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map_clone: avoid suggesting copied() for &mut

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This commit is contained in:
Eduardo Broto 2020-04-25 22:49:06 +02:00
parent 6ffe725bbc
commit 806d973adc
4 changed files with 31 additions and 8 deletions
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5
clippy_lints/src/map_clone.rs
View file

@ -7,6 +7,7 @@ use rustc_ast::ast::Ident;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::mir::Mutability;
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
@ -58,7 +59,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
let closure_expr = remove_blocks(&closure_body.value);
then {
match closure_body.params[0].pat.kind {
hir::PatKind::Ref(ref inner, _) => if let hir::PatKind::Binding(
hir::PatKind::Ref(ref inner, hir::Mutability::Not) => if let hir::PatKind::Binding(
hir::BindingAnnotation::Unannotated, .., name, None
) = inner.kind {
if ident_eq(name, closure_expr) {
@ -69,7 +70,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
match closure_expr.kind {
hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner) => {
if ident_eq(name, inner) {
if let ty::Ref(..) = cx.tables.expr_ty(inner).kind {
if let ty::Ref(.., Mutability::Not) = cx.tables.expr_ty(inner).kind {
lint(cx, e.span, args[0].span, true);
}
}

11
tests/ui/map_clone.fixed
View file

@ -4,6 +4,7 @@
#![allow(clippy::clone_on_copy, clippy::redundant_clone)]
#![allow(clippy::missing_docs_in_private_items)]
#![allow(clippy::redundant_closure_for_method_calls)]
#![allow(clippy::many_single_char_names)]
fn main() {
let _: Vec<i8> = vec![5_i8; 6].iter().copied().collect();
@ -33,4 +34,14 @@ fn main() {
let v: Vec<Rc<u32>> = vec![Rc::new(0_u32)];
let _: Vec<u32> = v.into_iter().map(|x| *x).collect();
}
// Issue #5524 mutable references
{
let mut c = 42;
let v = vec![&mut c];
let _: Vec<u32> = v.into_iter().map(|x| *x).collect();
let mut d = 21;
let v = vec![&mut d];
let _: Vec<u32> = v.into_iter().map(|&mut x| x).collect();
}
}

11
tests/ui/map_clone.rs
View file

@ -4,6 +4,7 @@
#![allow(clippy::clone_on_copy, clippy::redundant_clone)]
#![allow(clippy::missing_docs_in_private_items)]
#![allow(clippy::redundant_closure_for_method_calls)]
#![allow(clippy::many_single_char_names)]
fn main() {
let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();
@ -33,4 +34,14 @@ fn main() {
let v: Vec<Rc<u32>> = vec![Rc::new(0_u32)];
let _: Vec<u32> = v.into_iter().map(|x| *x).collect();
}
// Issue #5524 mutable references
{
let mut c = 42;
let v = vec![&mut c];
let _: Vec<u32> = v.into_iter().map(|x| *x).collect();
let mut d = 21;
let v = vec![&mut d];
let _: Vec<u32> = v.into_iter().map(|&mut x| x).collect();
}
}

12
tests/ui/map_clone.stderr
View file

@ -1,5 +1,5 @@
error: You are using an explicit closure for copying elements
--> $DIR/map_clone.rs:9:22
--> $DIR/map_clone.rs:10:22
|
LL | let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![5_i8; 6].iter().copied()`
@ -7,31 +7,31 @@ LL | let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();
= note: `-D clippy::map-clone` implied by `-D warnings`
error: You are using an explicit closure for cloning elements
--> $DIR/map_clone.rs:10:26
--> $DIR/map_clone.rs:11:26
|
LL | let _: Vec<String> = vec![String::new()].iter().map(|x| x.clone()).collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![String::new()].iter().cloned()`
error: You are using an explicit closure for copying elements
--> $DIR/map_clone.rs:11:23
--> $DIR/map_clone.rs:12:23
|
LL | let _: Vec<u32> = vec![42, 43].iter().map(|&x| x).collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![42, 43].iter().copied()`
error: You are using an explicit closure for copying elements
--> $DIR/map_clone.rs:13:26
--> $DIR/map_clone.rs:14:26
|
LL | let _: Option<u64> = Some(&16).map(|b| *b);
| ^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `Some(&16).copied()`
error: You are using an explicit closure for copying elements
--> $DIR/map_clone.rs:14:25
--> $DIR/map_clone.rs:15:25
|
LL | let _: Option<u8> = Some(&1).map(|x| x.clone());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `Some(&1).copied()`
error: You are needlessly cloning iterator elements
--> $DIR/map_clone.rs:25:29
--> $DIR/map_clone.rs:26:29
|
LL | let _ = std::env::args().map(|v| v.clone());
| ^^^^^^^^^^^^^^^^^^^ help: Remove the `map` call