TST: Test building third party C extensions with Py_LIMITED_API

Fixes #13784.

2 files changed, 32 insertions, 2 deletions

diff --git a/numpy/core/tests/examples/example_limited_api.c b/numpy/core/tests/examples/example_limited_api.c
new file mode 100644
index 000000000..e811800b4
--- /dev/null
+++ b/numpy/core/tests/examples/example_limited_api.c
@@ -0,0 +1,22 @@
+/*
+ * Test that third-party extensions that use the Numpy C API can be built with
+ * the limited Python C API (see https://docs.python.org/3/c-api/stable.html).
+ */
+
+#define Py_LIMITED_API 0x03060000
+
+#include <Python.h>
+#include <numpy/arrayobject.h>
+#include <numpy/ufuncobject.h>
+
+static PyModuleDef moduledef = {
+    .m_base = PyModuleDef_HEAD_INIT,
+    .m_name = "example_limited_api"
+};
+
+PyMODINIT_FUNC PyInit_example_limited_api(void)
+{
+    import_array();
+    import_umath();
+    return PyModule_Create(&moduledef);
+}
diff --git a/numpy/core/tests/examples/setup.py b/numpy/core/tests/examples/setup.py
index 6e34aa778..6ec0b4197 100644
--- a/numpy/core/tests/examples/setup.py
+++ b/numpy/core/tests/examples/setup.py
@@ -9,16 +9,24 @@ from Cython.Build import cythonize
 from setuptools.extension import Extension
 import os
 
+include_dirs = [np.get_include()]
 macros = [("NPY_NO_DEPRECATED_API", 0)]
 
 checks = Extension(
     "checks",
     sources=[os.path.join('.', "checks.pyx")],
-    include_dirs=[np.get_include()],
+    include_dirs=include_dirs,
     define_macros=macros,
 )
 
-extensions = [checks]
+example_limited_api = Extension(
+    "example_limited_api",
+    sources=[os.path.join('.', "example_limited_api.c")],
+    include_dirs=include_dirs,
+    define_macros=macros,
+)
+
+extensions = [checks, example_limited_api]
 
 setup(
     ext_modules=cythonize(extensions)