ring: fix declaration after statement

On gcc 5.4.0 / native aarch64 from Ubuntu 16.04:

In function '__rte_ring_move_prod_head':
rte_ring_c11_mem.h:69:3: warning:
ISO C90 forbids mixed declarations and code
[-Wdeclaration-after-statement]
   const uint32_t cons_tail = r->cons.tail;
   ^

In function '__rte_ring_move_cons_head':
rte_ring_c11_mem.h:136:3: warning:
ISO C90 forbids mixed declarations and code
[-Wdeclaration-after-statement]
   const uint32_t prod_tail = r->prod.tail;
   ^

Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/lib/librte_ring/rte_ring_c11_mem.h b/lib/librte_ring/rte_ring_c11_mem.h
index cb3f82b..94df3c4 100644 (file)
--- a/lib/librte_ring/rte_ring_c11_mem.h
+++ b/lib/librte_ring/rte_ring_c11_mem.h
@@ -66,14 +66,14 @@ __rte_ring_move_prod_head(struct rte_ring *r, unsigned int is_sp,
 
                *old_head = __atomic_load_n(&r->prod.head,
                                        __ATOMIC_ACQUIRE);
-               const uint32_t cons_tail = r->cons.tail;
+
                /*
                 *  The subtraction is done between two unsigned 32bits value
                 * (the result is always modulo 32 bits even if we have
                 * *old_head > cons_tail). So 'free_entries' is always between 0
                 * and capacity (which is < size).
                 */
-               *free_entries = (capacity + cons_tail - *old_head);
+               *free_entries = (capacity + r->cons.tail - *old_head);
 
                /* check that we have enough room in ring */
                if (unlikely(n > *free_entries))
@@ -133,13 +133,13 @@ __rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
                n = max;
                *old_head = __atomic_load_n(&r->cons.head,
                                        __ATOMIC_ACQUIRE);
-               const uint32_t prod_tail = r->prod.tail;
+
                /* The subtraction is done between two unsigned 32bits value
                 * (the result is always modulo 32 bits even if we have
                 * cons_head > prod_tail). So 'entries' is always between 0
                 * and size(ring)-1.
                 */
-               *entries = (prod_tail - *old_head);
+               *entries = (r->prod.tail - *old_head);
 
                /* Set the actual entries for dequeue */
                if (n > *entries)