最近項目中總是碰到libsystem_kernel.dylib`__pthread_kill + 8, stop reason = signal SIGABRT
類似於這樣的錯誤，但是出現這樣的錯誤之后總是無法定位問題具體的位置。
(lldb) bt
* thread #1: tid = 0x2403, 0x31c16350 libsystem_kernel.dylib`__pthread_kill + 8, stop reason = signal SIGABRT
frame #0: 0x31c16350 libsystem_kernel.dylib`__pthread_kill + 8
frame #1: 0x34fa5122 libsystem_c.dylib`pthread_kill + 58
frame #2: 0x34fe1972 libsystem_c.dylib`abort + 94
frame #3: 0x38101d4e libc++abi.dylib`abort_message + 74
frame #4: 0x380ff0da libc++abi.dylib`safe_handler_caller(void (*)()) + 174
frame #5: 0x380ff114 libc++abi.dylib`std::terminate() + 20
frame #6: 0x38100598 libc++abi.dylib`__cxa_rethrow + 88
frame #7: 0x33e0f9d0 libobjc.A.dylib`objc_exception_rethrow + 12
frame #8: 0x39e66f20 CoreFoundation`CFRunLoopRunSpecific + 456
frame #9: 0x39e66d48 CoreFoundation`CFRunLoopRunInMode + 104
frame #10: 0x382342ea GraphicsServices`GSEventRunModal + 74
frame #11: 0x330a62f8 UIKit`UIApplicationMain + 1120
frame #12: 0x0001174c XingVelo3`main + 152 at main.m:16
方法一
通過在Xcode的控制台里面打印具體的值
主要命令是bt 或者thread backtrace
-
If you're using gdb, use
btto print the backtrace -
If you're using lldb, use
thread backtraceinstead
出現錯誤之后把信息打印出來，然后追蹤具體的位置。但是僅僅這樣還不夠，很多信息看不到。
方法二，設置exception breakpoint
這個方法可以直接定位到出錯的位置，非常強大，也是最近才發現的。
添加exception break point的方法，下面是說明。
If you're running your app out of Xcode, add an exception breakpoint. In the breakpoint navigator (command-6) hit the '+' at the very bottom left to add. This will pause execution on the line that throws the exception and allow you to inspect the current scope, stack, etc.