问题
OK, SO I've received a crash report for one of my apps, but I swear I'm 100% confused.
This is what the "core" part of it looks like :
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
VM Regions Near 0:
-->
__TEXT 0000000100000000-0000000100015000 [ 84K] r-x/rwx SM=COW /Applications/MY_APP/Contents/MacOS/MY_APP
Application Specific Information:
objc[337]: garbage collection is ON
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libsystem_c.dylib 0x00007fff90128650 strlen + 16
1 MY_BUNDLE_ID 0x0000000100008f12 0x100000000 + 36626
2 MY_BUNDLE_ID 0x000000010000b435 0x100000000 + 46133
3 MY_BUNDLE_ID 0x0000000100003c90 0x100000000 + 15504
4 com.apple.CoreFoundation 0x00007fff9065147a _CFXNotificationPost + 2554
5 com.apple.Foundation 0x00007fff8e5fe846 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
6 com.apple.AppKit 0x00007fff9a7894a7 -[NSTableView textDidChange:] + 377
7 com.apple.CoreFoundation 0x00007fff9065147a _CFXNotificationPost + 2554
8 com.apple.Foundation 0x00007fff8e5fe846 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
9 com.apple.AppKit 0x00007fff9a15c260 -[NSTextView(NSSharing) didChangeText] + 339
10 com.apple.AppKit 0x00007fff9a7f8381 _NSDoUserReplaceForCharRange + 390
11 com.apple.AppKit 0x00007fff9a7f85b1 _NSDoUserDeleteForCharRange + 38
12 com.apple.AppKit 0x00007fff9a7e1e72 -[NSTextView(NSKeyBindingCommands) deleteBackward:] + 440
13 com.apple.AppKit 0x00007fff9a18a1cc -[NSResponder doCommandBySelector:] + 75
14 com.apple.AppKit 0x00007fff9a18a02e -[NSTextView doCommandBySelector:] + 197
15 com.apple.AppKit 0x00007fff9a20cf4e -[NSKeyBindingManager(NSKeyBindingManager_MultiClients) interpretEventAsCommand:forClient:] + 2200
16 com.apple.AppKit 0x00007fff9a20c3bb -[NSTextInputContext handleEvent:] + 939
17 com.apple.AppKit 0x00007fff9a20bf87 -[NSView interpretKeyEvents:] + 183
18 com.apple.AppKit 0x00007fff9a158f67 -[NSTextView keyDown:] + 723
19 com.apple.AppKit 0x00007fff9a374120 -[NSWindow sendEvent:] + 9687
20 com.apple.AppKit 0x00007fff9a36f744 -[NSApplication sendEvent:] + 5761
21 com.apple.AppKit 0x00007fff9a2852fa -[NSApplication run] + 636
22 com.apple.AppKit 0x00007fff9a229cb6 NSApplicationMain + 869
23 MY_BUNDLE_ID 0x0000000100002014 0x100000000 + 8212
Do you have any idea what might be going wrong? Or could you just point me to the right direction?
As an aside :
Could anyone guide me how to make e.g. 0x00007fff90128650 more... meaningful and make it (in some future crash report) also show the name of the function?
回答1:
Your crash log give you lot of informations: first you crashed because you tried to access to address 0 into ur program and kernel is not happy.
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
See, you get a segmentation, by the way it's starting to the 0x00 address, so it's like you're directly accessing a 0 / nil pointer. Like this
char* adress = 0;
printf("get %p", adress); // will output 0x0
printf("get %p", adress[0]); // will make a EXC_BAD_ACCESS
You should really focus on this.
From the crash stack there is three interesting things:
6 com.apple.AppKit 0x00007fff9a7894a7 -[NSTableView textDidChange:] + 377
5 com.apple.Foundation 0x00007fff8e5fe846 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
0 libsystem_c.dylib 0x00007fff90128650 strlen + 16
[textDidChange] is one of the last call who caused the crash, by the way you're sending a notification when the [textDidChange] is fired. And last line who actually make the crash: strlen + 16 is because there's something who think it can get a char length from a valid pointer address and it's actually not the case.
According to me, you should check what you're sending into your notification.
_NSDoUserReplaceForCharRange
_NSDoUserDeleteForCharRange
When you look deeply into the stack crash, it really seems that's it's appearing when you make cell - insertion / deletion into ur tableViewController. You should check that sometime someone push invalid data, or not using the edit cell the way it's supposed to be.
So here's the resume: 1 Someone edit a tableViewCell, he doesn't insert or code doesn't insert what it's supposed to be. 2 You're sending a notification with a non-valid data inside it. 3 When the strlen(invalid_dataStructure) is fired, it make ur app crash
By the way i'm just "guessing", since i don't know actually your code implementation. But i hope it can give you lots of clues for your debugging session.
回答2:
Usually the problem is that you need a "retain" property.
You need to enable Zombies for debug mode. in xCode 4 click "edit scheme"->"Diagnostics"->"Enable Zombie Objects"
It will show you in console what "removed" object you try to access when crashing.
this should help.
you will see somthing like this:
2010-01-25 14:35:24.840 MyApplication[1393:20b] *** -[CFString retain]: message sent to deallocated instance 0x42a5060
You can also enable "Malloc logging" and after crash enter such command in debug console:
shell malloc_history 1393 0x42a5060
there you can find all alloc/release stack. just look at release and alloc commands.
回答3:
I got a very similar crash report trying to open graphic-heavy applications (pymol and coot) (See below)
I found out that if I disconnected my mac from my external monitor, the programs worked again. I was using a USB-HDMI connector - apparently this is a bad idea. I just purchased a microUSB-HDMI connector and I expect this will work better. The programs run if I just use my mac book's own monitor display.
Time Awake Since Boot: 19000 seconds
Time Since Wake: 110 seconds
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
VM Regions Near 0:
-->
__TEXT 0000000100000000-0000000100cff000 [ 13.0M] r-x/rwx SM=COW /Applications/MacPyMOL.app/Contents/MacOS/MacPyMOL
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 com.apple.opengl 0x00007fff8333857c CGLDescribeRenderer + 79
1 com.schrodinger.macpymol 0x000000010083c5b4 CheckOpenGLCaps + 484
2 com.schrodinger.macpymol 0x000000010084cd8c -[PyMOLOpenGLView awakeFromNib] + 1420
3 com.apple.CoreFoundation 0x00007fff8a10785f -[NSSet makeObjectsPerformSelector:] + 223
4 com.apple.AppKit 0x00007fff88b935cd -[NSIBObjectData nibInstantiateWithOwner:options:topLevelObjects:] + 1216
5 com.apple.AppKit 0x00007fff886a3605 loadNib + 384
6 com.apple.AppKit 0x00007fff88c14749 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:options:withZone:ownerBundle:] + 727
7 com.apple.AppKit 0x00007fff88c14ca8 +[NSBundle(NSNibLoadingInternal) _loadNibFile:externalNameTable:options:withZone:] + 150
8 com.apple.AppKit 0x00007fff886a2bc0 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 631
9 com.schrodinger.macpymol 0x000000010084d77b main + 1499
10 com.schrodinger.macpymol 0x0000000100007494 start + 52
来源：https://stackoverflow.com/questions/12878966/having-trouble-with-a-crash-report-exc-bad-access