Compiling and linking error when using NDK r10 to build cocos2d-x v3.2

By zhangxm Posted  about 2 hours ago

If you use NDK r10 to build cocos2d-x v3.2, you will meet a compiling error of all tests and linking error of lua tests.

compiling error

The error message is

/Users/minggo/SourceCode/cocos2d-x/build/../cocos/./3d/CCBundleReader.cpp:94:23: error: 
      return type of out-of-line definition of 'cocos2d::BundleReader::tell'
      differs from that in the declaration
ssize_t BundleReader::tell()
                      ^
/Users/minggo/SourceCode/cocos2d-x/build/../cocos/./3d/CCBundleReader.h:90:14: note: 
      previous declaration is here
    long int tell();

This compiling error is fixed in this patch. We are sorry about it.

linking error

After fixing the compiling error, you will meet linking error when building lua test cases or new lua projects

/Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld: error: /Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/libgcc.a(pr-support.o): multiple definition of '_Unwind_GetRegionStart'
/Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld: /Users/minggo/bin/android/android-ndk-r10/sources/cxx-stl/llvm-libc++/libs/armeabi/thumb/libc++_static.a(Unwind-EHABI.o): previous definition here
/Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld: error: /Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/libgcc.a(pr-support.o): multiple definition of '_Unwind_GetLanguageSpecificData'
/Users/minggo/bin/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld: /Users/minggo/bin/android/android-ndk-r10/sources/cxx-stl/llvm-libc++/libs/armeabi/thumb/libc++_static.a(Unwind-EHABI.o): previous definition here
clang++: error: linker command failed with exit code 1 (use -v to see invocation)

I have created a ticket in Android issue system for it. And NDK developers confirmed it is a bug of NDK r10. And he gave two ways to work around it:

• requires makefile changes to drop libgcc.a with command line reads "-nodefaultlibs -lstdc++ -latomic -ldl -lm -lc -lcompiler_rt_static"

  Because we don't use standalone toolchain, so changing makefile doesn't work for cocos2d-x.

• use libc++_shared.so and add LIBCXX_USE_GABIXX:=true in Application.mk which force rebuild libc++ to use gabi++

  This method requires to use shared library and modify Cocos2dxActivity.java to load dependened shared library. We don't want to modify like this, because:

  • We haven't used shared library before which means we haven't tested
  • It will make .apk 0.13M bigger then using static library
  • Google guy will fix it in next NDK version

conclusion

We suggest you not to use NDK r10. Please use NDK r9d instead. If you want to use NDK r10, the following steps can help you work around it:

• Change long int to ssize_t in the declaration of BundleReader::tell(). You can refer to this pull request for detail information.
• Change APP_STL:=c++_static to APP_STL:=c++_shared, add LIBCXX_USE_GABIXX:=true inApplication.mk, and modify your java activity code to load libc++_shared.so. You can refer to this commit for more detail information