Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
> as shown here:
> 
> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>   604 |             *buf = src;
>       |             ~~~~~^~~~~
> cc1: all warnings being treated as errors
> 
> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>

Yes, I think I had a discussion with someone about this recently but
can't find it; the compiler is technically correct, but the only time
it's unitialised is the case where it's result doesn't matter.

Still, to shut the compiler up:


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
> 
>  migration/qemu-file.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index be21518c57..d6e03dbc0e 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
>  {
>      if (size < IO_BUF_SIZE) {
>          size_t res;
> -        uint8_t *src;
> +        uint8_t *src = NULL;
>  
>          res = qemu_peek_buffer(f, &src, size, 0);
>  
> -- 
> 2.28.0
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK