From 8491eb190f2ea27f113c0cc7c0e619807a84f7ed Mon Sep 17 00:00:00 2001 From: David Lechner Date: Thu, 12 Jan 2023 19:51:45 -0600 Subject: [PATCH] py/objslice: Ensure slice is not hashable. As per https://bugs.python.org/issue408326, the slice object should not be hashable. Since MicroPython has an implicit fallback when the unary_op slot is empty, we need to fill this slot. Signed-off-by: David Lechner --- py/objslice.c | 7 +++++++ tests/basics/slice_op.py | 15 +++++++++++++++ 2 files changed, 22 insertions(+) create mode 100644 tests/basics/slice_op.py diff --git a/py/objslice.c b/py/objslice.c index 01d4da0dbd..75fa3bc3f5 100644 --- a/py/objslice.c +++ b/py/objslice.c @@ -46,6 +46,12 @@ STATIC void slice_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t mp_print_str(print, ")"); } +STATIC mp_obj_t slice_unary_op(mp_unary_op_t op, mp_obj_t o_in) { + // Needed to explicitly opt out of default __hash__. + // REVISIT: CPython implements comparison operators for slice. + return MP_OBJ_NULL; +} + #if MICROPY_PY_BUILTINS_SLICE_INDICES STATIC mp_obj_t slice_indices(mp_obj_t self_in, mp_obj_t length_obj) { mp_int_t length = mp_obj_int_get_checked(length_obj); @@ -104,6 +110,7 @@ MP_DEFINE_CONST_OBJ_TYPE( mp_type_slice, MP_QSTR_slice, MP_TYPE_FLAG_NONE, + unary_op, slice_unary_op, SLICE_TYPE_ATTR_OR_LOCALS_DICT print, slice_print ); diff --git a/tests/basics/slice_op.py b/tests/basics/slice_op.py new file mode 100644 index 0000000000..f1e83c5e27 --- /dev/null +++ b/tests/basics/slice_op.py @@ -0,0 +1,15 @@ + +try: + t = [][:] +except: + print("SKIP") + raise SystemExit + + +# REVISIT: slice comparison operators are not implemented in MicroPython + +# test that slice is not hashable, i.e. it can't be used to copy a dict +try: + {}[:] = {} +except TypeError: + print('TypeError')