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

src/runtime.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 10748 matching lines @@
     receiver =
         isolate->factory()->ToObject(receiver, calling_frames_native_context);
   }
   details->set(kFrameDetailsReceiverIndex, *receiver);
 
   ASSERT_EQ(details_size, details_index);
   return *isolate->factory()->NewJSArrayWithElements(details);
 }
 
 
-// Copy all the context locals into an object used to materialize a scope.
-static bool CopyContextLocalsToScopeObject(
-    Isolate* isolate,
-    Handle<ScopeInfo> scope_info,
-    Handle<Context> context,
-    Handle<JSObject> scope_object) {
-  // Fill all context locals to the context extension.
-  for (int i = 0; i < scope_info->ContextLocalCount(); i++) {
-    VariableMode mode;
-    InitializationFlag init_flag;
-    int context_index = scope_info->ContextSlotIndex(
-        scope_info->ContextLocalName(i), &mode, &init_flag);
-
-    RETURN_IF_EMPTY_HANDLE_VALUE(
-        isolate,
-        SetProperty(isolate,
-                    scope_object,
-                    Handle<String>(scope_info->ContextLocalName(i)),
-                    Handle<Object>(context->get(context_index), isolate),
-                    NONE,
-                    kNonStrictMode),
-        false);
-  }
-
-  return true;
-}
-
-
 // Create a plain JSObject which materializes the local scope for the specified
 // frame.
 static Handle<JSObject> MaterializeLocalScopeWithFrameInspector(
     Isolate* isolate,
     JavaScriptFrame* frame,
     FrameInspector* frame_inspector) {
   Handle<JSFunction> function(JSFunction::cast(frame_inspector->GetFunction()));
   Handle<SharedFunctionInfo> shared(function->shared());
   Handle<ScopeInfo> scope_info(shared->scope_info());
 
@@ skipping 29 matching lines @@
                     Handle<Object>(frame_inspector->GetExpression(i)),
                     NONE,
                     kNonStrictMode),
         Handle<JSObject>());
   }
 
   if (scope_info->HasContext()) {
     // Third fill all context locals.
     Handle<Context> frame_context(Context::cast(frame->context()));
     Handle<Context> function_context(frame_context->declaration_context());
-    if (!CopyContextLocalsToScopeObject(
-            isolate, scope_info, function_context, local_scope)) {
+    if (!scope_info->CopyContextLocalsToScopeObject(
+            isolate, function_context, local_scope)) {
       return Handle<JSObject>();
     }
 
     // Finally copy any properties from the function context extension.
     // These will be variables introduced by eval.
     if (function_context->closure() == *function) {
       if (function_context->has_extension() &&
           !function_context->IsNativeContext()) {
         Handle<JSObject> ext(JSObject::cast(function_context->extension()));
         bool threw = false;
@@ skipping 131 matching lines @@
 
   Handle<SharedFunctionInfo> shared(context->closure()->shared());
   Handle<ScopeInfo> scope_info(shared->scope_info());
 
   // Allocate and initialize a JSObject with all the content of this function
   // closure.
   Handle<JSObject> closure_scope =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   // Fill all context locals to the context extension.
-  if (!CopyContextLocalsToScopeObject(
-          isolate, scope_info, context, closure_scope)) {
+  if (!scope_info->CopyContextLocalsToScopeObject(
+          isolate, context, closure_scope)) {
     return Handle<JSObject>();
   }
 
   // Finally copy any properties from the function context extension. This will
   // be variables introduced by eval.
   if (context->has_extension()) {
     Handle<JSObject> ext(JSObject::cast(context->extension()));
     bool threw = false;
     Handle<FixedArray> keys =
         GetKeysInFixedArrayFor(ext, INCLUDE_PROTOS, &threw);
@@ skipping 98 matching lines @@
     Handle<Context> context) {
   ASSERT(context->IsBlockContext());
   Handle<ScopeInfo> scope_info(ScopeInfo::cast(context->extension()));
 
   // Allocate and initialize a JSObject with all the arguments, stack locals
   // heap locals and extension properties of the debugged function.
   Handle<JSObject> block_scope =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   // Fill all context locals.
-  if (!CopyContextLocalsToScopeObject(
-          isolate, scope_info, context, block_scope)) {
+  if (!scope_info->CopyContextLocalsToScopeObject(
+          isolate, context, block_scope)) {
     return Handle<JSObject>();
   }
 
   return block_scope;
 }
 
 
 // Create a plain JSObject which materializes the module scope for the specified
 // module context.
 static Handle<JSObject> MaterializeModuleScope(
     Isolate* isolate,
     Handle<Context> context) {
   ASSERT(context->IsModuleContext());
   Handle<ScopeInfo> scope_info(ScopeInfo::cast(context->extension()));
 
   // Allocate and initialize a JSObject with all the members of the debugged
   // module.
   Handle<JSObject> module_scope =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   // Fill all context locals.
-  if (!CopyContextLocalsToScopeObject(
-          isolate, scope_info, context, module_scope)) {
+  if (!scope_info->CopyContextLocalsToScopeObject(
+          isolate, context, module_scope)) {
     return Handle<JSObject>();
   }
 
   return module_scope;
 }
 
 
 // Iterate over the actual scopes visible from a stack frame or from a closure.
 // The iteration proceeds from the innermost visible nested scope outwards.
 // All scopes are backed by an actual context except the local scope,
@@ skipping 2379 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal