The Tor Browser: js/ipc/JavaScriptChild.cpp@b8a032363ba2 (annotated)

js/ipc/JavaScriptChild.cpp@b8a032363ba2 (annotated)

js/ipc/JavaScriptChild.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- 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);
 }

The Tor Browser / annotate

js/ipc/JavaScriptChild.cpp@b8a032363ba2 (annotated)

js/ipc/JavaScriptChild.cpp