CFI: Strip auto traits off Self for virtual calls

Additional trait bounds beyond the principal trait and its implications
are not possible in the vtable. This means that if a receiver is
`&dyn Foo + Send`, the function will only be expecting `&dyn Foo`.

This strips those auto traits off before CFI encoding.

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/ui/sanitizer/cfi-virtual-auto.rs b/tests/ui/sanitizer/cfi-virtual-auto.rs
new file mode 100644
index 00000000000..7a0c246a412
--- /dev/null
+++ b/tests/ui/sanitizer/cfi-virtual-auto.rs
@@ -0,0 +1,22 @@
+// Tests that calling a trait object method on a trait object with additional auto traits works.
+
+//@ needs-sanitizer-cfi
+// FIXME(#122848) Remove only-linux once OSX CFI binaries work
+//@ only-linux
+//@ compile-flags: --crate-type=bin -Cprefer-dynamic=off -Clto -Zsanitizer=cfi
+//@ compile-flags: -C target-feature=-crt-static -C codegen-units=1 -C opt-level=0
+//@ run-pass
+
+trait Foo {
+    fn foo(&self);
+}
+
+struct Bar;
+impl Foo for Bar {
+    fn foo(&self) {}
+}
+
+pub fn main() {
+    let x: &(dyn Foo + Send) = &Bar;
+    x.foo();
+}