[libvirt] [PATCH v3] util: systemd: Define MSG_NOSIGNAL if needed

[Justin Clift]

On 20 Jul 2016, at 14:46, Andrea Bolognani <abologna at redhat.com> wrote:
> The symbol being missing has been reported as causing build
> failures on OS X. If it's not already defined, define it to
> zero so that it won't have any effect.
> ---
> Changes from v2:
> 
>  * define MSG_NOSIGNAL to zero if not already defined
>    instead of conditionally compiling the code depending
>    on it
> 
> src/util/virsystemd.c | 4 ++++
> 1 file changed, 4 insertions(+)
> 
> diff --git a/src/util/virsystemd.c b/src/util/virsystemd.c
> index 969cd68..7d6985b 100644
> --- a/src/util/virsystemd.c
> +++ b/src/util/virsystemd.c
> @@ -41,6 +41,10 @@
> 
> VIR_LOG_INIT("util.systemd");
> 
> +#ifndef MSG_NOSIGNAL
> +# define MSG_NOSIGNAL 0
> +#endif
> +
> static void virSystemdEscapeName(virBufferPtr buf,
>                                  const char *name)
> {
> -- 
> 2.7.4

This compiles fine on OSX too. :)

One niggle with it though... this is what is looks like in context:

*******************************************************************
...
#include "virerror.h"
#include "virfile.h"

#define VIR_FROM_THIS VIR_FROM_SYSTEMD

VIR_LOG_INIT("util.systemd");

#ifndef MSG_NOSIGNAL
# define MSG_NOSIGNAL 0
#endif

static void virSystemdEscapeName(virBufferPtr buf,
                                 const char *name)
{
    static const char hextable[16] = "0123456789abcdef";

#define ESCAPE(c)
...
*******************************************************************

Isn't it kind of crying out for a useful comment, so the next person
looking through this code has a good chance to understand why it's
there? ;)

Maybe something like:

/* OSX is missing MSG_NOSIGNAL, so we define it here to avoid
 * failure during building.
 */

:)

+ Justin

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