LLDB

LLDB.md

Explore variables value and state

expression, e, print, p, po

(lldb) print ... = (lldb) p ... = (lldb) expression -- ... = (lldb) e -- ...

Evaluate an expression on the current thread. Display any returned value with LLDB defalt formating.

1. Usage

• (lldb) e
• (lldb) expression

2. Flags

• -D (--depth ) — Set the max recurse depth when dumping aggregate types (default is infinity).
• -O (--object-description) — Display using a language-specific description API, if possible.
• -T (--show-types) — Show variable types when dumping values.
• -f (--format ) –– Specify a format to be used for display.
• -i (--ignore-breakpoints ) — Ignore breakpoint hits while running expressions

3. Help

  - (lldb) help # To explore all available commands
  - (lldb) help expression # To explore all expressions related sub-commands

4. Example

• (lldb) e -D 1 -- self
• (lldb) e -D 1 -i false -- someMethod()

Get overall app’s state + language specific commands

1. bugreport

• Report full current app's state

2. frame

• Quick overview stack frame in current thread.

Control app's Execution follow

process, breakpoint, thread

• process: control debug process

  The following subcommands are supported:

    attach    -- Attach to a process.
    connect   -- Connect to a remote debug service.
    continue  -- Continue execution of all threads in the current process.
    detach    -- Detach from the current target process.
    handle    -- Manage LLDB handling of OS signals for the current target
                 process.  Defaults to showing current policy.
    interrupt -- Interrupt the current target process.
    kill      -- Terminate the current target process.
    launch    -- Launch the executable in the debugger.
    load      -- Load a shared library into the current process.
    plugin    -- Send a custom command to the current target process plug-in.
    save-core -- Save the current process as a core file using an appropriate
                 file type.
    signal    -- Send a UNIX signal to the current target process.
    status    -- Show status and stop location for the current target process.
    unload    -- Unload a shared library from the current process using the
                 index returned by a previous call to "process load".

• breakpoint

- breakpoint list
- breakpoint set -f ViewController.swift -l 96
- b ViewController.swift:96 // Short version of the command above
- breakpoint set --func-regex valueOfLifeWithoutSumOf
- b -r valueOfLifeWithoutSumOf // Short version of the command above
- breakpoint set --one-shot -f ViewController.swift -l 90
- br s -o -f ViewController.swift -l 91 // Shorter version of the command above
- breakpoint command list 2

• thread

- (lldb) thread step-over
- (lldb) next // The same as "thread step-over" command
- (lldb) n // The same as "next" command
- (lldb) thread step-in
- (lldb) step // The same as "thread step-in"
- (lldb) s // The same as "step"

Honorable mentions

command, platform, gui

• command import ~/Desktop/script.py

import lldb

def print_hello(debugger, command, result, internal_dict):
  print "Hello Debugger!"

def __lldb_init_module(debugger, internal_dict):
  debugger.HandleCommand('command script add -f script.print_hello print_hello') // Handle script initialization and add command from this module
  print 'The "print_hello" python command has been installed and is ready for use.' // Print confirmation that everything works

• platform status
• gui