1 # Integrating Automatically Generated FFI Bindings

     2 

     3 There are a number of tools to automatically generate bindings between Rust and different

     4 foreign languages.

     5 

     6 1. [bindgen](#bindgen)

     7 2. [cbindgen](#cbindgen-integration)

     8 3. [cxx](#cxx-integration)

     9 

    10 ## bindgen

    11 

    12 [bindgen] is a tool to automatically generate Rust bindings from C headers.

    13 As such, integrating bindgen [via a build-script](https://rust-lang.github.io/rust-bindgen/library-usage.html)

    14 works well and their doesn't seem to be a need to create CMake rules for 

    15 generating the bindings.

    16 

    17 [bindgen]: https://github.com/rust-lang/rust-bindgen

    18 

    19 ## cbindgen integration

    20 

    21 ⚠️⚠️⚠️ **EXPERIMENTAL** ⚠️⚠️⚠️

    22 

    23 [cbindgen] is a tool that generates C/C++ headers from Rust code. When compiling C/C++

    24 code that `#include`s such generated headers the buildsystem must be aware of the dependencies.

    25 Generating the headers via a build-script is possible, but Corrosion offers no guidance here.

    26 

    27 Instead, Corrosion offers an experimental function to add CMake rules using cbindgen to generate

    28 the headers.

    29 This is not available on a stable released version yet, and the details are subject to change.

    30 {{#include ../../cmake/Corrosion.cmake:corrosion_cbindgen}}

    31 

    32 ### Current limitations

    33 

    34 - The current version regenerates the bindings more often then necessary to be on the safe side,

    35   but an upstream PR is open to solve this in a future cbindgen version.

    36 

    37 ## cxx integration

    38 

    39 ⚠️⚠️⚠️ **EXPERIMENTAL** ⚠️⚠️⚠️

    40 

    41 [cxx] is a tool which generates bindings for C++/Rust interop.

    42 

    43 {{#include ../../cmake/Corrosion.cmake:corrosion_add_cxxbridge}}