Re: [paulmckrcu:dev.2026.07.13b 75/86] warning: constant `WARN_ON_FLAGS` is never used

On Sun, Jul 19, 2026 at 12:38:20AM +0800, kernel test robot wrote:
> tree:   https://github.com/paulmckrcu/linux dev.2026.07.13b
> head:   04b88652be5bc3b092a63198d1b2bebaf46b9e72
> commit: f41634950050921c691e1fabdafc0304c2aedfdf [75/86] rust: sync: add SRCU abstraction
> config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20260719/[email protected]/config)
> compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
> rustc: rustc 1.96.0 (ac68faa20 2026-05-25)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260719/[email protected]/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <[email protected]>
> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> 
> All warnings (new ones prefixed by >>):
> 
> >> warning: constant `WARN_ON_FLAGS` is never used
>    --> rust/kernel/bug.rs:126:19
>    |
>    126 |               const WARN_ON_FLAGS: u32 = $crate::bug::bugflag_taint($crate::bindings::TAINT_WARN);
>    |                     ^^^^^^^^^^^^^

[Cc Miguel and Tomo]

Is this one supposed to fix the issue?

	https://lore.kernel.org/rust-for-linux/[email protected]/

Regards,
Boqun

>    |
>    ::: rust/kernel/sync/srcu.rs:106:12
>    |
>    106 |           if crate::warn_on!(
>    |  ____________-
>    107 | |             // SAFETY: By the type invariants, `self` contains a valid and pinned `struct srcu_struct`
>    108 | |             // and `srcu_readers_active()` only checks the active reader count.
>    109 | |             unsafe { bindings::srcu_readers_active(ptr) }
>    110 | |         ) {
>    | |_________- in this macro invocation
>    |
>    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
>    = note: this warning originates in the macro `crate::warn_on` (in Nightly builds, run with -Z macro-backtrace for more info)
> 
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki