commit e5ff5a36dd126ee57dca4e0b03da2f7704e0a4f5
author Ole Troan <ot@cisco.com> Fri Aug 23 22:55:18 2019 +0200
committer Andrew Yourtchenko <ayourtch@gmail.com> Tue Sep 03 20:04:13 2019 +0000
tree 2108baa60e8a697624288fe2c3050be29697bc88
parent b6fde4a8bae474c6b73d08d223028f42e396d452

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>

src/vpp-api/vapi/vapi_c_gen.py

diff --git a/src/vpp-api/vapi/vapi_c_gen.py b/src/vpp-api/vapi/vapi_c_gen.py
index 381dcba..b9b9aa7 100755
--- a/src/vpp-api/vapi/vapi_c_gen.py
+++ b/src/vpp-api/vapi/vapi_c_gen.py
@@ -13,10 +13,16 @@
         return "vapi_type_%s" % self.name
 
     def get_c_def(self):
-        if self.len is not None:
-            return "%s %s[%d];" % (self.type.get_c_name(), self.name, self.len)
+        if self.type.get_c_name() == 'vl_api_string_t':
+            if self.len:
+                return "u8 %s[%d];" % (self.name, self.len)
+            else:
+                return "vl_api_string_t %s;" % (self.name)
         else:
-            return "%s %s;" % (self.type.get_c_name(), self.name)
+            if self.len is not None:
+                return "%s %s[%d];" % (self.type.get_c_name(), self.name, self.len)
+            else:
+                return "%s %s;" % (self.type.get_c_name(), self.name)
 
     def get_swap_to_be_code(self, struct, var):
         if self.len is not None:

src/vpp-api/vapi/vapi_json_parser.py

diff --git a/src/vpp-api/vapi/vapi_json_parser.py b/src/vpp-api/vapi/vapi_json_parser.py
index a9d2c81..d766936 100644
--- a/src/vpp-api/vapi/vapi_json_parser.py
+++ b/src/vpp-api/vapi/vapi_json_parser.py
@@ -177,12 +177,15 @@
                     p = field_class(field_name=field[1],
                                     field_type=field_type)
                 elif l == 3:
-                    if field[2] == 0:
+                    if field[2] == 0 and field[0] != 'string':
                         raise ParseError(
                             "While parsing message `%s': variable length "
                             "array `%s' doesn't have reference to member "
                             "containing the actual length" % (
                                 name, field[1]))
+                    if field[0] == 'string' and field[2] > 0:
+                        field_type = json_parser.lookup_type_like_id('u8')
+
                     p = field_class(
                         field_name=field[1],
                         field_type=field_type,