table.lua: Add support for decoding bitfield types

src/lua/bcc/table.lua

@@ -273,25 +273,31 @@ local function _decode_table_type(desc)
  return t
  end
 
- local fields = ""
+ local fields = {}
  local struct = t[3] or "struct"
 
  for _, value in ipairs(t[2]) do
+ local f = nil
+
  if #value == 2 then
- fields = fields .. string.format("%s %s; ", _dec(value[2]), value[1])
+ f = string.format("%s %s;", _dec(value[2]), value[1])
  elseif #value == 3 then
  if type(value[3]) == "table" then
- fields = fields .. string.format("%s %s[%d]; ", _dec(value[2]), value[1], value[3][1])
- else
- error("not implemented: "..json_desc)
+ f = string.format("%s %s[%d];", _dec(value[2]), value[1], value[3][1])
+ elseif type(value[3]) == "number" then
+ local t = _dec(value[2])
+ assert(t == "int" or t == "unsigned int",
+ "bitfields can only appear in [unsigned] int types")
+ f = string.format("%s %s:%d;", t, value[1], value[3])
  end
- else
- error("failed to decode type "..json_desc)
  end
+
+ assert(f ~= nil, "failed to decode type "..json_desc)
+ table.insert(fields, f)
  end
 
  assert(struct == "struct" or struct == "union", "unknown complex type: "..struct)
- return string.format("%s { %s}", struct, fields)
+ return string.format("%s { %s }", struct, table.concat(fields, " "))
  end
  return _dec(json.parse(json_desc))
 end