build.rs

use std::env;

// This code is adapted from pkg-config-rs
// (https://github.com/rust-lang/pkg-config-rs).
fn infer_static(name: &str) -> bool {
    #[allow(clippy::if_same_then_else, clippy::needless_bool)]
    if env::var(format!("{}_STATIC", name.to_uppercase())).is_ok() {
        true
    } else if env::var(format!("{}_DYNAMIC", name.to_uppercase())).is_ok() {
        false
    } else if env::var("PKG_CONFIG_ALL_STATIC").is_ok() {
        true
    } else if env::var("PKG_CONFIG_ALL_DYNAMIC").is_ok() {
        false
    } else {
        false
    }
}

fn main() {
    // Gather build time info
    built::write_built_file().expect("Failed to acquire build-time information");

    //
    // Link to shared or static CFITSIO
    //
    // Check if we have this environment variable
    // If we do, then we will link to cfitsio statically
    // But if so, you need to have:
    // 1. libcfitsio.a in your LD_LIBRARY_PATH or PATH
    // AND
    // 2. libcfitsio.a needs to have been built with the following ./configure statement:
    //    ./configure --disable-curl --prefix=/usr/local --enable-reentrant
    if env::var("MWALIB_LINK_STATIC_CFITSIO") == Ok("1".to_string()) || infer_static("cfitsio") {
        println!("cargo:rustc-link-lib=static=cfitsio");
    }

    // Only do this if we're not on docs.rs (doesn't like writing files outside
    // of OUT_DIR).
    match env::var("DOCS_RS").as_deref() {
        Ok("1") => (),
        _ => {
            let mut config: cbindgen::Config = cbindgen::Config::default();

            config.cpp_compat = true;
            config.pragma_once = true;

            cbindgen::Builder::new()
                .with_config(config)
                .with_crate(env::var("CARGO_MANIFEST_DIR").unwrap())
                .with_language(cbindgen::Language::C)
                .generate()
                .expect("Unable to generate bindings")
                .write_to_file("include/mwalib.h");
        }
    }
}