From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- .../pin-unsound-issue-66544-derefmut.rs | 33 ++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs (limited to 'src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs') diff --git a/src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs b/src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs new file mode 100644 index 000000000..606cc65a8 --- /dev/null +++ b/src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs @@ -0,0 +1,33 @@ +// Demonstrate that "rogue" `DerefMut` impls for `&T` are not allowed. +// +// https://github.com/rust-lang/rust/issues/66544 + +use std::cell::Cell; +use std::marker::PhantomPinned; +use std::ops::DerefMut; +use std::pin::Pin; + +struct MyType<'a>(Cell>>, PhantomPinned); + +impl<'a> DerefMut for &'a MyType<'a> { + //~^ ERROR E0751 + fn deref_mut(&mut self) -> &mut MyType<'a> { + self.0.take().unwrap() + } +} + +fn main() { + let mut unpinned = MyType(Cell::new(None), PhantomPinned); + let bad_addr = &unpinned as *const MyType<'_> as usize; + let p = Box::pin(MyType(Cell::new(Some(&mut unpinned)), PhantomPinned)); + + // p_ref is okay: it does not point to the bad_addr + let mut p_ref: Pin<&MyType<'_>> = p.as_ref(); + assert_ne!(bad_addr, &*p_ref as *const _ as usize); + + // but p_mut does point to bad_addr! this is unsound + let p_mut: Pin<&mut MyType<'_>> = p_ref.as_mut(); + assert_eq!(bad_addr, &*p_mut as *const _ as usize); + + println!("oh no!"); +} -- cgit v1.2.3