Using rust with other languages (like C)

What is FFI?

https://spin.atomicobject.com/ffi-foreign-function-interfaces/

In depth example for C ffi from Rusto

https://doc.rust-lang.org/nomicon/ffi.html

Build C files you can call from your rust code

Using this crate: https://crates.io/crates/cc

// build.rs  - build step to compile the c files

fn main() {
    cc::Build::new()
        .file("foo.c")
        .file("bar.c")
        .compile("foo");
}

// call the c code from your rust app like this
extern "C" {
// basically just providing input/output types?
    fn foo_function();
    fn bar_function(x: i32) -> i32;
}

pub fn call() {
    unsafe {
        foo_function();
        bar_function(42);
    }
}

Debugging ffi

https://github.com/rust-lang/miri https://stackoverflow.com/questions/39204908/how-to-check-release-debug-builds-using-cfg-in-rust

More reading:

https://doc.rust-lang.org/nomicon/ffi.html

https://www.reddit.com/r/rust/comments/511c1h/linking_objectivec_to_rust/ https://doc.rust-lang.org/std/keyword.extern.html

https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html#using-extern-functions-to-call-external-code

Required reading

https://doc.rust-lang.org/cargo/reference/build-scripts.html