fhdl/namer: extract variable names with bytecode inspection

diff --git a/migen/fhdl/namer.py b/migen/fhdl/namer.py
index 39d488459fd8e365d75616a797c669aa70564ef1..530eedcc1af927001a7b4bec2d211b91ddf51dba 100644 (file)
--- a/migen/fhdl/namer.py
+++ b/migen/fhdl/namer.py
@@ -1,6 +1,27 @@
 import inspect
-import re
 from itertools import combinations
+from opcode import opname
+
+def get_var_name(frame):
+       code = frame.f_code
+       call_index = frame.f_lasti
+       if opname[code.co_code[call_index]] != "CALL_FUNCTION":
+               return None
+       index = call_index+3
+       while True:
+               opc = opname[code.co_code[index]]
+               if opc == "STORE_NAME" or opc == "STORE_ATTR":
+                       name_index = int(code.co_code[index+1])
+                       return code.co_names[name_index]
+               elif opc == "STORE_FAST":
+                       name_index = int(code.co_code[index+1])
+                       return code.co_varnames[name_index]
+               elif opc == "LOAD_GLOBAL" or opc == "LOAD_ATTR" or opc == "LOAD_FAST":
+                       index += 3
+               elif opc == "DUP_TOP":
+                       index += 1
+               else:
+                       return None
 
 def trace_back(name=None):
        l = []
@@ -16,13 +37,7 @@ def trace_back(name=None):
                        obj = modules[len(modules)-1]
                
                if name is None:
-                       code_contexts = inspect.getframeinfo(frame).code_context
-                       if code_contexts is not None:
-                               line = code_contexts[0]
-                               m = re.match("[\t ]*([0-9A-Za-z_\.]+)[\t ]*=", line)
-                               if m is not None:
-                                       names = m.group(1).split(".")
-                                       name = names[len(names)-1]
+                       name = get_var_name(frame)
                l.insert(0, (obj, name))
                name = None
                frame = frame.f_back