Tuesday, 26 April 2016

Call Rust from NodeJS via cross-platform C ABI with RuNo bridge

The RuNo bridge is a command line tool which generates C++ code for NodeJS addon from Rust code or from JSON definition (with JSON definition it should work with any C ABI compatible library, of course when implemented functionality is enough).

I've implemeted this tool after my last research on calling Rust from Node JS.

The parser of RuNo bridge does not do magical deep analysis of code, it just detects the following signatures in your code:


pub extern "C" fn ...

it does not require any C++ knowledge from developer if you use primitives mentioned above and your Rust ABI interface complies with simple requirements:

  • All your ABI functoins should be listed in one Rust file;
  • Your library should use crate libc;
  • Each ABI function should be preceeded with #[no_mangle];
  • Each ABI function should be prefixed with pub extern "C";
  • ABI Functions should only take params of c_int,c_float,c_double or *c_char (as a C string with EOF);
  • ABI Functions should return either one of c_int,c_float,c_double or *c_char (as a C string with EOF)
It is tested on Windows, Mac OS and Ubuntu, however it has some limitations developer should know:

The package itself does not need Rust or C++ with node-gyp, it just emits a C++ source file.

However in order to build the source code, rust and C++ compiler should be compatible with NodeJS version installed. It is particularly important on Windows, where Rust target should be MSVC not GNU. For example, if one using 32 bit NodeJS on Windows this one should use target i686-pc-windows-msvc, if 64 bit Node then Rust should be configured with x86_64-pc-windows-msvc compile target. The same about C++: Everything is mostrly smooth on platforms with GCC, and a bit painful with MS Visual C++, please refer to node-gyp installation instructions for details.

You can find simple usage examples on the github: https://github.com/andruhon/runo-bridge-example

I will appreciate any comments or contribution.