Android 符号表

一、什么是符号表

在Android平台上，符号表用于将混淆过的代码进行还原，其中Java代码的符号化文件是mapping文件，C/C++代码的符号化文件是SO文件。

1. mapping文件

mapping文件可用于对混淆后的Java Crash堆栈进行还原。

• 原始堆栈

  java.lang.NullPointerException
  	at com.aliyun.emas.android.apm.CrashActivity$o.a(CrashActivity.java:1)
  	at com.aliyun.emas.android.apm.CrashActivity$f.onClick(CrashActivity.java:1)
  	at android.view.View.performClick(View.java:7751)
  	at android.view.View.performClickInternal(View.java:7724)
  	at android.view.View.access$3700(View.java:858)
  	at android.view.View$PerformClick.run(View.java:29336)
  	at android.os.Handler.handleCallback(Handler.java:938)
  	at android.os.Handler.dispatchMessage(Handler.java:99)
  	at android.os.Looper.loopOnce(Looper.java:211)
  	at android.os.Looper.loop(Looper.java:300)
  	at android.app.ActivityThread.main(ActivityThread.java:8285)
  	at java.lang.reflect.Method.invoke(Native Method)
  	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:576)
  	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1074)

• 还原堆栈

  java.lang.NullPointerException
  	at com.aliyun.emas.android.apm.CrashActivity$JavaCrash.throwException(CrashActivity.java:281)
  	at com.aliyun.emas.android.apm.CrashActivity$1.onClick(CrashActivity.java:54)
  	at android.view.View.performClick(View.java:7778)
  	at android.view.View.performClickInternal(View.java:7755)
  	at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
  	at android.view.View$PerformClick.run(View.java:30769)
  	at android.os.Handler.handleCallback(Handler.java:1013)
  	at android.os.Handler.dispatchMessage(Handler.java:101)
  	at android.os.Looper.loopOnce(Looper.java:226)
  	at android.os.Looper.loop(Looper.java:328)
  	at android.app.ActivityThread.main(ActivityThread.java:9179)
  	at java.lang.reflect.Method.invoke(Native Method)
  	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:594)
  	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
  Back traces end.

2. SO符号表

SO符号表是用来存储源代码中符号信息的数据结构，符号表元素如下所示：

<起始地址> <结束地址> <函数> [<文件名：行号>]

SO符号表可用于对Native Crash堆栈进行还原。

• 原始堆栈

  #00 pc 000000000000f224  /data/app/~~z7k3Yi_OI3CSgGIlRwLTAA==/com.aliyun.ha.test_8-kjF3YBAA72Ed6Q0gg9U7fQ==/lib/arm64/libnativecrash.so (_Z4testv+20)
  #01 pc 000000000000f200  /data/app/~~z7k3Yi_OI3CSgGIlRwLTAA==/com.aliyun.ha.test_8-kjF3YBAA72Ed6Q0gg9U7fQ==/lib/arm64/libnativecrash.so (Java_com_example_nativecrash_NativeLib_mockSigSegv+20)
  #02 pc 0000000000022244  /apex/com.android.art/lib64/libart.so (art_quick_generic_jni_trampoline+148)
  #03 pc 0000000000018964  /apex/com.android.art/lib64/libart.so (art_quick_invoke_stub+548)
  #04 pc 00000000000845a8  /apex/com.android.art/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+188)
  #05 pc 00000000001fd680  /apex/com.android.art/lib64/libart.so (_ZN3art11interpreter34ArtInterpreterToCompiledCodeBridgeEPNS_6ThreadEPNS_9ArtMethodEPNS_11ShadowFrameEtPNS_6JValueE+400)
  #06 pc 00000000001f84f4  /apex/com.android.art/lib64/libart.so (_ZN3art11interpreter6DoCallILb0ELb0EEEbPNS_9ArtMethodEPNS_6ThreadERNS_11ShadowFrameEPKNS_11InstructionEtPNS_6JValueE+804)
  #07 pc 0000000000595d50  /apex/com.android.art/lib64/libart.so (MterpInvokeVirtual+1168)
  #08 pc 0000000000003814  /apex/com.android.art/lib64/libart.so (mterp_op_invoke_virtual+20)

• 还原堆栈

  #00 pc 0xf224 libnativecrash.so (/Users/liubaowen/projects/temp/emas-android-appmonitor-demo/nativecrash/src/main/cpp/nativecrash.cpptest()
  #01 pc 0xf200 libnativecrash.so (/Users/liubaowen/projects/temp/emas-android-appmonitor-demo/nativecrash/src/main/cpp/nativecrash.cppJava_com_example_nativecrash_NativeLib_mockSigSegv+line:17)
  #02 pc 0x22244 libart.so (art_quick_generic_jni_trampoline+148)
  #03 pc 0x18964 libart.so (art_quick_invoke_stub+548)
  #04 pc 0x845a8 libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+188)
  #05 pc 0x1fd680 libart.so (_ZN3art11interpreter34ArtInterpreterToCompiledCodeBridgeEPNS_6ThreadEPNS_9ArtMethodEPNS_11ShadowFrameEtPNS_6JValueE+400)
  #06 pc 0x1f84f4 libart.so (_ZN3art11interpreter6DoCallILb0ELb0EEEbPNS_9ArtMethodEPNS_6ThreadERNS_11ShadowFrameEPKNS_11InstructionEtPNS_6JValueE+804)
  #07 pc 0x595d50 libart.so (MterpInvokeVirtual+1168)
  #08 pc 0x3814 libart.so (mterp_op_invoke_virtual+20)

二、如何找到符号表

1. mapping文件位置

如果在：<project>/<app-module>/build.gradle中打开了混淆，则在编译完成后会生成mapping文件。

android {
    ...
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    ...
}

默认情况下，mapping文件位置在<project>/<app-module>/build/outputs/mapping/<build-type>/。

2. SO符号表位置

Android平台中，Debug SO文件是指具有调试信息的SO文件，其中包含用户还原堆栈的符号信息。

• CMake编译项目

  默认情况下，编译的SO文件在<project>/<sdk-module>/build/intermediates/cmake/<build-type>/obj/CPU架构/。

  

• NDK编译项目

  默认情况下，编译的SO文件在<project>/<sdk-module>/build/intermediates/ndk/<build-type>/obj/CPU架构/。

  

三、如何上传符号表

详见 网页上传符号表。

四、FAQ

详见 符号表 FAQ。