use std::env; fn main() { let target = env::var("TARGET").unwrap(); if target.starts_with("thumbv6m") { println!("cargo:rustc-cfg=armv6m") } if target.starts_with("thumbv7m") | target.starts_with("thumbv7em") | target.starts_with("thumbv8m") { println!("cargo:rustc-cfg=armv7m") } println!("cargo:rerun-if-changed=build.rs"); }