1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/widget/android/NativeJSContainer.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,567 @@
1.4 +/* -*- Mode: c++; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "NativeJSContainer.h"
1.10 +#include "AndroidBridge.h"
1.11 +#include "mozilla/Vector.h"
1.12 +#include "prthread.h"
1.13 +
1.14 +using namespace mozilla;
1.15 +using namespace mozilla::widget;
1.16 +
1.17 +namespace mozilla {
1.18 +namespace widget {
1.19 +
1.20 +class NativeJSContainer
1.21 +{
1.22 +public:
1.23 + static void InitJNI(JNIEnv* env) {
1.24 + if (jNativeJSContainer) {
1.25 + return;
1.26 + }
1.27 + jNativeJSContainer = AndroidBridge::GetClassGlobalRef(
1.28 + env, "org/mozilla/gecko/util/NativeJSContainer");
1.29 + MOZ_ASSERT(jNativeJSContainer);
1.30 + jContainerNativeObject = AndroidBridge::GetFieldID(
1.31 + env, jNativeJSContainer, "mNativeObject", "J");
1.32 + MOZ_ASSERT(jContainerNativeObject);
1.33 + jContainerConstructor = AndroidBridge::GetMethodID(
1.34 + env, jNativeJSContainer, "<init>", "(J)V");
1.35 + MOZ_ASSERT(jContainerConstructor);
1.36 +
1.37 + jNativeJSObject = AndroidBridge::GetClassGlobalRef(
1.38 + env, "org/mozilla/gecko/util/NativeJSObject");
1.39 + MOZ_ASSERT(jNativeJSObject);
1.40 + jObjectContainer = AndroidBridge::GetFieldID(
1.41 + env, jNativeJSObject, "mContainer",
1.42 + "Lorg/mozilla/gecko/util/NativeJSContainer;");
1.43 + MOZ_ASSERT(jObjectContainer);
1.44 + jObjectIndex = AndroidBridge::GetFieldID(
1.45 + env, jNativeJSObject, "mObjectIndex", "I");
1.46 + MOZ_ASSERT(jObjectIndex);
1.47 + jObjectConstructor = AndroidBridge::GetMethodID(
1.48 + env, jNativeJSObject, "<init>",
1.49 + "(Lorg/mozilla/gecko/util/NativeJSContainer;I)V");
1.50 + MOZ_ASSERT(jContainerConstructor);
1.51 + }
1.52 +
1.53 + static jobject CreateInstance(JNIEnv* env, JSContext* cx,
1.54 + JS::HandleObject object) {
1.55 + return CreateInstance(env, new NativeJSContainer(cx, object));
1.56 + }
1.57 +
1.58 + static NativeJSContainer* FromInstance(JNIEnv* env, jobject instance) {
1.59 + MOZ_ASSERT(instance);
1.60 +
1.61 + const jlong fieldValue =
1.62 + env->GetLongField(instance, jContainerNativeObject);
1.63 + NativeJSContainer* const nativeObject =
1.64 + reinterpret_cast<NativeJSContainer* const>(
1.65 + static_cast<uintptr_t>(fieldValue));
1.66 + if (!nativeObject) {
1.67 + AndroidBridge::ThrowException(env,
1.68 + "java/lang/NullPointerException",
1.69 + "Uninitialized NativeJSContainer");
1.70 + }
1.71 + return nativeObject;
1.72 + }
1.73 +
1.74 + static void DisposeInstance(JNIEnv* env, jobject instance) {
1.75 + NativeJSContainer* const container = FromInstance(env, instance);
1.76 + if (container) {
1.77 + env->SetLongField(instance, jContainerNativeObject,
1.78 + static_cast<jlong>(reinterpret_cast<uintptr_t>(nullptr)));
1.79 + delete container;
1.80 + }
1.81 + }
1.82 +
1.83 + static jobject CloneInstance(JNIEnv* env, jobject instance) {
1.84 + NativeJSContainer* const container = FromInstance(env, instance);
1.85 + if (!container || !container->EnsureObject(env)) {
1.86 + return nullptr;
1.87 + }
1.88 + JSContext* const cx = container->mThreadContext;
1.89 + JS::RootedObject object(cx, container->mJSObject);
1.90 + MOZ_ASSERT(object);
1.91 +
1.92 + JSAutoStructuredCloneBuffer buffer;
1.93 + if (!buffer.write(cx, JS::RootedValue(cx, JS::ObjectValue(*object)))) {
1.94 + AndroidBridge::ThrowException(env,
1.95 + "java/lang/UnsupportedOperationException",
1.96 + "Cannot serialize object");
1.97 + return nullptr;
1.98 + }
1.99 + return CreateInstance(env, new NativeJSContainer(cx, Move(buffer)));
1.100 + }
1.101 +
1.102 + static jobject GetInstanceFromObject(JNIEnv* env, jobject object) {
1.103 + MOZ_ASSERT(object);
1.104 +
1.105 + const jobject instance = env->GetObjectField(object, jObjectContainer);
1.106 + MOZ_ASSERT(instance);
1.107 + return instance;
1.108 + }
1.109 +
1.110 + static JSContext* GetContextFromObject(JNIEnv* env, jobject object) {
1.111 + MOZ_ASSERT(object);
1.112 + AutoLocalJNIFrame frame(env, 1);
1.113 +
1.114 + NativeJSContainer* const container =
1.115 + FromInstance(env, GetInstanceFromObject(env, object));
1.116 + if (!container) {
1.117 + return nullptr;
1.118 + }
1.119 + return container->mThreadContext;
1.120 + }
1.121 +
1.122 + static JSObject* GetObjectFromObject(JNIEnv* env, jobject object) {
1.123 + MOZ_ASSERT(object);
1.124 + AutoLocalJNIFrame frame(env, 1);
1.125 +
1.126 + NativeJSContainer* const container =
1.127 + FromInstance(env, GetInstanceFromObject(env, object));
1.128 + if (!container ||
1.129 + !container->EnsureObject(env)) { // Do thread check
1.130 + return nullptr;
1.131 + }
1.132 + const jint index = env->GetIntField(object, jObjectIndex);
1.133 + if (index < 0) {
1.134 + // -1 for index field means it's the root object of the container
1.135 + return container->mJSObject;
1.136 + }
1.137 + return container->mRootedObjects[index];
1.138 + }
1.139 +
1.140 + static jobject CreateObjectInstance(JNIEnv* env, jobject object,
1.141 + JS::HandleObject jsObject) {
1.142 + MOZ_ASSERT(object);
1.143 + MOZ_ASSERT(jsObject);
1.144 + AutoLocalJNIFrame frame(env, 2);
1.145 +
1.146 + jobject instance = GetInstanceFromObject(env, object);
1.147 + NativeJSContainer* const container = FromInstance(env, instance);
1.148 + if (!container) {
1.149 + return nullptr;
1.150 + }
1.151 + size_t newIndex = container->mRootedObjects.length();
1.152 + if (!container->mRootedObjects.append(jsObject)) {
1.153 + AndroidBridge::ThrowException(env,
1.154 + "java/lang/OutOfMemoryError", "Cannot allocate object");
1.155 + return nullptr;
1.156 + }
1.157 + const jobject newObject =
1.158 + env->NewObject(jNativeJSObject, jObjectConstructor,
1.159 + instance, newIndex);
1.160 + AndroidBridge::HandleUncaughtException(env);
1.161 + MOZ_ASSERT(newObject);
1.162 + return frame.Pop(newObject);
1.163 + }
1.164 +
1.165 + // Make sure we have a JSObject and deserialize if necessary/possible
1.166 + bool EnsureObject(JNIEnv* env) {
1.167 + if (mJSObject) {
1.168 + if (PR_GetCurrentThread() != mThread) {
1.169 + AndroidBridge::ThrowException(env,
1.170 + "java/lang/IllegalThreadStateException",
1.171 + "Using NativeJSObject off its thread");
1.172 + return false;
1.173 + }
1.174 + return true;
1.175 + }
1.176 + if (!SwitchContextToCurrentThread()) {
1.177 + AndroidBridge::ThrowException(env,
1.178 + "java/lang/IllegalThreadStateException",
1.179 + "Not available for this thread");
1.180 + return false;
1.181 + }
1.182 +
1.183 + JS::RootedValue value(mThreadContext);
1.184 + MOZ_ASSERT(mBuffer.data());
1.185 + MOZ_ALWAYS_TRUE(mBuffer.read(mThreadContext, &value));
1.186 + if (value.isObject()) {
1.187 + mJSObject = &value.toObject();
1.188 + }
1.189 + if (!mJSObject) {
1.190 + AndroidBridge::ThrowException(env,
1.191 + "java/lang/IllegalStateException", "Cannot deserialize data");
1.192 + return false;
1.193 + }
1.194 + mBuffer.clear();
1.195 + return true;
1.196 + }
1.197 +
1.198 +private:
1.199 + static jclass jNativeJSContainer;
1.200 + static jfieldID jContainerNativeObject;
1.201 + static jmethodID jContainerConstructor;
1.202 + static jclass jNativeJSObject;
1.203 + static jfieldID jObjectContainer;
1.204 + static jfieldID jObjectIndex;
1.205 + static jmethodID jObjectConstructor;
1.206 +
1.207 + static jobject CreateInstance(JNIEnv* env,
1.208 + NativeJSContainer* nativeObject) {
1.209 + InitJNI(env);
1.210 + const jobject newObject =
1.211 + env->NewObject(jNativeJSContainer, jContainerConstructor,
1.212 + static_cast<jlong>(
1.213 + reinterpret_cast<uintptr_t>(nativeObject)));
1.214 + AndroidBridge::HandleUncaughtException(env);
1.215 + MOZ_ASSERT(newObject);
1.216 + return newObject;
1.217 + }
1.218 +
1.219 + // Thread that the object is valid on
1.220 + PRThread* mThread;
1.221 + // Context that the object is valid in
1.222 + JSContext* mThreadContext;
1.223 + // Deserialized object, or nullptr if object is in serialized form
1.224 + JS::Heap<JSObject*> mJSObject;
1.225 + // Serialized object, or empty if object is in deserialized form
1.226 + JSAutoStructuredCloneBuffer mBuffer;
1.227 + // Objects derived from mJSObject
1.228 + Vector<JS::Heap<JSObject*>, 4> mRootedObjects;
1.229 +
1.230 + // Create a new container containing the given deserialized object
1.231 + NativeJSContainer(JSContext* cx, JS::HandleObject object)
1.232 + : mThread(PR_GetCurrentThread())
1.233 + , mThreadContext(cx)
1.234 + , mJSObject(object)
1.235 + {
1.236 + }
1.237 +
1.238 + // Create a new container containing the given serialized object
1.239 + NativeJSContainer(JSContext* cx, JSAutoStructuredCloneBuffer&& buffer)
1.240 + : mThread(PR_GetCurrentThread())
1.241 + , mThreadContext(cx)
1.242 + , mBuffer(Forward<JSAutoStructuredCloneBuffer>(buffer))
1.243 + {
1.244 + }
1.245 +
1.246 + bool SwitchContextToCurrentThread() {
1.247 + PRThread* const currentThread = PR_GetCurrentThread();
1.248 + if (currentThread == mThread) {
1.249 + return true;
1.250 + }
1.251 + return false;
1.252 + }
1.253 +};
1.254 +
1.255 +jclass NativeJSContainer::jNativeJSContainer = 0;
1.256 +jfieldID NativeJSContainer::jContainerNativeObject = 0;
1.257 +jmethodID NativeJSContainer::jContainerConstructor = 0;
1.258 +jclass NativeJSContainer::jNativeJSObject = 0;
1.259 +jfieldID NativeJSContainer::jObjectContainer = 0;
1.260 +jfieldID NativeJSContainer::jObjectIndex = 0;
1.261 +jmethodID NativeJSContainer::jObjectConstructor = 0;
1.262 +
1.263 +jobject
1.264 +CreateNativeJSContainer(JNIEnv* env, JSContext* cx, JS::HandleObject object)
1.265 +{
1.266 + return NativeJSContainer::CreateInstance(env, cx, object);
1.267 +}
1.268 +
1.269 +} // namespace widget
1.270 +} // namespace mozilla
1.271 +
1.272 +namespace {
1.273 +
1.274 +class JSJNIString
1.275 +{
1.276 +public:
1.277 + JSJNIString(JNIEnv* env, jstring str)
1.278 + : mEnv(env)
1.279 + , mJNIString(str)
1.280 + , mJSString(!str ? nullptr :
1.281 + reinterpret_cast<const jschar*>(env->GetStringChars(str, nullptr)))
1.282 + {
1.283 + }
1.284 + ~JSJNIString() {
1.285 + if (mJNIString) {
1.286 + mEnv->ReleaseStringChars(mJNIString,
1.287 + reinterpret_cast<const jchar*>(mJSString));
1.288 + }
1.289 + }
1.290 + operator const jschar*() const {
1.291 + return mJSString;
1.292 + }
1.293 + size_t Length() const {
1.294 + return static_cast<size_t>(mEnv->GetStringLength(mJNIString));
1.295 + }
1.296 +private:
1.297 + JNIEnv* const mEnv;
1.298 + const jstring mJNIString;
1.299 + const jschar* const mJSString;
1.300 +};
1.301 +
1.302 +bool
1.303 +CheckJSCall(JNIEnv* env, bool result) {
1.304 + if (!result) {
1.305 + AndroidBridge::ThrowException(env,
1.306 + "java/lang/UnsupportedOperationException", "JSAPI call failed");
1.307 + }
1.308 + return result;
1.309 +}
1.310 +
1.311 +bool
1.312 +CheckJNIArgument(JNIEnv* env, jobject arg) {
1.313 + if (!arg) {
1.314 + AndroidBridge::ThrowException(env,
1.315 + "java/lang/IllegalArgumentException", "Null argument");
1.316 + return false;
1.317 + }
1.318 + return true;
1.319 +}
1.320 +
1.321 +bool
1.322 +AppendJSON(const jschar* buf, uint32_t len, void* data)
1.323 +{
1.324 + static_cast<nsAutoString*>(data)->Append(buf, len);
1.325 + return true;
1.326 +}
1.327 +
1.328 +template <typename U, typename V,
1.329 + bool (JS::Value::*IsMethod)() const,
1.330 + V (JS::Value::*ToMethod)() const>
1.331 +struct PrimitiveProperty
1.332 +{
1.333 + typedef U Type; // JNI type
1.334 + typedef V NativeType; // JSAPI type
1.335 +
1.336 + static bool InValue(JS::HandleValue val) {
1.337 + return (static_cast<const JS::Value&>(val).*IsMethod)();
1.338 + }
1.339 +
1.340 + static Type FromValue(JNIEnv* env, jobject instance,
1.341 + JSContext* cx, JS::HandleValue val) {
1.342 + return static_cast<Type>(
1.343 + (static_cast<const JS::Value&>(val).*ToMethod)());
1.344 + }
1.345 +};
1.346 +
1.347 +// Statically cast from bool to jboolean (unsigned char); it works
1.348 +// since false and JNI_FALSE have the same value (0), and true and
1.349 +// JNI_TRUE have the same value (1).
1.350 +typedef PrimitiveProperty<jboolean, bool,
1.351 + &JS::Value::isBoolean, &JS::Value::toBoolean> BooleanProperty;
1.352 +
1.353 +typedef PrimitiveProperty<jdouble, double,
1.354 + &JS::Value::isNumber, &JS::Value::toNumber> DoubleProperty;
1.355 +
1.356 +typedef PrimitiveProperty<jint, int32_t,
1.357 + &JS::Value::isInt32, &JS::Value::toInt32> IntProperty;
1.358 +
1.359 +struct StringProperty
1.360 +{
1.361 + typedef jstring Type;
1.362 +
1.363 + static bool InValue(JS::HandleValue val) {
1.364 + return val.isString();
1.365 + }
1.366 +
1.367 + static Type FromValue(JNIEnv* env, jobject instance,
1.368 + JSContext* cx, JS::HandleValue val) {
1.369 + JS::RootedString str(cx, val.toString());
1.370 + size_t strLen = 0;
1.371 + const jschar* const strChars =
1.372 + JS_GetStringCharsAndLength(cx, str, &strLen);
1.373 + if (!CheckJSCall(env, !!strChars)) {
1.374 + return nullptr;
1.375 + }
1.376 + jstring ret = env->NewString(
1.377 + reinterpret_cast<const jchar*>(strChars), strLen);
1.378 + AndroidBridge::HandleUncaughtException(env);
1.379 + MOZ_ASSERT(ret);
1.380 + return ret;
1.381 + }
1.382 +};
1.383 +
1.384 +struct ObjectProperty
1.385 +{
1.386 + typedef jobject Type;
1.387 +
1.388 + static bool InValue(JS::HandleValue val) {
1.389 + return val.isObjectOrNull();
1.390 + }
1.391 +
1.392 + static Type FromValue(JNIEnv* env, jobject instance,
1.393 + JSContext* cx, JS::HandleValue val) {
1.394 + if (val.isNull()) {
1.395 + return nullptr;
1.396 + }
1.397 + JS::RootedObject object(cx, &val.toObject());
1.398 + return NativeJSContainer::CreateObjectInstance(env, instance, object);
1.399 + }
1.400 +};
1.401 +
1.402 +struct HasProperty
1.403 +{
1.404 + typedef jboolean Type;
1.405 +
1.406 + static bool InValue(JS::HandleValue val) {
1.407 + return true;
1.408 + }
1.409 +
1.410 + static Type FromValue(JNIEnv* env, jobject instance,
1.411 + JSContext* cx, JS::HandleValue val) {
1.412 + return JNI_TRUE;
1.413 + }
1.414 +};
1.415 +
1.416 +MOZ_BEGIN_ENUM_CLASS(FallbackOption)
1.417 + THROW,
1.418 + RETURN,
1.419 +MOZ_END_ENUM_CLASS(FallbackOption)
1.420 +
1.421 +template <class Property>
1.422 +typename Property::Type
1.423 +GetProperty(JNIEnv* env, jobject instance, jstring name,
1.424 + FallbackOption option = FallbackOption::THROW,
1.425 + typename Property::Type fallback = typename Property::Type()) {
1.426 + MOZ_ASSERT(env);
1.427 + MOZ_ASSERT(instance);
1.428 +
1.429 + JSContext* const cx =
1.430 + NativeJSContainer::GetContextFromObject(env, instance);
1.431 + const JS::RootedObject object(cx,
1.432 + NativeJSContainer::GetObjectFromObject(env, instance));
1.433 + const JSJNIString strName(env, name);
1.434 + JS::RootedValue val(cx);
1.435 +
1.436 + if (!object ||
1.437 + !CheckJNIArgument(env, name) ||
1.438 + !CheckJSCall(env,
1.439 + JS_GetUCProperty(cx, object, strName, strName.Length(), &val))) {
1.440 + return typename Property::Type();
1.441 + }
1.442 + if (val.isUndefined()) {
1.443 + if (option == FallbackOption::THROW) {
1.444 + AndroidBridge::ThrowException(env,
1.445 + "java/lang/IllegalArgumentException",
1.446 + "Property does not exist");
1.447 + }
1.448 + return fallback;
1.449 + }
1.450 + if (!Property::InValue(val)) {
1.451 + AndroidBridge::ThrowException(env,
1.452 + "java/lang/IllegalArgumentException",
1.453 + "Property type mismatch");
1.454 + return fallback;
1.455 + }
1.456 + return Property::FromValue(env, instance, cx, val);
1.457 +}
1.458 +
1.459 +} // namespace
1.460 +
1.461 +extern "C" {
1.462 +
1.463 +NS_EXPORT void JNICALL
1.464 +Java_org_mozilla_gecko_util_NativeJSContainer_dispose(JNIEnv* env, jobject instance)
1.465 +{
1.466 + MOZ_ASSERT(env);
1.467 + NativeJSContainer::DisposeInstance(env, instance);
1.468 +}
1.469 +
1.470 +NS_EXPORT jobject JNICALL
1.471 +Java_org_mozilla_gecko_util_NativeJSContainer_clone(JNIEnv* env, jobject instance)
1.472 +{
1.473 + MOZ_ASSERT(env);
1.474 + return NativeJSContainer::CloneInstance(env, instance);
1.475 +}
1.476 +
1.477 +NS_EXPORT jboolean JNICALL
1.478 +Java_org_mozilla_gecko_util_NativeJSObject_getBoolean(JNIEnv* env, jobject instance, jstring name)
1.479 +{
1.480 + return GetProperty<BooleanProperty>(env, instance, name);
1.481 +}
1.482 +
1.483 +NS_EXPORT jboolean JNICALL
1.484 +Java_org_mozilla_gecko_util_NativeJSObject_optBoolean(JNIEnv* env, jobject instance,
1.485 + jstring name, jboolean fallback)
1.486 +{
1.487 + return GetProperty<BooleanProperty>(env, instance, name, FallbackOption::RETURN, fallback);
1.488 +}
1.489 +
1.490 +NS_EXPORT jdouble JNICALL
1.491 +Java_org_mozilla_gecko_util_NativeJSObject_getDouble(JNIEnv* env, jobject instance, jstring name)
1.492 +{
1.493 + return GetProperty<DoubleProperty>(env, instance, name);
1.494 +}
1.495 +
1.496 +NS_EXPORT jdouble JNICALL
1.497 +Java_org_mozilla_gecko_util_NativeJSObject_optDouble(JNIEnv* env, jobject instance,
1.498 + jstring name, jdouble fallback)
1.499 +{
1.500 + return GetProperty<DoubleProperty>(env, instance, name, FallbackOption::RETURN, fallback);
1.501 +}
1.502 +
1.503 +NS_EXPORT jint JNICALL
1.504 +Java_org_mozilla_gecko_util_NativeJSObject_getInt(JNIEnv* env, jobject instance, jstring name)
1.505 +{
1.506 + return GetProperty<IntProperty>(env, instance, name);
1.507 +}
1.508 +
1.509 +NS_EXPORT jint JNICALL
1.510 +Java_org_mozilla_gecko_util_NativeJSObject_optInt(JNIEnv* env, jobject instance,
1.511 + jstring name, jint fallback)
1.512 +{
1.513 + return GetProperty<IntProperty>(env, instance, name, FallbackOption::RETURN, fallback);
1.514 +}
1.515 +
1.516 +NS_EXPORT jobject JNICALL
1.517 +Java_org_mozilla_gecko_util_NativeJSObject_getObject(JNIEnv* env, jobject instance, jstring name)
1.518 +{
1.519 + return GetProperty<ObjectProperty>(env, instance, name);
1.520 +}
1.521 +
1.522 +NS_EXPORT jobject JNICALL
1.523 +Java_org_mozilla_gecko_util_NativeJSObject_optObject(JNIEnv* env, jobject instance,
1.524 + jstring name, jobject fallback)
1.525 +{
1.526 + return GetProperty<ObjectProperty>(env, instance, name, FallbackOption::RETURN, fallback);
1.527 +}
1.528 +
1.529 +NS_EXPORT jstring JNICALL
1.530 +Java_org_mozilla_gecko_util_NativeJSObject_getString(JNIEnv* env, jobject instance, jstring name)
1.531 +{
1.532 + return GetProperty<StringProperty>(env, instance, name);
1.533 +}
1.534 +
1.535 +NS_EXPORT jstring JNICALL
1.536 +Java_org_mozilla_gecko_util_NativeJSObject_optString(JNIEnv* env, jobject instance,
1.537 + jstring name, jstring fallback)
1.538 +{
1.539 + return GetProperty<StringProperty>(env, instance, name, FallbackOption::RETURN, fallback);
1.540 +}
1.541 +
1.542 +NS_EXPORT jboolean JNICALL
1.543 +Java_org_mozilla_gecko_util_NativeJSObject_has(JNIEnv* env, jobject instance, jstring name)
1.544 +{
1.545 + return GetProperty<HasProperty>(env, instance, name, FallbackOption::RETURN, JNI_FALSE);
1.546 +}
1.547 +
1.548 +NS_EXPORT jstring JNICALL
1.549 +Java_org_mozilla_gecko_util_NativeJSObject_toString(JNIEnv* env, jobject instance)
1.550 +{
1.551 + MOZ_ASSERT(env);
1.552 + MOZ_ASSERT(instance);
1.553 +
1.554 + JSContext* const cx = NativeJSContainer::GetContextFromObject(env, instance);
1.555 + const JS::RootedObject object(cx, NativeJSContainer::GetObjectFromObject(env, instance));
1.556 + JS::RootedValue value(cx, JS::ObjectValue(*object));
1.557 + nsAutoString json;
1.558 +
1.559 + if (!object ||
1.560 + !CheckJSCall(env,
1.561 + JS_Stringify(cx, &value, JS::NullPtr(), JS::NullHandleValue, AppendJSON, &json))) {
1.562 + return nullptr;
1.563 + }
1.564 + jstring ret = env->NewString(reinterpret_cast<const jchar*>(json.get()), json.Length());
1.565 + AndroidBridge::HandleUncaughtException(env);
1.566 + MOZ_ASSERT(ret);
1.567 + return ret;
1.568 +}
1.569 +
1.570 +} // extern "C"
