[dpdk-dev] [PATCH] mark experimental variables

[David Marchand <david.marchand@redhat.com>]

So far, we did not pay attention to direct access to variables but they
are part of the API/ABI too and should be clearly identified.

Introduce a __rte_experimental_var tag and mark existing exported
variables.

Fixes: a4bcd61de82d ("buildtools: add script to check experimental API exports")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changelog since RFC:
- s/resp\./or/ in documentation,
- caught more variables by looking at the *COM* section,

---
 buildtools/check-experimental-syms.sh      | 17 +++++++++++++++--
 devtools/checkpatches.sh                   | 16 ++++++++++++----
 doc/guides/contributing/abi_policy.rst     |  7 ++++---
 drivers/net/ice/rte_pmd_ice.h              |  8 ++++++++
 lib/librte_bbdev/rte_bbdev.h               |  1 +
 lib/librte_cryptodev/rte_crypto_asym.h     |  3 +++
 lib/librte_eal/common/include/rte_compat.h |  5 +++++
 lib/librte_ethdev/rte_flow.h               | 17 +++++++++++++++++
 lib/librte_port/rte_port_eventdev.h        |  5 +++++
 lib/librte_rcu/rte_rcu_qsbr.h              |  1 +
 10 files changed, 71 insertions(+), 9 deletions(-)

diff --git a/buildtools/check-experimental-syms.sh b/buildtools/check-experimental-syms.sh
index f3603e5ba..f3a2f92fb 100755
--- a/buildtools/check-experimental-syms.sh
+++ b/buildtools/check-experimental-syms.sh
@@ -34,13 +34,26 @@ do
 		Please add __rte_experimental to the definition of $SYM
 		END_OF_MESSAGE
 		ret=1
+	elif grep -qe "\(\.data\|\*COM\*\).*[[:space:]]$SYM$" $DUMPFILE &&
+		! grep -q "\.data\.experimental.*[[:space:]]$SYM$" $DUMPFILE
+	then
+		cat >&2 <<- END_OF_MESSAGE
+		$SYM is not flagged as experimental
+		but is listed in version map
+		Please add __rte_experimental_var to the definition of $SYM
+		END_OF_MESSAGE
+		ret=1
 	fi
 done
 
 # Filter out symbols suffixed with a . for icc
 for SYM in `awk '{
-	if ($2 != "l" && $4 == ".text.experimental" && !($NF ~ /\.$/)) {
-		print $NF
+	if ($2 == "l" || $NF ~ /\.$/) {
+		next;
+	}
+	if ($4 == ".text.experimental" ||
+	    $4 == ".data.experimental") {
+		print $NF;
 	}
 }' $DUMPFILE`
 do
diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index b16bace92..92b0ae40a 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh
@@ -90,11 +90,19 @@ check_experimental_tags() { # <patch>
 				"headers ("current_file")";
 			ret = 1;
 		}
-		if ($1 != "+__rte_experimental" || $2 != "") {
+
+		if (NF == 1 && ($1 == "+__rte_experimental" ||
+				$1 == "+__rte_experimental_var")) {
+			next;
+		}
+		if ($0 ~ "__rte_experimental_var") {
+			print "__rte_experimental_var must appear alone on the line" \
+				" immediately preceding the type of a variable.";
+		} else {
 			print "__rte_experimental must appear alone on the line" \
-				" immediately preceding the return type of a function."
-			ret = 1;
+				" immediately preceding the return type of a function.";
 		}
+		ret = 1;
 	}
 	END {
 		exit ret;
@@ -178,7 +186,7 @@ check () { # <patch> <commit> <title>
 		ret=1
 	fi
 
-	! $verbose || printf '\nChecking __rte_experimental tags:\n'
+	! $verbose || printf '\nChecking __rte_experimental* tags:\n'
 	report=$(check_experimental_tags "$tmpinput")
 	if [ $? -ne 0 ] ; then
 		$headline_printed || print_headline "$3"
diff --git a/doc/guides/contributing/abi_policy.rst b/doc/guides/contributing/abi_policy.rst
index 05ca95980..f933234d6 100644
--- a/doc/guides/contributing/abi_policy.rst
+++ b/doc/guides/contributing/abi_policy.rst
@@ -300,9 +300,10 @@ Note that marking an API as experimental is a multi step process.
 To mark an API as experimental, the symbols which are desired to be exported
 must be placed in an EXPERIMENTAL version block in the corresponding libraries'
 version map script.
-Secondly, the corresponding prototypes of those exported functions (in the
-development header files), must be marked with the ``__rte_experimental`` tag
-(see ``rte_compat.h``).
+Secondly, the corresponding prototypes of those exported functions (or
+variables) must be marked with the ``__rte_experimental`` (or
+``__rte_experimental_var``) tag in the development header files (see
+``rte_compat.h``).
 The DPDK build makefiles perform a check to ensure that the map file and the
 C code reflect the same list of symbols.
 This check can be circumvented by defining ``ALLOW_EXPERIMENTAL_API``
diff --git a/drivers/net/ice/rte_pmd_ice.h b/drivers/net/ice/rte_pmd_ice.h
index e254db053..a5c80c43c 100644
--- a/drivers/net/ice/rte_pmd_ice.h
+++ b/drivers/net/ice/rte_pmd_ice.h
@@ -15,6 +15,8 @@
  */
 
 #include <stdio.h>
+
+#include <rte_compat.h>
 #include <rte_mbuf.h>
 #include <rte_mbuf_dyn.h>
 
@@ -81,13 +83,19 @@ union rte_net_ice_proto_xtr_metadata {
 };
 
 /* Offset of mbuf dynamic field for protocol extraction data */
+__rte_experimental_var
 extern int rte_net_ice_dynfield_proto_xtr_metadata_offs;
 
 /* Mask of mbuf dynamic flags for protocol extraction type */
+__rte_experimental_var
 extern uint64_t rte_net_ice_dynflag_proto_xtr_vlan_mask;
+__rte_experimental_var
 extern uint64_t rte_net_ice_dynflag_proto_xtr_ipv4_mask;
+__rte_experimental_var
 extern uint64_t rte_net_ice_dynflag_proto_xtr_ipv6_mask;
+__rte_experimental_var
 extern uint64_t rte_net_ice_dynflag_proto_xtr_ipv6_flow_mask;
+__rte_experimental_var
 extern uint64_t rte_net_ice_dynflag_proto_xtr_tcp_mask;
 
 /**
diff --git a/lib/librte_bbdev/rte_bbdev.h b/lib/librte_bbdev/rte_bbdev.h
index 591fb7914..e044dec88 100644
--- a/lib/librte_bbdev/rte_bbdev.h
+++ b/lib/librte_bbdev/rte_bbdev.h
@@ -466,6 +466,7 @@ struct __rte_cache_aligned rte_bbdev {
 };
 
 /** @internal array of all devices */
+__rte_experimental_var
 extern struct rte_bbdev rte_bbdev_devices[];
 
 /**
diff --git a/lib/librte_cryptodev/rte_crypto_asym.h b/lib/librte_cryptodev/rte_crypto_asym.h
index 0d34ce8df..d4e84910f 100644
--- a/lib/librte_cryptodev/rte_crypto_asym.h
+++ b/lib/librte_cryptodev/rte_crypto_asym.h
@@ -24,6 +24,7 @@ extern "C" {
 #include <rte_memory.h>
 #include <rte_mempool.h>
 #include <rte_common.h>
+#include <rte_compat.h>
 
 #include "rte_crypto_sym.h"
 
@@ -37,10 +38,12 @@ typedef struct rte_crypto_param_t {
 } rte_crypto_param;
 
 /** asym xform type name strings */
+__rte_experimental_var
 extern const char *
 rte_crypto_asym_xform_strings[];
 
 /** asym operations type name strings */
+__rte_experimental_var
 extern const char *
 rte_crypto_asym_op_strings[];
 
diff --git a/lib/librte_eal/common/include/rte_compat.h b/lib/librte_eal/common/include/rte_compat.h
index 3eb33784b..3fd05179f 100644
--- a/lib/librte_eal/common/include/rte_compat.h
+++ b/lib/librte_eal/common/include/rte_compat.h
@@ -11,11 +11,16 @@
 #define __rte_experimental \
 __attribute__((deprecated("Symbol is not yet part of stable ABI"), \
 section(".text.experimental")))
+#define __rte_experimental_var \
+__attribute__((deprecated("Symbol is not yet part of stable ABI"), \
+section(".data.experimental")))
 
 #else
 
 #define __rte_experimental \
 __attribute__((section(".text.experimental")))
+#define __rte_experimental_var \
+__attribute__((section(".data.experimental")))
 
 #endif
 
diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
index 452d359a1..c8ea71acc 100644
--- a/lib/librte_ethdev/rte_flow.h
+++ b/lib/librte_ethdev/rte_flow.h
@@ -19,6 +19,7 @@
 
 #include <rte_arp.h>
 #include <rte_common.h>
+#include <rte_compat.h>
 #include <rte_ether.h>
 #include <rte_icmp.h>
 #include <rte_ip.h>
@@ -2531,9 +2532,11 @@ struct rte_flow_action_set_meta {
 };
 
 /* Mbuf dynamic field offset for metadata. */
+__rte_experimental_var
 extern int rte_flow_dynf_metadata_offs;
 
 /* Mbuf dynamic field flag mask for metadata. */
+__rte_experimental_var
 extern uint64_t rte_flow_dynf_metadata_mask;
 
 /* Mbuf dynamic field pointer for metadata. */
@@ -2548,14 +2551,24 @@ __rte_experimental
 static inline uint32_t
 rte_flow_dynf_metadata_get(struct rte_mbuf *m)
 {
+#ifdef ALLOW_EXPERIMENTAL_API
 	return *RTE_FLOW_DYNF_METADATA(m);
+#else
+	RTE_SET_USED(m);
+	return 0;
+#endif
 }
 
 __rte_experimental
 static inline void
 rte_flow_dynf_metadata_set(struct rte_mbuf *m, uint32_t v)
 {
+#ifdef ALLOW_EXPERIMENTAL_API
 	*RTE_FLOW_DYNF_METADATA(m) = v;
+#else
+	RTE_SET_USED(m);
+	RTE_SET_USED(v);
+#endif
 }
 
 /*
@@ -2800,7 +2813,11 @@ __rte_experimental
 static inline int
 rte_flow_dynf_metadata_avail(void)
 {
+#ifdef ALLOW_EXPERIMENTAL_API
 	return !!rte_flow_dynf_metadata_mask;
+#else
+	return 0;
+#endif
 }
 
 /**
diff --git a/lib/librte_port/rte_port_eventdev.h b/lib/librte_port/rte_port_eventdev.h
index acf88f4e9..59246e204 100644
--- a/lib/librte_port/rte_port_eventdev.h
+++ b/lib/librte_port/rte_port_eventdev.h
@@ -25,6 +25,8 @@ extern "C" {
 **/
 
 #include <stdint.h>
+
+#include <rte_compat.h>
 #include <rte_eventdev.h>
 
 #include "rte_port.h"
@@ -39,6 +41,7 @@ struct rte_port_eventdev_reader_params {
 };
 
 /** Eventdev_reader port operations. */
+__rte_experimental_var
 extern struct rte_port_in_ops rte_port_eventdev_reader_ops;
 
 /** Eventdev_writer port parameters. */
@@ -63,6 +66,7 @@ struct rte_port_eventdev_writer_params {
 };
 
 /** Eventdev_writer port operations. */
+__rte_experimental_var
 extern struct rte_port_out_ops rte_port_eventdev_writer_ops;
 
 /** Event_writer_nodrop port parameters. */
@@ -90,6 +94,7 @@ struct rte_port_eventdev_writer_nodrop_params {
 };
 
 /** Eventdev_writer_nodrop port operations. */
+__rte_experimental_var
 extern struct rte_port_out_ops rte_port_eventdev_writer_nodrop_ops;
 
 #ifdef __cplusplus
diff --git a/lib/librte_rcu/rte_rcu_qsbr.h b/lib/librte_rcu/rte_rcu_qsbr.h
index 0b5585925..55c100673 100644
--- a/lib/librte_rcu/rte_rcu_qsbr.h
+++ b/lib/librte_rcu/rte_rcu_qsbr.h
@@ -35,6 +35,7 @@ extern "C" {
 #include <rte_debug.h>
 #include <rte_atomic.h>
 
+__rte_experimental_var
 extern int rte_rcu_log_type;
 
 #if RTE_LOG_DP_LEVEL >= RTE_LOG_DEBUG
-- 
2.23.0