rust/compiler/rustc_serialize/tests/leb128.rs
2021-03-24 22:34:36 +01:00

94 lines
3.5 KiB
Rust

#![feature(maybe_uninit_slice)]
#![feature(maybe_uninit_uninit_array)]
use rustc_serialize::leb128::*;
use std::mem::MaybeUninit;
macro_rules! impl_test_unsigned_leb128 {
($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
#[test]
fn $test_name() {
// Test 256 evenly spaced values of integer range,
// integer max value, and some "random" numbers.
let mut values = Vec::new();
let increment = (1 as $int_ty) << ($int_ty::BITS - 8);
values.extend((0..256).map(|i| $int_ty::MIN + i * increment));
values.push($int_ty::MAX);
values.extend(
(-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFu64 as $int_ty)),
);
let mut stream = Vec::new();
for &x in &values {
let mut buf = MaybeUninit::uninit_array();
stream.extend($write_fn_name(&mut buf, x));
}
let mut position = 0;
for &expected in &values {
let (actual, bytes_read) = $read_fn_name(&stream[position..]);
assert_eq!(expected, actual);
position += bytes_read;
}
assert_eq!(stream.len(), position);
}
};
}
impl_test_unsigned_leb128!(test_u16_leb128, write_u16_leb128, read_u16_leb128, u16);
impl_test_unsigned_leb128!(test_u32_leb128, write_u32_leb128, read_u32_leb128, u32);
impl_test_unsigned_leb128!(test_u64_leb128, write_u64_leb128, read_u64_leb128, u64);
impl_test_unsigned_leb128!(test_u128_leb128, write_u128_leb128, read_u128_leb128, u128);
impl_test_unsigned_leb128!(test_usize_leb128, write_usize_leb128, read_usize_leb128, usize);
macro_rules! impl_test_signed_leb128 {
($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
#[test]
fn $test_name() {
// Test 256 evenly spaced values of integer range,
// integer max value, and some "random" numbers.
let mut values = Vec::new();
let mut value = $int_ty::MIN;
let increment = (1 as $int_ty) << ($int_ty::BITS - 8);
for _ in 0..256 {
values.push(value);
// The addition in the last loop iteration overflows.
value = value.wrapping_add(increment);
}
values.push($int_ty::MAX);
values.extend(
(-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFi64 as $int_ty)),
);
let mut stream = Vec::new();
for &x in &values {
let mut buf = MaybeUninit::uninit_array();
stream.extend($write_fn_name(&mut buf, x));
}
let mut position = 0;
for &expected in &values {
let (actual, bytes_read) = $read_fn_name(&stream[position..]);
assert_eq!(expected, actual);
position += bytes_read;
}
assert_eq!(stream.len(), position);
}
};
}
impl_test_signed_leb128!(test_i16_leb128, write_i16_leb128, read_i16_leb128, i16);
impl_test_signed_leb128!(test_i32_leb128, write_i32_leb128, read_i32_leb128, i32);
impl_test_signed_leb128!(test_i64_leb128, write_i64_leb128, read_i64_leb128, i64);
impl_test_signed_leb128!(test_i128_leb128, write_i128_leb128, read_i128_leb128, i128);
impl_test_signed_leb128!(test_isize_leb128, write_isize_leb128, read_isize_leb128, isize);