Re: pg_get_functiondef forgets about most GUC_LIST_INPUT GUCs

Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
> While reviewing another patch related to the use of pg_strcasecmp in the
> backend, I have noticed this bit in ruleutils.c:

> /*
> * Some GUC variable names are 'LIST' type and hence must not
> * be quoted.
> */
> if (pg_strcasecmp(configitem, "DateStyle") == 0
> || pg_strcasecmp(configitem, "search_path") == 0)
> appendStringInfoString(&buf, pos);
> else
> simple_quote_literal(&buf, pos);

> However this fails to consider all GUCs marked as GUC_LIST_INPUT, like
> the recent wal_consistency_checking.

Mmm, yeah, probably time to find a more maintainable solution to that.

> guc.c already holds a find_option()
> which can be used to retrieve the flags of a parameter. What about using
> that and filtering by GUC_LIST_INPUT? This requires exposing the
> function, and I am not sure what people think about that.

Don't like exposing find_option directly, but I think it would make
sense to provide an API along the lines of
int GetConfigOptionFlags(const char *name, bool missing_ok).

regards, tom lane