tests/readlink.py

rust-cpython: allow mutation unless leaked reference is borrowed

In other words, mutation is allowed while a Python iterator holding PyLeaked
exists. The iterator will be invalidated instead.

We still need a borrow_count to prevent mutation while leaked data is
dereferenced in Rust world, but most leak_count business is superseded by
the generation counter.

decrease_leak_count(py, true) will be removed soon.

#!/usr/bin/env python

from __future__ import absolute_import, print_function

import errno
import os
import sys

for f in sys.argv[1:]:
    try:
        print(f, '->', os.readlink(f))
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print(f, '->', f, 'not a symlink')

sys.exit(0)