JavaScriptCore/runtime/Arguments.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/Arguments.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,243 @@
+/*
+ *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
+ *  Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
+ *  Copyright (C) 2007 Maks Orlovich
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef Arguments_h
+#define Arguments_h
+
+#include "JSActivation.h"
+#include "JSFunction.h"
+#include "JSGlobalObject.h"
+#include "Interpreter.h"
+#include "ObjectConstructor.h"
+#include "PrototypeFunction.h"
+
+namespace JSC {
+
+    struct ArgumentsData : Noncopyable {
+        JSActivation* activation;
+
+        unsigned numParameters;
+        ptrdiff_t firstParameterIndex;
+        unsigned numArguments;
+
+        Register* registers;
+        OwnArrayPtr<Register> registerArray;
+
+        Register* extraArguments;
+        OwnArrayPtr<bool> deletedArguments;
+        Register extraArgumentsFixedBuffer[4];
+
+        JSFunction* callee;
+        bool overrodeLength : 1;
+        bool overrodeCallee : 1;
+    };
+
+
+    class Arguments : public JSObject {
+    public:
+        // Use an enum because otherwise gcc insists on doing a memory
+        // read.
+        enum { MaxArguments = 0x10000 };
+
+        enum NoParametersType { NoParameters };
+
+        Arguments(CallFrame*);
+        Arguments(CallFrame*, NoParametersType);
+        virtual ~Arguments();
+
+        static const ClassInfo info;
+
+        virtual void markChildren(MarkStack&);
+
+        void fillArgList(ExecState*, MarkedArgumentBuffer&);
+
+        uint32_t numProvidedArguments(ExecState* exec) const 
+        {
+            if (UNLIKELY(d->overrodeLength))
+                return get(exec, exec->propertyNames().length).toUInt32(exec);
+            return d->numArguments; 
+        }
+        
+        void copyToRegisters(ExecState* exec, Register* buffer, uint32_t maxSize);
+        void copyRegisters();
+        bool isTornOff() const { return d->registerArray; }
+        void setActivation(JSActivation* activation)
+        {
+            d->activation = activation;
+            d->registers = &activation->registerAt(0);
+        }
+
+        static PassRefPtr<Structure> createStructure(JSValue prototype) 
+        { 
+            return Structure::create(prototype, TypeInfo(ObjectType, StructureFlags), AnonymousSlotCount); 
+        }
+
+    protected:
+        static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesMarkChildren | OverridesGetPropertyNames | JSObject::StructureFlags;
+
+    private:
+        void getArgumentsData(CallFrame*, JSFunction*&, ptrdiff_t& firstParameterIndex, Register*& argv, int& argc);
+        virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
+        virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
+        virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
+        virtual void getOwnPropertyNames(ExecState*, PropertyNameArray&, EnumerationMode mode = ExcludeDontEnumProperties);
+        virtual void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);
+        virtual void put(ExecState*, unsigned propertyName, JSValue, PutPropertySlot&);
+        virtual bool deleteProperty(ExecState*, const Identifier& propertyName);
+        virtual bool deleteProperty(ExecState*, unsigned propertyName);
+
+        virtual const ClassInfo* classInfo() const { return &info; }
+
+        void init(CallFrame*);
+
+        OwnPtr<ArgumentsData> d;
+    };
+
+    Arguments* asArguments(JSValue);
+
+    inline Arguments* asArguments(JSValue value)
+    {
+        ASSERT(asObject(value)->inherits(&Arguments::info));
+        return static_cast<Arguments*>(asObject(value));
+    }
+
+    ALWAYS_INLINE void Arguments::getArgumentsData(CallFrame* callFrame, JSFunction*& function, ptrdiff_t& firstParameterIndex, Register*& argv, int& argc)
+    {
+        function = asFunction(callFrame->callee());
+
+        int numParameters = function->jsExecutable()->parameterCount();
+        argc = callFrame->argumentCountIncludingThis();
+
+        if (argc <= numParameters)
+            argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numParameters;
+        else
+            argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numParameters - argc;
+
+        argc -= 1; // - 1 to skip "this"
+        firstParameterIndex = -RegisterFile::CallFrameHeaderSize - numParameters;
+    }
+
+    inline Arguments::Arguments(CallFrame* callFrame)
+        : JSObject(callFrame->lexicalGlobalObject()->argumentsStructure())
+        , d(adoptPtr(new ArgumentsData))
+    {
+        JSFunction* callee;
+        ptrdiff_t firstParameterIndex;
+        Register* argv;
+        int numArguments;
+        getArgumentsData(callFrame, callee, firstParameterIndex, argv, numArguments);
+
+        d->numParameters = callee->jsExecutable()->parameterCount();
+        d->firstParameterIndex = firstParameterIndex;
+        d->numArguments = numArguments;
+
+        d->activation = 0;
+        d->registers = callFrame->registers();
+
+        Register* extraArguments;
+        if (d->numArguments <= d->numParameters)
+            extraArguments = 0;
+        else {
+            unsigned numExtraArguments = d->numArguments - d->numParameters;
+            if (numExtraArguments > sizeof(d->extraArgumentsFixedBuffer) / sizeof(Register))
+                extraArguments = new Register[numExtraArguments];
+            else
+                extraArguments = d->extraArgumentsFixedBuffer;
+            for (unsigned i = 0; i < numExtraArguments; ++i)
+                extraArguments[i] = argv[d->numParameters + i];
+        }
+
+        d->extraArguments = extraArguments;
+
+        d->callee = callee;
+        d->overrodeLength = false;
+        d->overrodeCallee = false;
+    }
+
+    inline Arguments::Arguments(CallFrame* callFrame, NoParametersType)
+        : JSObject(callFrame->lexicalGlobalObject()->argumentsStructure())
+        , d(adoptPtr(new ArgumentsData))
+    {
+        ASSERT(!asFunction(callFrame->callee())->jsExecutable()->parameterCount());
+
+        unsigned numArguments = callFrame->argumentCount();
+
+        d->numParameters = 0;
+        d->numArguments = numArguments;
+        d->activation = 0;
+
+        Register* extraArguments;
+        if (numArguments > sizeof(d->extraArgumentsFixedBuffer) / sizeof(Register))
+            extraArguments = new Register[numArguments];
+        else
+            extraArguments = d->extraArgumentsFixedBuffer;
+
+        Register* argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numArguments - 1;
+        for (unsigned i = 0; i < numArguments; ++i)
+            extraArguments[i] = argv[i];
+
+        d->extraArguments = extraArguments;
+
+        d->callee = asFunction(callFrame->callee());
+        d->overrodeLength = false;
+        d->overrodeCallee = false;
+    }
+
+    inline void Arguments::copyRegisters()
+    {
+        ASSERT(!isTornOff());
+
+        if (!d->numParameters)
+            return;
+
+        int registerOffset = d->numParameters + RegisterFile::CallFrameHeaderSize;
+        size_t registerArraySize = d->numParameters;
+
+        Register* registerArray = new Register[registerArraySize];
+        memcpy(registerArray, d->registers - registerOffset, registerArraySize * sizeof(Register));
+        d->registerArray.set(registerArray);
+        d->registers = registerArray + registerOffset;
+    }
+
+    // This JSActivation function is defined here so it can get at Arguments::setRegisters.
+    inline void JSActivation::copyRegisters()
+    {
+        ASSERT(!d()->registerArray);
+
+        size_t numParametersMinusThis = d()->functionExecutable->parameterCount();
+        size_t numVars = d()->functionExecutable->variableCount();
+        size_t numLocals = numVars + numParametersMinusThis;
+
+        if (!numLocals)
+            return;
+
+        int registerOffset = numParametersMinusThis + RegisterFile::CallFrameHeaderSize;
+        size_t registerArraySize = numLocals + RegisterFile::CallFrameHeaderSize;
+
+        Register* registerArray = copyRegisterArray(d()->registers - registerOffset, registerArraySize);
+        setRegisters(registerArray + registerOffset, registerArray);
+    }
+
+} // namespace JSC
+
+#endif // Arguments_h