JavaScriptCore/runtime/JSActivation.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/JSActivation.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+ 
+#include "config.h"
+#include "JSActivation.h"
+
+#include "Arguments.h"
+#include "Interpreter.h"
+#include "JSFunction.h"
+
+namespace JSC {
+
+ASSERT_CLASS_FITS_IN_CELL(JSActivation);
+
+const ClassInfo JSActivation::info = { "JSActivation", 0, 0, 0 };
+
+JSActivation::JSActivation(CallFrame* callFrame, NonNullPassRefPtr<FunctionExecutable> functionExecutable)
+    : Base(callFrame->globalData().activationStructure, new JSActivationData(functionExecutable, callFrame->registers()))
+{
+}
+
+JSActivation::~JSActivation()
+{
+    delete d();
+}
+
+void JSActivation::markChildren(MarkStack& markStack)
+{
+    Base::markChildren(markStack);
+
+    Register* registerArray = d()->registerArray.get();
+    if (!registerArray)
+        return;
+
+    size_t numParametersMinusThis = d()->functionExecutable->parameterCount();
+
+    size_t count = numParametersMinusThis;
+    markStack.appendValues(registerArray, count);
+
+    size_t numVars = d()->functionExecutable->variableCount();
+
+    // Skip the call frame, which sits between the parameters and vars.
+    markStack.appendValues(registerArray + count + RegisterFile::CallFrameHeaderSize, numVars, MayContainNullValues);
+}
+
+bool JSActivation::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
+{
+    if (propertyName == exec->propertyNames().arguments) {
+        slot.setCustom(this, getArgumentsGetter());
+        return true;
+    }
+
+    if (symbolTableGet(propertyName, slot))
+        return true;
+
+    if (JSValue* location = getDirectLocation(propertyName)) {
+        slot.setValueSlot(location);
+        return true;
+    }
+
+    // We don't call through to JSObject because there's no way to give an 
+    // activation object getter properties or a prototype.
+    ASSERT(!hasGetterSetterProperties());
+    ASSERT(prototype().isNull());
+    return false;
+}
+
+void JSActivation::put(ExecState*, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
+{
+    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
+
+    if (symbolTablePut(propertyName, value))
+        return;
+
+    // We don't call through to JSObject because __proto__ and getter/setter 
+    // properties are non-standard extensions that other implementations do not
+    // expose in the activation object.
+    ASSERT(!hasGetterSetterProperties());
+    putDirect(propertyName, value, 0, true, slot);
+}
+
+// FIXME: Make this function honor ReadOnly (const) and DontEnum
+void JSActivation::putWithAttributes(ExecState* exec, const Identifier& propertyName, JSValue value, unsigned attributes)
+{
+    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
+
+    if (symbolTablePutWithAttributes(propertyName, value, attributes))
+        return;
+
+    // We don't call through to JSObject because __proto__ and getter/setter 
+    // properties are non-standard extensions that other implementations do not
+    // expose in the activation object.
+    ASSERT(!hasGetterSetterProperties());
+    PutPropertySlot slot;
+    JSObject::putWithAttributes(exec, propertyName, value, attributes, true, slot);
+}
+
+bool JSActivation::deleteProperty(ExecState* exec, const Identifier& propertyName)
+{
+    if (propertyName == exec->propertyNames().arguments)
+        return false;
+
+    return Base::deleteProperty(exec, propertyName);
+}
+
+JSObject* JSActivation::toThisObject(ExecState* exec) const
+{
+    return exec->globalThisValue();
+}
+
+bool JSActivation::isDynamicScope(bool& requiresDynamicChecks) const
+{
+    requiresDynamicChecks = d()->functionExecutable->usesEval();
+    return false;
+}
+
+JSValue JSActivation::argumentsGetter(ExecState*, JSValue slotBase, const Identifier&)
+{
+    JSActivation* activation = asActivation(slotBase);
+    CallFrame* callFrame = CallFrame::create(activation->d()->registers);
+    int argumentsRegister = activation->d()->functionExecutable->generatedBytecode().argumentsRegister();
+    if (!callFrame->r(argumentsRegister).jsValue()) {
+        JSValue arguments = JSValue(new (callFrame) Arguments(callFrame));
+        callFrame->r(argumentsRegister) = arguments;
+        callFrame->r(unmodifiedArgumentsRegister(argumentsRegister)) = arguments;
+    }
+
+    ASSERT(callFrame->r(argumentsRegister).jsValue().inherits(&Arguments::info));
+    return callFrame->r(argumentsRegister).jsValue();
+}
+
+// These two functions serve the purpose of isolating the common case from a
+// PIC branch.
+
+PropertySlot::GetValueFunc JSActivation::getArgumentsGetter()
+{
+    return argumentsGetter;
+}
+
+} // namespace JSC