org.mozilla.javascript.NativeError Maven / Gradle / Ivy
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/* -*- 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;
import java.io.Serializable;
/**
* The class of error objects
*
* ECMA 15.11
*/
final class NativeError extends IdScriptableObject {
private static final long serialVersionUID = -5338413581437645187L;
private static final Object ERROR_TAG = "Error";
private static final String STACK_TAG = "stack";
/** Default stack limit is set to "Infinity", here represented as a negative int */
public static final int DEFAULT_STACK_LIMIT = -1;
// This is used by "captureStackTrace"
private static final String STACK_HIDE_KEY = "_stackHide";
private RhinoException stackProvider;
private Object stack;
static void init(Scriptable scope, boolean sealed) {
NativeError obj = new NativeError();
ScriptableObject.putProperty(obj, "name", "Error");
ScriptableObject.putProperty(obj, "message", "");
ScriptableObject.putProperty(obj, "fileName", "");
ScriptableObject.putProperty(obj, "lineNumber", 0);
obj.setAttributes("name", ScriptableObject.DONTENUM);
obj.setAttributes("message", ScriptableObject.DONTENUM);
obj.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
NativeCallSite.init(obj, sealed);
}
static NativeError make(Context cx, Scriptable scope, IdFunctionObject ctorObj, Object[] args) {
Scriptable proto = (Scriptable) (ctorObj.get("prototype", ctorObj));
NativeError obj = new NativeError();
obj.setPrototype(proto);
obj.setParentScope(scope);
int arglen = args.length;
if (arglen >= 1) {
if (!Undefined.isUndefined(args[0])) {
ScriptableObject.putProperty(obj, "message", ScriptRuntime.toString(args[0]));
obj.setAttributes("message", ScriptableObject.DONTENUM);
}
if (arglen >= 2) {
ScriptableObject.putProperty(obj, "fileName", args[1]);
if (arglen >= 3) {
int line = ScriptRuntime.toInt32(args[2]);
ScriptableObject.putProperty(obj, "lineNumber", line);
}
}
}
return obj;
}
@Override
protected void fillConstructorProperties(IdFunctionObject ctor) {
addIdFunctionProperty(
ctor, ERROR_TAG, ConstructorId_captureStackTrace, "captureStackTrace", 2);
// Define a stack to be used even if this Error is never thrown.
// The big cost is in turning this into an actual stack trace, which is set up to
// be done lazily below.
stackProvider = new EvaluatorException("");
// This is running on the global "Error" object. Associate an object there that can store
// default stack trace, etc.
// This prevents us from having to add two additional fields to every Error object.
ProtoProps protoProps = new ProtoProps();
associateValue(ProtoProps.KEY, protoProps);
ctor.defineProperty(
"stackTraceLimit",
protoProps::getStackTraceLimit,
protoProps::setStackTraceLimit,
0);
ctor.defineProperty(
"prepareStackTrace",
protoProps::getPrepareStackTrace,
protoProps::setPrepareStackTrace,
0);
super.fillConstructorProperties(ctor);
}
@Override
public String getClassName() {
return "Error";
}
@Override
public String toString() {
// According to spec, Error.prototype.toString() may return undefined.
Object toString = js_toString(this);
return toString instanceof String ? (String) toString : super.toString();
}
@Override
protected void initPrototypeId(int id) {
String s;
int arity;
switch (id) {
case Id_constructor:
arity = 1;
s = "constructor";
break;
case Id_toString:
arity = 0;
s = "toString";
break;
case Id_toSource:
arity = 0;
s = "toSource";
break;
default:
throw new IllegalArgumentException(String.valueOf(id));
}
initPrototypeMethod(ERROR_TAG, id, s, arity);
}
@Override
public Object execIdCall(
IdFunctionObject f, Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
if (!f.hasTag(ERROR_TAG)) {
return super.execIdCall(f, cx, scope, thisObj, args);
}
int id = f.methodId();
switch (id) {
case Id_constructor:
NativeError err = make(cx, scope, f, args);
// All new Errors have a default exception installed so that
// there is a stack trace captured even if they are never thrown.
err.setStackProvider(new EvaluatorException(""));
return err;
case Id_toString:
return js_toString(thisObj);
case Id_toSource:
return js_toSource(cx, scope, thisObj);
case ConstructorId_captureStackTrace:
js_captureStackTrace(cx, scope, thisObj, args);
return Undefined.instance;
}
throw new IllegalArgumentException(String.valueOf(id));
}
public void setStackProvider(RhinoException re) {
// We go some extra miles to make sure the stack property is only
// generated on demand, is cached after the first access, and is
// overwritable like an ordinary property. Hence this setup with
// the getter and setter below.
if (stackProvider == null) {
defineProperty(STACK_TAG, this::getStackDelegated, this::setStackDelegated, DONTENUM);
}
stackProvider = re;
}
public Object getStackDelegated() {
if (stack != null) {
return stack;
}
if (stackProvider == null) {
return NOT_FOUND;
}
// Get the object where prototype stuff is stored.
int limit = DEFAULT_STACK_LIMIT;
Function prepare = null;
NativeError cons = (NativeError) getPrototype();
ProtoProps pp = (ProtoProps) cons.getAssociatedValue(ProtoProps.KEY);
if (pp != null) {
limit = pp.stackTraceLimit;
prepare = pp.prepareStackTrace;
}
// This key is only set by captureStackTrace
String hideFunc = (String) getAssociatedValue(STACK_HIDE_KEY);
ScriptStackElement[] stackTrace = stackProvider.getScriptStack(limit, hideFunc);
// Determine whether to format the stack trace ourselves, or call the user's code to do it
Object value;
if (prepare == null) {
value = RhinoException.formatStackTrace(stackTrace, stackProvider.details());
} else {
value = callPrepareStack(prepare, stackTrace);
}
stack = value;
return value;
}
public void setStackDelegated(Object value) {
stackProvider = null;
stack = value;
}
private Object callPrepareStack(Function prepare, ScriptStackElement[] stack) {
Context cx = Context.getCurrentContext();
Object[] elts = new Object[stack.length];
// The "prepareStackTrace" function takes an array of CallSite objects.
for (int i = 0; i < stack.length; i++) {
NativeCallSite site = (NativeCallSite) cx.newObject(this, "CallSite");
site.setElement(stack[i]);
elts[i] = site;
}
Scriptable eltArray = cx.newArray(this, elts);
return prepare.call(cx, prepare, this, new Object[] {this, eltArray});
}
private static Object js_toString(Scriptable thisObj) {
Object nameObj = ScriptableObject.getProperty(thisObj, "name");
String name;
if (nameObj == NOT_FOUND || Undefined.isUndefined(nameObj)) {
name = "Error";
} else {
name = ScriptRuntime.toString(nameObj);
}
Object msgObj = ScriptableObject.getProperty(thisObj, "message");
String msg;
if (msgObj == NOT_FOUND || Undefined.isUndefined(msgObj)) {
msg = "";
} else {
msg = ScriptRuntime.toString(msgObj);
}
if (name.isEmpty()) {
return msg;
} else if (msg.isEmpty()) {
return name;
} else {
return name + ": " + msg;
}
}
private static String js_toSource(Context cx, Scriptable scope, Scriptable thisObj) {
// Emulation of SpiderMonkey behavior
Object name = ScriptableObject.getProperty(thisObj, "name");
Object message = ScriptableObject.getProperty(thisObj, "message");
Object fileName = ScriptableObject.getProperty(thisObj, "fileName");
Object lineNumber = ScriptableObject.getProperty(thisObj, "lineNumber");
StringBuilder sb = new StringBuilder();
sb.append("(new ");
if (name == NOT_FOUND) {
name = Undefined.instance;
}
sb.append(ScriptRuntime.toString(name));
sb.append("(");
if (message != NOT_FOUND || fileName != NOT_FOUND || lineNumber != NOT_FOUND) {
if (message == NOT_FOUND) {
message = "";
}
sb.append(ScriptRuntime.uneval(cx, scope, message));
if (fileName != NOT_FOUND || lineNumber != NOT_FOUND) {
sb.append(", ");
if (fileName == NOT_FOUND) {
fileName = "";
}
sb.append(ScriptRuntime.uneval(cx, scope, fileName));
if (lineNumber != NOT_FOUND) {
int line = ScriptRuntime.toInt32(lineNumber);
if (line != 0) {
sb.append(", ");
sb.append(ScriptRuntime.toString(line));
}
}
}
}
sb.append("))");
return sb.toString();
}
private static void js_captureStackTrace(
Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
ScriptableObject obj = (ScriptableObject) ScriptRuntime.toObject(cx, scope, args[0]);
Function func = null;
if (args.length > 1) {
func = (Function) ScriptRuntime.toObjectOrNull(cx, args[1], scope);
}
// Create a new error that will have the correct prototype so we can re-use "getStackTrace"
NativeError err = (NativeError) cx.newObject(thisObj, "Error");
// Wire it up so that it will have an actual exception with a stack trace
err.setStackProvider(new EvaluatorException("[object Object]"));
// Figure out if they passed a function used to hide part of the stack
if (func != null) {
Object funcName = func.get("name", func);
if ((funcName != null) && !Undefined.isUndefined(funcName)) {
err.associateValue(STACK_HIDE_KEY, Context.toString(funcName));
}
}
// from https://v8.dev/docs/stack-trace-api
// Error.captureStackTrace(error, constructorOpt)
// adds a stack property to the given error object that yields the stack trace
// at the time captureStackTrace was called. Stack traces collected through
// Error.captureStackTrace are immediately collected, formatted,
// and attached to the given error object.
obj.defineProperty(STACK_TAG, err.get(STACK_TAG), ScriptableObject.DONTENUM);
}
@Override
protected int findPrototypeId(String s) {
int id;
switch (s) {
case "constructor":
id = Id_constructor;
break;
case "toString":
id = Id_toString;
break;
case "toSource":
id = Id_toSource;
break;
default:
id = 0;
break;
}
return id;
}
private static final int Id_constructor = 1,
Id_toString = 2,
Id_toSource = 3,
ConstructorId_captureStackTrace = -1,
MAX_PROTOTYPE_ID = 3;
/**
* We will attch this object to the constructor and use it solely to store the constructor
* properties that are "global." We can't make them static because there can be many contexts in
* the same JVM.
*/
private static final class ProtoProps implements Serializable {
static final String KEY = "_ErrorPrototypeProps";
private static final long serialVersionUID = 1907180507775337939L;
int stackTraceLimit = DEFAULT_STACK_LIMIT;
Function prepareStackTrace;
public Object getStackTraceLimit() {
if (stackTraceLimit >= 0) {
return stackTraceLimit;
}
return Double.POSITIVE_INFINITY;
}
public void setStackTraceLimit(Object value) {
double limit = Context.toNumber(value);
if (Double.isNaN(limit) || Double.isInfinite(limit)) {
stackTraceLimit = -1;
} else {
stackTraceLimit = (int) limit;
}
}
public Object getPrepareStackTrace() {
return (prepareStackTrace == null ? Undefined.instance : prepareStackTrace);
}
public void setPrepareStackTrace(Object value) {
if ((value == null) || Undefined.isUndefined(value)) {
prepareStackTrace = null;
} else if (value instanceof Function) {
prepareStackTrace = (Function) value;
}
}
}
}