Android NDK&JNI开发之Native崩溃日志分析方法

在进行Android NDK开发的时候， 因为代码编写导致崩溃的问题时有发生，但是问题在于，Native层的崩溃日志，如果只看LogCat输出的内容，我们会发现，根本无法进行分析和处理，因为日志内容中都是一大堆的内存地址信息。

原始错误日志：

2020-08-20 18:04:01.149 27129-27129/? A/DEBUG: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
2020-08-20 18:04:01.150 27129-27129/? A/DEBUG: Build fingerprint: 'HONOR/LLD-AL00/HWLLD-H:9/HONORLLD-AL00/9.1.0.140C00:user/release-keys'
2020-08-20 18:04:01.150 27129-27129/? A/DEBUG: Revision: '0'
2020-08-20 18:04:01.150 27129-27129/? A/DEBUG: ABI: 'arm'
2020-08-20 18:04:01.150 27129-27129/? A/DEBUG: Happend: 'Thu Aug 20 18:04:01 2020
    '
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG: SYSVMTYPE: Art
    APPVMTYPE: Art
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG: pid: 26194, tid: 27088, name: Thread-1682  >>> com.renhui.maomaomedia <<<
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG: Cause: null pointer dereference
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG:     r0  c8da4000  r1  00000000  r2  eed3a564  r3  40000000
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG:     r4  c58858f0  r5  c5885970  r6  c5885970  r7  c5885940
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG:     r8  00006652  r9  000069cd  r10 c92a626d  r11 c8da4000
2020-08-20 18:04:01.151 27129-27129/? A/DEBUG:     ip  c954dfa8  sp  c58858f0  lr  c92a641b  pc  c92a62a4
2020-08-20 18:04:01.153 27129-27129/? A/DEBUG: backtrace:
2020-08-20 18:04:01.153 27129-27129/? A/DEBUG:     #00 pc 000192a4  /data/app/com.renhui.maomaomedia-HZzt4BSwxxXs-qqIDrrlng==/lib/arm/libmedia-editor-lib.so (VideoHandler::decodeVideo()+28)
2020-08-20 18:04:01.153 27129-27129/? A/DEBUG:     #01 pc 0001927b  /data/app/com.renhui.maomaomedia-HZzt4BSwxxXs-qqIDrrlng==/lib/arm/libmedia-editor-lib.so (decodeVideoT(void*)+14)
2020-08-20 18:04:01.153 27129-27129/? A/DEBUG:     #02 pc 00065ac7  /system/lib/libc.so (__pthread_start(void*)+22)
2020-08-20 18:04:01.153 27129-27129/? A/DEBUG:     #03 pc 0001e9ad  /system/lib/libc.so (__start_thread+32)

Native日志分析方式：

将LogCat输出的Native崩溃日志，拷贝到crash.log（注意：最好以星号这行开始），并复制到build目录下的cmake编译后的so文件目录下，需要注意的是编译目录armeabi要和crash.log对应，cmakedebugobjarm-XXX目录下要有so文件,这个是编译的时候生成的。

例如，我们运行的so文件是armeabi-v7a下的，那么拷贝到此下面，执行如下命令：

ndk-stack -sym C:UsersmaomaoDesktopWukongMemoMaoMaoMediaplayeruildintermediatescmakedebugobjarmeabi-v7a -dump crash.log

然后我们就能看到带文件名、函数名和行号的log日志了，进而我们就可以进一步排查和修复问题了。

C:UsersmaomaoDesktopWukongMemoMaoMaoMediaplayeruildintermediatescmakedebugobj>ndk-stack -sym C:UsersmaomaoDesktopWukongMemoMaoMaoMediaplayeruildintermed
iatescmakedebugobjarmeabi-v7a -dump crash.log
********** Crash dump: **********
Build fingerprint: 'HONOR/LLD-AL00/HWLLD-H:9/HONORLLD-AL00/9.1.0.140C00:user/release-keys'
#00 0x000192a4 /data/app/com.renhui.maomaomedia-HZzt4BSwxxXs-qqIDrrlng==/lib/arm/libmedia-editor-lib.so (VideoHandler::decodeVideo()+28)
                                                                                                         VideoHandler::decodeVideo()
                                                                                                         C:UsersmaomaoDesktopWukongMemoMaoMaoMediaplayer.cxxcmakedeb
ugarmeabi-v7a../../../../src/main/cpp/playerVideoHandler.cpp:59:27
#01 0x0001927b /data/app/com.renhui.maomaomedia-HZzt4BSwxxXs-qqIDrrlng==/lib/arm/libmedia-editor-lib.so (decodeVideoT(void*)+14)
                                                                                                         decodeVideoT(void*)
                                                                                                         C:UsersmaomaoDesktopWukongMemoMaoMaoMediaplayer.cxxcmakedeb
ugarmeabi-v7a../../../../src/main/cpp/playerVideoHandler.cpp:20:19
#02 0x00065ac7 /system/lib/libc.so (__pthread_start(void*)+22)
#03 0x0001e9ad /system/lib/libc.so (__start_thread+32)
Crash dump is completed