GitLab

* Fix & test for issue #4288 (unicode surrogate character in Python exception message).

* DRY `message_unavailable_exc`

* fix: add a constexpr
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

* style: pre-commit fixes
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Add option to force the use of the PYPY GIL scoped acquire/release logic to support nested gil access, see https://github.com/pybind/pybind11/issues/1276 and https://github.com/pytorch/pytorch/issues/83101



* Apply suggestions from code review

* Update CMakeLists.txt

* docs: update upgrade guide

* Update docs/upgrade.rst

* All bells & whistles.

* Add Reminder to common.h, so that we will not forget to purge `!WITH_THREAD` branches when dropping Python 3.6

* New sentence instead of semicolon.

* Temporarily pull in snapshot of PR #4246

* Add `test_release_acquire`

* Add more unit tests for nested gil locking

* Add test_report_builtins_internals_keys

* Very minor enhancement: sort list only after filtering.

* Revert change in docs/upgrade.rst

* Add test_multi_acquire_release_cross_module, while also forcing unique PYBIND11_INTERNALS_VERSION for cross_module_gil_utils.cpp

* Hopefully fix apparently new ICC error.

```
2022-10-28T07:57:54.5187728Z -- The CXX compiler identification is Intel 2021.7.0.20220726
...
2022-10-28T07:58:53.6758994Z icpc: remark #10441: The Intel(R) C++ Compiler Classic (ICC) is deprecated and will be removed from product release in the second half of 2023. The Intel(R) oneAPI DPC++/C++ Compiler (ICX) is the recommended compiler moving forward. Please transition to use this compiler. Use '-diag-disable=10441' to disable this message.
2022-10-28T07:58:54.5801597Z In file included from /home/runner/work/pybind11/pybind11/include/pybind11/detail/../detail/type_caster_base.h(15),
2022-10-28T07:58:54.5803794Z                  from /home/runner/work/pybind11/pybind11/include/pybind11/detail/../cast.h(15),
2022-10-28T07:58:54.5805740Z                  from /home/runner/work/pybind11/pybind11/include/pybind11/detail/../attr.h(14),
2022-10-28T07:58:54.5809556Z                  from /home/runner/work/pybind11/pybind11/include/pybind11/detail/class.h(12),
2022-10-28T07:58:54.5812154Z                  from /home/runner/work/pybind11/pybind11/include/pybind11/pybind11.h(13),
2022-10-28T07:58:54.5948523Z                  from /home/runner/work/pybind11/pybind11/tests/cross_module_gil_utils.cpp(13):
2022-10-28T07:58:54.5949009Z /home/runner/work/pybind11/pybind11/include/pybind11/detail/../detail/internals.h(177): error #2282: unrecognized GCC pragma
2022-10-28T07:58:54.5949374Z       PYBIND11_TLS_KEY_INIT(tstate)
2022-10-28T07:58:54.5949579Z       ^
2022-10-28T07:58:54.5949695Z
```

* clang-tidy fixes

* Workaround for PYPY WIN exitcode None

* Revert "Temporarily pull in snapshot of PR #4246"

This reverts commit 23ac16e859150f27fda25ca865cabcb4444e0770.

* Another workaround for PYPY WIN exitcode None

* Clean up how the tests are run "run in process" Part 1: uniformity

* Clean up how the tests are run "run in process" Part 2: use `@pytest.mark.parametrize` and clean up the naming.

* Skip some tests `#if defined(THREAD_SANITIZER)` (tested with TSAN using the Google-internal toolchain).

* Run all tests again but ignore ThreadSanitizer exitcode 66 (this is less likely to mask unrelated ThreadSanitizer issues in the future).

* bug fix: missing common.h include before using `PYBIND11_SIMPLE_GIL_MANAGEMENT`

For the tests in the github CI this does not matter, because
`PYBIND11_SIMPLE_GIL_MANAGEMENT` is always defined from the command line,
but when monkey-patching common.h locally, it matters.

* if process.exitcode is None: assert t_delta > 9.9

* More sophisiticated `_run_in_process()` implementation, clearly reporting `DEADLOCK`, additionally exercised via added `intentional_deadlock()`

* Wrap m.intentional_deadlock in a Python function, for `ForkingPickler` compatibility.

```
>       ForkingPickler(file, protocol).dump(obj)
E       TypeError: cannot pickle 'PyCapsule' object
```

Observed with all Windows builds including mingw but not PyPy, and macos-latest with Python 3.9, 3.10, 3.11 but not 3.6.

* Add link to potential solution for WOULD-BE-NICE-TO-HAVE feature.

* Add `SKIP_IF_DEADLOCK = True` option, to not pollute the CI results with expected `DEADLOCK` failures while we figure out what to do about them.

* Add COPY-PASTE-THIS: gdb ... command (to be used for debugging the detected deadlock)

* style: pre-commit fixes

* Do better than automatic pre-commit fixes.

* Add `PYBIND11_SIMPLE_GIL_MANAGEMENT` to `pytest_report_header()` (so that we can easily know when harvesting deadlock information from the CI logs).
Co-authored-by: Arnim Balzer <arnim@seechange.ai>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* (bugfix): Improve bytes to str decoding error handling

* regroup test

* Further broaden tests

* Add another decode error test

* Fix bug in tests

* Reviewer suggestions

* Fix casts to void*

* Improve tests

* style: pre-commit fixes

* remove c style cast
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Aaron Gokaslan <aaronGokaslan@gmail.com>

* Revert "chore: perfectly forward all make_iterator args (#3980)"

This reverts commit 8da58da5.

* Redo unrelated optimization in commit

* Add tests for ambiguous overloads

* Revert "feat: add entrypoint for cmake modules dir (#4258)"

This reverts commit 1d4a65e2.

* docs: revert changelog mention too

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* bugfix: contains now throws an exception if the key is not hashable

* Fix tests and improve robustness

* Remove todo

* Workaround PyPy corner case

* PyPy xfail

* Fix typo

* fix xfail

* Make clang-tidy happy

* Remove redundant exc checking

* Reproducer for issue encountered in smart_holder update.

* clang-tidy compatibility (untested).

* Add `enable_if_t` to workaround.

* Bug fix: Move `PYBIND11_USING_WORKAROUND_FOR_CUDA_11_4_THROUGH_8` determination to detail/common.h

So that it actually is defined in pybind11.h

* Try using the workaround (which is nicer than the original code) universally.

* Reduce reproducer for CUDA 11.7 issue encountered in smart_holder update.

This commit tested in isolation on top of current master + first version of reproducer (62311eb431849d135a5db84f6c75ec390f2ede7c).

Succeeds with Debian Clang 14.0.6 C++17 (and probably all other compilers).

Fails for CUDA 11.7:

```
cd /build/tests && /usr/local/cuda/bin/nvcc -forward-unknown-to-host-compiler -Dpybind11_tests_EXPORTS -I/mounted_pybind11/include -isystem=/usr/include/python3.10 -g --generate-code=arch=compute_52,code=[compute_52,sm_52] -Xcompiler=-fPIC -Xcompiler=-fvisibility=hidden -Werror all-warnings -std=c++17 -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o -MF CMakeFiles/pybind11_tests.dir/test_class.cpp.o.d -x cu -c /mounted_pybind11/tests/test_class.cpp -o CMakeFiles/pybind11_tests.dir/test_class.cpp.o
/mounted_pybind11/tests/test_class.cpp(53): error: more than one instance of overloaded function "pybind11::class_<type_, options...>::def [with type_=test_class::pr4220_tripped_over_this::Empty0, options=<>]" matches the argument list:
            function template "pybind11::class_<test_class::pr4220_tripped_over_this::Empty0> &pybind11::class_<type_, options...>::def(const char *, Func &&, const Extra &...) [with type_=test_class::pr4220_tripped_over_this::Empty0, options=<>]"
/mounted_pybind11/include/pybind11/pybind11.h(1557): here
            function template "pybind11::class_<test_class::pr4220_tripped_over_this::Empty0> &pybind11::class_<type_, options...>::def(const T &, const Extra &...) [with type_=test_class::pr4220_tripped_over_this::Empty0, options=<>]"
/mounted_pybind11/include/pybind11/pybind11.h(1586): here
            argument types are: (const char [8], <unknown-type>)
            object type is: pybind11::class_<test_class::pr4220_tripped_over_this::Empty0>

1 error detected in the compilation of "/mounted_pybind11/tests/test_class.cpp".
```

* fix: PyCapsule_GetDestructor is allowed to return a nullptr destructor

Previously, this code would error out if the destructor happened to be
a nullptr. This is incorrect. nullptrs are allowed for capsule
destructors.

"It is legal for a capsule to have a NULL destructor. This makes a
NULL return code somewhat ambiguous; use PyCapsule_IsValid() or
PyErr_Occurred() to disambiguate."

See:

https://docs.python.org/3/c-api/capsule.html#c.PyCapsule_GetDestructor

I noticed this while working on a type caster related to #3858 DLPack
happens to allow the destructor not to be defined on a capsule, and I
encountered such a case. See:

https://github.com/dmlc/dlpack/blob/e2bdd3bee8cb6501558042633fa59144cc8b7f5f/include/dlpack/dlpack.h#L219



* Add test for the fix.

* Update tests/test_pytypes.cpp

I tried this locally and it works!
I never knew that there are cases where `reinterpret_cast` does not work but `static_cast` does. Let's see if all compilers are happy with this.
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

* style: pre-commit fixes
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgkio@gmail.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Disable test triggering ASAN failure (to pin-point where the problem is).

* Fix unsafe "block" implementation in test_eigen.cpp

* Undo changes (i.e. revert back to master).

* Detect "type_caster for Eigen::Ref made a copy."

This is achieved without
* reaching into internals,
* making test_eigen.cpp depend on pybind11/numpy.h.

* Add comment pointing to PR, for easy reference.

This looks like it lacks a newline.

* Remove sanity check from code base.

* Use main over master.

* Better alternative that doesn't collide with language keywords/frequent usage words.

* Add debug fprintf to test_interpreter.cpp

* Update `sys.path` from `PYTHONPATH` in Python >= 3.11 branch of `initialize_interpreter()`

* Use `config.isolated = 0; config.use_environment = 1;`

As suggsted by @vstinner here: https://github.com/pybind/pybind11/pull/4119#issuecomment-1219442853



* Add `TEST_CASE("PYTHONPATH is used to update sys.path")`

* Fix clang-tidy error.

* Use `_putenv_s()` under Windows.

* Fix clang-tidy error: argument name ... in comment does not match parameter name

* Remove slash from PYTHONPATH addition, to work around Windows slash-vs-backslash issue.

* Use `py::str(...)` instead of `.attr("__str__")` as suggested by @skylion007
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

* Add some additional pytests

* Reorder tests

* Further reorder tests

* remove stray lines

* remove unused fixtures

* add installation support for pkg-config dependency detection

pkg-config is a buildsystem-agnostic alternative to
`pybind11Config.cmake` that can be used from build systems other than
cmake.

Fixes #230

* tests: add test for pkg config
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/asottile/pyupgrade: v2.37.2 → v2.37.3](https://github.com/asottile/pyupgrade/compare/v2.37.2...v2.37.3)
- [github.com/hadialqattan/pycln: v2.0.4 → v2.1.1](https://github.com/hadialqattan/pycln/compare/v2.0.4...v2.1.1)
- [github.com/PyCQA/flake8: 4.0.1 → 5.0.2](https://github.com/PyCQA/flake8/compare/4.0.1...5.0.2

)

* fix: minor touchups for flake8
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

* Add `-DPYBIND11_WERROR=ON` to mingw cmake commands (and `-DCMAKE_VERBOSE_MAKEFILE:BOOL=ON`).

* Using no-destructor idiom to side-step overzealous MINGW warning.

* Add __MINGW32__ pragma GCC diagnostic ignored in eigen.h

* Add another no-destructor workaround.

* Temporarily add -k (keep-going) flags to hopefully speed up finding all warnings.

* Revert "Temporarily add -k (keep-going) flags to hopefully speed up finding all warnings."

This reverts commit f36b0af8f93e9f6f16c969fb5b646e116f5eaf0f.

* Very minor shuffle to avoid MSVC warnings.

* Remove all `:BOOL` as suggested by @henryiii

* More systematic gcc coverage, based on https://github.com/pybind/pybind11/pull/4074#issuecomment-1188385580

* Fix complete fail.

* Resolve GCC 11 & 12 "redundant move in return statement" warnings.

* Also add clang 11, 12, 13 (to gather info for warning suppressions).

* Add & use `PYBIND11_DETECTED_CLANG_WITH_MISLEADING_CALL_STD_MOVE_EXPLICITLY_WARNING`

* For PyPy only, re-enable old behavior (likely to mask bugs), to avoid segfault with unknown root cause.

Change prompted by https://github.com/pybind/pybind11/issues/4075

* Undo the change in tests/test_exceptions.py

I turns out (I forgot) that PyPy segfaults in `test_flaky_exception_failure_point_init` already before the `MISMATCH` code path is reached:

https://github.com/pybind/pybind11/runs/7383663596

```
RPython traceback:
test_exceptions.py .......X.........Error in cpyext, CPython compatibility layer:
  File "pypy_module_cpyext.c", line 14052, in wrapper_second_level__star_3_1
  File "pypy_module_cpyext_1.c", line 35750, in not_supposed_to_fail
Fatal Python error: Segmentation fault
Stack (most recent call first, approximate line numbers):
  File "/home/runner/work/pybind11/pybind11/tests/test_exceptions.py", line 306 in test_flaky_exception_failure_point_init
The function PyErr_NormalizeException was not supposed to fail
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/python.py", line 185 in pytest_pyfunc_call
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_callers.py", line 9 in _multicall
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_manager.py", line 77 in _hookexec
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_hooks.py", line 244 in __call__
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/python.py", line 1716 in runtest
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 159 in pytest_runtest_call
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_callers.py", line 9 in _multicall
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_manager.py", line 77 in _hookexec
Fatal error in cpyext, CPython compatibility layer, calling PyErr_NormalizeException
Either report a bug or consider not using this particular extension
<SystemError object at 0x7fcc8cea6868>
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_hooks.py", line 244 in __call__
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 261 in <lambda>
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 317 in from_call
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 246 in call_runtest_hook
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 218 in call_and_report
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 118 in runtestprotocol
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/runner.py", line 110 in pytest_runtest_protocol
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_callers.py", line 9 in _multicall
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_manager.py", line 77 in _hookexec
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_hooks.py", line 244 in __call__
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/main.py", line 335 in pytest_runtestloop
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_callers.py", line 9 in _multicall
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_manager.py", line 77 in _hookexec
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_hooks.py", line 244 in __call__
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/main.py", line 318 in _main
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/main.py", line 255 in wrap_session
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/main.py", line 314 in pytest_cmdline_main
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_callers.py", line 9 in _multicall
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_manager.py", line 77 in _hookexec
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pluggy/_hooks.py", line 244 in __call__
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/config/__init__.py", line 133 in main
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/_pytest/config/__init__.py", line 181 in console_main
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/site-packages/pytest/__main__.py", line 1 in <module>
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/lib-python/3/runpy.py", line 62 in _run_code
  File "/opt/hostedtoolcache/PyPy/3.7.13/x64/lib-python/3/runpy.py", line 170 in _run_module_as_main
  File "<builtin>/app_main.py", line 109 in run_toplevel
  File "<builtin>/app_main.py", line 652 in run_command_line
  File "<builtin>/app_main.py", line 996 in entry_point
Segmentation fault (core dumped)
```

* Add test_pypy_oserror_normalization

* Disable new `PYPY_VERSION` `#if`, to verify that the new test actually fails.

* Restore PYPY_VERSION workaround and update comment to reflect what was learned.

* [ci skip] Fix trivial oversight in comment.

* Fix #3812 and fix const of inplace assignments

* Fix missing tests

* Revert operator overloading changes

* calculate answer first for tests

* Simplify tests

* Add more tests

* Add a couple more tests

* Add test_inplace_lshift, test_inplace_rshift for completeness.

* Update tests

* Shortcircuit on self assigment and address reviewer comment

* broaden skip for self assignment

* One more reviewer comment

* Document opt behavior and make consistent

* Revert unnecessary change

* Clarify comment
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>

* Disable implicit conversion from `0` to `pybind11::handle`.

* Reverse or-ed condition in an attempt to resolve GCC 8.3.0 errors (i386/debian:buster).

* Trying the simpler `std::is_same<T, PyObject *>`

* Add implicit_conversion_from_pytorch_THPObjectPtr_to_handle test.

* Accommodate types with implicit conversions to `PyObject *`, other than `handle` & `handle` subclasses, or integral types.

* Fix copy-paste mishap (picked wrong name).

* Revamp SFINAE construct to actually fix the pytorch issue (already validated against pytorch proper).

The first version of the reduced pytorch code was critically missing the move ctor. The first version of the accompanying test was meaningless.

Note: It turns out the `!std::is_arithmetic<T>` condition is not needed: `int` is not in general implicitly convertible to `PyObject *`, only the literal `0` is.

* Use `NOLINT(performance-noexcept-move-constructor)` for reduced code from the wild (rather than changing the code).

* Use any_of, all_of, negation. It turns out to clang-format nicer.

* Clean up comments for changed code.

* Reduce pytorch situation further, add test for operator ... const.

* Use `none_of` as suggested by @skylion007

* Add `pure_compile_tests_for_handle_from_PyObject_pointers()`

* Fix inconsequential oversight (retested).

* Factor our `is_pyobj_ptr_or_nullptr_t` to make the SFINAE conditions more readable.

* Remove stray line (oversight).

* Make the `pure_compile_tests_for_handle_from_PyObject_pointers()` "rhs-const-complete", too.

* Remove the temporary PYBIND11_UNDO_PR4008 `#ifdef`.

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Report `C++ Info:` from `pytest_configure()`

* Use pytest_report_header() as suggested by @skylion007

* Placeholder commit for 3.11 testing

* Does this fix it?

* Try suggestion

* Placeholder commit for 3.11 testing

* Does this fix it?

* Try suggestion

* fix: try using modern init for embedded interp
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: error message changed in 3.11

* fix: apply logic in Python manually
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix autodetect dynamic attrs in 3.11

* fix: include error message if possible in error
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* ci: enable standard Python 3.11 testing
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Make dynamic attrs condtiion exclusive to ver.
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

When converting an array to an Eigen matrix, ignore the strides if any
dimension size is 0. If the array is empty, the strides aren't relevant,
and especially numpy ≥ 1.23 explicitly sets the strides to 0 in this
case. (See numpy commit dd5ab7b11520.)

Update tests to verify that this works, and continues to work.

* enable two new clang-tidy checks

* Use better loop var for char

* error_already_set::what() is now constructed lazily

Prior to this commit throwing error_already_set was expensive due to the
eager construction of the error string (which required traversing the
Python stack). See #1853 for more context and an alternative take on the
issue.

Note that error_already_set no longer inherits from std::runtime_error
because the latter has no default constructor.

* Do not attempt to normalize if no exception occurred

This is not supported on PyPy-2.7 5.8.0.

* Extract exception name via tp_name

This is faster than dynamically looking up __name__ via GetAttrString.
Note though that the runtime of the code throwing an error_already_set
will be dominated by stack unwinding so the improvement will not be
noticeable.

Before:

396 ns ± 0.913 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

After:

277 ns ± 0.549 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

Benchmark:

const std::string foo() {
    PyErr_SetString(PyExc_KeyError, "");
    const std::string &s = py::detail::error_string();
    PyErr_Clear();
    return s;
}

PYBIND11_MODULE(foo, m) {
    m.def("foo", &::foo);
}

* Reverted error_already_set to subclass std::runtime_error

* Revert "Extract exception name via tp_name"

The implementation of __name__ is slightly more complex than that.
It handles the module name prefix, and heap-allocated types. We could
port it to pybind11 later on but for now it seems like an overkill.

This reverts commit f1435c7e6b068a1ed13ebd3db597ea3bb15aa398.

* Cosmit following @YannickJadoul's comments

Note that detail::error_string() no longer calls PyException_SetTraceback
as it is unncessary for pretty-printing the exception.

* Fixed PyPy build

* Moved normalization to error_already_set ctor

* Fix merge bugs

* Fix more merge errors

* Improve formatting

* Improve error message in rare case

* Revert back if statements

* Fix clang-tidy

* Try removing mutable

* Does build_mode release fix it

* Set to Debug to expose segfault

* Fix remove set error string

* Do not run error_string() more than once

* Trying setting the tracebackk to the value

* guard if m_type is null

* Try to debug PGI

* One last try for PGI

* Does reverting this fix PyPy

* Reviewer suggestions

* Remove unnecessary initialization

* Add noexcept move and explicit fail throw

* Optimize error_string creation

* Fix typo

* Revert noexcept

* Fix merge conflict error

* Abuse assignment operator

* Revert operator abuse

* See if we still need debug

* Remove unnecessary mutable

* Report "FATAL failure building pybind11::error_already_set error_string" and terminate process.

* Try specifying noexcept again

* Try explicit ctor

* default ctor is noexcept too

* Apply reviewer suggestions, simplify code, and make helper method private

* Remove unnecessary include

* Clang-Tidy fix

* detail::obj_class_name(), fprintf with [STDERR], [STDOUT] tags, polish comments

* consistently check m_lazy_what.empty() also in production builds

* Make a comment slightly less ambiguous.

* Bug fix: Remove `what();` from `restore()`.

It sure would need to be guarded by `if (m_type)`, otherwise `what()` fails and masks that no error was set (see update unit test). But since `error_already_set` is copyable, there is no point in releasing m_type, m_value, m_trace, therefore we can just as well avoid the runtime overhead of force-building `m_lazy_what`, it may never be used.

* Replace extremely opaque (unhelpful) error message with a truthful reflection of what we know.

* Fix clang-tidy error [performance-move-constructor-init].

* Make expected error message less specific.

* Various changes.

* bug fix: error_string(PyObject **, ...)

* Putting back the two eager PyErr_NormalizeException() calls.

* Change error_already_set() to call pybind11_fail() if the Python error indicator not set. The net result is that a std::runtime_error is thrown instead of error_already_set, but all tests pass as is.

* Remove mutable (fixes oversight in the previous commit).

* Normalize the exception only locally in error_string(). Python 3.6 & 3.7 test failures expected. This is meant for benchmarking, to determine if it is worth the trouble looking into the failures.

* clang-tidy: use auto

* Use `gil_scoped_acquire_local` in `error_already_set` destructor. See long comment.

* For Python < 3.8: `PyErr_NormalizeException` before `PyErr_WriteUnraisable`

* Go back to replacing the held Python exception with then normalized exception, if & when needed. Consistently document the side-effect.

* Slightly rewording comment. (There were also other failures.)

* Add 1-line comment for obj_class_name()

* Benchmark code, with results in this commit message.

          function                   #calls  test time [s]  μs / call
master    pure_unwind                729540      1.061      14.539876
          err_set_unwind_err_clear   681476      1.040      15.260282
          err_set_error_already_set  508038      1.049      20.640525
          error_already_set_restore  555578      1.052      18.933288
          pr1895_original_foo        244113      1.050      43.018168
                                                                       PR / master
PR #1895  pure_unwind                736981      1.054      14.295685       98.32%
          err_set_unwind_err_clear   685820      1.045      15.237399       99.85%
          err_set_error_already_set  661374      1.046      15.811879       76.61%
          error_already_set_restore  669881      1.048      15.645176       82.63%
          pr1895_original_foo        318243      1.059      33.290806       77.39%

master @ commit ad146b2a

Running tests in directory "/usr/local/google/home/rwgk/forked/pybind11/tests":
============================= test session starts ==============================
platform linux -- Python 3.9.10, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /usr/local/google/home/rwgk/forked/pybind11/tests, configfile: pytest.ini
collecting ... collected 5 items

test_perf_error_already_set.py::test_perf[pure_unwind]
PERF pure_unwind,729540,1.061,14.539876
PASSED
test_perf_error_already_set.py::test_perf[err_set_unwind_err_clear]
PERF err_set_unwind_err_clear,681476,1.040,15.260282
PASSED
test_perf_error_already_set.py::test_perf[err_set_error_already_set]
PERF err_set_error_already_set,508038,1.049,20.640525
PASSED
test_perf_error_already_set.py::test_perf[error_already_set_restore]
PERF error_already_set_restore,555578,1.052,18.933288
PASSED
test_perf_error_already_set.py::test_perf[pr1895_original_foo]
PERF pr1895_original_foo,244113,1.050,43.018168
PASSED

============================== 5 passed in 12.38s ==============================

pr1895 @ commit 8dff51d12e4af11aff415ee966070368fe606664

Running tests in directory "/usr/local/google/home/rwgk/forked/pybind11/tests":
============================= test session starts ==============================
platform linux -- Python 3.9.10, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /usr/local/google/home/rwgk/forked/pybind11/tests, configfile: pytest.ini
collecting ... collected 5 items

test_perf_error_already_set.py::test_perf[pure_unwind]
PERF pure_unwind,736981,1.054,14.295685
PASSED
test_perf_error_already_set.py::test_perf[err_set_unwind_err_clear]
PERF err_set_unwind_err_clear,685820,1.045,15.237399
PASSED
test_perf_error_already_set.py::test_perf[err_set_error_already_set]
PERF err_set_error_already_set,661374,1.046,15.811879
PASSED
test_perf_error_already_set.py::test_perf[error_already_set_restore]
PERF error_already_set_restore,669881,1.048,15.645176
PASSED
test_perf_error_already_set.py::test_perf[pr1895_original_foo]
PERF pr1895_original_foo,318243,1.059,33.290806
PASSED

============================== 5 passed in 12.40s ==============================

clang++ -o pybind11/tests/test_perf_error_already_set.os -c -std=c++17 -fPIC -fvisibility=hidden -Os -flto -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wnon-virtual-dtor -Wunused-result -isystem /usr/include/python3.9 -isystem /usr/include/eigen3 -DPYBIND11_STRICT_ASSERTS_CLASS_HOLDER_VS_TYPE_CASTER_MIX -DPYBIND11_TEST_BOOST -Ipybind11/include -I/usr/local/google/home/rwgk/forked/pybind11/include -I/usr/local/google/home/rwgk/clone/pybind11/include /usr/local/google/home/rwgk/forked/pybind11/tests/test_perf_error_already_set.cpp

clang++ -o lib/pybind11_tests.so -shared -fPIC -Os -flto -shared ...

Debian clang version 13.0.1-3+build2
Target: x86_64-pc-linux-gnu
Thread model: posix

* Changing call_repetitions_target_elapsed_secs to 0.1 for regular unit testing.

* Adding in `recursion_depth`

* Optimized ctor

* Fix silly bug in recurse_first_then_call()

* Add tests that have equivalent PyErr_Fetch(), PyErr_Restore() but no try-catch.

* Add call_error_string to tests. Sample only recursion_depth 0, 100.

* Show lazy-what speed-up in percent.

* Include real_work in benchmarks.

* Replace all PyErr_SetString() with generate_python_exception_with_traceback()

* Better organization of test loops.

* Add test_error_already_set_copy_move

* Fix bug in newly added test (discovered by clang-tidy): actually use move ctor

* MSVC detects the unreachable return

* change test_perf_error_already_set.py back to quick mode

* Inherit from std::exception (instead of std::runtime_error, which does not make sense anymore with the lazy what)

* Special handling under Windows.

* print with leading newline

* Removing test_perf_error_already_set (copies are under https://github.com/rwgk/rwgk_tbx/commit/7765113fbb659e1ea004c5ba24fb578244bc6cfd).

* Avoid gil and scope overhead if there is nothing to release.

* Restore default move ctor. "member function" instead of "function" (note that "method" is Python terminology).

* Delete error_already_set copy ctor.

* Make restore() non-const again to resolve clang-tidy failure (still experimenting).

* Bring back error_already_set copy ctor, to see if that resolves the 4 MSVC test failures.

* Add noexcept to error_already_set copy & move ctors (as suggested by @skylion007 IIUC).

* Trying one-by-one noexcept copy ctor for old compilers.

* Add back test covering copy ctor. Add another simple test that exercises the copy ctor.

* Exclude more older compilers from using the noexcept = default ctors. (The tests in the previous commit exposed that those are broken.)

* Factor out & reuse gil_scoped_acquire_local as gil_scoped_acquire_simple

* Guard gil_scoped_acquire_simple by _Py_IsFinalizing() check.

* what() GIL safety

* clang-tidy & Python 3.6 fixes

* Use `gil_scoped_acquire` in dtor, copy ctor, `what()`. Remove `_Py_IsFinalizing()` checks (they are racy: https://github.com/python/cpython/pull/28525).

* Remove error_scope from copy ctor.

* Add `error_scope` to `get_internals()`, to cover the situation that `get_internals()` is called from the `error_already_set` dtor while a new Python error is in flight already. Also backing out `gil_scoped_acquire_simple` change.

* Add `FlakyException` tests with failure triggers in `__init__` and `__str__`

THIS IS STILL A WORK IN PROGRESS. This commit is only an important resting point.

This commit is a first attempt at addressing the observation that `PyErr_NormalizeException()` completely replaces the original exception if `__init__` fails. This can be very confusing even in small applications, and extremely confusing in large ones.

* Tweaks to resolve Py 3.6 and PyPy CI failures.

* Normalize Python exception immediately in error_already_set ctor.

For background see: https://github.com/pybind/pybind11/pull/1895#issuecomment-1135304081



* Fix oversights based on CI failures (copy & move ctor initialization).

* Move @pytest.mark.xfail("env.PYPY") after @pytest.mark.parametrize(...)

* Use @pytest.mark.skipif (xfail does not work for segfaults, of course).

* Remove unused obj_class_name_or() function (it was added only under this PR).

* Remove already obsolete C++ comments and code that were added only under this PR.

* Slightly better (newly added) comments.

* Factor out detail::error_fetch_and_normalize. Preparation for producing identical results from error_already_set::what() and detail::error_string(). Note that this is a very conservative refactoring. It would be much better to first move detail::error_string into detail/error_string.h

* Copy most of error_string() code to new error_fetch_and_normalize::complete_lazy_error_string()

* Remove all error_string() code from detail/type_caster_base.h. Note that this commit includes a subtle bug fix: previously error_string() restored the Python error, which will upset pybind11_fail(). This never was a problem in practice because the two PyType_Ready() calls in detail/class.h do not usually fail.

* Return const std::string& instead of const char * and move error_string() to pytypes.h

* Remove gil_scope_acquire from error_fetch_and_normalize, add back to error_already_set

* Better handling of FlakyException __str__ failure.

* Move error_fetch_and_normalize::complete_lazy_error_string() implementation from pybind11.h to pytypes.h

* Add error_fetch_and_normalize::release_py_object_references() and use from error_already_set dtor.

* Use shared_ptr for m_fetched_error => 1. non-racy, copy ctor that does not need the GIL; 2. enables guard against duplicate restore() calls.

* Add comments.

* Trivial renaming of a newly introduced member function.

* Workaround for PyPy

* Bug fix (oversight). Only valgrind got this one.

* Use shared_ptr custom deleter for m_fetched_error in error_already_set. This enables removing the dtor, copy ctor, move ctor completely.

* Further small simplification. With the GIL held, simply deleting the raw_ptr takes care of everything.

* IWYU cleanup

```
iwyu version: include-what-you-use 0.17 based on Debian clang version 13.0.1-3+build2
```

Command used:

```
iwyu -c -std=c++17 -DPYBIND11_TEST_BOOST -Iinclude/pybind11 -I/usr/include/python3.9 -I/usr/include/eigen3 include/pybind11/pytypes.cpp
```

pytypes.cpp is a temporary file: `#include "pytypes.h"`

The raw output is very long and noisy.

I decided to use `#include <cstddef>` instead of `#include <cstdio>` for `std::size_t` (iwyu sticks to the manual choice).

I ignored all iwyu suggestions that are indirectly covered by `#include <Python.h>`.

I manually verified that all added includes are actually needed.
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>

* Add object rvalue overload for accessors. Enables reference stealing

* Fix comments

* Fix more comment typos

* Fix bug

* reorder declarations for clarity

* fix another perf bug

* should be static

* future proof operator overloads

* Fix perfect forwarding

* Add a couple of tests

* Remove errant include

* Improve test documentation

* Add dict test

* add object attr tests

* Optimize STL map caster and cleanup enum

* Reorder to match declarations

* adjust increfs

* Remove comment

* revert value change

* add missing move

* Add test_perf_accessors (to be merged into test_pytypes).

* Python < 3.8 f-string compatibility

* Use thread_local in inc_ref_counter()

* Intentional breakage, brute-force way to quickly find out how many platforms reach the PYBIND11_HANDLE_REF_DEBUG code, with and without threads.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove Intentional breakage

* Drop perf test, move inc_refs tests to test_pytypes

* Fold in PR #3970 with `#ifdef`s

* Complete test coverage for all newly added code.

* Condense new unit tests via a simple local helper macro.

* Remove PYBIND11_PR3970 define. See https://github.com/pybind/pybind11/pull/3977#issuecomment-1142526417



* Move static keyword first (fixes silly oversight).
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Add `error_scope` to `detail::get_internals()`

* Adjust test to tolerate macOS PyPy behavior.

* Add missing error handling to module_::def_submodule

* Add test_def_submodule_failures

* PyPy only: Skip test with trigger for PyModule_GetName() failure.

* Reapply minor fix that accidentally got lost in transfer from PR #3964

* Replace import numpy catch (...) with catch (error_already_set)

* Add missing const (not sure how those got lost).

* Add error_already_set_what what tests, asserting the status quo.

* Move PyErr_NormalizeException() up a few lines.

* @pytest.mark.skipif("env.PYPY") from PR #1895 is required even for this much simpler PR

* Move PyException_SetTraceback() with PyErr_NormalizeException() as suggested by @skylion007

* Insert a std::move() as suggested by @skylion007

* Don't return pointers to static objects with return_value_policy::take_ownership.

This fixes -Wfree-nonheap-object warnings produced by GCC.

* Use return value policy fix instead
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

* ci: fix cuda issue

* ci: cuda 11.3-11.4 produce warnings -> errors

* tests: ignore unused warning for MSVC

* Update tests/CMakeLists.txt

* Fix py::cast from pytype rvalue to pytype

Previously, py::cast blindly assumed that the destination type was a C++
type rather than a python type when the source type was an rvalue.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Add frozenset, and allow it cast to std::set

For the reverse direction, std::set still casts to set. This is in concordance with the behavior for sequence containers, where e.g. tuple casts to std::vector but std::vector casts to list.

Extracted from #3886.

* Rename set_base to any_set to match Python C API

since this will be part of pybind11 public API

* PR: static_cast, anyset

* Add tests for frozenset

and rename anyset methods

* Remove frozenset default ctor, add tests

Making frozenset non-default constructible means that we need to adjust pyobject_caster to not require that its value is default constructible, by initializing value to a nil handle.  This also allows writing C++ functions taking anyset, and is arguably a performance improvement, since there is no need to allocate an object that will just be replaced by load.

Add some more tests, including anyset::empty, anyset::size, set::add and set::clear.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci



* Add rationale to `pyobject_caster` default ctor

* Remove ineffectual protected: access control
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>