xCode4设置NSZombieEnabled

今天看到偶然间看到一篇blog，“用NSZombieEnabled解决恼人的EXC_BAD_ACCESS错误”。

很实用的技巧，便拿来试验一下。

原文是在XCode3里面设置的，so在4里面完全找不到地方。stackoverflow搜一下，找到如下方法。

菜单里Product->EditScheme->Run->EnvironmentVariables, 添加NSZombieEnabled，YES。

顺便发现方法2，Product->按住alt/option+鼠标点"Run...",之后同上。

如果你和我一样操作了，一定发现了：按下alt/option键之后菜单边了，同理，按下Ctrl键之后菜单也变了。

神奇ing！

顺便在Navigate看到一条”Fix nextissue“，（按住Ctrl）,原来XCode支持自动修复简单错误。

试验发现只要报错信息里有fix方法的，都能用Ctrl+Command+'修复。

In the Xcode IDE two environment variables are useful for gettingfurther information on the memory allocation error EXC_BAD_ACCESSwhen using the simulator: 

NSZombieEnabled=YESMallocStackLoggingNoCompact=1

There variables should be unchecked when not debugging specificmemory issues, as they will cause the memory shortages in theruntime environment, and should never be enabled in a shippingapplication. This is indicated by the followingmessage: 

"Data Formatters temporarily unavailable, will re-try after a'continue'. (Not safe to call dlopen at thistime.)" 

Uncheck these environment variables to resolve the issue.

Resolution

To set these environment variables in the XcodeIDE. 

In Xcode 3.2: 
- In the left pane of Xcodeexpand Executables 
- Select the application executable 
-Select File | GetInfo 
- Selectthe Arguments segmentcontrol 
- At the bottom of the Variables to be setin the environment dialogueclick + 
-Enter NSZombieEnable forthe nameand YES for thevalue 
-Click + again 
-Enter MallocStackLoggingNoCompact forthe nameand 1 for thevalue 
- Close the dialogue 

In Xcode 4.0: 
-Select Product | EditScheme from themenu 
- Select the appropriate scheme (Run/Test) in theleft pane 
- Selectthe Arguments segmentcontrol 
- At the bottom of the EnvironmentVariables dialogueclick + 
-Enter NSZombieEnable forthe nameand YES for thevalue 
-Click + again 
-Enter MallocStackLoggingNoCompact forthe nameand 1 for thevalue 
- Close the dialogue 

Recreate the fault. An error should appear in the debugger console(Run | Console). 

*** -[__NSArrayI release]: message sent to deallocated instance 0x4d90af0

This address is then used to query the debuggerwith infomalloc-history: 

(gdb) info malloc-history 0x4d90af0 （注：只能在模拟器上使用）

That will produce the following output: 

Alloc: Block address: 0x04d90af0 length: 32Stack - pthread: 0xa0078540 number of frames: 37    0: 0x90e5a103 in malloc_zone_calloc    1: 0x5d862 in NSAllocateScannedUncollectable    2: 0xa659b in _NSInitializeCacheLine    3: 0xa6318 in _sortedObjectsUsingDescriptors    4: 0x127c89 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]    5: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177    6: 0x604d in -[AViewController viewDidLoad] at /Application/Classes/AViewController.m:50    7: 0x3a965e in -[UIViewController view]    8: 0x3a7a57 in -[UIViewController contentScrollView]    9: 0x3b8201 in -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:]   10: 0x3b6831 in -[UINavigationController _layoutViewController:]   11: 0x3b7b4c in -[UINavigationController _startTransition:fromViewController:toViewController:]   12: 0x3b2606 in -[UINavigationController _startDeferredTransitionIfNeeded]   13: 0x4cae01 in -[UILayoutContainerView layoutSubviews]   14: 0x1e87451 in -[CALayer layoutSublayers]   15: 0x1e8717c in CALayerLayoutIfNeeded   16: 0x1e87088 in -[CALayer layoutIfNeeded]   17: 0x3aab5f in -[UIViewController window:willAnimateRotationToInterfaceOrientation:duration:]   18: 0x3238e9 in -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:]   19: 0x5a2948 in -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:]   20: 0x3ad982 in -[UIViewController presentModalViewController:withTransition:]   21: 0x3a6269 in -[UIViewController _tryRecursivelyPresentModalViewController:withTransition:]   22: 0x3ad085 in -[UIViewController presentModalViewController:withTransition:]   23: 0x4bc0 in -[RootViewController tableView:didSelectRowAtIndexPath:] at /Application/Classes/RootViewController.m:98   24: 0x371794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:]   25: 0x367d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:]   26: 0x7a7f6 in __NSFireDelayedPerform   27: 0x128afe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__   28: 0x128c594 in __CFRunLoopDoTimer   29: 0x11e8cc9 in __CFRunLoopRun   30: 0x11e8240 in CFRunLoopRunSpecific   31: 0x11e8161 in CFRunLoopRunInMode   32: 0x1ae9268 in GSEventRunModal   33: 0x1ae932d in GSEventRun   34: 0x30a42e in UIApplicationMain   35: 0x2914 in main at /Application/main.m:14   36: 0x28a5 in startDealloc: Block address: 0x04d90af0Stack - pthread: 0xa0078540 number of frames: 35    0: 0x90e5e1ad in malloc_zone_free    1: 0xa64bb in _sortedObjectsUsingDescriptors    2: 0x127c89 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]    3: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177    4: 0x604d in -[AViewController viewDidLoad] at /Application/Classes/AViewController.m:50    5: 0x3a965e in -[UIViewController view]    6: 0x3a7a57 in -[UIViewController contentScrollView]    7: 0x3b8201 in -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:]    8: 0x3b6831 in -[UINavigationController _layoutViewController:]    9: 0x3b7b4c in -[UINavigationController _startTransition:fromViewController:toViewController:]   10: 0x3b2606 in -[UINavigationController _startDeferredTransitionIfNeeded]   11: 0x4cae01 in -[UILayoutContainerView layoutSubviews]   12: 0x1e87451 in -[CALayer layoutSublayers]   13: 0x1e8717c in CALayerLayoutIfNeeded   14: 0x1e87088 in -[CALayer layoutIfNeeded]   15: 0x3aab5f in -[UIViewController window:willAnimateRotationToInterfaceOrientation:duration:]   16: 0x3238e9 in -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:]   17: 0x5a2948 in -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:]   18: 0x3ad982 in -[UIViewController presentModalViewController:withTransition:]   19: 0x3a6269 in -[UIViewController _tryRecursivelyPresentModalViewController:withTransition:]   20: 0x3ad085 in -[UIViewController presentModalViewController:withTransition:]   21: 0x4bc0 in -[RootViewController tableView:didSelectRowAtIndexPath:] at /Application/Classes/RootViewController.m:98   22: 0x371794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:]   23: 0x367d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:]   24: 0x7a7f6 in __NSFireDelayedPerform   25: 0x128afe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__   26: 0x128c594 in __CFRunLoopDoTimer   27: 0x11e8cc9 in __CFRunLoopRun   28: 0x11e8240 in CFRunLoopRunSpecific   29: 0x11e8161 in CFRunLoopRunInMode   30: 0x1ae9268 in GSEventRunModal   31: 0x1ae932d in GSEventRun   32: 0x30a42e in UIApplicationMain   33: 0x2914 in main at /Application/main.m:14   34: 0x28a5 in startAlloc: Block address: 0x04d90af0 length: 24Stack - pthread: 0xa0078540 number of frames: 40    0: 0x90e5a103 in malloc_zone_calloc    1: 0x90e5a05a in calloc    2: 0x13fdd0f in _internal_class_createInstanceFromZone    3: 0x140087d in class_createInstance    4: 0x123e687 in __CFAllocateObject2    5: 0x12a2d64 in +[__NSArrayI __new::]    6: 0x121faba in +[NSArray arrayWithObjects:count:]    7: 0x127ca9 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]    8: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177    9: 0x604d in -[AViewController viewDidLoad] at /Application/Classes/AViewController.m:50   10: 0x3a965e in -[UIViewController view]   11: 0x3a7a57 in -[UIViewController contentScrollView]   12: 0x3b8201 in -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:]   13: 0x3b6831 in -[UINavigationController _layoutViewController:]   14: 0x3b7b4c in -[UINavigationController _startTransition:fromViewController:toViewController:]   15: 0x3b2606 in -[UINavigationController _startDeferredTransitionIfNeeded]   16: 0x4cae01 in -[UILayoutContainerView layoutSubviews]   17: 0x1e87451 in -[CALayer layoutSublayers]   18: 0x1e8717c in CALayerLayoutIfNeeded   19: 0x1e87088 in -[CALayer layoutIfNeeded]   20: 0x3aab5f in -[UIViewController window:willAnimateRotationToInterfaceOrientation:duration:]   21: 0x3238e9 in -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:]   22: 0x5a2948 in -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:]   23: 0x3ad982 in -[UIViewController presentModalViewController:withTransition:]   24: 0x3a6269 in -[UIViewController _tryRecursivelyPresentModalViewController:withTransition:]   25: 0x3ad085 in -[UIViewController presentModalViewController:withTransition:]   26: 0x4bc0 in -[RootViewController tableView:didSelectRowAtIndexPath:] at /Application/Classes/RootViewController.m:98   27: 0x371794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:]   28: 0x367d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:]   29: 0x7a7f6 in __NSFireDelayedPerform   30: 0x128afe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__   31: 0x128c594 in __CFRunLoopDoTimer   32: 0x11e8cc9 in __CFRunLoopRun   33: 0x11e8240 in CFRunLoopRunSpecific   34: 0x11e8161 in CFRunLoopRunInMode   35: 0x1ae9268 in GSEventRunModal   36: 0x1ae932d in GSEventRun   37: 0x30a42e in UIApplicationMain   38: 0x2914 in main at /Application/main.m:14   39: 0x28a5 in start

The cause of this error is visible near the top of theblock: 

...4: 0x127c89 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]5: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177...2: 0x127c89 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]3: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177...7: 0x127ca9 in -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:]8: 0x24b0d in -[Task getFullSession:intoArray:] at /Application/Task.m:177