src: move internal loaders out of bootstrap_node.js

- Moves the creation of `process.binding()`, `process._linkedBinding()`
  `internalBinding()` and `NativeModule` into a separate file
  `lib/internal/bootstrap_loaders.js`, and documents them there.
  This file will be compiled and run before `bootstrap_node.js`, which
  means we now bootstrap the internal module & binding system before
  actually bootstrapping Node.js.
- Rename the special ID that can be used to require `NativeModule`
  as `internal/bootstrap_loaders` since it is setup there. Also put
  `internalBinding` in the object exported by `NativeModule.require`
  instead of putting it inside the `NativeModule.wrapper`
- Use the original `getBinding()` to get the source code of native
  modules instead of getting it from `process.binding('native')`
  so that users cannot fake native modules by modifying the binding
  object.
- Names the bootstrapping functions so their names show up
  in the stack trace.

PR-URL: https://github.com/nodejs/node/pull/19112
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>

.eslintrc.js

@@ -244,7 +244,6 @@ module.exports = {
     DTRACE_HTTP_SERVER_REQUEST: false,
     DTRACE_HTTP_SERVER_RESPONSE: false,
     DTRACE_NET_SERVER_CONNECTION: false,
-    DTRACE_NET_STREAM_END: false,
-    internalBinding: false,
+    DTRACE_NET_STREAM_END: false
   },
 };

lib/assert.js

@@ -36,7 +36,7 @@ const { openSync, closeSync, readSync } = require('fs');
 const { parseExpressionAt } = require('internal/deps/acorn/dist/acorn');
 const { inspect } = require('util');
 const { EOL } = require('os');
-const nativeModule = require('native_module');
+const { NativeModule } = require('internal/bootstrap_loaders');
 
 // Escape control characters but not \n and \t to keep the line breaks and
 // indentation intact.
@@ -163,7 +163,7 @@ function getErrMessage(call) {
   }
 
   // Skip Node.js modules!
-  if (filename.endsWith('.js') && nativeModule.exists(filename.slice(0, -3))) {
+  if (filename.endsWith('.js') && NativeModule.exists(filename.slice(0, -3))) {
     errorCache.set(identifier, undefined);
     return;
   }

lib/buffer.js

@@ -41,6 +41,7 @@ const {
 // that test/parallel/test-buffer-bindingobj-no-zerofill.js is written.
 let isAnyArrayBuffer;
 try {
+  const { internalBinding } = require('internal/bootstrap_loaders');
   isAnyArrayBuffer = internalBinding('types').isAnyArrayBuffer;
 } catch (e) {
   isAnyArrayBuffer = require('util').types.isAnyArrayBuffer;

lib/domain.js

@@ -34,6 +34,7 @@ const {
   ERR_UNHANDLED_ERROR
 } = require('internal/errors').codes;
 const { createHook } = require('async_hooks');
+const { internalBinding } = require('internal/bootstrap_loaders');
 
 // overwrite process.domain with a getter/setter that will allow for more
 // effective optimizations

lib/internal/bootstrap_loaders.js

@@ -0,0 +1,229 @@
+// This file creates the internal module & binding loaders used by built-in
+// modules. In contrast, user land modules are loaded using
+// lib/module.js (CommonJS Modules) or lib/internal/loader/* (ES Modules).
+//
+// This file is compiled and run by node.cc before bootstrap_node.js
+// was called, therefore the loaders are bootstraped before we start to
+// actually bootstrap Node.js. It creates the following objects:
+//
+// C++ binding loaders:
+// - process.binding(): the legacy C++ binding loader, accessible from user land
+//   because it is an object attached to the global process object.
+//   These C++ bindings are created using NODE_BUILTIN_MODULE_CONTEXT_AWARE()
+//   and have their nm_flags set to NM_F_BUILTIN. We do not make any guarantees
+//   about the stability of these bindings, but still have to take care of
+//   compatibility issues caused by them from time to time.
+// - process._linkedBinding(): intended to be used by embedders to add
+//   additional C++ bindings in their applications. These C++ bindings
+//   can be created using NODE_MODULE_CONTEXT_AWARE_CPP() with the flag
+//   NM_F_LINKED.
+// - internalBinding(): the private internal C++ binding loader, inaccessible
+//   from user land because they are only available from NativeModule.require()
+//   These C++ bindings are created using NODE_MODULE_CONTEXT_AWARE_INTERNAL()
+//   and have their nm_flags set to NM_F_INTERNAL.
+//
+// Internal JavaScript module loader:
+// - NativeModule: a minimal module system used to load the JavaScript core
+//   modules found in lib/**/*.js and deps/**/*.js. All core modules are
+//   compiled into the node binary via node_javascript.cc generated by js2c.py,
+//   so they can be loaded faster without the cost of I/O. This class makes the
+//   lib/internal/*, deps/internal/* modules and internalBinding() available by
+//   default to core modules, and lets the core modules require itself via
+//   require('internal/bootstrap_loaders') even when this file is not written in
+//   CommonJS style.
+//
+// Other objects:
+// - process.moduleLoadList: an array recording the bindings and the modules
+//   loaded in the process and the order in which they are loaded.
+
+'use strict';
+
+(function bootstrapInternalLoaders(process, getBinding, getLinkedBinding,
+                                   getInternalBinding) {
+
+  // Set up process.moduleLoadList
+  const moduleLoadList = [];
+  Object.defineProperty(process, 'moduleLoadList', {
+    value: moduleLoadList,
+    configurable: true,
+    enumerable: true,
+    writable: false
+  });
+
+  // Set up process.binding() and process._linkedBinding()
+  {
+    const bindingObj = Object.create(null);
+
+    process.binding = function binding(module) {
+      module = String(module);
+      let mod = bindingObj[module];
+      if (typeof mod !== 'object') {
+        mod = bindingObj[module] = getBinding(module);
+        moduleLoadList.push(`Binding ${module}`);
+      }
+      return mod;
+    };
+
+    process._linkedBinding = function _linkedBinding(module) {
+      module = String(module);
+      let mod = bindingObj[module];
+      if (typeof mod !== 'object')
+        mod = bindingObj[module] = getLinkedBinding(module);
+      return mod;
+    };
+  }
+
+  // Set up internalBinding() in the closure
+  let internalBinding;
+  {
+    const bindingObj = Object.create(null);
+    internalBinding = function internalBinding(module) {
+      let mod = bindingObj[module];
+      if (typeof mod !== 'object') {
+        mod = bindingObj[module] = getInternalBinding(module);
+        moduleLoadList.push(`Internal Binding ${module}`);
+      }
+      return mod;
+    };
+  }
+
+  // Minimal sandbox helper
+  const ContextifyScript = process.binding('contextify').ContextifyScript;
+  function runInThisContext(code, options) {
+    const script = new ContextifyScript(code, options);
+    return script.runInThisContext();
+  }
+
+  // Set up NativeModule
+  function NativeModule(id) {
+    this.filename = `${id}.js`;
+    this.id = id;
+    this.exports = {};
+    this.loaded = false;
+    this.loading = false;
+  }
+
+  NativeModule._source = getBinding('natives');
+  NativeModule._cache = {};
+
+  const config = getBinding('config');
+
+  // Think of this as module.exports in this file even though it is not
+  // written in CommonJS style.
+  const loaderExports = { internalBinding, NativeModule };
+  const loaderId = 'internal/bootstrap_loaders';
+  NativeModule.require = function(id) {
+    if (id === loaderId) {
+      return loaderExports;
+    }
+
+    const cached = NativeModule.getCached(id);
+    if (cached && (cached.loaded || cached.loading)) {
+      return cached.exports;
+    }
+
+    if (!NativeModule.exists(id)) {
+      // Model the error off the internal/errors.js model, but
+      // do not use that module given that it could actually be
+      // the one causing the error if there's a bug in Node.js
+      const err = new Error(`No such built-in module: ${id}`);
+      err.code = 'ERR_UNKNOWN_BUILTIN_MODULE';
+      err.name = 'Error [ERR_UNKNOWN_BUILTIN_MODULE]';
+      throw err;
+    }
+
+    moduleLoadList.push(`NativeModule ${id}`);
+
+    const nativeModule = new NativeModule(id);
+
+    nativeModule.cache();
+    nativeModule.compile();
+
+    return nativeModule.exports;
+  };
+
+  NativeModule.requireForDeps = function(id) {
+    if (!NativeModule.exists(id) ||
+        // TODO(TimothyGu): remove when DEP0084 reaches end of life.
+        id.startsWith('node-inspect/') ||
+        id.startsWith('v8/')) {
+      id = `internal/deps/${id}`;
+    }
+    return NativeModule.require(id);
+  };
+
+  NativeModule.getCached = function(id) {
+    return NativeModule._cache[id];
+  };
+
+  NativeModule.exists = function(id) {
+    return NativeModule._source.hasOwnProperty(id);
+  };
+
+  if (config.exposeInternals) {
+    NativeModule.nonInternalExists = function(id) {
+      // Do not expose this to user land even with --expose-internals
+      if (id === loaderId) {
+        return false;
+      }
+      return NativeModule.exists(id);
+    };
+
+    NativeModule.isInternal = function(id) {
+      // Do not expose this to user land even with --expose-internals
+      return id === loaderId;
+    };
+  } else {
+    NativeModule.nonInternalExists = function(id) {
+      return NativeModule.exists(id) && !NativeModule.isInternal(id);
+    };
+
+    NativeModule.isInternal = function(id) {
+      return id.startsWith('internal/');
+    };
+  }
+
+  NativeModule.getSource = function(id) {
+    return NativeModule._source[id];
+  };
+
+  NativeModule.wrap = function(script) {
+    return NativeModule.wrapper[0] + script + NativeModule.wrapper[1];
+  };
+
+  NativeModule.wrapper = [
+    '(function (exports, require, module, process) {',
+    '\n});'
+  ];
+
+  NativeModule.prototype.compile = function() {
+    let source = NativeModule.getSource(this.id);
+    source = NativeModule.wrap(source);
+
+    this.loading = true;
+
+    try {
+      const fn = runInThisContext(source, {
+        filename: this.filename,
+        lineOffset: 0,
+        displayErrors: true
+      });
+      const requireFn = this.id.startsWith('internal/deps/') ?
+        NativeModule.requireForDeps :
+        NativeModule.require;
+      fn(this.exports, requireFn, this, process);
+
+      this.loaded = true;
+    } finally {
+      this.loading = false;
+    }
+  };
+
+  NativeModule.prototype.cache = function() {
+    NativeModule._cache[this.id] = this;
+  };
+
+  // This will be passed to the bootstrapNodeJSCore function in
+  // bootstrap_node.js.
+  return loaderExports;
+});

lib/internal/bootstrap_node.js

@@ -4,11 +4,16 @@
 // responsible for bootstrapping the node.js core. As special caution is given
 // to the performance of the startup process, many dependencies are invoked
 // lazily.
+//
+// Before this file is run, lib/internal/bootstrap_loaders.js gets run first
+// to bootstrap the internal binding and module loaders, including
+// process.binding(), process._linkedBinding(), internalBinding() and
+// NativeModule. And then { internalBinding, NativeModule } will be passed
+// into this bootstrapper to bootstrap Node.js core.
 
 'use strict';
 
-(function(process) {
-  let internalBinding;
+(function bootstrapNodeJSCore(process, { internalBinding, NativeModule }) {
   const exceptionHandlerState = { captureFn: null };
 
   function startup() {
@@ -270,54 +275,6 @@
     perf.markMilestone(NODE_PERFORMANCE_MILESTONE_BOOTSTRAP_COMPLETE);
   }
 
-  const moduleLoadList = [];
-  Object.defineProperty(process, 'moduleLoadList', {
-    value: moduleLoadList,
-    configurable: true,
-    enumerable: true,
-    writable: false
-  });
-
-  {
-    const bindingObj = Object.create(null);
-
-    const getBinding = process.binding;
-    process.binding = function binding(module) {
-      module = String(module);
-      let mod = bindingObj[module];
-      if (typeof mod !== 'object') {
-        mod = bindingObj[module] = getBinding(module);
-        moduleLoadList.push(`Binding ${module}`);
-      }
-      return mod;
-    };
-
-    const getLinkedBinding = process._linkedBinding;
-    process._linkedBinding = function _linkedBinding(module) {
-      module = String(module);
-      let mod = bindingObj[module];
-      if (typeof mod !== 'object')
-        mod = bindingObj[module] = getLinkedBinding(module);
-      return mod;
-    };
-  }
-
-  {
-    const bindingObj = Object.create(null);
-
-    const getInternalBinding = process._internalBinding;
-    delete process._internalBinding;
-
-    internalBinding = function internalBinding(module) {
-      let mod = bindingObj[module];
-      if (typeof mod !== 'object') {
-        mod = bindingObj[module] = getInternalBinding(module);
-        moduleLoadList.push(`Internal Binding ${module}`);
-      }
-      return mod;
-    };
-  }
-
   function setupProcessObject() {
     process._setupProcessObject(pushValueToArray);
 
@@ -602,133 +559,5 @@
     new vm.Script(source, { displayErrors: true, filename });
   }
 
-  // Below you find a minimal module system, which is used to load the node
-  // core modules found in lib/*.js. All core modules are compiled into the
-  // node binary, so they can be loaded faster.
-
-  const ContextifyScript = process.binding('contextify').ContextifyScript;
-  function runInThisContext(code, options) {
-    const script = new ContextifyScript(code, options);
-    return script.runInThisContext();
-  }
-
-  function NativeModule(id) {
-    this.filename = `${id}.js`;
-    this.id = id;
-    this.exports = {};
-    this.loaded = false;
-    this.loading = false;
-  }
-
-  NativeModule._source = process.binding('natives');
-  NativeModule._cache = {};
-
-  const config = process.binding('config');
-
-  NativeModule.require = function(id) {
-    if (id === 'native_module') {
-      return NativeModule;
-    }
-
-    const cached = NativeModule.getCached(id);
-    if (cached && (cached.loaded || cached.loading)) {
-      return cached.exports;
-    }
-
-    if (!NativeModule.exists(id)) {
-      // Model the error off the internal/errors.js model, but
-      // do not use that module given that it could actually be
-      // the one causing the error if there's a bug in Node.js
-      const err = new Error(`No such built-in module: ${id}`);
-      err.code = 'ERR_UNKNOWN_BUILTIN_MODULE';
-      err.name = 'Error [ERR_UNKNOWN_BUILTIN_MODULE]';
-      throw err;
-    }
-
-    moduleLoadList.push(`NativeModule ${id}`);
-
-    const nativeModule = new NativeModule(id);
-
-    nativeModule.cache();
-    nativeModule.compile();
-
-    return nativeModule.exports;
-  };
-
-  NativeModule.requireForDeps = function(id) {
-    if (!NativeModule.exists(id) ||
-        // TODO(TimothyGu): remove when DEP0084 reaches end of life.
-        id.startsWith('node-inspect/') ||
-        id.startsWith('v8/')) {
-      id = `internal/deps/${id}`;
-    }
-    return NativeModule.require(id);
-  };
-
-  NativeModule.getCached = function(id) {
-    return NativeModule._cache[id];
-  };
-
-  NativeModule.exists = function(id) {
-    return NativeModule._source.hasOwnProperty(id);
-  };
-
-  if (config.exposeInternals) {
-    NativeModule.nonInternalExists = NativeModule.exists;
-
-    NativeModule.isInternal = function(id) {
-      return false;
-    };
-  } else {
-    NativeModule.nonInternalExists = function(id) {
-      return NativeModule.exists(id) && !NativeModule.isInternal(id);
-    };
-
-    NativeModule.isInternal = function(id) {
-      return id.startsWith('internal/');
-    };
-  }
-
-
-  NativeModule.getSource = function(id) {
-    return NativeModule._source[id];
-  };
-
-  NativeModule.wrap = function(script) {
-    return NativeModule.wrapper[0] + script + NativeModule.wrapper[1];
-  };
-
-  NativeModule.wrapper = [
-    '(function (exports, require, module, internalBinding, process) {',
-    '\n});'
-  ];
-
-  NativeModule.prototype.compile = function() {
-    let source = NativeModule.getSource(this.id);
-    source = NativeModule.wrap(source);
-
-    this.loading = true;
-
-    try {
-      const fn = runInThisContext(source, {
-        filename: this.filename,
-        lineOffset: 0,
-        displayErrors: true
-      });
-      const requireFn = this.id.startsWith('internal/deps/') ?
-        NativeModule.requireForDeps :
-        NativeModule.require;
-      fn(this.exports, requireFn, this, internalBinding, process);
-
-      this.loaded = true;
-    } finally {
-      this.loading = false;
-    }
-  };
-
-  NativeModule.prototype.cache = function() {
-    NativeModule._cache[this.id] = this;
-  };
-
   startup();
 });

lib/internal/encoding.js

@@ -17,6 +17,7 @@ const {
 
 const { isArrayBufferView } = require('internal/util/types');
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const {
   isArrayBuffer
 } = internalBinding('types');

lib/internal/loader/CreateDynamicModule.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const { ModuleWrap } = internalBinding('module_wrap');
 const debug = require('util').debuglog('esm');
 const ArrayJoin = Function.call.bind(Array.prototype.join);

lib/internal/loader/DefaultResolve.js

@@ -3,7 +3,7 @@
 const { URL } = require('url');
 const CJSmodule = require('module');
 const internalFS = require('internal/fs');
-const NativeModule = require('native_module');
+const { NativeModule, internalBinding } = require('internal/bootstrap_loaders');
 const { extname } = require('path');
 const { realpathSync } = require('fs');
 const preserveSymlinks = !!process.binding('config').preserveSymlinks;

lib/internal/loader/ModuleJob.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const { ModuleWrap } = internalBinding('module_wrap');
 const { SafeSet, SafePromise } = require('internal/safe_globals');
 const { decorateErrorStack } = require('internal/util');

lib/internal/loader/Translators.js

@@ -1,7 +1,7 @@
 'use strict';
 
+const { NativeModule, internalBinding } = require('internal/bootstrap_loaders');
 const { ModuleWrap } = internalBinding('module_wrap');
-const NativeModule = require('native_module');
 const internalCJSModule = require('internal/module');
 const CJSModule = require('module');
 const internalURLModule = require('internal/url');

lib/internal/process/modules.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const {
   setImportModuleDynamicallyCallback,
   setInitializeImportMetaObjectCallback

lib/internal/test/binding.js

@@ -8,6 +8,7 @@ process.emitWarning(
 // These exports should be scoped as specifically as possible
 // to avoid exposing APIs because even with that warning and
 // this file being internal people will still try to abuse it.
+const { internalBinding } = require('internal/bootstrap_loaders');
 module.exports = {
   ModuleWrap: internalBinding('module_wrap').ModuleWrap,
 };

lib/internal/util/comparisons.js

@@ -2,6 +2,7 @@
 
 const { compare } = process.binding('buffer');
 const { isArrayBufferView } = require('internal/util/types');
+const { internalBinding } = require('internal/bootstrap_loaders');
 const { isDate, isMap, isRegExp, isSet } = internalBinding('types');
 
 function objectToString(o) {

lib/internal/vm/Module.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const { emitExperimentalWarning } = require('internal/util');
 const { URL } = require('internal/url');
 const { kParsingContext, isContext } = process.binding('contextify');

lib/module.js

@@ -21,7 +21,7 @@
 
 'use strict';
 
-const NativeModule = require('native_module');
+const { NativeModule } = require('internal/bootstrap_loaders');
 const util = require('util');
 const { decorateErrorStack } = require('internal/util');
 const { getURLFromFilePath } = require('internal/url');

lib/string_decoder.js

@@ -22,6 +22,7 @@
 'use strict';
 
 const { Buffer } = require('buffer');
+const { internalBinding } = require('internal/bootstrap_loaders');
 const {
   kIncompleteCharactersStart,
   kIncompleteCharactersEnd,

lib/util.js

@@ -39,6 +39,7 @@ const {
   kRejected,
 } = process.binding('util');
 
+const { internalBinding } = require('internal/bootstrap_loaders');
 const types = internalBinding('types');
 Object.assign(types, require('internal/util/types'));
 const {

node.gyp

@@ -24,6 +24,7 @@
     'node_lib_target_name%': 'node_lib',
     'node_intermediate_lib_type%': 'static_library',
     'library_files': [
+      'lib/internal/bootstrap_loaders.js',
       'lib/internal/bootstrap_node.js',
       'lib/async_hooks.js',
       'lib/assert.js',

src/node.cc

@@ -2525,7 +2525,7 @@ static void ThrowIfNoSuchModule(Environment* env, const char* module_v) {
   env->ThrowError(errmsg);
 }
 
-static void Binding(const FunctionCallbackInfo<Value>& args) {
+static void GetBinding(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
   CHECK(args[0]->IsString());
@@ -2552,7 +2552,7 @@ static void Binding(const FunctionCallbackInfo<Value>& args) {
   args.GetReturnValue().Set(exports);
 }
 
-static void InternalBinding(const FunctionCallbackInfo<Value>& args) {
+static void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
   CHECK(args[0]->IsString());
@@ -2567,7 +2567,7 @@ static void InternalBinding(const FunctionCallbackInfo<Value>& args) {
   args.GetReturnValue().Set(exports);
 }
 
-static void LinkedBinding(const FunctionCallbackInfo<Value>& args) {
+static void GetLinkedBinding(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args.GetIsolate());
 
   CHECK(args[0]->IsString());
@@ -3265,10 +3265,6 @@ void SetupProcessObject(Environment* env,
   env->SetMethod(process, "uptime", Uptime);
   env->SetMethod(process, "memoryUsage", MemoryUsage);
 
-  env->SetMethod(process, "binding", Binding);
-  env->SetMethod(process, "_linkedBinding", LinkedBinding);
-  env->SetMethod(process, "_internalBinding", InternalBinding);
-
   env->SetMethod(process, "_setupProcessObject", SetupProcessObject);
   env->SetMethod(process, "_setupNextTick", SetupNextTick);
   env->SetMethod(process, "_setupPromises", SetupPromises);
@@ -3306,8 +3302,10 @@ static void RawDebug(const FunctionCallbackInfo<Value>& args) {
   fflush(stderr);
 }
 
-void LoadEnvironment(Environment* env) {
-  HandleScope handle_scope(env->isolate());
+
+static Local<Function> GetBootstrapper(Environment* env, Local<String> source,
+                                  Local<String> script_name) {
+  EscapableHandleScope scope(env->isolate());
 
   TryCatch try_catch(env->isolate());
 
@@ -3316,20 +3314,59 @@ void LoadEnvironment(Environment* env) {
   // are not safe to ignore.
   try_catch.SetVerbose(false);
 
-  // Execute the lib/internal/bootstrap_node.js file which was included as a
-  // static C string in node_natives.h by node_js2c.
-  // 'internal_bootstrap_node_native' is the string containing that source code.
-  Local<String> script_name = FIXED_ONE_BYTE_STRING(env->isolate(),
-                                                    "bootstrap_node.js");
-  Local<Value> f_value = ExecuteString(env, MainSource(env), script_name);
+  // Execute the factory javascript file
+  Local<Value> factory_v = ExecuteString(env, source, script_name);
   if (try_catch.HasCaught())  {
     ReportException(env, try_catch);
     exit(10);
   }
-  // The bootstrap_node.js file returns a function 'f'
-  CHECK(f_value->IsFunction());
 
-  Local<Function> f = Local<Function>::Cast(f_value);
+  CHECK(factory_v->IsFunction());
+  Local<Function> factory = Local<Function>::Cast(factory_v);
+
+  return scope.Escape(factory);
+}
+
+static bool ExecuteBootstrapper(Environment* env, Local<Function> factory,
+                                int argc, Local<Value> argv[],
+                                Local<Value>* out) {
+  bool ret = factory->Call(
+      env->context(), Null(env->isolate()), argc, argv).ToLocal(out);
+
+  // If there was an error during bootstrap then it was either handled by the
+  // FatalException handler or it's unrecoverable (e.g. max call stack
+  // exceeded). Either way, clear the stack so that the AsyncCallbackScope
+  // destructor doesn't fail on the id check.
+  // There are only two ways to have a stack size > 1: 1) the user manually
+  // called MakeCallback or 2) user awaited during bootstrap, which triggered
+  // _tickCallback().
+  if (!ret) {
+    env->async_hooks()->clear_async_id_stack();
+  }
+
+  return ret;
+}
+
+
+void LoadEnvironment(Environment* env) {
+  HandleScope handle_scope(env->isolate());
+
+  TryCatch try_catch(env->isolate());
+  // Disable verbose mode to stop FatalException() handler from trying
+  // to handle the exception. Errors this early in the start-up phase
+  // are not safe to ignore.
+  try_catch.SetVerbose(false);
+
+  // The factory scripts are lib/internal/bootstrap_loaders.js and
+  // lib/internal/bootstrap_node.js, each included as a static C string
+  // defined in node_javascript.h, generated in node_javascript.cc by
+  // node_js2c.
+  Local<Function> loaders_bootstrapper =
+      GetBootstrapper(env, LoadersBootstrapperSource(env),
+                 FIXED_ONE_BYTE_STRING(env->isolate(), "bootstrap_loaders.js"));
+  Local<Function> node_bootstrapper =
+      GetBootstrapper(env, NodeBootstrapperSource(env),
+                 FIXED_ONE_BYTE_STRING(env->isolate(), "bootstrap_node.js"));
 
   // Add a reference to the global object
   Local<Object> global = env->context()->Global();
@@ -3356,25 +3393,47 @@ void LoadEnvironment(Environment* env) {
   // (Allows you to set stuff on `global` from anywhere in JavaScript.)
   global->Set(FIXED_ONE_BYTE_STRING(env->isolate(), "global"), global);
 
-  // Now we call 'f' with the 'process' variable that we've built up with
-  // all our bindings. Inside bootstrap_node.js and internal/process we'll
-  // take care of assigning things to their places.
+  // Create binding loaders
+  v8::Local<v8::Function> get_binding_fn =
+      env->NewFunctionTemplate(GetBinding)->GetFunction(env->context())
+          .ToLocalChecked();
 
-  // We start the process this way in order to be more modular. Developers
-  // who do not like how bootstrap_node.js sets up the module system but do
-  // like Node's I/O bindings may want to replace 'f' with their own function.
-  Local<Value> arg = env->process_object();
+  v8::Local<v8::Function> get_linked_binding_fn =
+      env->NewFunctionTemplate(GetLinkedBinding)->GetFunction(env->context())
+          .ToLocalChecked();
 
-  auto ret = f->Call(env->context(), Null(env->isolate()), 1, &arg);
-  // If there was an error during bootstrap then it was either handled by the
-  // FatalException handler or it's unrecoverable (e.g. max call stack
-  // exceeded). Either way, clear the stack so that the AsyncCallbackScope
-  // destructor doesn't fail on the id check.
-  // There are only two ways to have a stack size > 1: 1) the user manually
-  // called MakeCallback or 2) user awaited during bootstrap, which triggered
-  // _tickCallback().
-  if (ret.IsEmpty())
-    env->async_hooks()->clear_async_id_stack();
+  v8::Local<v8::Function> get_internal_binding_fn =
+      env->NewFunctionTemplate(GetInternalBinding)->GetFunction(env->context())
+          .ToLocalChecked();
+
+  Local<Value> loaders_bootstrapper_args[] = {
+    env->process_object(),
+    get_binding_fn,
+    get_linked_binding_fn,
+    get_internal_binding_fn
+  };
+
+  // Bootstrap internal loaders
+  Local<Value> bootstrapped_loaders;
+  if (!ExecuteBootstrapper(env, loaders_bootstrapper,
+                           arraysize(loaders_bootstrapper_args),
+                           loaders_bootstrapper_args,
+                           &bootstrapped_loaders)) {
+    return;
+  }
+
+  // Bootstrap Node.js
+  Local<Value> bootstrapped_node;
+  Local<Value> node_bootstrapper_args[] = {
+    env->process_object(),
+    bootstrapped_loaders
+  };
+  if (!ExecuteBootstrapper(env, node_bootstrapper,
+                           arraysize(node_bootstrapper_args),
+                           node_bootstrapper_args,
+                           &bootstrapped_node)) {
+    return;
+  }
 }
 
 static void PrintHelp() {

src/node_javascript.h

@@ -29,7 +29,8 @@
 namespace node {
 
 void DefineJavaScript(Environment* env, v8::Local<v8::Object> target);
-v8::Local<v8::String> MainSource(Environment* env);
+v8::Local<v8::String> LoadersBootstrapperSource(Environment* env);
+v8::Local<v8::String> NodeBootstrapperSource(Environment* env);
 
 }  // namespace node
 

test/message/error_exit.out

@@ -12,4 +12,4 @@ AssertionError [ERR_ASSERTION]: 1 strictEqual 2
     at Function.Module._load (module.js:*:*)
     at Function.Module.runMain (module.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)

test/message/eval_messages.out

@@ -10,7 +10,7 @@ SyntaxError: Strict mode code may not include a with statement
     at Module._compile (module.js:*:*)
     at evalScript (bootstrap_node.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 42
 42
 [eval]:1
@@ -25,7 +25,7 @@ Error: hello
     at Module._compile (module.js:*:*)
     at evalScript (bootstrap_node.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 
 [eval]:1
 throw new Error("hello")
@@ -39,7 +39,7 @@ Error: hello
     at Module._compile (module.js:*:*)
     at evalScript (bootstrap_node.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 100
 [eval]:1
 var x = 100; y = x;
@@ -53,7 +53,7 @@ ReferenceError: y is not defined
     at Module._compile (module.js:*:*)
     at evalScript (bootstrap_node.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 
 [eval]:1
 var ______________________________________________; throw 10

test/message/events_unhandled_error_common_trace.out

@@ -19,4 +19,4 @@ Emitted 'error' event at:
     at Module._compile (module.js:*:*)
     [... lines matching original stack trace ...]
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)

test/message/events_unhandled_error_nexttick.out

@@ -11,10 +11,10 @@ Error
     at Function.Module._load (module.js:*:*)
     at Function.Module.runMain (module.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 Emitted 'error' event at:
     at process.nextTick (*events_unhandled_error_nexttick.js:*:*)
     at process._tickCallback (internal/process/next_tick.js:*:*)
     at Function.Module.runMain (module.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)

test/message/events_unhandled_error_sameline.out

@@ -11,9 +11,9 @@ Error
     at Function.Module._load (module.js:*:*)
     at Function.Module.runMain (module.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)
 Emitted 'error' event at:
     at Object.<anonymous> (*events_unhandled_error_sameline.js:*:*)
     at Module._compile (module.js:*:*)
     [... lines matching original stack trace ...]
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)

test/message/nexttick_throw.out

@@ -7,4 +7,4 @@ ReferenceError: undefined_reference_error_maker is not defined
     at process._tickCallback (internal/process/next_tick.js:*:*)
     at Function.Module.runMain (module.js:*:*)
     at startup (bootstrap_node.js:*:*)
-    at bootstrap_node.js:*:*
+    at bootstrapNodeJSCore (bootstrap_node.js:*:*)

test/parallel/test-loaders-hidden-from-users.js

@@ -0,0 +1,25 @@
+// Flags: --expose-internals
+
+'use strict';
+
+const common = require('../common');
+
+common.expectsError(
+  () => {
+    require('internal/bootstrap_loaders');
+  }, {
+    code: 'MODULE_NOT_FOUND',
+    message: 'Cannot find module \'internal/bootstrap_loaders\''
+  }
+);
+
+common.expectsError(
+  () => {
+    const source = 'module.exports = require("internal/bootstrap_loaders")';
+    process.binding('natives').owo = source;
+    require('owo');
+  }, {
+    code: 'MODULE_NOT_FOUND',
+    message: 'Cannot find module \'owo\''
+  }
+);

tools/js2c.py

@@ -185,7 +185,11 @@ namespace node {{
 
 {definitions}
 
-v8::Local<v8::String> MainSource(Environment* env) {{
+v8::Local<v8::String> LoadersBootstrapperSource(Environment* env) {{
+  return internal_bootstrap_loaders_value.ToStringChecked(env->isolate());
+}}
+
+v8::Local<v8::String> NodeBootstrapperSource(Environment* env) {{
   return internal_bootstrap_node_value.ToStringChecked(env->isolate());
 }}