py: Implement sys.maxsize, standard way to check platform "bitness".
Implementing it as a static constant is a bit peculiar and require cooperation
from long int implementation.
diff --git a/py/modsys.c b/py/modsys.c
index 1e7f7ef..d215846 100644
--- a/py/modsys.c
+++ b/py/modsys.c
@@ -24,6 +24,8 @@
* THE SOFTWARE.
*/
+#include <stdint.h>
+#include <limits.h>
#include "mpconfig.h"
#include "misc.h"
#include "qstr.h"
@@ -33,6 +35,8 @@
#include "objlist.h"
#include "objtuple.h"
#include "objstr.h"
+#include "mpz.h"
+#include "objint.h"
#if MICROPY_PY_SYS
@@ -44,6 +48,8 @@
extern struct _dummy_t mp_sys_stdout_obj;
extern struct _dummy_t mp_sys_stderr_obj;
+extern mp_obj_int_t mp_maxsize_obj;
+
mp_obj_list_t mp_sys_path_obj;
mp_obj_list_t mp_sys_argv_obj;
#define I(n) MP_OBJ_NEW_SMALL_INT(n)
@@ -70,6 +76,19 @@
#else
{ MP_OBJ_NEW_QSTR(MP_QSTR_byteorder), MP_OBJ_NEW_QSTR(MP_QSTR_big) },
#endif
+#if MICROPY_PY_SYS_MAXSIZE
+ #if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_NONE
+ // INT_MAX is not representable as small int, as we know that small int
+ // takes one bit for tag. So, we have little choice but to provide this
+ // value. Apps also should be careful to not try to compare sys.maxsize
+ // with some number (which may not fit in available int size), but instead
+ // count number of significant bits in sys.maxsize.
+ { MP_OBJ_NEW_QSTR(MP_QSTR_maxsize), MP_OBJ_NEW_SMALL_INT(INT_MAX >> 1) },
+ #else
+ { MP_OBJ_NEW_QSTR(MP_QSTR_maxsize), (mp_obj_t)&mp_maxsize_obj },
+ #endif
+#endif
+
#if MICROPY_PY_SYS_EXIT
{ MP_OBJ_NEW_QSTR(MP_QSTR_exit), (mp_obj_t)&mp_sys_exit_obj },