diff --git a/docs/advanced/exceptions.rst b/docs/advanced/exceptions.rst index 53981dc08f..616e2d7726 100644 --- a/docs/advanced/exceptions.rst +++ b/docs/advanced/exceptions.rst @@ -127,8 +127,7 @@ before a global translator is tried. Inside the translator, ``std::rethrow_exception`` should be used within a try block to re-throw the exception. One or more catch clauses to catch the appropriate exceptions should then be used with each clause using -``PyErr_SetString`` to set a Python exception or ``ex(string)`` to set -the python exception to a custom exception type (see below). +``py::set_error()`` (see below). To declare a custom Python exception type, declare a ``py::exception`` variable and use this in the associated exception translator (note: it is often useful @@ -142,14 +141,17 @@ standard python RuntimeError: .. code-block:: cpp - static py::exception exc(m, "MyCustomError"); + // This is a static object, so we must leak the Python reference: + // It is undefined when the destructor will run, possibly only after the + // Python interpreter is finalized already. + static py::handle exc = py::exception(m, "MyCustomError").release(); py::register_exception_translator([](std::exception_ptr p) { try { if (p) std::rethrow_exception(p); } catch (const MyCustomException &e) { - exc(e.what()); + py::set_error(exc, e.what()); } catch (const OtherException &e) { - PyErr_SetString(PyExc_RuntimeError, e.what()); + py::set_error(PyExc_RuntimeError, e.what()); } }); @@ -168,8 +170,7 @@ section. .. note:: - Call either ``PyErr_SetString`` or a custom exception's call - operator (``exc(string)``) for every exception caught in a custom exception + Call ``py::set_error()`` for every exception caught in a custom exception translator. Failure to do so will cause Python to crash with ``SystemError: error return without exception set``. @@ -200,7 +201,7 @@ If module1 has the following translator: try { if (p) std::rethrow_exception(p); } catch (const std::invalid_argument &e) { - PyErr_SetString("module1 handled this") + py::set_error(PyExc_ArgumentError, "module1 handled this"); } } @@ -212,7 +213,7 @@ and module2 has the following similar translator: try { if (p) std::rethrow_exception(p); } catch (const std::invalid_argument &e) { - PyErr_SetString("module2 handled this") + py::set_error(PyExc_ArgumentError, "module2 handled this"); } } @@ -312,11 +313,11 @@ error protocol, which is outlined here. After calling the Python C API, if Python returns an error, ``throw py::error_already_set();``, which allows pybind11 to deal with the exception and pass it back to the Python interpreter. This includes calls to -the error setting functions such as ``PyErr_SetString``. +the error setting functions such as ``py::set_error()``. .. code-block:: cpp - PyErr_SetString(PyExc_TypeError, "C API type error demo"); + py::set_error(PyExc_TypeError, "C API type error demo"); throw py::error_already_set(); // But it would be easier to simply... diff --git a/include/pybind11/detail/class.h b/include/pybind11/detail/class.h index bc2b40c50a..3ece0643bd 100644 --- a/include/pybind11/detail/class.h +++ b/include/pybind11/detail/class.h @@ -375,7 +375,7 @@ extern "C" inline PyObject *pybind11_object_new(PyTypeObject *type, PyObject *, extern "C" inline int pybind11_object_init(PyObject *self, PyObject *, PyObject *) { PyTypeObject *type = Py_TYPE(self); std::string msg = get_fully_qualified_tp_name(type) + ": No constructor defined!"; - PyErr_SetString(PyExc_TypeError, msg.c_str()); + set_error(PyExc_TypeError, msg.c_str()); return -1; } @@ -579,7 +579,7 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla if (view) { view->obj = nullptr; } - PyErr_SetString(PyExc_BufferError, "pybind11_getbuffer(): Internal error"); + set_error(PyExc_BufferError, "pybind11_getbuffer(): Internal error"); return -1; } std::memset(view, 0, sizeof(Py_buffer)); @@ -587,7 +587,7 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla if ((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE && info->readonly) { delete info; // view->obj = nullptr; // Was just memset to 0, so not necessary - PyErr_SetString(PyExc_BufferError, "Writable buffer requested for readonly storage"); + set_error(PyExc_BufferError, "Writable buffer requested for readonly storage"); return -1; } view->obj = obj; diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h index 7ebc01c5d9..e79f7693d0 100644 --- a/include/pybind11/detail/common.h +++ b/include/pybind11/detail/common.h @@ -399,7 +399,7 @@ PYBIND11_WARNING_POP return nullptr; \ } \ catch (const std::exception &e) { \ - PyErr_SetString(PyExc_ImportError, e.what()); \ + ::pybind11::set_error(PyExc_ImportError, e.what()); \ return nullptr; \ } diff --git a/include/pybind11/detail/internals.h b/include/pybind11/detail/internals.h index aaa7f8686e..228dd764b7 100644 --- a/include/pybind11/detail/internals.h +++ b/include/pybind11/detail/internals.h @@ -352,7 +352,7 @@ inline bool raise_err(PyObject *exc_type, const char *msg) { raise_from(exc_type, msg); return true; } - PyErr_SetString(exc_type, msg); + set_error(exc_type, msg); return false; } diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h index 16387506cf..fc5f1c88b3 100644 --- a/include/pybind11/detail/type_caster_base.h +++ b/include/pybind11/detail/type_caster_base.h @@ -786,7 +786,7 @@ class type_caster_generic { std::string tname = rtti_type ? rtti_type->name() : cast_type.name(); detail::clean_type_id(tname); std::string msg = "Unregistered type : " + tname; - PyErr_SetString(PyExc_TypeError, msg.c_str()); + set_error(PyExc_TypeError, msg.c_str()); return {nullptr, nullptr}; } diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h index 36077ec04d..02f65d740d 100644 --- a/include/pybind11/numpy.h +++ b/include/pybind11/numpy.h @@ -1008,7 +1008,7 @@ class array : public buffer { /// Create array from any object -- always returns a new reference static PyObject *raw_array(PyObject *ptr, int ExtraFlags = 0) { if (ptr == nullptr) { - PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array from a nullptr"); + set_error(PyExc_ValueError, "cannot create a pybind11::array from a nullptr"); return nullptr; } return detail::npy_api::get().PyArray_FromAny_( @@ -1155,7 +1155,7 @@ class array_t : public array { /// Create array from any object -- always returns a new reference static PyObject *raw_array_t(PyObject *ptr) { if (ptr == nullptr) { - PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array_t from a nullptr"); + set_error(PyExc_ValueError, "cannot create a pybind11::array_t from a nullptr"); return nullptr; } return detail::npy_api::get().PyArray_FromAny_(ptr, diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h index 3bce1a01ba..76edf7f1f1 100644 --- a/include/pybind11/pybind11.h +++ b/include/pybind11/pybind11.h @@ -694,9 +694,8 @@ class cpp_function : public function { if (overloads->is_constructor) { if (!parent || !PyObject_TypeCheck(parent.ptr(), (PyTypeObject *) overloads->scope.ptr())) { - PyErr_SetString( - PyExc_TypeError, - "__init__(self, ...) called with invalid or missing `self` argument"); + set_error(PyExc_TypeError, + "__init__(self, ...) called with invalid or missing `self` argument"); return nullptr; } @@ -1007,7 +1006,7 @@ class cpp_function : public function { A translator may choose to do one of the following: - - catch the exception and call PyErr_SetString or PyErr_SetObject + - catch the exception and call py::set_error() to set a standard (or custom) Python exception, or - do nothing and let the exception fall through to the next translator, or - delegate translation to the next translator by throwing a new type of exception. @@ -1023,8 +1022,7 @@ class cpp_function : public function { return nullptr; } - PyErr_SetString(PyExc_SystemError, - "Exception escaped from default exception translator!"); + set_error(PyExc_SystemError, "Exception escaped from default exception translator!"); return nullptr; } @@ -1125,7 +1123,7 @@ class cpp_function : public function { raise_from(PyExc_TypeError, msg.c_str()); return nullptr; } - PyErr_SetString(PyExc_TypeError, msg.c_str()); + set_error(PyExc_TypeError, msg.c_str()); return nullptr; } if (!result) { @@ -1138,7 +1136,7 @@ class cpp_function : public function { raise_from(PyExc_TypeError, msg.c_str()); return nullptr; } - PyErr_SetString(PyExc_TypeError, msg.c_str()); + set_error(PyExc_TypeError, msg.c_str()); return nullptr; } if (overloads->is_constructor && !self_value_and_holder.holder_constructed()) { @@ -2528,7 +2526,7 @@ inline void register_local_exception_translator(ExceptionTranslator &&translator /** * Wrapper to generate a new Python exception type. * - * This should only be used with PyErr_SetString for now. + * This should only be used with py::set_error() for now. * It is not (yet) possible to use as a py::base. * Template type argument is reserved for future use. */ @@ -2549,7 +2547,9 @@ class exception : public object { } // Sets the current python exception to this exception object with the given message - void operator()(const char *message) { PyErr_SetString(m_ptr, message); } + PYBIND11_DEPRECATED("Please use py::set_error() instead " + "(https://github.com/pybind/pybind11/pull/4772)") + void operator()(const char *message) const { set_error(*this, message); } }; PYBIND11_NAMESPACE_BEGIN(detail) @@ -2581,7 +2581,7 @@ register_exception_impl(handle scope, const char *name, handle base, bool isLoca try { std::rethrow_exception(p); } catch (const CppException &e) { - detail::get_exception_object()(e.what()); + set_error(detail::get_exception_object(), e.what()); } }); return ex; diff --git a/include/pybind11/pytypes.h b/include/pybind11/pytypes.h index 580a4658ef..fa2d249844 100644 --- a/include/pybind11/pytypes.h +++ b/include/pybind11/pytypes.h @@ -334,6 +334,14 @@ class handle : public detail::object_api { #endif }; +inline void set_error(const handle &type, const char *message) { + PyErr_SetString(type.ptr(), message); +} + +inline void set_error(const handle &type, const handle &value) { + PyErr_SetObject(type.ptr(), value.ptr()); +} + /** \rst Holds a reference to a Python object (with reference counting) diff --git a/tests/cross_module_interleaved_error_already_set.cpp b/tests/cross_module_interleaved_error_already_set.cpp index fdd9939e45..3493a7e615 100644 --- a/tests/cross_module_interleaved_error_already_set.cpp +++ b/tests/cross_module_interleaved_error_already_set.cpp @@ -16,12 +16,12 @@ namespace { namespace py = pybind11; void interleaved_error_already_set() { - PyErr_SetString(PyExc_RuntimeError, "1st error."); + py::set_error(PyExc_RuntimeError, "1st error."); try { throw py::error_already_set(); } catch (const py::error_already_set &) { // The 2nd error could be conditional in a real application. - PyErr_SetString(PyExc_RuntimeError, "2nd error."); + py::set_error(PyExc_RuntimeError, "2nd error."); } // Here the 1st error is destroyed before the 2nd error is fetched. // The error_already_set dtor triggers a pybind11::detail::get_internals() // call via pybind11::gil_scoped_acquire. diff --git a/tests/pybind11_cross_module_tests.cpp b/tests/pybind11_cross_module_tests.cpp index 9379f3f259..ad68e9a54f 100644 --- a/tests/pybind11_cross_module_tests.cpp +++ b/tests/pybind11_cross_module_tests.cpp @@ -31,11 +31,11 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) { // test_exceptions.py py::register_local_exception(m, "LocalSimpleException"); m.def("raise_runtime_error", []() { - PyErr_SetString(PyExc_RuntimeError, "My runtime error"); + py::set_error(PyExc_RuntimeError, "My runtime error"); throw py::error_already_set(); }); m.def("raise_value_error", []() { - PyErr_SetString(PyExc_ValueError, "My value error"); + py::set_error(PyExc_ValueError, "My value error"); throw py::error_already_set(); }); m.def("throw_pybind_value_error", []() { throw py::value_error("pybind11 value error"); }); @@ -49,7 +49,7 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) { std::rethrow_exception(p); } } catch (const shared_exception &e) { - PyErr_SetString(PyExc_KeyError, e.what()); + py::set_error(PyExc_KeyError, e.what()); } }); @@ -60,7 +60,7 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) { std::rethrow_exception(p); } } catch (const LocalException &e) { - PyErr_SetString(PyExc_KeyError, e.what()); + py::set_error(PyExc_KeyError, e.what()); } }); diff --git a/tests/test_exceptions.cpp b/tests/test_exceptions.cpp index 854c7e6f76..f6d9c215c9 100644 --- a/tests/test_exceptions.cpp +++ b/tests/test_exceptions.cpp @@ -25,6 +25,10 @@ class MyException : public std::exception { std::string message = ""; }; +class MyExceptionUseDeprecatedOperatorCall : public MyException { + using MyException::MyException; +}; + // A type that should be translated to a standard Python exception class MyException2 : public std::exception { public: @@ -109,8 +113,8 @@ TEST_SUBMODULE(exceptions, m) { m.def("throw_std_exception", []() { throw std::runtime_error("This exception was intentionally thrown."); }); - // make a new custom exception and use it as a translation target - static py::exception ex(m, "MyException"); + // PLEASE KEEP IN SYNC with docs/advanced/exceptions.rst + static py::handle ex = py::exception(m, "MyException").release(); py::register_exception_translator([](std::exception_ptr p) { try { if (p) { @@ -118,7 +122,32 @@ TEST_SUBMODULE(exceptions, m) { } } catch (const MyException &e) { // Set MyException as the active python error - ex(e.what()); + py::set_error(ex, e.what()); + } + }); + + // Same as above, but using the deprecated `py::exception<>::operator()` + // We want to be sure it still works, until it's removed. + static const auto *const exd = new py::exception( + m, "MyExceptionUseDeprecatedOperatorCall"); + py::register_exception_translator([](std::exception_ptr p) { + try { + if (p) { + std::rethrow_exception(p); + } + } catch (const MyExceptionUseDeprecatedOperatorCall &e) { +#if defined(__INTEL_COMPILER) || defined(__NVCOMPILER) + // It is not worth the trouble dealing with warning suppressions for these compilers. + // Falling back to the recommended approach to keep the test code simple. + py::set_error(*exd, e.what()); +#else + PYBIND11_WARNING_PUSH + PYBIND11_WARNING_DISABLE_CLANG("-Wdeprecated-declarations") + PYBIND11_WARNING_DISABLE_GCC("-Wdeprecated-declarations") + PYBIND11_WARNING_DISABLE_MSVC(4996) + (*exd)(e.what()); + PYBIND11_WARNING_POP +#endif } }); @@ -132,7 +161,7 @@ TEST_SUBMODULE(exceptions, m) { } } catch (const MyException2 &e) { // Translate this exception to a standard RuntimeError - PyErr_SetString(PyExc_RuntimeError, e.what()); + py::set_error(PyExc_RuntimeError, e.what()); } }); @@ -162,11 +191,16 @@ TEST_SUBMODULE(exceptions, m) { std::rethrow_exception(p); } } catch (const MyException6 &e) { - PyErr_SetString(PyExc_RuntimeError, e.what()); + py::set_error(PyExc_RuntimeError, e.what()); } }); - m.def("throws1", []() { throw MyException("this error should go to a custom type"); }); + m.def("throws1", + []() { throw MyException("this error should go to py::exception"); }); + m.def("throws1d", []() { + throw MyExceptionUseDeprecatedOperatorCall( + "this error should go to py::exception"); + }); m.def("throws2", []() { throw MyException2("this error should go to a standard Python exception"); }); m.def("throws3", []() { throw MyException3("this error cannot be translated"); }); @@ -222,7 +256,7 @@ TEST_SUBMODULE(exceptions, m) { m.def("throw_already_set", [](bool err) { if (err) { - PyErr_SetString(PyExc_ValueError, "foo"); + py::set_error(PyExc_ValueError, "foo"); } try { throw py::error_already_set(); @@ -238,7 +272,7 @@ TEST_SUBMODULE(exceptions, m) { } PyErr_Clear(); if (err) { - PyErr_SetString(PyExc_ValueError, "foo"); + py::set_error(PyExc_ValueError, "foo"); } throw py::error_already_set(); }); @@ -247,7 +281,7 @@ TEST_SUBMODULE(exceptions, m) { bool retval = false; try { PythonCallInDestructor set_dict_in_destructor(d); - PyErr_SetString(PyExc_ValueError, "foo"); + py::set_error(PyExc_ValueError, "foo"); throw py::error_already_set(); } catch (const py::error_already_set &) { retval = true; @@ -282,14 +316,14 @@ TEST_SUBMODULE(exceptions, m) { m.def("throw_should_be_translated_to_key_error", []() { throw shared_exception(); }); m.def("raise_from", []() { - PyErr_SetString(PyExc_ValueError, "inner"); + py::set_error(PyExc_ValueError, "inner"); py::raise_from(PyExc_ValueError, "outer"); throw py::error_already_set(); }); m.def("raise_from_already_set", []() { try { - PyErr_SetString(PyExc_ValueError, "inner"); + py::set_error(PyExc_ValueError, "inner"); throw py::error_already_set(); } catch (py::error_already_set &e) { py::raise_from(e, PyExc_ValueError, "outer"); @@ -306,7 +340,7 @@ TEST_SUBMODULE(exceptions, m) { }); m.def("error_already_set_what", [](const py::object &exc_type, const py::object &exc_value) { - PyErr_SetObject(exc_type.ptr(), exc_value.ptr()); + py::set_error(exc_type, exc_value); std::string what = py::error_already_set().what(); bool py_err_set_after_what = (PyErr_Occurred() != nullptr); PyErr_Clear(); @@ -321,7 +355,7 @@ TEST_SUBMODULE(exceptions, m) { }); m.def("test_error_already_set_double_restore", [](bool dry_run) { - PyErr_SetString(PyExc_ValueError, "Random error."); + py::set_error(PyExc_ValueError, "Random error."); py::error_already_set e; e.restore(); PyErr_Clear(); diff --git a/tests/test_exceptions.h b/tests/test_exceptions.h index 03684b89fa..2eaa3d3d16 100644 --- a/tests/test_exceptions.h +++ b/tests/test_exceptions.h @@ -9,5 +9,5 @@ class PYBIND11_EXPORT_EXCEPTION shared_exception : public pybind11::builtin_exce public: using builtin_exception::builtin_exception; explicit shared_exception() : shared_exception("") {} - void set_error() const override { PyErr_SetString(PyExc_RuntimeError, what()); } + void set_error() const override { py::set_error(PyExc_RuntimeError, what()); } }; diff --git a/tests/test_exceptions.py b/tests/test_exceptions.py index ccac4536d6..5d8e6292aa 100644 --- a/tests/test_exceptions.py +++ b/tests/test_exceptions.py @@ -139,7 +139,15 @@ def test_custom(msg): # Can we catch a MyException? with pytest.raises(m.MyException) as excinfo: m.throws1() - assert msg(excinfo.value) == "this error should go to a custom type" + assert msg(excinfo.value) == "this error should go to py::exception" + + # Can we catch a MyExceptionUseDeprecatedOperatorCall? + with pytest.raises(m.MyExceptionUseDeprecatedOperatorCall) as excinfo: + m.throws1d() + assert ( + msg(excinfo.value) + == "this error should go to py::exception" + ) # Can we translate to standard Python exceptions? with pytest.raises(RuntimeError) as excinfo: diff --git a/tests/test_pytypes.cpp b/tests/test_pytypes.cpp index cb2f76c031..b03f5624e1 100644 --- a/tests/test_pytypes.cpp +++ b/tests/test_pytypes.cpp @@ -25,7 +25,7 @@ PyObject *conv(PyObject *o) { ret = PyFloat_FromDouble(v); } } else { - PyErr_SetString(PyExc_TypeError, "Unexpected type"); + py::set_error(PyExc_TypeError, "Unexpected type"); } return ret; } diff --git a/tests/test_type_caster_pyobject_ptr.cpp b/tests/test_type_caster_pyobject_ptr.cpp index 1667ea1266..8069f7dcd9 100644 --- a/tests/test_type_caster_pyobject_ptr.cpp +++ b/tests/test_type_caster_pyobject_ptr.cpp @@ -78,14 +78,14 @@ TEST_SUBMODULE(type_caster_pyobject_ptr, m) { m.def("cast_to_pyobject_ptr_nullptr", [](bool set_error) { if (set_error) { - PyErr_SetString(PyExc_RuntimeError, "Reflective of healthy error handling."); + py::set_error(PyExc_RuntimeError, "Reflective of healthy error handling."); } PyObject *ptr = nullptr; py::cast(ptr); }); m.def("cast_to_pyobject_ptr_non_nullptr_with_error_set", []() { - PyErr_SetString(PyExc_RuntimeError, "Reflective of unhealthy error handling."); + py::set_error(PyExc_RuntimeError, "Reflective of unhealthy error handling."); py::cast(Py_None); });