py: Enable struct/binary-helper to parse q and Q sized ints.

Addresses issue #848.

1 files changed, 20 insertions, 7 deletions

diff --git a/py/binary.c b/py/binary.c
index 919ba8784..835ba8aa2 100644
--- a/py/binary.c
+++ b/py/binary.c
@@ -34,6 +34,7 @@
 #include "misc.h"
 #include "qstr.h"
 #include "obj.h"
+#include "smallint.h"
 #include "binary.h"
 
 // Helpers to work with binary-encoded data
@@ -136,7 +137,10 @@ mp_obj_t mp_binary_get_val_array(char typecode, void *p, int index) {
     return MP_OBJ_NEW_SMALL_INT(val);
 }
 
-mp_int_t mp_binary_get_int(mp_uint_t size, bool is_signed, bool big_endian, byte *p) {
+// The long long type is guaranteed to hold at least 64 bits, and size is at
+// most 8 (for q and Q), so we will always be able to parse the given data
+// and fit it into a long long.
+long long mp_binary_get_int(mp_uint_t size, bool is_signed, bool big_endian, byte *p) {
     int delta;
     if (!big_endian) {
         delta = -1;
@@ -145,7 +149,7 @@ mp_int_t mp_binary_get_int(mp_uint_t size, bool is_signed, bool big_endian, byte
         delta = 1;
     }
 
-    mp_int_t val = 0;
+    long long val = 0;
     if (is_signed && *p & 0x80) {
         val = -1;
     }
@@ -175,16 +179,25 @@ mp_obj_t mp_binary_get_val(char struct_type, char val_type, byte **ptr) {
     }
     *ptr = p + size;
 
-    mp_int_t val = mp_binary_get_int(size, is_signed(val_type), (struct_type == '>'), p);
+    long long val = mp_binary_get_int(size, is_signed(val_type), (struct_type == '>'), p);
 
     if (val_type == 'O') {
-        return (mp_obj_t)val;
+        return (mp_obj_t)(mp_uint_t)val;
     } else if (val_type == 'S') {
-        return mp_obj_new_str((char*)val, strlen((char*)val), false);
+        const char *s_val = (const char*)(mp_uint_t)val;
+        return mp_obj_new_str(s_val, strlen(s_val), false);
     } else if (is_signed(val_type)) {
-        return mp_obj_new_int(val);
+        if ((long long)MP_SMALL_INT_MIN <= val && val <= (long long)MP_SMALL_INT_MAX) {
+            return mp_obj_new_int((mp_int_t)val);
+        } else {
+            return mp_obj_new_int_from_ll(val);
+        }
     } else {
-        return mp_obj_new_int_from_uint(val);
+        if ((unsigned long long)val <= (unsigned long long)MP_SMALL_INT_MAX) {
+            return mp_obj_new_int_from_uint((mp_uint_t)val);
+        } else {
+            return mp_obj_new_int_from_ull(val);
+        }
     }
 }