为安卓系统编译bzip2？

git clone https://sourceware.org/git/bzip2.git

cd bzip2

export ANDROID_NDK_HOME=/path/to/android-ndk
export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin

mkdir build
cd build

cmake -G "Unix Makefiles" \
    -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake \
    -DANDROID_ABI=arm64-v8a \
    -DANDROID_PLATFORM=android-21 \
    -DCMAKE_BUILD_TYPE=Release \
    ../

make
make install DESTDIR=$ANDROID_NDK_HOME/sysroot/usr

android {
    ...
    defaultConfig {
        ...
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
        }
    }
    externalNativeBuild {
        cmake {
            path "src/main/cpp/CMakeLists.txt"
        }
    }
}

cmake_minimum_required(VERSION 3.4.1)

find_library(BZIP2_LIB bzip2 ${ANDROID_NDK_HOME}/sysroot/usr/lib)

add_library(
    your-library-name
    SHARED
    ...
    )

target_link_libraries(
    your-library-name
    ${BZIP2_LIB}
    )