Android build scripts

⚠️⚠️⚠️⚠️⚠️⚠️⚠️: This repository is now unused. We use https://github.com/measurement-kit/homebrew-measurement-kit now for cross building for Android.

This repository contains MK Android build scripts. The rest of this document describes the vanilla build procedure and other less common use cases of these scripts, along with details.

Tell the scripts about the NDK

Make sure that you have the NDK installed. Make sure that you are using the latest version using the proper channel. Then, let us know the location in which it is installed by using

export ANDROID_NDK_ROOT=/path/to/NDK  # $HOME/Library/Android/sdk/ndk-bundle on macOS

Check dependencies versions

In general we would like to build the latest version of a dependency. You can check that by looking into all the download scripts with:

vi `find . -type f -name download.sh | grep -v ./script`

If any dependency has been updated, fix the URL and the SHA256. Then also make sure that the corresponding build script is updated.

Check the output version

The output version is the version of the tarball produced by these scripts. It's located in the VERSION file. Make sure this is exactly the version that you would like to build.

Start over

To minimize the impact of human errors, we want all builds to be fully automated using these scripts. For this reason, you MUST start over before making a release build. First, make sure that you do not have any precious uncommitted files, then:

git clean -dffx

Downloading tarballs

Then download the tarballs with

./script/download.sh all

This will download packages tarballs in ./pkg.

Building libs

Then rebuild everything with

./script/build.sh all 2>&1 | tee BUILD.txt

This will compile in ./build and install in ./dist.

Smoke testing

Start a simulator from Android studio. It must be using an Android image not containing Google Play services because, apparently, in such images we cannot become root. Note the architecture used in the running simulator. Possibly use an old version of Android to have more confidence that there will be no undefined symbols etc.

Then run

./script/smoke-test.sh $arch 2>&1 | tee $arch.txt

The objective of this step is to make sure that the newly compiled code is not going to cause issues on old Android and possibly on a variety of architectures, before publishing the binaries.

Hence we can spot problems or be more confident earlier.

Package for distribution

Double check that you updated the VERSION file.

Then, run this script

./script/make-android-dist.sh

It will create a tarball in the toplevel directory and update SHA256SUMS.

Then:

• commit
• tag and sign the tag
• push
• make a GitHub release
• upload the tarball
• upload the build logs
• upload the test logs

Less common usage

Only rebuild a specific library

Instead of all you can also pass the name of a specific library. For example

./script/build.sh curl

In that case, make sure you also recompile all libs that depend on the library that you are currently recompiling.

This procedure MUST NOT be followed when making a stable release but it's of course acceptable when smoke testing.

Rebuilding a single lib for a specific arch

You may want to rebuild a single library for a specific arch with

./toolchain/$arch.sh ./$lib/build.sh

For example

./toolchain/arm64.sh ./measurement-kit/build.sh

If this step fail, make sure first that ANDROID_NDK_ROOT is exported. While outer level scripts check that, ./toolchain scripts do not. Hence the build may just be failing because the compiler couldn't be found.

This procedure MUST NOT be followed when making a stable release but it's of course acceptable when smoke testing.

Restarting or tweaking a specific build

Enter into the build directory

cd ./build/$arch/$lib/$tarball_dir
$do_something_here
../../../../toolchain/$arch.sh $build_command

For example

cd build/arm64-v8a/measurement-kit/measurement-kit-0.9.2/
vi src/measurement_kit/utils.cpp
../../../../toolchain/arm64.sh make

Again, this will fail weirdly if ANDROID_NDK_ROOT is not set.

This procedure MUST NOT be followed when making a stable release but it's of course acceptable when smoke testing.