XCode Crash Report (Already Symbolicated) Missing Line Numbers - ios

Question

I have a crash report (it is already symbolicated at least I would hope so as I obtained this log from XCode Organizer)
Incident Identifier: F4324555-0916-4E32-82EF-3272917367BB
Beta Identifier: 80811904-A512-48A1-9593-D386703A62F0
Hardware Model: iPhone7,2
Process: SelfieSuperStarz [596]
Path: /private/var/containers/Bundle/Application/BFA0D82B-274B-400B-8F84-52A1D7369C51/SelfieSuperStarz.app/SelfieSuperStarz
Identifier: com.PuckerUp.PuckerUp
Version: 21 (1.31)
Beta: YES
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd [1]
Coalition: com.PuckerUp.PuckerUp [434]
Date/Time: 2017-07-29 20:06:11.7394 -0400
Launch Time: 2017-07-29 19:34:39.7433 -0400
OS Version: iPhone OS 10.3.2 (14F89)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Last Exception Backtrace:
0 CoreFoundation 0x18bebafe0 __exceptionPreprocess + 124 (NSException.m:165)
1 libobjc.A.dylib 0x18a91c538 objc_exception_throw + 56 (objc-exception.mm:521)
2 CoreFoundation 0x18be26eb4 -[__NSArray0 objectAtIndex:] + 108 (CFArray.c:69)
3 SelfieSuperStarz 0x10007b708 specialized _ArrayBuffer._getElementSlowPath(Int) -> AnyObject + 116
4 SelfieSuperStarz 0x10007ea40 specialized Merger.merge(completion : () -> (), assets : [Asset]) -> () + 1444 (Merger.swift:0)
5 SelfieSuperStarz 0x100071f3c specialized AssetView.finish(UIButton) -> () + 520 (Merger.swift:0)
6 SelfieSuperStarz 0x1000712d0 #objc AssetView.finish(UIButton) -> () + 40 (AssetView.swift:0)
7 UIKit 0x192021010 -[UIApplication sendAction:to:from:forEvent:] + 96 (UIApplication.m:4580)
8 UIKit 0x192020f90 -[UIControl sendAction:to:forEvent:] + 80 (UIControl.m:609)
9 UIKit 0x19200b504 -[UIControl _sendActionsForEvents:withEvent:] + 440 (UIControl.m:694)
10 UIKit 0x192020874 -[UIControl touchesEnded:withEvent:] + 576 (UIControl.m:446)
11 UIKit 0x192020390 -[UIWindow _sendTouchesForEvent:] + 2480 (UIWindow.m:2122)
12 UIKit 0x19201b728 -[UIWindow sendEvent:] + 3192 (UIWindow.m:2292)
13 UIKit 0x191fec33c -[UIApplication sendEvent:] + 340 (UIApplication.m:10778)
14 UIKit 0x1927e6014 __dispatchPreprocessedEventFromEventQueue + 2400 (UIEventDispatcher.m:1448)
15 UIKit 0x1927e0770 __handleEventQueue + 4268 (UIEventDispatcher.m:1671)
16 UIKit 0x1927e0b9c __handleHIDEventFetcherDrain + 148 (UIEventDispatcher.m:1706)
17 CoreFoundation 0x18be6942c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24 (CFRunLoop.c:1943)
18 CoreFoundation 0x18be68d9c __CFRunLoopDoSources0 + 540 (CFRunLoop.c:1989)
19 CoreFoundation 0x18be669a8 __CFRunLoopRun + 744 (CFRunLoop.c:2821)
20 CoreFoundation 0x18bd96da4 CFRunLoopRunSpecific + 424 (CFRunLoop.c:3113)
21 GraphicsServices 0x18d800074 GSEventRunModal + 100 (GSEvent.c:2245)
22 UIKit 0x192051058 UIApplicationMain + 208 (UIApplication.m:4089)
23 SelfieSuperStarz 0x10002e990 main + 56 (AppDelegate.swift:16)
24 libdyld.dylib 0x18ada559c start + 4
As you can see it says in my Class Merger at line 0. Which is impossible, as you can probably assume. I am not sure how to interpret what specialized means or why the #objc is there.
3 SelfieSuperStarz 0x10007b708 specialized _ArrayBuffer._getElementSlowPath(Int) -> AnyObject + 116
4 SelfieSuperStarz 0x10007ea40 specialized Merger.merge(completion : () -> (), assets : [Asset]) -> () + 1444 (Merger.swift:0)
5 SelfieSuperStarz 0x100071f3c specialized AssetView.finish(UIButton) -> () + 520 (Merger.swift:0)
6 SelfieSuperStarz 0x1000712d0 #objc AssetView.finish(UIButton) -> () + 40 (AssetView.swift:0)
Just not sure where the error is occurring as the line says Merger:0 and I'm not sure what those headers (specialized/objc) mean if they are telling me anything.
Here is my merge function inside Merger. I use a variety of loops and calculations for opacity and determine things, but I check for nil in locations.
func merge(completion:#escaping () -> Void, assets:[Asset]) {
self.setupAI()
let assets = assets.sorted(by: { $0.layer.zPosition < $1.layer.zPosition })
if let firstAsset = controller.firstAsset {
let mixComposition = AVMutableComposition()
let firstTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
do {
try firstTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, self.controller.realDuration),
of: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0],
at: kCMTimeZero)
} catch _ {
print("Failed to load first track")
}
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
var myTracks:[AVMutableCompositionTrack] = []
var ranges:[ClosedRange<CMTime>] = []
for asset in assets {
let secondTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
secondTrack.preferredTransform = asset.asset.preferredTransform
do {
try secondTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, asset.endTime-asset.beginTime),
of: asset.asset.tracks(withMediaType: AVMediaTypeVideo)[0],
at: CMTime(seconds: CMTimeGetSeconds(asset.beginTime), preferredTimescale: 600000))
} catch _ {
print("Failed to load second track")
}
if(ranges.count == 0) {
ranges.append(asset.beginTime...asset.endTime)
}
else {
var none = true
for range in ranges {
let start = range.contains(asset.beginTime)
let end = range.contains(asset.endTime)
var connection = false
var nothing = false
//This range is completely encompassed (begin and end inside)
if(start && end) {
//Don't add to the rnge
none = false
nothing = true
}
//Begin is in range (right side)
else if(start && !end) {
connection = true
none = false
}
//End is in range (left side)
else if(!start && end) {
connection = true
none = false
}
var connected = false
//It connects 2 different timess
if(connection) {
for range2 in ranges {
if(range != range2) {
if(start && range2.contains(asset.endTime)) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...range2.upperBound)
connected = true
break
}
}
else if(end && range2.contains(asset.beginTime)) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...range2.upperBound)
connected = true
break
}
}
}
}
}
if(!connected && !none && !nothing) {
if(start) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...asset.endTime)
}
}
else if(end) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(asset.beginTime...asset.endTime)
}
}
}
}
if(none) {
ranges.append(asset.beginTime...asset.endTime)
}
}
myTracks.append(secondTrack)
}
for range in ranges {
print(CMTimeGetSeconds(range.lowerBound), CMTimeGetSeconds(range.upperBound))
}
for assets in self.controller.assets {
print(CMTimeGetSeconds(assets.beginTime), CMTimeGetSeconds(assets.endTime))
}
if let loadedAudioAsset = self.controller.audioAsset {
let audioTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: 0)
do {
try audioTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, self.controller.realDuration),
of: loadedAudioAsset.tracks(withMediaType: AVMediaTypeAudio)[0] ,
at: kCMTimeZero)
} catch _ {
print("Failed to load Audio track")
}
}
let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, self.controller.realDuration)
// 2.2
let firstInstruction = self.videoCompositionInstructionForTrack(firstTrack, firstAsset)
var instructions:[AVMutableVideoCompositionLayerInstruction] = []
var counter:Int = 0
for tracks in myTracks {
let secondInstruction = self.videoCompositionInstructionForTrack(tracks, assets[counter].asset, type:true)
let index = myTracks.index(of: tracks)
//This should never be nil, but if it is, it might cause opacity's to go out of whack for that specific track. Only reason I can think of why I am crashing in this method.
if(index != nil) {
if(index! < assets.count-1) {
for i in (counter+1...assets.count-1) {
if(assets[counter].endTime > assets[i].endTime) {
secondInstruction.setOpacity(1.0, at: assets[i].endTime)
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
print("Bigger")
break
}
}
}
if(index! > 0) {
for i in (0...counter).reversed() {
if(assets[counter].endTime < assets[i].endTime) {
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
print("Smaller")
break
}
}
}
if(counter < myTracks.count-1) {
if(assets[counter].layer.zPosition <= assets[counter+1].layer.zPosition) {
secondInstruction.setOpacity(0.0, at: assets[counter+1].beginTime)
}
else {
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
}
}
instructions.append(secondInstruction)
counter += 1
}
}
for range in ranges {
firstInstruction.setOpacity(0.0, at: range.lowerBound)
firstInstruction.setOpacity(1.0, at: range.upperBound)
}
// 2.3
mainInstruction.layerInstructions = [firstInstruction] + instructions
let imageLayer = CALayer()
let image = UIImage(named: "Watermark")
imageLayer.contents = image!.cgImage
let ratio = (firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.width/image!.size.width)/2
let rect = CGRect(x: image!.size.width*ratio, y: 0, width: image!.size.width*ratio, height: image!.size.height*ratio)
imageLayer.frame = rect
imageLayer.backgroundColor = UIColor.clear.cgColor
imageLayer.opacity = 0.75
let videoLayer = CALayer()
videoLayer.frame = CGRect(x: 0, y: 0, width: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.width, height: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.height)
let parentlayer = CALayer()
parentlayer.frame = CGRect(x: 0, y: 0, width: image!.size.width*ratio, height: image!.size.height*ratio)
parentlayer.addSublayer(videoLayer)
parentlayer.addSublayer(imageLayer)
let mainComposition = AVMutableVideoComposition()
mainComposition.instructions = [mainInstruction]
mainComposition.frameDuration = CMTimeMake(1, 30)
mainComposition.renderSize = self.controller.firstAsset!.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize
mainComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentlayer)

Answer 1

It's quite clear that the method "Merger.merge" accesses a non-existing element. The debugger will show you where that is.
I'd guess that some thread is modifying some array behind your back so that an index that was valid at some point becomes invalid. And "for range2 in ranges" when you later on modify "ranges" is asking for trouble.

Answer 2

I am guessing that the problem is caused by line 129, considering the +1444 offset and array access. Have you tried a video without audio, like a video taken without an audio permission? I encountered an out of bound crash by assuming videos taken in my app always had audio tracks. You will be surprised by users what video they feed into your app. I even had a user crashing my app with a flv video, selected from their phone album.
(I am not sure if this will work for Swift)
It is also possible to locate the line in Xcode using the debugger. First, you run the app with the same optimzation setting as the release build. Then you break different lines in the function to check the assembly code.
How to see assembly code in xcode 6. You might need to scroll to the top to double check the function name and the meaning of the offset.
_ArrayBuffer._getElementSlowPath is a class in the private API, indicated by the underscore prefix. You will probably not find any credible and/or official sources about it.
The incompleteness in your crash log is probably caused by bugs/immaturity of Swift (the tools behind it). Welcome to one of the most trended and hyped language. Even in working conditions, Swift gives line 0 for generated code where the code does not correspond to any meaningful parts of the source code. It is not your case though.