#!/usr/bin/env python3
"""Check only the late bases declaration in assign_version_tag near MRO code."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic int\nassign_version_tag\(struct type_cache \*cache, PyTypeObject \*type\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "assign_version_tag definition missing"
body = re.sub(r"/\*.*?\*/", "", match.group(1), flags=re.S)
assert re.match(r"\s*PyObject \*bases;", body), (
    "assign_version_tag: PyObject *bases; must be in the opening declarations"
)
assert len(re.findall(r"\bPyObject\s*\*\s*bases\b", body)) == 1, (
    "assign_version_tag: declare bases exactly once"
)
expected = """
    PyObject *bases;
    Py_ssize_t n;
    Py_ssize_t i;
    if (_PyType_HasFeature(type, Py_TPFLAGS_VALID_VERSION_TAG)) {
        return 1;
    }
    if (!_PyType_HasFeature(type, Py_TPFLAGS_READY)) {
        return 0;
    }
    if (next_version_tag == 0) {
        return 0;
    }
    type->tp_version_tag = next_version_tag++;
    assert (type->tp_version_tag != 0);
    bases = type->tp_bases;
    n = PyTuple_GET_SIZE(bases);
    for (i = 0; i < n; i++) {
        PyObject *b = PyTuple_GET_ITEM(bases, i);
        if (!assign_version_tag(cache, _PyType_CAST(b)))
            return 0;
    }
    type->tp_flags |= Py_TPFLAGS_VALID_VERSION_TAG;
    return 1;
"""
assert body.split() == expected.split(), (
    "assign_version_tag: preserve bases read timing, guards, n, and loop index"
)
print("assign_version_tag bases C89 declaration and unchanged evaluation order: PASS")