Re: [Qemu-devel] [PATCH] block/vpc: fix uninitialised variable compiler warning

[Eric Blake <eblake@redhat.com>]

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On 07/21/2017 03:21 AM, Mark Cave-Ayland wrote:
> Since commit cfc87e00 "block/vpc.c: Handle write failures in
> get_image_offset()" older versions of gcc (in this case 4.7) incorrectly
> warn that "ret" can be used uninitialised in vpc_co_pwritev().
> 
> Setting ret to 0 at the start of vpc_co_pwritev() prevents the warning
> in gcc 4.7 and enables compilation with -Werror to succeed.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  block/vpc.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

> diff --git a/block/vpc.c b/block/vpc.c
> index 10e6519..574879b 100644
> --- a/block/vpc.c
> +++ b/block/vpc.c
> @@ -649,7 +649,7 @@ vpc_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
>      int64_t image_offset;
>      int64_t n_bytes;
>      int64_t bytes_done = 0;
> -    int ret;
> +    int ret = 0;
>      VHDFooter *footer =  (VHDFooter *) s->footer_buf;
>      QEMUIOVector local_qiov;
>  
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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