runtime.cc.svn-base

Google浏览器V8内核代码

  CONVERT_DOUBLE_CHECKED(f_number, args[1]);
  int f = FastD2I(f_number);
  RUNTIME_ASSERT(f >= -1 && f <= 20);
  char* str = DoubleToExponentialCString(value, f);
  Object* res = Heap::AllocateStringFromAscii(CStrVector(str));
  DeleteArray(str);
  return res;
}


static Object* Runtime_NumberToPrecision(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_DOUBLE_CHECKED(value, args[0]);
  if (isnan(value)) {
    return Heap::AllocateStringFromAscii(CStrVector("NaN"));
  }
  if (isinf(value)) {
    if (value < 0) {
      return Heap::AllocateStringFromAscii(CStrVector("-Infinity"));
    }
    return Heap::AllocateStringFromAscii(CStrVector("Infinity"));
  }
  CONVERT_DOUBLE_CHECKED(f_number, args[1]);
  int f = FastD2I(f_number);
  RUNTIME_ASSERT(f >= 1 && f <= 21);
  char* str = DoubleToPrecisionCString(value, f);
  Object* res = Heap::AllocateStringFromAscii(CStrVector(str));
  DeleteArray(str);
  return res;
}


// Returns a single character string where first character equals
// string->Get(index).
static Handle<Object> GetCharAt(Handle<String> string, uint32_t index) {
  if (index < static_cast<uint32_t>(string->length())) {
    string->TryFlatten();
    return LookupSingleCharacterStringFromCode(string->Get(index));
  }
  return Execution::CharAt(string, index);
}


Object* Runtime::GetElementOrCharAt(Handle<Object> object, uint32_t index) {
  // Handle [] indexing on Strings
  if (object->IsString()) {
    Handle<Object> result = GetCharAt(Handle<String>::cast(object), index);
    if (!result->IsUndefined()) return *result;
  }

  // Handle [] indexing on String objects
  if (object->IsStringObjectWithCharacterAt(index)) {
    Handle<JSValue> js_value = Handle<JSValue>::cast(object);
    Handle<Object> result =
        GetCharAt(Handle<String>(String::cast(js_value->value())), index);
    if (!result->IsUndefined()) return *result;
  }

  if (object->IsString() || object->IsNumber() || object->IsBoolean()) {
    Handle<Object> prototype = GetPrototype(object);
    return prototype->GetElement(index);
  }

  return object->GetElement(index);
}


Object* Runtime::GetObjectProperty(Handle<Object> object, Handle<Object> key) {
  HandleScope scope;

  if (object->IsUndefined() || object->IsNull()) {
    Handle<Object> args[2] = { key, object };
    Handle<Object> error =
        Factory::NewTypeError("non_object_property_load",
                              HandleVector(args, 2));
    return Top::Throw(*error);
  }

  // Check if the given key is an array index.
  uint32_t index;
  if (Array::IndexFromObject(*key, &index)) {
    return GetElementOrCharAt(object, index);
  }

  // Convert the key to a string - possibly by calling back into JavaScript.
  Handle<String> name;
  if (key->IsString()) {
    name = Handle<String>::cast(key);
  } else {
    bool has_pending_exception = false;
    Handle<Object> converted =
        Execution::ToString(key, &has_pending_exception);
    if (has_pending_exception) return Failure::Exception();
    name = Handle<String>::cast(converted);
  }

  // Check if the name is trivially convertable to an index and get
  // the element if so.
  if (name->AsArrayIndex(&index)) {
    return GetElementOrCharAt(object, index);
  } else {
    PropertyAttributes attr;
    return object->GetProperty(*name, &attr);
  }
}


static Object* Runtime_GetProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  Handle<Object> object = args.at<Object>(0);
  Handle<Object> key = args.at<Object>(1);

  return Runtime::GetObjectProperty(object, key);
}


Object* Runtime::SetObjectProperty(Handle<Object> object,
                                   Handle<Object> key,
                                   Handle<Object> value,
                                   PropertyAttributes attr) {
  HandleScope scope;

  if (object->IsUndefined() || object->IsNull()) {
    Handle<Object> args[2] = { key, object };
    Handle<Object> error =
        Factory::NewTypeError("non_object_property_store",
                              HandleVector(args, 2));
    return Top::Throw(*error);
  }

  // If the object isn't a JavaScript object, we ignore the store.
  if (!object->IsJSObject()) return *value;

  Handle<JSObject> js_object = Handle<JSObject>::cast(object);

  // Check if the given key is an array index.
  uint32_t index;
  if (Array::IndexFromObject(*key, &index)) {
    ASSERT(attr == NONE);

    // In Firefox/SpiderMonkey, Safari and Opera you can access the characters
    // of a string using [] notation.  We need to support this too in
    // JavaScript.
    // In the case of a String object we just need to redirect the assignment to
    // the underlying string if the index is in range.  Since the underlying
    // string does nothing with the assignment then we can ignore such
    // assignments.
    if (js_object->IsStringObjectWithCharacterAt(index)) {
      return *value;
    }

    Handle<Object> result = SetElement(js_object, index, value);
    if (result.is_null()) return Failure::Exception();
    return *value;
  }

  if (key->IsString()) {
    Handle<Object> result;
    if (Handle<String>::cast(key)->AsArrayIndex(&index)) {
      ASSERT(attr == NONE);
      result = SetElement(js_object, index, value);
    } else {
      Handle<String> key_string = Handle<String>::cast(key);
      key_string->TryFlatten();
      result = SetProperty(js_object, key_string, value, attr);
    }
    if (result.is_null()) return Failure::Exception();
    return *value;
  }

  // Call-back into JavaScript to convert the key to a string.
  bool has_pending_exception = false;
  Handle<Object> converted = Execution::ToString(key, &has_pending_exception);
  if (has_pending_exception) return Failure::Exception();
  Handle<String> name = Handle<String>::cast(converted);

  if (name->AsArrayIndex(&index)) {
    ASSERT(attr == NONE);
    return js_object->SetElement(index, *value);
  } else {
    return js_object->SetProperty(*name, *value, attr);
  }
}


static Object* Runtime_AddProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 4);

  CONVERT_CHECKED(JSObject, object, args[0]);
  CONVERT_CHECKED(String, name, args[1]);
  RUNTIME_ASSERT(!object->HasLocalProperty(name));
  CONVERT_CHECKED(Smi, attr_obj, args[3]);

  int attr = attr_obj->value();
  RUNTIME_ASSERT((attr & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
  PropertyAttributes attributes = static_cast<PropertyAttributes>(attr);

  return object->AddProperty(name, args[2], attributes);
}


static Object* Runtime_SetProperty(Arguments args) {
  NoHandleAllocation ha;
  RUNTIME_ASSERT(args.length() == 3 || args.length() == 4);

  Handle<Object> object = args.at<Object>(0);
  Handle<Object> key = args.at<Object>(1);
  Handle<Object> value = args.at<Object>(2);

  // Compute attributes.
  PropertyAttributes attributes = NONE;
  if (args.length() == 4) {
    CONVERT_CHECKED(Smi, value_obj, args[3]);
    int value = value_obj->value();
    // Only attribute bits should be set.
    ASSERT((value & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
    attributes = static_cast<PropertyAttributes>(value);
  }
  return Runtime::SetObjectProperty(object, key, value, attributes);
}


// Set a local property, even if it is READ_ONLY.  If the property does not
// exist, it will be added with attributes NONE.
static Object* Runtime_IgnoreAttributesAndSetProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 3);

  CONVERT_CHECKED(JSObject, object, args[0]);
  CONVERT_CHECKED(String, name, args[1]);

  return object->IgnoreAttributesAndSetLocalProperty(name, args[2]);
}


static Object* Runtime_DeleteProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSObject, object, args[0]);
  CONVERT_CHECKED(String, key, args[1]);
  return object->DeleteProperty(key);
}


static Object* Runtime_HasLocalProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);
  CONVERT_CHECKED(String, key, args[1]);

  // Only JS objects can have properties.
  if (args[0]->IsJSObject()) {
    JSObject* object = JSObject::cast(args[0]);
    if (object->HasLocalProperty(key)) return Heap::true_value();
  } else if (args[0]->IsString()) {
    // Well, there is one exception:  Handle [] on strings.
    uint32_t index;
    if (key->AsArrayIndex(&index)) {
      String* string = String::cast(args[0]);
      if (index < static_cast<uint32_t>(string->length()))
        return Heap::true_value();
    }
  }
  return Heap::false_value();
}


static Object* Runtime_HasProperty(Arguments args) {
  NoHandleAllocation na;
  ASSERT(args.length() == 2);

  // Only JS objects can have properties.
  if (args[0]->IsJSObject()) {
    JSObject* object = JSObject::cast(args[0]);
    CONVERT_CHECKED(String, key, args[1]);
    if (object->HasProperty(key)) return Heap::true_value();
  }
  return Heap::false_value();
}


static Object* Runtime_HasElement(Arguments args) {
  NoHandleAllocation na;
  ASSERT(args.length() == 2);

  // Only JS objects can have elements.
  if (args[0]->IsJSObject()) {
    JSObject* object = JSObject::cast(args[0]);
    CONVERT_CHECKED(Smi, index_obj, args[1]);
    uint32_t index = index_obj->value();
    if (object->HasElement(index)) return Heap::true_value();
  }
  return Heap::false_value();
}


static Object* Runtime_IsPropertyEnumerable(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSObject, object, args[0]);
  CONVERT_CHECKED(String, key, args[1]);

  uint32_t index;
  if (key->AsArrayIndex(&index)) {
    return Heap::ToBoolean(object->HasElement(index));
  }

  LookupResult result;
  object->LocalLookup(key, &result);
  if (!result.IsProperty()) return Heap::false_value();
  return Heap::ToBoolean(!result.IsDontEnum());
}


static Object* Runtime_GetPropertyNames(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSObject, raw_object, args[0]);
  Handle<JSObject> object(raw_object);
  return *GetKeysFor(object);
}


// Returns either a FixedArray as Runtime_GetPropertyNames,
// or, if the given object has an enum cache that contains
// all enumerable properties of the object and its prototypes
// have none, the map of the object. This is used to speed up
// the check for deletions during a for-in.
static Object* Runtime_GetPropertyNamesFast(Arguments args) {
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSObject, raw_object, args[0]);

  if (raw_object->IsSimpleEnum()) return raw_object->map();

  HandleScope scope;
  Handle<JSObject> object(raw_object);
  Handle<FixedArray> content = GetKeysInFixedArrayFor(object);

  // Test again, since cache may have been built by preceding call.
  if (object->IsSimpleEnum()) return object->map();

  return *content;
}


static Object* Runtime_GetArgumentsProperty(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 1);

  // Compute the frame holding the arguments.
  JavaScriptFrameIterator it;
  it.AdvanceToArgumentsFrame();
  JavaScriptFrame* frame = it.frame();

  // Get the actual number of provided arguments.
  const uint32_t n = frame->GetProvidedParametersCount();

  // Try to convert the key to an index. If successful and within
  // index return the the argument from the frame.
  uint32_t index;
  if (Array::IndexFromObject(args[0], &index) && index < n) {
    return frame->GetParameter(index);
  }

  // Convert the key to a string.
  HandleScope scope;
  bool exception = false;
  Handle<Object> converted =
      Execution::ToString(args.at<Object>(0), &exception);
  if (exception) return Failure::Exception();
  Handle<String> key = Handle<String>::cast(converted);

  // Try to convert the string key into an array index.
  if (key->AsArrayIndex(&index)) {
    if (index < n) {
      return frame->GetParameter(index);
    } else {
      return Top::initial_object_prototype()->GetElement(index);
    }
  }

  // Handle special arguments properties.
  if (key->Equals(Heap::length_symbol())) return Smi::FromInt(n);
  if (key->Equals(Heap::callee_symbol())) return frame->function();

  // Lookup in the initial Object.prototype object.