/******************************************************************************

* Experimental prototype for demonstrating VM agnostic and ABI stable API

* for native modules to use instead of using Nan and V8 APIs directly.

*

* The current status is "Experimental" and should not be used for

* production applications. The API is still subject to change

* and as an experimental feature is NOT subject to semver.

*

******************************************************************************/

#include <node_buffer.h>

#include <node_object_wrap.h>

#include <limits.h> // INT_MAX

#include <string.h>

#include <algorithm>

#include <cmath>

#include <vector>

#include "node_api.h"

#include "node_internals.h"

#include "env.h"

static

napi_status napi_set_last_error(napi_env env, napi_status error_code,

uint32_t engine_error_code = 0,

void* engine_reserved = nullptr);

static

napi_status napi_clear_last_error(napi_env env);

struct napi_env__ {

explicit napi_env__(v8::Isolate* _isolate, uv_loop_t* _loop)

: isolate(_isolate),

last_error(),

loop(_loop) {}

v8::Isolate* isolate;

node::Persistent<v8::Value> last_exception;

node::Persistent<v8::ObjectTemplate> wrap_template;

node::Persistent<v8::ObjectTemplate> function_data_template;

node::Persistent<v8::ObjectTemplate> accessor_data_template;

napi_extended_error_info last_error;

int open_handle_scopes = 0;

int open_callback_scopes = 0;

uv_loop_t* loop = nullptr;

};

#define NAPI_PRIVATE_KEY(context, suffix) \

(node::Environment::GetCurrent((context))->napi_ ## suffix())

#define ENV_OBJECT_TEMPLATE(env, prefix, destination, field_count) \

do { \

if ((env)->prefix ## _template.IsEmpty()) { \

(destination) = v8::ObjectTemplate::New(isolate); \

(destination)->SetInternalFieldCount((field_count)); \

(env)->prefix ## _template.Reset(isolate, (destination)); \

} else { \

(destination) = v8::Local<v8::ObjectTemplate>::New( \

isolate, env->prefix ## _template); \

} \

} while (0)

#define RETURN_STATUS_IF_FALSE(env, condition, status) \

do { \

if (!(condition)) { \

return napi_set_last_error((env), (status)); \

} \

} while (0)

#define CHECK_ENV(env) \

do { \

if ((env) == nullptr) { \

return napi_invalid_arg; \

} \

} while (0)

#define CHECK_ARG(env, arg) \

RETURN_STATUS_IF_FALSE((env), ((arg) != nullptr), napi_invalid_arg)

#define CHECK_MAYBE_EMPTY(env, maybe, status) \

RETURN_STATUS_IF_FALSE((env), !((maybe).IsEmpty()), (status))

#define CHECK_MAYBE_NOTHING(env, maybe, status) \

RETURN_STATUS_IF_FALSE((env), !((maybe).IsNothing()), (status))

// NAPI_PREAMBLE is not wrapped in do..while: try_catch must have function scope

#define NAPI_PREAMBLE(env) \

CHECK_ENV((env)); \

RETURN_STATUS_IF_FALSE((env), (env)->last_exception.IsEmpty(), \

napi_pending_exception); \

napi_clear_last_error((env)); \

v8impl::TryCatch try_catch((env))

#define CHECK_TO_TYPE(env, type, context, result, src, status) \

do { \

CHECK_ARG((env), (src)); \

auto maybe = v8impl::V8LocalValueFromJsValue((src))->To##type((context)); \

CHECK_MAYBE_EMPTY((env), maybe, (status)); \

(result) = maybe.ToLocalChecked(); \

} while (0)

#define CHECK_TO_FUNCTION(env, result, src) \

do { \

CHECK_ARG((env), (src)); \

v8::Local<v8::Value> v8value = v8impl::V8LocalValueFromJsValue((src)); \

RETURN_STATUS_IF_FALSE((env), v8value->IsFunction(), napi_invalid_arg); \

(result) = v8value.As<v8::Function>(); \

} while (0)

#define CHECK_TO_OBJECT(env, context, result, src) \

CHECK_TO_TYPE((env), Object, (context), (result), (src), napi_object_expected)

#define CHECK_TO_STRING(env, context, result, src) \

CHECK_TO_TYPE((env), String, (context), (result), (src), napi_string_expected)

#define CHECK_TO_NUMBER(env, context, result, src) \

CHECK_TO_TYPE((env), Number, (context), (result), (src), napi_number_expected)

#define CHECK_TO_BOOL(env, context, result, src) \

CHECK_TO_TYPE((env), Boolean, (context), (result), (src), \

napi_boolean_expected)

// n-api defines NAPI_AUTO_LENGHTH as the indicator that a string

// is null terminated. For V8 the equivalent is -1. The assert

// validates that our cast of NAPI_AUTO_LENGTH results in -1 as

// needed by V8.

#define CHECK_NEW_FROM_UTF8_LEN(env, result, str, len) \

do { \

static_assert(static_cast<int>(NAPI_AUTO_LENGTH) == -1, \

"Casting NAPI_AUTO_LENGTH to int must result in -1"); \

RETURN_STATUS_IF_FALSE((env), \

(len == NAPI_AUTO_LENGTH) || len <= INT_MAX, \

napi_invalid_arg); \

auto str_maybe = v8::String::NewFromUtf8( \

(env)->isolate, (str), v8::NewStringType::kInternalized, \

static_cast<int>(len)); \

CHECK_MAYBE_EMPTY((env), str_maybe, napi_generic_failure); \

(result) = str_maybe.ToLocalChecked(); \

} while (0)

#define CHECK_NEW_FROM_UTF8(env, result, str) \

CHECK_NEW_FROM_UTF8_LEN((env), (result), (str), NAPI_AUTO_LENGTH)

#define GET_RETURN_STATUS(env) \

(!try_catch.HasCaught() ? napi_ok \

: napi_set_last_error((env), napi_pending_exception))

#define THROW_RANGE_ERROR_IF_FALSE(env, condition, error, message) \

do { \

if (!(condition)) { \

napi_throw_range_error((env), (error), (message)); \

return napi_set_last_error((env), napi_generic_failure); \

} \

} while (0)

#define CREATE_TYPED_ARRAY( \

env, type, size_of_element, buffer, byte_offset, length, out) \

do { \

if ((size_of_element) > 1) { \

THROW_RANGE_ERROR_IF_FALSE( \

(env), (byte_offset) % (size_of_element) == 0, \

"ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT", \

"start offset of "#type" should be a multiple of "#size_of_element); \

} \

THROW_RANGE_ERROR_IF_FALSE((env), (length) * (size_of_element) + \

(byte_offset) <= buffer->ByteLength(), \

"ERR_NAPI_INVALID_TYPEDARRAY_LENGTH", \

"Invalid typed array length"); \

(out) = v8::type::New((buffer), (byte_offset), (length)); \

} while (0)

#define NAPI_CALL_INTO_MODULE(env, call, handle_exception) \

do { \

int open_handle_scopes = (env)->open_handle_scopes; \

int open_callback_scopes = (env)->open_callback_scopes; \

napi_clear_last_error((env)); \

call; \

CHECK_EQ((env)->open_handle_scopes, open_handle_scopes); \

CHECK_EQ((env)->open_callback_scopes, open_callback_scopes); \

if (!(env)->last_exception.IsEmpty()) { \

handle_exception( \

v8::Local<v8::Value>::New((env)->isolate, (env)->last_exception)); \

(env)->last_exception.Reset(); \

} \

} while (0)

#define NAPI_CALL_INTO_MODULE_THROW(env, call) \

NAPI_CALL_INTO_MODULE((env), call, (env)->isolate->ThrowException)

namespace {

namespace v8impl {

// convert from n-api property attributes to v8::PropertyAttribute

static inline v8::PropertyAttribute V8PropertyAttributesFromDescriptor(

const napi_property_descriptor* descriptor) {

unsigned int attribute_flags = v8::PropertyAttribute::None;

if (descriptor->getter != nullptr || descriptor->setter != nullptr) {

// The napi_writable attribute is ignored for accessor descriptors, but

// V8 requires the ReadOnly attribute to match nonexistence of a setter.

attribute_flags |= (descriptor->setter == nullptr ?

v8::PropertyAttribute::ReadOnly : v8::PropertyAttribute::None);

} else if ((descriptor->attributes & napi_writable) == 0) {

attribute_flags |= v8::PropertyAttribute::ReadOnly;

}

if ((descriptor->attributes & napi_enumerable) == 0) {

attribute_flags |= v8::PropertyAttribute::DontEnum;

}

if ((descriptor->attributes & napi_configurable) == 0) {

attribute_flags |= v8::PropertyAttribute::DontDelete;

}

return static_cast<v8::PropertyAttribute>(attribute_flags);

}

class HandleScopeWrapper {

public:

explicit HandleScopeWrapper(v8::Isolate* isolate) : scope(isolate) {}

private:

v8::HandleScope scope;

};

// In node v0.10 version of v8, there is no EscapableHandleScope and the

// node v0.10 port use HandleScope::Close(Local<T> v) to mimic the behavior

// of a EscapableHandleScope::Escape(Local<T> v), but it is not the same

// semantics. This is an example of where the api abstraction fail to work

// across different versions.

class EscapableHandleScopeWrapper {

public:

explicit EscapableHandleScopeWrapper(v8::Isolate* isolate)

: scope(isolate), escape_called_(false) {}

bool escape_called() const {

return escape_called_;

}

template <typename T>

v8::Local<T> Escape(v8::Local<T> handle) {

escape_called_ = true;

return scope.Escape(handle);

}

private:

v8::EscapableHandleScope scope;

bool escape_called_;

};

static

napi_handle_scope JsHandleScopeFromV8HandleScope(HandleScopeWrapper* s) {

return reinterpret_cast<napi_handle_scope>(s);

}

static

HandleScopeWrapper* V8HandleScopeFromJsHandleScope(napi_handle_scope s) {

return reinterpret_cast<HandleScopeWrapper*>(s);

}

static

napi_escapable_handle_scope JsEscapableHandleScopeFromV8EscapableHandleScope(

EscapableHandleScopeWrapper* s) {

return reinterpret_cast<napi_escapable_handle_scope>(s);

}

static

EscapableHandleScopeWrapper*

V8EscapableHandleScopeFromJsEscapableHandleScope(

napi_escapable_handle_scope s) {

return reinterpret_cast<EscapableHandleScopeWrapper*>(s);

}

static

napi_callback_scope JsCallbackScopeFromV8CallbackScope(

node::CallbackScope* s) {

return reinterpret_cast<napi_callback_scope>(s);

}

static

node::CallbackScope* V8CallbackScopeFromJsCallbackScope(

napi_callback_scope s) {

return reinterpret_cast<node::CallbackScope*>(s);

}

//=== Conversion between V8 Handles and napi_value ========================

// This asserts v8::Local<> will always be implemented with a single

// pointer field so that we can pass it around as a void*.

static_assert(sizeof(v8::Local<v8::Value>) == sizeof(napi_value),

"Cannot convert between v8::Local<v8::Value> and napi_value");

static

napi_deferred JsDeferredFromNodePersistent(node::Persistent<v8::Value>* local) {

return reinterpret_cast<napi_deferred>(local);

}

static

node::Persistent<v8::Value>* NodePersistentFromJsDeferred(napi_deferred local) {

return reinterpret_cast<node::Persistent<v8::Value>*>(local);

}

static

napi_value JsValueFromV8LocalValue(v8::Local<v8::Value> local) {

return reinterpret_cast<napi_value>(*local);

}

static

v8::Local<v8::Value> V8LocalValueFromJsValue(napi_value v) {

v8::Local<v8::Value> local;

memcpy(&local, &v, sizeof(v));

return local;

}

static inline void trigger_fatal_exception(

napi_env env, v8::Local<v8::Value> local_err) {

v8::Local<v8::Message> local_msg =

v8::Exception::CreateMessage(env->isolate, local_err);

node::FatalException(env->isolate, local_err, local_msg);

}

static inline napi_status V8NameFromPropertyDescriptor(napi_env env,

const napi_property_descriptor* p,

v8::Local<v8::Name>* result) {

if (p->utf8name != nullptr) {

CHECK_NEW_FROM_UTF8(env, *result, p->utf8name);

} else {

v8::Local<v8::Value> property_value =

v8impl::V8LocalValueFromJsValue(p->name);

RETURN_STATUS_IF_FALSE(env, property_value->IsName(), napi_name_expected);

*result = property_value.As<v8::Name>();

}

return napi_ok;

}

// Adapter for napi_finalize callbacks.

class Finalizer {

protected:

Finalizer(napi_env env,

napi_finalize finalize_callback,

void* finalize_data,

void* finalize_hint)

: _env(env),

_finalize_callback(finalize_callback),

_finalize_data(finalize_data),

_finalize_hint(finalize_hint) {

}

~Finalizer() {

}

public:

static Finalizer* New(napi_env env,

napi_finalize finalize_callback = nullptr,

void* finalize_data = nullptr,

void* finalize_hint = nullptr) {

return new Finalizer(

env, finalize_callback, finalize_data, finalize_hint);

}

static void Delete(Finalizer* finalizer) {

delete finalizer;

}

// node::Buffer::FreeCallback

static void FinalizeBufferCallback(char* data, void* hint) {

Finalizer* finalizer = static_cast<Finalizer*>(hint);

if (finalizer->_finalize_callback != nullptr) {

NAPI_CALL_INTO_MODULE_THROW(finalizer->_env,

finalizer->_finalize_callback(

finalizer->_env,

data,

finalizer->_finalize_hint));

}

Delete(finalizer);

}

protected:

napi_env _env;

napi_finalize _finalize_callback;

void* _finalize_data;

void* _finalize_hint;

};

// Wrapper around node::Persistent that implements reference counting.

class Reference : private Finalizer {

private:

Reference(napi_env env,

v8::Local<v8::Value> value,

uint32_t initial_refcount,

bool delete_self,

napi_finalize finalize_callback,

void* finalize_data,

void* finalize_hint)

: Finalizer(env, finalize_callback, finalize_data, finalize_hint),

_persistent(env->isolate, value),

_refcount(initial_refcount),

_delete_self(delete_self) {

if (initial_refcount == 0) {

_persistent.SetWeak(

this, FinalizeCallback, v8::WeakCallbackType::kParameter);

_persistent.MarkIndependent();

}

}

public:

void* Data() {

return _finalize_data;

}

static Reference* New(napi_env env,

v8::Local<v8::Value> value,

uint32_t initial_refcount,

bool delete_self,

napi_finalize finalize_callback = nullptr,

void* finalize_data = nullptr,

void* finalize_hint = nullptr) {

return new Reference(env,

value,

initial_refcount,

delete_self,

finalize_callback,

finalize_data,

finalize_hint);

}

static void Delete(Reference* reference) {

delete reference;

}

uint32_t Ref() {

if (++_refcount == 1) {

_persistent.ClearWeak();

}

return _refcount;

}

uint32_t Unref() {

if (_refcount == 0) {

return 0;

}

if (--_refcount == 0) {

_persistent.SetWeak(

this, FinalizeCallback, v8::WeakCallbackType::kParameter);

_persistent.MarkIndependent();

}

return _refcount;

}

uint32_t RefCount() {

return _refcount;

}

v8::Local<v8::Value> Get() {

if (_persistent.IsEmpty()) {

return v8::Local<v8::Value>();

} else {

return v8::Local<v8::Value>::New(_env->isolate, _persistent);

}

}

private:

static void FinalizeCallback(const v8::WeakCallbackInfo<Reference>& data) {

Reference* reference = data.GetParameter();

reference->_persistent.Reset();

// Check before calling the finalize callback, because the callback might

// delete it.

bool delete_self = reference->_delete_self;

napi_env env = reference->_env;

if (reference->_finalize_callback != nullptr) {

NAPI_CALL_INTO_MODULE_THROW(env,

reference->_finalize_callback(

reference->_env,

reference->_finalize_data,

reference->_finalize_hint));

}

if (delete_self) {

Delete(reference);

}

}

node::Persistent<v8::Value> _persistent;

uint32_t _refcount;

bool _delete_self;

};

class TryCatch : public v8::TryCatch {

public:

explicit TryCatch(napi_env env)

: v8::TryCatch(env->isolate), _env(env) {}

~TryCatch() {

if (HasCaught()) {

_env->last_exception.Reset(_env->isolate, Exception());

}

}

private:

napi_env _env;

};

//=== Function napi_callback wrapper =================================

static const int kDataIndex = 0;

static const int kEnvIndex = 1;

static const int kFunctionIndex = 2;

static const int kFunctionFieldCount = 3;

static const int kGetterIndex = 2;

static const int kSetterIndex = 3;

static const int kAccessorFieldCount = 4;

// Base class extended by classes that wrap V8 function and property callback

// info.

class CallbackWrapper {

public:

CallbackWrapper(napi_value this_arg, size_t args_length, void* data)

: _this(this_arg), _args_length(args_length), _data(data) {}

virtual napi_value GetNewTarget() = 0;

virtual void Args(napi_value* buffer, size_t bufferlength) = 0;

virtual void SetReturnValue(napi_value value) = 0;

napi_value This() { return _this; }

size_t ArgsLength() { return _args_length; }

void* Data() { return _data; }

protected:

const napi_value _this;

const size_t _args_length;

void* _data;

};

template <typename Info, int kInternalFieldIndex>

class CallbackWrapperBase : public CallbackWrapper {

public:

CallbackWrapperBase(const Info& cbinfo, const size_t args_length)

: CallbackWrapper(JsValueFromV8LocalValue(cbinfo.This()),

args_length,

nullptr),

_cbinfo(cbinfo),

_cbdata(v8::Local<v8::Object>::Cast(cbinfo.Data())) {

_data = v8::Local<v8::External>::Cast(_cbdata->GetInternalField(kDataIndex))

->Value();

}

napi_value GetNewTarget() override { return nullptr; }

protected:

void InvokeCallback() {

napi_callback_info cbinfo_wrapper = reinterpret_cast<napi_callback_info>(

static_cast<CallbackWrapper*>(this));

napi_callback cb = reinterpret_cast<napi_callback>(

v8::Local<v8::External>::Cast(

_cbdata->GetInternalField(kInternalFieldIndex))->Value());

napi_env env = static_cast<napi_env>(

v8::Local<v8::External>::Cast(

_cbdata->GetInternalField(kEnvIndex))->Value());

napi_value result;

NAPI_CALL_INTO_MODULE_THROW(env, result = cb(env, cbinfo_wrapper));

if (result != nullptr) {

this->SetReturnValue(result);

}

}

const Info& _cbinfo;

const v8::Local<v8::Object> _cbdata;

};

class FunctionCallbackWrapper

: public CallbackWrapperBase<v8::FunctionCallbackInfo<v8::Value>,

kFunctionIndex> {

public:

static void Invoke(const v8::FunctionCallbackInfo<v8::Value>& info) {

FunctionCallbackWrapper cbwrapper(info);

cbwrapper.InvokeCallback();

}

explicit FunctionCallbackWrapper(

const v8::FunctionCallbackInfo<v8::Value>& cbinfo)

: CallbackWrapperBase(cbinfo, cbinfo.Length()) {}

napi_value GetNewTarget() override {

if (_cbinfo.IsConstructCall()) {

return v8impl::JsValueFromV8LocalValue(_cbinfo.NewTarget());

} else {

return nullptr;

}

}

/*virtual*/

void Args(napi_value* buffer, size_t buffer_length) override {

size_t i = 0;

size_t min = std::min(buffer_length, _args_length);

for (; i < min; i += 1) {

buffer[i] = v8impl::JsValueFromV8LocalValue(_cbinfo[i]);

}

if (i < buffer_length) {

napi_value undefined =

v8impl::JsValueFromV8LocalValue(v8::Undefined(_cbinfo.GetIsolate()));

for (; i < buffer_length; i += 1) {

buffer[i] = undefined;

}

}

}

/*virtual*/

void SetReturnValue(napi_value value) override {

v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);

_cbinfo.GetReturnValue().Set(val);

}

};

class GetterCallbackWrapper

: public CallbackWrapperBase<v8::PropertyCallbackInfo<v8::Value>,

kGetterIndex> {

public:

static void Invoke(v8::Local<v8::Name> property,

const v8::PropertyCallbackInfo<v8::Value>& info) {

GetterCallbackWrapper cbwrapper(info);

cbwrapper.InvokeCallback();

}

explicit GetterCallbackWrapper(

const v8::PropertyCallbackInfo<v8::Value>& cbinfo)

: CallbackWrapperBase(cbinfo, 0) {}

/*virtual*/

void Args(napi_value* buffer, size_t buffer_length) override {

if (buffer_length > 0) {

napi_value undefined =

v8impl::JsValueFromV8LocalValue(v8::Undefined(_cbinfo.GetIsolate()));

for (size_t i = 0; i < buffer_length; i += 1) {

buffer[i] = undefined;

}

}

}

/*virtual*/

void SetReturnValue(napi_value value) override {

v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);

_cbinfo.GetReturnValue().Set(val);

}

};

class SetterCallbackWrapper

: public CallbackWrapperBase<v8::PropertyCallbackInfo<void>, kSetterIndex> {

public:

static void Invoke(v8::Local<v8::Name> property,

v8::Local<v8::Value> value,

const v8::PropertyCallbackInfo<void>& info) {

SetterCallbackWrapper cbwrapper(info, value);

cbwrapper.InvokeCallback();

}

SetterCallbackWrapper(const v8::PropertyCallbackInfo<void>& cbinfo,

const v8::Local<v8::Value>& value)

: CallbackWrapperBase(cbinfo, 1), _value(value) {}

/*virtual*/

void Args(napi_value* buffer, size_t buffer_length) override {

if (buffer_length > 0) {

buffer[0] = v8impl::JsValueFromV8LocalValue(_value);

if (buffer_length > 1) {

napi_value undefined = v8impl::JsValueFromV8LocalValue(

v8::Undefined(_cbinfo.GetIsolate()));

for (size_t i = 1; i < buffer_length; i += 1) {

buffer[i] = undefined;

}

}

}

}

/*virtual*/

void SetReturnValue(napi_value value) override {

// Ignore any value returned from a setter callback.

}

private:

const v8::Local<v8::Value>& _value;

};

// Creates an object to be made available to the static function callback

// wrapper, used to retrieve the native callback function and data pointer.

static

v8::Local<v8::Object> CreateFunctionCallbackData(napi_env env,

napi_callback cb,

void* data) {

v8::Isolate* isolate = env->isolate;

v8::Local<v8::Context> context = isolate->GetCurrentContext();

v8::Local<v8::ObjectTemplate> otpl;

ENV_OBJECT_TEMPLATE(env, function_data, otpl, v8impl::kFunctionFieldCount);

v8::Local<v8::Object> cbdata = otpl->NewInstance(context).ToLocalChecked();

cbdata->SetInternalField(

v8impl::kEnvIndex,

v8::External::New(isolate, static_cast<void*>(env)));

cbdata->SetInternalField(

v8impl::kFunctionIndex,

v8::External::New(isolate, reinterpret_cast<void*>(cb)));

cbdata->SetInternalField(

v8impl::kDataIndex,

v8::External::New(isolate, data));

return cbdata;

}

// Creates an object to be made available to the static getter/setter

// callback wrapper, used to retrieve the native getter/setter callback

// function and data pointer.

static

v8::Local<v8::Object> CreateAccessorCallbackData(napi_env env,

napi_callback getter,

napi_callback setter,

void* data) {

v8::Isolate* isolate = env->isolate;

v8::Local<v8::Context> context = isolate->GetCurrentContext();

v8::Local<v8::ObjectTemplate> otpl;

ENV_OBJECT_TEMPLATE(env, accessor_data, otpl, v8impl::kAccessorFieldCount);

v8::Local<v8::Object> cbdata = otpl->NewInstance(context).ToLocalChecked();

cbdata->SetInternalField(

v8impl::kEnvIndex,

v8::External::New(isolate, static_cast<void*>(env)));

if (getter != nullptr) {

cbdata->SetInternalField(

v8impl::kGetterIndex,

v8::External::New(isolate, reinterpret_cast<void*>(getter)));

}

if (setter != nullptr) {

cbdata->SetInternalField(

v8impl::kSetterIndex,

v8::External::New(isolate, reinterpret_cast<void*>(setter)));

}

cbdata->SetInternalField(

v8impl::kDataIndex,

v8::External::New(isolate, data));

return cbdata;

}

static void DeleteEnv(napi_env env, void* data, void* hint) {

delete env;

}

static

napi_env GetEnv(v8::Local<v8::Context> context) {

napi_env result;

auto isolate = context->GetIsolate();

auto global = context->Global();

// In the case of the string for which we grab the private and the value of

// the private on the global object we can call .ToLocalChecked() directly

// because we need to stop hard if either of them is empty.

//

// Re https://github.com/nodejs/node/pull/14217#discussion_r128775149

auto value = global->GetPrivate(context, NAPI_PRIVATE_KEY(context, env))

.ToLocalChecked();

if (value->IsExternal()) {

result = static_cast<napi_env>(value.As<v8::External>()->Value());

} else {

result = new napi_env__(isolate, node::GetCurrentEventLoop(isolate));

auto external = v8::External::New(isolate, result);

// We must also stop hard if the result of assigning the env to the global

// is either nothing or false.

CHECK(global->SetPrivate(context, NAPI_PRIVATE_KEY(context, env), external)

.FromJust());

// Create a self-destructing reference to external that will get rid of the

// napi_env when external goes out of scope.

Reference::New(result, external, 0, true, DeleteEnv, nullptr, nullptr);

}

return result;

}

enum UnwrapAction {

KeepWrap,

RemoveWrap

};

static

napi_status Unwrap(napi_env env,

napi_value js_object,

void** result,

UnwrapAction action) {

NAPI_PREAMBLE(env);

CHECK_ARG(env, js_object);

if (action == KeepWrap) {

CHECK_ARG(env, result);

}

v8::Isolate* isolate = env->isolate;

v8::Local<v8::Context> context = isolate->GetCurrentContext();

v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(js_object);

RETURN_STATUS_IF_FALSE(env, value->IsObject(), napi_invalid_arg);

v8::Local<v8::Object> obj = value.As<v8::Object>();

auto val = obj->GetPrivate(context, NAPI_PRIVATE_KEY(context, wrapper))

.ToLocalChecked();

RETURN_STATUS_IF_FALSE(env, val->IsExternal(), napi_invalid_arg);

Reference* reference =

static_cast<v8impl::Reference*>(val.As<v8::External>()->Value());

if (result) {

*result = reference->Data();

}

if (action == RemoveWrap) {

CHECK(obj->DeletePrivate(context, NAPI_PRIVATE_KEY(context, wrapper))

.FromJust());

Reference::Delete(reference);

}

return GET_RETURN_STATUS(env);

}

static

napi_status ConcludeDeferred(napi_env env,

napi_deferred deferred,

napi_value result,

bool is_resolved) {

NAPI_PREAMBLE(env);

CHECK_ARG(env, result);

v8::Local<v8::Context> context = env->isolate->GetCurrentContext();

node::Persistent<v8::Value>* deferred_ref =

NodePersistentFromJsDeferred(deferred);

v8::Local<v8::Value> v8_deferred =

v8::Local<v8::Value>::New(env->isolate, *deferred_ref);

auto v8_resolver = v8::Local<v8::Promise::Resolver>::Cast(v8_deferred);

v8::Maybe<bool> success = is_resolved ?

v8_resolver->Resolve(context, v8impl::V8LocalValueFromJsValue(result)) :

v8_resolver->Reject(context, v8impl::V8LocalValueFromJsValue(result));

delete deferred_ref;

RETURN_STATUS_IF_FALSE(env, success.FromMaybe(false), napi_generic_failure);

return GET_RETURN_STATUS(env);

}

} // end of namespace v8impl

// Intercepts the Node-V8 module registration callback. Converts parameters

// to NAPI equivalents and then calls the registration callback specified

// by the NAPI module.

void napi_module_register_cb(v8::Local<v8::Object> exports,

v8::Local<v8::Value> module,

v8::Local<v8::Context> context,

void* priv) {

napi_module* mod = static_cast<napi_module*>(priv);

// Create a new napi_env for this module or reference one if a pre-existing

// one is found.

napi_env env = v8impl::GetEnv(context);

napi_value _exports;

NAPI_CALL_INTO_MODULE_THROW(env,

_exports = mod->nm_register_func(env,

v8impl::JsValueFromV8LocalValue(exports)));

// If register function returned a non-null exports object different from

// the exports object we passed it, set that as the "exports" property of

// the module.

if (_exports != nullptr &&

_exports != v8impl::JsValueFromV8LocalValue(exports)) {

napi_value _module = v8impl::JsValueFromV8LocalValue(module);

napi_set_named_property(env, _module, "exports", _exports);

}

}

} // end of anonymous namespace

// Registers a NAPI module.

void napi_module_register(napi_module* mod) {

node::node_module* nm = new node::node_module {

-1,

mod->nm_flags,

nullptr,

mod->nm_filename,

nullptr,

napi_module_register_cb,

mod->nm_modname,

mod, // priv

nullptr,

};

node::node_module_register(nm);

}

// Warning: Keep in-sync with napi_status enum

static

const char* error_messages[] = {nullptr,

"Invalid argument",

"An object was expected",

"A string was expected",

"A string or symbol was expected",

"A function was expected",

"A number was expected",

"A boolean was expected",

"An array was expected",

"Unknown failure",

"An exception is pending",

"The async work item was cancelled",

"napi_escape_handle already called on scope",

"Invalid handle scope usage",

"Invalid callback scope usage"};

static inline napi_status napi_clear_last_error(napi_env env) {

env->last_error.error_code = napi_ok;

// TODO(boingoing): Should this be a callback?

env->last_error.engine_error_code = 0;

env->last_error.engine_reserved = nullptr;

return napi_ok;

}

static inline

napi_status napi_set_last_error(napi_env env, napi_status error_code,

uint32_t engine_error_code,

void* engine_reserved) {

env->last_error.error_code = error_code;

env->last_error.engine_error_code = engine_error_code;

env->last_error.engine_reserved = engine_reserved;

return error_code;

}

napi_status napi_get_last_error_info(napi_env env,

const napi_extended_error_info** result) {

CHECK_ENV(env);

CHECK_ARG(env, result);

// you must update this assert to reference the last message

// in the napi_status enum each time a new error message is added.

// We don't have a napi_status_last as this would result in an ABI

// change each time a message was added.

static_assert(

node::arraysize(error_messages) == napi_callback_scope_mismatch + 1,

"Count of error messages must match count of error values");

CHECK_LE(env->last_error.error_code, napi_callback_scope_mismatch);

// Wait until someone requests the last error information to fetch the error

// message string

env->last_error.error_message =

error_messages[env->last_error.error_code];

*result = &(env->last_error);

return napi_ok;

}

napi_status napi_fatal_exception(napi_env env, napi_value err) {

NAPI_PREAMBLE(env);

CHECK_ARG(env, err);

v8::Local<v8::Value> local_err = v8impl::V8LocalValueFromJsValue(err);

v8impl::trigger_fatal_exception(env, local_err);

return napi_clear_last_error(env);

}

NAPI_NO_RETURN void napi_fatal_error(const char* location,

size_t location_len,

const char* message,

size_t message_len) {

std::string location_string;

std::string message_string;

if (location_len != NAPI_AUTO_LENGTH) {

location_string.assign(

const_cast<char*>(location), location_len);

} else {

location_string.assign(

const_cast<char*>(location), strlen(location));

}

if (message_len != NAPI_AUTO_LENGTH) {

message_string.assign(

const_cast<char*>(message), message_len);

} else {