diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index 5edb5c235703..a2cedba98327 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -997,6 +997,15 @@ fn report<'tcx>( ); }, State::DerefedBorrow(state) => { + // Do not suggest removing a non-mandatory `&` in `&*rawptr` in an `unsafe` context, + // as this may make rustc trigger its `dangerous_implicit_autorefs` lint. + if let ExprKind::AddrOf(BorrowKind::Ref, _, subexpr) = data.first_expr.kind + && let ExprKind::Unary(UnOp::Deref, subsubexpr) = subexpr.kind + && cx.typeck_results().expr_ty_adjusted(subsubexpr).is_raw_ptr() + { + return; + } + let mut app = Applicability::MachineApplicable; let (snip, snip_is_macro) = snippet_with_context(cx, expr.span, data.first_expr.span.ctxt(), "..", &mut app); diff --git a/tests/ui/needless_borrow.fixed b/tests/ui/needless_borrow.fixed index d7d344452c5d..54cad2e393fd 100644 --- a/tests/ui/needless_borrow.fixed +++ b/tests/ui/needless_borrow.fixed @@ -107,9 +107,6 @@ fn main() { let x = (1, 2); let _ = x.0; //~^ needless_borrow - let x = &x as *const (i32, i32); - let _ = unsafe { (*x).0 }; - //~^ needless_borrow // Issue #8367 trait Foo { @@ -289,3 +286,15 @@ fn issue_12268() { // compiler } + +fn issue_14743(slice: &[T]) { + let _ = slice.len(); + //~^ needless_borrow + + let slice = slice as *const [T]; + let _ = unsafe { (&*slice).len() }; + + // Check that rustc would actually warn if Clippy had suggested removing the reference + #[expect(dangerous_implicit_autorefs)] + let _ = unsafe { (*slice).len() }; +} diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs index 1f05b90b4728..b698c6bfc969 100644 --- a/tests/ui/needless_borrow.rs +++ b/tests/ui/needless_borrow.rs @@ -107,9 +107,6 @@ fn main() { let x = (1, 2); let _ = (&x).0; //~^ needless_borrow - let x = &x as *const (i32, i32); - let _ = unsafe { (&*x).0 }; - //~^ needless_borrow // Issue #8367 trait Foo { @@ -289,3 +286,15 @@ fn issue_12268() { // compiler } + +fn issue_14743(slice: &[T]) { + let _ = (&slice).len(); + //~^ needless_borrow + + let slice = slice as *const [T]; + let _ = unsafe { (&*slice).len() }; + + // Check that rustc would actually warn if Clippy had suggested removing the reference + #[expect(dangerous_implicit_autorefs)] + let _ = unsafe { (*slice).len() }; +} diff --git a/tests/ui/needless_borrow.stderr b/tests/ui/needless_borrow.stderr index b036b1e47d18..172d36bd73a0 100644 --- a/tests/ui/needless_borrow.stderr +++ b/tests/ui/needless_borrow.stderr @@ -103,71 +103,71 @@ error: this expression borrows a value the compiler would automatically borrow LL | let _ = (&x).0; | ^^^^ help: change this to: `x` -error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:111:22 - | -LL | let _ = unsafe { (&*x).0 }; - | ^^^^^ help: change this to: `(*x)` - error: this expression creates a reference which is immediately dereferenced by the compiler - --> tests/ui/needless_borrow.rs:122:5 + --> tests/ui/needless_borrow.rs:119:5 | LL | (&&()).foo(); | ^^^^^^ help: change this to: `(&())` error: this expression creates a reference which is immediately dereferenced by the compiler - --> tests/ui/needless_borrow.rs:132:5 + --> tests/ui/needless_borrow.rs:129:5 | LL | (&&5).foo(); | ^^^^^ help: change this to: `(&5)` error: this expression creates a reference which is immediately dereferenced by the compiler - --> tests/ui/needless_borrow.rs:159:23 + --> tests/ui/needless_borrow.rs:156:23 | LL | let x: (&str,) = (&"",); | ^^^ help: change this to: `""` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:202:13 + --> tests/ui/needless_borrow.rs:199:13 | LL | (&self.f)() | ^^^^^^^^^ help: change this to: `(self.f)` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:212:13 + --> tests/ui/needless_borrow.rs:209:13 | LL | (&mut self.f)() | ^^^^^^^^^^^^^ help: change this to: `(self.f)` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:250:22 + --> tests/ui/needless_borrow.rs:247:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:258:22 + --> tests/ui/needless_borrow.rs:255:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:263:22 + --> tests/ui/needless_borrow.rs:260:22 | LL | let _ = &mut (&mut x.u).x; | ^^^^^^^^^^ help: change this to: `x.u` error: this expression borrows a value the compiler would automatically borrow - --> tests/ui/needless_borrow.rs:265:22 + --> tests/ui/needless_borrow.rs:262:22 | LL | let _ = &mut (&mut { x.u }).x; | ^^^^^^^^^^^^^^ help: change this to: `{ x.u }` error: this expression creates a reference which is immediately dereferenced by the compiler - --> tests/ui/needless_borrow.rs:287:23 + --> tests/ui/needless_borrow.rs:284:23 | LL | option.unwrap_or((&x.0,)); | ^^^^ help: change this to: `x.0` +error: this expression creates a reference which is immediately dereferenced by the compiler + --> tests/ui/needless_borrow.rs:291:13 + | +LL | let _ = (&slice).len(); + | ^^^^^^^^ help: change this to: `slice` + error: aborting due to 28 previous errors