Using Bindgen

First create a small C library:

interoperability/bindgen/libbirthday.h:

interoperability/bindgen/libbirthday.c:

#include <stdio.h> #include "libbirthday.h" void print_card(const card* card) { printf("+--------------\n"); printf("| Happy Birthday %s!\n", card->name); printf("| Congratulations with the %i years!\n", card->years); printf("+--------------\n"); }

Add this to your Android.bp file:

interoperability/bindgen/Android.bp:

Create a wrapper header file for the library (not strictly needed in this example):

interoperability/bindgen/libbirthday_wrapper.h:

#include "libbirthday.h"

You can now auto-generate the bindings:

interoperability/bindgen/Android.bp:

rust_bindgen { name: "libbirthday_bindgen", crate_name: "birthday_bindgen", wrapper_src: "libbirthday_wrapper.h", source_stem: "bindings", static_libs: ["libbirthday"], }

Finally, we can use the bindings in our Rust program:

interoperability/bindgen/main.rs:

Build, push, and run the binary on your device:

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

Finally, we can run auto-generated tests to ensure the bindings work:

interoperability/bindgen/Android.bp:

rust_test { name: "libbirthday_bindgen_test", srcs: [":libbirthday_bindgen"], crate_name: "libbirthday_bindgen_test", test_suites: ["general-tests"], auto_gen_config: true, clippy_lints: "none", // Generated file, skip linting lints: "none", }