#!/usr/bin/env python3
"""Check PyStructSequence_New's C89 declaration and size lookup order."""
import re
import sys
from pathlib import Path

source = Path(sys.argv[1] if len(sys.argv) > 1 else "cpython/Objects/structseq.c")
match = re.search(
    r"PyStructSequence_New\(PyTypeObject \*type\)\s*\{(.*?)\n\}",
    source.read_text(),
    re.S,
)
assert match, "PyStructSequence_New definition not found"
body = match.group(1)
assert re.match(
    r"\s*PyStructSequence \*obj;"
    r"\s*Py_ssize_t size = REAL_SIZE_TP\(type\), i;"
    r"\s*Py_ssize_t vsize;",
    body,
), "vsize must be declared without initializer before the size < 0 check"
assert re.match(
    r"\s*PyStructSequence \*obj;"
    r"\s*Py_ssize_t size = REAL_SIZE_TP\(type\), i;"
    r"\s*Py_ssize_t vsize;"
    r"\s*if \(size < 0\) \{\s*return NULL;\s*\}"
    r"\s*vsize = VISIBLE_SIZE_TP\(type\);"
    r"\s*if \(vsize < 0\) \{\s*return NULL;\s*\}"
    r"\s*obj = PyObject_GC_NewVar\(PyStructSequence, type, size\);",
    body,
), "preserve size early return, visible-size lookup, and allocation order"
assert body.count("VISIBLE_SIZE_TP(type)") == 1, "visible size must be read exactly once"
assert body.count("Py_ssize_t vsize;") == 1, "vsize must be declared exactly once"
print("PyStructSequence_New C89 declaration and size lookup order: PASS")