build.rs

use anyhow::*;
use glob::glob;
use std::path::Path;
use std::result::Result::Ok;
use std::{env, io};

/// Adds a temporary workaround for an issue with the Rust compiler and Android
/// in x86_64 devices: https://github.com/rust-lang/rust/issues/109717.
/// The workaround comes from: https://github.com/smartvaults/smartvaults/blob/827805a989561b78c0ea5b41f2c1c9e9e59545e0/bindings/smartvaults-sdk-ffi/build.rs
fn setup_x86_64_android_workaround() {
    let target_os = env::var("CARGO_CFG_TARGET_OS").expect("CARGO_CFG_TARGET_OS not set");
    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").expect("CARGO_CFG_TARGET_ARCH not set");
    if target_arch == "x86_64" && target_os == "android" {
        let android_ndk_home = env::var("ANDROID_NDK_HOME").expect("ANDROID_NDK_HOME not set");
        let build_os = match env::consts::OS {
            "linux" => "linux",
            "macos" => "darwin",
            "windows" => "windows",
            _ => panic!(
                "Unsupported OS. You must use either Linux, MacOS or Windows to build the crate."
            ),
        };
        let linux_x86_64_lib_pattern = format!(
            "{android_ndk_home}/toolchains/llvm/prebuilt/{build_os}-x86_64/lib*/clang/**/lib/linux/"
        );
        match glob(&linux_x86_64_lib_pattern).unwrap().last() {
            Some(Ok(path)) => {
                println!("cargo:rustc-link-search={}", path.to_string_lossy());
                println!("cargo:rustc-link-lib=static=clang_rt.builtins-x86_64-android");    
            },
            _ => panic!("Path not found: {linux_x86_64_lib_pattern}. Try setting a different ANDROID_NDK_HOME."),
        }
    }
}

pub fn compile_protos(proto: impl AsRef<Path>) -> io::Result<()> {
    let proto_path: &Path = proto.as_ref();
    let proto_dir = proto_path
        .parent()
        .expect("proto file should reside in a directory");
    let target_family =
        env::var("CARGO_CFG_TARGET_FAMILY").expect("CARGO_CFG_TARGET_FAMILY not set");
    let target_os = std::env::var("CARGO_CFG_TARGET_OS").expect("CARGO_CFG_TARGET_OS not set");
    let is_wasm = target_family == "wasm" && target_os == "unknown";

    tonic_build::configure()
        .build_server(false)
        .build_client(true)
        .build_transport(!is_wasm)
        .compile(&[proto_path], &[proto_dir])?;
    Ok(())
}

fn main() -> Result<()> {
    setup_x86_64_android_workaround();
    compile_protos("src/sync/proto/sync.proto")?;
    Ok(())
}