Re: [Xen-devel] [PATCH] mini-os: make xenbus_read_integer and xenbus_printf take const strings

["Daniel P. Berrange" <berrange@xxxxxxxxxx>]

On Tue, Aug 26, 2008 at 05:17:02PM +0100, Samuel Thibault wrote:
> mini-os: make xenbus_read_integer and xenbus_printf take const strings
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxxx>
> 
> diff -r c2472ded5c7c extras/mini-os/include/xenbus.h
> --- a/extras/mini-os/include/xenbus.h Tue Aug 26 15:16:57 2008 +0100
> +++ b/extras/mini-os/include/xenbus.h Tue Aug 26 17:06:09 2008 +0100
> @@ -83,12 +83,12 @@ char *xenbus_transaction_end(xenbus_tran
>                            int *retry);
>  
>  /* Read path and parse it as an integer.  Returns -1 on error. */
> -int xenbus_read_integer(char *path);
> +int xenbus_read_integer(const char *path);
>  
>  /* Contraction of snprintf and xenbus_write(path/node). */
>  char* xenbus_printf(xenbus_transaction_t xbt,
> -                                  char* node, char* path,
> -                                  char* fmt, ...);
> +                                  const char* node, const char* path,
> +                                  const char* fmt, ...);

If you annotate that declaration with

   __attribute__ ((__format__ (printf, 4, 3)))

then gcc will warn you any time a caller gives incorrect args vs
format string, which can catch some otherwise hidden bugs.

Regards,
Daniel
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