Re: PG19beta1: GCC 16.1.1 warning: ‘actual_arg_types’ may be used uninitialized in clauses.c

On 2026-Jun-04, Nathan Bossart wrote:

> On Thu, Jun 04, 2026 at 02:42:18PM +0000, Hans Buschmann wrote:
> > 839/2360] Compiling C object src/backend/postgres_lib.a.p/optimizer_util_clauses.c.o
> > ../src/backend/optimizer/util/clauses.c: In function ‘recheck_cast_function_args.isra’:
> > ../src/backend/optimizer/util/clauses.c:5152:19: warning: ‘actual_arg_types’ may be used uninitialized [-Wmaybe-uninitialized]
> > 5152 | rettype = enforce_generic_type_consistency(actual_arg_types,
>
> This code is ~18 years old, so I'm dubious there's a real problem here.
> Does something like this suppress the warning?
>
> Oid actual_arg_types[FUNC_MAX_ARGS] = {InvalidOid};

I agree that it doesn't look like there's a real problem, and that
something like what you suggest should silence this warning. I mildly
prefer to do " = {0}" though, the rules for C incomplete initializers
being so weird. But I wouldn't oppose this patch as posted.

BTW we seem to do pretty much the same thing in ParseFuncOrColumn(),
right?

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"People get annoyed when you try to debug them." (Larry Wall)