rust-clippy/tests/ui/for_loop.rs
2017-09-16 18:53:55 -04:00

550 lines
11 KiB
Rust

#![feature(plugin, inclusive_range_syntax)]
#![plugin(clippy)]
use std::collections::*;
use std::rc::Rc;
static STATIC: [usize; 4] = [0, 1, 8, 16];
const CONST: [usize; 4] = [0, 1, 8, 16];
#[warn(clippy)]
fn for_loop_over_option_and_result() {
let option = Some(1);
let result = option.ok_or("x not found");
let v = vec![0, 1, 2];
// check FOR_LOOP_OVER_OPTION lint
for x in option {
println!("{}", x);
}
// check FOR_LOOP_OVER_RESULT lint
for x in result {
println!("{}", x);
}
for x in option.ok_or("x not found") {
println!("{}", x);
}
// make sure LOOP_OVER_NEXT lint takes precedence when next() is the last call
// in the chain
for x in v.iter().next() {
println!("{}", x);
}
// make sure we lint when next() is not the last call in the chain
for x in v.iter().next().and(Some(0)) {
println!("{}", x);
}
for x in v.iter().next().ok_or("x not found") {
println!("{}", x);
}
// check for false positives
// for loop false positive
for x in v {
println!("{}", x);
}
// while let false positive for Option
while let Some(x) = option {
println!("{}", x);
break;
}
// while let false positive for Result
while let Ok(x) = result {
println!("{}", x);
break;
}
}
struct Unrelated(Vec<u8>);
impl Unrelated {
fn next(&self) -> std::slice::Iter<u8> {
self.0.iter()
}
fn iter(&self) -> std::slice::Iter<u8> {
self.0.iter()
}
}
#[warn(needless_range_loop, explicit_iter_loop, explicit_into_iter_loop, iter_next_loop, reverse_range_loop,
explicit_counter_loop, for_kv_map)]
#[warn(unused_collect)]
#[allow(linkedlist, shadow_unrelated, unnecessary_mut_passed, cyclomatic_complexity, similar_names)]
#[allow(many_single_char_names, unused_variables)]
fn main() {
const MAX_LEN: usize = 42;
let mut vec = vec![1, 2, 3, 4];
let vec2 = vec![1, 2, 3, 4];
for i in 0..vec.len() {
println!("{}", vec[i]);
}
for i in 0..vec.len() {
let i = 42; // make a different `i`
println!("{}", vec[i]); // ok, not the `i` of the for-loop
}
for i in 0..vec.len() {
let _ = vec[i];
}
// ICE #746
for j in 0..4 {
println!("{:?}", STATIC[j]);
}
for j in 0..4 {
println!("{:?}", CONST[j]);
}
for i in 0..vec.len() {
println!("{} {}", vec[i], i);
}
for i in 0..vec.len() {
// not an error, indexing more than one variable
println!("{} {}", vec[i], vec2[i]);
}
for i in 0..vec.len() {
println!("{}", vec2[i]);
}
for i in 5..vec.len() {
println!("{}", vec[i]);
}
for i in 0..MAX_LEN {
println!("{}", vec[i]);
}
for i in 0...MAX_LEN {
println!("{}", vec[i]);
}
for i in 5..10 {
println!("{}", vec[i]);
}
for i in 5...10 {
println!("{}", vec[i]);
}
for i in 5..vec.len() {
println!("{} {}", vec[i], i);
}
for i in 5..10 {
println!("{} {}", vec[i], i);
}
for i in 10..0 {
println!("{}", i);
}
for i in 10...0 {
println!("{}", i);
}
for i in MAX_LEN..0 {
println!("{}", i);
}
for i in 5..5 {
println!("{}", i);
}
for i in 5...5 {
// not an error, this is the range with only one element “5”
println!("{}", i);
}
for i in 0..10 {
// not an error, the start index is less than the end index
println!("{}", i);
}
for i in -10..0 {
// not an error
println!("{}", i);
}
for i in (10..0).map(|x| x * 2) {
// not an error, it can't be known what arbitrary methods do to a range
println!("{}", i);
}
// testing that the empty range lint folds constants
for i in 10..5 + 4 {
println!("{}", i);
}
for i in (5 + 2)..(3 - 1) {
println!("{}", i);
}
for i in (5 + 2)..(8 - 1) {
println!("{}", i);
}
for i in (2 * 2)..(2 * 3) {
// no error, 4..6 is fine
println!("{}", i);
}
let x = 42;
for i in x..10 {
// no error, not constant-foldable
println!("{}", i);
}
// See #601
for i in 0..10 {
// no error, id_col does not exist outside the loop
let mut id_col = vec![0f64; 10];
id_col[i] = 1f64;
}
for _v in vec.iter() {}
for _v in vec.iter_mut() {}
let out_vec = vec![1, 2, 3];
for _v in out_vec.into_iter() {}
let array = [1, 2, 3];
for _v in array.into_iter() {}
for _v in &vec {} // these are fine
for _v in &mut vec {} // these are fine
for _v in [1, 2, 3].iter() {}
for _v in (&mut [1, 2, 3]).iter() {} // no error
for _v in [0; 32].iter() {}
for _v in [0; 33].iter() {} // no error
let ll: LinkedList<()> = LinkedList::new();
for _v in ll.iter() {}
let vd: VecDeque<()> = VecDeque::new();
for _v in vd.iter() {}
let bh: BinaryHeap<()> = BinaryHeap::new();
for _v in bh.iter() {}
let hm: HashMap<(), ()> = HashMap::new();
for _v in hm.iter() {}
let bt: BTreeMap<(), ()> = BTreeMap::new();
for _v in bt.iter() {}
let hs: HashSet<()> = HashSet::new();
for _v in hs.iter() {}
let bs: BTreeSet<()> = BTreeSet::new();
for _v in bs.iter() {}
for _v in vec.iter().next() {}
let u = Unrelated(vec![]);
for _v in u.next() {} // no error
for _v in u.iter() {} // no error
let mut out = vec![];
vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>();
let _y = vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>(); // this is fine
// Loop with explicit counter variable
let mut _index = 0;
for _v in &vec {
_index += 1
}
let mut _index = 1;
_index = 0;
for _v in &vec {
_index += 1
}
// Potential false positives
let mut _index = 0;
_index = 1;
for _v in &vec {
_index += 1
}
let mut _index = 0;
_index += 1;
for _v in &vec {
_index += 1
}
let mut _index = 0;
if true {
_index = 1
}
for _v in &vec {
_index += 1
}
let mut _index = 0;
let mut _index = 1;
for _v in &vec {
_index += 1
}
let mut _index = 0;
for _v in &vec {
_index += 1;
_index += 1
}
let mut _index = 0;
for _v in &vec {
_index *= 2;
_index += 1
}
let mut _index = 0;
for _v in &vec {
_index = 1;
_index += 1
}
let mut _index = 0;
for _v in &vec {
let mut _index = 0;
_index += 1
}
let mut _index = 0;
for _v in &vec {
_index += 1;
_index = 0;
}
let mut _index = 0;
for _v in &vec {
for _x in 0..1 {
_index += 1;
}
_index += 1
}
let mut _index = 0;
for x in &vec {
if *x == 1 {
_index += 1
}
}
let mut _index = 0;
if true {
_index = 1
};
for _v in &vec {
_index += 1
}
let mut _index = 1;
if false {
_index = 0
};
for _v in &vec {
_index += 1
}
let mut index = 0;
{
let mut _x = &mut index;
}
for _v in &vec {
_index += 1
}
let mut index = 0;
for _v in &vec {
index += 1
}
println!("index: {}", index);
for_loop_over_option_and_result();
let m: HashMap<u64, u64> = HashMap::new();
for (_, v) in &m {
let _v = v;
}
let m: Rc<HashMap<u64, u64>> = Rc::new(HashMap::new());
for (_, v) in &*m {
let _v = v;
// Here the `*` is not actually necesarry, but the test tests that we don't
// suggest
// `in *m.values()` as we used to
}
let mut m: HashMap<u64, u64> = HashMap::new();
for (_, v) in &mut m {
let _v = v;
}
let m: &mut HashMap<u64, u64> = &mut HashMap::new();
for (_, v) in &mut *m {
let _v = v;
}
let m: HashMap<u64, u64> = HashMap::new();
let rm = &m;
for (k, _value) in rm {
let _k = k;
}
test_for_kv_map();
fn f<T>(_: &T, _: &T) -> bool {
unimplemented!()
}
fn g<T>(_: &mut [T], _: usize, _: usize) {
unimplemented!()
}
for i in 1..vec.len() {
if f(&vec[i - 1], &vec[i]) {
g(&mut vec, i - 1, i);
}
}
for mid in 1..vec.len() {
let (_, _) = vec.split_at(mid);
}
}
#[allow(used_underscore_binding)]
fn test_for_kv_map() {
let m: HashMap<u64, u64> = HashMap::new();
// No error, _value is actually used
for (k, _value) in &m {
let _ = _value;
let _k = k;
}
}
#[allow(dead_code)]
fn partition<T: PartialOrd + Send>(v: &mut [T]) -> usize {
let pivot = v.len() - 1;
let mut i = 0;
for j in 0..pivot {
if v[j] <= v[pivot] {
v.swap(i, j);
i += 1;
}
}
v.swap(i, pivot);
i
}
const LOOP_OFFSET: usize = 5000;
#[warn(needless_range_loop)]
pub fn manual_copy(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) {
// plain manual memcpy
for i in 0..src.len() {
dst[i] = src[i];
}
// dst offset memcpy
for i in 0..src.len() {
dst[i + 10] = src[i];
}
// src offset memcpy
for i in 0..src.len() {
dst[i] = src[i + 10];
}
// src offset memcpy
for i in 11..src.len() {
dst[i] = src[i - 10];
}
// overwrite entire dst
for i in 0..dst.len() {
dst[i] = src[i];
}
// manual copy with branch - can't easily convert to memcpy!
for i in 0..src.len() {
dst[i] = src[i];
if dst[i] > 5 {
break;
}
}
// multiple copies - suggest two memcpy statements
for i in 10..256 {
dst[i] = src[i - 5];
dst2[i + 500] = src[i]
}
// this is a reversal - the copy lint shouldn't be triggered
for i in 10..LOOP_OFFSET {
dst[i + LOOP_OFFSET] = src[LOOP_OFFSET - i];
}
let some_var = 5;
// Offset in variable
for i in 10..LOOP_OFFSET {
dst[i + LOOP_OFFSET] = src[i - some_var];
}
// Non continuous copy - don't trigger lint
for i in 0..10 {
dst[i + i] = src[i];
}
let src_vec = vec![1, 2, 3, 4, 5];
let mut dst_vec = vec![0, 0, 0, 0, 0];
// make sure vectors are supported
for i in 0..src_vec.len() {
dst_vec[i] = src_vec[i];
}
// lint should not trigger when either
// source or destination type is not
// slice-like, like DummyStruct
struct DummyStruct(i32);
impl ::std::ops::Index<usize> for DummyStruct {
type Output = i32;
fn index(&self, _: usize) -> &i32 {
&self.0
}
}
let src = DummyStruct(5);
let mut dst_vec = vec![0; 10];
for i in 0..10 {
dst_vec[i] = src[i];
}
}
#[warn(needless_range_loop)]
pub fn manual_clone(src: &[String], dst: &mut [String]) {
for i in 0..src.len() {
dst[i] = src[i].clone();
}
}