wrapc

A zero-fuss, type-safe parser for rustc arguments, designed for RUSTC_WRAPPER tools.

wrapc parses rustc's notoriously complex CLI into strongly-typed Rust structs — with flawless round-trip reconstruction via Info::to_args().

Why not clap?

rustc's argument surface is unique:

• Mixed = and space-separated values (--edition=2021 vs -L native=/path)
• Complex sub-syntaxes (-l static:+bundle,+whole-archive=foo:bar)
• Nightly flags that appear/disappear without notice
• The RUSTC_WRAPPER protocol: <wrapper> - <rustc> <args...>

clap is too rigid for this. wrapc is purpose-built.

Quick Start

Add to your dependencies:

cargo add wrapc

Canonical wrapper skeleton:

use std::process::Command;
use wrapc::fetch;

fn main() {
    let info = fetch().expect("Failed to parse rustc arguments");
    
    // Inspect or mutate
    if info.crate_name.as_deref() == Some("legacy") {
        // inject flags, log, cache, etc.
    }
    
    // Reconstruct and execute
    let rustc = info.rustc.unwrap_or_else(|| "rustc".into());
    let status = Command::new(rustc).args(info.to_args()).status()?;
    std::process::exit(status.code().unwrap_or(1));
}

Documentation

Full API reference, protocol details, and advanced usage patterns are available in the book.

License

MIT OR Apache-2.0