我遇到了一个奇怪的崩溃问题，只有在TestFlight ad hoc分发时才会出现。我知道是什么导致了崩溃（一个简单的while循环，见下文），但我不明白为什么模拟器和iPhone或iPad（使用开发配置文件）上没有崩溃。
我一直在分发adhoc版本以跟踪崩溃，但最终放弃了。如何更高效地跟踪这个bug？
以下是TestFlight崩溃报告：
Exception reason
SIGSEGV
Stacktrace
PRIMARY THREAD THREAD 0
0 Meernotes 0x0019649a testflight_backtrace + 158
1 Meernotes 0x001970c4 TFSignalHandler + 244
2 libsystem_c.dylib 0x32d9d7ec _sigtramp + 48
3 libobjc.A.dylib 0x37d34eac _ZN12_GLOBAL__N_119AutoreleasePoolPage3popEPv + 224
4 libobjc.A.dylib 0x37d34eac _ZN12_GLOBAL__N_119AutoreleasePoolPage3popEPv + 224
5 libobjc.A.dylib 0x37d34dc8 _objc_autoreleasePoolPop + 12
6 CoreFoundation 0x358e1cfe _CFAutoreleasePoolPop + 18
7 UIKit 0x333d5c92 _wrapRunLoopWithAutoreleasePoolHandler + 42
8 CoreFoundation 0x35965b1a __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 18
9 CoreFoundation 0x35963d56 __CFRunLoopDoObservers + 258
10 CoreFoundation 0x359640b0 __CFRunLoopRun + 760
11 CoreFoundation 0x358e74a4 CFRunLoopRunSpecific + 300
12 CoreFoundation 0x358e736c CFRunLoopRunInMode + 104
13 GraphicsServices 0x37583438 GSEventRunModal + 136
14 UIKit 0x333f3cd4 UIApplicationMain + 1080
15 Meernotes 0x000850da main (main.m:16)
16 Meernotes 0x0008508f start + 39
这里是触发它的代码（但在模拟器/ iPhone 上运行正常）：
while (textStillFits) {
textToBeKeptBeforeCutting = textToBeKept;
textToBeMovedBeforeCutting = textToBeMoved;
rangeCutOffPosition = [settings determineFirstCutOffRangeOfString:textToBeMoved];
textToBeKeptTemp = [textToBeMoved substringToIndex:rangeCutOffPosition.location];
textToBeMovedTemp = [textToBeMoved substringFromIndex:rangeCutOffPosition.location];
textToBeMoved = textToBeMovedTemp;
textToBeKept = [NSString stringWithFormat:@"%@%@", textToBeKept, textToBeKeptTemp];
NSUInteger l = [settings linesOfText:textToBeKept];
if (l > maxLines) {
textStillFits = NO;
textToBeKept = textToBeKeptBeforeCutting;
textToBeMoved = textToBeMovedBeforeCutting;
// brakes here!
}else {
textStillFits = YES;
}
}
我查看了这个链接，但并没有帮助：ad hoc iphone sigsegv crash
提供更多背景信息，正如@ott提到的，NSNotFound可能会导致此问题：
-(NSRange)determineFirstCutOffRangeOfString:(NSString *)s {
NSRange rangeSpace = [s rangeOfString:@" " options:NSCaseInsensitiveSearch];
NSRange rangeReturn = [s rangeOfString:@"\n" options:NSCaseInsensitiveSearch];
if (rangeSpace.location == NSNotFound && rangeReturn.location == NSNotFound) {
rangeSpace = NSMakeRange(1, 0); // don't take 0,0 as this will lead to endless loop
rangeReturn = NSMakeRange(1, 0);
NSLog(@"NEITHER SPACE NOR RETURN FOUND");
}
NSRange rangeCutOffPosition = NSMakeRange(0, 0);
if (rangeSpace.location < rangeReturn.location) {
// i.e. if the space char is the lowest char where you can cut off
rangeCutOffPosition = NSMakeRange(rangeSpace.location+1,0); // +1, i.e. always cut off AFTER the space
} else {
// i.e. if the return char is the lowest char where you can cut off
rangeCutOffPosition = NSMakeRange(rangeReturn.location+1,0); // +1, i.e. always cut off AFTER the return
}
return rangeCutOffPosition;
}
rangeCutOffPosition会变成NotFound吗？设备通常更加挑剔，而模拟器则只是忽略它。你能插入一些 NSLog() 来查看发生了什么，或者逐步执行它吗？ - ott--