[dpdk-dev] [PATCH v5 01/32] net/mlx5: fix folding constant array error

[Tal Shnaiderman]

Before this commit the PMD used:
   const int elt_n = 8
   const int *stack[elt_n];

In Windows clang compiler complains:
net/mlx5/mlx5_flow.c:215:19: error: variable length array folded
to constant array as an extension [-Werror,-Wgnu-folding-constant]

Fix it by using a constant macro definition instead of a variable:
   #define MLX5_RSS_EXP_ELT_N 8
   const int *stack[MLX5_RSS_EXP_ELT_N];

Fixes: c7870bfe09dc ("ethdev: move RSS expansion code to mlx5 driver")
Cc: sta...@dpdk.org

Signed-off-by: Tal Shnaiderman <tal...@nvidia.com>
Signed-off-by: Ophir Munk <ophi...@nvidia.com>
Acked-by: Matan Azrad <ma...@nvidia.com>
---
 drivers/net/mlx5/mlx5_flow.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 82e24d7067..bf86aaaa39 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -212,6 +212,8 @@ mlx5_flow_expand_rss_item_complete(const struct 
rte_flow_item *item)
        return ret;
 }
 
+#define MLX5_RSS_EXP_ELT_N 8
+
 /**
  * Expand RSS flows into several possible flows according to the RSS hash
  * fields requested and the driver capabilities.
@@ -242,13 +244,12 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, 
size_t size,
                     const struct mlx5_flow_expand_node graph[],
                     int graph_root_index)
 {
-       const int elt_n = 8;
        const struct rte_flow_item *item;
        const struct mlx5_flow_expand_node *node = &graph[graph_root_index];
        const int *next_node;
-       const int *stack[elt_n];
+       const int *stack[MLX5_RSS_EXP_ELT_N];
        int stack_pos = 0;
-       struct rte_flow_item flow_items[elt_n];
+       struct rte_flow_item flow_items[MLX5_RSS_EXP_ELT_N];
        unsigned int i;
        size_t lsize;
        size_t user_pattern_size = 0;
@@ -261,10 +262,10 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, 
size_t size,
 
        memset(&missed_item, 0, sizeof(missed_item));
        lsize = offsetof(struct mlx5_flow_expand_rss, entry) +
-               elt_n * sizeof(buf->entry[0]);
+               MLX5_RSS_EXP_ELT_N * sizeof(buf->entry[0]);
        if (lsize <= size) {
                buf->entry[0].priority = 0;
-               buf->entry[0].pattern = (void *)&buf->entry[elt_n];
+               buf->entry[0].pattern = (void *)&buf->entry[MLX5_RSS_EXP_ELT_N];
                buf->entries = 0;
                addr = buf->entry[0].pattern;
        }
@@ -367,7 +368,7 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, 
size_t size,
                /* Go deeper. */
                if (node->next) {
                        next_node = node->next;
-                       if (stack_pos++ == elt_n) {
+                       if (stack_pos++ == MLX5_RSS_EXP_ELT_N) {
                                rte_errno = E2BIG;
                                return -rte_errno;
                        }
-- 
2.16.1.windows.4