rhino1.7.7.src.org.mozilla.javascript.Arguments Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rhino Show documentation
Show all versions of rhino Show documentation
Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically
embedded into Java applications to provide scripting to end users.
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
/**
* This class implements the "arguments" object.
*
* See ECMA 10.1.8
*
* @see org.mozilla.javascript.NativeCall
* @author Norris Boyd
*/
final class Arguments extends IdScriptableObject
{
static final long serialVersionUID = 4275508002492040609L;
private static final String FTAG = "Arguments";
public Arguments(NativeCall activation)
{
this.activation = activation;
Scriptable parent = activation.getParentScope();
setParentScope(parent);
setPrototype(ScriptableObject.getObjectPrototype(parent));
args = activation.originalArgs;
lengthObj = Integer.valueOf(args.length);
NativeFunction f = activation.function;
calleeObj = f;
int version = f.getLanguageVersion();
if (version <= Context.VERSION_1_3
&& version != Context.VERSION_DEFAULT)
{
callerObj = null;
} else {
callerObj = NOT_FOUND;
}
}
@Override
public String getClassName()
{
return FTAG;
}
private Object arg(int index) {
if (index < 0 || args.length <= index) return NOT_FOUND;
return args[index];
}
// the following helper methods assume that 0 < index < args.length
private void putIntoActivation(int index, Object value) {
String argName = activation.function.getParamOrVarName(index);
activation.put(argName, activation, value);
}
private Object getFromActivation(int index) {
String argName = activation.function.getParamOrVarName(index);
return activation.get(argName, activation);
}
private void replaceArg(int index, Object value) {
if (sharedWithActivation(index)) {
putIntoActivation(index, value);
}
synchronized (this) {
if (args == activation.originalArgs) {
args = args.clone();
}
args[index] = value;
}
}
private void removeArg(int index) {
synchronized (this) {
if (args[index] != NOT_FOUND) {
if (args == activation.originalArgs) {
args = args.clone();
}
args[index] = NOT_FOUND;
}
}
}
// end helpers
@Override
public boolean has(int index, Scriptable start)
{
if (arg(index) != NOT_FOUND) {
return true;
}
return super.has(index, start);
}
@Override
public Object get(int index, Scriptable start)
{
final Object value = arg(index);
if (value == NOT_FOUND) {
return super.get(index, start);
} else {
if (sharedWithActivation(index)) {
return getFromActivation(index);
} else {
return value;
}
}
}
private boolean sharedWithActivation(int index)
{
NativeFunction f = activation.function;
int definedCount = f.getParamCount();
if (index < definedCount) {
// Check if argument is not hidden by later argument with the same
// name as hidden arguments are not shared with activation
if (index < definedCount - 1) {
String argName = f.getParamOrVarName(index);
for (int i = index + 1; i < definedCount; i++) {
if (argName.equals(f.getParamOrVarName(i))) {
return false;
}
}
}
return true;
}
return false;
}
@Override
public void put(int index, Scriptable start, Object value)
{
if (arg(index) == NOT_FOUND) {
super.put(index, start, value);
} else {
replaceArg(index, value);
}
}
@Override
public void delete(int index)
{
if (0 <= index && index < args.length) {
removeArg(index);
}
super.delete(index);
}
// #string_id_map#
private static final int
Id_callee = 1,
Id_length = 2,
Id_caller = 3,
MAX_INSTANCE_ID = Id_caller;
@Override
protected int getMaxInstanceId()
{
return MAX_INSTANCE_ID;
}
@Override
protected int findInstanceIdInfo(String s)
{
int id;
// #generated# Last update: 2010-01-06 05:48:21 ARST
L0: { id = 0; String X = null; int c;
int s_length = s.length();
if (s_length==6) {
c=s.charAt(5);
if (c=='e') { X="callee";id=Id_callee; }
else if (c=='h') { X="length";id=Id_length; }
else if (c=='r') { X="caller";id=Id_caller; }
}
if (X!=null && X!=s && !X.equals(s)) id = 0;
break L0;
}
// #/generated#
if (id == 0) return super.findInstanceIdInfo(s);
int attr;
switch (id) {
case Id_callee:
attr = calleeAttr;
break;
case Id_caller:
attr = callerAttr;
break;
case Id_length:
attr = lengthAttr;
break;
default: throw new IllegalStateException();
}
return instanceIdInfo(attr, id);
}
// #/string_id_map#
@Override
protected String getInstanceIdName(int id)
{
switch (id) {
case Id_callee: return "callee";
case Id_length: return "length";
case Id_caller: return "caller";
}
return null;
}
@Override
protected Object getInstanceIdValue(int id)
{
switch (id) {
case Id_callee: return calleeObj;
case Id_length: return lengthObj;
case Id_caller: {
Object value = callerObj;
if (value == UniqueTag.NULL_VALUE) { value = null; }
else if (value == null) {
NativeCall caller = activation.parentActivationCall;
if (caller != null) {
value = caller.get("arguments", caller);
}
}
return value;
}
}
return super.getInstanceIdValue(id);
}
@Override
protected void setInstanceIdValue(int id, Object value)
{
switch (id) {
case Id_callee: calleeObj = value; return;
case Id_length: lengthObj = value; return;
case Id_caller:
callerObj = (value != null) ? value : UniqueTag.NULL_VALUE;
return;
}
super.setInstanceIdValue(id, value);
}
@Override
protected void setInstanceIdAttributes(int id, int attr)
{
switch (id) {
case Id_callee: calleeAttr = attr; return;
case Id_length: lengthAttr = attr; return;
case Id_caller: callerAttr = attr; return;
}
super.setInstanceIdAttributes(id, attr);
}
@Override
Object[] getIds(boolean getAll)
{
Object[] ids = super.getIds(getAll);
if (args.length != 0) {
boolean[] present = new boolean[args.length];
int extraCount = args.length;
for (int i = 0; i != ids.length; ++i) {
Object id = ids[i];
if (id instanceof Integer) {
int index = ((Integer)id).intValue();
if (0 <= index && index < args.length) {
if (!present[index]) {
present[index] = true;
extraCount--;
}
}
}
}
if (!getAll) { // avoid adding args which were redefined to non-enumerable
for (int i = 0; i < present.length; i++) {
if (!present[i] && super.has(i, this)) {
present[i] = true;
extraCount--;
}
}
}
if (extraCount != 0) {
Object[] tmp = new Object[extraCount + ids.length];
System.arraycopy(ids, 0, tmp, extraCount, ids.length);
ids = tmp;
int offset = 0;
for (int i = 0; i != args.length; ++i) {
if (present == null || !present[i]) {
ids[offset] = Integer.valueOf(i);
++offset;
}
}
if (offset != extraCount) Kit.codeBug();
}
}
return ids;
}
@Override
protected ScriptableObject getOwnPropertyDescriptor(Context cx, Object id) {
double d = ScriptRuntime.toNumber(id);
int index = (int) d;
if (d != index) {
return super.getOwnPropertyDescriptor(cx, id);
}
Object value = arg(index);
if (value == NOT_FOUND) {
return super.getOwnPropertyDescriptor(cx, id);
}
if (sharedWithActivation(index)) {
value = getFromActivation(index);
}
if (super.has(index, this)) { // the descriptor has been redefined
ScriptableObject desc = super.getOwnPropertyDescriptor(cx, id);
desc.put("value", desc, value);
return desc;
} else {
Scriptable scope = getParentScope();
if (scope == null) scope = this;
return buildDataDescriptor(scope, value, EMPTY);
}
}
@Override
protected void defineOwnProperty(Context cx, Object id,
ScriptableObject desc,
boolean checkValid) {
super.defineOwnProperty(cx, id, desc, checkValid);
double d = ScriptRuntime.toNumber(id);
int index = (int) d;
if (d != index) return;
Object value = arg(index);
if (value == NOT_FOUND) return;
if (isAccessorDescriptor(desc)) {
removeArg(index);
return;
}
Object newValue = getProperty(desc, "value");
if (newValue == NOT_FOUND) return;
replaceArg(index, newValue);
if (isFalse(getProperty(desc, "writable"))) {
removeArg(index);
}
}
// Fields to hold caller, callee and length properties,
// where NOT_FOUND value tags deleted properties.
// In addition if callerObj == NULL_VALUE, it tags null for scripts, as
// initial callerObj == null means access to caller arguments available
// only in JS <= 1.3 scripts
private Object callerObj;
private Object calleeObj;
private Object lengthObj;
private int callerAttr = DONTENUM;
private int calleeAttr = DONTENUM;
private int lengthAttr = DONTENUM;
private NativeCall activation;
// Initially args holds activation.getOriginalArgs(), but any modification
// of its elements triggers creation of a copy. If its element holds NOT_FOUND,
// it indicates deleted index, in which case super class is queried.
private Object[] args;
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy