1 files changed, 21 insertions, 4 deletions
diff --git a/tests/ui/recursion/recursion-tail-cps.rs b/tests/ui/recursion/recursion-tail-cps.rs
index fe99dadf795..9014be0ce98 100644
--- a/tests/ui/recursion/recursion-tail-cps.rs
+++ b/tests/ui/recursion/recursion-tail-cps.rs
@@ -1,17 +1,34 @@
+//! Verify that mutually recursive functions use CPS to avoid overflowing the stack.
+
 //@ run-pass
 
-fn checktrue(rs: bool) -> bool { assert!(rs); return true; }
+fn checktrue(rs: bool) -> bool {
+    assert!(rs);
+    return true;
+}
 
-pub fn main() { let k = checktrue; evenk(42, k); oddk(45, k); }
+pub fn main() {
+    let k = checktrue;
+    evenk(42, k);
+    oddk(45, k);
+}
 
 fn evenk(n: isize, k: fn(bool) -> bool) -> bool {
     println!("evenk");
     println!("{}", n);
-    if n == 0 { return k(true); } else { return oddk(n - 1, k); }
+    if n == 0 {
+        return k(true);
+    } else {
+        return oddk(n - 1, k);
+    }
 }
 
 fn oddk(n: isize, k: fn(bool) -> bool) -> bool {
     println!("oddk");
     println!("{}", n);
-    if n == 0 { return k(false); } else { return evenk(n - 1, k); }
+    if n == 0 {
+        return k(false);
+    } else {
+        return evenk(n - 1, k);
+    }
 }