#!/usr/bin/env python3
"""Guard the entry locals and evaluation order in _PyObject_FunctionStr."""

import re
import sys
from pathlib import Path

source = Path(sys.argv[1]).read_text()
found = re.search(
    r"\n_PyObject_FunctionStr\(PyObject \*x\)\s*\{(?P<body>.*?)\n\}",
    source,
    re.S,
)
assert found, "_PyObject_FunctionStr definition not found"
body = found.group("body")
for name in ("module", "result"):
    declarations = re.findall(r"\bPyObject\s*\*\s*" + name + r"\b", body)
    assert len(declarations) == 1, (
        f"_PyObject_FunctionStr must declare {name} exactly once at entry; "
        f"found {len(declarations)} declarations"
    )

tokens = (
    "PyObject *module;",
    "PyObject *result;",
    "int ret;",
    "assert(!PyErr_Occurred());",
    "ret = _PyObject_LookupAttr(x, &_Py_ID(__qualname__), &qualname);",
    "if (qualname == NULL)",
    "return PyObject_Str(x);",
    "result = NULL;",
    "ret = _PyObject_LookupAttr(x, &_Py_ID(__module__), &module);",
    "ret = PyObject_RichCompareBool(module, &_Py_ID(builtins), Py_NE);",
    'result = PyUnicode_FromFormat("%S.%S()", module, qualname);',
    'result = PyUnicode_FromFormat("%S()", qualname);',
    "Py_DECREF(qualname);",
    "Py_XDECREF(module);",
    "return result;",
)
positions = [body.find(token) for token in tokens]
assert all(position >= 0 for position in positions) and positions == sorted(positions), (
    "_PyObject_FunctionStr must keep locals at entry and preserve evaluation/statement order"
)
print("object _PyObject_FunctionStr unique C89 locals and evaluation order: PASS")