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