https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111240
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |11.4.0
Status|UNCONFIRMED |NEW
Summary|Incorrect warning from |[12/13/14 Regression]
|-Wmaybe-uninitialized |Incorrect warning from
| |-Wmaybe-uninitialized
Last reconfirmed|2023-08-30 00:00:00 |2023-08-31
Target Milestone|--- |12.4
Known to fail| |12.1.0, 12.2.0, 13.2.0,
| |14.0
Keywords| |needs-reduction
Ever confirmed|0 |1
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.
rettype_58 = enforce_generic_type_consistency (&actual_arg_types,
&declared_arg_types, 0, _56, 0);
and we reach this on the args == 0 path where indeed actual_arg_types
is uninitialized and our heuristic says that a const qualified pointer
is an input and thus might be read. So you get a maybe-uninitialized
diagnostic at the call.
GCC doesn't know that the 'nargs' argument relates to the array and
that at most 'nargs' (zero here) arguments are inspected.
So I think it works as designed, we have some duplicate bugreports
complaining about this "heuristic".
We are exposing this to ourselves by optimizing the args == 0 case
(skipping the initialization loop and constant propagating the
nargs argument). Aka jump-threading.
