use std::env; fn main() { let target = env::var("TARGET").unwrap(); if target.starts_with("x86_64") || target.starts_with("i686") || target.starts_with("aarch64") || target.starts_with("powerpc64") || target.starts_with("sparc64") || target.starts_with("mips64el") || target.starts_with("riscv64") { println!("cargo:rustc-cfg=threadfin_has_atomic64"); } }