src/ic/handler-configuration.h

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_IC_HANDLER_CONFIGURATION_H_
#define V8_IC_HANDLER_CONFIGURATION_H_

#include "src/common/globals.h"
#include "src/handles/maybe-handles.h"
#include "src/objects/data-handler.h"
#include "src/objects/elements-kind.h"
#include "src/objects/field-index.h"
#include "src/objects/objects.h"
#include "src/utils/utils.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

class JSProxy;

// A set of bit fields representing Smi handlers for loads and a HeapObject
// that represents load handlers that can't be encoded in a Smi.
// TODO(ishell): move to load-handler.h
class LoadHandler final : public DataHandler {
 public:
  DECL_CAST(LoadHandler)

  DECL_PRINTER(LoadHandler)
  DECL_VERIFIER(LoadHandler)

  enum Kind {
    kElement,
    kIndexedString,
    kNormal,
    kGlobal,
    kField,
    kConstantFromPrototype,
    kAccessor,
    kNativeDataProperty,
    kApiGetter,
    kApiGetterHolderIsPrototype,
    kInterceptor,
    kSlow,
    kProxy,
    kNonExistent,
    kModuleExport
  };
  using KindBits = base::BitField<Kind, 0, 4>;

  // Defines whether access rights check should be done on receiver object.
  // Applicable to named property kinds only when loading value from prototype
  // chain. Ignored when loading from holder.
  using DoAccessCheckOnReceiverBits = KindBits::Next<bool, 1>;

  // Defines whether a lookup should be done on receiver object before
  // proceeding to the prototype chain. Applicable to named property kinds only
  // when loading value from prototype chain. Ignored when loading from holder.
  using LookupOnReceiverBits = DoAccessCheckOnReceiverBits::Next<bool, 1>;

  //
  // Encoding when KindBits contains kForConstants.
  //

  // Index of a value entry in the descriptor array.
  using DescriptorBits =
      LookupOnReceiverBits::Next<unsigned, kDescriptorIndexBitCount>;
  // Make sure we don't overflow the smi.
  STATIC_ASSERT(DescriptorBits::kLastUsedBit < kSmiValueSize);

  //
  // Encoding when KindBits contains kField.
  //
  using IsInobjectBits = LookupOnReceiverBits::Next<bool, 1>;
  using IsDoubleBits = IsInobjectBits::Next<bool, 1>;
  // +1 here is to cover all possible JSObject header sizes.
  using FieldIndexBits =
      IsDoubleBits::Next<unsigned, kDescriptorIndexBitCount + 1>;
  // Make sure we don't overflow the smi.
  STATIC_ASSERT(FieldIndexBits::kLastUsedBit < kSmiValueSize);

  //
  // Encoding when KindBits contains kElement or kIndexedString.
  //
  using AllowOutOfBoundsBits = LookupOnReceiverBits::Next<bool, 1>;

  //
  // Encoding when KindBits contains kElement.
  //
  using IsJsArrayBits = AllowOutOfBoundsBits::Next<bool, 1>;
  using ConvertHoleBits = IsJsArrayBits::Next<bool, 1>;
  using ElementsKindBits = ConvertHoleBits::Next<ElementsKind, 8>;
  // Make sure we don't overflow the smi.
  STATIC_ASSERT(ElementsKindBits::kLastUsedBit < kSmiValueSize);

  //
  // Encoding when KindBits contains kModuleExport.
  //
  using ExportsIndexBits = LookupOnReceiverBits::Next<
      unsigned, kSmiValueSize - LookupOnReceiverBits::kLastUsedBit - 1>;

  // Decodes kind from Smi-handler.
  static inline Kind GetHandlerKind(Smi smi_handler);

  // Creates a Smi-handler for loading a property from a slow object.
  static inline Handle<Smi> LoadNormal(Isolate* isolate);

  // Creates a Smi-handler for loading a property from a global object.
  static inline Handle<Smi> LoadGlobal(Isolate* isolate);

  // Creates a Smi-handler for loading a property from an object with an
  // interceptor.
  static inline Handle<Smi> LoadInterceptor(Isolate* isolate);

  // Creates a Smi-handler for loading a property from a object.
  static inline Handle<Smi> LoadSlow(Isolate* isolate);

  // Creates a Smi-handler for loading a field from fast object.
  static inline Handle<Smi> LoadField(Isolate* isolate, FieldIndex field_index);

  // Creates a Smi-handler for loading a cached constant from fast
  // prototype object.
  static inline Handle<Smi> LoadConstantFromPrototype(Isolate* isolate);

  // Creates a Smi-handler for calling a getter on a fast object.
  static inline Handle<Smi> LoadAccessor(Isolate* isolate, int descriptor);

  // Creates a Smi-handler for calling a getter on a proxy.
  static inline Handle<Smi> LoadProxy(Isolate* isolate);

  // Creates a Smi-handler for loading a native data property from fast object.
  static inline Handle<Smi> LoadNativeDataProperty(Isolate* isolate,
                                                   int descriptor);

  // Creates a Smi-handler for calling a native getter on a fast object.
  static inline Handle<Smi> LoadApiGetter(Isolate* isolate,
                                          bool holder_is_receiver);

  // Creates a Smi-handler for loading a Module export.
  // |index| is the index to the "value" slot in the Module's "exports"
  // dictionary.
  static inline Handle<Smi> LoadModuleExport(Isolate* isolate, int index);

  // Creates a data handler that represents a load of a non-existent property.
  // {holder} is the object from which the property is loaded. If no holder is
  // needed (e.g., for "nonexistent"), null_value() may be passed in.
  static Handle<Object> LoadFullChain(Isolate* isolate,
                                      Handle<Map> receiver_map,
                                      const MaybeObjectHandle& holder,
                                      Handle<Smi> smi_handler);

  // Creates a data handler that represents a prototype chain check followed
  // by given Smi-handler that encoded a load from the holder.
  // Can be used only if GetPrototypeCheckCount() returns non negative value.
  static Handle<Object> LoadFromPrototype(
      Isolate* isolate, Handle<Map> receiver_map, Handle<JSReceiver> holder,
      Handle<Smi> smi_handler,
      MaybeObjectHandle maybe_data1 = MaybeObjectHandle(),
      MaybeObjectHandle maybe_data2 = MaybeObjectHandle());

  // Creates a Smi-handler for loading a non-existent property. Works only as
  // a part of prototype chain check.
  static inline Handle<Smi> LoadNonExistent(Isolate* isolate);

  // Creates a Smi-handler for loading an element.
  static inline Handle<Smi> LoadElement(Isolate* isolate,
                                        ElementsKind elements_kind,
                                        bool convert_hole_to_undefined,
                                        bool is_js_array,
                                        KeyedAccessLoadMode load_mode);

  // Creates a Smi-handler for loading from a String.
  static inline Handle<Smi> LoadIndexedString(Isolate* isolate,
                                              KeyedAccessLoadMode load_mode);

  // Decodes the KeyedAccessLoadMode from a {handler}.
  static KeyedAccessLoadMode GetKeyedAccessLoadMode(MaybeObject handler);

  OBJECT_CONSTRUCTORS(LoadHandler, DataHandler);
};

// A set of bit fields representing Smi handlers for stores and a HeapObject
// that represents store handlers that can't be encoded in a Smi.
// TODO(ishell): move to store-handler.h
class StoreHandler final : public DataHandler {
 public:
  DECL_CAST(StoreHandler)

  DECL_PRINTER(StoreHandler)
  DECL_VERIFIER(StoreHandler)

  enum Kind {
    kElement,
    kField,
    kConstField,
    kAccessor,
    kNativeDataProperty,
    kApiSetter,
    kApiSetterHolderIsPrototype,
    kGlobalProxy,
    kNormal,
    kInterceptor,
    kSlow,
    kProxy,
    kKindsNumber  // Keep last
  };
  using KindBits = base::BitField<Kind, 0, 4>;

  // Applicable to kGlobalProxy, kProxy kinds.

  // Defines whether access rights check should be done on receiver object.
  using DoAccessCheckOnReceiverBits = KindBits::Next<bool, 1>;

  // Defines whether a lookup should be done on receiver object before
  // proceeding to the prototype chain. Applicable to named property kinds only
  // when storing through prototype chain. Ignored when storing to holder.
  using LookupOnReceiverBits = DoAccessCheckOnReceiverBits::Next<bool, 1>;

  // Applicable to kField, kTransitionToField and kTransitionToConstant
  // kinds.

  // Index of a value entry in the descriptor array.
  using DescriptorBits =
      LookupOnReceiverBits::Next<unsigned, kDescriptorIndexBitCount>;

  //
  // Encodes the bits when StoreSlow contains KeyedAccessStoreMode.
  //
  using KeyedAccessStoreModeBits =
      DescriptorBits::Next<KeyedAccessStoreMode, 2>;

  //
  // Encoding when KindBits contains kTransitionToConstant.
  //

  // Make sure we don't overflow the smi.
  STATIC_ASSERT(DescriptorBits::kLastUsedBit < kSmiValueSize);

  //
  // Encoding when KindBits contains kField or kTransitionToField.
  //
  using IsInobjectBits = DescriptorBits::Next<bool, 1>;
  using RepresentationBits = IsInobjectBits::Next<Representation::Kind, 3>;
  // +1 here is to cover all possible JSObject header sizes.
  using FieldIndexBits =
      RepresentationBits::Next<unsigned, kDescriptorIndexBitCount + 1>;
  // Make sure we don't overflow the smi.
  STATIC_ASSERT(FieldIndexBits::kLastUsedBit < kSmiValueSize);

  // Creates a Smi-handler for storing a field to fast object.
  static inline Handle<Smi> StoreField(Isolate* isolate, int descriptor,
                                       FieldIndex field_index,
                                       PropertyConstness constness,
                                       Representation representation);

  static MaybeObjectHandle StoreTransition(Isolate* isolate,
                                           Handle<Map> transition_map);

  // Creates a Smi-handler for storing a native data property on a fast object.
  static inline Handle<Smi> StoreNativeDataProperty(Isolate* isolate,
                                                    int descriptor);

  // Creates a Smi-handler for calling a setter on a fast object.
  static inline Handle<Smi> StoreAccessor(Isolate* isolate, int descriptor);

  // Creates a Smi-handler for calling a native setter on a fast object.
  static inline Handle<Smi> StoreApiSetter(Isolate* isolate,
                                           bool holder_is_receiver);

  static Handle<Object> StoreThroughPrototype(
      Isolate* isolate, Handle<Map> receiver_map, Handle<JSReceiver> holder,
      Handle<Smi> smi_handler,
      MaybeObjectHandle maybe_data1 = MaybeObjectHandle(),
      MaybeObjectHandle maybe_data2 = MaybeObjectHandle());

  static Handle<Object> StoreElementTransition(
      Isolate* isolate, Handle<Map> receiver_map, Handle<Map> transition,
      KeyedAccessStoreMode store_mode,
      MaybeHandle<Object> prev_validity_cell = MaybeHandle<Object>());

  static Handle<Object> StoreProxy(Isolate* isolate, Handle<Map> receiver_map,
                                   Handle<JSProxy> proxy,
                                   Handle<JSReceiver> receiver);

  // Creates a handler for storing a property to the property cell of a global
  // object.
  static MaybeObjectHandle StoreGlobal(Handle<PropertyCell> cell);

  // Creates a Smi-handler for storing a property to a global proxy object.
  static inline Handle<Smi> StoreGlobalProxy(Isolate* isolate);

  // Creates a Smi-handler for storing a property to a slow object.
  static inline Handle<Smi> StoreNormal(Isolate* isolate);

  // Creates a Smi-handler for storing a property to an interceptor.
  static inline Handle<Smi> StoreInterceptor(Isolate* isolate);

  // Creates a Smi-handler for storing a property.
  static inline Handle<Smi> StoreSlow(
      Isolate* isolate, KeyedAccessStoreMode store_mode = STANDARD_STORE);

  // Creates a Smi-handler for storing a property on a proxy.
  static inline Handle<Smi> StoreProxy(Isolate* isolate);

  // Decodes the KeyedAccessStoreMode from a {handler}.
  static KeyedAccessStoreMode GetKeyedAccessStoreMode(MaybeObject handler);

 private:
  static inline Handle<Smi> StoreField(Isolate* isolate, Kind kind,
                                       int descriptor, FieldIndex field_index,
                                       Representation representation);

  OBJECT_CONSTRUCTORS(StoreHandler, DataHandler);
};

}  // namespace internal
}  // namespace v8

#include "src/objects/object-macros-undef.h"

#endif  // V8_IC_HANDLER_CONFIGURATION_H_