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

   1 // ignore-wasm32-bare always compiled as panic=abort right now and this requires unwinding
   2 // This test checks that instantiating an uninhabited type via `mem::{uninitialized,zeroed}` results
   3 // in a runtime panic.
   4
   5 #![feature(never_type)]
   6
   7 use std::{mem, panic};
   8
   9 #[allow(dead_code)]
  10 struct Foo {
  11     x: u8,
  12     y: !,
  13 }
  14
  15 enum Bar {}
  16
  17 fn main() {
  18     unsafe {
  19         assert_eq!(
  20             panic::catch_unwind(|| {
  21                 mem::uninitialized::<!>()
  22             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  23                 s == "Attempted to instantiate uninhabited type !"
  24             })),
  25             Some(true)
  26         );
  27
  28         assert_eq!(
  29             panic::catch_unwind(|| {
  30                 mem::zeroed::<!>()
  31             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  32                 s == "Attempted to instantiate uninhabited type !"
  33             })),
  34             Some(true)
  35         );
  36
  37         assert_eq!(
  38             panic::catch_unwind(|| {
  39                 mem::MaybeUninit::<!>::uninit().assume_init()
  40             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  41                 s == "Attempted to instantiate uninhabited type !"
  42             })),
  43             Some(true)
  44         );
  45
  46         assert_eq!(
  47             panic::catch_unwind(|| {
  48                 mem::uninitialized::<Foo>()
  49             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  50                 s == "Attempted to instantiate uninhabited type Foo"
  51             })),
  52             Some(true)
  53         );
  54
  55         assert_eq!(
  56             panic::catch_unwind(|| {
  57                 mem::zeroed::<Foo>()
  58             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  59                 s == "Attempted to instantiate uninhabited type Foo"
  60             })),
  61             Some(true)
  62         );
  63
  64         assert_eq!(
  65             panic::catch_unwind(|| {
  66                 mem::MaybeUninit::<Foo>::uninit().assume_init()
  67             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  68                 s == "Attempted to instantiate uninhabited type Foo"
  69             })),
  70             Some(true)
  71         );
  72
  73         assert_eq!(
  74             panic::catch_unwind(|| {
  75                 mem::uninitialized::<Bar>()
  76             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  77                 s == "Attempted to instantiate uninhabited type Bar"
  78             })),
  79             Some(true)
  80         );
  81
  82         assert_eq!(
  83             panic::catch_unwind(|| {
  84                 mem::zeroed::<Bar>()
  85             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  86                 s == "Attempted to instantiate uninhabited type Bar"
  87             })),
  88             Some(true)
  89         );
  90
  91         assert_eq!(
  92             panic::catch_unwind(|| {
  93                 mem::MaybeUninit::<Bar>::uninit().assume_init()
  94             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  95                 s == "Attempted to instantiate uninhabited type Bar"
  96             })),
  97             Some(true)
  98         );
  99     }
 100 }