#!/usr/bin/env python3
"""Statically check type_new ctx declaration and post-parse initialization."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
function = re.search(
    r"\ntype_new\(PyTypeObject \*metatype, PyObject \*args, PyObject \*kwds\)\n\{(.*?)\n\}",
    source, re.S,
)
assert function, "type_new definition must exist"
body = function.group(1)
opening = re.match(
    r"\s*PyObject \*name, \*bases, \*orig_dict;\s*type_new_ctx ctx;\s*"
    r"PyObject \*type;\s*int res;\s*(?=assert\()",
    body,
)
assert opening, "type_new: type_new_ctx ctx must be in the opening declaration block"
assert len(re.findall(r"\btype_new_ctx\s+ctx\b", body)) == 1
expected_setup = """
    memset(&ctx, 0, sizeof(ctx));
    ctx.metatype = metatype;
    ctx.args = args;
    ctx.kwds = kwds;
    ctx.orig_dict = orig_dict;
    ctx.name = name;
    ctx.bases = bases;
"""
expected_parse = """
    assert(args != NULL && PyTuple_Check(args));
    assert(kwds == NULL || PyDict_Check(kwds));

    /* Parse arguments: (name, bases, dict) */
    if (!PyArg_ParseTuple(args, "UO!O!:type.__new__",
                          &name,
                          &PyTuple_Type, &bases,
                          &PyDict_Type, &orig_dict))
    {
        return NULL;
    }
"""
prefix, separator, tail = body[opening.end():].partition("type = NULL;")
assert separator, "base-resolution frontier must remain"
assert prefix.split() == (expected_parse + expected_setup).split(), (
    "preserve parsing and failure return, then zero all ctx fields and assign inputs"
)
assert tail.lstrip().startswith("res = type_new_get_bases(&ctx, &type);"), (
    "base resolution must still follow ctx setup"
)
assert "(type_new_ctx)" not in body, "no C99 compound literal"
assert "#  include <string.h>" in Path("cpython/Include/Python.h").read_text()
print("type_new ctx opening declaration and post-parse zero/field setup: PASS (static only)")