Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	api/callback.cc	Lines:	137	153	89.5 %
Date:	2021-09-21 04:13:38	Branches:	77	94	81.9 %


#include "node.h"
#include "async_wrap-inl.h"
#include "env-inl.h"
#include "v8.h"

namespace node {

using v8::Context;
using v8::EscapableHandleScope;
using v8::Function;
using v8::HandleScope;
using v8::Isolate;
using v8::Local;
using v8::MaybeLocal;
using v8::Object;
using v8::String;
using v8::Value;

CallbackScope::CallbackScope(Isolate* isolate,
                             Local<Object> object,
                             async_context async_context)
  : CallbackScope(Environment::GetCurrent(isolate), object, async_context) {}

CallbackScope::CallbackScope(Environment* env,
                             Local<Object> object,
                             async_context asyncContext)
  : private_(new InternalCallbackScope(env,
                                       object,
                                       asyncContext)),
    try_catch_(env->isolate()) {
  try_catch_.SetVerbose(true);
}

CallbackScope::~CallbackScope() {
  if (try_catch_.HasCaught())
    private_->MarkAsFailed();
  delete private_;
}

InternalCallbackScope::InternalCallbackScope(AsyncWrap* async_wrap, int flags)
    : InternalCallbackScope(async_wrap->env(),
                            async_wrap->object(),
                            { async_wrap->get_async_id(),
                              async_wrap->get_trigger_async_id() },
                            flags) {}

InternalCallbackScope::InternalCallbackScope(Environment* env,
                                             Local<Object> object,
                                             const async_context& asyncContext,
                                             int flags)
  : env_(env),
    async_context_(asyncContext),
    object_(object),
    skip_hooks_(flags & kSkipAsyncHooks),
    skip_task_queues_(flags & kSkipTaskQueues) {
  CHECK_NOT_NULL(env);
  env->PushAsyncCallbackScope();

  if (!env->can_call_into_js()) {
    failed_ = true;
    return;
  }

  Isolate* isolate = env->isolate();

  HandleScope handle_scope(isolate);
  // If you hit this assertion, you forgot to enter the v8::Context first.
  CHECK_EQ(Environment::GetCurrent(isolate), env);

  env->isolate()->SetIdle(false);

  env->async_hooks()->push_async_context(
    async_context_.async_id, async_context_.trigger_async_id, object);

  pushed_ids_ = true;

  if (asyncContext.async_id != 0 && !skip_hooks_) {
    // No need to check a return value because the application will exit if
    // an exception occurs.
    AsyncWrap::EmitBefore(env, asyncContext.async_id);
  }
}

InternalCallbackScope::~InternalCallbackScope() {
  Close();
  env_->PopAsyncCallbackScope();
}

void InternalCallbackScope::Close() {
  if (closed_) return;
  closed_ = true;

  Isolate* isolate = env_->isolate();
  auto idle = OnScopeLeave([&]() { isolate->SetIdle(true); });

  if (!env_->can_call_into_js()) return;
  auto perform_stopping_check = [&]() {
    if (env_->is_stopping()) {
      MarkAsFailed();
      env_->async_hooks()->clear_async_id_stack();
    }
  };
  perform_stopping_check();

  if (!failed_ && async_context_.async_id != 0 && !skip_hooks_) {
    AsyncWrap::EmitAfter(env_, async_context_.async_id);
  }

  if (pushed_ids_)
    env_->async_hooks()->pop_async_context(async_context_.async_id);

  if (failed_) return;

  if (env_->async_callback_scope_depth() > 1 || skip_task_queues_) {
    return;
  }

  TickInfo* tick_info = env_->tick_info();

  if (!env_->can_call_into_js()) return;

  auto weakref_cleanup = OnScopeLeave([&]() { env_->RunWeakRefCleanup(); });

  Local<Context> context = env_->context();
  if (!tick_info->has_tick_scheduled()) {
    context->GetMicrotaskQueue()->PerformCheckpoint(isolate);

    perform_stopping_check();
  }

  // Make sure the stack unwound properly. If there are nested MakeCallback's
  // then it should return early and not reach this code.
  if (env_->async_hooks()->fields()[AsyncHooks::kTotals]) {
    CHECK_EQ(env_->execution_async_id(), 0);
    CHECK_EQ(env_->trigger_async_id(), 0);
  }

  if (!tick_info->has_tick_scheduled() && !tick_info->has_rejection_to_warn()) {
    return;
  }

  HandleScope handle_scope(isolate);
  Local<Object> process = env_->process_object();

  if (!env_->can_call_into_js()) return;

  Local<Function> tick_callback = env_->tick_callback_function();

  // The tick is triggered before JS land calls SetTickCallback
  // to initializes the tick callback during bootstrap.
  CHECK(!tick_callback.IsEmpty());

  if (tick_callback->Call(context, process, 0, nullptr).IsEmpty()) {
    failed_ = true;
  }
  perform_stopping_check();
}

MaybeLocal<Value> InternalMakeCallback(Environment* env,
                                       Local<Object> resource,
                                       Local<Object> recv,
                                       const Local<Function> callback,
                                       int argc,
                                       Local<Value> argv[],
                                       async_context asyncContext) {
  CHECK(!recv.IsEmpty());
#ifdef DEBUG
  for (int i = 0; i < argc; i++)
    CHECK(!argv[i].IsEmpty());
#endif

  Local<Function> hook_cb = env->async_hooks_callback_trampoline();
  int flags = InternalCallbackScope::kNoFlags;
  bool use_async_hooks_trampoline = false;
  AsyncHooks* async_hooks = env->async_hooks();
  if (!hook_cb.IsEmpty()) {
    // Use the callback trampoline if there are any before or after hooks, or
    // we can expect some kind of usage of async_hooks.executionAsyncResource().
    flags = InternalCallbackScope::kSkipAsyncHooks;
    use_async_hooks_trampoline =
        async_hooks->fields()[AsyncHooks::kBefore] +
        async_hooks->fields()[AsyncHooks::kAfter] +
        async_hooks->fields()[AsyncHooks::kUsesExecutionAsyncResource] > 0;
  }

  InternalCallbackScope scope(env, resource, asyncContext, flags);
  if (scope.Failed()) {
    return MaybeLocal<Value>();
  }

  MaybeLocal<Value> ret;

  Local<Context> context = env->context();
  if (use_async_hooks_trampoline) {
    MaybeStackBuffer<Local<Value>, 16> args(3 + argc);
    args[0] = v8::Number::New(env->isolate(), asyncContext.async_id);
    args[1] = resource;
    args[2] = callback;
    for (int i = 0; i < argc; i++) {
      args[i + 3] = argv[i];
    }
    ret = hook_cb->Call(context, recv, args.length(), &args[0]);
  } else {
    ret = callback->Call(context, recv, argc, argv);
  }

  if (ret.IsEmpty()) {
    scope.MarkAsFailed();
    return MaybeLocal<Value>();
  }

  scope.Close();
  if (scope.Failed()) {
    return MaybeLocal<Value>();
  }

  return ret;
}

// Public MakeCallback()s

MaybeLocal<Value> MakeCallback(Isolate* isolate,
                               Local<Object> recv,
                               const char* method,
                               int argc,
                               Local<Value> argv[],
                               async_context asyncContext) {
  Local<String> method_string =
      String::NewFromUtf8(isolate, method).ToLocalChecked();
  return MakeCallback(isolate, recv, method_string, argc, argv, asyncContext);
}

MaybeLocal<Value> MakeCallback(Isolate* isolate,
                               Local<Object> recv,
                               Local<String> symbol,
                               int argc,
                               Local<Value> argv[],
                               async_context asyncContext) {
  // Check can_call_into_js() first because calling Get() might do so.
  Environment* env =
      Environment::GetCurrent(recv->GetCreationContext().ToLocalChecked());
  CHECK_NOT_NULL(env);
  if (!env->can_call_into_js()) return Local<Value>();

  Local<Value> callback_v;
  if (!recv->Get(isolate->GetCurrentContext(), symbol).ToLocal(&callback_v))
    return Local<Value>();
  if (!callback_v->IsFunction()) {
    // This used to return an empty value, but Undefined() makes more sense
    // since no exception is pending here.
    return Undefined(isolate);
  }
  Local<Function> callback = callback_v.As<Function>();
  return MakeCallback(isolate, recv, callback, argc, argv, asyncContext);
}

MaybeLocal<Value> MakeCallback(Isolate* isolate,
                               Local<Object> recv,
                               Local<Function> callback,
                               int argc,
                               Local<Value> argv[],
                               async_context asyncContext) {
  // Observe the following two subtleties:
  //
  // 1. The environment is retrieved from the callback function's context.
  // 2. The context to enter is retrieved from the environment.
  //
  // Because of the AssignToContext() call in src/node_contextify.cc,
  // the two contexts need not be the same.
  Environment* env =
      Environment::GetCurrent(callback->GetCreationContext().ToLocalChecked());
  CHECK_NOT_NULL(env);
  Context::Scope context_scope(env->context());
  MaybeLocal<Value> ret =
      InternalMakeCallback(env, recv, recv, callback, argc, argv, asyncContext);
  if (ret.IsEmpty() && env->async_callback_scope_depth() == 0) {
    // This is only for legacy compatibility and we may want to look into
    // removing/adjusting it.
    return Undefined(isolate);
  }
  return ret;
}

// Use this if you just want to safely invoke some JS callback and
// would like to retain the currently active async_context, if any.
// In case none is available, a fixed default context will be
// installed otherwise.
MaybeLocal<Value> MakeSyncCallback(Isolate* isolate,
                                   Local<Object> recv,
                                   Local<Function> callback,
                                   int argc,
                                   Local<Value> argv[]) {
  Environment* env =
      Environment::GetCurrent(callback->GetCreationContext().ToLocalChecked());
  CHECK_NOT_NULL(env);
  if (!env->can_call_into_js()) return Local<Value>();

  Local<Context> context = env->context();
  Context::Scope context_scope(context);
  if (env->async_callback_scope_depth()) {
    // There's another MakeCallback() on the stack, piggy back on it.
    // In particular, retain the current async_context.
    return callback->Call(context, recv, argc, argv);
  }

  // This is a toplevel invocation and the caller (intentionally)
  // didn't provide any async_context to run in. Install a default context.
  MaybeLocal<Value> ret =
    InternalMakeCallback(env, env->process_object(), recv, callback, argc, argv,
                         async_context{0, 0});
  return ret;
}

// Legacy MakeCallback()s

Local<Value> MakeCallback(Isolate* isolate,
                          Local<Object> recv,
                          const char* method,
                          int argc,
                          Local<Value>* argv) {
  EscapableHandleScope handle_scope(isolate);
  return handle_scope.Escape(
      MakeCallback(isolate, recv, method, argc, argv, {0, 0})
          .FromMaybe(Local<Value>()));
}

Local<Value> MakeCallback(Isolate* isolate,
                          Local<Object> recv,
                          Local<String> symbol,
                          int argc,
                          Local<Value>* argv) {
  EscapableHandleScope handle_scope(isolate);
  return handle_scope.Escape(
      MakeCallback(isolate, recv, symbol, argc, argv, {0, 0})
          .FromMaybe(Local<Value>()));
}

Local<Value> MakeCallback(Isolate* isolate,
                          Local<Object> recv,
                          Local<Function> callback,
                          int argc,
                          Local<Value>* argv) {
  EscapableHandleScope handle_scope(isolate);
  return handle_scope.Escape(
      MakeCallback(isolate, recv, callback, argc, argv, {0, 0})
          .FromMaybe(Local<Value>()));
}

}  // namespace node


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			#include "node.h"
2			#include "async_wrap-inl.h"
3			#include "env-inl.h"
4			#include "v8.h"
5
6			namespace node {
7
8			using v8::Context;
9			using v8::EscapableHandleScope;
10			using v8::Function;
11			using v8::HandleScope;
12			using v8::Isolate;
13			using v8::Local;
14			using v8::MaybeLocal;
15			using v8::Object;
16			using v8::String;
17			using v8::Value;
18
19		4	CallbackScope::CallbackScope(Isolate* isolate,
20			Local<Object> object,
21		4	async_context async_context)
22		4	: CallbackScope(Environment::GetCurrent(isolate), object, async_context) {}
23
24		115539	CallbackScope::CallbackScope(Environment* env,
25			Local<Object> object,
26		115539	async_context asyncContext)
27			: private_(new InternalCallbackScope(env,
28			object,
29		115539	asyncContext)),
30		231078	try_catch_(env->isolate()) {
31		115539	try_catch_.SetVerbose(true);
32		115539	}
33
34		115538	CallbackScope::~CallbackScope() {
35	✓✓	115538	if (try_catch_.HasCaught())
36		1	private_->MarkAsFailed();
37	✓✗	115538	delete private_;
38		115538	}
39
40		53002	InternalCallbackScope::InternalCallbackScope(AsyncWrap* async_wrap, int flags)
41			: InternalCallbackScope(async_wrap->env(),
42			async_wrap->object(),
43		53002	{ async_wrap->get_async_id(),
44		53002	async_wrap->get_trigger_async_id() },
45		53002	flags) {}
46
47		779863	InternalCallbackScope::InternalCallbackScope(Environment* env,
48			Local<Object> object,
49			const async_context& asyncContext,
50		779863	int flags)
51			: env_(env),
52			async_context_(asyncContext),
53			object_(object),
54		779863	skip_hooks_(flags & kSkipAsyncHooks),
55		1559726	skip_task_queues_(flags & kSkipTaskQueues) {
56	✗✓	779863	CHECK_NOT_NULL(env);
57		779863	env->PushAsyncCallbackScope();
58
59	✓✓	779863	if (!env->can_call_into_js()) {
60		11425	failed_ = true;
61		11425	return;
62			}
63
64		768438	Isolate* isolate = env->isolate();
65
66		1536876	HandleScope handle_scope(isolate);
67			// If you hit this assertion, you forgot to enter the v8::Context first.
68	✗✓	768438	CHECK_EQ(Environment::GetCurrent(isolate), env);
69
70		768438	env->isolate()->SetIdle(false);
71
72		768438	env->async_hooks()->push_async_context(
73			async_context_.async_id, async_context_.trigger_async_id, object);
74
75		768438	pushed_ids_ = true;
76
77	✓✓✓✓	768438	if (asyncContext.async_id != 0 && !skip_hooks_) {
78			// No need to check a return value because the application will exit if
79			// an exception occurs.
80		168531	AsyncWrap::EmitBefore(env, asyncContext.async_id);
81			}
82			}
83
84		1558768	InternalCallbackScope::~InternalCallbackScope() {
85		779415	Close();
86		779353	env_->PopAsyncCallbackScope();
87		779353	}
88
89		1178219	void InternalCallbackScope::Close() {
90	✓✓	1777141	if (closed_) return;
91		779529	closed_ = true;
92
93		779529	Isolate* isolate = env_->isolate();
94		1558882	auto idle = OnScopeLeave([&]() { isolate->SetIdle(true); });
95
96	✓✓	779529	if (!env_->can_call_into_js()) return;
97		1453736	auto perform_stopping_check = [&]() {
98	✓✓	1453736	if (env_->is_stopping()) {
99		77	MarkAsFailed();
100		77	env_->async_hooks()->clear_async_id_stack();
101			}
102		2221786	};
103		768050	perform_stopping_check();
104
105	✓✓✓✓ ✓✓	768050	if (!failed_ && async_context_.async_id != 0 && !skip_hooks_) {
106		168519	AsyncWrap::EmitAfter(env_, async_context_.async_id);
107			}
108
109	✓✗	768050	if (pushed_ids_)
110		768050	env_->async_hooks()->pop_async_context(async_context_.async_id);
111
112	✓✓	768049	if (failed_) return;
113
114	✓✓✓✓ ✓✓	767062	if (env_->async_callback_scope_depth() > 1 \|\| skip_task_queues_) {
115		82252	return;
116			}
117
118		684810	TickInfo* tick_info = env_->tick_info();
119
120	✓✓	684810	if (!env_->can_call_into_js()) return;
121
122		1369439	auto weakref_cleanup = OnScopeLeave([&]() { env_->RunWeakRefCleanup(); });
123
124		684807	Local<Context> context = env_->context();
125	✓✓	684807	if (!tick_info->has_tick_scheduled()) {
126		505290	context->GetMicrotaskQueue()->PerformCheckpoint(isolate);
127
128		505255	perform_stopping_check();
129			}
130
131			// Make sure the stack unwound properly. If there are nested MakeCallback's
132			// then it should return early and not reach this code.
133	✓✓	684772	if (env_->async_hooks()->fields()[AsyncHooks::kTotals]) {
134	✗✓	67806	CHECK_EQ(env_->execution_async_id(), 0);
135	✗✓	67806	CHECK_EQ(env_->trigger_async_id(), 0);
136			}
137
138	✓✓✓✓ ✓✓	684772	if (!tick_info->has_tick_scheduled() && !tick_info->has_rejection_to_warn()) {
139		504201	return;
140			}
141
142		180571	HandleScope handle_scope(isolate);
143		180571	Local<Object> process = env_->process_object();
144
145	✗✓	180571	if (!env_->can_call_into_js()) return;
146
147		180571	Local<Function> tick_callback = env_->tick_callback_function();
148
149			// The tick is triggered before JS land calls SetTickCallback
150			// to initializes the tick callback during bootstrap.
151	✗✓	180571	CHECK(!tick_callback.IsEmpty());
152
153	✓✓	361002	if (tick_callback->Call(context, process, 0, nullptr).IsEmpty()) {
154		223	failed_ = true;
155			}
156		180431	perform_stopping_check();
157			}
158
159		401131	MaybeLocal<Value> InternalMakeCallback(Environment* env,
160			Local<Object> resource,
161			Local<Object> recv,
162			const Local<Function> callback,
163			int argc,
164			Local<Value> argv[],
165			async_context asyncContext) {
166	✗✓	401131	CHECK(!recv.IsEmpty());
167			#ifdef DEBUG
168			for (int i = 0; i < argc; i++)
169			CHECK(!argv[i].IsEmpty());
170			#endif
171
172		401131	Local<Function> hook_cb = env->async_hooks_callback_trampoline();
173		401131	int flags = InternalCallbackScope::kNoFlags;
174		401131	bool use_async_hooks_trampoline = false;
175		401131	AsyncHooks* async_hooks = env->async_hooks();
176	✓✗	401131	if (!hook_cb.IsEmpty()) {
177			// Use the callback trampoline if there are any before or after hooks, or
178			// we can expect some kind of usage of async_hooks.executionAsyncResource().
179		401131	flags = InternalCallbackScope::kSkipAsyncHooks;
180		401131	use_async_hooks_trampoline =
181		401131	async_hooks->fields()[AsyncHooks::kBefore] +
182		401131	async_hooks->fields()[AsyncHooks::kAfter] +
183		401131	async_hooks->fields()[AsyncHooks::kUsesExecutionAsyncResource] > 0;
184			}
185
186		802090	InternalCallbackScope scope(env, resource, asyncContext, flags);
187	✓✓	401131	if (scope.Failed()) {
188		1254	return MaybeLocal<Value>();
189			}
190
191			MaybeLocal<Value> ret;
192
193		399877	Local<Context> context = env->context();
194	✓✓	399877	if (use_async_hooks_trampoline) {
195		30378	MaybeStackBuffer<Local<Value>, 16> args(3 + argc);
196		60756	args[0] = v8::Number::New(env->isolate(), asyncContext.async_id);
197		30378	args[1] = resource;
198		30378	args[2] = callback;
199	✓✓	41249	for (int i = 0; i < argc; i++) {
200		10871	args[i + 3] = argv[i];
201			}
202		30378	ret = hook_cb->Call(context, recv, args.length(), &args[0]);
203			} else {
204		369499	ret = callback->Call(context, recv, argc, argv);
205			}
206
207	✓✓	399819	if (ret.IsEmpty()) {
208		1015	scope.MarkAsFailed();
209		1015	return MaybeLocal<Value>();
210			}
211
212		398804	scope.Close();
213	✓✓	398690	if (scope.Failed()) {
214		136	return MaybeLocal<Value>();
215			}
216
217		398554	return ret;
218			}
219
220			// Public MakeCallback()s
221
222		9506	MaybeLocal<Value> MakeCallback(Isolate* isolate,
223			Local<Object> recv,
224			const char* method,
225			int argc,
226			Local<Value> argv[],
227			async_context asyncContext) {
228			Local<String> method_string =
229		9506	String::NewFromUtf8(isolate, method).ToLocalChecked();
230		9506	return MakeCallback(isolate, recv, method_string, argc, argv, asyncContext);
231			}
232
233		9514	MaybeLocal<Value> MakeCallback(Isolate* isolate,
234			Local<Object> recv,
235			Local<String> symbol,
236			int argc,
237			Local<Value> argv[],
238			async_context asyncContext) {
239			// Check can_call_into_js() first because calling Get() might do so.
240			Environment* env =
241		19028	Environment::GetCurrent(recv->GetCreationContext().ToLocalChecked());
242	✗✓	9514	CHECK_NOT_NULL(env);
243	✓✓	9529	if (!env->can_call_into_js()) return Local<Value>();
244
245			Local<Value> callback_v;
246	✗✓	18998	if (!recv->Get(isolate->GetCurrentContext(), symbol).ToLocal(&callback_v))
247			return Local<Value>();
248	✗✓	9499	if (!callback_v->IsFunction()) {
249			// This used to return an empty value, but Undefined() makes more sense
250			// since no exception is pending here.
251			return Undefined(isolate);
252			}
253		9499	Local<Function> callback = callback_v.As<Function>();
254		9499	return MakeCallback(isolate, recv, callback, argc, argv, asyncContext);
255			}
256
257		50360	MaybeLocal<Value> MakeCallback(Isolate* isolate,
258			Local<Object> recv,
259			Local<Function> callback,
260			int argc,
261			Local<Value> argv[],
262			async_context asyncContext) {
263			// Observe the following two subtleties:
264			//
265			// 1. The environment is retrieved from the callback function's context.
266			// 2. The context to enter is retrieved from the environment.
267			//
268			// Because of the AssignToContext() call in src/node_contextify.cc,
269			// the two contexts need not be the same.
270			Environment* env =
271		100720	Environment::GetCurrent(callback->GetCreationContext().ToLocalChecked());
272	✗✓	50360	CHECK_NOT_NULL(env);
273		50360	Context::Scope context_scope(env->context());
274			MaybeLocal<Value> ret =
275		50360	InternalMakeCallback(env, recv, recv, callback, argc, argv, asyncContext);
276	✓✓✓✓ ✓✓	50346	if (ret.IsEmpty() && env->async_callback_scope_depth() == 0) {
277			// This is only for legacy compatibility and we may want to look into
278			// removing/adjusting it.
279		1005	return Undefined(isolate);
280			}
281		49341	return ret;
282			}
283
284			// Use this if you just want to safely invoke some JS callback and
285			// would like to retain the currently active async_context, if any.
286			// In case none is available, a fixed default context will be
287			// installed otherwise.
288		16	MaybeLocal<Value> MakeSyncCallback(Isolate* isolate,
289			Local<Object> recv,
290			Local<Function> callback,
291			int argc,
292			Local<Value> argv[]) {
293			Environment* env =
294		32	Environment::GetCurrent(callback->GetCreationContext().ToLocalChecked());
295	✗✓	16	CHECK_NOT_NULL(env);
296	✗✓	16	if (!env->can_call_into_js()) return Local<Value>();
297
298		16	Local<Context> context = env->context();
299		16	Context::Scope context_scope(context);
300	✓✗	16	if (env->async_callback_scope_depth()) {
301			// There's another MakeCallback() on the stack, piggy back on it.
302			// In particular, retain the current async_context.
303		16	return callback->Call(context, recv, argc, argv);
304			}
305
306			// This is a toplevel invocation and the caller (intentionally)
307			// didn't provide any async_context to run in. Install a default context.
308			MaybeLocal<Value> ret =
309			InternalMakeCallback(env, env->process_object(), recv, callback, argc, argv,
310			async_context{0, 0});
311			return ret;
312			}
313
314			// Legacy MakeCallback()s
315
316			Local<Value> MakeCallback(Isolate* isolate,
317			Local<Object> recv,
318			const char* method,
319			int argc,
320			Local<Value>* argv) {
321			EscapableHandleScope handle_scope(isolate);
322			return handle_scope.Escape(
323			MakeCallback(isolate, recv, method, argc, argv, {0, 0})
324			.FromMaybe(Local<Value>()));
325			}
326
327			Local<Value> MakeCallback(Isolate* isolate,
328			Local<Object> recv,
329			Local<String> symbol,
330			int argc,
331			Local<Value>* argv) {
332			EscapableHandleScope handle_scope(isolate);
333			return handle_scope.Escape(
334			MakeCallback(isolate, recv, symbol, argc, argv, {0, 0})
335			.FromMaybe(Local<Value>()));
336			}
337
338			Local<Value> MakeCallback(Isolate* isolate,
339			Local<Object> recv,
340			Local<Function> callback,
341			int argc,
342			Local<Value>* argv) {
343			EscapableHandleScope handle_scope(isolate);
344			return handle_scope.Escape(
345			MakeCallback(isolate, recv, callback, argc, argv, {0, 0})
346			.FromMaybe(Local<Value>()));
347			}
348
349			} // namespace node