#!/usr/bin/env python3
"""Check set_vectorcall's C89 declaration and unchanged evaluation order."""
import re
import sys
from pathlib import Path

source = Path(sys.argv[1]).read_text()
match = re.search(
    r"static PyObject\*\nset_vectorcall\(PyObject \*type, PyObject \* const\*args,"
    r"\s*size_t nargsf, PyObject \*kwnames\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "set_vectorcall not found"
body = match.group(1)
assert re.match(r"\s*Py_ssize_t nargs;", body), (
    "set_vectorcall: nargs must be declared without an initializer before "
    "assert(PyType_Check(type)); late declaration is not C89 compatible"
)
expected = """
    Py_ssize_t nargs;

    assert(PyType_Check(type));

    if (!_PyArg_NoKwnames("set", kwnames)) {
        return NULL;
    }

    nargs = PyVectorcall_NARGS(nargsf);
    if (!_PyArg_CheckPositional("set", nargs, 0, 1)) {
        return NULL;
    }

    if (nargs) {
        return make_new_set(_PyType_CAST(type), args[0]);
    }

    return make_new_set(_PyType_CAST(type), NULL);
"""
assert re.sub(r"\s+", "", body) == re.sub(r"\s+", "", expected), (
    "preserve type assertion, keyword rejection, nargs evaluation, positional "
    "rejection, guarded args[0] access, and construction in their original order"
)
print("set_vectorcall C89 declaration and evaluation order: PASS")