diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index b27ffe73ffda..93b6e2083b54 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -56,9 +56,11 @@ declare_clippy_lint! { /// let b = &*a; /// ``` /// - /// This lint excludes: + /// This lint excludes all of: /// ```rust,ignore /// let _ = d.unwrap().deref(); + /// let _ = Foo::deref(&foo); + /// let _ = ::deref(&foo); /// ``` #[clippy::version = "1.44.0"] pub EXPLICIT_DEREF_METHODS, @@ -1480,7 +1482,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data target_mut, } => { let mut app = Applicability::MachineApplicable; - let (expr_str, expr_is_macro_call) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app); + let (expr_str, _expr_is_macro_call) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app); let ty = cx.typeck_results().expr_ty(expr); let (_, ref_count) = peel_mid_ty_refs(ty); let deref_str = if ty_changed_count >= ref_count && ref_count != 0 { @@ -1503,11 +1505,20 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data "&" }; - let expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX { - format!("({expr_str})") + // expr_str (the suggestion) is never shown if is_final_ufcs is true, since it's + // `expr.kind == ExprKind::Call`. Therefore, this is, afaik, always unnecessary. + /* + expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX { + Cow::Owned(format!("({expr_str})")) } else { - expr_str.into_owned() + expr_str }; + */ + + // Fix #10850, do not lint if it's `Foo::deref` instead of `foo.deref()`. + if is_final_ufcs { + return; + } span_lint_and_sugg( cx, diff --git a/tests/ui/explicit_deref_methods.fixed b/tests/ui/explicit_deref_methods.fixed index 60482c66da7c..1710b170fb81 100644 --- a/tests/ui/explicit_deref_methods.fixed +++ b/tests/ui/explicit_deref_methods.fixed @@ -1,11 +1,12 @@ //@run-rustfix #![warn(clippy::explicit_deref_methods)] -#![allow(unused_variables)] +#![allow(unused_variables, unused_must_use)] #![allow( clippy::borrow_deref_ref, suspicious_double_ref_op, clippy::explicit_auto_deref, clippy::needless_borrow, + clippy::no_effect, clippy::uninlined_format_args )] @@ -28,6 +29,22 @@ impl Deref for CustomVec { } } +struct Aaa; + +impl Deref for Aaa { + type Target = (); + + fn deref(&self) -> &Self::Target { + todo!(); + } +} + +impl DerefMut for Aaa { + fn deref_mut(&mut self) -> &mut Self::Target { + todo!(); + } +} + fn main() { let a: &mut String = &mut String::from("foo"); @@ -58,6 +75,17 @@ fn main() { let opt_a = Some(a.clone()); let b = &*opt_a.unwrap(); + // make sure `Aaa::deref` instead of `aaa.deref()` is not linted, as well as fully qualified + // syntax + + Aaa::deref(&Aaa); + Aaa::deref_mut(&mut Aaa); + ::deref(&Aaa); + ::deref_mut(&mut Aaa); + let mut aaa = Aaa; + Aaa::deref(&aaa); + Aaa::deref_mut(&mut aaa); + // following should not require linting let cv = CustomVec(vec![0, 42]); diff --git a/tests/ui/explicit_deref_methods.rs b/tests/ui/explicit_deref_methods.rs index e3613e216bb2..85147e1cb697 100644 --- a/tests/ui/explicit_deref_methods.rs +++ b/tests/ui/explicit_deref_methods.rs @@ -1,11 +1,12 @@ //@run-rustfix #![warn(clippy::explicit_deref_methods)] -#![allow(unused_variables)] +#![allow(unused_variables, unused_must_use)] #![allow( clippy::borrow_deref_ref, suspicious_double_ref_op, clippy::explicit_auto_deref, clippy::needless_borrow, + clippy::no_effect, clippy::uninlined_format_args )] @@ -28,6 +29,22 @@ impl Deref for CustomVec { } } +struct Aaa; + +impl Deref for Aaa { + type Target = (); + + fn deref(&self) -> &Self::Target { + todo!(); + } +} + +impl DerefMut for Aaa { + fn deref_mut(&mut self) -> &mut Self::Target { + todo!(); + } +} + fn main() { let a: &mut String = &mut String::from("foo"); @@ -58,6 +75,17 @@ fn main() { let opt_a = Some(a.clone()); let b = opt_a.unwrap().deref(); + // make sure `Aaa::deref` instead of `aaa.deref()` is not linted, as well as fully qualified + // syntax + + Aaa::deref(&Aaa); + Aaa::deref_mut(&mut Aaa); + ::deref(&Aaa); + ::deref_mut(&mut Aaa); + let mut aaa = Aaa; + Aaa::deref(&aaa); + Aaa::deref_mut(&mut aaa); + // following should not require linting let cv = CustomVec(vec![0, 42]); diff --git a/tests/ui/explicit_deref_methods.stderr b/tests/ui/explicit_deref_methods.stderr index 4b10ed1377b0..592563ffa8c8 100644 --- a/tests/ui/explicit_deref_methods.stderr +++ b/tests/ui/explicit_deref_methods.stderr @@ -1,5 +1,5 @@ error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:36:19 + --> $DIR/explicit_deref_methods.rs:53:19 | LL | let b: &str = a.deref(); | ^^^^^^^^^ help: try this: `&*a` @@ -7,67 +7,67 @@ LL | let b: &str = a.deref(); = note: `-D clippy::explicit-deref-methods` implied by `-D warnings` error: explicit `deref_mut` method call - --> $DIR/explicit_deref_methods.rs:38:23 + --> $DIR/explicit_deref_methods.rs:55:23 | LL | let b: &mut str = a.deref_mut(); | ^^^^^^^^^^^^^ help: try this: `&mut **a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:41:39 + --> $DIR/explicit_deref_methods.rs:58:39 | LL | let b: String = format!("{}, {}", a.deref(), a.deref()); | ^^^^^^^^^ help: try this: `&*a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:41:50 + --> $DIR/explicit_deref_methods.rs:58:50 | LL | let b: String = format!("{}, {}", a.deref(), a.deref()); | ^^^^^^^^^ help: try this: `&*a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:43:20 + --> $DIR/explicit_deref_methods.rs:60:20 | LL | println!("{}", a.deref()); | ^^^^^^^^^ help: try this: `&*a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:46:11 + --> $DIR/explicit_deref_methods.rs:63:11 | LL | match a.deref() { | ^^^^^^^^^ help: try this: `&*a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:50:28 + --> $DIR/explicit_deref_methods.rs:67:28 | LL | let b: String = concat(a.deref()); | ^^^^^^^^^ help: try this: `&*a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:52:13 + --> $DIR/explicit_deref_methods.rs:69:13 | LL | let b = just_return(a).deref(); | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `just_return(a)` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:54:28 + --> $DIR/explicit_deref_methods.rs:71:28 | LL | let b: String = concat(just_return(a).deref()); | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `just_return(a)` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:56:19 + --> $DIR/explicit_deref_methods.rs:73:19 | LL | let b: &str = a.deref().deref(); | ^^^^^^^^^^^^^^^^^ help: try this: `&**a` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:59:13 + --> $DIR/explicit_deref_methods.rs:76:13 | LL | let b = opt_a.unwrap().deref(); | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&*opt_a.unwrap()` error: explicit `deref` method call - --> $DIR/explicit_deref_methods.rs:85:31 + --> $DIR/explicit_deref_methods.rs:113:31 | LL | let b: &str = expr_deref!(a.deref()); | ^^^^^^^^^ help: try this: `&*a`