Miri: detect wrong vtables in wide pointers

1 files changed, 12 insertions, 0 deletions

diff --git a/src/tools/miri/tests/fail/validity/wrong-dyn-trait-generic.rs b/src/tools/miri/tests/fail/validity/wrong-dyn-trait-generic.rs
new file mode 100644
index 00000000000..9b1cefc4b1d
--- /dev/null
+++ b/src/tools/miri/tests/fail/validity/wrong-dyn-trait-generic.rs
@@ -0,0 +1,12 @@
+use std::mem;
+
+// Make sure we notice the mismatch also if the difference is "only" in the generic
+// parameters of the trait.
+
+trait Trait<T> {}
+impl<T> Trait<T> for T {}
+
+fn main() {
+    let x: &dyn Trait<i32> = &0;
+    let _y: *const dyn Trait<u32> = unsafe { mem::transmute(x) }; //~ERROR: wrong trait
+}