https://github.com/nicholasjng/nanobind-bazel
Bazel defs and rules for building Python projects with nanobind extensions.
https://github.com/nicholasjng/nanobind-bazel
Last synced: 2 months ago
JSON representation
Bazel defs and rules for building Python projects with nanobind extensions.
- Host: GitHub
- URL: https://github.com/nicholasjng/nanobind-bazel
- Owner: nicholasjng
- License: apache-2.0
- Created: 2023-07-21T13:15:41.000Z (almost 2 years ago)
- Default Branch: master
- Last Pushed: 2024-05-28T11:17:44.000Z (12 months ago)
- Last Synced: 2024-05-29T02:48:20.274Z (12 months ago)
- Language: Starlark
- Size: 45.9 KB
- Stars: 3
- Watchers: 3
- Forks: 0
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# nanobind-bazel: Bazel build rules for C++ Python bindings with nanobind
This repo contains Bazel build defs for Python bindings created with [nanobind](https://github.com/wjakob/nanobind).
Here's the full list of exported rules:
- `nanobind_extension`, building a Python extension containing the bindings as a `*.so` file.
These extensions can be used e.g. as a `data` dependency for a `py_library` target.
- `nanobind_stubgen`, a rule pointing to a `py_binary` to create a Python stub file from a previously built `nanobind_extension`. (Available only with nanobind>=v2.0.0.)
- `nanobind_library`, a C++ library target that can be used as a dependency of a `nanobind_extension`. Directly forwards its arguments to the `cc_library` rule.
- `nanobind_shared_library`, a C++ shared library target that can be used to
produce smaller objects in scenarios with multiple independent bindings extensions. Directly forwards its arguments to the `cc_shared_library` rule.
- `nanobind_test`, a C++ test for a `nanobind_library`. Forwards its argument to a `cc_test`.
Each target is given nanobind's specific build flags, optimizations and dependencies.
## Usage with bzlmod
nanobind-bazel is published to the Bazel Central Registry (BCR). To use it, specify it as a `bazel_dep`:
```
# the major version of nanobind-bazel is equal to the major version of the internally used nanobind.
# In this case, we are building bindings with nanobind@v2.
bazel_dep(name = "nanobind_bazel", version = "2.0.0")
```
To instead use a development version, you can declare a `git_override()` dependency in your MODULE.bazel:
```
bazel_dep(name = "nanobind_bazel", version = "")
git_override(
module_name = "nanobind_bazel",
commit = "COMMIT_SHA", # replace this with the actual commit SHA you want.
remote = "https://github.com/nicholasjng/nanobind-bazel",
)
```
In local development scenarios, you can clone nanobind-bazel to your machine and then declare it as a `local_path_override()` like so:
```
bazel_dep(name = "nanobind_bazel", version = "")
local_path_override(
module_name = "nanobind_bazel",
path = "path/to/nanobind-bazel/", # replace this with the actual path.
)
```
## Bazel versions
This library relies on the ability to pass inputs to the linker in `cc_library` targets, which became available starting in Bazel 6.4.0. For this reason, the minimum Bazel version compatible with this project is Bazel 6.4.0.
In general, since Bazel 7 enabled bzlmod by default, no more intentional development efforts are made to support the workspace system.
## Licenses and acknowledgements
This library is heavily inspired by the [pybind11-bazel](https://github.com/pybind/pybind11_bazel) project, which does the same thing for pybind11.
As I have used some of the code from that repository, its [license](pybind11_bazel.LICENSE) is included here, too.
In contrast to that project, though, nanobind does not support Python interpreter embedding, and endorses a few more size-related optimizations which I have included here.
## Roadmap
- [x] First successful test, e.g. on wjakob's [nanobind example](https://github.com/wjakob/nanobind_example).
- [x] A BCR release.
- [x] A `nanobind_shared_library` target for a `cc_shared_library` using (lib)nanobind.
- [ ] Supporting custom nanobind build targets instead of the internal one.
## Contributing
I welcome all contributions.
If you encounter problems using these rules in your Bazel setup, please open an issue.
If you'd like to help maintain the project, write me a message.