src/test/run-pass/panic-uninitialized-zeroed.rs

   1 // Copyright 2018 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 // ignore-wasm32-bare always compiled as panic=abort right now and this requires unwinding
  12 // This test checks that instantiating an uninhabited type via `mem::{uninitialized,zeroed}` results
  13 // in a runtime panic.
  14
  15 #![feature(never_type)]
  16
  17 use std::{mem, panic};
  18
  19 #[allow(dead_code)]
  20 struct Foo {
  21     x: u8,
  22     y: !,
  23 }
  24
  25 enum Bar {}
  26
  27 fn main() {
  28     unsafe {
  29         assert_eq!(
  30             panic::catch_unwind(|| {
  31                 mem::uninitialized::<!>()
  32             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  33                 s == "Attempted to instantiate uninhabited type ! using mem::uninitialized"
  34             })),
  35             Some(true)
  36         );
  37
  38         assert_eq!(
  39             panic::catch_unwind(|| {
  40                 mem::zeroed::<!>()
  41             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  42                 s == "Attempted to instantiate uninhabited type ! using mem::zeroed"
  43             })),
  44             Some(true)
  45         );
  46
  47         assert_eq!(
  48             panic::catch_unwind(|| {
  49                 mem::uninitialized::<Foo>()
  50             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  51                 s == "Attempted to instantiate uninhabited type Foo using mem::uninitialized"
  52             })),
  53             Some(true)
  54         );
  55
  56         assert_eq!(
  57             panic::catch_unwind(|| {
  58                 mem::zeroed::<Foo>()
  59             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  60                 s == "Attempted to instantiate uninhabited type Foo using mem::zeroed"
  61             })),
  62             Some(true)
  63         );
  64
  65         assert_eq!(
  66             panic::catch_unwind(|| {
  67                 mem::uninitialized::<Bar>()
  68             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  69                 s == "Attempted to instantiate uninhabited type Bar using mem::uninitialized"
  70             })),
  71             Some(true)
  72         );
  73
  74         assert_eq!(
  75             panic::catch_unwind(|| {
  76                 mem::zeroed::<Bar>()
  77             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  78                 s == "Attempted to instantiate uninhabited type Bar using mem::zeroed"
  79             })),
  80             Some(true)
  81         );
  82     }
  83 }