bool
JSCompartment::wrap(JSContext *cx, MutableHandle<PropDesc> desc)
{
if (desc.isUndefined())
return true;
JSCompartment *comp = cx->compartment();
if (desc.hasValue()) {
RootedValue value(cx, desc.value());
if (!comp->wrap(cx, &value))
return false;
desc.setValue(value);
}
if (desc.hasGet()) {
RootedValue get(cx, desc.getterValue());
if (!comp->wrap(cx, &get))
return false;
desc.setGetter(get);
}
if (desc.hasSet()) {
RootedValue set(cx, desc.setterValue());
if (!comp->wrap(cx, &set))
return false;
desc.setSetter(set);
}
return true;
}
/*
* Rewrap *idp and the fields of *desc for the current compartment. Also:
* defining a property on a proxy requires pd_ to contain a descriptor object,
* so reconstitute desc->pd_ if needed.
*/
bool
PropDesc::wrapInto(JSContext *cx, HandleObject obj, const jsid &id, jsid *wrappedId,
PropDesc *desc) const
{
MOZ_ASSERT(!isUndefined());
JSCompartment *comp = cx->compartment;
*wrappedId = id;
if (!comp->wrapId(cx, wrappedId))
return false;
*desc = *this;
RootedValue value(cx, desc->value_);
RootedValue get(cx, desc->get_);
RootedValue set(cx, desc->set_);
if (!comp->wrap(cx, &value) || !comp->wrap(cx, &get) || !comp->wrap(cx, &set))
return false;
desc->value_ = value;
desc->get_ = get;
desc->set_ = set;
return !obj->isProxy() || desc->makeObject(cx);
}
// Given a cross-compartment wrapper |wobj|, update it to point to
// |newTarget|. This recomputes the wrapper with JS_WrapValue, and thus can be
// useful even if wrapper already points to newTarget.
bool
js::RemapWrapper(JSContext *cx, JSObject *wobjArg, JSObject *newTargetArg)
{
RootedObject wobj(cx, wobjArg);
RootedObject newTarget(cx, newTargetArg);
JS_ASSERT(IsCrossCompartmentWrapper(wobj));
JS_ASSERT(!IsCrossCompartmentWrapper(newTarget));
JSObject *origTarget = Wrapper::wrappedObject(wobj);
JS_ASSERT(origTarget);
Value origv = ObjectValue(*origTarget);
JSCompartment *wcompartment = wobj->compartment();
AutoDisableProxyCheck adpc(cx->runtime);
// If we're mapping to a different target (as opposed to just recomputing
// for the same target), we must not have an existing wrapper for the new
// target, otherwise this will break.
JS_ASSERT_IF(origTarget != newTarget,
!wcompartment->lookupWrapper(ObjectValue(*newTarget)));
// The old value should still be in the cross-compartment wrapper map, and
// the lookup should return wobj.
WrapperMap::Ptr p = wcompartment->lookupWrapper(origv);
JS_ASSERT(&p->value.unsafeGet()->toObject() == wobj);
wcompartment->removeWrapper(p);
// When we remove origv from the wrapper map, its wrapper, wobj, must
// immediately cease to be a cross-compartment wrapper. Neuter it.
NukeCrossCompartmentWrapper(cx, wobj);
// First, we wrap it in the new compartment. We try to use the existing
// wrapper, |wobj|, since it's been nuked anyway. The wrap() function has
// the choice to reuse |wobj| or not.
RootedObject tobj(cx, newTarget);
AutoCompartment ac(cx, wobj);
if (!wcompartment->wrap(cx, tobj.address(), wobj))
MOZ_CRASH();
// If wrap() reused |wobj|, it will have overwritten it and returned with
// |tobj == wobj|. Otherwise, |tobj| will point to a new wrapper and |wobj|
// will still be nuked. In the latter case, we replace |wobj| with the
// contents of the new wrapper in |tobj|.
if (tobj != wobj) {
// Now, because we need to maintain object identity, we do a brain
// transplant on the old object so that it contains the contents of the
// new one.
if (!JSObject::swap(cx, wobj, tobj))
MOZ_CRASH();
}
// Before swapping, this wrapper came out of wrap(), which enforces the
// invariant that the wrapper in the map points directly to the key.
JS_ASSERT(Wrapper::wrappedObject(wobj) == newTarget);
// Update the entry in the compartment's wrapper map to point to the old
// wrapper, which has now been updated (via reuse or swap).
JS_ASSERT(wobj->isWrapper());
wcompartment->putWrapper(ObjectValue(*newTarget), ObjectValue(*wobj));
return true;
}
/*
* Rewrap *idp and the fields of *desc for the current compartment. Also:
* defining a property on a proxy requires pd_ to contain a descriptor object,
* so reconstitute desc->pd_ if needed.
*/
bool
PropDesc::wrapInto(JSContext *cx, JSObject *obj, const jsid &id, jsid *wrappedId,
PropDesc *desc) const
{
MOZ_ASSERT(!isUndefined());
JSCompartment *comp = cx->compartment;
*wrappedId = id;
if (!comp->wrapId(cx, wrappedId))
return false;
*desc = *this;
if (!comp->wrap(cx, &desc->value_))
return false;
if (!comp->wrap(cx, &desc->get_))
return false;
if (!comp->wrap(cx, &desc->set_))
return false;
return !obj->isProxy() || desc->makeObject(cx);
}
// Given a cross-compartment wrapper |wobj|, update it to point to
// |newTarget|. This recomputes the wrapper with JS_WrapValue, and thus can be
// useful even if wrapper already points to newTarget.
bool
js::RemapWrapper(JSContext *cx, JSObject *wobj, JSObject *newTarget)
{
JS_ASSERT(IsCrossCompartmentWrapper(wobj));
JS_ASSERT(!IsCrossCompartmentWrapper(newTarget));
JSObject *origTarget = Wrapper::wrappedObject(wobj);
JS_ASSERT(origTarget);
Value origv = ObjectValue(*origTarget);
JSCompartment *wcompartment = wobj->compartment();
WrapperMap &pmap = wcompartment->crossCompartmentWrappers;
// If we're mapping to a different target (as opposed to just recomputing
// for the same target), we must not have an existing wrapper for the new
// target, otherwise this will break.
JS_ASSERT_IF(origTarget != newTarget, !pmap.has(ObjectValue(*newTarget)));
// The old value should still be in the cross-compartment wrapper map, and
// the lookup should return wobj.
JS_ASSERT(&pmap.lookup(origv)->value.toObject() == wobj);
pmap.remove(origv);
// When we remove origv from the wrapper map, its wrapper, wobj, must
// immediately cease to be a cross-compartment wrapper. Neuter it.
NukeCrossCompartmentWrapper(wobj);
// First, we wrap it in the new compartment. This will return
// a new wrapper.
AutoCompartment ac(cx, wobj);
JSObject *tobj = newTarget;
if (!ac.enter() || !wcompartment->wrap(cx, &tobj))
return false;
// Now, because we need to maintain object identity, we do a
// brain transplant on the old object. At the same time, we
// update the entry in the compartment's wrapper map to point
// to the old wrapper.
JS_ASSERT(tobj != wobj);
if (!wobj->swap(cx, tobj))
return false;
// Before swapping, this wrapper came out of wrap(), which enforces the
// invariant that the wrapper in the map points directly to the key.
JS_ASSERT(Wrapper::wrappedObject(wobj) == newTarget);
pmap.put(ObjectValue(*newTarget), ObjectValue(*wobj));
return true;
}