Add a second kind of HandleScope that ties the lifetime of Handles created in its scope to the life…

src/handles.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 940 matching lines @@
   const int kRecursionBudget = 100;
   do {
     failure = false;
     len = Utf8LengthHelper(
         *str, 0, str->length(), false, kRecursionBudget, &failure, &dummy);
     if (failure) FlattenString(str);
   } while (failure);
   return len;
 }
 
+
+GatheringHandleScope::GatheringHandleScope(CompilationInfo* info)
+    : info_(info) {
+  Isolate* isolate = info->isolate();
+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  prev_next_ = current->next;
+  prev_limit_ = current->limit;
+
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  impl->set_last_block_before_compilation();
+  Object** new_next = impl->GetSpareOrNewBlock();
+  Object** new_limit = &new_next[kHandleBlockSize];
+  impl->blocks()->Add(new_next);
+
+  current->next = new_next;
+  current->limit = new_limit;
+  current->level++;
+}
+
+
+GatheringHandleScope::~GatheringHandleScope() {
+  Isolate* isolate = info_->isolate();
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  HandleScopeImplementer::HiddenExtensions* extensions =
+      impl->HideExtensions(prev_limit_);
+  info_->RememberHiddenExtensions(extensions);
+
+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  current->next = prev_next_;
+  current->limit = prev_limit_;
+
+  impl->unset_last_block_before_compilation();
+  current->level--;
+}
+
+
 } }  // namespace v8::internal