lightning-sys

Safe gnu lightning bindings for rust

GNU lightning version

This crate links explicitly against its own packaged copy of lightning-2.1.3.

MSRV

The minimum supported Rust version is 1.39.

Examples

a function that increments a number by one

```rust use lightning_sys::{Jit, Reg, JitPointer, JitWord};

let mut jit = Jit::new(); let mut js = jit.new_state();

js.prolog(); let inarg = js.arg(); js.getarg(Reg::R(0), &inarg); js.addi(Reg::R(0), Reg::R(0), 1); js.retr(Reg::R(0));

let incr = unsafe { js.emit:: JitWord>() }; js.clear();

asserteq!(incr(5), 6); asserteq!(incr(6), 7);

```

A simple function call to printf

```rust extern crate libc;

use std::ffi::CString; use lightning_sys::{Jit, JitWord, Reg, JitPointer}; use std::convert::TryInto;

fn main() { let mut jit = Jit::new(); let mut js = jit.new_state();

// make sure this outlives any calls
let cs = CString::new("generated %d bytes\n").unwrap();

let start = js.note(file!(), line!());
js.prolog();
let inarg = js.arg();
js.getarg(Reg::R(1), &inarg);
js.prepare();
js.pushargi(cs.as_ptr() as JitWord);
js.ellipsis();
js.pushargr(Reg::R(1));
js.finishi(libc::printf as JitPointer);
js.ret();
js.epilog();
let end = js.note(file!(), line!());

let my_function = unsafe{ js.emit::<extern fn(JitWord)>() };
/* call the generated code, passing its size as argument */
my_function((js.address(&end) as u64 - js.address(&start) as u64).try_into().unwrap());
js.clear();

// TODO: dissasembly has not been implemented yet
// js.dissasemble();

}

```

Fibonacci numbers

```rust use lightning_sys::{Jit, JitWord, Reg, JitPointer, NULL};

fn main() { let mut jit = Jit::new(); let mut js = jit.new_state();

let label = js.label();
            js.prolog();
let inarg = js.arg();
            js.getarg(Reg::R(0), &inarg);
let zero  = js.beqi(Reg::R(0), 0);
            js.movr(Reg::V(0), Reg::R(0));
            js.movi(Reg::R(0), 1);
let refr  = js.blei(Reg::V(0), 2);
            js.subi(Reg::V(1), Reg::V(0), 1);
            js.subi(Reg::V(2), Reg::V(0), 2);
            js.prepare();
            js.pushargr(Reg::V(1));
let call  = js.finishi(NULL);
            js.patch_at(&call, &label);
            js.retval(Reg::V(1));
            js.prepare();
            js.pushargr(Reg::V(2));
let call2 = js.finishi(NULL);
            js.patch_at(&call2, &label);
            js.retval(Reg::R(0));
            js.addr(Reg::R(0), Reg::R(0), Reg::V(1));

            js.patch(&refr);
            js.patch(&zero);
            js.retr(Reg::R(0));
            js.epilog();

let fib = unsafe{ js.emit::<extern fn(JitWord) -> JitWord>() };
js.clear();

println!("fib({})={}", 32, fib(32));
assert_eq!(0, fib(0));
assert_eq!(1, fib(1));
assert_eq!(1, fib(2));
assert_eq!(2178309, fib(32));

} ```

Tail Call Optimized factorial

```rust use lightning_sys::{Jit, JitWord, Reg, NULL};

fn main() { let mut jit = Jit::new(); let mut js = jit.new_state();

let fact = js.forward();

            js.prolog();
let inarg = js.arg();
            js.getarg(Reg::R(0), &inarg);
            js.prepare();
            js.pushargi(1);
            js.pushargr(Reg::R(0));
let call  = js.finishi(NULL);
            js.patch_at(&call, &fact);

            js.retval(Reg::R(0));
            js.retr(Reg::R(0));
            js.epilog();

js.link(&fact);
            js.prolog();
            js.frame(16);
let f_ent = js.label(); // TCO entry point
let ac    = js.arg();
let ina   = js.arg();
            js.getarg(Reg::R(0), &ac);
            js.getarg(Reg::R(1), &ina);
let f_out = js.blei(Reg::R(1), 1);
            js.mulr(Reg::R(0), Reg::R(0), Reg::R(1));
            js.putargr(Reg::R(0), &ac);
            js.subi(Reg::R(1), Reg::R(1), 1);
            js.putargr(Reg::R(1), &ina);
let jump  = js.jmpi(); // tail call optimiation
            js.patch_at(&jump, &f_ent);
            js.patch(&f_out);
            js.retr(Reg::R(0));

let factorial = unsafe{ js.emit::<extern fn(JitWord) -> JitWord>() };
js.clear();

println!("factorial({}) = {}", 5, factorial(5));

} ```