1 files changed, 53 insertions, 0 deletions
diff --git a/circuitpython/py/proto.c b/circuitpython/py/proto.c
new file mode 100644
index 0000000..9f110b9
--- /dev/null
+++ b/circuitpython/py/proto.c
@@ -0,0 +1,53 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/obj.h"
+#include "py/proto.h"
+#include "py/runtime.h"
+
+#ifndef MICROPY_UNSAFE_PROTO
+const void *mp_proto_get(uint16_t name, mp_const_obj_t obj) {
+    const mp_obj_type_t *type = mp_obj_get_type(obj);
+    const void *protocol = mp_type_get_protocol_slot(type);
+    if (!protocol) {
+        return NULL;
+    }
+    uint16_t proto_name = *(const uint16_t *)protocol;
+    if (proto_name == name) {
+        return protocol;
+    }
+    return NULL;
+}
+#endif
+
+const void *mp_proto_get_or_throw(uint16_t name, mp_const_obj_t obj) {
+    const void *proto = mp_proto_get(name, obj);
+    if (proto) {
+        return proto;
+    }
+    mp_raise_TypeError_varg(MP_ERROR_TEXT("'%q' object does not support '%q'"),
+        mp_obj_get_type_qstr(obj), name);
+}