Rust Libraries

You use rust_library to create a new Rust library for Android.

Here we declare a dependency on two libraries:

  • libgreeting, which we define below,
  • libtextwrap, which is a crate already vendored in external/rust/crates/.

hello_rust/Android.bp:

  1. rust_binary {
  2.     name: "hello_rust_with_dep",
  3.     crate_name: "hello_rust_with_dep",
  4.     srcs: ["src/main.rs"],
  5.     rustlibs: [
  6.         "libgreetings",
  7.         "libtextwrap",
  8.     ],
  9.     prefer_rlib: true, // Need this to avoid dynamic link error.
  10. }
  12. rust_library {
  13.     name: "libgreetings",
  14.     crate_name: "greetings",
  15.     srcs: ["src/lib.rs"],
  16. }

hello_rust/src/main.rs:

  1. //! Rust demo.
  3. use greetings::greeting;
  4. use textwrap::fill;
  6. /// Prints a greeting to standard output.
  7. fn main() {
  8.     println!("{}", fill(&greeting("Bob"), 24));
  9. }

hello_rust/src/lib.rs:

  1. //! Greeting library.
  3. /// Greet `name`.
  4. pub fn greeting(name: &str) -> String {
  5.     format!("Hello {name}, it is very nice to meet you!")
  6. }

You build, push, and run the binary like before:

  1. m hello_rust_with_dep
  2. adb push "$ANDROID_PRODUCT_OUT/system/bin/hello_rust_with_dep" /data/local/tmp
  3. adb shell /data/local/tmp/hello_rust_with_dep
  1. Hello Bob, it is very
  2. nice to meet you!