1 // Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution.
4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
7 // option. This file may not be copied, modified, or distributed
8 // except according to those terms.
10 use std::collections::*;
13 static STATIC: [usize; 4] = [0, 1, 8, 16];
14 const CONST: [usize; 4] = [0, 1, 8, 16];
17 struct Unrelated(Vec<u8>);
19 fn next(&self) -> std::slice::Iter<u8> {
23 fn iter(&self) -> std::slice::Iter<u8> {
29 clippy::needless_range_loop,
30 clippy::explicit_iter_loop,
31 clippy::explicit_into_iter_loop,
32 clippy::iter_next_loop,
33 clippy::reverse_range_loop,
36 #[warn(clippy::unused_collect)]
39 clippy::shadow_unrelated,
40 clippy::unnecessary_mut_passed,
41 clippy::cyclomatic_complexity,
44 #[allow(clippy::many_single_char_names, unused_variables, clippy::into_iter_on_array)]
46 const MAX_LEN: usize = 42;
48 let mut vec = vec![1, 2, 3, 4];
49 let vec2 = vec![1, 2, 3, 4];
50 for i in 0..vec.len() {
51 println!("{}", vec[i]);
54 for i in 0..vec.len() {
55 let i = 42; // make a different `i`
56 println!("{}", vec[i]); // ok, not the `i` of the for-loop
59 for i in 0..vec.len() {
65 println!("{:?}", STATIC[j]);
69 println!("{:?}", CONST[j]);
72 for i in 0..vec.len() {
73 println!("{} {}", vec[i], i);
75 for i in 0..vec.len() {
76 // not an error, indexing more than one variable
77 println!("{} {}", vec[i], vec2[i]);
80 for i in 0..vec.len() {
81 println!("{}", vec2[i]);
84 for i in 5..vec.len() {
85 println!("{}", vec[i]);
89 println!("{}", vec[i]);
92 for i in 0..=MAX_LEN {
93 println!("{}", vec[i]);
97 println!("{}", vec[i]);
101 println!("{}", vec[i]);
104 for i in 5..vec.len() {
105 println!("{} {}", vec[i], i);
109 println!("{} {}", vec[i], i);
120 for i in MAX_LEN..0 {
129 // not an error, this is the range with only one element “5”
134 // not an error, the start index is less than the end index
143 for i in (10..0).map(|x| x * 2) {
144 // not an error, it can't be known what arbitrary methods do to a range
148 // testing that the empty range lint folds constants
153 for i in (5 + 2)..(3 - 1) {
157 for i in (5 + 2)..(8 - 1) {
161 for i in (2 * 2)..(2 * 3) {
162 // no error, 4..6 is fine
168 // no error, not constant-foldable
174 // no error, id_col does not exist outside the loop
175 let mut id_col = vec![0f64; 10];
179 for _v in vec.iter() {}
181 for _v in vec.iter_mut() {}
183 let out_vec = vec![1, 2, 3];
184 for _v in out_vec.into_iter() {}
186 let array = [1, 2, 3];
187 for _v in array.into_iter() {}
189 for _v in &vec {} // these are fine
190 for _v in &mut vec {} // these are fine
192 for _v in [1, 2, 3].iter() {}
194 for _v in (&mut [1, 2, 3]).iter() {} // no error
196 for _v in [0; 32].iter() {}
198 for _v in [0; 33].iter() {} // no error
200 let ll: LinkedList<()> = LinkedList::new();
201 for _v in ll.iter() {}
203 let vd: VecDeque<()> = VecDeque::new();
204 for _v in vd.iter() {}
206 let bh: BinaryHeap<()> = BinaryHeap::new();
207 for _v in bh.iter() {}
209 let hm: HashMap<(), ()> = HashMap::new();
210 for _v in hm.iter() {}
212 let bt: BTreeMap<(), ()> = BTreeMap::new();
213 for _v in bt.iter() {}
215 let hs: HashSet<()> = HashSet::new();
216 for _v in hs.iter() {}
218 let bs: BTreeSet<()> = BTreeSet::new();
219 for _v in bs.iter() {}
221 for _v in vec.iter().next() {}
223 let u = Unrelated(vec![]);
224 for _v in u.next() {} // no error
225 for _v in u.iter() {} // no error
227 let mut out = vec![];
228 vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>();
229 let _y = vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>(); // this is fine
231 // Loop with explicit counter variable
233 // Potential false positives
324 let mut _x = &mut index;
334 println!("index: {}", index);
336 fn f<T>(_: &T, _: &T) -> bool {
339 fn g<T>(_: &mut [T], _: usize, _: usize) {
342 for i in 1..vec.len() {
343 if f(&vec[i - 1], &vec[i]) {
344 g(&mut vec, i - 1, i);
348 for mid in 1..vec.len() {
349 let (_, _) = vec.split_at(mid);
354 fn partition<T: PartialOrd + Send>(v: &mut [T]) -> usize {
355 let pivot = v.len() - 1;
358 if v[j] <= v[pivot] {
367 const LOOP_OFFSET: usize = 5000;
369 #[warn(clippy::needless_range_loop)]
370 pub fn manual_copy(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) {
371 // plain manual memcpy
372 for i in 0..src.len() {
377 for i in 0..src.len() {
378 dst[i + 10] = src[i];
382 for i in 0..src.len() {
383 dst[i] = src[i + 10];
387 for i in 11..src.len() {
388 dst[i] = src[i - 10];
391 // overwrite entire dst
392 for i in 0..dst.len() {
396 // manual copy with branch - can't easily convert to memcpy!
397 for i in 0..src.len() {
404 // multiple copies - suggest two memcpy statements
407 dst2[i + 500] = src[i]
410 // this is a reversal - the copy lint shouldn't be triggered
411 for i in 10..LOOP_OFFSET {
412 dst[i + LOOP_OFFSET] = src[LOOP_OFFSET - i];
416 // Offset in variable
417 for i in 10..LOOP_OFFSET {
418 dst[i + LOOP_OFFSET] = src[i - some_var];
421 // Non continuous copy - don't trigger lint
426 let src_vec = vec![1, 2, 3, 4, 5];
427 let mut dst_vec = vec![0, 0, 0, 0, 0];
429 // make sure vectors are supported
430 for i in 0..src_vec.len() {
431 dst_vec[i] = src_vec[i];
434 // lint should not trigger when either
435 // source or destination type is not
436 // slice-like, like DummyStruct
437 struct DummyStruct(i32);
439 impl ::std::ops::Index<usize> for DummyStruct {
442 fn index(&self, _: usize) -> &i32 {
447 let src = DummyStruct(5);
448 let mut dst_vec = vec![0; 10];
454 // Simplify suggestion (issue #3004)
455 let src = [0, 1, 2, 3, 4];
456 let mut dst = [0, 0, 0, 0, 0, 0];
459 for i in from..from + src.len() {
460 dst[i] = src[i - from];
463 for i in from..from + 3 {
464 dst[i] = src[i - from];
468 #[warn(clippy::needless_range_loop)]
469 pub fn manual_clone(src: &[String], dst: &mut [String]) {
470 for i in 0..src.len() {
471 dst[i] = src[i].clone();
475 #[warn(clippy::needless_range_loop)]
476 pub fn manual_copy_same_destination(dst: &mut [i32], d: usize, s: usize) {
477 // Same source and destination - don't trigger lint
478 for i in 0..dst.len() {
479 dst[d + i] = dst[s + i];
485 fn new_for_index(index: usize) -> Self;
486 fn index(&self) -> usize;
489 pub fn test<H: Handle>() -> H {
491 let next_handle = H::new_for_index(x);
492 println!("{}", next_handle.index());