// Hello, and welcome to hacking node.js! // // This file is invoked by `Realm::BootstrapNode()` in `src/node_realm.cc`, // and is responsible for setting up Node.js core before main scripts // under `lib/internal/main/` are executed. // // By default, Node.js binaries come with an embedded V8 startup snapshot // that is generated at build-time with a `node_mksnapshot` executable. // The snapshot generation code can be found in `SnapshotBuilder::Generate()` // from `src/node_snapshotable.cc`. // This snapshot captures the V8 heap initialized by scripts under // `lib/internal/bootstrap/`, including this file. When initializing the main // thread, Node.js deserializes the heap from the snapshot, instead of actually // running this script and others in `lib/internal/bootstrap/`. To disable this // behavior, pass `--no-node-snapshot` when starting the process so that // Node.js actually runs this script to initialize the heap. // // This script is expected not to perform any asynchronous operations itself // when being executed - those should be done in either // `lib/internal/process/pre_execution.js` or in main scripts. It should not // query any run-time states (e.g. command line arguments, environment // variables) when being executed - functions in this script that are invoked // at a later time can, however, query those states lazily. // The majority of the code here focuses on setting up the global object and // the process object in a synchronous, environment-independent manner. // // Scripts run before this file: // - `lib/internal/per_context/primordials.js`: this saves copies of JavaScript // builtins that won't be affected by user land monkey-patching for internal // modules to use. // - `lib/internal/per_context/domexception.js`: implementation of the // `DOMException` class. // - `lib/internal/per_context/messageport.js`: JS-side components of the // `MessagePort` implementation. // - `lib/internal/bootstrap/loaders.js`: this sets up internal binding and // module loaders, including `process.binding()`, `process._linkedBinding()`, // `internalBinding()` and `BuiltinModule`. // // The initialization done in this script is included in both the main thread // and the worker threads. After this, further initialization is done based // on the configuration of the Node.js instance by executing the scripts in // `lib/internal/bootstrap/switches/`. // // Then, depending on how the Node.js instance is launched, one of the main // scripts in `lib/internal/main` will be selected by C++ to start the actual // execution. They may run additional setups exported by // `lib/internal/process/pre_execution.js` depending on the run-time states. 'use strict'; // This file is compiled as if it's wrapped in a function with arguments // passed by `BuiltinLoader::CompileAndCall()`. /* global process, require, internalBinding, primordials */ setupPrepareStackTrace(); const { Array, ArrayPrototypeConcat, ArrayPrototypeFill, FunctionPrototypeCall, JSONParse, Number, NumberIsNaN, ObjectDefineProperty, ObjectGetPrototypeOf, ObjectSetPrototypeOf, ObjectFreeze, SymbolToStringTag, globalThis, } = primordials; const config = internalBinding('config'); const internalTimers = require('internal/timers'); const { defineOperation, deprecate, exposeInterface, } = require('internal/util'); const { validateInteger, } = require('internal/validators'); const { exiting_aliased_Uint32Array, getHiddenValue, } = internalBinding('util'); setupProcessObject(); setupGlobalProxy(); setupBuffer(); process.domain = null; { const exitingAliasedUint32Array = getHiddenValue(process, exiting_aliased_Uint32Array); ObjectDefineProperty(process, '_exiting', { __proto__: null, get() { return exitingAliasedUint32Array[0] === 1; }, set(value) { exitingAliasedUint32Array[0] = value ? 1 : 0; }, enumerable: true, configurable: true, }); } process._exiting = false; { let exitCode; ObjectDefineProperty(process, 'exitCode', { __proto__: null, get() { return exitCode; }, set(code) { if (code !== null && code !== undefined) { let value = code; if (typeof code === 'string' && code !== '' && NumberIsNaN((value = Number(code)))) { value = code; } validateInteger(value, 'code'); } exitCode = code; }, enumerable: true, configurable: false, }); } // process.config is serialized config.gypi const nativeModule = internalBinding('builtins'); const processConfig = JSONParse(nativeModule.config, (_key, value) => { // The `reviver` argument of the JSONParse method will visit all the values of // the parsed config, including the "root" object, so there is no need to // explicitly freeze the config outside of this method return ObjectFreeze(value); }); ObjectDefineProperty(process, 'config', { __proto__: null, enumerable: true, configurable: true, value: processConfig, }); require('internal/worker/js_transferable').setup(); // Bootstrappers for all threads, including worker threads and main thread const perThreadSetup = require('internal/process/per_thread'); const rawMethods = internalBinding('process_methods'); // Set up methods on the process object for all threads { process.dlopen = rawMethods.dlopen; process.uptime = rawMethods.uptime; // TODO(joyeecheung): either remove them or make them public process._getActiveRequests = rawMethods._getActiveRequests; process._getActiveHandles = rawMethods._getActiveHandles; process.getActiveResourcesInfo = function() { const timerCounts = internalTimers.getTimerCounts(); return ArrayPrototypeConcat( rawMethods._getActiveRequestsInfo(), rawMethods._getActiveHandlesInfo(), ArrayPrototypeFill(new Array(timerCounts.timeoutCount), 'Timeout'), ArrayPrototypeFill(new Array(timerCounts.immediateCount), 'Immediate')); }; // TODO(joyeecheung): remove these process.reallyExit = rawMethods.reallyExit; process._kill = rawMethods._kill; const wrapped = perThreadSetup.wrapProcessMethods(rawMethods); process._rawDebug = wrapped._rawDebug; process.cpuUsage = wrapped.cpuUsage; process.resourceUsage = wrapped.resourceUsage; process.memoryUsage = wrapped.memoryUsage; process.kill = wrapped.kill; process.exit = wrapped.exit; process.hrtime = perThreadSetup.hrtime; process.hrtime.bigint = perThreadSetup.hrtimeBigInt; process.openStdin = function() { process.stdin.resume(); return process.stdin; }; } const credentials = internalBinding('credentials'); if (credentials.implementsPosixCredentials) { process.getuid = credentials.getuid; process.geteuid = credentials.geteuid; process.getgid = credentials.getgid; process.getegid = credentials.getegid; process.getgroups = credentials.getgroups; } // Setup the callbacks that node::AsyncWrap will call when there are hooks to // process. They use the same functions as the JS embedder API. These callbacks // are setup immediately to prevent async_wrap.setupHooks() from being hijacked // and the cost of doing so is negligible. const { nativeHooks } = require('internal/async_hooks'); internalBinding('async_wrap').setupHooks(nativeHooks); const { setupTaskQueue, queueMicrotask } = require('internal/process/task_queues'); // Non-standard extensions: const { BroadcastChannel } = require('internal/worker/io'); exposeInterface(globalThis, 'BroadcastChannel', BroadcastChannel); defineOperation(globalThis, 'queueMicrotask', queueMicrotask); const timers = require('timers'); defineOperation(globalThis, 'clearImmediate', timers.clearImmediate); defineOperation(globalThis, 'setImmediate', timers.setImmediate); const { structuredClone, } = require('internal/structured_clone'); defineOperation(globalThis, 'structuredClone', structuredClone); // Set the per-Environment callback that will be called // when the TrackingTraceStateObserver updates trace state. // Note that when NODE_USE_V8_PLATFORM is true, the observer is // attached to the per-process TracingController. const { setTraceCategoryStateUpdateHandler } = internalBinding('trace_events'); setTraceCategoryStateUpdateHandler(perThreadSetup.toggleTraceCategoryState); // process.allowedNodeEnvironmentFlags ObjectDefineProperty(process, 'allowedNodeEnvironmentFlags', { __proto__: null, get() { const flags = perThreadSetup.buildAllowedFlags(); process.allowedNodeEnvironmentFlags = flags; return process.allowedNodeEnvironmentFlags; }, // If the user tries to set this to another value, override // this completely to that value. set(value) { ObjectDefineProperty(this, 'allowedNodeEnvironmentFlags', { __proto__: null, value, configurable: true, enumerable: true, writable: true }); }, enumerable: true, configurable: true }); // process.assert process.assert = deprecate( perThreadSetup.assert, 'process.assert() is deprecated. Please use the `assert` module instead.', 'DEP0100'); // TODO(joyeecheung): this property has not been well-maintained, should we // deprecate it in favor of a better API? const { isDebugBuild, hasOpenSSL, hasInspector } = config; const features = { inspector: hasInspector, debug: isDebugBuild, uv: true, ipv6: true, // TODO(bnoordhuis) ping libuv tls_alpn: hasOpenSSL, tls_sni: hasOpenSSL, tls_ocsp: hasOpenSSL, tls: hasOpenSSL, // This needs to be dynamic because --no-node-snapshot disables the // code cache even if the binary is built with embedded code cache. get cached_builtins() { return nativeModule.hasCachedBuiltins(); } }; ObjectDefineProperty(process, 'features', { __proto__: null, enumerable: true, writable: false, configurable: false, value: features }); { const { onGlobalUncaughtException, setUncaughtExceptionCaptureCallback, hasUncaughtExceptionCaptureCallback } = require('internal/process/execution'); // For legacy reasons this is still called `_fatalException`, even // though it is now a global uncaught exception handler. // The C++ land node::errors::TriggerUncaughtException grabs it // from the process object because it has been monkey-patchable. // TODO(joyeecheung): investigate whether process._fatalException // can be deprecated. process._fatalException = onGlobalUncaughtException; process.setUncaughtExceptionCaptureCallback = setUncaughtExceptionCaptureCallback; process.hasUncaughtExceptionCaptureCallback = hasUncaughtExceptionCaptureCallback; } const { emitWarning } = require('internal/process/warning'); process.emitWarning = emitWarning; // We initialize the tick callbacks and the timer callbacks last during // bootstrap to make sure that any operation done before this are synchronous. // If any ticks or timers are scheduled before this they are unlikely to work. { const { nextTick, runNextTicks } = setupTaskQueue(); process.nextTick = nextTick; // Used to emulate a tick manually in the JS land. // A better name for this function would be `runNextTicks` but // it has been exposed to the process object so we keep this legacy name // TODO(joyeecheung): either remove it or make it public process._tickCallback = runNextTicks; const { setupTimers } = internalBinding('timers'); const { processImmediate, processTimers, } = internalTimers.getTimerCallbacks(runNextTicks); // Sets two per-Environment callbacks that will be run from libuv: // - processImmediate will be run in the callback of the per-Environment // check handle. // - processTimers will be run in the callback of the per-Environment timer. setupTimers(processImmediate, processTimers); // Note: only after this point are the timers effective } // Preload modules so that they are included in the builtin snapshot. require('fs'); require('v8'); require('vm'); require('url'); require('internal/options'); if (config.hasOpenSSL) { require('crypto'); } function setupPrepareStackTrace() { const { setEnhanceStackForFatalException, setPrepareStackTraceCallback } = internalBinding('errors'); const { prepareStackTrace, fatalExceptionStackEnhancers: { beforeInspector, afterInspector } } = require('internal/errors'); // Tell our PrepareStackTraceCallback passed to the V8 API // to call prepareStackTrace(). setPrepareStackTraceCallback(prepareStackTrace); // Set the function used to enhance the error stack for printing setEnhanceStackForFatalException(beforeInspector, afterInspector); } function setupProcessObject() { const EventEmitter = require('events'); const origProcProto = ObjectGetPrototypeOf(process); ObjectSetPrototypeOf(origProcProto, EventEmitter.prototype); FunctionPrototypeCall(EventEmitter, process); ObjectDefineProperty(process, SymbolToStringTag, { __proto__: null, enumerable: false, writable: true, configurable: false, value: 'process' }); // Create global.process as getters so that we have a // deprecation path for these in ES Modules. // See https://github.com/nodejs/node/pull/26334. let _process = process; ObjectDefineProperty(globalThis, 'process', { __proto__: null, get() { return _process; }, set(value) { _process = value; }, enumerable: false, configurable: true, }); } function setupGlobalProxy() { ObjectDefineProperty(globalThis, SymbolToStringTag, { __proto__: null, value: 'global', writable: false, enumerable: false, configurable: true }); globalThis.global = globalThis; } function setupBuffer() { const { Buffer, } = require('buffer'); const bufferBinding = internalBinding('buffer'); // Only after this point can C++ use Buffer::New() bufferBinding.setBufferPrototype(Buffer.prototype); delete bufferBinding.setBufferPrototype; delete bufferBinding.zeroFill; // Create global.Buffer as getters so that we have a // deprecation path for these in ES Modules. // See https://github.com/nodejs/node/pull/26334. let _Buffer = Buffer; ObjectDefineProperty(globalThis, 'Buffer', { __proto__: null, get() { return _Buffer; }, set(value) { _Buffer = value; }, enumerable: false, configurable: true, }); }