py: Add support for properties on native objects when they are in the…

… locals dict.
adafruit · tannewt · Nov 21, 2016 · Nov 5, 2016 · Nov 21, 2016 · Nov 3, 2016
commit f03a9ac505c563d9c7d06f198d1af2674328bfe3
diff --git a/py/runtime.c b/py/runtime.c
@@ -34,6 +34,7 @@
 #include "py/compile.h"
 #include "py/objstr.h"
 #include "py/objtuple.h"
+#include "py/objtype.h"
 #include "py/objlist.h"
 #include "py/objmodule.h"
 #include "py/objgenerator.h"
@@ -102,7 +103,7 @@ void mp_deinit(void) {
     //mp_obj_dict_free(&dict_main);
     mp_module_deinit();
 
-    // call port specific deinitialization if any 
+    // call port specific deinitialization if any
 #ifdef MICROPY_PORT_INIT_FUNC
     MICROPY_PORT_DEINIT_FUNC;
 #endif
@@ -989,6 +990,22 @@ void mp_convert_member_lookup(mp_obj_t self, const mp_obj_type_t *type, mp_obj_t
             dest[0] = member;
             dest[1] = self;
         }
+    #if MICROPY_PY_BUILTINS_PROPERTY
+    } else if (MP_OBJ_IS_TYPE(member, &mp_type_property) && mp_obj_is_native_type(type)) {
+        // object member is a property; delegate the load to the property
+        // Note: This is an optimisation for code size and execution time.
+        // The proper way to do it is have the functionality just below
+        // in a __get__ method of the property object, and then it would
+        // be called by the descriptor code down below.  But that way
+        // requires overhead for the nested mp_call's and overhead for
+        // the code.
+        const mp_obj_t *proxy = mp_obj_property_get(member);
+        if (proxy[0] == mp_const_none) {
+            mp_raise_msg(&mp_type_AttributeError, "unreadable attribute");
+        } else {
+            dest[0] = mp_call_function_n_kw(proxy[0], 1, 0, &self);
+        }
+    #endif
     } else {
         // class member is a value, so just return that value
         dest[0] = member;
@@ -1068,6 +1085,35 @@ void mp_store_attr(mp_obj_t base, qstr attr, mp_obj_t value) {
             // success
             return;
         }
+    #if MICROPY_PY_BUILTINS_PROPERTY
+    } else if (type->locals_dict != NULL) {
+        // generic method lookup
+        // this is a lookup in the object (ie not class or type)
+        assert(type->locals_dict->base.type == &mp_type_dict); // Micro Python restriction, for now
+        mp_map_t *locals_map = &type->locals_dict->map;
+        mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP);
+        if (elem != NULL && MP_OBJ_IS_TYPE(elem->value, &mp_type_property)) {
+            // attribute exists and is a property; delegate the store/delete
+            // Note: This is an optimisation for code size and execution time.
+            // The proper way to do it is have the functionality just below in
+            // a __set__/__delete__ method of the property object, and then it
+            // would be called by the descriptor code down below.  But that way
+            // requires overhead for the nested mp_call's and overhead for
+            // the code.
+            const mp_obj_t *proxy = mp_obj_property_get(elem->value);
+            mp_obj_t dest[2] = {base, value};
+            if (value == MP_OBJ_NULL) {
+                // delete attribute
+                if (proxy[2] != mp_const_none) {
+                    mp_call_function_n_kw(proxy[2], 1, 0, dest);
+                    return;
+                }
+            } else if (proxy[1] != mp_const_none) {
+                mp_call_function_n_kw(proxy[1], 2, 0, dest);
+                return;
+            }
+        }
+    #endif
     }
     if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE) {
         mp_raise_msg(&mp_type_AttributeError, "no such attribute");