1 files changed, 26 insertions, 0 deletions
diff --git a/python/google/protobuf/pyext/message_module.cc b/python/google/protobuf/pyext/message_module.cc
index 7c4df47f..8c933866 100644
--- a/python/google/protobuf/pyext/message_module.cc
+++ b/python/google/protobuf/pyext/message_module.cc
@@ -31,9 +31,26 @@
 #include <Python.h>
 
 #include <google/protobuf/pyext/message.h>
+#include <google/protobuf/proto_api.h>
 
 #include <google/protobuf/message_lite.h>
 
+namespace {
+
+// C++ API.  Clients get at this via proto_api.h
+struct ApiImplementation : google::protobuf::python::PyProto_API {
+  const google::protobuf::Message*
+      GetMessagePointer(PyObject* msg) const override {
+    return google::protobuf::python::PyMessage_GetMessagePointer(msg);
+  }
+  google::protobuf::Message*
+      GetMutableMessagePointer(PyObject* msg) const override {
+    return google::protobuf::python::PyMessage_GetMutableMessagePointer(msg);
+  }
+};
+
+}  // namespace
+
 static PyObject* GetPythonProto3PreserveUnknownsDefault(
     PyObject* /*m*/, PyObject* /*args*/) {
   if (google::protobuf::internal::GetProto3PreserveUnknownsDefault()) {
@@ -113,6 +130,15 @@ extern "C" {
       Py_DECREF(m);
       return INITFUNC_ERRORVAL;
     }
+    
+    // Adds the C++ API
+    if (PyObject* api =
+            PyCapsule_New(new ApiImplementation(),
+                          google::protobuf::python::PyProtoAPICapsuleName(), NULL)) {
+      PyModule_AddObject(m, "proto_API", api);
+    } else {
+      return INITFUNC_ERRORVAL;
+    }
 
 #if PY_MAJOR_VERSION >= 3
     return m;