[es2015] Precompute the descriptive string for symbols.

src/heap/heap.cc

 // Copyright 2012 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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/assembler-inl.h"
 #include "src/ast/context-slot-cache.h"
@@ skipping 2718 matching lines @@
   // Create the code_stubs dictionary. The initial size is set to avoid
   // expanding the dictionary during bootstrapping.
   set_code_stubs(*UnseededNumberDictionary::New(isolate(), 128));
 
   set_instanceof_cache_function(Smi::kZero);
   set_instanceof_cache_map(Smi::kZero);
   set_instanceof_cache_answer(Smi::kZero);
 
   {
     HandleScope scope(isolate());
-#define SYMBOL_INIT(name)                                              \
-  {                                                                    \
-    Handle<String> name##d = factory->NewStringFromStaticChars(#name); \
-    Handle<Symbol> symbol(isolate()->factory()->NewPrivateSymbol());   \
-    symbol->set_name(*name##d);                                        \
-    roots_[k##name##RootIndex] = *symbol;                              \
+#define SYMBOL_INIT(name)                                                  \
+  {                                                                        \
+    Handle<String> name##d = factory->NewStringFromStaticChars(#name);     \
+    Handle<Symbol> name =                                                  \
+        isolate()->factory()->NewPrivateSymbol(name##d).ToHandleChecked(); \
+    roots_[k##name##RootIndex] = *name;                                    \
   }
     PRIVATE_SYMBOL_LIST(SYMBOL_INIT)
 #undef SYMBOL_INIT
   }
 
   {
     HandleScope scope(isolate());
 #define SYMBOL_INIT(name, description)                                      \
-  Handle<Symbol> name = factory->NewSymbol();                               \
   Handle<String> name##d = factory->NewStringFromStaticChars(#description); \
-  name->set_name(*name##d);                                                 \
+  Handle<Symbol> name = factory->NewSymbol(name##d).ToHandleChecked();      \
   roots_[k##name##RootIndex] = *name;
     PUBLIC_SYMBOL_LIST(SYMBOL_INIT)
 #undef SYMBOL_INIT
 
 #define SYMBOL_INIT(name, description)                                      \
-  Handle<Symbol> name = factory->NewSymbol();                               \
   Handle<String> name##d = factory->NewStringFromStaticChars(#description); \
+  Handle<Symbol> name = factory->NewSymbol(name##d).ToHandleChecked();      \
   name->set_is_well_known_symbol(true);                                     \
-  name->set_name(*name##d);                                                 \
   roots_[k##name##RootIndex] = *name;
     WELL_KNOWN_SYMBOL_LIST(SYMBOL_INIT)
 #undef SYMBOL_INIT
   }
 
   Handle<NameDictionary> empty_properties_dictionary =
       NameDictionary::NewEmpty(isolate(), TENURED);
   empty_properties_dictionary->SetRequiresCopyOnCapacityChange();
   set_empty_properties_dictionary(*empty_properties_dictionary);
 
@@ skipping 1294 matching lines @@
   if (!allocation.To(&result)) return allocation;
 
   result->set_map_after_allocation(symbol_map(), SKIP_WRITE_BARRIER);
 
   // Generate a random hash value.
   int hash = isolate()->GenerateIdentityHash(Name::kHashBitMask);
 
   Symbol::cast(result)
       ->set_hash_field(Name::kIsNotArrayIndexMask | (hash << Name::kHashShift));
   Symbol::cast(result)->set_name(undefined_value());
+  Symbol::cast(result)->set_descriptive_string(Symbol_parens_string());
   Symbol::cast(result)->set_flags(0);
 
   DCHECK(!Symbol::cast(result)->is_private());
   return result;
 }
 
 
 AllocationResult Heap::AllocateStruct(InstanceType type) {
   Map* map;
   switch (type) {
@@ skipping 2486 matching lines @@
     case LO_SPACE:
       return "LO_SPACE";
     default:
       UNREACHABLE();
   }
   return NULL;
 }
 
 }  // namespace internal
 }  // namespace v8