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

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![deny(unconditional_recursion)]
  12 #![allow(dead_code)]
  13 fn foo() { //~ ERROR function cannot return without recurring
  14     foo(); //~ NOTE recursive call site
  15 }
  16
  17 fn bar() {
  18     if true {
  19         bar()
  20     }
  21 }
  22
  23 fn baz() { //~ ERROR function cannot return without recurring
  24     if true {
  25         baz() //~ NOTE recursive call site
  26     } else {
  27         baz() //~ NOTE recursive call site
  28     }
  29 }
  30
  31 fn qux() {
  32     loop {}
  33 }
  34
  35 fn quz() -> bool { //~ ERROR function cannot return without recurring
  36     if true {
  37         while quz() {} //~ NOTE recursive call site
  38         true
  39     } else {
  40         loop { quz(); } //~ NOTE recursive call site
  41     }
  42 }
  43
  44 // Trait method calls.
  45 trait Foo {
  46     fn bar(&self) { //~ ERROR function cannot return without recurring
  47         self.bar() //~ NOTE recursive call site
  48     }
  49 }
  50
  51 impl Foo for Box<Foo+'static> {
  52     fn bar(&self) { //~ ERROR function cannot return without recurring
  53         loop {
  54             self.bar() //~ NOTE recursive call site
  55         }
  56     }
  57 }
  58
  59 // Trait method call with integer fallback after method resolution.
  60 impl Foo for i32 {
  61     fn bar(&self) { //~ ERROR function cannot return without recurring
  62         0.bar() //~ NOTE recursive call site
  63     }
  64 }
  65
  66 impl Foo for u32 {
  67     fn bar(&self) {
  68         0.bar()
  69     }
  70 }
  71
  72 // Trait method calls via paths.
  73 trait Foo2 {
  74     fn bar(&self) { //~ ERROR function cannot return without recurring
  75         Foo2::bar(self) //~ NOTE recursive call site
  76     }
  77 }
  78
  79 impl Foo2 for Box<Foo2+'static> {
  80     fn bar(&self) { //~ ERROR function cannot return without recurring
  81         loop {
  82             Foo2::bar(self) //~ NOTE recursive call site
  83         }
  84     }
  85 }
  86
  87 struct Baz;
  88 impl Baz {
  89     // Inherent method call.
  90     fn qux(&self) { //~ ERROR function cannot return without recurring
  91         self.qux(); //~ NOTE recursive call site
  92     }
  93
  94     // Inherent method call via path.
  95     fn as_ref(&self) -> &Self { //~ ERROR function cannot return without recurring
  96         Baz::as_ref(self) //~ NOTE recursive call site
  97     }
  98 }
  99
 100 // Trait method calls to impls via paths.
 101 impl Default for Baz {
 102     fn default() -> Baz { //~ ERROR function cannot return without recurring
 103         let x = Default::default(); //~ NOTE recursive call site
 104         x
 105     }
 106 }
 107
 108 // Overloaded operators.
 109 impl std::ops::Deref for Baz {
 110     type Target = ();
 111     fn deref(&self) -> &() { //~ ERROR function cannot return without recurring
 112         &**self //~ NOTE recursive call site
 113     }
 114 }
 115
 116 impl std::ops::Index<usize> for Baz {
 117     type Output = Baz;
 118     fn index(&self, x: usize) -> &Baz { //~ ERROR function cannot return without recurring
 119         &self[x] //~ NOTE recursive call site
 120     }
 121 }
 122
 123 // Overloaded autoderef.
 124 struct Quux;
 125 impl std::ops::Deref for Quux {
 126     type Target = Baz;
 127     fn deref(&self) -> &Baz { //~ ERROR function cannot return without recurring
 128         self.as_ref() //~ NOTE recursive call site
 129     }
 130 }
 131
 132 fn all_fine() {
 133     let _f = all_fine;
 134 }
 135
 136 // issue 26333
 137 trait Bar {
 138     fn method<T: Bar>(&self, x: &T) {
 139         x.method(x)
 140     }
 141 }
 142
 143 fn main() {}