Check parameters of int.from_bytes

Author: isacben

locale/circuitpython.pot

@@ -2450,6 +2450,10 @@ msgstr ""
 msgid "byteorder is not a string"
 msgstr ""
 
+#: py/objint.c
+msgid "byteorder must be 'little' or 'big'"
+msgstr ""
+
 #: py/objarray.c
 msgid "bytes length not a multiple of item size"
 msgstr ""
@@ -2953,6 +2957,10 @@ msgstr ""
 msgid "frequency is read-only for this board"
 msgstr ""
 
+#: py/objint.c
+msgid "from_bytes() does not implement signed=True"
+msgstr ""
+
 #: py/objdeque.c
 msgid "full"
 msgstr ""

py/objint.c

@@ -480,19 +480,31 @@ MP_DEFINE_CONST_FUN_OBJ_1(int_bit_length_obj, int_bit_length);
 #endif
 
 // this is a classmethod
-STATIC mp_obj_t int_from_bytes(size_t n_args, const mp_obj_t *args) {
+STATIC mp_obj_t int_from_bytes(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     // TODO: Support signed param (assumes signed=False at the moment)
-    (void)n_args;
+
+    enum { ARG_signed };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_signed,    MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 3, pos_args + 3, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    if (args[ARG_signed].u_bool) {
+        mp_raise_msg(&mp_type_NotImplementedError, MP_ERROR_TEXT("from_bytes() does not implement signed=True"));
+    }
 
     // get the buffer info
     mp_buffer_info_t bufinfo;
-    mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_READ);
+    mp_get_buffer_raise(pos_args[1], &bufinfo, MP_BUFFER_READ);
 
     const byte *buf = (const byte *)bufinfo.buf;
     int delta = 1;
-    if (args[2] == MP_OBJ_NEW_QSTR(MP_QSTR_little)) {
+    if (pos_args[2] == MP_OBJ_NEW_QSTR(MP_QSTR_little)) {
         buf += bufinfo.len - 1;
         delta = -1;
+    } else if (pos_args[2] != MP_OBJ_NEW_QSTR(MP_QSTR_big)) {
+        mp_raise_ValueError(MP_ERROR_TEXT("byteorder must be 'little' or 'big'"));
     }
 
     mp_uint_t value = 0;
@@ -501,15 +513,15 @@ STATIC mp_obj_t int_from_bytes(size_t n_args, const mp_obj_t *args) {
         #if MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_NONE
         if (value > (MP_SMALL_INT_MAX >> 8)) {
             // Result will overflow a small-int so construct a big-int
-            return mp_obj_int_from_bytes_impl(args[2] != MP_OBJ_NEW_QSTR(MP_QSTR_little), bufinfo.len, bufinfo.buf);
+            return mp_obj_int_from_bytes_impl(pos_args[2] != MP_OBJ_NEW_QSTR(MP_QSTR_little), bufinfo.len, bufinfo.buf);
         }
         #endif
         value = (value << 8) | *buf;
     }
     return mp_obj_new_int_from_uint(value);
 }
 
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(int_from_bytes_fun_obj, 3, 4, int_from_bytes);
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(int_from_bytes_fun_obj, 3, int_from_bytes);
 STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(int_from_bytes_obj, MP_ROM_PTR(&int_from_bytes_fun_obj));
 
 STATIC mp_obj_t int_to_bytes(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {