build.rs

use std::{collections::HashSet, env};

fn features_enabled() -> HashSet<String> {
    env::vars()
        .map(|(key, _)| key)
        .flat_map(|feature| {
            feature
                .strip_prefix("CARGO_FEATURE_")
                .map(str::to_lowercase)
        })
        .collect()
}

fn features_10xx() -> HashSet<String> {
    [
        "imxrt1010",
        "imxrt1015",
        "imxrt1020",
        "imxrt1050",
        "imxrt1060",
        "imxrt1064",
    ]
    .iter()
    .map(ToString::to_string)
    .collect()
}

fn features_11xx() -> HashSet<String> {
    ["imxrt1160", "imxrt1170"]
        .iter()
        .map(ToString::to_string)
        .collect()
}

fn features_chip() -> HashSet<String> {
    features_10xx().into_iter().chain(features_11xx()).collect()
}

fn main() {
    let all_features = features_enabled();
    let feat_chip: HashSet<_> = features_chip();

    let enabled_chip: Vec<_> = all_features.intersection(&feat_chip).collect();
    assert!(
        enabled_chip.len() < 2,
        "Too many chip features! Select one of {:?}",
        enabled_chip
    );

    if let Some(chip) = enabled_chip.get(0) {
        let feat_10xx = features_10xx();
        let feat_11xx = features_11xx();

        let family = if feat_10xx.contains(*chip) {
            assert!(!feat_11xx.contains(*chip));
            "imxrt10xx"
        } else if feat_11xx.contains(*chip) {
            assert!(!feat_10xx.contains(*chip));
            "imxrt11xx"
        } else {
            "none"
        };

        println!("cargo:rustc-cfg=family=\"{family}\"");
        println!("cargo:rustc-cfg=chip=\"{chip}\"");
    } else {
        println!("cargo:rustc-cfg=family=\"none\"");
        println!("cargo:rustc-cfg=chip=\"none\"");
    }
}