[Spice-devel] [PATCH spice-protocol 1/2 v2] qxl_dev: Fix alignment for QXLReleaseInfo

[Snir Sheriber]

Hi,


IIRC this was related to some compiler warning, no?
If it is I'd mentioning it , otherwise, ack.

Snir.


On 7/4/19 4:56 PM, Frediano Ziglio wrote:
> Do not declare the structure as aligned.
> The start/end-packed.h headers affects structures without
> specification only using MingW or Microsoft compilers. For other
> platform SPICE_ATTR_PACKED macro should be used.  This way the
> definition are the same for all compiler.
> This structure is used in a lot of QXL structures which are not
> aligned causing to have an aligned structure to be potentially
> unaligned.
> As this structure has no holes this change does not make any size
> change using any compiler.
> The change will only change the alignment from 4/8 to 1.
> This could affect structures containing this union however beside
> packed structure in qxl_dev.h (which are not affected) there are no
> other usages affecting ABI by spice-gtk, Qemu or spice-server.
>
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
> Changes since v1:
> - update commit message
> ---
>   spice/qxl_dev.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/spice/qxl_dev.h b/spice/qxl_dev.h
> index a9cc4f4..659f930 100644
> --- a/spice/qxl_dev.h
> +++ b/spice/qxl_dev.h
> @@ -275,7 +275,7 @@ typedef struct SPICE_ATTR_ALIGNED(4) SPICE_ATTR_PACKED QXLRam {
>   
>   } QXLRam;
>   
> -typedef union QXLReleaseInfo {
> +typedef union SPICE_ATTR_PACKED QXLReleaseInfo {
>       uint64_t id;      // in
>       uint64_t next;    // out
>   } QXLReleaseInfo;