codegen: Add a check for C structure fields

This check make sure that output fields for member with @end (arrays)
are declared as empty arrays in output C structure.
This avoids output fields to be declared as pointer or other
invalid types.
The check is a compile time check so no code in object file
is generated.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Uri Lublin <uril@redhat.com>

python_modules/demarshal.py

@@ -805,6 +805,9 @@ def write_array_parser(writer, member, nelements, array, dest, scope):
     if member:
         array_start = dest.get_ref(member.name)
         at_end = member.has_end_attr()
+        # the field is supposed to be a [0] array, check it
+        if at_end:
+            writer.statement('verify(sizeof(%s) == 0)' % array_start)
     else:
         array_start = "end"
         at_end = True