解析IOS崩溃日志(crash Log)
最近在解析umeng错误分析日志上有了重大突破！
很显然，我们的应用免不了crash，各种各样的crash，不过大部分在提交至appstore前经过严格的“消毒”后，所剩无几了。but（这个词..）漏网之鱼总是有的嘛（貌似很多..囧）。好吧，看下文：
首先看一些这些线上app crash 信息：
<span style="font-size:14px;">* Application received signal SIGSEGV * Application received signal SIGBUS * -[__NSArrayM objectAtIndex:]: index 4294967295 beyond bounds for empty array * -[JKArray objectAtIndex:]: index (0) beyond bounds (0)</span>
SIGSEGV和SIGBUS一般是因为访问已被释放的内存或者调用不存在的方法导致的，余下两个就是数组越界的问题了 这些你都知道的，然后来看看具体的log信息：
Application received signal SIGSEGV
<span style="font-size:14px;">Application received signal SIGSEGV (null) ( 0 CoreFoundation 0x32f1c3ff + 186 1 libobjc.A.dylib 0x3ac17963 objc_exception_throw + 30 2 CoreFoundation 0x32f1c307 + 106 3 appname 0x14e1e1 appname + 1364449 4 libsystem_c.dylib 0x3b08bd33 _sigtramp + 34 5 appname 0x97525 appname + 615717 6 CoreFoundation 0x32e6d349 _CFXNotificationPost + 1420 7 Foundation 0x337879cd + 168 8 Foundation 0x337876c1 + 136 9 appname 0x96f2f appname + 614191 10 Foundation 0x33858915 + 16 11 Foundation 0x33798769 + 200 12 Foundation 0x33798685 + 60 13 CFNetwork 0x32bf964f + 26 14 CFNetwork 0x32bf8d33 + 54 15 CFNetwork 0x32c21013 + 18 16 CoreFoundation 0x32e62acd CFArrayApplyFunction + 176 17 CFNetwork 0x32c21473 + 74 18 CFNetwork 0x32b85461 + 188 19 CoreFoundation 0x32ef18f7 + 14 20 CoreFoundation 0x32ef115d + 212 21 CoreFoundation 0x32eeff2f + 646 22 CoreFoundation 0x32e6323d CFRunLoopRunSpecific + 356 23 CoreFoundation 0x32e630c9 CFRunLoopRunInMode + 104 24 GraphicsServices 0x36a4233b GSEventRunModal + 74 25 UIKit 0x34d7f2b9 UIApplicationMain + 1120 26 appname 0xf3df appname + 58335 27 appname 0x3578 appname + 9592 ) dSYM UUID: 365EF56E-D598-3B94-AD36-BFA13772A4E3 CPU Type: armv7s Slide Address: 0x00001000 Binary Image: appname Base Address: 0x000f7000</span>
–[__NSArrayM objectAtIndex:]: index 4294967295 beyond bounds for empty array
<span style="font-size:14px;">*** -[__NSArrayM objectAtIndex:]: index 4294967295 beyond bounds for empty array (null) ( 0 CoreFoundation 0x330dc3ff + 186 1 libobjc.A.dylib 0x3add7963 objc_exception_throw + 30 2 CoreFoundation 0x33027ef9 + 164 3 appname 0xcbcaf appname + 830639 4 appname 0x40bc1 appname + 261057 5 appname 0x3d297 appname + 246423 6 UIKit 0x34f36569 + 408 7 UIKit 0x34f1b391 + 1316 8 UIKit 0x34f32827 + 206 9 UIKit 0x34eee8c7 + 258 10 QuartzCore 0x34c9a513 + 214 11 QuartzCore 0x34c9a0b5 + 460 12 QuartzCore 0x34c9afd9 + 16 13 QuartzCore 0x34c9a9c3 + 238 14 QuartzCore 0x34c9a7d5 + 316 15 QuartzCore 0x34c9a639 + 60 16 CoreFoundation 0x330b1941 + 20 17 CoreFoundation 0x330afc39 + 276 18 CoreFoundation 0x330aff93 + 746 19 CoreFoundation 0x3302323d CFRunLoopRunSpecific + 356 20 CoreFoundation 0x330230c9 CFRunLoopRunInMode + 104 21 GraphicsServices 0x36c0233b GSEventRunModal + 74 22 UIKit 0x34f3f2b9 UIApplicationMain + 1120 23 appname 0xf3df appname + 58335 24 appname 0x3578 appname + 9592 ) dSYM UUID: 365EF56E-D598-3B94-AD36-BFA13772A4E3 CPU Type: armv7s Slide Address: 0x00001000 Binary Image: appname Base Address: 0x000c3000</span>
好了，相信你也看出来了，这些具体的crash log 什么都看不出来，都是一些内存地址，帧调用栈等，所以需要进一步的解析，看下文：
看一下上面的crash log，找到一句
<span style="font-size:14px;">5 appname 0x97525 appname + 615717</span>
它指出了应用名称，崩溃时的调用方法的地址，文件的地址以及方法所在的行的位置（具体请看这篇文章），接下来就要符号化（Symbolication）这句,用dwarfdump来检测crash log中dSYM UUID和本地的dSYM文件是否匹配
打开终端：
<span style="font-size:14px;">cd /Users/username/Library/Developer/Xcode/Archives/2013-08-30/app 8-30-13 6.19 PM.xcarchive/dSYMs dwarfdump --uuid appname.app.dSYM UUID: 9F0AEFA6-4349-30AF-8420-BCEE739DA0B4 (armv7) appname.app.dSYM/Contents/Resources/DWARF/appname UUID: 365EF56E-D598-3B94-AD36-BFA13772A4E3 (armv7s) appname.app.dSYM/Contents/Resources/DWARF/appname</span>
OK,crash log中的dSYM UUID与本地的dYSM文件是相匹配的。好接下来就查一下0x97525这个地址是什么，
<span style="font-size:14px;">dwarfdump --arch=armv7 --lookup 0x97525 /Users/username/Library/Developer/Xcode/Archives/2013-08-30/appname\ 8-30-13\ 6.19\ PM.xcarchive/dSYMs/appname.app.dSYM/Contents/Resources/DWARF/appname</span>
得到的结果：
<span style="font-size:14px;">----------------------------------------------------------------------
File: /Users/username/Library/Developer/Xcode/ Archives/2013-08-30/appname 8-30-13 6.19 PM.xcarchive/dSYMs/appname.app.dSYM/Contents/ Resources/DWARF/appname (armv7)
----------------------------------------------------------------------
Looking up address: 0x0000000000097525 in .debug_info... found!
0x00359c67: Compile Unit: length = 0x000066f1 version = 0x0002 abbr_offset = 0x00000000 addr_size = 0x04 (next CU at 0x0036035c)
0x00359c72: TAG_compile_unit [1] *
AT_producer( "Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)" )
AT_language( DW_LANG_ObjC )
AT_name( "xxx/EGOImageView.m" )
AT_low_pc( 0x0009710c )
AT_stmt_list( 0x000655c1 )
AT_comp_dir( "xxx" )
AT_APPLE_optimized( 0x01 )
AT_APPLE_major_runtime_vers( 0x02 )
0x00359e57: TAG_subprogram [10] *
AT_name( "-[EGOImageView imageLoaderDidFailToLoad:]" )
AT_decl_file( "xxx/EGOImageView.m" )
AT_decl_line( 96 )
AT_prototyped( 0x01 )
AT_APPLE_isa( 0x01 )
AT_low_pc( 0x00097490 )
AT_high_pc( 0x00097572 )
AT_frame_base( r7 )
AT_object_pointer( {0x00359e6e} )
Line table dir : 'xxx'
Line table file: 'EGOImageView.m' line 99, column 2 with start address 0x00000000000974fe
Looking up address: 0x0000000000097525 in .debug_frame... found!
0x0000c620: FDE
length: 0x0000000c
CIE_pointer: 0x00000000
start_addr: 0x00097490 -[EGOImageView imageLoaderDidFailToLoad:]
range_size: 0x000000e2 (end_addr = 0x00097572)
Instructions: 0x00097490: CFA=4294967295+4294967295</span>
看一下结果：发现有AT_name、Line table dir :、Line table file:，aha!找到了出错的地方（出错的这个文件是网上别人写的，有bug，现已不再使用）。