JS_SetWatchPoint(JSContext *cx, JSObject *obj_, jsid id_,
                 JSWatchPointHandler handler, JSObject *closure_)
{
    assertSameCompartment(cx, obj_);

    RootedId id(cx, id_);
    RootedObject origobj(cx, obj_), closure(cx, closure_);
    RootedObject obj(cx, GetInnerObject(cx, origobj));
    if (!obj)
        return false;

    RootedValue v(cx);
    unsigned attrs;

    RootedId propid(cx);

    if (JSID_IS_INT(id)) {
        propid = id;
    } else if (JSID_IS_OBJECT(id)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CANT_WATCH_PROP);
        return false;
    } else {
        RootedValue val(cx, IdToValue(id));
        if (!ValueToId<CanGC>(cx, val, &propid))
            return false;
    }

    /*
     * If, by unwrapping and innerizing, we changed the object, check
     * again to make sure that we're allowed to set a watch point.
     */
    if (origobj != obj && !CheckAccess(cx, obj, propid, JSACC_WATCH, &v, &attrs))
        return false;

    if (!obj->isNative()) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CANT_WATCH,
                             obj->getClass()->name);
        return false;
    }

    /*
     * Use sparse indexes for watched objects, as dense elements can be written
     * to without checking the watchpoint map.
     */
    if (!JSObject::sparsifyDenseElements(cx, obj))
        return false;

    types::MarkTypePropertyConfigured(cx, obj, propid);

    WatchpointMap *wpmap = cx->compartment()->watchpointMap;
    if (!wpmap) {
        wpmap = cx->runtime()->new_<WatchpointMap>();
        if (!wpmap || !wpmap->init()) {
            js_ReportOutOfMemory(cx);
            return false;
        }
        cx->compartment()->watchpointMap = wpmap;
    }
    return wpmap->watch(cx, obj, propid, handler, closure);
}

JS_SetWatchPoint(JSContext *cx, JSObject *obj_, jsid id,
                 JSWatchPointHandler handler, JSObject *closure_)
{
    assertSameCompartment(cx, obj_);

    RootedObject obj(cx, obj_), closure(cx, closure_);

    JSObject *origobj = obj;
    obj = GetInnerObject(cx, obj);
    if (!obj)
        return false;

    RootedValue v(cx);
    unsigned attrs;

    RootedId propid(cx);

    if (JSID_IS_INT(id)) {
        propid = id;
    } else if (JSID_IS_OBJECT(id)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CANT_WATCH_PROP);
        return false;
    } else {
        if (!ValueToId(cx, IdToValue(id), propid.address()))
            return false;
    }

    /*
     * If, by unwrapping and innerizing, we changed the object, check
     * again to make sure that we're allowed to set a watch point.
     */
    if (origobj != obj && !CheckAccess(cx, obj, propid, JSACC_WATCH, &v, &attrs))
        return false;

    if (!obj->isNative()) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CANT_WATCH,
                             obj->getClass()->name);
        return false;
    }

    types::MarkTypePropertyConfigured(cx, obj, propid);

    WatchpointMap *wpmap = cx->compartment->watchpointMap;
    if (!wpmap) {
        wpmap = cx->runtime->new_<WatchpointMap>();
        if (!wpmap || !wpmap->init()) {
            js_ReportOutOfMemory(cx);
            return false;
        }
        cx->compartment->watchpointMap = wpmap;
    }
    return wpmap->watch(cx, obj, propid, handler, closure);
}

bool
WatchpointMap::markAllIteratively(JSTracer *trc)
{
    JSRuntime *rt = trc->context->runtime;
    if (rt->gcCurrentCompartment) {
        WatchpointMap *wpmap = rt->gcCurrentCompartment->watchpointMap;
        return wpmap && wpmap->markIteratively(trc);
    }

    bool mutated = false;
    for (JSCompartment **c = rt->compartments.begin(); c != rt->compartments.end(); ++c) {
        if ((*c)->watchpointMap)
            mutated |= (*c)->watchpointMap->markIteratively(trc);
    }
    return mutated;
}