#!/usr/bin/env python3
"""Check type_new_set_doc's tp_doc declaration and allocation timing."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic int\ntype_new_set_doc\(PyTypeObject \*type\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_new_set_doc definition missing"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", match.group(1), flags=re.S)
assert re.match(
    r"\s*const char \*doc_str;"
    r"\s*Py_ssize_t size;"
    r"\s*char \*tp_doc;"
    r"\s*PyObject \*doc = PyDict_GetItemWithError"
    r"\(type->tp_dict, &_Py_ID\(__doc__\)\);",
    body,
), "type_new_set_doc: tp_doc must be in the opening declaration block (C89)"
assert len(re.findall(r"\bchar\s*\*\s*tp_doc\b", body)) == 1, (
    "declare tp_doc exactly once"
)
assert len(re.findall(r"(?<!->)\btp_doc\s*=(?!=)", body)) == 1, (
    "assign local tp_doc exactly once"
)
assert len(re.findall(r"\bPyObject_Malloc\s*\(", body)) == 1, (
    "allocate exactly once"
)
assert re.search(
    r"size = strlen\(doc_str\) \+ 1;\s*"
    r"tp_doc = \(char \*\)PyObject_Malloc\(size\);\s*"
    r"if \(tp_doc == NULL\)",
    body,
), "preserve allocation after size calculation and before the NULL check"
print("type_new_set_doc tp_doc C89 declaration and allocation timing: PASS")