#!/usr/bin/env python3
"""Check type_new_alloc's C89 heap-type declaration and cast timing."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic PyTypeObject\*\ntype_new_alloc\(type_new_ctx \*ctx\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_new_alloc definition missing"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", match.group(1), flags=re.S)
assert re.match(
    r"\s*PyTypeObject \*metatype = ctx->metatype;"
    r"\s*PyTypeObject \*type;\s*PyHeapTypeObject \*et;\s*type\s*=",
    body,
), "type_new_alloc: et must be in the opening declaration block (C89)"
assert len(re.findall(r"\bPyHeapTypeObject\s*\*\s*et\b", body)) == 1, (
    "declare et exactly once"
)
assert len(re.findall(r"\bet\s*=(?!=)", body)) == 1, (
    "assign et exactly once"
)
expected = """
    PyTypeObject *metatype = ctx->metatype;
    PyTypeObject *type;
    PyHeapTypeObject *et;
    type = (PyTypeObject *)metatype->tp_alloc(metatype, ctx->nslot);
    if (type == NULL) {
        return NULL;
    }
    et = (PyHeapTypeObject *)type;
"""
prefix = body.split("type->tp_flags =", 1)[0]
assert prefix.split() == expected.split(), (
    "type_new_alloc: preserve allocation, NULL check, and heap-type cast "
    "before flag initialization in their original order"
)
print("type_new_alloc heap-type C89 declaration and cast timing: PASS")