[Spice-devel] [PATCH spice-protocol] vd_agent: Do not define structures without fields

[Frediano Ziglio]

> 
> According to C standard the size of a structure without fields is
> not defined (see
> https://stackoverflow.com/questions/21851930/size-of-empty-structure-in-c-and-c).
> As use almost use GCC we used these structures having 0-size. This is

As we almost only use GCC ...

> usually not a problem however can became a problem if 2 side talking

side -> sides

> a given protocol uses these structures.

uses -> use

> To avoid such possible mismatch (for instance having one side C and the
> other C++ which define these structure as having 1 as size) add an

define -> defines, structure -> structures

> empty (0-size array) field.
> Although a 0-size array is not considered also that portable we use
> extensively this feature with different compiler never encountering

compiler -> compilers

> issues.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>

I should have checked before sending.

> ---
>  spice/vd_agent.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/spice/vd_agent.h b/spice/vd_agent.h
> index 7109ede..dda7044 100644
> --- a/spice/vd_agent.h
> +++ b/spice/vd_agent.h
> @@ -234,6 +234,7 @@ typedef struct SPICE_ATTR_PACKED VDAgentClipboardRelease
> {
>      uint8_t selection;
>      uint8_t __reserved[sizeof(uint32_t) - 1 * sizeof(uint8_t)];
>  #endif
> +    uint8_t dummy_empty_field[0]; /* C/C++ compatibility */
>  } VDAgentClipboardRelease;
>  
>  typedef struct SPICE_ATTR_PACKED VDAgentMaxClipboard {

Frediano