general: add support for declaring enums as struct members

the enum types are resolved to the wiretypes for the benefit of c-loxi.

loxi_utils/loxi_utils.py

@@ -36,6 +36,7 @@
 import sys
 import of_g
 import tenjin
+from generic_utils import find, memoize
 
 def class_signature(members):
     """
@@ -517,6 +518,17 @@ def render_static(out, name, path):
     with open(template_filename) as infile:
         out.write(infile.read())
 
+@memoize
+def lookup_ir_wiretype(oftype, version):
+    """ if of is a reference to an enum in ir, resolve it to the wiretype
+        declared in that enum. Else return oftype """
+    enums = of_g.ir[version].enums
+    enum = find(lambda e: e.name == oftype, enums)
+    if enum and 'wire_type' in enum.params:
+        return enum.params['wire_type']
+    else:
+        return oftype
+
 class TemplateEngine(tenjin.Engine):
     def include(self, template_name, **kwargs):
         """

loxigen.py

@@ -442,7 +442,11 @@ def read_input():
                         if m.oftype == 'of_oxm_t':
                             m_type = 'of_octets_t'
                         else:
-                            m_type = m.oftype
+                            enum = find(lambda e: e.name == m.oftype, ofinput.enums)
+                            if enum and "wire_type" in enum.params:
+                                m_type = enum.params["wire_type"]
+                            else:
+                                m_type = m.oftype
                         legacy_members.append(dict(m_type=m_type, name=m.name))
                 versions[version_name]['classes'][ofclass.name] = legacy_members