litex/gen/migen/fhdl/tracer.py

   1 import inspect
   2 from opcode import opname
   3 from collections import defaultdict
   4
   5
   6 def get_var_name(frame):
   7     code = frame.f_code
   8     call_index = frame.f_lasti
   9     call_opc = opname[code.co_code[call_index]]
  10     if call_opc != "CALL_FUNCTION" and call_opc != "CALL_FUNCTION_VAR":
  11         return None
  12     index = call_index+3
  13     while True:
  14         opc = opname[code.co_code[index]]
  15         if opc == "STORE_NAME" or opc == "STORE_ATTR":
  16             name_index = int(code.co_code[index+1])
  17             return code.co_names[name_index]
  18         elif opc == "STORE_FAST":
  19             name_index = int(code.co_code[index+1])
  20             return code.co_varnames[name_index]
  21         elif opc == "STORE_DEREF":
  22             name_index = int(code.co_code[index+1])
  23             return code.co_cellvars[name_index]
  24         elif opc == "LOAD_GLOBAL" or opc == "LOAD_ATTR" or opc == "LOAD_FAST" or opc == "LOAD_DEREF":
  25             index += 3
  26         elif opc == "DUP_TOP":
  27             index += 1
  28         elif opc == "BUILD_LIST":
  29             index += 3
  30         else:
  31             return None
  32
  33
  34 def remove_underscore(s):
  35     if len(s) > 2 and s[0] == "_" and s[1] != "_":
  36         s = s[1:]
  37     return s
  38
  39
  40 def get_obj_var_name(override=None, default=None):
  41     if override:
  42         return override
  43
  44     frame = inspect.currentframe().f_back
  45     # We can be called via derived classes. Go back the stack frames
  46     # until we reach the first class that does not inherit from us.
  47     ourclass = frame.f_locals["self"].__class__
  48     while "self" in frame.f_locals and isinstance(frame.f_locals["self"], ourclass):
  49         frame = frame.f_back
  50
  51     vn = get_var_name(frame)
  52     if vn is None:
  53         vn = default
  54     else:
  55         vn = remove_underscore(vn)
  56     return vn
  57
  58 name_to_idx = defaultdict(int)
  59 classname_to_objs = dict()
  60
  61
  62 def index_id(l, obj):
  63     for n, e in enumerate(l):
  64         if id(e) == id(obj):
  65             return n
  66     raise ValueError
  67
  68
  69 def trace_back(varname=None):
  70     l = []
  71     frame = inspect.currentframe().f_back.f_back
  72     while frame is not None:
  73         if varname is None:
  74             varname = get_var_name(frame)
  75         if varname is not None:
  76             varname = remove_underscore(varname)
  77             l.insert(0, (varname, name_to_idx[varname]))
  78             name_to_idx[varname] += 1
  79
  80         try:
  81             obj = frame.f_locals["self"]
  82         except KeyError:
  83             obj = None
  84         if hasattr(obj, "__del__"):
  85             obj = None
  86
  87         if obj is None:
  88             if varname is not None:
  89                 coname = frame.f_code.co_name
  90                 if coname == "<module>":
  91                     modules = frame.f_globals["__name__"]
  92                     modules = modules.split(".")
  93                     coname = modules[len(modules)-1]
  94                 coname = remove_underscore(coname)
  95                 l.insert(0, (coname, name_to_idx[coname]))
  96                 name_to_idx[coname] += 1
  97         else:
  98             classname = obj.__class__.__name__.lower()
  99             try:
 100                 objs = classname_to_objs[classname]
 101             except KeyError:
 102                 classname_to_objs[classname] = [obj]
 103                 idx = 0
 104             else:
 105                 try:
 106                     idx = index_id(objs, obj)
 107                 except ValueError:
 108                     idx = len(objs)
 109                     objs.append(obj)
 110             classname = remove_underscore(classname)
 111             l.insert(0, (classname, idx))
 112
 113         varname = None
 114         frame = frame.f_back
 115     return l