gecko/dom/bindings/DOMJSProxyHandler.cpp
Jason Orendorff b0be187269 Bug 1142794 - Change 'receiver' argument to SetProperty functions and ProxyHandler::set methods to be a HandleValue. r=Waldo.
Also: Change signature of these functions and methods to all have the same arguments in the same order: (cx, obj, id, v, receiver). Also change v from MutableHandleValue to HandleValue.

There is no change in behavior.

In fact the new error message `JSMSG_SET_NON_OBJECT_RECEIVER` is
impossible to trigger from scripts for now, I think (after re-reading
the whole patch with this in mind). JS_ForwardSetPropertyTo is the only
way to get a non-object receiver into the engine, but no caller
currently does so.

We're installing new pipes here, and they should work, but for now it's
the same cold water flowing through as before. Actually hooking up the
hot water is left for another bug (one with tests, not to put too fine a
point on it).

Notes:

*   InvokeGetterOrSetter had to be split into two functions:
    InvokeGetter takes a MutableHandleValue out-param,
    InvokeSetter a HandleValue in-param.

*   Watchpoints can still tamper with values being assigned. So can
    JSSetterOps. I'm pleased we can support this craziness in a way that
    doesn't have to spread via the type system to encompass the entire
    codebase.

*   Change in GlobalObject::setIntrinsicValue is not really a change.
    Yes, it asserted before, but an exception thrown during self-hosting
    initialization is not going to go unnoticed either.

*   Since the receiver argument to js::SetProperty() is at the end now, it
    makes sense for it to be optional. Some callers look nicer.
2015-03-01 13:16:19 -06:00

382 lines
10 KiB
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=2 sw=2 et tw=99 ft=cpp: */
/* 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 "mozilla/dom/DOMJSProxyHandler.h"
#include "xpcpublic.h"
#include "xpcprivate.h"
#include "XPCWrapper.h"
#include "WrapperFactory.h"
#include "nsDOMClassInfo.h"
#include "nsWrapperCacheInlines.h"
#include "mozilla/dom/BindingUtils.h"
#include "jsapi.h"
using namespace JS;
namespace mozilla {
namespace dom {
jsid s_length_id = JSID_VOID;
bool
DefineStaticJSVals(JSContext* cx)
{
return InternJSString(cx, s_length_id, "length");
}
const char DOMProxyHandler::family = 0;
js::DOMProxyShadowsResult
DOMProxyShadows(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id)
{
JS::Rooted<JSObject*> expando(cx, DOMProxyHandler::GetExpandoObject(proxy));
JS::Value v = js::GetProxyExtra(proxy, JSPROXYSLOT_EXPANDO);
bool isOverrideBuiltins = !v.isObject() && !v.isUndefined();
if (expando) {
bool hasOwn;
if (!JS_AlreadyHasOwnPropertyById(cx, expando, id, &hasOwn))
return js::ShadowCheckFailed;
if (hasOwn) {
return isOverrideBuiltins ?
js::ShadowsViaIndirectExpando : js::ShadowsViaDirectExpando;
}
}
if (!isOverrideBuiltins) {
// Our expando, if any, didn't shadow, so we're not shadowing at all.
return js::DoesntShadow;
}
bool hasOwn;
if (!GetProxyHandler(proxy)->hasOwn(cx, proxy, id, &hasOwn))
return js::ShadowCheckFailed;
return hasOwn ? js::Shadows : js::DoesntShadowUnique;
}
// Store the information for the specialized ICs.
struct SetDOMProxyInformation
{
SetDOMProxyInformation() {
js::SetDOMProxyInformation((const void*) &DOMProxyHandler::family,
JSPROXYSLOT_EXPANDO, DOMProxyShadows);
}
};
SetDOMProxyInformation gSetDOMProxyInformation;
// static
JSObject*
DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isUndefined()) {
return nullptr;
}
if (v.isObject()) {
js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, UndefinedValue());
xpc::ObjectScope(obj)->RemoveDOMExpandoObject(obj);
} else {
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
if (v.isUndefined()) {
return nullptr;
}
expandoAndGeneration->expando = UndefinedValue();
}
return &v.toObject();
}
// static
JSObject*
DOMProxyHandler::EnsureExpandoObject(JSContext* cx, JS::Handle<JSObject*> obj)
{
NS_ASSERTION(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isObject()) {
return &v.toObject();
}
js::ExpandoAndGeneration* expandoAndGeneration;
if (!v.isUndefined()) {
expandoAndGeneration = static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
if (expandoAndGeneration->expando.isObject()) {
return &expandoAndGeneration->expando.toObject();
}
} else {
expandoAndGeneration = nullptr;
}
JS::Rooted<JSObject*> expando(cx,
JS_NewObjectWithGivenProto(cx, nullptr, JS::NullPtr()));
if (!expando) {
return nullptr;
}
nsISupports* native = UnwrapDOMObject<nsISupports>(obj);
nsWrapperCache* cache;
CallQueryInterface(native, &cache);
if (expandoAndGeneration) {
cache->PreserveWrapper(native);
expandoAndGeneration->expando.setObject(*expando);
return expando;
}
if (!xpc::ObjectScope(obj)->RegisterDOMExpandoObject(obj)) {
return nullptr;
}
cache->SetPreservingWrapper(true);
js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, ObjectValue(*expando));
return expando;
}
bool
DOMProxyHandler::preventExtensions(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::ObjectOpResult& result) const
{
// always extensible per WebIDL
return result.failCantPreventExtensions();
}
bool
DOMProxyHandler::isExtensible(JSContext *cx, JS::Handle<JSObject*> proxy, bool *extensible) const
{
*extensible = true;
return true;
}
bool
BaseDOMProxyHandler::getPropertyDescriptor(JSContext* cx,
JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id,
MutableHandle<JSPropertyDescriptor> desc) const
{
if (!getOwnPropertyDescriptor(cx, proxy, id, desc)) {
return false;
}
if (desc.object()) {
return true;
}
JS::Rooted<JSObject*> proto(cx);
if (!js::GetObjectProto(cx, proxy, &proto)) {
return false;
}
if (!proto) {
desc.object().set(nullptr);
return true;
}
return JS_GetPropertyDescriptorById(cx, proto, id, desc);
}
bool
BaseDOMProxyHandler::getOwnPropertyDescriptor(JSContext* cx,
JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id,
MutableHandle<JSPropertyDescriptor> desc) const
{
return getOwnPropDescriptor(cx, proxy, id, /* ignoreNamedProps = */ false,
desc);
}
bool
DOMProxyHandler::defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
Handle<JSPropertyDescriptor> desc,
JS::ObjectOpResult &result, bool *defined) const
{
if (desc.hasGetterObject() && desc.setter() == JS_StrictPropertyStub) {
return result.failGetterOnly();
}
if (xpc::WrapperFactory::IsXrayWrapper(proxy)) {
return result.succeed();
}
JSObject* expando = EnsureExpandoObject(cx, proxy);
if (!expando) {
return false;
}
if (!js::DefineOwnProperty(cx, expando, id, desc, result)) {
return false;
}
*defined = true;
return true;
}
bool
DOMProxyHandler::set(JSContext *cx, Handle<JSObject*> proxy, Handle<jsid> id,
Handle<JS::Value> v, Handle<JS::Value> receiver,
ObjectOpResult &result) const
{
MOZ_ASSERT(!xpc::WrapperFactory::IsXrayWrapper(proxy),
"Should not have a XrayWrapper here");
bool done;
if (!setCustom(cx, proxy, id, v, &done)) {
return false;
}
if (done) {
return result.succeed();
}
// Make sure to ignore our named properties when checking for own
// property descriptors for a set.
JS::Rooted<JSPropertyDescriptor> desc(cx);
if (!getOwnPropDescriptor(cx, proxy, id, /* ignoreNamedProps = */ true,
&desc)) {
return false;
}
if (!desc.object()) {
// Don't just use getPropertyDescriptor, unlike BaseProxyHandler::set,
// because that would call getOwnPropertyDescriptor on ourselves. Instead,
// directly delegate to the proto, if any.
JS::Rooted<JSObject*> proto(cx);
if (!js::GetObjectProto(cx, proxy, &proto)) {
return false;
}
if (proto && !JS_GetPropertyDescriptorById(cx, proto, id, &desc)) {
return false;
}
}
return js::SetPropertyIgnoringNamedGetter(cx, proxy, id, v, receiver, desc, result);
}
bool
DOMProxyHandler::delete_(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id, JS::ObjectOpResult &result) const
{
JS::Rooted<JSObject*> expando(cx);
if (!xpc::WrapperFactory::IsXrayWrapper(proxy) && (expando = GetExpandoObject(proxy))) {
return JS_DeletePropertyById(cx, expando, id, result);
}
return result.succeed();
}
bool
BaseDOMProxyHandler::watch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::Handle<JSObject*> callable) const
{
return js::WatchGuts(cx, proxy, id, callable);
}
bool
BaseDOMProxyHandler::unwatch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id) const
{
return js::UnwatchGuts(cx, proxy, id);
}
bool
BaseDOMProxyHandler::ownPropertyKeys(JSContext* cx,
JS::Handle<JSObject*> proxy,
JS::AutoIdVector& props) const
{
return ownPropNames(cx, proxy, JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS, props);
}
bool
BaseDOMProxyHandler::getOwnEnumerablePropertyKeys(JSContext* cx,
JS::Handle<JSObject*> proxy,
JS::AutoIdVector& props) const
{
return ownPropNames(cx, proxy, JSITER_OWNONLY, props);
}
bool
BaseDOMProxyHandler::enumerate(JSContext *cx, JS::Handle<JSObject*> proxy,
JS::MutableHandle<JSObject*> objp) const
{
return BaseProxyHandler::enumerate(cx, proxy, objp);
}
bool
DOMProxyHandler::has(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id, bool* bp) const
{
if (!hasOwn(cx, proxy, id, bp)) {
return false;
}
if (*bp) {
// We have the property ourselves; no need to worry about our prototype
// chain.
return true;
}
// OK, now we have to look at the proto
JS::Rooted<JSObject*> proto(cx);
if (!js::GetObjectProto(cx, proxy, &proto)) {
return false;
}
if (!proto) {
return true;
}
bool protoHasProp;
bool ok = JS_HasPropertyById(cx, proto, id, &protoHasProp);
if (ok) {
*bp = protoHasProp;
}
return ok;
}
int32_t
IdToInt32(JSContext* cx, JS::Handle<jsid> id)
{
JS::Rooted<JS::Value> idval(cx);
double array_index;
int32_t i;
if (JSID_IS_SYMBOL(id) ||
!::JS_IdToValue(cx, id, &idval) ||
!JS::ToNumber(cx, idval, &array_index) ||
!::JS_DoubleIsInt32(array_index, &i)) {
return -1;
}
return i;
}
bool
DOMProxyHandler::setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::Handle<JS::Value> v, bool *done) const
{
*done = false;
return true;
}
//static
JSObject *
DOMProxyHandler::GetExpandoObject(JSObject *obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isObject()) {
return &v.toObject();
}
if (v.isUndefined()) {
return nullptr;
}
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
return v.isUndefined() ? nullptr : &v.toObject();
}
} // namespace dom
} // namespace mozilla