Added handling of hidden prototype objects when collecting local properties f...

src/runtime.cc

 // Copyright 2006-2008 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
@@ skipping 4518 matching lines @@
 }
 
 
 static Object* Runtime_Break(Arguments args) {
   ASSERT(args.length() == 0);
   StackGuard::DebugBreak();
   return Heap::undefined_value();
 }
 
 
+// Find the length of the prototype chain that is to to handled as one. If a
+// prototype object is hidden it is to be viewed as part of the the object it
+// is prototype for.
+static int LocalPrototypeChainLength(JSObject* obj) {
+  int count = 1;
+  Object* proto = obj->GetPrototype();
+  while (proto->IsJSObject() &&
+         JSObject::cast(proto)->map()->is_hidden_prototype()) {
+    count++;
+    proto = JSObject::cast(proto)->GetPrototype();
+  }
+  return count;
+}
+
+
 static Object* DebugLookupResultValue(Object* receiver, LookupResult* result,
                                       bool* caught_exception) {
   Object* value;
   switch (result->type()) {
     case NORMAL: {
       Dictionary* dict =
           JSObject::cast(result->holder())->property_dictionary();
       value = dict->ValueAt(result->GetDictionaryEntry());
       if (value->IsTheHole()) {
         return Heap::undefined_value();
@@ skipping 55 matching lines @@
 // Items 2-4 are only filled if the property has either a getter or a setter
 // defined through __defineGetter__ and/or __defineSetter__.
 static Object* Runtime_DebugGetPropertyDetails(Arguments args) {
   HandleScope scope;
 
   ASSERT(args.length() == 2);
 
   CONVERT_ARG_CHECKED(JSObject, obj, 0);
   CONVERT_ARG_CHECKED(String, name, 1);
 
+  // Skip the global proxy as it has no properties and always delegates to the
+  // real global object.
+  if (obj->IsJSGlobalProxy()) {
+    obj = Handle<JSObject>(JSObject::cast(obj->GetPrototype()));
+  }
+
+
   // Check if the name is trivially convertible to an index and get the element
   // if so.
   uint32_t index;
   if (name->AsArrayIndex(&index)) {
     Handle<FixedArray> details = Factory::NewFixedArray(2);
     details->set(0, Runtime::GetElementOrCharAt(obj, index));
     details->set(1, PropertyDetails(NONE, NORMAL).AsSmi());
     return *Factory::NewJSArrayWithElements(details);
   }
 
-  // Perform standard local lookup on the object.
+  // Find the number of objects making up this.
+  int length = LocalPrototypeChainLength(*obj);
+
+  // Try local lookup on each of the objects.
   LookupResult result;
-  obj->LocalLookup(*name, &result);
+  Handle<JSObject> jsproto = obj;
+  for (int i = 0; i < length; i++) {
+    jsproto->LocalLookup(*name, &result);
+    if (result.IsProperty()) {
+      break;
+    }
+    if (i < length - 1) {
+      jsproto = Handle<JSObject>(JSObject::cast(jsproto->GetPrototype()));
+    }
+  }
+
   if (result.IsProperty()) {
     bool caught_exception = false;
     Handle<Object> value(DebugLookupResultValue(*obj, &result,
                                                 &caught_exception));
     // If the callback object is a fixed array then it contains JavaScript
     // getter and/or setter.
     bool hasJavaScriptAccessors = result.type() == CALLBACKS &&
                                   result.GetCallbackObject()->IsFixedArray();
     Handle<FixedArray> details =
         Factory::NewFixedArray(hasJavaScriptAccessors ? 5 : 2);
@@ skipping 32 matching lines @@
 // Return the names of the local named properties.
 // args[0]: object
 static Object* Runtime_DebugLocalPropertyNames(Arguments args) {
   HandleScope scope;
   ASSERT(args.length() == 1);
   if (!args[0]->IsJSObject()) {
     return Heap::undefined_value();
   }
   CONVERT_ARG_CHECKED(JSObject, obj, 0);
 
+  // Skip the global proxy as it has no properties and always delegates to the
+  // real global object.
   if (obj->IsJSGlobalProxy()) {
     obj = Handle<JSObject>(JSObject::cast(obj->GetPrototype()));
   }
-  int n = obj->NumberOfLocalProperties(static_cast<PropertyAttributes>(NONE));
-  Handle<FixedArray> names = Factory::NewFixedArray(n);
-  obj->GetLocalPropertyNames(*names);
+
+  // Find the number of objects making up this.
+  int length = LocalPrototypeChainLength(*obj);
+
+  // Find the number of local properties for each of the objects.
+  int* local_property_count = NewArray<int>(length);
+  int total_property_count = 0;
+  Handle<JSObject> jsproto = obj;
+  for (int i = 0; i < length; i++) {
+    int n;
+    n = jsproto->NumberOfLocalProperties(static_cast<PropertyAttributes>(NONE));
+    local_property_count[i] = n;
+    total_property_count += n;
+    if (i < length - 1) {
+      jsproto = Handle<JSObject>(JSObject::cast(jsproto->GetPrototype()));
+    }
+  }
+
+  // Allocate an array with storage for all the property names.
+  Handle<FixedArray> names = Factory::NewFixedArray(total_property_count);
+
+  // Get the property names.
+  jsproto = obj;
+  for (int i = 0; i < length; i++) {
+    jsproto->GetLocalPropertyNames(*names,
+                                   i == 0 ? 0 : local_property_count[i - 1]);
+    if (i < length - 1) {
+      jsproto = Handle<JSObject>(JSObject::cast(jsproto->GetPrototype()));
+    }
+  }
+
+  DeleteArray(local_property_count);
   return *Factory::NewJSArrayWithElements(names);
 }
 
 
 // Return the names of the local indexed properties.
 // args[0]: object
 static Object* Runtime_DebugLocalElementNames(Arguments args) {
   HandleScope scope;
   ASSERT(args.length() == 1);
   if (!args[0]->IsJSObject()) {
@@ skipping 1107 matching lines @@
 
   // Return result as JS array.
   Object* result =
       Heap::AllocateJSObject(
           Top::context()->global_context()->array_function());
   if (!result->IsFailure()) JSArray::cast(result)->SetContent(instances);
   return result;
 }
 
 
-static Object* Runtime_GetPrototype(Arguments args) {
+// Find the effective prototype object as returned by __proto__.
+// args[0]: the object to find the prototype for.
+static Object* Runtime_DebugGetPrototype(Arguments args) {
   ASSERT(args.length() == 1);
 
   CONVERT_CHECKED(JSObject, obj, args[0]);
 
-  return obj->GetPrototype();
+  // Use the __proto__ accessor.
+  return Accessors::ObjectPrototype.getter(obj, NULL);
 }
 
 
 static Object* Runtime_SystemBreak(Arguments args) {
   ASSERT(args.length() == 0);
   CPU::DebugBreak();
   return Heap::undefined_value();
 }
 
 
@@ skipping 153 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage();
   }
 }
 
 
 } }  // namespace v8::internal