[LLDB] Create your own command in Python

Load the original command created in Python into LLDB of Xcode.

Xcode seems to read one of the following two at startup.

• ~/.lldbinit
• ~/.lldbinit-Xcode

Basically it seems that .lldbinit-Xcode is loaded. However, since the above is read from the command line etc., if you describe the basic settings in .lldbinit and put the process to read .lldbinit in .lldbinit-Xcode as follows It's okay.

command source ~/.lldbinit

Read the original command file at startup

After setting as above, the command will be loaded automatically by setting to read the Python file in .lldbinit.

command script import ~/.lldb/hoge.py

Define in file

After setting the reading settings described above, define the contents to be actually read. The main format and required description are as follows.

new-command.py

#!/usr/bin/env python
#coding: utf-8

import lldb
import commands
import os

def command_function(debugger, command, result, internal_dict):
	cmd = "po self"
	debugger.HandleCommand(cmd)
	
def __lldb_init_module(debugger, internal_dict):
	debugger.HandleCommand("command script add -f new-command:command_function commandname")
	print "commandname has been installed."

After defining it, read it as follows.

(lldb) command script import /path/to/command.py

Set inline during break

It is easy to check the operation by setting it inline and executing it for a little operation test.

The following will start the python interpreter.

(lldb) script⏎

Then define as follows and exit the interpreter.

(lldb) script⏎
Python Interactive Interpreter. To exit, type 'quit()', 'exit()' or Ctrl-D.
>>> def hoge_function(debugger, command, result, internal_dict):
...	cmd = "po self"
...	debugger.HandleCommand(cmd)
...	
>>> quit⏎
(lldb) command script add hoge -f hoge_func
(lldb) hoge
<UIView...

String placeholder

You can use the placeholder by writing as follows. This is convenient when processing is performed based on the character string specified in the command.

val = "This is %s %s" % ("a", "pen")

# --- or ---

val = "This is %(unit)s %(msg)s" % {"unit": "a", "msg": "pen"}

# --- or ---

val = """This is
%s %s""" % ("a", "pen")

Split command

The command is passed as a single string, so use shlex.split to split it.

command_list = shlex.split(command)

Command to copy dummy view and ʻadd Subview:`

What I wanted to do this time was to create a command that duplicates the view using the specified view size and ʻadd Subview: `to see if the view is properly generated at the desired position. ..

I think it's a bit redundant, but for the time being, it worked if I did the following, so I'll describe it.

#!/usr/bin/env python
# -*- coding: utf-8

import lldb
import commands
import os
import shlex

def dmy_func(debugger, command, result, internal_dict):
    commands = shlex.split(command)

    count = len(commands)

    if count < 2:
        return

    cmd = "po CGRect $frame = (CGRect)[%s frame]" % commands[0]
    print(cmd)
    debugger.HandleCommand(cmd)

    cmd = "po UIView *$view = [[UIView alloc] initWithFrame:(CGRect)$frame]"
    print(cmd)
    debugger.HandleCommand(cmd)

    cmd = "po [$view setBackgroundColor:(UIColor*)[UIColor redColor]]"
    print(cmd)
    debugger.HandleCommand(cmd)

    cmd = "po [%s addSubview:(UIView*)$view]" % commands[1]
    print(cmd)
    debugger.HandleCommand(cmd)

def __lldb_init_module(debugger, internal_dict):
    debugger.HandleCommand("command script add -f dmy.dmy_func dmy")
    print "dmy command has been installed."

How to use

(lldb) dmy self.hogeView self.view

Create a UIView using the frame of self.hogeView and ʻaddSubview:toself.view`.