diff options
| -rw-r--r-- | clippy_lints/src/non_copy_const.rs | 15 | ||||
| -rw-r--r-- | tests/ui/borrow_interior_mutable_const.rs | 35 | ||||
| -rw-r--r-- | tests/ui/borrow_interior_mutable_const.stderr | 32 |
3 files changed, 64 insertions, 18 deletions
diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs index 031d69e86a1..f1df634701d 100644 --- a/clippy_lints/src/non_copy_const.rs +++ b/clippy_lints/src/non_copy_const.rs @@ -211,8 +211,21 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { needs_check_adjustment = false; }, ExprKind::Field(..) => { - dereferenced_expr = parent_expr; needs_check_adjustment = true; + + // Check whether implicit dereferences happened; + // if so, no need to go further up + // because of the same reason as the `ExprKind::Unary` case. + if cx + .typeck_results() + .expr_adjustments(dereferenced_expr) + .iter() + .any(|adj| matches!(adj.kind, Adjust::Deref(_))) + { + break; + } + + dereferenced_expr = parent_expr; }, ExprKind::Index(e, _) if ptr::eq(&**e, cur_expr) => { // `e[i]` => desugared to `*Index::index(&e, i)`, diff --git a/tests/ui/borrow_interior_mutable_const.rs b/tests/ui/borrow_interior_mutable_const.rs index fef9f4f39f8..a414832bcd3 100644 --- a/tests/ui/borrow_interior_mutable_const.rs +++ b/tests/ui/borrow_interior_mutable_const.rs @@ -2,7 +2,7 @@ #![allow(clippy::declare_interior_mutable_const, clippy::ref_in_deref)] use std::borrow::Cow; -use std::cell::Cell; +use std::cell::{Cell, UnsafeCell}; use std::fmt::Display; use std::sync::atomic::{AtomicUsize, Ordering}; use std::sync::Once; @@ -30,6 +30,37 @@ impl Trait<u32> for u64 { const ATOMIC: AtomicUsize = AtomicUsize::new(9); } +// This is just a pointer that can be safely dereferended, +// it's semantically the same as `&'static T`; +// but it isn't allowed to make a static reference from an arbitrary integer value at the moment. +// For more information, please see the issue #5918. +pub struct StaticRef<T> { + ptr: *const T, +} + +impl<T> StaticRef<T> { + /// Create a new `StaticRef` from a raw pointer + /// + /// ## Safety + /// + /// Callers must pass in a reference to statically allocated memory which + /// does not overlap with other values. + pub const unsafe fn new(ptr: *const T) -> StaticRef<T> { + StaticRef { ptr } + } +} + +impl<T> std::ops::Deref for StaticRef<T> { + type Target = T; + + fn deref(&self) -> &'static T { + unsafe { &*self.ptr } + } +} + +// use a tuple to make sure referencing a field behind a pointer isn't linted. +const CELL_REF: StaticRef<(UnsafeCell<u32>,)> = unsafe { StaticRef::new(std::ptr::null()) }; + fn main() { ATOMIC.store(1, Ordering::SeqCst); //~ ERROR interior mutability assert_eq!(ATOMIC.load(Ordering::SeqCst), 5); //~ ERROR interior mutability @@ -82,4 +113,6 @@ fn main() { assert_eq!(u64::ATOMIC.load(Ordering::SeqCst), 9); //~ ERROR interior mutability assert_eq!(NO_ANN.to_string(), "70"); // should never lint this. + + let _ = &CELL_REF.0; } diff --git a/tests/ui/borrow_interior_mutable_const.stderr b/tests/ui/borrow_interior_mutable_const.stderr index dc738064a17..1e0b3e4d20a 100644 --- a/tests/ui/borrow_interior_mutable_const.stderr +++ b/tests/ui/borrow_interior_mutable_const.stderr @@ -1,5 +1,5 @@ error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:34:5 + --> $DIR/borrow_interior_mutable_const.rs:65:5 | LL | ATOMIC.store(1, Ordering::SeqCst); //~ ERROR interior mutability | ^^^^^^ @@ -8,7 +8,7 @@ LL | ATOMIC.store(1, Ordering::SeqCst); //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:35:16 + --> $DIR/borrow_interior_mutable_const.rs:66:16 | LL | assert_eq!(ATOMIC.load(Ordering::SeqCst), 5); //~ ERROR interior mutability | ^^^^^^ @@ -16,7 +16,7 @@ LL | assert_eq!(ATOMIC.load(Ordering::SeqCst), 5); //~ ERROR interior mutabi = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:38:22 + --> $DIR/borrow_interior_mutable_const.rs:69:22 | LL | let _once_ref = &ONCE_INIT; //~ ERROR interior mutability | ^^^^^^^^^ @@ -24,7 +24,7 @@ LL | let _once_ref = &ONCE_INIT; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:39:25 + --> $DIR/borrow_interior_mutable_const.rs:70:25 | LL | let _once_ref_2 = &&ONCE_INIT; //~ ERROR interior mutability | ^^^^^^^^^ @@ -32,7 +32,7 @@ LL | let _once_ref_2 = &&ONCE_INIT; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:40:27 + --> $DIR/borrow_interior_mutable_const.rs:71:27 | LL | let _once_ref_4 = &&&&ONCE_INIT; //~ ERROR interior mutability | ^^^^^^^^^ @@ -40,7 +40,7 @@ LL | let _once_ref_4 = &&&&ONCE_INIT; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:41:26 + --> $DIR/borrow_interior_mutable_const.rs:72:26 | LL | let _once_mut = &mut ONCE_INIT; //~ ERROR interior mutability | ^^^^^^^^^ @@ -48,7 +48,7 @@ LL | let _once_mut = &mut ONCE_INIT; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:52:14 + --> $DIR/borrow_interior_mutable_const.rs:83:14 | LL | let _ = &ATOMIC_TUPLE; //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -56,7 +56,7 @@ LL | let _ = &ATOMIC_TUPLE; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:53:14 + --> $DIR/borrow_interior_mutable_const.rs:84:14 | LL | let _ = &ATOMIC_TUPLE.0; //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -64,7 +64,7 @@ LL | let _ = &ATOMIC_TUPLE.0; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:54:19 + --> $DIR/borrow_interior_mutable_const.rs:85:19 | LL | let _ = &(&&&&ATOMIC_TUPLE).0; //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -72,7 +72,7 @@ LL | let _ = &(&&&&ATOMIC_TUPLE).0; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:55:14 + --> $DIR/borrow_interior_mutable_const.rs:86:14 | LL | let _ = &ATOMIC_TUPLE.0[0]; //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -80,7 +80,7 @@ LL | let _ = &ATOMIC_TUPLE.0[0]; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:56:13 + --> $DIR/borrow_interior_mutable_const.rs:87:13 | LL | let _ = ATOMIC_TUPLE.0[0].load(Ordering::SeqCst); //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -88,7 +88,7 @@ LL | let _ = ATOMIC_TUPLE.0[0].load(Ordering::SeqCst); //~ ERROR interior mu = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:62:13 + --> $DIR/borrow_interior_mutable_const.rs:93:13 | LL | let _ = ATOMIC_TUPLE.0[0]; //~ ERROR interior mutability | ^^^^^^^^^^^^ @@ -96,7 +96,7 @@ LL | let _ = ATOMIC_TUPLE.0[0]; //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:67:5 + --> $DIR/borrow_interior_mutable_const.rs:98:5 | LL | CELL.set(2); //~ ERROR interior mutability | ^^^^ @@ -104,7 +104,7 @@ LL | CELL.set(2); //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:68:16 + --> $DIR/borrow_interior_mutable_const.rs:99:16 | LL | assert_eq!(CELL.get(), 6); //~ ERROR interior mutability | ^^^^ @@ -112,7 +112,7 @@ LL | assert_eq!(CELL.get(), 6); //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:81:5 + --> $DIR/borrow_interior_mutable_const.rs:112:5 | LL | u64::ATOMIC.store(5, Ordering::SeqCst); //~ ERROR interior mutability | ^^^^^^^^^^^ @@ -120,7 +120,7 @@ LL | u64::ATOMIC.store(5, Ordering::SeqCst); //~ ERROR interior mutability = help: assign this const to a local or static variable, and use the variable here error: a `const` item with interior mutability should not be borrowed - --> $DIR/borrow_interior_mutable_const.rs:82:16 + --> $DIR/borrow_interior_mutable_const.rs:113:16 | LL | assert_eq!(u64::ATOMIC.load(Ordering::SeqCst), 9); //~ ERROR interior mutability | ^^^^^^^^^^^ |