runtime/JSLexicalEnvironment.cpp

   1 /*
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  28
  29 #include "config.h"
  30 #include "JSLexicalEnvironment.h"
  31
  32 #include "Interpreter.h"
  33 #include "JSFunction.h"
  34 #include "JSCInlines.h"
  35
  36 using namespace std;
  37
  38 namespace JSC {
  39
  40 const ClassInfo JSLexicalEnvironment::s_info = { "JSLexicalEnvironment", &Base::s_info, 0, CREATE_METHOD_TABLE(JSLexicalEnvironment) };
  41
  42 inline bool JSLexicalEnvironment::symbolTableGet(PropertyName propertyName, PropertySlot& slot)
  43 {
  44     SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.uid());
  45     if (entry.isNull())
  46         return false;
  47
  48     ScopeOffset offset = entry.scopeOffset();
  49
  50     // Defend against the inspector asking for a var after it has been optimized out.
  51     if (!isValid(offset))
  52         return false;
  53
  54     slot.setValue(this, DontEnum, variableAt(offset).get());
  55     return true;
  56 }
  57
  58 inline bool JSLexicalEnvironment::symbolTableGet(PropertyName propertyName, PropertyDescriptor& descriptor)
  59 {
  60     SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.uid());
  61     if (entry.isNull())
  62         return false;
  63
  64     ScopeOffset offset = entry.scopeOffset();
  65
  66     // Defend against the inspector asking for a var after it has been optimized out.
  67     if (!isValid(offset))
  68         return false;
  69
  70     descriptor.setDescriptor(variableAt(offset).get(), entry.getAttributes());
  71     return true;
  72 }
  73
  74 inline bool JSLexicalEnvironment::symbolTablePut(ExecState* exec, PropertyName propertyName, JSValue value, bool shouldThrow)
  75 {
  76     VM& vm = exec->vm();
  77     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
  78
  79     WriteBarrierBase<Unknown>* reg;
  80     WatchpointSet* set;
  81     {
  82         GCSafeConcurrentJITLocker locker(symbolTable()->m_lock, exec->vm().heap);
  83         SymbolTable::Map::iterator iter = symbolTable()->find(locker, propertyName.uid());
  84         if (iter == symbolTable()->end(locker))
  85             return false;
  86         ASSERT(!iter->value.isNull());
  87         if (iter->value.isReadOnly()) {
  88             if (shouldThrow)
  89                 throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
  90             return true;
  91         }
  92         ScopeOffset offset = iter->value.scopeOffset();
  93         // Defend against the inspector asking for a var after it has been optimized out.
  94         if (!isValid(offset))
  95             return false;
  96         set = iter->value.watchpointSet();
  97         reg = &variableAt(offset);
  98     }
  99     reg->set(vm, this, value);
 100     if (set)
 101         set->invalidate(VariableWriteFireDetail(this, propertyName)); // Don't mess around - if we had found this statically, we would have invalidated it.
 102     return true;
 103 }
 104
 105 void JSLexicalEnvironment::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 106 {
 107     JSLexicalEnvironment* thisObject = jsCast<JSLexicalEnvironment*>(object);
 108
 109     {
 110         ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
 111         SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
 112         for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
 113             if (it->value.getAttributes() & DontEnum && !mode.includeDontEnumProperties())
 114                 continue;
 115             if (!thisObject->isValid(it->value.scopeOffset()))
 116                 continue;
 117             if (it->key->isSymbol() && !mode.includeSymbolProperties())
 118                 continue;
 119             propertyNames.add(Identifier::fromUid(exec, it->key.get()));
 120         }
 121     }
 122     // Skip the JSEnvironmentRecord implementation of getOwnNonIndexPropertyNames
 123     JSObject::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
 124 }
 125
 126 inline bool JSLexicalEnvironment::symbolTablePutWithAttributes(VM& vm, PropertyName propertyName, JSValue value, unsigned attributes)
 127 {
 128     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
 129
 130     WriteBarrierBase<Unknown>* reg;
 131     {
 132         ConcurrentJITLocker locker(symbolTable()->m_lock);
 133         SymbolTable::Map::iterator iter = symbolTable()->find(locker, propertyName.uid());
 134         if (iter == symbolTable()->end(locker))
 135             return false;
 136         SymbolTableEntry& entry = iter->value;
 137         ASSERT(!entry.isNull());
 138
 139         ScopeOffset offset = entry.scopeOffset();
 140         if (!isValid(offset))
 141             return false;
 142
 143         entry.setAttributes(attributes);
 144         reg = &variableAt(offset);
 145     }
 146     reg->set(vm, this, value);
 147     return true;
 148 }
 149
 150 bool JSLexicalEnvironment::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
 151 {
 152     JSLexicalEnvironment* thisObject = jsCast<JSLexicalEnvironment*>(object);
 153
 154     if (thisObject->symbolTableGet(propertyName, slot))
 155         return true;
 156
 157     unsigned attributes;
 158     if (JSValue value = thisObject->getDirect(exec->vm(), propertyName, attributes)) {
 159         slot.setValue(thisObject, attributes, value);
 160         return true;
 161     }
 162
 163     // We don't call through to JSObject because there's no way to give a
 164     // lexical environment object getter properties or a prototype.
 165     ASSERT(!thisObject->hasGetterSetterProperties());
 166     ASSERT(thisObject->prototype().isNull());
 167     return false;
 168 }
 169
 170 void JSLexicalEnvironment::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 171 {
 172     JSLexicalEnvironment* thisObject = jsCast<JSLexicalEnvironment*>(cell);
 173     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(thisObject));
 174
 175     if (thisObject->symbolTablePut(exec, propertyName, value, slot.isStrictMode()))
 176         return;
 177
 178     // We don't call through to JSObject because __proto__ and getter/setter
 179     // properties are non-standard extensions that other implementations do not
 180     // expose in the lexicalEnvironment object.
 181     ASSERT(!thisObject->hasGetterSetterProperties());
 182     thisObject->putOwnDataProperty(exec->vm(), propertyName, value, slot);
 183 }
 184
 185 bool JSLexicalEnvironment::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
 186 {
 187     if (propertyName == exec->propertyNames().arguments)
 188         return false;
 189
 190     return Base::deleteProperty(cell, exec, propertyName);
 191 }
 192
 193 JSValue JSLexicalEnvironment::toThis(JSCell*, ExecState* exec, ECMAMode ecmaMode)
 194 {
 195     if (ecmaMode == StrictMode)
 196         return jsUndefined();
 197     return exec->globalThisValue();
 198 }
 199
 200 } // namespace JSC