Verify the symbol table contents before and after all...

src/objects.cc

 // Copyright 2006-2009 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 661 matching lines @@
 
 
 bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
 #ifdef DEBUG
   {  // NOLINT (presubmit.py gets confused about if and braces)
     // Assert that the resource and the string are equivalent.
     ASSERT(static_cast<size_t>(this->length()) == resource->length());
     SmartPointer<uc16> smart_chars = this->ToWideCString();
     ASSERT(memcmp(*smart_chars,
                   resource->data(),
-                  resource->length()*sizeof(**smart_chars)) == 0);
+                  resource->length() * sizeof(**smart_chars)) == 0);
   }
 #endif  // DEBUG
 
   int size = this->Size();  // Byte size of the original string.
   if (size < ExternalString::kSize) {
     // The string is too small to fit an external String in its place. This can
     // only happen for zero length strings.
     return false;
   }
   ASSERT(size >= ExternalString::kSize);
@@ skipping 5604 matching lines @@
   }
 
   uint32_t Hash() { return string_->Hash(); }
 
   Object* GetObject() {
     // If the string is a cons string, attempt to flatten it so that
     // symbols will most often be flat strings.
     if (StringShape(string_).IsCons()) {
       ConsString* cons_string = ConsString::cast(string_);
       cons_string->TryFlatten();
-      if (cons_string->second() == Heap::empty_string()) {
+      if (cons_string->second()->length() == 0) {
         string_ = cons_string->first();
       }
     }
     // Transform string to symbol if possible.
     Map* map = Heap::SymbolMapForString(string_);
     if (map != NULL) {
       string_->set_map(map);
+      ASSERT(string_->IsSymbol());
       return string_;
     }
     // Otherwise allocate a new symbol.
     StringInputBuffer buffer(string_);
     return Heap::AllocateInternalSymbol(&buffer,
                                         string_->length(),
                                         string_->length_field());
   }
 
   static uint32_t StringHash(Object* obj) {
@@ skipping 1092 matching lines @@
   // No break point.
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 
 
 } }  // namespace v8::internal