/* 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 "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 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(m, "MyException5"); // A slightly more complicated one that declares MyException5_1 as a subclass of MyException5 py::register_exception(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;}); } 'n124' href='#n124'>124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579