[SOLVED] Android Studio CMake - shared library missing libc++

Android Studio CMake - shared library missing libc++_shared.so? Can CMake bundle this?

Now that Android Studio 2.2 is released officially, I'm migrating from my old ndk-build process to try and use CMake within AS. As I'm incorporating several codebases from within my company (that I can't edit) that make heavy use of C++11 code (including the dreaded std::to_string() method), the only way I can compile is with a select few configuration options - all of which I discovered earlier when beginning work with ndk-build. (see below)

So everything compiles again and builds into the APK - and I 100% verify that my output shared library exists in the APK, but I'm unable to successfully use System.loadLibrary('mylibrary') - and it turns out this is because the dependency libc++_shared.so is missing.

As in, I get the following error:

java.lang.UnsatisfiedLinkError: dlopen failed: library "libc++_shared.so" not found

In my old ndk-build process, I always wound up with the 2 libraries (mylibrary.so and libc++_shared.so) in my output folder, which thereby got bundled together into the app. It seems the CMake toolchain isn't bundling libc++_shared.so at all (indeed, it's not found in the APK).

I've been banging my head on this for 6 hours. Can I somehow get the CMake toolchain to bundle this missing library? Any clues?

My settings:

In gradle.build:

externalNativeBuild {
        cmake {
            arguments '-DANDROID_STL=c++_shared', '-DANDROID_TOOLCHAIN=gcc', '-DANDROID_PLATFORM=android-16'
        }
    }

And my CMakeLists.txt (filenames cut out for brevity):

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -std=gnu++11")

include_directories(.)
include_directories(./other)

set(my_SRCS jniInterface.cpp
    etc.cpp)


add_library(mylibrary SHARED ${my_SRCS})

target_link_libraries(mylibrary atomic log)

Solution

I wrote a CMake config that should package the STL files: https://github.com/jomof/ndk-stl/blob/master/ndk-stl-config.cmake

Copy this file next to your CMakeLists.txt and inside CMakeLists.txt do

include(ndk-stl-config.cmake)

Let me know if you have problems