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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

  * vim: set ts=4 sw=4 et tw=80:

  *

  * 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/. */

 #include "JavaScriptChild.h"

 #include "mozilla/dom/ContentChild.h"

 #include "mozilla/dom/BindingUtils.h"

 #include "nsContentUtils.h"

 #include "xpcprivate.h"

 #include "jsfriendapi.h"

 #include "nsCxPusher.h"

 using namespace JS;

 using namespace mozilla;

 using namespace mozilla::jsipc;

 using mozilla::AutoSafeJSContext;

 JavaScriptChild::JavaScriptChild(JSRuntime *rt)

   : lastId_(0),

     rt_(rt)

 {

 }

 static void

 Trace(JSTracer *trc, void *data)

 {

     reinterpret_cast<JavaScriptChild *>(data)->trace(trc);

 }

 JavaScriptChild::~JavaScriptChild()

 {

     JS_RemoveExtraGCRootsTracer(rt_, Trace, this);

 }

 void

 JavaScriptChild::trace(JSTracer *trc)

 {

     objects_.trace(trc);

     ids_.trace(trc);

 }

 bool

 JavaScriptChild::init()

 {

     if (!JavaScriptShared::init())

         return false;

     if (!ids_.init())

         return false;

     JS_AddExtraGCRootsTracer(rt_, Trace, this);

     return true;

 }

 bool

 JavaScriptChild::RecvDropObject(const ObjectId &objId)

 {

     JSObject *obj = findObject(objId);

     if (obj) {

         ids_.remove(obj);

         objects_.remove(objId);

     }

     return true;

 }

 bool

 JavaScriptChild::makeId(JSContext *cx, JSObject *obj, ObjectId *idp)

 {

     if (!obj) {

         *idp = 0;

         return true;

     }

     ObjectId id = ids_.find(obj);

     if (id) {

         *idp = id;

         return true;

     }

     id = ++lastId_;

     if (id > MAX_CPOW_IDS) {

         JS_ReportError(cx, "CPOW id limit reached");

         return false;

     }

     id <<= OBJECT_EXTRA_BITS;

     if (JS_ObjectIsCallable(cx, obj))

         id |= OBJECT_IS_CALLABLE;

     if (!objects_.add(id, obj))

         return false;

     if (!ids_.add(cx, obj, id))

         return false;

     *idp = id;

     return true;

 }

 JSObject *

 JavaScriptChild::unwrap(JSContext *cx, ObjectId id)

 {

     JSObject *obj = findObject(id);

     MOZ_ASSERT(obj);

     return obj;

 }

 bool

 JavaScriptChild::fail(JSContext *cx, ReturnStatus *rs)

 {

     // By default, we set |undefined| unless we can get a more meaningful

     // exception.

     *rs = ReturnStatus(ReturnException(JSVariant(void_t())));

     // Note we always return true from this function, since this propagates

     // to the IPC code, and we don't want a JS failure to cause the death

     // of the child process.

     RootedValue exn(cx);

     if (!JS_GetPendingException(cx, &exn))

         return true;

     // If we don't clear the pending exception, JS will try to wrap it as it

     // leaves the current compartment. Since there is no previous compartment,

     // that would crash.

     JS_ClearPendingException(cx);

     if (JS_IsStopIteration(exn)) {

         *rs = ReturnStatus(ReturnStopIteration());

         return true;

     }

     // If this fails, we still don't want to exit. Just return an invalid

     // exception.

     (void) toVariant(cx, exn, &rs->get_ReturnException().exn());

     return true;

 }

 bool

 JavaScriptChild::ok(ReturnStatus *rs)

 {

     *rs = ReturnStatus(ReturnSuccess());

     return true;

 }

 bool

 JavaScriptChild::AnswerPreventExtensions(const ObjectId &objId, ReturnStatus *rs)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     if (!JS_PreventExtensions(cx, obj))

         return fail(cx, rs);

     return ok(rs);

 }

 static void

 EmptyDesc(PPropertyDescriptor *desc)

 {

     desc->objId() = 0;

     desc->attrs() = 0;

     desc->value() = void_t();

     desc->getter() = 0;

     desc->setter() = 0;

 }

 bool

 JavaScriptChild::AnswerGetPropertyDescriptor(const ObjectId &objId, const nsString &id,

                                              ReturnStatus *rs, PPropertyDescriptor *out)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     EmptyDesc(out);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     Rooted<JSPropertyDescriptor> desc(cx);

     if (!JS_GetPropertyDescriptorById(cx, obj, internedId, &desc))

         return fail(cx, rs);

     if (!desc.object())

         return ok(rs);

     if (!fromDescriptor(cx, desc, out))

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerGetOwnPropertyDescriptor(const ObjectId &objId, const nsString &id,

                                                 ReturnStatus *rs, PPropertyDescriptor *out)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     EmptyDesc(out);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     Rooted<JSPropertyDescriptor> desc(cx);

     if (!JS_GetPropertyDescriptorById(cx, obj, internedId, &desc))

         return fail(cx, rs);

     if (desc.object() != obj)

         return ok(rs);

     if (!fromDescriptor(cx, desc, out))

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerDefineProperty(const ObjectId &objId, const nsString &id,

                                       const PPropertyDescriptor &descriptor, ReturnStatus *rs)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     Rooted<JSPropertyDescriptor> desc(cx);

     if (!toDescriptor(cx, descriptor, &desc))

         return false;

     if (!js::CheckDefineProperty(cx, obj, internedId, desc.value(), desc.getter(),

                                  desc.setter(), desc.attributes()))

     {

         return fail(cx, rs);

     }

     if (!JS_DefinePropertyById(cx, obj, internedId, desc.value(), desc.getter(),

                                desc.setter(), desc.attributes()))

     {

         return fail(cx, rs);

     }

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerDelete(const ObjectId &objId, const nsString &id, ReturnStatus *rs,

                               bool *success)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *success = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     if (!JS_DeletePropertyById2(cx, obj, internedId, success))

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerHas(const ObjectId &objId, const nsString &id, ReturnStatus *rs, bool *bp)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *bp = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     bool found;

     if (!JS_HasPropertyById(cx, obj, internedId, &found))

         return fail(cx, rs);

     *bp = !!found;

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerHasOwn(const ObjectId &objId, const nsString &id, ReturnStatus *rs, bool *bp)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *bp = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     Rooted<JSPropertyDescriptor> desc(cx);

     if (!JS_GetPropertyDescriptorById(cx, obj, internedId, &desc))

         return fail(cx, rs);

     *bp = (desc.object() == obj);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerGet(const ObjectId &objId, const ObjectId &receiverId, const nsString &id,

                            ReturnStatus *rs, JSVariant *result)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     // The outparam will be written to the buffer, so it must be set even if

     // the parent won't read it.

     *result = void_t();

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     RootedObject receiver(cx, findObject(receiverId));

     if (!receiver)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     JS::RootedValue val(cx);

     if (!JS_ForwardGetPropertyTo(cx, obj, internedId, receiver, &val))

         return fail(cx, rs);

     if (!toVariant(cx, val, result))

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerSet(const ObjectId &objId, const ObjectId &receiverId, const nsString &id,

                            const bool &strict, const JSVariant &value, ReturnStatus *rs,

                            JSVariant *result)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     // The outparam will be written to the buffer, so it must be set even if

     // the parent won't read it.

     *result = void_t();

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     RootedObject receiver(cx, findObject(receiverId));

     if (!receiver)

         return false;

     JSAutoCompartment comp(cx, obj);

     RootedId internedId(cx);

     if (!convertGeckoStringToId(cx, id, &internedId))

         return fail(cx, rs);

     MOZ_ASSERT(obj == receiver);

     RootedValue val(cx);

     if (!toValue(cx, value, &val))

         return fail(cx, rs);

     if (!JS_SetPropertyById(cx, obj, internedId, val))

         return fail(cx, rs);

     if (!toVariant(cx, val, result))

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerIsExtensible(const ObjectId &objId, ReturnStatus *rs, bool *result)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *result = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     bool extensible;

     if (!JS_IsExtensible(cx, obj, &extensible))

         return fail(cx, rs);

     *result = !!extensible;

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerCall(const ObjectId &objId, const nsTArray<JSParam> &argv, ReturnStatus *rs,

                             JSVariant *result, nsTArray<JSParam> *outparams)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     // The outparam will be written to the buffer, so it must be set even if

     // the parent won't read it.

     *result = void_t();

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     MOZ_ASSERT(argv.Length() >= 2);

     RootedValue objv(cx);

     if (!toValue(cx, argv[0], &objv))

         return fail(cx, rs);

     JSAutoCompartment comp(cx, &objv.toObject());

     *result = JSVariant(void_t());

     AutoValueVector vals(cx);

     AutoValueVector outobjects(cx);

     for (size_t i = 0; i < argv.Length(); i++) {

         if (argv[i].type() == JSParam::Tvoid_t) {

             // This is an outparam.

             JSCompartment *compartment = js::GetContextCompartment(cx);

             RootedObject global(cx, JS_GetGlobalForCompartmentOrNull(cx, compartment));

             RootedObject obj(cx, xpc::NewOutObject(cx, global));

             if (!obj)

                 return fail(cx, rs);

             if (!outobjects.append(ObjectValue(*obj)))

                 return fail(cx, rs);

             if (!vals.append(ObjectValue(*obj)))

                 return fail(cx, rs);

         } else {

             RootedValue v(cx);

             if (!toValue(cx, argv[i].get_JSVariant(), &v))

                 return fail(cx, rs);

             if (!vals.append(v))

                 return fail(cx, rs);

         }

     }

     RootedValue rval(cx);

     {

         AutoSaveContextOptions asco(cx);

         ContextOptionsRef(cx).setDontReportUncaught(true);

         HandleValueArray args = HandleValueArray::subarray(vals, 2, vals.length() - 2);

         bool success = JS::Call(cx, vals.handleAt(1), vals.handleAt(0), args, &rval);

         if (!success)

             return fail(cx, rs);

     }

     if (!toVariant(cx, rval, result))

         return fail(cx, rs);

     // Prefill everything with a dummy jsval.

     for (size_t i = 0; i < outobjects.length(); i++)

         outparams->AppendElement(JSParam(void_t()));

     // Go through each argument that was an outparam, retrieve the "value"

     // field, and add it to a temporary list. We need to do this separately

     // because the outparams vector is not rooted.

     vals.clear();

     for (size_t i = 0; i < outobjects.length(); i++) {

         RootedObject obj(cx, &outobjects[i].toObject());

         RootedValue v(cx);

         bool found;

         if (JS_HasProperty(cx, obj, "value", &found)) {

             if (!JS_GetProperty(cx, obj, "value", &v))

                 return fail(cx, rs);

         } else {

             v = UndefinedValue();

         }

         if (!vals.append(v))

             return fail(cx, rs);

     }

     // Copy the outparams. If any outparam is already set to a void_t, we

     // treat this as the outparam never having been set.

     for (size_t i = 0; i < vals.length(); i++) {

         JSVariant variant;

         if (!toVariant(cx, vals.handleAt(i), &variant))

             return fail(cx, rs);

         outparams->ReplaceElementAt(i, JSParam(variant));

     }

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerObjectClassIs(const ObjectId &objId, const uint32_t &classValue,

                                      bool *result)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     *result = js_ObjectClassIs(cx, obj, (js::ESClassValue)classValue);

     return true;

 }

 bool

 JavaScriptChild::AnswerClassName(const ObjectId &objId, nsString *name)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     *name = NS_ConvertASCIItoUTF16(js_ObjectClassName(cx, obj));

     return true;

 }

 bool

 JavaScriptChild::AnswerGetPropertyNames(const ObjectId &objId, const uint32_t &flags,

                                         ReturnStatus *rs, nsTArray<nsString> *names)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     AutoIdVector props(cx);

     if (!js::GetPropertyNames(cx, obj, flags, &props))

         return fail(cx, rs);

     for (size_t i = 0; i < props.length(); i++) {

         nsString name;

         if (!convertIdToGeckoString(cx, props.handleAt(i), &name))

             return fail(cx, rs);

         names->AppendElement(name);

     }

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerInstanceOf(const ObjectId &objId, const JSIID &iid, ReturnStatus *rs,

                                   bool *instanceof)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *instanceof = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     nsID nsiid;

     ConvertID(iid, &nsiid);

     nsresult rv = xpc::HasInstance(cx, obj, &nsiid, instanceof);

     if (rv != NS_OK)

         return fail(cx, rs);

     return ok(rs);

 }

 bool

 JavaScriptChild::AnswerDOMInstanceOf(const ObjectId &objId, const int &prototypeID,

                                      const int &depth,

                                      ReturnStatus *rs, bool *instanceof)

 {

     AutoSafeJSContext cx;

     JSAutoRequest request(cx);

     *instanceof = false;

     RootedObject obj(cx, findObject(objId));

     if (!obj)

         return false;

     JSAutoCompartment comp(cx, obj);

     bool tmp;

     if (!mozilla::dom::InterfaceHasInstance(cx, prototypeID, depth, obj, &tmp))

         return fail(cx, rs);

     *instanceof = tmp;

     return ok(rs);

 }