// static
JSObject*
DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isUndefined()) {
return nullptr;
}
if (v.isObject()) {
js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, UndefinedValue());
xpc::GetObjectScope(obj)->RemoveDOMExpandoObject(obj);
} else {
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
if (v.isUndefined()) {
return nullptr;
}
expandoAndGeneration->expando = UndefinedValue();
}
return &v.toObject();
}
void HostReleaseTopLevelScript(const JS::Value& aPrivate) {
// Decrement the reference count of a LoadedScript object that was pointed to
// by a JSScript. The reference count was originally incremented by
// HostAddRefTopLevelScript() above.
auto script = static_cast<LoadedScript*>(aPrivate.toPrivate());
CheckModuleScriptPrivate(script, aPrivate);
script->Release();
}
/**
* Extract the FinalizationEvent from an instance of FinalizationWitness
* and clear the slot containing the FinalizationEvent.
*/
already_AddRefed<FinalizationEvent>
ExtractFinalizationEvent(JSObject *objSelf)
{
JS::Value slotEvent = JS_GetReservedSlot(objSelf, WITNESS_SLOT_EVENT);
if (slotEvent.isUndefined()) {
// Forget() has been called
return nullptr;
}
JS_SetReservedSlot(objSelf, WITNESS_SLOT_EVENT, JS::UndefinedValue());
return dont_AddRef(static_cast<FinalizationEvent*>(slotEvent.toPrivate()));
}
void ShadowingDOMProxyHandler::trace(JSTracer* trc, JSObject* proxy) const {
DOMProxyHandler::trace(trc, proxy);
MOZ_ASSERT(IsDOMProxy(proxy), "expected a DOM proxy object");
JS::Value v = js::GetProxyPrivate(proxy);
MOZ_ASSERT(!v.isObject(), "Should not have expando object directly!");
// The proxy's private slot is set when we allocate the proxy,
// so it cannot be |undefined|.
MOZ_ASSERT(!v.isUndefined());
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
JS::TraceEdge(trc, &expandoAndGeneration->expando,
"Shadowing DOM proxy expando");
}
// static
JSObject*
DOMProxyHandler::EnsureExpandoObject(JSContext* cx, JS::Handle<JSObject*> obj)
{
NS_ASSERTION(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isObject()) {
return &v.toObject();
}
js::ExpandoAndGeneration* expandoAndGeneration;
if (!v.isUndefined()) {
expandoAndGeneration = static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
if (expandoAndGeneration->expando.isObject()) {
return &expandoAndGeneration->expando.toObject();
}
} else {
expandoAndGeneration = nullptr;
}
JS::Rooted<JSObject*> expando(cx,
JS_NewObjectWithGivenProto(cx, nullptr, nullptr, js::GetObjectParent(obj)));
if (!expando) {
return nullptr;
}
nsISupports* native = UnwrapDOMObject<nsISupports>(obj);
nsWrapperCache* cache;
CallQueryInterface(native, &cache);
if (expandoAndGeneration) {
cache->PreserveWrapper(native);
expandoAndGeneration->expando.setObject(*expando);
return expando;
}
XPCWrappedNativeScope* scope = xpc::GetObjectScope(obj);
if (!scope->RegisterDOMExpandoObject(obj)) {
return nullptr;
}
cache->SetPreservingWrapper(true);
js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, ObjectValue(*expando));
return expando;
}
//static
JSObject *
DOMProxyHandler::GetExpandoObject(JSObject *obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isObject()) {
return &v.toObject();
}
if (v.isUndefined()) {
return nullptr;
}
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
return v.isUndefined() ? nullptr : &v.toObject();
}
// static
JSObject* DOMProxyHandler::EnsureExpandoObject(JSContext* cx,
JS::Handle<JSObject*> obj) {
CheckDOMProxy(obj);
JS::Value v = js::GetProxyPrivate(obj);
if (v.isObject()) {
CheckExpandoObject(obj, v);
return &v.toObject();
}
js::ExpandoAndGeneration* expandoAndGeneration;
if (!v.isUndefined()) {
expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
CheckExpandoAndGeneration(obj, expandoAndGeneration);
if (expandoAndGeneration->expando.isObject()) {
return &expandoAndGeneration->expando.toObject();
}
} else {
expandoAndGeneration = nullptr;
}
JS::Rooted<JSObject*> expando(
cx, JS_NewObjectWithGivenProto(cx, nullptr, nullptr));
if (!expando) {
return nullptr;
}
nsISupports* native = UnwrapDOMObject<nsISupports>(obj);
nsWrapperCache* cache;
CallQueryInterface(native, &cache);
cache->PreserveWrapper(native);
if (expandoAndGeneration) {
expandoAndGeneration->expando.setObject(*expando);
return expando;
}
js::SetProxyPrivate(obj, ObjectValue(*expando));
return expando;
}
// static
JSObject* DOMProxyHandler::GetExpandoObject(JSObject* obj) {
CheckDOMProxy(obj);
JS::Value v = js::GetProxyPrivate(obj);
if (v.isObject()) {
CheckExpandoObject(obj, v);
return &v.toObject();
}
if (v.isUndefined()) {
return nullptr;
}
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
CheckExpandoAndGeneration(obj, expandoAndGeneration);
v = expandoAndGeneration->expando;
return v.isUndefined() ? nullptr : &v.toObject();
}
// static
JSObject*
DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyPrivate(obj);
if (v.isUndefined()) {
return nullptr;
}
if (v.isObject()) {
js::SetProxyPrivate(obj, UndefinedValue());
} else {
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
if (v.isUndefined()) {
return nullptr;
}
// We have to expose v to active JS here. The reason for that is that we
// might be in the middle of a GC right now. If our proxy hasn't been
// traced yet, when it _does_ get traced it won't trace the expando, since
// we're breaking that link. But the Rooted we're presumably being placed
// into is also not going to trace us, because Rooted marking is done at
// the very beginning of the GC. In that situation, we need to manually
// mark the expando as live here. JS::ExposeValueToActiveJS will do just
// that for us.
//
// We don't need to do this in the non-expandoAndGeneration case, because
// in that case our value is stored in a slot and slots will already mark
// the old thing live when the value in the slot changes.
JS::ExposeValueToActiveJS(v);
expandoAndGeneration->expando = UndefinedValue();
}
return &v.toObject();
}
// static
JSObject* DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj) {
CheckDOMProxy(obj);
JS::Value v = js::GetProxyPrivate(obj);
if (v.isUndefined()) {
return nullptr;
}
if (v.isObject()) {
js::SetProxyPrivate(obj, UndefinedValue());
} else {
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
if (v.isUndefined()) {
return nullptr;
}
expandoAndGeneration->expando = UndefinedValue();
}
CheckExpandoObject(obj, v);
return &v.toObject();
}
// Define a shadowing property on |this| for the XBL field defined by the
// contents of the callee's reserved slots. If the property was defined,
// *installed will be true, and idp will be set to the property name that was
// defined.
static bool
InstallXBLField(JSContext* cx,
JS::Handle<JSObject*> callee, JS::Handle<JSObject*> thisObj,
JS::MutableHandle<jsid> idp, bool* installed)
{
*installed = false;
// First ensure |this| is a reasonable XBL bound node.
//
// FieldAccessorGuard already determined whether |thisObj| was acceptable as
// |this| in terms of not throwing a TypeError. Assert this for good measure.
MOZ_ASSERT(ValueHasISupportsPrivate(JS::ObjectValue(*thisObj)));
// But there are some cases where we must accept |thisObj| but not install a
// property on it, or otherwise touch it. Hence this split of |this|-vetting
// duties.
nsISupports* native =
nsContentUtils::XPConnect()->GetNativeOfWrapper(cx, thisObj);
if (!native) {
// Looks like whatever |thisObj| is it's not our nsIContent. It might well
// be the proto our binding installed, however, where the private is the
// nsXBLDocumentInfo, so just baul out quietly. Do NOT throw an exception
// here.
//
// We could make this stricter by checking the class maybe, but whatever.
return true;
}
nsCOMPtr<nsIContent> xblNode = do_QueryInterface(native);
if (!xblNode) {
xpc::Throw(cx, NS_ERROR_UNEXPECTED);
return false;
}
// Now that |this| is okay, actually install the field.
// Because of the possibility (due to XBL binding inheritance, because each
// XBL binding lives in its own global object) that |this| might be in a
// different compartment from the callee (not to mention that this method can
// be called with an arbitrary |this| regardless of how insane XBL is), and
// because in this method we've entered |this|'s compartment (see in
// Field[GS]etter where we attempt a cross-compartment call), we must enter
// the callee's compartment to access its reserved slots.
nsXBLPrototypeBinding* protoBinding;
nsDependentJSString fieldName;
{
JSAutoCompartment ac(cx, callee);
JS::Rooted<JSObject*> xblProto(cx);
xblProto = &js::GetFunctionNativeReserved(callee, XBLPROTO_SLOT).toObject();
JS::Rooted<JS::Value> name(cx, js::GetFunctionNativeReserved(callee, FIELD_SLOT));
JSFlatString* fieldStr = JS_ASSERT_STRING_IS_FLAT(name.toString());
fieldName.init(fieldStr);
MOZ_ALWAYS_TRUE(JS_ValueToId(cx, name, idp.address()));
// If a separate XBL scope is being used, the callee is not same-compartment
// with the xbl prototype, and the object is a cross-compartment wrapper.
xblProto = js::UncheckedUnwrap(xblProto);
JSAutoCompartment ac2(cx, xblProto);
JS::Value slotVal = ::JS_GetReservedSlot(xblProto, 0);
protoBinding = static_cast<nsXBLPrototypeBinding*>(slotVal.toPrivate());
MOZ_ASSERT(protoBinding);
}
nsXBLProtoImplField* field = protoBinding->FindField(fieldName);
MOZ_ASSERT(field);
// This mirrors code in nsXBLProtoImpl::InstallImplementation
nsCOMPtr<nsIScriptGlobalObject> global =
do_QueryInterface(xblNode->OwnerDoc()->GetWindow());
if (!global) {
return true;
}
nsCOMPtr<nsIScriptContext> context = global->GetContext();
if (!context) {
return true;
}
nsresult rv = field->InstallField(context, thisObj, protoBinding->DocURI(),
installed);
if (NS_SUCCEEDED(rv)) {
return true;
}
if (!::JS_IsExceptionPending(cx)) {
xpc::Throw(cx, rv);
}
return false;
}