Verify if a list of CONFIG_BLABLABLA is defined in the Kconfig. Just put the BLABLABLA in the configs_not_in_kconfig.txt each one in a line and then execute:
$ for i in $(cat listing_all_configs.txt); do find . -name Kconfig | xargs egrep -e "config\s$i" ; done
Listing all CONFIG_ that doesn’t exist in the Kconfig:
$ for i in $(cat listing_all_configs.txt); do find . -name Kconfig | xargs egrep -e "config\s$i" 2>&1 > /dev/null ; if [ $? -eq 0 ]; then echo "" ; else echo $i ; fi ; done > configs_not_in_kconfig.txt