src/test/ui/panic-uninitialized-zeroed.rs

   1 // run-pass
   2 // ignore-wasm32-bare always compiled as panic=abort right now and this requires unwinding
   3 // This test checks that instantiating an uninhabited type via `mem::{uninitialized,zeroed}` results
   4 // in a runtime panic.
   5
   6 #![feature(never_type)]
   7 #![allow(deprecated, invalid_value)]
   8
   9 use std::{mem, panic};
  10
  11 #[allow(dead_code)]
  12 struct Foo {
  13     x: u8,
  14     y: !,
  15 }
  16
  17 enum Bar {}
  18
  19 fn main() {
  20     unsafe {
  21         assert_eq!(
  22             panic::catch_unwind(|| {
  23                 mem::uninitialized::<!>()
  24             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  25                 s == "Attempted to instantiate uninhabited type !"
  26             })),
  27             Some(true)
  28         );
  29
  30         assert_eq!(
  31             panic::catch_unwind(|| {
  32                 mem::zeroed::<!>()
  33             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  34                 s == "Attempted to instantiate uninhabited type !"
  35             })),
  36             Some(true)
  37         );
  38
  39         assert_eq!(
  40             panic::catch_unwind(|| {
  41                 mem::MaybeUninit::<!>::uninit().assume_init()
  42             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  43                 s == "Attempted to instantiate uninhabited type !"
  44             })),
  45             Some(true)
  46         );
  47
  48         assert_eq!(
  49             panic::catch_unwind(|| {
  50                 mem::uninitialized::<Foo>()
  51             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  52                 s == "Attempted to instantiate uninhabited type Foo"
  53             })),
  54             Some(true)
  55         );
  56
  57         assert_eq!(
  58             panic::catch_unwind(|| {
  59                 mem::zeroed::<Foo>()
  60             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  61                 s == "Attempted to instantiate uninhabited type Foo"
  62             })),
  63             Some(true)
  64         );
  65
  66         assert_eq!(
  67             panic::catch_unwind(|| {
  68                 mem::MaybeUninit::<Foo>::uninit().assume_init()
  69             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  70                 s == "Attempted to instantiate uninhabited type Foo"
  71             })),
  72             Some(true)
  73         );
  74
  75         assert_eq!(
  76             panic::catch_unwind(|| {
  77                 mem::uninitialized::<Bar>()
  78             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  79                 s == "Attempted to instantiate uninhabited type Bar"
  80             })),
  81             Some(true)
  82         );
  83
  84         assert_eq!(
  85             panic::catch_unwind(|| {
  86                 mem::zeroed::<Bar>()
  87             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  88                 s == "Attempted to instantiate uninhabited type Bar"
  89             })),
  90             Some(true)
  91         );
  92
  93         assert_eq!(
  94             panic::catch_unwind(|| {
  95                 mem::MaybeUninit::<Bar>::uninit().assume_init()
  96             }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
  97                 s == "Attempted to instantiate uninhabited type Bar"
  98             })),
  99             Some(true)
 100         );
 101     }
 102 }