Evaluating place expr that is never read from does not diverge

2 files changed, 33 insertions, 0 deletions

diff --git a/tests/ui/raw-ref-op/never-place-isnt-diverging.rs b/tests/ui/raw-ref-op/never-place-isnt-diverging.rs
new file mode 100644
index 00000000000..52f4158dbc9
--- /dev/null
+++ b/tests/ui/raw-ref-op/never-place-isnt-diverging.rs
@@ -0,0 +1,13 @@
+#![feature(never_type)]
+
+fn make_up_a_value<T>() -> T {
+    unsafe {
+    //~^ ERROR mismatched types
+        let x: *const ! = 0 as _;
+        &raw const *x;
+        // Since `*x` is `!`, HIR typeck used to think that it diverges
+        // and allowed the block to coerce to any value, leading to UB.
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/raw-ref-op/never-place-isnt-diverging.stderr b/tests/ui/raw-ref-op/never-place-isnt-diverging.stderr
new file mode 100644
index 00000000000..9eba57dde8f
--- /dev/null
+++ b/tests/ui/raw-ref-op/never-place-isnt-diverging.stderr
@@ -0,0 +1,20 @@
+error[E0308]: mismatched types
+  --> $DIR/never-place-isnt-diverging.rs:4:5
+   |
+LL |   fn make_up_a_value<T>() -> T {
+   |                      - expected this type parameter
+LL | /     unsafe {
+LL | |
+LL | |         let x: *const ! = 0 as _;
+LL | |         &raw const *x;
+LL | |         // Since `*x` is `!`, HIR typeck used to think that it diverges
+LL | |         // and allowed the block to coerce to any value, leading to UB.
+LL | |     }
+   | |_____^ expected type parameter `T`, found `()`
+   |
+   = note: expected type parameter `T`
+                   found unit type `()`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.