Function fixBytecode

lib/index.js:324–354

(bytecodeBuffer)

// TODO: rewrite this function
const fixBytecode = function (bytecodeBuffer) {
  if (!isBuffer(bytecodeBuffer)) {
    throw new Error('bytecodeBuffer must be a buffer object.');
  }

  const dummyBytecode = compileCode('"ಠ_ಠ"');
  const version = parseFloat(process.version.slice(1, 5));

  if (process.version.startsWith('v8.8') || process.version.startsWith('v8.9')) {
    // Node is v8.8.x or v8.9.x
    if (DEBUG) console.error('[bytenode] fixBytecode branch: legacy v8.8/v8.9 (patch 16-20, 20-24)');
    dummyBytecode.subarray(16, 20).copy(bytecodeBuffer, 16);
    dummyBytecode.subarray(20, 24).copy(bytecodeBuffer, 20);
  } else if (version >= 12) {
    // Node >= 12 (modern V8 layout). Only the flag hash (offset 12) is patched.
    //
    // The previous upper bound (`version <= 23`) accidentally pushed Node 24+ into the
    // legacy branch below, which ALSO overwrites bytes 16-20 (the read-only snapshot
    // checksum) with the runtime dummy's value. On Electron 42 / V8 14.8 that masks a
    // real checksum mismatch and makes V8 hard-abort (SIGTRAP) inside vm.Script instead
    // of cleanly reporting cachedDataRejected. Patching only the flag hash is the safe,
    // version-stable behavior shared with Node 12-23.
    if (DEBUG) console.error('[bytenode] fixBytecode branch: modern node>=12 (patch flag hash 12-16 only)');
    dummyBytecode.subarray(12, 16).copy(bytecodeBuffer, 12);
  } else {
    // Node 9/10/11 (older header layout).
    if (DEBUG) console.error('[bytenode] fixBytecode branch: node 9/10/11 (patch 12-16, 16-20)');
    dummyBytecode.subarray(12, 16).copy(bytecodeBuffer, 12);
    dummyBytecode.subarray(16, 20).copy(bytecodeBuffer, 16);
  }
};

// TODO: rewrite this function
const readSourceHash = function (bytecodeBuffer) {