build.rs

use std::{
    env,
    io::{self, Write},
};

fn main() {
    let lib_name = "go-geth-utils";
    let out_dir = env::var("OUT_DIR").unwrap();

    // Build
    let mut build = gobuild::Build::new();

    // Replace to a custom go-ethereum for scroll.
    #[cfg(feature = "scroll")]
    build.modfile("scroll.mod");

    if let Err(e) = build.file("./lib/lib.go").try_compile(lib_name) {
        // The error type is private so have to check the error string
        if format!("{}", e).starts_with("Failed to find tool.") {
            fail(
                " Failed to find Go. Please install Go 1.16 or later \
                following the instructions at https://golang.org/doc/install.
                On linux it is also likely available as a package."
                    .to_string(),
            );
        } else {
            fail(format!("{}", e));
        }
    }

    // Files the lib depends on that should recompile the lib
    let dep_files = vec![
        "./gethutil/asm.go",
        "./gethutil/trace.go",
        "./gethutil/util.go",
        "./go.mod",
        "./scroll.mod",
    ];
    for file in dep_files {
        println!("cargo:rerun-if-changed={}", file);
    }

    // Link
    println!("cargo:rustc-link-search=native={}", out_dir);
    println!("cargo:rustc-link-lib=static={}", lib_name);
}

fn fail(message: String) {
    let _ = writeln!(
        io::stderr(),
        "\n\nError while building geth-utils: {}\n\n",
        message
    );
    std::process::exit(1);
}