MySQL 8.0.32
Source Code Documentation
Example Setup for ctags

Put this configuration into your ~/.ctags file:

--c++-kinds=+p
--fields=+iaS
--extra=+q
--langdef=errmsg
--regex-errmsg=/^(ER_[A-Z0-9_]+)/\1/
--langmap=errmsg:(errmsg*.txt),c:+.ic,yacc:+.yy