gecko/js/ipc/JavaScriptChild.cpp

628 lines
15 KiB
C++

/* -*- 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 "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(false, 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.
jsval exn;
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 (!toVariant(cx, exn, &rs->exn()))
return true;
return true;
}
bool
JavaScriptChild::ok(ReturnStatus *rs)
{
*rs = ReturnStatus(true, JSVariant(void_t()));
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->shortid() = 0;
desc->value() = void_t();
desc->getter() = 0;
desc->setter() = 0;
}
bool
JavaScriptChild::AnswerGetPropertyDescriptor(const ObjectId &objId, const nsString &id,
const uint32_t &flags, 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);
JSPropertyDescriptor desc;
if (!JS_GetPropertyDescriptorById(cx, obj, internedId, flags, &desc))
return fail(cx, rs);
if (!desc.obj)
return ok(rs);
if (!fromDescriptor(cx, desc, out))
return fail(cx, rs);
return ok(rs);
}
bool
JavaScriptChild::AnswerGetOwnPropertyDescriptor(const ObjectId &objId, const nsString &id,
const uint32_t &flags, 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);
JSPropertyDescriptor desc;
if (!JS_GetPropertyDescriptorById(cx, obj, internedId, flags, &desc))
return fail(cx, rs);
if (desc.obj != 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);
JSPropertyDescriptor desc;
if (!toDescriptor(cx, descriptor, &desc))
return false;
RootedValue v(cx, desc.value);
if (!js::CheckDefineProperty(cx, obj, internedId, v, desc.getter, desc.setter, desc.attrs) ||
!JS_DefinePropertyById(cx, obj, internedId, v, desc.getter, desc.setter, desc.attrs))
{
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);
RootedValue v(cx);
if (!JS_DeletePropertyById2(cx, obj, internedId, &v))
return fail(cx, rs);
JSBool b;
if (!JS_ValueToBoolean(cx, v, &b))
return fail(cx, rs);
*success = !!b;
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);
JSBool 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);
JSPropertyDescriptor desc;
if (!JS_GetPropertyDescriptorById(cx, obj, internedId, 0, &desc))
return fail(cx, rs);
*bp = (desc.obj == 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::Rooted<JS::Value> 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;
JSBool 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);
}
}
uint32_t oldOpts =
JS_SetOptions(cx, JS_GetOptions(cx) | JSOPTION_DONT_REPORT_UNCAUGHT);
RootedValue rval(cx);
bool success = JS::Call(cx, vals[1], vals[0], vals.length() - 2, vals.begin() + 2, &rval);
JS_SetOptions(cx, oldOpts);
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);
JSBool 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[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);
}