py: Implement integer overflow checking for * and << ops.

If operation will overflow, a multi-precision integer is created.

1 files changed, 3 insertions, 3 deletions

diff --git a/py/obj.h b/py/obj.h
index 4d93c7afad..d41db37c08 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -29,6 +29,8 @@ typedef struct _mp_obj_base_t mp_obj_base_t;
 //  - xxxx...xx00: a pointer to an mp_obj_base_t
 
 // In SMALL_INT, next-to-highest bits is used as sign, so both must match for value in range
+#define MP_SMALL_INT_MIN ((mp_small_int_t)(((machine_int_t)WORD_MSBIT_HIGH) >> 1))
+#define MP_SMALL_INT_MAX ((mp_small_int_t)(~(MP_SMALL_INT_MIN)))
 #define MP_OBJ_FITS_SMALL_INT(n) ((((n) ^ ((n) << 1)) & WORD_MSBIT_HIGH) == 0)
 #define MP_OBJ_IS_SMALL_INT(o) ((((mp_small_int_t)(o)) & 1) != 0)
 #define MP_OBJ_IS_QSTR(o) ((((mp_small_int_t)(o)) & 3) == 2)
@@ -218,9 +220,7 @@ mp_obj_t mp_obj_new_cell(mp_obj_t obj);
 mp_obj_t mp_obj_new_int(machine_int_t value);
 mp_obj_t mp_obj_new_int_from_uint(machine_uint_t value);
 mp_obj_t mp_obj_new_int_from_long_str(const char *s);
-#if MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_NONE
-mp_obj_t mp_obj_new_int_from_ll(long long val);
-#endif
+mp_obj_t mp_obj_new_int_from_ll(long long val); // this must return a multi-precision integer object (or raise an overflow exception)
 mp_obj_t mp_obj_new_str(const byte* data, uint len, bool make_qstr_if_not_already);
 mp_obj_t mp_obj_new_bytes(const byte* data, uint len);
 #if MICROPY_ENABLE_FLOAT