#!/usr/bin/env python3
"""Keep type_add_method locals C89-compatible without moving API calls."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(r"\nstatic int\ntype_add_method\(PyTypeObject \*type, PyMethodDef \*meth\)\n\{(.*?)\n\}", source, re.S)
assert match, "type_add_method definition missing"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", match.group(1), flags=re.S)
assert re.match(r"\s*PyObject \*descr;\s*PyObject \*name;\s*int err;\s*int isdescr = 1;\s*if", body), (
    "type_add_method: name and err must be in the opening C89 declaration block"
)
for declaration in (r"\bPyObject\s*\*\s*name\b", r"\bint\s+err\b"):
    assert len(re.findall(declaration, body)) == 1, "declare each moved local exactly once"

# Search in execution order: duplicate cleanup calls occur on error paths.
ordered = [
    "if (meth->ml_flags & METH_CLASS)",
    "if (meth->ml_flags & METH_STATIC)",
    "descr = PyDescr_NewClassMethod(type, meth);",
    "else if (meth->ml_flags & METH_STATIC)",
    "PyObject *cfunc = PyCFunction_NewEx(meth, (PyObject*)type, NULL);",
    "descr = PyStaticMethod_New(cfunc);",
    "isdescr = 0;",
    "Py_DECREF(cfunc);",
    "descr = PyDescr_NewMethod(type, meth);",
    "if (descr == NULL)",
    "if (isdescr)",
    "name = PyDescr_NAME(descr);",
    "name = PyUnicode_FromString(meth->ml_name);",
    "if (name == NULL)",
    "Py_DECREF(descr);",
    "if (!(meth->ml_flags & METH_COEXIST))",
    "err = PyDict_SetDefault(type->tp_dict, name, descr) == NULL;",
    "err = PyDict_SetItem(type->tp_dict, name, descr) < 0;",
    "if (!isdescr)",
    "Py_DECREF(name);",
    "Py_DECREF(descr);",
    "if (err)",
    "return -1;",
    "return 0;",
]
cursor = 0
for token in ordered:
    position = body.find(token, cursor)
    assert position >= 0, f"type_add_method: missing or reordered operation: {token}"
    cursor = position + len(token)
assert len(re.findall(r"\bname\s*=(?!=)", body)) == 2, "retain both name assignment branches"
assert len(re.findall(r"\berr\s*=(?!=)", body)) == 2, "retain both dictionary insertion branches"
print("type_add_method C89 locals, branch ordering and reference cleanup: PASS")