JSNotAnObject.h revision 5f1ab04193ad0130ca8204aadaceae083aca9881 
1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef JSNotAnObject_h
30#define JSNotAnObject_h
31
32#include "JSObject.h"
33
34namespace JSC {
35
36    class JSNotAnObjectErrorStub : public JSObject {
37    public:
38        JSNotAnObjectErrorStub(ExecState* exec, bool isNull)
39            : JSObject(exec->globalData().notAnObjectErrorStubStructure)
40            , m_isNull(isNull)
41        {
42        }
43
44        bool isNull() const { return m_isNull; }
45
46    private:
47        virtual bool isNotAnObjectErrorStub() const { return true; }
48
49        bool m_isNull;
50    };
51
52    // This unholy class is used to allow us to avoid multiple exception checks
53    // in certain SquirrelFish bytecodes -- effectively it just silently consumes
54    // any operations performed on the result of a failed toObject call.
55    class JSNotAnObject : public JSObject {
56    public:
57        JSNotAnObject(ExecState* exec, JSNotAnObjectErrorStub* exception)
58            : JSObject(exec->globalData().notAnObjectStructure)
59            , m_exception(exception)
60        {
61        }
62
63        static PassRefPtr<Structure> createStructure(JSValue prototype)
64        {
65            return Structure::create(prototype, TypeInfo(ObjectType));
66        }
67
68     private:
69        // JSValue methods
70        virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
71        virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue&);
72        virtual bool toBoolean(ExecState*) const;
73        virtual double toNumber(ExecState*) const;
74        virtual UString toString(ExecState*) const;
75        virtual JSObject* toObject(ExecState*) const;
76
77        // Marking
78        virtual void mark();
79
80        // JSObject methods
81        virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
82        virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
83
84        virtual void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);
85        virtual void put(ExecState*, unsigned propertyName, JSValue);
86
87        virtual bool deleteProperty(ExecState*, const Identifier& propertyName);
88        virtual bool deleteProperty(ExecState*, unsigned propertyName);
89
90        virtual void getPropertyNames(ExecState*, PropertyNameArray&);
91
92        JSNotAnObjectErrorStub* m_exception;
93    };
94
95} // namespace JSC
96
97#endif // JSNotAnObject_h
98