rust-lang/rust-bindgen is an automatic Rust binding generator for C and C++ libraries. It generates Rust FFI bindings to C and C++ libraries, allowing Rust programs to seamlessly interact with existing C/C++ code. This tool simplifies the process of integrating Rust with legacy codebases and external libraries.

Pros

• Automates the creation of Rust bindings, saving time and reducing manual errors
• Supports a wide range of C and C++ features, including complex types and templates
• Highly configurable, allowing fine-tuning of generated bindings
• Actively maintained and part of the official Rust project ecosystem

Cons

• May generate suboptimal or overly verbose bindings for complex C++ code
• Requires careful configuration for best results, which can be challenging for beginners
• Some advanced C++ features may not be fully supported or may require manual intervention
• Generated bindings may need additional manual tweaking for optimal Rust idiomatic usage

Code Examples

1. Basic usage with a C header file:

use std::path::PathBuf;

fn main() {
    let bindings = bindgen::Builder::default()
        .header("wrapper.h")
        .generate()
        .expect("Unable to generate bindings");

    let out_path = PathBuf::from("bindings.rs");
    bindings
        .write_to_file(out_path)
        .expect("Couldn't write bindings!");
}

2. Configuring bindgen for a specific library:

let bindings = bindgen::Builder::default()
    .header("libfoo.h")
    .allowlist_type("Foo")
    .allowlist_function("foo_.*")
    .generate()
    .expect("Unable to generate bindings");

3. Generating bindings with custom derives:

let bindings = bindgen::Builder::default()
    .header("my_library.h")
    .derive_debug(true)
    .derive_default(true)
    .generate()
    .expect("Unable to generate bindings");

Getting Started

1. Add bindgen to your Cargo.toml:

   [build-dependencies]
   bindgen = "0.64.0"
   

2. Create a build.rs file in your project root:

   use std::env;
   use std::path::PathBuf;
   
   fn main() {
       println!("cargo:rerun-if-changed=wrapper.h");
   
       let bindings = bindgen::Builder::default()
           .header("wrapper.h")
           .generate()
           .expect("Unable to generate bindings");
   
       let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
       bindings
           .write_to_file(out_path.join("bindings.rs"))
           .expect("Couldn't write bindings!");
   }
   

3. Include the generated bindings in your Rust code:

   #![allow(non_upper_case_globals)]
   #![allow(non_camel_case_types)]
   #![allow(non_snake_case)]
   
   include!(concat!(env!("OUT_DIR"), "/bindings.rs"));