blob: 24d8d2bfa188bf3544e03083597e1dd7edd8ea2d [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// -------------------------------------------------------------------
(function(global, utils) {
%CheckIsBootstrapping();
// -------------------------------------------------------------------
// Imports
var ArrayJoin;
var Bool16x8ToString;
var Bool32x4ToString;
var Bool8x16ToString;
var callSiteReceiverSymbol =
utils.ImportNow("call_site_receiver_symbol");
var callSiteFunctionSymbol =
utils.ImportNow("call_site_function_symbol");
var callSitePositionSymbol =
utils.ImportNow("call_site_position_symbol");
var callSiteStrictSymbol =
utils.ImportNow("call_site_strict_symbol");
var callSiteWasmObjectSymbol =
utils.ImportNow("call_site_wasm_obj_symbol");
var callSiteWasmFunctionIndexSymbol =
utils.ImportNow("call_site_wasm_func_index_symbol");
var Float32x4ToString;
var formattedStackTraceSymbol =
utils.ImportNow("formatted_stack_trace_symbol");
var GlobalObject = global.Object;
var Int16x8ToString;
var Int32x4ToString;
var Int8x16ToString;
var InternalArray = utils.InternalArray;
var internalErrorSymbol = utils.ImportNow("internal_error_symbol");
var ObjectHasOwnProperty;
var ObjectToString = utils.ImportNow("object_to_string");
var Script = utils.ImportNow("Script");
var stackTraceSymbol = utils.ImportNow("stack_trace_symbol");
var StringIndexOf;
var SymbolToString;
var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
var Uint16x8ToString;
var Uint32x4ToString;
var Uint8x16ToString;
utils.Import(function(from) {
ArrayJoin = from.ArrayJoin;
Bool16x8ToString = from.Bool16x8ToString;
Bool32x4ToString = from.Bool32x4ToString;
Bool8x16ToString = from.Bool8x16ToString;
Float32x4ToString = from.Float32x4ToString;
Int16x8ToString = from.Int16x8ToString;
Int32x4ToString = from.Int32x4ToString;
Int8x16ToString = from.Int8x16ToString;
ObjectHasOwnProperty = from.ObjectHasOwnProperty;
StringIndexOf = from.StringIndexOf;
SymbolToString = from.SymbolToString;
Uint16x8ToString = from.Uint16x8ToString;
Uint32x4ToString = from.Uint32x4ToString;
Uint8x16ToString = from.Uint8x16ToString;
});
// -------------------------------------------------------------------
var GlobalError;
var GlobalTypeError;
var GlobalRangeError;
var GlobalURIError;
var GlobalSyntaxError;
var GlobalReferenceError;
var GlobalEvalError;
function NoSideEffectsObjectToString() {
if (IS_UNDEFINED(this)) return "[object Undefined]";
if (IS_NULL(this)) return "[object Null]";
var O = TO_OBJECT(this);
var builtinTag = %_ClassOf(O);
var tag = %GetDataProperty(O, toStringTagSymbol);
if (!IS_STRING(tag)) {
tag = builtinTag;
}
return `[object ${tag}]`;
}
function IsErrorObject(obj) {
return HAS_PRIVATE(obj, stackTraceSymbol);
}
function NoSideEffectsErrorToString() {
var name = %GetDataProperty(this, "name");
var message = %GetDataProperty(this, "message");
name = IS_UNDEFINED(name) ? "Error" : NoSideEffectsToString(name);
message = IS_UNDEFINED(message) ? "" : NoSideEffectsToString(message);
if (name == "") return message;
if (message == "") return name;
return `${name}: ${message}`;
}
function NoSideEffectsToString(obj) {
if (IS_STRING(obj)) return obj;
if (IS_NUMBER(obj)) return %_NumberToString(obj);
if (IS_BOOLEAN(obj)) return obj ? 'true' : 'false';
if (IS_UNDEFINED(obj)) return 'undefined';
if (IS_NULL(obj)) return 'null';
if (IS_FUNCTION(obj)) {
var str = %FunctionToString(obj);
if (str.length > 128) {
str = %_SubString(str, 0, 111) + "...<omitted>..." +
%_SubString(str, str.length - 2, str.length);
}
return str;
}
if (IS_SYMBOL(obj)) return %_Call(SymbolToString, obj);
if (IS_SIMD_VALUE(obj)) {
switch (typeof(obj)) {
case 'float32x4': return %_Call(Float32x4ToString, obj);
case 'int32x4': return %_Call(Int32x4ToString, obj);
case 'int16x8': return %_Call(Int16x8ToString, obj);
case 'int8x16': return %_Call(Int8x16ToString, obj);
case 'uint32x4': return %_Call(Uint32x4ToString, obj);
case 'uint16x8': return %_Call(Uint16x8ToString, obj);
case 'uint8x16': return %_Call(Uint8x16ToString, obj);
case 'bool32x4': return %_Call(Bool32x4ToString, obj);
case 'bool16x8': return %_Call(Bool16x8ToString, obj);
case 'bool8x16': return %_Call(Bool8x16ToString, obj);
}
}
if (IS_RECEIVER(obj)) {
// When internally formatting error objects, use a side-effects-free version
// of Error.prototype.toString independent of the actually installed
// toString method.
if (IsErrorObject(obj) ||
%GetDataProperty(obj, "toString") === ErrorToString) {
return %_Call(NoSideEffectsErrorToString, obj);
}
if (%GetDataProperty(obj, "toString") === ObjectToString) {
var constructor = %GetDataProperty(obj, "constructor");
if (IS_FUNCTION(constructor)) {
var constructor_name = %FunctionGetName(constructor);
if (constructor_name != "") return `#<${constructor_name}>`;
}
}
}
return %_Call(NoSideEffectsObjectToString, obj);
}
function MakeGenericError(constructor, type, arg0, arg1, arg2) {
var error = new constructor(FormatMessage(type, arg0, arg1, arg2));
error[internalErrorSymbol] = true;
return error;
}
/**
* Set up the Script function and constructor.
*/
%FunctionSetInstanceClassName(Script, 'Script');
%AddNamedProperty(Script.prototype, 'constructor', Script,
DONT_ENUM | DONT_DELETE | READ_ONLY);
%SetCode(Script, function(x) {
// Script objects can only be created by the VM.
throw MakeError(kUnsupported);
});
// Helper functions; called from the runtime system.
function FormatMessage(type, arg0, arg1, arg2) {
var arg0 = NoSideEffectsToString(arg0);
var arg1 = NoSideEffectsToString(arg1);
var arg2 = NoSideEffectsToString(arg2);
try {
return %FormatMessageString(type, arg0, arg1, arg2);
} catch (e) {
return "<error>";
}
}
function GetLineNumber(message) {
var start_position = %MessageGetStartPosition(message);
if (start_position == -1) return kNoLineNumberInfo;
var script = %MessageGetScript(message);
var location = script.locationFromPosition(start_position, true);
if (location == null) return kNoLineNumberInfo;
return location.line + 1;
}
//Returns the offset of the given position within the containing line.
function GetColumnNumber(message) {
var script = %MessageGetScript(message);
var start_position = %MessageGetStartPosition(message);
var location = script.locationFromPosition(start_position, true);
if (location == null) return -1;
return location.column;
}
// Returns the source code line containing the given source
// position, or the empty string if the position is invalid.
function GetSourceLine(message) {
var script = %MessageGetScript(message);
var start_position = %MessageGetStartPosition(message);
var location = script.locationFromPosition(start_position, true);
if (location == null) return "";
return location.sourceText;
}
/**
* Get information on a specific source position.
* Returns an object with the following following properties:
* script : script object for the source
* line : source line number
* column : source column within the line
* position : position within the source
* sourceText : a string containing the current line
* @param {number} position The source position
* @param {boolean} include_resource_offset Set to true to have the resource
* offset added to the location
* @return If line is negative or not in the source null is returned.
*/
function ScriptLocationFromPosition(position,
include_resource_offset) {
return %ScriptPositionInfo(this, position, !!include_resource_offset);
}
/**
* If sourceURL comment is available returns sourceURL comment contents.
* Otherwise, script name is returned. See
* http://fbug.googlecode.com/svn/branches/firebug1.1/docs/ReleaseNotes_1.1.txt
* and Source Map Revision 3 proposal for details on using //# sourceURL and
* deprecated //@ sourceURL comment to identify scripts that don't have name.
*
* @return {?string} script name if present, value for //# sourceURL comment or
* deprecated //@ sourceURL comment otherwise.
*/
function ScriptNameOrSourceURL() {
if (this.source_url) return this.source_url;
return this.name;
}
utils.SetUpLockedPrototype(Script, [
"source",
"name",
"source_url",
"source_mapping_url",
"line_offset",
"column_offset"
], [
"locationFromPosition", ScriptLocationFromPosition,
"nameOrSourceURL", ScriptNameOrSourceURL,
]
);
function GetStackTraceLine(recv, fun, pos, isGlobal) {
return new CallSite(recv, fun, pos, false).toString();
}
// ----------------------------------------------------------------------------
// Error implementation
function CallSite(receiver, fun, pos, strict_mode) {
// For wasm frames, receiver is the wasm object and fun is the function index
// instead of an actual function.
if (!IS_FUNCTION(fun) && !%IsWasmObject(receiver)) {
throw MakeTypeError(kCallSiteExpectsFunction, typeof receiver, typeof fun);
}
if (IS_UNDEFINED(new.target)) {
return new CallSite(receiver, fun, pos, strict_mode);
}
if (IS_FUNCTION(fun)) {
SET_PRIVATE(this, callSiteReceiverSymbol, receiver);
SET_PRIVATE(this, callSiteFunctionSymbol, fun);
} else {
SET_PRIVATE(this, callSiteWasmObjectSymbol, receiver);
SET_PRIVATE(this, callSiteWasmFunctionIndexSymbol, TO_UINT32(fun));
}
SET_PRIVATE(this, callSitePositionSymbol, TO_INT32(pos));
SET_PRIVATE(this, callSiteStrictSymbol, TO_BOOLEAN(strict_mode));
}
function CheckCallSite(obj, name) {
if (!IS_RECEIVER(obj) || !HAS_PRIVATE(obj, callSitePositionSymbol)) {
throw MakeTypeError(kCallSiteMethod, name);
}
}
function CallSiteGetThis() {
CheckCallSite(this, "getThis");
return GET_PRIVATE(this, callSiteStrictSymbol)
? UNDEFINED : GET_PRIVATE(this, callSiteReceiverSymbol);
}
function CallSiteGetFunction() {
CheckCallSite(this, "getFunction");
return GET_PRIVATE(this, callSiteStrictSymbol)
? UNDEFINED : GET_PRIVATE(this, callSiteFunctionSymbol);
}
function CallSiteGetPosition() {
CheckCallSite(this, "getPosition");
return GET_PRIVATE(this, callSitePositionSymbol);
}
function CallSiteGetTypeName() {
CheckCallSite(this, "getTypeName");
return GetTypeName(GET_PRIVATE(this, callSiteReceiverSymbol), false);
}
function CallSiteIsToplevel() {
CheckCallSite(this, "isTopLevel");
return %CallSiteIsToplevelRT(this);
}
function CallSiteIsEval() {
CheckCallSite(this, "isEval");
return %CallSiteIsEvalRT(this);
}
function CallSiteGetEvalOrigin() {
CheckCallSite(this, "getEvalOrigin");
var script = %FunctionGetScript(GET_PRIVATE(this, callSiteFunctionSymbol));
return FormatEvalOrigin(script);
}
function CallSiteGetScriptNameOrSourceURL() {
CheckCallSite(this, "getScriptNameOrSourceURL");
return %CallSiteGetScriptNameOrSourceUrlRT(this);
}
function CallSiteGetFunctionName() {
// See if the function knows its own name
CheckCallSite(this, "getFunctionName");
return %CallSiteGetFunctionNameRT(this);
}
function CallSiteGetMethodName() {
// See if we can find a unique property on the receiver that holds
// this function.
CheckCallSite(this, "getMethodName");
return %CallSiteGetMethodNameRT(this);
}
function CallSiteGetFileName() {
CheckCallSite(this, "getFileName");
return %CallSiteGetFileNameRT(this);
}
function CallSiteGetLineNumber() {
if (HAS_PRIVATE(this, callSiteWasmObjectSymbol)) {
return GET_PRIVATE(this, callSiteWasmFunctionIndexSymbol);
}
CheckCallSite(this, "getLineNumber");
return %CallSiteGetLineNumberRT(this);
}
function CallSiteGetColumnNumber() {
CheckCallSite(this, "getColumnNumber");
return %CallSiteGetColumnNumberRT(this);
}
function CallSiteIsNative() {
CheckCallSite(this, "isNative");
return %CallSiteIsNativeRT(this);
}
function CallSiteIsConstructor() {
CheckCallSite(this, "isConstructor");
return %CallSiteIsConstructorRT(this);
}
function CallSiteToString() {
if (HAS_PRIVATE(this, callSiteWasmObjectSymbol)) {
var funName = this.getFunctionName();
var funcIndex = GET_PRIVATE(this, callSiteWasmFunctionIndexSymbol);
var pos = this.getPosition();
if (IS_NULL(funName)) funName = "<WASM UNNAMED>";
return funName + " (<WASM>[" + funcIndex + "]+" + pos + ")";
}
var fileName;
var fileLocation = "";
if (this.isNative()) {
fileLocation = "native";
} else {
fileName = this.getScriptNameOrSourceURL();
if (!fileName && this.isEval()) {
fileLocation = this.getEvalOrigin();
fileLocation += ", "; // Expecting source position to follow.
}
if (fileName) {
fileLocation += fileName;
} else {
// Source code does not originate from a file and is not native, but we
// can still get the source position inside the source string, e.g. in
// an eval string.
fileLocation += "<anonymous>";
}
var lineNumber = this.getLineNumber();
if (lineNumber != null) {
fileLocation += ":" + lineNumber;
var columnNumber = this.getColumnNumber();
if (columnNumber) {
fileLocation += ":" + columnNumber;
}
}
}
var line = "";
var functionName = this.getFunctionName();
var addSuffix = true;
var isConstructor = this.isConstructor();
var isMethodCall = !(this.isToplevel() || isConstructor);
if (isMethodCall) {
var typeName = GetTypeName(GET_PRIVATE(this, callSiteReceiverSymbol), true);
var methodName = this.getMethodName();
if (functionName) {
if (typeName && %_Call(StringIndexOf, functionName, typeName) != 0) {
line += typeName + ".";
}
line += functionName;
if (methodName &&
(%_Call(StringIndexOf, functionName, "." + methodName) !=
functionName.length - methodName.length - 1)) {
line += " [as " + methodName + "]";
}
} else {
line += typeName + "." + (methodName || "<anonymous>");
}
} else if (isConstructor) {
line += "new " + (functionName || "<anonymous>");
} else if (functionName) {
line += functionName;
} else {
line += fileLocation;
addSuffix = false;
}
if (addSuffix) {
line += " (" + fileLocation + ")";
}
return line;
}
utils.SetUpLockedPrototype(CallSite, ["receiver", "fun", "pos"], [
"getThis", CallSiteGetThis,
"getTypeName", CallSiteGetTypeName,
"isToplevel", CallSiteIsToplevel,
"isEval", CallSiteIsEval,
"getEvalOrigin", CallSiteGetEvalOrigin,
"getScriptNameOrSourceURL", CallSiteGetScriptNameOrSourceURL,
"getFunction", CallSiteGetFunction,
"getFunctionName", CallSiteGetFunctionName,
"getMethodName", CallSiteGetMethodName,
"getFileName", CallSiteGetFileName,
"getLineNumber", CallSiteGetLineNumber,
"getColumnNumber", CallSiteGetColumnNumber,
"isNative", CallSiteIsNative,
"getPosition", CallSiteGetPosition,
"isConstructor", CallSiteIsConstructor,
"toString", CallSiteToString
]);
function FormatEvalOrigin(script) {
var sourceURL = script.nameOrSourceURL();
if (sourceURL) {
return sourceURL;
}
var eval_origin = "eval at ";
if (script.eval_from_function_name) {
eval_origin += script.eval_from_function_name;
} else {
eval_origin += "<anonymous>";
}
var eval_from_script = script.eval_from_script;
if (eval_from_script) {
if (eval_from_script.compilation_type == COMPILATION_TYPE_EVAL) {
// eval script originated from another eval.
eval_origin += " (" + FormatEvalOrigin(eval_from_script) + ")";
} else {
// eval script originated from "real" source.
if (eval_from_script.name) {
eval_origin += " (" + eval_from_script.name;
var location = eval_from_script.locationFromPosition(
script.eval_from_script_position, true);
if (location) {
eval_origin += ":" + (location.line + 1);
eval_origin += ":" + (location.column + 1);
}
eval_origin += ")";
} else {
eval_origin += " (unknown source)";
}
}
}
return eval_origin;
}
function FormatErrorString(error) {
try {
return %_Call(ErrorToString, error);
} catch (e) {
try {
return "<error: " + e + ">";
} catch (ee) {
return "<error>";
}
}
}
function GetStackFrames(raw_stack) {
var internal_raw_stack = new InternalArray();
%MoveArrayContents(raw_stack, internal_raw_stack);
var frames = new InternalArray();
var sloppy_frames = internal_raw_stack[0];
for (var i = 1; i < internal_raw_stack.length; i += 4) {
var recv = internal_raw_stack[i];
var fun = internal_raw_stack[i + 1];
var code = internal_raw_stack[i + 2];
var pc = internal_raw_stack[i + 3];
// For traps in wasm, the bytecode offset is passed as (-1 - offset).
// Otherwise, lookup the position from the pc.
var pos = IS_NUMBER(fun) && pc < 0 ? (-1 - pc) :
%FunctionGetPositionForOffset(code, pc);
sloppy_frames--;
frames.push(new CallSite(recv, fun, pos, (sloppy_frames < 0)));
}
return frames;
}
// Flag to prevent recursive call of Error.prepareStackTrace.
var formatting_custom_stack_trace = false;
function FormatStackTrace(obj, raw_stack) {
var frames = GetStackFrames(raw_stack);
if (IS_FUNCTION(GlobalError.prepareStackTrace) &&
!formatting_custom_stack_trace) {
var array = [];
%MoveArrayContents(frames, array);
formatting_custom_stack_trace = true;
var stack_trace = UNDEFINED;
try {
stack_trace = GlobalError.prepareStackTrace(obj, array);
} catch (e) {
throw e; // The custom formatting function threw. Rethrow.
} finally {
formatting_custom_stack_trace = false;
}
return stack_trace;
}
var lines = new InternalArray();
lines.push(FormatErrorString(obj));
for (var i = 0; i < frames.length; i++) {
var frame = frames[i];
var line;
try {
line = frame.toString();
} catch (e) {
try {
line = "<error: " + e + ">";
} catch (ee) {
// Any code that reaches this point is seriously nasty!
line = "<error>";
}
}
lines.push(" at " + line);
}
return %_Call(ArrayJoin, lines, "\n");
}
function GetTypeName(receiver, requireConstructor) {
if (IS_NULL_OR_UNDEFINED(receiver)) return null;
if (IS_PROXY(receiver)) return "Proxy";
var constructor = %GetDataProperty(TO_OBJECT(receiver), "constructor");
if (!IS_FUNCTION(constructor)) {
return requireConstructor ? null : %_Call(NoSideEffectsToString, receiver);
}
return %FunctionGetName(constructor);
}
// Format the stack trace if not yet done, and return it.
// Cache the formatted stack trace on the holder.
var StackTraceGetter = function() {
var formatted_stack_trace = UNDEFINED;
var holder = this;
while (holder) {
var formatted_stack_trace =
GET_PRIVATE(holder, formattedStackTraceSymbol);
if (IS_UNDEFINED(formatted_stack_trace)) {
// No formatted stack trace available.
var stack_trace = GET_PRIVATE(holder, stackTraceSymbol);
if (IS_UNDEFINED(stack_trace)) {
// Neither formatted nor structured stack trace available.
// Look further up the prototype chain.
holder = %object_get_prototype_of(holder);
continue;
}
formatted_stack_trace = FormatStackTrace(holder, stack_trace);
SET_PRIVATE(holder, stackTraceSymbol, UNDEFINED);
SET_PRIVATE(holder, formattedStackTraceSymbol, formatted_stack_trace);
}
return formatted_stack_trace;
}
return UNDEFINED;
};
// If the receiver equals the holder, set the formatted stack trace that the
// getter returns.
var StackTraceSetter = function(v) {
if (IsErrorObject(this)) {
SET_PRIVATE(this, stackTraceSymbol, UNDEFINED);
SET_PRIVATE(this, formattedStackTraceSymbol, v);
}
};
// Use a dummy function since we do not actually want to capture a stack trace
// when constructing the initial Error prototytpes.
var captureStackTrace = function() {};
// Set up special error type constructors.
function SetUpError(error_function) {
%FunctionSetInstanceClassName(error_function, 'Error');
var name = error_function.name;
var prototype = new GlobalObject();
if (name !== 'Error') {
%InternalSetPrototype(error_function, GlobalError);
%InternalSetPrototype(prototype, GlobalError.prototype);
}
%FunctionSetPrototype(error_function, prototype);
%AddNamedProperty(error_function.prototype, 'name', name, DONT_ENUM);
%AddNamedProperty(error_function.prototype, 'message', '', DONT_ENUM);
%AddNamedProperty(
error_function.prototype, 'constructor', error_function, DONT_ENUM);
%SetCode(error_function, function(m) {
if (IS_UNDEFINED(new.target)) return new error_function(m);
try { captureStackTrace(this, error_function); } catch (e) { }
// Define all the expected properties directly on the error
// object. This avoids going through getters and setters defined
// on prototype objects.
if (!IS_UNDEFINED(m)) {
%AddNamedProperty(this, 'message', TO_STRING(m), DONT_ENUM);
}
});
%SetNativeFlag(error_function);
return error_function;
};
GlobalError = SetUpError(global.Error);
GlobalEvalError = SetUpError(global.EvalError);
GlobalRangeError = SetUpError(global.RangeError);
GlobalReferenceError = SetUpError(global.ReferenceError);
GlobalSyntaxError = SetUpError(global.SyntaxError);
GlobalTypeError = SetUpError(global.TypeError);
GlobalURIError = SetUpError(global.URIError);
utils.InstallFunctions(GlobalError.prototype, DONT_ENUM,
['toString', ErrorToString]);
function ErrorToString() {
if (!IS_RECEIVER(this)) {
throw MakeTypeError(kCalledOnNonObject, "Error.prototype.toString");
}
var name = this.name;
name = IS_UNDEFINED(name) ? "Error" : TO_STRING(name);
var message = this.message;
message = IS_UNDEFINED(message) ? "" : TO_STRING(message);
if (name == "") return message;
if (message == "") return name;
return `${name}: ${message}`
}
function MakeError(type, arg0, arg1, arg2) {
return MakeGenericError(GlobalError, type, arg0, arg1, arg2);
}
function MakeRangeError(type, arg0, arg1, arg2) {
return MakeGenericError(GlobalRangeError, type, arg0, arg1, arg2);
}
function MakeSyntaxError(type, arg0, arg1, arg2) {
return MakeGenericError(GlobalSyntaxError, type, arg0, arg1, arg2);
}
function MakeTypeError(type, arg0, arg1, arg2) {
return MakeGenericError(GlobalTypeError, type, arg0, arg1, arg2);
}
function MakeURIError() {
return MakeGenericError(GlobalURIError, kURIMalformed);
}
// Boilerplate for exceptions for stack overflows. Used from
// Isolate::StackOverflow().
var StackOverflowBoilerplate = MakeRangeError(kStackOverflow);
utils.InstallGetterSetter(StackOverflowBoilerplate, 'stack',
StackTraceGetter, StackTraceSetter)
// Define actual captureStackTrace function after everything has been set up.
captureStackTrace = function captureStackTrace(obj, cons_opt) {
// Define accessors first, as this may fail and throw.
%object_define_property(obj, 'stack', { get: StackTraceGetter,
set: StackTraceSetter,
configurable: true });
%CollectStackTrace(obj, cons_opt ? cons_opt : captureStackTrace);
};
GlobalError.captureStackTrace = captureStackTrace;
%InstallToContext([
"get_stack_trace_line_fun", GetStackTraceLine,
"make_error_function", MakeGenericError,
"make_range_error", MakeRangeError,
"make_type_error", MakeTypeError,
"message_get_column_number", GetColumnNumber,
"message_get_line_number", GetLineNumber,
"message_get_source_line", GetSourceLine,
"no_side_effects_to_string_fun", NoSideEffectsToString,
"stack_overflow_boilerplate", StackOverflowBoilerplate,
]);
utils.Export(function(to) {
to.ErrorToString = ErrorToString;
to.MakeError = MakeError;
to.MakeRangeError = MakeRangeError;
to.MakeSyntaxError = MakeSyntaxError;
to.MakeTypeError = MakeTypeError;
to.MakeURIError = MakeURIError;
});
});