Drop using `setup_requires`. (#98)

* Drop using ``setup_requires`` due to constant problems on GHA.

* Add preliminary support for Python 3.12a7

1 files changed, 53 insertions, 0 deletions

diff --git a/include/zope.proxy/zope/proxy/proxy.h b/include/zope.proxy/zope/proxy/proxy.h
new file mode 100644
index 0000000..10e5b5b
--- /dev/null
+++ b/include/zope.proxy/zope/proxy/proxy.h
@@ -0,0 +1,53 @@
+#ifndef _proxy_H_
+#define _proxy_H_ 1
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *proxy_object;
+} ProxyObject;
+
+#define Proxy_GET_OBJECT(ob)   (((ProxyObject *)(ob))->proxy_object)
+
+typedef struct {
+    PyTypeObject *proxytype;
+    int (*check)(PyObject *obj);
+    PyObject *(*create)(PyObject *obj);
+    PyObject *(*getobject)(PyObject *proxy);
+} ProxyInterface;
+
+#ifndef PROXY_MODULE
+
+/* These are only defined in the public interface, and are not
+ * available within the module implementation.  There we use the
+ * classic Python/C API only.
+ */
+
+static ProxyInterface *_proxy_api = NULL;
+
+static int
+Proxy_Import(void)
+{
+    if (_proxy_api == NULL) {
+        PyObject *m = PyImport_ImportModule("zope.proxy");
+        if (m != NULL) {
+            PyObject *tmp = PyObject_GetAttrString(m, "_CAPI");
+            if (tmp != NULL) {
+                if (PyCapsule_CheckExact(tmp))
+                    _proxy_api = (ProxyInterface *)
+                        PyCapsule_GetPointer(tmp, NULL);
+                Py_DECREF(tmp);
+            }
+        }
+    }
+    return (_proxy_api == NULL) ? -1 : 0;
+}
+
+#define ProxyType               (*_proxy_api->proxytype)
+#define Proxy_Check(obj)        (_proxy_api->check((obj)))
+#define Proxy_CheckExact(obj)   ((obj)->ob_type == ProxyType)
+#define Proxy_New(obj)          (_proxy_api->create((obj)))
+#define Proxy_GetObject(proxy)  (_proxy_api->getobject((proxy)))
+
+#endif /* PROXY_MODULE */
+
+#endif /* _proxy_H_ */