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-rw-r--r--js/src/jsexn.cpp1021
1 files changed, 1021 insertions, 0 deletions
diff --git a/js/src/jsexn.cpp b/js/src/jsexn.cpp
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+++ b/js/src/jsexn.cpp
@@ -0,0 +1,1021 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+/*
+ * JS standard exception implementation.
+ */
+
+#include "jsexn.h"
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/PodOperations.h"
+#include "mozilla/Sprintf.h"
+
+#include <string.h>
+
+#include "jsapi.h"
+#include "jscntxt.h"
+#include "jsfun.h"
+#include "jsnum.h"
+#include "jsobj.h"
+#include "jsprf.h"
+#include "jsscript.h"
+#include "jstypes.h"
+#include "jsutil.h"
+#include "jswrapper.h"
+
+#include "gc/Marking.h"
+#include "js/CharacterEncoding.h"
+#include "vm/ErrorObject.h"
+#include "vm/GlobalObject.h"
+#include "vm/SavedStacks.h"
+#include "vm/StringBuffer.h"
+
+#include "jsobjinlines.h"
+
+#include "vm/ErrorObject-inl.h"
+#include "vm/SavedStacks-inl.h"
+
+using namespace js;
+using namespace js::gc;
+
+using mozilla::ArrayLength;
+using mozilla::PodArrayZero;
+
+static void
+exn_finalize(FreeOp* fop, JSObject* obj);
+
+bool
+Error(JSContext* cx, unsigned argc, Value* vp);
+
+static bool
+exn_toSource(JSContext* cx, unsigned argc, Value* vp);
+
+static const JSPropertySpec exception_properties[] = {
+ JS_PSGS("stack", ErrorObject::getStack, ErrorObject::setStack, 0),
+ JS_PS_END
+};
+
+static const JSFunctionSpec exception_methods[] = {
+#if JS_HAS_TOSOURCE
+ JS_FN(js_toSource_str, exn_toSource, 0, 0),
+#endif
+ JS_SELF_HOSTED_FN(js_toString_str, "ErrorToString", 0,0),
+ JS_FS_END
+};
+
+static const ClassOps ErrorObjectClassOps = {
+ nullptr, /* addProperty */
+ nullptr, /* delProperty */
+ nullptr, /* getProperty */
+ nullptr, /* setProperty */
+ nullptr, /* enumerate */
+ nullptr, /* resolve */
+ nullptr, /* mayResolve */
+ exn_finalize,
+ nullptr, /* call */
+ nullptr, /* hasInstance */
+ nullptr, /* construct */
+ nullptr, /* trace */
+};
+
+#define IMPLEMENT_ERROR_CLASS(name, classSpecPtr) \
+ { \
+ js_Error_str, /* yes, really */ \
+ JSCLASS_HAS_CACHED_PROTO(JSProto_##name) | \
+ JSCLASS_HAS_RESERVED_SLOTS(ErrorObject::RESERVED_SLOTS) | \
+ JSCLASS_BACKGROUND_FINALIZE, \
+ &ErrorObjectClassOps, \
+ classSpecPtr \
+ }
+
+const ClassSpec
+ErrorObject::errorClassSpec_ = {
+ ErrorObject::createConstructor,
+ ErrorObject::createProto,
+ nullptr,
+ nullptr,
+ exception_methods,
+ exception_properties,
+ nullptr,
+ 0
+};
+
+const ClassSpec
+ErrorObject::subErrorClassSpec_ = {
+ ErrorObject::createConstructor,
+ ErrorObject::createProto,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr,
+ JSProto_Error
+};
+
+const ClassSpec
+ErrorObject::nonGlobalErrorClassSpec_ = {
+ ErrorObject::createConstructor,
+ ErrorObject::createProto,
+ nullptr,
+ nullptr,
+ exception_methods,
+ exception_properties,
+ nullptr,
+ JSProto_Error | ClassSpec::DontDefineConstructor
+};
+
+const Class
+ErrorObject::classes[JSEXN_LIMIT] = {
+ IMPLEMENT_ERROR_CLASS(Error, &ErrorObject::errorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(InternalError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(EvalError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(RangeError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(ReferenceError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(SyntaxError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(TypeError, &ErrorObject::subErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(URIError, &ErrorObject::subErrorClassSpec_),
+
+ // These Error subclasses are not accessible via the global object:
+ IMPLEMENT_ERROR_CLASS(DebuggeeWouldRun, &ErrorObject::nonGlobalErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(CompileError, &ErrorObject::nonGlobalErrorClassSpec_),
+ IMPLEMENT_ERROR_CLASS(RuntimeError, &ErrorObject::nonGlobalErrorClassSpec_)
+};
+
+JSErrorReport*
+js::CopyErrorReport(JSContext* cx, JSErrorReport* report)
+{
+ /*
+ * We use a single malloc block to make a deep copy of JSErrorReport with
+ * the following layout:
+ * JSErrorReport
+ * char array with characters for message_
+ * char16_t array with characters for linebuf
+ * char array with characters for filename
+ * Such layout together with the properties enforced by the following
+ * asserts does not need any extra alignment padding.
+ */
+ JS_STATIC_ASSERT(sizeof(JSErrorReport) % sizeof(const char*) == 0);
+ JS_STATIC_ASSERT(sizeof(const char*) % sizeof(char16_t) == 0);
+
+#define JS_CHARS_SIZE(chars) ((js_strlen(chars) + 1) * sizeof(char16_t))
+
+ size_t filenameSize = report->filename ? strlen(report->filename) + 1 : 0;
+ size_t linebufSize = 0;
+ if (report->linebuf())
+ linebufSize = (report->linebufLength() + 1) * sizeof(char16_t);
+ 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(JSErrorReport) + messageSize + linebufSize + filenameSize;
+ uint8_t* cursor = cx->pod_calloc<uint8_t>(mallocSize);
+ if (!cursor)
+ return nullptr;
+
+ JSErrorReport* copy = (JSErrorReport*)cursor;
+ cursor += sizeof(JSErrorReport);
+
+ if (report->message()) {
+ copy->initBorrowedMessage((const char*)cursor);
+ js_memcpy(cursor, report->message().c_str(), messageSize);
+ cursor += messageSize;
+ }
+
+ if (report->linebuf()) {
+ const char16_t* linebufCopy = (const char16_t*)cursor;
+ js_memcpy(cursor, report->linebuf(), linebufSize);
+ cursor += linebufSize;
+ copy->initBorrowedLinebuf(linebufCopy, report->linebufLength(), report->tokenOffset());
+ }
+
+ if (report->filename) {
+ copy->filename = (const char*)cursor;
+ js_memcpy(cursor, report->filename, filenameSize);
+ }
+ MOZ_ASSERT(cursor + filenameSize == (uint8_t*)copy + mallocSize);
+
+ /* Copy non-pointer members. */
+ copy->isMuted = report->isMuted;
+ copy->lineno = report->lineno;
+ copy->column = report->column;
+ copy->errorNumber = report->errorNumber;
+ copy->exnType = report->exnType;
+
+ /* Note that this is before it gets flagged with JSREPORT_EXCEPTION */
+ copy->flags = report->flags;
+
+#undef JS_CHARS_SIZE
+ return copy;
+}
+
+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;
+
+static bool
+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, stack, &str))
+ return nullptr;
+
+ return str.get();
+}
+
+static void
+exn_finalize(FreeOp* fop, JSObject* obj)
+{
+ MOZ_ASSERT(fop->maybeOffMainThread());
+ if (JSErrorReport* report = obj->as<ErrorObject>().getErrorReport())
+ fop->free_(report);
+}
+
+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*)
+ExceptionStackOrNull(HandleObject objArg)
+{
+ JSObject* obj = CheckedUnwrap(objArg);
+ if (!obj || !obj->is<ErrorObject>()) {
+ return nullptr;
+ }
+
+ return obj->as<ErrorObject>().stack();
+}
+
+bool
+Error(JSContext* cx, unsigned argc, Value* vp)
+{
+ CallArgs args = CallArgsFromVp(argc, vp);
+
+ // ES6 19.5.1.1 mandates the .prototype lookup happens before the toString
+ RootedObject proto(cx);
+ if (!GetPrototypeFromCallableConstructor(cx, args, &proto))
+ return false;
+
+ /* Compute the error message, if any. */
+ RootedString message(cx, nullptr);
+ if (args.hasDefined(0)) {
+ message = ToString<CanGC>(cx, args[0]);
+ if (!message)
+ return false;
+ }
+
+ /* Find the scripted caller, but only ones we're allowed to know about. */
+ NonBuiltinFrameIter iter(cx, cx->compartment()->principals());
+
+ /* Set the 'fileName' property. */
+ RootedString fileName(cx);
+ if (args.length() > 1) {
+ fileName = ToString<CanGC>(cx, args[1]);
+ } else {
+ fileName = cx->runtime()->emptyString;
+ if (!iter.done()) {
+ if (const char* cfilename = iter.filename())
+ fileName = JS_NewStringCopyZ(cx, cfilename);
+ }
+ }
+ if (!fileName)
+ return false;
+
+ /* Set the 'lineNumber' property. */
+ uint32_t lineNumber, columnNumber = 0;
+ if (args.length() > 2) {
+ if (!ToUint32(cx, args[2], &lineNumber))
+ return false;
+ } else {
+ lineNumber = iter.done() ? 0 : iter.computeLine(&columnNumber);
+ // XXX: Make the column 1-based as in other browsers, instead of 0-based
+ // which is how SpiderMonkey stores it internally. This will be
+ // unnecessary once bug 1144340 is fixed.
+ ++columnNumber;
+ }
+
+ RootedObject stack(cx);
+ if (!CaptureStack(cx, &stack))
+ return false;
+
+ /*
+ * ECMA ed. 3, 15.11.1 requires Error, etc., to construct even when
+ * called as functions, without operator new. But as we do not give
+ * each constructor a distinct JSClass, we must get the exception type
+ * ourselves.
+ */
+ JSExnType exnType = JSExnType(args.callee().as<JSFunction>().getExtendedSlot(0).toInt32());
+
+ RootedObject obj(cx, ErrorObject::create(cx, exnType, stack, fileName,
+ lineNumber, columnNumber, nullptr, message, proto));
+ if (!obj)
+ return false;
+
+ args.rval().setObject(*obj);
+ return true;
+}
+
+#if JS_HAS_TOSOURCE
+/*
+ * Return a string that may eval to something similar to the original object.
+ */
+static bool
+exn_toSource(JSContext* cx, unsigned argc, Value* vp)
+{
+ JS_CHECK_RECURSION(cx, return false);
+ CallArgs args = CallArgsFromVp(argc, vp);
+
+ RootedObject obj(cx, ToObject(cx, args.thisv()));
+ if (!obj)
+ return false;
+
+ RootedValue nameVal(cx);
+ RootedString name(cx);
+ if (!GetProperty(cx, obj, obj, cx->names().name, &nameVal) ||
+ !(name = ToString<CanGC>(cx, nameVal)))
+ {
+ return false;
+ }
+
+ RootedValue messageVal(cx);
+ RootedString message(cx);
+ if (!GetProperty(cx, obj, obj, cx->names().message, &messageVal) ||
+ !(message = ValueToSource(cx, messageVal)))
+ {
+ return false;
+ }
+
+ RootedValue filenameVal(cx);
+ RootedString filename(cx);
+ if (!GetProperty(cx, obj, obj, cx->names().fileName, &filenameVal) ||
+ !(filename = ValueToSource(cx, filenameVal)))
+ {
+ return false;
+ }
+
+ RootedValue linenoVal(cx);
+ uint32_t lineno;
+ if (!GetProperty(cx, obj, obj, cx->names().lineNumber, &linenoVal) ||
+ !ToUint32(cx, linenoVal, &lineno))
+ {
+ return false;
+ }
+
+ StringBuffer sb(cx);
+ if (!sb.append("(new ") || !sb.append(name) || !sb.append("("))
+ return false;
+
+ if (!sb.append(message))
+ return false;
+
+ if (!filename->empty()) {
+ if (!sb.append(", ") || !sb.append(filename))
+ return false;
+ }
+ if (lineno != 0) {
+ /* We have a line, but no filename, add empty string */
+ if (filename->empty() && !sb.append(", \"\""))
+ return false;
+
+ JSString* linenumber = ToString<CanGC>(cx, linenoVal);
+ if (!linenumber)
+ return false;
+ if (!sb.append(", ") || !sb.append(linenumber))
+ return false;
+ }
+
+ if (!sb.append("))"))
+ return false;
+
+ JSString* str = sb.finishString();
+ if (!str)
+ return false;
+ args.rval().setString(str);
+ return true;
+}
+#endif
+
+/* static */ JSObject*
+ErrorObject::createProto(JSContext* cx, JSProtoKey key)
+{
+ RootedObject errorProto(cx, GenericCreatePrototype(cx, key));
+ if (!errorProto)
+ return nullptr;
+
+ Rooted<ErrorObject*> err(cx, &errorProto->as<ErrorObject>());
+ RootedString emptyStr(cx, cx->names().empty);
+ JSExnType type = ExnTypeFromProtoKey(key);
+ if (!ErrorObject::init(cx, err, type, nullptr, emptyStr, nullptr, 0, 0, emptyStr))
+ return nullptr;
+
+ // The various prototypes also have .name in addition to the normal error
+ // instance properties.
+ RootedPropertyName name(cx, ClassName(key, cx));
+ RootedValue nameValue(cx, StringValue(name));
+ if (!DefineProperty(cx, err, cx->names().name, nameValue, nullptr, nullptr, 0))
+ return nullptr;
+
+ return errorProto;
+}
+
+/* static */ JSObject*
+ErrorObject::createConstructor(JSContext* cx, JSProtoKey key)
+{
+ RootedObject ctor(cx);
+ ctor = GenericCreateConstructor<Error, 1, gc::AllocKind::FUNCTION_EXTENDED>(cx, key);
+ if (!ctor)
+ return nullptr;
+
+ ctor->as<JSFunction>().setExtendedSlot(0, Int32Value(ExnTypeFromProtoKey(key)));
+ return ctor;
+}
+
+JS_FRIEND_API(JSFlatString*)
+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)
+ {
+ return nullptr;
+ }
+ JSProtoKey key = GetExceptionProtoKey(JSExnType(exnType));
+ return ClassName(key, cx);
+}
+
+void
+js::ErrorToException(JSContext* cx, JSErrorReport* reportp,
+ JSErrorCallback callback, void* userRef)
+{
+ MOZ_ASSERT(reportp);
+ MOZ_ASSERT(!JSREPORT_IS_WARNING(reportp->flags));
+
+ // We cannot throw a proper object inside the self-hosting compartment, as
+ // we cannot construct the Error constructor without self-hosted code. Just
+ // print the error to stderr to help debugging.
+ if (cx->runtime()->isSelfHostingCompartment(cx->compartment())) {
+ PrintError(cx, stderr, JS::ConstUTF8CharsZ(), reportp, true);
+ return;
+ }
+
+ // 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_LIMIT);
+
+ if (exnType == JSEXN_WARN) {
+ // werror must be enabled, so we use JSEXN_ERR.
+ MOZ_ASSERT(cx->options().werror());
+ exnType = JSEXN_ERR;
+ }
+
+ // Prevent infinite recursion.
+ if (cx->generatingError)
+ return;
+ AutoScopedAssign<bool> asa(&cx->generatingError, true);
+
+ // Create an exception object.
+ RootedString messageStr(cx, reportp->newMessageString(cx));
+ if (!messageStr)
+ return;
+
+ RootedString fileName(cx, JS_NewStringCopyZ(cx, reportp->filename));
+ if (!fileName)
+ return;
+
+ uint32_t lineNumber = reportp->lineno;
+ uint32_t columnNumber = reportp->column;
+
+ RootedObject stack(cx);
+ if (!CaptureStack(cx, &stack))
+ return;
+
+ js::ScopedJSFreePtr<JSErrorReport> report(CopyErrorReport(cx, reportp));
+ if (!report)
+ return;
+
+ RootedObject errObject(cx, ErrorObject::create(cx, exnType, stack, fileName,
+ lineNumber, columnNumber, &report, messageStr));
+ if (!errObject)
+ return;
+
+ // Throw it.
+ cx->setPendingException(ObjectValue(*errObject));
+
+ // Flag the error report passed in to indicate an exception was raised.
+ reportp->flags |= JSREPORT_EXCEPTION;
+}
+
+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, js_message_str, &found) || !found)
+ return false;
+
+ const char* filename_str = *filename_strp;
+ if (!JS_HasProperty(cx, exnObject, filename_str, &found) || !found) {
+ /* Now try "fileName", in case this quacks like an Error */
+ filename_str = js_fileName_str;
+ if (!JS_HasProperty(cx, exnObject, filename_str, &found) || !found)
+ return false;
+ }
+
+ if (!JS_HasProperty(cx, exnObject, js_lineNumber_str, &found) || !found)
+ return false;
+
+ *filename_strp = filename_str;
+ return true;
+}
+
+static JSString*
+ErrorReportToString(JSContext* cx, JSErrorReport* reportp)
+{
+ /*
+ * 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.
+ */
+ JSExnType type = static_cast<JSExnType>(reportp->exnType);
+ RootedString str(cx);
+ if (type != JSEXN_WARN)
+ str = ClassName(GetExceptionProtoKey(type), cx);
+
+ /*
+ * If "str" is null at this point, that means we just want to use
+ * message without prefixing it with anything.
+ */
+ if (str) {
+ RootedString separator(cx, JS_NewUCStringCopyN(cx, u": ", 2));
+ if (!separator)
+ return nullptr;
+ str = ConcatStrings<CanGC>(cx, str, separator);
+ if (!str)
+ return nullptr;
+ }
+
+ RootedString message(cx, reportp->newMessageString(cx));
+ if (!message)
+ return nullptr;
+
+ if (!str)
+ return message;
+
+ return ConcatStrings<CanGC>(cx, str, message);
+}
+
+ErrorReport::ErrorReport(JSContext* cx)
+ : reportp(nullptr),
+ str(cx),
+ strChars(cx),
+ exnObject(cx)
+{
+}
+
+ErrorReport::~ErrorReport()
+{
+}
+
+void
+ErrorReport::ReportAddonExceptionToTelementry(JSContext* cx)
+{
+ MOZ_ASSERT(exnObject);
+ RootedObject unwrapped(cx, UncheckedUnwrap(exnObject));
+ MOZ_ASSERT(unwrapped, "UncheckedUnwrap failed?");
+
+ // There is not much we can report if the exception is not an ErrorObject, let's ignore those.
+ if (!unwrapped->is<ErrorObject>())
+ return;
+
+ Rooted<ErrorObject*> errObj(cx, &unwrapped->as<ErrorObject>());
+ RootedObject stack(cx, errObj->stack());
+
+ // Let's ignore TOP level exceptions. For regular add-ons those will not be reported anyway,
+ // for SDK based once it should not be a valid case either.
+ // At this point the frame stack is unwound but the exception object stored the stack so let's
+ // use that for getting the function name.
+ if (!stack)
+ return;
+
+ JSCompartment* comp = stack->compartment();
+ JSAddonId* addonId = comp->creationOptions().addonIdOrNull();
+
+ // We only want to send the report if the scope that just have thrown belongs to an add-on.
+ // Let's check the compartment of the youngest function on the stack, to determine that.
+ if (!addonId)
+ return;
+
+ RootedString funnameString(cx);
+ JS::SavedFrameResult result = GetSavedFrameFunctionDisplayName(cx, stack, &funnameString);
+ // AccessDenied should never be the case here for add-ons but let's not risk it.
+ JSAutoByteString bytes;
+ const char* funname = nullptr;
+ bool denied = result == JS::SavedFrameResult::AccessDenied;
+ funname = denied ? "unknown"
+ : funnameString ? AtomToPrintableString(cx,
+ &funnameString->asAtom(),
+ &bytes)
+ : "anonymous";
+
+ UniqueChars addonIdChars(JS_EncodeString(cx, addonId));
+
+ const char* filename = nullptr;
+ if (reportp && reportp->filename) {
+ filename = strrchr(reportp->filename, '/');
+ if (filename)
+ filename++;
+ }
+ if (!filename) {
+ filename = "FILE_NOT_FOUND";
+ }
+ char histogramKey[64];
+ SprintfLiteral(histogramKey, "%s %s %s %u",
+ addonIdChars.get(),
+ funname,
+ filename,
+ (reportp ? reportp->lineno : 0) );
+ cx->runtime()->addTelemetry(JS_TELEMETRY_ADDON_EXCEPTIONS, 1, histogramKey);
+}
+
+bool
+ErrorReport::init(JSContext* cx, HandleValue exn,
+ SniffingBehavior sniffingBehavior)
+{
+ MOZ_ASSERT(!cx->isExceptionPending());
+ MOZ_ASSERT(!reportp);
+
+ if (exn.isObject()) {
+ // Because ToString below could error and an exception object could become
+ // unrooted, we must root our exception object, if any.
+ exnObject = &exn.toObject();
+ reportp = ErrorFromException(cx, exnObject);
+
+ if (!reportp && sniffingBehavior == NoSideEffects) {
+ JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+ JSMSG_ERR_DURING_THROW);
+ return false;
+ }
+
+ // Let's see if the exception is from add-on code, if so, it should be reported
+ // to telementry.
+ ReportAddonExceptionToTelementry(cx);
+ }
+
+
+ // 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.
+ if (reportp) {
+ str = ErrorReportToString(cx, reportp);
+ } else if (exn.isSymbol()) {
+ RootedValue strVal(cx);
+ if (js::SymbolDescriptiveString(cx, exn.toSymbol(), &strVal))
+ str = strVal.toString();
+ else
+ str = nullptr;
+ } else {
+ str = ToString<CanGC>(cx, exn);
+ }
+
+ 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 && 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, js_name_str, &val) && val.isString())
+ name = val.toString();
+ else
+ cx->clearPendingException();
+
+ RootedString msg(cx);
+ if (JS_GetProperty(cx, exnObject, js_message_str, &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).
+ //
+ // It would be nice to use ErrorReportToString here, but we can't quite
+ // do it - mostly because we'd need to figure out what JSExnType |name|
+ // corresponds to, which may not be any JSExnType at all.
+ if (name && msg) {
+ RootedString colon(cx, JS_NewStringCopyZ(cx, ": "));
+ if (!colon)
+ return false;
+ RootedString nameColon(cx, ConcatStrings<CanGC>(cx, name, colon));
+ if (!nameColon)
+ return false;
+ str = ConcatStrings<CanGC>(cx, nameColon, msg);
+ if (!str)
+ return false;
+ } else if (name) {
+ str = name;
+ } else if (msg) {
+ str = msg;
+ }
+
+ if (JS_GetProperty(cx, exnObject, filename_str, &val)) {
+ RootedString tmp(cx, ToString<CanGC>(cx, val));
+ if (tmp)
+ filename.encodeUtf8(cx, tmp);
+ else
+ cx->clearPendingException();
+ } else {
+ cx->clearPendingException();
+ }
+
+ uint32_t lineno;
+ if (!JS_GetProperty(cx, exnObject, js_lineNumber_str, &val) ||
+ !ToUint32(cx, val, &lineno))
+ {
+ cx->clearPendingException();
+ lineno = 0;
+ }
+
+ uint32_t column;
+ if (!JS_GetProperty(cx, exnObject, js_columnNumber_str, &val) ||
+ !ToUint32(cx, val, &column))
+ {
+ cx->clearPendingException();
+ column = 0;
+ }
+
+ reportp = &ownedReport;
+ new (reportp) JSErrorReport();
+ ownedReport.filename = filename.ptr();
+ ownedReport.lineno = lineno;
+ ownedReport.exnType = JSEXN_INTERNALERR;
+ ownedReport.column = 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...
+ char* utf8;
+ if (str->ensureFlat(cx) &&
+ strChars.initTwoByte(cx, str) &&
+ (utf8 = JS::CharsToNewUTF8CharsZ(cx, strChars.twoByteRange()).c_str()))
+ {
+ ownedReport.initOwnedMessage(utf8);
+ } else {
+ cx->clearPendingException();
+ str = nullptr;
+ }
+ }
+ }
+
+ const char* utf8Message = nullptr;
+ if (str)
+ utf8Message = toStringResultBytesStorage.encodeUtf8(cx, str);
+ 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, 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));
+ /* Flag the error as an exception. */
+ reportp->flags |= JSREPORT_EXCEPTION;
+ }
+
+ return true;
+}
+
+bool
+ErrorReport::populateUncaughtExceptionReportUTF8(JSContext* cx, ...)
+{
+ va_list ap;
+ va_start(ap, cx);
+ bool ok = populateUncaughtExceptionReportUTF8VA(cx, ap);
+ va_end(ap);
+ return ok;
+}
+
+bool
+ErrorReport::populateUncaughtExceptionReportUTF8VA(JSContext* cx, va_list ap)
+{
+ new (&ownedReport) JSErrorReport();
+ ownedReport.flags = JSREPORT_ERROR;
+ ownedReport.errorNumber = JSMSG_UNCAUGHT_EXCEPTION;
+ // XXXbz this assumes the stack we have right now is still
+ // related to our exception object. It would be better if we
+ // could accept a passed-in stack of some sort instead.
+ NonBuiltinFrameIter iter(cx, cx->compartment()->principals());
+ if (!iter.done()) {
+ ownedReport.filename = iter.filename();
+ ownedReport.lineno = iter.computeLine(&ownedReport.column);
+ // XXX: Make the column 1-based as in other browsers, instead of 0-based
+ // which is how SpiderMonkey stores it internally. This will be
+ // unnecessary once bug 1144340 is fixed.
+ ++ownedReport.column;
+ ownedReport.isMuted = iter.mutedErrors();
+ }
+
+ if (!ExpandErrorArgumentsVA(cx, GetErrorMessage, nullptr,
+ JSMSG_UNCAUGHT_EXCEPTION,
+ nullptr, ArgumentsAreUTF8, &ownedReport, ap)) {
+ return false;
+ }
+
+ toStringResult_ = ownedReport.message();
+ reportp = &ownedReport;
+ return true;
+}
+
+JSObject*
+js::CopyErrorObject(JSContext* cx, Handle<ErrorObject*> err)
+{
+ js::ScopedJSFreePtr<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;
+ uint32_t lineNumber = err->lineNumber();
+ uint32_t columnNumber = err->columnNumber();
+ JSExnType errorType = err->type();
+
+ // Create the Error object.
+ return ErrorObject::create(cx, errorType, stack, fileName,
+ lineNumber, columnNumber, &copyReport, message);
+}
+
+JS_PUBLIC_API(bool)
+JS::CreateError(JSContext* cx, JSExnType type, HandleObject stack, HandleString fileName,
+ uint32_t lineNumber, uint32_t columnNumber, JSErrorReport* report,
+ HandleString message, MutableHandleValue rval)
+{
+ assertSameCompartment(cx, stack, fileName, message);
+ AssertObjectIsSavedFrameOrWrapper(cx, stack);
+
+ js::ScopedJSFreePtr<JSErrorReport> rep;
+ if (report)
+ rep = CopyErrorReport(cx, report);
+
+ RootedObject obj(cx,
+ js::ErrorObject::create(cx, type, stack, fileName,
+ lineNumber, columnNumber, &rep, message));
+ if (!obj)
+ return false;
+
+ rval.setObject(*obj);
+ return true;
+}
+
+const char*
+js::ValueToSourceForError(JSContext* cx, HandleValue val, JSAutoByteString& bytes)
+{
+ if (val.isUndefined())
+ return "undefined";
+
+ if (val.isNull())
+ return "null";
+
+ AutoClearPendingException acpe(cx);
+
+ RootedString str(cx, JS_ValueToSource(cx, val));
+ if (!str)
+ return "<<error converting value to string>>";
+
+ StringBuffer sb(cx);
+ if (val.isObject()) {
+ RootedObject valObj(cx, val.toObjectOrNull());
+ ESClass cls;
+ if (!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 ";
+ else
+ s = "the object ";
+ if (!sb.append(s, strlen(s)))
+ return "<<error converting value to string>>";
+ } else if (val.isNumber()) {
+ if (!sb.append("the number "))
+ return "<<error converting value to string>>";
+ } else if (val.isString()) {
+ if (!sb.append("the string "))
+ return "<<error converting value to string>>";
+ } else {
+ MOZ_ASSERT(val.isBoolean() || val.isSymbol());
+ return bytes.encodeLatin1(cx, str);
+ }
+ if (!sb.append(str))
+ return "<<error converting value to string>>";
+ str = sb.finishString();
+ if (!str)
+ return "<<error converting value to string>>";
+ return bytes.encodeLatin1(cx, str);
+}