static bool
CloneValue(JSContext *cx, MutableHandleValue vp, CloneMemory &clonedObjects)
{
    if (vp.isObject()) {
        RootedObject obj(cx, &vp.toObject());
        RootedObject clone(cx, CloneObject(cx, obj, clonedObjects));
        if (!clone)
            return false;
        vp.setObject(*clone);
    } else if (vp.isBoolean() || vp.isNumber() || vp.isNullOrUndefined()) {
        // Nothing to do here: these are represented inline in the value
    } else if (vp.isString()) {
        Rooted<JSStableString*> str(cx, vp.toString()->ensureStable(cx));
        if (!str)
            return false;
        RootedString clone(cx, js_NewStringCopyN<CanGC>(cx, str->chars().get(), str->length()));
        if (!clone)
            return false;
        vp.setString(clone);
    } else {
        MOZ_ASSUME_UNREACHABLE("Self-hosting CloneValue can't clone given value.");
    }
    return true;
}
Exemple #2
0
bool
JSCompartment::wrap(JSContext *cx, MutableHandleValue vp, HandleObject existingArg)
{
    JS_ASSERT(cx->compartment == this);
    JS_ASSERT_IF(existingArg, existingArg->compartment() == cx->compartment);
    JS_ASSERT_IF(existingArg, vp.isObject());
    JS_ASSERT_IF(existingArg, IsDeadProxyObject(existingArg));

    unsigned flags = 0;

    JS_CHECK_CHROME_RECURSION(cx, return false);

#ifdef DEBUG
    struct AutoDisableProxyCheck {
        JSRuntime *runtime;
        AutoDisableProxyCheck(JSRuntime *rt) : runtime(rt) {
            runtime->gcDisableStrictProxyCheckingCount++;
        }
        ~AutoDisableProxyCheck() { runtime->gcDisableStrictProxyCheckingCount--; }
    } adpc(rt);
#endif

    /* Only GC things have to be wrapped or copied. */
    if (!vp.isMarkable())
        return true;

    if (vp.isString()) {
        RawString str = vp.toString();

        /* If the string is already in this compartment, we are done. */
        if (str->zone() == zone())
            return true;

        /* If the string is an atom, we don't have to copy. */
        if (str->isAtom()) {
            JS_ASSERT(str->zone() == cx->runtime->atomsCompartment->zone());
            return true;
        }
    }

    /*
     * Wrappers should really be parented to the wrapped parent of the wrapped
     * object, but in that case a wrapped global object would have a NULL
     * parent without being a proper global object (JSCLASS_IS_GLOBAL). Instead,
     * we parent all wrappers to the global object in their home compartment.
     * This loses us some transparency, and is generally very cheesy.
     */
    HandleObject global = cx->global();

    /* Unwrap incoming objects. */
    if (vp.isObject()) {
        RootedObject obj(cx, &vp.toObject());

        if (obj->compartment() == this)
            return WrapForSameCompartment(cx, obj, vp);

        /* Translate StopIteration singleton. */
        if (obj->isStopIteration())
            return js_FindClassObject(cx, JSProto_StopIteration, vp);

        /* Unwrap the object, but don't unwrap outer windows. */
        obj = UnwrapObject(obj, /* stopAtOuter = */ true, &flags);

        if (obj->compartment() == this)
            return WrapForSameCompartment(cx, obj, vp);

        if (cx->runtime->preWrapObjectCallback) {
            obj = cx->runtime->preWrapObjectCallback(cx, global, obj, flags);
            if (!obj)
                return false;
        }

        if (obj->compartment() == this)
            return WrapForSameCompartment(cx, obj, vp);
        vp.setObject(*obj);

#ifdef DEBUG
        {
            JSObject *outer = GetOuterObject(cx, obj);
            JS_ASSERT(outer && outer == obj);
        }
#endif
    }

    RootedValue key(cx, vp);

    /* If we already have a wrapper for this value, use it. */
    if (WrapperMap::Ptr p = crossCompartmentWrappers.lookup(key)) {
        vp.set(p->value);
        if (vp.isObject()) {
            RawObject obj = &vp.toObject();
            JS_ASSERT(obj->isCrossCompartmentWrapper());
            JS_ASSERT(obj->getParent() == global);
        }
        return true;
    }

    if (vp.isString()) {
        Rooted<JSLinearString *> str(cx, vp.toString()->ensureLinear(cx));
        if (!str)
            return false;

        UnrootedString wrapped = js_NewStringCopyN<CanGC>(cx, str->chars(), str->length());
        if (!wrapped)
            return false;

        vp.setString(wrapped);
        if (!putWrapper(key, vp))
            return false;

        if (str->zone()->isGCMarking()) {
            /*
             * All string wrappers are dropped when collection starts, but we
             * just created a new one.  Mark the wrapped string to stop it being
             * finalized, because if it was then the pointer in this
             * compartment's wrapper map would be left dangling.
             */
            JSString *tmp = str;
            MarkStringUnbarriered(&rt->gcMarker, &tmp, "wrapped string");
            JS_ASSERT(tmp == str);
        }

        return true;
    }

    RootedObject proto(cx, Proxy::LazyProto);
    RootedObject obj(cx, &vp.toObject());
    RootedObject existing(cx, existingArg);
    if (existing) {
        /* Is it possible to reuse |existing|? */
        if (!existing->getTaggedProto().isLazy() ||
            existing->getClass() != &ObjectProxyClass ||
            existing->getParent() != global ||
            obj->isCallable())
        {
            existing = NULL;
        }
    }

    /*
     * We hand in the original wrapped object into the wrap hook to allow
     * the wrap hook to reason over what wrappers are currently applied
     * to the object.
     */
    RootedObject wrapper(cx);
    wrapper = cx->runtime->wrapObjectCallback(cx, existing, obj, proto, global, flags);
    if (!wrapper)
        return false;

    // We maintain the invariant that the key in the cross-compartment wrapper
    // map is always directly wrapped by the value.
    JS_ASSERT(Wrapper::wrappedObject(wrapper) == &key.get().toObject());

    vp.setObject(*wrapper);
    return putWrapper(key, vp);
}