How to debug cocos2d-x 3 native code on android device

Question

I could not find any cookbook/tutorial how build in debug build a cocos2d-x 3.1 project for Android and how to debug it directly on device. Please help by pointing out steps

Answer 1

Here is the step-by-stet tutorial to debug cocos2d-x 3.x on Android device. Please correct or optimize my steps if you do it in better way.

1. cd proj.android
2. cocos compile -p android -m debug --ndk-mode NDK_DEBUG=1 (to build with debug info)
3. cocos run -p android -m debug to deploy on device (sometimes it rebuilds, and I don't know why). This command uninstalls former installation, installs the new one and runs the app on the device.
4. make sure in proj.android/libs/armeabi directory you have the following files gdb.setup, gdbserver, libcocos2dcpp.so
5. also make sure that in /proj.android/jni/obj/local/armeabi directory you have app_process, gdb.setup, libc.so, linker
6. ndk-gdb (important! this should be called in projects directory, not in jni directory)

If it worked then congratulations! But in this step you may see such error message:

Nareks-MacBook-Pro:proj.android Narek$ ndk-gdb
jni/Android.mk:67: *** Android NDK: Aborting.    .  Stop.
ERROR: The device does not support the application's targetted CPU ABIs!
       Device supports:  armeabi-v7a armeabi
       Package supports: Android NDK: 

Don't worry :). Lets see what is wrong:

1. here is the result of ndk-build DUMP_APP_ABI command called in project's jni directory:

   Nareks-MacBook-Pro:jni Narek$ ndk-build DUMP_APP_ABI Android NDK: /Users/Narek/NoorGames/Games/test2/proj.android/jni/Android.mk: Cannot find module with tag '.' in import path
   Android NDK: Are you sure your NDK_MODULE_PATH variable is properly defined ?
   Android NDK: The following directories were searched:
   Android NDK:
   /Users/Narek/NoorGames/Games/test2/proj.android/jni/Android.mk:67: *** Android NDK: Aborting. . Stop.

As you can see NDK_MODULE_PATH is missing. For obtaining the value do the following. Go to step where you compiled code. In first linse of execution of command cocos compile -p android -m debug --ndk-mode NDK_DEBUG=1 you can see something like this:

Runing command: compile
Building mode: debug
building native
NDK build mode: NDK_DEBUG=1
The Selected NDK toolchain version was 4.8 !
running: '/Users/Narek/NoorGames/android-ndk-r9d/ndk-build -C /Users/Narek/NoorGames/Games/test2/proj.android -j1 NDK_MODULE_PATH=/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d:/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d/cocos:/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d/external'

2. copy from the log above you see the necessary value of NDK_MODULE_PATH. Execute the following command export NDK_MODULE_PATH=/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d:/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d/cocos:/Users/Narek/NoorGames/Games/test2/proj.android/../cocos2d/external (be attentive to copy your path not mine)

That's it. Now run game on device, cd proj.android, call ndk-gdb and you should be able to debug with gdb.

I personally looked for this kind of tutorial already more than 20 days. I hope you enjoy your debugging already. :) And thank you @VikasPatidar for your help with ndk-build DUMP_APP_ABI step!

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EDIT1: As commented Vikas you can add NDK_MODULE_PATH in Android.mk file like this:

NDK_MODULE_PATH := $(LOCAL_PATH)/../../../../cocos
NDK_MODULE_PATH += $(LOCAL_PATH)/../../../../external

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EDIT2: If your app crashed here is a very powerful and easy way to investigate the problem by preventing direct debugging:

adb logcat | $NDK_ROOT/ndk-stack -sym $PROJECT_PATH/obj/local/armeabi

It prints the crash dump.