mohitmishra786/low-level-dev-skills/lldb

lldb ./prog                         # load binary
lldb ./prog -- arg1 arg2            # with arguments
lldb -p 12345                       # attach to PID
lldb -c core.1234                   # load core dump
lldb ./prog core.1234               # binary + core

# By name
b main
breakpoint set --name foo
breakpoint set --name foo --condition 'x > 0'
 
# By file:line
b file.c:42
breakpoint set --file file.c --line 42
 
# By address
b -a 0x100003f20
 
# By regex
breakpoint set --func-regex '^MyClass::'
 
# List
breakpoint list / br l
 
# Delete
breakpoint delete 2
 
# Disable/enable
breakpoint disable 1
breakpoint enable 1
 
# Commands on hit
breakpoint command add 1
  > p x
  > continue
  > DONE

# Print variable
p x
frame variable x
p *ptr
p arr[0]
 
# Print expression
expression x * 2 + 1
expr (int)sqrt(9.0)
 
# All locals
frame variable
fr v -a          # include arguments
 
# Registers
register read
register read rip rsp
 
# Memory
memory read --size 4 --format x --count 10 0x7fff0000
x/10xw 0x7fff0000          # GDB-compatible syntax
 
# Type info
image lookup --type MyClass
type lookup MyClass

watchpoint set variable x           # write watchpoint
watchpoint set variable -w read x   # read watchpoint
watchpoint set variable -w read_write x
watchpoint set expression -- &x     # by address
 
watchpoint list
watchpoint delete 1

thread list
thread select 3
thread backtrace all
thread backtrace --count 5           # limit depth
 
# Per-thread stepping
thread step-over                     # step this thread only

# Symbol lookup in shared cache
image lookup --address 0x18ab12345
image lookup --name objc_msgSend
 
# Objective-C method breakpoint
b "-[NSArray objectAtIndex:]"
b "+[NSString stringWithFormat:]"
 
# Inspect Objective-C object
po myObject                          # print-object (calls -description)
po [arr count]
 
# Show loaded libraries
image list
image list -b                        # brief (names only)

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Debug (lldb)",
      "type": "lldb",
      "request": "launch",
      "program": "${workspaceFolder}/build/prog",
      "args": [],
      "cwd": "${workspaceFolder}",
      "preLaunchTask": "build"
    }
  ]
}

import lldb
def print_all_threads(debugger, command, result, internal_dict):
    target = debugger.GetSelectedTarget()
    process = target.GetProcess()
    for thread in process:
        print(f"Thread {thread.GetIndexID()}: {thread.GetName()}")
        for frame in thread:
            print(f"  {frame}")
def __lldb_init_module(debugger, internal_dict):
    debugger.HandleCommand('command script add -f myscript.print_all_threads pthreads')