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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 "ModuleEnvironmentProxy.h"
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/Maybe.h" // mozilla::Maybe
#include <stddef.h> // size_t
#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_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
#include "js/friend/ErrorMessages.h" // JSMSG_*
#include "js/String.h"
#include "js/Modules.h"
namespace mozilla {
namespace loader {
struct ModuleEnvironmentProxyHandler : public js::BaseProxyHandler {
ModuleEnvironmentProxyHandler() : js::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> receiver, 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* getEnvironment(JS::Handle<JSObject*> aProxy) {
return &js::GetProxyPrivate(aProxy).toObject();
}
static bool equalsNamespace(JSContext* aCx, JS::Handle<JS::PropertyKey> aId,
bool* aMatch) {
if (!aId.isString()) {
*aMatch = false;
return true;
}
return JS_StringEqualsLiteral(aCx, aId.toString(), "*namespace*", aMatch);
}
public:
static const char gFamily;
static const ModuleEnvironmentProxyHandler gHandler;
};
const ModuleEnvironmentProxyHandler ModuleEnvironmentProxyHandler::gHandler;
const char ModuleEnvironmentProxyHandler::gFamily = 0;
bool ModuleEnvironmentProxyHandler::getOwnPropertyDescriptor(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> aDesc) const {
bool isNamespace;
if (!equalsNamespace(aCx, aId, &isNamespace)) {
return false;
}
if (isNamespace) {
aDesc.reset();
return true;
}
JS::Rooted<JSObject*> envObj(aCx, getEnvironment(aProxy));
if (!JS_GetOwnPropertyDescriptorById(aCx, envObj, aId, aDesc)) {
return false;
}
if (aDesc.get().isNothing()) {
return true;
}
JS::PropertyDescriptor& desc = *aDesc.get();
desc.setConfigurable(false);
desc.setWritable(false);
desc.setEnumerable(true);
return true;
}
bool ModuleEnvironmentProxyHandler::has(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
bool* aBp) const {
bool isNamespace;
if (!equalsNamespace(aCx, aId, &isNamespace)) {
return false;
}
if (isNamespace) {
*aBp = false;
return true;
}
JS::Rooted<JSObject*> envObj(aCx, getEnvironment(aProxy));
return JS_HasOwnPropertyById(aCx, envObj, aId, aBp);
}
bool ModuleEnvironmentProxyHandler::get(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::Value> aReceiver, JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<JS::Value> aVp) const {
bool isNamespace;
if (!equalsNamespace(aCx, aId, &isNamespace)) {
return false;
}
if (isNamespace) {
aVp.setUndefined();
return true;
}
JS::Rooted<JSObject*> envObj(aCx, getEnvironment(aProxy));
return JS_GetPropertyById(aCx, envObj, aId, aVp);
}
bool ModuleEnvironmentProxyHandler::ownPropertyKeys(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandleVector<JS::PropertyKey> aProps) const {
JS::Rooted<JSObject*> envObj(aCx, getEnvironment(aProxy));
JS::Rooted<JS::IdVector> ids(aCx, JS::IdVector(aCx));
if (!JS_Enumerate(aCx, envObj, &ids)) {
return false;
}
for (size_t i = 0; i < ids.length(); i++) {
bool isNamespace;
if (!equalsNamespace(aCx, ids[i], &isNamespace)) {
return false;
}
if (isNamespace) {
continue;
}
if (!aProps.append(ids[i])) {
JS_ReportOutOfMemory(aCx);
return false;
}
}
return true;
}
JSObject* CreateModuleEnvironmentProxy(JSContext* aCx,
JS::Handle<JSObject*> aModuleObj) {
js::ProxyOptions options;
options.setLazyProto(true);
JS::Rooted<JSObject*> envObj(aCx, JS::GetModuleEnvironment(aCx, aModuleObj));
if (!envObj) {
return nullptr;
}
JS::Rooted<JS::Value> envVal(aCx, JS::ObjectValue(*envObj));
return NewProxyObject(aCx, &ModuleEnvironmentProxyHandler::gHandler, envVal,
nullptr, options);
}
} // namespace loader
} // namespace mozilla