ffi: function .pointer is lost when Function.prototype.pointer is non-writable #67169

Version

main

Platform

macOS

Subsystem

ffi

What steps will reproduce the bug?

import { DynamicLibrary } from 'node:ffi';

Object.defineProperty(Function.prototype, 'pointer', {
  value: 1, writable: false, configurable: true,
});

const lib = new DynamicLibrary(null);
const abs = lib.getFunction('abs', { arguments: ['i32'], return: 'i32' });
console.log(abs.pointer);
console.log(abs(-5));

How often does it reproduce? Is there a required condition?

Always, as long as Function.prototype.pointer is non-writable before the function is created.
Functions returned by ffi.dlopen() and library.getFunctions() are affected the same way.

What is the expected behavior? Why is that the expected behavior?

6669613580n
5

The docs say the returned function "has a .pointer property containing the native function address as a bigint".
https://github.com/nodejs/node/blob/main/doc/api/ffi.md#librarygetfunctionname-signature

What do you see instead?

1
5

On the returned function, pointer is an own, writable data property with the value 1. The real address is never stored on it.

Additional information

No response