diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index c4a7f717840..d7cb159149d 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -323,6 +323,8 @@ lint_invalid_reference_casting_assign_to_ref = assigning to `&T` is undefined be lint_invalid_reference_casting_borrow_as_mut = casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` .label = casting happend here +lint_invalid_reference_casting_note_book = for more information, visit + lint_lintpass_by_hand = implementing `LintPass` by hand .help = try using `declare_lint_pass!` or `impl_lint_pass!` instead diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 25982a45853..993c576d697 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -764,11 +764,13 @@ pub enum InvalidFromUtf8Diag { #[derive(LintDiagnostic)] pub enum InvalidReferenceCastingDiag { #[diag(lint_invalid_reference_casting_borrow_as_mut)] + #[note(lint_invalid_reference_casting_note_book)] BorrowAsMut { #[label] orig_cast: Option, }, #[diag(lint_invalid_reference_casting_assign_to_ref)] + #[note(lint_invalid_reference_casting_note_book)] AssignToRef { #[label] orig_cast: Option, diff --git a/tests/ui/const-generics/issues/issue-100313.stderr b/tests/ui/const-generics/issues/issue-100313.stderr index 42ad4d61c8e..796966b22d5 100644 --- a/tests/ui/const-generics/issues/issue-100313.stderr +++ b/tests/ui/const-generics/issues/issue-100313.stderr @@ -4,6 +4,7 @@ error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` LL | *(B as *const bool as *mut bool) = false; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | + = note: for more information, visit = note: `#[deny(invalid_reference_casting)]` on by default error[E0080]: evaluation of constant value failed diff --git a/tests/ui/lint/reference_casting.stderr b/tests/ui/lint/reference_casting.stderr index c1589f13835..47b95460ec3 100644 --- a/tests/ui/lint/reference_casting.stderr +++ b/tests/ui/lint/reference_casting.stderr @@ -4,6 +4,7 @@ error: casting `&T` to `&mut T` is undefined behavior, even if the reference is LL | let _num = &mut *(num as *const i32 as *mut i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | + = note: for more information, visit = note: `#[deny(invalid_reference_casting)]` on by default error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` @@ -11,54 +12,72 @@ error: casting `&T` to `&mut T` is undefined behavior, even if the reference is | LL | let _num = &mut *(num as *const i32).cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:23:16 | LL | let _num = &mut *std::ptr::from_ref(num).cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:25:16 | LL | let _num = &mut *std::ptr::from_ref({ num }).cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:27:16 | LL | let _num = &mut *{ std::ptr::from_ref(num) }.cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:29:16 | LL | let _num = &mut *(std::ptr::from_ref({ num }) as *mut i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:31:16 | LL | let _num = &mut *(num as *const i32).cast::().cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:33:16 | LL | let _num = &mut *(num as *const i32).cast::().cast_mut().cast_const().cast_mut(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:35:16 | LL | let _num = &mut *(std::ptr::from_ref(static_u8()) as *mut i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:37:16 | LL | let _num = &mut *std::mem::transmute::<_, *mut i32>(num); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:41:16 @@ -67,6 +86,8 @@ LL | let deferred = num as *const i32 as *mut i32; | ----------------------------- casting happend here LL | let _num = &mut *deferred; | ^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:44:16 @@ -75,60 +96,80 @@ LL | let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).ca | ---------------------------------------------------------------------------- casting happend here LL | let _num = &mut *deferred; | ^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:46:16 | LL | let _num = &mut *(num as *const _ as usize as *mut i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` --> $DIR/reference_casting.rs:50:9 | LL | &mut *((this as *const _) as *mut _) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:60:5 | LL | *(a as *const _ as *mut _) = String::from("Replaced"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:62:5 | LL | *(a as *const _ as *mut String) += " world"; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:64:5 | LL | *std::ptr::from_ref(num).cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:66:5 | LL | *std::ptr::from_ref({ num }).cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:68:5 | LL | *{ std::ptr::from_ref(num) }.cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:70:5 | LL | *(std::ptr::from_ref({ num }) as *mut i32) += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:72:5 | LL | *std::mem::transmute::<_, *mut i32>(num) += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:74:5 @@ -139,6 +180,8 @@ LL | | std::mem::transmute::<*const i32, *mut i32>(num), LL | | -1i32, LL | | ); | |_____^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:81:5 @@ -147,18 +190,24 @@ LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here LL | *value = 1; | ^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:83:5 | LL | *(num as *const i32).cast::().cast_mut() = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:85:5 | LL | *(num as *const _ as usize as *mut i32) = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:87:5 @@ -168,6 +217,8 @@ LL | let value = num as *const i32 as *mut i32; ... LL | std::ptr::write(value, 2); | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:89:5 @@ -177,6 +228,8 @@ LL | let value = num as *const i32 as *mut i32; ... LL | std::ptr::write_unaligned(value, 2); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:91:5 @@ -186,12 +239,16 @@ LL | let value = num as *const i32 as *mut i32; ... LL | std::ptr::write_volatile(value, 2); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` --> $DIR/reference_casting.rs:95:9 | LL | *(this as *const _ as *mut _) = a; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit error: aborting due to 29 previous errors