From a90d5e228923117313913862aca587c668f7beec Mon Sep 17 00:00:00 2001
From: Sebastian Ramacher <sebastian@ramacher.at>
Date: Sat, 1 Nov 2025 17:51:25 +0100
Subject: [PATCH] Supported builds with limited API

---
 .github/workflows/build.yaml         | 30 +++++++++++++++++++++++++++-
 .github/workflows/publish-twine.yaml |  4 ++--
 README.md                            |  5 ++++-
 pyproject.toml                       |  2 +-
 setup.py                             | 11 ++++++++++
 5 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 0e01d96..8a0f19b 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -25,7 +25,35 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install setuptools "cython >= 3" pytest
+        pip install setuptools "cython >= 3.1" pytest
+    - name: Build with Python ${{ matrix.python-version }}
+      run: |
+        python setup.py build
+        python setup.py build_ext -i
+    - name: Test with pytest
+      run: |
+        pytest
+      env:
+        LC_ALL: C.UTF-8
+        LANG: C.UTF-8
+
+  build-limited-api:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    env:
+      USE_LIMITED_API: "1"
+    steps:
+    - uses: actions/checkout@v5
+    - name: Set up Python
+      uses: actions/setup-python@v6
+        python-version: "3.x"
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install setuptools "cython >= 3.1" pytest
     - name: Build with Python ${{ matrix.python-version }}
       run: |
         python setup.py build
diff --git a/.github/workflows/publish-twine.yaml b/.github/workflows/publish-twine.yaml
index 28193c7..8ce6667 100644
--- a/.github/workflows/publish-twine.yaml
+++ b/.github/workflows/publish-twine.yaml
@@ -23,7 +23,7 @@ jobs:
       - name: Install cibuildwheel
         run: |
           python -m pip install --upgrade pip
-          python -m pip install cibuildwheel
+          python -m pip install "cython >= 3.1" cibuildwheel
       - name: Build wheels
         run: |
           python -m cibuildwheel --output-dir dist
@@ -46,7 +46,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install setuptools "cython >= 3"
+        pip install setuptools "cython >= 3.1"
     - name: Build sdist
       run: |
         python setup.py build
diff --git a/README.md b/README.md
index ea66a16..9a4df24 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ functionality.
 
 ## Dependencies
 
-* `Cython >= 3` (optional, only for building). If Cython is not available, the C files are not
+* `Cython >= 3.1` (optional, only for building). If Cython is not available, the C files are not
   regenerated from their source.
 
 ## Quick installation guide
@@ -25,6 +25,9 @@ or by running:
 python3 setup.py install
 ```
 
+In case the extension should be built with the limited Python API, set the environment variable
+`USE_LIMITED_API` to any value.
+
 ## Usage
 
 ```python3
diff --git a/pyproject.toml b/pyproject.toml
index 0da637b..7b5a73a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [build-system]
 requires = [
   "setuptools >= 43",
-  "Cython >= 3",
+  "Cython >= 3.1",
 ]
 build-backend = "setuptools.build_meta"
 
diff --git a/setup.py b/setup.py
index 420b1e9..5b493de 100644
--- a/setup.py
+++ b/setup.py
@@ -1,9 +1,13 @@
 #!/usr/bin/python3
 
+import os
 import platform
 from setuptools import setup, Extension
 
 
+use_limited_api = "USE_LIMITED_API" in os.environ
+
+
 extension_sources = ["cwcwidth/_impl.pyx"]
 define_macros = []
 if platform.system() == "Windows":
@@ -12,11 +16,17 @@ if platform.system() == "Windows":
         ("USE_MK_WCWIDTH", None),
     )
 
+options = {}
+if use_limited_api:
+    define_macros.append(("Py_LIMITED_API", 0x030B0000))  # 3.11
+    options["bdist_wheel"] = {"py_limited_api": "cp311"}
+
 ext_modules = [
     Extension(
         "cwcwidth._impl",
         extension_sources,
         define_macros=define_macros,
+        py_limited_api=use_limited_api,
     )
 ]
 
@@ -26,4 +36,5 @@ setup(
     package_data={
         "cwcwidth": ["_impl.pyi", "py.typed"],
     },
+    options=options,
 )