add tests

Author: lcnr

tests/ui/closures/2229_closure_analysis/unique-borrows-are-invariant-1.rs

@@ -0,0 +1,18 @@
+// edition:2021
+
+// regression test for #112056
+
+fn extend_lifetime<'a, 'b>(x: &mut (&'a str,), y: &'b str) {
+    let mut closure = |input| x.0 = input;
+    //~^ ERROR: lifetime may not live long enough
+    closure(y);
+}
+
+fn main() {
+    let mut tuple = ("static",);
+    {
+        let x = String::from("temporary");
+        extend_lifetime(&mut tuple, &x);
+    }
+    println!("{}", tuple.0);
+}

tests/ui/closures/2229_closure_analysis/unique-borrows-are-invariant-1.stderr

@@ -0,0 +1,14 @@
+error: lifetime may not live long enough
+  --> $DIR/unique-borrows-are-invariant-1.rs:6:31
+   |
+LL | fn extend_lifetime<'a, 'b>(x: &mut (&'a str,), y: &'b str) {
+   |                    --  -- lifetime `'b` defined here
+   |                    |
+   |                    lifetime `'a` defined here
+LL |     let mut closure = |input| x.0 = input;
+   |                               ^^^^^^^^^^^ assignment requires that `'b` must outlive `'a`
+   |
+   = help: consider adding the following bound: `'b: 'a`
+
+error: aborting due to previous error
+

tests/ui/closures/2229_closure_analysis/unique-borrows-are-invariant-2.rs

@@ -0,0 +1,31 @@
+// edition:2021
+
+// regression test for #112056
+
+struct Spooky<'b> {
+    owned: Option<&'static u32>,
+    borrowed: &'b &'static u32,
+}
+
+impl<'b> Spooky<'b> {
+    fn create_self_reference<'a>(&'a mut self) {
+        let mut closure = || {
+            if let Some(owned) = &self.owned {
+                let borrow: &'a &'static u32 = owned;
+                self.borrowed = borrow;
+                //~^ ERROR: lifetime may not live long enough
+            }
+        };
+        closure();
+    }
+}
+
+fn main() {
+    let mut spooky: Spooky<'static> = Spooky {
+        owned: Some(&1),
+        borrowed: &&1,
+    };
+    spooky.create_self_reference();
+    spooky.owned = None;
+    println!("{}", **spooky.borrowed);
+}

tests/ui/closures/2229_closure_analysis/unique-borrows-are-invariant-2.stderr

@@ -0,0 +1,15 @@
+error: lifetime may not live long enough
+  --> $DIR/unique-borrows-are-invariant-2.rs:15:17
+   |
+LL | impl<'b> Spooky<'b> {
+   |      -- lifetime `'b` defined here
+LL |     fn create_self_reference<'a>(&'a mut self) {
+   |                              -- lifetime `'a` defined here
+...
+LL |                 self.borrowed = borrow;
+   |                 ^^^^^^^^^^^^^^^^^^^^^^ assignment requires that `'a` must outlive `'b`
+   |
+   = help: consider adding the following bound: `'a: 'b`
+
+error: aborting due to previous error
+