iOS Crash閃退信息捕獲工具類

        IOS SDK中提供了一個現成的函數 NSSetUncaughtExceptionHandler 用來做異常處理，但功能非常有限，而引起崩潰的大多數原因如：內存訪問錯誤，重復釋放等錯誤捕獲不到，因為這些異常拋出的是Signal，所以必須要專門做Signal處理。工具類的實現源碼如下：

頭文件

#import <Foundation/Foundation.h>

extern NSString *const UncaughtExceptionHandlerSignalKey;
extern NSString *const SingalExceptionHandlerAddressesKey;
extern NSString *const ExceptionHandlerAddressesKey;

@interface ExceptionHandler : NSObject
+ (void)installExceptionHandler;
+ (NSArray *)backtrace;
@end

#import "ExceptionHandler.h"
#include <libkern/OSAtomic.h>
#include <execinfo.h>

NSString *const UncaughtExceptionHandlerSignalKey = @"UncaughtExceptionHandlerSignalKey";
NSString *const SingalExceptionHandlerAddressesKey = @"SingalExceptionHandlerAddressesKey";
NSString *const ExceptionHandlerAddressesKey = @"ExceptionHandlerAddressesKey";

const int32_t _uncaughtExceptionMaximum = 20;

// 系統信號截獲處理方法
void signalHandler(int signal);

// 異常截獲處理方法
void exceptionHandler(NSException *exception);

void signalHandler(int signal)
{
    volatile int32_t _uncaughtExceptionCount = 0;
    int32_t exceptionCount = OSAtomicIncrement32(&_uncaughtExceptionCount);

    // 如果太多不用處理
    if (exceptionCount > _uncaughtExceptionMaximum) {
        return;
    }

    // 獲取信息
    NSMutableDictionary *userInfo = [NSMutableDictionary dictionaryWithObject:[NSNumber numberWithInt:signal] forKey:UncaughtExceptionHandlerSignalKey];
    NSArray *callStack = [ExceptionHandler backtrace];
    [userInfo  setObject:callStack  forKey:SingalExceptionHandlerAddressesKey];

    // 現在就可以保存信息到本地［］

}

void exceptionHandler(NSException *exception)
{
    volatile int32_t _uncaughtExceptionCount = 0;
    int32_t exceptionCount = OSAtomicIncrement32(&_uncaughtExceptionCount);

    // 如果太多不用處理
    if (exceptionCount > _uncaughtExceptionMaximum) {
        return;
    }

    NSArray *callStack = [ExceptionHandler backtrace];
    NSMutableDictionary *userInfo =[NSMutableDictionary dictionaryWithDictionary:[exception userInfo]];
    [userInfo setObject:callStack forKey:ExceptionHandlerAddressesKey];
    NSLog(@"Exception Invoked: %@", userInfo);

    // 現在就可以保存信息到本地［］


}

@implementation ExceptionHandler

//獲取調用堆棧
+ (NSArray *)backtrace
{
    void* callstack[128];
    int frames = backtrace(callstack, 128);
    char **strs = backtrace_symbols(callstack,frames);

    NSMutableArray *backtrace = [NSMutableArray arrayWithCapacity:frames];
    for (int i=0;i<frames;i++) {
        [backtrace addObject:[NSString stringWithUTF8String:strs[i]]];
    }
    free(strs);
    return backtrace;
}


// 注冊崩潰攔截
+ (void)installExceptionHandler
{
    NSSetUncaughtExceptionHandler(&exceptionHandler);
    signal(SIGHUP, signalHandler);
    signal(SIGINT, signalHandler);
    signal(SIGQUIT, signalHandler);
    signal(SIGABRT, signalHandler);
    signal(SIGILL, signalHandler);
    signal(SIGSEGV, signalHandler);
    signal(SIGFPE, signalHandler);
    signal(SIGBUS, signalHandler);
    signal(SIGPIPE, signalHandler);
}

@end