py/binary: mp_binary_get_size: Raise error on unsupported typecodes.

Previouly, we had errors checked in callers, which led to duplicate code
or missing checks in some places.

py/binary.c

@@ -33,6 +33,7 @@
 #include "py/binary.h"
 #include "py/smallint.h"
 #include "py/objint.h"
+#include "py/runtime.h"
 
 // Helpers to work with binary-encoded data
 
@@ -100,6 +101,11 @@ size_t mp_binary_get_size(char struct_type, char val_type, mp_uint_t *palign) {
             }
         }
     }
+
+    if (size == 0) {
+        mp_raise_ValueError("bad typecode");
+    }
+
     if (palign != NULL) {
         *palign = align;
     }

py/modstruct.c

@@ -113,9 +113,6 @@ STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
         } else {
             mp_uint_t align;
             size_t sz = mp_binary_get_size(fmt_type, *fmt, &align);
-            if (sz == 0) {
-                mp_raise_ValueError("unsupported format");
-            }
             while (cnt--) {
                 // Apply alignment
                 size = (size + align - 1) & ~(align - 1);

py/objarray.c

@@ -94,9 +94,6 @@ STATIC void array_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t
 #if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
 STATIC mp_obj_array_t *array_new(char typecode, mp_uint_t n) {
     int typecode_size = mp_binary_get_size('@', typecode, NULL);
-    if (typecode_size == 0) {
-        mp_raise_msg(&mp_type_ValueError, "bad typecode");
-    }
     mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
     #if MICROPY_PY_BUILTINS_BYTEARRAY && MICROPY_PY_ARRAY
     o->base.type = (typecode == BYTEARRAY_TYPECODE) ? &mp_type_bytearray : &mp_type_array;

tests/basics/struct2.py

@@ -26,7 +26,17 @@ print(struct.calcsize('0s1s0H2H'))
 print(struct.unpack('<0s1s0H2H', b'01234'))
 print(struct.pack('<0s1s0H2H', b'abc', b'abc', 258, 515))
 
-# check that zero of an unknown type raises an exception
+# check that unknown types raise an exception
+try:
+    struct.unpack('z', b'1')
+except:
+    print('Exception')
+
+try:
+    struct.pack('z', (b'1',))
+except:
+    print('Exception')
+
 try:
     struct.calcsize('0z')
 except: