LLDB Python/C++ 绑定：异步步骤指令

Question

我正在尝试单步执行线程。这在我使用 debugger.SetAsync(False) 时有效，但我想异步执行此操作。这是一个重现它的脚本。它在设置 debugger.SetAsync (False) 而不是 True 时执行。我添加了 time.sleep 以便它有时间执行我的指令。我期待 frame.pc

中的下一条指令

import time
import sys
lldb_path = "/Applications/Xcode.app/Contents/SharedFrameworks/LLDB.framework/Resources/Python"
sys.path = sys.path + [lldb_path]

import lldb
import os
exe = "./a.out"    
debugger = lldb.SBDebugger.Create()

debugger.SetAsync (True) # change this to False, to make it work


target = debugger.CreateTargetWithFileAndArch (exe, lldb.LLDB_ARCH_DEFAULT)

if target:
    main_bp = target.BreakpointCreateByName ("main", target.GetExecutable().GetFilename()) 
    print main_bp

    launch_info = lldb.SBLaunchInfo(None)
    launch_info.SetExecutableFile (lldb.SBFileSpec(exe), True)
    error = lldb.SBError()
    process = target.Launch (launch_info, error)
    time.sleep(1)
    # Make sure the launch went ok
    if process:
        # Print some simple process info
        state = process.GetState ()
        print 'process state'
        print state
        thread = process.GetThreadAtIndex(0)
        frame = thread.GetFrameAtIndex(0)
        print 'stop loc'
        print hex(frame.pc)
        print 'thread stop reason'
        print thread.stop_reason

        print 'stepping'
        thread.StepInstruction(False)

        time.sleep(1)

        print 'process state'
        print process.GetState ()

        print 'thread stop reason'
        print thread.stop_reason
        frame = thread.GetFrameAtIndex(0)
        print 'stop loc'
        print hex(frame.pc)  # invalid output?

版本：lldb-340.4.110（提供Xcode）
Python: Python 2.7.10
Os: Mac Yosemite

Answer 1

lldb API 的“异步”版本使用基于事件的系统。您不能使用 sleep 等待事情发生——而是使用 WaitForEvent API 的 lldb 提供。有关如何执行此操作的示例，请参见：

https://github.com/llvm/llvm-project/blob/main/lldb/examples/python/process_events.py

示例开头有一堆内容，展示了如何加载 lldb 模块并进行参数解析。您要查看的部分是循环：

        listener = debugger.GetListener()
        # sign up for process state change events
        stop_idx = 0
        done = False
        while not done:
            event = lldb.SBEvent()
            if listener.WaitForEvent (options.event_timeout, event):

及以下。

LLDB Python/C++ 绑定：异步步骤指令

LLDB Python/C++ bindings: Async Step instructions

python

lldb