From c54dcf59aed7f44260df41a800e7855436a205eb Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Tue, 13 Nov 2018 13:03:01 +0100
Subject: [PATCH] add some tests for retagging inside tuples and options

---
 .../stacked_borrows/return_invalid_mut_option.rs      | 11 +++++++++++
 .../stacked_borrows/return_invalid_mut_tuple.rs       | 11 +++++++++++
 .../stacked_borrows/return_invalid_shr_option.rs      | 11 +++++++++++
 .../stacked_borrows/return_invalid_shr_tuple.rs       | 11 +++++++++++
 4 files changed, 44 insertions(+)
 create mode 100644 tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_option.rs
 create mode 100644 tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_tuple.rs
 create mode 100644 tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_option.rs
 create mode 100644 tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_tuple.rs

diff --git a/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_option.rs b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_option.rs
new file mode 100644
index 000000000000..28a1f74c6ac2
--- /dev/null
+++ b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_option.rs
@@ -0,0 +1,11 @@
+// Make sure that we cannot return a `&mut` that got already invalidated, not even in an `Option`.
+fn foo(x: &mut (i32, i32)) -> Option<&mut i32> {
+    let xraw = x as *mut (i32, i32);
+    let ret = Some(unsafe { &mut (*xraw).1 });
+    let _val = unsafe { *xraw }; // invalidate xref
+    ret //~ ERROR does not exist on the stack
+}
+
+fn main() {
+    foo(&mut (1, 2));
+}
diff --git a/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_tuple.rs b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_tuple.rs
new file mode 100644
index 000000000000..3357af68a841
--- /dev/null
+++ b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_mut_tuple.rs
@@ -0,0 +1,11 @@
+// Make sure that we cannot return a `&mut` that got already invalidated, not even in a tuple.
+fn foo(x: &mut (i32, i32)) -> (&mut i32,) {
+    let xraw = x as *mut (i32, i32);
+    let ret = (unsafe { &mut (*xraw).1 },);
+    let _val = unsafe { *xraw }; // invalidate xref
+    ret //~ ERROR does not exist on the stack
+}
+
+fn main() {
+    foo(&mut (1, 2));
+}
diff --git a/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_option.rs b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_option.rs
new file mode 100644
index 000000000000..9d220991c330
--- /dev/null
+++ b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_option.rs
@@ -0,0 +1,11 @@
+// Make sure that we cannot return a `&` that got already invalidated, not even in an `Option`.
+fn foo(x: &mut (i32, i32)) -> Option<&i32> {
+    let xraw = x as *mut (i32, i32);
+    let ret = Some(unsafe { &(*xraw).1 });
+    unsafe { *xraw = (42, 23) }; // unfreeze
+    ret //~ ERROR is not frozen
+}
+
+fn main() {
+    foo(&mut (1, 2));
+}
diff --git a/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_tuple.rs b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_tuple.rs
new file mode 100644
index 000000000000..060fa25c2307
--- /dev/null
+++ b/tests/compile-fail-fullmir/stacked_borrows/return_invalid_shr_tuple.rs
@@ -0,0 +1,11 @@
+// Make sure that we cannot return a `&` that got already invalidated, not even in a tuple.
+fn foo(x: &mut (i32, i32)) -> (&i32,) {
+    let xraw = x as *mut (i32, i32);
+    let ret = (unsafe { &(*xraw).1 },);
+    unsafe { *xraw = (42, 23) }; // unfreeze
+    ret //~ ERROR is not frozen
+}
+
+fn main() {
+    foo(&mut (1, 2));
+}