The latest version of this document is available at https://android.googlesource.com/platform/ndk/+/master/README.md.
Note: This document is for developers of the NDK, not developers that use the NDK.
The NDK allows Android application developers to include native code in their Android application packages, compiled as JNI shared libraries.
Both Linux and Windows NDKs are built on Linux machines. Windows host binaries are cross-compiled with MinGW.
Building the NDK for Mac OS X requires at least 10.8.
The NDK components can be loosely grouped into host toolchains, target prebuilts, build systems, and support libraries.
toolchains/contains GCC and Clang toolchains.
$TOOLCHAIN/config.mkcontains ARCH and ABIS this toolchain can handle.
$TOOLCHAIN/setup.mkcontains toolchain-specific default CFLAGS/LDFLAGS when this toolchain is used.
prebuilt/$HOST_TAGcontains build dependencies and additional tools.
ndk-gdbcan also be found here.
sysroot/usr/includecontains the headers for the NDK. See Unified Headers for more information.
platforms/android-$VERSION/arch-$ARCH_NAME/contains stub shared libraries and a few static libraries for each API level. See Platform APIs for more information.
sources/cxx-stl/$STLcontains the headers and libraries for the various C++ STLs.
build/contains ndk-build, the NDK's home grown build system. Most of the implementation lives in
build/cmakecontains components for using the NDK with CMake (at present only a CMake toolchain file, but in the future it will contain CMake modules that CMake will load, obviating the need for a toolchain file).
make_standalone_toolchain.py, but also contains legacy sripts that were used to build the NDK. Eventually, this should contain nothing but the standalone toolchain scripts.
sources/third_partycontain modules that can be used in apps (gtest, cpufeatures, native_app_glue, etc) via
Check out the branch
repo init -u https://android.googlesource.com/platform/manifest \ -b master-ndk # Googlers, use repo init -u \ persistent-https://android.git.corp.google.com/platform/manifest \ -b master-ndk
Linux dependencies are listed in the Dockerfile. You can use docker to build the NDK:
docker build -t ndk-dev infra/docker docker run -it -u $UID -v `realpath ..`:/src -w /src/ndk ndk-dev ./checkbuild.py
Building on Mac OS X has similar dependencies as Linux, but also requires Xcode.
Running tests requires that
adb is in your
PATH. This is provided as part of the Android SDK.
$ python checkbuild.py
$ python checkbuild.py --system windows # Or windows64.
checkbuild.py will also build all of the NDK tests. This takes about four times as long as building the NDK itself, so pass
--no-build-tests to skip building the tests. They can be built later with
python run_tests.py --rebuild.
checkbuild.py also accepts a variety of other options to speed up local builds, namely
checkbuild.py will also package the NDK. To skip the packaging step, use the
--no-package flag. To avoid packaging an incomplete NDK, packaging will not be run if
--module was passed unless
--force-package was also provided.