#!/usr/bin/env python3
"""Check type_new_classmethod's C89 declaration and guarded allocation."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic int\ntype_new_classmethod\(PyTypeObject \*type, PyObject \*attr\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_new_classmethod definition missing"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", match.group(1), flags=re.S)
assert re.match(
    r"\s*PyObject \*method;"
    r"\s*PyObject \*func = PyDict_GetItemWithError\(type->tp_dict, attr\);",
    body,
), "type_new_classmethod: method must be in the opening declaration block (C89)"
expected = """
    PyObject *method;
    PyObject *func = PyDict_GetItemWithError(type->tp_dict, attr);
    if (func == NULL) {
        if (PyErr_Occurred()) {
            return -1;
        }
        return 0;
    }
    if (!PyFunction_Check(func)) {
        return 0;
    }

    method = PyClassMethod_New(func);
    if (method == NULL) {
        return -1;
    }
    if (PyDict_SetItem(type->tp_dict, attr, method) < 0) {
        Py_DECREF(method);
        return -1;
    }
    Py_DECREF(method);
    return 0;
"""
assert body.split() == expected.split(), (
    "type_new_classmethod: preserve lookup, guards, allocation timing, "
    "dictionary insertion, decrefs, and returns"
)
print("type_new_classmethod method C89 declaration and guarded allocation: PASS")