[dpdk-dev] [PATCH v2] eal/stack: fix 'pointer-sign' warning

[Phil Yang]

clang raise 'pointer-sign' warnings in __atomic_compare_exchange
when passing 'uint64_t *' to parameter of type 'int64_t *' converts
between pointers to integer types with different sign.

Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")

Suggested-by: Gage Eads <gage.eads at intel.com>
Signed-off-by: Phil Yang <phil.yang at arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Reviewed-by: Gavin Hu <gavin.hu at arm.com>

---
 lib/librte_stack/rte_stack.h            | 2 +-
 lib/librte_stack/rte_stack_lf_c11.h     | 8 ++++----
 lib/librte_stack/rte_stack_lf_generic.h | 7 ++++---
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/lib/librte_stack/rte_stack.h b/lib/librte_stack/rte_stack.h
index fe048f0..93c360c 100644
--- a/lib/librte_stack/rte_stack.h
+++ b/lib/librte_stack/rte_stack.h
@@ -47,7 +47,7 @@ struct rte_stack_lf_list {
 	/** List head */
 	struct rte_stack_lf_head head __rte_aligned(16);
 	/** List len */
-	rte_atomic64_t len;
+	uint64_t len;
 };
 
 /* Structure containing two lock-free LIFO lists: the stack itself and a list
diff --git a/lib/librte_stack/rte_stack_lf_c11.h b/lib/librte_stack/rte_stack_lf_c11.h
index a316e9a..3d677ae 100644
--- a/lib/librte_stack/rte_stack_lf_c11.h
+++ b/lib/librte_stack/rte_stack_lf_c11.h
@@ -26,7 +26,7 @@ __rte_stack_lf_count(struct rte_stack *s)
 	 * elements. If the mempool is near-empty to the point that this is a
 	 * concern, the user should consider increasing the mempool size.
 	 */
-	return (unsigned int)__atomic_load_n(&s->stack_lf.used.len.cnt,
+	return (unsigned int)__atomic_load_n(&s->stack_lf.used.len,
 					     __ATOMIC_RELAXED);
 }
 
@@ -78,7 +78,7 @@ __rte_stack_lf_push_elems(struct rte_stack_lf_list *list,
 	/* Ensure the stack modifications are not reordered with respect
 	 * to the LIFO len update.
 	 */
-	__atomic_add_fetch(&list->len.cnt, num, __ATOMIC_RELEASE);
+	__atomic_add_fetch(&list->len, num, __ATOMIC_RELEASE);
 #endif
 }
 
@@ -101,7 +101,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list,
 	int success;
 
 	/* Reserve num elements, if available */
-	len = __atomic_load_n(&list->len.cnt, __ATOMIC_ACQUIRE);
+	len = __atomic_load_n(&list->len, __ATOMIC_ACQUIRE);
 
 	while (1) {
 		/* Does the list contain enough elements? */
@@ -109,7 +109,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list,
 			return NULL;
 
 		/* len is updated on failure */
-		if (__atomic_compare_exchange_n(&list->len.cnt,
+		if (__atomic_compare_exchange_n(&list->len,
 						&len, len - num,
 						0, __ATOMIC_ACQUIRE,
 						__ATOMIC_ACQUIRE))
diff --git a/lib/librte_stack/rte_stack_lf_generic.h b/lib/librte_stack/rte_stack_lf_generic.h
index 1191406..3182151 100644
--- a/lib/librte_stack/rte_stack_lf_generic.h
+++ b/lib/librte_stack/rte_stack_lf_generic.h
@@ -26,7 +26,8 @@ __rte_stack_lf_count(struct rte_stack *s)
 	 * elements. If the mempool is near-empty to the point that this is a
 	 * concern, the user should consider increasing the mempool size.
 	 */
-	return (unsigned int)rte_atomic64_read(&s->stack_lf.used.len);
+	return (unsigned int)rte_atomic64_read((rte_atomic64_t *)
+			&s->stack_lf.used.len);
 }
 
 static __rte_always_inline void
@@ -73,7 +74,7 @@ __rte_stack_lf_push_elems(struct rte_stack_lf_list *list,
 				__ATOMIC_RELAXED);
 	} while (success == 0);
 
-	rte_atomic64_add(&list->len, num);
+	rte_atomic64_add((rte_atomic64_t *)&list->len, num);
 #endif
 }
 
@@ -96,7 +97,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list,
 
 	/* Reserve num elements, if available */
 	while (1) {
-		uint64_t len = rte_atomic64_read(&list->len);
+		uint64_t len = rte_atomic64_read((rte_atomic64_t *)&list->len);
 
 		/* Does the list contain enough elements? */
 		if (unlikely(len < num))
-- 
2.7.4