All files / lib/internal/bootstrap loaders.js

97.03% Statements 360/371
94.54% Branches 52/55
94.11% Functions 16/17
97.03% Lines 360/371

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 37255x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 32x 32x 32x 32x 30x 7x 7x 7x 7x 7x 7x 30x 2x 2x 28x 28x 2x 2x 55x 55x 55x           55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 563022x 563022x 107695x 107695x 107695x 563022x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 4575216x 4575216x 4575216x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 367568x 55x 55x 55x 55x 428x 128400x 128400x 127972x 127972x 128400x 428x 55x 55x 99x 99x 55x 55x 198335x 198335x 198335x 55x 55x 55x 55x 716258x 716258x 55x 55x 119x 119x 55x 55x 55x 94030x         94030x 94030x 53426x 53426x 53426x 53426x 53426x 94028x 94028x 94028x 94030x 55x 55x 94396x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 53426x 94396x 55x 55x 55x 55x 55x 55x 148378x 148378x 147622x 4575216x 4575216x 4575216x 4575216x 4575216x 147622x 148378x 55x 55x 2910359x 2454531x 2454531x 455828x 455828x 455828x 455828x 455828x 2910359x 2910359x 2910359x 2910359x 2910359x 2910359x 2910359x 2910359x 455828x 455828x 455826x 455826x 455826x 2910359x 55x 55x 55x 55x 55x 55x 55x 55x 55x 55x 2849076x 2849076x 32744x 32744x 2816332x 2816332x 2816332x 2816332x 2849076x 2816329x 2849076x 55x 55x 55x 406x 406x     406x 406x 55x 55x 55x  
// This file creates the internal module & binding loaders used by built-in
// modules. In contrast, user land modules are loaded using
// lib/internal/modules/cjs/loader.js (CommonJS Modules) or
// lib/internal/modules/esm/* (ES Modules).
//
// This file is compiled and run by node.cc before bootstrap/node.js
// was called, therefore the loaders are bootstrapped 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 unless through `require('internal/test/binding')`.
//   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';
 
// This file is compiled as if it's wrapped in a function with arguments
// passed by node::RunBootstrapping()
/* global process, getLinkedBinding, getInternalBinding, primordials */
 
const {
  ArrayFrom,
  ArrayPrototypeMap,
  ArrayPrototypePush,
  ArrayPrototypeSlice,
  Error,
  ObjectCreate,
  ObjectDefineProperty,
  ObjectKeys,
  ObjectPrototypeHasOwnProperty,
  ReflectGet,
  SafeMap,
  SafeSet,
  String,
  StringPrototypeStartsWith,
  TypeError,
} = primordials;
 
// Set up process.moduleLoadList.
const moduleLoadList = [];
ObjectDefineProperty(process, 'moduleLoadList', {
  __proto__: null,
  value: moduleLoadList,
  configurable: true,
  enumerable: true,
  writable: false
});
 
 
// internalBindingAllowlist contains the name of internalBinding modules
// that are allowed for access via process.binding()... This is used
// to provide a transition path for modules that are being moved over to
// internalBinding.
const internalBindingAllowlist = new SafeSet([
  'async_wrap',
  'buffer',
  'cares_wrap',
  'config',
  'constants',
  'contextify',
  'crypto',
  'fs',
  'fs_event_wrap',
  'http_parser',
  'icu',
  'inspector',
  'js_stream',
  'natives',
  'os',
  'pipe_wrap',
  'process_wrap',
  'signal_wrap',
  'spawn_sync',
  'stream_wrap',
  'tcp_wrap',
  'tls_wrap',
  'tty_wrap',
  'udp_wrap',
  'url',
  'util',
  'uv',
  'v8',
  'zlib',
]);
 
const runtimeDeprecatedList = new SafeSet([
  'async_wrap',
  'crypto',
  'http_parser',
  'signal_wrap',
  'url',
  'v8',
]);
 
const legacyWrapperList = new SafeSet([
  'util',
]);
 
// Modules that can only be imported via the node: scheme.
const schemelessBlockList = new SafeSet([
  'test',
]);
 
// Set up process.binding() and process._linkedBinding().
{
  const bindingObj = ObjectCreate(null);
 
  process.binding = function binding(module) {
    module = String(module);
    // Deprecated specific process.binding() modules, but not all, allow
    // selective fallback to internalBinding for the deprecated ones.
    if (internalBindingAllowlist.has(module)) {
      if (runtimeDeprecatedList.has(module)) {
        runtimeDeprecatedList.delete(module);
        process.emitWarning(
          `Access to process.binding('${module}') is deprecated.`,
          'DeprecationWarning',
          'DEP0111');
      }
      if (legacyWrapperList.has(module)) {
        return nativeModuleRequire('internal/legacy/processbinding')[module]();
      }
      return internalBinding(module);
    }
    // eslint-disable-next-line no-restricted-syntax
    throw new Error(`No such module: ${module}`);
  };
 
  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.
/**
 * @type {InternalBinding}
 */
let internalBinding;
{
  const bindingObj = ObjectCreate(null);
  // eslint-disable-next-line no-global-assign
  internalBinding = function internalBinding(module) {
    let mod = bindingObj[module];
    if (typeof mod !== 'object') {
      mod = bindingObj[module] = getInternalBinding(module);
      ArrayPrototypePush(moduleLoadList, `Internal Binding ${module}`);
    }
    return mod;
  };
}
 
const loaderId = 'internal/bootstrap/loaders';
const {
  moduleIds,
  compileFunction
} = internalBinding('native_module');
 
const getOwn = (target, property, receiver) => {
  return ObjectPrototypeHasOwnProperty(target, property) ?
    ReflectGet(target, property, receiver) :
    undefined;
};
 
/**
 * An internal abstraction for the built-in JavaScript modules of Node.js.
 * Be careful not to expose this to user land unless --expose-internals is
 * used, in which case there is no compatibility guarantee about this class.
 */
class NativeModule {
  /**
   * A map from the module IDs to the module instances.
   * @type {Map<string, NativeModule>}
   */
  static map = new SafeMap(
    ArrayPrototypeMap(moduleIds, (id) => [id, new NativeModule(id)])
  );
 
  constructor(id) {
    this.filename = `${id}.js`;
    this.id = id;
    this.canBeRequiredByUsers = !StringPrototypeStartsWith(id, 'internal/');
 
    // The CJS exports object of the module.
    this.exports = {};
    // States used to work around circular dependencies.
    this.loaded = false;
    this.loading = false;
 
    // The following properties are used by the ESM implementation and only
    // initialized when the native module is loaded by users.
    /**
     * The C++ ModuleWrap binding used to interface with the ESM implementation.
     * @type {ModuleWrap|undefined}
     */
    this.module = undefined;
    /**
     * Exported names for the ESM imports.
     * @type {string[]|undefined}
     */
    this.exportKeys = undefined;
  }
 
  // To be called during pre-execution when --expose-internals is on.
  // Enables the user-land module loader to access internal modules.
  static exposeInternals() {
    for (const { 0: id, 1: mod } of NativeModule.map) {
      // Do not expose this to user land even with --expose-internals.
      if (id !== loaderId) {
        mod.canBeRequiredByUsers = true;
      }
    }
  }
 
  static exists(id) {
    return NativeModule.map.has(id);
  }
 
  static canBeRequiredByUsers(id) {
    const mod = NativeModule.map.get(id);
    return mod && mod.canBeRequiredByUsers;
  }
 
  // Determine if a core module can be loaded without the node: prefix. This
  // function does not validate if the module actually exists.
  static canBeRequiredWithoutScheme(id) {
    return !schemelessBlockList.has(id);
  }
 
  static getSchemeOnlyModuleNames() {
    return ArrayFrom(schemelessBlockList);
  }
 
  // Used by user-land module loaders to compile and load builtins.
  compileForPublicLoader() {
    if (!this.canBeRequiredByUsers) {
      // No code because this is an assertion against bugs
      // eslint-disable-next-line no-restricted-syntax
      throw new Error(`Should not compile ${this.id} for public use`);
    }
    this.compileForInternalLoader();
    if (!this.exportKeys) {
      // When using --expose-internals, we do not want to reflect the named
      // exports from core modules as this can trigger unnecessary getters.
      const internal = StringPrototypeStartsWith(this.id, 'internal/');
      this.exportKeys = internal ? [] : ObjectKeys(this.exports);
    }
    this.getESMFacade();
    this.syncExports();
    return this.exports;
  }
 
  getESMFacade() {
    if (this.module) return this.module;
    const { ModuleWrap } = internalBinding('module_wrap');
    const url = `node:${this.id}`;
    const nativeModule = this;
    const exportsKeys = ArrayPrototypeSlice(this.exportKeys);
    ArrayPrototypePush(exportsKeys, 'default');
    this.module = new ModuleWrap(
      url, undefined, exportsKeys,
      function() {
        nativeModule.syncExports();
        this.setExport('default', nativeModule.exports);
      });
    // Ensure immediate sync execution to capture exports now
    this.module.instantiate();
    this.module.evaluate(-1, false);
    return this.module;
  }
 
  // Provide named exports for all builtin libraries so that the libraries
  // may be imported in a nicer way for ESM users. The default export is left
  // as the entire namespace (module.exports) and updates when this function is
  // called so that APMs and other behavior are supported.
  syncExports() {
    const names = this.exportKeys;
    if (this.module) {
      for (let i = 0; i < names.length; i++) {
        const exportName = names[i];
        if (exportName === 'default') continue;
        this.module.setExport(exportName,
                              getOwn(this.exports, exportName, this.exports));
      }
    }
  }
 
  compileForInternalLoader() {
    if (this.loaded || this.loading) {
      return this.exports;
    }
 
    const id = this.id;
    this.loading = true;
 
    try {
      const requireFn = StringPrototypeStartsWith(this.id, 'internal/deps/') ?
        requireWithFallbackInDeps : nativeModuleRequire;
 
      const fn = compileFunction(id);
      fn(this.exports, requireFn, this, process, internalBinding, primordials);
 
      this.loaded = true;
    } finally {
      this.loading = false;
    }
 
    ArrayPrototypePush(moduleLoadList, `NativeModule ${id}`);
    return this.exports;
  }
}
 
// Think of this as module.exports in this file even though it is not
// written in CommonJS style.
const loaderExports = {
  internalBinding,
  NativeModule,
  require: nativeModuleRequire
};
 
function nativeModuleRequire(id) {
  if (id === loaderId) {
    return loaderExports;
  }
 
  const mod = NativeModule.map.get(id);
  // Can't load the internal errors module from here, have to use a raw error.
  // eslint-disable-next-line no-restricted-syntax
  if (!mod) throw new TypeError(`Missing internal module '${id}'`);
  return mod.compileForInternalLoader();
}
 
// Allow internal modules from dependencies to require
// other modules from dependencies by providing fallbacks.
function requireWithFallbackInDeps(request) {
  if (!NativeModule.map.has(request)) {
    request = `internal/deps/${request}`;
  }
  return nativeModuleRequire(request);
}
 
// Pass the exports back to C++ land for C++ internals to use.
return loaderExports;