#!/usr/bin/env python3
"""Check only tuplerepeat's dest declaration and allocation-time assignment."""
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"tuplerepeat\(PyTupleObject \*a, Py_ssize_t n\)\n\{(.*?)\n\}",
    source.read_text(),
    re.S,
)
assert match, "tuplerepeat definition missing"
body = match.group(1)
assert re.match(
    r"\s*Py_ssize_t size;\s*PyTupleObject \*np;\s*PyObject \*\*dest;"
    r"\s*PyObject \*\*dest_end;\s*if",
    body,
), "tuplerepeat: dest must be declared in the opening declaration block"
assert len(re.findall(r"PyObject\s*\*\*dest\b", body)) == 1, (
    "tuplerepeat: exactly one uninitialized dest declaration required"
)
assert re.search(
    r"np = tuple_alloc\(size\);\s*if \(np == NULL\)\s*return NULL;"
    r"\s*dest = np->ob_item;\s*dest_end = dest \+ size;",
    body,
), "tuplerepeat: assign dest immediately after allocation/NULL check, before unchanged dest_end"
assert len(re.findall(r"\bdest\s*=", body)) == 1, (
    "tuplerepeat: exactly one dest assignment required"
)
print("tuplerepeat dest C89 declaration and allocation/assignment order: PASS")