Witch of Git - jade-mouse/blob - toolchain/src/inst/test.rs

   1 use super::{Cond, Decode, Encode, Inst, Reg};
   2 use proptest::prelude::*;
   3 use std::{fmt::Debug, io::Cursor};
   4
   5 pub(super) fn regpair<T: Debug>(op: impl Fn(Reg, Reg) -> T) -> impl Strategy<Value = T> {
   6     (0..4u8, 1..4u8).prop_map(move |(a, b)| op(reg_num(a), reg_num(a + b)))
   7 }
   8
   9 fn reg_num(x: u8) -> Reg {
  10     match x & 0x3 {
  11         0 => Reg::R0,
  12         1 => Reg::R1,
  13         2 => Reg::R2,
  14         3 => Reg::R3,
  15         _ => unreachable!(),
  16     }
  17 }
  18
  19 proptest! {
  20     #[test]
  21     fn encoding_roundtrip(inst: Inst) {
  22         let mut buffer = [0, 0];
  23         let mut cursor = Cursor::new(&mut buffer[..]);
  24         inst.encode(&mut cursor).expect("Should encode instruction");
  25         let len = cursor.position();
  26         cursor.set_position(0);
  27         let out_inst = Inst::decode(&mut cursor)
  28             .expect(&format!("Should decode instruction bytes {:?}", cursor.get_ref()));
  29         let buffer = &buffer[..len as usize];
  30         prop_assert_eq!(inst, out_inst, "inst should round-trip the same. Encoded as {:x?}", buffer);
  31     }
  32 }