api: enforce vla is last and fixed string type

Enforce that variable length fields are the last element of API messages.

Add a 'fixed' version of string type, since dealing with
multiple variable length strings turned out too painful
for the C language bindings.

The string type is now:
{
  string name[64]; // NUL terminated C-string. Essentially decays to u8 name[64]
  string name[];   // Variable length string with embedded len field (vl_api_string_t)
};

The latter notation could be made available to other types as well.
e.g.
{
  vl_api_address_t addresses[];
}
instead of

{
  u32 n_addr;
  vl_api_address_t addresses[n_addr];
};

Type: fix
Change-Id: I18fa17ef47227633752ab50453e8d20a652a9f9b
Signed-off-by: Ole Troan <ot@cisco.com>
(cherry picked from commit e5ff5a36dd126ee57dca4e0b03da2f7704e0a4f5)
Signed-off-by: Ole Troan <ot@cisco.com>

2 files changed, 6 insertions, 14 deletions

diff --git a/test/ext/vapi_c_test.c b/test/ext/vapi_c_test.c
index 0b22fff1706..d49f23023dd 100644
--- a/test/ext/vapi_c_test.c
+++ b/test/ext/vapi_c_test.c
@@ -359,14 +359,11 @@ show_version_cb (vapi_ctx_t ctx, void *caller_ctx,
 {
   ck_assert_int_eq (VAPI_OK, rv);
   ck_assert_int_eq (true, is_last);
-  ck_assert_str_eq ("vpe", (char *) vl_api_from_api_string (&p->program));
+  ck_assert_str_eq ("vpe", (char *) p->program);
   printf
     ("show_version_reply: program: `%s', version: `%s', build directory: "
-     "`%s', build date: `%s'\n",
-     vl_api_from_api_string (&p->program),
-     vl_api_from_api_string (&p->version),
-     vl_api_from_api_string (&p->build_directory),
-     vl_api_from_api_string (&p->build_date));
+     "`%s', build date: `%s'\n", p->program, p->version, p->build_directory,
+     p->build_date);
   ++*(int *) caller_ctx;
   return VAPI_OK;
 }
@@ -802,9 +799,7 @@ generic_cb (vapi_ctx_t ctx, void *callback_ctx, vapi_msg_id_t id, void *msg)
   ck_assert_int_eq (id, vapi_msg_id_show_version_reply);
   ck_assert_ptr_ne (NULL, msg);
   vapi_msg_show_version_reply *reply = msg;
-  ck_assert_str_eq ("vpe",
-		    (char *) vl_api_from_api_string (&reply->
-						     payload.program));
+  ck_assert_str_eq ("vpe", (char *) reply->payload.program);
   return VAPI_OK;
 }
 
diff --git a/test/ext/vapi_cpp_test.cpp b/test/ext/vapi_cpp_test.cpp
index 68366af2ac8..2c2a82c8a9d 100644
--- a/test/ext/vapi_cpp_test.cpp
+++ b/test/ext/vapi_cpp_test.cpp
@@ -49,11 +49,8 @@ void verify_show_version_reply (const Show_version_reply &r)
   auto &p = r.get_payload ();
   printf ("show_version_reply: program: `%s', version: `%s', build directory: "
           "`%s', build date: `%s'\n",
-          vl_api_from_api_string (&p.program),
-          vl_api_from_api_string (&p.version),
-          vl_api_from_api_string (&p.build_directory),
-          vl_api_from_api_string (&p.build_date));
-  ck_assert_str_eq ("vpe", (char *)vl_api_from_api_string (&p.program));
+          p.program, p.version, p.build_directory, p.build_date);
+  ck_assert_str_eq ("vpe", (char *)p.program);
 }
 
 Connection con;