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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* 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
/*
* JS standard exception implementation.
*/
#include "jsexn.h"
#include "mozilla/Assertions.h"
#include "mozilla/Maybe.h"
#include "mozilla/ScopeExit.h"
#include <new>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <utility>
#include "jsapi.h"
#include "jsfriendapi.h"
#include "jstypes.h"
#include "frontend/FrontendContext.h" // AutoReportFrontendContext
#include "js/CharacterEncoding.h" // JS::UTF8Chars, JS::ConstUTF8CharsZ
#include "js/Class.h"
#include "js/ColumnNumber.h" // JS::ColumnNumberOneOrigin, JS::TaggedColumnNumberOneOrigin
#include "js/Conversions.h"
#include "js/ErrorReport.h" // JS::PrintError
#include "js/Exception.h" // JS::ExceptionStack
#include "js/experimental/TypedData.h" // JS_IsArrayBufferViewObject
#include "js/friend/ErrorMessages.h" // JSErrNum, js::GetErrorMessage, JSMSG_*
#include "js/Object.h" // JS::GetBuiltinClass
#include "js/PropertyAndElement.h" // JS_GetProperty, JS_HasProperty
#include "js/SavedFrameAPI.h"
#include "js/Stack.h"
#include "js/UniquePtr.h"
#include "js/Value.h"
#include "js/Warnings.h" // JS::{,Set}WarningReporter
#include "js/Wrapper.h"
#include "util/Memory.h"
#include "util/StringBuilder.h"
#include "vm/Compartment.h"
#include "vm/ErrorObject.h"
#include "vm/FrameIter.h" // js::NonBuiltinFrameIter
#include "vm/JSAtomUtils.h" // ClassName
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/JSScript.h"
#include "vm/Realm.h"
#include "vm/SavedFrame.h"
#include "vm/SavedStacks.h"
#include "vm/SelfHosting.h"
#include "vm/Stack.h"
#include "vm/StringType.h"
#include "vm/SymbolType.h"
#include "wasm/WasmJS.h" // WasmExceptionObject
#include "vm/Compartment-inl.h"
#include "vm/ErrorObject-inl.h"
#include "vm/JSContext-inl.h"
#include "vm/JSObject-inl.h"
#include "vm/ObjectOperations-inl.h" // js::GetProperty
#include "vm/SavedStacks-inl.h"
using namespace js;
using JS::SavedFrameSelfHosted;
size_t ExtraMallocSize(JSErrorReport* report) {
if (report->linebuf()) {
/*
* Count with null terminator and alignment.
* See CopyExtraData for the details about alignment.
*/
return (report->linebufLength() + 1) * sizeof(char16_t) + 1;
}
return 0;
}
size_t ExtraMallocSize(JSErrorNotes::Note* note) { return 0; }
bool CopyExtraData(JSContext* cx, uint8_t** cursor, JSErrorReport* copy,
JSErrorReport* report) {
if (report->linebuf()) {
/*
* Make sure cursor is properly aligned for char16_t for platforms
* which need it and it's at the end of the buffer on exit.
*/
size_t alignment_backlog = 0;
if (size_t(*cursor) % 2) {
(*cursor)++;
} else {
alignment_backlog = 1;
}
size_t linebufSize = (report->linebufLength() + 1) * sizeof(char16_t);
const char16_t* linebufCopy = (const char16_t*)(*cursor);
js_memcpy(*cursor, report->linebuf(), linebufSize);
*cursor += linebufSize + alignment_backlog;
copy->initBorrowedLinebuf(linebufCopy, report->linebufLength(),
report->tokenOffset());
}
/* Copy non-pointer members. */
copy->isMuted = report->isMuted;
copy->exnType = report->exnType;
copy->isWarning_ = report->isWarning_;
/* Deep copy notes. */
if (report->notes) {
auto copiedNotes = report->notes->copy(cx);
if (!copiedNotes) {
return false;
}
copy->notes = std::move(copiedNotes);
} else {
copy->notes.reset(nullptr);
}
return true;
}
bool CopyExtraData(JSContext* cx, uint8_t** cursor, JSErrorNotes::Note* copy,
JSErrorNotes::Note* report) {
return true;
}
template <typename T>
static UniquePtr<T> CopyErrorHelper(JSContext* cx, T* report) {
/*
* We use a single malloc block to make a deep copy of JSErrorReport or
* JSErrorNotes::Note, except JSErrorNotes linked from JSErrorReport with
* the following layout:
* JSErrorReport or JSErrorNotes::Note
* char array with characters for message_
* char array with characters for filename
* char16_t array with characters for linebuf (only for JSErrorReport)
* Such layout together with the properties enforced by the following
* asserts does not need any extra alignment padding.
*/
static_assert(sizeof(T) % sizeof(const char*) == 0);
static_assert(sizeof(const char*) % sizeof(char16_t) == 0);
size_t filenameSize =
report->filename ? strlen(report->filename.c_str()) + 1 : 0;
size_t messageSize = 0;
if (report->message()) {
messageSize = strlen(report->message().c_str()) + 1;
}
/*
* The mallocSize can not overflow since it represents the sum of the
* sizes of already allocated objects.
*/
size_t mallocSize =
sizeof(T) + messageSize + filenameSize + ExtraMallocSize(report);
uint8_t* cursor = cx->pod_calloc<uint8_t>(mallocSize);
if (!cursor) {
return nullptr;
}
UniquePtr<T> copy(new (cursor) T());
cursor += sizeof(T);
if (report->message()) {
copy->initBorrowedMessage((const char*)cursor);
js_memcpy(cursor, report->message().c_str(), messageSize);
cursor += messageSize;
}
if (report->filename) {
copy->filename = JS::ConstUTF8CharsZ((const char*)cursor);
js_memcpy(cursor, report->filename.c_str(), filenameSize);
cursor += filenameSize;
}
if (!CopyExtraData(cx, &cursor, copy.get(), report)) {
return nullptr;
}
MOZ_ASSERT(cursor == (uint8_t*)copy.get() + mallocSize);
// errorMessageName should be static.
copy->errorMessageName = report->errorMessageName;
/* Copy non-pointer members. */
copy->sourceId = report->sourceId;
copy->lineno = report->lineno;
copy->column = report->column;
copy->errorNumber = report->errorNumber;
return copy;
}
UniquePtr<JSErrorNotes::Note> js::CopyErrorNote(JSContext* cx,
JSErrorNotes::Note* note) {
return CopyErrorHelper(cx, note);
}
UniquePtr<JSErrorReport> js::CopyErrorReport(JSContext* cx,
JSErrorReport* report) {
return CopyErrorHelper(cx, report);
}
struct SuppressErrorsGuard {
JSContext* cx;
JS::WarningReporter prevReporter;
JS::AutoSaveExceptionState prevState;
explicit SuppressErrorsGuard(JSContext* cx)
: cx(cx),
prevReporter(JS::SetWarningReporter(cx, nullptr)),
prevState(cx) {}
~SuppressErrorsGuard() { JS::SetWarningReporter(cx, prevReporter); }
};
// Cut off the stack if it gets too deep (most commonly for infinite recursion
// errors).
static const size_t MAX_REPORTED_STACK_DEPTH = 1u << 7;
bool js::CaptureStack(JSContext* cx, MutableHandleObject stack) {
return CaptureCurrentStack(
cx, stack, JS::StackCapture(JS::MaxFrames(MAX_REPORTED_STACK_DEPTH)));
}
JSString* js::ComputeStackString(JSContext* cx) {
SuppressErrorsGuard seg(cx);
RootedObject stack(cx);
if (!CaptureStack(cx, &stack)) {
return nullptr;
}
RootedString str(cx);
if (!BuildStackString(cx, cx->realm()->principals(), stack, &str)) {
return nullptr;
}
return str.get();
}
JSErrorReport* js::ErrorFromException(JSContext* cx, HandleObject objArg) {
// It's ok to UncheckedUnwrap here, since all we do is get the
// JSErrorReport, and consumers are careful with the information they get
// from that anyway. Anyone doing things that would expose anything in the
// JSErrorReport to page script either does a security check on the
// JSErrorReport's principal or also tries to do toString on our object and
// will fail if they can't unwrap it.
RootedObject obj(cx, UncheckedUnwrap(objArg));
if (!obj->is<ErrorObject>()) {
return nullptr;
}
JSErrorReport* report = obj->as<ErrorObject>().getOrCreateErrorReport(cx);
if (!report) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
cx->recoverFromOutOfMemory();
}
return report;
}
JS_PUBLIC_API JSObject* JS::ExceptionStackOrNull(HandleObject objArg) {
ErrorObject* errorObject = objArg->maybeUnwrapIf<ErrorObject>();
if (errorObject) {
return errorObject->stack();
}
WasmExceptionObject* wasmObject =
objArg->maybeUnwrapIf<WasmExceptionObject>();
if (wasmObject) {
return wasmObject->stack();
}
return nullptr;
}
JS_PUBLIC_API JSLinearString* js::GetErrorTypeName(JSContext* cx,
int16_t exnType) {
/*
* JSEXN_INTERNALERR returns null to prevent that "InternalError: "
* is prepended before "uncaught exception: "
*/
if (exnType < 0 || exnType >= JSEXN_LIMIT || exnType == JSEXN_INTERNALERR ||
exnType == JSEXN_WARN || exnType == JSEXN_NOTE) {
return nullptr;
}
JSProtoKey key = GetExceptionProtoKey(JSExnType(exnType));
return ClassName(key, cx);
}
bool js::ErrorToException(JSContext* cx, JSErrorReport* reportp,
JSErrorCallback callback, void* userRef) {
MOZ_ASSERT(!reportp->isWarning());
// Find the exception index associated with this error.
JSErrNum errorNumber = static_cast<JSErrNum>(reportp->errorNumber);
if (!callback) {
callback = GetErrorMessage;
}
const JSErrorFormatString* errorString = callback(userRef, errorNumber);
JSExnType exnType =
errorString ? static_cast<JSExnType>(errorString->exnType) : JSEXN_ERR;
MOZ_ASSERT(exnType < JSEXN_ERROR_LIMIT);
// Prevent infinite recursion.
if (cx->generatingError) {
return false;
}
cx->generatingError = true;
auto restore = mozilla::MakeScopeExit([cx] { cx->generatingError = false; });
// Create an exception object.
RootedString messageStr(cx, reportp->newMessageString(cx));
if (!messageStr) {
return false;
}
Rooted<JSString*> fileName(cx);
if (const char* filename = reportp->filename.c_str()) {
fileName =
JS_NewStringCopyUTF8N(cx, JS::UTF8Chars(filename, strlen(filename)));
if (!fileName) {
return false;
}
} else {
fileName = cx->emptyString();
}
uint32_t sourceId = reportp->sourceId;
uint32_t lineNumber = reportp->lineno;
JS::ColumnNumberOneOrigin columnNumber = reportp->column;
// Error reports don't provide a |cause|, so we default to |Nothing| here.
auto cause = JS::NothingHandleValue;
RootedObject stack(cx);
if (!CaptureStack(cx, &stack)) {
return false;
}
UniquePtr<JSErrorReport> report = CopyErrorReport(cx, reportp);
if (!report) {
return false;
}
ErrorObject* errObject =
ErrorObject::create(cx, exnType, stack, fileName, sourceId, lineNumber,
columnNumber, std::move(report), messageStr, cause);
if (!errObject) {
return false;
}
// Throw it.
RootedValue errValue(cx, ObjectValue(*errObject));
Rooted<SavedFrame*> nstack(cx);
if (stack) {
nstack = &stack->as<SavedFrame>();
}
cx->setPendingException(errValue, nstack);
return true;
}
using SniffingBehavior = JS::ErrorReportBuilder::SniffingBehavior;
static bool IsDuckTypedErrorObject(JSContext* cx, HandleObject exnObject,
const char** filename_strp) {
/*
* This function is called from ErrorReport::init and so should not generate
* any new exceptions.
*/
AutoClearPendingException acpe(cx);
bool found;
if (!JS_HasProperty(cx, exnObject, "message", &found) || !found) {
return false;
}
// First try "filename".
const char* filename_str = *filename_strp;
if (!JS_HasProperty(cx, exnObject, filename_str, &found)) {
return false;
}
if (!found) {
// If that doesn't work, try "fileName".
filename_str = "fileName";
if (!JS_HasProperty(cx, exnObject, filename_str, &found) || !found) {
return false;
}
}
if (!JS_HasProperty(cx, exnObject, "lineNumber", &found) || !found) {
return false;
}
*filename_strp = filename_str;
return true;
}
static bool GetPropertyNoException(JSContext* cx, HandleObject obj,
SniffingBehavior behavior,
Handle<PropertyName*> name,
MutableHandleValue vp) {
// This function has no side-effects so always use it.
if (GetPropertyPure(cx, obj, NameToId(name), vp.address())) {
return true;
}
if (behavior == SniffingBehavior::WithSideEffects) {
AutoClearPendingException acpe(cx);
return GetProperty(cx, obj, obj, name, vp);
}
return false;
}
// Create a new error message similar to what Error.prototype.toString would
// produce when called on an object with those property values for name and
// message.
static JSString* FormatErrorMessage(JSContext* cx, HandleString name,
HandleString message) {
if (name && message) {
AutoClearPendingException acpe(cx);
JSStringBuilder sb(cx);
// Prefix the message with the error type, if it exists.
if (!sb.append(name) || !sb.append(": ") || !sb.append(message)) {
return nullptr;
}
return sb.finishString();
}
return name ? name : message;
}
static JSString* ErrorReportToString(JSContext* cx, HandleObject exn,
JSErrorReport* reportp,
SniffingBehavior behavior) {
// The error object might have custom `name` overwriting the exnType in the
// error report. Try getting that property and use the exnType as a fallback.
RootedString name(cx);
RootedValue nameV(cx);
if (GetPropertyNoException(cx, exn, behavior, cx->names().name, &nameV) &&
nameV.isString()) {
name = nameV.toString();
}
// We do NOT want to use GetErrorTypeName() here because it will not do the
// "right thing" for JSEXN_INTERNALERR. That is, the caller of this API
// expects that "InternalError: " will be prepended but GetErrorTypeName
// goes out of its way to avoid this.
if (!name) {
JSExnType type = static_cast<JSExnType>(reportp->exnType);
if (type != JSEXN_WARN && type != JSEXN_NOTE) {
name = ClassName(GetExceptionProtoKey(type), cx);
}
}
RootedString message(cx);
RootedValue messageV(cx);
if (GetPropertyNoException(cx, exn, behavior, cx->names().message,
&messageV) &&
messageV.isString()) {
message = messageV.toString();
}
if (!message) {
message = reportp->newMessageString(cx);
if (!message) {
return nullptr;
}
}
return FormatErrorMessage(cx, name, message);
}
JS::ErrorReportBuilder::ErrorReportBuilder(JSContext* cx)
: reportp(nullptr), exnObject(cx) {}
JS::ErrorReportBuilder::~ErrorReportBuilder() = default;
bool JS::ErrorReportBuilder::init(JSContext* cx,
const JS::ExceptionStack& exnStack,
SniffingBehavior sniffingBehavior) {
MOZ_ASSERT(!cx->isExceptionPending());
MOZ_ASSERT(!reportp);
if (exnStack.exception().isObject()) {
// Because ToString below could error and an exception object could become
// unrooted, we must root our exception object, if any.
exnObject = &exnStack.exception().toObject();
reportp = ErrorFromException(cx, exnObject);
}
// Be careful not to invoke ToString if we've already successfully extracted
// an error report, since the exception might be wrapped in a security
// wrapper, and ToString-ing it might throw.
RootedString str(cx);
if (reportp) {
str = ErrorReportToString(cx, exnObject, reportp, sniffingBehavior);
} else if (exnStack.exception().isSymbol()) {
RootedValue strVal(cx);
if (js::SymbolDescriptiveString(cx, exnStack.exception().toSymbol(),
&strVal)) {
str = strVal.toString();
} else {
str = nullptr;
}
} else if (exnObject && sniffingBehavior == NoSideEffects) {
str = cx->names().Object;
} else {
str = js::ToString<CanGC>(cx, exnStack.exception());
}
if (!str) {
cx->clearPendingException();
}
// If ErrorFromException didn't get us a JSErrorReport, then the object
// was not an ErrorObject, security-wrapped or otherwise. However, it might
// still quack like one. Give duck-typing a chance. We start by looking for
// "filename" (all lowercase), since that's where DOMExceptions store their
// filename. Then we check "fileName", which is where Errors store it. We
// have to do it in that order, because DOMExceptions have Error.prototype
// on their proto chain, and hence also have a "fileName" property, but its
// value is "".
const char* filename_str = "filename";
if (!reportp && exnObject && sniffingBehavior == WithSideEffects &&
IsDuckTypedErrorObject(cx, exnObject, &filename_str)) {
// Temporary value for pulling properties off of duck-typed objects.
RootedValue val(cx);
RootedString name(cx);
if (JS_GetProperty(cx, exnObject, "name", &val) && val.isString()) {
name = val.toString();
} else {
cx->clearPendingException();
}
RootedString msg(cx);
if (JS_GetProperty(cx, exnObject, "message", &val) && val.isString()) {
msg = val.toString();
} else {
cx->clearPendingException();
}
// If we have the right fields, override the ToString we performed on
// the exception object above with something built out of its quacks
// (i.e. as much of |NameQuack: MessageQuack| as we can make).
str = FormatErrorMessage(cx, name, msg);
{
AutoClearPendingException acpe(cx);
if (JS_GetProperty(cx, exnObject, filename_str, &val)) {
RootedString tmp(cx, js::ToString<CanGC>(cx, val));
if (tmp) {
filename = JS_EncodeStringToUTF8(cx, tmp);
}
}
}
if (!filename) {
filename = DuplicateString("");
if (!filename) {
ReportOutOfMemory(cx);
return false;
}
}
uint32_t lineno;
if (!JS_GetProperty(cx, exnObject, "lineNumber", &val) ||
!ToUint32(cx, val, &lineno)) {
cx->clearPendingException();
lineno = 0;
}
uint32_t column;
if (!JS_GetProperty(cx, exnObject, "columnNumber", &val) ||
!ToUint32(cx, val, &column)) {
cx->clearPendingException();
column = 0;
}
reportp = &ownedReport;
new (reportp) JSErrorReport();
ownedReport.filename = JS::ConstUTF8CharsZ(filename.get());
ownedReport.lineno = lineno;
ownedReport.exnType = JSEXN_INTERNALERR;
ownedReport.column = JS::ColumnNumberOneOrigin(column);
if (str) {
// Note that using |str| for |message_| here is kind of wrong,
// because |str| is supposed to be of the format
// |ErrorName: ErrorMessage|, and |message_| is supposed to
// correspond to |ErrorMessage|. But this is what we've
// historically done for duck-typed error objects.
//
// If only this stuff could get specced one day...
if (auto utf8 = JS_EncodeStringToUTF8(cx, str)) {
ownedReport.initOwnedMessage(utf8.release());
} else {
cx->clearPendingException();
str = nullptr;
}
}
}
const char* utf8Message = nullptr;
if (str) {
toStringResultBytesStorage = JS_EncodeStringToUTF8(cx, str);
utf8Message = toStringResultBytesStorage.get();
if (!utf8Message) {
cx->clearPendingException();
}
}
if (!utf8Message) {
utf8Message = "unknown (can't convert to string)";
}
if (!reportp) {
// This is basically an inlined version of
//
// JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
// JSMSG_UNCAUGHT_EXCEPTION, utf8Message);
//
// but without the reporting bits. Instead it just puts all
// the stuff we care about in our ownedReport and message_.
if (!populateUncaughtExceptionReportUTF8(cx, exnStack.stack(),
utf8Message)) {
// Just give up. We're out of memory or something; not much we can
// do here.
return false;
}
} else {
toStringResult_ = JS::ConstUTF8CharsZ(utf8Message, strlen(utf8Message));
}
return true;
}
bool JS::ErrorReportBuilder::populateUncaughtExceptionReportUTF8(
JSContext* cx, HandleObject stack, ...) {
va_list ap;
va_start(ap, stack);
bool ok = populateUncaughtExceptionReportUTF8VA(cx, stack, ap);
va_end(ap);
return ok;
}
bool JS::ErrorReportBuilder::populateUncaughtExceptionReportUTF8VA(
JSContext* cx, HandleObject stack, va_list ap) {
new (&ownedReport) JSErrorReport();
ownedReport.isWarning_ = false;
ownedReport.errorNumber = JSMSG_UNCAUGHT_EXCEPTION;
bool skippedAsync;
Rooted<SavedFrame*> frame(
cx, UnwrapSavedFrame(cx, cx->realm()->principals(), stack,
SavedFrameSelfHosted::Exclude, skippedAsync));
if (frame) {
filename = StringToNewUTF8CharsZ(cx, *frame->getSource());
if (!filename) {
return false;
}
// |ownedReport.filename| inherits the lifetime of |ErrorReport::filename|.
ownedReport.filename = JS::ConstUTF8CharsZ(filename.get());
ownedReport.sourceId = frame->getSourceId();
ownedReport.lineno = frame->getLine();
ownedReport.column =
JS::ColumnNumberOneOrigin(frame->getColumn().oneOriginValue());
ownedReport.isMuted = frame->getMutedErrors();
} else {
// XXXbz this assumes the stack we have right now is still
// related to our exception object.
NonBuiltinFrameIter iter(cx, cx->realm()->principals());
if (!iter.done()) {
ownedReport.filename = JS::ConstUTF8CharsZ(iter.filename());
JS::TaggedColumnNumberOneOrigin column;
ownedReport.sourceId =
iter.hasScript() ? iter.script()->scriptSource()->id() : 0;
ownedReport.lineno = iter.computeLine(&column);
ownedReport.column = JS::ColumnNumberOneOrigin(column.oneOriginValue());
ownedReport.isMuted = iter.mutedErrors();
}
}
AutoReportFrontendContext fc(cx);
if (!ExpandErrorArgumentsVA(&fc, GetErrorMessage, nullptr,
JSMSG_UNCAUGHT_EXCEPTION, ArgumentsAreUTF8,
&ownedReport, ap)) {
return false;
}
toStringResult_ = ownedReport.message();
reportp = &ownedReport;
return true;
}
JSObject* js::CopyErrorObject(JSContext* cx, Handle<ErrorObject*> err) {
UniquePtr<JSErrorReport> copyReport;
if (JSErrorReport* errorReport = err->getErrorReport()) {
copyReport = CopyErrorReport(cx, errorReport);
if (!copyReport) {
return nullptr;
}
}
RootedString message(cx, err->getMessage());
if (message && !cx->compartment()->wrap(cx, &message)) {
return nullptr;
}
RootedString fileName(cx, err->fileName(cx));
if (!cx->compartment()->wrap(cx, &fileName)) {
return nullptr;
}
RootedObject stack(cx, err->stack());
if (!cx->compartment()->wrap(cx, &stack)) {
return nullptr;
}
if (stack && JS_IsDeadWrapper(stack)) {
// ErrorObject::create expects |stack| to be either nullptr or a (possibly
// wrapped) SavedFrame instance.
stack = nullptr;
}
Rooted<mozilla::Maybe<Value>> cause(cx, mozilla::Nothing());
if (auto maybeCause = err->getCause()) {
RootedValue errorCause(cx, maybeCause.value());
if (!cx->compartment()->wrap(cx, &errorCause)) {
return nullptr;
}
cause = mozilla::Some(errorCause.get());
}
uint32_t sourceId = err->sourceId();
uint32_t lineNumber = err->lineNumber();
JS::ColumnNumberOneOrigin columnNumber = err->columnNumber();
JSExnType errorType = err->type();
// Create the Error object.
return ErrorObject::create(cx, errorType, stack, fileName, sourceId,
lineNumber, columnNumber, std::move(copyReport),
message, cause);
}
JS_PUBLIC_API bool JS::CreateError(JSContext* cx, JSExnType type,
HandleObject stack, HandleString fileName,
uint32_t lineNumber,
JS::ColumnNumberOneOrigin columnNumber,
JSErrorReport* report, HandleString message,
Handle<mozilla::Maybe<Value>> cause,
MutableHandleValue rval) {
cx->check(stack, fileName, message);
AssertObjectIsSavedFrameOrWrapper(cx, stack);
js::UniquePtr<JSErrorReport> rep;
if (report) {
rep = CopyErrorReport(cx, report);
if (!rep) {
return false;
}
}
JSObject* obj =
js::ErrorObject::create(cx, type, stack, fileName, 0, lineNumber,
columnNumber, std::move(rep), message, cause);
if (!obj) {
return false;
}
rval.setObject(*obj);
return true;
}
const char* js::ValueToSourceForError(JSContext* cx, HandleValue val,
UniqueChars& bytes) {
if (val.isUndefined()) {
return "undefined";
}
if (val.isNull()) {
return "null";
}
AutoClearPendingException acpe(cx);
// This function must always return a non-null string. If the conversion to
// string fails due to OOM, we return this string instead.
static constexpr char ErrorConvertingToStringMsg[] =
"<<error converting value to string>>";
RootedString str(cx, JS_ValueToSource(cx, val));
if (!str) {
return ErrorConvertingToStringMsg;
}
JSStringBuilder sb(cx);
if (val.hasObjectPayload()) {
RootedObject valObj(cx, &val.getObjectPayload());
ESClass cls;
if (!JS::GetBuiltinClass(cx, valObj, &cls)) {
return "<<error determining class of value>>";
}
const char* s;
if (cls == ESClass::Array) {
s = "the array ";
} else if (cls == ESClass::ArrayBuffer) {
s = "the array buffer ";
} else if (JS_IsArrayBufferViewObject(valObj)) {
s = "the typed array ";
#ifdef ENABLE_RECORD_TUPLE
} else if (cls == ESClass::Record) {
s = "the record ";
} else if (cls == ESClass::Tuple) {
s = "the tuple ";
#endif
} else {
s = "the object ";
}
if (!sb.append(s, strlen(s))) {
return ErrorConvertingToStringMsg;
}
} else if (val.isNumber()) {
if (!sb.append("the number ")) {
return ErrorConvertingToStringMsg;
}
} else if (val.isString()) {
if (!sb.append("the string ")) {
return ErrorConvertingToStringMsg;
}
} else if (val.isBigInt()) {
if (!sb.append("the BigInt ")) {
return ErrorConvertingToStringMsg;
}
} else {
MOZ_ASSERT(val.isBoolean() || val.isSymbol());
bytes = StringToNewUTF8CharsZ(cx, *str);
if (!bytes) {
return ErrorConvertingToStringMsg;
}
return bytes.get();
}
if (!sb.append(str)) {
return ErrorConvertingToStringMsg;
}
str = sb.finishString();
if (!str) {
return ErrorConvertingToStringMsg;
}
bytes = StringToNewUTF8CharsZ(cx, *str);
if (!bytes) {
return ErrorConvertingToStringMsg;
}
return bytes.get();
}
bool js::GetInternalError(JSContext* cx, unsigned errorNumber,
MutableHandleValue error) {
FixedInvokeArgs<1> args(cx);
args[0].set(Int32Value(errorNumber));
return CallSelfHostedFunction(cx, cx->names().GetInternalError,
NullHandleValue, args, error);
}
bool js::GetTypeError(JSContext* cx, unsigned errorNumber,
MutableHandleValue error) {
FixedInvokeArgs<1> args(cx);
args[0].set(Int32Value(errorNumber));
return CallSelfHostedFunction(cx, cx->names().GetTypeError, NullHandleValue,
args, error);
}
bool js::GetAggregateError(JSContext* cx, unsigned errorNumber,
MutableHandleValue error) {
FixedInvokeArgs<1> args(cx);
args[0].set(Int32Value(errorNumber));
return CallSelfHostedFunction(cx, cx->names().GetAggregateError,
NullHandleValue, args, error);
}
JS_PUBLIC_API mozilla::Maybe<Value> JS::GetExceptionCause(JSObject* exc) {
if (!exc->is<ErrorObject>()) {
return mozilla::Nothing();
}
auto& error = exc->as<ErrorObject>();
return error.getCause();
}