1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/DOMJSProxyHandler.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,371 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * vim: set ts=2 sw=2 et tw=99 ft=cpp: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.8 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "mozilla/dom/DOMJSProxyHandler.h"
1.11 +#include "xpcpublic.h"
1.12 +#include "xpcprivate.h"
1.13 +#include "XPCQuickStubs.h"
1.14 +#include "XPCWrapper.h"
1.15 +#include "WrapperFactory.h"
1.16 +#include "nsDOMClassInfo.h"
1.17 +#include "nsWrapperCacheInlines.h"
1.18 +#include "mozilla/dom/BindingUtils.h"
1.19 +
1.20 +#include "jsapi.h"
1.21 +
1.22 +using namespace JS;
1.23 +
1.24 +namespace mozilla {
1.25 +namespace dom {
1.26 +
1.27 +jsid s_length_id = JSID_VOID;
1.28 +
1.29 +bool
1.30 +DefineStaticJSVals(JSContext* cx)
1.31 +{
1.32 + return InternJSString(cx, s_length_id, "length");
1.33 +}
1.34 +
1.35 +
1.36 +const char HandlerFamily = 0;
1.37 +
1.38 +js::DOMProxyShadowsResult
1.39 +DOMProxyShadows(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id)
1.40 +{
1.41 + JS::Value v = js::GetProxyExtra(proxy, JSPROXYSLOT_EXPANDO);
1.42 + if (v.isObject()) {
1.43 + bool hasOwn;
1.44 + Rooted<JSObject*> object(cx, &v.toObject());
1.45 + if (!JS_AlreadyHasOwnPropertyById(cx, object, id, &hasOwn))
1.46 + return js::ShadowCheckFailed;
1.47 +
1.48 + return hasOwn ? js::Shadows : js::DoesntShadow;
1.49 + }
1.50 +
1.51 + if (v.isUndefined()) {
1.52 + return js::DoesntShadow;
1.53 + }
1.54 +
1.55 + bool hasOwn;
1.56 + if (!GetProxyHandler(proxy)->hasOwn(cx, proxy, id, &hasOwn))
1.57 + return js::ShadowCheckFailed;
1.58 +
1.59 + return hasOwn ? js::Shadows : js::DoesntShadowUnique;
1.60 +}
1.61 +
1.62 +// Store the information for the specialized ICs.
1.63 +struct SetDOMProxyInformation
1.64 +{
1.65 + SetDOMProxyInformation() {
1.66 + js::SetDOMProxyInformation((const void*) &HandlerFamily,
1.67 + js::PROXY_EXTRA_SLOT + JSPROXYSLOT_EXPANDO, DOMProxyShadows);
1.68 + }
1.69 +};
1.70 +
1.71 +SetDOMProxyInformation gSetDOMProxyInformation;
1.72 +
1.73 +// static
1.74 +JSObject*
1.75 +DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
1.76 +{
1.77 + MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
1.78 + JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
1.79 + if (v.isUndefined()) {
1.80 + return nullptr;
1.81 + }
1.82 +
1.83 + if (v.isObject()) {
1.84 + js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, UndefinedValue());
1.85 + XPCWrappedNativeScope* scope = xpc::MaybeGetObjectScope(obj);
1.86 + if (scope) {
1.87 + scope->RemoveDOMExpandoObject(obj);
1.88 + }
1.89 + } else {
1.90 + js::ExpandoAndGeneration* expandoAndGeneration =
1.91 + static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
1.92 + v = expandoAndGeneration->expando;
1.93 + if (v.isUndefined()) {
1.94 + return nullptr;
1.95 + }
1.96 + expandoAndGeneration->expando = UndefinedValue();
1.97 + }
1.98 +
1.99 +
1.100 + return &v.toObject();
1.101 +}
1.102 +
1.103 +// static
1.104 +JSObject*
1.105 +DOMProxyHandler::EnsureExpandoObject(JSContext* cx, JS::Handle<JSObject*> obj)
1.106 +{
1.107 + NS_ASSERTION(IsDOMProxy(obj), "expected a DOM proxy object");
1.108 + JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
1.109 + if (v.isObject()) {
1.110 + return &v.toObject();
1.111 + }
1.112 +
1.113 + js::ExpandoAndGeneration* expandoAndGeneration;
1.114 + if (!v.isUndefined()) {
1.115 + expandoAndGeneration = static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
1.116 + if (expandoAndGeneration->expando.isObject()) {
1.117 + return &expandoAndGeneration->expando.toObject();
1.118 + }
1.119 + } else {
1.120 + expandoAndGeneration = nullptr;
1.121 + }
1.122 +
1.123 + JS::Rooted<JSObject*> parent(cx, js::GetObjectParent(obj));
1.124 + JS::Rooted<JSObject*> expando(cx,
1.125 + JS_NewObjectWithGivenProto(cx, nullptr, JS::NullPtr(), parent));
1.126 + if (!expando) {
1.127 + return nullptr;
1.128 + }
1.129 +
1.130 + nsISupports* native = UnwrapDOMObject<nsISupports>(obj);
1.131 + nsWrapperCache* cache;
1.132 + CallQueryInterface(native, &cache);
1.133 + if (expandoAndGeneration) {
1.134 + cache->PreserveWrapper(native);
1.135 + expandoAndGeneration->expando.setObject(*expando);
1.136 +
1.137 + return expando;
1.138 + }
1.139 +
1.140 + XPCWrappedNativeScope* scope = xpc::GetObjectScope(obj);
1.141 + if (!scope->RegisterDOMExpandoObject(obj)) {
1.142 + return nullptr;
1.143 + }
1.144 +
1.145 + cache->SetPreservingWrapper(true);
1.146 + js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, ObjectValue(*expando));
1.147 +
1.148 + return expando;
1.149 +}
1.150 +
1.151 +bool
1.152 +DOMProxyHandler::isExtensible(JSContext *cx, JS::Handle<JSObject*> proxy, bool *extensible)
1.153 +{
1.154 + // always extensible per WebIDL
1.155 + *extensible = true;
1.156 + return true;
1.157 +}
1.158 +
1.159 +bool
1.160 +DOMProxyHandler::preventExtensions(JSContext *cx, JS::Handle<JSObject*> proxy)
1.161 +{
1.162 + // Throw a TypeError, per WebIDL.
1.163 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr,
1.164 + JSMSG_CANT_CHANGE_EXTENSIBILITY);
1.165 + return false;
1.166 +}
1.167 +
1.168 +bool
1.169 +BaseDOMProxyHandler::getPropertyDescriptor(JSContext* cx,
1.170 + JS::Handle<JSObject*> proxy,
1.171 + JS::Handle<jsid> id,
1.172 + MutableHandle<JSPropertyDescriptor> desc)
1.173 +{
1.174 + if (!getOwnPropertyDescriptor(cx, proxy, id, desc)) {
1.175 + return false;
1.176 + }
1.177 + if (desc.object()) {
1.178 + return true;
1.179 + }
1.180 +
1.181 + JS::Rooted<JSObject*> proto(cx);
1.182 + if (!js::GetObjectProto(cx, proxy, &proto)) {
1.183 + return false;
1.184 + }
1.185 + if (!proto) {
1.186 + desc.object().set(nullptr);
1.187 + return true;
1.188 + }
1.189 +
1.190 + return JS_GetPropertyDescriptorById(cx, proto, id, desc);
1.191 +}
1.192 +
1.193 +bool
1.194 +BaseDOMProxyHandler::getOwnPropertyDescriptor(JSContext* cx,
1.195 + JS::Handle<JSObject*> proxy,
1.196 + JS::Handle<jsid> id,
1.197 + MutableHandle<JSPropertyDescriptor> desc)
1.198 +{
1.199 + return getOwnPropDescriptor(cx, proxy, id, /* ignoreNamedProps = */ false,
1.200 + desc);
1.201 +}
1.202 +
1.203 +bool
1.204 +DOMProxyHandler::defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.205 + MutableHandle<JSPropertyDescriptor> desc, bool* defined)
1.206 +{
1.207 + if (desc.hasGetterObject() && desc.setter() == JS_StrictPropertyStub) {
1.208 + return JS_ReportErrorFlagsAndNumber(cx,
1.209 + JSREPORT_WARNING | JSREPORT_STRICT |
1.210 + JSREPORT_STRICT_MODE_ERROR,
1.211 + js_GetErrorMessage, nullptr,
1.212 + JSMSG_GETTER_ONLY);
1.213 + }
1.214 +
1.215 + if (xpc::WrapperFactory::IsXrayWrapper(proxy)) {
1.216 + return true;
1.217 + }
1.218 +
1.219 + JSObject* expando = EnsureExpandoObject(cx, proxy);
1.220 + if (!expando) {
1.221 + return false;
1.222 + }
1.223 +
1.224 + bool dummy;
1.225 + return js_DefineOwnProperty(cx, expando, id, desc, &dummy);
1.226 +}
1.227 +
1.228 +bool
1.229 +DOMProxyHandler::set(JSContext *cx, Handle<JSObject*> proxy, Handle<JSObject*> receiver,
1.230 + Handle<jsid> id, bool strict, MutableHandle<JS::Value> vp)
1.231 +{
1.232 + MOZ_ASSERT(!xpc::WrapperFactory::IsXrayWrapper(proxy),
1.233 + "Should not have a XrayWrapper here");
1.234 + bool done;
1.235 + if (!setCustom(cx, proxy, id, vp, &done)) {
1.236 + return false;
1.237 + }
1.238 + if (done) {
1.239 + return true;
1.240 + }
1.241 +
1.242 + // Make sure to ignore our named properties when checking for own
1.243 + // property descriptors for a set.
1.244 + JS::Rooted<JSPropertyDescriptor> desc(cx);
1.245 + if (!getOwnPropDescriptor(cx, proxy, id, /* ignoreNamedProps = */ true,
1.246 + &desc)) {
1.247 + return false;
1.248 + }
1.249 + bool descIsOwn = desc.object() != nullptr;
1.250 + if (!desc.object()) {
1.251 + // Don't just use getPropertyDescriptor, unlike BaseProxyHandler::set,
1.252 + // because that would call getOwnPropertyDescriptor on ourselves. Instead,
1.253 + // directly delegate to the proto, if any.
1.254 + JS::Rooted<JSObject*> proto(cx);
1.255 + if (!js::GetObjectProto(cx, proxy, &proto)) {
1.256 + return false;
1.257 + }
1.258 + if (proto && !JS_GetPropertyDescriptorById(cx, proto, id, &desc)) {
1.259 + return false;
1.260 + }
1.261 + }
1.262 +
1.263 + return js::SetPropertyIgnoringNamedGetter(cx, this, proxy, receiver, id,
1.264 + &desc, descIsOwn, strict, vp);
1.265 +}
1.266 +
1.267 +bool
1.268 +DOMProxyHandler::delete_(JSContext* cx, JS::Handle<JSObject*> proxy,
1.269 + JS::Handle<jsid> id, bool* bp)
1.270 +{
1.271 + JS::Rooted<JSObject*> expando(cx);
1.272 + if (!xpc::WrapperFactory::IsXrayWrapper(proxy) && (expando = GetExpandoObject(proxy))) {
1.273 + return JS_DeletePropertyById2(cx, expando, id, bp);
1.274 + }
1.275 +
1.276 + *bp = true;
1.277 + return true;
1.278 +}
1.279 +
1.280 +bool
1.281 +BaseDOMProxyHandler::enumerate(JSContext* cx, JS::Handle<JSObject*> proxy,
1.282 + AutoIdVector& props)
1.283 +{
1.284 + JS::Rooted<JSObject*> proto(cx);
1.285 + if (!JS_GetPrototype(cx, proxy, &proto)) {
1.286 + return false;
1.287 + }
1.288 + return keys(cx, proxy, props) &&
1.289 + (!proto || js::GetPropertyNames(cx, proto, 0, &props));
1.290 +}
1.291 +
1.292 +bool
1.293 +BaseDOMProxyHandler::watch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.294 + JS::Handle<JSObject*> callable)
1.295 +{
1.296 + return js::WatchGuts(cx, proxy, id, callable);
1.297 +}
1.298 +
1.299 +bool
1.300 +BaseDOMProxyHandler::unwatch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id)
1.301 +{
1.302 + return js::UnwatchGuts(cx, proxy, id);
1.303 +}
1.304 +
1.305 +bool
1.306 +BaseDOMProxyHandler::getOwnPropertyNames(JSContext* cx,
1.307 + JS::Handle<JSObject*> proxy,
1.308 + JS::AutoIdVector& props)
1.309 +{
1.310 + return ownPropNames(cx, proxy, JSITER_OWNONLY | JSITER_HIDDEN, props);
1.311 +}
1.312 +
1.313 +bool
1.314 +BaseDOMProxyHandler::keys(JSContext* cx,
1.315 + JS::Handle<JSObject*> proxy,
1.316 + JS::AutoIdVector& props)
1.317 +{
1.318 + return ownPropNames(cx, proxy, JSITER_OWNONLY, props);
1.319 +}
1.320 +
1.321 +bool
1.322 +DOMProxyHandler::has(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id, bool* bp)
1.323 +{
1.324 + if (!hasOwn(cx, proxy, id, bp)) {
1.325 + return false;
1.326 + }
1.327 +
1.328 + if (*bp) {
1.329 + // We have the property ourselves; no need to worry about our prototype
1.330 + // chain.
1.331 + return true;
1.332 + }
1.333 +
1.334 + // OK, now we have to look at the proto
1.335 + JS::Rooted<JSObject*> proto(cx);
1.336 + if (!js::GetObjectProto(cx, proxy, &proto)) {
1.337 + return false;
1.338 + }
1.339 + if (!proto) {
1.340 + return true;
1.341 + }
1.342 + bool protoHasProp;
1.343 + bool ok = JS_HasPropertyById(cx, proto, id, &protoHasProp);
1.344 + if (ok) {
1.345 + *bp = protoHasProp;
1.346 + }
1.347 + return ok;
1.348 +}
1.349 +
1.350 +int32_t
1.351 +IdToInt32(JSContext* cx, JS::Handle<jsid> id)
1.352 +{
1.353 + JS::Rooted<JS::Value> idval(cx);
1.354 + double array_index;
1.355 + int32_t i;
1.356 + if (!::JS_IdToValue(cx, id, &idval) ||
1.357 + !JS::ToNumber(cx, idval, &array_index) ||
1.358 + !::JS_DoubleIsInt32(array_index, &i)) {
1.359 + return -1;
1.360 + }
1.361 +
1.362 + return i;
1.363 +}
1.364 +
1.365 +bool
1.366 +DOMProxyHandler::setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.367 + JS::MutableHandle<JS::Value> vp, bool *done)
1.368 +{
1.369 + *done = false;
1.370 + return true;
1.371 +}
1.372 +
1.373 +} // namespace dom
1.374 +} // namespace mozilla
