/* tests/test_custom-exceptions.cpp -- exception translation Copyright (c) 2016 Pim Schellart All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. */ #include #include "test_exceptions.h" #include "local_bindings.h" #include "pybind11_tests.h" #include #include #include // A type that should be raised as an exception in Python class MyException : public std::exception { public: explicit MyException(const char *m) : message{m} {} const char *what() const noexcept override { return message.c_str(); } private: 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: explicit MyException2(const char *m) : message{m} {} const char *what() const noexcept override { return message.c_str(); } private: std::string message = ""; }; // A type that is not derived from std::exception (and is thus unknown) class MyException3 { public: explicit MyException3(const char *m) : message{m} {} virtual const char *what() const noexcept { return message.c_str(); } // Rule of 5 BEGIN: to preempt compiler warnings. MyException3(const MyException3 &) = default; MyException3(MyException3 &&) = default; MyException3 &operator=(const MyException3 &) = default; MyException3 &operator=(MyException3 &&) = default; virtual ~MyException3() = default; // Rule of 5 END. private: std::string message = ""; }; // A type that should be translated to MyException // and delegated to its exception translator class MyException4 : public std::exception { public: explicit MyException4(const char *m) : message{m} {} const char *what() const noexcept override { return message.c_str(); } private: std::string message = ""; }; // Like the above, but declared via the helper function class MyException5 : public std::logic_error { public: explicit MyException5(const std::string &what) : std::logic_error(what) {} }; // Inherits from MyException5 class MyException5_1 : public MyException5 { using MyException5::MyException5; }; // Exception that will be caught via the module local translator. class MyException6 : public std::exception { public: explicit MyException6(const char *m) : message{m} {} const char *what() const noexcept override { return message.c_str(); } private: std::string message = ""; }; struct PythonCallInDestructor { explicit PythonCallInDestructor(const py::dict &d) : d(d) {} ~PythonCallInDestructor() { d["good"] = true; } py::dict d; }; struct PythonAlreadySetInDestructor { explicit PythonAlreadySetInDestructor(const py::str &s) : s(s) {} ~PythonAlreadySetInDestructor() { py::dict foo; try { // Assign to a py::object to force read access of nonexistent dict entry py::object o = foo["bar"]; } catch (py::error_already_set &ex) { ex.discard_as_unraisable(s); } } py::str s; }; struct CustomData { explicit CustomData(const std::string &a) : a(a) {} std::string a; }; struct MyException7 { explicit MyException7(const CustomData &message) : message(message) {} CustomData message; }; TEST_SUBMODULE(exceptions, m) { m.def("throw_std_exception", []() { throw std::runtime_error("This exception was intentionally thrown."); }); // PLEASE KEEP IN SYNC with docs/advanced/exceptions.rst PYBIND11_CONSTINIT static py::gil_safe_call_once_and_store ex_storage; ex_storage.call_once_and_store_result( [&]() { return py::exception(m, "MyException"); }); py::register_exception_translator([](std::exception_ptr p) { try { if (p) { std::rethrow_exception(p); } } catch (const MyException &e) { // Set MyException as the active python error py::set_error(ex_storage.get_stored(), 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 } }); // register new translator for MyException2 // no need to store anything here because this type will // never by visible from Python py::register_exception_translator([](std::exception_ptr p) { try { if (p) { std::rethrow_exception(p); } } catch (const MyException2 &e) { // Translate this exception to a standard RuntimeError py::set_error(PyExc_RuntimeError, e.what()); } }); // register new translator for MyException4 // which will catch it and delegate to the previously registered // translator for MyException by throwing a new exception py::register_exception_translator([](std::exception_ptr p) { try { if (p) { std::rethrow_exception(p); } } catch (const MyException4 &e) { throw MyException(e.what()); } }); // A simple exception translation: auto ex5 = py::register_exception(m, "MyException5"); // A slightly more complicated one that declares MyException5_1 as a subclass of MyException5 py::register_exception(m, "MyException5_1", ex5.ptr()); // py::register_local_exception(m, "LocalSimpleException") py::register_local_exception_translator([](std::exception_ptr p) { try { if (p) { std::rethrow_exception(p); } } catch (const MyException6 &e) { py::set_error(PyExc_RuntimeError, e.what()); } }); 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"); }); m.def("throws4", []() { throw MyException4("this error is rethrown"); }); m.def("throws5", []() { throw MyException5("this is a helper-defined translated exception"); }); m.def("throws5_1", []() { throw MyException5_1("MyException5 subclass"); }); m.def("throws6", []() { throw MyException6("MyException6 only handled in this module"); }); m.def("throws_logic_error", []() { throw std::logic_error("this error should fall through to the standard handler"); }); m.def("throws_overflow_error", []() { throw std::overflow_error(""); }); m.def("throws_local_error", []() { throw LocalException("never caught"); }); m.def("throws_local_simple_error", []() { throw LocalSimpleException("this mod"); }); m.def("exception_matches", []() { py::dict foo; try { // Assign to a py::object to force read access of nonexistent dict entry py::object o = foo["bar"]; } catch (py::error_already_set &ex) { if (!ex.matches(PyExc_KeyError)) { throw; } return true; } return false; }); m.def("exception_matches_base", []() { py::dict foo; try { // Assign to a py::object to force read access of nonexistent dict entry py::object o = foo["bar"]; } catch (py::error_already_set &ex) { if (!ex.matches(PyExc_Exception)) { throw; } return true; } return false; }); m.def("modulenotfound_exception_matches_base", []() { try { // On Python >= 3.6, this raises a ModuleNotFoundError, a subclass of ImportError py::module_::import("nonexistent"); } catch (py::error_already_set &ex) { if (!ex.matches(PyExc_ImportError)) { throw; } return true; } return false; }); m.def("throw_already_set", [](bool err) { if (err) { py::set_error(PyExc_ValueError, "foo"); } try { throw py::error_already_set(); } catch (const std::runtime_error &e) { if ((err && e.what() != std::string("ValueError: foo")) || (!err && e.what() != std::string("Internal error: pybind11::error_already_set called " "while Python error indicator not set."))) { PyErr_Clear(); throw std::runtime_error("error message mismatch"); } } PyErr_Clear(); if (err) { py::set_error(PyExc_ValueError, "foo"); } throw py::error_already_set(); }); m.def("python_call_in_destructor", [](const py::dict &d) { bool retval = false; try { PythonCallInDestructor set_dict_in_destructor(d); py::set_error(PyExc_ValueError, "foo"); throw py::error_already_set(); } catch (const py::error_already_set &) { retval = true; } return retval; }); m.def("python_alreadyset_in_destructor", [](const py::str &s) { PythonAlreadySetInDestructor alreadyset_in_destructor(s); return true; }); // test_nested_throws m.def("try_catch", [m](const py::object &exc_type, const py::function &f, const py::args &args) { try { f(*args); } catch (py::error_already_set &ex) { if (ex.matches(exc_type)) { py::print(ex.what()); } else { // Simply `throw;` also works and is better, but using `throw ex;` // here to cover that situation (as observed in the wild). throw ex; // Invokes the copy ctor. } } }); // Test repr that cannot be displayed m.def("simple_bool_passthrough", [](bool x) { return x; }); m.def("throw_should_be_translated_to_key_error", []() { throw shared_exception(); }); m.def("raise_from", []() { py::set_error(PyExc_ValueError, "inner"); py::raise_from(PyExc_ValueError, "outer"); throw py::error_already_set(); }); m.def("raise_from_already_set", []() { try { py::set_error(PyExc_ValueError, "inner"); throw py::error_already_set(); } catch (py::error_already_set &e) { py::raise_from(e, PyExc_ValueError, "outer"); throw py::error_already_set(); } }); m.def("throw_nested_exception", []() { try { throw std::runtime_error("Inner Exception"); } catch (const std::runtime_error &) { std::throw_with_nested(std::runtime_error("Outer Exception")); } }); m.def("error_already_set_what", [](const py::object &exc_type, const py::object &exc_value) { 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(); return py::make_tuple(std::move(what), py_err_set_after_what); }); m.def("test_cross_module_interleaved_error_already_set", []() { auto cm = py::module_::import("cross_module_interleaved_error_already_set"); auto interleaved_error_already_set = reinterpret_cast(PyLong_AsVoidPtr(cm.attr("funcaddr").ptr())); interleaved_error_already_set(); }); m.def("test_error_already_set_double_restore", [](bool dry_run) { py::set_error(PyExc_ValueError, "Random error."); py::error_already_set e; e.restore(); PyErr_Clear(); if (!dry_run) { e.restore(); } }); // https://github.com/pybind/pybind11/issues/4075 m.def("test_pypy_oserror_normalization", []() { try { py::module_::import("io").attr("open")("this_filename_must_not_exist", "r"); } catch (const py::error_already_set &e) { return py::str(e.what()); // str must be built before e goes out of scope. } return py::str("UNEXPECTED"); }); m.def("test_fn_cast_int", [](const py::function &fn) { // function returns None instead of int, should give a useful error message fn().cast(); }); // m.def("pass_exception_void", [](const py::exception&) {}); // Does not compile. m.def("return_exception_void", []() { return py::exception(); }); m.def("throws7", []() { auto data = CustomData("abc"); throw MyException7(data); }); py::class_(m, "CustomData", py::module_local()) .def(py::init()) .def_readwrite("a", &CustomData::a); PYBIND11_CONSTINIT static py::gil_safe_call_once_and_store PythonMyException7_storage; PythonMyException7_storage.call_once_and_store_result([&]() { auto mod = py::module_::import("custom_exceptions"); py::object obj = mod.attr("PythonMyException7"); return obj; }); py::register_local_exception_translator([](std::exception_ptr p) { try { if (p) { std::rethrow_exception(p); } } catch (const MyException7 &e) { auto exc_type = PythonMyException7_storage.get_stored(); py::object exc_inst = exc_type(e.message); PyErr_SetObject(PyExc_Exception, exc_inst.ptr()); } }); }