Rust Binaries

Let us start with a simple application. At the root of an AOSP checkout, create the following files:

hello_rust/Android.bp:

rust_binary {
    name: "hello_rust",
    crate_name: "hello_rust",
    srcs: ["src/main.rs"],
}

hello_rust/src/main.rs:

//! Rust demo.

/// Prints a greeting to standard output.
fn main() {
    println!("Hello from Rust!");
}

You can now build, push, and run the binary:

m hello_rust
adb push "$ANDROID_PRODUCT_OUT/system/bin/hello_rust" /data/local/tmp
adb shell /data/local/tmp/hello_rust

Hello from Rust!

Go through the build steps and demonstrate them running in your emulator.
Notice the extensive documentation comments? The Android build rules enforce that all modules have documentation. Try removing it and see what error you get.
Stress that the Rust build rules look like the other Soong rules. This is on purpose to make it as easy to use Rust as C++ or Java.

Comprehensive Rust 🦀