https://begriffs.com/posts/2021-11-28-practical-parsing.html bison location tracking manual entry https://www.gnu.org/software/bison/manual/html_node/Tracking-Locations.html#Tracking-Locations getting column and line number https://stackoverflow.com/questions/656703/how-does-flex-support-bison-location-exactly look into YYLLOC_DEFAULT from hello.tab.c, maybe it keeps track of location information?