findMissingIncludeGuards.py

#!/usr/bin/env python3

import os

error = False
for root, dirnames, filenames in os.walk(".."):
   for filename in filenames:
      if filename.endswith((".h")) and not filename.endswith((".impl.h")):
         if not "extern" in root:
            file = os.path.join(root, filename)
            if not "#pragma once" in open(file).read():
               print(file)
               error = True

if error:
   exit(-1)