py: More robust int conversion and overflow checking.
diff --git a/py/mpz.c b/py/mpz.c
index 79d200d..4a8941e 100644
--- a/py/mpz.c
+++ b/py/mpz.c
@@ -1139,6 +1139,7 @@
}
#endif
+// TODO check that this correctly handles overflow in all cases
machine_int_t mpz_as_int(const mpz_t *i) {
machine_int_t val = 0;
mpz_dig_t *d = i->dig + i->len;
@@ -1147,11 +1148,13 @@
machine_int_t oldval = val;
val = (val << DIG_SIZE) | *d;
if (val < oldval) {
- // TODO need better handling of conversion overflow
+ // overflow, return +/- "infinity"
if (i->neg == 0) {
- return 0x7fffffff;
+ // +infinity
+ return ~WORD_MSBIT_HIGH;
} else {
- return 0x80000000;
+ // -infinity
+ return WORD_MSBIT_HIGH;
}
}
}
@@ -1163,6 +1166,28 @@
return val;
}
+// TODO check that this correctly handles overflow in all cases
+bool mpz_as_int_checked(const mpz_t *i, machine_int_t *value) {
+ machine_int_t val = 0;
+ mpz_dig_t *d = i->dig + i->len;
+
+ while (--d >= i->dig) {
+ machine_int_t oldval = val;
+ val = (val << DIG_SIZE) | *d;
+ if (val < oldval) {
+ // overflow
+ return false;
+ }
+ }
+
+ if (i->neg != 0) {
+ val = -val;
+ }
+
+ *value = val;
+ return true;
+}
+
#if MICROPY_ENABLE_FLOAT
mp_float_t mpz_as_float(const mpz_t *i) {
mp_float_t val = 0;
diff --git a/py/mpz.h b/py/mpz.h
index 7778893..cbe60eb 100644
--- a/py/mpz.h
+++ b/py/mpz.h
@@ -71,6 +71,7 @@
mpz_t *mpz_mod(const mpz_t *lhs, const mpz_t *rhs);
machine_int_t mpz_as_int(const mpz_t *z);
+bool mpz_as_int_checked(const mpz_t *z, machine_int_t *value);
#if MICROPY_ENABLE_FLOAT
mp_float_t mpz_as_float(const mpz_t *z);
#endif
diff --git a/py/obj.c b/py/obj.c
index 95052d1..bf3e1d5 100644
--- a/py/obj.c
+++ b/py/obj.c
@@ -203,6 +203,24 @@
}
}
+// returns false if arg is not of integral type
+// returns true and sets *value if it is of integral type
+// can throw OverflowError if arg is of integral type, but doesn't fit in a machine_int_t
+bool mp_obj_get_int_maybe(mp_obj_t arg, machine_int_t *value) {
+ if (arg == mp_const_false) {
+ *value = 0;
+ } else if (arg == mp_const_true) {
+ *value = 1;
+ } else if (MP_OBJ_IS_SMALL_INT(arg)) {
+ *value = MP_OBJ_SMALL_INT_VALUE(arg);
+ } else if (MP_OBJ_IS_TYPE(arg, &mp_type_int)) {
+ *value = mp_obj_int_get_checked(arg);
+ } else {
+ return false;
+ }
+ return true;
+}
+
#if MICROPY_ENABLE_FLOAT
mp_float_t mp_obj_get_float(mp_obj_t arg) {
if (arg == mp_const_false) {
diff --git a/py/obj.h b/py/obj.h
index 952187e..f5ce873 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -359,6 +359,7 @@
bool mp_obj_less(mp_obj_t o1, mp_obj_t o2);
machine_int_t mp_obj_get_int(mp_obj_t arg);
+bool mp_obj_get_int_maybe(mp_obj_t arg, machine_int_t *value);
#if MICROPY_ENABLE_FLOAT
mp_float_t mp_obj_get_float(mp_obj_t self_in);
void mp_obj_get_complex(mp_obj_t self_in, mp_float_t *real, mp_float_t *imag);
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
index 27f77d1..25a069c 100644
--- a/py/objint_mpz.c
+++ b/py/objint_mpz.c
@@ -243,8 +243,18 @@
}
machine_int_t mp_obj_int_get_checked(mp_obj_t self_in) {
- // TODO: Check overflow
- return mp_obj_int_get(self_in);
+ if (MP_OBJ_IS_SMALL_INT(self_in)) {
+ return MP_OBJ_SMALL_INT_VALUE(self_in);
+ } else {
+ mp_obj_int_t *self = self_in;
+ machine_int_t value;
+ if (mpz_as_int_checked(&self->mpz, &value)) {
+ return value;
+ } else {
+ // overflow
+ nlr_jump(mp_obj_new_exception_msg(&mp_type_OverflowError, "overflow converting long int to machine word"));
+ }
+ }
}
#if MICROPY_ENABLE_FLOAT
diff --git a/py/objlist.c b/py/objlist.c
index 244d4a5..2a5f2c8 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -122,12 +122,11 @@
list_extend(lhs, rhs);
return o;
}
- case MP_BINARY_OP_MULTIPLY:
- {
- if (!MP_OBJ_IS_SMALL_INT(rhs)) {
+ case MP_BINARY_OP_MULTIPLY: {
+ machine_int_t n;
+ if (!mp_obj_get_int_maybe(rhs, &n)) {
return NULL;
}
- int n = MP_OBJ_SMALL_INT_VALUE(rhs);
mp_obj_list_t *s = list_new(o->len * n);
mp_seq_multiply(o->items, sizeof(*o->items), o->len, n, s->items);
return s;