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Re: NSClassSwapper leaving dangling pointers?
From: |
Fred Kiefer |
Subject: |
Re: NSClassSwapper leaving dangling pointers? |
Date: |
Sat, 22 Jun 2013 00:02:23 +0200 |
Could you please provide a longer bavktrace to verify your statement that the
instantiateRealObject: call is about an NSPopupButton object? I am currently
away from my computer and wont be able to inspet the code for two more weeks,
but I would like to help in understanding the issue.
Fred
On the road
Am 21.06.2013 um 17:30 schrieb Luboš Doležel <address@hidden>:
> Hi,
>
> I'm still working on getting the latest The Unarchiver for OS X
> <http://wakaba.c3.cx/s/apps/unarchiver.html> working under
> GNUstep/Darling/Linux and I'm seeing crashes after the application's NIB file
> is loaded.
>
> Now I'm sort of helpless. The crash happens when using the target of a
> certain NSMenuItem.
>
> You can see an excerpt of the relevant NIB's source here; the NSMenuItem
> clearly refers to the NSPopUpButtonCell that it is part of:
>
> <object class="NSPopUpButtonCell" key="NSCell" id="824605593">
> <int key="NSCellFlags">-2076180416</int>
> <int key="NSCellFlags2">2048</int>
> <reference key="NSSupport" ref="170887875"/>
> <reference key="NSControlView" ref="790450297"/>
> <int key="NSButtonFlags">109199360</int>
> <int key="NSButtonFlags2">1</int>
> <reference key="NSAlternateImage" ref="538669737"/>
> <string key="NSAlternateContents"/>
> <object class="NSMutableString" key="NSKeyEquivalent">
> <characters key="NS.bytes"/>
> </object>
> <int key="NSPeriodicDelay">400</int>
> <int key="NSPeriodicInterval">75</int>
>
> <object class="NSMenuItem" key="NSMenuItem" id="444300673">
> <reference key="NSMenu" ref="552121880"/>
> <string key="NSTitle">dummy</string>
> <string key="NSKeyEquiv"/>
> <int key="NSKeyEquivModMask">1048576</int>
> <int key="NSMnemonicLoc">2147483647</int>
> <int key="NSState">1</int>
> <reference key="NSOnImage" ref="1019969751"/>
> <reference key="NSMixedImage" ref="16787521"/>
> <string key="NSAction">_popUpItemAction:</string>
> <reference key="NSTarget" ref="824605593"/>
> </object>
>
> (Full code can be found in The Unarchiver's source tarball in
> MainMenu.nib/designable.nib)
>
> I can see the target being set correctly via -setTarget upon loading:
>
> Breakpoint 3, -[NSMenuItem setTarget:] (self=0x1845808, _cmd=0x7ffff7a51eb0
> <.objc_selector_list+176>, anObject=0x1843d58) at NSMenuItem.m:465
> 465 if (_target == anObject)
> (gdb) p anObject
> $15 = (id) 0x1843d58
> (gdb) p anObject->isa
> $16 = (struct objc_class *) 0x7ffff7a6bcc0 <_OBJC_CLASS_NSPopUpButtonCell>
>
> Backtrace:
>
> #0 -[NSMenuItem setTarget:] (self=0x189de68, _cmd=0x7ffff79f7ce0
> <.objc_selector_list+640>, anObject=0x1429f18) at NSMenuItem.m:465
> #1 0x00007ffff745354e in -[NSNibControlConnector establishConnection]
> (self=0x189de38, _cmd=0x7ffff7afe330 <.objc_selector_list+1232>) at
> NSBundleAdditions.m:177
> #2 0x00007ffff76cfb91 in -[NSIBObjectData
> nibInstantiateWithOwner:topLevelObjects:] (self=0x14be778,
> _cmd=0x7ffff7afdf70 <.objc_selector_list+272>, owner=0xe67488,
> topLevelObjects=0x0) at GSNibLoading.m:1926
> #3 0x00007ffff76cff26 in -[NSIBObjectData awakeWithContext:]
> (self=0x14be778, _cmd=0x7ffff7b1a170 <.objc_selector_list+176>,
> context=0xcb09f8) at GSNibLoading.m:1982
> #4 0x00007ffff771028e in -[GSNibLoader
> loadModelData:externalNameTable:withZone:] (self=0xde8158,
> _cmd=0x7ffff7a56260 <.objc_selector_list+224>, data=0xeffb58,
> context=0xcb09f8,
> zone=0x329060bb38 <default_zone>) at GSNibLoader.m:87
> #5 0x00007ffff753f57d in -[NSNib
> instantiateNibWithExternalNameTable:withZone:] (self=0xecf938,
> _cmd=0x7ffff79f7b00 <.objc_selector_list+160>, externalNameTable=0xcb09f8,
> zone=0x329060bb38 <default_zone>) at NSNib.m:153
> #6 0x00007ffff7453949 in +[NSBundle(NSBundleAdditions)
> loadNibFile:externalNameTable:withZone:] (self=0x329057f000
> <_OBJC_CLASS_NSBundle>,
> _cmd=0x7ffff79f7b20 <.objc_selector_list+192>, fileName=0xf03638,
> context=0xcb09f8, zone=0x329060bb38 <default_zone>) at NSBundleAdditions.m:236
> #7 0x00007ffff7454076 in -[NSBundle(NSBundleAdditions)
> loadNibFile:externalNameTable:withZone:] (self=0xd406e8, _cmd=0x7ffff79f7b20
> <.objc_selector_list+192>, fileName=0xeb5498,
> context=0xcb09f8, zone=0x329060bb38 <default_zone>) at
> NSBundleAdditions.m:342
> #8 0x00007ffff7453b5e in +[NSBundle(NSBundleAdditions) loadNibNamed:owner:]
> (self=0x329057f000 <_OBJC_CLASS_NSBundle>, _cmd=0x7ffff79db520
> <.objc_selector_list+688>,
> aNibName=0xeb5498, owner=0xe67488) at NSBundleAdditions.m:277
> #9 0x00007ffff73e2a83 in NSApplicationMain (argc=1, argv=0x7fffffffd330) at
> Functions.m:83
>
> So I set up a memory watch for anObject and then I get this:
>
> Hardware watchpoint 4: *0x1843d58
>
> Old value = -140067648
> New value = -559023410
> 0x00007ffff5b81060 in object_setClass () from /usr/lib64/libobjc.so.4.6
> (gdb) bt
> #0 0x00007ffff5b81060 in object_setClass () from /usr/lib64/libobjc.so.4.6
> #1 0x00007ffff6171b45 in NSDeallocateObject (anObject=0x1843d58) at
> NSObject.m:855
> #2 0x00007ffff61723fc in -[NSObject dealloc] (self=0x1843d58,
> _cmd=0x7ffff7a00880 <.objc_selector_list+2464>) at NSObject.m:1385
> #3 0x00007ffff745ffc1 in -[NSCell dealloc] (self=0x1843d58,
> _cmd=0x7ffff79fc290 <.objc_selector_list+1648>) at NSCell.m:234
> #4 0x00007ffff7455537 in -[NSButtonCell dealloc] (self=0x1843d58,
> _cmd=0x7ffff7a53ec0 <.objc_selector_list+832>) at NSButtonCell.m:185
> #5 0x00007ffff75390b0 in -[NSMenuItemCell dealloc] (self=0x1843d58,
> _cmd=0x7ffff7a6c490 <.objc_selector_list+1856>) at NSMenuItemCell.m:112
> #6 0x00007ffff755cd05 in -[NSPopUpButtonCell dealloc] (self=0x1843d58,
> _cmd=0x7ffff6678370 <.objc_selector_list+560>) at NSPopUpButtonCell.m:158
> #7 0x00007ffff6173739 in -[NSObject release] (self=0x1843d58,
> _cmd=0x7ffff6662ff0 <.objc_selector_list+784>) at NSObject.m:2070
> #8 0x00007ffff61391b4 in GSIArraySetItemAtIndex (array=0x13b6770, item=...,
> index=66) at ../Headers/GNUstepBase/GSIArray.h:531
> #9 0x00007ffff6139911 in -[NSKeyedUnarchiver(Private) _decodeObject:]
> (self=0xdf0dc8, _cmd=0x7ffff6662fe0 <.objc_selector_list+768>, index=66) at
> NSKeyedUnarchiver.m:273
> #10 0x00007ffff613be6d in -[NSKeyedUnarchiver decodeObjectForKey:]
> (self=0xdf0dc8, _cmd=0x7ffff7a16aa0 <.objc_selector_list+80>,
> aKey=0x7ffff7a16940 <.objc_str151>)
> at NSKeyedUnarchiver.m:630
> #11 0x00007ffff74a058e in -[NSControl initWithCoder:] (self=0x16a8d18,
> _cmd=0x7ffff660fdb0 <.objc_selector_list+144>, aDecoder=0xdf0dc8) at
> NSControl.m:1012
> #12 0x000000010000680e in ?? ()
> #13 0x00000000016a8d18 in ?? ()
> #14 0x0000000000e42b90 in ?? ()
> #15 0x00007fffffff4430 in ?? ()
> #16 0x00007ffff76cc5e8 in -[NSClassSwapper
> instantiateRealObject:withClassName:] (self=0xe42b90, _cmd=0x16a8d18,
> coder=0x10000680e, className=0x7fffffff4390)
> at GSNibLoading.m:1416
>
> Frames #12 - #15 are not relevant - basically it's just an -initWithCoder
> override in an NSPopUpButton subclass that just calls [super initWithCoder].
>
> So the target object that was previously set to the NSMenuItem in question is
> now deallocated, so _target in NSMenuItem is now a dangling pointer.
>
> To sum it up, it appears that the whole GUI structure of app's main window is
> first loaded when NSApplicationMain is called, but later on, [NSClassSwapper
> instantiateRealObject] causes some of the parts to be replaced, which leaves
> invalid pointers to previous instances behind.
>
> I'm unable to fix it myself. I'd be grateful for any help.
>
> --
> Luboš Doležel
>
>
> _______________________________________________
> Gnustep-dev mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/gnustep-dev
- NSClassSwapper leaving dangling pointers?, Luboš Doležel, 2013/06/21
- Re: NSClassSwapper leaving dangling pointers?,
Fred Kiefer <=
- Re: NSClassSwapper leaving dangling pointers?, Eric Wasylishen, 2013/06/22
- Message not available
- Re: NSClassSwapper leaving dangling pointers?, Gregory Casamento, 2013/06/23
- Re: NSClassSwapper leaving dangling pointers?, Luboš Doležel, 2013/06/24
- Re: NSClassSwapper leaving dangling pointers?, Luboš Doležel, 2013/06/24
- Re: NSClassSwapper leaving dangling pointers?, Luboš Doležel, 2013/06/24
- Re: NSClassSwapper leaving dangling pointers?, Fred Kiefer, 2013/06/24