rust/src/test/compile-fail/lint-unconditional-recursion.rs

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![deny(unconditional_recursion)]
//~^ NOTE lint level defined here

#![allow(dead_code)]
fn foo() { //~ ERROR function cannot return without recurring
    foo(); //~ NOTE recursive call site
}

fn bar() {
    if true {
        bar()
    }
}

fn baz() { //~ ERROR function cannot return without recurring
    if true {
        baz() //~ NOTE recursive call site
    } else {
        baz() //~ NOTE recursive call site
    }
}

fn qux() {
    loop {}
}

fn quz() -> bool { //~ ERROR function cannot return without recurring
    if true {
        while quz() {} //~ NOTE recursive call site
        true
    } else {
        loop { quz(); } //~ NOTE recursive call site
    }
}

// Trait method calls.
trait Foo {
    fn bar(&self) { //~ ERROR function cannot return without recurring
        self.bar() //~ NOTE recursive call site
    }
}

impl Foo for Box<Foo+'static> {
    fn bar(&self) { //~ ERROR function cannot return without recurring
        loop {
            self.bar() //~ NOTE recursive call site
        }
    }
}

// Trait method call with integer fallback after method resolution.
impl Foo for i32 {
    fn bar(&self) { //~ ERROR function cannot return without recurring
        0.bar() //~ NOTE recursive call site
    }
}

impl Foo for u32 {
    fn bar(&self) {
        0.bar()
    }
}

// Trait method calls via paths.
trait Foo2 {
    fn bar(&self) { //~ ERROR function cannot return without recurring
        Foo2::bar(self) //~ NOTE recursive call site
    }
}

impl Foo2 for Box<Foo2+'static> {
    fn bar(&self) { //~ ERROR function cannot return without recurring
        loop {
            Foo2::bar(self) //~ NOTE recursive call site
        }
    }
}

struct Baz;
impl Baz {
    // Inherent method call.
    fn qux(&self) { //~ ERROR function cannot return without recurring
        self.qux(); //~ NOTE recursive call site
    }

    // Inherent method call via path.
    fn as_ref(&self) -> &Self { //~ ERROR function cannot return without recurring
        Baz::as_ref(self) //~ NOTE recursive call site
    }
}

// Trait method calls to impls via paths.
impl Default for Baz {
    fn default() -> Baz { //~ ERROR function cannot return without recurring
        let x = Default::default(); //~ NOTE recursive call site
        x
    }
}

// Overloaded operators.
impl std::ops::Deref for Baz {
    type Target = ();
    fn deref(&self) -> &() { //~ ERROR function cannot return without recurring
        &**self //~ NOTE recursive call site
    }
}

impl std::ops::Index<usize> for Baz {
    type Output = Baz;
    fn index(&self, x: usize) -> &Baz { //~ ERROR function cannot return without recurring
        &self[x] //~ NOTE recursive call site
    }
}

// Overloaded autoderef.
struct Quux;
impl std::ops::Deref for Quux {
    type Target = Baz;
    fn deref(&self) -> &Baz { //~ ERROR function cannot return without recurring
        self.as_ref() //~ NOTE recursive call site
    }
}

fn all_fine() {
    let _f = all_fine;
}

// issue 26333
trait Bar {
    fn method<T: Bar>(&self, x: &T) {
        x.method(x)
    }
}

fn main() {}