[Spice-devel] [PATCH v2 2/2] Define and use new SPICE_MAGIC_CONST macro

[Christophe Fergeau]

On Tue, Aug 11, 2015 at 11:14:07AM -0400, Frediano Ziglio wrote:
> This macro allow to define magic constants without using weird
> memory tweacks.
> This remove some possible warning from some compiler and
> make code more optimized as compiler is able to compute the
> constant.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
> 
> Did a mistake with the macros (parenthesis mismatch).
> Tested the method also with Visual Studio 2008 compiler and works as expected.
> 
> 
>  spice/controller_prot.h   | 2 +-
>  spice/foreign_menu_prot.h | 2 +-
>  spice/macros.h            | 8 ++++++++
>  spice/protocol.h          | 2 +-
>  spice/qxl_dev.h           | 4 ++--
>  spice/stats.h             | 2 +-
>  spice/vdi_dev.h           | 2 +-
>  7 files changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/spice/controller_prot.h b/spice/controller_prot.h
> index bca7804..a21bf57 100644
> --- a/spice/controller_prot.h
> +++ b/spice/controller_prot.h
> @@ -21,7 +21,7 @@
>  #include <spice/types.h>
>  #include <spice/start-packed.h>
>  
> -#define CONTROLLER_MAGIC      (*(uint32_t*)"CTRL")
> +#define CONTROLLER_MAGIC      SPICE_MAGIC_CONST("CTRL")
>  #define CONTROLLER_VERSION    1
>  
>  
> diff --git a/spice/foreign_menu_prot.h b/spice/foreign_menu_prot.h
> index f478e2a..9dd882d 100644
> --- a/spice/foreign_menu_prot.h
> +++ b/spice/foreign_menu_prot.h
> @@ -21,7 +21,7 @@
>  #include <spice/types.h>
>  #include <spice/start-packed.h>
>  
> -#define FOREIGN_MENU_MAGIC      (*(uint32_t*)"FRGM")
> +#define FOREIGN_MENU_MAGIC      SPICE_MAGIC_CONST("FRGM")
>  #define FOREIGN_MENU_VERSION    1
>  
>  typedef struct SPICE_ATTR_PACKED FrgMenuInitHeader {
> diff --git a/spice/macros.h b/spice/macros.h
> index 3538989..679d68d 100644
> --- a/spice/macros.h
> +++ b/spice/macros.h
> @@ -414,4 +414,12 @@
>  #endif
>  
>  
> +#if SPICE_ENDIAN == SPICE_ENDIAN_LITTLE
> +#define SPICE_MAGIC_CONST(s) \
> +    ((uint32_t)((s[0]&0xffu)|((s[1]&0xffu)<<8)|((s[2]&0xff)<<16)|((s[3]&0xffu)<<24)))
> +#else
> +#define SPICE_MAGIC_CONST(s) \
> +    ((uint32_t)((s[3]&0xffu)|((s[2]&0xffu)<<8)|((s[1]&0xff)<<16)|((s[0]&0xffu)<<24)))
> +#endif

Is it expected that 3rd member (the one shifted by 16 bits) does not
have 0xffu ? Apart from this, ACK, so I can fix and push.

Christophe
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/spice-devel/attachments/20150811/3aed3240/attachment.sig>