Re: hba.c:3160:18: warning: comparison of unsigned enum expression

On Wed, Apr 7, 2021 at 1:24 PM Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>
> On Wed, Apr 7, 2021 at 1:01 PM Erik Rijkers <er(at)xs4all(dot)nl> wrote:
> >
> > Recently (last day or so), I get this warning from gcc 10.2:
> >
> > -----
> > hba.c:3160:18: warning: comparison of unsigned enum expression < 0 is always false [-Wtautological-compare]
> > if (auth_method < 0 || USER_AUTH_LAST < auth_method)
> > ~~~~~~~~~~~ ^ ~
> > 1 warning generated.
> > -----
>
> This one is from 9afffcb833d3c5e59a328a2af674fac7e7334fc1 (adding
> Jacob and Michael to cc)
>
> And it makes sense to give warning on that. AuthMethod is an enum. It
> can by definition not have a value that's not in the enum. That check
> simply seems wrong/unnecessary.
>
> The only other use fo USER_AUTH_LAST is in fill_hba_line() which also
> gets the name of the auth. That one uses :
> StaticAssertStmt(lengthof(UserAuthName) == USER_AUTH_LAST + 1,
> "UserAuthName[] must match the UserAuth enum");
>
> Which seems like a more reasonable check.
>
> But that also highlights -- shouldn't that function then also be made
> to use hba_authname(), and the assert moved into the function? That
> seems like the cleanest way?

So to be clear, this is what I'm suggesting.

--
Magnus Hagander
Me: https://www.hagander.net/
Work: https://www.redpill-linpro.com/