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416331ca XL |
1 | // This test checks that calling `mem::{uninitialized,zeroed}` with certain types results |
2 | // in a lint. | |
3 | ||
e1599b0c | 4 | #![feature(never_type, rustc_attrs)] |
416331ca XL |
5 | #![allow(deprecated)] |
6 | #![deny(invalid_value)] | |
7 | ||
8 | use std::mem::{self, MaybeUninit}; | |
e1599b0c XL |
9 | use std::ptr::NonNull; |
10 | use std::num::NonZeroU32; | |
416331ca XL |
11 | |
12 | enum Void {} | |
13 | ||
14 | struct Ref(&'static i32); | |
15 | struct RefPair((&'static i32, i32)); | |
16 | ||
17 | struct Wrap<T> { wrapped: T } | |
18 | enum WrapEnum<T> { Wrapped(T) } | |
19 | ||
e1599b0c XL |
20 | #[rustc_layout_scalar_valid_range_start(0)] |
21 | #[rustc_layout_scalar_valid_range_end(128)] | |
22 | #[repr(transparent)] | |
23 | pub(crate) struct NonBig(u64); | |
24 | ||
3dfed10e XL |
25 | /// A two-variant enum, thus needs a tag and may not remain uninitialized. |
26 | enum Fruit { | |
27 | Apple, | |
28 | Banana, | |
29 | } | |
30 | ||
31 | /// Looks like two variants but really only has one. | |
32 | enum OneFruit { | |
33 | Apple(!), | |
34 | Banana, | |
35 | } | |
36 | ||
2b03887a FG |
37 | enum OneFruitNonZero { |
38 | Apple(!), | |
39 | Banana(NonZeroU32), | |
40 | } | |
41 | ||
42 | enum TwoUninhabited { | |
43 | A(!), | |
44 | B(Void), | |
45 | } | |
46 | ||
47 | #[rustc_layout_scalar_valid_range_start(254)] | |
48 | #[rustc_layout_scalar_valid_range_end(1)] | |
49 | pub(crate) struct WrapAroundRange(u8); | |
50 | ||
416331ca XL |
51 | #[allow(unused)] |
52 | fn generic<T: 'static>() { | |
53 | unsafe { | |
54 | let _val: &'static T = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
55 | let _val: &'static T = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
56 | ||
57 | let _val: Wrap<&'static T> = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
58 | let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
59 | } | |
60 | } | |
61 | ||
62 | fn main() { | |
63 | unsafe { | |
e1599b0c | 64 | // Things that cannot even be zero. |
416331ca XL |
65 | let _val: ! = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
66 | let _val: ! = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
67 | ||
68 | let _val: (i32, !) = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
69 | let _val: (i32, !) = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
70 | ||
71 | let _val: Void = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
72 | let _val: Void = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
73 | ||
74 | let _val: &'static i32 = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
75 | let _val: &'static i32 = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
76 | ||
77 | let _val: Ref = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
78 | let _val: Ref = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
79 | ||
80 | let _val: fn() = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
81 | let _val: fn() = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
82 | ||
83 | let _val: Wrap<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
84 | let _val: Wrap<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
85 | ||
86 | let _val: WrapEnum<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
87 | let _val: WrapEnum<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
88 | ||
89 | let _val: Wrap<(RefPair, i32)> = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
90 | let _val: Wrap<(RefPair, i32)> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
91 | ||
e1599b0c XL |
92 | let _val: NonNull<i32> = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
93 | let _val: NonNull<i32> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
94 | ||
2b03887a FG |
95 | let _val: (NonZeroU32, i32) = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
96 | let _val: (NonZeroU32, i32) = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
97 | ||
60c5eb7d XL |
98 | let _val: *const dyn Send = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
99 | let _val: *const dyn Send = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
100 | ||
5e7ed085 FG |
101 | let _val: [fn(); 2] = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
102 | let _val: [fn(); 2] = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
103 | ||
2b03887a FG |
104 | let _val: TwoUninhabited = mem::zeroed(); //~ ERROR: does not permit zero-initialization |
105 | let _val: TwoUninhabited = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
106 | ||
107 | let _val: OneFruitNonZero = mem::zeroed(); //~ ERROR: does not permit zero-initialization | |
108 | let _val: OneFruitNonZero = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
109 | ||
e1599b0c XL |
110 | // Things that can be zero, but not uninit. |
111 | let _val: bool = mem::zeroed(); | |
112 | let _val: bool = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
113 | ||
114 | let _val: Wrap<char> = mem::zeroed(); | |
115 | let _val: Wrap<char> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
116 | ||
117 | let _val: NonBig = mem::zeroed(); | |
118 | let _val: NonBig = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
119 | ||
3dfed10e XL |
120 | let _val: Fruit = mem::zeroed(); |
121 | let _val: Fruit = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
122 | ||
5e7ed085 FG |
123 | let _val: [bool; 2] = mem::zeroed(); |
124 | let _val: [bool; 2] = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
125 | ||
f2b60f7d FG |
126 | let _val: i32 = mem::zeroed(); |
127 | let _val: i32 = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
128 | ||
129 | let _val: f32 = mem::zeroed(); | |
130 | let _val: f32 = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
131 | ||
132 | let _val: *const () = mem::zeroed(); | |
133 | let _val: *const () = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
134 | ||
135 | let _val: *const [()] = mem::zeroed(); | |
136 | let _val: *const [()] = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
137 | ||
2b03887a FG |
138 | let _val: WrapAroundRange = mem::zeroed(); |
139 | let _val: WrapAroundRange = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
140 | ||
141 | // Things where 0 is okay due to rustc implementation details, | |
142 | // but that are not guaranteed to keep working. | |
143 | let _val: Result<i32, i32> = mem::zeroed(); | |
144 | let _val: Result<i32, i32> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized | |
145 | ||
146 | // Some things that happen to be UB-free due to rustc implementation details, | |
147 | // but are not guaranteed to keep working. | |
148 | let _val: OneFruit = mem::zeroed(); | |
149 | let _val: OneFruit = mem::uninitialized(); | |
150 | ||
e1599b0c XL |
151 | // Transmute-from-0 |
152 | let _val: &'static i32 = mem::transmute(0usize); //~ ERROR: does not permit zero-initialization | |
153 | let _val: &'static [i32] = mem::transmute((0usize, 0usize)); //~ ERROR: does not permit zero-initialization | |
154 | let _val: NonZeroU32 = mem::transmute(0); //~ ERROR: does not permit zero-initialization | |
155 | ||
60c5eb7d XL |
156 | // `MaybeUninit` cases |
157 | let _val: NonNull<i32> = MaybeUninit::zeroed().assume_init(); //~ ERROR: does not permit zero-initialization | |
158 | let _val: NonNull<i32> = MaybeUninit::uninit().assume_init(); //~ ERROR: does not permit being left uninitialized | |
159 | let _val: bool = MaybeUninit::uninit().assume_init(); //~ ERROR: does not permit being left uninitialized | |
160 | ||
e1599b0c | 161 | // Some more types that should work just fine. |
416331ca XL |
162 | let _val: Option<&'static i32> = mem::zeroed(); |
163 | let _val: Option<fn()> = mem::zeroed(); | |
164 | let _val: MaybeUninit<&'static i32> = mem::zeroed(); | |
60c5eb7d | 165 | let _val: bool = MaybeUninit::zeroed().assume_init(); |
5e7ed085 FG |
166 | let _val: [bool; 0] = MaybeUninit::uninit().assume_init(); |
167 | let _val: [!; 0] = MaybeUninit::zeroed().assume_init(); | |
416331ca XL |
168 | } |
169 | } |