iOS_SN_LLDB常用命令

有一次因为封装一个控件，UI能正常显示就是不能点击，一点击就崩溃，而且异常断点也无法捕捉，把Xcode的僵尸对象打开，每次崩溃就打印一个地址，最后就必须根据地址寻找对象，可以使用frame variable命令检查帧参数和本地变量。当时用此命令打印出self的地址和崩溃地址一样，一下就缩小了检查范围，最后是因为按钮添加方法时target的参数把自己当做属性传过去了，其实只要把它自己传过去就行。

现在就说一说常用命令：

p 用于输出基本类型,

po 用于输出 Objective-C 对象,

print  与p命令相似   他们的具体打印信息如下：

(lldb) print mouthLable
(UILabel *) $3 = 0x09c77070
(lldb) p mouthLable
(UILabel *) $4 = 0x09c77070
(lldb) po mouthLable
<UILabel: 0x9c77070; frame = (0 0; 50 40); userInteractionEnabled = NO; layer = <_UILabelLayer: 0x52eec90>>

　　

上图显示了在控制台的左边有一个可以直接选择打印的对象，打印出来的结果如下：

Printing description of mouthLable:
<UILabel: 0x9c77070; frame = (0 0; 50 40); userInteractionEnabled = NO; layer = <_UILabelLayer: 0x52eec90>>

　　这些都是常用的输出方法，如果用这些输出方法输出带有宏定义的则输出不了，必须把宏定义的内容还原才行,用PO还可以输出方法，可以使输出的值强转。如下：

(lldb) po bigLable
<UILabel: 0xb3bcf70; frame = (0 0; 100 40); userInteractionEnabled = NO; layer = <_UILabelLayer: 0xb3bd050>>

(lldb) po [bigLable subviews]
<__NSArrayM 0xb3bf710>(
<UILabel: 0xb3beaa0; frame = (0 0; 50 40); text = '03月'; userInteractionEnabled = NO; layer = <_UILabelLayer: 0xb3acc90>>
)

(lldb) po (int)[[bigLable subviews] count]
1

(lldb)

　　线程状态

thread list：显示线程数

(lldb) thread list
Process 4198 stopped
* thread #1: tid = 0xfc64c, 0x00800b42 iSchool`-[YXHomeTViewController viewDidLoad](self=0x0b3b92d0, _cmd="viewDidLoad") + 1686 at YXHomeTViewController.m:138, queue = 'com.apple.main-thread', stop reason = breakpoint 5.1
  thread #5: tid = 0xfc690, 0x37d70224 libsystem_kernel.dylib`kevent64 + 24, queue = 'com.apple.libdispatch-manager'
  thread #6: tid = 0xfc694, 0x37d84190 libsystem_kernel.dylib`__semwait_signal + 24, name = 'gputools.smt_poll.0x22485c0'
  thread #11: tid = 0xfc6c7, 0x37d70474 libsystem_kernel.dylib`mach_msg_trap + 20, name = 'AFNetworking'
  thread #12: tid = 0xfc6cd, 0x37d70474 libsystem_kernel.dylib`mach_msg_trap + 20, name = 'com.apple.NSURLConnectionLoader'
  thread #15: tid = 0xfc6d0, 0x37d84080 libsystem_kernel.dylib`__select + 20, name = 'com.apple.CFSocket.private'
  thread #30: tid = 0xfc777, 0x37d70474 libsystem_kernel.dylib`mach_msg_trap + 20, name = 'EMGCDAsyncSocket-CFStream'
  thread #46: tid = 0xfdaf8, 0x37d849c0 libsystem_kernel.dylib`__workq_kernreturn + 8

　　星号(*)表示thread #1为当前线程。为了获取线程的跟踪栈，可以使用以下命令：

(lldb) thread backtrace
* thread #1: tid = 0xfc64c, 0x00800b42 iSchool`-[YXHomeTViewController viewDidLoad](self=0x0b3b92d0, _cmd="viewDidLoad") + 1686 at YXHomeTViewController.m:138, queue = 'com.apple.main-thread', stop reason = breakpoint 5.1
    frame #0: 0x00800b42 iSchool`-[YXHomeTViewController viewDidLoad](self=0x0b3b92d0, _cmd="viewDidLoad") + 1686 at YXHomeTViewController.m:138
    frame #1: 0x2c6c59ae UIKit`-[UIViewController loadViewIfRequired] + 602
    frame #2: 0x2c6c571c UIKit`-[UIViewController view] + 24
  * frame #3: 0x000dc80a iSchool`-[BaseViewControllerT showLoading](self=0x0b3b92d0, _cmd="showLoading") + 38 at BaseViewControllerT.m:72
    frame #4: 0x007ff70c iSchool`-[YXHomeTViewController TestHttp](self=0x0b3b92d0, _cmd="TestHttp") + 60 at YXHomeTViewController.m:56
    frame #5: 0x007ff6b4 iSchool`-[YXHomeTViewController init](self=0x0b3b92d0, _cmd="init") + 128 at YXHomeTViewController.m:49
    frame #6: 0x00747b36 iSchool`-[MobileCampusController didselCellZhengshi:](self=0x022e7fd0, _cmd="didselCellZhengshi:", indexPath=0x09ca75b0) + 1014 at MobileCampusController.m:304

　　如果要查看所有线程调用栈则可以使用

thread backtrace all

检查帧参数和本地变量的最简便的方式是使用frame variable命令

(lldb) frame variable
(YXHomeTViewController *) self = 0x0b3b92d0
(SEL) _cmd = "showLoading"

　　可以查看相关对象和地址。

image list可以用它来查看工程中使用的库。

(lldb) image list
[  0] B4BF0C10-3B1A-3FE5-9CCB-E65743E82B77 0x00004000 /Users/traceboard/Library/Developer/Xcode/DerivedData/iSchool-fujsfonczhafjxcmkgfofjbzpfwk/Build/Products/Debug-iphoneos/iSchool.app/iSchool
      /Users/traceboard/Library/Developer/Xcode/DerivedData/iSchool-fujsfonczhafjxcmkgfofjbzpfwk/Build/Products/Debug-iphoneos/iSchool.app.dSYM/Contents/Resources/DWARF/iSchool
[  1] 6CF411B5-99E9-3791-B3F4-0CED325786DD 0x1fe0b000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/usr/lib/dyld
[  2] 8574AF16-8793-3D1C-AEE7-FC2A51F04E4F 0x371ad000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/usr/lib/libicucore.A.dylib
[  3] 2E1A648A-1C0A-3A65-9BAF-221C2719C5C4 0x28d04000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/System/Library/Frameworks/CoreBluetooth.framework/CoreBluetooth
[  4] E9633AB3-EDDC-3032-8604-7203C343F2B8 0x296ff000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/System/Library/Frameworks/CoreLocation.framework/CoreLocation
[  5] 92F64E66-D354-3D04-BAED-AE41A6291C31 0x37a17000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/usr/lib/libsqlite3.dylib
[  6] 65E6D41B-25C1-306E-BE96-DF64D33C03AB 0x37c22000 /Users/traceboard/Library/Developer/Xcode/iOS DeviceSupport/8.4.1 (12H321)/Symbols/usr/lib/libz.1.dylib

　　

还有可以设置断点：breakpoint set等命令，因为设置断点可以用图形界面更快更直观的设置，还有可以设置程序运行的步骤thread step等命令，都可以使用图形界面进行控制，而用的不多，个人感觉最有用的要属寻找对象地址，打印对象信息。