Provide private symbols through internal APIs

src/heap.cc

 // Copyright 2012 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 3261 matching lines @@
 
   // Allocate object to hold object observation state.
   { MaybeObject* maybe_obj = AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   { MaybeObject* maybe_obj = AllocateJSObjectFromMap(Map::cast(obj));
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_observation_state(JSObject::cast(obj));
 
-  { MaybeObject* maybe_obj = AllocateSymbol();
+  { MaybeObject* maybe_obj = AllocatePrivate();
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_frozen_symbol(Symbol::cast(obj));
 
-  { MaybeObject* maybe_obj = AllocateSymbol();
+  { MaybeObject* maybe_obj = AllocatePrivate();
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_elements_transition_symbol(Symbol::cast(obj));
 
   { MaybeObject* maybe_obj = SeededNumberDictionary::Allocate(this, 0, TENURED);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   SeededNumberDictionary::cast(obj)->set_requires_slow_elements();
   set_empty_slow_element_dictionary(SeededNumberDictionary::cast(obj));
 
-  { MaybeObject* maybe_obj = AllocateSymbol();
+  { MaybeObject* maybe_obj = AllocatePrivate();
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_observed_symbol(Symbol::cast(obj));
 
   // Handling of script id generation is in Factory::NewScript.
   set_last_script_id(Smi::FromInt(v8::Script::kNoScriptId));
 
   // Initialize keyed lookup cache.
   isolate_->keyed_lookup_cache()->Clear();
 
@@ skipping 2280 matching lines @@
   do {
     hash = isolate()->random_number_generator()->NextInt() & Name::kHashBitMask;
     attempts++;
   } while (hash == 0 && attempts < 30);
   if (hash == 0) hash = 1;  // never return 0
 
   Symbol::cast(result)->set_hash_field(
       Name::kIsNotArrayIndexMask | (hash << Name::kHashShift));
   Symbol::cast(result)->set_name(undefined_value());
 
-  ASSERT(result->IsSymbol());
+  ASSERT(result->IsSymbol() && !result->IsPrivate());
   return result;
 }
 
+
+MaybeObject* Heap::AllocatePrivate() {
+  STATIC_ASSERT(Private::kSize == Symbol::kSize);
+  MaybeObject* maybe = AllocateSymbol();
+  Symbol* result;
+  if (!maybe->To(&result)) return maybe;
+  maybe = AllocateBox(undefined_value(), TENURED);
+  Box* box;
+  if (!maybe->To(&box)) return maybe;
+  result->set_name(box);  // Marker for private.
+  ASSERT(result->IsPrivate());
+  return result;
+}
+
 
 MaybeObject* Heap::AllocateNativeContext() {
   Object* result;
   { MaybeObject* maybe_result =
         AllocateFixedArray(Context::NATIVE_CONTEXT_SLOTS);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   Context* context = reinterpret_cast<Context*>(result);
   context->set_map_no_write_barrier(native_context_map());
   context->set_js_array_maps(undefined_value());
@@ skipping 2354 matching lines @@
   if (FLAG_concurrent_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal