| /* |
| * 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.objects; |
| |
| import static jdk.nashorn.internal.lookup.Lookup.MH; |
| import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; |
| import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; |
| |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.BitSet; |
| import jdk.nashorn.internal.runtime.AccessorProperty; |
| import jdk.nashorn.internal.runtime.JSType; |
| import jdk.nashorn.internal.runtime.Property; |
| import jdk.nashorn.internal.runtime.PropertyDescriptor; |
| import jdk.nashorn.internal.runtime.PropertyMap; |
| import jdk.nashorn.internal.runtime.ScriptFunction; |
| import jdk.nashorn.internal.runtime.ScriptObject; |
| import jdk.nashorn.internal.runtime.ScriptRuntime; |
| import jdk.nashorn.internal.runtime.arrays.ArrayData; |
| import jdk.nashorn.internal.runtime.arrays.ArrayIndex; |
| |
| /** |
| * ECMA 10.6 Arguments Object. |
| * |
| * Arguments object used for non-strict mode functions. For strict mode, we use |
| * a different implementation (@see NativeStrictArguments). In non-strict mode, |
| * named argument access and index argument access (arguments[i]) are linked. |
| * Modifications reflect on each other access -- till arguments indexed element |
| * is deleted. After delete, there is no link between named access and indexed |
| * access for that deleted index alone. |
| */ |
| public final class NativeArguments extends ScriptObject { |
| |
| private static final MethodHandle G$LENGTH = findOwnMH("G$length", Object.class, Object.class); |
| private static final MethodHandle S$LENGTH = findOwnMH("S$length", void.class, Object.class, Object.class); |
| private static final MethodHandle G$CALLEE = findOwnMH("G$callee", Object.class, Object.class); |
| private static final MethodHandle S$CALLEE = findOwnMH("S$callee", void.class, Object.class, Object.class); |
| |
| private static final PropertyMap map$; |
| |
| static { |
| final ArrayList<Property> properties = new ArrayList<>(2); |
| properties.add(AccessorProperty.create("length", Property.NOT_ENUMERABLE, G$LENGTH, S$LENGTH)); |
| properties.add(AccessorProperty.create("callee", Property.NOT_ENUMERABLE, G$CALLEE, S$CALLEE)); |
| map$ = PropertyMap.newMap(properties); |
| } |
| |
| static PropertyMap getInitialMap() { |
| return map$; |
| } |
| |
| private Object length; |
| private Object callee; |
| private final int numMapped; |
| private final int numParams; |
| |
| // These are lazily initialized when delete is invoked on a mapped arg or an unmapped argument is set. |
| private ArrayData unmappedArgs; |
| private BitSet deleted; |
| |
| NativeArguments(final Object[] arguments, final Object callee, final int numParams, final ScriptObject proto, final PropertyMap map) { |
| super(proto, map); |
| setIsArguments(); |
| setArray(ArrayData.allocate(arguments)); |
| this.length = arguments.length; |
| this.callee = callee; |
| this.numMapped = Math.min(numParams, arguments.length); |
| this.numParams = numParams; |
| } |
| |
| @Override |
| public String getClassName() { |
| return "Arguments"; |
| } |
| |
| /** |
| * getArgument is used for named argument access. |
| */ |
| @Override |
| public Object getArgument(final int key) { |
| assert key >= 0 && key < numParams : "invalid argument index"; |
| return isMapped(key) ? getArray().getObject(key) : getUnmappedArg(key); |
| } |
| |
| /** |
| * setArgument is used for named argument set. |
| */ |
| @Override |
| public void setArgument(final int key, final Object value) { |
| assert key >= 0 && key < numParams : "invalid argument index"; |
| if (isMapped(key)) { |
| setArray(getArray().set(key, value, false)); |
| } else { |
| setUnmappedArg(key, value); |
| } |
| } |
| |
| @Override |
| public boolean delete(final int key, final boolean strict) { |
| final int index = ArrayIndex.getArrayIndex(key); |
| return isMapped(index) ? deleteMapped(index, strict) : super.delete(key, strict); |
| } |
| |
| @Override |
| public boolean delete(final double key, final boolean strict) { |
| final int index = ArrayIndex.getArrayIndex(key); |
| return isMapped(index) ? deleteMapped(index, strict) : super.delete(key, strict); |
| } |
| |
| @Override |
| public boolean delete(final Object key, final boolean strict) { |
| final Object primitiveKey = JSType.toPrimitive(key, String.class); |
| final int index = ArrayIndex.getArrayIndex(primitiveKey); |
| return isMapped(index) ? deleteMapped(index, strict) : super.delete(primitiveKey, strict); |
| } |
| |
| /** |
| * ECMA 15.4.5.1 [[DefineOwnProperty]] ( P, Desc, Throw ) as specialized in |
| * ECMA 10.6 for Arguments object. |
| */ |
| @Override |
| public boolean defineOwnProperty(final Object key, final Object propertyDesc, final boolean reject) { |
| final int index = ArrayIndex.getArrayIndex(key); |
| if (index >= 0) { |
| final boolean isMapped = isMapped(index); |
| final Object oldValue = isMapped ? getArray().getObject(index) : null; |
| |
| if (!super.defineOwnProperty(key, propertyDesc, false)) { |
| if (reject) { |
| throw typeError("cant.redefine.property", key.toString(), ScriptRuntime.safeToString(this)); |
| } |
| return false; |
| } |
| |
| if (isMapped) { |
| // When mapped argument is redefined, if new descriptor is accessor property |
| // or data-non-writable property, we have to "unmap" (unlink). |
| final PropertyDescriptor desc = toPropertyDescriptor(Global.instance(), propertyDesc); |
| if (desc.type() == PropertyDescriptor.ACCESSOR) { |
| setDeleted(index, oldValue); |
| } else if (desc.has(PropertyDescriptor.WRITABLE) && !desc.isWritable()) { |
| // delete and set value from new descriptor if it has one, otherwise use old value |
| setDeleted(index, desc.has(PropertyDescriptor.VALUE) ? desc.getValue() : oldValue); |
| } else if (desc.has(PropertyDescriptor.VALUE)) { |
| setArray(getArray().set(index, desc.getValue(), false)); |
| } |
| } |
| |
| return true; |
| } |
| |
| return super.defineOwnProperty(key, propertyDesc, reject); |
| } |
| |
| // Internals below this point |
| |
| // We track deletions using a bit set (delete arguments[index]) |
| private boolean isDeleted(final int index) { |
| return deleted != null && deleted.get(index); |
| } |
| |
| private void setDeleted(final int index, final Object unmappedValue) { |
| if (deleted == null) { |
| deleted = new BitSet(numMapped); |
| } |
| deleted.set(index, true); |
| setUnmappedArg(index, unmappedValue); |
| } |
| |
| private boolean deleteMapped(final int index, final boolean strict) { |
| final Object value = getArray().getObject(index); |
| final boolean success = super.delete(index, strict); |
| if (success) { |
| setDeleted(index, value); |
| } |
| return success; |
| } |
| |
| private Object getUnmappedArg(final int key) { |
| assert key >= 0 && key < numParams; |
| return unmappedArgs == null ? UNDEFINED : unmappedArgs.getObject(key); |
| } |
| |
| private void setUnmappedArg(final int key, final Object value) { |
| assert key >= 0 && key < numParams; |
| if (unmappedArgs == null) { |
| /* |
| * Declared number of parameters may be more or less than the actual passed |
| * runtime arguments count. We need to truncate or extend with undefined values. |
| * |
| * Example: |
| * |
| * // less declared params |
| * (function (x) { print(arguments); })(20, 44); |
| * |
| * // more declared params |
| * (function (x, y) { print(arguments); })(3); |
| */ |
| final Object[] newValues = new Object[numParams]; |
| System.arraycopy(getArray().asObjectArray(), 0, newValues, 0, numMapped); |
| if (numMapped < numParams) { |
| Arrays.fill(newValues, numMapped, numParams, UNDEFINED); |
| } |
| this.unmappedArgs = ArrayData.allocate(newValues); |
| } |
| // Set value of argument |
| unmappedArgs = unmappedArgs.set(key, value, false); |
| } |
| |
| /** |
| * Are arguments[index] and corresponding named parameter linked? |
| * |
| * In non-strict mode, arguments[index] and corresponding named param are "linked" or "mapped" |
| * if the argument is provided by the caller. Modifications are tacked b/w each other - until |
| * (delete arguments[index]) is used. Once deleted, the corresponding arg is no longer 'mapped'. |
| * Please note that delete can happen only through the arguments array - named param can not |
| * be deleted. (delete is one-way). |
| */ |
| private boolean isMapped(final int index) { |
| // in mapped named args and not marked as "deleted" |
| return index >= 0 && index < numMapped && !isDeleted(index); |
| } |
| |
| /** |
| * Factory to create correct Arguments object based on strict mode. |
| * |
| * @param arguments the actual arguments array passed |
| * @param callee the callee function that uses arguments object |
| * @param numParams the number of declared (named) function parameters |
| * @return Arguments Object |
| */ |
| public static ScriptObject allocate(final Object[] arguments, final ScriptFunction callee, final int numParams) { |
| // Strict functions won't always have a callee for arguments, and will pass null instead. |
| final boolean isStrict = callee == null || callee.isStrict(); |
| final Global global = Global.instance(); |
| final ScriptObject proto = global.getObjectPrototype(); |
| if (isStrict) { |
| return new NativeStrictArguments(arguments, numParams, proto, NativeStrictArguments.getInitialMap()); |
| } |
| return new NativeArguments(arguments, callee, numParams, proto, NativeArguments.getInitialMap()); |
| } |
| |
| /** |
| * Length getter |
| * @param self self reference |
| * @return length property value |
| */ |
| public static Object G$length(final Object self) { |
| if (self instanceof NativeArguments) { |
| return ((NativeArguments)self).getArgumentsLength(); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Length setter |
| * @param self self reference |
| * @param value value for length property |
| */ |
| public static void S$length(final Object self, final Object value) { |
| if (self instanceof NativeArguments) { |
| ((NativeArguments)self).setArgumentsLength(value); |
| } |
| } |
| |
| /** |
| * Callee getter |
| * @param self self reference |
| * @return value for callee property |
| */ |
| public static Object G$callee(final Object self) { |
| if (self instanceof NativeArguments) { |
| return ((NativeArguments)self).getCallee(); |
| } |
| return UNDEFINED; |
| } |
| |
| /** |
| * Callee setter |
| * @param self self reference |
| * @param value value for callee property |
| */ |
| public static void S$callee(final Object self, final Object value) { |
| if (self instanceof NativeArguments) { |
| ((NativeArguments)self).setCallee(value); |
| } |
| } |
| |
| @Override |
| public Object getLength() { |
| return length; |
| } |
| |
| private Object getArgumentsLength() { |
| return length; |
| } |
| |
| private void setArgumentsLength(final Object length) { |
| this.length = length; |
| } |
| |
| private Object getCallee() { |
| return callee; |
| } |
| |
| private void setCallee(final Object callee) { |
| this.callee = callee; |
| } |
| |
| private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { |
| return MH.findStatic(MethodHandles.lookup(), NativeArguments.class, name, MH.type(rtype, types)); |
| } |
| } |