[dpdk-dev] [PATCH 01/18] lib: ret_table: workaround hash function cast error

[Andy Green <andy@warmcat.com>]

/home/agreen/projects/dpdk/lib/librte_table/rte_table_hash_cuckoo.c:110:16: error: cast between incompatible function types from ‘rte_table_hash_op_hash’ {aka ‘long unsigned int (*)(void *, void *, unsigned int,  long unsigned int)’} to ‘uint32_t (*)(const void *, uint32_t,  uint32_t)’ {aka ‘unsigned int (*)(const void *, unsigned int,  unsigned int)’} [-Werror=cast-function-type]
   .hash_func = (rte_hash_function)(p->f_hash),

The code seems to be quite broken.

It's casting this

typedef uint64_t (*rte_table_hash_op_hash)(
        void *key,
        void *key_mask,
        uint32_t key_size,
        uint64_t seed);

to this

typedef uint32_t (*rte_hash_function)(const void *key, uint32_t key_len,
                                      uint32_t init_val);

if the definition with 4 args is later called with a pointer
giving it three args, obviously it working is just an accident.  I
grepped around a bit and could not see it being cast back to
the original type before use; the uses I saw have three args.

I simply patch it to stop the build breaking, rather than fix it,
since I am not sure what a fix should look like considering the
whole code.
---
 lib/librte_table/rte_table_hash_cuckoo.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_table/rte_table_hash_cuckoo.c b/lib/librte_table/rte_table_hash_cuckoo.c
index dcb4fe978..eca72b506 100644
--- a/lib/librte_table/rte_table_hash_cuckoo.c
+++ b/lib/librte_table/rte_table_hash_cuckoo.c
@@ -107,7 +107,7 @@ rte_table_hash_cuckoo_create(void *params,
 	struct rte_hash_parameters hash_cuckoo_params = {
 		.entries = p->n_keys,
 		.key_len = p->key_size,
-		.hash_func = (rte_hash_function)(p->f_hash),
+		.hash_func = (rte_hash_function)(void *)(p->f_hash),
 		.hash_func_init_val = p->seed,
 		.socket_id = socket_id,
 		.name = p->name