diff --git a/clippy_lints/src/needless_pass_by_ref_mut.rs b/clippy_lints/src/needless_pass_by_ref_mut.rs
index 30d3e86dc4e..9e47c3ad0b7 100644
--- a/clippy_lints/src/needless_pass_by_ref_mut.rs
+++ b/clippy_lints/src/needless_pass_by_ref_mut.rs
@@ -83,7 +83,9 @@ fn should_skip<'tcx>(
}
if is_self(arg) {
- return true;
+ // Interestingly enough, `self` arguments make `is_from_proc_macro` return `true`, hence why
+ // we return early here.
+ return false;
}
if let PatKind::Binding(.., name, _) = arg.pat.kind {
@@ -185,7 +187,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByRefMut<'tcx> {
}
// Collect variables mutably used and spans which will need dereferencings from the
// function body.
- let MutablyUsedVariablesCtxt { mutably_used_vars, .. } = {
+ let mutably_used_vars = {
let mut ctx = MutablyUsedVariablesCtxt {
mutably_used_vars: HirIdSet::default(),
prev_bind: None,
@@ -217,7 +219,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByRefMut<'tcx> {
check_closures(&mut ctx, cx, &infcx, &mut checked_closures, async_closures);
}
}
- ctx
+ ctx.generate_mutably_used_ids_from_aliases()
};
for ((&input, &_), arg) in it {
// Only take `&mut` arguments.
@@ -309,14 +311,24 @@ struct MutablyUsedVariablesCtxt<'tcx> {
}
impl<'tcx> MutablyUsedVariablesCtxt<'tcx> {
- fn add_mutably_used_var(&mut self, mut used_id: HirId) {
- while let Some(id) = self.aliases.get(&used_id) {
- self.mutably_used_vars.insert(used_id);
- used_id = *id;
- }
+ fn add_mutably_used_var(&mut self, used_id: HirId) {
self.mutably_used_vars.insert(used_id);
}
+ // Because the alias may come after the mutable use of a variable, we need to fill the map at
+ // the end.
+ fn generate_mutably_used_ids_from_aliases(mut self) -> HirIdSet {
+ let all_ids = self.mutably_used_vars.iter().copied().collect::<Vec<_>>();
+ for mut used_id in all_ids {
+ while let Some(id) = self.aliases.get(&used_id) {
+ self.mutably_used_vars.insert(used_id);
+ used_id = *id;
+ }
+ self.mutably_used_vars.insert(used_id);
+ }
+ self.mutably_used_vars
+ }
+
fn would_be_alias_cycle(&self, alias: HirId, mut target: HirId) -> bool {
while let Some(id) = self.aliases.get(&target) {
if *id == alias {
diff --git a/tests/ui/needless_pass_by_ref_mut.rs b/tests/ui/needless_pass_by_ref_mut.rs
index a92197fb0af..3f5f55f4002 100644
--- a/tests/ui/needless_pass_by_ref_mut.rs
+++ b/tests/ui/needless_pass_by_ref_mut.rs
@@ -44,18 +44,13 @@ fn non_mut_ref(_: &Vec<u32>) {}
struct Bar;
impl Bar {
- // Should not warn on `&mut self`.
fn bar(&mut self) {}
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
fn mushroom(&self, vec: &mut Vec<i32>) -> usize {
//~^ ERROR: this argument is a mutable reference, but not used mutably
vec.len()
}
-
- fn badger(&mut self, vec: &mut Vec<i32>) -> usize {
- //~^ ERROR: this argument is a mutable reference, but not used mutably
- vec.len()
- }
}
trait Babar {
@@ -307,6 +302,41 @@ fn filter_copy<T: Copy>(predicate: &mut impl FnMut(T) -> bool) -> impl FnMut(&T)
move |&item| predicate(item)
}
+trait MutSelfTrait {
+ // Should not warn since it's a trait method.
+ fn mut_self(&mut self);
+}
+
+struct MutSelf {
+ a: u32,
+}
+
+impl MutSelf {
+ fn bar(&mut self) {}
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async fn foo(&mut self, u: &mut i32, v: &mut u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ //~| ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ *u += 1;
+ }
+ .await;
+ }
+ async fn foo2(&mut self, u: &mut i32, v: &mut u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ self.a += 1;
+ *u += 1;
+ }
+ .await;
+ }
+}
+
+impl MutSelfTrait for MutSelf {
+ // Should not warn since it's a trait method.
+ fn mut_self(&mut self) {}
+}
+
// `is_from_proc_macro` stress tests
fn _empty_tup(x: &mut (())) {}
fn _single_tup(x: &mut ((i32,))) {}
diff --git a/tests/ui/needless_pass_by_ref_mut.stderr b/tests/ui/needless_pass_by_ref_mut.stderr
index 89dad3e60b1..21ca393dcb6 100644
--- a/tests/ui/needless_pass_by_ref_mut.stderr
+++ b/tests/ui/needless_pass_by_ref_mut.stderr
@@ -13,6 +13,12 @@ error: this argument is a mutable reference, but not used mutably
LL | fn foo6(s: &mut Vec<u32>) {
| ^^^^^^^^^^^^^ help: consider changing to: `&Vec<u32>`
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut.rs:47:12
+ |
+LL | fn bar(&mut self) {}
+ | ^^^^^^^^^ help: consider changing to: `&self`
+
error: this argument is a mutable reference, but not used mutably
--> tests/ui/needless_pass_by_ref_mut.rs:50:29
|
@@ -20,67 +26,61 @@ LL | fn mushroom(&self, vec: &mut Vec<i32>) -> usize {
| ^^^^^^^^^^^^^ help: consider changing to: `&Vec<i32>`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:55:31
- |
-LL | fn badger(&mut self, vec: &mut Vec<i32>) -> usize {
- | ^^^^^^^^^^^^^ help: consider changing to: `&Vec<i32>`
-
-error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:132:16
+ --> tests/ui/needless_pass_by_ref_mut.rs:127:16
|
LL | async fn a1(x: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:136:16
+ --> tests/ui/needless_pass_by_ref_mut.rs:131:16
|
LL | async fn a2(x: &mut i32, y: String) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:140:16
+ --> tests/ui/needless_pass_by_ref_mut.rs:135:16
|
LL | async fn a3(x: &mut i32, y: String, z: String) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:144:16
+ --> tests/ui/needless_pass_by_ref_mut.rs:139:16
|
LL | async fn a4(x: &mut i32, y: i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:148:24
+ --> tests/ui/needless_pass_by_ref_mut.rs:143:24
|
LL | async fn a5(x: i32, y: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:152:24
+ --> tests/ui/needless_pass_by_ref_mut.rs:147:24
|
LL | async fn a6(x: i32, y: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:156:32
+ --> tests/ui/needless_pass_by_ref_mut.rs:151:32
|
LL | async fn a7(x: i32, y: i32, z: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:160:24
+ --> tests/ui/needless_pass_by_ref_mut.rs:155:24
|
LL | async fn a8(x: i32, a: &mut i32, y: i32, z: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:160:45
+ --> tests/ui/needless_pass_by_ref_mut.rs:155:45
|
LL | async fn a8(x: i32, a: &mut i32, y: i32, z: &mut i32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:194:16
+ --> tests/ui/needless_pass_by_ref_mut.rs:189:16
|
LL | fn cfg_warn(s: &mut u32) {}
| ^^^^^^^^ help: consider changing to: `&u32`
@@ -88,7 +88,7 @@ LL | fn cfg_warn(s: &mut u32) {}
= note: this is cfg-gated and may require further changes
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:200:20
+ --> tests/ui/needless_pass_by_ref_mut.rs:195:20
|
LL | fn cfg_warn(s: &mut u32) {}
| ^^^^^^^^ help: consider changing to: `&u32`
@@ -96,19 +96,19 @@ LL | fn cfg_warn(s: &mut u32) {}
= note: this is cfg-gated and may require further changes
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:214:39
+ --> tests/ui/needless_pass_by_ref_mut.rs:209:39
|
LL | async fn inner_async2(x: &mut i32, y: &mut u32) {
| ^^^^^^^^ help: consider changing to: `&u32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:222:26
+ --> tests/ui/needless_pass_by_ref_mut.rs:217:26
|
LL | async fn inner_async3(x: &mut i32, y: &mut u32) {
| ^^^^^^^^ help: consider changing to: `&i32`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:241:34
+ --> tests/ui/needless_pass_by_ref_mut.rs:236:34
|
LL | pub async fn call_in_closure1(n: &mut str) {
| ^^^^^^^^ help: consider changing to: `&str`
@@ -116,15 +116,7 @@ LL | pub async fn call_in_closure1(n: &mut str) {
= warning: changing this function will impact semver compatibility
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:253:25
- |
-LL | pub async fn closure(n: &mut usize) -> impl '_ + FnMut() {
- | ^^^^^^^^^^ help: consider changing to: `&usize`
- |
- = warning: changing this function will impact semver compatibility
-
-error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:260:20
+ --> tests/ui/needless_pass_by_ref_mut.rs:255:20
|
LL | pub fn closure2(n: &mut usize) -> impl '_ + FnMut() -> usize {
| ^^^^^^^^^^ help: consider changing to: `&usize`
@@ -132,7 +124,7 @@ LL | pub fn closure2(n: &mut usize) -> impl '_ + FnMut() -> usize {
= warning: changing this function will impact semver compatibility
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:271:26
+ --> tests/ui/needless_pass_by_ref_mut.rs:266:26
|
LL | pub async fn closure4(n: &mut usize) {
| ^^^^^^^^^^ help: consider changing to: `&usize`
@@ -140,64 +132,88 @@ LL | pub async fn closure4(n: &mut usize) {
= warning: changing this function will impact semver compatibility
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:311:18
+ --> tests/ui/needless_pass_by_ref_mut.rs:315:12
+ |
+LL | fn bar(&mut self) {}
+ | ^^^^^^^^^ help: consider changing to: `&self`
+
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut.rs:317:18
+ |
+LL | async fn foo(&mut self, u: &mut i32, v: &mut u32) {
+ | ^^^^^^^^^ help: consider changing to: `&self`
+
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut.rs:317:45
+ |
+LL | async fn foo(&mut self, u: &mut i32, v: &mut u32) {
+ | ^^^^^^^^ help: consider changing to: `&u32`
+
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut.rs:325:46
+ |
+LL | async fn foo2(&mut self, u: &mut i32, v: &mut u32) {
+ | ^^^^^^^^ help: consider changing to: `&u32`
+
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut.rs:341:18
|
LL | fn _empty_tup(x: &mut (())) {}
| ^^^^^^^^^ help: consider changing to: `&()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:312:19
+ --> tests/ui/needless_pass_by_ref_mut.rs:342:19
|
LL | fn _single_tup(x: &mut ((i32,))) {}
| ^^^^^^^^^^^^^ help: consider changing to: `&(i32,)`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:313:18
+ --> tests/ui/needless_pass_by_ref_mut.rs:343:18
|
LL | fn _multi_tup(x: &mut ((i32, u32))) {}
| ^^^^^^^^^^^^^^^^^ help: consider changing to: `&(i32, u32)`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:314:11
+ --> tests/ui/needless_pass_by_ref_mut.rs:344:11
|
LL | fn _fn(x: &mut (fn())) {}
| ^^^^^^^^^^^ help: consider changing to: `&fn()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:316:23
+ --> tests/ui/needless_pass_by_ref_mut.rs:346:23
|
LL | fn _extern_rust_fn(x: &mut extern "Rust" fn()) {}
| ^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&extern "Rust" fn()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:317:20
+ --> tests/ui/needless_pass_by_ref_mut.rs:347:20
|
LL | fn _extern_c_fn(x: &mut extern "C" fn()) {}
| ^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&extern "C" fn()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:318:18
+ --> tests/ui/needless_pass_by_ref_mut.rs:348:18
|
LL | fn _unsafe_fn(x: &mut unsafe fn()) {}
| ^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe fn()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:319:25
+ --> tests/ui/needless_pass_by_ref_mut.rs:349:25
|
LL | fn _unsafe_extern_fn(x: &mut unsafe extern "C" fn()) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn()`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:320:20
+ --> tests/ui/needless_pass_by_ref_mut.rs:350:20
|
LL | fn _fn_with_arg(x: &mut unsafe extern "C" fn(i32)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn(i32)`
error: this argument is a mutable reference, but not used mutably
- --> tests/ui/needless_pass_by_ref_mut.rs:321:20
+ --> tests/ui/needless_pass_by_ref_mut.rs:351:20
|
LL | fn _fn_with_ret(x: &mut unsafe extern "C" fn() -> (i32)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn() -> (i32)`
-error: aborting due to 31 previous errors
+error: aborting due to 34 previous errors
diff --git a/tests/ui/needless_pass_by_ref_mut2.fixed b/tests/ui/needless_pass_by_ref_mut2.fixed
new file mode 100644
index 00000000000..3c2576213cd
--- /dev/null
+++ b/tests/ui/needless_pass_by_ref_mut2.fixed
@@ -0,0 +1,24 @@
+// If both `inner_async3` and `inner_async4` are present, aliases are declared after
+// they're used in `inner_async4` for some reasons... This test ensures that no
+// only `v` is marked as not used mutably in `inner_async4`.
+
+#![allow(clippy::redundant_closure_call)]
+#![warn(clippy::needless_pass_by_ref_mut)]
+
+pub async fn inner_async3(x: &i32, y: &mut u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ *y += 1;
+ }
+ .await;
+}
+
+pub async fn inner_async4(u: &mut i32, v: &u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ *u += 1;
+ }
+ .await;
+}
+
+fn main() {}
diff --git a/tests/ui/needless_pass_by_ref_mut2.rs b/tests/ui/needless_pass_by_ref_mut2.rs
new file mode 100644
index 00000000000..34b0b564deb
--- /dev/null
+++ b/tests/ui/needless_pass_by_ref_mut2.rs
@@ -0,0 +1,24 @@
+// If both `inner_async3` and `inner_async4` are present, aliases are declared after
+// they're used in `inner_async4` for some reasons... This test ensures that no
+// only `v` is marked as not used mutably in `inner_async4`.
+
+#![allow(clippy::redundant_closure_call)]
+#![warn(clippy::needless_pass_by_ref_mut)]
+
+pub async fn inner_async3(x: &mut i32, y: &mut u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ *y += 1;
+ }
+ .await;
+}
+
+pub async fn inner_async4(u: &mut i32, v: &mut u32) {
+ //~^ ERROR: this argument is a mutable reference, but not used mutably
+ async {
+ *u += 1;
+ }
+ .await;
+}
+
+fn main() {}
diff --git a/tests/ui/needless_pass_by_ref_mut2.stderr b/tests/ui/needless_pass_by_ref_mut2.stderr
new file mode 100644
index 00000000000..c8753603225
--- /dev/null
+++ b/tests/ui/needless_pass_by_ref_mut2.stderr
@@ -0,0 +1,20 @@
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut2.rs:8:30
+ |
+LL | pub async fn inner_async3(x: &mut i32, y: &mut u32) {
+ | ^^^^^^^^ help: consider changing to: `&i32`
+ |
+ = warning: changing this function will impact semver compatibility
+ = note: `-D clippy::needless-pass-by-ref-mut` implied by `-D warnings`
+ = help: to override `-D warnings` add `#[allow(clippy::needless_pass_by_ref_mut)]`
+
+error: this argument is a mutable reference, but not used mutably
+ --> tests/ui/needless_pass_by_ref_mut2.rs:16:43
+ |
+LL | pub async fn inner_async4(u: &mut i32, v: &mut u32) {
+ | ^^^^^^^^ help: consider changing to: `&u32`
+ |
+ = warning: changing this function will impact semver compatibility
+
+error: aborting due to 2 previous errors
+