runtime/JSActivation.cpp

   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 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;
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  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 #include "config.h"
  30 #include "JSActivation.h"
  31
  32 #include "Arguments.h"
  33 #include "Interpreter.h"
  34 #include "JSFunction.h"
  35 #include "JSCInlines.h"
  36
  37 using namespace std;
  38
  39 namespace JSC {
  40
  41 const ClassInfo JSActivation::s_info = { "JSActivation", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(JSActivation) };
  42
  43 void JSActivation::visitChildren(JSCell* cell, SlotVisitor& visitor)
  44 {
  45     JSActivation* thisObject = jsCast<JSActivation*>(cell);
  46     ASSERT_GC_OBJECT_INHERITS(thisObject, info());
  47     COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
  48     ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
  49     Base::visitChildren(thisObject, visitor);
  50
  51     // No need to mark our registers if they're still in the JSStack.
  52     if (!thisObject->isTornOff())
  53         return;
  54
  55     for (int i = 0; i < thisObject->symbolTable()->captureCount(); ++i)
  56         visitor.append(&thisObject->storage()[i]);
  57 }
  58
  59 inline bool JSActivation::symbolTableGet(PropertyName propertyName, PropertySlot& slot)
  60 {
  61     SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.uid());
  62     if (entry.isNull())
  63         return false;
  64
  65     // Defend against the inspector asking for a var after it has been optimized out.
  66     if (isTornOff() && !isValid(entry))
  67         return false;
  68
  69     slot.setValue(this, DontEnum, registerAt(entry.getIndex()).get());
  70     return true;
  71 }
  72
  73 inline bool JSActivation::symbolTableGet(PropertyName propertyName, PropertyDescriptor& descriptor)
  74 {
  75     SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.uid());
  76     if (entry.isNull())
  77         return false;
  78
  79     // Defend against the inspector asking for a var after it has been optimized out.
  80     if (isTornOff() && !isValid(entry))
  81         return false;
  82
  83     descriptor.setDescriptor(registerAt(entry.getIndex()).get(), entry.getAttributes());
  84     return true;
  85 }
  86
  87 inline bool JSActivation::symbolTablePut(ExecState* exec, PropertyName propertyName, JSValue value, bool shouldThrow)
  88 {
  89     VM& vm = exec->vm();
  90     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
  91
  92     WriteBarrierBase<Unknown>* reg;
  93     {
  94         GCSafeConcurrentJITLocker locker(symbolTable()->m_lock, exec->vm().heap);
  95         SymbolTable::Map::iterator iter = symbolTable()->find(locker, propertyName.uid());
  96         if (iter == symbolTable()->end(locker))
  97             return false;
  98         ASSERT(!iter->value.isNull());
  99         if (iter->value.isReadOnly()) {
 100             if (shouldThrow)
 101                 throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
 102             return true;
 103         }
 104         // Defend against the inspector asking for a var after it has been optimized out.
 105         if (isTornOff() && !isValid(iter->value))
 106             return false;
 107         if (VariableWatchpointSet* set = iter->value.watchpointSet())
 108             set->invalidate(); // Don't mess around - if we had found this statically, we would have invcalidated it.
 109         reg = &registerAt(iter->value.getIndex());
 110     }
 111     reg->set(vm, this, value);
 112     return true;
 113 }
 114
 115 void JSActivation::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 116 {
 117     JSActivation* thisObject = jsCast<JSActivation*>(object);
 118
 119     CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(thisObject->m_registers));
 120     if (mode == IncludeDontEnumProperties && !thisObject->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()))
 121         propertyNames.add(exec->propertyNames().arguments);
 122
 123     {
 124         ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
 125         SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
 126         for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
 127             if (it->value.getAttributes() & DontEnum && mode != IncludeDontEnumProperties)
 128                 continue;
 129             if (!thisObject->isValid(it->value))
 130                 continue;
 131             propertyNames.add(Identifier(exec, it->key.get()));
 132         }
 133     }
 134     // Skip the JSVariableObject implementation of getOwnNonIndexPropertyNames
 135     JSObject::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
 136 }
 137
 138 inline bool JSActivation::symbolTablePutWithAttributes(VM& vm, PropertyName propertyName, JSValue value, unsigned attributes)
 139 {
 140     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
 141
 142     WriteBarrierBase<Unknown>* reg;
 143     {
 144         ConcurrentJITLocker locker(symbolTable()->m_lock);
 145         SymbolTable::Map::iterator iter = symbolTable()->find(locker, propertyName.uid());
 146         if (iter == symbolTable()->end(locker))
 147             return false;
 148         SymbolTableEntry& entry = iter->value;
 149         ASSERT(!entry.isNull());
 150         if (!isValid(entry))
 151             return false;
 152
 153         entry.setAttributes(attributes);
 154         reg = &registerAt(entry.getIndex());
 155     }
 156     reg->set(vm, this, value);
 157     return true;
 158 }
 159
 160 bool JSActivation::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
 161 {
 162     JSActivation* thisObject = jsCast<JSActivation*>(object);
 163
 164     if (propertyName == exec->propertyNames().arguments) {
 165         // Defend against the inspector asking for the arguments object after it has been optimized out.
 166         CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(thisObject->m_registers));
 167         if (!thisObject->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval())) {
 168             slot.setCustom(thisObject, DontEnum, argumentsGetter);
 169             return true;
 170         }
 171     }
 172
 173     if (thisObject->symbolTableGet(propertyName, slot))
 174         return true;
 175
 176     unsigned attributes;
 177     if (JSValue value = thisObject->getDirect(exec->vm(), propertyName, attributes)) {
 178         slot.setValue(thisObject, attributes, value);
 179         return true;
 180     }
 181
 182     // We don't call through to JSObject because there's no way to give an
 183     // activation object getter properties or a prototype.
 184     ASSERT(!thisObject->hasGetterSetterProperties());
 185     ASSERT(thisObject->prototype().isNull());
 186     return false;
 187 }
 188
 189 void JSActivation::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 190 {
 191     JSActivation* thisObject = jsCast<JSActivation*>(cell);
 192     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(thisObject));
 193
 194     if (thisObject->symbolTablePut(exec, propertyName, value, slot.isStrictMode()))
 195         return;
 196
 197     // We don't call through to JSObject because __proto__ and getter/setter
 198     // properties are non-standard extensions that other implementations do not
 199     // expose in the activation object.
 200     ASSERT(!thisObject->hasGetterSetterProperties());
 201     thisObject->putOwnDataProperty(exec->vm(), propertyName, value, slot);
 202 }
 203
 204 bool JSActivation::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
 205 {
 206     if (propertyName == exec->propertyNames().arguments)
 207         return false;
 208
 209     return Base::deleteProperty(cell, exec, propertyName);
 210 }
 211
 212 JSValue JSActivation::toThis(JSCell*, ExecState* exec, ECMAMode ecmaMode)
 213 {
 214     if (ecmaMode == StrictMode)
 215         return jsUndefined();
 216     return exec->globalThisValue();
 217 }
 218
 219 EncodedJSValue JSActivation::argumentsGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
 220 {
 221     JSActivation* activation = jsCast<JSActivation*>(slotBase);
 222     CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(activation->m_registers));
 223     ASSERT(!activation->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()));
 224     if (activation->isTornOff() || !(callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()))
 225         return JSValue::encode(jsUndefined());
 226
 227     VirtualRegister argumentsRegister = callFrame->codeBlock()->argumentsRegister();
 228     if (JSValue arguments = callFrame->uncheckedR(argumentsRegister.offset()).jsValue())
 229         return JSValue::encode(arguments);
 230     int realArgumentsRegister = unmodifiedArgumentsRegister(argumentsRegister).offset();
 231
 232     JSValue arguments = JSValue(Arguments::create(callFrame->vm(), callFrame));
 233     callFrame->uncheckedR(argumentsRegister.offset()) = arguments;
 234     callFrame->uncheckedR(realArgumentsRegister) = arguments;
 235
 236     ASSERT(callFrame->uncheckedR(realArgumentsRegister).jsValue().inherits(Arguments::info()));
 237     return JSValue::encode(callFrame->uncheckedR(realArgumentsRegister).jsValue());
 238 }
 239
 240 } // namespace JSC