Re: [PATCH for-8.0 1/3] async: Suppress GCC13 false positive in aio_bh_poll()

[Paolo Bonzini <pbonzini@redhat.com>]

On 3/21/23 09:33, Cédric Le Goater wrote:
> From: Cédric Le Goater<clg@redhat.com>
> 
> GCC13 reports an error :
> 
> ../util/async.c: In function ‘aio_bh_poll’:
> include/qemu/queue.h:303:22: error: storing the address of local variable ‘slice’ in ‘*ctx.bh_slice_list.sqh_last’ [-Werror=dangling-pointer=]
>    303 |     (head)->sqh_last = &(elm)->field.sqe_next;                          \
>        |     ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
> ../util/async.c:169:5: note: in expansion of macro ‘QSIMPLEQ_INSERT_TAIL’
>    169 |     QSIMPLEQ_INSERT_TAIL(&ctx->bh_slice_list, &slice, next);
>        |     ^~~~~~~~~~~~~~~~~~~~
> ../util/async.c:161:17: note: ‘slice’ declared here
>    161 |     BHListSlice slice;
>        |                 ^~~~~
> ../util/async.c:161:17: note: ‘ctx’ declared here
> 
> But the local variable 'slice' is removed from the global context list
> in following loop of the same routine. Add an intermediate helper to
> silent GCC. No functional change.

Before doing this, I would like to see a case where this bug was _not_ 
caught by either Coverity (which is currently offline but I'm fixing it 
right now) or just cursory review.

I'd rather remove the warning.

Paolo