reviews

Author: BoxyUwU

tests/ui/cast/ptr-to-ptr-indirect-different-regions.rs

@@ -1,3 +1,6 @@
+// We want to forbid extending lifetimes on object types behind ptrs
+// as it may allow for uncallable VTable methods to become accessible.
+
 trait Trait {
     fn foo(&self) {}
 }

tests/ui/cast/ptr-to-ptr-indirect-different-regions.stderr

@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/ptr-to-ptr-indirect-different-regions.rs:8:5
+  --> $DIR/ptr-to-ptr-indirect-different-regions.rs:11:5
    |
 LL | fn bar<'a>(a: *mut MyWrap<(dyn Trait + 'a)>) -> *mut MyWrap<(dyn Trait + 'static)> {
    |        -- lifetime `'a` defined here
@@ -10,7 +10,7 @@ LL |     a as _
    = note: mutable pointers are invariant over their type parameter
    = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
 note: raw pointer casts of trait objects cannot extend lifetimes
-  --> $DIR/ptr-to-ptr-indirect-different-regions.rs:8:5
+  --> $DIR/ptr-to-ptr-indirect-different-regions.rs:11:5
    |
 LL |     a as _
    |     ^^^^^^