#!/usr/bin/env python3
"""Keep type_call's nargs declaration C89-safe and its evaluation after asserts."""
import re
import sys
from pathlib import Path

source = Path(sys.argv[1] if len(sys.argv) > 1 else "cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic PyObject \*\ntype_call\(PyTypeObject \*type, PyObject \*args, PyObject \*kwds\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_call definition missing"
body = match.group(1)
assert re.search(r"if \(type == &PyType_Type\) \{\s*Py_ssize_t nargs;", body), (
    "type_call: nargs must be declared at block entry before assertions (C89)"
)
assert len(re.findall(r"\bPy_ssize_t\s+nargs\b", body)) == 1, (
    "type_call: declare nargs exactly once"
)
expected = """
    if (type == &PyType_Type) {
        Py_ssize_t nargs;
        assert(args != NULL && PyTuple_Check(args));
        assert(kwds == NULL || PyDict_Check(kwds));
        nargs = PyTuple_GET_SIZE(args);

        if (nargs == 1 && (kwds == NULL || !PyDict_GET_SIZE(kwds))) {
            obj = (PyObject *) Py_TYPE(PyTuple_GET_ITEM(args, 0));
            Py_INCREF(obj);
            return obj;
        }

        /* SF bug 475327 -- if that didn't trigger, we need 3
           arguments. But PyArg_ParseTuple in type_new may give
           a msg saying type() needs exactly 3. */
        if (nargs != 3) {
            PyErr_SetString(PyExc_TypeError,
                            "type() takes 1 or 3 arguments");
            return NULL;
        }
    }
"""
special_case = body[body.index("    if (type == &PyType_Type)"):body.index("    if (type->tp_new == NULL)")]
assert special_case.split() == expected.split(), (
    "type_call: preserve nargs assignment after assertions and special-case control flow"
)
assert re.findall(r"\bnargs\s*=(?!=)\s*([^;]+);", body) == ["PyTuple_GET_SIZE(args)"], (
    "type_call: evaluate nargs exactly once"
)
print("type_call nargs C89 declaration and unchanged evaluation/control flow: PASS")