Debian 12 gcc warning

On Debian 12, gcc version 12.2.0 (Debian 12.2.0-14) generates a warning
on PG 13 to current, but only with -O1 optimization level, and not at
-O0/-O2/-O3:

clauses.c: In function ‘recheck_cast_function_args’:
clauses.c:4293:19: warning: ‘actual_arg_types’ may be used uninitialized [-Wmaybe-uninitialized]
4293 | rettype = enforce_generic_type_consistency(actual_arg_types,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4294 | declared_arg_types,
| ~~~~~~~~~~~~~~~~~~~
4295 | nargs,
| ~~~~~~
4296 | funcform->prorettype,
| ~~~~~~~~~~~~~~~~~~~~~
4297 | false);
| ~~~~~~
In file included from clauses.c:45:
../../../../src/include/parser/parse_coerce.h:82:17: note: by argument 1 of type ‘const Oid *’ {aka ‘const unsigned int *’} to ‘enforce_generic_type_consistency’ declared here
82 | extern Oid enforce_generic_type_consistency(const Oid *actual_arg_types,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
clauses.c:4279:33: note: ‘actual_arg_types’ declared here
4279 | Oid actual_arg_types[FUNC_MAX_ARGS];
| ^~~~~~~~~~~~~~~~

The code is:

static void
recheck_cast_function_args(List *args, Oid result_type,
Oid *proargtypes, int pronargs,
HeapTuple func_tuple)
{
Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
int nargs;
Oid actual_arg_types[FUNC_MAX_ARGS];
Oid declared_arg_types[FUNC_MAX_ARGS];
Oid rettype;
ListCell *lc;

if (list_length(args) > FUNC_MAX_ARGS)
elog(ERROR, "too many function arguments");
nargs = 0;
foreach(lc, args)
{
actual_arg_types[nargs++] = exprType((Node *) lfirst(lc));
}
Assert(nargs == pronargs);
memcpy(declared_arg_types, proargtypes, pronargs * sizeof(Oid));
--> rettype = enforce_generic_type_consistency(actual_arg_types,
declared_arg_types,
nargs,
funcform->prorettype,
false);
/* let's just check we got the same answer as the parser did ... */

I don't see a clean way of avoiding the warning except by initializing
the array, which seems wasteful.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Only you can decide what is important to you.