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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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
#include "JSMEnvironmentProxy.h"
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/Maybe.h" // mozilla::Maybe
#include <stddef.h> // size_t
#include "jsapi.h" // JS_HasExtensibleLexicalEnvironment, JS_ExtensibleLexicalEnvironment
#include "js/Class.h" // JS::ObjectOpResult
#include "js/ErrorReport.h" // JS_ReportOutOfMemory
#include "js/GCVector.h" // JS::RootedVector
#include "js/Id.h" // JS::PropertyKey
#include "js/PropertyAndElement.h" // JS::IdVector, JS_HasPropertyById, JS_HasOwnPropertyById, JS_GetPropertyById, JS_Enumerate
#include "js/PropertyDescriptor.h" // JS::PropertyDescriptor, JS_GetOwnPropertyDescriptorById
#include "js/Proxy.h" // js::ProxyOptions, js::NewProxyObject, js::GetProxyPrivate
#include "js/RootingAPI.h" // JS::Rooted, JS::Handle, JS::MutableHandle
#include "js/TypeDecls.h" // JSContext, JSObject, JS::MutableHandleVector
#include "js/Value.h" // JS::Value, JS::UndefinedValue, JS_UNINITIALIZED_LEXICAL
#include "js/friend/ErrorMessages.h" // JSMSG_*
namespace mozilla {
namespace loader {
struct JSMEnvironmentProxyHandler : public js::BaseProxyHandler {
JSMEnvironmentProxyHandler() : BaseProxyHandler(&gFamily, false) {}
bool defineProperty(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::Handle<JS::PropertyDescriptor> aDesc,
JS::ObjectOpResult& aResult) const override {
return aResult.fail(JSMSG_CANT_DEFINE_PROP_OBJECT_NOT_EXTENSIBLE);
}
bool getPrototype(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandle<JSObject*> aProtop) const override {
aProtop.set(nullptr);
return true;
}
bool setPrototype(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JSObject*> aProto,
JS::ObjectOpResult& aResult) const override {
if (!aProto) {
return aResult.succeed();
}
return aResult.failCantSetProto();
}
bool getPrototypeIfOrdinary(
JSContext* aCx, JS::Handle<JSObject*> aProxy, bool* aIsOrdinary,
JS::MutableHandle<JSObject*> aProtop) const override {
*aIsOrdinary = false;
return true;
}
bool setImmutablePrototype(JSContext* aCx, JS::Handle<JSObject*> aProxy,
bool* aSucceeded) const override {
*aSucceeded = true;
return true;
}
bool preventExtensions(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::ObjectOpResult& aResult) const override {
aResult.succeed();
return true;
}
bool isExtensible(JSContext* aCx, JS::Handle<JSObject*> aProxy,
bool* aExtensible) const override {
*aExtensible = false;
return true;
}
bool set(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId, JS::Handle<JS::Value> aValue,
JS::Handle<JS::Value> aReceiver,
JS::ObjectOpResult& aResult) const override {
return aResult.failReadOnly();
}
bool delete_(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::ObjectOpResult& aResult) const override {
return aResult.failCantDelete();
}
bool getOwnPropertyDescriptor(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> aDesc)
const override;
bool has(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId, bool* aBp) const override;
bool get(JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::Value> aReceiver, JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<JS::Value> aVp) const override;
bool ownPropertyKeys(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandleVector<JS::PropertyKey> aProps) const override;
private:
static JSObject* getGlobal(JSContext* aCx, JS::Handle<JSObject*> aProxy) {
JS::Rooted<JSObject*> globalObj(aCx,
&js::GetProxyPrivate(aProxy).toObject());
return globalObj;
}
public:
static const char gFamily;
static const JSMEnvironmentProxyHandler gHandler;
};
const JSMEnvironmentProxyHandler JSMEnvironmentProxyHandler::gHandler;
const char JSMEnvironmentProxyHandler::gFamily = 0;
JSObject* ResolveModuleObjectPropertyById(JSContext* aCx,
JS::Handle<JSObject*> aModObj,
JS::Handle<JS::PropertyKey> aId) {
if (JS_HasExtensibleLexicalEnvironment(aModObj)) {
JS::Rooted<JSObject*> lexical(aCx,
JS_ExtensibleLexicalEnvironment(aModObj));
bool found;
if (!JS_HasOwnPropertyById(aCx, lexical, aId, &found)) {
return nullptr;
}
if (found) {
return lexical;
}
}
return aModObj;
}
JSObject* ResolveModuleObjectProperty(JSContext* aCx,
JS::Handle<JSObject*> aModObj,
const char* aName) {
if (JS_HasExtensibleLexicalEnvironment(aModObj)) {
JS::RootedObject lexical(aCx, JS_ExtensibleLexicalEnvironment(aModObj));
bool found;
if (!JS_HasOwnProperty(aCx, lexical, aName, &found)) {
return nullptr;
}
if (found) {
return lexical;
}
}
return aModObj;
}
bool JSMEnvironmentProxyHandler::getOwnPropertyDescriptor(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> aDesc) const {
JS::Rooted<JSObject*> globalObj(aCx, getGlobal(aCx, aProxy));
JS::Rooted<JSObject*> holder(
aCx, ResolveModuleObjectPropertyById(aCx, globalObj, aId));
if (!JS_GetOwnPropertyDescriptorById(aCx, holder, aId, aDesc)) {
return false;
}
if (aDesc.get().isNothing()) {
return true;
}
JS::PropertyDescriptor& desc = *aDesc.get();
if (desc.hasValue()) {
if (desc.value().isMagic(JS_UNINITIALIZED_LEXICAL)) {
desc.setValue(JS::UndefinedValue());
}
}
desc.setConfigurable(false);
desc.setEnumerable(true);
if (!desc.isAccessorDescriptor()) {
desc.setWritable(false);
}
return true;
}
bool JSMEnvironmentProxyHandler::has(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
bool* aBp) const {
JS::Rooted<JSObject*> globalObj(aCx, getGlobal(aCx, aProxy));
JS::Rooted<JSObject*> holder(
aCx, ResolveModuleObjectPropertyById(aCx, globalObj, aId));
return JS_HasPropertyById(aCx, holder, aId, aBp);
}
bool JSMEnvironmentProxyHandler::get(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::Value> aReceiver,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<JS::Value> aVp) const {
JS::Rooted<JSObject*> globalObj(aCx, getGlobal(aCx, aProxy));
JS::Rooted<JSObject*> holder(
aCx, ResolveModuleObjectPropertyById(aCx, globalObj, aId));
if (!JS_GetPropertyById(aCx, holder, aId, aVp)) {
return false;
}
if (aVp.isMagic(JS_UNINITIALIZED_LEXICAL)) {
aVp.setUndefined();
}
return true;
}
bool JSMEnvironmentProxyHandler::ownPropertyKeys(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandleVector<JS::PropertyKey> aProps) const {
JS::Rooted<JSObject*> globalObj(aCx, getGlobal(aCx, aProxy));
JS::Rooted<JS::IdVector> globalIds(aCx, JS::IdVector(aCx));
if (!JS_Enumerate(aCx, globalObj, &globalIds)) {
return false;
}
for (size_t i = 0; i < globalIds.length(); i++) {
if (!aProps.append(globalIds[i])) {
JS_ReportOutOfMemory(aCx);
return false;
}
}
JS::RootedObject lexicalEnv(aCx, JS_ExtensibleLexicalEnvironment(globalObj));
JS::Rooted<JS::IdVector> lexicalIds(aCx, JS::IdVector(aCx));
if (!JS_Enumerate(aCx, lexicalEnv, &lexicalIds)) {
return false;
}
for (size_t i = 0; i < lexicalIds.length(); i++) {
if (!aProps.append(lexicalIds[i])) {
JS_ReportOutOfMemory(aCx);
return false;
}
}
return true;
}
JSObject* CreateJSMEnvironmentProxy(JSContext* aCx,
JS::Handle<JSObject*> aGlobalObj) {
js::ProxyOptions options;
options.setLazyProto(true);
JS::Rooted<JS::Value> globalVal(aCx, JS::ObjectValue(*aGlobalObj));
return NewProxyObject(aCx, &JSMEnvironmentProxyHandler::gHandler, globalVal,
nullptr, options);
}
} // namespace loader
} // namespace mozilla