dfilter: Add suport for raw addressing with references

Extends raw adressing syntax to wok with references. The syntax
is
    @field1 == ${@field2}

This requires replicating the logic to load field references, but
using raw values instead. We use separate hash tables for that,
namely "references" vs "raw_references".

1 files changed, 5 insertions, 0 deletions

diff --git a/test/suite_dfilter/group_syntax.py b/test/suite_dfilter/group_syntax.py
index c277ba97df..235c57468b 100644
--- a/test/suite_dfilter/group_syntax.py
+++ b/test/suite_dfilter/group_syntax.py
@@ -348,3 +348,8 @@ class case_raw_modifier(unittest.TestCase):
     def test_raw2(self, checkDFilterCount):
         dfilter = '@s7comm.blockinfo.blocktype == 30:fe'
         checkDFilterCount(dfilter, 1)
+
+    def test_raw_ref(self, checkDFilterCountWithSelectedFrame):
+        dfilter = '@s7comm.blockinfo.blocktype == ${@s7comm.blockinfo.blocktype}'
+        # select frame 3, expect 2 frames out of 3.
+        checkDFilterCountWithSelectedFrame(dfilter, 2, 3)