Debugger: ScopeMirror has N^2 algorithm when building closure mirrors.

src/scopeinfo.cc

 // Copyright 2011 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 344 matching lines @@
     if (FunctionVariableField::decode(Flags()) == CONTEXT &&
         FunctionName() == name) {
       *mode = FunctionVariableMode::decode(Flags());
       return Smi::cast(get(FunctionNameEntryIndex() + 1))->value();
     }
   }
   return -1;
 }
 
 
+bool ScopeInfo::CopyContextLocalsToScopeObject(
+    Isolate* isolate,
+    Handle<Context> context,
+    Handle<JSObject> scope_object) {
+  // Fill all context locals to the context extension.
+  int start = ContextLocalNameEntriesIndex();
+  int end = start + ContextLocalCount();
+  for (int i = start; i < end; ++i) {
+    int context_index = Context::MIN_CONTEXT_SLOTS + i - start;
+    RETURN_IF_EMPTY_HANDLE_VALUE(
+        isolate,
+        SetProperty(isolate,
+                    scope_object,
+                    Handle<String>(String::cast(get(i))),
+                    Handle<Object>(context->get(context_index), isolate),
+                    ::NONE,
+                    kNonStrictMode),
+        false);
+  }
+  return true;
+}
+
+
 int ScopeInfo::ParameterEntriesIndex() {
   ASSERT(length() > 0);
   return kVariablePartIndex;
 }
 
 
 int ScopeInfo::StackLocalEntriesIndex() {
   return ParameterEntriesIndex() + ParameterCount();
 }
 
@@ skipping 152 matching lines @@
     } else {
       ASSERT(var->index() >= 0);
       info->set_index(i, var->index());
     }
   }
   ASSERT(i == info->length());
   return info;
 }
 
 } }  // namespace v8::internal