rust/tests/ui/unsafe-fields/unsafe-fields.rs
Jack Wrenn 91034adf30 Do not require that unsafe fields lack drop glue
Instead, we adopt the position that introducing an `unsafe` field
itself carries a safety invariant: that if you assign an invariant
to that field weaker than what the field's destructor requires,
you must ensure that field is in a droppable state in your
destructor.

See:
- https://github.com/rust-lang/rfcs/pull/3458#discussion_r1971676100
- https://rust-lang.zulipchat.com/#narrow/channel/213817-t-lang/topic/unsafe.20fields.20RFC/near/502113897
2025-02-28 16:32:06 +00:00

110 lines
2.2 KiB
Rust

//@ compile-flags: --crate-type=lib
#![allow(incomplete_features)]
#![feature(unsafe_fields)]
struct WithUnsafeField {
unsafe unsafe_field: u32,
safe_field: u32,
}
enum A {
WithUnsafeField { unsafe unsafe_field: u32, safe_field: u32 },
}
fn f(a: A) {
let A::WithUnsafeField { unsafe_field, safe_field } = a;
//~^ ERROR
}
struct WithInvalidUnsafeField {
unsafe unsafe_noncopy_field: Vec<u32>,
}
struct WithManuallyDropUnsafeField {
unsafe unsafe_noncopy_field: std::mem::ManuallyDrop<Vec<u32>>,
}
union WithUnsafeFieldUnion {
unsafe unsafe_field: u32,
safe_field: u32,
}
impl WithUnsafeField {
fn new() -> WithUnsafeField {
unsafe {
WithUnsafeField {
unsafe_field: 0,
safe_field: 0,
}
}
}
fn new_without_unsafe() -> WithUnsafeField {
WithUnsafeField { //~ ERROR
unsafe_field: 0,
safe_field: 0,
}
}
fn operate_on_safe_field(&mut self) {
self.safe_field = 2;
&self.safe_field;
self.safe_field;
}
fn set_unsafe_field(&mut self) {
unsafe {
self.unsafe_field = 2;
}
}
fn read_unsafe_field(&self) -> u32 {
unsafe {
self.unsafe_field
}
}
fn ref_unsafe_field(&self) -> &u32 {
unsafe {
&self.unsafe_field
}
}
fn destructure(&self) {
unsafe {
let Self { safe_field, unsafe_field } = self;
}
}
fn set_unsafe_field_without_unsafe(&mut self) {
self.unsafe_field = 2;
//~^ ERROR
}
fn read_unsafe_field_without_unsafe(&self) -> u32 {
self.unsafe_field
//~^ ERROR
}
fn ref_unsafe_field_without_unsafe(&self) -> &u32 {
&self.unsafe_field
//~^ ERROR
}
fn destructure_without_unsafe(&self) {
let Self { safe_field, unsafe_field } = self;
//~^ ERROR
let WithUnsafeField { safe_field, .. } = self;
}
fn offset_of(&self) -> usize {
std::mem::offset_of!(WithUnsafeField, unsafe_field)
}
fn raw_const(&self) -> *const u32 {
&raw const self.unsafe_field
//~^ ERROR
}
}