// Copyright (c) 2024-2025 The Pybind Development Team.
// All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// For background see the description of PR google/pybind11clif#30099.
#pragma once
#include <pybind11/attr.h>
#include <pybind11/conduit/pybind11_platform_abi_id.h>
#include <pybind11/pytypes.h>
#include "common.h"
#include <cstring>
#include <utility>
PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
PYBIND11_NAMESPACE_BEGIN(detail)
struct function_record_PyObject {
PyObject_HEAD
function_record *cpp_func_rec;
};
PYBIND11_NAMESPACE_BEGIN(function_record_PyTypeObject_methods)
PyObject *tp_new_impl(PyTypeObject *type, PyObject *args, PyObject *kwds);
PyObject *tp_alloc_impl(PyTypeObject *type, Py_ssize_t nitems);
int tp_init_impl(PyObject *self, PyObject *args, PyObject *kwds);
void tp_dealloc_impl(PyObject *self);
void tp_free_impl(void *self);
static PyObject *reduce_ex_impl(PyObject *self, PyObject *, PyObject *);
static PyMethodDef tp_methods_impl[]
= {{"__reduce_ex__",
// reduce_ex_impl is a PyCFunctionWithKeywords, but PyMethodDef
// requires a PyCFunction. The cast through void* is safe and
// idiomatic with METH_KEYWORDS, and it successfully sidesteps
// unhelpful compiler warnings.
// NOLINTNEXTLINE(bugprone-casting-through-void)
reinterpret_cast<PyCFunction>(reinterpret_cast<void *>(reduce_ex_impl)),
METH_VARARGS | METH_KEYWORDS,
nullptr},
{nullptr, nullptr, 0, nullptr}};
// Python 3.12+ emits a DeprecationWarning for heap types whose tp_name does
// not contain a dot ('.') and that lack a __module__ attribute. For pybind11's
// internal function_record type, we do not have an actual module object to
// attach, so we cannot use PyType_FromModuleAndSpec (introduced in Python 3.9)
// to set __module__ automatically.
//
// As a workaround, we define a "qualified" type name that includes a dummy
// module name (PYBIND11_DUMMY_MODULE_NAME). This is non‑idiomatic but avoids
// the deprecation warning, and results in reprs like
//
// <class 'pybind11_builtins.pybind11_detail_function_record_...'>
//
// even though no real pybind11_builtins module exists. If pybind11 gains an
// actual module object in the future, this code should switch to
// PyType_FromModuleAndSpec for Python 3.9+ and drop the dummy module
// workaround.
//
// Note that this name is versioned.
#define PYBIND11_DETAIL_FUNCTION_RECORD_TP_PLAINNAME \
"pybind11_detail_function_record_" PYBIND11_DETAIL_FUNCTION_RECORD_ABI_ID \
"_" PYBIND11_PLATFORM_ABI_ID
constexpr char tp_plainname_impl[] = PYBIND11_DETAIL_FUNCTION_RECORD_TP_PLAINNAME;
constexpr char tp_qualname_impl[]
= PYBIND11_DUMMY_MODULE_NAME "." PYBIND11_DETAIL_FUNCTION_RECORD_TP_PLAINNAME;
PYBIND11_NAMESPACE_END(function_record_PyTypeObject_methods)
static PyType_Slot function_record_PyType_Slots[] = {
{Py_tp_dealloc,
reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_dealloc_impl)},
{Py_tp_methods,
reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_methods_impl)},
{Py_tp_init, reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_init_impl)},
{Py_tp_alloc, reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_alloc_impl)},
{Py_tp_new, reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_new_impl)},
{Py_tp_free, reinterpret_cast<void *>(function_record_PyTypeObject_methods::tp_free_impl)},
{0, nullptr}};
static PyType_Spec function_record_PyType_Spec
= {function_record_PyTypeObject_methods::tp_qualname_impl,
sizeof(function_record_PyObject),
0,
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HEAPTYPE,
function_record_PyType_Slots};
inline PyTypeObject *get_function_record_PyTypeObject() {
PYBIND11_LOCK_INTERNALS(get_internals());
PyTypeObject *&py_type_obj = detail::get_local_internals().function_record_py_type;
if (!py_type_obj) {
PyObject *py_obj = PyType_FromSpec(&function_record_PyType_Spec);
if (py_obj == nullptr) {
throw error_already_set();
}
py_type_obj = reinterpret_cast<PyTypeObject *>(py_obj);
}
return py_type_obj;
}
inline bool is_function_record_PyObject(PyObject *obj) {
if (PyType_Check(obj) != 0) {
return false;
}
PyTypeObject *obj_type = Py_TYPE(obj);
PyTypeObject *frtype = get_function_record_PyTypeObject();
// Fast path (pointer comparison).
if (obj_type == frtype) {
return true;
}
// This works across extension modules. Note that tp_name is versioned.
if (strcmp(obj_type->tp_name, function_record_PyTypeObject_methods::tp_qualname_impl) == 0
|| strcmp(obj_type->tp_name, function_record_PyTypeObject_methods::tp_plainname_impl)
== 0) {
return true;
}
return false;
}
inline function_record *function_record_ptr_from_PyObject(PyObject *obj) {
if (is_function_record_PyObject(obj)) {
return (reinterpret_cast<detail::function_record_PyObject *>(obj))->cpp_func_rec;
}
return nullptr;
}
inline object function_record_PyObject_New() {
auto *py_func_rec = PyObject_New(function_record_PyObject, get_function_record_PyTypeObject());
if (py_func_rec == nullptr) {
throw error_already_set();
}
py_func_rec->cpp_func_rec = nullptr; // For clarity/purity. Redundant in practice.
return reinterpret_steal<object>(reinterpret_cast<PyObject *>(py_func_rec));
}
PYBIND11_NAMESPACE_BEGIN(function_record_PyTypeObject_methods)
// Guard against accidents & oversights, in particular when porting to future Python versions.
inline PyObject *tp_new_impl(PyTypeObject *, PyObject *, PyObject *) {
pybind11_fail("UNEXPECTED CALL OF function_record_PyTypeObject_methods::tp_new_impl");
// return nullptr; // Unreachable.
}
inline PyObject *tp_alloc_impl(PyTypeObject *, Py_ssize_t) {
pybind11_fail("UNEXPECTED CALL OF function_record_PyTypeObject_methods::tp_alloc_impl");
// return nullptr; // Unreachable.
}
inline int tp_init_impl(PyObject *, PyObject *, PyObject *) {
pybind11_fail("UNEXPECTED CALL OF function_record_PyTypeObject_methods::tp_init_impl");
// return -1; // Unreachable.
}
inline void tp_free_impl(void *) {
pybind11_fail("UNEXPECTED CALL OF function_record_PyTypeObject_methods::tp_free_impl");
}
inline PyObject *reduce_ex_impl(PyObject *self, PyObject *, PyObject *) {
// Deliberately ignoring the arguments for simplicity (expected is `protocol: int`).
const function_record *rec = function_record_ptr_from_PyObject(self);
if (rec == nullptr) {
pybind11_fail(
"FATAL: function_record_PyTypeObject reduce_ex_impl(): cannot obtain cpp_func_rec.");
}
if (rec->name != nullptr && rec->name[0] != '\0' && rec->scope
&& PyModule_Check(rec->scope.ptr()) != 0) {
object scope_module = get_scope_module(rec->scope);
if (scope_module) {
auto builtins = reinterpret_borrow<dict>(PyEval_GetBuiltins());
auto builtins_eval = builtins["eval"];
auto reconstruct_args = make_tuple(str("__import__('importlib').import_module('")
+ scope_module + str("')"));
return make_tuple(std::move(builtins_eval), std::move(reconstruct_args))
.release()
.ptr();
}
}
set_error(PyExc_RuntimeError, repr(self) + str(" is not pickleable."));
return nullptr;
}
PYBIND11_NAMESPACE_END(function_record_PyTypeObject_methods)
PYBIND11_NAMESPACE_END(detail)
PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)