ES6 symbols: Implement Symbol intrinsic and basic functionality

src/stub-cache.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 554 matching lines @@
                                             Handle<JSFunction> function) {
   // Compute the check type and the map.
   InlineCacheHolderFlag cache_holder =
       IC::GetCodeCacheForObject(*object, *holder);
   Handle<JSObject> map_holder(IC::GetCodeCacheHolder(*object, cache_holder));
 
   // Compute check type based on receiver/holder.
   CheckType check = RECEIVER_MAP_CHECK;
   if (object->IsString()) {
     check = STRING_CHECK;
+  } else if (object->IsSymbol()) {
+    check = SYMBOL_CHECK;
   } else if (object->IsNumber()) {
     check = NUMBER_CHECK;
   } else if (object->IsBoolean()) {
     check = BOOLEAN_CHECK;
   }
 
   Code::Flags flags =
       Code::ComputeMonomorphicFlags(kind, Code::CONSTANT_FUNCTION, extra_state,
                                     cache_holder, argc);
   Handle<Object> probe(map_holder->map()->FindInCodeCache(*name, flags),
@@ skipping 21 matching lines @@
                                          Handle<JSObject> holder,
                                          PropertyIndex index) {
   // Compute the check type and the map.
   InlineCacheHolderFlag cache_holder =
       IC::GetCodeCacheForObject(*object, *holder);
   Handle<JSObject> map_holder(IC::GetCodeCacheHolder(*object, cache_holder));
 
   // TODO(1233596): We cannot do receiver map check for non-JS objects
   // because they may be represented as immediates without a
   // map. Instead, we check against the map in the holder.
-  if (object->IsNumber() || object->IsBoolean() || object->IsString()) {
+  if (object->IsNumber() || object->IsSymbol() ||
+      object->IsBoolean() || object->IsString()) {
     object = holder;
   }
 
   Code::Flags flags =
       Code::ComputeMonomorphicFlags(kind, Code::FIELD, extra_state,
                                     cache_holder, argc);
   Handle<Object> probe(map_holder->map()->FindInCodeCache(*name, flags),
                        isolate_);
   if (probe->IsCode()) return Handle<Code>::cast(probe);
 
@@ skipping 17 matching lines @@
                                                Handle<Object> object,
                                                Handle<JSObject> holder) {
   // Compute the check type and the map.
   InlineCacheHolderFlag cache_holder =
       IC::GetCodeCacheForObject(*object, *holder);
   Handle<JSObject> map_holder(IC::GetCodeCacheHolder(*object, cache_holder));
 
   // TODO(1233596): We cannot do receiver map check for non-JS objects
   // because they may be represented as immediates without a
   // map. Instead, we check against the map in the holder.
-  if (object->IsNumber() || object->IsBoolean() || object->IsString()) {
+  if (object->IsNumber() || object->IsSymbol() ||
+      object->IsBoolean() || object->IsString()) {
     object = holder;
   }
 
   Code::Flags flags =
       Code::ComputeMonomorphicFlags(kind, Code::INTERCEPTOR, extra_state,
                                     cache_holder, argc);
   Handle<Object> probe(map_holder->map()->FindInCodeCache(*name, flags),
                        isolate_);
   if (probe->IsCode()) return Handle<Code>::cast(probe);
 
@@ skipping 1089 matching lines @@
           Handle<FunctionTemplateInfo>(
               FunctionTemplateInfo::cast(signature->receiver()));
     }
   }
 
   is_simple_api_call_ = true;
 }
 
 
 } }  // namespace v8::internal