);
+  } else {
+    return JSObject::cast(this)->DeleteProperty(name, mode);
+  }
+}
+
+
 MaybeObject* JSObject::DeleteProperty(String* name, DeleteMode mode) {
   Isolate* isolate = GetIsolate();
   // ECMA-262, 3rd, 8.6.2.5
@@ -11053,11 +11100,11 @@ void NumberDictionary::RemoveNumberEntries(uint32_t from, uint32_t to) {
 
 template<typename Shape, typename Key>
 Object* Dictionary<Shape, Key>::DeleteProperty(int entry,
-                                               JSObject::DeleteMode mode) {
+                                               JSReceiver::DeleteMode mode) {
   Heap* heap = Dictionary<Shape, Key>::GetHeap();
   PropertyDetails details = DetailsAt(entry);
   // Ignore attributes if forcing a deletion.
-  if (details.IsDontDelete() && mode != JSObject::FORCE_DELETION) {
+  if (details.IsDontDelete() && mode != JSReceiver::FORCE_DELETION) {
     return heap->false_value();
   }
   SetEntry(entry, heap->null_value(), heap->null_value());