#!/usr/bin/env python3
"""Keep type_vectorcall tstate C89-safe and its lookup on the fallback path."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic PyObject \*\ntype_vectorcall\(PyObject \*metatype, PyObject \*const \*args,\n"
    r"\s*size_t nargsf, PyObject \*kwnames\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_vectorcall definition missing"
body = match.group(1)
assert re.match(
    r"\s*Py_ssize_t nargs;\s*PyThreadState \*tstate;"
    r"\s*nargs = PyVectorcall_NARGS\(nargsf\);",
    body,
), "type_vectorcall: tstate must precede statements in the opening declaration block (C89)"
expected = """
    Py_ssize_t nargs;
    PyThreadState *tstate;

    nargs = PyVectorcall_NARGS(nargsf);
    if (nargs == 1 && metatype == (PyObject *)&PyType_Type){
        if (!_PyArg_NoKwnames("type", kwnames)) {
            return NULL;
        }
        return Py_NewRef(Py_TYPE(args[0]));
    }
    /* In other (much less common) cases, fall back to
       more flexible calling conventions. */
    tstate = _PyThreadState_GET();
    return _PyObject_MakeTpCall(tstate, metatype, args, nargs, kwnames);
"""
assert body.split() == expected.split(), (
    "type_vectorcall: preserve fallback-only tstate assignment, evaluation order, and control flow"
)
print("type_vectorcall tstate C89 declaration and same-point fallback assignment: PASS")