1 #include "node_binding.h"
2 #include "node_errors.h"
3 #include <atomic>
4 #include "env-inl.h"
5 #include "node_native_module_env.h"
6 #include "util.h"
7
8 #if HAVE_OPENSSL
9 #define NODE_BUILTIN_OPENSSL_MODULES(V) V(crypto) V(tls_wrap)
10 #else
11 #define NODE_BUILTIN_OPENSSL_MODULES(V)
12 #endif
13
14 #if NODE_HAVE_I18N_SUPPORT
15 #define NODE_BUILTIN_ICU_MODULES(V) V(icu)
16 #else
17 #define NODE_BUILTIN_ICU_MODULES(V)
18 #endif
19
20 #if HAVE_INSPECTOR
21 #define NODE_BUILTIN_PROFILER_MODULES(V) V(profiler)
22 #else
23 #define NODE_BUILTIN_PROFILER_MODULES(V)
24 #endif
25
26 #if HAVE_DTRACE || HAVE_ETW
27 #define NODE_BUILTIN_DTRACE_MODULES(V) V(dtrace)
28 #else
29 #define NODE_BUILTIN_DTRACE_MODULES(V)
30 #endif
31
32 // A list of built-in modules. In order to do module registration
33 // in node::Init(), need to add built-in modules in the following list.
34 // Then in binding::RegisterBuiltinModules(), it calls modules' registration
35 // function. This helps the built-in modules are loaded properly when
36 // node is built as static library. No need to depend on the
37 // __attribute__((constructor)) like mechanism in GCC.
38 #define NODE_BUILTIN_STANDARD_MODULES(V) \
39 V(async_wrap) \
40 V(buffer) \
41 V(cares_wrap) \
42 V(config) \
43 V(contextify) \
44 V(credentials) \
45 V(errors) \
46 V(fs) \
47 V(fs_dir) \
48 V(fs_event_wrap) \
49 V(heap_utils) \
50 V(http2) \
51 V(http_parser) \
52 V(http_parser_llhttp) \
53 V(inspector) \
54 V(js_stream) \
55 V(js_udp_wrap) \
56 V(messaging) \
57 V(module_wrap) \
58 V(native_module) \
59 V(options) \
60 V(os) \
61 V(performance) \
62 V(pipe_wrap) \
63 V(process_wrap) \
64 V(process_methods) \
65 V(report) \
66 V(serdes) \
67 V(signal_wrap) \
68 V(spawn_sync) \
69 V(stream_pipe) \
70 V(stream_wrap) \
71 V(string_decoder) \
72 V(symbols) \
73 V(task_queue) \
74 V(tcp_wrap) \
75 V(timers) \
76 V(trace_events) \
77 V(tty_wrap) \
78 V(types) \
79 V(udp_wrap) \
80 V(url) \
81 V(util) \
82 V(uv) \
83 V(v8) \
84 V(wasi) \
85 V(worker) \
86 V(watchdog) \
87 V(zlib)
88
89 #define NODE_BUILTIN_MODULES(V) \
90 NODE_BUILTIN_STANDARD_MODULES(V) \
91 NODE_BUILTIN_OPENSSL_MODULES(V) \
92 NODE_BUILTIN_ICU_MODULES(V) \
93 NODE_BUILTIN_PROFILER_MODULES(V) \
94 NODE_BUILTIN_DTRACE_MODULES(V)
95
96 // This is used to load built-in modules. Instead of using
97 // __attribute__((constructor)), we call the _register_<modname>
98 // function for each built-in modules explicitly in
99 // binding::RegisterBuiltinModules(). This is only forward declaration.
100 // The definitions are in each module's implementation when calling
101 // the NODE_MODULE_CONTEXT_AWARE_INTERNAL.
102 #define V(modname) void _register_##modname();
103 NODE_BUILTIN_MODULES(V)
104 #undef V
105
106 #ifdef _AIX
107 // On AIX, dlopen() behaves differently from other operating systems, in that
108 // it returns unique values from each call, rather than identical values, when
109 // loading the same handle.
110 // We try to work around that by providing wrappers for the dlopen() family of
111 // functions, and using st_dev and st_ino for the file that is to be loaded
112 // as keys for a cache.
113
114 namespace node {
115 namespace dlwrapper {
116
117 struct dl_wrap {
118 uint64_t st_dev;
119 uint64_t st_ino;
120 uint64_t refcount;
121 void* real_handle;
122
123 struct hash {
operator ()node::dlwrapper::dl_wrap::hash124 size_t operator()(const dl_wrap* wrap) const {
125 return std::hash<uint64_t>()(wrap->st_dev) ^
126 std::hash<uint64_t>()(wrap->st_ino);
127 }
128 };
129
130 struct equal {
operator ()node::dlwrapper::dl_wrap::equal131 bool operator()(const dl_wrap* a,
132 const dl_wrap* b) const {
133 return a->st_dev == b->st_dev && a->st_ino == b->st_ino;
134 }
135 };
136 };
137
138 static Mutex dlhandles_mutex;
139 static std::unordered_set<dl_wrap*, dl_wrap::hash, dl_wrap::equal>
140 dlhandles;
141 static thread_local std::string dlerror_storage;
142
wrapped_dlerror()143 char* wrapped_dlerror() {
144 return &dlerror_storage[0];
145 }
146
wrapped_dlopen(const char * filename,int flags)147 void* wrapped_dlopen(const char* filename, int flags) {
148 CHECK_NOT_NULL(filename); // This deviates from the 'real' dlopen().
149 Mutex::ScopedLock lock(dlhandles_mutex);
150
151 uv_fs_t req;
152 auto cleanup = OnScopeLeave([&]() { uv_fs_req_cleanup(&req); });
153 int rc = uv_fs_stat(nullptr, &req, filename, nullptr);
154
155 if (rc != 0) {
156 dlerror_storage = uv_strerror(rc);
157 return nullptr;
158 }
159
160 dl_wrap search = {
161 req.statbuf.st_dev,
162 req.statbuf.st_ino,
163 0, nullptr
164 };
165
166 auto it = dlhandles.find(&search);
167 if (it != dlhandles.end()) {
168 (*it)->refcount++;
169 return *it;
170 }
171
172 void* real_handle = dlopen(filename, flags);
173 if (real_handle == nullptr) {
174 dlerror_storage = dlerror();
175 return nullptr;
176 }
177 dl_wrap* wrap = new dl_wrap();
178 wrap->st_dev = req.statbuf.st_dev;
179 wrap->st_ino = req.statbuf.st_ino;
180 wrap->refcount = 1;
181 wrap->real_handle = real_handle;
182 dlhandles.insert(wrap);
183 return wrap;
184 }
185
wrapped_dlclose(void * handle)186 int wrapped_dlclose(void* handle) {
187 Mutex::ScopedLock lock(dlhandles_mutex);
188 dl_wrap* wrap = static_cast<dl_wrap*>(handle);
189 int ret = 0;
190 CHECK_GE(wrap->refcount, 1);
191 if (--wrap->refcount == 0) {
192 ret = dlclose(wrap->real_handle);
193 if (ret != 0) dlerror_storage = dlerror();
194 dlhandles.erase(wrap);
195 delete wrap;
196 }
197 return ret;
198 }
199
wrapped_dlsym(void * handle,const char * symbol)200 void* wrapped_dlsym(void* handle, const char* symbol) {
201 if (handle == RTLD_DEFAULT || handle == RTLD_NEXT)
202 return dlsym(handle, symbol);
203 dl_wrap* wrap = static_cast<dl_wrap*>(handle);
204 return dlsym(wrap->real_handle, symbol);
205 }
206
207 #define dlopen node::dlwrapper::wrapped_dlopen
208 #define dlerror node::dlwrapper::wrapped_dlerror
209 #define dlclose node::dlwrapper::wrapped_dlclose
210 #define dlsym node::dlwrapper::wrapped_dlsym
211
212 } // namespace dlwrapper
213 } // namespace node
214
215 #endif // _AIX
216
217 #ifdef __linux__
libc_may_be_musl()218 static bool libc_may_be_musl() {
219 static std::atomic_bool retval; // Cache the return value.
220 static std::atomic_bool has_cached_retval { false };
221 if (has_cached_retval) return retval;
222 retval = dlsym(RTLD_DEFAULT, "gnu_get_libc_version") == nullptr;
223 has_cached_retval = true;
224 return retval;
225 }
226 #else // __linux__
libc_may_be_musl()227 static bool libc_may_be_musl() { return false; }
228 #endif // __linux__
229
230 namespace node {
231
232 using v8::Context;
233 using v8::Exception;
234 using v8::FunctionCallbackInfo;
235 using v8::Local;
236 using v8::NewStringType;
237 using v8::Object;
238 using v8::String;
239 using v8::Value;
240
241 // Globals per process
242 static node_module* modlist_internal;
243 static node_module* modlist_linked;
244 static thread_local node_module* thread_local_modpending;
245
246 // This is set by node::Init() which is used by embedders
247 bool node_is_initialized = false;
248
node_module_register(void * m)249 extern "C" void node_module_register(void* m) {
250 struct node_module* mp = reinterpret_cast<struct node_module*>(m);
251
252 if (mp->nm_flags & NM_F_INTERNAL) {
253 mp->nm_link = modlist_internal;
254 modlist_internal = mp;
255 } else if (!node_is_initialized) {
256 // "Linked" modules are included as part of the node project.
257 // Like builtins they are registered *before* node::Init runs.
258 mp->nm_flags = NM_F_LINKED;
259 mp->nm_link = modlist_linked;
260 modlist_linked = mp;
261 } else {
262 thread_local_modpending = mp;
263 }
264 }
265
266 namespace binding {
267
268 static struct global_handle_map_t {
269 public:
setnode::binding::global_handle_map_t270 void set(void* handle, node_module* mod) {
271 CHECK_NE(handle, nullptr);
272 Mutex::ScopedLock lock(mutex_);
273
274 map_[handle].module = mod;
275 // We need to store this flag internally to avoid a chicken-and-egg problem
276 // during cleanup. By the time we actually use the flag's value,
277 // the shared object has been unloaded, and its memory would be gone,
278 // making it impossible to access fields of `mod` --
279 // unless `mod` *is* dynamically allocated, but we cannot know that
280 // without checking the flag.
281 map_[handle].wants_delete_module = mod->nm_flags & NM_F_DELETEME;
282 map_[handle].refcount++;
283 }
284
get_and_increase_refcountnode::binding::global_handle_map_t285 node_module* get_and_increase_refcount(void* handle) {
286 CHECK_NE(handle, nullptr);
287 Mutex::ScopedLock lock(mutex_);
288
289 auto it = map_.find(handle);
290 if (it == map_.end()) return nullptr;
291 it->second.refcount++;
292 return it->second.module;
293 }
294
erasenode::binding::global_handle_map_t295 void erase(void* handle) {
296 CHECK_NE(handle, nullptr);
297 Mutex::ScopedLock lock(mutex_);
298
299 auto it = map_.find(handle);
300 if (it == map_.end()) return;
301 CHECK_GE(it->second.refcount, 1);
302 if (--it->second.refcount == 0) {
303 if (it->second.wants_delete_module)
304 delete it->second.module;
305 map_.erase(handle);
306 }
307 }
308
309 private:
310 Mutex mutex_;
311 struct Entry {
312 unsigned int refcount;
313 bool wants_delete_module;
314 node_module* module;
315 };
316 std::unordered_map<void*, Entry> map_;
317 } global_handle_map;
318
DLib(const char * filename,int flags)319 DLib::DLib(const char* filename, int flags)
320 : filename_(filename), flags_(flags), handle_(nullptr) {}
321
322 #ifdef __POSIX__
Open()323 bool DLib::Open() {
324 handle_ = dlopen(filename_.c_str(), flags_);
325 if (handle_ != nullptr) return true;
326 errmsg_ = dlerror();
327 return false;
328 }
329
Close()330 void DLib::Close() {
331 if (handle_ == nullptr) return;
332
333 if (libc_may_be_musl()) {
334 // musl libc implements dlclose() as a no-op which returns 0.
335 // As a consequence, trying to re-load a previously closed addon at a later
336 // point will not call its static constructors, which Node.js uses.
337 // Therefore, when we may be using musl libc, we assume that the shared
338 // object exists indefinitely and keep it in our handle map.
339 return;
340 }
341
342 int err = dlclose(handle_);
343 if (err == 0) {
344 if (has_entry_in_global_handle_map_)
345 global_handle_map.erase(handle_);
346 }
347 handle_ = nullptr;
348 }
349
GetSymbolAddress(const char * name)350 void* DLib::GetSymbolAddress(const char* name) {
351 return dlsym(handle_, name);
352 }
353 #else // !__POSIX__
Open()354 bool DLib::Open() {
355 int ret = uv_dlopen(filename_.c_str(), &lib_);
356 if (ret == 0) {
357 handle_ = static_cast<void*>(lib_.handle);
358 return true;
359 }
360 errmsg_ = uv_dlerror(&lib_);
361 uv_dlclose(&lib_);
362 return false;
363 }
364
Close()365 void DLib::Close() {
366 if (handle_ == nullptr) return;
367 if (has_entry_in_global_handle_map_)
368 global_handle_map.erase(handle_);
369 uv_dlclose(&lib_);
370 handle_ = nullptr;
371 }
372
GetSymbolAddress(const char * name)373 void* DLib::GetSymbolAddress(const char* name) {
374 void* address;
375 if (0 == uv_dlsym(&lib_, name, &address)) return address;
376 return nullptr;
377 }
378 #endif // !__POSIX__
379
SaveInGlobalHandleMap(node_module * mp)380 void DLib::SaveInGlobalHandleMap(node_module* mp) {
381 has_entry_in_global_handle_map_ = true;
382 global_handle_map.set(handle_, mp);
383 }
384
GetSavedModuleFromGlobalHandleMap()385 node_module* DLib::GetSavedModuleFromGlobalHandleMap() {
386 has_entry_in_global_handle_map_ = true;
387 return global_handle_map.get_and_increase_refcount(handle_);
388 }
389
390 using InitializerCallback = void (*)(Local<Object> exports,
391 Local<Value> module,
392 Local<Context> context);
393
GetInitializerCallback(DLib * dlib)394 inline InitializerCallback GetInitializerCallback(DLib* dlib) {
395 const char* name = "node_register_module_v" STRINGIFY(NODE_MODULE_VERSION);
396 return reinterpret_cast<InitializerCallback>(dlib->GetSymbolAddress(name));
397 }
398
GetNapiInitializerCallback(DLib * dlib)399 inline napi_addon_register_func GetNapiInitializerCallback(DLib* dlib) {
400 const char* name =
401 STRINGIFY(NAPI_MODULE_INITIALIZER_BASE) STRINGIFY(NAPI_MODULE_VERSION);
402 return reinterpret_cast<napi_addon_register_func>(
403 dlib->GetSymbolAddress(name));
404 }
405
406 // DLOpen is process.dlopen(module, filename, flags).
407 // Used to load 'module.node' dynamically shared objects.
408 //
409 // FIXME(bnoordhuis) Not multi-context ready. TBD how to resolve the conflict
410 // when two contexts try to load the same shared object. Maybe have a shadow
411 // cache that's a plain C list or hash table that's shared across contexts?
DLOpen(const FunctionCallbackInfo<Value> & args)412 void DLOpen(const FunctionCallbackInfo<Value>& args) {
413 Environment* env = Environment::GetCurrent(args);
414 auto context = env->context();
415
416 CHECK_NULL(thread_local_modpending);
417
418 if (args.Length() < 2) {
419 env->ThrowError("process.dlopen needs at least 2 arguments.");
420 return;
421 }
422
423 int32_t flags = DLib::kDefaultFlags;
424 if (args.Length() > 2 && !args[2]->Int32Value(context).To(&flags)) {
425 return env->ThrowTypeError("flag argument must be an integer.");
426 }
427
428 Local<Object> module;
429 Local<Object> exports;
430 Local<Value> exports_v;
431 if (!args[0]->ToObject(context).ToLocal(&module) ||
432 !module->Get(context, env->exports_string()).ToLocal(&exports_v) ||
433 !exports_v->ToObject(context).ToLocal(&exports)) {
434 return; // Exception pending.
435 }
436
437 node::Utf8Value filename(env->isolate(), args[1]); // Cast
438 env->TryLoadAddon(*filename, flags, [&](DLib* dlib) {
439 static Mutex dlib_load_mutex;
440 Mutex::ScopedLock lock(dlib_load_mutex);
441
442 const bool is_opened = dlib->Open();
443
444 // Objects containing v14 or later modules will have registered themselves
445 // on the pending list. Activate all of them now. At present, only one
446 // module per object is supported.
447 node_module* mp = thread_local_modpending;
448 thread_local_modpending = nullptr;
449
450 if (!is_opened) {
451 Local<String> errmsg =
452 OneByteString(env->isolate(), dlib->errmsg_.c_str());
453 dlib->Close();
454 #ifdef _WIN32
455 // Windows needs to add the filename into the error message
456 errmsg = String::Concat(
457 env->isolate(), errmsg, args[1]->ToString(context).ToLocalChecked());
458 #endif // _WIN32
459 env->isolate()->ThrowException(Exception::Error(errmsg));
460 return false;
461 }
462
463 if (mp != nullptr) {
464 if (mp->nm_context_register_func == nullptr) {
465 if (env->force_context_aware()) {
466 dlib->Close();
467 THROW_ERR_NON_CONTEXT_AWARE_DISABLED(env);
468 return false;
469 }
470 }
471 mp->nm_dso_handle = dlib->handle_;
472 dlib->SaveInGlobalHandleMap(mp);
473 } else {
474 if (auto callback = GetInitializerCallback(dlib)) {
475 callback(exports, module, context);
476 return true;
477 } else if (auto napi_callback = GetNapiInitializerCallback(dlib)) {
478 napi_module_register_by_symbol(exports, module, context, napi_callback);
479 return true;
480 } else {
481 mp = dlib->GetSavedModuleFromGlobalHandleMap();
482 if (mp == nullptr || mp->nm_context_register_func == nullptr) {
483 dlib->Close();
484 char errmsg[1024];
485 snprintf(errmsg,
486 sizeof(errmsg),
487 "Module did not self-register: '%s'.",
488 *filename);
489 env->ThrowError(errmsg);
490 return false;
491 }
492 }
493 }
494
495 // -1 is used for N-API modules
496 if ((mp->nm_version != -1) && (mp->nm_version != NODE_MODULE_VERSION)) {
497 // Even if the module did self-register, it may have done so with the
498 // wrong version. We must only give up after having checked to see if it
499 // has an appropriate initializer callback.
500 if (auto callback = GetInitializerCallback(dlib)) {
501 callback(exports, module, context);
502 return true;
503 }
504 char errmsg[1024];
505 snprintf(errmsg,
506 sizeof(errmsg),
507 "The module '%s'"
508 "\nwas compiled against a different Node.js version using"
509 "\nNODE_MODULE_VERSION %d. This version of Node.js requires"
510 "\nNODE_MODULE_VERSION %d. Please try re-compiling or "
511 "re-installing\nthe module (for instance, using `npm rebuild` "
512 "or `npm install`).",
513 *filename,
514 mp->nm_version,
515 NODE_MODULE_VERSION);
516
517 // NOTE: `mp` is allocated inside of the shared library's memory, calling
518 // `dlclose` will deallocate it
519 dlib->Close();
520 env->ThrowError(errmsg);
521 return false;
522 }
523 CHECK_EQ(mp->nm_flags & NM_F_BUILTIN, 0);
524
525 // Do not keep the lock while running userland addon loading code.
526 Mutex::ScopedUnlock unlock(lock);
527 if (mp->nm_context_register_func != nullptr) {
528 mp->nm_context_register_func(exports, module, context, mp->nm_priv);
529 } else if (mp->nm_register_func != nullptr) {
530 mp->nm_register_func(exports, module, mp->nm_priv);
531 } else {
532 dlib->Close();
533 env->ThrowError("Module has no declared entry point.");
534 return false;
535 }
536
537 return true;
538 });
539
540 // Tell coverity that 'handle' should not be freed when we return.
541 // coverity[leaked_storage]
542 }
543
FindModule(struct node_module * list,const char * name,int flag)544 inline struct node_module* FindModule(struct node_module* list,
545 const char* name,
546 int flag) {
547 struct node_module* mp;
548
549 for (mp = list; mp != nullptr; mp = mp->nm_link) {
550 if (strcmp(mp->nm_modname, name) == 0) break;
551 }
552
553 CHECK(mp == nullptr || (mp->nm_flags & flag) != 0);
554 return mp;
555 }
556
InitModule(Environment * env,node_module * mod,Local<String> module)557 static Local<Object> InitModule(Environment* env,
558 node_module* mod,
559 Local<String> module) {
560 Local<Object> exports = Object::New(env->isolate());
561 // Internal bindings don't have a "module" object, only exports.
562 CHECK_NULL(mod->nm_register_func);
563 CHECK_NOT_NULL(mod->nm_context_register_func);
564 Local<Value> unused = Undefined(env->isolate());
565 mod->nm_context_register_func(exports, unused, env->context(), mod->nm_priv);
566 return exports;
567 }
568
ThrowIfNoSuchModule(Environment * env,const char * module_v)569 static void ThrowIfNoSuchModule(Environment* env, const char* module_v) {
570 char errmsg[1024];
571 snprintf(errmsg, sizeof(errmsg), "No such module: %s", module_v);
572 env->ThrowError(errmsg);
573 }
574
GetInternalBinding(const FunctionCallbackInfo<Value> & args)575 void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
576 Environment* env = Environment::GetCurrent(args);
577
578 CHECK(args[0]->IsString());
579
580 Local<String> module = args[0].As<String>();
581 node::Utf8Value module_v(env->isolate(), module);
582 Local<Object> exports;
583
584 node_module* mod = FindModule(modlist_internal, *module_v, NM_F_INTERNAL);
585 if (mod != nullptr) {
586 exports = InitModule(env, mod, module);
587 } else if (!strcmp(*module_v, "constants")) {
588 exports = Object::New(env->isolate());
589 CHECK(
590 exports->SetPrototype(env->context(), Null(env->isolate())).FromJust());
591 DefineConstants(env->isolate(), exports);
592 } else if (!strcmp(*module_v, "natives")) {
593 exports = native_module::NativeModuleEnv::GetSourceObject(env->context());
594 // Legacy feature: process.binding('natives').config contains stringified
595 // config.gypi
596 CHECK(exports
597 ->Set(env->context(),
598 env->config_string(),
599 native_module::NativeModuleEnv::GetConfigString(
600 env->isolate()))
601 .FromJust());
602 } else {
603 return ThrowIfNoSuchModule(env, *module_v);
604 }
605
606 args.GetReturnValue().Set(exports);
607 }
608
GetLinkedBinding(const FunctionCallbackInfo<Value> & args)609 void GetLinkedBinding(const FunctionCallbackInfo<Value>& args) {
610 Environment* env = Environment::GetCurrent(args);
611
612 CHECK(args[0]->IsString());
613
614 Local<String> module_name = args[0].As<String>();
615
616 node::Utf8Value module_name_v(env->isolate(), module_name);
617 const char* name = *module_name_v;
618 node_module* mod = nullptr;
619
620 // Iterate from here to the nearest non-Worker Environment to see if there's
621 // a linked binding defined locally rather than through the global list.
622 Environment* cur_env = env;
623 while (mod == nullptr && cur_env != nullptr) {
624 Mutex::ScopedLock lock(cur_env->extra_linked_bindings_mutex());
625 mod = FindModule(cur_env->extra_linked_bindings_head(), name, NM_F_LINKED);
626 cur_env = cur_env->worker_parent_env();
627 }
628
629 if (mod == nullptr)
630 mod = FindModule(modlist_linked, name, NM_F_LINKED);
631
632 if (mod == nullptr) {
633 char errmsg[1024];
634 snprintf(errmsg,
635 sizeof(errmsg),
636 "No such module was linked: %s",
637 *module_name_v);
638 return env->ThrowError(errmsg);
639 }
640
641 Local<Object> module = Object::New(env->isolate());
642 Local<Object> exports = Object::New(env->isolate());
643 Local<String> exports_prop =
644 String::NewFromUtf8(env->isolate(), "exports", NewStringType::kNormal)
645 .ToLocalChecked();
646 module->Set(env->context(), exports_prop, exports).Check();
647
648 if (mod->nm_context_register_func != nullptr) {
649 mod->nm_context_register_func(
650 exports, module, env->context(), mod->nm_priv);
651 } else if (mod->nm_register_func != nullptr) {
652 mod->nm_register_func(exports, module, mod->nm_priv);
653 } else {
654 return env->ThrowError("Linked module has no declared entry point.");
655 }
656
657 auto effective_exports =
658 module->Get(env->context(), exports_prop).ToLocalChecked();
659
660 args.GetReturnValue().Set(effective_exports);
661 }
662
663 // Call built-in modules' _register_<module name> function to
664 // do module registration explicitly.
RegisterBuiltinModules()665 void RegisterBuiltinModules() {
666 #define V(modname) _register_##modname();
667 NODE_BUILTIN_MODULES(V)
668 #undef V
669 }
670
671 } // namespace binding
672 } // namespace node
673