LLDB — evaluate and continue

Question

XCode has functionality to set breakpoint, then run lldb command and “Automatically continue after evaluating”.

How to setup same functionality via --source ? Found --command quote in the manual, but no examples and no reference in sub-command help

By default, the breakpoint command add command takes lldb command line commands. You can also specify this explicitly by passing the "--command" option.

Syntax: command <sub-command> [<sub-command-options>] <breakpoint-id>

Answer 1

I think you are asking about auto-continue with lldb?

I used the modify command to add auto-continue..

(lldb) b CCCryptorCreate
Breakpoint 1: where = libcommonCrypto.dylib`CCCryptorCreate, address = 0x000000011047e1b7

(lldb) breakpoint modify --auto-continue true 1
(lldb) br list
Current breakpoints:
1: name = 'CCCryptorCreate', locations = 1, resolved = 1, hit count = 0 Options: enabled auto-continue 
  1.1: where = libcommonCrypto.dylib`CCCryptorCreate, address = 0x000000011047e1b7, resolved, hit count = 0 

then to add some commands I used..

(lldb) breakpoint command add -s python 1
Enter your Python command(s). Type 'DONE' to end.
    print "Hit this breakpoint!"
    DONE

The help has some good examples (lldb) help breakpoint command add

Answer 2

help breakpoint command add reveals it is called --one-liner, --command must be a typo?

-o <one-line-command> ( --one-liner <one-line-command> )
     Specify a one-line breakpoint command inline.

Question is actual, how to automatically continue when --source is used

Answer 3

I'm not entirely clear what you are asking.

But if you want to put commands in a text file somewhere which will add set a breakpoint and add commands to it you want something like:

> cat /tmp/cmds.lldb
break set -F main
break command add
frame var
continue
DONE
> lldb -s /tmp/cmds.lldb myBinary

Or if you want to do this in Xcode, just use:

(lldb) command source /tmp/cmds.lldb

once you are in the Xcode debugging session.

This relies on one trick, the "breakpoint command add" command operates on the last breakpoint set, which was why I didn't have to specify the breakpoint number.