hi-ffi

Tool for generating bindings to Rust code.

How To Use

Rust glue code and bindings in target languages are generated for Rust code that is marked with the #[ffi] macro.

use hi_ffi::ffi;

#[ffi]
#[derive(Default, Clone)]
struct TestStruct {
    // generate getter and setter
    #[ffi(setter, getter)]
    i32_field: i32,

    // generate getter only
    #[ffi(getter)]
    bool_field: bool,

    // generate getter and setter
    pub string_field: String,

    // don't generate getter and setter
    #[ffi(skip)]
    _skip_field: i32,

    #[ffi(getter, setter)]
    struct_field: TestStruct2,
}

#[ffi]
#[derive(Default, Clone)]
struct TestStruct2 {
    pub i32_field: i32,
}

#[ffi]
fn function_with_primitive_and_string_arg(_i: i32, _b: bool, _s: String) {}

After building Rust package, the FFI code is generated in generated_code directory, which then can be embedded into a program written in one of target languages.

Language specific examples:

The following examples are built on top of the Rust code defined here.

• C++:
  • README.md
  • main.cpp
• Swift
  • README.md
  • main.swift

Supported Features

		c++	swift
structs	primitive setters	✅	✅
	primitive getters	✅	✅
	string setters	✅	✅
	string getters	✅	✅
	struct getters	✅	❌
	struct setters	✅	❌
	default constructor	✅	✅
methods	primitive arguments	✅	✅
	string arguments	✅	✅
	primitive return	✅	✅
	string return	✅	✅
	struct arguments	❌	❌
	struct return	❌	❌
static methods	primitive arguments	✅	✅
	string arguments	✅	✅
	primitive return	✅	✅
	string return	✅	✅
	struct arguments	❌	❌
	struct return	❌	❌
functions	primitive arguments	✅	✅
	string arguments	✅	✅
	primitive return	✅	✅
	string return	✅	✅
	str return	❌	❌
	struct arguments	❌	❌
	struct return	❌	❌
enums	primitive enums	❌	❌
	variants with primitives	❌	❌
	variants with strings	❌	❌
	variants with structs	❌	❌
vector	primitives vector	❌	❌
	strings vector	❌	❌

Development

Modules

hi_ffi contains of the following modules:

• lib.rs - main module, creates target files and directories, calls translator and wrapper modules
• translator - translates Rust code into parsed, intermediate representation; it is target language agnostic
• wrapper - result of translation. it is used for generating Rust glue code (Into<TokenStream>) and bindings for every target language
• language specific base modules (cpp, swift) - generates base code for each target language

TODO

• pipelines
  • publishing to crates.io