runtime/JSActivation.h

   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 JSActivation_h
  30 #define JSActivation_h
  31
  32 #include "CodeBlock.h"
  33 #include "JSVariableObject.h"
  34 #include "SymbolTable.h"
  35 #include "Nodes.h"
  36
  37 namespace JSC {
  38
  39     class Arguments;
  40     class Register;
  41
  42     class JSActivation : public JSVariableObject {
  43     private:
  44         JSActivation(CallFrame*, FunctionExecutable*);
  45
  46     public:
  47         typedef JSVariableObject Base;
  48
  49         static JSActivation* create(JSGlobalData& globalData, CallFrame* callFrame, FunctionExecutable* funcExec)
  50         {
  51             JSActivation* activation = new (NotNull, allocateCell<JSActivation>(globalData.heap)) JSActivation(callFrame, funcExec);
  52             activation->finishCreation(callFrame);
  53             return activation;
  54         }
  55
  56         static void finalize(JSCell*);
  57
  58         static void visitChildren(JSCell*, SlotVisitor&);
  59
  60         bool isDynamicScope(bool& requiresDynamicChecks) const;
  61
  62         static bool getOwnPropertySlot(JSCell*, ExecState*, const Identifier&, PropertySlot&);
  63         static void getOwnPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
  64
  65         static void put(JSCell*, ExecState*, const Identifier&, JSValue, PutPropertySlot&);
  66
  67         static void putDirectVirtual(JSObject*, ExecState*, const Identifier&, JSValue, unsigned attributes);
  68         static bool deleteProperty(JSCell*, ExecState*, const Identifier& propertyName);
  69
  70         static JSObject* toThisObject(JSCell*, ExecState*);
  71
  72         void tearOff(JSGlobalData&);
  73
  74         static const ClassInfo s_info;
  75
  76         static Structure* createStructure(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue proto) { return Structure::create(globalData, globalObject, proto, TypeInfo(ActivationObjectType, StructureFlags), &s_info); }
  77
  78         bool isValidScopedLookup(int index) { return index < m_numCapturedVars; }
  79
  80     protected:
  81         void finishCreation(CallFrame*);
  82         static const unsigned StructureFlags = IsEnvironmentRecord | OverridesGetOwnPropertySlot | OverridesVisitChildren | OverridesGetPropertyNames | JSVariableObject::StructureFlags;
  83
  84     private:
  85         bool symbolTableGet(const Identifier&, PropertySlot&);
  86         bool symbolTableGet(const Identifier&, PropertyDescriptor&);
  87         bool symbolTableGet(const Identifier&, PropertySlot&, bool& slotIsWriteable);
  88         bool symbolTablePut(ExecState*, const Identifier&, JSValue, bool shouldThrow);
  89         bool symbolTablePutWithAttributes(JSGlobalData&, const Identifier&, JSValue, unsigned attributes);
  90
  91         static JSValue argumentsGetter(ExecState*, JSValue, const Identifier&);
  92         NEVER_INLINE PropertySlot::GetValueFunc getArgumentsGetter();
  93
  94         int m_numCapturedArgs;
  95         int m_numCapturedVars : 30;
  96         bool m_isTornOff : 1;
  97         bool m_requiresDynamicChecks : 1;
  98         int m_argumentsRegister;
  99     };
 100
 101     JSActivation* asActivation(JSValue);
 102
 103     inline JSActivation* asActivation(JSValue value)
 104     {
 105         ASSERT(asObject(value)->inherits(&JSActivation::s_info));
 106         return jsCast<JSActivation*>(asObject(value));
 107     }
 108
 109     ALWAYS_INLINE JSActivation* Register::activation() const
 110     {
 111         return asActivation(jsValue());
 112     }
 113
 114     inline bool JSActivation::isDynamicScope(bool& requiresDynamicChecks) const
 115     {
 116         requiresDynamicChecks = m_requiresDynamicChecks;
 117         return false;
 118     }
 119
 120     inline void JSActivation::tearOff(JSGlobalData& globalData)
 121     {
 122         ASSERT(!m_registerArray);
 123         ASSERT(m_numCapturedVars + m_numCapturedArgs);
 124
 125         int registerOffset = CallFrame::offsetFor(m_numCapturedArgs + 1);
 126         size_t registerArraySize = registerOffset + m_numCapturedVars;
 127
 128         OwnArrayPtr<WriteBarrier<Unknown> > registerArray = adoptArrayPtr(new WriteBarrier<Unknown>[registerArraySize]);
 129         WriteBarrier<Unknown>* registers = registerArray.get() + registerOffset;
 130
 131         int from = CallFrame::argumentOffset(m_numCapturedArgs - 1);
 132         int to = m_numCapturedVars;
 133         for (int i = from; i < to; ++i)
 134             registers[i].set(globalData, this, m_registers[i].get());
 135
 136         setRegisters(registers, registerArray.release());
 137         m_isTornOff = true;
 138     }
 139
 140 } // namespace JSC
 141
 142 #endif // JSActivation_h