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/*
tests/test_custom-exceptions.cpp -- exception translation
Copyright (c) 2016 Pim Schellart <P.Schellart@princeton.edu>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#include "pybind11_tests.h"
// 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 = "";
};
// 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;
};
struct PythonCallInDestructor {
PythonCallInDestructor(const py::dict &d) : d(d) {}
~PythonCallInDestructor() { d["good"] = true; }
py::dict d;
};
struct PythonAlreadySetInDestructor {
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;
};
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<MyException> ex(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
ex(e.what());
}
});
// 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
PyErr_SetString(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<MyException5>(m, "MyException5");
// A slightly more complicated one that declares MyException5_1 as a subclass of MyException5
py::register_exception<MyException5_1>(m, "MyException5_1", ex5.ptr());
m.def("throws1", []() { throw MyException("this error should go to a custom type"); });
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("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("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)
PyErr_SetString(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("Unknown internal error occurred")))
{
PyErr_Clear();
throw std::runtime_error("error message mismatch");
}
}
PyErr_Clear();
if (err)
PyErr_SetString(PyExc_ValueError, "foo");
throw py::error_already_set();
});
m.def("python_call_in_destructor", [](py::dict d) {
try {
PythonCallInDestructor set_dict_in_destructor(d);
PyErr_SetString(PyExc_ValueError, "foo");
throw py::error_already_set();
} catch (const py::error_already_set&) {
return true;
}
return false;
});
m.def("python_alreadyset_in_destructor", [](py::str s) {
PythonAlreadySetInDestructor alreadyset_in_destructor(s);
return true;
});
// test_nested_throws
m.def("try_catch", [m](py::object exc_type, py::function f, py::args args) {
try { f(*args); }
catch (py::error_already_set &ex) {
if (ex.matches(exc_type))
py::print(ex.what());
else
throw;
}
});
// Test repr that cannot be displayed
m.def("simple_bool_passthrough", [](bool x) {return x;});
}
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