iphone ios XCode4如何调试程序忽然崩溃而找不到挂的代码

XCode4设置不太一样: 在Edit–>Scheme里面 找到Arguments(在xcode 4.2中，在菜单 product->edit scheme中）

把下面3个值设置成YES

NSAutoreleaseFreedObjectCheckEnabled

NSZombieEnabled

NSDebugEnabled

MallocStackLogging

LLDB->GDB (才能使用shell命令）

另外转载2篇调试EXC_BAD_ACCESS的好文

http://blog.zol.com.cn/2387/article_2386505.html

/article/4690738.html

老外也有这么说的：

I had similar issue; turns out
I was not retaining a UIButton properly. How I found the cause: - Enable zombies - Run the project with 'Allocations' instrument - Use the app to trigger the bug - Check that Instruments show message 'Zombie Messaged' on the timeline - There should be a link
that opens CALayer details: when it was allocated and deallocated - You are interested in the place where is was allocated, should be that aha!!! place in your code

我是用模拟器上
使用zombies，然后运行程序，崩溃的时候会有提示崩溃点，同时有代码。

转另一个人文章：

方法一：
PAEHoldTranMainControl *control = [[PAEHoldTranMainControl alloc]init];
[self.navigationController pushViewController:control animated:YES];

[control release];
alloc了一个control,release,运行就崩溃了。而且没有任何提示，console里只显示exc_bad_access
利用NSZombieEnabled参数，MallocStackLogging参数，显示 -[CALayer release]: message sent to deallocated instance 0x13570810

折腾了半天，最后用如下方法定位问题：
打开instrument-->ios simulator：(xcode4.6 profile选项）

选择all－－》 zombies运行，断开时，查看stack trace，即可跟踪

方法二：例如console里的输出如下：（需要打开MallocStackLogging:YES, LLDB->GDB选项)
TestAPP[1472:207] *** -[NSObject release]: message sent to deallocated instance 0x6019170

在 gdb console 里面， 运行 shell malloc_history <pid> <mem_address>

pid = process ID (e.g. 1472)

mem_address = memory address of instance (e.g. 0x6019170)

即会出现调用栈