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Khoa Pham
August 27, 2015


Tips on using LLDB

Khoa Pham

August 27, 2015

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  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