#!/usr/bin/env python3
"""Check only _PyTuple_FromArraySteal's allocation-failure and success loop C89 fixes."""
import re
import sys
from pathlib import Path

source = Path(sys.argv[1] if len(sys.argv) > 1 else "cpython/Objects/tupleobject.c")
match = re.search(
    r"PyObject \*\n_PyTuple_FromArraySteal\(PyObject \*const \*src, Py_ssize_t n\)\n\{(.*?)\n\}",
    source.read_text(),
    re.S,
)
assert match, "_PyTuple_FromArraySteal definition not found"
body = match.group(1)
assert re.match(
    r"\s*PyTupleObject \*tuple;\s*Py_ssize_t i;\s*PyObject \*\*dst;\s*if \(n == 0\)", body
), "_PyTuple_FromArraySteal: function-scope Py_ssize_t i must precede statements"
assert "for (Py_ssize_t i =" not in body, (
    "_PyTuple_FromArraySteal: success loop must reuse function-scope i with assignment"
)
expected = """
    PyTupleObject *tuple;
    Py_ssize_t i;
    PyObject **dst;
    if (n == 0) {
        return tuple_get_empty();
    }
    tuple = tuple_alloc(n);
    if (tuple == NULL) {
        for (i = 0; i < n; i++) {
            Py_DECREF(src[i]);
        }
        return NULL;
    }
    dst = tuple->ob_item;
    for (i = 0; i < n; i++) {
        PyObject *item = src[i];
        dst[i] = item;
    }
    _PyObject_GC_TRACK(tuple);
    return (PyObject *)tuple;
"""
assert re.sub(r"\s+", "", body) == re.sub(r"\s+", "", expected), (
    "preserve empty return/allocation/NULL check, failure loop initialization, "
    "condition, increment, DECREF and NULL return order; retain later "
    "dst/item declarations and success-loop initialization/condition/increment/order"
)
print("_PyTuple_FromArraySteal failure/success C89 loops and evaluation/DECREF/return order: PASS")