build.rs

use std::path::PathBuf;
use std::{env, fs};

fn main() {
    let target = env::var("TARGET").unwrap();
    let host_triple = env::var("HOST").unwrap();
    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
    let name = env::var("CARGO_PKG_NAME").unwrap();

    if host_triple == target {
        println!("cargo:rustc-cfg=native");
    }

    if target.starts_with("thumb") {
        let suffix = if env::var_os("CARGO_FEATURE_LINKER_PLUGIN_LTO").is_some() {
            "-lto"
        } else {
            ""
        };

        fs::copy(
            format!("bin/{}{}.a", target, suffix),
            out_dir.join(format!("lib{}.a", name)),
        )
        .unwrap();

        println!("cargo:rustc-link-lib=static={}", name);
        println!("cargo:rustc-link-search={}", out_dir.display());
    }

    if target.starts_with("thumbv6m-") {
        println!("cargo:rustc-cfg=cortex_m");
        println!("cargo:rustc-cfg=armv6m");
    } else if target.starts_with("thumbv7m-") {
        println!("cargo:rustc-cfg=cortex_m");
        println!("cargo:rustc-cfg=armv7m");
    } else if target.starts_with("thumbv7em-") {
        println!("cargo:rustc-cfg=cortex_m");
        println!("cargo:rustc-cfg=armv7m");
        println!("cargo:rustc-cfg=armv7em"); // (not currently used)
    } else if target.starts_with("thumbv8m.base") {
        println!("cargo:rustc-cfg=cortex_m");
        println!("cargo:rustc-cfg=armv8m");
        println!("cargo:rustc-cfg=armv8m_base");
    } else if target.starts_with("thumbv8m.main") {
        println!("cargo:rustc-cfg=cortex_m");
        println!("cargo:rustc-cfg=armv8m");
        println!("cargo:rustc-cfg=armv8m_main");
    }

    if target.ends_with("-eabihf") {
        println!("cargo:rustc-cfg=has_fpu");
    }
}