jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/runtime/ScriptObject.java@e94bfa3c6c6c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java@e94bfa3c6c6c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java

Thu, 11 Sep 2014 18:04:54 +0200

author: hannesw
date: Thu, 11 Sep 2014 18:04:54 +0200
changeset 1006: e94bfa3c6c6c
parent 991: b7a2db4de254
child 1007: 39ba6d257e4c
permissions: -rw-r--r--

8057021: UserAccessorProperty guards fail with multiple globals
Reviewed-by: attila, lagergren

 /*
  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code 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 General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.nashorn.internal.runtime;
 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCall;
 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
 import static jdk.nashorn.internal.codegen.ObjectClassGenerator.OBJECT_FIELDS_ONLY;
 import static jdk.nashorn.internal.lookup.Lookup.MH;
 import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
 import static jdk.nashorn.internal.runtime.JSType.UNDEFINED_DOUBLE;
 import static jdk.nashorn.internal.runtime.JSType.UNDEFINED_INT;
 import static jdk.nashorn.internal.runtime.JSType.UNDEFINED_LONG;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.CONFIGURABLE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.ENUMERABLE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.GET;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.SET;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.VALUE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.WRITABLE;
 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;
 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;
 import static jdk.nashorn.internal.runtime.linker.NashornGuards.explicitInstanceOfCheck;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import java.lang.invoke.SwitchPoint;
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import jdk.internal.dynalink.CallSiteDescriptor;
 import jdk.internal.dynalink.linker.GuardedInvocation;
 import jdk.internal.dynalink.linker.LinkRequest;
 import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
 import jdk.nashorn.internal.codegen.ObjectClassGenerator;
 import jdk.nashorn.internal.codegen.types.Type;
 import jdk.nashorn.internal.lookup.Lookup;
 import jdk.nashorn.internal.objects.AccessorPropertyDescriptor;
 import jdk.nashorn.internal.objects.DataPropertyDescriptor;
 import jdk.nashorn.internal.objects.Global;
 import jdk.nashorn.internal.objects.NativeArray;
 import jdk.nashorn.internal.runtime.arrays.ArrayData;
 import jdk.nashorn.internal.runtime.arrays.ArrayIndex;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
 import jdk.nashorn.internal.runtime.linker.NashornGuards;
 /**
  * Base class for generic JavaScript objects.
  * <p>
  * Notes:
  * <ul>
  * <li>The map is used to identify properties in the object.</li>
  * <li>If the map is modified then it must be cloned and replaced.  This notifies
  *     any code that made assumptions about the object that things have changed.
  *     Ex. CallSites that have been validated must check to see if the map has
  *     changed (or a map from a different object type) and hence relink the method
  *     to call.</li>
  * <li>Modifications of the map include adding/deleting attributes or changing a
  *     function field value.</li>
  * </ul>
  */
 public abstract class ScriptObject implements PropertyAccess {
     /** __proto__ special property name inside object literals. ES6 draft. */
     public static final String PROTO_PROPERTY_NAME   = "__proto__";
     /** Search fall back routine name for "no such method" */
     public static final String NO_SUCH_METHOD_NAME   = "__noSuchMethod__";
     /** Search fall back routine name for "no such property" */
     public static final String NO_SUCH_PROPERTY_NAME = "__noSuchProperty__";
     /** Per ScriptObject flag - is this a scope object? */
     public static final int IS_SCOPE       = 1 << 0;
     /** Per ScriptObject flag - is this an array object? */
     public static final int IS_ARRAY       = 1 << 1;
     /** Per ScriptObject flag - is this an arguments object? */
     public static final int IS_ARGUMENTS   = 1 << 2;
     /** Is length property not-writable? */
     public static final int IS_LENGTH_NOT_WRITABLE = 1 << 3;
     /** Is this a builtin object? */
     public static final int IS_BUILTIN = 1 << 4;
     /**
      * Spill growth rate - by how many elements does {@link ScriptObject#primitiveSpill} and
      * {@link ScriptObject#objectSpill} when full
      */
     public static final int SPILL_RATE = 8;
     /** Map to property information and accessor functions. Ordered by insertion. */
     private PropertyMap map;
     /** objects proto. */
     private ScriptObject proto;
     /** Object flags. */
     private int flags;
     /** Area for primitive properties added to object after instantiation, see {@link AccessorProperty} */
     protected long[]   primitiveSpill;
     /** Area for reference properties added to object after instantiation, see {@link AccessorProperty} */
     protected Object[] objectSpill;
     /**
      * Number of elements in the spill. This may be less than the spill array lengths, if not all of
      * the allocated memory is in use
      */
     private int spillLength;
     /** Indexed array data. */
     private ArrayData arrayData;
     /** Method handle to retrieve prototype of this object */
     public static final MethodHandle GETPROTO      = findOwnMH_V("getProto", ScriptObject.class);
     static final MethodHandle MEGAMORPHIC_GET    = findOwnMH_V("megamorphicGet", Object.class, String.class, boolean.class);
     static final MethodHandle GLOBALFILTER       = findOwnMH_S("globalFilter", Object.class, Object.class);
     static final MethodHandle DECLARE_AND_SET    = findOwnMH_V("declareAndSet", void.class, String.class, Object.class);
     private static final MethodHandle TRUNCATINGFILTER   = findOwnMH_S("truncatingFilter", Object[].class, int.class, Object[].class);
     private static final MethodHandle KNOWNFUNCPROPGUARDSELF = findOwnMH_S("knownFunctionPropertyGuardSelf", boolean.class, Object.class, PropertyMap.class, MethodHandle.class, ScriptFunction.class);
     private static final MethodHandle KNOWNFUNCPROPGUARDPROTO = findOwnMH_S("knownFunctionPropertyGuardProto", boolean.class, Object.class, PropertyMap.class, MethodHandle.class, int.class, ScriptFunction.class);
     private static final ArrayList<MethodHandle> PROTO_FILTERS = new ArrayList<>();
     /** Method handle for getting the array data */
     public static final Call GET_ARRAY          = virtualCall(MethodHandles.lookup(), ScriptObject.class, "getArray", ArrayData.class);
     /** Method handle for getting the property map - debugging purposes */
     public static final Call GET_MAP            = virtualCall(MethodHandles.lookup(), ScriptObject.class, "getMap", PropertyMap.class);
     /** Method handle for setting the array data */
     public static final Call SET_ARRAY          = virtualCall(MethodHandles.lookup(), ScriptObject.class, "setArray", void.class, ArrayData.class);
     /** Method handle for getting a function argument at a given index. Used from MapCreator */
     public static final Call GET_ARGUMENT       = virtualCall(MethodHandles.lookup(), ScriptObject.class, "getArgument", Object.class, int.class);
     /** Method handle for setting a function argument at a given index. Used from MapCreator */
     public static final Call SET_ARGUMENT       = virtualCall(MethodHandles.lookup(), ScriptObject.class, "setArgument", void.class, int.class, Object.class);
     /** Method handle for getting the proto of a ScriptObject */
     public static final Call GET_PROTO          = virtualCallNoLookup(ScriptObject.class, "getProto", ScriptObject.class);
     /** Method handle for getting the proto of a ScriptObject */
     public static final Call GET_PROTO_DEPTH    = virtualCallNoLookup(ScriptObject.class, "getProto", ScriptObject.class, int.class);
     /** Method handle for setting the proto of a ScriptObject */
     public static final Call SET_GLOBAL_OBJECT_PROTO = staticCallNoLookup(ScriptObject.class, "setGlobalObjectProto", void.class, ScriptObject.class);
     /** Method handle for setting the proto of a ScriptObject after checking argument */
     public static final Call SET_PROTO_FROM_LITERAL    = virtualCallNoLookup(ScriptObject.class, "setProtoFromLiteral", void.class, Object.class);
     /** Method handle for setting the user accessors of a ScriptObject */
     //TODO fastpath this
     public static final Call SET_USER_ACCESSORS = virtualCall(MethodHandles.lookup(), ScriptObject.class, "setUserAccessors", void.class, String.class, ScriptFunction.class, ScriptFunction.class);
     static final MethodHandle[] SET_SLOW = new MethodHandle[] {
         findOwnMH_V("set", void.class, Object.class, int.class, boolean.class),
         findOwnMH_V("set", void.class, Object.class, long.class, boolean.class),
         findOwnMH_V("set", void.class, Object.class, double.class, boolean.class),
         findOwnMH_V("set", void.class, Object.class, Object.class, boolean.class)
     };
     /** Method handle to reset the map of this ScriptObject */
     public static final Call SET_MAP = virtualCallNoLookup(ScriptObject.class, "setMap", void.class, PropertyMap.class);
     static final MethodHandle CAS_MAP           = findOwnMH_V("compareAndSetMap", boolean.class, PropertyMap.class, PropertyMap.class);
     static final MethodHandle EXTENSION_CHECK   = findOwnMH_V("extensionCheck", boolean.class, boolean.class, String.class);
     static final MethodHandle ENSURE_SPILL_SIZE = findOwnMH_V("ensureSpillSize", Object.class, int.class);
     /**
      * Constructor
      */
     public ScriptObject() {
         this(null);
     }
     /**
     * Constructor
     *
     * @param map {@link PropertyMap} used to create the initial object
     */
     public ScriptObject(final PropertyMap map) {
         if (Context.DEBUG) {
             ScriptObject.count++;
         }
         this.arrayData = ArrayData.EMPTY_ARRAY;
         this.setMap(map == null ? PropertyMap.newMap() : map);
     }
     /**
      * Constructor that directly sets the prototype to {@code proto} and property map to
      * {@code map} without invalidating the map as calling {@link #setProto(ScriptObject)}
      * would do. This should only be used for objects that are always constructed with the
      * same combination of prototype and property map.
      *
      * @param proto the prototype object
      * @param map intial {@link PropertyMap}
      */
     protected ScriptObject(final ScriptObject proto, final PropertyMap map) {
         this(map);
         this.proto = proto;
     }
     /**
      * Constructor used to instantiate spill properties directly. Used from
      * SpillObjectCreator.
      *
      * @param map            property maps
      * @param primitiveSpill primitive spills
      * @param objectSpill    reference spills
      */
     public ScriptObject(final PropertyMap map, final long[] primitiveSpill, final Object[] objectSpill) {
         this(map);
         this.primitiveSpill = primitiveSpill;
         this.objectSpill    = objectSpill;
         assert primitiveSpill.length == objectSpill.length : " primitive spill pool size is not the same length as object spill pool size";
         this.spillLength = spillAllocationLength(primitiveSpill.length);
     }
     /**
      * Check whether this is a global object
      * @return true if global
      */
     protected boolean isGlobal() {
         return false;
     }
     private static int alignUp(final int size, final int alignment) {
         return size + alignment - 1 & ~(alignment - 1);
     }
     /**
      * Given a number of properties, return the aligned to SPILL_RATE
      * buffer size required for the smallest spill pool needed to
      * house them
      * @param nProperties number of properties
      * @return property buffer length, a multiple of SPILL_RATE
      */
     public static int spillAllocationLength(final int nProperties) {
         return alignUp(nProperties, SPILL_RATE);
     }
     /**
      * Copy all properties from the source object with their receiver bound to the source.
      * This function was known as mergeMap
      *
      * @param source The source object to copy from.
      */
     public void addBoundProperties(final ScriptObject source) {
         addBoundProperties(source, source.getMap().getProperties());
     }
     /**
      * Copy all properties from the array with their receiver bound to the source.
      *
      * @param source The source object to copy from.
      * @param properties The array of properties to copy.
      */
     public void addBoundProperties(final ScriptObject source, final Property[] properties) {
         PropertyMap newMap = this.getMap();
         for (final Property property : properties) {
             final String key = property.getKey();
             final Property oldProp = newMap.findProperty(key);
             if (oldProp == null) {
                 if (property instanceof UserAccessorProperty) {
                     // Note: we copy accessor functions to this object which is semantically different from binding.
                     final UserAccessorProperty prop = this.newUserAccessors(key, property.getFlags(), property.getGetterFunction(source), property.getSetterFunction(source));
                     newMap = newMap.addPropertyNoHistory(prop);
                 } else {
                     newMap = newMap.addPropertyBind((AccessorProperty)property, source);
                 }
             } else {
                 // See ECMA section 10.5 Declaration Binding Instantiation
                 // step 5 processing each function declaration.
                 if (property.isFunctionDeclaration() && !oldProp.isConfigurable()) {
                      if (oldProp instanceof UserAccessorProperty ||
                          !(oldProp.isWritable() && oldProp.isEnumerable())) {
                          throw typeError("cant.redefine.property", key, ScriptRuntime.safeToString(this));
                      }
                 }
             }
         }
         this.setMap(newMap);
     }
     /**
      * Copy all properties from the array with their receiver bound to the source.
      *
      * @param source The source object to copy from.
      * @param properties The collection of accessor properties to copy.
      */
     public void addBoundProperties(final Object source, final AccessorProperty[] properties) {
         PropertyMap newMap = this.getMap();
         for (final AccessorProperty property : properties) {
             final String key = property.getKey();
             if (newMap.findProperty(key) == null) {
                 newMap = newMap.addPropertyBind(property, source);
             }
         }
         this.setMap(newMap);
     }
     /**
      * Bind the method handle to the specified receiver, while preserving its original type (it will just ignore the
      * first argument in lieu of the bound argument).
      * @param methodHandle Method handle to bind to.
      * @param receiver     Object to bind.
      * @return Bound method handle.
      */
     static MethodHandle bindTo(final MethodHandle methodHandle, final Object receiver) {
         return MH.dropArguments(MH.bindTo(methodHandle, receiver), 0, methodHandle.type().parameterType(0));
     }
     /**
      * Return a property iterator.
      * @return Property iterator.
      */
     public Iterator<String> propertyIterator() {
         return new KeyIterator(this);
     }
     /**
      * Return a property value iterator.
      * @return Property value iterator.
      */
     public Iterator<Object> valueIterator() {
         return new ValueIterator(this);
     }
     /**
      * ECMA 8.10.1 IsAccessorDescriptor ( Desc )
      * @return true if this has a {@link AccessorPropertyDescriptor} with a getter or a setter
      */
     public final boolean isAccessorDescriptor() {
         return has(GET) || has(SET);
     }
     /**
      * ECMA 8.10.2 IsDataDescriptor ( Desc )
      * @return true if this has a {@link DataPropertyDescriptor}, i.e. the object has a property value and is writable
      */
     public final boolean isDataDescriptor() {
         return has(VALUE) || has(WRITABLE);
     }
     /**
      * ECMA 8.10.3 IsGenericDescriptor ( Desc )
      * @return true if this has a descriptor describing an {@link AccessorPropertyDescriptor} or {@link DataPropertyDescriptor}
      */
     public final boolean isGenericDescriptor() {
         return isAccessorDescriptor() || isDataDescriptor();
     }
     /**
       * ECMA 8.10.5 ToPropertyDescriptor ( Obj )
       *
       * @return property descriptor
       */
     public final PropertyDescriptor toPropertyDescriptor() {
         final Global global = Context.getGlobal();
         final PropertyDescriptor desc;
         if (isDataDescriptor()) {
             if (has(SET) || has(GET)) {
                 throw typeError(global, "inconsistent.property.descriptor");
             }
             desc = global.newDataDescriptor(UNDEFINED, false, false, false);
         } else if (isAccessorDescriptor()) {
             if (has(VALUE) || has(WRITABLE)) {
                 throw typeError(global, "inconsistent.property.descriptor");
             }
             desc = global.newAccessorDescriptor(UNDEFINED, UNDEFINED, false, false);
         } else {
             desc = global.newGenericDescriptor(false, false);
         }
         return desc.fillFrom(this);
     }
     /**
      * ECMA 8.10.5 ToPropertyDescriptor ( Obj )
      *
      * @param global  global scope object
      * @param obj object to create property descriptor from
      *
      * @return property descriptor
      */
     public static PropertyDescriptor toPropertyDescriptor(final Global global, final Object obj) {
         if (obj instanceof ScriptObject) {
             return ((ScriptObject)obj).toPropertyDescriptor();
         }
         throw typeError(global, "not.an.object", ScriptRuntime.safeToString(obj));
     }
     /**
      * ECMA 8.12.1 [[GetOwnProperty]] (P)
      *
      * @param key property key
      *
      * @return Returns the Property Descriptor of the named own property of this
      * object, or undefined if absent.
      */
     public Object getOwnPropertyDescriptor(final String key) {
         final Property property = getMap().findProperty(key);
         final Global global = Context.getGlobal();
         if (property != null) {
             final ScriptFunction get   = property.getGetterFunction(this);
             final ScriptFunction set   = property.getSetterFunction(this);
             final boolean configurable = property.isConfigurable();
             final boolean enumerable   = property.isEnumerable();
             final boolean writable     = property.isWritable();
             if (property instanceof UserAccessorProperty) {
                 return global.newAccessorDescriptor(
                     get != null ?
                         get :
                         UNDEFINED,
                     set != null ?
                         set :
                         UNDEFINED,
                     configurable,
                     enumerable);
             }
             return global.newDataDescriptor(getWithProperty(property), configurable, enumerable, writable);
         }
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getDescriptor(global, index);
         }
         return UNDEFINED;
     }
     /**
      * ECMA 8.12.2 [[GetProperty]] (P)
      *
      * @param key property key
      *
      * @return Returns the fully populated Property Descriptor of the named property
      * of this object, or undefined if absent.
      */
     public Object getPropertyDescriptor(final String key) {
         final Object res = getOwnPropertyDescriptor(key);
         if (res != UNDEFINED) {
             return res;
         } else if (getProto() != null) {
             return getProto().getOwnPropertyDescriptor(key);
         } else {
             return UNDEFINED;
         }
     }
     /**
      * ECMA 8.12.9 [[DefineOwnProperty]] (P, Desc, Throw)
      *
      * @param key the property key
      * @param propertyDesc the property descriptor
      * @param reject is the property extensible - true means new definitions are rejected
      *
      * @return true if property was successfully defined
      */
     public boolean defineOwnProperty(final String key, final Object propertyDesc, final boolean reject) {
         final Global             global  = Context.getGlobal();
         final PropertyDescriptor desc    = toPropertyDescriptor(global, propertyDesc);
         final Object             current = getOwnPropertyDescriptor(key);
         final String             name    = JSType.toString(key);
         if (current == UNDEFINED) {
             if (isExtensible()) {
                 // add a new own property
                 addOwnProperty(key, desc);
                 return true;
             }
             // new property added to non-extensible object
             if (reject) {
                 throw typeError(global, "object.non.extensible", name, ScriptRuntime.safeToString(this));
             }
             return false;
         }
         // modifying an existing property
         final PropertyDescriptor currentDesc = (PropertyDescriptor)current;
         final PropertyDescriptor newDesc     = desc;
         if (newDesc.type() == PropertyDescriptor.GENERIC && !newDesc.has(CONFIGURABLE) && !newDesc.has(ENUMERABLE)) {
             // every descriptor field is absent
             return true;
         }
         if (newDesc.hasAndEquals(currentDesc)) {
             // every descriptor field of the new is same as the current
             return true;
         }
         if (!currentDesc.isConfigurable()) {
             if (newDesc.has(CONFIGURABLE) && newDesc.isConfigurable()) {
                 // not configurable can not be made configurable
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
             if (newDesc.has(ENUMERABLE) &&
                 currentDesc.isEnumerable() != newDesc.isEnumerable()) {
                 // cannot make non-enumerable as enumerable or vice-versa
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
         }
         int propFlags = Property.mergeFlags(currentDesc, newDesc);
         Property property = getMap().findProperty(key);
         if (currentDesc.type() == PropertyDescriptor.DATA &&
                 (newDesc.type() == PropertyDescriptor.DATA ||
                  newDesc.type() == PropertyDescriptor.GENERIC)) {
             if (!currentDesc.isConfigurable() && !currentDesc.isWritable()) {
                 if (newDesc.has(WRITABLE) && newDesc.isWritable() ||
                     newDesc.has(VALUE) && !ScriptRuntime.sameValue(currentDesc.getValue(), newDesc.getValue())) {
                     if (reject) {
                         throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                     }
                     return false;
                 }
             }
             final boolean newValue = newDesc.has(VALUE);
             final Object value     = newValue ? newDesc.getValue() : currentDesc.getValue();
             if (newValue && property != null) {
                 // Temporarily clear flags.
                 property = modifyOwnProperty(property, 0);
                 set(key, value, false);
                 //this might change the map if we change types of the property
                 //hence we need to read it again. note that we should probably
                 //have the setter return the new property throughout and in
                 //general respect Property return values from modify and add
                 //functions - which we don't seem to do at all here :-(
                 //There is already a bug filed to generify PropertyAccess so we
                 //can have the setter return e.g. a Property
                 property = getMap().findProperty(key);
             }
             if (property == null) {
                 // promoting an arrayData value to actual property
                 addOwnProperty(key, propFlags, value);
                 checkIntegerKey(key);
             } else {
                 // Now set the new flags
                 modifyOwnProperty(property, propFlags);
             }
         } else if (currentDesc.type() == PropertyDescriptor.ACCESSOR &&
                    (newDesc.type() == PropertyDescriptor.ACCESSOR ||
                     newDesc.type() == PropertyDescriptor.GENERIC)) {
             if (!currentDesc.isConfigurable()) {
                 if (newDesc.has(PropertyDescriptor.GET) && !ScriptRuntime.sameValue(currentDesc.getGetter(), newDesc.getGetter()) ||
                     newDesc.has(PropertyDescriptor.SET) && !ScriptRuntime.sameValue(currentDesc.getSetter(), newDesc.getSetter())) {
                     if (reject) {
                         throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                     }
                     return false;
                 }
             }
             // New set the new features.
             modifyOwnProperty(property, propFlags,
                                       newDesc.has(GET) ? newDesc.getGetter() : currentDesc.getGetter(),
                                       newDesc.has(SET) ? newDesc.getSetter() : currentDesc.getSetter());
         } else {
             // changing descriptor type
             if (!currentDesc.isConfigurable()) {
                 // not configurable can not be made configurable
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
             propFlags = 0;
             // Preserve only configurable and enumerable from current desc
             // if those are not overridden in the new property descriptor.
             boolean value = newDesc.has(CONFIGURABLE) ? newDesc.isConfigurable() : currentDesc.isConfigurable();
             if (!value) {
                 propFlags |= Property.NOT_CONFIGURABLE;
             }
             value = newDesc.has(ENUMERABLE)? newDesc.isEnumerable() : currentDesc.isEnumerable();
             if (!value) {
                 propFlags |= Property.NOT_ENUMERABLE;
             }
             final int type = newDesc.type();
             if (type == PropertyDescriptor.DATA) {
                 // get writable from the new descriptor
                 value = newDesc.has(WRITABLE) && newDesc.isWritable();
                 if (!value) {
                     propFlags |= Property.NOT_WRITABLE;
                 }
                 // delete the old property
                 deleteOwnProperty(property);
                 // add new data property
                 addOwnProperty(key, propFlags, newDesc.getValue());
             } else if (type == PropertyDescriptor.ACCESSOR) {
                 if (property == null) {
                     addOwnProperty(key, propFlags,
                                      newDesc.has(GET) ? newDesc.getGetter() : null,
                                      newDesc.has(SET) ? newDesc.getSetter() : null);
                 } else {
                     // Modify old property with the new features.
                     modifyOwnProperty(property, propFlags,
                                         newDesc.has(GET) ? newDesc.getGetter() : null,
                                         newDesc.has(SET) ? newDesc.getSetter() : null);
                 }
             }
         }
         checkIntegerKey(key);
         return true;
     }
     /**
      * Almost like defineOwnProperty(int,Object) for arrays this one does
      * not add 'gap' elements (like the array one does).
      *
      * @param index key for property
      * @param value value to define
      */
     public void defineOwnProperty(final int index, final Object value) {
         assert isValidArrayIndex(index) : "invalid array index";
         final long longIndex = ArrayIndex.toLongIndex(index);
         doesNotHaveEnsureDelete(longIndex, getArray().length(), false);
         setArray(getArray().ensure(longIndex));
         setArray(getArray().set(index, value, false));
     }
     private void checkIntegerKey(final String key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             final ArrayData data = getArray();
             if (data.has(index)) {
                 setArray(data.delete(index));
             }
         }
     }
     /**
       * Add a new property to the object.
       *
       * @param key          property key
       * @param propertyDesc property descriptor for property
       */
     public final void addOwnProperty(final String key, final PropertyDescriptor propertyDesc) {
         // Already checked that there is no own property with that key.
         PropertyDescriptor pdesc = propertyDesc;
         final int propFlags = Property.toFlags(pdesc);
         if (pdesc.type() == PropertyDescriptor.GENERIC) {
             final Global global = Context.getGlobal();
             final PropertyDescriptor dDesc = global.newDataDescriptor(UNDEFINED, false, false, false);
             dDesc.fillFrom((ScriptObject)pdesc);
             pdesc = dDesc;
         }
         final int type = pdesc.type();
         if (type == PropertyDescriptor.DATA) {
             addOwnProperty(key, propFlags, pdesc.getValue());
         } else if (type == PropertyDescriptor.ACCESSOR) {
             addOwnProperty(key, propFlags,
                     pdesc.has(GET) ? pdesc.getGetter() : null,
                     pdesc.has(SET) ? pdesc.getSetter() : null);
         }
         checkIntegerKey(key);
     }
     /**
      * Low level property API (not using property descriptors)
      * <p>
      * Find a property in the prototype hierarchy. Note: this is final and not
      * a good idea to override. If you have to, use
      * {jdk.nashorn.internal.objects.NativeArray{@link #getProperty(String)} or
      * {jdk.nashorn.internal.objects.NativeArray{@link #getPropertyDescriptor(String)} as the
      * overriding way to find array properties
      *
      * @see jdk.nashorn.internal.objects.NativeArray
      *
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      *
      * @return FindPropertyData or null if not found.
      */
     public final FindProperty findProperty(final String key, final boolean deep) {
         return findProperty(key, deep, false, this);
     }
     /**
      * Low level property API (not using property descriptors)
      * <p>
      * Find a property in the prototype hierarchy. Note: this is not a good idea
      * to override except as it was done in {@link WithObject}.
      * If you have to, use
      * {jdk.nashorn.internal.objects.NativeArray{@link #getProperty(String)} or
      * {jdk.nashorn.internal.objects.NativeArray{@link #getPropertyDescriptor(String)} as the
      * overriding way to find array properties
      *
      * @see jdk.nashorn.internal.objects.NativeArray
      *
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      * @param stopOnNonScope should a deep search stop on the first non-scope object?
      * @param start the object on which the lookup was originally initiated
      *
      * @return FindPropertyData or null if not found.
      */
     FindProperty findProperty(final String key, final boolean deep, final boolean stopOnNonScope, final ScriptObject start) {
         // if doing deep search, stop search on the first non-scope object if asked to do so
         if (stopOnNonScope && start != this && !isScope()) {
             return null;
         }
         final PropertyMap selfMap  = getMap();
         final Property    property = selfMap.findProperty(key);
         if (property != null) {
             return new FindProperty(start, this, property);
         }
         if (deep) {
             final ScriptObject myProto = getProto();
             if (myProto != null) {
                 return myProto.findProperty(key, deep, stopOnNonScope, start);
             }
         }
         return null;
     }
     /**
      * Low level property API. This is similar to {@link #findProperty(String, boolean)} but returns a
      * {@code boolean} value instead of a {@link FindProperty} object.
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      * @return true if the property was found.
      */
     boolean hasProperty(final String key, final boolean deep) {
         if (getMap().findProperty(key) != null) {
             return true;
         }
         if (deep) {
             final ScriptObject myProto = getProto();
             if (myProto != null) {
                 return myProto.hasProperty(key, deep);
             }
         }
         return false;
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param key             Property key.
      * @param propertyFlags   Property flags.
      * @param getter          Property getter, or null if not defined
      * @param setter          Property setter, or null if not defined
      *
      * @return New property.
      */
     public final Property addOwnProperty(final String key, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         return addOwnProperty(newUserAccessors(key, propertyFlags, getter, setter));
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param key             Property key.
      * @param propertyFlags   Property flags.
      * @param value           Value of property
      *
      * @return New property.
      */
     public final Property addOwnProperty(final String key, final int propertyFlags, final Object value) {
         return addSpillProperty(key, propertyFlags, value, true);
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param newProperty property to add
      *
      * @return New property.
      */
     public final Property addOwnProperty(final Property newProperty) {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.addProperty(newProperty);
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
                 final Property oldProperty = oldMap.findProperty(newProperty.getKey());
                 if (oldProperty != null) {
                     return oldProperty;
                 }
             } else {
                 return newProperty;
             }
         }
     }
     private void erasePropertyValue(final Property property) {
         // Erase the property field value with undefined. If the property is defined
         // by user-defined accessors, we don't want to call the setter!!
         if (!(property instanceof UserAccessorProperty)) {
             assert property != null;
             property.setValue(this, this, UNDEFINED, false);
         }
     }
     /**
      * Delete a property from the object.
      *
      * @param property Property to delete.
      *
      * @return true if deleted.
      */
     public final boolean deleteOwnProperty(final Property property) {
         erasePropertyValue(property);
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.deleteProperty(property);
             if (newMap == null) {
                 return false;
             }
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 // delete getter and setter function references so that we don't leak
                 if (property instanceof UserAccessorProperty) {
                     ((UserAccessorProperty)property).setAccessors(this, getMap(), null);
                 }
                 Global.getConstants().delete(property.getKey());
                 return true;
             }
         }
     }
     /**
      * Fast initialization functions for ScriptFunctions that are strict, to avoid
      * creating setters that probably aren't used. Inject directly into the spill pool
      * the defaults for "arguments" and "caller"
      *
      * @param key
      * @param propertyFlags
      * @param getter
      * @param setter
      */
     protected final void initUserAccessors(final String key, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         final int slot = spillLength;
         ensureSpillSize(spillLength); //arguments=slot0, caller=slot0
         objectSpill[slot] = new UserAccessorProperty.Accessors(getter, setter);
         final PropertyMap oldMap = getMap();
         Property    newProperty;
         PropertyMap newMap;
         do {
             newProperty = new UserAccessorProperty(key, propertyFlags, slot);
             newMap = oldMap.addProperty(newProperty);
         } while (!compareAndSetMap(oldMap, newMap));
     }
     /**
      * Modify a property in the object
      *
      * @param oldProperty    property to modify
      * @param propertyFlags  new property flags
      * @param getter         getter for {@link UserAccessorProperty}, null if not present or N/A
      * @param setter         setter for {@link UserAccessorProperty}, null if not present or N/A
      *
      * @return new property
      */
     public final Property modifyOwnProperty(final Property oldProperty, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         Property newProperty;
         if (oldProperty instanceof UserAccessorProperty) {
             final UserAccessorProperty uc = (UserAccessorProperty)oldProperty;
             final int slot = uc.getSlot();
             assert uc.getCurrentType() == Object.class;
             if (slot >= spillLength) {
                 uc.setAccessors(this, getMap(), new UserAccessorProperty.Accessors(getter, setter));
             } else {
                 final UserAccessorProperty.Accessors gs = uc.getAccessors(this); //this crashes
                 if (gs == null) {
                     uc.setAccessors(this, getMap(), new UserAccessorProperty.Accessors(getter, setter));
                 } else {
                     //reuse existing getter setter for speed
                     gs.set(getter, setter);
                     if (uc.getFlags() == propertyFlags) {
                         return oldProperty;
                     }
                 }
             }
             newProperty = new UserAccessorProperty(uc.getKey(), propertyFlags, slot);
         } else {
             // erase old property value and create new user accessor property
             erasePropertyValue(oldProperty);
             newProperty = newUserAccessors(oldProperty.getKey(), propertyFlags, getter, setter);
         }
         return modifyOwnProperty(oldProperty, newProperty);
     }
     /**
       * Modify a property in the object
       *
       * @param oldProperty    property to modify
       * @param propertyFlags  new property flags
       *
       * @return new property
       */
     public final Property modifyOwnProperty(final Property oldProperty, final int propertyFlags) {
         return modifyOwnProperty(oldProperty, oldProperty.setFlags(propertyFlags));
     }
     /**
      * Modify a property in the object, replacing a property with a new one
      *
      * @param oldProperty   property to replace
      * @param newProperty   property to replace it with
      *
      * @return new property
      */
     private Property modifyOwnProperty(final Property oldProperty, final Property newProperty) {
         if (oldProperty == newProperty) {
             return newProperty; //nop
         }
         assert newProperty.getKey().equals(oldProperty.getKey()) : "replacing property with different key";
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.replaceProperty(oldProperty, newProperty);
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
                 final Property oldPropertyLookup = oldMap.findProperty(oldProperty.getKey());
                 if (oldPropertyLookup != null && oldPropertyLookup.equals(newProperty)) {
                     return oldPropertyLookup;
                 }
             } else {
                 return newProperty;
             }
         }
     }
     /**
      * Update getter and setter in an object literal.
      *
      * @param key    Property key.
      * @param getter {@link UserAccessorProperty} defined getter, or null if none
      * @param setter {@link UserAccessorProperty} defined setter, or null if none
      */
     public final void setUserAccessors(final String key, final ScriptFunction getter, final ScriptFunction setter) {
         final Property oldProperty = getMap().findProperty(key);
         if (oldProperty instanceof UserAccessorProperty) {
             modifyOwnProperty(oldProperty, oldProperty.getFlags(), getter, setter);
         } else {
             addOwnProperty(newUserAccessors(key, oldProperty != null ? oldProperty.getFlags() : 0, getter, setter));
         }
     }
     private static int getIntValue(final FindProperty find, final int programPoint) {
         final MethodHandle getter = find.getGetter(int.class, programPoint, null);
         if (getter != null) {
             try {
                 return (int)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return UNDEFINED_INT;
     }
     private static long getLongValue(final FindProperty find, final int programPoint) {
         final MethodHandle getter = find.getGetter(long.class, programPoint, null);
         if (getter != null) {
             try {
                 return (long)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return UNDEFINED_LONG;
     }
     private static double getDoubleValue(final FindProperty find, final int programPoint) {
         final MethodHandle getter = find.getGetter(double.class, programPoint, null);
         if (getter != null) {
             try {
                 return (double)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return UNDEFINED_DOUBLE;
     }
     /**
      * Return methodHandle of value function for call.
      *
      * @param find      data from find property.
      * @param type      method type of function.
      * @param bindName  null or name to bind to second argument (property not found method.)
      *
      * @return value of property as a MethodHandle or null.
      */
     protected MethodHandle getCallMethodHandle(final FindProperty find, final MethodType type, final String bindName) {
         return getCallMethodHandle(find.getObjectValue(), type, bindName);
     }
     /**
      * Return methodHandle of value function for call.
      *
      * @param value     value of receiver, it not a {@link ScriptFunction} this will return null.
      * @param type      method type of function.
      * @param bindName  null or name to bind to second argument (property not found method.)
      *
      * @return value of property as a MethodHandle or null.
      */
     protected static MethodHandle getCallMethodHandle(final Object value, final MethodType type, final String bindName) {
         return value instanceof ScriptFunction ? ((ScriptFunction)value).getCallMethodHandle(type, bindName) : null;
     }
     /**
      * Get value using found property.
      *
      * @param property Found property.
      *
      * @return Value of property.
      */
     public final Object getWithProperty(final Property property) {
         return new FindProperty(this, this, property).getObjectValue();
     }
     /**
      * Get a property given a key
      *
      * @param key property key
      *
      * @return property for key
      */
     public final Property getProperty(final String key) {
         return getMap().findProperty(key);
     }
     /**
      * Overridden by {@link jdk.nashorn.internal.objects.NativeArguments} class (internal use.)
      * Used for argument access in a vararg function using parameter name.
      * Returns the argument at a given key (index)
      *
      * @param key argument index
      *
      * @return the argument at the given position, or undefined if not present
      */
     public Object getArgument(final int key) {
         return get(key);
     }
     /**
      * Overridden by {@link jdk.nashorn.internal.objects.NativeArguments} class (internal use.)
      * Used for argument access in a vararg function using parameter name.
      * Returns the argument at a given key (index)
      *
      * @param key   argument index
      * @param value the value to write at the given index
      */
     public void setArgument(final int key, final Object value) {
         set(key, value, false);
     }
     /**
      * Return the current context from the object's map.
      * @return Current context.
      */
     protected Context getContext() {
         return Context.fromClass(getClass());
     }
     /**
      * Return the map of an object.
      * @return PropertyMap object.
      */
     public final PropertyMap getMap() {
         return map;
     }
     /**
      * Set the initial map.
      * @param map Initial map.
      */
     public final void setMap(final PropertyMap map) {
         this.map = map;
     }
     /**
      * Conditionally set the new map if the old map is the same.
      * @param oldMap Map prior to manipulation.
      * @param newMap Replacement map.
      * @return true if the operation succeeded.
      */
     protected final boolean compareAndSetMap(final PropertyMap oldMap, final PropertyMap newMap) {
         if (oldMap == this.map) {
             this.map = newMap;
             return true;
         }
         return false;
      }
     /**
      * Return the __proto__ of an object.
      * @return __proto__ object.
      */
     public final ScriptObject getProto() {
         return proto;
     }
     /**
      * Get the proto of a specific depth
      * @param n depth
      * @return proto at given depth
      */
     public final ScriptObject getProto(final int n) {
         assert n > 0;
         ScriptObject p = getProto();
         for (int i = n; i-- > 0;) {
             p = p.getProto();
         }
         return p;
     }
     /**
      * Set the __proto__ of an object.
      * @param newProto new __proto__ to set.
      */
     public final void setProto(final ScriptObject newProto) {
         final ScriptObject oldProto = proto;
         if (oldProto != newProto) {
             proto = newProto;
             // Let current listeners know that the protototype has changed and set our map
             final PropertyListeners listeners = getMap().getListeners();
             if (listeners != null) {
                 listeners.protoChanged();
             }
             // Replace our current allocator map with one that is associated with the new prototype.
             setMap(getMap().changeProto(newProto));
         }
     }
     /**
      * Set the initial __proto__ of this object. This should be used instead of
      * {@link #setProto} if it is known that the current property map will not be
      * used on a new object with any other parent property map, so we can pass over
      * property map invalidation/evolution.
      *
      * @param initialProto the initial __proto__ to set.
      */
     public void setInitialProto(final ScriptObject initialProto) {
         this.proto = initialProto;
     }
     /**
      * Invoked from generated bytecode to initialize the prototype of object literals to the global Object prototype.
      * @param obj the object literal that needs to have its prototype initialized to the global Object prototype.
      */
     public static void setGlobalObjectProto(final ScriptObject obj) {
         obj.setInitialProto(Global.objectPrototype());
     }
     /**
      * Set the __proto__ of an object with checks.
      * This is the built-in operation [[SetPrototypeOf]]
      * See ES6 draft spec: 9.1.2 [[SetPrototypeOf]] (V)
      *
      * @param newProto Prototype to set.
      */
     public final void setPrototypeOf(final Object newProto) {
         if (newProto == null || newProto instanceof ScriptObject) {
             if (! isExtensible()) {
                 // okay to set same proto again - even if non-extensible
                 if (newProto == getProto()) {
                     return;
                 }
                 throw typeError("__proto__.set.non.extensible", ScriptRuntime.safeToString(this));
             }
             // check for circularity
             ScriptObject p = (ScriptObject)newProto;
             while (p != null) {
                 if (p == this) {
                     throw typeError("circular.__proto__.set", ScriptRuntime.safeToString(this));
                 }
                 p = p.getProto();
             }
             setProto((ScriptObject)newProto);
         } else {
             throw typeError("cant.set.proto.to.non.object", ScriptRuntime.safeToString(this), ScriptRuntime.safeToString(newProto));
         }
     }
     /**
      * Set the __proto__ of an object from an object literal.
      * See ES6 draft spec: B.3.1 __proto__ Property Names in
      * Object Initializers. Step 6 handling of "__proto__".
      *
      * @param newProto Prototype to set.
      */
     public final void setProtoFromLiteral(final Object newProto) {
         if (newProto == null || newProto instanceof ScriptObject) {
             setPrototypeOf(newProto);
         } else {
             // Some non-object, non-null. Then, we need to set
             // Object.prototype as the new __proto__
             //
             // var obj = { __proto__ : 34 };
             // print(obj.__proto__ === Object.prototype); // => true
             setPrototypeOf(Global.objectPrototype());
         }
     }
     /**
      * return an array of own property keys associated with the object.
      *
      * @param all True if to include non-enumerable keys.
      * @return Array of keys.
      */
     public final String[] getOwnKeys(final boolean all) {
         return getOwnKeys(all, null);
     }
     /**
      * return an array of own property keys associated with the object.
      *
      * @param all True if to include non-enumerable keys.
      * @param nonEnumerable set of non-enumerable properties seen already.Used
        to filter out shadowed, but enumerable properties from proto children.
      * @return Array of keys.
      */
     protected String[] getOwnKeys(final boolean all, final Set<String> nonEnumerable) {
         final List<Object> keys    = new ArrayList<>();
         final PropertyMap  selfMap = this.getMap();
         final ArrayData array  = getArray();
         final long length      = array.length();
         for (long i = 0; i < length; i = array.nextIndex(i)) {
             if (array.has((int)i)) {
                 keys.add(JSType.toString(i));
             }
         }
         for (final Property property : selfMap.getProperties()) {
             final boolean enumerable = property.isEnumerable();
             final String key = property.getKey();
             if (all) {
                 keys.add(key);
             } else if (enumerable) {
                 // either we don't have non-enumerable filter set or filter set
                 // does not contain the current property.
                 if (nonEnumerable == null || !nonEnumerable.contains(key)) {
                     keys.add(key);
                 }
             } else {
                 // store this non-enumerable property for later proto walk
                 if (nonEnumerable != null) {
                     nonEnumerable.add(key);
                 }
             }
         }
         return keys.toArray(new String[keys.size()]);
     }
     /**
      * Check if this ScriptObject has array entries. This means that someone has
      * set values with numeric keys in the object.
      *
      * @return true if array entries exists.
      */
     public boolean hasArrayEntries() {
         return getArray().length() > 0 || getMap().containsArrayKeys();
     }
     /**
      * Return the valid JavaScript type name descriptor
      *
      * @return "Object"
      */
     public String getClassName() {
         return "Object";
     }
     /**
      * {@code length} is a well known property. This is its getter.
      * Note that this *may* be optimized by other classes
      *
      * @return length property value for this ScriptObject
      */
     public Object getLength() {
         return get("length");
     }
     /**
      * Stateless toString for ScriptObjects.
      *
      * @return string description of this object, e.g. {@code [object Object]}
      */
     public String safeToString() {
         return "[object " + getClassName() + "]";
     }
     /**
      * Return the default value of the object with a given preferred type hint.
      * The preferred type hints are String.class for type String, Number.class
      * for type Number. <p>
      *
      * A <code>hint</code> of null means "no hint".
      *
      * ECMA 8.12.8 [[DefaultValue]](hint)
      *
      * @param typeHint the preferred type hint
      * @return the default value
      */
     public Object getDefaultValue(final Class<?> typeHint) {
         // We delegate to Global, as the implementation uses dynamic call sites to invoke object's "toString" and
         // "valueOf" methods, and in order to avoid those call sites from becoming megamorphic when multiple contexts
         // are being executed in a long-running program, we move the code and their associated dynamic call sites
         // (Global.TO_STRING and Global.VALUE_OF) into per-context code.
         return Context.getGlobal().getDefaultValue(this, typeHint);
     }
     /**
      * Checking whether a script object is an instance of another. Used
      * in {@link ScriptFunction} for hasInstance implementation, walks
      * the proto chain
      *
      * @param instance instace to check
      * @return true if 'instance' is an instance of this object
      */
     public boolean isInstance(final ScriptObject instance) {
         return false;
     }
     /**
      * Flag this ScriptObject as non extensible
      *
      * @return the object after being made non extensible
      */
     public ScriptObject preventExtensions() {
         PropertyMap oldMap = getMap();
         while (!compareAndSetMap(oldMap,  getMap().preventExtensions())) {
             oldMap = getMap();
         }
         //invalidate any fast array setters
         final ArrayData array = getArray();
         if (array != null) {
             array.invalidateSetters();
         }
         return this;
     }
     /**
      * Check whether if an Object (not just a ScriptObject) represents JavaScript array
      *
      * @param obj object to check
      *
      * @return true if array
      */
     public static boolean isArray(final Object obj) {
         return obj instanceof ScriptObject && ((ScriptObject)obj).isArray();
     }
     /**
      * Check if this ScriptObject is an array
      * @return true if array
      */
     public final boolean isArray() {
         return (flags & IS_ARRAY) != 0;
     }
     /**
      * Flag this ScriptObject as being an array
      */
     public final void setIsArray() {
         flags |= IS_ARRAY;
     }
     /**
      * Check if this ScriptObject is an {@code arguments} vector
      * @return true if arguments vector
      */
     public final boolean isArguments() {
         return (flags & IS_ARGUMENTS) != 0;
     }
     /**
      * Flag this ScriptObject as being an {@code arguments} vector
      */
     public final void setIsArguments() {
         flags |= IS_ARGUMENTS;
     }
     /**
      * Check if this object has non-writable length property
      *
      * @return {@code true} if 'length' property is non-writable
      */
     public final boolean isLengthNotWritable() {
         return (flags & IS_LENGTH_NOT_WRITABLE) != 0;
     }
     /**
      * Flag this object as having non-writable length property
      */
     public void setIsLengthNotWritable() {
         flags |= IS_LENGTH_NOT_WRITABLE;
     }
     /**
      * Get the {@link ArrayData} for this ScriptObject if it is an array
      * @return array data
      */
     public final ArrayData getArray() {
         return arrayData;
     }
     /**
      * Set the {@link ArrayData} for this ScriptObject if it is to be an array
      * @param arrayData the array data
      */
     public final void setArray(final ArrayData arrayData) {
         this.arrayData = arrayData;
     }
     /**
      * Check if this ScriptObject is extensible
      * @return true if extensible
      */
     public boolean isExtensible() {
         return getMap().isExtensible();
     }
     /**
      * ECMAScript 15.2.3.8 - seal implementation
      * @return the sealed ScriptObject
      */
     public ScriptObject seal() {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = getMap().seal();
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 setArray(ArrayData.seal(getArray()));
                 return this;
             }
         }
     }
     /**
      * Check whether this ScriptObject is sealed
      * @return true if sealed
      */
     public boolean isSealed() {
         return getMap().isSealed();
     }
     /**
      * ECMA 15.2.39 - freeze implementation. Freeze this ScriptObject
      * @return the frozen ScriptObject
      */
     public ScriptObject freeze() {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = getMap().freeze();
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 setArray(ArrayData.freeze(getArray()));
                 return this;
             }
         }
     }
     /**
      * Check whether this ScriptObject is frozen
      * @return true if frozen
      */
     public boolean isFrozen() {
         return getMap().isFrozen();
     }
     /**
      * Flag this ScriptObject as scope
      */
     public final void setIsScope() {
         if (Context.DEBUG) {
             scopeCount++;
         }
         flags |= IS_SCOPE;
     }
     /**
      * Check whether this ScriptObject is scope
      * @return true if scope
      */
     public final boolean isScope() {
         return (flags & IS_SCOPE) != 0;
     }
     /**
      * Tag this script object as built in
      */
     public final void setIsBuiltin() {
         flags |= IS_BUILTIN;
     }
     /**
      * Check if this script object is built in
      * @return true if build in
      */
     public final boolean isBuiltin() {
         return (flags & IS_BUILTIN) != 0;
     }
     /**
      * Clears the properties from a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param strict strict mode or not
      */
     public void clear(final boolean strict) {
         final Iterator<String> iter = propertyIterator();
         while (iter.hasNext()) {
             delete(iter.next(), strict);
         }
     }
     /**
      * Checks if a property with a given key is present in a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key the key to check for
      * @return true if a property with the given key exists, false otherwise
      */
     public boolean containsKey(final Object key) {
         return has(key);
     }
     /**
      * Checks if a property with a given value is present in a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param value value to check for
      * @return true if a property with the given value exists, false otherwise
      */
     public boolean containsValue(final Object value) {
         final Iterator<Object> iter = valueIterator();
         while (iter.hasNext()) {
             if (iter.next().equals(value)) {
                 return true;
             }
         }
         return false;
     }
     /**
      * Returns the set of {@literal <property, value>} entries that make up this
      * ScriptObject's properties
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return an entry set of all the properties in this object
      */
     public Set<Map.Entry<Object, Object>> entrySet() {
         final Iterator<String> iter = propertyIterator();
         final Set<Map.Entry<Object, Object>> entries = new HashSet<>();
         while (iter.hasNext()) {
             final Object key = iter.next();
             entries.add(new AbstractMap.SimpleImmutableEntry<>(key, get(key)));
         }
         return Collections.unmodifiableSet(entries);
     }
     /**
      * Check whether a ScriptObject contains no properties
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return true if object has no properties
      */
     public boolean isEmpty() {
         return !propertyIterator().hasNext();
     }
     /**
      * Return the set of keys (property names) for all properties
      * in this ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return keySet of this ScriptObject
      */
     public Set<Object> keySet() {
         final Iterator<String> iter = propertyIterator();
         final Set<Object> keySet = new HashSet<>();
         while (iter.hasNext()) {
             keySet.add(iter.next());
         }
         return Collections.unmodifiableSet(keySet);
     }
     /**
      * Put a property in the ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key property key
      * @param value property value
      * @param strict strict mode or not
      * @return oldValue if property with same key existed already
      */
     public Object put(final Object key, final Object value, final boolean strict) {
         final Object oldValue = get(key);
         set(key, value, strict);
         return oldValue;
     }
     /**
      * Put several properties in the ScriptObject given a mapping
      * of their keys to their values
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param otherMap a {@literal <key,value>} map of properties to add
      * @param strict strict mode or not
      */
     public void putAll(final Map<?, ?> otherMap, final boolean strict) {
         for (final Map.Entry<?, ?> entry : otherMap.entrySet()) {
             set(entry.getKey(), entry.getValue(), strict);
         }
     }
     /**
      * Remove a property from the ScriptObject.
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key the key of the property
      * @param strict strict mode or not
      * @return the oldValue of the removed property
      */
     public Object remove(final Object key, final boolean strict) {
         final Object oldValue = get(key);
         delete(key, strict);
         return oldValue;
     }
     /**
      * Return the size of the ScriptObject - i.e. the number of properties
      * it contains
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return number of properties in ScriptObject
      */
     public int size() {
         int n = 0;
         for (final Iterator<String> iter = propertyIterator(); iter.hasNext(); iter.next()) {
             n++;
         }
         return n;
     }
     /**
      * Return the values of the properties in the ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return collection of values for the properties in this ScriptObject
      */
     public Collection<Object> values() {
         final List<Object>     values = new ArrayList<>(size());
         final Iterator<Object> iter   = valueIterator();
         while (iter.hasNext()) {
             values.add(iter.next());
         }
         return Collections.unmodifiableList(values);
     }
     /**
      * Lookup method that, given a CallSiteDescriptor, looks up the target
      * MethodHandle and creates a GuardedInvocation
      * with the appropriate guard(s).
      *
      * @param desc call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation for the callsite
      */
     public GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request) {
         final int c = desc.getNameTokenCount();
         // JavaScript is "immune" to all currently defined Dynalink composite operation - getProp is the same as getElem
         // is the same as getMethod as JavaScript objects have a single namespace for all three. Therefore, we don't
         // care about them, and just link to whatever is the first operation.
         final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
         // NOTE: we support getElem and setItem as JavaScript doesn't distinguish items from properties. Nashorn itself
         // emits "dyn:getProp:identifier" for "<expr>.<identifier>" and "dyn:getElem" for "<expr>[<expr>]", but we are
         // more flexible here and dispatch not on operation name (getProp vs. getElem), but rather on whether the
         // operation has an associated name or not.
         switch (operator) {
         case "getProp":
         case "getElem":
         case "getMethod":
             return c > 2 ? findGetMethod(desc, request, operator) : findGetIndexMethod(desc, request);
         case "setProp":
         case "setElem":
             return c > 2 ? findSetMethod(desc, request) : findSetIndexMethod(desc, request);
         case "call":
             return findCallMethod(desc, request);
         case "new":
             return findNewMethod(desc, request);
         case "callMethod":
             return findCallMethodMethod(desc, request);
         default:
             return null;
         }
     }
     /**
      * Find the appropriate New method for an invoke dynamic call.
      *
      * @param desc The invoke dynamic call site descriptor.
      * @param request The link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findNewMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         return notAFunction();
     }
     /**
      * Find the appropriate CALL method for an invoke dynamic call.
      * This generates "not a function" always
      *
      * @param desc    the call site descriptor.
      * @param request the link request
      *
      * @return GuardedInvocation to be invoed at call site.
      */
     protected GuardedInvocation findCallMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         return notAFunction();
     }
     private GuardedInvocation notAFunction() {
         throw typeError("not.a.function", ScriptRuntime.safeToString(this));
     }
     /**
      * Find an implementation for a "dyn:callMethod" operation. Note that Nashorn internally never uses
      * "dyn:callMethod", but instead always emits two call sites in bytecode, one for "dyn:getMethod", and then another
      * one for "dyn:call". Explicit support for "dyn:callMethod" is provided for the benefit of potential external
      * callers. The implementation itself actually folds a "dyn:getMethod" method handle into a "dyn:call" method handle.
      *
      * @param desc    the call site descriptor.
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findCallMethodMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         // R(P0, P1, ...)
         final MethodType callType = desc.getMethodType();
         // use type Object(P0) for the getter
         final CallSiteDescriptor getterType = desc.changeMethodType(MethodType.methodType(Object.class, callType.parameterType(0)));
         final GuardedInvocation getter = findGetMethod(getterType, request, "getMethod");
         // Object(P0) => Object(P0, P1, ...)
         final MethodHandle argDroppingGetter = MH.dropArguments(getter.getInvocation(), 1, callType.parameterList().subList(1, callType.parameterCount()));
         // R(Object, P0, P1, ...)
         final MethodHandle invoker = Bootstrap.createDynamicInvoker("dyn:call", callType.insertParameterTypes(0, argDroppingGetter.type().returnType()));
         // Fold Object(P0, P1, ...) into R(Object, P0, P1, ...) => R(P0, P1, ...)
         return getter.replaceMethods(MH.foldArguments(invoker, argDroppingGetter), getter.getGuard());
     }
     /**
      * Test whether this object contains in its prototype chain or is itself a with-object.
      * @return true if a with-object was found
      */
     final boolean hasWithScope() {
         if (isScope()) {
             for (ScriptObject obj = this; obj != null; obj = obj.getProto()) {
                 if (obj instanceof WithObject) {
                     return true;
                 }
             }
         }
         return false;
     }
     /**
      * Add a filter to the first argument of {@code methodHandle} that calls its {@link #getProto()} method
      * {@code depth} times.
      * @param methodHandle a method handle
      * @param depth        distance to target prototype
      * @return the filtered method handle
      */
     static MethodHandle addProtoFilter(final MethodHandle methodHandle, final int depth) {
         if (depth == 0) {
             return methodHandle;
         }
         final int listIndex = depth - 1; // We don't need 0-deep walker
         MethodHandle filter = listIndex < PROTO_FILTERS.size() ? PROTO_FILTERS.get(listIndex) : null;
         if (filter == null) {
             filter = addProtoFilter(GETPROTO, depth - 1);
             PROTO_FILTERS.add(null);
             PROTO_FILTERS.set(listIndex, filter);
         }
         return MH.filterArguments(methodHandle, 0, filter.asType(filter.type().changeReturnType(methodHandle.type().parameterType(0))));
     }
     //this will only return true if apply is still builtin
     private static SwitchPoint checkReservedName(final CallSiteDescriptor desc, final LinkRequest request) {
         final boolean isApplyToCall = NashornCallSiteDescriptor.isApplyToCall(desc);
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         if ("apply".equals(name) && isApplyToCall && Global.instance().isSpecialNameValid(name)) {
             assert Global.instance().getChangeCallback("apply") == Global.instance().getChangeCallback("call");
             return Global.instance().getChangeCallback("apply");
         }
         return null;
     }
     /**
      * Find the appropriate GET method for an invoke dynamic call.
      *
      * @param desc     the call site descriptor
      * @param request  the link request
      * @param operator operator for get: getProp, getMethod, getElem etc
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operator) {
         final boolean explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);
         final String name;
         final SwitchPoint reservedNameSwitchPoint;
         reservedNameSwitchPoint = checkReservedName(desc, request);
         if (reservedNameSwitchPoint != null) {
             name = "call"; //turn apply into call, it is the builtin apply and has been modified to explode args
         } else {
             name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         }
         if (request.isCallSiteUnstable() || hasWithScope()) {
             return findMegaMorphicGetMethod(desc, name, "getMethod".equals(operator));
         }
         final FindProperty find = findProperty(name, true);
         MethodHandle mh;
         if (find == null) {
             switch (operator) {
             case "getProp":
                 return noSuchProperty(desc, request);
             case "getMethod":
                 return noSuchMethod(desc, request);
             case "getElem":
                 return createEmptyGetter(desc, explicitInstanceOfCheck, name);
             default:
                 throw new AssertionError(operator); // never invoked with any other operation
             }
         }
         final GuardedInvocation cinv = Global.getConstants().findGetMethod(find, this, desc, request, operator);
         if (cinv != null) {
             return cinv;
         }
         final Class<?> returnType = desc.getMethodType().returnType();
         final Property property   = find.getProperty();
         final int programPoint = NashornCallSiteDescriptor.isOptimistic(desc) ?
                 NashornCallSiteDescriptor.getProgramPoint(desc) :
                 UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
         mh = find.getGetter(returnType, programPoint, request);
         // Get the appropriate guard for this callsite and property.
         final MethodHandle guard = NashornGuards.getGuard(this, property, desc, explicitInstanceOfCheck);
         final ScriptObject owner = find.getOwner();
         final Class<ClassCastException> exception = explicitInstanceOfCheck ? null : ClassCastException.class;
         final SwitchPoint protoSwitchPoint;
         if (mh == null) {
             mh = Lookup.emptyGetter(returnType);
             protoSwitchPoint = getProtoSwitchPoint(name, owner);
         } else if (!find.isSelf()) {
             assert mh.type().returnType().equals(returnType) :
                     "return type mismatch for getter " + mh.type().returnType() + " != " + returnType;
             if (!(property instanceof UserAccessorProperty)) {
                 // Add a filter that replaces the self object with the prototype owning the property.
                 mh = addProtoFilter(mh, find.getProtoChainLength());
             }
             protoSwitchPoint = getProtoSwitchPoint(name, owner);
         } else {
             protoSwitchPoint = null;
         }
         assert OBJECT_FIELDS_ONLY || guard != null : "we always need a map guard here";
         final GuardedInvocation inv = new GuardedInvocation(mh, guard, protoSwitchPoint, exception);
         return inv.addSwitchPoint(reservedNameSwitchPoint);
     }
     private static GuardedInvocation findMegaMorphicGetMethod(final CallSiteDescriptor desc, final String name, final boolean isMethod) {
         Context.getContextTrusted().getLogger(ObjectClassGenerator.class).warning("Megamorphic getter: " + desc + " " + name + " " +isMethod);
         final MethodHandle invoker = MH.insertArguments(MEGAMORPHIC_GET, 1, name, isMethod);
         final MethodHandle guard   = getScriptObjectGuard(desc.getMethodType(), true);
         return new GuardedInvocation(invoker, guard);
     }
     @SuppressWarnings("unused")
     private Object megamorphicGet(final String key, final boolean isMethod) {
         final FindProperty find = findProperty(key, true);
         if (find != null) {
             return find.getObjectValue();
         }
         return isMethod ? getNoSuchMethod(key, INVALID_PROGRAM_POINT) : invokeNoSuchProperty(key, INVALID_PROGRAM_POINT);
     }
     // Marks a property as declared and sets its value. Used as slow path for block-scoped LET and CONST
     @SuppressWarnings("unused")
     private void declareAndSet(final String key, final Object value) {
         final PropertyMap map = getMap();
         final FindProperty find = findProperty(key, false);
         assert find != null;
         final Property property = find.getProperty();
         assert property != null;
         assert property.needsDeclaration();
         final PropertyMap newMap = map.replaceProperty(property, property.removeFlags(Property.NEEDS_DECLARATION));
         setMap(newMap);
         set(key, value, true);
     }
     /**
      * Find the appropriate GETINDEX method for an invoke dynamic call.
      *
      * @param desc    the call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         final MethodType callType                = desc.getMethodType();
         final Class<?>   returnType              = callType.returnType();
         final Class<?>   returnClass             = returnType.isPrimitive() ? returnType : Object.class;
         final Class<?>   keyClass                = callType.parameterType(1);
         final boolean    explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);
         final String name;
         if (returnClass.isPrimitive()) {
             //turn e.g. get with a double into getDouble
             final String returnTypeName = returnClass.getName();
             name = "get" + Character.toUpperCase(returnTypeName.charAt(0)) + returnTypeName.substring(1, returnTypeName.length());
         } else {
             name = "get";
         }
         final MethodHandle mh = findGetIndexMethodHandle(returnClass, name, keyClass, desc);
         return new GuardedInvocation(mh, getScriptObjectGuard(callType, explicitInstanceOfCheck), (SwitchPoint)null, explicitInstanceOfCheck ? null : ClassCastException.class);
     }
     private static MethodHandle getScriptObjectGuard(final MethodType type, final boolean explicitInstanceOfCheck) {
         return ScriptObject.class.isAssignableFrom(type.parameterType(0)) ? null : NashornGuards.getScriptObjectGuard(explicitInstanceOfCheck);
     }
     /**
      * Find a handle for a getIndex method
      * @param returnType     return type for getter
      * @param name           name
      * @param elementType    index type for getter
      * @param desc           call site descriptor
      * @return method handle for getter
      */
     protected MethodHandle findGetIndexMethodHandle(final Class<?> returnType, final String name, final Class<?> elementType, final CallSiteDescriptor desc) {
         if (!returnType.isPrimitive()) {
             return findOwnMH_V(getClass(), name, returnType, elementType);
         }
         return MH.insertArguments(
                 findOwnMH_V(getClass(), name, returnType, elementType, int.class),
 ,
                 NashornCallSiteDescriptor.isOptimistic(desc) ?
                         NashornCallSiteDescriptor.getProgramPoint(desc) :
                         INVALID_PROGRAM_POINT);
     }
     /**
      * Get a switch point for a property with the given {@code name} that will be invalidated when
      * the property definition is changed in this object's prototype chain. Returns {@code null} if
      * the property is defined in this object itself.
      *
      * @param name the property name
      * @param owner the property owner, null if property is not defined
      * @return a SwitchPoint or null
      */
     public final SwitchPoint getProtoSwitchPoint(final String name, final ScriptObject owner) {
         if (owner == this || getProto() == null) {
             return null;
         }
         for (ScriptObject obj = this; obj != owner && obj.getProto() != null; obj = obj.getProto()) {
             final ScriptObject parent = obj.getProto();
             parent.getMap().addListener(name, obj.getMap());
         }
         return getMap().getSwitchPoint(name);
     }
     /**
      * Find the appropriate SET method for an invoke dynamic call.
      *
      * @param desc    the call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         if (request.isCallSiteUnstable() || hasWithScope()) {
             return findMegaMorphicSetMethod(desc, name);
         }
         final boolean scope                   = isScope();
         final boolean explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);
         /*
          * If doing property set on a scope object, we should stop proto search on the first
          * non-scope object. Without this, for example, when assigning "toString" on global scope,
          * we'll end up assigning it on it's proto - which is Object.prototype.toString !!
          *
          * toString = function() { print("global toString"); } // don't affect Object.prototype.toString
          */
         FindProperty find = findProperty(name, true, scope, this);
         // If it's not a scope search, then we don't want any inherited properties except those with user defined accessors.
         if (!scope && find != null && find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) {
             // We should still check if inherited data property is not writable
             if (isExtensible() && !find.getProperty().isWritable()) {
                 return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", false);
             }
             // Otherwise, forget the found property
             find = null;
         }
         if (find != null) {
             if (!find.getProperty().isWritable() && !NashornCallSiteDescriptor.isDeclaration(desc)) {
                 // Existing, non-writable property
                 return createEmptySetMethod(desc, explicitInstanceOfCheck, "property.not.writable", true);
             }
         } else {
             if (!isExtensible()) {
                 return createEmptySetMethod(desc, explicitInstanceOfCheck, "object.non.extensible", false);
             }
         }
         final GuardedInvocation inv = new SetMethodCreator(this, find, desc, request).createGuardedInvocation();
         final GuardedInvocation cinv = Global.getConstants().findSetMethod(find, this, inv, desc, request);
         if (cinv != null) {
             return cinv;
         }
         return inv;
     }
     private GuardedInvocation createEmptySetMethod(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String strictErrorMessage, final boolean canBeFastScope) {
         final String  name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
          if (NashornCallSiteDescriptor.isStrict(desc)) {
            throw typeError(strictErrorMessage, name, ScriptRuntime.safeToString(this));
         }
         assert canBeFastScope || !NashornCallSiteDescriptor.isFastScope(desc);
         return new GuardedInvocation(
                 Lookup.EMPTY_SETTER,
                 NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck),
                 getProtoSwitchPoint(name, null),
                 explicitInstanceOfCheck ? null : ClassCastException.class);
     }
     @SuppressWarnings("unused")
     private boolean extensionCheck(final boolean isStrict, final String name) {
         if (isExtensible()) {
             return true; //go on and do the set. this is our guard
         } else if (isStrict) {
             //throw an error for attempting to do the set in strict mode
             throw typeError("object.non.extensible", name, ScriptRuntime.safeToString(this));
         } else {
             //not extensible, non strict - this is a nop
             return false;
         }
     }
     private GuardedInvocation findMegaMorphicSetMethod(final CallSiteDescriptor desc, final String name) {
         final MethodType        type = desc.getMethodType().insertParameterTypes(1, Object.class);
         //never bother with ClassCastExceptionGuard for megamorphic callsites
         final GuardedInvocation inv = findSetIndexMethod(getClass(), false, type, NashornCallSiteDescriptor.isStrict(desc));
         return inv.replaceMethods(MH.insertArguments(inv.getInvocation(), 1, name), inv.getGuard());
     }
     @SuppressWarnings("unused")
     private static Object globalFilter(final Object object) {
         ScriptObject sobj = (ScriptObject) object;
         while (sobj != null && !(sobj instanceof Global)) {
             sobj = sobj.getProto();
         }
         return sobj;
     }
     /**
      * Lookup function for the set index method, available for subclasses as well, e.g. {@link NativeArray}
      * provides special quick accessor linkage for continuous arrays that are represented as Java arrays
      *
      * @param desc    call site descriptor
      * @param request link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findSetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) { // array, index, value
         return findSetIndexMethod(getClass(), explicitInstanceOfCheck(desc, request), desc.getMethodType(), NashornCallSiteDescriptor.isStrict(desc));
     }
     /**
      * Find the appropriate SETINDEX method for an invoke dynamic call.
      *
      * @param callType the method type at the call site
      * @param isStrict are we in strict mode?
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     private static GuardedInvocation findSetIndexMethod(final Class<? extends ScriptObject> clazz, final boolean explicitInstanceOfCheck, final MethodType callType, final boolean isStrict) {
         assert callType.parameterCount() == 3;
         final Class<?> keyClass   = callType.parameterType(1);
         final Class<?> valueClass = callType.parameterType(2);
         MethodHandle methodHandle = findOwnMH_V(clazz, "set", void.class, keyClass, valueClass, boolean.class);
         methodHandle = MH.insertArguments(methodHandle, 3, isStrict);
         return new GuardedInvocation(methodHandle, getScriptObjectGuard(callType, explicitInstanceOfCheck), (SwitchPoint)null, explicitInstanceOfCheck ? null : ClassCastException.class);
     }
     /**
      * Fall back if a function property is not found.
      * @param desc The call site descriptor
      * @param request the link request
      * @return GuardedInvocation to be invoked at call site.
      */
     public GuardedInvocation noSuchMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         final String       name      = desc.getNameToken(2);
         final FindProperty find      = findProperty(NO_SUCH_METHOD_NAME, true);
         final boolean      scopeCall = isScope() && NashornCallSiteDescriptor.isScope(desc);
         if (find == null) {
             return noSuchProperty(desc, request);
         }
         final boolean explicitInstanceOfCheck = explicitInstanceOfCheck(desc, request);
         final Object value = find.getObjectValue();
         if (!(value instanceof ScriptFunction)) {
             return createEmptyGetter(desc, explicitInstanceOfCheck, name);
         }
         final ScriptFunction func = (ScriptFunction)value;
         final Object         thiz = scopeCall && func.isStrict() ? ScriptRuntime.UNDEFINED : this;
         // TODO: It'd be awesome if we could bind "name" without binding "this".
         return new GuardedInvocation(
                 MH.dropArguments(
                         MH.constant(
                                 ScriptFunction.class,
                                 func.makeBoundFunction(thiz, new Object[] { name })),
 ,
                         Object.class),
                 NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck),
                 (SwitchPoint)null,
                 explicitInstanceOfCheck ? null : ClassCastException.class);
     }
     /**
      * Fall back if a property is not found.
      * @param desc the call site descriptor.
      * @param request the link request
      * @return GuardedInvocation to be invoked at call site.
      */
     public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
         final String       name        = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         final FindProperty find        = findProperty(NO_SUCH_PROPERTY_NAME, true);
         final boolean      scopeAccess = isScope() && NashornCallSiteDescriptor.isScope(desc);
         if (find != null) {
             final Object   value = find.getObjectValue();
             ScriptFunction func  = null;
             MethodHandle   mh    = null;
             if (value instanceof ScriptFunction) {
                 func = (ScriptFunction)value;
                 mh   = getCallMethodHandle(func, desc.getMethodType(), name);
             }
             if (mh != null) {
                 assert func != null;
                 if (scopeAccess && func.isStrict()) {
                     mh = bindTo(mh, UNDEFINED);
                 }
                 return new GuardedInvocation(
                         mh,
                         find.isSelf()?
                             getKnownFunctionPropertyGuardSelf(
                                 getMap(),
                                 find.getGetter(Object.class, INVALID_PROGRAM_POINT, request),
                                 func)
                             :
                             //TODO this always does a scriptobject check
                             getKnownFunctionPropertyGuardProto(
                                 getMap(),
                                 find.getGetter(Object.class, INVALID_PROGRAM_POINT, request),
                                 find.getProtoChainLength(),
                                 func),
                         getProtoSwitchPoint(NO_SUCH_PROPERTY_NAME, find.getOwner()),
                         //TODO this doesn't need a ClassCastException as guard always checks script object
                         null);
             }
         }
         if (scopeAccess) {
             throw referenceError("not.defined", name);
         }
         return createEmptyGetter(desc, explicitInstanceOfCheck(desc, request), name);
     }
     /**
      * Invoke fall back if a property is not found.
      * @param name Name of property.
      * @param programPoint program point
      * @return Result from call.
      */
     protected Object invokeNoSuchProperty(final String name, final int programPoint) {
         final FindProperty find = findProperty(NO_SUCH_PROPERTY_NAME, true);
         Object ret = UNDEFINED;
         if (find != null) {
             final Object func = find.getObjectValue();
             if (func instanceof ScriptFunction) {
                 ret = ScriptRuntime.apply((ScriptFunction)func, this, name);
             }
         }
         if (isValid(programPoint)) {
             throw new UnwarrantedOptimismException(ret, programPoint);
         }
         return ret;
     }
     /**
      * Get __noSuchMethod__ as a function bound to this object and {@code name} if it is defined.
      * @param name the method name
      * @return the bound function, or undefined
      */
     private Object getNoSuchMethod(final String name, final int programPoint) {
         final FindProperty find = findProperty(NO_SUCH_METHOD_NAME, true);
         if (find == null) {
             return invokeNoSuchProperty(name, programPoint);
         }
         final Object value = find.getObjectValue();
         if (!(value instanceof ScriptFunction)) {
             return UNDEFINED;
         }
         return ((ScriptFunction)value).makeBoundFunction(this, new Object[] {name});
     }
     private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
         if (NashornCallSiteDescriptor.isOptimistic(desc)) {
             throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
         }
         return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
                 NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoint(name, null),
                 explicitInstanceOfCheck ? null : ClassCastException.class);
     }
     private abstract static class ScriptObjectIterator <T extends Object> implements Iterator<T> {
         protected T[] values;
         protected final ScriptObject object;
         private int index;
         ScriptObjectIterator(final ScriptObject object) {
             this.object = object;
         }
         protected abstract void init();
         @Override
         public boolean hasNext() {
             if (values == null) {
                 init();
             }
             return index < values.length;
         }
         @Override
         public T next() {
             if (values == null) {
                 init();
             }
             return values[index++];
         }
         @Override
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
     private static class KeyIterator extends ScriptObjectIterator<String> {
         KeyIterator(final ScriptObject object) {
             super(object);
         }
         @Override
         protected void init() {
             final Set<String> keys = new LinkedHashSet<>();
             final Set<String> nonEnumerable = new HashSet<>();
             for (ScriptObject self = object; self != null; self = self.getProto()) {
                 keys.addAll(Arrays.asList(self.getOwnKeys(false, nonEnumerable)));
             }
             this.values = keys.toArray(new String[keys.size()]);
         }
     }
     private static class ValueIterator extends ScriptObjectIterator<Object> {
         ValueIterator(final ScriptObject object) {
             super(object);
         }
         @Override
         protected void init() {
             final ArrayList<Object> valueList = new ArrayList<>();
             final Set<String> nonEnumerable = new HashSet<>();
             for (ScriptObject self = object; self != null; self = self.getProto()) {
                 for (final String key : self.getOwnKeys(false, nonEnumerable)) {
                     valueList.add(self.get(key));
                 }
             }
             this.values = valueList.toArray(new Object[valueList.size()]);
         }
     }
     /**
      * Add a spill property for the given key.
      * @param key           Property key.
      * @param propertyFlags Property flags.
      * @return Added property.
      */
     private Property addSpillProperty(final String key, final int propertyFlags, final Object value, final boolean hasInitialValue) {
         final PropertyMap propertyMap = getMap();
         final int fieldSlot  = propertyMap.getFreeFieldSlot();
         Property property;
         if (fieldSlot > -1) {
             property = hasInitialValue ?
                 new AccessorProperty(key, propertyFlags, fieldSlot, this, value) :
                 new AccessorProperty(key, propertyFlags, getClass(), fieldSlot);
             property = addOwnProperty(property);
         } else {
             final int spillSlot = propertyMap.getFreeSpillSlot();
             property = hasInitialValue ?
                 new SpillProperty(key, propertyFlags, spillSlot, this, value) :
                 new SpillProperty(key, propertyFlags, spillSlot);
             property = addOwnProperty(property);
             ensureSpillSize(property.getSlot());
         }
         return property;
     }
     /**
      * Add a spill entry for the given key.
      * @param key Property key.
      * @return Setter method handle.
      */
     MethodHandle addSpill(final Class<?> type, final String key) {
         return addSpillProperty(key, 0, null, false).getSetter(OBJECT_FIELDS_ONLY ? Object.class : type, getMap());
     }
     /**
      * Make sure arguments are paired correctly, with respect to more parameters than declared,
      * fewer parameters than declared and other things that JavaScript allows. This might involve
      * creating collectors.
      *
      * @param methodHandle method handle for invoke
      * @param callType     type of the call
      *
      * @return method handle with adjusted arguments
      */
     protected static MethodHandle pairArguments(final MethodHandle methodHandle, final MethodType callType) {
         return pairArguments(methodHandle, callType, null);
     }
     /**
      * Make sure arguments are paired correctly, with respect to more parameters than declared,
      * fewer parameters than declared and other things that JavaScript allows. This might involve
      * creating collectors.
      *
      * Make sure arguments are paired correctly.
      * @param methodHandle MethodHandle to adjust.
      * @param callType     MethodType of the call site.
      * @param callerVarArg true if the caller is vararg, false otherwise, null if it should be inferred from the
      * {@code callType}; basically, if the last parameter type of the call site is an array, it'll be considered a
      * variable arity call site. These are ordinarily rare; Nashorn code generator creates variable arity call sites
      * when the call has more than {@link LinkerCallSite#ARGLIMIT} parameters.
      *
      * @return method handle with adjusted arguments
      */
     public static MethodHandle pairArguments(final MethodHandle methodHandle, final MethodType callType, final Boolean callerVarArg) {
         final MethodType methodType = methodHandle.type();
         if (methodType.equals(callType.changeReturnType(methodType.returnType()))) {
             return methodHandle;
         }
         final int parameterCount = methodType.parameterCount();
         final int callCount      = callType.parameterCount();
         final boolean isCalleeVarArg = parameterCount > 0 && methodType.parameterType(parameterCount - 1).isArray();
         final boolean isCallerVarArg = callerVarArg != null ? callerVarArg.booleanValue() : callCount > 0 &&
                 callType.parameterType(callCount - 1).isArray();
         if (isCalleeVarArg) {
             return isCallerVarArg ?
                 methodHandle :
                 MH.asCollector(methodHandle, Object[].class, callCount - parameterCount + 1);
         }
         if (isCallerVarArg) {
             return adaptHandleToVarArgCallSite(methodHandle, callCount);
         }
         if (callCount < parameterCount) {
             final int      missingArgs = parameterCount - callCount;
             final Object[] fillers     = new Object[missingArgs];
             Arrays.fill(fillers, UNDEFINED);
             if (isCalleeVarArg) {
                 fillers[missingArgs - 1] = ScriptRuntime.EMPTY_ARRAY;
             }
             return MH.insertArguments(
                 methodHandle,
                 parameterCount - missingArgs,
                 fillers);
         }
         if (callCount > parameterCount) {
             final int discardedArgs = callCount - parameterCount;
             final Class<?>[] discards = new Class<?>[discardedArgs];
             Arrays.fill(discards, Object.class);
             return MH.dropArguments(methodHandle, callCount - discardedArgs, discards);
         }
         return methodHandle;
     }
     static MethodHandle adaptHandleToVarArgCallSite(final MethodHandle mh, final int callSiteParamCount) {
         final int spreadArgs = mh.type().parameterCount() - callSiteParamCount + 1;
         return MH.filterArguments(
             MH.asSpreader(
             mh,
             Object[].class,
             spreadArgs),
             callSiteParamCount - 1,
             MH.insertArguments(
                 TRUNCATINGFILTER,
 ,
                 spreadArgs)
             );
     }
     @SuppressWarnings("unused")
     private static Object[] truncatingFilter(final int n, final Object[] array) {
         final int length = array == null ? 0 : array.length;
         if (n == length) {
             return array == null ? ScriptRuntime.EMPTY_ARRAY : array;
         }
         final Object[] newArray = new Object[n];
         if (array != null) {
             System.arraycopy(array, 0, newArray, 0, Math.min(n, length));
         }
         if (length < n) {
             final Object fill = UNDEFINED;
             for (int i = length; i < n; i++) {
                 newArray[i] = fill;
             }
         }
         return newArray;
     }
     /**
       * Numeric length setter for length property
       *
       * @param newLength new length to set
       */
     public final void setLength(final long newLength) {
        final long arrayLength = getArray().length();
        if (newLength == arrayLength) {
            return;
        }
        if (newLength > arrayLength) {
            setArray(getArray().ensure(newLength - 1));
             if (getArray().canDelete(arrayLength, newLength - 1, false)) {
                setArray(getArray().delete(arrayLength, newLength - 1));
            }
            return;
        }
        if (newLength < arrayLength) {
            long actualLength = newLength;
            // Check for numeric keys in property map and delete them or adjust length, depending on whether
            // they're defined as configurable. See ES5 #15.4.5.2
            if (getMap().containsArrayKeys()) {
                for (long l = arrayLength - 1; l >= newLength; l--) {
                    final FindProperty find = findProperty(JSType.toString(l), false);
                    if (find != null) {
                        if (find.getProperty().isConfigurable()) {
                            deleteOwnProperty(find.getProperty());
                        } else {
                            actualLength = l + 1;
                            break;
                        }
                    }
                }
            }
            setArray(getArray().shrink(actualLength));
            getArray().setLength(actualLength);
        }
     }
     private int getInt(final int index, final String key, final int programPoint) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 if (object.getMap().containsArrayKeys()) {
                     final FindProperty find = object.findProperty(key, false, false, this);
                     if (find != null) {
                         return getIntValue(find, programPoint);
                     }
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return isValid(programPoint) ?
                         array.getIntOptimistic(index, programPoint) :
                         array.getInt(index);
                 }
             }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getIntValue(find, programPoint);
             }
         }
         return JSType.toInt32(invokeNoSuchProperty(key, programPoint));
     }
     @Override
     public int getInt(final Object key, final int programPoint) {
         final Object    primitiveKey = JSType.toPrimitive(key, String.class);
         final int       index        = getArrayIndex(primitiveKey);
         final ArrayData array        = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getIntOptimistic(index, programPoint) : array.getInt(index);
         }
         return getInt(index, JSType.toString(primitiveKey), programPoint);
     }
     @Override
     public int getInt(final double key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getIntOptimistic(index, programPoint) : array.getInt(index);
         }
         return getInt(index, JSType.toString(key), programPoint);
     }
     @Override
     public int getInt(final long key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getIntOptimistic(index, programPoint) : array.getInt(index);
         }
         return getInt(index, JSType.toString(key), programPoint);
     }
     @Override
     public int getInt(final int key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getIntOptimistic(key, programPoint) : array.getInt(key);
         }
         return getInt(index, JSType.toString(key), programPoint);
     }
     private long getLong(final int index, final String key, final int programPoint) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 if (object.getMap().containsArrayKeys()) {
                     final FindProperty find = object.findProperty(key, false, false, this);
                     if (find != null) {
                         return getLongValue(find, programPoint);
                     }
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return isValid(programPoint) ?
                         array.getLongOptimistic(index, programPoint) :
                         array.getLong(index);
                 }
             }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getLongValue(find, programPoint);
             }
         }
         return JSType.toLong(invokeNoSuchProperty(key, programPoint));
     }
     @Override
     public long getLong(final Object key, final int programPoint) {
         final Object    primitiveKey = JSType.toPrimitive(key, String.class);
         final int       index        = getArrayIndex(primitiveKey);
         final ArrayData array        = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getLongOptimistic(index, programPoint) : array.getLong(index);
         }
         return getLong(index, JSType.toString(primitiveKey), programPoint);
     }
     @Override
     public long getLong(final double key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getLongOptimistic(index, programPoint) : array.getLong(index);
         }
         return getLong(index, JSType.toString(key), programPoint);
     }
     @Override
     public long getLong(final long key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getLongOptimistic(index, programPoint) : array.getLong(index);
         }
         return getLong(index, JSType.toString(key), programPoint);
     }
     @Override
     public long getLong(final int key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getLongOptimistic(key, programPoint) : array.getLong(key);
         }
         return getLong(index, JSType.toString(key), programPoint);
     }
     private double getDouble(final int index, final String key, final int programPoint) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 if (object.getMap().containsArrayKeys()) {
                     final FindProperty find = object.findProperty(key, false, false, this);
                     if (find != null) {
                         return getDoubleValue(find, programPoint);
                     }
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return isValid(programPoint) ?
                         array.getDoubleOptimistic(index, programPoint) :
                         array.getDouble(index);
                 }
             }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getDoubleValue(find, programPoint);
             }
         }
         return JSType.toNumber(invokeNoSuchProperty(key, INVALID_PROGRAM_POINT));
     }
     @Override
     public double getDouble(final Object key, final int programPoint) {
         final Object    primitiveKey = JSType.toPrimitive(key, String.class);
         final int       index        = getArrayIndex(primitiveKey);
         final ArrayData array        = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getDoubleOptimistic(index, programPoint) : array.getDouble(index);
         }
         return getDouble(index, JSType.toString(primitiveKey), programPoint);
     }
     @Override
     public double getDouble(final double key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getDoubleOptimistic(index, programPoint) : array.getDouble(index);
         }
         return getDouble(index, JSType.toString(key), programPoint);
     }
     @Override
     public double getDouble(final long key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getDoubleOptimistic(index, programPoint) : array.getDouble(index);
         }
         return getDouble(index, JSType.toString(key), programPoint);
     }
     @Override
     public double getDouble(final int key, final int programPoint) {
         final int       index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return isValid(programPoint) ? array.getDoubleOptimistic(key, programPoint) : array.getDouble(key);
         }
         return getDouble(index, JSType.toString(key), programPoint);
     }
     private Object get(final int index, final String key) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 if (object.getMap().containsArrayKeys()) {
                     final FindProperty find = object.findProperty(key, false, false, this);
                     if (find != null) {
                         return find.getObjectValue();
                     }
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return array.getObject(index);
                 }
             }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return find.getObjectValue();
             }
         }
         return invokeNoSuchProperty(key, INVALID_PROGRAM_POINT);
     }
     @Override
     public Object get(final Object key) {
         final Object    primitiveKey = JSType.toPrimitive(key, String.class);
         final int       index        = getArrayIndex(primitiveKey);
         final ArrayData array        = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(primitiveKey));
     }
     @Override
     public Object get(final double key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     @Override
     public Object get(final long key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     @Override
     public Object get(final int key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     private boolean doesNotHaveCheckArrayKeys(final long longIndex, final int value, final boolean strict) {
         if (getMap().containsArrayKeys()) {
             final String       key  = JSType.toString(longIndex);
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 setObject(find, strict, key, value);
                 return true;
             }
         }
         return false;
     }
     private boolean doesNotHaveCheckArrayKeys(final long longIndex, final long value, final boolean strict) {
         if (getMap().containsArrayKeys()) {
             final String       key  = JSType.toString(longIndex);
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 setObject(find, strict, key, value);
                 return true;
             }
         }
         return false;
     }
     private boolean doesNotHaveCheckArrayKeys(final long longIndex, final double value, final boolean strict) {
          if (getMap().containsArrayKeys()) {
             final String       key  = JSType.toString(longIndex);
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 setObject(find, strict, key, value);
                 return true;
             }
         }
         return false;
     }
     private boolean doesNotHaveCheckArrayKeys(final long longIndex, final Object value, final boolean strict) {
         if (getMap().containsArrayKeys()) {
             final String       key  = JSType.toString(longIndex);
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 setObject(find, strict, key, value);
                 return true;
             }
         }
         return false;
     }
     //value agnostic
     private boolean doesNotHaveEnsureLength(final long longIndex, final long oldLength, final boolean strict) {
         if (longIndex >= oldLength) {
             if (!isExtensible()) {
                 if (strict) {
                     throw typeError("object.non.extensible", JSType.toString(longIndex), ScriptRuntime.safeToString(this));
                 }
                 return true;
             }
             setArray(getArray().ensure(longIndex));
         }
         return false;
     }
     private void doesNotHaveEnsureDelete(final long longIndex, final long oldLength, final boolean strict) {
         if (longIndex > oldLength) {
             ArrayData array = getArray();
             if (array.canDelete(oldLength, longIndex - 1, strict)) {
                 array = array.delete(oldLength, longIndex - 1);
             }
             setArray(array);
         }
     }
     private void doesNotHave(final int index, final int value, final boolean strict) {
         final long oldLength = getArray().length();
         final long longIndex = ArrayIndex.toLongIndex(index);
         if (!doesNotHaveCheckArrayKeys(longIndex, value, strict) && !doesNotHaveEnsureLength(longIndex, oldLength, strict)) {
             setArray(getArray().set(index, value, strict));
             doesNotHaveEnsureDelete(longIndex, oldLength, strict);
         }
     }
     private void doesNotHave(final int index, final long value, final boolean strict) {
         final long oldLength = getArray().length();
         final long longIndex = ArrayIndex.toLongIndex(index);
         if (!doesNotHaveCheckArrayKeys(longIndex, value, strict) && !doesNotHaveEnsureLength(longIndex, oldLength, strict)) {
             setArray(getArray().set(index, value, strict));
             doesNotHaveEnsureDelete(longIndex, oldLength, strict);
         }
     }
     private void doesNotHave(final int index, final double value, final boolean strict) {
         final long oldLength = getArray().length();
         final long longIndex = ArrayIndex.toLongIndex(index);
         if (!doesNotHaveCheckArrayKeys(longIndex, value, strict) && !doesNotHaveEnsureLength(longIndex, oldLength, strict)) {
             setArray(getArray().set(index, value, strict));
             doesNotHaveEnsureDelete(longIndex, oldLength, strict);
         }
     }
     private void doesNotHave(final int index, final Object value, final boolean strict) {
         final long oldLength = getArray().length();
         final long longIndex = ArrayIndex.toLongIndex(index);
         if (!doesNotHaveCheckArrayKeys(longIndex, value, strict) && !doesNotHaveEnsureLength(longIndex, oldLength, strict)) {
             setArray(getArray().set(index, value, strict));
             doesNotHaveEnsureDelete(longIndex, oldLength, strict);
         }
     }
     /**
      * This is the most generic of all Object setters. Most of the others use this in some form.
      * TODO: should be further specialized
      *
      * @param find    found property
      * @param strict  are we in strict mode
      * @param key     property key
      * @param value   property value
      */
     public final void setObject(final FindProperty find, final boolean strict, final String key, final Object value) {
         FindProperty f = find;
         if (f != null && f.isInherited() && !(f.getProperty() instanceof UserAccessorProperty) && !isScope()) {
             // Setting a property should not modify the property in prototype unless this is a scope object.
             f = null;
         }
         if (f != null) {
             if (!f.getProperty().isWritable()) {
                 if (strict) {
                     throw typeError("property.not.writable", key, ScriptRuntime.safeToString(this));
                 }
                 return;
             }
             f.setValue(value, strict);
         } else if (!isExtensible()) {
             if (strict) {
                 throw typeError("object.non.extensible", key, ScriptRuntime.safeToString(this));
             }
         } else {
             ScriptObject sobj = this;
             // undefined scope properties are set in the global object.
             if (isScope()) {
                 while (sobj != null && !(sobj instanceof Global)) {
                     sobj = sobj.getProto();
                 }
                 assert sobj != null : "no parent global object in scope";
             }
             //this will unbox any Number object to its primitive type in case the
             //property supports primitive types, so it doesn't matter that it comes
             //in as an Object.
             sobj.addSpillProperty(key, 0, value, true);
         }
     }
     @Override
     public void set(final Object key, final int value, final boolean strict) {
         final Object primitiveKey = JSType.toPrimitive(key, String.class);
         final int    index        = getArrayIndex(primitiveKey);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(primitiveKey);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final long value, final boolean strict) {
         final Object primitiveKey = JSType.toPrimitive(key, String.class);
         final int    index        = getArrayIndex(primitiveKey);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(primitiveKey);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final double value, final boolean strict) {
         final Object primitiveKey = JSType.toPrimitive(key, String.class);
         final int    index        = getArrayIndex(primitiveKey);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(primitiveKey);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final Object value, final boolean strict) {
         final Object primitiveKey = JSType.toPrimitive(key, String.class);
         final int    index        = getArrayIndex(primitiveKey);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(primitiveKey);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final double key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final long key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final int key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public boolean has(final Object key) {
         final Object primitiveKey = JSType.toPrimitive(key);
         final int    index        = getArrayIndex(primitiveKey);
         return isValidArrayIndex(index) ? hasArrayProperty(index) : hasProperty(JSType.toString(primitiveKey), true);
     }
     @Override
     public boolean has(final double key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasArrayProperty(index) : hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean has(final long key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasArrayProperty(index) : hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean has(final int key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasArrayProperty(index) : hasProperty(JSType.toString(key), true);
     }
     private boolean hasArrayProperty(final int index) {
         boolean hasArrayKeys = false;
         for (ScriptObject self = this; self != null; self = self.getProto()) {
             if (self.getArray().has(index)) {
                 return true;
             }
             hasArrayKeys = hasArrayKeys || self.getMap().containsArrayKeys();
         }
         return hasArrayKeys && hasProperty(ArrayIndex.toKey(index), true);
     }
     @Override
     public boolean hasOwnProperty(final Object key) {
         final Object primitiveKey = JSType.toPrimitive(key, String.class);
         final int    index        = getArrayIndex(primitiveKey);
         return isValidArrayIndex(index) ? hasOwnArrayProperty(index) : hasProperty(JSType.toString(primitiveKey), false);
     }
     @Override
     public boolean hasOwnProperty(final int key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasOwnArrayProperty(index) : hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean hasOwnProperty(final long key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasOwnArrayProperty(index) : hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean hasOwnProperty(final double key) {
         final int index = getArrayIndex(key);
         return isValidArrayIndex(index) ? hasOwnArrayProperty(index) : hasProperty(JSType.toString(key), false);
     }
     private boolean hasOwnArrayProperty(final int index) {
         return getArray().has(index) || getMap().containsArrayKeys() && hasProperty(ArrayIndex.toKey(index), false);
     }
     @Override
     public boolean delete(final int key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final long key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final double key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final Object key, final boolean strict) {
         final Object    primitiveKey = JSType.toPrimitive(key, String.class);
         final int       index        = getArrayIndex(primitiveKey);
         final ArrayData array        = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(primitiveKey, strict);
     }
     private boolean deleteObject(final Object key, final boolean strict) {
         final String propName = JSType.toString(key);
         final FindProperty find = findProperty(propName, false);
         if (find == null) {
             return true;
         }
         if (!find.getProperty().isConfigurable()) {
             if (strict) {
                 throw typeError("cant.delete.property", propName, ScriptRuntime.safeToString(this));
             }
             return false;
         }
         final Property prop = find.getProperty();
         deleteOwnProperty(prop);
         return true;
     }
     /**
      * Make a new UserAccessorProperty property. getter and setter functions are stored in
      * this ScriptObject and slot values are used in property object.
      *
      * @param key the property name
      * @param propertyFlags attribute flags of the property
      * @param getter getter function for the property
      * @param setter setter function for the property
      * @return the newly created UserAccessorProperty
      */
     protected final UserAccessorProperty newUserAccessors(final String key, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         final UserAccessorProperty uc = getMap().newUserAccessors(key, propertyFlags);
         //property.getSetter(Object.class, getMap());
         uc.setAccessors(this, getMap(), new UserAccessorProperty.Accessors(getter, setter));
         return uc;
     }
     Object ensureSpillSize(final int slot) {
         if (slot < spillLength) {
             return this;
         }
         final int newLength = alignUp(slot + 1, SPILL_RATE);
         final Object[] newObjectSpill    = new Object[newLength];
         final long[]   newPrimitiveSpill = OBJECT_FIELDS_ONLY ? null : new long[newLength];
         if (objectSpill != null) {
             System.arraycopy(objectSpill, 0, newObjectSpill, 0, spillLength);
             if (!OBJECT_FIELDS_ONLY) {
                 System.arraycopy(primitiveSpill, 0, newPrimitiveSpill, 0, spillLength);
             }
         }
         this.primitiveSpill = newPrimitiveSpill;
         this.objectSpill    = newObjectSpill;
         this.spillLength = newLength;
         return this;
     }
     private static MethodHandle findOwnMH_V(final Class<? extends ScriptObject> clazz, final String name, final Class<?> rtype, final Class<?>... types) {
         // TODO: figure out how can it work for NativeArray$Prototype etc.
         return MH.findVirtual(MethodHandles.lookup(), ScriptObject.class, name, MH.type(rtype, types));
     }
     private static MethodHandle findOwnMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
         return findOwnMH_V(ScriptObject.class, name, rtype, types);
     }
     private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
         return MH.findStatic(MethodHandles.lookup(), ScriptObject.class, name, MH.type(rtype, types));
     }
     private static MethodHandle getKnownFunctionPropertyGuardSelf(final PropertyMap map, final MethodHandle getter, final ScriptFunction func) {
         return MH.insertArguments(KNOWNFUNCPROPGUARDSELF, 1, map, getter, func);
     }
     @SuppressWarnings("unused")
     private static boolean knownFunctionPropertyGuardSelf(final Object self, final PropertyMap map, final MethodHandle getter, final ScriptFunction func) {
         if (self instanceof ScriptObject && ((ScriptObject)self).getMap() == map) {
             try {
                 return getter.invokeExact(self) == func;
             } catch (final RuntimeException | Error e) {
                 throw e;
             } catch (final Throwable t) {
                 throw new RuntimeException(t);
             }
         }
         return false;
     }
     private static MethodHandle getKnownFunctionPropertyGuardProto(final PropertyMap map, final MethodHandle getter, final int depth, final ScriptFunction func) {
         return MH.insertArguments(KNOWNFUNCPROPGUARDPROTO, 1, map, getter, depth, func);
     }
     private static ScriptObject getProto(final ScriptObject self, final int depth) {
         ScriptObject proto = self;
         for (int d = 0; d < depth; d++) {
             proto = proto.getProto();
             if (proto == null) {
                 return null;
             }
         }
         return proto;
     }
     @SuppressWarnings("unused")
     private static boolean knownFunctionPropertyGuardProto(final Object self, final PropertyMap map, final MethodHandle getter, final int depth, final ScriptFunction func) {
         if (self instanceof ScriptObject && ((ScriptObject)self).getMap() == map) {
             final ScriptObject proto = getProto((ScriptObject)self, depth);
             if (proto == null) {
                 return false;
             }
             try {
                 return getter.invokeExact((Object)proto) == func;
             } catch (final RuntimeException | Error e) {
                 throw e;
             } catch (final Throwable t) {
                 throw new RuntimeException(t);
             }
         }
         return false;
     }
     /** This is updated only in debug mode - counts number of {@code ScriptObject} instances created */
     private static int count;
     /** This is updated only in debug mode - counts number of {@code ScriptObject} instances created that are scope */
     private static int scopeCount;
     /**
      * Get number of {@code ScriptObject} instances created. If not running in debug
      * mode this is always 0
      *
      * @return number of ScriptObjects created
      */
     public static int getCount() {
         return count;
     }
     /**
      * Get number of scope {@code ScriptObject} instances created. If not running in debug
      * mode this is always 0
      *
      * @return number of scope ScriptObjects created
      */
     public static int getScopeCount() {
         return scopeCount;
     }
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/runtime/ScriptObject.java@e94bfa3c6c6c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java