Use an enum for indicating the component of an AccessorPair instead of a boolean flag.

src/objects.h

 // 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 1342 matching lines @@
 // Indicates whether a property should be set or (re)defined.  Setting of a
 // property causes attributes to remain unchanged, writability to be checked
 // and callbacks to be called.  Defining of a property causes attributes to
 // be updated and callbacks to be overridden.
 enum SetPropertyMode {
   SET_PROPERTY,
   DEFINE_PROPERTY
 };
 
 
+// Indicator for one component of an AccessorPair.
+enum AccessorComponent {
+  ACCESSOR_GETTER,
+  ACCESSOR_SETTER
+};
+
+
 // JSReceiver includes types on which properties can be defined, i.e.,
 // JSObject and JSProxy.
 class JSReceiver: public HeapObject {
  public:
   enum DeleteMode {
     NORMAL_DELETION,
     STRICT_DELETION,
     FORCE_DELETION
   };
 
@@ skipping 232 matching lines @@
   PropertyAttributes GetPropertyAttributeWithInterceptor(JSObject* receiver,
                                                          String* name,
                                                          bool continue_search);
   PropertyAttributes GetPropertyAttributeWithFailedAccessCheck(
       Object* receiver,
       LookupResult* result,
       String* name,
       bool continue_search);
 
   MUST_USE_RESULT MaybeObject* DefineAccessor(String* name,
-                                              bool is_getter,
+                                              AccessorComponent component,
                                               Object* fun,
                                               PropertyAttributes attributes);
-  Object* LookupAccessor(String* name, bool is_getter);
+  Object* LookupAccessor(String* name, AccessorComponent component);
 
   MUST_USE_RESULT MaybeObject* DefineAccessor(AccessorInfo* info);
 
   // Used from Object::GetProperty().
   MUST_USE_RESULT MaybeObject* GetPropertyWithFailedAccessCheck(
       Object* receiver,
       LookupResult* result,
       String* name,
       PropertyAttributes* attributes);
   MUST_USE_RESULT MaybeObject* GetPropertyWithInterceptor(
@@ skipping 530 matching lines @@
   MUST_USE_RESULT MaybeObject* SetElementCallback(
       uint32_t index,
       Object* structure,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* SetPropertyCallback(
       String* name,
       Object* structure,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* DefineElementAccessor(
       uint32_t index,
-      bool is_getter,
+      AccessorComponent component,
       Object* fun,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* DefinePropertyAccessor(
       String* name,
-      bool is_getter,
+      AccessorComponent component,
       Object* fun,
       PropertyAttributes attributes);
   void LookupInDescriptor(String* name, LookupResult* result);
 
   // Returns the hidden properties backing store object, currently
   // a StringDictionary, stored on this object.
   // If no hidden properties object has been put on this object,
   // return undefined, unless create_if_absent is true, in which case
   // a new dictionary is created, added to this object, and returned.
   MUST_USE_RESULT MaybeObject* GetHiddenPropertiesDictionary(
@@ skipping 5735 matching lines @@
 //   * a pointer to a map: a transition used to ensure map sharing
 class AccessorPair: public Struct {
  public:
   DECL_ACCESSORS(getter, Object)
   DECL_ACCESSORS(setter, Object)
 
   static inline AccessorPair* cast(Object* obj);
 
   MUST_USE_RESULT MaybeObject* CopyWithoutTransitions();
 
-  // TODO(svenpanne) Evil temporary helper, will vanish soon...
-  void set(bool modify_getter, Object* value) {
-    if (modify_getter) {
+  Object* get(AccessorComponent component) {

[Michael Starzinger, 2012/03/05 11:56:30]

If you plan on extending AccessorComponent later (e.g. by ACCESSOR_NONE), it
might be good to have the following assertion in these two functions. Your call.

ASSERT(component == ACCESSOR_GETTER || component == ACCESSOR_SETTER);

[Sven Panne, 2012/03/05 12:08:51]

Given C++'s lovely implicit conversions, I think the ASSERT here and in set
below are a good idea. Done.

+    return (component == ACCESSOR_GETTER) ? getter() : setter();
+  }
+
+  void set(AccessorComponent component, Object* value) {
+    if (component == ACCESSOR_GETTER) {
       set_getter(value);
     } else {
       set_setter(value);
     }
   }
 
   bool ContainsAccessor() {
     return IsJSAccessor(getter()) || IsJSAccessor(setter());
   }
 
@@ skipping 510 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_