Teach JSReceiver::GetKeys() how to include symbols

src/objects.cc

 // Copyright 2013 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 <sstream>
 
@@ skipping 6813 matching lines @@
     DisallowHeapAllocation no_gc;
     WriteBarrierMode mode = new_keys->GetWriteBarrierMode(no_gc);
     for (int i = 0; i < buffer_length; i++) {
       new_keys->set(i, keys_->get(i), mode);
     }
   }
   keys_ = new_keys;
 }
 
 
-MaybeHandle<FixedArray> JSReceiver::GetKeys(Handle<JSReceiver> object,
-                                            KeyCollectionType type) {
+MaybeHandle<FixedArray> JSReceiver::GetKeys(
+    Handle<JSReceiver> object, KeyCollectionType type,
+    IncludeSymbolNamedProperties include_symbols) {
   USE(ContainsOnlyValidKeys);
   Isolate* isolate = object->GetIsolate();
   KeyAccumulator accumulator(isolate);
   Handle<JSFunction> arguments_function(
       JSFunction::cast(isolate->sloppy_arguments_map()->GetConstructor()));
 
   PrototypeIterator::WhereToEnd end = type == OWN_ONLY
                                           ? PrototypeIterator::END_AT_NON_HIDDEN
                                           : PrototypeIterator::END_AT_NULL;
   // Only collect keys if access is permitted.
@@ skipping 37 matching lines @@
     // Add the element keys from the interceptor.
     if (current->HasIndexedInterceptor()) {
       Handle<JSObject> result;
       if (JSObject::GetKeysForIndexedInterceptor(
               current, object).ToHandle(&result)) {
         accumulator.AddKeys(result, FixedArray::ALL_KEYS);
       }
       DCHECK(ContainsOnlyValidKeys(accumulator.GetKeys()));
     }
 
-    // We can cache the computed property keys if access checks are
-    // not needed and no interceptors are involved.
-    //
-    // We do not use the cache if the object has elements and
-    // therefore it does not make sense to cache the property names
-    // for arguments objects.  Arguments objects will always have
-    // elements.
-    // Wrapped strings have elements, but don't have an elements
-    // array or dictionary.  So the fast inline test for whether to
-    // use the cache says yes, so we should not create a cache.
-    bool cache_enum_keys =
-        ((current->map()->GetConstructor() != *arguments_function) &&
-         !current->IsJSValue() && !current->IsAccessCheckNeeded() &&
-         !current->HasNamedInterceptor() && !current->HasIndexedInterceptor());
-    // Compute the property keys and cache them if possible.
-
-    Handle<FixedArray> enum_keys =
-        JSObject::GetEnumPropertyKeys(current, cache_enum_keys);
-    accumulator.AddKeys(enum_keys, FixedArray::ALL_KEYS);
+    if (include_symbols == SKIP_SYMBOLS) {
+      // We can cache the computed property keys if access checks are
+      // not needed and no interceptors are involved.
+      //
+      // We do not use the cache if the object has elements and
+      // therefore it does not make sense to cache the property names
+      // for arguments objects.  Arguments objects will always have
+      // elements.
+      // Wrapped strings have elements, but don't have an elements
+      // array or dictionary.  So the fast inline test for whether to
+      // use the cache says yes, so we should not create a cache.
+      bool cache_enum_keys =
+          ((current->map()->GetConstructor() != *arguments_function) &&
+           !current->IsJSValue() && !current->IsAccessCheckNeeded() &&
+           !current->HasNamedInterceptor() &&
+           !current->HasIndexedInterceptor());
+      // Compute the property keys and cache them if possible.
+      Handle<FixedArray> enum_keys =
+          JSObject::GetEnumPropertyKeys(current, cache_enum_keys);
+      accumulator.AddKeys(enum_keys, FixedArray::ALL_KEYS);
+    } else {
+      DCHECK(include_symbols == INCLUDE_SYMBOLS);
+      PropertyAttributes filter =
+          static_cast<PropertyAttributes>(DONT_ENUM | PRIVATE_SYMBOL);
+      Handle<FixedArray> property_keys = isolate->factory()->NewFixedArray(
+          current->NumberOfOwnProperties(filter));
+      current->GetOwnPropertyNames(*property_keys, 0, filter);

[Camillo Bruni, 2015/09/29 16:27:20]

Not sure how much work this would be, but essentially you could add the property
names directly to the accumulator and avoid the property_keys temporary. Might
be harder for the dict paths in GetOwnPropertyNames.

[Jakob Kummerow, 2015/09/30 13:59:30]

I'm leaving that to you :-)

+      accumulator.AddKeys(property_keys, FixedArray::ALL_KEYS);
+    }
     DCHECK(ContainsOnlyValidKeys(accumulator.GetKeys()));
 
-    // Add the non-symbol property keys from the interceptor.
+    // Add the property keys from the interceptor.
     if (current->HasNamedInterceptor()) {
       Handle<JSObject> result;
       if (JSObject::GetKeysForNamedInterceptor(
               current, object).ToHandle(&result)) {
-        accumulator.AddKeys(result, FixedArray::NON_SYMBOL_KEYS);
+        FixedArray::KeyFilter filter = include_symbols == SKIP_SYMBOLS
+                                           ? FixedArray::NON_SYMBOL_KEYS
+                                           : FixedArray::ALL_KEYS;
+        accumulator.AddKeys(result, filter);
       }
       DCHECK(ContainsOnlyValidKeys(accumulator.GetKeys()));
     }
   }
 
   Handle<FixedArray> keys = accumulator.GetKeys();
   DCHECK(ContainsOnlyValidKeys(keys));
   return keys;
 }
 
@@ skipping 6895 matching lines @@
     return global_dictionary()->CopyKeysTo(storage, index, filter,
                                            GlobalDictionary::UNSORTED);
   } else {
     return property_dictionary()->CopyKeysTo(storage, index, filter,
                                              NameDictionary::UNSORTED);
   }
 }
 
 
 int JSObject::NumberOfOwnElements(PropertyAttributes filter) {
-  return GetOwnElementKeys(NULL, filter);
-}
-
-
-int JSObject::NumberOfEnumElements() {
   // Fast case for objects with no elements.
-  if (!IsJSValue() && HasFastObjectElements()) {
+  if (!IsJSValue() && HasFastElements()) {
     uint32_t length = IsJSArray() ?
         static_cast<uint32_t>(
             Smi::cast(JSArray::cast(this)->length())->value()) :
         static_cast<uint32_t>(FixedArray::cast(elements())->length());
     if (length == 0) return 0;
   }
   // Compute the number of enumerable elements.
+  return GetOwnElementKeys(NULL, filter);
+}
+
+
+int JSObject::NumberOfEnumElements() {
   return NumberOfOwnElements(static_cast<PropertyAttributes>(DONT_ENUM));
 }
 
 
 int JSObject::GetOwnElementKeys(FixedArray* storage,
                                 PropertyAttributes filter) {
   int counter = 0;
 
   // If this is a String wrapper, add the string indices first,
   // as they're guaranteed to preced the elements in numerical order
@@ skipping 2942 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8