The LLDB Debugger

# Mac OS X Status

LLDB has matured a lot in the last year and can be used for C, C++ and Objective C development for x86_64, i386 and ARM debugging. The entire public API is exposed though a framework on Mac OS X which is used by Xcode, the lldb command line tool, and can also be used by Python. The entire public API is exposed through script bridging which allows LLDB to use an embedded Python script interpreter, as well as having a Python module named "lldb" which can be used from Python on the command line. This allows debug sessions to be scripted. It also allows powerful debugging actions to be created and attached to a variety of debugging workflows.

# Linux Status

LLDB is improving on Linux. While the debugserver has not been ported (to enable remote debugging) Linux is nearing feature completeness with Darwin to debug x86_64 programs, and is partially working with i386 programs. ARM architectures on Linux are untested. For more details, see the Features by OS section below.

# FreeBSD Status

LLDB on FreeBSD lags behind the Linux implementation but is improving rapidly. For more details, see the Features by OS section below.

# Features by OS

The table below shows a summary of the features that are available on several platforms. In addition to Linux and Mac OS X, LLDB is also known to work on FreeBSD. Windows support is under development.

Feature | FreeBSD (x86_64) | Linux (x86_64) | Mac OS X (i386/x86_64 and ARM/Thumb)
--- | --- | --- | ---
Backtracing | OK | OK | OK

Breakpoints

- source-line
- symbolic
- C++ mangled names
- module scoping

OK

OK

OK

C++11:

- function access
- template support
- dynamic types

OK

OK

OK

Commandline lldb tool | OK | OK | OK
Core file debugging | OK (ELF) | OK (ELF) | OK (MachO)
Debugserver (remote debugging) | Not ported | Not ported | OK
Disassembly | OK | OK | OK
Expression evaluation | Unknown | Works with some bugs | OK
JIT debugging | Unknown | Symbolic debugging only | Untested

Objective-C 2.0:

- printing properties
- synthetic properties
- expressions
- KVO
- dynamic types
- dot syntax
- runtime data
- stepping into/over
- printing the description of an object ("po")

Unknown

Not applicable

OK

Process control

- attach
- continue
- exec, execve...
- fork
- launch
- status

Works, with some bugs

OK (except exec*)

OK

Public Python API | OK | OK | OK

Registers (x86_64 and i386)

- general purpose
- floating point
- exception state
- SSE
- AVX

GP and FP OK

OK (except for exception state registers)

OK

Script bridging | OK | OK | OK
Symbol reading and object file introspection | OK | OK | OK
Thread inspection and stepping | OK | OK | OK
Watchpoints | OK | OK | OK