rust/compiler/rustc_serialize/tests/opaque.rs
Nicholas Nethercote 416399dc10 Make Decodable and Decoder infallible.
`Decoder` has two impls:
- opaque: this impl is already partly infallible, i.e. in some places it
  currently panics on failure (e.g. if the input is too short, or on a
  bad `Result` discriminant), and in some places it returns an error
  (e.g. on a bad `Option` discriminant). The number of places where
  either happens is surprisingly small, just because the binary
  representation has very little redundancy and a lot of input reading
  can occur even on malformed data.
- json: this impl is fully fallible, but it's only used (a) for the
  `.rlink` file production, and there's a `FIXME` comment suggesting it
  should change to a binary format, and (b) in a few tests in
  non-fundamental ways. Indeed #85993 is open to remove it entirely.

And the top-level places in the compiler that call into decoding just
abort on error anyway. So the fallibility is providing little value, and
getting rid of it leads to some non-trivial performance improvements.

Much of this commit is pretty boring and mechanical. Some notes about
a few interesting parts:
- The commit removes `Decoder::{Error,error}`.
- `InternIteratorElement::intern_with`: the impl for `T` now has the same
  optimization for small counts that the impl for `Result<T, E>` has,
  because it's now much hotter.
- Decodable impls for SmallVec, LinkedList, VecDeque now all use
  `collect`, which is nice; the one for `Vec` uses unsafe code, because
  that gave better perf on some benchmarks.
2022-01-22 10:38:31 +11:00

277 lines
5.5 KiB
Rust

#![allow(rustc::internal)]
use rustc_macros::{Decodable, Encodable};
use rustc_serialize::opaque::{Decoder, Encoder};
use rustc_serialize::{Decodable, Encodable};
use std::fmt::Debug;
#[derive(PartialEq, Clone, Debug, Encodable, Decodable)]
struct Struct {
a: (),
b: u8,
c: u16,
d: u32,
e: u64,
f: usize,
g: i8,
h: i16,
i: i32,
j: i64,
k: isize,
l: char,
m: String,
n: f32,
o: f64,
p: bool,
q: Option<u32>,
}
fn check_round_trip<T: Encodable<Encoder> + for<'a> Decodable<Decoder<'a>> + PartialEq + Debug>(
values: Vec<T>,
) {
let mut encoder = Encoder::new(Vec::new());
for value in &values {
Encodable::encode(value, &mut encoder).unwrap();
}
let data = encoder.into_inner();
let mut decoder = Decoder::new(&data[..], 0);
for value in values {
let decoded = Decodable::decode(&mut decoder);
assert_eq!(value, decoded);
}
}
#[test]
fn test_unit() {
check_round_trip(vec![(), (), (), ()]);
}
#[test]
fn test_u8() {
let mut vec = vec![];
for i in u8::MIN..u8::MAX {
vec.push(i);
}
check_round_trip(vec);
}
#[test]
fn test_u16() {
for i in u16::MIN..u16::MAX {
check_round_trip(vec![1, 2, 3, i, i, i]);
}
}
#[test]
fn test_u32() {
check_round_trip(vec![1, 2, 3, u32::MIN, 0, 1, u32::MAX, 2, 1]);
}
#[test]
fn test_u64() {
check_round_trip(vec![1, 2, 3, u64::MIN, 0, 1, u64::MAX, 2, 1]);
}
#[test]
fn test_usize() {
check_round_trip(vec![1, 2, 3, usize::MIN, 0, 1, usize::MAX, 2, 1]);
}
#[test]
fn test_i8() {
let mut vec = vec![];
for i in i8::MIN..i8::MAX {
vec.push(i);
}
check_round_trip(vec);
}
#[test]
fn test_i16() {
for i in i16::MIN..i16::MAX {
check_round_trip(vec![-1, 2, -3, i, i, i, 2]);
}
}
#[test]
fn test_i32() {
check_round_trip(vec![-1, 2, -3, i32::MIN, 0, 1, i32::MAX, 2, 1]);
}
#[test]
fn test_i64() {
check_round_trip(vec![-1, 2, -3, i64::MIN, 0, 1, i64::MAX, 2, 1]);
}
#[test]
fn test_isize() {
check_round_trip(vec![-1, 2, -3, isize::MIN, 0, 1, isize::MAX, 2, 1]);
}
#[test]
fn test_bool() {
check_round_trip(vec![false, true, true, false, false]);
}
#[test]
fn test_f32() {
let mut vec = vec![];
for i in -100..100 {
vec.push((i as f32) / 3.0);
}
check_round_trip(vec);
}
#[test]
fn test_f64() {
let mut vec = vec![];
for i in -100..100 {
vec.push((i as f64) / 3.0);
}
check_round_trip(vec);
}
#[test]
fn test_char() {
let vec = vec!['a', 'b', 'c', 'd', 'A', 'X', ' ', '#', 'Ö', 'Ä', 'µ', '€'];
check_round_trip(vec);
}
#[test]
fn test_string() {
let vec = vec![
"abcbuÖeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmeabpnvapeapmaebn".to_string(),
"abcbuÖganeiÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µnvapeapmaebn".to_string(),
];
check_round_trip(vec);
}
#[test]
fn test_option() {
check_round_trip(vec![Some(-1i8)]);
check_round_trip(vec![Some(-2i16)]);
check_round_trip(vec![Some(-3i32)]);
check_round_trip(vec![Some(-4i64)]);
check_round_trip(vec![Some(-5isize)]);
let none_i8: Option<i8> = None;
check_round_trip(vec![none_i8]);
let none_i16: Option<i16> = None;
check_round_trip(vec![none_i16]);
let none_i32: Option<i32> = None;
check_round_trip(vec![none_i32]);
let none_i64: Option<i64> = None;
check_round_trip(vec![none_i64]);
let none_isize: Option<isize> = None;
check_round_trip(vec![none_isize]);
}
#[test]
fn test_struct() {
check_round_trip(vec![Struct {
a: (),
b: 10,
c: 11,
d: 12,
e: 13,
f: 14,
g: 15,
h: 16,
i: 17,
j: 18,
k: 19,
l: 'x',
m: "abc".to_string(),
n: 20.5,
o: 21.5,
p: false,
q: None,
}]);
check_round_trip(vec![Struct {
a: (),
b: 101,
c: 111,
d: 121,
e: 131,
f: 141,
g: -15,
h: -16,
i: -17,
j: -18,
k: -19,
l: 'y',
m: "def".to_string(),
n: -20.5,
o: -21.5,
p: true,
q: Some(1234567),
}]);
}
#[derive(PartialEq, Clone, Debug, Encodable, Decodable)]
enum Enum {
Variant1,
Variant2(usize, f32),
Variant3 { a: i32, b: char, c: bool },
}
#[test]
fn test_enum() {
check_round_trip(vec![
Enum::Variant1,
Enum::Variant2(1, 2.5),
Enum::Variant3 { a: 3, b: 'b', c: false },
Enum::Variant3 { a: -4, b: 'f', c: true },
]);
}
#[test]
fn test_sequence() {
let mut vec = vec![];
for i in -100i64..100i64 {
vec.push(i * 100000);
}
check_round_trip(vec![vec]);
}
#[test]
fn test_hash_map() {
use std::collections::HashMap;
let mut map = HashMap::new();
for i in -100i64..100i64 {
map.insert(i * 100000, i * 10000);
}
check_round_trip(vec![map]);
}
#[test]
fn test_tuples() {
check_round_trip(vec![('x', (), false, 0.5f32)]);
check_round_trip(vec![(9i8, 10u16, 1.5f64)]);
check_round_trip(vec![(-12i16, 11u8, 12usize)]);
check_round_trip(vec![(1234567isize, 100000000000000u64, 99999999999999i64)]);
check_round_trip(vec![(String::new(), "some string".to_string())]);
}