LLDB 常用命令

版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/u011374318/article/details/79648178

LLDB 小结

简介

LLDB 是新一代高性能调试器,其是一组可重用组件的集合,这些组件大多是 LLVM 工程中的类库,如 Clang 表达式解析器或 LLVM 反汇编程序等。LLDB 是 Xcode 中默认的调试器,并且支持调试 C/C++ 程序,详情参考官方文档

LLDB 命令

LLDB 的命令格式不同于 GDB 的命令格式的随意,而是统一为如下格式:

<命令名称> <命令动作> [-可选项 [可选项的值]] [参数1 [参数2···]]

需要注意的是,不管是命令名称、命令动作、可选项还是参数,它们都是由空格分隔的,所以如果,参数本身包含由空格符号,那么,使用双引号来包裹参数,如果,参数中包含有反斜杠或双引号,那么使用反斜杠对它们进行转义。

多个可选项在命令行中的顺序并不是固定的,但是如果可选项后的参数是以 - 开始的,那么需要使用 -- 标记可选项的结束,如下面的命令:

(lldb) process launch --stop-at-entry -- -program_arg_1 value -program_arg_2 value

//可选项顺序可以不固定
(lldb) breakpoint set -l 34 -f UIView+Theme.m
(lldb) breakpoint set -f UIView+Theme.m -l 35

开启调试

打开命令行,使用如下命令:

Martin-mini:Applications hanxuejian$ lldb zoom.us.app/
(lldb) target create "zoom.us.app/"
Current executable set to 'zoom.us.app/' (i386).

或者

Martin-mini:Applications hanxuejian$ lldb
(lldb) file zoom.us.app/
Current executable set to 'zoom.us.app/' (i386).
(lldb) quit
Martin-mini:Applications hanxuejian$ 

或者使用 Xcode 进入调试模式。

结束调试

(lldb) quit

设置命令别名

对于常用的命令,可以设置别名,使其简单化,如:

(lldb) breakpoint set --file foo.c --line 12

(lldb) command alias bfl breakpoint set -f %1 -l %2 
(lldb) bfl foo.c 12

取消命令的别名

(lldb) command unalias b
(lldb) command alias b breakpoint

设置断点

  1. 指定文件及代码行

    (lldb) breakpoint set --file foo.c --line 12 
    (lldb) breakpoint set -f foo.c -l 12
  2. 指定函数名称

    (lldb) breakpoint set --name foo 
    (lldb) breakpoint set -n foo
    (lldb) breakpoint set --name foo --name bar
  3. 指定方法名称

    (lldb) breakpoint set --method foo 
    (lldb) breakpoint set -M foo
  4. 指定 OC 选择器

    (lldb) breakpoint set --selector alignLeftEdges: 
    (lldb) breakpoint set -S alignLeftEdges:
  5. 指定映像文件

    (lldb) breakpoint set --shlib foo.dylib --name foo 
    (lldb) breakpoint set -s foo.dylib -n foo
    
    //--shlib 可以重复使用
    (lldb) breakpoint set --shlib foo.dylib --name foo --shlib foo1.dylib --name foo1

编辑断点

  1. 查看设置的断点

    (lldb) breakpoint list

    如下面的例子:

    (lldb) breakpoint set -M load
    Breakpoint 12: 25 locations.
    (lldb) breakpoint list
    Current breakpoints:
    12: name = 'load', locations = 25, resolved = 25, hit count = 0
      12.1: where = MobileCoreServices`_LSPreferences::load(), address = 0x00000001072bc684, resolved, hit count = 0 
      12.2: where = libicucore.A.dylib`icu::CollationRoot::load(UErrorCode&), address = 0x00000001074eef18, resolved, hit count = 0 
      12.3: where = libicucore.A.dylib`icu::VTimeZone::load(icu::VTZReader&, UErrorCode&), address = 0x00000001075c2b34, resolved, hit count = 0 
      12.4: where = WebCore`WebCore::CachedFont::load(WebCore::CachedResourceLoader&, WebCore::ResourceLoaderOptions const&), address = 0x000000010aa16a20, resolved, hit count = 0 
      12.5: where = WebCore`WebCore::CachedImage::load(WebCore::CachedResourceLoader&, WebCore::ResourceLoaderOptions const&), address = 0x000000010aa18170, resolved, hit count = 0 
      12.6: where = WebCore`WebCore::CachedResource::load(WebCore::CachedResourceLoader&, WebCore::ResourceLoaderOptions const&), address = 0x000000010aa1dc40, resolved, hit count = 0 
      12.7: where = WebCore`WebCore::CachedSVGDocumentReference::load(WebCore::CachedResourceLoader&, WebCore::ResourceLoaderOptions const&), address = 0x000000010aa2ad20, resolved, hit count = 0 
      12.8: where = WebCore`WebCore::CSSFontFace::load(), address = 0x000000010aafab20, resolved, hit count = 0 
      12.9: where = WebCore`WebCore::CSSFontFaceSource::load(WebCore::CSSFontSelector&), address = 0x000000010ab028a0, resolved, hit count = 0 
      12.10: where = WebCore`WebCore::FontFace::load(), address = 0x000000010ad5a2a0, resolved, hit count = 0 
      12.11: where = WebCore`WebCore::FontFaceSet::load(WTF::String const&, WTF::String const&, WebCore::DOMPromise<WTF::Vector<WTF::RefPtr<WebCore::FontFace>, 0ul, WTF::CrashOnOverflow, 16ul> >&&), address = 0x000000010ad5ad60, resolved, hit count = 0 
      12.12: where = WebCore`WebCore::FrameLoader::load(WebCore::DocumentLoader*), address = 0x000000010ad9fc70, resolved, hit count = 0 
      12.13: where = WebCore`WebCore::HRTFDatabaseLoader::load(), address = 0x000000010ae22e20, resolved, hit count = 0 
      12.14: where = WebCore`WebCore::HTMLMediaElement::load(), address = 0x000000010ae7e7f0, resolved, hit count = 0 
      12.15: where = WebCore`WebCore::JSFontFace::load(JSC::ExecState&), address = 0x000000010b1017f0, resolved, hit count = 0 
      12.16: where = WebCore`WebCore::MediaPlayer::load(WebCore::URL const&, WebCore::ContentType const&, WTF::String const&), address = 0x000000010b3d3ad0, resolved, hit count = 0 
      12.17: where = WebCore`WebCore::NullMediaPlayerPrivate::load(WTF::String const&), address = 0x000000010b3d6820, resolved, hit count = 0 
      12.18: where = WebCore`WebCore::MediaPlayerPrivateAVFoundation::load(WTF::String const&), address = 0x000000010b3d7880, resolved, hit count = 0 
      12.19: where = WebCore`WebCore::TextTrackLoader::load(WebCore::URL const&, WTF::String const&, bool), address = 0x000000010b8d89d0, resolved, hit count = 0 
      12.20: where = WebCore`WebCore::FrameLoader::load(WebCore::FrameLoadRequest const&), address = 0x000000010ada2570, resolved, hit count = 0 
      12.21: where = NLP`NL::SpotlightQueryConverter::load(NLSearchAppContext), address = 0x000000010fc3a4ca, resolved, hit count = 0 
      12.22: where = NLP`NL::SearchDateDisplayFormatter::load(), address = 0x000000010fc7c354, resolved, hit count = 0 
      12.23: where = libmarisa.dylib`marisa::Trie::load(char const*), address = 0x000000010fda4618, resolved, hit count = 0 
      12.24: where = JavaScriptCore`JSC::DFG::ByteCodeParser::load(unsigned int, unsigned int, JSC::DFG::GetByOffsetMethod const&, JSC::DFG::NodeType), address = 0x0000000110184900, resolved, hit count = 0 
      12.25: where = JavaScriptCore`JSC::DFG::ByteCodeParser::load(unsigned int, JSC::ObjectPropertyConditionSet const&, JSC::DFG::NodeType), address = 0x0000000110184ad0, resolved, hit count = 0 
    
    (lldb)

    在使用命令设置断点时,符合条件的断点可能不止一个,并且,如果新加载文件后,符合条件的断点可能还会增加。当然,设置不存在的断点,断点信息也可以查看得到,但是其 locations 为 0 。

    (lldb) breakpoint set --file test.m --line 100
    Breakpoint 13: no locations (pending).
    WARNING:  Unable to resolve breakpoint to any actual locations.
    (lldb) breakpoint list
    Current breakpoints:
    13: file = 'test.m', line = 100, exact_match = 0, locations = 0 (pending)
  2. 将断点置为不可用

    (lldb) breakpoint disable 1
    1 breakpoints disabled.
  3. 将断点置为可用

    (lldb) breakpoint enable 1
    1 breakpoints enabled.
  4. 删除断点

    (lldb) breakpoint delete 1
    1 breakpoints deleted; 0 breakpoint locations disabled.
  5. 为断点添加命令或脚本

    (lldb) breakpoint command add
    Enter your debugger command(s).  Type 'DONE' to end.
    > bt
    > DONE
    (lldb) breakpoint command list 2
    Breakpoint 2:
        Breakpoint commands:
          bt
    (lldb) 

    从下面的错误命令可知断点所支持的语言:

    (lldb) breakpoint command add -s OC
    error: invalid enumeration value, valid values are: "command", "python", "default-script"

观察变量

  1. 设置观察变量

    (lldb) watchpoint set variable backgroundColor
    Watchpoint created: Watchpoint 2: addr = 0x7fff52dcdb38 size = 8 state = enabled type = w
        declare @ '/Users/hanxuejian/Downloads/ThemeChange-master/TestTheme/TestTheme/UIView+Theme.m:31'
        watchpoint spec = 'backgroundColor'
        new value: 0x000061000007e780
  2. 查看观察变量

    (lldb) watchpoint list
    Number of supported hardware watchpoints: 4
    Current watchpoints:
    Watchpoint 1: addr = 0x7fff52dcd6d8 size = 8 state = disabled type = w
        declare @ '/Users/hanxuejian/Downloads/ThemeChange-master/TestTheme/TestTheme/UIView+Theme.m:31'
        watchpoint spec = 'backgroundColor'
        old value: 0xffff8067ddcff720
        new value: 0xffff8067ddcff720
    Watchpoint 2: addr = 0x7fff52dcdb38 size = 8 state = enabled type = w
        declare @ '/Users/hanxuejian/Downloads/ThemeChange-master/TestTheme/TestTheme/UIView+Theme.m:31'
        watchpoint spec = 'backgroundColor'
        new value: 0x000061000007e780
  3. 设置查看条件

    (lldb) watchpoint set variable num
    Watchpoint created: Watchpoint 1: addr = 0x10f932558 size = 4 state = enabled type = w
        declare @ '/Users/hanxuejian/Downloads/ThemeChange-master/TestTheme/TestTheme/UIView+Theme.m:31'
        watchpoint spec = 'num'
        new value: 16
    
    //添加条件
    (lldb) watchpoint modify -c "(num == 25)"
    (lldb) watchpoint list
    Number of supported hardware watchpoints: 4
    Current watchpoints:
    Watchpoint 1: addr = 0x10f932558 size = 4 state = enabled type = w
        declare @ '/Users/hanxuejian/Downloads/ThemeChange-master/TestTheme/TestTheme/UIView+Theme.m:31'
        watchpoint spec = 'num'
        old value: 20
        new value: 21
        condition = '(num == 25)'
    
    //条件达成
    2018-03-21 19:11:44.302 TestTheme[6938:828079] XPC connection interrupted
    
    Watchpoint 1 hit:
    old value: 21
    new value: 25

开始程序

使用 LLDB 调试程序,可以直接加载可执行程序,或者绑定已经在执行的程序,而后开始进行调试。

如下面的例子,先创建一个简单 C 程序。

#include <stdio.h>
int main(int argc, char const *argv[])
{ 
    int i = 1;
    while(true) {
        char *c = "this is a test";
        printf("%s %i\n", c,i++);   
    }
    return 0;
}

编辑后,保存为 test.cpp 文件,然后在命令行中执行下面的命令:

gcc test.cpp -o test

得到可执行文件,而后执行下面的命令。

(lldb) target create test
Current executable set to 'test' (x86_64).
(lldb) process launch test
Process 7169 launched: '/Users/hanxuejian/Desktop/Temp/test' (x86_64)
this is a test 1
this is a test 2
this is a test 3
this is a test 4

当然,也可以先运行 test 可执行文件,而后使用下面的命令进行调试绑定。

(lldb) process attach --pid 7232 
(lldb) process attach --name test 
(lldb) process attach --name test --waitfor

但是要注意的是,如果存在两个名称相同的进程,那么绑定是无法成功的。

线程控制

在加载进程开始调试后,当执行到设置断点时,可以使用 thread 命令控制代码的执行。

  1. 线程继续执行

    (lldb) thread continue 
    Resuming thread 0x2c03 in process 46915 
    Resuming process 46915 
    (lldb)
  2. 线程进入、单步执行或跳出

    (lldb) thread step-in    
    (lldb) thread step-over  
    (lldb) thread step-out
  3. 单步指令的执行

    (lldb) thread step-inst  
    (lldb) thread step-over-ins
  4. 执行指定代码行数直到退出当前帧

    (lldb) thread until 100
  5. 查看线程列表,第一个线程为当前执行线程

    (lldb) thread list
    Process 46915 state is Stopped
    * thread #1: tid = 0x2c03, 0x00007fff85cac76a, where = libSystem.B.dylib`__getdirentries64 + 10, stop reason = signal = SIGSTOP, queue = com.apple.main-thread
      thread #2: tid = 0x2e03, 0x0000
  6. 查看当前线程栈

    (lldb) thread backtrace
    thread #1: tid = 0x2c03, stop reason = breakpoint 1.1, queue = com.apple.main-thread
     frame #0: 0x0000000100010d5b, where = Sketch`-[SKTGraphicView alignLeftEdges:] + 33 at /Projects/Sketch/SKTGraphicView.m:1405
     frame #1: 0x00007fff8602d152, where = AppKit`-[NSApplication sendAction:to:from:] + 95
     frame #2: 0
    
    //查看所有线程的调用栈
    (lldb) thread backtrace all
  7. 设置当前线程

    (lldb) thread select 2

帧状态

查看当前线程中当前帧(或者说方法/函数)中的变量/参数,可以使用 frame 命令。

  1. 查看本地变量及参数

    (lldb) frame variable 
    (ViewController *) self = 0x00007f8289d08b50
    (SEL) _cmd = "testCoreGraphics"
    (TestView *) view = 0x00007f828c102760
    
    //指定要查看的变量
    ((lldb) frame variable self->isa
    (Class) self->isa = ViewController
  2. 打印对象

    (lldb) frame variable -o self
    (ViewController *) self = 0x00007f8289d08b50 <ViewController: 0x7f8289d08b50>
  3. 选择栈中的方法

    (lldb) frame select 2
    frame #2: 0x000000010ca7446c UIKit`-[UIViewController loadViewIfRequired] + 1235
    UIKit`-[UIViewController loadViewIfRequired]:
        0x10ca7446c <+1235>: movl   (%r14), %eax
        0x10ca7446f <+1238>: testl  %eax, %eax
        0x10ca74471 <+1240>: je     0x10ca7447f               ; <+1254>
        0x10ca74473 <+1242>: cmpl   $0x70000, %eax            ; imm = 0x70000 
    (lldb) 

修改变量或调用函数

使用 expression 命令可以在调试过程中修改变量的值,或者执行函数。

  1. 修改变量值

    (lldb) expression a
    (int) $0 = 9
    (lldb) frame variable a
    (int) a = 9
    (lldb) expression a=10
    (int) $1 = 10
    (lldb) frame variable a
    (int) a = 10
    (lldb) 
  2. 调用函数

    (lldb) expression printf("execute function %i",a)
    (int) $2 = 19
    execute function 10

    对于执行结果都会自动保存,以备他用。

猜你喜欢

转载自blog.csdn.net/u011374318/article/details/79648178