daydreamboy / lldb_scripts

a repo for lldb scripts used in .lldbinit file

lldb_scripts

[TOC]

1、自定义lldb命令

本文主要介绍如何自定义lldb命令，不涉及lldb中的调试（参考HelloLLDB工程）。

创建自定义lldb命令，主要有两种方式

• 创建简短命令

  • 主要是将较长的命令和参数，定义别名，方便快捷使用
  • 参考“LLDB commands”一节

• 创建python脚本，脚本提供命令

  • 主要通过脚本完成复杂的功能，比如下载pod库的源码，关联当前二进制文件等
  • 参考“LLDB scripts”一节

2、LLDB commands¹

(1) ivars

ivars命令查看对象的实例变量

# Get all the ivars
(lldb) ivars <object>

配置代码，如下

command regex ivars -h "Dumps all ivars for an instance of a particular class which inherits from NSObject (iOS, NSObject subclass only)" -s "ivars [UIView new]" -- 's/(.+)/expression -lobjc -O -- [%1 _ivarDescription]/'

(2) methods/methods_r

methods命令查看对象的所有方法，methods_r命令查看对象的所有方法以及父类的所有方法

# Get all the methods of UIView
(lldb) methods UIView

配置代码，如下

# methods
command regex methods -h "Dumps all methods implemented by the NSObject subclass (iOS, NSObject subclass only)" -s "methods UIView" -- 's/(.+)/expression -lobjc -O -- [%1 _shortMethodDescription]/'

# methods_r
command regex methods_r -h "Dumps all methods implemented by the NSObject subclass (iOS, NSObject subclass only)" -s "methods UIView" -- 's/(.+)/expression -lobjc -O -- [%1 _methodDescription]/'

(3) pprotocol

打印某个协议的所有方法 (仅适用于Objective-C代码)

# Dump the protocol for UITableViewDataSource
(lldb) pprotocol UITableViewDataSource

配置代码，如下

# pprotocol
command regex pprotocol 's/(.+)/expression -lobjc -O -- @import Foundation; NSMutableString *string = [NSMutableString string]; Protocol * prot = objc_getProtocol("%1"); [string appendFormat:@"\nProtocol: %s, %@\n", (char *)[prot name], (id)prot]; [string appendString:@"==========================================\n"]; for (int isRequired = 1; isRequired > -1; isRequired--) { [string appendFormat:@" (%@)\n", isRequired ? @"Required" : @"Optional"]; for (int isInstanceMethod = 0; isInstanceMethod < 2; isInstanceMethod++) { unsigned int ds_count = 0; struct objc_method_description * methods = (struct objc_method_description *)protocol_copyMethodDescriptionList(prot, (BOOL)isRequired, (BOOL)isInstanceMethod, &ds_count); for (int i = 0; i < ds_count; i++) { struct objc_method_description method = methods[i]; [string appendFormat:@"%@ %@, %s\n", isInstanceMethod ? @"-": @"+", NSStringFromSelector(method.name), method.types]; }}} string;/'

示例使用

(lldb) pprotocol UITableViewDataSource

Protocol: UITableViewDataSource, <Protocol: 0x7fff89e22458>
==========================================
 (Required)
- tableView:numberOfRowsInSection:, q32@0:8@16q24
- tableView:cellForRowAtIndexPath:, @32@0:8@16@24
 (Optional)
- tableView:titleForHeaderInSection:, @32@0:8@16q24
- tableView:commitEditingStyle:forRowAtIndexPath:, v40@0:8@16q24@32
- tableView:titleForFooterInSection:, @32@0:8@16q24
- numberOfSectionsInTableView:, q24@0:8@16
- tableView:canEditRowAtIndexPath:, B32@0:8@16@24
- tableView:canMoveRowAtIndexPath:, B32@0:8@16@24
- sectionIndexTitlesForTableView:, @24@0:8@16
- tableView:sectionForSectionIndexTitle:atIndex:, q40@0:8@16@24q32
- tableView:moveRowAtIndexPath:toIndexPath:, v40@0:8@16@24@32

(4) tv

tv命令用于切换UIView对象的hidden状态

# Toggle a view on or off
(lldb) tv [UIView new]

配置代码，如下

command regex -h "Toggle view. Hides/Shows a view depending on it's current state. You don't need to resume LLDB to see changes" -s "tv 0xUIViewAddress" -- tv 's/(.+)/expression -l objc -O -- @import QuartzCore; [%1 setHidden:!(BOOL)[%1 isHidden]]; (void)[CATransaction flush];/'

(5) rlook

配置代码，如下

# rlook
command regex -h "Regex search" -s "rlook UIViewController.viewDidLoad" -- rlook 's/(.+)/image lookup -rn %1/'

(6) reload_lldbinit

当.lldbinit文件内容被修改，可以不用重新启动lldb，使用reload_lldbinit命令重新加载.lldbinit文件

配置代码，如下

command alias -H "Reload ~/.lldbinit" -h "Reload ~/.lldbinit" -- reload_lldbinit command source ~/.lldbinit

(7) args

读取方法Call Convention的1-6个参数，配置代码，如下

command alias args register read arg1 arg2 arg3 arg4 arg5 arg6

(8) python_version

打印python的版本²。配置代码，如下

# python_version
command alias -H "Check Python version" -h "Check Python version" -- python_version script import sys; print(sys.version)

(9) pimage

打印UIImage的debug信息。配置代码，如下

# pimage
command regex pimage 's/(.+)/expression -lobjc -O -- @import Foundation; NSMutableString *_debugInfoM_ = [NSMutableString string]; UIImage *_image_ = (UIImage *)%1; if ([_image_ isKindOfClass:[UIImage class]]) { NSString *_fileName_ = nil; NSString *_containerBundlePath_ = nil; if ([_image_ respondsToSelector:@selector(imageAsset)]) { UIImageAsset *imageAsset = _image_.imageAsset; _fileName_ = [imageAsset valueForKey:@"_assetName"]; _containerBundlePath_ = [imageAsset valueForKey:@"_containingBundle"]; } _debugInfoM_ = [[NSMutableString alloc] initWithFormat:@"<%@: %p> %@ %@ %@", [_image_ class], _image_, _fileName_, (id)NSStringFromCGSize(_image_.size), (NSString *)[_containerBundlePath_ bundlePath]]; } _debugInfoM_;/'

(10) paddr

在Swift中打印内存地址³。

配置代码，如下

command regex paddr -h "Print memory address in Swift code" -s "paddr 0x123" -- 's/(.+)/expression -lswift -O -- unsafeBitCast(%1, to: NSObject.self)/'

或者

command regex paddr -h "Print memory address in Swift code" -s "paddr 0x123" -- 's/(.+)/expression -lswift -O -- unsafeBitCast(%1, to: AnyObject.self)/'

// TODO

(lldb) visualize attrStringM
NSConcreteMutableAttributedString isn't supported. You can visualize UIImage, CGImageRef, UIView, CALayer, NSData, UIColor, CIColor, or CGColorRef.

3、LLDB scripts

(1) write命令

command script import ~/lldb_scripts/lldb_command_write.py

使用示例

(lldb) write -h

(2) ignore_specified_objc_exceptions命令

使用方法，如下

Usage:
1. place this script at ~/lldb
2. create an All Objective-C Exceptions breakpoint by Xcode
3. add a new Debugger Command, and type the formatted command

ignore_specified_objc_exceptions name:<exception name1> name:<exception name2> ...

代码见，ignore_specified_objc_exceptions.py

(3) auto_add_dsym命令

自动关联本地的dSYM文件

思路：

• br设置main函数断点
• target stop-hook，获取当前image的uuid
• mdfind "com_apple_xcode_dsym_uuids == 58028507-63B8-32C3-AD1C-9FDB2C8251DC"，获取dSYM为路径
• 使用add-dsym设置dSYM
• 然后执行continue

4、配置.lldbinit文件

(1) lldb_load_commands.py⁴

.lldbinit文件位于~/.lldbinit，增加下面一行命令，如下

command script import ~/lldb_scripts/lldb_load_commands.py

lldb_load_commands.py的作用是批量加载lldb命令

• 读取lldb_commands.txt文件
• 同级目录下带前缀lldb_command_的python脚本

python脚本的内容，示例如下

import lldb
import os


def __lldb_init_module(debugger, internal_dict):
    file_path = os.path.realpath(__file__)
    dir_name = os.path.dirname(file_path)
    load_python_scripts_dir(dir_name)


def load_python_scripts_dir(dir_name):
    this_files_basename = os.path.basename(__file__)
    cmd = ''
    for file in os.listdir(dir_name):
        if file.endswith('.py') and file.startswith('lldb_command_'):
            cmd = 'command script import '
        elif file.endswith('.txt'):
            cmd = 'command source -e0 -s1 '
        else:
            continue

        if file != this_files_basename:
            fullpath = dir_name + '/' + file
            lldb.debugger.HandleCommand(cmd + fullpath)

这里使用HandleCommand函数来执行command script或command source命令。

5、lldb模块

lldb提供一个名为lldb的python模块，该模块的API文档，见地址：https://lldb.llvm.org/python_reference/

References

Footnotes

1. https://github.com/DerekSelander/LLDB ↩

2. https://stackoverflow.com/questions/1093322/how-do-i-check-what-version-of-python-is-running-my-script ↩

3. https://stackoverflow.com/questions/29441418/lldb-swift-casting-raw-address-into-usable-type ↩

4. https://github.com/DerekSelander/LLDB/blob/master/lldb_commands/dslldb.py ↩