Tools

Build

Prerequisites

• cURL

• JDK (>=1.8)

• Ruby

  Gem toml is required. You can install it using:

  gem install toml

• CMake (>=3.10.0)

Set Up SDK and NDK Paths

Add property sdk.dir=SDK_PATH (replace SDK_PATH with your Android SDK path) to file local.properties at the project root (create if it doesn't exist).

The NDK is expected to be detected automatically, or you can also specify it via ndk.dir or ndk.version.

Set Up NDK Custom Configurations

In the project root, create a file: config.toml. Here is a sample configuration:

[ndk]
#targets = ["armeabi-v7a-21", "arm64-v8a-29", "x86-29", "x86_64-29"]
targets = ["arm64-v8a-21"]
build_type = "release"
openssl_dir = "/home/bczhc/bin/openssl"

[ndk.rust]
enable_build = true
enable_jni = true
keep_debug_symbols = false

The accepted properties are:

• ndk.targets

  A "target string" is in the format <ABI>-<API>. Possible values of ABI are armeabi-v7a, arm64-v8a, x86 and x86_64, and you can refer to Android supported ABIs. The API value is an integer, you can refer to Platform codenames, versions, API levels, and NDK releases. Multiple targets are separated by commas.

• ndk.build_type

  It can be debug or release; this will be applied to both C/C++ and Rust builds.

• ndk.openssl_dir

  OpenSSL path. See below.

• ndk.rust.enable_build

  Add Rust build process to the project's Gradle task tree.

• ndk.rust.enable_jni

  Enable Rust functions in-app.

  Disabling it will cause all functions related to JNI written in Rust unusable, and the app will crash on using them.

  Enabling ndk.rust.enable_jni and disabling ndk.rust.enable_build is useful when Rust JNI libraries are present as pre-compiled, and the host machine lacks Rust toolchains.

• ndk.rust.keep_debug_symbols

  Keep Rust library debug symbols.

Compile OpenSSL

First clone OpenSSL from its GitHub repository: https://github.com/openssl/openssl, and checkout tag openssl-3.0.1.

These commands below should work:

git clone https://github.com/openssl/openssl --depth 1
cd openssl
git fetch --unshallow
git fetch origin openssl-3.0
git fetch --all
git checkout openssl-3.0.1

Then go back into this project and run ./tools/build-openssl <openssl-path> with a path to OpenSSL's project root. This will cross-compile OpenSSL libraries in the targets defined in config.toml.

The compiled libraries are stored in <openssl-dir>/libs/<Android-ABI>/.

Don't forget to set ndk.openssl_dir to the OpenSSL project root in config.toml.

Configure Rust

If you don't have Rust installed, you can install it first by running:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Note: This installation method is recommended, since it has a good Rust toolchain manager rustup.

Then, to add Rust targets for Android, run:

rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android i686-linux-android

Build Project

Run ./gradlew :app:assembleDebug or ./gradlew asD for debug build.

Run ./gradlew :app:assembleRelease or ./gradlew asR for release build.