Skip to content

Commit

Permalink
Unrolled build for rust-lang#126004
Browse files Browse the repository at this point in the history
Rollup merge of rust-lang#126004 - compiler-errors:captures-soundness-test, r=lcnr

Add another test for hidden types capturing lifetimes that outlive but arent mentioned in substs

Another test to make sure future implementations of rust-lang#116040 don't have any subtle unsoundness 🤔

r? types
  • Loading branch information
rust-timer authored Jun 5, 2024
2 parents 5ee2dfd + dd6bca5 commit c7e00ae
Show file tree
Hide file tree
Showing 2 changed files with 53 additions and 0 deletions.
Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
// This test should never pass!

#![feature(type_alias_impl_trait)]

pub trait Captures<'a> {}
impl<T> Captures<'_> for T {}

pub struct MyTy<'a, 'b>(Option<*mut &'a &'b ()>);
unsafe impl Send for MyTy<'_, 'static> {}

pub mod step1 {
use super::*;
pub type Step1<'a, 'b: 'a> = impl Sized + Captures<'b> + 'a;
pub fn step1<'a, 'b: 'a>() -> Step1<'a, 'b> {
MyTy::<'a, 'b>(None)
}
}

pub mod step2 {
pub type Step2<'a> = impl Send + 'a;

// Although `Step2` is WF at the definition site, it's not WF in its
// declaration site (above). We check this in `check_opaque_meets_bounds`,
// which must remain sound.
pub fn step2<'a, 'b: 'a>() -> Step2<'a>
where crate::step1::Step1<'a, 'b>: Send
{
crate::step1::step1::<'a, 'b>()
//~^ ERROR hidden type for `Step2<'a>` captures lifetime that does not appear in bounds
}
}

fn step3<'a, 'b>() {
fn is_send<T: Send>() {}
is_send::<crate::step2::Step2::<'a>>();
}

fn main() {}
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
error[E0700]: hidden type for `Step2<'a>` captures lifetime that does not appear in bounds
--> $DIR/tait-hidden-erased-unsoundness-2.rs:28:9
|
LL | pub type Step2<'a> = impl Send + 'a;
| -------------- opaque type defined here
...
LL | pub fn step2<'a, 'b: 'a>() -> Step2<'a>
| -- hidden type `Step1<'a, 'b>` captures the lifetime `'b` as defined here
...
LL | crate::step1::step1::<'a, 'b>()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0700`.

0 comments on commit c7e00ae

Please sign in to comment.