build.rs

#![warn(clippy::pedantic)]

extern crate cbindgen;

use std::env;

fn main() {
    if std::env::var("DOCS_RS").is_ok() {
        // exit the build script early on docs.rs because cbindgen needs network access
        return;
    }

    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();

    // Generate C-API header
    cbindgen::Builder::new()
        .with_config(
            cbindgen::Config::from_file(format!("{crate_dir}/cbindgen.toml"))
                .expect("could not read cbindgen.toml"),
        )
        .with_crate(crate_dir)
        .with_after_include(format!(
            "#define RUSTSAT_VERSION {version}
#define RUSTSAT_VERSION_MAJOR {major}
#define RUSTSAT_VERSION_MINOR {minor}
#define RUSTSAT_VERSION_PATCH {patch}",
            version = env!("CARGO_PKG_VERSION"),
            major = env!("CARGO_PKG_VERSION_MAJOR"),
            minor = env!("CARGO_PKG_VERSION_MINOR"),
            patch = env!("CARGO_PKG_VERSION_PATCH"),
        ))
        .generate()
        .expect("Unable to generate bindings")
        .write_to_file("rustsat.h");

    println!("cargo:rerun-if-changed=cbindgen.toml");
    println!("cargo:rerun-if-changed=Cargo.toml");
    println!("cargo:rerun-if-changed=src/");

    // Setup inline-c
    let include_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let ld_dir = target_dir().unwrap();

    let cflags = format!("-I{include_dir} -D_DEBUG -D_CRT_SECURE_NO_WARNINGS");
    println!("cargo:rustc-env=INLINE_C_RS_CFLAGS={cflags}");

    let ldflags = format!("-L{L} -lrustsat_capi", L = ld_dir.to_string_lossy());
    let ldflags = format!("{ldflags} -llzma -lbz2");
    println!("cargo:rustc-env=INLINE_C_RS_LDFLAGS={ldflags}");
}

// https://github.com/rust-lang/cargo/issues/9661#issuecomment-1722358176
fn target_dir() -> Result<std::path::PathBuf, Box<dyn std::error::Error>> {
    let out_dir = std::path::PathBuf::from(std::env::var("OUT_DIR")?);
    let profile = std::env::var("PROFILE")?;
    let mut target_dir = None;
    let mut sub_path = out_dir.as_path();
    while let Some(parent) = sub_path.parent() {
        if parent.ends_with(&profile) {
            target_dir = Some(parent);
            break;
        }
        sub_path = parent;
    }
    let target_dir = target_dir.ok_or("not found")?;
    Ok(target_dir.to_path_buf())
}