[iOS]异常捕捉

UncaughtExceptionHandler.h

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface UncaughtExceptionHandler : NSObject

@end

void UncaughtExceptionHandlerStart(void);

NS_ASSUME_NONNULL_END

UncaughtExceptionHandler.m

#import "UncaughtExceptionHandler.h"
#import <UIKit/UIKit.h>
#import <libkern/OSAtomic.h>
#import <execinfo.h>

NSString * const UncaughtExceptionHandlerSignalExceptionName = @"UncaughtExceptionHandlerSignalExceptionName";
NSString * const UncaughtExceptionHandlerSignalKey = @"UncaughtExceptionHandlerSignalKey";
NSString * const UncaughtExceptionHandlerAddressesKey = @"UncaughtExceptionHandlerAddressesKey";

volatile int32_t UncaughtExceptionCount = 0;
const int32_t UncaughtExceptionMaximum = 10;

const NSInteger UncaughtExceptionHandlerSkipAddressCount = 4;
const NSInteger UncaughtExceptionHandlerReportAddressCount = 5;

@interface UncaughtExceptionHandler ()
{
    BOOL dismissed;
}
@end

@implementation UncaughtExceptionHandler

+ (NSArray *)backtrace
{
    void *callstack[128];
    int frames = backtrace(callstack, 128);
    char **strs = backtrace_symbols(callstack, frames);
    
    NSMutableArray *backtrace = [NSMutableArray arrayWithCapacity:frames];
    int end = UncaughtExceptionHandlerSkipAddressCount + UncaughtExceptionHandlerReportAddressCount;
    
    for (int i = UncaughtExceptionHandlerSkipAddressCount;i < end;i++)
    {
        [backtrace addObject:[NSString stringWithUTF8String:strs[i]]];
    }
    free(strs);
    
    return backtrace;
}

- (void)handleException:(NSException *)exception
{
    NSString *reason = [exception reason];
    NSString *addresses = [[exception userInfo] objectForKey:UncaughtExceptionHandlerAddressesKey];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@""
                                                    message:[NSString stringWithFormat:@"reason:%@\n addresses:%@",reason,addresses]
                                                   delegate:self
                                          cancelButtonTitle:@"退出"
                                          otherButtonTitles:@"继续", nil];
    [alert show];
    
    CFRunLoopRef runLoop = CFRunLoopGetCurrent();
    CFArrayRef allModes = CFRunLoopCopyAllModes(runLoop);
    
    while (!dismissed)
    {
        for (NSString *mode in (__bridge NSArray *)allModes)
        {
            CFRunLoopRunInMode((CFStringRef)mode, 0.001, false);
        }
    }
    
    CFRelease(allModes);
    
    NSSetUncaughtExceptionHandler(NULL);
    signal(SIGABRT, SIG_DFL);
    signal(SIGILL, SIG_DFL);
    signal(SIGSEGV, SIG_DFL);
    signal(SIGFPE, SIG_DFL);
    signal(SIGBUS, SIG_DFL);
    signal(SIGPIPE, SIG_DFL);
    
    if ([[exception name] isEqual:UncaughtExceptionHandlerSignalExceptionName])
    {
        kill(getpid(), [[[exception userInfo] objectForKey:UncaughtExceptionHandlerSignalKey] intValue]);
    }else{
        [exception raise];
    }
}

- (void)alertView:(UIAlertView *)anAlertView clickedButtonAtIndex:(NSInteger)anIndex
{
    if (anIndex == 0)
    {
        dismissed = YES;
    }
}

@end

void HandleException(NSException *exception);
void SignalHandler(int signal);

void UncaughtExceptionHandlerStart(void)
{
    NSSetUncaughtExceptionHandler(&HandleException);
    signal(SIGABRT, SignalHandler);
    signal(SIGILL, SignalHandler);
    signal(SIGSEGV, SignalHandler);
    signal(SIGFPE, SignalHandler);
    signal(SIGBUS, SignalHandler);
    signal(SIGPIPE, SignalHandler);
}

void HandleException(NSException *exception)
{
    int32_t exceptionCount = OSAtomicIncrement32(&UncaughtExceptionCount);
    if (exceptionCount > UncaughtExceptionMaximum)
    {
        return;
    }
    
    NSArray *callStack = [UncaughtExceptionHandler backtrace];
    NSMutableDictionary *userInfo = [NSMutableDictionary dictionaryWithDictionary:[exception userInfo]];
    [userInfo setObject:callStack forKey:UncaughtExceptionHandlerAddressesKey];
    
    [[[UncaughtExceptionHandler alloc] init] performSelectorOnMainThread:@selector(handleException:)
                                                              withObject:[NSException exceptionWithName:[exception name] reason:[exception reason] userInfo:userInfo]
                                                           waitUntilDone:YES];
}

void SignalHandler(int signal)
{
    int32_t exceptionCount = OSAtomicIncrement32(&UncaughtExceptionCount);
    if (exceptionCount > UncaughtExceptionMaximum)
    {
        return;
    }
    
    NSMutableDictionary *userInfo = [NSMutableDictionary dictionaryWithObject:[NSNumber numberWithInt:signal] forKey:UncaughtExceptionHandlerSignalKey];
    
    NSArray *callStack = [UncaughtExceptionHandler backtrace];
    [userInfo setObject:callStack forKey:UncaughtExceptionHandlerAddressesKey];
    
    [[[UncaughtExceptionHandler alloc] init] performSelectorOnMainThread:@selector(handleException:)
                                                              withObject:[NSException exceptionWithName:UncaughtExceptionHandlerSignalExceptionName
                                                                                                 reason:[NSString stringWithFormat:@"Signal %d was raised.",signal]
                                                                                               userInfo:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:signal]
                                                                                                                                    forKey:UncaughtExceptionHandlerSignalKey]]
                                                           waitUntilDone:YES];
}

开启异常捕捉

#import "AppDelegate.h"
#import "UncaughtExceptionHandler.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    
    UncaughtExceptionHandlerStart();
    
    return YES;
}

异常示例

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    NSArray *array = @[@"1"];
    NSLog(@"%@",array[5]);
}

运行效果