mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

needless_pass_by_value: Whitelist RangeArgument (fixes #2357)

Browse Source
This commit is contained in:
Manish Goregaokar 2018-01-18 14:19:19 +05:30
parent 2a30c8a194
commit 552e950080
4 changed files with 61 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
clippy_lints/src/needless_pass_by_value.rs
View File

@ -102,10 +102,11 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue {
// Allow `Borrow` or functions to be taken by value
let borrow_trait = need!(get_trait_def_id(cx, &paths::BORROW_TRAIT));
let fn_traits = [
let whitelisted_traits = [
need!(cx.tcx.lang_items().fn_trait()),
need!(cx.tcx.lang_items().fn_once_trait()),
need!(cx.tcx.lang_items().fn_mut_trait()),
need!(get_trait_def_id(cx, &paths::RANGE_ARGUMENT_TRAIT))
];
let sized_trait = need!(cx.tcx.lang_items().sized_trait());
@ -189,7 +190,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue {
if !is_self(arg);
if !ty.is_mutable_pointer();
if !is_copy(cx, ty);
if !fn_traits.iter().any(|&t| implements_trait(cx, ty, t, &[]));
if !whitelisted_traits.iter().any(|&t| implements_trait(cx, ty, t, &[]));
if !implements_borrow_trait;
if !all_borrowable_trait;

1
clippy_lints/src/utils/paths.rs
View File

@ -55,6 +55,7 @@ pub const OPTION_SOME: [&str; 4] = ["core", "option", "Option", "Some"];
pub const PTR_NULL: [&str; 2] = ["ptr", "null"];
pub const PTR_NULL_MUT: [&str; 2] = ["ptr", "null_mut"];
pub const RANGE: [&str; 3] = ["core", "ops", "Range"];
pub const RANGE_ARGUMENT_TRAIT: [&str; 3] = ["alloc", "range", "RangeArgument"];
pub const RANGE_FROM: [&str; 3] = ["core", "ops", "RangeFrom"];
pub const RANGE_FROM_STD: [&str; 3] = ["std", "ops", "RangeFrom"];
pub const RANGE_FULL: [&str; 3] = ["core", "ops", "RangeFull"];

7
tests/ui/needless_pass_by_value.rs
View File

@ -4,6 +4,8 @@
#![warn(needless_pass_by_value)]
#![allow(dead_code, single_match, if_let_redundant_pattern_matching, many_single_char_names)]
#![feature(collections_range)]
use std::borrow::Borrow;
use std::convert::AsRef;
@ -113,4 +115,9 @@ trait FalsePositive {
// shouldn't warn on extern funcs
extern "C" fn ext(x: String) -> usize { x.len() }
// whitelist RangeArgument
fn range<T: ::std::collections::range::RangeArgument<usize>>(range: T) {
let _ = range.start();
}
fn main() {}

100
tests/ui/needless_pass_by_value.stderr
View File

@ -1,151 +1,151 @@
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:12:23
--> $DIR/needless_pass_by_value.rs:14:23
|
12 | fn foo<T: Default>(v: Vec<T>, w: Vec<T>, mut x: Vec<T>, y: Vec<T>) -> Vec<T> {
14 | fn foo<T: Default>(v: Vec<T>, w: Vec<T>, mut x: Vec<T>, y: Vec<T>) -> Vec<T> {
| ^^^^^^ help: consider changing the type to: `&[T]`
|
= note: `-D needless-pass-by-value` implied by `-D warnings`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:26:11
--> $DIR/needless_pass_by_value.rs:28:11
|
26 | fn bar(x: String, y: Wrapper) {
28 | fn bar(x: String, y: Wrapper) {
| ^^^^^^ help: consider changing the type to: `&str`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:26:22
--> $DIR/needless_pass_by_value.rs:28:22
|
26 | fn bar(x: String, y: Wrapper) {
28 | fn bar(x: String, y: Wrapper) {
| ^^^^^^^ help: consider taking a reference instead: `&Wrapper`
|
help: consider marking this type as Copy if possible
--> $DIR/needless_pass_by_value.rs:24:1
--> $DIR/needless_pass_by_value.rs:26:1
|
24 | struct Wrapper(String);
26 | struct Wrapper(String);
| ^^^^^^^^^^^^^^^^^^^^^^^
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:32:71
--> $DIR/needless_pass_by_value.rs:34:71
|
32 | fn test_borrow_trait<T: Borrow<str>, U: AsRef<str>, V>(t: T, u: U, v: V) {
34 | fn test_borrow_trait<T: Borrow<str>, U: AsRef<str>, V>(t: T, u: U, v: V) {
| ^ help: consider taking a reference instead: `&V`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:44:18
--> $DIR/needless_pass_by_value.rs:46:18
|
44 | fn test_match(x: Option<Option<String>>, y: Option<Option<String>>) {
46 | fn test_match(x: Option<Option<String>>, y: Option<Option<String>>) {
| ^^^^^^^^^^^^^^^^^^^^^^
help: consider taking a reference instead
|
44 | fn test_match(x: &Option<Option<String>>, y: Option<Option<String>>) {
45 | match *x {
46 | fn test_match(x: &Option<Option<String>>, y: Option<Option<String>>) {
47 | match *x {
|
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:57:24
--> $DIR/needless_pass_by_value.rs:59:24
|
57 | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) {
59 | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) {
| ^^^^^^^ help: consider taking a reference instead: `&Wrapper`
|
help: consider marking this type as Copy if possible
--> $DIR/needless_pass_by_value.rs:24:1
--> $DIR/needless_pass_by_value.rs:26:1
|
24 | struct Wrapper(String);
26 | struct Wrapper(String);
| ^^^^^^^^^^^^^^^^^^^^^^^
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:57:36
--> $DIR/needless_pass_by_value.rs:59:36
|
57 | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) {
59 | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) {
| ^^^^^^^
|
help: consider marking this type as Copy if possible
--> $DIR/needless_pass_by_value.rs:24:1
--> $DIR/needless_pass_by_value.rs:26:1
|
24 | struct Wrapper(String);
26 | struct Wrapper(String);
| ^^^^^^^^^^^^^^^^^^^^^^^
help: consider taking a reference instead
|
57 | fn test_destructure(x: Wrapper, y: &Wrapper, z: Wrapper) {
58 | let Wrapper(s) = z; // moved
59 | let Wrapper(ref t) = *y; // not moved
60 | let Wrapper(_) = *y; // still not moved
59 | fn test_destructure(x: Wrapper, y: &Wrapper, z: Wrapper) {
60 | let Wrapper(s) = z; // moved
61 | let Wrapper(ref t) = *y; // not moved
62 | let Wrapper(_) = *y; // still not moved
|
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:73:49
--> $DIR/needless_pass_by_value.rs:75:49
|
73 | fn test_blanket_ref<T: Foo, S: Serialize>(_foo: T, _serializable: S) {}
75 | fn test_blanket_ref<T: Foo, S: Serialize>(_foo: T, _serializable: S) {}
| ^ help: consider taking a reference instead: `&T`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:75:18
--> $DIR/needless_pass_by_value.rs:77:18
|
75 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
77 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
| ^^^^^^ help: consider taking a reference instead: `&String`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:75:29
--> $DIR/needless_pass_by_value.rs:77:29
|
75 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
77 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
| ^^^^^^
help: consider changing the type to
|
75 | fn issue_2114(s: String, t: &str, u: Vec<i32>, v: Vec<i32>) {
77 | fn issue_2114(s: String, t: &str, u: Vec<i32>, v: Vec<i32>) {
| ^^^^
help: change `t.clone()` to
|
77 | let _ = t.to_string();
79 | let _ = t.to_string();
| ^^^^^^^^^^^^^
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:75:40
--> $DIR/needless_pass_by_value.rs:77:40
|
75 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
77 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
| ^^^^^^^^ help: consider taking a reference instead: `&Vec<i32>`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:75:53
--> $DIR/needless_pass_by_value.rs:77:53
|
75 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
77 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
| ^^^^^^^^
help: consider changing the type to
|
75 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: &[i32]) {
77 | fn issue_2114(s: String, t: String, u: Vec<i32>, v: &[i32]) {
| ^^^^^^
help: change `v.clone()` to
|
79 | let _ = v.to_owned();
81 | let _ = v.to_owned();
| ^^^^^^^^^^^^
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:87:12
--> $DIR/needless_pass_by_value.rs:89:12
|
87 | s: String,
89 | s: String,
| ^^^^^^ help: consider changing the type to: `&str`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:88:12
--> $DIR/needless_pass_by_value.rs:90:12
|
88 | t: String,
90 | t: String,
| ^^^^^^ help: consider taking a reference instead: `&String`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:100:13
--> $DIR/needless_pass_by_value.rs:102:13
|
100 | _u: U,
102 | _u: U,
| ^ help: consider taking a reference instead: `&U`
error: this argument is passed by value, but not consumed in the function body
--> $DIR/needless_pass_by_value.rs:101:13
--> $DIR/needless_pass_by_value.rs:103:13
|
101 | _s: Self,
103 | _s: Self,
| ^^^^ help: consider taking a reference instead: `&Self`
|
help: consider marking this type as Copy if possible
--> $DIR/needless_pass_by_value.rs:82:1
--> $DIR/needless_pass_by_value.rs:84:1
|
82 | struct S<T, U>(T, U);
84 | struct S<T, U>(T, U);
| ^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 16 previous errors