111986Sandreas.sandberg@arm.com/* 211986Sandreas.sandberg@arm.com tests/test_custom-exceptions.cpp -- exception translation 311986Sandreas.sandberg@arm.com 411986Sandreas.sandberg@arm.com Copyright (c) 2016 Pim Schellart <P.Schellart@princeton.edu> 511986Sandreas.sandberg@arm.com 611986Sandreas.sandberg@arm.com All rights reserved. Use of this source code is governed by a 711986Sandreas.sandberg@arm.com BSD-style license that can be found in the LICENSE file. 811986Sandreas.sandberg@arm.com*/ 911986Sandreas.sandberg@arm.com 1011986Sandreas.sandberg@arm.com#include "pybind11_tests.h" 1111986Sandreas.sandberg@arm.com 1214299Sbbruce@ucdavis.edu// A type that should be raised as an exception in Python 1311986Sandreas.sandberg@arm.comclass MyException : public std::exception { 1411986Sandreas.sandberg@arm.compublic: 1511986Sandreas.sandberg@arm.com explicit MyException(const char * m) : message{m} {} 1611986Sandreas.sandberg@arm.com virtual const char * what() const noexcept override {return message.c_str();} 1711986Sandreas.sandberg@arm.comprivate: 1811986Sandreas.sandberg@arm.com std::string message = ""; 1911986Sandreas.sandberg@arm.com}; 2011986Sandreas.sandberg@arm.com 2111986Sandreas.sandberg@arm.com// A type that should be translated to a standard Python exception 2211986Sandreas.sandberg@arm.comclass MyException2 : public std::exception { 2311986Sandreas.sandberg@arm.compublic: 2411986Sandreas.sandberg@arm.com explicit MyException2(const char * m) : message{m} {} 2511986Sandreas.sandberg@arm.com virtual const char * what() const noexcept override {return message.c_str();} 2611986Sandreas.sandberg@arm.comprivate: 2711986Sandreas.sandberg@arm.com std::string message = ""; 2811986Sandreas.sandberg@arm.com}; 2911986Sandreas.sandberg@arm.com 3011986Sandreas.sandberg@arm.com// A type that is not derived from std::exception (and is thus unknown) 3111986Sandreas.sandberg@arm.comclass MyException3 { 3211986Sandreas.sandberg@arm.compublic: 3311986Sandreas.sandberg@arm.com explicit MyException3(const char * m) : message{m} {} 3411986Sandreas.sandberg@arm.com virtual const char * what() const noexcept {return message.c_str();} 3511986Sandreas.sandberg@arm.comprivate: 3611986Sandreas.sandberg@arm.com std::string message = ""; 3711986Sandreas.sandberg@arm.com}; 3811986Sandreas.sandberg@arm.com 3911986Sandreas.sandberg@arm.com// A type that should be translated to MyException 4011986Sandreas.sandberg@arm.com// and delegated to its exception translator 4111986Sandreas.sandberg@arm.comclass MyException4 : public std::exception { 4211986Sandreas.sandberg@arm.compublic: 4311986Sandreas.sandberg@arm.com explicit MyException4(const char * m) : message{m} {} 4411986Sandreas.sandberg@arm.com virtual const char * what() const noexcept override {return message.c_str();} 4511986Sandreas.sandberg@arm.comprivate: 4611986Sandreas.sandberg@arm.com std::string message = ""; 4711986Sandreas.sandberg@arm.com}; 4811986Sandreas.sandberg@arm.com 4911986Sandreas.sandberg@arm.com 5011986Sandreas.sandberg@arm.com// Like the above, but declared via the helper function 5111986Sandreas.sandberg@arm.comclass MyException5 : public std::logic_error { 5211986Sandreas.sandberg@arm.compublic: 5311986Sandreas.sandberg@arm.com explicit MyException5(const std::string &what) : std::logic_error(what) {} 5411986Sandreas.sandberg@arm.com}; 5511986Sandreas.sandberg@arm.com 5611986Sandreas.sandberg@arm.com// Inherits from MyException5 5711986Sandreas.sandberg@arm.comclass MyException5_1 : public MyException5 { 5811986Sandreas.sandberg@arm.com using MyException5::MyException5; 5911986Sandreas.sandberg@arm.com}; 6011986Sandreas.sandberg@arm.com 6111986Sandreas.sandberg@arm.comstruct PythonCallInDestructor { 6211986Sandreas.sandberg@arm.com PythonCallInDestructor(const py::dict &d) : d(d) {} 6311986Sandreas.sandberg@arm.com ~PythonCallInDestructor() { d["good"] = true; } 6411986Sandreas.sandberg@arm.com 6511986Sandreas.sandberg@arm.com py::dict d; 6611986Sandreas.sandberg@arm.com}; 6711986Sandreas.sandberg@arm.com 6812391Sjason@lowepower.comTEST_SUBMODULE(exceptions, m) { 6912391Sjason@lowepower.com m.def("throw_std_exception", []() { 7012391Sjason@lowepower.com throw std::runtime_error("This exception was intentionally thrown."); 7112391Sjason@lowepower.com }); 7212391Sjason@lowepower.com 7311986Sandreas.sandberg@arm.com // make a new custom exception and use it as a translation target 7411986Sandreas.sandberg@arm.com static py::exception<MyException> ex(m, "MyException"); 7511986Sandreas.sandberg@arm.com py::register_exception_translator([](std::exception_ptr p) { 7611986Sandreas.sandberg@arm.com try { 7711986Sandreas.sandberg@arm.com if (p) std::rethrow_exception(p); 7811986Sandreas.sandberg@arm.com } catch (const MyException &e) { 7911986Sandreas.sandberg@arm.com // Set MyException as the active python error 8011986Sandreas.sandberg@arm.com ex(e.what()); 8111986Sandreas.sandberg@arm.com } 8211986Sandreas.sandberg@arm.com }); 8311986Sandreas.sandberg@arm.com 8411986Sandreas.sandberg@arm.com // register new translator for MyException2 8511986Sandreas.sandberg@arm.com // no need to store anything here because this type will 8611986Sandreas.sandberg@arm.com // never by visible from Python 8711986Sandreas.sandberg@arm.com py::register_exception_translator([](std::exception_ptr p) { 8811986Sandreas.sandberg@arm.com try { 8911986Sandreas.sandberg@arm.com if (p) std::rethrow_exception(p); 9011986Sandreas.sandberg@arm.com } catch (const MyException2 &e) { 9111986Sandreas.sandberg@arm.com // Translate this exception to a standard RuntimeError 9211986Sandreas.sandberg@arm.com PyErr_SetString(PyExc_RuntimeError, e.what()); 9311986Sandreas.sandberg@arm.com } 9411986Sandreas.sandberg@arm.com }); 9511986Sandreas.sandberg@arm.com 9611986Sandreas.sandberg@arm.com // register new translator for MyException4 9711986Sandreas.sandberg@arm.com // which will catch it and delegate to the previously registered 9811986Sandreas.sandberg@arm.com // translator for MyException by throwing a new exception 9911986Sandreas.sandberg@arm.com py::register_exception_translator([](std::exception_ptr p) { 10011986Sandreas.sandberg@arm.com try { 10111986Sandreas.sandberg@arm.com if (p) std::rethrow_exception(p); 10211986Sandreas.sandberg@arm.com } catch (const MyException4 &e) { 10311986Sandreas.sandberg@arm.com throw MyException(e.what()); 10411986Sandreas.sandberg@arm.com } 10511986Sandreas.sandberg@arm.com }); 10611986Sandreas.sandberg@arm.com 10711986Sandreas.sandberg@arm.com // A simple exception translation: 10811986Sandreas.sandberg@arm.com auto ex5 = py::register_exception<MyException5>(m, "MyException5"); 10911986Sandreas.sandberg@arm.com // A slightly more complicated one that declares MyException5_1 as a subclass of MyException5 11011986Sandreas.sandberg@arm.com py::register_exception<MyException5_1>(m, "MyException5_1", ex5.ptr()); 11111986Sandreas.sandberg@arm.com 11212391Sjason@lowepower.com m.def("throws1", []() { throw MyException("this error should go to a custom type"); }); 11312391Sjason@lowepower.com m.def("throws2", []() { throw MyException2("this error should go to a standard Python exception"); }); 11412391Sjason@lowepower.com m.def("throws3", []() { throw MyException3("this error cannot be translated"); }); 11512391Sjason@lowepower.com m.def("throws4", []() { throw MyException4("this error is rethrown"); }); 11612391Sjason@lowepower.com m.def("throws5", []() { throw MyException5("this is a helper-defined translated exception"); }); 11712391Sjason@lowepower.com m.def("throws5_1", []() { throw MyException5_1("MyException5 subclass"); }); 11812391Sjason@lowepower.com m.def("throws_logic_error", []() { throw std::logic_error("this error should fall through to the standard handler"); }); 11912391Sjason@lowepower.com m.def("exception_matches", []() { 12012391Sjason@lowepower.com py::dict foo; 12114299Sbbruce@ucdavis.edu try { 12214299Sbbruce@ucdavis.edu // Assign to a py::object to force read access of nonexistent dict entry 12314299Sbbruce@ucdavis.edu py::object o = foo["bar"]; 12414299Sbbruce@ucdavis.edu } 12512391Sjason@lowepower.com catch (py::error_already_set& ex) { 12612391Sjason@lowepower.com if (!ex.matches(PyExc_KeyError)) throw; 12714299Sbbruce@ucdavis.edu return true; 12812391Sjason@lowepower.com } 12914299Sbbruce@ucdavis.edu return false; 13014299Sbbruce@ucdavis.edu }); 13114299Sbbruce@ucdavis.edu m.def("exception_matches_base", []() { 13214299Sbbruce@ucdavis.edu py::dict foo; 13314299Sbbruce@ucdavis.edu try { 13414299Sbbruce@ucdavis.edu // Assign to a py::object to force read access of nonexistent dict entry 13514299Sbbruce@ucdavis.edu py::object o = foo["bar"]; 13614299Sbbruce@ucdavis.edu } 13714299Sbbruce@ucdavis.edu catch (py::error_already_set &ex) { 13814299Sbbruce@ucdavis.edu if (!ex.matches(PyExc_Exception)) throw; 13914299Sbbruce@ucdavis.edu return true; 14014299Sbbruce@ucdavis.edu } 14114299Sbbruce@ucdavis.edu return false; 14214299Sbbruce@ucdavis.edu }); 14314299Sbbruce@ucdavis.edu m.def("modulenotfound_exception_matches_base", []() { 14414299Sbbruce@ucdavis.edu try { 14514299Sbbruce@ucdavis.edu // On Python >= 3.6, this raises a ModuleNotFoundError, a subclass of ImportError 14614299Sbbruce@ucdavis.edu py::module::import("nonexistent"); 14714299Sbbruce@ucdavis.edu } 14814299Sbbruce@ucdavis.edu catch (py::error_already_set &ex) { 14914299Sbbruce@ucdavis.edu if (!ex.matches(PyExc_ImportError)) throw; 15014299Sbbruce@ucdavis.edu return true; 15114299Sbbruce@ucdavis.edu } 15214299Sbbruce@ucdavis.edu return false; 15312391Sjason@lowepower.com }); 15411986Sandreas.sandberg@arm.com 15511986Sandreas.sandberg@arm.com m.def("throw_already_set", [](bool err) { 15611986Sandreas.sandberg@arm.com if (err) 15711986Sandreas.sandberg@arm.com PyErr_SetString(PyExc_ValueError, "foo"); 15811986Sandreas.sandberg@arm.com try { 15911986Sandreas.sandberg@arm.com throw py::error_already_set(); 16011986Sandreas.sandberg@arm.com } catch (const std::runtime_error& e) { 16111986Sandreas.sandberg@arm.com if ((err && e.what() != std::string("ValueError: foo")) || 16211986Sandreas.sandberg@arm.com (!err && e.what() != std::string("Unknown internal error occurred"))) 16311986Sandreas.sandberg@arm.com { 16411986Sandreas.sandberg@arm.com PyErr_Clear(); 16511986Sandreas.sandberg@arm.com throw std::runtime_error("error message mismatch"); 16611986Sandreas.sandberg@arm.com } 16711986Sandreas.sandberg@arm.com } 16811986Sandreas.sandberg@arm.com PyErr_Clear(); 16911986Sandreas.sandberg@arm.com if (err) 17011986Sandreas.sandberg@arm.com PyErr_SetString(PyExc_ValueError, "foo"); 17111986Sandreas.sandberg@arm.com throw py::error_already_set(); 17211986Sandreas.sandberg@arm.com }); 17311986Sandreas.sandberg@arm.com 17411986Sandreas.sandberg@arm.com m.def("python_call_in_destructor", [](py::dict d) { 17511986Sandreas.sandberg@arm.com try { 17611986Sandreas.sandberg@arm.com PythonCallInDestructor set_dict_in_destructor(d); 17711986Sandreas.sandberg@arm.com PyErr_SetString(PyExc_ValueError, "foo"); 17811986Sandreas.sandberg@arm.com throw py::error_already_set(); 17911986Sandreas.sandberg@arm.com } catch (const py::error_already_set&) { 18011986Sandreas.sandberg@arm.com return true; 18111986Sandreas.sandberg@arm.com } 18211986Sandreas.sandberg@arm.com return false; 18311986Sandreas.sandberg@arm.com }); 18412391Sjason@lowepower.com 18512391Sjason@lowepower.com // test_nested_throws 18612391Sjason@lowepower.com m.def("try_catch", [m](py::object exc_type, py::function f, py::args args) { 18712391Sjason@lowepower.com try { f(*args); } 18812391Sjason@lowepower.com catch (py::error_already_set &ex) { 18912391Sjason@lowepower.com if (ex.matches(exc_type)) 19012391Sjason@lowepower.com py::print(ex.what()); 19112391Sjason@lowepower.com else 19212391Sjason@lowepower.com throw; 19312391Sjason@lowepower.com } 19412391Sjason@lowepower.com }); 19512391Sjason@lowepower.com 19612391Sjason@lowepower.com} 197