Revert "deps,lib,tools: remove jitless and lite modes"

Newer version of V8 no longer supports
--allow-overwriting-for-next-flag and there's no way to
override the preset flag now. Revert the commit to allow
users to opt-in into the flags if still necessary.

This reverts commit 7e39b87.

Signed-off-by: Joyee Cheung <joyeec9h3@gmail.com>
PR-URL: #66516
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>

Author: joyeecheung

BUILDING.md

@@ -98,9 +98,6 @@ and libc version. The table below lists the support tier for each supported
 combination. A list of [supported compile toolchains](#supported-toolchains) is
 also supplied for tier 1 platforms.
 
-Node.js requires WebAssembly for built-in functionality, including `fetch()` and
-TypeScript support. JIT-less execution and V8 lite mode are not supported.
-
 **For production applications, run Node.js on supported platforms only (Tier 1 or 2).**
 
 Node.js does not support a platform version if a vendor has expired support

configure.py

@@ -1224,6 +1224,14 @@
     default=False,
     help='compile V8 with debug checks and runtime debugging features enabled')
 
+parser.add_argument('--v8-lite-mode',
+    action='store_true',
+    dest='v8_lite_mode',
+    default=False,
+    help='compile V8 in lite mode for constrained environments (lowers V8 '+
+         'memory footprint, but also implies no just-in-time compilation ' +
+         'support, thus much slower execution)')
+
 parser.add_argument('--v8-enable-object-print',
     action='store_true',
     dest='v8_enable_object_print',
@@ -1310,10 +1318,6 @@
 
 (options, args) = parser.parse_known_args()
 
-# Reject the removed option before forwarding unknown arguments to GYP.
-if any(arg.split('=', 1)[0] == '--v8-lite-mode' for arg in args):
-  parser.error('--v8-lite-mode is no longer supported; Node.js requires WebAssembly')
-
 # Expand ~ in the install prefix now, it gets written to multiple files.
 options.prefix = str(Path(options.prefix or '').expanduser())
 
@@ -2227,8 +2231,9 @@ def configure_library(lib, output, pkgname=None):
 def configure_v8(o, configs):
   set_configuration_variable(configs, 'v8_enable_v8_checks', release=0, debug=1)
 
-  o['variables']['v8_enable_webassembly'] = 1
+  o['variables']['v8_enable_webassembly'] = 0 if options.v8_lite_mode else 1
   o['variables']['v8_enable_javascript_promise_hooks'] = 1
+  o['variables']['v8_enable_lite_mode'] = 1 if options.v8_lite_mode else 0
   is_gdbjit_supported_arch = (
       'x64' in o['variables']['target_arch'] or
       'ia32' in o['variables']['target_arch'] or

doc/api/cli.md

@@ -2196,6 +2196,19 @@ added: v0.7.7
 
 Opens the REPL even if stdin does not appear to be a terminal.
 
+### `--jitless`
+
+<!-- YAML
+added: v12.0.0
+-->
+
+> Stability: 1 - Experimental. This flag is inherited from V8 and is subject to
+> change upstream.
+
+Disable [runtime allocation of executable memory][jitless]. This may be
+required on some platforms for security reasons. It can also reduce attack
+surface on other platforms, but the performance impact may be severe.
+
 ### `--localstorage-file=file`
 
 <!-- YAML
@@ -4398,6 +4411,7 @@ V8 options that are allowed are:
 * `--enable-etw-stack-walking`
 * `--expose-gc`
 * `--interpreted-frames-native-stack`
+* `--jitless`
 * `--max-heap-size`
 * `--max-old-space-size`
 * `--max-semi-space-size`
@@ -4768,6 +4782,8 @@ documented here:
 
 ### `--interpreted-frames-native-stack`
 
+### `--jitless`
+
 ### `--max-heap-size`
 
 Specifies the maximum heap size (in megabytes) for the process.
@@ -4960,6 +4976,7 @@ node --stack-trace-limit=12 -p -e "Error.stackTraceLimit" # prints 12
 [environment_variables]: #environment-variables-1
 [filtering tests by name]: test.md#filtering-tests-by-name
 [global setup and teardown]: test.md#global-setup-and-teardown
+[jitless]: https://v8.dev/blog/jitless
 [libuv threadpool documentation]: https://docs.libuv.org/en/latest/threadpool.html
 [module compile cache]: module.md#module-compile-cache
 [preloading asynchronous module customization hooks]: module.md#registration-of-asynchronous-customization-hooks

doc/api/errors.md

@@ -3645,6 +3645,14 @@ The WASI instance has already started.
 
 The WASI instance has not been started.
 
+<a id="ERR_WEBASSEMBLY_NOT_SUPPORTED"></a>
+
+### `ERR_WEBASSEMBLY_NOT_SUPPORTED`
+
+A feature requiring WebAssembly was used, but WebAssembly is not supported or
+has been disabled in the current environment (for example, when running with
+`--jitless`).
+
 <a id="ERR_WEBASSEMBLY_RESPONSE"></a>
 
 ### `ERR_WEBASSEMBLY_RESPONSE`
@@ -4480,18 +4488,6 @@ The linker function returned a module for which linking has failed.
 
 The module must be successfully linked before instantiation.
 
-<a id="ERR_WEBASSEMBLY_NOT_SUPPORTED"></a>
-
-### `ERR_WEBASSEMBLY_NOT_SUPPORTED`
-
-<!-- YAML
-removed: REPLACEME
--->
-
-A feature requiring WebAssembly was used in an environment where WebAssembly
-was unavailable. Node.js now requires WebAssembly and no longer supports
-JIT-less execution.
-
 <a id="ERR_WORKER_UNSUPPORTED_EXTENSION"></a>
 
 ### `ERR_WORKER_UNSUPPORTED_EXTENSION`

doc/node.1

@@ -1175,6 +1175,11 @@ See V8 Inspector integration for Node.js for further explanation on Node.js debu
 .It Fl i , Fl -interactive
 Opens the REPL even if stdin does not appear to be a terminal.
 .
+.It Fl -jitless
+Disable runtime allocation of executable memory. This may be
+required on some platforms for security reasons. It can also reduce attack
+surface on other platforms, but the performance impact may be severe.
+.
 .It Fl -localstorage-file Ns = Ns Ar file
 The file used to store \fBlocalStorage\fR data. If the file does not exist, it is
 created the first time \fBlocalStorage\fR is accessed. The same file may be shared
@@ -2523,6 +2528,8 @@ V8 options that are allowed are:
 .It
 \fB--interpreted-frames-native-stack\fR
 .It
+\fB--jitless\fR
+.It
 \fB--max-heap-size\fR
 .It
 \fB--max-old-space-size\fR

lib/eslint.config_partial.mjs

@@ -298,8 +298,8 @@ export default [
           name: 'URLSearchParams',
           message: "Use `const { URLSearchParams } = require('internal/url');` instead of the global.",
         },
-        // WebAssembly is unavailable during snapshot building and must be
-        // accessed lazily at runtime.
+        // WebAssembly is not available in primordials because it can be
+        // disabled with --jitless CLI flag.
         {
           name: 'WebAssembly',
           message: 'Use `const { WebAssembly } = globalThis;` instead of the global.',

lib/internal/errors.js

@@ -1981,6 +1981,9 @@ E('ERR_VM_MODULE_NOT_MODULE',
   'Provided module is not an instance of Module', Error);
 E('ERR_VM_MODULE_STATUS', 'Module status %s', Error);
 E('ERR_WASI_ALREADY_STARTED', 'WASI instance has already started', Error);
+E('ERR_WEBASSEMBLY_NOT_SUPPORTED',
+  'WebAssembly is not supported in this environment, but is required for %s',
+  Error);
 E('ERR_WEBASSEMBLY_RESPONSE', 'WebAssembly response %s', TypeError);
 E('ERR_WORKER_HANDLE_NOT_TRANSFERABLE',
   '%s cannot be transferred in its current state; it must be a freshly ' +

lib/internal/freeze_intrinsics.js

@@ -363,16 +363,18 @@ module.exports = function() {
     ArrayPrototypePush(intrinsics, SharedArrayBuffer);
   }
 
-  ArrayPrototypePush(intrinsicPrototypes,
-                     WebAssembly.Module.prototype,
-                     WebAssembly.Instance.prototype,
-                     WebAssembly.Table.prototype,
-                     WebAssembly.Memory.prototype,
-                     WebAssembly.CompileError.prototype,
-                     WebAssembly.LinkError.prototype,
-                     WebAssembly.RuntimeError.prototype,
-  );
-  ArrayPrototypePush(intrinsics, WebAssembly);
+  if (typeof WebAssembly !== 'undefined') {
+    ArrayPrototypePush(intrinsicPrototypes,
+                       WebAssembly.Module.prototype,
+                       WebAssembly.Instance.prototype,
+                       WebAssembly.Table.prototype,
+                       WebAssembly.Memory.prototype,
+                       WebAssembly.CompileError.prototype,
+                       WebAssembly.LinkError.prototype,
+                       WebAssembly.RuntimeError.prototype,
+    );
+    ArrayPrototypePush(intrinsics, WebAssembly);
+  }
 
   if (typeof Intl !== 'undefined') {
     ArrayPrototypePush(intrinsicPrototypes,

lib/internal/util.js

@@ -45,13 +45,15 @@ const {
   SymbolPrototypeGetDescription,
   SymbolReplace,
   SymbolSplit,
+  globalThis,
 } = primordials;
 
 const {
   codes: {
     ERR_NO_CRYPTO,
     ERR_NO_TYPESCRIPT,
     ERR_UNKNOWN_SIGNAL,
+    ERR_WEBASSEMBLY_NOT_SUPPORTED,
   },
   isErrorStackTraceLimitWritable,
   overrideStackTrace,
@@ -243,6 +245,8 @@ function assertCrypto() {
 function assertTypeScript() {
   if (noTypeScript)
     throw new ERR_NO_TYPESCRIPT();
+  if (globalThis.WebAssembly === undefined)
+    throw new ERR_WEBASSEMBLY_NOT_SUPPORTED('TypeScript');
 }
 
 /**

src/node.cc

@@ -48,10 +48,6 @@
 #include "node_version.h"
 #include "permission/env_permission.h"
 
-#if defined(V8_JITLESS) || defined(V8_LITE_MODE)
-#error Node.js does not support interpreter-only V8 builds.
-#endif
-
 #if HAVE_OPENSSL
 #include "ncrypto.h"
 #if OPENSSL_VERSION_MAJOR >= 3
@@ -1112,12 +1108,6 @@ static ExitCode InitializeNodeWithArgsInternal(
 
   allow_env_sources.Finish();
 
-  // Node.js requires WebAssembly for built-in functionality. Override these
-  // modes after all option sources, before V8 applies their implications.
-  // Explicitly allow overriding even when contradiction checks are enabled.
-  V8::SetFlagsFromString("--allow-overwriting-for-next-flag --no-lite-mode "
-                         "--allow-overwriting-for-next-flag --no-jitless");
-
   // Every option source has now been parsed, so cross-source option
   // constraints can finally be validated.
   CheckGlobalBenchOptions(errors);