LLDB

Tips on using LLDB

Transcript

1. LLDB Khoa Pham - 2359 Media
2. LLDB Home page http://lldb.llvm.org/ LLDB is an open-source debugger that features a REPL, along with C++ and Python plugins
3. Menu - Command - Use cases - Python - Chisel - Standalone
4. Command
5. Command - help Information on any command help print help thread continue help help
6. Command - print Print value print a print self
7. Command Prefix matching print, prin, pri, p expression, e Can’t use pr (print or process?)
8. Command $ variable Anything starting with a dollar sign is in LLDB’ s namespace and exists to help you print $0 + 7
9. Command - expression Evaluate an expression (ObjC++ or Swift) in the current program context, Modify values in the program expression $0 = 10 e $0 = 10
10. Command - print 'print' is an abbreviation for 'expression --'. Use -- to signify the end of the flags and the beginning of the input e --location -- -count
11. Command - print object See the description method of an object e -O -- aString po aString
12. Command - variable The variable must start with a dollar sign e NSInteger $b = 10; p $b + a
13. Command - flow Continue process continue, continue, c Step over thread step-over, next, n
14. Command - flow Step into thread step-in, step, s Step out thread step-out, finish
15. Command - thread return Executes the return command, jumping out of the current stack frame thread return YES
16. Breakpoint List breakpoints br li Create breakpoints br set -f ViewController.m 39
17. Use cases Find targets of a button po [self.myButton allTargets]
18. Use cases See the frame po self.view.frame e @import UIKit po self.view.frame
19. Use cases Change background color without continue e self.view.backgroundColor = [UIColor greenColor] e (void)[CATransaction flush]
20. Use cases Watch variable wivar self _number
21. Python LLDB has full, built-in Python support. If you type script in LLDB, it will open a Python REPL
22. .lldbinit Executed every time LLDB starts command script import /path/to/fblldb.py
23. Chisel brew update brew install chisel # ~/.lldbinit command script import /path/to/fblldb.py
24. Standalone Using LLDB as a Standalone Debugger
25. References - Getting Started with LLDB - Dancing in the Debugger — A Waltz with LLDB - Video Tutorial: Using LLDB in iOS - Navigating and discovering an iOS codebase using lldb - chisel