[ovs-dev] [warnings 2/3] Avoid warnings about comparisons that are always true.

[Ethan Jackson]

Looks Good.

On Fri, Apr 15, 2011 at 9:41 AM, Ben Pfaff <blp at nicira.com> wrote:
> The range of "enum" types varies from one ABI to another.  If the enums
> being tested in these functions happen to be 16 bits wide, then GCC may
> issue a warning because, in such a case, the comparison is always true.
>
> Using an int instead of a uint16_t avoids that particular problem and
> should suppress the warning.
>
> Fixes the following reported warnings:
>
> lib/ofp-print.c:240: warning: comparison is always true due to limited
> range of data type
> lib/ofp-util.c:1973: warning: comparison is always false due to limited
> range of data type
>
> Reported-by: YAMAMOTO Takashi <yamamoto at valinux.co.jp>
> ---
>  lib/ofp-print.c |    4 ++--
>  lib/ofp-util.c  |    7 +++----
>  2 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/lib/ofp-print.c b/lib/ofp-print.c
> index 6560f32..30f6d37 100644
> --- a/lib/ofp-print.c
> +++ b/lib/ofp-print.c
> @@ -227,7 +227,7 @@ nx_action_len(enum nx_action_subtype subtype)
>  static void
>  ofp_print_nx_action(struct ds *string, const struct nx_action_header *nah)
>  {
> -    uint16_t subtype = ntohs(nah->subtype);
> +    int subtype = ntohs(nah->subtype);
>     int required_len = nx_action_len(subtype);
>     int len = ntohs(nah->len);
>
> @@ -312,7 +312,7 @@ ofp_print_nx_action(struct ds *string, const struct nx_action_header *nah)
>         }
>     }
>
> -    ds_put_format(string, "***unknown Nicira action:%"PRIu16"***", subtype);
> +    ds_put_format(string, "***unknown Nicira action:%d***", subtype);
>  }
>
>  static int
> diff --git a/lib/ofp-util.c b/lib/ofp-util.c
> index c49b079..bcaf3dd 100644
> --- a/lib/ofp-util.c
> +++ b/lib/ofp-util.c
> @@ -1959,7 +1959,7 @@ check_nicira_action(const union ofp_action *a, unsigned int len,
>                     const struct flow *flow)
>  {
>     const struct nx_action_header *nah;
> -    uint16_t subtype;
> +    int subtype;
>     int error;
>
>     if (len < 16) {
> @@ -1971,7 +1971,7 @@ check_nicira_action(const union ofp_action *a, unsigned int len,
>
>     subtype = ntohs(nah->subtype);
>     if (subtype > TYPE_MAXIMUM(enum nx_action_subtype)) {
> -        /* This is necessary because enum nx_action_subtype is probably an
> +        /* This is necessary because enum nx_action_subtype may be an
>          * 8-bit type, so the cast below throws away the top 8 bits. */
>         return ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_VENDOR_TYPE);
>     }
> @@ -2026,8 +2026,7 @@ check_nicira_action(const union ofp_action *a, unsigned int len,
>     case NXAST_SNAT__OBSOLETE:
>     default:
>         VLOG_WARN_RL(&bad_ofmsg_rl,
> -                     "unknown Nicira vendor action subtype %"PRIu16,
> -                     ntohs(nah->subtype));
> +                     "unknown Nicira vendor action subtype %d", subtype);
>         return ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_VENDOR_TYPE);
>     }
>  }
> --
> 1.7.1
>
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