Out of curiosity I built with -Wswitch-enum to see if it would be possible to just enable it. It looks like the main culprits are the node types and if those were switched to #defines it might be feasible to do so though it would still be a lot of hassle to add case labels all over the place.
But I had a second look to see if the output pointed out any actual bugs. I found one though it's pretty minor: lockfuncs.c:234:3: warning: enumeration value ‘LOCKTAG_SPECULATIVE_TOKEN’ not handled in switch [-Wswitch-enum] switch ((LockTagType) instance->locktag.locktag_type) ^~~~~~ It just causes speculative locks to be printed wrong in the pg_lock_status view. And speculative locks are only held transiently so unless you're do a bulk load using ON CONFLICT (and also cared about pg_lock_status, perhaps in some monitoring tool) you wouldn't even notice this: postgres***=# select * from pg_lock_status() where locktype = 'speculative token'; ┌───────────────────┬──────────┬──────────┬──────┬───────┬────────────┬───────────────┬─────────┬───────┬──────────┬────────────────────┬───────┬───────────────┬─────────┬──────────┐ │ locktype │ database │ relation │ page │ tuple │ virtualxid │ transactionid │ classid │ objid │ objsubid │ virtualtransaction │ pid │ mode │ granted │ fastpath │ ├───────────────────┼──────────┼──────────┼──────┼───────┼────────────┼───────────────┼─────────┼───────┼──────────┼────────────────────┼───────┼───────────────┼─────────┼──────────┤ │ speculative token │ 634 │ │ │ │ │ │ 1 │ 0 │ 0 │ 4/32 │ 18652 │ ExclusiveLock │ t │ f │ └───────────────────┴──────────┴──────────┴──────┴───────┴────────────┴───────────────┴─────────┴───────┴──────────┴────────────────────┴───────┴───────────────┴─────────┴──────────┘ The speculative lock is actually on a transaction ID and "speculative lock token" so the "database", "objid", and "objsubid" are bogus here.
