[sheepdog] [PATCH v2] lib: fix compiler error in logger.c

[Liu Yuan]

On Thu, Feb 13, 2014 at 05:03:12PM +0800, Robin Dong wrote:
> From: Robin Dong <sanbai at taobao.com>
> 
> When build sheepdog in centos6, it will report:
> 
>     logger.c: In function ‘gdb_cmd’:
>     logger.c:746: error: ‘ARG_MAX’ undeclared (first use in this function)
>     logger.c:746: error: (Each undeclared identifier is reported only once
>     logger.c:746: error: for each function it appears in.)
>     logger.c:746: warning: unused variable ‘cmd_str’
>     logger.c: In function ‘sd_backtrace’:
>     logger.c:797: error: ‘ARG_MAX’ undeclared (first use in this function)
>     logger.c:797: warning: unused variable ‘cmd’
> 
> the reason has been explained here: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=518858
> and the standard revolution is using 'sysconf()'.
> 
> Signed-off-by: Robin Dong <sanbai at taobao.com>
> ---
>  lib/logger.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/lib/logger.c b/lib/logger.c
> index 8be2bfd..267b87d 100644
> --- a/lib/logger.c
> +++ b/lib/logger.c
> @@ -741,6 +741,8 @@ static bool check_gdb(void)
>  	return system("which gdb > /dev/null") == 0;
>  }
>  
> +#define ARG_MAX (sysconf(_SC_ARG_MAX))
> +

ARG_MAX is actually defined correctly on my ubuntu 13.04. I'd suggest name it as
SD_ARG_MAX.

Thanks
Yuan