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iOS Crash Collection and Analysis with PLCrashReporter使用 PLCrashReporter 进行 iOS 崩溃收集与分析

2015-09-09 · Debugging & reverse engineering

Translated from Chinese — .

On this page

Introduction
Directly Calling System Functions to Get the Stack Info at Crash Time
Using PLCrashReporter
Conclusion
Other Open-Source Projects
Reference Articles

Introduction

After an App goes live, if it crashes, are you just supposed to stare helplessly? You can’t take the user’s phone and import the crash log via Organizer, so you need to automatically collect crash logs when the program crashes, and upload the crash logs to the server the next time the program launches.

The crash log should be associated with a particular revision of the code (if using svn). (Usually with continuous integration via Jenkins, you can indirectly associate it to the code through Jenkins’s BuildNumber.)
The dSYM symbol file for the corresponding version. (Can be configured to generate at link time.)

Directly Calling System Functions to Get the Stack Info at Crash Time

This approach can obtain simple crash information, but cannot work with the dSYM file to pinpoint the specific line of code. Also, the kinds of crash types it can capture are limited; obtaining more information requires more work (the open-source plcrashreporter below has already done this).

signal for capturing error signals
NSSetUncaughtExceptionHandler for uncaught OC exceptions

static int s_fatal_signals[] = {
    SIGABRT,
    SIGBUS,
    SIGFPE,
    SIGILL,
    SIGSEGV,
    SIGTRAP,
    SIGTERM,
    SIGKILL,
};


static int s_fatal_signal_num = sizeof(s_fatal_signals) / sizeof(s_fatal_signals[0]);

void UncaughtExceptionHandler(NSException *exception) {
    NSArray *arr = [exception callStackSymbols];//得到当前调用栈信息
    NSString *reason = [exception reason];//非常重要，就是崩溃的原因
    NSString *name = [exception name];//异常类型
}

void SignalHandler(int code)
{
    NSLog(@"signal handler = %d",code);
}

void InitCrashReport()
{
    // 1 linux错误信号捕获
    for (int i = 0; i < s_fatal_signal_num; ++i) {
        signal(s_fatal_signals[i], SignalHandler);
    }
    
    // 2 objective-c未捕获异常的捕获
    NSSetUncaughtExceptionHandler(&UncaughtExceptionHandler);
}
int main(int argc, char * argv[]) {
    @autoreleasepool {
        InitCrashReport();

        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}

Using PLCrashReporter

Official Site

https://www.plcrashreporter.org/

Installation

Can be installed via CocoaPods:

pod 'PLCrashReporter', '~> 1.2'

Example

//
 // Called to handle a pending crash report.
 //
- (void) handleCrashReport {
     PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter];
     NSData *crashData;
     NSError *error;

     // Try loading the crash report
     crashData = [crashReporter loadPendingCrashReportDataAndReturnError: &error];
     if (crashData == nil) {
         NSLog(@"Could not load crash report: %@", error);
         [crashReporter purgePendingCrashReport];
         return;
     }
    
    [crashData writeToFile:[self crashDataPath] atomically:YES];

     // We could send the report from here, but we'll just print out
     // some debugging info instead
     PLCrashReport *report = [[PLCrashReport alloc] initWithData: crashData error: &error];
     if (report == nil) {
         NSLog(@"Could not parse crash report");
         [crashReporter purgePendingCrashReport];
         return;
     }

     NSLog(@"Crashed on %@", report.systemInfo.timestamp);
     NSLog(@"Crashed with signal %@ (code %@, address=0x%" PRIx64 ")", report.signalInfo.name,
           report.signalInfo.code, report.signalInfo.address);
    
    NSString *humanText = [PLCrashReportTextFormatter stringValueForCrashReport:report withTextFormat:PLCrashReportTextFormatiOS];
    
    [self WriteContent:humanText];
    
     // Purge the report
     [crashReporter purgePendingCrashReport];
    
     return;
 }

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter];
    NSError *error;
    
    // Check if we previously crashed
    if ([crashReporter hasPendingCrashReport])
        [self handleCrashReport];

    // Enable the Crash Reporter
    if (![crashReporter enableCrashReporterAndReturnError: &error])
        NSLog(@"Warning: Could not enable crash reporter: %@", error);
    
    return YES;
}

Working with the dSYM File

     crashData = [crashReporter loadPendingCrashReportDataAndReturnError: &error];

The returned NSData is in plcrashreporter’s private format; it can be converted into a standard Apple crash log via the officially provided plcrashutil tool.

For example:

1- Open the example project, run with Command + R, then quit the program.

2- Run plcrashreporter2 separately through the simulator. Tap Exception to trigger a crash.

3- Open the App again, and the App will automatically record the crash log as d.plcrash.

4- Open the Xcode menu, Window -> Projects, click the little arrow to the right of Derived Data, and go into /Users/everettjf/Library/Developer/Xcode/DerivedData/plcrashreportertest2-aoaojvrcqilsxqcarfmgulsddpvc/

5- Then manually go into the directory Build/Products/Debug-iphonesimulator, which holds the plcrashreportertest2.app.dSYM and plcrashreportertest2.app files. (For convenience of demonstration) copy these two files to the Desktop. (Note: when archiving for product release, the corresponding dSYM file is also generated, in another directory. These directories are actually all configurable; some tools, e.g. the gym in shenzhen or fastlane, automatically package the dSYM folder into a zip.) (Note again: dSYM is a folder.)

6- Copy out the d.plcrash file. On my machine it’s at this path /Users/everettjf/Library/Developer/CoreSimulator/Devices/319973DD-0853-494A-8688-DC73E733019D/data/Containers/Data/Application/D85F4320-1826-4EDD-8167-1197BFA5ACBA/Documents/ (you can look at the terminal output) (the last folder differs for different simulators) — also copy it to the Desktop.

7- Convert to Apple log format

$ plcrashutil convert --format=ios d.plcrash > apple.log

8- dwarfdump to view the uuid

$ dwarfdump --uuid plcrashreportertest2.app/plcrashreportertest2
UUID: B1020E4A-07DD-35E4-B3F0-71E3B7CA49BB (x86_64) plcrashreportertest2.app/plcrashreportertest2
$ dwarfdump --uuid plcrashreportertest2.app.dSYM
UUID: B1020E4A-07DD-35E4-B3F0-71E3B7CA49BB (x86_64) plcrashreportertest2.app.dSYM/Contents/Resources/DWARF/plcrashreportertest2

9- View the crashlog’s uuid

Binary Images:
       0x107d23000 -        0x107d4efff +plcrashreportertest2 x86_64  <b1020e4a07dd35e4b3f071e3b7ca49bb> ......

10- If the three uuids match, you can analyze.

11- The symbolicatecrash tool

    - 干脆把这个藏得这么深得工具也复制一份出来。

Xcode7.2 及以前：
/Applications/Xcode.app/Contents/SharedFrameworks/DTDeviceKitBase.framework/Versions/A/Resources/symbolicatecrash

Xcode 7.3
/Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/symbolicatecrash

cd /Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/
cp symbolicatecrash ~/Desktop
    - 设置DEVELOPER_DIR。
export DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer
    - 导出。
$ ./symbolicatecrash apple.log plcrashreportertest2.app.dSYM > result.log

12- Finally, atos, where 0x107d23000 can be seen after Binary Images:. 0x0000000107d24c3e is in the Last Exception Backtrace.

$ xcrun atos -o plcrashreportertest2.app/plcrashreportertest2 -l 0x107d23000
0x0000000107d24c3e
-[ViewController exceptionTouchUp:] (in plcrashreportertest2) (ViewController.m:84)

Conclusion

This last atos still requires manually entering things one by one, which is rather troublesome. I don’t know whether there’s a killer tool on Mac or iOS like windbg on Windows; I’ll add it later once I find out.

Other Open-Source Projects

KSCrash https://github.com/kstenerud/KSCrash

Reference Articles

http://www.jamiegrove.com/software/fixing-bugs-using-os-x-crash-logs-and-atos-to-symbolicate-and-find-line-numbers

文章目录

简介
直接调用系统函数获取崩溃时的栈信息
使用PLCrashReporter
- 官网
- 安装
- 示例
- 配合dSYM文件
结语
其他开源项目
参考文章

简介

App上线后，如果崩溃，难道只能干瞪眼？不可能拿到用户的手机来通过Organizer导入崩溃日志，因此需要在程序崩溃时自动收集崩溃的日志，并在程序再次启动时，将崩溃日志上传到服务器。

崩溃日志要关联到某一个revision的代码（如果是svn）。（一般使用持续集成Jenkins，可以通过Jenkins的BuildNumber间接关联到代码）。
对应版本的dSYM符号文件。（链接时可配置生成）

直接调用系统函数获取崩溃时的栈信息

这种方式，能获取到简单的崩溃信息，但无法配合dSYM文件，定位到具体的哪行代码。且能获取到的崩溃类型种类有限，如果要获取更多的信息还需要更多的工作（下文中的开源的plcrashreporter已经做好了）。

signal 进行错误信号的捕获
NSSetUncaughtExceptionHandler 未捕获的OC异常

static int s_fatal_signals[] = {
    SIGABRT,
    SIGBUS,
    SIGFPE,
    SIGILL,
    SIGSEGV,
    SIGTRAP,
    SIGTERM,
    SIGKILL,
};


static int s_fatal_signal_num = sizeof(s_fatal_signals) / sizeof(s_fatal_signals[0]);

void UncaughtExceptionHandler(NSException *exception) {
    NSArray *arr = [exception callStackSymbols];//得到当前调用栈信息
    NSString *reason = [exception reason];//非常重要，就是崩溃的原因
    NSString *name = [exception name];//异常类型
}

void SignalHandler(int code)
{
    NSLog(@"signal handler = %d",code);
}

void InitCrashReport()
{
    // 1 linux错误信号捕获
    for (int i = 0; i < s_fatal_signal_num; ++i) {
        signal(s_fatal_signals[i], SignalHandler);
    }
    
    // 2 objective-c未捕获异常的捕获
    NSSetUncaughtExceptionHandler(&UncaughtExceptionHandler);
}
int main(int argc, char * argv[]) {
    @autoreleasepool {
        InitCrashReport();

        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}

使用PLCrashReporter

官网

https://www.plcrashreporter.org/

安装

可使用CocoaPods安装：

pod 'PLCrashReporter', '~> 1.2'

示例

//
 // Called to handle a pending crash report.
 //
- (void) handleCrashReport {
     PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter];
     NSData *crashData;
     NSError *error;

     // Try loading the crash report
     crashData = [crashReporter loadPendingCrashReportDataAndReturnError: &error];
     if (crashData == nil) {
         NSLog(@"Could not load crash report: %@", error);
         [crashReporter purgePendingCrashReport];
         return;
     }
    
    [crashData writeToFile:[self crashDataPath] atomically:YES];

     // We could send the report from here, but we'll just print out
     // some debugging info instead
     PLCrashReport *report = [[PLCrashReport alloc] initWithData: crashData error: &error];
     if (report == nil) {
         NSLog(@"Could not parse crash report");
         [crashReporter purgePendingCrashReport];
         return;
     }

     NSLog(@"Crashed on %@", report.systemInfo.timestamp);
     NSLog(@"Crashed with signal %@ (code %@, address=0x%" PRIx64 ")", report.signalInfo.name,
           report.signalInfo.code, report.signalInfo.address);
    
    NSString *humanText = [PLCrashReportTextFormatter stringValueForCrashReport:report withTextFormat:PLCrashReportTextFormatiOS];
    
    [self WriteContent:humanText];
    
     // Purge the report
     [crashReporter purgePendingCrashReport];
    
     return;
 }

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter];
    NSError *error;
    
    // Check if we previously crashed
    if ([crashReporter hasPendingCrashReport])
        [self handleCrashReport];

    // Enable the Crash Reporter
    if (![crashReporter enableCrashReporterAndReturnError: &error])
        NSLog(@"Warning: Could not enable crash reporter: %@", error);
    
    return YES;
}

配合dSYM文件

     crashData = [crashReporter loadPendingCrashReportDataAndReturnError: &error];

返回的NSData是plcrashreporter私有的格式，通过官方提供的plcrashutil工具可转换为标准的苹果崩溃日志。

例如：

1- 打开示例工程，Command + R 运行，然后退出程序。

2- 单独通过模拟器运行plcrashreporter2。点击 Exception 触发崩溃。

3- 再次打开App，App将自动把崩溃日志记录为d.plcrash。

4- 打开Xcode菜单，Window -> Projects ，点击Derived Data右侧的小箭头，进入 /Users/everettjf/Library/Developer/Xcode/DerivedData/plcrashreportertest2-aoaojvrcqilsxqcarfmgulsddpvc/

5- 再手动进入目录 Build/Products/Debug-iphonesimulator，这里保存着 plcrashreportertest2.app.dSYM 和 plcrashreportertest2.app 文件，（为方便演示）将这两个文件复制到桌面。（注：产品发布的Archive时，也会生成对应的dSYM文件，会在另一个目录。这些目录其实都是可以配置的，一些工具例如：shenzhen或fastlane中的gym都会自动将dSYM文件夹打包成zip。）(再注：dSYM是个文件夹）

6- 复制出d.plcrash文件。我机器上在这个路径 /Users/everettjf/Library/Developer/CoreSimulator/Devices/319973DD-0853-494A-8688-DC73E733019D/data/Containers/Data/Application/D85F4320-1826-4EDD-8167-1197BFA5ACBA/Documents/ （可以看终端的输出）（不同模拟器最后的文件夹不同）也复制到桌面。

7- 转换为苹果日志格式

$ plcrashutil convert --format=ios d.plcrash > apple.log

8- dwarfdump 查看uuid

$ dwarfdump --uuid plcrashreportertest2.app/plcrashreportertest2
UUID: B1020E4A-07DD-35E4-B3F0-71E3B7CA49BB (x86_64) plcrashreportertest2.app/plcrashreportertest2
$ dwarfdump --uuid plcrashreportertest2.app.dSYM
UUID: B1020E4A-07DD-35E4-B3F0-71E3B7CA49BB (x86_64) plcrashreportertest2.app.dSYM/Contents/Resources/DWARF/plcrashreportertest2

9- 查看crashlog的uuid

Binary Images:
       0x107d23000 -        0x107d4efff +plcrashreportertest2 x86_64  <b1020e4a07dd35e4b3f071e3b7ca49bb> ......

10- 三个uuid一致，则可以分析了。

11- symbolicatecrash工具

    - 干脆把这个藏得这么深得工具也复制一份出来。

Xcode7.2 及以前：
/Applications/Xcode.app/Contents/SharedFrameworks/DTDeviceKitBase.framework/Versions/A/Resources/symbolicatecrash

Xcode 7.3
/Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/symbolicatecrash

cd /Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/
cp symbolicatecrash ~/Desktop
    - 设置DEVELOPER_DIR。
export DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer
    - 导出。
$ ./symbolicatecrash apple.log plcrashreportertest2.app.dSYM > result.log

12- 最后，atos，其中0x107d23000可在 Binary Images:后看到。0x0000000107d24c3e是Last Exception Backtrace 中。

$ xcrun atos -o plcrashreportertest2.app/plcrashreportertest2 -l 0x107d23000
0x0000000107d24c3e
-[ViewController exceptionTouchUp:] (in plcrashreportertest2) (ViewController.m:84)

结语

最后这个atos还需要手动逐个输入，较麻烦。不知道Mac或iOS下有没有像windows下windbg一样的神器，以后知道了补上。

其他开源项目

KSCrash https://github.com/kstenerud/KSCrash

参考文章

http://www.jamiegrove.com/software/fixing-bugs-using-os-x-crash-logs-and-atos-to-symbolicate-and-find-line-numbers