1 files changed, 194 insertions, 0 deletions
diff --git a/src/test/ui/lint/lint-unconditional-recursion.rs b/src/test/ui/lint/lint-unconditional-recursion.rs
new file mode 100644
index 000000000..ad052d36f
--- /dev/null
+++ b/src/test/ui/lint/lint-unconditional-recursion.rs
@@ -0,0 +1,194 @@
+#![deny(unconditional_recursion)]
+
+#![allow(dead_code)]
+fn foo() { //~ ERROR function cannot return without recursing
+    foo();
+}
+
+fn bar() {
+    if true {
+        bar()
+    }
+}
+
+fn baz() { //~ ERROR function cannot return without recursing
+    if true {
+        baz()
+    } else {
+        baz()
+    }
+}
+
+fn qux() {
+    loop {}
+}
+
+fn quz() -> bool { //~ ERROR function cannot return without recursing
+    if true {
+        while quz() {}
+        true
+    } else {
+        loop { quz(); }
+    }
+}
+
+// Trait method calls.
+trait Foo {
+    fn bar(&self) { //~ ERROR function cannot return without recursing
+        self.bar()
+    }
+}
+
+impl Foo for Box<dyn Foo + 'static> {
+    fn bar(&self) { //~ ERROR function cannot return without recursing
+        loop {
+            self.bar()
+        }
+    }
+}
+
+// Trait method call with integer fallback after method resolution.
+impl Foo for i32 {
+    fn bar(&self) { //~ ERROR function cannot return without recursing
+        0.bar()
+    }
+}
+
+impl Foo for u32 {
+    fn bar(&self) {
+        0.bar()
+    }
+}
+
+// Trait method calls via paths.
+trait Foo2 {
+    fn bar(&self) { //~ ERROR function cannot return without recursing
+        Foo2::bar(self)
+    }
+}
+
+impl Foo2 for Box<dyn Foo2 + 'static> {
+    fn bar(&self) { //~ ERROR function cannot return without recursing
+        loop {
+            Foo2::bar(self)
+        }
+    }
+}
+
+struct Baz;
+impl Baz {
+    // Inherent method call.
+    fn qux(&self) { //~ ERROR function cannot return without recursing
+        self.qux();
+    }
+
+    // Inherent method call via path.
+    fn as_ref(&self) -> &Self { //~ ERROR function cannot return without recursing
+        Baz::as_ref(self)
+    }
+}
+
+// Trait method calls to impls via paths.
+impl Default for Baz {
+    fn default() -> Baz { //~ ERROR function cannot return without recursing
+        let x = Default::default();
+        x
+    }
+}
+
+// Overloaded operators.
+impl std::ops::Deref for Baz {
+    type Target = ();
+    fn deref(&self) -> &() { //~ ERROR function cannot return without recursing
+        &**self
+    }
+}
+
+impl std::ops::Index<usize> for Baz {
+    type Output = Baz;
+    fn index(&self, x: usize) -> &Baz { //~ ERROR function cannot return without recursing
+        &self[x]
+    }
+}
+
+// Overloaded autoderef.
+struct Quux;
+impl std::ops::Deref for Quux {
+    type Target = Baz;
+    fn deref(&self) -> &Baz { //~ ERROR function cannot return without recursing
+        self.as_ref()
+    }
+}
+
+fn all_fine() {
+    let _f = all_fine;
+}
+
+// issue 26333
+trait Bar {
+    fn method<T: Bar>(&self, x: &T) {
+        x.method(x)
+    }
+}
+
+// Do not trigger on functions that may diverge instead of self-recursing (#54444)
+
+pub fn loops(x: bool) {
+    if x {
+        loops(x);
+    } else {
+        loop {}
+    }
+}
+
+pub fn panics(x: bool) {
+    if x {
+        panics(!x);
+    } else {
+        panic!("panics");
+    }
+}
+
+pub fn unreachable1() {
+    panic!();
+    unreachable1(); // WARN unreachable statement
+}
+
+pub fn unreachable2() {
+    loop {}
+    unreachable2(); // WARN unreachable statement
+}
+
+pub fn drop_and_replace(mut a: Option<String>) { //~ ERROR function cannot return without recursing
+    a = None;
+    drop_and_replace(a);
+}
+
+// Calls are assumed to return normally.
+pub fn call() -> String { //~ ERROR function cannot return without recursing
+    let s = String::new();
+    call();
+    s
+}
+
+// Arithmetic operations are assumed not to overflow.
+pub fn overflow_check(a: i32, b: i32) { //~ ERROR function cannot return without recursing
+    let _ = a + b;
+    overflow_check(a, b);
+}
+
+pub struct Point {
+    pub x: f32,
+    pub y: f32,
+}
+
+impl Default for Point {
+    fn default() -> Self { //~ ERROR function cannot return without recursing
+        Point {
+            x: Default::default(),
+            ..Default::default()
+        }
+    }
+}
+
+fn main() {}