Improve printing for 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 <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
@@ skipping 1516 matching lines @@
         os << "<true>";
       } else if (IsFalse()) {
         os << "<false>";
       } else {
         os << "<Odd Oddball>";
       }
       break;
     }
     case SYMBOL_TYPE: {
       Symbol* symbol = Symbol::cast(this);
-      os << "<Symbol: " << symbol->Hash();
-      if (!symbol->name()->IsUndefined()) {
-        os << " ";
-        HeapStringAllocator allocator;
-        StringStream accumulator(&allocator);
-        String::cast(symbol->name())->StringShortPrint(&accumulator);
-        os << accumulator.ToCString().get();
-      }
-      os << ">";
+      symbol->SymbolShortPrint(os);
       break;
     }
     case HEAP_NUMBER_TYPE: {
       os << "<Number: ";
       HeapNumber::cast(this)->HeapNumberPrint(os);
       os << ">";
       break;
     }
     case MUTABLE_HEAP_NUMBER_TYPE: {
       os << "<MutableNumber: ";
@@ skipping 12067 matching lines @@
   DCHECK(!storage || storage->length() == counter);
   return counter;
 }
 
 
 int JSObject::GetEnumElementKeys(FixedArray* storage) {
   return GetOwnElementKeys(storage, static_cast<PropertyAttributes>(DONT_ENUM));
 }
 
 
+const char* Symbol::PrivateSymbolToName() const {
+  Heap* heap = GetIsolate()->heap();
+#define SYMBOL_CHECK_AND_PRINT(name) \
+  if (this == heap->name()) return #name;
+  PRIVATE_SYMBOL_LIST(SYMBOL_CHECK_AND_PRINT)
+#undef SYMBOL_CHECK_AND_PRINT
+  return "UNKNOWN";
+}
+
+
+void Symbol::SymbolShortPrint(std::ostream& os) {
+  os << "<Symbol: " << Hash();
+  if (!name()->IsUndefined()) {
+    os << " ";
+    HeapStringAllocator allocator;
+    StringStream accumulator(&allocator);
+    String::cast(name())->StringShortPrint(&accumulator);
+    os << accumulator.ToCString().get();
+  } else {
+    os << " (" << PrivateSymbolToName() << ")";
+  }
+  os << ">";
+}
+
+
 // StringSharedKeys are used as keys in the eval cache.
 class StringSharedKey : public HashTableKey {
  public:
   StringSharedKey(Handle<String> source,
                   Handle<SharedFunctionInfo> shared,
                   StrictMode strict_mode,
                   int scope_position)
       : source_(source),
         shared_(shared),
         strict_mode_(strict_mode),
@@ skipping 2826 matching lines @@
   Handle<DependentCode> codes =
       DependentCode::Insert(handle(cell->dependent_code(), info->isolate()),
                             DependentCode::kPropertyCellChangedGroup,
                             info->object_wrapper());
   if (*codes != cell->dependent_code()) cell->set_dependent_code(*codes);
   info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
       cell, info->zone());
 }
 
 } }  // namespace v8::internal