nmigen/tracer.py

   1 import inspect
   2 from opcode import opname
   3
   4
   5 class NameNotFound(Exception):
   6     pass
   7
   8
   9 def get_var_name(depth=2):
  10     frame = inspect.currentframe()
  11     for _ in range(depth):
  12         frame = frame.f_back
  13
  14     code = frame.f_code
  15     call_index = frame.f_lasti
  16     call_opc   = opname[code.co_code[call_index]]
  17     if call_opc not in ("CALL_FUNCTION", "CALL_FUNCTION_KW", "CALL_FUNCTION_EX", "CALL_METHOD"):
  18         return None
  19
  20     index = call_index + 2
  21     while True:
  22         opc = opname[code.co_code[index]]
  23         if opc in ("STORE_NAME", "STORE_ATTR"):
  24             name_index = int(code.co_code[index + 1])
  25             return code.co_names[name_index]
  26         elif opc == "STORE_FAST":
  27             name_index = int(code.co_code[index + 1])
  28             return code.co_varnames[name_index]
  29         elif opc == "STORE_DEREF":
  30             name_index = int(code.co_code[index + 1])
  31             return code.co_cellvars[name_index]
  32         elif opc in ("LOAD_GLOBAL", "LOAD_ATTR", "LOAD_FAST", "LOAD_DEREF",
  33                      "DUP_TOP", "BUILD_LIST"):
  34             index += 2
  35         else:
  36             raise NameNotFound