Understanding rustc and cargo

Understanding rustc and cargo

While rustc is the underlying compiler, production Rust projects are almost exclusively managed with Cargo.

The Role of Cargo

Cargo handles four essential engineering responsibilities: 1. Dependency Resolution: Downloading, pinning, and compiling external crates from crates.io. 2. Build Orchestration: Invoking rustc with optimal optimization flags, link arguments, and target settings. 3. Test & Benchmark Execution: Discovering and executing unit tests, integration tests, and performance benchmarks. 4. Documentation Generation: Generating standard HTML documentation directly from doc-comments.

Common Cargo Commands

cargo check   # Fast syntax and type verification without binary emission
cargo build   # Compile debug build with symbols into target/debug
cargo run     # Build and execute the binary
cargo test    # Run automated test harness
cargo doc     # Build HTML documentation for current project and dependencies