1/*
2 * Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
3 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
4 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2014 Apple Inc. All rights reserved.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public License
17 * along with this library; see the file COPYING.LIB. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 *
21 */
22
23#pragma once
24
25#include "JSCast.h"
26
27#include "CallFrame.h"
28#include "JSGlobalObject.h"
29#include "NullGetterFunction.h"
30#include "NullSetterFunction.h"
31#include "Structure.h"
32
33namespace JSC {
34
35class JSObject;
36
37// This is an internal value object which stores getter and setter functions
38// for a property. Instances of this class have the property that once a getter
39// or setter is set to a non-null value, then they cannot be changed. This means
40// that if a property holding a GetterSetter reference is constant-inferred and
41// that constant is observed to have a non-null setter (or getter) then we can
42// constant fold that setter (or getter).
43class GetterSetter final : public JSNonFinalObject {
44 friend class JIT;
45 typedef JSNonFinalObject Base;
46private:
47 GetterSetter(VM& vm, JSGlobalObject* globalObject, JSObject* getter, JSObject* setter)
48 : Base(vm, globalObject->getterSetterStructure())
49 {
50 WTF::storeStoreFence();
51 m_getter.set(vm, this, getter ? getter : globalObject->nullGetterFunction());
52 m_setter.set(vm, this, setter ? setter : globalObject->nullSetterFunction());
53 }
54
55public:
56
57 static const unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | StructureIsImmortal;
58
59 static GetterSetter* create(VM& vm, JSGlobalObject* globalObject, JSObject* getter, JSObject* setter)
60 {
61 GetterSetter* getterSetter = new (NotNull, allocateCell<GetterSetter>(vm.heap)) GetterSetter(vm, globalObject, getter, setter);
62 getterSetter->finishCreation(vm);
63 return getterSetter;
64 }
65
66 static GetterSetter* create(VM& vm, JSGlobalObject* globalObject, JSValue getter, JSValue setter)
67 {
68 ASSERT(getter.isUndefined() || getter.isObject());
69 ASSERT(setter.isUndefined() || setter.isObject());
70 JSObject* getterObject { nullptr };
71 JSObject* setterObject { nullptr };
72 if (getter.isObject())
73 getterObject = asObject(getter);
74 if (setter.isObject())
75 setterObject = asObject(setter);
76 return create(vm, globalObject, getterObject, setterObject);
77 }
78
79 static void visitChildren(JSCell*, SlotVisitor&);
80
81 JSObject* getter() const { return m_getter.get(); }
82
83 JSObject* getterConcurrently() const
84 {
85 JSObject* result = getter();
86 WTF::loadLoadFence();
87 return result;
88 }
89
90 bool isGetterNull() const { return !!jsDynamicCast<NullGetterFunction*>(*m_getter.get()->vm(), m_getter.get()); }
91 bool isSetterNull() const { return !!jsDynamicCast<NullSetterFunction*>(*m_setter.get()->vm(), m_setter.get()); }
92
93 JSObject* setter() const { return m_setter.get(); }
94
95 JSObject* setterConcurrently() const
96 {
97 JSObject* result = setter();
98 WTF::loadLoadFence();
99 return result;
100 }
101
102 static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
103 {
104 return Structure::create(vm, globalObject, prototype, TypeInfo(GetterSetterType), info());
105 }
106
107 static ptrdiff_t offsetOfGetter()
108 {
109 return OBJECT_OFFSETOF(GetterSetter, m_getter);
110 }
111
112 static ptrdiff_t offsetOfSetter()
113 {
114 return OBJECT_OFFSETOF(GetterSetter, m_setter);
115 }
116
117 DECLARE_EXPORT_INFO;
118
119 static bool getOwnPropertySlot(JSObject*, ExecState*, PropertyName, PropertySlot&) { RELEASE_ASSERT_NOT_REACHED(); return false; }
120 static bool put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&) { RELEASE_ASSERT_NOT_REACHED(); return false; }
121 static bool putByIndex(JSCell*, ExecState*, unsigned, JSValue, bool) { RELEASE_ASSERT_NOT_REACHED(); return false; }
122 static bool setPrototype(JSObject*, ExecState*, JSValue, bool) { RELEASE_ASSERT_NOT_REACHED(); return false; }
123 static bool defineOwnProperty(JSObject*, ExecState*, PropertyName, const PropertyDescriptor&, bool) { RELEASE_ASSERT_NOT_REACHED(); return false; }
124 static bool deleteProperty(JSCell*, ExecState*, PropertyName) { RELEASE_ASSERT_NOT_REACHED(); return false; }
125
126private:
127 WriteBarrier<JSObject> m_getter;
128 WriteBarrier<JSObject> m_setter;
129};
130
131JSValue callGetter(ExecState*, JSValue base, JSValue getterSetter);
132JS_EXPORT_PRIVATE bool callSetter(ExecState*, JSValue base, JSValue getterSetter, JSValue, ECMAMode);
133
134} // namespace JSC
135