Seamless operability between C++11 and Python
Go to file
Ralf W. Grosse-Kunstleve 3e419485c3
PYBIND11_PLATFORM_ABI_ID Modernization Continued (platforms other than MSVC) (#5439)
* THIS IS JUST A START: First attempt to combine information from PR #4953 and PR #5437

* Include GXX_ABI and USE_CXX in the identifier

Further constrain to GXX_ABI 1002 or greater and less than 2000,
hopefully future proof by summarizing that as `1` along with CXX11 on or
off.

* style: pre-commit fixes

* Use `gxx_abi_1xxx` and simplify the Clang string

After discussions with Ralf Grosse-Kunstleve we think these would make
good identifiers that are concise and clear.

* Error if `_GLIBCXX_USE_CXX11_ABI` is not defined

Within the `__GXX_ABI_VERSION` block this should always be defined,
guard against unexpected defines and make the error obvious.

* Change `usecxx11` to `use_cxx11_abi` for correspondence with `_GLIBCXX_USE_CXX11_ABI` (similarly to `gxx_abi` for `__GXX_ABI_VERSION`).

* `PYBIND11_COMPILER_TYPE` overhaul, mainly: replace `_icc`, `_clang`, `_gcc` with `_system`

* Add NVHPC (__PGI) to the list of compilers compatible with system compiler.

See comment by @robertmaynard: https://github.com/pybind/pybind11/pull/5439#issuecomment-2498839010

* Fix oversight: remove __NVCOMPILER elif branch in PYBIND11_BUILD_ABI block.

Also add comment pointing to this PR (#5439).

* Revert "Fix oversight: remove __NVCOMPILER elif branch in PYBIND11_BUILD_ABI block."

This reverts commit d412303e72.

* Revert "Add NVHPC (__PGI) to the list of compilers compatible with system compiler."

This reverts commit 9fc9515885.

* Define NVHPC PYBIND11_BUILD_ABI using __GNUC__, __GNUC_MINOR__, _GLIBCXX_USE_CXX11_ABI

* Use _GLIBCXX_USE_CXX11_ABI to detect libstdc++, then assume that NVHPC is always in the 1xxx ABI family.

* Enhance NVHPC comment and limited future proofing.

* The `PYBIND11_STDLIB` is obsolete but kept around to maintain backward compatibility.

* Move `PYBIND11_BUILD_TYPE` down in the file, so that the order of macro definitions is the same as in the list defining `PYBIND11_PLATFORM_ABI_ID`

* Introduce `PYBIND11_COMPILER_TYPE_LEADING_UNDERSCORE`:

This makes it possible to achieve these two goals:

* Avoid the leading underscore in `PYBIND11_PLATFORM_ABI_ID` (see https://github.com/pybind/pybind11/pull/5439#issuecomment-2503762161)

* Maintain backward compatibility for use cases as reported under https://github.com/pybind/pybind11/pull/5439#issuecomment-2510212677

`PYBIND11_INTERNALS_KIND` is removed in this commit to ensure that `PYBIND11_COMPILER_TYPE` is the first element of the `PYBIND11_PLATFORM_ABI_ID`, so that `PYBIND11_COMPILER_TYPE_LEADING_UNDERSCORE` can meaningfully be used as a prefix for `PYBIND11_PLATFORM_ABI_ID` in pybind11/detail/internals.h.

* Apply suggestion by @isuruf, with revised comments (code is as suggested).

* Make determination of `PYBIND11_COMPILER_TYPE` `"macos"` or `"glibc"` more general.

The main motivation is to resolve these "Manylinux on 🐍 3.13t • GIL" and "Pyodide wheel" failures:

```
/__w/pybind11/pybind11/include/pybind11/conduit/pybind11_platform_abi_id.h:35:10: error: #error "Unknown PYBIND11_COMPILER_TYPE: PLEASE REVISE THIS CODE."
   35 | #        error "Unknown PYBIND11_COMPILER_TYPE: PLEASE REVISE THIS CODE."
      |          ^~~~~
```

(All other CI jobs succeeded.)

Further thought:

Essentially, under Linux and macOS the `PYBIND11_COMPILER_TYPE` is only for informational purposes.
ABI compatibility is determined by the libstdc++ or libc++ ABI version.

* Add `PYBIND11_COMPILER_TYPE` `emscripten`

* Add `PYBIND11_COMPILER_TYPE` `graalvm`

* Revert "Add `PYBIND11_COMPILER_TYPE` `graalvm`"

This reverts commit 75da5fbfd9.

* Revert "Add `PYBIND11_COMPILER_TYPE` `emscripten`"

This reverts commit e34dc8b511.

* Revert "Make determination of `PYBIND11_COMPILER_TYPE` `"macos"` or `"glibc"` more general."

This reverts commit 41daaa41fa.

* Revert "Apply suggestion by @isuruf, with revised comments (code is as suggested)."

This reverts commit ca9e6990de.

* Remove `defined(__INTEL_COMPILER)` as suggested by @hpkfft under https://github.com/pybind/pybind11/pull/5439#discussion_r1889156543

---------

Co-authored-by: Marcus D. Hanwell <marcus@cryos.net>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2024-12-20 01:39:32 -08:00
.github Drop Clang dev CI job (#5464) 2024-12-12 11:15:21 -08:00
docs chore(deps): update pre-commit hooks (#5459) 2024-12-08 15:21:49 -08:00
include/pybind11 PYBIND11_PLATFORM_ABI_ID Modernization Continued (platforms other than MSVC) (#5439) 2024-12-20 01:39:32 -08:00
pybind11 fix: escape paths with spaces in pybind11-config (#4874) 2024-08-14 17:25:37 -04:00
tests Option for arg/return type hints and correct typing for std::filesystem::path (#5450) 2024-12-08 11:30:49 -08:00
tools chore(deps): update pre-commit hooks (#5459) 2024-12-08 15:21:49 -08:00
.appveyor.yml feat: remove Python 3.6 support (#5177) 2024-06-22 00:55:00 -04:00
.clang-format Final manual curation in preparation for global clang-formating (#3712) 2022-02-10 11:42:03 -08:00
.clang-tidy clang-tidy upgrade (to version 18) (#5272) 2024-07-29 11:10:03 -07:00
.cmake-format.yaml format: apply cmake-format 2020-07-30 20:27:55 -04:00
.codespell-ignore-lines [pre-commit.ci] pre-commit autoupdate (#4151) 2022-08-29 21:59:48 -07:00
.gitattributes style: pylint (#3720) 2022-02-15 17:48:33 -05:00
.gitignore First draft of Eigen::Tensor support (#4201) 2022-10-18 16:54:16 -07:00
.pre-commit-config.yaml chore(deps): update pre-commit hooks (#5459) 2024-12-08 15:21:49 -08:00
.readthedocs.yml [ci skip] Adopt nanobind config. (#4792) 2023-08-15 07:02:54 -07:00
CMakeLists.txt Factor out pybind11/conduit/pybind11_platform_abi_id.h (#5375) 2024-11-10 12:17:35 -08:00
LICENSE docs: contrib/issue templates (#2377) 2020-08-17 10:14:23 -04:00
MANIFEST.in Create s Security Policy (#4671) 2023-05-23 10:05:25 -07:00
noxfile.py chore: prepare for 2.13.0 (#5198) 2024-06-25 23:51:27 -04:00
pyproject.toml chore(deps): update pre-commit hooks (#5459) 2024-12-08 15:21:49 -08:00
README.rst feat: remove Python 3.7 support (#5191) 2024-07-30 09:18:35 -07:00
SECURITY.md Create s Security Policy (#4671) 2023-05-23 10:05:25 -07:00
setup.cfg feat: remove Python 3.7 support (#5191) 2024-07-30 09:18:35 -07:00
setup.py feat: remove Python 3.6 support (#5177) 2024-06-22 00:55:00 -04:00

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

.. figure:: https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png
   :alt: pybind11 logo

**pybind11 — Seamless operability between C++11 and Python**

|Latest Documentation Status| |Stable Documentation Status| |Gitter chat| |GitHub Discussions| |CI| |Build status|

|Repology| |PyPI package| |Conda-forge| |Python Versions|

`Setuptools example <https://github.com/pybind/python_example>`_
• `Scikit-build example <https://github.com/pybind/scikit_build_example>`_
• `CMake example <https://github.com/pybind/cmake_example>`_

.. start


**pybind11** is a lightweight header-only library that exposes C++ types
in Python and vice versa, mainly to create Python bindings of existing
C++ code. Its goals and syntax are similar to the excellent
`Boost.Python <http://www.boost.org/doc/libs/1_58_0/libs/python/doc/>`_
library by David Abrahams: to minimize boilerplate code in traditional
extension modules by inferring type information using compile-time
introspection.

The main issue with Boost.Python—and the reason for creating such a
similar project—is Boost. Boost is an enormously large and complex suite
of utility libraries that works with almost every C++ compiler in
existence. This compatibility has its cost: arcane template tricks and
workarounds are necessary to support the oldest and buggiest of compiler
specimens. Now that C++11-compatible compilers are widely available,
this heavy machinery has become an excessively large and unnecessary
dependency.

Think of this library as a tiny self-contained version of Boost.Python
with everything stripped away that isn't relevant for binding
generation. Without comments, the core header files only require ~4K
lines of code and depend on Python (3.8+, or PyPy) and the C++
standard library. This compact implementation was possible thanks to
some C++11 language features (specifically: tuples, lambda functions and
variadic templates). Since its creation, this library has grown beyond
Boost.Python in many ways, leading to dramatically simpler binding code in many
common situations.

Tutorial and reference documentation is provided at
`pybind11.readthedocs.io <https://pybind11.readthedocs.io/en/latest>`_.
A PDF version of the manual is available
`here <https://pybind11.readthedocs.io/_/downloads/en/latest/pdf/>`_.
And the source code is always available at
`github.com/pybind/pybind11 <https://github.com/pybind/pybind11>`_.


Core features
-------------


pybind11 can map the following core C++ features to Python:

- Functions accepting and returning custom data structures per value,
  reference, or pointer
- Instance methods and static methods
- Overloaded functions
- Instance attributes and static attributes
- Arbitrary exception types
- Enumerations
- Callbacks
- Iterators and ranges
- Custom operators
- Single and multiple inheritance
- STL data structures
- Smart pointers with reference counting like ``std::shared_ptr``
- Internal references with correct reference counting
- C++ classes with virtual (and pure virtual) methods can be extended
  in Python
- Integrated NumPy support (NumPy 2 requires pybind11 2.12+)

Goodies
-------

In addition to the core functionality, pybind11 provides some extra
goodies:

- Python 3.8+, and PyPy3 7.3 are supported with an implementation-agnostic
  interface (pybind11 2.9 was the last version to support Python 2 and 3.5).

- It is possible to bind C++11 lambda functions with captured
  variables. The lambda capture data is stored inside the resulting
  Python function object.

- pybind11 uses C++11 move constructors and move assignment operators
  whenever possible to efficiently transfer custom data types.

- It's easy to expose the internal storage of custom data types through
  Pythons' buffer protocols. This is handy e.g. for fast conversion
  between C++ matrix classes like Eigen and NumPy without expensive
  copy operations.

- pybind11 can automatically vectorize functions so that they are
  transparently applied to all entries of one or more NumPy array
  arguments.

- Python's slice-based access and assignment operations can be
  supported with just a few lines of code.

- Everything is contained in just a few header files; there is no need
  to link against any additional libraries.

- Binaries are generally smaller by a factor of at least 2 compared to
  equivalent bindings generated by Boost.Python. A recent pybind11
  conversion of PyRosetta, an enormous Boost.Python binding project,
  `reported <https://graylab.jhu.edu/Sergey/2016.RosettaCon/PyRosetta-4.pdf>`_
  a binary size reduction of **5.4x** and compile time reduction by
  **5.8x**.

- Function signatures are precomputed at compile time (using
  ``constexpr``), leading to smaller binaries.

- With little extra effort, C++ types can be pickled and unpickled
  similar to regular Python objects.

Supported compilers
-------------------

1. Clang/LLVM 3.3 or newer (for Apple Xcode's clang, this is 5.0.0 or
   newer)
2. GCC 4.8 or newer
3. Microsoft Visual Studio 2017 or newer
4. Intel classic C++ compiler 18 or newer (ICC 20.2 tested in CI)
5. Cygwin/GCC (previously tested on 2.5.1)
6. NVCC (CUDA 11.0 tested in CI)
7. NVIDIA PGI (20.9 tested in CI)

About
-----

This project was created by `Wenzel
Jakob <http://rgl.epfl.ch/people/wjakob>`_. Significant features and/or
improvements to the code were contributed by Jonas Adler, Lori A. Burns,
Sylvain Corlay, Eric Cousineau, Aaron Gokaslan, Ralf Grosse-Kunstleve, Trent Houliston, Axel
Huebl, @hulucc, Yannick Jadoul, Sergey Lyskov, Johan Mabille, Tomasz Miąsko,
Dean Moldovan, Ben Pritchard, Jason Rhinelander, Boris Schäling, Pim
Schellart, Henry Schreiner, Ivan Smirnov, Boris Staletic, and Patrick Stewart.

We thank Google for a generous financial contribution to the continuous
integration infrastructure used by this project.


Contributing
~~~~~~~~~~~~

See the `contributing
guide <https://github.com/pybind/pybind11/blob/master/.github/CONTRIBUTING.md>`_
for information on building and contributing to pybind11.

License
~~~~~~~

pybind11 is provided under a BSD-style license that can be found in the
`LICENSE <https://github.com/pybind/pybind11/blob/master/LICENSE>`_
file. By using, distributing, or contributing to this project, you agree
to the terms and conditions of this license.

.. |Latest Documentation Status| image:: https://readthedocs.org/projects/pybind11/badge?version=latest
   :target: http://pybind11.readthedocs.org/en/latest
.. |Stable Documentation Status| image:: https://img.shields.io/badge/docs-stable-blue.svg
   :target: http://pybind11.readthedocs.org/en/stable
.. |Gitter chat| image:: https://img.shields.io/gitter/room/gitterHQ/gitter.svg
   :target: https://gitter.im/pybind/Lobby
.. |CI| image:: https://github.com/pybind/pybind11/workflows/CI/badge.svg
   :target: https://github.com/pybind/pybind11/actions
.. |Build status| image:: https://ci.appveyor.com/api/projects/status/riaj54pn4h08xy40?svg=true
   :target: https://ci.appveyor.com/project/wjakob/pybind11
.. |PyPI package| image:: https://img.shields.io/pypi/v/pybind11.svg
   :target: https://pypi.org/project/pybind11/
.. |Conda-forge| image:: https://img.shields.io/conda/vn/conda-forge/pybind11.svg
   :target: https://github.com/conda-forge/pybind11-feedstock
.. |Repology| image:: https://repology.org/badge/latest-versions/python:pybind11.svg
   :target: https://repology.org/project/python:pybind11/versions
.. |Python Versions| image:: https://img.shields.io/pypi/pyversions/pybind11.svg
   :target: https://pypi.org/project/pybind11/
.. |GitHub Discussions| image:: https://img.shields.io/static/v1?label=Discussions&message=Ask&color=blue&logo=github
   :target: https://github.com/pybind/pybind11/discussions