#!/usr/bin/env python3
"""Check tupledealloc's C89 declaration and exact teardown evaluation order."""
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"static void\ntupledealloc\(PyTupleObject \*op\)\n\{(.*?)\n\}",
    source.read_text(),
    re.S,
)
assert match, "tupledealloc definition not found"
body = match.group(1)
assert re.match(r"\s*Py_ssize_t i;", body), (
    "tupledealloc: i must be declared without initializer before the empty "
    "tuple check; declaration after Py_TRASHCAN_BEGIN is not C89 compatible"
)
expected = """
    Py_ssize_t i;
    if (Py_SIZE(op) == 0) {
        /* The empty tuple is statically allocated. */
        if (op == &_Py_SINGLETON(tuple_empty)) {
#ifdef Py_DEBUG
            _Py_FatalRefcountError("deallocating the empty tuple singleton");
#else
            return;
#endif
        }
#ifdef Py_DEBUG
        /* tuple subclasses have their own empty instances. */
        assert(!PyTuple_CheckExact(op));
#endif
    }

    PyObject_GC_UnTrack(op);
    Py_TRASHCAN_BEGIN(op, tupledealloc)

    i = Py_SIZE(op);
    while (--i >= 0) {
        Py_XDECREF(op->ob_item[i]);
    }
    // This will abort on the empty singleton (if there is one).
    if (!maybe_freelist_push(op)) {
        Py_TYPE(op)->tp_free((PyObject *)op);
    }

    Py_TRASHCAN_END
"""
assert re.sub(r"\s+", "", body) == re.sub(r"\s+", "", expected), (
    "preserve empty-tuple guards, GC untracking, size assignment immediately "
    "after trashcan entry, reverse item decrefs, freelist/free, and trashcan exit"
)
print("tupledealloc C89 declaration and exact teardown evaluation order: PASS")