[dpdk-dev] [PATCH 1/2] ring: fix declaration after code

[Andy Green <andy@warmcat.com>]

On gcc 5.4.0 / native aarch64 from Ubuntu 16.04:

/home/agreen/lagopus/src/dpdk/build/include/
rte_ring_c11_mem.h: In function
'__rte_ring_move_prod_head':
/home/agreen/lagopus/src/dpdk/build/include/
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;
   ^
/home/agreen/lagopus/src/dpdk/build/include/
rte_ring_c11_mem.h: In function
'__rte_ring_move_cons_head':
/home/agreen/lagopus/src/dpdk/build/include/
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;
   ^

Signed-off-by: Andy Green <andy@warmcat.com>
Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
---
 lib/librte_ring/rte_ring_c11_mem.h |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/librte_ring/rte_ring_c11_mem.h b/lib/librte_ring/rte_ring_c11_mem.h
index cb3f82b1a..3cc339558 100644
--- a/lib/librte_ring/rte_ring_c11_mem.h
+++ b/lib/librte_ring/rte_ring_c11_mem.h
@@ -61,12 +61,14 @@ __rte_ring_move_prod_head(struct rte_ring *r, unsigned int is_sp,
 	int success;
 
 	do {
+		const uint32_t cons_tail = r->cons.tail;
+
 		/* Reset n to the initial burst count */
 		n = max;
 
 		*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
@@ -129,11 +131,13 @@ __rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
 
 	/* move cons.head atomically */
 	do {
+		const uint32_t prod_tail = r->prod.tail;
+
 		/* Restore n as it may change every loop */
 		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