py/objboundmeth: Add option to use mp_is_equal instead of == comparison.

This option is needed for ports such as webassembly where objects are
proxied and can be identical without being the same C pointer.

Signed-off-by: Damien George <damien@micropython.org>

Author: dpgeorge

py/mpconfig.h

@@ -1129,6 +1129,14 @@ typedef time_t mp_timestamp_t;
 #define MICROPY_PY_FUNCTION_ATTRS_CODE (MICROPY_CONFIG_ROM_LEVEL_AT_LEAST_FULL_FEATURES)
 #endif
 
+// Whether bound_method can just use == (feature disabled), or requires a call to
+// mp_obj_equal (feature enabled), to test equality of the self and meth entities.
+// This is only needed if objects and functions can be identical without being the
+// same thing, eg when using an object proxy.
+#ifndef MICROPY_PY_BOUND_METHOD_FULL_EQUALITY_CHECK
+#define MICROPY_PY_BOUND_METHOD_FULL_EQUALITY_CHECK (0)
+#endif
+
 // Whether to support the descriptors __get__, __set__, __delete__, __set_name__
 // This costs some code size and makes load/store/delete of instance
 // attributes slower for the classes that use this feature

py/objboundmeth.c

@@ -102,7 +102,11 @@ static mp_obj_t bound_meth_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_
     }
     mp_obj_bound_meth_t *lhs = MP_OBJ_TO_PTR(lhs_in);
     mp_obj_bound_meth_t *rhs = MP_OBJ_TO_PTR(rhs_in);
+    #if MICROPY_PY_BOUND_METHOD_FULL_EQUALITY_CHECK
+    return mp_obj_new_bool(mp_obj_equal(lhs->self, rhs->self) && mp_obj_equal(lhs->meth, rhs->meth));
+    #else
     return mp_obj_new_bool(lhs->self == rhs->self && lhs->meth == rhs->meth);
+    #endif
 }
 
 #if MICROPY_PY_FUNCTION_ATTRS