A MessageObject is a purely internal object to hold information about

src/objects-inl.h

 // Copyright 2010 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 390 matching lines @@
 
 
 bool MaybeObject::IsRetryAfterGC() {
   return HAS_FAILURE_TAG(this)
     && Failure::cast(this)->type() == Failure::RETRY_AFTER_GC;
 }
 
 
 bool MaybeObject::IsOutOfMemory() {
   return HAS_FAILURE_TAG(this)
-    && Failure::cast(this)->IsOutOfMemoryException();
+      && Failure::cast(this)->IsOutOfMemoryException();
 }
 
 
 bool MaybeObject::IsException() {
   return this == Failure::Exception();
 }
 
 
 bool MaybeObject::IsTheHole() {
   return this == Heap::the_hole_value();
 }
 
 
 Failure* Failure::cast(MaybeObject* obj) {
   ASSERT(HAS_FAILURE_TAG(obj));
   return reinterpret_cast<Failure*>(obj);
 }
 
 
 bool Object::IsJSObject() {
   return IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() >= FIRST_JS_OBJECT_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() >= FIRST_JS_OBJECT_TYPE;
 }
 
 
 bool Object::IsJSContextExtensionObject() {
   return IsHeapObject()
-    && (HeapObject::cast(this)->map()->instance_type() ==
-        JS_CONTEXT_EXTENSION_OBJECT_TYPE);
+      && (HeapObject::cast(this)->map()->instance_type() ==
+          JS_CONTEXT_EXTENSION_OBJECT_TYPE);
 }
 
 
 bool Object::IsMap() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == MAP_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == MAP_TYPE;
 }
 
 
 bool Object::IsFixedArray() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == FIXED_ARRAY_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == FIXED_ARRAY_TYPE;
 }
 
 
 bool Object::IsDescriptorArray() {
   return IsFixedArray();
 }
 
 
 bool Object::IsDeoptimizationInputData() {
   // Must be a fixed array.
@@ skipping 25 matching lines @@
 bool Object::IsContext() {
   return Object::IsHeapObject()
     && (HeapObject::cast(this)->map() == Heap::context_map() ||
         HeapObject::cast(this)->map() == Heap::catch_context_map() ||
         HeapObject::cast(this)->map() == Heap::global_context_map());
 }
 
 
 bool Object::IsCatchContext() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map() == Heap::catch_context_map();
+      && HeapObject::cast(this)->map() == Heap::catch_context_map();
 }
 
 
 bool Object::IsGlobalContext() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map() == Heap::global_context_map();
+      && HeapObject::cast(this)->map() == Heap::global_context_map();
 }
 
 
 bool Object::IsJSFunction() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == JS_FUNCTION_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == JS_FUNCTION_TYPE;
 }
 
 
 template <> inline bool Is<JSFunction>(Object* obj) {
   return obj->IsJSFunction();
 }
 
 
 bool Object::IsCode() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == CODE_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == CODE_TYPE;
 }
 
 
 bool Object::IsOddball() {
   return Object::IsHeapObject()
     && HeapObject::cast(this)->map()->instance_type() == ODDBALL_TYPE;
 }
 
 
 bool Object::IsJSGlobalPropertyCell() {
   return Object::IsHeapObject()
       && HeapObject::cast(this)->map()->instance_type()
       == JS_GLOBAL_PROPERTY_CELL_TYPE;
 }
 
 
 bool Object::IsSharedFunctionInfo() {
   return Object::IsHeapObject() &&
       (HeapObject::cast(this)->map()->instance_type() ==
        SHARED_FUNCTION_INFO_TYPE);
 }
 
 
 bool Object::IsJSValue() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == JS_VALUE_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == JS_VALUE_TYPE;
 }
 
 
+bool Object::IsJSMessageObject() {
+  return Object::IsHeapObject()
+      && (HeapObject::cast(this)->map()->instance_type() ==
+          JS_MESSAGE_OBJECT_TYPE);
+}
+
+
 bool Object::IsStringWrapper() {
   return IsJSValue() && JSValue::cast(this)->value()->IsString();
 }
 
 
 bool Object::IsProxy() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == PROXY_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == PROXY_TYPE;
 }
 
 
 bool Object::IsBoolean() {
   return IsTrue() || IsFalse();
 }
 
 
 bool Object::IsJSArray() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == JS_ARRAY_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == JS_ARRAY_TYPE;
 }
 
 
 bool Object::IsJSRegExp() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() == JS_REGEXP_TYPE;
+      && HeapObject::cast(this)->map()->instance_type() == JS_REGEXP_TYPE;
 }
 
 
 template <> inline bool Is<JSArray>(Object* obj) {
   return obj->IsJSArray();
 }
 
 
 bool Object::IsHashTable() {
   return Object::IsHeapObject()
-    && HeapObject::cast(this)->map() == Heap::hash_table_map();
+      && HeapObject::cast(this)->map() == Heap::hash_table_map();
 }
 
 
 bool Object::IsDictionary() {
   return IsHashTable() && this != Heap::symbol_table();
 }
 
 
 bool Object::IsSymbolTable() {
   return IsHashTable() && this == Heap::raw_unchecked_symbol_table();
@@ skipping 681 matching lines @@
     case JS_FUNCTION_TYPE:
       return JSFunction::kSize;
     case JS_VALUE_TYPE:
       return JSValue::kSize;
     case JS_ARRAY_TYPE:
       return JSValue::kSize;
     case JS_REGEXP_TYPE:
       return JSValue::kSize;
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
       return JSObject::kHeaderSize;
+    case JS_MESSAGE_OBJECT_TYPE:
+      return JSMessageObject::kSize;
     default:
       UNREACHABLE();
       return 0;
   }
 }
 
 
 int JSObject::GetInternalFieldCount() {
   ASSERT(1 << kPointerSizeLog2 == kPointerSize);
   // Make sure to adjust for the number of in-object properties. These
@@ skipping 1984 matching lines @@
 ACCESSORS(JSValue, value, Object, kValueOffset)
 
 
 JSValue* JSValue::cast(Object* obj) {
   ASSERT(obj->IsJSValue());
   ASSERT(HeapObject::cast(obj)->Size() == JSValue::kSize);
   return reinterpret_cast<JSValue*>(obj);
 }
 
 
+ACCESSORS(JSMessageObject, type, String, kTypeOffset)
+ACCESSORS(JSMessageObject, arguments, JSArray, kArgumentsOffset)
+ACCESSORS(JSMessageObject, script, Object, kScriptOffset)
+ACCESSORS(JSMessageObject, stack_trace, Object, kStackTraceOffset)
+ACCESSORS(JSMessageObject, stack_frames, Object, kStackFramesOffset)
+SMI_ACCESSORS(JSMessageObject, start_position, kStartPositionOffset)
+SMI_ACCESSORS(JSMessageObject, end_position, kEndPositionOffset)
+
+
+JSMessageObject* JSMessageObject::cast(Object* obj) {
+  ASSERT(obj->IsJSMessageObject());
+  ASSERT(HeapObject::cast(obj)->Size() == JSMessageObject::kSize);
+  return reinterpret_cast<JSMessageObject*>(obj);
+}
+
+
 INT_ACCESSORS(Code, instruction_size, kInstructionSizeOffset)
 ACCESSORS(Code, relocation_info, ByteArray, kRelocationInfoOffset)
 ACCESSORS(Code, deoptimization_data, FixedArray, kDeoptimizationDataOffset)
 
 
 byte* Code::instruction_start()  {
   return FIELD_ADDR(this, kHeaderSize);
 }
 
 
@@ skipping 574 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_