detect infinite recursion with tail calls in ctfe

2 files changed, 27 insertions, 0 deletions

diff --git a/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs
new file mode 100644
index 00000000000..0c55f13c16c
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs
@@ -0,0 +1,10 @@
+#![feature(explicit_tail_calls)]
+#![expect(incomplete_features)]
+
+const _: () = f();
+
+const fn f() {
+    become f(); //~ error: constant evaluation is taking a long time
+}
+
+fn main() {}
diff --git a/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr
new file mode 100644
index 00000000000..b5a96114a58
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr
@@ -0,0 +1,17 @@
+error: constant evaluation is taking a long time
+  --> $DIR/infinite-recursion-in-ctfe.rs:7:5
+   |
+LL |     become f();
+   |     ^^^^^^^^^^
+   |
+   = note: this lint makes sure the compiler doesn't get stuck due to infinite loops in const eval.
+           If your compilation actually takes a long time, you can safely allow the lint.
+help: the constant being evaluated
+  --> $DIR/infinite-recursion-in-ctfe.rs:4:1
+   |
+LL | const _: () = f();
+   | ^^^^^^^^^^^
+   = note: `#[deny(long_running_const_eval)]` on by default
+
+error: aborting due to 1 previous error
+