#!/usr/bin/env python3
"""Regress the probe's C2143 at the MRO population loop initializer."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic PyObject \*\nmro_implementation\(PyTypeObject \*type\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "mro_implementation definition missing"
body = match.group(1)
declarations = body.split("if (!_PyType_IsReady(type))", 1)[0]
assert re.search(r"\bPy_ssize_t i;", declarations), "function-scope i missing"
population = body.split("to_merge = PyMem_New(PyObject *, n + 1);", 1)[1]
loop = re.search(r"\bfor\s*\((.*?)\)\s*\{(.*?)\n    \}", population, re.S)
assert loop, "to_merge population loop missing"
assert loop.group(1).split() == "i = 0; i < n; i++".split(), (
    "C2143 regression: to_merge population loop must reuse existing i: "
    "for (i = 0; i < n; i++)"
)
assert loop.group(2).split() == """
    PyTypeObject *base = _PyType_CAST(PyTuple_GET_ITEM(bases, i));
    to_merge[i] = base->tp_mro;
""".split(), "preserve population loop behavior"
print("mro_implementation population index C2143 regression: PASS")