1 // ignore-tidy-linelength
2 // This test checks that calling `mem::{uninitialized,zeroed}` with certain types results
5 #![feature(never_type, rustc_attrs)]
7 #![deny(invalid_value)]
9 use std::mem::{self, MaybeUninit};
10 use std::ptr::NonNull;
11 use std::num::NonZeroU32;
15 struct Ref(&'static i32);
16 struct RefPair((&'static i32, i32));
18 struct Wrap<T> { wrapped: T }
19 enum WrapEnum<T> { Wrapped(T) }
21 #[rustc_layout_scalar_valid_range_start(0)]
22 #[rustc_layout_scalar_valid_range_end(128)]
24 pub(crate) struct NonBig(u64);
27 fn generic<T: 'static>() {
29 let _val: &'static T = mem::zeroed(); //~ ERROR: does not permit zero-initialization
30 let _val: &'static T = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
32 let _val: Wrap<&'static T> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
33 let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
39 // Things that cannot even be zero.
40 let _val: ! = mem::zeroed(); //~ ERROR: does not permit zero-initialization
41 let _val: ! = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
43 let _val: (i32, !) = mem::zeroed(); //~ ERROR: does not permit zero-initialization
44 let _val: (i32, !) = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
46 let _val: Void = mem::zeroed(); //~ ERROR: does not permit zero-initialization
47 let _val: Void = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
49 let _val: &'static i32 = mem::zeroed(); //~ ERROR: does not permit zero-initialization
50 let _val: &'static i32 = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
52 let _val: Ref = mem::zeroed(); //~ ERROR: does not permit zero-initialization
53 let _val: Ref = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
55 let _val: fn() = mem::zeroed(); //~ ERROR: does not permit zero-initialization
56 let _val: fn() = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
58 let _val: Wrap<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
59 let _val: Wrap<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
61 let _val: WrapEnum<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
62 let _val: WrapEnum<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
64 let _val: Wrap<(RefPair, i32)> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
65 let _val: Wrap<(RefPair, i32)> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
67 let _val: NonNull<i32> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
68 let _val: NonNull<i32> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
70 let _val: *const dyn Send = mem::zeroed(); //~ ERROR: does not permit zero-initialization
71 let _val: *const dyn Send = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
73 // Things that can be zero, but not uninit.
74 let _val: bool = mem::zeroed();
75 let _val: bool = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
77 let _val: Wrap<char> = mem::zeroed();
78 let _val: Wrap<char> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
80 let _val: NonBig = mem::zeroed();
81 let _val: NonBig = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
84 let _val: &'static i32 = mem::transmute(0usize); //~ ERROR: does not permit zero-initialization
85 let _val: &'static [i32] = mem::transmute((0usize, 0usize)); //~ ERROR: does not permit zero-initialization
86 let _val: NonZeroU32 = mem::transmute(0); //~ ERROR: does not permit zero-initialization
88 // `MaybeUninit` cases
89 let _val: NonNull<i32> = MaybeUninit::zeroed().assume_init(); //~ ERROR: does not permit zero-initialization
90 let _val: NonNull<i32> = MaybeUninit::uninit().assume_init(); //~ ERROR: does not permit being left uninitialized
91 let _val: bool = MaybeUninit::uninit().assume_init(); //~ ERROR: does not permit being left uninitialized
93 // Some more types that should work just fine.
94 let _val: Option<&'static i32> = mem::zeroed();
95 let _val: Option<fn()> = mem::zeroed();
96 let _val: MaybeUninit<&'static i32> = mem::zeroed();
97 let _val: i32 = mem::zeroed();
98 let _val: bool = MaybeUninit::zeroed().assume_init();