addr2line是一個十分有用的debug工具，這個工具在ndk的安裝目錄下就有
在ndk \toolchains\aarch64-linux-android-4.9\prebuilt\windows-x86_64\bin目錄下
可以用於幫助我們分析jni 裏面的bug，下面我們故意在jni代碼中留一個異常，在運行到memcpy就會發生空指針異常，應用會閃退。
運行之後，通過log我們得到如下信息
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)
從打印的log信息我們知道發生問題時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，我們要拿到編譯出來的so文件。
根據ndk編譯時的輸出信息，知道so在libs/arm64-v8a/libneondemo.so
是app\src\main\obj\local\arm64-v8a這個目錄，不是app\src\main\libs\arm64-v8a
然後把so拷貝到tool_addr2line.bat 這個腳本所在的目錄下。腳本內容如下：
@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=請輸入當前目錄下debug文件名：
rem debug_file_path
set debug_file_path=%cur_dir%\%debug_file%
rem debug address
set /p debug_addr=請輸入異常時PC寄存器值：
echo ----------------------- addr2line ------------------------
echo debug文件路徑: %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
運行腳本，根據提示進行輸入
_ZL4neonP7_JNIEnv 這個是函數名，因爲android編譯時做了一些特殊處理，所以跟原來的函數名不一致。
E:\project\android_project\NeonDemo\app\src\main/jni/native.cpp:75 是發生異常對應源代碼中的位置。
