1 /*

     2  * Copyright (C) 2008, 2009 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 

    34 namespace 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, StructureFlags), AnonymousSlotCount);

    66         }

    67 

    68      private:

    69         

    70         static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesMarkChildren | OverridesGetPropertyNames | JSObject::StructureFlags;

    71 

    72         // JSValue methods

    73         virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;

    74         virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue&);

    75         virtual bool toBoolean(ExecState*) const;

    76         virtual double toNumber(ExecState*) const;

    77         virtual UString toString(ExecState*) const;

    78         virtual JSObject* toObject(ExecState*) const;

    79 

    80         // Marking

    81         virtual void markChildren(MarkStack&);

    82 

    83         // JSObject methods

    84         virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);

    85         virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);

    86         virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);

    87 

    88         virtual void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);

    89         virtual void put(ExecState*, unsigned propertyName, JSValue);

    90 

    91         virtual bool deleteProperty(ExecState*, const Identifier& propertyName);

    92         virtual bool deleteProperty(ExecState*, unsigned propertyName);

    93 

    94         virtual void getOwnPropertyNames(ExecState*, PropertyNameArray&, EnumerationMode mode = ExcludeDontEnumProperties);

    95 

    96         JSNotAnObjectErrorStub* m_exception;

    97     };

    98 

    99 } // namespace JSC

   100 

   101 #endif // JSNotAnObject_h