Re: [PATCH v2 1/2] tools/xenstore: add const to the return type of canonicalize()

[Julien Grall <julien@xxxxxxx>]

Hi Juergen,

On 22/07/2023 09:16, Juergen Gross wrote:
> -static struct watch *add_watch(struct connection *conn, char *path, char 
> *token,
> -                              bool relative, bool no_quota_check)
> +static struct watch *add_watch(struct connection *conn, const char *path,
> +                              const char *token, bool relative,
> +                              bool no_quota_check)
>   {
>         struct watch *watch;
>   
> @@ -218,12 +219,14 @@ int do_watch(const void *ctx, struct connection *conn, struct buffered_data *in)
>   {
>         struct watch *watch;
>         char *vec[2];
> +       const char *path;
>         bool relative;
>   
>   	if (get_strings(in, vec, ARRAY_SIZE(vec)) != ARRAY_SIZE(vec))
>                 return EINVAL;
>   
> -	errno = check_watch_path(conn, ctx, &(vec[0]), &relative);
> +       path = vec[0];
> +       errno = check_watch_path(conn, ctx, &path, &relative);
From my understanding, check_watch_path() could update vec[0] which is 
then used below. But with your change, vec[0] would not be updated anymore.
I can see two possible approach:
   1) get_strings() is taking a const as well
   2) replace all use of vec[0] with path

I have a slight preference for the former. But I can also understand 
this is more work. So choose whichever you prefer.
Cheers,

--
Julien Grall