build Python wheels with cibuildwheel and add to build workflow

.github/workflows/build.yml

@@ -94,3 +94,53 @@ jobs:
           --test_verbose_timeout_warnings \
           //...
       working-directory: src
+  python:
+    timeout-minutes: 30
+    strategy:
+      matrix:
+        runs-on:
+          - ubuntu-latest
+          # `large` is x86-64 and `xlarge` is AArch64.
+          - macos-latest-large
+          # macos-latest-xlarge may timeout.
+          # https://github.com/google/s2geometry/issues/409
+          - macos-latest-xlarge
+      fail-fast: false
+    runs-on: ${{ matrix.runs-on }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-tags: true
+          persist-credentials: false
+      - uses: pypa/cibuildwheel@8d2b08b68458a16aeb24b64e68a09ab1c8e82084 # v3.4.1
+        with:
+          package-dir: ./
+          output-dir: dist/
+      - uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
+        with:
+          name: dist-${{ runner.os }}-${{ runner.arch }}
+          path: ./dist/
+  python-publish:
+    if: (github.event_name == 'release') && (github.event.action == 'released')
+    needs: [python]
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      attestations: write
+    # Requires environment protection rules in GitHub Settings:
+    # Settings > Environments > pypi > Add required reviewers
+    environment:
+      name: pypi
+      url: https://pypi.org/p/s2geometry
+    steps:
+      - uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7.0.0
+        with:
+          pattern: dist*
+          path: dist/
+          merge-multiple: true
+      - uses: actions/attest-build-provenance@96278af6caaf10aea03fd8d33a09a777ca52d62f # v3.2.0
+        with:
+          subject-path: "dist/*"
+      # To upload to PyPI without a token, add this workflow file as a Trusted Publisher in the project settings on the PyPI website
+      - uses: pypa/gh-action-pypi-publish@ed0c53931b1dc9bd32cbe73a98c7f6766f8a527e # v1.13.0

.gitignore

@@ -1,3 +1,6 @@
 bazel-*
 build/
 MODULE.bazel.lock
+
+# compiled module
+src/s2geometry*

CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.18)
 
+# avoids error: aligned allocation function of type 'void *(std::size_t, std::align_val_t)' is only available on macOS 10.13 or newer
+# see https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md#macos
+set(CMAKE_OSX_DEPLOYMENT_TARGET "10.13" CACHE STRING "Minimum macOS version")
+
 project(s2-geometry
         VERSION 0.12.0)
 

pyproject.toml

@@ -29,17 +29,17 @@ content-type = "text/plain"
 [project.urls]
 Source = "https://github.com/google/s2geometry"
 
-[project.optional-dependencies]
+[dependency-groups]
 test = [
     "pytest",
 ]
 
 [build-system]
 requires = [
-    "wheel",
+    "cmake_build_extension",
     "setuptools",
     "setuptools_scm[toml]",
-    "cmake_build_extension",
+    "swig",
 ]
 build-backend = "setuptools.build_meta"
 
@@ -60,3 +60,15 @@ namespaces = false
 # The same as the default.  See #450.
 # https://setuptools-scm.readthedocs.io/en/latest/config/#setuptools_scm._config.DEFAULT_TAG_REGEX
 tag_regex = "^(?:[\\w-]+-)?(?P<version>[vV]?\\d+(?:\\.\\d+){0,2}[^\\+]*)(?:\\+.*)?$"
+
+[tool.cibuildwheel]
+# we only need to build with CPython 3.10 (because of the limited API / stable ABI)
+build = "cp310-*"
+test-groups = ["test"]
+test-requires = ["abi3audit"]
+test-command = "pytest {project}/src/python/s2geometry_test.py && abi3audit --strict --report {project}/dist/*.whl"
+
+[tool.cibuildwheel.macos]
+# delocate is not needed because BUILD_SHARED_LIBS is OFF in setup.py,
+# so all dependencies are statically linked into the extension module.
+repair-wheel-command = ""

setup.py

@@ -16,16 +16,20 @@
             # (it could be a subfolder)
             source_dir=str(Path(__file__).parent.absolute()),
             cmake_configure_options=[
-                                        # This option points CMake to the right Python interpreter, and helps
-                                        # the logic of FindPython3.cmake to find the active version
-                                        f"-DPython3_ROOT_DIR={Path(sys.prefix)}",
-                                        '-DCALL_FROM_SETUP_PY:BOOL=ON',
-                                        '-DBUILD_SHARED_LIBS:BOOL=OFF',
-                                        '-DCMAKE_POSITION_INDEPENDENT_CODE=ON',
-                                        '-DWITH_PYTHON=ON'
-                                    ]
-        )
+                # This option points CMake to the right Python interpreter, and helps
+                # the logic of FindPython3.cmake to find the active version
+                f"-DPython3_ROOT_DIR={Path(sys.prefix)}",
+                "-DCALL_FROM_SETUP_PY:BOOL=ON",
+                "-DBUILD_SHARED_LIBS:BOOL=OFF",
+                "-DCMAKE_POSITION_INDEPENDENT_CODE=ON",
+                "-DWITH_PYTHON=ON",
+                "-DBUILD_TESTS=OFF",
+                "-DFETCH_ABSEIL=ON",
+                "-DWITH_PYTHON_LIMITED_API=ON",
+            ]
+        ),
     ],
+    options={"bdist_wheel": {"py_limited_api": "cp310"}},
     cmdclass=dict(
         # Enable the CMakeExtension entries defined above
         build_ext=cmake_build_extension.BuildExtension,