lldb/examples/python/shadow.py

   1 #!/usr/bin/env python
   2
   3 import lldb
   4 import shlex
   5
   6
   7 @lldb.command("shadow")
   8 def check_shadow_command(debugger, command, exe_ctx, result, dict):
   9     """Check the currently selected stack frame for shadowed variables"""
  10     process = exe_ctx.GetProcess()
  11     state = process.GetState()
  12     if state != lldb.eStateStopped:
  13         print(
  14             "process must be stopped, state is %s"
  15             % lldb.SBDebugger.StateAsCString(state),
  16             file=result,
  17         )
  18         return
  19     frame = exe_ctx.GetFrame()
  20     if not frame:
  21         print("invalid frame", file=result)
  22         return
  23     # Parse command line args
  24     command_args = shlex.split(command)
  25     # TODO: add support for using arguments that are passed to this command...
  26
  27     # Make a dictionary of variable name to "SBBlock and SBValue"
  28     shadow_dict = {}
  29
  30     num_shadowed_variables = 0
  31     # Get the deepest most block from the current frame
  32     block = frame.GetBlock()
  33     # Iterate through the block and all of its parents
  34     while block.IsValid():
  35         # Get block variables from the current block only
  36         block_vars = block.GetVariables(frame, True, True, True, 0)
  37         # Iterate through all variables in the current block
  38         for block_var in block_vars:
  39             # Since we can have multiple shadowed variables, we our variable
  40             # name dictionary to have an array or "block + variable" pairs so
  41             # We can correctly print out all shadowed variables and whow which
  42             # blocks they come from
  43             block_var_name = block_var.GetName()
  44             if block_var_name in shadow_dict:
  45                 shadow_dict[block_var_name].append(block_var)
  46             else:
  47                 shadow_dict[block_var_name] = [block_var]
  48         # Get the parent block and continue
  49         block = block.GetParent()
  50
  51     num_shadowed_variables = 0
  52     if shadow_dict:
  53         for name in shadow_dict.keys():
  54             shadow_vars = shadow_dict[name]
  55             if len(shadow_vars) > 1:
  56                 print('"%s" is shadowed by the following declarations:' % (name))
  57                 num_shadowed_variables += 1
  58                 for shadow_var in shadow_vars:
  59                     print(str(shadow_var.GetDeclaration()), file=result)
  60     if num_shadowed_variables == 0:
  61         print("no variables are shadowed", file=result)