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I've looked around but I've only been able to find solutions that use Android.mk and Application.mk. Am I right in thinking that by using CMakeLists.txt I don't need either of those files? This is my first venture into using the Android NDK.

I've based my CMakeLists.txt off of the SuperpoweredExample and I have called my library nativelib. It seems the .cpp file cannot pick up the references in the header file. Am I doing something wrong? It builds fine but it just throws these errors on compilation.

CMakeLists.txt:

cmake_minimum_required(VERSION 3.4.1)

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds it for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             nativelib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             G:/Git/NDKTest/app/src/main/jni/nativelib.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because system libraries are included in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in the
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       nativelib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

//////////////////////////////////////////////////////////////    
//////////////////////////////////////////////////////////////
// Below here is copy and pasted from the SuperpoweredExample
//////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////

set(
    PATH_TO_SUPERPOWERED
    "C:/Users/j/Downloads/Superpowered/Superpowered"
)

message(${ANDROID_ABI})

file(GLOB CPP_FILES "*.cpp")

add_library(
    SuperpoweredExample
    SHARED
    ${CPP_FILES}
    ${PATH_TO_SUPERPOWERED}/AndroidIO/SuperpoweredAndroidAudioIO.cpp
)

include_directories(src/main/jni)
include_directories(${PATH_TO_SUPERPOWERED})

target_link_libraries(
    SuperpoweredExample
    log
    android
    OpenSLES
    ${PATH_TO_SUPERPOWERED}/libSuperpoweredAndroid${ANDROID_ABI}.a
    nativelib
)

Stacktrace:

Error:FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:externalNativeBuildDebug'.
> Build command failed.
Error while executing 'G:\sdk1\cmake\3.6.3155560\bin\cmake.exe' with arguments {--build G:\Git\NDKTest\app\.externalNativeBuild\cmake\debug\x86 --target nativelib}
[1/2] Building CXX object CMakeFiles/nativelib.dir/nativelib.cpp.o
[2/2] Linking CXX shared library G:\Git\NDKTest\app\build\intermediates\cmake\debug\obj\x86\libnativelib.so
FAILED: cmd.exe /C "cd . && G:\sdk1\ndk-bundle\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe  -target i686-none-linux-android -gcc-toolchain G:/sdk1/ndk-bundle/toolchains/x86-4.9/prebuilt/windows-x86_64 --sysroot=G:/sdk1/ndk-bundle/platforms/android-16/arch-x86 -fPIC -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -Wa,--noexecstack -Wformat -Werror=format-security -fno-exceptions -fno-rtti -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -Wa,--noexecstack -Wformat -Werror=format-security -fno-exceptions -fno-rtti -fsigned-char -Inull -O0 -fno-limit-debug-info -O0 -fno-limit-debug-info  -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -shared -Wl,-soname,libnativelib.so -o G:\Git\NDKTest\app\build\intermediates\cmake\debug\obj\x86\libnativelib.so CMakeFiles/nativelib.dir/nativelib.cpp.o  -llog -lm "G:/sdk1/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/libs/x86/libgnustl_static.a" && cd ."
G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:16: error: undefined reference to 'SuperpoweredRoll::SuperpoweredRoll(unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:17: error: undefined reference to 'SuperpoweredFilter::SuperpoweredFilter(SuperpoweredFilterType, unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:18: error: undefined reference to 'SuperpoweredFlanger::SuperpoweredFlanger(unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:19: error: undefined reference to 'SuperpoweredRecorder::SuperpoweredRecorder(char const*, unsigned int, unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:21: error: undefined reference to 'SuperpoweredAndroidAudioIO::SuperpoweredAndroidAudioIO(int, int, bool, bool, bool (*)(void*, short*, int, int), void*, int, int, int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:28: error: undefined reference to 'SuperpoweredRecorder::stop()'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:30: error: undefined reference to 'SuperpoweredRecorder::start(char const*)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:37: error: undefined reference to 'SuperpoweredRecorder::process(float*, float*, unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:38: error: undefined reference to 'SuperpoweredFloatToShortInt(float*, short*, unsigned int, unsigned int)'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:43: error: undefined reference to 'SuperpoweredAndroidAudioIO::~SuperpoweredAndroidAudioIO()'
  G:\Git\NDKTest\app\src\main\jni/nativelib.cpp:44: error: undefined reference to 'SuperpoweredRecorder::~SuperpoweredRecorder()'
  clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation)
  ninja: build stopped: subcommand failed.


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

Changed name from native-lib to nativelib, same error.

I have a feeling the error is around the target_link_libraries() of CMakeLists.txt. I am trying to link my NativeLib code with the existing SuperpoweredExample code.

Josh Laird
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    That's a compiler error. Are you sure all includes are provided? Does it compile if you type the compiler command by hand? Then you might want to compare your command with CMake's one (using VERBOSE=ON) – usr1234567 Nov 12 '16 at 09:38

1 Answers1

3

I think linking your "nativelib" happens before linking the Superpowered example, therefore your linker can't find the Superpowered parts used by "nativelib".

Gabor Szanto
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