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

[Ben Pfaff]

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