[PATCH] bpf: remove dependency on vla

[PATCH] bpf: remove dependency on vla

[Stephen Hemminger]

The code for ethdev callbacks was using variable length arrays
which is a feature not supported on MSVC and later C standards.
Replace with alloca().

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/bpf/bpf_pkt.c   | 16 +++++++++-------
 lib/bpf/meson.build |  2 --
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/bpf/bpf_pkt.c b/lib/bpf/bpf_pkt.c
index 01f813c56b..6a425d79b6 100644
--- a/lib/bpf/bpf_pkt.c
+++ b/lib/bpf/bpf_pkt.c
@@ -6,6 +6,7 @@
 #include <string.h>
 #include <errno.h>
 #include <stdint.h>
+#include <alloca.h>
 
 #include <sys/queue.h>
 
@@ -163,10 +164,11 @@ apply_filter(struct rte_mbuf *mb[], const uint64_t rc[], uint32_t num,
 	uint32_t drop)
 {
 	uint32_t i, j, k;
-	struct rte_mbuf *dr[num];
+	struct rte_mbuf **dr;
 
-	for (i = 0, j = 0, k = 0; i != num; i++) {
+	dr = alloca(sizeof(struct rte_mbuf *) * num);
 
+	for (i = 0, j = 0, k = 0; i != num; i++) {
 		/* filter matches */
 		if (rc[i] != 0)
 			mb[j++] = mb[i];
@@ -193,8 +195,8 @@ pkt_filter_vm(const struct rte_bpf *bpf, struct rte_mbuf *mb[], uint32_t num,
 	uint32_t drop)
 {
 	uint32_t i;
-	void *dp[num];
-	uint64_t rc[num];
+	void **dp = alloca(sizeof(void *) * num);
+	uint64_t *rc = alloca(sizeof(uint64_t) * num);
 
 	for (i = 0; i != num; i++)
 		dp[i] = rte_pktmbuf_mtod(mb[i], void *);
@@ -209,7 +211,7 @@ pkt_filter_jit(const struct rte_bpf_jit *jit, struct rte_mbuf *mb[],
 {
 	uint32_t i, n;
 	void *dp;
-	uint64_t rc[num];
+	uint64_t *rc = alloca(sizeof(uint64_t) * num);
 
 	n = 0;
 	for (i = 0; i != num; i++) {
@@ -228,7 +230,7 @@ static inline uint32_t
 pkt_filter_mb_vm(const struct rte_bpf *bpf, struct rte_mbuf *mb[], uint32_t num,
 	uint32_t drop)
 {
-	uint64_t rc[num];
+	uint64_t *rc = alloca(sizeof(uint64_t) * num);
 
 	rte_bpf_exec_burst(bpf, (void **)mb, rc, num);
 	return apply_filter(mb, rc, num, drop);
@@ -239,7 +241,7 @@ pkt_filter_mb_jit(const struct rte_bpf_jit *jit, struct rte_mbuf *mb[],
 	uint32_t num, uint32_t drop)
 {
 	uint32_t i, n;
-	uint64_t rc[num];
+	uint64_t *rc = alloca(sizeof(uint64_t) * num);
 
 	n = 0;
 	for (i = 0; i != num; i++) {
diff --git a/lib/bpf/meson.build b/lib/bpf/meson.build
index 28df7f469a..aa258a9061 100644
--- a/lib/bpf/meson.build
+++ b/lib/bpf/meson.build
@@ -7,8 +7,6 @@ if is_windows
     subdir_done()
 endif
 
-cflags += no_wvla_cflag
-
 if arch_subdir == 'x86' and dpdk_conf.get('RTE_ARCH_32')
     build = false
     reason = 'not supported on 32-bit x86'
-- 
2.47.2