build.rs

extern crate rustc_version;
use rustc_version::{version, version_meta, Channel};

fn build_tramp() {
    let mut builder = cc::Build::new();
    // --std=c99 -W -Wall -Werror -pedantic -O3 -flto
    builder
        .flag("--std=c99")
        .flag_if_supported("-Wall")
        .flag_if_supported("-Wextra")
        .flag_if_supported("-W")
        .flag_if_supported("-Werror")
        .flag("-pedantic")
        .opt_level(3);

    // Not sure if we want these two. We can check the codegen later.
    // .pic(false)
    // .use_plt(false)
    builder
        .file("alloca_trampoline_.c")
        .compile("calloca_trampoline");
}

fn main() {
    // Assert we haven't travelled back in time
    assert!(version().unwrap().major >= 1);
    println!("cargo::rustc-check-cfg=cfg(nightly)");

    // Set cfg flags depending on release channel
    match version_meta().unwrap().channel {
        Channel::Stable => {
            println!("cargo:rustc-cfg=stable");
        }
        Channel::Beta => {
            println!("cargo:rustc-cfg=beta");
        }
        Channel::Nightly => {
            println!("cargo:rustc-cfg=nightly");
        }
        Channel::Dev => {
            println!("cargo:rustc-cfg=dev");
        }
    }

    build_tramp();
}