mbuf: fix C++ build on void pointer cast

Including rte_mbuf.h in C++ triggers the following warning as C++ does not
allow implicit casting of a void *.

In file included from test.cpp:1:0:
rte_mbuf.h: In function ‘rte_mbuf_ext_shared_info*
rte_pktmbuf_ext_shinfo_init_helper(void*, uint16_t*,
rte_mbuf_extbuf_free_callback_t, void*)’:
rte_mbuf.h:1349:9: error: invalid conversion
from ‘void*’ to ‘rte_mbuf_ext_shared_info*’ [-fpermissive]
  shinfo = RTE_PTR_ALIGN_FLOOR(RTE_PTR_SUB(buf_end,
         ^

Fixes: a53aa2b9f3be ("mbuf: support attaching external buffer")

Signed-off-by: David Marchand <david.marchand@6wind.com>

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 4fd9a0d..eab13c6 100644 (file)
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -1345,12 +1345,14 @@ rte_pktmbuf_ext_shinfo_init_helper(void *buf_addr, uint16_t *buf_len,
 {
        struct rte_mbuf_ext_shared_info *shinfo;
        void *buf_end = RTE_PTR_ADD(buf_addr, *buf_len);
+       void *addr;
 
-       shinfo = RTE_PTR_ALIGN_FLOOR(RTE_PTR_SUB(buf_end,
-                               sizeof(*shinfo)), sizeof(uintptr_t));
-       if ((void *)shinfo <= buf_addr)
+       addr = RTE_PTR_ALIGN_FLOOR(RTE_PTR_SUB(buf_end, sizeof(*shinfo)),
+                                  sizeof(uintptr_t));
+       if (addr <= buf_addr)
                return NULL;
 
+       shinfo = (struct rte_mbuf_ext_shared_info *)addr;
        shinfo->free_cb = free_cb;
        shinfo->fcb_opaque = fcb_opaque;
        rte_mbuf_ext_refcnt_set(shinfo, 1);