v01

thirdparty/Pangolin/external/pybind11/tests/test_exceptions.cpp

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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} {}
+    virtual 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} {}
+    virtual 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();}
+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} {}
+    virtual 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;
+};
+
+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("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;
+    });
+
+    // 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;
+        }
+    });
+
+}