iphone获取crash信息和堆栈信息

 在app发布到商店之后，用户的crash报告怎么才能收集回来？ 根据苹果官方的文档，当设备连接上itunes后，crash报告会自动同步至pc，但是用户可能很少这么做，即使有，可能用户也找不到，用户找到了，也可能不想麻烦再传给你。这时候，我们改怎么办？

         其实，我们可以自己做一个错误收集模块。不过这个收集要分成两个部分：1、NSException 2、非NSException致命错误（如提前释放内存、内存超最高限制）

         第一部分，NSException的收集。采用自定义exception处理函数，替换系统处理函数来取得exception发生时的具体错误信息、堆栈状态。

自定义exception处理函数：

void exceptionHandler(NSException *exception) {
    NSLog(@"Exception throw: %@", exception);
    NSLog(@"Stack Trace:\r\n%@", [exception callStackSymbols]);
    //NSLog(@"Stack Trace:\r\n%@", GTMStackTraceFromException(exception));
}

void exceptionHandler(NSException *exception) {
    NSLog(@"Exception throw: %@", exception);
    NSLog(@"Stack Trace:\r\n%@", [exception callStackSymbols]);
	//NSLog(@"Stack Trace:\r\n%@", GTMStackTraceFromException(exception));
}

然后调用

NSSetUncaughtExceptionHandler(&exceptionHandler);

NSSetUncaughtExceptionHandler(&exceptionHandler);

来替换系统得exception处理函数.

第二部分：signal的处理

自定义系统收到signal时得处理函数：

void stacktrace(int sig, siginfo_t *info, void *context)
{

    NSMutableString * mstr = [[NSMutableString alloc] initWithCapacity:0];
    [mstr appendString:@"Stack:\n"];

    void* callstack[128];
    int i, frameCount = backtrace(callstack, 128);
    char** strs = backtrace_symbols(callstack, frameCount);
    for (i = 0; i < frameCount; ++i) {
        [mstr appendFormat:@"%s\n", strs[i]];
    }

    NSLog(@"Stack Trace:\r\n%@", mstr);
}

void stacktrace(int sig, siginfo_t *info, void *context)
{
    
    NSMutableString * mstr = [[NSMutableString alloc] initWithCapacity:0];
    [mstr appendString:@"Stack:\n"];
    
    void* callstack[128];
    int i, frameCount = backtrace(callstack, 128);
    char** strs = backtrace_symbols(callstack, frameCount);
    for (i = 0; i < frameCount; ++i) {
        [mstr appendFormat:@"%s\n", strs[i]];
    }
     
    NSLog(@"Stack Trace:\r\n%@", mstr);
}

注册系统要监测的signal:

struct sigaction mySigAction;
mySigAction.sa_sigaction = stacktrace;
mySigAction.sa_flags = SA_SIGINFO;

sigemptyset(&mySigAction.sa_mask);
sigaction(SIGQUIT, &mySigAction, NULL);
sigaction(SIGILL , &mySigAction, NULL);
sigaction(SIGTRAP, &mySigAction, NULL);
sigaction(SIGABRT, &mySigAction, NULL);
sigaction(SIGEMT , &mySigAction, NULL);
sigaction(SIGFPE , &mySigAction, NULL);
sigaction(SIGBUS , &mySigAction, NULL);
sigaction(SIGSEGV, &mySigAction, NULL);
sigaction(SIGSYS , &mySigAction, NULL);
sigaction(SIGPIPE, &mySigAction, NULL);
sigaction(SIGALRM, &mySigAction, NULL);
sigaction(SIGXCPU, &mySigAction, NULL);
sigaction(SIGXFSZ, &mySigAction, NULL);

    struct sigaction mySigAction;
    mySigAction.sa_sigaction = stacktrace;
    mySigAction.sa_flags = SA_SIGINFO;
    
    sigemptyset(&mySigAction.sa_mask);
    sigaction(SIGQUIT, &mySigAction, NULL);
    sigaction(SIGILL , &mySigAction, NULL);
    sigaction(SIGTRAP, &mySigAction, NULL);
    sigaction(SIGABRT, &mySigAction, NULL);
    sigaction(SIGEMT , &mySigAction, NULL);
    sigaction(SIGFPE , &mySigAction, NULL);
    sigaction(SIGBUS , &mySigAction, NULL);
    sigaction(SIGSEGV, &mySigAction, NULL);
    sigaction(SIGSYS , &mySigAction, NULL);
    sigaction(SIGPIPE, &mySigAction, NULL);
    sigaction(SIGALRM, &mySigAction, NULL);
    sigaction(SIGXCPU, &mySigAction, NULL);
    sigaction(SIGXFSZ, &mySigAction, NULL);

另外，还有一种办法就是将console中得错误重定向，写入文本。

1. 设置一个开关，用来清空日志文件内容，并切换输出位置；

- (BOOL)deleteLogFile {

    [self finishLog];
    BOOL success = [[NSFileManager defaultManager] removeItemAtPath:[self loggingPath] error:nil];
    [self startLog];
    return success;

}

- (BOOL)deleteLogFile {

    [self finishLog];
    BOOL success = [[NSFileManager defaultManager] removeItemAtPath:[self loggingPath] error:nil];
    [self startLog];
    return success;

}

当我们调用上面的deleteLogFile后，就会清空之前的日志，并设置新的输出。

- (void)finishLog {

    fflush(stderr);
    dup2(dup(STDERR_FILENO), STDERR_FILENO);
    close(dup(STDERR_FILENO));

}

- (NSString*)loggingPath {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *logPath = [documentsDirectory stringByAppendingPathComponent:@"console.log"];
    return logPath;

}

- (void)startLog {
   freopen([[self loggingPath] cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
}

- (void)finishLog {

    fflush(stderr);
    dup2(dup(STDERR_FILENO), STDERR_FILENO);
    close(dup(STDERR_FILENO));

}

- (NSString*)loggingPath {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *logPath = [documentsDirectory stringByAppendingPathComponent:@"console.log"];
    return logPath;

}

- (void)startLog {
   freopen([[self loggingPath] cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
}

2. 当日志取得之后，可以通过下面的方式发送邮件给开发者

- (void)sendLogByMail {

    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;
    [picker setSubject:[NSString stringWithFormat:@"%@ - Log", [self appName]]];
    NSString *message = [NSString stringWithContentsOfFile:[self loggingPath] encoding:NSUTF8StringEncoding error:nil];
    [picker setMessageBody:message isHTML:NO];
    [self.navigationController presentModalViewController:picker animated:YES];
    [picker release];

}

- (void)sendLogByMail {

    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;
    [picker setSubject:[NSString stringWithFormat:@"%@ - Log", [self appName]]];
    NSString *message = [NSString stringWithContentsOfFile:[self loggingPath] encoding:NSUTF8StringEncoding error:nil];
    [picker setMessageBody:message isHTML:NO];
    [self.navigationController presentModalViewController:picker animated:YES];
    [picker release];

}

最后总结：

因iOS sdk中没有<Foundation/NSDebug.h>, 不能使用backtrace_symbols等函数，在网上有一个方便得工具库（google-toolbox-for-mac），其中有专门处理stacktrace的GTMStackTrace.

综合上面的代码如下：

//
//  main.m
//  Taonan
//
//  Created by zeng songgen on 11-3-11.
//  Copyright 2011 none. All rights reserved.
//

#import <UIKit/UIKit.h>
#include <signal.h>
#import "config.h"

#import "GTMStackTrace.h"

void exceptionHandler(NSException *exception) {
    NSLog(@"Exception throw: %@", exception);
    NSLog(@"Stack Trace:\r\n%@", [exception callStackSymbols]);
    //NSLog(@"Stack Trace:\r\n%@", GTMStackTraceFromException(exception));
}

void stacktrace(int sig, siginfo_t *info, void *context)
{
    /*
    NSMutableString * mstr = [[NSMutableString alloc] initWithCapacity:0];
    [mstr appendString:@"Stack:\n"];

    void* callstack[128];
    int i, frameCount = backtrace(callstack, 128);
    char** strs = backtrace_symbols(callstack, frameCount);
    for (i = 0; i < frameCount; ++i) {
        [mstr appendFormat:@"%s\n", strs[i]];
    }
    NSLog(@"Stack Trace:\r\n%@", mstr);
     */
    NSLog(@"Stack Trace:\r\n%@", GTMStackTrace());
}

int main(int argc, char *argv[]) {
    NSSetUncaughtExceptionHandler(&exceptionHandler);

    struct sigaction mySigAction;
    mySigAction.sa_sigaction = stacktrace;
    mySigAction.sa_flags = SA_SIGINFO;

    sigemptyset(&mySigAction.sa_mask);
    sigaction(SIGQUIT, &mySigAction, NULL);
    sigaction(SIGILL , &mySigAction, NULL);
    sigaction(SIGTRAP, &mySigAction, NULL);
    sigaction(SIGABRT, &mySigAction, NULL);
    sigaction(SIGEMT , &mySigAction, NULL);
    sigaction(SIGFPE , &mySigAction, NULL);
    sigaction(SIGBUS , &mySigAction, NULL);
    sigaction(SIGSEGV, &mySigAction, NULL);
    sigaction(SIGSYS , &mySigAction, NULL);
    sigaction(SIGPIPE, &mySigAction, NULL);
    sigaction(SIGALRM, &mySigAction, NULL);
    sigaction(SIGXCPU, &mySigAction, NULL);
    sigaction(SIGXFSZ, &mySigAction, NULL);

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, nil);
    [pool release];
    return retVal;
}