From e5b837a1085e2f7c6dcea10d057976b192e0c76a Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Thu, 11 Nov 2021 12:20:34 -0800
Subject: [PATCH] process: introduce process.availableV8flags

---
 doc/api/process.md                            |  57 +-
 lib/internal/bootstrap/node.js                |  21 +
 lib/internal/process/per_thread.js            | 714 ++++++++++++++++--
 .../test-process-available-v8-flags.js        | 111 +++
 4 files changed, 821 insertions(+), 82 deletions(-)
 create mode 100644 test/parallel/test-process-available-v8-flags.js

diff --git a/doc/api/process.md b/doc/api/process.md
index ecd53469ca4221..82cd407e51c1fb 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -818,7 +818,7 @@ return `true` in the following cases:
 * Flags may omit leading single (`-`) or double (`--`) dashes; e.g.,
   `inspect-brk` for `--inspect-brk`, or `r` for `-r`.
 * Flags passed through to V8 (as listed in `--v8-options`) may replace
-  one or more _non-leading_ dashes for an underscore, or vice-versa;
+  one or more _non-leading_ dashes for an underscore, or vice versa;
   e.g., `--perf_basic_prof`, `--perf-basic-prof`, `--perf_basic-prof`,
   etc.
 * Flags may contain one or more equals (`=`) characters; all
@@ -955,6 +955,61 @@ $ bash -c 'exec -a customArgv0 ./node'
 'customArgv0'
 ```
 
+## `process.availableV8Flags`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+* {Set}
+
+The `process.availableV8Flags` property is a special, read-only `Set` of
+command-line flags. If a user supplies one or more of these flags, Node.js will
+pass the flags through to V8. These flags are not supported by Node.js. Avoid
+using these flags if at all possible. They may or may not work correctly, and
+their behavior can change in breaking ways in any Node.js release.
+
+`process.availableV8Flags` extends `Set`, but overrides `Set.prototype.has` to
+recognize several different possible flag representations.
+`process.availableV8Flags.has()` will return `true` in the following cases:
+
+* Flags may omit leading single (`-`) or double (`--`) dashes.
+* Flags may replace one or more non-leading dashes for an underscore, or vice
+  versa.
+* Flags may contain one or more equals (`=`) characters and all
+  characters after and including the first equals will be ignored.
+
+When iterating over `process.availableV8Flags`, flags will appear only once.
+Each will begin with one or more dashes. Flags will contain underscores instead
+of non-leading dashes.
+
+```mjs
+import { availableV8Flags } from 'process';
+
+availableV8Flags.forEach((flag) => {
+  // --abort-on-contradictory-flags
+  // --abort-on-uncaught-exception
+  // --adjust-os-scheduling-parameters
+  // ...
+});
+```
+
+```cjs
+const { availableV8Flags } = require('process');
+
+availableV8Flags.forEach((flag) => {
+  // --abort-on-contradictory-flags
+  // --abort-on-uncaught-exception
+  // --adjust-os-scheduling-parameters
+  // ...
+});
+```
+
+The methods `add()`, `clear()`, and `delete()` of `process.availableV8Flags` do
+nothing.
+
 ## `process.channel`
 
 <!-- YAML
diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
index e58538b34cb17e..386612e5cbaefd 100644
--- a/lib/internal/bootstrap/node.js
+++ b/lib/internal/bootstrap/node.js
@@ -255,6 +255,27 @@ ObjectDefineProperty(process, 'allowedNodeEnvironmentFlags', {
   configurable: true
 });
 
+// process.availableV8Flags
+ObjectDefineProperty(process, 'availableV8Flags', {
+  get() {
+    const flags = perThreadSetup.buildAvailableV8Flags();
+    process.availableV8Flags = flags;
+    return process.availableV8Flags;
+  },
+  // If the user tries to set this to another value, override
+  // this completely to that value.
+  set(value) {
+    ObjectDefineProperty(this, 'availableV8Flags', {
+      value,
+      configurable: true,
+      enumerable: true,
+      writable: true
+    });
+  },
+  enumerable: true,
+  configurable: true
+});
+
 // process.assert
 process.assert = deprecate(
   perThreadSetup.assert,
diff --git a/lib/internal/process/per_thread.js b/lib/internal/process/per_thread.js
index 709bcb7b137639..43def145005d0a 100644
--- a/lib/internal/process/per_thread.js
+++ b/lib/internal/process/per_thread.js
@@ -199,7 +199,8 @@ function wrapProcessMethods(binding) {
 
     // eslint-disable-next-line eqeqeq
     if (pid != (pid | 0)) {
-      throw new ERR_INVALID_ARG_TYPE('pid', 'number', pid);
+      throw new ERR_INVALID_ARG_TYPE('pid',
+                                     'number', pid);
     }
 
     // Preserve null signal
@@ -260,6 +261,82 @@ const replaceUnderscoresRegex = /_/g;
 const leadingDashesRegex = /^--?/;
 const trailingValuesRegex = /=.*$/;
 
+class FlagsSet extends Set {
+  constructor(array) {
+    super();
+    const trimLeadingDashes =
+      (flag) => StringPrototypeReplace(flag, leadingDashesRegex, '');
+
+    // Save these for comparison against flags provided to
+    // process.allowedNodeEnvironmentFlags.has() which lack leading dashes.
+    const withoutDashes = ArrayPrototypeMap(array,
+                                            trimLeadingDashes);
+    this[kInternal] = { array, withoutDashes };
+  }
+
+  add() {
+    // No-op, `Set` API compatible
+    return this;
+  }
+
+  delete() {
+    // No-op, `Set` API compatible
+    return false;
+  }
+
+  clear() {
+    // No-op, `Set` API compatible
+  }
+
+  has(key) {
+    // This will return `true` based on various possible
+    // permutations of a flag, including present/missing leading
+    // dash(es) and/or underscores-for-dashes.
+    // Strips any values after `=`, inclusive.
+    // TODO(addaleax): It might be more flexible to run the option parser
+    // on a dummy option set and see whether it rejects the argument or
+    // not.
+    if (typeof key === 'string') {
+      key = StringPrototypeReplace(key, replaceUnderscoresRegex, '-');
+      if (RegExpPrototypeTest(leadingDashesRegex, key)) {
+        key = StringPrototypeReplace(key, trailingValuesRegex, '');
+        return ArrayPrototypeIncludes(this[kInternal].array, key);
+      }
+      return ArrayPrototypeIncludes(this[kInternal].withoutDashes, key);
+    }
+    return false;
+  }
+
+  entries() {
+    this[kInternal].set ??=
+      new Set(new SafeArrayIterator(this[kInternal].array));
+    return SetPrototypeEntries(this[kInternal].set);
+  }
+
+  forEach(callback, thisArg = undefined) {
+    ArrayPrototypeForEach(
+      this[kInternal].array,
+      (v) => ReflectApply(callback, thisArg, [v, v, this])
+    );
+  }
+
+  get size() {
+    return this[kInternal].array.length;
+  }
+
+  values() {
+    this[kInternal].set ??=
+      new Set(new SafeArrayIterator(this[kInternal].array));
+    return SetPrototypeValues(this[kInternal].set);
+  }
+}
+FlagsSet.prototype.keys =
+FlagsSet.prototype[SymbolIterator] =
+  FlagsSet.prototype.values;
+
+ObjectFreeze(FlagsSet.prototype.constructor);
+ObjectFreeze(FlagsSet.prototype);
+
 // This builds the initial process.allowedNodeEnvironmentFlags
 // from data in the config binding.
 function buildAllowedFlags() {
@@ -301,88 +378,562 @@ function buildAllowedFlags() {
     }
   }
 
-  const trimLeadingDashes =
-    (flag) => StringPrototypeReplace(flag, leadingDashesRegex, '');
-
-  // Save these for comparison against flags provided to
-  // process.allowedNodeEnvironmentFlags.has() which lack leading dashes.
-  const nodeFlags = ArrayPrototypeMap(allowedNodeEnvironmentFlags,
-                                      trimLeadingDashes);
-
-  class NodeEnvironmentFlagsSet extends Set {
-    constructor(array) {
-      super();
-      this[kInternal] = { array };
-    }
-
-    add() {
-      // No-op, `Set` API compatible
-      return this;
-    }
-
-    delete() {
-      // No-op, `Set` API compatible
-      return false;
-    }
-
-    clear() {
-      // No-op, `Set` API compatible
-    }
-
-    has(key) {
-      // This will return `true` based on various possible
-      // permutations of a flag, including present/missing leading
-      // dash(es) and/or underscores-for-dashes.
-      // Strips any values after `=`, inclusive.
-      // TODO(addaleax): It might be more flexible to run the option parser
-      // on a dummy option set and see whether it rejects the argument or
-      // not.
-      if (typeof key === 'string') {
-        key = StringPrototypeReplace(key, replaceUnderscoresRegex, '-');
-        if (RegExpPrototypeTest(leadingDashesRegex, key)) {
-          key = StringPrototypeReplace(key, trailingValuesRegex, '');
-          return ArrayPrototypeIncludes(this[kInternal].array, key);
-        }
-        return ArrayPrototypeIncludes(nodeFlags, key);
-      }
-      return false;
-    }
-
-    entries() {
-      this[kInternal].set ??=
-        new Set(new SafeArrayIterator(this[kInternal].array));
-      return SetPrototypeEntries(this[kInternal].set);
-    }
-
-    forEach(callback, thisArg = undefined) {
-      ArrayPrototypeForEach(
-        this[kInternal].array,
-        (v) => ReflectApply(callback, thisArg, [v, v, this])
-      );
-    }
-
-    get size() {
-      return this[kInternal].array.length;
-    }
-
-    values() {
-      this[kInternal].set ??=
-        new Set(new SafeArrayIterator(this[kInternal].array));
-      return SetPrototypeValues(this[kInternal].set);
-    }
-  }
-  NodeEnvironmentFlagsSet.prototype.keys =
-  NodeEnvironmentFlagsSet.prototype[SymbolIterator] =
-    NodeEnvironmentFlagsSet.prototype.values;
-
-  ObjectFreeze(NodeEnvironmentFlagsSet.prototype.constructor);
-  ObjectFreeze(NodeEnvironmentFlagsSet.prototype);
-
-  return ObjectFreeze(new NodeEnvironmentFlagsSet(
+  return ObjectFreeze(new FlagsSet(
     allowedNodeEnvironmentFlags
   ));
 }
 
+// This builds the initial process.availableV8Flags.
+function buildAvailableV8Flags() {
+
+  const v8Flags = [
+    '--abort-on-contradictory-flags',
+    '--abort-on-uncaught-exception',
+    '--adjust-os-scheduling-parameters',
+    '--allocation-buffer-parking',
+    '--allocation-site-pretenuring',
+    '--allow-natives-for-differential-fuzzing',
+    '--allow-natives-syntax',
+    '--allow-overwriting-for-next-flag',
+    '--allow-unsafe-function-constructor',
+    '--always-compact',
+    '--always-opt',
+    '--always-osr',
+    '--always-sparkplug',
+    '--analyze-environment-liveness',
+    '--arm-arch',
+    '--asm-wasm-lazy-compilation',
+    '--assert-types',
+    '--async-stack-traces',
+    '--baseline-batch-compilation',
+    '--baseline-batch-compilation-threshold',
+    '--budget-for-feedback-vector-allocation',
+    '--builtin-subclassing',
+    '--builtins-in-stack-traces',
+    '--bytecode-size-allowance-per-tick',
+    '--bytecode-size-allowance-per-tick',
+    '--cache-prototype-transitions',
+    '--clear-exceptions-on-js-entry',
+    '--clear-free-memory',
+    '--compact-code-space',
+    '--compilation-cache',
+    '--concurrent-array-buffer-sweeping',
+    '--concurrent-cache-deserialization',
+    '--concurrent-cache-deserialization',
+    '--concurrent-inlining',
+    '--concurrent-marking',
+    '--concurrent-recompilation',
+    '--concurrent-recompilation-delay',
+    '--concurrent-recompilation-queue-length',
+    '--concurrent-sweeping',
+    '--correctness-fuzzer-suppressions',
+    '--cpu-profiler-sampling-interval',
+    '--crash-on-aborted-evacuation',
+    '--csa-trap-on-node',
+    '--default-to-experimental-regexp-engine',
+    '--deopt-every-n-times',
+    '--detailed-error-stack-trace',
+    '--detailed-line-info',
+    '--detect-ineffective-gcs-near-heap-limit',
+    '--disable-abortjs',
+    '--disable-old-api-accessors',
+    '--disallow-code-generation-from-strings',
+    '--dump-counters',
+    '--dump-counters-nvp',
+    '--dump-wasm-module-path',
+    '--embedded-src',
+    '--embedded-variant',
+    '--embedder-instance-types',
+    '--enable-32dregs',
+    '--enable-armv7',
+    '--enable-armv8',
+    '--enable-avx',
+    '--enable-avx2',
+    '--enable-bmi1',
+    '--enable-bmi2',
+    '--enable-experimental-regexp-engine',
+    '--enable-experimental-regexp-engine-on-excessive-backtracks',
+    '--enable-fma3',
+    '--enable-lazy-source-positions',
+    '--enable-lzcnt',
+    '--enable-mega-dom-ic',
+    '--enable-neon',
+    '--enable-popcnt',
+    '--enable-regexp-unaligned-accesses',
+    '--enable-sahf',
+    '--enable-sharedarraybuffer-per-context',
+    '--enable-source-at-csa-bind',
+    '--enable-sse3',
+    '--enable-sse4-1',
+    '--enable-sse4-2',
+    '--enable-ssse3',
+    '--enable-sudiv',
+    '--enable-system-instrumentation',
+    '--enable-vfp3',
+    '--ephemeron-fixpoint-iterations',
+    '--experimental-flush-embedded-blob-icache',
+    '--experimental-stack-trace-frames',
+    '--experimental-wasm-allow-huge-modules',
+    '--experimental-wasm-branch-hinting',
+    '--experimental-wasm-compilation-hints',
+    '--experimental-wasm-eh',
+    '--experimental-wasm-gc',
+    '--experimental-wasm-memory64',
+    '--experimental-wasm-nn-locals',
+    '--experimental-wasm-reftypes',
+    '--experimental-wasm-relaxed-simd',
+    '--experimental-wasm-return-call',
+    '--experimental-wasm-simd',
+    '--experimental-wasm-stack-switching',
+    '--experimental-wasm-threads',
+    '--experimental-wasm-type-reflection',
+    '--experimental-wasm-typed-funcref',
+    '--experimental-wasm-unsafe-nn-locals',
+    '--expose-async-hooks',
+    '--expose-cputracemark-as',
+    '--expose-externalize-string',
+    '--expose-gc',
+    '--expose-gc-as',
+    '--expose-ignition-statistics',
+    '--expose-inspector-scripts',
+    '--expose-trigger-failure',
+    '--expose-wasm',
+    '--fast-promotion-new-space',
+    '--feedback-allocation-on-bytecode-size',
+    '--feedback-normalization',
+    '--finalize-streaming-on-background',
+    '--flush-baseline-code',
+    '--flush-bytecode',
+    '--force-long-branches',
+    '--force-marking-deque-overflows',
+    '--force-slow-path',
+    '--function-context-specialization',
+    '--future',
+    '--fuzzer-gc-analysis',
+    '--fuzzer-random-seed',
+    '--fuzzing',
+    '--gc-experiment-less-compaction',
+    '--gc-fake-mmap',
+    '--gc-global',
+    '--gc-interval',
+    '--gc-stats',
+    '--global-gc-scheduling',
+    '--hard-abort',
+    '--harmony',
+    '--harmony-array-find-last',
+    '--harmony-atomics',
+    '--harmony-class-static-blocks',
+    '--harmony-error-cause',
+    '--harmony-import-assertions',
+    '--harmony-intl-best-fit-matcher',
+    '--harmony-intl-dateformat-day-period',
+    '--harmony-intl-displaynames-v2',
+    '--harmony-intl-enumeration',
+    '--harmony-intl-locale-info',
+    '--harmony-intl-more-timezone',
+    '--harmony-object-has-own',
+    '--harmony-private-brand-checks',
+    '--harmony-rab-gsab',
+    '--harmony-regexp-sequence',
+    '--harmony-relative-indexing-methods',
+    '--harmony-sharedarraybuffer',
+    '--harmony-shipping',
+    '--harmony-top-level-await',
+    '--harmony-weak-refs-with-cleanup-some',
+    '--hash-seed',
+    '--heap-growing-percent',
+    '--heap-profiler-show-hidden-objects',
+    '--heap-profiler-trace-objects',
+    '--heap-profiler-use-embedder-graph',
+    '--heap-snapshot-string-limit',
+    '--help',
+    '--histogram-interval',
+    '--huge-max-old-generation-size',
+    '--icu-timezone-data',
+    '--ignition-elide-noneffectful-bytecodes',
+    '--ignition-filter-expression-positions',
+    '--ignition-reo',
+    '--ignition-share-named-property-feedback',
+    '--incremental-marking',
+    '--incremental-marking-hard-trigger',
+    '--incremental-marking-soft-trigger',
+    '--incremental-marking-task',
+    '--incremental-marking-wrappers',
+    '--initial-heap-size',
+    '--initial-old-space-size',
+    '--inline-new',
+    '--interpreted-frames-native-stack',
+    '--interrupt-budget',
+    '--interrupt-budget-scale-factor-for-top-tier',
+    '--isolate-script-cache-ageing',
+    '--jitless',
+    '--lazy',
+    '--lazy-compile-dispatcher',
+    '--lazy-eval',
+    '--lazy-feedback-allocation',
+    '--lazy-new-space-shrinking',
+    '--lazy-streaming',
+    '--liftoff',
+    '--liftoff-only',
+    '--lite-mode',
+    '--ll-prof',
+    '--log',
+    '--log-all',
+    '--log-api',
+    '--log-code',
+    '--log-code-disassemble',
+    '--log-colour',
+    '--log-deopt',
+    '--log-function-events',
+    '--log-handles',
+    '--log-ic',
+    '--log-internal-timer-events',
+    '--log-maps',
+    '--log-maps-details',
+    '--log-source-code',
+    '--log-suspect',
+    '--logfile',
+    '--logfile-per-isolate',
+    '--manual-evacuation-candidates-selection',
+    '--map-counters',
+    '--max-bytecode-size-for-early-opt',
+    '--max-heap-size',
+    '--max-inlined-bytecode-size',
+    '--max-inlined-bytecode-size-absolute',
+    '--max-inlined-bytecode-size-cumulative',
+    '--max-inlined-bytecode-size-small',
+    '--max-lazy',
+    '--max-old-space-size',
+    '--max-optimized-bytecode-size',
+    '--max-semi-space-size',
+    '--max-serializer-nesting',
+    '--max-stack-trace-source-length',
+    '--max-valid-polymorphic-map-count',
+    '--mcpu',
+    '--memory-reducer',
+    '--memory-reducer-for-small-heaps',
+    '--min-inlining-frequency',
+    '--min-semi-space-size',
+    '--minor-mc',
+    '--minor-mc-trace-fragmentation',
+    '--mock-arraybuffer-allocator',
+    '--mock-arraybuffer-allocator-limit',
+    '--move-object-start',
+    '--multi-mapped-mock-allocator',
+    '--native-code-counters',
+    '--never-compact',
+    '--opt',
+    '--optimize-for-size',
+    '--page-promotion',
+    '--page-promotion-threshold',
+    '--parallel-compaction',
+    '--parallel-compile-tasks',
+    '--parallel-marking',
+    '--parallel-pointer-update',
+    '--parallel-scavenge',
+    '--parse-only',
+    '--partial-constant-pool',
+    '--perf-basic-prof',
+    '--perf-basic-prof-only-functions',
+    '--perf-prof',
+    '--perf-prof-annotate-wasm',
+    '--perf-prof-delete-file',
+    '--perf-prof-unwinding-info',
+    '--polymorphic-inlining',
+    '--predictable',
+    '--predictable-gc-schedule',
+    '--prepare-always-opt',
+    '--print-all-code',
+    '--print-all-exceptions',
+    '--print-builtin-code',
+    '--print-builtin-code-filter',
+    '--print-builtin-size',
+    '--print-bytecode',
+    '--print-bytecode-filter',
+    '--print-code',
+    '--print-code-verbose',
+    '--print-deopt-stress',
+    '--print-opt-code',
+    '--print-opt-code-filter',
+    '--print-opt-source',
+    '--print-regexp-bytecode',
+    '--print-regexp-code',
+    '--print-wasm-code',
+    '--print-wasm-code-function-index',
+    '--print-wasm-stub-code',
+    '--prof',
+    '--prof-browser-mode',
+    '--prof-cpp',
+    '--prof-sampling-interval',
+    '--profile-deserialization',
+    '--random-gc-interval',
+    '--random-seed',
+    '--randomize-all-allocations',
+    '--randomize-hashes',
+    '--rcs',
+    '--rcs-cpu-time',
+    '--reclaim-unmodified-wrappers',
+    '--redirect-code-traces',
+    '--redirect-code-traces-to',
+    '--regexp-backtracks-before-fallback',
+    '--regexp-interpret-all',
+    '--regexp-optimization',
+    '--regexp-peephole-optimization',
+    '--regexp-tier-up',
+    '--regexp-tier-up-ticks',
+    '--rehash-snapshot',
+    '--reserve-inline-budget-scale-factor',
+    '--retain-maps-for-n-gc',
+    '--reuse-opt-code-count',
+    '--runtime-call-stats',
+    '--sampling-heap-profiler-suppress-randomness',
+    '--scale-factor-for-feedback-allocation',
+    '--scavenge-separate-stack-scanning',
+    '--scavenge-task',
+    '--scavenge-task-trigger',
+    '--script-delay',
+    '--script-delay-fraction',
+    '--script-delay-once',
+    '--script-streaming',
+    '--semi-space-growth-factor',
+    '--serialization-statistics',
+    '--sim-arm64-optional-features',
+    '--single-threaded',
+    '--single-threaded-gc',
+    '--skip-snapshot-checksum',
+    '--slow-histograms',
+    '--sparkplug',
+    '--sparkplug-filter',
+    '--sparkplug-needs-short-builtins',
+    '--sparkplug-on-heap',
+    '--stack-size',
+    '--stack-trace-limit',
+    '--stack-trace-on-illegal',
+    '--startup-blob',
+    '--startup-src',
+    '--stress-background-compile',
+    '--stress-compaction',
+    '--stress-compaction-random',
+    '--stress-concurrent-allocation',
+    '--stress-concurrent-inlining',
+    '--stress-concurrent-inlining-attach-code',
+    '--stress-flush-code',
+    '--stress-gc-during-compilation',
+    '--stress-incremental-marking',
+    '--stress-inline',
+    '--stress-lazy-source-positions',
+    '--stress-marking',
+    '--stress-per-context-marking-worklist',
+    '--stress-runs',
+    '--stress-sampling-allocation-profiler',
+    '--stress-scavenge',
+    '--stress-snapshot',
+    '--stress-turbo-late-spilling',
+    '--stress-validate-asm',
+    '--stress-wasm-code-gc',
+    '--super-ic',
+    '--suppress-asm-messages',
+    '--switch-table-min-cases',
+    '--switch-table-spread-threshold',
+    '--target-arch',
+    '--target-is-simulator',
+    '--target-os',
+    '--test-small-max-function-context-stub-size',
+    '--testing-bool-flag',
+    '--testing-d8-test-runner',
+    '--testing-float-flag',
+    '--testing-int-flag',
+    '--testing-maybe-bool-flag',
+    '--testing-prng-seed',
+    '--testing-string-flag',
+    '--text-is-readable',
+    '--ticks-before-optimization',
+    '--trace',
+    '--trace-all-uses',
+    '--trace-allocation-stack-interval',
+    '--trace-allocations-origins',
+    '--trace-asm-parser',
+    '--trace-asm-scanner',
+    '--trace-asm-time',
+    '--trace-baseline',
+    '--trace-baseline-batch-compilation',
+    '--trace-block-coverage',
+    '--trace-compilation-dependencies',
+    '--trace-compiler-dispatcher',
+    '--trace-concurrent-marking',
+    '--trace-concurrent-recompilation',
+    '--trace-creation-allocation-sites',
+    '--trace-deopt',
+    '--trace-deopt-verbose',
+    '--trace-detached-contexts',
+    '--trace-duplicate-threshold-kb',
+    '--trace-elements-transitions',
+    '--trace-environment-liveness',
+    '--trace-evacuation',
+    '--trace-evacuation-candidates',
+    '--trace-experimental-regexp-engine',
+    '--trace-file-names',
+    '--trace-flush-bytecode',
+    '--trace-for-in-enumerate',
+    '--trace-fragmentation',
+    '--trace-fragmentation-verbose',
+    '--trace-gc',
+    '--trace-gc-freelists',
+    '--trace-gc-freelists-verbose',
+    '--trace-gc-ignore-scavenger',
+    '--trace-gc-nvp',
+    '--trace-gc-object-stats',
+    '--trace-gc-verbose',
+    '--trace-generalization',
+    '--trace-heap-broker',
+    '--trace-heap-broker-memory',
+    '--trace-heap-broker-verbose',
+    '--trace-idle-notification',
+    '--trace-idle-notification-verbose',
+    '--trace-ignition-codegen',
+    '--trace-ignition-dispatches-output-file',
+    '--trace-incremental-marking',
+    '--trace-migration',
+    '--trace-minor-mc-parallel-marking',
+    '--trace-mutator-utilization',
+    '--trace-opt',
+    '--trace-opt-stats',
+    '--trace-opt-verbose',
+    '--trace-osr',
+    '--trace-parallel-scavenge',
+    '--trace-pending-allocations',
+    '--trace-pretenuring',
+    '--trace-pretenuring-statistics',
+    '--trace-protector-invalidation',
+    '--trace-prototype-users',
+    '--trace-rail',
+    '--trace-regexp-assembler',
+    '--trace-regexp-bytecodes',
+    '--trace-regexp-graph',
+    '--trace-regexp-parser',
+    '--trace-regexp-peephole-optimization',
+    '--trace-regexp-tier-up',
+    '--trace-representation',
+    '--trace-serializer',
+    '--trace-side-effect-free-debug-evaluate',
+    '--trace-store-elimination',
+    '--trace-stress-marking',
+    '--trace-stress-scavenge',
+    '--trace-track-allocation-sites',
+    '--trace-turbo',
+    '--trace-turbo-alloc',
+    '--trace-turbo-ceq',
+    '--trace-turbo-cfg-file',
+    '--trace-turbo-filter',
+    '--trace-turbo-graph',
+    '--trace-turbo-inlining',
+    '--trace-turbo-jt',
+    '--trace-turbo-load-elimination',
+    '--trace-turbo-loop',
+    '--trace-turbo-path',
+    '--trace-turbo-reduction',
+    '--trace-turbo-scheduled',
+    '--trace-turbo-scheduler',
+    '--trace-turbo-stack-accesses',
+    '--trace-turbo-trimming',
+    '--trace-turbo-types',
+    '--trace-unmapper',
+    '--trace-verify-csa',
+    '--trace-wasm',
+    '--trace-wasm-code-gc',
+    '--trace-wasm-memory',
+    '--trace-web-snapshot',
+    '--trace-zone-stats',
+    '--trace-zone-type-stats',
+    '--track-detached-contexts',
+    '--track-field-types',
+    '--track-gc-object-stats',
+    '--track-retaining-path',
+    '--turbo-allocation-folding',
+    '--turbo-cf-optimization',
+    '--turbo-collect-feedback-in-generic-lowering',
+    '--turbo-compress-translation-arrays',
+    '--turbo-dynamic-map-checks',
+    '--turbo-escape',
+    '--turbo-fast-api-calls',
+    '--turbo-filter',
+    '--turbo-inline-array-builtins',
+    '--turbo-inline-js-wasm-calls',
+    '--turbo-inlining',
+    '--turbo-instruction-scheduling',
+    '--turbo-jt',
+    '--turbo-load-elimination',
+    '--turbo-loop-peeling',
+    '--turbo-loop-rotation',
+    '--turbo-loop-variable',
+    '--turbo-move-optimization',
+    '--turbo-optimize-apply',
+    '--turbo-profiling',
+    '--turbo-profiling-log-builtins',
+    '--turbo-profiling-log-file',
+    '--turbo-profiling-verbose',
+    '--turbo-rewrite-far-jumps',
+    '--turbo-sp-frame-access',
+    '--turbo-splitting',
+    '--turbo-stats',
+    '--turbo-stats-nvp',
+    '--turbo-stats-wasm',
+    '--turbo-store-elimination',
+    '--turbo-stress-instruction-scheduling',
+    '--turbo-verify',
+    '--turbo-verify-allocation',
+    '--turbo-verify-machine-graph',
+    '--turboprop',
+    '--turboprop-as-toptier',
+    '--turboprop-inline-scaling-factor',
+    '--turboprop-mid-tier-reg-alloc',
+    '--unbox-double-arrays',
+    '--use-external-strings',
+    '--use-ic',
+    '--use-idle-notification',
+    '--use-marking-progress-bar',
+    '--use-osr',
+    '--use-strict',
+    '--v8-os-page-size',
+    '--validate-asm',
+    '--vtune-prof-annotate-wasm',
+    '--wasm-async-compilation',
+    '--wasm-bounds-checks',
+    '--wasm-code-gc',
+    '--wasm-debug-mask-for-testing',
+    '--wasm-dynamic-tiering',
+    '--wasm-enforce-bounds-checks',
+    '--wasm-fuzzer-gen-test',
+    '--wasm-gc-js-interop',
+    '--wasm-generic-wrapper',
+    '--wasm-inlining',
+    '--wasm-lazy-compilation',
+    '--wasm-lazy-validation',
+    '--wasm-loop-unrolling',
+    '--wasm-math-intrinsics',
+    '--wasm-max-code-space',
+    '--wasm-max-initial-code-space-reservation',
+    '--wasm-max-mem-pages',
+    '--wasm-max-table-size',
+    '--wasm-memory-protection-keys',
+    '--wasm-num-compilation-tasks',
+    '--wasm-opt',
+    '--wasm-simd-ssse3-codegen',
+    '--wasm-stack-checks',
+    '--wasm-staging',
+    '--wasm-test-streaming',
+    '--wasm-tier-mask-for-testing',
+    '--wasm-tier-up',
+    '--wasm-write-protect-code-memory',
+    '--win64-unwinding-info',
+    '--write-code-using-rwx',
+    '--write-protect-code-memory',
+    '--zone-stats-tolerance',
+  ];
+
+  return ObjectFreeze(new FlagsSet(v8Flags));
+}
+
 // Lazy load internal/trace_events_async_hooks only if the async_hooks
 // trace event category is enabled.
 let traceEventsAsyncHook;
@@ -400,11 +951,12 @@ function toggleTraceCategoryState(asyncHooksEnabled) {
 }
 
 module.exports = {
-  toggleTraceCategoryState,
   assert,
   buildAllowedFlags,
-  wrapProcessMethods,
+  buildAvailableV8Flags,
   hrtime,
   hrtimeBigInt,
   refreshHrtimeBuffer,
+  toggleTraceCategoryState,
+  wrapProcessMethods,
 };
diff --git a/test/parallel/test-process-available-v8-flags.js b/test/parallel/test-process-available-v8-flags.js
new file mode 100644
index 00000000000000..a0901fb2d29de8
--- /dev/null
+++ b/test/parallel/test-process-available-v8-flags.js
@@ -0,0 +1,111 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const { spawn } = require('child_process');
+
+// Assert legit flags are allowed, and bogus flags are disallowed
+{
+  const goodFlags = [
+    '--single_threaded_gc',
+    '--single-threaded-gc',
+    'single-threaded-gc',
+    '--single_threaded-gc',
+    'single_threaded-gc',
+    '--interrupt-budget=100',
+    '--interrupt-budget=-=xX_nodejs_Xx=-',
+  ];
+
+  const badFlags = [
+    'SINGLE-THREADED-GC',
+    '--SINGLE-THREADED-GC',
+    '--cheeseburgers',
+  ];
+
+  goodFlags.forEach((flag) => {
+    assert.strictEqual(
+      process.availableV8Flags.has(flag),
+      true,
+      `flag should be in set: ${flag}`
+    );
+  });
+
+  badFlags.forEach((flag) => {
+    assert.strictEqual(
+      process.availableV8Flags.has(flag),
+      false,
+      `flag should not be in set: ${flag}`
+    );
+  });
+}
+
+// Assert all flags begin with dashes
+{
+  process.availableV8Flags.forEach((flag) => {
+    assert.match(flag, /^--[a-zA-Z0-9._-]+$/);
+  });
+}
+
+// Assert immutability of process.availableV8Flags
+{
+  assert.strictEqual(Object.isFrozen(process.availableV8Flags),
+                     true);
+
+  process.availableV8Flags.add('foo');
+  assert.strictEqual(process.availableV8Flags.has('foo'), false);
+  Set.prototype.add.call(process.availableV8Flags, 'foo');
+  assert.strictEqual(process.availableV8Flags.has('foo'), false);
+
+  const thisArg = {};
+  process.availableV8Flags.forEach(
+    common.mustCallAtLeast(function(flag, _, set) {
+      assert.notStrictEqual(flag, 'foo');
+      assert.strictEqual(this, thisArg);
+      assert.strictEqual(set, process.availableV8Flags);
+    }),
+    thisArg
+  );
+
+  for (const flag of process.availableV8Flags.keys()) {
+    assert.notStrictEqual(flag, 'foo');
+  }
+  for (const flag of process.availableV8Flags.values()) {
+    assert.notStrictEqual(flag, 'foo');
+  }
+  for (const flag of process.availableV8Flags) {
+    assert.notStrictEqual(flag, 'foo');
+  }
+  for (const [flag] of process.availableV8Flags.entries()) {
+    assert.notStrictEqual(flag, 'foo');
+  }
+
+  const size = process.availableV8Flags.size;
+
+  process.availableV8Flags.clear();
+  assert.strictEqual(process.availableV8Flags.size, size);
+  Set.prototype.clear.call(process.availableV8Flags);
+  assert.strictEqual(process.availableV8Flags.size, size);
+
+  process.availableV8Flags.delete('--single_threaded_gc');
+  assert.strictEqual(process.availableV8Flags.size, size);
+  Set.prototype.delete.call(process.availableV8Flags, '--single_threaded_gc');
+  assert.strictEqual(process.availableV8Flags.size, size);
+}
+
+// Output of `node --v8-options` should match contents of availableV8Flags.
+{
+  let result = '';
+  const command = spawn(process.execPath, ['--v8-options']);
+  command.stdout.on('data', common.mustCallAtLeast((data) => {
+    result += data.toString();
+  }));
+  command.on('close', common.mustCall((code) => {
+    assert.strictEqual(code, 0);
+    result = result.replace(/^.*Options:/s, '');
+    const cliOptions = [...result.matchAll(/^ {2}(--[^ ]+)/gm)]
+      .map((m) => m[1])
+      .sort();
+    const v8Options = [...process.availableV8Flags.values()].sort();
+    assert.deepStrictEqual(v8Options, cliOptions);
+  }));
+}