Introduce Runtime_GetAllScopesDetails to get all scopes at once for a frame.

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 12223 matching lines @@
   }
   return *array;
 }
 
 
 static const int kScopeDetailsTypeIndex = 0;
 static const int kScopeDetailsObjectIndex = 1;
 static const int kScopeDetailsSize = 2;
 
 
-static MaybeObject* MaterializeScopeDetails(Isolate* isolate,
+static Handle<JSObject> MaterializeScopeDetails(Isolate* isolate,
     ScopeIterator* it) {
   // Calculate the size of the result.
   int details_size = kScopeDetailsSize;
   Handle<FixedArray> details = isolate->factory()->NewFixedArray(details_size);
 
   // Fill in scope details.
   details->set(kScopeDetailsTypeIndex, Smi::FromInt(it->Type()));
   Handle<JSObject> scope_object = it->ScopeObject();
-  RETURN_IF_EMPTY_HANDLE(isolate, scope_object);
+  RETURN_IF_EMPTY_HANDLE_VALUE(isolate, scope_object, Handle<JSObject>());
   details->set(kScopeDetailsObjectIndex, *scope_object);
 
-  return *isolate->factory()->NewJSArrayWithElements(details);
+  return isolate->factory()->NewJSArrayWithElements(details);
 }
 
 
 // Return an array with scope details
 // args[0]: number: break id
 // args[1]: number: frame index
 // args[2]: number: inlined frame index
 // args[3]: number: scope index
 //
 // The array returned contains the following information:
@@ skipping 20 matching lines @@
 
   // Find the requested scope.
   int n = 0;
   ScopeIterator it(isolate, frame, inlined_jsframe_index);
   for (; !it.Done() && n < index; it.Next()) {
     n++;
   }
   if (it.Done()) {
     return isolate->heap()->undefined_value();
   }
-  return MaterializeScopeDetails(isolate, &it);
+  Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
+  RETURN_IF_EMPTY_HANDLE(isolate, details);
+  return *details;
 }
 
 
+// Return an array of scope details
+// args[0]: number: break id
+// args[1]: number: frame index
+// args[2]: number: inlined frame index
+//
+// The array returned contains arrays with the following information:
+// 0: Scope type
+// 1: Scope object
+RUNTIME_FUNCTION(MaybeObject*, Runtime_GetAllScopesDetails) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 3);
+
+  // Check arguments.
+  Object* check;
+  { MaybeObject* maybe_check = Runtime_CheckExecutionState(
+      RUNTIME_ARGUMENTS(isolate, args));
+    if (!maybe_check->ToObject(&check)) return maybe_check;
+  }
+  CONVERT_SMI_ARG_CHECKED(wrapped_id, 1);
+  CONVERT_NUMBER_CHECKED(int, inlined_jsframe_index, Int32, args[2]);
+
+  // Get the frame where the debugging is performed.
+  StackFrame::Id id = UnwrapFrameId(wrapped_id);
+  JavaScriptFrameIterator frame_it(isolate, id);
+  JavaScriptFrame* frame = frame_it.frame();
+
+  List<Handle<JSObject> > result(4);
+  ScopeIterator it(isolate, frame, inlined_jsframe_index);
+  for (; !it.Done(); it.Next()) {
+    Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
+    RETURN_IF_EMPTY_HANDLE(isolate, details);
+    result.Add(details);
+  }
+
+  Handle<FixedArray> array = isolate->factory()->NewFixedArray(result.length());
+  for (int i = 0; i < result.length(); ++i) {
+    array->set(i, *result[i]);
+  }
+  return *isolate->factory()->NewJSArrayWithElements(array);
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetFunctionScopeCount) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
 
   // Check arguments.
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
 
   // Count the visible scopes.
   int n = 0;
   for (ScopeIterator it(isolate, fun); !it.Done(); it.Next()) {
@@ skipping 15 matching lines @@
   // Find the requested scope.
   int n = 0;
   ScopeIterator it(isolate, fun);
   for (; !it.Done() && n < index; it.Next()) {
     n++;
   }
   if (it.Done()) {
     return isolate->heap()->undefined_value();
   }
 
-  return MaterializeScopeDetails(isolate, &it);
+  Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
+  RETURN_IF_EMPTY_HANDLE(isolate, details);
+  return *details;
 }
 
 
 static bool SetScopeVariableValue(ScopeIterator* it, int index,
                                   Handle<String> variable_name,
                                   Handle<Object> new_value) {
   for (int n = 0; !it->Done() && n < index; it->Next()) {
     n++;
   }
   if (it->Done()) {
@@ skipping 2618 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