diff --git a/include/pybind11/functional.h b/include/pybind11/functional.h index cc7099c6a..b9bf38919 100644 --- a/include/pybind11/functional.h +++ b/include/pybind11/functional.h @@ -43,27 +43,33 @@ public: captured variables), in which case the roundtrip can be avoided. */ if (auto cfunc = func.cpp_function()) { - auto c = reinterpret_borrow(PyCFunction_GET_SELF(cfunc.ptr())); - auto rec = (function_record *) c; + auto cfunc_self = PyCFunction_GET_SELF(cfunc.ptr()); + if (isinstance(cfunc_self)) { + auto c = reinterpret_borrow(cfunc_self); + auto rec = (function_record *) c; - while (rec != nullptr) { - if (rec->is_stateless - && same_type(typeid(function_type), - *reinterpret_cast(rec->data[1]))) { - struct capture { - function_type f; - }; - value = ((capture *) &rec->data)->f; - return true; + while (rec != nullptr) { + if (rec->is_stateless + && same_type(typeid(function_type), + *reinterpret_cast(rec->data[1]))) { + struct capture { + function_type f; + }; + value = ((capture *) &rec->data)->f; + return true; + } + rec = rec->next; } - rec = rec->next; } + // PYPY segfaults here when passing builtin function like sum. + // Raising an fail exception here works to prevent the segfault, but only on gcc. + // See PR #1413 for full details } // ensure GIL is held during functor destruction struct func_handle { function f; - func_handle(function&& f_) : f(std::move(f_)) {} + func_handle(function &&f_) noexcept : f(std::move(f_)) {} func_handle(const func_handle& f_) { gil_scoped_acquire acq; f = f_.f; @@ -77,7 +83,7 @@ public: // to emulate 'move initialization capture' in C++11 struct func_wrapper { func_handle hfunc; - func_wrapper(func_handle&& hf): hfunc(std::move(hf)) {} + func_wrapper(func_handle &&hf) noexcept : hfunc(std::move(hf)) {} Return operator()(Args... args) const { gil_scoped_acquire acq; object retval(hfunc.f(std::forward(args)...)); diff --git a/tests/test_callbacks.cpp b/tests/test_callbacks.cpp index a208b44d0..a50771038 100644 --- a/tests/test_callbacks.cpp +++ b/tests/test_callbacks.cpp @@ -156,6 +156,12 @@ TEST_SUBMODULE(callbacks, m) { .def(py::init<>()) .def("triple", [](CppBoundMethodTest &, int val) { return 3 * val; }); + // This checks that builtin functions can be passed as callbacks + // rather than throwing RuntimeError due to trying to extract as capsule + m.def("test_sum_builtin", [](const std::function &sum_builtin, const py::iterable &i) { + return sum_builtin(i); + }); + // test async Python callbacks using callback_f = std::function; m.def("test_async_callback", [](const callback_f &f, const py::list &work) { diff --git a/tests/test_callbacks.py b/tests/test_callbacks.py index 397bf63d2..5bc4d1773 100644 --- a/tests/test_callbacks.py +++ b/tests/test_callbacks.py @@ -3,6 +3,7 @@ import pytest from pybind11_tests import callbacks as m from threading import Thread import time +import env # NOQA: F401 def test_callbacks(): @@ -124,6 +125,16 @@ def test_movable_object(): assert m.callback_with_movable(lambda _: None) is True +@pytest.mark.skipif( + "env.PYPY", + reason="PyPy segfaults on here. See discussion on #1413.", +) +def test_python_builtins(): + """Test if python builtins like sum() can be used as callbacks""" + assert m.test_sum_builtin(sum, [1, 2, 3]) == 6 + assert m.test_sum_builtin(sum, []) == 0 + + def test_async_callbacks(): # serves as state for async callback class Item: