ndk addr2line工具的使用

addr2line是一个十分有用的debug工具，这个工具在ndk的安装目录下就有

在ndk \toolchains\aarch64-linux-android-4.9\prebuilt\windows-x86_64\bin目录下

可以用于帮助我们分析jni 里面的bug，下面我们故意在jni代码中留一个异常，在运行到memcpy就会发生空指针异常，应用会闪退。

运行之后，通过log我们得到如下信息

09-08 14:35:53.777 F/DEBUG   ( 6893): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
09-08 14:35:53.853 F/DEBUG   ( 6893): Build fingerprint: 'Android/sdk_google_phone_arm64/generic_arm64:7.1.1/NYC/4252396:userdebug/test-keys'
09-08 14:35:53.853 F/DEBUG   ( 6893): Revision: '0'
09-08 14:35:53.853 F/DEBUG   ( 6893): ABI: 'arm64'
09-08 14:35:53.854 F/DEBUG   ( 6893): pid: 6867, tid: 6867, name: hxiong.neondemo  >>> com.hxiong.neondemo <<<
09-08 14:35:53.854 F/DEBUG   ( 6893): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0
09-08 14:35:53.855 F/DEBUG   ( 6893):     x0   0000000000000003  x1   0000000000000000  x2   0000000000000004  x3   0000007ffb9e6980
09-08 14:35:53.855 F/DEBUG   ( 6893):     x4   0000007329c01ad3  x5   0000007ffb9e7360  x6   0000007337196000  x7   fffffffffffffffd
09-08 14:35:53.855 F/DEBUG   ( 6893):     x8   0000000000000003  x9   0000007335738c79  x10  0000000000000058  x11  0101010101010101
09-08 14:35:53.855 F/DEBUG   ( 6893):     x12  000000000ccccccc  x13  000000008000002f  x14  00000073357429e8  x15  000000733574268c
09-08 14:35:53.855 F/DEBUG   ( 6893):     x16  000000733575e2c0  x17  00000073356b8368  x18  00000000ffffffff  x19  ffffffffffffffff
09-08 14:35:53.855 F/DEBUG   ( 6893):     x20  000000000000000e  x21  00000000ffffffff  x22  0000007ffb9e6b60  x23  0000000000000001
09-08 14:35:53.855 F/DEBUG   ( 6893):     x24  0000007329c01ae3  x25  0000000000000003  x26  0000000000000073  x27  0000007ffb9e70b0
09-08 14:35:53.856 F/DEBUG   ( 6893):     x28  6cd7b2dd5dd0d059  x29  0000007ffb9e67a0  x30  0000007335710f64
09-08 14:35:53.856 F/DEBUG   ( 6893):     sp   0000007ffb9e6790  pc   00000073356b83c8  pstate 0000000080000000
09-08 14:35:54.233 F/DEBUG   ( 6893): 
09-08 14:35:54.233 F/DEBUG   ( 6893): backtrace:
09-08 14:35:54.234 F/DEBUG   ( 6893):     #00 pc 000000000001b3c8  /system/lib64/libc.so (strlen+96)
09-08 14:35:54.234 F/DEBUG   ( 6893):     #01 pc 0000000000073f60  /system/lib64/libc.so (__strlen_chk+16)
09-08 14:35:54.234 F/DEBUG   ( 6893):     #02 pc 000000000005ba18  /system/lib64/libc.so (__vfprintf+6356)
09-08 14:35:54.234 F/DEBUG   ( 6893):     #03 pc 0000000000064be4  /system/lib64/libc.so (vsnprintf+228)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #04 pc 00000000000741a0  /system/lib64/libc.so (__vsnprintf_chk+64)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #05 pc 00000000000057c8  /system/lib64/liblog.so (__android_log_print+148)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #06 pc 00000000000009a4  /data/app/com.hxiong.neondemo-1/lib/arm64/libneondemo.so
09-08 14:35:54.235 F/DEBUG   ( 6893):     #07 pc 00000000000dbb10  /system/lib64/libart.so (art_quick_generic_jni_trampoline+144)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #08 pc 00000000000d27e8  /system/lib64/libart.so (art_quick_invoke_static_stub+600)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #09 pc 00000000000df230  /system/lib64/libart.so (_ZN3art9ArtMethod6InvokeEPNS_6ThreadEPjjPNS_6JValueEPKc+252)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #10 pc 000000000028eefc  /system/lib64/libart.so (_ZN3art11interpreter34ArtInterpreterToCompiledCodeBridgeEPNS_6ThreadEPNS_9ArtMethodEPKNS_7DexFile8CodeItemEPNS_11ShadowFrameEPNS_6JValueE+312)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #11 pc 0000000000287ed8  /system/lib64/libart.so (_ZN3art11interpreter6DoCallILb0ELb0EEEbPNS_9ArtMethodEPNS_6ThreadERNS_11ShadowFrameEPKNS_11InstructionEtPNS_6JValueE+592)
09-08 14:35:54.235 F/DEBUG   ( 6893):     #12 pc 0000000000555cec  /system/lib64/libart.so (MterpInvokeStatic+356)
09-08 14:35:54.236 F/DEBUG   ( 6893):     #13 pc 00000000000c5094  /system/lib64/libart.so (ExecuteMterpImpl+14612)

从打印的log信息我们知道发生问题时pc寄存器的值

09-08 14:35:54.235 F/DEBUG   ( 6893):     #06 pc 00000000000009a4  /data/app/com.hxiong.neondemo-1/lib/arm64/libneondemo.so

接着，我们要拿到编译出来的so文件。

根据ndk编译时的输出信息，知道so在libs/arm64-v8a/libneondemo.so

是app\src\main\obj\local\arm64-v8a这个目录，不是app\src\main\libs\arm64-v8a

然后把so拷贝到tool_addr2line.bat 这个脚本所在的目录下。脚本内容如下：

@echo off
rem current direction
set cur_dir=%cd%

rem addr2line tool path
set add2line_path=D:\Android\sdk\ndk-bundle\toolchains\aarch64-linux-android-4.9\prebuilt\windows-x86_64\bin\aarch64-linux-android-addr2line.exe

rem debug file
set /p debug_file=请输入当前目录下debug文件名：

rem debug_file_path
set debug_file_path=%cur_dir%\%debug_file%

rem debug address
set /p debug_addr=请输入异常时PC寄存器值：

echo ----------------------- addr2line ------------------------
echo debug文件路径: %debug_file_path%  PC=%debug_addr%

if exist %debug_file_path% (
%add2line_path% -e %debug_file_path% -f %debug_addr% 
) else (
echo debug file is no exist. 
)

echo ---------------------------------------------------------
pause

运行脚本，根据提示进行输入

_ZL4neonP7_JNIEnv 这个是函数名，因为android编译时做了一些特殊处理，所以跟原来的函数名不一致。

E:\project\android_project\NeonDemo\app\src\main/jni/native.cpp:75 是发生异常对应源代码中的位置。