#bindings #ffi #code-generation

build bindgen

Automatically generates Rust FFI bindings to C and C++ libraries

96 releases (43 breaking)

0.58.1 Apr 6, 2021
0.57.0 Feb 1, 2021
0.56.0 Nov 26, 2020
0.54.1 Jul 6, 2020
0.0.2 Nov 21, 2014

#1 in FFI

Download history 74722/week @ 2021-01-21 77785/week @ 2021-01-28 75067/week @ 2021-02-04 73488/week @ 2021-02-11 82388/week @ 2021-02-18 82374/week @ 2021-02-25 82034/week @ 2021-03-04 83822/week @ 2021-03-11 83746/week @ 2021-03-18 86026/week @ 2021-03-25 73543/week @ 2021-04-01 89697/week @ 2021-04-08 88229/week @ 2021-04-15 90536/week @ 2021-04-22 81238/week @ 2021-04-29 71471/week @ 2021-05-06

330,281 downloads per month
Used in 1,894 crates (859 directly)


20K SLoC

crates.io docs.rs


bindgen automatically generates Rust FFI bindings to C (and some C++) libraries.

For example, given the C header doggo.h:

typedef struct Doggo {
    int many;
    char wow;
} Doggo;

void eleven_out_of_ten_majestic_af(Doggo* pupper);

bindgen produces Rust FFI code allowing you to call into the doggo library's functions and use its types:

/* automatically generated by rust-bindgen 0.99.9 */

pub struct Doggo {
    pub many: ::std::os::raw::c_int,
    pub wow: ::std::os::raw::c_char,

extern "C" {
    pub fn eleven_out_of_ten_majestic_af(pupper: *mut Doggo);

Users Guide

📚 Read the bindgen users guide here! 📚


The minimum supported Rust version is 1.40.

No MSRV bump policy has been established yet, so MSRV may increase in any release.

API Reference

API reference documentation is on docs.rs

Environment Variables

In addition to the library API and executable command-line API, bindgen can be controlled through environment variables.

End-users should set these environment variables to modify bindgen's behavior without modifying the source code of direct consumers of bindgen.

  • BINDGEN_EXTRA_CLANG_ARGS: extra arguments to pass to clang
    • Arguments are whitespace-separated
    • Use shell-style quoting to pass through whitespace
    • Examples:
      • Specify alternate sysroot: --sysroot=/path/to/sysroot
      • Add include search path with spaces: -I"/path/with spaces"

Additionally, bindgen uses libclang to parse C and C++ header files. To modify how bindgen searches for libclang, see the clang-sys documentation. For more details on how bindgen uses libclang, see the bindgen users guide.


We don't follow a specific release calendar, but if you need a release please file an issue requesting that (ping @emilio for increased effectiveness).


See CONTRIBUTING.md for hacking on bindgen!


~77K SLoC